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Sample records for high water discharge

  1. High Conductivity Water Treatment Using Water Surface Discharge with Nonmetallic Electrodes

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoping; Zhang, Xingwang; Lei, Lecheng

    2013-06-01

    Although electrohydraulic discharge is effective for wastewater treatment, its application is restricted by water conductivity and limited to the treatment of low conductivity water. For high conductivity water treatment, water-surface discharge is the preferred choice. However, the metallic electrodes are easily corroded because of the high temperature and strong oxidative environment caused by gas phase discharge and the electrochemical reaction in water. As a result, the efficiency of the water treatment might be affected and the service life of the reactor might be shortened. In order to avoid the corrosion problem, nonmetallic electrode water-surface discharge is introduced into high conductivity water treatment in the present study. Carbon-felt and water were used as the high voltage electrode and ground electrode, respectively. A comparison of the electrical and chemical characteristics showed that nonmetallic electrode discharge maintained the discharge characteristics and enhanced the energy efficiency, and furthermore, the corrosion of metal electrodes was avoided.

  2. Flooding in Myanmar: joint occurrence of high discharges and high sea water levels?

    NASA Astrophysics Data System (ADS)

    Bouaziz, Laurène; Sperna Weiland, Frederiek; Vatvani, Deepak; Diermanse, Ferdinand

    2016-04-01

    In the summer of 2015 serious flooding occurred in Myanmar when cyclone Komen made landfall in Bangladesh, bringing strong winds and heavy rains to Myanmar. The cyclone struck the country during the monsoon season and resulted in widespread flooding, temporarily displacing over 1.6 million people. It was hypothesized that there could be a relation between occurrences of storm surges and extreme discharges in Myanmar. Comparable studies have shown that dependence between storm surge at Hoek van Holland in the Netherlands and high river discharges of the Rhine at Lobith exist with a lag of 6 days (Klerk et. al, 2015). The processes generating high discharges in the Ayeyarwady river and storm surges along the Myanmar coast were analyzed using global precipitation data (EU FP7 eartH2Observe), a distributed wflow-sbm hydrological model of the Ayeyarwady and a global storm surge model. About 15 historical tropical storms and hurricanes affecting Myanmar since 1992 were analyzed in terms of rainfall distribution over the country, discharged river flow volumes and storm surge extent and magnitude. All storms except for Komen in 2015 occurred between October and May, which does not coincide with the monsoon season (mainly June, July and August). The intensities and the paths of the 15 studied cyclones varied considerably and largely affected the spatial extent and the magnitude of storm surges. The study showed that high Ayeyarwady river flows and high surges generally do not coincide for the following reasons: the large scale of the river basin, the estimated one week travel time of water from the upstream catchment to the mouth, the occurrence of the majority of historical storms outside the monsoon season and the (relatively) limited spatial extent of a storm surge (at the scale of Myanmar). While the applied method is deemed successful for the identification of joint probabilities of surges and river discharges, this study indicates that such analyses are more relevant

  3. High resolution synoptic salinity mapping to identify groundwater--surface water discharges in lowland rivers.

    PubMed

    Pai, Henry; Villamizar, Sandra R; Harmon, Thomas C

    2015-04-21

    Quantifying distributed lateral groundwater contributions to surface water (GW-SW discharges) is a key aspect of tracking nonpoint-source pollution (NPSP) within a watershed. In this study, we characterized distributed GW-SW discharges and associated salt loading using elevated GW specific conductance (SC) as a tracer along a 38 km reach of the Lower Merced River in Central California. High resolution longitudinal surveys for multiple flows (1.3-150 m(3) s(-1)) revealed river SC gradients that mainly decreased with increasing flow, suggesting a dilution effect and/or reduced GW-SW discharges due to hydraulic gradient reductions. However, exceptions occurred (gradients increasing with increasing flow), pointing to complex spatiotemporal influences on GW-SW dynamics. The surveys revealed detailed variability in salinity gradients, from which we estimated distributed GW-SW discharge and salt loading using a simple mixing model. Modeled cumulative GW discharges for two surveys unaffected by ungauged SW discharges were comparable in magnitude to differential gauging-based discharge estimates and prior GW-SW studies along the same river reach. Ungauged lateral inlets and sparse GW data limited the study, and argue for enhancing monitoring efforts. Our approach provides a rapid and economical method for characterizing NPSP for gaining rivers in the context of integrated watershed modeling and management. PMID:25837571

  4. Environmental and biotechnological applications of high-voltage pulsed discharges in water

    NASA Astrophysics Data System (ADS)

    Sato, Masayuki

    2008-05-01

    A high-voltage pulse has wide application in fields such as chemistry, physics and biology and their combinations. The high-voltage pulse forms two kinds of physical processes in water, namely (a) a pulsed electric field (PEF) in the parallel electrode configuration and (b) plasma generation by a pulsed discharge in the water phase with a concentrated electric field. The PEF can be used for inactivation of bacteria in liquid foods as a non-thermal process, and the underwater plasma is applicable not only for the decomposition of organic materials in water but also for biological treatment of wastewater. These discharge states are controlled mainly by the applied pulse voltage and the electrode shape. Some examples of environmental and biotechnological applications of a high-voltage pulse are reviewed.

  5. High-Resolution Glacial Discharge Records From Deep-Water Tidal Rhythmites in an Alaskan Fjord

    NASA Astrophysics Data System (ADS)

    Jackolski, C. L.; Cowan, E. A.; Jaeger, J. M.; Powell, R. D.

    2006-12-01

    In this study we have compiled and analyzed two high-resolution records of deep-water tidal rhythmites derived from glacial discharges. The rhythmites contain an average of 1 cm of sediment thickness per week during the melt-season. Two sediment cores over 17-m-long were collected from Muir Inlet, Glacier Bay National Park, Southeast Alaska, aboard the R/V Maurice Ewing in 2004 (EW0408). One core (core 60JC) was collected just north of the mouth of Wachusett Inlet. The other (core 62JC) was collected 3.8 km due north of 60JC in a separate basin more proximal to Muir and McBride Glaciers. In Glacier Bay, glacial retreat since the Little Ice Age Maximum is well constrained by historical mapping of glacial temini, and local climate records exist as well. The next step after establishing glacial discharge records is to test hypotheses relating glacial discharge to temperature and rainfall. The cores were subsampled with ODP-style u-channels and scanned for magnetic susceptibility and bulk density. X-radiographs of u-channels were collected to observe small-scale (42 microns/pixel) density differences between silt and mud laminae. Spring-neap tidal packages, representing 2-week periods during summer, are visible because of closely-spaced bounding silt laminae. Seasonality is marked by winter gravelly mud (diamicton) beds and/or spring plankton blooms. Spring-neap packages and seasonal markers were considered jointly in order to construct two mostly continuous records of spring-neap packages and melt- season deposits in each core. Secondarily, melt-season duration, which we define as the number of spring- neap packages occurring in a melt-season, was determined. We found that core 60JC extends back 83 years. 75 of those years were identified as having complete, contiguous melt-season deposits that are, on average, 17 cm thick and contain 8.3 spring-neap packages. Core 62JC extends back 62 years. 57 of those years were identified as having complete, contiguous melt

  6. Impacts of a high-discharge submarine sewage outfall on water quality in the coastal zone of Salvador (Bahia, Brazil).

    PubMed

    Roth, F; Lessa, G C; Wild, C; Kikuchi, R K P; Naumann, M S

    2016-05-15

    Carbon and nitrogen stable isotopic signatures of suspended particulate organic matter and seawater biological oxygen demand (BOD) were measured along a coastal transect during summer 2015 to investigate pollution impacts of a high-discharge submarine sewage outfall close to Salvador, Brazil. Impacts of untreated sewage discharge were evident at the outfall site by depleted δ(13)Corg and δ(15)N signatures and 4-fold increased BOD rates. Pollution effects of a sewage plume were detectable for more than 6km downstream from the outfall site, as seasonal wind- and tide-driven shelf hydrodynamics facilitated its advective transport into near-shore waters. There, sewage pollution was detectable at recreational beaches by depleted stable isotope signatures and elevated BOD rates at high tides, suggesting high bacterial activity and increased infection risk by human pathogens. These findings indicate the urgent necessity for appropriate wastewater treatment in Salvador to achieve acceptable standards for released effluents and coastal zone water quality. PMID:27038882

  7. Single-step process for the deposition of high water contact angle and high water sliding angle surfaces by atmospheric pressure dielectric barrier discharge.

    PubMed

    Boscher, Nicolas D; Duday, David; Verdier, Stéphane; Choquet, Patrick

    2013-02-01

    Fluorine-free surfaces with high water contact angle (WCA) and high adhesion force to water are prepared by the atmospheric pressure dielectric barrier discharge (AP-DBD) of hexamethyldisiloxane on cold rolled aluminum foil. Water droplets, which remained on the plasma-polymerized hexamethyldisiloxane (ppHMDSO) surface with contact angle of 155°, do not slide even when the surface is tilted vertically or turned upside down. Scanning electron microscopy, atomic force microscopy and confocal microscopy highlight the importance of the dual-scale roughness of the ppHMDSO surface. The "sticky" high WCA property is achieved only when the nanometer scale particles generated during the AP-DBD process are present at the surface of the film and combine to the micrometer scale rolling lines of the aluminum substrate. PMID:23339545

  8. Water purification by electrical discharges

    NASA Astrophysics Data System (ADS)

    Arif Malik, Muhammad; Ghaffar, Abdul; Akbar Malik, Salman

    2001-02-01

    There is a continuing need for the development of effective, cheap and environmentally friendly processes for the disinfection and degradation of organic pollutants from water. Ozonation processes are now replacing conventional chlorination processes because ozone is a stronger oxidizing agent and a more effective disinfectant without any side effects. However, the fact that the cost of ozonation processes is higher than chlorination processes is their main disadvantage. In this paper recent developments targeted to make ozonation processes cheaper by improving the efficiency of ozone generation, for example, by incorporation of catalytic packing in the ozone generator, better dispersion of ozone in water and faster conversion of dissolved ozone to free radicals are described. The synthesis of ozone in electrical discharges is discussed. Furthermore, the generation and plasma chemical reactions of several chemically active species, such as H2O2, Obullet, OHbullet, HO2bullet, O3*, N2*, e-, O2-, O-, O2+, etc, which are produced in the electrical discharges are described. Most of these species are stronger oxidizers than ozone. Therefore, water treatment by direct electrical discharges may provide a means to utilize these species in addition to ozone. Much research and development activity has been devoted to achieve these targets in the recent past. An overview of these techniques and important developments that have taken place in this area are discussed. In particular, pulsed corona discharge, dielectric barrier discharge and contact glow discharge electrolysis techniques are being studied for the purpose of cleaning water. The units based on electrical discharges in water or close to the water level are being tested at industrial-scale water treatment plants.}

  9. START High Performance Discharges

    NASA Astrophysics Data System (ADS)

    Gates, D. A.

    1997-11-01

    Improvements to START (Small Tight Aspect Ratio Tokamak), the first spherical tokamak in the world to achieve high plasma temperature with both a significant pulse length and confinement time, have been ongoing since 1991. Recent modifications include: expansion of the existing capacitor banks allowing plasma currents as high as 300kA, an increase in the available neutral beam heating power ( ~ 500kW), and improvements to the vacuum system. These improvements have led to the achievement of the world record plasma β (≡ 2μ_0 /B^2) of ~ 30% in a tokamak. The normalised β ( βN ≡ β aB/I_p) reached 4.5 with q_95 = 2.3. Properties of the reconstructed equilibrium will be discussed in detail. The theoretical limit to β is higher in a spherical tokamak than in a conventional machine, due to the higher values of normalised current (IN ≡ I_p/aB) achievable at low aspect ratio. The record β was achieved with IN ~ 8 while conventional tokamaks are limited to IN ~ 3, or less. Calculations of the ideal MHD stability of the record discharge indicate high β low-n kink modes are stable, but that the entire profile is at or near marginal stability for high-n ballooning modes. The phenomenology of the events leading up to the plasma termination is discussed. An important aspect of the START program is to explore the physics of neutral beam absorption at low aspect ratio. A passive neutral particle analyser has been used to study the temporal and spatial dependence of the fast hydrogen beam ions. These measurements have been used in conjunction with a single particle orbit code to estimate the fast ion losses due to collisions with slow neutrals from the plasma edge. Numerical analysis of neutral beam power deposition profiles are compared with the data from an instrumented beam stop. The global energy confinement time τE in beam heated discharges on START is similar to that obtained in Ohmic discharges, even though the input power has roughly doubled over the Ohmic case

  10. Discharge and water chemistry of High Arctic rivers in NW Greenland (76° N, 68° W)

    NASA Astrophysics Data System (ADS)

    Hagedorn, B.; Sletten, R. S.; Vigna, A. C.; Hallet, B.

    2004-12-01

    The volume, temperature, and quality of freshwater runoff from high latitude areas ultimately affect sensitive components of polar oceans, including water stratification, nutrient cycling, and formation of deepwater currents. Freshwater is conveyed from Greenland to the ocean from a multitude of medium-sized rivers for which little is known about discharge and water characteristics. River runoff together with microclimate and soil processes were recorded in a typical high Arctic area in NW Greenland where complete climate records from pre-1978 to the present indicate increases in mean annual air temperature from -12.0° C to -10.7° C and precipitation from 65 mm to 120 mm water equivalent between 1993 and 2002. The study will improve understanding of the interaction between climate, landscape processes, and river runoff. The study site extends from the western edge of the Greenland Ice Sheet to Baffin Bay; it covers an area ranging between 10-20 km E-W and 10-15 km N-S, and the elevations reach 700 m. It is a typical high Arctic environment with sparse vegetation and pervasive active patterned ground. Most of the area is covered by glacial drift that resembles the underlying sedimentary and igneous Archean and Proterozoic bedrock. To address how seasonal weather patterns and landscape processes affect runoff and water quality, as well as to examine weathering and carbon budgets in the drainage, we monitor water discharge and suspended load, water temperature, water chemistry (pH, dissolved ions, dissolved organic and inorganic carbon) of three rivers. Two of these rivers originate as melt water runoff from the Greenland Ice Sheet. The third stream is fed by local snowmelt and summer rain events. In addition, climate data along with soil moisture and temperature are recorded with automated stations at two locations. The potential sources of river water are thawing permafrost, local snowmelt, rain, and melting of glacial ice that all have distinct isotopic

  11. Discharges in Water and Applications to Wasted Water Treatment

    NASA Astrophysics Data System (ADS)

    Yamabe, Chobei; Yamashita, Takanori; Ihara, Satoshi

    Recently the electrical discharge in water has been used for the water treatment. In this study, various shape of electrodes were examined to observe and measure the electrical discharge phenomena in water. Both the Marx generator and the pulsed power generator were used to generate the discharge in water. The oscillation on the waveforms of both applied voltage and discharge current was observed using the pulsed power generator whose peak applied voltage was about 80-120 kV and its discharge repetition rate was about one pulse per thirty seconds although it wasn't observed on the waveforms in the practical use of the high voltage generator (peak applied voltage was about 30-40 kV) with high repetition rate of discharge (20-300 pulses per second). Bubbles were introduced into the discharge region of main electrode using the ejector and the generation of hydroxyl radicals (OH) was confirmed by the measurement of emission spectrum of discharge in water and the intensity of OH radicals increased with the ratio of G/L (where, G is gas flow rate and L is water flow rate). The hydrogen peroxide (H2O2) was also measured and this reactor system was applied for the de-color of water.

  12. Estimating ground water discharge by hydrograph separation.

    PubMed

    Hannula, Steven R; Esposito, Kenneth J; Chermak, John A; Runnells, Donald D; Keith, David C; Hall, Larry E

    2003-01-01

    Iron Mountain is located in the West Shasta Mining District in California. An investigation of the generation of acid rock drainage and metals loading to Boulder Creek at Iron Mountain was conducted. As part of that investigation, a hydrograph separation technique was used to determine the contribution of ground water to total flow in Boulder Creek. During high-flow storm events in the winter months, peak flow in Boulder Creek can exceed 22.7 m3/sec, and comprises surface runoff, interflow, and ground water discharge. A hydrograph separation technique was used to estimate ground water discharge into Boulder Creek during high-flow conditions. Total ground water discharge to the creek approaches 0.31 m3/sec during the high-flow season. The hydrograph separation technique combined with an extensive field data set provided reasonable estimates of ground water discharge. These estimates are useful for other investigations, such as determining a corresponding metals load from the metal-rich ground water found at Iron Mountain and thus contributing to remedial alternatives. PMID:12772830

  13. Stretched arc discharge in produced water.

    PubMed

    Cho, Y I; Wright, K C; Kim, H S; Cho, D J; Rabinovich, A; Fridman, A

    2015-01-01

    The objective of the present study was to investigate the feasibility of stretching an arc discharge in produced water to increase the volume of produced water treated by plasma. Produced water is the wastewater generated by hydraulic fracturing of shale during the production phase in shale-oil or shale-gas exploration. The electric conductivity of produced water is in the range of 50-200 mS/cm, which provides both a challenge and opportunity for the application of plasmas. Stretching of an arc discharge in produced water was accomplished using a ground electrode and two high-voltage electrodes: one positioned close to the ground electrode and the other positioned farther away from the ground. The benefit of stretching the arc is that the contact between the arc and water is significantly increased, resulting in more efficient plasma treatment in both performance and energy cost. PMID:25638080

  14. Stretched arc discharge in produced water

    NASA Astrophysics Data System (ADS)

    Cho, Y. I.; Wright, K. C.; Kim, H. S.; Cho, D. J.; Rabinovich, A.; Fridman, A.

    2015-01-01

    The objective of the present study was to investigate the feasibility of stretching an arc discharge in produced water to increase the volume of produced water treated by plasma. Produced water is the wastewater generated by hydraulic fracturing of shale during the production phase in shale-oil or shale-gas exploration. The electric conductivity of produced water is in the range of 50-200 mS/cm, which provides both a challenge and opportunity for the application of plasmas. Stretching of an arc discharge in produced water was accomplished using a ground electrode and two high-voltage electrodes: one positioned close to the ground electrode and the other positioned farther away from the ground. The benefit of stretching the arc is that the contact between the arc and water is significantly increased, resulting in more efficient plasma treatment in both performance and energy cost.

  15. High-resolution water column survey to identify active sublacustrine hydrothermal discharge zones within Lake Rotomahana, North Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Walker, Sharon L.; de Ronde, Cornel E. J.; Fornari, Daniel; Tivey, Maurice A.; Stucker, Valerie K.

    2016-03-01

    Autonomous underwater vehicles were used to conduct a high-resolution water column survey of Lake Rotomahana using temperature, pH, turbidity, and oxidation-reduction potential (ORP) to identify active hydrothermal discharge zones within the lake. Five areas with active sublacustrine venting were identified: (1) the area of the historic Pink Terraces; (2) adjacent to the western shoreline subaerial "Steaming Cliffs," boiling springs and geyser; (3) along the northern shoreline to the east of the Pink Terrace site; (4) the newly discovered Patiti hydrothermal system along the south margin of the 1886 Tarawera eruption rift zone; and (5) a location in the east basin (northeast of Patiti Island). The Pink Terrace hydrothermal system was active prior to the 1886 eruption of Mount Tarawera, but venting along the western shoreline, in the east basin, and the Patiti hydrothermal system appear to have been initiated in the aftermath of the eruption, similar to Waimangu Valley to the southwest. Different combinations of turbidity, pH anomalies (both positive and negative), and ORP responses suggest vent fluid compositions vary over short distances within the lake. The seasonal period of stratification limits vertical transport of heat to the surface layer and the hypolimnion temperature of Lake Rotomahana consequently increases with an average warming rate of ~ 0.010 °C/day due to both convective hydrothermal discharge and conductive geothermal heating. A sudden temperature increase occurred during our 2011 survey and was likely the response to an earthquake swarm just 11 days prior.

  16. Surface water discharges from onshore stripper wells.

    SciTech Connect

    Veil, J. A.

    1998-01-16

    Under current US Environmental Protection Agency (EPA) rules, small onshore oil producers are allowed to discharge produced water to surface waters with approval from state agencies; but small onshore gas producers, however, are prohibited from discharging produced water to surface waters. The purpose of this report is to identify those states that allow surface water discharges from small onshore oil operations and to summarize the types of permitting controls they use. It is intended that the findings of this report will serve as a rationale to encourage the EPA to revise its rules and to remove the prohibition on surface water discharges from small gas operations.

  17. Non-storm water discharges technical report

    SciTech Connect

    Mathews, S.

