WorldWideScience

Sample records for currents temperature salinity

  1. Observed features of temperature, salinity and current in central Chukchi Sea during the summer of 2012

    Institute of Scientific and Technical Information of China (English)

    HE Yan; LIU Na; CHEN Hongxia; TENG Fei; LIN Lina; WANG Huiwu

    2015-01-01

    During the summer of 2012, the fifth CHINARE Arctic Expedition was carried out, and a submersible mooring system was deployed in M5 station located at (69°30.155'N,169°00.654'W) and recovered 50d later. A set of temperature, salinity and current profile records was acquired. The characteristics of these observations are analyzed in this paper. Some main results are achieved as below. (1) Temperature generally decreases while salinity generally increases with increasing depth. The average values of all records are 2.98℃ and 32.21 psu. (2) Salinity and temperature are well negatively correlated, and the correlation coefficient between them is –0.84. However, they did not always vary synchronously. Their co-variation featured different characters during different significant periods. (3) The average velocity for the whole water column is 141 mm/s with directional angle of 347.1°. The statistical distribution curve of velocity record number gets narrower with increasing depth. More than 85% of the recorded velocities are northward, and the mean magnitudes of dominated northward velocities are 100–150 mm/s. (4) Rotary spectrum analysis shows that motions with low frequency take a majority of energy in all layers. The most significant energy peaks for all layers are around 0.012 cph (about 3.5 d period), while the tidal motion in mooring area is nonsignificant. (5) Velocities in all layers feature similar and synchronous temporal variations, except for the slight decrease in magnitude and leftward twist from top to bottom. The directions of velocity correspond well to those of surface wind. The average northward volume transport per square meter is 0.1–0.2 m3/s under southerly wind, but about –0.2 m3/s during northerly wind burst.

  2. Neural Networks Application For Current, Salinity And Temperature Forecasting In Osaka Bay

    Science.gov (United States)

    Aguilar, Sandra G.; El Serafy, Ghada Y.

    2010-05-01

    Artificial neural networks (ANNs) have been wide used in hydraulic applications. The main advantage of this method lies in its ability to represent both linear and non-linear relationships that are present in the processes and thus in the measured data. The artificial neural network is a well established technique for representing and predicting the dynamic state of water systems and environmental systems. In comparison to more conventional model techniques and complicated softwares, the ANN is specifically an attractive technique for operational forecasting systems that are focusing on forecasting few state variables at few essential locations. In this paper, an application of ANN for Osaka bay in Japan is presented. The human activities in the bay have an influence in the deterioration of regional seawater quality giving an importance to assess the behavior of water quality variables at three essential monitoring points. Those points are located in the northwest part of the bay and considered in this paper to be the locations of interest for operational forecasting. Moreover, in the presence of spatial and temporal variability of the dynamic state, the selection of appropriate set of input variables during the ANN development is important and rather difficult. In this study, a correlation analysis was used to help in defining the most important input variables and lag time in the recursive ANN here presented. Different ANN structures are presented to show that spatial and temporal correlations patters found in the correlation analysis have an impact in the performance of the ANN when choosing inputs and outputs. The results show that ANNs have great potential to simulate salinity, temperature and velocity field at locations of interest. Finally, a comparison with a numerical model (Osaka Bay Forecasting System) is presented to show the efficiency and accuracy of the ANN. The results were also compared to a simple data assimilation scheme that is also available

  3. Temperature, salinity, dissolved oxygen, nutrients, and currents data from the Chesapeake Bay region from multiple platforms, July 1949 - July 1965 (NODC Accession 7000995)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are currently only available in analog form. A digital scan of the pages containing measured values for temperature, salinity, dissolved oxygen,...

  4. Temperature and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 02 June 1978 - 01 June 1979 (NODC Accession 8000499)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity data were collected using moored current meter casts in the Gulf of Mexico from June 2, 1978 to June 1, 1979. Data were submitted by...

  5. Temperature and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 01 September 1980 - 01 September 1980 (NODC Accession 8000608)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity data were collected using moored current meter casts in the Gulf of Mexico from September 1, 1980 to September 1, 1980. Data were submitted...

  6. Corrosion protection of Arctic offshore structures: Final report. [Effects of temperature and salinity on required cathodic protection current

    Energy Technology Data Exchange (ETDEWEB)

    Sackinger, W.M.; Rogers, J.C.; Feyk, C.; Theuveny, B.

    1985-10-01

    Results are presented for a research program on corrosion prevention for Arctic offshore structures which are in contact with sea ice for a significant portion of the year. The electrical method most adaptable for structure protection involves the injection of impressed current from several remote anodes buried just beneath the sea floor. The electrical resistivity of annual sea ice as a function of temperature and salinity is presented. Details of the interface layers formed between sea ice and steel in the presence of current injection are shown. A computer program was developed to enable the calculation of protective current density into the structure, in the presence of ice rubble and ridges around the structure. The program and the results of an example calculation are given for a caisson- retained island structure. 81 refs., 103 figs., 3 tabs.

  7. Current direction, wind direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 01 February 1981 - 01 February 1981 (NODC Accession 8100516)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, wind direction, and salinity data were collected using moored current meter casts in the Gulf of Mexico from February 1, 1981 to...

  8. Current direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Topographic Features project, 16 January 1979 - 01 May 1982 (NODC Accession 8400120)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and salinity data were collected using moored current meter casts in the Gulf of Mexico from January 16, 1979 to May 1, 1982. Data...

  9. Current direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 04 December 1983 - 01 December 1984 (NODC Accession 8500251)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and salinity data were collected using moored current meter casts in the Gulf of Mexico from December 4, 1983 to December 1, 1984....

  10. Current direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 18 September 1980 - 01 March 1981 (NODC Accession 8100555)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and salinity data were collected using moored current meter casts in the Gulf of Mexico from September 18, 1980 to March 1, 1981....

  11. Current direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 01 June 1983 - 01 September 1983 (NODC Accession 8400050)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and salinity data were collected using moored current meter casts in the Gulf of Mexico from June 1, 1983 to September 1, 1983. Data...

  12. Current direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 17 August 1979 - 01 May 1980 (NODC Accession 8100541)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and salinity data were collected using moored current meter casts in the Gulf of Mexico from August 17, 1979 to May 1, 1980. Data...

  13. Current direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 07 February 1981 - 01 June 1982 (NODC Accession 8300040)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and salinity data were collected using moored current meter casts in the Gulf of Mexico from February 7, 1981 to June 1, 1982. Data...

  14. Current direction, temperature, depth, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 01 July 1980 - 01 August 1980 (NODC Accession 8000498)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, depth, and salinity data were collected using moored current meter casts in the Gulf of Mexico from July 1, 1980 to August 1, 1980....

  15. Current direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 10 September 1979 - 31 March 1981 (NODC Accession 8100554)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and salinity data were collected using moored current meter casts in the Gulf of Mexico from September 10, 1979 to March 31, 1981....

  16. Current direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 18 October 1982 - 01 August 1983 (NODC Accession 8400010)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and salinity data were collected using moored current meter casts in the Gulf of Mexico from October 18, 1982 to August 1, 1983. Data...

  17. Current direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 11 May 1984 - 01 August 1984 (NODC Accession 8400216)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and salinity data were collected using moored current meter casts in the Gulf of Mexico from July 11, 1984 to August 1, 1984. Data...

  18. Current direction, temperature, salinity, and taxonomic code data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 18 August 1979 - 21 January 1981 (NODC Accession 8100502)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, current direction, and taxonomic data were collected using moored current meter casts in the Gulf of Mexico from August 18, 1979 to January...

  19. Current direction, temperature, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 31 August 1983 - 01 October 1984 (NODC Accession 8500021)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and salinity data were collected using moored current meter casts in the Gulf of Mexico from August 31, 1983 to October 1, 1984. Data...

  20. Temperature, salinity, and current direction data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 01 May 1978 - 01 June 1979 (NODC Accession 8000245)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and current direction data were collected using moored current meter casts in the Gulf of Mexico from June 1, 1978 to June 1, 1979. Data were...

  1. Time-series current measurements, temperature, and salinity data from CTD, moored buoy, and current meter casts from the Norton Sound Alaska from 14 July 1985 to 22 July 1985 (NODC Accession 0000368)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Time-series current measurements, temperature, and salinity data were collected from fixed platforms at the Bering Sea - Norton Sound from July 14, 1985 to July 22,...

  2. Oceanographic temperature, salinity, pressure, and current data collected in the Sub Tropical North Atlantic Ocean, SPURS-1 (NCEI Accession 0125198)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SPURS field campaign consisted of a variety of observing assets. SPURS-1 (Salinity Processes in the Upper Ocean Regional Study - North Atlantic Field Campaign)...

  3. Salinity, sigma-t, and temperature data from moored current meter and CTD casts in the North Atlantic Ocean from 29 August 1981 - 07 December 1981 (NODC Accession 8300048)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity, sigma-t, and temperature data were collected using moored current meter and CTD casts in the North Atlantic Ocean from August 29, 1981 to December 7, 1981....

  4. Temperature, wind direction, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 01 January 1981 - 01 January 1981 (NODC Accession 8100474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, wind direction, and salinity data were collected using moored current meter casts in the Gulf of Mexico from January 1, 1981 to January 1, 1981. Data...

  5. Temperature and salinity data from moored current meter and bottle casts in the Gulf of Mexico as part of the Brine Disposal project, 15 September 1977 - 19 December 1977 (NODC Accession 7800318)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity data were collected using moored current meter and bottle casts in the Gulf of Mexico from September 15, 1977 to January 19, 1977. Data were...

  6. Seawater temperature and salinity observed from the CORC1 and CORC2 moorings in the southern California Current (NE Pacific) from 2008-09-20 to 2012-11-14 (NCEI Accession 0137858)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity observations from instruments on the CORC1 and CORC2 moorings in the southern California Current, part of the CORC project (Consortium on...

  7. Temperature, wind direction, and salinity data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 01 December 1980 - 01 December 1980 (NODC Accession 8100457)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, wind direction, and salinity data were collected using moored current meter casts in the Gulf of Mexico from December 1, 1980 to December 1, 1980. Data...

  8. Coastal Circulation and Sediment Dynamics in Hanalei Bay, Kaua'i, Part IV, Measurements of Waves, Currents, Temperature, Salinity, and Turbidity, June-September 2006

    Science.gov (United States)

    Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.; Field, Michael E.

    2008-01-01

    High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Hanalei Bay, northern Kaua'i, Hawai'i, during the summer of 2006 to better understand coastal circulation, sediment dynamics, and the potential impact of a river flood in a coral reef-lined embayment during quiescent summer conditions. A series of bottommounted instrument packages were deployed in water depths of 10 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity, and turbidity. These data were supplemented with a series of profiles through the water column to characterize the vertical and spatial variability in water column properties within the bay. These measurements support the ongoing process studies being conducted as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Pacific Coral Reef Project; the ultimate goal is to better understand the transport mechanisms of sediment, larvae, pollutants, and other particles in coral reef settings. Information regarding the USGS study conducted in Hanalei Bay during the 2005 summer is available in Storlazzi and others (2006), Draut and others (2006) and Carr and others (2006). This report, the last part in a series, describes data acquisition, processing, and analysis for the 2006 summer data set.

  9. Coastal circulation and sediment dynamics in Maunalua Bay, Oahu, Hawaii, measurements of waves, currents, temperature, salinity, and turbidity; November 2008-February 2009

    Science.gov (United States)

    Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.; Field, Michael E.

    2010-01-01

    High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Maunalua Bay, southern Oahu, Hawaii, during the 2008-2009 winter to better understand coastal circulation, water-column properties, and sediment dynamics during a range of conditions (trade winds, kona storms, relaxation of trade winds, and south swells). A series of bottom-mounted instrument packages were deployed in water depths of 20 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity, and turbidity. These data were supplemented with a series of profiles through the water column to characterize the vertical and spatial variability in water-column properties within the bay. These measurements support the ongoing process studies being done as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Pacific Coral Reef Project; the ultimate goal of these studies is to better understand the transport mechanisms of sediment, larvae, pollutants, and other particles in coral reef settings. Project Objectives The objective of this study was to understand the temporal variations in currents, waves, tides, temperature, salinity and turbidity within a coral-lined embayment that receives periodic discharges of freshwater and sediment from multiple terrestrial sources in the Maunalua Bay. Instrument packages were deployed for a three-month period during the 2008-2009 winter and a series of vertical profiles were collected in November 2008, and again in February 2009, to characterize water-column properties within the bay. Measurements of flow and water-column properties in Maunalua Bay provided insight into the potential fate of terrestrial sediment, nutrient, or contaminant delivered to the marine environment and coral larval transport within the embayment. Such data are useful for providing baseline information for future watershed decisions and for establishing guidelines for

  10. Coastal circulation and sediment dynamics in Maunalua Bay, Oahu, Hawaii, measurements of waves, currents, temperature, salinity, and turbidity; November 2008-February 2009

    Science.gov (United States)

    Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.; Field, Michael E.

    2010-01-01

    High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Maunalua Bay, southern Oahu, Hawaii, during the 2008-2009 winter to better understand coastal circulation, water-column properties, and sediment dynamics during a range of conditions (trade winds, kona storms, relaxation of trade winds, and south swells). A series of bottom-mounted instrument packages were deployed in water depths of 20 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity, and turbidity. These data were supplemented with a series of profiles through the water column to characterize the vertical and spatial variability in water-column properties within the bay. These measurements support the ongoing process studies being done as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Pacific Coral Reef Project; the ultimate goal of these studies is to better understand the transport mechanisms of sediment, larvae, pollutants, and other particles in coral reef settings. Project Objectives The objective of this study was to understand the temporal variations in currents, waves, tides, temperature, salinity and turbidity within a coral-lined embayment that receives periodic discharges of freshwater and sediment from multiple terrestrial sources in the Maunalua Bay. Instrument packages were deployed for a three-month period during the 2008-2009 winter and a series of vertical profiles were collected in November 2008, and again in February 2009, to characterize water-column properties within the bay. Measurements of flow and water-column properties in Maunalua Bay provided insight into the potential fate of terrestrial sediment, nutrient, or contaminant delivered to the marine environment and coral larval transport within the embayment. Such data are useful for providing baseline information for future watershed decisions and for establishing guidelines for

  11. Coastal circulation and potential coral-larval dispersal in Maunalua Bay, O'ahu, Hawaii—Measurements of waves, currents, temperature, and salinity, June-September 2010

    Science.gov (United States)

    Presto, M. Katherine; Storlazzi, Curt D.; Logan, Joshua B.; Reiss, Thomas E.; Rosenberger, Kurt J.

    2012-01-01

    This report presents a summary of fieldwork conducted in Maunalua Bay, O'ahu, Hawaii to address coral-larval dispersal and recruitment from June through September, 2010. The objectives of this study were to understand the temporal and spatial variations in currents, waves, tides, temperature, and salinity in Maunalua Bay during the summer coral-spawning season of Montipora capitata. Short-term vessel surveys and satellite-tracked drifters were deployed to measure currents during the June 2010 spawning event and to supplement the longer-term measurements of currents and water-column properties by fixed, bottom-mounted instruments deployed in Maunalua Bay. These data show that currents at the surface and just below the surface where coral larvae are found are often oriented in opposite directions due primarily to tidal and trade-winds forcing as the primary mechanisms of circulation in the bay. These data extend our understanding of coral-larvae dispersal patterns due to tidal and wind-driven currents and may be applicable to larvae of other Hawaiian corals.

  12. Ocean current velocity, temperature and salinity collected during 2010 and 2011 in Vieques Sound and Virgin Passage (NODC Accession 0088063)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nortek 600kHz Aquadopp acoustic current profilers were deployed between March 2010 and April 2011 on shallow water moorings located in Vieques Sound, Puerto Rico,...

  13. Influence of temperature and salinity on hydrodynamic forces

    Directory of Open Access Journals (Sweden)

    A. Escobar

    2016-12-01

    Full Text Available The purpose of this study is to introduce an innovative approach to offshore engineering so as to take variations in sea temperature and salinity into account in the calculation of hydrodynamic forces. With this in mind, a thorough critical analysis of the influence of sea temperature and salinity on hydrodynamic forces on piles like those used nowadays in offshore wind farms will be carried out. This influence on hydrodynamic forces occurs through a change in water density and viscosity due to temperature and salinity variation. Therefore, the aim here is to observe whether models currently used to estimate wave forces on piles are valid for different ranges of sea temperature and salinity apart from observing the limit when diffraction or nonlinear effects arise combining both effects with the magnitude of the pile diameter. Hence, specific software has been developed to simulate equations in fluid mechanics taking into account nonlinear and diffraction effects. This software enables wave produced forces on a cylinder supported on the sea bed to be calculated. The study includes observations on the calculation model's sensitivity as to a variation in the cylinder's diameter, on the one hand and, on the other, as to temperature and salinity variation. This software will enable an iterative calculation to be made for finding out the shape the pressure wave caused when a wave passes over will have for different pile diameters and water with different temperature and salinity.

  14. Global Temperature and Salinity Profile Programme (GTSPP) Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Temperature-Salinity Profile Programme (GTSPP) develops and maintains a global ocean temperature and salinity resource with data that are both up-to-date...

  15. Refined Modeling of Water Temperature and Salinity in Coastal Areas

    Institute of Scientific and Technical Information of China (English)

    SHEN Yongming; ZHENG Yonghong; QIU Dahong

    2000-01-01

    The prediction of water temperature and salinity in coastal areas is one of the essential tasks in water quality control and management. This paper takes a refined forecasting model of water temperature and salinity in coastal areas as a basic target. Based on the Navier-Stokes equation and k- turbulence model, taking the characteristics of coastal areas into account, a refined model for water temperatureand salinity in coastal areas has been developed to simulate the seasonal variations of water temperatureand salinity fields in the Hakata Bay, Japan. The model takes into account the effects of a variety ofhydrodynamic and meteorological factors on water temperature and salinity. It predicts daily fluctuations in water temperature and salinity at different depths throughout the year. The model has been calibrated well against the data set of historical water temperature and salinity observations in the Hakata Bay,Japan.

  16. Salinity Temperature and Roughness Remote Scanner (STARRS)

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides spatially continuous high-resolution surface salinity imagery in a synoptic manner from small aircraft. Its output complements data collected from...

  17. Long term Milford Lab Temperature and Salinity Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity of sea water entering the Milford NOAA Laboratory has been being collected since 1948. From 1948-1974 the temperature data was collected at...

  18. Current, temperature, salinity, and other data from bottom instrument packages off Wrightsville Beach, North Carolina, from 02 April 1996 to 22 May 1996 (NODC Accession 0066099)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Measurements of bottom currents and waves to investigate the flow field and sediment transport in a rippled scour depression offshore of Wrightsville Beach, NC.

  19. Coastal circulation and sediment dynamics in Pelekane and Kawaihae Bays, Hawaii--measurements of waves, currents, temperature, salinity, turbidity, and geochronology: November 2010--March 2011

    Science.gov (United States)

    Storlazzi, Curt D.; Field, Michael E.; Presto, M. Katherine; Swarzenski, Peter W.; Logan, Joshua B.; Reiss, Thomas E.; Elfers, Timothy C.; Cochran, Susan A.; Torresan, Michael E.; Chezar, Hank

    2012-01-01

    Coral reef communities on the Island of Hawaii have been heavily affected by the construction of Kawaihae Harbor in the 1950s and by subsequent changes in land use in the adjacent watershed. Sedimentation and other forms of land-based pollution have led to declines in water quality and coral reef health over the past two decades (Tissot, 1998). Erosion mitigation efforts are underway on land, and there is a need to evaluate the impact of these actions on the adjacent coastal ecosystem. The Kohala Center and Kohala Watershed Partnership was awarded $2.69 million from the National Oceanographic and Atmospheric Administration’s (NOAA) Restoration Center as part of the American Recovery and Reinvestment Act of 2009 to stabilize soil and improve land-use practices in the Pelekane Bay watershed. The grant allowed the Kohala Watershed Partnership to implement various upland watershed management activities to reduce land-based sources of pollution into Pelekane Bay. However, a number of questions must be answered in order to: (1) evaluate the effectiveness of the terrestrial watershed remediation efforts; (2) understand the potential of the local marine ecosystem to recover; and (3) understand the potential threat that existing mud deposits in the bay pose to adjacent, relatively pristine coral reef ecosystems. The goal of this experiment was to help address these questions and establish a framework to evaluate the success of the Kohala Watershed Partnership restoration efforts. This research program will also provide resource managers with information relevant to other watershed restoration efforts currently being planned in neighboring watersheds. This project involved an interdisciplinary team of coral reef biologists from the University of Hawaii Coral Reef Assessment and Monitoring Program, who focused on the impact of sedimentation on the biota of Pelekane Bay, and a team of geologists and oceanographers from the U.S. Geological Survey (USGS), who focused on the

  20. Coastal circulation and sediment dynamics in Pelekane and Kawaihae Bays, Hawaii--measurements of waves, currents, temperature, salinity, turbidity, and geochronology: November 2010--March 2011

    Science.gov (United States)

    Storlazzi, Curt D.; Field, Michael E.; Presto, M. Katherine; Swarzenski, Peter W.; Logan, Joshua B.; Reiss, Thomas E.; Elfers, Timothy C.; Cochran, Susan A.; Torresan, Michael E.; Chezar, Hank

    2012-01-01

    Coral reef communities on the Island of Hawaii have been heavily affected by the construction of Kawaihae Harbor in the 1950s and by subsequent changes in land use in the adjacent watershed. Sedimentation and other forms of land-based pollution have led to declines in water quality and coral reef health over the past two decades (Tissot, 1998). Erosion mitigation efforts are underway on land, and there is a need to evaluate the impact of these actions on the adjacent coastal ecosystem. The Kohala Center and Kohala Watershed Partnership was awarded $2.69 million from the National Oceanographic and Atmospheric Administration’s (NOAA) Restoration Center as part of the American Recovery and Reinvestment Act of 2009 to stabilize soil and improve land-use practices in the Pelekane Bay watershed. The grant allowed the Kohala Watershed Partnership to implement various upland watershed management activities to reduce land-based sources of pollution into Pelekane Bay. However, a number of questions must be answered in order to: (1) evaluate the effectiveness of the terrestrial watershed remediation efforts; (2) understand the potential of the local marine ecosystem to recover; and (3) understand the potential threat that existing mud deposits in the bay pose to adjacent, relatively pristine coral reef ecosystems. The goal of this experiment was to help address these questions and establish a framework to evaluate the success of the Kohala Watershed Partnership restoration efforts. This research program will also provide resource managers with information relevant to other watershed restoration efforts currently being planned in neighboring watersheds. This project involved an interdisciplinary team of coral reef biologists from the University of Hawaii Coral Reef Assessment and Monitoring Program, who focused on the impact of sedimentation on the biota of Pelekane Bay, and a team of geologists and oceanographers from the U.S. Geological Survey (USGS), who focused on the

  1. Coastal Circulation and Sediment Dynamics in War-in-the-Pacific National Historical Park, Guam; measurements of waves, currents, temperature, salinity, and turbidity, June 2007-January 2008

    Science.gov (United States)

    Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.

    2009-01-01

    Flow in and around coral reefs affects a number of physical, chemical and biologic processes that influence the health and sustainability of coral reef ecosystems. These range from the residence time of sediment and contaminants to nutrient uptake and larval retention and dispersal. As currents approach a coast they diverge to flow around reef structures, causing high horizontal and vertical shear. This can result in either the rapid advection of material in localized jets, or the retention of material in eddies that form in the lee of bathymetric features. The high complexity and diversity both within and between reefs, in conjunction with past technical restrictions, has limited our understanding of the nature of flow and the resulting flux of physical, chemical, and biologic material in these fragile ecosystems. Sediment, nutrients, and other pollutants from a variety of land-based activities adversely impact many coral reef ecosystems in the U.S. and around the world. These pollutants are transported in surface water runoff, groundwater seepage, and atmospheric fallout into coastal waters, and there is compelling evidence that the sources have increased globally as a result of human-induced changes to watersheds. In Guam, and elsewhere on U.S. high islands in the Pacific and Caribbean, significant changes in the drainage basins due to agriculture, feral grazing, fires, and urbanization have in turn altered the character and volume of land-based pollution released to coral reefs. Terrigenous sediment run-off (and the associated nutrients and contaminants often absorbed to it) and deposition on coral reefs are recognized to potentially have significant impact on coral health by blocking light and inhibiting photosynthesis, directly smothering and abrading coral, and triggering increases in macro algae. Studies that combine information on watershed, surface water- and groundwater-flow, transport and fate of sediment and other pollutants in the reef environment

  2. Synoptic monthly gridded Global Temperature and Salinity Profile Programme (GTSPP) water temperature and salinity from January 1990 to December 2009 (NCEI Accession 0138647)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The synoptic gridded Global Temperature and Salinity Profile Programme (SG-GTSPP) provides world ocean 3D gridded temperature and salinity data in monthly increment...

  3. Bottom temperature and salinity distribution and its variability around Iceland

    Science.gov (United States)

    Jochumsen, Kerstin; Schnurr, Sarah M.; Quadfasel, Detlef

    2016-05-01

    The barrier formed by the Greenland-Scotland-Ridge (GSR) shapes the oceanic conditions in the region around Iceland. Deep water cannot be exchanged across the ridge, and only limited water mass exchange in intermediate layers is possible through deep channels, where the flow is directed southwestward (the Nordic Overflows). As a result, the near-bottom water masses in the deep basins of the northern North Atlantic and the Nordic Seas hold major temperature differences. Here, we use near-bottom measurements of about 88,000 CTD (conductivity-temperature-depth) and bottle profiles, collected in the period 1900-2008, to investigate the distribution of near-bottom properties. Data are gridded into regular boxes of about 11 km size and interpolated following isobaths. We derive average spatial temperature and salinity distributions in the region around Iceland, showing the influence of the GSR on the near-bottom hydrography. The spatial distribution of standard deviation is used to identify local variability, which is enhanced near water mass fronts. Finally, property changes within the period 1975-2008 are presented using time series analysis techniques for a collection of grid boxes with sufficient data resolution. Seasonal variability, as well as long term trends are discussed for different bottom depth classes, representing varying water masses. The seasonal cycle is most pronounced in temperature and decreases with depth (mean amplitudes of 2.2 °C in the near surface layers vs. 0.2 °C at depths > 500 m), while linear trends are evident in both temperature and salinity (maxima in shallow waters of +0.33 °C/decade for temperature and +0.03/decade for salinity).

  4. Sea-surface temperature and salinity mapping from remote microwave radiometric measurements of brightness temperature

    Science.gov (United States)

    Hans-Juergen, C. B.; Kendall, B. M.; Fedors, J. C.

    1977-01-01

    A technique to measure remotely sea surface temperature and salinity was demonstrated with a dual frequency microwave radiometer system. Accuracies in temperature of 1 C and in salinity of part thousand for salinity greater than 5 parts per thousand were attained after correcting for the influence of extraterrestrial background radiation, atmospheric radiation and attenuation, sea-surface roughness, and antenna beamwidth. The radiometers, operating at 1.43 and 2.65 GHz, comprise a third-generation system using null balancing and feedback noise injection. Flight measurements from an aircraft at an altitude of 1.4 km over the lower Chesapeake Bay and coastal areas of the Atlantic Ocean resulted in contour maps of sea-surface temperature and salinity with a spatial resolution of 0.5 km.

  5. Ocean acidification alters temperature and salinity preferences in larval fish.

    Science.gov (United States)

    Pistevos, Jennifer C A; Nagelkerken, Ivan; Rossi, Tullio; Connell, Sean D

    2017-02-01

    Ocean acidification alters the way in which animals perceive and respond to their world by affecting a variety of senses such as audition, olfaction, vision and pH sensing. Marine species rely on other senses as well, but we know little of how these might be affected by ocean acidification. We tested whether ocean acidification can alter the preference for physicochemical cues used for dispersal between ocean and estuarine environments. We experimentally assessed the behavioural response of a larval fish (Lates calcarifer) to elevated temperature and reduced salinity, including estuarine water of multiple cues for detecting settlement habitat. Larval fish raised under elevated CO2 concentrations were attracted by warmer water, but temperature had no effect on fish raised in contemporary CO2 concentrations. In contrast, contemporary larvae were deterred by lower salinity water, where CO2-treated fish showed no such response. Natural estuarine water-of higher temperature, lower salinity, and containing estuarine olfactory cues-was only preferred by fish treated under forecasted high CO2 conditions. We show for the first time that attraction by larval fish towards physicochemical cues can be altered by ocean acidification. Such alterations to perception and evaluation of environmental cues during the critical process of dispersal can potentially have implications for ensuing recruitment and population replenishment. Our study not only shows that freshwater species that spend part of their life cycle in the ocean might also be affected by ocean acidification, but that behavioural responses towards key physicochemical cues can also be negated through elevated CO2 from human emissions.

  6. The time-variable position of the Antarctic Circumpolar Current salinity fronts from Aquarius data

    Science.gov (United States)

    Volkov, D.; Dong, S.; Goni, G. J.

    2014-12-01

    The flow of the Antarctic Circumpolar Current (ACC) is known to be concentrated in a number of jets associated with fronts that are characterized by large horizontal gradients of temperature, salinity, sea surface height, and other variables. The processes of water mass transformation as well as the meridional energy and tracer transports in the Southern Ocean are most intense near the fronts and, therefore, it is important to establish their position and spatial extent. Based on historic hydrographic data, three major ACC fronts from north to south have been identified: the Subantarctic Front (SAF), the Polar Front (PF), and the Southern ACC Front (SACCF). Later, space-borne observations of sea surface temperature (SST) and sea surface height (SSH) as well as ocean model simulations have revealed a more complex frontal structure. As part of the validation of the Aquarius data and a demonstration of its capabilities and utility for oceanographic studies, we use along-track Aquarius data for the determination of the ACC sea surface salinity (SSS) fronts between Africa and Antarctica. The position of the fronts is determined from along-track salinity gradients and validated with concurrent SST- and SSH- derived frontal positions, as well as with the positions of temperature and salinity fronts obtained from several realizations of AX25 XBT and Good Hope CTD transects in 2011-2013. We find that some of the frontal positions that we have determined, although being representative only for one particular day, are close to the time mean positions obtained from hydrography. Thus, Aquarius data demonstrate its utility for studies of the variability of the ACC frontal positions. The SSS fronts are not necessarily collocated with SST and/or SSH fronts. The integral effects of temperature and salinity may compensate each other in the Southern Ocean, so that temperature and salinity fronts are not always associated with SSH fronts. Aquarius measurements thus complement SST and

  7. Response of benthic foraminifera Rosalina leei to different temperature and salinity, under laboratory culture experiment

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Kurtarkar, S.R.; Saraswat, R.; Linshy, V.N.; Rana, S.S.

    and 35 ppt saline water is most suitable for the growth of R. leei. Results are significant as the responses of benthic foraminifera to different temperatures and salinity are being used for palaeoclimatic reconstruction....

  8. Influence of temperature, oxygen and salinity on the metabolism of the European sea bass

    Science.gov (United States)

    Claireaux, G.; Lagardère, J.-P.

    1999-09-01

    Standard (SMR) and routine (RMR) metabolic rates of groups (4 to 5 individuals) of European sea bass ( Dicentrarchus labrax) were measured at combinations of the following factors: temperature (10, 15, 20 and 25°C), oxygenation level (air saturation to 1.5 mg dm -3) and salinity (30, 20, 10 and 5‰). The influence of these environmental conditions on fish metabolic demand was then analysed through ANOVA. At 10, 15, 20 and 25°C, standard metabolic rates were 36, 65, 89, and 91 mg O 2 kg -1 h -1, respectively, while routine oxygen consumptions covered most of the metabolic range accessible. Osmoregulatory costs are linked to metabolic activity through ventilation. This relationship was highlighted by the observed interaction between environmental salinity and temperature. We were, however, unable to detect interactions between salinity and routine metabolic rate, or between salinity and oxygenation level. In order to delineate more precisely the restrictions imposed by water oxygenation on fish metabolic performance we determined the limiting oxygen concentration curves at each experimental temperature. We followed up by modelling the bass active metabolic rate (AMR) and metabolic scope (MS) as functions of both ambient temperature and oxygenation. These mathematical models allowed the characterisation of the controlling and limiting effects of water temperature and oxygen content on the metabolic capacity of the species. Thus, AMR at 10, 15 and 20°C were estimated at 65, 160 and 360 mg O 2 kg -1 h -1, respectively. However, at higher temperature (25°C) AMR dropped slightly (to 340 mg O 2 kg -1 h -1). Bass MS increased by a factor of 9 between 10 and 20°C, but diminished at higher temperatures. The present study contributes to our current understanding of the influences of environmental factors on the metabolism of sea bass and provides a bioenergetic basis for a study of how environmental constraints govern the spatial and temporal distribution pattern of this

  9. Relative contributions of temperature and salinity to seasonal mixed layer density changes and horizontal density gradients

    OpenAIRE

    Johnson, Gregory C.; Schmidtko, Sunke; Lyman, John M.

    2012-01-01

    Temperature and salinity both contribute to ocean density, including its seasonal cycle and spatial patterns in the mixed layer. Temperature and salinity profiles from the Argo Program allow construction and analysis of a global, monthly, mixed layer climatology. Temperature changes dominate the seasonal cycle of mixed layer density in most regions, but salinity changes are dominant in the tropical warm pools, Arctic, and Antarctic. Under the Intertropical Convergence Zone, temperature and sa...

  10. Synergistic effects of altered salinity and temperature on estuarine eelgrass (Zostera marina) seedlings and clonal shoots

    DEFF Research Database (Denmark)

    Salo, Tiina Elina; Pedersen, Morten Foldager

    2014-01-01

    Salinity and temperature are among the most important factors determining eelgrass distribution and performance. Plants in estuarine environments experience large variations in both on a seasonal basis and exceptionally warm summers have caused massive die-backs of eelgrass in many areas. We...... investigated experimentally how different combinations of salinity and temperature affect the physiological performance of adult eelgrass (Zostera marina) shoots and seedlings. Plants were exposed to different combinations of salinity (salinity 5, 12.5 and 20) and temperature (15, 20 and 25 °C) in a 5-week...... aquarium experiment. Plants responded in general negatively to decreasing salinity and increasing temperature and the combination of high temperature and low salinity resulted in markedly higher mortality rates and lower leaf production when compared to plants held at more optimal combinations of salinity...

  11. Tolerance, Oxygen Consumption and Ammonia Excretion ofOphiopholis sarsii vadicola in Different Temperatures and Salinities

    Institute of Scientific and Technical Information of China (English)

    FANG Jinghui; ZHANG Jihong; JIANG Zengjie; ZHAO Xuewei; JIANG Xu; DU Meirong; GAO Yaping

    2015-01-01

    There are more than 2000 species of brittle stars in the world. For most of them, many scientific questions including basic characteristics of eco-physiology are still unknown. In the present study,Ophiopholis sarsii vadicola acclimated at 15℃, salinity 31, were assessed for temperature and salinity tolerance. Its oxygen consumption and am-monia excretion were studied at different temperatures (5, 10, 15, 20, 25℃) and salinities (25, 30, 35).O. sarsii vadi-cola could tolerate 0–24℃ and no brittle star was dead in the salinity range of 19–48 in the experimental situation. Two-way ANOVA showed that the oxygen consumption and ammonia excretion normalized with both dry mass and wet mass,Q10, which is used to describe the temperature sensitivity of respiration, and moisture content were significantly affected by temperature and salinity, and the combined effects of the two factors were significant. Stepwise multiple regression analysis revealed that logarithmic oxygen consumption and ammonia excretion showed a significant positive relationship with logarithmic temperature and salinity. The logarithmic moisture content of the brittle stars showed an inverse relationship with logarithmic salinity, but a positive relationship with logarithmic temperature. This suggests that the tolerance of temperature and salinity of brittle stars is closely related to their living environment, and that the effects of temperature on oxygen consumption are more significant at higher salinity, and that the ammonia excretion is less affected by salinity at lower temperatures.

  12. Salinity, Temperature and Turbidity Structure in the Suva Lagoon, Fiji

    Directory of Open Access Journals (Sweden)

    Awnesh Singh

    2008-01-01

    Full Text Available The city of Suva is home to nearly a quarter of the population of the Fiji thereby placing a lot of anthropogenic pressure on its lagoon. The Suva lagoon (comprising of Suva Harbour and Laucala Bay has been subject to substantial sediment inputs generated by erosion and human activities. Freshwater input into the lagoon comes predominantly from the Rewa River, the largest fluvial system in the country. The high sedimentary load from the Rewa River, especially during the wet-warm period (November-April, has a strong impact on the lagoon. In addition, there are local sources of pollutant input into the lagoon via the Vatuwaqa River and the Kinoya Sewage Treatment Plant, which discharges effluents into the lagoon and degrades the marine environment. The salinity, temperature and turbidity in the Suva lagoon are some important parameters for water quality which are continuously changing with the seasons and need to be studied because they are efficient indicators of variations in the lagoon and can transform the marine ecosystem. Several field trips were undertaken in the Suva lagoon to collect hydrographical data to study the water properties in the lagoon. Results obtained showed that the salinity near the head of Laucala Bay during the wet-warm period was below 24.8 psu and was 33.7 psu during the dry-cool period (May - October. The temperature range during the wet-warm period was between 28.0-30.5°C and between 24.5-25.5°C during the dry-cool period. The turbidity was always above 3.0 FTU near the river mouths. The field results show that the variations of CTD measurements are dependent predominantly on the river discharge, while the dominant wind regime is the southeast trade winds.

  13. Dynamics Study of the Influence of Temperature on Konjac Glucomannan Saline Solution's Viscosity

    Institute of Scientific and Technical Information of China (English)

    PANG Jie; SUN Yu-Jing; ZHUANG Yu; YE Bing-Hong; SUN Yuan-Ming

    2008-01-01

    Molecular dynamics(MD)method is adopted to simulate the conformation variations of konjac glucomannan (KGM) saline solution at different temperatures, and structurally analyze the trends and reasons of viscosity change in KGM saline solution with temperature. The experimental results have been analyzed to find out that the sum of formative hydrogen bonds decreases with the rise of temperature and the amount of intramolecular hydrogen bonds suddenly increases at 323 K.Besides, in terms of molecular orbital data obtained from simulation, we can know that hydrogen bonding energy also decreases with the rise of temperature. Therefore, we can predict the viscosity of KGM saline solution decreases gradually when rising the temperature.

  14. Salinity and temperature tolerance of an emergent alien species, the Amazon fish Astronotus ocellatus

    Science.gov (United States)

    Gutierrel, Silvia M M; Schofield, Pam; Prodocimo, Viviane

    2016-01-01

    Astronotus ocellatus (oscar), is native to the Amazon basin and, although it has been introduced to many countries, little is known regarding its tolerances for salinity and temperature. In this report, we provide data on the tolerance of A. ocellatus to abrupt and gradual changes in salinity, its high and low temperature tolerance, and information on how salinity, temperature, and fish size interact to affect survival. Fish were able to survive abrupt transfer to salinities as high as 16 ppt with no mortality. When salinity change was gradual (2 ppt/day), fish in the warm-temperature experiment (28°C) survived longer than fish in the cool-temperature experiment (18°C). Larger fish survived longer than smaller ones at the higher salinities when the temperature was warm, but when the temperature was cool fish size had little effect on survival. In the temperature-tolerance experiments, fish survived from 9 to 41°C for short periods of time. Overall, the species showed a wide range of temperature and salinity tolerance. Thus, in spite of the tropical freshwater origin of this species, physiological stress is not likely to hinder its dispersal to brackish waters, especially when temperatures are warm.

  15. Improved statistical method for temperature and salinity quality control

    Science.gov (United States)

    Gourrion, Jérôme; Szekely, Tanguy

    2017-04-01

    Climate research and Ocean monitoring benefit from the continuous development of global in-situ hydrographic networks in the last decades. Apart from the increasing volume of observations available on a large range of temporal and spatial scales, a critical aspect concerns the ability to constantly improve the quality of the datasets. In the context of the Coriolis Dataset for ReAnalysis (CORA) version 4.2, a new quality control method based on a local comparison to historical extreme values ever observed is developed, implemented and validated. Temperature, salinity and potential density validity intervals are directly estimated from minimum and maximum values from an historical reference dataset, rather than from traditional mean and standard deviation estimates. Such an approach avoids strong statistical assumptions on the data distributions such as unimodality, absence of skewness and spatially homogeneous kurtosis. As a new feature, it also allows addressing simultaneously the two main objectives of an automatic quality control strategy, i.e. maximizing the number of good detections while minimizing the number of false alarms. The reference dataset is presently built from the fusion of 1) all ARGO profiles up to late 2015, 2) 3 historical CTD datasets and 3) the Sea Mammals CTD profiles from the MEOP database. All datasets are extensively and manually quality controlled. In this communication, the latest method validation results are also presented. The method has already been implemented in the latest version of the delayed-time CMEMS in-situ dataset and will be deployed soon in the equivalent near-real time products.

  16. Influence of Temperature and Salinity on Germination of Eelgrass (Zostera marina L.) Seeds

    Institute of Scientific and Technical Information of China (English)

    PAN Jinhua; YANG Guanpin; JIANG Xin; LI Xiaojie; CONG Yizhou; ZHANG Zhuangzhi; LI Zhiling; ZHOU Weili; HAN Houwei; LUO Shiju

    2011-01-01

    Seagrass restoration as part of ocean ecosystem protection has been launched for many years all over the world, but intensive research on this subject in China has just begun in recent years. Seed broadcasting has been widely accepted as the most potentially useful method for seagrass restoration over large areas. We examined the influence of key environmental factors on seed germination to help promote eelgrass bed restoration. Under anoxic conditions, the influence of temperature and salinity on the germination rate of eelgrass (Zostera marina L.) seeds was examined at different combinations of four temperatures (4, 9, 14, and 24℃) and nine salinities (5 to 45, increment of 5). The effect of significant interaction of temperature and salinity on germination rate was observed (ANOVA)(P<0.001). The highest germination rate (83.3 ±3.5)% was reached in 8 weeks at 14℃ and salinity 5. Higher temperature significantly increased the germination rate at salinity 5 (P<0.001) during the whole observation period except for 24℃,while lower salinity significantly increased the germination rate at 14℃ (P<0.001). Although significant interaction was found between temperature and salinity (P<0.001), the influence of salinity was stronger than that of temperature for the germination of eelgrass seeds. These results provide useful information for the propagation of artificial seedlings for seagrass restoration in China.

  17. Holocene Oscillations in the Temperature and Salinity of the Surface Subpolar North Atlantic

    Science.gov (United States)

    Thornalley, D. J.; Elderfield, H.; McCave, N.

    2008-12-01

    The Atlantic meridional overturning circulation (AMOC) transports warm and salty surface waters to high latitudes (via the North Atlantic Current, NAC), where they cool, sink, and return southwards at depth. Through its attendant meridional heat transport, the AMOC helps maintain a warm NW European climate, and acts as a control on global climate. Yet our ability to test hypotheses about AMOC behavior during periods of climate change is limited by the short time period for which instrumental data is available. To address this problem, we reconstruct the temperature and salinity of the NAC using paired δ18O-Mg/Ca measurements of foraminifera from ocean sediment core RAPiD-12-1K, located on the South Iceland Rise, throughout the Holocene (0-11.7 ka). The records are interpreted by examining the modern controls on the hydrography of the region. The paleo data then in turn provides support for recent modeling studies of AMOC behavior, thus providing an integrated view of ocean dynamics. G. bulloides data reveal millennial timescale salinity variations (~0.5 psu) superimposed upon a trend of increasing near-surface water salinity from ~9 ka to the present. The shorter timescale variability is likely due to southward advances of the subpolar front, analogous to the changes observed during the NAO minimum during the 1960s. The long term trend in near surface salinity may be caused by shifts in the ITCZ and the input of deglacial meltwater. G. inflata data show that below the seasonal thermocline the NAC has undergone millennial variations in temperature and salinity (~3.5°C and ~1.5 psu). These are controlled by subpolar gyre dynamics, consistent with modern studies of inter-annual to decadal timescale behavior. The inflow becomes more saline during enhanced freshwater flux to the subpolar North Atlantic, suggesting a negative feedback is in operation on millennial timescales. The AMOC may therefore be more stable than previously expected during future global warming

  18. High temperature superconducting fault current limiter

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL)

    1997-01-01

    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  19. Currents, temperature, and salinity data recorded continuously from May 12, 2010 to December 16, 2010 from the surface to 1000 meters at a coastal location near the 1600 meters isobath off SW Oahu, Hawaii (NODC Accession 0072305)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains ADCP Workhorse Long Ranger current records from 50 to 950m depth and Seabird CTD at 20, 80, 130, 230, 500, 850, and 1000m, recorded continuously...

  20. Real-time current, wave, temperature, salinity, and meteorological data from Gulf of Maine Ocean Observing System (GoMOOS) buoys, 11/30/2003 - 12/7/2003 (NODC Accession 0001259)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Gulf of Maine Ocean Observing System (GoMOOS) collected real-time data with buoy-mounted instruments (e.g., accelerometers and Acoustic Doppler Current...

  1. Metabolism of polychaete Neanthes japonica Izuka: relations to temperature, salinity and body weight

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; XIAN Weiwei; SUN Shichun

    2009-01-01

    Polychaete Neanthesjaponica is a species geographically specific in China and Japan with important scientific implication and commercial value. In this study, the relations of body weight, salinity and temperature to oxygen consumption and ammonia excretion of N. japonica were determined. Threedifferent groups in body weight (large: 2.34±0.36 g, middle: 1.50±0.21 g and small: 0.62±0.12 g) were set for all experiments. Results show that the body weight is negatively related to the rates of oxygen consumption and ammonia excretion; and the relationship is significant. The oxygen consumption and ammonia excretion at 24℃ decreased at salinity from 5 to 30 and increased above 30, indicating that both lower and higher salinity are adverse and certain degree of salinity stress is necessary for enhancing the energy demand. At salinity 30, rising temperature from 18℃ to 30℃, the oxygen consumption increased before 27℃ and then decreased. However, the relation of ammonia excretion and temperature seems more complex. Two-way ANOVA shows that salinity, temperature and body weight all have a significant effect on the oxygen consumption and ammonia excretion of the worm. Moreover, interaction between salinity/temperature and body weight is also significant. O:N (oxygen/nitrogen) ratio varies greatly in this case from 5.97 to 463.22, indicating that N. japonica can regulate the type of metabolic substrate against environment changes.

  2. Impact of sea surface temperature on satellite retrieval of sea surface salinity

    Science.gov (United States)

    Jin, Xuchen; Zhu, Qiankun; He, Xianqiang; Chen, Peng; Wang, Difeng; Hao, Zengzhou; Huang, Haiqing

    2016-10-01

    Currently, global sea surface salinity (SSS) can be retrieved by the satellite microwave radiometer onboard the satellite, such as the Soil Moisture and Ocean Salinity(SMOS) and the Aqurius. SMOS is an Earth Explorer Opportunity Mission from the European Space Agency(ESA). It was launched at a sun-synchronous orbit in 2009 and one of the payloads is called MIRAS(Microwave Imaging Radiometer using Aperture Synthesis), which is the first interferometric microwave radiometer designed for observing SSS at L-band(1.41 GHz).The foundation of the salinity retrieval by microwave radiometer is that the sea surface radiance at L-band has the most suitable sensitivity with the variation of the salinity. It is well known that the sensitivity of brightness temperatures(TB) to SSS depends on the sea surface temperature (SST), but the quantitative impact of the SST on the satellite retrieval of the SSS is still poorly known. In this study, we investigate the impact of the SST on the accuracy of salinity retrieval from the SMOS. First of all, The dielectric constant model proposed by Klein and Swift has been used to estimate the vertically and horizontally polarized brightness temperatures(TV and TH) of a smooth sea water surface at L-band and derive the derivatives of TV and TH as a function of SSS to show the relative sensitivity at 45° incident angle. Then, we use the GAM(generalized additive model) method to evaluate the association between the satellite-measured brightness temperature and in-situ SSS at different SST. Moreover, the satellite-derived SSS from the SMOS is validated using the ARGO data to assess the RMSE(root mean squared error). We compare the SMOS SSS and ARGO SSS over two regions of Pacific ocean far from land and ice under different SST. The RMSE of retrieved SSS at different SST have been estimated. Our results showed that SST is one of the most significant factors affecting the accuracy of SSS retrieval. The satellite-measured brightness temperature has a

  3. Oscillating Adriatic temperature and salinity regimes mapped using the Self-Organizing Maps method

    Science.gov (United States)

    Matić, Frano; Kovač, Žarko; Vilibić, Ivica; Mihanović, Hrvoje; Morović, Mira; Grbec, Branka; Leder, Nenad; Džoić, Tomislav

    2017-01-01

    This paper aims to document salinity and temperature regimes in the middle and south Adriatic Sea by applying the Self-Organizing Maps (SOM) method to the available long-term temperature and salinity series. The data were collected on a seasonal basis between 1963 and 2011 in two dense water collecting depressions, Jabuka Pit and Southern Adriatic Pit, and over the Palagruža Sill. Seasonality was removed prior to the analyses. Salinity regimes have been found to oscillate rapidly between low-salinity and high-salinity SOM solutions, ascribed to the advection of Western and Eastern Mediterranean waters, respectively. Transient salinity regimes normally lasted less than a season, while temperature transient regimes lasted longer. Salinity regimes prolonged their duration after the major basin-wide event, the Eastern Mediterranean Transient, in the early 1990s. A qualitative relationship between high-salinity regimes and dense water formation and dynamics has been documented. The SOM-based analyses have a large capacity for classifying the oscillating ocean regimes in a basin, which, in the case of the Adriatic Sea, beside climate forcing, is an important driver of biogeochemical changes that impacts trophic relations, appearance and abundance of alien organisms, and fisheries, etc.

  4. Impacts of salinity parameterizations on temperature simulation over and in a hypersaline lake

    Science.gov (United States)

    Wen, Lijuan; Nagabhatla, Nidhi; Zhao, Lin; Li, Zhaoguo; Chen, Shiqiang

    2015-05-01

    In this paper, we introduced parameterizations of the salinity effects (on heat capacity, thermal conductivity, freezing point and saturated vapor pressure) in a lake scheme integrated in the Weather Research and Forecasting model coupled with the Community Land Model (WRF-CLM). This was done to improve temperature simulation over and in a saline lake and to test the contributions of salinity effects on various water properties via sensitivity experiments. The modified lake scheme consists of the lake module in the CLM model, which is the land component of the WRF-CLM model. The Great Salt Lake (GSL) in the USA was selected as the study area. The simulation was performed from September 3, 2001 to September 30, 2002. Our results show that the modified WRF-CLM model that includes the lake scheme considering salinity effects can reasonably simulate temperature over and in the GSL. This model had much greater accuracy than neglecting salinity effects, particularly in a very cold event when that effect alters the freezing point. The salinity effect on saturated vapor pressure can reduce latent heat flux over the lake and make it slightly warmer. The salinity effect on heat capacity can also make lake temperature prone to changes. However, the salinity effect on thermal conductivity was found insignificant in our simulations.

  5. NODC Standard Product: Global ocean temperature and salinity profiles (2 disc set) (NODC Accession 0098058)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This set of CD-ROMs contains global ocean temperature and salinity profiles derived from NODC archive data files. It includes oceanographic station (bottle) data,...

  6. A Parameter Identification Method to Determine Salinity of Sea Ice Using Temperature and Thickness Observations

    Science.gov (United States)

    Lv, Wei; Li, Xiaojiao; Feng, Enmin

    2014-02-01

    This study is intended to provide a parameter identification method to determine the salinity of sea ice using temperature and thickness measurements. This method is particularly effective when field data are sparse and unsatisfactory due to the difficulties associated with fieldwork, especially during the polar winter. The main idea of the method is described. The salinity profile is calculated by the temperature and thickness observations, which were measured at Nella Fjord around Zhongshan Station, Antarctica during the polar night time by the 22nd Chinese Antarctic Research Expedition. Another simulation for temperature profiles during a different measurement period is performed. Results show that better simulations of the salinity and temperature distributions are possible with the estimated parameters than with Eicken's and THESCI's methods. This method will help people to understand the salinity evolution of sea ice more thoroughly.

  7. AN EXPERIMENTAL DATASET: Underway Sea Surface Temperature and Salinity Aboard the Oleander

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data being submitted to NODC contain information about temperature and salinity obtained with the use of thermosalinographs (TSG) installed in ships of the NOAA...

  8. Temperature, salinity, and other measurements collected using gliders in the Gulf of Mexico (NODC Accession 0065238)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Glider oceanographic data (temperature, salinity) collected in support of the Deepwater Horizon oil spill event in the Gulf of Mexico (NODC Accession 0065238).

  9. NODC Standard Product: Climatic Atlas of the Barents Sea 1998: Temperature, Salinity, Oxygen (NODC Accession 0000300)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This NODC CD-ROM product (NODC-121) contains the time and space distribution of 74,256 ocean stations (temperature, salinity, and oxygen) occupied in the Barents Sea...

  10. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1981 to 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1981 to 2005 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  11. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1956 to 1980

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1956 to 1980 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  12. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1912 to 1930

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1912 to 1930 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  13. Oceanographic profile temperature and salinity from JCAD-6 drifting buoy 2003-2004 (NODC Accession 0002236)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic profile temperature and salinity measurements collected using a drifting buoy in the Arctic from 2003 to 2004 (NODC Accession 0002236).

  14. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1931 to 1955

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1931 to 1955 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  15. Oxygen consumption and ammonia-N excretion of Meretrix meretrix in different temperature and salinity

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Effects of temperatures and salinities on oxygen consumption and ammonia-N excretion rate of clam Meretrix meretrix were studied in laboratory from Oct. 2003 to Jan. 2004. Two schemes were designed in incremented temperature at 10, 15, 20, 25℃ at 31.5 salinity and in incremented salinity at l6.0, 21.0, 26.0, 31.5,36.0, and 41.0 at 20℃, all for 8-10 days. From 10 to 25℃, both respiration and excretion rate were increased.One-way ANOVA analysis demonstrated significant difference (P<0.01) in physiological parameters in this temperature range except between 15 and 20℃. The highest Q10 thermal coefficient value (12.27) was acquired between 10 and 15℃, and about 1 between 15 and 20℃, indicating M. meretrix could well acclimate to temperature changes in this range. Salinity also had significant effects on respiration and excretion rate (P<0.05).The highest values of respiration and excretion rate of M. meretrix were recorded at 16.0 salinity (20℃). These two physiological parameters decreased as salinity increased until reached the minimum Q10 value at 31.5 (20℃),then again, these parameters increased with increasing salinity from 31.5 to 41.0. M. meretrix can catabolize body protein to cope with osmotic pressure stress when environmental salinity is away from its optimal range.No significant difference was observed between 26.0 and 36.0 in salinity (P>0.05), suggesting that a best metabolic salinity range for this species is between 26.0 and 36.0.

  16. Retrieving Marine Inherent Optical Properties from Satellites Using Temperature and Salinity-dependent Backscattering by Seawater

    Science.gov (United States)

    Werdell, Paul J.; Franz, Bryan Alden; Lefler, Jason Travis; Robinson, Wayne D.; Boss, Emmanuel

    2013-01-01

    Time-series of marine inherent optical properties (IOPs) from ocean color satellite instruments provide valuable data records for studying long-term time changes in ocean ecosystems. Semi-analytical algorithms (SAAs) provide a common method for estimating IOPs from radiometric measurements of the marine light field. Most SAAs assign constant spectral values for seawater absorption and backscattering, assume spectral shape functions of the remaining constituent absorption and scattering components (e.g., phytoplankton, non-algal particles, and colored dissolved organic matter), and retrieve the magnitudes of each remaining constituent required to match the spectral distribution of measured radiances. Here, we explore the use of temperature- and salinity-dependent values for seawater backscattering in lieu of the constant spectrum currently employed by most SAAs. Our results suggest that use of temperature- and salinity-dependent seawater spectra elevate the SAA-derived particle backscattering, reduce the non-algal particles plus colored dissolved organic matter absorption, and leave the derived absorption by phytoplankton unchanged.

  17. Plasma osmolality and oxygen consumption of perch Perca fluviatilis in response to different salinities and temperatures

    DEFF Research Database (Denmark)

    Christensen, Emil Aputsiaq Flindt; Svendsen, Morten Bo Søndergaard; Steffensen, John Fleng

    2017-01-01

    The present study determined the blood plasma osmolality and oxygen consumption of the perch Perca fluviatilis at different salinities (0, 10 and 15) and temperatures (5, 10 and 20° C). Blood plasma osmolality increased with salinity at all temperatures. Standard metabolic rate (SMR) increased...... beneficial during cold periods (winter). It is suggested, therefore, that the seasonal migrations of P. fluviatilis between brackish and fresh water is to select an environment that is optimal for metabolism and aerobic scope....

  18. High temperature superconductor current leads

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL); Poeppel, Roger B. (Glen Ellyn, IL)

    1995-01-01

    An electrical lead having one end for connection to an apparatus in a cryogenic environment and the other end for connection to an apparatus outside the cryogenic environment. The electrical lead includes a high temperature superconductor wire and an electrically conductive material distributed therein, where the conductive material is present at the one end of the lead at a concentration in the range of from 0 to about 3% by volume, and at the other end of the lead at a concentration of less than about 20% by volume. Various embodiments are shown for groups of high temperature superconductor wires and sheaths.

  19. Coastal circulation and water-column properties in the War in the Pacific National Historical Park, Guam: measurements and modeling of waves, currents, temperature, salinity, and turbidity, April-August 2012

    Science.gov (United States)

    Storlazzi, Curt D.; Cheriton, Olivia M.; Lescinski, Jamie M.R.; Logan, Joshua B.

    2014-01-01

    The U.S. Geological Survey (USGS) Pacific Coastal and Marine Science Center (PCMSC) initiated an investigation in the National Park Service’s (NPS) War in the Pacific National Historical Park (WAPA) to provide baseline scientific information on coastal circulation and water-column properties along west-central Guam, focusing on WAPA’s Agat Unit, as it relates to the transport and settlement of coral larvae, fish, and other marine organisms. The oceanographic data and numerical circulation modeling results from this study demonstrate that circulation in Agat Bay was strongly driven by winds and waves at longer (>1 day) timescales and by the tides at shorter (Turbidity was relatively low in Agat Bay and was similar to levels measured elsewhere along west-central Guam. The numerical circulation modeling results provide insight into the potential paths of buoyant material released from a series of locations along west-central Guam under summer non-trade wind forcing conditions that characterize coral spawning events. This information may be useful in evaluating the potential zones of influence/impact resulting from transport by surface currents of material released from these select locations.

