WorldWideScience

Sample records for water currents

  1. Water Current Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tidal, river and ocean current observations collected by the U.S. Coast and Geodetic Survey. Period of record is late 1800s to mid-1980s.

  2. The Savonius Water Current Meter

    Science.gov (United States)

    1960-11-03

    the author visited the David Taylor Model Basin for the purpose of calibrating five (5) Savonius water current ,meter rotors in the range of .1 to 1...Iastitution of Oceanography. Figure 1 is a block diagram of the water current meter and its associated equipment. The details of the Savonius rotor are...an amplifier. The Savonius rotor functions as a salt water switch which varies the r-. coupling of the transformer thus it awplitude modulates the 100

  3. WaterWatch -- Current Water Resources Conditions

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — WaterWatch (http://waterwatch.usgs.gov) is a U.S. Geological Survey (USGS) World Wide Web site that displays maps, graphs, and tables describing real-time, recent,...

  4. Tidal power harnessing energy from water currents

    CERN Document Server

    Lyatkher, Victor

    2014-01-01

    As the global supply of conventional energy sources, such as fossil fuels, dwindles and becomes more and more expensive, unconventional and renewable sources of energy, such as power generation from water sources, is becoming more and more important.  Hydropower has been around for decades, but this book suggests new methods that are more cost-effective and less intrusive to the environment for creating power sources from rivers, the tides, and other sources of water.   The energy available from water currents is potentially much greater than society's needs.  Presenting a detailed discussi

  5. Current Water Issues Faced with Tianjin

    Institute of Scientific and Technical Information of China (English)

    刘柳

    2009-01-01

    Tianjin is the third biggest city in China,but currently facing a severe water shortage.Historically,due to Tianjin's geographic location it is a water rich city,but over the past 50 decades has become a water poor area.Over all both quality and quantity of Tianjin's water resource are declining.Recommendations arc made to resolve this water problem in different aspects.%天津作为中国的直辖市之一,目前面临着严重水资源短缺的问题.在历史上,因为它的地理位置,天津是水资源丰富的城市.然而近几十年来天津已经成为水资源极度匮乏地区.天津水资源的数量和质量都在急刷下降.在这篇文章中提出了一些建议来帮助解决这些水问题.

  6. Water- and foodborne viruses: current developments

    African Journals Online (AJOL)

    water and lack of adequate sanitation.3 In South Africa approximately. 12 million ... are without sanitation. Food sources can .... individuals >1 year of age and watery diarrhoea in children <1 ... HAV infection include improved personal hygiene ...

  7. Turbulent wind waves on a water current

    Directory of Open Access Journals (Sweden)

    M. V. Zavolgensky

    2008-05-01

    Full Text Available An analytical model of water waves generated by the wind over the water surface is presented. A simple modeling method of wind waves is described based on waves lengths diagram, azimuthal hodograph of waves velocities and others. Properties of the generated waves are described. The wave length and wave velocity are obtained as functions on azimuth of wave propagation and growth rate. Motionless waves dynamically trapped into the general picture of three dimensional waves are described. The gravitation force does not enter the three dimensional of turbulent wind waves. That is why these waves have turbulent and not gravitational nature. The Langmuir stripes are naturally modeled and existence of the rogue waves is theoretically proved.

  8. Review of coastal currents in Southern African waters

    CSIR Research Space (South Africa)

    Harris, TFW

    1978-08-01

    Full Text Available A review has been made of existing knowledge of the coastal currents in Southern African waters between Pretoria to Oudtshoorn on the northeast border, and the Orange River on the west coast. These waters have been divided into five sectors...

  9. Fresh water-salt water density currents, a major cause of siltation in estuaries

    National Research Council Canada - National Science Library

    Schultz, E.A; Simmons, H.B

    1957-01-01

    ... the effects of changing the upland discharge into estuaries, rivers, and harbours where the fresh water-salt water density currents are present in some degree, and in some cases are the major cause of siltation; and 4...

  10. The current state of water resources of Transcarpathia

    Directory of Open Access Journals (Sweden)

    V. І. Nikolaichuk

    2015-07-01

    sanitary rules and regulations by the most of indicators of general health and specific indices. 19.0% of total water supply systems fail to meet the sanitary norms and regulations, in particular: 14.2% for the lack of sanitary protection zones; 1.9% because of unavailability of the necessary integrated treatment facilities, and 7.6% by the reason of absence of disinfecting plants. Possible ways of avoiding the depletion of water bodies are preventive water protection measures aimed at preventing or limiting pollution, water contamination and depletion; besides, it is necessary to educate people explaning them the current state and possible consequences of thoughtless water consumption.

  11. The potential versus current state of water splitting with hematite.

    Science.gov (United States)

    Zandi, Omid; Hamann, Thomas W

    2015-09-21

    This review describes the potential of hematite as a photoanode material for photoelectrochemical (PEC) water splitting. The current understanding of key loss-mechanisms of hematite are introduced and correlated to performance enhancement strategies. The significant voltage loss associated with overcoming the competitive water oxidation and surface state recombination has recently been surmounted through a combination of high temperature annealing and surface modification with water oxidation catalysts. Substantial efforts have been made at nanostructuring electrodes to increase the charge separation efficiency without sacrificing light absorption. Even in optimized nanostructured electrodes, however, charge separation continues to be the primary barrier to achieving efficient water splitting with hematite. Specifically, significant depletion region recombination results in voltage dependant photocurrent which constrains the fill factor. Thus, future directions to enhance the efficiency of hematite electrodes are discussed with an emphasis on circumventing depletion region recombination.

  12. Index of current water-resources activities in Ohio, 1985

    Science.gov (United States)

    Eberle, Michael

    1985-01-01

    This report summarizes the U. S. Geological Survey 's Water Resources Division 's program in Ohio in 1985. The work of the Ohio District is carried out through the District office in Columbus and a field office in New Philadelphia. Collection of basic data needed for continuing determination and evaluation of the quantity, quality, and use of Ohio 's water resources is the responsibility of the District 's Hydrologic Surveillance Section. The Hydrologic Investigations Section conducts analytical and interpretive water-resource appraisals describing the occurrence, availability, and the physical, chemical, and biological characteristics of surface and groundwater. In addition to introductory material describing the structure of the Ohio District, information is presented on current projects, sites at which basic surface- and groundwater data are collected , and reports of Ohio 's water resources published by the U.S. Geological Survey and cooperating agencies. (USGS)

  13. Anthropogenic currents and shoreline water quality in Avalon Bay, California.

    Science.gov (United States)

    Ho, Lin C; Litton, Rachel M; Grant, Stanley B

    2011-03-15

    Shoreline concentrations of fecal indicator bacteria (FIB) and fecal indicator viruses (FIV) in Avalon Bay (Catalina Island, California) display a marked diurnal pattern (higher at night and lower during the day) previously attributed to the tidal flux of sewage-contaminated groundwater and the tidal washing of contaminated sediments, coupled with light and dark die-off of FIB and FIV (Boehm, et al., Environ. Sci. Technol. 2009, 43, 8046-8052). In this paper we document the existence of strong (peak velocities between 20 to 40 cm/s) transient currents in the nearshore waters of Avalon Bay that occur between 07:00 and 20:00 each day. These currents, which have a significant onshore component, are generated by anthropogenic activities in the Bay, including prop wash from local boat traffic and the docking practices of large passenger ferries. A budget analysis carried out on simultaneous measurements of FIB at two cross-shore locations indicates that anthropogenic currents contribute to the diurnal cycling of FIB concentrations along the shoreline, by transporting relatively unpolluted water from offshore toward the beach. The data and analysis presented in this paper support the idea that anthropogenic currents represent a significant, and previously overlooked, source of variability in shoreline water quality.

  14. Current perspectives in contaminant hydrology and water resources sustainability

    Science.gov (United States)

    Bradley, Paul M.

    2013-01-01

    Human society depends on liquid freshwater resources to meet drinking, sanitation and hygiene, agriculture, and industry needs. Improved resource monitoring and better understanding of the anthropogenic threats to freshwater environments are critical to efficient management of freshwater resources and ultimately to the survival and quality of life of the global human population. This book helps address the need for improved freshwater resource monitoring and threat assessment by presenting current reviews and case studies focused on the fate and transport of contaminants in the environment and on the sustainability of groundwater and surface-water resources around the world. It is intended for students and professionals working in hydrology and water resources management.

  15. Monitoring dental-unit-water-line output water by current in-office test kits.

    Science.gov (United States)

    Lal, Sham; Singhrao, Sim K; Bricknell, Matt; Pearce, Mark; Morton, L H Glyn; Ahmed, Waqar; Crean, St John

    2014-08-01

    The importance of monitoring contamination levels in the output water of dental-unit-water-lines (DUWLs) is essential as they are prone to developing biofilms that may contaminate water that is used to treat patients, with opportunistic pathogens such as species of Legionella, Pseudomonas and others. Dentists and practice staff are also at risk of being infected by means of cross-infection due to aerosols generated from DUWL water. The unit of measurement for the microbial contamination of water by aerobic mesophilic heterotrophic bacteria is the colony-forming unit per millilitre (cfu/ml) of water. The UK has its own guidelines set by the Department of Health for water discharged from DUWL to be between 100 and 200 cfu/ml of water. The benchmark or accepted standard laboratory test is by microbiological culture on R2A agar plates. However, this is costly and not convenient for routine testing in dental practices. A number of commercial indicator tests are used in dental surgeries, but they were not developed for the dental market and serve only to indicate gross levels of contamination when used outside of the manufacturer's recommended incubation period. The aim of this article is to briefly review the universal problem of DUWL contamination with microbial biofilms and to update dental professionals on the availability of currently available commercial in-office monitoring systems for aerobic mesophilic heterotrophic bacteria and to discuss their limitations for testing water samples in assuring compliance with recommended guidelines.

  16. Analysis of Water Properties and Geostrophic Currents in Fiji Waters Before and After Tropical Cyclone Gene

    Directory of Open Access Journals (Sweden)

    Shivneel Prasad

    2009-01-01

    Full Text Available Problem statement: Water properties influence ocean primary production and drive the ocean food chain. This study depicts changes in temperature and salinity and its effects on geostrophic currents near Fiji before and after Tropical Cyclone (TC Gene. Approach: Available Argo float data from 6 January-4 February 2008 were used for analysis since TC Gene passed the area on 28 January 2008. The dynamic height and geostrophic current data were obtained from the Aviso website. Results: The thermocline depth increased by 20 m after the cyclone. A temperature drop of approximately 3°C was also noticed in the study area. Using this drop in temperature, the heat energy removed by the cyclone was calculated to be 0.095 MWh m-2. Salinity profiles showed an increase of 0.42 psu to a depth of 35 m after the cyclone. Changes in salinity and temperature of water may also cause changes in the dynamic height and in turn the geostrophic current patterns. After plotting the geostrophic current vectors, it was observed that the current patterns changed significantly after TC gene. Seasonal changes were also evident before the cyclone. Conclusion/Recommendations: Although the lifespan of TC gene was short, its effect on the water properties near Fiji was significant as it completely changed the geostrophic current patterns and this can have a huge implication on marine life.

  17. CURRENT ENVIRONMENT STATE OF COASTAL MARINE WATER OF DAGESTAN

    Directory of Open Access Journals (Sweden)

    S. A. Guseinova

    2014-01-01

    Full Text Available Aim. We analysed current environmental state of the Dagestan coast of the Caspian Sea. Data on the spatial variability of contaminants in the coastal areas of the Dagestan segment of the Caspian Sea from the northern districts (Lopatin to the central (Sulak coastal land and, further, to the southern district (within Russian subsoil management confirm that it is caused by irregular contamination of the sea by above-ground sources. Location. Dagestan coastal area of the Caspian SeaMethods. Concentration analysis of background contamination of chemical agents in the Dagestan coastal water from northern districts (Lopatin to southern (Sulak coastal land during the period between 2004 and 2007.Results. Data on the spatial variability of contaminants in the coastal areas of the Dagestan segment of the Caspian Sea from the northern districts (Lopatin to the central (Sulak coastal land and, further, to the southern district (within Russian subsoil management confirm that it is caused by irregular contamination of the sea by above-ground sources.Main conclusions. The envisaged large-scale hydrocarbon resource development requires regular monitoring of sea currents on Makhachkala, Izberbash and Derbent roads.

  18. Overview of water resource assessment in South Africa: Current ...

    African Journals Online (AJOL)

    is essential to planners and designers of water supply schemes and those ... Particular emphasis is given to the evolution of the computer as an ... we now call the historical firm yield. ..... In their article, Strategic planning for water resources in.

  19. Numerical study on water waves and wave-induced longshore currents in Obaköy coastal water

    Institute of Scientific and Technical Information of China (English)

    TANG Jun; LYU Yigang; SHEN Yongming

    2014-01-01

    In this paper, the water waves and wave-induced longshore currents in Obaköy coastal water which is lo-cated at the Mediterranean coast of Turkey were numerically studied. The numerical model is based on the parabolic mild-slope equation for coastal water waves and the nonlinear shallow water equation for the wave-induced currents. The wave transformation under the effects of shoaling, refraction, diffraction and breaking is considered, and the wave provides radiation stresses for driving currents in the model. The numerical results for the water wave-induced longshore currents were validated by the measured data to demonstrate the efficiency of the numerical model. Then the water waves and longshore currents induced by the waves from main directions were numerically simulated and analyzed based on the numerical re-sults. The numerical results show that the movement of the longshore currents was different while the wave propagated to a coastal zone from different directions.

  20. Current status on marine litter indicators in Nordic waters

    DEFF Research Database (Denmark)

    Strand, Jakob; Tairova, Zhanna; Magnusson, Kerstin

    Status for project on Marine litter in the Nordic waters. This includes a review of Nordic studies on marine litter indicators. Various studies as part of either research or existing monitoring have provided information on occurrence of marine litter in Nordic waters from Baltic Sea to the Arctic....

  1. Semiconductor photocatalysts for water oxidation: current status and challenges.

    Science.gov (United States)

    Yang, Lingling; Zhou, Han; Fan, Tongxiang; Zhang, Di

    2014-04-21

    Artificial photosynthesis is a highly-promising strategy to convert solar energy into hydrogen energy for the relief of the global energy crisis. Water oxidation is the bottleneck for its kinetic and energetic complexity in the further enhancement of the overall efficiency of the artificial photosystem. Developing efficient and cost-effective photocatalysts for water oxidation is a growing desire, and semiconductor photocatalysts have recently attracted more attention due to their stability and simplicity. This article reviews the recent advancement of semiconductor photocatalysts with a focus on the relationship between material optimization and water oxidation efficiency. A brief introduction to artificial photosynthesis and water oxidation is given first, followed by an explanation of the basic rules and mechanisms of semiconductor particulate photocatalysts for water oxidation as theoretical references for discussions of componential, surface structure, and crystal structure modification. O2-evolving photocatalysts in Z-scheme systems are also introduced to demonstrate practical applications of water oxidation photocatalysts in artificial photosystems. The final part proposes some challenges based on the dynamics and energetics of photoholes which are fundamental to the enhancement of water oxidation efficiency, as well as on the simulation of natural water oxidation that will be a trend in future research.

  2. Mapping current and future European public water withdrawals and consumption

    Science.gov (United States)

    Vandecasteele, I.; Bianchi, A.; Silva, F. Batista e.; Lavalle, C.; Batelaan, O.

    2014-02-01

    In Europe, public water withdrawals make up on average 30% and in some cases up to 60% of total water withdrawals. These withdrawals are becoming increasingly important with growing population density; hence there is a need to understand the spatial and temporal trends involved. Pan-European public/municipal water withdrawals and consumption were mapped for 2006 and forecasted for 2030. Population and tourism density were assumed to be the main driving factors for withdrawals. Country-level statistics on public water withdrawals were disaggregated to a combined population and tourism density map (the "user" density map) computed for 2006. The methodology was validated using actual regional withdrawal statistics from France for 2006. The total absolute error (TAE) calculated was proven to be reduced by taking into account the tourism density in addition to the population density. In order to forecast the map to 2030 we considered a reference scenario where per capita withdrawals were kept constant in time. Although there are large variations from region to region, this resulted in a European average increase of water withdrawals of 16%. If we extrapolate the average reduction in per capita withdrawals seen between 2000 and 2008, we forecast a reduction in average total water withdrawals of 4%. Considering a scenario where all countries converge to an optimal water use efficiency, we see an average decrease of 28%.

  3. Performance of a Straight-Bladed Water-Current Turbine

    OpenAIRE

    Sule, Luther

    2014-01-01

    The most renewable energy used in Indonesia is coming from hydro energy. The hydro energy available in Indonesia is about75000-76000MW. From the whole water energy available in Indonesia there was just about 3,783MW being harnest for large scale power plants and about 220 MW for small-scale power plants. One of the small- scale hydro energy sources is from a small river which has a water speed range between 0.01 m/s to 2.8 m/s. Although having only a low water speed, the energ...

  4. 46 CFR 11.713 - Requirements for maintaining current knowledge of waters to be navigated.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Requirements for maintaining current knowledge of waters... § 11.713 Requirements for maintaining current knowledge of waters to be navigated. (a) If a first class... current knowledge of the route. Persons using this method of re-familiarization shall certify,...

  5. Mapping current and future European public water withdrawals and consumption

    Directory of Open Access Journals (Sweden)

    I. Vandecasteele

    2013-07-01

    Full Text Available In Europe, public water withdrawals make up on average 30%, and in some cases up to 60% of total water withdrawals. These withdrawals are becoming increasingly important with growing population density; hence there is a need to understand the spatial and temporal trends involved. Pan-European public/municipal water withdrawals and consumption were mapped for 2006 and forecasted for 2030. Population and tourism density were assumed to be the main driving factors for withdrawals. Country-level statistics on public water withdrawals were disaggregated to a combined population and tourism density map (the "user" density map computed for 2006. In order to forecast the map to 2030 we assumed the water withdrawals per user to remain constant in time, so that the future withdrawals reflected the projected population and tourism trends. The methodology was validated using actual regional withdrawal statistics from France for 2006. The Total Absolute Error (TAE calculated was proven to be reduced by taking into account the tourism density in addition to the population density. Our results show that although there are large variations from region to region, in general public water withdrawals will increase significantly over the period 2006 to 2030. The European average increase is 16%, with a maximal increase of 53% in Ireland.

  6. Microbial Source Tracking: Current and Future Molecular Tools in Microbial Water Quality Forensics

    Science.gov (United States)

    Current regulations in the United States stipulate that the microbial quality of waters used for consumption and recreational activities should be determined regularly by measuring microbial indicators of fecal pollution. Hence, the microbial risk associated with these waters is...

  7. Analysis of Mixing of Pollutants in Water Waves and Currents

    Institute of Scientific and Technical Information of China (English)

    YUAN Li-rong; SHEN Yong-ming; TANG Jun

    2007-01-01

    A vertical two-dimensional turbulence numerical model for the interaction of waves and currents is developed in the paper based on the nonlinear two-equation k-ε model with the VOF method.The one-dimensional equivalent advection velocity and equivalent mixing coefficient are defined and the solving process is introduced: The pollutant concentration field,generated by an instant source in waves and currents,is calculated with the model,and then the equivalent advection velocity and equivalent mixing coefficient are obtained by calculating the time derivative of the mean and variance of pollutant concentration probability distribution.The effects of wave period and wave height on the equivalent mixing coefficient for waves and wave-currents are also investigated.

  8. SARAL/Altika for inland water: current and potential applications

    Science.gov (United States)

    Tarpanelli, Angelica; Brocca, Luca; Barbetta, Silvia; Moramarco, Tommaso; Santos da Silva, Joécila; Calmant, Stephane

    2015-04-01

    Although representing less than 1% of the total amount of water on Earth the freshwater is essential for terrestrial life and human needs. Over one third of the world's population is not served by adequate supplies of clean water and for this reason freshwater wars are becoming one of the most pressing environmental issues exacerbating the already difficult tensions between the riparian nations. Notwithstanding the foregoing, we have surprisingly poor knowledge of the spatial and temporal dynamics of surface discharge. In-situ gauging networks quantify the instantaneous water volume in the main river channels but provide few information about the spatial dynamics of surface water extent, such as floodplain flows and the dynamics of wetlands. The growing reduction of hydrometric monitoring networks over the world, along with the inaccessibility of many remote areas and the difficulties for data sharing among developing countries feed the need to develop new procedures for river discharge estimation based on remote sensing technology. The major challenge in this case is the possibility of using Earth Observation data without ground measurements. Radar altimeters are a valuable tool to retrieve hydrological information from space such as water level of inland water. More than a decade of research on the application of radar altimetry has demonstrated its advantages also for monitoring continental water, providing global coverage and regular temporal sampling. The high accuracy of altimetry data provided by the latest spatial missions and the convincing results obtained in the previous applications suggest that these data may be employed for hydraulic/hydrological applications as well. If used in synergy with the modeling, the potential benefits of the altimetry measurements can grow significantly. The new SARAL French-Indian mission, providing improvements in terms of vertical accuracy and spatial resolution of the onboard altimeter Altika, can offer a great

  9. BAYER COUNTER CURRENT SYSTEMS IN COMPARISON WITH CONVENTIONAL CO—CURRENT SYSTEM IN THE FIELD OF WATER TREATMENT

    Institute of Scientific and Technical Information of China (English)

    Mitschker.A; RauchfuB.K

    1994-01-01

    From an economical point of view both the quality of the ion exchange resins and the technology used in the field of industrial water treatment are important for a successful performance.In general,two different technologies have been established on the market:The main differneces between the CO-and counter current technologes will be discussed and data concerning the requirement of chemicals for regeneration and the quality of the deionized water will be opposed.In addition several different varieties of the modern counter current technologies,developed and patented by Bayer AG,will be described and the advantages,depending on the application and the demand on the quality of the deionized water,pointed out .In view of stronger regulations concerning the consumption of regeneration chemicals,and waste water,and also because of the superior quality of the produced water,the market share of counter current technologies will continue to increase world-wide.

  10. Nonlinear Wave-Currents interactions in shallow water

    CERN Document Server

    Lannes, David

    2015-01-01

    We study here the propagation of long waves in the presence of vorticity. In the irrotational framework, the Green-Naghdi equations (also called Serre or fully nonlinear Boussinesq equations) are the standard model for the propagation of such waves. These equations couple the surface elevation to the vertically averaged horizontal velocity and are therefore independent of the vertical variable. In the presence of vorticity, the dependence on the vertical variable cannot be removed from the vorticity equation but it was however shown in [?] that the motion of the waves could be described using an extended Green-Naghdi system. In this paper we propose an analysis of these equations, and show that they can be used to get some new insight into wave-current interactions. We show in particular that solitary waves may have a drastically different behavior in the presence of vorticity and show the existence of solitary waves of maximal amplitude with a peak at their crest, whose angle depends on the vorticity. We als...

  11. Concentration polarization with monopolar ion exchange membranes: current-voltage curves and water dissociation

    NARCIS (Netherlands)

    Krol, J.J.; Wessling, M.; Strathmann, H.

    1999-01-01

    Concentration polarization is studied using a commercial anion and cation exchange membrane. Current¿voltage curves show the occurrence of an overlimiting current. The nature of this overlimiting current is investigated in more detail, especially with respect to the contribution of water dissociatio

  12. Safe access to safe water in low income countries: water fetching in current times.

    Science.gov (United States)

    Sorenson, Susan B; Morssink, Christiaan; Campos, Paola Abril

    2011-05-01

    A substantial portion of the world's population does not have ready access to safe water. Moreover, obtaining water may involve great expense of time and energy for those who have no water sources in or near home. From an historical perspective, with the invention of piped water, fetching water has only recently become largely irrelevant in many locales. In addition, in most instances, wells and clean surface water were so close by that fetching was not considered a problem. However, population growth, weather fluctuations and social upheavals have made the daily chore of carrying water highly problematic and a public health problem of great magnitude for many, especially women, in the poor regions and classes of the world. In this paper, we consider gender differences in water carrying and summarize data about water access and carrying from 44 countries that participated in the Multiple Indicator Cluster Survey (MICS) program. Women and children are the most common water carriers, and they spend considerable time (many trips take more than an hour) supplying water to their households. Time is but one measure of the cost of fetching water; caloric expenditures, particularly during droughts, and other measures that affect health and quality of life must be considered. The full costs of fetching water must be considered when measuring progress toward two Millennium Development Goals--increasing access to safe drinking water and seeking an end to poverty.

  13. Water Resources and Agricultural Water Use in the North China Plain: Current Status and Management Options

    Science.gov (United States)

    Serious water deficits with deteriorating environmental quality are threatening agricultural sustainability in the North China Plain (NCP). This paper addresses spatial and temporal availability of water resources in the NCP, and identifies the effects of soil management, irrigation and crop genetic...

  14. CURRENT STATE AND PROBLEMS OF DEVELOPMENT OF THE WATER MANAGEMENT IN THE SOUTH OF RUSSIA

    Directory of Open Access Journals (Sweden)

    T. A. Shebzukhova

    2017-01-01

    Full Text Available Aim. The aim is to give a current and retrospective assessment of the state of water resources in the South of Russia and identify key problems in their use.Methods. Based on the analysis of dynamic and territorial series of data presented in government reports and the Central Statistical Database of the Federal State Statistics Service, we conducted diagnostic studies of the current and dynamic state of water resources use in the sub-federal units of the Russian Federation.Findings. The key problems in the functioning of the water sector in the southern regions are: natural water scarcity, large-scale transfers and artificial regulation of the river flows, significant loss of water during transport, large-scale discharge of contaminated sewage and poor quality of water. A significant interregional asymmetry in the water sector of the South of Russia is being tested.Conclusions. The key water-related contradiction in the South of the Russian Federation lies in the high water intensity of the meta-regional economy due to agricultural specialization, limited opportunities for the use of circulating systems, as well as significant losses of water during transportation in conditions of naturally caused scarcity and poor quality of potable waters

  15. The Indus basin in the framework of current and future water resources management

    Science.gov (United States)

    Laghari, A. N.; Vanham, D.; Rauch, W.

    2012-04-01

    The Indus basin is one of the regions in the world that is faced with major challenges for its water sector, due to population growth, rapid urbanisation and industrialisation, environmental degradation, unregulated utilization of the resources, inefficient water use and poverty, all aggravated by climate change. The Indus Basin is shared by 4 countries - Pakistan, India, Afghanistan and China. With a current population of 237 million people which is projected to increase to 319 million in 2025 and 383 million in 2050, already today water resources are abstracted almost entirely (more than 95% for irrigation). Climate change will result in increased water availability in the short term. However in the long term water availability will decrease. Some current aspects in the basin need to be re-evaluated. During the past decades water abstractions - and especially groundwater extractions - have augmented continuously to support a rice-wheat system where rice is grown during the kharif (wet, summer) season (as well as sugar cane, cotton, maize and other crops) and wheat during the rabi (dry, winter) season. However, the sustainability of this system in its current form is questionable. Additional water for domestic and industrial purposes is required for the future and should be made available by a reduction in irrigation requirements. This paper gives a comprehensive listing and description of available options for current and future sustainable water resources management (WRM) within the basin. Sustainable WRM practices include both water supply management and water demand management options. Water supply management options include: (1) reservoir management as the basin is characterised by a strong seasonal behaviour in water availability (monsoon and meltwater) and water demands; (2) water quality conservation and investment in wastewater infrastructure; (3) the use of alternative water resources like the recycling of wastewater and desalination; (4) land use

  16. The Indus basin in the framework of current and future water resources management

    Directory of Open Access Journals (Sweden)

    A. N. Laghari

    2012-04-01

    Full Text Available The Indus basin is one of the regions in the world that is faced with major challenges for its water sector, due to population growth, rapid urbanisation and industrialisation, environmental degradation, unregulated utilization of the resources, inefficient water use and poverty, all aggravated by climate change. The Indus Basin is shared by 4 countries – Pakistan, India, Afghanistan and China. With a current population of 237 million people which is projected to increase to 319 million in 2025 and 383 million in 2050, already today water resources are abstracted almost entirely (more than 95% for irrigation. Climate change will result in increased water availability in the short term. However in the long term water availability will decrease. Some current aspects in the basin need to be re-evaluated. During the past decades water abstractions – and especially groundwater extractions – have augmented continuously to support a rice-wheat system where rice is grown during the kharif (wet, summer season (as well as sugar cane, cotton, maize and other crops and wheat during the rabi (dry, winter season. However, the sustainability of this system in its current form is questionable. Additional water for domestic and industrial purposes is required for the future and should be made available by a reduction in irrigation requirements. This paper gives a comprehensive listing and description of available options for current and future sustainable water resources management (WRM within the basin. Sustainable WRM practices include both water supply management and water demand management options. Water supply management options include: (1 reservoir management as the basin is characterised by a strong seasonal behaviour in water availability (monsoon and meltwater and water demands; (2 water quality conservation and investment in wastewater infrastructure; (3 the use of alternative water resources like the recycling of wastewater and desalination; (4

  17. Urban water : harvesting rainwater at household level to improve the current water metabolism in Cuenca, Ecuador

    OpenAIRE

    Godoy Gacha, Juan Diego

    2015-01-01

    With a global population about 7 billion people and their continued growth are pressuring global natural resources, in freshwater matter this pressure is altering both the river flows; timing season of water flows; and spatial patterns in order to meet human demands both in urban as rural areas. However, water stress in urban areas are increasing and expectations by 2050 are grim with a global urban development by 70 percent moreover urbanization rate expected by 2030 in Latin America is 80 p...

  18. Transient response of microbial communities in a water well field to application of an impressed current.

    Science.gov (United States)

    Medihala, P G; Lawrence, J R; Swerhone, G D W; Korber, D R

    2013-02-01

    Deterioration of water wells due to clogging and corrosion over time is a common problem where solutions may be costly and ineffective. Pilot studies have suggested that impressed current or cathodic protection may be used to reduce microbially-induced declines in water well performance. Two water wells in an alluvial aquifer close to the North Saskatchewan River were selected to study the response of subsurface microbial communities to the application of an impressed current as an anti-fouling technology. The treated well was exposed to an impressed current while the untreated well was used as a reference site. Biofilms grown on in situ coupons under the influence of the impressed current were significantly (p anti-fouling technology but actually promoted both microbial growth and physical clogging in this aquifer.

  19. Conditional short-crested waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2002-01-01

    For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes´ wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected linear short-crested wave riding on a uniform current is given. The analysis is based on the conventional shallow water Airy wave theory and the direction of the main wind...... direction can make any direction with the current. A consistent derivation of the wave spectrum taking into account current and finite water depth is used. The numerical results show a significant effect of the water depth, the directional spreading and the current on the conditional mean wave profile...

  20. The Effect of Water on the Flow of Stress-Activated Electric Currents through Rocks

    Science.gov (United States)

    Jahoda, A. M.; Cyr, G. G.; Dahlgren, R.; Freund, F. T.

    2011-12-01

    When igneous or high-grade metamorphic rocks are subjected to deviatoric stresses, dormant defects in the matrix of common rock-forming minerals become activated. These defects consist of pairs of oxygen anions in the 1- valence state, e.g. peroxy links such as O3Si-OO-SiO3. When a peroxy bond breaks, O3Si-O:O-SiO3, an electron is transferred from a neighboring O2- causing the donor oxygen, now O-, to turn into a defect electron, also known as a positive hole, that can propagate as a highly mobile positive charge through the rocks1. The current outflow is driven by the battery potential that builds up during this process. The question is how this electric current through rocks is affected by water. When positive holes flow into bulk water, they oxidize H2O to H2O2 and are thereby consumed2. This electrochemical reaction is driven by the potential drop across the rock-water interface. However, no such potential drop occurs across water that fills pores inside the rocks along the path of the electronic charge carriers. We present evidence that the presence of water in the pore space does indeed not "kill" the current flow. This observation leads to the conclusion that stress-activated positive hole currents should be able to flow through water-saturated rocks maybe as well as, possibly even better than through dry rocks. 1 Freund, F. T., et al.: Electric currents streaming out of stressed igneous rocks - A step towards understanding pre-earthquake low frequency EM emissions, Phys. Chem. Earth, 2006, 31, 389-396. 2 Balk, M., et al.: Oxidation of water to hydrogen peroxide at the rock-water interface due to stress-activated electric currents in rocks, Earth Planet. Sci. Lett. 2009, 283, 87-92

  1. Current meter data from moored current meter casts in the Coastal Waters of California from 12 April 1981 - 01 April 1983 (NODC Accession 8400159)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of California from April 12, 1981 to April 1, 1983. Data were submitted by...

  2. The Atlantic Water boundary current in the Nansen Basin: Transport and mechanisms of lateral exchange

    Science.gov (United States)

    Vâge, Kjetil; Pickart, Robert S.; Pavlov, Vladimir; Lin, Peigen; Torres, Daniel J.; Ingvaldsen, Randi; Sundfjord, Arild; Proshutinsky, Andrey

    2016-09-01

    Data from a shipboard hydrographic survey near 30°E in the Nansen Basin of the Arctic Ocean are used to investigate the structure and transport of the Atlantic Water boundary current. Two high-resolution synoptic crossings of the current indicate that it is roughly 30 km wide and weakly middepth-intensified. Using a previously determined definition of Atlantic Water, the transport of this water mass is calculated to be 1.6 ± 0.3 Sv, which is similar to the transport of Atlantic Water in the inner branch of the West Spitsbergen Current. At the time of the survey a small anticyclonic eddy of Atlantic Water was situated just offshore of the boundary current. The data suggest that the feature was recently detached from the boundary current, and, due to compensating effects of temperature and salinity on the thermal wind shear, the maximum swirl speed was situated below the hydrographic property core. Two other similar features were detected within our study domain, suggesting that these eddies are common and represent an effective means of fluxing warm and salty water from the boundary current into the interior. An atmospheric low-pressure system transiting south of our study area resulted in southeasterly winds prior to and during the field measurements. A comparison to hydrographic data from the Pacific Water boundary current in the Canada Basin under similar atmospheric forcing suggests that upwelling was taking place during the survey. This provides a second mechanism related to cross-stream exchange of heat and salt in this region of the Nansen Basin.

  3. Characteristics of the cold-water belt formed off Soya Warm Current

    Science.gov (United States)

    Ishizu, Miho; Kitade, Yujiro; Matsuyama, Masaji

    2008-12-01

    We examined the data obtained by acoustic Doppler current profiler, conductivity-temperature-depth profiler, and expendable bathythermograph observations, which were collected in the summers of 2000, 2001, and 2002, to clarify the characteristics of the cold-water belt (CWB), i.e., lower-temperature water than the surrounding water extending from the southwest coast of Sakhalin along the offshore side of Soya Warm Current (SWC) and to confirm one of the formation mechanisms of the CWB as suggested by our previous study, i.e., the upwelling due to the convergence of bottom Ekman transport off the SWC region. The CWB was observed at about 30 km off the coast, having a thickness of 14 m and a minimum temperature of 12°C at the sea surface. The CWB does not have the specific water mass, but is constituted of three representative water types off the northeast coast of Hokkaido in summer, i.e., SWC water, Fresh Surface Okhotsk Sea Water, and Okhotsk Sea Intermediate Water. In a comparison of the horizontal distributions of current and temperature, the CWB region is found to be advected to the southeast at an average of 40 ± 29% of the maximum current velocity of the SWC. The pumping speed due to the convergence of the bottom Ekman transport is estimated as (1.5-3.0) × 10-4 m s-1. We examined the mixing ratio of the CWB, and the results implied that the water mass of the CWB is advected southeastward and mixes with a water mass upwelling in a different region off SWC.

  4. Water Utility Management Strategies in Turkey: The current situation and the challenges

    Science.gov (United States)

    Alp, E.; Aksoy, M. N.; Koçer, B.

    2013-12-01

    As the effects of climate change becomes more prominent, current challenges related to water and wastewater management is becoming more serious. Providing water that satisfies environmental and safety standards in terms of quantity and quality is needed to maintain human life without compromising the need of future generations. Besides providing safe and affordable water, necessary treatment should be achieved according to several important factors such as receiving body standards, discharge standards, water reuse options. Therefore, management of water becomes more crucial than ever that states have to provide accessibility of safe water with affordable cost to its citizens with the means of effective utility management, including water treatment facilities, wastewater treatment facilities, water supply facilities and water distribution systems. Water utilities encounter with several challenges related to cost, infrastructure, population, legislation, workforce and resource. This study aims to determine the current situation and the necessary strategies to improve utility management in Turkish municipalities in a sustainable manner. US Environment Protection Agency (EPA) has formed a tool on effective utility management that assists utilities to provide a solution for both current and future challenges. In this study, we used EPA's guidelines and developed a survey consists of 60 questions under 10 sub-topics (Product Quality, Employee & Leadership Development, Stakeholder Understanding & Support, Operational Optimization, Infrastructure Stability, Financial Viability, Community Sustainability, Customer Satisfaction, Operational Resiliency, and Water Resource Adequacy). This survey was sent to the managers of 25 metropolitan municipalities in Turkey to assess the current condition of municipalities. After the evaluation of the survey results for each topic, including the importance given by managers, facilities were rated according to their level of achievement

  5. Density currents in the Chicago River: Characterization, effects on water quality, and potential sources

    Science.gov (United States)

    Jackson, P. Ryan; Garcia, Carlos M.; Oberg, Kevin A.; Johnson, Kevin K.; Garcia, Marcelo H.

    2008-01-01

    Bidirectional flows in a river system can occur under stratified flow conditions and in addition to creating significant errors in discharge estimates, the upstream propagating currents are capable of transporting contaminants and affecting water quality. Detailed field observations of bidirectional flows were made in the Chicago River in Chicago, Illinois in the winter of 2005-06. Using multiple acoustic Doppler current profilers simultaneously with a water-quality profiler, the formation of upstream propagating density currents within the Chicago River both as an underflow and an overflow was observed on three occasions. Density differences driving the flow primarily arise from salinity differences between intersecting branches of the Chicago River, whereas water temperature is secondary in the creation of these currents. Deicing salts appear to be the primary source of salinity in the North Branch of the Chicago River, entering the waterway through direct runoff and effluent from a wastewater-treatment plant in a large metropolitan area primarily served by combined sewers. Water-quality assessments of the Chicago River may underestimate (or overestimate) the impairment of the river because standard water-quality monitoring practices do not account for density-driven underflows (or overflows). Chloride concentrations near the riverbed can significantly exceed concentrations at the river surface during underflows indicating that full-depth parameter profiles are necessary for accurate water-quality assessments in urban environments where application of deicing salt is common.

  6. Dye-Sensitized Photocatalytic Water Splitting and Sacrificial Hydrogen Generation: Current Status and Future Prospects

    Directory of Open Access Journals (Sweden)

    Pankaj Chowdhury

    2017-05-01

    Full Text Available Today, global warming and green energy are important topics of discussion for every intellectual gathering all over the world. The only sustainable solution to these problems is the use of solar energy and storing it as hydrogen fuel. Photocatalytic and photo-electrochemical water splitting and sacrificial hydrogen generation show a promise for future energy generation from renewable water and sunlight. This article mainly reviews the current research progress on photocatalytic and photo-electrochemical systems focusing on dye-sensitized overall water splitting and sacrificial hydrogen generation. An overview of significant parameters including dyes, sacrificial agents, modified photocatalysts and co-catalysts are provided. Also, the significance of statistical analysis as an effective tool for a systematic investigation of the effects of different factors and their interactions are explained. Finally, different photocatalytic reactor configurations that are currently in use for water splitting application in laboratory and large scale are discussed.

  7. Water quality, agriculture and food safety in China:Current situation, trends, interdependencies, and management

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-nan; GUO Qiu-ping; SHEN Xiao-xue; YU Sheng-wen; QIU Guo-yu

    2015-01-01

    Water quality in China is becoming a severe chalenge for agriculture and food safety, and it might also impact health of populationvia agriculture and food. Thus, it is causing widespread concern. Based on extensive literatures review and data mining, current situation of water polution in China and its effects on food safety were analyzed.The 2nd National Water Resource Survey in China show that the surface water al over the country was under slight polution and about 60% of groundwater is poluted. Drinking water quality is basicaly guaranteed in urban area but it is worrisome in rural areas. In addition, China is the largest consumer of fertilizer and pesticide in the world and the amounts of application stil show increasing trends. Fertilizers and pesticides are the most important sources of polution, which affect human health as persistent organic polutants and environmental endocrine disruptors. Eutrophication of surface water and nitrate polution of groundwater are serious threats to drinking water safety. Sewage irrigation is becoming a polution source to China’s water and land because of lacking of effective regulations. Although, with the advance in technology and management level, control of nitrogen and phosphorus emissions and reducing water polution is stil a major chalenge for China.

  8. Water Sensitive Urban Design: An Investigation of Current Systems, Implementation Drivers, Community Perceptions and Potential to Supplement Urban Water Services

    Directory of Open Access Journals (Sweden)

    Ashok K. Sharma

    2016-06-01

    Full Text Available Large scale centralised water, wastewater and stormwater systems have been implemented for over 100 years. These systems have provided a safe drinking water supply, efficient collection and disposal of wastewater to protect human health, and the mitigation of urban flood risk. The sustainability of current urban water systems is under pressure from a range of challenges which include: rapid population growth and resulting urbanisation, climate change impacts, and infrastructure that is ageing and reaching capacity constraints. To address these issues, urban water services are now being implemented with Integrated Urban Water Management (IUWM and Water Sensitive Urban Design (WSUD approaches. WSUD systems can deliver multiple benefits including water conservation, stormwater quality improvement, flood control, landscape amenity and a healthy living environment. These systems can be provided as stand-alone systems or in combination with centralised systems. These systems are still novel and thus face knowledge gaps that are impeding their mainstream uptake. Knowledge gaps cover technical, economic, social, and institutional aspects of their implementation. This paper is based on the outcomes of a comprehensive study conducted in South Australia which investigated impediments for mainstream uptake of WSUD, community perceptions of WSUD and potential of WSUD to achieve water conservation through the application of alternative resources, and in flood management. The outcomes are discussed in this paper for the benefit of water professionals engaged with WSUD planning, implementation, community consultation and regulation. Although the paper is based on a study conducted in South Australia, the comprehensive framework developed to conduct this detailed study and investigation can be adopted in any part of the world.

  9. Transitions for fipronil quant in surface water, Summary of Current Fipronil Water Data and Water Data for WWTPs

    Data.gov (United States)

    U.S. Environmental Protection Agency — Comparison of fipronil sources in North Carolina surface water and identification of a novel fipronil transformation product in recycled wastewater. This dataset is...

  10. Gore Creek watershed, Colorado : assessment of historical and current water quantity, water quality, and aquatic ecology, 1968-98

    Science.gov (United States)

    Wynn, Kirby H.; Bauch, Nancy J.; Driver, Nancy E.

    2001-01-01

    The historical and current (1998) water-quantity, water-quality, and aquatic-ecology conditions in the Gore Creek watershed are described as part of a study by the U.S. Geological Survey, done in cooperation with the Town of Vail, the Eagle River Water and Sanitation District, and the Upper Eagle Regional Water Authority. Interpretation of the available water-quantity, water-quality, and aquatic-ecology data collected by various agencies since 1968 showed that background geology and land use in the watershed influence the water quality and stream biota. Surface-water nutrient concentrations generally increased as water moved downstream through the Town of Vail, but concentrations at the mouth of Gore Creek were typical when compared with national data for urban/undeveloped sites. Nitrate concentrations in Gore Creek were highest just downstream from a wastewater-treatment plant discharge, but concentrations decreased at sites farther downstream because of dilution and nitrogen uptake by algae. Recent total phosphorus concentrations were somewhat elevated when compared to the U.S. Environmental Protection Agency recommended level of 0.10 milligram per liter for control of eutrophication in flowing water. However, total phosphorus concentrations at the mouth of Gore Creek were relatively low when compared to a national study of phosphorus in urban land-use areas. Historically, suspended sediment associated with construction of Interstate 70 in the early 1970's has been of primary concern; however, recent data indicate that streambed aggradation of sediment originating from Interstate 70 traction sanding currently is a greater concern. About 4,000 tons of coarse sand and fine gravel is washed into Black Gore Creek each year following application of traction materials to Interstate 70 during adverse winter driving conditions. Suspended-sediment concentrations were low in Black Gore Creek; however, bedload-transport rates of as much as 4 tons per day have been measured

  11. Wave-current interactions in deep water conditions: field measurements and analyses

    Science.gov (United States)

    Rougier, Gilles; Rey, Vincent; Molcard, Anne

    2015-04-01

    The study of wave - current interaction has drawn interest in oceanography, ocean engineering, maritime navigation and for tides or waves power device design. In the context of the hydrodynamics study along the French Mediterranean coast, a current profiler was deployed near Toulon at the south of the "Port Cros" island. This coastal zone is characterized by a steep slope, the water depth varying from tens meters to several thousand meters over few kilometers from the coast. An ambient current, the "Northern Current", coming from the Ligurian sea (area of Genoa, Italy) and following the coast up to Toulon, is present all over the year. Its mean surface velocity is of about 0.30 m/s, its flow rate of about 1.5 Sv. The region is exposed to two dominating winds: the Mistral, coming from North-West, and Eastern winds. Both generate swell and/or wind waves in either following or opposing current conditions with respect to the Northern Current. A current profiler equipped with a wave tracking system (ACPD workhorse from RDI) was deployed from July to October 2014 in deep water conditions (depth of about 500m). The mooring system allowed the ADCP to measure the current profile from the sea surface down to 25m depth, which corresponds more or less to the depth of influence of waves of periods up to 10s. The collected data include energetic wave conditions in either following or opposing current conditions. The current intensity and its vertical profiles have shown a significant temporal variability according to the meteorological conditions. Effects of the wave conditions on the current properties are discussed. ACKNOWLEDGEMENTS This work was supported by the program BOMBYX and the ANR grant No ANR-13-ASTR-0007.

  12. EFFECTS OF WATER CHEMISTRY ON COPPER TOXICITY - WHAT'S MISSING FROM CURRENT MODELS?

    Science.gov (United States)

    Current models for the acute toxicity of cationic metals to aquatic organisms focus on the binding of free metal ions to gill surfaces. This binding, and the resultant toxicity, can be reduced by metal-complexing ligands in the exposure water, which lower the activity of the free...

  13. Gravity waves on water with non-uniform depth and current

    NARCIS (Netherlands)

    Booij, N.

    1981-01-01

    A mathematical model for the combined refraction-diffraction of linear periodic gravity waves on water is developed, in which the influence of inhomogeneities of depth and current is taken into account. The model is used to compute partial reflection of waves a gully or an undersea slope, with influ

  14. 75 FR 27926 - Notice of Availability of Interpretive Rule on the Applicability of Current Water Conservation...

    Science.gov (United States)

    2010-05-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY 10 CFR Part 430 Notice of Availability of Interpretive Rule on the Applicability of Current Water Conservation... ``showerhead'' in the DOE's regulations related to the energy conservation program for consumer products....

  15. Gravity waves on water with non-uniform depth and current

    NARCIS (Netherlands)

    Booij, N.

    1981-01-01

    A mathematical model for the combined refraction-diffraction of linear periodic gravity waves on water is developed, in which the influence of inhomogeneities of depth and current is taken into account. The model is used to compute partial reflection of waves a gully or an undersea slope, with influ

  16. Deep water bottom current deposition in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    There are some active bottom currents on the northern continental slope of the South China Sea (SCS). Reflection seismic profiles show that the bottom current channels occur in the water depth range of 1000 to 2700 m,extending from the NE to the SW,leading to accumulation of discontinuous drifts with higher sedimentation rates on the eastern side of the channel. The stacking pattern of the layers sug-gests that these drifts propagated southwestward,following the direction of the bottom currents. One sedimentary drift to the southeast of the Dongsha Islands has the highest sedimentation rate of 97cm/ka in the last 12 ka. The sedimentary characteristics of the sediment layers indicate that these bottom currents are most likley caused by the water movement of a branch of the West Pacific Ocean Current,which enters the northern SCS via the Bashi Strait. Once formed,the bottom currents trans-port sediments along the northern slope of SCS southwestward and finally disappear into the central basin of the SCS. Due to the bottom current activity,the deep-sea sedimentary process in the northern SCS is complex.

  17. Conditional Short-crested second order waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2004-01-01

    For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes' wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected second order short-crested wave riding on a uniform current is given. The analysis is based on the second order Sharma and Dean shallow water wave theory and the direction...... of the main wind direction can make any direction with the current. Numerical results showing the importance of the water depth, the directional spreading and the current on the conditional mean wave profile and the associated wave kinematics are presented. A discussion of the use of the conditional wave...

  18. Loss Current Analysis of Water Tree Degradation in Polyethylene using Equivalent Circuit Model

    Science.gov (United States)

    Suzuki, Masafumi; Itoh, Atsushi; Yoshimura, Noboru

    It is well known that the degradation of XLPE cable by water tree gives rise to harmonics in the loss current. Many researches by simulation and experiment have been carried out for the purpose of the elucidation of the mechanism of the harmonics in the loss current generation. In the present study, the loss current was calculated from the equivalent circuit model composed of voltage-dependent resistance and condenser. These elements are being connected with the matrix state. As a result, we were able to obtain the good agreement between the experimental value and the calculated value by appropriately choosing the characteristics of the voltage-dependent resistance. The equivalent circuit model determined in this study can consider not only the electrical characteristic of water tree but also its shape.

  19. Offshore produced water management: A review of current practice and challenges in harsh/Arctic environments.

    Science.gov (United States)

    Zheng, Jisi; Chen, Bing; Thanyamanta, Worakanok; Hawboldt, Kelly; Zhang, Baiyu; Liu, Bo

    2016-03-15

    Increasing offshore oil and gas exploration and development in harsh/Arctic environments require more effective offshore produced water management, as these environments are much more sensitive to changes in water quality than more temperate climates. However, the number and scope of studies of offshore produced water management in harsh/Arctic environments are limited. This paper reviews the current state of offshore produced water management, impacts, and policies, as well as the vulnerability, implications and operational challenges in harsh/Arctic environments. The findings show that the primary contaminant(s) of concern are contained in both the dissolved oil and the dispersed oil. The application of emerging technologies that can tackle this issue is significantly limited by the challenges of offshore operations in harsh/Arctic environments. Therefore, there is a need to develop more efficient and suitable management systems since more stringent policies are being implemented due to the increased vulnerability of harsh/Arctic environments.

  20. Effects of alternating and direct current in electrocoagulation process on the removal of cadmium from water

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Subramanyan, E-mail: vasudevan65@gmail.com [CSIR-Central Electrochemical Research Institute, Karaikudi 630 006 (India); Lakshmi, Jothinathan; Sozhan, Ganapathy [CSIR-Central Electrochemical Research Institute, Karaikudi 630 006 (India)

    2011-08-15

    Highlights: {yields} Very high removal efficiency of cadmium was achieved by electrocoagulation. {yields} Alternating current (AC) avoids oxide layer and corrosion on anode surface. {yields} Good current transfer between anode and cathode results more removal efficiency. {yields} Compact treatment facility and complete automation. {yields} Aluminum alloy anode prevents residual aluminum in treated water. - Abstract: In practice, direct current (DC) is used in an electrocoagulation processes. In this case, an impermeable oxide layer may form on the cathode as well as corrosion formation on the anode due to oxidation. This prevents the effective current transfer between the anode and cathode, so the efficiency of electrocoagulation processes declines. These disadvantages of DC have been diminished by adopting alternating current (AC) in electrocoagulation processes. The main objective of this study is to investigate the effects of AC and DC on the removal of cadmium from water using aluminum alloy as anode and cathode. The results showed that the removal efficiency of 97.5 and 96.2% with the energy consumption of 0.454 and 1.002 kWh kl{sup -1} was achieved at a current density of 0.2 A/dm{sup 2} and pH of 7.0 using aluminum alloy as electrodes using AC and DC, respectively. For both AC and DC, the adsorption of cadmium was preferably fitting Langmuir adsorption isotherm, the adsorption process follows second order kinetics and the temperature studies showed that adsorption was exothermic and spontaneous in nature.

  1. Seasonal to interannual variability of water mass characteristics and currents on the Namibian shelf

    Science.gov (United States)

    Junker, Tim; Mohrholz, Volker; Siegfried, Lydia; van der Plas, Anja

    2017-01-01

    We present long-term current meter records from the Benguela system together with salinity and temperature observations gathered by a mooring on the Namibian shelf across 13 years (2002-2015). From this unique data set a climatological mean state is estimated enabling us to investigate seasonal to interannual variations of these variables on the Namibian shelf. The present study highlights the importance of the alongshore advection for the water mass characteristics in the Benguela system on a seasonal time scale. The annual cycle of the alongshore transport is characterized by a biannual flow reversal. Poleward directed currents dominate from October to April, and from May to September equatorward currents prevail. In addition, we present observational evidence for a biannual intrusion of tropical waters into the Benguela system with maxima in October and February. Based on the in situ temperature data, several anomalous events are described that affect the whole water column. During the outstanding warm event in austral fall 2011 the monthly temperature anomaly exceeds one Kelvin for five consecutive months peaking in March (2.4 K) in the upper layer of the water column. Our study suggests, that the occurrence of such extreme temperature events in the Benguela upwelling system is closely related to the strength of the alongshore advection in austral summer.

  2. Ecological relevance of current water quality assessment unit designations in impaired rivers

    Science.gov (United States)

    Layhee, Megan J.; Sepulveda, Adam; Ray, Andrew; Mladenka, Greg; Van Every, Lynn

    2016-01-01

    Managers often nest sections of water bodies together into assessment units (AUs) to monitor and assess water quality criteria. Ideally, AUs represent an extent of waters with similar ecological, watershed, habitat and land-use conditions and no overlapping characteristics with other waters. In the United States, AUs are typically based on political or hydrologic boundaries rather than on ecologically relevant features, so it can be difficult to detect changes in impairment status. Our goals were to evaluate if current AU designation criteria of an impaired water body in southeastern Idaho, USA that, like many U.S. waters, has three-quarters of its mainstem length divided into two AUs. We focused our evaluation in southeastern Idaho's Portneuf River, an impaired river and three-quarters of the river is divided into two AUs. We described biological and environmental conditions at multiple reaches within each AU. We used these data to (1) test if variability at the reach-scale is greater within or among AUs and, (2) to evaluate alternate AU boundaries based on multivariate analyses of reach-scale data. We found that some biological conditions had greater variability within an AU than between AUs. Multivariate analyses identified alternative, 2- and 3-group, AUs that reduced this variability. Our results suggest that the current AU designations in the mainstem Portneuf River contain ecologically distinct sections of river and that the existing AU boundaries should be reconsidered in light of the ecological conditions measured at the reach scale. Variation in biological integrity within designated AUs may complicate water quality and biological assessments, influence management decisions or affect where monitoring or mitigation resources are directed.

  3. The establishment of Atlantic Water transport as a topographically trapped slope current off Scotland

    Directory of Open Access Journals (Sweden)

    Qin Zhou

    2013-05-01

    Full Text Available Atlantic Water, with its origin in the western Atlantic, enters the Nordic Seas partly as a barotropic current following the continental slope. This water mass is carried across the Atlantic by the baroclinic North Atlantic Current (NAC. When the NAC meets the continental slope at the east side of the Atlantic, some of the transport is converted to barotropic transport over the slope before continuing northward. Here, we show that this baroclinic to barotropic conversion is in agreement with geostrophic theory. Historical observations show that the transport of the slope current increases significantly from the Rockall Channel (RC to the Faroe–Shetland Channel (FSC. Geostrophy predicts that with a northward decreasing buoyancy, baroclinic currents from the west will be transferred into northward topographically steered barotropic flow. We use hydrographic data from two sections crossing the continental slope, one located in the RC and another in the FSC, to estimate baroclinic and barotropic transport changes over the slope, within the framework of geostrophic dynamics. Our results indicate that ~1 Sv of the cross-slope baroclinic flow is mainly converted to northward barotropic transport above the 200–500m isobaths, which is consistent with observed transport changes between the RC and the FSC. Similar processes are also likely to occur further south, along the eastern Atlantic margin. This shows that AW within the slope current in the FSC is derived from both the eastern and the western Atlantic, in agreement with earlier studies of AW inflow to the Nordic Seas.

  4. The representation of boundary currents in a finite element shallow water model

    CERN Document Server

    Düben, Peter D

    2015-01-01

    We evaluate the influence of local resolution, eddy viscosity, coastline structure, and boundary conditions on the numerical representation of boundary currents in a finite element shallow-water model. The use of finite element discretization methods offers a higher flexibility compared to finite difference and finite volume methods, that are mainly used in previous publications. This is true for the geometry of the coast lines and for the realization of boundary conditions. For our investigations we simulate steady separation of western boundary currents from idealized and realistic coast lines. The use of grid refinement allows a detailed investigation of boundary separation at reasonable numerical cost.

  5. Measurement of the muon-neutrino charged-current cross section on water with zero pions

    CERN Document Server

    Yuan, Tianlu

    2016-01-01

    The Tokai to Kamioka (T2K) experiment is a 295-km long-baseline neutrino experiment aimed towards the measurement of neutrino oscillation parameters ${\\theta}_{13}$ and ${\\theta}_{23}$. Precise measurement of these parameters requires accurate knowledge of neutrino cross sections. We present a flux-averaged double differential measurement of the charged-current cross section on water with zero pions in the final state using the T2K off-axis near detector, ND280. A selection of $\

  6. Application of hydrographic and surface current data to describe water properties in the Porsangerfjorden, Norway

    Science.gov (United States)

    Cieszyńska, Agata; Białogrodzka, Jagoda; Yngve Børsheim, Knut; Stramska, Małgorzata; Jankowski, Andrzej

    2016-04-01

    This presentation is a part of the NORDFLUX project, and describes some of the results from experimental work carried out in 2014 in the Porsangerfjorden located in the area of the European Arctic. The fjord borders the Barents Sea. This is a region of high climatic sensitivity and our interest in the basin stemmed from this fact. One of our long-term goals is to develop an improved understanding of the undergoing changes and interactions between this fjord and the large-scale atmospheric and oceanic conditions. In present work we focus on data sets collected with High Frequency (HF) radars monitoring surface currents in the outer part of the Porsnagerfjorden. In our analysis we also use data on water salinity and temperature collected as part of the NORDFLUX experiment, and data from sea level and meteorological station located in Honningsvaag. Analysis of data sets enabled us to describe water salinity, temperature, density distributions and their variability. What is more, we have related aforementioned results to tides, meteorological conditions, and sea surface currents speed and directions. During the poster session the Author will present the schemes of water masses movement in the area of interest. This work was funded by the Norway Grants through the Polish-Norwegian Research Programme, National Centre for Research and Development (contract No. 201985). Project title: 'Application of in situ observations, high frequency radars, and ocean color, to study suspended matter, particulate carbon, and dissolved organic carbon fluxes in coastal waters of the Barents Sea'.

  7. Seasonal Variation in Sea Turtle Density and Abundance in the Southeast Florida Current and Surrounding Waters.

    Science.gov (United States)

    Bovery, Caitlin M; Wyneken, Jeanette

    2015-01-01

    Assessment and management of sea turtle populations is often limited by a lack of available data pertaining to at-sea distributions at appropriate spatial and temporal resolutions. Assessing the spatial and temporal distributions of marine turtles in an open system poses both observational and analytical challenges due to the turtles' highly migratory nature. Surface counts of marine turtles in waters along the southern part of Florida's east coast were made in and adjacent to the southeast portion of the Florida Current using standard aerial surveys during 2011 and 2012 to assess their seasonal presence. This area is of particular concern for sea turtles as interest increases in offshore energy developments, specifically harnessing the power of the Florida Current. While it is understood that marine turtles use these waters, here we evaluate seasonal variation in sea turtle abundance and density over two years. Density of sea turtles observed within the study area ranged from 0.003 turtles km-2 in the winter of 2011 to 0.064 turtles km-2 in the spring of 2012. This assessment of marine turtles in the waters off southeast Florida quantifies their in-water abundance across seasons in this area to establish baselines and inform future management strategies of these protected species.