    1994-07-01

    Lawrence Livermore National Laboratory (LLNL) submitted a Notice of Intent to the California State Water Resources Control Board (hereafter State Board) to discharge storm water associated with industrial activities under the California General Industrial Activity Storm Water National Pollutant Elimination System Discharge Permit (hereafter General Permit). As required by the General Permit, LLNL provided initial notification of non-storm water discharges to the Central Valley Regional Water Quality Control Board (hereafter Regional Board) on October 2, 1992. Additional findings and progress towards corrective actions were reported in subsequent annual monitoring reports. LLNL was granted until March 27, 1995, three years from the Notice of Intent submission date, to eliminate or permit the non-storm water discharges. On May 20, 1994, the Regional Board issued Waste Discharge Requirements (WDR Board Order No. 94-131, NPDES No. CA0081396) to LLNL for discharges of non-contact cooling tower wastewater and storm water related to industrial activities. As a result of the issuance of WDR 94-131, LLNL rescinded its coverage under the General Permit. WDR 94-131 allowed continued non-storm water discharges and requested a technical report describing the discharges LLNL seeks to permit. For the described discharges, LLNL anticipates the Regional Board will either waive Waste Discharge Requirements as allowed for in The Water Quality Control Plan for the California Regional Water Quality Control Board, Central Valley Region (hereafter Basin Plan) or amend Board Order 94-131 as appropriate.

  18. Effect of fine bubbles on electric discharge in water

    NASA Astrophysics Data System (ADS)

    Hayashi, Yui; Takada, Noriharu; Kanda, Hideki; Goto, Motonobu

    2015-10-01

    Ar or O2 fine bubbles of diameter  <80 μm were introduced in water and a pulsed discharge plasma was generated between cylinder electrodes in water. Fine bubbles in water affected discharge ignition and caused low inception voltage and suppression of rising temperature. The contamination from electrodes was suppressed in the case of fine bubbles addition because fine bubbles assisted plasma generation. In addition, discharge with fine bubbles enhanced plasma emission with high electron density compared to the no-bubbling case. Discharge with fine bubbles at low-pH conditions generated intense plasma emission compared to neutral and high-pH conditions owing to the electric charge of the fine bubbles.

  19. Properties of water surface discharge at different pulse repetition rates

    NASA Astrophysics Data System (ADS)

    Ruma, Hosseini, S. H. R.; Yoshihara, K.; Akiyama, M.; Sakugawa, T.; Lukeš, P.; Akiyama, H.

    2014-09-01

    The properties of water surface discharge plasma for variety of pulse repetition rates are investigated. A magnetic pulse compression (MPC) pulsed power modulator able to deliver pulse repetition rates up to 1000 Hz, with 0.5 J per pulse energy output at 25 kV, was used as the pulsed power source. Positive pulse with a point-to-plane electrode configuration was used for the experiments. The concentration and production yield of hydrogen peroxide (H2O2) were quantitatively measured and orange II organic dye was treated, to evaluate the chemical properties of the discharge reactor. Experimental results show that the physical and chemical properties of water surface discharge are not influenced by pulse repetition rate, very different from those observed for under water discharge. The production yield of H2O2 and degradation rate per pulse of the dye did not significantly vary at different pulse repetition rates under a constant discharge mode on water surface. In addition, the solution temperature, pH, and conductivity for both water surface and underwater discharge reactors were measured to compare their plasma properties for different pulse repetition rates. The results confirm that surface discharge can be employed at high pulse repetition rates as a reliable and advantageous method for industrial and environmental decontamination applications.

  20. Properties of water surface discharge at different pulse repetition rates

    SciTech Connect

    Ruma,; Yoshihara, K.; Hosseini, S. H. R. Sakugawa, T.; Akiyama, H.; Akiyama, M.; Lukeš, P.

    2014-09-28

    The properties of water surface discharge plasma for variety of pulse repetition rates are investigated. A magnetic pulse compression (MPC) pulsed power modulator able to deliver pulse repetition rates up to 1000 Hz, with 0.5 J per pulse energy output at 25 kV, was used as the pulsed power source. Positive pulse with a point-to-plane electrode configuration was used for the experiments. The concentration and production yield of hydrogen peroxide (H₂O₂) were quantitatively measured and orange II organic dye was treated, to evaluate the chemical properties of the discharge reactor. Experimental results show that the physical and chemical properties of water surface discharge are not influenced by pulse repetition rate, very different from those observed for under water discharge. The production yield of H₂O₂ and degradation rate per pulse of the dye did not significantly vary at different pulse repetition rates under a constant discharge mode on water surface. In addition, the solution temperature, pH, and conductivity for both water surface and underwater discharge reactors were measured to compare their plasma properties for different pulse repetition rates. The results confirm that surface discharge can be employed at high pulse repetition rates as a reliable and advantageous method for industrial and environmental decontamination applications.

  1. Breakdown and dc discharge in low-pressure water vapour

    NASA Astrophysics Data System (ADS)

    Sivoš, J.; Škoro, N.; Marić, D.; Malović, G.; Petrović, Z. Lj

    2015-10-01

    In this paper we report studies of basic properties of breakdown, low-current Townsend discharge and high-current discharge regimes in water vapour. Paschen curves and the corresponding distributions of emission intensities at low current were recorded in the range of pd (pressure x electrode gap) from 0.1 to 10 Torrcm covering the region of Paschen minimum. From the experimental profiles we obtained effective ionization coefficient of water vapour for the E/N range 650 Td-7 kTd and fitted the results by using the extended Townsend analytical formula. Using the obtained ionization coefficient, we calculated the effective yield of secondary electrons from the copper cathode. Results of the measurements of Volt-Ampere characteristics in water vapour were presented together with the images of the axial structure of the discharge in a wide range of discharge currents for two pd values. Recorded profiles showed development of the spatial structure of the discharge in different operating regimes. We were able to identify conditions where processes induced by heavy particles, probably fast hydrogen atoms, are dominant in inducing emission from the discharge. Finally, standard scaling laws were tested for low current and glow discharges in water vapour.

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

    SciTech Connect

    Haggard, R.D.

    1996-08-12

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

  3. Optical Emission Spectroscopy of Microplasma Discharge in Sea Water

    NASA Astrophysics Data System (ADS)

    Gamaleev, Vladislav; Hatta, Akimitsu; Furuta, Hiroshi; Oh, Jun-Seok; Okamura, Yo; Kitamura, Kensuke; Hashimoto, Yusuke

    2015-09-01

    We have been investigating microplasma discharge in sea water for optical emission spectroscopy. Microplasma discharge in artificial sea water (10ASW) was carried using needle-to-plane platinum electrode system. The gap, between electrodes, was ranged from 10 to 60 microns. The electricity source was impulse generatorwith MOSFET switch and variable capacitance and inductance. The maximum voltage and current for this scheme were respectively 1 kV and 10 A, pulse width 10 μs. It has been confirmed that, using the micro-gap configuration, spark discharges were ignited at the conventional breakdown voltages below 1kV, even in the conductive sea water. Was noted formation of small bubbles before of the plasma ignition process. The mechanism of formation of these bubbles is mostly Joule heating because of high currents. It has been speculated that plasma discharge initiates in bubbles. Optical emission spectroscopy of microplasma in sea water was carried. In the spectra, emission peaks for H, O, Na, Mg, Ca, Cl and Pt were clearly detected. Besides the main components of 10ASW, contaminants from the electrodes appeared in the spectra. The characteristics of microplasma discharge in sea water and analysis of the optical emission spectra will be presented. This work was supported by JSPS KAKENHI Grant Number 26600129. The ASW was provided from Prof. Kei Okamura of Kochi University.

  4. Diagnostics of High-Intensity-Discharges

    NASA Astrophysics Data System (ADS)

    Adler, Helmar G.

    1996-05-01

    High intensity light sources have come a long way since the introduction of high pressure discharges in mercury and later in sodium. The introduction of other species (e.g. metal halides) into the discharge chemistry led to marked improvements in light intensity (lumens per watt or LPW) and the appearance of the light output (color rendering index or CRI). Many of these improvements have been achieved through qualitative understanding of the discharge and good engineering. The accurate predictions of discharge behavior and spectral power distribution through HID-models remains a difficult and challenging goal for lighting scientists. Modelling of a real lamp is complicated due to the high pressures in the discharge, the geometric influences of the discharge vessel, and the interactions between fills, wall materials and electrodes. The simultaneous use of solid-, liquid-, gaseous- and plasma-state descriptions, including for example effects of radiation transport, becomes necessary. Spectroscopic measurements have been and are still of highest value, not only to determine practical parameters like LPW and CRI, but also to determine species distributions and temperatures, eventually as a function of location in the discharge and time. These measurements are necessary not only for the quantitative understanding of the discharge mechanisms, but also to serve as a testbed for all simulation efforts. This paper will focus on diagnostic possibilities and opportunities using imaging data acquisition systems.

  5. High power impulse magnetron sputtering discharge

    SciTech Connect

    Gudmundsson, J. T.; Brenning, N.; Lundin, D.; Helmersson, U.

    2012-05-15

    The high power impulse magnetron sputtering (HiPIMS) discharge is a recent addition to plasma based sputtering technology. In HiPIMS, high power is applied to the magnetron target in unipolar pulses at low duty cycle and low repetition frequency while keeping the average power about 2 orders of magnitude lower than the peak power. This results in a high plasma density, and high ionization fraction of the sputtered vapor, which allows better control of the film growth by controlling the energy and direction of the deposition species. This is a significant advantage over conventional dc magnetron sputtering where the sputtered vapor consists mainly of neutral species. The HiPIMS discharge is now an established ionized physical vapor deposition technique, which is easily scalable and has been successfully introduced into various industrial applications. The authors give an overview of the development of the HiPIMS discharge, and the underlying mechanisms that dictate the discharge properties. First, an introduction to the magnetron sputtering discharge and its various configurations and modifications is given. Then the development and properties of the high power pulsed power supply are discussed, followed by an overview of the measured plasma parameters in the HiPIMS discharge, the electron energy and density, the ion energy, ion flux and plasma composition, and a discussion on the deposition rate. Finally, some of the models that have been developed to gain understanding of the discharge processes are reviewed, including the phenomenological material pathway model, and the ionization region model.

  6. Problems associated with estimating ground water discharge and recharge from stream-discharge records

    USGS Publications Warehouse

    Halford, K.J.; Mayer, G.C.

    2000-01-01

    Ground water discharge and recharge frequently have been estimated with hydrograph-separation techniques, but the critical assumptions of the techniques have not been investigated. The critical assumptions are that the hydraulic characteristics of the contributing aquifer (recession index) can be estimated from stream-discharge records; that periods of exclusively ground water discharge can be reliably identified; and that stream-discharge peaks approximate the magnitude and tinting of recharge events. The first assumption was tested by estimating the recession index from st earn-discharge hydrographs, ground water hydrographs, and hydraulic diffusivity estimates from aquifer tests in basins throughout the eastern United States and Montana. The recession index frequently could not be estimated reliably from stream-discharge records alone because many of the estimates of the recession index were greater than 1000 days. The ratio of stream discharge during baseflow periods was two to 36 times greater than the maximum expected range of ground water discharge at 12 of the 13 field sites. The identification of the ground water component of stream-discharge records was ambiguous because drainage from bank-storage, wetlands, surface water bodies, soils, and snowpacks frequently exceeded ground water discharge and also decreased exponentially during recession periods. The timing and magnitude of recharge events could not be ascertained from stream-discharge records at any of the sites investigated because recharge events were not directly correlated with stream peaks. When used alone, the recession-curve-displacement method and other hydrograph-separation techniques are poor tools for estimating ground water discharge or recharge because the major assumptions of the methods are commonly and grossly violated. Multiple, alternative methods of estimating ground water discharge and recharge should be used because of the uncertainty associated with any one technique.

  7. Water quality impacts of stormwater discharges to Santa Monica Bay.

    PubMed

    Bay, Steven; Jones, Burton H; Schiff, Kenneth; Washburn, Libe

    2003-01-01

    Urban stormwater runoff is a major source of contaminants to southern California's coastal waters, yet little is known about the fate and effects of these discharges. A 3-year multidisciplinary project was conducted to investigate the dispersion of stormwater plumes in Santa Monica Bay and the resultant impacts on the water column and benthos. This paper describes the toxicity component of the study. Sea urchin fertilization toxicity tests were conducted on stormwater from the two largest discharges into the bay: Ballona Creek, which drains a highly urbanized watershed, and Malibu Creek, which receives runoff from a largely undeveloped watershed. Every sample of Ballona Creek stormwater tested was toxic (usually >5 toxic units), while Malibu Creek stormwater had a lower frequency and magnitude of toxicity (usually <4 toxic units). Surface water samples collected within the Ballona Creek stormwater discharge plume were always toxic whenever the concentration of stormwater in the plume exceeded 10%. The toxic portion of the Ballona Creek stormwater plume extended more than 4 km offshore on one occasion. Toxicity identification studies indicated that zinc was the primary cause of toxicity in both Ballona Creek stormwater and the discharge plume. No acute sediment toxicity (10-day amphipod survival) was present in the study area, although interstitial water toxicity was present at some stations located near the mouth of Ballona Creek. Differences in watershed characteristics likely were responsible for the greater toxicity of the Ballona Creek stormwater discharge plume. The Ballona Creek watershed contained a greater degree of urbanization (83% versus 12% for Malibu Creek) and the presence of a network of concrete flood control channels resulted in a stormwater plume containing elevated concentrations of toxins that received less initial dilution (compared to Malibu Creek) in the nearshore environment. PMID:12648956

  8. High Power ECR Ion Thruster Discharge Characterization

    NASA Technical Reports Server (NTRS)

    Foster, John E.; Kamhawi, Hani; Haag, Thomas; Carpenter, Christian; Williams, George W.

    2006-01-01

    Electron cyclotron resonance (ECR) based ion thrusters with carbon based ion optics can potentially satisfy lifetime requirements for long duration missions (approximately 10 years) because grid erosion and cathode insert depletion issues are virtually eliminated. Though the ECR plasma discharge has been found to typically operate at slightly higher discharge losses than conventional DC ion thrusters (for high total thruster power applications), the discharge power fraction is small (less than 1 percent at 25 kW). In this regard, the benefits of increased life, low discharge plasma potentials, and reduced complexity are welcome tradeoffs for the associated discharge efficiency decrease. Presented here are results from discharge characterization of a large area ECR plasma source for gridded ion thruster applications. These measurements included load matching efficacy, bulk plasma properties via Langmuir probe, and plasma uniformity as measured using current probes distributed at the exit plane. A high degree of plasma uniformity was observed (flatness greater than 0.9). Additionally, charge state composition was qualitatively evaluated using emission spectroscopy. Plasma induced emission was dominated by xenon ion lines. No doubly charged xenon ions were detected.

  9. Fine-Water-Mist Multiple-Orientation-Discharge Fire Extinguisher

    NASA Technical Reports Server (NTRS)

    Butz, James R.; Turchi, Craig S.; Kimball, Amanda; McKinnon, Thomas; Riedel, Edward

    2010-01-01

    A fine-water-mist fire-suppression device has been designed so that it can be discharged uniformly in any orientation via a high-pressure gas propellant. Standard fire extinguishers used while slightly tilted or on their side will not discharge all of their contents. Thanks to the new design, this extinguisher can be used in multiple environments such as aboard low-gravity spacecraft, airplanes, and aboard vehicles that may become overturned prior to or during a fire emergency. Research in recent years has shown that fine water mist can be an effective alternative to Halons now banned from manufacture. Currently, NASA uses carbon dioxide for fire suppression on the International Space Station (ISS) and Halon chemical extinguishers on the space shuttle. While each of these agents is effective, they have drawbacks. The toxicity of carbon dioxide requires that the crew don breathing apparatus when the extinguishers are deployed on the ISS, and Halon use in future spacecraft has been eliminated because of international protocols on substances that destroy atmospheric ozone. A major advantage to the new system on occupied spacecraft is that the discharged system is locally rechargeable. Since the only fluids used are water and nitrogen, the system can be recharged from stores of both carried aboard the ISS or spacecraft. The only support requirement would be a pump to fill the water and a compressor to pressurize the nitrogen propellant gas. This system uses a gaseous agent to pressurize the storage container as well as to assist in the generation of the fine water mist. The portable fire extinguisher hardware works like a standard fire extinguisher with a single storage container for the agents (water and nitrogen), a control valve assembly for manual actuation, and a discharge nozzle. The design implemented in the proof-of-concept experiment successfully extinguished both open fires and fires in baffled enclosures.

  10. Biotoxicity characterization of a produced-water discharge in Wyoming

    SciTech Connect

    Mancini, E.R.; Stilwell, C.T. )

    1992-06-01

    The objectives of this paper are to document the physicochemical and aquatic toxicological quality of a beneficial-use produced-water discharge and its effect on a receiving stream in Wyoming. Fish and water-flea survival, growth, and reproduction tests indicated that the discharge and all other sampling stations passed the state effluent biomonitoring acute toxicity testing endpoints. while benthic macroinvertebrates were absent at the discharge point designated by the Natl. Pollutant Discharge Elimination System (NPDES), productive and reproducing populations were present at all other downstream and mixing-zone stations. This investigation confirmed the validity of the beneficial-use subcategory for this oilfield discharge.

  11. Statistical considerations in estimating organism concentrations in ballast water discharges

    EPA Science Inventory

    Sampling probabilities may affect the practical use of different ballast water performance standards which establish the acceptable concentration of organisms in ballast discharges. The International Maritime Organization (IMO) has initiated a ballast water standard of <10 viabl...

  12. Approaches to setting organism-based ballast water discharge standards

    EPA Science Inventory

    As a major vector by which foreign species invade coastal and freshwater waterbodies, ballast water discharge from ships is recognized as a major environmental threat. The International Maritime Organization (IMO) drafted an international ballast water treaty establishing ballast...

  13. Advanced high frequency partial discharge measuring system

    NASA Technical Reports Server (NTRS)

    Karady, George G.

    1994-01-01

    This report explains the Advanced Partial Discharge Measuring System in ASU's High Voltage Laboratory and presents some of the results obtained using the setup. While in operation an insulation is subjected to wide ranging temperature and voltage stresses. Hence, it is necessary to study the effect of temperature on the behavior of partial discharges in an insulation. The setup described in this report can be used to test samples at temperatures ranging from -50 C to 200 C. The aim of conducting the tests described herein is to be able to predict the behavior of an insulation under different operating conditions in addition to being able to predict the possibility of failure.

  14. Discharge indices for water quality loads

    USGS Publications Warehouse

    Vogel, R.M.; Stedinger, J.R.; Hooper, R.P.

    2003-01-01

    Effective discharge has been used to describe the streamflow level that is responsible for transporting the most sediment over the long term. Careful inspection reveals that this concept may not have been well defined, and different interpretations have led to conflicting representations. Because total load is ultimately the quantity of interest, we define a new index, the half-load discharge, which is that discharge above and below which half the total long-term load is transported. The value of the half-load discharge is derived for a reasonable model of flows and constituent concentration. The effective discharge has generally been thought to be a relatively common or frequent flood. The half-load discharge is generally a much greater and less frequent flow than commonly used estimators of the effective discharge. Relations provided here for the frequency and magnitude of the half-load discharge provide evidence that it is relatively rare floods that transport most of the sediment over the long term. These ideas apply to other constituents as well.

  15. Warm Atlantic water drives Greenland Ice Sheet discharge dynamics

    NASA Astrophysics Data System (ADS)

    Christoffersen, P.; Heywood, K. J.; Dowdeswell, J. A.; Syvitski, J. P.; Benham, T. J.; Mugford, R. I.; Joughin, I.; Luckman, A.

    2008-12-01

    Greenland outlet glaciers terminating in fjords experience seasonal fluctuations as well as abrupt episodes of rapid retreat and speed-up. The cause of abrupt speed-up events is not firmly established, but synchronous occurrences suggest that it is related to Arctic warming. Here, we report major warming of water masses in Kangerdlugssuaq Fjord, East Greenland, immediately prior to the fast retreat and speed-up of Kangerdlugssuaq Glacier in 2004-05. Our hydrographic data show that this event occurred when Atlantic water entered the fjord and increased temperature of surface water by 4°C and deep water by 1°C. On the basis of meteorological records and satellite-derived sea surface temperatures, which fluctuate by up to 4°C in periods of 2-3 years, we infer that inflow of Atlantic water is controlled by the direction and intensity of prevailing winds that force coastal and offshore currents. Our results demonstrate that Greenland Ice Sheet discharge dynamics are modulated by North Atlantic climate variability, which is identified by shifts in the position of atmospheric low pressure over the Labrador and Irminger seas. A persisting westerly position of the Icelandic Low since 1999 may explain why winters in Greenland have been particularly mild during the last decade and it is feasible that widespread and synchronous discharge fluctuations from outlet glaciers, which resulted in high rates of ice loss in southeast Greenland, are a consequence of this synoptic condition.

  16. High intensity discharge device containing oxytrihalides

    DOEpatents

    Lapatovich, W.P.; Keeffe, W.M.; Liebermann, R.W.; Maya, J.