  20. Etched FBG coated with polyimide for simultaneous detection the salinity and temperature

    Science.gov (United States)

    Luo, Dong; Ma, Jianxun; Ibrahim, Zainah; Ismail, Zubaidah

    2017-06-01

    In marine environment, concrete structures can corrode because of the PH alkalinity of concrete paste; and the salinity PH is heavily related with the concentration of salt in aqueous solutions. In this study, an optical fiber salinity sensor is proposed on the basis of an etched FBG (EFBG) coated with a layer of polyimide. Chemical etching is employed to reduce the diameter of FBG and to excite Cladding Mode Resonance Wavelengths (CMRWs). CMRW and Fundamental Mode Resonance Wavelength (FMRW) can be used to measure the Refractive index (RI) and temperature of salinity. The proposed sensor is then characterized with a matrix equation. Experimental results show that FMRW and 5th CMRW have the detection sensitivities of 15.407 and 125.92 nm/RIU for RI and 0.0312 and 0.0435 nm/°C for temperature, respectively. The proposed sensor can measure salinity and temperature simultaneously.

  1. Observations of Seasonal Variations in Sea Bottom Temperature and Salinity in Bykovsky Bay in the Laptev Sea

    Science.gov (United States)

    Overduin, P. P.; Grigoriev, M. N.; Kopsch, C.

    2009-04-01

    Following inundation due to coastal erosion or increasing relative sea level, flooded permafrost is separated from the atmosphere by sea ice and water. The boundary condition for further permafrost evolution is given by seabed salinity and temperature. Few records of seasonal variations in these parameters exist, limiting our ability to predict the speed of subsea peramfrost degradation, or to correlate borehole observations with near-shore processes. For subsea permafrost, seabottom temperature drives sediment warming and variations in salinity can increase the rate of penetration of the seawater salt front into the sediment. A borehole transect drilled in 1983 in the nearshore zone off Mamontovy Khayata on the Bykovsky Peninsula in the Laptev Sea resulted in a description of subsea sediment temperature and the inclination of the top of the ice-bearing permafrost perpendicular to the coast out to a distance of 3 km. Before erosion, the landscape at Mamontovy Khayata is composed of ice-rich periglacial deposits down to and beneath current sea level, most of which are removed during erosion. Thermokarst features dominate the landscape and affect coastal bluff height and the resilience of sediments to coastal erosion and abrasion. We installed dataloggers on the seabed in 2007 to measure bottom water temperature and salinity at hourly intervals. Temperature variations are higher than expected, and together with salinity demonstrate the changing seasonal importance of warm, fresh river water and colder, saltier sea water that has been observed elsewhere. During winter, bottom water temperatures stabilize at the freezing point, but rise slowly during the winter, during a period of increasing salinity. We propose that this warming corresponds to the loss of heat from the underlying sediment. We compare integrated rates of warming of subsea and terrestrial permafrost and estimate the increase in the rate of subsea permafrost thermal degradation after inundation.

  2. High resolution 3-D temperature and salinity fields derived from in situ and satellite observations

    Directory of Open Access Journals (Sweden)

    S. Guinehut

    2012-10-01

    Full Text Available This paper describes an observation-based approach that efficiently combines the main components of the global ocean observing system using statistical methods. Accurate but sparse in situ temperature and salinity profiles (mainly from Argo for the last 10 yr are merged with the lower accuracy but high-resolution synthetic data derived from satellite altimeter and sea surface temperature observations to provide global 3-D temperature and salinity fields at high temporal and spatial resolution. The first step of the method consists in deriving synthetic temperature fields from altimeter and sea surface temperature observations, and salinity fields from altimeter observations, through multiple/simple linear regression methods. The second step of the method consists in combining the synthetic fields with in situ temperature and salinity profiles using an optimal interpolation method. Results show the revolutionary nature of the Argo observing system. Argo observations now allow a global description of the statistical relationships that exist between surface and subsurface fields needed for step 1 of the method, and can constrain the large-scale temperature and mainly salinity fields during step 2 of the method. Compared to the use of climatological estimates, results indicate that up to 50% of the variance of the temperature fields can be reconstructed from altimeter and sea surface temperature observations and a statistical method. For salinity, only about 20 to 30% of the signal can be reconstructed from altimeter observations, making the in situ observing system essential for salinity estimates. The in situ observations (step 2 of the method further reduce the differences between the gridded products and the observations by up to 20% for the temperature field in the mixed layer, and the main contribution is for salinity and the near surface layer with an improvement up to 30%. Compared to estimates derived using in situ observations only, the

  3. High Resolution 3-D temperature and salinity fields derived from in situ and satellite observations

    Directory of Open Access Journals (Sweden)

    S. Guinehut

    2012-03-01

    Full Text Available This paper describes an observation-based approach that combines efficiently the main components of the global ocean observing system using statistical methods. Accurate but sparse in situ temperature and salinity profiles (mainly from Argo for the last 10 years are merged with the lower accuracy but high-resolution synthetic data derived from altimeter and sea surface temperature satellite observations to provide global 3-D temperature and salinity fields at high temporal and spatial resolution. The first step of the method consists in deriving synthetic temperature fields from altimeter and sea surface temperature observations and salinity fields from altimeter observations through multiple/simple linear regression methods. The second step of the method consists in combining the synthetic fields with in situ temperature and salinity profiles using an optimal interpolation method. Results show the revolution of the Argo observing system. Argo observations now allow a global description of the statistical relationships that exist between surface and subsurface fields needed for step 1 of the method and can constrain the large-scale temperature and mainly salinity fields during step 2 of the method. Compared to the use of climatological estimates, results indicate that up to 50 % of the variance of the temperature fields can be reconstructed from altimeter and sea surface temperature observations and a statistical method. For salinity, only about 20 to 30 % of the signal can be reconstructed from altimeter observations, making the in situ observing system mandatory for salinity estimates. The in situ observations (step 2 of the method reduce additionally the error by up to 20 % for the temperature field in the mixed layer and the main contribution is for salinity and the near surface layer with an improvement up to 30 %. Compared to estimates derived using in situ observations only, the merged fields provide a better reconstruction of the high

  4. Metabolic rates of the antarctic amphipod Gondogeneia antarctica at different temperatures and salinities

    Directory of Open Access Journals (Sweden)

    Vicente Gomes

    2013-12-01

    Full Text Available Changes in environmental factors may deeply affect the energy budget of Antarctic organisms as many of them are stenothermal and/or stenohaline ectotherms. In this context, the aim of this study is to contribute to knowledge on variations in the energy demand of the Antarctic amphipod, Gondogeneia antarctica as a function of temperature and salinity. Experiments were held at the Brazilian Antarctic Station "Comandante Ferraz", under controlled conditions. Animals collected at Admiralty Bay were acclimated to temperatures of 0ºC; 2.5ºC and 5ºC and to salinities of 35, 30 and 25. Thirty measurements were made for each of the nine combinations of the three temperatures and three salinities, totalling 270 measurements. Metabolic rates were assessed by oxygen consumption and total nitrogenous ammonia excretion, in sealed respirometers. When acclimated to salinities 30 or 35, metabolic rates at 0ºC and 2.5ºC were very similar indicating a possible mechanism of metabolic compensation for temperature. At 5.0ºC, however, metabolic rates were always higher. Lower salinities enhanced the effects of temperature on metabolism and ammonia excretion rates. The physiological adaptations of individuals of G. antarctica suggest adaptive mechanisms for energy saving, adjusted to an environment with stable conditions of temperature and salinity. Little is known about the joint effects of salinity and temperature and this study is an important contribution to the understanding of the mechanism of polar organisms in their adaptation to both factors.

  5. Current and temperature structure of Rihand Lake

    Digital Repository Service at National Institute of Oceanography (India)

    Suryanarayana, A.; Swamy, G.N.; Sadhuram, Y.

    on the vertical as well as horizontal temperature structure of the lake. The surface currents are highly variable due to wind but mostly follow the depth contours. The bottom waters of the deepest area seem to be stagnant as seen from the current and temperature...

  6. Holocene oscillations in temperature and salinity of the surface subpolar North Atlantic.

    Science.gov (United States)

    Thornalley, David J R; Elderfield, Harry; McCave, I Nick

    2009-02-05

    The Atlantic meridional overturning circulation (AMOC) transports warm salty surface waters to high latitudes, where they cool, sink and return southwards at depth. Through its attendant meridional heat transport, the AMOC helps maintain a warm northwestern European climate, and acts as a control on the global climate. Past climate fluctuations during the Holocene epoch ( approximately 11,700 years ago to the present) have been linked with changes in North Atlantic Ocean circulation. The behaviour of the surface flowing salty water that helped drive overturning during past climatic changes is, however, not well known. Here we investigate the temperature and salinity changes of a substantial surface inflow to a region of deep-water formation throughout the Holocene. We find that the inflow has undergone millennial-scale variations in temperature and salinity ( approximately 3.5 degrees C and approximately 1.5 practical salinity units, respectively) most probably controlled by subpolar gyre dynamics. The temperature and salinity variations correlate with previously reported periods of rapid climate change. The inflow becomes more saline during enhanced freshwater flux to the subpolar North Atlantic. Model studies predict a weakening of AMOC in response to enhanced Arctic freshwater fluxes, although the inflow can compensate on decadal timescales by becoming more saline. Our data suggest that such a negative feedback mechanism may have operated during past intervals of climate change.

  7. Dynamics of harmful dinoflagellates driven by temperature and salinity in a northeastern Mediterranean lagoon.

    Science.gov (United States)

    Dhib, Amel; Frossard, Victor; Turki, Souad; Aleya, Lotfi

    2013-04-01

    To attempt to determine the effects of temperature and salinity on the dynamics of the dinoflagellate community, a monthly sampling was carried out from October 2008 to March 2009 at eight sampling stations in Ghar El Melh Lagoon (GML; Mediterranean Sea, Northern Tunisia). Dinoflagellates were dominant among plankton, accounting for 73.9 % of the lagoon's overall plankton community, and were comprised of 25 different species among which 17 were reported in the literature as harmful. While no significant difference was found in the distribution of dinoflagellates among the stations, a strong monthly difference was observed. This temporal variability was due to an increase in the abundance of Prorocentrum micans from December to February, leading to a strong decrease in the Shannon diversity index from station to station. At the onset of P. micans development, dinoflagellate abundances reached 1.26.10(5) cells l(-1). A redundance analysis indicates that both temperature and salinity have a significant effect on the dynamics of the dinoflagellate community. Using a generalized additive model, both temperature and salinity appear to have significant nonlinear relationships with P. micans abundances. Model predictions indicate that outbreaks of P. micans may occur at a temperature below 22.5 °C and with salinity above 32.5. We discuss our results against a backdrop of climate change which, by affecting temperature and salinity, is likely to have an antagonistic impact on P. micans development and subsequently on the dinoflagellate dynamics in GML.

  8. Andreev current for low temperature thermometry

    Energy Technology Data Exchange (ETDEWEB)

    Faivre, T., E-mail: timothe.faivre@aalto.fi; Pekola, J. P. [Low Temperature Laboratory, Department of Applied Physics, Aalto University School of Science, P.O. Box 13500, FI-00076 Aalto (Finland); Golubev, D. S. [Low Temperature Laboratory, Department of Applied Physics, Aalto University School of Science, P.O. Box 13500, FI-00076 Aalto (Finland); Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology, 76021 Karlsruhe (Germany)

    2015-05-04

    We demonstrate experimentally that disorder enhanced Andreev current in a tunnel junction between a normal metal and a superconductor provides a method to measure electronic temperature, specifically at temperatures below 200 mK when aluminum is used. This Andreev thermometer has some advantages over conventional quasiparticle thermometers: For instance, it does not conduct heat and its reading does not saturate until at lower temperatures. Another merit is that the responsivity is constant over a wide temperature range.

  9. Progressive acclimation alters interaction between salinity and temperature in experimental Daphnia populations.

    Science.gov (United States)

    Loureiro, Cláudia; Cuco, Ana P; Claro, Maria Teresa; Santos, Joana I; Pedrosa, M Arminda; Gonçalves, Fernando; Castro, Bruno B

    2015-11-01

    Environmental stressors rarely act in isolation, giving rise to interacting environmental change scenarios. However, the impacts of such interactions on natural populations must consider the ability of organisms to adapt to environmental changes. The phenotypic adaptability of a Daphnia galeata clone to temperature rise and salinisation was investigated in this study, by evaluating its halotolerance at two different temperatures, along a short multigenerational acclimation scenario. Daphniids were acclimated to different temperatures (20°C and 25°C) and salinities (0gL(-1) and 1gL(-1), using NaCl as a proxy) in a fully crossed design. The objective was to understand whether acclimation to environmental stress (combinations of temperature and salinity) influenced the response to the latter exposure to these stressors. We hypothesize that acclimation to different temperature×salinity regimes should elicit an acclimation response of daphniids to saline stress or its interaction with temperature. Acute (survival time) and chronic (juvenile growth) halotolerance measures were obtained at discrete timings along the acclimation period (generations F1, F3 and F9). Overall, exposure temperature was the main determinant of the acute and chronic toxicity of NaCl: daphniid sensitivity (measured as the decrease of survival time or juvenile growth) was consistently higher at the highest temperature, irrespective of background conditions. However, this temperature-dependent effect was nullified after nine generations, but only when animals had been acclimated to both stressors (high salinity and high temperature). Such complex interaction scenarios should be taken in consideration in risk assessment practices.

  10. Responses of quinoa (Chenopodium quinoa Willd.) to salinity and temperature regimes

    DEFF Research Database (Denmark)

    Adolf, Verena Isabelle

    Water scarcity, soil salinity and high temperatures are the major causes of yield losses worldwide. The halophytic crop quinoa that originates in the South American Andes, provides very nutritious seeds and can tolerate high levels of soil salinity. It is therefore considered an option to sustain...... crop production in other salt affected areas worldwide. The large genetic variability within the species may allow the selection of varieties for cultivation under various climatic conditions. In the study, intra-species differences of quinoa’s tolerance to salinity in terms of biomass production...... and a number of physiological traits were assessed. The Mediterranean region increasingly suffers from soil salinization, and could therefore benefit from quinoa cultivation. However, highly salt tolerant quinoa cultivars originate in the cool Andean highland. Hence, for a successful production of quinoa...

  11. The influence of temperature and salinity variability on the upper ocean density and mixed layer

    Directory of Open Access Journals (Sweden)

    R. W. Helber

    2010-08-01

    Full Text Available The relative influence of both temperature and salinity on the mixed layer depth (MLD is evaluated using a relationship of binned regressions of MLD on vertical density compensation and isothermal layer depth (ILD from a global set of in situ profile observations. Our approach is inspired by the observations of the difference between the MLD and the sonic layer depth (SLD that evolve seasonally around the global ocean. In this article, we hypothesize that vertical density compensation governs SLD-MLD differences and can be used for mapping the relative influence of temperature and salinity on upper ocean structure. The Turner angle, computed between the surface and 200 m (bulk Turner angle, BTA, serves as a measure of vertical density compensation that quantifies times and areas where either temperature or salinity is destabilizing. For temperature destabilization the ocean exhibits cool/fresh overlying hot/salty water. For salinity destabilization the ocean exhibits hot/salty overlying cool/fresh water. These two classes of density compensation have seasonal variability with different geographical characteristics. Profiles with salinity controlled stable density and destabilizing temperature gradient are found most often at high latitudes. Profiles with temperature controlled stable density and destabilizing salinity gradient are found in the tropics and subtropics of all oceans. Results indicate that about half of the ocean has vertical density compensation that is a necessary condition for SLD-MLD differences. While density compensation is necessary, it is not a sufficient condition for predicting the dependence of MLD on BTA. Density compensation is the dominant factor in MLD variability in heavy river input and subduction regions that cover only ~14% of the ocean.

  12. Effect of temperature, salinity and irradiance on growth and photosynthesis of Ulva prolifera

    Institute of Scientific and Technical Information of China (English)

    XIAO Jie; ZHANG Xiaohong; GAO Chunlei; JIANG Meijie; LI Ruixiang; WANG Zongling; LI Yan; FAN Shiliang; ZHANG Xuelei

    2016-01-01

    Intensive Pyropia aquaculture in the coast of southwestern Yellow Sea and its subsequent waste, including disposed Ulva prolifera, was speculated to be one of the major sources for the large-scale green tide proceeding in the Yellow Sea since 2007. It was, however, unclear how the detached U. prolifera responded and resumed growing after they detached from its original habitat. In this study, we investigated the growth and photosynthetic response of the detached U. prolifera to various temperature, salinity and irradiance in the laboratory. The photosynthetic rate of the detached U. prolifera was significantly higher at moderate temperature levels (14–27°C) and high salinity (26–32), with optimum at 23°C and 32. Both low (<14°C) and highest temperature (40°C), as well as low salinity (8) had adverse effects on the photosynthesis. Compared with the other Ulva species, U. prolifera showed higher saturated irradiance and no significant photoinhibition at high irradiance, indicating the great tolerance of U. prolifera to the high irradiance. The dense branch and complex structure of floating mats could help protect the thalli and reduce photoinhibition in field. Furthermore, temperature exerted a stronger influence on the growth rate of the detached U. prolifera compared to salinity. Overall, the high growth rate of this detached U. prolifera (10.6%–16.7% d–1) at a wide range of temperature (5–32°C) and salinity (14–32) implied its blooming tendency with fluctuated salinity and temperature during floating. The environmental parameters in the southwestern Yellow Sea at the beginning of green tide were coincident with the optimal conditions for the detached U. prolifera.

  13. Effects of Temperature, Salinity and Fish in Structuring the Macroinvertebrate Community in Shallow Lakes: Implications for Effects of Climate Change

    Science.gov (United States)

    Brucet, Sandra; Boix, Dani; Nathansen, Louise W.; Quintana, Xavier D.; Jensen, Elisabeth; Balayla, David; Meerhoff, Mariana; Jeppesen, Erik

    2012-01-01

    Climate warming may lead to changes in the trophic structure and diversity of shallow lakes as a combined effect of increased temperature and salinity and likely increased strength of trophic interactions. We investigated the potential effects of temperature, salinity and fish on the plant-associated macroinvertebrate community by introducing artificial plants in eight comparable shallow brackish lakes located in two climatic regions of contrasting temperature: cold-temperate and Mediterranean. In both regions, lakes covered a salinity gradient from freshwater to oligohaline waters. We undertook day and night-time sampling of macroinvertebrates associated with the artificial plants and fish and free-swimming macroinvertebrate predators within artificial plants and in pelagic areas. Our results showed marked differences in the trophic structure between cold and warm shallow lakes. Plant-associated macroinvertebrates and free-swimming macroinvertebrate predators were more abundant and the communities richer in species in the cold compared to the warm climate, most probably as a result of differences in fish predation pressure. Submerged plants in warm brackish lakes did not seem to counteract the effect of fish predation on macroinvertebrates to the same extent as in temperate freshwater lakes, since small fish were abundant and tended to aggregate within the macrophytes. The richness and abundance of most plant-associated macroinvertebrate taxa decreased with salinity. Despite the lower densities of plant-associated macroinvertebrates in the Mediterranean lakes, periphyton biomass was lower than in cold temperate systems, a fact that was mainly attributed to grazing and disturbance by fish. Our results suggest that, if the current process of warming entails higher chances of shallow lakes becoming warmer and more saline, climatic change may result in a decrease in macroinvertebrate species richness and abundance in shallow lakes. PMID:22393354

  14. Toxin and Growth Responses of the Neurotoxic Dinoflagellate Vulcanodinium rugosum to Varying Temperature and Salinity

    Science.gov (United States)

    Abadie, Eric; Muguet, Alexia; Berteaux, Tom; Chomérat, Nicolas; Hess, Philipp; Roque D’OrbCastel, Emmanuelle; Masseret, Estelle; Laabir, Mohamed

    2016-01-01

    Vulcanodinium rugosum, a recently described species, produces pinnatoxins. The IFR-VRU-01 strain, isolated from a French Mediterranean lagoon in 2010 and identified as the causative dinoflagellate contaminating mussels in the Ingril Lagoon (French Mediterranean) with pinnatoxin-G, was grown in an enriched natural seawater medium. We tested the effect of temperature and salinity on growth, pinnatoxin-G production and chlorophyll a levels of this dinoflagellate. These factors were tested in combinations of five temperatures (15, 20, 25, 30 and 35 °C) and five salinities (20, 25, 30, 35 and 40) at an irradiance of 100 µmol photon m−2 s−1. V. rugosum can grow at temperatures and salinities ranging from 20 °C to 30 °C and 20 to 40, respectively. The optimal combination for growth (0.39 ± 0.11 d−1) was a temperature of 25 °C and a salinity of 40. Results suggest that V. rugosum is euryhaline and thermophile which could explain why this dinoflagellate develops in situ only from June to September. V. rugosum growth rate and pinnatoxin-G production were highest at temperatures ranging between 25 and 30 °C. This suggests that the dinoflagellate may give rise to extensive blooms in the coming decades caused by the climate change-related increases in temperature expected in the Mediterranean coasts. PMID:27164144

  15. Electrochemical behavior of titanium in saline environments: The effects of temperature, pH, and microstructure

    Energy Technology Data Exchange (ETDEWEB)

    VanVliet, K.J.; Wang, Z.F.; Briant, C.L.; Kumar, K.S. [Brown Univ., Providence, RI (United States). Div. of Engineering

    1998-12-31

    This research investigates the effects of temperature, pH, degree of salinity, galvanic coupling, microstructure, and composition on the electrochemical behavior of commercially pure titanium in a saline environment. Essentially, the findings establish that increased temperature, altered microstructure, decreased pH, and decreased purity of titanium all serve to increase the corrosion potential and cathodic reaction rate, thus making the metal more susceptible to hydrogen absorption. Further, the data indicate that galvanic coupling with certain metals such as naval brass and stainless steel can anodically polarize titanium, whereas coupling with metals such as aluminum, HY80 steel, and zinc catholically polarizes titanium, thus promoting hydrogen evolution on the titanium surface.

  16. Effect of concentration and temperature on surface tension of sodium hyaluronate saline solutions.

    Science.gov (United States)

    Ribeiro, Walkiria; Mata, José Luis; Saramago, Benilde

    2007-06-19

    The effect of concentration and temperature on the surface tension of sodium hyaluronate (NaHA) saline solutions was investigated using the technique of the shape of pendant drops. The decay rate of the surface tension with the increase of NaHA concentration was well-described by the empirical Hua-Rosen equation. Adsorption at the air-liquid interface was estimated using the Gibbs equation. The temperature dependence of a dilute solution and a semidilute entangled solution was numerically fitted with a second-order polynomial equation. The surface behavior of the NaHA saline solutions was interpreted in terms of their known viscoelastic properties.

  17. Coastal Paleoclimate: Unraveling Temperature and Salinity History Using Ostracode Shell Chemistry

    Science.gov (United States)

    Dwyer, G. S.; Cronin, T. M.; Vann, C. D.; Kamiya, T.

    2001-12-01

    Long-term records of temperature and salinity of coastal waters are important for understanding coastal environmental change, its linkages to regional, hemispheric or global climate change, and its impact on coastal ecosystems and cultures, yet few reliable, widely applicable temperature and salinity proxies are available for coastal settings. To address this need, we developed magnesium/calcium (Mg/Ca) paleothermometry in calcitic shells of benthic ostracode Loxoconcha, a common genus found in shallow shelf, lagoon, and estuarine systems from tropical to temperate latitudes. Calibration studies, including analysis of field and laboratory-raised specimens as well as ambient water chemistry from a wide range of temperatures and salinties (T=10 to 30 deg. C, S=15 to 40 ppt), confirm a strong Mg/Ca-temperature relationship. We have applied this relation to sediment cores from Chesapeake Bay to reconstruct late Holocene water temperature which, when coupled with benthic ostracode or foraminifer stable oxygen isotopes (\\delta18Ob), permits removal of the temperature effect on \\delta18Ob and the direct calculation of the \\delta18O of the water. This in turn provides an estimate of paleosalinity and regional runoff and precipitation. At salinity below approximately 15 ppt and in regions where coastal geology is dominated by limestone, the Mg/Ca-temperature relation can be complicated due to the influence of runoff on the Mg/Ca ratio of local coastal waters. Such is the case for eastern Florida Bay, where salinity-dependent, runoff-driven changes in water Mg/Ca ratios appear to override the temperature effect on shell Mg/Ca ratios. Multi-decadal to inter-annual variability in ostracode Mg/Ca records from this coastal setting thus primarily reflects salinity fluctuations that appear to be associated with ENSO-driven winter rainfall anomalies.

  18. Behaviour and orcadian rhythm of the fish bathygobius soporator Valenciennes (Gobiidae under the influence of environmental salinity and temperature

    Directory of Open Access Journals (Sweden)

    Edith Fanta

    1997-01-01

    Full Text Available The behavioural patterns and their cireadian rhythms may be adaptive to the peculiar environmental conditions of subtropical brackish waters where Ba-thygobius soporator Valenciennes, 1837 live. Adult fish were caught at the southern Brazilian coast from mangrove rivers and rocky shores in a bay, where temperature and water salinity vary during the day and through the year. Observation on the behaviour of the animals was undertaken in salinity 8.5ppt, 17.0ppt, 25.5ppt and 34.0ppt, each one in temperatures of 18ºC and 28ºC. Temperature and salinity affect the frequency and intensity of some of the behavioural events, more than its pattern or rhythm. Swimming is rare, decreasing along the day and with temperature increase, being even lower at low salinity; aggressiveness is the highest in the morning being not affected by temperature, but by salinity, being higher the higher it is; territory defence decreases along the day and is lower at high temperature and extreme salinities; fish hide more at high temperature and with the decrease of salinity, but this is not rhythmical; a higher proportion of fish rest in vertical position when salinity and temperature are high, increasing slightly at the beginning of the afternoon; respiratory frequency increases with temperature, salinity and in the afternoon; the colour of the fish is mainly light with spots in all hours of the day and in all temperatures and different levels of salinity, but with a tendency of the presence of some dark fish during the morning and some light ones in the afternoon, showing a higher variability of colours at low temperature and extreme salinities. Besides temperature, salinity and light, feeding seems to be one of the determinant factors for the performance of the typical behaviour of B. soporator.

  19. Prospective comparison of chilled versus room temperature saline irrigation in alcohol-assisted photorefractive keratectomy.

    Science.gov (United States)

    Neuffer, M C; Khalifa, Y M; Moshirfar, M; Miffin, M D

    2013-01-01

    Chilled saline is commonly used to irrigate the ocular surface after photorefractive keratectomy (PRK) and is often considered by the patients to be uncomfortable. Room temperature (non-chilled) saline may be a safe and less painful alternative. To compare pain and visual outcomes after irrigating the ocular surface with chilled saline versus room temperature saline in alcohol assisted PRK. In this prospective, single-masked, randomized, contralateral eye study, myopic eyes were treated with PRK. Immediately after laser ablation one eye was irrigated with chilled saline and the other with non-chilled saline. Primary outcomes measured were pain, haze, uncorrected (UCVA) and best-corrected (BCVA) visual acuities, and manifest refraction. Each group comprised of 40 eyes. There was no significant difference in pain between the groups at any point during five days after surgery. At 6 months the mean UCVA was -0.08 logMAR ± .077 [SD] (20/17) and -0.07 ± .074 logMAR (20/17) in the chilled and non-chilled groups respectively (p =.35). Both groups achieved 95% UCVA of 20/20 or better. The manifest refraction spherical equivalent (MRSE) was -0.05 ± 0.21 D and -0.025 ± 0.27 D respectively (p = .79). There were no lines lost of BCVA and no haze observed. Similar outcomes were observed with regard to pain and vision in both groups. The use of room temperature saline irrigation during PRK appears to be safe and effective. © NEPjOPH.

  20. The influence of temperature, pressure, salinity and capillary force on the formation of methane hydrate

    Directory of Open Access Journals (Sweden)

    Zhenhao Duan

    2011-04-01

    Full Text Available We present here a thermodynamic model for predicting multi-phase equilibrium of methane hydrate liquid and vapor phases under conditions of different temperature, pressure, salinity and pore sizes. The model is based on the 1959 van der Waals–Platteeuw model, angle-dependent ab initio intermolecular potentials, the DMW-92 equation of state and Pitzer theory. Comparison with all available experimental data shows that this model can accurately predict the effects of temperature, pressure, salinity and capillary radius on the formation and dissociation of methane hydrate. Online calculations of the p–T conditions for the formation of methane hydrate at given salinities and pore sizes of sediments are available on: www.geochem-model.org/models.htm.

  1. Effects of temperature and salinity on growth and survival of the Pacific red snapper Lutjanusperu (Pisces: Lutjanidae juvenile

    Directory of Open Access Journals (Sweden)

    Sergio Castillo-Vargasmachuca

    2013-11-01

    Full Text Available The present study evaluates the effects of temperature (25 and 30°C and salinity (25, 35 and 45 psu on juvenile growth and survival. All the experiments were carried out under rearing conditions. A total of 270 specimens were used for the experiments. The results showed that more than 86% of the snapper survived at 35 to 45 psu salinity. Significant differences in growth parameters, such as the specific growth rate and weight gain were observed in fish reared at temperatures of 25 and 30°C and salinities of 35 and 45 psu. Increased salinity beyond 45 psu negatively affected growth of the Pacific red snapper used in this trial. The effects of temperature and salinity on growth performance a survival rate indicated that red snapper is an euryhaline species, that may tolerate wide salinity ranges, showing that has a good potential to grow in waters of lower salinity than the sea.

  2. Dependence of CO2-Brine Interfacial Tension on Aquifer Pressure, Temperature and Water Salinity

    Science.gov (United States)

    Bachu, S.; Bennion, B.

    2007-12-01

    Carbon dioxide storage in deep saline aquifers is a climate-change mitigation strategy that has significant potential in the short-to-medium term. The displacement of formation water by CO2 (drainage) and of CO2 by invading aquifer brine (imbibition) depend on the interfacial tension (IFT) of the CO2-brine system. To provide needed data, an extensive laboratory program was conducted for the measurement of the interfacial tension between CO2 and water or brine covering the ranges of 2 to 27 MPa pressure, 20°C to 125°C temperature, and 0 to 334,000 mg/l water salinity. The laboratory experiments were conducted using the pendant drop method combined with the Laplace solution for the profile of the brine drop in the CO2-rich environment. The analysis of the resulting set of 294 IFT measurements reveals that: 1) for conditions of constant temperature and water salinity, IFT decreases steeply with increasing pressure in the range PPc, with an asymptotic trend towards a constant value for high pressures; 2) for the same conditions of constant pressure and temperature, IFT increases with increasing water salinity, reflecting decreasing CO2 solubility in brine as salinity increases; 3) the dependence of IFT on temperature is more complex, depending on the CO2 phase. For TTc, with an asymptotic trend towards a constant value for high temperatures. These results indicate that, in the case of CO2 storage in deep saline aquifers, the formation water displacement by injected CO2 during the injection phase of CO2 storage and the CO2 displacement by invading brine during the CO2 migration phase depend on the in-situ conditions of pressure, temperature and water salinity through the effects that these primary variables have on the IFT between CO2 and aquifer brine. Since the IFT of CO2-brine systems affects relative permeability and capillary pressure, it is essential that the in-situ conditions and their effect of secondary variables are properly taken into account when

  3. Short-term salinity tolerance of northern pike, Esox lucius , fry, related to temperature and size

    DEFF Research Database (Denmark)

    Jacobsen, Lene; Skov, Christian; Koed, Anders

    2007-01-01

    The short-term tolerances of northern pike, Esox lucius L., fry reared in a freshwater hatchery, to salinity were examined in the laboratory. Survival of two size groups of pike fry (mean length 21 +/- 2 mm SD and 37 +/- 4 mm SD) was examined over 72- to 96-h periods at 9-14 ppt salinity in combi......The short-term tolerances of northern pike, Esox lucius L., fry reared in a freshwater hatchery, to salinity were examined in the laboratory. Survival of two size groups of pike fry (mean length 21 +/- 2 mm SD and 37 +/- 4 mm SD) was examined over 72- to 96-h periods at 9-14 ppt salinity...... in combination with temperatures of 10, 14 and 18 degrees C. A parametric survival model found a significant correlation between survival of pike fry and temperature and salinity, respectively. L(C)50 values after 72 h were between 11.2 and 12.2 ppt, being lowest at 10 degrees C. Pike fry did not survive more...... than 13 ppt. Mortality at 12 ppt was significantly faster at 18 degrees C than 10 or 14 degrees C. Moreover, mortality was higher and faster for large than for small pike fry at 12 ppt and 14 degrees C. These results imply that pike raised in fresh water can survive stocking into brackish waters below...

  4. Influence of food concentration, temperature and salinity on the larval development of Balanus amphitrite

    Digital Repository Service at National Institute of Oceanography (India)

    Anil, A.C.; Kurian, J.

    Influence of food concentration (0.5, 1 and 2 x 10 sup(5) cell ml sup(-1) of Skeletonema costatum), temperature (20 and 30 degrees C) and salinity (15, 25 and 35 ppt) on the larval development of Balanus amphitrite (Cirripedia: Thoracica...

  5. The pigment composition of Phaeocystis antarctica (Haptophyceae) under varius conditions of light, temperature, salinity, and iron

    NARCIS (Netherlands)

    van Leeuwe, Maria A.; Visser, Ronald J. W.; Stefels, Jacqueline

    2014-01-01

    The pigment composition of Phaeocystis antarctica was monitored under various conditions of light, temperature, salinity, and iron. 19'-Hexanoyloxyfucoxanthin (Hex-fuco) always constituted the major light-harvesting pigment, with remarkably stable ratios of Hex-fuco-to-chl a under the various

  6. Sulfate reducing processes at extreme salinity and temperature. extending its application window

    NARCIS (Netherlands)

    Vallero, M.V.G.

    2003-01-01

    The characteristics of various sulfate-rich wastewaters, such as temperature, pH and salinity, are determined by the (industrial) process from which they originate, and can be far from the physiological optima of the sulfur cycle microorganisms. The main goal of the research described in this thesis

  7. Effect of temperature, salinity, light and time of dehiscence on seed ...

    African Journals Online (AJOL)

    the effect of temperature, salinity and time of fruit dehiscence on the seed germination and seedling morphology of .... in shape with a mean length of 12 cm and a mean width of10cm. ..... plant either due to absence of rain in the study area or.

  8. Stress tolerance of a subtropical Crassostrea virginica population to the combined effects of temperature and salinity

    Science.gov (United States)

    Heilmayer, Olaf; Digialleonardo, Julian; Qian, Lianfen; Roesijadi, Guritno

    2008-08-01

    The combination of salinity and temperature has synergistic effects on virtually all aspects of the biology of estuarine organisms. Of interest were site-specific characteristics in the response of the eastern oyster, Crassostrea virginica, from the St. Lucie River Estuary to the interactive effects of temperature and salinity. This estuary, one of the largest on the central east coast of Florida, is strongly influenced by anthropogenic modifications due to management needs to control the patterns of freshwater flow in the St. Lucie River watershed. Crassostrea virginica is designated a valued ecosystem component for monitoring the health of this estuary. Our approach used a multidimensional response surface design to study the effects of temperature and salinity on sublethal measures of oyster performance: (1) body condition index as an overall indicator of bioenergetic status and (2) the RNA/DNA ratio as a biochemical indicator of cellular stress. The results showed that there was a greater ability to withstand extreme salinity conditions at lower temperatures. However, there were no site-specific attributes that differentiated the response of the St. Lucie Estuary population from populations along the distribution range. Condition index was a less variable response than the RNA/DNA ratio, and the final models for mean condition index and the RNA/DNA ratios explained 77.3 and 35.8% of the respective variances.

  9. Stress tolerance of a subtropical Crassostrea virginica population to the combined effects of temperature and salinity

    Energy Technology Data Exchange (ETDEWEB)

    Heilmayer, Olaf; DiGialleonardo, Julian J.; Qian, Lianfen; Roesijadi, Guritno

    2008-08-10

    The combination of salinity and temperature has synergistic effects on virtually all aspects of the biology of estuarine organisms. Of interest were site-specific characteristics in the response of the eastern oyster, Crassostrea virginica, from the St. Lucie River Estuary to the interactive effects of temperature and salinity. This estuary, one of the largest on the central east coast of Florida, is strongly influenced by anthropogenic modifications due to management needs to control the patterns of freshwater flow in the St. Lucie River watershed. C. virginica is designated a valued ecosystem component for monitoring the health of this estuary. Our approach used a multidimensional response surface design to study the effects of temperature and salinity on sublethal measures of oyster performance: (1) body condition index as an overall indicator of bioenergetic status and (2) the RNA/DNA ratio as a biochemical indicator of cellular stress. The results showed that there was a greater ability to withstand extreme salinity conditions at lower temperatures. However, there were no site-specific attributes that differentiated the response of the St. Lucie Estuary population from populations along the distribution range. Condition index was a less variable response than the RNA/DNA ratio, and the final models for mean condition index and the RNA:DNA ratios explained 77.3% and 35.8% of the respective variances.

  10. Effects of salinity and water temperature on the ecological performance of Zostera marina

    DEFF Research Database (Denmark)

    Nejrup, Lars Brammer; Pedersen, Morten Foldager

    2008-01-01

    We tested the effects of salinity and water temperature on the ecological performance of eelgrass (Zostera marina L.) in culture-experiments to identify levels that could potentially limit survival and growth and, thus, the spatial distribution of eelgrass in temperate estuaries. The experiments ...

  11. Wave-current interactions in the southern North Sea: The impact on salinity

    Science.gov (United States)

    Schloen, Julia; Stanev, Emil V.; Grashorn, Sebastian

    2017-03-01

    The interplay between wind waves and currents in the coastal zone of the southern North Sea along with the resulting changes in the salinity distribution are quantified using simulations with the unstructured-grid ocean model SCHISM coupled with the wind wave model WWM III. Several sensitivity runs, which are carried out to estimate the individual contributions of different physical mechanisms and forcing, demonstrated that the density gradients in the coastal zone reduce tidal current by 18%, whereas the wind waves enhance the circulation in some cases. The latter happens when along-shore wind speed approaches ∼10 m s-1 resulting in long-shore currents following the western Dutch coast and the German Wadden Sea islands. The wave-induced transport of salt leads to changes in the horizontal salinity distribution. These are most pronounced in front of barrier islands where coherent patterns caused by the coupling between tides, surface drift, and wind waves reveal salinity changes up to 0.5. The weak stratification of salinity in the coastal zone is mostly destroyed by wind waves. Thus, effects created by wind waves tend to substantially modify the estuarine circulation. An explanation of these important processes in the coastal zone has been given based on an analysis of the ratio between significant wave height and tidal range. This control-parameter, which is relatively small under mild weather conditions, can exceed unity under strong wind conditions in the coastal zone, thus mixing due to waves becomes dominant. The effect of fresh water fluxes from subterranean estuaries is relatively small and confined only in the vicinity of corresponding sources.

  12. Temperature effect on high salinity depuration of Vibrio vulnificus and V. parahaemolyticus from the Eastern oyster (Crassostrea virginica).

    Science.gov (United States)

    Larsen, A M; Rikard, F S; Walton, W C; Arias, C R

    2015-01-02

    Vibrio vulnificus (Vv) and Vibrio parahaemolyticus (Vp) are opportunistic human pathogens naturally associated with the Eastern oyster Crassostrea virginica. The abundances of both pathogens in oysters are positively correlated with temperature, thus ingestion of raw oysters during the warm summer months is a risk factor for contracting illness from these bacteria. Current post-harvest processing (PHP) methods for elimination of these pathogens are expensive and kill the oyster, changing their organoleptic properties and making them less appealing to some consumers. High salinity has proven effective in reducing Vv numbers in the wild and our research aims at developing an indoor recirculating system to reduce pathogenic Vibrios while maintaining the taste and texture of live oysters. The goal of this study was to determine the influence of temperature on the efficacy of high salinity depuration. Vv was enumerated as most probable number (MPN) per gram of oyster tissue using the FDA-approved modified cellobiose polymyxin colistin (mCPC) protocol and with an alternative Vibrio specific media CHROMagar™ Vibrio (CaV). CaV was also used to quantify Vp. Oysters were held at 35 psu for 10 days at three temperatures: low (20°C), mid (22.5°C) and high (25°C). There was no difference in MPN/g of Vv between media; however more Vv isolates were obtained from mCPC than CaV. There was no significant effect of temperature on reduction of Vv or Vp throughout depuration but there was a tendency for low temperatures to be less effective than the higher ones. High salinity resulted in a significant decrease in Vv by day 3 and again by day 10, and a decrease in Vp by day 3. Oyster condition indices were maintained throughout depuration and mortality was low (4% across three trials). Overall these results support the use of mCPC for Vv enumeration and demonstrate the promise of high salinity depuration for PHP of the Eastern oyster. The trend for lower temperatures to be less

  13. A new algorithm for microwave radiometer remote sensing of sea surface salinity and temperature

    Institute of Scientific and Technical Information of China (English)

    YIN; Xiaobin; LIU; Yuguang; WANG; Zhenzhan

    2006-01-01

    The microwave radiation of the sea surface, which is denoted by the sea surface brightness temperature, is not only related with sea surface salinity (SSS) and temperature (SST), but also influenced by sea surface wind. The errors of wind detected by satellite sensor have significant influences on the accuracy of SSS and SST retrieval. The effects of sea surface wind on sea surface brightness temperature, i.e. △Th,v, and the relations among △Th,v, wind speed, sea surface temperature, sea surface salinity and incidence angle of observation are investigated. Based on the investigations, a new algorithm depending on the design of a single radiometer with double polarizations and multi-incidence angles is proposed. The algorithm excludes the influence of sea surface wind on SSS and SST retrieval, and provides a new method for remote sensing of SSS and SST.

  14. Different effects of temperature and salinity on permeability reduction by fines migration in Berea sandstone

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Kjøller, Claus; Riis, Jacob Fabricius

    2015-01-01

    change by means of flow through experiments and examined thin sections of samples prior to and after tests. A permeability reduction at 20 degrees C with decreasing salinity was not reversed by restoring the salinity, whereas a permeability reduction due to heating to 80 degrees C was reversible...... by restoring the temperature to 20 degrees C. A reversible permeability increase with increasing flow rate was observed at 80 degrees c but not at 20 degrees C. We observed no difference in the distribution of kaolinite clay minerals in thin section of untested and tested samples. Dissolution of iron bearing...

  15. COMBINED EFFECTS OF TEMPERATURE, IRRADIANCE AND SALINITY ON GROWTH OF DIATOM SKELETONEMA COSTATUM

    Institute of Scientific and Technical Information of China (English)

    颜天; 周名江; 钱培元

    2002-01-01

    3-factor experiment was used to study the combined effects of temperature, irradiance and salinity on the growth of an HAB species diatom Skeletonema costatum (Grey.) Cleve. The results showed that temperature (12, 19, 25, 32℃ ), irradiance ((0.02, 0.08, 0.3, 1.6) × 1016 quanta/(s·cm2) ) and salinity (10, 18, 25, 30, 35) significantly influenced the growth of this species. There were interactive effects between any two of and among all three physical factors on the growth. In the experiment, the most optimal growth condition for S. costatum was temparature of 25℃, salinity of 18 - 35 and irradiance of 1.6 × 1016 quanta/(s·cm2). The results indicated S. costatum could divide at higher rate and were more likely to bloom under high temperature and high illumination from spring to fall. It was able to distribute widely in ocean and estuary due to its adaptation to a wide range of salinities.

  16. Near-surface Observations of Temperature and Salinity from Profiling Floats: The Diurnal Cycle, Precipitation, and Mixing

    Science.gov (United States)

    Anderson, J. E.; Riser, S.

    2012-12-01

    Observations of near-surface temperature and salinity obtained from Argo-type profiling floats enhanced with an auxiliary Surface Temperature and Salinity (STS) CTD are presented. Using the STS unit, high vertical resolution (Price-Weller-Pinkel (PWP) one-dimensional mixed layer model. Additionally, the near-surface heat budget is examined.

  17. Laboratory observations of saline and turbidity currents flowing in U-shaped flume

    Science.gov (United States)

    Stagnaro, M.; Bolla Pittaluga, M.

    2013-12-01

    Saline and turbidity currents belong to the large family of gravity currents. Due to the difficulties to predict and observe these kinds of phenomena, especially turbidity currents, we developed an experimental apparatus able to reproduce these currents in our Marchi Environmental Laboratory (Genova, Italy). The experiments were performed in a large U-shaped flume, 30 m long, characterized by a constant curvature bend (radius of 2.5 m) joining two straight reaches approximately 12 m long. The flume has a rectangular cross section 0.6 m wide and 0.5 m deep. Inside the flume we made a uniform concrete bottom slope (0.005), which proceeds from the inlet section along the first straight track and finishes 3 m after the bend exit. For each experiment we have been able to measure density distribution and velocity profiles along the vertical in different cross section. Density measurements were obtained using two ranks of siphons that sample the currents at different heights. Velocity was acquired with the DOP2000 ultrasound velocimeter; we measured longitudinal component in the straight reach of the flume, and both longitudinal and transversal velocity in the curved reach. We performed 30 experiments by changing the inlet conditions: primary defining the nature of the currents, saline or sediment laden, then varying two of the main parameters governing the currents: the density of the mixture and the flow discharge. The former covered a range between 1003 and 1023 kg/m^3 and the flow discharge ranged between 0.5 to 4.0 l/s. Both of these parameters influence the densimetric Froude Number, and allowed us to reproduce both subcritical and supercritical flow. In each experiment water entrainment from above was negligible hence the current was able to attain a quasi-uniform configuration in the first straight reach, whereby the longitudinal velocity and the thickness of the current were approximately constant. By varying the inlet conditions, it was possible to observe the

  18. Modeling seawater salinity and temperature sensing based on directional coupler assembled by polyimide-coated micro/nanofibers.

    Science.gov (United States)

    Wang, Shanshan; Liao, Yipeng; Yang, Hongjuan; Wang, Xin; Wang, Jing

    2015-12-01

    The salinity and temperature of seawater are important parameters in oceanography. Based on the directional coupler assembled by polyimide-coated micro/nanofibers, optical sensors with high sensitivity for simultaneous salinity and temperature sensing in seawater are proposed. Dependences of sensitivities on wavelength, salinity, and temperature are investigated theoretically, with which performances of such sensor under general sea conditions can be evaluated. Results show that salinity and temperature sensitivities can reach levels of nm/‰ and nm/°C, which are much higher than those of fiber Bragg gratings, knot resonators, and photonic crystal fibers. Other considerations for system design such as the length of the coupling area, the diameter difference between two fibers, and the thickness of polyimide coatings are also discussed. Sensors proposed here suggest a simple approach to realize high-sensitivity micro/nanofiber optical sensing of salinity and temperature in seawater simultaneously and may find applications in developing miniature sensors used in seawater.

  19. Detailed temperature-salinity distribution in the Northeast Atlantic from ship and Argo vertical casts

    Science.gov (United States)

    Bashmachnikov, I.; Neves, F.; Nascimento, A.; Medeiros, J.; Ambar, I.; Dias, J.; Carton, X.

    2014-06-01

    The present study defines new interpolation functions for hydrological data. These functions are applied to generate climatological maps of temperature-salinity distribution with 25 m depth interval and 30 km space interval (MEDTRANS data-set). The data underwent a rigorous data quality control, having passed several filtering procedures. The gridding was done on neutral density surfaces, which allows better representation of the relative intensity of thermohaline fronts for the same gridding radius. The gridding was done using multi-pass Barnes' Optimum Interpolation procedure with spatially variable size of the gridding window. The shape of the window accounted for topographic influence: the dominant along-slope direction of water mass transport. One of the new features was the use of a local ratio of topographic to planetary β-effects to define the shape of the window as a function of the relative importance of the topographic influence. The N/f ratio was used for simulation of the baroclinic decrease of the topographic influence on water mass transport with the distance from the bottom. The gridded fields are available at the web-site of the Center of Oceanography of the University of Lisbon (http://co.fc.ul.pt/en/data). The new MEDTRANS climatology gives more details to the distribution of water characteristics in the Subtropical Northeast Atlantic, in particular near the Iberian Peninsula. The geostrophic currents relative to the 1900 m reference level demonstrate the local circulation features, in good correspondence to the theory and to previous studies: the acceleration in the meanders of the Azores current; the cyclonic gyre in the Gulf of Cadiz; the splitting and separation of the Mediterranean Water outflow from the continental slope near the Gorringe and the Galicia banks. Those features are not reproduced by the alternative climatologies. Seasonal climatologies, computed for the warm (May-October) and cold (November-April) seasons, revealed stronger

  20. Synechococcus sp. strain PCC 7002 transcriptome: acclimation to temperature, salinity, oxidative stress and mixotrophic growth conditions

    Directory of Open Access Journals (Sweden)

    Marcus eLudwig

    2012-10-01

    Full Text Available Synechococcus sp. strain PCC 7002 is a unicellular, euryhaline cyanobacterium. It is a model organism for studies of cyanobacterial metabolism and has great potential for biotechnological applications. It exhibits an exceptional tolerance of high light irradiation and shows very rapid growth. The habitats from which this and closely related strains were isolated are subject to changes in several environmental factors, including light, nutrient supply, temperature, and salinity. In this study global transcriptome profiling via RNAseq has been used to perform a comparative and integrated study of global changes in cells grown at different temperatures, at different salinities and under mixotrophic conditions, when a metabolizable organic carbon source was present. Furthermore, the transcriptomes were investigated for cells that were subjected to a heat shock and that were exposed to oxidative stress. Lower growth temperatures caused relatively minor changes of the transcriptome; the most prominent changes affected fatty acid desaturases. A heat shock caused severe changes of the transcriptome pattern; transcripts for genes associated with major metabolic pathways declined and those for different chaperones increased dramatically. Oxidative stress, however, left the transcript pattern almost unaffected. When grown at high salinity, Synechococcus sp. PCC 7002 had increased expression of genes involved in compatible solute biosynthesis and showed increased mRNA levels for several genes involved in electron transport. Transcripts of two adjacent genes dramatically increased upon growth at high salinity; the respective proteins are putatively involved in coping with oxidative stress and in triggering ion channels. Only minor changes were observed when cells were grown at low salinity or when the growth medium was supplemented with glycerol. However, the transcriptome data suggest that cells must acclimate to excess reducing equivalents when a reduced C

  1. Variable-Temperature Critical-Current Measurements

    Energy Technology Data Exchange (ETDEWEB)

    L. F. Goodrich; T. C. Stauffer

    2009-05-19

    This is the final report of a three year contract that covered 09/19/2005 to 07/14/2008. We requested and received a no cost time extension for the third year, 07/15/2007 to 07/14/2008, to allow DoE to send us funds if they became available during that year. It turned out that we did not receive any funding for the third year. The following paper covers our variable-temperature critical-current measurements. We made transport critical-current (Ic) measurements on commercial multifilamentary Nb3Sn strands at temperatures (T) from 4 to 17 K and magnetic fields (H) from 0 to 14 T. One of the unique features of our measurements is that we can cover a wide range of critical currents from less than 0.1 A to over 700 A.

  2. Eutrophication induced CO₂-acidification of subsurface coastal waters: interactive effects of temperature, salinity, and atmospheric PCO₂.

    Science.gov (United States)

    Sunda, William G; Cai, Wei-Jun

    2012-10-02

    Increasing atmospheric carbon dioxide (CO(2)) is raising seawater CO(2) concentrations and thereby acidifying ocean water. But a second environmental problem, eutrophication, is also causing large CO(2) inputs into coastal waters. This occurs because anthropogenic inputs of nutrients have fueled massive algal blooms, which deplete bottom waters of oxygen (O(2)) and release CO(2) when the organic matter from these blooms is respired by bacteria. On the basis of a biogeochemical model, these CO(2) inputs are predicted to decrease current pH values by 0.25 to 1.1 units, effects that increased with decreasing temperature and salinity. Our model predictions agreed well with pH data from hypoxic zones in the northern Gulf of Mexico and Baltic Sea, two eutrophic coastal systems with large temperature and salinity differences. The modeled and measured decreases in pH are well within the range shown to adversely impact marine fauna. Model calculations show that the acidification from respiratory CO(2) inputs interacts in a complex fashion with that from increasing atmospheric CO(2) and that these pH effects can be more than additive in seawater at intermediate to higher temperatures. These interactions have important biological implications in a future world with increasing atmospheric CO(2), increasing anthropogenic inputs of nutrients, and rising temperatures from CO(2)-linked global warming.

  3. Salinity and Temperature Tolerance of the Nemertean Worm Carcinonemertes errans, an Egg Predator of the Dungeness Crab.

    Science.gov (United States)

    Dunn, Paul H; Young, Craig M

    2015-04-01

    Estuaries can be harsh habitats for the marine animals that enter them, but they may also provide these species with sub-saline refuges from their parasites. The nemertean egg predator Carcinonemertes errans is known to occur less frequently and in smaller numbers on its host, the Dungeness crab Metacarcinus magister, when the hosts are found within estuaries. We examined the temperature and salinity tolerances of C. errans to determine if this observed distribution represents a true salinity refuge. We monitored the survival of juvenile and larval worms exposed to ecologically relevant salinities (5-30) and temperatures (8-20 °C) over the course of several days under laboratory conditions. Juvenile worms were unaffected by the experimental temperature levels and exhibited robustness to salinity treatments 25 and 30. However, significant mortality was seen at salinity treatments 20 and below. Larvae were less tolerant than juveniles to lowered salinity and were also somewhat more susceptible to the higher temperatures tested. Given that the Dungeness crab can tolerate forays into mesohaline (salinity 5-18) waters for several days at a time, our findings suggest that salinity gradients play an important role in creating a parasite refuge for this species within the estuaries of the Pacific Northwest.

  4. Growth response and toxin concentration of cultured Pyrodinium bahamense var. compressum to varying salinity and temperature conditions.

    Science.gov (United States)

    Gedaria, Alice Ilaya; Luckas, Bernd; Reinhardt, Katrin; Azanza, Rhodora V

    2007-09-15

    The growth and toxin production of a Philippine Pyrodinium bahamense isolate in nutrient replete batch cultures were investigated under conditions affected by varying salinity, temperature and combined effects of salinity and temperature. Early exponential growth stage was reached after 7 days with a cell division rate of 0.26 div day(-1). The toxin content reached a peak of 298 fmol cell-1 at mid exponential phase and rapidly declined to 54 fmol cell-1 as it approached the death phase. Only three sets of toxins composed of STX, dcSTX and B1 were detected in which STX made up to 85-98 mol%toxincell-1. P. bahamense was able to grow in salinities and temperatures ranging from 26 per thousand to 36 per thousand and 23 to 36 degrees C, respectively. The optimum growth under varying salinity and temperature conditions was observed at 36 per thousand and 25 degrees C. Toxin content reached a peak of 376 fmol cell-1 at 25 degrees C and was lower (80-116 fmol cell-1) at higher temperatures (32-35 degrees C). Combined effects of salinity and temperature showed that P. bahamense was not able to grow at low salinity and temperature (i.e. below 26 per thousand-28 degrees C). Optimum growth was observed in higher salinities at all temperature conditions.

  5. Current direction, temperature, zooplankton, phytoplankton, and other data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 15 July 1980 - 20 March 1981 (NODC Accession 8100610)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, salinity, and other data were collected using moored current meter casts in the Gulf of Mexico from July 15, 1980 to March 20, 1981....

  6. Current direction, temperature, and other data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 15 May 1979 - 22 March 1980 (NODC Accession 8000457)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, current direction, and other data were collected using moored current meter casts from the EXCELLENCE in the Gulf of Mexico from May 15, 1979...

  7. Current direction, temperature, and other data from moored current meter casts and other instruments in the Gulf of Mexico during the Brine Disposal project, 14 September 1977 - 20 April 1981 (NODC Accession 8100585)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, salinity, and other data were collected using moored current meter casts and other instruments in the Gulf of Mexico from September...

  8. A new atlas of temperature and salinity for the North Indian Ocean

    Indian Academy of Sciences (India)

    A Chatterjee; D Shankar; S S C Shenoi; G V Reddy; G S Michael; M Ravichandran; V V Gopalkrishna; E P Rama Rao; T V S Udaya Bhaskar; V N Sanjeevan

    2012-06-01

    The most used temperature and salinity climatology for the world ocean, including the Indian Ocean, is the World Ocean Atlas (WOA) (Antonov et al 2006, 2010; Locarnini et al 2006, 2010) because of the vast amount of data used in its preparation. The WOA climatology does not, however, include all the available hydrographic data from the Indian Exclusive Economic Zone (EEZ), leading to the potential for improvement if the data from this region are included to prepare a new climatology. We use all the data that went into the preparation of the WOA (Antonov et al 2010; Locarnini et al 2010), but add considerable data from Indian sources, to prepare new annual, seasonal, and monthly climatologies of temperature and salinity for the Indian Ocean. The addition of data improves the climatology considerably in the Indian EEZ, the differences between the new North Indian Ocean Atlas (NIOA) and WOA being most significant in the Bay of Bengal, where the patchiness seen in WOA, an artifact of the sparsity of data, was eliminated in NIOA. The significance of the new climatology is that it presents a more stable climatological value for the temperature and salinity fields in the Indian EEZ.

  9. High-temperature superconducting current leads

    Science.gov (United States)

    Hull, J. R.

    1992-07-01

    The use of high-temperature superconductors (HTSs) for current leads to deliver power to devices at liquid helium temperature is near commercial realization. The use of HTSs in this application has the potential to reduce refrigeration requirements and helium boiloff to values significantly lower than the theoretical best achievable with conventional leads. Considerable advantage is achieved by operating these leads with an intermediate temperature heat sink. The HTS part of the lead can be made from pressed and sintered powder. Powder-in-tube fabrication is also possible, however, the normal metal part of the lead acts as a thermal short and cannot provide much stabilization without increasing the refrigeration required. Lead stability favors designs with low current density. Such leads can be manufactured with today's technology, and lower refrigeration results from the same allowable burnout time. Higher current densities result in lower boiloff for the same lead length, but bumout times can be very short. In comparing experiment to theory, the density of helium vapor needs to be accounted for in calculating the expected boiloff. For very low-loss leads, two-dimensional heat transfer and the state of the dewar near the leads may play a dominant role in lead performance.

  10. Responses of quinoa (Chenopodium quinoa Willd.) to salinity and temperature regimes

    DEFF Research Database (Denmark)

    Adolf, Verena Isabelle

    and a number of physiological traits were assessed. The Mediterranean region increasingly suffers from soil salinization, and could therefore benefit from quinoa cultivation. However, highly salt tolerant quinoa cultivars originate in the cool Andean highland. Hence, for a successful production of quinoa...... on salt affected soils in the Mediterranean region, it is necessary to evaluate whether these cultivars are also able to thrive under warmer temperatures. Temperatures of the Bolivian highland and Morocco were simulated in climate chambers to evaluate the performance of a very salt tolerant Bolivian...

  11. Spatial and environmental components of evolutionary change: interactive effects of salinity and temperature on Fucus vesiculosus as an example

    Science.gov (United States)

    Russell, G.