  8. Seasonal Variation in Sea Turtle Density and Abundance in the Southeast Florida Current and Surrounding Waters

    Science.gov (United States)

    Bovery, Caitlin M.; Wyneken, Jeanette

    2015-01-01

    Assessment and management of sea turtle populations is often limited by a lack of available data pertaining to at-sea distributions at appropriate spatial and temporal resolutions. Assessing the spatial and temporal distributions of marine turtles in an open system poses both observational and analytical challenges due to the turtles’ highly migratory nature. Surface counts of marine turtles in waters along the southern part of Florida’s east coast were made in and adjacent to the southeast portion of the Florida Current using standard aerial surveys during 2011 and 2012 to assess their seasonal presence. This area is of particular concern for sea turtles as interest increases in offshore energy developments, specifically harnessing the power of the Florida Current. While it is understood that marine turtles use these waters, here we evaluate seasonal variation in sea turtle abundance and density over two years. Density of sea turtles observed within the study area ranged from 0.003 turtles km-2 in the winter of 2011 to 0.064 turtles km-2 in the spring of 2012. This assessment of marine turtles in the waters off southeast Florida quantifies their in-water abundance across seasons in this area to establish baselines and inform future management strategies of these protected species. PMID:26717520

  9. Variable influx of West Greenland Current water into the Labrador Current through the last 8000 years, based on a multiproxy study from Trinity Bay, NE Newfoundland

    DEFF Research Database (Denmark)

    Sheldon, Christina; Seidenkrantz, Marit-Solveig; Frandsen, Paul

    2015-01-01

    . This may be explained by a weaker North Atlantic subpolar gyre, transporting less Atlantic Water from the WGC to the (outer) LC. Arctic meltwater transport was reduced as glacial melting decreased at the end of the Holocene Thermal Optimum. At ca. 3 cal kyr BP, bottom waters returned to colder, more stable...... Current (WGC) Davis Strait branch, merging into the relatively cold LC. This Atlantic water influence gradually decreased after ca. 6 cal kyr BP, reaching a minimum at 5 cal kyr BP. In contrast, surface temperatures were relatively low due to cold surface water dominated by sea ice and meltwater carried...... conditions, indicating a slight decrease in bottom-water ventilation. After ca. 2.2 cal kyr BP surface water temperatures dropped and sea ice flux increased. The seafloor of Trinity Bay saw warmer conditions, consistent with a stronger subpolar gyre and increased influx of Atlantic-sourced water....

  10. An empirical model for salt removal percentage in water under the effect of different current intensities of current carrying coil at different flow rates

    Directory of Open Access Journals (Sweden)

    Rameen S. AbdelHady

    2011-10-01

    Full Text Available The magnetic treatment of hard water is an alternative, simple approach by which the hard water that needs to be treated flows through a magnetic field. This field is created by inducing current in a coil wrapped around a pipe. Consequently some of its properties, such as total dissolved salts (TDS, conductivity (Ec and PH change. The primary purpose of hard water treatment is to decrease TDS in the incoming liquid stream. Using performance data from the application of different magnetic field densities on the different flow levels of water, empirical mathematical models were developed relating the salt removal percentage (SRP to operating flow rate and current of the coil. The obtained experimental results showed that the SRP increased with increasing the current at low flow rates (up to 0.75 ml/s.

  11. A review of current and possible future human-water dynamics in Myanmar's river basins

    Science.gov (United States)

    Taft, Linda; Evers, Mariele

    2016-12-01

    Rivers provide a large number of ecosystem services and riparian people depend directly and indirectly on water availability and quality and quantity of the river waters. The country's economy and the people's well-being and income, particularly in agriculturally dominated countries, are strongly determined by the availability of sufficient water. This is particularly true for the country of Myanmar in South-east Asia, where more than 65 % of the population live in rural areas, working in the agricultural sector. Only a few studies exist on river basins in Myanmar at all and detailed knowledge providing the basis for human-water research is very limited. A deeper understanding of human-water system dynamics in the country is required because Myanmar's society, economy, ecosystems and water resources are facing major challenges due to political and economic reforms and massive and rapid investments from neighbouring countries. However, not only policy and economy modify the need for water. Climate variability and change are other essential drivers within human-water systems. Myanmar's climate is influenced by the Indian Monsoon circulation which is subject to interannual and also regional variability. Particularly the central dry zone and the Ayeyarwady delta are prone to extreme events such as serious drought periods and extreme floods. On the one hand, the farmers depend on the natural fertiliser brought by regular river inundations and high groundwater levels for irrigation; on the other hand, they suffer from these water-related extreme events. It is expected that theses climatic extreme events will likely increase in frequency and magnitude in the future as a result of global climate change. Different national and international interests in the abundant water resources may provide opportunities and risks at the same time for Myanmar. Several dam projects along the main courses of the rivers are currently in the planning phase. Dams will most likely modify the

  12. Nuclear Quantum Effects in Water and Aqueous Systems: Experiment, Theory, and Current Challenges.

    Science.gov (United States)

    Ceriotti, Michele; Fang, Wei; Kusalik, Peter G; McKenzie, Ross H; Michaelides, Angelos; Morales, Miguel A; Markland, Thomas E

    2016-07-13

    Nuclear quantum effects influence the structure and dynamics of hydrogen-bonded systems, such as water, which impacts their observed properties with widely varying magnitudes. This review highlights the recent significant developments in the experiment, theory, and simulation of nuclear quantum effects in water. Novel experimental techniques, such as deep inelastic neutron scattering, now provide a detailed view of the role of nuclear quantum effects in water's properties. These have been combined with theoretical developments such as the introduction of the principle of competing quantum effects that allows the subtle interplay of water's quantum effects and their manifestation in experimental observables to be explained. We discuss how this principle has recently been used to explain the apparent dichotomy in water's isotope effects, which can range from very large to almost nonexistent depending on the property and conditions. We then review the latest major developments in simulation algorithms and theory that have enabled the efficient inclusion of nuclear quantum effects in molecular simulations, permitting their combination with on-the-fly evaluation of the potential energy surface using electronic structure theory. Finally, we identify current challenges and future opportunities in this area of research.

  13. Analysis of projected water availability with current basin management plan, Pajaro Valley, California

    Science.gov (United States)

    Hanson, R. T.; Lockwood, B.; Schmid, Wolfgang

    2014-11-01

    The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within “water-balance subregions” (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori. The analysis of projected supply and demand for the Pajaro Valley indicate that the current water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations

  14. Thermal infrared remote sensing for riverscape analysis of water temperature heterogeneity: current research and future directions

    Science.gov (United States)

    Dugdale, S.; Hannah, D. M.; Malcolm, I.; Bergeron, N.; St-Hilaire, A.

    2016-12-01

    Climate change will increase summer water temperatures in northern latitude rivers. It is likely that this will have a negative impact on fish species such as salmonids, which are sensitive to elevated temperatures. Salmonids currently avoid heat stress by opportunistically using cool water zones that arise from the spatio-temporal mosaic of thermal habitats present within rivers. However, there is a general lack of information about the processes driving this thermal habitat heterogeneity or how these spatio-temporal patterns might vary under climate change. In this paper, we document how thermal infrared imaging has previously been used to better understand the processes driving river temperature patterns. We then identify key knowledge gaps that this technology can help to address in the future. First, we demonstrate how repeat thermal imagery has revealed the role of short-term hydrometeorological variability in influencing longitudinal river temperature patterns, showing that precipitation depth is strongly correlated with the degree of longitudinal temperature heterogeneity. Second, we document how thermal infrared imagery of a large watershed in Eastern Canada has shed new light on the landscape processes driving the spatial distribution of cool water patches, revealing that the distribution of cool patches is strongly linked to channel confinement, channel curvature and the proximity of dry tributary valleys. Finally, we detail gaps in current understanding of spatio-temporal patterns of river temperature heterogeneity. We explain how advances in unmanned aerial vehicle technology and deterministic temperature modelling will be combined to address these current limitations, shedding new light on the landscape processes driving geographical variability in patterns of river temperature heterogeneity. We then detail how such advances will help to identify rivers that will be resilient to future climatic warming, improving current and future strategies for

  15. Recent hydrographic measurements in the Lake Issyk Kul: Coastal currents, thermohaline structure, water quality indicators

    Science.gov (United States)

    Zavialov, Peter; Osadchiev, Alexander; Pelevin, Vadim; Konovalov, Boris; Goncharenko, Igor

    2015-04-01

    Issyk Kul is a deep (670 m) terminal lake in the northern Tian Shan mountains in eastern Kyrgyzstan. It is the tenth largest lake in the world by volume, and the second largest saline lake after the Caspian Sea. The lake is a Ramsar site of globally significant biodiversity. We report preliminary results of a field survey undertaken in the northern coastal part of the lake, off Cholpon-Ata township, on September 10-13, 2014. A fishery boat was used to carry out CTD profiling and water sampling at 16 stations. An UV fluorescent lidar working continuosly throughout the survey yielded surface concentrations of chlorophyll-a, suspended matter, and dissolved organic substances. In addition, we deployed 3 mooring stations equipped with current meters, all at approximately 15 m isobath, recording the velocity and direction of the near-bottom currents with 10 min sampling intervals. During the experiment, the coastal waters of the lake were fully mixed down to the depth of 15-20 m and nearly uniform vertically at salinity about 5 g/kg. The only exception referred to the areas adjacent to the mouths of small river and creeks, where stable salinity stratification developed at 0.01-0.03 g/kg per 1 m of depth. The temperature stratification generally followed the diurnal pattern. The dominant coastal currents were directed westward, which agrees with the established notion about the cyclonic character of the basin-scale circulation. Superimposed on this general cyclonic pattern, there was a persistent variability of currents at the periods of 17 to 24 hours, likely associated with the interplay between the inertial oscillation and signal of breeze in the wind forcing. There was an evidence of mesoscale eddies, possibly, associated with topographic features of the shoreline. The observed velocity in the near-bottom layer was about 9 cm/s on the average, with the maximum values exceeding 25 cm/s. The Issyk Kul lake is ultra-oligotrophic - the concentrations of chlorophyll-a were

  16. Secondary current properties generated by wind-induced water waves in experimental conditions

    Directory of Open Access Journals (Sweden)

    Michio Sanjou

    2014-06-01

    Full Text Available Secondary currents such as the Langmuir circulation are of high interest in natural rivers and the ocean because they have striking impacts on scour, sedimentation, and mass transport. Basic characteristics have been well-studied in straight open-channel flows. However, little is known regarding secondary circulation induced by wind waves. The presented study describes the generation properties of wind waves observed in the laboratory tank. Wind-induced water waves are known to produce large scale circulations. The phenomenon is observed together with high-speed and low-speed streaks, convergence and divergence zones, respectively. Therefore, it is important to determine the hydrodynamic properties of secondary currents for wind-induced water waves within rivers and lakes. In this study, using two high-speed CMOS cameras, stereoscopic particle image velocimetry (PIV measurements were conducted in order to reveal the distribution of all three components of velocity vectors. The experiments allowed us to investigate the three-dimensional turbulent structure under water waves and the generation mechanism of large-scale circulations. Additionally, a third CMOS camera was used to measure the spanwise profile of thefree-surface elevation. The time-series of velocity components and the free-surface were obtained simultaneously. From our experiments, free-surface variations were found to influence the instantaneous velocity distributions of the cross-sectional plane. We also considered thegeneration process by the phase analysis related to gravity waves and compared the contribution of the apparent stress.

  17. A study of diffuser angle effect on ducted water current turbine performance using CFD

    Directory of Open Access Journals (Sweden)

    Adun Janyalertadun

    2012-02-01

    Full Text Available The water current has used as the energy resource for long time however its velocity is very low therefore there arenot found in wide range of uses. This study purposes accelerate water velocity by installing diffuser. The problems wereanalyzed by one dimension analysis and computational fluid dynamics (CFD; the domain covers the diffuser and turbinewhich substituted by porous jump condition is install inside. The flow was identified as axisymmetric steady flow, the inletboundary is identified as uniform flow, all simulation use the same size of diffuser, only the diffuser angles are vary. The resultsshow that velocities of water current in diffuser are increase when the diffuser angle are widen. The angle of diffuser is 20°,the velocity is increase to 1.96 times, compared to free stream velocity. If the angle was about 0-20° and 50-70° the forcetoward diffuser became high instantly; where as the force toward the rotor will be still and the maximum rate of diffuseraugmentation possibly was 3.62 and rotor power coefficient was 2.14.

  18. Currents and convection cause enhanced gas exchange in the ice–water boundary layer

    Directory of Open Access Journals (Sweden)

    Brice Loose

    2016-12-01

    Full Text Available The presence of sea ice acts as a physical barrier for air–sea exchange. On the other hand it creates additional turbulence due to current shear and convection during ice formation. We present results from a laboratory study that demonstrate how shear and convection in the ice–ocean boundary layer can lead to significant gas exchange. In the absence of wind, water currents beneath the ice of 0.23 m s−1 produced a gas transfer velocity (k of 2.8 m d−1, equivalent to k produced by a wind speed of 7 m s−1 over the open ocean. Convection caused by air–sea heat exchange also increased k of as much as 131 % compared to k produced by current shear alone. When wind and currents were combined, k increased, up to 7.6 m d−1, greater than k produced by wind or currents alone, but gas exchange forcing by wind produced mixed results in these experiments. As an aggregate, these experiments indicate that using a wind speed parametrisation to estimate k in the sea ice zone may underestimate k by ca. 50 % for wind speeds <8 m s−1.

  19. Rapid determination of phenolic compounds in water samples by alternating-current oscillopolarographic titration

    Institute of Scientific and Technical Information of China (English)

    XIAO Jun-ping; WANG Xue-feng; ZHOU Qing-xiang; FAN Xiao-yuan; SU Xian-fa; Bai Hua-hua; DUAN Hai-jing

    2007-01-01

    A rapid, simple and sensitive method was demonstrated for the determination of phenolic compounds in water samples by alternating-current oscillopolarographic titration. With the presence of sulfuric acid, phenol could be transferred into a nitroso-compound by reacting with NaNO2. The titration end-point was obtained by the formation of a sharp cut in the oscillopolarographic with infinitesimal NaNO2 on double platinum electrodes. The results showed that phenol had an excellent linear relationship over the range of 4.82×10-6 -9.65×10-3 mol/L, the RSD of the proposed method was lower than 1.5%, and the spiked recoveries of three real water samples were in the range of 95.6%-106.9%.

  20. Conditional short-crested waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2002-01-01

    For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes´ wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected linear short-crested wave riding on a uniform current is given. The analysis is based on the conventional shallow water Airy wave theory and the direction of the main wind...

  1. Stability of steady rotational water-waves of finite amplitude on arbitrary shear currents

    Science.gov (United States)

    Seez, William; Abid, Malek; Kharif, Christian

    2016-04-01

    A versatile solver for the two-dimensional Euler equations with an unknown free-surface has been developed. This code offers the possibility to calculate two-dimensional, steady rotational water-waves of finite amplitude on an arbitrary shear current. Written in PYTHON the code incorporates both pseudo-spectral and finite-difference methods in the discretisation of the equations and thus allows the user to capture waves with large steepnesses. As such it has been possible to establish that, in a counter-flowing situation, the existence of wave solutions is not guaranteed and depends on a pair of parameters representing mass flux and vorticity. This result was predicted, for linear solutions, by Constantin. Furthermore, experimental comparisons, both with and without vorticity, have proven the precision of this code. Finally, waves propagating on top of highly realistic shear currents (exponential profiles under the surface) have been calculated following current profiles such as those used by Nwogu. In addition, a stability analysis routine has been developed to study the stability regimes of base waves calculated with the two-dimensional code. This linear stability analysis is based on three dimensional perturbations of the steady situation which lead to a generalised eigenvalue problem. Common instabilities of the first and second class have been detected, while a third class of wave-instability appears due to the presence of strong vorticity. {1} Adrian Constantin and Walter Strauss. {Exact steady periodic water waves with vorticity}. Communications on Pure and Applied Mathematics, 57(4):481-527, April 2004. Okey G. Nwogu. {Interaction of finite-amplitude waves with vertically sheared current fields}. Journal of Fluid Mechanics, 627:179, May 2009.

  2. Water-waves on linear shear currents. A comparison of experimental and numerical results.

    Science.gov (United States)

    Simon, Bruno; Seez, William; Touboul, Julien; Rey, Vincent; Abid, Malek; Kharif, Christian

    2016-04-01

    Propagation of water waves can be described for uniformly sheared current conditions. Indeed, some mathematical simplifications remain applicable in the study of waves whether there is no current or a linearly sheared current. However, the widespread use of mathematical wave theories including shear has rarely been backed by experimental studies of such flows. New experimental and numerical methods were both recently developed to study wave current interactions for constant vorticity. On one hand, the numerical code can simulate, in two dimensions, arbitrary non-linear waves. On the other hand, the experimental methods can be used to generate waves with various shear conditions. Taking advantage of the simplicity of the experimental protocol and versatility of the numerical code, comparisons between experimental and numerical data are discussed and compared with linear theory for validation of the methods. ACKNOWLEDGEMENTS The DGA (Direction Générale de l'Armement, France) is acknowledged for its financial support through the ANR grant N° ANR-13-ASTR-0007.

  3. Adaptive capacity indicators to assess sustainability of urban water systems - Current application.

    Science.gov (United States)

    Spiller, Marc

    2016-11-01

    Sustainability is commonly assessed along environmental, societal, economic and technological dimensions. A crucial aspect of sustainability is that inter-generational equality must be ensured. This requires that sustainability is attained in the here and now as well as into the future. Therefore, what is perceived as 'sustainable' changes as a function of societal opinion and technological and scientific progress. A concept that describes the ability of systems to change is adaptive capacity. Literature suggests that the ability of systems to adapt is an integral part of sustainable development. This paper demonstrates that indicators measuring adaptive capacity are underrepresented in current urban water sustainability studies. Furthermore, it is discussed under which sustainability dimensions adaptive capacity indicators are lacking and why. Of the >90 indicators analysed, only nine are adaptive capacity indicators, of which six are socio-cultural, two technological, one economical and none environmental. This infrequent use of adaptive capacity indicators in sustainability assessments led to the conclusion that the challenge of dynamic and uncertain urban water systems is, with the exception of the socio-cultural dimension, not yet sufficiently reflected in the application of urban water sustainability indicators. This raises concerns about the progress towards urban water systems that can transform as a response variation and change. Therefore, research should focus on developing methods and indicators that can define, evaluate and quantify adaptive capacity under the economic, environmental and technical dimension of sustainability. Furthermore, it should be evaluated whether sustainability frameworks that focus on the control processes of urban water systems are more suitable for measuring adaptive capacity, than the assessments along environmental, economic, socio-cultural and technological dimensions. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Assessing the ability of current climate information to facilitate local climate services for the water sector.

    Science.gov (United States)

    Koutroulis, Aristeidis; Tsanis, Ioannis; Grillakis, Manolis; Jacob, Daniela

    2014-05-01

    In the frame of ECLISE EU FP6 project researchers, in close cooperation with local users of the water sector from the area of Crete, Greece, explored the ability of current climate information to develop and support local climate services water resources management and climate adaption policies. A wealth of climate modeling output ranging from event scale to decadal and centennial experiments, at temporal scales ranging from hourly to monthly, and at spatial scales from very high resolution regional climate models (2 km) to typical GCMs, were used in order to practically assess climate change impacts on water resources. Water resources availability issues analysed and facilitated within the project, focusing on estimates of the future water demands of the island, and comparing with seven "state of the art" CMIP5 simulations within COMBINE framework (under RCPs 2.6, 4.5 and 8.5) to estimate water resources availability, during 21st century. The ability of decadal GCM prediction experiments to reproduce basic hydrometeorological variables like precipitation and temperature for local impact studies, was also examined. Water availability for the whole island at basin scale until 2100 is estimated using the SAC-SMA rainfall-runoff model for a range of different scenarios of projected hydro-climatological regime, demand and supply potential. A robust signal of temperature increase and precipitation decrease is projected for all the pathways. Several messages could be extracted from this provider - user interaction such as the communication of basic concepts and uncertainties, user skepticism and feedback. The main user concern was the coarse spatial scale of climate information and in order to cope with this feedback a special case was framed in collaboration with the project modeling groups for demonstrating a high resolution climate modeling application of an extreme precipitation-flood event over the study area. This effort provided a realistic reproduction of the

  5. Analysis of heavy particle processes in low current dc discharge in water vapor

    Science.gov (United States)

    Sivos, Jelena; Maric, Dragana; Skoro, Nikola; Malovic, Gordana; Petrovic, Zoran Lj

    2016-09-01

    Results presented in our recent paper show that heavy particles - positive ions and fast neutrals (created in charge transfer processes) - can have significant contribution to the processes of excitation at moderate and high reduced electric fields (E / N) . In the case of water vapor, hydrogen ions and fast atoms are the most probable candidates, as the lightest products in water vapor discharges. In order to identify dominant heavy species in water vapor discharge, we analyzed discharge parameters in low current Townsend regime. Based on the model developed by Phelps and coworkers in 1993. we were able to estimate transit time of ions from experimentally determined frequency of damped oscillations and parameters of electrical circuit. Furthermore, we compared calculated transit times with transit times of hydrogen ions (H+, H2+,H3+).Initial analysis indicates that H2+is dominant ion in the range of moderate E / N ( 2 kTd). Calculations were done for the discharge initiated at electrode gap of 1.1 cm and pressure (p) x gap (d) of 0.6 Torrcm, which corresponds to the conditions of the minimum of Paschen curve. In the next step we will extend the analysis to wider range operating conditions. This work is supported by the Serbian MESTD under project numbers ON 171037 and III 41011.

  6. Current direction/velocity and other data from current meter casts in Coastal Waters of Hawaii from 1991-09-30 to 1996-04-26 (NODC Accession 9700214)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction/velocity, wind direction/velocity, and water temperature data were collected using current meter in the Coastal Waters of Hawaii from September...

  7. Water Resource Impacts Embedded in the Western US Electrical Energy Trade; Current Patterns and Adaptation to Future Drought

    Science.gov (United States)

    Adams, E. A.; Herron, S.; Qiu, Y.; Tidwell, V. C.; Ruddell, B. L.

    2013-12-01

    Water resources are a key element in the global coupled natural-human (CNH) system, because they are tightly coupled with the world's social, environmental, and economic subsystems, and because water resources are under increasing pressure worldwide. A fundamental adaptive tool used especially by cities to overcome local water resource scarcity is the outsourcing of water resource impacts through substitutionary economic trade. This is generally understood as the indirect component of a water footprint, and as ';virtual water' trade. This work employs generalized CNH methods to reveal the trade in water resource impacts embedded in electrical energy within the Western US power grid, and utilizes a general equilibrium economic trade model combined with drought and demand growth constraints to estimate the future status of this trade. Trade in embedded water resource impacts currently increases total water used for electricity production in the Western US and shifts water use to more water-limited States. Extreme drought and large increases in electrical energy demand increase the need for embedded water resource impact trade, while motivating a shift to more water-efficient generation technologies and more water-abundant generating locations. Cities are the largest users of electrical energy, and in the 21st Century will outsource a larger fraction of their water resource impacts through trade. This trade exposes cities to risks associated with disruption of long-distance transmission and distant hydrological droughts.

  8. Physical characteristics of the coastal waters between Navapur and Umbharat, West coast of India. Part 1. Current pattern

    Digital Repository Service at National Institute of Oceanography (India)

    Swamy, G.N.; Sarma, R.V.; Suryanarayana, A.

    Surface and bottom current patterns of the coastal waters between Navapur and Umbharat (Maharashtra-Gujarat Industrial Belt) are described in relation to tides and other environmental parameters. The results of the analysis of the frequency...

  9. Review of current interest and research in water hyacinth-based wastewater treatment

    Science.gov (United States)

    Markarian, R. K.; Balon, J. E.; Robinson, A. C.

    1977-01-01

    The status of activity in the user community for water hyacinth-based wastewater treatment was evaluated. The principal technique used was that of interviewing people who either (1) were known to be engaged in hyacinth research or development or (2) had made inquiry to NASA about hyacinth systems. About 40 non-research organizations and a similar number of research organizations were contacted. As a result of the interviews and a review of the relevant literature, it was concluded that hyacinth systems have the potential for providing a lower cost way for small cities to meet increasingly stringent effluent requirements. A limited amount of full-scale demonstration of hyacinth systems has been carried out during the past two years, but the yield of design data has been small. Several organizations are currently planning construction of experimental full-scale hyacinth-based wastewater treatment systems during 1977-1978.

  10. Effects of Topography and Current on Horizontal Irrotational Waves in Shallow Water

    Institute of Scientific and Technical Information of China (English)

    孙明光; 高虎山

    2000-01-01

    Based on the Boussinesq assumption, derived are couple equations of free surface elevation and horizontal velocities for horizontal irrotational flow, and analytical expressions of the corresponding pressure and vertical velocity. After the free surface elevation and horizontal velocity at a certain depth are obtained by numerical method, the pressure and vertical velocity distributions can be obtained by simple calculation. The dispersion at different depths is the same at the O (ε) approximation. The wave amplitude will decrease with increasing time due to viscosity, but it will increase due to the matching of viscosity and the bed slope, thus. flow is unstable. Numerical or analytical results show that the wave amplitude, velocity and length will increase as the current increases along the wave direction, but the amplitude will increase, and the wave velocity and length will decrease as the water depth decreases.

  11. Categorization of failed and damaged spent LWR (light-water reactor) fuel currently in storage

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, W.J.

    1987-11-01

    The results of a study that was jointly sponsored by the US Department of Energy and the Electric Power Research Institute are described in this report. The purpose of the study was to (1) estimate the number of failed fuel assemblies and damaged fuel assemblies (i.e., ones that have sustained mechanical or chemical damage but with fuel rod cladding that is not breached) in storage, (2) categorize those fuel assemblies, and (3) prepare this report as an authoritative, illustrated source of information on such fuel. Among the more than 45,975 spent light-water reactor fuel assemblies currently in storage in the United States, it appears that there are nearly 5000 failed or damaged fuel assemblies. 78 refs., 23 figs., 19 tabs.

  12. Conditional Short-crested second order waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2004-01-01

    wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected second order short-crested wave riding on a uniform current is given. The analysis is based on the second order Sharma and Dean shallow water wave theory and the direction......For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes' wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... waves is poorly represented, as the shape of the wave spectrum does not enter the wave kinematics. To overcome this problem and still keep the simplicity of a deterministic approach, Tromans, Anaturk and Hagemeijer (1991) suggested the use of a deterministic wave, defined as the expected linear Airy...

  13. Response of stream benthic macroinvertebrates to current water management in Alpine catchments massively developed for hydropower.

    Science.gov (United States)

    Quadroni, Silvia; Crosa, Giuseppe; Gentili, Gaetano; Espa, Paolo

    2017-12-31

    The present work focuses on evaluating the ecological effects of hydropower-induced streamflow alteration within four catchments in the central Italian Alps. Downstream from the water diversions, minimum flows are released as an environmental protection measure, ranging approximately from 5 to 10% of the mean annual natural flow estimated at the intake section. Benthic macroinvertebrates as well as daily averaged streamflow were monitored for five years at twenty regulated stream reaches, and possible relationships between benthos-based stream quality metrics and environmental variables were investigated. Despite the non-negligible inter-site differences in basic streamflow metrics, benthic macroinvertebrate communities were generally dominated by few highly resilient taxa. The highest level of diversity was detected at sites where upstream minimum flow exceedance is higher and further anthropogenic pressures (other than hydropower) are lower. However, according to the current Italian normative index, the ecological quality was good/high on average at all of the investigated reaches, thus complying the Water Framework Directive standards. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Interfacial friction factors for air-water co-current stratified flow in inclined channels

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ki Yong; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    The interfacial shear stress is experimentally investigated for co-current air-water stratified flow in inclined rectangular channels having a length of 1854mm, width of 120 mm and height of 40mm at almost atmospheric pressure. Experiments are carried out in several inclinations from 0 deg up to 10 deg. The local film thickness and the wave height are measured at three locations, i.e., L/H = 8,23, and 40. According to the inclination angle, the experimental data are categorized into two groups; nearly horizontal data group (0 deg {<=} {theta} {<=} 0.7 deg), and inclined channel data group (0.7 deg {<=} {theta} {<=} 10 deg ). Experimental observations for nearly horizontal data group show that the flow is not fully developed due to the water level gradient and the hydraulic jump within the channel. For the inclined channel data group, a dimensionless wave height, {Delta}h/h, is empirically correlated in terms of Re{sub G} and h/H. A modified root-mean-square wave height is proposed to consider the effects of the interfacial and wave propagation velocities. It is found that an equivalent roughness has a linear relationship with the modified root-mean-square wave height and its relationship is independent of the inclination. 10 refs., 6 figs., 1 tab. (Author)

  15. Modeling Water and Carbon Budgets in Current and Future Agricultural Land Use

    Science.gov (United States)

    Drewniak, B.; Song, J.; Prell, J.; Kotamarthi, R.; Jacob, R.

    2008-12-01

    Biofuels are a key component of renewable energy mix proposed as a substitute to fossil fuels. Biofuels are suggested as both economical and having potential for reducing atmospheric emissions of carbon from the transportation sector, by building up soil carbon levels when planted on lands where these levels have been reduced by intensive tillage. The purpose of this research is to develop a carbon-nitrogen based crop module (CNC) for the community land model (CLM) and to improve the characterization of the below and above ground carbon sequestration for bioenergy crops. The CNC simulates planting, growing, maturing and harvesting stages for three major crops: maize, soybean and wheat. In addition, dynamic root module is implemented to simulate fine root distribution and development based on relative availability of soil water and nitrogen in the root zone. Coupled CLM-CNC models is used to study crop yields, geographic locations for bioenergy crop production and soil carbon changes. Bioenergy crop cultivation is based on current crop cultivation and future land use change dataset. Soil carbon change has been simulated based on carbon input to the soil from the leaf, stem and root, and carbon emission from soil carbon decomposition. Simulated water and carbon fluxes have been compared with field observations and soil carbon content has been examined under different harvest practices.

  16. Effects of transient bottom water currents and oxygen concentrations on benthic exchange rates as assessed by eddy correlation measurements

    DEFF Research Database (Denmark)

    Holtappels, Moritz; Glud, Ronnie N.; Doris, Daphne

    2013-01-01

    -print area and allows many repetitive flux measurements. A drawback is, however, that the measured flux in the bottom water is not necessarily equal to the flux across the sediment-water interface. A fundamental assumption of the EC technique is that mean current velocities and mean O2 concentrations...

  17. Detecting and monitoring of water inrush in tunnels and coal mines using direct current resistivity method: A review

    OpenAIRE

    Shucai Li; Bin Liu; Lichao Nie; Zhengyu Liu; Mingzhen Tian; Shirui Wang; Maoxin Su; Qian Guo

    2015-01-01

    Detecting, real-time monitoring and early warning of underground water-bearing structures are critically important issues in prevention and mitigation of water inrush hazards in underground engineering. Direct current (DC) resistivity method is a widely used method for routine detection, advanced detection and real-time monitoring of water-bearing structures, due to its high sensitivity to groundwater. In this study, the DC resistivity method applied to underground engineering is reviewed and...

  18. Current and projected water demand and water availability estimates under climate change scenarios in the Weyib River basin in Bale mountainous area of Southeastern Ethiopia

    Science.gov (United States)

    Serur, Abdulkerim Bedewi; Sarma, Arup Kumar

    2017-07-01

    This study intended to estimate the spatial and temporal variation of current and projected water demand and water availability under climate change scenarios in Weyib River basin, Bale mountainous area of Southeastern Ethiopia. Future downscaled climate variables from three Earth System Models under the three RCP emission scenarios were inputted into ArcSWAT hydrological model to simulate different components of water resources of a basin whereas current and projected human and livestock population of the basin is considered to estimate the total annual water demand for various purposes. Results revealed that the current total annual water demand of the basin is found to be about 289 Mm3, and this has to increase by 83.47% after 15 years, 200.67% after 45 years, and 328.78% after 75 years by the 2020s, 2050s, and 2080s, respectively, from base period water demand mainly due to very rapid increasing population (40.81, 130.80, and 229.12% by the 2020s, 2050s, and 2080s, respectively) and climatic variability. The future average annual total water availability in the basin is observed to be increased by ranging from 15.04 to 21.61, 20.08 to 23.34, and 16.21 to 39.53% by the 2020s, 2050s, and 2080s time slice, respectively, from base period available water resources (2333.39 Mm3). The current water availability per capita per year of the basin is about 3112.23 m3 and tends to decline ranging from 11.78 to 17.49, 46.02 to 47.45, and 57.18 to 64.34% by the 2020s, 2050s, and 2080s, respectively, from base period per capita per year water availability. This indicated that there might be possibility to fall the basin under water stress condition in the long term.

  19. Wave propagation against current : a study of the effects of vertical shears of the mean current on the geometrical focusing of water waves

    Science.gov (United States)

    Charland, Jenna; Touboul, Julien; Rey, Vincent

    2013-04-01

    Wave propagation against current : a study of the effects of vertical shears of the mean current on the geometrical focusing of water waves J. Charland * **, J. Touboul **, V. Rey ** jenna.charland@univ-tln.fr * Direction Générale de l'Armement, CNRS Délégation Normandie ** Université de Toulon, 83957 La Garde, France Mediterranean Institute of Oceanography (MIO) Aix Marseille Université, 13288 Marseille, France CNRS/INSU, IRD, MIO, UM 110 In the nearshore area, both wave propagation and currents are influenced by the bathymetry. For a better understanding of wave - current interactions in the presence of a 3D bathymetry, a large scale experiment was carried out in the Ocean Basin FIRST, Toulon, France. The 3D bathymetry consisted of two symmetric underwater mounds on both sides in the mean wave direction. The water depth at the top the mounds was hm=1,5m, the slopes of the mounds were of about 1:3, the water depth was h=3 m elsewhere. For opposite current conditions (U of order 0.30m/s), a huge focusing of the wave up to twice its incident amplitude was observed in the central part of the basin for T=1.4s. Since deep water conditions are verified, the wave amplification is ascribed to the current field. The mean velocity fields at a water depth hC=0.25m was measured by the use of an electromagnetic current meter. The results have been published in Rey et al [4]. The elliptic form of the "mild slope" equation including a uniform current on the water column (Chen et al [1]) was then used for the calculations. The calculated wave amplification of factor 1.2 is significantly smaller than observed experimentally (factor 2). So, the purpose of this study is to understand the physical processes which explain this gap. As demonstrated by Kharif & Pelinovsky [2], geometrical focusing of waves is able to modify significantly the local wave amplitude. We consider this process here. Since vertical velocity profiles measured at some locations have shown significant

  20. Invasive alien plants and water resources in South Africa: current understanding, predictive ability and research challenges

    CSIR Research Space (South Africa)

    Gorgens, AHM

    2004-01-01

    Full Text Available Predictions that invasive alien Plants would use significant amounts of water were a major factor in the establishment of South Africa's Working for Water programme, which aims to protect water resources by clearing these plants. The predictions...

  1. Water masses and zonal current in the Western Tropical Atlantic in October 2007 and January 2008 (AMANDES project

    Directory of Open Access Journals (Sweden)

    A. C. Silva

    2010-11-01

    Full Text Available The properties and circulation of water masses are examined using data collected from a hydrographic and Acoustic Doppler Current profiler in the Western Tropical Atlantic during two cruises of the GEOTRACES process study "AMANDES" (AMazon-ANDEans: AMANDES I (October–November 2007 and AMANDES II (January 2008. In the upper layer (from the sea surface to 150 m means of vertical sections of velocity are showing the structure of the Current (NBC and North Equatorial Countercurrent. In the lower layer (below 150 m the subsurface velocity core of the North Brazil UnderCurrent, Western Boundary Undercurrent (WBUC and northern branch of the South Equatorial Current (nSEC could be observed. In October the WBUC flows southeastward with a velocity of about 0.3 m s−1. In the studied area during October 2007, the NBUC and nSEC are transporting South Atlantic Central Water (SACW from the Southern Hemisphere whereas the WBUC transports North Atlantic Central Water (NACW southeastward. In the deep layers, the North Atlantic Deep Water (NADW is composed of three components: the Upper North Atlantic Deep Water – UNADW (between 1310 and 1650 m, the Middle North Atlantic Deep Water (between 1930 and 2400 m, the Lower North Atlantic Deep Water (centered around 3430 m.

    Off Guyana, the Antartic Intermediate Water (AAIW changes of composition between October 2007 (45.2% ACW, 32.2% AAIWsource and 22.6% UNADW and January 2008 (62.4% ACW, 23.5% AAIWsource and 14.1% UNADW.

    These intermediate waters are significantly warmer, less oxygenated and saltier than their southern source, reflecting both oxygen consumption and mixing with the Atlantic Central Water (ACW and the Upper North Atlantic Deep Water during their northward transit.

  2. Modeling and managing urban water demand through smart meters: Benefits and challenges from current research and emerging trends

    Science.gov (United States)

    Cominola, A.; Giuliani, M.; Castelletti, A.; Piga, D.; Rizzoli, A. E.

    2015-12-01

    Urban population growth, climate and land use change are expected to boost residential water demand in urban contexts in the next decades. In such a context, developing suitable demand-side management strategies is essential to meet future water demands, pursue water savings, and reduce the costs for water utilities. Yet, the effectiveness of water demand management strategies (WDMS) relies on our understanding of water consumers' behavior, their consumption habits, and the water use drivers. While low spatial and temporal resolution water consumption data, as traditionally gathered for billing purposes, hardly support this understanding, the advent of high-resolution, smart metering technologies allowed for quasi real-time monitoring water consumption at the single household level. This, in turn, is advancing our ability in characterizing consumers' behavior, modeling, and designing user-oriented residential water demand management strategies. Several water smart metering programs have been rolled-out in the last two decades worldwide, addressing one or more of the following water demand management phases: (i) data gathering, (ii) water end-uses characterization, (iii) user modeling, (iv) design and implementation of personalized WDMS. Moreover, the number of research studies in this domain is quickly increasing and big economic investments are currently being devoted worldwide to smart metering programs. With this work, we contribute the first comprehensive review of more than 100 experiences in the field of residential water demand modeling and management, and we propose a general framework for their classification. We revise consolidated practices, identify emerging trends and highlight the challenges and opportunities for future developments given by the use of smart meters advancing residential water demand management. Our analysis of the status quo of smart urban water demand management research and market constitutes a structured collection of information

  3. Water Dissociation Phenomena on a Bipolar Membrane——Current-voltage Curve in Relation with Ionic Transport and Limiting Current Density

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The water dissociation mechanism on a bipolar membrane under the electrical field was investigated and characterized in terms of ionic transport and limiting current density. It is considered that the depletion layer exists at the junction of a bipolar membrane, which is coincided with the viewpoint of the most literatures, but we also consider that the thickness and conductivity of this layer is not only related with the increase of the applied voltage but also with the limiting current density. Below the limiting current density, the thickness of the depletion layer keeps a constant and the conductivity decreases with the increase of the applied voltage;while above the limiting current density, the depletion thickness will increase with the increase of the applied voltage and the conductivity keeps a very low constant. Based on the data reported in the literatures and independent determinations, the limiting current density was calculated and the experimental curves Ⅰ- Ⅴ in the two directions were compared with the theoretical calculations. It is demonstrated that above the limiting current density, the experimental results,either in the L-H direction or in the H-L direction, are consistent with the theoretical calculations; below the limiting current density, a slight deviation exists between the experimental and the theoretical results, and between the experimental results in the two directions. The change in Donnan potential due to the asymmetry of the mono-layers and the changes of ionic composition in the two directions is possibly responsible for this deviation.

  4. A New Small Drifter for Shallow Water Basins: Application to the Study of Surface Currents in the Muggia Bay (Italy

    Directory of Open Access Journals (Sweden)

    Carmelo Nasello

    2016-01-01

    Full Text Available A new small drifter prototype for measuring current immediately below the free surface in a water basin is proposed in this paper. The drifter dimensions make it useful for shallow water applications. The drifter transmits its GPS location via GSM phone network. The drifter was used to study the trajectory of the surface current in the Muggia bay, the latter containing the industrial harbor of the city of Trieste (Italy. The analysis has been carried out under a wide variety of wind conditions. As regards the behavior of the drifter, the analysis has shown that it is well suited to detect the water current since its motion is marginally affected by the wind. The study has allowed detecting the main features of the surface circulation within the Muggia bay under different meteorological conditions. Also, the study has shown that the trajectory of the surface current within the bay is weakly affected by the Coriolis force.

  5. Carbon and water cycling in a Bornean tropical rainforest under current and future climate scenarios

    Science.gov (United States)

    Kumagai, Tomo'omi; Katul, Gabriel G.; Porporato, Amilcare; Saitoh, Taku M.; Ohashi, Mizue; Ichie, Tomoaki; Suzuki, Masakazu

    2004-12-01

    We examined how the projected increase in atmospheric CO 2 and concomitant shifts in air temperature and precipitation affect water and carbon fluxes in an Asian tropical rainforest, using a combination of field measurements, simplified hydrological and carbon models, and Global Climate Model (GCM) projections. The model links the canopy photosynthetic flux with transpiration via a bulk canopy conductance and semi-empirical models of intercellular CO 2 concentration, with the transpiration rate determined from a hydrologic balance model. The primary forcing to the hydrologic model are current and projected rainfall statistics. A main novelty in this analysis is that the effect of increased air temperature on vapor pressure deficit ( D) and the effects of shifts in precipitation statistics on net radiation are explicitly considered. The model is validated against field measurements conducted in a tropical rainforest in Sarawak, Malaysia under current climate conditions. On the basis of this model and projected shifts in climatic statistics by GCM, we compute the probability distribution of soil moisture and other hydrologic fluxes. Regardless of projected and computed shifts in soil moisture, radiation and mean air temperature, transpiration was not appreciably altered. Despite increases in atmospheric CO 2 concentration ( Ca) and unchanged transpiration, canopy photosynthesis does not significantly increase if Ci/ Ca is assumed constant independent of D (where Ci is the bulk canopy intercellular CO 2 concentration). However, photosynthesis increased by a factor of 1.5 if Ci/ Ca decreased linearly with D as derived from Leuning stomatal conductance formulation [R. Leuning. Plant Cell Environ 1995;18:339-55]. How elevated atmospheric CO 2 alters the relationship between Ci/ Ca and D needs to be further investigated under elevated atmospheric CO 2 given its consequence on photosynthesis (and concomitant carbon sink) projections.

  6. Current status of materials development of nuclear fuel cladding tubes for light water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Zhengang, E-mail: duan_zg@imr.tohoku.ac.jp [Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Yang, Huilong [Department of Nuclear Engineering, School of Engineering, The University of Tokyo, Nakagun, Ibaraki 319-1188 (Japan); Satoh, Yuhki [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Murakami, Kenta; Kano, Sho; Zhao, Zishou; Shen, Jingjie [Department of Nuclear Engineering, School of Engineering, The University of Tokyo, Nakagun, Ibaraki 319-1188 (Japan); Abe, Hiroaki, E-mail: abe.hiroaki@n.t.u-tokyo.ac.jp [Department of Nuclear Engineering, School of Engineering, The University of Tokyo, Nakagun, Ibaraki 319-1188 (Japan)

    2017-05-15

    Zirconium-based (Zr-based) alloys have been widely used as materials for the key components in light water reactors (LWRs), such as fuel claddings which suffer from waterside corrosion, hydrogen uptakes and strength loss at elevated temperature, especially during accident scenarios like the lost-of-coolant accident (LOCA). For the purpose of providing a safer, nuclear leakage resistant and economically viable LWRs, three general approaches have been proposed so far to develop the accident tolerant fuel (ATF) claddings: optimization of metallurgical composition and processing of Zr-based alloys, coatings on existing Zr-based alloys and replacement of current Zr-based alloys. In this manuscript, an attempt has been made to systematically present the historic development of Zr-based cladding, including the impacts of alloying elements on the material properties. Subsequently, the research investigations on coating layer on the surface of Zr-based claddings, mainly referring coating materials and fabrication methods, have been broadly reviewed. The last section of this review provides the introduction to alternative materials (Non-Zr) to Zr-based alloys for LWRs, such as advanced steels, Mo-based, and SiC-based materials.

  7. Ice-water vortex at the edge of the East Greenland current

    Energy Technology Data Exchange (ETDEWEB)

    Wadhams, P.; Squire, V.A.

    1983-03-30

    During the Ymer-80 cruise in August 1980 we observed an ice feature of 60-km diameter having the shape of a breaking wave. It lay at the edge of the East Greenland drift ice in Fram Strait with its center at 79/sup 0/15'N, 00/sup 0/38'E, and the wave was breaking upstream relative to the East Greenland current. Two conductivity, temperature, and depth sections across the feature in N-S and E-W directions revealed warm (up to 4.3 C) water some 60 km inside the polar front, in lenses centered at 40-m depth but with an effect to beyond 600 m. The temperature anomalies were accompanied by salinity anomalies so that there was little net effect on the density profile. The form of the sections, together with the ice distribution (observed by vertical photography from a helicopter) and surface motion (observed by tracking four radar transponders) all suggest that the feature is a vortex produced by an instability in the polar front. It has similar characteristics to vortices investigated experimentally and theoretically by Griffiths and Linden (1981a, b, 1982) and observationally by Wadhams et al. (1979).

  8. An ice-water vortex at the edge of the East Greenland Current

    Science.gov (United States)

    Wadhams, P.; Squire, V. A.

    1983-03-01

    During the Y mer-80 cruise in August 1980 we observed an ice feature of 60-km diameter having the shape of a breaking wave. It lay at the edge of the East Greenland drift ice in Fram Strait with its center at 79°15'N, 00°38'E, and the wave was breaking upstream relative to the East Greenland Current. Two conductivity, temperature, and depth sections across the feature in N-S and E-W directions revealed warm (up to 4.3°C) water some 60 km inside the polar front, in lenses centered at 40-m depth but with an effect to beyond 600 m. The temperature anomalies were accompanied by salinity anomalies so that there was little net effect on the density profile. The form of the sections, together with the ice distribution (observed by vertical photography from a helicopter) and surface motion (observed by tracking four radar transponders) all suggest that the feature is a vortex produced by an instability in the polar front. It has similar characteristics to vortices investigated experimentally and theoretically by Griffiths and Linden (1981a, b, 1982) and observationally by Wadhams et al. (1979).

  9. Dynamics of turbulent western-boundary currents at low latitude in a shallow-water model

    Science.gov (United States)

    Akuetevi, C. Q. C.; Wirth, A.

    2015-06-01

    The dynamics of low latitude turbulent western-boundary currents (WBCs) crossing the Equator are considered using numerical results from integrations of a reduced-gravity shallow-water model. For viscosity values of 1000 m2 s-1 and greater, the boundary layer dynamics compares well to the analytical Munk-layer solution. When the viscosity is reduced, the boundary layer becomes turbulent and coherent structures in the form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer, VSL) and dipoles appear. Three distinct boundary layers emerge, the VSL, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity; the second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. Characteristic scales of the dynamics and dissipation are determined. A pragmatic approach to determine the eddy viscosity diagnostically for coarse-resolution numerical models is proposed.

  10. Advanced Steels for Accident Tolerant Fuel Cladding in Current Light Water Reactors

    Science.gov (United States)

    Rebak, Raul B.

    After the March 2011 Fukushima events, the U.S. Congress directed the Department of Energy (DOE) to focus efforts on the development of fuel cladding materials with enhanced accident tolerance. In comparison with the stand-ard UO2-Zirconium based system, the new fuels need to tolerate loss of active cooling in the core for a considerably longer time period while maintaining or improving the fuel performance during normal operation conditions. Advanced steels such as iron-chromium-aluminum (FeCrAl) alloys are being investigated for degradation behavior both under normal operation conditions in high temperature water (e.g. 288°C) and under accident conditions for reaction with steam up to 1400°C. Commercial and experimental alloys were tested for several periods of time in 100% superheated steam from 800°C to 1475°C. Results show that FeCrAl alloys significantly outperform the resistance in steam of the current zirconium alloys.

  11. Dynamics of turbulent western boundary currents at low latitude in a shallow water model

    Directory of Open Access Journals (Sweden)

    C. Q. C. Akuetevi

    2014-11-01

    Full Text Available The dynamics of low latitude turbulent western boundary currents crossing the equator is considered using numerical results from integrations of a reduced gravity shallow-water model. For viscosity values of 1000 m2 s−1 and more, the boundary layer dynamics compares well to the analytical Munk-layer solution. When the viscosity is reduced, the boundary layer becomes turbulent and coherent structures in form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer and dipoles appear. Three distinct boundary layers emerge, the viscous sub-layer, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity. The second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. Characteristic scales of the dynamics and dissipation are determined. A pragmatic approach to determine the eddy viscosity diagnostically for coarse resolution numerical models is proposed.

  12. Dynamics of turbulent western boundary currents at low latitude in a shallow water model

    Directory of Open Access Journals (Sweden)

    C. Q. C. Akuetevi

    2014-03-01

    Full Text Available The dynamics of low latitude turbulent western boundary currents, subject to two different types of idealized wind forcing, Monsoon Wind and Trade Wind, is considered using numerical results from integrations of a reduced gravity shallow-water model. For viscosity values of 1000 m2 s−1 and above, the boundary layer dynamics compares well to the analytical solutions of the Munk-layer and the inertial-layer, derived from quasigeostrophic theory. Modifications due to variations in the layer thickness (vortex stretching are only important close to the boundary. When the viscosity is reduced the boundary layer becomes turbulent and coherent structures in form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer and dipoles appear. Three distinct boundary layers emerge, the viscous sub-layer, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity. The second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. A pragmatic approach to determine the eddy viscosity diagnostically for coarse resolution numerical models is proposed.

  13. CLASSIFYING COASTAL WATERS: HISTORICAL PERSPECTIVE AND CURRENT FOCUS ON AQUATIC STRESSORS

    Science.gov (United States)

    Coastal ecosystems are ecologically and commercially productive habitats that are experiencing significant impacts associated with accelerated population growth in coastal zones. The Clean Water Act requires identification of impaired water bodies and determination of the causes ...

  14. Development of Harmonic-Noise Reduction Technology in Diagnostic Method using AC Loss Current for Water Treed XLPE Cable

    Science.gov (United States)

    Tsujimoto, Tomiyuki; Nakade, Masahiko; Yagi, Yukihiro; Ishii, Noboru

    Water tree is one of the degradation aspects of XLPE cables used for under-ground distribution or transmission lines. We have developed the loss current method using 3rd harmonic in AC loss current for cable diagnosis. Harmonic components in loss current arise as a result of the non-linear voltage-current characteristics of water trees. We confirmed that the 3rd harmonic in AC loss current had good correlation with water tree growth and break down strength. After that, we have applied this method to the actual 66kV XLPE cable lines. Up to now, the number of the application results is more than 120 lines. In this method, it is sometimes said that the degradation signal (3rd harmonic in loss current) is affected by the 3rd harmonic in the test voltage. To indicate and solve this problem, we investigated the extent of influence by 3rd harmonic in the test voltage, and found the rule of the influence. As a result, we developed a new technique of harmonic-noise reduction in loss current method that enabled a more highly accurate diagnosis and confirmed the effectiveness of this new technique by simulations and experiments with actual cables.

  15. Sustainability of small reservoirs and large scale water availability under current conditions and climate change

    NARCIS (Netherlands)

    Krol, Martinus S.; de Vries, Marjella J.; van Oel, P.R.; Carlos de Araújo, José

    2011-01-01

    Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts

  16. Best urban water management practices to prevent waterborne infectious diseases under current and future scenarios

    NARCIS (Netherlands)

    de Man-van der Vliet, H.

    2014-01-01

    Water in urban areas may pose a public health risk when people are exposed to urban water, because it may contain pathogens. These pathogens may originate from fecal bird droppings, runoff from paved surfaces (including e.g. dog feces), growth of micro-organisms in water and in some cases discharges

  17. Sustainability of small reservoirs and large scale water availability under current conditions and climate change

    NARCIS (Netherlands)

    Krol, Maarten S.; Vries, de Marjella J.; Oel, van Pieter R.; Carlos de Araújo, José

    2011-01-01

    Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts

  18. Coal-water slurry fuel production: Its evolution and current status in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, J.L.; Miller, B.G.; Scaroni, A.W. [Pennsylvania State Univ., University Park, PA (United States)

    1997-12-31

    Interest in the US in utilizing bituminous coal in a slurry form has evolved substantially over the last two decades. In the mid-1970`s, technologies to utilize coal-oil mixtures (COMs) as potential fuel oil replacements for utility and industrial boilers were developed as a consequence of escalating world oil prices. To further reduce dependency on imported oil, interest shifted away from COMs to coal-water slurry fuels (CWSFs) because higher solids loadings were obtainable while eliminating the use of oil. Research which focused on the use of CWSF as a potential fuel oil replacement peaked in the mid to late-1980`s as a result of a decline in world oil prices. During the late 1980`s and early 1990`s, coal suppliers and coal-fired utilities began to evaluate the production of CWSF using bituminous coal fines from fine coal cleaning circuits in an effort to reduce dewatering/drying costs. This marked a philosophical change in the driving force behind the utilization of CWSF in the US. In an effort to broaden the supply of coal fines, The Pennsylvania State University (Penn State) and the Pennsylvania Electric Company (Penelec) surveyed a series of fine coal impoundments in western Pennsylvania to determine the quality, cleanability, and slurryability of the coal fines contained therein. The development and commercialization of recovery technologies, cleaning techniques, and CWSF reentrainment circuits, coupled with an interest by utilities to utilize low-cost fuels, has fostered the recovery of impounded coal fines. In addition to the fine coal impoundments, fine coal cleaning circuits which actively dispose of process water having suspended coal fines (e.g. centrifuge effluent) are being examined to determine if the fines can be recovered and thickened into a low solids CWSF. The paper describes required physical and chemical properties of a CWSF for boiler applications. There is a growing awareness that CWSF is a fuel form that can be cofired with coal. The

  19. Human-water interface in hydrological modelling: current status and future directions

    Science.gov (United States)

    Wada, Yoshihide; Bierkens, Marc F. P.; de Roo, Ad; Dirmeyer, Paul A.; Famiglietti, James S.; Hanasaki, Naota; Konar, Megan; Liu, Junguo; Müller Schmied, Hannes; Oki, Taikan; Pokhrel, Yadu; Sivapalan, Murugesu; Troy, Tara J.; van Dijk, Albert I. J. M.; van Emmerik, Tim; Van Huijgevoort, Marjolein H. J.; Van Lanen, Henny A. J.; Vörösmarty, Charles J.; Wanders, Niko; Wheater, Howard

    2017-08-01

    Over recent decades, the global population has been rapidly increasing and human activities have altered terrestrial water fluxes to an unprecedented extent. The phenomenal growth of the human footprint has significantly modified hydrological processes in various ways (e.g. irrigation, artificial dams, and water diversion) and at various scales (from a watershed to the globe). During the early 1990s, awareness of the potential for increased water scarcity led to the first detailed global water resource assessments. Shortly thereafter, in order to analyse the human perturbation on terrestrial water resources, the first generation of large-scale hydrological models (LHMs) was produced. However, at this early stage few models considered the interaction between terrestrial water fluxes and human activities, including water use and reservoir regulation, and even fewer models distinguished water use from surface water and groundwater resources. Since the early 2000s, a growing number of LHMs have incorporated human impacts on the hydrological cycle, yet the representation of human activities in hydrological models remains challenging. In this paper we provide a synthesis of progress in the development and application of human impact modelling in LHMs. We highlight a number of key challenges and discuss possible improvements in order to better represent the human-water interface in hydrological models.

  20. Human–water interface in hydrological modelling: current status and future directions

    Directory of Open Access Journals (Sweden)

    Y. Wada

    2017-08-01

    Full Text Available Over recent decades, the global population has been rapidly increasing and human activities have altered terrestrial water fluxes to an unprecedented extent. The phenomenal growth of the human footprint has significantly modified hydrological processes in various ways (e.g. irrigation, artificial dams, and water diversion and at various scales (from a watershed to the globe. During the early 1990s, awareness of the potential for increased water scarcity led to the first detailed global water resource assessments. Shortly thereafter, in order to analyse the human perturbation on terrestrial water resources, the first generation of large-scale hydrological models (LHMs was produced. However, at this early stage few models considered the interaction between terrestrial water fluxes and human activities, including water use and reservoir regulation, and even fewer models distinguished water use from surface water and groundwater resources. Since the early 2000s, a growing number of LHMs have incorporated human impacts on the hydrological cycle, yet the representation of human activities in hydrological models remains challenging. In this paper we provide a synthesis of progress in the development and application of human impact modelling in LHMs. We highlight a number of key challenges and discuss possible improvements in order to better represent the human–water interface in hydrological models.

  1. Bleaching Susceptibility and Recovery of Colombian Caribbean Corals in Response to Water Current Exposure and Seasonal Upwelling

    Science.gov (United States)

    Bayraktarov, Elisa; Pizarro, Valeria; Eidens, Corvin; Wilke, Thomas; Wild, Christian

    2013-01-01

    Coral bleaching events are globally occurring more frequently and with higher intensity, mainly caused by increases in seawater temperature. In Tayrona National Natural Park (TNNP) in the Colombian Caribbean, local coral communities are subjected to seasonal wind-triggered upwelling events coinciding with stronger water currents depending on location. This natural phenomenon offers the unique opportunity to study potential water current-induced mitigation mechanisms of coral bleaching in an upwelling influenced region. Therefore, coral bleaching susceptibility and recovery patterns were compared during a moderate and a mild bleaching event in December 2010 and 2011, and at the end of the subsequent upwelling periods at a water current-exposed and -sheltered site of an exemplary bay using permanent transect and labeling tools. This was accompanied by parallel monitoring of key environmental variables. Findings revealed that in 2010 overall coral bleaching before upwelling was significantly higher at the sheltered (34%) compared to the exposed site (8%). Whereas 97% of all previously bleached corals at the water current-exposed site had recovered from bleaching by April 2011, only 77% recovered at the sheltered site, but 12% had died there. In December 2011, only mild bleaching (corals recovered significantly at both sites in the course of upwelling. No differences in water temperatures between sites occurred, but water current exposure and turbidity were significantly higher at the exposed site, suggesting that these variables may be responsible for the observed site-specific mitigation of coral bleaching. This indicates the existence of local resilience patterns against coral bleaching in Caribbean reefs. PMID:24282551

  2. Bleaching susceptibility and recovery of Colombian Caribbean corals in response to water current exposure and seasonal upwelling.

    Science.gov (United States)

    Bayraktarov, Elisa; Pizarro, Valeria; Eidens, Corvin; Wilke, Thomas; Wild, Christian

    2013-01-01

    Coral bleaching events are globally occurring more frequently and with higher intensity, mainly caused by increases in seawater temperature. In Tayrona National Natural Park (TNNP) in the Colombian Caribbean, local coral communities are subjected to seasonal wind-triggered upwelling events coinciding with stronger water currents depending on location. This natural phenomenon offers the unique opportunity to study potential water current-induced mitigation mechanisms of coral bleaching in an upwelling influenced region. Therefore, coral bleaching susceptibility and recovery patterns were compared during a moderate and a mild bleaching event in December 2010 and 2011, and at the end of the subsequent upwelling periods at a water current-exposed and -sheltered site of an exemplary bay using permanent transect and labeling tools. This was accompanied by parallel monitoring of key environmental variables. Findings revealed that in 2010 overall coral bleaching before upwelling was significantly higher at the sheltered (34%) compared to the exposed site (8%). Whereas 97% of all previously bleached corals at the water current-exposed site had recovered from bleaching by April 2011, only 77% recovered at the sheltered site, but 12% had died there. In December 2011, only mild bleaching (corals recovered significantly at both sites in the course of upwelling. No differences in water temperatures between sites occurred, but water current exposure and turbidity were significantly higher at the exposed site, suggesting that these variables may be responsible for the observed site-specific mitigation of coral bleaching. This indicates the existence of local resilience patterns against coral bleaching in Caribbean reefs.