    1987-06-09

    A fill composition for a high intensity discharge device including mercury, niobium oxytrihalide, and a molecular stabilization agent is provided. The molar ratio of niobium oxytrihalide to the molecular stabilization agent in the fill is in the range of from about 5:1 to about 7.5:1. Niobium oxytrihalide is present in the fill in sufficient amount to produce, by dissociation in the discharge, atomic niobium, niobium oxide, NbO, and niobium dioxide, NbO[sub 2], with the molar ratio of niobium-containing vapor species to mercury in the fill being in the range of from about 0.01:1 to about 0.50:1; and mercury pressure of about 1 to about 50 atmospheres at lamp operating temperature. There is also provided a high intensity discharge device comprising a sealed light-transmissive arc tube; the arc tube including the above-described fill; and an energizing means for producing an electric discharge within the arc tube. 7 figs.

  17. High intensity discharge device containing oxytrihalides

    DOEpatents

    Lapatovich, Walter P.; Keeffe, William M.; Liebermann, Richard W.; Maya, Jakob

    1987-01-01

    A fill composition for a high intensity discharge device including mercury, niobium oxytrihalide, and a molecular stabilization agent is provided. The molar ratio of niobium oxytrihalide to the molecular stabilization agent in the fill is in the range of from about 5:1 to about 7.5:1. Niobium oxytrihalide is present in the fill in sufficient amount to produce, by dissociation in the discharge, atomic niobium, niobium oxide, NbO, and niobium dioxide, NbO.sub.2, with the molar ratio of niobium-containing vapor species to mercury in the fill being in the range of from about 0.01:1 to about 0.50:1; and mercury pressure of about 1 to about 50 atmospheres at lamp operating temperature. There is also provided a high intensity discharge device comprising a sealed light-transmissive arc tube; the arc tube including the above-described fill; and an energizing means for producing an electric discharge within the arc tube.

  18. Enhanced submarine ground water discharge form mixing of pore water and estuarine water

    USGS Publications Warehouse

    Martin, Jonathan B.; Cable, Jaye E.; Swarzenski, Peter W.; Lindenberg, Mary K.

    2004-01-01

    Submarine ground water discharge is suggested to be an important pathway for contaminants from continents to coastal zones, but its significance depends on the volume of water and concentrations of contaminants that originate in continental aquifers. Ground water discharge to the Banana River Lagoon, Florida, was estimated by analyzing the temporal and spatial variations of Cl− concentration profiles in the upper 230 cm of pore waters and was measured directly by seepage meters. Total submarine ground water discharge consists of slow discharge at depths > ∼70 cm below seafloor (cmbsf) of largely marine water combined with rapid discharge of mixed pore water and estuarine water above ∼70 cmbsf. Cl− profiles indicate average linear velocities of ∼0.014 cm/d at depths > ∼70 cmbsf. In contrast, seepage meters indicate water discharges across the sediment-water interface at rates between 3.6 and 6.9 cm/d. The discrepancy appears to be caused by mixing in the shallow sediment, which may result from a combination of bioirrigation, wave and tidal pumping, and convection. Wave and tidal pumping and convection would be minor because the tidal range is small, the short fetch of the lagoon limits wave heights, and large density contacts are lacking between lagoon and pore water. Mixing occurs to ∼70 cmbsf, which represents depths greater than previously reported. Mixing of oxygenated water to these depths could be important for remineralization of organic matter.

  19. DC diaphragm discharge in water solutions of selected organic acids

    NASA Astrophysics Data System (ADS)

    Vyhnankova, Edita J.; Hammer, Malte U.; Reuter, Stephan; Krcma, Frantisek

    2015-07-01

    Effect of four simple organic acids water solution on a DC diaphragm discharge was studied. Efficiency of the discharge was quantified by the hydrogen peroxide production determined by UV-VIS spectrometry of a H2O2 complex formed with specific titanium reagent. Automatic titration was used to study the pH behaviour after the plasma treatment. Optical emission spectroscopy overview spectra were recorded and detailed spectra of OH band and Hβ line were used to calculate the rotational temperature and comparison of the line profile (reflecting electron concentration) in the acid solutions. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark

  20. 33 CFR 151.1511 - Ballast water discharge standard (BWDS).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Ballast water discharge standard... SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in...

  1. 33 CFR 151.2030 - Ballast water discharge standard (BWDS).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Ballast water discharge standard... SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in...

  2. 33 CFR 151.2030 - Ballast water discharge standard (BWDS).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Ballast water discharge standard... SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in...

  3. 33 CFR 151.2030 - Ballast water discharge standard (BWDS).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Ballast water discharge standard... SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in...

  4. 33 CFR 151.1511 - Ballast water discharge standard (BWDS).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Ballast water discharge standard... SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in...

  5. 33 CFR 151.1511 - Ballast water discharge standard (BWDS).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Ballast water discharge standard... SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in...

  6. Grafted cellulose for PAHs removal present in industrial discharge waters

    NASA Astrophysics Data System (ADS)

    Euvrard, Elise; Druart, Coline; Poupeney, Amandine; Crini, Nadia; Vismara, Elena; Lanza, Tommaso; Torri, Giangiacomo; Gavoille, Sophie; Crini, Gregorio

    2014-05-01

    , the grafted cellulose showed lower adsorption capacities of PAHs (about 40% for the total PAH content) when they were in real effluents than they were in synthetic solutions. However, it was observed that PAH composition in discharge waters was different than in synthetic solutions, qualitatively and quantitatively. Despite the presence of numerous other substances in industrial effluents at high concentrations (for instance metals equal to mg/L and salts to g/L), the grafted cellulose was demonstrated as suitable to remove organic substances at trace levels like PAHs (equal to ng/L). Reference: [1] Vismara E., Melone L., Gastaldi G., Cosentino C., Torri G. J. Hazardous Mat. 170 (2009) 798-808. Acknowledgements: The authors thank Agence de l'Eau, FEDER and the Conseil regional de Franche-Comté for financial support (NIRHOFEX Program).

  7. Degradation of Verapamil hydrochloride in water by gliding arc discharge.

    PubMed

    Krishna, Syam; Maslani, Alan; Izdebski, Tomasz; Horakova, Marta; Klementova, Sarka; Spatenka, Petr

    2016-06-01

    This study investigated the influence of gliding arc plasma discharge on the degradation of Verapamil hydrochloride in water. The plasma discharge was characterized by means of optical emission spectroscopy. Spectra of various atomic and molecular species were observed. Aqueous solution of Verapamil hydrochloride was exposed to gliding arc discharge operated in continuous discharge at atmospheric pressure and room temperature. The identification of Verapamil, the degradation mechanisms of Verapamil and its transformation products were performed using liquid chromatography - mass spectrometry (HPLC-MS). Experimental results indicate that the atmospheric pressure gliding arc plasma treatment has noticeable effects on Verapamil with satisfactory degradation efficiency. Plausible mechanisms of the degradation were discussed. PMID:26953731

  8. Ignition modes of nanosecond discharge with bubbles in distilled water

    NASA Astrophysics Data System (ADS)

    Hamdan, Ahmad; Cha, Min Suk

    2015-10-01

    Here, we present the microscopic physical characteristics of nanosecond discharges with an array of bubbles in distilled water. In particular, applying a single high-voltage pulse, four delayed intensified charge-coupled device cameras successfully visualized four successive images during a single discharge event. We identified three distinctive modes of ignition inside a bubble, depending on the relative location of the bubble with respect to pin-to-hollow needle electrodes when a single bubble was located in an inter-electrode gap of 1 mm: anode-driven ignition, cathode-driven ignition, and co-ignition near both electrodes. Anode- and cathode-driven ignitions evolved into either a complete propagation of the streamer or an incomplete propagation, which were limited in location by proximity to an ignition location, while co-ignitions consistently showed complete propagation. When we increased the gap to 2 mm to accommodate multiple bubbles in the gap, an ignited bubble near the cathode was able to cause the ignition of an upper adjacent bubble. Bubble-bubble interface zones can also be spots of ignition, such that we observed simultaneous co-ignitions in the zones of bubble-bubble interfaces and near electrodes with triple bubbles. We compared the experimental results of discharge propagation with different ignition modes between Ar, He, and N2 bubbles. In addition, numerical simulations for static electric fields reasonably supported observed ignition behavior such that field intensity was locally enhanced.

  9. Detail of downstream face of dam showing water being discharged ...

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

    Detail of downstream face of dam showing water being discharged through diversion tube. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  10. 61. VIEW OF SALT RIVER PROJECT WELL DISCHARGING WATER INTO ...

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

    61. VIEW OF SALT RIVER PROJECT WELL DISCHARGING WATER INTO THE ARIZONA CANAL NEAR 47TH AVENUE, LOOKING SOUTH Photographer: James Eastwood, July 1990 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ

  11. Testing and analysis of PSV discharge force with water seal

    SciTech Connect

    Gu Fangyu; Li Pengzhou; Peng Yunkang

    1996-12-01

    Pilot-operated safety valve (PSV) of pressurizer is an important equipment in a NPP. It is an advanced type of safety valve and its discharge force is a key parameter to the design of overpressure protection systems. The discharge process can be affected by many complicated factors like volume and temperature distribution of water seal, discharge flow rate, and so on. One set of tests on discharge force have been completed under three water seal volumes and different temperature distributions by using a particular target to measure the transient dynamic response and modal analytical method to obtain the force function on the target. Meanwhile, the code Relap5/MOD2C is applied to calculate the force function. The results of tests and code analysis show that the application of Relap5/MOD2C in the calculation of PSV discharge force is successful and it has been used in the Qinshan NPP.

  12. Investigation of microplasma discharge in sea water for optical emission spectroscopy

    NASA Astrophysics Data System (ADS)

    Gamaleev, Vladislav; Okamura, Yo; Kitamura, Kensuke; Hashimoto, Yusuke; Oh, Jun-Seok; Furuta, Hiroshi; Hatta, Akimitsu

    2016-07-01

    Microplasma discharge in sea water for optical emission spectroscopy was investigated using a needle-to-plane electrode system. The electrodes of a Pd needle and a Pt plate were placed with a gap of 25 µm in typical artificial sea water or locally sampled natural deep sea water. A pulse current source, consisting of a MOSFET switch, a capacitor, an inductor and the resistance of the sea water between the electrodes, was used. The circuit parameters were optimized to decrease the breakdown voltage and the spark duration to suppress erosion of the electrodes. Using a microgap configuration, spark discharges were reproducibly ignited in the highly conductive sea water at low breakdown voltages. The ignition of spark discharges required not only a critical voltage sufficient for breakdown, but also a critical energy for preheating of the sea water, sufficient for bubble formation. The possibility of using optical emission spectroscopy of microplasma in water is shown for identifying elemental composition of sea water.

  13. Health risk assessment for radium discharged in produced waters

    SciTech Connect

    Hamilton, L.D.; Meinhold, A.F.; Nagy, J.

    1991-12-31

    Produced water generated during the production of oil and gas can contain enhanced levels of radium. This naturally occurring radioactive material (NORM) is discharged into freshwater streams, estuarine, coastal and outer continental shelf waters. Large volumes of produced waters are discharged to coastal waters along the Gulf Coast of Louisiana. The Gulf of Mexico is an important producer of fish and shellfish, and there is concern that radium discharged to coastal Louisiana could contaminate fish and shellfish used by people for food, and present a significant increase in cancer risk. This paper describes a screening-level assessment of the potential cancer risks posed by radium discharged to coastal Louisiana in oil-field produced waters. This screening analysis was performed to determine if a more comprehensive and realistic assessment is necessary, and because of the conservative assumptions embedded in the analysis overestimates the risk associated with the discharge of radium in produced waters. Two isotopes of radium (Ra-226 and Ra-228) are the radionuclides of most concern in produced water in terms of potential human health effects.

  14. Health risk assessment for radium discharged in produced waters

    SciTech Connect

    Hamilton, L.D.; Meinhold, A.F.; Nagy, J.

    1991-01-01

    Produced water generated during the production of oil and gas can contain enhanced levels of radium. This naturally occurring radioactive material (NORM) is discharged into freshwater streams, estuarine, coastal and outer continental shelf waters. Large volumes of produced waters are discharged to coastal waters along the Gulf Coast of Louisiana. The Gulf of Mexico is an important producer of fish and shellfish, and there is concern that radium discharged to coastal Louisiana could contaminate fish and shellfish used by people for food, and present a significant increase in cancer risk. This paper describes a screening-level assessment of the potential cancer risks posed by radium discharged to coastal Louisiana in oil-field produced waters. This screening analysis was performed to determine if a more comprehensive and realistic assessment is necessary, and because of the conservative assumptions embedded in the analysis overestimates the risk associated with the discharge of radium in produced waters. Two isotopes of radium (Ra-226 and Ra-228) are the radionuclides of most concern in produced water in terms of potential human health effects.

  15. Evaluating the generation efficiency of hydrogen peroxide in water by pulsed discharge over water surface and underwater bubbling pulsed discharge

    NASA Astrophysics Data System (ADS)

    Shang, Kefeng; Li, Jie; Wang, Xiaojing; Yao, Dan; Lu, Na; Jiang, Nan; Wu, Yan

    2016-01-01

    Pulsed electric discharge over water surface/in water has been used to generate reactive species for decomposing the organic compounds in water, and hydrogen peroxide (H2O2) is one of the strong reactive species which can be decomposed into another stronger oxidative species, hydroxyl radical. The production efficacy of H2O2 by a gas phase pulsed discharge over water surface and an underwater bubbling pulsed discharge was evaluated through diagnosis of H2O2 by a chemical probe method. The experimental results show that the yield and the production rate of H2O2 increased with the input energy regardless of the electric discharge patterns, and the underwater bubbling pulsed discharge was more advantageous for H2O2 production considering both the yield and the production rate of H2O2. Results also indicate that the electric discharge patterns also influenced the water solution properties including the conductivity, the pH value and the water temperature.

  16. Characterization of highly transient EUV emitting discharges

    NASA Astrophysics Data System (ADS)

    van der Mullen, Joost; Kieft, Erik; Broks, Bart

    2006-07-01

    The method of disturbed Bilateral Relations (dBR) is used to characterize highly transient plasmas that are used for the generation of Extreme Ultra Violet (EUV), i.e. radiation with a wavelength around 13.5 nm. This dBR method relates equilibrium disturbing to equilibrium restoring processes and follows the degree of equilibrium departure from the global down to the elementary plasma-level. The study gives global values of the electron density and electron temperature. Moreover, it gives a method to construct the atomic state distribution function (ASDF). This ASDF, which is responsible for the spectrum generated by the discharge, is found to be far from equilibrium. There are two reasons for this: first, systems with high charge numbers radiate strongly, second the highly transient behaviour makes that the distribution over the various ionization stages lags behind the temperature evolution.

  17. Sounding experiments of high pressure gas discharge

    SciTech Connect

    Biele, Joachim K.

    1998-07-10

    A high pressure discharge experiment (200 MPa, 5{center_dot}10{sup 21} molecules/cm{sup 3}, 3000 K) has been set up to study electrically induced shock waves. The apparatus consists of the combustion chamber (4.2 cm{sup 3}) to produce high pressure gas by burning solid propellant grains to fill the electrical pump chamber (2.5 cm{sup 3}) containing an insulated coaxial electrode. Electrical pump energy up to 7.8 kJ at 10 kV, which is roughly three times of the gas energy in the pump chamber, was delivered by a capacitor bank. From the current-voltage relationship the discharge develops at rapidly decreasing voltage. Pressure at the combustion chamber indicating significant underpressure as well as overpressure peaks is followed by an increase of static pressure level. These data are not yet completely understood. However, Lorentz forces are believed to generate pinching with subsequent pinch heating, resulting in fast pressure variations to be propagated as rarefaction and shock waves, respectively. Utilizing pure axisymmetric electrode initiation rather than often used exploding wire technology in the pump chamber, repeatable experiments were achieved.

  18. Risk assessment for produced water discharges to Louisiana open bays

    SciTech Connect

    Meinhold, A.F.; Holtzman, S.; DePhillips, M.P.

    1995-11-01

    Potential human health and environmental impacts from discharge of produced water to the Gulf of Mexico concern regulators at the State and Federal levels, environmental interest groups, industry and the public. Current regulations in the United States require or propose azero discharge limit for coastal facilities based primarily on studies performed in low energy,poorly flushed environments. Produced water discharges in coastal Louisiana, however,include a number located in open bays, where potential and impacts are likely to be larger than the minimal impacts associated with offshore discharges, but smaller than those demonstrated in low-energy canal environments. This paper summarizes results of a conservative screening-level health and ecological assessment for contaminants discharged in produced water to open bays in Louisiana, and reports results of a probabilistic human health risk assessment for radium and lead. The initial human health and ecological risk assessments consisted of conservative screening analyses that identified potentially important contaminants and excluded others from further consideration. A more quantitative probabilistic risk assessment was completed for the human health effects of the two contaminants identified in this screen: radium and lead. This work is part of a series of studies on the health and ecological risks from discharges of produced water to the Gulf of Mexico, supported by the United States Department of Energy (USDOE).

  19. Pulsed electrical discharge in gas bubbles in water

    NASA Astrophysics Data System (ADS)

    Gershman, Sophia

    A phenomenological picture of pulsed electrical discharge in gas bubbles in water is produced by combining electrical, spectroscopic, and imaging methods. The discharge is generated by applying one microsecond long 5 to 20 kilovolt pulses between the needle and disk electrodes submerged in water. A gas bubble is generated at the tip of the needle electrode. The study includes detailed experimental investigation of the discharge in argon bubbles and a brief look at the discharge in oxygen bubbles. Imaging, electrical characteristics, and time-resolved optical emission data point to a fast streamer propagation mechanism and formation of a plasma channel in the bubble. Spectroscopic methods based on line intensity ratios and Boltzmann plots of line intensities of argon, atomic hydrogen, and argon ions and the examination of molecular emission bands from molecular nitrogen and hydroxyl radicals provide evidence of both fast beam-like electrons and slow thermalized ones with temperatures of 0.6 -- 0.8 electron-volts. The collisional nature of plasma at atmospheric pressure affects the decay rates of optical emission. Spectroscopic study of rotational-vibrational bands of hydroxyl radical and molecular nitrogen gives vibrational and rotational excitation temperatures of the discharge of about 0.9 and 0.1 electron-volt, respectively. Imaging and electrical evidence show that discharge charge is deposited on the bubble wall and water serves as a dielectric barrier for the field strength and time scales of this experiment. Comparing the electrical and imaging information for consecutive pulses applied at a frequency of 1 Hz indicates that each discharge proceeds as an entirely new process with no memory of the previous discharge aside from long-lived chemical species, such as ozone and oxygen. Intermediate values for the discharge gap and pulse duration, low repetition rate, and unidirectional character of the applied voltage pulses make the discharge process here unique

  20. Electric discharge in the water: physics of formation and radiative characteristics.

    NASA Astrophysics Data System (ADS)

    Anpilov, Andrei; Barkhudarov, Eduard; Kozlov, Yurii; Kossyi, Igor; Silakov, Valerii; Temchin, Savelii

    2004-09-01

    ELECTRIC DISCHARGE IN THE WATER: PHYSICS OF FORMATION AND RADIATIVE CHARACTERISTICS 2.10. Lighting plasmas. 2.26. Other plasma topics. A.M.Anpilov, E.M.Barkhudarov, Yu.N.Kozlov, I.A.Kossyi, V.P.Silakov and S.M.Temchin Two types of electric discharge in the water have been investigated: discharge between two electrodes and multielectrode gliding surface discharge. Results are presented from experimental studies of the prebreakdown phase of an electric discharge between the point (anode) and plane (cathode) electrodes immersed in the water with different initial conductivity. When a high-voltage pulse is applied, the induced conductivity is detected in the discharge gap. Its value is one order of magnitude higher than the initial one. It is shown that the induced conductivity increases almost linearly with initial conductivity. The induced conductivity correlates with the UV emission from the cathode surface. A qualitative analysis of the experimental results is performed. Investigations of a spectrum of radiation of discharge in water have been carried out. On the base of broadening and shifting of atomic hydrogen and oxygen lines electron density in a prebreakdown as well as breakdown stages has been determined. Results are presented from investigations of multispark electric discharge in water excited along multielectrode metal-dielectric systems with gas supply into the interelectrode gaps. The intensity distribution of discharge radiation in the region covering the biologically active soft UV (190 £l£430 nm) has been determined and the absolute number of quanta in this wavelength interval has been measured. The potentiality of the gliding surface discharge in water for its disinfection is analysed.

  1. ESTIMATING FLOW AND FLUX OF GROUND-WATER DISCHARGE USING WATER TEMPERATURE AND VELOCITY. (R827961)

    EPA Science Inventory

    The nature of ground water discharge to a stream has important implications for nearby ground water flow, especially with respect to contaminant transport and well-head protection. Measurements of ground water discharge were accomplished in this study using (1) differences bet...

  2. Discharge current modes of high power impulse magnetron sputtering

    SciTech Connect

    Wu, Zhongzhen Xiao, Shu; Ma, Zhengyong; Cui, Suihan; Ji, Shunping; Pan, Feng; Tian, Xiubo; Fu, Ricky K. Y.; Chu, Paul K.