    1987-09-01

    Intertidal algae experience aerial temperatures as well as those of ambient seawater and, during their periods of emergence, are subject to considerable variation in salinity. The eastern Atlantic distribution of Fucus vesiculosus L. (Phaeophyta) lies within the 5° and 20° August isotherms. Experiments indicate that this plant can survive temperatures above and below these at normal salinity (34‰). However, at extreme temperatures it is evidently much more susceptible to saline changes than at those of the limiting isotherms. Thus the temperature limits for surviving acute saline change appear to give a better biogeographical fit than temperature alone. Nevertheless, the presence of F. vesiculosus in estuaries at or near both geographical limits is inconsistent with the experimental results obtained from British plants. Some population divergence may therefore have occurred.

  12. Temperature-salinity distribution in the northeastern Atlantic from ship and Argo vertical casts

    Science.gov (United States)

    Bashmachnikov, I.; Neves, F.; Nascimento, Â.; Medeiros, J.; Ambar, I.; Dias, J.; Carton, X.

    2015-03-01

    The present study defines new interpolation functions for hydrological data. These functions are applied to generate climatological maps of temperature-salinity distribution with a 25 m depth interval and a 30 km space interval (MEDTRANS data set). The data undergo rigorous initial data quality control, having passed several filtering procedures. The gridding is done on neutral density surfaces, which allows better representation of thermohaline fronts for the same gridding radius. The multi-pass Barnes optimum interpolation procedure with spatially variable size of the gridding window is used. The shape of the window accounts for the dominant along-isobath direction of water mass transport over steeply sloping topography. A local ratio of topographic to planetary β-effects is used to define the shape of the window as a function of the relative importance of the topographic influence. The N/f ratio is applied to account for the baroclinic compensation decay of the topographic influence on water mass transport with the distance from the bottom. The gridded fields are available at the website of the Centre of Oceanography of the University of Lisbon (http://co.fc.ul.pt/en/data). The MEDTRANS climatology gives more details of the distribution of water characteristics in the subtropical northeastern Atlantic than other alternative climatologies and is able to reproduce a number of dynamic features described in the literature: the acceleration in the meanders of the Azores current; the cyclonic gyre in the Gulf of Cadiz; and the splitting and separation of the Mediterranean Water (MW) outflow in two veins near the Gorringe and Galicia banks. Seasonal climatologies, computed for the warm (May-October) and cold (November-April) seasons, reveal stronger zonal extension of the upper ocean patterns during the warm season, as compared to the cold one.

  13. New equations for density, entropy, heat capacity, and potential temperature of a saline thermal fluid

    Science.gov (United States)

    Sun, Hongbing; Feistel, Rainer; Koch, Manfred; Markoe, Andrew

    2008-10-01

    A set of fitted polynomial equations for calculating the physical variables density, entropy, heat capacity and potential temperature of a thermal saline fluid for a temperature range of 0-374 °C, pressure range of 0.1-100 MPa and absolute salinity range of 0-40 g/kg is established. The freshwater components of the equations are extracted from the recently released tabulated data of freshwater properties of Wagner and Pruß [2002. The IAPWS formulation 1995 for the thermodynamic properties of ordinary water substance for general and scientific use. Journal of Physical and Chemical Reference Data 31, 387-535]. The salt water component of the equation is based on the near-linear relationship between density, salinity and specific heat capacity and is extracted from the data sets of Feistel [2003. A new extended Gibbs thermodynamic potential of seawater. Progress in Oceanography 58, 43-114], Bromley et al. [1970. Heat capacities and enthalpies of sea salt solutions to 200 °C. Journal of Chemical and Engineering Data 15, 246-253] and Grunberg [1970. Properties of sea water concentrates. In: Third International Symposium on Fresh Water from the Sea, vol. 1, pp. 31-39] in a temperature range 0-200 °C, practical salinity range 0-40, and varying pressure and is also calibrated by the data set of Millero et al. [1981. Summary of data treatment for the international high pressure equation of state for seawater. UNESCO Technical Papers in Marine Science 38, 99-192]. The freshwater and salt water components are combined to establish a workable multi-polynomial equation, whose coefficients were computed through standard linear regression analysis. The results obtained in this way for density, entropy and potential temperature are comparable with those of existing models, except that our new equations cover a wider temperature—(0-374 °C) than the traditional (0-40 °C) temperature range. One can apply these newly established equations to the calculation of in-situ or

  14. Competition Among Dinoflagellate Alexandrium Tamarense, Raphidophyte Heterosigma Carterae and Diatom Skeletonema Costatum under Combinations of Two Temperatures and Five Salinities

    Institute of Scientific and Technical Information of China (English)

    颜天; 周名江; 钱培元

    2003-01-01

    Competition among HAB (Harmful Algal Bloom) species Dinoflagellate Alexandrium tamarense, Raphidophyte Heterosigma carterae, and Diatom Skeletonema costatum was studied in the laboratory. Experiments with these three major HAB species under combinations of different salinities (10, 18, 25, 30, 35) and temperatures (19℃, 25℃) were carried out. The results showed that S. costatum successfully competed with the other two species at salinities of 18, 25,30, and 35 at temperatures of 19℃ and 25℃. However, H. carterae showed its advantage at low salinity of 10 and became the single dominant species at salinity 10 and 25℃. A. tamarense could not compete successfully with the other two species especially at low salinities. However, it could remain at low density in the presence of higher densities of other algae.

  15. NODC Standard Product: International ocean atlas Volume 4 - Atlas of temperature / salinity frequency distributions (2 disc set) (NODC Accession 0101473)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Atlas presents more than 80,000 plots of the empirical frequency distributions of temperature and salinity for each 5-degree square area of the North Atlantic...

  16. NODC Standard Product: Experimental Compact Disk NODC-01 Pacific Ocean Temperature-Salinity Profiles (1900-1988) (NODC Accession 0086259)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanographic Data Center (NODC) created a compact disk containing over 1.3 million temperature-depth and salinity-depth profiles taken in the Pacific...

  17. Oceanographic profile temperature and salinity measurements collected using bottle from the LITKE in the Arctic in 1948 (NODC Accession 0001088)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity and other profile data digitized at NODC on 05/02/03, received by Igor Smolyar from Matishov, G., A. Zuyev, V. Golubev, N. Adrov, S. Timofeev,...

  18. Influence of Water Temperature and Salinity on PH During Dry Season in Lower Dong Nai River System, Vietnam

    Directory of Open Access Journals (Sweden)

    Dung Dang Quoc

    2015-12-01

    Full Text Available This paper uses the gvSIG 2.2.0 software, IDW interpolation method, river and stream network data, and 36 sampling sites to build the maps of three monitored parameters such as pH, water temperature, and salinity in the Lower Dong Nai River system (2009-2010 in dry season. Based on an analysis of these maps and statistical assessment by using the R software, the correlations between pH, temperature, and salinity are clarified. The results show that the pH and temperature values have a tendency to decrease, whereas the salinity tends to increase annually. The pH value has good and significant correlations with the water temperature and salinity in both simple and multiple linear regression models. The results aim to provide a scientific reference for further research on the water environment in this area.

  19. Oceanographic profile temperature and salinity measurements collected using bottle from the Zarnitsa in the Barents Sea (NODC Accession 0002235)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profile data from the SCIENTIFIC ICHTIOLOGICAL INSTITUTE OF LENINGRAD (RUSSIA), digitized from "Bulletin of the Institute of Ichthyology,...

  20. Growth and proximate composition of the Chaetoceros calcitrans f. pumilus under different temperature, salinity and carbon dioxide levels

    Digital Repository Service at National Institute of Oceanography (India)

    Raghavan, G.; Haridevi, C.K.; Gopinathan, C.P.

    ,growth,compo- sition, temperature, salinity, carbon dioxide, live feed Introduction Microalgaearethemajorfoodsourceformanyaqua- tic organisms and the main live feed component in marine hatchery operations because they serve as a natural resource for polyunsaturated...

  1. Tomato Leaf Photosynthetic Responses to Humidity and Temperature Under Salinity and Water Deficit

    Institute of Scientific and Technical Information of China (English)

    H.L.XU; L.GAUTHIER; 等

    1999-01-01

    Greenhouse tomato plants(Lycopersicon esculentum Mill cv.Capello)were grown on peat-based substrate and treated with high(4.5mS cm-1) and low (2.3mS cm-1)nutrient solution electric conductivity (EC) under high and low substrate water contents.Four weeks after the beginning of the treatments,photosynthesis(PN) was measured under different humidity and temperatures to examine the interactive effects with rhizosphere salinity and water deficit.A rectangular hyperboilc model fitted the light-photosynthesis curve.Photosynthetic capacity(PC)was decreased but quantum yield(YQ) was increased by rhizosphere salinity caused by high EC.PN was decreased by low humidity only in high EC-and/or water-stressed plants.Under high photosynthetic photon flux(PPF),low humidity induced PC decline in water-stressed plants and PN oscillation in high-EC-treated plants.PN increased steadily as the leaf temperature changed from 18℃to 23℃ and then decreased steadily from 23℃to 38℃,At 34℃,PN decreased significantly in waterstressed plants.Dark respiration (RD) increased in an exponential manner as the leaf temperature changed from 18℃ to 38℃ to an extent about ten times higher under38℃ than under 18℃,Our data suggested that PN decrease under high temperature was attributed ,at least in part,to the increased RD,RD in high EC-and/or water-stressed plants was higher than that in the plants of control under lower temperature but lower than that in the plants of control under high temperature,The analysis of stomatal and mesophyll conductance showed that low humidity effect was mainly through stomatal rsponse while temperature effect was mainly through biochemical functions.The result showed that environmental stresses affected PN in an additive or synergistic manner.

  2. Current trends in high temperature design

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, D.L. (Illinois Univ., Urbana, IL (United States). Dept. of Mechanical Engineering)

    1992-01-01

    A review of high temperature design guidelines has been carried out in preparation for designing a solar storage module for the Freedom Spacelab. Three major guidelines, N47, R5 and RCC-MR form the basis of the survey. The main issues with current, mature design in the power industry appear to be adequately covered by these guidelines. A significant finding is that long established models of material damage have survived the test of time very well. A new design regime referred to as Very High Temperature Design (VHTD) is identified. The characteristics of this regime are changing material properties which require some changes in philosophy in drafting of future codes, particularly in regard to definitions of yield strengths and other design allowables. Finally, there is some discussion of the more general use of the stress/strain plane, e.g. isochronous curves, for representation of very complex material constitutive behaviour. A concept called the 'Relaxation Locus', which summarizes essential local constrained component behavior, is introduced and its application to high temperature design problems is discussed briefly. (author).

  3. Coral record of southeast Indian Ocean SST, SSH and salinity and their modulation by ENSO and the Western Pacific temperature gradient

    Science.gov (United States)

    Zinke, Jens; Hoell, Andrew; Lough, Janice M.; Feng, Ming; McCulloch, Malcolm T.

    2016-04-01

    Variability of southeastern Indian Ocean (SEIO) sea surface temperatures (SST), sea surface height (SSH) and salinities off Western Australia is a footprint of interannual and decadal climate variations in the tropical Indo-Pacific. La Niña events often result in a strengthened Leeuwin Current, high coastal sea levels, low salinities and unusually warm SSTs, now termed Ningaloo Niño events. The long-term teleconnections of the southeastern Indian Ocean (SEIO) with ENSO and the West Pacific Warm Pool are poorly understood. Here we demonstrate the role of Indo-Pacific coupling in modulating SST, SSH and salinity in the poorly studied SEIO, through a robust 215 year (1795-2010) geochemical coral proxy sea surface temperature (SST), SSH and salinity record. We show that higher SST and SSH accompanied by lower salinities in the SEIO are linked to the behaviour of ENSO and the Western Pacific Warm Pool on decadal to centennial timescales, and are most pronounced when an anomalously strong zonal SST gradient between the western and central Pacific co-occurs with strong La Niña's. Better understanding of the interplay between the zonal SST gradient in the western Pacific, ENSO phase and intrinsic Indian Ocean variability is expected to improve our ability to better predict unusual marine heat waves, sea level surges and important consequences for marine socio-ecological systems in the Future.

  4. Linear and nonlinear effects of temperature and precipitation on ecosystem properties in tidal saline wetlands

    Science.gov (United States)

    Feher, Laura C.; Osland, Michael J.; Griffith, Kereen T.; Grace, James B.; Howard, Rebecca J.; Stagg, Camille L.; Enwright, Nicholas M.; Krauss, Ken W.; Gabler, Christopher A.; Day, Richard H.; Rogers, Kerrylee

    2017-01-01

    Climate greatly influences the structure and functioning of tidal saline wetland ecosystems. However, there is a need to better quantify the effects of climatic drivers on ecosystem properties, particularly near climate-sensitive ecological transition zones. Here, we used climate- and literature-derived ecological data from tidal saline wetlands to test hypotheses regarding the influence of climatic drivers (i.e., temperature and precipitation regimes) on the following six ecosystem properties: canopy height, biomass, productivity, decomposition, soil carbon density, and soil carbon accumulation. Our analyses quantify and elucidate linear and nonlinear effects of climatic drivers. We quantified positive linear relationships between temperature and above-ground productivity and strong positive nonlinear (sigmoidal) relationships between (1) temperature and above-ground biomass and canopy height and (2) precipitation and canopy height. Near temperature-controlled mangrove range limits, small changes in temperature are expected to trigger comparatively large changes in biomass and canopy height, as mangrove forests grow, expand, and, in some cases, replace salt marshes. However, within these same transition zones, temperature-induced changes in productivity are expected to be comparatively small. Interestingly, despite the significant above-ground height, biomass, and productivity relationships across the tropical–temperate mangrove–marsh transition zone, the relationships between temperature and soil carbon density or soil carbon accumulation were not significant. Our literature review identifies several ecosystem properties and many regions of the world for which there are insufficient data to fully evaluate the influence of climatic drivers, and the identified data gaps can be used by scientists to guide future research. Our analyses indicate that near precipitation-controlled transition zones, small changes in precipitation are expected to trigger

  5. [Dynamics of seasonal plant growth in halophytic meadows taking into account the temperature factor and soil salinity level].

    Science.gov (United States)

    Pis'man, T I; Slosar', N A

    2012-01-01

    A mathematical model has been constructed to describe the growth dynamics of various plant communities of halophytic meadows depending on the temperature factor and degree of soil salinity. Field investigation of the yields of halophytic meadow plant communities were performed in the coastal area of Kurinka Lake in the Altaiskii district of the Republic of Khakasia in 2004 and 2006. The results of field investigations and model studies show that there is a correlation between plant growth and air temperature for plant communities growing on soils with the lowest and medium salinity levels. It was proven in model studies that for the plant communities that grow on highly saline (3.58%) soils, not only air temperature but also the salinity level of the soil should be taken into account.

  6. Osmoregulatory capacity of the shrimp Litopenaeus vannamei at different temperatures and salinities, and optimal culture environment

    Directory of Open Access Journals (Sweden)

    L. Fernando Bückle

    2006-09-01

    Full Text Available Osmoregulation in Litopenaeus vannamei was studied in a factorial experiment at four temperatures (20, 24, 28 and 32 °C and six salinities (10, 16, 22, 28, 34 and 40 ‰. The isosmotic related points for 20, 24, 28, and 32 °C were 754, 711, 822, and 763 mmol/kg, respectively. This species hyperregulates between at salinities of 10 and 20 ‰ and hyporegulates between 20 and 40 ‰. The isosmotic point in L. vannamei exposed to constant salinities changed in relation to temperature from 717 to 823 mmol/kg. For these experimental conditions, the T-S combination of 32 °C and 28 ‰ produced the best growth. Rev. Biol. Trop. 54 (3: 745-753. Epub 2006 Sept. 29.La respuesta osmorreguladora de Litopenaeus vannamei se estudió en un experimento factorial con cuatro temperaturas (20, 24, 28 y 32 ºC y seis salinidades (10, 16, 22, 28, 34 y 40 ‰. Los puntos isosmóticos relacionados para 20, 24, 28, y 32 ºC fueron 754, 711, 822, y 763 mmol/kg, respectivamente. Esta especie hiperregula dentro del intervalo de 10 y 20 ‰ e hiporegula entre 20 y 40 ‰. El punto isosmótico de L. vannamei expuesto a salinidades constantes cambia en relación a la temperatura desde 717 a 823 mmol/kg. Para estas condiciones experimentales, la combinación T-S de 32 ºC y 28 ‰ produjo el mejor crecimiento.

  7. High resolution simulations of down-slope turbidity currents into stratified saline ambient

    Science.gov (United States)

    Ouillon, Raphael; Radhakrishnan, Senthil; Meiburg, Eckart; Sutherland, Bruce

    2016-11-01

    In this work we explore the properties of turbidity currents moving down a slope into a stratified saline ambient through highly resolved 3D Navier-Stokes simulations. Turbidity events are difficult to measure and to replicate experimentally for a wide range of parameters, but they play a key role in ocean, lake or river sediment transport. Our objectives are to improve on previous numerical studies, obtain quantitative data in a more controlled environment than current experimental set-ups, and combine results with analytical arguments to build physics-based scaling laws. We validate our results and propose a simple scaling law to predict the velocity of the front down a slope for any stratification. We also compute a time and space dependent entrainment of ambient fluid and highlight its strong variability. We then introduce a predictable scaling law for the intrusion depth that does not depend on an averaged entrainment and uses it as a verification tool instead. Finally, we show that the ratio of Stokes losses in the local flow around individual particles to dissipative losses of the large scale flow determines the ability of the flow to convert potential energy into kinetic energy. For different parameters, either mechanism can dominate the dynamics of the flow.

  8. The CORA dataset: validation and diagnostics of in-situ ocean temperature and salinity measurements

    Directory of Open Access Journals (Sweden)

    C. Cabanes

    2013-01-01

    Full Text Available The French program Coriolis, as part of the French operational oceanographic system, produces the COriolis dataset for Re-Analysis (CORA on a yearly basis. This dataset contains in-situ temperature and salinity profiles from different data types. The latest release CORA3 covers the period 1990 to 2010. Several tests have been developed to ensure a homogeneous quality control of the dataset and to meet the requirements of the physical ocean reanalysis activities (assimilation and validation. Improved tests include some simple tests based on comparison with climatology and a model background check based on a global ocean reanalysis. Visual quality control is performed on all suspicious temperature and salinity profiles identified by the tests, and quality flags are modified in the dataset if necessary. In addition, improved diagnostic tools have been developed – including global ocean indicators – which give information on the quality of the CORA3 dataset and its potential applications. CORA3 is available on request through the MyOcean Service Desk (http://www.myocean.eu/.

  9. The effect of interpolation methods in temperature and salinity trends in the Western Mediterranean

    Directory of Open Access Journals (Sweden)

    M. VARGAS-YANEZ

    2012-04-01

    Full Text Available Temperature and salinity data in the historical record are scarce and unevenly distributed in space and time and the estimation of linear trends is sensitive to different factors. In the case of the Western Mediterranean, previous works have studied the sensitivity of these trends to the use of bathythermograph data, the averaging methods or the way in which gaps in time series are dealt with. In this work, a new factor is analysed: the effect of data interpolation. Temperature and salinity time series are generated averaging existing data over certain geographical areas and also by means of interpolation. Linear trends from both types of time series are compared. There are some differences between both estimations for some layers and geographical areas, while in other cases the results are consistent. Those results which do not depend on the use of interpolated or non-interpolated data, neither are influenced by data analysis methods can be considered as robust ones. Those results influenced by the interpolation process or the factors analysed in previous sensitivity tests are not considered as robust results.

  10. The CORA dataset: validation and diagnostics of ocean temperature and salinity in situ measurements

    Science.gov (United States)

    Cabanes, C.; Grouazel, A.; von Schuckmann, K.; Hamon, M.; Turpin, V.; Coatanoan, C.; Guinehut, S.; Boone, C.; Ferry, N.; Reverdin, G.; Pouliquen, S.; Le Traon, P.-Y.

    2012-03-01

    The French program Coriolis as part of the French oceanographic operational system produces the COriolis dataset for Re-Analysis (CORA) on a yearly basis which is based on temperature and salinity measurements on observed levels from different data types. The latest release of CORA covers the period 1990 to 2010. To qualify this dataset, several tests have been developed to improve in a homogeneous way the quality of the raw dataset and to fit the level required by the physical ocean re-analysis activities (assimilation and validation). These include some simple tests, climatological tests and a model background check based on a global ocean reanalysis. Visual quality control (QC) is performed on all suspicious temperature (T) and salinity (S) profiles identified by the tests and quality flags are modified in the dataset if necessary. In addition, improved diagnostic tools were developed - including global ocean indicators - which give information on the potential and quality of the CORA dataset for all applications. This Coriolis product is available on request through the MyOcean Service Desk (http://www.myocean.eu/).

  11. The CORA dataset: validation and diagnostics of in-situ ocean temperature and salinity measurements

    Science.gov (United States)

    Cabanes, C.; Grouazel, A.; von Schuckmann, K.; Hamon, M.; Turpin, V.; Coatanoan, C.; Paris, F.; Guinehut, S.; Boone, C.; Ferry, N.; de Boyer Montégut, C.; Carval, T.; Reverdin, G.; Pouliquen, S.; Le Traon, P.-Y.

    2013-01-01

    The French program Coriolis, as part of the French operational oceanographic system, produces the COriolis dataset for Re-Analysis (CORA) on a yearly basis. This dataset contains in-situ temperature and salinity profiles from different data types. The latest release CORA3 covers the period 1990 to 2010. Several tests have been developed to ensure a homogeneous quality control of the dataset and to meet the requirements of the physical ocean reanalysis activities (assimilation and validation). Improved tests include some simple tests based on comparison with climatology and a model background check based on a global ocean reanalysis. Visual quality control is performed on all suspicious temperature and salinity profiles identified by the tests, and quality flags are modified in the dataset if necessary. In addition, improved diagnostic tools have been developed - including global ocean indicators - which give information on the quality of the CORA3 dataset and its potential applications. CORA3 is available on request through the MyOcean Service Desk (http://www.myocean.eu/).

  12. The effect of interpolation methods in temperature and salinity trends in the Western Mediterranean

    Directory of Open Access Journals (Sweden)

    M. VARGAS-YANEZ

    2012-12-01

    Full Text Available Temperature and salinity data in the historical record are scarce and unevenly distributed in space and time and the estimation of linear trends is sensitive to different factors. In the case of the Western Mediterranean, previous works have studied the sensitivity of these trends to the use of bathythermograph data, the averaging methods or the way in which gaps in time series are dealt with. In this work, a new factor is analysed: the effect of data interpolation. Temperature and salinity time series are generated averaging existing data over certain geographical areas and also by means of interpolation. Linear trends from both types of time series are compared. There are some differences between both estimations for some layers and geographical areas, while in other cases the results are consistent. Those results which do not depend on the use of interpolated or non-interpolated data, neither are influenced by data analysis methods can be considered as robust ones. Those results influenced by the interpolation process or the factors analysed in previous sensitivity tests are not considered as robust results.

  13. Temperature and salinity variability in the Greek Seas based on POSEIDON stations time series: preliminary results

    Directory of Open Access Journals (Sweden)

    D. VELAORAS

    2013-07-01

    Full Text Available Temperature and salinity time series provided by three POSEIDON monitoring stations (buoys are examined in order to study the seasonal and interannual variability of the water mass characteristics. The sites at Athos (North Aegean Sea, E1M3A (Central Cretan Sea and Pylos (Eastern Ionian Sea were chosen, as these buoys provide measurements at various depths, while they represent 3 major basins respectively. The study of the T and S characteristics reveals important seasonal changes and highlights the particular characteristics of each basin. Dense water production in the Northern Aegean is found to be hindered by the presence of the surface Black Sea Water (BSW mass. On the other hand, the intermediate water mass in the Cretan Sea is shown to be ventilated during the winter season. A significant temperature and salinity increase has been monitored over both the Central Cretan and Eastern Ionian Seas starting from the middle of 2008 and 2009 respectively. This could possibly be attributed to changes in the intermediate water masses of the Eastern Mediterranean, without ruling out the possibility of water mass exchanges between the two basins.

  14. Role of trehalose in salinity and temperature tolerance in the model halophilic bacterium Chromohalobacter salexigens.

    Directory of Open Access Journals (Sweden)

    Mercedes Reina-Bueno

    Full Text Available The disaccharide trehalose is considered as a universal stress molecule, protecting cells and biomolecules from injuries imposed by high osmolarity, heat, oxidation, desiccation and freezing. Chromohalobacter salexigens is a halophilic and extremely halotolerant γ-proteobacterium of the family Halomonadaceae. In this work, we have investigated the role of trehalose as a protectant against salinity, temperature and desiccation in C. salexigens. A mutant deficient in the trehalose-6-phosphate synthase gene (otsA::Ω was not affected in its salt or heat tolerance, but double mutants ectoine- and trehalose-deficient, or hydroxyectoine-reduced and trehalose-deficient, displayed an osmo- and thermosensitive phenotype, respectively. This suggests a role of trehalose as a secondary solute involved in osmo- (at least at low salinity and thermoprotection of C. salexigens. Interestingly, trehalose synthesis was osmoregulated at the transcriptional level, and thermoregulated at the post-transcriptional level, suggesting that C. salexigens cells need to be pre-conditioned by osmotic stress, in order to be able to quickly synthesize trehalose in response to heat stress. C. salexigens was more sensitive to desiccation than E. coli and desiccation tolerance was slightly improved when cells were grown at high temperature. Under these conditions, single mutants affected in the synthesis of trehalose or hydroxyectoine were more sensitive to desiccation than the wild-type strain. However, given the low survival rates of the wild type, the involvement of trehalose and hydroxyectoine in C. salexigens response to desiccation could not be firmly established.

  15. Temporal variations of groundwater salinity and temperature in a tidal flat in front of a tide pool

    Science.gov (United States)

    Nakashita, Shinya; Hibino, Tadashi; Komai, Katsuaki; Narong, Touch

    2016-07-01

    A tidal flat in an estuary is a complex hydrological system, which is characterized by interactions between surface water in river and groundwater and is particularly driven by tides. Small-scale variability in the discharge or inflow could lead to variable results of surface groundwater salinity and temperature. In particular, there is a high possibility that a hydraulic head difference due to the presence of a tide pool, lagoon, or seep would cause the generation of small-scale spatial submarine groundwater discharge. This study investigates the spatio-temporal variations in surface groundwater salinity and temperature (0-50 cm depth) and the groundwater table in a tidal flat in the presence and absence of a tide pool. A tide pool formed in the Ota River diversion channel at the study observation site following the construction of a masonry revetment in the intertidal zone. We established observation sites at three locations to consider the effects of the presence or absence of a tide pool. Specifically, we measured the surface water in river and groundwater salinity, temperature, and level in the presence and absence of a tide pool in 2007 and 2009. Reviewing the past data based on these results, we found the characteristic variation of groundwater salinity around the tide pool during flood event in 2004. Groundwater salinity and temperature were directly measured by setting conductivity-temperature meters in the tidal flat. We conclude that the groundwater table in the presence of the tide pool was 20 cm higher than in areas where no tide pool existed. The temporal variation of groundwater salinity in the presence of the tide pool was 5 psu lower than those where a tide pool was absent. Moreover, we confirmed the increase in groundwater salinity up to 8 psu in the tidal flat during flood, when river water salinity was at 0 psu and groundwater salinity in the tide pool was at 10 psu. We consider that the high groundwater table, the low salinity, and the increase

  16. Assessing recent air-sea freshwater flux changes using a surface temperature-salinity space framework

    Science.gov (United States)

    Grist, Jeremy P.; Josey, Simon A.; Zika, Jan D.; Evans, Dafydd Gwyn; Skliris, Nikolaos

    2016-12-01

    A novel assessment of recent changes in air-sea freshwater fluxes has been conducted using a surface temperature-salinity framework applied to four atmospheric reanalyses. Viewed in the T-S space of the ocean surface, the complex pattern of the longitude-latitude space mean global Precipitation minus Evaporation (PME) reduces to three distinct regions. The analysis is conducted for the period 1979-2007 for which there is most evidence for a broadening of the (atmospheric) tropical belt. All four of the reanalyses display an increase in strength of the water cycle. The range of increase is between 2% and 30% over the period analyzed, with an average of 14%. Considering the average across the reanalyses, the water cycle changes are dominated by changes in tropical as opposed to mid-high latitude precipitation. The increases in the water cycle strength, are consistent in sign, but larger than in a 1% greenhouse gas run of the HadGEM3 climate model. In the model a shift of the precipitation/evaporation cells to higher temperatures is more evident, due to the much stronger global warming signal. The observed changes in freshwater fluxes appear to be reflected in changes in the T-S distribution of the Global Ocean. Specifically, across the diverse range of atmospheric reanalyses considered here, there was an acceleration of the hydrological cycle during 1979-2007 which led to a broadening of the ocean's salinity distribution. Finally, although the reanalyses indicate that the warm temperature tropical precipitation dominated water cycle change, ocean observations suggest that ocean processes redistributed the freshening to lower ocean temperatures.

  17. Qualified temperature, salinity and dissolved oxygen climatologies in a changing Adriatic Sea

    Directory of Open Access Journals (Sweden)

    M. Lipizer

    2014-02-01

    Full Text Available An updated climatology, based on a comprehensive dataset (1911–2009 of temperature, salinity and dissolved oxygen, has been produced for the whole Adriatic Sea with the Variational Inverse Method using the DIVA software. Climatological maps were produced at 26 levels and validated with Ordinary Cross Validation and with real vs. synthetic Temperature–Salinity diagram intercomparison. The concept of Climatology–Observation Misfit (COM has been introduced as an estimate of the physical variability associated with the climatological structures. In order to verify the temporal stability of the climatology, long-term variability has been investigated in the Mid Adriatic and the South Adriatic Pits, regarded as the most suitable records of possible long-term changes. Compared with previous climatologies, this study reveals a surface temperature rise (up to 2 °C, a clear deep dissolved oxygen minimum in the South Adriatic Gyre and a bottom summer oxygen minimum in the North Adriatic. Below 100 m all properties profoundly differ between the Middle and the South Adriatic. The South Adriatic Pit clearly shows the remote effects of the Eastern Mediterranean Transient, while no effect is observed in Middle Adriatic Pits. The deepest part of the South Adriatic seems now to be significantly saltier (+0.18 since the period 1911–1914, with an increase of +0.018 decade−1 since the late 1940s and warmer (+0.54 °C since 1911–1914, even though a long-term temperature trend could not be statistically demonstrated. Conversely, the Middle Adriatic Pits present a long-term increase in apparent oxygen utilisation (+0.77 mL L−1 since 1911–1914, with a constant increase of +0.2 mL L−1 decade−1 after the 1970s.

  18. Research on surfactant flooding in high temperature and high-salinity reservoir for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ming [Southwest Petroleum Univ., Chengdu, Sichuan (China). State Key Lab. of Oil and Gas Reservoir Geology and Exploitation; Southwest Petroleum Univ., Chengdu, Sichuan (China). School of Material Science and Engineering; Zhao, Jinzhou; Yang, Yan [Southwest Petroleum Univ., Chengdu, Sichuan (China). State Key Lab. of Oil and Gas Reservoir Geology and Exploitation; Wang, Xu [Southwest Petroleum Univ., Chengdu, Sichuan (China). School of Material Science and Engineering

    2013-05-15

    The aim of this work was to research the solution properties of a new surfactant flooding system for high temperature and high salinity reservoir, which include trimeric sulfonate surfactants 1,2,3-tri(2-oxypropyl sulfonation-3-alkylether-propoxyl) propanes (TTSS-n) and anion-nonionic surfactant NPSO [sodium nonyl phenol polyethyleneoxy ether sulfonate, (EO = 10)]. The critical micelle concentrations (CMCs) of five trimeric sulfonate surfactants were smaller than 400 mg L{sup -1}. Furthermore, their interfacial tensions (IFTs) could reach an ultralow value with Tazhong 4 oil at lower concentrations. Through optimized formulation, we found that TTSS-12 had better properties and was selected as the major component of the surfactant flooding system. We designed an optimal formulation of the surfactant flooding system with 1000 mg . L{sup -1} TTSS-12 and 1000 mg . L{sup -1} NPSO surfactant. The system with a very small surfactant concentration could reach ultralow IFT with Tazhong 4 crude oils at high temperature (110 C) and high concentration formation brine (112,228.8 mg/L TDS), which proved that the simpler component surfactant had better reservoir compatibility. NPSO could weaken the disadvantage of the surfactant TTSS-12 in oil/water interface. The stability of this surfactant flooding system was evaluated by aging time, static adsorption and chromatographic separation. All experiments showed that it still keeps ultralow IFT in high temperature and high salinity conditions. Coreflooding experimentation showed that average oil recovery reached 9.8 wt% by surfactant flooding, therefore, it is feasible to use as a surfactant flooding system for enhanced oil recovery (EOR). (orig.)

  19. On the relative roles of hydrology, salinity, temperature, and root productivity in controlling soil respiration from coastal swamps (freshwater)

    Science.gov (United States)

    Krauss, Ken W.; Whitbeck, Julie L.; Howard, Rebecca J.

    2012-01-01

    Background and aims Soil CO2 emissions can dominate gaseous carbon losses from forested wetlands (swamps), especially those positioned in coastal environments. Understanding the varied roles of hydroperiod, salinity, temperature, and root productivity on soil respiration is important in discerning how carbon balances may shift as freshwater swamps retreat inland with sea-level rise and salinity incursion, and convert to mixed communities with marsh plants. Methods We exposed soil mesocosms to combinations of permanent flooding, tide, and salinity, and tracked soil respiration over 2 1/2 growing seasons. We also related these measurements to rates from field sites along the lower Savannah River, Georgia, USA. Soil temperature and root productivity were assessed simultaneously for both experiments. Results Soil respiration from mesocosms (22.7-1678.2 mg CO2 m-2 h-1) differed significantly among treatments during four of the seven sampling intervals, where permanently flooded treatments contributed to low rates of soil respiration and tidally flooded treatments sometimes contributed to higher rates. Permanent flooding reduced the overall capacity for soil respiration as soils warmed. Salinity did reduce soil respiration at times in tidal treatments, indicating that salinity may affect the amount of CO2 respired with tide more strongly than under permanent flooding. However, soil respiration related greatest to root biomass (mesocosm) and standing root length (field); any stress reducing root productivity (incl. salinity and permanent flooding) therefore reduces soil respiration. Conclusions Overall, we hypothesized a stronger, direct role for salinity on soil respiration, and found that salinity effects were being masked by varied capacities for increases in respiration with soil warming as dictated by hydrology, and the indirect influence that salinity can have on plant productivity.

  20. Nearshore fish distributions in an Alaskan estuary in relation to stratification, temperature, and salinity

    Science.gov (United States)

    Abookire, Alisa A.; Piatt, J.F.; Robards, Martin D.

    2000-01-01

    Fish were sampled with beach seines and small-meshed beam trawls in nearshore ( water from the Gulf of Alaska, whereas the Inner Bay is more estuarine. Thermohaline properties of bottom water in the Outer and Inner Bay were essentially the same, whereas the Inner Bay water-column was stratified with warmer, less saline waters near the surface. Distribution and abundance of pelagic schooling fish corresponded with area differences in stratification, temperature and salinity. The Inner Bay supported more species and higher densities of schooling and demersal fish than the Outer Bay. Schooling fish communities sampled by beach seine differed between the Outer and Inner Bays. Juvenile and adult Pacific sand lance (Ammodytes hexapterus), Pacific herring (Clupea harengus pallasi), osmerids (Osmeridae) and sculpins (Cottidae) were all more abundant in the Inner Bay. Gadids (Gadidae) were the only schooling fish taxa more abundant in the Outer Bay. Thermohaline characteristics of bottom water were similar throughout Kachemak Bay. Correspondingly, bottom fish communities were similar in all areas. Relative abundances (CPUE) were not significantly different between areas for any of the five demersal fish groups: flatfishes (Pleuronectidae), ronquils (Bathymasteridae), sculpins (Cottidae), gadids (Gadidae) and pricklebacks (Stichaeidae).

  1. Low Root Zone Temperature Exacerbates the Ion Imbalance and Photosynthesis Inhibition and Induces Antioxidant Responses in Tomato Plants Under Salinity

    Institute of Scientific and Technical Information of China (English)

    HE Yong; YANG Jing; ZHU Biao; ZHU Zhu-jun

    2014-01-01

    The combined effects of salinity with low root zone temperature (RZT) on plant growth and photosynthesis were studied in tomato (Solanum lycopersicum) plants. The plants were exposed to two different root zone temperatures (28/20°C, 12/8°C, day/night temperature) in combination with two NaCl levels (0 and 100 mmol L-1). After 2 wk of treatment, K+and Na+ concentration, leaf photosynthetic gas exchange, chlorophyll lfuorescence and leaf antioxidant enzyme activities were measured. Salinity signiifcantly decreased plant biomass, net photosynthesis rate, actual quantum yield of photosynthesis and concentration of K+, but remarkably increased the concentration of Na+. These effects were more pronounced when the salinity treatments were combined with the treatment of low RZT conditions. Either salinity or low RZT individually did not affect maximal efifciency of PSII photochemistry (Fv/Fm), while a combination of these two stresses decreased Fv/Fm considerably, indicating that the photo-damage occurred under such conditions. Non-photochemical quenching was increased by salt stress in accompany with the enhancement of the de-epoxidation state of the xanthophyll cycle, in contrast, this was not the case with low RZT applied individually. Salinity stress individually increased the activities of SOD, APX, GPOD and GR, and decreased the activities of DHAR. Due to the interactive effects of salinity with low RZT, these ifve enzyme activities increased sharply in the combined stressed plants. These results indicate that low RZT exacerbates the ion imbalance, PSII damage and photosynthesis inhibition in tomato plants under salinity. In response to the oxidative stress under salinity in combination with low RZT, the activities of antioxidant enzymes SOD, APX, GPOD, DHAR and GR were clearly enhanced in tomato plants.

  2. Quality Control of Temperature and Salinity from CTD based on Anomaly Detection

    CERN Document Server

    Castelão, Guilherme P

    2015-01-01

    The CTD is a set of sensors used by oceanographers to measure fundamental hydrographic properties of the oceans. It is characterized by a high precision product, only achieved if a quality control procedure identifies and removes the bad samples. Such procedure has been traditionally done by a sequence of independent tests that minimize false negatives. It is here proposed a novel approach to identify the bad samples as anomalies in respect to the typical behavior of good data. Several tests are combined into a single multidimensional evaluation to provide a more flexible classification criterion. The traditional approach is reproduced with an error of 0.04%, otherwise, the Anomaly Detection technique surpasses the reference if calibrated by visual inspection. CoTeDe is a Python package developed to apply the traditional and the Anomaly Detection quality control of temperature and salinity data from CTD, and can be extended to XBT, ARGO and other sensors.

  3. On the calculation of air-sea fluxes of CO2 in the presence of temperature and salinity gradients

    Science.gov (United States)

    Woolf, D. K.; Land, P. E.; Shutler, J. D.; Goddijn-Murphy, L. M.; Donlon, C. J.

    2016-02-01

    The presence of vertical temperature and salinity gradients in the upper ocean and the occurrence of variations in temperature and salinity on time scales from hours to many years complicate the calculation of the flux of carbon dioxide (CO2) across the sea surface. Temperature and salinity affect the interfacial concentration of aqueous CO2 primarily through their effect on solubility with lesser effects related to saturated vapor pressure and the relationship between fugacity and partial pressure. The effects of temperature and salinity profiles in the water column and changes in the aqueous concentration act primarily through the partitioning of the carbonate system. Climatological calculations of flux require attention to variability in the upper ocean and to the limited validity of assuming "constant chemistry" in transforming measurements to climatological values. Contrary to some recent analysis, it is shown that the effect on CO2 fluxes of a cool skin on the sea surface is large and ubiquitous. An opposing effect on calculated fluxes is related to the occurrence of warm layers near the surface; this effect can be locally large but will usually coincide with periods of low exchange. A salty skin and salinity anomalies in the upper ocean also affect CO2 flux calculations, though these haline effects are generally weaker than the thermal effects.

  4. Cyclic Patterns of Interaction between the Surface Gradient of Temperature, Salinity and Chlorophyll in the Open Ocean and the Coastal Zone

    Science.gov (United States)

    Kartushinsky, Alexei

    Satellite data were used to calculate mean gradient fields of temperature, salinity and chlorophyll concentration in the ocean for different periods of time. Also we used data buoy observations in situ and some numerical modeling results for a better understanding of the dynamic mechanisms involved and their role in the Global ocean and coastal zones. The high temperature and salinity gradient are formed under the periodically action of jet currents, large rings and eddies and upwelling, which transfer water masses in the ocean and influence the distribution of phytoplankton. The gradient fields and their high values give us information about spatial distribution of main frontal zones. The main stage of research is evaluation of statistical correlation between gradients of temperature, salinity and chlorophyll concentration, which suggests a combined effect of physical and biological processes in a synergistically active ocean zones. The software calculates and produces the averages horizontal gradients in the ocean for different grids. Calculations are also made to find latitudianal, meridional, and absolute gradients, pointing to main frontal zones. We conducted a study of cyclic patterns in relation to changes of gradient fields. Statistical relation of temperature, salinity and chlorophyll concentration gradients in various areas of the global ocean and coastal zone with various scales of space-time averaging was analyzed. Pair correlation of gradient fields for steady frontal zones was estimated. Numerous researches in the area show that the advection of currents, horizontal turbulent heat exchange and the radiation heat flow in separate parts of the ocean impact on the structure of gradient fields. Cycles of the gradient variability in the oceanic frontal zones can be used to assess pulse disturbance of the mass, heat transport and fluxes over the ocean and their interaction with atmosphere and subsequent impact on land ecosystems.

  5. Temperature, current meter, and other data using current meter, thermistor, and mooring casts from the HUNT from the Pacific Ocean as part of the International Decade of Ocean Exploration / International Southern Ocean Studies / First Dynamic Response and Kinematics Experiment in the Drake Passage (IDOE/ISOS/FDRAKE) project, from 28 June 1982 to 23 November 1983 (NODC Accession 9500019)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, conductivity, east-west current component, north-south current component, depth, pressure, and salinity data were collected using current meter,...

  6. Design of a CMOS temperature sensor with current output

    NARCIS (Netherlands)

    Kolling, A.; Kölling, Arjan; Bak, Frans; Bergveld, Piet; Seevinck, E.; Seevinck, Evert

    1990-01-01

    In this paper a CMOS temperature-to-current converter is presented of which the output current is the difference between a PTC current and an NTC current. The PTC current is derived from a PTAT cell, while the NTC current is derived from a threshold voltage reference source. It is shown that this

  7. Synergistic Effects of Salinity and Temperature on the Survival of Two Nonnative Bivalve Molluscs, Perna viridis (Linnaeus 1758) and Mytella charruana (d'Orbigny 1846)

    National Research Council Canada - National Science Library

    Wei S. Yuan; Linda J. Walters; Sasha A. Brodsky; Kimberly R. Schneider; Eric A. Hoffman

    2016-01-01

      This study examined the combined salinity and temperature tolerance of two marine bivalve molluscs, Perna viridis and Mytella charruana, which have recently invaded the southeastern United States...

  8. Multidecadal variability of potential temperature, salinity, and transport in the eastern subpolar North Atlantic

    Science.gov (United States)

    Holliday, N. P.; Cunningham, S. A.; Johnson, C.; Gary, S. F.; Griffiths, C.; Read, J. F.; Sherwin, T.

    2015-09-01

    The Extended Ellett Line (EEL) hydrographic section extends from Scotland to Iceland crossing the Rockall Trough, Hatton-Rockall Basin, and Iceland Basin. With 61 full-depth stations at a horizontal resolution of 10-50 km, the EEL samples the upper limb of the Atlantic Meridional Overturning Circulation flowing across the Iceland-Scotland Ridge into the Nordic Seas. The Rockall Trough has been sampled nearly four times per year from 1975 to 1996, and the full section annually since 1996. The EEL is an exceptionally long-time series of deep ocean temperatures and salinities. This study extends prior work in the Rockall Trough, and examines for the first time 18 year records in the Iceland and Hatton-Rockall Basins. We quantify errors in the time series from two sources: observational errors and aliasing. The data quality and annual sampling are suitable for observing interannual to decadal variability because the variability exceeds our error estimates. The upper waters of all three basins are cooler/fresher from 1997 to 2001, warmer/more saline 2001-2006, and cooler/fresher from 2006 to 2014. A reference level for geostrophic shear is developed heuristically and by comparison with sea-surface altimetry. The mean northward transport in the upper waters is 6.7 ± 3.7 Sv and there is a 6.1 ± 2.5 Sv southward flow below the thermocline. Although the magnitude of the Iceland Basin overturning circulation (4.3 ± 1.9 Sv) is greater than in the Rockall Trough (3.0 ± 3.7 Sv), the variability is greater in the Rockall Trough. We discuss the results in the context of our understanding of drivers of variability.

  9. Characteristics and inter-annual changes in temperature, salinity and density distribution in the Gulf of Riga

    Directory of Open Access Journals (Sweden)

    Maris Skudra

    2017-01-01

    Full Text Available Available CTD profiles from the Gulf of Riga (May–August, 1993–2012 were analyzed to study inter-annual and long-term changes in temperature, salinity and density in relation to river runoff and atmospheric forcing (e.g. Baltic Sea Index. To describe temporal changes in vertical stratification, the upper mixed layer (UML and deep layer (DL parameters were estimated. On average the UML depth increases from 8.7 m in May to 9.0, 11.5 and 13.7 m in June, July and August, respectively, and the UML temperature increases from 8.0°C to 12.5, 18.7 and 18.6°C (May, June, July and August while the UML salinity increases from 4.90 g kg−1 to 5.14, 5.28 and 5.38 g kg−1, respectively. High correlation (r = −0.82 was found between the inter-annual changes in river runoff (spring and mean salinity in the UML in August as well as between DL mean salinity (r = 0.88 and density (r = 0.84 in the Irbe Strait and DL mean salinity and density in the Gulf of Riga. Inter-annual changes in the UML depth as well as in DL salinity and density had a significant correlation with the changes in Baltic Sea Index. The strongest stratification (August can be observed in the years with the highest UML temperature and the highest river run-off in spring. We suggest that the predicted increase in water temperature and changes in river run-off due to the climate change would result in faster development of the seasonal thermocline in spring and stronger vertical stratification in summer.

  10. The effect of temperature, salinity and nitrogen products on food consumption of pink shrimp Farfantepenaeus paulensis

    Directory of Open Access Journals (Sweden)

    Wilson Wasielesky Jr.

    2003-01-01

    Full Text Available Studies were carried out to investigate the effect of temperature, salinity, ammonia, nitrite and nitrate on food consumption of pink shrimp Farfantepenaeus paulensis. Juveniles (0.2 - 0.4 g were acclimated for 15 days in seawater with different temperatures, salinities and concentrations of ammonia, nitrite and nitrate. After the acclimation period, 20 shrimps per treatment were individualized in order to have their ration intake analyzed through the amount of ration offered and left over within a 24-hour period. Mean food consumption presented significant alterations (P0.05. According to the results obtained, temperature and nitrite affected F. paulensis food consumption. On the other hand, variables as salinity, ammonia and nitrate did not affect shrimp appetite. However, the possibility of this to happen over long periods, prejudicing the species culture in captivity, reinforced the necessity of regular water quality management.Nos cultivos de organismos aquáticos, a manutenção da qualidade da água é fundamental para o sucesso da atividade, tendo em vista que variações nos parâmetros físico-químicos implicam em alterações metabólicas. O consumo de alimento por parte dos camarões pode ser afetado por estas variações, o que interfere nas taxas de crescimento e conseqüentemente na biomassa final produzida. O objetivo deste trabalho foi investigar o efeito da temperatura, salinidade, amônia, nitrito e nitrato sobre o consumo alimentar do camarão-rosa Farfantepenaeus paulensis. Desta forma, juvenis (0,2-0,4 g foram aclimatados por 15 dias em água do mar com diferentes temperaturas, salinidades, concentrações de amônia, nitrito e nitrato. Após o período de aclimatação, 20 camarões de cada tratamento foram individualmente analisados para observar a relação entre a quantidade de alimento oferecido e a quantidade de alimento ingerido, em um período de 24 horas. O consumo médio apresentou alterações significativas (p0

  11. Salinity and temperature effects on the growth and chlorophyll-a content of some planktonic aigae

    Directory of Open Access Journals (Sweden)

    Teresa Cristina Siqueira Sigaud

    1993-01-01

    Full Text Available The effect of salinity (0-40 %o and temperature (11-36ºC, at 5ºC intervals variations on maximum growth rate (div d-1, maximum yield (logio cell number and chlorophyll-α content (pg cell-1 of four planktonic algae was examined under laboratory conditions. Phaeodactylum tricornutum grew over the entire range of experimental salinities, at 11-26 ºC. The highest maximum growth rates ( 1.6 div d-1 occurred between 9-30 %o and 16-26 ºC. Optimum salinity range for maximum yield (7.0 was found at 9-35 %c, under 16 ºC. Tetraselmis gracilis reproduced from 4 to 40 %o at 11-31 ºC, with the highest values of maximum growth rate ( 1.6 div d-1 and maximum yield (6.1 occurring at salinities between 14-40 %o at 11-21 ºC and 11-16 ºC, respectively. Minutocellus polymorphic and Chaetoceros sp grew between 9-40 %o and 11-31 ºC. Their highest maximum growth rates (2.1 and 2.6 div d-1, respectively were found at 31ºC, between 20-35 %o and 20-40 %o, respectively. The highest maximum yields for AT. polymorphic (7.2 were recorded between 16-21 ºC at 20-40 %o and for Chaetoceros sp (6.8, between 25-40 %o at 16-31ºC. Chlorophyll-a content per cell was not conspicuously associated to temperature and salinity for the four species. At low salinity extremes, when cell division was inhibited, an increase in the amount of chlorophyll-a per cell was detected.Estudou-se o efeito de variações de salinidade (0-40 %o e temperatura (11-36ºC, em intervalos de 5ºC sobre a taxa máxima de crescimento (div d-1, o rendimento máximo (logio nº cel ml"¹ e o conteúdo de clorofíla-a (pg cel-1 de quatro espécies de algas planctónicas, sob condições de laboratório. Phaeodactylum tricornutum cresceu em toda a amplitude de salinidade experimental e entre 11-26ºC. As mais altas taxas de crescimento (1.6 div d-1 foram obtidas entre 9-30 %o e 16-26ºC. O ótimo de salinidade para o rendimento máximo (7.0 foi observado entre 9- 35%o, à 16ºC. Tetraselmis gracilis se

  12. Bacterial responses to fluctuations and extremes in temperature and brine salinity at the surface of Arctic winter sea ice.

    Science.gov (United States)

    Ewert, Marcela; Deming, Jody W

    2014-08-01

    Wintertime measurements near Barrow, Alaska, showed that bacteria near the surface of first-year sea ice and in overlying saline snow experience more extreme temperatures and salinities, and wider fluctuations in both parameters, than bacteria deeper in the ice. To examine impacts of such conditions on bacterial survival, two Arctic isolates with different environmental tolerances were subjected to winter-freezing conditions, with and without the presence of organic solutes involved in osmoprotection: proline, choline, or glycine betaine. Obligate psychrophile Colwellia psychrerythraea strain 34H suffered cell losses under all treatments, with maximal loss after 15-day exposure to temperatures fluctuating between -7 and -25 °C. Osmoprotectants significantly reduced the losses, implying that salinity rather than temperature extremes presents the greater stress for this organism. In contrast, psychrotolerant Psychrobacter sp. strain 7E underwent miniaturization and fragmentation under both fluctuating and stable-freezing conditions, with cell numbers increasing in most cases, implying a different survival strategy that may include enhanced dispersal. Thus, the composition and abundance of the bacterial community that survives in winter sea ice may depend on the extent to which overlying snow buffers against extreme temperature and salinity conditions and on the availability of solutes that mitigate osmotic shock, especially during melting.

  13. Salinity, Temperature, and Optical Characterization of a Tidally Choked Estuary Connected to Two Contrasting Intra-Coastal Waterways

    Science.gov (United States)

    2013-06-01

    performed better than salinity and temperature alone in distinguishing fine-scale, ocean structures in satellite imagery ( Palacios et al. 2012). By... Palacios , S. L., T. D. Peterson, and R. M. Kudela, 2012: Optical characterization of water masses within the Columbia River Plume. JGR, 117, C11020

  14. Effect of temperature and salinity on stable isotopic composition of shallow water benthic foraminifera: A laboratory culture study

    Digital Repository Service at National Institute of Oceanography (India)

    Kurtarkar, S.R.; Linshy, V.N.; Saraswat, R.; Nigam, R.

    in the laboratory. In the present work, shallow water benthic foraminiferal species, Rosalina sp. and Pararotalia nipponica were subjected to different combinations of seawater temperature (25�C to 35�C) and salinity (25 psu to 37 psu) in the laboratory to assess...

  15. Spectra and gross features of vertical temperature and salinity profiles off the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.; Nagarajan, R.

    . The estimates of spectral density for temperature and salinity were comparatively very high for low wave numbers and showed a difference varying from 1.5 to 2 decades. The spectra for the range 0-0.11 cy/m computed using the perturbation series from a first...

  16. Temperature and salinity changes associated with the Paleocene-Eocene Carbon Isotope Excursion along the mid Atlantic margin

    Science.gov (United States)

    Makarova, M.; Miller, K. G.; Wright, J. D.; Rosenthal, Y.; Babila, T. L.

    2015-12-01

    The Paleocene-Eocene Thermal Maximum (PETM) was an abrupt warming event, characterized by a global temperature increase of about 5-8°C and associated with the Carbon Isotope Excursion (CIE) of ~2.5-4‰ in marine environments. Here we evaluate temperature and salinity changes across the Paleocene/Eocene boundary in the Millville New Jersey coastal plain core (ODP Leg 174AX) using two independent temperature proxies (the organic paleothermometer TEX86 and Mg/Ca ratio of planktonic foraminifera) and δ18O of planktonic foraminifera. Paleotemperature estimates show warming of 5-7°C during the CIE, though different temperature calibrations provide a broad range of absolute temperatures. We argue that the temperature calibration of TEXL 86 provides the best temperature estimate (warming from 23°C to 30°C) because it is the only one that yields realistic salinities, whereas the TEXH 86 calibration yields extremely high sea surface salinities (~48 psu in the latest Paleocene). In contrast to the previous studies, use of the correct calibration effectively eliminates any temperature increase prior to the CIE suggesting that temperature was not the trigger for the massive release of carbon. A salinity decrease of at least ~4 psu was associated with the onset of the CIE/PETM. This implies freshening of surface and thermocline waters supports the hypothesis of an enhanced hydrological cycle. We conclude that our results are consistent with the hypothesis of Appalachian Amazon river system development and increased river runoff to the New Jersey continental margin during the PETM.

  17. Sea surface salinity and temperature seasonal changes in the Solomon and Bismarck Seas

    Science.gov (United States)

    Delcroix, Thierry; Radenac, Marie-Helene; Cravatte, Sophie; Gourdeau, Lionel; Alory, Gael

    2014-05-01

    Small SST and SSS (an indicator of iron-rich Papua New Guinea river outflows) changes in the Solomon and Bismarck Seas may be transported to the equatorial Pacific and have strong climatic and biological impacts. We analyze mean and seasonal change of SST and SSS in the Solomon and Bismarck Seas, using 1977-2009 in situ data collected from Voluntary Observing Ships. Co-variability of these two variables with surface wind, altimeter-derived current anomalies, precipitation, and Sepik river discharge is examined. SST and SSS show large annual oscillations in the Solomon Sea, with the coldest and saltiest waters occurring in July/August mainly due to horizontal advection. In contrast, they show large semi-annual oscillations in the Bismarck Sea. There, the coldest and saltiest waters happen in January/February, when the northwest monsoon winds drive coastal upwelling, and in July/August, when the New Guinea Coastal Current advects cold and high-salinity waters from the Solomon Sea through Vitiaz Strait. The low SSS values observed in April/May, stuck between the two SSS maxima, are further enhanced by the Sepik river discharge annual maximum. A high-resolution model strengthens the conclusions we derive from observations. The impacts of ENSO on SST and SSS are also discussed.

  18. Temperature compensated and self-calibrated current sensor using reference current

    Science.gov (United States)

    Yakymyshyn, Christopher Paul; Brubaker, Michael Allen; Yakymyshyn, Pamela Jane

    2008-01-22

    A method is described to provide temperature compensation and self-calibration of a current sensor based on a plurality of magnetic field sensors positioned around a current carrying conductor. A reference electrical current carried by a conductor positioned within the sensing window of the current sensor is used to correct variations in the output signal due to temperature variations and aging.

  19. Growth, photosynthesis and pollen performance in saline water treated olive plants under high temperature

    Directory of Open Access Journals (Sweden)

    Georgios C. Koubouris

    2015-10-01

    Full Text Available Olive cultivation in hot arid areas is hindered by the scarcity of irrigation water. The exploitation of saline water has been proposed as a solution to partially cover plant water demands. This paper presents the effects of salinity [0, 60 and 120 mM sodium chloride (NaCl] on physiological and reproductive functions of cultivars Koroneiki and Amphissis in a closed hydroponic system. Shoot growth was markedly reduced in high salinity dose in Amphissis (−81% and Koroneiki (−75%. The photosynthetic rate was significantly reduced at 120 mM NaCl for both cultivars, as well as chlorophyll and carotenoids content (43% and 44%, respectively. The Na+ content in all plant parts increased in both salinity doses especially in Amphissis while K concentration decreased for both cultivars. Inflorescences in Amphissis were severely damaged due to salinity. Consequently, pollen sampling and in vitro germination study was only feasible for Koroneiki. Indeed, Koroneiki pollen germination was reduced at 60 mM NaCl (−42% and at 120 mM NaCl (−88%. Pollen tube length was also reduced by 15% and 28% for the middle and high salinity dose, respectively. The results of the present study indicate that Amphissis is more sensitive in high salinity doses compared to Koroneiki and that reproductive functions are severely affected by salinity.

  20. Effects of salinity, light and temperature on growth rates of two species of Gracilaria (Rhodophyta)

    Institute of Scientific and Technical Information of China (English)

    XU Yongjian; WEI Wei; FANG Jianguang

    2009-01-01

    Effects of temperature, salinity and light intensity on growth rates of Gracilaria lichenoides and G tenuistipitata var. liui Zhang et Xia were tested. Eight to ten levels of each factor were first tested separately. The best growth rate was obtained under the conditions of 32~C, 30 and 240 μmol/(m2·s) for G. lichenoides, and 24℃, 20 and 200 μmol/(m2.s) for G. tenuistipitata, respectively. Then a uniform design was used to evaluate the optimal combinations of the three factors. The best conditions for the highest daily specific growth rates (% increase in wet weight) are determined to be 31.30℃, 32.10, and 287.23 μmol/(m2·s) for G. lichenoides (16.26%/d), and 25.38℃, 21.10, and 229.07 μmol/(m2·s) for G. tenuistipitata (14.83%/d), respectively.