  3. Bleaching susceptibility and recovery of Colombian Caribbean corals in response to water current exposure and seasonal upwelling.

    Directory of Open Access Journals (Sweden)

    Elisa Bayraktarov

    Full Text Available Coral bleaching events are globally occurring more frequently and with higher intensity, mainly caused by increases in seawater temperature. In Tayrona National Natural Park (TNNP in the Colombian Caribbean, local coral communities are subjected to seasonal wind-triggered upwelling events coinciding with stronger water currents depending on location. This natural phenomenon offers the unique opportunity to study potential water current-induced mitigation mechanisms of coral bleaching in an upwelling influenced region. Therefore, coral bleaching susceptibility and recovery patterns were compared during a moderate and a mild bleaching event in December 2010 and 2011, and at the end of the subsequent upwelling periods at a water current-exposed and -sheltered site of an exemplary bay using permanent transect and labeling tools. This was accompanied by parallel monitoring of key environmental variables. Findings revealed that in 2010 overall coral bleaching before upwelling was significantly higher at the sheltered (34% compared to the exposed site (8%. Whereas 97% of all previously bleached corals at the water current-exposed site had recovered from bleaching by April 2011, only 77% recovered at the sheltered site, but 12% had died there. In December 2011, only mild bleaching (<10% at both sites was observed, but corals recovered significantly at both sites in the course of upwelling. No differences in water temperatures between sites occurred, but water current exposure and turbidity were significantly higher at the exposed site, suggesting that these variables may be responsible for the observed site-specific mitigation of coral bleaching. This indicates the existence of local resilience patterns against coral bleaching in Caribbean reefs.

  4. Water scarcity in the Spanish part of the Douro basin: current status and future scenarios

    Science.gov (United States)

    Jesús Vicente, David; Rodriguez-Sinobas, Leonor

    2016-04-01

    In general in Europe only 5 % of renewable freshwater resources is abstracted each year however, water availability and populations are unevenly distributed. Except in some northern and sparsely-populated areas that possess abundant resources, water scarcity occurs in many areas of Europe, particularly in the Mediterranean countries. It has been accentuated in the past decades by the increase of drought periods due to climate change. In this regard, the European Policy has addressed both drought (related to natural processes) and water scarcity (influenced by human activity) through several Directives and Communications. These have considered a common water stress indicators such as the Water Exploitation Index (WEI) and its upgraded version WEI+. They quantify the percentage of total freshwater used compared to the total renewable freshwater resources available. Their estimations help the stakeholders identify territories vulnerable to human activity pressure on water resources, and hence prone to suffer problems of water stress. The index WEI+ estimates better than WEI the actual balance between renewable water resources and water consumption, since it include the returns from water uses in its calculation. In addition, the European Community is still working on issues dealing with the temporal and spatial scaling and have suggested to adopt the river basin and monthly temporal resolution instead of the national scale and annual basis considered in the former documents. Within this context, this study assesses the water scarcity in the Spanish part of the Douro basin estimated by the WEI+ index. According to previous studies and depending on the specific period selected, this basin is near 'water stress'. In order to clarify this issue, the WEI+ index has been estimated. A detailed methodology for its calculation is presented which uses information from the water resources management model 'Aquatool' and its simulation module SIMGES which is widely applied in

  5. Strong Water Isotopic Anomalies in the Martian Atmosphere: Probing Current and Ancient Reservoirs

    Science.gov (United States)

    Villanueva, G. L.; Mumma, M. J.; Novak, R. E.; Käufl, H. U.; Hartogh, P.; Encrenaz, T.; Tokunaga, A.; Khayat, A.; Smith, M. D.

    2015-01-01

    We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

  6. Analysis of the Current Water Environment Quality of Xiaoquan Tributary in Ba’nan District

    Institute of Scientific and Technical Information of China (English)

    Shuang; HU

    2015-01-01

    With the class V water standards of Surface Water Quality Standards( GB3838-2002) as a basis for evaluation,this paper monitors the water quality of Hongqi Village and Hongxing Village monitoring sections in Xiaoquan tributary of Huaxi River,and uses the single factor index method for evaluation.The monitoring results show that the water quality of the two sections falls within inferior class V,and Xiaoquan tributary can not meet the water functional requirements.The main reason for pollution lies in the pollution from the upstream sewage,and it is recommended to strengthen inter-regional water pollution control coordination mechanism and effectively address river pollution problems.

  7. Analysis of (unsustainability of the current water: Supply strategy in Serbia

    Directory of Open Access Journals (Sweden)

    Dokmanović Petar B.

    2015-01-01

    Full Text Available Planned construction of more than 30 dams, lake-reservoirs and regional water-supply systems, are the basis of long-term water-supply strategy of the Republic of Serbia. The strategy was adopted in the 1970s and some experiences so far indicate the necessity of revision and rationalization, because of the following: - Quantity and effects of realized works are far lower than planned. The main reasons is the lack of finance as well as some systemic weaknesses shown in the processes of construction and management of the water systems. - Forecasted demographic growth as well as water consumption rates, dating back to 1970s-80s, are significantly oversized. -Global and domestic experiences in the field of construction and management of artificial lake- reservoirs indicate numerous techno-economic and environmental risks and negative consequences. - So far results of hydrogeological researches and groundwater capturing in Serbia show that this resource is a very good basis for municipal water-supply in the most part of the territory. - Water pipe lines are, on average, in very poor condition. Water supply deficits are recorded frequently because of enormous losses in distribution. The rationalization means an approach suited to the real water-supply need as well as to the financial and organizational capabilities. Orientation to the available groundwater resources is the basic guideline. One of the priorities is repairing of water pipe networks. This approach allows: - Much faster solving of water-supply problems - Big financial savings in the construction of dams, reservoirs, regional pipelines, raw water treatment plants as well as in the space adaptation and maintenance of regional water-supply systems.

  8. Current meter data from moored current meter casts in the Coastal Waters of Washington/Oregon as part of the Land-Margin Ecosystem Research (LEML) project, 06 May 1997 - 19 October 1997 (NODC Accession 9800193)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of Washington/Oregon from May 6, 1997 to October 19, 1997. Data were...

  9. Current meter data from moored current meter casts in the Coastal Waters of SE Alaska/Brit.Colum. as part of the Long-Range Effects Program Puget Sound project from 15 March 1983 - 01 November 1983 (NODC Accession 8600321)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of SE Alaska/Brit.Colum. from March 15, 1983 to November 1, 1983. Data were...

  10. Current meter data from moored current meter casts in the Coastal Waters of Hawaii as part of the Ocean Thermal Energy Conversion (OTEC) project from 23 September 1980 - 01 December 1980 (NODC Accession 8100469)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of Hawaii from September 23, 1980 to December 1, 1980. Data were submitted...

  11. Current meter data from moored current meter casts in the Coastal Waters of S. Alaska as part of the Fisheries-Oceanography Cooperative Investigations (FOCI) project from 21 August 1984 - 01 July 1985 (NCEI Accession 8700053)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of S. Alaska from August 21, 1984 to July 1, 1985. Data were submitted by...

  12. Some Considerations on an Underwater Robotic Manipulator Subjected to the Environmental Disturbances Caused by Water Current

    Directory of Open Access Journals (Sweden)

    Kołodziejczyk Waldemar

    2016-03-01

    Full Text Available The objective of this paper is to discuss some of the issues associated with environmental load on the three-link serial manipulator caused by underwater current. We have conducted CFD simulations to investigate hydrodynamic effects induced by changing current direction and changing with time current speed in order to better understand the physics of the problem. The results are presented in terms of moments of hydrodynamic forces plotted against relative position of the current and the robotic arm. Time history of hydrodynamic loads according to periodically changing current speed is presented and discussed.

  13. Ion current behaviors of mesoporous zeolite-polymer composite nanochannels prepared by water-assisted self-assembly.

    Science.gov (United States)

    Zhang, Wenjuan; Meng, Zheyi; Zhai, Jin; Heng, Liping

    2014-04-07

    Inspired by the asymmetry of biological ion channels in structure and composition, we designed a novel type of artificial asymmetric nanochannels based on mesoporous zeolite (MCM-41) and polyimide (PI) by water-assisted self-assembly. Meanwhile, we studied ionic current behaviors and rectifying characteristics of the mesoporous zeolite-polymer composite nanochannels.

  14. WETLANDS AND WATER QUALITY TRADING: REVIEW OF CURRENT SCIENCE AND ECONOMIC PRACTICES WITH SELECTED CASE STUDIES

    Science.gov (United States)

    The study evaluates the technical, economic, and administrative aspects of establishing water quality trading (WQT) programs where the nutrient removal capacity of wetlands is used to improve water quality. WQT is a potentially viable approach for wastewater dischargers to cost-e...

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

    Science.gov (United States)

    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…

  16. Current and future water issues in the Oldman River Basin of Alberta, Canada.

    Science.gov (United States)

    Byrne, J; Kienzle, S; Johnson, D; Duke, G; Gannon, V; Selinger, B; Thomas, J

    2006-01-01

    Long-term trends in alpine and prairie snow pack accumulation and melt are affecting streamflow within the Oldman River Basin in southern Alberta, Canada. Unchecked rural and urban development also has contributed to changes in water quality, including enhanced microbial populations and increased waterborne pathogen occurrence. In this study we look at changing environment within the Oldman River Basin and its impact on water quality and quantity. The cumulative effects include a decline in net water supplies, and declining quality resulting in increased risk of disease. Our data indicates that decreases in the rate of flow of water can result in sedimentation of bacterial contaminants within the water column. Water for ecosystems, urban consumption, recreation and distribution through irrigation is often drawn from waterholding facilities such as dams and weirs, and concern must be expressed over the potential for contaminate build-up and disproportionate potential of these structures to pose a risk to human and animal health. With disruption of natural flow rates for water resulting from environmental change such as global warming and/or human intervention, increased attention needs to be paid to use of best management practices to protect source water supplies.

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

    Science.gov (United States)

    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…

  18. WETLANDS AND WATER QUALITY TRADING: REVIEW OF CURRENT SCIENCE AND ECONOMIC PRACTICES WITH SELECTED CASE STUDIES

    Science.gov (United States)

    The study evaluates the technical, economic, and administrative aspects of establishing water quality trading (WQT) programs where the nutrient removal capacity of wetlands is used to improve water quality. WQT is a potentially viable approach for wastewater dischargers to cost-e...

  19. Sectoral Vulnerabilities to Changing Water Resources: Current and Future Tradeoffs between Supply and Demand in the Conterminous U.S

    Science.gov (United States)

    Meldrum, J.; Averyt, K.; Caldwell, P.; Sun, G.; Huber-lee, A. T.; McNulty, S.

    2012-12-01

    Assessing the sustainability of human activities depends, in part, on the availability of water supplies to meet the demands of those activities. Thermoelectric cooling, agriculture, and municipal uses all compete for water supplies, but each sector differs in its characteristic ratio of water consumption versus withdrawals. This creates different implications for contributing to water supply stress and, conversely, vulnerabilities within each sector to changing water supplies. In this study, we use two measures of water stress, relating to water withdrawals and to water consumption, and calculate the role of each of these three sectors in contributing to the two different measures. We estimate water stress with an enhanced version of the Water Supply Stress Index (WaSSI), calculating the ratio of water demand to water supply at the 8-digit Hydrologic Unit Code (HUC) scale (Sun et al. 2008, 2011; Caldwell et al. 2011). Current water supplies are based on an integrated water balance and flow routing model of the conterminous United States, which accounts for surface water supply, groundwater supply, and major return flows. Future supplies are based on simulated regional changes in streamflow in 2050 from an ensemble of 12 climate models (Milly et al. 2005). We estimate water demands separately for agriculture, municipal uses, and thermoelectric cooling, with the first two based on Kenny et al. (2005) and the last on the approach of Averyt et al. (2011). We find substantial regional variation not only in the overall WaSSI for withdrawals and consumption but also in contribution of the three water use sectors to that total. Results suggest that the relative vulnerabilities of different sectors of human activity to water supply stress vary spatially and that policies for alleviating that stress must consider the specific, regional context of the tradeoffs between competing water demands. Ref's: Averyt, K., Fisher, J., Huber-Lee, A., Lewis, A., Macknick, J., Madden, N

  20. Drinking water quality in household supply infrastructure--A survey of the current situation in Germany.

    Science.gov (United States)

    Völker, Sebastian; Schreiber, Christiane; Kistemann, Thomas

    2010-06-01

    As a result of the amendment to the German Drinking Water Ordinance in 2001, local public health authorities are obliged to monitor the water supply in installations providing water for public use (Section 18 German Drinking Water Ordinance). With a systematic and nationwide survey of locally available data relating to hygienic drinking water quality and the existing drinking water infrastructure in buildings, the extent of microbial contamination of in-building distribution systems in Germany is intended to be assessed. To gain an overview of the microbial contamination of drinking water in public buildings all 419 local public health authorities in Germany were contacted in 2007. In a detailed study with a representative cooperation level of 5% of these local public health authorities, the available data relating to microbiological, chemical, physical and technical parameters gained from in-building distribution systems were collected. Drinking water parameters were combined with regard to the total number of analyses and the absolute number as well as the percentage of limit compliance failures (n=108,288). Limits exceeded were classified as the failure to comply with the German Drinking Water Ordinance, DVGW technical regulations and Federal Environment Agency recommended limits. The highest rates of samples exceeding these limits were found for the parameter Legionella sp. which contaminated 12.8% of all samples (n=22,786; limit: 100 CFU/100ml), followed by heterotrophic plate count at 36 degrees C (3.5%, n=10,928; limit: 100 CFU/1 ml) and Pseudomonas sp. (2.9%, n=3468; limit: 0 CFU/100ml). Legionella sp. and Pseudomonas sp. pose a direct health risk to immunosuppressed users. Additionally, for some chemical parameters, such as nickel, iron and lead, a potential risk for the health of consumers was detected. Further data analysis may reveal whether this contamination is related to stagnation where there is only sporadic use or whether other factors are

  1. Technical review and evaluation of the economics of water desalination: Current and future challenges for better water supply sustainability

    KAUST Repository

    Ghaffour, Noreddine

    2013-01-01

    Desalination capacity has rapidly increased in the last decade because of the increase in water demand and a significant reduction in desalination cost as a result of significant technological advances, especially in the reverse osmosis process. The cost of desalinated seawater has fallen below US$0.50/m3 for a large scale seawater reverse osmosis plant at a specific location and conditions while in other locations the cost is 50% higher (US$1.00/m3) for a similar facility. In addition to capital and operating costs, other parameters such as local incentives or subsidies may also contribute to the large difference in desalted water cost between regions and facilities. Plant suppliers and consultants have their own cost calculation methodologies, but they are confidential and provide water costs with different accuracies. The few existing costing methodologies and software packages such as WTCost© and DEEP provide an estimated cost with different accuracies and their applications are limited to specific conditions. Most of the available cost estimation tools are of the black box type, which provide few details concerning the parameters and methodologies applied for local conditions. Many desalination plants built recently have greater desalinated water delivery costs caused by special circumstances, such as plant remediation or upgrades, local variation in energy costs, and site-specific issues in raw materials costs (e.g., tariffs and transportation). Therefore, the availability of a more transparent and unique methodology for estimating the cost will help in selecting an appropriate desalination technology suitable for specific locations with consideration of all the parameters influencing the cost. A techno-economic evaluation and review of the costing aspects and the main parameters influencing the total water cost produced by different desalination technologies are herein presented in detail. Some recent developments, such as the increase of unit capacity

  2. Groundwater science in water-utility operations: global reflections on current status and future needs

    Science.gov (United States)

    Foster, Stephen; Sage, Rob

    2017-08-01

    The relevance of groundwater science to water-utility operations is analysed from a broad international perspective, identifying key concerns and specific opportunities for the future. The strategic importance worldwide of water utilities assuming the role of lead stakeholders for integrated groundwater resource management, recognizing their often considerable technical know-how and highly significant data holdings, is emphasized. Concurrently, the utilities themselves will need an ever-closer appreciation of groundwater-system behaviour if they are to manage efficiently their water-supply and wastewater operations.

  3. Numerical simulations of the current state of waters and sea ice in the Arctic Ocean

    Directory of Open Access Journals (Sweden)

    E. N. Golubeva

    2015-01-01

    Full Text Available The paper presents results of numerical simulation of variability of the sea ice area and water circulation in the Arctic Ocean performed with use of the atmosphere reanalysis data for the period from middle of the last century to the present time. The model results reflect the ocean responses to changes of the atmosphere circulation regimes that manifests in changes of trajectories of waters coming into the Arctic Ocean from the Pacific and Atlantic oceans. The model results show influence of the Pacific and Atlantic waters on distribution and thickness of the Arctic ice. 

  4. Eddies on the boundary between the Kuroshio current and coastal waters observed by HF ocean surface radar

    Science.gov (United States)

    Nadai, A.

    2016-02-01

    The HF ocean surface radar (HFOSR) is one of the powerful tools to measure the ocean current parameters like surface currents. Three observations of the Kuroshio current in the Tokara straight using HFOSR had done by the National Institute of Information and Comunications Technology (NICT: the former name is the Communications Research Laboratory). The first-order echoes on Doppler spectra of HFOSR shows broaden and splitting shape in the region of the border between the Kuroshio currents and coastal waters. The surface velocity maps show the existence of eddy on the border. The investigation of the mechanism of broadening first order-echoes by Nadai (2006) revealed that the modulation of wave fields from surface currents like eddy is the cause of broadening and the measured current fields also influenced the modulated wave fields. Moreover, Nadai (2006) also suggested that the influence is able to reduce using the average of two radial velocities extracted by the first-order echoes. In this paper, the results of current field observation around the border between the Kuroshio current and coastal waters are presented. Many small scale eddies are observed at the border of the Kuroshio current and coastal waters. The typical radius of the eddies is about 10km. Usury the observation of such a small scale eddy is difficult, but the eddies with same scale are observed by airborne synthetic aperture radar in the same area at different time. The eddies shows strong rotation as the typical tangential speed is about 1m/s. While the typical speed of the Kuroshio current is about 1.5m/s, the typical speed of the eddy movements is about 0.7m/s. No eddies generated in the radar coverage, but one or two eddies entered in the radar coverage a day. Therefore the origin of these eddies will exist in the upstream area of the radar coverage. Using the compensation method for the influence of the modulated wave field suggested by Nadai (2006), the eddies shows weak divergence. It is

  5. On water transport in polymer electrolyte membranes during the passage of current

    DEFF Research Database (Denmark)

    Berning, Torsten

    2011-01-01

    This article discusses an approach to model the water transport in the membranes of PEM fuel cells during operation. Starting from a frequently utilized equation the various transport mechanisms are analyzed in detail. It is shown that the commonly used approach to simply balance the electro-osmotic...... drag (EOD) with counter diffusion and/or hydraulic permeation is flawed, and that any net transport of water through the membrane is caused by diffusion. Depending on the effective drag the cathode side of the membrane may experience a lower hydration than the anode side. The effect of a water......-uptake layer on the net water transport will also be pictured. Finally, the effect of EOD is visualized using “Newton’s cradle”....

  6. Water characteristics and transport of the Antarctic circumpolar current in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; Mathew, B.

    Geostrophic velocities are computed across meridians 37 degrees E and 105 degrees E using hydrographic data. The estimated mass transport is represented on a temperature - salinity diagram. The characteristics of the water within the Antarctic...

  7. Current status of bacteriological parameters and DOC/POC in Xiamen coastal waters

    Institute of Scientific and Technical Information of China (English)

    Khalid Maskaoui; Tianling Zheng; Huasheng Hong; Zhiming Yu; Zhong Hu; Yun Tian; Lizhe Cai

    2003-01-01

    The surface and bottom waters samples were collected from six locations in Xiamen west-em sea. The quantified estimation of bacterial production (3H-thymidine method) and observation ofbacterial heterotrophic activity (14C-glucose method) have been made in order to have a better under-standing of the role of marine bacteria and their activities. The results showed that the mean value ofbacterial heterotrophic activity was 9 × 108 cells/(L. h) in the surface waters and 2.6 × 108 cells/( L. h)in the bottom waters. The mean value of bacterial production was 38 × 108 cells/( L. h) in the surfacewaters and 7.1 × 108 cells/(L.h) in the bottom waters. The relationship between bacterial production,heterotrophic activity, POC and DOC measured during this survey were discussed. The good under-standing of the relationship between bacteria activity and total coliform was addressed.

  8. Technologies for Arsenic Removal from Water: Current Status and Future Perspectives

    Directory of Open Access Journals (Sweden)

    Nina Ricci Nicomel

    2015-12-01

    Full Text Available This review paper presents an overview of the available technologies used nowadays for the removal of arsenic species from water. Conventionally applied techniques to remove arsenic species include oxidation, coagulation-flocculation, and membrane techniques. Besides, progress has recently been made on the utility of various nanoparticles for the remediation of contaminated water. A critical analysis of the most widely investigated nanoparticles is presented and promising future research on novel porous materials, such as metal organic frameworks, is suggested.

  9. Technologies for Arsenic Removal from Water: Current Status and Future Perspectives

    Science.gov (United States)

    Nicomel, Nina Ricci; Leus, Karen; Folens, Karel; Van Der Voort, Pascal; Du Laing, Gijs

    2015-01-01

    This review paper presents an overview of the available technologies used nowadays for the removal of arsenic species from water. Conventionally applied techniques to remove arsenic species include oxidation, coagulation-flocculation, and membrane techniques. Besides, progress has recently been made on the utility of various nanoparticles for the remediation of contaminated water. A critical analysis of the most widely investigated nanoparticles is presented and promising future research on novel porous materials, such as metal organic frameworks, is suggested. PMID:26703687

  10. Alongcoast structure and interannual variability of seasonal midshelf water properties and velocity in the Northern California Current System

    Science.gov (United States)

    Hickey, B.; Geier, S.; Kachel, N.; Ramp, S.; Kosro, P. M.; Connolly, T.

    2016-10-01

    Moored sensors were maintained for ˜5 years on the northern California Current System (CCS) midshelf. The alongcoast sensor array spanned the area of influence of the plume from the Columbia River, several submarine canyons, as well as a coastal promontory where the equatorward coastal jet frequently separates from the shelf. Upwelling-favorable wind stress magnitude decreases poleward by more than a factor of three over the latitudinal range and shelf width varies by a factor of two. In spite of the alongcoast structure in setting, both seasonal and interannual patterns in subsurface layer water properties were remarkably similar at all sites. Higher in the water column, freshwater forcing was substantial. Because of the near surface freshwater input, seasonal sea surface and subsurface temperatures were almost perfectly out of phase in the northernmost CCS, with a mid water column inversion in winter. Year to year differences in subsurface layer wintertime water properties were similar to spatial and temporal patterns of wind stress variability: little alongcoast structure except in salinity, but pronounced interannual differences strongly related to local wind stress. Summertime wind and subsurface property patterns were the opposite of those in winter: pronounced alongcoast wind stress structure, but little or no alongcoast or interannual variability in water properties, and only a weak relationship to local wind stress. Summertime interannual water property variability, including source waters, was shown to be more consistent with "remote forcing" via larger scale wind stress rather than with local wind stress, particularly in the northernmost CCS.

  11. Phytoplankton community structure and nitrogen nutrition in Leeuwin Current and coastal waters off the Gascoyne region of Western Australia

    Science.gov (United States)

    Hanson, Christine E.; Waite, Anya M.; Thompson, Peter A.; Pattiaratchi, Charitha B.

    2007-04-01

    Within the coastal waters of the eastern Indian Ocean adjacent to Western Australia, we tested the hypothesis that regenerated production (and, by inference, the microbial food web) would predominate in oligotrophic Leeuwin Current (LC) and offshore (OS) surface waters. Conversely, we expected that new production would be more important within the ˜5 times more productive shelf countercurrents (Ningaloo and Capes Currents; NC&CC) and the LC&OS deep chlorophyll maximum (DCM). Phytoplankton species composition and abundance were assessed using both light microscopy and chemotaxonomic methods, and isotopic nitrogen uptake experiments ( 15NO 3-, 15NH 4+) were performed at trace (0.05 μM) and saturating (5.0 μM) levels. Phytoplankton community structure was statistically distinct between LC&OS and countercurrent regions. Picoplankton (unicellular cyanobacteria and prochlorophytes) accounted for a mean of 55-65% of pigment biomass in LC&OS waters, with haptophytes as the other primary contributor (21-32%). Conversely, within countercurrent and shelf regions, diatoms (up to 22%) and haptophytes (up to 57%) were more abundant, although cyanobacteria still played an important role (up to 40% of pigment biomass). Absolute NO 3- uptake rates for all samples ranged between 0.5 and 7.1 nmol L -1 h -1, and in countercurrent waters were not significantly different at the surface (3.0±2.1 nmol L -1 h -1; mean±SD) compared to the DCM (2.7±2.3 nmol L -1 h -1). However, in LC&OS waters, rates were significantly lower at the surface (1.2±0.7 nmol L -1 h -1) than the DCM (3.9±2.5 nmol L -1 h -1; p=0.05). These values represent conservative estimates for the region due to methodological difficulties encountered with nitrogen uptake experiments in these oligotrophic waters. In contrast with the distinct community composition between different water types, mean estimates of the f-ratio were similar across sampling depths and water types: 0.17±0.07 at the surface and 0.16±0.06 at

  12. Analysis of projected water availability with current basin management plan, Pajaro Valley, California

    Science.gov (United States)

    Hanson, Randall T.; Lockwood, Brian; Schmid, Wolfgang

    2014-01-01

    The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within “water-balance subregions” (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori.

  13. Current and foreseeable applications of supercritical water for energy and the environment.

    Science.gov (United States)

    Loppinet-Serani, Anne; Aymonier, Cyril; Cansell, François

    2008-01-01

    It is crucial to develop economical and energy-efficient processes for the sustainable transformation of biomass into fuels and chemicals. In this context, supercritical water biomass valorization (SCBV) processes are an alternative way to produce biogas, biofuels, and valuable chemicals. Supercritical water technology has seen much progress over the last fifteen years and an industrial application has merged: the supercritical water oxidation of wastes. The evolution from lab-scale to pilot-scale facilities has provided data on reaction mechanisms, kinetics, modeling, and reactor technology as well as an important know-how, which can now be exploited to use the reactivity in supercritical water to transform biomass into gases (CO, H(2), CO(2), CH(4), and N(2)) or into liquids (liquid fuel and valuable chemicals) with the supercritical water biomass gasification and liquefaction processes, respectively. This Review highlights the potential of SCBV processes to transform biomass into gas and liquid energy sources and highlights the developments that are still necessary to push this technology onto the market.

  14. Determination of aniline in environmental water samples by alternating-current oscillopolarographic titration

    Institute of Scientific and Technical Information of China (English)

    Jun Ping Xiao; Qing Xiang Zhou; Xiao Ke Tian; Hua Hua Bai; Xian Fa Su

    2007-01-01

    A new method for the determination of aniline in environmental water based on oscillopolarographic titration was presented in this paper.Several factors including the kind, concentration, and volume of acid, the dosage of potassium bromide, the temperature and concentration of concomitant substances were investigated in detail.The experimental results indicated that this method was simple, rapid, and sensitive.The linear range was 8.367 x 10-4 to 2.789 x 10-2 mol L-1, the relative standard deviation (R.S.D.) was lower than 0.96%, and the spiked recoveries of aniline in environmental water samples were in the range of 99.4-106.9% under the optimal conditions.The results indicated that the present method could be used as an alternative method for aniline determination in realworld water samples.

  15. [A review on current situations of steroid estrogen in the water system].

    Science.gov (United States)

    Du, Shao-ting; Jin, Chong-wei; Liu, Yue

    2013-09-01

    Steroid estrogens are a group of biologically active endocrine disruptors. An extremely low level of steroid estrogens is sufficient to result in reproduction and behavior disorders, and larval mutation of both human being and animals. The ecological and environmental effects of steroid estrogens should be more direct on organisms in water system as compared with those in other environment systems. Therefore, in this paper we reviewed the physical and chemical properties of some frequently-used steroid estrogens, and their contamination status, origins and transfers in water system, so as to provide a theoretical basis for developing estrogen removal strategies.

  16. The patterns of surface capillary-gravity short-crested waves with uniform current fields in coastal waters

    Institute of Scientific and Technical Information of China (English)

    Hu Huang; Jia Fu

    2006-01-01

    A fully three-dimensional surface gravitycapillary short-crested wave system is studied as two progressive wave-trains of equal amplitude and frequency, which are collinear with uniform currents and doubly-periodic in the horizontal plane, are propagating at an angle to each other. The first-and second-order asymptotic analytical solutions of the short-crested wave system are obtained via a perturbation expansion in a small parameter associated with the wave steepness, therefore depicting a series of typical three-dimensional wave patterns involving currents, shallow and deep water, and surface capillary waves, and comparing them with each other.

  17. Microbial production of multi-carbon chemicals and fuels from water and carbon dioxide using electric current

    Energy Technology Data Exchange (ETDEWEB)

    Lovley, Derek R; Nevin, Kelly

    2015-11-03

    The invention provides systems and methods for generating organic compounds using carbon dioxide as a source of carbon and electrical current as an energy source. In one embodiment, a reaction cell is provided having a cathode electrode and an anode electrode that are connected to a source of electrical power, and which are separated by a permeable membrane. A biological film is provided on the cathode. The biological film comprises a bacterium that can accept electrons and that can convert carbon dioxide to a carbon-bearing compound and water in a cathode half-reaction. At the anode, water is decomposed to free molecular oxygen and solvated protons in an anode half-reaction. The half-reactions are driven by the application of electrical current from an external source. Compounds that have been produced include acetate, butanol, 2-oxobutyrate, propanol, ethanol, and formate.

  18. Poly- and perfluoroalkyl substances (PFASs) in raw and drinking water - current situation in Sweden, Denmark and Germany

    Science.gov (United States)

    Banzhaf, Stefan; Bester, Kai; Filipovic, Marko; Lewis, Jeffrey; Licha, Tobias; Sparrenbom, Charlotte; Barthel, Roland

    2016-04-01

    Poly- and perfluoroalkyl substances (PFASs) are a group of anthropogenic environmental pollutants which have been used and produced for more than 60 years. PFASs are used for multiple industrial purposes, e.g. as water repellent on clothing, leather, and paper and as firefighting foam. The most well studied PFASs subgroup are perfluoroalkyl acids (PFAA). Two PFAAs of particular interest are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). These are the most studied homologues which are ubiquitously detected in the aquatic environment, wildlife and humans. Some PFASs are recognized as being potentially toxic for both animals and humans (e.g. PFOS), whereas the majority has not been thoroughly studied yet regarding their toxicity. PFAAs are highly mobile once present in the aquatic environment. Currently, they are not eliminated during conventional wastewater or drinking water treatment and therefore pose a severe threat for drinking water supply. We reviewed the current occurrence of PFAAs in the surface and groundwater and legal situation of PFAAs in Sweden, Denmark and Germany. Although first detections of PFAAs were reported in the early 2000s, PFASs only recently attracted huge media attention raising public concern. In Sweden, for instance, several public waterworks needed to cease operation due to high PFASs concentrations in drinking water. Moreover, threshold values for drinking water are under discussion and a first preliminary guiding value for PFOS was recently presented as a first step (Pettersson et al., 2015). Germany only defined a guiding value for the sum of PFOS and PFOA in drinking water so far (Dieter, 2011). Limits of 0.3 μg/L PFOA and 0.1 μg/L PFOS and PFOSA each have been suggested in Denmark (MST, 2015). In summary, none of the three countries has defined a clear threshold value for any PFAS compound in drinking water so far. This is of huge concern as PFASs are detected at increasing rates while it remains unclear when

  19. Terrestrial hydro-climatic change, lake shrinkage and water resource deterioration: Analysis of current to future drivers across Asia

    Science.gov (United States)

    Jarsjo, J.; Beygi, H.; Thorslund, J.

    2016-12-01

    Due to overlapping effects of different anthropogenic pressures and natural variability, main drivers behind on-going changes in the water cycle have in many cases not been identified, which complicates management of water resources. For instance, in many parts of the world, and not least in semi-arid and arid parts of Asia, lowered groundwater levels and shrinkage of surface water bodies with associated salinization and water quality deterioration constitute great challenges. With the aim to identify main drivers and mechanisms behind such changes, we here combine (i) historical observations of long-term, large scale change, (ii) ensemble projections of expected future change from the climate models of the Coupled Model Intercomparison Project Phase 5 (CMIP 5) and (iii) output from water balance modelling. Our particular focus is on regions near shrinking lakes. For the principal Lake Urmia in Iran, results show that agricultural intensification including irrigation expansion has clearly contributed to the surprisingly rapid water quality deterioration and lake shrinkage, from 10% lake area reduction in 2002 to the current value of about 75% (leaving billion of tons of salt exposed in its basin). Nevertheless, runoff decrease due to climate change has had an even larger effect. For the Aral Sea in Central Asia, where problems accelerated much earlier (in the 1990's), land-use change and irrigation expansion can fully explain the disastrous surface water deficits and water quality problems in the extensive low-lying parts of the basin. However, projections show that climate-driven runoff decrease in the headwaters of the Aral Sea basin may become a dominant driver of continued change in the near-future. More generally, present results illustrate that mitigation measures that compensate only for land-use driven effects may not reverse current trends of decreasing water availability, due to increasingly strong impacts of climate-driven runoff decrease. This has

  20. Evolutionary algorithms and other metaheuristics in water resources: Current status, research challenges and future directions

    NARCIS (Netherlands)

    Maier, H.R.; Kapelan, Z.; Kasprzyk, J.; Kollat, J.; Matott, L.S.; Cunha, M.C.; Dandy, G.C.; Gibbs, M.S.; Keedwell, E.; Marchi, A.; Ostfeld, A.; Savic, D.; Solomatine, D.P.; Vrugt, J.A.; Zecchin, A.C.; Minsker, B.S.; Barbour, E.J.; Kuczera, G.; Pasha, F.; Castelletti, A.; Giuliani, M.; Reed, P.M.

    2014-01-01

    The development and application of evolutionary algorithms (EAs) and other metaheuristics for the optimisation of water resources systems has been an active research field for over two decades. Research to date has emphasized algorithmic improvements and individual applications in specific areas (e.

  1. Current developments in soil water sensing for climate, environment, hydrology and agriculture

    Science.gov (United States)

    Knowledge of the four dimensional spatio-temporal status and dynamics of soil water content is becoming indispensable to solutions of agricultural, environmental, climatological and engineering problems at all scales. In agronomy alone, science is severely limited by scant or inaccurate knowledge of...

  2. Evaluation of current industry practices for maintaining tomato dump tank water quality during packinghouse operations

    Science.gov (United States)

    In the United States, chlorine is the mainstay disinfectant for produce wash water. In packinghouses, large amounts of accumulating organic matter in dump tanks can cause a dramatic decline in chlorine levels, leaving wash solutions vulnerable to becoming a reservoir for both plant and human pathog...

  3. On water transport in polymer electrolyte membranes during the passage of current

    DEFF Research Database (Denmark)

    Berning, Torsten

    2011-01-01

    This article discusses an approach to model the water transport in the membranes of PEM fuel cells during operation. Starting from a frequently utilized equation the various transport mechanisms are analyzed in detail. It is shown that the commonly used approach to simply balance the electro-osmo...

  4. Evolutionary algorithms and other metaheuristics in water resources: Current status, research challenges and future directions

    NARCIS (Netherlands)

    Maier, H.R.; Kapelan, Z.; Kasprzyk, J.; Kollat, J.; Matott, L.S.; Cunha, M.C.; Dandy, G.C.; Gibbs, M.S.; Keedwell, E.; Marchi, A.; Ostfeld, A.; Savic, D.; Solomatine, D.P.; Vrugt, J.A.; Zecchin, A.C.; Minsker, B.S.; Barbour, E.J.; Kuczera, G.; Pasha, F.; Castelletti, A.; Giuliani, M.; Reed, P.M.

    2014-01-01

    The development and application of evolutionary algorithms (EAs) and other metaheuristics for the optimisation of water resources systems has been an active research field for over two decades. Research to date has emphasized algorithmic improvements and individual applications in specific areas

  5. Water resources research program nearshore currents at Point Beach, Wisconsin (1974--1975)

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, K.D.; Van Loon, L.; Tome, C.; Harrison, W.

    1976-03-01

    Coastal currents of Lake Michigan were monitored at stations 0.4, 1.1, and 3.8 km from shore along a coast-perpendicular transect located 1 km south of the Wisconsin Electric Power Company's nuclear generating station. Complete specifications are given for current meter calibrations, electronics used, winter and summer mooring configurations, and for the performance of each meter and mooring assembly. Local winds were monitored at the power plant intake using a mechanical, MRI wind system. The following types of graphs are presented for current and wind observations: (1) U, V flow components versus time, (2) specific kinetic energy versus time, (3) flow speeds and directions versus time, (4) composite velocity histograms and associated U, V-component histograms, and (5) progressive vector diagrams. A linear, optimal-filter design technique (Wiener filter) is used to estimate the efficiency of wind-driven, linear, nearshore current-prediction models. The poor predictions of the models probably relate to such factors as lack of input for superimposed lake currents, time-base errors, and wind-stress formulas.

  6. A spatial evaluation of historic iron mining impacts on current impaired waters in Lake Superior's Mesabi Range.

    Science.gov (United States)

    Baeten, John; Langston, Nancy; Lafreniere, Don

    2017-10-05

    This paper examines the water quality legacies of historic and current iron mining in the Mesabi Range, the most productive iron range in the history of North America, producing more than 42% of the world's iron ore in the 1950s. Between 1893 and 2016, 3.5 × 10(9) t of iron ore were shipped from the Mesabi Range to steel plants throughout the world. We map historic sites and quantities of iron mining, ore processing, water use, and tailings deposition within subwatershed boundaries. We then map the locations of impaired lakes within HUC-12 subwatershed boundaries within the Mesabi Range, using government datasets created for US federal Clean Water Act reporting. Comparing watersheds with and without historic mining activity, watersheds with historic mining activity currently contain a greater percentage of impaired lakes than control watersheds within the same range. These results suggest that historic iron ore mining and processing in the Mesabi Range affected water quality on a landscape scale, and these legacies persist long after the mines have closed. This paper outlines a novel spatial approach that land managers and policy makers can apply to other landscapes to assess the effects of past mining activity on watershed health.

  7. Dense water cascading, bottom currents and sediment wave formation at the exit of the Bari canyon (Southern Adriatic Sea, Italy)

    Science.gov (United States)

    Langone, Leonardo; Miserocchi, Stefano; Boldrin, Alfredo; Turchetto, Margherita; Foglini, Federica; Trincardi, Fabio

    2010-05-01

    The dense water forming in the North Adriatic (NAdDW) spreading southward along the Italian continental shelf, sinks in the Southern Adriatic basin through particular cascading events. Such events are seasonal, occurring specially in April, with variable intensity. These phenomena control the water mass mixing, the deep ocean ventilation, the behaviour of deep ecosystems, the formation of complex erosive and depositional bedforms and the abyssal export and burial of nutrients and carbon. Because of the NadDW formation is linked to climate factors (frequency, duration and size of Bura winds), the temporal variations of the NadDW dispersion into the Southern Adriatic allow to make inferences of the impact of recent climate changes on the ecosystems of the deep Mediterranean Sea. Previous research projects (EuroStrataform, HERMES) acquired a large data set of bathymetric, side-scan sonar (TOBI) and Chirp sonar profiles, which were used to build detailed morpho-bathymetric maps of the Southern Adriatic margin. There, the seabed is extremely complex, characterized by a large variety of bedforms (sediment waves, erosive scours, longitudinal furrows and giant comet marks). A branch of the cascading NAdDW is confined and accelerated through the Bari canyon where it produces a strong current capable of reaching down-slope velocities greater than 60 cm s-1 near the bottom at ~600 m of water depth, eroding the canyon thalweg and entraining large amounts of fine-grained sediment. At the exit of the canyon, in water depth greater than 800 m, the current becomes less confined, spreads laterally and generates an 80-km2-wide field of mud waves; these bedforms migrate up current and show amplitudes up to 50 m and wavelengths of about 1 km. Cruise IMPACT-09 of RV Urania was carried out in the Southern Adriatic Sea from 17-30 March 2009 with main scope of studying the impact of NadDW cascading events on the deep ecosystems of the Southern Adriatic. Experiments planned in the cruise

  8. Current trends in water-in-diesel emulsion as a fuel.

    Science.gov (United States)

    Yahaya Khan, Mohammed; Abdul Karim, Z A; Hagos, Ftwi Yohaness; Aziz, A Rashid A; Tan, Isa M

    2014-01-01

    Water-in-diesel emulsion (WiDE) is an alternative fuel for CI engines that can be employed with the existing engine setup with no additional engine retrofitting. It has benefits of simultaneous reduction of both NO x and particulate matters in addition to its impact in the combustion efficiency improvement, although this needs further investigation. This review paper addresses the type of emulsion, the microexplosion phenomenon, emulsion stability and physiochemical improvement, and effect of water content on the combustion and emissions of WiDE fuel. The review also covers the recent experimental methodologies used in the investigation of WiDE for both transport and stationary engine applications. In this review, the fuel injection pump and spray nozzle arrangement has been found to be the most critical components as far as the secondary atomization is concerned and further investigation of the effect of these components in the microexplosion of the emulsion is suggested to be center of focus.

  9. Current Trends in Water-in-Diesel Emulsion as a Fuel

    Science.gov (United States)

    Yahaya Khan, Mohammed; Abdul Karim, Z. A.; Aziz, A. Rashid A.; Tan, Isa M.

    2014-01-01

    Water-in-diesel emulsion (WiDE) is an alternative fuel for CI engines that can be employed with the existing engine setup with no additional engine retrofitting. It has benefits of simultaneous reduction of both NOx and particulate matters in addition to its impact in the combustion efficiency improvement, although this needs further investigation. This review paper addresses the type of emulsion, the microexplosion phenomenon, emulsion stability and physiochemical improvement, and effect of water content on the combustion and emissions of WiDE fuel. The review also covers the recent experimental methodologies used in the investigation of WiDE for both transport and stationary engine applications. In this review, the fuel injection pump and spray nozzle arrangement has been found to be the most critical components as far as the secondary atomization is concerned and further investigation of the effect of these components in the microexplosion of the emulsion is suggested to be center of focus. PMID:24563631

  10. Current Trends in Water-in-Diesel Emulsion as a Fuel

    Directory of Open Access Journals (Sweden)

    Mohammed Yahaya Khan

    2014-01-01

    Full Text Available Water-in-diesel emulsion (WiDE is an alternative fuel for CI engines that can be employed with the existing engine setup with no additional engine retrofitting. It has benefits of simultaneous reduction of both NOx and particulate matters in addition to its impact in the combustion efficiency improvement, although this needs further investigation. This review paper addresses the type of emulsion, the microexplosion phenomenon, emulsion stability and physiochemical improvement, and effect of water content on the combustion and emissions of WiDE fuel. The review also covers the recent experimental methodologies used in the investigation of WiDE for both transport and stationary engine applications. In this review, the fuel injection pump and spray nozzle arrangement has been found to be the most critical components as far as the secondary atomization is concerned and further investigation of the effect of these components in the microexplosion of the emulsion is suggested to be center of focus.

  11. Current practice and guidelines for the safe design of water barrier pillars

    CSIR Research Space (South Africa)

    Rangasamy, T

    2001-08-01

    Full Text Available 5.5 Conclusions.............................................................................................................................48 6 Ground penetrating radar scan .............................................49 7 Effect of water quality... as well as pillar-roof/floor interfaces. In the following sections various empirical techniques, which have been employed around the globe, are presented and discussed. 2.1.1.2 North America 2.1.1.2.1 Legislation The Federal Coal Mine Safety Act...

  12. Behaviour of bipolar membranes at high current density. Water diffusion limitation

    NARCIS (Netherlands)

    Krol, J.J.; Jansink, M.G.J.; Wessling, Matthias; Strathmann, H.

    1998-01-01

    In this paper the behaviour of bipolar membranes at very high current density is discussed. Current–voltage curves are determined, both for the Tokuyama Soda BP-1 and the WSI Technologies bipolar membrane. The current–voltage curves are characterised by an inflection point at which a drastic

  13. Growth of a deep-water, predatory fish is influenced by the productivity of a boundary current system.

    Science.gov (United States)

    Nguyen, Hoang Minh; Rountrey, Adam N; Meeuwig, Jessica J; Coulson, Peter G; Feng, Ming; Newman, Stephen J; Waite, Anya M; Wakefield, Corey B; Meekan, Mark G

    2015-03-12

    The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the otolith chronology was positively correlated (r = 0.61, p < 0.02) with sea level at Fremantle, a proxy for the strength of the Leeuwin Current. The Leeuwin Current influences the primary productivity of shelf ecosystems, with a strong current favouring growth in hapuku. Leeuwin Current strength is predicted to decline under climate change models and this study provides evidence that associated productivity changes may flow through to higher trophic levels even in deep water habitats.

  14. Extending to seasonal scales the current usage of short range weather forecasts and climate projections for water management in Spain

    Science.gov (United States)

    Rodriguez-Camino, Ernesto; Voces, José; Sánchez, Eroteida; Navascues, Beatriz; Pouget, Laurent; Roldan, Tamara; Gómez, Manuel; Cabello, Angels; Comas, Pau; Pastor, Fernando; Concepción García-Gómez, M.°; José Gil, Juan; Gil, Delfina; Galván, Rogelio; Solera, Abel

    2016-04-01

    This presentation, first, briefly describes the current use of weather forecasts and climate projections delivered by AEMET for water management in Spain. The potential use of seasonal climate predictions for water -in particular dams- management is then discussed more in-depth, using a pilot experience carried out by a multidisciplinary group coordinated by AEMET and DG for Water of Spain. This initiative is being developed in the framework of the national implementation of the GFCS and the European project, EUPORIAS. Among the main components of this experience there are meteorological and hydrological observations, and an empirical seasonal forecasting technique that provides an ensemble of water reservoir inflows. These forecasted inflows feed a prediction model for the dam state that has been adapted for this purpose. The full system is being tested retrospectively, over several decades, for selected water reservoirs located in different Spanish river basins. The assessment includes an objective verification of the probabilistic seasonal forecasts using standard metrics, and the evaluation of the potential social and economic benefits, with special attention to drought and flooding conditions. The methodology of implementation of these seasonal predictions in the decision making process is being developed in close collaboration with final users participating in this pilot experience.

  15. Water physics and chemistry data from moored current meter and bottle casts in the Coastal Waters of New Jersey as part of the Mesa New York Bight (MESA - NYB) project, 27 August 1973 - 27 November 1974 (NODC Accession 7600777)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Coastal Waters of New Jersey from August 27, 1973 to November 7,...

  16. Water physics and chemistry data from moored current meter and bottle casts in the Coastal Waters of New Jersey as part of the Mesa New York Bight (MESA - NYB) project, 21 May 1963 - 08 July 1975 (NODC Accession 7601561)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Coastal Waters of New Jersey from May 21, 1963 to July 8, 1975....

  17. Water physics and chemistry data from moored current meter and bottle casts in the Coastal Waters of New Jersey as part of the Mesa New York Bight (MESA - NYB) project, 08 March 1974 - 13 May 1974 (NODC Accession 7501210)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Coastal Waters of New Jersey from March 8, 1974 to May 13, 1974....

  18. Water physics and chemistry data from moored current meter and bottle casts in the Coastal Waters of New Jersey as part of the Mesa New York Bight (MESA - NYB) project, 05 November 1973 to 06 June 1974 (NODC Accession 7500931)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Coastal Waters of New Jersey from November 5, 1973 to June 6,...

  19. Water physics and chemistry data from moored current meter and bottle casts in the Coastal Waters of New Jersey as part of the Mesa New York Bight (MESA - NYB) project, 10 April 1978 - 09 August 1978 (NODC Accession 7900249)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Coastal Waters of New Jersey from April 10, 1978 to August 9,...

  20. Water physics and chemistry data from moored current meter and bottle casts in the Coastal Waters of New Jersey as part of the Mesa New York Bight (MESA - NYB) project from 12 April 1976 - 13 September 1976 (NODC Accession 7700770)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Coastal Waters of New Jersey from April 12, 1976 to September 13,...

  1. Water physics and chemistry data from moored current meter and bottle casts in the Coastal Waters of New Jersey as part of the Mesa New York Bight (MESA - NYB) project, 09 April 1979 - 23 August 1979 (NODC Accession 8100440)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Coastal Waters of New Jersey from April 9, 1979 to August 23,...

  2. Detecting and monitoring of water inrush in tunnels and coal mines using direct current resistivity method:A review

    Institute of Scientific and Technical Information of China (English)

    Shucai Li; Bin Liu; Lichao Nie; Zhengyu Liu; Mingzhen Tian; Shirui Wang; Maoxin Su; Qian Guo

    2015-01-01

    Detecting, real-time monitoring and early warning of underground water-bearing structures are critically important issues in prevention and mitigation of water inrush hazards in underground engineering. Direct current (DC) resistivity method is a widely used method for routine detection, advanced detection and real-time monitoring of water-bearing structures, due to its high sensitivity to groundwater. In this study, the DC resistivity method applied to underground engineering is reviewed and discussed, including the observation mode, multiple inversions, and real-time monitoring. It is shown that a priori information constrained inversion is desirable to reduce the non-uniqueness of inversion, with which the accuracy of detection can be significantly improved. The focused resistivity method is prospective for advanced detection;with this method, the flanking interference can be reduced and the detection dis-tance is increased subsequently. The time-lapse resistivity inversion method is suitable for the regions with continuous conductivity changes, and it can be used to monitor water inrush in those regions. Based on above-mentioned features of various methods in terms of benefits and limitations, we propose a three-dimensional (3D) induced polarization method characterized with multi-electrode array, and introduce it into tunnels and mines combining with real-time monitoring with time-lapse inversion and cross-hole resistivity method. At last, the prospective applications of DC resistivity method are discussed as follows: (1) available advanced detection technology and instrument in tunnel excavated by tunnel boring machine (TBM), (2) high-resolution detection method in holes, (3) four-dimensional (4D) monitoring technology for water inrush sources, and (4) estimation of water volume in water-bearing structures.

  3. Detecting and monitoring of water inrush in tunnels and coal mines using direct current resistivity method: A review

    Directory of Open Access Journals (Sweden)

    Shucai Li

    2015-08-01

    Full Text Available Detecting, real-time monitoring and early warning of underground water-bearing structures are critically important issues in prevention and mitigation of water inrush hazards in underground engineering. Direct current (DC resistivity method is a widely used method for routine detection, advanced detection and real-time monitoring of water-bearing structures, due to its high sensitivity to groundwater. In this study, the DC resistivity method applied to underground engineering is reviewed and discussed, including the observation mode, multiple inversions, and real-time monitoring. It is shown that a priori information constrained inversion is desirable to reduce the non-uniqueness of inversion, with which the accuracy of detection can be significantly improved. The focused resistivity method is prospective for advanced detection; with this method, the flanking interference can be reduced and the detection distance is increased subsequently. The time-lapse resistivity inversion method is suitable for the regions with continuous conductivity changes, and it can be used to monitor water inrush in those regions. Based on above-mentioned features of various methods in terms of benefits and limitations, we propose a three-dimensional (3D induced polarization method characterized with multi-electrode array, and introduce it into tunnels and mines combining with real-time monitoring with time-lapse inversion and cross-hole resistivity method. At last, the prospective applications of DC resistivity method are discussed as follows: (1 available advanced detection technology and instrument in tunnel excavated by tunnel boring machine (TBM, (2 high-resolution detection method in holes, (3 four-dimensional (4D monitoring technology for water inrush sources, and (4 estimation of water volume in water-bearing structures.

  4. Sources, fate, and pathways of Leeuwin Current water in the Indian Ocean and Great Australian Bight : A Lagrangian study in an eddy-resolving ocean model

    NARCIS (Netherlands)

    Yit Sen Bull, Christopher; Van Sebille, Erik

    2016-01-01

    The Leeuwin Current is the dominant circulation feature in the eastern Indian Ocean, transporting tropical and subtropical water southward. While it is known that the Leeuwin Current draws its water from a multitude of sources, existing Indian Ocean circulation schematics have never quantified the

  5. Current-use flame retardants in the water of Lake Michigan tributaries

    Science.gov (United States)

    Guo, Jiehong; Romanak, Kevin; Westenbroek, Stephen M.; Hites, Ronald A.; Venier, Marta

    2017-01-01

    In this study, we measured the concentrations of 65 flame retardants in water samples from five Lake Michigan tributaries. These flame retardants included organophosphate esters (OPEs), brominated flame retardants (BFRs), and Dechlorane-related compounds. A total of 59 samples, including both the particulate and the dissolved phases, were collected from the Grand, Kalamazoo, Saint Joseph, and Lower Fox rivers and from the Indiana Harbor and Ship Canal (IHSC) in 2015. OPEs were the most abundant among the targeted compounds with geometric mean concentrations ranging from 20 to 54 ng/L; OPE concentrations were comparable among the five tributaries. BFR concentrations were about 1 ng/L, and the most-abundant compounds were bis(2-ethylhexyl) tetrabromophthalate, 2-ethylhexyl 2,3,4,5-tetrabromobenzoate, and decabromodiphenyl ether. The highest BFR concentrations were measured in either the IHSC or the Saint Joseph River. The dechlorane-related compounds were detected at low concentrations (increase with their octanol–water partition coefficient. The chemical loading from all the five tributaries into Lake Michigan were <10 kg/year for the BFRs and about 500 kg/year for the OPEs.

  6. The influence of Pacific Equatorial Water on fish diversity in the southern California Current System

    Science.gov (United States)

    McClatchie, Sam; Thompson, Andrew R.; Alin, Simone R.; Siedlecki, Samantha; Watson, William; Bograd, Steven J.

    2016-08-01

    The California Undercurrent transports Pacific Equatorial Water (PEW) into the Southern California Bight from the eastern tropical Pacific Ocean. PEW is characterized by higher temperatures and salinities, with lower pH, representing a source of potentially corrosive (aragonite,Ωfish diversity. We use hydrographic data to characterize the interannual and seasonal variability of estimated pH and aragonite saturation with depth. Although there is substantial variability in PEW presence as measured by spice on the 26.25-26.75 isopycnal layer, as well as in pH and aragonite saturation, we found fish diversity to be stable over the decades 1985-1996 and 1999-2011. We detected significant difference in species structure during the 1998 La Niña period, due to reduced species evenness. Species richness due to rare species was higher during the 1997/1998 El Niño compared to the La Niña but the effect on species structure was undetectable. Lack of difference in the species abundance structure in the decade before and after the 1997/1999 ENSO event showed that the assemblage reverted to its former structure following the ENSO perturbation, indicating resilience. While the interdecadal species structure remained stable, the long tail of the distributions shows that species richness increased between the decades consistent with intrusion of warm water with more diverse assemblages into the southern California region.

  7. Influence of wave and current flow on sediment-carrying capacity and sediment flux at the water-sediment interface.

    Science.gov (United States)

    Zheng, Jun; Li, Ruijie; Yu, Yonghai; Suo, Anning

    2014-01-01

    In nearshore waters, spatial and temporal scales of waves, tidal currents, and circulation patterns vary greatly. It is, therefore, difficult to combine these factors' effects when trying to predict sediment transport processes. This paper proposes the concept of significant wave velocity, which combines the effects of waves, tides, and ocean currents using the horizontal kinetic energy superposition principle. Through a comparison of the relationship between shear stress at the water-sediment interface and sediment-carrying capacity, assuming equilibrium sediment flux, a new formula for sediment-carrying capacity, which incorporates the concept of significant wave velocities, is derived. Sediment-carrying capacity is a function of the critical velocity, which increases with water depth and decreases with increasing relative roughness of the sea bed. Finally, data from field observation stations and simulations are used to test the proposed formula. The results show that the new formula is in good agreement with both field and simulation data. This new formula for sediment-carrying capacity can be used to simulate nearshore sediment transport.

  8. Water Level and Current Simulation for LOTS Operations - Persian Gulf and Gulf of Oman

    Science.gov (United States)

    1994-07-01

    equations are solved by a finite element approach. However the equations are reformulated mathematically to a form with much improved numerical solution...longer than the tidal cycle, since tidal ebb and flood currents tend to cancel each other. 23Chqpwr 3 Ceibraga wnd Vedication 30 25 (Z 20 M2 "W 15 0 10Q...circulation in the Arabian Gulf," Applied Mathematical Modeling, 14, 410-419. Bogdanov, K. T. (1987). "T’idal wave propagation and tidal level oscillations

  9. CURRENT STATE OF WATER BIORESOURCES OF THE VOLGA AND CASPIAN SEA BASIN

    Directory of Open Access Journals (Sweden)

    L. M. Vasileva

    2012-01-01

    Full Text Available The article considers the issues of current degraded state of aquatic biological resources of the Volga-Caspian Sea basin and provides specific data on commercial stocks of fish. The main reasons for decrease in natural stocks of ichthyofauna are regulation and pollution of the spawning rivers, adverse hydrological conditions, injudicious hunting, poaching pressure. To improve the state of natural stocks of fish it is necessary to increase their reproduction and implement measures to restore and rational exploitation of aquatic bioresources of the Volga- Caspian Sea basin.

  10. A comparative analysis of current microbial water quality risk assessment and management practices in British Columbia and Ontario, Canada.

    Science.gov (United States)

    Dunn, Gemma; Harris, Leila; Cook, Christina; Prystajecky, Natalie

    2014-01-15

    Bacteria, protozoa and viruses are ubiquitous in aquatic environments and may pose threats to water quality for both human and ecosystem health. Microbial risk assessment and management in the water sector is a focus of governmental regulation and scientific inquiry; however, stark gaps remain in their application and interpretation. This paper evaluates how water managers practice microbial risk assessment and management in two Canadian provinces (BC and Ontario). We assess three types of entities engaged in water management along the source-to-tap spectrum (watershed agencies, water utilities, and public health authorities). We analyze and compare the approaches used by these agencies to assess and manage microbial risk (including scope, frequency, and tools). We evaluate key similarities and differences, and situate them with respect to international best practices derived from literatures related to microbial risk assessment and management. We find considerable variability in microbial risk assessment frameworks and management tools in that approaches 1) vary between provinces; 2) vary within provinces and between similar types of agencies; 3) have limited focus on microbial risk assessment for ecosystem health and 4) diverge considerably from the literature on best practices. We find that risk assessments that are formalized, routine and applied system-wide (i.e. from source-to-tap) are limited. We identify key limitations of current testing methodologies and looking forward consider the outcomes of this research within the context of new developments in microbial water quality monitoring such as tests derived from genomics and metagenomics based research. © 2013 Elsevier B.V. All rights reserved.

  11. Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health

    Science.gov (United States)

    Lapworth, D. J.; Nkhuwa, D. C. W.; Okotto-Okotto, J.; Pedley, S.; Stuart, M. E.; Tijani, M. N.; Wright, J.