    2015-09-15

    Based on the production and disappearance of ions and electrons in the high power impulse magnetron sputtering plasma near the target, the expression of the discharge current is derived. Depending on the slope, six possible modes are deduced for the discharge current and the feasibility of each mode is discussed. The discharge parameters and target properties are simplified into the discharge voltage, sputtering yield, and ionization energy which mainly affect the discharge plasma. The relationship between these factors and the discharge current modes is also investigated.

  3. Fast imaging of intermittent electrospraying of water with positive corona discharge

    NASA Astrophysics Data System (ADS)

    Pongrác, B.; Kim, H. H.; Janda, M.; Martišovitš, V.; Machala, Z.

    2014-08-01

    The effect of the electrospraying of water in combination with a positive direct current (dc) streamer corona discharge generated in air was investigated in this paper. We employed high-speed camera visualizations and oscilloscopic discharge current measurements in combination with an intensified charge-coupled device camera for fast time-resolved imaging. The repetitive process of Taylor cone formation and droplet formation from the mass fragments of water during the electrospray was visualized. Depending on the applied voltage, the following intermittent modes of electrospraying typical for water were observed: dripping mode, spindle mode, and oscillating-spindle mode. The observed electrospraying modes were repetitive with a frequency of a few hundreds of Hz, as measured from the fast image sequences. This frequency agreed well with the frequency of the measured streamer current pulses. The presence of filamentary streamer discharges at relatively low voltages probably prevented the establishment of a continuous electrospray in the cone-jet mode. After each streamer, a positive glow corona discharge was established on the water filament tip, and it propagated from the stressed electrode along with the water filament elongation. The results show a reciprocal character of intermittent electrospraying of water, and the presence of corona discharge, where both the electrospray and the discharge affect each other. The generation of a corona discharge from the water cone depended on the repetitive process of the cone formation. Also, the propagation and curvature of the water filament were influenced by the discharge and its resultant space charge. Furthermore, these phenomena were partially influenced by the water conductivity.

  4. Spatial organization of stream water discharge and chemistry in forested headwaters

    NASA Astrophysics Data System (ADS)

    Egusa, T.; Ohte, N.; Oda, T.; Suzuki, M.

    2013-12-01

    It has long been known that, in small catchments, stream water discharge and chemistry are highly variable but the variability decreases gradually with an increase in the catchment area. Wood et al. (1988) showed that model calculations of infiltration and the runoff rate became constant above a certain threshold area. They defined the threshold area as the representative elementary area (REA) and stated that above the REA only minimum knowledge of the underlying parameters is needed to explain the stream water discharge and chemistry. Subsequently, empirical studies were conducted in several catchments. These studies all verified the existence of an REA in real catchments and indicated that the REA values differed among catchments. The results also suggested that the confluence processes of stream water discharge and chemistry differed among catchments. However, it has not been clarified how the confluence processes behave and why processes differ among catchments. One of the unclear things to resolve is whether the variability of discharge and chemistry among small catchments can be regarded as randomness or if it is organized. Two previous studies examined it and reported the opposite results. Woods et al. (1995) reported that organization was apparent from their observations of specific discharge. However, Asano and Uchida (2010) stated that their results for SiO2 could be regarded as randomness. These studies targeted different observed items and different catchments. Therefore, general knowledge about organization of stream water discharge and chemistry has not been obtained. We observed spatial variability of stream water discharge and chemistry and examined the existence of spatial organization by using the statistical method. Our objective was to elucidate whether the spatial organization exists about stream water discharge and chemistry. Observations were conducted in three forested catchments in Japan. Snapshot samplings of stream water discharge and

  5. Publ 420, management of water discharge

    SciTech Connect

    Not Available

    1990-01-01

    This book describes coagulation and flocculation theory and methods used by petroleum refiners to optimize end-of-pipe treatment of process water and the dewatering of sludges. Some of the topics covered are systems optimization; the theory and mechanisms of coagulation and flocculation; properties of suspended solids; chemicals used for coagulation and flocculation, including synthetic polyelectrolytes; destabilization models; and recommendations for use of granular-media filtration, dissolved- and induced-air flotation, activated-sludge treatment, and sludge dewater.

  6. How can we get a better estimation for vegetation water uptake in groundwater discharge areas using high frequency soil moisture data

    NASA Astrophysics Data System (ADS)

    Gribovszki, Zoltán; Kalicz, Péter

    2014-05-01

    Evapotranspiration induces diurnal signal of soil moisture, and also of water table in shallow water table environments. Shallow water table diurnal signal was widespreadly used for estimation of groundwater uptake by plants. The limitation of all groundwater signal based methods lies in the difficulty of specific yield estimation. In this paper a new technique is demonstrated by which more exact evapotranspiration values can be calculated from aggregated soil moisture profile dataset taking into account diurnally changing replenishment rate. The technique is of great benefit to provide sufficient accuracy without soil specific calibration. New technique was successfully tested on the soil moisture profile dataset of a riparian alder forest in Hidegvíz Valley experimental catchment in the summer of 2013. Comparing traditional evapotranspiration estimation from soil moisture data the new technique gives much higher water uptake taking into account soil moisture continuous replenishment from shallow groundwater. The water uptake seems to be acceptable if oasis effect is taken into account in a well watered valley situation in a period when hot and dry environment can add significant amount of heat enhancing transpiration. Soil moisture replenishment rates from groundwater can provide high portion (60-80This publication has been supported by funds from: OTKA (NN 79835) and TÁMOP-4.2.2.A-11/1/KONV-2012-0013 project. The research of Zoltán Gribovszki was supported by the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TÁMOP 4.2.4. A/2-11-1-2012-0001 'National Excellence Program'. Keywords: groundwater evapotranspiration, diurnal fluctuation, forest vegetation

  7. Pulse volume discharges in high pressure gases

    NASA Astrophysics Data System (ADS)

    Yamshchikov, V. A.

    2015-11-01

    New approach for suppression of plasma inhomogeneities and instabilities in the volume self-sustained discharge is offered. The physical model is offered and conditions of obtaining extremely homogeneous self-sustained discharge are defined (with full suppression of plasma inhomogeneity and instability). Results of calculations agree with experiments.

  8. Effects of a nearshore wastewater discharge: Water column and sediment pore water toxicity

    SciTech Connect

    Krause, P.R.; Carr, R.S.

    1995-12-31

    The relationship between water column and sediment pore water toxicity was investigated near a municipal-industrial wastewater discharge in southern Texas. Toxicity associated with effluent distributions in the water column are known to vary in both time and space. Toxicity of sediment, however, is often more stable over time. Sediment can serve as a long-term integrator of toxicity in areas subject to chronic exposure of effluents. This study addressed the relationship between water column toxicity and that found in the sediments on both spatial and temporal scales. Four 2 Km transacts were established around a nearshore wastewater outfall. Eight stations along each transact were sampled for both surface waters and sediment pore water toxicity. Toxicity was determined using a modified sea urchin fertilization test. Surface waters were sampled and tested for eight consecutive months, while sediment pore waters were sampled on three occasions over the length of this study. Results have shown that toxicity in receiving waters was a good indicator to trace movements of the highly variable effluent plume. The distribution of effluent in the water column, and hence water column toxicity, was primarily driven by local wind conditions. Toxicity in sediment porewater was, much less variable and more evenly distributed over the study site. Sediment pore water toxicity was also a good predictor of the distribution of benthic infaunal invertebrates over much of the study site.

  9. Water discharge from Lone Star Geyser, Yellowstone NP, WY

    NASA Astrophysics Data System (ADS)

    Murphy, F.; Randolph-Flagg, N. G.; Hurwitz, S.

    2014-12-01

    During four days in April, 2014 we made a series of measurements at Lone Star Geyser in Yellowstone National Park, WY. This work included the continuous measurement of liquid water discharge from the geyser and some nearby not springs, and concurrent meteorological measurements. The discharge of the geyser and the hot springs was measured in channels that carry the water to the Firehole River. We found that average measured discharge varies from day to night, likely due to melting of geyser-generated and meteoric snow during warmer daylight hours and freezing of erupted liquid and vapor during the night. The nearby hot springs contribute a nearly constant flow of about 3 l/s to the Firehole River, while during eruptions the total discharge increases to a maximum of about 25 l/s. Two small geysers within 5 meters of the Lone Star Geyser cone were observed to erupt during a time when Lone Star Geyser was not erupting. The water discharged from these small geysers is a very small fraction of that from Lone Star Geyser.

  10. [High-quality hospital discharge summaries - general practitioners expectations].

    PubMed

    Bally, Klaus; Lingenhel, Sabine; Tschudi, Peter

    2012-01-01

    Hospital discharge summaries ensure treatment continuity after hospital discharge. In Switzerland discharge letters are a celebrated custom and a tool for training young colleagues. The primary purpose is to guarantee high-quality care of patients treated by hospital staff and general practitioners. From the perspective of the patient's general practitioner discharge summaries should convey current and accurate medically important patient data to the physician responsible for follow-up care. In the era of highly developed electronic data transfer and introduction of diagnose related groups (DRGs), it will be necessary to transmit hospital discharge information selectively to different target groups. Nevertheless data protection and medical secret must be complied with. PMID:22198930

  11. Residence time of water discharging from the Hanging Gardens of Zion Park

    USGS Publications Warehouse

    Kimball, B.A.; Christensen, P.K.

    1996-01-01

    The Hanging Gardens are a unique feature of Zion National Park. Knowledge of the source and residence time of water discharging from the Hanging Gardens is necessary to help preserve these features. Ground-water chemical and isotopic data distinguish the discharge from seeps and springs into two groups, one of low and one of high conductivity. Water with low conductivity likely originates as recharge near the steps and springs, and it only interacts with the Navajo Sandstone. High conductivity water, on the other hand, originates as recharge on the tops of plateaus to the east, where it interacts with marine rocks of the Carmel Formation. Carbon dating of these ground waters indicates that the low conductivity water is essentially modern recharge, while the high conductivity water was recharged 1,000 to 4,000 years ago.The Hanging Gardens are a unique feature of Zion National Park. Knowledge of the source and residence time of water discharging from the Hanging Gardens is necessary to help preserve these features. Ground-water chemical and isotopic data distinguish the discharge from seeps and springs into two groups, one of low and one of high conductivity. Water with low conductivity likely originates as recharge near the seeps and springs, and it only interacts with the Navajo Sandstone. High conductivity water, on the other hand, originates as recharge on the tops of plateaus to the cast, where it interacts with marine rocks of the Carmel Formation. Carbon dating of these ground waters indicates that the low conductivity water is essentially modern recharge, while the high conductivity water was recharged 1,000 to 4,000 years ago.

  12. 1. Credit TCL. South elevation. Note water discharging from all ...

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

    1. Credit TCL. South elevation. Note water discharging from all five tailraces. The portion of the powerhouse erected in 1900-01 is on the right. The 1906 and 1908 additions are on the left. - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  13. PURIFICATION OF WATERS DISCHARGED FROM POLISH LIGNITE MINES

    EPA Science Inventory

    The exploitation of lignite deposits is linked with the necessity of lowering the groundwater table and dewatering the mine of precipitation. A large percentage of the discharge waters requires purification prior to delivery of receiving streams. The chief pollutants of these wat...

  14. FTIR Analysis of Flowing Afterglow from a High-Frequency Spark Discharge

    NASA Astrophysics Data System (ADS)

    White, Allen; Hieftje, Gary M.; Ray, Steve; Pfeuffer, Kevin

    2014-06-01

    Plasmas are often used as ionization sources for ambient mass spectrometry (AMS). Here, the flowing afterglow of a novel high-energy spark discharge system, operated in nitrogen at high repetition rates, is investigated as a source for AMS. The spark discharge here is the same as that of an automobile ignition circuit.Combustion in automobile engines is initiated by a spark ignition system that is designed to deliver short-duration,high-voltage sparks to multiple engine cylinders. The arrangement utilized in this study is a modified discharge configuration designed to produce similarly short-duration, high-voltage discharges. It consists of an automotive ignition coil that is activated by a spark initiation circuit that discharges in turn into a cell with neutral gas input flow and ultimately into the collection orifice of a mass spectrometer. The discharge voltage is approximately 40kV at 800 Hz. High-frequency spark discharges in a nitrogen flow produce reagent ions such as NO+. In order to better evaluate the effectiveness of the discharge in producing reagent ions, an FTIR is utilized to measure IR active species such as nitric oxide, hydroxide, ozone, and water in the afterglow of the spark discharge during variation of discharge parameters. Time-resolved IR emission spectra provide additional insight into the reagent ion production mechanisms.

  15. Long-living plasmoids from an atmospheric water discharge

    NASA Astrophysics Data System (ADS)

    Versteegh, A.; Behringer, K.; Fantz, U.; Fussmann, G.; Jüttner, B.; Noack, S.

    2008-05-01

    Ball-like plasmoids were generated from discharging a capacitor bank via a water surface. In the autonomous stage after current zero they have diameters up to 0.2 m and lifetimes of some hundreds of milliseconds, thus resembling ball lightning in some way. They were studied by applying high speed cameras, electric probes, calorimetric measurements, and spectroscopy. The plasmoids are found to consist of a true plasma surrounded by a cold envelope. Decreasing electron densities in the order of 1020-1022 m-3 were measured from Stark broadening in the initial (formation) phase. The electron temperature is estimated to be 2000-5000 K during most of the plasmoid's lifetime. The temperature of the neutral particles can exceed 1300 K. Calcium hydroxide molecular band emission is the major source of visible radiation in the autonomous phase. Chemiluminescence reactions between dissociation products of water and dissolved calcium are proposed as a source for this emission. The plasmoid's colder boundary layer consists of electric double layers that may be attributed to the characteristic shape of the balls.

  16. High-repetition-rate short-pulse gas discharge.

    PubMed

    Tulip, J; Seguin, H; Mace, P N

    1979-09-01

    A high-average-power short-pulse gas discharge is described. This consists of a volume-preionized transverse discharge of the type used in gas lasers driven by a Blumlein energy storage circuit. The Blumlein circuit is fabricated from coaxial cable, is pulse-charged from a high-repetition-rate Marx-bank generator, and is switched by a high-repetition-rate segmented rail gap. The operation of this discharge under conditions typical of rare-gas halide lasers is described. A maximum of 900 pps was obtained, giving a power flow into the discharge of 30 kW. PMID:18699678

  17. Bio-Decontamination of Water and Surfaces by DC Discharges in Atmospheric Air

    NASA Astrophysics Data System (ADS)

    Machala, Zdenko; Tarabová, Barbora; Pelach, Michal; Šipoldová, Zuzana; Hensel, Karol; Janda, Mário; Šikurová, Libuša

    Two types of DC-driven atmospheric air discharges, including a streamer corona and a transient spark with short high current pulses of limited energy, were employed for bio-decontamination of water and various surfaces (agar plates, plastic foils, human teeth) contaminated by bacteria or spores (Salmonella typhimurium, Bacillus cereus). Both discharges generate cold non-equilibrium plasma. The discharges combined with the electro-spraying of the treated water through the needle electrode lead to fast and efficient bio-decontamination. Experiments comparing direct and indirect plasma effects, oxidation stress measurements in the cell membranes, and chemical changes induced in the treated water enable assessment of the plasma agents being responsible for microbial inactivation. Radicals and reactive oxygen species seem to be dominant biocidal agents, although deeper understanding of the plasma-induced water chemistry and of the temporal evolution of the bio-inactivation processes is needed.

  18. Characterizing hydrology and the importance of ground-water discharge in natural and constructed wetlands

    USGS Publications Warehouse

    Hunt, Randall J.; Walker, John F.; Krabbenhoft, David P.

    1999-01-01

    Although considered the most important component for the establishment and persistence of wetlands, hydrology has been hard to characterize and linkages between hydrology and other environmental conditions are often poorly understood. In this work, methods for characterizing a wetland’s hydrology from hydrographs were developed, and the importance of ground water to the physical and geochemical conditions in the root zone was investigated. Detailed sampling of nearly continuous hydrographs showed that sites with greater ground-water discharge had higher water tables and more stable hydrographs. Subsampling of the continuous hydrograph failed to characterize the sites correctly, even though the wetland complex is located in a strong regional ground-water-discharge area. By comparing soil-moisture-potential measurements to the water-table hydrograph at one site, we noted that the amount of root-zone saturation was not necessarily driven by the water-table hydrograph but can be a result of other soil parameters (i.e., soil texture and associated capillary fringe). Ground-water discharge was not a significant determinant of maximum or average temperatures in the root zone. High ground-water discharge was associated with earliest date of thaw and shortest period of time that the root zone was frozen, however. Finally, the direction and magnitude of shallow ground-water flow was found to affect the migration and importance of a geochemical species. Areas of higher ground-water discharge had less downward penetration of CO2 generated in the root zone. In contrast, biotically derived CO2 was able to penetrate the deeper ground-water system in areas of ground-water recharge. Although ground-water flows are difficult to characterize, understanding these components is critical to the success of wetland restoration and creation efforts.

  19. Can humic water discharge counteract eutrophication in coastal waters?

    PubMed

    Andersson, Agneta; Jurgensone, Iveta; Rowe, Owen F; Simonelli, Paolo; Bignert, Anders; Lundberg, Erik; Karlsson, Jan

    2013-01-01

    A common and established view is that increased inputs of nutrients to the sea, for example via river flooding, will cause eutrophication and phytoplankton blooms in coastal areas. We here show that this concept may be questioned in certain scenarios. Climate change has been predicted to cause increased inflow of freshwater to coastal areas in northern Europe. River waters in these areas are often brown from the presence of high concentrations of allochthonous dissolved organic carbon (humic carbon), in addition to nitrogen and phosphorus. In this study we investigated whether increased inputs of humic carbon can change the structure and production of the pelagic food web in the recipient seawater. In a mesocosm experiment unfiltered seawater from the northern Baltic Sea was fertilized with inorganic nutrients and humic carbon (CNP), and only with inorganic nutrients (NP). The system responded differently to the humic carbon addition. In NP treatments bacterial, phytoplankton and zooplankton production increased and the systems turned net autotrophic, whereas the CNP-treatment only bacterial and zooplankton production increased driving the system to net heterotrophy. The size-structure of the food web showed large variations in the different treatments. In the enriched NP treatments the phytoplankton community was dominated by filamentous >20 µm algae, while in the CNP treatments the phytoplankton was dominated by picocyanobacteria <5 µm. Our results suggest that climate change scenarios, resulting in increased humic-rich river inflow, may counteract eutrophication in coastal waters, leading to a promotion of the microbial food web and other heterotrophic organisms, driving the recipient coastal waters to net-heterotrophy. PMID:23637807

  20. Water withdrawals, use, discharge, and trends in Florida, 2000

    USGS Publications Warehouse

    Marella, Richard L.

    2004-01-01

    River, Lake Okeechobee and associated canals, and the canals associated with the headwaters of the Upper St. Johns River. Freshwater withdrawals increased 46 percent and saline water withdrawals increased 25 percent in Florida between 1970 and 2000. Ground-water withdrawals increased 82 percent, and surface-water withdrawals increased 10 percent during this period. Between 1970 and 2000, total freshwater withdrawals increased for public supply by 176 percent and for agricultural self-supplied by 87 percent; withdrawals for commercial-industrial self-supplied decreased by 37 percent, and power generation (thermoelectric) decreased by 57 percent. Recreational irrigation withdrawals increased 127 percent between 1985 and 2000. Between 1995 and 2000, freshwater withdrawals increased 13 percent, and saline withdrawals increased 9 percent. An estimated 52 percent of the freshwater withdrawn in Florida was consumed; the remaining 48 percent was returned for further use. Domestic wastewater discharged in 2000 totaled 1,495 Mgal/d, of which 44 percent was discharged to surface waters, 34 percent to the ground through land application systems, and 22 percent to deep injection wells. Domestic wastewater discharge increased by 33 percent between 1985 and 2000, but decreased by 3 percent between 1995 and 2000. An estimated 11.21 million people were served by domestic wastewater systems in 2000, whereas the remaining 4.77 million people discharged wastewater to more than 1.95 million septic tanks. Discharge from the septic tanks was estimated to be 263 Mgal/d in 2000.

  1. ROS/RNS Production in Water Using Various Discharge Plasma

    NASA Astrophysics Data System (ADS)

    Takahashi, Kazuhiro; Satoh, Kohki; Itoh, Hidenori; Kawaguchi, Hideki; Timoshkin, Igor; Given, Martin; MacGregor, Scott

    2015-09-01

    A pulsed discharge, a DC corona discharge and an atmospheric pressure plasma jet are generated above water, the off-gas of a packed-bed dielectric barrier discharge (PB-DBD) is sparged into water, and then reactive oxygen species and reactive nitrogen species in the water are investigated. H2O2, NO3- and a trace of NO2- are produced in the water after the plasma exposure. H2O2 concentration decreases when NO3- concentration increases, so that this is likely that OH radical to produce H2O2 by OH + OH -->H2O2 is consumed in the NO3- production by NO2 + OH --> HNO3 --> NO3-+ H+ (in water). Since no species is detected in water by the sparging of the PB-DBD off-gas containing more than 1000 ppm of O3, O3 does not contribute to produce H2O2 in water. Further, only NO3- is produced by the sparging of the off-gas containing N2O5 and HNO3. This leads that H2O2 and NO2- can be produced by short-lifetime species in plasma. In this work, the highest generation efficiency of H2O2 and NO2- are respectively 3,820 μg/Wh and 830 μg/Wh by the pulsed-plasma exposure, and that of NO3- is 2,530 μg/Wh by the off-gas sparging of the PB-DBD.

