Science.gov

Sample records for cooling water assimilated

  1. Cooling Water Intakes

    EPA Pesticide Factsheets

    Industries use large volumes of water for cooling. The water intakes pull large numbers of fish and other organisms into the cooling systems. EPA issues regulations on intake structures in order to minimize adverse environmental impacts.

  2. Cooling water distribution system

    DOEpatents

    Orr, Richard

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

  3. Water cooled steam jet

    DOEpatents

    Wagner, Jr., Edward P.

    1999-01-01

    A water cooled steam jet for transferring fluid and preventing vapor lock, or vaporization of the fluid being transferred, has a venturi nozzle and a cooling jacket. The venturi nozzle produces a high velocity flow which creates a vacuum to draw fluid from a source of fluid. The venturi nozzle has a converging section connected to a source of steam, a diffuser section attached to an outlet and a throat portion disposed therebetween. The cooling jacket surrounds the venturi nozzle and a suction tube through which the fluid is being drawn into the venturi nozzle. Coolant flows through the cooling jacket. The cooling jacket dissipates heat generated by the venturi nozzle to prevent vapor lock.

  4. Water cooled steam jet

    DOEpatents

    Wagner, E.P. Jr.

    1999-01-12

    A water cooled steam jet for transferring fluid and preventing vapor lock, or vaporization of the fluid being transferred, has a venturi nozzle and a cooling jacket. The venturi nozzle produces a high velocity flow which creates a vacuum to draw fluid from a source of fluid. The venturi nozzle has a converging section connected to a source of steam, a diffuser section attached to an outlet and a throat portion disposed there between. The cooling jacket surrounds the venturi nozzle and a suction tube through which the fluid is being drawn into the venturi nozzle. Coolant flows through the cooling jacket. The cooling jacket dissipates heat generated by the venturi nozzle to prevent vapor lock. 2 figs.

  5. WATER COOLED RETORT COVER

    DOEpatents

    Ash, W.J.; Pozzi, J.F.

    1962-05-01

    A retort cover is designed for use in the production of magnesium metal by the condensation of vaporized metal on a collecting surface. The cover includes a condensing surface, insulating means adjacent to the condensing surface, ind a water-cooled means for the insulating means. The irrangement of insulation and the cooling means permits the magnesium to be condensed at a high temperature and in massive nonpyrophoric form. (AEC)

  6. Water Cooled Mirror Design

    SciTech Connect

    Dale, Gregory E.; Holloway, Michael Andrew; Pulliam, Elias Noel

    2015-03-30

    This design is intended to replace the current mirror setup being used for the NorthStar Moly 99 project in order to monitor the target coupon. The existing setup has limited movement for camera alignment and is difficult to align properly. This proposed conceptual design for a water cooled mirror will allow for greater thermal transfer between the mirror and the water block. It will also improve positioning of the mirror by using flexible vacuum hosing and a ball head joint capable of a wide range of motion. Incorporating this design into the target monitoring system will provide more efficient cooling of the mirror which will improve the amount of diffraction caused by the heating of the mirror. The process of aligning the mirror for accurate position will be greatly improved by increasing the range of motion by offering six degrees of freedom.

  7. Thermoelectrically cooled water trap

    DOEpatents

    Micheels, Ronald H.

    2006-02-21

    A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

  8. Water-Cooled Optical Thermometer

    NASA Technical Reports Server (NTRS)

    Menna, A. A.

    1987-01-01

    Water-cooled optical probe measures temperature of nearby radiating object. Intended primarily for use in silicon-growing furnace for measuring and controlling temperatures of silicon ribbon, meniscus, cartridge surfaces, heaters, or other parts. Cooling water and flushing gas cool fiber-optic probe and keep it clean. Fiber passes thermal radiation from observed surface to measuring instrument.

  9. Ozonation of cooling tower waters

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; French, K. R.; Howe, R. D. (Inventor)

    1979-01-01

    Continuous ozone injection into water circulating between a cooling tower and heat exchanger with heavy scale deposits inhibits formation of further deposits, promotes flaking of existing deposits, inhibits chemical corrosion and controls algae and bacteria.

  10. Data Assimilation to Estimate the Water Level of River

    NASA Astrophysics Data System (ADS)

    Apriliani, Erna; Hanafi, Lukman; Imron, Chairul

    2017-09-01

    Data assimilation is an estimation method for stochastic dynamic system by combining the mathematical model with measurement data. Water level and velocity of river are stochastic dynamic system, and it is important to estimate the water level and velocity of river flow to reduce flood risk disaster. Here, we estimate the water level and velocity of river flow by using data assimilation specially Kalman filter and Ensemble Kalman filter. We define mathematical model of river flow, discretize and do simulation by Kalman filter and Ensemble Kalman filter. In data assimilation, we forecast the water level and velocity by using mathematical model and based on the measurement data, the correction of forecasting is made.

  11. 18 CFR 420.44 - Cooling water.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Cooling water. 420.44 Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water...

  12. 18 CFR 420.44 - Cooling water.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Cooling water. 420.44 Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water...

  13. 18 CFR 420.44 - Cooling water.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Cooling water. 420.44 Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water...

  14. 18 CFR 420.44 - Cooling water.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Cooling water. 420.44 Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water...

  15. 18 CFR 420.44 - Cooling water.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Cooling water. 420.44 Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water...

  16. Assimilation of Gridded GRACE Terrestrial Water Storage Estimates in the North American Land Data Assimilation System

    NASA Technical Reports Server (NTRS)

    Kumar, Sujay V.; Zaitchik, Benjamin F.; Peters-Lidard, Christa D.; Rodell, Matthew; Reichle, Rolf; Li, Bailing; Jasinski, Michael; Mocko, David; Getirana, Augusto; De Lannoy, Gabrielle; hide

    2016-01-01

    The objective of the North American Land Data Assimilation System (NLDAS) is to provide best available estimates of near-surface meteorological conditions and soil hydrological status for the continental United States. To support the ongoing efforts to develop data assimilation (DA) capabilities for NLDAS, the results of Gravity Recovery and Climate Experiment (GRACE) DA implemented in a manner consistent with NLDAS development are presented. Following previous work, GRACE terrestrial water storage (TWS) anomaly estimates are assimilated into the NASA Catchment land surface model using an ensemble smoother. In contrast to many earlier GRACE DA studies, a gridded GRACE TWS product is assimilated, spatially distributed GRACE error estimates are accounted for, and the impact that GRACE scaling factors have on assimilation is evaluated. Comparisons with quality-controlled in situ observations indicate that GRACE DA has a positive impact on the simulation of unconfined groundwater variability across the majority of the eastern United States and on the simulation of surface and root zone soil moisture across the country. Smaller improvements are seen in the simulation of snow depth, and the impact of GRACE DA on simulated river discharge and evapotranspiration is regionally variable. The use of GRACE scaling factors during assimilation improved DA results in the western United States but led to small degradations in the eastern United States. The study also found comparable performance between the use of gridded and basin averaged GRACE observations in assimilation. Finally, the evaluations presented in the paper indicate that GRACE DA can be helpful in improving the representation of droughts.

  17. Assimilation of Gridded GRACE Terrestrial Water Storage Estimates in the North American Land Data Assimilation System

    NASA Technical Reports Server (NTRS)

    Kumar, Sujay V.; Zaitchik, Benjamin F.; Peters-Lidard, Christa D.; Rodell, Matthew; Reichle, Rolf; Li, Bailing; Jasinski, Michael; Mocko, David; Getirana, Augusto; De Lannoy, Gabrielle; Cosh, Michael H.; Hain, Christopher R.; Anderson, Martha; Arsenault, Kristi R.; Xia, Youlong; Ek, Michael

    2016-01-01

    The objective of the North American Land Data Assimilation System (NLDAS) is to provide best available estimates of near-surface meteorological conditions and soil hydrological status for the continental United States. To support the ongoing efforts to develop data assimilation (DA) capabilities for NLDAS, the results of Gravity Recovery and Climate Experiment (GRACE) DA implemented in a manner consistent with NLDAS development are presented. Following previous work, GRACE terrestrial water storage (TWS) anomaly estimates are assimilated into the NASA Catchment land surface model using an ensemble smoother. In contrast to many earlier GRACE DA studies, a gridded GRACE TWS product is assimilated, spatially distributed GRACE error estimates are accounted for, and the impact that GRACE scaling factors have on assimilation is evaluated. Comparisons with quality-controlled in situ observations indicate that GRACE DA has a positive impact on the simulation of unconfined groundwater variability across the majority of the eastern United States and on the simulation of surface and root zone soil moisture across the country. Smaller improvements are seen in the simulation of snow depth, and the impact of GRACE DA on simulated river discharge and evapotranspiration is regionally variable. The use of GRACE scaling factors during assimilation improved DA results in the western United States but led to small degradations in the eastern United States. The study also found comparable performance between the use of gridded and basin averaged GRACE observations in assimilation. Finally, the evaluations presented in the paper indicate that GRACE DA can be helpful in improving the representation of droughts.

  18. Water-cooled nuclear reactor

    SciTech Connect

    Braun, W.; Irion, L.

    1981-07-07

    A water-cooled nuclear reactor pressure vessel is internally provided with a check valve assembly for the inner end of a coolant inlet nozzle to prevent immediate loss of the coolant from the vessel by backward flow in the event the pressure of the coolant supply through the nozzle, drops below the pressure inside the vessel while the reactor is operating. The valve assembly includes a plurality of flap valves working in parallel so that if one fails to close when required, the balance of the flap valves remain operative to check the discharge of the coolant.

  19. Passive containment cooling water distribution device

    DOEpatents

    Conway, Lawrence E.; Fanto, Susan V.

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using a series of radial guide elements and cascading weir boxes to collect and then distribute the cooling water into a series of distribution areas through a plurality of cascading weirs. The cooling water is then uniformly distributed over the curved surface by a plurality of weir notches in the face plate of the weir box.

  20. District cooling in Stockholm using sea water

    SciTech Connect

    Fermbaeck, G.

    1995-12-31

    In May this year Stockholm Energi started supplying properties in central Stockholm with cooling for comfort and for various processes from its new district cooling system. The project is unique in that most of the cooling energy is produced using cold water from the Baltic Sea. The following article describes the system and provides a summary of the considerations that resulted in venturing to invest in sea-water cooling for such a large project. There is also a description of the hydrological conditions that made the system feasible in Stockholm and some speculations about the possibilities to use cooled sea water elsewhere in the world.

  1. Water cooled static pressure probe

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas T. (Inventor); Eves, John W. (Inventor); Reece, Garland D. (Inventor); Geissinger, Steve L. (Inventor)

    1991-01-01

    An improved static pressure probe containing a water cooling mechanism is disclosed. This probe has a hollow interior containing a central coolant tube and multiple individual pressure measurement tubes connected to holes placed on the exterior. Coolant from the central tube symmetrically immerses the interior of the probe, allowing it to sustain high temperature (in the region of 2500 F) supersonic jet flow indefinitely, while still recording accurate pressure data. The coolant exits the probe body by way of a reservoir attached to the aft of the probe. The pressure measurement tubes are joined to a single, larger manifold in the reservoir. This manifold is attached to a pressure transducer that records the average static pressure.

  2. Feasibility assessment of vacuum cooling followed by immersion vacuum cooling on water-cooked pork.

    PubMed

    Dong, Xiaoguang; Chen, Hui; Liu, Yi; Dai, Ruitong; Li, Xingmin

    2012-01-01

    Vacuum cooling followed by immersion vacuum cooling was designed to cool water-cooked pork (1.5±0.05 kg) compared with air blast cooling (4±0.5°C, 2 m/s), vacuum cooling (10 mbar) and immersion vacuum cooling. This combined cooling method was: vacuum cooling to an intermediate temperature of 25°C and then immersion vacuum cooling with water of 10°C to the final temperature of 10°C. It was found that the cooling loss of this combined cooling method was significantly lower (P<0.05) than those of air blast cooling and vacuum cooling. This combined cooling was faster (P<0.05) than air blast cooling and immersion vacuum cooling in terms of cooling rate. Moreover, the pork cooled by combined cooling method had significant differences (P<0.05) in water content, color and shear force.

  3. Injected Water Augments Cooling In Turboshaft Engine

    NASA Technical Reports Server (NTRS)

    Biesiadny, Thomas J.; Berger, Brett; Klann, Gary A.; Clark, David A.

    1989-01-01

    Report describes experiments in which water injected into compressor-bleed cooling air of aircraft turboshaft engine. Injection of water previously suggested as way to provide additional cooling needed to sustain operation at power levels higher than usual. Involves turbine-inlet temperatures high enough to shorten lives of first-stage high-pressure turbine blades. Latent heat of vaporization of injected water serves as additional heat sink to maintain blades at design operating temperatures during high-power operation.

  4. Injected Water Augments Cooling In Turboshaft Engine

    NASA Technical Reports Server (NTRS)

    Biesiadny, Thomas J.; Berger, Brett; Klann, Gary A.; Clark, David A.

    1989-01-01

    Report describes experiments in which water injected into compressor-bleed cooling air of aircraft turboshaft engine. Injection of water previously suggested as way to provide additional cooling needed to sustain operation at power levels higher than usual. Involves turbine-inlet temperatures high enough to shorten lives of first-stage high-pressure turbine blades. Latent heat of vaporization of injected water serves as additional heat sink to maintain blades at design operating temperatures during high-power operation.

  5. "Hot" for Warm Water Cooling

    SciTech Connect

    IBM Corporation; Energy Efficient HPC Working Group; Hewlett Packard Corporation; SGI; Cray Inc.; Intel Corporation; U.S. Army Engineer Research Development Center; Coles, Henry; Ellsworth, Michael; Martinez, David J.; Bailey, Anna-Maria; Banisadr, Farhad; Bates, Natalie; Coghlan, Susan; Cowley, David E.; Dube, Nicholas; Fields, Parks; Greenberg, Steve; Iyengar, Madhusudan; Kulesza, Peter R.; Loncaric, Josip; McCann, Tim; Pautsch, Greg; Patterson, Michael K.; Rivera, Richard G.; Rottman, Greg K.; Sartor, Dale; Tschudi, William; Vinson, Wade; Wescott, Ralph

    2011-08-26

    Liquid cooling is key to reducing energy consumption for this generation of supercomputers and remains on the roadmap for the foreseeable future. This is because the heat capacity of liquids is orders of magnitude larger than that of air and once heat has been transferred to a liquid, it can be removed from the datacenter efficiently. The transition from air to liquid cooling is an inflection point providing an opportunity to work collectively to set guidelines for facilitating the energy efficiency of liquid-cooled High Performance Computing (HPC) facilities and systems. The vision is to use non-compressor-based cooling, to facilitate heat re-use, and thereby build solutions that are more energy-efficient, less carbon intensive and more cost effective than their air-cooled predecessors. The Energy Efficient HPC Working Group is developing guidelines for warmer liquid-cooling temperatures in order to standardize facility and HPC equipment, and provide more opportunity for reuse of waste heat. This report describes the development of those guidelines.

  6. Cooling water for SSC experiments: Supplemental Conceptual Design Report (SCDR)

    SciTech Connect

    Doyle, R.E.

    1989-10-20

    This paper discusses the following topics on cooling water design on the superconducting super collider; low conductivity water; industrial cooling water; chilled water systems; and radioactive water systems. (LSP)

  7. Air and water cooled modulator

    DOEpatents

    Birx, Daniel L.; Arnold, Phillip A.; Ball, Don G.; Cook, Edward G.

    1995-01-01

    A compact high power magnetic compression apparatus and method for delivering high voltage pulses of short duration at a high repetition rate and high peak power output which does not require the use of environmentally unacceptable fluids such as chlorofluorocarbons either as a dielectric or as a coolant, and which discharges very little waste heat into the surrounding air. A first magnetic switch has cooling channels formed therethrough to facilitate the removal of excess heat. The first magnetic switch is mounted on a printed circuit board. A pulse transformer comprised of a plurality of discrete electrically insulated and magnetically coupled units is also mounted on said printed board and is electrically coupled to the first magnetic switch. The pulse transformer also has cooling means attached thereto for removing heat from the pulse transformer. A second magnetic switch also having cooling means for removing excess heat is electrically coupled to the pulse transformer. Thus, the present invention is able to provide high voltage pulses of short duration at a high repetition rate and high peak power output without the use of environmentally unacceptable fluids and without discharging significant waste heat into the surrounding air.

  8. Air and water cooled modulator

    DOEpatents

    Birx, D.L.; Arnold, P.A.; Ball, D.G.; Cook, E.G.

    1995-09-05

    A compact high power magnetic compression apparatus and method are disclosed for delivering high voltage pulses of short duration at a high repetition rate and high peak power output which does not require the use of environmentally unacceptable fluids such as chlorofluorocarbons either as a dielectric or as a coolant, and which discharges very little waste heat into the surrounding air. A first magnetic switch has cooling channels formed therethrough to facilitate the removal of excess heat. The first magnetic switch is mounted on a printed circuit board. A pulse transformer comprised of a plurality of discrete electrically insulated and magnetically coupled units is also mounted on said printed board and is electrically coupled to the first magnetic switch. The pulse transformer also has cooling means attached thereto for removing heat from the pulse transformer. A second magnetic switch also having cooling means for removing excess heat is electrically coupled to the pulse transformer. Thus, the present invention is able to provide high voltage pulses of short duration at a high repetition rate and high peak power output without the use of environmentally unacceptable fluids and without discharging significant waste heat into the surrounding air. 9 figs.

  9. Data assimilation with soil water content sensors and pedotransfer functions in soil water flow modeling

    USDA-ARS?s Scientific Manuscript database

    Soil water flow models are based on a set of simplified assumptions about the mechanisms, processes, and parameters of water retention and flow. That causes errors in soil water flow model predictions. Soil water content monitoring data can be used to reduce the errors in models. Data assimilation (...

  10. Water-Cooled Total-Temperature Probe

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas T.; Reece, Garland D.

    1992-01-01

    Water-cooled supersonic total-pressure, static-pressure, and total-temperature probes developed to study high-temperature jet plumes. Total-temperature probe tested up to 2,000 degrees F incorporates annular cooling system up to thermocouple lead. Lead extends into test chamber to sense temperature of supersonic external flow. Design novel and significant. Applicable in development of jet engines and in research on fast flows of hot gases.

  11. Alternative water treatment for cooling towers

    SciTech Connect

    Wilsey, C.A.

    1997-04-01

    Problems commonly found in cooling towers include: calcium scale formation, corrosion, algae and bacterial growth. These problems can inhibit a cooling tower from operating at its most efficient capacity. An energy-saving, cost-efficient method to control each of these problems in tower water will ultimately benefit the owner as well as the environment. Supplemental ionic water purification was developed to overcome the disadvantages associates with a total chemical disinfection system. The concept of supplemental ionic water purification was developed in the early 1900s and later reviewed by NASA in the mid-1960`s. Only in the past seven years have biologists combined copper ions with chlorine to act as a bactericide. The findings have shown that metal compound ions (copper), when absorbed by bacteria, affect the organisms enzyme balance. This combination inhibits the organism`s reproduction and respiration capabilities. This technology has been applied to cooling tower operations as an alternative to a chemical-only regimen.

  12. Investigation of assimilable organic carbon (AOC) in flemish drinking water.

    PubMed

    Polanska, Monika; Huysman, Koen; van Keer, Chris

    2005-06-01

    The aim of the study was to investigate the drinking water supplied to majority of residents of Flanders in Belgium. Over 500 water samples were collected from different locations, after particular and complete treatment procedure to evaluate the efficiency of each treatment step in production of biologically stable drinking water. In this study assimilable organic carbon (AOC) was of our interest and was assumed as a parameter responsible for water biostability. The influence of seasons and temperature changes on AOC content was also taken into account. The AOC in most of the non-chlorinated product water of the studied treatment plants could not meet the biostability criteria of 10 mug/l, resulting in the mean AOC concentration of 50 microg/l. However, majority of the examined chlorinated water samples were consistent with proposed criteria of 50--100 microg/l for systems maintaining disinfectant residual. Here, mean AOC concentration of 72 microg/l was obtained. Granular activated carbon filtration was helpful in diminishing AOC content of drinking water; however, the nutrient removal was enhanced by biological process incorporated into water treatment (biological activated carbon filtration). Disinfection by means of chlorination and ozonation increased the water AOC concentration while the ultraviolet irradiation showed no impact on the AOC content. Examination of seasonal AOC variations showed similar fluctuations in six units with the highest values in summer and lowest in winter.

  13. Assimilation of gridded GRACE terrestrial water storage estimates in the North American Land Data Assimilation System

    USDA-ARS?s Scientific Manuscript database

    The objective of the North American Land Data Assimilation System (NLDAS) is to provide best-available estimates of near surface meteorological conditions and soil hydrological status for the Continental United States. The first two phases of NLDAS, however, have not included the assimilation of rem...

  14. What can data assimilation do for water quality forecasting?

    NASA Astrophysics Data System (ADS)

    Kim, S.; Riazi, H.; Seo, D. J.; Shin, C.; Kim, K.

    2014-12-01

    Proactive water quality management through preventive actions requires predictive information. Water quality forecasting can provide such information, e.g., to protect public health from harmful water quality conditions such as algal blooms or bacterial pollution and to allow the decision makers to respond more quickly to emergency situations such as oil spills for protection of water resources systems. Operational water quality forecasting is a large challenge due to the complexities and large uncertainties associated with various physiobiochemical processes involved. As such, there is an added impetus to utilize real-time observations effectively in the forecast process. In this work, we apply data assimilation (DA) to the Hydrologic Simulation Program - Fortran (HSPF) model to improve accuracy of watershed water quality forecast. The DA technique used is based on maximum likelihood ensemble filter (MLEF).The resulting DA module, MLEF-HSPF, has been implemented in the Water Quality Forecast System at the National Institute of Environmental Research (WQFS-NIER) in Korea. In this presentation, we describe MLEF-HSPF, share multi-catchment evaluation results for the Nakdong River Basin in Korea, and identify science and operational challenges.

  15. Development of a rapid assimilable organic carbon method for water.

    PubMed

    Lechevallier, M W; Shaw, N E; Kaplan, L A; Bott, T L

    1993-05-01

    A rapid method for measurement of assimilable organic carbon (AOC) is proposed. The time needed to perform the assay is reduced by increasing the incubation temperature and increasing the inoculum density. The ATP luciferin-luciferase method quickly enumerates the test organisms without the need for plate count media or dilution bottles. There was no significant difference between AOC values determined with strain P17 for the ATP and plate count procedures. For strain NOX, the plate count procedure underestimated bacterial levels in some samples. Comparison of AOC values obtained by the Belleville laboratory (by the ATP technique) and the Stroud Water Research Center (by plate counts) showed that values were significantly correlated and not significantly different. The study concludes that the rapid AOC method can quickly determine the bacterial growth potential of water within 2 to 4 days.

  16. Evaporative cooling of speleothem drip water

    PubMed Central

    Cuthbert, M. O.; Rau, G. C.; Andersen, M. S.; Roshan, H.; Rutlidge, H.; Marjo, C. E.; Markowska, M.; Jex, C. N.; Graham, P. W.; Mariethoz, G.; Acworth, R. I.; Baker, A.

    2014-01-01

    This study describes the first use of concurrent high-precision temperature and drip rate monitoring to explore what controls the temperature of speleothem forming drip water. Two contrasting sites, one with fast transient and one with slow constant dripping, in a temperate semi-arid location (Wellington, NSW, Australia), exhibit drip water temperatures which deviate significantly from the cave air temperature. We confirm the hypothesis that evaporative cooling is the dominant, but so far unattributed, control causing significant disequilibrium between drip water and host rock/air temperatures. The amount of cooling is dependent on the drip rate, relative humidity and ventilation. Our results have implications for the interpretation of temperature-sensitive, speleothem climate proxies such as δ18O, cave microecology and the use of heat as a tracer in karst. Understanding the processes controlling the temperature of speleothem-forming cave drip waters is vital for assessing the reliability of such deposits as archives of climate change. PMID:24895139

  17. Cooling tower water conditioning study. [using ozone

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; French, K. R.

    1979-01-01

    Successful elimination of cooling tower treatment chemicals was demonstrated. Three towers functioned for long periods of time with ozone as the only treatment for the water. The water in the systems was reused as much as 30 times (cycles of concentration) without deleterious effects to the heat exchangers. Actual system blow-down was eliminated and the only makeup water added was that required to replace the evaporation and mist entrainment losses. Minimum water savings alone are approximately 75.1 1/kg/year. Cost estimates indicate that a savings of 55 percent was obtained on the systems using ozone. A major problem experienced in the use of ozone for cooling tower applications was the difficulty of accurate concentration measurements. The ability to control the operational characteristics relies on easily and accurately determined concentration levels. Present methods of detection are subject to inaccuracies because of interfering materials and the rapid destruction of the ozone.

  18. Evaporative cooling of speleothem drip water

    NASA Astrophysics Data System (ADS)

    Cuthbert, M. O.; Rau, G. C.; Andersen, M. S.; Roshan, H.; Rutlidge, H.; Marjo, C. E.; Markowska, M.; Jex, C. N.; Graham, P. W.; Mariethoz, G.; Acworth, R. I.; Baker, A.

    2014-06-01

    This study describes the first use of concurrent high-precision temperature and drip rate monitoring to explore what controls the temperature of speleothem forming drip water. Two contrasting sites, one with fast transient and one with slow constant dripping, in a temperate semi-arid location (Wellington, NSW, Australia), exhibit drip water temperatures which deviate significantly from the cave air temperature. We confirm the hypothesis that evaporative cooling is the dominant, but so far unattributed, control causing significant disequilibrium between drip water and host rock/air temperatures. The amount of cooling is dependent on the drip rate, relative humidity and ventilation. Our results have implications for the interpretation of temperature-sensitive, speleothem climate proxies such as δ18O, cave microecology and the use of heat as a tracer in karst. Understanding the processes controlling the temperature of speleothem-forming cave drip waters is vital for assessing the reliability of such deposits as archives of climate change.

  19. Water cooling of HVDC thyristor valves

    SciTech Connect

    Lips, H.P. )

    1994-10-01

    It is generally accepted that water is a very effective medium to remove heat losses from any type of equipment. When used for HVDC thyristor valves, the fundamentals of electrolyte conduction and water chemistry need to be considered in the design of the cooling circuit. The characteristics of the materials used, in conjunction with high voltage stresses and circuit configuration, play an important role to assure longevity and corrosion-free performance.

  20. [Body cooling capacity of water circulated cooling pants during lower body exercise in a hot environment].

    PubMed

    Tsutsui, Takao; Idota, Nozomi; Nagano, Chikage; Horie, Seichi; Sogabe, Yasuhiro; Monji, Koichi

    2005-03-01

    We investigated the body cooling capacity of water-circulated cooling pants during lower body exercise in a hot environment. Five subjects were asked to ride a bicycle ergometer and to keep a work rate of 75 W continuously for 20 minutes. They then rest on the ergometer for 15 minutes, in a climate chamber kept at WBGT = 31.5 degrees C. They repeated the same procedure three times under three different conditions; 1) wearing cooling pants with cold water supply; 2) wearing cooling pants without water supply; 3) wearing short pants instead of cooling pants. Esophageal temperature and heart rate of the subjects, when their cooling pants were supplied with cold water, were lower compared with the condition without water supply, and were almost the same as the condition wearing short pants. Water-circulated cooling pants should effectively cool the body at work where the worker has to wear pants that cover his legs to prevent injury.

  1. Assimilation of GRACE Terrestrial Water Storage Data into a Land Surface Model

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; Zaitchik, Benjamin F.; Rodell, Matt

    2008-01-01

    The NASA Gravity Recovery and Climate Experiment (GRACE) system of satellites provides observations of large-scale, monthly terrestrial water storage (TWS) changes. In. this presentation we describe a land data assimilation system that ingests GRACE observations and show that the assimilation improves estimates of water storage and fluxes, as evaluated against independent measurements. The ensemble-based land data assimilation system uses a Kalman smoother approach along with the NASA Catchment Land Surface Model (CLSM). We assimilated GRACE-derived TWS anomalies for each of the four major sub-basins of the Mississippi into the Catchment Land Surface Model (CLSM). Compared with the open-loop (no assimilation) CLSM simulation, assimilation estimates of groundwater variability exhibited enhanced skill with respect to measured groundwater. Assimilation also significantly increased the correlation between simulated TWS and gauged river flow for all four sub-basins and for the Mississippi River basin itself. In addition, model performance was evaluated for watersheds smaller than the scale of GRACE observations, in the majority of cases, GRACE assimilation led to increased correlation between TWS estimates and gauged river flow, indicating that data assimilation has considerable potential to downscale GRACE data for hydrological applications. We will also describe how the output from the GRACE land data assimilation system is now being prepared for use in the North American Drought Monitor.

  2. Assimilation of GRACE Terrestrial Water Storage Data into a Land Surface Model

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; Zaitchik, Benjamin F.; Rodell, Matt

    2008-01-01

    The NASA Gravity Recovery and Climate Experiment (GRACE) system of satellites provides observations of large-scale, monthly terrestrial water storage (TWS) changes. In. this presentation we describe a land data assimilation system that ingests GRACE observations and show that the assimilation improves estimates of water storage and fluxes, as evaluated against independent measurements. The ensemble-based land data assimilation system uses a Kalman smoother approach along with the NASA Catchment Land Surface Model (CLSM). We assimilated GRACE-derived TWS anomalies for each of the four major sub-basins of the Mississippi into the Catchment Land Surface Model (CLSM). Compared with the open-loop (no assimilation) CLSM simulation, assimilation estimates of groundwater variability exhibited enhanced skill with respect to measured groundwater. Assimilation also significantly increased the correlation between simulated TWS and gauged river flow for all four sub-basins and for the Mississippi River basin itself. In addition, model performance was evaluated for watersheds smaller than the scale of GRACE observations, in the majority of cases, GRACE assimilation led to increased correlation between TWS estimates and gauged river flow, indicating that data assimilation has considerable potential to downscale GRACE data for hydrological applications. We will also describe how the output from the GRACE land data assimilation system is now being prepared for use in the North American Drought Monitor.

  3. 50. NORTHERN VIEW OF NONEVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. NORTHERN VIEW OF NON-EVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS IN CENTER, AND EVAPORATIVE WASTE WATER COOLING TOWERS ON RIGHT. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  4. Water cooling in induction heating furnaces

    SciTech Connect

    Lazcano-Navarro, A; Lazcano-Ponce, A.; Arellano-Valdes, R.

    1993-08-17

    An induction heated horizontal continuous casting device is described, comprising in combination a tundish opening for receiving steel, an inductor section for inductively maintaining steel temperature, a heating coil externally disposed about the inductor section, a refractory sleeve joint forming a discharge channel for removing liquid steel from the inductor, a water cooled coil array disposed about the inductor and a set of magnetic field insulator surrounding the coil.

  5. Soil moisture assimilation using a modified ensemble transform Kalman filter with water balance constraint

    NASA Astrophysics Data System (ADS)

    Wu, Guocan; Zheng, Xiaogu; Dan, Bo

    2016-04-01

    The shallow soil moisture observations are assimilated into Common Land Model (CoLM) to estimate the soil moisture in different layers. The forecast error is inflated to improve the analysis state accuracy and the water balance constraint is adopted to reduce the water budget residual in the assimilation procedure. The experiment results illustrate that the adaptive forecast error inflation can reduce the analysis error, while the proper inflation layer can be selected based on the -2log-likelihood function of the innovation statistic. The water balance constraint can result in reducing water budget residual substantially, at a low cost of assimilation accuracy loss. The assimilation scheme can be potentially applied to assimilate the remote sensing data.

  6. Bacterial community structure in cooling water and biofilm in an industrial recirculating cooling water system.

    PubMed

    Wang, Jinmei; Liu, Min; Xiao, Huijie; Wu, Wei; Xie, Meijuan; Sun, Mengjia; Zhu, Chenglin; Li, Pengfu

    2013-01-01

    Microbial fouling is a serious problem in open recirculating cooling water systems. The bacterial communities that cause it have not been fully understood. In this study, we analyzed the community structure of free-living bacteria and particle-attached bacteria in cooling water, and bacteria in biofilm collected from the wall of the water reservoir in an industrial recirculating cooling water system by construction of a 16S rRNA gene clone library. Based on amplified ribosomal DNA restriction analysis, clones of all three libraries were clustered into 45 operational taxonomic units (OTUs). Thirteen OTUs displaying 91-96% sequence similarity to a type strain might be novel bacterial species. Noted differences in community structure were observed among the three libraries. The relative species richness of the free-living bacteria in cooling water was much lower than that of particle-attached bacteria and bacteria in biofilm. The majority of the free-living bacterial community (99.0%) was Betaproteobacteria. The predominant bacteria in the particle-attached bacterial community were Alphaproteobacteria (20.5%), Betaproteobacteria (27.8%) and Planctomycetes (42.0%), while those in the biofilm bacterial community were Alphaproteobacteria (47.9%), Betaproteobacteria (11.7%), Acidobacteria (13.1%) and Gemmatimonadetes (11.3%). To control microbial fouling in industrial recirculating cooling water systems, additional physiological and ecological studies of these species will be essential.

  7. 40 CFR 401.14 - Cooling water intake structures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Cooling water intake structures. 401.14... AND STANDARDS GENERAL PROVISIONS § 401.14 Cooling water intake structures. The location, design, construction and capacity of cooling water intake structures of any point source for which a standard...

  8. 40 CFR 401.14 - Cooling water intake structures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Cooling water intake structures. 401.14... AND STANDARDS GENERAL PROVISIONS § 401.14 Cooling water intake structures. The location, design, construction and capacity of cooling water intake structures of any point source for which a standard...

  9. 40 CFR 401.14 - Cooling water intake structures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Cooling water intake structures. 401.14... AND STANDARDS GENERAL PROVISIONS § 401.14 Cooling water intake structures. The location, design, construction and capacity of cooling water intake structures of any point source for which a standard...

  10. 40 CFR 401.14 - Cooling water intake structures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Cooling water intake structures. 401... GUIDELINES AND STANDARDS GENERAL PROVISIONS § 401.14 Cooling water intake structures. The location, design, construction and capacity of cooling water intake structures of any point source for which a standard...

  11. 40 CFR 401.14 - Cooling water intake structures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Cooling water intake structures. 401.14... AND STANDARDS GENERAL PROVISIONS § 401.14 Cooling water intake structures. The location, design, construction and capacity of cooling water intake structures of any point source for which a standard...

  12. Review of High Temperature Water and Steam Cooled Reactor Concepts

    SciTech Connect

    Oka, Yoshiaki

    2002-07-01

    This review summarizes design concepts of supercritical-pressure water cooled reactors (SCR), nuclear superheaters and steam cooled fast reactors from 1950's to the present time. It includes water moderated supercritical steam cooled reactor, SCOTT-R and SC-PWR of Westinghouse, heavy water moderated light water cooled SCR of GE, SCLWR and SCFR of the University of Tokyo, B-500SKDI of Kurchatov Institute, CANDU -X of AECL, nuclear superheaters of GE, subcritical-pressure steam cooled FBR of KFK and B and W, Supercritical-pressure steam cooled FBR of B and W, subcritical-pressure steam cooled high converter by Edlund and Schultz and subcritical-pressure water-steam cooled FBR by Alekseev. This paper is prepared based on the previous review of SCR2000 symposium, and some author's comments are added. (author)

  13. Heat dissipation in water-cooled reflectors

    NASA Technical Reports Server (NTRS)

    Kozai, Toyoki

    1994-01-01

    The energy balance of a lamp varies with the thermal and optical characteristics of the reflector. The photosynthetic radiation efficiency of lamps, defined as input power divided by photosynthetically active radiation (PAR, 400-700 nm) emitted from the lamp ranges between 0.17 and 0.26. The rest of the energy input is wasted as longwave (3000 nm and over) and non-PAR shortwave radiation (from 700 nm to 3000 nm), convective, and conductive heat from the lamp, reflector, and ballast, and simply for increasing the cooling load. Furthermore, some portion of the PAR is uselessly absorbed by the inner walls, shelves, vessels, etc. and some portion of the PAR received by the plantlets is converted into sensible and latent heat. More than 98% of the energy input is probably converted into heat, with only less than 2% of the energy input being converted into chemical energy as carbohydrates by photosynthesis. Therefore, it is essential to reduce the generation of heat in the culture room in order to reduce the cooling load. Through use of a water-cooled reflector, the generation of convective and conductive heat and longwave radiation from the reflector can be reduced, without reduction of PAR.

  14. Satellite-Scale Snow Water Equivalent Assimilation into a High-Resolution Land Surface Model

    NASA Technical Reports Server (NTRS)

    De Lannoy, Gabrielle J.M.; Reichle, Rolf H.; Houser, Paul R.; Arsenault, Kristi R.; Verhoest, Niko E.C.; Paulwels, Valentijn R.N.

    2009-01-01

    An ensemble Kalman filter (EnKF) is used in a suite of synthetic experiments to assimilate coarse-scale (25 km) snow water equivalent (SWE) observations (typical of satellite retrievals) into fine-scale (1 km) model simulations. Coarse-scale observations are assimilated directly using an observation operator for mapping between the coarse and fine scales or, alternatively, after disaggregation (re-gridding) to the fine-scale model resolution prior to data assimilation. In either case observations are assimilated either simultaneously or independently for each location. Results indicate that assimilating disaggregated fine-scale observations independently (method 1D-F1) is less efficient than assimilating a collection of neighboring disaggregated observations (method 3D-Fm). Direct assimilation of coarse-scale observations is superior to a priori disaggregation. Independent assimilation of individual coarse-scale observations (method 3D-C1) can bring the overall mean analyzed field close to the truth, but does not necessarily improve estimates of the fine-scale structure. There is a clear benefit to simultaneously assimilating multiple coarse-scale observations (method 3D-Cm) even as the entire domain is observed, indicating that underlying spatial error correlations can be exploited to improve SWE estimates. Method 3D-Cm avoids artificial transitions at the coarse observation pixel boundaries and can reduce the RMSE by 60% when compared to the open loop in this study.

  15. Establishing the Framework for Land Data Assimilation of GRACE Terrestrial Water Storage Information

    NASA Astrophysics Data System (ADS)

    Sakumura, C.; Bettadpur, S. V.; Yang, Z. L.; Save, H.; McCullough, C.

    2015-12-01

    Assimilation of terrestrial water storage (TWS) data from the Gravity Recovery and Climate Experiment (GRACE) mission into current land surface models can correct model deficiencies due to errors in the model structure, atmospheric forcing datasets, parameters, etc. However, the assimilation process is complicated by spatial and temporal resolution discrepancies between the model and observational datasets, characterization of the error in each, and limitations of the algorithms used to calculate and update the model state. This study aims to establish a framework for hydrological data assimilation with GRACE. GRACE is an independent and accurate but coarse resolution terrestrial water storage dataset. While the models cannot attain the accuracy of GRACE, they are effective in interpretation and downscaling of the product and providing continuity over space and time. Accurate assimilation of GRACE TWS into LSMs thus will take the best characteristics of each and create a combined product that outperforms each individual source. More specifically, this framework entails a comprehensive analysis of the deficiencies and potential improvements of the satellite data products, the assimilation procedures and error characterization, and assimilation effectiveness. A daily sliding window mascon GRACE TWS product, presented previously, was developed to reduce smoothing in time and space during assimilation into the Community Land Model 4.0. The Ensemble Kalman Filter assimilation algorithms are analyzed and adapted for use with the new products, GRACE error information, and model characteristics. Additional assimilation tools such as Gaspari-Cohn localization and ensemble inflation are implemented and tuned for the model and observation properties. Analysis of the observational data, model data, sensitivity and effectiveness of the assimilation routines, and the assimilated results is done through regional comparison with independent in-situ datasets and external model

  16. Electrochemistry of Water-Cooled Nuclear Reactors

    SciTech Connect

    Macdonald, Dgiby; Urquidi-Macdonald, Mirna; Pitt, Jonathan

    2006-08-08

    This project developed a comprehensive mathematical and simulation model for calculating thermal hydraulic, electrochemical, and corrosion parameters, viz. temperature, fluid flow velocity, pH, corrosion potential, hydrogen injection, oxygen contamination, stress corrosion cracking, crack growth rate, and other important quantities in the coolant circuits of water-cooled nuclear power plants, including both Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). The model is being used to assess the three major operational problems in Pressurized Water Reactors (PWR), which include mass transport, activity transport, and the axial offset anomaly, and provide a powerful tool for predicting the accumulation of SCC damage in BWR primary coolant circuits as a function of operating history. Another achievement of the project is the development of a simulation tool to serve both as a training tool for plant operators and as an engineering test-bed to evaluate new equipment and operating strategies (normal operation, cold shut down and others). The development and implementation of the model allows us to estimate the activity transport or "radiation fields" around the primary loop and the vessel, as a function of the operating parameters and the water chemistry.

  17. Towards Improved Snow Water Equivalent Estimation via GRACE Assimilation

    NASA Technical Reports Server (NTRS)

    Forman, Bart; Reichle, Rofl; Rodell, Matt

    2011-01-01

    Passive microwave (e.g. AMSR-E) and visible spectrum (e.g. MODIS) measurements of snow states have been used in conjunction with land surface models to better characterize snow pack states, most notably snow water equivalent (SWE). However, both types of measurements have limitations. AMSR-E, for example, suffers a loss of information in deep/wet snow packs. Similarly, MODIS suffers a loss of temporal correlation information beyond the initial accumulation and final ablation phases of the snow season. Gravimetric measurements, on the other hand, do not suffer from these limitations. In this study, gravimetric measurements from the Gravity Recovery and Climate Experiment (GRACE) mission are used in a land surface model data assimilation (DA) framework to better characterize SWE in the Mackenzie River basin located in northern Canada. Comparisons are made against independent, ground-based SWE observations, state-of-the-art modeled SWE estimates, and independent, ground-based river discharge observations. Preliminary results suggest improved SWE estimates, including improved timing of the subsequent ablation and runoff of the snow pack. Additionally, use of the DA procedure can add vertical and horizontal resolution to the coarse-scale GRACE measurements as well as effectively downscale the measurements in time. Such findings offer the potential for better understanding of the hydrologic cycle in snow-dominated basins located in remote regions of the globe where ground-based observation collection if difficult, if not impossible. This information could ultimately lead to improved freshwater resource management in communities dependent on snow melt as well as a reduction in the uncertainty of river discharge into the Arctic Ocean.

  18. Soil moisture and total water storage changes assimilation at global scale

    NASA Astrophysics Data System (ADS)

    Han, X.; Hendricks Franssen, H. J.; Montzka, C.; Vereecken, H.

    2016-12-01

    The global water cycle estimation with land surface models is affected by uncertainties in the model input data, model parameters and model physics. Data assimilation has the potential to improve model estimation by incorporating multivariate measurements. In this study, we investigated the assimilation of soil moisture and total water storage changes in the community land model (CLM), at the global scale. As the first step, the global land surface states were estimated by the Community Land Mode version 4.5 (CLM) for the period 2009-2010. These simulations were driven by CRU_NCEP reanalysis data at 0.5o spatial resolution. In a second step, the different combinations of soil moisture and total water storage changes data were assimilated into CLM using the local ensemble transform Kalman filter. The daily remote sensing soil moisture product of the climate changes initiative from the European Space Agency and monthly total water storage changes of GRACE from the National Aeronautics and Space Administration were used as the observation data to be assimilated. The CLM uncertainties were represented by 20 ensemble members on the basis of perturbed atmospheric forcing data and soil properties. The results show that the latent heat flux was improved compared with FLUXNET data in the tropical region by assimilating soil moisture or total water storage changes. Assimilation of soil moisture alone could not improve the latent heat flux estimation on average, probably related to the microwave band at which the soil moisture content was measured. The best results were obtained for the univariate assimilation of total water storage changes. The bivariate assimilation of soil moisture and total water storage changes did not improve the results further.

  19. Selective Brain Cooling Reduces Water Turnover in Dehydrated Sheep

    PubMed Central

    Strauss, W. Maartin; Hetem, Robyn S.; Mitchell, Duncan; Maloney, Shane K.; Meyer, Leith C. R.; Fuller, Andrea

    2015-01-01

    In artiodactyls, arterial blood destined for the brain can be cooled through counter-current heat exchange within the cavernous sinus via a process called selective brain cooling. We test the hypothesis that selective brain cooling, which results in lowered hypothalamic temperature, contributes to water conservation in sheep. Nine Dorper sheep, instrumented to provide measurements of carotid blood and brain temperature, were dosed with deuterium oxide (D2O), exposed to heat for 8 days (40◦C for 6-h per day) and deprived of water for the last five days (days 3 to 8). Plasma osmolality increased and the body water fraction decreased over the five days of water deprivation, with the sheep losing 16.7% of their body mass. Following water deprivation, both the mean 24h carotid blood temperature and the mean 24h brain temperature increased, but carotid blood temperature increased more than did brain temperature resulting in increased selective brain cooling. There was considerable inter-individual variation in the degree to which individual sheep used selective brain cooling. In general, sheep spent more time using selective brain cooling, and it was of greater magnitude, when dehydrated compared to when they were euhydrated. We found a significant positive correlation between selective brain cooling magnitude and osmolality (an index of hydration state). Both the magnitude of selective brain cooling and the proportion of time that sheep spent selective brain cooling were negatively correlated with water turnover. Sheep that used selective brain cooling more frequently, and with greater magnitude, lost less water than did conspecifics using selective brain cooling less efficiently. Our results show that a 50kg sheep can save 2.6L of water per day (~60% of daily water intake) when it employs selective brain cooling for 50% of the day during heat exposure. We conclude that selective brain cooling has a water conservation function in artiodactyls. PMID:25675092

  20. Selective brain cooling reduces water turnover in dehydrated sheep.

    PubMed

    Strauss, W Maartin; Hetem, Robyn S; Mitchell, Duncan; Maloney, Shane K; Meyer, Leith C R; Fuller, Andrea

    2015-01-01

    In artiodactyls, arterial blood destined for the brain can be cooled through counter-current heat exchange within the cavernous sinus via a process called selective brain cooling. We test the hypothesis that selective brain cooling, which results in lowered hypothalamic temperature, contributes to water conservation in sheep. Nine Dorper sheep, instrumented to provide measurements of carotid blood and brain temperature, were dosed with deuterium oxide (D2O), exposed to heat for 8 days (40 ◦C for 6-h per day) and deprived of water for the last five days (days 3 to 8). Plasma osmolality increased and the body water fraction decreased over the five days of water deprivation, with the sheep losing 16.7% of their body mass. Following water deprivation, both the mean 24h carotid blood temperature and the mean 24h brain temperature increased, but carotid blood temperature increased more than did brain temperature resulting in increased selective brain cooling. There was considerable inter-individual variation in the degree to which individual sheep used selective brain cooling. In general, sheep spent more time using selective brain cooling, and it was of greater magnitude, when dehydrated compared to when they were euhydrated. We found a significant positive correlation between selective brain cooling magnitude and osmolality (an index of hydration state). Both the magnitude of selective brain cooling and the proportion of time that sheep spent selective brain cooling were negatively correlated with water turnover. Sheep that used selective brain cooling more frequently, and with greater magnitude, lost less water than did conspecifics using selective brain cooling less efficiently. Our results show that a 50 kg sheep can save 2.6L of water per day (~60% of daily water intake) when it employs selective brain cooling for 50% of the day during heat exposure. We conclude that selective brain cooling has a water conservation function in artiodactyls.

  1. Influence of detergents on water drift in cooling towers

    NASA Astrophysics Data System (ADS)

    Vitkovicova, Rut

    An influence of detergents on the water drift from the cooling tower was experimentally investigated. For this experimental measurements was used a model cooling tower, especially an experimental aerodynamic line, which is specially designed for the measurement and monitoring of processes taking place around the eliminators of the liquid phase. The effect of different concentrations of detergent in the cooling water on the drift of water droplets from a commonly used type eliminator was observed with visualization methods.

  2. Influence of detergents on water drift in cooling towers

    NASA Astrophysics Data System (ADS)

    Vitkovicova, Rut

    2016-11-01

    An influence of detergents on the water drift from the cooling tower was experimentally investigated. For this experimental measurements was used a model cooling tower, especially an experimental aerodynamic line, which is specially designed for the measurement and monitoring of processes taking place around the eliminators of the liquid phase. The effect of different concentrations of detergent in the cooling water on the drift of water droplets from a commonly used type eliminator was observed with visualization methods.

  3. Alternative cooling tower water treatment methods

    SciTech Connect

    Wilsey, C.A.

    1996-11-01

    The factors that contribute to proper water balance include total alkalinity, calcium hardness, and pH. In order to keep the cooling tower from scaling or corroding, a manipulation of these components is often necessary. This has traditionally been achieved with the use of chemicals, including but not limited to the following: acid, soda ash, sodium bicarbonate, calcium bicarbonate, algicide, and bactericide. Extensive research has shown that a balanced water system can also be achieved by using the proper combination of copper with a known halogen. Microbiologists have determined that a small amount of copper, acting as a supplement to chlorine at 0.4 ppm, has the same efficiency as 2.0 ppm free chlorine. Therefore, by using the following combination of components and procedures, the desired results can still be achieved: production of copper compound ions as a supplement to the chemical regimen; analysis and manipulation of make-up water; the use of copper as a coagulant for reduction of scale; copper as a supplemental bacterial disinfectant; and copper as an algicide.

  4. SSDA code to apply data assimilation in soil water flow modeling: Documentation and user manual

    USDA-ARS?s Scientific Manuscript database

    Soil water flow models are based on simplified assumptions about the mechanisms, processes, and parameters of water retention and flow. That causes errors in soil water flow model predictions. Data assimilation (DA) with the ensemble Kalman filter (EnKF) corrects modeling results based on measured s...

  5. Water distribution characteristics of spray nozzles in a cooling tower

    NASA Astrophysics Data System (ADS)

    Vitkovic, Pavol

    2015-05-01

    Water distribution characteristics of spray nozzles with spray plates used to distribute cooling water to the cooling fills in a cooling tower is one of the important parameters for the selection of nozzles. Water distribution characteristic describes the distribution of water from the axis of the nozzle along a fill. One of the parameters affecting the water distribution characteristic of the nozzle is airflow velocity of counter flow airstream. Water distribution characteristics are commonly measured using by a set of containers. The problem with this method of the measurement of characteristics is block of the airflow with collections of containers. Therefore, this work is using the visualization method.

  6. Effect of Precipitable Water Vapor Amount on Radiative Cooling Performance

    NASA Astrophysics Data System (ADS)

    Hu, Mingke; Zhao, Bin; Ao, Xianze; Pei, Gang

    2017-05-01

    A radiative cooler based on aluminum-evaporated polyvinyl-fluoride surface was employed to investigate the effect of precipitable water vapor amount on its radiative cooling performance. A mathematic model of steady heat transfer that considers the spectral radiant distribution of the sky, the transparent cover and the collecting surface was established. The results indicate that the amount of precipitable water vapor shows a remarkable and negative effect on radiative cooling performance of the radiative cooler. Both the temperature difference between the cooler and surroundings and the net radiative cooling power decrease as the precipitable water vapor amount increases. The net radiative cooling power drops by about 41.0% as the the precipitable water vapor amount changes from 1.0 cm to 7.0 cm. Besides, the radiative cooler shows better cooling performance in winter than in summer. The net radiative cooling power in summer of Hefei is about 82.2% of that in winter.

  7. Use of nanofiltration to reduce cooling tower water usage.

    SciTech Connect

    Sanchez, Andres L.; Everett, Randy L.; Jensen, Richard Pearson; Cappelle, Malynda A.; Altman, Susan Jeanne

    2010-09-01

    Nanofiltration (NF) can effectively treat cooling-tower water to reduce water consumption and maximize water usage efficiency of thermoelectric power plants. A pilot is being run to verify theoretical calculations. A side stream of water from a 900 gpm cooling tower is being treated by NF with the permeate returning to the cooling tower and the concentrate being discharged. The membrane efficiency is as high as over 50%. Salt rejection ranges from 77-97% with higher rejection for divalent ions. The pilot has demonstrated a reduction of makeup water of almost 20% and a reduction of discharge of over 50%.

  8. Use of nanofiltration to reduce cooling tower water consumption.

    SciTech Connect

    Altman, Susan Jeanne; Ciferno, Jared

    2010-10-01

    Nanofiltration (NF) can effectively treat cooling-tower water to reduce water consumption and maximize water usage efficiency of thermoelectric power plants. A pilot is being run to verify theoretical calculations. A side stream of water from a 900 gpm cooling tower is being treated by NF with the permeate returning to the cooling tower and the concentrate being discharged. The membrane efficiency is as high as over 50%. Salt rejection ranges from 77-97% with higher rejection for divalent ions. The pilot has demonstrated a reduction of makeup water of almost 20% and a reduction of discharge of over 50%.

  9. Membrane evaporative cooling to 30 degrees C or less: 1. Membrane evaporative cooling of contained water.

    PubMed

    Loeb, Sidney

    2003-03-01

    Microporous hydrophobic membranes have been examined for possible use as containers in the evaporative cooling of water, particularly in desert climates. An experimental determination was made of the overall heat and mass transfer coefficients of these membranes while surmounting contained water and with air flowing over the surface of the membranes. Similar tests were made with water alone, that is, without a membrane. The coefficients were then used to compare the performance of existing (canvas water) coolers and membrane evaporative coolers under desert conditions. The performance of the membrane coolers was close enough to that of the canvas coolers that extensive investigation of various aspects of membrane evaporative cooling appears to be justified, particularly in view of the potential advantages of the latter over the existing evaporative cooling methods. For example, for cool storage of perishable goods in a desert climate, the membrane container might be uniquely qualified because of its low rate of water consumption compared to that of a canvas cooler.

  10. A model for radionuclide transport in the Cooling Water System

    SciTech Connect

    Kahook, S.D.

    1992-08-01

    A radionuclide transport model developed to assess radiological levels in the K-reactor Cooling Water System (CWS) in the event of an inadvertent process water (PW) leakage to the cooling water (CW) in the heat exchangers (HX) is described. During and following a process water leak, the radionuclide transport model determines the time-dependent release rates of radionuclide from the cooling water system to the environment via evaporation to the atmosphere and blow-down to the Savannah River. The developed model allows for delay times associated with the transport of the cooling water radioactivity through cooling water system components. Additionally, this model simulates the time-dependent behavior of radionuclides levels in various CWS components. The developed model is incorporated into the K-reactor Cooling Tower Activity (KCTA) code. KCTA allows the accident (heat exchanger leak rate) and the cooling tower blow-down and evaporation rates to be described as time-dependent functions. Thus, the postulated leak and the consequence of the assumed leak can be modelled realistically. This model is the first of three models to be ultimately assembled to form a comprehensive Liquid Pathway Activity System (LPAS). LPAS will offer integrated formation, transport, deposition, and release estimates for radionuclides formed in a SRS facility. Process water and river water modules are forthcoming as input and downstream components, respectively, for KCTA.

  11. A model for radionuclide transport in the Cooling Water System

    SciTech Connect

    Kahook, S.D.

    1992-08-01

    A radionuclide transport model developed to assess radiological levels in the K-reactor Cooling Water System (CWS) in the event of an inadvertent process water (PW) leakage to the cooling water (CW) in the heat exchangers (HX) is described. During and following a process water leak, the radionuclide transport model determines the time-dependent release rates of radionuclide from the cooling water system to the environment via evaporation to the atmosphere and blow-down to the Savannah River. The developed model allows for delay times associated with the transport of the cooling water radioactivity through cooling water system components. Additionally, this model simulates the time-dependent behavior of radionuclides levels in various CWS components. The developed model is incorporated into the K-reactor Cooling Tower Activity (KCTA) code. KCTA allows the accident (heat exchanger leak rate) and the cooling tower blow-down and evaporation rates to be described as time-dependent functions. Thus, the postulated leak and the consequence of the assumed leak can be modelled realistically. This model is the first of three models to be ultimately assembled to form a comprehensive Liquid Pathway Activity System (LPAS). LPAS will offer integrated formation, transport, deposition, and release estimates for radionuclides formed in a SRS facility. Process water and river water modules are forthcoming as input and downstream components, respectively, for KCTA.

  12. Enhancing water quality modelling & forecasting in the Han River basin (Korea) using data assimilation

    NASA Astrophysics Data System (ADS)

    Loos, Sibren; Sumihar, Julius; Min, Joong-Hyuk; El Serafy, Ghada; Kim, Kyunghyun; Weerts, Albrecht

    2013-04-01

    Data assimilation in operational systems is a promising method to enhance the lead-time and reduce the uncertainty of water quality forecasts and provides a good base for the setup of monitoring schemes in large catchments (locations and frequency of sampling). In the River Han (Korea) three weirs have been constructed to prevent flooding and improve the water quality in the main stream. With real-time automated data imports and two water quality models, HSPF and EFDC, embedded in the FEWS-NIER forecasting platform, information about the current water quality status and daily water quality forecasts seven days ahead is provided to -water management agencies in the basin. To improve both the quality and the lead time of the water quality forecasts the EFDC hydrodynamics and water quality model has been implemented in OpenDA, an open interface standard for data assimilation (DA) in numerical models. The setup of this real-time water quality data assimilation system to enhance the algal dynamics modelling and the forecasts in the Han River basin (20,960 km² in size) was performed by a number of steps using Ensemble Kalman Filtering (EnKF). Using a twin experiment the correct working of the algorithm was tested. Noise was applied to several water quality variables in the main tributaries with a sequential simulation algorithm, to obtain correct noise settings that result in a realistic spread between the individual ensemble members. As the next step, the inclusion of observations in the main stream for data assimilation was tested using the EnKF algorithm to define their effect on the model results. Noise was applied to global solar radiation to improve water temperature forecasts, as well as to phosphate, nitrate and chlorophyll-α concentrations in the large tributaries to improve the prediction of algal level upstream of the weirs. Different combinations of noise and observation settings (standard deviation and time correlation) to find the best model update of

  13. Retrieving moisture profiles from precipitable water measurements using a variational data assimilation approach

    SciTech Connect

    Guo, Y.R.; Zou, X.; Kuo, Y.H.

    1996-04-01

    Atmospheric moisture distribution is directly related to the formation of clouds and precipitation and affects the atmospheric radiation and climate. Currently, several remote sensing systems can measure precipitable water (PW) with fairly high accuracy. As part of the development of an Integrated Data Assimilation and Sounding System in support of the Atmospheric Radiation Measurement Program, retrieving the 3-D water vapor fields from PW measurements is an important problem. A new four dimensional variational (4DVAR) data assimilation system based on the Penn State/National Center for Atmospheric Research (NCAR) mesoscale model (MM5) has been developed by Zou et al. (1995) with the adjoint technique. In this study, we used this 4DVAR system to retrieve the moisture profiles. Because we do not have a set of real observed PW measurements now, the special soundings collected during the Severe Environmental Storm and Mesoscale Experiment (SESAME) in 1979 were used to simulate a set of PW measurements, which were then assimilated into the 4DVAR system. The accuracy of the derived water vapor fields was assessed by direct comparison with the detailed specific humidity soundings. The impact of PW assimilation on precipitation forecast was examined by conducting a series of model forecast experiments started from the different initial conditions with or without data assimilation.

  14. Ammonia production and assimilation: its importance as a tolerance mechanism during moderate water deficit in tomato plants.

    PubMed

    Sánchez-Rodríguez, Eva; Rubio-Wilhelmi, María del Mar; Ríos, Juan José; Blasco, Begoña; Rosales, Miguel Ángel; Melgarejo, Rubén; Romero, Luis; Ruiz, Juan Manuel

    2011-05-15

    Nitrate assimilation diminishes under water stress. This can augment the photorespiratory rate as a protection mechanism, increasing the ammonium concentration, which must be rapidly assimilated. We therefore examined the effect of moderate water stress in photorespiration and N assimilation, as possible tolerance mechanisms in cherry tomato. Five cherry tomato cultivars with different degrees of water stress tolerance were submitted to two water treatments: well-watered (100% FC) and water stress (50% FC). In the susceptible cultivars, nitrate assimilation declined but without stimulating photorespiration. Zarina, a stress-tolerant cultivar, showed increased activity of the main enzymes involved in photorespiration, together with greater assimilation of nitrates and of the resulting ammonium. This translates as higher concentrations of N as well as amino acids and proteins. We characterize these mechanisms in the cv. Zarina (tolerant) as essential to water stress tolerance, acting on N metabolism as well as helping to maintain or augment biomass.

  15. Contaminant assimilation within the water column of two newly created prairie wetlands.

    PubMed

    Polonsky, A P; Clements, W H

    1999-02-01

    This research examined the influence of abiotic factors on contaminant assimilation within the water column of two wetlands (RMA3 and RMA4) located on Rocky Mountain Arsenal National Wildlife Area, north of Denver, Colorado, USA. We define contaminant assimilation as the ability of a wetland system to reduce negative impacts of contaminants on aquatic organisms. To examine the influence of abiotic factors (i.e., alkalinity, suspended solids), chronic toxicity tests were performed from February 1992 through November 1993. Ceriodaphnia dubia were exposed to water from the wetlands, which was spiked with Zn. These tests indicated higher assimilative capacity in wetland RMA4 relative to RMA3. Dissolved organic carbon (DOC) was significantly greater in RMA4 than in RMA3, suggesting that it may have influenced differences in bioavailability of Zn in wetland water. Suspended solids were also consistently higher in RMA4 than in RMA3. To test the influence of suspended solids on contaminant assimilation, C. dubia were exposed to filtered and unfiltered Zn-spiked water from RMA4. The greater toxicity of Zn to C. dubia in filtered water indicated that suspended solids were important in ameliorating impacts of Zn in RMA4. Results from this study suggest that from the suite of variables assessed, DOC and suspended solids were the most important physiochemical influences on Zn toxicity within the water column of these two wetlands. Differences in habitat characteristics of RMA3 and RMA4 demonstrated the importance of site-selection toward functional design of wetlands.

  16. The martian water cycle through assimilation of Thermal Emission Spectrometer data

    NASA Astrophysics Data System (ADS)

    Steele, L.; Lewis, S. R.; Patel, M. R.; Montmessin, F.; Smith, M. D.

    2013-09-01

    We present for the first time an assimilation of Thermal Emission Spectrometer (TES) water vapour column data into a global climate model (GCM) of the martian atmosphere, and discuss the seasonal cycle of water vapour and the processes responsible for the observed vapour distribution. The assimilation scheme is shown to be robust in producing consistent reanalyses even with differing initial conditions, and the global vapour column error is reduced to around 2-4 pr-μm depending on season. Wave activity is shown to play an important role in the vapour distribution, and the assimilated vapour field shows evidence of western boundary currents (WBCs) during aphelion season around Tharsis and Syrtis Major.

  17. Assimilation of Terrestrial Water Storage from GRACE in a Snow-Dominated Basin

    NASA Technical Reports Server (NTRS)

    Forman, Barton A.; Reichle, R. H.; Rodell, M.

    2011-01-01

    Terrestrial water storage (TWS) information derived from Gravity Recovery and Climate Experiment (GRACE) measurements is assimilated into a land surface model over the Mackenzie River basin located in northwest Canada. Assimilation is conducted using an ensemble Kalman smoother (EnKS). Model estimates with and without assimilation are compared against independent observational data sets of snow water equivalent (SWE) and runoff. For SWE, modest improvements in mean difference (MD) and root mean squared difference (RMSD) are achieved as a result of the assimilation. No significant differences in temporal correlations of SWE resulted. Runoff statistics of MD remain relatively unchanged while RMSD statistics, in general, are improved in most of the sub-basins. Temporal correlations are degraded within the most upstream sub-basin, but are, in general, improved at the downstream locations, which are more representative of an integrated basin response. GRACE assimilation using an EnKS offers improvements in hydrologic state/flux estimation, though comparisons with observed runoff would be enhanced by the use of river routing and lake storage routines within the prognostic land surface model. Further, GRACE hydrology products would benefit from the inclusion of better constrained models of post-glacial rebound, which significantly affects GRACE estimates of interannual hydrologic variability in the Mackenzie River basin.

  18. Successful water reuse in open recirculating cooling systems

    SciTech Connect

    Vaska, M.; Lee, B.

    1994-12-31

    Water reuse in open recirculating cooling water systems is becoming increasingly prevalent in industry. Reuse can incorporate a number of varied approaches with the primary goal being water conservation. Market forces driving this trend include scarcity of fresh water makeup sources and higher costs associated with pretreatment of natural waters. Utilization of reuse water for cooling tower makeup has especially detrimental effects on corrosion and deposit rates. Additionally, once the reuse water is cycled and treated with inhibitors, dispersants and microbiocides, acceptability for discharge to a public waterway can be a concern. The task for water treatment suppliers is to guide industry in the feasibility and procedures for successfully achieving these goals. This paper focuses particularly on reuse of municipal wastewater for cooling tower makeup and explores techniques which have been found especially effective. Case histories are described where these concepts have been successfully applied in practice.

  19. Assimilation of AMSR-E snow water equivalent data in a spatially-lumped snow model

    NASA Astrophysics Data System (ADS)

    Dziubanski, David J.; Franz, Kristie J.