    2017-01-01

    Groundwater resources are important sources of drinking water in Africa, and they are hugely important in sustaining urban livelihoods and supporting a diverse range of commercial and agricultural activities. Groundwater has an important role in improving health in sub-Saharan Africa (SSA). An estimated 250 million people (40% of the total) live in urban centres across SSA. SSA has experienced a rapid expansion in urban populations since the 1950s, with increased population densities as well as expanding geographical coverage. Estimates suggest that the urban population in SSA will double between 2000 and 2030. The quality status of shallow urban groundwater resources is often very poor due to inadequate waste management and source protection, and poses a significant health risk to users, while deeper borehole sources often provide an important source of good quality drinking water. Given the growth in future demand from this finite resource, as well as potential changes in future climate in this region, a detailed understanding of both water quantity and quality is required to use this resource sustainably. This paper provides a comprehensive assessment of the water quality status, both microbial and chemical, of urban groundwater in SSA across a range of hydrogeological terrains and different groundwater point types. Lower storage basement terrains, which underlie a significant proportion of urban centres in SSA, are particularly vulnerable to contamination. The relationship between mean nitrate concentration and intrinsic aquifer pollution risk is assessed for urban centres across SSA. Current knowledge gaps are identified and future research needs highlighted.

  12. Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health

    Science.gov (United States)

    Lapworth, D. J.; Nkhuwa, D. C. W.; Okotto-Okotto, J.; Pedley, S.; Stuart, M. E.; Tijani, M. N.; Wright, J.

    2017-06-01

    Groundwater resources are important sources of drinking water in Africa, and they are hugely important in sustaining urban livelihoods and supporting a diverse range of commercial and agricultural activities. Groundwater has an important role in improving health in sub-Saharan Africa (SSA). An estimated 250 million people (40% of the total) live in urban centres across SSA. SSA has experienced a rapid expansion in urban populations since the 1950s, with increased population densities as well as expanding geographical coverage. Estimates suggest that the urban population in SSA will double between 2000 and 2030. The quality status of shallow urban groundwater resources is often very poor due to inadequate waste management and source protection, and poses a significant health risk to users, while deeper borehole sources often provide an important source of good quality drinking water. Given the growth in future demand from this finite resource, as well as potential changes in future climate in this region, a detailed understanding of both water quantity and quality is required to use this resource sustainably. This paper provides a comprehensive assessment of the water quality status, both microbial and chemical, of urban groundwater in SSA across a range of hydrogeological terrains and different groundwater point types. Lower storage basement terrains, which underlie a significant proportion of urban centres in SSA, are particularly vulnerable to contamination. The relationship between mean nitrate concentration and intrinsic aquifer pollution risk is assessed for urban centres across SSA. Current knowledge gaps are identified and future research needs highlighted.

  13. Assessment of Current Inservice Inspection and Leak Monitoring Practices for Detecting Materials Degradation in Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Michael T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Simonen, Fredric A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Muscara, Joseph [US Nuclear Regulatory Commission (NRC), Rockville, MD (United States); Doctor, Steven R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kupperman, David S. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-09-01

    An assessment was performed to determine the effectiveness of existing inservice inspection (ISI) and leak monitoring techniques, and recommend improvements, as necessary, to the programs as currently performed for light water reactor (LWR) components. Information from nuclear power plant (NPP) aging studies and from the U. S. Nuclear Regulatory Commission’s Generic Aging Lessons Learned (GALL) report (NUREG-1801) was used to identify components that have already experienced, or are expected to experience, degradation. This report provides a discussion of the key aspects and parameters that constitute an effective ISI program and a discussion of the basis and background against which the effectiveness of the ISI and leak monitoring programs for timely detection of degradation was evaluated. Tables based on the GALL components were used to systematically guide the process, and table columns were included that contained the ISI requirements and effectiveness assessment. The information in the tables was analyzed using histograms to reduce the data and help identify any trends. The analysis shows that the overall effectiveness of the ISI programs is very similar for both boiling water reactors (BWRs) and pressurized water reactors (PWRs). The evaluations conducted as part of this research showed that many ISI programs are not effective at detecting degradation before its extent reached 75% of the component wall thickness. This work should be considered as an assessment of NDE practices at this time; however, industry and regulatory activities are currently underway that will impact future effectiveness assessments. A number of actions have been identified to improve the current ISI programs so that degradation can be more reliably detected.

  14. Controversies in the Hydrosphere: an iBook exploring current global water issues for middle school classrooms

    Science.gov (United States)

    Dufoe, A.; Guertin, L. A.

    2012-12-01

    This project looks to help teachers utilize iPad technology in their classrooms as an instructional tool for Earth system science and connections to the Big Ideas in Earth Science. The project is part of Penn State University's National Science Foundation (NSF) Targeted Math Science Partnership grant, with one goal of the grant to help current middle school teachers across Pennsylvania engage students with significant and complex questions of Earth science. The free Apple software iBooks Author was used to create an electronic book for the iPad, focusing on a variety of controversial issues impacting the hydrosphere. The iBook includes image slideshows, embedded videos, interactive images and quizzes, and critical thinking questions along Bloom's Taxonomic Scale of Learning Objectives. Outlined in the introductory iBook chapters are the Big Ideas of Earth System Science and an overview of Earth's spheres. Since the book targets the hydrosphere, each subsequent chapter focuses on specific water issues, including glacial melts, aquifer depletion, coastal oil pollution, marine debris, and fresh-water chemical contamination. Each chapter is presented in a case study format that highlights the history of the issue, the development and current status of the issue, and some solutions that have been generated. The next section includes critical thinking questions in an open-ended discussion format that focus on the Big Ideas, proposing solutions for rectifying the situation, and/or assignments specifically targeting an idea presented in the case study chapter. Short, comprehensive multiple-choice quizzes are also in each chapter. Throughout the iBook, students are free to watch videos, explore the content and form their own opinions. As a result, this iBook fulfills the grant objective by engaging teachers and students with an innovative technological presentation that incorporates Earth system science with current case studies regarding global water issues.

  15. Historic, Current, and Future Availability of Surface Water for Agricultural Groundwater Banking in the Central Valley, California

    Science.gov (United States)

    Kocis, T. N.; Dahlke, H. E.

    2015-12-01

    Groundwater banking, the intentional recharge of groundwater from surface water for storage and recovery, is an important conjunctive use strategy for water management in California. A largely unexplored approach to groundwater banking, agricultural groundwater banking (ag-GB), utilizes flood flows and agricultural lands for recharging groundwater. Understanding the availability of excess streamflow (e.g., the magnitude, frequency, timing, and duration of winter flood flows) is fundamental to assessing the feasibility of local-scale implementation of ag-GB. In this study, we estimate the current availability and forecast the future availability of winter (Nov to Apr) flood flows based on current and historic daily streamflow records for 200 stream gauges on tributaries to and streams within the Central Valley, California. For each gauge, we consider flows above a stationary 90th percentile as ideal for ag-GB because reservoir operations mitigate flood risk by releasing early winter flood flows. Results based on 70 years of data show that for 25% of the gauges there are significantly decreasing flow volumes above the 90th percentile and a decreasing number of days with flows above the 90th percentile. These flows, on average, make up 20% of the total annual winter flows. The majority of gauges further show, over the past 70 years, a decrease in total annual streamflow magnitude, a decrease in the magnitude of extreme flood events, and an increase in the frequency of flood events. Variations in winter flood flows due to climate change and climate variability are a challenge to water management in California. To aid the long-term forecast of streamflow conditions in California, we present a new water year type index for the Central Valley, which considers the variation in flow percentiles over time. Together, our results suggest that flexible, coordinated efforts for the local diversion of flood flows are needed to better utilize the increasingly rare winter flood

  16. Effects of transient bottom water currents and oxygen concentrations on benthic exchange rates as assessed by eddy correlation measurements

    Science.gov (United States)

    Holtappels, Moritz; Glud, Ronnie N.; Donis, Daphne; Liu, Bo; Hume, Andrew; WenzhöFer, Frank; Kuypers, Marcel M. M.

    2013-03-01

    correlation (EC) measurements in the benthic boundary layer (BBL) allow estimating benthic O2 uptake from a point distant to the sediment surface. This noninvasive approach has clear advantages as it does not disturb natural hydrodynamic conditions, integrates the flux over a large foot-print area and allows many repetitive flux measurements. A drawback is, however, that the measured flux in the bottom water is not necessarily equal to the flux across the sediment-water interface. A fundamental assumption of the EC technique is that mean current velocities and mean O2 concentrations in the bottom water are in steady state, which is seldom the case in highly dynamic environments like coastal waters. Therefore, it is of great importance to estimate the error introduced by nonsteady state conditions. We investigated two cases of transient conditions. First, the case of transient O2 concentrations was examined using the theory of shear flow dispersion. A theoretical relationship between the change of O2 concentrations and the induced vertical O2 flux is introduced and applied to field measurements showing that changes of 5-10 μM O2 h-1 result in transient EC-fluxes of 6-12 mmol O2 m-2 d-1, which is comparable to the O2 uptake of shelf sediments. Second, the case of transient velocities was examined with a 2D k-ɛ turbulence model demonstrating that the vertical flux can be biased by 30-100% for several hours during changing current velocities from 2 to 10 cm s-1. Results are compared to field measurements and possible ways to analyze and correct EC-flux estimates are discussed.

  17. Extraction of water and solutes from argillaceous rocks for geochemical characterisation: Methods, processes and current understanding

    Science.gov (United States)

    Sacchi, Elisa; Michelot, Jean-Luc; Pitsch, Helmut; Lalieux, Philippe; Aranyossy, Jean-François

    2001-01-01

    This paper summarises the results of a comprehensive critical review, initiated by the OECD/NEA "Clay Club," of the extraction techniques available to obtain water and solutes from argillaceous rocks. The paper focuses on the mechanisms involved in the extraction processes, the consequences on the isotopic and chemical composition of the extracted pore water and the attempts made to reconstruct its original composition. Finally, it provides some examples of reliable techniques and information, as a function of the purpose of the geochemical study. Résumé. Cet article résume les résultats d'une synthèse critique d'ensemble, lancée par le OECD/NEA "Clay Club", sur les techniques d'extraction disponibles pour obtenir l'eau et les solutés de roches argileuses. L'article est consacré aux mécanismes impliqués dans les processus d'extraction, aux conséquences sur la composition isotopique et chimique de l'eau porale extraite et aux tentatives faites pour reconstituer sa composition originelle. Finalement, il donne quelques exemples de techniques fiables et d'informations, en fonction du but de l'étude géochimique. Resúmen. Este artículo resume los resultados de una revisión crítica exhaustiva (iniciada por el "Clay Club" OECD/NEA) de las técnicas de extracción disponibles para obtener agua y solutos en rocas arcillosas. El artículo se centra en los mecanismos involucrados en los procesos extractivos, las consecuencias en la composición isotópica y química del agua intersticial extraída, y en los intentos realizados para reconstruir su composición original. Finalmente, se presentan algunos ejemplos de técnicas fiables e información, en función del propósito del estudio geoquímico.

  18. Marine parasites as biological tags in South American Atlantic waters, current status and perspectives.

    Science.gov (United States)

    Cantatore, D M P; Timi, J T

    2015-01-01

    Many marine fisheries in South American Atlantic coasts (SAAC) are threatened by overfishing and under serious risk of collapsing. The SAAC comprises a diversity of environments, possesses a complex oceanography and harbours a vast biodiversity that provide an enormous potential for using parasites as biological tags for fish stock delineation, a prerequisite for the implementation of control and management plans. Here, their use in the SAAC is reviewed. Main evidence is derived from northern Argentine waters, where fish parasite assemblages are dominated by larval helminth species that share a low specificity, long persistence and trophic transmission, parasitizing almost indiscriminately all available fish species. The advantages and constraints of such a combination of characteristics are analysed and recommendations are given for future research. Shifting the focus from fish/parasite populations to communities allows expanding the concept of biological tags from local to regional scales, providing essential information to delineate ecosystem boundaries for host communities. This new concept arose as a powerful tool to help the implementation of ecosystem-based approaches to fisheries management, the new paradigm for fisheries science. Holistic approaches, including parasites as biological tags for stock delineation will render valuable information to help insure fisheries and marine ecosystems against further depletion and collapse.

  19. Water Waves from General, Time-Dependent Surface Pressure Distribution in the Presence of a Shear Current

    CERN Document Server

    Li, Yan

    2015-01-01

    We obtain a general solution for the water waves resulting from a general, time-dependent surface pressure distribution, in the presence of a shear current of uniform vorticity beneath the surface, in three dimensions. Linearized governing equations and boundary conditions including the effects of gravity, a distributed external pressure disturbance, and constant finite depth, are solved analytically, and particular attention is paid to classic initial value problems: an initial pressure impulse and a steady pressure distribution which appears suddenly. In the present paper, good agreement with previous results is demonstrated. We subsequently show both analytically and numerically how transient waves from a suddenly appearing steady pressure distribution vanis for large times, and steady ship waves remain. The transient contribution to wave resistance was derived. The results show that a shear current has significant impact on the transient wave motions, resulting in asymmetry between upstream and downstream...

  20. Photoelectrolysis of water at high current density - Use of ultraviolet laser excitation

    Science.gov (United States)

    Bocarsly, A. B.; Bolts, J. M.; Cummins, P. G.; Wrighton, M. S.

    1977-01-01

    The behavior of TiO2 and SrTiO3 photoanodes in cells for the photoelectrolysis of H2O has been investigated for high-intensity 351-,364-nm excitation from an Ar ion laser. Intensities up to 380 W/sq cm have been used. For TiO2 a small amount of surface decomposition is found after irradiation at high intensity, whereas SrTiO3 undergoes no detectable changes. Current-voltage properties for both electrodes are essentially independent of light intensity up to the level of 380 W/sq cm, and there is little if any change in quantum efficiency for electron flow. Photocurrent densities have been shown to exceed 5 A/sq cm for O2 evolution. Data show that the energy storage rate associated with the SrTiO3 photoelectrolysis can exceed 30 W/sq cm; this represents the highest demonstrated rate of sustained optical-to-chemical energy conversion.

  1. Optimum structural properties for an anode current collector used in a polymer electrolyte membrane water electrolyzer operated at the boiling point of water

    Science.gov (United States)

    Li, Hua; Fujigaya, Tsuyohiko; Nakajima, Hironori; Inada, Akiko; Ito, Kohei

    2016-11-01

    This study attempts to optimize the properties of the anode current collector of a polymer electrolyte membrane water electrolyzer at high temperatures, particularly at the boiling point of water. Different titanium meshes (4 commercial ones and 4 modified ones) with various properties are experimentally examined by operating a cell with each mesh under different conditions. The average pore diameter, thickness, and contact angle of the anode current collector are controlled in the ranges of 10-35 μm, 0.2-0.3 mm, and 0-120°, respectively. These results showed that increasing the temperature from the conventional temperature of 80 °C to the boiling point could reduce both the open circuit voltage and the overvoltages to a large extent without notable dehydration of the membrane. These results also showed that decreasing the contact angle and the thickness suppresses the electrolysis overvoltage largely by decreasing the concentration overvoltage. The effect of the average pore diameter was not evident until the temperature reached the boiling point. Using operating conditions of 100 °C and 2 A/cm2, the electrolysis voltage is minimized to 1.69 V with a hydrophilic titanium mesh with an average pore diameter of 21 μm and a thickness of 0.2 mm.

  2. Distribution of a pelagic tunicate, Salpa fusiformis in warm surface current of the eastern Korean waters and its impingement on cooling water intakes of Uljin nuclear power plant.

    Science.gov (United States)

    Chae, Jinho; Choi, Hyun Woo; Lee, Woo Jin; Kim, Dongsung; Lee, Jae Hac

    2008-07-01

    Impingement of a large amount of gelatinous plankton, Salpa fusiformis on the seawater intake system-screens in a nuclear power plant at Uljin was firstly recorded on 18th June 2003. Whole amount of the clogged animals was estimated were presumptively at 295 tons and the shortage of cooling seawater supply by the animal clogging caused 38% of decrease in generation capability of the power plant. Zooplankton collection with a multiple towing net during the day and at night from 5 to 6 June 2003 included various gelatinous zooplanktons known to be warm water species such as salps and siphonophores. Comparatively larger species, Salpa fusiformis occupied 25.4% in individual density among the gelatinous plankton and showed surface distribution in the depth shallower than thermocline, performing little diel vertical migration. Temperature, salinity and satellite data also showed warm surface current predominated over the southern coastal region near the power plant in June. The results suggested that warm surface current occasionally extended into the neritic region may transfer S. fusiformis, to the waters off the power plant. The environmental factors and their relation to ecobiology of the large quantity of salpa population that are being sucked into the intake channel of the power plant are discussed.

  3. Pharmaceutical residues in environmental waters and wastewater: current state of knowledge and future research.

    Science.gov (United States)

    Fatta-Kassinos, Despo; Meric, Sureyya; Nikolaou, Anastasia

    2011-01-01

    Pollution from pharmaceuticals in the aquatic environment is now recognized as an environmental concern in many countries. This has led to the creation of an extensive area of research, including among others: their chemical identification and quantification; elucidation of transformation pathways when present in wastewater-treatment plants or in environmental matrices; assessment of their potential biological effects; and development and application of advanced treatment processes for their removal and/or mineralization. Pharmaceuticals are a unique category of pollutants, because of their special characteristics, and their behavior and fate cannot be simulated with other chemical organic contaminants. Over the last decade the scientific community has embraced research in this specific field and the outcome has been immense. This was facilitated by advances in chromatographic techniques and relevant biological assays. Despite this, a number of unanswered questions exist and still there is much room for development and work towards a more solid understanding of the actual consequences of the release of pharmaceuticals in the environment. This review tries to present part of the knowledge that is currently available with regard to the occurrence of pharmaceutical residues in aquatic matrices, the progress made during the last several years on identification of such compounds down to trace levels, and of new, previously unidentified, pharmaceuticals such as illicit drugs, metabolites, and photo-products. It also tries to discuss the main recent findings in respect of the capacity of various treatment technologies to remove these contaminants and to highlight some of the adverse effects that may be related to their ubiquitous existence. Finally, socioeconomic measures that may be able to hinder the introduction of such compounds into the environment are briefly discussed.

  4. Remote field eddy current technique for gap measurement of horizontal flux detector guide tube in pressurized heavy water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Hoon; Jung, Hyun Kyu; Yang, Dong Ju; Cheong, Yong Moo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2004-11-15

    The fuel channels including the pressure tube(PT) and the calandria tube(CT) are important components of the pressurized heavy water reactor(PHWR). A sagging of fuel channel increases by heat and radiation exposure with the increasing operation time. The contact of fuel channel to the Horizontal flux Detector(HFD) guide tube is needed for the power plant safety. In order to solve this safety issue, the electromagnetic technique was applied to measure the status of the guide tube. The Horizontal flux Detector(HFD) guide tube and the Calandria tube(CT) in the Pressurized Heavy Water Reactor(PHWR) are cross-aligned horizontally. The remote field eddy current(RFEC) technology is applied for gap measurement between the HFD guide tube and the CT HFD guide tube can be detected by inserting the RFEC probe into pressure tube(PT) at the crossing point directly. The RFEC signals using the volume integral method(VIM) were simulated for obtaining the optimal inspection parameters. This paper shows that the simulated eddy current signals and the experimental results in variance with the CT/HFD gap.

  5. Water and Land Use Efficiency in Current and Potential Future US Corn and Brazilian Sugarcane Ethanol Systems

    Science.gov (United States)

    Warner, E. S.; Zhang, Y.; Newmark, R. L.

    2012-12-01

    Biofuels represent an opportunity for domestic fuel production from renewable energy sources with potential environmental and social benefits such as reducing greenhouse gas (GHG) and promoting rural development. However, as demand for biofuel continues to increase worldwide, concerns about land competition between food and fuel, excessive water usage and other unintended environmental consequences have grown. Through a comparative study between US corn ethanol and Brazilian sugarcane ethanol, we examine the energy, land, water and GHG performance of the two largest industrial fuel ethanol production systems in the world. Our comparisons include current and potential future systems with improved agronomic practices, crop yields, ethanol conversion processes, and utilization of agricultural residues. Our results suggest that the average water footprints of US corn ethanol and Brazilian sugarcane ethanol are fairly close (108 and 110 m3/GJ of ethanol, respectively) while the variations can range from 50 to 250 m3/GJ for sugarcane ethanol and 50 to380 m3/GJ for corn ethanol. Results emphasize the need to examine the water footprint within the context of local and regional climatic variability, water availability, competing uses (e.g. agricultural, industrial, and municipal water needs) and other ecosystem constraints. Research is under way (at the National Renewable Energy Laboratory and other institutions) to develop models to analyze water supply and demand at the watershed-scale for current and future biomass production, and to understand the tradeoffs among water supply, demand and quality due to more intensive agricultural practices and expansion of biofuels. Land use efficiency metrics, with regards to life cycle GHG emissions (without land use change) savings through gasoline displacement with ethanol, illustrate the progression of the biofuel industry and the importance of maximizing bioenergy production by utilizing both the crops and the residues. A recent

  6. Current components, water pressure, physical, and other data from moored current meters, pressure gauges, and CTD casts from CHARTER/FISHING BOATS and other platforms from the Bering Sea - Coastal Waters of Western Alaska and other locations from 14 May 1989 to 06 October 1989 (NCEI Accession 9000278)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current components, water pressure, physical, and other data were collected from moored current meters, pressure gauges, and CTD casts from CHARTER/FISHING BOATS and...

  7. Sources, fate, and pathways of Leeuwin Current water in the Indian Ocean and Great Australian Bight: A Lagrangian study in an eddy-resolving ocean model

    Science.gov (United States)

    Yit Sen Bull, Christopher; van Sebille, Erik

    2016-03-01

    The Leeuwin Current is the dominant circulation feature in the eastern Indian Ocean, transporting tropical and subtropical water southward. While it is known that the Leeuwin Current draws its water from a multitude of sources, existing Indian Ocean circulation schematics have never quantified the fluxes of tropical and subtropical source water flowing into the Leeuwin Current. This paper uses virtual Lagrangian particles to quantify the transport of these sources along the Leeuwin Current's mean pathway. Here the pathways and exchange of Leeuwin Current source waters across six coastally bound sectors on the south-west Australian coast are analyzed. This constitutes the first quantitative assessment of Leeuwin Current pathways within an offline, 50 year integration time, eddy-resolving global ocean model simulation. Along the Leeuwin Current's pathway, we find a mean poleward transport of 3.7 Sv in which the tropical sources account for 60-78% of the transport. While the net transport is small, we see large transports flowing in and out of all the offshore boundaries of the Leeuwin Current sectors. Along the Leeuwin Current's pathway, we find that water from the Indonesian Throughflow contributes 50-66% of the seasonal signal. By applying conditions on the routes particles take entering the Leeuwin Current, we find particles are more likely to travel offshore north of 30°S, while south of 30°S, particles are more likely to continue downstream. We find a 0.2 Sv pathway of water from the Leeuwin Current's source regions, flowing through the entire Leeuwin Current pathway into the Great Australian Bight.

  8. Current meter components and other data from FIXED PLATFORMS from Coastal Waters of California from 27 April 1988 to 01 June 1989 (NODC Accession 9000294)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter components data were collected from FIXED PLATFORMS in the Coastal Waters of California from 27 April 1988 to 01 June 1989. Data were collected by the...

  9. Effects of water-current speed on hematological, biochemical and immune parameters in juvenile tinfoil barb, Barbonymus schwanenfeldii (Bleeker, 1854)

    Science.gov (United States)

    Zhu, Zhiming; Song, Bolan; Lin, Xiaotao; Xu, Zhongneng

    2016-01-01

    This study examines the effect of water-current speed on hematological, biochemical and immune parameters in juvenile tinfoil barb ( Barbonymus schwanenfeldii). Blood samples were taken on days 1, 23 and 45 from control fish and from two training groups maintained at current speeds of 0.06 bl/s (body length per second), 0.66 bl/s, and 1.92 bl/s, respectively. Significantly increased red-blood-cell counts and hematocrit were observed in the post-training groups on days 23 and 45. Significantly increased hemoglobin concentrations were also observed in the 1.92 bl/s group on days 23 and 45. In contrast, values of mean corpuscular volume were significantly lower in the 1.92 bl/s group than in the other groups on day 45. Nitroblue-tetrazolium-positive cells and lysozyme and superoxidase dismutase activities in the plasma increased significantly with increasing training intensity on days 23 and 45. Antibacterial activities were significantly increased in the trained groups compared with the control group on day 23; significantly elevated alkaline phosphatase activity was observed in the 1.92 bl/s groups on day 45. Therefore, training intensities of 0.66 and 1.92 bl/s enhanced the blood oxygen-carrying capability and plasma immune parameters of juvenile tinfoil barbs.

  10. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  11. In vivo transungual iontophoresis: effect of DC current application on ionic transport and on transonychial water loss.

    Science.gov (United States)

    Dutet, Julie; Delgado-Charro, M Begoña

    2009-12-03

    The potential use of iontophoresis to improve drug penetration into the nail has been suggested. However, there is little information concerning transungual iontophoresis in vivo. This work describes the application of transungual iontophoresis to six healthy human volunteers in order to investigate key issues such as the effect of current application on ionic transport and on transonychial water loss (TOWL), and the magnitude of the voltages required for a practical use of the technique. Each volunteer participated in three experiments: passive control, 0.2 mA anodal transungual iontophoresis and 0.2 mA cathodal transungual iontophoresis. A commercial electrode on a skin site was used to complete the electrical circuit. The outward transungual extraction of sodium and chloride ions by passive diffusion and iontophoresis was quantified. Iontophoresis enhanced chloride and sodium transport approximately 8 and 27 fold respectively compared to passive diffusion. Sodium transport numbers were measured to be t(Na+)=0.51+/-0.11. TOWL was used as a potential marker of nail damage and hydration. Basal TOWL was measured before each experiment, and the return to baseline values was monitored for 1h after the treatment (passive or iontophoresis application) was finished. TOWL was increased after both iontophoretic and passive experiments and typically returned to baseline values in 1h post-treatment. The voltage of the nail-to-skin circuit was monitored during iontophoresis and compared to those observed in a skin-to-skin circuit. Nail-to-skin circuit voltages were generally approximately 50 V when the current was started and dropped fast to 20-30 V, a value comparable to that observed in the skin-to-skin circuit. On the whole, the clear enhancement of ionic transport observed, the feedback from volunteers, the small effects in TOWL, and the magnitude of voltages indicate that nail DC current iontophoresis is feasible and probably a safe technique.

  12. Current (2004-07) Conditions and Changes in Ground-Water Levels from Predevelopment to 2007, Southern High Plains Aquifer, East-Central New Mexico-Curry County, Portales, and Causey Lingo Underground Water Basins

    Science.gov (United States)

    Tillery, Anne

    2008-01-01

    The Southern High Plains aquifer is the principal aquifer in Curry and Roosevelt Counties, N. Mex., and primary source of water in southeastern New Mexico. Successful water-supply planning for New Mexico's Southern High Plains requires knowledge of the current aquifer conditions and a context to estimate future trends given current aquifer-management policy. This report provides a summary of the current (2007) water-level status of the Southern High Plains aquifer in New Mexico, including a basis for estimating future trends by comparison with historical conditions. This report includes estimates of the extent of ground-water level declines in the Curry County, Portales, and Causey-Lingo Ground-water Management Area parts of the High Plains Aquifer in eastern New Mexico since predevelopment. Maps representing 2007 water levels, water-level declines, aquifer saturated thickness, and depth to water accompanied by hydrographs from representative wells for the Southern High Plains aquifer in the Curry County, Portales, and Causey Lingo Underground Water Basins were prepared in cooperation with the New Mexico Office of the State Engineer. The results of this mapping show the water level declined as much as 175 feet in the study area at rates as high as 1.76 feet per year.

  13. Simultaneous visualization of oxygen partial pressure, current density, and water droplets in serpentine fuel cell during power generation for understanding reaction distributions

    Science.gov (United States)

    Takanohashi, Kazuhiro; Suga, Takeo; Uchida, Makoto; Ueda, Toshihide; Nagumo, Yuzo; Inukai, Junji; Nishide, Hiroyuki; Watanabe, Masahiro

    2017-03-01

    Understanding the reaction distributions inside a polymer electrolyte fuel cell (PEFC) is essential for the higher performance and durability. We have developed a new see-through cell and visualized the distributions of oxygen partial pressure and current density inside a running PEFC at the temperature of 40 and 80 °C and the relative humidity of 53%. The oxygen utilization was changed from 0% to 80% by changing the current density. At higher oxygen utilizations, the current density was higher and therefore the water generation. Generated water droplets in the flow channel were also visualized, allowing for the simultaneous visualization of the distribution of the oxygen partial pressure, current density, and water droplets. By combining the observations of all three parameters, the reactions inside a membrane-electrode assembly were discussed.

  14. Co-current air-water flow in downward sloping pipes: Transport of capacity reducing gas pockets in wastewater mains

    NARCIS (Netherlands)

    Pothof, I.W.M.

    2011-01-01

    Air-water flow is an undesired condition in many systems for the transportation of water or wastewater. Air in storm water tunnels may get trapped and negatively affect the system. Air pockets in hydropower tunnels or sewers may cause blow-back events and inadmissible pressure spikes. Water pipes an

  15. Current Status of Marker Genes of Bacteroides and Related Taxa for Identifying Sewage Pollution in Environmental Waters

    Directory of Open Access Journals (Sweden)

    Warish Ahmed

    2016-05-01

    Full Text Available Microbial source tracking (MST endeavors to determine sources of fecal pollution in environmental waters by capitalizing on the association of certain microorganisms with the gastrointestinal tract and feces of specific animal groups. Several decades of research have shown that bacteria belonging to the gut-associated order Bacteroidales, and particularly the genus Bacteroides, tend to co-evolve with the host, and are, therefore, particularly suitable candidates for MST applications. This review summarizes the current research on MST methods that employ genes belonging to Bacteroidales/Bacteroides as tracers or “markers” of sewage pollution, including known advantages and deficiencies of the many polymerase chain reaction (PCR-based methods that have been published since 2000. Host specificity is a paramount criterion for confidence that detection of a marker is a true indicator of the target host. Host sensitivity, or the prevalence of the marker in feces/waste from the target host, is necessary for confidence that absence of the marker is indicative of the absence of the pollution source. Each of these parameters can vary widely depending on the type of waste assessed and the geographic location. Differential decay characteristics of bacterial targets and their associated DNA contribute to challenges in interpreting MST results in the context of human health risks. The HF183 marker, derived from the 16S rRNA gene of Bacteroides dorei and closely related taxa, has been used for almost two decades in MST studies, and is well characterized regarding host sensitivity and specificity, and in prevalence and concentration in sewage in many countries. Other markers such as HumM2 and HumM3 show promise, but require further performance testing to demonstrate their widespread utility. An important limitation of the one-marker-one-assay approach commonly used for MST is that given the complexities of microbial persistence in environmental waters, and

  16. Health risks from large-scale water pollution: Current trends and implications for improving drinking water quality in the lower Amu Darya drainage basin, Uzbekistan

    Science.gov (United States)

    Törnqvist, Rebecka; Jarsjö, Jerker

    2010-05-01

    Safe drinking water is a primary prerequisite to human health, well being and development. Yet, there are roughly one billion people around the world that lack access to safe drinking water supply. Health risk assessments are effective for evaluating the suitability of using various water sources as drinking water supply. Additionally, knowledge of pollutant transport processes on relatively large scales is needed to identify effective management strategies for improving water resources of poor quality. The lower Amu Darya drainage basin close to the Aral Sea in Uzbekistan suffers from physical water scarcity and poor water quality. This is mainly due to the intensive agriculture production in the region, which requires extensive freshwater withdrawals and use of fertilizers and pesticides. In addition, recurrent droughts in the region affect the surface water availability. On average 20% of the population in rural areas in Uzbekistan lack access to improved drinking water sources, and the situation is even more severe in the lower Amu Darya basin. In this study, we consider health risks related to water-borne contaminants by dividing measured substance concentrations with health-risk based guideline values from the World Health Organisation (WHO). In particular, we analyse novel results of water quality measurements performed in 2007 and 2008 in the Mejdurechye Reservoir (located in the downstream part of the Amu Darya river basin). We furthermore identify large-scale trends by comparing the Mejdurechye results to reported water quality results from a considerable stretch of the Amu Darya river basin, including drainage water, river water and groundwater. The results show that concentrations of cadmium and nitrite exceed the WHO health-risk based guideline values in Mejdurechye Reservoir. Furthermore, concentrations of the since long ago banned and highly toxic pesticides dichlorodiphenyltrichloroethane (DDT) and γ-hexachlorocyclohexane (γ-HCH) were detected in

  17. Klamath River Water Quality and Acoustic Doppler Current Profiler Data from Link River Dam to Keno Dam, 2007

    Science.gov (United States)

    Sullivan, Annett B.; Deas, Michael L.; Asbill, Jessica; Kirshtein, Julie D.; Butler, Kenna D.; Stewart, Marc A.; Wellman, Roy W.; Vaughn, Jennifer

    2008-01-01

    In 2007, the U.S. Geological Survey, Watercourse Engineering, and the Bureau of Reclamation began a project to construct and calibrate a water quality and hydrodynamic model of the 21-mile reach of the Klamath River from Link River Dam to Keno Dam. To provide a basis for this work, data collection and experimental work were planned for 2007 and 2008. This report documents sampling and analytical methods and presents data from the first year of work. To determine water velocities and discharge, a series of cross-sectional acoustic Doppler current profiler (ADCP) measurements were made on the mainstem and four canals on May 30 and September 19, 2007. Water quality was sampled weekly at five mainstem sites and five tributaries from early April through early November, 2007. Constituents reported here include field parameters (water temperature, pH, dissolved oxygen concentration, specific conductance); total nitrogen and phosphorus; particulate carbon and nitrogen; filtered orthophosphate, nitrite, nitrite plus nitrate, ammonia, organic carbon, iron, silica, and alkalinity; specific UV absorbance at 254 nm; phytoplankton and zooplankton enumeration and species identification; and bacterial abundance and morphological subgroups. The ADCP measurements conducted in good weather conditions in May showed that four major canals accounted for most changes in discharge along the mainstem on that day. Direction of velocity at measured locations was fairly homogeneous across the channel, while velocities were generally lowest near the bottom, and highest near surface, ranging from 0.0 to 0.8 ft/s. Measurements in September, made in windy conditions, raised questions about the effect of wind on flow. Most nutrient and carbon concentrations were lowest in spring, increased and remained elevated in summer, and decreased in fall. Dissolved nitrite plus nitrate and nitrite had a different seasonal cycle and were below detection or at low concentration in summer. Many nutrient and

  18. Food for Thought: A Critical Overview of Current Practical and Conceptual Challenges in Trace Element Analysis in Natural Waters

    Directory of Open Access Journals (Sweden)

    Montserrat Filella

    2013-07-01

    Full Text Available The practical and conceptual challenges faced by the analysis of trace elements present in natural waters are not merely, as is often thought, an endless race towards lower detection limits or to the development of techniques allowing the determination of any possible chemical species formed by all chemical elements. Rather, as discussed in this paper, they include the development of (i robust, cheap, and reliable methods that could also be used by laypeople (the experience gained in the development of field kits for As is discussed as an example from which similar developments for other elements may be drawn; (ii more environmentally-friendly methods (the current guiding criteria probably being too simplistic; and (iii methods making it possible to follow diel concentration changes and sharp concentration variations caused by the probable increase of heavy rainfall events. This paper also claims that neither the measurement of total concentrations (reliable methods are lacking for many elements of the periodic table of trace elements, as illustrated through the cases of Bi, Te, and Sb, nor chemical speciation analysis, are as mature as often thought. In particular, chemical speciation studies demand the development of a better, comprehensive conceptual framework. A trial is carried out to lay the basis of such a framework.

  19. Assessing exposure and health consequences of chemicals in drinking water : Current state of knowledge and research needs

    NARCIS (Netherlands)

    Villanueva, Cristina M.; Kogevinas, Manolis; Cordier, Sylvaine; Templeton, Michael R.; Vermeulen, Roel; Nuckols, John R.; Nieuwenhuijsen, Mark J.; Levallois, Patrick

    2014-01-01

    Background: Safe drinking water is essential for well-being. Although microbiological contamination remains the largest cause of water-related morbidity and mortality globally, chemicals in water supplies may also cause disease, and evidence of the human health consequences is limited or lacking for

  20. MIXED FINITE ELEMENT METHODS FOR THE SHALLOW WATER EQUATIONS INCLUDING CURRENT AND SILT SEDIMENTATION ( Ⅱ )-THE DISCRETE-TIME CASE ALONG CHARACTERISTICS

    Institute of Scientific and Technical Information of China (English)

    罗振东; 朱江; 曾庆存; 谢正辉

    2004-01-01

    The mixed finite element (MFE) methods for a shallow water equation system consisting of water dynamics equations, silt transport equation, and the equation of bottom topography change were derived. A fully discrete MFE scheme for the discrete-time along characteristics is presented and error estimates are established. The existence and convergence of MFE solution of the discrete current velocity, elevation of the bottom topography, thickness of fluid column, and mass rate of sediment is demonstrated.

  1. CURRENT DIRECTION, CURRENT SPEED and other data from A. P. KNIGHT in the Coastal Waters of SE Alaska and Coastal Waters of British Columbia from 1971-11-01 to 1974-02-01 (NCEI Accession 7700091)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Canadian Current Meter Data for napising. Data collected as part of the Howe Sound Current Metering Program Data during November 16, 1971 - February 1, 1974 by the...

  2. Remote sensing of sea surface nutrient in the frontal zone of Changjiang diluted water and the Taiwan Warm Current

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaoyu; LIN Yi'an; HE Xianqiang; WANG Difeng; GONG fang; ZHANG Wei

    2007-01-01

    Field investigation was carried out during 4 to 15 April 2001 around the Changjiang River Estuary. The similar distribution of sea surface nutrients and suspended sediment (SS) concentration is attributed to the physical mixing of Changjiang diluted water (CDW) with the Taiwan Warm Current (TWC). On the basis of the observed positive relationship between total phosphorus (TP) and SS concentration, the sea surface TP is inversed from satellite SS data. SS is believed to be an ideal eutrophic state assessing index substitution for TP, the eutrophication classification critical value of SS adopted in this research was based on the linear model: cTP=0.000 6cSSsat+0.016 3, r2=0.564 5, n=32. Although lack of in-situ chromophoric dissolved organic matter (CDOM) measurement, a good relationship was observed between the in-situ DIN (dissolved inorganic nitrogen) concentration with near real time SeaWiFS absorption coefficient of CDOM (ACD) data: cDIN=1.406 5AACBsat-0.035 9,r2=0.741 5,n=16. This empirical regression algorithm was also utilized for inversing the DIN concentration from SeaWiFS ACD data, and for establishing the eutrophication classification critical value of satellite ACD data. The established remote eutrophication classification system was later used for seawater eutrophic state assessment. The evaluation suggested that the Zhoushan Fishing Ground especially the western border is affected seriously with the nutrient input. The nutrient is mainly from the terrestrial source transported by the Changjiang River runoff. The seawater quality classification precision was assessed by in-situ data, which suggested the seawater quality distribution is similar to the two classification systems, and the remote classification error is below 25%.

  3. Constraining Annual Water Balance Estimates with Basin-Scale Observations from the Airborne Snow Observatory during the Current Californian Drought

    Science.gov (United States)

    Bormann, K.; Painter, T. H.; Marks, D. G.; Hedrick, A. R.; Deems, J. S.; Patterson, V.; McGurk, B. J.

    2015-12-01

    One of the great unknowns in mountain hydrology is how much water is stored within a seasonal snowpack at the basin scale. Quantifying mountain water resources is critical for assisting with water resource management, but has proven elusive due to high spatial and temporal variability of mountain snow cover, complex terrain, accessibility constraints and limited in-situ networks. The Airborne Snow Observatory (ASO, aso.jpl.nasa.gov) uses coupled airborne LiDAR and spectrometer instruments for high resolution snow depth retrievals which are used to derive unprecedented basin-wide estimates of snow water mass (snow water equivalent, SWE). ASO has been operational over key basins in the Sierra Nevada Mountains in California since 2013. Each operational year has been very dry, with precipitation in 2013 at 75% of average, 2014 at 50% of average and 2015 - the lowest snow year on record for the region. With vastly improved estimates of the snowpack water content from ASO, we can now for the first time conduct observation-based mass balance accounting of surface water in snow-dominated basins, and reconcile these estimates with observed reservoir inflows. In this study we use ASO SWE data to constrain mass balance accounting of basin annual water storages to quantify the water contained within the snowpack above the Hetch Hetchy water supply reservoir (Tuolumne River basin, California). The analysis compares and contrasts annual snow water volumes from observed reservoir inflows, snow water volume estimates from ASO, a physically based model that simulates the snowpack from meteorological inputs and a semi-distributed hydrological model. The study provides invaluable insight to the overall volume of water contained within a seasonal snowpack during a severe drought and how these quantities are simulated in our modelling systems. We envisage that this research will be of great interest to snowpack modellers, hydrologists, dam operators and water managers worldwide.

  4. An ecotoxicological analysis of the sediment quality in a European Atlantic harbor emphasizes the current limitations of the Water Framework Directive.

    Science.gov (United States)

    Gonçalves, Sandra F; Calado, Ricardo; Gomes, Newton C M; Soares, Amadeu M V M; Loureiro, Susana

    2013-07-15

    The "PortoNovo" project was developed to standardize the methodologies for water quality management in the port areas of coastal Atlantic regions to improve the Water Frame Directive (WFD) for these specific water bodies. Under this scope, water and sediment samples were collected from five sites within the Port of Aveiro, Portugal. According to the physical and chemical parameters that were analyzed (i.e., metals, total organic carbon, polychlorinated biphenyls and polycyclic aromatic hydrocarbons), the sediments were not considered at risk based on European sediment quality laws. However, the bioassays that were performed on the sediment samples (Microtox®) and the standardized acute toxicity test using the marine rotifer, Brachionus plicatilis, on sediment elutriates revealed higher toxicity levels. The use of bioassays to assess sediment quality clearly complements more conservative approaches and highlights current gaps within the WFD. The approach presented here can be easily transferred to other port areas for more reliable water quality management.

  5. Copepod flow modes and modulation: a modelling study of the water currents produced by an unsteadily swimming copepod

    OpenAIRE

    2007-01-01

    Video observation has shown that feeding-current-producing calanoid copepods modulate their feeding currents by displaying a sequence of different swimming behaviours during a time period of up to tens of seconds. In order to understand the feeding-current modulation process, we numerically modelled the steady feeding currents for different modes of observed copepod motion behaviours (i.e. free sinking, partial sinking, hovering, vertical swimming upward and horizontal swimming backward or fo...

  6. Next-generation sequencing (NGS) for assessment of microbial water quality: current progress, challenges, and future opportunities.

    Science.gov (United States)

    Tan, BoonFei; Ng, Charmaine; Nshimyimana, Jean Pierre; Loh, Lay Leng; Gin, Karina Y-H; Thompson, Janelle R

    2015-01-01

    Water quality is an emergent property of a complex system comprised of interacting microbial populations and introduced microbial and chemical contaminants. Studies leveraging next-generation sequencing (NGS) technologies are providing new insights into the ecology of microbially mediated processes that influence fresh water quality such as algal blooms, contaminant biodegradation, and pathogen dissemination. In addition, sequencing methods targeting small subunit (SSU) rRNA hypervariable regions have allowed identification of signature microbial species that serve as bioindicators for sewage contamination in these environments. Beyond amplicon sequencing, metagenomic and metatranscriptomic analyses of microbial communities in fresh water environments reveal the genetic capabilities and interplay of waterborne microorganisms, shedding light on the mechanisms for production and biodegradation of toxins and other contaminants. This review discusses the challenges and benefits of applying NGS-based methods to water quality research and assessment. We will consider the suitability and biases inherent in the application of NGS as a screening tool for assessment of biological risks and discuss the potential and limitations for direct quantitative interpretation of NGS data. Secondly, we will examine case studies from recent literature where NGS based methods have been applied to topics in water quality assessment, including development of bioindicators for sewage pollution and microbial source tracking, characterizing the distribution of toxin and antibiotic resistance genes in water samples, and investigating mechanisms of biodegradation of harmful pollutants that threaten water quality. Finally, we provide a short review of emerging NGS platforms and their potential applications to the next generation of water quality assessment tools.

  7. Removal of Pollutant Compounds From Water Supplies Using Ozone, Ultraviolet Light, and a Counter Current Packed Column

    Science.gov (United States)

    1991-01-01

    Wesley Eckenfelder , Jr., Industrial Water Pollutuion Control, 2nd ed., (New York: McGraw-Hill, 1989), 136. Bibliography Bellamy, William D., Hickman...WPCF, Vol. 63, no. 2 (mar/Apr 1991): 120-28. Eckenfelder , W. Wesley, Industrial Water Pollutuion Control, 2nd ed., New York: McGraw-Hill, 1989. Freeman

  8. Land Use and Water Efficiency in Current and Potential Future U.S. Corn and Brazilian Sugarcane Ethanol Systems (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Warner, E.; Zhang, Y.; Chum, H.; Newmark, R.

    2012-11-01

    The potential for unintended consequences of biofuels--competition for land and water--necessitates that sustainable biofuel expansion considers the complexities of resource requirements within specific context (e.g., technology, feedstock, supply chain, local resource availability).

  9. Next-generation sequencing (NGS) for assessment of microbial water quality: current progress, challenges, and future opportunities

    Science.gov (United States)

    Tan, BoonFei; Ng, Charmaine; Nshimyimana, Jean Pierre; Loh, Lay Leng; Gin, Karina Y.-H.; Thompson, Janelle R.

    2015-01-01

    Water quality is an emergent property of a complex system comprised of interacting microbial populations and introduced microbial and chemical contaminants. Studies leveraging next-generation sequencing (NGS) technologies are providing new insights into the ecology of microbially mediated processes that influence fresh water quality such as algal blooms, contaminant biodegradation, and pathogen dissemination. In addition, sequencing methods targeting small subunit (SSU) rRNA hypervariable regions have allowed identification of signature microbial species that serve as bioindicators for sewage contamination in these environments. Beyond amplicon sequencing, metagenomic and metatranscriptomic analyses of microbial communities in fresh water environments reveal the genetic capabilities and interplay of waterborne microorganisms, shedding light on the mechanisms for production and biodegradation of toxins and other contaminants. This review discusses the challenges and benefits of applying NGS-based methods to water quality research and assessment. We will consider the suitability and biases inherent in the application of NGS as a screening tool for assessment of biological risks and discuss the potential and limitations for direct quantitative interpretation of NGS data. Secondly, we will examine case studies from recent literature where NGS based methods have been applied to topics in water quality assessment, including development of bioindicators for sewage pollution and microbial source tracking, characterizing the distribution of toxin and antibiotic resistance genes in water samples, and investigating mechanisms of biodegradation of harmful pollutants that threaten water quality. Finally, we provide a short review of emerging NGS platforms and their potential applications to the next generation of water quality assessment tools. PMID:26441948

  10. Next-generation sequencing (NGS for assessment of microbial water quality: current progress, challenges, and future opportunities

    Directory of Open Access Journals (Sweden)

    BoonFei eTan

    2015-09-01

    Full Text Available Water quality is an emergent property of a complex system comprised of interacting microbial populations and introduced microbial and chemical contaminants. Studies leveraging next-generation sequencing (NGS technologies are providing new insights into the ecology of microbially mediated processes that influence fresh water quality such as algal blooms, contaminant biodegradation, and pathogen dissemination. In addition, sequencing methods targeting small subunit (SSU rRNA hypervariable regions have allowed identification of signature microbial species that serve as bioindicators for sewage contamination in these environments. Beyond amplicon sequencing, metagenomic and metatranscriptomic analyses of microbial communities in fresh water environments reveal the genetic capabilities and interplay of waterborne microorganisms, shedding light on the mechanisms for production and biodegradation of toxins and other contaminants. This review discusses the challenges and benefits of applying NGS-based methods to water quality research and assessment. We will consider the suitability and biases inherent in the application of NGS as a screening tool for assessment of biological risks and discuss the potential and limitations for direct quantitative interpretation of NGS data. Secondly, we will examine case studies from recent literature where NGS based methods have been applied to topics in water quality assessment, including development of bioindicators for sewage pollution and microbial source tracking, characterizing the distribution of toxin and antibiotic resistance genes in water samples, and investigating mechanisms of biodegradation of harmful pollutants that threaten water quality. Finally, we provide a short review of emerging NGS platforms and their potential applications to the next generation of water quality assessment tools.

  11. Observations of wind-generated waves on variable current. [laboratory ocean dynamics for water wave generator research

    Science.gov (United States)

    Long, S. R.; Huang, N. E.

    1976-01-01

    Laboratory measurements utilizing a laser probe are made for the slopes of wind waves generated on both positive and negative currents at different values of fetch. The data are then processed electronically to yield an average wave-slope spectrum in frequency space with 128 degrees of freedom. These spectra are used to obtain the growth of the spectral components at various frequency bands for increasing wind and different values of fetch and current. The results indicate that the growth of these components is not monotonic with the frictional wind speed, but rather exhibits an 'overshoot' phenomena at lower values of frictional wind speed, and in addition, displays a significant effect due to current. The peak location and spectral intensity of the spectra also show strong influence by the current condition. This results in the rms surface slope value increasing with negative current and decreasing with positive current. The results agree qualitatively with some theoretical predictions. The potential use of the current-induced effects as a means for remote sensing of ocean current is also briefly discussed.

  12. Microbial Contamination Detection in Water Resources: Interest of Current Optical Methods, Trends and Needs in the Context of Climate Change

    Directory of Open Access Journals (Sweden)

    Aude-Valérie Jung

    2014-04-01

    Full Text Available Microbial pollution in aquatic environments is one of the crucial issues with regard to the sanitary state of water bodies used for drinking water supply, recreational activities and harvesting seafood due to a potential contamination by pathogenic bacteria, protozoa or viruses. To address this risk, microbial contamination monitoring is usually assessed by turbidity measurements performed at drinking water plants. Some recent studies have shown significant correlations of microbial contamination with the risk of endemic gastroenteresis. However the relevance of turbidimetry may be limited since the presence of colloids in water creates interferences with the nephelometric response. Thus there is a need for a more relevant, simple and fast indicator for microbial contamination detection in water, especially in the perspective of climate change with the increase of heavy rainfall events. This review focuses on the one hand on sources, fate and behavior of microorganisms in water and factors influencing pathogens’ presence, transportation and mobilization, and on the second hand, on the existing optical methods used for monitoring microbiological risks. Finally, this paper proposes new ways of research.

  13. Microbial contamination detection in water resources: interest of current optical methods, trends and needs in the context of climate change.

    Science.gov (United States)

    Jung, Aude-Valérie; Le Cann, Pierre; Roig, Benoit; Thomas, Olivier; Baurès, Estelle; Thomas, Marie-Florence

    2014-04-17

    Microbial pollution in aquatic environments is one of the crucial issues with regard to the sanitary state of water bodies used for drinking water supply, recreational activities and harvesting seafood due to a potential contamination by pathogenic bacteria, protozoa or viruses. To address this risk, microbial contamination monitoring is usually assessed by turbidity measurements performed at drinking water plants. Some recent studies have shown significant correlations of microbial contamination with the risk of endemic gastroenteresis. However the relevance of turbidimetry may be limited since the presence of colloids in water creates interferences with the nephelometric response. Thus there is a need for a more relevant, simple and fast indicator for microbial contamination detection in water, especially in the perspective of climate change with the increase of heavy rainfall events. This review focuses on the one hand on sources, fate and behavior of microorganisms in water and factors influencing pathogens' presence, transportation and mobilization, and on the second hand, on the existing optical methods used for monitoring microbiological risks. Finally, this paper proposes new ways of research.

  14. Current situation of arsenism prevention and water improvement in Jilin province%吉林省防砷改水现状分析

    Institute of Scientific and Technical Information of China (English)

    张海涛; 张秀丽; 姜爽; 肖禹; 韩昌; 衣伟; 张立波; 姜海峰; 张晓东

    2013-01-01

    Objective To find out current situation of arsenism prevention and water improvement in Jilin province so as to provide scientific basis for strategic adjustment of endemic arsenism prevention and control.Methods With reference to historical data,we found out current situation of water improvement and water arsenic content in endemic arsenism area and latent area,we carried out survey on management and use of water improvement projects and benefit from the projects.Results Water improvement projects were carried out in 318 villages among 361villages in endemic arsenism areas and latent areas and water improvement rate was 88.09%,314 water improvement projects were used normally and the rate of normal usage was 98.74%,298projects of water improvement were found qualified in water arsenic content with qualification rate of 94.90%.Water arsenic content in 16 projects were found exceeding the standard with the rate of 5.10%.314 water improvement projects of normal use covered 36 287 families,and 32 770 families drank water from the projects,298 projects of qualified water arsenic content covered 35039 families,31 600 families got benefit from that.16 projects of unqualified water arsenic content covered 1 248 families and 1 170 families drank water from the projects.Conclusion Water was not improved in some endemic arsenism latent areas,and some projects were scrapped and water arsenic content exceeded the standard.It means that work of water improvement for endemic arsenism still needs to be strengthened.%目的 摸清吉林省防砷改水现状,为调整地方性砷中毒防治策略提供科学依据.方法 查阅历史资料掌握地方性砷中毒病区及潜在病区(屯)改水情况和改水后水砷含量,深入病区对改水工程使用管理情况和居民受益情况开展现况调查.结果 361个地方性砷中毒病区及潜在病区(屯)共改水318个,改水率为88.09%,正常使用工程314个,正常使用率为98.74

  15. Anthropogenic organochlorine compounds as potential tracers for regional water masses: A case study of estuarine plume, coastal eddy, wind-driven upwelling and long-range warm current.

    Science.gov (United States)

    Ya, Miaolei; Wu, Yuling; Li, Yongyu; Wang, Xinhong

    2017-03-01

    Water masses are the crucial factor driving the terrigenous anthropogenic organochlorine compounds (OCs) migration from the coast to open sea. Therefore, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in the Northern South China Sea (NSCS), where different types of water masses are generated by the East Asian summer monsoon: Pearl River estuary plume (PREP), Guangdong offshore eddy (GDEC), South China Sea warm current (SCSWC) and wind-driven upwelling current (WDUC). No discrepant distributions of OC concentrations were found in these water masses (p > 0.05). However, compositions and diagnostic ratios of HCHs, DDTs, trans- or cis-chlordane and PCBs could reflect the discrepancies in the input, transport and transformation of OCs caused by the hydrological characteristics of water masses, therefore, this allowing them to serve as potential tracers of regional water masses. In detail, α/γ-HCH and β-HCH percentages could indicate the weathered residue in the GDEC, long-range transport in the SCSWC, rapid photodegradation in the surface WDUC and biodegradation in the deep WDUC, respectively. The predominance of o, p'-DDT and p, p'-DDT could indicate fresh input in the PREP, GDEC and WDUC. DDT/DDTs of ratios <0.5 also reflected long-range transport in the SCSWC. Different DDD/DDE ratios indicated different oxygen environments of microbial degradation in the surface and deep water of the WDUC. Trans/cis-chlordane ratios could indicate the selective degradation of trans-chlordane in different water masses. Finally, a higher proportion of penta-PCB could reflect the strong paint additive sources carried by river erosion in the PREP.

  16. On the predictability of high water level along the US East Coast: can the Florida Current measurement be an indicator for flooding caused by remote forcing?

    Science.gov (United States)

    Ezer, Tal; Atkinson, Larry P.

    2017-06-01

    Recent studies show that in addition to wind and air pressure effects, a significant portion of the variability of coastal sea level (CSL) along the US East Coast can be attributed to non-local factors such as variations in the Gulf Stream and the North Atlantic circulation; these variations can cause unpredictable coastal flooding. The Florida Current transport (FCT) measurement across the Florida Straits monitors those variations, and thus, the study evaluated the potential of using the FCT as an indicator for anomalously high water level along the coast. Hourly water level data from 12 tide gauge stations over 12 years are used to construct records of maximum daily water levels (MDWL) that are compared with the daily FCT data. An empirical mode decomposition (EMD) approach is used to divide the data into high-frequency modes (periods T flooding events; it is estimated that ˜10-25% of the sea level variability in those modes can be attributed to variations in the FCT. An example from Hurricane Joaquin (September-October, 2015) demonstrates how an offshore storm that never made landfall can cause a weakening of the FCT and unexpected high water level and flooding along the US East Coast. A regression-prediction model based on the MDWL-FCT correlation shows some skill in estimating high water levels during past storms; the water level prediction is more accurate for slow-moving and offshore storms than it is for fast-moving storms. The study can help to improve water level prediction since current storm surge models rely on local wind but may ignore remote forcing.

  17. Influence of current velocity and wind speed on air-water gas exchange in a mangrove estuary

    Science.gov (United States)

    Ho, David T.; Coffineau, Nathalie; Hickman, Benjamin; Chow, Nicholas; Koffman, Tobias; Schlosser, Peter

    2016-04-01

    Knowledge of air-water gas transfer velocities and water residence times is necessary to study the fate of mangrove derived carbon exported into surrounding estuaries and ultimately to determine carbon balances in mangrove ecosystems. For the first time, the 3He/SF6 dual tracer technique, which has been proven to be a powerful tool to determine gas transfer velocities in the ocean, is applied to Shark River, an estuary situated in the largest contiguous mangrove forest in North America. The mean gas transfer velocity was 3.3 ± 0.2 cm h-1 during the experiment, with a water residence time of 16.5 ± 2.0 days. We propose a gas exchange parameterization that takes into account the major sources of turbulence in the estuary (i.e., bottom generated shear and wind stress).

  18. Measurement of single pi0 production in neutral current neutrino interactions with water by a 1.3 GeV wide band muon neutrino beam

    CERN Document Server

    Nakayama, S; Aoki, S; Ashie, Y; Bhang, H; Boyd, S; Casper, D; Choi, J H; Fukuda, S; Fukuda, Y; Gran, R; Hara, T; Hasegawa, M; Hasegawa, T; Hayashi, K; Hayato, Y; Hill, J; Ichikawa, A K; Ikeda, A; Inagaki, T; Ishida, T; Ishii, T; Ishitsuka, M; Itow, Y; Iwashita, T; Jang, H I; Jang, J S; Jeon, E J; Joo, K K; Jung, C K; Kajita, T; Kameda, J; Kaneyuki, K; Kato, I; Kearns, E; Kibayashi, A; Kielczewska, D; Kim, B J; Kim, C O; Kim, J Y; Kim, S B; Kobayashi, K; Kobayashi, T; Koshio, Y; Kropp, W R; Learned, J G; Lim, S H; Lim, I T; Maesaka, H; Maruyama, T; Matsuno, S; Mauger, C; McGrew, C; Minamino, A; Mine, S; Miura, M; Miyano, K; Morita, T; Moriyama, S; Nakahata, M; Nakamura, K; Nakano, I; Nakata, F; Nakaya, T; Nakayama, S; Namba, T; Nambu, R; Nishikawa, K; Nishiyama, S; Noda, S; Obayashi, Y; Okada, A; Oyama, Y; Pac, M Y; Park, H; Saji, C; Sakuda, M; Sarrat, A; Sasaki, T; Sasao, N; Scholberg, K; Sekiguchi, M; Sharkey, E; Shiozawa, M; Shiraishi, K K; Smy, M B; Sobel, H W; Stone, J L; Suga, Y; Sulak, L R; Suzuki, A; Suzuki, Y; Takeuchi, Y; Tamura, N; Tanaka, M; Totsuka, Y; Ueda, S; Vagins, M R; Walter, C W; Wang, W; Wilkes, R J; Yamada, S; Yamamoto, S; Yanagisawa, C; Yokoyama, H; Yoo, J; Yoshida, M; Zalipska, J

    2005-01-01

    Neutral current single pi0 production induced by neutrinos with a mean energy of 1.3 GeV is measured at a 1000 ton water Cherenkov detector as a near detector of the K2K long baseline neutrino experiment. The cross section for this process relative to the total charged current cross section is measured to be 0.064 +- 0.001 (stat.) +- 0.007 (sys.). The momentum distribution of produced pi0s is measured and is found to be in good agreement with an expectation from the present knowledge of the neutrino cross sections.