  1. Biogeography of pelagic bacterioplankton across an antagonistic temperature-salinity gradient in the Red Sea

    KAUST Repository

    Ngugi, David

    2011-12-01

    The Red Sea is a unique marine ecosystem with contrasting gradients of temperature and salinity along its north-to-south axis. It is an extremely oligotrophic environment that is characterized by perpetual year-round water column stratification, high annual solar irradiation, and negligible riverine and precipitation inputs. In this study, we investigated whether the contemporary environmental conditions shape community assemblages by pyrosequencing 16S rRNA genes of bacteria in surface water samples collected from the northeastern half of this water body. A combined total of 1855 operational taxonomic units (OTUs) were recovered from the \\'small-cell\\' and \\'large-cell\\' fractions. Here, a few major OTUs affiliated with Cyanobacteria and Proteobacteria accounted for â93% of all sequences, whereas a tail of \\'rare\\' OTUs represented most of the diversity. OTUs allied to Surface 1a/b SAR11 clades and Prochlorococcus related to the high-light-adapted (HL2) ecotype were the most widespread and predominant sequence types. Interestingly, the frequency of taxa that are typically found in the upper mesopelagic zone was significantly elevated in the northern transects compared with those in the central, presumably as a direct effect of deep convective mixing in the Gulf of Aqaba and water exchange with the northern Red Sea. Although temperature was the best predictor of species richness across all major lineages, both spatial and environmental distances correlated strongly with phylogenetic distances. Our results suggest that the bacterial diversity of the Red Sea is as high as in other tropical seas and provide evidence for fundamental differences in the biogeography of pelagic communities between the northern and central regions. © 2011 Blackwell Publishing Ltd.

  2. Effects of salinity and temperature on in vitro cell cycle and proliferation of Perkinsus marinus from Brazil.

    Science.gov (United States)

    Queiroga, Fernando Ramos; Marques-Santos, Luis Fernando; De Medeiros, Isac Almeida; Da Silva, Patrícia Mirella

    2016-04-01

    Field and in vitro studies have shown that high salinities and temperatures promote the proliferation and dissemination of Perkinsus marinus in several environments. In Brazil, the parasite infects native oysters Crassostrea gasar and Crassostrea rhizophorae in the Northeast (NE), where the temperature is high throughout the year. Despite the high prevalence of Perkinsus spp. infection in oysters from the NE of Brazil, no mortality events were reported by oyster farmers to date. The present study evaluated the effects of salinity (5, 20 and 35 psu) and temperature (15, 25 and 35 °C) on in vitro proliferation of P. marinus isolated from a host (C. rhizophorae) in Brazil, for a period of up to 15 days and after the return to the control conditions (22 days; recovery). Different cellular parameters (changes of cell phase's composition, cell density, viability and production of reactive oxygen species) were analysed using flow cytometry. The results indicate that the P. marinus isolate was sensitive to the extreme salinities and temperatures analysed. Only the highest temperature caused lasting cell damage under prolonged exposure, impairing P. marinus recovery, which is likely to be associated with oxidative stress. These findings will contribute to the understanding of the dynamics of perkinsiosis in tropical regions.

  3. Impact of Ganges–Brahmaputra interannual discharge variations on Bay of Bengal salinity and temperature during 1992–1999 period

    Indian Academy of Sciences (India)

    Fabien Durand; Fabrice Papa; Atiqur Rahman; Sujit Kumar Bala

    2011-10-01

    This study investigates the impact of monthly Ganges–Brahmaputra river discharge variations on Bay of Bengal salinity and temperature during the period 1992–1999. The Ganges–Brahmaputra river discharge is characterized by a well-defined seasonal cycle with strong interannual variations. The highest/lowest yearly peak discharge occurs in summer 1998/summer 1992, with 1998 value amounting to twice that of 1992. This river discharge is then used to force an ocean general circulation model. Our main result is that the impact of these rivers on the variability of Bay of Bengal sea surface salinity is strong in the northern part, with excess run-off forcing fresh anomalies, and vice versa. Most of the years, the influence of the interannual variability of river discharge on the Bay salinity does not extend south of ∼10° N. This stands in contrast with the available observations and is probably linked to the relatively coarse resolution of our model. However, the extreme discharge anomaly of 1998 is exported through the southern boundary of the Bay and penetrates the south-eastern Arabian Sea a few months after the discharge peak. In response to the discharge anomalies, the model simulates significant mixed-layer temperature anomalies in the northern Bay of Bengal. This has the potential to influence the climate of the area. From our conclusions, it appears necessary to use a numerical model with higher resolution (both on the horizontal and vertical) to quantitatively investigate the upper Bay of Bengal salinity structure.

  4. Capacitive mixing power production from salinity gradient energy enhanced through exoelectrogen-generated ionic currents

    KAUST Repository

    Hatzell, Marta C.

    2014-01-01

    Several approaches to generate electrical power directly from salinity gradient energy using capacitive electrodes have recently been developed, but power densities have remained low. By immersing the capacitive electrodes in ionic fields generated by exoelectrogenic microorganisms in bioelectrochemical reactors, we found that energy capture using synthetic river and seawater could be increased ∼65 times, and power generation ∼46 times. Favorable electrochemical reactions due to microbial oxidation of organic matter, coupled to oxygen reduction at the cathode, created an ionic flow field that enabled more effective passive charging of the capacitive electrodes and higher energy capture. This ionic-based approach is not limited to the use of river water-seawater solutions. It can also be applied in industrial settings, as demonstrated using thermolytic solutions that can be used to capture waste heat energy as salinity gradient energy. Forced charging of the capacitive electrodes, using energy generated by the bioelectrochemical system and a thermolytic solution, further increased the maximum power density to 7 W m -2 (capacitive electrode). © 2014 The Royal Society of Chemistry.

  5. The larvae of congeneric gastropods showed differential responses to the combined effects of ocean acidification, temperature and salinity.

    Science.gov (United States)

    Zhang, Haoyu; Cheung, S G; Shin, Paul K S

    2014-02-15

    The tolerance and physiological responses of the larvae of two congeneric gastropods, the intertidal Nassarius festivus and subtidal Nassarius conoidalis, to the combined effects of ocean acidification (pCO2 at 380, 950, 1250 ppm), temperature (15, 30°C) and salinity (10, 30 psu) were compared. Results of three-way ANOVA on cumulative mortality after 72-h exposure showed significant interactive effects in which mortality increased with pCO2 and temperature, but reduced at higher salinity for both species, with higher mortality being obtained for N. conoidalis. Similarly, respiration rate of the larvae increased with temperature and pCO2 level for both species, with a larger percentage increase for N. conoidalis. Larval swimming speed increased with temperature and salinity for both species whereas higher pCO2 reduced swimming speed in N. conoidalis but not N. festivus. The present findings indicated that subtidal congeneric species are more sensitive than their intertidal counterparts to the combined effects of these stressors.

  6. The SeaDataNet data products: regional temperature and salinity historical data collections

    Science.gov (United States)

    Simoncelli, Simona; Coatanoan, Christine; Bäck, Orjan; Sagen, Helge; Scoy, Serge; Myroshnychenko, Volodymyr; Schaap, Dick; Schlitzer, Reiner; Iona, Sissy; Fichaut, Michele

    2016-04-01

    Temperature and Salinity (TS) historical data collections covering the time period 1900-2013 were created for each European marginal sea (Arctic Sea, Baltic Sea, Black Sea, North Sea, North Atlantic Ocean and Mediterranean Sea) within the framework of SeaDataNet2 (SDN) EU-Project and they are now available as ODV collections through the SeaDataNet web catalog at http://sextant.ifremer.fr/en/web/seadatanet/. Two versions have been published and they represent a snapshot of the SDN database content at two different times: V1.1 (January 2014) and V2 (March 2015). A Quality Control Strategy (QCS) has been developped and continuously refined in order to improve the quality of the SDN database content and to create the best product deriving from SDN data. The QCS was originally implemented in collaboration with MyOcean2 and MyOcean Follow On projects in order to develop a true synergy at regional level to serve operational oceanography and climate change communities. The QCS involved the Regional Coordinators, responsible of the scientific assessment, the National Oceanographic Data Centers (NODC) and the data providers that, on the base of the data quality assessment outcome, checked and eventually corrected anomalies in the original data. The QCS consists of four main phases: 1) data harvesting from the central CDI; 2) file and parameter aggregation; 3) quality check analysis at regional level; 4) analysis and correction of data anomalies. The approach is iterative to facilitate the upgrade of SDN database content and it allows also the versioning of data products with the release of new regional data collections at the end of each QCS loop. SDN data collections and the QCS will be presented and the results summarized.

  7. Temperature induced decay of persistent currents in superfluid ultracold gas

    CERN Document Server

    Kumar, Avinash; Jendrzejewski, Fred; Campbell, Gretchen K

    2016-01-01

    We study how temperature affects the lifetime of a quantized, persistent current state in a toroidal Bose-Einstein condensate (BEC). When the temperature is increased, we find a decrease in the persistent current lifetime. Comparing our measured decay rates to simple models of thermal activation and quantum tunneling, we do not find agreement. The measured critical velocity is also found to depend strongly on temperature, approaching the zero temperature mean-field solution as the temperature is decreased. This indicates that an appropriate definition of critical velocity must incorporate the role of thermal fluctuations, something not explicitly contained in traditional theories.

  8. Assessment of Well Safety from Pressure and Temperature-Induced Damage during CO2 Injection in Deep Saline Aquifers

    Science.gov (United States)

    Singh, A. K.; Delfs, J.; Goerke, U.; Kolditz, O.

    2013-12-01

    Carbon dioxide Capture and Storage (CCS) technology is known for disposing a specific amount of CO2 from industrial release of flue gases into a suitable storage where it stays for a defined period of time in a safe way. Types of storage sites for CO2 are depleted hydrocarbon reservoirs, unmineable coal seams and saline aquifers. In this poster, we address the problem of CO2 sequestration into deep saline aquifers. The main advantage of this kind of site for the CO2 sequestration is its widespread geographic distribution. However, saline aquifers are very poorly characterized and typically located at one kilometer depth below the earth's surface. To demonstrate that supercritical CO2 injection into deep saline aquifers is technically and environmentally safe, it is required to perform thermo-hydro-mechanical analysis of failure moods with numerical models. In the poster, we present simple process-catching benchmark for testing the scenario of compressed CO2 injection into a multi- layered saline aquifer.The pores of the deformable matrix are initially filled with saline water at hydrostatic pressure and geothermal temperature conditions. This benchmark investigates (i) how the mechanical and thermal stresses enhance the permeability for CO2 migration; and (ii) subsequent failures mode, i.e., tensile, and shear failures. The tensile failure occurs when pore fluid pressure exceeds the principle stress whereas the Mohr-Coulomb failure criterion defines the shear failure mode. The thermo-hydro-mechanical (THM) model is based on a ';multi-componential flow' module . The coupled system of balance equations is solvedin the monolithic way. The Galerkin finite element approach is used for spatial discretization, whereas temporal discretization is performed with a generalized single step scheme. This numerical module has been implemented in the open-source scientific software OpenGeoSys.

  9. Contribution For Arc Temperature Affected By Current Increment Ratio At Peak Current In Pulsed Arc

    Science.gov (United States)

    Kano, Ryota; Mitubori, Hironori; Iwao, Toru

    2015-11-01

    Tungsten Inert Gas (TIG) Welding is one of the high quality welding. However, parameters of the pulsed arc welding are many and complicated. if the welding parameters are not appropriate, the welding pool shape becomes wide and shallow.the convection of driving force contributes to the welding pool shape. However, in the case of changing current waveform as the pulse high frequency TIG welding, the arc temperature does not follow the change of the current. Other result of the calculation, in particular, the arc temperature at the reaching time of peak current is based on these considerations. Thus, the accurate measurement of the temperature at the time is required. Therefore, the objective of this research is the elucidation of contribution for arc temperature affected by current increment ratio at peak current in pulsed arc. It should obtain a detail knowledge of the welding model in pulsed arc. The temperature in the case of increment of the peak current from the base current is measured by using spectroscopy. As a result, when the arc current increases from 100 A to 150 A at 120 ms, the transient response of the temperature didn't occur during increasing current. Thus, during the current rise, it has been verified by measuring. Therefore, the contribution for arc temperature affected by current increment ratio at peak current in pulsed arc was elucidated in order to obtain more knowledge of welding model of pulsed arc.

  10. [Nebulized hypertonic saline and acute viral bronchiolitis in infants: current aspects].

    Science.gov (United States)

    Sauvaget, E; David, M; Bresson, V; Retornaz, K; Bosdure, E; Dubus, J-C

    2012-06-01

    Acute viral bronchiolitis affects infants, is frequent, and can be severe. Its treatment is only based on symptoms. Hypertonic saline (HS) may act favorably in this situation by fighting virus-induced dehydration of the airway liquid surface. Because of an osmotic action, HS attracts the water from the epithelial cells and improves mucociliary clearance. Five double-blind placebo-controlled studies concerning hospitalized infants with acute viral bronchiolitis showed that repeated nebulizations of 3% HS induce a 20% improvement in the clinical severity score and reduced the hospital length of stay by 24h. Tolerance is excellent. On the other hand, a few questions remain unresolved: what is the optimal salt concentration? What is the recommended nebulizer? What is the best frequency for nebulizer use? Can nebulized HS be used at home? What are the results with systematic physiotherapy when HS is used?

  11. The effect of salinity, redox mediators and temperature on anaerobic biodegradation of petroleum hydrocarbons in microbial fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Adelaja, Oluwaseun, E-mail: o.adelaja@my.westminster.ac.uk; Keshavarz, Tajalli, E-mail: t.keshavarz@westminster.ac.uk; Kyazze, Godfrey, E-mail: g.kyazze@westminster.ac.uk

    2015-02-11

    Highlights: • Effective degradation of petroleum hydrocarbon mixtures was achieved using MFC. • Adapted anaerobic microbial consortium was used as inoculum. • Bio-electricity generation was enhanced by 30-fold when riboflavin, was added. • Optimum MFC performance was obtained at mesophilic and moderately saline conditions. • Stable MFC performance was obtained during prolonged fed-batch MFC operation. - Abstract: Microbial fuel cells (MFCs) need to be robust if they are to be applied in the field for bioremediation. This study investigated the effect of temperature (20–50 °C), salinity (0.5–2.5% (w/v) as sodium chloride), the use of redox mediators (riboflavin and anthraquinone-2-sulphonate, AQS) and prolonged fed-batch operation (60 days) on biodegradation of a petroleum hydrocarbon mix (i.e. phenanthrene and benzene) in MFCs. The performance criteria were degradation efficiency, % COD removal and electrochemical performance. Good electrochemical and degradation performance were maintained up to a salinity of 1.5% (w/v) but deteriorated by 35-fold and 4-fold respectively as salinity was raised to 2.5%w/v. Degradation rates and maximum power density were both improved by approximately 2-fold at 40 °C compared to MFC performance at 30 °C but decreased sharply by 4-fold when operating temperature was raised to 50 °C. The optimum reactor performance obtained at 40 °C was 1.15 mW/m{sup 2} maximum power density, 89.1% COD removal and a degradation efficiency of 97.10%; at moderately saline (1% w/v) conditions the maximum power density was 1.06 mW/m{sup 2}, 79.1% COD removal and 91.6% degradation efficiency. This work suggests the possible application of MFC technology in the effective treatment of petroleum hydrocarbons contaminated site and refinery effluents.

  12. Heating a chemical current source which operates at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Mitsumata, T.; Khosikhara, N.

    1983-02-14

    A chamber for catalytic ignition of hydrogen or gasoline is installed in a chemical current source. The isolated heat heats the chemical current source with a low temperature of the environment providing its optimal operational conditions. The fuel is fed into the chamber from a tank or chamber located in the body of the chemical current source.

  13. Salinity data from moored current meter casts in the Northeast Pacific Ocean, Bering Sea, and Gulf of Alaska from 03 October 1984 - 01 May 1988 (NODC Accession 8900056)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity data were collected using moored current meter casts in the North Pacific Ocean, Bering Sea, and Gulf of Alaska from October 3, 1984 to May 1, 1988. Data...

  14. Salinity and sigma-t data from moored current meter and CTD casts in the North Pacific Ocean from 26 August 1979 - 07 June 1982 (NODC Accession 8200146)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity and sigma-t data were collected using moored current meter and CTD casts in the North Pacific Ocean from August 26, 1979 to June 7, 1982. Data were...

  15. Effects of Temperature, Salinity, pH, and Light on Filtering and Grazing Rates of a Calanoid Copepod (Schmackeria dubia

    Directory of Open Access Journals (Sweden)

    Changling Li

    2008-01-01

    Full Text Available Calanoid copepods are key components of the marine food web and the food sources of many larval fishes and planktivores, and grazers of phytoplankton. Understanding the ranges of major environmental variables suitable for their growth is essential to maintain the balance between trophic links and resources protection. In this study, the effects of temperature, salinity, pH, and light intensity on the filtering and grazing rates of a herbivorous copepod (Schmackeria dubia were conducted in several control experiments. Our results indicated that experimental animals grazed normally at water temperatures between 15 and 35°C. The filtering and grazing rates increased by onefold at water temperatures from 15 to 25°C, with a peak at around 30°C. S. dubia fed normally at salinity ranging from 20 to 30 ppt, with significantly low filtering and grazing rates at salinity below 15 ppt and above 35 ppt. The filtering and grazing rates increased as pH increased, peaked at approximately 8.5, and then decreased substantially. Light intensity also displayed an important impact on the filtering and grazing rates. Filtering and grazing rates were high when light intensity was greater than 20 and less than 200 µmol m-2 s-1. S. dubia nearly stopped feeding at low light intensity (less than 20 µmol m-2 s-1.

  16. Stable and unstable thermo -current states of high temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Romanovskii, V; Lavrov, N; Ozhogina, V [Russian Research Center ' Kurchatov Institute' , Moscow 123182 (Russian Federation)], E-mail: vromanovskii@netscape.net

    2008-02-01

    Formation peculiarities of the stable and unstable states of high-T{sub c} superconductors are discussed. To understand the basic physical trends, which are characteristic for the current penetration mechanism in high temperature superconductors, the operating states of Bi2212 slab without stabilizing matrix placed in DC external magnetic fields at low coolant temperature are theoretically investigated. It is proved that the temperature of a high-T{sub c} superconductor is not equals to the coolant temperature before instability onset. Therefore, the voltage-current characteristic of a high-T{sub c} superconductor has only a positive slope during continuous current charging. As a result, it does not allow one to find the boundary between stable and unstable thermo - current states. This peculiarity has to be considered during experiments at which the critical current of high-T{sub c} superconductors is defined.

  17. [Impact of surface temperature and salinity on the recruiting of the pink shrimp Farfantepenaeus duorarum (Decapoda: Penaeidae), in Sonda de Campeche, Gulf of Mexico].

    Science.gov (United States)

    Ramírez-Rodríguez, Mauricio; Arreguín-Sánchez, Francisco; Lluch-Belda, Daniel

    2006-12-01

    We studied the long term effects of two environmental variables, salinity and surface temperature, on the pink shrimp (Farfantepenaeus duorarum) population in the southern Gulf of Mexico, considering the relationship between recruiting and the concurrent shrimp stock depletion of the last two decades. Our data were collected from 1969 to 1991. Recruitment has been clearly declining, particularly in the 1970s, with an accentuated drop since the 1980s. Sea surface temperatures have steadily risen, particularly since 1972. The temperature difference between the mid 1970s and the late 1980s is 0.5 degree C. Salinity decreased throughout the period. From a long term perspective, recruitment is negatively correlated with temperature and positively correlated with salinity. The effects of temperature and salinity are statistically significant, explaining 52 % and 55 % of the variation in recruitment, respectively.

  18. Quality of temperature and salinity data from Argo profiling floats in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Parvathi, V.; Pankajakshan, T.; Rajkumar, M.; Prasannakumar, S.; Muraleedharan, P.M.; Ravichandran, M.; Rao, R.R.; Gopalakrishna, V.V.

    on Argo-SPB could not identify any significant systematic bias/error, except for a single profile (cycle No 48) of float-4900675 In the case of Argo-N, significant error is found in most of the salinity profiles from the float-2900268....

  19. Direct electric current treatment under physiologic saline conditions kills Staphylococcus epidermidis biofilms via electrolytic generation of hypochlorous acid.

    Directory of Open Access Journals (Sweden)

    Elizabeth L Sandvik

    Full Text Available The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability of Staphylococcus epidermidis biofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximate those in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10(th strength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log(10 CFU/cm(2 were observed with the application of direct current at all four levels (0.7 to 1.8 mA/cm(2 both in the presence and absence of ciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those without at the same current levels. When current exposures were repeated without biofilm or organics in the medium, significant generation of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for each current level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm(2 in medium lacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2, and 0 log reduction, respectively. Direct current also killed Pseudomonas aeruginosa biofilms when NaCl was present. Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a main contributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a critical parameter in experimental design if direct current is to be investigated for in vivo medical applications.

  20. Direct electric current treatment under physiologic saline conditions kills Staphylococcus epidermidis biofilms via electrolytic generation of hypochlorous acid.

    Science.gov (United States)

    Sandvik, Elizabeth L; McLeod, Bruce R; Parker, Albert E; Stewart, Philip S

    2013-01-01

    The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability of Staphylococcus epidermidis biofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximate those in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10(th) strength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log(10) CFU/cm(2) were observed with the application of direct current at all four levels (0.7 to 1.8 mA/cm(2)) both in the presence and absence of ciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those without at the same current levels. When current exposures were repeated without biofilm or organics in the medium, significant generation of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for each current level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm(2)) in medium lacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2, and 0 log reduction, respectively. Direct current also killed Pseudomonas aeruginosa biofilms when NaCl was present. Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a main contributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a critical parameter in experimental design if direct current is to be investigated for in vivo medical applications.

  1. Tidal influence on the seasonal variation in current and salinity around Willingdon Island

    Digital Repository Service at National Institute of Oceanography (India)

    Varma, P.U.; Pylee, A.; RamaRaju, V.S.

    varies from 5 ppt at the surface to 25 ppt at the bottom during flood tide. The flood and ebb currents are comparatively high in the Ernakulam channel than in the Mattancherry channel. The ebb currents are strong in the surface layers and the flood...

  2. Influence of seasonal variability of lower Mississippi River discharge, temperature, suspended sediments, and salinity on oil-mineral aggregate formation.

    Science.gov (United States)

    Danchuk, Samantha; Willson, Clinton S

    2011-07-01

    Under certain conditions, oil droplets that have separated from the main oil slick may become coated by suspended sediments forming oil-mineral aggregates (OMAs). The formation of these aggregates depends on suspended particulate characteristics, temperature, salinity, mixing energy, droplet size and number, and oil properties. The OMAs do not re-coalesce with the slick and tend not to adhere to surfaces, potentially evading surface cleanup measures, enhancing opportunity for biodegradation and reducing shoreline oiling. Potential OMA formation was quantified during four distinct states of the Lower Mississippi River during a typical year using empirical relationships from laboratory and field studies for three common oils and different combinations of discharge, temperature, suspended sediments, and salinity. The largest potential OMA formation for the two lighter oils, up to 36% of the total release volume, was in the winter and spring, when high sediment availability promotes formation. For the denser, high-viscosity oil, the peak potential OMA formation, 9% of the release volume, occurred in the summer, when the salinity was higher. These results provide some evidence that, depending on environmental and spill characteristics, the formation of OMAs could be an important, but unaccounted for, process in the fate and transport of oils released in the Lower Mississippi River and should be included in oil spill dispersion models and post-spill site assessment and remediation actions.

  3. Effect of salinity and temperature on the adsorption of Hg(II) from aqueous solutions by a Ca-montmorillonite.

    Science.gov (United States)

    Green-Ruiz, C

    2009-01-01

    Use of clay minerals for removing mercury is an effective technology for the treatment of industrial wastewaters and can become an effective tool for the remediation of coastal ecosystems polluted with this metal. Calcic montmorillonite was employed for adsorbing Hg(II) ions from aqueous solutions at different conditions of salinity (0, 20 and 35 g NaCl L(-1)), temperature (15, 25 and 35 degrees C), and initial concentrations (0.25, 0.50, 1.00, 2.50, 5.00 and 10.00 mg Hg L(-1)). It was observed that 0.4 g dry weight of montmorillonite removed from 0.02 mg g(-1) (at 0.25 mg L(-1) of Hg(II)) to 0.68 mg g(-1) (at 10.0 mg L(-1) of Hg(II)) at 25 degrees C, salinity of 0 g NaCl L(-1) and pH of 6. The initial concentration of Hg(II) and salinity had an effect on the behaviour of the adsorption process, which was temperature independent. The data fit well the Freundlich adsorption isotherm, indicating that heterogeneous conditions prevail in this process.

  4. Multistable current states in high-temperature superconducting composites

    Science.gov (United States)

    Romanovskii, V. R.

    2016-09-01

    Conditions for current instabilities that arise in high-temperature superconducting composites with essentially nonlinear dependences of the critical current densities and resistivity on the temperature and magnetic induction have been studied. The analysis has been conducted in terms of zero-dimensional models, which has made it possible to formulate general physical mechanisms behind the formation of currents states in superconducting composites according to the external magnetic field induction, cooling conditions, and the properties of the superconductor and cladding. The possible existence of current and temperature stable steps, as well as stable steps of the electric field strength, in the absence of the superconducting-normal transition, has been demonstrated. Reasons for instabilities under multistable current states have been discussed.

  5. New insights into saline water evaporation from porous media: Complex interaction between evaporation rates, precipitation, and surface temperature

    Science.gov (United States)

    Shokri-Kuehni, Salomé M. S.; Vetter, Thomas; Webb, Colin; Shokri, Nima

    2017-06-01

    Understanding salt transport and deposition patterns during evaporation from porous media is important in many engineering and hydrological processes such as soil salinization, ecosystem functioning, and land-atmosphere interaction. As evaporation proceeds, salt concentration increases until it exceeds solubility limits, locally, and crystals precipitate. The interplay between transport processes, crystallization, and evaporation influences where crystallization occurs. During early stages, the precipitated salt creates an evolving porous structure affecting the evaporation kinetics. We conducted a comprehensive series of experiments to investigate how the salt concentration and precipitation influence evaporation dynamics. Our results illustrate the contribution of the evolving salt crust to the evaporative mass losses. High-resolution thermal imaging enabled us to investigate the complex temperature dynamics at the surface of precipitated salt, providing further confirmation of salt crust contribution to the evaporation. We identify different phases of saline water evaporation from porous media with the corresponding dominant mechanisms in each phase and extend the physical understanding of such processes.

  6. The effect of salinity, redox mediators and temperature on anaerobic biodegradation of petroleum hydrocarbons in microbial fuel cells.

    Science.gov (United States)

    Adelaja, Oluwaseun; Keshavarz, Tajalli; Kyazze, Godfrey

    2015-01-01

    Microbial fuel cells (MFCs) need to be robust if they are to be applied in the field for bioremediation. This study investigated the effect of temperature (20-50°C), salinity (0.5-2.5% (w/v) as sodium chloride), the use of redox mediators (riboflavin and anthraquinone-2-sulphonate, AQS) and prolonged fed-batch operation (60 days) on biodegradation of a petroleum hydrocarbon mix (i.e. phenanthrene and benzene) in MFCs. The performance criteria were degradation efficiency, % COD removal and electrochemical performance. Good electrochemical and degradation performance were maintained up to a salinity of 1.5% (w/v) but deteriorated by 35-fold and 4-fold respectively as salinity was raised to 2.5%w/v. Degradation rates and maximum power density were both improved by approximately 2-fold at 40°C compared to MFC performance at 30°C but decreased sharply by 4-fold when operating temperature was raised to 50°C. The optimum reactor performance obtained at 40°C was 1.15 mW/m(2) maximum power density, 89.1% COD removal and a degradation efficiency of 97.10%; at moderately saline (1% w/v) conditions the maximum power density was 1.06 mW/m(2), 79.1% COD removal and 91.6% degradation efficiency. This work suggests the possible application of MFC technology in the effective treatment of petroleum hydrocarbons contaminated site and refinery effluents.

  7. Survival, growth and reproduction of non-indigenous Nile tilapia, Oreochromis niloticus (Linnaeus 1758). I. Physiological capabilities in various temperatures and salinities

    Science.gov (United States)

    Schofield, Pamela J.; Peterson, Mark S.; Lowe, Michael R.; Brown-Peterson, Nancy J.; Slack, William T.

    2011-01-01

    The physiological tolerances of non-native fishes is an integral component of assessing potential invasive risk. Salinity and temperature are environmental variables that limit the spread of many non-native fishes. We hypothesised that combinations of temperature and salinity will interact to affect survival, growth, and reproduction of Nile tilapia, Oreochromis niloticus, introduced into Mississippi, USA. Tilapia withstood acute transfer from fresh water up to a salinity of 20 and survived gradual transfer up to 60 at typical summertime (30°C) temperatures. However, cold temperature (14°C) reduced survival of fish in saline waters ≥10 and increased the incidence of disease in freshwater controls. Although fish were able to equilibrate to saline waters in warm temperatures, reproductive parameters were reduced at salinities ≥30. These integrated responses suggest that Nile tilapia can invade coastal areas beyond their point of introduction. However, successful invasion is subject to two caveats: (1) wintertime survival depends on finding thermal refugia, and (2) reproduction is hampered in regions where salinities are ≥30. These data are vital to predicting the invasion of non-native fishes into coastal watersheds. This is particularly important given the predicted changes in coastal landscapes due to global climate change and sea-level rise.

  8. Effect of temperature and salinity on the wastewater treatment performance of aerobic submerged fixed bed biofilm reactors.

    Science.gov (United States)

    Chapanova, G; Jank, M; Schlegel, S; Koeser, H

    2007-01-01

    The influence of temperature (5-35 C) and salinity (up to 20 g/l NaCl) on the wastewater purification process in completely mixed and aerated submerged fixed bed biofilm reactors (SFBBRs) was studied. C- and N-conversion in SFBBRs designed according to the DWA (German Association for Water, Wastewater and Waste) rules for carbon removal was investigated for several months on synthetic wastewater. The DOC degradation rate was even at, according to the DWA, high DOC/BOD loading rates not much affected by temperatures between 5-35 degrees C and salt contents up to 20 g/L NaCl. At these high DOC loadings an appreciable ammonium conversion could also be observed. The ammonium conversion proved to be sensitive to temperature and salinity. At 5 degrees C the ammonium removal rate decreased by a factor of five compared to 25-35 degrees C. Under many operation conditions investigated more than 50% of the converted ammonium was transformed into gaseous nitrogen. The addition of 20 g/L NaCl caused a strong inhibition of the ammonium removal rate over the whole temperature range investigated.

  9. Transmission Level High Temperature Superconducting Fault Current Limiter

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Gary [SuperPower, Inc., Schenectady, NY (United States)

    2016-10-05

    The primary objective of this project was to demonstrate the feasibility and reliability of utilizing high temperature superconducting (HTS) materials in a Transmission Level Superconducting Fault Current Limiter (SFCL) application. During the project, the type of high temperature superconducting material used evolved from 1st generation (1G) BSCCO-2212 melt cast bulk high temperature superconductors to 2nd generation (2G) YBCO based high temperature superconducting tape. The SFCL employed SuperPower's “Matrix” technology that offers modular features to enable scale up to transmission voltage levels. The SFCL consists of individual modules that contain elements and parallel inductors that assist in carrying the current during the fault. A number of these modules are arranged in an m x n array to form the current limiting matrix.

  10. Transmission Level High Temperature Superconducting Fault Current Limiter

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Gary [SuperPower, Inc., Schenectady, NY (United States)

    2016-10-05

    The primary objective of this project was to demonstrate the feasibility and reliability of utilizing high-temperature superconducting (HTS) materials in a Transmission Level Superconducting Fault Current Limiter (SFCL) application. During the project, the type of high-temperature superconducting material used evolved from 1st generation (1G) BSCCO-2212 melt cast bulk high-temperature superconductors to 2nd generation (2G) YBCO-based high-temperature superconducting tape. The SFCL employed SuperPower's “Matrix” technology, that offers modular features to enable scale up to transmission voltage levels. The SFCL consists of individual modules that contain elements and parallel inductors that assist in carrying the current during the fault. A number of these modules are arranged in an m x n array to form the current-limiting matrix.

  11. A salinity front and current rip near Cape Hatteras, North Carolina

    Science.gov (United States)

    Marmorino, G. O.; Trump, C. L.

    1994-04-01

    Shipboard hydrographic and acoustic Doppler current profiler data collected in September 1991 show a shallow front separating brackish coastal water from denser Gulf Stream water advancing onto the continental shelf near Cape Hatteras. The surface expression of the front has the hallmarks of a current rip: a corrugated line of flotsam (indicating surface convergence) and an adjoining band of short, steep waves (indicating wave-current interaction). Sinking flow of 15 cm/s and a 10-dB change in acoustic backscatter strength occur over a cross-front distance of 10-20 m. While northward surface currents in the Gulf Stream water move at about 60 cm/s, the front advects northward at only 35 cm/s; this difference implies frontal propagation to the south relative to the deeper fluid at a speed consistent with theoretical expectations. The surface convergence across the front is estimated to be about 50 cm/s, and the horizontal surface strain rate is estimated to be 0.025-0.05 s-1. This supports the large strain rate needed by Jansen et al. (1993) to simulate the O(10 dB) radar modulations measured at the rip by Askari (1992). Similar current rips may account for curvilinear high-backscatter features appearing in historical synthetic aperture radar images of the shelf area north of Cape Hatteras.

  12. Temperature and salinity data from moored seacat sensors of the Multi-disciplinary Ocean Sensors for Environmental Analyses and Networks (MOSEAN) project 2004-2007 (NODC Accession 0115703)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity data were collected by seacat sensors from seven deployments within 2004-2007 on the HALE-ALOHA mooring, a location about 100 km north of...

  13. Oceanographic profile temperature, salinity, oxygen and other measurement collected using bottle in the Barents, Kara, Laptev, White, Norwegian Seas from 1970 - 1975 (NODC Accession 0002125)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic profile temperature, salinity, oxygen and other measurement collected using bottle in the Barents, Kara, Laptev, White, Norwegian Seas from 1970 - 1975...

  14. Oceanographic profile temperature, salinity, oxygen and other measurement collected using bottle in the Barents, Kara, Laptev, White, Norwegian Seas from 1976 - 1982 (NODC Accession 0002126)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic profile temperature, salinity, oxygen and other measurement collected using bottle in the Barents, Kara, Laptev, White, Norwegian Seas from 1976 - 1982...

  15. Oceanographic profile plankton, temperature, salinity collected using bottle from various unknown small boats in the South Pacific Ocean from 1981 to 1982 (NODC Accession 0002138)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity and other measurements found in dataset OSD taken from unknown platform(s)in the Coastal S Pacific, Equatorial Pacific and other locations...

  16. Oceanographic profile plankton, Temperature Salinity and other measurements collected using bottle from various platforms in the South Pacific Ocean from 1997 to 1998 (NODC Accession 0014651)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, oxygen, nutrients, and other measurements found in the bottle dataset taken from the SNP-1, HUAMANGA (fishing boat) and other platforms in...

  17. Oceanographic profile temperature, salinity and other measurements collected using bottle from the TEMP in the Arctic from 1947 to 1949 (NODC Accession 0001122)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profile data digitized at NODC on 05/02/03, received by Igor Smolyar from the personal library of Dr. Aleksey Zuyev, Murmansk Branch of the...

  18. Profiles of temperature, salinity, and other measurements from CTD, XBT, and bottle samplers received from the Japan Oceanographic Data Center (NODC Accession 0054093)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Profiles of temperature, salinity, and other measurements received from the Japan Oceanographic Data Center, Hydrographic and Oceanographic Department as a...

  19. Identification of thermohaline structure of a tropical estuary and its sensitivity to meteorological disturbance through temperature, salinity, and surface meteorological measurements

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Mehra, P.; Desai, R.G.P.; Sivadas, T.K.; Balachandran, K.K.; Vijaykumar, K.; Revichandran, C.; Agarvadekar, Y.; Francis, R.; Martin, G.D.

    -neap variability in which thermal and haline variability bear an inverse relationship, with cooling and enhanced salinity during spring tide and vice versa during neap tide. The diurnal variability in temperature is controlled by day/night cyclicity rather than...

  20. Historical bottle temperature and salinity data collected globally by multiple platforms from 1868 to 1959, submitted by the German Data Center (BSH) (NODC Accession 0071062)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical bottle temperature and salinity data from the German data center, Bundesamt fur Seeschifffahrt und Hydrographie (BSH) in Hamburg. The data contain...

  1. Oceanographic profile temperature and salinity data using Nansen bottles and MBT aboard the HMS Hydra on 23 August 1972, off the island of New Britain (NODC Accession 0118531)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic profile temperature and salinity data from 5 Nansen bottle casts and 5 Mechanical Bathythermograph (MBT) casts taken by the UK Navy hydrographic...

  2. Oceanographic profile temperature and salinity measurements collected using bottle from the GEORGIY SEDOV in the Arctic from 1937 to 1940 (NODC Accession 0001123)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profile data digitized at NODC on 05/02/03, received by Igor Smolyar from "Timofeev, B.T. 1951. Results of deep-sea observations. In:...

  3. Water temperature and salinity profiles from CTD and XBT casts aboard multiple platforms from 1986-01-09 to 2011-01-29 (NCEI Accession 0103557)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This water temperature and salinity profile data set is a product from the Commonwealth Scientific and Industrial Research Organization (CSIRO) used to compare...

  4. Oceanographic temperature, salinity, oxygen, transmissivity, and PAR measurements collected using CTD from NOAA Ship McArthur II during 2007 (NCEI Accession 0034511)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic temperature, salinity, oxygen, transmissivity, and PAR measurements collected using CTD from NOAA Ship McArthur II during 2007 as part of PACOOS.

  5. Dissolved oxygen, salinity, temperature, and depth data from bottle casts in the North Atlantic Ocean from 05 February 1973 to 19 August 1980 (NODC Accession 0000289)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Dissolved oxygen, salinity, temperature, and depth data were collected using bottle casts in the North Atlantic Ocean from February 5, 1973 to August 19, 1980. These...

  6. Nutrients, salinity, chemical, and temperature data were collected using bottle and CTD casts in the Norwegian Sea from 19 September 1959 to 23 October 1995 (NODC Accession 0000299)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nutrients, salinity, chemical, and temperature data were collected from the PROFESSOR MULTANOVSKYI, AKADEMIK SHULEYKIN, IVAN PETROV, and OTTO SCHMIDT from September...

  7. Oceanographic profile temperature, salinity, and meteorology measurements collected using MRB from moored buoy in the Tropical Pacific, Tropical Atlantic from 2006 to 2008 (NODC Accession 0043260)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity and other measurements found in dataset MRB in the Equatorial Pacific, Equatorial Atlantic and other locations from 2006 to 2008 as part of the...

  8. Temperature and salinity data from bottle casts from Borno Station Light Vessel from the Baltic Sea from the 08 January 1932 to 30 December 1941 (NCEI Accession 0154388)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity data were collected from bottle casts from Sweden Borno Station Light Vessel from the Baltic Sea. Data were collected from January 8 1932 to...

  9. Oceanographic profile temperature and salinity measurements collected using bottle from the STEFAN MALYGIN and SAMOED in the Arctic in 1931 (NODC Accession 0001090)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and meteorology data received at NODC on 05/02/03 by Igor Smolyar from the personal library of Dr. Aleksey Zuyev, Murmansk Branch of the...

  10. Oceanographic profiles of temperature, salinity, and nutrients measurements collected using bottle in the Atlantic Ocean from the VNIRO institute from 2005-2006 (NCEI Accession 0045650)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic profiles of temperature, salinity, and dissolved inorganic nutrients measurements collected using bottle in the Atlantic Ocean from the VNIRO institute...

  11. Arctic phytoplankton and zooplankton abundance, temperature and salinity measurements collected from multiple platforms from 1903-02-22 to 1970-09-30 (NODC Accession 0069178)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Arctic phytoplankton and zooplankton abundance, temperature and salinity measurements collected from multiple platforms from 1903-02-22 to 1970-09-30 by Zoological...

  12. Oceanographic profile Temperature and Salinity measurements collected using bottle from various platforms in the Arctic Ocean from 1920 to 1934 (NODC Accession 0043759)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity data received at NODC from STATE OCEANOGRAPHIC INSTITUTION; ROSGIDROMET (Moscow) , digitized by the submitting institute as part of the...

  13. Salinity, temperature, and nutrients data from CTD casts in the Mediterranean Sea from 29 January 1970 to 24 February 1970 (NODC Accession 0000363)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity, temperature, nutrients, and other data were collected from the DISCOVERY II from January 29, 1970 to February 24, 1970. Data were submitted by National...

  14. Oceanographic profile temperature and salinity measurements collected using CTD from R/V Hecla in the North Atlantic during 1996 (NODC Accession 0046839)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic profile temperature and salinity measurements collected using CTD from R/V Hecla in the North Atlantic during 1996. Data submitted by Garry Dawson...

  15. Synoptic monthly gridded three dimensional (3D) World Ocean Database temperature and salinity from January 1945 to December 2014 (NCEI Accession 0140938)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The synoptic gridded WOD (SG-WOD) provides 3D world ocean gridded temperature and salinity data in monthly increment from WOD profiles using the Optimal Spectral...

  16. Temperature and salinity measurements taken from the WELLEM; JAN and SCHWABENLAND in the Coastal N Atlantic, North Atlantic and other locations from 1937 to 1939 (NCEI Accession 0002127)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profile data digitized from "Deutsche Antarktisce Expedition 1938/1939, mit dem Flugzeugstutzpunkt der Deutschen Lufthansa A.G.M.S....

  17. Temperature and salinity data from BT casts in the North Atlantic Ocean from 31 July 1984 to 13 February 1991 (NODC Accession 0000322)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and depth data were collected from multiple ships from July 31, 1984 to February 13, 1991. These data were collected using BT casts in the...

  18. Temperature and salinity measurements taken by instrumented elephant seals (SEaOS) from 2004-02-24 to 2007-01-17 (NCEI Accession 0012881)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity measurements taken from elephant seals in the Antarctic, Coastal South Indian Ocean and other locations from 2004 to 2006 (NODC Accession...

  19. Oceanographic profile temperature, salinity, oxygen, and nutrients measurements collected using bottle from the Staffetta in the Mediterranean Sea (NODC Accession 0002243)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, oxygen and other profile data collected in the Mediterranean Sea received at NODC on 07/11/04 by Sydney Levitus from Trieste Institute of...

  20. Temperature and salinity profile data collected by NOAA Ship Rainier and its launches, 2000-04 to 2001-11 (NCEI Accession 0000709)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD data were collected from NOAA Ship Rainer in coastal Alaska/Washington/Oregon from 04 April 2000 to 14 November 2001. Data include temperature and salinity...

  1. Temperature and salinity profile data from CTD casts from NOAA Ship WHITING from 2001-04 to 2001-11 (NODC Accession 0000636)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD data were collected from NOAA Ship WHITING in the NW Atlantic (limit-40) from 05 April 2001 to 15 November 2001. Data include temperature and salinity profiles....

  2. Oceanographic profile temperature, salinity, oxygen, nutrients, and plankton measurements collected using bottle from the Parizeau in the North Pacific Ocean (NODC Accession 0002242)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, oxygen and other profile data received at NODC on 09/09/04 by Sydney Levitus from the Institute of Ocean Sciences (Sidney, B.C.), digitized...

  3. Dissolved oxygen, salinity, and temperature data from bottle casts in the North Atlantic Ocean from 01 December 1974 to 04 November 1984 (NODC Accession 0000284)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Dissolved oxygen, salinity, and temperature data were collected using bottle casts in the North Atlantic Ocean from December 1, 1974 to November 4, 1984. Data were...

  4. Dissolved oxygen, salinity, temperature, and depth data from bottle casts in the North Atlantic Ocean from 07 February 1987 to 18 February 1991 (NODC Accession 0000290)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Dissolved oxygen, salinity, temperature, and depth data were collected using bottle casts in the North Atlantic Ocean from February 7, 1987 to February 18, 1991....

  5. Oceanographic profile temperature, salinity, oxygen measurements collected using bottle from multiple platforms in the Azov, Black Seas from 1924-1990 (NODC Accession 0002717)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic profile temperature, salinity, oxygen measurements collected using bottle from multiple platforms in the Azov, Black Seas from 1924-1990

  6. Dissolved oxygen, salinity, and temperature data from multiple ships using CTD casts in the South Pacific Ocean from 26 March 1985 to 19 December 1997 (NODC Accession 0000286)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Dissolved oxygen, salinity, and temperature data were collected from the ALMIRANTE MONTT, CARLOS PORTE, SANTA MARGARITA II, MELI PULLI, IZISHI MARU, STELLA MARIS,...

  7. Temperature, salinity, and other data from buoy casts in the Arctic Ocean, Barents Sea and Beaufort Sea from 1948 to 1993 (NODC Accession 9800040)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and other data were collected using buoy casts in the Arctic Ocean, Barents Sea and Beaufort Sea from 1948 to 1993. Data were collected by the...

  8. Oceanographic profile temperature, salinity and pressure measurements collected using moored buoy in the Indian Ocean from 2001-2006 (NODC Accession 0002733)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity measurements in the Equatorial Indian from 2001 to 2006 from the TRITON (TRIANGLE TRANS-OCEAN BUOY NETWORK); JAPAN AGENCY FOR MARINE-EARTH...

  9. Temperature and salinity collected for MMS 'Deepwater Program: Northern Gulf of Mexico Continental Slope Habitat and Benthic Ecology' from the Gulf of Mexico, 1999 - 2002 (NODC Accession 0002185)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data collection includes profile data containing temperature and salinity collected in support of this research program to gain better knowledge of the benthic...

  10. Oceanographic profile temperature, salinity, and nutrients measurements collected using bottle, CTD from various platforms in the North West Pacific from 1995-2005 (NODC Accession 0010565)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical and Chemical Oceanographic Time Series (Line-P) containing profiles for Nutrients, temperature, salinity near Ocean Station PAPA (50 deg N;145 deg W)....

  11. Temperature, salinity, sigma_t, pressure measurement collected using CTD from an unknown platform in the Min Fang Bay from 1984 to 1985 (NODC Accession 0048830)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Southern Ocean data - Min Fang Bay , temperature and salinity measurements collected using CTD from unknown platform in the Min Fang Bay from 1984 to 1985

  12. Long term monitoring of currents, conductivity, temperature, salinity, sigma-theta, pressure, waves, chlorophyll A, oxygen, and meteorology from moorings deployed at two locations in Massachusetts Bay from the platforms WHITE HEATH, ASTERIAS, CHRISTOPHER ANDREW, MARCUS HANNA, ABBIE BURGESS, LOONEY, and ARGO MAINE from January 1, 1986 to February 8, 2006 (NODC Accession 0060062)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Measurements of currents and other oceanographic properties were made at two locations to understand the transport and long-term fate of sediments and associated...

  13. A New CMOS Current Reference with High Order Temperature Compensation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new high order CMOS temperature compensated current reference is proposed in this paper, which is accomplished by two first order temperature compensation current references. The novel circuit exploits the temperature characteristics of integrated-circuit resistors and gate-source voltage of MOS transistors working in weak inversion. The proposed circuit, designed with a 0.6 (m standard CMOS technology, gives a good temperature coefficient of 31ppm/℃ [(50~100℃] at a 1.8 V supply, and also achieves line regulation of 0.01%/V and (120 dB PSR at 1 MHz. Comparing with other presented work, the proposed circuit shows better temperature coefficient and Line regulation.

  14. Temperature and current data collected as part of the CLIvar MOde Water Dynamic Experiment (CLIMODE) mooring data from 2005-11 to 2007-11 in the North Atlantic, south-east of the Gulf Stream (NCEI Accession 0127259)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Two years of temperature, salinity, current, and nutrient data were collected on four subsurface moorings as part of a two-year field component of the CLIMODE...

  15. Alternating current calorimetry at very high pressure and low temperature

    CERN Document Server

    Wilhelm, H

    2002-01-01

    The specific heat of CePd sub 2 sub . sub 0 sub 2 Ge sub 1 sub . sub 9 sub 8 has been measured with an ac calorimetric technique up to 22 GPa for temperatures in the range 0.3 K <=T <=10 K. A thermocouple allowed the temperature oscillations to be read when an ac heating current was sent through the sample. The inverse of the thermovoltage V sub a sub c recorded at low temperature exhibits a pronounced anomaly as a function of pressure. It is shown that 1/V sub a sub c extrapolated to zero temperature is a measure of the Sommerfeld coefficient gamma.

  16. Particle image velocimetry measurements and numerical modeling of a saline density current

    CSIR Research Space (South Africa)

    Gerber, G

    2011-03-01

    Full Text Available Particle image velocimetry scalar measurements were carried out on the body of a stably stratified density current with an inlet Reynolds number of 2,300 and bulk Richardson number of 0.1. These measurements allowed the mass and momentum transport...

  17. Photoinduced current and emission induced by current in a nanowire transistor: Temperature dependence

    Indian Academy of Sciences (India)

    Darehdor Mahvash Arabi; Shahtahmassebi Nasser

    2016-03-01

    In this paper, we present a theoretical study on a light emitting and current carrying nanosystem, in the nonzero temperature regime. The system under consideration is a semiconducting nanowire sandwiched between two semi-infinite metallic electrodes. The study was performed using the Keldysh nonequilibrium Green’s function method. We systematically investigate the photoinduced current and the light emission induced by this electronic current in the presence of gate voltage. The temperature dependence of these processes are also investigated in the temperature range of 3–300 K. Our study shows that, the photoinduced current is due to the transfer of electrons from highest occupied molecular orbital (HOMO) to the lowest unoccupied molecularorbital (LUMO). Thus, the separation of electron from the electron–hole pair creates a free electron which is responsible for the observed photoinduced current. The same conclusion is also arrived at for the reverse process of light emission under the influence of the electronic current.

  18. Synergistic Effects of Salinity and Temperature on the Survival of Two Nonnative Bivalve Molluscs, Perna viridis (Linnaeus 1758 and Mytella charruana (d’Orbigny 1846

    Directory of Open Access Journals (Sweden)

    Wei S. Yuan

    2016-01-01

    Full Text Available This study examined the combined salinity and temperature tolerance of two marine bivalve molluscs, Perna viridis and Mytella charruana, which have recently invaded the southeastern United States. It is essential to understand the role that these abiotic variables play in invasions and establishment of nonnative species. We simultaneously explored survival at three salinity ranges (5–9, 20–22.5, and 35–40 ppt in both cold and warm water for juveniles and adults of both species. We determined that Perna viridis can survive at a wide range of temperatures (9–35°C when the salinity is 35–37 ppt; however, as salinity decreased, the thermal survival range for P. viridis became narrower. With M. charruana, our data suggest that juvenile and adult individuals can survive at a wide range of salinities (5–40 ppt at 20°C, but the salinity tolerance range narrowed as the temperature decreased or increased. Additionally, we observed that temperature rapidly impacted survival of P. viridis and M. charruana (within hours, while salinity impacts were more gradual (days to weeks. These data can be used to help predict successful introductions and future expansions of P. viridis and M. charruana in introduced habitats.

  19. Transient analysis and burnout of high temperature superconducting current leads

    Science.gov (United States)

    Seol, S. Y.; Hull, J. R.

    The transient behaviour of high-temperature superconductor (HTS) current leads operated between liquid helium and liquid nitrogen temperatures is analysed for burnout conditions upon transition of the HTS into the normal state. Leads composed of HTS only and of HTS sheathed by pure silver or silver alloy are investigated numerically for temperature-dependent properties and analytically for temperature-independent properties. For lower values of shape factor (current density times length), the lead can be operated indefinitely without burnout. At higher values of shape factor, the lead reaches burnout in a finite time. With high current densities, the leads heat adiabatically. For a fixed shape factor, low current densities are desired to achieve long burnout times. To achieve a low helium boil-off rate in the superconducting state without danger of burnout, there is a preferred temperature dependence for thermal conductivity, and silver alloy sheaths are preferred to pure silver sheaths. However, for a given current density, pure silver sheaths take longer to burn out.

  20. Effect of gender on physiological and behavioural responses of Gammarus roeseli (Crustacea Amphipoda) to salinity and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Sornom, Pascal, E-mail: pascal.sornom@umail.univ-metz.f [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue du General Delestraint, 57070 Metz (France); Felten, Vincent, E-mail: vincent.felten@univ-metz.f [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue du General Delestraint, 57070 Metz (France); Medoc, Vincent, E-mail: medoc@univ-metz.f [Universite de Bourgogne, Laboratoire de Biogeosciences, equipe Ecologie Evolutive, CNRS UMR 5561, 6 Bd Gabriel, 21000 Dijon (France); Sroda, Sophie, E-mail: sophie.sroda@umail.univ-metz.f [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue du General Delestraint, 57070 Metz (France); Rousselle, Philippe, E-mail: rousselle@univ-metz.f [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue du General Delestraint, 57070 Metz (France); Beisel, Jean-Nicolas, E-mail: beisel@sciences.univ-metz.f [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue du General Delestraint, 57070 Metz (France)

    2010-05-15

    The importance of potentially interacting factors in organisms responses to a stress are often ignored or underestimated in ecotoxicology. In laboratory experiments we investigated how gender, temperature and age influence the behaviour and the physiology of the freshwater amphipod Gammarus roeseli under salinity stress. Our results revealed a significant higher sensitivity of females in survival, ventilation and ionoregulation whereas no inter-age differences were reported. Water temperature also exerted a significant effect in survival and ventilation of G. roeseli. Some of those factors appeared to interact significantly. This study provides evidence that gender can affect organisms responses to a stressor and consequently has to be considered while assessing a stress impact. We discussed the potential relationships between biological and behavioural responses. - Influence of gender, age and temperature in a gammarid responses to a stress.

  1. Assessment of crude oil biodegradation in arctic seashore sediments: effects of temperature, salinity, and crude oil concentration.

    Science.gov (United States)

    Sharma, Priyamvada; Schiewer, Silke

    2016-08-01

    The expected increase in offshore oil exploration and production in the Arctic may lead to crude oil spills along arctic shorelines. To evaluate the potential effectiveness of bioremediation to treat such spills, oil spill bioremediation in arctic sediments was simulated in laboratory microcosms containing beach sediments from Barrow (Alaska), spiked with North Slope Crude, and incubated at varying temperatures and salinities. Biodegradation was measured via respiration rates (CO2 production); volatilization was quantified by gas chromatography/mass spectrophotometry (GC/MS) analysis of hydrocarbons sorbed to activated carbon, and hydrocarbons remaining in the sediment were quantified by GC/flame ionization detector (FID). Higher temperature leads to increased biodegradation by naturally occurring microorganisms, while the release of volatile organic compounds was similar at both temperatures. Increased salinity had a small positive impact on crude oil removal. At higher crude oil dosages, volatilization increased, however CO2 production did not. While only a small percentage of crude oil was completely biodegraded, a larger percentage was volatilized within 6-9 weeks.

  2. Effects of temperature, salinity and feeding frequency on growth and mortality of twaite shad (Alosa fallax larvae

    Directory of Open Access Journals (Sweden)

    Navarro T.

    2014-01-01

    Full Text Available Available knowledge on the ecological requirements of the twaite shad Alosa fallax larvae is limited, restricting the development of effective management and conservation measures for this anadromous clupeid in European rivers. In this study, the effects of water temperature, salinity and feeding frequency on A. fallax larval growth and mortality were evaluated. For a period of ten days after the onset of exogenous feeding, A. fallax larvae exhibited higher survival rates when subjected to salinities of 2.5 g·L-1 and 5 g·L-1, from trials conducted at 0 g·L-1, 2.5 g·L-1, 5 g·L-1, 10 g·L-1, 15 g·L-1, 20 g·L-1. Higher food availability resulted in higher larval growth and survival rates during this period. Water temperature effects on larvae growth and survival was evaluated for a period of three months after hatching. Alosa fallax larvae exhibited higher growth and survival rates when subjected to temperatures of 24 °C and 28 °C, in contrast to trials conducted at 20 °C. These results are compared to other Alosa spp. and considerations on conservation measures are discussed in light of the results.

  3. Cryogenic Test of High Temperature Superconducting Current Leads at Enea

    CERN Document Server

    Ballarino, A; Chambouvet, P; Della Corte, A; Di Zenobio, A; Fiamozzi-Zignani, C; Mayorga, J; Napolitano, M; Turtu, S; Viola, R

    2006-01-01

    The LHC (Large Hadron Collider), the accelerator being constructed on the CERN site, involves the operation of more than 8000 superconducting magnets of various current ratings. Essential elements for the powering of these magnets are the HTS current leads. These devices provide the electrical link between the warm cables from/to the power converter and the low temperature superconducting bus bars bringing the current from/to the cryo-magnets. Thus they operate in a temperature range between room temperature and liquid helium temperature. The operation of the LHC will require more than 1000 HTS current leads operating at currents ranging from 600 A to 13000 A. Cryogenic tests of the series of 13000 A and 6000 A HTS current leads are made at ENEA in the framework of a CERN-ENEA collaboration. This report gives an overview of the experimental set-up built in ENEA. The set-up was designed following the typical criterion of a scientific experiment but it was dimensioned to satisfy the schedule of an i...

  4. Effect of temperature, salinity and biofilm on the zoospores settlement of Enteromorpha flexuosa (Wulfen) J.Agardh

    Digital Repository Service at National Institute of Oceanography (India)

    Imchen, T.

    Journal of Geo-Marine Sciences Vol. 41(4), August 2012, pp 355-358 Effect of temperature, salinity and biofilm on the zoospores settlement of Enteromorpha flexuosa (Wulfen) J.Agardh Temjensangba Imchen CSIR-National Institute.... Glass slide were placed in a 5 cm diameter sterile INDIAN J. MAR. SCI., VOL. 41, NO. 4, AUGUST 2012 356 Petri dish followed by incubation at 25±1oC in dark by adding 2 mL spore suspension (1x104 spores, mL- 1). Incubation was stopped at 0.15, 0...

  5. Effects of snow accumulation on soil temperature and change of salinity in frozen soil from laboratory experiments

    Science.gov (United States)

    Harada, K.; Sato, E.; Ishii, M.; Nemoto, M.; Mochizuki, S.

    2008-12-01

    In order to clarify the effect of snow depth on the ground temperature, snowfalls were occurred on soil samples using an artificial snowfall machine in the laboratory and variations of soil temperatures up to 30cm were measured during snowfall. The snow types used here were dendrites (type A) and sphere (type B). The snow depths on the soil surface were 10cm and 30cm for each snow type, so four deferent experimental results were obtained. At each experiment, two samples with deferent initial volumetric water content were prepared, about 10% and 20%. The initial soil temperature was set to 5°C and temperature in the laboratory was kept at -10°C. Soil temperatures were measured at the depths of 0cm, 10cm, 20cm and 30cm during the snowfall, and continuous measurements were conducted for ten hours after the stop of snowfall. From the experiments, it is confirmed that the soil temperature strongly depended on the depths of snow on the surface, density and water content. The soil sample using the type A with the depth of 30cm snow accumulation had the highest temperature at the surface, followed by the type A with 10cm snow, type B with 30cm snow and type B with 10cm snow. It was also pointed that temperature of the high water content samples showed the high temperature decrease compared with the low water one due to the high heat capacity except for the sample using type A with 10cm snow. Numerical calculation will be needed to explain these results. In addition, another experiment will be carried out to clarify the change of salinity during soil freezing with snow accumulation. The method to measure the salinity of soil is to measure the electrical conductivity of soil and volumetric water content at the same depth. The temperature condition in the cooling bath is ranged between -10 and 5°C and changed in 24 hours. Firstly, the temperature profiles will be measured to detect the frozen front, then measurements will start and discuss the results.