    2016-09-01

    Accurately initializing snow model states in hydrologic prediction models is important for estimating future snowmelt, water supplies, and flooding potential. While ground-based snow observations give the most reliable information about snowpack conditions, they are spatially limited. In the north-central USA, there are no continual observations of hydrologically critical snow variables. Satellites offer the most likely source of spatial snow data, such as the snow water equivalent (SWE), for this region. In this study, we test the impact of assimilating SWE data from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) instrument into the US National Weather Service (NWS) SNOW17 model for seven watersheds in the Upper Mississippi River basin. The SNOW17 is coupled with the NWS Sacramento Soil Moisture Accounting (SACSMA) model, and both simulated SWE and discharge are evaluated. The ensemble Kalman filter (EnKF) assimilation framework is applied and updating occurs on a daily cycle for water years 2006-2011. Prior to assimilation, AMSR-E data is bias corrected using data from the National Operational Hydrologic Remote Sensing Center (NOHRSC) airborne snow survey program. An average AMSR-E SWE bias of -17.91 mm was found for the study basins. SNOW17 and SAC-SMA model parameters from the North Central River Forecast Center (NCRFC) are used. Compared to a baseline run without assimilation, the SWE assimilation improved discharge for five of the seven study sites, in particular for high discharge magnitudes associated with snow melt runoff. SWE and discharge simulations suggest that the SNOW17 is underestimating SWE and snowmelt rates in the study basins. Deep snow conditions and periods of snowmelt may have introduced error into the assimilation due to difficulty obtaining accurate brightness temperatures under these conditions. Overall results indicate that the AMSR-E data and EnKF are viable and effective solutions for improving simulations

  20. Establishment and analysis of High-Resolution Assimilation Dataset of water-energy cycle over China

    NASA Astrophysics Data System (ADS)

    Wen, Xiaohang; Liao, Xiaohan; Dong, Wenjie; Yuan, Wenping

    2015-04-01

    For better prediction and understanding of water-energy exchange process and land-atmospheric interaction, the in-situ observed meteorological data which were acquired from China Meteorological Administration (CMA) were assimilated in the Weather Research and Forecasting (WRF) model and the monthly Green Vegetation Coverage (GVF) data, which was calculated by the Normalized Difference Vegetation Index (NDVI) of Earth Observing System Moderate-Resolution Imaging Spectroradiometer (EOS-MODIS), Digital Elevation Model (DEM) data of the Shuttle Radar Topography Mission (SRTM) system were also integrated in the WRF model over China. Further, the High-Resolution Assimilation Dataset of water-energy cycle over China (HRADC) was produced by WRF model. This dataset include 25 km horizontal resolution near surface meteorological data such as air temperature, humidity, ground temperature, and pressure at 19 levels, soil temperature and soil moisture at 4 levels, green vegetation coverage, latent heat flux, sensible heat flux, and ground heat flux for 3 hours. In this study, we 1) briefly introduce the cycling 3D-Var assimilation method; 2) Compare results of meteorological elements such as 2 m temperature, precipitation and ground temperature generated by the HRADC with the gridded observation data from CMA, and Global Land Data Assimilation System (GLDAS) output data from National Aeronautics and Space Administration (NASA). It is found that the results of 2 m temperature were improved compared with the control simulation and has effectively reproduced the observed patterns, and the simulated results of ground temperature, 0-10 cm soil temperature and specific humidity were as much closer to GLDAS outputs. Root mean square errors are reduced in assimilation run than control run, and the assimilation run of ground temperature, 0-10 cm soil temperature, radiation and surface fluxes were agreed well with the GLDAS outputs over China. The HRADC could be used in further research

  1. Application of Data Assimilation with the Root Zone Water Quality Model for Soil Moisture Profile Estimation

    USDA-ARS?s Scientific Manuscript database

    Estimation of soil moisture has received considerable attention in the areas of hydrology, agriculture, meteorology and environmental studies because of its role in the partitioning water and energy at the land surface. In this study, the Ensemble Kalman Filter (EnKF), a popular data assimilation te...

  2. Application of Data Assimilation with the Root Zone Water Quality Model for Soil Moisture Profile Estimation

    USDA-ARS?s Scientific Manuscript database

    The Ensemble Kalman Filter (EnKF), a popular data assimilation technique for non-linear systems was applied to the Root Zone Water Quality Model. Measured soil moisture data at four different depths (5cm, 20cm, 40cm and 60cm) from two agricultural fields (AS1 and AS2) in northeastern Indiana were us...

  3. Section A, view of cooling water pipes and parking garage ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Section A, view of cooling water pipes and parking garage entrance/exit on west slurry wall, looking west. (BH) - World Trade Center Site, Bounded by Vesey, Church, Liberty Streets, & Route 9A, New York County, NY

  4. RED GATE HOUSE, INSTALLATION OF COOLING WATER PENSTOCK FOR NEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    RED GATE HOUSE, INSTALLATION OF COOLING WATER PENSTOCK FOR NEW POWER STATION. PHOTOCOPY OF 1909 VIEW LOOKING NORTHEAST. From the collection of the Manchester Historic Association, Manchester, N. H. - Amoskeag Millyard, Canal Street, Manchester, Hillsborough County, NH

  5. 38. DETAIL OF COOLING WATER BOOSTER PUMP FOR OXYGEN FURNACES, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. DETAIL OF COOLING WATER BOOSTER PUMP FOR OXYGEN FURNACES, LANCES, AND FUME HOODS IN THE GAS WASHER PUMP HOUSE LOOKING EAST. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  6. 68. DETAIL OF COOLING WATER PIPES FOR DOROTHY SIX BLAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. DETAIL OF COOLING WATER PIPES FOR DOROTHY SIX BLAST FURNACE. INTERIOR OF CAST HOUSE LOOKING NORTH. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  7. Carbon Assimilation Pathways, Water Relationships and Plant Ecology.

    ERIC Educational Resources Information Center

    Etherington, John R.

    1988-01-01

    Discusses between-species variation in adaptation of the photosynthetic mechanism to cope with wide fluctuations of environmental water regime. Describes models for water conservation in plants and the role of photorespiration in the evolution of the different pathways. (CW)

  8. Carbon Assimilation Pathways, Water Relationships and Plant Ecology.

    ERIC Educational Resources Information Center

    Etherington, John R.

    1988-01-01

    Discusses between-species variation in adaptation of the photosynthetic mechanism to cope with wide fluctuations of environmental water regime. Describes models for water conservation in plants and the role of photorespiration in the evolution of the different pathways. (CW)

  9. Assimilation of gridded terrestrial water storage observations from GRACE into a land surface model

    NASA Astrophysics Data System (ADS)

    Girotto, Manuela; De Lannoy, Gabriëlle J. M.; Reichle, Rolf H.; Rodell, Matthew

    2016-05-01

    Observations of terrestrial water storage (TWS) from the Gravity Recovery and Climate Experiment (GRACE) satellite mission have a coarse resolution in time (monthly) and space (roughly 150,000 km2 at midlatitudes) and vertically integrate all water storage components over land, including soil moisture and groundwater. Data assimilation can be used to horizontally downscale and vertically partition GRACE-TWS observations. This work proposes a variant of existing ensemble-based GRACE-TWS data assimilation schemes. The new algorithm differs in how the analysis increments are computed and applied. Existing schemes correlate the uncertainty in the modeled monthly TWS estimates with errors in the soil moisture profile state variables at a single instant in the month and then apply the increment either at the end of the month or gradually throughout the month. The proposed new scheme first computes increments for each day of the month and then applies the average of those increments at the beginning of the month. The new scheme therefore better reflects submonthly variations in TWS errors. The new and existing schemes are investigated here using gridded GRACE-TWS observations. The assimilation results are validated at the monthly time scale, using in situ measurements of groundwater depth and soil moisture across the U.S. The new assimilation scheme yields improved (although not in a statistically significant sense) skill metrics for groundwater compared to the open-loop (no assimilation) simulations and compared to the existing assimilation schemes. A smaller impact is seen for surface and root-zone soil moisture, which have a shorter memory and receive smaller increments from TWS assimilation than groundwater. These results motivate future efforts to combine GRACE-TWS observations with observations that are more sensitive to surface soil moisture, such as L-band brightness temperature observations from Soil Moisture Ocean Salinity (SMOS) or Soil Moisture Active Passive

  10. Assimilation of Gridded Terrestrial Water Storage Observations from GRACE into a Land Surface Model

    NASA Technical Reports Server (NTRS)

    Girotto, Manuela; De Lannoy, Gabrielle J. M.; Reichle, Rolf H.; Rodell, Matthew

    2016-01-01

    Observations of terrestrial water storage (TWS) from the Gravity Recovery and Climate Experiment (GRACE) satellite mission have a coarse resolution in time (monthly) and space (roughly 150,000 km(sup 2) at midlatitudes) and vertically integrate all water storage components over land, including soil moisture and groundwater. Data assimilation can be used to horizontally downscale and vertically partition GRACE-TWS observations. This work proposes a variant of existing ensemble-based GRACE-TWS data assimilation schemes. The new algorithm differs in how the analysis increments are computed and applied. Existing schemes correlate the uncertainty in the modeled monthly TWS estimates with errors in the soil moisture profile state variables at a single instant in the month and then apply the increment either at the end of the month or gradually throughout the month. The proposed new scheme first computes increments for each day of the month and then applies the average of those increments at the beginning of the month. The new scheme therefore better reflects submonthly variations in TWS errors. The new and existing schemes are investigated here using gridded GRACE-TWS observations. The assimilation results are validated at the monthly time scale, using in situ measurements of groundwater depth and soil moisture across the U.S. The new assimilation scheme yields improved (although not in a statistically significant sense) skill metrics for groundwater compared to the open-loop (no assimilation) simulations and compared to the existing assimilation schemes. A smaller impact is seen for surface and root-zone soil moisture, which have a shorter memory and receive smaller increments from TWS assimilation than groundwater. These results motivate future efforts to combine GRACE-TWS observations with observations that are more sensitive to surface soil moisture, such as L-band brightness temperature observations from Soil Moisture Ocean Salinity (SMOS) or Soil Moisture Active

  11. Assimilation of Gridded Terrestrial Water Storage Observations from GRACE into a Land Surface Model

    NASA Technical Reports Server (NTRS)

    Girotto, Manuela; De Lannoy, Gabrielle J. M.; Reichle, Rolf H.; Rodell, Matthew

    2016-01-01

    Observations of terrestrial water storage (TWS) from the Gravity Recovery and Climate Experiment (GRACE) satellite mission have a coarse resolution in time (monthly) and space (roughly 150,000 km(sup 2) at midlatitudes) and vertically integrate all water storage components over land, including soil moisture and groundwater. Data assimilation can be used to horizontally downscale and vertically partition GRACE-TWS observations. This work proposes a variant of existing ensemble-based GRACE-TWS data assimilation schemes. The new algorithm differs in how the analysis increments are computed and applied. Existing schemes correlate the uncertainty in the modeled monthly TWS estimates with errors in the soil moisture profile state variables at a single instant in the month and then apply the increment either at the end of the month or gradually throughout the month. The proposed new scheme first computes increments for each day of the month and then applies the average of those increments at the beginning of the month. The new scheme therefore better reflects submonthly variations in TWS errors. The new and existing schemes are investigated here using gridded GRACE-TWS observations. The assimilation results are validated at the monthly time scale, using in situ measurements of groundwater depth and soil moisture across the U.S. The new assimilation scheme yields improved (although not in a statistically significant sense) skill metrics for groundwater compared to the open-loop (no assimilation) simulations and compared to the existing assimilation schemes. A smaller impact is seen for surface and root-zone soil moisture, which have a shorter memory and receive smaller increments from TWS assimilation than groundwater. These results motivate future efforts to combine GRACE-TWS observations with observations that are more sensitive to surface soil moisture, such as L-band brightness temperature observations from Soil Moisture Ocean Salinity (SMOS) or Soil Moisture Active

  12. Setup assessment for assimilating GRACE observations into the Australian Water Resource Assessment (AWRA) model

    NASA Astrophysics Data System (ADS)

    Khaki, Mehdi; Hoteit, Ibrahim; Schumacher, Maike; Van Dijk, Albert; Kuhn, Michael; Awange, Joseph; Forootan, Ehsan

    2016-04-01

    Hydrological models have usually been used to simulate variations in water storage compartments resulting from changes in fluxes (i.e., precipitation, evapotranspiration) considering physical or conceptual frameworks. In an effort to improve the simulation of storage compartments, this research investigated the benefits of assimilating the Gravity Recovery and Climate Experiment (GRACE) derived terrestrial water storage (TWS) anomalies into the AWRA (Australian Water Resource Assessment) model using an ensemble Kalman filter (EnKF) approach in 2009. The Murray-Darling Basin (MDB), which is Australia's biggest river system, was selected to perform the assimilation. Our investigations address (i) the optimal implementation of the EnKF, including sensitivity to ensemble size, localization length scale, observational errors correlations, inflation and stochastic parameterization of forcing terms, and (ii) the best strategy for assimilating GRACE data, which are available at different spatial resolutions (few hundred kilometres). Our motivation to select EnKF was due to its promising performance in previous studies to deal with the nonlinearity and high-dimensionality of hydrological models. However, the small size of ensembles might represent a critical issue for its success, since the statistical state of the system might not be well represented. Therefore, in this study, we analysed the relation between ensemble size and the performance of assimilation process. Previous studies have demonstrated that GRACE can be used to enhance the performance of models. However, it is very difficult to deal with its relatively low spatial resolution. Furthermore, assimilation of GRACE TWS measurements at different spatial resolution may result in different degree of improvements. Therefore, attempts were made here to find an optimal assimilation resolution of GRACE TWS observations into AWRA over MDB. Eventually, a localization approach was applied to modify the error covariance

  13. Cooling of gas turbines IX : cooling effects from use of ceramic coatings on water-cooled turbine blades

    NASA Technical Reports Server (NTRS)

    Brown, W Byron; Livingood, John N B

    1948-01-01

    The hottest part of a turbine blade is likely to be the trailing portion. When the blades are cooled and when water is used as the coolant, the cooling passages are placed as close as possible to the trailing edge in order to cool this portion. In some cases, however, the trailing portion of the blade is so narrow, for aerodynamic reasons, that water passages cannot be located very near the trailing edge. Because ceramic coatings offer the possibility of protection for the trailing part of such narrow blades, a theoretical study has been made of the cooling effect of a ceramic coating on: (1) the blade-metal temperature when the gas temperature is unchanged, and (2) the gas temperature when the metal temperature is unchanged. Comparison is also made between the changes in the blade or gas temperatures produced by ceramic coatings and the changes produced by moving the cooling passages nearer the trailing edge. This comparison was made to provide a standard for evaluating the gains obtainable with ceramic coatings as compared to those obtainable by constructing the turbine blade in such a manner that water passages could be located very near the trailing edge.

  14. PBF Cooling Tower under construction. Cold water basin is five ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower under construction. Cold water basin is five feet deep. Foundation and basin walls are reinforced concrete. Camera facing west. Pipe openings through wall in front are outlets for return flow of cool water to reactor building. Photographer: John Capek. Date: September 4, 1968. INEEL negative no. 68-3473 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  15. Prototype solar heating and cooling systems, including potable hot water

    NASA Technical Reports Server (NTRS)

    Bloomquist, D.; Oonk, R. L.

    1977-01-01

    Progress made in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water is reported. The system consists of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition. A comparison of the proposed Solaron Heat Pump and Solar Desiccant Heating and Cooling Systems, installation drawings, data on the Akron House at Akron, Ohio, and other program activities are included.

  16. DUSEL Facility Cooling Water Scaling Issues

    SciTech Connect

    Daily, W D

    2011-04-05

    Precipitation (crystal growth) in supersaturated solutions is governed by both kenetic and thermodynamic processes. This is an important and evolving field of research, especially for the petroleum industry. There are several types of precipitates including sulfate compounds (ie. barium sulfate) and calcium compounds (ie. calcium carbonate). The chemical makeup of the mine water has relatively large concentrations of sulfate as compared to calcium, so we may expect that sulfate type reactions. The kinetics of calcium sulfate dihydrate (CaSO4 {center_dot} 2H20, gypsum) scale formation on heat exchanger surfaces from aqueous solutions has been studied by a highly reproducible technique. It has been found that gypsum scale formation takes place directly on the surface of the heat exchanger without any bulk or spontaneous precipitation in the reaction cell. The kinetic data also indicate that the rate of scale formation is a function of surface area and the metallurgy of the heat exchanger. As we don't have detailed information about the heat exchanger, we can only infer that this will be an issue for us. Supersaturations of various compounds are affected differently by temperature, pressure and pH. Pressure has only a slight affect on the solubility, whereas temperature is a much more sensitive parameter (Figure 1). The affect of temperature is reversed for calcium carbonate and barium sulfate solubilities. As temperature increases, barium sulfate solubility concentrations increase and scaling decreases. For calcium carbonate, the scaling tendencies increase with increasing temperature. This is all relative, as the temperatures and pressures of the referenced experiments range from 122 to 356 F. Their pressures range from 200 to 4000 psi. Because the cooling water system isn't likely to see pressures above 200 psi, it's unclear if this pressure/scaling relationship will be significant or even apparent. The most common scale minerals found in the oilfield include

  17. [Simulation of water and carbon fluxes in harvard forest area based on data assimilation method].

    PubMed

    Zhang, Ting-Long; Sun, Rui; Zhang, Rong-Hua; Zhang, Lei

    2013-10-01

    Model simulation and in situ observation are the two most important means in studying the water and carbon cycles of terrestrial ecosystems, but have their own advantages and shortcomings. To combine these two means would help to reflect the dynamic changes of ecosystem water and carbon fluxes more accurately. Data assimilation provides an effective way to integrate the model simulation and in situ observation. Based on the observation data from the Harvard Forest Environmental Monitoring Site (EMS), and by using ensemble Kalman Filter algorithm, this paper assimilated the field measured LAI and remote sensing LAI into the Biome-BGC model to simulate the water and carbon fluxes in Harvard forest area. As compared with the original model simulated without data assimilation, the improved Biome-BGC model with the assimilation of the field measured LAI in 1998, 1999, and 2006 increased the coefficient of determination R2 between model simulation and flux observation for the net ecosystem exchange (NEE) and evapotranspiration by 8.4% and 10.6%, decreased the sum of absolute error (SAE) and root mean square error (RMSE) of NEE by 17.7% and 21.2%, and decreased the SAE and RMSE of the evapotranspiration by 26. 8% and 28.3%, respectively. After assimilated the MODIS LAI products of 2000-2004 into the improved Biome-BGC model, the R2 between simulated and observed results of NEE and evapotranspiration was increased by 7.8% and 4.7%, the SAE and RMSE of NEE were decreased by 21.9% and 26.3%, and the SAE and RMSE of evapotranspiration were decreased by 24.5% and 25.5%, respectively. It was suggested that the simulation accuracy of ecosystem water and carbon fluxes could be effectively improved if the field measured LAI or remote sensing LAI was integrated into the model.

  18. Efficient assimilation of cyanobacterial nitrogen by water hyacinth.

    PubMed

    Qin, Hongjie; Zhang, Zhiyong; Liu, Minhui; Wang, Yan; Wen, Xuezheng; Yan, Shaohua; Zhang, Yingying; Liu, Haiqin

    2017-10-01

    A (15)N labeling technique was used to study nitrogen transfer from cyanobacterium Microcystis aeruginosa to water hyacinth. (15)N atom abundance in M. aeruginosa peaked (15.52%) after cultivation in (15)N-labeled medium for 3weeks. Over 87% of algal nitrogen was transferred into water hyacinth after the 4-week co-cultivation period. The nitrogen quickly super-accumulated in the water hyacinth roots, and the labeled nitrogen was re-distributed to different organs (i.e., roots, stalks, and leaves). This study provides a new strategy for further research on cyanobacterial bloom control, nitrogen migration, and nitrogen cycle in eutrophic waters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Lognormal Assimilation of Water Vapor in a WRF-GSI Cycled System

    NASA Astrophysics Data System (ADS)

    Fletcher, S. J.; Kliewer, A.; Jones, A. S.; Forsythe, J. M.

    2015-12-01

    Recent publications have shown the viability of both detecting a lognormally-distributed signal for water vapor mixing ratio and the improved quality of satellite retrievals in a 1DVAR mixed lognormal-Gaussian assimilation scheme over a Gaussian-only system. This mixed scheme is incorporated into the Gridpoint Statistical Interpolation (GSI) assimilation scheme with the goal of improving forecasts from the Weather Research and Forecasting (WRF) Model in a cycled system. Results are presented of the impact of treating water vapor as a lognormal random variable. Included in the analysis are: 1) the evolution of Tropical Storm Chris from 2006, and 2) an analysis of a "Pineapple Express" water vapor event from 2005 where a lognormal signal has been previously detected.

  20. The seasonal cycle of water vapour on Mars from assimilation of Thermal Emission Spectrometer data

    NASA Astrophysics Data System (ADS)

    Steele, Liam J.; Lewis, Stephen R.; Patel, Manish R.; Montmessin, Franck; Forget, François; Smith, Michael D.

    2014-07-01

    We present for the first time an assimilation of Thermal Emission Spectrometer (TES) water vapour column data into a Mars global climate model (MGCM). We discuss the seasonal cycle of water vapour, the processes responsible for the observed water vapour distribution, and the cross-hemispheric water transport. The assimilation scheme is shown to be robust in producing consistent reanalyses, and the global water vapour column error is reduced to around 2-4 pr μm depending on season. Wave activity is shown to play an important role in the water vapour distribution, with topographically steered flows around the Hellas and Argyre basins acting to increase transport in these regions in all seasons. At high northern latitudes, zonal wavenumber 1 and 2 stationary waves during northern summer are responsible for spreading the sublimed water vapour away from the pole. Transport by the zonal wavenumber 2 waves occurs primarily to the west of Tharsis and Arabia Terra and, combined with the effects of western boundary currents, this leads to peak water vapour column abundances here as observed by numerous spacecraft. A net transport of water to the northern hemisphere over the course of one Mars year is calculated, primarily because of the large northwards flux of water vapour which occurs during the local dust storm around LS=240-260°. Finally, outlying frost deposits that surround the north polar cap are shown to be important in creating the peak water vapour column abundances observed during northern summer.

  1. The Seasonal Cycle of Water Vapour on Mars from Assimilation of Thermal Emission Spectrometer Data

    NASA Technical Reports Server (NTRS)

    Steele, Liam J.; Lewis, Stephen R.; Patel, Manish R.; Montmessin, Franck; Forget, Francois; Smith, Michael D.

    2014-01-01

    We present for the first time an assimilation of Thermal Emission Spectrometer (TES) water vapour column data into a Mars global climate model (MGCM). We discuss the seasonal cycle of water vapour, the processes responsible for the observed water vapour distribution, and the cross-hemispheric water transport. The assimilation scheme is shown to be robust in producing consistent reanalyses, and the global water vapour column error is reduced to around 2-4 pr micron depending on season. Wave activity is shown to play an important role in the water vapour distribution, with topographically steered flows around the Hellas and Argyre basins acting to increase transport in these regions in all seasons. At high northern latitudes, zonal wavenumber 1 and 2 stationary waves during northern summer are responsible for spreading the sublimed water vapour away from the pole. Transport by the zonal wavenumber 2 waves occurs primarily to the west of Tharsis and Arabia Terra and, combined with the effects of western boundary currents, this leads to peak water vapour column abundances here as observed by numerous spacecraft. A net transport of water to the northern hemisphere over the course of one Mars year is calculated, primarily because of the large northwards flux of water vapour which occurs during the local dust storm around L(sub S) = 240-260deg. Finally, outlying frost deposits that surround the north polar cap are shown to be important in creating the peak water vapour column abundances observed during northern summer.

  2. Use of reclaimed water for power plant cooling.

    SciTech Connect

    Veil, J. A.; Environmental Science Division

    2007-10-16

    Freshwater demands are steadily increasing throughout the United States. As its population increases, more water is needed for domestic use (drinking, cooking, cleaning, etc.) and to supply power and food. In arid parts of the country, existing freshwater supplies are not able to meet the increasing demands for water. New water users are often forced to look to alternative sources of water to meet their needs. Over the past few years, utilities in many locations, including parts of the country not traditionally water-poor (e.g., Georgia, Maryland, Massachusetts, New York, and North Carolina) have needed to reevaluate the availability of water to meet their cooling needs. This trend will only become more extreme with time. Other trends are likely to increase pressure on freshwater supplies, too. For example, as populations increase, they will require more food. This in turn will likely increase demands for water by the agricultural sector. Another example is the recent increased interest in producing biofuels. Additional water will be required to grow more crops to serve as the raw materials for biofuels and to process the raw materials into biofuels. This report provides information about an opportunity to reuse an abundant water source -- treated municipal wastewater, also known as 'reclaimed water' -- for cooling and process water in electric generating facilities. The report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Innovations for Existing Plants research program (Feeley 2005). This program initiated an energy-water research effort in 2003 that includes the availability and use of 'nontraditional sources' of water for use at power plants. This report represents a unique reference for information on the use of reclaimed water for power plant cooling. In particular, the database of reclaimed water user facilities described in Chapter 2 is the first comprehensive national effort to identify and catalog those

  3. Water Uptake and Carbon Assimilation in Maize at Elevated and ambient CO2: Modeling and Measurement.

    NASA Astrophysics Data System (ADS)

    Timlin, Dennis; Chun, Jong-Ahn; Kim, Soo-Hyung; Yang, Yang; Fleisher, David; Reddy, Vangimalla

    2013-04-01

    Potential transpiration in crops is dependent on both plant and environmental properties. Carbon dioxide content of the atmosphere is linked to potential transpiration because CO2 diffuses onto water saturated surfaces within plant stomata. At high CO2 concentrations, CO2 diffuses rapidly into stomata and therefore stomata do not have to remain open to the atmosphere for long periods of time. This results in lower transpiration rates per unit CO2 assimilated at elevated CO2 concentrations. The objective of this study was to measure CO2 assimilation and water uptake by maize under different irrigation regimes and two CO2 concentrations. The data were then used to evaluate the ability of the maize model MaizSim to simulate the effects of water stress and CO2 on water use and photosynthesis. MaizSim uses a Farquhar type photosynthesis model coupled a Ball-Berry stomatal control model. Non-linear beta functions are used to estimate the effects of temperature on growth and development processes. The experimental data come from experiments in outdoor, sunlit growth chambers at the USDA-ARS Beltsville Agricultural Research Center. The eight treatments comprised two levels of carbon dioxide concentrations (400 and 800 ppm) and four levels of water stress (well-watered control, mild, moderate, and severe). The water stress treatments were applied at both CO2 levels. Water contents were monitored hourly by a Time Domain Reflectometry (TDR) system. The model simulated higher water contents at the same time after applying water stress at the high CO2 treatment than for the low CO2 treatment as was found in the measured data. Measurement of water uptake by roots and carbon assimilation rates in the chambers will be addressed.

  4. Microchannel water cooling of silicon x-ray monochromator crystals

    SciTech Connect

    Arthur, J.; Tompkins, W.H.; Troxel, C. Jr. ); Contolini, R.J.; Schmitt, E. ); Bilderback, D.H.; Henderson, C.; White, J.; Settersten, T. )

    1992-01-01

    The use in silicon x-ray monochromator crystals of water cooling channels with dimensions optimized for efficient heat transfer from silicon to water has been investigated. Such channels are typically about 40 {mu}m wide and 400 {mu}m deep. Procedures have been found for reliably producing microchannel-cooled crystals with very small amounts of residual strain. These crystals have been tested at a high-power wiggler beam line at the Cornell High Energy Synchrotron Source, using an x-ray beam having total power in excess of 250 W and normal-incidence power density greater than 5 W/mm{sup 2}. Under these conditions, the surface-temperature rise of a typical microchannel-cooled crystal was less than 5 {degree}C, and degradation of the (111) rocking curve at 12 keV was very slight. The cooling efficiency is consistent with analytic calculations.

  5. Water-cooled insulated steam-injection wells

    NASA Technical Reports Server (NTRS)

    Back, L. H.; Jaffe, L. D.

    1980-01-01

    Water is used as insulated coolant and heat-transfer medium for steam-injection oil wells. Approach is somewhat analogous to cooling system in liquid-propellant rocket. In addition to trapping and delivering heat to steam-injection point, water will also keep casing cooler, preventing or reducing casing failures caused by thermal stresses.

  6. Water-cooled insulated steam-injection wells

    NASA Technical Reports Server (NTRS)

    Back, L. H.; Jaffe, L. D.

    1980-01-01

    Water is used as insulated coolant and heat-transfer medium for steam-injection oil wells. Approach is somewhat analogous to cooling system in liquid-propellant rocket. In addition to trapping and delivering heat to steam-injection point, water will also keep casing cooler, preventing or reducing casing failures caused by thermal stresses.

  7. Prototype solar heating and cooling systems including potable hot water

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Progress is reviewed in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water. The system consisted of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition.

  8. Prototype solar heating and cooling systems including potable hot water

    NASA Technical Reports Server (NTRS)

    1978-01-01

    These combined quarterly reports summarize the activities from November 1977 through September 1978, and over the progress made in the development, delivery and support of two prototype solar heating and cooling systems including potable hot water. The system consists of the following subsystems: solar collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition.

  9. A data acquisition system for water heating and cooling experiments

    NASA Astrophysics Data System (ADS)

    Perea Martins, J. E. M.

    2017-01-01

    This work presents a simple analogue waterproof temperature probe design and its electronic interfacing with a computer to compose a data acquisition system for water temperature measurement. It also demonstrates the system usage through an experiment to verify the water heating period with an electric heater and another to verify the Newton’s law of cooling

  10. [Immediate cooling with water: emergency treatment of burns].

    PubMed

    Latarjet, J

    1990-01-01

    Experimental data have demonstrated that prolonged immediate cooling with cold water is the best first-aid treatment for burn injuries. However in France, this treatment is rarely applied; instead old, inefficient and aggravating methods are still very popular. Pediatricians must help to change this practice by recommending immediate cold water treatment for burns in children.

  11. Short-range precipitation forecasts using assimilation of simulated satellite water vapor profiles and column cloud liquid water amounts

    NASA Technical Reports Server (NTRS)

    Wu, Xiaohua; Diak, George R.; Hayden, Cristopher M.; Young, John A.

    1995-01-01

    These observing system simulation experiments investigate the assimilation of satellite-observed water vapor and cloud liquid water data in the initialization of a limited-area primitive equations model with the goal of improving short-range precipitation forecasts. The assimilation procedure presented includes two aspects: specification of an initial cloud liquid water vertical distribution and diabatic initialization. The satellite data is simulated for the next generation of polar-orbiting satellite instruments, the Advanced Microwave Sounding Unit (AMSU) and the High-Resolution Infrared Sounder (HIRS), which are scheduled to be launched on the NOAA-K satellite in the mid-1990s. Based on cloud-top height and total column cloud liquid water amounts simulated for satellite data a diagnostic method is used to specify an initial cloud water vertical distribution and to modify the initial moisture distribution in cloudy areas. Using a diabatic initialization procedure, the associated latent heating profiles are directly assimilated into the numerical model. The initial heating is estimated by time averaging the latent heat release from convective and large-scale condensation during the early forecast stage after insertion of satellite-observed temperature, water vapor, and cloud water formation. The assimilation of satellite-observed moisture and cloud water, together withy three-mode diabatic initialization, significantly alleviates the model precipitation spinup problem, especially in the first 3 h of the forecast. Experimental forecasts indicate that the impact of satellite-observed temperature and water vapor profiles and cloud water alone in the initialization procedure shortens the spinup time for precipitation rates by 1-2 h and for regeneration of the areal coverage by 3 h. The diabatic initialization further reduces the precipitation spinup time (compared to adiabatic initialization) by 1 h.

  12. Acclimation of CO2 Assimilation in Cotton Leaves to Water Stress and Salinity 1

    PubMed Central

    Plaut, Zvi; Federman, Evelyn

    1991-01-01

    Cotton (Gossypium hirsutum L. cv Acala SJ2) plants were exposed to three levels of osmotic or matric potentials. The first was obtained by salt and the latter by withholding irrigation water. Plants were acclimated to the two stress types by reducing the rate of stress development by a factor of 4 to 7. CO2 assimilation was then determined on acclimated and nonacclimated plants. The decrease of CO2 assimilation in salinity-exposed plants was significantly less in acclimated as compared with nonacclimated plants. Such a difference was not found under water stress at ambient CO2 partial pressure. The slopes of net CO2 assimilation versus intercellular CO2 partial pressure, for the initial linear portion of this relationship, were increased in plants acclimated to salinity of −0.3 and −0.6 megapascal but not in nonacclimated plants. In plants acclimated to water stress, this change in slopes was not significant. Leaf osmotic potential was reduced much more in acclimated than in nonacclimated plants, resulting in turgor maintenance even at −0.9 megapascal. In nonacclimated plants, turgor pressure reached zero at approximately −0.5 megapascal. The accumulation of Cl− and Na+ in the salinity-acclimated plants fully accounted for the decrease in leaf osmotic potential. The rise in concentration of organic solutes comprised only 5% of the total increase in solutes in salinity-acclimated and 10 to 20% in water-stress-acclimated plants. This acclimation was interpreted in light of the higher protein content per unit leaf area and the enhanced ribulose bisphosphate carboxylase activity. At saturating CO2 partial pressure, the declined inhibition in CO2 assimilation of stress-acclimated plants was found for both salinity and water stress. ImagesFigure 2 PMID:16668429

  13. On the assimilation of SWOT type data into 2D shallow-water models

    NASA Astrophysics Data System (ADS)

    Frédéric, Couderc; Denis, Dartus; Pierre-André, Garambois; Ronan, Madec; Jérôme, Monnier; Jean-Paul, Villa

    2013-04-01

    In river hydraulics, assimilation of water level measurements at gauging stations is well controlled, while assimilation of images is still delicate. In the present talk, we address the richness of satellite mapped information to constrain a 2D shallow-water model, but also related difficulties. 2D shallow models may be necessary for small scale modelling in particular for low-water and flood plain flows. Since in both cases, the dynamics of the wet-dry front is essential, one has to elaborate robust and accurate solvers. In this contribution we introduce robust second order, stable finite volume scheme [CoMaMoViDaLa]. Comparisons of real like tests cases with more classical solvers highlight the importance of an accurate flood plain modelling. A preliminary inverse study is presented in a flood plain flow case, [LaMo] [HoLaMoPu]. As a first step, a 0th order data processing model improves observation operator and produces more reliable water level derived from rough measurements [PuRa]. Then, both model and flow behaviours can be better understood thanks to variational sensitivities based on a gradient computation and adjoint equations. It can reveal several difficulties that a model designer has to tackle. Next, a 4D-Var data assimilation algorithm used with spatialized data leads to improved model calibration and potentially leads to identify river discharges. All the algorithms are implemented into DassFlow software (Fortran, MPI, adjoint) [Da]. All these results and experiments (accurate wet-dry front dynamics, sensitivities analysis, identification of discharges and calibration of model) are currently performed in view to use data from the future SWOT mission. [CoMaMoViDaLa] F. Couderc, R. Madec, J. Monnier, J.-P. Vila, D. Dartus, K. Larnier. "Sensitivity analysis and variational data assimilation for geophysical shallow water flows". Submitted. [Da] DassFlow - Data Assimilation for Free Surface Flows. Computational software http

  14. Mathematical model and calculation of water-cooling efficiency in a film-filled cooling tower

    NASA Astrophysics Data System (ADS)

    Laptev, A. G.; Lapteva, E. A.

    2016-10-01

    Different approaches to simulation of momentum, mass, and energy transfer in packed beds are considered. The mathematical model of heat and mass transfer in a wetted packed bed for turbulent gas flow and laminar wave counter flow of the fluid film in sprinkler units of a water-cooling tower is presented. The packed bed is represented as the set of equivalent channels with correction to twisting. The idea put forward by P. Kapitsa on representation of waves on the interphase film surface as elements of the surface roughness in interaction with the gas flow is used. The temperature and moisture content profiles are found from the solution of differential equations of heat and mass transfer written for the equivalent channel with the volume heat and mass source. The equations for calculation of the average coefficients of heat emission and mass exchange in regular and irregular beds with different contact elements, as well as the expression for calculation of the average turbulent exchange coefficient are presented. The given formulas determine these coefficients for the known hydraulic resistance of the packed bed element. The results of solution of the system of equations are presented, and the water temperature profiles are shown for different sprinkler units in industrial water-cooling towers. The comparison with experimental data on thermal efficiency of the cooling tower is made; this allows one to determine the temperature of the cooled water at the output. The technical solutions on increasing the cooling tower performance by equalization of the air velocity profile at the input and creation of an additional phase contact region using irregular elements "Inzhekhim" are considered.

  15. Factors stimulating propagation of legionellae in cooling tower water

    SciTech Connect

    Yamamoto, Hiroyuki; Sugiura, Minoru; Kusunoki, Shinji; Ezaki, Takayuki; Ikedo, Masanari; Yabuuchi, Eiko )

    1992-04-01

    The authors survey of cooling tower water demonstrated that the highest density of legionellae, {ge}10{sup 4} CFU/100 ml, appeared in water containing protozoa, {ge}10{sup 2} MPN/100 ml, and heterotrophic bacteria, {ge}10{sup 6} CFU/100 ml, at water temperatures between 25 and 35C. Viable counts of legionellae were detected even in the winter samples, and propagation, up to 10{sup 5} CFU/100 ml, occurs in summer. The counts of legionellae correlated positively with increases in water temperature, pH, and protozoan counts, but not with heterotrophic bacterial counts. The water temperature of cooling towers may promote increases in the viable counts of legionellae, and certain microbes, e.g., protozoa or some heterotrophic bacteria, may be a factor stimulating the propagation of legionellae.

  16. Cool-Water Carbonates, SEPM Special Publication No. 56

    NASA Astrophysics Data System (ADS)

    Hallock, Pamela

    Doesn't field work on modern carbonates mean scuba diving on spectacular coral reefs in gin-clear water teeming with brightly colored fish? Not if you are one of the researchers that Jonathan Clarke of the Western Mining Corporation Ltd., in Preston, Victoria, Australia, assembled at a workshop in Geelong, Victoria, in January 1995. Their field work involves research cruises in high-latitude oceans, where mal de mer and chilling winds are constant companions. Many braved 10-m seas in modest-sized research vessels to sample shelves stripped of fine sediments by storm waves whose effects can reach to depths exceeding 200 m. Noel James of Queen's University in Kingston, Ontario, carefully lays the groundwork for the book in a paper titled, “The Cool-Water Carbonate Depositional Realm,” which will assuredly become a standard reading assignment in advanced undergraduate-and graduate-level courses in carbonate sedimentology. James skillfully shows how cool-water carbonates are part of the greater carbonate depositional spectrum. By expanding recognition of the possible range of carbonate environments, sedimentologists expand their ability to understand and interpret ancient carbonates, particularly Paleozoic limestones that often show striking similarities to modern cool-water sediments. James' paper is followed by nine papers on modern cool-water carbonates, seven on Tertiary environments, and seven examples from Mesozoic and Paleozoic limestones

  17. Computer modeling of lime-soda softening of cooling waters

    SciTech Connect

    Chen, J.C.Y.

    1986-01-01

    A computer model is developed to fully describe the lime soda ash softening process. This process has a long history of being used to remove calcium and magnesium hardness from cooling waters in order to prevent scaling on heat exchangers. Softening of makeup water and/or a sidestream from the recirculating water will allow a reduction in blowdown. In the extreme case, zero blowdown may be accomplished to conserve cooling waters and to save the costs of disposing of blowdown. Cooling waters differ from most natural waters in having higher temperature and higher concentration of dissolved solids, and, therefore, a higher ionic strength. These factors plus the effects of complex formation are taken into consideration in the development of the computer model. To determine the composition of a softened water, the model assumes that an equilibrium state is reached in a reactor, and employs the equations of mass action and mass balance. The resulting nonlinear simultaneous equations are then linearized by Taylor series expansion and solved by the multidimensional Newton-Raphson method. The computer predictions are compared to the results of laboratory studies using synthetic waters.

  18. Condensate polishers for brackish water-cooled PWRs

    SciTech Connect

    Sadler, M.A.; Darvill, M.R.; Bickerstaffe, J.A.; Chakravorti, R.; Siegwarth, D.P.

    1986-07-01

    The objectives of project RP 1571-5 ''Optimization of Pressurized Water Reactor Secondary Water Treatment: Task 4 Conceptual Design Options - Condensate Polishing'' were to provide detailed guidelines for the design of a condensate polishing system for retrofitting to a seawater cooled PWR. For this purpose a national 1100MW PWR with recirculating steam generators was defined. The polished water to be produced by this plant must be of such a quality so as to permit the advisory SGOG guidelines on impurity levels in Steam Generator water to be achieved. Target maximum impurity levels in the final polished water were proposed by the RP 1571 Project review Team and adopted for this study.

  19. Benefits and pitfalls of GRACE data assimilation: A case study of terrestrial water storage depletion in India

    NASA Astrophysics Data System (ADS)

    Girotto, Manuela; De Lannoy, Gabriëlle J. M.; Reichle, Rolf H.; Rodell, Matthew; Draper, Clara; Bhanja, Soumendra N.; Mukherjee, Abhijit

    2017-05-01

    This study investigates some of the benefits and drawbacks of assimilating terrestrial water storage (TWS) observations from the Gravity Recovery and Climate Experiment (GRACE) into a land surface model over India. GRACE observes TWS depletion associated with anthropogenic groundwater extraction in northwest India. The model, however, does not represent anthropogenic groundwater withdrawals and is not skillful in reproducing the interannual variability of groundwater. Assimilation of GRACE TWS introduces long-term trends and improves the interannual variability in groundwater. But the assimilation also introduces a negative trend in simulated evapotranspiration, whereas in reality evapotranspiration is likely enhanced by irrigation, which is also unmodeled. Moreover, in situ measurements of shallow groundwater show no trend, suggesting that the trends are erroneously introduced by the assimilation into the modeled shallow groundwater, when in reality the groundwater is depleted in deeper aquifers. The results emphasize the importance of representing anthropogenic processes in land surface modeling and data assimilation systems.

  20. Improving water quality forecasting via data assimilation - Application of maximum likelihood ensemble filter to HSPF

    NASA Astrophysics Data System (ADS)

    Kim, Sunghee; Seo, Dong-Jun; Riazi, Hamideh; Shin, Changmin

    2014-11-01

    An ensemble data assimilation (DA) procedure is developed and evaluated for the Hydrologic Simulation Program - Fortran (HSPF), a widely used watershed water quality model. The procedure aims at improving the accuracy of short-range water quality prediction by updating the model initial conditions (IC) based on real-time observations of hydrologic and water quality variables. The observations assimilated include streamflow, biochemical oxygen demand (BOD), dissolved oxygen (DO), chlorophyll a (CHL-a), nitrate (NO3), phosphate (PO4) and water temperature (TW). The DA procedure uses the maximum likelihood ensemble filter (MLEF), which is capable of handling both nonlinear model dynamics and nonlinear observation equations, in a fixed-lag smoother formulation. For evaluation, the DA procedure was applied to the Kumho Catchment of the Nakdong River Basin in the Republic of Korea. A set of performance measures was used to evaluate analysis and prediction of streamflow and water quality variables. To remove systematic errors in the model simulation originating from structural and parametric errors, a parsimonious bias correction procedure is incorporated into the observation equation. The results show that the DA procedure substantially improves predictive skill for most variables; reduction in root mean square error ranges from 11% to 60% for Day-1 through 3 predictions for all observed variables except DO. It is seen that MLEF handles highly nonlinear hydrologic and biochemical observation equations very well, and that it is an effective DA technique for water quality forecasting.

  1. Estimating Hydrologic Fluxes, Crop Water Use, and Agricultural Land Area in China using Data Assimilation

    NASA Astrophysics Data System (ADS)

    Smith, Tiziana; McLaughlin, Dennis B.; Hoisungwan, Piyatida

    2016-04-01

    Crop production has significantly altered the terrestrial environment by changing land use and by altering the water cycle through both co-opted rainfall and surface water withdrawals. As the world's population continues to grow and individual diets become more resource-intensive, the demand for food - and the land and water necessary to produce it - will continue to increase. High-resolution quantitative data about water availability, water use, and agricultural land use are needed to develop sustainable water and agricultural planning and policies. However, existing data covering large areas with high resolution are susceptible to errors and can be physically inconsistent. China is an example of a large area where food demand is expected to increase and a lack of data clouds the resource management dialogue. Some assert that China will have insufficient land and water resources to feed itself, posing a threat to global food security if they seek to increase food imports. Others believe resources are plentiful. Without quantitative data, it is difficult to discern if these concerns are realistic or overly dramatized. This research presents a quantitative approach using data assimilation techniques to characterize hydrologic fluxes, crop water use (defined as crop evapotranspiration), and agricultural land use at 0.5 by 0.5 degree resolution and applies the methodology in China using data from around the year 2000. The approach uses the principles of water balance and of crop water requirements to assimilate existing data with a least-squares estimation technique, producing new estimates of water and land use variables that are physically consistent while minimizing differences from measured data. We argue that this technique for estimating water fluxes and agricultural land use can provide a useful basis for resource management modeling and policy, both in China and around the world.

  2. Improved water-cooled cyclone constructions in CFBs

    SciTech Connect

    Alliston, M.G.; Luomaharju, T.; Kokko, A.

    1999-07-01

    The construction of CFB boilers has advanced in comparison with early designs. One improvement has been the use of water or steam cooled cyclones, which allows the use of thin refractories and minimizes maintenance needs. Cooled cyclones are also tolerant of wide load variations when the main fuel is biologically based, and coal or some other fuel is used as a back-up. With uncooled cyclones, load changes with high volatile fuels can mean significant temperature transients in the refractory, due to post-combustion phenomena in the cyclone. Kvaerner's development of water-cooled cyclones for CFBs began in the early 1980s. The first boiler with this design was delivered in 1985 in Sweden. Since then, Kvaerner Pulping has delivered over twenty units with cooled cyclones, in capacity ranging from small units up to 400 MW{sub th}. Among these units, Kvaerner has developed unconventional solutions for CFBs, in order to simplify the constructions and to increase the reliability for different applications. The first of them was CYMIC{reg{underscore}sign}, which has its water-cooled cyclone built inside the boiler furnace. There are two commercial CYMIC boilers in operation and one in project stages. The largest CYMIC in operation is a 185 MW{sub th} industrial boiler burning various fuels. For even larger scale units Kvaerner developed the Integrated Cylindrical Cyclone and Loopseal (ICCL) assembly. One of these installations is in operation in USA, having steaming capacity of over 500 t/h. The design bases of these new solutions are quite different in comparison with conventional cyclones. Therefore, an important part of the development has been cold model testing and mathematical modeling of the cyclones. This paper reviews the state-of-the-art in water-cooled cyclone construction. The new solutions, their full-scale experience, and a comparison of the actual experience with the preliminary modeling work are introduced.

  3. POOL WATER TREATMENT AND COOLING SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    V. King

    2000-06-19

    The Pool Water Treatment and Cooling System is located in the Waste Handling Building (WHB), and is comprised of various process subsystems designed to support waste handling operations. This system maintains the pool water temperature within an acceptable range, maintains water quality standards that support remote underwater operations and prevent corrosion, detects leakage from the pool liner, provides the capability to remove debris from the pool, controls the pool water level, and helps limit radiological exposure to personnel. The pool structure and liner, pool lighting, and the fuel staging racks in the pool are not within the scope of the Pool Water Treatment and Cooling System. Pool water temperature control is accomplished by circulating the pool water through heat exchangers. Adequate circulation and mixing of the pool water is provided to prevent localized thermal hotspots in the pool. Treatment of the pool water is accomplished by a water treatment system that circulates the pool water through filters, and ion exchange units. These water treatment units remove radioactive and non-radioactive particulate and dissolved solids from the water, thereby providing the water clarity needed to conduct waste handling operations. The system also controls pool water chemistry to prevent advanced corrosion of the pool liner, pool components, and fuel assemblies. Removal of radioactivity from the pool water contributes to the project ALARA (as low as is reasonably achievable) goals. A leak detection system is provided to detect and alarm leaks through the pool liner. The pool level control system monitors the water level to ensure that the minimum water level required for adequate radiological shielding is maintained. Through interface with a demineralized water system, adequate makeup is provided to compensate for loss of water inventory through evaporation and waste handling operations. Interface with the Site Radiological Monitoring System provides continuous

  4. Analyzing the possibility of achieving more efficient cooling of water in the evaporative cooling towers of the Armenian NPP

    NASA Astrophysics Data System (ADS)

    Petrosyan, V. G.; Yeghoyan, E. A.

    2015-10-01

    The specific features of the service cooling water system used at the Armenian NPP and modifications made in the arrangement for supplying water to the water coolers in order to achieve more efficient cooling are presented. The mathematical model applied in carrying out the analyses is described, the use of which makes it possible to investigate the operation of parallel-connected cooling towers having different hydraulic and thermal loads. When the third standby cooling tower is put into operation (with the same flow rate of water supplied to the water coolers), the cooled water temperature is decreased by around 2-3°C in the range of atmospheric air temperatures 0-35°C. However, the introduced water distribution arrangement with a decreased spraying density has limitation on its use at negative outdoor air temperatures due to the hazard intense freezing of the fill in the cooling tower peripheral zone. The availability of standby cooling towers in the shutdown Armenian NPP power unit along with the planned full replacement of the cooling tower process equipment create good possibilities for achieving a deeper water cooling extent and better efficiency of the NPP. The present work was carried out with the aim of achieving maximally efficient use of existing possibilities and for elaborating the optimal cooling tower modernization version. Individual specific heat-andmass transfer processes in the chimney-type evaporative cooling towers are analyzed. An improved arrangement for distributing cooled water over the cooling tower spraying area (during its operation with a decreased flow rate) is proposed with the aim of cooling water to a deeper extent and preserving the possibility of using the cooling towers in winter. The main idea behind improving the existing arrangement is to exclude certain zones of the cooling tower featuring inefficient cooling from operation. The effectiveness of introducing the proposed design is proven by calculations (taking as an

  5. Computational Simulation of a Water-Cooled Heat Pump

    NASA Technical Reports Server (NTRS)

    Bozarth, Duane

    2008-01-01

    A Fortran-language computer program for simulating the operation of a water-cooled vapor-compression heat pump in any orientation with respect to gravity has been developed by modifying a prior general-purpose heat-pump design code used at Oak Ridge National Laboratory (ORNL).

  6. 49. LOOKING NORTH AT EVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. LOOKING NORTH AT EVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS, WITH BLOW ENGINE HOUSE No. 3 ON RIGHT, AND FILTER CAKE HOUSE IN FOREGROUND. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  7. Program for monitoring LDB concentrations in cooling-tower waters

    SciTech Connect

    Porter, W.E.

    1983-01-01

    A brief description is presented in tabular form describing the program employed by the Industrial Hygiene Department of the Oak Ridge National Laboratory to monitor and control levels of Legionella in cooling tower waters. Guidelines are listed to protect personnel from an exposure that could lead to legionnaire's disease.

  8. Maximum Likelihood Ensemble Filter-based Data Assimilation with HSPF for Improving Water Quality Forecasting

    NASA Astrophysics Data System (ADS)

    Kim, S.; Riazi, H.; Shin, C.; Seo, D.

    2013-12-01

    Due to the large dimensionality of the state vector and sparsity of observations, the initial conditions (IC) of water quality models are subject to large uncertainties. To reduce the IC uncertainties in operational water quality forecasting, an ensemble data assimilation (DA) procedure for the Hydrologic Simulation Program - Fortran (HSPF) model has been developed and evaluated for the Kumho River Subcatchment of the Nakdong River Basin in Korea. The procedure, referred to herein as MLEF-HSPF, uses maximum likelihood ensemble filter (MLEF) which combines strengths of variational assimilation (VAR) and ensemble Kalman filter (EnKF). The Control variables involved in the DA procedure include the bias correction factors for mean areal precipitation and mean areal potential evaporation, the hydrologic state variables, and the water quality state variables such as water temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), ammonium (NH4), nitrate (NO3), phosphate (PO4) and chlorophyll a (CHL-a). Due to the very large dimensionality of the inverse problem, accurately specifying the parameters for the DA procdedure is a challenge. Systematic sensitivity analysis is carried out for identifying the optimal parameter settings. To evaluate the robustness of MLEF-HSPF, we use multiple subcatchments of the Nakdong River Basin. In evaluation, we focus on the performance of MLEF-HSPF on prediction of extreme water quality events.

  9. Copper corrosion & clogging in APS deionized water cooling system

    NASA Astrophysics Data System (ADS)

    Adak, Bijaya

    An extensive amount of work has been performed on copper corrosion in last century due to its abundant use in domestic and industrial water systems. However, work on copper corrosion in deionized water is very limited. The water cooling system of Advanced Photon Source (APS) at Argonne National Laboratory uses deionized water containing very low dissolved oxygen (less than 10 ppb). Therefore, It is expected that copper corrosion would be less in this system. On the contrary, APS suffers significant clogging in its water cooling circuit resulting from the deposition of corrosion product and carries out frequent expensive maintenance to retain the required flow rate. The location of pH and corrosion potential of APS water cooling system is very close to the boundary condition of the two oxides (CuO and Cu 2O) of the Pourbaix diagram of copper. While a single phase presence of either of these two oxides is stable as a protective layer, a mixture of the two oxides is unstable. An unstable protective layer results in spalling of the oxide layer. A fluctuation in water chemistry (which is common in an industrial facility) triggers a phase transformation between these two oxides due to its near boundary values. It was observed that the location of pH and corrosion potential was away from the boundaries in high dissolved oxygen condition (more than 2000 ppm). Hence, the possibility of phase transformation becomes lesser in high dissolved oxygen condition than in low dissolved oxygen condition. A test station, that was a replica of the APS water cooling system, was used to perform experiments in both high and low oxygen condition. It was demonstrated that high oxygen condition results in less clogging than in low oxygen condition. Microstructural characterization was performed on the coupons from test station and on some components from APS to evaluate oxide surface and determine phases. Mechanism of the phase transformation was suggested.

  10. Water immersion for post incident cooling of firefighters; a review of practical fire ground cooling modalities.

    PubMed

    Brearley, Matt; Walker, Anthony

    2015-01-01

    Rapidly cooling firefighters post emergency response is likely to increase the operational effectiveness of fire services during prolonged incidents. A variety of techniques have therefore been examined to return firefighters core body temperature to safe levels prior to fire scene re-entry or redeployment. The recommendation of forearm immersion (HFI) in cold water by the National Fire and Protection Association preceded implementation of this active cooling modality by a number of fire services in North America, South East Asia and Australia. The vascularity of the hands and forearms may expedite body heat removal, however, immersion of the torso, pelvis and/or lower body, otherwise known as multi-segment immersion (MSI), exposes a greater proportion of the body surface to water than HFI, potentially increasing the rates of cooling conferred. Therefore, this review sought to establish the efficacy of HFI and MSI to rapidly reduce firefighters core body temperature to safe working levels during rest periods. A total of 38 studies with 55 treatments (43 MSI, 12 HFI) were reviewed. The core body temperature cooling rates conferred by MSI were generally classified as ideal (n = 23) with a range of ~0.01 to 0.35 °C min(-1). In contrast, all HFI treatments resulted in unacceptably slow core body temperature cooling rates (~0.01 to 0.05 °C min(-1)). Based upon the extensive field of research supporting immersion of large body surface areas and comparable logistics of establishing HFI or MSI, it is recommended that fire and rescue management reassess their approach to fireground rehabilitation of responders. Specifically, we question the use of HFI to rapidly lower firefighter core body temperature during rest periods. By utilising MSI to restore firefighter Tc to safe working levels, fire and rescue services would adopt an evidence based approach to maintaining operational capability during arduous, sustained responses. While the optimal MSI protocol will be

  11. Multifrequency airborne passive microwave assimilation to estimate snow water equivalent: a particle filter approach

    NASA Astrophysics Data System (ADS)

    Kim, R. S.; Durand, M. T.

    2016-12-01

    This paper presents and illustrates improved retrieval method of snow water equivalent (SWE) from airborne passive microwave (PM) measurements. A particle filter approach is proposed to assimilate PM brightness temperature (Tb) data in order to update snowpack states in a land surface model and demonstrates compared to ensemble Kalman filter (EnKF) method. The methods were applied over the Yampa river basin in the Colorado Rockies within the NASA Cold Land Processes Experiment (CLPX) area of 2002-2003. Forcing data is derived from the North American Land Data Assimilation v2 (NLDAS-2) dataset and Microwave Emission Model of Layered Snowpacks (MEMLS) is used to convert the snow state variables to Tb. The effects of vegetation and atmosphere are included in the radiative transfer model (RTM). Multifrequency measurements of PSR (Polarimetric Scanning Radiometer) are used and assimilated into model predictions of SWE at 120-m spatial resolution. The contributions of each channel to recover the true SWE are computed and analyzed. The SWE estimation is validated against SNOTEL and snow course observations.

  12. Effects of chlorobrominated and chlorinated cooling waters on estuarine organisms

    SciTech Connect

    Liden, L.H.; Burton, D.T.; Bongers, L.H.; Holland, A.F.

    1980-01-01

    Research report:Continuous-flow bioassays were conducted during August 1976 to compare the effects of chlorobrominated and chlorinated condenser cooling effluents on several selected estuarine food-chain organisms. Two fish species, two bivalve species, a copepod, and naturally occurring phytoplankton communities were studied. Toxic effects of chlorobrominated and chlorinated power plant cooling waters on estuarine organisms appear to be similar with respect to the lethal and sublethal response indicators used in the study. However, more comparative tests must be conducted to define any differences in toxicities of bromine chloride or chlorine residual oxidants. (50 references, 5 tables)

  13. Hybrid ensemble 4DVar assimilation of stratospheric ozone using a global shallow water model

    NASA Astrophysics Data System (ADS)

    Allen, Douglas R.; Hoppel, Karl W.; Kuhl, David D.

    2016-07-01

    Wind extraction from stratospheric ozone (O3) assimilation is examined using a hybrid ensemble 4-D variational assimilation (4DVar) shallow water model (SWM) system coupled to the tracer advection equation. Stratospheric radiance observations are simulated using global observations of the SWM fluid height (Z), while O3 observations represent sampling by a typical polar-orbiting satellite. Four ensemble sizes were examined (25, 50, 100, and 1518 members), with the largest ensemble equal to the number of dynamical state variables. The optimal length scale for ensemble localization was found by tuning an ensemble Kalman filter (EnKF). This scale was then used for localizing the ensemble covariances that were blended with conventional covariances in the hybrid 4DVar experiments. Both optimal length scale and optimal blending coefficient increase with ensemble size, with optimal blending coefficients varying from 0.2-0.5 for small ensembles to 0.5-1.0 for large ensembles. The hybrid system outperforms conventional 4DVar for all ensemble sizes, while for large ensembles the hybrid produces similar results to the offline EnKF. Assimilating O3 in addition to Z benefits the winds in the hybrid system, with the fractional improvement in global vector wind increasing from ˜ 35 % with 25 and 50 members to ˜ 50 % with 1518 members. For the smallest ensembles (25 and 50 members), the hybrid 4DVar assimilation improves the zonal wind analysis over conventional 4DVar in the Northern Hemisphere (winter-like) region and also at the Equator, where Z observations alone have difficulty constraining winds due to lack of geostrophy. For larger ensembles (100 and 1518 members), the hybrid system results in both zonal and meridional wind error reductions, relative to 4DVar, across the globe.

  14. Cooling of Gas Turbines. 6 - Computed Temperature Distribution through Cross Section of Water-Cooled Turbine Blade

    DTIC Science & Technology

    1947-05-01

    AERONAUTICS Figure 7. - Cross section of water-cooleä turbine blade showing location and size of seven coolant...Power Plants.~ Jet and~ Turbine ($) [SECTION. Turbines (I3) [CROSS DEFERENCES. Turbine blades - Thermal measurements (95350); Turbine blades ...section of water-cooled turbine blade FORG’N. TITLE: v.. ’V, ORIGINATING AGENCY. TRANSLATION. National Advisory Committee for Aeronautics

  15. Water pressure and flow regulation for water-cooled lasers.

    PubMed

    Chambers, J K; Talansky, M L

    1988-05-01

    We experienced laser water valve failure resulting from poor water quality, frequent laser shutdowns from low water flow rates, and unnecessary service calls shortly after installing a new laser. The water valve failure resulted from deposits and corrosion. A dirt/rust water filter was installed, and no further water valve failure has occurred. A flow meter was added to the water system to adjust flow rates. It clearly shows when laser shutdowns are caused by low flow rates and indicates the need for water filter changes. Water pressure was monitored and is most affected by use of the laser. A convenient electric water control, activated by the laser key switch, has proved to be reliable. The water control is kept open by a timer ten minutes after the laser is shut off. We determined that our laser shutdowns were related to transient drops in water flow rates and possibly to draw off of water in other parts of the hospital.

  16. Gasifier waste water treatment: Phase I cooling tower assessment

    SciTech Connect

    Mann, M.D.; Willson, W.G.; Hendrikson, J.G.; Winton, S.L.

    1985-02-01

    Details of an advanced study of the treatability of waste waters from the fixed-bed gasification of lignite describe the test equipment and results at a pilot plant in North Dakota using stripped-gas liquor (SGL) as cooling tower makeup. Ammonia, alkalinity, phenol, and other non-hydantoin organics were removed from the cooling water by stripping and/or biological degradation, with the phenol concentration in the exhaust air exceeding the odor threshold. It will be necessary to control foaming of the circulating water, but both glycol and silicon based agents performed well during the test. It will also be necessary to reduce the high level of biofouling on heat transfer surfaces, although stainless steel fouling was not a major problem. The conclusion is that SGL is limited by potentially serious operating problems without additional treatment. 5 references, 4 figures, 7 tables.

  17. Computation of infrared cooling rates in the water vapor bands

    NASA Technical Reports Server (NTRS)

    Chou, M. D.; Arking, A.

    1978-01-01

    A fast but accurate method for calculating the infrared radiative terms due to water vapor has been developed. It makes use of the far wing approximation to scale transmission along an inhomogeneous path to an equivalent homogeneous path. Rather than using standard conditions for scaling, the reference temperatures and pressures are chosen in this study to correspond to the regions where cooling is most significant. This greatly increased the accuracy of the new method. Compared to line by line calculations, the new method has errors up to 4% of the maximum cooling rate, while a commonly used method based upon the Goody band model (Rodgers and Walshaw, 1966) introduces errors up to 11%. The effect of temperature dependence of transmittance has also been evaluated; the cooling rate errors range up to 11% when the temperature dependence is ignored. In addition to being more accurate, the new method is much faster than those based upon the Goody band model.

  18. Water cooled silicon crystals for X-ray monochromators

    NASA Astrophysics Data System (ADS)

    Wahl, R.; Shah, R.; Jackson, K.; Tonnessen, T.

    1992-07-01

    Insertion devices (wigglers and undulators) proposed for synchrotron radiation sources will produce up to 10 kW/cm2 of thermal loading. In a double crystal monochromator, the first crystal must absorb nearly all of this output power, as it diffracts the desired wavelength to the second crystal. Storage rings currently projected or under construction produce heat loads of this intensity and thus require significantly improved optical element cooling methods to preserve the spectral quality of the output radiation. As beam intensities reach these higher levels, analysis of the thermal performance of passive and actively cooled optical elements becomes more and more critical because such elements are a cost effective means for producing a cooled crystal that performs to its design specifications the first time it is installed in the beamline. The Rocketdyne Division of Rockwell International is applying the experience gained in high energy laser optics research (the design of cooled IR and UV optical components for free electron lasers) to the problems of cooled X-ray monochromator crystals and grazing incidence VUV optics. In this paper, a set of first order parametric calculations and a second order finite element calculation were performed to determine surface temperature rise, coolant pressure drop and surface distortion in a single crystal silicon heat exchanger with heat loads of 100 to 550 W/cm2. Two different heat exchanger designs (microchannels and pin post cell) and two different coolants (water and liquid gallium) were analyzed to assess performance advantages of each.

  19. Experimental soil warming and cooling alters the partitioning of recent assimilates: evidence from a (14)C-labelling study at the alpine treeline.

    PubMed

    Ferrari, A; Hagedorn, F; Niklaus, P A

    2016-05-01

    Despite concerns about climate change effects on ecosystems functioning, little is known on how plant assimilate partitioning changes with temperature. Particularly, large temperature effects might occur in cold ecosystems where critical processes are at their temperature limit. In this study, we tested temperature effects on carbon (C) assimilate partitioning in a field experiment at the alpine treeline. We warmed and cooled soils of microcosms planted with Pinus mugo or Leucanthemopsis alpina, achieving daily mean soil temperatures (3-10 cm depth) around 5.8, 12.7 and 19.2 °C in cooled, control and warmed soils. We pulse-labelled these systems with (14)CO2 for one photoperiod and traced (14)C over the successive 4 days. Plant net (14)C uptake increased steadily with soil temperature. However, (14)C amounts in fungal hyphae, soil microbial biomass, soil organic matter, and soil respiration showed a non-linear response to temperature. This non-linear pattern was particularly pronounced in P. mugo, with five times higher (14)C activities in cooled compared to control soils, but no difference between warmed and control soil. Autoradiographic analysis of the spatial distribution of (14)C in soils indicated that temperature effects on the vertical label distribution within soils depended on plant species. Our results show that plant growth, in particular root metabolism, is limited by low soil temperature. As a consequence, positive temperature effects on net C uptake may not be paralleled by similar changes in rhizodeposition. This has important implications for predictions of soil C storage, because rhizodeposits and plant biomass vary strongly in their residence times.

  20. Ensemble Data Assimilation with HSPF for Improved Real-Time Water Quality Forecasting

    NASA Astrophysics Data System (ADS)

    Kim, S.; Riazi, H.; rafieei nasab, A.; Shin, C.; Seo, D.

    2013-05-01

    An ensemble data assimilation (DA) procedure for the Hydrologic Simulation Program - Fortran (HSPF) model has been developed, tested and evaluated for implementation in real-time water quality forecasting. The procedure, referred to herein as MLEF-HSPF, uses maximum likelihood ensemble filter (MLEF) which combines strengths of variational assimilation (VAR) and ensemble Kalman filter (EnKF). To evaluate the procedure, MLEF-HSPF was run daily for a 2-yr period for the Kumho River Subbasin of the Nakdong River Basin in Korea. A set of performance measures was used to assess the marginal value of DA-aided predictions of stream flow and water quality variables such as water temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), ammonium (NH4), nitrate (NO3), phosphate (PO4) and chlorophyll a. Due to large dimensionality of the state vector and complexity of the biochemical processes involved, DA with HSPF poses additional challenges. In this presentation, we describe MLEF-HSPF, summarize the evaluation results and identify the challenges.

  1. Deployment Scenario of Heavy Water Cooled Thorium Breeder Reactor

    SciTech Connect

    Mardiansah, Deby; Takaki, Naoyuki

    2010-06-22

    Deployment scenario of heavy water cooled thorium breeder reactor has been studied. We have assumed to use plutonium and thorium oxide fuel in water cooled reactor to produce {sup 233}U which will be used in thorium breeder reactor. The objective is to analysis the potential of water cooled Th-Pu reactor for replacing all of current LWRs especially in Japan. In this paper, the standard Pressurize Water Reactor (PWR) has been designed to produce 3423 MWt; (i) Th-Pu PWR, (ii) Th-Pu HWR (MFR = 1.0) and (iii) Th-Pu HWR (MFR 1.2). The properties and performance of the core were investigated by using cell and core calculation code. Th-Pu PWR or HWR produces {sup 233}U to introduce thorium breeder reactor. The result showed that to replace all (60 GWe) LWR by thorium breeder reactor within a period of one century, Th-Pu oxide fueled PWR has insufficient capability to produce necessary amount of {sup 233}U and Th-Pu oxide fueled HWR has almost enough potential to produce {sup 233}U but shows positive void reactivity coefficient.