  19. Water

    Science.gov (United States)

    Leopold, Luna Bergere; Baldwin, Helene L.

    1962-01-01

    What do you use water for?If someone asked you this question you would probably think right away of water for drinking. Then you would think of water for bathing, brushing teeth, flushing the toilet. Your list would get longer as you thought of water for cooking, washing the dishes, running the garbage grinder. Water for lawn watering, for play pools, for swimming pools, for washing the car and the dog. Water for washing machines and for air conditioning. You can hardly do without water for fun and pleasure—water for swimming, boating, fishing, water-skiing, and skin diving. In school or the public library, you need water to wash your hands, or to have a drink. If your home or school bursts into flames, quantities of water are needed to put it out.In fact, life to Americans is unthinkable without large supplies of fresh, clean water. If you give the matter a little thought, you will realize that people in many countries, even in our own, may suffer from disease and dirt simply because their homes are not equipped with running water. Imagine your own town if for some reason - an explosion, perhaps - water service were cut off for a week or several weeks. You would have to drive or walk to a neighboring town and bring water back in pails. Certainly if people had to carry water themselves they might not be inclined to bathe very often; washing clothes would be a real chore.Nothing can live without water. The earth is covered by water over three-fourths of its surface - water as a liquid in rivers, lakes and oceans, and water as ice and snow on the tops of high mountains and in the polar regions. Only one-quarter of our bodies is bone and muscle; the other three-fourths is made of water. We need water to live, and so do plants and animals. People and animals can live a long time without food, but without water they die in a few days. Without water, everything would die, and the world would turn into a huge desert.

  20. Structural features and functional properties of water in model DMPC membranes: thermally stimulated depolarization currents (TSDCs) and Fourier transform infrared (FTIR) studies

    Science.gov (United States)

    Bridelli, M. G.; Capelletti, R.; Mora, C.

    2013-12-01

    Thermally stimulated depolarization currents (TSDCs) and Fourier transform infrared (FTIR) spectroscopies were employed to investigate the state of water incorporated in a model DMPC (dimyristoyl-phosphatidylcholine) membrane. The lipid multilayers, highly inhomogeneous from the dielectric point of view, originate complex TSDC spectra critically dependent on the sample water content and thermal history. Different temperature ranges were chosen to polarize the sample, i.e. 100-300 K (type I) and 100-285 K (type II). The purpose of the latter choice was to avoid any sample heating above the DMPC phase transition temperature (295 K) along the sample polarization. According to the results, water in a fully hydrated system (aw = 0.92) (1) is ordered around the hydrophilic head molecular groups, (2) is layered in the interbilayer space and (3) penetrates among the hydrocarbon chains. It can assume different local structural configurations depending on the lipid packing. Irreversible conformational transitions in the lipid array system were monitored as a consequence of different dehydration treatments. FTIR absorption measurements were performed to study the water sorption kinetics into a DMPC thin film. The water related OH band was decomposed into three components, describing three water states, with different propensity to the H-bond formation. The changes of the lipid characteristic groups (CH2/CH3, PO_{2}^{-} and C=O) absorption bands as a function of increasing hydration level were monitored and discussed.

  1. Clinical symptoms, signs and tests for identification of impending and current water-loss dehydration in older people

    NARCIS (Netherlands)

    Hooper, L.; Abdelhamid, A.; Attreed, N.J.; Campbell, W.W.; Channell, A.M.; Chassagne, P.; Culp, K.R.; Fletcher, S.J.; Fortes, M.B.; Fuller, N.; Gaspar, P.M.; Gilbert, D.J.; Heathcote, A.C.; Kafri, M.W.; Kajii, F.; Lindner, G.; Mack, G.W.; Mentes, J.C.; Merlani, P.; Needham, R.A.; Olde Rikkert, M.G.M.; Perren, A.; Powers, J.; Ranson, S.C.; Ritz, P.; Rowat, A.M.; Sjostrand, F.; Smith, A.C.; Stookey, J.J.D.; Stotts, N.A.; Thomas, D.R.; Vivanti, A.; Wakefield, B.J.; Waldreus, N.; Walsh, N.P.; Ward, S.; Potter, J.F.; Hunter, P.

    2015-01-01

    BACKGROUND: There is evidence that water-loss dehydration is common in older people and associated with many causes of morbidity and mortality. However, it is unclear what clinical symptoms, signs and tests may be used to identify early dehydration in older people, so that support can be mobilised t

  2. Are current phosphorus risk indicators useful to predict the quality of surface waters in southern manitoba, Canada?

    Science.gov (United States)

    Salvano, Esther; Flaten, Don N; Rousseau, Alain N; Quilbe, Renaud

    2009-01-01

    Many phosphorus (P) risk indicators have been developed to assess the risk of P loss from agricultural land to surface water. Most of these indicators are designed for land and climates where rainfall-induced erosion of particulate P from sloping landscapes is the main process of P transport. No indicators have been validated in the Canadian Prairies, where P losses are driven by snowmelt-driven runoff over nearly level landscapes and frozen soils. The objective of this project was to evaluate the relationship between water quality data for P from 14 watersheds and three existing P risk indicators for their potential use in the southern Manitoba prairie region of Canada. None of the indicators, including Birr and Mulla's P Index, a preliminary P risk indicator for Manitoba, and a preliminary version of Canada's National Indicator of Risk of Water Contamination by Phosphorus, was significantly correlated with mean concentrations of total P in water or P export per hectare. Although erosion risk was a significant factor influencing the value of these indexes, erosion risk was not correlated with either measure of P loss in these watersheds. Several other watershed characteristics, including average soil test P concentrations, livestock density, proportion of land in annual crops, and the land's inherent capability for agricultural production, were strongly correlated with P concentrations in water (r = 0.80***, r = 0.63**, 0.76***, and -0.70**, respectively). Therefore, these types of P risk indicators require modifications to estimate the risk of P loss under the soil, landscape, and climatic conditions of southern Manitoba.

  3. Amoeba-related health risk in drinking water systems: could monitoring of amoebae be a complementary approach to current quality control strategies?

    Science.gov (United States)

    Codony, Francesc; Pérez, Leonardo Martín; Adrados, Bárbara; Agustí, Gemma; Fittipaldi, Mariana; Morató, Jordi

    2012-01-01

    Culture-based methods for fecal indicator microorganisms are the standard protocol to assess potential health risk from drinking water systems. However, these traditional fecal indicators are inappropriate surrogates for disinfection-resistant fecal pathogens and the indigenous pathogens that grow in drinking water systems. There is now a range of molecular-based methods, such as quantitative PCR, which allow detection of a variety of pathogens and alternative indicators. Hence, in addition to targeting total Escherichia coli (i.e., dead and alive) for the detection of fecal pollution, various amoebae may be suitable to indicate the potential presence of pathogenic amoeba-resisting microorganisms, such as Legionellae. Therefore, monitoring amoeba levels by quantitative PCR could be a useful tool for directly and indirectly evaluating health risk and could also be a complementary approach to current microbial quality control strategies for drinking water systems.

  4. A TECHNICAL ASSESSMENT OF THE CURRENT WATER POLICY BOUNDARY AT U.S. DEPARTMENT OF ENERGY, PADUCAH GASEOUS DIFFUSION PLANT, PADUCAH, KENTUCKY

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-12-13

    In 1988, groundwater contaminated with trichloroethene (TCE) and technetium-99 (Tc-99) was identified in samples collected from residential water wells withdrawing groundwater from the Regional Gravel Aquifer (RGA) north of the Paducah Gaseous Diffusion Plant (PGDP) facility. In response, the U.S. Department of Energy (DOE) provided temporary drinking water supplies to approximately 100 potentially affected residents by initially supplying bottled water, water tanks, and water-treatment systems, and then by extending municipal water lines, all at no cost, to those persons whose wells could be affected by contaminated groundwater. The Water Policy boundary was established in 1993. In the Policy, DOE agreed to pay the reasonable monthly cost of water for homes and businesses and, in exchange, many of the land owners signed license agreements committing to cease using the groundwater via rural water wells. In 2012, DOE requested that Oak Ridge Associated Universities (ORAU), managing contractor of Oak Ridge Institute for Science and Education (ORISE), provide an independent assessment of the quality and quantity of the existing groundwater monitoring data and determine if there is sufficient information to support a modification to the boundary of the current Water Policy. As a result of the assessment, ORAU concludes that sufficient groundwater monitoring data exists to determine that a shrinkage and/or shift of the plume(s) responsible for the initial development of this policy has occurred. Specifically, there is compelling evidence that the TCE plume is undergoing shrinkage due to natural attenuation and associated degradation. The plume shrinkage (and migration) has also been augmented in local areas where large volumes of groundwater were recovered by pump-and treat remedial systems along the eastern and western boundaries of the Northwest Plume, and in other areas where pump-and-treat systems have been deployed by DOE to remove source contaminants. The

  5. Two-phase flow experiments on Counter-Current Flow Limitation in a model of the hot leg of a pressurized water reactor (2015 test series)

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, Matthias; Lucas, Dirk; Pietruske, Heiko; Szalinski, Lutz

    2016-12-15

    Counter-Current Flow Limitation (CCFL) is of importance for PWR safety analyses in several accident scenarios connected with loss of coolant. Basing on the experiences obtained during a first series of hot leg tests now new experiments on counter-current flow limitation were conducted in the TOPFLOW pressure vessel. The test series comprises air-water tests at 1 and 2 bar as well as steam-water tests at 10, 25 and 50 bar. During the experiments the flow structure was observed along the hot leg model using a high-speed camera and web-cams. In addition pressure was measured at several positions along the horizontal part and the water levels in the reactor-simulator and steam-generator-simulator tanks were determined. This report documents the experimental setup including the description of operational and special measuring techniques, the experimental procedure and the data obtained. From these data flooding curves were obtained basing on the Wallis parameter. The results show a slight shift of the curves in dependency of the pressure. In addition a slight decrease of the slope was found with increasing pressure. Additional investigations concern the effects of hysteresis and the frequencies of liquid slugs. The latter ones show a dependency on pressure and the mass flow rate of the injected water. The data are available for CFD-model development and validation.

  6. Current direction, bathythermograph (xbt), CTD, and other data from moored current meter casts and other instruments in the Coastal Waters of California as part of the North California Coastal Circulation Study (NCCCS) project, 1987-03-09 to 1989-11-01 (NCEI Accession 9000209)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, bathythermograph (xbt), CTD, and other data were collected using moored current meter casts and other instruments in the Coastal Waters of...

  7. Water

    Science.gov (United States)

    ... Lead Poisoning Prevention Training Center (HHLPPTC) Training Tracks Water Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir For information about lead in water in Flint, MI, please visit http://www.phe. ...

  8. Relationship between anode material, supporting electrolyte and current density during electrochemical degradation of organic compounds in water

    Energy Technology Data Exchange (ETDEWEB)

    Guzmán-Duque, Fernando L. [Grupo de diagnóstico y control de la contaminación, Facultad de ingeniería, Universidad de Antioquia, A.A. 1226, Medellín (Colombia); Palma-Goyes, Ricardo E. [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquía Udea, A.A. 1226, Medellín (Colombia); González, Ignacio [Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Química, Av. San Rafael Atlixco No 186, C.P 09340, México D.F (Mexico); Peñuela, Gustavo [Grupo de diagnóstico y control de la contaminación, Facultad de ingeniería, Universidad de Antioquia, A.A. 1226, Medellín (Colombia); Torres-Palma, Ricardo A., E-mail: rtorres@matematicas.udea.edu.co [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquía Udea, A.A. 1226, Medellín (Colombia)

    2014-08-15

    Highlights: • Pathway and efficiency are linked to the current-electrode–electrolyte interaction. • Unlike BDD, IrO{sub 2} route was independent of current but dependent on the electrolyte. • IrO{sub 2}/SO{sub 4}{sup 2−} and IrO{sub 2}/Cl{sup −} routes were via IrO{sub 3} and chlorine species, respectively. • BDD/SO{sub 4}{sup 2−} and IrO{sub 2}/Cl{sup −} systems were favored at low and high currents, respectively. - Abstract: Taking crystal violet (CV) dye as pollutant model, the electrode, electrolyte and current density (i) relationship for electro-degrading organic molecules is discussed. Boron-doped diamond (BDD) or Iridium dioxide (IrO{sub 2}) used as anode materials were tested with Na{sub 2}SO{sub 4} or NaCl as electrolytes. CV degradation and generated oxidants showed that degradation pathways and efficiency are strongly linked to the current density-electrode–electrolyte interaction. With BDD, the degradation pathway depends on i: If i < the limiting current density (i{sub lim}), CV is mainly degraded by ·OH radicals, whereas if i > i{sub lim}, generated oxidants play a major role in the CV elimination. When IrO{sub 2} was used, CV removal was not dependent on i, but on the electrolyte. Pollutant degradation in Na{sub 2}SO{sub 4} on IrO{sub 2} seems to occur via IrO{sub 3}; however, in the presence of NaCl, degradation was dependent on the chlorinated oxidative species generated. In terms of efficiency, the Na{sub 2}SO{sub 4} electrolyte showed better results than NaCl when BDD anodes were employed. On the contrary, NaCl was superior when combined with IrO{sub 2}. Thus, the IrO{sub 2}/Cl{sup −} and BDD/SO{sub 4}{sup 2−} systems were better at removing the pollutant, being the former the most effective. On the other hand, pollutant degradation with the BDD/SO{sub 4}{sup 2−} and IrO{sub 2}/Cl{sup −} systems is favored at low and high current densities, respectively.

  9. Current Situation and Its Countermeasure Study for Water Resources in Hengshui City%衡水水资源现状及对策研究

    Institute of Scientific and Technical Information of China (English)

    安国庆

    2013-01-01

    在对衡水市水资源开发利用现状进行分析的基础上,总结衡水水资源的特点,分析开发利用过程中存在的问题,提出必须建立以“节流为先,治污为本,多渠道开源”的新战略;并提出从宏观和微观方面两方面优化配置水资源,改善衡水生态环境,达到水资源可持续开发利用的目的。%Based on analysis of current utilization situation of water resources in Hengshui, this article has concluded the characteristics of water resources of the city, analyzed the problems occurred during its development and utilization, and put forward a new strategy "to take reducing-water-consumptionaspriority,totakepollution-treatmentasbasicprinciple,totapnew sourcesofsupplyinmulti-channel".Thepaperputsfor-ward the optimal allocation of water resources from macroscopic view and microscopic view to improve eco-environment of Hengshui, and a-chieves the purpose of sustainable development and utilization of water resources.

  10. On Demand, Development and Dependence: A Review of Current and Future Implications of Socioeconomic Changes for Integrated Water Resource Management in the Okavango Catchment of Southern Africa

    Directory of Open Access Journals (Sweden)

    Thomas Weinzierl

    2013-02-01

    Full Text Available Water is both a key and limited resource in the Okavango Catchment of Southern Africa. It is vital for the ecosystem and the three riparian states Angola, Botswana and Namibia who use the water of the catchment for multiple purposes including pastoralism, farming and tourism. Socioeconomic changes, primarily strong population growth and increasing development demands pose significant challenges for the Okavango Catchment and its Integrated Water Resource Management (IWRM. In this paper, we first review the socioeconomic background and the current and projected water situation. Against this background, we analyze the dependence of the riparian states and the local livelihoods on the Okavango Catchment. Third, we discuss the implications of socioeconomic changes and increased water demand for the IWRM in the catchment. We review the scientific literature and relevant reports. Further we utilize (geo-spatial analysis of socioeconomic, livelihood and hydrological data, supplemented by a field visit to Namibia and Botswana. Our findings suggest that strong population growth and the stabilization of Angola are likely to increase the pressure to develop the region along the Okavango. The central challenge for IWRM is hence to enable Angola to meet its development needs without limiting livelihood and economic prospects in Botswana and Namibia.

  11. The autonomous Simpatico system for real-time continuous water-quality and current velocity monitoring: examples of application in three Portuguese estuaries

    Science.gov (United States)

    Garel, Erwan; Nunes, Susana; Neto, João Magalhães; Fernandes, Rodrigo; Neves, Ramiro; Marques, João Carlos; Ferreira, Óscar

    2009-10-01

    This technical paper describes an autonomous recording system with remote data access for the continuous, long-term in situ monitoring of water quality and discharge, as well as current velocity. The Simpatico system has been recently deployed in three estuaries in Portugal (Mondego and Tagus in July 2007; Guadiana in March 2008), highly suitable to illustrate its multifaceted potential applications: surveillance of the effects of mitigation measures to combat eutrophication (lower Mondego Estuary); real-time implementation of boundary conditions for a water modelling system (upper Tagus Estuary); study of dam-induced impacts in terms of water quality, water discharge and sediment budgets (mouth of the Guadiana Estuary). An extract of recorded data serves as an example to discuss data reliability, as well as field maintenance of the system, with implications for labour and operational costs. The use of a new generation of copper-based anti-biofouling kits significantly reduced the need for field maintenance operations. Other examples of possible application of the system include the assessment of gas accumulation in coastal waters.

  12. The water vapour continuum in near-infrared windows - Current understanding and prospects for its inclusion in spectroscopic databases

    Science.gov (United States)

    Shine, Keith P.; Campargue, Alain; Mondelain, Didier; McPheat, Robert A.; Ptashnik, Igor V.; Weidmann, Damien

    2016-09-01

    Spectroscopic catalogues, such as GEISA and HITRAN, do not yet include information on the water vapour continuum that pervades visible, infrared and microwave spectral regions. This is partly because, in some spectral regions, there are rather few laboratory measurements in conditions close to those in the Earth's atmosphere; hence understanding of the characteristics of the continuum absorption is still emerging. This is particularly so in the near-infrared and visible, where there has been renewed interest and activity in recent years. In this paper we present a critical review focusing on recent laboratory measurements in two near-infrared window regions (centred on 4700 and 6300 cm-1) and include reference to the window centred on 2600 cm-1 where more measurements have been reported. The rather few available measurements, have used Fourier transform spectroscopy (FTS), cavity ring down spectroscopy, optical-feedback - cavity enhanced laser spectroscopy and, in very narrow regions, calorimetric interferometry. These systems have different advantages and disadvantages. Fourier Transform Spectroscopy can measure the continuum across both these and neighbouring windows; by contrast, the cavity laser techniques are limited to fewer wavenumbers, but have a much higher inherent sensitivity. The available results present a diverse view of the characteristics of continuum absorption, with differences in continuum strength exceeding a factor of 10 in the cores of these windows. In individual windows, the temperature dependence of the water vapour self-continuum differs significantly in the few sets of measurements that allow an analysis. The available data also indicate that the temperature dependence differs significantly between different near-infrared windows. These pioneering measurements provide an impetus for further measurements. Improvements and/or extensions in existing techniques would aid progress to a full characterisation of the continuum - as an example, we

  13. Current Trends in Self-Emulsifying Drug Delivery Systems (SEDDSs) to Enhance the Bioavailability of Poorly Water-Soluble Drugs.

    Science.gov (United States)

    Karwal, Rohit; Garg, Tarun; Rath, Goutam; Markandeywar, Tanmay S

    2016-01-01

    The main object of the self-emulsifying drug-delivery system (SEDDS) is oral bioavailability (BA) enhancement of a poorly water-soluble drug. Low aqueous solubility and low oral BA are major concerns for formulation scientists. As many drugs are lipophilic in nature, their lower solubility and dissolution are major drawbacks for their successful formulation into oral dosage forms. More than 60% of drugs have a lipophilic nature and exhibit poor aqueous solubility. Various strategies are reported in the literature to improve the solubility and enhance BA of lipophilic drugs, including the formation of a cyclodextrin complex, solid dispersions, and micronization. SEDDSs are ideally isotropic mixtures of drug, oil, surfactant, and/or cosurfactant. SEDDSs have gained increasing attention for enhancing oral BA and reducing drug dose. SEDDSs also provide an effective and excellent solution to the various issues related to the formulation of hydrophobic drugs that have limited solubility in gastrointestinal fluid. Our major focus of this review is to highlight the importance of SEDDSs in oral BA enhancement of poorly water-soluble drugs.

  14. Response of currents and water quality to changes in dam operations in Hoover Reservoir, Columbus, Ohio, August 24–28, 2015

    Science.gov (United States)

    Vonins, Branden L.; Jackson, P. Ryan

    2017-05-25

    Hoover Reservoir, an important drinking water supply for the City of Columbus, Ohio, has been the source of a series of taste and odor problems in treated drinking water during the past few years. These taste and odor problems were caused by the compounds geosmin and 2-methylisoborneol, which are thought to have been related to cyanobacteria blooms. In an effort to reduce the phosphorus available for cyanobacteria blooms at fall turnover, the City of Columbus began experimenting with the dam’s selective withdrawal system to remove excess phosphorus in the hypolimnion, which is released from bottom sediments during summer anoxic conditions.The U.S. Geological Survey completed two synoptic survey campaigns to assess distributions of water quality and water velocity in the lower part of Hoover Reservoir to provide information on the changes to reservoir dynamics caused by changing dam operations. One campaign (campaign 1) was done while water was being withdrawn from the reservoir through the dam’s middle gate and the other (campaign 2) while water was being withdrawn through the dam’s lower gate. Velocities were measured using an acoustic Doppler current profiler, and water-quality parameters were measured using an autonomous underwater vehicle equipped with water-quality sensors. Along with the water-quality and water-velocity data, meteorological, inflow and outflow discharges, and independent water-quality data were compiled to monitor changes in other parameters that affect reservoir behavior. Monthly nutrient data, collected by the City of Columbus, were also analyzed for trends in concentration during periods of expected stratification.Based on the results of the two campaigns, when compared to withdrawing water through the middle gate, withdrawing water through the lower gate seemed to increase shear-driven mixing across the thermocline, which resulted in an increase in the depth of the epilimnion throughout the lower part of Hoover Reservoir. The

  15. Relationship between anode material, supporting electrolyte and current density during electrochemical degradation of organic compounds in water.

    Science.gov (United States)

    Guzmán-Duque, Fernando L; Palma-Goyes, Ricardo E; González, Ignacio; Peñuela, Gustavo; Torres-Palma, Ricardo A

    2014-08-15

    Taking crystal violet (CV) dye as pollutant model, the electrode, electrolyte and current density (i) relationship for electro-degrading organic molecules is discussed. Boron-doped diamond (BDD) or Iridium dioxide (IrO2) used as anode materials were tested with Na2SO4 or NaCl as electrolytes. CV degradation and generated oxidants showed that degradation pathways and efficiency are strongly linked to the current density-electrode-electrolyte interaction. With BDD, the degradation pathway depends on i: If idegraded by OH radicals, whereas if i>i(lim), generated oxidants play a major role in the CV elimination. When IrO2 was used, CV removal was not dependent on i, but on the electrolyte. Pollutant degradation in Na2SO4 on IrO2 seems to occur via IrO3; however, in the presence of NaCl, degradation was dependent on the chlorinated oxidative species generated. In terms of efficiency, the Na2SO4 electrolyte showed better results than NaCl when BDD anodes were employed. On the contrary, NaCl was superior when combined with IrO2. Thus, the IrO2/Cl(-) and BDD/SO4(2-) systems were better at removing the pollutant, being the former the most effective. On the other hand, pollutant degradation with the BDD/SO4(2-) and IrO2/Cl(-) systems is favored at low and high current densities, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Shallow water models as tool for tsunami current predictions in ports and harbors. Validation with Tohoku 2011 field data

    Science.gov (United States)

    Gonzalez Vida, J. M., Sr.; Macias Sanchez, J.; Castro, M. J.; Ortega, S.

    2015-12-01

    Model ability to compute and predict tsunami flow velocities is of importance in risk assessment and hazard mitigation. Substantial damage can be produced by high velocity flows, particularly in harbors and bays, even when the wave height is small. Besides, an accurate simulation of tsunami flow velocities and accelerations is fundamental for advancing in the study of tsunami sediment transport. These considerations made the National Tsunami Hazard Mitigation Program (NTHMP) proposing a benchmark exercise focused on modeling and simulating tsunami currents. Until recently, few direct measurements of tsunami velocities were available to compare and to validate model results. After Tohoku 2011 many current meters measurement were made, mainly in harbors and channels. In this work we present a part of the contribution made by the EDANYA group from the University of Malaga to the NTHMP workshop organized at Portland (USA), 9-10 of February 2015. We have selected three out of the five proposed benchmark problems. Two of them consist in real observed data from the Tohoku 2011 event, one at Hilo Habour (Hawaii) and the other at Tauranga Bay (New Zealand). The third one consists in laboratory experimental data for the inundation of Seaside City in Oregon. For this model validation the Tsunami-HySEA model, developed by EDANYA group, was used. The overall conclusion that we could extract from this validation exercise was that the Tsunami-HySEA model performed well in all benchmark problems proposed. The greater spatial variability in tsunami velocity than wave height makes it more difficult its precise numerical representation. The larger variability in velocities is likely a result of the behaviour of the flow as it is channelized and as it flows around bathymetric highs and structures. In the other hand wave height do not respond as strongly to chanelized flow as current velocity.

  17. Water Resources Status and Availability Assessment in Current and Future Climate Change Scenarios for Beas River Basin of North Western Himalaya

    Science.gov (United States)

    Aggarwal, S. P.; Thakur, P. K.; Garg, V.; Nikam, B. R.; Chouksey, A.; Dhote, P.; Bhattacharya, T.

    2016-10-01

    daily surface wind speed. The GFDL model also gives validation phase scenarios from 2006 to 2015, which are used to test the overall model performance with current data. The current assessment made by hydrological water balance based approach has given reasonable good results in Beas river basin. The main limitation of this study is lack of full representation of glacier melt flow using fully energy balance model. This component will be addressed in coming time and it will be integrated with tradition hydrological and snowmelt runoff models. The other limitation of current study is dependence on NCEP or other reanalysis of climate forcing data for hydrological modelling, this leads to mismatch between actual and simulated water balance components. This problem can be addressed if more ground based and fine resolution grid based hydro meteorological data are used as input forcing data for hydrological modelling.

  18. Assessing and Managing the Current and Future Pest Risk from Water Hyacinth, (Eichhornia crassipes), an Invasive Aquatic Plant Threatening the Environment and Water Security

    Science.gov (United States)

    Brunel, Sarah

    2016-01-01

    Understanding and managing the biological invasion threats posed by aquatic plants under current and future climates is a growing challenge for biosecurity and land management agencies worldwide. Eichhornia crassipes is one of the world’s worst aquatic weeds. Presently, it threatens aquatic ecosystems, and hinders the management and delivery of freshwater services in both developed and developing parts of the world. A niche model was fitted using CLIMEX, to estimate the potential distribution of E. crassipes under historical and future climate scenarios. Under two future greenhouse gas emission scenarios for 2080 simulated with three Global Climate Models, the area with a favourable temperature regime appears set to shift polewards. The greatest potential for future range expansion lies in Europe. Elsewhere in the northern hemisphere temperature gradients are too steep for significant geographical range expansion under the climate scenarios explored here. In the Southern Hemisphere, the southern range boundary for E. crassipes is set to expand southwards in Argentina, Australia and New Zealand; under current climate conditions it is already able to invade the southern limits of Africa. The opportunity exists to prevent its spread into the islands of Tasmania in Australia and the South Island of New Zealand, both of which depend upon hydroelectric facilities that would be threatened by the presence of E. crassipes. In Europe, efforts to slow or stop the spread of E. crassipes will face the challenge of limited internal biosecurity capacity. The modelling technique demonstrated here is the first application of niche modelling for an aquatic weed under historical and projected future climates. It provides biosecurity agencies with a spatial tool to foresee and manage the emerging invasion threats in a manner that can be included in the international standard for pest risk assessments. It should also support more detailed local and regional management. PMID:27513336

  19. Water

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-08-01

    Full Text Available Water scarcity is without a doubt on of the greatest threats to the human species and has all the potential to destabilise world peace. Falling water tables are a new phenomenon. Up until the development of steam and electric motors, deep groudwater...

  20. Photoelectrolysis of water at high current density - Use of laser light excitation of semiconductor-based photoelectrochemical cells

    Science.gov (United States)

    Wrighton, M. S.; Bocarsley, A. B.; Bolts, J. M.

    1978-01-01

    In the present paper, some results are given for UV laser light irradiation of the photoanode (SnO2, SrTiO3, or TiO2) in a cell for the light-driven electrolysis of H2O, at radiation intensities of up to 380 W/sq cm. The properties of the anode material are found to be independent of light intensity. Conversion of UV light to stored chemical energy in the form of 2H2/O2 from H2O was driven at a rate of up to 30 W/sq cm. High O2 evolution rates at the irradiated anodes without changes in the current-voltage curves are attributed to the excess oxidizing power associated with photogenerated holes. A test for this sort of hypothesis for H2 evolution at p-type materials is proposed.

  1. Photoelectrolysis of water at high current density - Use of laser light excitation of semiconductor-based photoelectrochemical cells

    Science.gov (United States)

    Wrighton, M. S.; Bocarsley, A. B.; Bolts, J. M.

    1978-01-01

    In the present paper, some results are given for UV laser light irradiation of the photoanode (SnO2, SrTiO3, or TiO2) in a cell for the light-driven electrolysis of H2O, at radiation intensities of up to 380 W/sq cm. The properties of the anode material are found to be independent of light intensity. Conversion of UV light to stored chemical energy in the form of 2H2/O2 from H2O was driven at a rate of up to 30 W/sq cm. High O2 evolution rates at the irradiated anodes without changes in the current-voltage curves are attributed to the excess oxidizing power associated with photogenerated holes. A test for this sort of hypothesis for H2 evolution at p-type materials is proposed.

  2. Variability of surface velocity in the Kuroshio Current and adjacent waters derived from Argos drifter buoys and satellite altimeter data

    Institute of Scientific and Technical Information of China (English)

    MA Chao; WU Dexing; LIN Xiaopei

    2009-01-01

    By combining Argos drifter buoys and TOPEX/POSEIDON altimeter data, the time series of sea-surface velocity fields in the Kuroshio Current (KC) and adjacent regions are established. And the variability of the KC from the Luzon Strait to the Tokara Strait is studied based on the velocity fields. The results show that the dominant variability period varies in different segments of the KC" The primary period near the Luzon Strait and to the east of Taiwan Island is the intra-seasonal time scale; the KC on the continental shelf of the ECS is the steadiest segment without obvious periodicity, while the Tokara Strait shows the period of seasonal variability. The diverse periods are caused by the Rossby waves propagating from the interior ocean, with adjustments in topography of island chain and local wind stress.

  3. First Measurement of the Muon Neutrino Charged Current Single Pion Production Cross Section on Water with the T2K Near Detector

    CERN Document Server

    Abe, K.

    2017-01-01

    The T2K off-axis near detector, ND280, is used to make the first differential cross section measurements of muon neutrino charged current single positive pion production on a water target at energies ${\\sim}0.8$~GeV. The differential measurements are presented as a function of muon and pion kinematics, in the restricted phase-space defined by $p_{\\pi^+}>200$MeV/c, $p_{\\mu^-}>200$MeV/c, $\\cos \\theta_{\\pi^+}>0.3$ and $\\cos \\theta_{\\mu^-}>0.3$. The total flux integrated $\

  4. Study on the Log-Linear Velocity Profile of Near-Bed Tidal Current in Estuarine and Coastal Waters

    Institute of Scientific and Technical Information of China (English)

    SONG Zhi-yao; YAN Yi-xin; HAO Jia-ling; KONG Jun; ZHANG Hong-gui

    2006-01-01

    Many observed data show that the near-bed tidal velocity profile deviates from the usual logarithmic law. The amount of deviation may not be large, but it results in large errors when the logarithmic velocity profile is used to calculate the bed roughness height and friction velocity (or shear stress). Based on their investigation, Kuo et al. (1996) indicate that the deviation amplitude may exceed 100%. On the basis of fluid dynamic principle, the profile of the near-bed tidal velocity in estuarine and coastal waters is established by introducing Prandtl's mixing length theory and Von Karman self-similarity theory. By the fitting and calculation of the near-bed velocity profile data observed in the west Solent, England, the results are compared with those of the usual logarithmic model, and it is shown that the present near-bed tidal velocity profile model has such advantages as higher fitting precision, and better inner consistency between the roughness height and friction velocity. The calculated roughness height and friction velocity are closer to reality. The conclusions are validated that the logarithmic model underestimates the roughness height and friction velocity during tidal acceleration and overestimates them during tidal deceleration.

  5. Current knowledge of the Tardigrada of Svalbard with the first records of water bears from Nordaustlandet (High Arctic

    Directory of Open Access Journals (Sweden)

    Krzysztof Zawierucha

    2013-11-01

    Full Text Available The first investigations of the tardigrades of Svalbard took place in the early 20th century and 30 papers on the subject have been published to date. In this article, we summarize available information on the distribution of tardigrades in this Arctic archipelago with remarks on the dubious species and records. Additionally, we examined 28 new moss, lichen and soil samples collected from the islands of Nordaustlandet, Edgeøya and Prins Karls Forland. These samples yielded 324 specimens, 15 exuvia and 132 free-laid eggs belonging to 16 limnoterrestrial species (Heterotardigrada and Eutardigrada. These include five first records of water bears from Nordaustlandet, eight new records for Edgeøya and four for Prince Karls Forland. The most dense population of tardigrades was found in a sample with 253 specimens/10 g of dry material and the least dense population in a sample with three specimens/10 g of dry material. The most frequently recorded species in samples collected in this study were Testechiniscus spitsbergensis Scourfield, 1897, Macrobiotus harmsworthi harmsworthi Murray, 1907, and M. islandicus islandicus Richters, 1904. This article also provides the first ever scanning electron microscope photomicrographs of Tenuibiotus voronkovi Tumanov, 2007.

  6. Adaptive Comanagement in the Venice Lagoon? An Analysis of Current Water and Environmental Management Practices and Prospects for Change

    Directory of Open Access Journals (Sweden)

    Stefania Munaretto

    2012-06-01

    Full Text Available Adaptive comanagement (ACM is often suggested as a way of handling the modern challenges of environmental governance, which include uncertainty and complexity. ACM is a novel combination of the learning dimension of adaptive management and the linkage dimension of comanagement. As has been suggested, there is a need for more insight on enabling policy environments for ACM success and failure. Picking up on this agenda we provide a case study of the world famous Venice lagoon in Italy. We address the following questions: first, to what extent are four institutional prescriptions typically associated with ACM currently practiced in the Venice system? Second, to what extent is learning taking place in the Venice system? Third, how is learning related to the implementation or nonimplementation of the prescriptions of ACM in the Venice system? Our analysis is based on interviews with stakeholders, participatory observation, and archive data. This paper demonstrates that the prescriptions of ACM are hardly followed in the Venice lagoon, but some levels of cognitive learning do take place, albeit very much within established management paradigms. Normative and relational learning are much rarer and when they do occur, they seem to have a relatively opportunistic reason. We propose that in particular the low levels of collaboration, because the governance system was deliberately set up in a hierarchical and mono-centric way, and the limited possibilities for stakeholder participation are implicated in this finding because they cause low levels of social capital and an incapacity to handle disagreements and uncertainty very well.

  7. Water

    Directory of Open Access Journals (Sweden)

    E. Sanmuga Priya

    2017-05-01

    Full Text Available Phytoremediation through aquatic macrophytes treatment system (AMATS for the removal of pollutants and contaminants from various natural sources is a well established environmental protection technique. Water hyacinth (Eichhornia crassipes, a worst invasive aquatic weed has been utilised for various research activities over the last few decades. The biosorption capacity of the water hyacinth in minimising various contaminants present in the industrial wastewater is well studied. The present review quotes the literatures related to the biosorption capacity of the water hyacinth in reducing the concentration of dyestuffs, heavy metals and minimising certain other physiochemical parameters like TSS (total suspended solids, TDS (total dissolved solids, COD (chemical oxygen demand and BOD (biological oxygen demand in textile wastewater. Sorption kinetics through various models, factors influencing the biosorption capacity, and role of physical and chemical modifications in the water hyacinth are also discussed.

  8. Geohydrologic Investigations and Landscape Characteristics of Areas Contributing Water to Springs, the Current River, and Jacks Fork, Ozark National Scenic Riverways, Missouri

    Science.gov (United States)

    Mugel, Douglas N.; Richards, Joseph M.; Schumacher, John G.

    2009-01-01

    The Ozark National Scenic Riverways (ONSR) is a narrow corridor that stretches for approximately 134 miles along the Current River and Jacks Fork in southern Missouri. Most of the water flowing in the Current River and Jacks Fork is discharged to the rivers from springs within the ONSR, and most of the recharge area of these springs is outside the ONSR. This report describes geohydrologic investigations and landscape characteristics of areas contributing water to springs and the Current River and Jacks Fork in the ONSR. The potentiometric-surface map of the study area for 2000-07 shows that the groundwater divide extends beyond the surface-water divide in some places, notably along Logan Creek and the northeastern part of the study area, indicating interbasin transfer of groundwater between surface-water basins. A low hydraulic gradient occurs in much of the upland area west of the Current River associated with areas of high sinkhole density, which indicates the presence of a network of subsurface karst conduits. The results of a low base-flow seepage run indicate that most of the discharge in the Current River and Jacks Fork was from identified springs, and a smaller amount was from tributaries whose discharge probably originated as spring discharge, or from springs or diffuse groundwater discharge in the streambed. Results of a temperature profile conducted on an 85-mile reach of the Current River indicate that the lowest average temperatures were within or downstream from inflows of springs. A mass-balance on heat calculation of the discharge of Bass Rock Spring, a previously undescribed spring, resulted in an estimated discharge of 34.1 cubic feet per second (ft3/s), making it the sixth largest spring in the Current River Basin. The 13 springs in the study area for which recharge areas have been estimated accounted for 82 percent (867 ft3/s of 1,060 ft3/s) of the discharge of the Current River at Big Spring during the 2006 seepage run. Including discharge from

  9. Towards Sustaining Water Resources and Aquatic Ecosystems: Forecasting Watershed Risks to Current and Future Land Use Change

    Science.gov (United States)

    Lohse, K. A.; Newburn, D.; Opperman, J. J.; Brooks, C.; Merenlender, A.

    2005-05-01

    Sustaining aquatic resources requires managing existing threats and anticipating future impacts. Resource managers and planners often have limited understanding of the relative effects of human activities on stream conditions and how these effects will change over time. Here we assess and forecast the relative impacts of land use on sediment concentrations in Mediterranean-climate watersheds in California. We focus on the Russian River basin, which supports threatened salmonid populations vulnerable to high levels of fine sediment. We ask the following questions: (1) What are the relative impacts of three different land uses (urban, exurban and agriculture) on the patterns of fine sediment in streams? (2) What is the relative contribution of past and current changes in land use activities on these patterns? and (3) What are the effects of future development on these sediment levels? First, we characterized land use at the parcel scale to calibrate the relative impacts of exurban and urban land use on stream substrate quality, characterized by the concentration of fine sediment surrounding spawning gravels (`embeddedness') in 105 stream reaches. Second, we built multiple ordinal logistic regression models on a subset of watersheds (n=64) and then evaluated substrate quality predictions against observed data from another set of watersheds (n=41). Finally, we coupled these models with spatially explicit land use change models to project future stream conditions and associated uncertainties under different development scenarios for the year 2010. We found that the percent of urban housing and agriculture were significant predictors of in-stream embeddedness. Model results from parcel-level land use data indicated that changes in development were better predictors of fine sediment than total development in a single time period. In addition, our results indicate that exurban development is an important threat to stream systems; increases in the percent of total exurban

  10. Measurement of the Electron Neutrino Charged-current Interaction Rate on Water with the T2K ND280 pi-zero Detector

    CERN Document Server

    Abe, K; Aihara, H; Andreopoulos, C; Aoki, S; Ariga, A; Assylbekov, S; Autiero, D; Barbi, M; Barker, G J; Barr, G; Bartet-Friburg, P; Bass, M; Batkiewicz, M; Bay, F; Berardi, V; Berger, B E; Berkman, S; Bhadra, S; Blaszczyk, F d M; Blondel, A; Bolognesi, S; Bordoni, S; Boyd, S B; Brailsford, D; Bravar, A; Bronner, C; Buchanan, N; Calland, R G; Caravaca, J; Cartwright, S L; Castillo, R; Catanesi, M G; Cervera, A; Cherdack, D; Christodoulou, G; Clifton, A; Coleman, J; Coleman, S J; Collazuol, G; Connolly, K; Cremonesi, L; Dabrowska, A; Das, R; Davis, S; de, P; De, G; Dealtry, T; Dennis, S R; Densham, C; Dewhurst, D; Di, F; Di, S; Dolan, S; Drapier, O; Duffy, K; Dumarchez, J; Dytman, S; Dziewiecki, M; Emery-Schrenk, S; Ereditato, A; Escudero, L; Feusels, T; Finch, A J; Fiorentini, G A; Friend, M; Fujii, Y; Fukuda, Y; Furmanski, A P; Galymov, V; Garcia, A; Giffin, S; Giganti, C; Gilje, K; Goeldi, D; Golan, T; Gonin, M; Grant, N; Gudin, D; Hadley, D R; Haegel, L; Haesler, A; Haigh, M D; Hamilton, P; Hansen, D; Hara, T; Hartz, M; Hasegawa, T; Hastings, N C; Hayashino, T; Hayato, Y; Helmer, R L; Hierholzer, M; Hignight, J; Hillairet, A; Himmel, A; Hiraki, T; Hirota, S; Holeczek, J; Horikawa, S; Huang, K; Ichikawa, A K; Ieki, K; Ieva, M; Ikeda, M; Imber, J; Insler, J; Irvine, T J; Ishida, T; Ishii, T; Iwai, E; Iwamoto, K; Iyogi, K; Izmaylov, A; Jacob, A; Jamieson, B; Jiang, M; Johnson, S; Jo, J H; Jonsson, P; Jung, C K; Kabirnezhad, M; Kaboth, A C; Kajita, T; Kakuno, H; Kameda, J; Kanazawa, Y; Karlen, D; Karpikov, I; Katori, T; Kearns, E; Khabibullin, M; Khotjantsev, A; Kielczewska, D; Kikawa, T; Kilinski, A; Kim, J; King, S; Kisiel, J; Kitching, P; Kobayashi, T; Koch, L; Koga, T; Kolaceke, A; Konaka, A; Kormos, L L; Korzenev, A; Koshio, Y; Kropp, W; Kubo, H; Kudenko, Y; Kurjata, R; Kutter, T; Lagoda, J; Lamont, I; Larkin, E; Laveder, M; Lawe, M; Lazos, M; Lindner, T; Lister, C; Litchfield, R P; Longhin, A; Lopez, J P; Ludovici, L; Magaletti, L; Mahn, K; Malek, M; Manly, S; Marino, A D; Marteau, J; Martin, J F; Martins, P; Martynenko, S; Maruyama, T; Matveev, V; Mavrokoridis, K; Mazzucato, E; McCarthy, M; McCauley, N; McFarland, K S; McGrew, C; Mefodiev, A; Metelko, C; Mezzetto, M; Mijakowski, P; Miller, C A; Minamino, A; Mineev, O; Missert, A; Miura, M; Moriyama, S; Mueller, Th A; Murakami, A; Murdoch, M; Murphy, S; Myslik, J; Nakadaira, T; Nakahata, M; Nakamura, K G; Nakamura, K; Nakayama, S; Nakaya, T; Nakayoshi, K; Nantais, C; Nielsen, C; Nirkko, M; Nishikawa, K; Nishimura, Y; Nowak, J; O'Keeffe, H M; Ohta, R; Okumura, K; Okusawa, T; Oryszczak, W; Oser, S M; Ovsyannikova, T; Owen, R A; Oyama, Y; Palladino, V; Palomino, J L; Paolone, V; Payne, D; Perevozchikov, O; Perkin, J D; Petrov, Y; Pickard, L; Pinzon, E S; Pistillo, C; Plonski, P; Poplawska, E; Popov, B; Posiadala-Zezula, M; Poutissou, J -M; Poutissou, R; Przewlocki, P; Quilain, B; Radicioni, E; Ratoff, P N; Ravonel, M; Rayner, M A M; Redij, A; Reeves, M; Reinherz-Aronis, E; Riccio, C; Rodrigues, P A; Rojas, P; Rondio, E; Roth, S; Rubbia, A; Ruterbories, D; Rychter, A; Sacco, R; Sakashita, K; S, F; Sato, F; Scantamburlo, E; Scholberg, K; Schoppmann, S; Schwehr, J; Scott, M; Seiya, Y; Sekiguchi, T; Sekiya, H; Sgalaberna, D; Shah, R; Shaker, F; Shaw, D; Shiozawa, M; Short, S; Shustrov, Y; Sinclair, P; Smith, B; Smy, M; Sobczyk, J T; Sobel, H; Sorel, M; Southwell, L; Stamoulis, P; Steinmann, J; Suda, Y; Suzuki, A; Suzuki, K; Suzuki, S Y; Suzuki, Y; Tacik, R; Tada, M; Takahashi, S; Takeda, A; Takeuchi, Y; Tanaka, H K; Tanaka, H A; Tanaka, M M; Terhorst, D; Terri, R; Thompson, L F; Thorley, A; Tobayama, S; Toki, W; Tomura, T; Totsuka, Y; Touramanis, C; Tsukamoto, T; Tzanov, M; Uchida, Y; Vacheret, A; Vagins, M; Vasseur, G; Wachala, T; Wakamatsu, K; Walter, C W; Wark, D; Warzycha, W; Wascko, M O; Weber, A; Wendell, R; Wilkes, R J; Wilking, M J; Wilkinson, C; Williamson, Z; Wilson, J R; Wilson, R J; Wongjirad, T; Yamada, Y; Yamamoto, K; Yanagisawa, C; Yano, T; Yen, S; Yershov, N; Yokoyama, M; Yoshida, K; Yuan, T; Yu, M; Zalewska, A; Zalipska, J; Zambelli, L; Zaremba, K; Ziembicki, M; Zimmerman, E D; Zito, M; Zmuda, J

    2015-01-01

    The first direct observation of the appearance of electron neutrinos in a muon neutrino beam through neutrino oscillation was recently reported by the T2K experiment. The main background in this observation was the presence of the electron neutrino component of the beam, which accounts for 1.2 % of the beam below the 1.2 GeV threshold. This paper presents a measurement of the charged current interaction rate of the electron neutrino beam component using the large fiducial mass of the T2K $\\pi^0$ detector. The measured ratio of the observed beam interaction rate to the predicted rate in the detector with water targets filled is 0.89 $\\pm$ 0.08 (stat.) $\\pm$ 0.11 (sys.), and with the water targets emptied is 0.90 $\\pm$ 0.09 (stat.) $\\pm$ 0.13 (sys.). The ratio obtained for the interactions on water only from an event subtraction method is 0.87 $\\pm$ 0.33 (stat.) $\\pm$ 0.21 (sys.). These are pioneering measurements of the $\

  11. User requirements and user acceptance of current and next-generation satellite mission and sensor complement, oriented toward the monitoring of water resources

    Science.gov (United States)

    Castruccio, P. A.; Loats, H. L., Jr.; Fowler, T. R.; Robinson, P.

    1975-01-01

    Principal water resources users were surveyed to determine the applicability of remotely sensed data to their present and future requirements. Analysis of responses was used to assess the levels of adequacy of LANDSAT 1 and 2 in fulfilling hydrological functions, and to derive systems specifications for future water resources-oriented remote sensing satellite systems. The analysis indicates that water resources applications for all but the very large users require: (1) resolutions on the order of 15 meters, (2) a number of radiometric levels of the same order as currently used in LANDSAT 1 (64), (3) a number of spectral bands not in excess of those used in LANDSAT 1, and (4) a repetition frequency on the order of 2 weeks. The users had little feel for the value of new sensors (thermal IR, passive and active microwaves). What is needed in this area is to achieve specific demonstrations of the utility of these sensors and submit the results to the users to evince their judgement.

  12. Municipal asset management or mismanagement? A six ‘Whats’ perspective on current practices and challenges in Ethiopia’s urban water sector

    Directory of Open Access Journals (Sweden)

    Tendayi GONDO

    2010-06-01

    Full Text Available Effective systems of asset management can strengthen the performance of a local economy and community significantly. Despite the existence of new and interactive technologies for recording and communicating assets and asset management, many local authorities across the developing world have not taken advantage of the emerging revolutionary ways in which technologies may benefit municipal asset management. The analysis reviews the current practices, challenges and policy options for Ethiopian cities with regard to the state of the art technology for Municipal Asset Management (MAM in the water and sanitation sector. Empirical evidence relate to a number of independent studies carried out in a sample of Ethiopian cities and towns. The pooling together of these findings was achieved through the Comparative Studies framework. In addition, data was also solicited from a panel of experts dealing with water and sanitation issues. The overall analysis was done within the context of the six Whats? Framework. Results indicate that, the water sector has gone through a number of reforms that have not cascaded into improved infrastructure asset management. Lack of financial resources, human resource expertise and appropriate organizational strategy has constrained the adoption and application of system software for effective asset management.

  13. Preparation of salvianolic acid A by the degradation reaction of salvianolic acid B in subcritical water integrated with pH-zone-refining counter-current chromatography.

    Science.gov (United States)

    Li, Huaizhi; Cheng, Yan; Dong, Hongjing; Wang, Xiao; Li, Jia; Gao, Qianshan

    2016-10-14

    Salvianolic acid A is the major bioactive compound in Danshen, however, due to the chemical instability and low content in Danshen, it is difficult to extract amount of salvianolic acid A. Therefore, this study was to establish an effective strategy for obtaining adequate amount of salvianolic acid A, subcritical water extraction was used to degrade salvianolic acid B and prepare salvianolic acid A. Different reaction conditions including temperature, time, concentration and pH value in subcritical water were investigated. Under 40mg/mL of reactant concentration, 180°C of temperature, 4.0 of pH value and 60min of reaction time, the highest yield rate of salvianolic acid A reached 34.86%. Then, the degradation products were successfully separated by pH-zone-refining counter-current chromatography with the solvent system Pet-EtAc-n-BuOH-H2O (2:3:1:9, v/v), where 10mM TFA was added in stationary phase and 10mM NH3·H2O in mobile phase. As a result, a total of 227.3mg of salvianolic acid A at 98.2% purity, 38.9mg of danshensu at 99.3% purity, 9.5mg of salvianolic acid D at 92.7% purity, and 32.8mg of protocatechuic aldehyde at 93.1% purity were obtained from 1.2g degradation products of salvianolic acid B by one-step purification. The results demonstrated that the combinative application of subcritical water and pH-zone-refining counter-current chromatography is a potential technique for the preparative separation of salvianolic acid A from salvianolic acid B.

  14. New direct estimates of Iceland-Scotland Overflow Water transport through the Charlie-Gibbs Fracture Zone and its relationship to the North Atlantic Current

    Science.gov (United States)

    Bower, Amy; Furey, Heather; Xu, Xiaobiao

    2015-04-01

    Detailed observations of the pathways, transports and water properties of dense overflows associated with the Atlantic Meridional Overturning Circulation (AMOC) provide critical benchmarks for climate models and mixing parameterizations. A recent two-year time series from eight moorings offers the first long-term simultaneous observations of the hydrographic properties and transport of Iceland-Scotland Overflow Water (ISOW) flowing westward through the Charlie-Gibbs Fracture Zone (CGFZ), a major deep gap in the Mid-Atlantic Ridge (MAR) connecting the eastern and western basins of the North Atlantic. In addition, current meters up to 500-m depth and satellite altimetry allow us to investigate the overlying North Atlantic Current (NAC) as a source of ISOW transport variability. Using the isohaline 34.94 to define the ISOW layer, the two year mean and standard deviation of ISOW transport was -1.7 ± 1.5 Sv, compared to -2.4 ± 3.0 Sv reported by Saunders for a 13-month period in 1988-1989 using the same isohaline. Differences in the two estimates are partly explained by limitations of the Saunders array, but more importantly reflect the strong low-frequency variability in ISOW transport through CGFZ (which includes complete reversals). Both the observations and output from a multi-decadal simulation of the North Atlantic using the Hybrid Coordinate Ocean Model (HYCOM) forced with interannually varying wind and buoyancy fields indicate a strong positive correlation between ISOW transport and the strength of the NAC through the CGFZ. This result raises new questions regarding the interaction of the upper and lower limbs of the AMOC, downstream propagation of ISOW transport variability in the Deep Western Boundary Current and alternative pathways of ISOW across the MAR.

  15. Slow-rise and fast-drop current feature of ultraviolet response spectra for ZnO-nanowire film modulated by water molecules

    Institute of Scientific and Technical Information of China (English)

    Ren Shou-Tian; Wang Qiang; Zhao Feng; Qu Shi-Liang

    2012-01-01

    This study describes the fabrication of ZnO-nanowire films by electro-chemical anodization of Zn foil.The ZnO films are characterized by field emission scanning electron microscopy,X-ray diffraction patterns,and transmission electron microscopy,respectively.The ultraviolet (UV) photo-response properties of the surface-contacted ZnO film are studied through the current evolution processes under different relative humidities.Unlike the usually observed current spectra of the ZnO films,the drop time is shorter than the rise time.The photo-conductivity gain G and the response time γ are both increased with the increase of the applied bias.The photo-conductivity gain G is lowered with the increase of the environmental humidity,while the response time γ is increased.These results can be explained by considering three different surface processes:1) the electron-hole (e-p) pair generation by the UV light illumination,2)the following surface (O-2) species desorption,and 3) the photo-catalytic hydrolysis of water molecules adsorbed on the ZnO surface.The slow-rise and fast-drop current feature is suggested to originate from the sponge-like structure of the ZnO nanowires.

  16. Charge inversion, water splitting, and vortex suppression due to DNA sorption on ion-selective membranes and their ion-current signatures.

    Science.gov (United States)

    Slouka, Zdenek; Senapati, Satyajyoti; Yan, Yu; Chang, Hsueh-Chia

    2013-07-02

    The physisorption of negatively charged single-stranded DNA (ssDNA) of different lengths onto the surface of anion-exchange membranes is sensitively shown to alter the anion flux through the membrane. At low surface concentrations, the physisorbed DNAs act to suppress an electroconvection vortex instability that drives the anion flux into the membrane and hence reduce the overlimiting current through the membrane. Beyond a critical surface concentration, determined by the total number of phosphate charges on the DNA, the DNA layer becomes a cation-selective membrane, and the combined bipolar membrane has a lower net ion flux, at low voltages, than the original membrane as a result of ion depletion at the junction between the cation- (DNA) and anion-selective membranes. However, beyond a critical voltage that is dependent on the ssDNA coverage, water splitting occurs at the junction to produce a larger overlimiting current than that of the original membrane. These two large opposite effects of polyelectrolyte counterion sorption onto membrane surfaces may be used to eliminate limiting current constraints of ion-selective membranes for liquid fuel cells, dialysis, and desalination as well as to suggest a new low-cost membrane surface assay that can detect and quantify the number of large biomolecules captured by probes functionalized on the membrane surface.

  17. Institutional and legal arrangements in the Nile river basin: suggestions to improve the current situation toward adaptive integrated water resources management.

    Science.gov (United States)

    Abdalla, Khalid Mohamed El Hassan

    2008-01-01

    A comparative study was conducted in this work in order to investigate the current situation in the Nile river basin (NRB) regarding the institutional and legal arrangements needed to support the adaptive integrated water resources management (AIWRM) strategy. Two similar river basins were selected to achieve this comparison and to introduce suggestions to reform the current situation in the basin. Before that, the ideal situation is investigated to be as a yardstick for the desired situation. The study indicated that the necessary AIWRM criteria may include regulatory as well as implementation organizations that support shared-vision reaching with its all necessary features (cooperation, stakeholders' participation, subsidiarity, and information and knowledge exchange). Thus the main features of the desired situations regarding AIWRM in river basins are stakeholders' participation, learning-driven ability, quick response to risks and uncertainties, and finally a legal framework that could support these criteria. Although the AIWRM criteria seem to be satisfied in NRB, the basin lacks the necessary regulatory institutions as well as the legal framework. According to this, this study recommends to reform the current situation in NRB by creating regulator institutions (policy and decision making level) as well a legal framework to legitimate them.

  18. Physical, chemical, current profile, water pressure, sea surface temperature, meteorological, and other data from current meters, bottle casts, pressure gauges, meteorological sensors, current meters, and other instruments from the ANDRE NIZERY and other platforms from the TOGA Area - Atlantic as part of the Seasonal Response of the Equatorial Atlantic Experiment/Francais Ocean Et Climat Dans L'Atlantique Equatorial (SEQUAL/FOCAL) project from 01 January 1964 to 31 December 1985 (NODC Accession 8700150)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, chemical, current profile, water pressure, sea surface temperature, meteorological, and other data were collected from the ANDRE NIZERY and other platforms...

  19. Water physics and chemistry data from moored current meter and bottle casts in the Northwest Atlantic Ocean as part of the North East Monitoring Program (NEMP) project, 03 June 1981 - 09 June 1981 (NODC Accession 8100724)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Northwest Atlantic Ocean from June 3, 1981 to June 9, 1981. Data...

  20. Water physics and chemistry data from moored current meter and bottle casts in the Northwest Atlantic Ocean as part of the North East Monitoring Program (NEMP) project, 27 July 1982 - 02 August 1982 (NODC Accession 8400002)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Northwest Atlantic Ocean from July 27, 1982 to August 2, 1982....

  1. Water physics and chemistry data from moored current meter and bottle casts in the Northwest Atlantic Ocean as part of the North East Monitoring Program (NEMP) project, 15 April 1981 - 20 April 1981 (NODC Accession 8100656)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Northwest Atlantic Ocean from April 15, 1981 to April 20, 1981....

  2. Water physical and chemical data from current meter and bottle casts from the COLUMBUS ISELIN as part of the Ocean Continental Shelf - Mid Atlantic (OCS - Mid Atlantic) project, 27 October 1975 - 06 November 1975 (NODC Accession 7700454)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physical and chemical data were collected using current meter and bottle casts from the COLUMBUS ISELIN from October 27, 1975 to November 6, 1975. Data were...

  3. Water physics and chemistry data from moored current meter and bottle casts in the Gulf of Mexico as part of the Brine Disposal project, 04 December 1979 - 11 June 1980 (NODC Accession 8000476)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Gulf of Mexico from December 4, 1979 to June 11, 1980. Data were...

  4. Water physical and chemical data from current meter and bottle casts from the GILLISS as part of the Ocean Continental Shelf - Mid Atlantic (OCS - Mid Atlantic) project, 04 February 1976 - 14 September 1976 (NODC Accession 7700477)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physical and chemical data were collected using current meter and bottle casts from the GILLISS and other platforms from February 4, 1976 to September 14,...

  5. Water physical and chemical data from current meter and bottle casts from the G.W. PIERCE as part of the Ocean Continental Shelf - Mid Atlantic (OCS - Mid Atlantic) project, 22 October 1975 - 31 October 1975 (NODC Accession 8200067)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physical and chemical data were collected using current meter and bottle casts from the G.W. PIERCE from October 22, 1975 to October 31, 1975. Data were...

  6. Water physics and chemistry data from moored current meter and bottle casts in the Northwest Atlantic Ocean as part of the North East Monitoring Program (NEMP) project, 02 September 1980 - 06 September 1980 (NODC Accession 8100628)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Northwest Atlantic Ocean from September 2, 1980 to September 6,...

  7. Water physics and chemistry data from moored current meter and bottle casts in the Northwest Atlantic Ocean as part of the North East Monitoring Program (NEMP) project, 28 May 1982 - 04 June 1982 (NODC Accession 8300008)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Northwest Atlantic Ocean from May 28, 1982 to June 4, 1982. Data...