  2. A Particular River-Whiting Phenomenon Caused by Discharge of Hypolimnetic Water from a Stratified Reservoir

    PubMed Central

    Chen, Jingan; Yang, Haiquan; Zhang, David Dian; Xu, Dan; Luo, Jing; Wang, Jingfu

    2015-01-01

    A particular river-whiting phenomenon occurred in the early 2000s in the Xiaoche River and since then it has been reoccurring from June to November each year. Residents were surprised by this phenomenon and worried about it. This study was designed to reveal the forming mechanism of the river-whiting phenomenon. A comparison of T, EC, ORP, DO, TDS and δ34S in the culvert water and discharge pipe water with that in the water column of Aha Reservoir strongly indicated that the culvert water and discharge pipe water derived primarily from the hypolimnetic reservoir water. When the hypolimnetic water enriched in SO42- and H2S, through seepage from the penstock, flows into the Xiaoche River, the water's supersaturation degree with respect to CaSO4 is increased as a result of increased temperature and DO, thus colloid CaSO4 can be formed. This is the essential cause of the river-whiting phenomenon. The sources of high concentrations of SO42- and H2S in hypolimnetic water include not only direct SO42- and H2S input of acid mine drainage as a result of irrational coal mining in the watershed, but also the sulfur-enriched surface sediments which may release H2S through the sulfate reduction processes. The contaminated sediment has acted as an important contamination source for sulfur to the overlying water in Aha Reservoir. There are more than 50,000 large dams in the world until now. With the increase of reservoir age and the persistent accumulation of pollutants within the reservoir system, discharged hypolimnetic water may contain high levels of pollutants and lead to unpredicted disasters. More investigations are needed to illuminate the water quality condition of discharge water from reservoirs and estimate its impacts on the downstream eco-environment. PMID:26361219

  3. A Particular River-Whiting Phenomenon Caused by Discharge of Hypolimnetic Water from a Stratified Reservoir.

    PubMed

    Chen, Jingan; Yang, Haiquan; Zhang, David Dian; Xu, Dan; Luo, Jing; Wang, Jingfu

    2015-01-01

    A particular river-whiting phenomenon occurred in the early 2000s in the Xiaoche River and since then it has been reoccurring from June to November each year. Residents were surprised by this phenomenon and worried about it. This study was designed to reveal the forming mechanism of the river-whiting phenomenon. A comparison of T, EC, ORP, DO, TDS and δ34S in the culvert water and discharge pipe water with that in the water column of Aha Reservoir strongly indicated that the culvert water and discharge pipe water derived primarily from the hypolimnetic reservoir water. When the hypolimnetic water enriched in SO42- and H2S, through seepage from the penstock, flows into the Xiaoche River, the water's supersaturation degree with respect to CaSO4 is increased as a result of increased temperature and DO, thus colloid CaSO4 can be formed. This is the essential cause of the river-whiting phenomenon. The sources of high concentrations of SO42- and H2S in hypolimnetic water include not only direct SO42- and H2S input of acid mine drainage as a result of irrational coal mining in the watershed, but also the sulfur-enriched surface sediments which may release H2S through the sulfate reduction processes. The contaminated sediment has acted as an important contamination source for sulfur to the overlying water in Aha Reservoir. There are more than 50,000 large dams in the world until now. With the increase of reservoir age and the persistent accumulation of pollutants within the reservoir system, discharged hypolimnetic water may contain high levels of pollutants and lead to unpredicted disasters. More investigations are needed to illuminate the water quality condition of discharge water from reservoirs and estimate its impacts on the downstream eco-environment. PMID:26361219

  4. Risk assessment for produced water discharges to Louisiana Open Bays

    SciTech Connect

    Meinhold, A.F.; DePhillips, M.P.; Holtzman, S.

    1995-06-23

    Data were collected prior to termination of discharge at three sites (including two open bay sites at Delacroix Island and Bay De Chene) for the risk assessments. The Delacroix Island Oil and Gas Field has been in production since the first well drilling in 1940; the Bay De Chene Field, since 1942. Concentrations of 226Ra, 228Ra, 210Po, and 228Th were measured in discharges. Radium conc. were measured in fish and shellfish tissues. Sediment PAH and metal conc. were also available. Benthos sampling was conducted. A survey of fishermen was conducted. The tiered risk assessment showed that human health risks from radium in produced water appear to be small; ecological risk from radium and other radionuclides in produced water also appear small. Many of the chemical contaminants discharged to open Louisiana bays appear to present little human health or ecological risk. A conservative screening analysis suggested potential risks to human health from Hg and Pb and a potential risk to ecological receptors from total effluent, Sb, Cd, Cu, Pb, Ni, Ag, Zn, and phenol in the water column and PAHs in sediment; quantitiative risk assessments are being done for these contaminants.

  5. Fuzzy Neural Networks for water level and discharge forecasting

    NASA Astrophysics Data System (ADS)

    Alvisi, Stefano; Franchini, Marco

    2010-05-01

    A new procedure for water level (or discharge) forecasting under uncertainty using artificial neural networks is proposed: uncertainty is expressed in the form of a fuzzy number. For this purpose, the parameters of the neural network, namely, the weights and biases, are represented by fuzzy numbers rather than crisp numbers. Through the application of the extension principle, the fuzzy number representative of the output variable (water level or discharge) is then calculated at each time step on the basis of a set of crisp inputs and fuzzy parameters of the neural network. The proposed neural network thus allows uncertainty to be taken into account at the forecasting stage not providing only deterministic or crisp predictions, but rather predictions in terms of 'the discharge (or level) will fall between two values, indicated according to the level of credibility considered, whereas it will take on a certain value when the level of credibility is maximum'. The fuzzy parameters of the neural network are estimated using a calibration procedure that imposes a constraint whereby for an assigned h-level the envelope of the corresponding intervals representing the outputs (forecasted levels or discharges, calculated at different points in time) must include a prefixed percentage of observed values. The proposed model is applied to two different case studies. Specifically, the data related to the first case study are used to develop and test a flood event-based water level forecasting model, whereas the data related to the latter are used for continuous discharge forecasting. The results obtained are compared with those provided by other data-driven models - Bayesian neural networks (Neal, R.M. 1992, Bayesian training of backpropagation networks by the hybrid Monte Carlo method. Tech. Rep. CRG-TR-92-1, Dep. of Comput. Sci., Univ. of Toronto, Toronto, Ont., Canada.) and the Local Uncertainty Estimation Model (Shrestha D.L. and Solomatine D.P. 2006, Machine learning

  6. Investigation of properties of coal-water slurries produced by electric discharge methods

    NASA Astrophysics Data System (ADS)

    Buyantuev, S.; Khmelev, A.; Kondratenko, A.; Baldynova, F.

    2015-11-01

    The purpose of research is to obtain high quality coal-water slurry with minimum energy consumption. The paper presents the characteristics of coal-water slurries produced by electric discharge methods. The raw material is coal from different mines (Tugnuisky, Aduun- Chulunsky, etc.). Micrographs of the surface of the coal particles in the slurry and its chemical composition are obtained by scanning electron microscopy. Micrographs showed that the electric discharge treatment resulted in a significant dispersion of the coal particles. Elemental analysis showed a significant reduction of oxides of sulfur and nitrogen. Viscosity of slurries was determined by Brookfield rotational viscometer and corresponds to the standard of GB / T18856.4.

  7. Disintegration of rocks based on magnetically isolated high voltage discharge

    NASA Astrophysics Data System (ADS)

    He, Mengbing; Jiang, Jinbo; Huang, Guoliang; Liu, Jun; Li, Chengzu

    2013-02-01

    Recently, a method utilizing pulsed power technology for disintegration of rocks arouses great interest of many researchers. In this paper, an improved method based on magnetic switch and the results shown that the uniform dielectrics like plastic can be broken down in water is presented, and the feasible mechanism explaining the breakdown of solid is proposed and proved experimentally. A high voltage pulse of 120 kV, rise time 0.2 μs was used to ignite the discharging channel in solids. When the plasma channel is formed in the solid, the resistance of the channel is quiet small; even if a relatively low voltage is applied on the channel on this occasion, it will produce high current to heat the plasma channel rapidly, and eventually disintegrate the solids. The feasibility of promising industrial application in the drilling and demolition of natural and artificial solid materials by the method we presented is verified by the experiment result in the paper.

  8. [Desulphurization with multi-needle-water film electrodes by corona discharge].

    PubMed

    Huang, Xu-ran; Li, Guo-feng; Li, Jie; Wu, Yan

    2008-09-01

    The study of this paper adopted stainless steel multi-needle as a high voltage electrode system, and water film as low voltage electrode. The electrodes were supplied with negative DC high voltage. Polluted gas containing sulfur dioxide (SO2) flowed into the corona discharge field from the center of the high voltage electrode system in an axis direction, then get across the water surface. Under the effect of corona discharge plasma and water absorption, SO2 was removed by converting it into sulfuric acid. The effect of the three factors which were the applied voltage, SO2 inlet concentration and duration of the exposure to the corona discharge on desulphurization efficiency has been studied mostly. Moreover, the concentrations of SO3(2-) and SO4(2-) ions in the water were measured and the mechanism of desulphurization was analyzed. The results showed that there was a synergistic effect on the removal of SO2 when combining corona discharge and water absorption, and both the desulphurization efficiency and the amount of sulfuric acid increased evidently. As the applied voltage and the duration increased, the desulphurization efficiency increased. Also, the SO2 inlet concentration had effect on desulphurization efficiency. When the SO2 inlet concentration was 430 x 10(-6), the voltage was 14.5 kV and the duration was 7.5 s, a desulphurization efficiency of more than 90% could be attained. PMID:19068659

  9. High-speed imaging system for observation of discharge phenomena

    NASA Astrophysics Data System (ADS)

    Tanabe, R.; Kusano, H.; Ito, Y.

    2008-11-01

    A thin metal electrode tip instantly changes its shape into a sphere or a needlelike shape in a single electrical discharge of high current. These changes occur within several hundred microseconds. To observe these high-speed phenomena in a single discharge, an imaging system using a high-speed video camera and a high repetition rate pulse laser was constructed. A nanosecond laser, the wavelength of which was 532 nm, was used as the illuminating source of a newly developed high-speed video camera, HPV-1. The time resolution of our system was determined by the laser pulse width and was about 80 nanoseconds. The system can take one hundred pictures at 16- or 64-microsecond intervals in a single discharge event. A band-pass filter at 532 nm was placed in front of the camera to block the emission of the discharge arc at other wavelengths. Therefore, clear images of the electrode were recorded even during the discharge. If the laser was not used, only images of plasma during discharge and thermal radiation from the electrode after discharge were observed. These results demonstrate that the combination of a high repetition rate and a short pulse laser with a high speed video camera provides a unique and powerful method for high speed imaging.

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

    SciTech Connect

    Not Available

    1992-12-01

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

  11. Electrodeless discharge lamp is easily started, has high stability

    NASA Technical Reports Server (NTRS)

    Bell, W. E.; Bloom, A. L.

    1966-01-01

    Electrodeless discharge borosilicate glass lamp is used in various high-resolution optical systems. It is partially charged with krypton, contains small amounts of rubidium, and is enclosed in a hermetically sealed envelope that maintains the lamp at an optimum temperature during discharge. The lamp is quickly started by its excitation coil.

  12. Approaches to setting organism-based ballast water discharge standards.

    PubMed

    Henry, Lee; Reusser, Deborah A; Frazier, Melanie

    2013-03-01

    As a vector by which foreign species invade coastal and freshwater waterbodies, ballast water discharge from ships is recognized as a major environmental threat. The International Maritime Organization (IMO) drafted an international treaty establishing ballast water discharge standards based on the number of viable organisms per volume of ballast discharge for different organism size classes. Concerns that the IMO standards are not sufficiently protective have initiated several state and national efforts in the United States to develop more stringent standards. We evaluated seven approaches to establishing discharge standards for the > 50-microm size class: (1) expert opinion/management consensus, (2) zero detectable living organisms, (3) natural invasion rates, (4) reaction-diffusion models, (5) population viability analysis (PVA) models, (6) per capita invasion probabilities (PCIP), and (7) experimental studies. Because of the difficulty in synthesizing scientific knowledge in an unbiased and transparent fashion, we recommend the use of quantitative models instead of expert opinion. The actual organism concentration associated with a "zero detectable organisms" standard is defined by the statistical rigor of its monitoring program; thus it is not clear whether such a standard is as stringent as other standards. For several reasons, the natural invasion rate, reaction-diffusion, and experimental approaches are not considered suitable for generating discharge standards. PVA models can be used to predict the likelihood of establishment of introduced species but are limited by a lack of population vital rates for species characteristic of ballast water discharges. Until such rates become available, PVA models are better suited to evaluate relative efficiency of proposed standards rather than predicting probabilities of invasion. The PCIP approach, which is based on historical invasion rates at a regional scale, appears to circumvent many of the indicated problems

  13. Approaches to setting organism-based ballast water discharge standards

    USGS Publications Warehouse

    Lee, Henry, II; Reusser, Deborah A.; Frazier, Melanie

    2013-01-01

    As a vector by which foreign species invade coastal and freshwater waterbodies, ballast water discharge from ships is recognized as a major environmental threat. The International Maritime Organization (IMO) drafted an international treaty establishing ballast water discharge standards based on the number of viable organisms per volume of ballast discharge for different organism size classes. Concerns that the IMO standards are not sufficiently protective have initiated several state and national efforts in the United States to develop more stringent standards. We evaluated seven approaches to establishing discharge standards for the >50-μm size class: (1) expert opinion/management consensus, (2) zero detectable living organisms, (3) natural invasion rates, (4) reaction–diffusion models, (5) population viability analysis (PVA) models, (6) per capita invasion probabilities (PCIP), and (7) experimental studies. Because of the difficulty in synthesizing scientific knowledge in an unbiased and transparent fashion, we recommend the use of quantitative models instead of expert opinion. The actual organism concentration associated with a “zero detectable organisms” standard is defined by the statistical rigor of its monitoring program; thus it is not clear whether such a standard is as stringent as other standards. For several reasons, the natural invasion rate, reaction–diffusion, and experimental approaches are not considered suitable for generating discharge standards. PVA models can be used to predict the likelihood of establishment of introduced species but are limited by a lack of population vital rates for species characteristic of ballast water discharges. Until such rates become available, PVA models are better suited to evaluate relative efficiency of proposed standards rather than predicting probabilities of invasion. The PCIP approach, which is based on historical invasion rates at a regional scale, appears to circumvent many of the indicated problems

  14. Ground water discharge and the related nutrient and trace metal fluxes into Quincy bay, Massachusetts.

    PubMed

    Poppe, L J; Moffett, A M

    1993-03-01

    Measurement of the rate and direction of ground water flow beneath Wollaston Beach, Quincy, Massachusetts by use of a heat-pulsing flowmeter shows a mean velocity in the bulk sediment of 40 cm d(-1). The estimated total discharge of ground water into Quincy Bay during October 1990 was 1324-2177 m(3) d(-1), a relatively low ground water discharge rate. The tides have only a moderate effect on the rate and direction of this flow. Other important controls on the rate and volume of ground water flow are the limited thickness, geographic extent, and permeability of the aquifer. Comparisons of published streamflow data and estimates of ground water discharge indicate that ground water makes up between 7.4-12.1% of the gaged freshwater input into Quincy Bay. The data from this study suggest the ground water discharge is a less important recharge component to Quincy Bay than predicted by National Urban Runoff Program (NURP) models.The high nitrate and low nitrite and ammonia concentrations in the ground water at the backshore well sites and low nitrate and high nitrite and ammonia concentrations in the water flowing from the foreshore suggests that denitrification is active in the sediments. The low ground water flow rates and low nitrate concentrations in the foreshore samples suggest that little or no nitrate is surviving the denitrification process to affect the planktonic community. Similarly, oxidizing conditions in the aquifer and low trace metal concentrations in the ground water samples suggest that the metals may be precipitating and binding to sedimentary phases before impacting the bay. PMID:24227453

  15. Discharging Through an Orifice Determines Steam-Water Enthalpy

    SciTech Connect

    James, Russell

    1987-01-20

    A wide range of steam-water mixtures was discharged to the atmosphere through a 10.7 mm diameter orifice which was sharp-edged with a minuscule throat pressure tapping. The ratio of throat pressure to up-stream pressure was found sensitive to dryness fraction over the whole range studied from 0.03 to 1.0. The technique (employing large orifices) has the potential of identifying the unknown enthalpy of geothermal wells discharging large flows. Contrariwise, a nozzle (rounded entry orifice) was found remarkably _insensitive_ over most of the dryness range and hence is useless for such determinations; however, it can be used to measure the flow-rate when enthalpy is known. 2 figs., 7 refs.

  16. Groundwater and surface water discharge from an abandoned tailings impoundment: Implications for watershed water quality

    NASA Astrophysics Data System (ADS)

    Moncur, M. C.; Ptacek, C. J.; Blowes, D. W.; Birks, S. J.

    2006-12-01

    Release of acid drainage from mine-waste disposal areas is a problem of international scale. Drainage from sulfide-rich waste can result in contaminated surface waters, directly through surface runoff and indirectly, from discharge of contaminated groundwater flow. Camp Lake, located in Northern Manitoba, receives both direct and indirect drainage from an abandoned tailings impoundment, which has severely affected the quality of the downstream watershed. Nearly a century of sulfide oxidation at this mine site has resulted in extremely high concentrations of oxidation products in the surface water and groundwater discharging from the two tailings impoundments, both of which flow into an adjacent semi-isolated shallow bay in Camp Lake. The incorporation of these aqueous effluents has altered the composition of the lake water, which in turn has modified the physical limnology of the lake. The various sources of water and solutes to the lake (surface inflows, perched water table, primary water table) contribute varying concentrations of metals to the overall contaminant loadings to the lake, and can be characterized by distinct 3H, δ18O, and δ2H compositions. Geochemical profiles of the water column indicate that, despite its shallow depth (6 m), the bay is stratified throughout the year. The greatest accumulation of dissolved metals and SO4 is in the lower portion of the water column, with concentrations up to 8500 mg/L Fe, 20,000 mg/L SO4, 30 mg/L Zn, and 100 mg/L Al, including elevated concentrations of Cu, Cd, Pb, and Ni. This stratification is mirrored in the δ18O, δ2H and d-excess profiles within the lake water column, with an evaporatively enriched surface layer overlying the isotopically lighter, higher d-excess hypolimnion. Despite meromictic conditions and very high solute concentrations being limited to the semi-isolated bay, the annual loadings of acid, sulfate, and metals from Camp Lake to the adjacent lake are extremely large, and fluctuate seasonally

  17. Complex utilization of snf processing wastes in air plasma of high-frequency torch discharge

    NASA Astrophysics Data System (ADS)

    Karengin, A. G.; Karengin, A. A.; Podgornaya, O. D.; Shlotgauer, E. E.

    2014-10-01

    We present results of complex spent nuclear fuel wastes utilization process in air plasma of high-frequency torch discharge in form of dispersed water-organic compositions. We demonstrate the possibility to apply magnetic separation for effective extraction of obtained dispersed solid products including magnetic iron oxide from water suspension.

  18. Monitoring Environmental Recovery at Terminated Produced Water Discharge Sites in Coastal Louisiana Waters

    SciTech Connect

    Continental Shelf Associates, Inc.

    1999-08-16

    This report presents the results of a study of terminated produced water discharge sites in the coastal waters of Louisiana. Environmental recovery at the sites is documented by comparing pre-termination and post-termination (six months and one year) data. Produced water, sediments, and sediment interstitial water samples were analyzed for radionuclides, metals, and hydrocarbons. Benthic infauna were identified from samples collected in the vicinity of the discharge and reference sites. Radium isotope activities were determined in fish and crustacean samples. In addition, an environmental risk assessment is made on the basis of the concentrations of metals and hydrocarbons determined in the samples.

  19. Drainage water management effects on tile discharge and water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen (N) fluxes from tile drained watersheds have been implicated in water quality studies of the Mississippi River Basin, but the contribution of tile drains to N export in headwater watersheds is not well understood. The objective of this study was to ascertain seasonal and annual contribution...

  20. Plasma Discharges in Gas Bubbles in Liquid Water: Breakdown Mechanisms and Resultant Chemistry

    NASA Astrophysics Data System (ADS)

    Gucker, Sarah M. N.