  2. Single-cell measurement of archaeal and bacterial carbon assimilation in dark Pacific Ocean waters

    NASA Astrophysics Data System (ADS)

    Dekas, A. E.; Mayali, X.; Parada, A. E.; Fuhrman, J. A.; Weber, P. K.; Pett-Ridge, J.

    2016-02-01

    Microbial activity in the dark ocean plays a critical role in nutrient and elemental cycling. Here, we investigated the activity of archaea and bacteria on the single-cell level during dark incubations of Pacific Ocean water, and specifically their capacity for chemoautotrophy. Samples were collected 19 km off the coast of Los Angeles, at a depth of 150 m, and off the coast of San Francisco, at the surface. Incubations were amended with isotopically-labeled organic or inorganic carbon (13C-bicarbonate, 15N-amino acids or dual-labeled 13C-15N-amino acids), and uptake was detected using nanoscale secondary ion mass spectrometry (NanoSIMS). We analyzed 4,968 individual cells using an automated NanoSIMS analysis with particle-recognition software. After 7 days, 95% and 89% of cells (deep and shallow, respectively) demonstrated anabolic activity, i.e., incorporation of at least one isotopically-labeled substrate. Chemoautotrophy was detected at both sites, with 36% and 9% of cells (deep and shallow, respectively) assimilating 13C-bicarbonate in the dark. Fluorescence in situ hybridization coupled to NanoSIMS analysis was performed to link 16S rRNA phylogeny to patterns of C-assimilation. Thaumarchaea were found to dominate chemoautotrophy at both sites, with 13C-bicarbonate assimilation in nearly all cells hybridized with the Cren537 probe, but none hybridized with a general bacterial probe (Eub338). Conversely, widespread assimilation of both 15N and 13C from 15N-13C-amino acids was observed in the bacterial assemblage, but not in the Thaumarchaea. Interestingly, Thaumarchaeal cells were enriched in 15N after incubation with 15N-13C-amino acids, but not 13C, suggesting selective N assimilation from amino acids or substrate recycling. Together, our results demonstrate the value of single-cell measurements in characterizing patterns of C metabolism in mixed microbial community, and underscore the importance of Thaumarchaea in marine chemoautotrophy.

  3. Diabatic forcing and initialization with assimilation of cloud and rain water in a forecast model: Methodology

    NASA Technical Reports Server (NTRS)

    Raymond, William H.; Olson, William S.; Callan, Geary

    1990-01-01

    The focus of this part of the investigation is to find one or more general modeling techniques that will help reduce the time taken by numerical forecast models to initiate or spin-up precipitation processes and enhance storm intensity. If the conventional data base could explain the atmospheric mesoscale flow in detail, then much of our problem would be eliminated. But the data base is primarily synoptic scale, requiring that a solution must be sought either in nonconventional data, in methods to initialize mesoscale circulations, or in ways of retaining between forecasts the model generated mesoscale dynamics and precipitation fields. All three methods are investigated. The initialization and assimilation of explicit cloud and rainwater quantities computed from conservation equations in a mesoscale regional model are examined. The physical processes include condensation, evaporation, autoconversion, accretion, and the removal of rainwater by fallout. The question of how to initialize the explicit liquid water calculations in numerical models and how to retain information about precipitation processes during the 4-D assimilation cycle are important issues that are addressed. The explicit cloud calculations were purposely kept simple so that different initialization techniques can be easily and economically tested. Precipitation spin-up processes associated with three different types of weather phenomena are examined. Our findings show that diabatic initialization, or diabatic initialization in combination with a new diabatic forcing procedure, work effectively to enhance the spin-up of precipitation in a mesoscale numerical weather prediction forecast. Also, the retention of cloud and rain water during the analysis phase of the 4-D data assimilation procedure is shown to be valuable. Without detailed observations, the vertical placement of the diabatic heating remains a critical problem.

  4. USE of mine pool water for power plant cooling.

    SciTech Connect

    Veil, J. A.; Kupar, J. M .; Puder, M. G.

    2006-11-27

    Water and energy production issues intersect in numerous ways. Water is produced along with oil and gas, water runs off of or accumulates in coal mines, and water is needed to operate steam electric power plants and hydropower generating facilities. However, water and energy are often not in the proper balance. For example, even if water is available in sufficient quantities, it may not have the physical and chemical characteristics suitable for energy or other uses. This report provides preliminary information about an opportunity to reuse an overabundant water source--ground water accumulated in underground coal mines--for cooling and process water in electric generating facilities. The report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL), which has implemented a water/energy research program (Feeley and Ramezan 2003). Among the topics studied under that program is the availability and use of ''non-traditional sources'' of water for use at power plants. This report supports NETL's water/energy research program.

  5. The determinants of thermal comfort in cool water.

    PubMed

    Guéritée, J; House, J R; Redortier, B; Tipton, M J

    2015-10-01

    Water-based activities may result in the loss of thermal comfort (TC). We hypothesized that in cooling water, the hands and feet would be responsible. Supine immersions were conducted in up to five clothing conditions (exposing various regions), as well as investigations to determine if a "reference" skin temperature (Tsk) distribution in thermoneutral air would help interpret our findings. After 10 min in 34.5 °C water, the temperature was decreased to 19.5 °C over 20 min; eight resting or exercising volunteers reported when they no longer felt comfortable and which region was responsible. TC, rectal temperature, and Tsk were measured. Rather than the extremities, the lower back and chest caused the loss of overall TC. At this point, mean (SD) chest Tsk was 3.3 (1.7) °C lower than the reference temperature (P = 0.005), and 3.8 (1.5) °C lower for the back (P = 0.002). Finger Tsk was 3.1 (2.7) °C higher than the reference temperature (P = 0.037). In cool and cooling water, hands and feet, already adapted to colder air temperatures, will not cause discomfort. Contrarily, more discomfort may arise from the chest and lower back, as these regions cool by more than normal. Thus, Tsk distribution in thermoneutral air may help understand variations in TC responses across the body.

  6. Effect of Cooling Water on Stability of NLC Linac Components

    SciTech Connect

    Le Pimpec, Frederic

    2002-11-01

    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.

  7. Effect of cooling water on stability of NLC linac components

    SciTech Connect

    F. Le Pimpec et al.

    2003-02-11

    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.

  8. Variational data assimilation with a semi-Lagrangian semi-implicit global shallow-water equation model and its adjoint

    NASA Technical Reports Server (NTRS)

    Li, Y.; Navon, I. M.; Courtier, P.; Gauthier, P.

    1993-01-01

    An adjoint model is developed for variational data assimilation using the 2D semi-Lagrangian semi-implicit (SLSI) shallow-water equation global model of Bates et al. with special attention being paid to the linearization of the interpolation routines. It is demonstrated that with larger time steps the limit of the validity of the tangent linear model will be curtailed due to the interpolations, especially in regions where sharp gradients in the interpolated variables coupled with strong advective wind occur, a synoptic situation common in the high latitudes. This effect is particularly evident near the pole in the Northern Hemisphere during the winter season. Variational data assimilation experiments of 'identical twin' type with observations available only at the end of the assimilation period perform well with this adjoint model. It is confirmed that the computational efficiency of the semi-Lagrangian scheme is preserved during the minimization process, related to the variational data assimilation procedure.

  9. Experimental Studies of NGNP Reactor Cavity Cooling System With Water

    SciTech Connect

    Corradini, Michael; Anderson, Mark; Hassan, Yassin; Tokuhiro, Akira

    2013-01-16

    This project will investigate the flow behavior that can occur in the reactor cavity cooling system (RCCS) with water coolant under the passive cooling-mode of operation. The team will conduct separate-effects tests and develop associated scaling analyses, and provide system-level phenomenological and computational models that describe key flow phenomena during RCCS operation, from forced to natural circulation, single-phase flow and two-phase flow and flashing. The project consists of the following tasks: Task 1. Conduct separate-effects, single-phase flow experiments and develop scaling analyses for comparison to system-level computational modeling for the RCCS standpipe design. A transition from forced to natural convection cooling occurs in the standpipe under accident conditions. These tests will measure global flow behavior and local flow velocities, as well as develop instrumentation for use in larger scale tests, thereby providing proper flow distribution among standpipes for decay heat removal. Task 2. Conduct separate-effects experiments for the RCCS standpipe design as two-phase flashing occurs and flow develops. As natural circulation cooling continues without an ultimate heat sink, water within the system will heat to temperatures approaching saturation , at which point two-phase flashing and flow will begin. The focus is to develop a phenomenological model from these tests that will describe the flashing and flow stability phenomena. In addition, one could determine the efficiency of phase separation in the RCCS storage tank as the two-phase flashing phenomena ensues and the storage tank vents the steam produced. Task 3. Develop a system-level computational model that will describe the overall RCCS behavior as it transitions from forced flow to natural circulation and eventual two-phase flow in the passive cooling-mode of operation. This modeling can then be used to test the phenomenological models developed as a function of scale.

  10. Carbon assimilation and water-use efficiency by neighboring Mediterranean-climate oaks that differ in water access.

    PubMed

    Goulden, M L

    1996-04-01

    Quercus agrifolia Nee and Quercus durata Jeps. are sclerophyllous evergreens that co-occur in regions of northern California that have a serpentine-derived soil. The species are of similar stature and density where they grow together, even though late-drought xylem pressure potentials indicate that Q. durata has access to more soil water than Q. agrifolia. To assess how carbon uptake and water-use efficiency (WUE) are affected by water access, I monitored leaf and canopy gas exchange of neighboring Q. durata and Q. agrifolia trees over a 15-month period. Transpiration and photosynthesis by Q. agrifolia peaked in spring and declined through the summer, whereas transpiration and photosynthesis by Q. durata continued at a moderate rate year round. When summed over the study, Q. agrifolia transpired 25% less water on a ground-area basis than Q. durata, but assimilated 25% more carbon. Quercus agrifolia achieved a greater integrated WUE by: (1) maintaining a 20% advantage in instantaneous WUE as a result of lower leaf intercellular CO(2) concentrations; (2) responding rapidly to increased soil water following rain; and (3) assimilating carbon at high rates during periods of low evaporative demand.

  11. EFFECT OF OZONATED WATER ON THE ASSIMILABLE ORGANIC CARBON AND COLIFORM GROWTH RESPONSE VALUES AND ON PATHOGENIC BACTERIA SURVIVAL

    EPA Science Inventory

    The assimilable organic carbon (AOC) and coliform growth response (CGR) are bioassays used to determine water quality. AOC and CGR are better indexes in determining whether water can support the growth of bacteria than biological oxygen demand (BOD). The AOC value of reconditione...

  12. EFFECT OF OZONATED WATER ON THE ASSIMILABLE ORGANIC CARBON AND COLIFORM GROWTH RESPONSE VALUES AND ON PATHOGENIC BACTERIA SURVIVAL

    EPA Science Inventory

    The assimilable organic carbon (AOC) and coliform growth response (CGR) are bioassays used to determine water quality. AOC and CGR are better indexes in determining whether water can support the growth of bacteria than biological oxygen demand (BOD). The AOC value of reconditione...

  13. 40 CFR 463.10 - Applicability; description of the contact cooling and heating water subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... contact cooling and heating water subcategory. 463.10 Section 463.10 Protection of Environment... FORMING POINT SOURCE CATEGORY Contact Cooling and Heating Water Subcategory § 463.10 Applicability; description of the contact cooling and heating water subcategory. This subpart applies to discharges...

  14. 40 CFR 463.10 - Applicability; description of the contact cooling and heating water subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... contact cooling and heating water subcategory. 463.10 Section 463.10 Protection of Environment... FORMING POINT SOURCE CATEGORY Contact Cooling and Heating Water Subcategory § 463.10 Applicability; description of the contact cooling and heating water subcategory. This subpart applies to discharges...

  15. 78 FR 35330 - Initial Test Programs for Water-Cooled Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-12

    ... COMMISSION Initial Test Programs for Water-Cooled Nuclear Power Plants AGENCY: Nuclear Regulatory Commission... revision to Regulatory Guide (RG), 1.68, ``Initial Test Programs for Water-Cooled Nuclear Power Plants... Initial Test Programs (ITPs) for light water cooled nuclear power plants. ADDRESSES: Please refer to...

  16. The water-water cycle in leaves is not a major alternative electron sink for dissipation of excess excitation energy when CO(2) assimilation is restricted.

    PubMed

    Driever, Steven M; Baker, Neil R

    2011-05-01

    Electron flux from water via photosystem II (PSII) and PSI to oxygen (water-water cycle) may provide a mechanism for dissipation of excess excitation energy in leaves when CO(2) assimilation is restricted. Mass spectrometry was used to measure O(2) uptake and evolution together with CO(2) uptake in leaves of French bean and maize at CO(2) concentrations saturating for photosynthesis and the CO(2) compensation point. In French bean at high CO(2) and low O(2) concentrations no significant water-water cycle activity was observed. At the CO(2) compensation point and 3% O(2) a low rate of water-water cycle activity was observed, which accounted for 30% of the linear electron flux from water. In maize leaves negligible water-water cycle activity was detected at the compensation point. During induction of photosynthesis in maize linear electron flux was considerably greater than CO(2) assimilation, but no significant water-water cycle activity was detected. Miscanthus × giganteus grown at chilling temperature also exhibited rates of linear electron transport considerably in excess of CO(2) assimilation; however, no significant water-water cycle activity was detected. Clearly the water-water cycle can operate in leaves under some conditions, but it does not act as a major sink for excess excitation energy when CO(2) assimilation is restricted. © 2011 Blackwell Publishing Ltd.

  17. Coagulation chemistries for silica removal from cooling tower water.

    SciTech Connect

    Nyman, May Devan; Altman, Susan Jeanne; Stewart, Tom

    2010-02-01

    The formation of silica scale is a problem for thermoelectric power generating facilities, and this study investigated the potential for removal of silica by means of chemical coagulation from source water before it is subjected to mineral concentration in cooling towers. In Phase I, a screening of many typical as well as novel coagulants was carried out using concentrated cooling tower water, with and without flocculation aids, at concentrations typical for water purification with limited results. In Phase II, it was decided that treatment of source or make up water was more appropriate, and that higher dosing with coagulants delivered promising results. In fact, the less exotic coagulants proved to be more efficacious for reasons not yet fully determined. Some analysis was made of the molecular nature of the precipitated floc, which may aid in process improvements. In Phase III, more detailed study of process conditions for aluminum chloride coagulation was undertaken. Lime-soda water softening and the precipitation of magnesium hydroxide were shown to be too limited in terms of effectiveness, speed, and energy consumption to be considered further for the present application. In Phase IV, sodium aluminate emerged as an effective coagulant for silica, and the most attractive of those tested to date because of its availability, ease of use, and low requirement for additional chemicals. Some process optimization was performed for coagulant concentration and operational pH. It is concluded that silica coagulation with simple aluminum-based agents is effective, simple, and compatible with other industrial processes.

  18. Collisional cooling investigation of THz rotational transitions of water

    SciTech Connect

    Dick, Michael J.; Drouin, Brian J.; Pearson, John C.

    2010-02-15

    An investigation of the pressure broadening by helium and hydrogen of six rotational transitions of water has been completed. The six transitions studied included two para water transitions (0{sub 00}-1{sub 11} and 1{sub 11}-2{sub 02}) and four ortho water transitions (1{sub 01}-1{sub 10}, 2{sub 21}-3{sub 12}, 3{sub 03}-3{sub 12} and 3{sub 12}-3{sub 21}) in the frequency region 0.55-1.17 THz. This survey was accomplished using the collisional cooling technique which allowed the broadening of each transition to be studied below the water condensation temperature. For each of the transitions studied, the temperature dependence of the pressure broadening by helium showed little dependence on temperature, while the broadening by hydrogen showed a sharp decrease at the lowest temperatures. This behavior was modeled, for each transition broadened by helium and hydrogen, with a power law, or a power law modified with a Boltzmann-like step function, and the results of these fits will be presented. In addition, an extensive investigation of the systematic error in the temperature of the water vapor in the collisional cooling experiment will be discussed. Finally, the impact of these new broadening measurements on models of star formation in the interstellar medium will be outlined.

  19. Operational water quality forecasting with EnKF data assimilation in the Yeongsan river basin, Korea

    NASA Astrophysics Data System (ADS)

    Shin, Changmin; Kim, Kyunghyun; Min, Joong-Hyuk; Na, Eunhye; Park, Suyoung; Song, Hyunoh

    2016-04-01

    National institute of environmental research(NIER) have been operating the water quality forecasting to prevent water quality deterioration for the major rivers in South Korea through WQFS-NIER(Water Quality Forecasting System) which developed based on Delft-FEWS system by the international joint research with NIER and Deltares from 2011 to 2013 The coupled the Hydrologic Simulation Program Fortran(HSPF) and the Environmental Fluid Dynamic Code(EFDC) models are being used to quantitatively predict the water quality. HSPF watershed model are used to generate the flows and water quality loads of the major tributaries which are used as the boundary conditions for EFDC model. The uncertainties in water quality forecasting are contributed by various factors such as input uncertainty, model structure uncertainty, parametric uncertainty, initial conditions uncertainty, of which to reduce uncertainty on the initial conditions is relatively effective in improving accuracy of short term water quality forecast. To reduce initial conditions uncertainties, ensemble Kalman filter(EnKF) data assimilation(DA) techniques are applied to the EFDC models. DA is to condition the model state on the observations to get a better estimate of state. Model error is assumed to come from uncertainties of the boundary conditions of EFDC model. The case study for Yeongsan river demonstrate that EnKF is successful in bringing the algae concentrations closer to the observations.

  20. Data assimilation of satellite-based actual evapotranspiration in a distributed hydrological model of a controlled water system

    NASA Astrophysics Data System (ADS)

    Hartanto, I. M.; van der Kwast, J.; Alexandridis, T. K.; Almeida, W.; Song, Y.; van Andel, S. J.; Solomatine, D. P.

    2017-05-01

    Advances in earth observation (EO) and spatially distributed hydrological modelling provide an opportunity to improve modelling of controlled water systems. In a controlled water system human interference is high, which may lead to incorrect parameterisation in the model calibration phase. This paper analyses whether assimilation of EO actual evapotranspiration (ETa) data can improve discharge simulation with a spatially distributed hydrological model of a controlled water system. The EO ETa estimates are in the form of eight-day ETa composite maps derived from Terra/MODIS images using the ITA-MyWater algorithm. This algorithm is based on the surface energy balance method and is calibrated for this research for a low-lying reclamation area with a heavily controlled water system: the Rijnland area in the Netherlands. Data assimilation (DA) with the particle filter method is applied to assimilate the ETa maps into a spatially distributed hydrological model. The hydrological model and DA framework are applied using the open source software SIMGRO and PCRaster-Python respectively. The analysis is done for a period between July and October 2013 in which a high discharge peak followed a long dry-spell. The assimilation of EO ETa resulted in local differences in modelled ETa compared to simulation without data assimilation, while the area average ETa remained almost the same. The modelled cumulative discharge graphs, with and without DA, showed distinctive differences with the simulation, with DA better matching the measured cumulative discharge. The bias of simulated cumulative discharge to the observed data reduced from 14% to 4% when using DA of EO ETa. These results showed that assimilating EO ETa may not only be effective in the more common applications of soil moisture and crop-growth modelling, but also for improving discharge modelling of controlled water systems.

  1. Assimilation of GRACE Terrestrial Water Storage Observations into a Land Surface Model for the Assessment of Regional Flood Potential

    NASA Technical Reports Server (NTRS)

    Reager, John T.; Thomas, Alys C.; Sproles, Eric A.; Rodell, Matthew; Beaudoing, Hiroko K.; Li, Bailing; Famiglietti, James S.

    2015-01-01

    We evaluate performance of the Catchment Land Surface Model (CLSM) under flood conditions after the assimilation of observations of the terrestrial water storage anomaly (TWSA) from NASA's Gravity Recovery and Climate Experiment (GRACE). Assimilation offers three key benefits for the viability of GRACE observations to operational applications: (1) near-real time analysis; (2) a downscaling of GRACE's coarse spatial resolution; and (3) state disaggregation of the vertically-integrated TWSA. We select the 2011 flood event in the Missouri river basin as a case study, and find that assimilation generally made the model wetter in the months preceding flood. We compare model outputs with observations from 14 USGS groundwater wells to assess improvements after assimilation. Finally, we examine disaggregated water storage information to improve the mechanistic understanding of event generation. Validation establishes that assimilation improved the model skill substantially, increasing regional groundwater anomaly correlation from 0.58 to 0.86. For the 2011 flood event in the Missouri river basin, results show that groundwater and snow water equivalent were contributors to pre-event flood potential, providing spatially-distributed early warning information.

  2. Assimilation of GRACE Terrestrial Water Storage Observations into a Land Surface Model for the Assessment of Regional Flood Potential

    NASA Technical Reports Server (NTRS)

    Reager, John T.; Thomas, Alys C.; Sproles, Eric A.; Rodell, Matthew; Beaudoing, Hiroko K.; Li, Bailing; Famiglietti, James S.

    2015-01-01

    We evaluate performance of the Catchment Land Surface Model (CLSM) under flood conditions after the assimilation of observations of the terrestrial water storage anomaly (TWSA) from NASA's Gravity Recovery and Climate Experiment (GRACE). Assimilation offers three key benefits for the viability of GRACE observations to operational applications: (1) near-real time analysis; (2) a downscaling of GRACE's coarse spatial resolution; and (3) state disaggregation of the vertically-integrated TWSA. We select the 2011 flood event in the Missouri river basin as a case study, and find that assimilation generally made the model wetter in the months preceding flood. We compare model outputs with observations from 14 USGS groundwater wells to assess improvements after assimilation. Finally, we examine disaggregated water storage information to improve the mechanistic understanding of event generation. Validation establishes that assimilation improved the model skill substantially, increasing regional groundwater anomaly correlation from 0.58 to 0.86. For the 2011 flood event in the Missouri river basin, results show that groundwater and snow water equivalent were contributors to pre-event flood potential, providing spatially-distributed early warning information.

  3. Cool water vs warm water immersion for minimal sedation colonoscopy: a double-blind randomized trial.

    PubMed

    Falt, P; Šmajstrla, V; Fojtík, P; Tvrdík, J; Urban, O

    2013-01-01

    Water-aided insertion as an alternative colonoscopy technique reduces patient discomfort. Warm water has been used in most published trials, but the use of cool water is easier and, if equally effective, could support the use of the water-aided technique in routine practice. A double-blind, randomized, single-centre study was performed in which 201 patients were randomized to either cool (20-24 °C) or warm (37 °C) water immersion insertion. The primary outcome was caecal intubation time. The success rate of minimal sedation and patient discomfort were also assessed. The caecal intubation time for cool and warm water was similar (6.9 ± 3.5 vs 7.0 ± 3.4 min, P = 0.64). The respective success rates of minimal sedation colonoscopy (89.1% vs 90%, P = 1.00) and discomfort (P = 0.51) were no different. All other outcomes except a greater need for abdominal compression in the cool water arm (P = 0.04) were similar including the total procedure time, terminal ileum intubation rate, adenoma detection, length of the inserted scope, water volume, non-standard position rate, difficulty of the procedure and the patient's temperature sensation. The use of cool water did not modify the caecal intubation time compared with warm water. Exception for abdominal compression, all other end-points were no different. Cool water immersion is an alternative to the technically more demanding warm water immersion colonoscopy. Colorectal Disease © 2013 The Association of Coloproctology of Great Britain and Ireland.

  4. Investigation of assimilable organic carbon (AOC) and bacterial regrowth in drinking water distribution system.

    PubMed

    Liu, W; Wu, H; Wang, Z; Ong, S L; Hu, J Y; Ng, W J

    2002-02-01

    This paper investigated the variation of assimilable organic carbon (AOC) concentrations in water from several typical water treatment plants and distribution systems in a northern city of China. It is concluded from this study that: (1) The AOC in most of the product water of the studied water treatment plants and the water from the associated distribution systems could not meet the biostability criteria of 50-100 microg/L. (2) Only 4% of the measured AOC concentrations were less than 100 microg/L. However, about half of the measured AOC values were less than 200 microg/L. (3) Better source water quality resulted in lower AOC concentrations. (4) The variation of AOC concentrations in distribution systems was affected by chlorine oxidation and bacterial activity: the former resulted in an increase of AOC value while the latter led to a reduction in AOC. (5) The variation of AOC concentration followed different patterns in different distribution systems or different seasons due to their respective operational characteristics. (6) Less than 30% of AOC could be removed by a conventional treatment process, whereas 30-60% with a maximum of 50-60% could be removed by granular activated carbon (GAC). (7) The observation via scanning electron microscope (SEM) on distribution pipe tubercle samples demonstrated that the pipe inner wall was not smooth and bacteria multiplied in the crevice as well as in the interior wall of distribution pipes.

  5. What causes cooling water temperature gradients in forested stream reaches?

    NASA Astrophysics Data System (ADS)

    Garner, G.; Malcolm, I. A.; Sadler, J. P.; Hannah, D. M.

    2014-06-01

    Previous studies have suggested that shading by riparian vegetation may reduce maximum water temperature and provide refugia for temperature sensitive aquatic organisms. Longitudinal cooling gradients have been observed during the daytime for stream reaches shaded by coniferous trees downstream of clear cuts, or deciduous woodland downstream of open moorland. However, little is known about the energy exchange processes that drive such gradients, especially in semi-natural woodland contexts, and in the absence of potentially confounding cool groundwater inflows. To address this gap, this study quantified and modelled variability in stream temperature and heat fluxes along an upland reach of the Girnock Burn (a tributary of the Aberdeenshire Dee, Scotland) where riparian landuse transitions from open moorland to semi-natural forest. Observations were made along a 1050 m reach using a spatially-distributed network of ten water temperature micro-loggers, three automatic weather stations and >200 hemispherical photographs, which were used to estimate incoming solar radiation. These data parameterised a high-resolution energy flux model, incorporating flow-routing, which predicted spatio-temporal variability in stream temperature. Variability in stream temperature was controlled largely by energy fluxes at the water column-atmosphere interface. Predominantly net energy gains occurred along the reach during daylight hours, and heat exchange across the bed-water column interface accounted for <1% of the net energy budget. For periods when daytime net radiation gains were high (under clear skies), differences between water temperature observations decreased in the streamwise direction; a maximum difference of 2.5 °C was observed between the upstream reach boundary and 1050 m downstream. Furthermore, daily maximum water temperature at 1050 m downstream was ≤1°C cooler than at the upstream reach boundary and lagged the occurrence of daily maximum water temperature

  6. Species-specific intrinsic water use efficiency and its mediation of carbon assimilation during the drought

    NASA Astrophysics Data System (ADS)

    Yi, K.; Wenzel, M. K.; Maxwell, J. T.; Novick, K. A.; Gray, A.; Roman, D. T.

    2015-12-01

    Drought is expected to occur more frequently and intensely in the future, and many studies have suggested frequent and intense droughts can significantly alter carbon and water cycling in forest ecosystems, consequently decreasing the ability of forests to assimilate carbon. Predicting the impact of drought on forest ecosystem processes requires an understanding of species-specific responses to drought, especially in eastern US where species composition is highly dynamic. An emerging approach for describing species-specific drought response is to classify the plant water use strategy into isohydric and anisohydric behaviors. Trees utilizing isohydric behavior regulate water potential by closing stomata to reduce water loss during drought conditions, while anisohydric trees allow water potential to drop by sustaining stomatal conductance, but with the risk of hydraulic failure caused by cavitation of xylem tissues. Since catastrophic cavitation occurs infrequently in the relatively wet eastern U.S., we hypothesize that 1) tree growth of isohydric trees will be more limited during the drought than the anisohydric trees due to decreased stomatal conductance, but 2) variation in intrinsic water use efficient (iWUE) during drought in isohydric trees will mediate the effects of drought on carbon assimilation. We will test these hypotheses by 1) analyzing tree-ring chronologies and dendrometer data on productivity, and 2) estimating intrinsic water use efficiency (iWUE) at multiple scales by analyzing gas exchange data for the leaf-level, inter-annual variability of d13C in tree stem cores for the tree-level, and eddy covariance technique for the stand-level. Our study site is the Morgan-Monroe State Forest (Indiana, USA). A 46 m flux tower has been continuously recording the carbon, water and energy fluxes, and tree diameter has been measured every 2 weeks using dendrometers, since 1998. Additional research, including gas exchange measurements performed during the

  7. Low-pressure water-cooled inductively coupled plasma torch

    DOEpatents

    Seliskar, C.J.; Warner, D.K.

    1984-02-16

    An inductively coupled plasma torch is provided which comprises an inner tube, including a sample injection port to which the sample to be tested is supplied and comprising an enlarged central portion in which the plasma flame is confined; an outer tube surrounding the inner tube and containing water therein for cooling the inner tube, the outer tube including a water inlet port to which water is supplied and a water outlet port spaced from the water inlet port and from which water is removed after flowing through the outer tube; and an rf induction coil for inducing the plasma in the gas passing into the tube through the sample injection port. The sample injection port comprises a capillary tube including a reduced diameter orifice, projecting into the lower end of the inner tube. The water inlet is located at the lower end of the outer tube and the rf heating coil is disposed around the outer tube above and adjacent to the water inlet.

  8. Low-pressure water-cooled inductively coupled plasma torch

    DOEpatents

    Seliskar, Carl J.; Warner, David K.

    1988-12-27

    An inductively coupled plasma torch is provided which comprises an inner tube, including a sample injection port to which the sample to be tested is supplied and comprising an enlarged central portion in which the plasma flame is confined; an outer tube surrounding the inner tube and containing water therein for cooling the inner tube, the outer tube including a water inlet port to which water is supplied and a water outlet port spaced from the water inlet port and from which water is removed after flowing through the outer tube; and an r.f. induction coil for inducing the plasma in the gas passing into the tube through the sample injection port. The sample injection port comprises a capillary tube including a reduced diameter orifice, projecting into the lower end of the inner tube. The water inlet is located at the lower end of the outer tube and the r.f. heating coil is disposed around the outer tube above and adjacent to the water inlet.

  9. Efficiencies of polychlorinated biphenyl assimilation from water and algal food by the blue mussel (Mytilus edulis)

    SciTech Connect

    Bjoerk, M.; Gilek, M.

    1999-04-01

    A novel method was used to estimate assimilation efficiencies (AEs) of dissolved and food associated PCBs (IUPAC 31, 49, and 153) by the Baltic Sea blue mussel (Mytilus edulis). Mussels were exposed to radiolabeled PCBs in a series of short-term toxicokinetic experiments at different algal food concentrations, both at apparent steady-state (ASS) and non-steady-state (NSS) conditions in respect to PCB partitioning between water and algae. The PCB AEs were calculated using a physiologically based bioaccumulation model where experimentally determined uptake and exposure rates at ASS and NSS conditions were combined into linear equation systems, which were solved for PCB AE from water and food. A positive relationship between PCB uptake and algae clearance by the mussels was observed for all three PCBs. The PCB AEs from both water and food increased with congener hydrophobicity (octanol/water partition coefficient [K{sub ow}]), but AEs decreased with increases in water pumping and filtration rate of the mussels, respectively. The average contribution of food-associated PCB to the total uptake also increased with K{sub ow} from approximately 30% for PCB 31 and PCB 49 to 50% for PCB 153, mainly as a consequence of increased sorption to the algal food.

  10. Cooling cows efficiently with sprinklers: Physiological responses to water spray.

    PubMed

    Chen, Jennifer M; Schütz, Karin E; Tucker, Cassandra B

    2015-10-01

    Dairies in the United States commonly cool cattle with sprinklers mounted over the feed bunk that intermittently spray the cows' backs. These systems use potable water-an increasingly scarce resource--but there is little experimental evidence about how much is needed to cool cows or about droplet size, which is thought to affect hair coat penetration. Our objectives were to determine how sprinkler flow rate and droplet size affect physiological measures of heat load in a hot, dry climate, and to evaluate cooling effectiveness against water use. The treatments were an unsprayed control and 6 soaker nozzles that delivered four 3-min spray applications of 0.4, 1.3, or ≥ 4.5 L/min (with 2 droplet sizes within each flow rate) and resulting in 30 to 47% of spray directly wetting each cow. Data were collected from high-producing lactating Holsteins (n = 19) tested individually in ambient conditions (air temperature = 31.2 ± 3.8°C, mean ± standard deviation). Cows were restrained in headlocks for 1h and received 1 treatment/d for 3d each, with order of exposure balanced in a crossover design. When cows were not sprayed, physiological measures of heat load increased during the 1-h treatment. All measures responded rapidly to spray: skin temperature decreased during the first water application, and respiration rate and body temperature did so before the second. Droplet size had no effect on cooling, but flow rate affected several measures. At the end of 1h, 0.4 L/min resulted in lower respiration rate and skin temperature on directly sprayed body parts relative to the control but not baseline values, and body temperature increased to 0.2°C above baseline. When 1.3 or ≥ 4.5 L/min was applied, respiration rate was lower than the control and decreased relative to baseline, and body temperature stayed below baseline for at least 30 min after treatment ended. The treatment that best balanced cooling effectiveness against water usage was 1.3 L/min: although ≥ 4.5 L

  11. Application of flow cytometry to monitor assimilable organic carbon (AOC) and microbial community changes in water.

    PubMed

    Elhadidy, Ahmed M; Van Dyke, Michele I; Peldszus, Sigrid; Huck, Peter M

    2016-11-01

    Flow cytometry is an efficient monitoring tool for rapid cell counting, and can be applied to research on water quality and treatment. In this study, a method that employs flow cytometry and a natural microbial inoculum to determine assimilable organic carbon (AOC) was adapted for use with challenging surface waters that have a high organic and particle content, and subsequently applied in a long term river water study. AOC method optimization showed that river water bacteria could pass through a 0.2μm membrane filter, and therefore membrane filtration combined with heat treatment was required for sample sterilization. Preparation of the natural river inoculum with an acceptable yield value could only be achieved when grown using the natural water source, since growth was limited on different types of inorganic minimal media and in natural spring water. The resulting flow cytometry AOC method was reliable and reproducible, and results were comparable to the standard plate count AOC method. Size exclusion chromatography showed that both high and low molecular weight organic matter fractions were utilized by the natural AOC inoculum. Flow cytometry was used to measure both AOC levels and total cell counts in a long term study to monitor the water quality of a river which was used as a drinking water source. The method could distinguish between high nucleic acid (HNA) and low nucleic acid (LNA) groups of bacteria, and HNA bacteria were found to respond faster than LNA bacteria to seasonal changes in nutrients and water temperature. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Multiresistant waterborne pathogens isolated from water reservoirs and cooling systems.

    PubMed

    Blasco, M D; Esteve, C; Alcaide, E

    2008-08-01

    To determine the incidence of multiple antibiotic-resistant strains of the emergent human pathogens Legionella pneumophila, Pseudomonas aeruginosa and mesophilic Aeromonas species among those isolated from water reservoirs and industrial cooling systems. Water from four natural water reservoirs and four industrial cooling towers was sampled for 1 year period. The total heterotrophs, mesophilic Aeromonas, Pseudomonas spp. and Legionella spp. counts were performed as recommended by standard procedures, and the sensitivity of the isolates to 27 antibiotics was tested. A total of 117 Aeromonas, 60 P. aeruginosa and 15 L. pneumophila strains were isolated and identified by means of biochemical tests and DNA probes. 46.4% of Aeromonas, and 100% of P. aeruginosa isolates presented multiple resistance. Legionella pneumophila strains were generally sensitive to the drugs used. Antibiotic-resistant pathogenic bacteria belonging to P. aeruginosa and mesophilic Aeromonas species are common in natural aquatic environments. Thus, the risk of waterborne diseases owing to domestic and industrial uses of freshwater should be re-examined from the increase of bacterial resistance point of view. These data confirm the emergence of bacteria resistant to antibiotics in aquatic environments.

  13. Connecting Satellite Observations with Water Cycle Variables Through Land Data Assimilation: Examples Using the NASA GEOS-5 LDAS

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.; Forman, Barton A.; Draper, Clara S.; Liu, Qing

    2013-01-01

    A land data assimilation system (LDAS) can merge satellite observations (or retrievals) of land surface hydrological conditions, including soil moisture, snow, and terrestrial water storage (TWS), into a numerical model of land surface processes. In theory, the output from such a system is superior to estimates based on the observations or the model alone, thereby enhancing our ability to understand, monitor, and predict key elements of the terrestrial water cycle. In practice, however, satellite observations do not correspond directly to the water cycle variables of interest. The present paper addresses various aspects of this seeming mismatch using examples drawn from recent research with the ensemble-based NASA GEOS-5 LDAS. These aspects include (1) the assimilation of coarse-scale observations into higher-resolution land surface models, (2) the partitioning of satellite observations (such as TWS retrievals) into their constituent water cycle components, (3) the forward modeling of microwave brightness temperatures over land for radiance-based soil moisture and snow assimilation, and (4) the selection of the most relevant types of observations for the analysis of a specific water cycle variable that is not observed (such as root zone soil moisture). The solution to these challenges involves the careful construction of an observation operator that maps from the land surface model variables of interest to the space of the assimilated observations.

  14. Water-cooled radiofrequency neuroablation for sacroiliac joint dysfunctional pain

    PubMed Central

    Biswas, Binay Kumar; Dey, Samarjit; Biswas, Saumya; Mohan, Varinder Kumar

    2016-01-01

    Sacroiliac (SI) joint dysfunction is a common source of chronic low-back pain. Recent evidences from different parts of the world suggest that cooled radiofrequency (RF) neuroablation of sacral nerves supplying SI joints has superior pain alleviating properties than available existing treatment options for SI joint dysfunctional pain. A 35-year-old male had intractable bilateral SI joint pain (numeric rating scale [NRS] – 9/10) with poor treatment response to intra-articular steroid therapy. Bilateral water cooled = RF was applied for neuroablation of nerves supplying both SI joints. Postprocedure pain intensity was 5/10 and after 7 days it was 2/10. On 18th-month follow-up, he is pain free except for mild pain (NRS 2/10) on occasional extreme twisting of the back. This case attempts to highlight that sacral neuroablation based on cooled RF technique can be a long lasting remedial option for chronic SI joint pain unresponsive to conventional treatment. PMID:28096589

  15. Water-cooled radiofrequency neuroablation for sacroiliac joint dysfunctional pain.

    PubMed

    Biswas, Binay Kumar; Dey, Samarjit; Biswas, Saumya; Mohan, Varinder Kumar

    2016-01-01

    Sacroiliac (SI) joint dysfunction is a common source of chronic low-back pain. Recent evidences from different parts of the world suggest that cooled radiofrequency (RF) neuroablation of sacral nerves supplying SI joints has superior pain alleviating properties than available existing treatment options for SI joint dysfunctional pain. A 35-year-old male had intractable bilateral SI joint pain (numeric rating scale [NRS] - 9/10) with poor treatment response to intra-articular steroid therapy. Bilateral water cooled = RF was applied for neuroablation of nerves supplying both SI joints. Postprocedure pain intensity was 5/10 and after 7 days it was 2/10. On 18(th)-month follow-up, he is pain free except for mild pain (NRS 2/10) on occasional extreme twisting of the back. This case attempts to highlight that sacral neuroablation based on cooled RF technique can be a long lasting remedial option for chronic SI joint pain unresponsive to conventional treatment.

  16. Cardiovascular response to apneic immersion in cool and warm water

    NASA Technical Reports Server (NTRS)

    Folinsbee, L.

    1974-01-01

    The influence of prior exposure to cool water and the influence of lung volume on the responses to breath holding were examined. The bradycardia and vasoconstriction that occur during breath-hold diving in man are apparently the resultant of stimuli from apnea, relative expansion of the thorax, lung volume, esophageal pressure, face immersion, and thermal receptor stimulation. It is concluded that the bradycardia and vasoconstriction associated with breath holding during body immersion are not attenuated by a preexisting bradycardia and vasoconstriction due to cold.

  17. Cardiovascular response to apneic immersion in cool and warm water

    NASA Technical Reports Server (NTRS)

    Folinsbee, L.

    1974-01-01

    The influence of prior exposure to cool water and the influence of lung volume on the responses to breath holding were examined. The bradycardia and vasoconstriction that occur during breath-hold diving in man are apparently the resultant of stimuli from apnea, relative expansion of the thorax, lung volume, esophageal pressure, face immersion, and thermal receptor stimulation. It is concluded that the bradycardia and vasoconstriction associated with breath holding during body immersion are not attenuated by a preexisting bradycardia and vasoconstriction due to cold.

  18. Pink-Beam, Highly-Accurate Compact Water Cooled Slits

    SciTech Connect

    Lyndaker, Aaron; Deyhim, Alex; Jayne, Richard; Waterman, Dave; Caletka, Dave; Steadman, Paul; Dhesi, Sarnjeet

    2007-01-19

    Advanced Design Consulting, Inc. (ADC) has designed accurate compact slits for applications where high precision is required. The system consists of vertical and horizontal slit mechanisms, a vacuum vessel which houses them, water cooling lines with vacuum guards connected to the individual blades, stepper motors with linear encoders, limit (home position) switches and electrical connections including internal wiring for a drain current measurement system. The total slit size is adjustable from 0 to 15 mm both vertically and horizontally. Each of the four blades are individually controlled and motorized. In this paper, a summary of the design and Finite Element Analysis of the system are presented.

  19. Outsourcing of cooling water services ... A challenge or an opportunity?

    SciTech Connect

    Thatte, D.V.

    1998-12-31

    There is a growing trend of outsourcing a number of services. Cooling water treatment and monitoring are no exception. Outsourcing means different things to different organizations. This paper deals with various types of outsourcing set-ups and their technical and economic impact on both suppliers and users. It highlights the multifarious challenges faced by the suppliers as well as the users. It suggests actions to be taken by both parties in order to make such arrangements a success. This is then substantiated by interesting case histories illustrating these points.

  20. Pilot-scale cooling tower to evaluate corrosion, scaling, and biofouling control strategies for cooling system makeup water.

    PubMed

    Chien, S H; Hsieh, M K; Li, H; Monnell, J; Dzombak, D; Vidic, R

    2012-02-01

    Pilot-scale cooling towers can be used to evaluate corrosion, scaling, and biofouling control strategies when using particular cooling system makeup water and particular operating conditions. To study the potential for using a number of different impaired waters as makeup water, a pilot-scale system capable of generating 27,000 kJ∕h heat load and maintaining recirculating water flow with a Reynolds number of 1.92 × 10(4) was designed to study these critical processes under conditions that are similar to full-scale systems. The pilot-scale cooling tower was equipped with an automatic makeup water control system, automatic blowdown control system, semi-automatic biocide feeding system, and corrosion, scaling, and biofouling monitoring systems. Observed operational data revealed that the major operating parameters, including temperature change (6.6 °C), cycles of concentration (N = 4.6), water flow velocity (0.66 m∕s), and air mass velocity (3660 kg∕h m(2)), were controlled quite well for an extended period of time (up to 2 months). Overall, the performance of the pilot-scale cooling towers using treated municipal wastewater was shown to be suitable to study critical processes (corrosion, scaling, biofouling) and evaluate cooling water management strategies for makeup waters of complex quality.

  1. Diabatic forcing and intialization with assimilation of cloud water and rainwater in a forecast model

    NASA Technical Reports Server (NTRS)

    Raymond, William H.; Olson, William S.; Callan, Geary

    1995-01-01

    In this study, diabatic forcing, and liquid water assimilation techniques are tested in a semi-implicit hydrostatic regional forecast model containing explicit representations of grid-scale cloud water and rainwater. Diabatic forcing, in conjunction with diabatic contributions in the initialization, is found to help the forecast retain the diabatic signal found in the liquid water or heating rate data, consequently reducing the spinup time associated with grid-scale precipitation processes. Both observational Special Sensor Microwave/Imager (SSM/I) and model-generated data are used. A physical retrieval method incorporating SSM/I radiance data is utilized to estimate the 3D distribution of precipitating storms. In the retrieval method the relationship between precipitation distributions and upwelling microwave radiances is parameterized, based upon cloud ensemble-radiative model simulations. Regression formulae relating vertically integrated liquid and ice-phase precipitation amounts to latent heating rates are also derived from the cloud ensemble simulations. Thus, retrieved SSM/I precipitation structures can be used in conjunction with the regression-formulas to infer the 3D distribution of latent heating rates. These heating rates are used directly in the forecast model to help initiate Tropical Storm Emily (21 September 1987). The 14-h forecast of Emily's development yields atmospheric precipitation water contents that compare favorably with coincident SSM/I estimates.

  2. Diabatic forcing and intialization with assimilation of cloud water and rainwater in a forecast model

    NASA Technical Reports Server (NTRS)

    Raymond, William H.; Olson, William S.; Callan, Geary

    1995-01-01

    In this study, diabatic forcing, and liquid water assimilation techniques are tested in a semi-implicit hydrostatic regional forecast model containing explicit representations of grid-scale cloud water and rainwater. Diabatic forcing, in conjunction with diabatic contributions in the initialization, is found to help the forecast retain the diabatic signal found in the liquid water or heating rate data, consequently reducing the spinup time associated with grid-scale precipitation processes. Both observational Special Sensor Microwave/Imager (SSM/I) and model-generated data are used. A physical retrieval method incorporating SSM/I radiance data is utilized to estimate the 3D distribution of precipitating storms. In the retrieval method the relationship between precipitation distributions and upwelling microwave radiances is parameterized, based upon cloud ensemble-radiative model simulations. Regression formulae relating vertically integrated liquid and ice-phase precipitation amounts to latent heating rates are also derived from the cloud ensemble simulations. Thus, retrieved SSM/I precipitation structures can be used in conjunction with the regression-formulas to infer the 3D distribution of latent heating rates. These heating rates are used directly in the forecast model to help initiate Tropical Storm Emily (21 September 1987). The 14-h forecast of Emily's development yields atmospheric precipitation water contents that compare favorably with coincident SSM/I estimates.

  3. Comprehensive cooling water study: Volume 2, Water quality, Savannah River Plant: Final report

    SciTech Connect

    Lower, M.W.

    1987-10-01

    The Comprehensive Cooling Water Study (CCWS) was initiated in 1983 to evaluate the environmental effects of the intake and release of cooling water on the structure and function of aquatic ecosystems at the Savannah River Plant. The initial report described the results from the first year of the study. This document is the final report and concludes the program. The report comprises eight volumes. The first is a summary of environmental effects. The other seven volumes address water quality, radionuclide and heavy metal transport, wetlands, aquatic ecology, Federally endangered species, ecology of Par Pond, and waterfowl. 60 figs., 70 tabs.

  4. Assimilable organic carbon (AOC) in soil water extracts using Vibrio Harveyi BB721 and its implication for microbial biomass

    USDA-ARS?s Scientific Manuscript database

    Assimilable organic carbon (AOC) is commonly used to measure the growth potential of microorganisms in water, but has not yet been investigated for measuring microbial growth potential in soils. In this study, a simple, rapid, and non-growth based assay to determine AOC in soil was developed using a...

  5. Seismic Design of ITER Component Cooling Water System-1 Piping

    NASA Astrophysics Data System (ADS)

    Singh, Aditya P.; Jadhav, Mahesh; Sharma, Lalit K.; Gupta, Dinesh K.; Patel, Nirav; Ranjan, Rakesh; Gohil, Guman; Patel, Hiren; Dangi, Jinendra; Kumar, Mohit; Kumar, A. G. A.

    2017-04-01

    The successful performance of ITER machine very much depends upon the effective removal of heat from the in-vessel components and other auxiliary systems during Tokamak operation. This objective will be accomplished by the design of an effective Cooling Water System (CWS). The optimized piping layout design is an important element in CWS design and is one of the major design challenges owing to the factors of large thermal expansion and seismic accelerations; considering safety, accessibility and maintainability aspects. An important sub-system of ITER CWS, Component Cooling Water System-1 (CCWS-1) has very large diameter of pipes up to DN1600 with many intersections to fulfill the process flow requirements of clients for heat removal. Pipe intersection is the weakest link in the layout due to high stress intensification factor. CCWS-1 piping up to secondary confinement isolation valves as well as in-between these isolation valves need to survive a Seismic Level-2 (SL-2) earthquake during the Tokamak operation period to ensure structural stability of the system in the Safe Shutdown Earthquake (SSE) event. This paper presents the design, qualification and optimization of layout of ITER CCWS-1 loop to withstand SSE event combined with sustained and thermal loads as per the load combinations defined by ITER and allowable limits as per ASME B31.3, This paper also highlights the Modal and Response Spectrum Analyses done to find out the natural frequency and system behavior during the seismic event.

  6. Water cooled metal optics for the Advanced Light Source

    SciTech Connect

    McKinney, W.R.; Irick, S.C.; Lunt, D.L.J.

    1991-10-28

    The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.

  7. Water cooled metal optics for the Advanced Light Source

    SciTech Connect

    McKinney, W.R.; Irick, S.C. ); Lunt, D.L.J. )

    1991-10-28

    The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.

  8. 40 CFR 463.10 - Applicability; description of the contact cooling and heating water subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... processes in the contact cooling and heating water subcategory to waters of the United States and the introduction of such pollutants into publicly owned treatment works. Processes in the contact cooling and heating water subcategory are processes where process water comes in contact with plastic materials or...

  9. Experimental study of the decrease in the temperature of an air/water-cooled turbine blade

    NASA Astrophysics Data System (ADS)

    Ryzhov, A. A.; Sereda, A. V.; Shaiakberov, V. F.; Iskakov, K. M.; Shatalov, Iu. S.

    Results of the full-scale testing of an air/water-cooled deflector-type turbine blade are reported. Data on the decrease in the temperature of the cooling air and of the blade are presented and compared with the calculated values. An analysis of the results indicates that the use of air/water cooling makes it possible to significantly reduce the temperature of the cooling air and of the blade with practically no increase in the engine weight and dimensions.

  10. Optimum hot water temperature for absorption solar cooling

    SciTech Connect

    Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R.; Zacarias, A.

    2009-10-15

    The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)

  11. Shade, water and mass: Passive cooling in Andalucia

    SciTech Connect

    Carrasco, V.; Reynolds, J.S.

    1996-10-01

    A thermally massive, ancient patio (courtyard) house in Bornos Spain was monitored for 25 days in summer 1995. Data for light, relative humidity and air temperature were recorded at the floor`s center in the 3-story deep patio. Temperatures were also recorded in one ground floor and one second floor room adjacent to the patio, and on the roof terrace. Victor Carrasco (the owner) kept a daily record of his actions of shading (with a toldo), of watering the patio`s absorbent floor, and of opening windows for night ventilation. The data show the effects of shading, watering and night ventilation. The cycles of temperature and relative humidity in the center of the patio floor reveal a pattern of thermal sailing where skillful manipulations of shading, evaporative cooling, radiation and night ventilation result in indoor comfort despite the highest outside temperatures of this century that occurred in late July 1995.

  12. Kinetic model for the chlorination of power plant cooling waters

    SciTech Connect

    Johnson, J.D.; Qualls, R.G.

    1983-01-01

    Concern over the environmental effects of chlorination has prompted efforts to minimize the amount of chlorine necessary to prevent fouling of power-plant condensers. Kinetic expressions are developed for the short-term reactions of chlorine consumption by organic substances in natural freshwater. These expressions were developed to use in a kinetic model to predict the free and total available chlorine discharged in cooling water. This model uses commonly available water-quality data. It assumes that most of the chlorine-consuming substances are: (1) NH/sub 3/, (2) chloramine-forming organic-N, and (3) humic substances. It uses the Morris-Wei model of chlorine-ammonia reactions. Chloramine formation from organic-N was represented by a model compound, glycylglycine.

  13. The effect of cool water ingestion on gastrointestinal pill temperature.

    PubMed

    Wilkinson, David M; Carter, James M; Richmond, Victoria L; Blacker, Sam D; Rayson, Mark P

    2008-03-01

    Telemetric gastrointestinal (GI) temperature pills are now commonly used to measure core body temperature and could minimize the risk of heat illness while maximizing operational effectiveness in workers subject to high levels of thermal strain. To quantify the effect of repeated cool water ingestion on the accuracy of GI pill temperature. Ten operational firefighters ingested a pill to measure GI temperature (T1int) before overnight sleep. Two hours following breakfast and 11.5 h after ingesting T1int, the firefighters ingested a second pill (T2int) before performing 8.5 h of intermittent activity (repetitive cycles of 30 min of seated rest followed by 30 min of general firefighter duties). During the first 2 min of each 30-min rest period, the firefighters consumed 250 mL of chilled water (5-8 degrees C). Water ingestion had a highly variable effect both within and between subjects in transiently (32 +/- 10 min) reducing the temperature of T2int in comparison with T1int. In general, this transient reduction in T2int became progressively smaller as time following ingestion increased. In some firefighters, the difference between T1int and T2int became negligible (+/- 0.1 degrees C) after 3 h, whereas in two others, large differences (peaking at 2.0 degrees C and 6.3 degrees C) were still observed when water was consumed 8 h after pill ingestion. These results show that a GI pill ingested immediately prior to physical activity cannot be used to measure core body temperature accurately in all individuals during the following 8 h when cool fluids are regularly ingested. This makes GI temperature measurement unsuitable for workers who respond to emergency deployments when regular fluid consumption is recommended operational practice.

  14. Effects of Assimilation Window Length and Radiatively Active Water Ice Clouds on Martian Thermal Tides and Martian Atmosphere Predictability

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Greybush, S. J.; Kalnay, E.; Hoffman, R. N.; Wilson, R.

    2013-12-01

    Martian therrnal tides are a particularly prominent feature that contribute much to the Martian atmospheric circulation and dust transport. To study the Mars diurnal features (or thermal tides), data assimilation based on the GFDL Mars Global Climate Model (MGCM) with the 4D-Local Ensemble Transform Kalman Filter (4D-LETKF) is used to perform a reanalysis of spacecraft temperature retrievals from the Thermal Emission Spectrometer (TES) and Mars Climate Sounder (MCS) instruments. Since the traditional 6-hr assimilation cycle induces spurious resonance in the Kelvin waves represented in both surface pressure and mid-level temperature, short assimilation window lengths (1-hour and 2-hour) are introduced in 4D-LETKF. In order to compare the performances of different assimilation window lengths, 10-sol forecasts based on the hour 00 and 12 reanalysis are evaluated and compared. The shorter windows show improved forecast root mean square difference with respect to observations, and not only remove the spurious resonance but also better compensate for the absence of radiatively active water ice clouds (RAC). The predictability of Martian atmosphere is also studied using multi-sol forecasts initiated from analyses employing different assimilation window lengths, and the effect of RAC on Martian atmospheric predictability is also discussed.

  15. Interactions between Cool Roofs and Urban Irrigation: Do Cooling Strategies Reduce Water Consumption in the San Francisco Bay Area?

    NASA Astrophysics Data System (ADS)

    Vahmani, P.; Jones, A. D.

    2016-12-01

    California has experienced progressive drought since 2012, with 2012-2014 constituting a nearly 10,000-year drought event, resulting in a suite of policies with the goal of reducing water consumption. At the same time, climate warming effects of accelerated urbanization along with projected global climate change raise an urgent need for sustainable mitigation and adaptation strategies to cool urban climates. In this study, for the first time, we assess the overarching benefits of cooling strategies on urban water consumption. We employ a satellite-supported regional climate-modeling framework over the San Francisco Bay Area to assess the effects of cool roofs on urban irrigation, a topic of increasing importance as it accounts for a significant fraction of urban water use particularly in arid and semi-arid regions. We use a suit of climatological simulations at high (1.5 km) spatial resolution, based on a Weather Research and Forecasting (WRF)-Urban Canopy Model (UCM) modeling framework, reinforced with remotely sensed observations of Green Vegetation Fraction (GVF), leaf area index (LAI), and albedo. Our analysis shows that widespread incorporation of cool roofs would result in a mean daytime cooling of about 0.7° C, which in turn results in roughly 4% reduction in irrigation water, largely due to decreases in surface evapotranspiration rates. We further investigate the critical interactions between cool roofs, wind, and sea-breeze patterns as well as fog formation, a dominant weather pattern in San Francisco Bay area.

  16. Effects of assimilable organic carbon and free chlorine on bacterial growth in drinking water.

    PubMed

    Liu, Xiaolu; Wang, Jingqi; Liu, Tingting; Kong, Weiwen; He, Xiaoqing; Jin, Yi; Zhang, Bolin

    2015-01-01

    Assimilable organic carbon (AOC) is one of the most important factors affecting the re-growth of microorganisms in drinking water. High AOC concentrations result in biological instability, but disinfection kills microbes to ensure the safety of drinking water. Free chlorine is an important oxidizing agent used during the disinfection process. Therefore, we explored the combined effects of AOC and free chlorine on bacterial growth in drinking water using flow cytometry (FCM). The initial AOC concentration was 168 μg.L(-1) in all water samples. Without free chlorine, the concentrations of intact bacteria increased but the level of AOC decreased. The addition of sodium hypochlorite caused an increase and fluctuation in AOC due to the oxidation of organic carbon. The concentrations of intact bacteria decreased from 1.1 × 10(5) cells.mL(-1) to 2.6 × 10(4) cells.mL(-1) at an initial free chlorine dose of 0.6 mg.L(-1) to 4.8 × 10(4) cells.mL(-1) at an initial free chlorine dose of 0.3 mg.L(-1) due to free chlorine originating from sodium hypochlorite. Additionally, free chlorine might be more obviously affected AOC concentrations than microbial growth did. These results suggested that AOC and free chlorine might have combined effects on microbial growth. In this study, our results showed concentrations determined by FCM were higher than those by HPC, which indicated that some E. coli detected by FCM might not be detected using HPC in drinking water. The level of free chlorine might restrain the consumption of AOC by inhibiting the growth of E. coli; on the other hand, chlorination might increase the level of AOC, thereby increase the potential for microbial growth in the drinking water network.

  17. Effects of Assimilable Organic Carbon and Free Chlorine on Bacterial Growth in Drinking Water

    PubMed Central

    Liu, Tingting; Kong, Weiwen; He, Xiaoqing; Jin, Yi; Zhang, Bolin

    2015-01-01

    Assimilable organic carbon (AOC) is one of the most important factors affecting the re-growth of microorganisms in drinking water. High AOC concentrations result in biological instability, but disinfection kills microbes to ensure the safety of drinking water. Free chlorine is an important oxidizing agent used during the disinfection process. Therefore, we explored the combined effects of AOC and free chlorine on bacterial growth in drinking water using flow cytometry (FCM). The initial AOC concentration was 168 μg.L-1 in all water samples. Without free chlorine, the concentrations of intact bacteria increased but the level of AOC decreased. The addition of sodium hypochlorite caused an increase and fluctuation in AOC due to the oxidation of organic carbon. The concentrations of intact bacteria decreased from 1.1×105 cells.mL-1 to 2.6×104 cells.mL-1 at an initial free chlorine dose of 0.6 mg.L-1 to 4.8×104 cells.mL-1 at an initial free chlorine dose of 0.3 mg.L-1 due to free chlorine originating from sodium hypochlorite. Additionally, free chlorine might be more obviously affected AOC concentrations than microbial growth did. These results suggested that AOC and free chlorine might have combined effects on microbial growth. In this study, our results showed concentrations determined by FCM were higher than those by HPC, which indicated that some E. coli detected by FCM might not be detected using HPC in drinking water. The level of free chlorine might restrain the consumption of AOC by inhibiting the growth of E. coli; on the other hand, chlorination might increase the level of AOC, thereby increase the potential for microbial growth in the drinking water network. PMID:26034988

  18. Assimilation, Distribution, and Root Exudation of C by Ponderosa Pine Seedlings under Induced Water Stress.

    PubMed

    Reid, C P

    1974-07-01

    The effect of specific levels of induced water stress on the root exudation of (14)C from 9-month-old and 12-month-old ponderosa pine (Pinus ponderosa Laws.) seedlings was examined. Polyethylene glycol (PEG-4000) was used to decrease root solution water potentials by 0, -1.9, -2.6, -5.5, -9.6 and -11.9 bars in either aerated 0.25X Hoagland's nutrient solution or aerated distilled water.Assimilation of (14)CO(2) by plants under stress and subsequent translocation of (14)C label to the roots were both inhibited by a decrease in substrate water potential. Six days after (14)CO(2) introduction essentially no (14)C was detected in the roots of plants maintained at solution potentials of -5.5 bars or below. In subsequent studies (14)CO(2) was introduced 4 days prior to induction of stress. This allowed sufficient time for distribution of (14)C label throughout the root system.Root exudation of (14)C-labeled sugars, amino acids, and organic acids from plants in nutrient solution showed an increase from 0 to -1.9 bars, a decline from -1.9 to about -5.5 bars, and then an increase again from -5.5 to -11.9 bars. As substrate potential decreased, sugars as a percentage of total exudate increased, organic acids decreased and amino acids showed a slight decrease. Marked changes in percentages occurred between 0 and -2.6 bars. The exudation of sugars, amino acids, and organic acids from plants in distilled water showed similar trends in response to water stress as those in nutrient solution, but the quantity of total (14)C exuded was greater.

  19. Ensemble kalman filtering to perform data assimilation with soil water content probes and pedotransfer functions in modeling water flow in variably saturated soils

    USDA-ARS?s Scientific Manuscript database

    Data from modern soil water contents probes can be used for data assimilation in soil water flow modeling, i.e. continual correction of the flow model performance based on observations. The ensemble Kalman filter appears to be an appropriate method for that. The method requires estimates of the unce...

  20. A water-cooled mirror system for synchrotron radiation

    SciTech Connect

    DiGennaro, R.; Gee, B.; Guigli, J.; Hogrefe, H.; Howells, M.; Rarback, H.

    1987-06-01

    This paper describes the design and performance of a directly-cooled soft x-ray mirror system which has been developed at Lawrence Berkeley Laboratory for synchrotron radiation beam lines in which mirror thermal distortion must be minimized for acceptable optical performance. Two similar mirror systems are being built: the first mirror has been installed and operated at the National Synchrotron Light Source on the X-17T mini-undulator beam line and will be moved to the permanent X-1 beam line when a new, more powerful undulator is installed there. The second system is being built for installation at the Stanford Synchrotron Radiation Laboratory on Beam Line VI, where the total absorbed power on the mirror may be as high as 2400 W with peak absorbed power density of 520 W/cm/sup 2/. Direct cooling by convection is achieved using internal water channels in a brazed, dispersion-strengthened copper and OFHC copper substrate with a polished electroless-nickel surface. A simple kinematic linkage and flexural pivot mounting provide for mirror positioning about two rotational axes that coincide with the optical surface. Surface figure metrology, optical configurations, and tolerancing are also discussed. 11 refs., 8 figs.

  1. A water-cooled mirror system for synchrotron radiation

    NASA Astrophysics Data System (ADS)

    DiGennaro, Richard; Gee, Bruce; Guigli, Jim; Hogrefe, Henning; Howells, Malcolm; Rarback, Harvey

    1988-04-01

    This paper describes the design and performance of a directly-cooled soft X-ray mirror system which has been developed at Lawrence Berkeley Laboratory for synchrotron radiation beam lines in which mirror thermal distortion must be minimized for acceptable optical performance . Two similar mirror systems are being built: the first mirror has been installed and operated at the National Synchrotron Light Source on the X-17T miniundulator beam line and will be moved to the permanent X-1 beam line when a new, more powerful undulator is installed there. The second system is being built for installation at the Stanford Synchrotron Radiation Laboratory on Beam Line VI, where the total absorbed power on the mirror may be as high as 2400 W with a peak absorbed power density of 520 W/cm 2. Direct cooling by convection is achieved using internal water channels in a brazed, dispersion-strengthened copper and OFHC copper substrate with a polished electroless-nickel surface. A simple kinematic linkage and flexural pivot mounting provide for mirror positioning about two rotational axes that coincide with the optical surface. Surface figure metrology, optical configurations, and tolerancing are also discussed. This work was supported by the Office of Basic Energy Sciences, U.S. Department of Energy, under contract #DE-AC03-76SF00098.

  2. Operational data assimilation for improving hydrologic, hydrodynamic, and water quality forecasting using open tools

    NASA Astrophysics Data System (ADS)

    Weerts, Albrecht; Kockx, Arno; Sumihar, Julius; Verlaan, Martin; Hummel, Stef; Kramer, Werner; de Klaermaker, Simone

    2014-05-01

    Data assimilation holds considerable potential for improving water quantity (hydrologic/ hydraulic) and water quality predictions. However, advances in hydrologic DA research have not been adequately or timely implemented in operational forecast systems to improve the skill of forecasts for better informed real-world decision making. In contrast to most operational weather (related) forecast centers operational hydrologic forecast centers often are unable to support & maintain or lack the required computing support to implement such intensive DA calculations. Moreover, it remains difficult to achieve coupling of models, data, DA techniques and exploitation of high performance computing solutions in the operational forecasting process. Several potential components of a future solution have been or are being developed, one of those being the open source project OpenDA (www.openda.org). The objective of this poster is to highlight the development of OpenDA for operational forecasting and its integration with Delft-FEWS that is being used by more than 40 operational forecast centres around the world. Several applications of OpenDA using open source (and available) model codes from various fields will be highlighted.

  3. Satellite Data Assimilation

    NASA Technical Reports Server (NTRS)

    Fukumori, Ichiro

    1999-01-01

    Satellite altimetry provides the only routine observation of a dynamic variable of the global ocean. For instance, measurements from the TOPEX/POSEIDON altimeter have provided dramatic basin-wide images of the space-time evolution of sea level associated with the 1997-98 El Nino event. The nature of large-scale ocean circulation is being studied that underlies such sea level changes measured by satellite altimetry. To first approximation, properties of large-scale (order 1000 km and larger) sea level variability is latitudinally dependent. An analysis using a general circulation model shows that sea level changes are largely due to wind-driven baroclinic (depth dependent) circulation in the tropics (within 20 degrees of the equator), but are primarily due to the expansion and contraction of near surface water in temperate latitudes (between 20 deg. and 40 deg.) forced by seasonal heating and cooling. In contrast, wind-driven barotropic (depth independent) circulation dominates sea level variability in high latitudes (40 deg. and higher) characterized by periods that are as short as a few days. The presence of such inhomogeneity and the significance of high-frequency, large-scale sea level changes had not been fully recognized prior to this study, and are summarized in Fukumori et al. Numerical models provide theoretical relationships among properties that can be inverted using observations so as to estimate the entire state of the ocean, including properties that are otherwise difficult to measure remotely. The process is data assimilation. An approximate Kalman filter and smoother have been devised to assimilate three years of TOPEX/POSEIDON sea level data into a global ocean general circulation model. The figure below demonstrates the skill of the assimilation, and shows the altimeter assimilated estimate being in closer agreement than the simulation is with independent in situ measurements of subsur ace temperature and velocity, consistent with formal

  4. Thermal-hydraulic limitations on water-cooled limiters

    SciTech Connect

    Cha, Y.S.; Misra, B.