  8. Chemical data from moored current meter, bottle casts, and other instruments in the Coastal Waters of New Jersey as part of the Mesa New York Bight (MESA - NYB) project, 18 May 1978 - 19 October 1978 (NODC Accession 7900280)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical data were collected using moored current meter, bottle casts, and other instruments in the Coastal Waters of New Jersey from May 18, 1978 to October 19,...

  9. Water physics and chemistry data from moored current meter and bottle casts in the New York Bight as part of the North East Monitoring Program (NEMP) project, 10 April 1984 - 31 October 1984 (NODC Accession 8500225)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the New York Bight from April 10, 1984 to October 31, 1984. Data were...

  10. Current and other data from meters attached to FIXED PLATFORMS in the coastal waters of Florida in support of the Subtropical Atlantic Climate Study 3 (STACS) from 10 November 1980 to 07 June 1983 (NODC Accession 8800120)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current and other data from meters attached to FIXED PLATFORMS in the coastal waters of Florida. Data were collected by University of Miami; Rosenstiel School of...

  11. Current and other data from meters attached to FIXED PLATFORMS in the coastal waters of Florida in support of the Subtropical Atlantic Climate Study 4 (STACS) from 08 June 1983 to 13 December 1983 (NODC Accession 8700019)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current and other data from meters attached to FIXED PLATFORMS in the coastal waters of Florida. Data were collected by University of Miami; Rosenstiel School of...

  12. Current and other data from meters attached to FIXED PLATFORMS in the coastal waters of Florida in support of the Subtropical Atlantic Climate Study 6 (STACS) from 19 June 1984 to 27 March 1987 (NODC Accession 8900060)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current and other data from meters attached to FIXED PLATFORMS in the coastal waters of Florida. Data were collected by University of Miami; Rosenstiel School of...

  13. CTD, current meter, pressure gauge, and wave spectra data from fixed platforms and other platforms from the Coastal Waters of California as part of the Santa Barbara Channel project from 27 April 1983 to 04 January 1985 (NODC Accession 8500177)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD, current meter, pressure gauge, and wave spectra data were collected from fixed platforms and other platforms from the Coastal Waters of California from 27 April...

  14. Water physics and chemistry data from moored current meter and bottle casts in the Northwest Atlantic Ocean as part of the North East Monitoring Program (NEMP) project, 21 April 1980 - 18 July 1980 (NODC Accession 8100501)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physics and chemistry data were collected using moored current meter and bottle casts in the Northwest Atlantic Ocean from April 21, 1980 to July 18, 1980....

  15. Research in Water Permeability of Poly(ethylene) Terephthalate Track Membranes Modified by Polymerization of Dimethylaniline under the Action of Direct Current Discharge

    CERN Document Server

    Kravets, L I; Drachev, A I

    2004-01-01

    The properties of poly(ethylene) terephthalate track membranes modified by polymerization of dimethylaniline in a discharge of direct current are investigated. The influence of conditions of plasma treatment on the basic characteristics of the membranes (pore size, wettability, surface charge, water permeability) is studied. It is shown that under the action of discharge, a polymeric layer is formed on the membrane surface that can swell in solutions with low pH values. It has been found that the degree of the swelling stipulated by the conformation transfer of macromolecules of the deposited polymeric layer depends upon the size of relative magnification of the mass of the membrane during its plasma treatment. It is also shown that the obtained membranes can reversibly react to changing the pH of solution and applied pressure.

  16. Temperature profile, current, pressure, physical, and other data from XBT casts, current meters, pressure gauges, and CTD casts from the VEGA I and other platforms from the Coastal Waters of California and other locations as part of the Central California Circulation Study from 1984-01-31 to 1985-07-01 (NCEI Accession 8700197)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile, current, pressure, physical, and other data from the VEGA I and other platforms from the Coastal Waters of California and other locations from...

  17. Treating waste waters in small agglomerations. The current situation, commitments and alternatives; Depuracion de las aguas residuales en pequenos nuclear. Situacion actual, compromisos y alternativas

    Energy Technology Data Exchange (ETDEWEB)

    Collado Lara, R. [Universidad de Cantabria. (Spain)

    2003-07-01

    In 1991, the European Economic Community issued a directive on urban waste water treatment: (91/27/EEC). This directive laid down that such treatment had to be in place ny the period 2000-2005, depending on the application of different requirements according to the size of the agglomeration and the discharge area. A large number of sewage plants are being built in Spain at the present time, especially in medium-size and large agglomeration (pop>10.000 inhabitants). However, in the smaller agglomeration, over 50% of the waste waters have still to be treated. In agglomerations of less than 10.000 inhabitants, which make up 95% of the municipalities in Spain, it is possible to apply a greater diversity of treatments not all of them conventional that comply with the directive in question. Natural systems and biofilm processes are low-cost solutions that are well adapted to the natural environment. However, conventional technologies are virtually essential in medium-size and large agglomerations, as the lack of space and the exacting demands render them irreplaceable (Collado, 2002). This article describes the distribution of the municipalities in Spain according to the number of inhabitants, the current state os sewage treatment,the commitments made by the European Economic Community and the viable alternatives. Some comments have been added regarding the running of such systems and the need for them to be managed by associations of local councils or regional bodies. (Author)

  18. Detailed electrochemical studies of the tetraruthenium polyoxometalate water oxidation catalyst in acidic media: identification of an extended oxidation series using Fourier transformed alternating current voltammetry.

    Science.gov (United States)

    Lee, Chong-Yong; Guo, Si-Xuan; Murphy, Aidan F; McCormac, Timothy; Zhang, Jie; Bond, Alan M; Zhu, Guibo; Hill, Craig L; Geletii, Yurii V

    2012-11-05

    The electrochemistry of the water oxidation catalyst, Rb(8)K(2)[{Ru(4)O(4)(OH)(2)(H(2)O)(4)}(γ-SiW(10)O(36))(2)] (Rb(8)K(2)-1(0)) has been studied in the presence and absence of potassium cations in both hydrochloric and sulfuric acid solutions by transient direct current (dc) cyclic voltammetry, a steady state dc method in the rotating disk configuration and the kinetically sensitive technique of Fourier transformed large-amplitude alternating current (ac) voltammetry. In acidic media, the presence of potassium ions affects the kinetics (apparent rate of electron transfer) and thermodynamics (reversible potentials) of the eight processes (A'/A to H/H') that are readily detected under dc voltammetric conditions. The six most positive processes (A'/A to F/F'), each involve a one electron ruthenium based charge transfer step (A'/A, B'/B are Ru(IV/V) oxidation and C/C' to F/F' are Ru(IV/III) reduction). The apparent rate of electron transfer of the ruthenium centers in sulfuric acid is higher than in hydrochloric acid. The addition of potassium cations increases the apparent rates and gives rise to a small shift of reversible potential. Simulations of the Fourier transformed ac voltammetry method show that the B'/B, E/E', and F/F' processes are quasi-reversible, while the others are close to reversible. A third Ru(IV/V) oxidation process is observed just prior to the positive potential limit via dc methods. Importantly, the ability of the higher harmonic components of the ac method to discriminate against the irreversible background solvent process allows this (process I) as well as an additional fourth reversible ruthenium based process (J) to be readily identified. The steady-state rotating disk electrode (RDE) method confirmed that all four Ru-centers in Rb(8)K(2)-1(0) are in oxidation state IV. The dc and ac data indicate that reversible potentials of the four ruthenium centers are evenly spaced, which may be relevant to understanding of the water oxidation

  19. Formation of the Martian Polar Layered Terrains: Quantifying Polar Water Ice and Dust Surface Deposition during Current and Past Orbital Epochs with the NASA Ames GCM

    Science.gov (United States)

    Emmett, Jeremy; Murphy, Jim

    2016-10-01

    Structural and compositional variability in the layering sequences comprising Mars' polar layered terrains (PLT's) is likely explained by orbital-forced climatic variations in the sedimentary cycles of water ice and dust from which they formed [1]. The PLT's therefore contain a direct, extensive record of the recent climate history of Mars encoded in their structure and stratigraphy, but deciphering this record requires understanding the depositional history of their dust and water ice constituents. 3D Mars atmosphere modeling enables direct simulation of atmospheric dynamics, aerosol transport and quantification of surface accumulation for a range of past and present orbital configurations. By quantifying the net yearly polar deposition rates of water ice and dust under Mars' current and past orbital configurations characteristic of the last several millions of years, and integrating these into the present with a time-stepping model, the formation history of the north and south PLT's will be investigated, further constraining their age and composition, and, if reproducible, revealing the processes responsible for prominent features and stratigraphy observed within the deposits. Simulating the formation of the deposits by quantifying net deposition rates during past orbital epochs and integrating these into the present, effectively 'rebuilding' the terrains, could aid in understanding deeper stratigraphic trends, correlating between geographically-separated deposits, explaining the presence and shapes of large-scale polar features, and correlating stratigraphy with geological time. Quantification of the magnitude and geographical distribution of surface aerosol accumulation will build on the work of previous GCM-based investigations [3]. Construction and analysis of hypothetical stratigraphic sequences in the PLT's will draw from previous climate-controlled stratigraphy methodologies [2,4], but will utilize GCM-derived net deposition rates to model orbital

  20. The flora and fauna associated with Himanthalia elongata (L.) S. F. Gray in relation to water current and wave action in the Lough Hyne marine nature reserve*1

    Science.gov (United States)

    Kitching, J. A.

    1987-12-01

    The growth of epiphytes (plant and animal) was investigated at various stages in the development of the low littoral alga Himanthalia elongata. The vegetative thallus, or button, is very resistant to the settlement of epiphytes on its upper surface, but susceptible to extensive coverage on its lower surface and stalk, especially by Bryozoa and spirorbid worms. The receptacles or straps are invaded by a microforest of filamentous algae, which in turn provides accommondation and in many cases food for many invertebrates, including gastropods, amphipods and larval Diptera. Spirorbid worms on the underbuttons are confined to sites sheltered from strong water currents and wave action, but other epiphytes of the underbuttons show little regard for these features. Microfores and its associated fauna are restricted to sheltered sites. Perspex discs set up as imitation Himanthalia buttons were colonized by the same epiphytes as real Himanthalia buttons, but on both sides, indicating the existence of a special protective mechanism for the upper surfaces of real Himanthalia buttons.

  1. Remote field Eddy Current Technique Development for Gap Measurement of Neighboring Tubes of Nuclear Fuel Channel in Pressurized Heavy Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H. K.; Lee, D. H.; Lee, Y. S.; Huh, H.; Cheong, Y. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2004-04-15

    Liquid Injection Nozzle(LIN) tube and Calandria tube(CT) in pressurized Heavy Water Reactor (PHWR) are cross-aligned horizontally. These neighboring tubes can contact each other due to the sag of the calandria tube resulting from the irradiation creep and thermal creep, and fuel load, etc. In order to judge the contact which might be the safety concern, the remote field eddy current (RFEC) technology is applied for the gap measurement in this paper. LIN can be detected by inserting the RFEC probe into pressure tube (PT) at the crossing point directly. To obtain the optimal conditions of the RFEC inspection, the sensitivity, penetration and noise signals are considered simultaneously. The optimal frequency and coil spacing are 1kHz and 200mm respectively. Possible noises during LIN signal acquisition are caused by lift-off, PT thickness variation, and gap variation between PT and CT. The simulated noise signals were investigated by the Volume Integral Method(VIM). Signal analysis on the voltage plane describes the amplitude and shape of LIN and possible defects at several frequencies. All the RFEC measurements in the laboratory were done in variance with the CT/LIN gap and showed the relationship between the LIN gap and the signal parameters by analyzing the voltage plane signals

  2. Building new WDM regulations for the Namibian tourism sector on factors influencing current water-management practices at the enterprise level

    Science.gov (United States)

    Schachtschneider, Klaudia

    Namibia’s aridity is forcing its water sector to resort to new water resource management approaches, including water demand management (WDM). Such a change in management approach is facilitated through the country’s opportunity at independence to rewrite and adapt its old policies, including those for water and tourism. Legal support for WDM through the Water Act and other sector-specific Acts is crucial to plan the practical implementation of WDM throughout the different water use sectors of Namibia. In order to be able to put the policy into practice, it is imperative to understand which factors motivate people to adopt WDM initiatives. Within the Namibian tourism industry three main factors have been identified which influence the water-management approaches at tourist facilities. This paper discusses how the water and tourism decision makers can consider these factors when developing new regulations to introduce WDM in the tourism sector.

  3. Study of counter current flow limitation model of MARS-KS and SPACE codes under Dukler's air/water flooding test conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Woong; Kim, Min Gil; Lee, Jeong Ik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Bang, Young Seok [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    In particular, CCFL(the counter current flow limitation) occurs in components such as hot leg, downcomer annulus and steam generator inlet plenum during LOCA which is possible to have flows in two opposite directions. Therefore, CCFL is one of the thermal-hydraulic models which has significant effect on the reactor safety analysis code performance. In this study, the CCFL model will be evaluated with MARS-KS based on two-phase two-field governing equations and SPACE code based on two-phase three-field governing equations. This study will be conducted by comparing MARS-KS code which is being used for evaluating the safety of a Korean Nuclear Power Plant and SPACE code which is currently under assessment for evaluating the safety of the designed nuclear power plant. In this study, comparison of the results of liquid upflow and liquid downflow rate for different gas flow rate from two code to the famous Dukler's CCFL experimental data are presented. This study will be helpful to understand the difference between system analysis codes with different governing equations, models and correlations, and further improving the accuracy of system analysis codes. In the nuclear reactor system, CCFL is an important phenomenon for evaluating the safety of nuclear reactors. This is because CCFL phenomenon can limit injection of ECCS water when CCFL occurs in components such as hot leg, downcomer annulus or steam generator inlet plenum during LOCA which is possible to flow in two opposite directions. Therefore, CCFL is one of the thermal-hydraulic models which has significant effect on the reactor safety analysis code performance. In this study, the CCFL model was evaluated with MARS-KS and SPACE codes for studying the difference between system analysis codes with different governing equations, models and correlations. This study was conducted by comparing MARS-KS and SPACE code results of liquid upflow and liquid downflow rate for different gas flow rate to the famous Dukler

  4. Experimental investigation of droplet separation in a horizontal counter-current air/water stratified flow; Experimentelle Untersuchung der Tropfenabscheidung einer horizontalen, entgegengerichteten Wasser/Luft-Schichtenstroemung

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Stephan Gerhard

    2015-07-01

    A stratified counter-current two-phase gas/liquid flow can occur in various technical systems. In the past investigations have mainly been motivated by the possible occurrence of these flows in accident scenarios of nuclear light water-reactors and in numerous applications in process engineering. However, the precise forecast of flow parameters, is still challenging, for instance due to their strong dependency on the geometric boundary conditions. A new approach which uses CFD methods (Computational Fluid Dynamics) promises a better understanding of the flow phenomena and simultaneously a higher scalability of the findings. RANS methods (Reynolds Averaged Navier Stokes) are preferred in order to compute industrial processes and geometries. A very deep understanding of the flow behavior and equation systems based on real physics are necessary preconditions to develop the equation system for a reliable RANS approach with predictive power. Therefore, local highly resolved, experimental data is needed in order to provide and validate the required turbulence and phase interaction models. The central objective of this work is to provide the data needed for the code development for these unsteady, turbulent and three-dimensional flows. Experiments were carried out at the WENKA facility (Water Entrainment Channel Karlsruhe) at the Karlsruhe Institute of Technology (KIT). The work consists of a detailed description of the test-facility including a new bended channel, the measurement techniques and the experimental results. The characterization of the new channel was done by flow maps. A high-speed imaging study gives an impression of the occurring flow regimes, and different flow phenomena like droplet separation. The velocity distributions as well as various turbulence values were investigated by particle image velocimetry (PIV). In the liquid phase fluorescent tracer-particles were used to suppress optical reflections from the phase surface (fluorescent PIV, FPIV

  5. Current status of the global change observation mission - water SHIZUKU (GCOM-W) and the advanced microwave scanning radiometer 2 (AMSR2) (Conference Presentation)

    Science.gov (United States)

    Maeda, Takashi; Kachi, Misako; Kasahara, Marehito

    2016-10-01

    Japan Aerospace Exploration Agency (JAXA) launched the Global Change Observation Mission - Water (GCOM-W) or "SHIZUKU" in 18 May 2012 (JST) from JAXA's Tanegashima Space Center. The GCOM-W satellite joins to NASA's A-train orbit since June 2012, and its observation is ongoing. The GCOM-W satellite carries the Advanced Microwave Scanning Radiometer 2 (AMSR2). The AMSR2 is a multi-frequency, total-power microwave radiometer system with dual polarization channels for all frequency bands, and successor microwave radiometer to the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) loaded on the NASA's Aqua satellite. The AMSR-E kept observation in the slower rotation speed (2 rotations per minute) for cross-calibration with AMSR2 since December 2012, its operation ended in December 2015. The AMSR2 is designed almost similarly as the AMSR-E. The AMSR2 has a conical scanning system with large-size offset parabolic antenna, a feed horn cluster to realize multi-frequency observation, and an external calibration system with two temperature standards. However, some important improvements are made. For example, the main reflector size of the AMSR2 is expanded to 2.0 m to observe the Earth's surface in higher spatial resolution, and 7.3-GHz channel is newly added to detect radio frequency interferences at 6.9 GHz. In this paper, we present a recent topic for the AMSR2 (i.e., RFI detection performances) and the current operation status of the AMSR2.

  6. Comparing the effectiveness of chronic water column tests with the crustaceans Hyalella azteca (order: Amphipoda) and Ceriodaphnia dubia (order: Cladocera) in detecting toxicity of current-use insecticides.

    Science.gov (United States)

    Deanovic, Linda A; Markiewicz, Dan; Stillway, Marie; Fong, Stephanie; Werner, Inge

    2013-03-01

    Standard U.S. Environmental Protection Agency laboratory tests are used to monitor water column toxicity in U.S. surface waters. The water flea Ceriodaphnia dubia is among the most sensitive test species for detecting insecticide toxicity in freshwater environments.Its usefulness is limited, however, when water conductivity exceeds 2,000 µS/cm (approximately 1 ppt salinity) and test effectiveness is insufficient. Water column toxicity tests using the euryhaline amphipod Hyalella azteca could complement C. dubia tests; however, standard chronic protocols do not exist. The present study compares the effectiveness of two water column toxicity tests in detecting the toxicity of two organophosphate (OP) and two pyrethroid insecticides: the short-term chronic C. dubia test, which measures mortality and fecundity, and a 10-d H. azteca test, which measures mortality and growth. Sensitivity was evaluated by comparing effect data, and end point variability was evaluated by comparing minimum significant differences. Tests were performed in synthetic water and filtered ambient water to quantify the influence of water matrix on effect concentrations. The H. azteca test detected pyrethroid toxicity far more effectively, while the C. dubia test was more sensitive to OPs. Among endpoints, H. azteca mortality was most robust. The results demonstrate that the H. azteca test is preferable when conductivity of water samples is 2,000 to 10,000 µS/cm or if contaminants of concern include pyrethroid insecticides.

  7. Current Situation and Countermeasures of Dingzhou Water Resources Development and Utilization%定州市水资源开发利用现状及对策

    Institute of Scientific and Technical Information of China (English)

    李卫涛

    2009-01-01

    定州市位于河北中部平原地区,根据水资源现状的供需分析,该市资源型水危机已日渐显现.地下水污染也不可忽视,而且水质有进一步恶化的趋势,无论水量或水质远不能适应今后经济发展的需要,因此必须尽早采取措施,缓解水资源紧缺,有效地保护水质,是定州市当务之急.针对定州市水资源现状,提出了"开源、节流、减污、强化管理"等一系列综合措施.%Dingzhou City is located at the central plain area of Hebei Province. According to the status of water supply and demand analysis, the water crisis of lacking in resource is growing. Groundwater contamination should not be ignored, and the water quality trends towards further deterioration. Whether water requirement or water quality , the Dingzhou water resources cannot meet the needs of the economic development in future. So, it is necessary to adopt measures to alleviate the shortage of water resources and effective protection of water quality. The paper proposes several suggestions for resolving the shortage of water resources. In combination with the status of water resources in Dingzhou City, a serial synthetic measures are proposed, including water-resources spreading, water saving, pollution decreasing and strengthening management etc.

  8. Syntheses of the current model applications for managing water and needs for experimental data and model improvements to enhance these applications

    Science.gov (United States)

    This volume of the Advances in Agricultural Systems Modeling series presents 14 different case studies of model applications to help make the best use of limited water in agriculture. These examples show that models have tremendous potential and value in enhancing site-specific water management for ...

  9. Water citizenship

    DEFF Research Database (Denmark)

    Paerregaard, Karsten; Stensrud, Astrid Bredholt; Andersen, Astrid Oberborbeck

    2016-01-01

    This article examines the implementation of Peru’s new water law and discusses how it produces new forms of water citizenship. Inspired by the global paradigm of “integrated water resources management,” the law aims to include all citizens in the management of the country’s water resources...... by embracing a “new water culture.” We ask what forms of water citizenship emerge from the new water law and how they engage with local water practices and affect existing relations of inequality. We answer these questions ethnographically by comparing previous water legislation and how the new law currently...... is negotiated and contested in three localities in Peru’s southern highlands. We argue that the law creates a new water culture that views water as a substance that is measurable, quantifiable, and taxable, but that it neglects other ways of valuing water. We conclude that water citizenship emerges from...

  10. Mean annual water-budget components for the Island of Kauai, Hawaii, for current conditions, 2001-10 rainfall and 2001-10 land cover

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The shapefile associated with this metadata file represents the spatial distribution of mean annual water-budget components, in inches, for the Island of Kauai,...

  11. Mean annual water-budget components for the Island of Oahu, Hawaii, for current conditions, 2001-10 rainfall and 2001-10 land cover

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The shapefile associated with this metadata file represents the spatial distribution of mean annual water-budget components, in inches, for the Island of Oahu,...

  12. Mean annual water-budget components for the Island of Maui, Hawaii, for current conditions, 2001-10 rainfall and 2001-10 land cover

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The shapefile associated with this metadata file represents the spatial distribution of mean annual water-budget components, in inches, for the Island of Maui,...

  13. Spatial and temporal variability of the heat budget parameters and currents in the coastal waters of Visakhapatnam, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.; Rao, B.P.; Rao, D.P.; Rao, V.S.

    Analysis of the thermal structure in coastal waters off Visakhapatnam revealed sub-surface inversions during October. In postmonsoon, a good association existed between wind stress (tau) and total heat loss (Qe+Qs) and between SST and heat content...

  14. Is current irrigation sustainable in the United States? An integrated assessment of climate change impact on water resources and irrigated crop yields.

    Science.gov (United States)

    Blanc, Elodie; Caron, Justin; Fant, Charles; Monier, Erwan

    2017-08-01

    While climate change impacts on crop yields has been extensively studied, estimating the impact of water shortages on irrigated crop yields is challenging because the water resources management system is complex. To investigate this issue, we integrate a crop yield reduction module and a water resources model into the MIT Integrated Global System Modeling framework, an integrated assessment model linking a global economic model to an Earth system model. We assess the effects of climate and socioeconomic changes on water availability for irrigation in the U.S. as well as subsequent impacts on crop yields by 2050, while accounting for climate change projection uncertainty. We find that climate and socioeconomic changes will increase water shortages and strongly reduce irrigated yields for specific crops (i.e., cotton and forage), or in specific regions (i.e., the Southwest) where irrigation is not sustainable. Crop modeling studies that do not represent changes in irrigation availability can thus be misleading. Yet, since the most water-stressed basins represent a relatively small share of U.S. irrigated areas, the overall reduction in U.S. crop yields is small. The response of crop yields to climate change and water stress also suggests that some level of adaptation will be feasible, like relocating croplands to regions with sustainable irrigation or switching to less irrigation intensive crops. Finally, additional simulations show that greenhouse gas (GHG) mitigation can alleviate the effect of water stress on irrigated crop yields, enough to offset the reduced CO2 fertilization effect compared to an unconstrained GHG emission scenario.

  15. Quantifying water flow within aquatic ecosystems using load cell sensors: a profile of currents experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Johansen, Jacob L

    2014-01-01

    Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (reef system around Lizard Island (Great Barrier Reef, Australia) at a spatial and temporal scale relevant to the ecology of individual benthos and fish. The instrument uses load-cell sensors to provide a correlation between sensor output and ambient current velocity of 99%. Each instrument is able to continuously record current velocities to >500 cms⁻¹ and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.). Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm⁻² allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m), mid-slope (6 m) and deep-slope (9 m depth) of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms⁻¹, while tidal currents rarely exceed 5.5 cms⁻¹. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m) and frequency (0.54 to 0.20 Hz), emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats.

  16. Spin current

    CERN Document Server

    Valenzuela, Sergio O; Saitoh, Eiji; Kimura, Takashi

    2012-01-01

    In a new branch of physics and technology called spin-electronics or spintronics, the flow of electrical charge (usual current) as well as the flow of electron spin, the so-called 'spin current', are manipulated and controlled together. This book provides an introduction and guide to the new physics and application of spin current.

  17. Analysis of water flow, power and electrical current of a motor pump powered by photovoltaic panels; Analise da vazao, potencia e corrente em uma motobomba acionada por paines fotovoltaicos

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Paulo Takashi; Santos, Jose Airton Azevedo dos; Michels, Roger Nabeyama [Universidade Tecnologica Federal do Parana (UTFPR-MD), Medianeira, PR (Brazil)], E-mail: airton@utfpr.edu.br; Ricieri, Reinaldo Prandini [Universidade do Oeste Paulista (UNIOESTE), Cascavel, PR (Brazil). Dept. de Engenharia Agricola], E-mail: ricieri@unioeste.br; Halmeman, Maria Cristina Rodrigues [Universidade Tecnologica Federal do Parana (UTFPR-CM), Campo Mourao, PR (Brazil)

    2009-07-01

    Because of the high cost of electricity connection to distant places, far away from conventional nets, photovoltaic solar energy is widely used in public illumination, water pumping, medical care centers, etc. With the purpose to contribute to a better utilization in this type of energy, the object of the project is to analyze the water flow, power and electrical current of a motor pump to be used for water lift, driven by photovoltaic panels, the data will be collected at every 2 meters in height from 2.2 to 18.2 meters. The analyses show the outflow linear dependence in relation to the height of the water lift, a second order dependence of the electrical power provided by the photovoltaic panels in relation to the solar irradiance on the panels and a linear dependence of the electrical current in relation to the solar irradiance. This study is a part of a project developed at the 'Universidade Tecnologica Federal do Parana' (UTFPR) - Campus Medianeira - PR. Two photovoltaic panels were used from Solarex Brand, model MSX 56, a motor pump made by Shurflo Ltd, model 2088-732, two pyranometers from KIPP and ZONEN CM3, a type K thermocouple, a pressure transducer model HUBA-510 and a water flow transducer. (author)

  18. The Chukchi slope current

    Science.gov (United States)

    Corlett, W. Bryce; Pickart, Robert S.

    2017-04-01

    Using a collection of 46 shipboard hydrographic/velocity transects occupied across the shelfbreak and slope of the Chukchi Sea between 2002 and 2014, we have quantified the existence of a current transporting Pacific-origin water westward over the upper continental slope. It has been named the Chukchi slope current, which is believed to emanate from Barrow Canyon. The current is surface-intensified, order 50 km wide, and advects both summer and winter waters. It is not trapped to a particular isobath, but instead is reminiscent of a free jet. There is no significant variation in Pacific water transport with distance from Barrow Canyon. A potential vorticity analysis suggests that the flow is baroclinically unstable, consistent with the notion that it meanders. The current is present during all synoptic wind conditions, but increases in strength from summer to fall presumably due to the seasonal enhancement of the easterly winds in the region. Its transport increased over the 12-year period of data coverage, also likely in response to wind forcing. In the mean, the slope current transports 0.50 ± 0.07 Sv of Pacific water. This estimate allows us to construct a balanced mass budget of the Chukchi shelf inflows and outflows. Our study also confirms the existence of an eastward-flowing Chukchi shelfbreak jet transporting 0.10 ± 0.03 Sv of Pacific water towards Barrow Canyon.

  19. Features and spatial distribution of circumpolar deep water in the southern Indian Ocean and the effects of Antarctic circum polar current

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The data from the Southern Ocean observations of World Ocean Circulation Experiment(WOCE)are used for analysis and illustration of the features and spatial distributions of Circumpolar Deep Water(CDW)in the southern Indian Ocean.It is learnt from the comparison among the vertical distributions of temperature/salinity/oxygen along the (30.)E, (90.)E and (145.)E sections respectively that some different features of CDW and the fronts can be found at those longitudes, and those differences can be attributed to the zonal transoceanic flow and the merizonal movement in the Circumpolar Deep Water.In fact, the zonal transoceanic flow is the main dynamic factor for the water exchange between the Pacific Ocean and the Indian Ocean or between the Atlantic Ocean and the Indian Ocean, and for the effects on the spatial distributions of the physical properties in CDW.

  20. Quantifying water flow within aquatic ecosystems using load cell sensors: a profile of currents experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.

    Directory of Open Access Journals (Sweden)

    Jacob L Johansen

    Full Text Available Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (500 cms⁻¹ and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.. Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm⁻² allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m, mid-slope (6 m and deep-slope (9 m depth of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms⁻¹, while tidal currents rarely exceed 5.5 cms⁻¹. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m and frequency (0.54 to 0.20 Hz, emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats.

  1. MIXED FINITE ELEMENT METHODS FOR THE SHALLOW WATER EQUATIONS INCLUDING CURRENT AND SILT SEDIMENTATION (Ⅰ)-THE CONTINUOUS-TIME CASE

    Institute of Scientific and Technical Information of China (English)

    罗振东; 朱江; 曾庆存; 谢正辉

    2004-01-01

    An initial-boundary value problem for shallow equation system consisting of water dynamics equations, silt transport equation, the equation of bottom topography change, and of some boundary and initial conditions is studied, the existence of its generalized solution and semidiscrete mixed finite element (MFE) solution was discussed, and the error estimates of the semidiscrete MFE solution was derived. The error estimates are optimal.

  2. 北京河流水污染现状分析研究%Current Status of Rivers Water Quality in Beijing

    Institute of Scientific and Technical Information of China (English)

    景焕平; 王崇臣; 王鹏

    2015-01-01

    通过总结近年来北京河流中氮磷、有机质和重金属等方面的研究成果,结果表明北运河水系各河段水质均较差,劣Ⅴ类水质的河流长度超过80%,城市河流污染特征明显,主要污染指标为耗氧型有机污染物和氨氮,重金属污染较轻,悬浮物中的重金属占较大的比重;永定河水系枯水期氮污染较重,主要是硝态氮超标,以颗粒态磷为主要形式的磷污染较轻,重金属含量大都低于地表水Ⅲ类标准;潮白河水系水质较好,各水质指标除个别断面外大都满足中Ⅲ类水标准,重金属含量大都符合Ⅰ~Ⅲ类水标准。%Some references on the rivers water quality in Beijing were reviewed with consideration for nitrogen , phosphorus, organic matter and heavy metal pollution.The results revealed that the water quality of Beiyun River water system is very poor as more than 80% of the rivers is below class V , and the main pollutants are organics of oxygen consumption and ammonia nitrogen , as well as less serious contamination of heavy metal which chiefly comes from suspended solids .Water pollution in Yongding River is very serious in dry season, mainly characterized by nitrogen pollution, especially for nitrate.Phosphorus pollution which mainly caused by particulate phosphorus is less serious.Most heavy metal contents are in class Ⅲ.The water quality of Chaobai River is much better, as most of the water quality indexes meet class Ⅲ and heavy metals mostly meetⅠ~Ⅲ water standard except for some individual sections.

  3. Fishes of water bodies within the Ukrainian part of the Chernobyl exclusion zone: current levels of radioactive contamination and absorbed dose rate

    Energy Technology Data Exchange (ETDEWEB)

    Kaglyan, Alexander Ye.; Gudkov, Dmitri I. [Institute of Hydrobiology of the NAS of Ukraine, Geroyiv Stalingrada Ave. 12, UA- 04210, Kyiv (Ukraine)

    2014-07-01

    The results of studies of radioactive contamination of ichthyofauna of water bodies of the Chernobyl exclusion zone (ChEZ) during 2012-2013 are presented. The fish sampled from water bodies with different hydrological mode was used: (1) stagnant lakes (Vershyna, Glyboke, Azbuchyn, Daleke); (2) reservoir with slow water exchange (cooling pond of the Chernobyl NPP); (3) conditionally stagnant water bodies (separated from the main riverbed of the Pripyat River - Yanovsky and Novoshepelichesky Crawls and part of the Krasnensky former river bed); (4) semi-flowing water body (Krasnensky former river bed located outside of the dammed territory); (5) open crawls of the Pripyat river ('Schepochka' and Chernobylsky) and (6) waterway (riverbed sites of the Pripyat River). The highest levels of radionuclide concentrations were determined in fish of the stagnant water objects - 937-25907 Bq/kg (w.w.) of {sup 137}Cs and 1845-101220 Bq/kg of {sup 90}Sr. In fish of cooling pond the concentration of {sup 137}Cs registered in range 750-4200 and {sup 90}Sr - 41-512 Bq/kg. In ichthyofauna of water bodies which concern to the third group, specific activity of {sup 137}Cs and {sup 90}Sr fluctuated accordingly within range of 520-3385 and 722-6210, and in a semi-flowing reservoir - 573-2948 and 97-4484 Bq/kg. The concentrations of {sup 137}Cs in fish of the fifth and sixth groups were accordingly 25-159 and 11-224 as well as {sup 90}Sr - 36-174 and 3-14 Bq/kg. The ratio of specific activity of {sup 90}Sr/{sup 137}Cs for pray fish from all studied groups of water bodies, except the second and the sixth ones, was in range 1.5-39.7. Thus intensity of water exchange is one of the defining factors, influencing on level of radionuclide specific activity in fish, especially {sup 90}Sr - the higher the flow age, the lower the level of radioactive contamination of fish inhabiting it. Calculation of the absorbed dose rate has shown that highest radiation dose was in fish inhabiting lake

  4. Physiologically based pharmacokinetic modeling of human exposure to perfluorooctanoic acid suggests historical non drinking-water exposures are important for predicting current serum concentrations.

    Science.gov (United States)

    Worley, Rachel Rogers; Yang, Xiaoxia; Fisher, Jeffrey

    2017-09-01

    Manufacturing of perfluorooctanoic acid (PFOA), a synthetic chemical with a long half-life in humans, peaked between 1970 and 2002, and has since diminished. In the United States, PFOA is detected in the blood of >99% of people tested, but serum concentrations have decreased since 1999. Much is known about exposure to PFOA in drinking water; however, the impact of non-drinking water PFOA exposure on serum PFOA concentrations is not well characterized. The objective of this research is to apply physiologically based pharmacokinetic (PBPK) modeling and Monte Carlo analysis to evaluate the impact of historic non-drinking water PFOA exposure on serum PFOA concentrations. In vitro to in vivo extrapolation was utilized to inform descriptions of PFOA transport in the kidney. Monte Carlo simulations were incorporated to evaluate factors that account for the large inter-individual variability of serum PFOA concentrations measured in individuals from North Alabama in 2010 and 2016, and the Mid-Ohio River Valley between 2005 and 2008. Predicted serum PFOA concentrations were within two-fold of experimental data. With incorporation of Monte Carlo simulations, the model successfully tracked the large variability of serum PFOA concentrations measured in populations from the Mid-Ohio River Valley. Simulation of exposure in a population of 45 adults from North Alabama successfully predicted 98% of individual serum PFOA concentrations measured in 2010 and 2016, respectively, when non-drinking water ingestion of PFOA exposure was included. Variation in serum PFOA concentrations may be due to inter-individual variability in the disposition of PFOA and potentially elevated historical non-drinking water exposures. Published by Elsevier Inc.

  5. The Current Situation Countermeasures of Chinese Water Fitness Sports%我国水中健身运动的现状及发展对策研究

    Institute of Scientific and Technical Information of China (English)

    于荣; 王东

    2011-01-01

    In this paper, the method of literature, questionnaire and interviews with experts, water, the present situation and development of fitness strategies of research and analysis. The conclusion:the water with srmfll, not easily fitness impact injuries, muscle development, interesting equilibrium strong characteristic;after more than ten years of development the water fitness gradually by people to understand and meet and become a kind of fashion fitness methods;the water temperature,by such factors as the limit,the water in our country in fitness are not widely available,need to be further cultivate market, and explore the right market operation mode.%运用文献资料法、问卷调查法、专家访谈法,对水中健身的现状及发展对策进行研究和分析,得出结论:水中健身具有冲击力小、不易受伤、发展肌肉均衡、趣味性强的特点;经过十几年的发展水中健身正逐渐被人们了解和认识,成为一种时尚的健身方式;受场地、水温等因素的限制,水中健身在我国开展还不够普及,需要进一步培育市场,探索合适的市场运作模式。

  6. The Current Situation and Exploration of Market Prospect of Water Soluble Fertilizers in China%我国水溶性肥料的现状与市场前景探讨

    Institute of Scientific and Technical Information of China (English)

    熊思健; 陈绍荣; 刘园园

    2013-01-01

    The development history of water soluble fertilizers in China is outlined .By analyzing the current situation of production of water soluble fertilizers , suggests are made that their development trend should be high efficiency and multi-effect with the emphases of promoting development of chelate technology and additive technology and expanding functions of water soluble fertilizers .%概述了我国水溶性肥料的发展历史。在分析我国水溶肥生产现状的基础上,提出了高效化、多效化的发展方向,并加强螯合技术、助剂技术以及扩大水溶性肥料功能范围方面的研究。

  7. Current power plant

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, J.H.

    1979-03-06

    A current power plant is described that includes a shaft mounted turbine wheel for employment in water current, a housing adjacent the impeller and to which the shaft extends, a ramp positioned on the upstream side of the impellar, and a frame on which the turbine wheel is mounted. The frame is mounted by rollers on a tract such that the impeller and frame may be rolled on the tracks inside the housing, whereafter doors are closed, and water around the turbine wheel may be pumped out to facilitate turbine repair.

  8. Preliminary Structural Design Conceptualization for Composite Rotor for Verdant Power Water Current: Cooperative Research and Development Final Report, CRADA Number CRD-08-296

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, S.

    2011-02-01

    The primary thrust of the CRADA will be to develop a new rotor design that will allow higher current flows (>4m/s), greater swept area (6-11m), and in the process, will maximize performance and energy capture.

  9. 海南省农村生活饮用水卫生现状调查%Current sanitary situation of rural drinking water in Hainan province

    Institute of Scientific and Technical Information of China (English)

    杨斌; 王帅; 符致效; 陈彩云

    2011-01-01

    目的 了解海南省农村生活饮用水的卫生现状.方法 在海南省18个市县随机抽取10个监测县,在每个监测县选择10户居民家庭作为监测点,采用统一的调查表对监测点的水源类型、供水方式、覆盖人口等进行调查;于2009年丰(7-9月)、枯水期(1-3月)进行水样的采集、检验和评价.结果 海南省农村生活饮用水水源主要以地下水为主,供水方式以集中式供水为主;共采集水样246件,合格44件,合格率仅为17.9%,各指标合格率由低至高依次为总大肠菌群(35.4%)<菌落总数(80.1%)water quality and safety in rural areas of Hainan province. Methods Ten counties of total 18 countries in the rural areas of Hainan province were selected. And then 10 villages were selected as the monitoring site in each county. The sampling time was arranged in the rainy(July to September) and dry season(January to March) in 2009. Results The coverage rate of rural centralized water supply was 74. 0% (182/246). The qualification rate of water quality in 2009 was 17. 9% (44/246). The qualification rate of surface water was 22. 6% (12/53) ,higher than that of underground water( 16. 6% ,32/193). The rank of qualification rate of all the monitoring indexes of the water quality was total coliform group(35.4% ), total number of bacterial ( 80. 1% ), pH (82. 9% ), Fe (94. 3% ), Mn (94. 7% ), turbidity (90. 7% ), colority ( 95

  10. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  11. Water, mineral waters and health.

    Science.gov (United States)

    Petraccia, Luisa; Liberati, Giovanna; Masciullo, Stefano Giuseppe; Grassi, Marcello; Fraioli, Antonio

    2006-06-01

    The authors focus on water resources and the use of mineral waters in human nutrition, especially in the different stages of life, in physical activity and in the presence of some morbid conditions. Mineral water is characterized by its purity at source, its content in minerals, trace elements and other constituents, its conservation and its healing properties recognized by the Ministry of Health after clinical and pharmacological trials. Based on total salt content in grams after evaporation of 1l mineral water dried at 180 degrees C (dry residues), mineral waters can be classified as: waters with a very low mineral content, waters low in mineral content, waters with a medium mineral content, and strongly mineralized waters. Based on ion composition mineral waters can be classified as: bicarbonate waters, sulfate waters, sodium chloride or saltwater, sulfuric waters. Based on biological activity mineral waters can be classified as: diuretic waters, cathartic waters, waters with antiphlogistic properties. Instructions for use, doses, and current regulations are included.

  12. The Bransfield Gravity Current

    Science.gov (United States)

    Sangrà, Pablo; Stegner, Alexander; Hernández-Arencibia, Mónica; Marrero-Díaz, Ángeles; Salinas, Carolina; Aguiar-González, Borja; Henríquez-Pastene, Cristian; Mouriño-Carballido, Beatriz

    2017-01-01

    Using in situ data and laboratory experiments, we show that the circulation of the Bransfield Current (BC) around the South Shetland Islands (SSI) may be characterized in terms of a propagating buoyant gravity current. First, we describe the SSI hydrography and some drifter trajectories, paying special attention to the recirculation of the BC at the northeastern tip and northern slopes of the SSI. We observed that when the northeastward-flowing BC reaches the northeastern tip of the SSI, it recirculates around an anticyclonic mesoscale eddy that has not previously been reported in this region. Part of this recirculating water then proceeds southwest along the northern SSI shelf break as a narrow baroclinic jet and another part join the Antarctic Circumpolar Current. Consequently, the cross-slope gradients of properties strengthen, and the southern boundary of the Antarctic Circumpolar Current becomes a nearly submesoscale ( 10 km) front. Second, we compare the observations with buoyant gravity current laboratory experiments in an open basin setup where the SSI topographic barrier is represented by a central wall. The resulting circulation of the buoyant gravity current around the wall mirrors our in situ observations. First, a narrow buoyant gravity current flows northeastward along the southern boundary of the wall. Once the head of the buoyant gravity current reaches the tip of the wall, a recirculating anticyclonic vortex is generated, and the buoyant gravity current then proceeds westward along the north side of the wall. This circulation of the BC around the SSI as a buoyant gravity current may contribute to the fertilization of the waters around the SSI, as suggested by previously reported distributions of nutrients and phytoplankton.

  13. A new process for desalination and electrodeionization of water by means of electrostatic shielding zones – ionic current sinks. Study of optical sensors of the form Al/a-SiC:H/c-Si(n with high sensitivity.

    Directory of Open Access Journals (Sweden)

    A. Dermentzi

    2009-01-01

    Full Text Available We constructed electrostatic shielding zones made of electrode graphite powder and used them as a new type of ionic and electronic current sinks. Because of the local elimination of the applied electric field, voltage and current within the current sinks, ions are led inside them and accumulate there. The sinks become ion concentrating compartments whereas the adjacent compartments become ion depleting compartments. The proposed electrodeionization process uses no permselective ion exchange membranes. We implemented it in electrodialysis desalination of a synthetic brackish 0.03 M NaCl solution and obtained potable water with a NaCl concentration <500 mg L-1. Furthermore, we performed electrodialysis of 0.002 M NiSO4 and electrodeionization of 0.001 M NiSO4 solutions with simultaneous electrochemical regeneration of the used ion exchange resin beds. By the continuous mode of electrodeionization of the 0.001 M NiSO4 solution we obtained pure water with a Ni2+ ion concentration of less than 0.5 mg L-1 at a flow rate of 2.3 x10-4 L s-1 diluate stream

  14. Current challenges in running and maintaining water management systems in catchment areas; Retos actuales de la explotacion y mantenimiento de los sistemas de gestion hidrica en cuencas hidrograficas

    Energy Technology Data Exchange (ETDEWEB)

    Arbaizar Gonzalez, J.

    2003-07-01

    The increasing demands being made on the management of rivers and their associated infrastructures mean that we need to have in place remote control systems supplying hydrological information such as flow rates, water quality, etc. In addition, it is necessary to establish a management culture for maintaining these systems to ensure that the data gathering process is reliable, since such data constitute the basis of all subsequent actions. It is also necessary to have monitoring and analysis systems feeding the system which must be subject to assessment procedures that are sufficiently flexible to enable comparisons to be made over time and space. This allows conclusions to be drawn in real time and to carry out statistical studies of rainfall, freshets, contamination, economic parameters, etc. (Author)

  15. Insulation Diagnosis of Water-treed Cables Based on Polarization and Depolarization Current Method%基于PDC法的水树老化电缆绝缘诊断

    Institute of Scientific and Technical Information of China (English)

    蔡钢; 刘曦; 濮峻嵩; 周凯; 黄明

    2016-01-01

    In order to diagnose the insulation condition of 10 kV power cables simply and rapidly, the diagnosis criterion based on polarization-depolarization current (PDC) characteristics for water-treed cables was investigated. The cable samples were performed accelerated water tree ageing experiment through water needle electrode method, and the morphology of water trees in the samples was observed by micro-scope, and then the length of water trees were counted. At the same time, the water-treed samples were tested by the PDC detection system. The DC conductivity and the non-linearity factor of cable insulation were acquired by the measured polarization and depolarization current curves, and the change tendency of the two parameters with the ageing condition of cables was analyzed. The results show that the water tree ageing problems in cable insulation can be assessed effectively via the change of DC conductivity and non-linearity factor.%为对10 kV运行电缆的绝缘状态进行简单、快速诊断,基于极化-去极化电流(PDC)特征研究了针对电缆水树老化的绝缘诊断判据。采用高频高压水针电极法对电缆实验样品进行加速水树老化,使用显微镜定期观察不同老化时期样品中的水树形态,并统计水树长度,同时使用PDC测试平台对水树老化样品进行测试。利用测得的极化和去极化电流曲线求得电缆绝缘层的直流电导率和非线性系数,分析两参数随样品老化程度的变化趋势及规律。结果表明:根据直流电导率和非线性系数的变化能有效判别电缆绝缘中的水树老化问题。

  16. Current Titles

    Energy Technology Data Exchange (ETDEWEB)

    Various

    2006-06-01

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Jane Cavlina, Administrator, at 510/486-6036.

  17. Longshore water-current velocity and the potential for transport of contaminants—A pilot study in Lake Erie from Walnut Creek to Presque Isle State Park beaches, Erie, Pennsylvania, June and August 2015

    Science.gov (United States)

    Hittle, Elizabeth A.

    2017-04-20

    Bacteria-driven restrictions and (or) advisories on swimming at beaches in Presque Isle State Park (PISP), Erie, Pennsylvania, can occur during the summer months. One of the suspected sources of bacteria is sediment. A terrestrial sediment source to the west of PISP is Walnut Creek, which discharges to Lake Erie about 8.5 kilometers southwest of PISP Beach 1. On June 24, June 25, August 18, and August 19, 2015, synoptic surveys were conducted by the U.S. Geological Survey, in cooperation with the Pennsylvania Sea Grant, in Lake Erie between Walnut Creek and PISP Beach 1 to characterize the water-current velocity and direction to determine whether sediment from Walnut Creek could be affecting the PISP beaches. Water-quality data (temperature, specific conductance, and turbidity) were collected in conjunction with the synoptic surveys in June. Water-quality data (Escherichia coli [E. coli] bacteria, temperature, and turbidity) were collected about a meter from the shore (nearshore) on June 24, August 19, and after a precipitation event on August 11, 2015. Additionally, suspended sediment was collected nearshore on June 24 and August 11, 2015. Samples collected near Walnut Creek during all three bacterial sampling events contained higher counts than other samples. Counts steadily decreased from west to east, then increased about 1–2 kilometers from PISP Beach 1; however, this study was not focused on examining other potential sources of bacteria.The Velocity Mapping Toolbox (VMT) was used to process the water-current synoptic surveys, and the results were visualized within ArcMap. For the survey accomplished on June 24, 2015, potential paths a particle could take between Walnut Creek and PSIP Beach 1 if conditions remained steady over a number of hours were visualized. However, the water-current velocity and direction were variable from one day to the other, indicating this was likely an unrealistic assumption for the study area. This analysis was not accomplished

  18. Boron in reverse osmosis water desalination: current situational and applying technologies for its removal; El boro en las aguas desaladas por osmosis inversa: situacion actual y tecnologias aplicables para su eliminacion

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigo Sanz, M.; Penate Suarez, B.

    2007-07-01

    In most of the seawater reverse osmosis desalination plants operating in one stage, the water produced presents values bordering or exceeding the limit established by the Spanish legislation for boron content of 1mg/l. As well as on the intrinsic features of the membrane elements, the boron removal in the desalination process depends on various factors. In this article the most relevant ones are described and a synopsis of the applied technologies and designs is introduced in order to fulfil current regulations. (Author)

  19. 广西河湖水域岸线管理现状分析及建议%Current status analysis and suggestions for administration of river-lake shoreline and water area in Guangxi

    Institute of Scientific and Technical Information of China (English)

    王晓妮

    2013-01-01

    An introduction was made on the current status of river-lake shoreline and water area administration in Guangxi. The author analyzed the major problems and put forward suggestions for strengthening administration.%  介绍了广西河湖水域岸线管理现状,分析现阶段管理中存在的主要问题,并提出加强河湖水域及岸线管理的建议措施。

  20. Regional climate modeling of heat stress, frost, and water stress events in the agricultural region of Southwest Western Australia under the current climate and future climate scenarios.

    Science.gov (United States)

    Kala, Jatin; Lyons, Tom J.; Abbs, Deborah J.; Foster, Ian J.

    2010-05-01

    Heat stress, frost, and water stress events have significant impacts on grain quality and production within the agricultural region (wheat-belt) of Southwest Western Australia (SWWA) (Cramb, 2000) and understanding how the frequency and intensity of these events will change in the future is crucial for management purposes. Hence, the Regional Atmospheric Modeling System (Pielke et al, 1992) (RAMS Version 6.0) is used to simulate the past 10 years of the climate of SWWA at a 20 km grid resolution by down-scaling the 6-hourly 1.0 by 1.0 degree National Center for Environmental Prediction Final Analyses from December 1999 to Present. Daily minimum and maximum temperatures, as well as daily rainfall are validated against observations. Simulations of future climate are carried out by down-scaling the Commonwealth Scientific and Industrial Research Organization (CSIRO) Mark 3.5 General Circulation Model (Gordon et al, 2002) for 10 years (2046-2055) under the SRES A2 scenario using the Cubic Conformal Atmospheric Model (CCAM) (McGregor and Dix, 2008). The 6-hourly CCAM output is then downscaled to a 20 km resolution using RAMS. Changes in extreme events are discussed within the context of the continued viability of agriculture in SWWA. Cramb, J. (2000) Climate in relation to agriculture in south-western Australia. In: The Wheat Book (Eds W. K. Anderson and J. R. Garlinge). Bulletin 4443. Department of Agriculture, Western Australia. Gordon, H. B., Rotstayn, L. D., McGregor, J. L., Dix, M. R., Kowalczyk, E. A., O'Farrell, S. P., Waterman, L. J., Hirst, A. C., Wilson, S. G., Collier, M. A., Watterson, I. G., and Elliott, T. I. (2002). The CSIRO Mk3 Climate System Model [Electronic publication]. Aspendale: CSIRO Atmospheric Research. (CSIRO Atmospheric Research technical paper; no. 60). 130 p McGregor, J. L., and Dix, M. R., (2008) An updated description of the conformal-cubic atmospheric model. High Resolution Simulation of the Atmosphere and Ocean, Hamilton, K. and Ohfuchi

  1. The Role of Benthic Currents and Sediment Transport On Deep-water Coral Mound Morphology and Growth: Examples From The Belgica and Moira Mounds, Eastern Porcupine Seabight, NE Atlantic

    Science.gov (United States)

    Wheeler, A.; Kozachenko, M.; Olu-Le Roy, K.

    Deep-water corals and associated carbonate mound build-ups are extensive along the European continental margin coincident with areas of strong benthic current activity and, often, regions of active sand transport. Although as yet unsubstantiated links to hydrocarbon seepage may play a defining role in the generation of carbonate mounds, the growth of mounds is strongly influenced by benthic current activity. Furthermore, the morphology of mounds, both in terms of their overall shape and surface morpho- logical features, is strongly dictated by the benthic-currents. Giant carbonate mounds, e.g. the Thérèse Mound, Belgica Mound province, eastern Porcupine Seabight, NE Atlantic, show upstream growth (through biological and sed- imentary accretion) with downstream scour and sediment starvation influencing their overall morphology. The surface morphological details of these giant mounds show distinct relationships to sediment waves that have become colonised and stabilised by coral and associated communities. Once colonised, the sandwave surface-morphology is mimic by biological growth with corals preferential growing on wave crests, taking advantage of stronger current and nutrient flux, to form coral banks. Furthermore, erosion of carbonate mounds by strong current activity exposes suitable hard substrates for further coral colonisation. Paradoxically therefore, mound erosion stimulates further coral growth illustrating another benthic-current control on mound growth. The Moira Mounds in the Belgica Mound Province, Porcupine Seabight are small coral-colonised mound features (tens of metres across and a few metres high) that represent an early stage of mound development and much younger then their giant carbonate mound counterparts. These features occur in areas of active sand transport, on rippled sand sheets and the upstream margins of sediment wave fields. Once coral colonies gained a SfootingT in these areas, coral colonies trap sand and build posi- & cedil; 1

  2. Current titles

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Gretchen Hermes at (510) 486-5006 or address below for a User`s Guide. Copies of available papers can be ordered from: Theda Crawford National Center for Electron Microscopy, Lawrence Berkeley Laboratory, One Cyclotron Rd., MS72, Berkeley, California, USA 94720.

  3. 波流作用下深水网箱受力及运动变形的数值模拟%Numerical simulation of forces and motion deformation of deep-water net cages in waves and currents

    Institute of Scientific and Technical Information of China (English)

    黄小华; 郭根喜; 胡昱; 陶启友; 张小明

    2011-01-01

    This study is aimed to discuss the effects of waves combined with currents on forces and motion deformation of deep-water net cages, and provides a strong reference to risk assessment for net-cage aquaculture with severe marine conditions. The set value of wave and current elements were as follows: wave heights H=4-6 m,wave periods T=6.0-8.6s, current velocities U=0.3-0.9 m/s. With a numerical model previously validated by physical model tests, the mooring line forces, the wave-current forces, the volume reduction rate and the floating-collar pitches of the deep-water net cage were calculated. The simulated results indicated that the mooring line force, the wave-current force and the volume reduction rate were all in direct proportion to wave height as well as current velocity, but less related to wave period. Furthermore, the wave-current force on the cage was approximately equal to the sum of force on each mooring line on wave-side. The volume reduction rate reached 47%-56% for the cage caused by the conditions of wave height of 4-6 m and current velocity of 0.75m/s, which showed serious cage deformation. Therefore, we concluded that farming sites should not be placed in sea areas where current speed exceeded 0.75 m/s. The calculated results also showed that the influence of wave period on volume reduction rate was slight, while significant on the floating-collar pitch. The floating-collar pitch would decrease as wave period increasing at constant wave height and current velocity.%基于已建立的浮架和网衣数学模型,对不同波况和流速共同作用条件下HDPE深水网箱所受的锚绳力、波流力、容积损失率以及浮架倾角进行数值计算,设计的波流要素值为:波高H=4~6 m,周期T=6.0~8.6 s,流速U=0.3~0.9 m/s.结果表明,网箱锚绳受力、波流力和容积损失率均与波高和流速成正比,与周期的关系不明显,且网箱系统所受的波流力约为网箱迎浪侧两根锚

  4. Low-level bromate analysis in drinking water by ion chromatography with optimized suppressed conductivity cell current followed by a post-column reaction and UV/Vis detection.

    Science.gov (United States)

    Fotsing, Marcellin; Barbeau, Benoit; Prevost, Michele

    2011-01-01

    In the present work, a high capacity anion exchange column was used to efficiently and simultaneously separate traces of oxyhalide disinfection byproducts (DBP) anions and bromide by an ion chromatography system followed by a post-column reaction (PCR). The PCR generates in situ hydroiodic (HI) acid from the excess of potassium iodate that combines with bromate from the column effluent to form the triiodide anion detectable by UV/Vis absorbance at 352 nm. The suppressed conductivity cell current was optimized at 70 mA, with a flow rate of 1.0 mL/min and a 9 mM carbonate eluent. Its performance was investigated on a trace-level determination of bromate in ozonated municipal and bottled drinking water. Based on ozonated municipal drinking water matrix, the method detection limit of 0.27 μg BrO(-)(3)/L was evaluated with the Method Quantification Limit (MQL) of 0.89 μg BrO(-)(3)/L. However, in ultrapure water, a MDL of 0.015 μg BrO(-)(3)/L and a MRL of 0.052 μg BrO(-)(3)/L were achieved. The recovery for spiked municipal samples was in the range of 90%-115%.

  5. Current ornithology

    CERN Document Server

    1983-01-01

    The appearance of the first volume of a projected series is the occasion for comment on scope, aims, and genesis of the work. The scope of Current Ornithology is all of the biology of birds. Ornithology, as a whole-organism science, is concerned with birds at every level of bi­ ological organization, from the molecular to the community, at least from the Jurassic to the present time, and over every scholarly discipline in which bird biology is done; to say this is merely to expand a dic­ tionary definition of "ornithology. " The aim of the work, to be realized over several volumes, is to present reviews or position statements con­ cerning the active fields of ornithological research. The reviews will be relatively short, and often will be done from the viewpoint of a readily­ identified group or school. Such a work could have come into being at any time within the past fifty years, but that Current Ornithology appears now is a result of events that are only seven to eight years old. One important event wa...