    The use of atmospheric pressure plasmas in gases and liquids for purification of liquids has been investigated by numerous researchers, and is highly attractive due to their strong potential as a disinfectant and sterilizer. However, the fundamental understanding of plasma production in liquid water is still limited. Despite the decades of study dedicated to electrical discharges in liquids, many physical aspects of liquids, such as the high inhomogeneity of liquids, complicate analyses. For example, the complex nonlinearities of the fluid have intricate effects on the electric field of the propagating streamer. Additionally, the liquid material itself can vaporize, leading to discontinuous liquid-vapor boundaries. Both can and do often lead to notable hydrodynamic effects. The chemistry of these high voltage discharges on liquid media can have circular effects, with the produced species having influence on future discharges. Two notable examples include an increase in liquid conductivity via charged species production, which affects the discharge. A second, more complicated scenario seen in some liquids (such as water) is the doubling or tripling of molecular density for a few molecule layers around a high voltage electrode. These complexities require technological advancements in optical diagnostics that have only recently come into being. This dissertation investigates several aspects of electrical discharges in gas bubbles in liquids. Two primary experimental configurations are investigated: the first allows for single bubble analysis through the use of an acoustic trap. Electrodes may be brought in around the bubble to allow for plasma formation without physically touching the bubble. The second experiment investigates the resulting liquid phase chemistry that is driven by the discharge. This is done through a dielectric barrier discharge with a central high voltage surrounded by a quartz discharge tube with a coil ground electrode on the outside. The plasma

  1. Analytical approach for predicting fresh water discharge in an estuary based on tidal water level observations

    NASA Astrophysics Data System (ADS)

    Cai, H.; Savenije, H. H. G.; Jiang, C.

    2014-06-01

    As the tidal wave propagates into an estuary, the tidally averaged water level tends to rise in landward direction due to the density difference between saline and fresh water and the asymmetry of the friction. The effect of friction on the residual slope is even more remarkable when accounting for fresh water discharge. In this study, we investigate the influence of river discharge on tidal wave propagation in the Yangtze estuary with specific attention to residual water level slope. This is done by using a one-dimensional analytical model for tidal hydrodynamics accounting for the residual water level. We demonstrate the importance of the residual slope on tidal dynamics and use it to improve the prediction of the tidal propagation in estuaries (i.e., tidal damping, velocity amplitude, wave celerity and phase lag), especially when the influence of river discharge is significant. Finally, we develop a new inverse analytical approach for estimating fresh water discharge on the basis of tidal water level observations along the estuary, which can be used as a tool to obtain information on the river discharge that is otherwise difficult to measure in the tidal region.

  2. Analytical approach for predicting fresh water discharge in an estuary based on tidal water level observations

    NASA Astrophysics Data System (ADS)

    Cai, H.; Savenije, H. H. G.; Jiang, C.

    2014-10-01

    As the tidal wave propagates into an estuary, the tidally averaged water level tends to rise in landward direction due to the density difference between saline and fresh water and the asymmetry of the friction. The effect of friction on the residual slope is even more remarkable when accounting for fresh water discharge. In this study, we investigate the influence of river discharge on tidal wave propagation in the Yangtze estuary with specific attention to residual water level slope. This is done by using a one-dimensional analytical model for tidal hydrodynamics accounting for the residual water level. We demonstrate the importance of the residual slope on tidal dynamics and use it to improve the prediction of the tidal propagation in estuaries (i.e. tidal damping, velocity amplitude, wave celerity and phase lag), especially when the influence of river discharge is significant. Finally, we develop a new inverse analytical approach for estimating fresh water discharge on the basis of tidal water level observations along the estuary, which can be used as a tool to obtain information on the river discharge that is otherwise difficult to measure in the tidal region.

  3. Insulator damage in high current discharges

    NASA Astrophysics Data System (ADS)

    Ranon, P. M.; Kristiansen, M.; Lehr, F. M.; Hatfield, L. L.

    1986-11-01

    The degradation of the hold-off voltage capability of several composite candidates for railgun insulators was studied experimentally. The materials examined were BN, alumina (Coor's ceramic), and two types of laminated fiberglass/epoxy (FGE I and FGE II). Sample 1 cm thick plates of the insulators were inserted into a surface discharge switch (SDS) with a gap of 1.6 in., i.e., an initial hold-off voltage of 40 kV. FGE I retained the hold-off voltage for more than 10,000 shots at a current of 1 kA maximum, but degraded significantly after 50 shots at currents over 200 kA. BN shattered when the repetition rate exceeded 1 pulse/sec.

  4. Partial discharge in a high voltage experimental test assembly

    SciTech Connect

    Koss, R.J.; Brainard, J.P.

    1998-07-01

    This study was initiated when a new type of breakdown occurred in a high voltage experimental test assembly. An anomalous current pulse was observed, which indicated partial discharges, some leading to total breakdowns. High voltage insulator defects are shown along with their effect on the electrostatic fields in the breakdown region. OPERA electromagnetic field modeling software is used to calculate the fields and present a cause for the discharge. Several design modifications are investigated and one of the simplest resulted in a 25% decrease in the field at the discharge surface.

  5. High ozone values near ground caused by silent discharge

    NASA Astrophysics Data System (ADS)

    Duetsch, H. U.; Graber, W.; Wyss, A.

    Continuous ozone monitoring near the top of a 120 m high idle smoke stack had shown a very frequent occurrence of mixing ratios suggesting air of stratospheric origin. In order to investigate whether these events could instead have been due to ozone production by silent discharge in the locally very strong electric field, an experiment was designed which measured point discharge current close to the intake and ozone at the same level using an electrically shielded intake. This second sensor did not show the high ozone values of the first and there was a high correlation between point discharge current above a certain threshold and unusual ozone peaks. Silent discharge was thus in almost all the cases responsible for the high ozone peaks at this site.

  6. Discharge characteristics of a high speed fuel injection system

    NASA Technical Reports Server (NTRS)

    Matthews, Robertson

    1925-01-01

    Discussed here are some discharge characteristics of a fuel injection system intended primarily for high speed service. The system consisted of a cam actuated fuel pump, a spring loaded automatic injection valve, and a connecting tube.

  7. Dynamics of laser-guided alternating current high voltage discharges

    NASA Astrophysics Data System (ADS)

    Daigle, J.-F.; Théberge, F.; Lassonde, P.; Kieffer, J.-C.; Fujii, T.; Fortin, J.; Châteauneuf, M.; Dubois, J.

    2013-10-01

    The dynamics of laser-guided alternating current high voltage discharges are characterized using a streak camera. Laser filaments were used to trigger and guide the discharges produced by a commercial Tesla coil. The streaking images revealed that the dynamics of the guided alternating current high voltage corona are different from that of a direct current source. The measured effective corona velocity and the absence of leader streamers confirmed that it evolves in a pure leader regime.

  8. Subsurface storage of freshwater in south Florida; evaluation of surface-water discharge data at selected sites

    USGS Publications Warehouse

    Sonntag, W.H.

    1984-01-01

    Canal discharge in south Florida may consist of a potential source of freshwater for deep-well injection. Discharge data for the 1970-81 water years at 27 canal and river sites were analyzed. Flow was analyzed for 30-, 60-, 90-, 120-, and 183-consecutive-day low-mean discharges during the periods of highest flow to define minimum high-flow-period fresh surface-water discharges at the 27 sites. Curves show the magnitude and frequency of average minimum flows for consecutive-day periods during high-flow periods, and duration curves and tables show the percentage of time that selected discharges were equaled or exceeded. Canal discharge as high as 660 cubic feet per second occurred 70 percent of the time during the high-flow period at one site (Tamiami Canal Outlets, Levee 67A to 40-Mile Bend). At 11 sites, discharges of 110 to 370 cubic feet per second occurred 70 percent of the high-flow periods, while at 9 sites, discharges of 21 to 100 cubic feet per second occurred 70 percent of the time during the high-flow periods. At other sites (those in the Biscayne, Plantation Road, Middle River, C-111, and Cypress Creek Canals), discharges as low as 0.1 cubic foot per second occurred 70 percent of the time during the high-flow periods. Criteria for amounts of surplus freshwater considered adequate to support injection systems cannot be established, as they would vary greatly with water needs to be satisfied and with the efficiency of a particular injection system. However, based upon this analysis of discharge at 27 canal and river sites throughout south Florida, it appears that substantial amounts of water are available for surface injection and storage. (USGS)

  9. The Time Evolution of Streamer Discharges in Single and Multiple Bubbles in Water

    NASA Astrophysics Data System (ADS)

    Mujovic, Selman; Groele, Joseph; Foster, John

    2015-09-01

    The interaction of plasma with liquid water lies at the heart of a variety of revisited technological applications ranging from water treatment to wound healing. Plasma ignition and propagation in water, however, is poorly understood. It has been theorized that plasma streamer propagation takes place in microbubbles, namely streamer bubble hopping. In this work, discharge development in single and multiple bubble acoustic systems is investigated using high-speed imaging and emission spectroscopy. Optical filters allow for time resolved measurements of specific chemical species as well. Better understanding of these breakdown processes will guide the construction of an effective plasma water purifier. NSF CBET 1336375.

  10. Estimated ground-water discharge by evapotranspiration from Death Valley, California, 1997-2001

    USGS Publications Warehouse

    DeMeo, Guy A.; Laczniak, Randell J.; Boyd, Robert A.; Smith, J. LaRue; Nylund, Walter E.

    2003-01-01

    The U.S. Geological Survey, in cooperation with the National Park Service and Inyo County, Calif., collected field data from 1997 through 2001 to accurately estimate the amount of annual ground-water discharge by evapotranspiration (ET) from the floor of Death Valley, California. Multispectral satellite-imagery and National Wetlands Inventory data are used to delineate evaporative ground-water discharge areas on the Death Valley floor. These areas are divided into five general units where ground-water discharge from ET is considered to be significant. Based upon similarities in soil type, soil moisture, vegetation type, and vegetation density; the ET units are salt-encrusted playa (21,287 acres), bare-soil playa (75,922 acres), low-density vegetation (6,625 acres), moderate-density vegetation (5,019 acres), and high-density vegetation (1,522 acres). Annual ET was computed for ET units with micrometeorological data which were continuously measured at six instrumented sites. Total ET was determined at sites that were chosen for their soil- and vegetated-surface conditions, which include salt-encrusted playa (extensive salt encrustation) 0.17 feet per year, bare-soil playa (silt and salt encrustation) 0.21 feet per year, pickleweed (pickleweed plants, low-density vegetation) 0.60 feet per year, Eagle Borax (arrowweed plants and salt grass, moderate-density vegetation) 1.99 feet per year, Mesquite Flat (mesquite trees, high-density vegetation) 2.86 feet per year, and Mesquite Flat mixed grasses (mixed meadow grasses, high-density vegetation) 3.90 feet per year. Precipitation, flooding, and ground-water discharge satisfy ET demand in Death Valley. Ground-water discharge is estimated by deducting local precipitation and flooding from cumulative ET estimates. Discharge rates from ET units were not estimated directly because the range of vegetation units far exceeded the five specific vegetation units that were measured. The rate of annual ground-water discharge by ET for

  11. Zero-discharge: An application of process water recovery technology in the food processing industry

    SciTech Connect

    Fok, S.; Moore, B.

    1999-07-01

    Water is a valuable natural resource and the food processing industry has been among the leading industrial water users in California. With support from a major northern California utility and the California Institute for Food and Agricultural Research, Tri Valley Growers (TVG) has successfully installed the first US energy-efficient zero-discharge process water reclamation system at its Oberti Olive processing facility in Madera, California. The advanced zero-discharge system is the largest application in the world of membrane filtration for recovering water from a food processing plant. Previously, the plant discharged an average of 1 million gallons of salty wastewater (brine) a day into 160 acres of evaporation ponds. However, new environmental regulations made the ponds obsolete. The cost of process water disposal using alternate biotreatment system was prohibitive and would make continued operation uneconomical with plant closure and job loss the likely outcome. Through comprehensive pilot testing and subsequent system design and operational optimization, the advance membrane filtration system with pre- and post-treatment now recovers about 80% of the process liquid in high priority form of water for subsequent reuse at the plant. The solids produced in olive processing, plus concentrated process liquids are used off-site as an animal feed component, thus achieving the plant zero-discharge scheme. The successful implementation of the zero discharge system at the Oberti Olive processing plant has produced energy saving of 3,500,000 kilowatthours and 244,000 therms of gas a year of power as compared to the alternate biotreatment system. It also prevented plant closure and job loss. In addition, water conservation and the discontinuation of evaporation pond use is beneficial to the environment. The project was applauded by the California Environmental Protection Agency as a positive step forward for environmental technology in the agricultural sector in

  12. Water Treatment using Discharge Generated in Cavitation Field with Micro Bubble Cloud

    NASA Astrophysics Data System (ADS)

    Ihara, Satoshi; Hirohata, Taiki; Kominato, Yuichi; Yamabe, Chobei; Ike, Hideaki; Hakiai, Kazunori; Hirabayashi, Kazuya; Tamagawa, Masaaki

    New method of water treatment for wastewater using discharge in water cavitation field, in which numerous micro bubbles were generated by high-speed water flow, was proposed in this paper. Indigo carmine solution, which is a type of dye, with a concentration of 9mg/Liter was used as a specimen for demonstration of water treatment. The total volume of solution and average speed of solution in the cavitation field was 20 Liter and about 7.4 m/s, respectively. A reduction ratio of absorbance of 96% was obtained in 50 min of treatment time at an electrode distance of 2 mm and a discharge power of 16 W. Also it was found that the efficiency of decolorization was improved by changing the electrode location.

  13. Sterilization of Fungus in Water by Pulsed Power Gas Discharge Reactor Spraying Water Droplets for Water Treatment

    NASA Astrophysics Data System (ADS)

    Saito, Tsukasa; Handa, Taiki; Minamitani, Yasushi

    We study sterilization of bacteria in water using pulsed streamer discharge of gas phase. This method enhances efficiency of water treatment by spraying pretreatment water in a streamer discharge area. In this paper, yeast was sterilized because we assumed a case that fungus like mold existed in wastewater. As a result, colony forming units decreased rapidly for 2 minutes of the processing time, and all yeast sterilized by 45 minutes of the processing time.

  14. OH Radical and a Drizzling Water Jet Production from the Ball-Lightning Discharge in Water

    NASA Astrophysics Data System (ADS)

    Maeyama, Mitsuaki; Tanaka, Yasutomo

    The ball lightning, or fireball discharge using the typical electrode configuration was reported to produce a long-living spherical plasmoid with radius exceed 10 cm at atmospheric pressure. In this study, we investigated the relationship between a optical output emitted from OH radicals and discharge conditions of the ball-lightning electrode configuration, and discussed its possibility to the water treatment process. As a results, in both polarity cases of the charged voltage V0, a ball-lightning discharge and the optical emission from OH radicals as a major radiation can be generated on the condition |V0| > 4 kV in tap water. Furthermore, an intensive upward water jet from the rod electrode is observed in case of positive polarity and in 0.2% NaCl solution, which is composed of drizzling water drops near the rod electrode.

  15. Characteristics of streamer discharge development between the dielectric-coated sphere-plane electrodes in water

    SciTech Connect

    Zhu Taiyun; Yang Lanjun; Jia Zhijie; Zhang Qiaogen

    2008-12-01

    This paper presents the characteristics of the streamer discharge development between the dielectric-coated sphere-plane electrodes in water. In order to study the streamer propagation mechanism, the factors such as polarities, water conductivity, and ambient pressure were taken into consideration. Experimental results demonstrate that the water conductivity and amplitude of applied voltage both have a great influence on mean velocity and brightness of the streamer. When the ambient pressure decreases from 0.1 to 0.0065 MPa, the pressure has little influence on the mean velocities of the streamer in both distilled and tap water for fast streamer. The existence of dielectric coating causes a lower initiation voltage of the streamer for negative polarity than that for positive one. Also, the 10% breakdown voltage (U{sub 10%}) is decreased by 20% under the pressure of 0.0065 MPa than that under the pressure of 0.1 MPa in distilled water, while the U{sub 10%} is almost the same under different pressures in tap water. Based on the analysis of the discharge images and current waveforms as well as the above experimental results, it can be concluded that the streamer propagation is composed of the generation of the microbubbles and the discharge in the bubbles. For subsonic streamer, the generation of the bubbles is more likely a thermal process, whereas for supersonic streamer, the ionization and dissociation of water molecules in high electric field are involved in the bubble generation process.

  16. Estimating water quality using linear mixed models with stream discharge and turbidity

    NASA Astrophysics Data System (ADS)

    Lessels, J. S.; Bishop, T. F. A.

    2013-08-01

    Most water quality monitoring schemes rely on estimation methods as it is often far too expensive to monitor water quality properties continuously. Estimations are used to evaluate management strategies and long term trends. It is critical that the estimation methods provide accurate estimations and an accurate estimate of the associated uncertainty. Currently the most common estimation methods assume observations are sampled using a probabilistic sampling scheme, however this assumption is often not met. This paper evaluated the ability of a linear mixed model to estimate water quality concentration values based on observations collected using non-probabilistic sampling. The linear mixed models were used to predict total phosphorus and total nitrogen observations from two catchments in south east Australia. A comparison between stream discharge and turbidity as predictors is made to investigate the effectiveness of turbidity to estimate water quality. In addition to stream discharge and turbidity, several covariates were derived from stream discharge in an attempt to account for hydrological processes. To compare models and their covariates leave one out event cross validation was performed. Event cross validation evaluated predictions during periods of high stream discharge. The inclusion of temporal auto-correlation component improved the accuracy of all models for total phosphorus and total nitrogen. For both catchments the use of turbidity instead of stream discharge increased the accuracy of predictions by at least 15% for total phosphorus and total nitrogen. However, event based cross validation indicated that a combination of both turbidity and stream discharge based variables provided more accurate predictions, decreasing the event RMSE by 18% for total phosphorus and 24% for total nitrogen. In catchments characterised by long periods of base-flow and short rainfall events the addition of turbidity measurements provide more accurate predictions during base

  17. Micro electrical discharge drilling of tungsten carbide using deionized water

    NASA Astrophysics Data System (ADS)

    Song, Ki Young; Chung, Do Kwan; Park, Min Soo; Chu, Chong Nam

    2009-04-01

    Micro electrical discharge machining (micro EDM) is an effective machining method for cobalt-bonded tungsten carbide (WC-Co); however, this material is susceptible to electrolytic corrosion when deionized water is used as the working fluid with a dc power source for the RC circuit. In this study, a bipolar pulse power source and a triangular electrode were used in order to reduce the electrolytic corrosion phenomenon during micro EDM using an RC discharge circuit. A bipolar pulse power source reduces the positive polarity period of the workpiece by periodically alternating the polarity of the workpiece and electrode and decreases the average gap voltage at the machining gap. Therefore, electrolytic corrosion, which is a type of electrochemical reaction on the positively charged workpiece, is reduced by these electrical conditions. The triangular electrode has a smaller side area as compared with the cylindrical electrode. Since the electrolytic corrosion is an electrochemical reaction between the side of the electrode and the surface of the workpiece, the small side area of the triangular electrode could reduce these reactions. With the aid of the bipolar pulse power source and the triangular electrode, an electrolytic-corrosion-free hole could be machined on the WC-Co workpiece using deionized water.

  18. 77 FR 55417 - Standards for Living Organisms in Ships' Ballast Water Discharged in U.S. Waters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-10

    ... Organisms in Ships' Ballast Water Discharged in U.S. Waters (BWDS) Final Rule (77 FR 35268). The rulemaking... (77 FR 17254). The Coast Guard is now publishing a document to advise the public that we received four...' Ballast Water Discharged in U.S. Waters AGENCY: Coast Guard, DHS. ACTION: Rule; information...

  19. Glow discharge techniques for conditioning high vacuum systems

    SciTech Connect

    Dylla, H.F.

    1988-03-01

    A review is given of glow discharge techniques which are useful for conditioning vacuum vessels for high vacuum applications. Substantial development of glow discharge techniques has been done for the purpose of in-situ conditioning of the large ultrahigh vacuum systems for particle accelerators and magnetic fusion devices. In these applications the glow discharge treatments remove impurities from vessel surfaces in order to minimize particle-induced desorption coefficients. Cleaning mechanisms involve a mixture of sputtering and ion- (or neutral) induced desorption effects depending on the gas mixture (ArO/sub 2/ vs. H/sub 2/) and excitation method (DC, RF, and ECR). The author will review the methodology of glow discharge conditioning, diagnostic measurements provided by residual gas and surface composition analysis, and applications to vessel conditioning and materials processing. 76 refs., 16 figs.

  20. Removal of NO and SO2 in Corona Discharge Plasma Reactor with Water Film

    NASA Astrophysics Data System (ADS)

    He, Yuanji; Dong, Liming; Yang, Jiaxiang

    2004-04-01

    In this paper, a novel type of a corona discharge plasma reactor was designed, which consists of needle-plate-combined electrodes, in which a series of needle electrodes are placed in a glass container filled with flue gas, and a plate electrode is immersed in the water. Based on this model, the removal of NO and SO2 was tested experimentally. In addition, the effect of streamer polarity on the reduction of SO2 and NO was investigated in detail. The experimental results show that the corona wind formed between the high-voltage needle electrode and the water by corona discharge enhances the cleaning efficiency of the flue gas because of the presence of water, and the cleaning efficiency will increase with the increase of applied dc voltage within a definite range. The removal efficiency of SO2 up to 98%, and about 85% of NOx removal under suitable conditions is obtained in our experiments.