    1984-08-01

    An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on current design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, especially under asymmetrically heated conditions. Since the data presented herein concern primarily thermal protection, the final design should consider other factors such as thermal stresses, temperature limits, and fatigue.

  5. Detecting and mitigating aging in component cooling water systems

    SciTech Connect

    Lofaro, R.J.

    1991-01-01

    The time-dependent effects of aging on component cooling water (CCW) systems in nuclear power plants has been studied and documented as part of a research program sponsored by the US Nuclear Regulatory Commission. It was found that age related degradation leads to failures in the CCW system which can result in an increase in system unavailability, if not properly detected and mitigated. To identify effective methods of managing this degradation, information on inspection, monitoring, and maintenance practices currently available was obtained from various operating plants and reviewed. The findings were correlated with the most common aging mechanisms and failure modes and a compilation of aging detection and mitigation practices was formulated. This paper discusses the results of this work.

  6. Detecting and mitigating aging in component cooling water systems

    SciTech Connect

    Lofaro, R.J.

    1991-12-31

    The time-dependent effects of aging on component cooling water (CCW) systems in nuclear power plants has been studied and documented as part of a research program sponsored by the US Nuclear Regulatory Commission. It was found that age related degradation leads to failures in the CCW system which can result in an increase in system unavailability, if not properly detected and mitigated. To identify effective methods of managing this degradation, information on inspection, monitoring, and maintenance practices currently available was obtained from various operating plants and reviewed. The findings were correlated with the most common aging mechanisms and failure modes and a compilation of aging detection and mitigation practices was formulated. This paper discusses the results of this work.

  7. Flow-induced vibration of component cooling water heat exchangers

    SciTech Connect

    Yeh, Y.S.; Chen, S.S. . Nuclear Engineering Dept.; Argonne National Lab., IL )

    1990-01-01

    This paper presents an evaluation of flow-induced vibration problems of component cooling water heat exchangers in one of Taipower's nuclear power stations. Specifically, it describes flow-induced vibration phenomena, tests to identify the excitation mechanisms, measurement of response characteristics, analyses to predict tube response and wear, various design alterations, and modifications of the original design. Several unique features associated with the heat exchangers are demonstrated, including energy-trapping modes, existence of tube-support-plate (TSP)-inactive modes, and fluidelastic instability of TSP-active and -inactive modes. On the basis of this evaluation, the difficulties and future research needs for the evaluation of heat exchangers are identified. 11 refs., 19 figs., 3 tabs.

  8. Decrease in body insulation with exercise in cool water.

    PubMed

    Park, Y S; Pendergast, D R; Rennie, D W

    1984-06-01

    Steady-state body insulation was measured in 7 healthy male subjects during rest and exercise for 3 h in water of 28 degrees C - 32 degrees C. At rest, maximal body insulation increased as a linear function of mean subcutaneous fat thickness by an amount approximately 4-fold what would be predicted from the physical insulation of fat alone. With arm plus leg exercise, body insulation declined as an exponential function of the exercise intensity, reaching approximately 25% of the resting value at work loads above VO2 = 1.2 liters.min-1. During exercise the relationship between overall body insulation and mean subcutaneous fat thickness was almost identical to that predicted from fat insulation and mean subcutaneous fat thickness was almost identical to that predicted from fat insulation alone. These results suggest that 75% of maximal body insulation in resting subjects is achieved by use of skeletal muscle as an insulative barrier and that the muscle component is increased with increasing fat thickness. This muscle insulation shell is lost during exercise. As a practical consequence, heat generated by muscular exercise in water colder than critical water temperature cannot offset cooling unless the exercise intensity is great.

  9. A Comparative Analysis of Three Water Treatment Programs for Cooling Tower Systems

    DTIC Science & Technology

    1991-09-01

    10 to 20 percent per month. Use: 89 Treatment of cooling water in smaller cooling towers. Federal Specifications: None. SODIUM HEXAMETAPHOSPHATE ...viscosity 200-1000 cps at 25 degrees C. Use: Dispersant in cooling tower to prevent fouling by nonliving matter. Federal Specification: None. SODIUM ...Legionnaires’ disease in cooling towers. Federal Specification: O-S-602. SODIUM SILICATE,relatively low alkalinity, 41 degree Baume, approximately 28.8

  10. Water cooling system for an air-breathing hypersonic test vehicle

    NASA Technical Reports Server (NTRS)

    Petley, Dennis H.; Dziedzic, William M.

    1993-01-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  11. Water cooling system for an air-breathing hypersonic test vehicle

    NASA Technical Reports Server (NTRS)

    Petley, Dennis H.; Dziedzic, William M.

    1993-01-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  12. A land data assimilation system for sub-Saharan Africa food and water security applications

    NASA Astrophysics Data System (ADS)

    McNally, Amy; Arsenault, Kristi; Kumar, Sujay; Shukla, Shraddhanand; Peterson, Pete; Wang, Shugong; Funk, Chris; Peters-Lidard, Christa D.; Verdin, James P.

    2017-02-01

    Seasonal agricultural drought monitoring systems, which rely on satellite remote sensing and land surface models (LSMs), are important for disaster risk reduction and famine early warning. These systems require the best available weather inputs, as well as a long-term historical record to contextualize current observations. This article introduces the Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS), a custom instance of the NASA Land Information System (LIS) framework. The FLDAS is routinely used to produce multi-model and multi-forcing estimates of hydro-climate states and fluxes over semi-arid, food insecure regions of Africa. These modeled data and derived products, like soil moisture percentiles and water availability, were designed and are currently used to complement FEWS NET's operational remotely sensed rainfall, evapotranspiration, and vegetation observations. The 30+ years of monthly outputs from the FLDAS simulations are publicly available from the NASA Goddard Earth Science Data and Information Services Center (GES DISC) and recommended for use in hydroclimate studies, early warning applications, and by agro-meteorological scientists in Eastern, Southern, and Western Africa.

  13. Estimating Soil Water Retention Parameters Using Remote Sensing Platforms and Data Assimilation Tools

    NASA Astrophysics Data System (ADS)

    Mohanty, B. P.; Shin, Y.; Ines, A.

    2011-12-01

    Using air and space-borne remote sensing soil moisture data, insitu profile soil moisture at discrete depths, a physics-based soil hydrology model, and Genetic Algorithm (GA) we have developed (1) near-surface and (2) layer-specific soil-moisture assimilation schemes. This study quantifies the soil hydraulic properties of the near surface (0-5 cm) and root zone (0-200 cm) in a homogeneous/layered soil column (for individual layers) under various scenarios of vegetation type, bottom boundary conditions, and soil layering. We have conducted numerical (synthetic) studies and field experimental validation using simulation-optimization with genetic algorithm (SWAP-GA). In this study, it is demonstrated that soil texture, bottom boundary conditions, soil layers and heterogeneity of various soil types and vertical arrangements influence uncertainties for quantifying the soil hydraulic parameters in the layered soil domain. We envisage that our findings will help in the estimations of effective soil hydraulic parameters at large (remote sensing) footprints for land surface models under soil layering, vertical heterogeneity sequence, different vegetation and land covers, and ground water table depths.

  14. Carbon Assimilation and Leaf Water Status in Sugar Beet Leaves during a Simulated Natural Light Regimen.

    PubMed

    Geiger, D R; Shieh, W J; Lu, L S; Servaites, J C

    1991-11-01

    Carbon assimilation and leaf water status were studied in sugar beet (Beta vulgaris L., Klein E-type multigerm) leaves during a light period in which illumination either increased rapidly to full irradiance or changed gradually in a sinusoidal manner as generally occurs during a natural day. A light regimen that simulated the light of a natural day was produced by adjusting irradiance with a neutral-density filter under the control of a computer. Under this light regimen, photosynthesis, transpiration, and stomatal conductance followed the irradiance pattern very closely and ribulose bisphosphate carboxylase was nearly fully activated. When illumination was increased rapidly at the beginning of a light period, transpiration also increased quickly, causing leaves to wilt to some extent. The activation state of ribulose bisphosphate carboxylase increased to only 52%, but ribulose bisphosphate level was nearly twice as high as during the simulated natural day. In spite of the differences in activation state and ribulose bisphosphate levels, photosynthesis rates were very similar under both regimens. Nevertheless, differences in parameters between leaves under the two irradiance regimens can affect how a plant responds to internal or external factors, and therefore, the rate at which irradiance increases at the beginning of a light period is an important consideration when interpreting data.

  15. A land data assimilation system for sub-Saharan Africa food and water security applications.

    PubMed

    McNally, Amy; Arsenault, Kristi; Kumar, Sujay; Shukla, Shraddhanand; Peterson, Pete; Wang, Shugong; Funk, Chris; Peters-Lidard, Christa D; Verdin, James P

    2017-02-14

    Seasonal agricultural drought monitoring systems, which rely on satellite remote sensing and land surface models (LSMs), are important for disaster risk reduction and famine early warning. These systems require the best available weather inputs, as well as a long-term historical record to contextualize current observations. This article introduces the Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS), a custom instance of the NASA Land Information System (LIS) framework. The FLDAS is routinely used to produce multi-model and multi-forcing estimates of hydro-climate states and fluxes over semi-arid, food insecure regions of Africa. These modeled data and derived products, like soil moisture percentiles and water availability, were designed and are currently used to complement FEWS NET's operational remotely sensed rainfall, evapotranspiration, and vegetation observations. The 30+ years of monthly outputs from the FLDAS simulations are publicly available from the NASA Goddard Earth Science Data and Information Services Center (GES DISC) and recommended for use in hydroclimate studies, early warning applications, and by agro-meteorological scientists in Eastern, Southern, and Western Africa.

  16. Climate reconstruction using data assimilation of water isotope ratios from ice cores

    NASA Astrophysics Data System (ADS)

    Steiger, Nathan J.; Steig, Eric J.; Dee, Sylvia G.; Roe, Gerard H.; Hakim, Gregory J.

    2017-02-01

    Water isotope data from ice cores, particularly δ18O, have long been used in paleoclimatology. Although δ18O has been primarily interpreted as a proxy for local air temperature, isotope-enabled climate models have established that there are many nonlocal and nontemperature-related climatic influences on isotopic signals at coring locations. Moreover, recent observational studies have linked ice core isotopes to nonlocal patterns of climate variability, particularly to midlatitude atmospheric circulation patterns and to variations in tropical climate. Therefore, paleoclimate reconstructions may better utilize ice core isotope proxies by combining them with isotope-enabled climate models. Here we employ a data assimilation-based technique that fuses isotopic proxy information with the dynamical constraints of climate models. Through several idealized and real proxy experiments we assess the spatial and temporal extent to which isotope records can reconstruct surface temperature, 500 hPa geopotential height, and precipitation. We find local reconstruction skill to be most robust across the reconstructions, particularly for temperature and geopotential height, as well as limited nonlocal skill in the tropics. These results are in agreement with long-held views that isotopes in ice cores have clear value as local climate proxies, particularly for temperature and atmospheric circulation. These results also show that in principle nonlocal climate information may also be inferred from ice cores. However, the spatial range of this information is nonuniform and depends on skillful modeling of the proxy data within the reconstruction process.

  17. A land data assimilation system for sub-Saharan Africa food and water security applications

    PubMed Central

    McNally, Amy; Arsenault, Kristi; Kumar, Sujay; Shukla, Shraddhanand; Peterson, Pete; Wang, Shugong; Funk, Chris; Peters-Lidard, Christa D.; Verdin, James P.

    2017-01-01

    Seasonal agricultural drought monitoring systems, which rely on satellite remote sensing and land surface models (LSMs), are important for disaster risk reduction and famine early warning. These systems require the best available weather inputs, as well as a long-term historical record to contextualize current observations. This article introduces the Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS), a custom instance of the NASA Land Information System (LIS) framework. The FLDAS is routinely used to produce multi-model and multi-forcing estimates of hydro-climate states and fluxes over semi-arid, food insecure regions of Africa. These modeled data and derived products, like soil moisture percentiles and water availability, were designed and are currently used to complement FEWS NET’s operational remotely sensed rainfall, evapotranspiration, and vegetation observations. The 30+ years of monthly outputs from the FLDAS simulations are publicly available from the NASA Goddard Earth Science Data and Information Services Center (GES DISC) and recommended for use in hydroclimate studies, early warning applications, and by agro-meteorological scientists in Eastern, Southern, and Western Africa. PMID:28195575

  18. Remotely sensed data assimilation technique to develop machine learning models for use in water management

    NASA Astrophysics Data System (ADS)

    Zaman, Bushra

    Increasing population and water conflicts are making water management one of the most important issues of the present world. It has become absolutely necessary to find ways to manage water more efficiently. Technological advancement has introduced various techniques for data acquisition and analysis, and these tools can be used to address some of the critical issues that challenge water resource management. This research used learning machine techniques and information acquired through remote sensing, to solve problems related to soil moisture estimation and crop identification on large spatial scales. In this dissertation, solutions were proposed in three problem areas that can be important in the decision making process related to water management in irrigated systems. A data assimilation technique was used to build a learning machine model that generated soil moisture estimates commensurate with the scale of the data. The research was taken further by developing a multivariate machine learning algorithm to predict root zone soil moisture both in space and time. Further, a model was developed for supervised classification of multi-spectral reflectance data using a multi-class machine learning algorithm. The procedure was designed for classifying crops but the model is data dependent and can be used with other datasets and hence can be applied to other landcover classification problems. The dissertation compared the performance of relevance vector and the support vector machines in estimating soil moisture. A multivariate relevance vector machine algorithm was tested in the spatio-temporal prediction of soil moisture, and the multi-class relevance vector machine model was used for classifying different crop types. It was concluded that the classification scheme may uncover important data patterns contributing greatly to knowledge bases, and to scientific and medical research. The results for the soil moisture models would give a rough idea to farmers

  19. Estimating root zone soil water content using limited soils information and surface soil moisture data assimilation

    NASA Astrophysics Data System (ADS)

    Heathman, Gary Claude

    2001-10-01

    production. This work demonstrates the applicability of using limited soil data information, in combination with sequential assimilation of surface soil moisture, to adequately model soil water dynamics in the root zone. The results of this research contribute to a better understanding of how the spatial and temporal patterns of surface soil moisture are related to the physical and hydraulic properties of soils. The advantages, limitations, and potential impact of the overall approach are discussed. The Southern Great Plains 1997 (SGP97) Hydrology Experimental data sets, in conjunction with site-specific field data from the Little Washita River Watershed (LWRW) in south central Oklahoma serve as the data base for this project.

  20. Water spray cooling during handling of feedlot cattle

    NASA Astrophysics Data System (ADS)

    Brown-Brandl, Tami M.; Eigenberg, Roger A.; Nienaber, John A.

    2010-11-01

    Activities involved in receiving or working (e.g., sorting, dehorning, castration, weighing, implanting, etc.) of feedlot cattle cause an increase in body temperature. During hot weather the increased body temperature may disrupt normal behaviors including eating, which can be especially detrimental to the well-being and performance of the animals. Sprinkle cooling of animals has been successfully employed within the pen; however, added moisture to the pens' surface increases odor generation from the pen. A study was conducted to investigate the effectiveness of a single instance of wetting an animal within the working facility instead of in the pen, which could potentially provide extra evaporative cooling to offset the added heat produced by activity. Sixty-four cross-bred heifers were assigned to one of eight pens on the basis of weight. On four separate occasions during hot conditions (average temperature 28.2 ± 1.9°C, 29.1 ± 2.0°C, 28.9 ± 3.0°C, and 26.8 ± 1.6°C; with the temperature ranging from 22.6 to 32.5°C during the trials), the heifers were moved from their pens to and from the working facility (a building with a scale and squeeze chute located 160-200 m away). While in the squeeze chute, four of the pens of heifers were sprinkle cooled and the remaining four pens were worked as normal. The heifers that were treated had a body temperature that peaked sooner (31.9 ± 0.63 min compared to 37.6 ± 0.62) with a lower peak body temperature (39.55 ± 0.03°C compared to 39.74 ± 0.03°C), and recovered sooner (70.5 ± 2.4 min compared to 83.2 ± 2.4 min). The treated animals also had a lower panting score, a visual assessment of level of cattle heat stress (1.1 ± 0.2 compared to 1.16 ± 0.2). The behavior measurements that were taken did not indicate a change in behavior. It was concluded that while a single instance of wetting an animal within the working facility did not completely offset the increase in body temperature, it was beneficial to the

  1. Distinct difference of flaA genotypes of Legionella pneumophila between isolates from bath water and cooling tower water.

    PubMed

    Amemura-Maekawa, Junko; Kura, Fumiaki; Chang, Bin; Suzuki-Hashimoto, Atsuko; Ichinose, Masayuki; Endo, Takuro; Watanabe, Haruo

    2008-09-01

    To investigate the genetic difference of Legionella pneumophila in human-made environments, we collected isolates of L. pneumophila from bath water (n = 167) and cooling tower water (n = 128) primarily in the Kanto region in 2001 and 2005. The environmental isolates were serogrouped and sequenced for a target region of flaA. A total of 14 types of flaA genotypes were found: 10 from cooling tower water and nine from bath water. The flaA genotypes of isolates from cooling tower water were quite different from those of bath water.

  2. Marginal costs of water savings from cooling system retrofits: a case study for Texas power plants

    NASA Astrophysics Data System (ADS)

    Loew, Aviva; Jaramillo, Paulina; Zhai, Haibo

    2016-10-01

    The water demands of power plant cooling systems may strain water supply and make power generation vulnerable to water scarcity. Cooling systems range in their rates of water use, capital investment, and annual costs. Using Texas as a case study, we examined the cost of retrofitting existing coal and natural gas combined-cycle (NGCC) power plants with alternative cooling systems, either wet recirculating towers or air-cooled condensers for dry cooling. We applied a power plant assessment tool to model existing power plants in terms of their key plant attributes and site-specific meteorological conditions and then estimated operation characteristics of retrofitted plants and retrofit costs. We determined the anticipated annual reductions in water withdrawals and the cost-per-gallon of water saved by retrofits in both deterministic and probabilistic forms. The results demonstrate that replacing once-through cooling at coal-fired power plants with wet recirculating towers has the lowest cost per reduced water withdrawals, on average. The average marginal cost of water withdrawal savings for dry-cooling retrofits at coal-fired plants is approximately 0.68 cents per gallon, while the marginal recirculating retrofit cost is 0.008 cents per gallon. For NGCC plants, the average marginal costs of water withdrawal savings for dry-cooling and recirculating towers are 1.78 and 0.037 cents per gallon, respectively.

  3. [Isolation of Legionella spp. from cooling tower water and the effect of microbicides].

    PubMed

    Kasai, J; Ando, F; Kuwashima, M

    1989-08-01

    Legionella spp., the causative organism of legionnaires' disease, were isolated from more than 80% of water samples in cooling towers before washing. Therefore, we evaluated the effect of microbicide treatment of cooling tower water on Legionella spp., other bacteria and protozoa. 2-Bromo-2-nitropane-1,3-dial, 2,4-dibromo-5,5-dimethylhydantoin or silver nitrate-treated silica gel was added to cooling tower water. The isolation rate of Legionella spp. in the cooling tower water was 50% after microbiocide treatment with 2-bromo-2-nitropane-1,3-dial being the most effective. The microbicide treatment had no effect on other bacteria or protozoa. These findings indicated the importance of regular washing and water exchange of cooling tower water with microbicide treatment.

  4. Data assimilation in optimizing and integrating soil and water quality water model predictions at different scales

    USDA-ARS?s Scientific Manuscript database

    Relevant data about subsurface water flow and solute transport at relatively large scales that are of interest to the public are inherently laborious and in most cases simply impossible to obtain. Upscaling in which fine-scale models and data are used to predict changes at the coarser scales is the...

  5. Simulation of cooling-water discharges from power plants.

    PubMed

    Wu, J; Buchak, E M; Edinger, J E; Kolluru, V S

    2001-01-01

    Accurate simulation of the temperature distribution in a cooling lake or reservoir is often required for feasibility studies of engineering options that increase the cooling capacity of the waterbody. A three-dimensional hydrodynamic and temperature model has been developed and applied to several cooling lakes in the south-eastern United States. In this paper, the details of the modeling system are presented, along with the application to the Flint Creek Lake.

  6. State waste discharge permit application for cooling water and condensate discharges

    SciTech Connect

    Haggard, R.D.

    1996-08-12

    The following presents the Categorical State Waste Discharge Permit (SWDP) Application for the Cooling Water and Condensate Discharges on the Hanford Site. This application is intended to cover existing cooling water and condensate discharges as well as similar future discharges meeting the criteria set forth in this document.

  7. Cooling of Water in a Flask: Convection Currents in a Fluid with a Density Maximum

    ERIC Educational Resources Information Center

    Velasco, S.; White, J. A.; Roman, F. L.

    2010-01-01

    The effect of density inversion on the convective flow of water in a spherical glass flask cooled with the help of an ice-water bath is shown. The experiment was carried out by temperature measurements (cooling curves) taken at three different heights along the vertical diameter of the flask. Flows inside the flask are visualized by seeding the…

  8. Cooling of Water in a Flask: Convection Currents in a Fluid with a Density Maximum

    ERIC Educational Resources Information Center

    Velasco, S.; White, J. A.; Roman, F. L.

    2010-01-01

    The effect of density inversion on the convective flow of water in a spherical glass flask cooled with the help of an ice-water bath is shown. The experiment was carried out by temperature measurements (cooling curves) taken at three different heights along the vertical diameter of the flask. Flows inside the flask are visualized by seeding the…

  9. 77 FR 73056 - Initial Test Programs for Water-Cooled Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-07

    ...The U.S. Nuclear Regulatory Commission (NRC) is issuing for public comment draft regulatory guide (DG), DG-1259, ``Initial Test Programs for Water-Cooled Nuclear Power Plants.'' This guide describes the general scope and depth that the staff of the NRC considers acceptable for Initial Test Programs (ITPs) for light water cooled nuclear power plants.

  10. 40 CFR 63.1086 - How must I monitor for leaks to cooling water?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CATEGORIES (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Monitoring Requirements for Heat Exchange Systems § 63.1086 How must I monitor for leaks to cooling water? You must monitor for leaks to cooling water by monitoring each heat...

  11. Assimilation of water and dietary ions by the gastrointestinal tract during digestion in seawater-acclimated rainbow trout.

    PubMed

    Bucking, Carol; Fitzpatrick, John L; Nadella, Sunita R; McGaw, Iain J; Wood, Chris M

    2011-07-01

    Recent studies focusing on the consequences of feeding for ion and water balance in freshwater fish have revealed the need for similar comparative studies in seawater fish. A detailed time course sampling of gastrointestinal (GI) tract contents following the ingestion of a single meal of a commercial diet revealed the assimilation of both water and dietary ions (Na(+), Cl(-), K(+), Ca(2+), Mg(2+)) along the GI tract of seawater-acclimated rainbow trout (Oncorhynchus mykiss) which had been fasted for 1 week. Consumption of the meal did not change the drinking rate. There was a large secretion of fluid into the anterior intestine and caecae (presumably bile and/or pancreatic secretions). As a result, net assimilation (63%) of the ingested water along the GI tract was lower than generally reported for fasted trout. Mg(2+) was neither secreted into nor absorbed from the GI tract on a net basis. Only K(+) (93% assimilated) and Ca(2+) (43% assimilated) were absorbed in amounts in excess of those provided by ingested seawater, suggesting that dietary sources of K(+) and Ca(2+) may be important to seawater teleosts. The oesophagus-stomach served as a major site of absorption for Na(+), Cl(-), K(+), Ca(2+), and Mg(2+), and the anterior intestine and caecae as a major site of net secretion for all of these ions, except Cl(-). Despite large absorptive fluxes of these ions, the ionic composition of the plasma was maintained during the digestion of the meal. The results of the present study were compared with previous work on freshwater-acclimated rainbow trout, highlighting some important differences, but also several similarities on the assimilation of water and ions along the gastrointestinal tract during digestion. This study highlights the complicated array of ion and water transport that occurs in the intestine during digestion while revealing the importance of dietary K(+) and Ca(2+) to seawater-acclimated rainbow trout. Additionally, this study reveals that digestion

  12. State waste discharge permit application: 400 Area secondary cooling water

    SciTech Connect

    Not Available

    1992-12-01

    This document constitutes the Washington Administrative Code 173-216 State Waste Discharge Permit Application that serves as interim compliance as required by the Consent Order DE 91NM-177, for the 400 Area Secondary Cooling Water stream. As part of the Hanford Federal Facility Agreement and Consent Order negotiations, the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173-216 (or 173-218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permitting Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered in to Consent Order DE 91NM-177. The Consent Order DE 91NM-177 requires a series of permitting activities for liquid effluent discharges.

  13. Methodology for predicting cooling water effects on fish

    SciTech Connect

    Cakiroglu, C.; Yurteri, C.

    1998-07-01

    The mathematical model presented here predicts the long-term effects of once-through cooling water systems on local fish populations. The fish life cycle model simulates different life stages of fish by using appropriate expressions representing growth and mortality rates. The heart of the developed modeling approach is the prediction of plant-caused reduction in total fish population by estimating recruitment to adult population with and without entrainment of ichthyoplankton and impingement of small fish. The model was applied to a local fish species, gilthead (Aparus aurata), for the case of a proposed power plant in the Aegean region of Turkey. The simulations indicate that entrainment and impingement may lead to a population reduction of about 2% to 8% in the long run. In many cases, an impact of this size can be considered rather unimportant. In the case of sensitive and ecologically values species facing extinction, however, necessary precautions should be taken to minimize or totally avoid such an impact.

  14. A novel nonoxidizing biocide for cooling water systems

    SciTech Connect

    Sweeny, P.G.; Himpler, F.J.

    1994-12-31

    Quaternary ammonium biocides are commonly used in cooling water systems to control organisms associated with microbiologically induced corrosion and microbial fouling. These compounds while being highly efficacious and low cost have, in general, high foaming tendencies which can limit their range of application. A new quaternary ammonium compound, decylisononyldimethylammonium chloride (DIDMAC), was developed to prevent foam problems while maintaining the advantages of standard quat treatments. Laboratory evaluations showed DIDMAC to produce significantly less foam than a standard alkyldimethylbenzylammonium chloride (ADBAC), approaching that of a polymeric quat. Bactericidal and algicidal evaluations showed DIDMAC to provide efficacy greater than the polymeric quat and similar to the ADBAC. Field evaluations confirmed the laboratory results showing DIDMAC to foam significantly less than the ADBAC and similar to the polymeric quat. In the field, DIDMAC bactericidal and algicidal efficacies were evaluated in combination with other nonoxidizing biocides. Optimized programs, consisting of weekly additions of 10--30 mg/l DIDMAC with semiweekly applications of 1.5 mg/l isothiazolone, exceeded the algicidal and matched the bactericidal performance of control thione/isothiazolone programs. The DIDMAC-containing programs, in addition to providing enhanced bactericidal and algicidal efficacy, reduced treatment costs by 27 to 43% compared to the control.

  15. Scheduling satellite imagery acquisition for sequential assimilation of water level observation into flood modelling

    NASA Astrophysics Data System (ADS)

    García-Pintado, Javier; Neal, Jeff C.; Mason, David C.; Dance, Sarah L.; Bates, Paul D.

    2013-04-01

    Satellite-based imagery has proved useful for obtaining information on water levels in flood events. Microwave frequencies are generally more useful for flood detection than visible-band sensors because of its all-weather day-night capability. Specifically, the future SWOT mission, with Ka-band interferometry, will be able to provide direct Water Level Observations (WLOs), and current and future Synthetic Aperture Radar (SAR) sensors can provide information of flood extent, which, when intersected with a Digital Elevation Model (DEM) of the floodplain, provides indirect WLOs. By either means, satellite-based WLOs can be assimilated into a hydrodynamic model to decrease forecast uncertainty and further to estimate river discharge into the flooded domain. Operational scenarios can even make a combined use of imagery from different uncoordinated missions to sequentially estimate river discharge. Thus, with an increasing number of operational satellites with WLO capability, information on the relationship between satellite first visit, revisit times, and forecast performance is required to optimise the operational scheduling of satellite imagery. By using an Ensemble Transform Kalman Filter (ETKF) and a synthetic analysis with the 2D hydrodynamic model LISFLOOD-FP based on a real flooding case affecting an urban area (summer 2007, Tewkesbury, Southwest UK), we evaluate the sensitivity of the forecast performance to visit parameters. As an example, we use different scenarios of revisit times and observational errors expected from the current COSMO-Skymed (CSK) constellation, with X-band SAR. We emulate a generic hydrologic-hydrodynamic modelling cascade by imposing a bias and spatiotemporal correlations to the inflow error ensemble into the hydrodynamic domain. First, in agreement with previous research, estimation and correction for this bias leads to a clear improvement in keeping the forecast on track. Second, imagery obtained early in the flood is shown to have a

  16. Assimilation of Geosat Altimetric Data in a Nonlinear Shallow-Water Model of the Indian Ocean by Adjoint Approach. Part II: Some Validation and Interpretation of the Assimilated Results. Part 2; Some Validation and Interpretation of the Assimilated Results

    NASA Technical Reports Server (NTRS)

    Greiner, Eric; Perigaud, Claire

    1996-01-01

    This paper examines the results of assimilating Geosat sea level variations relative to the November 1986-November 1988 mean reference, in a nonlinear reduced-gravity model of the Indian Ocean, Data have been assimilated during one year starting in November 1986 with the objective of optimizing the initial conditions and the yearly averaged reference surface. The thermocline slope simulated by the model with or without assimilation is validated by comparison with the signal, which can be derived from expandable bathythermograph measurements performed in the Indian Ocean at that time. The topography simulated with assimilation on November 1986 is in very good agreement with the hydrographic data. The slopes corresponding to the South Equatorial Current and to the South Equatorial Countercurrent are better reproduced with assimilation than without during the first nine months. The whole circulation of the cyclonic gyre south of the equator is then strongly intensified by assimilation. Another assimilation experiment is run over the following year starting in November 1987. The difference between the two yearly mean surfaces simulated with assimilation is in excellent agreement with Geosat. In the southeastern Indian Ocean, the correction to the yearly mean dynamic topography due to assimilation over the second year is negatively correlated to the one the year before. This correction is also in agreement with hydrographic data. It is likely that the signal corrected by assimilation is not only due to wind error, because simulations driven by various wind forcings present the same features over the two years. Model simulations run with a prescribed throughflow transport anomaly indicate that assimilation is rather correcting in the interior of the model domain for inadequate boundary conditions with the Pacific.

  17. Assimilation of Geosat Altimetric Data in a Nonlinear Shallow-Water Model of the Indian Ocean by Adjoint Approach. Part II: Some Validation and Interpretation of the Assimilated Results. Part 2; Some Validation and Interpretation of the Assimilated Results

    NASA Technical Reports Server (NTRS)

    Greiner, Eric; Perigaud, Claire

    1996-01-01

    This paper examines the results of assimilating Geosat sea level variations relative to the November 1986-November 1988 mean reference, in a nonlinear reduced-gravity model of the Indian Ocean, Data have been assimilated during one year starting in November 1986 with the objective of optimizing the initial conditions and the yearly averaged reference surface. The thermocline slope simulated by the model with or without assimilation is validated by comparison with the signal, which can be derived from expandable bathythermograph measurements performed in the Indian Ocean at that time. The topography simulated with assimilation on November 1986 is in very good agreement with the hydrographic data. The slopes corresponding to the South Equatorial Current and to the South Equatorial Countercurrent are better reproduced with assimilation than without during the first nine months. The whole circulation of the cyclonic gyre south of the equator is then strongly intensified by assimilation. Another assimilation experiment is run over the following year starting in November 1987. The difference between the two yearly mean surfaces simulated with assimilation is in excellent agreement with Geosat. In the southeastern Indian Ocean, the correction to the yearly mean dynamic topography due to assimilation over the second year is negatively correlated to the one the year before. This correction is also in agreement with hydrographic data. It is likely that the signal corrected by assimilation is not only due to wind error, because simulations driven by various wind forcings present the same features over the two years. Model simulations run with a prescribed throughflow transport anomaly indicate that assimilation is rather correcting in the interior of the model domain for inadequate boundary conditions with the Pacific.

  18. Evaluation of water vapour assimilation in the tropical upper troposphere and lower stratosphere by a chemical transport model

    NASA Astrophysics Data System (ADS)

    Payra, Swagata; Ricaud, Philippe; Abida, Rachid; El Amraoui, Laaziz; Attié, Jean-Luc; Rivière, Emmanuel; Carminati, Fabien; von Clarmann, Thomas

    2016-09-01

    The present analysis deals with one of the most debated aspects of the studies on the upper troposphere/lower stratosphere (UTLS), namely the budget of water vapour (H2O) at the tropical tropopause. Within the French project "Multiscale water budget in the upper troposphere and lower stratosphere in the TROpics" (TRO-pico), a global-scale analysis has been set up based on space-borne observations, models and assimilation techniques. The MOCAGE-VALENTINA assimilation tool has been used to assimilate the Aura Microwave Limb Sounder (MLS) version 3.3 H2O measurements within the 316-5 hPa range from August 2011 to March 2013 with an assimilation window of 1 h. Diagnostics based on observations minus analysis and forecast are developed to assess the quality of the assimilated H2O fields. Comparison with an independent source of H2O measurements in the UTLS based on the space-borne Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) observations and with meteorological ARPEGE analyses is also shown. Sensitivity studies of the analysed fields have been performed by (1) considering periods when no MLS measurements are available and (2) using H2O data from another MLS version (4.2). The studies have been performed within three different spaces in time and space coincidences with MLS (hereafter referred to as MLS space) and MIPAS (MIPAS space) observations and with the model (model space) outputs and at three different levels: 121 hPa (upper troposphere), 100 hPa (tropopause) and 68 hPa (lower stratosphere) in January and February 2012. In the MLS space, the analyses behave consistently with the MLS observations from the upper troposphere to the lower stratosphere. In the model space, the analyses are wetter than the reference atmosphere as represented by ARPEGE and MLS in the upper troposphere (121 hPa) and around the tropopause (100 hPa), but are consistent with MLS and MIPAS in the lower stratosphere (68 hPa). In the MIPAS space, the sensitivity and the

  19. A fast radiative transfer model for the assimilation of water vapor radiances from the Kalpana very high resolution radiometer

    NASA Astrophysics Data System (ADS)

    Singh, Randhir; Rayer, Peter; Saunders, Roger; Migliorini, Stefano; Brugge, Roger; O'Neill, Alan

    2009-04-01

    A fast radiative transfer model (RTM) to compute emitted infrared radiances for a very high resolution radiometer (VHRR), onboard the operational Indian geostationary satellite Kalpana has been developed and verified. This work is a step towards the assimilation of Kalpana water vapor (WV) radiances into numerical weather prediction models. The fast RTM uses a regression-based approach to parameterize channel-specific convolved level to space transmittances. A comparison between the fast RTM and the line-by-line RTM demonstrated that the fast RTM can simulate line-by-line radiances for the Kalpana WV channel to an accuracy better than the instrument noise, while offering more rapid radiance calculations. A comparison of clear sky radiances of the Kalpana WV channel with the ECMWF model first guess radiances is also presented, aiming to demonstrate the fast RTM performance with the real observations. In order to assimilate the radiances from Kalpana, a simple scheme for bias correction has been suggested.

  20. Design of Water-Drip Cooling Facilities for Heat Treatment of Mill Rollers

    NASA Astrophysics Data System (ADS)

    Yudin, Yu. V.; Maisuradze, M. V.; Anufriev, N. P.

    2013-07-01

    Water-drip cooling devices based on centrifugal jet atomizers are studied experimentally. Their main operating characteristics such as the irrigation density, the uniformity of the distribution of irrigation over the cooled surface, the dependence of the heat transfer factor on the surface temperature, etc. are determined. The effect of the design and production parameters of the quenching facilities on their operating characteristics and mode of cooling of large steel articles is considered for mill rollers as an example. The results of the tests are used to design cooling facilities and heat treatment processes for mill rollers with the use of water-drip quenching.

  1. Numerical study of coupled transfer of heat and mass between air and water inside a geothermal water cooling tower

    NASA Astrophysics Data System (ADS)

    Bassem, Mohamed Mehdi; Bourouni, Karim; Thameur Chaibi, Mohamed

    2006-11-01

    In the south of Tunisia, geothermal water is used to irrigate cultures. Since its temperature is very high (70 C), geothermal water is cooled by cooling towers. These towers are sized empirically and present many operating problems such as excessive energy consumption, big loss of vapour and low cooling efficiency. The aim of our work is modelling the coupled heat and mass transfer between air and water inside the cooling tower. The most important results obtained are that the evaporative potential is dominating the convective one in the cooling process. That's why the cooling is more efficient in summer than in hibernal period when humidity of ambient air reaches high values. In other hand, the negative convective phenomenon is illustrated. In fact, at the bottom of the tower, water temperature reaches the air one; the two fluids begin to cooling simultaneously. Air is cooled by convection and water by evaporation. We demonstrate also that there is no point in putting fans in working during cold weather. We studied also the effect of the variation of heat transfer coefficient on the efficiency of cooling.

  2. Water spray cooling during handling of feedlot cattle.

    PubMed

    Brown-Brandl, Tami M; Eigenberg, Roger A; Nienaber, John A

    2010-11-01

    Activities involved in receiving or working (e.g., sorting, dehorning, castration, weighing, implanting, etc.) of feedlot cattle cause an increase in body temperature. During hot weather the increased body temperature may disrupt normal behaviors including eating, which can be especially detrimental to the well-being and performance of the animals. Sprinkle cooling of animals has been successfully employed within the pen; however, added moisture to the pens' surface increases odor generation from the pen. A study was conducted to investigate the effectiveness of a single instance of wetting an animal within the working facility instead of in the pen, which could potentially provide extra evaporative cooling to offset the added heat produced by activity. Sixty-four cross-bred heifers were assigned to one of eight pens on the basis of weight. On four separate occasions during hot conditions (average temperature 28.2 ± 1.9°C, 29.1 ± 2.0°C, 28.9 ± 3.0°C, and 26.8 ± 1.6°C; with the temperature ranging from 22.6 to 32.5°C during the trials), the heifers were moved from their pens to and from the working facility (a building with a scale and squeeze chute located 160-200 m away). While in the squeeze chute, four of the pens of heifers were sprinkle cooled and the remaining four pens were worked as normal. The heifers that were treated had a body temperature that peaked sooner (31.9 ± 0.63 min compared to 37.6 ± 0.62) with a lower peak body temperature (39.55 ± 0.03°C compared to 39.74 ± 0.03°C), and recovered sooner (70.5 ± 2.4 min compared to 83.2 ± 2.4 min). The treated animals also had a lower panting score, a visual assessment of level of cattle heat stress (1.1 ± 0.2 compared to 1.16 ± 0.2). The behavior measurements that were taken did not indicate a change in behavior. It was concluded that while a single instance of wetting an animal within the working facility did not completely offset the

  3. Nitrogen (N) assimilation and regeneration in hypoxic water column of Jinhae Bay, South Korea

    NASA Astrophysics Data System (ADS)

    Park, S.; An, S.; Lee, J.; Park, S.; Kim, Y.; Ryu, J.; Choe, S.

    2015-12-01

    Nitrogen generally controls the phytoplankton productivity in marine environment and detailed information regarding N cycling is necessary to understand extreme ecological processes such as hypoxic condition. Generally, primary production was measured using oxygen evolution or stable 13C isotope tracer experiment and nitrogen assimilation rate were estimated assuming certain carbon to nitrogen ratio. The regeneration of N is also estimated from the respiration rates although direct measurement method was applied in some experiments. We measured both photosynthetic and respiration rate using carbon and oxygen based methods, and at the same time, independent experiments for nitrogen assimilation and regeneration process measurement were conducted using stable isotope tracers. The differences of N assimilation and regeneration results between each method were analyzed in the context of hypoxic condition development.

  4. COOLING WATER ISSUES AND OPPORTUNITIES AT U.S. NUCLEAR POWER PLANTS

    SciTech Connect

    Gary Vine

    2010-12-01

    This report has been prepared for the Department of Energy, Office of Nuclear Energy (DOE-NE), for the purpose of providing a status report on the challenges and opportunities facing the U.S. commercial nuclear energy industry in the area of plant cooling water supply. The report was prompted in part by recent Second Circuit and Supreme Court decisions regarding cooling water system designs at existing thermo-electric power generating facilities in the U.S. (primarily fossil and nuclear plants). At issue in the courts have been Environmental Protection Agency regulations that define what constitutes “Best Technology Available” for intake structures that withdraw cooling water that is used to transfer and reject heat from the plant’s steam turbine via cooling water systems, while minimizing environmental impacts on aquatic life in nearby water bodies used to supply that cooling water. The report was also prompted by a growing recognition that cooling water availability and societal use conflicts are emerging as strategic energy and environmental issues, and that research and development (R&D) solutions to emerging water shortage issues are needed. In particular, cooling water availability is an important consideration in siting decisions for new nuclear power plants, and is an under-acknowledged issue in evaluating the pros and cons of retrofitting cooling towers at existing nuclear plants. Because of the significant ongoing research on water issues already being performed by industry, the national laboratories and other entities, this report relies heavily on ongoing work. In particular, this report has relied on collaboration with the Electric Power Research Institute (EPRI), including its recent work in the area of EPA regulations governing intake structures in thermoelectric cooling water systems.

  5. Optimal Environmental Performance of Water-cooled Chiller System with All Variable Speed Configurations

    NASA Astrophysics Data System (ADS)

    Yu, Fu Wing; Chan, Kwok Tai

    This study investigates how the environmental performance of water-cooled chiller systems can be optimized by applying load-based speed control to all the system components. New chiller and cooling tower models were developed using a transient systems simulation program called TRNSYS 15 in order to assess the electricity and water consumption of a chiller plant operating for a building cooling load profile. The chiller model was calibrated using manufacturer's performance data and used to analyze the coefficient of performance when the design and control of chiller components are changed. The NTU-effectiveness approach was used for the cooling tower model to consider the heat transfer effectiveness at various air-to-water flow ratios and to identify the makeup water rate. Applying load-based speed control to the cooling tower fans and pumps could save an annual plant operating cost by around 15% relative to an equivalent system with constant speed configurations.

  6. Three African antelope species with varying water dependencies exhibit similar selective brain cooling.

    PubMed

    Strauss, W Maartin; Hetem, Robyn S; Mitchell, Duncan; Maloney, Shane K; Meyer, Leith C R; Fuller, Andrea

    2016-05-01

    The use of selective brain cooling, where warm arterial blood destined for the brain is cooled in the carotid rete via counter-current heat exchange when in close proximity to cooler venous blood, contributes to the conservation of body water. We simultaneously measured carotid blood and hypothalamic temperature in four gemsbok, five red hartebeest and six blue wildebeest to assess the extent to which these free-living animals, with varying water dependency, routinely rely on selective brain cooling. We investigated the hypothesis that innate differences in selective brain cooling exist in large, sympatric artiodactyls with varying water dependency. All three species used selective brain cooling, without any discernible differences in three selective brain cooling indices. GLMMs revealed no species differences in the threshold temperature for selective brain cooling (z = 0.79, P = 0.43), the magnitude (z = -0.51, P = 0.61), or the frequency of selective brain cooling use (z = -0.47, P = 0.64), after controlling for carotid blood temperature and black globe temperature. Comparison of anatomical attributes of the carotid retes of the three species revealed that the volume (F 2,9 = 5.54, P = 0.03) and height (F 2,9 = 5.43, P = 0.03) of the carotid rete, per kilogram body mass, were greater in the red hartebeest than in the blue wildebeest. Nevertheless, intraspecific variability in the magnitude, the frequency of use, and the threshold temperature for selective brain cooling exceeded any interspecific variability in the three indices of selective brain cooling. We conclude that the three species have similar underlying ability to make use of selective brain cooling in an environment with freely available water. It remains to be seen to what extent these three species would rely on selective brain cooling, as a water conservation mechanism, when challenged by aridity, a condition likely to become prevalent throughout much of southern Africa under future climate change

  7. Thermal design of lithium bromide-water solution vapor absorption cooling system for indirect evaporative cooling for IT pod

    NASA Astrophysics Data System (ADS)

    Sawant, Digvijay Ramkrishna

    Nowadays with increase use of internet, mobile there is increase in heat which ultimately increases the efficient cooling system of server room or IT POD. Use of traditional ways of cooling system has ultimately increased CO2 emission and depletion of CFC's are serious environmental issues which led scientific people to improve cooling techniques and eliminate use of CFC's. To reduce dependency on fossil fuels and 4environmental friendly system needed to be design. For being utilizing low grade energy source such as solar collector and reducing dependency on fossil fuel vapour absorption cooling system has shown a great driving force in today's refrigeration systems. This LiBr-water aabsorption cooling consists of five heat exchanger namely: Evaporator, Absorber, Solution Heat Exchanger, Generator, Condenser. The thermal design was done for a load of 23 kW and the procedure was described in the thesis. There are 120 servers in the IT POD emitting 196 W of heat each on full load and some of the heat was generated by the computer placed inside the IT POD. A detailed procedure has been discussed. A excel spreadsheet was to prepared with varying tube sizes to see the effect on flows and ultimately overall heat transfer coefficient.

  8. Rotation and penetrative convection in water cooled from below}

    NASA Astrophysics Data System (ADS)

    Alboussiere, T.; Labrosse, S.; Dubuffet, F.; Thibon, F.; Huguet, L.; Deguen, R.

    2012-12-01

    It has already been suggested that the outer core of the Earth might not be entirely in a convective regime [1], for instance in a region close to the CMB where the heat conducted along the adiabat could be larger than the net heat transfer and where compositional buoyancy vanishes. Radial dependence of thermal conductivity could also produce neighbouring stable and unstable regions. To what extent does convection spread into the stable region is then an important issue. Liquid water and its maximum density at 4°C provides a convenient way to observe penetrative convection. We have performed experiments where a volume of water (of square cross-section 16 cm by 16 cm and height 20 cm) initially at room temperature (around 22°C) is then suddenly cooled around 0°C at the bottom while the sides and top walls are (imperfectly) thermally insulated. Near the bottom, where temperature is below 4°C, unstable buoyancy conditions prevail and we observe convective cells. Above 4°C, quiescent stable stratification is observed. Temperature is close to 4°C within the bulk of the convective zone, so that the flux of heat extracted from the bottom is used to change the temperature from 22°C to 4°C within the successive layers of water, while the height of the convective zone increases and eventually reaches the top of the volume. Temperatures have been measured on a array of 15 PT100 probes protruding 5 mm into water along a vertical side wall. the extreme probes are 1 cm away from the lower and upper boundaries respectively. The evolution of all 15 temperatures can be seen on left-hand side of Fig. 1. Another type of information was obtained from a synthetic schlieren technique, whereby pictures of a random pattern placed behind the transparent water-filled box (perspex walls) are taken every 5 s with a digital camera. The cross-correlation of the different images provides a dynamical visualization of the gradients of refraction index within the volume of water. A snapshot

  9. Estimating Water and Heat Fluxes with a Four-dimensional Weak-constraint Variational Data Assimilation Approach

    NASA Astrophysics Data System (ADS)

    Bateni, S. M.; Xu, T.

    2015-12-01

    Accurate estimation of water and heat fluxes is required for irrigation scheduling, weather prediction, and water resources planning and management. A weak-constraint variational data assimilation (WC-VDA) scheme is developed to estimate water and heat fluxes by assimilating sequences of land surface temperature (LST) observations. The commonly used strong-constraint VDA systems adversely affect the accuracy of water and heat flux estimates as they assume the model is perfect. The WC-VDA approach accounts for structural and model errors and generates more accurate results via adding a model error term into the surface energy balance equation. The two key unknown parameters of the WC-VDA system (i.e., CHN, the bulk heat transfer coefficient and EF, evaporative fraction) and the model error term are optimized by minimizing the cost function. The WC-VDA model was tested at two sites with contrasting hydrological and vegetative conditions: the Daman site (a wet site located in an oasis area and covered by seeded corn) and the Huazhaizi site (a dry site located in a desert area and covered by sparse grass) in middle stream of Heihe river basin, northwest China. Compared to the strong-constraint VDA system, the WC-VDA method generates more accurate estimates of water and energy fluxes over the desert and oasis sites with dry and wet conditions.

  10. Radiant Cooling for Closed-Loop Water Containment: Exploration of Possible Application in Dry Docks

    DTIC Science & Technology

    2015-08-20

    Radiant Cooling For Closed-Loop Water Containment: Exploration of Possible Application in Dry Docks by Trevor R. Murphy, Mechanical...Organization: SPAWAR Sponsoring Organization: NESDI Keywords: Dry Dock Cooling , Heat Transfer, Closed Loop, Pipe System, Cost, Pareto List of Programs...provide data for estimating the cost of implementing a closed-loop radiant cooling system for ships in dry docks. Depending on the material used, pipe

  11. Cooling Rates of Humans in Air and in Water: An Experiment

    NASA Astrophysics Data System (ADS)

    Bohren, Craig F.

    2012-12-01

    In a previous article I analyzed in detail the physical factors resulting in greater cooling rates of objects in still water than in still air, emphasizing cooling of the human body. By cooling rate I mean the rate of decrease of core temperature uncompensated by metabolism. I concluded that the "correct ratio for humans is closer to 2 than to 10." To support this assertion I subsequently did experiments, which I report following a digression on hypothermia.

  12. Process for utilizing waste heat and for obtaining water gas during the cooling of incandescent coke

    SciTech Connect

    Jung, R.A.

    1984-03-20

    A process for utilizing waste heat and for obtaining water gas during the cooling of incandescent coke ejected from a chamber oven is described, this process being in two stages. In the first stage, the coke is dry-cooled with a mixture of water gas and water vapor as the cooling gas. This is circulated, and from the circuit the desired waste heat and the desired water gas are extracted. In the second stage, the coke is wet-cooled with water. The water vapor formed is taken off and returned to the environment and/or to the second stage. An apparatus is described for carrying out the process, and this apparatus has, located under one another, a filling shaft (1), a pre-chamber (2), a cooling chamber (3), a quenching chamber (4) with a water-spray device (5), an extraction housing (6) and a discharge shaft (7), and is equipped with a cooling-gas discharge line (19) leading away from the cooling chamber (3) and, in succession, a coarse separator (20), a heat sink (21), a blower (23), a cooling-gas delivery line (25) to the cooling chamber (3), an extraction line (26) leading away from the cooling-gas delivery line (25) with a throttling device (27), and a take-off line (34) which leads away from the extraction housing (6) and which leads to a cyclone separator (35), a blower (36) and an exhaust steam pipe (38) with a throttling device (37) and/or to a return line (39) with a throttling device (40).

  13. Multisensor snow data assimilation at the continental scale: The value of Gravity Recovery and Climate Experiment terrestrial water storage information

    NASA Astrophysics Data System (ADS)

    Su, Hua; Yang, Zong-Liang; Dickinson, Robert E.; Wilson, Clark R.; Niu, Guo-Yue

    2010-05-01

    This investigation establishes a multisensor snow data assimilation system over North America (from January 2002 to June 2007), toward the goal of better estimation of snowpack (in particular, snow water equivalent and snow depth) via incorporating both Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage (TWS) and Moderate Resolution Imaging Spectroradiometer (MODIS) snow cover fraction (SCF) information into the Community Land Model. The different properties associated with the SCF and TWS observations are accommodated through a unified approach using the ensemble Kalman filter and smoother. Results show that this multisensor approach can provide significant improvements over a MODIS-only approach, for example, in the Saint Lawrence, Fraser, Mackenzie, Churchill & Nelson, and Yukon river basins and the southwestern rim of Hudson Bay. At middle latitudes, for example, the North Central and Missouri river basins, the inclusion of GRACE information preserves the advantages (compared with the open loop) shown in the MODIS-only run. However, in some high-latitude areas and given months the open loop run shows a comparable or even better performance, implying considerable room for refinements of the multisensor algorithm. In addition, ensemble-based metrics are calculated and interpreted domainwide. They indicate the potential importance of accurate representation of snow water equivalent autocovariance in assimilating TWS observations and the regional and/or seasonal dependence of GRACE’s capability to reduce ensemble variance. These analyses contribute to clarifying the effects of GRACE’s special features (e.g., a vertical integral of different land water changes, coarse spatial and temporal resolution) in the snow data assimilation system.

  14. Accident analysis of heavy water cooled thorium breeder reactor

    SciTech Connect

    Yulianti, Yanti; Su’ud, Zaki; Takaki, Naoyuki

    2015-04-16

    Thorium has lately attracted considerable attention because it is accumulating as a by-product of large scale rare earth mining. The objective of research is to analyze transient behavior of a heavy water cooled thorium breeder that is designed by Tokai University and Tokyo Institute of Technology. That is oxide fueled, PWR type reactor with heavy water as primary coolant. An example of the optimized core has relatively small moderator to fuel volume ratio (MFR) of 0.6 and the characteristics of the core are burn-up of 67 GWd/t, breeding ratio of 1.08, burn-up reactivity loss during cycles of < 0.2% dk/k, and negative coolant reactivity coefficient. One of the nuclear reactor accidents types examined here is Unprotected Transient over Power (UTOP) due to withdrawing of the control rod that result in the positive reactivity insertion so that the reactor power will increase rapidly. Another accident type is Unprotected Loss of Flow (ULOF) that caused by failure of coolant pumps. To analyze the reactor accidents, neutron distribution calculation in the nuclear reactor is the most important factor. The best expression for the neutron distribution is the Boltzmann transport equation. However, solving this equation is very difficult so that the space-time diffusion equation is commonly used. Usually, space-time diffusion equation is solved by employing a point kinetics approach. However, this approach is less accurate for a spatially heterogeneous nuclear reactor and the nuclear reactor with quite large reactivity input. Direct method is therefore used to solve space-time diffusion equation which consider spatial factor in detail during nuclear reactor accident simulation. Set of equations that obtained from full implicit finite-difference method is solved by using iterative methods. The indication of UTOP accident is decreasing macroscopic absorption cross-section that results large external reactivity, and ULOF accident is indicated by decreasing coolant flow. The

  15. Accident analysis of heavy water cooled thorium breeder reactor

    NASA Astrophysics Data System (ADS)

    Yulianti, Yanti; Su'ud, Zaki; Takaki, Naoyuki

    2015-04-01

    Thorium has lately attracted considerable attention because it is accumulating as a by-product of large scale rare earth mining. The objective of research is to analyze transient behavior of a heavy water cooled thorium breeder that is designed by Tokai University and Tokyo Institute of Technology. That is oxide fueled, PWR type reactor with heavy water as primary coolant. An example of the optimized core has relatively small moderator to fuel volume ratio (MFR) of 0.6 and the characteristics of the core are burn-up of 67 GWd/t, breeding ratio of 1.08, burn-up reactivity loss during cycles of < 0.2% dk/k, and negative coolant reactivity coefficient. One of the nuclear reactor accidents types examined here is Unprotected Transient over Power (UTOP) due to withdrawing of the control rod that result in the positive reactivity insertion so that the reactor power will increase rapidly. Another accident type is Unprotected Loss of Flow (ULOF) that caused by failure of coolant pumps. To analyze the reactor accidents, neutron distribution calculation in the nuclear reactor is the most important factor. The best expression for the neutron distribution is the Boltzmann transport equation. However, solving this equation is very difficult so that the space-time diffusion equation is commonly used. Usually, space-time diffusion equation is solved by employing a point kinetics approach. However, this approach is less accurate for a spatially heterogeneous nuclear reactor and the nuclear reactor with quite large reactivity input. Direct method is therefore used to solve space-time diffusion equation which consider spatial factor in detail during nuclear reactor accident simulation. Set of equations that obtained from full implicit finite-difference method is solved by using iterative methods. The indication of UTOP accident is decreasing macroscopic absorption cross-section that results large external reactivity, and ULOF accident is indicated by decreasing coolant flow. The

  16. Sensitivity analysis of a data assimilation technique for hindcasting and forecasting hydrodynamics of a complex coastal water body

    NASA Astrophysics Data System (ADS)

    Ren, Lei; Hartnett, Michael

    2017-02-01

    Accurate forecasting of coastal surface currents is of great economic importance due to marine activities such as marine renewable energy and fish farms in coastal regions in recent twenty years. Advanced oceanographic observation systems such as satellites and radars can provide many parameters of interest, such as surface currents and waves, with fine spatial resolution in near real time. To enhance modelling capability, data assimilation (DA) techniques which combine the available measurements with the hydrodynamic models have been used since the 1990s in oceanography. Assimilating measurements into hydrodynamic models makes the original model background states follow the observation trajectory, then uses it to provide more accurate forecasting information. Galway Bay is an open, wind dominated water body on which two coastal radars are deployed. An efficient and easy to implement sequential DA algorithm named Optimal Interpolation (OI) was used to blend radar surface current data into a three-dimensional Environmental Fluid Dynamics Code (EFDC) model. Two empirical parameters, horizontal correlation length and DA cycle length (CL), are inherent within OI. No guidance has previously been published regarding selection of appropriate values of these parameters or how sensitive OI DA is to variations in their values. Detailed sensitivity analysis has been performed on both of these parameters and results presented. Appropriate value of DA CL was examined and determined on producing the minimum Root-Mean-Square-Error (RMSE) between radar data and model background states. Analysis was performed to evaluate assimilation index (AI) of using an OI DA algorithm in the model. AI of the half-day forecasting mean vectors' directions was over 50% in the best assimilation model. The ability of using OI to improve model forecasts was also assessed and is reported upon.

  17. Evaluation of water cooled supersonic temperature and pressure probes for application to 1366 K flows

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas; Seiner, John M.

    1990-01-01

    Water cooled supersonic probes are developed to investigate total pressure, static pressure, and total temperature in high-temperature jet plumes and thereby determine the mean flow properties. Two probe concepts, designed for operation at up to 1366 K in a Mach 2 flow, are tested on a water cooled nozzle. The two probe designs - the unsymmetric four-tube cooling configuration and the symmetric annular cooling design - take measurements at 755, 1089, and 1366 K of the three parameters. The cooled total and static pressure readings are found to agree with previous test results with uncooled configurations. The total-temperature probe, however, is affected by the introduction of water coolant, and effect which is explained by the increased heat transfer across the thermocouple-bead surface. Further investigation of the effect of coolant on the temperature probe is proposed to mitigate the effect and calculate more accurate temperatures in jet plumes.

  18. Evaluation of water cooled supersonic temperature and pressure probes for application to 1366 K flows

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas; Seiner, John M.

    1990-01-01

    Water cooled supersonic probes are developed to investigate total pressure, static pressure, and total temperature in high-temperature jet plumes and thereby determine the mean flow properties. Two probe concepts, designed for operation at up to 1366 K in a Mach 2 flow, are tested on a water cooled nozzle. The two probe designs - the unsymmetric four-tube cooling configuration and the symmetric annular cooling design - take measurements at 755, 1089, and 1366 K of the three parameters. The cooled total and static pressure readings are found to agree with previous test results with uncooled configurations. The total-temperature probe, however, is affected by the introduction of water coolant, and effect which is explained by the increased heat transfer across the thermocouple-bead surface. Further investigation of the effect of coolant on the temperature probe is proposed to mitigate the effect and calculate more accurate temperatures in jet plumes.

  19. Estimation of the residual bromine concentration after disinfection of cooling water by statistical evaluation.

    PubMed

    Megalopoulos, Fivos A; Ochsenkuehn-Petropoulou, Maria T

    2015-01-01

    A statistical model based on multiple linear regression is developed, to estimate the bromine residual that can be expected after the bromination of cooling water. Make-up water sampled from a power plant in the Greek territory was used for the creation of the various cooling water matrices under investigation. The amount of bromine fed to the circuit, as well as other important operational parameters such as concentration at the cooling tower, temperature, organic load and contact time are taken as the independent variables. It is found that the highest contribution to the model's predictive ability comes from cooling water's organic load concentration, followed by the amount of bromine fed to the circuit, the water's mean temperature, the duration of the bromination period and finally its conductivity. Comparison of the model results with the experimental data confirms its ability to predict residual bromine given specific bromination conditions.

  20. Comparison of solar panel cooling system by using dc brushless fan and dc water

    NASA Astrophysics Data System (ADS)

    Irwan, Y. M.; Leow, W. Z.; Irwanto, M.; M, Fareq; Hassan, S. I. S.; Safwati, I.; Amelia, A. R.

    2015-06-01

    The purpose of this article is to discuss comparison of solar panel cooling system by using DC brushless fan and DC water pump. Solar photovoltaic (PV) power generation is an interesting technique to reduce non-renewable energy consumption and as a renewable energy. The temperature of PV modules increases when it absorbs solar radiation, causing a decrease in efficiency. A solar cooling system is design, construct and experimentally researched within this work. To make an effort to cool the PV module, Direct Current (DC) brushless fan and DC water pump with inlet/outlet manifold are designed for constant air movement and water flow circulation at the back side and front side of PV module representatively. Temperature sensors were installed on the PV module to detect temperature of PV. PIC microcontroller was used to control the DC brushless fan and water pump for switch ON or OFF depend on the temperature of PV module automatically. The performance with and without cooling system are shown in this experiment. The PV module with DC water pump cooling system increase 3.52%, 36.27%, 38.98%in term of output voltage, output current, output power respectively. It decrease 6.36 °C compare than to PV module without DC water pump cooling system. While DC brushless fan cooling system increase 3.47%, 29.55%, 32.23%in term of output voltage, output current, and output power respectively. It decrease 6.1 °C compare than to PV module without DC brushless fan cooling system. The efficiency of PV module with cooling system was increasing compared to PV module without cooling system; this is because the ambient temperature dropped significantly. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer.

  1. Computer program calculates peripheral water injection cooling of axisymmetric subsonic diffuser

    NASA Technical Reports Server (NTRS)

    Grey, J.

    1968-01-01

    Digital computer program calculates the cooling effectiveness and flow characteristics resulting from the mixing of a cool liquid injectant /water/ with a hot sonic or subsonic gas stream /hydrogen/. The output of the program provides pressure, temperature, velocity, density, composition, and Mach number profiles at any location in the mixing duct.

  2. Global analyses of water vapor, cloud and precipitation derived from a diagnostic assimilation of SSM/I geophysical retrievals

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin R.; Cohen, Charles

    1990-01-01

    An analytical approach is described for diagnostically assimilating moisture data from Special Sensor Microwave Imager (SSM/I) into a global analysis of water vapor, cloud content, and precipitation. In this method, 3D fields of wind and temperature values taken from ECMWF gridded analysis are used to drive moisture conservation equations with parameterized microphysical treatment of vapor, liquid, and ice; the evolving field of water vapor is periodically updated or constrained by SSM/I retrievals of precipitable water. Initial results indicate that this diagnostic model can produce realistic large-scale fields of cloud and precipitation. The resulting water vapor analyses agree well with SSM/I and have an additional advantage of being synoptic.

  3. Cool C4 Photosynthesis: Pyruvate Pi Dikinase Expression and Activity Corresponds to the Exceptional Cold Tolerance of Carbon Assimilation in Miscanthus × giganteus12[W][OA

    PubMed Central

    Wang, Dafu; Portis, Archie R.; Moose, Stephen P.; Long, Stephen P.

    2008-01-01

    The bioenergy feedstock grass Miscanthus × giganteus is exceptional among C4 species for its high productivity in cold climates. It can maintain photosynthetically active leaves at temperatures 6°C below the minimum for maize (Zea mays), which allows it a longer growing season in cool climates. Understanding the basis for this difference between these two closely related plants may be critical in adapting maize to colder weather. When M. × giganteus and maize grown at 25°C were transferred to 14°C, light-saturated CO2 assimilation and quantum yield of photosystem II declined by 30% and 40%, respectively, in the first 48 h in these two species. The decline continued in maize but arrested and then recovered partially in M. × giganteus. Within 24 h of the temperature transition, the pyruvate phosphate dikinase (PPDK) protein content per leaf area transiently declined in M. × giganteus but then steadily increased, such that after 7 d the enzyme content was significantly higher than in leaves growing in 25°C. By contrast it declined throughout the chilling period in maize leaves. Rubisco levels remained constant in M. × giganteus but declined in maize. Consistent with increased PPDK protein content, the extractable PPDK activity per unit leaf area (Vmax,ppdk) in cold-grown M. × giganteus leaves was higher than in warm-grown leaves, while Vmax,ppdk was lower in cold-grown than in warm-grown maize. The rate of light activation of PPDK was also slower in cold-grown maize than M. × giganteus. The energy of activation (Ea) of extracted PPDK was lower in cold-grown than warm-grown M. × giganteus but not in maize. The specific activities and Ea of purified recombinant PPDK from M. × giganteus and maize cloned into Escherichia coli were similar. The increase in PPDK protein in the M. × giganteus leaves corresponded to an increase in PPDK mRNA level. These results indicate that of the two enzymes known to limit C4 photosynthesis, increase of PPDK, not Rubisco

  4. Rotary combustor barrel with water-cooled baffles

    SciTech Connect

    Jurusz, M.T.

    1988-04-05

    A combustion barrel in a rotary combustor used for burning solid material is described. The rotary combustor is connected to heat exchanging equipment. The combustion barrel comprises: a generally cylindrical side wall rotatable about a central axis of rotation and having an input end and an exit end, baffle pipes, attached to the interior of the generally cylindrical side wall, extending longitudinally with adjacent baffle pipes separated by a second spacing distance more than twice as large as the first spacing distance, and having first and second pipe ends at the exit and input ends, respectively of the side wall, for agitating the solid material as the combustion barrel is rotated; a ring header, having a generally annular shape, coupled to the heat exchanging equipment, for supplying coolant to, and discharging coolant from, the cooling pipes and the baffle pipes; coupling means for coupling and sealing the first pipe ends of the cooling and baffle pipes to the ring header, supplying coolant to a first set of pipes selected from among the cooling pipes and the baffle pipes and discharging coolant from a second set of pipes corresponding to the remaining ones of the the cooling pipes and the baffle pipes; and return means for returning the coolant from the second ends of the cooling and baffle pipes in the first set of pipes to the ring header via the second set of pipes.