  6. MPPT Technique Based on Current and Temperature Measurements

    Directory of Open Access Journals (Sweden)

    Eduardo Moreira Vicente

    2015-01-01

    Full Text Available This paper presents a new maximum power point tracking (MPPT method based on the measurement of temperature and short-circuit current, in a simple and efficient approach. These measurements, which can precisely define the maximum power point (MPP, have not been used together in other existing techniques. The temperature is measured with a low cost sensor and the solar irradiance is estimated through the relationship of the measured short-circuit current and its reference. Fast tracking speed and stable steady-state operation are advantages of this technique, which presents higher performance when compared to other well-known techniques.

  7. High temperature superconducting current leads for the Large Hadron Collider

    CERN Document Server

    Ballarino, A

    1999-01-01

    The large hadron collider (LHC) will be equipped with about 8000 superconducting magnets. Some 3380 leads will feed the currents ranging from 60 to 13000 A. To reduce the heat inleak into the liquid helium, CERN aims to use high temperature superconducting material for leads having current ratings between 600 and 13000 A. Specifications have been written for 13000 A current leads, incorporating a high temperature superconducting section, for the main of the LHC, and contracts have been placed with several firms for the supply of prototypes for comparative testing. The leads used for feeding locally the 60 and 120 A dipole orbit correctors will be conventional conduction cooledmagnets resistive leads. An optimized lead of variable cross section has been tested, and an integral design has been initiated. This report describes the design status of the current leads for the LHC, emphasizing, for the different solutions, the principle of optimization and the choice of cooling methods. (8 refs).

  8. Sea-surface temperature and salinity product comparison against external in situ data in the Arctic Ocean

    Science.gov (United States)

    Stroh, J. N.; Panteleev, Gleb; Kirillov, Sergey; Makhotin, Mikhail; Shakhova, Natalia

    2015-11-01

    Sea-surface temperature and salinity (SST/S) in the Arctic Ocean (AO) are largely governed by sea-ice and continental runoff rather than evaporation and precipitation as in lower latitude oceans, and global satellite analyses and models which incorporate remotely observed SST/S may be inaccurate in the AO due to lack of direct measurements for calibrating satellite data. For this reason, we are motivated to validate several satellite sea-surface temperature (SST) data products and SST/S models by comparing gridded data in the AO with oceanographic records from 2006 to 2013. Statistical analysis of product-minus-observation differences reveals that the satellite SST products considered have a temperature bias magnitude of less than 0.5°C compared to ship-based CTD measurements, and most of these biases are negative in sign. SST/S models also show an overall negative temperature bias, but no common sign or magnitude of salinity bias against CTD data. Ice tethered profiler (ITP) near-surface data span the seasons of several years, and these measurements reflect a sea-ice dominated region where the ocean surface cannot be remotely observed. Against this data, many of the considered models and products show large errors with detectable seasonal differences in SST bias. Possible sources of these errors are discussed, and two adjustments of product SST on the basis of sea-ice concentration are suggested for reducing bias to within less than 0.01°C of ITP near-surface temperatures.

  9. Peritidal stromatolites at the convergence of groundwater seepage and marine incursion: Patterns of salinity, temperature and nutrient variability

    Science.gov (United States)

    Rishworth, Gavin M.; Perissinotto, Renzo; Bornman, Thomas G.; Lemley, Daniel A.

    2017-03-01

    Living peritidal stromatolites forming at the interface of coastal groundwater seepage and regular marine input are known from only a few locations globally, including South Africa, Western Australia and Northern Ireland. In contrast to modern stromatolites from exclusively fresh or marine waters, which persist due to high calcium carbonate saturation states or hypersaline and erosive conditions (which exclude organisms that might disrupt or out-compete the stromatolite-forming benthic microalgae), the factors supporting stromatolite formation at peritidal locations have not been well-documented. Therefore, the aim of this study was to investigate the fine-scale physico-chemical parameters in terms of pool temperature, salinity and nutrient dynamics at three representative sites along the coastline near Port Elizabeth, South Africa. These parameters were assessed with reference to potential physical, meteorological and ocean drivers using a linear or linear mixed-effects modelling approach. Results demonstrate that nutrient inputs into the pools supporting the majority of stromatolite accretion (barrage pools) are driven by groundwater seepage site-specific properties related to anthropogenic occupation (dissolved inorganic nitrogen; DIN) as well as marine water incursion (dissolved inorganic phosphorus; DIP). Pool temperature is a function of seasonal ambient variability while salinity reflects regular state shifts from fresh to marine conditions, which are related to tidal amplitude and swell height. The regular marine incursions likely promote benthic primary biomass in the phosphorus-limited stromatolite pools, as well as preclude organisms which might otherwise outcompete or disrupt the stromatolite microalgae due to intolerances to extreme ( 1.5 to ≥ 30) salinity variability.

  10. The combined influence of sub-optimal temperature and salinity on the in vitro viability of Perkinsus marinus, a protistan parasite of the eastern oyster Crassostrea virginica

    Science.gov (United States)

    La Peyre, M.K.; Casas, S.M.; Gayle, W.; La Peyre, Jerome F.

    2010-01-01

    Perkinsus marinus is a major cause of mortality in eastern oysters along the Gulf of Mexico and Atlantic coasts. It is also well documented that temperature and salinity are the primary environmental factors affecting P. marinus viability and proliferation. However, little is known about the effects of combined sub-optimal temperatures and salinities on P. marinus viability. This in vitro study examined those effects by acclimating P. marinus at three salinities (7, 15, 25. ppt) to 10 ??C to represent the lowest temperatures generally reached in the Gulf of Mexico, and to 2 ??C to represent the lowest temperatures reached along the mid-Atlantic coasts and by measuring changes in cell viability and density on days 1, 30, 60 and 90 following acclimation. Cell viability and density were also measured in 7. ppt cultures acclimated to each temperature and then transferred to 3.5. ppt. The largest decreases in cell viability occurred only with combined low temperature and salinity, indicating that there is clearly a synergistic effect. The largest decreases in cell viability occurred only with both low temperature and salinity after 30. days (3.5. ppt, 2 ??C: 0% viability), 60. days (3.5. ppt, 10 ??C: 0% viability) and 90. days (7. ppt, 2 ??C: 0.6 ?? 0.7%; 7. ppt, 10 ??C: 0.2 ?? 0.2%). ?? 2010 .

  11. CORA 4.2: A Delayed Mode Validated Temperature and Salinity Dataset Available for Copernicus Marine Service Reanalysis

    Science.gov (United States)

    Tanguy, S.; Gourrion, J.; Reverdin, G. P.

    2016-02-01

    CORA (Coriolis Dataset for ReAnalysis) is a delayed mode validated global temperature and salinity dataset provided by the Coriolis data center. This dataset provides measurements from 1950 to 2014 and is used for the model reanalysis provided by the copernicus marine service (http://marine.copernicus.eu/). Various new datasets have been added to CORA to enhance the ocean data coverage in the 4.2 version. Among them, the french SHOM (Service OceanorapHique de la Marine) have provided more than 3 million original profiles on the period 1950-2009. The delayed mode data validation is based on two sets of tests. Airst, an automatic test set able to detect and flag obvious erroneous measurements. A second set of tests is based on the comparison of measurements with a minimum and a maximum temperature and salinity reference field. A warning is associated to each suspicious profile which is manually checked by an oceanographer. The next objective of CORA is to produce a copernicus CMEMS dataset by merging the best features of the CORA dataset and EN.4 datasets (www.metoffice.gov.uk/)

  12. Online junction temperature measurement using peak gate current

    DEFF Research Database (Denmark)

    Baker, Nick; Munk-Nielsen, Stig; Iannuzzo, Francesco

    2015-01-01

    A new method for junction temperature measurement of MOS-gated power semiconductor switches is presented. The measurement method involves detecting the peak voltage over the external gate resistor of an IGBT or MOSFET during turn-on. This voltage is directly proportional to the peak gate current...

  13. Terahertz pulsed photogenerated current in microdiodes at room temperature

    CERN Document Server

    Ilkov, Marjan; Manolescu, Andrei; Valfells, Agust

    2015-01-01

    Space-charge induced modulation of the diode current under photoemission leads to the formation of beamlets with time delay between formation corresponding to THz frequency. We investigate the effect of electron temperature and internal space-charge forces on the formation and persistence of the beamlets. We find that for low applied electric fields (less than 8MV/m) temperature effects are most important in causing beam degradation, whereas at higher fields intra-beamlet space-charge forces are dominant. The current modulation is most robust when there is only one beamlet present in the diode gap at a time, corresponding to a macroscopic version of the Coulomb blockade. It is shown that a vacuum microdiode can operate quite well as a tunable THz oscillator at room temperature with an applied electric field above 10 MV/m and diode gap on the order of 100 nanometers.

  14. Terahertz pulsed photogenerated current in microdiodes at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ilkov, Marjan; Torfason, Kristinn; Manolescu, Andrei, E-mail: manoles@ru.is; Valfells, Ágúst [School of Science and Engineering, Reykjavik University, Menntavegur 1, IS-101 Reykjavik (Iceland)

    2015-11-16

    Space-charge modulation of the current in a vacuum diode under photoemission leads to the formation of beamlets with time periodicity corresponding to THz frequencies. We investigate the effect of the emitter temperature and internal space-charge forces on the formation and persistence of the beamlets. We find that temperature effects are most important for beam degradation at low values of the applied electric field, whereas at higher fields, intra-beamlet space-charge forces are dominant. The current modulation is most robust when there is only one beamlet present in the diode gap at a time, corresponding to a macroscopic version of the Coulomb blockade. It is shown that a vacuum microdiode can operate quite well as a tunable THz oscillator at room temperature with an applied electric field above 10 MV/m and a diode gap of the order of 100 nm.

  15. Note: Atmospheric point discharge current measurements using a temperature-compensated logarithmic current amplifier

    Science.gov (United States)

    Marlton, G. J.; Harrison, R. G.; Nicoll, K. A.

    2013-06-01

    Measurements of atmospheric corona currents have been made for over 100 years to indicate the atmospheric electric field. Corona currents vary substantially, in polarity and in magnitude. The instrument described here uses a sharp point sensor connected to a temperature compensated bi-polar logarithmic current amplifier. Calibrations over a range of currents from ±10 fA to ±3 μA and across ±20 °C show it has an excellent logarithmic response over six orders of magnitude from 1 pA to 1 μA in both polarities for the range of atmospheric temperatures likely to be encountered in the southern UK. Comparison with atmospheric electric field measurements during disturbed weather confirms that bipolar electric fields induce corona currents of corresponding sign, with magnitudes ˜0.5 μA.

  16. Note: atmospheric point discharge current measurements using a temperature-compensated logarithmic current amplifier.

    Science.gov (United States)

    Marlton, G J; Harrison, R G; Nicoll, K A

    2013-06-01

    Measurements of atmospheric corona currents have been made for over 100 years to indicate the atmospheric electric field. Corona currents vary substantially, in polarity and in magnitude. The instrument described here uses a sharp point sensor connected to a temperature compensated bi-polar logarithmic current amplifier. Calibrations over a range of currents from ±10 fA to ±3 μA and across ±20 °C show it has an excellent logarithmic response over six orders of magnitude from 1 pA to 1 μA in both polarities for the range of atmospheric temperatures likely to be encountered in the southern UK. Comparison with atmospheric electric field measurements during disturbed weather confirms that bipolar electric fields induce corona currents of corresponding sign, with magnitudes ~0.5 μA.

  17. Reconstructing Past Ocean Salinity ((delta)18Owater)

    Energy Technology Data Exchange (ETDEWEB)

    Guilderson, T P; Pak, D K

    2005-11-23

    Temperature and salinity are two of the key properties of ocean water masses. The distribution of these two independent but related characteristics reflects the interplay of incoming solar radiation (insolation) and the uneven distribution of heat loss and gain by the ocean, with that of precipitation, evaporation, and the freezing and melting of ice. Temperature and salinity to a large extent, determine the density of a parcel of water. Small differences in temperature and salinity can increase or decrease the density of a water parcel, which can lead to convection. Once removed from the surface of the ocean where 'local' changes in temperature and salinity can occur, the water parcel retains its distinct relationship between (potential) temperature and salinity. We can take advantage of this 'conservative' behavior where changes only occur as a result of mixing processes, to track the movement of water in the deep ocean (Figure 1). The distribution of density in the ocean is directly related to horizontal pressure gradients and thus (geostrophic) ocean currents. During the Quaternary when we have had systematic growth and decay of large land based ice sheets, salinity has had to change. A quick scaling argument following that of Broecker and Peng [1982] is: the modern ocean has a mean salinity of 34.7 psu and is on average 3500m deep. During glacial maxima sea level was on the order of {approx}120m lower than present. Simply scaling the loss of freshwater (3-4%) requires an average increase in salinity a similar percentage or to {approx}35.9psu. Because much of the deep ocean is of similar temperature, small changes in salinity have a large impact on density, yielding a potentially different distribution of water masses and control of the density driven (thermohaline) ocean circulation. It is partly for this reason that reconstructions of past salinity are of interest to paleoceanographers.

  18. Change in coccolith size and morphology due to response to temperature and salinity in coccolithophore Emiliania huxleyi (Haptophyta) isolated from the Bering and Chukchi seas

    Science.gov (United States)

    Saruwatari, Kazuko; Satoh, Manami; Harada, Naomi; Suzuki, Iwane; Shiraiwa, Yoshihiro

    2016-05-01

    Strains of the coccolithophore Emiliania huxleyi (Haptophyta) collected from the subarctic North Pacific and Arctic oceans in 2010 were established as clone cultures and have been maintained in the laboratory at 15 °C and 32 ‰ salinity. To study the physiological responses of coccolith formation to changes in temperature and salinity, growth experiments and morphometric investigations were performed on two strains, namely MR57N isolated from the northern Bering Sea and MR70N at the Chukchi Sea. This is the first report of a detailed morphometric and morphological investigation of Arctic Ocean coccolithophore strains. The specific growth rates at the logarithmic growth phases in both strains markedly increased as temperature was elevated from 5 to 20 °C, although coccolith productivity (estimated as the percentage of calcified cells) was similar at 10-20 % at all temperatures. On the other hand, the specific growth rate of MR70N was affected less by changes in salinity in the range 26-35 ‰, but the proportion of calcified cells decreased at high and low salinities. According to scanning electron microscopy (SEM) observations, coccolith morphotypes can be categorized into Type B/C on the basis of their biometrical parameters. The central area elements of coccoliths varied from thin lath type to well-calcified lath type when temperature was increased or salinity was decreased, and coccolith size decreased simultaneously. Coccolithophore cell size also decreased with increasing temperature, although the variation in cell size was slightly greater at the lower salinity level. This indicates that subarctic and arctic coccolithophore strains can survive in a wide range of seawater temperatures and at lower salinities with change in their morphology. Because all coccolith biometric parameters followed the scaling law, the decrease in coccolith size was caused simply by the reduced calcification. Taken together, our results suggest that calcification productivity may

  19. Atmospheric point discharge current measurements using a\\ud temperature-compensated logarithmic current amplifier

    OpenAIRE

    Marlton, Graeme; Harrison, R. Giles; Nicoll, Keri A.

    2013-01-01

    Measurements of atmospheric corona currents have been made for over 100 years to indicate the atmospheric electric field. Corona currents vary substantially, in polarity and in magnitude. The instrument described here uses a sharp point sensor connected to a temperature compensated bi-polar\\ud logarithmic current amplifier. Calibrations over a range of currents from ±10 fA to ±3 μA and across ±20 ◦C show it has an excellent logarithmic response over six orders of magnitude from 1 pA to 1 μA i...

  20. Modeling spatial and temporal variations in temperature and salinity during stratification and overturn in Dexter Pit Lake, Tuscarora, Nevada, USA

    Science.gov (United States)

    Balistrieri, L.S.; Tempel, R.N.; Stillings, L.L.; Shevenell, L.A.

    2006-01-01

    This paper examines the seasonal cycling of temperature and salinity in Dexter pit lake in arid northern Nevada, and describes an approach for modeling the physical processes that operate in such systems. The pit lake contains about 596,200 m3 of dilute, near neutral (pHs 6.7-9) water. Profiles of temperature, conductivity, and selected element concentrations were measured almost monthly during 1999 and 2000. In winter (January-March), the pit lake was covered with ice and bottom water was warmer (5.3 ??C) with higher total dissolved solids (0.298 g/L) than overlying water (3.96 ??C and 0.241 g/L), suggesting inflow of warm (11.7 ??C) groundwater with a higher conductivity than the lake (657 versus 126-383 ??S/cm). Seasonal surface inflow due to spring snowmelt resulted in lower conductivity in the surface water (232-247 ??S/cm) relative to deeper water (315-318 ??S/cm). The pit lake was thermally stratified from late spring through early fall, and the water column turned over in late November (2000) or early December (1999). The pit lake is a mixture of inflowing surface water and groundwater that has subsequently been evapoconcentrated in the arid environment. Linear relationships between conductivity and major and some minor (B, Li, Sr, and U) ions indicate conservative mixing for these elements. Similar changes in the elevations of the pit lake surface and nearby groundwater wells during the year suggest that the pit lake is a flow-through system. This observation and geochemical information were used to configure an one-dimensional hydrodynamics model (Dynamic Reservoir Simulation Model or DYRESM) that predicts seasonal changes in temperature and salinity based on the interplay of physical processes, including heating and cooling (solar insolation, long and short wave radiation, latent, and sensible heat), hydrologic flow (inflow and outflow by surface and ground water, pumping, evaporation, and precipitation), and transfers of momentum (wind stirring

  1. Salinization and Saline Environments

    Science.gov (United States)

    Vengosh, A.

    2003-12-01

    One of the most conspicuous phenomena of water-quality degradation, particularly in arid and semi-arid zones, is salinization of water and soil resources. Salinization is a long-term phenomenon, and during the last century many aquifers and river basins have become unsuitable for human consumption owing to high levels of salinity. Future exploitation of thousands of wells in the Middle East and in many other water-scarce regions in the world depends, to a large extent, on the degree and rate of salinization. Moreover, every year a large fraction of agricultural land is salinized and becomes unusable.Salinization is a global environmental phenomenon that affects many different aspects of our life (Williams, 2001a, b): changing the chemical composition of natural water resources (lakes, rivers, and groundwater), degrading the quality of water supply to the domestic and agriculture sectors, contribution to loss of biodiversity, taxonomic replacement by halotolerant species ( Williams, 2001a, b), loss of fertile soil, collapse of agricultural and fishery industries, changing of local climatic conditions, and creating severe health problems (e.g., the Aral Basin). The damage due to salinity in the Colorado River Basin alone, for example, ranges between 500 and 750 million per year and could exceed 1 billion per year if the salinity in the Imperial Dam increases from 700 mg L-1 to 900 mg L-1 (Bureau of Reclamation, 2003, USA). In Australia, accelerating soil salinization has become a massive environmental and economic disaster. Western Australia is "losing an area equal to one football oval an hour" due to spreading salinity ( Murphy, 1999). The annual cost for dryland salinity in Australia is estimated as AU700 million for lost land and AU$130 million for lost production ( Williams et al., 2002). In short, the salinization process has become pervasive.Salinity in water is usually defined by the chloride content (mg L-1) or total dissolved solids content (TDS, mg L-1or g

  2. Characterization of high-current, high-temperature superconductor current lead elements

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, R.C.; Evans, D.J.; Fisher, B.L. [Argonne National Lab., IL (United States); Brockenborough, W.E.; Roberts, P.R.; Rodenbush, A.J. [American Superconductor Corp., Westborough, MA (United States)

    1996-08-01

    The refrigeration loads of current leads for superconducting magnets can be significantly reduced by using high-temperature superconductor (HTS) leads. An HTS conductor type that is well suited for this application is a laminated sintered stack of HTS powder-in-tube (PIT) tapes. The superconducting elements are normally characterized by their manufacturer by measuring critical currents at 77 K in self field. Additional characterization, which correlates electrical performance at 77 K and at lower temperatures with applied magnetic fields, provides the current lead designer and conductor element manufacturer with critical information. For HTS conductor elements comprising a laminated and sintered stack of Bi-2223 PIT tapes having an alloyed Ag sheath, this characterization uses variable applied fields and operating temperatures.

  3. The current status of high temperature superconducting wires

    Science.gov (United States)

    Mikhailov, B. P.; Burkhanov, G. S.

    1991-12-01

    The principal technological difficulties associated with the manufacture of high temperature superconducting (HTSC) wires based on yttrium and lanthanum ceramics are briefly reviewed. It is noted that the superconducting and mechanical properties of HTSC wires or ribbons are largely determined by their microstructure. Particular attention is given to the currently used method of producing HTSC wires whereby the ceramic powder is encased in a pipe shell and then deformed by different methods, such as rolling, drawing, or pressing. The requirements for the shell material are examined, and current densities are presented for HTSC wires produced in shells of copper, silver, aluminum, nickel, stainless steel, and zirconium.

  4. Optimization of high-temperature superconductor current leads

    Science.gov (United States)

    Seol, S. Y.; Hull, J. R.; Chyu, M. C.

    Methods to improve the performance of high-temperature superconducting current leads are analyzed. Designs are considered that are inherently safe from burnup, even if the lead enters the normal state. The effect of a tapered lead that takes advantage of the increase in critical current density with decreasing temperature will decrease helium boiloff by about a factor of two for an area ratio of four. A new concept, in which Ag powder is distributed in increasing concentration from the cold end to the hot end of the lead in sintered YBCO, is shown to have comparable performance to that of leads made with Ag-alloy sheaths. Performance of the best inherently safe designs is about one order of magnitude better than that of optimized nonsuperconducting leads. BSCCO leads with Ag-alloy sheaths show improved performance for Au fractions up to about 3%, after which increases in Au fraction yield negligible performance improvement.

  5. On the persistence and coherence of subpolar sea surface temperature and salinity anomalies associated with the Atlantic multidecadal variability

    Science.gov (United States)

    Zhang, Rong

    2017-08-01

    This study identifies key features associated with the Atlantic multidecadal variability (AMV) in both observations and a fully coupled climate model, e.g., decadal persistence of monthly mean subpolar North Atlantic (NA) sea surface temperature (SST) and salinity (SSS) anomalies, and high coherence at low frequency among subpolar NA SST/SSS, upper ocean heat/salt content, and the Atlantic Meridional Overturning Circulation (AMOC) fingerprint. These key AMV features, which can be used to distinguish the AMV mechanism, cannot be explained by the slab ocean model results or the red noise process but are consistent with the ocean dynamics mechanism. This study also shows that at low frequency, the correlation and regression between net surface heat flux and SST anomalies are key indicators of the relative roles of oceanic versus atmospheric forcing in SST anomalies. The oceanic forcing plays a dominant role in the subpolar NA SST anomalies associated with the AMV.

  6. Salinity and temperature variations reflecting on cellular PCNA, IGF-I and II expressions, body growth and muscle cellularity of a freshwater fish larvae.

    Science.gov (United States)

    Martins, Y S; Melo, R M C; Campos-Junior, P H A; Santos, J C E; Luz, R K; Rizzo, E; Bazzoli, N

    2014-06-01

    The present study assessed the influence of salinity and temperature on body growth and on muscle cellularity of Lophiosilurus alexaxdri vitelinic larvae. Slightly salted environments negatively influenced body growth of freshwater fish larvae and we observed that those conditions notably act as an environmental influencer on muscle growth and on local expression of hypertrophia and hypeplasia markers (IGFs and PCNA). Furthermore, we could see that salinity tolerance for NaCl 4gl(-)(1) diminishes with increasing temperature, evidenced by variation in body and muscle growth, and by irregular morphology of the lateral skeletal muscle of larvae. We saw that an increase of both PCNA and autocrine IGF-II are correlated to an increase in fibre numbers and fibre diameter as the temperature increases and salinity diminishes. On the other hand, autocrine IGF-I follows the opposite way to the other biological parameters assessed, increasing as salinity increases and temperature diminishes, showing that this protein did not participate in muscle cellularity, but participating in molecular/cellular repair. Therefore, slightly salted environments may provide adverse conditions that cause some obstacles to somatic growth of this species, suggesting some osmotic expenditure with a salinity increment. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Low powdered activated carbon concentrations to improve MBR sludge filterability at high salinity and low temperature

    NARCIS (Netherlands)

    Remy, M.J.J.; Temmink, B.G.; Brink, van den P.; Rulkens, W.H.

    2011-01-01

    Previous research has demonstrated that powdered activated carbon (PAC), when applied at very low dosages and long SRTs, reduces membrane fouling in membrane bioreactor (MBRs). This effect was related to stronger flocs which are less sensitive to shear. Low temperature and high salt concentration ar

  8. Sea Surface Salinity : Research Challenges and Opportunities

    Science.gov (United States)

    Halpern, David; Lagerloef, Gary; Font, Jordi

    2012-01-01

    Sea surface salinity (SSS) can be important in regulating sea surface temperature (SST). Two technological breakthrough satellite SSS missions, Aquarius and Soil Moisture and Ocean Salinity (SMOS), are currently producing high-quality SSS data. This paper provides an overview of the importance of SSS for weather and climate applications and describes the Aquarius and SMOS missions. The newness of adequately sampled SSS data prompted a first-time at-sea field campaign devoted to improved understanding of SSS variations.

  9. Current-voltage-temperature characteristics of DNA origami

    Energy Technology Data Exchange (ETDEWEB)

    Bellido, Edson P; Bobadilla, Alfredo D; Rangel, Norma L; Seminario, Jorge M [Department of Chemical Engineering, Texas A and M University, College Station, TX 77843 (United States); Zhong Hong; Norton, Michael L [Department of Chemistry, Marshall University, Huntington, WV 25755 (United States); Sinitskii, Alexander [Department of Chemistry, Rice University, Houston, TX 77005 (United States)

    2009-04-29

    The temperature dependences of the current-voltage characteristics of a sample of triangular DNA origami deposited in a 100 nm gap between platinum electrodes are measured using a probe station. Below 240 K, the sample shows high impedance, similar to that of the substrate. Near room temperature the current shows exponential behavior with respect to the inverse of temperature. Sweep times of 1 s do not yield a steady state; however sweep times of 450 s for the bias voltage secure a steady state. The thermionic emission and hopping conduction models yield similar barriers of {approx}0.7 eV at low voltages. For high voltages, the hopping conduction mechanism yields a barrier of 0.9 eV and the thermionic emission yields 1.1 eV. The experimental data set suggests that the dominant conduction mechanism is hopping in the range 280-320 K. The results are consistent with theoretical and experimental estimates of the barrier for related molecules.

  10. Effect of CMC on the stability of ZnO nanofluid at high temperature and salinity

    Science.gov (United States)

    Adil, Muhammad; Zaid, Hasnah Mohd; Chuan, Lee Kean; Latiff, Noor Rasyada Ahmad

    2016-11-01

    In this research, the critical micellar concentration (CMC) of different anionic surfactants was determined by employing the UV-Vis spectroscopic technique. The CMC is crucial to evaluate the adsorption of anionic surfactant on a surface of charged metal oxide (i.e. zinc oxide), to prepare a stable nanofluid for different applications including enahced oil recovery (EOR). Three anionic surfactants (sodium dodecyl sulfate, sodium dodecylbenzenesulfonate and oleic acid) were studied in this research. The amount of CMC was determined in the deionized water and brine solution, using the values from the data extracted from the graph between absorbance and concentration of surfactants. A comparative study was also conducted based on CMC results that shows a good agreement between the present research and the literature. In addition, the effect of temperature on CMC value was also examined which provide a better stability of ZnO nanofluid in the high-temperature environment. The overall result reveals that with an addition of salt to the anionic surfactant, repulsive force increases which lead to a decrease in the CMC value. Whereas with the increase in temperature the free energy of the system is affected the result in an additional decline in CMC. However, this decrease is higher in a case of SDS and relatively lower in the case of SDBS and oleic acid. These results suggest that CMC play a significant role to tailor a stable dispersion, to match the conditions of the corresponding application.

  11. Ekstremaľnye izmeneniya temperatury i solenosti vody arkticheskogo poverkhnostnogo sloya v 2007-2009 gg. (The extreme changes of temperature and salinity in the Arctic Ocean surface layer in 2007-2009, in Russian)

    OpenAIRE

    Timokhov, Leonid A.; Ashik, I. M.; Karpy, V. Yu.; Kassens, Heidemarie; Kirillov, Sergey A.; Polyakov, Igor V; Sokolov, V. T.; Frolov, I. Ye.; Chernyavskaya, Ekaterina A.

    2011-01-01

    This paper examines the temperature and salinity patterns and evolution in the surface layer of the Arctic Ocean in 2007-2009 and deals with the factors impacting the extreme changes both in temperature and salinity in 2007. The large areas of positive and negative anomalies in temperature and salinity have been formed over the Arctic Ocean with the apparant frontal barrier areea between Eurasian and American basins. The followed years (2008-2009) exhibit the reducing of thermohaline anomalie...

  12. Design of a Programmable Gain, Temperature Compensated Current-Input Current-Output CMOS Logarithmic Amplifier.

    Science.gov (United States)

    Ming Gu; Chakrabartty, Shantanu

    2014-06-01

    This paper presents the design of a programmable gain, temperature compensated, current-mode CMOS logarithmic amplifier that can be used for biomedical signal processing. Unlike conventional logarithmic amplifiers that use a transimpedance technique to generate a voltage signal as a logarithmic function of the input current, the proposed approach directly produces a current output as a logarithmic function of the input current. Also, unlike a conventional transimpedance amplifier the gain of the proposed logarithmic amplifier can be programmed using floating-gate trimming circuits. The synthesis of the proposed circuit is based on the Hart's extended translinear principle which involves embedding a floating-voltage source and a linear resistive element within a translinear loop. Temperature compensation is then achieved using a translinear-based resistive cancelation technique. Measured results from prototypes fabricated in a 0.5 μm CMOS process show that the amplifier has an input dynamic range of 120 dB and a temperature sensitivity of 230 ppm/°C (27 °C- 57°C), while consuming less than 100 nW of power.

  13. A Kinetic and Factorial Approach to Study the Effects of Temperature and Salinity on Growth and Toxin Production by the Dinoflagellate Alexandrium ostenfeldii from the Baltic Sea

    Science.gov (United States)

    Salgado, Pablo; Vázquez, José A.; Riobó, Pilar; Franco, José M.; Figueroa, Rosa I.; Kremp, Anke; Bravo, Isabel

    2015-01-01

    Alexandrium ostenfeldii is present in a wide variety of environments in coastal areas worldwide and is the only dinoflagellate known species that produces paralytic shellfish poisoning (PSP) toxins and two types of cyclic imines, spirolides (SPXs) and gymnodimines (GYMs). The increasing frequency of A. ostenfeldii blooms in the Baltic Sea has been attributed to the warming water in this region. To learn more about the optimal environmental conditions favoring the proliferation of A. ostenfeldii and its complex toxicity, the effects of temperature and salinity on the kinetics of both the growth and the net toxin production of this species were examined using a factorial design and a response-surface analysis (RSA). The results showed that the growth of Baltic A. ostenfeldii occurs over a wide range of temperatures and salinities (12.5–25.5°C and 5–21, respectively), with optimal growth conditions achieved at a temperature of 25.5°C and a salinity of 11.2. Together with the finding that a salinity > 21 was the only growth-limiting factor detected for this strain, this study provides important insights into the autecology and population distribution of this species in the Baltic Sea. The presence of PSP toxins, including gonyautoxin (GTX)-3, GTX-2, and saxitoxin (STX), and GYMs (GYM-A and GYM-B/-C analogues) was detected under all temperature and salinity conditions tested and in the majority of the cases was concomitant with both the exponential growth and stationary phases of the dinoflagellate’s growth cycle. Toxin concentrations were maximal at temperatures and salinities of 20.9°C and 17 for the GYM-A analogue and > 19°C and 15 for PSP toxins, respectively. The ecological implications of the optimal conditions for growth and toxin production of A. ostenfeldii in the Baltic Sea are discussed. PMID:26636674

  14. High temperature solar furnace: current applications and future potential

    Energy Technology Data Exchange (ETDEWEB)

    Bjorndalen, N. [Dalhousie Univ., Faculty of Engineering, Halifax, NS (Canada)

    2003-02-15

    The high temperature solar furnace can offer great opportunities for the production of many types of products worldwide, but recent advances in this technology have been limited to metal reduction. The production of semiconductors, which are utilized to a great extent in the electronic industry, is a viable option for this technology that has been overlooked. Especially where sand and sunlight are plentiful (countries that surround the equator), silicon chips produced with a solar furnace can have great economical value. This paper describes current and potential solar furnace technologies. The components of the solar furnace are described, as well as metal reduction processes including zinc and aluminum production. The viability of silicon chip production is also examined. The possibilities for other product development using an extremely (up to 10,000 deg C) high temperature solar furnace are also discussed. Economically, the benefits of solar furnaces are great, with only high initial start-up costs and little operation costs. Metal reduction processes can also be enhanced with high temperature solar furnaces in that plugging problems are eliminated. By replacing conventional furnaces, such as blast and electric arc furnaces, with a high temperature solar furnace, CO{sub 2} emissions and energy consumption can be greatly reduced, which will bring in added dividends to the society. (Author)

  15. Sympatric spawning but allopatric distribution of Anguilla japonica and Anguilla marmorata: temperature- and oceanic current-dependent sieving.

    Directory of Open Access Journals (Sweden)

    Yu-San Han

    Full Text Available Anguilla japonica and Anguilla marmorata share overlapping spawning sites, similar drifting routes, and comparable larval durations. However, they exhibit allopatric geographical distributions in East Asia. To clarify this ecological discrepancy, glass eels from estuaries in Taiwan, the Philippines, Indonesia, and China were collected monthly, and the survival rate of A. marmorata under varying water salinities and temperatures was examined. The composition ratio of these 2 eel species showed a significant latitude cline, matching the 24 °C sea surface temperature isotherm in winter. Both species had opposing temperature preferences for recruitment. A. marmorata prefer high water temperatures and die at low water temperatures. In contrast, A. japonica can endure low water temperatures, but their recruitment is inhibited by high water temperatures. Thus, A. japonica glass eels, which mainly spawn in summer, are preferably recruited to Taiwan, China, Korea, and Japan by the Kuroshio and its branch waters in winter. Meanwhile, A. marmorata glass eels, which spawn throughout the year, are mostly screened out in East Asia in areas with low-temperature coastal waters in winter. During summer, the strong northward currents from the South China Sea and Changjiang River discharge markedly block the Kuroshio invasion and thus restrict the approach of A. marmorata glass eels to the coasts of China and Korea. The differences in the preferences of the recruitment temperature for glass eels combined with the availability of oceanic currents shape the real geographic distribution of Anguilla japonica and Anguilla marmorata, making them "temperate" and "tropical" eels, respectively.

  16. Spatial and Temporal Variability of Temperature and Salinity in the Deep and Abyssal Layers of the Subpolar North Atlantic

    Science.gov (United States)

    Yashayaev, I.; Bacon, S.; de Jong, F.; Dye, S.; Fischer, J.; Holliday, N. P.; Kieke, D.; Quadfasel, D. R.; Rhein, M.; Sarafanov, A.; Valdimarsson, H.; van Aken, H. M.

    2010-12-01

    The dense water overflows crossing the Denmark Strait and Faroe-Shetland Channel form the Denmark Strait Overflow Water (DSOW) and Northeast Atlantic Deep Water, respectively. Collectively with the convectively-formed Labrador Sea Water (LSW), these water masses form the deep limb of the Atlantic Meridional Overturning Circulation and hence are important components of the global climate system. Recent variability in the properties of the intermediate and deep water masses will be described by using hydrographic, moored, profiling float, altimeter and tracer data from several programs. We will show that the variability of intermediate-depth water is strongly influenced by the strength and duration of winter convection in the Labrador Sea on the western side, and the advection of warmer more saline intermediate waters from the lower latitudes on the eastern side. Four variations of LSW produced in different years were identified in the 2010 annual survey of the Labrador Sea. While gradually transforming in time, these waters have been preserved in different ranges of density and depth because of gradual weakening of winter convection since 2008, and are still distinguishable by their unique signatures in temperature, salinity and chemical tracers. The fate of each individual LSW class can now be followed by combining profiles from Argo floats and hydrographic data from several institutes. We will show how an international array of hydrographic and tracer sections supported by moored, profiling float and satellite measurements has resolved the downstream propagation of some interesting events formed in the subpolar or Arctic seas. In particular, we document strong fresh and cold anomalies in DSOW, first observed in the Irminger Sea in 1999, 2004 and 2009, and then with a year delay in the abyssal Labrador Sea.

  17. Transcriptomic Analysis of Metabolic Pathways in Milkfish That Respond to Salinity and Temperature Changes.

    Science.gov (United States)

    Hu, Yau-Chung; Kang, Chao-Kai; Tang, Cheng-Hao; Lee, Tsung-Han

    2015-01-01

    Milkfish (Chanos chanos), an important marine aquaculture species in southern Taiwan, show considerable euryhalinity but have low tolerance to sudden drops in water temperatures in winter. Here, we used high throughput next-generation sequencing (NGS) to identify molecular and biological processes involved in the responses to environmental changes. Preliminary tests revealed that seawater (SW)-acclimated milkfish tolerated lower temperatures than the fresh water (FW)-acclimated group. Although FW- and SW-acclimated milkfish have different levels of tolerance for hypothermal stress, to date, the molecular physiological basis of this difference has not been elucidated. Here, we performed a next-generation sequence analysis of mRNAs from four groups of milkfish. We obtained 29669 unigenes with an average length of approximately 1936 base pairs. Gene ontology (GO) analysis was performed after gene annotation. A large number of genes for molecular regulation were identified through a transcriptomic comparison in a KEGG analysis. Basal metabolic pathways involved in hypothermal tolerance, such as glycolysis, fatty acid metabolism, amino acid catabolism and oxidative phosphorylation, were analyzed using PathVisio and Cytoscape software. Our results indicate that in response to hypothermal stress, genes for oxidative phosphorylation, e.g., succinate dehydrogenase, were more highly up-regulated in SW than FW fish. Moreover, SW and FW milkfish used different strategies when exposed to hypothermal stress: SW milkfish up-regulated oxidative phosphorylation and catabolism genes to produce more energy budget, whereas FW milkfish down-regulated genes related to basal metabolism to reduce energy loss.

  18. Current developments in arbuscular mycorrhizal fungi research and its role in salinity stress alleviation: a biotechnological perspective.

    Science.gov (United States)

    Kumar, Ashwani; Dames, Joanna F; Gupta, Aditi; Sharma, Satyawati; Gilbert, Jack A; Ahmad, Parvaiz

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) form widespread symbiotic associations with 80% of known land plants. They play a major role in plant nutrition, growth, water absorption, nutrient cycling and protection from pathogens, and as a result, contribute to ecosystem processes. Salinity stress conditions undoubtedly limit plant productivity and, therefore, the role of AMF as a biological tool for improving plant salt stress tolerance, is gaining economic importance worldwide. However, this approach requires a better understanding of how plants and AMF intimately interact with each other in saline environments and how this interaction leads to physiological changes in plants. This knowledge is important to develop sustainable strategies for successful utilization of AMF to improve plant health under a variety of stress conditions. Recent advances in the field of molecular biology, "omics" technology and advanced microscopy can provide new insight about these mechanisms of interaction between AMF and plants, as well as other microbes. This review mainly discusses the effect of salinity on AMF and plants, and role of AMF in alleviation of salinity stress including insight on methods for AMF identification. The focus remains on latest advancements in mycorrhizal research that can potentially offer an integrative understanding of the role of AMF in salinity tolerance and sustainable crop production.

  19. Engineering design of a high-temperature superconductor current lead

    Science.gov (United States)

    Niemann, R. C.; Cha, Y. S.; Hull, J. R.; Daugherty, M. A.; Buckles, W. E.

    As part of the US Department of Energy's Superconductivity Pilot Center Program, Argonne National Laboratory and Superconductivity, Inc., are developing high-temperature superconductor (HTS) current leads suitable for application to superconducting magnetic energy storage systems. The principal objective of the development program is to design, construct, and evaluate the performance of HTS current leads suitable for near-term applications. Supporting objectives are to (1) develop performance criteria; (2) develop a detailed design; (3) analyze performance; (4) gain manufacturing experience in the areas of materials and components procurement, fabrication and assembly, quality assurance, and cost; (5) measure performance of critical components and the overall assembly; (6) identify design uncertainties and develop a program for their study; and (7) develop application-acceptance criteria.

  20. The Influence of Environmental Salinity, Temperature, Ionizing Irradiation and Yellow or Silver Stage on Lipid Metabolism in the Gills of the European Eel

    DEFF Research Database (Denmark)

    Hansen, Heinz Johs. Max; Abraham, S.

    1979-01-01

    The influence of temperature on the incorporation of [32P]phosphate and [14C]acetate into gill lipids in vivo depends also on environmental salinity. - 2. Ionizing irradiation (1000 r) results in a relatively enhanced incorporation of [32P]phosphate into phosphatidyl choline and of [14C]acetate i......]acetate into triglycerides and wax esters in vivo. - 3. When gill tissue is removed from the animal and incubated in vitro, a pronounced dependence of lipid metabolism on previous environmental salinity is not observed......The influence of temperature on the incorporation of [32P]phosphate and [14C]acetate into gill lipids in vivo depends also on environmental salinity. - 2. Ionizing irradiation (1000 r) results in a relatively enhanced incorporation of [32P]phosphate into phosphatidyl choline and of [14C...

  1. Drift in ocean currents impacts intergenerational microbial exposure to temperature.

    Science.gov (United States)

    Doblin, Martina A; van Sebille, Erik

    2016-05-17

    Microbes are the foundation of marine ecosystems [Falkowski PG, Fenchel T, Delong EF (2008) Science 320(5879):1034-1039]. Until now, the analytical framework for understanding the implications of ocean warming on microbes has not considered thermal exposure during transport in dynamic seascapes, implying that our current view of change for these critical organisms may be inaccurate. Here we show that upper-ocean microbes experience along-trajectory temperature variability up to 10 °C greater than seasonal fluctuations estimated in a static frame, and that this variability depends strongly on location. These findings demonstrate that drift in ocean currents can increase the thermal exposure of microbes and suggests that microbial populations with broad thermal tolerance will survive transport to distant regions of the ocean and invade new habitats. Our findings also suggest that advection has the capacity to influence microbial community assemblies, such that regions with strong currents and large thermal fluctuations select for communities with greatest plasticity and evolvability, and communities with narrow thermal performance are found where ocean currents are weak or along-trajectory temperature variation is low. Given that fluctuating environments select for individual plasticity in microbial lineages, and that physiological plasticity of ancestors can predict the magnitude of evolutionary responses of subsequent generations to environmental change [Schaum CE, Collins S (2014) Proc Biol Soc 281(1793):20141486], our findings suggest that microbial populations in the sub-Antarctic (∼40°S), North Pacific, and North Atlantic will have the most capacity to adapt to contemporary ocean warming.

  2. Drift in ocean currents impacts intergenerational microbial exposure to temperature

    Science.gov (United States)

    Doblin, Martina A.; van Sebille, Erik

    2016-01-01

    Microbes are the foundation of marine ecosystems [Falkowski PG, Fenchel T, Delong EF (2008) Science 320(5879):1034–1039]. Until now, the analytical framework for understanding the implications of ocean warming on microbes has not considered thermal exposure during transport in dynamic seascapes, implying that our current view of change for these critical organisms may be inaccurate. Here we show that upper-ocean microbes experience along-trajectory temperature variability up to 10 °C greater than seasonal fluctuations estimated in a static frame, and that this variability depends strongly on location. These findings demonstrate that drift in ocean currents can increase the thermal exposure of microbes and suggests that microbial populations with broad thermal tolerance will survive transport to distant regions of the ocean and invade new habitats. Our findings also suggest that advection has the capacity to influence microbial community assemblies, such that regions with strong currents and large thermal fluctuations select for communities with greatest plasticity and evolvability, and communities with narrow thermal performance are found where ocean currents are weak or along-trajectory temperature variation is low. Given that fluctuating environments select for individual plasticity in microbial lineages, and that physiological plasticity of ancestors can predict the magnitude of evolutionary responses of subsequent generations to environmental change [Schaum CE, Collins S (2014) Proc Biol Soc 281(1793):20141486], our findings suggest that microbial populations in the sub-Antarctic (∼40°S), North Pacific, and North Atlantic will have the most capacity to adapt to contemporary ocean warming. PMID:27140608

  3. Transcriptomic Analysis of Metabolic Pathways in Milkfish That Respond to Salinity and Temperature Changes.

    Directory of Open Access Journals (Sweden)

    Yau-Chung Hu

    Full Text Available Milkfish (Chanos chanos, an important marine aquaculture species in southern Taiwan, show considerable euryhalinity but have low tolerance to sudden drops in water temperatures in winter. Here, we used high throughput next-generation sequencing (NGS to identify molecular and biological processes involved in the responses to environmental changes. Preliminary tests revealed that seawater (SW-acclimated milkfish tolerated lower temperatures than the fresh water (FW-acclimated group. Although FW- and SW-acclimated milkfish have different levels of tolerance for hypothermal stress, to date, the molecular physiological basis of this difference has not been elucidated. Here, we performed a next-generation sequence analysis of mRNAs from four groups of milkfish. We obtained 29669 unigenes with an average length of approximately 1936 base pairs. Gene ontology (GO analysis was performed after gene annotation. A large number of genes for molecular regulation were identified through a transcriptomic comparison in a KEGG analysis. Basal metabolic pathways involved in hypothermal tolerance, such as glycolysis, fatty acid metabolism, amino acid catabolism and oxidative phosphorylation, were analyzed using PathVisio and Cytoscape software. Our results indicate that in response to hypothermal stress, genes for oxidative phosphorylation, e.g., succinate dehydrogenase, were more highly up-regulated in SW than FW fish. Moreover, SW and FW milkfish used different strategies when exposed to hypothermal stress: SW milkfish up-regulated oxidative phosphorylation and catabolism genes to produce more energy budget, whereas FW milkfish down-regulated genes related to basal metabolism to reduce energy loss.

  4. Remote forcing of subsurface currents and temperatures near the northern limit of the California Current System

    Science.gov (United States)

    Engida, Zelalem; Monahan, Adam; Ianson, Debby; Thomson, Richard E.

    2016-10-01

    Local and remote wind forcing of upwelling along continental shelves of coastal upwelling regions play key roles in driving biogeochemical fluxes, including vertical net fluxes of carbon and nutrients. These fluxes are responsible for high primary productivity, which in turn supports a lucrative fishery in these regions. However, the relative contributions of local versus remote wind forcing are not well quantified or understood. We present results of coherence analyses between currents at a single mooring site (48.5°N, 126°W) in the northern portion of the California Current System (CalCS) from 1989 to 2008 and coincident time series of North America Regional Reanalysis (NARR) 10 m wind stress within the CalCS (36-54°N, 120-132°W). The two-decade-long current records from the three shallowest depths (35, 100, and 175 m) show a remote response to winds from south as far as 36°N. In contrast, only temperatures at the deepest depth (400 m) show strong coherences with remote winds. Weaker local wind influence is observed in both the currents and 400 m temperatures but is mostly due to the large spatial coherence within the wind field itself. Lack of coherence between distal winds and the 400 m currents suggests that the temperature variations at that depth are driven by vertical motion resulting from poleward travelling coastal trapped waves (CTWs). Understanding the effects of remote forcing in coastal upwelling regions is necessary for determining the occurrence and timing of extreme conditions in coastal oceans, and their subsequent impact on marine ecosystems.

  5. Targeted temperature management: Current evidence and practices in critical care

    Directory of Open Access Journals (Sweden)

    Saurabh Saigal

    2015-01-01

    Full Text Available Targeted temperature management (TTM in today′s modern era, especially in intensive care units represents a promising multifaceted therapy for a variety of conditions. Though hypothermia is being used since Hippocratic era, the renewed interest of late has been since early 21 st century. There have been multiple advancements in this field and varieties of cooling devices are available at present. TTM requires careful titration of its depth, duration and rewarming as it is associated with side-effects. The purpose of this review is to find out the best evidence-based clinical practice criteria of therapeutic hypothermia in critical care settings. TTM is an unique therapeutic modality for salvaging neurological tissue viability in critically ill patients viz. Post-cardiac arrest, traumatic brain injury (TBI, meningitis, acute liver failure and stroke. TTM is standard of care in post-cardiac arrest situations; there has been a lot of controversy of late regarding temperature ranges to be used for the same. In patients with TBI, it reduces intracranial pressure, but has not shown any favorable neurologic outcome. Hypothermia is generally accepted treatment for hypoxic ischemic encephalopathy in newborns. The current available technology to induce and maintain hypothermia allows for precise temperature control. Future studies should focus on optimizing hypothermic treatment to full benefit of our patients and its application in other clinical scenarios.

  6. Reconstructing sea surface temperature, sea surface salinity and partial pressure of carbon dioxide in atmos- phere in the Okinawa Trough during the Holocene and their paleoclimatic implications

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The sediment core DGKS9603 collected from the Okinawa Trough was used as research target. By use of unsaturated index of long-chain alkenone, δ13C of POC and of planktonic foraminifera (G. Sacculifer), the evolutions of sea surface temperature and partial pressure of carbon dioxide in the atmosphere during the Holocene were reconstructed in the Okinawa Trough. And in combination of δ18O of planktonic foraminifera, the relative difference of sea surface salinity during the Holocene was also reconstructed. Consequently, three cooling events (E1-E3) were identified, each of which occurred at 1.7-1.6, 5.1-4.8 and 8.1-7.4 kaBP (cal), respectively. Of the three events, E2 and E3 are globally comparable, their occurrence mechanism would be that the main stream of the Kuroshio Current shifted eastward due to the enhanced circulation of the northeastern Pacific Ocean, which was driven in turn by amplified intensity of sunshine and subsequent enhancement of subtropical high pressure; E1 corresponds to the Small Ice-Age Event occurring between 1550 and 1850AD in China. In the Okinawa Trough, E1 might be also related to the eastward shift of main stream of the Kuroshio current driven by powerful Asia winter monsoon.

  7. The use of salinity contrast for density difference compensation to improve the thermal recovery efficiency in high-temperature aquifer thermal energy storage systems

    NARCIS (Netherlands)

    van Lopik, J.H.; Hartog, N.; Zaadnoordijk, Willem Jan

    2016-01-01

    The efficiency of heat recovery in high-temperature (>60 °C) aquifer thermal energy storage (HT-ATES) systems is limited due to the buoyancy of the injected hot water. This study investigates the potential to improve the efficiency through compensation of the density difference by increased salinity

  8. High-density genetic map and identification of QTLs for responses to temperature and salinity stresses in the model brown alga Ectocarpus

    Science.gov (United States)

    Avia, Komlan; Coelho, Susana M.; Montecinos, Gabriel J.; Cormier, Alexandre; Lerck, Fiona; Mauger, Stéphane; Faugeron, Sylvain; Valero, Myriam; Cock, J. Mark; Boudry, Pierre

    2017-01-01

    Deciphering the genetic architecture of adaptation of brown algae to environmental stresses such as temperature and salinity is of evolutionary as well as of practical interest. The filamentous brown alga Ectocarpus sp. is a model for the brown algae and its genome has been sequenced. As sessile organisms, brown algae need to be capable of resisting the various abiotic stressors that act in the intertidal zone (e.g. osmotic pressure, temperature, salinity, UV radiation) and previous studies have shown that an important proportion of the expressed genes is regulated in response to hyposaline, hypersaline or oxidative stress conditions. Using the double digest RAD sequencing method, we constructed a dense genetic map with 3,588 SNP markers and identified 39 QTLs for growth-related traits and their plasticity under different temperature and salinity conditions (tolerance to high temperature and low salinity). GO enrichment tests within QTL intervals highlighted membrane transport processes such as ion transporters. Our study represents a significant step towards deciphering the genetic basis of adaptation of Ectocarpus sp. to stress conditions and provides a substantial resource to the increasing list of tools generated for the species. PMID:28256542

  9. NCEI-TSG: A Global in situ Sea-surface Salinity and Temperature Database of Thermosalinograph (TSG) Observations

    Science.gov (United States)

    Zhang, H. M.; Wang, Z.; Boyer, T.; Bayler, E. J.; Biddle, M.; Baker-Yeboah, S.; Zhang, Y.

    2016-12-01

    The NOAA National Centers for Environmental Information (NCEI) has constructed a Global Thermosalinograph Database (NCEI-TSG) to facilitate access to these in situ sea-surface salinity and temperature measurements. This database provides a comprehensive set of quality-controlled in situ sea-surface salinity (SSS) and temperature (SST) measurements collected from over 200 vessels during the period 1989 to the present. Compared to other TSG datasets, these data have several advantages. 1) The NCEI-TSG is the world's most complete TSG dataset, containing all data from the different TSG data assembly centers, e.g. Shipboard Automated Meteorological and Oceanographic System (SAMOS), Global Ocean Surface Underway Data (GOSUD) and Atlantic Oceanographic and Meteorological Laboratory (AOML), with more historical data from NCEI's archive to be added. 2) When different versions of a dataset are available, the dataset with the highest resolution is always chosen. 3) All data are converted to a common NetCDF format, employing enhanced metadata, following Attribute Convention for Dataset Discovery (ACDD) and Climate and Forecast (CF) conventions, to increase the overall quality and searchability of both the data and metadata. 4) All data are processed using the same 11-step quality control procedures and criteria and flagged using a two-level flag system to provide a well-organized, uniformly quality-controlled TSG dataset for the user community. The NCEI-TSG, a unique dataset for in situ sea-surface observations, serves as a significant resource for establishing match-ups with satellite SST and SSS observations for validation and comparisons. The NCEI-TSG database will significantly contribute to the in situ component of the NOAA Satellite SSS Quality Monitor (4SQM) project (under development). This dataset facilitates assessments of global SST and SSS variability and the analysis of patterns and trends at various regional and temporal scales, enabling new insights in climate

  10. Brain temperature changes during selective cooling with endovascular intracarotid cold saline infusion: simulation using human data fitted with an integrated mathematical model.

    Science.gov (United States)

    Neimark, Matthew Aaron Harold; Konstas, Angelos Aristeidis; Lee, Leslie; Laine, Andrew Francis; Pile-Spellman, John; Choi, Jae

    2013-03-01

    The feasibility of rapid cerebral hypothermia induction in humans with intracarotid cold saline infusion (ICSI) was investigated using a hybrid approach of jugular venous bulb temperature (JVBT) sampling and mathematical modeling of transient and steady state brain temperature distribution. This study utilized both forward mathematical modeling, in which brain temperatures were predicted based on input saline temperatures, and inverse modeling, where brain temperatures were inferred based on JVBT. Changes in ipsilateral anterior circulation territory temperature (IACT) were estimated in eight patients as a result of 10 min of a cold saline infusion of 33 ml/min. During ICSI, the measured JVBT dropped by 0.76±0.18°C while the modeled JVBT decreased by 0.86±0.18°C. The modeled IACT decreased by 2.1±0.23°C. In the inverse model, IACT decreased by 1.9±0.23°C. The results of this study suggest that mild cerebral hypothermia can be induced rapidly and safely with ICSI in the neuroangiographical setting. The JVBT corrected mathematical model can be used as a non-invasive estimate of transient and steady state cerebral temperature changes.

  11. Effects of temperature, salinity, and irradiance on the growth of harmful algal bloom species Phaeocystis globosa Scherffel (Prymnesiophyceae) isolated from the South China Sea

    Science.gov (United States)

    Xu, Ning; Huang, Bozhu; Hu, Zhangxi; Tang, Yingzhong; Duan, Shunshan; Zhang, Chengwu

    2016-06-01

    Blooms of Phaeocystis globosa have been frequently reported in Chinese coastal waters, causing serious damage to marine ecosystems. To better understand the ecological characteristics of P. globosa in Chinese coastal waters that facilitate its rapid expansion, the effects of temperature, salinity and irradiance on the growth of P. globosa from the South China Sea were examined in the laboratory. The saturating irradiance for the growth of P. globosa (I s) was 60 μmol/(m2•s), which was lower than those of other harmful algal species (70-114 μmol/(m2•s)). A moderate growth rate of 0.22/d was observed at 2 μmol/(m2•s) (the minimum irradiance in the experiment), and photo-inhibition did not occur at 230 μmol/(m2•s) (the maximum irradiance in the experiment). Exposed to 42 different combinations of temperatures (10-31°C) and salinities (10-40) under saturating irradiance, P. globosa exhibited its maximum specific growth rate of 0.80/d at the combinations of 24°C and 35, and 27°C and 40. The optimum growth rates (>0.80/d) were observed at temperatures ranging from 24 to 27°C and salinities from 35 to 40. While P. globosa was able to grow well at temperatures from 20°C to 31°C and salinities from 20 to 40, it could not grow at temperatures lower than 15°C or salinities lower than 15. Factorial analysis revealed that temperature and salinity has similar influences on the growth of this species. This strain of P. globosa not only prefers higher temperatures and higher salinity, but also possesses a flexible nutrient competing strategy, adapted to lower irradiance. Therefore, the P. globosa population from South China Sea should belong to a new ecotype. There is also a potentially high risk of blooms developing in this area throughout the year.

  12. Effects of temperature, salinity, and irradiance on the growth of harmful algal bloom species Phaeocystis globosa Scherffel (Prymnesiophyceae) isolated from the South China Sea

    Science.gov (United States)

    Xu, Ning; Huang, Bozhu; Hu, Zhangxi; Tang, Yingzhong; Duan, Shunshan; Zhang, Chengwu

    2017-05-01

    Blooms of Phaeocystis globosa have been frequently reported in Chinese coastal waters, causing serious damage to marine ecosystems. To better understand the ecological characteristics of P. globosa in Chinese coastal waters that facilitate its rapid expansion, the effects of temperature, salinity and irradiance on the growth of P. globosa from the South China Sea were examined in the laboratory. The saturating irradiance for the growth of P. globosa ( I s) was 60 μmol/(m2•s), which was lower than those of other harmful algal species (70-114 μmol/(m2•s)). A moderate growth rate of 0.22/d was observed at 2 μmol/(m2•s) (the minimum irradiance in the experiment), and photo-inhibition did not occur at 230 μmol/(m2•s) (the maximum irradiance in the experiment). Exposed to 42 different combinations of temperatures (10-31°C) and salinities (10-40) under saturating irradiance, P. globosa exhibited its maximum specific growth rate of 0.80/d at the combinations of 24°C and 35, and 27°C and 40. The optimum growth rates (>0.80/d) were observed at temperatures ranging from 24 to 27°C and salinities from 35 to 40. While P. globosa was able to grow well at temperatures from 20°C to 31°C and salinities from 20 to 40, it could not grow at temperatures lower than 15°C or salinities lower than 15. Factorial analysis revealed that temperature and salinity has similar influences on the growth of this species. This strain of P. globosa not only prefers higher temperatures and higher salinity, but also possesses a flexible nutrient competing strategy, adapted to lower irradiance. Therefore, the P. globosa population from South China Sea should belong to a new ecotype. There is also a potentially high risk of blooms developing in this area throughout the year.