  1. Disintegration of rocks based on magnetically isolated high voltage discharge.

    PubMed

    He, Mengbing; Jiang, Jinbo; Huang, Guoliang; Liu, Jun; Li, Chengzu

    2013-02-01

    Recently, a method utilizing pulsed power technology for disintegration of rocks arouses great interest of many researchers. In this paper, an improved method based on magnetic switch and the results shown that the uniform dielectrics like plastic can be broken down in water is presented, and the feasible mechanism explaining the breakdown of solid is proposed and proved experimentally. A high voltage pulse of 120 kV, rise time 0.2 μs was used to ignite the discharging channel in solids. When the plasma channel is formed in the solid, the resistance of the channel is quiet small; even if a relatively low voltage is applied on the channel on this occasion, it will produce high current to heat the plasma channel rapidly, and eventually disintegrate the solids. The feasibility of promising industrial application in the drilling and demolition of natural and artificial solid materials by the method we presented is verified by the experiment result in the paper. PMID:23464235

  2. Hundreds of automatic drip counters reveal infiltration water discharge characteristics in Australian caves

    NASA Astrophysics Data System (ADS)

    Baker, A.; Treble, P. C.; Coleborn, K.; Mahmud, K.; Markowska, M.; Flemons, I.

    2015-12-01

    Quantifying the timing and character of cave drip water discharge is crucial for our understanding of speleothem climate proxies. Since 2010, we have established a long-term, national monitoring program of drip water infiltration onto cave stalagmites using automated Stalagmate© loggers. Five karst regions, from semi-arid to sub-tropical climates, have been instrumented. Over 200 loggers (between 10 and 40 per cave) have collected data on the timing and amount of drip water infiltration, from sites of contrasting limestone geology. Here, we present results demonstrating the timing and characteristics of drip water discharge from 2010 to present. At the semi-arid Cathedral Cave, with a range of depths from 0-40 m, there is a decreasing frequency of recharge events with depth below ground surface. High-intensity, long-duration rainfall events are confirmed to be the primary driver of infiltration events at semi-arid sites, whereas annual rainfall amount is the primary driver at a Mediterranean climate site with high primary porosity. Inter-annual variability in the frequency and relative amount of drip water infiltration is compared to climate forcing variables such as the ENSO and surface temperature. Our cave observatory system helps improve our understanding of the drip water recharge process, drip-water related speleothem proxy records, and provides a baseline monitoring network for diffuse groundwater recharge during a period of climate change.

  3. Meteorological, stream-discharge, and water-quality data for water year 1992 from two basins in Central Nevada

    SciTech Connect

    McKinley, P.W.; Oliver, T.A.

    1995-05-01

    The US Geological Survey, in cooperation with the US Department of Energy, is studying Yucca Mountain, Nevada, as a potential repository for high level nuclear waste. As part of the Yucca Mountain Site Project, the analog recharge study is providing data for the evaluation of recharge to the Yucca Mountain ground-water system given a cooler and wetter climate than currently exists. The current and climatic conditions are favorable to the isolation of radioactive waste. Because waste isolation from the accessible environment for 10,000 years is necessary, climatic change and the potential for increased ground-water recharge need to be considered as part of the characterization of the potential repository. Therefore, two small basins, measuring less than 2 square miles, were studied to determine the volume of precipitation available for recharge to ground water. The semiarid 3-Springs Basin is located to the east of Kawich Peak in the Kawich Range east of Tonopah, Nevada. Stewart Basin is a subalpine drainage basin north of Arc Dome in the Toiyabe Range north of Tonopah, Nevada. The purpose of this publication is to make available the meteorological, stream-discharge, and water-quality data collected during the study. Meteorological data collected include air temperature, soil temperature, solar radiation, and relative humidity. Stream-discharge data were collected from the surface-water outlet of each basin. Water-quality data are chemical analyses of water samples collected from surface- and ground-water sources. Each basin has a meteorological station located in the lower and upper reaches of the basin. Hydrologic records include stream-discharge and water-quality data from the lower meteorological site and water-quality data from springs within the basins.

  4. Electrochemical cell with high discharge/charge rate capability

    DOEpatents

    Redey, Laszlo

    1988-01-01

    A fully charged positive electrode composition for an electrochemical cell includes FeS.sub.2 and NiS.sub.2 in about equal molar amounts along with about 2-20 mole percent of the reaction product Li.sub.2 S. Through selection of appropriate electrolyte compositions, high power output or low operating temperatures can be obtained. The cell includes a substantially constant electrode impedance through most of its charge and discharge range. Exceptionally high discharge rates and overcharge protection are obtainable through use of the inventive electrode composition.

  5. Influence of pulse width on decolorization efficiency of organic dye by discharge inside bubble in water

    NASA Astrophysics Data System (ADS)

    Kawano, S.; Wada, K.; Kakuta, T.; Takaki, K.; Satta, N.; Takahashi, K.

    2013-06-01

    Decolorization of an organic dye by discharge in high conductive water using a pulsed power generator and a discharge reactor was investigated. The discharge reactor consisted of a glass tube and a tungsten wire inserted into the glass tube, which was immersed in the water. Room air was injected into the glass tube to generate bubbles in the water. High voltage pulses were generated by an inductive-energy storage system using semiconductor opening switch (SOS) and by a magnetic pulse compression circuit. Fast recovery diodes were used as SOS diode in the inductive-energy storage system. The pulse width was changed in range from 10 to 1200 ns. The high voltage was applied to the tungsten wire. Indigo carmine was employed as a specimen to evaluate decolorization efficiency. Potassium nitrate was used to adjust the solution conductivity. The dye solution was successfully decolorized at 7 mS/cm conductivity. Energy efficiency for decolorization increased from 0.680 to 55.6 mg/Wh with decreasing the pulse width from 1200 to 10 ns owing to the reduction of ohmic loss.

  6. Density Matters: Review of Approaches to Setting Organism-Based Ballast Water Discharge Standards

    EPA Science Inventory

    As part of their effort to develop national ballast water discharge standards under NPDES permitting, the Office of Water requested that WED scientists identify and review existing approaches to generating organism-based discharge standards for ballast water. Six potential appro...

  7. Emission spectroscopy of a microhollow cathode discharge plasma in helium-water gas mixtures

    SciTech Connect

    Namba, S.; Yamasaki, T.; Hane, Y.; Fukuhara, D.; Kozue, K.; Takiyama, K.

    2011-10-01

    A dc microhollow cathode discharge (MHCD) plasma was generated inflowing helium gas containing water vapor. The cathode hole diameters were 0.3, 0.7, 1.0, and 2.0 mm, each with a length of 2.0 mm. Emission spectroscopy was carried out to investigate the discharge mode and to determine the plasma parameters. For the 0.3-mm cathode, stable MHCDs in an abnormal glow mode existed at pressures up to 100 kPa, whereas for larger diameters, a plasma was not generated at atmospheric pressure. An analysis of the lineshapes relevant to He at 667.8 nm and to H{alpha} at 656.3 nm implied an electron density and gas temperature of 2 x 10{sup 14} cm{sup -3} and 1100 K, respectively, for a 100-kPa discharge in the negative glow region. The dependence of the OH band, and H{alpha} intensities on the discharge current exhibited different behaviors. Specifically, the OH spectrum had a maximum intensity at a certain current, while the H atom intensity kept increasing with the discharge current. This observation implies that a high concentration of OH radicals results in quenching, leading to the production of H atoms via the reaction OH + e{sup -}{yields} O + H + e{sup -}.

  8. Water discharge affects Atlantic salmon Salmo salar smolt production: a 27 year study in the River Orkla, Norway.

    PubMed

    Hvidsten, N A; Diserud, O H; Jensen, A J; Jensås, J G; Johnsen, B O; Ugedal, O

    2015-01-01

    A model that explains 48% of the annual variation in Atlantic salmon Salmo salar smolt production in the River Orkla, Norway, has been established. This variation could be explained by egg deposition, minimum daily discharge during the previous winter and minimum weekly discharge during the summer 3 years before smolt migration. All coefficients in the model were positive, which indicates that more eggs and higher minimum discharge levels during the winter before smolt migration and the summer after hatching benefit smolt production. Hence, when the spawning target of the river is reached, the minimum levels of river discharge, in both winter and summer, are the main bottlenecks for the parr survival, and hence for smolt production. The River Orkla was developed for hydropower production in the early 1980s by the construction of four reservoirs upstream of the river stretch accessible to S. salar. Although no water has been removed from the catchment, the dynamics of water flow has been altered, mainly by increasing discharges during winter and reducing spring floods. In spite of the higher than natural winter discharges, minimum winter discharge is still a determinant of smolt production. Hence, in regulated rivers, the maintenance of discharges to ensure that they are as high as possible during dry periods is an important means of securing high S. salar smolt production. PMID:25418585

  9. ARSENIC CYCLING WITHIN THE WATER COLUMN OF A SMALL LAKE RECEIVING CONTAMINATED GROUND WATER DISCHARGE

    EPA Science Inventory

    The fate of arsenic discharged from contaminated ground water to a small, shallow lake at a hazardous waste site is controlled, in part, by the rate of ferrous iron oxidation-precipitation and arsenic sorption occurring near the lake chemocline. Laboratory experiments were condu...

  10. Fate and effects of produced water discharges in nearshore marine water

    SciTech Connect

    Not Available

    1989-01-01

    The report details the results of studies of chemical and physical properties of the sediments around four platforms in the Gulf of Mexico, with intensive study of two of the areas, and comparison with the produced water discharges from the platforms.

  11. Delineation of biological impact and recovery of selected produced water discharges in inshore Louisiana

    SciTech Connect

    Mulino, M.M.; Rayle, M.F.; Francis, J.C.

    1995-12-01

    The benthos data presented are the results of sampling areas around the Delacroix Island Tank Battery No. 1 produced water discharge prior to and after termination. Data show recovery of the numbers of species and individuals at the discharge site six months after the termination of the discharge.

  12. High-beta discharges in the DIII-D tokamak

    SciTech Connect

    Ferron, J.R.; Chu, M.S.; Helton, F.J.; Howl, W.; Kellman, A.G.; Lao, L.L.; Lazarus, E.A.; Lee, J.K.; Osborne, T.H.; Strait, E.J.; Taylor, T.S.; Turnbull, A.D. )

    1990-06-01

    Low-{ital q} ({ital q}{sub 95}{lt}3) double-null divertor discharges with values of the volume-average toroidal beta as high as 9.3% have been operated in the DIII-D tokamak (Fusion Technol. {bold 8}, 441 (1985)). In discharges with {ital q}{sub 95}{approx}5, values of {beta}{sub {ital T}}/({ital I}/{ital aB}) as high as 5 have been obtained. These discharges are shown to be at or below the stability limit to the value of beta for infinite-{ital n}, ideal ballooning modes. The discharges are significantly below the beta limit for ideal,low toroidal mode number kink modes. The kink mode beta limit is shown to be strongly dependent on the radial profiles of plasma pressure and current. The theoretical beta limit in DIII-D is shown to be in the range {beta}{sub {ital T}}/({ital I}/{ital aB})=4 --5 depending on the value of {ital I}/{ital aB}, and this is consistent with the experiment. High-beta discharges have been operated with ion temperature up to 17 keV. Steady-state, high-beta, low-{ital q} operation is demonstrated by a discharge with {ital I}/{ital aB}=2.6, {ital q}{sub 95}=2.7, in which {beta}{sub {ital T}}{gt}7% is maintained for 1.5 sec.

  13. Obtaining molecular hydrogen in electric discharge of the tornado type in air mixture with ethanol and water vapors

    NASA Astrophysics Data System (ADS)

    Levko, D. S.; Shchedrin, A. I.; Chernyak, V. Ya.; Ol'Shevskiĭ, S. V.; Nedybalyuk, O. A.

    2010-11-01

    A new plasmachemical reactor is proposed that provides a high yield of hydrogen from electric discharge in a mixture of air with ethanol and water vapors. It is shown that intense electron-molecule reactions and high temperature in the discharge region favor an increase in the degree of H2O and C2H5OH conversion into molecular hydrogen. A mechanism of the initiation of chain reactions leading to H2 formation is determined. It is established that H2 concentration reaches saturation in the region of discharge currents above 200 mA.

  14. Cathode degradation and erosion in high pressure arc discharges

    NASA Technical Reports Server (NTRS)

    Hardy, T. L.; Nakanishi, S.

    1984-01-01

    The various processes which control cathode erosion and degradation were identified and evaluated. A direct current arc discharge was established between electrodes in a pressure-controlled gas flow environment. The cathode holder was designed for easy testing of various cathode materials. The anode was a water cooled copper collector electrode. The arc was powered by a dc power supply with current and voltage regulated cross-over control. Nitrogen and argon were used as propellants and the materials used were two percent thoriated tungsten, barium oxide impregnated porous tungsten, pure tungsten and lanthanum hexaboride. The configurations used were cylindrical solid rods, wire bundles supported by hollow molybdenum tubes, cylindrical hollow tubes, and hollow cathodes of the type used in ion thrusters. The results of the mass loss tests in nitrogen indicated that pure tungsten eroded at a rate more than 10 times faster than the rates of the impregnated tungsten materials. It was found that oxygen impurities of less than 0.5 percent in the nitrogen increased the mass loss rate by a factor of 4 over high purity nitrogen. At power levels less than 1 kW, cathode size and current level did not significantly affect the mass loss rate. The hollow cathode was found to be operable in argon and in nitrogen only at pressures below 400 and 200 torr, respectively.

  15. Cathode degradation and erosion in high pressure arc discharges

    NASA Technical Reports Server (NTRS)

    Hardy, T. L.; Nakanishi, S.

    1983-01-01

    The various processes which control cathode erosion and degradation were identified and evaluated. A direct current arc discharge was established between electrodes in a pressure-controlled gas flow environment. The cathode holder was designed for easy testing of various cathode materials. The anode was a water cooled copper collector electrode. The arc was powered by a dc power supply with current and voltage regulated cross-over control. Nitrogen and argon were used as propellants and the materials used were two percent thoriated tungsten, barium oxide impregnated porous tungsten, pure tungsten and lanthanum hexaboride. The configurations used were cylindrical solid rods, wire bundles supported by hollow molybdenum tubes, cylindrical hollow tubes, and hollow cathodes of the type used in ion thrusters. The results of the mass loss tests in nitrogen indicated that pure tungsten eroded at a rate more than 10 times faster than the rates of the impregnated tungsten materials. It was found that oxygen impurities of less than 0.5 percent in the nitrogen increased the mass loss rate by a factor of 4 over high purity nitrogen. At power levels less than 1 kW, cathode size and current level did not significantly affect the mass loss rate. The hollow cathode was found to be operable in argon and in nitrogen only at pressures below 400 and 200 torr, respectively.

  16. Pulsed Discharge Helium Ionization Detector for Highly Sensitive Aquametry.

    PubMed

    Mowry, Curtis D; Pimentel, Adam S; Sparks, Elizabeth S; Moorman, Matthew W; Achyuthan, Komandoor E; Manginell, Ronald P

    2016-01-01

    Trace moisture quantitation is crucial in medical, civilian and military applications. Current aquametry technologies are limited by the sample volume, reactivity, or interferences, and/or instrument size, weight, power, cost, and complexity. We report for the first time on the use of a pulsed discharge helium ionization detector (PDHID-D2) (∼196 cm(3)) for the sensitive (limit of detection, 0.047 ng; 26 ppm), linear (r(2) >0.99), and rapid (< 2 min) quantitation of water using a small (0.2 - 5.0 μL) volume of liquid or gas. The relative humidity sensitivity was 0.22% (61.4 ppmv) with a limit of detection of less than 1 ng moisture with gaseous samples. The sensitivity was 10 to 100 to fold superior to competing technologies without the disadvantages inherent to these technologies. The PDHID-D2, due to its small footprint and low power requirement, has good size, weight, and power-portability (SWAPP) factors. The relatively low cost (∼$5000) and commercial availability of the PDHID-D2 makes our technique applicable to highly sensitive aquametry. PMID:26860562

  17. Submarine Ground-Water Discharge and Its Influence on the Greater Jakarta Bay Ecosystems

    NASA Astrophysics Data System (ADS)

    Lubis, R. F.; Delinom, R.; Bakti, H.; Taniguchi, M.

    2013-12-01

    Jakarta Bay and Kepulauan Seribu (Thousand islands) essentially form a large coastal ecosystem with relatively different characteristics. The whole ecosystem, which is called Greater Jakarta Bay Ecosystem stretches from 106o 20' and 107o 03' east longitude, and from 5o10' to 6o10' south latitude, and is administratively within three provinces. The greater Jakarta bay is mainly influenced by land-based activities. The bay is exposed to high pollution load transported and increase of nutrient loading in from up-land region by 13 rivers and submarine groundwater discharge (SGD). SGD defined as all direct discharge of subsurface fluids in to coastal zone. Components of SGD consist of fresh submarine groundwater discharge and the recirculated saline seawater discharge. SGD is as pathway for the transport of anthropogenic contaminants and nutrients to coastal waters. SGD has recently been recognized as a ubiquitous phenomenon that can strongly influence coastal-water and geochemical budgets and drive ecosystem change. This paper reported that SGD was defined and can be measured. It is likely that the threat from anthropogenic sources is greater than that of natural sources; hence the human activities will continue to dominate the fate of the greater Jakarta Bay ecosystem in the next few decades.Keywords

  18. Arc discharge-mediated disassembly of viral particles in water.

    PubMed

    Lee, Eun-Jung; Lee, Wooseong; Kim, Minwoo; Choi, Eun Ha; Kim, Yun-Ji

    2016-10-01

    In this study, we investigated the inactivation effects on murine norovirus (MNV-1) with/without purification in water using a submerged plasma reactor of arc discharge (underwater arc), which produced a shockwave, UV light, reactive oxygen species and reactive nitrogen species. Underwater arc treatments of 3 and 6 Hz at 12 kV resulted in 2.6- and 4.2-log reductions in the virus titer of non-purified MNV-1 after 1 min of treatment, respectively. The reduction of purified MNV-1 was higher than that of non-purified MNV-1 after underwater arc treatment for all applied conditions (12 or 15 kV and 3 or 6 Hz). One of the viral capsid proteins (VP1) was not detectable after underwater arc treatment, when its integrity was assessed by western blot analysis. Transmission electron microscopy analysis also revealed that MNV-1 particles were completely dissembled by the treatment. This study demonstrates that underwater arc treatment, which was capable of disintegrating the MNV-1 virion structure and the viral capsid protein, can be an effective disinfection process for the inactivation of water-borne noroviruses. PMID:27379726

  19. High voltage pulse ignition of mercury discharge hollow cathodes

    NASA Technical Reports Server (NTRS)

    Wintucky, E. G.

    1973-01-01

    A high voltage pulse generated by a capacitor discharge into a step-up transformer has been demonstrated capable of consistently igniting hollow cathode mercury discharges at propellant flows and heater power levels much below those required by conventional cathode starting. Results are presented for 3.2-mm diameter enclosed and open keeper cathodes. Starting characteristics are shown to depend on keeper voltage, mercury flow rate, heater power, keeper orifice size, emissive materials, and electrode to which the pulse is applied. This starting technique has been used to start a cathode over 10,000 times without any degradation of starting capability.

  20. High-order harmonic generation in a capillary discharge

    DOEpatents

    Rocca, Jorge J.; Kapteyn, Henry C.; Mumane, Margaret M.; Gaudiosi, David; Grisham, Michael E.; Popmintchev, Tenio V.; Reagan, Brendan A.

    2010-06-01

    A pre-ionized medium created by a capillary discharge results in more efficient use of laser energy in high-order harmonic generation (HHG) from ions. It extends the cutoff photon energy, and reduces the distortion of the laser pulse as it propagates down the waveguide. The observed enhancements result from a combination of reduced ionization energy loss and reduced ionization-induced defocusing of the driving laser as well as waveguiding of the driving laser pulse. The discharge plasma also provides a means to spectrally tune the harmonics by tailoring the initial level of ionization of the medium.

  1. High efficiency ionizer using a hollow cathode discharge plasma

    SciTech Connect

    Alessi, J.G.; Prelec, K.

    1984-01-01

    A proposal for an ionizer using a hollow cathode discharge plasma is described. Ionization is via the very high current density electron beam component in the plasma, as well as from charge exchange with plasma ions. Extraction of a He/sup +/ current corresponding to approximately 50% of the incoming atomic beam flux should be possible.

  2. Nonlinear behavior in high-intensity discharge lamps

    NASA Astrophysics Data System (ADS)

    Baumann, Bernd; Schwieger, Joerg; Wolff, Marcus; Manders, Freddy; Suijker, Jos

    2016-06-01

    The light flicker problem of high intensity discharge lamps is studied numerically and experimentally. It is shown that in some respects the systems behave very similar to the forced Duffing oscillator with a softening spring. In particular, the jump phenomenon and hysteresis are observed in the simulations and in the experiments.