  5. Foulant Characteristics Comparison in Recycling Cooling Water System Makeup by Municipal Reclaimed Water and Surface Water in Power Plant

    PubMed Central

    Ping, Xu; Jing, Wang; Yajun, Zhang; Jie, Wang; Shuai, Si

    2015-01-01

    Due to water shortage, municipal reclaimed water rather than surface water was replenished into recycling cooling water system in power plants in some cities in China. In order to understand the effects of the measure on carbon steel corrosion, characteristics of two kinds of foulant produced in different systems were studied in the paper. Differences between municipal reclaimed water and surface water were analyzed firstly. Then, the weight and the morphology of two kinds of foulant were compared. Moreover, other characteristics including the total number of bacteria, sulfate reducing bacteria, iron bacteria, extracellular polymeric substance (EPS), protein (PN), and polysaccharide (PS) in foulant were analyzed. Based on results, it could be concluded that microbial and corrosive risk would be increased when the system replenished by municipal reclaimed water instead of surface water. PMID:25893132

  6. Foulant characteristics comparison in recycling cooling water system makeup by municipal reclaimed water and surface water in power plant.

    PubMed

    Ping, Xu; Jing, Wang; Yajun, Zhang; Jie, Wang; Shuai, Si

    2015-01-01

    Due to water shortage, municipal reclaimed water rather than surface water was replenished into recycling cooling water system in power plants in some cities in China. In order to understand the effects of the measure on carbon steel corrosion, characteristics of two kinds of foulant produced in different systems were studied in the paper. Differences between municipal reclaimed water and surface water were analyzed firstly. Then, the weight and the morphology of two kinds of foulant were compared. Moreover, other characteristics including the total number of bacteria, sulfate reducing bacteria, iron bacteria, extracellular polymeric substance (EPS), protein (PN), and polysaccharide (PS) in foulant were analyzed. Based on results, it could be concluded that microbial and corrosive risk would be increased when the system replenished by municipal reclaimed water instead of surface water.

  7. Water-soluble cooling lubricants induce airway hyperresponsiveness in rabbits.

    PubMed

    Marek, W; Mensing, T; Fricke, H; Baur, X

    1998-01-01

    Airway hyperresponsiveness (AHR) to water-soluble cooling lubricants (CL) induced by aerosol administered by tracheal tube was studied in a rabbit model of occupational lung disease. Two commercial CL were examined: the first was of the boric acid amine ester type without biozide (CL-BAE), the second was of the sulfonate type with biozide (CL-SB). 50, 5.0 or 0.5 mg/m3 CL was administered over a period of twice 2 h to six different groups of rabbits. Airway responsiveness (AR) to aerosols of 0.2% and 2.0% acetylcholine solution (ACH) was measured before and after each exposure to CL. A control group A of nine animals not exposed to CL showed no significant respiratory responses following inhalation of 0.2% ACH for 1 min. Conversely, inhalation of 2.0% ACH almost doubled the dynamic elastance (Edyn) in the ACH challenge test in this animal group. Airway resistance (RI), Edyn, slope of inspiratory pressure generation (delta Pes/tI), arterial pressure (Pa) and arterial blood gas tensions (PaO2, PaCO2) were not significantly altered during and after exposures to CL. However, after CL-BAE inhalation of 50 and 5 mg/m3 over 4 h, the amplitude of the ACH-induced airway obstruction indicated by the changes in Edyn rose significantly to almost five times the control response before exposure (group C, D, p < 0.005). Similar changes in RI and delta Pes/tI were obtained. After inhalation of 0.5 mg/m3 CL-BAE (group D), no significant changes in AR were observed. Similar to CL-BAE inhalation of 50 mg/m3, CL-SB caused enlarged AR in the ACH challenge test (group E), whereas no significant changes were found after exposure to 5.0 and 0.5 mg/m3 in groups F and G. In summary, CL aerosols with and without biozide in the range of 50 and 5 mg/m3 applied via tracheal tubes increased AR to ACH within 4 h of exposure in a time- and concentration-dependent manner. It has to be assumed that this augmented AR indicates an increased risk of developing lubricant-induced obstructive lung diseases.

  8. Sustained Recycle in Light Water and Sodium-Cooled Reactors

    SciTech Connect

    Steven J. Piet; Samuel E. Bays; Michael A. Pope; Gilles J. Youinou

    2010-11-01

    From a physics standpoint, it is feasible to sustain recycle of used fuel in either thermal or fast reactors. This paper examines multi-recycle potential performance by considering three recycling approaches and calculating several fuel cycle parameters, including heat, gamma, and neutron emission of fresh fuel; radiotoxicity of waste; and uranium utilization. The first recycle approach is homogeneous mixed oxide (MOX) fuel assemblies in a light water reactor (LWR). The transuranic portion of the MOX was varied among Pu, NpPu, NpPuAm, or all-TRU. (All-TRU means all isotopes through Cf-252.) The Pu case was allowed to go to 10% Pu in fresh fuel, but when the minor actinides were included, the transuranic enrichment was kept below 8% to satisfy the expected void reactivity constraint. The uranium portion of the MOX was enriched uranium. That enrichment was increased (to as much as 6.5%) to keep the fuel critical for a typical LWR irradiation. The second approach uses heterogeneous inert matrix fuel (IMF) assemblies in an LWR - a mix of IMF and traditional UOX pins. The uranium-free IMF fuel pins were Pu, NpPu, NpPuAm, or all-TRU. The UOX pins were limited to 4.95% U-235 enrichment. The number of IMF pins was set so that the amount of TRU in discharged fuel from recycle N (from both IMF and UOX pins) was made into the new IMF pins for recycle N+1. Up to 60 of the 264 pins in a fuel assembly were IMF. The assembly-average TRU content was 1-6%. The third approach uses fast reactor oxide fuel in a sodium-cooled fast reactor with transuranic conversion ratio of 0.50 and 1.00. The transuranic conversion ratio is the production of transuranics divided by destruction of transuranics. The FR at CR=0.50 is similar to the CR for the MOX case. The fast reactor cases had a transuranic content of 33-38%, higher than IMF or MOX.

  9. Wetland Water Cooling Partnership: The Use of Constructed Wetlands to Enhance Thermoelectric Power Plant Cooling and Mitigate the Demand of Surface Water Use

    SciTech Connect

    Apfelbaum, Steven; Duvall, Kenneth; Nelson, Theresa; Mensing, Douglas; Bengtson, Harlan; Eppich, John; Penhallegon, Clayton; Thompson, Ry

    2013-09-30

    Through the Phase I study segment of contract #DE-NT0006644 with the U.S. Department of Energy’s National Energy Technology Laboratory, Applied Ecological Services, Inc. and Sterling Energy Services, LLC (the AES/SES Team) explored the use of constructed wetlands to help address stresses on surface water and groundwater resources from thermoelectric power plant cooling and makeup water requirements. The project objectives were crafted to explore and develop implementable water conservation and cooling strategies using constructed wetlands (not existing, naturally occurring wetlands), with the goal of determining if this strategy has the potential to reduce surface water and groundwater withdrawals of thermoelectric power plants throughout the country. Our team’s exploratory work has documented what appears to be a significant and practical potential for augmenting power plant cooling water resources for makeup supply at many, but not all, thermoelectric power plant sites. The intent is to help alleviate stress on existing surface water and groundwater resources through harvesting, storing, polishing and beneficially re-using critical water resources. Through literature review, development of conceptual created wetland plans, and STELLA-based modeling, the AES/SES team has developed heat and water balances for conventional thermoelectric power plants to evaluate wetland size requirements, water use, and comparative cooling technology costs. The ecological literature on organism tolerances to heated waters was used to understand the range of ecological outcomes achievable in created wetlands. This study suggests that wetlands and water harvesting can provide a practical and cost-effective strategy to augment cooling waters for thermoelectric power plants in many geographic settings of the United States, particularly east of the 100th meridian, and in coastal and riverine locations. The study concluded that constructed wetlands can have significant positive

  10. Increased proline loading to phloem and its effects on nitrogen uptake and assimilation in water-stressed white clover (Trifolium repens).

    PubMed

    Lee, Bok-Rye; Jin, Yu Lan; Avice, Jean-Christophe; Cliquet, Jean-Bernard; Ourry, Alain; Kim, Tae-Hwan

    2009-01-01

    The aim of this study was to investigate the physiological significance of increased proline loading to phloem caused by water-deficit stress in relation to nitrogen (N) uptake and assimilation. N uptake and N assimilation were quantified by 15N tracing in well-watered (control) and water deficit-stressed white clover (Trifolium repens). De novo proline synthesis and proline loading to the phloem were also compared between treatments. The relationships among proline concentrations in phloem exudates, N uptake, and assimilation of newly absorbed N were assessed. The newly synthesized proline in the phloem exudates increased rapidly after 3 d of water deficit. The water-deficit treatment significantly reduced the maximum nitrate reductase activity (NRA), and also attenuated de novo synthesis of amino acids and proteins in the roots. The increase in proline concentrations in phloem exudates was closely related to reductions in NRA in the roots, N uptake, and the assimilation of newly absorbed N. The accumulation of proline induced in roots by exogenous proline and NH4Cl treatments was closely associated with the decrease in NRA. These results indicate that increased proline transport to roots via phloem caused by water deficit has a significant influence on the down-regulation of N uptake and the assimilation of newly absorbed N.

  11. Determination of an acceptable assimilable organic carbon (AOC) level for biological stability in water distribution systems with minimized chlorine residual.

    PubMed

    Ohkouchi, Yumiko; Ly, Bich Thuy; Ishikawa, Suguru; Kawano, Yoshihiro; Itoh, Sadahiko

    2013-02-01

    There is considerable interest in minimizing the chlorine residual in Japan because of increasing complaints about a chlorinous odor in drinking water. However, minimizing the chlorine residual causes the microbiological water quality to deteriorate, and stricter control of biodegradable organics in finished water is thus needed to maintain biological stability during water distribution. In this investigation, an acceptable level of assimilable organic carbon (AOC) for biologically stable water with minimized chlorine residual was determined based on the relationship between AOC, the chlorine residual, and bacterial regrowth. In order to prepare water samples containing lower AOC, the fractions of AOC and biodegradable organic matter (BOM) in tap water samples were reduced by converting into biomass after thermal hydrolysis of BOM at alkaline conditions. The batch-mode incubations at different conditions of AOC and chlorine residual were carried out at 20 °C, and the presence or absence of bacterial regrowth was determined. The determined curve for biologically stable water indicated that the acceptable AOC was 10.9 μg C/L at a minimized chlorine residual (0.05 mg Cl(2)/L). This result indicated that AOC removal during current water treatment processes in Japan should be significantly enhanced prior to minimization of the chlorine residual in water distribution.

  12. Reduced light and moderate water deficiency sustain nitrogen assimilation and sucrose degradation at low temperature in durum wheat.

    PubMed

    Majláth, Imre; Darko, Eva; Palla, Balázs; Nagy, Zoltán; Janda, Tibor; Szalai, Gabriella

    2016-02-01

    The rate of carbon and nitrogen assimilation is highly sensitive to stress factors, such as low temperature and drought. Little is known about the role of light in the simultaneous effect of cold and drought. The present study thus focused on the combined effect of mild water deficiency and different light intensities during the early cold hardening in durum wheat (Triticum turgidum ssp. durum L.) cultivars with different levels of cold sensitivity. The results showed that reduced illumination decreased the undesirable effects of photoinhibition in the case of net photosynthesis and nitrate reduction, which may help to sustain these processes at low temperature. Mild water deficiency also had a slight positive effect on the effective quantum efficiency of PSII and the nitrate reductase activity in the cold. Glutamine synthesis was affected by light rather than by water deprivation during cold stress. The invertase activity increased to a greater extent by water deprivation, but an increase in illumination also had a facilitating effect on this enzyme. This suggests that both moderate water deficiency and light have an influence on nitrogen metabolism and sucrose degradation during cold hardening. A possible rise in the soluble sugar content caused by the invertase may compensate for the decline in photosynthetic carbon assimilation indicated by the decrease in net photosynthesis. The changes in the osmotic potential can be also correlated to the enhanced level of invertase activity. Both of them were regulated by light at normal water supply, but not at water deprivation in the cold. However, changes in the metabolic enzyme activities and osmotic adjustment could not be directly contributed to the different levels of cold tolerance of the cultivars in the early acclimation period.

  13. Reply to 'Comment on 'Collisional cooling investigation of THz rotational transitions of water''

    SciTech Connect

    Drouin, Brian J.; Pearson, John C.; Dick, Michael J.

    2010-09-15

    This response describes the authors' reaction to a critique of recent work on the ultracold physics of water. The possibility of spin-selective adsorption occurring in the context of the collisional cooling experiment is discussed.

  14. Water-cooled furnace heads for use with standard muffle tube furnaces

    NASA Technical Reports Server (NTRS)

    Williams, R. J.; Mullins, O.

    1975-01-01

    The design of water-cooled furnace seals for use in high-temperature controlled-atmosphere gas and vacuum studies is presented in detailed engineering drawings. Limiting design factors and advantages are discussed.

  15. 22. DIABLO POWERHOUSE: COOLING WATER PUMPS (WESTINGHOUSE C.S. INDUCTION MOTORS), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. DIABLO POWERHOUSE: COOLING WATER PUMPS (WESTINGHOUSE C.S. INDUCTION MOTORS), 1989. - Skagit Power Development, Diablo Powerhouse, On Skagit River, 6.1 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  16. Use of Produced Water in Recirculated Cooling Systems at Power Generating Facilities

    SciTech Connect

    C. McGowin; M. DiFilippo; L. Weintraub

    2006-06-30

    Tree ring studies indicate that, for the greater part of the last three decades, New Mexico has been relatively 'wet' compared to the long-term historical norm. However, during the last several years, New Mexico has experienced a severe drought. Some researchers are predicting a return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters to supplement current fresh water supplies for power plant operation and cooling and other uses. The U.S. Department of Energy's National Energy Technology Laboratory sponsored three related assessments of water supplies in the San Juan Basin area of the four-corner intersection of Utah, Colorado, Arizona, and New Mexico. These were (1) an assessment of using water produced with oil and gas as a supplemental supply for the San Juan Generating Station (SJGS); (2) a field evaluation of the wet-surface air cooling (WSAC) system at SJGS; and (3) the development of a ZeroNet systems analysis module and an application of the Watershed Risk Management Framework (WARMF) to evaluate a range of water shortage management plans. The study of the possible use of produced water at SJGS showed that produce water must be treated to justify its use in any reasonable quantity at SJGS. The study identified produced water volume and quality, the infrastructure needed to deliver it to SJGS, treatment requirements, and delivery and treatment economics. A number of produced water treatment alternatives that use off-the-shelf technology were evaluated along with the equipment needed for water treatment at SJGS. Wet surface air-cooling (WSAC) technology was tested at the San Juan Generating Station (SJGS) to determine its capacity to cool power plant circulating water using degraded water. WSAC is a commercial cooling technology and has been used for many years to cool and/or condense process fluids. The purpose of the pilot test was to determine if WSAC

  17. Repair of a water-cooled field coil for a hydroelectric motor/generator

    SciTech Connect

    Miller, L.J. III

    1983-01-01

    Four reversible pump/turbine units at TVA's Raccoon Mountain Pumped-Storage Plant were placed in service in 1978 to 1979. The stator and rotor windings for the motor/generators are direct water cooled. This paper describes repairs to a water-cooled coil of one of the 24 field poles of Unit No. 3 motor/generator placed in service in February 1979.

  18. In Hot Water: A Cooling Tower Case Study. Instructor's Manual

    ERIC Educational Resources Information Center

    Cochran, Justin; Raju, P. K.; Sankar, Chetan

    2005-01-01

    Vogtle Electric Generating Plant operated by Southern Nuclear Operating Company, a subsidiary of Southern Company, has found itself at a decision point. Vogtle depends on their natural draft cooling towers to remove heat from the power cycle. Depending on the efficiency of the towers, the cycle can realize more or less power output. The efficiency…

  19. In Hot Water: A Cooling Tower Case Study

    ERIC Educational Resources Information Center

    Cochran, Justin; Raju, P. K.; Sankar, Chetan

    2005-01-01

    Problem Statement: Vogtle Electric Generating Plant operated by Southern Nuclear Operating Company, a subsidiary of Southern Company, has found itself at a decision point. Vogtle depends on their natural draft cooling towers to remove heat from the power cycle. Depending on the efficiency of the towers, the cycle can realize more or less power…

  20. In Hot Water: A Cooling Tower Case Study. Instructor's Manual

    ERIC Educational Resources Information Center

    Cochran, Justin; Raju, P. K.; Sankar, Chetan

    2005-01-01

    Vogtle Electric Generating Plant operated by Southern Nuclear Operating Company, a subsidiary of Southern Company, has found itself at a decision point. Vogtle depends on their natural draft cooling towers to remove heat from the power cycle. Depending on the efficiency of the towers, the cycle can realize more or less power output. The efficiency…

  1. In Hot Water: A Cooling Tower Case Study

    ERIC Educational Resources Information Center

    Cochran, Justin; Raju, P. K.; Sankar, Chetan

    2005-01-01

    Problem Statement: Vogtle Electric Generating Plant operated by Southern Nuclear Operating Company, a subsidiary of Southern Company, has found itself at a decision point. Vogtle depends on their natural draft cooling towers to remove heat from the power cycle. Depending on the efficiency of the towers, the cycle can realize more or less power…

  2. Algal Nitrate Assimilation and Productivity in an Urban, Concrete-Lined Stream Dominated by Tertiary Treated Municipal Waste-Water

    NASA Astrophysics Data System (ADS)

    Kent, R. H.; Burton, C. A.

    2001-12-01

    This study examined the extent and variabiltity of nitrate loss in a 2.85 km reach of Cucamonga Creek, which is concrete-lined and dominated by treated municipal waste-water. Primary production was measured to determine if the loss could be attributed to algal assimilation. Samples for nitrite plus nitrate analysis were collected at the top and bottom of the study reach every hour throughout the 24-hour sampling period; samples for analyses of other parameters were collected less frequently. Water temperature, dissolved oxygen (DO), pH and specific conductance were monitored continuously throughout the sampling period using in-stream probes. During the two weeks prior to the study, periphyton samples were collected periodically at four stations along the reach for standing crop measurements and a growth rate time-series using Chlorophyll A and ash-free-dry mass. Water samples from the upstream station were compared to those taken an hour later (the approximate travel time) at the downstream station. Nitrate concentrations were lower at the downstream station in 21 of 25 of the paired samples, indicating nearly continuous loss in the reach. The total loss of NO3 for the day was about 0.71 g as N/m2. Most of the loss occurred during daylight hours, with the peak occurring at midday. During the night, CO2 concentrations were relatively constant at about 25 mg/L. Concentrations began to decline at sunrise, and declined to 0 mg/L at the lower site after midday. Peak nitrate loss occurred at about the same time as the CO2 concentration was at its minimum. DO declined slightly during the night, began to rise at sunrise, reached a peak during midday, and declined in late afternoon through evening; pH followed a similar pattern. Net primary productivity, as measured by the differences in DO between the two sites was 13 g O2/m2 for the day. Using the Redfield ratio, the predicted nitrate assimilation is about 0.66 g NO3 as N/m2. The continuous loss of nitrate between the two

  3. Assimilation of Gridded Snow Water Equivalent and Satellite Snowcover Products for Semi- arid Mountain Basins in a Hydrologic Model

    NASA Astrophysics Data System (ADS)

    Dressler, K. A.; Moradkhani, H.

    2006-12-01

    This study examines the Particle Filter (PF) assimilation technique for distributed estimates of snow covered area (SCA) and snow-water equivalent (SWE) to update hydrologic model states. PF is a class of Bayesian filtering algorithms derived from a discrete description of Bayes rule well-suited for updating the nonlinear model states, resulting in improved model outputs. Assimilation runs are applied to the USGS Precipitation Runoff Modeling System (PRMS) hydrologic model using 1-km2 SCA derived from NOAA Advanced Very High Resolution Radiometer imagery and 1-km2 SWE estimates interpolated from National Resources Conservation Service Snow Telemetry (SNOTEL) point measurements for a six-year period (1995-2000). Two headwater basins within the Rio Grande (i.e. upper Rio Grande River basin) and Salt River (i.e. Black River basin) drainages in the Southwestern United States are contrasted. Base runs indicate measured SCA and SWE estimates were consistently lower than values estimated from temperature and precipitation within PRMS. The greatest differences occurred in the relatively complex terrain of the Rio Grande basin, as opposed to the relatively homogeneous terrain of the Black River basin, where differences were small. Differences between modeled and measured snow were different for the accumulation period versus the ablation period and had an elevational trend. Direct insertion of measured snowfields into a version of PRMS calibrated to achieve water balance led to reduced performance in estimating streamflow for the Rio Grande and increased performance in estimating streamflow for the Black River basin. However, PF as a sequential Monte Carlo technique is able to take the most advantage of information content in the data which relaxes the need for restrictive assumptions in direct insertion and even other assimilation techniques. Therefore, in this study we demonstrate the features of such a filtering technique with the potential to estimate the uncertainty of

  4. Comparing removal of trace organic compounds and assimilable organic carbon (AOC) at advanced and traditional water treatment plants.

    PubMed

    Lou, Jie-Chung; Lin, Chung-Yi; Han, Jia-Yun; Tseng, Wei-Biu; Hsu, Kai-Lin; Chang, Ting-Wei

    2012-06-01

    Stability of drinking water can be indicated by the assimilable organic carbon (AOC). This AOC value represents the regrowth capacity of microorganisms and has large impacts on the quality of drinking water in a distribution system. With respect to the effectiveness of traditional and advanced processing methods in removing trace organic compounds (including TOC, DOC, UV(254), and AOC) from water, experimental results indicate that the removal rate of AOC at the Cheng Ching Lake water treatment plant (which utilizes advanced water treatment processes, and is hereinafter referred to as CCLWTP) is 54%, while the removal rate of AOC at the Gong Yuan water treatment plant (which uses traditional water treatment processes, and is hereinafter referred to as GYWTP) is 36%. In advanced water treatment units, new coagulation-sedimentation processes, rapid filters, and biological activated carbon filters can effectively remove AOC, total organic carbon (TOC), and dissolved organic carbon (DOC). In traditional water treatment units, coagulation-sedimentation processes are most effective in removing AOC. Simulation results and calculations made using the AutoNet method indicate that TOC, TDS, NH(3)-N, and NO(3)-N should be regularly monitored in the CCLWTP, and that TOC, temperature, and NH(3)-N should be regularly monitored in the GYWTP.

  5. Water cooled breeder program summary report (LWBR (Light Water Breeder Reactor) development program)

    SciTech Connect

    Not Available

    1987-10-01

    The purpose of the Department of Energy Water Cooled Breeder Program was to demonstrate pratical breeding in a uranium-233/thorium fueled core while producing electrical energy in a commercial water reactor generating station. A demonstration Light Water Breeder Reactor (LWBR) was successfully operated for more than 29,000 effective full power hours in the Shippingport Atomic Power Station. The reactor operated with an availability factor of 76% and had a gross electrical output of 2,128,943,470 kilowatt hours. Following operation, the expended core was examined and no evidence of any fuel element defects was found. Nondestructive assay of 524 fuel rods determined that 1.39 percent more fissile fuel was present at the end of core life than at the beginning, proving that breeding had occurred. This demonstrates the existence of a vast source of electrical energy using plentiful domestic thorium potentially capable of supplying the entire national need for many centuries. To build on the successful design and operation of the Shippingport Breeder Core and to provide the technology to implement this concept, several reactor designs of large breeders and prebreeders were developed for commercial-sized plants of 900--1000 Mw(e) net. This report summarizes the Water Cooled Breeder Program from its inception in 1965 to its completion in 1987. Four hundred thirty-six technical reports are referenced which document the work conducted as part of this program. This work demonstrated that the Light Water Breeder Reactor is a viable alternative as a PWR replacement in the next generation of nuclear reactors. This transition would only require a minimum of change in design and fabrication of the reactor and operation of the plant.

  6. Can we Constrain Carbon Assimilation and Allocation in a Multi-Species Hardwood Forest Using Water Flux Measurements?

    NASA Astrophysics Data System (ADS)

    Schäfer, K. V.; Oren, R.; Poulter, B.; Oishi, A. C.; Ellsworth, D. S.; Katul, G. G.

    2002-12-01

    Annual carbon budgets of terrestrial ecosystems and how climate perturbations alter them remain an active research area. A combination of measurements collected at multiple spatial and temporal scales is used in conjunction with models to quantify the relationship between water fluxes and C budgets. A multi-layer model for canopy CO2 uptake is employed in which the primary input is mean canopy stomatal conductance scaled via sap-flux of water vapor (gw) in a multi-species hardwood forest stand at the Duke Forest, NC, USA. The ecophysiological model relates stomatal conductance of CO2 (gCO2) to the ratio of internal (Ci) to external CO2 concentration (Ca) that is then used to calculate net assimilation (Anet) after correction for differences in diffusivities. Modeled assimilation rates agreed well with instantaneous leaf level measurements in the upper canopy, collected via porometry and monthly daytime carbon fluxes measured via eddy-flux augmented with daytime soil and wood respiration. Additionally annual biomass production augmented with construction and maintenance respiration agreed well with annual carbon uptake. The combination of sapflux measurements and the model provide reliable constrains on CO2 budgets in terrestrial ecosystems and showed lower carbon uptake in hardwood forest of the southeast than previously published.

  7. A survey on levels and seasonal changes of assimilable organic carbon (AOC) and its precursors in drinking water.

    PubMed

    Ohkouchi, Yumiko; Ly, Bich Thuy; Ishikawa, Suguru; Aoki, Yusuke; Echigo, Shinya; Itoh, Sadahiko

    2011-10-01

    In Japan, customers' concerns about chlorinous odour in drinking water have been increasing. One promising approach for reducing chlorinous odour is the minimization of residual chlorine in water distribution, which requires stricter control of organics to maintain biological stability in water supply systems. In this investigation, the levels and seasonal changes of assimilable organic carbon (AOC) and its precursors in drinking water were surveyed to accumulate information on organics in terms of biological stability. In tap water samples purified through rapid sand filtration processes, the average AOC concentration was 174 microgC/L in winter and 60 microgC/L in summer. This difference seemed to reflect the seasonal changes of AOC in the natural aquatic environment. On the other hand, very little or no AOC could be removed after use of an ozonation-biological activated carbon (BAC) process. Especially in winter, waterworks should pay attention to BAC operating conditions to improve AOC removal. The storage of BAC effluent with residual chlorine at 0.05-0.15 mgCl2/L increased AOC drastically. This result indicated the possibility that abundant AOC precursors remaining in the finished water could contribute to newly AOC formation during water distribution with minimized residual chlorine. Combined amino acids, which remained at roughly equivalent to AOC in finished water, were identified as major AOC precursors. Prior to minimization of residual chlorine, enhancement of the removal abilities for both AOC and its precursors would be necessary.

  8. The oxygen isotope enrichment of leaf-exported assimilates--does it always reflect lamina leaf water enrichment?

    PubMed

    Gessler, Arthur; Brandes, Elke; Keitel, Claudia; Boda, Sonja; Kayler, Zachary E; Granier, André; Barbour, Margaret; Farquhar, Graham D; Treydte, Kerstin

    2013-10-01

    The oxygen stable isotope composition of plant organic matter (OM) (particularly of wood and cellulose in the tree ring archive) is valuable in studies of plant-climate interaction, but there is a lack of information on the transfer of the isotope signal from the leaf to heterotrophic tissues. We studied the oxygen isotopic composition and its enrichment above source water of leaf water over diel courses in five tree species covering a broad range of life forms. We tracked the transfer of the isotopic signal to leaf water-soluble OM and further to phloem-transported OM. Observed leaf water evaporative enrichment was consistent with values predicted from mechanistic models taking into account nonsteady-state conditions. While leaf water-soluble OM showed the expected (18)O enrichment in all species, phloem sugars were less enriched than expected from leaf water enrichment in Scots pine (Pinus sylvestris), European larch (Larix decidua) and Alpine ash (Eucalyptus delegatensis). Oxygen atom exchange with nonenriched water during phloem loading and transport, as well as a significant contribution of assimilates from bark photosynthesis, can explain these phloem (18)O enrichment patterns. Our results indicate species-specific uncoupling between the leaf water and the OM oxygen isotope signal, which is important for the interpretation of tree ring data. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  9. The oxygen isotope enrichment of leaf-exported assimilates – does it always reflect lamina leaf water enrichment?

    PubMed Central

    Gessler, Arthur; Brandes, Elke; Keitel, Claudia; Boda, Sonja; Kayler, Zachary E; Granier, André; Barbour, Margaret; Farquhar, Graham D; Treydte, Kerstin

    2013-01-01

    The oxygen stable isotope composition of plant organic matter (OM) (particularly of wood and cellulose in the tree ring archive) is valuable in studies of plant–climate interaction, but there is a lack of information on the transfer of the isotope signal from the leaf to heterotrophic tissues. We studied the oxygen isotopic composition and its enrichment above source water of leaf water over diel courses in five tree species covering a broad range of life forms. We tracked the transfer of the isotopic signal to leaf water-soluble OM and further to phloem-transported OM. Observed leaf water evaporative enrichment was consistent with values predicted from mechanistic models taking into account nonsteady-state conditions. While leaf water-soluble OM showed the expected 18O enrichment in all species, phloem sugars were less enriched than expected from leaf water enrichment in Scots pine (Pinus sylvestris), European larch (Larix decidua) and Alpine ash (Eucalyptus delegatensis). Oxygen atom exchange with nonenriched water during phloem loading and transport, as well as a significant contribution of assimilates from bark photosynthesis, can explain these phloem 18O enrichment patterns. Our results indicate species-specific uncoupling between the leaf water and the OM oxygen isotope signal, which is important for the interpretation of tree ring data. PMID:23763637

  10. Implications of Transitioning from De Facto to Engineered Water Reuse for Power Plant Cooling.

    PubMed

    Barker, Zachary A; Stillwell, Ashlynn S

    2016-05-17

    Thermoelectric power plants demand large quantities of cooling water, and can use alternative sources like treated wastewater (reclaimed water); however, such alternatives generate many uncertainties. De facto water reuse, or the incidental presence of wastewater effluent in a water source, is common at power plants, representing baseline conditions. In many cases, power plants would retrofit open-loop systems to cooling towers to use reclaimed water. To evaluate the feasibility of reclaimed water use, we compared hydrologic and economic conditions at power plants under three scenarios: quantified de facto reuse, de facto reuse with cooling tower retrofits, and modeled engineered reuse conditions. We created a genetic algorithm to estimate costs and model optimal conditions. To assess power plant performance, we evaluated reliability metrics for thermal variances and generation capacity loss as a function of water temperature. Applying our analysis to the greater Chicago area, we observed high de facto reuse for some power plants and substantial costs for retrofitting to use reclaimed water. Conversely, the gains in reliability and performance through engineered reuse with cooling towers outweighed the energy investment in reclaimed water pumping. Our analysis yields quantitative results of reclaimed water feasibility and can inform sustainable management of water and energy.

  11. Energy penalty analysis of possible cooling water intake structurerequirements on existing coal-fired power plants.

    SciTech Connect

    Veil, J. A.; Littleton, D. J.; Gross, R. W.; Smith, D. N.; Parsons, E.L., Jr.; Shelton, W. W.; Feeley, T. J.; McGurl, G. V.

    2006-11-27

    Section 316(b) of the Clean Water Act requires that cooling water intake structures must reflect the best technology available for minimizing adverse environmental impact. Many existing power plants in the United States utilize once-through cooling systems to condense steam. Once-through systems withdraw large volumes (often hundreds of millions of gallons per day) of water from surface water bodies. As the water is withdrawn, fish and other aquatic organisms can be trapped against the screens or other parts of the intake structure (impingement) or if small enough, can pass through the intake structure and be transported through the cooling system to the condenser (entrainment). Both of these processes can injure or kill the organisms. EPA adopted 316(b) regulations for new facilities (Phase I) on December 18, 2001. Under the final rule, most new facilities could be expected to install recirculating cooling systems, primarily wet cooling towers. The EPA Administrator signed proposed 316(b) regulations for existing facilities (Phase II) on February 28, 2002. The lead option in this proposal would allow most existing facilities to achieve compliance without requiring them to convert once-through cooling systems to recirculating systems. However, one of the alternate options being proposed would require recirculating cooling in selected plants. EPA is considering various options to determine best technology available. Among the options under consideration are wet-cooling towers and dry-cooling towers. Both types of towers are considered to be part of recirculating cooling systems, in which the cooling water is continuously recycled from the condenser, where it absorbs heat by cooling and condensing steam, to the tower, where it rejects heat to the atmosphere before returning to the condenser. Some water is lost to evaporation (wet tower only) and other water is removed from the recirculating system as a blow down stream to control the building up of suspended and

  12. Emergency makeup flow model for the K-reactor cooling water basin

    SciTech Connect

    Barbour, K.L.

    1994-12-31

    The Savannah River site installed the K-reactor cooling tower in 1993 to replace river water supplied to a 25-million-gal cooling basin with cooling tower recirculation. The reactor accident safety analysis assumes that cooling water recirculation is lost during the accident and basin level will drop. Emergency river water supply makeup valves will be opened manually to restore basin makeup and level and maintain shutdown safety. A hydraulic model scopes out valve flow response as the valves are opened. Scoping objectives are (a) valve flow rate response, (b) volumetric makeup with time, and (c) total volumetric makeup effect on basin emergency operating operating procedures. Model results could influence basin emergency operating procedures development before actual field test data are obtained.

  13. Fluidized bed heat exchanger with water cooled air distributor and dust hopper

    DOEpatents

    Jukkola, Walfred W.; Leon, Albert M.; Van Dyk, Jr., Garritt C.; McCoy, Daniel E.; Fisher, Barry L.; Saiers, Timothy L.; Karstetter, Marlin E.

    1981-11-24

    A fluidized bed heat exchanger is provided in which air is passed through a bed of particulate material containing fuel. A steam-water natural circulation system is provided for heat exchange and the housing of the heat exchanger has a water-wall type construction. Vertical in-bed heat exchange tubes are provided and the air distributor is water-cooled. A water-cooled dust hopper is provided in the housing to collect particulates from the combustion gases and separate the combustion zone from a volume within said housing in which convection heat exchange tubes are provided to extract heat from the exiting combustion gases.

  14. Experiment Study on Corrosion Control Using Coking Wastewater as Circulating Cooling Water

    NASA Astrophysics Data System (ADS)

    Zhang, Huanzhen; Dong, Changqing; Bian, Lei; Zhao, Qian

    The coking wastewater drainage will bring severe water environmental pollution, so it is necessary to change the coking wastewater into resource. The reuse of pre-treated coking wastewater as make-up water for circulating cooling system is an important way. To prevent the circulating cooling system corrosion, the characteristic and the corrosion control technology and the effect of the classic corrosion inhibitors in the circulating cooling water system were studied by static experiment and dynamic experiment based on water quality stabilization theory. The results indicate that the corrosion in circulating cooling system is mainly spot corrosion caused by pollutants in coking wastewater, and the corrosion inhibition technology on the model of precipitated membrane based on phosphor series should be preferred. The mixed corrosion inhibitors HEDP and Zn 2+ optimally selected by experiment can form a firm corrosion inhibition membrane on heat transfer surface, and the corrosion inhibition rate could reach 85.6%. The corrosion rate of common carbon steel is 0.105 mm/a, which could satisfy the criterion of > Design criterion of the industrial circulating cooling water treatment > (GB 50050-95). The practical application to the circulating cooling system shows that the mixed corrosion inhibitors HEDP and Zn 2+ can control the corrosion in the system economically when the concentration multiple is 2-2.2, which opens up a feasible way for changing the coking wastewater into resource.

  15. Improving of the photovoltaic / thermal system performance using water cooling technique

    NASA Astrophysics Data System (ADS)

    Hussien, Hashim A.; Numan, Ali H.; Abdulmunem, Abdulmunem R.

    2015-04-01

    This work is devoted to improving the electrical efficiency by reducing the rate of thermal energy of a photovoltaic/thermal system (PV/T).This is achieved by design cooling technique which consists of a heat exchanger and water circulating pipes placed at PV module rear surface to solve the problem of the high heat stored inside the PV cells during the operation. An experimental rig is designed to investigate and evaluate PV module performance with the proposed cooling technique. This cooling technique is the first work in Iraq to dissipate the heat from PV module. The experimental results indicated that due to the heat loss by convection between water and the PV panel's upper surface, an increase of output power is achieved. It was found that without active cooling, the temperature of the PV module was high and solar cells could only achieve a conversion efficiency of about 8%. However, when the PV module was operated under active water cooling condition, the temperature was dropped from 76.8°C without cooling to 70.1°C with active cooling. This temperature dropping led to increase in the electrical efficiency of solar panel to 9.8% at optimum mass flow rate (0.2L/s) and thermal efficiency to (12.3%).

  16. Water-lithium bromide double-effect absorption cooling analysis. Final report

    SciTech Connect

    Vliet, G.C.; Lawson, M.B.; Lithgow, R.A.

    1980-12-01

    This investigation involved the development of a numerical model for the transient simulation of the double-effect, water-lithium bromide absorption cooling machine, and the use of the model to determine the effect of the various design and input variables on the absorption unit performance. The performance parameters considered were coefficient of performance and cooling capacity. The sensitivity analysis was performed by selecting a nominal condition and determining performance sensitivity for each variable with others held constant. The variables considered in the study include source hot water, cooling water, and chilled water temperatures; source hot water, cooling water, and chilled water flow rates; solution circulation rate; heat exchanger areas; pressure drop between evaporator and absorber; solution pump characteristics; and refrigerant flow control methods. The performance sensitivity study indicated in particular that the distribution of heat exchanger area among the various (seven) heat exchange components is a very important design consideration. Moreover, it indicated that the method of flow control of the first effect refrigerant vapor through the second effect is a critical design feature when absorption units operate over a significant range of cooling capacity. The model was used to predict the performance of the Trane absorption unit with fairly good accuracy. The dynamic model should be valuable as a design tool for developing new absorption machines or modifying current machines to make them optimal based on current and future energy costs.

  17. The impact of water use fees on dispatching and water requirements for water-cooled power plants in Texas.

    PubMed

    Sanders, Kelly T; Blackhurst, Michael F; King, Carey W; Webber, Michael E

    2014-06-17

    We utilize a unit commitment and dispatch model to estimate how water use fees on power generators would affect dispatching and water requirements by the power sector in the Electric Reliability Council of Texas' (ERCOT) electric grid. Fees ranging from 10 to 1000 USD per acre-foot were separately applied to water withdrawals and consumption. Fees were chosen to be comparable in cost to a range of water supply projects proposed in the Texas Water Development Board's State Water Plan to meet demand through 2050. We found that these fees can reduce water withdrawals and consumption for cooling thermoelectric power plants in ERCOT by as much as 75% and 23%, respectively. To achieve these water savings, wholesale electricity generation costs might increase as much as 120% based on 2011 fuel costs and generation characteristics. We estimate that water saved through these fees is not as cost-effective as conventional long-term water supply projects. However, the electric grid offers short-term flexibility that conventional water supply projects do not. Furthermore, this manuscript discusses conditions under which the grid could be effective at "supplying" water, particularly during emergency drought conditions, by changing its operational conditions.

  18. Cooling of Gas Turbines. 6; Computed Temperature Distribution Through Cross Section of Water-Cooled Turbine Blade

    NASA Technical Reports Server (NTRS)

    Livingood, John N. B.; Sams, Eldon W.

    1947-01-01

    A theoretical analysis of the cross-sectional temperature distribution of a water-cooled turbine blade was made using the relaxation method to solve the differential equation derived from the analysis. The analysis was applied to specific turbine blade and the studies icluded investigations of the accuracy of simple methods to determine the temperature distribution along the mean line of the rear part of the blade, of the possible effect of varying the perimetric distribution of the hot gas-to -metal heat transfer coefficient, and of the effect of changing the thermal conductivity of the blade metal for a constant cross sectional area blade with two quarter inch diameter coolant passages.

  19. Assimilable Organic Carbon (AOC) in Soil Water Extracts Using Vibrio harveyi BB721 and Its Implication for Microbial Biomass

    PubMed Central

    Ma, Jincai; Ibekwe, A. Mark; Leddy, Menu; Yang, Ching-Hong; Crowley, David E.

    2012-01-01

    Assimilable organic carbon (AOC) is commonly used to measure the growth potential of microorganisms in water, but has not yet been investigated for measuring microbial growth potential in soils. In this study, a simple, rapid, and non-growth based assay to determine AOC in soil was developed using a naturally occurring luminous strain Vibrio harveyi BB721 to determine the fraction of low molecular weight organic carbon in soil water extract. Calibration of the assay was achieved by measuring the luminescence intensity of starved V. harveyi BB721 cells in the late exponential phase with a concentration range from 0 to 800 µg l−1 glucose (equivalent to 0–16.0 mg glucose C kg−1 soil) with the detection limit of 10 µg l−1 equivalent to 0.20 mg glucose C kg−1 soil. Results showed that bioluminescence was proportional to the concentration of glucose added to soil. The luminescence intensity of the cells was highly pH dependent and the optimal pH was about 7.0. The average AOC concentration in 32 soils tested was 2.9±2.2 mg glucose C kg−1. Our data showed that AOC levels in soil water extracts were significantly correlated (P<0.05) with microbial biomass determined as microbial biomass carbon, indicating that the AOC concentrations determined by the method developed might be a good indicator of soil microbial biomass. Our findings provide a new approach that may be used to determine AOC in environmental samples using a non-growth bioluminescence based assay. Understanding the levels of AOC in soil water extract provides new insights into our ability to estimate the most available carbon pool to bacteria in soil that may be easily assimilated into cells for many metabolic processes and suggest possible the links between AOC, microbial regrowth potential, and microbial biomass in soils. PMID:22679477

  20. Streamflow and water balance intercomparisons of four land surface models in the North American Land Data Assimilation System project

    NASA Astrophysics Data System (ADS)

    Lohmann, Dag; Mitchell, Kenneth E.; Houser, Paul R.; Wood, Eric F.; Schaake, John C.; Robock, Alan; Cosgrove, Brian A.; Sheffield, Justin; Duan, Qingyun; Luo, Lifeng; Higgins, R. Wayne; Pinker, Rachel T.; Tarpley, J. Dan

    2004-04-01

    This paper is part of a series of papers about the multi-institutional North American Land Data Assimilation System (NLDAS) project. It compares and evaluates streamflow and water balance results from four different land surface models (LSMs) within the continental United States. These LSMs have been run for the retrospective period from 1 October 1996 to 30 September 1999 forced by atmospheric observations from the Eta Data Assimilation System (EDAS) analysis, measured precipitation, and satellite-derived downward solar radiation. These model runs were performed on a common 1/8° latitude-longitude grid and used the same database for soil and vegetation classifications. We have evaluated these simulations using U.S. Geological Survey (USGS) measured daily streamflow data for 9 large major basins and 1145 small- to medium-sized basins from 23 km2 to 10,000 km2 distributed over the NLDAS domain. Model runoff was routed with a common distributed and a lumped optimized linear routing model. The diagnosis of the model water balance results demonstrates strengths and weaknesses in the models, our insufficient knowledge of ad hoc parameters used for the model runs, the interdependence of model structure and model physics, and the lack of good forcing data in parts of the United States, especially in regions with extended snow cover. Overall, the differences between the LSM water balance terms are of the same magnitude as the mean water balance terms themselves. The modeled mean annual runoff shows large regional differences by a factor of up to 4 between models. The corresponding difference in mean annual evapotranspiration is about a factor of 2. The analysis of runoff timing for the LSMs demonstrates the importance of correct snowmelt timing, where the resulting differences in streamflow timing can be up to four months. Runoff is underestimated by all LSMs in areas with significant snowfall.

  1. Evaluation of water cooled supersonic temperature and pressure probes for application to 2000 F flows

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas T.; Seiner, John M.

    1990-01-01

    The development of water cooled supersonic probes used to study high temperature jet plumes is addressed. These probes are: total pressure, static pressure, and total temperature. The motivation for these experiments is the determination of high temperature supersonic jet mean flow properties. A 3.54 inch exit diameter water cooled nozzle was used in the tests. It is designed for exit Mach 2 at 2000 F exit total temperature. Tests were conducted using water cooled probes capable of operating in Mach 2 flow, up to 2000 F total temperature. Of the two designs tested, an annular cooling method was chosen as superior. Data at the jet exit planes, and along the jet centerline, were obtained for total temperatures of 900 F, 1500 F, and 2000 F, for each of the probes. The data obtained from the total and static pressure probes are consistent with prior low temperature results. However, the data obtained from the total temperature probe was affected by the water coolant. The total temperature probe was tested up to 2000 F with, and without, the cooling system turned on to better understand the heat transfer process at the thermocouple bead. The rate of heat transfer across the thermocouple bead was greater when the coolant was turned on than when the coolant was turned off. This accounted for the lower temperature measurement by the cooled probe. The velocity and Mach number at the exit plane and centerline locations were determined from the Rayleigh-Pitot tube formula.

  2. Data assimilation of GRACE terrestrial water storage estimates into a regional hydrological model of the Rhine River basin

    NASA Astrophysics Data System (ADS)

    Tangdamrongsub, N.; Steele-Dunne, S. C.; Gunter, B. C.; Ditmar, P. G.; Weerts, A. H.

    2015-04-01

    The ability to estimate terrestrial water storage (TWS) realistically is essential for understanding past hydrological events and predicting future changes in the hydrological cycle. Inadequacies in model physics, uncertainty in model land parameters, and uncertainties in meteorological data commonly limit the accuracy of hydrological models in simulating TWS. In an effort to improve model performance, this study investigated the benefits of assimilating TWS estimates derived from the Gravity Recovery and Climate Experiment (GRACE) data into the OpenStreams wflow_hbv model using an ensemble Kalman filter (EnKF) approach. The study area chosen was the Rhine River basin, which has both well-calibrated model parameters and high-quality forcing data that were used for experimentation and comparison. Four different case studies were examined which were designed to evaluate different levels of forcing data quality and resolution including those typical of other less well-monitored river basins. The results were validated using in situ groundwater (GW) and stream gauge data. The analysis showed a noticeable improvement in GW estimates when GRACE data were assimilated, with a best-case improvement of correlation coefficient from 0.31 to 0.53 and root mean square error (RMSE) from 8.4 to 5.4 cm compared to the reference (ensemble open-loop) case. For the data-sparse case, the best-case GW estimates increased the correlation coefficient from 0.46 to 0.61 and decreased the RMSE by 35%. For the average improvement of GW estimates (for all four cases), the correlation coefficient increases from 0.6 to 0.7 and the RMSE was reduced by 15%. Only a slight overall improvement was observed in streamflow estimates when GRACE data were assimilated. Further analysis suggested that this is likely due to sporadic short-term, but sizeable, errors in the forcing data and the lack of sufficient constraints on the soil moisture component. Overall, the results highlight the benefit of

  3. Controlling the Distribution of Cold Water in Air Cooling Systems of Underground Mines

    NASA Astrophysics Data System (ADS)

    Szlązak, Nikodem; Obracaj, Dariusz; Swolkień, Justyna; Piergies, Kazimierz

    2016-12-01

    In Polish underground mines in which excavations are subjected to high heat load, central and group cooling systems based on indirect cooling units are implemented. Chilled water, referred to as cold water and produced in chillers, is distributed through a pipeline network to air coolers located in mining and development districts. The coolers are often moved to other locations and the pipeline network undergoes constant modification. In such a system, parameters of cold water in different branches of the pipeline network need to be controlled. The article presents the principles for controlling the cooling capacity of air coolers installed in an underground mine. Also, the authors propose automatic control of water flow rate in underground pipeline network and in particular coolers, depending on the temporary cooling load in the system. The principles of such a system, controlling cold water distribution, and the functions of its individual components are described. Finally, an example of an automatic control of water flow rate in a central cooling system currently implemented in a mine is presented.

  4. Assimilation of GRACE Terrestrial Water Storage into a Land Surface Model: Evaluation 1 and Potential Value for Drought Monitoring in Western and Central Europe

    NASA Technical Reports Server (NTRS)

    Li, Bailing; Rodell, Matthew; Zaitchik, Benjamin F.; Reichle, Rolf H.; Koster, Randal D.; van Dam, Tonie M.

    2012-01-01

    A land surface model s ability to simulate states (e.g., soil moisture) and fluxes (e.g., runoff) is limited by uncertainties in meteorological forcing and parameter inputs as well as inadequacies in model physics. In this study, anomalies of terrestrial water storage (TWS) observed by the Gravity Recovery and Climate Experiment (GRACE) satellite mission were assimilated into the NASA Catchment land surface model in western and central Europe for a 7-year period, using a previously developed ensemble Kalman smoother. GRACE data assimilation led to improved runoff correlations with gauge data in 17 out of 18 hydrological basins, even in basins smaller than the effective resolution of GRACE. Improvements in root zone soil moisture were less conclusive, partly due to the shortness of the in situ data record. In addition to improving temporal correlations, GRACE data assimilation also reduced increasing trends in simulated monthly TWS and runoff associated with increasing rates of precipitation. GRACE assimilated root zone soil moisture and TWS fields exhibited significant changes in their dryness rankings relative to those without data assimilation, suggesting that GRACE data assimilation could have a substantial impact on drought monitoring. Signals of drought in GRACE TWS correlated well with MODIS Normalized Difference Vegetation Index (NDVI) data in most areas. Although they detected the same droughts during warm seasons, drought signatures in GRACE derived TWS exhibited greater persistence than those in NDVI throughout all seasons, in part due to limitations associated with the seasonality of vegetation.

  5. Assimilable organic carbon release, chemical migration, and drinking water impacts of multiple brands of plastic pipes available in the USA

    NASA Astrophysics Data System (ADS)

    Connell, Matthew

    Increased installation of polymer potable water pipes in United States plumbing systems has created a need to thoroughly evaluate their water quality impacts. Eleven brands of new polymer drinking water pipe were evaluated for assimilable organic carbon (AOC) release at room temperature for 28 days. They included polyvinyl chloride (PVC), high-density polyethylene (HDPE), polypropylene (PP), and cross-linked polyethylene (PEX) pipes. Three of eight PEX pipe brands exceeded a 100 microg/L AOC threshold for microbial regrowth for the first exposure period and no brands exceeded this value on day 28. No detectable increase in AOC was found for PP and PEX-a1 pipes; the remaining pipe brands contributed marginal AOC levels. Water quality impacts were more fully evaluated for two brands of PEX-b and one brand of PP pipe. PEX pipes released more total organic carbon (TOC), volatile organic compounds (VOC), and semivolatile organic compounds (SVOC) and caused greater odor than the PP pipe. All three materials showed reductions in these water quality parameters over 30 days. Three PEX pipe field studies revealed that aged systems did not display more intense odors than distribution systems. However, the organic releases from polymer pipes may still alter water quality and contribute to rapid microbial growth, even though the aesthetic impacts are temporary.

  6. Assimilation of TOPEX Sea Level Measurements with a Reduced-Gravity, Shallow Water Model of the Tropical Pacific Ocean

    NASA Technical Reports Server (NTRS)

    Fukumori, Ichiro

    1995-01-01

    Sea surface height variability measured by TOPEX is analyzed in the tropical Pacific Ocean by way of assimilation into a wind-driven, reduced-gravity, shallow water model using an approximate Kalman filter and smoother. The analysis results in an optimal fit of the dynamic model to the observations, providing it dynamically consistent interpolation of sea level and estimation of the circulation. Nearly 80% of the expected signal variance is accounted for by the model within 20 deg of the equator, and estimation uncertainty is substantially reduced by the voluminous observation. Notable features resolved by the analysis include seasonal changes associated with the North Equatorial Countercurrent and equatorial Kelvin and Rossby waves. Significant discrepancies are also found between the estimate and TOPEX measurements, especially near the eastern boundary. Improvements in the estimate made by the assimilation are validated by comparisons with independent tide gauge and current meter observations. The employed filter and smoother are based on approximately computed estimation error covariance matrices, utilizing a spatial transformation and an symptotic approximation. The analysis demonstrates the practical utility of a quasi-optimal filter and smoother.

  7. Assimilation of TOPEX Sea Level Measurements with a Reduced-Gravity, Shallow Water Model of the Tropical Pacific Ocean

    NASA Technical Reports Server (NTRS)

    Fukumori, Ichiro

    1995-01-01

    Sea surface height variability measured by TOPEX is analyzed in the tropical Pacific Ocean by way of assimilation into a wind-driven, reduced-gravity, shallow water model using an approximate Kalman filter and smoother. The analysis results in an optimal fit of the dynamic model to the observations, providing it dynamically consistent interpolation of sea level and estimation of the circulation. Nearly 80% of the expected signal variance is accounted for by the model within 20 deg of the equator, and estimation uncertainty is substantially reduced by the voluminous observation. Notable features resolved by the analysis include seasonal changes associated with the North Equatorial Countercurrent and equatorial Kelvin and Rossby waves. Significant discrepancies are also found between the estimate and TOPEX measurements, especially near the eastern boundary. Improvements in the estimate made by the assimilation are validated by comparisons with independent tide gauge and current meter observations. The employed filter and smoother are based on approximately computed estimation error covariance matrices, utilizing a spatial transformation and an symptotic approximation. The analysis demonstrates the practical utility of a quasi-optimal filter and smoother.

  8. WRI 50: Strategies for Cooling Electric Generating Facilities Utilizing Mine Water

    SciTech Connect

    Joseph J. Donovan; Brenden Duffy; Bruce R. Leavitt; James Stiles; Tamara Vandivort; Paul Ziemkiewicz

    2004-11-01

    Power generation and water consumption are inextricably linked. Because of this relationship DOE/NETL has funded a competitive research and development initiative to address this relationship. This report is part of that initiative and is in response to DOE/NETL solicitation DE-PS26-03NT41719-0. Thermal electric power generation requires large volumes of water to cool spent steam at the end of the turbine cycle. The required volumes are such that new plant siting is increasingly dependent on the availability of cooling circuit water. Even in the eastern U.S., large rivers such as the Monongahela may no longer be able to support additional, large power stations due to subscription of flow to existing plants, industrial, municipal and navigational requirements. Earlier studies conducted by West Virginia University (WV 132, WV 173 phase I, WV 173 Phase II, WV 173 Phase III, and WV 173 Phase IV in review) have identified that a large potential water resource resides in flooded, abandoned coal mines in the Pittsburgh Coal Basin, and likely elsewhere in the region and nation. This study evaluates the technical and economic potential of the Pittsburgh Coal Basin water source to supply new power plants with cooling water. Two approaches for supplying new power plants were evaluated. Type A employs mine water in conventional, evaporative cooling towers. Type B utilizes earth-coupled cooling with flooded underground mines as the principal heat sink for the power plant reject heat load. Existing mine discharges in the Pittsburgh Coal Basin were evaluated for flow and water quality. Based on this analysis, eight sites were identified where mine water could supply cooling water to a power plant. Three of these sites were employed for pre-engineering design and cost analysis of a Type A water supply system, including mine water collection, treatment, and delivery. This method was also applied to a ''base case'' river-source power plant, for comparison. Mine-water system cost

  9. Releases from the cooling water system in the Waste Tank Farm

    SciTech Connect

    Perkins, W.C.; Lux, C.R.

    1991-12-31

    On September 12, 1991, a cooling-water header broke in the H-Area Waste Tank farm, at the Savannah River Site, releasing contaminated water down a storm sewer that drains to the creek. A copy of the Occurrence Report is attached. As part of the follow-up on this incident, the NPSR Section was asked by Waste Management Technology to perform a probabilistic analysis of the following cases: (1) A large break in the header combined with a large break in a cooling coil inside a waste tank. (2) A large break in the header combined with a leak in a cooling coil inside a waste tank. (3) A large break in the header combined with a very small leak in a cooling coil inside a waste tank. This report documents the results of the analysis of these cases.

  10. Releases from the cooling water system in the Waste Tank Farm

    SciTech Connect

    Perkins, W.C.; Lux, C.R.

    1991-01-01

    On September 12, 1991, a cooling-water header broke in the H-Area Waste Tank farm, at the Savannah River Site, releasing contaminated water down a storm sewer that drains to the creek. A copy of the Occurrence Report is attached. As part of the follow-up on this incident, the NPSR Section was asked by Waste Management Technology to perform a probabilistic analysis of the following cases: (1) A large break in the header combined with a large break in a cooling coil inside a waste tank. (2) A large break in the header combined with a leak in a cooling coil inside a waste tank. (3) A large break in the header combined with a very small leak in a cooling coil inside a waste tank. This report documents the results of the analysis of these cases.

  11. Cool-down and frozen start-up behavior of a grooved water heat pipe

    NASA Technical Reports Server (NTRS)

    Jang, Jong Hoon

    1990-01-01

    A grooved water heat pipe was tested to study its characteristics during the cool-down and start-up periods. The water heat pipe was cooled down from the ambient temperature to below the freezing temperature of water. During the cool-down, isothermal conditions were maintained at the evaporator and adiabatic sections until the working fluid was frozen. When water was frozen along the entire heat pipe, the heat pipe was rendered inactive. The start-up of the heat pipe from this state was studied under several different operating conditions. The results show the existence of large temperature gradients between the evaporator and the condenser, and the moving of the melting front of the working fluid along the heat pipe. Successful start-up was achieved for some test cases using partial gravity assist. The start-up behavior depended largely on the operating conditions.

  12. Comprehensive cooling water study annual report. Volume II: introduction and site description, Savannah River Plant

    SciTech Connect

    Gladden, J.B.; Lower, M.W.; Mackey, H.E.; Specht, W.L.; Wilde, E.W.

    1985-07-01

    The Comprehensive Cooling Water Study was initiated in 1983 to evaluate the environmental effecs of the intake and release of cooling water on the structure and function of aquatic ecosystems at the Savannah River Plant. This report presents the results from the first year of the two year study and also summarizes results from previous studies on aquatic ecosystems of the Savannah River Plant. Five major program elements are addressed: water quality, radionuclide and heavy metal transport, wetlands ecology, aquatic ecology, and endangered species. 63 refs., 13 figs., 7 tabs.

  13. Comprehensive Cooling Water Study: Volume 7, Ecology of Par Pond, Savannah River Plant: Final report

    SciTech Connect

    Wilde, E.W.

    1987-10-01

    The Comprehensive Cooling Water Study (CCWS) was initiated in 1983 to evaluate the environmental effects of the intake and release of cooling water on the structure and function of aquatic ecosystems at the Savannah River Plant. The initial report (Gladden et al., 1985) described the results from the first year of the study. This document is the final report and concludes the program. The report comprises eight volumes. The first is a summary of environmental effects. The other seven volumes address water quality, radionuclide and heavy metal transport, wetlands, aquatic ecology, Federally endangered species, ecology of Par Pond, and waterfowl. 222 refs., 31 figs., 67 tabs.

  14. PH adjustment of power plant cooling water with flue gas/fly ash

    DOEpatents

    Brady, Patrick V.; Krumhansl, James L.

    2015-09-22

    A system including a vessel including a heat source and a flue; a turbine; a condenser; a fluid conduit circuit disposed between the vessel, the turbine and the condenser; and a diverter coupled to the flue to direct a portion of an exhaust from the flue to contact with a cooling medium for the condenser water. A method including diverting a portion of exhaust from a flue of a vessel; modifying the pH of a cooling medium for a condenser with the portion of exhaust; and condensing heated fluid from the vessel with the pH modified cooling medium.

  15. CALL-FOR-ABSTRACTS: SYMPOSIUM ON TECHNOLOGIES FOR PROTECTING AQUATIC ORGANISMS FROM COOLING WATER INTAKE STRUCTURES

    EPA Science Inventory

    Section 316(b) of the Clean Water Act requires EPA to ensure that the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impacts. In February 2002, the EPA approved a proposed ...

  16. CALL-FOR-ABSTRACTS: SYMPOSIUM ON TECHNOLOGIES FOR PROTECTING AQUATIC ORGANISMS FROM COOLING WATER INTAKE STRUCTURES

    EPA Science Inventory

    Section 316(b) of the Clean Water Act requires EPA to ensure that the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impacts. In February 2002, the EPA approved a proposed ...

  17. 40 CFR 463.10 - Applicability; description of the contact cooling and heating water subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PLASTICS MOLDING AND... cooling and heating water subcategory are processes where process water comes in contact with plastic materials or plastic products for the purpose of heat transfer during plastics molding and forming....

  18. Selection of Cooling Water Treatment at Military Installations to Prevent Scaling and Corrosion.

    DTIC Science & Technology

    1980-06-01

    only. For cooling towers of 20 to 50 tons (18.1 to 45.3 MT), 3 cycles of concentration with sodium hexametaphos- phate (0.5 to 5 ppm) should be used...Liquid Cooling Tower Treatment Blend M mainly of adding sodium zeolite softening or blended (item 8), consists of 9.5 percent disphosphonic acid...2.8 percent sodium pyrophosphate (as Item 10), the harder waters. Recently, superior organic scale 1.4 percent causticized mercaptobenzothiazole, and

  19. Measured performance of a 3 ton LiBr absorption water chiller and its effect on cooling system operation

    NASA Technical Reports Server (NTRS)

    Namkoong, D.

    1976-01-01

    A three ton lithium bromide absorption water chiller was tested for a number of conditions involving hot water input, chilled water, and the cooling water. The primary influences on chiller capacity were the hot water inlet temperature and the cooling water inlet temperature. One combination of these two parameters extended the output to as much as 125% of design capacity, but no combination could lower the capacity to below 60% of design. A cooling system was conceptually designed so that it could provide several modes of operation. Such flexibility is needed for any solar cooling system to be able to accommodate the varying solar energy collection and the varying building demand. It was concluded that a three-ton absorption water chiller with the kind of performance that was measured can be incorporated into a cooling system such as that proposed, to provide efficient cooling over the specified ranges of operating conditions.

  20. Measured performance of a 3-ton LiBr absorption water chiller and its effect on cooling system operation

    NASA Technical Reports Server (NTRS)

    Namkoong, D.

    1976-01-01

    A 3-ton lithium bromide absorption water chiller was tested for a number of conditions involving hot-water input, chilled water, and the cooling water. The primary influences on chiller capacity were the hot water inlet temperature and the cooling water inlet temperature. One combination of these two parameters extended the output to as much as 125% of design capacity, but no combination could lower the capacity to below 60% of design. A cooling system was conceptually designed so that it could provide several modes of operation. Such flexibility is needed for any solar cooling system to be able to accommodate the varying solar energy collection and the varying building demand. It is concluded that a 3-ton absorption water chiller with the kind of performance that was measured can be incorporated into a cooling system such as that proposed, to provide efficient cooling over the specified ranges of operating conditions.

  1. Effect of Water-Cooled Nd:YAG Laser on Dentinal Tubule Occlusion In Vitro.

    PubMed

    Xiao, Shimeng; Liang, Kunneng; Liu, Hongling; Zhang, Manling; Yang, Heng; Guo, Shujuan; Ding, Yi

    2017-02-01

    The objective of this study was to investigate the effect of a new water-cooled Nd:YAG laser on dentinal tubule occlusion. The effect of water-cooled Nd:YAG laser on dentinal tubule occlusion has not been reported. Acid-etched dentin samples were randomly divided into three groups: (1) dentin control, (2) dentin treated by Nd:YAG laser, (3) dentin treated by water-cooled Nd:YAG laser. After laser irradiation, half of the samples were immersed in a 6 wt% citric acid (pH 1.5) solution for 1 min to evaluate the acid resistance. The morphologies of dentin surfaces were characterized by scanning electron microscopy. The number and diameters of the open dentinal tubules were analyzed by one-way and two-way analyses of variance. Both the Nd:YAG laser and water-cooled Nd:YAG laser melted the superficial layer of dentin, which caused dentinal tubule occlusion in most areas and diameter reduction of the rest open tubules. Microcracks on the dentin surface were only observed in the Nd:YAG laser group. The tubule occlusion induced by the two lasers showed a good acid resistance. The effect of water-cooled Nd:YAG laser on dentinal tubule occlusion is similar to that of the Nd:YAG laser. The dentinal tubule occlusion induced by the two lasers could resist acid challenge to some extent.

  2. [Influencing Factors of Assimilable Organic Carbon (AOC) Formation in Drinking Water During Ozonation Process].

    PubMed

    Dong, Bing-zhi; Zhang, Jia-li; He, Chang

    2016-05-15

    The influences of ozone dosage, pH and ionic strength on the formation of Assimilable Organic Carbon (AOC) during ozonation were investigated. The result demonstrated that within the range of 1-5 mg · L⁻¹ O₃, the formation of AOC increased with increasing ozone dosage, but higher ozone dosage (9 mg · L⁻¹) resulted in reduction of AOC formation. AOC formation increased with higher pH but decreased with increasing ionic strength. The result also showed that AOC formation with hydrophobic fraction (HPO) was the most, followed by transphilic fraction (TPI), and charged hydrophilic fraction (CHPI), while neutral hydrophilic fraction (NHPI) was the least. It was found that AOC formation related closely with SUVA of small molecular weight organics, and the lower SUVA produced more AOC.

  3. Responses of Leaf-level Carbon Assimilation and Transpiration to Root-zone Water Potential Changes in a Subtropical Tree Species

    NASA Astrophysics Data System (ADS)

    Cicheng, Z.; Guan, H.; Han, G.; Zhang, X.