  13. Southern Caribbean Sea temperature and salinity variability since the mid-Holocene from monthly resolved coral records

    Science.gov (United States)

    Felis, Thomas; Giry, Cyril; Kölling, Martin; Scholz, Denis; Wei, Wei; Lohmann, Gerrit; Scheffers, Sander

    2013-04-01

    In the tropical Atlantic, proxy reconstructions of Holocene sea surface temperature and salinity that resolve seasonality and interannual to decadal variability are sparse. However, ocean-atmosphere interactions on these timescales play a critical role for climate extremes such as droughts, floods and hurricanes. Consequently, a better understanding of the natural range of sea surface variability on these timescales is important for projections of future tropical Atlantic climate change. Here we present monthly resolved reconstructions of sea surface temperature (SST) and δ18Oseawater (used as proxy for sea surface salinity, SSS) in the southern Caribbean Sea for snapshots throughout the mid- to late Holocene, derived from Sr/Ca and δ18O analyses of fossil shallow-water corals (Diploria strigosa) from Bonaire (Netherlands Antilles). The corals were dated by the 230Th/U-method and provide a total of ~300 years of record, with individual time windows reaching up to 68 years in length. Our coral records indicate that mid- to late Holocene SST and SSS were characterized by persistent quasi-biennial and prominent interannual to multidecadal variability. However, the amplitude of variability on individual timescales has varied over the last 6200 years. We find that on interannual to multidecadal timescales, warmer conditions were accompanied by more saline conditions at the sea surface, and vice versa. Potential forcing mechanisms of this observed pattern are discussed, including the wind-induced advection of surface waters from the South and the variations in the strength of the Atlantic Meridional Overturning Circulation. Compared to the late Holocene, SST variability on inter- to multidecadal timescales was more pronounced during the mid- Holocene, and accompanied by enhanced SSS variability. Moreover, an increased amplitude of the SSS annual cycle is reconstructed for the mid- Holocene, very likely resulting from increased summer precipitation at that time, which

  14. Data Fusion Between Microwave and Thermal Infrared Radiometer Data and Its Application to Skin Sea Surface Temperature, Wind Speed and Salinity Retrievals

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-03-01

    Full Text Available Method for data fusion between Microwave Scanning Radiometer: MSR and Thermal Infrared Radiometer: TIR derived skin sea surface temperature: SSST, wind speed: WS and salinity is proposed. SSST can be estimated with MSR and TIR radiometer data. Although the contribution ocean depth to MSR and TIR radiometer data are different each other, SSST estimation can be refined through comparisons between MSR and TIR derived SSST. Also WS and salinity can be estimated with MSR data under the condition of the refined SSST. Simulation study results support the idea of the proposed data fusion method.

  15. Change in coccolith morphology by responding to temperature and salinity in coccolithophore Emiliania huxleyi (Haptophyta) isolated from the Bering and Chukchi Seas

    Science.gov (United States)

    Saruwatari, K.; Satoh, M.; Harada, N.; Suzuki, I.; Shiraiwa, Y.

    2015-11-01

    Strains of the coccolithophore Emiliania huxleyi (Haptophyta) collected from the subarctic North Pacific and Arctic Oceans during the R/V MIRAI cruise in 2010 (MR10-05) were established as clone cultures and have been maintained in the laboratory at 15 °C and 32 ‰ salinity. To study the physiological responses of coccolith formation to changes in temperature and salinity, growth experiments and morphometric investigations were performed on two strains of MR57N isolated from the northern Bering Sea (56°58' N, 167°11' W) and MR70N at the Chukchi Sea (69°99' N, 168° W). This is the first report of a detailed morphometric and morphological investigation of Arctic Ocean coccolithophore strains. The specific growth rates at the logarithmic growth phases in both strains markedly increased as temperature was elevated from 5 to 20 °C, although coccolith productivity (the percentage of calcified cells) was similar at 10-20 % at all temperatures. On the other hand, the specific growth rate of strain MR70N was affected less by changes in salinity in the range 26-35 ‰, but the proportion of calcified cells decreased at high and low salinities. According to scanning electron microscopy (SEM) observations, coccolith morphotypes can be categorized into Type B/C on the basis of their biometrical parameters, such as length of the distal shield (LDS), length of the inner central area (LICA), and the thickness of distal shield elements. The central area elements of coccoliths varied from grilled type to closed type when temperature was increased or salinity was decreased, and coccolith size decreased simultaneously. Coccolithophore cell size also decreased with increasing temperature, although the variation in cell size was slightly greater at the lower salinity level. This indicates that subarctic and arctic coccolithophore strains can survive in a wide range of seawater temperatures and at lower salinities due to their marked morphometric adaptation ability. Because all

  16. High-temperature strain measurement techniques: Current developments and challenges

    Science.gov (United States)

    Lemcoe, M. M.

    1992-01-01

    Since 1987, a very substantial amount of R&D has been conducted in an attempt to develop reliable strain sensors for the measurements of structural strains during ground testing and hypersonic flight, at temperatures up to at least 2000 deg F. Much of the effort has been focused on requirements of the NASP Program. This presentation is limited to the current sensor development work and characterization studies carried out within that program. It is basically an assessment as to where we are now and what remains to be done in the way of technical accomplishments to meet the technical challenges posed by the requirements and constraints established for the NASP Program. The approach for meeting those requirements and constraints has been multi-disciplinary in nature. It was recognized early on that no one sensor could meet all these requirements and constraints, largely because of the large temperature range (cryogenic to at least 2000 deg F) and many other factors, including the most challenging requirement that the sensor system be capable of obtaining valid 'first cycle data'. Present candidate alloys for resistance-type strain gages include Fe-Cr-Al and Pd-Cr. Although they have superior properties regarding withstanding very high temperatures, they exhibit large apparent strains that must either be accounted for or cancelled out by various techniques, including the use of a dual-element, half-bridge dummy gage, or electrical compensation networks. A significant effort is being devoted to developing, refining, and evaluating the effectiveness of those techniques over a broad range in temperature and time. In the quest to obtain first-cycle data, ways must be found to eliminate the need to prestabilize or precondition the strain gage, before it is attached to the test article. It should be noted that present NASP constraints do not permit prestabilization of the sensor, in situ. Gages are currently being 'heat treated' during manufacture in both the wire- and foil

  17. Vertical properties of nutrients and oxygen under temperature-salinity structure of the Bering Basin in July 1999

    Institute of Scientific and Technical Information of China (English)

    金明明

    2002-01-01

    The China R/V Xuelong went on the first Arctic scientific cruise, and we obtained 271 hydro-chemical samples from 22 deep-sea stations in the Bering Basin in late July, 1999. Here we describe vertical properties of silicate [Si], dissolved inorganic nitrogen [DIN] or [N] (nitrate plus ammonium plus nitrite), phosphate [P] and oxygen [O2] in seawater under potential temperature-salinity structure. The seasonal stratification in the summer and the water exchanges of the North Pacific Ocean over the Bering Basin resulted in that the four layers of vertical structure with two thermoclines may be found. Vertical [Si] and [N] and [P] profiles show that the nutrients are consumed mainly in ≤50 m and the order of deficient nutrients is [Si] the first, [N] the second and [P] the third. The [N] and [P] increase with depth downward to about 500 m and then both decrease, but the [Si] increases from 150 m to 2000 m or the bottom. In ≥150 m the [O2] decreases, which is related with both [P] and [N] increasing closely. Seawater [N]:[P] ratios are 6-12 in ≤50 m, 10.5-14.3 in 100-150 m and 11.7-15.8 from 300 m to the bottom.

  18. Building a Learning Database for the Neural Network Retrieval of Sea Surface Salinity from SMOS Brightness Temperatures

    CERN Document Server

    Ammar, Adel; Obligis, Estelle; Crépon, Michel; Thiria, Sylvie

    2016-01-01

    This article deals with an important aspect of the neural network retrieval of sea surface salinity (SSS) from SMOS brightness temperatures (TBs). The neural network retrieval method is an empirical approach that offers the possibility of being independent from any theoretical emissivity model, during the in-flight phase. A Previous study [1] has proven that this approach is applicable to all pixels on ocean, by designing a set of neural networks with different inputs. The present study focuses on the choice of the learning database and demonstrates that a judicious distribution of the geophysical parameters allows to markedly reduce the systematic regional biases of the retrieved SSS, which are due to the high noise on the TBs. An equalization of the distribution of the geophysical parameters, followed by a new technique for boosting the learning process, makes the regional biases almost disappear for latitudes between 40{\\deg}S and 40{\\deg}N, while the global standard deviation remains between 0.6 psu (at t...

  19. Experimental evaluation of IGBT junction temperature measurement via peak gate current

    DEFF Research Database (Denmark)

    Baker, Nick; Munk-Nielsen, Stig; Iannuzzo, Francesco

    2015-01-01

    Temperature sensitive electrical parameters allow junction temperature measurements on power semiconductors without modification to module packaging. The peak gate current has recently been proposed for IGBT junction temperature measurement and relies on the temperature dependent resistance of th...

  20. Dynamic ikaite production and dissolution in sea ice – control by temperature, salinity and pCO2 conditions

    Directory of Open Access Journals (Sweden)

    S. Rysgaard

    2013-12-01

    Full Text Available Ikaite is a hydrous calcium carbonate mineral (CaCO3 · 6H2O. It is only found in a metastable state, and decomposes rapidly once removed from near-freezing water. Recently, ikaite crystals have been found in sea ice and it has been suggested that their precipitation may play an important role in air-sea CO2 exchange in ice-covered seas. Little is known, however, of the spatial and temporal dynamics of ikaite in sea ice. Here we present evidence for highly dynamic ikaite precipitation and dissolution in sea ice grown at an out-door pool of the Sea-ice Environmental Research Facility (SERF. During the experiment, ikaite precipitated in sea ice with temperatures below −3 °C, creating three distinct zones of ikaite concentrations: (1 a mm to cm thin surface layer containing frost flowers and brine skim with bulk concentrations of > 2000 μmol kg−1, (2 an internal layer with concentrations of 200–400 μmol kg−1 and (3 a~bottom layer with concentrations of −1. Snowfall events caused the sea ice to warm, dissolving ikaite crystals under acidic conditions. Manual removal of the snow cover allowed the sea ice to cool and brine salinities to increase, resulting in rapid ikaite precipitation. The modeled (FREZCHEM ikaite concentrations were in the same order of magnitude as observations and suggest that ikaite concentration in sea ice increase with decreasing temperatures. Thus, varying snow conditions may play a key role in ikaite precipitation and dissolution in sea ice. This will have implications for CO2 exchange with the atmosphere and ocean.

  1. Involvement of the crustacean hyperglycemic hormone (CHH) in the physiological compensation of the freshwater crayfish Cherax quadricarinatus to low temperature and high salinity stress.

    Science.gov (United States)

    Prymaczok, Natalia C; Pasqualino, Valeria M; Viau, Verónica E; Rodríguez, Enrique M; Medesani, Daniel A

    2016-02-01

    This study was aimed at determining the role of the crustacean hyperglycemic hormone (CHH) in the physiological compensation to both saline and thermal stress, in the freshwater crayfish Cherax quadricarinatus. By determining the expression of the CHH gene in the eyestalk of juvenile crayfish, we found that maximal induction of CHH was induced at high salinity (10 g/L) and low temperature (20 °C). In order to investigate the role of CHH in the physiological compensation to such stressful conditions, recombinant CHH was supplied to stressed animals. CHH-injected crayfish showed increased hemolymphatic levels of glucose, in accordance with a significant utilization of glycogen reserves from the hepatopancreas. Furthermore, CHH administration allowed stressed animals to regulate hemolymphatic sodium and potassium at more constant levels than controls. Taken together, these results suggest a relevant role of CHH in increasing the energy available intended for processes involved in the physiological compensation of C. quadricarinatus to both saline and thermal stress.

  2. Artificial primary marine aerosol production: a laboratory study with varying water temperature, salinity, and succinic acid concentration

    Directory of Open Access Journals (Sweden)

    J. Zábori

    2012-11-01

    Full Text Available Primary marine aerosols are an important component of the climate system, especially in the remote marine environment. With diminishing sea-ice cover, better understanding of the role of sea spray aerosol on climate in the polar regions is required. As for Arctic Ocean water, laboratory experiments with NaCl water confirm that a few degrees change in the water temperature (Tw gives a large change in the number of primary particles. Small particles with a dry diameter between 0.01 μm and 0.25 μm dominate the aerosol number density, but their relative dominance decreases with increasing water temperature from 0 °C where they represent 85–90% of the total aerosol number to 10 °C, where they represent 60–70% of the total aerosol number. This effect is most likely related to a change in physical properties and not to modification of sea water chemistry. A change of salinity between 15 g kg−1 and 35 g kg−1 did not influence the shape of a particle number size distribution. Although the magnitude of the size distribution for a water temperature change between 0 °C and 16 °C changed, the shape did not. An experiment where succinic acid was added to a NaCl water solution showed, that the number concentration of particles with 0.010 μm < Dp < 4.5 μm decreased on average by 10% when the succinic acid concentration in NaCl water at a water temperature of 0 °C was increased from 0 μmol L−1 to 94 μmol L−1. A shift to larger sizes in the particle number size distribution is observed from pure NaCl water to Arctic Ocean water. This is likely a consequence of organics and different inorganic salts present in Arctic Ocean water in addition to the NaCl.

  3. Artificial primary marine aerosol production: a laboratory study with varying water temperature, salinity and succinic acid concentration

    Directory of Open Access Journals (Sweden)

    J. Zábori

    2012-08-01

    Full Text Available Primary marine aerosols are an important component of the climate system, especially in the remote marine environment. With diminishing sea-ice cover, better understanding of the role of sea spray aerosol on climate in the polar regions is required. As for Arctic Ocean water, laboratory experiments with NaCl water confirm that a few degrees change in the water temperature (Tw gives a large change in the number of primary particles. Smaller particles with a dry diameter between 0.01 μm and 0.25 μm dominate the aerosol number density, but their relative dominance decreases with increasing water temperature from 0 °C where they represent 85–90% of the total aerosol number to 60–70% of the total aerosol number at 10 °C water temperature. This effect is most likely related to a change in physical properties and not to modification of sea water chemistry. A change of salinity between 15 g kg−1 and 35 g kg−1 showed no influence on the relative shape of a particle number size distribution, nor did a change in water temperature between 0 °C and 16 °C. An experiment where succinic acid was added to a NaCl water solution showed, that the number concentration of particles with Dp < 0.312 μm decreased by 43% when the succinic acid concentration in NaCl water at Tw = 0 °C was increased from 0 μmol l−1 to 2446 μmol l−1. Different organic constituents and perhaps inorganic substances resulted in a particle number shift towards larger particle sizes, when comparing a size distribution resulting from pure NaCl water to size distributions resulting from Arctic Ocean water and resulting from NaCl water with a succinic acid concentration of 2446 μmol l−1.

  4. High temperature and vapor pressure deficit aggravate architectural effects but ameliorate non-architectural effects of salinity on dry mass production of tomato

    Directory of Open Access Journals (Sweden)

    Tsu-Wei eChen

    2015-10-01

    Full Text Available Tomato (Solanum lycopersicum L. is an important vegetable crop and often cultivated in regions exposed to salinity and high temperatures (HT which change plant architecture, decrease canopy light interception and disturb physiological functions. However, the long-term effects of salinity and HT combination (S+HT on plant growth are still unclear. A dynamic functional-structural plant model (FSPM of tomato was parameterized and evaluated for different levels of S+HT combinations. The evaluated model was used to quantify the contributions of morphological changes (architectural effects and physiological disturbances (non-architectural effects on the reduction of shoot dry mass under S+HT. The model predicted dynamic plant architecturale variables with high accuracy (> 85%, which ensured the reliability of the model analyses. HT enhanced architectural effects but reduced non-architectural effects of salinity on dry mass production. The stronger architectural effects of salinity under HT could not be counterbalanced by the smaller non-architectural effects. Therefore, long-term influences of HT on shoot dry mass under salinity were negative at the whole plant level. Our model analysis highlights the importance of plant architecture at canopy level in studying the plant responses to the environments and shows the merits of dynamic FSPMs as heuristic tools.

  5. The ecological coherence of temperature and salinity tolerance interaction and pigmentation in a non-marine vibrio isolated from Salar de Atacama

    Directory of Open Access Journals (Sweden)

    Karem Gallardo

    2016-12-01

    Full Text Available The occurrence of microorganisms from the Vibrio genus in saline lakes from northern Chile had been evidenced using Numerical Taxonomy decades before and, more recently, by phylogenetic analyses of environmental samples and isolates. Most of the knowledge about this genus came from marine isolates and showed temperature and salinity to be integral agents in shaping the niche of the Vibrio populations. The stress tolerance phenotypes of Vibrio sp. Teb5a1 isolated from Salar de Atacama was investigated. It was able to grow without NaCl and tolerated up to 100 g/L of the salt. Furthermore, it grew between 17° and 49°C (optimum 30°C in the absence of NaCl, and the range was expanded into cold temperature (4-49°C in the presence of the salt. Other additional adaptive strategies were observed in response to the osmotic stress: pigment production, identified as the known antibacterial prodigiosin, swimming and swarming motility and synthesis of a polar flagellum. It is possible to infer that environmental congruence might explain the cellular phenotypes observed in Vibrio sp. considering that coupling between temperature and salinity tolerance, the production of antibacterial agents at higher temperatures, flagellation and motility increase the chance of Vibrio sp. to survive in salty environments with high daily temperature swings and UV radiation.

  6. The effect of temperature and salinity on the physiological rates of the mussel Perna perna (Linnaeus 1758

    Directory of Open Access Journals (Sweden)

    Charrid Resgalla Jr.

    2007-05-01

    Full Text Available The aim of this work was to study the rates of respiration, clearance, excretion and absorption efficiency at different temperature and salinity under laboratory conditions for Perna perna. Results showed variations in physiological rates and in acclimatization capacity which, taken together, enabled to understand its behavior in the environment, as well as to estimate its scope for growth. All experiments were carried out in static conditions, in ten replicas with one mussel by flasks. Perna perna was capable of achieving acclimatization for both clearance and absorption efficiency (15 to 30 ºC, but it achieved only partial acclimatization for respiration and excretion under chronic temperature conditions. The clearance and respiration rates increased twofold as the mussel was submitted to temperature shock, which signified a response to metabolism activity. Acclimatization to salinity was clearly the best developed capability (20 to 40 ‰. Net growth efficiency reduced as the temperature increased, but remained constant in the 20 to 35 ‰ salinity range.O molusco bivalve Perna perna é o Mytilidae de maior tamanho e o mais abundante na costa brasileira. Apresenta uma grande importância sócio-econômica devido ao seu uso na mitilicultura, disponibilizando para o consumo humano uma fonte protéica barata proporcionado pelos sistemas de cultivos costeiros. Entretanto, existe uma carência de estudos fisiológicos da espécie, que poderiam ser úteis na avaliação de novas áreas de cultivo, assim como no monitoramento de ambientes contaminados. Neste trabalho foram realizadas testes fisiológicos para determinar as taxas de respiração, clareamento, excreção e eficiência de absorção em laboratório, sob condições crônicas e agudas, em diferentes temperaturas e salinidades. Desta forma, foi possível determinar as oscilações e a capacidade de aclimatação da espécie que servem como base para o entendimento do organismo no

  7. Laboratory Study on the Potential EOR Use of HPAM/VES Hybrid in High-Temperature and High-Salinity Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Dingwei Zhu

    2013-01-01

    Full Text Available Polymer flooding represents one of the most efficient processes to enhance oil recovery, and partially hydrolyzed polyacrylamide (HPAM is a widely used oil-displacement agent, but its poor thermal stability, salt tolerance, and mechanical degradation impeded its use in high-temperature and high-salinity oil reservoirs. In this work, a novel viscoelastic surfactant, erucyl dimethyl amidobetaine (EDAB, with improved thermal stability and salinity tolerance, was complexed with HPAM to overcome the deficiencies of HPAM. The HPAM/EDAB hybrid samples were studied in comparison with HPAM and EDAB in synthetic brine regarding their rheological behaviors and core flooding experiments under simulated high-temperature and high-salinity oil reservoir conditions (T: 85°C; total dissolved solids: 32,868 mg/L; [Ca2+] + [Mg2+]: 873 mg/L. It was found that the HPAM/EDAB hybrids exhibited much better heat- and salinity-tolerance and long-term thermal stability than HPAM. Core flooding tests showed that the oil recovery factors of HPAM/EDAB hybrids are between those of HPAM and EDAB. These results are attributed to the synergistic effect between HPAM and EDAB in the hybrid.

  8. Indicators: Salinity

    Science.gov (United States)

    Salinity is the dissolved salt content of a body of water. Excess salinity, due to evaporation, water withdrawal, wastewater discharge, and other sources, is a chemical sterssor that can be toxic for aquatic environments.

  9. Salinity and temperature tolerance of the mud-flat crab, Helice tientsinensis%天津厚蟹对盐度和温度的耐受性

    Institute of Scientific and Technical Information of China (English)

    徐敬明

    2014-01-01

    研究了天津厚蟹 Helice tientsinensis对盐度和温度的耐受性。天津厚蟹对盐度的耐受能力极强,在温度9~34℃盐度为0的淡水介质中均能存活96 h以上;在10℃、20℃及30℃的高渗介质中暴露96 h后,天津厚蟹全部存活的盐度分别是65、56和50,全部死亡的盐度分别为83、74和68。天津厚蟹对低温的耐受力较强,在0、30和50盐度水平下,耐受低温的能力差别较大,能耐受96 h的最低温度分别是9℃、2℃和6℃。天津厚蟹对高温也有较强的耐受能力,在0、30和50盐度水平下,分别在34℃、36℃和35℃下能耐受96h;盐度50温度38℃时,在开始的24h内无死亡,但48h后死亡率急剧上升,同样规律也出现在30和0溶液中,前者温度是39℃,后者为35℃。研究结果还表明盐度和温度的交互效应显著,二者的交互作用对天津厚蟹的存活亦有显著性影响( P<0.05),温度升高(从10℃到20℃再到30℃)致使其耐盐能力显著下降,而盐度的剧烈变化(从30到50或从30到0)也致使其耐温能力显著下降。%Helice tientsinensis burrow in the intertidal mudflats and estuaries especially in the high intertidal and su-pralittoral zones along the coast of northern China . The mature specimens were collected from Rongcheng , Weihai ,China .The salinity and temperature tolerance of the mud-flat crab ,Helice tientsinensis ,were investigated in the laboratory .The salinity tolerance experiment was conducted at 10℃ ,20℃ and 30℃ .Ten salinity gradients including 65 ,68 ,71 ,74 ,77 ,80 ,83 ,86 ,89 and 92 at 10℃ ,and 56 ,59 ,62 ,65 ,68 ,71 ,74 ,77 ,80 and 83 at 20℃ ,and 50 ,53 ,56 ,59 ,62 ,65 ,68 ,71 ,74 and 77 at 30℃ were respectively designed according to the results of pretests .The temperature tolerance experiment was conducted at salinities of 0 ,30 and 50 .In the low tempera-ture tolerance test ,6℃ ,7℃ ,8℃ and 9℃ at 0 salinity ,and 0℃ ,1

  10. Radiolarian artificial neural network based paleo sea surface water temperature and salinity changes during the last glacial cycle in the Timor Sea, Indian Ocean

    Science.gov (United States)

    Gupta, S. M.; Malmgren, B. A.

    2015-12-01

    The western Pacific water enters into the Timor Sea (tropical Indian Ocean) by the thermohaline conveyor belt, and this region is under the influence of the SW monsoon. The higher precipitation during the monsoon rains lower the surface salinity in the north-eastern Indian Ocean towards the Bay of Bengal; whereas, the Arabian Sea remains highly saline due to higher evaporation in the region surrounding Arabian deserts. The salinity contrast in the northern Indian Ocean is very unique, and the radiolarian micro-zooplanktons living in the surface water serve a very good proxy for the monsoonal changes in the surface sea-water temperature (SST) and salinity in the geological past. We studied radiolarian faunal variation in the core MD01-2378, located at ~13oS and ~121oE (1783 m water depth), at the inlet of the thermohaline circulation into the Timor Sea. We applied the modern radiolarian based artificial neural networks (ANNs) (Gupta and Malmgren, 2009) to derive the SST and salinity during August-October for the last 140 ka (the full last glacial cycle). Based on the mean estimates of the 10 ANNs, the root mean square error in prediction (RMSEP) for SST is ~1.4oC with correlation between observed and estimated values r=0.98 (Gupta and Malmgren, 2009). Similarly, the RMSEP is 0.3 psu (r=0.94) for the salinity estimates. We derived paleo-SSTs and salinity values using modern radiolarian ANNs and the fossil radiolarian data generated from the core for the last 140-ka (Fig.1). The age model of the core is based on δ18O benthic oxygen isotope stratigraphy and 21 AMS 14C ages up to ~30-ka (Holbourn et al., 2005). Paleo SST-summer varied between 22-28.5oC, and it is in very good agreement with the δ18O benthic record of Holbourn et al. (2005) defining the Last Glacial Maximum (~24 ka) and the Eemian (~125 ka) stages. The salinity fluctuated between 34-35 psu, and compared well with oxygen isotope record representing the LGM and Eemian periods. We gratefully acknowledge

  11. Groundwater dynamic, temperature and salinity response to the tide in Patagonian marshes: Observations on a coastal wetland in San José Gulf, Argentina

    Science.gov (United States)

    Alvarez, María del Pilar; Carol, Eleonora; Hernández, Mario A.; Bouza, Pablo J.

    2015-10-01

    The processes regulating the relationship between tidal flows and shallow groundwater dynamics, temperature and salinity in a coastal wetland in an arid climate are analysed in a detailed field study carried out in the marsh located at Playa Fracasso (Argentina). The continuous records of groundwater level, temperature and electrical conductivity from a transect perpendicular to the coastline were studied during a period ranging from summer to winter, together with the information obtained in hydrogeomorphological field surveys and soil profiles. An assessment of the processes conditioning marsh hydrology was carried out contemplating seasonal (summer-winter) and periodical variations caused by tidal flows. The study showed that the dynamics of groundwater in relation to tidal flows depends almost exclusively on the infiltration of tidal water when the marsh is flooded during spring tides (syzygy), with an increase in the groundwater discharge level at the onset of syzygy. The differences in temperature between sea and continental water were very useful in defining the origin of the different contributions. Groundwater salinity is mainly associated with the leaching of the soil salts that enter with the sea water infiltrating during flood events. The presence of saline soils in the marsh is regulated by the evapotranspiration predominating in arid zones. The conceptual hydrological model suggested may help in the understanding of the hydrological processes in other similar marshes of Patagonia, as well as in coastal wetlands of arid zones worldwide.

  12. The Aquarius Salinity Retrieval Algorithm

    Science.gov (United States)

    Meissner, Thomas; Wentz, Frank; Hilburn, Kyle; Lagerloef, Gary; Le Vine, David

    2012-01-01

    The first part of this presentation gives an overview over the Aquarius salinity retrieval algorithm. The instrument calibration [2] converts Aquarius radiometer counts into antenna temperatures (TA). The salinity retrieval algorithm converts those TA into brightness temperatures (TB) at a flat ocean surface. As a first step, contributions arising from the intrusion of solar, lunar and galactic radiation are subtracted. The antenna pattern correction (APC) removes the effects of cross-polarization contamination and spillover. The Aquarius radiometer measures the 3rd Stokes parameter in addition to vertical (v) and horizontal (h) polarizations, which allows for an easy removal of ionospheric Faraday rotation. The atmospheric absorption at L-band is almost entirely due to molecular oxygen, which can be calculated based on auxiliary input fields from numerical weather prediction models and then successively removed from the TB. The final step in the TA to TB conversion is the correction for the roughness of the sea surface due to wind, which is addressed in more detail in section 3. The TB of the flat ocean surface can now be matched to a salinity value using a surface emission model that is based on a model for the dielectric constant of sea water [3], [4] and an auxiliary field for the sea surface temperature. In the current processing only v-pol TB are used for this last step.

  13. Coastal Changes in Temperature and Salinity Observed during Hurricane Isaac Recorded and Downloaded by NASA DRIFTERs Moored in Heron Bay and at Half Moon Island, Louisiana

    Science.gov (United States)

    Kalcic, Maria; Iturriaga, Rodolfo H.; Kuper, Philip D.; O'Neal, Stanford Duane; Underwood, Lauren; Fletcher, Rose

    2012-01-01

    Major changes in salinity (approx.14 ppt.) and temperature (approx.40C) were continuously registered by two prototype NASA DRIFTERs, surface moored floaters, that NASA's Applied Science and Technology Project Office (ASTPO) has developed. The DRIFTER floating sensor module is equipped with an Arduino open-source electronics prototyping platform and programming language (http://www.arduino.cc), a GPS (Global Positioning System) module with antenna, a cell phone SIM (Subscriber Identity Module) card and a cellular antenna which is used to transmit data, and a probe to measure temperature and conductivity (from which salinity can be derived). The DRIFTER is powered by a solar cell panel and all the electronic components are mounted and sealed in [ waterproof encasement. Position and measurement data are transmitted via short message service (SMS) messaging to a Twitter site (DRIFTER 002@NASADRIFTER_002 and DRIFTER 004@NASADRIFTER_004), which provides a live feed. These data are the imported into a Google spreadsheet where conductivity is converted to salinity, and graphed in real-time. The spreadsheet data will be imported into a webpage maintained by ASTPO, where it will be displayed available for dO\\\\1lload.

  14. Temperature and Salinity Effects on Bioaccumulation, Gill Structure, and Radiation Dose Estimation in the Milkfish Chanos chanos Exposed to 137Cs

    Directory of Open Access Journals (Sweden)

    W.R. Prihatiningsih

    2016-12-01

    Full Text Available The present trend of global warming has led to an increase in seawater temperature and salinity. The effects of increasing salinity and temperature on the accumulation of 137Cs by milkfish Chanos chanos was studied under laboratory conditions to obtain information on Chanos chanos adaptability under environmental changes. The uptake of radioactive cesium by Chanos chanos increased with temperature of seawater. The concentration factors (CF of 137Cs for temperatures of 25°C, 27°C, 29°C, and 31°C at steady state period were 5.25, 5.91, 6.78, and 9.98 mL g-1 for the whole-body of Chanos chanos. The concentration factors at steady state (CFss of 137Cs for salinities of 26‰, 29‰, 32‰, and 35‰ were 6.23, 9.93, 9.24, and 6.86 mL g-1, respectively. After temperature exposure to 31°C, the fish gills showed hyperplasia of epithelial cells in branchial secondary lamellae, congestion of blood vessels, and hypertrophy of pillar cells. The fish from the treatment group exhibited hemorrhage between the branchial secondary lamellae and an abundance of mucous substance in comparison with control group. This study links radionuclide bioaccumulation data and monitoring data obtained in the field and laboratory experiment with radiation dose determined by ERICA Tools, an approach that will enable better linkages to be made between exposure and dose in Chanos chanos and its marine food web.

  15. Independent Effects of Temperature, Salinity, Ammonium Concentration and pH on Nitrification Rate of the Ariake Seawater Above Mud Sediment

    Directory of Open Access Journals (Sweden)

    Alim Isnansetyo

    2014-03-01

    Full Text Available The Ariake Sea located in the west parts of Kyushu Island is a semi-closed and macro-tidal shallow sea, and has the largest tidal flat in Japan. A large mud tidal flat with a productive ecosystem found along the western shoreline of the sea makes this area ideal as a major production site of nori (Porphyra yezoensis in Japan. We determined the independent effect of temperature, salinity, ammonium concentration and pH on nitrification rates (NR in the Ariake seawater above the mud sediment. The NR was determined by measuring accumulation of NO2-N production after adding sodium chlorate, an inhibitor of NO2-N to NO3-N oxidation. NRs were relatively high at 20-35 oC (optimum at 29.5 oC, but the rates were very low at 5, 10, and 40 oC. NRs increased sharply when increasing the salinity from 13 to 20 ppt, but it decreased drastically at salinity levels more than 35 ppt (optimum at 19 ppt. The relationship between ammonium concentration and NR showed a typical kinetic curve of enzymatic reaction with the maximum NR (Vmax of 0.029 μM N.h-1 at 200 μM NH4-N (the half saturation constant (Ks = 35 μM NH4-N. High NRs were determined at pH 7.5-8.0 (optimum pH 7.8. This is the first report on the independent effects of temperature, pH, salinity and NH4-N concentration on the NR of seawater, specifically the Ariake seawater.

  16. Carbon dioxide, temperature, salinity collected via surface underway in the Indian and North/South Pacific Ocean as part of the EPOCS project from 23 May 1986 to 20 April 1989 (NODC Accession 0000071)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, pCO2 in sea and air data were collected using gas chromatograph and thermosalinograph in the Indian and North/South Pacific Ocean as a part of...

  17. Temperature, salinity, oxygen, silicate, and phosphate data collected in Pacific Ocean from Monterey Submarine Canyon Station by Stanford University from 1951-01-02 to 1955-12-31 (NODC Accession 0093160)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, oxygen, silicate, and phosphate data collected in Pacific Ocean from Montery Submarine Canyon Station by Stanford University from 1951-01-02...

  18. Oceanographic temperature, salinity, oxygen, phosphate, total phosphorus, silicate, nitrite, pH, alkalinity measurements collected using bottle on multiple platforms in the Pacific, Atlantic, Arctic, Mediterranean from 1910 to 1982 (NODC Accession 0038350)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, nutrients, oxygen, and other measurements found in dataset OSD taken from the AGASSIZ; A., ALBACORE and other platforms in the Coastal N...

  19. Temperature and salinity profiles from CTD casts from the ACONA and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 03 August 1976 to 14 September 1976 (NODC Accession 7601779)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profiles were collected from CTD casts from the ACONA and other platforms from 03 August 1976 to 14 September 1976. Data were collected by...

  20. Temperature and Salinity in Kaneohe Bay, Oahu, Hawaii 2005 - 2007 in Support of Fresh Water Plume Studies Performed by the Department of Oceanography at the Univesity of Hawaii (NODC Accession 0039532)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Freshwater plumes from rain run-off into Kaneohe Bay are the focus for the investigation. Measurements of temperature and salinity from a moored, fixed-level CTD and...

  1. Temperature, salinity, and other data collected using bottle, CTD, and XBT casts in the Pacific and Atlantic Ocean from 12 April 1960 to 27 October 1999 (NODC Accession 0000214)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and other data were collected using bottle, CTD, and XBT casts in the North/South Atlantic Ocean and North/South Pacific Ocean from April 12,...

  2. Temperature, salinity and other measurements found in dataset CTD taken from the BARUNA JAYA VIII (FRV; call sign YFZQ; built 08.1998; IMO9155171) in the Coastal Equatorial Pacific, South Indian and other locations in 2005 (NODC Accession 0044407)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity and other measurements found in dataset CTD taken from the BARUNA JAYA VIII (FRV; call sign YFZQ; built 08.1998; IMO9155171) in the Coastal...

  3. Salinity, oxygen, temperature, and other data from CTD casts from the GEOLOG FERSMAN in the North Atlantic Ocean and North Pacific Ocean from 13 July 1990 to 17 October 1991 (NODC Accession 0000232)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity, oxygen, temperature, and other data were collected using CTD casts from the GEOLOG FERSMAN in the North Atlantic Ocean and North Pacific Ocean from to July...

  4. Temperature and salinity measurements taken from the BLUE, PENOBSCOT and other Slocum glider platforms in the Coastal N Atlantic, Coastal S Atlantic and other locations from 2012 to 2014 (NCEI Accession 0123079)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity measurements found in dataset IOOS taken from the BLUE (Slocum glider; WMO 4801504; operated by Univ. of Massachusetts Dartmouth), PENOBSCOT...

  5. Underway pressure, temperature, and salinity data from the MOANA WAVE from the Pacific warm pool in support of the Coupled Ocean-Atmosphere Response Experiment (COARE) from 02 February 1993 to 21 February 1993 (NODC Accession 9600090)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure, temperature, and salinity data were collected while underway from the MOANA WAVE from the Pacific warm pool. Data were collected in support of the Coupled...

  6. Temperature, Salinity, Oxygen, Phosphate, Silicate, Nitrite, pH and Alkalinity data collected in the Black Sea, Tyrrhenian Sea and Western Basin from R/Vs GORIZONT and OKEANOGRAF, 1960 - 1969 (NODC Accession 0074609)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, Salinity, Oxygen, Phosphate, Silicate, Nitrite, pH and Alkalinity data collected in the Black Sea, Tyrrhenian Sea and Western Basin of the Mediterranean...

  7. Temperature, salinity, nutrients, and other data from bottle and CTD casts from a world-wide distribution from the POSEYDON and other platforms from 27 February 1958 to 28 February 1991 (NODC Accession 0000205)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, nutrients, and other data were collected from bottle and CTD casts from the POSEYDON and other platforms. Data were collected from a...

  8. Surface temperature, salinity, and pCO2 collected by bottle casts during a cruise in the north Atlantic Ocean from 9/3/1991 - 9/22/1991 (NODC Accession 0000113)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperature, salinity, and pCO2 data were collected using bottle casts from METEOR in the North Atlantic Ocean. Data were collected from 03 September 1991 to...

  9. Temperature, salinity, oxygen, phosphate, silicate, nitrite, alkalinity, and pH data collected by multiple former Soviet Union institutions from Okhotsk Sea from 1981-09-23 to 1988-06-17 (NODC Accession 0081217)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical temperature, salinity, oxygen, phosphate, silicate, nitrite, alkalinity, and pH data collected by multiple former Soviet Union institutions from Okhotsk...

  10. Temperature and salinity profile data collected from CTD casts by NOAA Ship BAY HYDROGRAPHER in the Chesapeake Bay during survey operations along the NE US coast from 2006-01-05 to 2006-08-28 (NCEI Accession 0014614)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure, salinity, and temperature data were collected from CTD casts from the NOAA Survey Vessel BAY HYDROGRAPHER. Data were collected in the Chesapeake Bay from...

  11. Historical temperature and salinity data collected from 1896-04-22 to 1961-03-26 from the World Ocean and provided by United Kingdom hydrographic office (NODC Accession 0073673)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical temperature and salinity data collected from 1896-04-22 to 1961-03-26 from the World Ocean. Data were digitized from cards provided by United Kingdom...

  12. Water temperature, salinity, and sound speed data collected by CTD and XBT from the R/V Falkor in the NW Hawaiian Islands 2014-03 to 2014-06 (NCEI Accession 0137765)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical parameters (water temperature, salinity, and sound speed) were measured as high-resolution profiles at select locations and times using CTD and XBT...

  13. Temperature and salinity profiles from bottle and STD casts in the Bering Sea from the ACONA as part of the Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 02 July 1974 to 10 July 1974 (NODC Accession 7601138)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profiles were collected from bottle and STD casts in the Bering Sea from the ACONA. Data were collected by the University of Alaska -...

  14. Temperature, salinity and other measurements found in dataset CTD taken from the SOUTHERN SURVEYOR (VLHJ) in the Coastal S Pacific, Equatorial Pacific and other locations from 2003 to 2006 (NODC Accession 0043461)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, chemical, and other data were collected using CTD casts from the SOUTHERN SURVEYOR in the Iceland Sea and North / South Pacific Ocean. Data...

  15. Sea surface temperatures and salinities from platforms in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and the South China Sea (Nan Hai) from 1896-1950 (NODC Accession 0000506)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperatures and salinities were collected in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and South China Sea (Nan Hai)...

  16. Pressure, temperature, and salinity data collected by CTDs from NOAA Ship Rainier in the Gulf of Alaska from 1999-08-12 to 1999-10-28 (NCEI Accession 0000009)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains pressure, temperature, and salinity values collected from 188 CTD casts between the periods of May 27, 1999 to December 15, 1999. NOAA Ship...

  17. Oceanographic profile plankton, Temperature Salinity and other measurements collected using bottle from VICTORIA 1 FISHING BOAT), ALEJERO HUMBOLDT and other platforms in the South Pacific, Coastal S Pacific and other locations from 1980 to 1982 (NODC Accession 0002083)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity and other measurements found in dataset OSD taken from the VICTORIA 1(FISHING BOAT), ALEJERO HUMBOLDT and other platforms in the South...

  18. Temperature and salinity profile data collected from CTD casts by the NOAA vessel NOAA Ship RUDE from the NW Atlantic (limit-40) from 2002-04-24 to 2002-12-06 (NCEI Accession 0000909)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure, salinity, and temperature data were collected using CTD casts from NOAA Ship RUDE. Data were collected from the NW Alantic (limit-40) from 24 April 2002...

  19. Temperature and salinity profile data from CTD casts from the NOAA ship WHITING from the North Atlantic Ocean from 5 April 1995 to 1 June 1995 (NODC Accession 9500092)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profile data were collected from CTD cast from the NOAA ship WHITING from the North Atlantic Ocean. Data were collected from 5 April 1995...

  20. Nutrients, temperature, and salinity from bottle cats in the North Pacific Ocean by the Pacific Research Institute of Fisheries and Oceanography from 27 August 1950 to 17 November 1997 (NODC Accession 0000843)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nutrients, temperature, and salinity data were collected using bottle casts in the North Pacific Ocean from 27 August 1950 to 17 November 1997. Data were submitted...

  1. Temperature, salinity and associated variables collected for MMS Deepwater Program: Northern Gulf of Mexico Continental Slope Habitat and Benthic Ecology from the Gulf of Mexico, 1999 - 2002 (NODC Accession 0002099)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data collection includes profile data containing temperature, salinity and associated variables collected in support of this research program to gain better...

  2. Oceanographic temperature and salinity measurements collected using CTD and XBT from NOAA Ship Nancy Foster/Ronald H Brown in the North Atlantic from 1998 to 2007 (NCEI Accession 0043165)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity and other measurements found in datasets XBT and CTD taken from NOAA Ship RONALD H. BROWN (NOAA SHIP - Call Sign WTEC)(formerly NOAA Ship...

  3. Historical temperature, salinity, oxygen, nutrients and meteorological data collected in the Arctic Ocean and Atlantic Ocean by various countries from 20 Jul 1870 to 17 Jul 1995 (NODC Accession 0085914)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical temperature, salinity, oxygen, nutrients and meteorological data collected in the Arctic Ocean and Atlantic Ocean by various countries from 1870 to 1995,...

  4. Temperature and salinity profile data collected by the NOAA vessel BAY HYDROGRAPHER and the NAVIGATION RESPONSE TEAM 3 from 31 January 2002 to 04 December 2002 (NODC Accession 0000892)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure, salinity, and temperature data were collected from CTD casts from the NOAA Survey Vessel BAY HYDROGRAPHER and the NAVIGATION RESPONSE TEAM 3. Data were...

  5. Temperature and salinity profiles from surface sensors and CTD casts in the Gulf of Alaska from the SURVEYOR as part of the Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 21 September 1975 to 22 September 1975 (NODC Accession 7601224)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profiles were collected from surface sensors and CTD casts in the Gulf of Alaska from the SURVEYOR. Data were collected by the Pacific...

  6. Temperature, salinity, and nutrients profiles from bottle and CTD casts from a world-wide distribution from the OCEANIA and other platforms from 01 January 1928 to 31 December 1999 (NODC Accession 0000204)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and nutrients profiles were collected from bottle and CTD casts from the OCEANIA from 01 January 1928 to 31 December 1999. Data were collected...

  7. Oceanographic profile temperature, salinity, oxygen, and nutrients measurements collected using bottle from the LCM Red in the Alaskan Coastal waters, from the Gerda in the Atlantic Ocean, and from DeSteiguer in the Pacific Ocean (NODC Accession 0002231)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, oxygen and other profile data received at NODC on 06/10/04 by Olga Baranova, digitized from "William J. Teague, Zachariah R. Hallock, Jan M....

  8. Temperature, salinity, nutrients, oxygen, chlorophyll and other measurements found in dataset SISMER taken from the VAUBAN, JEAN CHARCOT (FNOY) and other platforms in the South Pacific, Coastal North Atlantic and other locations from 1983 to 2007 (NODC Accession 0046621)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, nutrients, oxygen, chlorophyll and other measurements found in CTD and OSD datasets taken from the VAUBAN, JEAN CHARCOT (FNOY) and other...

  9. Temperature, salinity, and nutrients data collected from North Atlantic Ocean, White Sea, Mediterranean Sea, Black Sea, and Sea of Azov from 1924-03-19 to 1989-11-19 by multiple Soviet Union institutes (NODC Accession 0077413)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and nutrients data collected from North Atlantic Ocean, White Sea, Mediterranean Sea, Black Sea, and Sea of Azov from 1924-03-19 to 1989-11-19...

  10. Atmospheric variables, nutrients, pH, salinity, and temperature collected by bottle and from meteorological stations in the Sea of Japan and the Yellow Sea from 01 July 1952 to 31 December 1998 (NODC Accession 0000032)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Atmospheric variables, nutrients, pH, salinity, and temperature data were collected using bottle casts in the Sea of Japan from 01 July 1952 to 31 December 1998....

  11. Temperature and salinity profiles from STD casts in the Bering Sea from the SILAS BENT as part of the Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 01 September 1975 to 26 September 1975 (NODC Accession 7600747)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profiles were collected from STD casts in the Bering Sea from the SILAS BENT. Data were collected by the University of Alaska - Fairbanks...

  12. Current hurdles to the success of high temperature membrane reactors

    NARCIS (Netherlands)

    Saracco, G.; Versteeg, G.F.; Swaaij, van W.P.M.

    1994-01-01

    High-temperature catalytic processs performed using inorganic membranes have been in recent years a fast growing area of research, which seems to have not yet reached its peak. Chemical engineers, catalysts and materials scientists have addressed this topic from different viewpoint in a common effor

  13. Gulf of Maine salinity variation and its correlation with upstream Scotian Shelf currents at seasonal and interannual time scales

    National Research Council Canada - National Science Library

    Feng, Hui; Vandemark, Doug; Wilkin, John

    2016-01-01

    ... with remote forcing of Gulf hydrography by upstream advection. These long‐term mooring data are combined with satellite altimeter estimates of upper ocean current anomaly on the adjoining Scotian Shelf (SS...

  14. Phosphorus sorption-desorption and effects of temperature, pH and salinity on phosphorus sorption in marsh soils from coastal wetlands with different flooding conditions.

    Science.gov (United States)

    Bai, Junhong; Ye, Xiaofei; Jia, Jia; Zhang, Guangliang; Zhao, Qingqing; Cui, Baoshan; Liu, Xinhui

    2017-12-01

    Wetland soils act as a sink or source of phosphorus (P) to the overlaying water due to phosphorus sorption-desorption processes. Litter information is available on sorption and desorption behaviors of phosphorus in coastal wetlands with different flooding conditions. Laboratory experiments were conducted to investigate phosphorus sorption-desorption processes, fractions of adsorbed phosphorus, and the effects of salinity, pH and temperature on phosphorus sorption on soils in tidal-flooding wetlands (TW), freshwater-flooding wetlands (FW) and seasonal-flooding wetlands (SW) in the Yellow River Delta. Our results showed that the freshly adsorbed phosphorus dominantly exists in Occluded-P and Fe/AlP and their percentages increased with increasing phosphorus adsorbed. Phosphorus sorption isotherms could be better described by the modified Langmuir model than by the modified Freundlich model. A binomial equation could be properly used to describe the effects of salinity, pH, and temperature on phosphorus sorption. Phosphorus sorption generally increased with increasing salinity, pH, and temperature at lower ranges, while decreased in excess of some threshold values. The maximum phosphorus sorption capacity (Qmax) was larger for FW soils (256 mg/kg) compared with TW (218 mg/kg) and SW soils (235 mg/kg) (p < 0.05). The percentage of phosphorus desorption (Pdes) in the FW soils (7.5-63.5%) was much lower than those in TW (27.7-124.9%) and SW soils (19.2-108.5%). The initial soil organic matter, pH and the exchangeable Al, Fe and Cd contents were important factors influencing P sorption and desorption. The findings of this study indicate that freshwater restoration can contribute to controlling the eutrophication status of water bodies through increasing P sorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Gelation Behavior Study of a Resorcinol–Hexamethyleneteramine Crosslinked Polymer Gel for Water Shut-Off Treatment in Low Temperature and High Salinity Reservoirs

    Directory of Open Access Journals (Sweden)

    Yongpeng Sun

    2017-07-01

    Full Text Available Mature oilfields usually encounter the problem of high watercut. It is practical to use chemical methods for water-shutoff in production wells, however conventional water-shutoff agents have problems of long gelation time, low gel strength, and poor stability under low temperature and high salinity conditions. In this work a novel polymer gel for low temperature and high salinity reservoirs was developed. This water-shutoff agent had controllable gelation time, adjustable gel strength and good stability performance. The crosslinking process of this polymer gel was studied by rheological experiments. The process could be divided into an induction period, a fast crosslinking period, and a stable period. Its gelation behaviors were investigated in detail. According to the Gel Strength Code (GSC and vacuum breakthrough method, the gel strength was displayed in contour maps. The composition of the polymer gel was optimized to 0.25~0.3% YG100 + 0.6~0.9% resorcinol + 0.2~0.4% hexamethylenetetramine (HMTA + 0.08~0.27% conditioner (oxalic acid. With the concentration increase of the polymer gel and temperature, the decrease of pH, the induction period became shorter and the crosslinking was more efficient, resulting in better stability performance. Various factors of the gelation behavior which have an impact on the crosslinking reaction process were examined. The relationships between each impact factor and the initial crosslinking time were described with mathematical equations.

  16. Effects of temperature and salinity on the survival rates of coxicerberus ramosae (Albuquerque, 1978, an interstitial isopod of a Sandy Beach on the coast of Brazil

    Directory of Open Access Journals (Sweden)

    Elaine Figueiredo Albuquerque

    2009-10-01

    Full Text Available The tolerance to the combined effects of temperature and salinity was investigated in the interstitial isopod Coxicerberus ramosae (Albuquerque, 1978, a species of intertidal zone of sandy beaches in Rio de Janeiro, Brazil. The animals were collected on Praia Vermelha Beach. The experiments lasted 24 h and nine salinities and seven temperatures were used for a total of 63 combinations. Thirty animals were tested in each combination. The species showed high survival in most of the combinations. The temperature of 35 ºC was lethal and at 5 ºC, the animals tolerated only a narrow range of salinities. The statistical analyses showed that the effects of temperature and salinity were significant on the survival, which confirmed the euryhalinity and eurythermy of this species.A resistência aos efeitos combinados de temperatura e salinidade foi investigada no isópode intersticial Coxicerberus ramosae (Albuquerque, 1978 encontrado comumente na zona intertidal de praias arenosas do Rio de Janeiro, Brasil. Os exemplares foram coletados na Praia Vermelha. Os experimentos tiveram a duração de 24 horas e nove salinidades e sete temperaturas foram utilizadas, perfazendo um total de 63 combinações. Em cada combinação de T e S foram testados 30 animais. A espécie mostrou um grande percentual de sobrevivência na maior parte das combinações. A temperatura de 35ºC foi letal e na temperatura de 5ºC a espécie resistiu a uma faixa estreita de salinidades. As análises estatísticas mostraram que tanto os efeitos da temperatura como da salinidade e da interação entre estes fatores foram significativos na sobrevivência da espécie.O alto percentual de sobrevivência da espécie nas diferentes combinações de temperatura e salinidade, confirma, portanto, a eurialinidade e a euritermia da espécie, características comuns das espécies intersticiais litorais.

  17. Huge inelastic current at low temperature in graphene nanoribbons

    Science.gov (United States)

    Li, Bo-Lin; Chen, Ke-Qiu

    2017-02-01

    The nonequilibrium Green’s function and the generalized lowest-order expansion method with consideration of electron-phonon interactions (EPIs) are used to investigate the spin-dependent electronic transport properties of ferromagnetic zigzag graphene nanoribbons. Results show that the consideration of EPIs will lead to a 4-5 orders of magnitude increase of the current in some bias regions when the spin polarizations of two electrodes are antiparallel. This results in the vanishing of the dual spin filtration effect and a narrowing of the effective bias region of giant magnetoresistance. The increases of the current mainly from the first Born scattering process, and can be described by the Fermi’s golden rule, and may be a result of the breaking of the structural symmetry by the introduction of phonons.

  18. A Magnetic Persistent Current Switch at milliKelvin Temperatures

    CERN Document Server

    van Waarde, Bob; Oosterkamp, Tjerk

    2016-01-01

    We report the development of a magnetically driven Persistent Current Switch operated in a dilution refrigerator. We show that it can be safely used to charge a 60 mH coil with 0.5 A at 11 mK, which heats up the dilution refrigerator to 60.5 mK. Measurements at 4 K on a 440 $\\mu$H coil reveal a residual resistance of $R \\leqslant 3.3$ p$\\Omega$.

  19. Spectra of currents and temperature off Godavari (east coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, M.S.S; Rao, L.V.G.

    Time series data of currents and temperature obtained from a mooring of current meters off Godavari (East Coast of India) during September 1980 are analysed to study the space scales of semidiurnal and internal oscillations in the range of buoyancy...

  20. Note: Temperature effects in the modified Howland current source for electrical bioimpedance spectroscopy

    Science.gov (United States)

    Fernandez Santos, S.; Bertemes-Filho, P.

    2017-07-01

    The aim of this study is to show how the modified Howland current source (MHCS) is affected by temperature changes. The source has been tested in a temperature range from 20 to 70 °C and frequency range from 100 Hz to 1 MHz. Parameters like output current, output impedance, total harmonic distortion, and oscillation have been measured. The measurements were made inside a temperature controlled environment. It was showed that the MHCS is stable at temperatures below 70 °C. Operational amplifiers with a low temperature drift and matching resistor should be carefully considered in order to prevent oscillations at high temperatures.

  1. Current Sharing inside a High Power IGBT Module at the Negative Temperature Coefficient Operating Region

    CERN Document Server

    Asimakopoulos, Panagiotis; Bongiorno, M; Thiringer, T

    2016-01-01

    This work investigates the current sharing effect of a high power Soft Punch Through IGBT module in the Negative Temperature Coefficient region. The unbalanced current sharing between two of the substrates is demonstrated for different current and temperature levels and its impact on the thermal stressing of the device is evaluated. The results indicate that the current asymmetry does not lead to a significant thermal stressing unbalance between the substrates.

  2. The effect of saline coolant on temperature levels during decortication with a Midas Rex: An in vitro model using sheep cervical vertebrae.

    Directory of Open Access Journals (Sweden)

    Asher eLivingston

    2015-07-01

    Full Text Available Decortication of bone with a high speed burr in the absence of coolant may lead to local thermal necrosis and decreased healing ability which may negatively impact clinical outcome. Little data is available on the impact of applying a coolant during the burring process. This study aims to establish an in vitro model to quantitatively assess peak temperatures during endplate preparation with a high speed burr.Six sheep cervical vertebrae were dissected and mounted. Both end plates were used to give a total of 12 sites. Two thermocouples were inserted into each vertebra, 2mm below the end plate surface and a thermal-camera set up to measure surface temperature. A high speed burr (Midas Rex, Medtronic, Fort Worth, TX was used to decorticate the bone in a side to side sweeping pattern, using a matchstick burr (M-8/9MH30 with light pressure. This procedure was repeated while dripping saline onto the burr and bone. Data was compared between groups using a student t-test.Application of coolant at the bone-burr interface during decortication resulted in a significant decrease in final temperature. Without coolant, maximum temperatures 2mm from the surface were not sufficient to cause thermal osteonecrosis, although peak surface temperatures would cause local damage. The use of a high speed burr provides a quick and effective method of vertebral end plate preparation. Thermal damage to the bone can be minimised through the use of light pressure and saline coolant. This has implications for any bone preparation performed with a high speed burr.

  3. Incorporating future change into current conservation planning: Evaluating tidal saline wetland migration along the U.S. Gulf of Mexico coast under alternative sea-level rise and urbanization scenarios

    Science.gov (United States)

    Enwright, Nicholas M.; Griffith, Kereen T.; Osland, Michael J.

    2015-11-02

    In this study, the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, quantified the potential for landward migration of tidal saline wetlands along the U.S. Gulf of Mexico coast under alternative future sea-level rise and urbanization scenarios. Our analyses focused exclusively on tidal saline wetlands (that is, mangrove forests, salt marshes, and salt flats), and we combined these diverse tidal saline wetland ecosystems into a single grouping, “tidal saline wetland.” Collectively, our approach and findings can provide useful information for scientists and environmental planners working to develop future-focused adaptation strategies for conserving coastal landscapes and the ecosystem goods and services provided by tidal saline wetlands. The primary product of this work is a public dataset that identifies locations where landward migration of tidal saline wetlands is expected to occur under alternative future sea-level rise and urbanization scenarios. In addition to identifying areas where landward migration of tidal saline wetlands is possible because of the absence of barriers, these data also identify locations where landward migration of these wetlands could be prevented by barriers associated with current urbanization, future urbanization, and levees.

  4. Development of high temperature superconductors having high critical current density

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Gye Wong; Kim, C. J.; Lee, H.G.; Kwon, S. C.; Lee, H. J.; Kim, K. B.; Park, J. Y.; Jung, C. H

    2000-08-01

    Fabrication of high T{sub c} superconductors and its applications for electric power device were carried out for developing superconductor application technologies. High quality YBCO superconductors was fabricated by melt texture growth, top-seeded melt growth process and multi-seeded melt growth process and the properties was compared. The critical current density of the melt processed YBCO superconductors was about few 10,000 A/cm{sup 2} and the levitation force was 50 N. The processing time needed for the growth of the 123 single grain was greatly reduced by applying multi-seeding without no significant degradation of the levitation force. The multi-seeded melt growth process was confirmed as a time-saving and cost-effective method for the fabrication of bulk superconductors with controlled crystallographic orientation.

  5. High Performance CMOS Light Detector with Dark Current Suppression in Variable-Temperature Systems.

    Science.gov (United States)

    Lin, Wen-Sheng; Sung, Guo-Ming; Lin, Jyun-Long

    2016-12-23

    This paper presents a dark current suppression technique for a light detector in a variable-temperature system. The light detector architecture comprises a photodiode for sensing the ambient light, a dark current diode for conducting dark current suppression, and a current subtractor that is embedded in the current amplifier with enhanced dark current cancellation. The measured dark current of the proposed light detector is lower than that of the epichlorohydrin photoresistor or cadmium sulphide photoresistor. This is advantageous in variable-temperature systems, especially for those with many infrared light-emitting diodes. Experimental results indicate that the maximum dark current of the proposed current amplifier is approximately 135 nA at 125 °C, a near zero dark current is achieved at temperatures lower than 50 °C, and dark current and temperature exhibit an exponential relation at temperatures higher than 50 °C. The dark current of the proposed light detector is lower than 9.23 nA and the linearity is approximately 1.15 μA/lux at an external resistance RSS = 10 kΩ and environmental temperatures from 25 °C to 85 °C.