  6. Pollution of Municipal Water Supply System by Phthalates and Evaluation on Purification Effects of Current Water Treatment Process%邻苯二甲酸脂对城镇供水的污染及现行水处理工艺净化效果的评价

    Institute of Scientific and Technical Information of China (English)

    韩关根; 吴平谷; 王惠华; 方跃强; 马冰洁; 赵莹

    2001-01-01

    Objective To understand the pollution of municipal water supply system by phthalates and the purification effects of current water treatment process on phthalates were carried out.Methods The water samples of source water and finished water were determined for phthalate by comparative method.5 kinds of isomers of phthalate in water samples were detected by gas chromatography technique.Results In treated water samples the detectable rate and maximum contents in water samples were 100% and 76μg/L for di-n-butyl phthalate,50% and 17 μg/L for di(2-ethylhexyl) phthalate respectively.Di-methyl phthalate,di-ethyl phthalate and butyl benzyl phthalate were not found in water samples.There was no significant difference in geometric means of the contents of phthalates between source water (19.74μg/L) and finished water (18.35 μg/L),P>0.05.Conclusion The main pollutants of phthalates were di-nbulyl phthalate and di(2-ethylhexyl) phthalate in municipal water supply system.The effectiveness of removing phthalates from drinking water by current water treatment process in city and town was not satisfied.The water treatment process special for removing phthatates from drinking water should be studied and explored in further.%目的了解邻苯二甲酸酯类化合物对城镇供水的污染情况以及现行水处理工艺对该类物质的净化效果。方法采用处理前、后对照的方法,对源水和出厂水进行检测。色谱分析测试邻苯二甲酸酯类化合物五只异构体。结果出厂水中邻苯二甲酸二丁酯检出率100%,最高含量达76 μg/L。邻苯二甲酸二(2-乙基己基)酯检出率50%,最高含量17μg/L;邻苯二甲酸二甲酯、邻苯二甲酸二乙酯和邻苯二甲酸丁基苄酯三只异构体均未测出。源水中邻苯二甲酸酯类化合物的平均含量(G)为19.74 μ/L,出厂水18.35μ/L,两者差别无显著意义(P>0.05)。结论城镇供水中的邻苯二甲酸酯类化合物污染以邻苯

  7. 焉耆盆地绿洲区水体硝态氮污染现状分析与评价%Current Situation of Nitrate Nitrogen Contamination in Water Body of the Oasis Area of Yanqi Basin

    Institute of Scientific and Technical Information of China (English)

    汪昌树; 杨鹏年; 于宴民; 魏光辉

    2016-01-01

    To study the current status of the nitrate nitrogen contamination in water body of the oasis area of Yanqi Basin,through field sampling and laboratory analysis,the nitrate nitrogen concentration of 6 5 samples for surface water and 281 samples for different depth of groundwater in the oasis of Yanqi Basin were measured,and the statistical analysis method was used to compare and analyze.The results indicated that the average level of nitrate nitrogen content in water body of the oasis area of Yanqi Basin was low with 2.69 mg/L,the water quality was in good condition,but the nitrate nitrogen concentration had signifi-cant differences among water body of different area and type;the water quality of rivers and reservoirs was in good condition,the drainage canal in farmland had higher nitrate nitrogen concentration,the nitrate ni-trogen pollution for part of drainage was not optimistic;the nitrate nitrogen concentration in groundwater was negatively correlated with the embedded depth,the order of average nitrate nitrogen concentration was:aeration zone water>hand-pumping well water>irrigation well water>drinking well water.The ni-trate nitrogen concentration of hand-pumping in towns was significantly lower than that of irrigation dis-tricts,the grain planting area was significantly lower than vegetable planting area through synthetic analy-sis,the nitrogen fertilizer application was closely related to the nitrate nitrogen in groundwater.The in-crease of nitrogen fertilizer application and low utilization are the main reasons to cause the nitrate nitrogen contamination in groundwater of oasis area of Yanqi Basin in recent years.%为研究焉耆盆地绿洲区水体硝态氮的污染现状,通过野外采样及室内分析,对绿洲区地表水(65个)、不同埋深地下水(281个)的硝态氮含量进行测定,并利用统计分析的方法进行了对比分析。结果表明,绿洲区水体硝态氮含量总体水平较低,为2.69 mg/L,水质状况良好,但不同水

  8. Water physical and chemical data from current meter and bottle casts from the H.J.W. FAY and other platforms as part of the Ocean Continental Shelf - Mid Atlantic (OCS - Mid Atlantic) project, 16 May 1977 - 15 September 1977 (NODC Accession 7800386)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physical and chemical data were collected using current meter and bottle casts from the H.J.W. FAY and other platforms from May 16, 1977 to September 15, 1977....

  9. Water physical, chemical, and benthic organisms data from current meter and bottle casts from the H.J.W. FAY and CAPE HENLOPEN as part of the Ocean Continental Shelf - Mid Atlantic (OCS - Mid Atlantic) project, 03 November 1976 - 15 September 1977 (NODC Accession 7800319)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physical, chemical, and benthic organisms data were collected using current meter and bottle casts from the H.J.W.FAY and CAPE HENLOPEN from November 3, 1976...

  10. Current, CTD, and other data from the YAQUINA and other platforms from the coastal waters of Washington/Oregon as part of the International Decade of Ocean Exploration / Coastal Upwelling Ecosystems Analysis (IDOE/CUEA) from 28 January 1975 to 01 September 1975 (NODC Accession 7800403)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current, CTD, and other data were collected from the YAQUINA and other platforms from the coastal waters of Washington/Oregon from 28 January 1975 to 01 September...

  11. Supercritical water

    CERN Document Server

    Marcus, Yizhak

    2012-01-01

    Discover the many new and emerging applications of supercritical water as a green solvent Drawing from thousands of original research articles, this book reviews and summarizes what is currently known about the properties and uses of supercritical water. In particular, it focuses on new and emerging applications of supercritical water as a green solvent, including the catalytic conversion of biomass into fuels and the oxidation of hazardous materials. Supercritical Water begins with an introduction that defines supercritical fluids in general. It then defines supercritical wa

  12. Shared marine waters of British Columbia and Washington: A scientific assessment of current status and future trends in resource abundance and environmental quality in the strait of Juan de Fuca, Strait of Georgia, and Puget Sound

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The British Columbia/Washington Marine Science Panel was created in 1993 to evaluate the condition of the marine environment in the Strait of Georgia, Strait of Juan de Fuca, and Puget Sound region on both sides of the international boundary. The panel was asked to produce a report on the current condition of, and trends in, the marine waters shared by the province and state. This report describes the principles followed; the region of concern; physical exchange mechanisms in the transboundary region; movements, status, and trends of transboundary biological resource populations; anthropogenic impacts on the ecosystem and humans; ecosystem sensitivity and future scope of anthropogenic impacts; and degree of harm and management priorities.

  13. Analysis on Current Treatment Method of Heavy Metal Pollution in Water Bodies and Emergency Disposal Strategy%水体重金属污染处理方法现状分析与应急处置策略

    Institute of Scientific and Technical Information of China (English)

    郑彤; 杜兆林; 贺玉强; 王鹏

    2013-01-01

    In order to cope with heavy metal pollution accident in water fast and effectively, the current treatment methods of lead, mercury, chromium, cadmium and metalloid arsenic pollutants which are mainly prevented and controlled in the Twelfth Five-Year Plan were reviewed. The applicability of the treatment methods to emergency disposal was analyzed. A research strategy for emergency disposal of heavy metal pollution accident in water was proposed.%为快速有效地应对水体突发性重金属污染事故,对“十二五”规划中重点防控的铅、汞、铬、镉和类金属砷等重金属污染物的处理方法研究现状进行了介绍,并对这些处理方法的应急现场适用性进行了分析,提出了突发性水体重金属污染事故应急处置方法的研究方略.

  14. Common catabolic enzyme patterns in a microplankton community of the Humboldt Current System off northern and central-south Chile: Malate dehydrogenase activity as an index of water-column metabolism in an oxygen minimum zone

    Science.gov (United States)

    González, R. R.; Quiñones, R. A.

    2009-07-01

    An extensive subsurface oxygen minimum zone off northern and central-south Chile, associated with the Peru-Chile undercurrent, has important effects on the metabolism of the organisms inhabiting therein. Planktonic species deal with the hypoxic and anoxic environments by relying on biochemical as well as physiological processes related to their anaerobic metabolisms. Here we characterize, for the first time, the potential enzymatic activities involved in the aerobic and anaerobic energy production pathways of microplanktonic organisms (catabolic pathways in the oxygen minimum zone. Malate dehydrogenase had the highest oxidizing activity of nicotinamide adenine dinucleotide (reduced form) in the batch of catabolic enzymatic activities assayed, including potential pyruvate oxidoreductases activity, the electron transport system, and dissimilatory nitrate reductase. Malate dehydrogenase correlated significantly with almost all the enzymes analyzed within and above the oxygen minimum zone, and also with the oxygen concentration and microplankton biomass in the water column of the Humboldt Current System, especially in the oxygen minimum zone off Iquique. These results suggest a possible specific pattern for the catabolic activity of the microplanktonic realm associated with the oxygen minimum zone spread along the Humboldt Current System off Chile. We hypothesize that malate dehydrogenase activity could be an appropriate indicator of microplankton catabolism in the oxygen minimum zone and adjacent areas.

  15. 某核电厂常规岛循环水管道外加电流阴极保护设计%Design of Impressed Current Cathodic Protection for Conventional Island Circulating Water Pipeline in a Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    李川; 赵志军

    2016-01-01

    The conventional island circulating water pipeline in a nuclear power plant uses heavy corrosion protection coating and impressed current cathodic protection. The paper introduces the theory,the design principle,main pa-rameters and material selection of impressed current cathodic protection,among other techniques,hoping to provide reference for other coastal power plants.%某核电厂常规岛循环水管道采用重防腐涂料与外加电流阴极保护联合防护。本文对其选择外加电流阴极保护的理论依据,以及其外加电流技术的设计原则、主要参数选取以及设备材料选型等技术要点进行介绍,以供其他滨海电厂循环水系统管道防腐设计参考。

  16. Caractéristiques dynamiques d'un écoulement co-courant eau-huile-air Dynamic Characteristics of a Co-Current Water-Oil-Air Flow

    Directory of Open Access Journals (Sweden)

    Fabre J.

    2006-11-01

    Full Text Available Les auteurs présentent une étude expérimentale sur la structure locale d'un écoulement quasi parallèle co-courant à trois phases : eau-huile-air. L'objectif principal de cette étude est la détermination des contraintes de cisaillement aux interfaces eau-huile et air-huile. L'écoulement est réalisé dans un canal rectangulaire équipé d'une soufflerie et d'un système pour séparer et recycler les phases liquides, en continu. Les résultats expérimentaux présentés sont relatifs aux régimes lisses des interfaces : les vitesses et leurs fluctuations sont mesurées par anémométrie laser dans l'eau et anémométrie à film chaud dans l'air. Les résultats sur l'interface gaz-liquide confirment que l'écoulement est identique à celui sur une paroi se déplaçant à la vitesse du liquide à la surface. Dans l'eau, la structure est celle d'un écoulement de Couette turbulent. Près de la paroi inférieure et près de l'interface liquide-liquide les échelles locales de vitesse et de longueur regroupent assez bien les mesures de vitesses et de fluctuations turbulentes longitudinales. This article is an experimental investigation, of the local structure of a quasi-parallel co-current three-phase flow invoiving water, oil and air. The main aim of this investigation is to determine the shear stresses on the water-oil and air-oil interfaces. Flow is induced in a rectangular channel equipped with a wind tunnel and a system for separating and recirculating the liquid phases continuously. The experimental results that are given have to do with smooth interface regimes. Velocities and their fluctuations are measured by laser anemometry in water and by hot-wire anenometry in air. The results on the gas-liquid interface confirm that flow is identical to flow over a wall moving at the velocity of the liquid on the surface. In water, the structure is that of a turbulent Couette flow. Near the bottom wall and near the liquid-liquid interface, the

  17. Current Situation and Healthy Culture Proposals of Cold Water Fish Culture in Shandong Province%山东省冷水性鱼类养殖现状及健康养殖建议

    Institute of Scientific and Technical Information of China (English)

    于振海; 陈有光; 靖莹

    2011-01-01

    The current situation of cold water fish, including area, yield, species and culture mode and the technique problem in culture, was investigated by on-the-spot investigation of cold water fish culture in Shandong province. It was suggested that the healthy culture might develop from recirculating aquaculture, fry breeding, disease prevention and feed nutrition according to data analysis for Shandong culture industry, and the cold water fish development at home and abroad. It was also proposed carefully conducting the research and promotion of hybrid sturgeon, persisting in the adult fish culture and reserved broodstock cultivation should be persisted, using the advanced culture mode of 'company, base and peasant household' and greatly enhancing the scale of deeply processing to form the industry chain of 'culture-process-sale' and promoting the healthy development of the cold water fish culture.%对山东省境内的冷水性鱼类养殖企业进行了实地调研,主要涉及内容为冷水性鱼类的养殖面积、产量、养殖品种、养殖模式等现状以及在养殖过程中遇到的技术问题.在对山东省整个区域的资料汇总、统计分析的基础上,根据国内外冷水性鱼类的发展趋势,结合山东省自然资源条件以及养殖经验,提出从循环水养殖、苗种繁育、病害防治及饲料营养等角度开展健康养殖的建议.并且在苗种繁育的工作中需谨慎开展杂交鲟的研究与推广;借鉴成功经验,开展“公司+基地+农户”养殖模式;注重成鱼养殖以及后备亲鱼的培育;大力提升冷水性鱼类深加工规模,形成“繁养-加工-销售”的产业链,推动冷水性鱼类养殖产业的健康发展.

  18. Coastal tomographic mapping of nonlinear tidal currents and residual currents

    Science.gov (United States)

    Zhu, Ze-Nan; Zhu, Xiao-Hua; Guo, Xinyu

    2017-07-01

    Depth-averaged current data, which were obtained by coastal acoustic tomography (CAT) July 12-13, 2009 in Zhitouyang Bay on the western side of the East China Sea, are used to estimate the semidiurnal tidal current (M2) as well as its first two overtide currents (M4 and M6). Spatial mean amplitude ratios M2:M4:M6 in the bay are 1.00:0.15:0.11. The shallow-water equations are used to analyze the generation mechanisms of M4 and M6. In the deep area, where water depths are larger than 60 m, M4 velocity amplitudes measured by CAT agree well with those predicted by the advection terms in the shallow water equations, indicating that M4 in the deep area is predominantly generated by the advection terms. M6 measured by CAT and M6 predicted by the nonlinear quadratic bottom friction terms agree well in the area where water depths are less than 20 m, indicating that friction mechanisms are predominant for generating M6 in the shallow area. In addition, dynamic analysis of the residual currents using the tidally averaged momentum equation shows that spatial mean values of the horizontal pressure gradient due to residual sea level and of the advection of residual currents together contribute about 75% of the spatial mean values of the advection by the tidal currents, indicating that residual currents in this bay are induced mainly by the nonlinear effects of tidal currents. This is the first ever nonlinear tidal current study by CAT.

  19. The resurrection of a species: Sarcocystis bovifelis Heydorn et al., 1975 is distinct from the current Sarcocystis hirsuta in cattle and morphologically indistinguishable from Sarcocystis sinensis in water buffaloes.

    Science.gov (United States)

    Gjerde, Bjørn

    2016-01-01

    should again be used not only for the species originally described from cattle in Germany but also for morphologically indistinguishable taxa recently reported from cattle under the names S. sinensis and S. rommeli. Because of the morphological similarity between S. bovifelis and S. sinensis, it is likely that cats also act as definitive hosts for S. sinensis. The present paper also gives a thorough review of all research in the 1970s pertaining to S. bovifelis, including its development in cats and cattle; a review of reports of S. bovifelis-like sarcocysts in cattle, water buffaloes and other hosts; and a review of reports of the taxon currently named S. hirsuta in cattle. The usage of the name S. sinensis versus Sarcocystis dubeyi for the S. bovifelis-like taxon in water buffaloes is discussed, and the latter name is found to represent a nomen dubium since the original description concerned a mixture of a S. sinensis- and a Sarcocystis hominis-like species. Based on available transmission (TEM) and scanning electron microscopy (SEM) images, the three-dimensional configuration of the cyst wall protrusions of S. bovifelis/S. sinensis and the current S. hirsuta has been inferred and is described. The protrusions of S. bovifelis/S. sinensis are shaped like soft plastic tubes, having a cylindrical basal portion and a flattened distal portion, making them prone to fold over. The protrusions of the current S. hirsuta are thin, flattened and flexible rectangular structures (like a soft cover note book), which are attached to the cyst surface with a narrow stalk. The appearance of both types of protrusions in ultrathin sections viewed by TEM is highly dependent on how the sarcocysts and the protrusions themselves have been sectioned.

  20. 带聚能垂直轴水轮机组间耦合特性的试验研究%Experimental Study of a New Vertical Axis Water Current Device

    Institute of Scientific and Technical Information of China (English)

    孙晓晶; 罗大海; 黄典贵; 吴国庆

    2012-01-01

    A conventional Savonius rotor has many advantages over others in that its constructions are simpler and cheaper; it is independent of the fluid direction and has a good starting torque at lower wind or water speeds. However, Savonius rotors are not commonly used as wind turbines or water current power generating devices because of its relatively low energy conversion efficiency. Thus, how to improve the performance of Savonius rotor is a hot research topic attracting a growing attention in the field of renewable energy utilization. Previous research suggests that a mutual coupling effect exists between two Savonius rotors when rotating side by side and this effect can increase both rotors' power output. Therefore, based on this fact, a new water current power generating device composed of two Savonius rotors and collect-shield plates is designed in this paper. A model of this device was constructed and tested in a water tank. Experimental results showed that with such a structure, the power output of each Savonius rotor can be increased by as much as 38%. In addition, the influences of the lateral distance between two Savonius rotors and the angle of collect-shield plate relative to the incoming flow on this efficiency improvement in Savonius rotor were also studied in the present experiments.%虽然传统的垂直轴萨沃纽斯(Savonius)转子具有结构简单、自启动性能好等优点,但是其能量转换效率较低,因而其作为风能、水流能转换装置的使用并不广泛。如何提高Savonius转子的性能是目前国内外新能源研究领域一个十分引人关注的课题。大量的研究表明,两个并列旋转的Savonius转子间存在着一定的耦合作用,这种作用有助于提高单个转子的做功效率。在此基础上,本文提出了一种具用双Savonius转子,在外侧带有聚能一遮蔽板结构的新型水流能转换装置,并对这种装置的模型进行了水槽试验。试验结果表明:

  1. Current-induced membrane discharge

    CERN Document Server

    Andersen, M B; Mani, A; Bruus, H; Biesheuvel, P M; Bazant, M Z

    2012-01-01

    Possible mechanisms for over-limiting current (OLC) through aqueous ion-exchange membranes (exceeding diffusion limitation) have been debated for half a century. Flows consistent with electro-osmotic instability (EOI) have recently been observed in microfluidic experiments, but the existing theory neglects chemical effects and remains to be quantitatively tested. Here, we show that charge regulation and water self-ionization can lead to OLC by "current-induced membrane discharge" (CIMD), even in the absence of fluid flow. Salt depletion leads to a large electric field which expels water co-ions, causing the membrane to discharge and lose its selectivity. Since salt co-ions and water ions contribute to OLC, CIMD interferes with electrodialysis (salt counter-ion removal) but could be exploited for current-assisted ion exchange and pH control. CIMD also suppresses the extended space charge that leads to EOI, so it should be reconsidered in both models and experiments on OLC.

  2. No Watered Down Solution

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Droughts and floods have plagued the Chinese people for the entire summer. Along with alarming news of toxic spills in rivers and polluted water, the current situation of China's water resources is extremely worrying. Threatened by global warming, water pollution and soil erosion, sustainable development in China is becoming more difficult to maintain as the precious water resources are threatened.

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

    Science.gov (United States)

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

    2014-01-01

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

  4. Assessment of Current Cathodic Protection System of a Circulating Water Debris Filter in the Power Plant%电厂循环水碎屑过滤器现行阴极保护系统的评估

    Institute of Scientific and Technical Information of China (English)

    王文奋; 孙永亮; 刘晓军

    2014-01-01

    通过对某电厂过滤器的运行环境、牺牲阳极种类、阳极的设计计算、阳极的安装、运行现状分析,确认其循环水系统碎屑过滤器现有阴极保护系统大体满足防腐蚀的要求。为更好地运行,建议其更换牺牲阳极种类并对不溶解的阳极进行成分分析及电化学性能测试,对采购的阳极进行抽样检测,对每只安装的新阳极测量电连接。%Operating environment, type, design, installation,operation status of sacrificial anode were applied to analysis the effect of current cathodic protection system of a circulating water debris filter in the power plant,result shows that the system generally meet the requirements of anti-corrosion. In order to better operation, improvement measures, such as replacing the sacrificial anode and analysising the components and testing electrochemical performance of the insoluble anode, Sampling for testing and measuring the anode electrical connection were proposed.

  5. 水利单位职工培训教育现状及对策分析%Analysis on Current Situations and Countermeasures of Staff Training in Water Conservancy Institutions

    Institute of Scientific and Technical Information of China (English)

    李俊

    2016-01-01

    Through research and investigation ,great demand and prominent contradiction have been found in the staff training of water conservancy institutions .The current situations of staff training such as fuzzy training consciousness ,obvious utility and practicability ,backward training programs ,short training funds are analyzed ;and corresponding improvement proposals are put forward ,including strengthening training consciousness ,establishing long‐term training mecha‐nism ,making personalized plans and managing special funds specially .The effective ways to a‐chieve seamless joint between training need and colleges resources need to be explored further .%经过调研发现,水利职工教育培训需求量很大,矛盾也较为突出。分析了当前水利单位职工培训教育的现状,体现为培训意识模糊,职工培训需求的功利性、实用性突出,培训方案落后,培训经费短缺,并针对性地提出了改进建议,强化培训认识,建立培训长效机制,量身打造方案,专项经费专管,尚需进一步探索促进培训需求和院校资源无缝对接的有效方案。

  6. 水流作用下重力式网箱浮架结构的动力响应研究%Study on the dynamic response of float collar of gravity cages subject to water currents

    Institute of Scientific and Technical Information of China (English)

    李坤鹏; 许条建; 董国海; 赵云鹏

    2016-01-01

    近年来深水网箱养殖设施得到了广泛的应用,浮架作为网箱结构的重要组成部分,其安全性对网箱的设计至关重要。基于有限单元法采用SHELL单元建立了浮架结构的荷载变形数值模型,对水流作用下浮架的应力和变形进行了数值模拟,并开展物理模型试验对该数值模型进行验证。结果表明,该数值模型可以准确模拟浮架的变形,采用该数值模型,分析了不同流速条件下浮架的变形和应力,数值模拟结果显示:随着流速的增加,浮架的变形和应力逐渐增加。相同流速条件下,注水下潜后,浮架的应力和变形能够显著减小;因此,在强流条件下,可以采用浮架注水的方式,使浮架处于下潜状态,以改善浮架结构的变形和应力分布。%The offshore culture cage has been widely applied in the open sea recently .Floating collar is an important component for the fish cage structure , and the safety of floating collar is very important for the design of fish cage .The numerical model of floating collar was built by using the SHELL element based on the finite element method , the stress and deformation of the floating collar in current were simulated , and the numerical model were verified through the physical model experiments .The results showed that the numerical model could accurately simulate the deformation of the floating collar .Based on the numerical model of the floating collar, the stress and deformation of the floating collar under different water velocity were analyzed .The numerical simulation results indicated that the stress and deformation of floating collar were increased gradually with the increase of the velocity .The maximum deformation and stress of the floating collar in the floating condition was significantly larger than that for the floating collar in the submerge condition .In conclusion , the deformation and stress distribution of floating collar under

  7. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2011-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  8. Current-Induced Membrane Discharge

    OpenAIRE

    Andersen, MB; Soestbergen, van, M Michiel; A Mani; Bruus, H.; Biesheuvel, PM; Bazant, MZ

    2012-01-01

    Possible mechanisms for overlimiting current (OLC) through aqueous ion-exchange membranes (exceeding diffusion limitation) have been debated for half a century. Flows consistent with electro-osmotic instability have recently been observed in microfluidic experiments, but the existing theory neglects chemical effects and remains to be quantitatively tested. Here, we show that charge regulation and water self-ionization can lead to OLC by “current-induced membrane discharge” (CIMD), even in the...

  9. Visualizing water

    Science.gov (United States)

    Baart, F.; van Gils, A.; Hagenaars, G.; Donchyts, G.; Eisemann, E.; van Velzen, J. W.

    2016-12-01

    A compelling visualization is captivating, beautiful and narrative. Here we show how melding the skills of computer graphics, art, statistics, and environmental modeling can be used to generate innovative, attractive and very informative visualizations. We focus on the topic of visualizing forecasts and measurements of water (water level, waves, currents, density, and salinity). For the field of computer graphics and arts, water is an important topic because it occurs in many natural scenes. For environmental modeling and statistics, water is an important topic because the water is essential for transport, a healthy environment, fruitful agriculture, and a safe environment.The different disciplines take different approaches to visualizing water. In computer graphics, one focusses on creating water as realistic looking as possible. The focus on realistic perception (versus the focus on the physical balance pursued by environmental scientists) resulted in fascinating renderings, as seen in recent games and movies. Visualization techniques for statistical results have benefited from the advancement in design and journalism, resulting in enthralling infographics. The field of environmental modeling has absorbed advances in contemporary cartography as seen in the latest interactive data-driven maps. We systematically review the design emerging types of water visualizations. The examples that we analyze range from dynamically animated forecasts, interactive paintings, infographics, modern cartography to web-based photorealistic rendering. By characterizing the intended audience, the design choices, the scales (e.g. time, space), and the explorability we provide a set of guidelines and genres. The unique contributions of the different fields show how the innovations in the current state of the art of water visualization have benefited from inter-disciplinary collaborations.

  10. Improved water does not mean safe water

    Science.gov (United States)

    MacDonald, L. H.; Guo, Y.; Schwab, K. J.

    2012-12-01

    This work presents a model for estimating global access to drinking water that meets World Health Organization (WHO) water quality guidelines. The currently accepted international estimate of global access to safe water, the WHO and United Nations Children's Fund's (UNICEF) Joint Monitoring Program (JMP) report, estimates the population with access to water service infrastructure that is classified as improved and unimproved. The JMP report uses access to improved water sources as a proxy for access to safe water, but improved water sources do not always meet drinking water quality guidelines. Therefore, this report likely overestimates the number of people with access to safe water. Based on the JMP estimate, the United Nations has recently announced that the world has reached the Millennium Development Goal (MDG) target for access to safe water. Our new framework employs a statistical model that incorporates source water quality, water supply interruptions, water storage practices, and point of use water treatment to estimate access to safe water, resulting in a figure that is lower than the JMP estimate of global access to safe water. We estimate that at least 28% of the world does not have access to safe water today, as compared to the JMP estimate of 12%. These findings indicate that much more work is needed on the international scale to meet the MDG target for access to safe water.

  11. Saturn's Other Ring Current

    Science.gov (United States)

    Crary, F. J.

    2014-04-01

    Saturn's main rings orbit the planet within an atmosphere and ionosphere of water, oxygen and hydrogen, produced by meteoritic impacts on and ultraviolet photodesorbtion of the ring particles [Johnson et al., 2006; Luhmann et al., 2006; Tseng et al., 2010]. The neutral atmosphere itself has only been tentatively detected through ultraviolet fluorescents of OH [Hall et al., 1996] while the ionosphere was observed in situ by the Cassini spacecraft shortly after orbital insertion [Coates et al.,2005; Tokar et al. 2005, Waite et al. 2005]. Although the plasma flow velocity of this ionosphere is not well-constrained, but the close association with the rings suggests that its speed would be couppled to the keplarian velocity of the rings themselves. As a result, the motion of the plasma through Saturn's magnetic field would produce an induced voltage, oriented away from the planet outside synchronous orbit and towards the planet inside synchronous orbit. Such a potential could result in currents flowing across the ring plane and closeing along magnetic field lines and through Saturn's ionosphere at latitudes between 36o and 48o. Cassini observations of whistler-mode plasma wave emissions [Xin et al.,2006] centered on synchronous orbit (1.76 Rs, mapping to 41o latitude) have been interpreted as a product of field-aligned electron beams associated with such a current. This presentation will investigate the magnitude of these currents and the resulting Joule heating of the ionosphere. An important constraint is that no auroral ultraviolet emissions have been observed at the relevant latitudes. In contrast, Joule heating could affect infrared emissions from H3+. Variations in H3+ emission associated with Saturn's rings have been reported by O'Donoghue et al., 2013, and interpreted as a result of ring "rain", i.e. precipitating water group species from the rings which alter ionosphereic chemistry and H3+ densities. As noted by O'Donoghue et al., this interpretation may be

  12. Submesoscale cyclones in the Agulhas current

    Science.gov (United States)

    Krug, M.; Swart, S.; Gula, J.

    2017-01-01

    Gliders were deployed for the first time in the Agulhas Current region to investigate processes of interactions between western boundary currents and shelf waters. Continuous observations from the gliders in water depths of 100-1000 m and over a period of 1 month provide the first high-resolution observations of the Agulhas Current's inshore front. The observations collected in a nonmeandering Agulhas Current show the presence of submesoscale cyclonic eddies, generated at the inshore boundary of the Agulhas Current. The submesoscale cyclones are often associated with warm water plumes, which extend from their western edge and exhibit strong northeastward currents. These features are a result of shear instabilities and extract their energy from the mean Agulhas Current jet.

  13. Water use in California

    Science.gov (United States)

    Brandt, Justin; Sneed, Michelle; Rogers, Laurel Lynn; Metzger, Loren F.; Rewis, Diane; House, Sally F.

    2014-01-01

    As part of the USGS National Water Use Compilation, the California Water Science Center works in cooperation with local, State, and Federal agencies as well as academic and private organizations to collect and report total water withdrawals for California. The 2010 California water use data are aggregated here, in this website, for the first time. The California Water Science Center released these data ahead of the online USGS National Water Use Compilation circular report, in response to increased interest associated with current drought conditions. The national report is expected to be released late in 2014. The data on this website represents the most current California water use data available in the USGS National Water Use Compilation. It contains a section on water use in California for 2010. Water-use estimates are compiled by withdrawal source type, use category, and county. Withdrawal source types include groundwater, both fresh and saline,

  14. Current-voltage curve of a bipolar membrane at high current density

    NARCIS (Netherlands)

    Aritomi, T.; Boomgaard, van den Th.; Strathmann, H.

    1996-01-01

    The potential drop across a bipolar membrane was measured as a function of the applied current density. As a result, an inflection point was observed in the obtained current-voltage curve at high current density. This inflection point indicates that at high current densities water supply from outsid

  15. Current-voltage curve of a bipolar membrane at high current density

    NARCIS (Netherlands)

    Aritomi, T.; van den Boomgaard, Anthonie; Strathmann, H.

    1996-01-01

    The potential drop across a bipolar membrane was measured as a function of the applied current density. As a result, an inflection point was observed in the obtained current-voltage curve at high current density. This inflection point indicates that at high current densities water supply from

  16. Water Policies of Turkey

    Directory of Open Access Journals (Sweden)

    Hakan Istanbulluoglu

    2011-06-01

    Full Text Available Water is one of our most critical resources. Civilization has historically flourished around major waterways. The most important uses of water are; agricultural, industrial and domestic use. This critical resource is under threat around the world. In the next 20 years, the quantity of water available to everyone is predicted to decrease by 30%. 40% of the world\\\\\\\\\\\\\\'s inhabitants currently have insufficient fresh water for minimal hygiene. In 2000 more than 2.2 million people died from waterborne diseases. Water politics is politics affected by water and water resources. There are connections between water resources, water systems, and international security and conflict. Today, water is a strategic resource in the globe and an important element in many political conflicts. Turkey can be faced severe water-stress in the near future. Therefore Turkey has to develop realistic and feasible water policy for future generations. [TAF Prev Med Bull 2011; 10(3.000: 327-338

  17. ESTADO DEL CONOCIMIENTO DE LAS CONCENTRACIONES DE MERCURIO Y OTROS METALES PESADOS EN PECES DULCEACUÍCOLAS DE COLOMBIA Current State of Knowledge of the Concentration of Mercury and Other Heavy Metals in Fresh Water Fish in Colombia

    Directory of Open Access Journals (Sweden)

    NÉSTOR JAVIER MANCERA-RODRÍGUEZ

    2006-06-01

    fasciatus, Colossoma bidens, Gambusia affinis y Grundulus bogotensis.One of the most important environmental problems in the country refers to the indiscriminate use of chemical precursors in illicit activities, the use of heavy metals as mercury in mining activities, the spill of served waters and another type of compound related with the industrial activities of raw and the inadequate agricultural practices. This has led to chemical contamination especially by heavy metals, considered one of the most dangerous for the aquatic ecosystems and the present species in them. Fish have the capacity to store these compounds in their organism in a concentration higher than that in the surrounding environment (water, therefore, their concentration are important indicators of the contamination level, but also this implies that their consumption can become a serious health problem for the populations that feeds from them. The concentration of heavy metals in fish of fresh water is better known in the basin of the Magdalena river, especially in the region of the Mojana and in the marshes of the south of the Department of Bolivar where the levels of contamination by mercury and other metals has been studied due to the development of multiple industrial activities, including gold mining and petrochemical industries. However, little is known in the country about the problem generated by the disposal heavy metals in rivers and lakes and their impact on the fish resource, deterioration of ecosystems and human health. Based in the current norms bio-assays have been used to check the effects of the aquatic contamination on fresh waters fish and the evaluation of at least three parameters (heavy metals, temperature, effluents in eight species of fresh waters fish: Carassius auratus, Oreochromis spp., Piractus brachypomus, Prochilodus magdalenae, Astyanax fasciatus, Colossoma bidens, Gambusia affinis and Grundulus bogotensis.

  18. Water, Water Everywhere

    Science.gov (United States)

    Keeler, Rusty

    2009-01-01

    Everybody knows that children love water and how great water play is for children. The author discusses ways to add water to one's playscape that fully comply with health and safety regulations and are still fun for children. He stresses the importance of creating water play that provides children with the opportunity to interact with water.

  19. Water, Water Everywhere

    Science.gov (United States)

    Keeler, Rusty

    2009-01-01

    Everybody knows that children love water and how great water play is for children. The author discusses ways to add water to one's playscape that fully comply with health and safety regulations and are still fun for children. He stresses the importance of creating water play that provides children with the opportunity to interact with water.

  20. Estado del conocimieno de las concentraciones de mercurio y otros metales pesados en peces dulceacuícolas de Colombia Current State of Knowledge of the Concentration of Mercury and Other Heavy Metals in Fresh Water Fish in Colombia

    Directory of Open Access Journals (Sweden)

    Álvarez-León Ricardo

    2006-06-01

    fasciatus, Colossoma bidens, Gambusia affinis y Grundulus bogotensis.One of the most important environmental problems in the country refers to the indiscriminate use of chemical precursors in illicit activities, the use of heavy metals as mercury in mining activities, the spill of served waters and another type of compound related with the industrial activities of raw and the inadequate agricultural practices. This has led to chemical contamination especially by heavy metals, considered one of the most dangerous for the aquatic ecosystems and the present species in them. Fish have the capacity to store these compounds in their organism in a concentration higher important indicators of the contamination level, but also this implies that their consumption can become a serious health problem for the populations that feeds from them. The concentration of heavy metals in fish of fresh water is better known in the basin of the Magdalena river, especially in the region of the Mojana and in the marshes of the south of the Department of Bolivar where the levels of contamination by mercury and other metals has been studied due to the development of multiple industrial activities, including gold mining and petrochemical industries. However, little is known in the country about the problem generated by the disposal heavy metals in rivers and lakes and their impact on the fish resource, deterioration of ecosystems and human health. Based in the current norms bio-assays have been used to check the effects of the aquatic contamination on fresh waters fish and the evaluation of at least three parameters (heavy metals, temperature, effluents in eight species of fresh waters fish: Carassius auratus, Oreochromis spp., Piractus brachypomus, Prochilodus magdalenae, Astyanax fasciatus, Colossoma bidens, Gambusia affinis and Grundulus bogotensis.

  1. [Study on of the current status of volatile organic compounds pollution in typical rural drinking water and the relationship between its concentration and health of the population, in Huai'an, Jiangsu].

    Science.gov (United States)

    Pan, Enchun; Zhang, Qin; Yang, Fangying; Hu, Wei; Xu, Qiujin; Liang, Cunzhen; He, Yuan; Wang, Chuang

    2014-10-01

    This study was to understand the status of pollution on drinking water, by volatile organic compounds (VOCs), among rural residents living in the basin of Huaihe River. Relationship between the morbidity, morbidity of cancers and VOCs were also explored. 28 villages were chosen from Xuyi,Jinhu, Chuzhou along the Huaihe River, with water samples collected from ditch pond water, shallow wells, deep wells in November-December 2010. VOCs indicators were evaluated according to the Standard Quality GB 5749-2006 for Drinking Water. Methylene chloride, chloroform, benzene and carbon tetrachloride were all detected in 76 water samples. The rates of chloroform, benzene, carbon tetrachloride which exceeding the quality standards were 3.95% , 21.05% and 22.37% , but no significant differences were found among these three water resources in chloroform, benzene or carbon tetrachloride. Results from the correlation analysis showed that benzene had positive correlation with tumor deaths (r = 0.24, P water resources (P > 0.05). Drinking waters for rural residents along the Huaihe River were polluted while VOCs might have related to tumor incidence with potential impact and risk to the health of local residents.

  2. Water Management in Poland

    Directory of Open Access Journals (Sweden)

    Wojciech Majewski

    2015-03-01

    Full Text Available This paper presents the current situation in Polish water resources management. Discussed here are measures taken by the Ministry of Environment to introduce a new water law, as well as reforms of water management in Poland. The state of water resources in Poland are described, and the actions needed to improve this situation, taking into account possible climate changes and their impact on the use of water resources. Critically referred to is the introduction by the Ministry of Environment of charges for water abstraction by hydro power plants, and adverse effects for the energy and water management sectors are discussed.

  3. Sustainability and Water

    Science.gov (United States)

    Sharma, Virender A.

    2009-07-01

    World's population numbered 6.1 billion in 2000 and is currently increasing at a rate of about 77 million per year. By 2025, the estimated total world population will be of the order of 7.9 billion. Water plays a central role in any systematic appraisal of life sustaining requirements. Water also strongly influences economic activity (both production and consumption) and social roles. Fresh water is distributed unevenly, with nearly 500 million people suffering water stress or serious water scarcity. Two-thirds of the world's population may be subjected to moderate to high water stress in 2025. It is estimated that by 2025, the total water use will increase by to 40%. The resources of water supply and recreation may also come under stress due to changes in climate such as water balance for Lake Balaton (Hungary). Conventional urban water systems such as water supply, wastewater, and storm water management are also currently going through stress and require major rethinking. To maintain urban water systems efficiently in the future, a flexibility approach will allow incorporation of new technologies and adaptation to external changes (for example society or climate change). Because water is an essential resource for sustaining health, both the quantity and quality of available water supplies must be improved. The impact of water quality on human health is severe, with millions of deaths each year from water-borne diseases, while water pollution and aquatic ecosystem destruction continue to rise. Additionally, emerging contaminants such as endocrine disruptor chemicals (EDCs), pharmaceuticals, and toxins in the water body are also of a great concern. An innovative ferrate(VI) technology is highly effective in removing these contaminants in water. This technology is green, which addresses problems associated with chlorination and ozonation for treating pollutants present in water and wastewater. Examples are presented to demonstrate the applications of ferrate

  4. 水资源与粮食生产耦合关系研究现状与展望%Current Situation and Prospect of Research on Relationship between Water Resources and Food Production

    Institute of Scientific and Technical Information of China (English)

    柳玉梅; 李九一

    2014-01-01

    粮食安全和水安全对人类生存与发展具有极其重要的意义。以水资源的可持续利用来保障粮食安全已经成为国内外学者关注的焦点,同时也是实现水资源合理配置的迫切要求。本文分别从水量和水质两个方面对水资源与粮食生产的关系进行了回顾和总结,分析了当前研究中存在的问题,认为单纯从水量或水质的角度研究水资源对粮食生产的影响不能满足实际的要求。因此,应在研究水量和水质分别对粮食生产影响的基础上进行耦合,构建综合考虑水质和水量影响的水资源-粮食产量模型。%Food security and water resources play an important role in the subsistence and development of humans .The sustainable use of water resources to ensure food security has become the focus of scholars .It also requires the rational allocation of water re‐source .This paper reviews the relationships between water resources and food production and summarizes them from two aspects of water quantity and quality .It indicates that studying the relationship between food production and water quantity or quality respec‐tively does not meet the requirements of practical applications .Therefore ,the Water-Yield model ,considering both water quantity and water quality ,should be established .

  5. Current profile data collected aboard NOAA Ship Ronald Brown during cruise RB0708 in the North Atlantic Ocean and coastal waters of Florida from 2007-09-11 to 2007-09-22 (NCEI Accession 0131294)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0131294 includes physical underway data collected aboard NOAA Ship Ronald Brown during cruise RB0708 in the North Atlantic Ocean and coastal waters of...

  6. 宁夏引黄灌区农业水价改革现状分析及思考%Analysis and Thoughts to Currently Agricultural Water Price Reform in Ningxia Yellow River Irrigation

    Institute of Scientific and Technical Information of China (English)

    刘思妤; 倪红珍; 张春玲; 陈根发

    2016-01-01

    In recent years,according to the requirements of the Ministry of water resources and the construction of water saving soci-ety in Ningxia Hui Autonomous Region,the irrigation area of Ningxia has achieved certain results by fully implementation of the ag-ricultural water price reform.In combination with the practical situation of irrigation area,this paper introduces in detail the irriga-tion water price reform,irrigation water supply cost and management income situation,analyzed the main problems existing in water price reform,put forward and set up scientific points irrigation,crop ladder water price standard and perfect the relevant supporting policies,organization and management,the concrete Suggestions of infrastructure construction,so as to provide reference for further implementing the reform of water price in Ningxia Yellow River irrigation.%近年来,按照国家水利部和宁夏回族自治区建设节水型社会的要求,宁夏引黄灌区全面推行了农业水价改革,取得了一定成效。结合灌区实际情况,详细介绍了灌区水价改革、灌区供水成本及管理处收益现状,分析水价改革中存在的主要问题,并提出建立分灌区、分作物的阶梯水价标准及完善相关配套政策、组织管理、基础建设的具体建议,旨在为宁夏引黄灌区进一步落实水价改革提供参考依据。

  7. A Review on the Current Situation and Countermeasures of Water-saving Irrigation Technology Extension in China%我国节水灌溉技术推广现状与对策研究综述

    Institute of Scientific and Technical Information of China (English)

    赵文杰; 丁凡琳

    2015-01-01

    目前我国节水灌溉技术的推广和使用取得了一定成果,但其发展潜力仍十分巨大,并且在技术推广过程中存在诸多问题,限制了节水灌溉技术的推广和采纳。管理制度不合理、水权制度不明确、水价机制不健全、农户节水意识不强以及农村传统社会的变迁等都给先进节水灌溉技术的推广带来困难;必须进一步完善制度,增加对节水灌溉技术推广的资金支持,将技术研究和推广与农民需求相结合,才能促使节水灌溉技术的有效推广。%Extension and acceptation of water-saving irrigation technology have got some results in China .While the development po‐tential of water-saving technology is very huge ,and many problems during the extension process have restricted the extension and ac‐ceptation of water-saving irrigation technology .Unreasonable management system ,undefined water rights system ,unsound water price system ,unconsciousness of saving water of farmers and the transformation of traditional rural places all make it difficult to ex‐tend water-saving technology .In order to make the extension of water-saving technology more sufficiently ,it needs to improve the institutional system ,increase financial support and combine the make research and extension of the technology with needs of farmers .

  8. 秦皇岛市农村饮水安全状况调查与管理对策%Current Situation Survey and Management Countermeasures of Rural Drinking Water Safety in Qinhuangdao City

    Institute of Scientific and Technical Information of China (English)

    孙颖

    2013-01-01

    The investigation results of the rural drinking water safety in Qinhuangdao City showed 90% water populations were scattered and obtained water with shallow wells, 100% users disinfected with bleaching powder, but the methods were not standard. The local government didn't organize the water detection .And there is not any sewage treatment plant or waste treatment plant. There were also some other issues such as the lack of sound water supply management system and the weakness of water safety consciousness. Some suggestions were put forward from several aspects, such as increasing investment to improve intensification water supply, establishing diversified management system, setting up the long-term mechanism of water source protection and water quality monitoring and advancing the comprehensive treatment of the countryside pollution so as to strengthen the follow-up management of rural drinking water safety projects and promote the construction of the new socialist countryside.%秦皇岛市农村饮水安全状况调查结果显示,90%受访户采用家庭分散式浅井取水、100%的用户取水后以漂白粉消毒,但消毒剂的投加不规范。当地政府从未组织对水质进行安全检测,农村缺少污水处理和垃圾处理设施,缺少健全的供水管理制度并且饮水安全意识薄弱。可以从加大水利资金投入推进集约化供水、引进权责明晰的多元化管理制度、建立水源地保护和水质监测的长效机制、推进农村污染综合整治等方面解决农村饮水安全问题,加强饮水安全后续管理,推进社会主义新农村建设。

  9. Gravity currents at Ormen Lange

    Energy Technology Data Exchange (ETDEWEB)

    Vikeboe, Frode; Berntsen, Jarle; Furnes, Gunnar

    2001-12-01

    Time series of temperature and velocities at Ormen Lange, located in the Storegga region off mid-Norway, indicate that close to the seabed, at depths ranging from 500-1000 m, large temperature fluctuations are accompanied by short peak values in speed. The extreme events are driven by strong pressure gradients, due to strong atmospheric low pressures and/or internal pressure fronts between warmer Atlantic Water (AW) and colder Norwegian Sea Water (NSW). Along the shelf slope at OL we may get steepening of the iso surfaces of density, separating AW and NSW, due to strong Ekman veering during storms or approaching internal density fronts. During such events the density surfaces tend to undershoot their equilibrium level, and as the forcing weakens, the suppressed water may run up along the shelf slope. In this run up phase, peak values in the velocities are often found. As a result of the run up phase, heavy water may be elevated onto the shelf. Subsequently dense fluid will spread under the influence of forces produced by its own buoyancy and motions of this form are often referred to as gravity currents. They are characterised by the distinctive nature of the front, which consists of a raised head leading a shallower flow behind. The shape of the head and body of the gravity current, along with velocity, depend on a range of parameters. This report investigates the velocities that may occur with parameters of relevance for Ormen Lange. (author)

  10. Water Policies of Turkey

    OpenAIRE

    Hakan Istanbulluoglu; Tayfun Kir

    2011-01-01

    Water is one of our most critical resources. Civilization has historically flourished around major waterways. The most important uses of water are; agricultural, industrial and domestic use. This critical resource is under threat around the world. In the next 20 years, the quantity of water available to everyone is predicted to decrease by 30%. 40% of the world\\\\\\\\\\\\\\'s inhabitants currently have insufficient fresh water for minimal hygiene. In 2000 more than 2.2 million people died from wate...

  11. Current measurement apparatus

    Science.gov (United States)

    Umans, Stephen D.

    2008-11-11

    Apparatus and methods are provided for a system for measurement of a current in a conductor such that the conductor current may be momentarily directed to a current measurement element in order to maintain proper current without significantly increasing an amount of power dissipation attributable to the current measurement element or adding resistance to assist in current measurement. The apparatus and methods described herein are useful in superconducting circuits where it is necessary to monitor current carried by the superconducting elements while minimizing the effects of power dissipation attributable to the current measurement element.

  12. Western Ross Sea continental slope gravity currents

    Science.gov (United States)

    Gordon, Arnold L.; Orsi, Alejandro H.; Muench, Robin; Huber, Bruce A.; Zambianchi, Enrico; Visbeck, Martin

    2009-06-01

    Antarctic Bottom Water of the world ocean is derived from dense Shelf Water that is carried downslope by gravity currents at specific sites along the Antarctic margins. Data gathered by the AnSlope and CLIMA programs reveal the presence of energetic gravity currents that are formed over the western continental slope of the Ross Sea when High Salinity Shelf Water exits the shelf through Drygalski Trough. Joides Trough, immediately to the east, offers an additional escape route for less saline Shelf Water, while the Glomar Challenger Trough still farther east is a major pathway for export of the once supercooled low-salinity Ice Shelf Water that forms under the Ross Ice Shelf. The Drygalski Trough gravity currents increase in thickness from ˜100 to ˜400 m on proceeding downslope from ˜600 m (the shelf break) to 1200 m (upper slope) sea floor depth, while turning sharply to the west in response to the Coriolis force during their descent. The mean current pathway trends ˜35° downslope from isobaths. Benthic-layer current and thickness are correlated with the bottom water salinity, which exerts the primary control over the benthic-layer density. A 1-year time series of bottom-water current and hydrographic properties obtained on the slope near the 1000 m isobath indicates episodic pulses of Shelf Water export through Drygalski Trough. These cold (34.75) pulses correlate with strong downslope bottom flow. Extreme examples occurred during austral summer/fall 2003, comprising concentrated High Salinity Shelf Water (-1.9 °C; 34.79) and approaching 1.5 m s -1 at descent angles as large as ˜60° relative to the isobaths. Such events were most common during November-May, consistent with a northward shift in position of the dense Shelf Water during austral summer. The coldest, saltiest bottom water was measured from mid-April to mid-May 2003. The summer/fall export of High Salinity Shelf Water observed in 2004 was less than that seen in 2003. This difference, if real

  13. Model-based assessment of ecological adaptations of three forest tree species growing in Italy and impact on carbon and water balance at national scale under current and future climate scenarios

    Directory of Open Access Journals (Sweden)

    Vitale M

    2012-10-01

    Full Text Available A semi-empirical model has been used to estimate total net primary productivity, canopy transpiration and the water use efficiency under actual and future climate projections (B1 and A2 IPCC Scenarios of two deciduous (Fagus sylvatica, Quercus cerris and one evergreen tree species (Quercus ilex growing in Italy. In response to changes in the air temperature, the two deciduous species showed a strong reduction of NPP values, whereas the evergreen one showed very limited reductions. Under future warmer conditions, Q. ilex proved to be the best adapted species, probably for its drought-tolerant water-saving strategy, while Q. cerris suffered a reduction of transpiration, due to stomatal closure which was sensitive to the change of evaporative demand. Water Use Efficiency (WUE values did not increase in the B1 and A2 scenarios, indicating a non-conservative water-saving strategy, which likely affected the distribution pattern of Q. cerris under these conditions. Similar functional behaviour have been noted for F. sylvatica, although this species adopted a water spending strategy, typical of species growing in mesic environments, that could represent a risk for survival of beech population under extreme air temperature change. In this respect, the reduced suitable area for this species under the A2 scenario could reduce the possibilities of an upward shift toward higher altitudes.

  14. Ion Mobility Spectrometry for Water Monitoring Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current water quality monitors aboard the International Space Station (ISS) are specialized and provide limited data. The Colorimetric Water Quality Monitor Kit...

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

    Data.gov (United States)

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

  16. Currents in Kaneohe Bay, Oahu, Hawaii 2005 - 2007 in Support of Fresh Water Plume Studies Performed by the Department of Oceanography at the Univesity of Hawaii (NODC Accession 0040251)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Freshwater plumes from rain run-off into Kaneohe Bay is the focus for the investigation. Measurements in this data set are currents as measured by an moored Acoustic...

  17. Annotated Bibliography on Wave-Current Interaction

    Science.gov (United States)

    1983-03-01

    Rotational Fluid," Journal of Computational Physics, Bruges , Belgium, Vol. 24, No. 1, May 1977, pp. 29-42. Keywords. Currents, Vertical Shear; Numerical...realistic representa- tion of the current field and wave history . 14. GADD, G.E., "An Interaction Between Surface Water Waves and a Turbulent

  18. Current and temperature structure of Rihand Lake

    Digital Repository Service at National Institute of Oceanography (India)

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

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

  19. Quantifying Water Stress Using Total Water Volumes and GRACE

    Science.gov (United States)

    Richey, A. S.; Famiglietti, J. S.; Druffel-Rodriguez, R.

    2011-12-01

    Water will follow oil as the next critical resource leading to unrest and uprisings globally. To better manage this threat, an improved understanding of the distribution of water stress is required today. This study builds upon previous efforts to characterize water stress by improving both the quantification of human water use and the definition of water availability. Current statistics on human water use are often outdated or inaccurately reported nationally, especially for groundwater. This study improves these estimates by defining human water use in two ways. First, we use NASA's Gravity Recovery and Climate Experiment (GRACE) to isolate the anthropogenic signal in water storage anomalies, which we equate to water use. Second, we quantify an ideal water demand by using average water requirements for the domestic, industrial, and agricultural water use sectors. Water availability has traditionally been limited to "renewable" water, which ignores large, stored water sources that humans use. We compare water stress estimates derived using either renewable water or the total volume of water globally. We use the best-available data to quantify total aquifer and surface water volumes, as compared to groundwater recharge and surface water runoff from land-surface models. The work presented here should provide a more realistic image of water stress by explicitly quantifying groundwater, defining water availability as total water supply, and using GRACE to more accurately quantify water use.

  20. Cryogenic current leads

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, F.

    1982-01-01

    Theoretical, technical and design questions are examined of cryogenic current leads for SP of magnetic systems. Simplified mathematical models are presented for the current leads. To illustrate modeling, the calculation is made of the real current leads for 500 A and three variants of current leads for 1500 A for the enterprise ''Shkoda.''

  1. Current Situation of the Monitoring Technologies of Heavy Metals in Surface Water%浅析地表水中重金属的监测技术现状

    Institute of Scientific and Technical Information of China (English)

    张晓娇; 李挺

    2015-01-01

    The monitoring of heavy metals in water was the premise of pollution prevention and control. The heavy metals in water were hard to be a creature degradation and will concentrate in the water as time gone by and destruct water quality. They might even enrich in the human body through food chain. the situation of heavy metal pollution in China and the conventional detection method used for determination of heavy metals was simply introduced. The advantages and disadvantages of these methods was analyzed.A reference for establishing and perfecting the heavy metal detection techniques and methods was provided.%水体中重金属的监测是预防和控制重金属污染的前提工作。游离在水体中的重金属难以被生物所降解且会随着时间的推移而在水体中富集,破坏水质甚至通过食物链富集在人体内。文中简单介绍了我国重金属的污染情况和目前用于检测重金属的常规检测方法,并分析了这些方法的优缺点,为建立健全重金属检测技术和方法提供参考。

  2. 山西省地方性砷中毒病区改水降砷调查结果分析%Current situation of the project of water improvement to reduce arsenic in endemic arsenism area in Shanxi province

    Institute of Scientific and Technical Information of China (English)

    吴赵明; 王正辉; 李鹏飞; 荆玉兰; 武敏

    2013-01-01

    目的 了解山西省地方性砷中毒病区改水降砷落实情况,为砷中毒的防治工作提供科学依据.方法 2011年6月,采用调查问卷的方式,在山西省的151个砷中毒病区村调查改水降砷工程使用和运转情况.在病区村采集改水工程水样,水砷测定采用原子荧光法.结果 在151个砷中毒病区村,有126个已经改水,改水率为83.44%;在已改水的病区村中,有22个村不能正常使用.覆盖全省砷中毒病区村的改水降砷工程有33个,正常运行的有23个;正常运行的改水降砷工程覆盖砷中毒病区村110个,受益人口为97 920人,占病区村总人口的46.9%(97 920/208 736).改水工程水含砷超过国家标准(≤0.05 mg/L)的有10个,覆盖31个村,包括15个非病区村和16个病区村,覆盖病区村人口数为24 764人.结论 山西省的地方性砷中毒病区改水力度有待加强,改水工程质量需要提高,工程的后期管理和维护还需要进一步加强.%Objective To investigate the actual situation of implementation of the project to reduce water arsenic in endemic arsenic poisoning areas in Shanxi province,and to provide a scientific basis for prevention and control of the disease.Methods In June 2011,a questionnaire survey of 151 arsenic endemic villages was carried out in Shanxi province.The actual situation of implementation of the project to reduce water arsenic was investigated.Water samples were collected and arsenic level was determined by atomic fluorescence spectrometry.Results In the 151 arsenic poisoning villages 126 villages had changed the water,and the rate was 83.44%.In these villages,22 villages did not use the water improvement utilities properly.Of the 33 water improvement projects to reduce arsenic,23 operated normally.The projects covered 110 villages,beneficiary population of 97 920 people,accounting for 46.9%(97 920/208 736) of the total population.Water arsenic exceeded the national standards(≤0.05 mg/L) in 10

  3. Current interruption transients calculation

    CERN Document Server

    Peelo, David F

    2014-01-01

    Provides an original, detailed and practical description of current interruption transients, origins, and the circuits involved, and how they can be calculated Current Interruption Transients Calculationis a comprehensive resource for the understanding, calculation and analysis of the transient recovery voltages (TRVs) and related re-ignition or re-striking transients associated with fault current interruption and the switching of inductive and capacitive load currents in circuits. This book provides an original, detailed and practical description of current interruption transients, origins,

  4. Water Service Areas - Public Water Supplier's (PWS) Service Areas

    Data.gov (United States)

    NSGIC Education | GIS Inventory — Boundaries of current public water supplier's (PWS) service areas. This data set contains the present service area boundary of the water system and does not contain...

  5. Water Service Areas - Public Water Supplier's (PWS) Service Areas

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Boundaries of current public water supplier's (PWS) service areas. This data set contains the present service area boundary of the water system and does not contain...

  6. Optimal Allocation of Water Resources Based on Water Supply Security

    Directory of Open Access Journals (Sweden)

    Jianhua Wang

    2016-06-01

    Full Text Available Under the combined impacts of climate change and human activities, a series of water issues, such as water shortages, have arisen all over the world. According to current studies in Science and Nature, water security has become a frontier critical topic. Water supply security (WSS, which is the state of water resources and their capacity and their capacity to meet the demand of water users by water supply systems, is an important part of water security. Currently, WSS is affected by the amount of water resources, water supply projects, water quality and water management. Water shortages have also led to water supply insecurity. WSS is now evaluated based on the balance of the supply and demand under a single water resources condition without considering the dynamics of the varying conditions of water resources each year. This paper developed an optimal allocation model for water resources that can realize the optimal allocation of regional water resources and comprehensively evaluate WSS. The objective of this model is to minimize the duration of water shortages in the long term, as characterized by the Water Supply Security Index (WSSI, which is the assessment value of WSS, a larger WSSI value indicates better results. In addition, the simulation results of the model can determine the change process and dynamic evolution of the WSS. Quanzhou, a city in China with serious water shortage problems, was selected as a case study. The allocation results of the current year and target year of planning demonstrated that the level of regional comprehensive WSS was significantly influenced by the capacity of water supply projects and the conditions of the natural water resources. The varying conditions of the water resources allocation results in the same year demonstrated that the allocation results and WSSI were significantly affected by reductions in precipitation, decreases in the water yield coefficient, and changes in the underlying surface.

  7. The Recreational Water Cycle: From Source Water to Tap Water to Spa and Swimming Pool Water: Effects of Disinfectants and Precursors and Implications for Exposure and Toxicity

    Science.gov (United States)

    The current study investigates the effect of different disinfection treatments on the disinfection by-products (DBPs) formed in finished drinking water vs. tap water vs. swimming pool water vs. spa waters. To this end, complete water pathway samples (untreated source waters ->fi...

  8. Estimating risks for water-quality exceedances of total-copper from highway and urban runoff under predevelopment and current conditions with the Stochastic Empirical Loading and Dilution Model (SELDM)

    Science.gov (United States)

    Granato, Gregory; Jones, Susan C.; Dunn, Christopher N.; Van Weele, Brian

    2017-01-01

    The stochastic empirical loading and dilution model (SELDM) was used to demonstrate methods for estimating risks for water-quality exceedances of event-mean concentrations (EMCs) of total-copper. Monte Carlo methods were used to simulate stormflow, total-hardness, suspended-sediment, and total-copper EMCs as stochastic variables. These simulations were done for the Charles River Basin upstream of Interstate 495 in Bellingham, Massachusetts. The hydrology and water quality of this site were simulated with SELDM by using data from nearby, hydrologically similar sites. Three simulations were done to assess the potential effects of the highway on receiving-water quality with and without highway-runoff treatment by a structural best-management practice (BMP). In the low-development scenario, total copper in the receiving stream was simulated by using a sediment transport curve, sediment chemistry, and sediment-water partition coefficients. In this scenario, neither the highway runoff nor the BMP effluent caused concentration exceedances in the receiving stream that exceed the once in three-year threshold (about 0.54 percent). In the second scenario, without the highway, runoff from the large urban areas in the basin caused exceedances in the receiving stream in 2.24 percent of runoff events. In the third scenario, which included the effects of the urban runoff, neither the highway runoff nor the BMP effluent increased the percentage of exceedances in the receiving stream. Comparison of the simulated geometric mean EMCs with data collected at a downstream monitoring site indicates that these simulated values are within the 95-percent confidence interval of the geometric mean of the measured EMCs.