    2013-12-01

    Photosynthetic carbon assimilation in terrestrial ecosystems significantly contributes to global carbon balance in the atmosphere. While vegetation photosynthesizes to fix CO2, it simultaneously transpires H2O. These two interdependent processes are regulated by leaf stomata which are sensitive to environmental conditions (such as root zone soil moisture). Knowledge of the responses of leaf-level transpiration and carbon assimilation to a change of root-zone soil moisture condition is important to understand how these processes influence water balance and carbon sequestration in terrestrial ecosystems, and to understand the capacity of trees to cope with future climate changes.We will present the results of a one-year observational study on a subtropical evergreen broadleaf tree species (Osmanthus fragrans) in the central south China. The observations were carried out on two 8-year Osmanthus fragrans trees in a plantation site from 1 Sep, 2012 to 31 Aug, 2013. A portable infrared gas exchange analyzer (Li-6400, Li-COR, Inc., Lincoln, Nebraska, USA) was used to measure leaf photosynthesis and leaf transpiration on clear days. Root zone soil water potential was estimated from predawn stem water potential using stem psychrometers (ICT, Australia). Sap flow and micrometeorological data were also collected. The results show that the average leaf carbon assimilation rate at light saturation decreases quickly with the root zone water potential from 0 to -1 MPa, and slowly after the root zone water potential falls below -1 MPa. The average leaf transpiration at light saturation shows a similar pattern. Leaf-level water use efficiency increases slowly with a decrease of root-zone water potential from 0 to -1 MPa, and keeps constant when the root zone gets drier. This relationship provides a potential to estimate whole-tree carbon assimilation from sap flow measurements. Leaf assimilation rates at light saturation in early morning vs. root-zone water potential for Osmanthus

  4. Estimating Snow Water Storage in North America Using CLM4, DART, and Snow Radiance Data Assimilation

    NASA Technical Reports Server (NTRS)

    Kwon, Yonghwan; Yang, Zong-Liang; Zhao, Long; Hoar, Timothy J.; Toure, Ally M.; Rodell, Matthew

    2016-01-01

    This paper addresses continental-scale snow estimates in North America using a recently developed snow radiance assimilation (RA) system. A series of RA experiments with the ensemble adjustment Kalman filter are conducted by assimilating the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) brightness temperature T(sub B) at 18.7- and 36.5-GHz vertical polarization channels. The overall RA performance in estimating snow depth for North America is improved by simultaneously updating the Community Land Model, version 4 (CLM4), snow/soil states and radiative transfer model (RTM) parameters involved in predicting T(sub B) based on their correlations with the prior T(sub B) (i.e., rule-based RA), although degradations are also observed. The RA system exhibits a more mixed performance for snow cover fraction estimates. Compared to the open-loop run (0.171m RMSE), the overall snow depth estimates are improved by 1.6% (0.168m RMSE) in the rule-based RA whereas the default RA (without a rule) results in a degradation of 3.6% (0.177mRMSE). Significant improvement of the snow depth estimates in the rule-based RA as observed for tundra snow class (11.5%, p < 0.05) and bare soil land-cover type (13.5%, p < 0.05). However, the overall improvement is not significant (p = 0.135) because snow estimates are degraded or marginally improved for other snow classes and land covers, especially the taiga snow class and forest land cover (7.1% and 7.3% degradations, respectively). The current RA system needs to be further refined to enhance snow estimates for various snow types and forested regions.

  5. Estimating Snow Water Storage in North America Using CLM4, DART, and Snow Radiance Data Assimilation

    NASA Technical Reports Server (NTRS)

    Kwon, Yonghwan; Yang, Zong-Liang; Zhao, Long; Hoar, Timothy J.; Toure, Ally M.; Rodell, Matthew

    2016-01-01

    This paper addresses continental-scale snow estimates in North America using a recently developed snow radiance assimilation (RA) system. A series of RA experiments with the ensemble adjustment Kalman filter are conducted by assimilating the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) brightness temperature T(sub B) at 18.7- and 36.5-GHz vertical polarization channels. The overall RA performance in estimating snow depth for North America is improved by simultaneously updating the Community Land Model, version 4 (CLM4), snow/soil states and radiative transfer model (RTM) parameters involved in predicting T(sub B) based on their correlations with the prior T(sub B) (i.e., rule-based RA), although degradations are also observed. The RA system exhibits a more mixed performance for snow cover fraction estimates. Compared to the open-loop run (0.171m RMSE), the overall snow depth estimates are improved by 1.6% (0.168m RMSE) in the rule-based RA whereas the default RA (without a rule) results in a degradation of 3.6% (0.177mRMSE). Significant improvement of the snow depth estimates in the rule-based RA as observed for tundra snow class (11.5%, p < 0.05) and bare soil land-cover type (13.5%, p < 0.05). However, the overall improvement is not significant (p = 0.135) because snow estimates are degraded or marginally improved for other snow classes and land covers, especially the taiga snow class and forest land cover (7.1% and 7.3% degradations, respectively). The current RA system needs to be further refined to enhance snow estimates for various snow types and forested regions.

  6. Isolation of Legionella species/serogroups from water cooling systems compared with potable water systems in Spanish healthcare facilities.

    PubMed

    Rivera, J-M; Aguilar, L; Granizo, J J; Vos-Arenilla, A; Giménez, M-J; Aguiar, J-M; Prieto, J

    2007-12-01

    Surveillance of Legionella spp. in hospital water systems was performed in forty-four inpatient healthcare facilities in Spain during 2005-2006. A total of 2,341 samples were collected: 470 from cooling systems (cooling towers) and 1,871 from potable water systems. The latter included 211 from cold-water tanks and 260 from hot-water tanks, totalling 471 from central water reservoirs 136 from showers, 1,172 from unfiltered taps and 92 from filtered taps, totalling 1,400 from peripheral points. Temperature, chlorine levels and the presence of Legionella spp. were determined. In all, 373 (15.9%) samples yielded Legionella spp. Significantly higher isolation rates were obtained from cooling towers (23.8%) versus cold- and hot-water tanks (approximately 4.7%), due to the significantly higher number of samples positive for serogroup 1 (19.4 vs 0.9-3.5%). In potable water systems, no differences were found between central water tanks and showers, but significant differences in isolation rates between central water tanks and unfiltered taps were observed (4.7 vs 19.6%) due to differences in non-serogroup 1 L. pneumophila. Filters significantly decreased isolation rates of these serotypes (11 vs 0%). Some seasonal differences were noted, with higher isolation rates in summer for legionella serogroup 1 in cooling systems and for L. pneumophila serogroups 2-14 in potable water systems. In regression models, higher temperatures were associated with colonisation in cooling systems, while lower chlorine levels were associated with colonisation in potable water systems.

  7. The microscale cooling effects of water sensitive urban design and irrigation in a suburban environment

    NASA Astrophysics Data System (ADS)

    Broadbent, Ashley M.; Coutts, Andrew M.; Tapper, Nigel J.; Demuzere, Matthias; Beringer, Jason

    2017-09-01

    Prolonged drought has threatened traditional potable urban water supplies in Australian cities, reducing capability to adapt to climate change and mitigate against extreme. Integrated urban water management (IUWM) approaches, such as water sensitive urban design (WSUD), reduce the reliance on centralised potable water supply systems and provide a means for retaining water in the urban environment through stormwater harvesting and reuse. This study examines the potential for WSUD to provide cooling benefits and reduce human exposure and heat stress and thermal discomfort. A high-resolution observational field campaign, measuring surface level microclimate variables and remotely sensed land surface characteristics, was conducted in a mixed residential suburb containing WSUD in Adelaide, South Australia. Clear evidence was found that WSUD features and irrigation can reduce surface temperature (T s) and air temperature (T a) and improve human thermal comfort (HTC) in urban environments. The average 3 pm T a near water bodies was found to be up to 1.8 °C cooler than the domain maximum. Cooling was broadly observed in the area 50 m downwind of lakes and wetlands. Design and placement of water bodies were found to affect their cooling effectiveness. HTC was improved by proximity to WSUD features, but shading and ventilation were also effective at improving thermal comfort. This study demonstrates that WSUD can be used to cool urban microclimates, while simultaneously achieving other environmental benefits, such as improved stream ecology and flood mitigation.

  8. Geographic, technologic, and economic analysis of using reclaimed water for thermoelectric power plant cooling.

    PubMed

    Stillwell, Ashlynn S; Webber, Michael E

    2014-04-15

    Use of reclaimed water-municipal wastewater treatment plant effluent-in nonpotable applications can be a sustainable and efficient water management strategy. One such nonpotable application is at thermoelectric power plants since these facilities require cooling, often using large volumes of freshwater. To evaluate the geographic, technologic, and economic feasibility of using reclaimed water to cool thermoelectric power plants, we developed a spatially resolved model of existing power plants. Our model integrates data on power plant and municipal wastewater treatment plant operations into a combined geographic information systems and optimization approach to evaluate the feasibility of cooling system retrofits. We applied this broadly applicable methodology to 125 power plants in Texas as a test case. Results show that sufficient reclaimed water resources exist within 25 miles of 92 power plants (representing 61% of capacity and 50% of generation in our sample), with most of these facilities meeting both short-term and long-term water conservation cost goals. This retrofit analysis indicates that reclaimed water could be a suitable cooling water source for thermoelectric power plants, thereby mitigating some of the freshwater impacts of electricity generation.

  9. Zirconium carbide coating for corium experiments related to water-cooled and sodium-cooled reactors

    NASA Astrophysics Data System (ADS)

    Plevacova, K.; Journeau, C.; Piluso, P.; Zhdanov, V.; Baklanov, V.; Poirier, J.

    2011-07-01

    Since the TMI and Chernobyl accidents the risk of nuclear severe accident is intensively studied for existing and future reactors. In case of a core melt-down accident in a nuclear reactor, a complex melt, called corium, forms. To be able to perform experiments with prototypic corium materials at high temperature, a coating which resists to different corium melts related to Generation I and II Water Reactors and Generation IV sodium fast reactor was researched in our experimental platforms both in IAE NNC in Kazakhstan and in CEA in France. Zirconium carbide was selected as protective coating for graphite crucibles used in our induction furnaces: VCG-135 and VITI. The method of coating application, called reactive wetting, was developed. Zirconium carbide revealed to resist well to the (U x, Zr y)O 2-z water reactor corium. It has also the advantage not to bring new elements to this chemical system. The coating was then tested with sodium fast reactor corium melts containing steel or absorbers. Undesirable interactions were observed between the coating and these materials, leading to the carburization of the corium ingots. Concerning the resistance of the coating to oxide melts without ZrO 2, the zirconium carbide coating keeps its role of protective barrier with UO 2-Al 2O 3 below 2000 °C but does not resist to a UO 2-Eu 2O 3 mixture.

  10. Assimilation Yesterday, Today and Tomorrow

    NASA Astrophysics Data System (ADS)

    Wolff, J. A.; Ramos, F. C.

    2002-12-01

    N.L. Bowen pointed out that the effect of assimilating fusible rock into a cooling magma is to increase the volume of residual liquids, not change the cotectic relations that govern the compositions of those liquids. Accurate estimation of volumes of initial and residual liquids in evolving magmatic systems remains impossible, and petrologists interested in assimilation have tended to focus instead on identifying passive chemical tracers of crustal input into volcanic systems, especially during the last ~35 years in which high-quality trace element and isotope data have been available. Much of the motivation for these studies has arisen from the desire to use basaltic magmas as probes of mantle geochemistry, which relies on stripping from the basalt any chemical changes resulting from interaction between mantle-derived magma and crust. Despite the impressive array of high quality whole rock chemical data (typically concentrations of ~40 elements, and isotopic ratios from any or all of the systems Rb/Sr, Sm/Nd, U/Th/Pb, Lu/Hf, Re/Os, O and U/Th) applied to individual cases, two different investigators can interpret the same data set to arrive at highly disparate conclusions about the amount of crustal assimilation involved in the petrogenesis of, say, lavas from a continental volcanic field. In part, this situation arises from a decoupling between the sophistication of the chemical data and the naiveté with which we view processes of magma transport and storage. Two current developments promise to greatly improve our understanding of assimilation over the 25 years until the centenary celebrations of the publication of "The Evolution of the Igneous Rocks". First, models such as energy-constrained assimilation-fractional crystallization [1] that link a physical (in this case, thermodynamic) description of a magmatic system with the evolution of trace element abundances and isotopic ratios are revealing the wide range of results that arise from interaction of basaltic

  11. Nitrogen removal from aquaculture pond water by heterotrophic nitrogen assimilation in lab-scale sequencing batch reactors.

    PubMed

    De Schryver, Peter; Verstraete, Willy

    2009-02-01

    The potential use of sequencing batch reactors (SBRs) as an alternative bio-flocs technology (BFT) approach in aquaculture was explored. One SBR was dosed with glycerol and one with acetate for the decrease of the nitrogen concentration in simulated aquaculture water by microbial assimilation. At an optimal C/N ratio between 10 and 15, the nitrogen removal efficiency reached up to 98% (=110 mg N L(-1) reactor day(-1)) for both SBRs. The estimated biomass productivity reached 0.62-0.94 g C L(-1)r eactor day(-1) for the glycerol SBR and 0.54-0.82 g C L(-1) reactor day(-1) for the acetate SBR. The floc protein content, indicating biomass quality, reached up to 57% if grown on glycerol. With acetate, it attained a value of 61%. The highest average poly-beta-hydroxybutyrate (PHB) content was 16% on a dry weight basis for the acetate biomass.

  12. Optimization of Cooling Water Flow Rate in Nuclear and Thermal Power Plants Based on a Mathematical Model of Cooling Systems{sup 1}

    SciTech Connect

    Murav’ev, V. P. Kochetkov, A. V.; Glazova, E. G.

    2016-09-15

    A mathematical model and algorithms are proposed for automatic calculation of the optimum flow rate of cooling water in nuclear and thermal power plants with cooling systems of arbitrary complexity. An unlimited number of configuration and design variants are assumed with the possibility of obtaining a result for any computational time interval, from monthly to hourly. The structural solutions corresponding to an optimum cooling water flow rate can be used for subsequent engineering-economic evaluation of the best cooling system variant. The computerized mathematical model and algorithms make it possible to determine the availability and degree of structural changes for the cooling system in all stages of the life cycle of a plant.

  13. Correction analysis for a supersonic water cooled total temperature probe tested to 1370 K

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas T.; Seiner, John M.

    1991-01-01

    The authors address the thermal analysis of a water cooled supersonic total temperature probe tested in a Mach 2 flow, up to 1366 K total temperature. The goal of this experiment was the determination of high-temperature supersonic jet mean flow temperatures. An 8.99 cm exit diameter water cooled nozzle was used in the tests. It was designed for exit Mach 2 at 1366 K exit total temperature. Data along the jet centerline were obtained for total temperatures of 755 K, 1089 K, and 1366 K. The data from the total temperature probe were affected by the water coolant. The probe was tested through a range of temperatures between 755 K and 1366 K with and without the cooling system turned on. The results were used to develop a relationship between the indicated thermocouple bead temperature and the freestream total temperature. The analysis and calculated temperatures are presented.

  14. Correction analysis for a supersonic water cooled total temperature probe tested to 1370 K

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas T.; Seiner, John M.

    1991-01-01

    The authors address the thermal analysis of a water cooled supersonic total temperature probe tested in a Mach 2 flow, up to 1366 K total temperature. The goal of this experiment was the determination of high-temperature supersonic jet mean flow temperatures. An 8.99 cm exit diameter water cooled nozzle was used in the tests. It was designed for exit Mach 2 at 1366 K exit total temperature. Data along the jet centerline were obtained for total temperatures of 755 K, 1089 K, and 1366 K. The data from the total temperature probe were affected by the water coolant. The probe was tested through a range of temperatures between 755 K and 1366 K with and without the cooling system turned on. The results were used to develop a relationship between the indicated thermocouple bead temperature and the freestream total temperature. The analysis and calculated temperatures are presented.

  15. New Mexico cloud super cooled liquid water survey final report 2009.

    SciTech Connect

    Beavis, Nick; Roskovensky, John K.; Ivey, Mark D.

    2010-02-01

    Los Alamos and Sandia National Laboratories are partners in an effort to survey the super-cooled liquid water in clouds over the state of New Mexico in a project sponsored by the New Mexico Small Business Assistance Program. This report summarizes the scientific work performed at Sandia National Laboratories during the 2009. In this second year of the project a practical methodology for estimating cloud super-cooled liquid water was created. This was accomplished through the analysis of certain MODIS sensor satellite derived cloud products and vetted parameterizations techniques. A software code was developed to analyze multiple cases automatically. The eighty-one storm events identified in the previous year effort from 2006-2007 were again the focus. Six derived MODIS products were obtained first through careful MODIS image evaluation. Both cloud and clear-sky properties from this dataset were determined over New Mexico. Sensitivity studies were performed that identified the parameters which most influenced the estimation of cloud super-cooled liquid water. Limited validation was undertaken to ensure the soundness of the cloud super-cooled estimates. Finally, a path forward was formulized to insure the successful completion of the initial scientific goals which include analyzing different of annual datasets, validation of the developed algorithm, and the creation of a user-friendly and interactive tool for estimating cloud super-cooled liquid water.

  16. Water cooling system leak proofing strategy for the Plasma Couette Experiment Upgrade (PCX-U)

    NASA Astrophysics Data System (ADS)

    Clark, Mike; Flanagan, Ken; Hernandez, Wilson; Jaeger, Austin; Laufman-Wollitzer, Lauren; Nikolau, Ethan; Tabbutt, Megan; Waleffe, Roger; Wallace, John; Xu, Yufan; Forest, Cary

    2016-10-01

    An improved system for water cooling several experimental components has been installed for the Plasma Couette Experiment Upgrade (PCX-U). The most important aspect of the upgrade was to cool the new SmCo permanent magnet cage array. Many methods of connecting water cooling pipes, tubes, and fittings were employed balancing several factors. These factors included ease of assembly/disassembly, reliability, operating pressure, operating temperature, chemical reactivity, and cost. The actions taken to develop the water cooling system will be discussed and illustrated. A focus will be made on sealing cooling water leaks from the inside out on small diameter metal passages (including extrusions, tubing, and fittings). These passages were located inside a vacuum environment, and only the ends of each passage were accessible to do the work. The vacuum vessel of PCX-U is a 1 meter diameter, 1 meter tall cylinder comprised of 0.25'' thick stainless steel. PCX-U has one removable end. Rings of SmCo magnets attached to a removable frame create a cusp field to contain the plasma and provide a resonance surface for the RF. This work is supported by the NSF.

  17. Using containment analysis to improve component cooling water heat exchanger limits

    SciTech Connect

    Da Silva, H.C.; Tajbakhsh, A.

    1995-12-31

    The Comanche Peak Steam Electric Station design requires that exit temperatures from the Component Cooling Water Heat Exchanger remain below 330.37 K during the Emergency Core Cooling System recirculation stage, following a hypothetical Loss of Coolant Accident (LOCA). Due to measurements indicating a higher than expected combination of: (a) high fouling factor in the Component Cooling Water Heat Exchanger with (b) high ultimate heat sink temperatures, that might lead to temperatures in excess of the 330.37 K limit, if a LOCA were to occur, TUElectric adjusted key flow rates in the Component Cooling Water network. This solution could only be implemented with improvements to the containment analysis methodology of record. The new method builds upon the CONTEMPT-LT/028 code by: (a) coupling the long term post-LOCA thermohydraulics with a more detailed analytical model for the complex Component Cooling Water Heat Exchanger network and (b) changing the way mass and energy releases are calculated after core reflood and steam generator energy is dumped to the containment. In addition, a simple code to calculate normal cooldowns was developed to confirm RHR design bases were met with the improved limits.

  18. Ice water submersion for rapid cooling in severe drug-induced hyperthermia

    PubMed Central

    Laskowski, Larissa K.; Landry, Adaira; Vassallo, Susi U.; Hoffman, Robert S.

    2015-01-01

    Context The optimal method of cooling hyperthermic patients is controversial. Although controlled data support ice water submersion, many authorities recommend a mist and fan technique. We report two patients with drug-induced hyperthermia, to demonstrate the rapid cooing rates of ice water submersion. Case details Case 1. A 27-year-old man presented with a sympathomimetic toxic syndrome and a core temperature of 41.4°C after ingesting 4-fluoroamphetamine. He was submerged in ice water and his core temperature fell to 38°C within 18 minutes (a mean cooling rate of 0.18°C/min). His vital signs stabilized, his mental status improved and he left on hospital day 2. Case 2. A 32-year-old man with a sympathomimetic toxic syndrome after cocaine use was transported in a body bag and arrived with a core temperature of 44.4°C. He was intubated, sedated with IV benzodiazepines, and submerged in ice water. After 20 minutes his temperature fell to 38.8°C (a cooling rate of 0.28°C/min). He was extubated the following day, and discharged on day 10. Discussion In these two cases, cooling rates exceeded those reported for mist and fan technique. Since the priority in hyperthermia is rapid cooling, clinical data need to be collected to reaffirm the optimal approach. PMID:25695144

  19. Experimental and numerical analysis of the cooling performance of water spraying systems during a fire.

    PubMed

    Chen, YaoHan; Su, ChungHwei; Tseng, JoMing; Li, WunJie

    2015-01-01

    The water spray systems are effective protection systems in the confined or unconfined spaces to avoid the damage to building structures since the high temperature when fires occur. NFPA 15 and 502 have suggested respectively that the factories or vehicle tunnels install water spray systems to protect the machinery and structures. This study discussed the cooling effect of water spray systems in experimental and numerical analyses. The actual combustion of woods were compared with the numerical simulations. The results showed that although the flame continued, the cooling effects by water spraying process within 120 seconds were obvious. The results also indicated that the simulation results of the fifth version Fire Dynamics Simulator (FDS) overestimated the space temperature before water spraying in the case of the same water spray system.

  20. Experimental and Numerical Analysis of the Cooling Performance of Water Spraying Systems during a Fire

    PubMed Central

    Chen, YaoHan; Su, ChungHwei; Tseng, JoMing; Li, WunJie

    2015-01-01

    The water spray systems are effective protection systems in the confined or unconfined spaces to avoid the damage to building structures since the high temperature when fires occur. NFPA 15 and 502 have suggested respectively that the factories or vehicle tunnels install water spray systems to protect the machinery and structures. This study discussed the cooling effect of water spray systems in experimental and numerical analyses. The actual combustion of woods were compared with the numerical simulations. The results showed that although the flame continued, the cooling effects by water spraying process within 120 seconds were obvious. The results also indicated that the simulation results of the fifth version Fire Dynamics Simulator (FDS) overestimated the space temperature before water spraying in the case of the same water spray system. PMID:25723519

  1. Heat exchanger and water tank arrangement for passive cooling system

    DOEpatents

    Gillett, James E.; Johnson, F. Thomas; Orr, Richard S.; Schulz, Terry L.

    1993-01-01

    A water storage tank in the coolant water loop of a nuclear reactor contains a tubular heat exchanger. The heat exchanger has tubesheets mounted to the tank connections so that the tubesheets and tubes may be readily inspected and repaired. Preferably, the tubes extend from the tubesheets on a square pitch and then on a rectangular pitch therebetween. Also, the heat exchanger is supported by a frame so that the tank wall is not required to support all of its weight.

  2. 78 FR 64029 - Cost-Benefit Analysis for Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ... COMMISSION Cost-Benefit Analysis for Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors AGENCY... Systems for Light-Water-Cooled Nuclear Power Reactors,'' in which the NRC made editorial corrections and... analysis for liquid and gaseous radwaste system components for light water nuclear power...

  3. Water cooling system using a piezoelectrically actuated flow pump for a medical headlight system

    NASA Astrophysics Data System (ADS)

    Pires, Rogério F.; Vatanabe, Sandro L.; de Oliveira, Amaury R.; Nakasone, Paulo H.; Silva, Emílio C.

    2007-04-01

    The microchips inside modern electronic equipment generate heat and demand, each day, the use of more advanced cooling techniques as water cooling systems, for instance. These systems combined with piezoelectric flow pumps present some advantages such as higher thermal capacity, lower noise generation and miniaturization potential. The present work aims at the development of a water cooling system based on a piezoelectric flow pump for a head light system based on LEDs. The cooling system development consists in design, manufacturing and experimental characterization steps. In the design step, computational models of the pump, as well as the heat exchanger were built to perform sensitivity studies using ANSYS finite element software. This allowed us to achieve desired flow and heat exchange rates by varying the frequency and amplitude of the applied voltage. Other activities included the design of the heat exchanger and the dissipation module. The experimental tests of the cooling system consisted in measuring the temperature difference between the heat exchanger inlet and outlet to evaluate its thermal cooling capacity for different values of the flow rate. Comparisons between numerical and experimental results were also made.

  4. Cool water: demonstration of a clean and efficient new coal technology.

    PubMed

    Spencer, D F; Alpert, S B; Gilman, H H

    1986-05-02

    Cool Water, the world's first commercial-scale, integrated coal gasification combined cycle power plant, has been operating successfully since May 1984 near Barstow, California. The 100-megawatt plant, which was completed ahead of schedule and under budget, is probably the cleanest coal-fired power generating facility now in commercial operation. An ongoing demonstration program at Cool Water shows that future baseload power plants that use this technology can be built modularly in increments of a few hundred megawatts and compete economically with much larger, conventional coal-fired power plants equipped for flue gas desulfurization.

  5. Questioning the Mpemba effect: hot water does not cool more quickly than cold

    NASA Astrophysics Data System (ADS)

    Burridge, Henry C.; Linden, Paul F.

    2016-11-01

    The Mpemba effect is the name given to the assertion that it is quicker to cool water to a given temperature when the initial temperature is higher. This assertion seems counter-intuitive and yet references to the effect go back at least to the writings of Aristotle. Indeed, at first thought one might consider the effect to breach fundamental thermodynamic laws, but we show that this is not the case. We go on to examine the available evidence for the Mpemba effect and carry out our own experiments by cooling water in carefully controlled conditions. We conclude, somewhat sadly, that there is no evidence to support meaningful observations of the Mpemba effect.

  6. Questioning the Mpemba effect: hot water does not cool more quickly than cold.

    PubMed

    Burridge, Henry C; Linden, Paul F

    2016-11-24

    The Mpemba effect is the name given to the assertion that it is quicker to cool water to a given temperature when the initial temperature is higher. This assertion seems counter-intuitive and yet references to the effect go back at least to the writings of Aristotle. Indeed, at first thought one might consider the effect to breach fundamental thermodynamic laws, but we show that this is not the case. We go on to examine the available evidence for the Mpemba effect and carry out our own experiments by cooling water in carefully controlled conditions. We conclude, somewhat sadly, that there is no evidence to support meaningful observations of the Mpemba effect.

  7. Heat exchanger and water tank arrangement for passive cooling system

    DOEpatents

    Gillett, J.E.; Johnson, F.T.; Orr, R.S.; Schulz, T.L.

    1993-11-30

    A water storage tank in the coolant water loop of a nuclear reactor contains a tubular heat exchanger. The heat exchanger has tube sheets mounted to the tank connections so that the tube sheets and tubes may be readily inspected and repaired. Preferably, the tubes extend from the tube sheets on a square pitch and then on a rectangular pitch there between. Also, the heat exchanger is supported by a frame so that the tank wall is not required to support all of its weight. 6 figures.

  8. Use of remotely-sensed observations and a data assimilating marine biogeochemical model to determine water quality on the Great Barrier Reef.

    NASA Astrophysics Data System (ADS)

    Baird, Mark; Jones, Emlyn; Wozniak, Monika; Mongin, Mathieu; Skerratt, Jennifer; Margvelashvilli, Nugzar; Wild-Allen, Karen; Robson, Barbara; Rizwi, Farhan; Schroeder, Thomas; Steven, Andy

    2017-04-01

    The health of the Great Barrier Reef is presently assessed using the water column concentration of chlorophyll and suspended solids, and measured light penetration. Quantifying these water column properties over 2,000 km of often cloud-covered, sparsely sampled, and highly variable coastal waters is problematic. To provide the best estimate of water quality, we assimilating satellite remote-sensing reflectance (the ratio of water-leaving radiance versus water-entering irradiance) using an in-water optical model to produce an equivalent simulated remote-sensing reflectance, and calculate the mis-match between the observed and simulated quantities to constrain a complex biogeochemical model (eReefs) with a Deterministic Ensemble Kalman Filter (DEnKF). We compare the water quality properties of the data assimilating model with in-situ observations, as well as with withheld remote-sensed observations. As a final step, we consider whether withheld observations can be combined with the data-assimilation generated chlorophyll fields to provide the best estimate of the chlorophyll concentration given all the available information.

  9. Numerical analysis on the beam quality improvements of high power chemical laser system with water cooled mirrors

    NASA Astrophysics Data System (ADS)

    Han, Kai; Li, Bin; Xu, Xiao-jun

    2011-06-01

    Chemical laser is one of the most widely used high power infrared sources. Thermal deformation of mirrors in a resonator is a key factor which hinders the improvement of the beam quality in high power chemical lasers, and it has been a matter of the utmost concern in the design of high power chemical laser systems. Water-cooled technique is one of the most widely methods employed in cooling mirrors in high power laser systems. Several kinds of water-cooled mirrors have been studied by researchers in the world. Research teams of the United States and Russia have done a lot of work and their water cooled mirrors behave very well. In China, the study of micro-channel water cooled silicon mirror has been carried out by Cheng Zuhai in detail and the research of water jet cooled mirror has been performed by Li Bin. Both the two types of water cooled mirrors show excellent capabilities in alleviating the thermal deformation of mirrors. However, the issues that how and to what extent the beam quality is improved when the water cooled mirrors are involved have not been analyzed so far. In this paper, through numerical simulations, the beam qualities of linear resonators with various types of water cooled mirrors are analyzed in detail, and the effects of the two types of water cooled mirrors are compared. The thermal distortion of uncooled Si mirrors is characterized by Zernike polynomials and the beam quality is characterized with Strehl ratio, β factor, and M2 factor, which degenerates as the beam oscillates in the distorted resonator. The aberrance of mirrors non-uniformly heated by high energy laser mainly distributes on the low-even-order Zernike polynomials. When the uncooled Si mirrors are replaced by water cooled mirrors, the distortion decreases greatly and the beam quality is improved a lot. Although the performance of the water jet cooled mirror on mitigating distortion is better than the micro-channel water cooled mirror, the resonator made up of two water jet

  10. Global cooling after the eruption of Mount Pinatubo: a test of climate feedback by water vapor.

    PubMed

    Soden, Brian J; Wetherald, Richard T; Stenchikov, Georgiy L; Robock, Alan

    2002-04-26

    The sensitivity of Earth's climate to an external radiative forcing depends critically on the response of water vapor. We use the global cooling and drying of the atmosphere that was observed after the eruption of Mount Pinatubo to test model predictions of the climate feedback from water vapor. Here, we first highlight the success of the model in reproducing the observed drying after the volcanic eruption. Then, by comparing model simulations with and without water vapor feedback, we demonstrate the importance of the atmospheric drying in amplifying the temperature change and show that, without the strong positive feedback from water vapor, the model is unable to reproduce the observed cooling. These results provide quantitative evidence of the reliability of water vapor feedback in current climate models, which is crucial to their use for global warming projections.

  11. State of Fukushima nuclear fuel debris tracked by Cs137 in cooling water.

    PubMed

    Grambow, B; Mostafavi, M

    2014-11-01

    It is still difficult to assess the risk originating from the radioactivity inventory remaining in the damaged Fukushima nuclear reactors. Here we show that cooling water analyses provide a means to assess source terms for potential future releases. Until now already about 34% of the inventories of (137)Cs of three reactors has been released into water. We found that the release rate of (137)Cs has been constant for 2 years at about 1.8% of the inventory per year indicating ongoing dissolution of the fuel debris. Compared to laboratory studies on spent nuclear fuel behavior in water, (137)Cs release rates are on the higher end, caused by the strong radiation field and oxidant production by water radiolysis and by impacts of accessible grain boundaries. It is concluded that radionuclide analyses in cooling water allow tracking of the conditions of the damaged fuel and the associated risks.

  12. An Analysis of Water-Use and Energy-Use Impacts of Residential-Scale Evaporative Cooling Technologies

    NASA Astrophysics Data System (ADS)

    Tajmand, Nasim

    The use of evaporative technology for cooling increases the demand for good water quality (e.g., treated municipal water). The problem is further aggravated in regions with poor water quality and where long-term droughts have decreased water availability. At the same time, energy savings achieved by new evaporative cooling technologies compared to conventional systems have attracted attention in hot and dry climatic zones. In this study, the balance between water consumption and energy savings, and concerns about adequate water quantity and quality, were examined in small-scale evaporative cooling systems. First, the trade-off between water use and energy savings was explored by comparing energy base and cost analyses for three different water resources (tap water, rainwater, and desalination water). Then, one laboratory study to understand the precipitation reaction mechanism in small-scale evaporative cooling systems, plus one field experiment, were conducted to understand water quality impacts and concerns raised by evaporative cooling technologies. The results of the study indicate that evaporative cooling technologies make sense in terms of energy and cost expended in hot and dry climates, even considering the high energy costs of desalination water. Mineral scale deposition formed for water of both low and high hardness (a range representative of municipal water resources) due to high degrees of mineral saturation. The use of rainwater could both mitigate the challenges of scale deposition from municipal tap water (by providing excellent water quality) and decrease water consumption by reducing bleed rate.

  13. The dynamics of cooling water discharge in a shallow, non-tidal embayment

    NASA Astrophysics Data System (ADS)

    Hofmeister, Richard; Bolding, Karsten; Hetland, Robert D.; Schernewski, Gerald; Siegel, Herbert; Burchard, Hans

    2013-12-01

    The dynamics of cooling water spreading in a non-tidal embayment is subject of a modelling-based study of Greifswald Bay, a shallow embayment at the south-western coast of the Baltic Sea. Potential cooling water spreading due to a possible power plant at Greifswald Bay is evaluated as differences between a realistic hind-cast simulation and a similar simulation but including the cooling water pumping. The model results are confirmed with satellite imagery of the embayment during operation of a nuclear power plant in the 1980s. The effect of cooling water pumping on the residual circulation, additional stratification and the heating of near-bed waters in the herring spawning areas is evaluated from the simulation. The model results for an idealised embayment and the realistic scenario, as well as the satellite images, show a clear dependence of the plume spreading on the wind direction. Although the surface plume affects a large area of the embayment, the results show a localised impact on residual circulation, bulk stratification and heating of the waterbody.

  14. Ultimate Heat Sink Thermal Performance and Water Utilization: Measurements on Cooling and Spray Ponds

    SciTech Connect

    Athey, G. F.; Hadlock, R. K.; Abbey, O. B.

    1982-02-01

    A data acquisition research program, entitled "Ultimate Heat Sink Performance Field Experiments," has been brought to completion. The primary objective is to obtain the requisite data to characterize thermal performance and water utilization for cooling ponds and spray ponds at elevated temperature. Such data are useful for modeling purposes, but the work reported here does not contain modeling efforts within its scope. The water bodies which have been studied are indicative of nuclear reactor ultimate heat sinks, components of emergency core cooling systems. The data reflect thermal performance and water utilization for meteorological and solar influences which are representative of worst-case combinations of conditions. Constructed water retention ponds, provided with absolute seals against seepage, have been chosen as facilities for the measurement programs; the first pond was located at Raft River, Idaho, and the second at East Mesa, California. The data illustrate and describe, for both cooling ponds and spray ponds, thermal performance and water utilization as the ponds cool from an initially elevated temperature. To obtain the initial elevated temperature, it has been convenient to conduct the measurements at geothermal sites having large supplies and delivery rates of hot geothermal fluid. The data are described and discussed in the text, and presented in the form of data volumes as appendices.

  15. Comprehensive Cooling Water Study: Volume 5, Aquatic ecology, Savannah River Plant: Final report

    SciTech Connect

    Specht, W.L.

    1987-10-01

    The Comprehensive Cooling Water Study (CCWS) was initiated in 1983 to evaluate the environmental effects of the intake and release of cooling water on the structure and function of aquatic ecosystems at the Savannah River Plant. The initial report (Gladden et al., 1985) described the results from the first year of the study. This document is the final report and concludes the program. The report comprises eight volumes. The first is a summary of environmental effects. The other seven volumes address water quality, radionuclide and heavy metal transport, wetlands, aquatic ecology, Federally endangered species, ecology of Par Pond, and waterfowl. This report documents the results of the Aquatic Ecology Program of the Comprehensive Cooling Water Study. The purpose of the Aquatic Ecology Program was to determine the environmental impacts of cooling water intake and release on the biological communities of SRP streams and swamps and the Savannah River, and the significance of these impacts on the SRP environment. 171 refs., 132 figs., 165 tabs.

  16. Effect of cooling during inter-exercise periods on subsequent intramuscular water movement and muscle performance.

    PubMed

    Yanagisawa, O; Otsuka, S; Fukubayashi, T

    2014-02-01

    To evaluate the effects of cooling between exercise sessions on intramuscular water movement and muscle performance, the lower extremities of nine untrained men were assigned to either a cooling protocol (20-min water immersion, 15 °C) or a noncooling protocol. Each subject performed two exercise sessions involving maximal concentric knee extension and flexion (three repetitions, 60°/s; followed by 50 repetitions, 180°/s). The peak torque at 60°/s and total work, mean power, and decrease rate of torque value at 180°/s were evaluated. Axial magnetic resonance diffusion-weighted images of the mid-thigh were obtained before and after each exercise session. Apparent diffusion coefficient (ADC) values for the quadriceps and hamstrings were calculated for evaluating intramuscular water movement. Both groups exhibited significantly increased ADC values for the quadriceps and hamstrings after each exercise session. These ADC values returned to the pre-exercise level after water immersion. No significant difference was observed in muscle performance from first exercise session to the next in either group, except for increased total work and mean power in knee flexion in the cooled group. Cooling intervention between exercise sessions decreased exercise-induced elevation of intramuscular water movement and had some beneficial effects on muscle endurance of knee flexors, but not knee extensors. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Columnar joint morphology and cooling rate: A starch-water mixture experiment

    NASA Astrophysics Data System (ADS)

    Toramaru, A.; Matsumoto, T.

    2004-02-01

    An analogue experiment using a starch-water mixture has been carried out in order to understand the effect of cooling rate on the morphological characteristics of a basalt columnar joint. If the contraction of material is essential for the formation of columnar joint structure, the water loss rate by desiccation (hereafter referred to as desiccation rate) in the experiment is analogous to the cooling rate in solidifying basalt. In the experiment the desiccation rate is controlled by varying the distance between the starch-water mixture and a lamp used as the heat source. We find that there are three regimes in the relation between joint formation and desiccation rate: (1) At desiccation rates higher than ˜1.4 × 10-2 (g cm-2 h-1) (normal columnar joint regime), the average cross-sectional area S of a column is inversely proportional to the average desiccation rate, (i.e., S ∝ -δ, with δ = 1). (2) Between that desiccation rate and a critical desiccation rate, 0.8 × 10-2 (g/cm2h), S approaches infinity as decreases close to a critical desiccation rate (i.e., exponent δ monotonically increases from unity to infinity) (critical regime). (3) Below the critical desiccation rate, no columnar structure forms (no columnar joint regime forms). Applying the present experimental result to the formation of basalt column, the basalt columnar cross-sectional area is inversely proportional to the cooling rate with factors including elasticity, crack growth coefficient, thermal expansion, glass transition temperature, and crack density ratio at stress maximum. Also, it can be predicted that there exists a critical cooling rate below which the columnar joint does not form; the presence of a critical regime between the normal columnar jointing and no columnar jointing during a certain cooling rate range can also be predicted. We find that at higher cooling rate the preferred column shape is a pentagon, whereas at lower cooling rate it is a hexagon.

  18. Critical Design Issues of Tokamak Cooling Water System of ITER's Fusion Reactor

    SciTech Connect

    Kim, Seokho H; Berry, Jan

    2011-01-01

    U.S. ITER is responsible for the design, engineering, and procurement of the Tokamak Cooling Water System (TCWS). The TCWS transfers heat generated in the Tokamak to cooling water during nominal pulsed operation 850 MW at up to 150 C and 4.2 MPa water pressure. This water contains radionuclides because impurities (e.g., tritium) diffuse from in-vessel components and the vacuum vessel by water baking at 200 240 C at up to 4.4MPa, and corrosion products become activated by neutron bombardment. The system is designated as safety important class (SIC) and will be fabricated to comply with the French Order concerning nuclear pressure equipment (December 2005) and the EU Pressure Equipment Directive using ASME Section VIII, Div 2 design codes. The complexity of the TCWS design and fabrication presents unique challenges. Conceptual design of this one-of-a-kind cooling system has been completed with several issues that need to be resolved to move to next stage of the design. Those issues include flow balancing between over hundreds of branch pipelines in parallel to supply cooling water to blankets, determination of optimum flow velocity while minimizing the potential for cavitation damage, design for freezing protection for cooling water flowing through cryostat (freezing) environment, requirements for high-energy piping design, and electromagnetic impact to piping and components. Although the TCWS consists of standard commercial components such as piping with valves and fittings, heat exchangers, and pumps, complex requirements present interesting design challenges. This paper presents a brief description of TCWS conceptual design and critical design issues that need to be resolved.

  19. Formation of assimilable organic carbon during oxidation of natural waters with ozone, chlorine dioxide, chlorine, permanganate, and ferrate.

    PubMed

    Ramseier, Maaike K; Peter, Andreas; Traber, Jacqueline; von Gunten, Urs

    2011-02-01

    Five oxidants, ozone, chlorine dioxide, chlorine, permanganate, and ferrate were studied with regard to the formation of assimilable organic carbon (AOC) and oxalate in absence and presence of cyanobacteria in lake water matrices. Ozone and ferrate formed significant amounts of AOC, i.e. more than 100 μg/L AOC were formed with 4.6 mg/L ozone and ferrate in water with 3.8 mg/L dissolved organic carbon. In the same water samples chlorine dioxide, chlorine, and permanganate produced no or only limited AOC. When cyanobacterial cells (Aphanizomenon gracile) were added to the water, an AOC increase was detected with ozone, permanganate, and ferrate, probably due to cell lysis. This was confirmed by the increase of extracellular geosmin, a substance found in the selected cyanobacterial cells. AOC formation by chlorine and chlorine dioxide was not affected by the presence of the cells. The formation of oxalate upon oxidation was found to be a linear function of the oxidant consumption for all five oxidants. The following molar yields were measured in three different water matrices based on oxidant consumed: 2.4-4.4% for ozone, 1.0-2.8% for chlorine dioxide and chlorine, 1.1-1.2% for ferrate, and 11-16% for permanganate. Furthermore, oxalate was formed in similar concentrations as trihalomethanes during chlorination (yield ∼ 1% based on chlorine consumed). Oxalate formation kinetics and stoichiometry did not correspond to the AOC formation. Therefore, oxalate cannot be used as a surrogate for AOC formation during oxidative water treatment.

  20. Ultrafast cooling by covalently bonded graphene-carbon nanotube hybrid immersed in water

    NASA Astrophysics Data System (ADS)

    Chen, Jie; Walther, Jens H.; Koumoutsakos, Petros

    2016-11-01

    The increasing power density and the decreasing dimensions of transistors present severe thermal challenges to the design of modern microprocessors. Furthermore, new technologies such as three-dimensional chip-stack architectures require novel cooling solutions for their thermal management. Here, we demonstrate, through transient heat-dissipation simulations, that a covalently bonded graphene-carbon nanotube (G-CNT) hybrid immersed in water is a promising solution for the ultrafast cooling of such high-temperature and high heat-flux surfaces. The G-CNT hybrid offers a unique platform to integrate the superior axial heat transfer capability of individual CNTs via their parallel arrangement. The immersion of the G-CNT in water enables an additional heat dissipation path via the solid-liquid interaction, allowing for the sustainable cooling of the hot surface under a constant power input of up to 10 000 W cm-2.

  1. Ultrafast cooling by covalently bonded graphene-carbon nanotube hybrid immersed in water.

    PubMed

    Chen, Jie; Walther, Jens H; Koumoutsakos, Petros

    2016-11-18

    The increasing power density and the decreasing dimensions of transistors present severe thermal challenges to the design of modern microprocessors. Furthermore, new technologies such as three-dimensional chip-stack architectures require novel cooling solutions for their thermal management. Here, we demonstrate, through transient heat-dissipation simulations, that a covalently bonded graphene-carbon nanotube (G-CNT) hybrid immersed in water is a promising solution for the ultrafast cooling of such high-temperature and high heat-flux surfaces. The G-CNT hybrid offers a unique platform to integrate the superior axial heat transfer capability of individual CNTs via their parallel arrangement. The immersion of the G-CNT in water enables an additional heat dissipation path via the solid-liquid interaction, allowing for the sustainable cooling of the hot surface under a constant power input of up to 10 000 W cm(-2).

  2. Post exercise changes in compartmental body temperature accompanying intermittent cold water cooling in the hyperthermic horse.

    PubMed

    Marlin, D J; Scott, C M; Roberts, C A; Casas, I; Holah, G; Schroter, R C

    1998-01-01

    Whereas the efficacy of cold water cooling of horses has been demonstrated by several studies, the dynamics of temperature changes within and between compartments (primarily muscle, blood [core], skin and deep core [rectal]) have not been investigated. Changes in body temperature associated with cold water cooling were investigated in the hyperthermic horse. Muscle (TMU), pulmonary artery (TPA), rectal (TREC), tail-skin (TTSK) and coat surface (TCOAT) temperatures, were monitored continuously in 5 Thoroughbred horses during and after exercise in hot humid (30 degrees C and 80% RH) conditions on a treadmill. Horses were cooled in the hot humid environment with cold water (approximately 6 degrees C) for 6 30 s periods. Between each 30 s cooling period the horses stood for 30 s. A total of 180 l of cold water was applied. Horses were monitored for a further 4 min following the final cooling period. From the end of exercise to the end of the final cooling (6.5 min), mean (+/- s.e.) rates of decrease for TTSK and TPA were similar (0.8 +/- 0.1 and 0.8 +/- 0.1 degrees C/min, respectively). The effects on TMU and TREC were less marked, with average rates of 0.2 +/- 0.1 and 0.0 +/- 0.1 degrees C/min, respectively. During the first 4 min of cooling, TPA fell during the 30 s period of water application and rose during each 30 s period of standing. When TPA fell below approximately 36.5 degrees C, these variations were suppressed and TPA rose steadily, despite continued applications; TREC and TMU continued to fall, although less rapidly than before. These observations are consistent with the onset of skin vasoconstriction at low TPA. The mechanism is mediated through a cooling of circulating blood volume providing a greater capacity for heat transfer between muscle and circulation. Intermittent application of cold water (approximately 6 degrees C) improves heat removal without apparent deleterious effects and is well tolerated. Even when hypothermia develops (based on TPA

  3. Do cool water or physiologic saline compresses enhance resolution of experimentally-induced irritant contact dermatitis?

    PubMed

    Levin, C Y; Maibach, H I

    2001-09-01

    Acute irritant contact dermatitis (ICD) is frequently treated with cool water or saline compresses. While presumed effective, little quantitative evaluation documents the treatment's benefit. This study sought to determine the efficacy of both distilled water and physiologic saline compresses on experimentally-induced ICD. 24-h application of both the lipophilic nonanoic acid (NAA) and the hydrophilic sodium lauryl sulfate (SLS) were used to induce irritant contact dermatitis in 9 healthy volunteers. Following irritation, compresses were applied 0.5 h 2x daily for 4 consecutive days. Transepidermal water loss (TEWL), laser Doppler flowmetry (LDF), chromametry and visual scoring were used to quantify results. Cool compresses of both water and saline significantly reduced TEWL and LDF, with no statistically significant difference between the efficacy of the saline or water compresses. Chromametry and visual scoring did not detect a significant effect with either the water or saline compresses. The results suggest an improvement with 2x-daily application of either water or physiologic saline compresses in the treatment of acute ICD, though true clinical benefit will be elucidated through further experimentation. Certainly, the current recommendation regarding the use of cool compresses for treating ICD should not be discarded.

  4. Evaluation of nonpotable ground water in the desert area of southeastern California for powerplant cooling

    USGS Publications Warehouse

    Steinemann, Anne C.

    1989-01-01

    Powerplant siting is dependent upon many factors; in southern California the prevailing physical constraint is water availability. Increasing land-use and other environmental concerns preclude further sites along the coast. A review of available hydrologic data was made of 142 ground-water basins in the southeast California desert area to ascertain if any could be feasible sources of nonpotable powerplant cooling water. Feasibility implies the capacity to sustain a typical 1,000-megawatt electrical-power generating plant for 30 years with an ample supply of ground water for cooling. Of the 142 basins reviewed, 5 met or exceeded established hydrologic criteria for supplying the water demands of a typical powerplant. These basins are: (1) middle Amargosa valley, (2) Soda Lake valley, (3) Caves Canyon valley, (4) Chuckwalla Valley, and (5) Calzona-Vidal Valley. Geohydrologic evaluations of these five basins assessed the occurrence and suitability of ground water and effects of long-term pumping. An additional six basins met or exceeded hydrologic criteria, with qualifications, for providing powerplant cooling water. The remaining 131 basins either did not meet the criteria, or available data were insufficient to determine if the basins would meet the criteria.

  5. APT cooling water supply make-up trade study. Revision 1

    SciTech Connect

    Reynolds, R.W.; Hink, R.

    1996-08-08

    In the conceptual design of the APT cooling water system, several options exist for the design of the system(s) which serve as the ultimate heat sink. This study will evaluate alternative methods of providing an ultimate heat sink to the APT.

  6. Why Do Objects Cool More Rapidly in Water than in Still Air?

    ERIC Educational Resources Information Center

    Bohren, Craig F.

    2011-01-01

    An Internet search for why objects, especially humans, cool more rapidly in water than in air, both at the same temperature, and by how much, yields off-the-cuff answers unsupported by experiment or analysis. To answer these questions in depth requires a smattering of engineering heat transfer, including radiative transfer, and the different…

  7. 40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning...

  8. 40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning...

  9. 40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning...

  10. Why Do Objects Cool More Rapidly in Water than in Still Air?

    ERIC Educational Resources Information Center

    Bohren, Craig F.

    2011-01-01

    An Internet search for why objects, especially humans, cool more rapidly in water than in air, both at the same temperature, and by how much, yields off-the-cuff answers unsupported by experiment or analysis. To answer these questions in depth requires a smattering of engineering heat transfer, including radiative transfer, and the different…

  11. 40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning...

  12. 40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning...

  13. Adapting irrigation management to water scarcity: constraints of plant growth, hydraulics and carbon assimilation.

    USDA-ARS?s Scientific Manuscript database

    Water shortages are responsible for the greatest crop losses around the world and are expected to worsen. In arid areas where agriculture is dependent on irrigation, various forms of deficit irrigation management have been suggested to optimize crop yields for available soil water. The relationshi...

  14. Combined cooling and purification system for nuclear reactor spent fuel pit, refueling cavity, and refueling water storage tank

    DOEpatents

    Corletti, M.M.; Lau, L.K.; Schulz, T.L.

    1993-12-14

    The spent fuel pit of a pressured water reactor (PWR) nuclear power plant has sufficient coolant capacity that a safety rated cooling system is not required. A non-safety rated combined cooling and purification system with redundant branches selectively provides simultaneously cooling and purification for the spent fuel pit, the refueling cavity, and the refueling water storage tank, and transfers coolant from the refueling water storage tank to the refueling cavity without it passing through the reactor core. Skimmers on the suction piping of the combined cooling and purification system eliminate the need for separate skimmer circuits with dedicated pumps. 1 figures.

  15. Combined cooling and purification system for nuclear reactor spent fuel pit, refueling cavity, and refueling water storage tank

    DOEpatents

    Corletti, Michael M.; Lau, Louis K.; Schulz, Terry L.

    1993-01-01

    The spent fuel pit of a pressured water reactor (PWR) nuclear power plant has sufficient coolant capacity that a safety rated cooling system is not required. A non-safety rated combined cooling and purification system with redundant branches selectively provides simultaneously cooling and purification for the spent fuel pit, the refueling cavity, and the refueling water storage tank, and transfers coolant from the refueling water storage tank to the refueling cavity without it passing through the reactor core. Skimmers on the suction piping of the combined cooling and purification system eliminate the need for separate skimmer circuits with dedicated pumps.

  16. Reduction of Fire Hazard in Materials for Irrigators and Water Collectors in Cooling Towers

    SciTech Connect

    Smirnov, N. V.; Konstantinova, N. I.; Gordon, E. P.; Poedintsev, E. A.

    2016-09-15

    A way of reducing the fire hazard of PVC film used to make cooling-tower irrigators and water collectors is examined. A new generation of fire retardant, nanostructured magnesium hydroxide, is used to impart fire retardant properties. The fabrication technology is optimized with a roller-calendering manufacturing technique, and the permissible ranges of fire hazard indicators for materials in irrigators and water collectors are determined.

  17. Fish mortality by impingement on the cooling-water intake screens of Britain's largest direct-cooled power station.

    PubMed

    Greenwood, M F D

    2008-04-01

    An estimated 5.66 x 10(7) fish (summed quarterly 95% confidence intervals: 3.01 x 10(7)-1.07 x 10(8)) weighing 258.4 t (143.2-467.9 t) were killed on the cooling-water intake screens of the 2400 MW Longannet Power Station (Forth estuary) in January 1999--December 2000. Abundance and number of species (40) collected were close to predictions for a power station of this size and latitude. Potential losses of equivalent adult whiting (Merlangius merlangus), cod (Gadus morhua), and plaice (Pleuronectes platessa) through deaths of juveniles were estimated at 353.1 t (208.0-603.2 t) worth approximately euro 429,266 (euro 246,592-752,765) in 1999--2000. Fish catch-per-trawl in the estuary was generally not noticeably greater during a year of low water withdrawal (coal miners' strike of 1984--1985) when compared to other years from 1982 to 2001, except for gobies (Pomatoschistus spp.). A fish-return system is being tested at Longannet to reduce mortality.

  18. Characterization of N-Acylhomoserine Lactones Produced by Bacteria Isolated from Industrial Cooling Water Systems.

    PubMed

    Okutsu, Noriya; Morohoshi, Tomohiro; Xie, Xiaonan; Kato, Norihiro; Ikeda, Tsukasa

    2015-12-30

    The cooling water systems are used to remove heat generated in the various industries. Biofouling of the cooling water systems causes blocking of condenser pipes and the heat exchanger tubes. In many Gram-negative bacteria, N-acylhomoserine lactone (AHL) are used as quorum-sensing signal molecule and associated with biofilm formation. To investigate the relationship between quorum sensing and biofouling in the cooling water system, we isolated a total of 192 bacterial strains from the five cooling water systems, and screened for AHL production. Seven isolates stimulated AHL-mediated purple pigment production in AHL reporter strain Chromobacterium violaceum CV026 or VIR07. Based on their 16S rRNA gene sequences, AHL-producing isolates were assigned to Aeromonas hydrophila, Lysobacter sp., Methylobacterium oryzae, and Bosea massiliensis. To the best of our knowledge, B. massiliensis and Lysobacter sp. have not been reported as AHL-producing species in the previous researches. AHLs extracted from the culture supernatants of B. massiliensis and Lysobacter sp. were identified by liquid chromatography-mass spectrometry. AHLs produced by B. massiliensis were assigned as N-hexanoyl-L-homoserine lactone (C6-HSL), N-(3-oxohexanoyl)-L-homoserine lactone (3-oxo-C6-HSL), and N-(3-oxooctanoyl)-L-homoserine lactone (3-oxo-C8-HSL). AHLs produced by Lysobacter sp. were assigned as N-decanoyl-L-homoserine lactone (C10-HSL) and N-(3-oxodecanoyl)-L-homoserine lactone (3-oxo-C10-HSL). This is the first report of identification of AHLs produced by B. massiliensis and Lysobacter sp. isolated from the cooling water system.

  19. Patterns of fish assemblage structure and dynamics in waters of the Savannah River Plant. Comprehensive Cooling Water Study final report

    SciTech Connect

    Aho, J.M.; Anderson, C.S.; Floyd, K.B.; Negus, M.T.; Meador, M.R.

    1986-06-01

    Research conducted as part of the Comprehensive Cooling Water Study (CCWS) has elucidated many factors that are important to fish population and community dynamics in a variety of habitats on the Savannah River Plant (SRP). Information gained from these studies is useful in predicting fish responses to SRP operations. The overall objective of the CCWS was (1) to determine the environmental effects of SRP cooling water withdrawals and discharges and (2) to determine the significance of the cooling water impacts on the environment. The purpose of this study was to: (1) examine the effects of thermal plumes on anadromous and resident fishes, including overwintering effects, in the SRP swamp and associated tributary streams; (2) assess fish spawning and locate nursery grounds on the SRP; (3) examine the level of use of the SRP by spawning fish from the Savannah River, this objective was shared with the Savannah River Laboratory, E.I. du Pont de Nemours and Company; and (4) determine impacts of cooling-water discharges on fish population and community attributes. Five studies were designed to address the above topics. The specific objectives and a summary of the findings of each study are presented.

  20. Effect of makeup water properties on the condenser fouling in power planr cooling system

    SciTech Connect

    Safari, I.; Walker, M.; Abbasian, J.; Arastoopour, H.; Hsieh, M-K.; Dzombak, D.; Miller, D.

    2011-01-01

    The thermoelectric power industry in the U.S. uses a large amount of fresh water. As available freshwater for use in thermoelectric power production becomes increasingly limited, use of nontraditional water sources is of growing interest. Utilization of nontraditional water, in cooling systems increases the potential for mineral precipitation on heat exchanger surfaces. In that regard, predicting the accelerated rate of scaling and fouling in condenser is crucial to evaluate the condenser performance. To achieve this goal, water chemistry should be incorporated in cooling system modeling and simulation. This paper addresses the effects of various makeup water properties on the cooling system, namely pH and aqueous speciation, both of which are important factors affecting the fouling rate in the main condenser. Detailed modeling of the volatile species desorption (i.e. CO{sub 2} and NH{sub 3}), the formation of scale in the recirculating system, and the relationship between water quality and the corresponding fouling rates is presented.

  1. Application of data assimilation for improved operational water level forecasting on the northwest European shelf and North Sea

    NASA Astrophysics Data System (ADS)

    Zijl, Firmijn; Sumihar, Julius; Verlaan, Martin

    2015-12-01

    For the Netherlands, accurate water level forecasting in the coastal region is crucial, since large areas of the land lie below sea level. During storm surges, detailed and timely water level forecasts provided by an operational storm surge forecasting system are necessary to support, for example, the decision to close the movable storm surge barriers in the Eastern Scheldt and the Rotterdam Waterway. In the past years, a new generation operational tide-surge model (Dutch Continental Shelf Model version 6) has been developed covering the northwest European continental shelf. In a previous study, a large effort has been put in representing relevant physical phenomena in this process model as well as reducing parameter uncertainty over a wide area. While this has resulted in very accurate water level representation (root-mean-square error (RMSE) ˜7-8 cm), during severe storm surges, the errors in the meteorological model forcing are generally non-negligible and can cause forecast errors of several decimetres. By integrating operationally available observational data in the forecast model by means of real-time data assimilation, the errors in the meteorological forcing are prevented from propagating to the hydrodynamic tide-surge model forecasts. This paper discusses the development of a computationally efficient steady-state Kalman filter to enhance the predictive quality for the shorter lead times by improving the system state at the start of the forecast. Besides evaluating the model quality against shelf-wide tide gauge observations for a year-long hindcast simulation, the predictive value of the Kalman filter is determined by comparing the forecast quality for various lead time intervals against the model without a steady-state Kalman filter. This shows that, even though the process model has a water level representation that is substantially better than that of other comparable operational models of this scale, substantial improvements in predictive quality in

  2. Review of the effects of the Clean Water Act on cooling-system selection by the steam-electric industry

    SciTech Connect

    Paddock, R.A.; McCown, D.L.

    1982-06-01

    A review of surveys of the steam-electric industry in general and the nuclear industry in particular has shown a significant trend away from open-cycle cooling and toward closed-cycle cooling that is at least in part a consequence of the Clean Water Act and subsequent EPA guidelines and standards. Among older plants, which are not significantly affected by the Clean Water Act, nearly 85% use some form of open-cycle cooling. However, among plants that are under construction or planned, only 10 to 15% plan to use open-cycle cooling. Most of this trend is apparently due to anticipation of restrictions on open-cycle cooling rather than to direct action by the EPA prohibiting open-cycle cooling at specific sites, because requests for permission to operate open-cycle cooling systems have been denied for less than 1% of all existing and new capacity. A review was made of the potential environmental effects, water consumption rates, capital and generating costs, and energy usage associated with open-cycle and closed-cycle cooling systems. No evidence was found that clearly supports a general preference for any type of cooling system over another. However, on a case-by-cae basis, site-specific conditions may indicate a preferred cooling technology. It is concluded that the opportunity for the use of all available cooling options should be retained and that an effort should be made to assure the steam-electric industry that the options are indeed available.

  3. Performance evaluation of heat-stressed commercial broilers provided water-cooled floor perches.

    PubMed

    Reilly, W M; Koelkebeck, K W; Harrison, P C

    1991-08-01

    A study was conducted to determine whether water-cooled floor perches would be utilized by commercial broilers exposed to a constant hot ambient environment; and subsequently, whether utilization of these perches would improve performance beyond those provided uncooled floor perches. A total of 330 day-old commercial broiler chicks were randomly allocated to six pens (2.44 m2) in an environmentally controlled facility and maintained in a thermoneutral brooding environment for 16 days. Following this period, 240 birds were selected on a body weight basis and randomly assigned to the six pens. A perch constructed from steel pipe (2.44 m length, 5.0 cm diameter) was then placed diagonally on the litter covered floor of each pen. The birds were first exposed to a thermoneutral period (27.7 C), during which time cooling of the perches in three replicate pens was initiated by circulating tap water. The other three experimental pens received ambient perches. Ambient temperature was then raised to 32.6 C for the following 4 wk. The results of the present study showed that utilization of water-cooled perches by broilers was greater (P less than or equal to .01) than ambient perch utilization throughout the 32.6 C period. Average daily gain was greatest (P less than or equal to .01) for broilers exposed to cool perches. Additionally, they consume more feed (P less than or equal to .05), on a daily basis, than those given ambient perches during the heat-stress period. Broilers exposed to water-cooled perches also had a more efficient gain to feed ratio (P less than or equal to .01). At the completion of the study, final body weight and total body weight gain were greater (P less than or equal to .05) for broilers given water-cooled perches compared with those exposed to ambient perches. Total amount of feed consumed and total feed efficiency were only moderately affected (P less than or equal to .10) by perch treatments. These results indicated that water-cooled perches were

  4. Cool C4 Photosynthesis - Pyruvate Pi dikinase expression and activity corresponds to the exceptional cold tolerance of carbon assimilation in Miscanthus x giganteus

    USDA-ARS?s Scientific Manuscript database

    The biofuel feedstock grass Miscanthus x giganteus is exceptional among C4 species in its high productivity in cold climates. It can maintain photosynthetically active leaves at temperatures 6°C below the minimum for Zea mays (maize), which allows it a longer growing season in cool climates. Underst...

  5. Hypotheses of calculation of the water flow rate evaporated in a wet cooling tower

    SciTech Connect

    Bourillot, C.

    1983-08-01

    The method developed by Poppe at the University of Hannover to calculate the thermal performance of a wet cooling tower fill is presented. The formulation of Poppe is then validated using full-scale test data from a wet cooling tower at the power station at Neurath, Federal Republic of Germany. It is shown that the Poppe method predicts the evaporated water flow rate almost perfectly and the condensate content of the warm air with good accuracy over a wide range of ambient conditions. The simplifying assumptions of the Merkel theory are discussed, and the errors linked to these assumptions are systematically described, then illustrated with the test data.

  6. Use of Produced Water in Recirculating Cooling Systems at Power Generating Facilities

    SciTech Connect

    Kent Zammit; Michael N. DiFilippo

    2005-07-01

    The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. This deliverable describes possible test configurations for produced water demonstration projects at SJGS. The ability to host demonstration projects would enable the testing and advancement of promising produced water treatment technologies. Testing is described for two scenarios: Scenario 1--PNM builds a produced water treatment system at SJGS and incorporates planned and future demonstration projects into the design of the system. Scenario 2--PNM forestalls or decides not to install a produced water treatment system and would either conduct limited testing at SJGS (produced water would have to be delivered by tanker trucked) or at a salt water disposal facility (SWD). Each scenario would accommodate demonstration projects differently and these differences are discussed in this deliverable. PNM will host a demonstration test of water-conserving cooling technology--Wet Surface Air Cooling (WSAC) using cooling tower blowdown

  7. Assimilation of Sentinel-1 estimates of Precipitable Water Vapor (PWV) into a Numerical Weather Model for a more accurate forecast of extreme weather events

    NASA Astrophysics Data System (ADS)

    Mateus, Pedro; Nico, Giovanni; Catalao, Joao

    2017-04-01

    In the last two decades, SAR interferometry has been used to obtain maps of Precipitable Water Vapor (PWV).This maps are characterized by their high spatial resolution when compared to the currently available PWV measurements (e.g. GNSS, radiometers or radiosondes). Several previous works have shown that assimilating PWV values, mainly derived from GNSS observations, into Numerical Weather Models (NWMs) can significantly improve rainfall predictions.It is noteworthy that the PWV-derived from GNSS observations have a high temporal resolution but a low spatialone. In addition, there are many regions without any GNSS stations, where temporal and spatial distribution of PWV areonly available through satellite measurements. The first attempt to assimilate InSAR-derived maps of PWV (InSAR-PWV) into a NWM was made by Pichelli et al. [1].They used InSAR-PWV maps obtained from ENVISAT-ASAR images and the mesoscale weather prediction model MM5 over the city of Rome, Italy. The statistical indices show that the InSAR-PWVdata assimilation improves the forecast of weak to moderateprecipitation (< 15 mm/3-h). The second and last attempt, was performed by Mateus et al. [2]. They used the same satellite mission and the Weather Research and Forecast (WRF) model over the city of Lisbon, Portugal, during a light rain event not forecast by the model.Results showed that after data assimilation, there is a bias correction of the PWV field and an improvement in the forecast of the weakto moderate rainfall up to 9 h after the assimilation time. We used, for the first time, the Weather Research and Forecast Data Assimilation (WRFDA) model, at micro-scale resolutions (3 km), over the Iberian Peninsula (focusing on the southern region of Spain) and during a convective cell associated with a local heavy rainfall event, to study the impact of assimilation PWV maps obtained from SAR interferometric phase calculated using images acquired by the Sentinel-1 satellite. It's worth noting that, in

  8. Organohalogen products from chlorination of cooling water at nuclear power stations

    SciTech Connect

    Bean, R.M.

    1983-10-01

    Eight nuclear power units at seven locations in the US were studied to determine the effects of chlorine, added as a biocide, on the composition of cooling water discharge. Water, sediment and biota samples from the sites were analyzed for total organic halogen and for a variety of organohalogen compounds. Haloforms were discharged from all plants studied, at concentrations of a few ..mu..g/L (parts-per-billion). Evidence was obtained that power plants with cooling towers discharge a significant portion of the haloforms formed during chlorination to the atmosphere. A complex mixture of halogenated phenols was found in the cooling water discharges of the power units. Cooling towers can act to concentrate halogenated phenols to levels approaching those of the haloforms. Examination of samples by capillary gas chromatography/mass spectrometry did not result in identification of any significant concentrations of lipophilic base-neutral compounds that could be shown to be formed by the chlorination process. Total concentrations of lipophilic (Bioabsorbable) and volatile organohalogen material discharged ranged from about 2 to 4 ..mu..g/L. Analysis of sediment samples for organohalogen material suggests that certain chlorination products may accumulate in sediments, although no tissue bioaccumulation could be demonstrated from analysis of a limited number of samples. 58 references, 25 figures, 31 tables.