  6. Salinity Energy.

    Science.gov (United States)

    Schmitt, Walter R.

    1987-01-01

    Discussed are the costs of deriving energy from the earth's natural reserves of salt. Argues that, as fossil fuel supplies become more depleted in the future, the environmental advantages of salinity power may prove to warrant its exploitation. (TW)

  7. Aqueous Hybrids of Silica Nanoparticles and Hydrophobically Associating Hydrolyzed Polyacrylamide Used for EOR in High-Temperature and High-Salinity Reservoirs

    Directory of Open Access Journals (Sweden)

    Dingwei Zhu

    2014-06-01

    Full Text Available Water-soluble polymers are known to be used in chemically enhanced oil recovery (EOR processes, but their applications are limited in high-temperature and high-salinity oil reservoirs because of their inherent poor salt tolerance and weak thermal stability. Hydrophobic association of partially hydrolyzed polyacryamide (HAHPAM complexed with silica nanoparticles to prepare nano-hybrids is reported in this work. The rheological and enhanced oil recovery (EOR properties of such hybrids were studied in comparison with HAHPAM under simulated high-temperature and high-salinity oil reservoir conditions (T: 85 °C; total dissolved solids: 32,868 mg∙L−1; [Ca2+] + [Mg2+]: 873 mg∙L−1. It was found that the apparent viscosity and elastic modulus of HAHPAM solutions increased with addition of silica nanoparticles, and HAHPAM/silica hybrids exhibit better shear resistance and long-term thermal stability than HAHPAM in synthetic brine. Moreover, core flooding tests show that HAHPAM/silica hybrid has a higher oil recovery factor than HAHPAM solution.

  8. Spatially-Resolved Influence of Temperature and Salinity on Stock and Recruitment Variability of Commercially Important Fishes in the North Sea.

    Science.gov (United States)

    Akimova, Anna; Núñez-Riboni, Ismael; Kempf, Alexander; Taylor, Marc H

    2016-01-01

    Understanding of the processes affecting recruitment of commercially important fish species is one of the major challenges in fisheries science. Towards this aim, we investigated the relation between North Sea hydrography (temperature and salinity) and fish stock variables (recruitment, spawning stock biomass and pre-recruitment survival index) for 9 commercially important fishes using spatially-resolved cross-correlation analysis. We used high-resolution (0.2° × 0.2°) hydrographic data fields matching the maximal temporal extent of the fish population assessments (1948-2013). Our approach allowed for the identification of regions in the North Sea where environmental variables seem to be more influential on the fish stocks, as well as the regions of a lesser or nil influence. Our results confirmed previously demonstrated negative correlations between temperature and recruitment of cod and plaice and identified regions of the strongest correlations (German Bight for plaice and north-western North Sea for cod). We also revealed a positive correlation between herring spawning stock biomass and temperature in the Orkney-Shetland area, as well as a negative correlation between sole pre-recruitment survival index and temperature in the German Bight. A strong positive correlation between sprat stock variables and salinity in the central North Sea was also found. To our knowledge the results concerning correlations between North Sea hydrography and stocks' dynamics of herring, sole and sprat are novel. The new information about spatial distribution of the correlation provides an additional help to identify mechanisms underlying these correlations. As an illustration of the utility of these results for fishery management, an example is provided that incorporates the identified environmental covariates in stock-recruitment models.

  9. Current correlation functions of ideal Fermi gas at finite temperature

    Indian Academy of Sciences (India)

    R P Kaur; K Tankeshwar; K N Pathak

    2002-04-01

    Expressions for transverse and longitudinal current–current correlation functions of an ideal Fermi gas describing the current fluctuations induced in the electron system by external probe perpendicular and parallel to the propagation of electron wave, have been obtained at finite temperature. The results obtained for transverse and longitudinal functions are presented for different values of wavelength and frequency at different temperatures. The diamagnetic susceptibility as a function of temperature has also been obtained from transverse current correlation function as its long wavelength and static limit, which smoothly cross over from known quantum values to the classical limit with increase in temperature.

  10. The effect of strong salinity and temperature gradients on transport processes and the formation of bathyal authigenic gypsum at a marine mud volcano

    Science.gov (United States)

    Haffert, L.; Haeckel, M.

    2012-04-01

    A thermodynamic activity model (Pitzer approach) applicable to extreme environmental pTS-conditions (up to 1000 bar, 200 ° C and 6 M NaCl) coupled to an extensive mineral database has been developed. The advantage of this code over existing ones, such as Phreeqc, Wateq, Minteq, is the additional integration of a comprehensive pressure correction, as well as the flexibility on the choice of input datasets, allowing fine-tuning of the model according the relevant pTS range. An example of the successful application of the model is the interpretation of near-surface pore water profiles from the Mercator mud volcano in the Gulf of Cadiz. These profiles are intriguing for two reasons. First, they are characterised by a strong salinity gradient in the upper 1-2 mbsf created by the mixing of upward advecting hypersaline (halite and gypsum saturated, S=360) mud volcano fluids and seawater (S=35) and, second, the pore water profiles encompass various types of authigenic gypsum (CaSO4·2H2O) and anhydrite (CaSO4) crystals, which usually form only in evaporitic environments. It was found that while high Ca and SO4 concentrations from dissolution of an underlying diapir provide gypsum saturated fluids, the occurrence of supersaturation and thus authigenic gypsum (or anhydrite) precipitation is only possible through the reduction of temperature. In addition to the strong temperature control, the salinity has an important impact on the resultant composition of the precipitating CaSO4 minerals. Increasing salinity significantly lowers the activity of water, thereby raising the gypsum-anhydrite transition zone from >1 km to about 500 m sediment depth at the MMV and during heat pulses (> 30 ° C) even to within a few metres below the seafloor. Another effect of the strong salinity gradient is its influence on the diffusive transport of solutes. When comparing the activity and concentration profiles of dissolved species at the Mercator mud volcano, it becomes obvious that here the

  11. High temperature superconducting current lead test facility with heat pipe intercepts

    Energy Technology Data Exchange (ETDEWEB)

    Blumenfeld, P.E.; Prenger, C.; Roth, E.W.; Stewart, J.A.

    1998-12-31

    A high temperature superconducting (HTS) current lead test facility using heat pipe thermal intercepts is under development at the Superconducting Technology Center at Los Alamos National Laboratory. The facility can be configured for tests at currents up to 1,000 A. Mechanical cryocoolers provide refrigeration to the leads. Electrical isolation is maintained by intercepting thermal energy from the leads through cryogenic heat pipes. HST lead warm end temperature is variable from 65 K to over 90 K by controlling heat pipe evaporator temperature. Cold end temperature is variable up to 30 K. Performance predictions in terms of heat pipe evaporator temperature as a function of lead current are presented for the initial facility configuration, which supports testing up to 200 A. Measurements are to include temperature and voltage gradient in the conventional and HTS lead sections, temperature and heat transfer rate in the heat pipes. as well as optimum and off-optimum performance of the conventional lead sections.

  12. A New 1-V Second-Order Temperature-Compensated Current Reference

    Institute of Scientific and Technical Information of China (English)

    YI Jun; ZHANG Bo; FANG Jian; LI Zhaoji

    2004-01-01

    A new bipolar temperature-compensated current reference is proposed.The first-order temperature compensation is achieved by the idea of self temperature-compensation configuration exploiting the temperature coefficient of a combined resistor.The second-order compensation employs a VBE-tracking thermal-startup technique to obtain improved temperature performance.The proposed circuit can operate down to a 1-V supply.A temperature coefficient of 46.6 ×10-6/ ℃ [0,100 ℃] at a 1-V supply and a supply regulation of 0.036%/V at 25 ℃ are achieved.Compared with present works,the proposed circuit shows better results of the temperature coefficient and supply regulation.The current matching issue frequently encountered in current references is also discussed in detail.

  13. Calculation of Gas and Electronic Temperatures in the Channel of the Direct Current Arc

    Science.gov (United States)

    Gerasimov, Alexander V.; Kirpichnikov, Alexander P.

    2009-10-01

    The results of calculations of gas and electronic temperatures in the channel of an arc plasma generator are presented. The calculations were carried out within the framework of a self-consistent two-temperature channel model of an arc discharge. The given method can be used with good precision to determine the radial distribution of gas and electronic temperatures in conducting and non-conducting zones of a constant current arc at designated parameters of the discharge (current intensity and power).

  14. The use of salinity contrast for density difference compensation to improve the thermal recovery efficiency in high-temperature aquifer thermal energy storage systems

    Science.gov (United States)

    van Lopik, Jan H.; Hartog, Niels; Zaadnoordijk, Willem Jan

    2016-08-01

    The efficiency of heat recovery in high-temperature (>60 °C) aquifer thermal energy storage (HT-ATES) systems is limited due to the buoyancy of the injected hot water. This study investigates the potential to improve the efficiency through compensation of the density difference by increased salinity of the injected hot water for a single injection-recovery well scheme. The proposed method was tested through numerical modeling with SEAWATv4, considering seasonal HT-ATES with four consecutive injection-storage-recovery cycles. Recovery efficiencies for the consecutive cycles were investigated for six cases with three simulated scenarios: (a) regular HT-ATES, (b) HT-ATES with density difference compensation using saline water, and (c) theoretical regular HT-ATES without free thermal convection. For the reference case, in which 80 °C water was injected into a high-permeability aquifer, regular HT-ATES had an efficiency of 0.40 after four consecutive recovery cycles. The density difference compensation method resulted in an efficiency of 0.69, approximating the theoretical case (0.76). Sensitivity analysis showed that the net efficiency increase by using the density difference compensation method instead of regular HT-ATES is greater for higher aquifer hydraulic conductivity, larger temperature difference between injection water and ambient groundwater, smaller injection volume, and larger aquifer thickness. This means that density difference compensation allows the application of HT-ATES in thicker, more permeable aquifers and with larger temperatures than would be considered for regular HT-ATES systems.

  15. Statistical properties and time-frequency analysis of temperature, salinity and turbidity measured by the MAREL Carnot station in the coastal waters of Boulogne-sur-Mer (France)

    Science.gov (United States)

    Kbaier Ben Ismail, Dhouha; Lazure, Pascal; Puillat, Ingrid

    2016-10-01

    In marine sciences, many fields display high variability over a large range of spatial and temporal scales, from seconds to thousands of years. The longer recorded time series, with an increasing sampling frequency, in this field are often nonlinear, nonstationary, multiscale and noisy. Their analysis faces new challenges and thus requires the implementation of adequate and specific methods. The objective of this paper is to highlight time series analysis methods already applied in econometrics, signal processing, health, etc. to the environmental marine domain, assess advantages and inconvenients and compare classical techniques with more recent ones. Temperature, turbidity and salinity are important quantities for ecosystem studies. The authors here consider the fluctuations of sea level, salinity, turbidity and temperature recorded from the MAREL Carnot system of Boulogne-sur-Mer (France), which is a moored buoy equipped with physico-chemical measuring devices, working in continuous and autonomous conditions. In order to perform adequate statistical and spectral analyses, it is necessary to know the nature of the considered time series. For this purpose, the stationarity of the series and the occurrence of unit-root are addressed with the Augmented-Dickey Fuller tests. As an example, the harmonic analysis is not relevant for temperature, turbidity and salinity due to the nonstationary condition, except for the nearly stationary sea level datasets. In order to consider the dominant frequencies associated to the dynamics, the large number of data provided by the sensors should enable the estimation of Fourier spectral analysis. Different power spectra show a complex variability and reveal an influence of environmental factors such as tides. However, the previous classical spectral analysis, namely the Blackman-Tukey method, requires not only linear and stationary data but also evenly-spaced data. Interpolating the time series introduces numerous artifacts to the

  16. Effect of 2,4-dihydroxybenzophenone (BP1) on early life-stage development of the marine copepod Acartia tonsa at different temperatures and salinities

    DEFF Research Database (Denmark)

    Kusk, Kresten Ole; Avdolli, Manola; Wollenberger, Leah

    2011-01-01

    Benzophenone (BP)-type ultraviolet (UV) filters are widely used in cosmetic and sunscreen products and can enter the aquatic environment. Therefore, we investigated the subchronic toxicity of 2,4-dihydroxybenzophenone (BP1) on the marine calanoid copepod Acartia tonsa in an early life-stage devel......Benzophenone (BP)-type ultraviolet (UV) filters are widely used in cosmetic and sunscreen products and can enter the aquatic environment. Therefore, we investigated the subchronic toxicity of 2,4-dihydroxybenzophenone (BP1) on the marine calanoid copepod Acartia tonsa in an early life......-stage development study. Since developmental endpoints depend on environmental conditions, a preceding study of A. tonsa development was performed at three temperatures, four salinities, four light:dark regimes, six food densities, and four culture densities. Times elapsed until 50% of the population had reached...... a copepodite stage (DT(½) ) at the different conditions were calculated. The DT(½) values decreased from 296 h at 15°C to 89 h at 25°C and were also affected by salinity (126 h at 15‰ and 167 h at 30‰), whereas the light:dark regime and culture density influenced development only to a minor extent. BP1...

  17. Using TOUGH2/ECO2H for modeling high-pressure and high-temperature CO2-enhanced geothermal energy extraction from saline systems

    Science.gov (United States)

    Borgia, A.; Pruess, K.; Kneafsey, T. J.; Oldenburg, C. M.

    2011-12-01

    Conventional geothermal energy uses water as the fluid to transport heat to the surface. This has a number of drawbacks principally related to strong water-rock chemical reactions, but also in terms of environmental impacts through overdraft of shallow aquifers with valuable water resources. Various authors have proposed the use of CO2 instead of water to transfer heat because such use may result in better rate of heat extraction, less fluid-rock reactivity, and less demand for scarce ground or surface water resources. TOUGH2/ECO2H was developed to study the behavior of high-pressure high-temperature H2O-CO2-NaCl geothermal systems. To demonstrate and test the code, we have modeled an idealized fractured geothermal system. Based on a five-spot well pattern and its inherent symmetry, we use a model grid of 1/8 of a square with sides of 1 km. In the model, CO2 is injected at the four corner-wells at 20 °C and constant pressure of 2.1*10^7 Pa into a variable salinity reservoir which is initially at 200 °C. The center well produces fluid at a constant pressure of 1.9*10^7 Pa. Initially, H2O + NaCl are produced, followed by a mixture of H2O + CO2 + NaCl and, finally only CO2. As soon as the injected CO2 reaches the production well, usually less than 2 months after injection begins, there is a drastic drop in heat production. This decrease occurs because of a reduced flow rate induced by reduction in effective permeability associated with two-phase flow (liquid + gas) in the reservoir. As the liquid phase dries out, the CO2 flow rate increases slowly over about 2-3 years and the heat production reaches a maximum rate that is about 40% larger than the initial rate of production with just water. Our modeling suggests that this same behavior occurs for highly saline geothermal reservoirs, even though the absolute rate of heat production is about 30% lower than the non-saline models. The decrease in production for saline systems is due to a marked reduction in permeability

  18. Development of Cryocooled Binary Current Lead in Low Temperature Superconducting Magnet System

    Science.gov (United States)

    Choi, Y. S.; Kim, D. L.; Yang, H. S.

    2010-04-01

    The binary current lead cooled by a two-stage cryocooler for an NbTi superconducting magnet was designed, fabricated and tested. A binary current lead comprises a resistive element, conducting the current from a room temperature to an intermediate temperature, and an HTS element, conducting the current down to a liquid helium temperature. The temperatures at the joints between resistive and HTS element as well as HTS element and NbTi coil were measured during cool-down process and in the steady state. Thermal loads at each stage were derived from the measured temperatures and cooling capacity curve of a cryocooler. Since a commercial HTS lead was bolt-jointed to the resistive element and NbTi coil at both ends, contact resistance was unavoidable. When the magnet was charged, the temperature at each joint increased with supplied current depending on the amount of heat generation resulting from the contact resistance. The critical current was observed in our lead due to heat generation, and temperature rising decreased after modifying the shape of joint between HTS element and NbTi coil. The current leads supplied 194 A to generate central magnetic field of 3 T and performed reliably over two weeks.

  19. Rail temperature rise characteristics caused by linear eddy current brake of high-speed train

    Directory of Open Access Journals (Sweden)

    Xiaoshan Lu

    2014-12-01

    Full Text Available The rail temperature rises when the linear eddy current brake of high-speed train is working, which may lead to a change of rail physical characteristics or an effect on train operations. Therefore, a study concerning the characteristics of rail temperature rise caused by eddy current has its practical necessity. In the research, the working principle of a linear eddy current brake is introduced and its FEA model is established. According to the generation mechanism of eddy current, the theoretical formula of the internal energy which is produced by the eddy current is deduced and the thermal load on the rail is obtained. ANSYS is used to simulate the rail temperature changes under different conditions of thermal loads. The research result shows the main factors which contribute to the rising of rail temperature are the train speed, brake gap and exciting current. The rail temperature rises non-linearly with the increase of train speed. The rail temperature rise curve is more sensitive to the exciting current than the air gap. Moreover, the difference stimulated by temperature rising between rails of 60 kg/m and 75 kg/m is presented as well.

  20. Oceanographic profile temperature, salinity and other measurements collected using bottle in the Arctic in 1934 (NODC Accession 0001244)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and meteorological data were collected using bottle casts in the Barents Sea, Kara Sea, Laptev Sea, White Sea, and Arctic Ocean. Data were...

  1. Oceanographic profile temperature and salinity measurements collected using bottle from the UGLOMER in the Arctic in 1961 (NCEI Accession 0001128)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and meteorological data were collected using bottle casts from the UGLOMER in the Barents Sea, Kara Sea, Laptev Sea, and White Sea. Data were...

  2. Temperature field at time of pulse current discharge in metal structure with elliptical embedding crack

    Institute of Scientific and Technical Information of China (English)

    FU Yu-ming; TIAN Zhen-guo; ZHENG Li-juan; LI Wei

    2008-01-01

    Theoretical analysis is made on the temperature field at the time of pulse current discharge in a metal structure with an elliptical embedding crack. In finding the temperature field, analogy between the current flow through an elliptical embedding crack and the fluid flow through a barrier is made based on the similarity principle. Boundary conditions derived from this theory are introduced so that the distribution of current density and the temperature field expressions can be obtained. The study provides a theoretic basis to the applications of stopping spatial crack with electromagnetic heating.

  3. Current sheets with inhomogeneous plasma temperature: Effects of polarization electric field and 2D solutions

    Energy Technology Data Exchange (ETDEWEB)

    Catapano, F., E-mail: menacata3@gmail.com; Zimbardo, G. [Dipartimento di Fisica, Università della Calabria, Rende, Cosenza (Italy); Artemyev, A. V., E-mail: ante0226@gmail.com; Vasko, I. Y. [Space Research Institute, RAS, Moscow (Russian Federation)

    2015-09-15

    We develop current sheet models which allow to regulate the level of plasma temperature and density inhomogeneities across the sheet. These models generalize the classical Harris model via including two current-carrying plasma populations with different temperature and the background plasma not contributing to the current density. The parameters of these plasma populations allow regulating contributions of plasma density and temperature to the pressure balance. A brief comparison with spacecraft observations demonstrates the model applicability for describing the Earth magnetotail current sheet. We also develop a two dimensional (2D) generalization of the proposed model. The interesting effect found for 2D models is the nonmonotonous profile (along the current sheet) of the magnetic field component perpendicular to the current sheet. Possible applications of the model are discussed.

  4. Dependence on injection temperature and on aquifer's petrophysical properties of the local stress applying on the pore wall of a crystallized pore in the context of CO2 storage in deep saline aquifers

    Science.gov (United States)

    Osselin, Florian; Fen-Chong, Teddy; Fabbri, Antonin; Lassin, Arnault; Pereira, Jean-Michel; Dangla, Patrick

    2013-11-01

    The development of CCS (carbon capture and storage) currently faces numerous problems and particularly the precipitation of salts induced by the drying of the porous medium during injection of carbon dioxide in deep saline aquifers. This precipitation has several consequences, and particularly the creation of a crystallization pressure which can have an important mechanical impact on the host rock. Literature on crystallization pressure is one century rich of experimental and theoretical works. However, applications have been performed in the field of civil engineering and building science only, and, despite they are of paramount importance in the context of CCS, studies about this phenomenon in deep reservoir conditions are currently lacking. In this paper, we retrieve the classic crystallization pressure equation within the framework of geochemistry and present its explicit form of dependence with temperature, pressure, and composition. Evaluation of the crystallization pressure has then been proceeded considering the injection conditions and a sketch of in-pore crystallization process. The evolution of the local stress transmitted to a crystallized pore wall is found to be strongly related to the petrophysical properties of the medium and to the injection temperature of the carbon dioxide under the assumption of constant salt concentration during the precipitation process. Values differ strongly with the considered mineral, depending particularly on the solubility, and can reach in some conditions 165 MPa, making crystallization pressure a major factor in the mechanical behavior of the aquifer.

  5. Sun L-Band Brightness Temperature Estimate from Soil Moisture and Ocean Salinity (SMOS) Mission: A Potential New Space Weather Applications for SMOS Data

    Science.gov (United States)

    Crapolicchio, Raffaele; Capolongo, Emiliano; Bigazzi, Alberto

    2016-08-01

    The paper presents the results of a validation study to assess the potentiality of the Level-1b (L1b) Soil Moisture and Ocean Salinity (SMOS) Sun Brightness Temperature (BT) as a valuable L-band radio signal useful in the space weather context. The validation exercise, done for both eruptive and quite/active Sun, focused on SMOS data availability, coverage and statistical analysis with respect to the United States Air Force (USAF) Radio Solar Telescope Network (RSTN) recorded data. In both cases the comparison of the two data sets has shown a strong timing correlation and an impressive burst amplitude correspondence. The paper also presents main advantages and some caveats in the use of the SMOS dataset. The results obtained encourage to pursue further studies both on the SMOS L1 processing algorithm refinement and on the usage of SMOS BT as an additional, independent and important source of information for space weather applications.

  6. New concept of current switch based on high-temperature superconductor

    CERN Document Server

    Ovchinnikov, S G; Balaev, D A; Gokhfel'd, D M; Kharlamova, S A; Shajkhutdinov, K A; Kirko, V I; Ivanov, V V; Militsyn, S V; Mamalis, A G

    2001-01-01

    A new concept of alternating current circuit protection device on the basis of combination of a superconducting short circuit (SC) current limiter and an electric circuit breaker was suggested. High-temperature superconductor as a stack of plane rings was used as active element in the superconducting current limiter. Test results of the limiter mock-up under stationary short circuit conditions are provided. Characteristics of composite materials, that do not contain silver, which are used for current breaker designing, are presented

  7. Cytogenetic and viability effects of petroleum aromatic and PCB hydrocarbons, temperature and salinity, on early development of the American oyster, Crassostrea virginica Gmelin

    Energy Technology Data Exchange (ETDEWEB)

    Stiles-Jewell, S.

    1994-01-01

    Fertilized eggs were exposed to 0.1, 10 and 100 mg/l of benzene, naphthalene and Aroclor 1254 individually and in combination in seawater at temperatures and salinities of 20 and 25. Toxicity was measured as frequencies of: (1) meiotic and mitotic abnormalities in 3-hour embryos; (2) total development to the 48-hour straight-hinge larval stage; (3) mortality and abnormality at the 48-hour larval stage; (4) mean size of larvae at 48 hours; and (5) cytogenetic and cytological abnormalities in 48-hour larvae. Dose-dependent responses were observed. Overall, naphthalene and aroclor at 100 mg/l had few embryos that survived to the stage where they could be examined and scored for cytogenetic and cytological abnormality even by 3-hours post-fertilization. Abnormality of the few embryos available for examination was somewhat higher for aroclor but was significantly higher for naphthalene than for control embryos and those exposed to 0.1 mg/l. At the highest concentration of 100 mg/l, mortality was 100% by the larval stage for naphthalene and aroclor. Though total development and survival of embryos to the larval stage at the 10 mg/l dose were high, many of the larvae were dead or abnormal in the aroclor-exposed cultures. This mean incidence was significantly higher than for all other groups. Larvae developing in these cultures with 10 mg/l were also significantly smaller and cytological condition of the larvae was significantly worse. Higher temperature appeared to increase the frequency of deleterious effects, particularly for naphthalene and aroclor. Results with salinity were more variable. Overall, results showed that petroleum aromatic hydrocarbons and PCBs can have toxic effects on the development and survival of early life stages of oysters, as well as sublethal effects on growth and cytological condition, depending on dose and interactions with other compound and with environmental variables.

  8. FISH & CHIPS: Single Chip Silicon MEMS CTDL Salinity, Temperature, Pressure and Light sensor for use in fisheries research

    DEFF Research Database (Denmark)

    Hyldgård, Anders; Hansen, Ole; Thomsen, Erik Vilain

    2005-01-01

    A single-chip silicon MEMS CTDL multi sensor for use in aqueous environments is presented. The new sensor chip consists of a conductivity sensor based on platinum electrodes (C), an ion-implanted thermistor temperature sensor (T), a piezoresistive pressure sensor (D for depth/pressure) and an ion...

  9. Hybrid High-Temperature Superconductor Current Leads for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Tai-Yang Research Company (TYRC) of Tallahassee, Florida proposes to build hybrid high-temperature superconducting current leads for space applications,...

  10. Hybrid High-Temperature Superconductor Current Leads for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Tai-Yang Research Company (TYRC) proposes to address the need for high temperature superconducting (HTS) current leads used in an adiabatic demagnetization...

  11. High Temperature, Through the Case Eddy Current Sensor for Blade Vibration Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Preliminary results have shown that low temperature eddy current sensors can provide excellent resolution for blade tip timing, and have the ability to see ?through...

  12. Integrated optic current transducers incorporating photonic crystal fiber for reduced temperature dependence.

    Science.gov (United States)

    Chu, Woo-Sung; Kim, Sung-Moon; Oh, Min-Cheol

    2015-08-24

    Optical current transducers (OCT) are indispensable for accurate monitoring of large electrical currents in an environment suffering from severe electromagnetic interference. Temperature dependence of OCTs caused by its components, such as wave plates and optical fibers, should be reduced to allow temperature-independent operation. A photonic crystal fiber with a structural optical birefringence was incorporated instead of a PM fiber, and a spun PM fiber was introduced to overcome the temperature-dependent linear birefringence of sensing fiber coil. Moreover, an integrated optic device that provides higher stability than fiber-optics was employed to control the polarization and detect the phase of the sensed optical signal. The proposed OCT exhibited much lower temperature dependence than that from a previous study. The OCT satisfied the 0.5 accuracy class (IIEC 60044-8) and had a temperature dependence less than ± 1% for a temperature range of 25 to 78 °C.

  13. World Ocean Atlas 2005, Salinity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — World Ocean Atlas 2005 (WOA05) is a set of objectively analyzed (1° grid) climatological fields of in situ temperature, salinity, dissolved oxygen, Apparent Oxygen...

  14. World Ocean Atlas 2005, Salinity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — World Ocean Atlas 2005 (WOA05) is a set of objectively analyzed (1° grid) climatological fields of in situ temperature, salinity, dissolved oxygen, Apparent Oxygen...

  15. Online Chip Temperature Monitoring Using υce-Load Current and IR Thermography

    DEFF Research Database (Denmark)

    Ghimire, Pramod; Pedersen, Kristian Bonderup; Trintis, Ionut

    2015-01-01

    This paper presents on-state collector-emitter voltage (υce, on)-load current (Ic) method to monitor chip temperature on power insulated gate bipolar transistor (IGBT) modules in converter operation. The measurement method is also evaluated using infrared (IR) thermography. Temperature dependencies...

  16. The impact of oxygen consumption by the shrimp Litopenaeus vannamei according to body weight, temperature, salinity and stocking density on pond aeration: a simulation - doi: 10.4025/actascibiolsci.v33i2.7018 The impact of oxygen consumption by the shrimp Litopenaeus vannamei according to body weight, temperature, salinity and stocking density on pond aeration: a simulation - doi: 10.4025/actascibiolsci.v33i2.7018

    Directory of Open Access Journals (Sweden)

    Rafael Arantes

    2011-05-01

    Full Text Available A simulation was conducted to determinate the impact caused by the combination of Litopenaeus vannamei respiratory rate (mg O2 shrimp-1 h-1, the behavior of SOTR (kg O2 h-1 of mechanical aerators as a function of salinity, as well as the oxygen consumption rate of the pond water and soil (mg O2 L-1 h-1 on the aeration of shrimp ponds (1, 10, 50 and 100 ha stocked with different densities (10, 40 and 120 shrimp m-2, salinities (1, 13, 25 and 37 ppt, temperatures (20, 25 and 30°C, and shrimp wet weight (5, 10, 15 and 20 g. Results showed that under lower salinity, with larger shrimp, and higher stocking density, higher will be the quantity of required 2-HP aerators to keep dissolved oxygen over 50% saturation. In addition, under low salinity, with 5 and 10 g shrimp, independent of stocking density, more aerators per hectare are required and electricity cost is higher at 20°C and salinity 1 ppt. Less aerators and lower electricity cost was observed at 30°C, salinities of 25 and 37 ppt, and shrimp of 15 and 20 g.A simulation was conducted to determinate the impact caused by the combination of Litopenaeus vannamei respiratory rate (mg O2 shrimp-1 h-1, the behavior of SOTR (kg O2 h-1 of mechanical aerators as a function of salinity, as well as the oxygen consumption rate of the pond water and soil (mg O2 L-1 h-1 on the aeration of shrimp ponds (1, 10, 50 and 100 ha stocked with different densities (10, 40 and 120 shrimp m-2, salinities (1, 13, 25 and 37 ppt, temperatures (20, 25 and 30°C, and shrimp wet weight (5, 10, 15 and 20 g. Results showed that under lower salinity, with larger shrimp, and higher stocking density, higher will be the quantity of required 2-HP aerators to keep dissolved oxygen over 50% saturation. In addition, under low salinity, with 5 and 10 g shrimp, independent of stocking density, more aerators per hectare are required and electricity cost is higher at 20°C and salinity 1 ppt. Less aerators and lower electricity cost was

  17. Extracellular enzymatic activities of cold-adapted bacteria from polar oceans and effect of temperature and salinity on cell growth

    Institute of Scientific and Technical Information of China (English)

    Zeng Yinxin; Yu Yong; Chen Bo; Li Huirong

    2004-01-01

    The potential of 324 bacteria isolated from different habitats in polar oceans to produce a variety of extracellular enzymatic activities at low temperature was investigated. By plate assay, lipase, protease, amylase, gelatinase, agarase, chitinase or cellulase were detected. Lipases were generally present by bacteria living in polar oceans. Protease-producing bacteria held the second highest proportion in culturable isolates. Strains producing amylase kept a relative stable proportion of around 30% in different polar marine habitats. All 50 Arctic sea-ice bacteria producing proteases were cold-adapted strains, however, only 20% were psychrophilic. 98% of them could grow at 3% NaCl, and 56% could grow without NaCl. On the other hand, 98% of these sea-ice bacteria produced extracellular proteases with optimum temperature at or higher than 35℃, well above the upper temperature limit of cell growth. Extracellular enzymes including amylase, agarase, cellulase and lipase released by bacteria from seawater or sediment in polar oceans, most expressed maximum activities between 25 and 35℃. Among extracellular enzymes released by bacterial strain BSw20308, protease expressed maximum activity at 40℃, higher than 35℃ of polysaccharide hydrolases and 25℃ of lipase.

  18. Performance test of current lead cooled by a cryocooler in low temperature superconducting magnet system

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yeon Suk, E-mail: ychoi@kbsi.re.kr; Kim, Myung Su

    2013-11-15

    Highlights: •The current lead with multi-contact connector in the joint was fabricated for performance test. •The electrical contact resistance in the joint was measured during magnet charging. •The resistances of the joint were 0.4–0.9 mΩ for 40–80 K. •The heat generation due to electrical contact resistance was reduced below 1 W by multiple spring louvers. -- Abstract: In a low temperature superconducting magnet system, heat leakage through current leads is one of the major factors in cryogenic load. The semi-retractable current lead is a good option because the conductive heat leakage can be eliminated after the excitation of the magnet. It is composed of a normal metal element, conducting the current from room temperature to intermediate temperature, and an HTS element, conducting the current down to liquid helium temperature. The normal metal element is disengaged from the HTS element through the multi-contact connector without disturbance to the insulating vacuum space and without requiring complete removal of the normal metal element. The intermediate block with a lockable set point is thermally connected to the first stage of cryocooler and carries current through a strip of louvered material. The electrical contact resistance of multi-contact connector in the intermediate block is measured during magnet charging process. The effects of current level as well as operating temperature on the heat generation in the joint block are also discussed.

  19. Remotely sensed surface temperature variation of an inland saline lake over the central Qinghai-Tibet Plateau

    Science.gov (United States)

    Ke, Linghong; Song, Chunqiao

    2014-12-01

    Research on surface water temperature (SWT) variations in large lakes over the Qinghai-Tibet Plateau (QTP) has been limited by lack of in situ measurements. By taking advantage of the increased availability of remotely sensed observations, this study investigated SWT variation of Siling Co in central QTP by processing complete MODIS Land surface temperature (LST) images over the lake covering from 2001 to 2013. The temporal (diurnal, intra-annul and inter-annul) variations of Siling Co SWT as well as the spatial patterns were analyzed. The results show that on average from late December to mid-April the lake is in a mixing state of water and ice and drastic diurnal temperature differences occur, especially along the shallow shoreline areas. The extent of spatial variations in monthly SWT ranges from 1.25 °C to 3.5 °C, and particularly large at nighttime and in winter months. The spatial patterns of annual average SWT were likely impacted by the cooling effect of river inflow from the west and east side of the lake. The annual cycle of spatial pattern of SWT is characterized by seasonal reversions between the shallow littoral regions and deep parts due to different heat capacity. Compared to the deep regions, the littoral shallow shoreline areas warms up quickly in spring and summer, and cool down drastically in autumn and winter, showing large diurnal and seasonal variation amplitudes of SWT. Two cold belt zones in the western and eastern side of the lake and warm patches along the southwestern and northeastern shorelines are shaped by the combined effects of the lakebed topography and river runoff. Overall, the lake-averaged SWT increased at a rate of 0.26 °C/decade during 2001-2013. Faster increase of temperature was found at nighttime (0.34 °C/decade) and in winter and spring, consistent with the asymmetric warming pattern over land areas reported in prior studies. The rate of temperature increase over Siling Co is remarkably lower than that over Bangoin

  20. On-chip temperature monitoring of a SiC current limiter

    Energy Technology Data Exchange (ETDEWEB)

    Tournier, D.; Godignon, P.; Millan, J. [Centro Nacional de Microelectronica (CNM), Univ. Autonoma de Barcelona, Bellaterra (Spain); Planson, D.; Chante, J.P. [Centre de Genie Electrique de Lyon (CEGELY) INSA-LYON, UMR 5005 CNRS, Villeurbanne (France); Sarrus, F.; Palma, J.F. de [Ferraz Shawmut, Bonnet de Mure (France)

    2004-07-01

    High voltage and high current potentiality of SiC based devices has been proved, and various devices able to work at high temperature have been reported as well. Nevertheless, packaging is one of the main constrains for high temperature operation of these devices. Up to date, no specific power package has been reported for high temperature operation. Moreover, it is desirable to predict the SiC die temperature to avoid any related failure in order to improve the efficiency of the packaged SiC device. This paper deals with an integrated temperature sensor for SiC current limiting devices. The current limiter is based on a VJFET structure, which capability for dissipating high power density (140 kW/cm{sup 2}), in the limiting state, has been previously demonstrated. Carrier mobility dependence with temperature was extracted from cryogenic measurements. The temperature estimation is based on the measurement of the variation of the electrical resistance (caused by mobility variation) of the sensing device integrated with the current limiter. In this paper we first describe the temperature estimation methodology using various technological solution (from metallic resistor solution to the SiC integrated sensor). Then experimental temperature measurements using an integrated SiC sensor within a packaged current limiting devices will be presented. Electro-thermal measurements on the fabricated devices show that the current limiter is able to work at 205 C under steady state conditions (320 V), without degrading their electrical performances. Finally, perspectives in terms of integration and reliability will be proposed. (orig.)

  1. Effects of salinity, pH and temperature on the re-establishment of bioluminescence and copper or SDS toxicity in the marine dinoflagellate Pyrocystis lunula using bioluminescence as an endpoint

    Science.gov (United States)

    Craig, J.M.; Klerks, P.L.; Heimann, K.; Waits, J.L.

    2003-01-01

    Pyrocystis lunula is a unicellular, marine, photoautotrophic, bioluminescent dinoflagellate. This organism is used in the Lumitox ?? bioassay with inhibition of bioluminescence re-establishment as the endpoint. Experiments determined if acute changes in pH, salinity, or temperature had an effect on the organisms' ability to re-establish bioluminescence, or on the bioassay's potential to detect sodium dodecyl sulfate (SDS) and copper toxicity. The re-establishment of bioluminescence itself was not very sensitive to changes in pH within the pH 6-10 range, though reducing pH from 8 to levels below 6 decreased this capacity. Increasing the pH had little effect on Cu or SDS toxicity, but decreasing the pH below 7 virtually eliminated the toxicity of either compound in the bioassay. Lowering the salinity from 33 to 27??? or less resulted in a substantial decrease in re-establishment of bioluminescence, while increasing the salinity to 43 or 48 ??? resulted in a small decline. Salinity had little influence on the bioassay's quantification of Cu toxicity, while the data showed a weak negative relationship between SDS toxicity and salinity. Re-establishment of bioluminescence showed a direct dependence on temperature, but only at 10??C did temperature have an obvious effect on the toxicity of Cu in this bioassay. ?? 2003 Elsevier Science Ltd. All rights reserved.

  2. Temperature, salinity, transmissivity, pressure, plankton, oxygen, nutrients, chlorophyll, and primary productivity data collected using CTD, bottle, and plankton net from the R/V Italica in the Ross Sea and Magellan Strait during 10th Italian Antarctic Expedition from 1994-11-13 to 1995-04-02 (NODC Accession 0068289)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, transmissivity, pressure, plankton, oxygen, nutrients, chlorophyll, and primary productivity data collected using CTD, bottle, and plankton...

  3. Calorimetric apparatus for alternating current loss measurements on high-temperature superconductors

    Science.gov (United States)

    Magnusson, N.; Hörnfeldt, S.

    1998-09-01

    The use of high-temperature superconductors in electric power components requires the knowledge of their alternating current (ac) losses. Methods are therefore needed to characterize the conductors with respect to their ac losses under applicationlike conditions. In this article we describe a calorimetric setup for ac loss measurements on long length high-temperature superconductors carrying ac transport currents in ac external magnetic fields at variable temperatures. The variable temperature is achieved by a thermal connection between the sample and a cooling machine. Current in copper coils generates the magnetic field parallel to the plane of the tape and perpendicular to the transport current. This current can be induced in the coil-formed sample. Two slightly different methods are used to determine the ac losses, one in which the temperature rise of the sample, caused by the ac losses, is compared to the temperature rise caused by a reference heater and another in which the increase in power dissipation of the sample is compensated for by a reduction of the power dissipation in the heater. Typical results of the ac loss measurements are presented.

  4. Current Sharing Temperature Test and Simulation with GANDALF Code for ITER PF2 Conductor Sample

    Science.gov (United States)

    Li, Shaolei; Wu, Yu; Liu, Bo; Weng, Peide

    2011-10-01

    Cable-in-conduit conductor (CICC) conductor sample of the PF2 coil for ITER was tested in the SULTAN facility. According to the test results, the CICC conductor sample exhibited a stable performance regarding the current sharing temperature. Under the typical operational conditions of a current of 45 kA, a magnetic field of 4 T and a temperature of 5 K for PF2, the test result for the conductor current sharing temperature is 6.71 K, with a temperature margin of 1.71 K. For a comparison thermal-hydraulic analysis of the PF2 conductor was carried out using GANDALF code in a 1-D model, and the result is consistent with the test one.

  5. Performance test of current lead cooled by a cryocooler in low temperature superconducting magnet system

    Science.gov (United States)

    Choi, Yeon Suk; Kim, Myung Su

    2013-11-01

    In a low temperature superconducting magnet system, heat leakage through current leads is one of the major factors in cryogenic load. The semi-retractable current lead is a good option because the conductive heat leakage can be eliminated after the excitation of the magnet. It is composed of a normal metal element, conducting the current from room temperature to intermediate temperature, and an HTS element, conducting the current down to liquid helium temperature. The normal metal element is disengaged from the HTS element through the multi-contact connector without disturbance to the insulating vacuum space and without requiring complete removal of the normal metal element. The intermediate block with a lockable set point is thermally connected to the first stage of cryocooler and carries current through a strip of louvered material. The electrical contact resistance of multi-contact connector in the intermediate block is measured during magnet charging process. The effects of current level as well as operating temperature on the heat generation in the joint block are also discussed.

  6. Two-dimensional Hybrid Simulations of Kinetic Plasma Turbulence: Current and Vorticity vs Proton Temperature

    CERN Document Server

    Franci, Luca; Matteini, Lorenzo; Verdini, Andrea; Landi, Simone

    2016-01-01

    Proton temperature anisotropies between the directions parallel and perpendicular to the mean magnetic field are usually observed in the solar wind plasma. Here, we employ a high-resolution hybrid particle-in-cell simulation in order to investigate the relation between spatial properties of the proton temperature and the peaks in the current density and in the flow vorticity. Our results indicate that, although regions where the proton temperature is enhanced and temperature anisotropies are larger correspond approximately to regions where many thin current sheets form, no firm quantitative evidence supports the idea of a direct causality between the two phenomena. On the other hand, quite a clear correlation between the behavior of the proton temperature and the out-of-plane vorticity is obtained.

  7. RHIC 12x150A current lead temperature controller: design and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Mi, C.; Seberg, S.; Ganetis, Hamdi, K.; Louie, W.; Heppner, G.; Jamilkowski, J.; Bruno, D.; DiLieto, A.; Sirio, C.; Tuozzolo, J.; Sandberg, J.; Unger, K.

    2011-03-28

    There are 60 12 x 150A current leads distributed in six RHIC service buildings; each lead delivers power supply current from room temperature to cryogenic temperature in RHIC. Due to the humid environment, condensation occurs frequently and ice forms quickly during operation, especially during an extensive storage period. These conditions generate warnings and alarms to which personnel must respond and establish temporary solutions to keep the machine operating. In here, we designed a temperature control system to avoid such situations. This paper discusses its design, implementation, and some results. There are six service buildings in the RHIC complex; each building has two valve boxes that transfer room-temperature current cables from the power supplies into superconducting leads, and then transport them into the RHIC tunnel. In there, the transition between the room-temperature lead into superconducting lead is critical and essential; smooth running during the physics store is crucial for the machine's continuing operation. One of the problems that often occurred previously was the icing of these current leads that could result in a potential leakage current onto ground, thereby preventing a continuous supply of physics store. Fig. 1 illustrates a typical example on a power lead. Among the modifications of the design of the valve box, we list below the new requirements for designing the temperature controller to prevent icing occurring: (1) Remotely control, monitor, and record each current lead's temperature in real time. Prevent icing or overheating of a power lead. (2) Include a temperature alarm for the high/low level threshold. In this paper we discuss the design, implementation, upgrades to, and operation of this new system.

  8. Effects of temperature, food deprivation and salinity on growth, RNA/DNA ratio and certain enzyme activities in rainbow trout (Salmo gairdneri Richardson).

    Science.gov (United States)

    Jürss, K; Bittorf, T; Vökler, T; Wacke, R

    1987-01-01

    1. The connection between feeding regime (food deprivation and restricted diet) and thermal acclimation (1-2, 6, 11 and 16 degrees C) was studied in rainbow trout held in diluted seawater (20% S). 2. At 1 degree C, food deprivation effects on all parameters are slight, and on RNA and certain enzymes they are masked by thermal acclimation effects. 3. At a salinity of 20% rainbow trout on a restricted diet and held at 11 degrees C have the highest growth rate. 4. Owing to increasing RNA levels, the RNA/DNA quotient is significantly higher than normal in rainbow trout held at 1 degree C although the fishes do not grow at this temperature. 5. Temperature and feeding both affect the enzymes we studied (liver: G1DH, AspT, arginase, G6PDH, and 6PGDH; kidney: G1DH, AspT, arginase, and Na/K-ATPase; white muscle: AspT and A1T; gill: Na/K-ATPase) differently. Interactions between these two factors also occur in some cases.

  9. Stable overload conditions of high-temperature superconductors at alternating current injection

    Science.gov (United States)

    Romanovskii, V. R.

    2015-01-01

    The stability of alternating current injected into a high-temperature superconductor or into a current-carrying element on its basis is studied under weak cooling. The stability conditions of the current varying with time by a sinusoidal law are studied versus its frequency. It is shown that before unstable states set in, the peak values of the electric field intensity, current, and temperature in the superconductor are higher than the values determining a thermal electrodynamic stability boundary of the current permanently flowing through the superconductor—the so-called thermal quench current. It is found that ultimate stable alternating currents cause high stable thermal losses in superconductors; these losses being not considered in the modern theory of losses. Such stable conditions can be referred to as overload conditions. Analysis shows that there are characteristic times determining the time intervals within which alternating current is stable under overload conditions. Main thermoelectrodynamic mechanisms behind the existence of these intervals are formulated. They explain why the superconductor stable overheating and induced electric field reach high values before the injected alternating current becomes unstable. The existence of overload conditions considerably extends the application area of high-temperature superconductors.

  10. Evaluation of superabsorbent efficiency in response to dehydration frequencies, salinity and temperature and its effect on yield and quality of cotton under deficit irrigation

    Directory of Open Access Journals (Sweden)

    Hamid-Reza Fallahi

    2016-03-01

    Full Text Available Introduction Reduced availability of water resources in many arid countries including Iran, particularly in response to the indiscriminate harvesting of water reservoirs and climate change, has created concerns. Therefore, the sustainable use of water resources especially in agriculture is a necessity for these countries. Strategies such as deficit irrigation and superabsorbent application are two important ways for improving water use efficiency in agricultural lands. In deficit irrigation the crop must be irrigated less than its required water. Therefore, some reduction may occur in crop yield, but the savings in water will improve the water use efficiency (Akbari Nodehi, 2011. Superabsorbent polymers also increase the nutrients and water holding capacity of soil for a long time and thereby reduce crop water requirement. However, the effectiveness of these materials could be affected by dehydration frequencies, temperature and irrigation water quality (Karimi et al., 2009. Due to the limitation of water resources in many parts of Iran, the aim of this study was to investigate the possibility of cotton production under deficit irrigation along with application of different rates of superabsorbent. In addition, simulation of superabsorbent efficiency at different levels of salinity, temperature and dehydration frequencies (swelling and de-swelling were the other objectives in this study. Materials and methods 1. Laboratory experiments In these experiments the effects of temperature (4, 10, 20, 30 and 40 °C, salinity (0, 0.25, 0.5, 0.75 and 1% NaCl solutions at two temperatures of 10 and 25°C and frequency of partial dehydration (from 1 to 5 stages watering and 70% dewatering were simulated on water absorption capacity of superabsorbent polymer at laboratory of environmental stresses, Sarayan Faculty of Agriculture, Birjand University. 2- Field experiment This experiment was designed at Research Station of Sarayan Faculty of Agriculture

  11. Sintering process and critical current density of low activation Mg11B2 superconductors from low temperature to high temperature

    Science.gov (United States)

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, Md; Somer, M.

    2016-08-01

    As the "low activation" superconductor, Mg11B2 has a potential application in superconducting coils for fusion reactor. In present work, the sintering process and critical current density of low activation Mg11B2 superconductors were systemically studied from low temperature to high temperature. It was found that the Jc and Hirr values of Mg11B2 bulks in present work are both obviously higher than that of those samples prepared in previous studies. Furthermore, the low-temperature sintered samples exhibit better Jc performance at high fields than the high-temperature sintered samples, due to strong grain boundaries pinning. On the other hand, the high-temperature sintered samples have higher Jc at low fields compared to low-temperature sintered samples, mainly owing to their better crystallinity and grain connectivity. The highest Jc value (2.20 ×105 A cm-2 at 20 K, self-field) is obtained in the Mg11B2 sample sintered at 850 °C for 45 min.

  12. Imaging cross fault multiphase flow using time resolved high pressure-temperature synchrotron fluid tomography: implications for the geological storage of carbon dioxide within sandstone saline aquifers

    Science.gov (United States)

    Seers, Thomas; Andrew, Matthew; Bijeljic, Branko; Blunt, Martin; Dobson, Kate; Hodgetts, David; Lee, Peter; Menke, Hannah; Singh, Kamaljit; Parsons, Aaron

    2015-04-01

    enhance capillary trapping of CO₂, and may indeed be equitable features for the immobilisation of large volumes of CO₂. However, previous investigations using static microstructural analysis or bulk petrophysical measurements have been incapable of capturing the fundamental pore scale fluid processes at work in such systems. As a consequence, considerable ambiguity remains over the role of microfaults in determining the eventual fate of CO2 injected into sandstone saline aquifers. With this in mind, the present work seeks to investigate the influence of microfaults over the injection of supercritical CO₂ within sandstone saline aquifers. By employing high temperature-elevated pressure fluid tomography, we are able to directly image at pore scale scCO2-brine primary drainage within a sandstone micro-core (Orange Quarry, Bassin de Sud-est, France) intersected by a single cataclastic fault. The time series data reveals that intra-fault capillary heterogeneity plays an important role in the breaching of microfaults by the non-wetting phase (i.e. scCO2). Such low entry pressure regions facilitate bypass of the fault, suggesting that the capacity of microfaults within clean sandstones to act as major baffles or barriers to a buoyantly migrating CO2 plume may have been previously overestimated.

  13. Temperature dependence of rapidly adapting mechanically activated currents in rat dorsal root ganglion neurons.

    Science.gov (United States)

    Jia, Zhanfeng; Ling, Jennifer; Gu, Jianguo G

    2012-08-01

    Rapidly adapting mechanically activated channels (RA) are expressed on somatosensory neurons and thought to play a role in mechanical transduction. Because mechanical sensations can be significantly affected by temperatures, we examined thermal sensitivity of RA currents in cultured dorsal root ganglion (DRG) neurons to see if RA channel activity is highly temperature-dependent. RA currents were evoked from DRG neurons by membrane displacements and recorded by the whole-cell patch-clamp recording technique. We found that RA currents were significantly enhanced by warming temperatures from 22 to 32 °C and reduced by cooling temperatures from 24 to 14 °C. RA channel activation exhibited steep temperature-dependence with a large temperature coefficient (Q10>5) and a high activation energy (Ea>30 kcal/mol). We further showed that RA channel activation by mechanical stimulation led to membrane depolarization, which could result in action potential firing at 22 °C or 32 °C but not at 14 °C. Taken together, our results provide the measurements of thermal dynamics and activation energy of RA channels, and suggest that a high energy barrier is present for RA channels to open. These findings are in agreement with temperature sensitivity of mechanical sensations in mammals.

  14. Oceanographic water temperature, salinity, and velocity collected from Rogue River Mooring off the coast of Oregon from 2000-09-17 to 2004-09-08 (NCEI Accession 0137120)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A single mooring measuring temperature, salinity, and velocity was deployed on the 73 m isobath off the Oregon coast. The mooring was located at 42° 26.49' N, 124°...

  15. Oceanographic profile water temperature and salinity data collected from the Rogue River Mooring off the coast of Oregon from 2000-05-18 to 2000-09-16 (NCEI Accession 0136938)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A single mooring measuring temperature, salinity, and velocity was deployed on the 73 m isobath off the Oregon coast. The mooring was located at 42° 26.49' N, 124°...

  16. Salinity and temperature profile data from XCTD and CTD casts in the North/South Pacific Ocean by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), from 07 January 2002 to 30 March 2003 (NODC Accession 0000860)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity and temperature profile data were collected using XCTD and CTD casts from the R/V MIRAI in the North/South Pacific Ocean from 07 January 2002 to 30 March...

  17. WATER TEMPERATURE, SALINITY, and HYDROSTATIC PRESSURE collected from MV NEPTUNE in Baffin Bay from 2012-07-25 to 2012-08-03 around Iceberg PII-B (NCEI Accession 0131206)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean temperature, salinities and pressures where collected around a large tabular iceberg PII-B from 2012-07-25 to 2012-08-03. The distance from the iceberg of each...

  18. Influence of Assimilation of Subsurface Temperature Measurements on Simulations of Equatorial Undercurrent and South Equatorial Current Along the Pacific Equator

    Science.gov (United States)

    Halpern, David; Leetmaan, Ants; Reynolds, Richard W.; Ji, Ming

    1997-01-01

    Equatorial Pacific current and temperature fields were simulated with and without assimilation of subsurface temperature measurements for April 1992 - March 1995, and compared with moored bouy and research vessel current measurements.

  19. High temperature and current density induced degradation of multi-layer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Baoming; Haque, M. A., E-mail: mah37@psu.edu [Mechanical and Nuclear Engineering, The Pennsylvania State University, 314, Leonhard Building, University Park, Pennsylvania 16802 (United States); Mag-isa, Alexander E.; Kim, Jae-Hyun [Korea Institute of Machinery and Materials, 156 Gajungbuk-ro, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Lee, Hak-Joo [Korea Institute of Machinery and Materials, 156 Gajungbuk-ro, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Center for Advanced Meta-Materials (CAMM), 156 Gajungbuk-ro, Yuseong-gu, Daejeon 305-343 (Korea, Republic of)

    2015-10-19

    We present evidence of moderate current density, when accompanied with high temperature, promoting migration of foreign atoms on the surface of multi-layer graphene. Our in situ transmission electron microscope experiments show migration of silicon atoms at temperatures above 800 °C and current density around 4.2 × 10{sup 7} A/cm{sup 2}. Originating from the micro-machined silicon structures that clamp the freestanding specimen, the atoms are observed to react with the carbon atoms in the multi-layer graphene to produce silicon carbide at temperatures of 900–1000 °C. In the absence of electrical current, there is no migration of silicon and only pyrolysis of polymeric residue is observed.

  20. Is Current CMBR Temperature: The Scale Independent Quantum Gravitational Result of Black Hole Cosmology?

    Science.gov (United States)

    Seshavatharam, U. V. S.; Lakshminarayana, S.

    If one is willing to consider the current cosmic microwave back ground temperature as a quantum gravitational effect of the evolving primordial cosmic black hole (universe that constitutes dynamic space-time and exhibits quantum behavior) automatically general theory of relativity and quantum mechanics can be combined into a `scale independent' true unified model of quantum gravity. By considering the `Planck mass' as the initial mass of the baby Hubble volume, past and current physical and thermal parameters of the cosmic black hole can be understood. Current rate of cosmic black hole expansion is being stopped by the microscopic quantum mechanical lengths. In this new direction authors observed 5 important quantum mechanical methods for understanding the current cosmic deceleration. To understand the ground reality of current cosmic rate of expansion, sensitivity and accuracy of current methods of estimating the magnitudes of current CMBR temperature and current Hubble constant must be improved and alternative methods must be developed. If it is true that galaxy constitutes so many stars, each star constitutes so many hydrogen atoms and light is coming from the excited electron of galactic hydrogen atom, then considering redshift as an index of `whole galaxy' receding may not be reasonable. During cosmic evolution, at any time in the past, in hydrogen atom emitted photon energy was always inversely proportional to the CMBR temperature. Thus past light emitted from older galaxy's excited hydrogen atom will show redshift with reference to the current laboratory data. As cosmic time passes, in future, the absolute rate of cosmic expansion can be understood by observing the rate of increase in the magnitude of photon energy emitted from laboratory hydrogen atom. Aged super novae dimming may be due to the effect of high cosmic back ground temperature. Need of new mathematical methods & techniques, computer simulations, advanced engineering skills seem to be essential

  1. Thermal infrared remote sensing for riverscape analysis of water temperature heterogeneity: current research and future directions

    Science.gov (United States)

    Dugdale, S.; Hannah, D. M.; Malcolm, I.; Bergeron, N.; St-Hilaire, A.

    2016-12-01

    Climate change will increase summer water temperatures in northern latitude rivers. It is likely that this will have a negative impact on fish species such as salmonids, which are sensitive to elevated temperatures. Salmonids currently avoid heat stress by opportunistically using cool water zones that arise from the spatio-temporal mosaic of thermal habitats present within rivers. However, there is a general lack of information about the processes driving this thermal habitat heterogeneity or how these spatio-temporal patterns might vary under climate change. In this paper, we document how thermal infrared imaging has previously been used to better understand the processes driving river temperature patterns. We then identify key knowledge gaps that this technology can help to address in the future. First, we demonstrate how repeat thermal imagery has revealed the role of short-term hydrometeorological variability in influencing longitudinal river temperature patterns, showing that precipitation depth is strongly correlated with the degree of longitudinal temperature heterogeneity. Second, we document how thermal infrared imagery of a large watershed in Eastern Canada has shed new light on the landscape processes driving the spatial distribution of cool water patches, revealing that the distribution of cool patches is strongly linked to channel confinement, channel curvature and the proximity of dry tributary valleys. Finally, we detail gaps in current understanding of spatio-temporal patterns of river temperature heterogeneity. We explain how advances in unmanned aerial vehicle technology and deterministic temperature modelling will be combined to address these current limitations, shedding new light on the landscape processes driving geographical variability in patterns of river temperature heterogeneity. We then detail how such advances will help to identify rivers that will be resilient to future climatic warming, improving current and future strategies for

  2. IR Camera Validation of IGBT Junction Temperature Measurement via Peak Gate Current

    DEFF Research Database (Denmark)

    Baker, Nick; Dupont, Laurent; Munk-Nielsen, Stig

    2017-01-01

    Infra-red measurements are used to assess the measurement accuracy of the Peak Gate Current (IGPeak) method for IGBT junction temperature measurement. Single IGBT chips with the gate pad in both the centre and the edge are investigated, along with paralleled chips, as well as chips suffering part...... between chips, the IGPeak method delivers a measurement based on the average temperature of the gate pads....

  3. High-temperature current conduction through three kinds of Schottky diodes

    Institute of Scientific and Technical Information of China (English)

    Li Fei; Zhang Xiao-Ling; Duan Yi; Xie Xue-Song; Lü Chang-Zhi

    2009-01-01

    Fundamentals of the Schottky contacts and the high-temperature current conduction through three kinds of Schottky diodes are studied. N-Si Schottky diodes, GaN Schottky diodes and AlGaN/GaN Schottky diodes are investigated by I-V-T measurements ranging from 300 to 523 K. For these Schottky diodes, a rise in temperature is accompanied with an increase in barrier height and a reduction in ideality factor. Mechanisms are suggested, including thermionic emission, field emission, trap-assisted tunnelhng and so on. The most remarkable finding in the present paper is that these three kinds of Sehottky diodes are revealed to have different behaviours of high-temperature reverse currents. For the n-Si Sehottky diode, a rise in temperature is accompanied by an increase in reverse current. The reverse current of the GaN Schottky diode decreases first and then increases with rising temperature. The AIGaN/GaN Schottky diode has a trend opposite to that of the GaN Schottky diode, and the dominant mechanisms are the effects of the piezoelectric polarization field and variation of two-dimensional electron gas charge density.