  9. Research on Current Ecological Water Storage for Green Space System and Countermeasures in Hengshui City%衡水市绿地系统生态蓄水现状及对策研究

    Institute of Scientific and Technical Information of China (English)

    刘贺明; 马世梁; 路培; 张宏明

    2013-01-01

    On the basis of systematic research on basic theories of construction of ecological water storage for urban green space system and comparisons of the successful experiences from home and abroad, this article expounds on rainwater utilizations including constructions of puddles, seepage pit, infiltration ditch, reservoir, and seepage pavement. The author explores the combination of city green space construction and stealthy water-accumulation system model in a bid to solve the problem of ecological water storage for green space system in Hengshui city.%在系统研究城市绿地系统生态蓄水建设基本理论的基础上,比较借鉴国内外成功经验,从衡水市的实际出发,提出汇水洼地、渗水坑、渗水沟、蓄水池、渗透铺装等雨水利用措施,探讨城市绿地建设与隐形蓄水系统相结合的模式,为解决目前衡水市城市绿地系统生态蓄水问题提供指导。

  10. NOAA Tidal Current Data for the Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Knowledge of the timing and strength of tidal currents is extremely important for safe navigation in coastal waters. Tidal currents are almost always the strongest...

  11. NOAA Historical Tidal Current Data for the Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Knowledge of the timing and strength of tidal currents is extremely important for safe navigation in coastal waters. Tidal currents are almost always the strongest...

  12. Water Contamination

    Science.gov (United States)

    ... Statistics Training & Education Policy & Recommendations Fast Facts Healthy Water Sites Healthy Water Drinking Water Healthy Swimming Global ... type=”submit” value=”Submit” /> Healthy Water Home Water Contamination Recommend on Facebook Tweet Share Compartir On ...

  13. Drinking Water

    Science.gov (United States)

    ... the safest water supplies in the world, but drinking water quality can vary from place to place. It ... water supplier must give you annual reports on drinking water. The reports include where your water came from ...

  14. Currents for Arbitrary Helicity

    CERN Document Server

    Dragon, Norbert

    2016-01-01

    Using Mackey's classification of unitary representations of the Poincar\\'e group on massles states of arbitrary helicity we disprove the claim that states with helicity |h|>=1 cannot couple to a conserved current by constructing such a current.

  15. Magnetic current sensor

    Science.gov (United States)

    Black, Jr., William C. (Inventor); Hermann, Theodore M. (Inventor)

    1998-01-01

    A current determiner having an output at which representations of input currents are provided having an input conductor for the input current and a current sensor supported on a substrate electrically isolated from one another but with the sensor positioned in the magnetic fields arising about the input conductor due to any input currents. The sensor extends along the substrate in a direction primarily perpendicular to the extent of the input conductor and is formed of at least a pair of thin-film ferromagnetic layers separated by a non-magnetic conductive layer. The sensor can be electrically connected to a electronic circuitry formed in the substrate including a nonlinearity adaptation circuit to provide representations of the input currents of increased accuracy despite nonlinearities in the current sensor, and can include further current sensors in bridge circuits.

  16. Water Use: A Survey

    Science.gov (United States)

    Fleming, Rose Glee; Warden, Jessie

    1976-01-01

    A survey of Florida State University students showed that their current laundry practices generate energy and water over-consumption. The survey also resulted in some concrete suggestions to the students that would improve their conservation practices. (Author/BP)

  17. Current and Current Fluctuations in Quantum Shuttles

    DEFF Research Database (Denmark)

    Jauho, Antti-Pekka; Flindt, Christian; Novotny, Tomas

    2005-01-01

    theoretical tools needed for the analysis, e.g., generalized master equations and Wigner functions, and we outline the methods how the resulting large numerical problems can be handled. Illustrative results are given for current, noise, and full counting statistics for a number of model systems. Throughout...

  18. Controlled current inductors

    Science.gov (United States)

    Thaler, S.

    1970-01-01

    Magnetic permeability and shape of special core inserts are varied to produce desired changes in saturation characteristics of current dependent inductor, thus improving its inductance-to-current properties. Materials and saturation levels of the core pieces are selected to permit a wide variety of relationships between inductance and current.

  19. Environmental Impact Assessment in Sustainable Water Resources ...

    African Journals Online (AJOL)

    Environmental Impact Assessment in Sustainable Water Resources Development: ... the current level of understanding of environmental impact assessment of water ... In the arena of Integrated Water Resources Management, the environment ...

  20. Overlimiting current in a microchannel

    CERN Document Server

    Dydek, E Victoria; Rubinstein, Isaak; Deng, D S; Mani, Ali; Bazant, Martin Z

    2011-01-01

    We revisit the classical problem of diffusion-limited ion transport to a membrane (or electrode) by considering the effects of charged side walls. Using simple mathematical models and numerical simulations, we identify three basic mechanisms for over-limiting current in a microchannel: (i) {\\it surface conduction} carried by excess counterions, which dominates for very thin channels, (ii) convection by {\\it electro-osmotic flow} on the side walls, which dominates for thicker channels and transitions to (iii) {\\it electro-osmotic instability} on the membrane end in very thick channels. These intriguing electrokinetic phenomena may find applications in biological separations, water desalination, and electrochemical energy storage.

  1. Decomposition of residue currents

    OpenAIRE

    Andersson, Mats; Wulcan, Elizabeth

    2007-01-01

    Given a submodule $J\\subset \\mathcal O_0^{\\oplus r}$ and a free resolution of $J$ one can define a certain vector valued residue current whose annihilator is $J$. We make a decomposition of the current with respect to Ass$(J)$ that correspond to a primary decomposition of $J$. As a tool we introduce a class of currents that includes usual residue and principal value currents; in particular these currents admit a certain type of restriction to analytic varieties and more generally to construct...

  2. Inrush Current Control Circuit

    Science.gov (United States)

    Cole, Steven W. (Inventor)

    2002-01-01

    An inrush current control circuit having an input terminal connected to a DC power supply and an output terminal connected to a load capacitor limits the inrush current that charges up the load capacitor during power up of a system. When the DC power supply applies a DC voltage to the input terminal, the inrush current control circuit produces a voltage ramp at the load capacitor instead of an abrupt DC voltage. The voltage ramp results in a constant low level current to charge up the load capacitor, greatly reducing the current drain on the DC power supply.

  3. Electric current arising from unpolarized polyvinyl formal

    Indian Academy of Sciences (India)

    P K Khare; P L Jain; R K Pandey

    2000-10-01

    An appreciable electric current is observed in a system consisting of a polyvinyl formal (PVF) film in a sandwich configuration, in the temperature range 30–110°C. The maximum value of the current during first heating is found to be of the order of 10–10 A and its thermograms exhibit one transition (i.e. current peak) at around 60°C. The position of the current peak in thermal spectrum shifts with the heating rate. A temperature dependence of the open circuit voltage is also observed. The activation energy of the process responsible for the current is determined. The magnitude of the current is more in the case of dissimilar electrode systems. It is proposed that the electric current arising from unpolarized metal–polymer–metal system is a water activated phenomenon, which is influenced by the transitional changes of the polymer.

  4. Current-Induced Membrane Discharge

    DEFF Research Database (Denmark)

    Andersen, Mathias Bækbo; van Soestbergen, M.; Mani, A.;

    2012-01-01

    Possible mechanisms for overlimiting current (OLC) through aqueous ion-exchange membranes (exceeding diffusion limitation) have been debated for half a century. Flows consistent with electro-osmotic instability have recently been observed in microfluidic experiments, but the existing theory...... neglects chemical effects and remains to be quantitatively tested. Here, we show that charge regulation and water self-ionization can lead to OLC by "current-induced membrane discharge'' (CIMD), even in the absence of fluid flow, in ion-exchange membranes much thicker than the local Debye screening length....... Salt depletion leads to a large electric field resulting in a local pH shift within the membrane with the effect that the membrane discharges and loses its ion selectivity. Since salt co-ions, H+ ions, and OH- ions contribute to OLC, CIMD interferes with electrodialysis (salt counterion removal...

  5. Current Situation and Analyses of Integrated Advanced Treatment Techonologies of Water Pollution Control in Rural Areas%农村水污染防治现状及一体化深度处理技术分析

    Institute of Scientific and Technical Information of China (English)

    熊素玉; 王金菊

    2016-01-01

    As the production and living modes in rural areas are changing rapidly,water pollution in rural areas has increased. Treatment of the polluted water in the countryside has been a heated issue,and several targeted techniques for wastewater treatment in rural areas has been developed.Taken features of different techniques into consideration,controlling methods that suit local circumstances,especially the discentralized systems with intergrated advanced techniques for domestic sewage in rural areas,create a win-win situation in environmental,economic and social benefits.%农村生产和生活方式的改变使农村水污染日益严重,农村水环境问题越来越受到社会各界的关注和重视,针对目前农村水环境污染源的现状和特点,已开发了很多各具特点的处理技术,通过对不同技术的分析,因地制宜地选择、完善污染治理技术,尤其是适合分散建设的农村生活污水一体化深度处理技术,可望实现环境效益、经济效益与社会效益多赢。

  6. The Countermeasures and Thinking of Water Conservan-cy Staff's Current Spiritual and Cultural Needs Situation%水利系统职工精神文明需求现状的对策与思考

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      随着物质生活水平的提高,水利职工精神文化需求不断增强。但在实际工作中存在着职工精神文化需求与水利大发展、大建设不相适应的地方,需要我们加强调查研究,从满足职工精神文化需求的视角出发,提出对策与思考。%With the improvement of living standards, the spiritual and cultural needs of water conservancy workers are increasing. On the contrary the spiritual and cultural needs of staff are not adapted to the development and construction of water conservan-cy in practice, so we need to strengthen investigation and study. This paper puts forward the countermeasure and thinking from the perspective of meeting the spiritual and cultural needs of workers.

  7. Water recovery from dew

    OpenAIRE

    Nikolayev, Vadim; Beysens, D; Gioda, A; Milimouk, I; Katiushin, E; Morel, J.-P

    1996-01-01

    International audience; The recovery of clean water from dew has remained a longstanding challenge in many places all around the world. It is currently believed that the ancient Greeks succeeded in recovering atmospheric water vapour on a scale large enough to supply water to the city of Theodosia (presently Feodosia, Crimea, Ukraine). Several attempts were made in the early 20th Cent. to build artificial dew-catching constructions which were subsequently abandoned because of their low yield....

  8. Ocean current measurement techniques

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.

    stream_size 3 stream_content_type text/plain stream_name Trg_Calculat_Water_Depth_Chart_Datum_1991_6.pdf.txt stream_source_info Trg_Calculat_Water_Depth_Chart_Datum_1991_6.pdf.txt Content-Encoding ISO-8859-1 Content-Type text...

  9. 北京市深井人工回灌现状调查与前景分析%Current situation investigation and prospect analysis of artificaial recharge of ground water in Beijing city

    Institute of Scientific and Technical Information of China (English)

    孙颖; 苗礼文

    2001-01-01

    北京市地下水人工回灌研究始于1965年。1981年开始生产性深井人工回灌。由于种种原因,至1999年底实际回灌单位由64个缩减至13个。其间累计回灌量为10734.37×104t。据调查,停灌原因主要有:回灌单位停产、转产、回灌井被占,回灌井阻塞,泵改调频,单位搬迁和改换制冷设备等。本文通过对北京市三十几年来地下水人工回灌工作的总结,分析了人工回灌在近年来发展停滞的原因,并对其在城市可持续发展建设中的节水潜力和今后的发展前景作出了论述。%The study of artificial recharge of ground water in Beijing City started in 1965,and the productive well recharge began in 1981.Due to various reasons,by the end of 1999,the number of artificial recharge units decreased to 13 from 64 at the beginning.The total recharge adds up to 107,343,700 over the period.Investigation result indicates that the main reasons for the stagnation are:Some recharge units stopped production,or switched to other production;Some recharge wells were blocked or taken over for other purposes;Change of location or reconstruction of the refrigeration facilities of the recharge units.This article concluded the artificial recharge of ground water of Beijing City over the past more than thirty years,and analyzed the reason why the development of artifiial recharge has been stagnated in recent years.The water saving potential of artificial recharge during the sustainable development and construction of the city and the prospect of development in the future are expounded.

  10. Electric current locator

    Science.gov (United States)

    King, Paul E [Corvallis, OR; Woodside, Charles Rigel [Corvallis, OR

    2012-02-07

    The disclosure herein provides an apparatus for location of a quantity of current vectors in an electrical device, where the current vector has a known direction and a known relative magnitude to an input current supplied to the electrical device. Mathematical constants used in Biot-Savart superposition equations are determined for the electrical device, the orientation of the apparatus, and relative magnitude of the current vector and the input current, and the apparatus utilizes magnetic field sensors oriented to a sensing plane to provide current vector location based on the solution of the Biot-Savart superposition equations. Description of required orientations between the apparatus and the electrical device are disclosed and various methods of determining the mathematical constants are presented.

  11. Current limiter circuit system

    Energy Technology Data Exchange (ETDEWEB)

    Witcher, Joseph Brandon; Bredemann, Michael V.

    2017-09-05

    An apparatus comprising a steady state sensing circuit, a switching circuit, and a detection circuit. The steady state sensing circuit is connected to a first, a second and a third node. The first node is connected to a first device, the second node is connected to a second device, and the steady state sensing circuit causes a scaled current to flow at the third node. The scaled current is proportional to a voltage difference between the first and second node. The switching circuit limits an amount of current that flows between the first and second device. The detection circuit is connected to the third node and the switching circuit. The detection circuit monitors the scaled current at the third node and controls the switching circuit to limit the amount of the current that flows between the first and second device when the scaled current is greater than a desired level.

  12. Quantization of interface currents

    Energy Technology Data Exchange (ETDEWEB)

    Kotani, Motoko [AIMR, Tohoku University, Sendai (Japan); Schulz-Baldes, Hermann [Department Mathematik, Universität Erlangen-Nürnberg, Erlangen (Germany); Villegas-Blas, Carlos [Instituto de Matematicas, Cuernavaca, UNAM, Cuernavaca (Mexico)

    2014-12-15

    At the interface of two two-dimensional quantum systems, there may exist interface currents similar to edge currents in quantum Hall systems. It is proved that these interface currents are macroscopically quantized by an integer that is given by the difference of the Chern numbers of the two systems. It is also argued that at the interface between two time-reversal invariant systems with half-integer spin, one of which is trivial and the other non-trivial, there are dissipationless spin-polarized interface currents.

  13. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A.; Laird, J.S.; Bardos, R.A.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T.; Sekiguchi, H. [Electrotechnical Laboratory, Tsukuba (Japan).

    1993-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  14. The distribution of Fe in the Antarctic Circumpolar Current

    NARCIS (Netherlands)

    Löscher, B.M.; Baar, H.J.W. de; Jong, J.T.M. de; Veth, C.; Dehairs, F.

    1997-01-01

    The large-scale distributions of dissolved and total Fe in surface and deep waters of the Antarctic Circumpolar Current exhibit strong relationships with hydrography and biological processes. The mean dissolved Fe concentrations are low in surface waters of the Antarctic Circumpolar Current

  15. The distribution of Fe in the Antarctic Circumpolar Current

    NARCIS (Netherlands)

    Löscher, B.M.; Baar, H.J.W. de; Jong, J.T.M. de; Veth, C.; Dehairs, F.

    1997-01-01

    The large-scale distributions of dissolved and total Fe in surface and deep waters of the Antarctic Circumpolar Current exhibit strong relationships with hydrography and biological processes. The mean dissolved Fe concentrations are low in surface waters of the Antarctic Circumpolar Current (0.31–0.

  16. Merging of plasma currents

    NARCIS (Netherlands)

    Bergmans, J.; Schep, T. J.

    2001-01-01

    The merging process of current filaments in a strongly magnetized plasma is described. The evolution is calculated using a contour dynamics method, which accurately tracks piecewise constant distributions of the conserved quantities. In the interaction of two screened currents, both develop dipolar

  17. The Bransfield Gravity Current

    NARCIS (Netherlands)

    Sangrà, P.; Stegner, A.; Hernández-Arencibia, Mónica; Márrero-Díaz, A.; Salinas, C.; Aguiar-González, B.; Henríquez-Pastene, C.H.; Mouriño-Carballido, B.

    2017-01-01

    Using in situ data and laboratory experiments, we show that the circulation of the Bransfield Current (BC) around the South Shetland Islands (SSI) may be characterized in terms of a propagating buoyant gravity current. First, we describe the SSI hydrography and some drifter trajectories, paying spec

  18. Discrete Noether Currents

    CERN Document Server

    Seidl, Gerhart

    2014-01-01

    We present a simple generalization of Noether's theorem for discrete symmetries in relativistic continuum field theories. We calculate explicitly the conserved current for several discrete spacetime and internal symmetries. In addition, we formulate an analogue of the Ward-Takahashi identity for the Noether current associated with a discrete symmetry.

  19. Direct current transformer

    Science.gov (United States)

    Khanna, S. M.; Urban, E. W. (Inventor)

    1979-01-01

    A direct current transformer in which the primary consists of an elongated strip of superconductive material, across the ends of which is direct current potential is described. Parallel and closely spaced to the primary is positioned a transformer secondary consisting of a thin strip of magnetoresistive material.

  20. Electric Current Solves Mazes

    Science.gov (United States)

    Ayrinhac, Simon

    2014-01-01

    We present in this work a demonstration of the maze-solving problem with electricity. Electric current flowing in a maze as a printed circuit produces Joule heating and the right way is instantaneously revealed with infrared thermal imaging. The basic properties of electric current can be discussed in this context, with this challenging question:…

  1. The Bransfield Gravity Current

    NARCIS (Netherlands)

    Sangrà, P.; Stegner, A.; Hernández-Arencibia, Mónica; Márrero-Díaz, A.; Salinas, C.; Aguiar-González, B.; Henríquez-Pastene, C.H.; Mouriño-Carballido, B.

    2017-01-01

    Using in situ data and laboratory experiments, we show that the circulation of the Bransfield Current (BC) around the South Shetland Islands (SSI) may be characterized in terms of a propagating buoyant gravity current. First, we describe the SSI hydrography and some drifter trajectories, paying

  2. Urban water interfaces

    Science.gov (United States)

    Gessner, M. O.; Hinkelmann, R.; Nützmann, G.; Jekel, M.; Singer, G.; Lewandowski, J.; Nehls, T.; Barjenbruch, M.

    2014-06-01

    understanding of aquatic interface processes in urban environments, advance understanding of current and future system behaviour, and promote an integrated urban water management.

  3. Indirect economic impacts in water supplies augmented with desalinated water

    DEFF Research Database (Denmark)

    Rygaard, Martin; Arvin, Erik; Binning, Philip John

    2010-01-01

    softeners. This paper describes potential economic consequences of diluting Copenhagen's drinking water with desalinated water. With a mineral content at 50% of current levels, dental caries and cardiovascular diseases are expected to increase by 51 and 23% respectively. Meanwhile, the number of dish...... going from fresh water based to desalinated water supply. Large uncertainties prevent the current results from being used for or against desalination as an option for Copenhagen's water supply. In the future, more impacts and an uncertainty analysis will be added to the assessment....

  4. Air/Water Purification

    Science.gov (United States)

    1992-01-01

    After 18 years of research into air/water pollution at Stennis Space Center, Dr. B. C. Wolverton formed his own company, Wolverton Environmental Services, Inc., to provide technology and consultation in air and water treatment. Common houseplants are used to absorb potentially harmful materials from bathrooms and kitchens. The plants are fertilized, air is purified, and wastewater is converted to clean water. More than 100 U.S. communities have adopted Wolverton's earlier water hyacinth and artificial marsh applications. Catfish farmers are currently evaluating the artificial marsh technology as a purification system.

  5. Revised analyses of decommissioning for the reference boiling water reactor power station. Effects of current regulatory and other considerations on the financial assurance requirements of the decommissioning rule and on estimates of occupational radiation exposure - main report. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.I.; Bierschbach, M.C.; Konzek, G.J.; McDuffie, P.N.

    1996-07-01

    The NRC staff is in need of updated bases documentation that will assist them in assessing the adequacy of the licensee submittals, from the viewpoint of both the planned actions, including occupational radiation exposure, and the probable costs. The purpose of this reevaluation study is to update the needed bases documentation. This report presents the results of a review and reevaluation of the PNL 1980 decommissioning study of the Washington Public Power Supply System`s Washington Nuclear Plant Two (WNP-2), which is a boiling water reactor (BWR), located at Richland, Washington, including all identifiable factors and cost assumptions which contribute significantly to the total cost of decommissioning the plant for the DECON, SAFSTOR, and ENTOMB decommissioning alternatives. These alternatives now include an initial 5-7 year period during which time the spent fuel is stored in the spent fuel pool prior to beginning major disassembly or extended safe storage of the plant. Included for information (but not part of the license termination cost) is an estimate of the cost to demolish the decontaminated and clean structures on the site and to restore the site to a {open_quotes}green field{close_quotes} condition. This report also includes consideration of the NRC requirement that decontamination and decommissioning activities leading to termination of the nuclear license be completed within 60 years of final reactor shutdown, consideration of packaging and disposal requirements for materials whose radionuclide concentrations exceed the limits for Class C low- level waste (i.e., Greater-Than-Class C), and reflects 1993 costs for labor, materials, transport, and disposal activities. Sensitivity of the total license termination cost to the disposal costs at different low-level radioactive waste disposal sites, to different depths of contaminated concrete surface removal within the facilities, and to different transport distances is also examined.

  6. On current trace problem

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The pricing of electricity trasmission requires determining how much use each generator is making of a transmission line and what is each generator's contribution to the system losses. Such problems cannot be solved by only using Kirchoff's laws. This paper proposes two current decomposition axioms based on which the theories and models are established for the current trace problem. To create an efficient algorithm the graph theory is employed. It is proved that there is no directed circuit in a directed current distribution graph. According to this theorem a very simple and efficient algorithm based on recursive elimination process is suggested. A simple example is used to explain the algorithm.

  7. Turbulent current drive mechanisms

    Science.gov (United States)

    McDevitt, Christopher J.; Tang, Xian-Zhu; Guo, Zehua

    2017-08-01

    Mechanisms through which plasma microturbulence can drive a mean electron plasma current are derived. The efficiency through which these turbulent contributions can drive deviations from neoclassical predictions of the electron current profile is computed by employing a linearized Coulomb collision operator. It is found that a non-diffusive contribution to the electron momentum flux as well as an anomalous electron-ion momentum exchange term provide the most efficient means through which turbulence can modify the mean electron current for the cases considered. Such turbulent contributions appear as an effective EMF within Ohm's law and hence provide an ideal means for driving deviations from neoclassical predictions.

  8. 临湘市中小学饮用水水质现状及介水传染病发病情况分析%Current situation of drinking water and water-borne communicable infection in the primary and middle schools of Linxiang City

    Institute of Scientific and Technical Information of China (English)

    王梅芳; 唐美秀; 刘娟; 彭喜春; 梁绍先; 唐明德

    2011-01-01

    Objective To research the condition of water quality and the incidence of water-bome infection of the primary and middle schools of Linxiang city, and to provide scientific basis for improving drinking water quality and protecting students' physical and mental health.Methods Selecting drinking water samples from 14 primary and middle schools of Linxiang city, the national standard method was used to analyze the quality of the water, and were surveyed by a self-designed questionnaire the incidence of water-bome infection diseases.Results The qualification rate of drinking water was 78.57%, the fecal coliform exceeded the standard in unqualified water.According to the research, in the recent one year, the incidence of enteritis, bacillary dysentery and hepatitis A were 1.80%, 0.19% and 0.06% in the 14 schools.Conclusion Drinking water of the primary and middle schools of Linxiang city is polluted by the fecal coliform.%目的 了解临湘市中小学校饮用水的水质质量及介水传染病的发病情况,为进一步改善饮水质量、保护学生的身心健康提供科学依据.方法 选取临湘市14所中小学校,对生活饮用水按照国家水质分析标准方法进行水质分析,并按照拟定的调查表对学生进行介水传染病的发病情况调查.结果 该市中小学校饮用水合格率仅为78.57%,其中水质不合格主要原因为粪大肠菌群超标;14所学校近1 a饮水学生的肠炎、细菌性痢疾、甲型肝炎的发病率分别为1.80%,O.19%.0.06%.结论 临湘市中小学校的生活饮用水存在粪大肠菌污染隐患.

  9. Prognosis - Cancer Currents Blog

    Science.gov (United States)

    A catalog of posts from NCI’s Cancer Currents blog on research related to cancer prognosis. Includes posts on factors that influence prognosis, prognostic biomarkers, and doctor-patient communications about prognosis.

  10. NOAA NDBC SOS - currents

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NDBC SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have currents data. Because of the nature of SOS requests, requests for...

  11. AUTO FIB Current Status

    Science.gov (United States)

    Parry, I.; Sharples, R. M.

    The current status of the automated fibre positioner, Autofib, is reviewed including the positioning performance and the set-up speed. Future plans to build another Autofib for the 4.2 m William Herschel Telescope are also briefly discussed.

  12. Electrifying Current Events.

    Science.gov (United States)

    Smith, Philip

    1980-01-01

    The author describes how he has adapted the television quiz show format of "College Bowl" to current events study for junior high school students. An insert explains use of the same technique with fourth graders. (SJL)

  13. Geothermal Energy: Current abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Ringe, A.C. (ed.)

    1988-02-01

    This bulletin announces the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. (ACR)

  14. Current Icing Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Current Icing Product (CIP) is an automatically-generated index suitable for depicting areas of potentially hazardous airframe icing. The CIP algorithm combines...

  15. Current Resource Imagery Projects

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — Map showing coverage of current Resource imagery projects. High resolution/large scale Resource imagery is typically acquired for the U.S. Forest Service and other...

  16. Medicare Current Beneficiary Survey

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Characteristics and Perceptions of the Medicare Population Data from the 2010 Medicare Current Beneficiary Survey is a series of source books based on the...

  17. On the formation of current ripples

    DEFF Research Database (Denmark)

    Bartholdy, Jesper; Ernstsen, Verner Brandbyge; Flemming, Burg W.

    2015-01-01

    For grain sizes finer than coarse sand, the first flow-transverse bedforms to develop are current ripples. Although numerous studies have analysed different aspects of bedform morphodynamics, to date no comprehensive physical explanation for the formation of ripples has been given. We offer...... such an explanation based on a virtual boundary layer concept, and present a model predicting ripple height on the basis of grain size, current velocity and water depth. The model contradicts the conventional view of current ripples as bedforms not scaling with flow depth. Furthermore, it confirms the dependence...

  18. Eddy current testing

    Energy Technology Data Exchange (ETDEWEB)

    Song, Sung Jin; Lee, Hyang Beom; Kim, Young Hwan [Soongsil Univ., Seoul (Korea, Republic of); Shin, Young Kil [Kunsan Univ., Gunsan (Korea, Republic of)

    2004-02-15

    Eddy current testing has been widely used for non destructive testing of steam generator tubes. In order to retain reliability in ECT, the following subjects were carried out in this study: numerical modeling and analysis of defects by using BC and RPC probes in SG tube, preparation of absolute coil impedance plane diagram by FEM. Signal interpretation of the eddy current signals obtained from nuclear power plants.

  19. Patterns and Experiences of Current Private Capital Participating in Comprehensive Control of Soil and Water Loss at Small Watershed%新时期民间资本参与小流域水土流失综合治理的模式与经验

    Institute of Scientific and Technical Information of China (English)

    冯伟

    2016-01-01

    Objective] T he objective of this study is to investigate the current participation of private capital in comprehensive control of soil and water loss in small watershed ,to provide references for government policy making .[Methods] Based on the field investigation ,the current situation of private capital participat‐ing in comprehensive control of soil and water loss in small watershed was analyzed and studied .[Results] The characteristics ,models and experiences of the participation of private capital in comprehensive control of soil and water loss in small watershed were summarized .[Conclusion] The private capital has become an important supplement to ecological construction and soil and water conservation in China ,which not only speeds up the control process of soil and water loss , but also improves the management efficiency . To promote this work ,it is necessary to strengthen the relevant work from policy concessions ,construction and management and technical services .%[目的]研究新时期民间资本参与小流域水土流失综合治理情况,为各地政府提供相关决策参考。[方法]在实地调研的基础上,对当前民间资本参与小流域水土流失综合治理情况进行分析研究。[结果]总结分析了民间资本参与小流域水土流失综合治理的特点、模式与经验。[结论]民间资本逐步成为中国水土保持生态建设领域的重要补充,加快了水土流失防治进程,提高了治理效益。要推进这项工作,还需从政策优惠、建设管理、技术服务等方面加强相关工作。

  20. Water Saving for Development

    Science.gov (United States)

    Zacharias, Ierotheos

    2013-04-01

    The project "Water Saving for Development (WaS4D)" is financed by European Territorial Cooperational Programme, Greece-Italy 2007-2013, and aims at developing issues on water saving related to improvement of individual behaviors and implementing innovative actions and facilities in order to harmonize policies and start concrete actions for a sustainable water management, making also people and stakeholders awake to water as a vital resource, strategic for quality of life and territory competitiveness. Drinkable water saving culture & behavior, limited water resources, water supply optimization, water resources and demand management, water e-service & educational e-tools are the key words of WaS4D. In this frame the project objectives are: • Definition of water need for domestic and other than domestic purposes: regional and territorial hydro-balance; • promotion of locally available resources not currently being used - water recycling or reuse and rainwater harvesting; • scientific data implementation into Informative Territorial System and publication of geo-referred maps into the institutional web sites, to share information for water protection; • participated review of the regulatory framework for the promotion of water-efficient devices and practices by means of the definition of Action Plans, with defined targets up to brief (2015) and medium (2020) term; • building up water e-services, front-office for all the water issues in building agricultural, industrial and touristic sectors, to share information, procedures and instruments for the water management; • creation and publication of a user friendly software, a game, to promote sustainability for houses also addressed to young people; • creation of water info point into physical spaces called "Water House" to promote education, training, events and new advisory services to assist professionals involved in water uses and consumers; • implementation of participatory approach & networking for a

  1. Iodine mineral waters

    Directory of Open Access Journals (Sweden)

    Iluta Alexandru

    2011-11-01

    Full Text Available Iodine mineral waters are found especially in sub-Carpathian region, also in regions with Salif deposits. Waters are currently used iodine in drinking cure for chaps and Basedow. Are also indicated in balneology. Iodine water containing at least 1 mg L, there is pure iodine is usually given the nature of other types of mineral waters further: sodium chlorinated water (Bazna (50-70 mg iodine / l, Baile Govora (50 - 70 mg / l, Bălţăteşti (4-5 mg / l, salted Monteoru (30 mg / l, mine water mixed alkaline chlorination, sulphate, which are indicated for crenoterapie (hypo or isotonic to the bathrooms Olăneşti or Călimăneşti-Căciulata.

  2. Water, Water Everywhere, But...

    Science.gov (United States)

    Jacobson, Cliff

    Materials for teaching a unit on water pollution are provided in this teaching package. These materials include: (1) a student reading booklet; (2) a reference booklet listing a variety of popular chemical, biological, and physical tests which can be performed on a local waterway and providing information about the environmental effects and toxic…

  3. Water, Water Everywhere, But...

    Science.gov (United States)

    Jacobson, Cliff

    Materials for teaching a unit on water pollution are provided in this teaching package. These materials include: (1) a student reading booklet; (2) a reference booklet listing a variety of popular chemical, biological, and physical tests which can be performed on a local waterway and providing information about the environmental effects and toxic…

  4. Water microbiology. Bacterial pathogens and water.

    Science.gov (United States)

    Cabral, João P S

    2010-10-01

    Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. In this review a general characterization of the most important bacterial diseases transmitted through water-cholera, typhoid fever and bacillary dysentery-is presented, focusing on the biology and ecology of the causal agents and on the diseases' characteristics and their life cycles in the environment. The importance of pathogenic Escherichia coli strains and emerging pathogens in drinking water-transmitted diseases is also briefly discussed. Microbiological water analysis is mainly based on the concept of fecal indicator bacteria. The main bacteria present in human and animal feces (focusing on their behavior in their hosts and in the environment) and the most important fecal indicator bacteria are presented and discussed (focusing on the advantages and limitations of their use as markers). Important sources of bacterial fecal pollution of environmental waters are also briefly indicated. In the last topic it is discussed which indicators of fecal pollution should be used in current drinking water microbiological analysis. It was concluded that safe drinking water for all is one of the major challenges of the 21st century and that microbiological control of drinking water should be the norm everywhere. Routine basic microbiological analysis of drinking water should be carried out by assaying the presence of Escherichia coli by culture methods. Whenever financial resources are available, fecal coliform determinations should be complemented with the quantification of enterococci. More studies are needed in order to check if ammonia is reliable for a preliminary screening for emergency fecal pollution outbreaks. Financial resources should be devoted to a better understanding of the ecology and behavior of human and animal fecal bacteria in environmental waters.

  5. NASA Water Resources Program

    Science.gov (United States)

    Toll, David L.

    2011-01-01

    projects under five functional themes. I) Streamflow and Flood Forecasting 2) Water Supply and Irrigation (includes evapotranspiration) 3) Drought 4) Water Quality 5) Climate and Water Resources. To maximize this activity NASA Water Resources Program works closely with other government agencies (e.g., the National Oceanic and Atmospheric Administration (NOAA); the U.S. Department of Agriculture (USDA); the U.S. Geological Survey (USGS); the Environmental Protection Agency (EPA), USAID, the Air Force Weather Agency (AFWA)), universities, non-profit national and international organizations, and the private sector. The NASA Water Resources program currently is funding 21 active projects under the functional themes (http://wmp.gsfc.nasa.gov & http://science.nasa.gov/earth-science/applied-sciences/).

  6. On current trace problem

    Institute of Scientific and Technical Information of China (English)

    王锡凡; 王秀丽

    2000-01-01

    The pricing of electricity trasmission requires determining how much use each generator is making of a transmission line and what is each generator’s contribution to the system losses. Such problems cannot be solved by only using Kirchoff’s laws. This paper proposes two current decomposition axioms based on which the theories and models are established for the current trace problem. To create an efficient algorithm the graph theory is employed. It is proved that there is no directed circuit in a directed current distribution graph. According to this theorem a very simple and efficient algorithm based on recursive elimination process is suggested. A simple example is used to explain the algorithm .

  7. Decomposing the Current

    DEFF Research Database (Denmark)

    Hansen, Tim

    The field of molecular electronics have been shown to span a huge range of properties. In an effort to extract the parameters of the system that governs these properties, a number of methods that decomposes the current have been developed. These methods function not just as tools for data...... extraction, but also serves as the foundation upon which to gain insights into the physics that governs the molecular properties. As such, the understanding of the applicability and the development of new methods to decompose the current may be a goal in it self. In this thesis we will explore some...... of these methods, and use the insights from this study to develop new methods. First, we will compare two methods that decompose the current into the transmission from a single conducting level of the molecular device, by extracting level position and broadening. In general we see that the method that relies on I...

  8. Models of current sintering

    Science.gov (United States)

    Angst, Sebastian; Engelke, Lukas; Winterer, Markus; Wolf, Dietrich E.

    2017-06-01

    Densification of (semi-)conducting particle agglomerates with the help of an electrical current is much faster and more energy efficient than traditional thermal sintering or powder compression. Therefore, this method becomes more and more common among experimentalists, engineers, and in industry. The mechanisms at work at the particle scale are highly complex because of the mutual feedback between current and pore structure. This paper extends previous modelling approaches in order to study mixtures of particles of two different materials. In addition to the delivery of Joule heat throughout the sample, especially in current bottlenecks, thermoelectric effects must be taken into account. They lead to segregation or spatial correlations in the particle arrangement. Various model extensions are possible and will be discussed.

  9. Decomposing the Current

    DEFF Research Database (Denmark)

    Hansen, Tim

    The field of molecular electronics have been shown to span a huge range of properties. In an effort to extract the parameters of the system that governs these properties, a number of methods that decomposes the current have been developed. These methods function not just as tools for data...... extraction, but also serves as the foundation upon which to gain insights into the physics that governs the molecular properties. As such, the understanding of the applicability and the development of new methods to decompose the current may be a goal in it self. In this thesis we will explore some...... of these methods, and use the insights from this study to develop new methods. First, we will compare two methods that decompose the current into the transmission from a single conducting level of the molecular device, by extracting level position and broadening. In general we see that the method that relies on I...

  10. Current concepts in osteolysis.

    Science.gov (United States)

    Ollivere, B; Wimhurst, J A; Clark, I M; Donell, S T

    2012-01-01

    The most frequent cause of failure after total hip replacement in all reported arthroplasty registries is peri-prosthetic osteolysis. Osteolysis is an active biological process initiated in response to wear debris. The eventual response to this process is the activation of macrophages and loss of bone. Activation of macrophages initiates a complex biological cascade resulting in the final common pathway of an increase in osteolytic activity. The biological initiators, mechanisms for and regulation of this process are beginning to be understood. This article explores current concepts in the causes of, and underlying biological mechanism resulting in peri-prosthetic osteolysis, reviewing the current basic science and clinical literature surrounding the topic.

  11. Induction motor starting current

    Energy Technology Data Exchange (ETDEWEB)

    Arneaud, J.M.; Langman, R.A. [Tasmania Univ., Hobart, TAS (Australia)

    1995-12-31

    Large errors may occur if leakage path saturation is neglected when reduced-voltage test results are used to predict the direct-on-line starting current of induction motors. The results of applying three existing and two new methods for starting current prediction are compared with test data from 52 motors. A quantitative assessment is made of the probable reduction in error that would be achieved by increasing the number of available sets of reduced-voltage, locked rotor test results or by including slot design data. Guidelines are given for selecting an appropriate predictive method. (author). 4 tabs., 1 fig., 6 refs.

  12. Healthy Water

    Science.gov (United States)

    ... Topics Newsroom, Features, & Announcements CDC at Work: Healthy Water Fast Facts WASH-related Observances Top Causes of Drinking ... Features, & Announcements Training & Education CDC at Work: Healthy Water Policy & Recommendations Fast Facts Index of Water-Related Topics By A- ...

  13. Parasites: Water

    Science.gov (United States)

    ... Tropical Diseases Laboratory Diagnostic Assistance [DPDx] Parasites Home Water Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir Parasites can live in natural water sources. When outdoors, treat your water before drinking ...

  14. Water Safety

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Water Safety KidsHealth > For Parents > Water Safety Print A ... best measure of protection. previous continue Making Kids Water Wise It's important to teach your kids proper ...

  15. Water pollution

    OpenAIRE

    Institute, Marine

    2013-01-01

    Students will learn about what causes water pollution and how to be environmentally aware. *Note: Students should understand the concept of the water cycle before moving onto water pollution (see Lesson Plan “Oceans all Around Us”).

  16. Surfzone currents at Candolim and Miramar beaches of Goa, India: measurements and comparisons

    Digital Repository Service at National Institute of Oceanography (India)

    Yadhunath, E.M.; JayaKumar, S.; Jishad, M.; Gowthaman, R.; Rajasekaran, C.; Pednekar, P.S.

    Measurements in the surfzone current are often carried out using Acoustic Doppler Velocimeters, Electromagnetic current meters, as well as visual observations based on floats A simple approach is used to install an Aanderaa current meter in water...

  17. Water conservation

    CSIR Research Space (South Africa)

    Gibberd, Jeremy T

    2009-02-01

    Full Text Available of their water needs from rainwater harvesting. • Water quality: The quality of water is matched with use. For instance, the best quality water may be used for drinking and cooking and poorer quality water, such as grey water, used for flushing toilets... and irrigation. • Onsite retention: In natural environments vegetation and soil absorb and retain a large proportion of rain water that falls on to it. Green buildings aim to emulate this by ensuring that buildings and sites absorb and retain rain water...

  18. [Acromegaly: current view].

    Science.gov (United States)

    Kršek, Michal

    2015-10-01

    Acromegaly is a rare disorder caused by autonomous oversecretion of growth hormone mostly by pituitary adenoma. Untreated acromegaly leads to significantly increased morbidity and mortality and impaired quality of life. Early diagnosis and treatment is therefore essential for improvement of patients prognosis and management of acromegaly should be concentrated in specialized centres. Present article summarizes current view on diagnosis and treatment of acromegaly.

  19. Impact of phase angle on the hydrodynamic performance of a bi-unit vertical axis tidal current energy water turbine%相位角对双机组立轴水轮机的水动力性能影响

    Institute of Scientific and Technical Information of China (English)

    王凯; 孙科; 张亮; 盛其虎

    2016-01-01

    The impact of phase angles on the hydrodynamic performance of a bi⁃unit two⁃blade vertical axis tidal current energy water turbine were investigated using a CFD numerical simulation method. We analyzed the hydrody⁃namic performance of a water turbine under different starting phase angles and derived the change law for the effi⁃ciency of the water turbine, and the normal and tangential force coefficients of the blades. By analyzing velocity vector drawing and pressure drawing, the change mechanism was also investigated. The results demonstrated that the efficiency of two single⁃unit water turbines was less than that of a single bi⁃unit tidal current energy water tur⁃bine, particularly at middle and high speeds. The overall efficiency of the water turbine at all phase angles was close to or higher than the efficiency at 0 degrees. The efficiency curves of the two units converged when the phase angle was 90 degrees, and at the same time, the bearing force was small because both the force⁃bearing coefficient of the blade and the high pressure area on the blade top were also small. An initial starting phase angle of 90 de⁃grees improved the efficiency of the bi⁃unit water turbine and reduced the bearing force on the blade, allowing the life of the turbine to be extended.%为了研究相位角对双机组两叶片垂直轴潮流能水轮机的水动力性能影响,采用CFD数值模拟方法,计算了不同初始相位角下水轮机水动力性能,得到水轮机的效率、叶片切向力系数及法向力系数的变化规律,并通过速度矢量图和压力图的细节分析,解释变化机理。研究结果表明:双机组潮流能水轮机效率比两个单机组水轮机工作效率高,特别在中高速比时更明显。除0°以外的相位角下水轮机总效率相近且高于0°时的效率。90°相位角时两个机组的效率曲线基本重合,且此时叶片受力系数小,叶尖高压区域也小,从

  20. Water Microbiology. Bacterial Pathogens and Water

    Directory of Open Access Journals (Sweden)

    João P. S. Cabral

    2010-10-01

    Full Text Available Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. In this review a general characterization of the most important bacterial diseases transmitted through water—cholera, typhoid fever and bacillary dysentery—is presented, focusing on the biology and ecology of the causal agents and on the diseases’ characteristics and their life cycles in the environment. The importance of pathogenic Escherichia coli strains and emerging pathogens in drinking water-transmitted diseases is also briefly discussed. Microbiological water analysis is mainly based on the concept of fecal indicator bacteria. The main bacteria present in human and animal feces (focusing on their behavior in their hosts and in the environment and the most important fecal indicator bacteria are presented and discussed (focusing on the advantages and limitations of their use as markers. Important sources of bacterial fecal pollution of environmental waters are also briefly indicated. In the last topic it is discussed which indicators of fecal pollution should be used in current drinking water microbiological analysis. It was concluded that safe drinking water for all is one of the major challenges of the 21st century and that microbiological control of drinking water should be the norm everywhere. Routine basic microbiological analysis of drinking water should be carried out by assaying the presence of Escherichia coli by culture methods. Whenever financial resources are available, fecal coliform determinations should be complemented with the quantification of enterococci. More studies are needed in order to check if ammonia is reliable for a preliminary screening for emergency fecal pollution outbreaks. Financial resources should be devoted to a better understanding of the ecology and behavior of human and animal fecal bacteria in environmental waters.

  1. Water uptake and water supply

    NARCIS (Netherlands)

    Sonneveld, C.; Voogt, W.

    2009-01-01

    The water uptake and the water supply do not directly affect the mineral absorption of plants. However, many connections exist between the management of minerals and water. The most evident of those connections are following

  2. Marijuana: Current concepts

    Directory of Open Access Journals (Sweden)

    Donald eGreydanus

    2013-10-01

    Full Text Available Marijuana (cannabis remains a controversial drug in the 21st century. This paper considers current research on use of Cannabis sativa and its constituents such as the cannabinoids. Topics reviewed include prevalence of cannabis use, other drugs consumed with pot, the endocannabinoid system, use of medicinal marijuana, medical adverse effects of cannabis, and psychiatric adverse effects of cannabis use. Treatment of cannabis withdrawal and dependence is difficult and remains mainly based on psychological therapy; current research on pharmacologic management of problems related to cannabis consumption is also considered. The potential role of specific cannabinoids for medical benefit will be revealed as the 21st century matures. However, potential dangerous adverse effects from smoking marijuana are well known and should be clearly taught to a public often confused by a media-driven, though false message and promise of benign pot consumption.

  3. Marijuana: Current Concepts†

    Science.gov (United States)

    Greydanus, Donald E.; Hawver, Elizabeth K.; Greydanus, Megan M.; Merrick, Joav

    2013-01-01

    Marijuana (cannabis) remains a controversial drug in the twenty-first century. This paper considers current research on use of Cannabis sativa and its constituents such as the cannabinoids. Topics reviewed include prevalence of cannabis (pot) use, other drugs consumed with pot, the endocannabinoid system, use of medicinal marijuana, medical adverse effects of cannabis, and psychiatric adverse effects of cannabis use. Treatment of cannabis withdrawal and dependence is difficult and remains mainly based on psychological therapy; current research on pharmacologic management of problems related to cannabis consumption is also considered. The potential role of specific cannabinoids for medical benefit will be revealed as the twenty-first century matures. However, potential dangerous adverse effects from smoking marijuana are well known and should be clearly taught to a public that is often confused by a media-driven, though false message and promise of benign pot consumption. PMID:24350211

  4. Current management of presbyopia

    Directory of Open Access Journals (Sweden)

    Pandelis A Papadopoulos

    2014-01-01

    Full Text Available Presbyopia is a physiologic inevitability that causes gradual loss of accommodation during the fifth decade of life. The correction of presbyopia and the restoration of accommodation are considered the final frontier of refractive surgery. Different approaches on the cornea, the crystalline lens and the sclera are being pursued to achieve surgical correction of this disability. There are however, a number of limitations and considerations that have prevented widespread acceptance of surgical correction for presbyopia. The quality of vision, optical and visual distortions, regression of effect, complications such as corneal ectasia and haze, anisometropia after monovision correction, impaired distance vision and the invasive nature of the currently techniques have limited the utilization of presbyopia surgery. The purpose of this paper is to provide an update of current procedures available for presbyopia correction and their limitations.

  5. 我国造纸工业废水深度处理的技术现状及其发展趋势%Current Status and Development Trend of Advanced Treatment Technologies for Waste Water of Paper Industry in China

    Institute of Scientific and Technical Information of China (English)

    翟阳

    2011-01-01

    主要介绍了目前我国造纸工业废水深度处理的混凝、吸附、高级氧化、膜分离与膜生物反应器(MBR)工艺、磁混凝沉淀与磁化-仿酶催化缩合工艺、氧化塘、人工湿地等主要技术的现状,并分析了其发展趋势.%Various waster water advanced treatment technologies currently widely used in China' a paper industry including coagulation, Adsorption, advanced oxidation, membrane technology, magnelization-biomimetic enzyme condensation, oxidation pond and constructed wetland and some examples of their application. The development trend of these technologies were discussed.

  6. Current and future photovoltaics

    OpenAIRE

    Boreland, M.B.; Bagnall, D.M.

    2006-01-01

    Photovoltaics, now a billion-dollar industry, is experiencing staggering growth as increased concerns over fuel supply and carbon emissions have encouraged governments and environmentalists to become increasingly prepared to offset the extra cost of solar energy. Three 'generations' of photovoltaics have been envisaged that will take solar power into the mainstream. Photovoltaic production is currently 90% 'first-generation' or '1G' solar cells that rely on expensive bulk multi-crystalline or...

  7. Current Research Activities.

    Science.gov (United States)

    1975-02-01

    Biological oceanography, marine food chain dynamics, carbon cycling in the ocean. Martin, Seelye,Ph.D., Johns Hopkins. Geophysical fluid dynamics...currently under investigation, (Ahmed, Packard) 8. Amylase studies An assay for amylase activity has been adapted to measure zooplankton grazing. This...as a function of available food and of the biomass of copepods, was prescribed by sixteen equations: five, corresponding to copepodite stages (I to V

  8. Lubricated viscous gravity currents

    OpenAIRE

    Kowal, Katarzyna N.; Worster, M. Grae

    2015-01-01

    This is the author accepted manuscript. The final version is available via CUP at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9553100&fileId=S0022112015000300. We present a theoretical and experimental study of viscous gravity currents lubricated by another viscous fluid from below. We use lubrication theory to model both layers as Newtonian fluids spreading under their own weight in two-dimensional and axisymmetric settings over a smooth rigid horizontal surfa...

  9. Clopidogrel Resistance: Current Issues

    Directory of Open Access Journals (Sweden)

    NS Neki

    2016-05-01

    Full Text Available Antiplatelet agents are mainly used in the prevention and management of atherothrombotic complications. Dual antiplatelet therapy, combining aspirin and clopidogrel, is the standard care for patients having acute coronary syndromes or undergoing percutaneous coronary intervention according to the current ACC/AHA and ESC guidelines. But in spite of administration of dual antiplatelet therapy, some patients develop recurrent cardiovascular ischemic events especially stent thrombosis which is a serious clinical problem. Antiplatelet response to clopidogrel varies widely among patients based on ex vivo platelet function measurements. Clopidogrel is an effective inhibitor of platelet activation and aggregation due to its selective and irreversible blockade of the P2Y12 receptor. Patients who display little attenuation of platelet reactivity with clopidogrel therapy are labeled as low or nonresponders or clopidogrel resistant. The mechanism of clopidogrel resistance remains incompletely defined but there are certain clinical, cellular and genetic factors including polymorphisms responsible for therapeutic failure. Currently there is no standardized or widely accepted definition of clopidogrel resistance. The future may soon be realised in the routine measurement of platelet activity in the same way that blood pressure, cholesterol and blood sugar are followed to help guide the therapy, thus improving the care for millions of people. This review focuses on the methods used to identify patients with clopidogrel resistance, the underlying mechanisms, metabolism, clinical significance and current therapeutic strategies to overcome clopidogrel resistance. J Enam Med Col 2016; 6(1: 38-46

  10. Turbulent current drive

    Science.gov (United States)

    Garbet, X.; Esteve, D.; Sarazin, Y.; Dif-Pradalier, G.; Ghendrih, P.; Grandgirard, V.; Latu, G.; Smolyakov, A.

    2014-11-01

    The Ohm's law is modified when turbulent processes are accounted for. Besides an hyper-resistivity, already well known, pinch terms appear in the electron momentum flux. Moreover it appears that turbulence is responsible for a source term in the Ohm's law, called here turbulent current drive. Two terms contribute to this source. The first term is a residual stress in the momentum flux, while the second contribution is an electro-motive force. A non zero average parallel wave number is needed to get a finite source term. Hence a symmetry breaking mechanism must be invoked, as for ion momentum transport. E × B shear flows and turbulence intensity gradients are shown to provide similar contributions. Moreover this source term has to compete with the collision friction term (resistivity). The effect is found to be significant for a large scale turbulence in spite of an unfavorable scaling with the ratio of the electron to ion mass. Turbulent current drive appears to be a weak effect in the plasma core, but could be substantial in the plasma edge where it may produce up to 10 % of the local current density.

  11. Pulse current enhanced electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Sun, Tian R.; Ottosen, Lisbeth M.; Jensen, Pernille E.

    2012-01-01

    Energy consumption is an important factor influencing the cost of electrodialytic soil remediation (EDR). It has been indicated that the pulse current (in low frequency range) could decrease the energy consumption during EDR. This work is focused on the comparison of energy saving effect...... at different pulse frequencies. Based on the restoration of equilibrium, the relaxation process of the soil-water system was investigated by chronopotentiometric analysis to find the optimal relaxation time for energy saving. Results showed that the pulse current decreased the energy consumption with different...... extent depending on the pulse frequency. The experiment with the frequency of 16 cycles per day showed the best restoration of equilibrium and lowest energy consumption. The energy consumption per removed heavy metals was lower in pulse current experiments than constant current and increased...

  12. A site-specific agricultural water requirement and footprint estimator (SPARE:WATER 1.0) for irrigation agriculture

    OpenAIRE

    S. Multsch; Al-Rumaikhani, Y. A.; H.-G. Frede; L. Breuer

    2013-01-01

    The water footprint accounting method addresses the quantification of water consumption in agriculture, whereby three types of water to grow crops are considered, namely green water (consumed rainfall), blue water (irrigation from surface or groundwater) and grey water (water needed to dilute pollutants). Most of current water footprint assessments focus on global to continental scale. We therefore developed the spatial decision support system SPARE:WATER that allows to quantify green, blu...

  13. Turbidity Current Head Mixing

    Science.gov (United States)

    Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

    2010-05-01

    A laboratory experimental set - up for studying the behaviour of sediment in presence of a turbulent field with zero mean flow is compared with the behaviour of turbidity currents [1] . Particular interest is shown on the initiation of sediment motion and in the sediment lift - off. The behaviour of the turbidity current in a flat ground is compared with the zero mean flow oscilating grid generated turbulence as when wave flow lifts off suspended sediments [2,3]. Some examples of the results obtained with this set-up relating the height of the head of the turbidity current to the equilibrium level of stirred lutoclines are shown. A turbulent velocity u' lower than that estimated by the Shield diagram is required to start sediment motion. The minimum u' required to start sediment lift - off, is a function of sediment size, cohesivity and resting time. The lutocline height depends on u', and the vorticity at the lutocline seems constant for a fixed sediment size [1,3]. Combining grid stirring and turbidty current head shapes analyzed by means of advanced image analysis, sediment vertical fluxes and settling speeds can be measured [4,5]. [1] D. Hernandez Turbulent structure of turbidity currents and sediment transport Ms Thesis ETSECCPB, UPC. Barcelona 2009. [2] A. Sánchez-Arcilla; A. Rodríguez; J.C. Santás; J.M. Redondo; V. Gracia; R. K'Osyan; S. Kuznetsov; C. Mösso. Delta'96 Surf-zone and nearshore measurements at the Ebro Delta. A: International Conference on Coastal Research through large Scale Experiments (Coastal Dynamics '97). University of Plymouth, 1997, p. 186-187. [3] P. Medina, M. A. Sánchez and J. M. Redondo. Grid stirred turbulence: applications to the initiation of sediment motion and lift-off studies Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere. 26, Issue 4, 2001, Pages 299-304 [4] M.O. Bezerra, M. Diez, C. Medeiros, A. Rodriguez, E. Bahia., A. Sanchez-Arcilla and J.M. Redondo. Study on the influence of waves on

  14. Impressed current cathodic protection of deep water structures

    Digital Repository Service at National Institute of Oceanography (India)

    Venkatesan, R.

    stream_size 5 stream_content_type text/plain stream_name Proc_Semin_Ocean_Ind_Realities_Expect_1994_56.pdf.txt stream_source_info Proc_Semin_Ocean_Ind_Realities_Expect_1994_56.pdf.txt Content-Encoding ISO-8859-1 Content-Type text...

  15. Tidal currents assessment in the Tagus estuary

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, A. (CEHIDRO, Instituto Superior Tecnico, Av. Rovisco Pais, Lisboa, (PT)); Trigo Teixeira, A. (Department of Civil Engineering and Architecture, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, Lisboa (PT))

    2007-07-01

    The authors present in this paper the results of an initial assessment of the potential of tidal currents to generate energy in the Tagus estuary. The work is divided into three phases. The first phase comprises the setting up and calibration of a detailed finite element model for the estuary starting in the ocean boundary. The model was calibrated and verified using water levels and current velocities for several measuring stations within the estuary. The measuring campaign took place in 1987 and was performed by Instituto Hidrografico of the Portuguese Navy. The records are of good quality and cover a period of spring and neap tides. The model give clear indication about the flow pattern within the estuary showing the places were high current velocities are likely to occur. Calculation of the tidal power on selected locations was made. The second phase consisted on the study of the requirements of tidal turbines in terms of site conditions: mainly the minimum water depth and current velocity required for installation. In addition a review was made to understand the development of tidal turbine technology. Three types of turbines were selected as having potential for the site, which usually are associated with moderate current velocity. The third and final phase was the study of the estuary 'map-use' through the construction of a GIS system that allows the identification of locations of potential conflict.

  16. Stochastic longshore current dynamics

    Science.gov (United States)

    Restrepo, Juan M.; Venkataramani, Shankar

    2016-12-01

    We develop a stochastic parametrization, based on a 'simple' deterministic model for the dynamics of steady longshore currents, that produces ensembles that are statistically consistent with field observations of these currents. Unlike deterministic models, stochastic parameterization incorporates randomness and hence can only match the observations in a statistical sense. Unlike statistical emulators, in which the model is tuned to the statistical structure of the observation, stochastic parametrization are not directly tuned to match the statistics of the observations. Rather, stochastic parameterization combines deterministic, i.e physics based models with stochastic models for the "missing physics" to create hybrid models, that are stochastic, but yet can be used for making predictions, especially in the context of data assimilation. We introduce a novel measure of the utility of stochastic models of complex processes, that we call consistency of sensitivity. A model with poor consistency of sensitivity requires a great deal of tuning of parameters and has a very narrow range of realistic parameters leading to outcomes consistent with a reasonable spectrum of physical outcomes. We apply this metric to our stochastic parametrization and show that, the loss of certainty inherent in model due to its stochastic nature is offset by the model's resulting consistency of sensitivity. In particular, the stochastic model still retains the forward sensitivity of the deterministic model and hence respects important structural/physical constraints, yet has a broader range of parameters capable of producing outcomes consistent with the field data used in evaluating the model. This leads to an expanded range of model applicability. We show, in the context of data assimilation, the stochastic parametrization of longshore currents achieves good results in capturing the statistics of observation that were not used in tuning the model.

  17. The Weak Neutral Current

    CERN Document Server

    Erler, Jens

    2013-01-01

    This is a review of electroweak precision physics with particular emphasis on low-energy precision measurements in the neutral current sector of the electroweak theory and includes future experimental prospects and the theoretical challenges one faces to interpret these observables. Within the minimal Standard Model they serve as determinations of the weak mixing angle which are competitive with and complementary to those obtained near the Z-resonance. In the context of new physics beyond the Standard Model these measurements are crucial to discriminate between models and to reduce the allowed parameter space within a given model. We illustrate this for the minimal supersymmetric Standard Model with or without R-parity.

  18. ONLINE PUBLISHING CURRENT SCENARIO

    Directory of Open Access Journals (Sweden)

    Balasubramanian Thiagarajan

    2012-12-01

    Full Text Available This article attempts to unravel the current scenario in online publishing. Advent of internet has brought with it tremendous changes in the publishing industry. What was hither to an industry dominated by publisher has been thrown open to one and sundry. Online publishing has brought with it a reach which was hitherto never been imagined. In the normal course it would take at least a year to publish a manuscript. Online publishing has managed to bring this time down to a few weeks / at most a month. This article attempts to discusses the positives and perils of online publishing scenario.

  19. SBC Dark Current Measurement

    Science.gov (United States)

    Ogaz, Sara

    2013-10-01

    This takes a series of SBC dark measurements over a continuous period of about 6 hours {4 orbits}. The aim is to collect dark images during an extended SBC on-time. Earlier measurements indicate that the dark current increases with SBC on-time and may also be increasing with overall SBC use. The 6-hour time matches the longest time used by any observer. As with all SBC observations this needs continuous SAA free time.This program is executed once per cycle. The last exposures were taken in Mar 2013 under Program 13161.

  20. Current Conveyor Equivalent Circuits

    Directory of Open Access Journals (Sweden)

    Tejmal S. Rathore

    2012-02-01

    Full Text Available An equivalence between a class of (current conveyor CC II+ and CC II- circuits is established. CC IIequivalent circuit uses one extra element. However, under certain condition, the extra element can be eliminated. As an illustration of the application of this equivalence, minimal first and second order all-pass filters are derived. Incertain cases, it is possible to compensate the effect of the input resistor of CC at port X. At the end, an open problem of realizing an Nth order (N > 2 minimal all-pass filter is stated.