  9. Impact of drought on U.S. steam electric power plant cooling water intakes and related water resource management issues.

    SciTech Connect

    Kimmell, T. A.; Veil, J. A.; Environmental Science Division

    2009-04-03

    This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements their overall research effort by evaluating water availability at power plants under drought conditions. While there are a number of competing demands on water uses, particularly during drought conditions, this report focuses solely on impacts to the U.S. steam electric power plant fleet. Included are both fossil-fuel and nuclear power plants. One plant examined also uses biomass as a fuel. The purpose of this project is to estimate the impact on generation capacity of a drop in water level at U.S. steam electric power plants due to climatic or other conditions. While, as indicated above, the temperature of the water can impact decisions to halt or curtail power plant operations, this report specifically examines impacts as a result of a drop in water levels below power plant submerged cooling water intakes. Impacts due to the combined effects of excessive temperatures of the returned cooling water and elevated temperatures of receiving waters (due to high ambient temperatures associated with drought) may be examined in a subsequent study. For this study, the sources of cooling water used by the U.S. steam electric power plant fleet were examined. This effort entailed development of a database of power plants and cooling water intake locations and depths for those plants that use surface water as a source of cooling water. Development of the database and its general characteristics are described in Chapter 2 of this report. Examination of the database gives an indication of how low water levels can drop before cooling water intakes cease to function. Water level drops are evaluated against a number of different power plant characteristics, such as the nature of the water source (river vs. lake or reservoir) and type

  10. Assimilation of SMOS soil moisture into a distributed hydrological model and impacts on the water cycle variables over the Ouémé catchment in Benin

    NASA Astrophysics Data System (ADS)

    Leroux, Delphine J.; Pellarin, Thierry; Vischel, Théo; Cohard, Jean-Martial; Gascon, Tania; Gibon, François; Mialon, Arnaud; Galle, Sylvie; Peugeot, Christophe; Seguis, Luc

    2016-07-01

    Precipitation forcing is usually the main source of uncertainty in hydrology. It is of crucial importance to use accurate forcing in order to obtain a good distribution of the water throughout the basin. For real-time applications, satellite observations allow quasi-real-time precipitation monitoring like the products PERSIANN (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks, TRMM (Tropical Rainfall Measuring Mission) or CMORPH (CPC (Climate Prediction Center) MORPHing). However, especially in West Africa, these precipitation satellite products are highly inaccurate and the water amount can vary by a factor of 2. A post-adjusted version of these products exists but is available with a 2 to 3 month delay, which is not suitable for real-time hydrologic applications. The purpose of this work is to show the possible synergy between quasi-real-time satellite precipitation and soil moisture by assimilating the latter into a hydrological model. Soil Moisture Ocean Salinity (SMOS) soil moisture is assimilated into the Distributed Hydrology Soil Vegetation Model (DHSVM) model. By adjusting the soil water content, water table depth and streamflow simulations are much improved compared to real-time precipitation without assimilation: soil moisture bias is decreased even at deeper soil layers, correlation of the water table depth is improved from 0.09-0.70 to 0.82-0.87, and the Nash coefficients of the streamflow go from negative to positive. Overall, the statistics tend to get closer to those from the reanalyzed precipitation. Soil moisture assimilation represents a fair alternative to reanalyzed rainfall products, which can take several months before being available, which could lead to a better management of available water resources and extreme events.

  11. Topographically Driven Lateral Water Fluxes and Their Influence on Carbon Assimilation of a Black Spruce Ecosystem.

    NASA Astrophysics Data System (ADS)

    Govind, A.; Chen, J. M.; Margolis, H.; Bernier, P. Y.

    2006-12-01

    Current estimates of ecophysiological indicators overlook the effects of topographically-driven lateral flow of soil water. We hypothesize that topographically driven lateral water flows over the landscape have significant influence on the terrestrial carbon cycle. To this end, we simulated the hydrological controls on carbon cycle processes in a black spruce forest in central Quebec, Canada, using the Boreal Ecosystem Productivity Simulator (BEPS) at a daily time step. We accounted for lateral surface and subsurface flows in BEPS by incorporating a distributed, process-oriented hydrological procedure. The results show that modeled dynamics of ecophysiological processes such as evapotranspiration (ET) and photosynthesis (GPP) are consistent with the spatial variation of land cover, topography, soil texture, and leaf area index. Simulated ET and GPP averaged within the footprint of an eddy covariance tower in the watershed agree well with flux measurements with R2=0.77 and 0.83 for ET and GPP, respectively. For ET simulation, much of the remaining discrepancies are found in the winter when the model underestimates snow sublimation. For GPP, there is an underestimation in the fall coinciding with a mid growing season drought, showing the high sensitivity of the model to the soil water status. The key processes controlling primary production were hydraulic limitations for water transfer from soil, roots, stems and leaves through stomatal conductance. Therefore, a further understanding of soil water dynamics is warranted. Comparison with the soil water content of the footprint- averaged unsaturated zone showed that the model captured the annual trend. We also simulated the variations in the water table as well as the mid growing season drought, with a reasonable accuracy(R2=0.68). The foot print average water budget reveals that the annual precipitation of 835mm is partitioned into 282mm of ET, 541 mm of subsurface runoff, and 6 mm of storage change. To test the

  12. Ice-Water Immersion and Cold-Water Immersion Provide Similar Cooling Rates in Runners With Exercise-Induced Hyperthermia.

    PubMed

    Clements, Julie M; Casa, Douglas J; Knight, J; McClung, Joseph M; Blake, Alan S; Meenen, Paula M; Gilmer, Allison M; Caldwell, Kellie A

    2002-06-01

    OBJECTIVE: To assess whether ice-water immersion or cold-water immersion is the more effective treatment for rapidly cooling hyperthermic runners. DESIGN AND SETTING: 17 heat-acclimated highly trained distance runners (age = 28 +/- 2 years, height = 180 +/- 2 cm, weight = 68.5 +/- 2.1 kg, body fat = 11.2 +/- 1.3%, training volume = 89 +/- 10 km/wk) completed a hilly trail run (approximately 19 km and 86 minutes) in the heat (wet-bulb globe temperature = 27 +/- 1 degrees C) at an individually selected "comfortable" pace on 3 occasions 1 week apart. The random, crossover design included (1) distance run, then 12 minutes of ice-water immersion (5.15 +/- 0.20 degrees C), (2) distance run, then 12 minutes of cold-water immersion (14.03 +/- 0.28 degrees C), or (3) distance run, then 12 minutes of mock immersion (no water, air temperature = 28.88 +/- 0.76 degrees C). MEASUREMENTS: Each subject was immersed from the shoulders to the hip joints for 12 minutes in a tub. Three minutes elapsed between the distance run and the start of immersion. Rectal temperature was recorded at the start of immersion, at each minute of immersion, and 3, 6, 10, and 15 minutes postimmersion. No rehydration occurred during any trial. RESULTS: Length of distance run, time to complete distance run, rectal temperature, and percentage of dehydration after distance run were similar (P >.05) among all trials, as was the wet-bulb globe temperature. No differences (P >.05) for cooling rates were found when comparing ice-water immersion, cold-water immersion, and mock immersion at the start of immersion to 4 minutes, 4 to 8 minutes, and the start of immersion to 8 minutes. Ice-water immersion and cold-water immersion cooling rates were similar (P >.05) to each other and greater (P <.05) than mock immersion at 8 to 12 minutes, the start of immersion to 10 minutes, and the start of immersion to every other time point thereafter. Rectal temperatures were similar (P >.05) between ice-water immersion and

  13. Ice-Water Immersion and Cold-Water Immersion Provide Similar Cooling Rates in Runners With Exercise-Induced Hyperthermia

    PubMed Central

    Clements, Julie M.; Casa, Douglas J.; Knight, J. Chad; McClung, Joseph M.; Blake, Alan S.; Meenen, Paula M.; Gilmer, Allison M.; Caldwell, Kellie A.

    2002-01-01

    Objective: To assess whether ice-water immersion or cold-water immersion is the more effective treatment for rapidly cooling hyperthermic runners. Design and Setting: 17 heat-acclimated highly trained distance runners (age = 28 ± 2 years, height = 180 ± 2 cm, weight = 68.5 ± 2.1 kg, body fat = 11.2 ± 1.3%, training volume = 89 ± 10 km/wk) completed a hilly trail run (approximately 19 km and 86 minutes) in the heat (wet-bulb globe temperature = 27 ± 1°C) at an individually selected “comfortable” pace on 3 occasions 1 week apart. The random, crossover design included (1) distance run, then 12 minutes of ice-water immersion (5.15 ± 0.20°C), (2) distance run, then 12 minutes of cold-water immersion (14.03 ± 0.28°C), or (3) distance run, then 12 minutes of mock immersion (no water, air temperature = 28.88 ± 0.76°C). Measurements: Each subject was immersed from the shoulders to the hip joints for 12 minutes in a tub. Three minutes elapsed between the distance run and the start of immersion. Rectal temperature was recorded at the start of immersion, at each minute of immersion, and 3, 6, 10, and 15 minutes postimmersion. No rehydration occurred during any trial. Results: Length of distance run, time to complete distance run, rectal temperature, and percentage of dehydration after distance run were similar (P > .05) among all trials, as was the wet-bulb globe temperature. No differences (P > .05) for cooling rates were found when comparing ice-water immersion, cold-water immersion, and mock immersion at the start of immersion to 4 minutes, 4 to 8 minutes, and the start of immersion to 8 minutes. Ice-water immersion and cold-water immersion cooling rates were similar (P > .05) to each other and greater (P < .05) than mock immersion at 8 to 12 minutes, the start of immersion to 10 minutes, and the start of immersion to every other time point thereafter. Rectal temperatures were similar (P > .05) between ice-water immersion and cold-water immersion at the

  14. Volume and structural analysis of super-cooled water under high pressure

    NASA Astrophysics Data System (ADS)

    Duki, Solomon F.; Tsige, Mesfin

    2012-02-01

    Motivated by recent experimental study of super-cooled water at high pressure [1], we performed atomistic molecular dynamic simulations study on bulk water molecules at isothermal-isobaric ensemble. These simulations are performed at temperatures that range from 40 K to 380 K using two different cooling rates, 10K/ns and 10K/5ns, and pressure that ranges from 1atm to 10000 atm. Our analysis for the variation of the volume of the bulk sample against temperature indicates a downward concave shape for pressures above certain values, as reported in [1]. The same downward concave behavior is observed at high pressure on the mean-squared-displacements (MSD) of the water molecules when the MSD is plotted against time. To get further insight on the effect of the pressure on the sample we have also performed a structural analysis of the sample.[4pt] [1] O. Mishima, J. Chem. Phys. 133, 144503 (2010);

  15. A model for calculating radionuclide concentrations in the Fermilab industrial cooling water system

    SciTech Connect

    Cossairt, J.Donald; /Fermilab

    2007-10-01

    Large particle accelerators such as those at the Fermi National Accelerator Laboratory (Fermilab) unavoidably produce radionuclides in their bulk shielding and also require large volume process cooling water systems to handle electrical heat loads. The Neutrinos at the Main Injector (NuMI) beam facility came on line during CY 2005. After several months of initial operation of this facility, measurable concentrations of {sup 3}H as tritiated water were identified throughout the Industrial Cooling Water (ICW) system. This was the first identification of measurable concentrations of any radionuclide leaving the Fermilab site, motivating an extensive effort to understand these discharges in order to minimize environmental releases. As part of this work, a simple model of radionuclide concentrations in this system has been developed.

  16. Ice growth and interface oscillation of water droplets impinged on a cooling surface

    NASA Astrophysics Data System (ADS)

    Hagiwara, Yoshimichi; Ishikawa, Shoji; Kimura, Ryota; Toyohara, Kazumasa

    2017-06-01

    We focused on the attenuation of air-water interface oscillation for impinged water droplets freezing on a cooling surface. We carried out not only experiments but also two-dimensional numerical simulation on the droplets using a Phase-field method and an immersed boundary method. The Reynolds number and Weber number were in the range of 35-129 and 1.6-22, respectively. The experimental and computational results showed that the height of the impinged droplets on the symmetrical axis started to oscillate as a result of the impact of the collision of droplets with the surfaces in all the cases that we investigated. The measured frequency of the oscillations in the case of the adiabatic droplets was equal to the frequency estimated from the equation for the capillary-gravity waves on sessile droplets (Temperton, 2013) [30]. The oscillations converged rapidly in all impinged water droplets that froze on the cooling surface. This is due partly to the growth of ice shells along the air-water interface and partly to decreases in water volume as a result of the ice growth mainly on the cooling surface. In addition, the thermal field was disturbed not only by the latent heat transfer but also by the upward component of recirculating flow induced by the droplet impingement.

  17. Effect of water temperature on cooling efficiency during hyperthermia in humans.

    PubMed

    Proulx, C I; Ducharme, M B; Kenny, G P

    2003-04-01

    We evaluated the cooling rate of hyperthermic subjects, as measured by rectal temperature (T(re)), during immersion in a range of water temperatures. On 4 separate days, seven subjects (4 men, 3 women) exercised at 65% maximal oxygen consumption at an ambient temperature of 39 degrees C until T(re) increased to 40 degrees C (45.4 +/- 4.1 min). After exercise, the subjects were immersed in a circulated water bath controlled at 2, 8, 14, or 20 degrees C until T(re) returned to 37.5 degrees C. No difference in cooling rate was observed between the immersions at 8, 14, and 20 degrees C despite the differences in the skin surface-to-water temperature gradient, possibly because of the presence of shivering at 8 and 14 degrees C. Compared with the other conditions, however, the rate of cooling (0.35 +/- 0.14 degrees C/min) was significantly greater during the 2 degrees C water immersion, in which shivering was seldom observed. This rate was almost twice as much as the other conditions (P < 0.05). Our results suggest that 2 degrees C water is the most effective immersion treatment for exercise-induced hyperthermia.

  18. Investigation of Water-spray Cooling of Turbine Blades in a Turbojet Engine

    NASA Technical Reports Server (NTRS)

    Freche, John C; Stelpflug, William J

    1953-01-01

    An analytical and experimental investigation was made with a J33-A-9 engine to determine the effectiveness of spray cooling as a means of increasing thrust by permitting engine operation at inlet-gas temperatures and speeds above rated. With the assumption of adequate spray cooling at a coolant-to-gas flow ratio of 3 percent, calculations for the sea-level static condition indicated a thrust may be achieved by engine operation at an inlet-gas temperature of 2000 degrees F and an overspeed of 10 percent. Of the water-injection configurations investigated experimentally, those located in the inner ring of the stator diaphragm provided the best cooling at rated engine speed.

  19. Thermohydraulic responses of a water-cooled tokamak fusion DEMO to loss-of-coolant accidents

    NASA Astrophysics Data System (ADS)

    Nakamura, M.; Tobita, K.; Someya, Y.; Utoh, H.; Sakamoto, Y.; Gulden, W.

    2015-11-01

    Major in- and ex-vessel loss-of-coolant accidents (LOCAs) of a water-cooled tokamak fusion DEMO reactor have been analysed. Analyses have identified responses of the DEMO systems to these accidents and pressure loads to confinement barriers for radioactive materials. As for the in-VV LOCA, we analysed the multiple double-ended break of the first wall cooling pipes around the outboard toroidal circumference. As for the ex-VV LOCA, we analysed the double-ended break of the primary cooling pipe. The thermohydraulic analysis results suggest that the in- and ex-vessel LOCAs crucially threaten integrity of the primary and final confinement barriers, respectively. Mitigations of the loads to the confinement barriers are also discussed.

  20. Air-sea Fluxes and Mode Waters in an Eddy Resolving Ocean Data Assimilating Southern Ocean State Estimate (SOSE) (Invited)

    NASA Astrophysics Data System (ADS)

    Cerovecki, I.; Talley, L. D.; Mazloff, M. R.

    2010-12-01

    An eddy-permitting data assimilating system, the Southern Ocean State Estimate (SOSE), has been developed by Mazloff et al. (2010) to estimate the Southern Ocean circulation in years 2005 and 2006. We assess the accuracy of SOSE air-sea heat and freshwater flux estimates by comparing them to widely used flux products (the National Center for Environmental Prediction-National Center for Atmospheric Reanalysis 1 (NCEP1), European Centre for Medium-Range Weather Forecasts operational model) and to a recently developed flux product constructed by Large and Yeager (2009). SOSE and Large and Yeager (2009) estimates show remarkable similarity in the large scale pattern of air-sea fluxes when compared to the NCEP1 fields that SOSE uses as an initial guess and constraint. Having verified that the accuracy of SOSE air-sea buoyancy flux estimate is satisfactory, we use SOSE fluxes and three-dimensional oceanic fields to investigate Subantarctic Mode Water (SAMW) formation and destruction by diapycnal buoyancy exchange at the ocean surface and in the ocean interior as well as identify and quantify SAMW transport pathways. Surface buoyancy fluxes produce on average 6.9 +/-1.6 Sv of Southeast Indian SAMW (SEISAMW) and 4.8 +/- 2.2 Sv of East Pacific SAMW, averaged over years 2005 and 2006. This transformation is largely compensated by diapycnal mixing in the ocean interior where SAMW gets mostly transformed into denser water, especially in the Pacific sector of the Southern Ocean. There is also a net conversion of lighter thermocline water into SAMW in the ocean interior (occurring mostly in the Indian Ocean), which is part of the shallow overturning. The zonally integrated export of SAMW across 30S is thus relatively small and on average equals approximately 3.5 Sv of (SEISAMW) and 2.0 Sv of East Pacific SAMW.

  1. Constraining root-zone soil water availability using data assimilation and satellite remote sensing

    USDA-ARS?s Scientific Manuscript database

    Large-scale monitoring of root-zone soil water availability, and therefore the duration and extent of regional agricultural drought, has emerged as an important application for satellite remote sensing and figures heavily into plans for next-generation earth observing satellites. At present, three ...

  2. Effect of Water Spray Evaporative Cooling at the Inlet of Regeneration Air Stream on the Performance of an Adsorption Desiccant Cooling Process

    NASA Astrophysics Data System (ADS)

    Ando, Kosuke; Kodama, Akio; Hirose, Tsutomu; Goto, Motonobu; Okano, Hiroshi

    This paper shows an influence of evaporative cooler at the inlet of regeneration air stream of an adsorptive desiccant cooling process on the cooling/dehumidifying performance. This evaporative cooling was expected to cause humidity increase in regeneration air reducing the dehumidifying performance of the honeycomb absorber, while the evaporative cooling plays an important role to produce a lower temperature in supply air. Two different airs to be used for the regeneration of the desiccant wheel were considered. One was fresh outside air (OA mode) and the other was air ventilated from the room (RA mode). Experimental results showed that the amount of dehumidified water obtained at the process without water spray evaporative cooler was actually larger than that of process with water spray evaporative cooler. This behavior was mainly due to increase of humidity or relative humidity in the regeneration air as expected. However, temperature of supply air produced by the process with the evaporator was rather lower than that of the other because of the cooled return air, resulting higher CE value. Regarding the operating mode, the evaporative cooler at the OA-mode was no longer useful at higher ambient humidity because of the difficulty of the evaporation of the water in such high humidity. It was also found that its dehumidifying performance was remarkably decreased at higher ambient humidity and lower regeneration temperature since the effective adsorption capacity at the resulting high relative humidity of the regeneration air decreased.

  3. Cooling by cutaneous water evaporation in the heat-acclimated rock pigeon (Columba livia).

    PubMed

    Arieli, Yehuda; Peltonen, Liisa; Ophir, Eshel

    2002-03-01

    The present study provides an up-to-date overview of the cutaneous water-evaporation cooling mechanism in the rock pigeon. Cutaneous water evaporation fully replaces the classic respiratory cooling mechanism in the resting, heat-acclimated bird, and is more economical in terms of water conservation. It enables the pigeon to maintain homeostasis, and to breed successfully in harsh environments. Adrenergic signaling is involved in the initiation of this novel mechanism, either by deactivation of the beta-adrenergic receptors (ARs), or activation of the alpha-AR. The adrenergic signaling results in a marked increase in cutaneous blood flow and in the arterial-to-venous blood-flow ratio. This is associated with alterations in the cutaneous capillary wall ultrastructure, which increase its permeability to plasma proteins and water. The end result of this process might be an increase in water efflux from the capillary lumen. The properties of beta-ARs were measured in the cardiac muscle of thermal-acclimated pigeons. Significant down-regulation in the density of beta-ARs, associated with increased affinity of these receptors, was measured in the heat-acclimated pigeon. Concomitantly, changes in the skin ultrastructure and lipid composition were found in very well defined patches in the epidermis of heat-acclimated pigeons. These suppress the skin resistance to water transfer. We suggest that this cooling mechanism involves finely orchestrated adjustments in the ultrastructure of the skin and the cutaneous capillaries, and in skin blood flow. Adrenergic signals are among those factors that regulate this cooling mechanism during exposure to a hot environment.

  4. A Novel Absorption Cycle for Combined Water Heating, Dehumidification, and Evaporative Cooling

    SciTech Connect

    CHUGH, Devesh; Gluesenkamp, Kyle R; Abdelaziz, Omar; Moghaddam, Saeed

    2014-01-01

    In this study, development of a novel system for combined water heating, dehumidification, and space evaporative cooling is discussed. Ambient water vapor is used as a working fluid in an open system. First, water vapor is absorbed from an air stream into an absorbent solution. The latent heat of absorption is transferred into the process water that cools the absorber. The solution is then regenerated in the desorber, where it is heated by a heating fluid. The water vapor generated in the desorber is condensed and its heat of phase change is transferred to the process water in the condenser. The condensed water can then be used in an evaporative cooling process to cool the dehumidified air exiting the absorber, or it can be drained if primarily dehumidification is desired. Essentially, this open absorption cycle collects space heat and transfers it to process water. This technology is enabled by a membrane-based absorption/desorption process in which the absorbent is constrained by hydrophobic vapor-permeable membranes. Constraining the absorbent film has enabled fabrication of the absorber and desorber in a plate-and-frame configuration. An air stream can flow against the membrane at high speed without entraining the absorbent, which is a challenge in conventional dehumidifiers. Furthermore, the absorption and desorption rates of an absorbent constrained by a membrane are greatly enhanced. Isfahani and Moghaddam (Int. J. Heat Mass Transfer, 2013) demonstrated absorption rates of up to 0.008 kg/m2s in a membrane-based absorber and Isfahani et al. (Int. J. Multiphase Flow, 2013) have reported a desorption rate of 0.01 kg/m2s in a membrane-based desorber. The membrane-based architecture also enables economical small-scale systems, novel cycle configurations, and high efficiencies. The absorber, solution heat exchanger, and desorber are fabricated on a single metal sheet. In addition to the open arrangement and membrane-based architecture, another novel feature of the

  5. Effects of mild hypohydration on cooling during cold-water immersion following exertional hyperthermia.

    PubMed

    Butts, Cory L; Luhring, Katherine E; Smith, Cody R; Tucker, Matthew A; Moyen, Nicole E; Ganio, Matthew S; McDermott, Brendon P

    2016-04-01

    We investigated the effects of mild hypohydration compared to euhydration on the cooling efficacy of cold-water immersion (CWI). Fourteen participants (eight male, six female; age 26 ± 5 years; ht 1.77 ± 0.08 m; wt 72.2 ± 8.8 kg; 20.6 ± 7.4 % body fat) completed one euhydrated (EU) trial followed by one hypohydrated trial (HY; via 24 h fluid restriction) in an environmental chamber (33.6 ± 0.9 °C, 55.8 ± 1.7 % RH). Volitional exercise was performed in a manner that matched end-exercise rectal temperature (T re) through repeating exercise mode and intensity. Participants were then immersed in ice water (2.0 ± 0.8 °C) until T re reached 38.1 °C or for a maximum of 15 min. T re, heart rate (HR), skin blood flux (SBF) and mean skin temperature (T sk) were monitored continuously during cooling. Pre-cooling body mass was decreased in the HY trial (-2.66 ± 1.23 % body mass) and maintained in the EU trial (-0.66 ± 0.44 %) compared to baseline mass (P < 0.001). Cooling rates were faster when EU (0.14 ± 0.05 °C/min) compared to HY (0.11 ± 0.05 °C/min, P = 0.046). HR, SBF, and T sk were not different between EU and HY trials (P > 0.05), however, all variables significantly decreased with immersion independent of hydration status (P < 0.001). The primary finding was that hypohydration modestly attenuates the rate of cooling in exertionally hyperthermic individuals. Regardless of hydration status, the cooling efficacy of CWI was preserved and should continue to be utilized in the treatment of exertional hyperthermia.

  6. Assimilation of satellite altimetry data in hydrological models for improved inland surface water information: Case studies from the "Sentinel-3 Hydrologic Altimetry Processor prototypE" project (SHAPE)

    NASA Astrophysics Data System (ADS)

    Benveniste, J.; Fabry, P. L.; David, G.; Arheimer, B.; Bercher, N.; Roca, M.; Fernandes, J.; Ambrozio, A.; Restano, M.

    2016-12-01

    This communication is about the recently started Sentinel-3 Hydrologic Altimetry Processor prototypE (SHAPE) project, with a focus on the components dealing with assimilation of satellite altimetry data into hydrological models. The SHAPE research and development project started in September 2015, within the Scientific Exploitation of Operational Missions (SEOM) programme of the European Space Agency. The objectives of the project are to further develop and assess recent improvement in altimetry data, processing algorithms and methods for assimilation in hydrological models, with the overarching goal to support improved scientific use of altimetry data and improved inland water information. The objective is also to take scientific steps towards a future Inland Water dedicated processor on the Sentinel-3 ground segment. The study focuses on three main variables of interest in hydrology: river stage, river discharge and lake level. The improved altimetry data from the project is used to estimate river stage, river discharge and lake level information in a data assimilation framework using the hydrological dynamic and semi-distributed model HYPE (Hydrological Predictions for the Environment). This model has been developed by SMHI and includes data assimilation module based on the Ensemble Kalman filter method. The method will be developed and assessed for a number of case studies with available in situ reference data and satellite altimetry data based on mainly the CryoSat-2 mission on which the new processor will be run. The production of alti-hydro products (water level time series) are improved thanks to the use of water masks. This eases the geo-selection of the CryoSat-2 altimetric measurements since there are acquired from a geodetic orbit and are thus spread along the river course in space and and time. The specific processing of data from this geodetic orbit space-time pattern will be discussed as well as the subsequent possible strategies for data

  7. Assimilation of satellite altimetry data in hydrological models for improved inland surface water information: Case studies from the "Sentinel-3 Hydrologic Altimetry Processor prototypE" project (SHAPE)

    NASA Astrophysics Data System (ADS)

    Gustafsson, David; Pimentel, Rafael; Fabry, Pierre; Bercher, Nicolas; Roca, Mónica; Garcia-Mondejar, Albert; Fernandes, Joana; Lázaro, Clara; Ambrózio, Américo; Restano, Marco; Benveniste, Jérôme

    2017-04-01

    This communication is about the Sentinel-3 Hydrologic Altimetry Processor prototypE (SHAPE) project, with a focus on the components dealing with assimilation of satellite altimetry data into hydrological models. The SHAPE research and development project started in September 2015, within the Scientific Exploitation of Operational Missions (SEOM) programme of the European Space Agency. The objectives of the project are to further develop and assess recent improvement in altimetry data, processing algorithms and methods for assimilation in hydrological models, with the overarching goal to support improved scientific use of altimetry data and improved inland water information. The objective is also to take scientific steps towards a future Inland Water dedicated processor on the Sentinel-3 ground segment. The study focuses on three main variables of interest in hydrology: river stage, river discharge and lake level. The improved altimetry data from the project is used to estimate river stage, river discharge and lake level information in a data assimilation framework using the hydrological dynamic and semi-distributed model HYPE (Hydrological Predictions for the Environment). This model has been developed by SMHI and includes data assimilation module based on the Ensemble Kalman filter method. The method will be developed and assessed for a number of case studies with available in situ reference data and satellite altimetry data based on mainly the CryoSat-2 mission on which the new processor will be run; Results will be presented from case studies on the Amazon and Danube rivers and Lake Vänern (Sweden). The production of alti-hydro products (water level time series) are improved thanks to the use of water masks. This eases the geo-selection of the CryoSat-2 altimetric measurements since there are acquired from a geodetic orbit and are thus spread along the river course in space and and time. The specific processing of data from this geodetic orbit space

  8. Data Descriptor: A Land Data Assimilation System for Sub-Saharan Africa Food and Water Security Applications

    NASA Technical Reports Server (NTRS)

    McNally, Amy; Arsenault, Krist; Kumar, Sujay; Shukla, Shraddhanand; Peter, Pete; Wang, Shugong; Funk, Chris; Peters-Lidard, Christa D.; Verdin, James

    2017-01-01

    Seasonal agricultural drought monitoring systems, which rely on satellite remote sensing and land surface models (LSMs), are important for disaster risk reduction and famine early warning. These systems require the best available weather inputs, as well as a long-term historical record to contextualize current observations. This article introduces the Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS), a custom instance of the NASA Land Information System (LIS) framework. The FLDAS is routinely used to produce multi-model and multi-forcing estimates of hydro-climate states and fluxes over semi-arid, food insecure regions of Africa. These modeled data and derived products, like soil moisture percentiles and water availability, were designed and are currently used to complement FEWSNETs operational remotely sensed rainfall, evapotranspiration, and vegetation observations. The 30+ years of monthly outputs from the FLDAS simulations are publicly available from the NASA Goddard Earth Science Data and Information Services Center (GES DISC) and recommended for use in hydroclimate studies, early warning applications, and by agro-meteorological scientists in Eastern, Southern, and Western Africa.

  9. Assimilating water column and satellite data for marine export production estimation

    NASA Astrophysics Data System (ADS)

    Yao, Xiaoping; Schlitzer, Reiner

    2013-04-01

    Recent advances in satellite retrieval methodology now allow estimation of particular organic carbon (POC) concentration in ocean surface waters directly from satellite-based optical data. Because of the good coverage these data reveal small-scale spatial and temporal concentration gradients and document the evolution of surface water POC as well as the underlying driving biogeochemical processes throughout the seasons. Water column nutrient data also reveal biogeochemical activity. However, because of the scarcity of data the deduction of temporal changes of particle production and export are not possible in most parts of the ocean. Here we present first results from a new study combining both data streams thereby exploiting the high spatio-temporal resolution of surface POC concentrations from satellite optical sensors with water column nutrient data having sparser coverage but providing information throughout the entire water column. We use a medium-resolution global model with steady-state 3D circulation that has been optimized by fitting to a large number of hydrographic parameters and tracers, including CFCs and natural radiocarbon. Production and export of POC is allowed to vary monthly, and the magnitudes of the monthly export fluxes are determined by fitting the model to satellite POC data as well as water column nutrient data using the adjoint method. Two cases have been investigated: (1) the production rate of POC is set to be proportional to export production EP and the seasonal changes are assumed sinusoidal (meridionally varying amplitude and phase) and (2) the POC production rate is linked to primary production rates (literature). Both cases were run with the same initial state and model settings, and show total cost function decreases of 12 and 95%, respectively. The POC misfit term alone decreased by 75 and 99%. The integrated annual global POC exports of the two cases are 9.9 Gt C/yr and 12.3 Gt C/yr, respectively. Overall, the remaining POC and

  10. Assimilating water column and satellite data for marine export production estimation

    NASA Astrophysics Data System (ADS)

    Yao, X.; Schlitzer, R.

    2013-09-01

    Recent advances in satellite retrieval methodology now allow for estimation of particular organic carbon (POC) concentration in ocean surface waters directly from satellite-based optical data. Because of the good coverage, these data reveal small-scale spatial and temporal concentration gradients and document the evolution of surface water POC as well as the underlying driving biogeochemical processes throughout the seasons. Water column nutrient data also reveal biogeochemical activity. However, because of the scarcity of data, the deduction of temporal changes of particle production and export is not possible in most parts of the ocean. Here we present first results from a new study combining both data streams, thereby exploiting the high spatio-temporal resolution of surface POC concentrations from satellite optical sensors with water column nutrient data having sparser coverage but providing information throughout the entire water column. We use a medium-resolution global model with steady-state 3-D circulation that has been optimized by fitting to a large number of hydrographic parameters and tracers, including CFCs and natural radiocarbon. Production and export of POC is allowed to vary monthly, and the magnitudes of the monthly export fluxes are determined by fitting the model to satellite POC data as well as water column nutrient data using the adjoint method. Two cases have been investigated: (1) the production rate of POC is set to be proportional to export production (EP) and the seasonal changes are assumed sinusoidal (meridionally varying amplitude and phase), and (2) the POC production rate is linked to primary production rates (literature). Both cases were run with the same initial state and model settings, and show total cost function decreases of 12 and 95%, respectively. The POC misfit term alone decreased by 75 and 99.8%. The integrated annual global POC exports of the two cases are 9.9 and 12.3 Gt C yr-1, respectively. Overall, the remaining POC

  11. Assimilating water column and satellite data for marine export production estimation

    NASA Astrophysics Data System (ADS)

    Yao, X.; Schlitzer, R.

    2013-03-01

    Recent advances in satellite retrieval methodology now allow estimation of particular organic carbon (POC) concentration in ocean surface waters directly from satellite-based optical data. Because of the good coverage these data reveal small-scale spatial and temporal concentration gradients and document the evolution of surface water POC as well as the underlying driving biogeochemical processes throughout the seasons. Water column nutrient data also reveal biogeochemical activity. However, because of the scarcity of data the deduction of temporal changes of particle production and export are not possible in most parts of the ocean. Here we present first results from a new study combining both data streams thereby exploiting the high spatio-temporal resolution of surface POC concentrations from satellite optical sensors with water column nutrient data having sparser coverage but providing information throughout the entire water column. We use a medium-resolution global model with steady-state 3-D circulation that has been optimized by fitting to a large number of hydrographic parameters and tracers, including CFCs and natural radiocarbon. Production and export of POC is allowed to vary monthly, and the magnitudes of the monthly export fluxes are determined by fitting the model to satellite POC data as well as water column nutrient data using the adjoint method. Two cases have been investigated: (1) the production rate of POC is set to be proportional to export production EP and the seasonal changes are assumed sinusoidal (meridionally varying amplitude and phase) and (2) the POC production rate is linked to primary production rates (literature). Both cases were run with the same initial state and model settings, and show total cost function decreases of 12 and 95%, respectively. The POC misfit term alone decreased by 75 and 99%. The integrated annual global POC exports of the two cases are 9.9 Gt C yr-1 and 12.3 Gt C yr-1, respectively. Overall, the remaining POC

  12. Water chemistry of a combined-cycle power plant's auxiliary equipment cooling system

    NASA Astrophysics Data System (ADS)

    Larin, B. M.; Korotkov, A. N.; Oparin, M. Yu.; Larin, A. B.

    2013-04-01

    Results from an analysis of methods aimed at reducing the corrosion rate of structural metal used in heat-transfer systems with water coolant are presented. Data from examination of the closed-circuit system for cooling the auxiliary mechanisms of a combined-cycle plant-based power unit and the results from adjustment of its water chemistry are given. A conclusion is drawn about the possibility of using a reagent prepared on the basis of sodium sulfite for reducing the corrosion rate when the loss of coolant is replenished with nondeaerated water.

  13. Parameterization of Middle Atmospheric Water Vapor Photochemistry for High-Altitude NWP and Data Assimilation

    DTIC Science & Technology

    2008-01-01

    develop fast, accurate parameterizations of strato - spheric ozone photochemistry (McCormack et al., 2004, 2006). MacKenzie and Harwood (2004...effect of the CHEM2D-H2O and ECMWF photochemistry parameterizations on strato - spheric water vapor, where the relevant photochemical time scales are much...conditions that lead to the formation of polar mesospheric clouds. The role of addi- tional physical processes such as molecular diffusion, which is not

  14. Safety analysis of a high temperature supercritical pressure light water cooled and moderated reactor

    SciTech Connect

    Ishiwatari, Y.; Oka, Y.; Koshizuka, S.

    2002-07-01

    A safety analysis code for a high temperature supercritical pressure light water cooled reactor (SCLWR-H) with water rods cooled by descending flow, SPRAT-DOWN, is developed. The hottest channel, a water rod, down comer, upper and lower plenums, feed pumps, etc. are modeled as junction of nodes. Partial of the feed water flows downward from the upper dome of the reactor pressure vessel to the water rods. The accidents analyzed here are total loss of feed water flow, feed water pump seizure, and control rods ejection. All the accidents satisfy the criteria. The accident event at which the maximum cladding temperature is the highest is total loss of feedwater flow. The transients analyzed here are loss of feed water heating, inadvertent start-up of an auxiliary water supply system, partial loss of feed water flow, loss of offsite power, loss of load, and abnormal withdrawal of control rods. All the transients satisfied the criteria. The transient event for which the maximum cladding temperature is the highest is control rod withdrawal at normal operation. The behavior of loss of load transient is different from that of BWR. The power does not increase because loss of flow occurs and the density change is small. The sensitivities of the system behavior to various parameters during transients and accidents are analyzed. The parameters having strong influence are the capacity of the auxiliary water supply system, the coast down time of the main feed water pumps, and the time delay of the main feed water pumps trip. The control rod reactivity also has strong influence. (authors)

  15. A practical application for the chemical treatment of Southern California`s reclaimed, Title 22 water for use as makeup water for recirculating cooling water systems

    SciTech Connect

    Zakrzewski, J.; Cosulich, J.; Bartling, E.

    1998-12-31

    Pilot cooling water studies conducted at a Southern California landfill/cogeneration station demonstrated a successful chemical treatment program for recirculating cooling water that used unnitrified, reclaimed, Title 22 water as the primary makeup water source. The constituents in the reclaimed water are supplied by variety of residential and waste water sources resulting in a water quality that may vary to a greater degree than domestic water supplies. This water contains high concentrations of orthophosphate, ammonia, chlorides and suspended solids. The impact of which, under cycled conditions is calcium orthophosphate scaling, high corrosion of yellow metal and mild steel, stress cracking of copper alloys and stainless steel and rapidly growing biological activity. A mobile cooling water testing laboratory with two pilot recirculating water systems modeled the cogeneration station`s cooling tower operating conditions and parameters. The tube and shell, tube side cooling heat exchangers were fitted with 443 admiralty, 90/10 copper nickel, 316 stainless steel and 1202 mild steel heat exchanger tubes. Coupons and Corrater electrodes were also installed. A chemical treatment program consisting of 60/40 AA/AMPS copolymer for scale, deposits and dispersion, sodium tolyltriazole for yellow metal corrosion, and a bromination program to control the biological activity was utilized in the pilot systems. Recirculating water orthophosphate concentrations reached levels of 70 mg/L as PO, and ammonia concentrations reached levels of 35 mg/L, as total NH3. The study successfully demonstrated a chemical treatment program to control scale and deposition, minimize admiralty, 90/10 copper nickel and carbon steel corrosion rates, prevent non-heat transfer yellow metal and stainless steel stress cracking, and control the biological activity in this high nutrient water.

  16. Spacesuit Water Membrane Evaporator; An Enhanced Evaporative Cooling Systems for the Advanced Extravehicular Mobility Unit Portable Life Support System

    NASA Technical Reports Server (NTRS)

    Bue, Grant C.; Makinen, Janice V.; Miller, Sean.; Campbell, Colin; Lynch, Bill; Vogel, Matt; Craft, Jesse; Petty, Brian

    2014-01-01

    Spacesuit Water Membrane Evaporator - Baseline heat rejection technology for the Portable Life Support System of the Advanced EMU center dot Replaces sublimator in the current EMU center dot Contamination insensitive center dot Can work with Lithium Chloride Absorber Radiator in Spacesuit Evaporator Absorber Radiator (SEAR) to reject heat and reuse evaporated water The Spacesuit Water Membrane Evaporator (SWME) is being developed to replace the sublimator for future generation spacesuits. Water in LCVG absorbs body heat while circulating center dot Warm water pumped through SWME center dot SWME evaporates water vapor, while maintaining liquid water - Cools water center dot Cooled water is then recirculated through LCVG. center dot LCVG water lost due to evaporation (cooling) is replaced from feedwater The Independent TCV Manifold reduces design complexity and manufacturing difficulty of the SWME End Cap. center dot The offset motor for the new BPV reduces the volume profile of the SWME by laying the motor flat on the End Cap alongside the TCV.

  17. Electric chiller buyer`s guide: Water-cooled centrifugal and screw chillers

    SciTech Connect

    Fryer, L.

    1995-06-01

    The phase-out of CFCs at the end of 1995 is driving increasing numbers of building owners to convert or replace their chillers with equipment that uses non-CFC refrigerants. Because chillers last for decades, the efficiency of the replacement equipment will have a lasting effect on the energy use, operating cost, and environmental impact of the over 25 percent of commercial floor space that is cooled by chillers, as well as the need for utility capacity. Each chiller is custom built, and many efficiency options are available. The lowest life cycle costs will be obtained by optimizing the cooling plant (including the cooling tower and chilled water distribution system) to match the year-round load profile of the building, not just its peak load. Careful sizing of replacement chillers can correct the oversizing that is so common, thereby reducing capital and operating costs. Significant savings may also be obtained by designing for the local climate, rather than basing chiller selection on the standard conditions assumed in most analyses. This report covers the models and features available in electric water-cooled centrifugal and screw chillers of 150 to 1,200 tons. In addition to full- and part-load efficiencies, it includes information on sizing, refrigerants, heat exchangers, adjustable-frequency drives, trade-offs between chiller efficiency and pumping power, staging of multiple chillers, maintenance, chiller testing, and utility program opportunities.

  18. In situ cooling with ice water for the easier removal of self-expanding nitinol stents

    PubMed Central

    Merkel, Daniel; Brinkmann, Eckhard; Wiens, Daniel; Derwahl, Karl-Michael

    2015-01-01

    Background: It is yet to be determined what effects temperature has on the properties of nitinol in order to simplify the process of removing nitinol self-expanding metal stents (SEMS). Materials and methods: We describe the procedure for removal of SEMS in a total of 11 cases with 9 patients. A study involving cooling of nitinol stents in situ with ice water just before their removal was attempted. Results: All stents were removed successfully. In partially covered and in fully covered stents, the stent rigidity was noticeably reduced following cooling. Stent removal was performed by inversion, which was achieved by pulling on the stent from its distal end. No adverse events were observed during this trial. Conclusion: The higher pliability of the stents after ice-water cooling facilitates stent removal. With this method, a mobilization of all stents by the invagination technique was achieved. The separation of the uncoated stent ends from the intestinal wall by the invagination technique, as well as the mucosal vasoconstriction resulting from the cooling, lead to an easier SEMS removal and may serve to prevent severe bleeding of the mucosal wall during this process. PMID:26134772

  19. Utilization of artificial recharged effluent as makeup water for industrial cooling system: corrosion and scaling.

    PubMed

    Wei, Liangliang; Qin, Kena; Zhao, Qingliang; Noguera, Daniel R; Xin, Ming; Liu, Chengcai; Keene, Natalie; Wang, Kun; Cui, Fuyi

    2016-01-01

    The secondary effluent from wastewater treatment plants was reused for industrial cooling water after pre-treatment with a laboratory-scale soil aquifer treatment (SAT) system. Up to a 95.3% removal efficiency for suspended solids (SS), 51.4% for chemical oxygen demand (COD), 32.1% for Cl(-) and 30.0% SO4(2-) were observed for the recharged secondary effluent after the SAT operation, which is essential for controlling scaling and corrosion during the cooling process. As compared to the secondary effluent, the reuse of the 1.5 m depth SAT effluent decreased the corrosion by 75.0%, in addition to a 55.1% decline of the scales/biofouling formation (with a compacted structure). The experimental results can satisfy the Chinese criterion of Design Criterion of the Industrial Circulating Cooling Water Treatment (GB 50050-95), and was more efficient than tertiary effluent which coagulated with ferric chloride. In addition, chemical structure of the scales/biofouling obtained from the cooling system was analyzed.

  20. Impact of operating conditions on cooling capacity for sorption systems using water as refrigerant

    NASA Astrophysics Data System (ADS)

    Tremeac, Brice; Giraud, Florine; Vallon, Pierrick

    2017-02-01

    The implementation of compact heat exchanger in sorption systems is a key factor to allow the development of these systems. The aim of this paper is to develop a statistical model with a design of experiment (DOE) methodology and use dimensionless number to evaluate and understand the influence of the height of refrigerant liquid and secondary fluid inlet temperature on cooling capacity of a compact pate-type evaporator for sorption systems working near vacuum pressure. For this purpose, an experimental campaign was conducted on a small adsorption test bench using 13X/water as working couple. Cooling capacities from 640 to 2000 W were measured. The DOE is a Doelhert type with two parameters: the inlet secondary fluid temperature (from 10 to 21 °C) and the filing level of refrigerant in the evaporator (from 6 to 24 cm). Thanks to the exploitation of the mathematical model obtained, optimal points under different constraints were found. A maximum cooling capacity of 2021 +/-75 W in the entire experimental field was predicted for a secondary fluid inlet temperature of 25°C and a height of liquid level of 19.2 cm. Bond number and modified Jacob number per the ratio Psat/Ptriple were analyzed. The dimensionless numbers are correlated to the cooling capacity as a first step for designing compact plate-type evaporator for adsorption systems using water as refrigerant.

  1. Heating and cooling of municipal buildings with waste heat from ground water

    SciTech Connect

    Morgan, D.S.; Hochgraf, J.

    1980-10-01

    The feasibility of using waste heat from municipal water wells to replace natural gas for heating of the City Hall, Fire Station, and Community Hall in Wilmer, Texas was studied. At present, the 120/sup 0/F well water is cooled by dissipating the excess heat through evaporative cooling towers before entering the distribution system. The objective of the study was to determine the pumping cycle of the well and determine the amount of available heat from the water for a specified period. This data were correlated with the heating and cooling demand of the City's buildings, and a conceptual heat recovery system will be prepared. The system will use part or all of the excess heat from the water to heat the buildings, thereby eliminating the use of natural gas. The proposed geothermal retrofit of the existing natural gas heating system is not economical because the savings in natural gas does not offset the capital cost of the new equipment and the annual operating and maintenance costs. The fuel savings and power costs are a virtual trade-off over the 25-year period. The installation and operation of the system was estimated to cost $105,000 for 25 years which is an unamortized expense. In conclusion, retrofitting the City of Wilmer's municipal buildings is not feasible based on the economic analysis and fiscal projections as presented.

  2. Passive decay heat removal system for water-cooled nuclear reactors

    DOEpatents

    Forsberg, Charles W.

    1991-01-01

    A passive decay-heat removal system for a water-cooled nuclear reactor employs a closed heat transfer loop having heat-exchanging coils inside an open-topped, insulated box located inside the reactor vessel, below its normal water level, in communication with a condenser located outside of containment and exposed to the atmosphere. The heat transfer loop is located such that the evaporator is in a position where, when the water level drops in the reactor, it will become exposed to steam. Vapor produced in the evaporator passes upward to the condenser above the normal water level. In operation, condensation in the condenser removes heat from the system, and the condensed liquid is returned to the evaporator. The system is disposed such that during normal reactor operations where the water level is at its usual position, very little heat will be removed from the system, but during emergency, low water level conditions, substantial amounts of decay heat will be removed.

  3. Multi-Model Assessment of Global Hydropower and Cooling Water Discharge Potential Under Climate Change

    NASA Technical Reports Server (NTRS)

    van Vliet, M. T. H.; van Beek, L. P. H.; Eisener, S.; Wada, Y.; Bierkens, M. F. P.

    2016-01-01

    Worldwide, 98% of total electricity is currently produced by thermoelectric power and hydropower. Climate change is expected to directly impact electricity supply, in terms of both water availability for hydropower generation and cooling water usage for thermoelectric power. Improved understanding of how climate change may impact the availability and temperature of water resources is therefore of major importance. Here we use a multi-model ensemble to show the potential impacts of climate change on global hydropower and cooling water discharge potential. For the first time, combined projections of streamflow and water temperature were produced with three global hydrological models (GHMs) to account for uncertainties in the structure and parametrization of these GHMs in both water availability and water temperature. The GHMs were forced with bias-corrected output of five general circulation models (GCMs) for both the lowest and highest representative concentration pathways (RCP2.6 and RCP8.5). The ensemble projections of streamflow and water temperature were then used to quantify impacts on gross hydropower potential and cooling water discharge capacity of rivers worldwide. We show that global gross hydropower potential is expected to increase between +2.4% (GCM-GHM ensemble mean for RCP 2.6) and +6.3% (RCP 8.5) for the 2080s compared to 1971-2000. The strongest increases in hydropower potential are expected for Central Africa, India, central Asia and the northern high-latitudes, with 18-33% of the world population living in these areas by the 2080s. Global mean cooling water discharge capacity is projected to decrease by 4.5-15% (2080s). The largest reductions are found for the United States, Europe, eastern Asia, and southern parts of South America, Africa and Australia, where strong water temperature increases are projected combined with reductions in mean annual streamflow. These regions are expected to affect 11-14% (for RCP2.6 and the shared socioeconomic

  4. Multi-Model Assessment of Global Hydropower and Cooling Water Discharge Potential Under Climate Change

    NASA Technical Reports Server (NTRS)

    van Vliet, M. T. H.; van Beek, L. P. H.; Eisener, S.; Wada, Y.; Bierkens, M. F. P.

    2016-01-01

    Worldwide, 98% of total electricity is currently produced by thermoelectric power and hydropower. Climate change is expected to directly impact electricity supply, in terms of both water availability for hydropower generation and cooling water usage for thermoelectric power. Improved understanding of how climate change may impact the availability and temperature of water resources is therefore of major importance. Here we use a multi-model ensemble to show the potential impacts of climate change on global hydropower and cooling water discharge potential. For the first time, combined projections of streamflow and water temperature were produced with three global hydrological models (GHMs) to account for uncertainties in the structure and parametrization of these GHMs in both water availability and water temperature. The GHMs were forced with bias-corrected output of five general circulation models (GCMs) for both the lowest and highest representative concentration pathways (RCP2.6 and RCP8.5). The ensemble projections of streamflow and water temperature were then used to quantify impacts on gross hydropower potential and cooling water discharge capacity of rivers worldwide. We show that global gross hydropower potential is expected to increase between +2.4% (GCM-GHM ensemble mean for RCP 2.6) and +6.3% (RCP 8.5) for the 2080s compared to 1971-2000. The strongest increases in hydropower potential are expected for Central Africa, India, central Asia and the northern high-latitudes, with 18-33% of the world population living in these areas by the 2080s. Global mean cooling water discharge capacity is projected to decrease by 4.5-15% (2080s). The largest reductions are found for the United States, Europe, eastern Asia, and southern parts of South America, Africa and Australia, where strong water temperature increases are projected combined with reductions in mean annual streamflow. These regions are expected to affect 11-14% (for RCP2.6 and the shared socioeconomic

  5. Microcystin-tolerant Rhizobium protects plants and improves nitrogen assimilation in Vicia faba irrigated with microcystin-containing waters.

    PubMed

    Lahrouni, Majida; Oufdou, Khalid; El Khalloufi, Fatima; Benidire, Loubna; Albert, Susann; Göttfert, Michael; Caviedes, Miguel A; Rodriguez-Llorente, Ignacio D; Oudra, Brahim; Pajuelo, Eloísa

    2016-05-01

    Irrigation of crops with microcystins (MCs)-containing waters-due to cyanobacterial blooms-affects plant productivity and could be a way for these potent toxins entering the food chain. This study was performed to establish whether MC-tolerant rhizobia could benefit growth, nodulation, and nitrogen metabolism of faba bean plants irrigated with MC-containing waters. For that, three different rhizobial strains-with different sensitivity toward MCs-were used: RhOF96 (most MC-sensitive strain), RhOF125 (most MC-tolerant strain), or Vicz1.1 (reference strain). As a control, plants grown without rhizobia and fertilized by NH4NO3 were included in the study. MC exposure decreased roots (30-37 %) and shoots (up to 15 %) dry weights in un-inoculated plants, whereas inoculation with rhizobia protects plants toward the toxic effects of MCs. Nodulation and nitrogen content were significantly impaired by MCs, with the exception of plants inoculated with the most tolerant strain RhOF125. In order to deep into the effect of inoculation on nitrogen metabolism, the nitrogen assimilatory enzymes (glutamine synthetase (GS) and glutamate synthase (GOGAT)) were investigated: Fertilized plants showed decreased levels (15-30 %) of these enzymes, both in shoots and roots. By contrast, inoculated plants retained the levels of these enzymes in shoots and roots, as well as the levels of NADH-GOGAT activity in nodules. We conclude that the microcystin-tolerant Rhizobium protects faba bean plants and improves nitrogen assimilation when grown in the presence of MCs.

  6. Integrating Remote Sensing Information Into A Distributed Hydrological Model for Improving Water Budget Predictions in Large-scale Basins through Data Assimilation.

    PubMed

    Qin, Changbo; Jia, Yangwen; Su, Z; Zhou, Zuhao; Qiu, Yaqin; Suhui, Shen

    2008-07-29

    This paper investigates whether remote sensing evapotranspiration estimates can be integrated by means of data assimilation into a distributed hydrological model for improving the predictions of spatial water distribution over a large river basin with an area of 317,800 km2. A series of available MODIS satellite images over the Haihe River basin in China are used for the year 2005. Evapotranspiration is retrieved from these 1×1 km resolution images using the SEBS (Surface Energy Balance System) algorithm. The physically-based distributed model WEP-L (Water and Energy transfer Process in Large river basins) is used to compute the water balance of the Haihe River basin in the same year. Comparison between model-derived and remote sensing retrieval basin-averaged evapotranspiration estimates shows a good piecewise linear relationship, but their spatial distribution within the Haihe basin is different. The remote sensing derived evapotranspiration shows variability at finer scales. An extended Kalman filter (EKF) data assimilation algorithm, suitable for non-linear problems, is used. Assimilation results indicate that remote sensing observations have a potentially important role in providing spatial information to the assimilation system for the spatially optical hydrological parameterization of the model. This is especially important for large basins, such as the Haihe River basin in this study. Combining and integrating the capabilities of and information from model simulation and remote sensing techniques may provide the best spatial and temporal characteristics for hydrological states/fluxes, and would be both appealing and necessary for improving our knowledge of fundamental hydrological processes and for addressing important water resource management problems.

  7. Integrating Remote Sensing Information Into A Distributed Hydrological Model for Improving Water Budget Predictions in Large-scale Basins through Data Assimilation

    PubMed Central

    Qin, Changbo; Jia, Yangwen; Su, Z.(Bob); Zhou, Zuhao; Qiu, Yaqin; Suhui, Shen

    2008-01-01

    This paper investigates whether remote sensing evapotranspiration estimates can be integrated by means of data assimilation into a distributed hydrological model for improving the predictions of spatial water distribution over a large river basin with an area of 317,800 km2. A series of available MODIS satellite images over the Haihe River basin in China are used for the year 2005. Evapotranspiration is retrieved from these 1×1 km resolution images using the SEBS (Surface Energy Balance System) algorithm. The physically-based distributed model WEP-L (Water and Energy transfer Process in Large river basins) is used to compute the water balance of the Haihe River basin in the same year. Comparison between model-derived and remote sensing retrieval basin-averaged evapotranspiration estimates shows a good piecewise linear relationship, but their spatial distribution within the Haihe basin is different. The remote sensing derived evapotranspiration shows variability at finer scales. An extended Kalman filter (EKF) data assimilation algorithm, suitable for non-linear problems, is used. Assimilation results indicate that remote sensing observations have a potentially important role in providing spatial information to the assimilation system for the spatially optical hydrological parameterization of the model. This is especially important for large basins, such as the Haihe River basin in this study. Combining and integrating the capabilities of and information from model simulation and remote sensing techniques may provide the best spatial and temporal characteristics for hydrological states/fluxes, and would be both appealing and necessary for improving our knowledge of fundamental hydrological processes and for addressing important water resource management problems. PMID:27879946

  8. Water-cooled target modules for steady-state operation of the W7-X divertor

    NASA Astrophysics Data System (ADS)

    Boscary, J.; Greuner, H.; Czerwinski, M.; Mendelevitch, B.; Pfefferle, K.; Renner, H.

    2003-09-01

    The stellarator WENDELSTEIN 7-X (W7-X) includes water-cooled plasma facing components (PFCs) to allow steady-state operation and to provide an efficient particle and power exhaust up to 10 MW for a maximum pulse duration of 30 min. Ten divertor units are arranged along the helical edge of the fivefold periodic plasma column. The three-dimensional shape and positioning of the target surfaces are optimized to address physics issues for a wide range of experimental parameters, which influence the topology of the boundary. The three-dimensional target surfaces are reproduced by a series of consecutive plane target elements as a set of parallel water-cooled elements positioned onto the frameworks of target modules. The design and arrangement of target modules and elements are described.

  9. Prospects for development of an innovative water-cooled nuclear reactor for supercritical parameters of coolant

    NASA Astrophysics Data System (ADS)

    Kalyakin, S. G.; Kirillov, P. L.; Baranaev, Yu. D.; Glebov, A. P.; Bogoslovskaya, G. P.; Nikitenko, M. P.; Makhin, V. M.; Churkin, A. N.

    2014-08-01

    The state of nuclear power engineering as of February 1, 2014 and the accomplished elaborations of a supercritical-pressure water-cooled reactor are briefly reviewed, and the prospects of this new project are discussed based on this review. The new project rests on the experience gained from the development and operation of stationary water-cooled reactor plants, including VVERs, PWRs, BWRs, and RBMKs (their combined service life totals more than 15 000 reactor-years), and long-term experience gained around the world with operation of thermal power plants the turbines of which are driven by steam with supercritical and ultrasupercritical parameters. The advantages of such reactor are pointed out together with the scientific-technical problems that need to be solved during further development of such installations. The knowledge gained for the last decade makes it possible to refine the concept and to commence the work on designing an experimental small-capacity reactor.

  10. Fishing for isotopes in the Brookhaven Lab Isotope Producer (BLIP) cooling water

    SciTech Connect

    Fitzsimmons, Jonathan

    2016-04-29

    Be-7 has been used in environmental studies; the isotope is produced during BLIP irradiations and accumulates in the 320 gallons of cooling water. Be-7 has a 53.24 day half-life, so the optimal production/purification time is at the end of the BLIP run season. To purify Be-7 fifteen to twenty gallons of BLIP cooling water are removed and pumped through ion exchange columns that retain Be-7. This labor intensive approach captures ~15 mCi of Be-7, but the solution requires further purification. The method can lead to increased radiation exposure to staff. The ideal way to capture isotopes from large volumes is to reach in to the solution and selectively pull out the desired isotope. It is a lot like fishing.

  11. Questioning the Mpemba effect: hot water does not cool more quickly than cold

    PubMed Central

    Burridge, Henry C.; Linden, Paul F.

    2016-01-01

    The Mpemba effect is the name given to the assertion that it is quicker to cool water to a given temperature when the initial temperature is higher. This assertion seems counter-intuitive and yet references to the effect go back at least to the writings of Aristotle. Indeed, at first thought one might consider the effect to breach fundamental thermodynamic laws, but we show that this is not the case. We go on to examine the available evidence for the Mpemba effect and carry out our own experiments by cooling water in carefully controlled conditions. We conclude, somewhat sadly, that there is no evidence to support meaningful observations of the Mpemba effect. PMID:27883034

  12. Temperature dynamics and control of a water-cooled fuel cell stack

    NASA Astrophysics Data System (ADS)

    O'Keefe, Daniel; El-Sharkh, M. Y.; Telotte, John C.; Palanki, Srinivas

    2014-06-01

    In this paper, a time-varying proportional-integral (PI) controller is designed for controlling the temperature of a water-cooled 5 kW hydrogen fuel cell stack. This controller is designed using a mathematical model for the stack temperature, which is derived using basic chemical engineering material and energy balances. The controller affects the stack temperature by changing the flow rate of cooling water that passes across the stack. The model is then analyzed using a number of power demand profiles to determine the effectiveness of the controller. The results show that a time-varying PI controller is adequate for maintaining the stack temperature within 5 K of the target point.

  13. Neutronics Analysis of Water-Cooled Ceramic Breeder Blanket for CFETR

    NASA Astrophysics Data System (ADS)

    Zhu, Qingjun; Li, Jia; Liu, Songlin

    2016-07-01

    In order to investigate the nuclear response to the water-cooled ceramic breeder blanket models for CFETR, a detailed 3D neutronics model with 22.5° torus sector was developed based on the integrated geometry of CFETR, including heterogeneous WCCB blanket models, shield, divertor, vacuum vessel, toroidal and poloidal magnets, and ports. Using the Monte Carlo N-Particle Transport Code MCNP5 and IAEA Fusion Evaluated Nuclear Data Library FENDL2.1, the neutronics analyses were performed. The neutron wall loading, tritium breeding ratio, the nuclear heating, neutron-induced atomic displacement damage, and gas production were determined. The results indicate that the global TBR of no less than 1.2 will be a big challenge for the water-cooled ceramic breeder blanket for CFETR. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB108004, 2014GB122000, and 2014GB119000), and National Natural Science Foundation of China (No. 11175207)

  14. High power testing of water-cooled waveguide for ITER-like ECH transmission lines

    NASA Astrophysics Data System (ADS)

    Anderson, J. P.; Doane, J. L.; Grunloh, H. J.; O'Neill, R. C.; Ikeda, R.; Oda, Y.; Takahashi, K.; Sakamoto, K.

    2017-05-01

    The results of high power testing of new water-cooled ECH waveguide components for ITER are presented. The components are a precision-coupled 4.2 m waveguide assembly, a short expansion joint, and water-cooled waveguide for gyrotron commissioning. The testing was conducted at the QST Naka Fusion Institute using gyrotron pulses of 450 kW at 170 GHz for 300 s. Analysis shows that the power absorbed per unit length for the various waveguide components are dependent on location in the transmission line with respect to high order mode generators, such as miter bends. Additionally, larger-than-expected reflections from the load led to high absorption levels in the transmission line.

  15. Prevalence of antibiotic-resistant bacteria in a lake for the storage of reclaimed water before and after usage as cooling water.

    PubMed

    Pang, Yu-Chen; Xi, Jin-Ying; Li, Guo-Qiang; Shi, Xiao-Jie; Hu, Hong-Ying

    2015-06-01

    Wastewater reclamation and reuse is a promising way to relieve water scarcity by substituting for natural water consumption by industrial cooling. However, health concerns regarding cooling water originating from reclaimed water are increasing because an abundance of antibiotic-resistant bacteria (ARB) has been detected in reclaimed water. To assess the potential increase of ARB risks in reclaimed water after reuse for industrial cooling, the prevalence of six types of ARB was investigated in water and sediment samples from Lake Gaobeidian, which serves as an artificial circular storage reservoir for reclaimed water for cooling reuse. The effect of treated wastewater and cooling water drainage on the ARB distribution in water and sediment samples was also studied. The results showed that the concentration levels of six types of ARB in lake water samples were as high as those in treated wastewater. The annual median concentrations of total heterotrophic bacteria (HPC) and ARB in discharged cooling water after usage were 0.6-log and 0.4-log higher than those in treated wastewater and the cooling water intake site, respectively, indicating that the process of cooling water usage enhanced the proliferation of HPC and consequently increased the concentrations of ARB. Furthermore, the percentages of penicillin-, ampicillin-, and cephalothin-resistant bacteria in water were 30-57%, 36-48%, and 23-40% higher than those in sediment, respectively. However, the proportions of chloramphenicol-resistant bacteria in water were 35-85% lower than those in sediment. Quantitative evaluation of antibiotic resistance showed that HPC in water had a significant tolerance to penicillin and chloramphenicol, with 50% inhibitory concentrations reaching 22.90 mg L(-1) and 29.11 mg L(-1), respectively.

  16. Mycorrhizal colonisation and P-supplement effects on N uptake and N assimilation in perennial ryegrass under well-watered and drought-stressed conditions.

    PubMed

    Lee, Bok-Rye; Muneer, Sowbiya; Avice, Jean-Christophe; Jung, Woo-Jin; Kim, Tae-Hwan

    2012-10-01

    To compare the effect of arbuscular mycorrhiza (AM) and P-supplement on N uptake and N assimilation under well-watered or drought-stressed conditions, Glomus intraradices-colonised, P-supplemented non-mycorrhizal (P) and non-mycorrhizal (control) plants of Lolium perenne were exposed to 12 days of water treatment. Leaf water potential (Ψ (w)), photosynthetic ability, and N and P nutritional status were measured at the beginning (day 0) and end (day 12) of water treatment. N absorption, amino acid and protein synthesis were quantified using the isotopic tracer (15)N at day 12. Under well-watered conditions, growth response and physiological parameters were similar in AM and P plants, as compared to controls. Drought (10% water) significantly decreased these parameters in all three treatments. As compared to control plants, the negative impact of water deficit on the Ψ (w), photosynthesis, biomass, and N and P content was highly alleviated in AM plants, while only slightly improved or remained the same level in P plants. The effect of AM symbiosis on N absorption and N assimilation was greater than that of the P supplement under well-watered and drought-stressed conditions, and this effect was highly enhanced under drought-stressed conditions. At terminal drought stress on day 12, the effect of AM colonisation on de novo synthesis of amino acids and proteins was 4.4- and 4.8-fold higher than that of the P supplement. These results indicate that the AM symbiosis plays an integrative role in N nutrition by alleviating the negative impacts of drought on N or P uptake and N assimilation, whereas the efficiency of a direct P supplement is very limited under drought-stressed conditions.

  17. Water-Cooled Data Center Packs More Power Per Rack | Poster

    Cancer.gov

    By Frank Blanchard and Ken Michaels, Staff Writers Behind each tall, black computer rack in the data center at the Advanced Technology Research Facility (ATRF) is something both strangely familiar and oddly out of place: It looks like a radiator. The back door of each cabinet is gridded with the coils of the Liebert cooling system, which circulates chilled water to remove heat generated by the high-speed, high-capacity, fault-tolerant equipment.

  18. Development and selection of heat-resistant tool steels for water-cooled dies

    NASA Astrophysics Data System (ADS)

    Kremney, L. S.; Zabezhinskii, A. Ya.

    1980-02-01

    Alloying and heat treatment of tool steels for water-cooled dies to improve the service life in high-speed automatic presses must ensure: 1) The lowest but still sufficient level of hardening during precipitation hardening; 2) the smallest amount of carbide not dissolved during quenching; 3) prevention of the decomposition of martensite in grain boundaries during tempering; 4) a structure of lath martensite.