  4. Design of a high-temperature superconductor current lead for electric utility SMES

    Science.gov (United States)

    Niemann, R. C.; Cha, Y. S.; Hull, J. R.; Rey, C. M.; Dixon, K. D.

    Current leads that rely on high-temperature superconductors (HTS's) to deliver power to devices operating at liquid helium temperature have the potential to reduce refrigeration requirements to levels significantly below those achievable with conventional leads. The design of HTS current leads suitable for use in near-term superconducting magnetic energy storage (SMES) is in progress. The SMES system has an 0.5 MWh energy capacity and a discharge power of 30 MW. Lead-design considerations include safety and reliability, electrical and thermal performance, structural integrity, manufacturability, and cost. Available details of the design, including materials, configuration, and performance predictions, are presented.

  5. Molecular characterization and expression of As-nurp1 gene from Artemia sinica during development and in response to salinity and temperature stress.

    Science.gov (United States)

    Li, Qiuying; Zhang, Qiaozhi; Han, Lulu; Yuan, Zhe; Tan, Jian; Du, Bin; Zou, Xiangyang; Hou, Lin

    2012-06-01

    Nuclear protein 1 (NURP1) is a stress-related protein and closely related to diapause in the development of Artemia. In the present paper, the full-length 568-bp cDNA sequence of the nurp1 homolog of Artemia sinica (As-nurp1) was isolated by RACE technology for the first time. The putative As-nurp1 protein consists of 66 amino acids with a basic helix-loop-helix (bHLH) motif and a bipartite nuclear localization signal (NLS). Multiple sequence alignments revealed that the putative As-nurp1 protein sequence was relatively conserved across species, especially in the bHLH domain. The expression of As-nurp1 is widely distributed during A. sinica development. This is followed by a dramatic downregulation after diapause and is newly upregulated from the larval nauplius stage. Furthermore, As-nurp1 transcripts are highly upregulated under conditions of high salinity and low temperature. These findings suggest that As-nurp1 is stress-related and may act as a protective factor in embryonic development.

  6. 海洋次表层FIDW温盐影像插值算法%FIDW algorithm for temperature and salinity image interpolation in sub-surface ocean

    Institute of Scientific and Technical Information of China (English)

    张胜茂; 樊伟

    2012-01-01

    最大限度地提高海洋次表层温盐影像插值速度,是解决渔况信息动态服务效率的关键.IDW可以实现海洋剖面观测点的二维插值,但通用的IDW算法效率较低,采用FIDW方法提高插值效率,在使用相同计算公式的情况下实现影像快速插值,插值结果经过实测数据验证表明误差的范围可以满足渔业分析应用的需要.%Maximizing the efficiency of image temperature and salinity image interpolation in subsurface ocean is the key to solve the dynamic information services in fishing conditions. IDW can observe the marine section of two-dimensional interpolation points, but the common IDW algorithm is less efficient. FIDW interpolation method is used to improve efficiency. It achieves fast image interpolation in the case of using the same formula. The interpolation image is verified by measured data. The result shows that error range can meet the needs of analysis and applications in fisheries.

  7. Current meter and temperature profile data from moored current meter casts in the TOGA area - Atlantic Ocean from 10 September 1970 - 27 October 1980 (NODC Accession 8600320)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter and temperature profile data were collected using moored current meter - PCM casts in the TOGA area - Atlantic Ocean from September 10, 1970 to October...

  8. Current direction and temperature data from moored current meter casts in the Atlantic Ocean from 29 August 1979 - 01 November 1979 (NODC Accession 8200153)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction and temperature data were collected using moored current meter casts in the Atlantic Ocean from August 29, 1979 to November 1, 1979. Data were...

  9. Current direction, temperature, and conductivity data from moored current meter casts in the North Pacific Ocean from 29 April 1981 - 02 December 1981 (NODC Accession 8300030)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and conductivity data were collected using moored current meter casts in the North Pacific Ocean from April 29, 1981 to December 2,...

  10. Current direction and temperature data from moored current meter casts in the Gulf of Mexico from 24 March 1980 - 16 June 1980 (NODC Accession 8200220)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction and temperature data were collected using moored current meter casts in the Gulf of Mexico from March 24, 1980 to June 16, 1980. Data were...

  11. NODC Standard Product: Texas-Louisiana Shelf Circulation and Transport Processes Study: Current Meter, Meteorological Buoy, XBT/XSV/XCP/CTD/IES (NODC Accession 9700319)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This package contains current direction/velocity, water temperature, air temperature, salinity, and other data which were collected using current meter, CTD casts,...

  12. Extreme precipitation and temperature responses to circulation patterns in current climate: statistical approaches

    NARCIS (Netherlands)

    Photiadou, C.

    2015-01-01

    Climate change is likely to influence the frequency of extreme extremes - temperature, precipitation and hydrological extremes, which implies increasing risks for flood and drought events in Europe. In current climate, European countries were often not sufficiently prepared to deal with the great so

  13. Investigation of sounding rocket observations of field-aligned currents and electron temperature

    Science.gov (United States)

    Cohen, I. J.; Lessard, M.; Zettergren, M. D.; Moen, J.; Lynch, K. A.; Heavisides, J. M.

    2014-12-01

    Strangeway et al. [2005] and other authors have concluded that the establishment of the ambipolar field by the deposition of energy from soft electron precipitation is a significant driver of type-2 ion upflows. Likewise, Clemmons et al. [2008] and Zhang et al. [2012] proposed processes by which soft electron precipitation may play a role in heating neutrals and contribute to neutral upwelling. In both situations the thermal ionospheric electron population plays a crucial role in both generation of the ambipolar field and in collisional energy exchange with the atmosphere through a variety of processes. In this study we examine the dynamics of the electron population, specifically the temperature, in a slightly different context - focusing on the auroral downward current region (DCR). In many cases auroral DCRs may be depleted of plasma, which sets up interesting conditions involving thermoelectric heat fluxes (which flow upward - in the opposite direction from the current), adiabatic expansion due to the high (upward) speed of the electrons carrying the downward current, heat exchange from ions which have elevated temperatures due to frictional heating, and direct frictional heating of the electrons. A detailed understanding of the electron temperature in auroral DCRs is necessary to make quantitative statements about recombination, upflow, cavitation and a host of other processes relevant to ion outflow. In this study, we compare in situ rocket observations of electron temperature, density, and current densities with predictions from the Zettergren and Semeter [2012] model in an attempt to better understand the dynamics and relationships between these parameters in DCRs.

  14. Investigation of the Critical Current Density of YBaCuO high-temperature Superconductor Ceramic

    OpenAIRE

    METSKHVARISHVILI, I. R.; KEKELIDZE, N. P.; METSKHVARISHVILI, M. R.

    2002-01-01

    The method of high harmonics is used to investigate penetration of low magnetic fields within the Y1Ba2Cu3O7 high-temperature superconductor ceramic. Given experimental results are explained by the modal dependencies between the value of critical current density and the magnetic induction B: jc(B) = jc(0){\\frac{{B02}} {{B02 + B2}}}.

  15. HTS-FCL EMTDC model considering nonlinear characteristics on fault current and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jae-Young; Lee, Seung-Ryul [Korea Electrotechnology Research Institute (Korea, Republic of)

    2010-06-01

    One of the most serious problems of the KEPCO system is a higher fault current than the CB(Circuit breaker's SCC (Short Circuit Capacity). There are so many alternatives to reduce the higher fault current, such as the isolation of bus ties, enhancement of the CB's SCC, and the application of HVDC-BTB (Back to Back) or FCL (fault current limiter). However, these alternatives have drawbacks from the viewpoint of system stability and cost. As superconductivity technology has been developed, the resistive type (R-type) HTS-FCL (High Temperature Superconductor Fault Current Limiter) offers one of the important alternatives in terms of power loss and cost reduction in solving the fault current problem. To evaluate the accurate transient performance of R-type HTS-FCL, it is necessary for the dynamic simulation model to consider transient characteristics during the quenching and the recovery state. Against this background, this paper presents the new HTS-FCL EMTDC (Electro-Magnetic Transients including Direct Current) model considering the nonlinear characteristics on fault current and temperature.

  16. HTS-FCL EMTDC model considering nonlinear characteristics on fault current and temperature

    Science.gov (United States)

    Yoon, Jae-Young; Lee, Seung-Ryul

    2010-06-01

    One of the most serious problems of the KEPCO system is a higher fault current than the CB(Circuit breaker's SCC (Short Circuit Capacity). There are so many alternatives to reduce the higher fault current, such as the isolation of bus ties, enhancement of the CB's SCC, and the application of HVDC-BTB (Back to Back) or FCL (fault current limiter). However, these alternatives have drawbacks from the viewpoint of system stability and cost. As superconductivity technology has been developed, the resistive type (R-type) HTS-FCL (High Temperature Superconductor Fault Current Limiter) offers one of the important alternatives in terms of power loss and cost reduction in solving the fault current problem. To evaluate the accurate transient performance of R-type HTS-FCL, it is necessary for the dynamic simulation model to consider transient characteristics during the quenching and the recovery state. Against this background, this paper presents the new HTS-FCL EMTDC (Electro-Magnetic Transients including Direct Current) model considering the nonlinear characteristics on fault current and temperature.

  17. Influence of current and temperature on discharge characteristics of electrochemical nickel−cadmium system

    Directory of Open Access Journals (Sweden)

    Todorović Andreja

    2010-01-01

    Full Text Available The paper elaborates determination of characteristic values in the discharging process of non-hermetic nickel-cadmium galvanic battery with nominal voltage Un = 60 V and nominal capacity qn = C5 = 190 Ah and its dependence from current and temperature. Study has been performed with the set of experimental metering of voltages, electromotive force, current from discharge time range and electromotive force in steady state regime before and after battery charging. Electromotive force characteristics are obtained by using the Nernst’s equation, while the least square method was used to determine the average values of internal electrical resistivity, power losses and efficiency level. These results were used in the approximate exponential functions to determine the range dependence of the efficiency level from the internal electrical resistance of discharge current in reliance from the temperature range. Obtained results show that, in accordance to the given voltage variation of 10% Un, this type of battery holds maximal full load current of one hour capacity at the temperature of 25°C and maximal full load current of two hours capacity at the temperature of −30°C. The methodology used in the case study covers determination of the electromotive force in time range based on the metered results of values during complete battery fullness and emptiness with prior determination of equilibrium constants of galvanic battery reaction through method suggested by the author of this paper. Further process, using the electromotive force values obtained through the aforementioned process, the metered current, and approximate polynomial function of the nominal discharge voltage characteristic determines range of battery internal electric resistance from time, followed by the selection of discharge cases with average values for: voltage, electromotive force, internal electrical resistance, available and utilized power, power losses, and battery efficiency

  18. Vortex-lattice pinning and critical current density in anisotropic high-temperature superconductors

    Science.gov (United States)

    Li, Yingxu; Li, Xiangyu; Kang, Guozheng; Gao, Yuanwen

    2016-10-01

    The anisotropy of critical current density is an impressive manifestation in the physics of high-temperature superconductors. We develop an analytical characterization of anisotropic flux-lattice pinning and critical current density in a system of random point defects. The effect of superconducting anisotropy on the pinning force and critical current density is formulated. The in-plane/out-of-plane anisotropy and microscopic characteristic lengths are incorporated in the field and angular dependence of the critical current density. This is helpful in understanding the physical essence of the scaling behavior in the experiments for critical current anisotropy. We discuss the role of strong and weak point defects in the anisotropic flux-lattice pinning. Relevance of the theory to the critical-state model is dictated as well.

  19. Room Temperature Magnetic Determination of the Current Center Line for the ITER TF Coils

    CERN Document Server

    Lerch, Philippe; Buzio, Marco; Negrazus, Marco; Baynham, Elwyn; Sanfilippo, Stephane; Foussat, Arnaud

    2014-01-01

    The ITER tokamak includes 18 superconducting D-shaped toroidal field (IT) coils. Unavoidable shape deformations as well as assembly errors will lead to field errors, which can be modeled with the knowledge of the current center line (CCL). Accurate survey during the entire manufacturing and assembly process, including transfer of survey points, is complex. In order to increase the level of confidence, a room temperature magnetic measurement of the CCL on assembled and closed winding packs is foreseen, prior to insertion into their cold case. In this contribution, we discuss the principle of the CCL determination and present a low frequency ac measurement system under development at PSI, within an ITER framework contract. The largest current allowed to flow in the TF coil at room temperature and the precision requirements for the determination of the CCL loci of the coil are hard boundaries. Eddy currents in the radial plates, the winding pack enclosures, and possibly from iron in the reinforced concrete floor...

  20. Large-scale temperature and salinity changes in the upper Canadian Basin of the Arctic Ocean at a time of a drastic Arctic Oscillation inversion

    Directory of Open Access Journals (Sweden)

    P. Bourgain

    2013-04-01

    Full Text Available Between 2008 and 2010, the Arctic Oscillation index over Arctic regions shifted from positive values corresponding to more cyclonic conditions prevailing during the 4th International Polar Year (IPY period (2007–2008 to extremely negative values corresponding to strong anticyclonic conditions in 2010. In this context, we investigated the recent large-scale evolution of the upper western Arctic Ocean, based on temperature and salinity summertime observations collected during icebreaker campaigns and from ice-tethered profilers (ITPs drifting across the region in 2008 and 2010. Particularly, we focused on (1 the freshwater content which was extensively studied during previous years, (2 the near-surface temperature maximum due to incoming solar radiation, and (3 the water masses advected from the Pacific Ocean into the Arctic Ocean. The observations revealed a freshwater content change in the Canadian Basin during this time period. South of 80° N, the freshwater content increased, while north of 80° N, less freshening occurred in 2010 compared to 2008. This was more likely due to the strong anticyclonicity characteristic of a low AO index mode that enhanced both a wind-generated Ekman pumping in the Beaufort Gyre and a possible diversion of the Siberian River runoff toward the Eurasian Basin at the same time. The near-surface temperature maximum due to incoming solar radiation was almost 1 °C colder in the southern Canada Basin (south of 75° N in 2010 compared to 2008, which contrasted with the positive trend observed during previous years. This was more likely due to higher summer sea ice concentration in 2010 compared to 2008 in that region, and surface albedo feedback reflecting more sun radiation back in space. The Pacific water (PaW was also subjected to strong spatial and temporal variability between 2008 and 2010. In the Canada Basin, both summer and winter PaW signatures were stronger between 75° N and 80° N. This was more likely

  1. Kinetic model of force-free current sheets with non-uniform temperature

    Science.gov (United States)

    Kolotkov, D. Y.; Vasko, I. Y.; Nakariakov, V. M.

    2015-11-01

    The kinetic model of a one-dimensional force-free current sheet (CS) developed recently by Harrison and Neukirch [Phys. Rev. Lett. 102(13), 135003 (2009)] predicts uniform distributions of the plasma temperature and density across the CS. However, in realistic physical systems, inhomogeneities of these plasma parameters may arise quite naturally due to the boundary conditions or local plasma heating. Moreover, as the CS spatial scale becomes larger than the characteristic kinetic scales (the regime often referred to as the MHD limit), it should be possible to set arbitrary density and temperature profiles. Thus, an advanced model has to allow for inhomogeneities of the macroscopic plasma parameters across the CS, to be consistent with the MHD limit. In this paper, we generalise the kinetic model of a force-free current sheet, taking into account the inhomogeneity of the density and temperature across the CS. In the developed model, the density may either be enhanced or depleted in the CS central region. The temperature profile is prescribed by the density profile, keeping the plasma pressure uniform across the CS. All macroscopic parameters, as well as the distribution functions for the protons and electrons, are determined analytically. Applications of the developed model to current sheets observed in space plasmas are discussed.

  2. Practically Saline

    Directory of Open Access Journals (Sweden)

    Jonathan Schroeder MD

    2015-11-01

    Full Text Available Introduction. In December 2014, the Food and Drug Administration issued a recall of all Wallcur simulation products due to reports of their use in clinical practice. We present a case of septic shock and multiorgan failure after the accidental intravenous infusion of a nonsterile Wallcur simulation product. Case. The patient presented with symptoms of rigors and dyspnea occurring immediately after infusion of Wallcur Practi-0.9% saline. Initial laboratory evidence was consistent with severe septic shock and multiorgan dysfunction. His initial lactic acid level was 9 mmol/L (reference range = 0.5-2.2, and he had evidence of acute kidney injury and markers of disseminated intravascular coagulation. All 4 blood culture bottles isolated multidrug-resistant Empedobacter brevis. The patient recovered from his illness and was discharged with ciprofloxacin therapy per susceptibilities. Discussion. This patient represents the first described case of severe septic shock associated with the infusion of a Wallcur simulation product. Intravenous inoculation of a nonsterile fluid is rare and exposes the patient to unusual environmental organisms, toxins, or unsafe fluid characteristics such as tonicity. During course of treatment, we identified the possible culprit to be a multidrug-resistant isolate of Empedobacter brevis. We also discuss the systemic failures that led to this outbreak.

  3. Temperature Distribution and Critical Current of Long HTS Cables Cooled with Subcooled Liquid Nitrogen

    Science.gov (United States)

    Vyatkin, V. S.; Ivanov, Y. V.; Watanabe, H.; Chikumoto, N.; Yamaguchi, S.

    2017-07-01

    Cooling of the long HTS power transmission lines performs by pumping of subcooled liquid nitrogen (LN2) along the cable. The temperature of LN2 along the cable increases due to the heat losses of the cryostat and heat generation in the HTS cable. The experiment using test cable line in Ishikari shows that flow rate of 35 L/min retains increasing of LN2 temperature by 1 K per 1 km of length. The technology when the back flow of LN2 cools the radiation shield surrounding the cable pipe is also applied in Ishikari-2 project. In this case the ambient heat flow into cable pipe is 50 times less than that without radiation shield. Back flow of LN2 removes almost all heat coming from the environment. When transport current is close to the critical value the Joule heat of HTS cable is significant. This heat additionally increases the temperature of LN2 flowing along the HTS cable. Near the outlet the temperature of HTS cable is maximal and the local critical current is minimal. The current matching critical current criterion of average electrical field of E 0 = 10-4 V/m provides the voltage drop and significant Joule heat at the hot end of the cable. It can lead the damage of the cable. The present work contains analysis of temperature distribution along the cable and the way to achieve the fail-safe operation of long HTS cable cooled by subcooled LN2. We also performed extrapolation of obtained results for several times longer cable lines by decreasing the LN2 flow rate.

  4. Temperature dependence of carrier spin polarization determined from current-induced domain wall motion in a Co/Ni nanowire

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, K.; Koyama, T.; Hiramatsu, R.; Kobayashi, K.; Ono, T. [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Chiba, D. [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 322-0012 (Japan); Fukami, S. [Green Innovation Research Laboratories, NEC Corporation, 34 Miyukigaoka, Tsukuba, Ibaraki 305-8501 (Japan); Center for Spintronics Integrated Systems, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Tanigawa, H.; Suzuki, T. [RENESAS Electronics Corporation, Sagamihara, Kanagawa 252-5298 (Japan); Ohshima, N. [NEC Energy Device Ltd., 1120 Shimokuzawa, Chuo-ku, Sagamihara, Kanagawa 252-5298 (Japan); Ishiwata, N. [Green Innovation Research Laboratories, NEC Corporation, 34 Miyukigaoka, Tsukuba, Ibaraki 305-8501 (Japan); Nakatani, Y. [University of Electro-communications, Chofu, Tokyo 182-8585 (Japan)

    2012-05-14

    We have investigated the temperature dependence of the current-induced magnetic domain wall (DW) motion in a perpendicularly magnetized Co/Ni nanowire at various temperatures and with various applied currents. The carrier spin polarization was estimated from the measured domain wall velocity. We found that it decreased more with increasing temperature from 100 K to 530 K than the saturation magnetization did.

  5. Model of phase distribution of hydrophobic organic chemicals in cyclodextrin-water-air-solid sorbent systems as a function of salinity, temperature, and the presence of multiple CDs

    Science.gov (United States)

    Blanford, W. J.

    2013-12-01

    Environmental and other applications of cyclodextrins (CD) often require usage of high concentra- tion aqueous solutions of derivatized CDs. In an effort to reduce the costs, these studies also typically use technical grades where the purity of the CD solution and the degree of substitution has not been reported. Further, this grade of CD often included high levels of salt and it is commonly applied in high salinity systems. The mathematical models for water and air partitioning coefficients of hydrophobic organic chemicals (HOC) with CDs that have been used in these studies under-estimate the level of HOC within CDs. This is because those models (1) do not take into account that high concentrations of CDs result in significantly lower levels of water in solution and (2) they do not account for the reduction in HOC aqueous solubility due to the presence of salt. Further, because they have poor knowledge of the CD molar concentration in their solu- tions, it is difficult to draw comparisons between studies. Herein is developed a mathematical model where cyclo- dextrin is treated as a separate phase whose relative volume is calculated from its apparent molar volume in solution and the CD concentration of the solution. The model also accounts for the affects of temperature and the presence of salt in solution through inclusion of modified versions of the Van't Hoff and Setschenow equations. With these capabilities, additional equations have been developed for calculating HOC phase distribution in air-water-CD-solid sorbent systems for a single HOC and between water and CD for a system containing multiple HOCs as well as multiple types of cyclodextrin.

  6. Anomalous temperature dependence of the current in a metal-oxide-polymer resistive switching diode

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Henrique L; Rocha, Paulo R F; Kiazadeh, Asal [Center of Electronics Optoelectronics and Telecommunications (CEOT) Universidade do Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); De Leeuw, Dago M [Philips Research Laboratories, Professor Holstlaan 4, 5656 AA Eindhoven (Netherlands); Meskers, Stefan C J, E-mail: hgomes@ualg.pt [Molecular Materials and Nanosystems, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2011-01-19

    Metal-oxide polymer diodes exhibit non-volatile resistive switching. The current-voltage characteristics have been studied as a function of temperature. The low-conductance state follows a thermally activated behaviour. The high-conductance state shows a multistep-like behaviour and below 300 K an enormous positive temperature coefficient. This anomalous behaviour contradicts the widely held view that switching is due to filaments that are formed reversibly by the diffusion of metal atoms. Instead, these findings together with small-signal impedance measurements indicate that creation and annihilation of filaments is controlled by filling of shallow traps localized in the oxide or at the oxide/polymer interface.

  7. Temperature dependence of critical current of heterostructures YBCO-STO-LCMO nearly Tc

    CERN Document Server

    Khokhlov, V A; Drobotko, V F; Levchenko, G G; Mikheenko, P N; Chakalov, R; Muirhead, C R

    2003-01-01

    The complex differential susceptibility a pure YBCO film and YBCO-STO-LCMO structures of different STO width (0; 2; 7 nm) is studied. It is shown, that a decrease of superconducting transition temperature T sub o nset and critical current density j sub c is observed, as expected for the structure YBCO-LCMO in comparison with the pure YBCO film. Conversely, the YBCO-STO-LCMO structures display an increase in T sub o nset; as for j sub c , it increases in the structure with 2 nm STO and decreases in that with 7 nm STO. It is suggested the pinning mechanism of vortices undergoes a change with decreasing temperature.

  8. Temperature-dependence of Threshold Current Density-Length Product in Metallization Lines: A Revisit

    Science.gov (United States)

    Saptono Duryat, Rahmat; Kim, Choong-Un

    2016-04-01

    One of the important phenomena in Electromigration (EM) is Blech Effect. The existence of Threshold Current Density-Length Product or EM Threshold has such fundamental and technological consequences in the design, manufacture, and testing of electronics. Temperature-dependence of Blech Product had been thermodynamically established and the real behavior of such interconnect materials have been extensively studied. The present paper reviewed the temperature-dependence of EM threshold in metallization lines of different materials and structure as found in relevant published articles. It is expected that the reader can see a big picture from the compiled data, which might be overlooked when it was examined in pieces.

  9. The tunneling magnetoresistance current dependence on cross sectional area, angle and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. H., E-mail: zhaohui@physics.umanitoba.ca; Bai, Lihui; Hu, C.-M. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, R3T 2N2 Canada (Canada); Hemour, S.; Wu, K. [École Polytechnique de Montréal, Montréal, H3T 1J4 Canada (Canada); Fan, X. L.; Xue, D. S. [The Key Lab for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Houssameddine, D. [Everspin Technologies, 1347 N. Alma School Road, Chandler, Arizona 85224 (United States)

    2015-03-15

    The magnetoresistance of a MgO-based magnetic tunnel junction (MTJ) was studied experimentally. The magnetoresistance as a function of current was measured systematically on MTJs for various MgO cross sectional areas and at various temperatures from 7.5 to 290.1 K. The resistance current dependence of the MTJ was also measured for different angles between the two ferromagnetic layers. By considering particle and angular momentum conservation of transport electrons, the current dependence of magnetoresistance can be explained by the changing of spin polarization in the free magnetic layer of the MTJ. The changing of spin polarization is related to the magnetoresistance, its angular dependence and the threshold current where TMR ratio equals zero. A phenomenological model is used which avoid the complicated barrier details and also describes the data.

  10. The tunneling magnetoresistance current dependence on cross sectional area, angle and temperature

    Directory of Open Access Journals (Sweden)

    Z. H. Zhang

    2015-03-01

    Full Text Available The magnetoresistance of a MgO-based magnetic tunnel junction (MTJ was studied experimentally. The magnetoresistance as a function of current was measured systematically on MTJs for various MgO cross sectional areas and at various temperatures from 7.5 to 290.1 K. The resistance current dependence of the MTJ was also measured for different angles between the two ferromagnetic layers. By considering particle and angular momentum conservation of transport electrons, the current dependence of magnetoresistance can be explained by the changing of spin polarization in the free magnetic layer of the MTJ. The changing of spin polarization is related to the magnetoresistance, its angular dependence and the threshold current where TMR ratio equals zero. A phenomenological model is used which avoid the complicated barrier details and also describes the data.

  11. Low temperature dielectric relaxation of poly (L-lactic acid) (PLLA) by Thermally Stimulated Depolarization Current

    Science.gov (United States)

    Mishra Patidar, Manju; Jain, Deepti; Nath, R.; Ganesan, V.

    2016-10-01

    Poly (L-lactic acid) (PLLA) is a biodegradable and biocompatible polyester that can be produced by renewable resources, like corn. Being non-toxic to human body, PLLA is used in biomedical applications, like surgical sutures, bone fixation devices, or controlled drug delivery. Besides its application studies, very few experiments have been done to study its dielectric relaxation in the low temperature region. Keeping this in mind we have performed a low temperature thermally stimulated depolarization current (TSDC) studies over the temperature range of 80K-400K to understand the relaxation phenomena of PLLA. We could observe a multi modal broad relaxation of small but significant intensity at low temperatures while a sharp and high intense peak around glass transition temperature, Tg∼ 333K, of PLLA has appeared. The fine structure of the low temperature TSDC peak may be attributed to the spherulites formation of crystallite regions inter twinned with the polymer as seen in AFM and appear to be produced due to an isothermal crystallization process. XRD analysis also confirms the semicrystalline nature of the PLLA film.

  12. Performance evaluation of high-temperature superconducting current leads for micro-SMES systems

    Science.gov (United States)

    Niemann, R. C.; Cha, Y. S.; Hull, J. R.; Buckles, W. E.; Weber, B. R.; Yang, S. T.

    As part of the US Department of Energy's Superconductivity Technology Program, Argonne National Laboratory and Superconductivity, Inc., are developing high-temperature superconductor (HTS) current leads for application to micro-superconducting magnetic energy storage systems. Two 1500-A HTS leads have been designed and constructed. The performance of the current lead assemblies is being evaluated in a zero-magnetic-field test program that includes assembly procedures, tooling, and quality assurance; thermal and electrical performance; and flow and mechanical characteristics. Results of evaluations performed to data are presented.

  13. Simulation of Southwest Monsoon Current Circulation and Temperature in the East Coast of Peninsular Malaysia

    DEFF Research Database (Denmark)

    Daryabor, Farshid

    2014-01-01

    This study investigates the southwest monsoon circulation and temperature along the east coast of Peninsular Malaysia by using the Regional Ocean Modeling System at 9 km resolution. The simulated circulation shows strong northward flowing western boundary currents along the east coast of Peninsular...... Malaysia with maximum speed of approximately of 0.6-0.7 ms-1. The western boundary current, that extends to a depth of about 35 m, continues flowing northward up to approximately 7oN where it changes direction eastward. The circulation along the east coast of Peninsular Malaysia is also characterized...

  14. Design, Fabrication and Temperature Sensitivity Testing of a Miniature Piezoelectric-Based Sensor for Current Measurements

    Directory of Open Access Journals (Sweden)

    Steven B. Lao

    2014-07-01

    Full Text Available Grid capacity, reliability, and efficient distribution of power have been major challenges for traditional power grids in the past few years. Reliable and efficient distribution within these power grids will continue to depend on the development of lighter and more efficient sensing units with lower costs in order to measure current and detect failures across the grid. The objective of this paper is to present the development of a miniature piezoelectric-based sensor for AC current measurements in single conductors, which are used in power transmission lines. Additionally presented in this paper are the thermal testing results for the sensor to assess its robustness for various operating temperatures.

  15. Continuous Pressure and Temperature Monitoring in Lower Arbuckle Saline Aquifer in Wellington Field, Sumner County, Kansas - Response to the M5.8 Pawnee Earthquake

    Science.gov (United States)

    Watney, W. L.; Bidgoli, T. S.; Victorine, J.; Simpson, P.; Holubnyak, Y.; Nolte, K.; Tsoflias, G. P.; Wreath, D.; Birdie, T. R.

    2016-12-01

    Since April 2016 a downhole P/T gauge has been continuously recording high-resolution data (1 /sec, 0.7 kP and 0.01 ºC accuracy) in the lower Arbuckle saline aquifer at a depth of 1524 m in the Berexco Wellington KGS #1-28 well. The cased well was perforated and tested in August 2011 and has remained idle since. The wellsite located in south-central Kansas has experienced the introduction of numerous, low magnitude earthquakes since early 2015. The downhole pressure measured at the start of continuous monitoring in April 2016 was 216 kP above pressures measured five years before in August 2011. Pressure has risen at a rate of up to 4.1 kP /mo until 9-1-16, two-days prior to the Pawnee earthquake, after which time, long-term pressure has remained essentially level (mid October 2017). In addition, short-term, multiple, hours-long, asymmetric pressure spikes of up to 345 kP accompanied by temperature falls of 0.3 ºC have been observed. The M5.8 Pawnee earthquake was detected by pressure oscillations (1.4 to 5.5 kP and 0.1 sec freq) coinciding closely with the larger amplitude portion of the earthquake's CODA. Oscillations are attributed local aquifer and wellbore effects from the wave train of the passing earthquake. The validation of a regional pressure field forecasted by simulation of brine disposal by Bidgoli et al. (2016) suggests hydrologic continuity of the regional Arbuckle aquifer and a possible explanation for the observed expansion of the seismicity linked to the pressure field. Short term spikes of pressure increases and temperature falls suggest cooler brine entering casing perforations that accompany the pressure increase. These short term anomalies are attributed to changes in disposal rates and casing pressure of wells in the local vicinity. The leveling off of pressure that occurred 2-days before the Pawnee earthquake may be just a coincidence, but could potentially have occurred either from moving brine from the Arbuckle into another formation or

  16. Note: Demonstration of an external-cavity diode laser system immune to current and temperature fluctuations.

    Science.gov (United States)

    Miao, Xinyu; Yin, Longfei; Zhuang, Wei; Luo, Bin; Dang, Anhong; Chen, Jingbiao; Guo, Hong

    2011-08-01

    We demonstrate an external-cavity laser system using an anti-reflection coated laser diode as gain medium with about 60 nm fluorescence spectrum, and a Rb Faraday anomalous dispersion optical filter (FADOF) as frequency-selecting element with a transmission bandwidth of 1.3 GHz. With 6.4% optical feedback, a single stable longitudinal mode is obtained with a linewidth of 69 kHz. The wavelength of this laser is operating within the center of the highest transmission peak of FADOF over a diode current range from 55 mA to 142 mA and a diode temperature range from 15 °C to 35 °C, thus it is immune to the fluctuations of current and temperature.

  17. Two-dimensional simulations of temperature and current-density distribution in electromigrated structures

    Science.gov (United States)

    Kießig, Birgit; Schäfer, Roland; von Löhneysen, Hilbert

    2014-01-01

    We report on the application of a feedback-controlled electromigration technique for the formation of nanometre-sized gaps in mesoscopic gold wires and rings. The effect of current density and temperature, linked via Joule heating, on the resulting gap size is investigated. Our experiments include in situ measurements of the evolution of the electrical resistance and of the structure of the device during electromigration. Experimentally, a good thermal coupling to the substrate turned out to be crucial to reach electrode spacings below 10 nm and to avoid overall melting of the nanostructures. This finding is supported by numerical calculations of the current-density and temperature profiles for structure layouts subjected to electromigration. The numerical method can be used for optimizing the layout so as to predetermine the location where electromigration leads to the formation of a gap.

  18. Temperature-dependent current-voltage characteristics of niobium SNIS Josephson junctions

    Energy Technology Data Exchange (ETDEWEB)

    Lacquaniti, V; Andreone, D; Cassiago, C; De Leo, N; Fretto, M; Sosso, A [National Institute of Metrological Research, Electromagnetism Division, Strada delle Cacce 91, 10135 Torino (Italy); Belogolovskii, M, E-mail: v.lacquaniti@inrim.i [Donetsk Physical and Technical Institute, National Academy of Sciences of Ukraine, Str. Rosa Luxemburg. 72, 83114 Donetsk (Ukraine)

    2010-06-01

    Motivated by a search for a suitable technology to fabricate Josephson junctions with a tunable damping regime, we performed a systematic study of the temperature effect on the critical current in Nb/Al-AlO{sub x}-Nb heterostructures with a nanometer-thick Al interlayer. For Al layer thicknesses ranging from 40 to 110 nm, we have observed a transition from hysteretic (below 4.2 K) to non-hysteretic (above 4.2 K) current-voltage curves. Measured supercurrent-vs-temperature characteristics which significantly differ from those of traditional SIS and SNS devices are interpreted in terms of the superconducting proximity effect between Al and Nb films. Thermal stability and good reproducibility of our junctions are demonstrated.

  19. Cryoelectrolysis—electrolytic processes in a frozen physiological saline medium

    Science.gov (United States)

    Lugnani, Franco; Macchioro, Matteo

    2017-01-01

    Background Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. Method To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Results Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. Discussion The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that interface. Conclusion

  20. Cryoelectrolysis—electrolytic processes in a frozen physiological saline medium

    Directory of Open Access Journals (Sweden)

    Franco Lugnani

    2017-01-01

    Full Text Available Background Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. Method To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Results Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. Discussion The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that

  1. Electron Cyclotron Current Drive at High Electron Temperature on DIII-D

    Science.gov (United States)

    Petty, C. C.; Austin, M. E.; Harvey, R. W.; Lohr, J.; Luce, T. C.; Makowski, M. A.; Prater, R.

    2007-09-01

    Experiments on DIII-D have measured the electron cyclotron current drive (ECCD) efficiency for co- and counter-injection in low density plasmas with radiation temperatures from electron cyclotron emission (ECE) above 20 keV. The radiation temperature is generally higher than the Thomson scattering temperature, indicating that there is a significant population of non-thermal electrons. The experimental ECCD profile measured with motional Stark effect (MSE) polarimetry is found to agree with quasi-linear theory except for the highest power density cases (QEC/ne2≫1). Radial transport of the energetic electrons with diffusion coefficients of ˜0.4 m2/s is needed to model the broadened ECCD profile at high power density.

  2. High-temperature superconductor current leads for electric utility SMES applications

    Science.gov (United States)

    Niemann, R. C.; Cha, Y. S.; Hull, J. R.; Buckles, W. E.; Weber, B. R.; Dixon, K. D.; Rey, C. M.

    Current leads that utilize high-temperature superconductors (HTSS) to deliver power to devices operating at liquid helium temperature have the potential to reduce refrigeration requirements to levels significantly below those achievable with conventional leads. As part of the US Department of Energy's Superconductivity Technology Program, Argonne National Laboratory and two industrial partners are developing HTS current leads for application to superconducting magnetic energy storage (SMES) systems. Superconductivity, Inc. (SI) is a supplier of micro-SMES systems for power-quality applications. A typical SI SMES system has an 0.3-kWh energy capacity and operates at currents up to 1.2 kA. The Babcock & Wilcox Company (B&W) is engaged in a project to design, build, and demonstrate a midsized SMES system. The B&W system has an 0.5-MWh energy capacity and operates at currents up to 16 kA. Details of the lead designs, including materials, configuration, and performance predictions, are presented.

  3. Thermal stimulated current response in cupric oxide single crystal thin films over a wide temperature range

    Science.gov (United States)

    Yang, Kungan; Wu, Shuxiang; Yu, Fengmei; Zhou, Wenqi; Wang, Yunjia; Meng, Meng; Wang, Gaili; Zhang, Yueli; Li, Shuwei

    2017-01-01

    Cupric oxide single crystal thin films (~26 nm) were grown by plasma-assisted molecular beam epitaxy. X-ray diffraction, Raman spectra and in situ reflection high-energy electron diffraction show that the thin films are 2  ×  2 reconstructed with an in-plane compression and out-of-plane stretching. A thermal stimulated current measurement indicates that the electric polarization response is shown in the special 2D cupric oxide single crystal thin film over a wide temperature range from 130 K to near-room temperature. We infer that the abnormal electric response involves the changing of phase transition temperature induced by structure distortion, the spin frustration and the magnetic fluctuation effect of a short-range magnetic order, or the combined action of both of the two factors mentioned above. This work suggests a promising clue for finding new room temperature single phase multiferroics or tuning phase transition temperatures.

  4. Analysis of the EDIPO Temperature Margin During Current Ramp-Up

    CERN Document Server

    Marinucci, C; Calvi, Marco; Marinucci, Claudio; Cau, Francesca; Bottura, Luca

    2010-01-01

    The European dipole (EDIPO), currently under construction, will provide background magnetic fields of up to 12.5 T for tests of ITER high-current superconducting cables. The EDIPO winding consists of 7 x 2 double layers of Nb3SN cable-in-conduit conductors with forced flow cooling of supercritical helium. The performance limits of EDIPO during current ramp-up are analyzed analysed with the CryoSoft suite of codes, recently integrated into a customizable and flexible environment for the analysis of thermal hydraulic and electrical transients in superconducting magnetic systems. The simultaneous analysis of the cryogenic system and all 14 double layers shows that under all charging conditions the EDIPO temperature margin remains sufficiently high.

  5. The current-voltage and noise properties of high temperature superconductor SNS and grain boundary junctions

    CERN Document Server

    McGordon, A

    1999-01-01

    transport that was dominated by the interlayer material, but supercurrent transport that could be due to pinhole shorts. In addition, both geometries, especially the sandwich junction, showed large amounts of normal state noise making these junctions unsuitable for device applications. The effect of shining laser light onto a junction was investigated. The effects on the I-V characteristic were unobservable with the experimental resolution available. The effect of the light on the critical current noise of the junction was to reduce the noise peak slightly when compared to the unilluminated case- the reduction was of the order of 10%, comparable with experimental resolution. The study of the noise from Josephson Junctions is an intense field of research. Despite this, no clear picture of the current transport in these devices has emerged. Without the detailed understanding of the mechanisms of current transport in High Temperature Superconductor junctions, the design of superconducting electronics will not mo...

  6. Temperature current-voltage characterisation of MOCVD grown InGaN/GaN MQW LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Moldovan, Grigore; Humphreys, Colin J. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Phillips, Andrew [phconsult Ltd., 54 Covent Garden, Cambridge, CB1 2HR (United Kingdom); Thrush, E.J. [Thomas Swan Scientific Equipment Limited, Buckingway Business Park, Cambridge, CB4 5UK (United Kingdom)

    2006-06-15

    A methodology of temperature current-voltage characterisation for blue GaN-based LED is described, with emphasis on artefacts arising from self-heating at high forward currents and voltage transients at low forward currents. Examples of LEDs with Al{sub 2}O{sub 3} and SiC substrates are discussed, with methods of accounting and avoiding these errors. For the devices studied here it is found that tunnelling dominates the charge transport and that two parallel conduction pathways are present. A method of interpretation of extracted data is also presented, in the context of desired device performance. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. The SMOS ocean salinity retrieval algorithm

    Science.gov (United States)

    Font, J.

    2009-04-01

    SMOS (Soil Moisture and Ocean Salinity) will be, from spring 2009, the first space mission attempting the determination of sea surface salinity using microwave L-band radiometry. The SMOS aperture synthesis technique poses strict requirements to instrument calibration and stability for a successful brightness temperature image reconstruction. Besides this, the low sensitivity of Tb to salinity, even at L-band, and the still not fully developed/validated emissivity models at this frequency taking into account all the physical processes that impact on it, mainly the effects of surface roughness, plus the need of removing from the recorded signal the contributions of scattered radiation from external sources (sun, galaxy) result in a really challenging salinity determination by SMOS. In this presentation we review the approach implemented in SMOS for salinity retrieval from the calibrated brightness temperature maps. The different processing steps are summarily described, as well as their implementation status and validation in the SMOS level 2 salinity processor.

  8. Thermal, Electrical, and Optical Measurements of Electrical Discharges in Saline

    Science.gov (United States)

    Moore, Cameron; Ward, Arlen; Sato, Kazunari; Collins, George

    2008-10-01

    We report measurements of electrical discharges in saline that are electrically excited at 100 kHz from a commercial electrosurgical system. Using a one-dimensional thermocouple array, we estimate that these discharges in saline, in contrast to prior work, induce local temperatures > 100 C. Simultaneous measurement of voltage, current, and optical emission of Na* at 589 nm show that these discharges have frequent arcs, and that these arcs dominate energy flow into the saline. Finally we present measurements of Stark splitting of the sodium D1 and D2 resonant emission lines and from these data estimate the thickness of sheath-like region where most of the applied voltage is dropped.

  9. Spatial and temporal variability of soil moisture-temperature coupling in current and future climate

    Science.gov (United States)

    Schwingshackl, Clemens; Hirschi, Martin; Seneviratne, Sonia Isabelle

    2017-04-01

    While climate models generally agree on a future global mean temperature increase, the exact rate of change is still uncertain. The uncertainty is even higher for regional temperature trends that can deviate substantially from the projected global temperature increase. Several studies tried to constrain these regional temperature projections. They found that over land areas soil moisture is an important factor that influences the regional response. Due to the limited knowledge of the influence of soil moisture on atmospheric conditions on global scale the constraint remains still weak, though. Here, we use a framework that is based on the dependence of evaporative fraction (i.e. the fraction of net radiation that goes into latent heat flux) on soil moisture to distinguish between different soil moisture regimes (Seneviratne et al., 2010). It allows to estimate the influence of soil moisture on near-surface air temperature in the current climate and in future projections. While in the wet soil moisture regime, atmospheric conditions and related land surface fluxes can be considered as mostly driven by available energy, in the transitional regime - where evaporative fraction and soil moisture are essentially linearly coupled - soil moisture has an impact on turbulent heat fluxes, air humidity and temperature: Decreasing soil moisture and concomitant decreasing evaporative fraction cause increasing sensible heat flux, which might further lead to higher surface air temperatures. We investigate the strength of the single couplings (soil moisture → latent heat flux → sensible heat flux → air temperature) in order to quantify the influence of soil moisture on surface air temperature in the transitional regime. Moreover, we take into account that the coupling strength can change in the course of the year due to seasonal climate variations. The relations between soil moisture, evaporative fraction and near-surface air temperature in re-analysis and observation

  10. Large-scale temperature and salinity changes in the upper Canadian basin of the Arctic Ocean at a time of a drastic Arctic Oscillation inversion

    Directory of Open Access Journals (Sweden)

    P. Bourgain

    2012-05-01

    Full Text Available Between 2008 and 2010, the Arctic Oscillation index over Arctic regions shifted from positive values corresponding to more cyclonic conditions prevailing during IPY period (2007–2008 to extremely negative values corresponding to strong anticyclonic conditions in 2010. In this context, we investigated the recent large scale evolution of the upper Western Arctic Ocean based on temperature and salinity summertime observations collected during icebreaker campaigns and from Ice-Tethered Platforms (ITP drifting across the region in 2008 and 2010. Particularly, we focused on (1 the freshwater content which was extensively studied during previous years, (2 the Near Surface Temperature Maximum due to incoming solar radiation and (3 the water masses advected from the Pacific and Atlantic Oceans into the deep Arctic Ocean.

    The observations revealed a freshwater content change in the Canadian basin during this time period. South of 80° N, the freshwater content increased, while north of 80° N, less freshening occurred in 2010 compared to 2008. This was more likely due to the strong anticyclonicity characteristic of a low AO index mode that enhanced both a wind-generated Ekman pumping in the Beaufort Gyre and a diversion of the Siberian rivers runoff toward the Eurasian basin at the same time.

    The Near Surface Temperature Maximum due to incoming solar radiation was almost 1 °C colder in the Southern Canada basin (south of 75° N in 2010 compared to 2008 which contrasted with the positive trend observed during previous years. This was more likely due to higher summer sea ice concentration in 2010 compared to 2008 in that region, and surface albedo feedback reflecting more sun radiation back in space.

    The Pacific waters were also subjected to strong spatial and temporal variability between 2008 and 2010. In the Canada basin, both Summer and Winter Pacific waters influence increased between 75° N and 80° N. This was more likely

  11. EOS7Cm: An improved TOUGH2 module for simulating non-isothermal multiphase and multicomponent flow in CO2-H2S-CH4-brine systems with high pressure, temperature and salinity

    Science.gov (United States)

    Lei, Hongwu; Li, Jun; Li, Xiaochun; Jiang, Zhenjiao

    2016-09-01

    Understanding the non-isothermal multiphase and multicomponent flow in a CO2-H2S-CH4-brine system is of critical importance in projects such as CO2 storage in deep saline aquifers, natural gas extraction using CO2 as the displacement fluid, and heat extraction from hot dry rocks using CO2 as the working fluid. Numerical simulation is a necessary tool to evaluate the chemical evolution in these systems. However, an accurate thermodynamic model for CO2-H2S-CH4-brine systems appropriate for high pressure, temperature, and salinity is still lacking. This study establishes the mutual solubility model for CO2-H2S-CH4-brine systems based on the fugacity-activity method for phase equilibrium. The model can predict mutual solubilities for pressure up to 1000 bar for CO2 and CH4, and 200 bar for H2S, for temperature up to 200 °C, and for salinity up to 6 mol/kg water. We incorporated the new model into TOUGH2/EOS7C, forming a new improved module we call EOS7Cm. Compared to the original EOS7C, EOS7Cm considers the effects of H2S and covers a larger range of temperature and salinity. EOS7Cm is employed in five examples, including CO2 injection with and without impurities (CH4 and/or H2S) into deep aquifers, CH4 extraction from aquifers by CO2 injection, and heat extraction from hot dry rock. The results are compared to those from TOUGH2/ECO2N, EOS7C and CMG, agreement among which serves to verify EOS7Cm.

  12. Salinity Gradients for Sustainable Energy: Primer, Progress, and Prospects.

    Science.gov (United States)

    Yip, Ngai Yin; Brogioli, Doriano; Hamelers, Hubertus V M; Nijmeijer, Kitty

    2016-11-15

    Combining two solutions of different composition releases the Gibbs free energy of mixing. By using engineered processes to control the mixing, chemical energy stored in salinity gradients can be harnessed for useful work. In this critical review, we present an overview of the current progress in salinity gradient power generation, discuss the prospects and challenges of the foremost technologies - pressure retarded osmosis (PRO), reverse electrodialysis (RED), and capacitive mixing (CapMix) and provide perspectives on the outlook of salinity gradient power generation. Momentous strides have been made in technical development of salinity gradient technologies and field demonstrations with natural and anthropogenic salinity gradients (for example, seawater-river water and desalination brine-wastewater, respectively), but fouling persists to be a pivotal operational challenge that can significantly ebb away cost-competitiveness. Natural hypersaline sources (e.g., hypersaline lakes and salt domes) can achieve greater concentration difference and, thus, offer opportunities to overcome some of the limitations inherent to seawater-river water. Technological advances needed to fully exploit the larger salinity gradients are identified. While seawater desalination brine is a seemingly attractive high salinity anthropogenic stream that is otherwise wasted, actual feasibility hinges on the appropriate pairing with a suitable low salinity stream. Engineered solutions are foulant-free and can be thermally regenerative for application in low-temperature heat utilization. Alternatively, PRO, RED, and CapMix can be coupled with their analog separation process (reverse osmosis, electrodialysis, and capacitive deionization, respectively) in salinity gradient flow batteries for energy storage in chemical potential of the engineered solutions. Rigorous techno-economic assessments can more clearly identify the prospects of low-grade heat conversion and large-scale energy storage

  13. Enhanced sensitivity of temperature-compensated SAW-based current sensor using the magnetostrictive effect

    Science.gov (United States)

    Wang, Wen; Jia, Yana; Liu, Xinlu; Liang, Yong; Xue, Xufeng; Du, Zaofu

    2017-02-01

    A temperature-compensated surface acoustic wave (SAW)-based current sensor was proposed in this contribution, composed of a sensor chip made by SAW delay line patterns on a SiO2/128° YX LiNbO3 piezoelectric substrate, a magnetostrictive FeCo film deposited on the SAW propagation path, and a corresponding differential oscillation configuration. The FeCo coating produced magnetostrictive strain under the magnetic field generated by the applied current, leading to linearity changes in the SAW propagation in the form of velocity change. The corresponding differential oscillation frequency shift was used to evaluate the tested current. By solving the coupled electromechanical field equation in a layered structure while considering the magnetostrictive effect, the optimal FeCo film thickness, and sensor operation frequency yielding high current sensitivity, were determined, and then confirmed experimentally by evaluating the developed SAW current sensor system utilizing a Helmholtz coil. A high sensitivity of 16.6 KHz A-1 (8.3 KHz m-1 T-1), excellent linearity, and lower detection limit (˜0.2 mA) were achieved with our 300 MHz SAW sensor with a 500 nm FeCo coating and aspect ratio of 2:1.

  14. Current direction, chemical, zooplankton, phytoplankton, and other data from moored current meter casts and other instruments in the Gulf of Mexico during the Brine Disposal project, 24 March 1981 - 03 November 1981 (NODC Accession 8200042)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, salinity, and other data were collected using moored current meter casts and other instruments in the Gulf of Mexico from March 24,...

  15. Current direction, wind wave spectra, phytoplankton, and other data from moored current meter casts in the Gulf of Mexico during the Brine Disposal project, 24 September 1977 - 31 May 1981 (NODC Accession 8100612)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, wind wave spectra, phytoplankton, temperature, salinity, and other data were collected using moored current meter casts in the Gulf of Mexico from...

  16. Quench propagation in High Temperature Superconducting materials integrated in high current leads

    CERN Document Server

    Milani, D

    2001-01-01

    High temperature superconductors (HTS) have been integrated in the high current leads for the Large Hadron Collider (LHC), under construction at CERN, in order to reduce the heat leak into the liquid helium bath due to the joule effect. The use of the HTS technology in the lower part of the current leads allowed to significantly reduce the heat charge on the cryogenic system. Hybrid current leads have been designed to fulfill the LHC requirements with respect to thermal load; several tests have been performed to study the lead behavior especially during a quench transient. Quench experiments have been performed at CERN on 13 kA prototypes to determine the adequate design and protection. In all the tests it is possible to know the temperature profile of the HTS only with the help of quench simulations that model the thermo-hydraulic processes during quench. The development of a theoretical model for the simulation allows reducing the number of test to perform and to scale the experimental result to other curre...

  17. Temperature and current dependent electroluminescence measurements on colour-coded multiple quantum well light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Bergbauer, Werner [OSRAM Opto Semiconductors GmbH, Regensburg (Germany); FH Deggendorf (Germany); Laubsch, Ansgar; Peter, Matthias; Mayer, Tobias; Bader, Stefan; Oberschmid, Raimund; Hahn, Berthold [OSRAM Opto Semiconductors GmbH, Regensburg (Germany); Benstetter, Guenther [FH Deggendorf (Germany)

    2008-07-01

    As the efficiency and the luminous flux have been increased enormously in the last few years, today Light Emitting Diodes (LEDs) are even pushed to applications like general lighting and Home Cinema Projection. Still, InGaN/GaN heterostructure based LEDs suffer from loss-mechanisms like non-radiative defect and Auger recombination, carrier leakage and piezo-field induced carrier separation. To optimize the high current efficiency we evaluated the benefit of Multiple Quantum Well (MQW) compared to Single Quantum Well (SQW) LEDs. Temperature dependent electroluminescence of colour-coded structures with different Indium content in certain Quantum Wells was measured. The experiments demonstrated a strong temperature and current dependence of the MQW operation. The comparison between different LED structures showed effectively the increased LED performance of those structures which operate with a well adjusted MQW active area. Due to the enhanced carrier distribution in the high current range, these LEDs show a higher light output and additionally a reduced wavelength shift.

  18. Experimental investigation of CO{sub 2}-brine-rock interactions at elevated temperature and pressure: Implications for CO{sub 2} sequestration in deep-saline aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Rosenbauer, Robert J.; Koksalan, Tamer; Palandri, James L. [U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 (United States)

    2005-10-15

    Deep-saline aquifers are potential repositories for excess CO{sub 2}, currently being emitted to the atmosphere from anthropogenic activities, but the reactivity of supercritical CO{sub 2} with host aquifer fluids and formation minerals needs to be understood. Experiments reacting supercritical CO{sub 2} with natural and synthetic brines in the presence and absence of limestone and plagioclase-rich arkosic sandstone showed that the reaction of CO{sub 2}-saturated brine with limestone results in compositional, mineralogical, and porosity changes in the aquifer fluid and rock that are dependent on initial brine composition, especially dissolved calcium and sulfate. Experiments reacting CO{sub 2}-saturated, low-sulfate brine with limestone dissolved 10% of the original calcite and increased rock porosity by 2.6%. Experiments reacting high-sulfate brine with limestone, both in the presence and absence of supercritical CO{sub 2}, were characterized by the precipitation of anhydrite, dolomitization of the limestone, and a final decrease in porosity of 4.5%. However, based on favorable initial porosity changes of about 15% due to the dissolution of calcite, the combination of CO{sub 2} co-injection with other mitigation strategies might help alleviate some of the well-bore scale and formation-plugging problems near the injection zone of a brine disposal well in Paradox Valley, Colorado, as well as provide a repository for CO{sub 2}. Experiments showed that the solubility of CO{sub 2} is enhanced in brine in the presence of limestone by 9% at 25 {sup o}C and 6% at 120 {sup o}C and 200 bar relative to the brine itself. The solubility of CO{sub 2} is enhanced also in brine in the presence of arkosic sandstone by 5% at 120 {sup o}C and 300 bar. The storage of CO{sub 2} in limestone aquifers is limited to only ionic and hydraulic trapping. However, brine reacted with supercritical CO{sub 2} and arkose yielded fixation and sequestration of CO{sub 2} in carbonate mineral phases

  19. Eddy-Induced Ekman Pumping from Sea-Surface Temperature and Surface Current Effects

    Science.gov (United States)

    Gaube, P.; Chelton, D. B.; O'Neill, L. W.

    2011-12-01

    Numerous past studies have discussed the biological importance of upwelling of nutrients into the interiors of nonlinear eddies. Such upwelling can occur during the transient stages of formation of cyclones from shoaling of the thermocline. In their mature stages, upwelling can occur from Ekman pumping driven by eddy-induced wind stress curl. Previous investigations of ocean-atmosphere interaction in regions of persistent sea-surface temperature (SST) frontal features have shown that the wind field is locally stronger over warm water and weaker over cold water. Spatial variability of the SST field thus results in a wind stress curl and an associated Ekman pumping in regions of crosswind temperature gradients. It can therefore be anticipated that any SST anomalies associated with eddies can generate Ekman pumping in the eddy interiors. Another mechanism for eddy-induced Ekman pumping is the curl of the stress on the sea surface that arises from the difference between the surface wind velocity and the surface ocean velocity. While SST-induced Ekman upwelling can occur over eddies of either polarity surface current effects on Ekman upwelling occur only over anticyclonic eddies The objective of this study is to determine the spatial structures and relative magnitudes of the two mechanisms for eddy-induced Ekman pumping within the interiors of mesoscale eddies. This is achieved by collocating satellite-based measurements of SST, surface winds and wind stress curl to the interiors of eddies identified and tracked with an automated procedure applied to the sea-surface height (SSH) fields in the Reference Series constructed by AVISO from the combined measurements by two simultaneously operating altimeters. It is shown that, on average, the wind stress curl from eddy-induced surface currents is largest at the eddy center, resulting in Ekman pumping velocities of order 10 cm day-1. While this surface current-induced Ekman pumping depends only weakly on the wind direction

  20. Low temperature and moisture effects on polarization and depolarization currents of oil-paper insulation

    Energy Technology Data Exchange (ETDEWEB)

    Fofana, I.; Hemmatjou, H. [Canada Research Chair on Insulating Liquids and Mixed Dielectrics for Electrotechnology (ISOLIME), Universite du Quebec a Chicoutimi, 555 Boulevard de l' universite G7H 2B1, Chicoutimi, Qc (Canada); International Research Centre on Atmospheric Icing and Power Network Engineering (CenGivre), Universite du Quebec a Chicoutimi, 555 Boulevard de l' universite G7H 2B1, Chicoutimi, Qc (Canada); Farzaneh, M. [International Research Centre on Atmospheric Icing and Power Network Engineering (CenGivre), Universite du Quebec a Chicoutimi, 555 Boulevard de l' universite G7H 2B1, Chicoutimi, Qc (Canada)

    2010-01-15

    In the last decades, dielectric testing techniques are being used and investigated as potential tools for condition assessment of oil-paper insulation. From fields and laboratory investigations these techniques were found to be highly operating conditions (moisture, ageing, temperature, etc.) dependant. Because field measurements (generally performed after de-energizing the transformer), last hours after de-energizing the transformer, the ambient temperature may affect the results. Especially in cold regions of the world, extreme care is required to interpret the results when performing tests at surrounding low temperatures. A better understanding and analysis of the dielectric test results are therefore only possible with a clear understanding of the physical behaviour of the insulation system in response to the ambient conditions. In the current research project, a series of experiments have been performed under controlled laboratory conditions with preset moisture content inside the insulation. This paper reports the effects of low temperature on the time domain dielectric response of oil impregnated paper insulation. (author)