  19. Low Maintenance Water Treatment for Heating and Cooling Systems: Review of Technologies and Guidelines for Implementation

    DTIC Science & Technology

    2007-09-01

    formulation will be in preventing scale build-up during temporary upsets in water chemistry . The first class of polymers that found widespread use and...tetrakis (hydroxymethyl) phosphonium sulfate (THPS), the winner of the 1999 President’s Green Chemistry Challenge Award. Some of these compounds can...Open cooling system chemistry can change very rapidly, so control of blowdown and chemical feed (including biocides) needs to be as auto- mated as

  20. Topical report : NSTF facilities plan for water-cooled VHTR RCCS : normal operational tests.

    SciTech Connect

    Farmer, M. T.; Kilsdonk, D. J.; Tzanos, C. P.; Lomperski, S.; Aeschlimann, R. W.; Nuclear Engineering Division

    2006-09-01

    As part of the Department of Energy (DOE) Generation IV roadmapping activity, the gas-cooled Very High Temperature Reactor (VHTR) has been selected as the principal concept for hydrogen production and other process-heat applications such as district heating and potable water production. On this basis, the DOE has selected the VHTR for additional R&D with the ultimate goal of demonstrating emission-free electricity and hydrogen production with this advanced reactor concept.

  1. Water-Cooled Data Center Packs More Power Per Rack | Poster

    Cancer.gov

    By Frank Blanchard and Ken Michaels, Staff Writers Behind each tall, black computer rack in the data center at the Advanced Technology Research Facility (ATRF) is something both strangely familiar and oddly out of place: It looks like a radiator. The back door of each cabinet is gridded with the coils of the Liebert cooling system, which circulates chilled water to remove heat generated by the high-speed, high-capacity, fault-tolerant equipment.

  2. Analysis of water management at a closed cooling system of a power plant

    NASA Astrophysics Data System (ADS)

    Regucki, P.; Engler, B.; Szeliga, Z.

    2016-10-01

    The paper presents a mathematical model describing the changes in SO4 2- ions concentration in a closed system of cooling water circulation in a professional power plant due to the new restrictions posed on industrial emissions by EU and Polish government regulations [1]. Analyzing the behavior of the numerical solutions of the model Authors could determine the optimal volumetric flow rate of wastewater depending on the current configuration of operating power units in a professional power plant.

  3. TRMM Data Assimilation at NASA

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.; Zhang, Sara Q.; Olson, William S.

    1999-01-01

    Current global analyses contain significant errors in primary hydrological fields such as precipitation, evaporation, and related cloud and moisture in the tropics. Work has been underway at NASA's Data Assimilation Office to explore the use of Tropical Rainfall Measuring Mission (TRMM) and Special Sensor Microwave Imager (SSM/I)-derived rainfall and total precipitable water (TPW) data in global data assimilation to directly constrain these hydrological parameters. We found that assimilating these data types improves not only the precipitation and moisture estimates but also key climate parameters directly linked to convection such as the outgoing longwave radiation, clouds, and the large-scale circulation in the tropics. We will present results showing that assimilating TRMM and SSM/I 6-hour averaged rain rates and TPW estimates significantly reduces the state-dependent systematic errors in assimilated products. Specifically, rainfall assimilation improves cloud and latent heating distributions, which, in turn, improves the cloudy-sky radiation and the large-scale circulation, while TPW assimilation reduces moisture biases to improve radiation in clear-sky regions. Rainfall and TPW assimilation also improves tropical forecasts beyond I day.

  4. Analytical study of a microfludic DNA amplification chip using water cooling effect.

    PubMed

    Chen, Jyh Jian; Shen, Chia Ming; Ko, Yu Wei

    2013-04-01

    A novel continuous-flow polymerase chain reaction (PCR) chip has been analyzed in our work. Two temperature zones are controlled by two external controllers and the other temperature zone at the chip center is controlled by the flow rate of the fluid inside a channel under the glass chip. By employing a water cooling channel at the chip center, the sequence of denaturation, annealing, and extension can be created due to the forced convection effect. The required annealing temperature of PCR less than 313 K can also be demonstrated in this chip. The Poly(methyl methacrylate) (PMMA) cooling channel with the thin aluminum cover is utilized to enhance the temperature uniformity. The size of this chip is 76 mm × 26 mm × 3 mm. This device represents the first demonstration of water cooling thermocycling within continuous-flow PCR microfluidics. The commercial software CFD-ACE+(TM) is utilized to determine the distances between the heating assemblies within the chip. We investigate the influences of various chip materials, operational parameters of the cooling channel and geometric parameters of the chip on the temperature uniformity on the chip surface. Concerning the temperature uniformity of the working zones and the lowest temperature at the annealing zone, the air gap spacing of 1 mm and the cooling channel thicknesses of 1 mm of the PMMA channel with an aluminum cover are recommended in our design. The hydrophobic surface of the PDMS channel was modified by filling it with 20 % Tween 20 solution and then adding bovine serum albumin (BSA) solution to the PCR mixture. DNA fragments with different lengths (372 bp and 478 bp) are successfully amplified with the device.

  5. RAMI Analysis for Designing and Optimizing Tokamak Cooling Water System (TCWS) for the ITER's Fusion Reactor

    SciTech Connect

    Ferrada, Juan J; Reiersen, Wayne T

    2011-01-01

    U.S.-ITER is responsible for the design, engineering, and procurement of the Tokamak Cooling Water System (TCWS). TCWS is designed to provide cooling and baking for client systems that include the first wall/blanket, vacuum vessel, divertor, and neutral beam injector. Additional operations that support these primary functions include chemical control of water provided to client systems, draining and drying for maintenance, and leak detection/localization. TCWS interfaces with 27 systems including the secondary cooling system, which rejects this heat to the environment. TCWS transfers heat generated in the Tokamak during nominal pulsed operation - 850 MW at up to 150 C and 4.2 MPa water pressure. Impurities are diffused from in-vessel components and the vacuum vessel by water baking at 200-240 C at up to 4.4 MPa. TCWS is complex because it serves vital functions for four primary clients whose performance is critical to ITER's success and interfaces with more than 20 additional ITER systems. Conceptual design of this one-of-a-kind cooling system has been completed; however, several issues remain that must be resolved before moving to the next stage of the design process. The 2004 baseline design indicated cooling loops that have no fault tolerance for component failures. During plasma operation, each cooling loop relies on a single pump, a single pressurizer, and one heat exchanger. Consequently, failure of any of these would render TCWS inoperable, resulting in plasma shutdown. The application of reliability, availability, maintainability, and inspectability (RAMI) tools during the different stages of TCWS design is crucial for optimization purposes and for maintaining compliance with project requirements. RAMI analysis will indicate appropriate equipment redundancy that provides graceful degradation in the event of an equipment failure. This analysis helps demonstrate that using proven, commercially available equipment is better than using custom-designed equipment

  6. Effects of Solution Hydrodynamics on Corrosion Inhibition of Steel by Citric Acid in Cooling Water

    NASA Astrophysics Data System (ADS)

    Ashassi-Sorkhabi, H.; Asghari, E.; Mohammadi, M.

    2014-08-01

    Corrosion is a major problem in cooling water systems, which is often controlled using corrosion inhibitors. Solution hydrodynamics is one of the factors affecting corrosion inhibition of metals in these systems. The present work focuses on the study of the combined effects of citric acid concentration (as a green corrosion inhibitor) and fluid flow on corrosion of steel in simulated cooling water. Electrochemical techniques including Tafel polarization and electrochemical impedance spectroscopy were used for corrosion studies. Laminar flow was simulated using a rotating disk electrode. The effects of solution hydrodynamics on inhibition performance of citric acid were discussed. The citric acid showed low inhibition performance in quiescent solution; however, when the electrode rotated at 200 rpm, inhibition efficiency increased remarkably. It was attributed mainly to the acceleration of inhibitor mass transport toward metal surface. The efficiencies were then decreased at higher rotation speeds due to enhanced wall shear stresses on metal surface and separation of adsorbed inhibitor molecules. This article is first part of authors' attempts in designing green inhibitor formulations for industrial cooling water. Citric acid showed acceptable corrosion inhibition in low rotation rates; thus, it can be used as a green additive to the corrosion inhibitor formulations.

  7. State waste discharge permit application 400 Area secondary cooling water. Revision 2

    SciTech Connect

    1996-01-01

    This document constitutes the Washington Administrative Code 173-216 State Waste Discharge Permit Application that serves as interim compliance as required by Consent Order DE 91NM-177, for the 400 Area Secondary Cooling Water stream. As part of the Hanford Federal Facility Agreement and Consent Order negotiations, the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site that affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173-216 of the Washington Administrative Code, the State Waste Discharge Permitting Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order DE 91NM-177. The Consent Order DE 91NM-177 requires a series of permitting activities for liquid effluent discharges. Based upon compositional and flow rate characteristics, liquid effluent streams on the Hanford Site have been categorized into Phase 1, Phase 2, and Miscellaneous streams. This document only addresses the 400 Area Secondary Cooling Water stream, which has been identified as a Phase 2 stream. The 400 Area Secondary Cooling Water stream includes contribution streams from the Fuels and Materials Examination Facility, the Maintenance and Storage Facility, the 481-A pump house, and the Fast Flux Test Facility.

  8. Outbreak of legionnaires' disease from a cooling water system in a power station.

    PubMed

    Morton, S; Bartlett, C L; Bibby, L F; Hutchinson, D N; Dyer, J V; Dennis, P J

    1986-09-01

    In September and October 1981 six cases of pneumonia occurred among men working in a power station under construction. Three were identified as cases of legionella pneumonia and two others had serology suggestive of legionella infection. In a sample of 92 men from the site 10 had low levels of antibodies to legionella; a similar sample of men working on an adjacent site showed none with positive serology. In a case control study it was found that cases of pneumonia were more likely than controls to have worked on a part of the site where four small capacity cooling towers were located. Legionella pneumophila serogroup 1 was isolated from the water systems of these four towers but was not found in samples from any other cooling towers or hot or cold water outlets on the site. It would appear that there was airborne spread of the organism from these cooling water systems which had not received conventional treatment to inhibit corrosion and organic growth. This is the first outbreak of legionnaires' disease to be recorded in an industrial setting in the United Kingdom. No cases of legionella infection have occurred on the site since the introduction of control measures.

  9. Outbreak of legionnaires' disease from a cooling water system in a power station.

    PubMed Central

    Morton, S; Bartlett, C L; Bibby, L F; Hutchinson, D N; Dyer, J V; Dennis, P J

    1986-01-01

    In September and October 1981 six cases of pneumonia occurred among men working in a power station under construction. Three were identified as cases of legionella pneumonia and two others had serology suggestive of legionella infection. In a sample of 92 men from the site 10 had low levels of antibodies to legionella; a similar sample of men working on an adjacent site showed none with positive serology. In a case control study it was found that cases of pneumonia were more likely than controls to have worked on a part of the site where four small capacity cooling towers were located. Legionella pneumophila serogroup 1 was isolated from the water systems of these four towers but was not found in samples from any other cooling towers or hot or cold water outlets on the site. It would appear that there was airborne spread of the organism from these cooling water systems which had not received conventional treatment to inhibit corrosion and organic growth. This is the first outbreak of legionnaires' disease to be recorded in an industrial setting in the United Kingdom. No cases of legionella infection have occurred on the site since the introduction of control measures. PMID:3756116

  10. Comprehensive Cooling Water Study: Volume 6, Federally endangered species, Savannah River Plant: Final report

    SciTech Connect

    Mackey, H.E.

    1987-09-01

    The Comprehensive Cooling Water Study (CCWS) was initiated in 1983 to evaluate the environmental effects of the intake and release of cooling water on the structure and function of aquatic ecosystems at the Savannah River Plant. The initial report described the results from the first year of the study. This document is the final report and concludes the program. The report comprises eight volumes. The Endangered Species Act requires that Federal agencies use their authorities to conduct programs for the conservation of endangered and threatened species and to ensure that agency actions do not jeopardize the continued existence of or result in the destruction or adverse modification of critical habitat of protected species. Those Federally endangered or threatened species that occur on the Savannah River Plant (SRP) include the American alligator, the red-cockaded woodpecker, the shortnose sturgeon, the wood stork, and the bald eagle. Of these species, the alligator, sturgeon, wood stork, and the bald eagle are likely to be affected directly and/or indirectly by the intake or release of cooling water at the SRP. 81 refs., 76 figs., 35 tabs.

  11. [Cool/Hot target effect of the water fog infrared stealth].

    PubMed

    Du, Yong-cheng; Yang, Li; Zhang, Shi-cheng; Yang, Zhen; Hu, Shuang-xi

    2012-08-01

    Artificial spray fog will come into being cool target because of the strong evaporation and convection but weak radiation heat flux, when it is used for defence of infrared imaging guided missile. Also, when it is the contrary condition, the water fog will come into being hot target. In order to open out the phenomenon particularly, a math model which can account for the cool/hot effect produced by water fog shielding the thermal radiation is established by coupling the calculation of radiation transfer equation and energy conversation equation, based on the Mie theory. This model is proved to be accurate in comparison with the Monte-Carlo method and Lambert-Beer' law. The water fog is seemed as absorbing, emitting and anisotropic scattering medium, and the medium radiation, multiple scattering, target radiation flux, and environment influence such as the conductivity, convection turbulent heat diffusion and evaporation is calculated. The phenomenon of cool/hot target effect can be shown in detail with this model.

  12. Systems design of direct-cycle supercritical-water-cooled fast reactors

    SciTech Connect

    Oka, Yoshiaki; Koshizuka, Seiichi; Jevremovic, Tatjana; Okano, Yashushi

    1995-01-01

    The system design of a direct-cycle supercritical-water-cooled fast reactor is presented. The supercritical water does not exhibit a change of phase. the recirculation system, steam separator, and dryer of a boiling water reactor (BWR) are unnecessary. Roughly speaking, the reactor pressure vessel and control rods are similar to those of a pressurized water reactor, the containment and emergency core cooling system are similar to a BWR, and the balance of plant is similar to a supercritical-pressure fossil-fired power plant (FPP). the electric power of the fast converter is 1,508 MW(electric). The number of coolant loops is only two because of the high coolant enthalpy. Containment volume is much reduced. The thermal efficiency is improved 24% over a BWR. The coolant void reactivity is negative by placing thin zirconium-hydride layers between seeds and blankets. The power costs would be much reduced compared with those of a light water reactor (LWR) and a liquid-metal fast breeder reactor. The concept is based on the huge amount of experience with the water coolant technology of LWRs and FPPs. The oxidation of stainless steel cladding is avoided by adopting a much lower coolant temperature than that of the FPP.

  13. Corrosion control when using passively treated abandoned mine drainage as alternative makeup water for cooling systems.

    PubMed

    Hsieh, Ming-Kai; Chien, Shih-Hsiang; Li, Heng; Monnell, Jason D; Dzombak, David A; Vidic, Radisav D

    2011-09-01

    Passively treated abandoned mine drainage (AMD) is a promising alternative to fresh water as power plant cooling water system makeup water in mining regions where such water is abundant. Passive treatment and reuse of AMD can avoid the contamination of surface water caused by discharge of abandoned mine water, which typically is acidic and contains high concentrations of metals, especially iron. The purpose of this study was to evaluate the feasibility of reusing passively treated AMD in cooling systems with respect to corrosion control through laboratory experiments and pilot-scale field testing. The results showed that, with the addition of the inhibitor mixture orthophosphate and tolyltriazole, mild steel and copper corrosion rates were reduced to acceptable levels (< 0.127 mm/y and < 0.0076 mm/y, respectively). Aluminum had pitting corrosion problems in every condition tested, while cupronickel showed that, even in the absence of any inhibitor and in the presence of the biocide monochloramine, its corrosion rate was still very low (0.018 mm/y).

  14. Heat transfer coefficient distribution over the inconel plate cooled from high temperature by the array of water jets

    NASA Astrophysics Data System (ADS)

    Malinowski, Z.; Telejko, T.; Cebo-Rudnicka, A.; Szajding, A.; Rywotycki, M.; Hadała, B.

    2016-09-01

    The industrial rolling mills are equipped with systems for controlled water cooling of hot steel products. A cooling rate affects the final mechanical properties of steel which are strongly dependent on microstructure evolution processes. In case of water jets cooling the heat transfer boundary condition can be defined by the heat transfer coefficient. In the present study one and three dimensional heat conduction models have been employed in the inverse solution to heat transfer coefficient. The inconel plate has been heated to about 900oC and then cooled by one, two and six water jets. The plate temperature has been measured by 30 thermocouples. The heat transfer coefficient distributions at plate surface have been determined in time of cooling.

  15. Production of long-term global water vapor and liquid water data set using ultra-fast methods to assimilate multi-satellite and radiosonde observations

    NASA Technical Reports Server (NTRS)

    Vonderhaar, T. H.; Reinke, Donald L.; Randel, David L.; Stephens, Graeme L.; Combs, Cynthia L.; Greenwald, Thomas J.; Ringerud, Mark A.; Wittmeyer, Ian L.

    1993-01-01

    During the next decade, many programs and experiments under the Global Energy and Water Cycle Experiment (GEWEX) will utilize present day and future data sets to improve our understanding of the role of moisture in climate, and its interaction with other variables such as clouds and radiation. An important element of GEWEX will be the GEWEX Water Vapor Project (GVaP), which will eventually initiate a routine, real-time assimilation of the highest quality, global water vapor data sets including information gained from future data collection systems, both ground and space based. The comprehensive global water vapor data set being produced by METSAT Inc. uses a combination of ground-based radiosonde data, and infrared and microwave satellite retrievals. This data is needed to provide the desired foundation from which future GEWEX-related research, such as GVaP, can build. The first year of this project was designed to use a combination of the best available atmospheric moisture data including: radiosonde (balloon/acft/rocket), HIRS/MSU (TOVS) retrievals, and SSM/I retrievals, to produce a one-year, global, high resolution data set of integrated column water vapor (precipitable water) with a horizontal resolution of 1 degree, and a temporal resolution of one day. The time period of this pilot product was to be det3ermined by the availability of all the input data sets. January 1988 through December 1988 were selected. In addition, a sample of vertically integrated liquid water content (LWC) was to be produced with the same temporal and spatial parameters. This sample was to be produced over ocean areas only. Three main steps are followed to produce a merged water vapor and liquid water product. Input data from Radiosondes, TOVS, and SSMI/I is quality checked in steps one and two. Processing is done in step two to generate individual total column water vapor and liquid water data sets. The third step, and final processing task, involves merging the individual output

  16. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

  17. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corp. , Columbus, Ohio. Final report

    SciTech Connect

    1980-11-01

    The Solar Energy System located at the Columbia Gas Corporation, Columbus, Ohio, has 2978 ft/sup 2/ of Honeywell single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/h Bryan water-tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton Arkla hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts are included from the site files, specification references, drawings, installation, operation and maintenance instructions.

  18. Presence of pathogenic amoebae in power plant cooling waters. Final report, October 15, 1977-September 30, 1979. [Naegleria fowleri

    SciTech Connect

    Tyndall, R.L.; Willaert, E.; Stevens, A.R.

    1981-03-01

    Cooling-water-associated algae and sediments from five northern and five southern or western electric power plants were tested for the presence of pathogenic amoebae. In addition, water algae and sediments from five northern and five southern/western sites not associated with power plants were tested. There was a significant correlation at northern power plants between the presence of thermophilic, pathogenic amoebae in cooling waters and thermal additions. Presence of the pathogenic did not correlate with salinity, pH, conductivity, or a variety of various chemical components of the cooling waters. Selected pathogenic isolates were tested serologically and were classified as Naegleria fowleri. Although thermal additions were shown to be contributing factor in predisposing cooling waters to the growth of pathogenic amoebae, the data suggest the involvement of other currently undefined parameters associated with the presence of the pathogenic amoebae. 35 refs., 21 tabs.

  19. Temperature distribution of a hot water storage tank in a simulated solar heating and cooling system

    NASA Technical Reports Server (NTRS)

    Namkoong, D.

    1976-01-01

    A 2,300-liter hot water storage tank was studied under conditions simulating a solar heating and cooling system. The initial condition of the tank, ranging from 37 C at the bottom to 94 C at the top, represented a condition midway through the start-up period of the system. During the five-day test period, the water in the tank gradually rose in temperature but in a manner that diminished its temperature stratification. Stratification was found not to be an important factor in the operation of the particular solar system studied.

  20. Leaf conductance in relation to rate of CO/sub 2/ assimilation. III. Influences of water stress and photoinhibition. [Zea mays

    SciTech Connect

    Wong, S.C.; Cowan, I.R.; Farquhar, G.D.

    1985-01-01

    Rates of CO/sub 2/ assimilation and leaf conductances to CO/sub 2/ transfer were measured in plants of Zea mays during a period of 14 days in which the plants were not rewatered, and leaf water potential decreased from -0.5 to -0.8 bar. At any given ambient partial pressure of CO/sub 2/, water stress reduced rate of assimilation and leaf conductance similarly, so that intercellular partial pressure of CO/sub 2/ remained almost constant. At normal ambient partial pressure of CO/sub 2/, the intercellular partial pressure of CO/sub 2/ was estimated to be 95 microbars. This is the same as had been estimated in plants of Zea mays grown with various levels of nitrogen supply, phosphate supply and irradiance, and in plants of Zea mays examined at different irradiances. After leaves of Phaseolus vulgaris L. and Eucalyptus pauciflora Sieb. ex Spreng had been exposed to high irradiance in an atmosphere of CO/sub 2/-free N/sub 2/ with 10 millibars O/sub 2/, rates of assimilation and leaf conductances measured in standard conditions had decreased in similar proportions, so that intercellular partial pressure of CO/sub 2/ remained almost unchanged. As the conductance of each epidermis that had not been directly irradiated had declined as much as that in the opposite, irradiated surface it was hypothesized that conductance may have been influenced by photoinhibition within the mesophyll tissue. 16 references, 4 figures, 3 tables.

  1. Investigation of corrosion caused by constituents of refinery wastewater effluent used as circulating cooling water.

    PubMed

    Zhang, Zhongzhi; Song, Shaofu; Huang, Jie; Ji, Lin; Wu, Fangyun

    2003-01-01

    The corrosion rate of steel plate using single-factor, multifactor, and complex water systems was investigated via refinery wastewater effluents used as circulating cooling water. The results show that the primary corrosion factors of steel depend on the characteristics of the ions, the formation of the oxidized coating, the diffusion of dissolved oxygen, and other complex factors, although ions such as chloride, calcium, and carbonate play an important role. The corrosion rate of carbon steel exhibits two trends: The corrosion rate is high at low conductivity, increases to a maximum, and then decreases and becomes stable with increasing conductivity, as is the case with chloride, sulfate, nitrate and calcium ions. On the other hand, the corrosion rate is highest at low conductivity and then decreases and becomes stable with increasing conductivity, as is the case with carbonate, silicate, and sodium nitrate ions. Research results indicate that the anticorrosive ability is minimal at low conductivity; but is excellent at high conductivity. Pretreatment of low-conductivity water using air flotation and clarification to decrease the concentrations of chloride, calcium, and carbonate ions to a suitable level to satisfy the anticorrosion requirements is required. However, it is not necessary to significantly reduce the salt concentration or conductivity of the water by osmosis or ion exchange to obtain an anticorrosion effect when reusing wastewater effluents as circulating cooling water.

  2. Influence of water quench cooling on degassing and aroma stability of roasted coffee.

    PubMed

    Baggenstoss, Juerg; Poisson, Luigi; Luethi, Regina; Perren, Rainer; Escher, Felix

    2007-08-08

    Coffee roasting experiments with air cooling versus water quench cooling were carried out on laboratory scale with a fluidized-bed hot air roasting system (200 g batch size) and on production scale with a rotating bowl roaster (320 kg batch size). Two series of coffees with different water contents resulted, which were stored at 25 degrees C under normal atmospheric conditions. Carbon dioxide desorption was followed and stability of selected aroma compounds was tested with headspace solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) and stable isotope labeled compounds as internal standards. Degassing is faster in water-quenched coffees with higher moisture content, but pore size distribution in the different coffee samples did not correlate with degassing behavior. Bean firmness, which increases with increasing moisture content, might have an influence on degassing. Air- and water-quenched coffees exhibit similar stability of most aroma compounds despite different degassing behavior. However, evolution of dimethyl trisulfide was different in coffees with increased water content. This suggests higher thiol oxidation rates, a factor that is cited to be related to a faster loss of freshness attributes.

  3. USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES

    SciTech Connect

    Michael N. DiFilippo

    2004-08-01

    The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. Deliverable 1 presents a general assessment of produced water generation in the San Juan Basin in Four Corners Area of New Mexico. Oil and gas production, produced water handling and disposal, and produced water quantities and chemistry are discussed. Legislative efforts to enable the use of this water at SJGS are also described.

  4. Plant control of a fast breeder reactor cooled by supercritical light water

    SciTech Connect

    Nakatsuka, T.; Oka, Y.; Koshizuka, S.

    1997-12-01

    Supercritical water does not exhibit a change of phase. The plant system of the supercritical water cooled reactor is the once-through, direct-cycle where the steam-water separator and coolant recirculation systems are eliminated. It is different from those of BWR and PWR. The reactor is sensitive to the perturbations of the feedwater flow rate, since the whole core coolant driven by the feedwater pumps flows to the turbines. The axial coolant density change is larger than that of a BWR. Pressure control by the feedwater like the supercritical fossil-fired power plant (FPP) is not appropriate because the change of feedwater flow rate largely affects the core power through the coolant density feedback. It is necessary to analyze the controllability of the plant against coolant flow and pressure perturbations for assessing the technical feasibility of the reactor. The plant behaviors of a fast breeder reactor cooled by supercritical water (SCFBR) are analyzed for three principal perturbations: the change of the control rod position, the feedwater flow rate and the turbine control valve opening. Based on the step responses to the perturbations, the plant control system is designed: the pressure is controlled by the turbine control valves, the main steam temperature is controlled by the feedwater flow rate and the core power is controlled by the control rods. Parameters of the control system are selected by the test calculations to satisfy both fast convergence and stability criteria. The plant behaviors with the designed plant control system are stable against the perturbations. The reactor cooled by supercritical light water is controllable with the plant control system designed here. 7 refs., 11 figs., 6 tabs.

  5. Technical analysis of a river basin-based model of advanced power plant cooling technologies for mitigating water management challenges

    NASA Astrophysics Data System (ADS)

    Stillwell, Ashlynn S.; Clayton, Mary E.; Webber, Michael E.

    2011-07-01

    Thermoelectric power plants require large volumes of water for cooling, which can introduce drought vulnerability and compete with other water needs. Alternative cooling technologies, such as cooling towers and hybrid wet-dry or dry cooling, present opportunities to reduce water diversions. This case study uses a custom, geographically resolved river basin-based model for eleven river basins in the state of Texas (the Brazos and San Jacinto-Brazos, Colorado and Colorado-Brazos, Cypress, Neches, Nueces, Red, Sabine, San Jacinto, and Trinity River basins), focusing on the Brazos River basin, to analyze water availability during drought. We utilized two existing water availability models for our analysis: (1) the full execution of water rights—a scenario where each water rights holder diverts the full permitted volume with zero return flow, and (2) current conditions—a scenario reflecting actual diversions with associated return flows. Our model results show that switching the cooling technologies at power plants in the eleven analyzed river basins to less water-intensive alternative designs can potentially reduce annual water diversions by 247-703 million m3—enough water for 1.3-3.6 million people annually. We consider these results in a geographic context using geographic information system tools and then analyze volume reliability, which is a policymaker's metric that indicates the percentage of total demand actually supplied over a given period. This geographic and volume reliability analysis serves as a measure of drought susceptibility in response to changes in thermoelectric cooling technologies. While these water diversion savings do not alleviate all reliability concerns, the additional streamflow from the use of dry cooling alleviates drought concerns for some municipal water rights holders and might also be sufficient to uphold instream flow requirements for important bays and estuaries on the Texas Gulf coast.

  6. Investigation of flow characteristics effects on heat transfer in water-cooled cylinder heads

    NASA Astrophysics Data System (ADS)

    Hassan, M. A. M.; Abd El-Hameed, H. M.; Mahmoud, Osama E.

    2017-04-01

    An experimental and theoretical study has been performed to investigate the effect of flow characteristics on heat-transfer in water impingement-cooled cylinder heads. Numerous investigations have been made using a three-dimensional model, which is designed and solved by FLUENT software using both realizable k-ɛ turbulent and heat transfer models. The simulation investigates a fully developed turbulent-water flow in asymmetric heated circular passage cooled by parallel flow or impingement of circular submerged confined liquid jet. The following parameters were investigated for both parallel flow and jet impingement flow: flow velocities (1, 2 and 3 m/s), bulk fluid temperatures (50, 70 and 90 °C), main duct diameters (6, 8, 10 and 12 mm). While the following parameters were investigated for jet impingement flow, jet diameter ratio (0.6, 0.8 and 1) and jet inclination angles as measured from horizontal (45°, 60° and 90°). Experimental results were used to verify the theoretical model. Results indicate that, the normal jet (90°) gives the maximum cooling effect in comparison to other angles while the maximum heat transfer coefficient is found at jet interface position.

  7. Investigation of flow characteristics effects on heat transfer in water-cooled cylinder heads

    NASA Astrophysics Data System (ADS)

    Hassan, M. A. M.; Abd El-Hameed, H. M.; Mahmoud, Osama E.

    2016-08-01

    An experimental and theoretical study has been performed to investigate the effect of flow characteristics on heat-transfer in water impingement-cooled cylinder heads. Numerous investigations have been made using a three-dimensional model, which is designed and solved by FLUENT software using both realizable k-ɛ turbulent and heat transfer models. The simulation investigates a fully developed turbulent-water flow in asymmetric heated circular passage cooled by parallel flow or impingement of circular submerged confined liquid jet. The following parameters were investigated for both parallel flow and jet impingement flow: flow velocities (1, 2 and 3 m/s), bulk fluid temperatures (50, 70 and 90 °C), main duct diameters (6, 8, 10 and 12 mm). While the following parameters were investigated for jet impingement flow, jet diameter ratio (0.6, 0.8 and 1) and jet inclination angles as measured from horizontal (45°, 60° and 90°). Experimental results were used to verify the theoretical model. Results indicate that, the normal jet (90°) gives the maximum cooling effect in comparison to other angles while the maximum heat transfer coefficient is found at jet interface position.

  8. Modeling and characterization of shape memory alloy springs with water cooling strategy in a neurosurgical robot.

    PubMed

    Cheng, Shing Shin; Kim, Yeongjin; Desai, Jaydev P

    2017-09-01

    Since shape memory alloy (SMA) has high power density and is magnetic resonance imaging (MRI) compatible, it has been chosen as the actuator for the meso-scale minimally invasive neurosurgical intracranial robot (MINIR-II) that is envisioned to be operated under continuous MRI guidance. We have devised a water cooling strategy to improve its actuation frequency by threading a silicone tube through the spring coils to form a compact cooling module-integrated actuator. To create active bi-directional motion in each robot joint, we configured the SMA springs in an antagonistic way. We modeled the antagonistic SMA spring behavior and provided the detailed steps to simulate its motion for a complete cycle. We investigated heat transfer during the resistive heating and water cooling processes. Characterization experiments were performed to determine the parameters used in both models, which were then verified by comparing the experimental and simulated data. The actuation frequency of the antagonistic SMAs was evaluated for several motion amplitudes and we could achieve a maximum actuation frequency of 0.143 Hz for a sinusoidal trajectory with 2 mm amplitude. Lastly, we developed a robotic system to implement the actuators on the MINIR-II to move its end segment back and forth for approximately ±25°.

  9. Occurrence of American shad eggs in 1G cooling-water canal

    SciTech Connect

    McFarlane, R.W.

    1982-08-01

    American shad eggs are only semi-bouyant and require river turbulence to remain suspended in the water column long enough (three days) for the larvae to hatch. In 1978, shad eggs entrained into the Savannah River Plant 16 cooling-water canal sank to the bottom of the canal before reaching the pumphouse. Eggs removed from the water column in this manner due to decreasing water velocity and turbulence would most likely be lost to predation and burial in the bottom sediments. Efforts to determine egg densities in the river and intake canals were unsuccessful due to the persistent bloom of a slime fungus (Leptomitus sp.) which clogged the plankton sampling apparatus. Thus quantitative estimates of shad egg losses were not obtainable. Further qualitative data would not have been cost-effective so the observations were terminated.

  10. Devitrification of Impact Glasses at the Bosumtwi Impact Structure, Ghana: Implications for Suevite Cooling History and Presence of Water

    NASA Astrophysics Data System (ADS)

    Välja, R.; Kirsimäe, K.; Koeberl, C.; Boamah, D. K.

    2015-09-01

    We report petrography and geochemistry of devitrification products in impact glasses in Bosumtwi suevites and we aim for refining the cooling history of suevites and estimate the presence-influence of water on the impact glass devitrification.

  11. Sensitivity Analysis of Reprocessing Cooling Times on Light Water Reactor and Sodium Fast Reactor Fuel Cycles

    SciTech Connect

    R. M. Ferrer; S. Bays; M. Pope

    2008-04-01

    The purpose of this study is to quantify the effects of variations of the Light Water Reactor (LWR) Spent Nuclear Fuel (SNF) and fast reactor reprocessing cooling time on a Sodium Fast Reactor (SFR) assuming a single-tier fuel cycle scenario. The results from this study show the effects of different cooling times on the SFR’s transuranic (TRU) conversion ratio (CR) and transuranic fuel enrichment. Also, the decay heat, gamma heat and neutron emission of the SFR’s fresh fuel charge were evaluated. A 1000 MWth commercial-scale SFR design was selected as the baseline in this study. Both metal and oxide CR=0.50 SFR designs are investigated.

  12. Solar heating, cooling, and hot water systems installed at Richland, Washington

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The project described is part of the U. S. Department of Energy's solar demonstration program, and became operational in April 1978. The solar system uses 6,000 square feet of flat-plate liquid collectors in a closed loop to deliver solar energy through a liquid-liquid heat exchanger to the building heat-pump duct work or 9,000-gallon thermal energy storage tank. A 25-ton Arkla solar-driven absorption chiller provides the cooling, in conjunction with a 2,000 gallon chilled water storage tank and reflective ponds on three sides of the building surplus heat. A near-by building is essentially identical except for having conventional heat-pump heating and cooling, and can serve as an experimental control. An on-going public relations program was provided from the beginning of the program, and resulted in numerous visitors and tour groups.

  13. Water-cooled grid support for high-power irradiation with thin target windows.

    PubMed

    Barnhart, T E; Converse, A K; Dabbs, K A; Nickles, R J; Buckley, K; Jivan, S; Ruth, T J; Roberts, A D

    2003-01-01

    A new thin window support system for the accelerator production of positron emitters (e.g. 17F, 18F 11C, 15O) has been developed. The integrated support grid and cooling design has been optimized for 6-13 MeV protons or deuterons. The water-cooled support grid regularly operated at > 100 microA of 6 MeV deuterons and protons. The grid performed without failure at > or = 50 microA of 13 MeV protons on a 3.1 MPa gas target using 25.4 microm aluminum target foil. Transmission for the smallest hole grid of 72% based on uniform parallel beam agreed with the measured yield of 71 +/- 1% compared to the theoretical maximum yield. Copyright 2002 Elsevier Science Ltd.

  14. Combined effects of pre-cooling and water ingestion on thermoregulation and physical capacity during exercise in a hot environment.

    PubMed

    Hasegawa, Hiroshi; Takatori, Tadashi; Komura, Takashi; Yamasaki, Masahiro

    2006-01-01

    The aim of the present study was to determine the combined effects of pre-cooling and water ingestion on thermoregulatory responses and exercise capacity at 32 degrees C and 80% relative humidity. Nine untrained males exercised for 60 min on a cycle ergometer at 60% maximal oxygen uptake (VO2max) (first exercise bout) under four separate conditions: No Water intake, Pre-cooling, Water ingestion, and a combination of pre-cooling and water ingestion (Combined). To evaluate the efficacy of these conditions on exercise capacity, the participants exercised to exhaustion at 80% VO2max (second exercise bout) following the first exercise bout. Rectal and mean skin temperatures before the first exercise bout in the Pre-cooling and Combined conditions were significantly lower than in the No Water and Water conditions. At the end of the first exercise bout, rectal temperature was lower in the Combined condition (38.5 +/- 0.1 degrees C) than in the other conditions (No Water: 39.1 +/- 0.1 degrees C; Pre-cooling: 38.7 +/- 0.1 degrees C; Water: 38.8 +/- 0.1 degrees C) (P < 0.05). Heat storage was higher following pre-cooling than when there was no pre-cooling (P < 0.05). The final rectal temperature in the second exercise bout was similar between the four conditions (39.1 +/- 0.1 degrees C). However, exercise time to exhaustion was longer (P < 0.05) in the Combined condition than in the other conditions. Total sweat loss was less following pre-cooling than when there was no pre-cooling (P < 0.001). Evaporative sweat loss in the Water and Combined conditions was greater (P < 0.01) than in the No Water and Pre-cooling conditions. Our results suggest that the combination of pre-cooling and water ingestion increases exercise endurance in a hot environment through enhanced heat storage and decreased thermoregulatory and cardiovascular strain.

  15. Pliocene cooling enhanced by flow of low-salinity Bering Sea water to the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Horikawa, Keiji; Martin, Ellen E.; Basak, Chandranath; Onodera, Jonaotaro; Seki, Osamu; Sakamoto, Tatsuhiko; Ikehara, Minoru; Sakai, Saburo; Kawamura, Kimitaka

    2015-06-01

    Warming of high northern latitudes in the Pliocene (5.33-2.58 Myr ago) has been linked to the closure of the Central American Seaway and intensification of North Atlantic Deep Water. Subsequent cooling in the late Pliocene may be related to the effects of freshwater input from the Arctic Ocean via the Bering Strait, disrupting North Atlantic Deep Water formation and enhancing sea ice formation. However, the timing of Arctic freshening has not been defined. Here we present neodymium and lead isotope records of detrital sediment from the Bering Sea for the past 4.3 million years. Isotopic data suggest the presence of Alaskan glaciers as far back as 4.2 Myr ago, while diatom and C37:4 alkenone records show a long-term trend towards colder and fresher water in the Bering Sea beginning with the M2 glaciation (3.3 Myr ago). We argue that the introduction of low-salinity Bering Sea water to the Arctic Ocean by 3.3 Myr ago preconditioned the climate system for global cooling.

  16. Pliocene cooling enhanced by flow of low-salinity Bering Sea water to the Arctic Ocean

    PubMed Central

    Horikawa, Keiji; Martin, Ellen E.; Basak, Chandranath; Onodera, Jonaotaro; Seki, Osamu; Sakamoto, Tatsuhiko; Ikehara, Minoru; Sakai, Saburo; Kawamura, Kimitaka

    2015-01-01

    Warming of high northern latitudes in the Pliocene (5.33–2.58 Myr ago) has been linked to the closure of the Central American Seaway and intensification of North Atlantic Deep Water. Subsequent cooling in the late Pliocene may be related to the effects of freshwater input from the Arctic Ocean via the Bering Strait, disrupting North Atlantic Deep Water formation and enhancing sea ice formation. However, the timing of Arctic freshening has not been defined. Here we present neodymium and lead isotope records of detrital sediment from the Bering Sea for the past 4.3 million years. Isotopic data suggest the presence of Alaskan glaciers as far back as 4.2 Myr ago, while diatom and C37:4 alkenone records show a long-term trend towards colder and fresher water in the Bering Sea beginning with the M2 glaciation (3.3 Myr ago). We argue that the introduction of low-salinity Bering Sea water to the Arctic Ocean by 3.3 Myr ago preconditioned the climate system for global cooling. PMID:26119338

  17. Pliocene cooling enhanced by flow of low-salinity Bering Sea water to the Arctic Ocean.

    PubMed

    Horikawa, Keiji; Martin, Ellen E; Basak, Chandranath; Onodera, Jonaotaro; Seki, Osamu; Sakamoto, Tatsuhiko; Ikehara, Minoru; Sakai, Saburo; Kawamura, Kimitaka

    2015-06-29

    Warming of high northern latitudes in the Pliocene (5.33-2.58 Myr ago) has been linked to the closure of the Central American Seaway and intensification of North Atlantic Deep Water. Subsequent cooling in the late Pliocene may be related to the effects of freshwater input from the Arctic Ocean via the Bering Strait, disrupting North Atlantic Deep Water formation and enhancing sea ice formation. However, the timing of Arctic freshening has not been defined. Here we present neodymium and lead isotope records of detrital sediment from the Bering Sea for the past 4.3 million years. Isotopic data suggest the presence of Alaskan glaciers as far back as 4.2 Myr ago, while diatom and C37:4 alkenone records show a long-term trend towards colder and fresher water in the Bering Sea beginning with the M2 glaciation (3.3 Myr ago). We argue that the introduction of low-salinity Bering Sea water to the Arctic Ocean by 3.3 Myr ago preconditioned the climate system for global cooling.

  18. Natural Convection Heat Transfer Characteristics of Liquid Metal Cooled by Subcooled Water

    SciTech Connect

    Lee, Il S.; Yu, Yong H.; Son, Hyoung M.; Suh, Kune Y.

    2006-07-01

    An experimental study is performed to investigate the natural convection heat transfer characteristics with subcooled coolant to create engineering database for basic applications in a lead alloy cooled reactor. Tests are performed in the ALTOS (Applied Liquid-metal Thermal Operation Study) apparatus as part of MITHOS (Metal Integrated Thermo Hydrodynamic Operation System). The relationship between the Nusselt number (Nu) and the Rayleigh number (Ra) in the liquid metal is determined and compared with the correlations in the literature and experimental results. Given the similar Ra condition, the present test results for Nu of the liquid metal pool with subcooled coolant are found to be similar to those predicted by the existing correlations or measured from previous experiments. The current experimental results are utilized to develop new engineering solutions. The new experimental correlations for predicting the natural convection heat transfer are applicable to low Prandtl number (Pr) materials that are heated from below and cooled by the external coolant above. Results from this study are slated to be used to design BORIS (Battery Optimized Reactor Integral System), a small lead cooled modular fast reactor for deployment in remote sites. Tests are performed with air, water and Wood's metal (Pb-Bi-Sn-Cd) filling a rectangular pool while the lower surface is heated and the upper surface cooled by forced convection of water. The inner dimensions of the test section are 20 cm in length, 11.3 cm in height, and 15 cm in width. Wood's metal has a melting temperature of 78 deg. C. Constant temperature and heat flux condition is adopted for the bottom heating. The test parameters include the heated bottom surface temperature of the liquid metal pool, the input power to the bottom surface of the section, and the coolant temperature. (authors)

  19. Direct injection GC method for measuring light hydrocarbon emissions from cooling-tower water.

    PubMed

    Lee, Max M; Logan, Tim D; Sun, Kefu; Hurley, N Spencer; Swatloski, Robert A; Gluck, Steve J

    2003-12-15

    A Direct Injection GC method for quantifying low levels of light hydrocarbons (C6 and below) in cooling water has been developed. It is intended to overcome the limitations of the currently available technology. The principle of this method is to use a stripper column in a GC to strip waterfrom the hydrocarbons prior to entering the separation column. No sample preparation is required since the water sample is introduced directly into the GC. Method validation indicates that the Direct Injection GC method offers approximately 15 min analysis time with excellent precision and recovery. The calibration studies with ethylene and propylene show that both liquid and gas standards are suitable for routine calibration and calibration verification. The sampling method using zero headspace traditional VOA (Volatile Organic Analysis) vials and a sample chiller has also been validated. It is apparent that the sampling method is sufficient to minimize the potential for losses of light hydrocarbons, and samples can be held at 4 degrees C for up to 7 days with more than 93% recovery. The Direct Injection GC method also offers <1 ppb (w/v) level method detection limits for ethylene, propylene, and benzene. It is superior to the existing El Paso stripper method. In addition to lower detection limits for ethylene and propylene, the Direct Injection GC method quantifies individual light hydrocarbons in cooling water, provides better recoveries, and requires less maintenance and setup costs. Since the instrumentation and supplies are readily available, this technique could easily be established as a standard or alternative method for routine emission monitoring and leak detection of light hydrocarbons in cooling-tower water.

  20. Numerical Investigation of the Flow Dynamics and Evaporative Cooling of Water Droplets Impinging onto Heated Surfaces: An Effective Approach To Identify Spray Cooling Mechanisms.

    PubMed

    Chen, Jian-Nan; Zhang, Zhen; Xu, Rui-Na; Ouyang, Xiao-Long; Jiang, Pei-Xue

    2016-09-13

    Numerical investigations of the dynamics and evaporative cooling of water droplets impinging onto heated surfaces can be used to identify spray cooling mechanisms. Droplet impingement dynamics and evaporation are simulated using the presented numerical model. Volume-of-fluid method is used in the model to track the free surface. The contact line dynamics was predicted from a dynamic contact angle model with the evaporation rate predicted by a kinetic theory model. A species transport equation was solved in the gas phase to describe the vapor convection and diffusion. The numerical model was validated by experimental data. The physical effects including the contact angle hysteresis and the thermocapillary effect are analyzed to offer guidance for future numerical models of droplet impingement cooling. The effects of various parameters including surface wettability, surface temperature, droplet velocity, droplet size, and droplet temperature were numerically studied from the standpoint of spray cooling. The numerical simulations offer profound analysis and deep insight into the spray cooling heat transfer mechanisms.

  1. Heat Transfer Modeling of an Annular On-Line Spray Water Cooling Process for Electric-Resistance-Welded Steel Pipe.

    PubMed

    Chen, Zejun; Han, Huiquan; Ren, Wei; Huang, Guangjie

    2015-01-01

    On-line spray water cooling (OSWC) of electric-resistance-welded (ERW) steel pipes can replace the conventional off-line heat treatment process and become an important and critical procedure. The OSWC process improves production efficiency, decreases costs, and enhances the mechanical properties of ERW steel pipe, especially the impact properties of the weld joint. In this paper, an annular OSWC process is investigated based on an experimental simulation platform that can obtain precise real-time measurements of the temperature of the pipe, the water pressure and flux, etc. The effects of the modes of annular spray water cooling and related cooling parameters on the mechanical properties of the pipe are investigated. The temperature evolutions of the inner and outer walls of the pipe are measured during the spray water cooling process, and the uniformity of mechanical properties along the circumferential and longitudinal directions is investigated. A heat transfer coefficient model of spray water cooling is developed based on measured temperature data in conjunction with simulation using the finite element method. Industrial tests prove the validity of the heat transfer model of a steel pipe undergoing spray water cooling. The research results can provide a basis for the industrial application of the OSWC process in the production of ERW steel pipes.

  2. Heat Transfer Modeling of an Annular On-Line Spray Water Cooling Process for Electric-Resistance-Welded Steel Pipe

    PubMed Central

    Chen, Zejun; Han, Huiquan; Ren, Wei; Huang, Guangjie

    2015-01-01

    On-line spray water cooling (OSWC) of electric-resistance-welded (ERW) steel pipes can replace the conventional off-line heat treatment process and become an important and critical procedure. The OSWC process improves production efficiency, decreases costs, and enhances the mechanical properties of ERW steel pipe, especially the impact properties of the weld joint. In this paper, an annular OSWC process is investigated based on an experimental simulation platform that can obtain precise real-time measurements of the temperature of the pipe, the water pressure and flux, etc. The effects of the modes of annular spray water cooling and related cooling parameters on the mechanical properties of the pipe are investigated. The temperature evolutions of the inner and outer walls of the pipe are measured during the spray water cooling process, and the uniformity of mechanical properties along the circumferential and longitudinal directions is investigated. A heat transfer coefficient model of spray water cooling is developed based on measured temperature data in conjunction with simulation using the finite element method. Industrial tests prove the validity of the heat transfer model of a steel pipe undergoing spray water cooling. The research results can provide a basis for the industrial application of the OSWC process in the production of ERW steel pipes. PMID:26201073

  3. Density of hydrophobically confined deeply cooled water investigated by small angle X-ray scattering

    NASA Astrophysics Data System (ADS)

    Liu, Kao-Hsiang; Zhang, Yang; Jeng, U.-Ser; Mou, Chung-Yuan

    2015-09-01

    Water's behavior near hydrophobic surfaces has attracted great attention due to chemical and geological applications. Here, we report small angle X-ray scattering (SAXS) studies of water confined in the hydrophobic nanoporous carbon material, CMK-1-14, from ambient to deeply cooled temperatures. By monitoring the scattering intensity of the first Bragg peak, which is directly related to the scattering length density contrast between the carbon matrix and the confined water, the average density of the hydrophobically confined water was determined from 300 K to 150 K at ambient pressure. Furthermore, differential scanning calorimetry and X-ray diffraction measurements showed that the majority of such hydrophobically confined water did not crystallize in the investigated temperature range. By exploiting the fast speed of SAXS measurements and the continuous temperature ramping, the average density profile and the deduced thermal expansion coefficient (αp) were obtained. We found that the well-known density maximum of water at 277 K downshifted to 260 K, and the density minimum which has been observed in hydrophilic confinement disappeared. In addition, the previously measured large density decreasing of 18% at low temperature was recalibrated to a more reasonable 10% instead. Consequently, the recalculated αp peak was found to be quite similar to that of the water confined in hydrophilic MCM-41-S-15 suggesting an intrinsic property of water, which does not sensitively depend on the confinement surface.

  4. What causes cooling water temperature gradients in a forested stream reach?

    NASA Astrophysics Data System (ADS)

    Garner, G.; Malcolm, I. A.; Sadler, J. P.; Hannah, D. M.

    2014-12-01

    Previous studies have suggested that shading by riparian vegetation may reduce maximum water temperatures and provide refugia for temperature-sensitive aquatic organisms. Longitudinal cooling gradients have been observed during the daytime for stream reaches shaded by coniferous trees downstream of clear cuts or deciduous woodland downstream of open moorland. However, little is known about the energy exchange processes that drive such gradients, especially in semi-natural woodland contexts without confounding cool groundwater inflows. To address this gap, this study quantified and modelled variability in stream temperature and heat fluxes along an upland reach of the Girnock Burn (a tributary of the Aberdeenshire Dee, Scotland) where riparian land use transitions from open moorland to semi-natural, predominantly deciduous woodland. Observations were made along a 1050 m reach using a spatially distributed network of 10 water temperature data loggers, 3 automatic weather stations and 211 hemispherical photographs that were used to estimate incoming solar radiation. These data parameterised a high-resolution energy flux model incorporating flow routing, which predicted spatio-temporal variability in stream temperature. Variability in stream temperature was controlled largely by energy fluxes at the water-column-atmosphere interface. Net energy gains occurred along the reach, predominantly during daylight hours, and heat exchange across the bed-water-column interface accounted for <1% of the net energy budget. For periods when daytime net radiation gains were high (under clear skies), differences between water temperature observations increased in the streamwise direction; a maximum instantaneous difference of 2.5 °C was observed between the upstream reach boundary and 1050 m downstream. Furthermore, daily maximum water temperature at 1050 m downstream was ≤1 °C cooler than at the upstream reach boundary and lagged by >1 h. Temperature gradients were not generated

  5. Bioluminescence-Based Method for Measuring Assimilable Organic Carbon in Pretreatment Water for Reverse Osmosis Membrane Desalination ▿

    PubMed Central

    Weinrich, Lauren A.; Schneider, Orren D.; LeChevallier, Mark W.

    2011-01-01

    A bioluminescence-based assimilable organic carbon (AOC) test was developed for determining the biological growth potential of seawater within the reverse osmosis desalination pretreatment process. The test uses Vibrio harveyi, a marine organism that exhibits constitutive luminescence and is nutritionally robust. AOC was measured in both a pilot plant and a full-scale desalination plant pretreatment. PMID:21148685

  6. Bioluminescence-based method for measuring assimilable organic carbon in pretreatment water for reverse osmosis membrane desalination.

    PubMed

    Weinrich, Lauren A; Schneider, Orren D; LeChevallier, Mark W

    2011-02-01

    A bioluminescence-based assimilable organic carbon (AOC) test was developed for determining the biological growth potential of seawater within the reverse osmosis desalination pretreatment process. The test uses Vibrio harveyi, a marine organism that exhibits constitutive luminescence and is nutritionally robust. AOC was measured in both a pilot plant and a full-scale desalination plant pretreatment.

  7. Hydraulic design of a re-circulating water cooling system of a combined cycle power plant in Thailand

    SciTech Connect

    Sarkar, C.K.; Pandit, D.R.; Kwon, S.G.

    1998-12-31

    The paper describes the hydraulic design and hydraulic transient analysis of the re-circulating water cooling system of the combined cyclo Sipco power cogeneration plant in Thailand. The power plant of 450 MW total capacity is proposed to be built in two stages. Stage one will produce 300 MW of power and will consist of two gas turbine generators (GTG) and one steam turbine generator (STG). Stage two will produce 150 MW of power and will consist of one GTG and one STG. The cooling system will consist of one GTG and one STG. The cooling system will consist of cooling towers, a combined collecting basin and pump intake sump, pumps and motors, and separate conveyance systems and condensers for the generator units in the two stages. In a re-circulating water cooling system, cold water is pumped from the pump intake sump to the condensers through the conveyance system and hot water from the condensers is carried through the returning pipeline system to the cooling towers, whence the water after cooling is drained into the sump at the base of the towers. Total cooling water requirement for the system in stage one is estimated to be 112,000 gallons per minute (GPM), and that in stage two, 56,000 GPM. The sump is designed using the computer program HEC-2, developed by the US Army Corps of Engineers (COE) and the pump intake basin, following the recommendations of the Hydraulic Institute. The pumps were sized by computing the head loss in the system, and, the steady state and transient performances (during pump start-up and shut-down procedures and due to possible power or mechanical failure of one or all pumps) of the system were analyzed by mathematically modeling the system using the computer program WHAMO (Water Hammer nd Mass Oscillations), also developed by the COE.

  8. Mpemba effect and phase transitions in the adiabatic cooling of water before freezing

    NASA Astrophysics Data System (ADS)

    Esposito, S.; De Risi, R.; Somma, L.

    2008-02-01

    In this paper, an accurate experimental investigation of the Mpemba effect (that is, of the fact that initially hot water freezes before the colder one) is carried out, showing that, in the adiabatic cooling of water, relevant roles are played by supercooling, and by phase transitions which take place at 6±1 ∘C,3.5±0.5 ∘C and 1.3±0.6 ∘C. The last transition, which occurs with the non-negligible probability of 0.21 with respect to the total number of runs performed, has not been detected earlier. On the basis of our experimental results, we can present a thorough theoretical analysis of supercooling and of such phase transitions, which are interpreted in terms of the different ordering of molecule clusters in water.

  9. Experimental simulation of the water cooling of corium spread over the floor of a BWR containment

    SciTech Connect

    Morage, F.; Lahey, R.T. Jr.; Podowski, M.Z.

    1995-09-01

    This paper is concerned with an experimental investigation of the cooling effect of water collected on the surface of corium released onto the floor of a BWR drywell. In the present experiments, the actual reactor materials were replaced by simulant materials. Specifically, the results are shown for Freon-11 film boiling over liquid Wood`s metal spread above a solid porous surface through which argon gas was injected. An analysis of the obtained experimental data revealed that the actual film boiling heat transfer between a molten pool of corium and the water above the pool should be more efficient than predicted by using standard correlations for boiling over solid surfaces. This effect will be further augmented by the gas released due to the ablation of concrete floor beneath the corium and percolating towards its upper surface and into through the water layer above.

  10. Transient cooling of a hot metal plate with an impinging water jet

    SciTech Connect

    Kumagai, Satoshi; Suzuki, Shinju; Kubo, Ryo; Kawazoe, Masataka

    1995-12-31

    Transient boiling heat-transfer rate of a two-dimensional impinging water jet was measured throughout the surface of a 20 x 150 mm rectangle, during cooling from approximately 400 C to 100 C. Time-dependent surface-temperature distributions and the progress of a solid-liquid contact front were obtained for jet subcooling from 14 K to 50 K. Solid-liquid contact at the stagnation line starts from the moment of jet impingement, where violent boiling occurs and generated vapor splashes the water film; this results in deprivation of water supply to the outer region of the surface. The temperature of the outer surface remains high up to the time when the solid-liquid contact front reaches it and a large temperature gradient appears near the front. The surface temperature for the initiation of solid-liquid contact is higher at locations nearer the stagnation line and with higher jet subcooling.

  11. Regulatory analysis for the resolution of Generic Issue 143: Availability of chilled water system and room cooling

    SciTech Connect

    Leung, V.T.

    1993-12-01

    This report presents the regulatory analysis for Generic Issue (GI-143), {open_quotes}Availability of Chilled Water System and Room Cooling.{close_quotes} The heating, ventilating, and air conditioning (HVAC) systems and related auxiliaries are required to provide control of environmental conditions in areas in light water reactor (LWR) plants that contain safety-related equipment. In some plants, the HVAC and chilled water systems serve to maintain a suitable environment for both safety and non-safety-related areas. Although some plants have an independent chilled water system for the safety-related areas, the heat removal capability often depends on the operability of other supporting systems such as the service water system or the component cooling water system. The operability of safety-related components depends upon operation of the HVAC and chilled water systems to remove heat from areas containing the equipment. If cooling to dissipate the heat generated is unavailable, the ability of the safety-related equipment to operate as intended cannot be assured. Typical components or areas in the nuclear power plant that could be affected by the failure of cooling from HVAC or chilled water systems include the (1) emergency switchgear and battery rooms, (2) emergency diesel generator room, (3) pump rooms for residual heat removal, reactor core isolation cooling, high-pressure core spray, and low-pressure core spray, and (4) control room. The unavailability of such safety-related equipment or areas could cause the core damage frequency (CDF) to increase significantly.

  12. Water-cooled hard-soldered kilowatt laser diode arrays operating at high duty cycle

    NASA Astrophysics Data System (ADS)

    Klumel, Genady; Karni, Yoram; Oppenhaim, Jacob; Berk, Yuri; Shamay, Moshe; Tessler, Renana; Cohen, Shalom; Risemberg, Shlomo

    2010-04-01

    High brightness laser diode arrays are increasingly found in defense applications either as efficient optical pumps or as direct energy sources. In many instances, duty cycles of 10- 20 % are required, together with precise optical collimation. System requirements are not always compatible with the use of microchannel based cooling, notwithstanding their remarkable efficiency. Simpler but effective solutions, which will not involve high fluid pressure drops as well as deionized water, are needed. The designer is faced with a number of challenges: effective heat removal, minimization of the built- in and operational stresses as well as precise and accurate fast axis collimation. In this article, we report on a novel laser diode array which includes an integral tap water cooling system. Robustness is achieved by all around hard solder bonding of passivated 940nm laser bars. Far field mapping of the beam, after accurate fast axis collimation will be presented. It will be shown that the design of water cooling channels , proper selection of package materials, careful design of fatigue sensitive parts and active collimation technique allow for long life time and reliability, while not compromising the laser diode array efficiency, optical power density ,brightness and compactness. Main performance characteristics are 150W/bar peak optical power, 10% duty cycle and more than 50% wall plug efficiency with less than 1° fast axis divergence. Lifetime of 0.5 Gshots with less than 10% power degradation has been proved. Additionally, the devices have successfully survived harsh environmental conditions such as thermal cycling of the coolant temperature and mechanical shocks.

  13. Hydroxyl carboxylate based non-phosphorus corrosion inhibition process for reclaimed water pipeline and downstream recirculating cooling water system.

    PubMed

    Wang, Jun; Wang, Dong; Hou, Deyin

    2016-01-01

    A combined process was developed to inhibit the corrosion both in the pipeline of reclaimed water supplies (PRWS) and in downstream recirculating cooling water systems (RCWS) using the reclaimed water as makeup. Hydroxyl carboxylate-based corrosion inhibitors (e.g., gluconate, citrate, tartrate) and zinc sulfate heptahydrate, which provided Zn(2+) as a synergistic corrosion inhibition additive, were added prior to the PRWS when the phosphate (which could be utilized as a corrosion inhibitor) content in the reclaimed water was below 1.7 mg/L, and no additional corrosion inhibitors were required for the downstream RCWS. Satisfactory corrosion inhibition was achieved even if the RCWS was operated under the condition of high numbers of concentration cycles. The corrosion inhibition requirement was also met by the appropriate combination of PO4(3-) and Zn(2+) when the phosphate content in the reclaimed water was more than 1.7 mg/L. The process integrated not only water reclamation and reuse, and the operation of a highly concentrated RCWS, but also the comprehensive utilization of phosphate in reclaimed water and the application of non-phosphorus corrosion inhibitors. The proposed process reduced the operating cost of the PRWS and the RCWS, and lowered the environmental hazard caused by the excessive discharge of phosphate. Furthermore, larger amounts of water resources could be conserved as a result.

  14. Holocene sediment dynamics on a cool-water carbonate shelf: Otway, southeastern Australia

    SciTech Connect

    Boreen, T.D.; James, N.P. )

    1993-07-01

    The Otway Shelf is covered by cool waters and veneered by bryozoan-dominated carbonate sediments. Radiocarbon dating and stratigraphy of shelf vibracores and slope gravity cores document late Pleistocene/Holocene deposition. Shelf sediments of the late Pleistocene high-stand are rare, either never having been deposited or having been removed during the following sea-level fall. During the subsequent lowstand the shelf was exposed, facies shifted basinward, and beach/dune complexes were constructed near the shelf edge. The deep shelf was characterized by nondeposition and hardground formation, and the shelf margin became locally erosional. Upper-slope bryozoan/sponge assemblages continued to grow actively, and lower-slope foraminifera and nannofossil ooze was increasingly enriched in hemipelagic terrigenous mud swept off the wide shelf. Coarse shelf debris and lowstand dune sands were erosively reworked and transported onto the upper slope and redistributed to deep-slope aprons during early transgression. The late Quaternary shelf record resembles that of flat-topped, warm-water platforms with Holocene sediment overlying Pleistocene/Tertiary limestone, but for different reasons. The slow growth potential, uniform profile of sediment production and distribution, and inability of constituent organisms to construct rigid frameworks favor maintenance of a shallow ramp profile and makes the cool-water carbonate system an excellent modern analog for interpretation of many ancient ramp successions.

  15. Chloride removal from recycled cooling water using ultra-high lime with aluminum process.

    PubMed

    Abdel-Wahab, Ahmed; Batchelor, Bill

    2002-01-01

    Chloride is a deleterious ionic species in cooling water systems because it promotes corrosion, and most of the scale and corrosion inhibitors are sensitive to chloride concentration in the water. Chloride can be removed from cooling water by precipitation as calcium chloroaluminate [Ca4Al2Cl2(OH)12]. A set of equilibrium experiments and one kinetic experiment were conducted to evaluate chloride removal using the ultra-high lime with aluminum (UHLA) process and to characterize the equilibrium conditions of calcium chloroaluminate precipitation. A total of 48 batch-equilibrium experiments were conducted on a 30 mM NaCl solution over a range of values for lime dose (0 to 200 mM) and sodium aluminate dose (0 to 100 mM). Experimental results showed that the UHLA process can remove chloride and that the formation of a calcium chloroaluminate solid phase is a reasonable mechanism that is able to adequately describe experimental results. An average value of the ion activity product of 10(-94.75) was obtained and can be used as an estimate of the solubility product for Ca4Al2Cl2(OH)12.

  16. The cast structure of a 7075 alloy produced by a water-cooling centrifugal casting method

    SciTech Connect

    Yeh, J.W. . Dept. of Materials Science and Engineering); Jong, S.H.

    1994-03-01

    A water-cooling centrifugal casting method was applied to cast the 7075 Al alloy to generate a much finer cast structure than that produced by conventional ingot casting methods. The effects of casting parameters, i.e., rotation speed, pouring temperature, water flow, and grain refiner, on casting structure were systematically studied so that the optimum casting condition and the solidification mechanism could be established. The typical cast structure along the thickness direction of a cast ring could be divided into four equiaxed zones, including the chill zone which is in contact with the mold wall. All zones have their characteristic grain size, morphology, and relative thickness, which are all dependent on the casting condition. The optimum casting condition yielding the finest structure available was found to be 3,000 rpm, 650 C, and sufficient water cooling. A uniform portion occupying 90 pct of the whole thickness and having a grain size of 17 [mu]m could be achieved under such a casting condition. When a grain refiner was added, the whole ring became further concentrated with grains of fine structure. A mechanism concerning the overall effects of rapid solidification, turbulent flow, and centrifugal force has been proposed for the present casting method and might explain the zone-structure formation and the effects of the casting parameters on microstructural features.

  17. Temperature-time distribution and thermal stresses on the RTG fins and shell during water cooling

    NASA Technical Reports Server (NTRS)

    Turner, R. H.

    1983-01-01

    Radioisotope thermoelectric generator (RTG) packages designed for space missions generally do not require active cooling. However, the heat they generate cannot remain inside of the launch vehicle bay and requires active removal. Therefore, before the Shuttle bay door is closed, the RTG coolant tubes attached to the heat rejection fins must be filled with water, which will circulate and remove most of the heat from the cargo bay. There is concern that charging a system at initial temperature around 200 C with water at 24 C can cause unacceptable thermal stresses in the RTG shell and fins. A computer model is developed to estimate the transient temperature distribution resulting from such charging. The thermal stresses resulting from the temperature gradients do not exceed the elastic deformation limit for the material. Since the simplified mathematical model for thermal stresses tends to overestimate stresses, it is concluded that the RTG can be cooled by introducing water at 24 C to the initially hot fin coolant tubes while the RTG is in the Shuttle cargo bay.

  18. Corrosion control when using secondary treated municipal wastewater as alternative makeup water for cooling tower systems.

    PubMed

    Hsieh, Ming-Kai; Li, Heng; Chien, Shih-Hsiang; Monnell, Jason D; Chowdhury, Indranil; Dzombak, David A; Vidic, Radisav D

    2010-12-01

    Secondary treated municipal wastewater is a promising alternative to fresh water as power plant cooling water system makeup water, especially in arid regions. Laboratory and field testing was conducted in this study to evaluate the corrosiveness of secondary treated municipal wastewater for various metals and metal alloys in cooling systems. Different corrosion control strategies were evaluated based on varied chemical treatment. Orthophosphate, which is abundant in secondary treated municipal wastewater, contributed to more than 80% precipitative removal of phosphorous-based corrosion inhibitors. Tolyltriazole worked effectively to reduce corrosion of copper (greater than 95% inhibition effectiveness). The corrosion rate of mild steel in the presence of free chlorine 1 mg/L (as Cl2) was approximately 50% higher than in the presence of monochloramine 1 mg/L (as Cl2), indicating that monochloramine is a less corrosive biocide th