  3. Process for increasing the water discharge of water delivering drilled wells, previously used for water delivery, and having decreased water discharge

    SciTech Connect

    Gomory, P.; Hegedus, J.; Kiss, F.; Simon, A.

    1985-09-17

    Process for increasing the water discharge of water delivering drilled wells, which can be characterized in that into the filter section of the well weak acids with a dissociation constant being less than K /SUB d/ =10/sup -3/ are introduced. After a dwelling period of longer duration, expediently 10 to 48 hours, as well as compressing, flushing is performed by means of a scavenging pump. Thereafter the solution of sodium bicarbonate and/or sodium hypochlorite is introduced into the filter section. After a longer dwelling period, expediently one to thirty-six hours, flushing is performed by means of the scavenging pump. As weak acids with a dissociation constant being less than K /SUB d/ =10/sup -3/ acetic acid, tartaric acid, citric acid, metaboric and/or tetraboric acid is used.

  4. Glow discharge deposition at high rates using disilane

    SciTech Connect

    Rajeswaran, G.; Corderman, R.R.; Kampas, F.J.; Vanier, P.E.

    1985-01-01

    The research program reported makes use of the fact that amorphous silicon films can be grown faster from disilane in a glow discharge than from the traditional silane. The goal is to find a method to grow films at a high rate and with sufficiently high quality to be used in an efficient solar cell. It must also be demonstrated that the appropriate device structure can be successfully fabricated under conditions which give high deposition rates. High quality intrinsic films have been deposited at 20 A/s. Efficiency of 5.6% on steel substrates and 5.3% on glass substrates were achieved using disilane i-layers deposited at 15 A/s in a basic structure, without wide-gap doped layers or light trapping. Wide gap p-layers were deposited using disilane. Results were compared with those obtained at Vactronic using high power discharges of silane-hydrogen mixtures. (LEW)

  5. Statistical prediction of seasonal discharge in the Naryn basin for water resources planning in Central Asia

    NASA Astrophysics Data System (ADS)

    Apel, Heiko; Gafurov, Abror; Gerlitz, Lars; Unger-Shayesteh, Katy; Vorogushyn, Sergiy; Merkushkin, Aleksandr; Merz, Bruno

    2016-04-01

    exceptionally high skill reaching explained variances of 86% in the cross validation using ModSnow processed snow cover data and CRU temperature and precipitation data, i.e. freely available data only. Using antecedent discharge information from the Uchterek station over the period January to April the skill can be improved even further. Also the addition of latest EGSIEM GRACE products can improve this skill to > 90% explained variance by replacing the CRU temperature data in the forecast model. From all variables the ModSnow processed MODIS snow cover data proved to be the most important predictor. However, although the prediction models proved to be robust in the cross validation, it has to be mentioned that the models are based on a limited time spanning the period 2000-2012 only. Nevertheless it is believed that the models are reliable, as this time period shows a high variability in seasonal water availability spanning from exceptionally dry to wet years. In summary, the developed forecast model may be a valuable complementary tool for the seasonal discharge prediction in Central Asia for water resources planning, that does not suffer from limited data access required for other forecast methods.

  6. Discharge and water quality of Horse Creek, southeastern Wyoming, May-November, 1985

    USGS Publications Warehouse

    Meyer, J.F.; Lenfest, L.W., Jr.

    1986-01-01

    This report presents stream-discharge and water-quality data collected at five sites in the lower Horse Creek drainage of southeastern Wyoming, May through November, 1985. Data include stream-discharge measurements; field measurements of specific conductance, pH, and water temperature; and computer changes in stream discharge. Measured discharge in Horse Creek ranged from 0.91 to 172 cu ft/sec. Values of pH averaged 8.4. Water temperature ranged from 0 to 27 C. The data are presented in graphs and tables. A map of the study reach shows the location of the data collection sites. (USGS)

  7. Constraints for Using Radon-in-Water Concentrations as an Indicator for Groundwater Discharge into Surface Water Bodies

    NASA Astrophysics Data System (ADS)

    Petermann, Eric; Schubert, Michael

    2015-04-01

    The radon (222-Rn) activity concentration of surface water is a favourable indicator for the detection of groundwater discharge into surface water bodies since radon is highly enriched in groundwater relative to surface waters. Hence, positive radon-in-water anomalies are interpreted as groundwater discharge locations. For this approach, usually, radon time-series are recorded along transects in near-surface waters. Time-series of radon-in-water concentration are commonly measured by permanent radon extraction from a water pump stream and continuous monitoring of the resulting radon-in-air concentration by means of a suitable radon detector. Radon-in-water concentrations are derived from the recorded radon-in-air signal by making allowances for water/air partitioning of radon. However, several constraints arise for this approach since undesirable factors are influencing the radon-in-water concentration. Consequently, corrections are required to remove the effect of these undesirable factors from the radon signal. First, an instrument inherent response delay between actual changes in the radon-in-water concentration and the related radon-in-air signal was observed during laboratory experiments. The response delay is due to (i) the water/air transfer kinetics of radon and (ii) the delayed decay equilibrium between radon and its progeny polonium (218-Po), which is actually being measured by most radon-in-air monitors. We developed a physical model, which considers all parameters that are responsible for the response delay. This model allows the reconstruction of radon-in-water time-series based on radon-in-air records. Second, on a time-scale of several hours the tidal stage is known as a major driver for groundwater discharge fluctuations due to varying hydraulic gradients between groundwater and surface water during a tidal cycle. Consequently, radon-in-water time-series that are detected on tidal coasts are not comparable among each other without normalization

  8. Probability-based classifications for spatially characterizing the water temperatures and discharge rates of hot springs in the Tatun Volcanic Region, Taiwan.

    PubMed

    Jang, Cheng-Shin

    2015-05-01

    Accurately classifying the spatial features of the water temperatures and discharge rates of hot springs is crucial for environmental resources use and management. This study spatially characterized classifications of the water temperatures and discharge rates of hot springs in the Tatun Volcanic Region of Northern Taiwan by using indicator kriging (IK). The water temperatures and discharge rates of the springs were first assigned to high, moderate, and low categories according to the two thresholds of the proposed spring classification criteria. IK was then used to model the occurrence probabilities of the water temperatures and discharge rates of the springs and probabilistically determine their categories. Finally, nine combinations were acquired from the probability-based classifications for the spatial features of the water temperatures and discharge rates of the springs. Moreover, various combinations of spring water features were examined according to seven subzones of spring use in the study region. The research results reveal that probability-based classifications using IK provide practicable insights related to propagating the uncertainty of classifications according to the spatial features of the water temperatures and discharge rates of the springs. The springs in the Beitou (BT), Xingyi Road (XYR), Zhongshanlou (ZSL), and Lengshuikeng (LSK) subzones are suitable for supplying tourism hotels with a sufficient quantity of spring water because they have high or moderate discharge rates. Furthermore, natural hot springs in riverbeds and valleys should be developed in the Dingbeitou (DBT), ZSL, Xiayoukeng (XYK), and Macao (MC) subzones because of low discharge rates and low or moderate water temperatures. PMID:25917185

  9. Specific Conductivity Synoptic Surveys to Map Groundwater-Surface Water Discharges in a Lowland River

    NASA Astrophysics Data System (ADS)

    Pai, H.; Villamizar, S. R.; Harmon, T. C.

    2014-12-01

    Quantifying distributed groundwater-surface water (GW-SW) discharges at the watershed scale is a challenging but important aspect of tracking nonpoint-source pollutants and their potential impacts on riverine water quality. This work analyzes high spatiotemporal longitudinal river sampling along a 38 km reach of the lower Merced River (LMR) in California's San Joaquin River (SJR) watershed and estimates GW-SW discharges using a simple discretized mixing model. The LMR flow is dam-controlled upstream and has several distributed surface discharges from SW diversions, SW canal inputs, and potential GW discharges influenced by the surrounding agricultural and municipal landscapes. We collected longitudinal datasets covering a wide range of flows (1.3 to 150 m3/s), sampling georeferenced water specific conductance (SC) at intervals of less than 1 minute. Whole-reach gradients of SW specific conductance (SC), representing GW-SW salinity loading (mS/cm/river km), decreased in proportion to the flow and stage, indicating either (1) a simple dilution effect or (2) reduced GW-SW discharges due to a reduced GW-SW hydraulic gradient at higher stages. With respect to distributed discharges, local gradients were significant (p < 0.05), with estimated local salinity loads varying from -0.4 to 8.9 mS/cm/river km for the LMR conditions. Using local groundwater salinity estimates, we inverted a discretized mixing model to estimate distributed groundwater fluxes. Summation of the fluxes agreed well with stream gage estimates. However, local flux estimates were nonuniform, with mid-reach values consistently increasing to a maximum value at intermediate stream flows, then decreasing for greater flows. Causes for this behavior remain uncertain but may be due to one or more of the following: (1) uncertainty in the groundwater salinity data, (2) salinity reduction in the hyporheic zone (e.g., denitrification), and (3) access to preferential GW-SW flowpaths at intermediate flows and stages

  10. Improvement of growth rate of plants by bubble discharge in water

    NASA Astrophysics Data System (ADS)

    Takahata, Junichiro; Takaki, Koichi; Satta, Naoya; Takahashi, Katsuyuki; Fujio, Takuya; Sasaki, Yuji

    2015-01-01

    The effect of bubble discharge in water on the growth rate of plants was investigated experimentally for application to plant cultivation systems. Spinach (Spinacia oleracea), radish (Raphanus sativus var. sativus), and strawberry (Fragaria × ananassa) were used as specimens to clarify the effect of the discharge treatment on edible parts of the plants. The specimens were cultivated in pots filled with artificial soil, which included chicken manure charcoal. Distilled water was sprayed on the artificial soil and drained through a hole in the pots to a water storage tank. The water was circulated from the water storage tank to the cultivation pots after 15 or 30 min discharge treatment on alternate days. A magnetic compression-type pulsed power generator was used to produce the bubble discharge with a repetition rate of 250 pps. The plant height in the growth phase and the dry weight of the harvested plants were improved markedly by the discharge treatment in water. The soil and plant analyzer development (SPAD) value of the plants also improved in the growth phase of the plants. The concentration of nitrate nitrogen, which mainly contributed to the improvement of the growth rate, in the water increased with the discharge treatment. The Brix value of edible parts of Fragaria × ananassa increased with the discharge treatment. The inactivation of bacteria in the water was also confirmed with the discharge treatment.

  11. Surface water quality management using an integrated discharge permit and the reclaimed water market.

    PubMed

    Jamshidi, Shervin; Niksokhan, Mohammad Hossein; Ardestani, Mojtaba

    2014-01-01

    Water quality trading is a sustainable framework for surface water quality management. It uses discharge permits to reduce the total treatment costs. For example, the case of Gharesoo River in Iran shows that the nitrogen permit market between point and non-point sources is 37% more economical than the command and control framework. Nevertheless, the cost saving may be reduced to 6% by the end of the study period (2050). This depression may be due to the limited technical support for wastewater treatment plants. Therefore, an integrated market is recommended in which the discharge permits and the reclaimed water are traded simultaneously. In this framework, the allocation of secondary treated domestic wastewater for irrigation can provide capacity for other pollutants to discharge into the surface water. This innovative approach may decrease the total treatment costs by 63% at present, while 65%, may be achieved by the end of the study period. Furthermore, this market is able to determine the environmental penalty, trading permits, and reuse prices. For example, the maximum ratio of the average reuse price to the penalty cost is determined as 1 to 10. It is introduced as an incentive indicator for stakeholders to consider the integrated market. Consequently, the applicability and the efficiency of using this approach are verified long term. PMID:25225941

  12. Relatively high plasma density in low pressure inductive discharges

    SciTech Connect

    Kang, Hyun-Ju; Kim, Yu-Sin; Chung, Chin-Wook

    2015-09-15

    Electron energy probability functions (EEPFs) were measured in a low pressure argon inductive discharge. As radio frequency (RF) power increases, discharge mode is changed from E-mode (capacitively coupled) to H-mode (inductively coupled) and the EEPFs evolve from a bi-Maxwellian distribution to a Maxwellian distribution. It is found that the plasma densities at low RF powers (<30 W) are much higher than the density predicted from the slope of the densities at high powers. Because high portion of high energy electrons of the bi-Maxwellian distribution lowers the collisional energy loss and low electron temperature of low energy electrons reduces particle loss rate at low powers. Therefore, the energy loss of plasma decreases and electron densities become higher at low powers.

  13. Reconnaissance investigations of the discharge and water quality of the Amazon River

    USGS Publications Warehouse

    Oltman, Roy Edwin

    1968-01-01

    Selected published estimates of the discharge of Amazon River in the vicinity of Obidos and the mouth are presented to show the great variance of available information. The most reasonable estimates prepared by those who measured some parameters of the flow were studied by Maurice Parde, who concluded that the mean annual discharge is 90,000 to 100,000 cms (cubic meters per second) or 3,200,000 to 3,500,000 cfs (cubic feet per second). A few published estimates of discharge at mouth of 110,000 cms (3,900,000 cfs) based on rainfall-runoff relationships developed for other humid regions of the world are available. Three measurements of discharge made at the Obidos narrows in 1963-64 by a joint Brazil-United States expedition at high, low, and medium river stage are referred to the datum used at the Obidos gage during the period of operation, 1928-46, and a relationship between stage and discharge prepared on the basis of the measurements and supplementary data and computations. Recovery of the original Obidos gage datum is verified by referring the 1963-64 concurrent river stages at Manaus, Obidos, and Taperinha to gage relation curves developed for Manaus-Obidos and Obidos-Taperinha for periods of concurrent operation, 1928-46 and 1931-46, respectively. The average discharge, based on the stage-discharge relation and record of river stage for the period 1928-46, is computed to be 5,500,000 cfs (157,000 cms) for the Obidos site. The greatest known flood at Obidos, that of June 1953, is computed to have been a flow of 12,500,000 cfs (350,000 cms) at stage of 7.6 meters (24.9 feet) in the main channel and an indeterminate amount of overflow which, under the best assumed overflow conditions, may have amounted to about 10 percent of the main channel flow. Overflow discharge at stage equivalent to mean annual discharge is judged to be an insignificant percentage of flow down the main channel. Miscellaneous data collected during the flow measurements show that the tidal

  14. Characterization of high power impulse magnetron sputtering discharges

    NASA Astrophysics Data System (ADS)

    Hala, Matej

    Paper I: In the first paper, we present a new approach in the characterization of the high power pulsed magnetron sputtering (HiPIMS) discharge evolution—time- and species-resolved plasma imaging—employing a set of band-pass optical interference filters suitable for the isolation of the emission originating from different species populating the plasma. We demonstrate that the introduction of such filters can be used to distinguish different phases of the discharge, and to visualize numerous plasma effects including background gas excitations during the discharge ignition, gas shock waves, and expansion of metal-rich plasmas. In particular, the application of this technique is shown on the diagnostics of the 200 µs long non-reactive HiPIMS discharges using a Cr target. Paper II: In order to gain further information about the dynamics of reactive HiPIMS discharges, both fast plasma imaging and time- and space-resolved optical emission spectroscopy (OES) are used for a systematic investigation of the 200 µs long HiPIMS pulses operated in Ar, N2 and N 2/Ar mixtures and at various pressures. It is observed that the dense metal plasma created next to the target propagates in the reactor at a speed ranging from 0.7 to 3.5 km s-1, depending on the working gas composition and the pressure. In fact, it increases with higher N 2 concentration and with lower pressure. The visible form of the propagating plasma wave changes from a hemispherical shape in Ar to a drop-like shape extending far from the target with increasing N2 concentration, owing to the significant emission from molecular N2. Interestingly, the evidence of the target self-sputtering is found for all investigated conditions, including pure N2 atmosphere. Paper III: Here, we report on the time- and species-resolved plasma imaging analysis of the dynamics of the 200 µs long HiPIMS discharges above a Cr target ignited in pure O2. It is shown that the discharge emission is dominated solely by neutral and

  15. Experimental characterization of plasma formation and shockwave propagation induced by high power pulsed underwater electrical discharge.

    PubMed

    Claverie, A; Deroy, J; Boustie, M; Avrillaud, G; Chuvatin, A; Mazanchenko, E; Demol, G; Dramane, B

    2014-06-01

    High power pulsed electrical discharges into liquids are investigated for new industrial applications based on the efficiency of controlled shock waves. We present here new experimental data obtained by combination of detailed high speed imaging equipments. It allows the visualization of the very first instants of plasma discharge formation, and then the pulsations of the gaseous bubble with an accurate timing of events. The time history of the expansion/compression of this bubble leads to an estimation of the energy effectively transferred to water during the discharge. Finally, the consecutive shock generation driven by this pulsating bubble is optically monitored by shadowgraphs and schlieren setup. These data provide essential information about the geometrical pattern and chronometry associated with the shock wave generation and propagation. PMID:24985821

  16. Experimental study of the water jet induced by underwater electrical discharge in a narrow rectangular tube

    NASA Astrophysics Data System (ADS)

    Koita, T.; Zhu, Y.; Sun, M.

    2016-05-01

    This paper reports an experimental investigation on the effects of explosion depth and tube width on the water jet induced by an underwater electrical discharge in a narrow rectangular tube. The water jet formation and bubble structure were evaluated from the images recorded by a high-speed video camera. Two typical patterns of jet formation and four general patterns of bubble implosion were observed, depending on the explosion depth and tube width. The velocity of the water jet was calculated from the recorded images. The jet velocity was observed to depend on not only the explosion depth and energy, but also on the tube width. We proposed an empirical formula defining the water jet velocity in the tube as a function of the tube width and explosion depth and energy.

  17. Plasma Discharges in Gas Bubbles in Liquid Water: Breakdown Mechanisms and Resultant Chemistry

    NASA Astrophysics Data System (ADS)

    Gucker, Sarah M. N.

    The use of atmospheric pressure plasmas in gases and liquids for purification of liquids has been investigated by numerous researchers, and is highly attractive due to their strong potential as a disinfectant and sterilizer. However, the fundamental understanding of plasma production in liquid water is still limited. Despite the decades of study dedicated to electrical discharges in liquids, many physical aspects of liquids, such as the high inhomogeneity of liquids, complicate analyses. For example, the complex nonlinearities of the fluid have intricate effects on the electric field of the propagating streamer. Additionally, the liquid material itself can vaporize, leading to discontinuous liquid-vapor boundaries. Both can and do often lead to notable hydrodynamic effects. The chemistry of these high voltage discharges on liquid media can have circular effects, with the produced species having influence on future discharges. Two notable examples include an increase in liquid conductivity via charged species production, which affects the discharge. A second, more complicated scenario seen in some liquids (such as water) is the doubling or tripling of molecular density for a few molecule layers around a high voltage electrode. These complexities require technological advancements in optical diagnostics that have only recently come into being. This dissertation investigates several aspects of electrical discharges in gas bubbles in liquids. Two primary experimental configurations are investigated: the first allows for single bubble analysis through the use of an acoustic trap. Electrodes may be brought in around the bubble to allow for plasma formation without physically touching the bubble. The second experiment investigates the resulting liquid phase chemistry that is driven by the discharge. This is done through a dielectric barrier discharge with a central high voltage surrounded by a quartz discharge tube with a coil ground electrode on the outside. The plasma

  18. Influence of water conductivity on particular electrospray modes with dc corona discharge — optical visualization approach

    NASA Astrophysics Data System (ADS)

    Pongrác, Branislav; Kim, Hyun-Ha; Negishi, Nobuaki; Machala, Zdenko

    2014-08-01

    The effect of water conductivity on electrospraying of water was studied in combination with positive DC corona discharge generated in air. We used a point-to-plane geometry of electrodes with a hollow syringe needle anode opposite to the metal mesh cathode. We employed total average current measurements and high-speed camera fast time-resolved imaging. We visualized the formation of a water jet (filament) and investigated corona discharge behavior for various water conductivities. Depending on the conductivity, various jet properties were observed: pointy, prolonged, and fast spreading water filaments for lower conductivity; in contrast to rounder, broader, and shorter quickly disintegrating filaments for higher conductivity. The large acceleration values (4060 m/s2 and 520 m/s2 for 2 μS/cm and 400 μS/cm, respectively) indicate that the process is mainly governed by the electrostatic force. In addition, with increasing conductivity, the breakdown voltage for corona-to-spark transition was decreasing.

  19. Investigation of free discharge through the hydro units of high head Francis turbine

    NASA Astrophysics Data System (ADS)

    Kuznetsov, I.; Zakharov, A.; Orekhov, G.; Minakov, A.; Dekterev, A.; Platonov, D.

    2012-11-01

    Free discharge through the units is applied in the course of construction of hydro power plant or in case of excessive water inflow during floods or emergency situation. Free discharges throw the hydro units at 80 m head and more are unknown. Possibility of high velocity swirling flow discharged through the whole hydro unit consisting of penstock, turbine (with Francis runner and distributor or without them) and draft tube is being analyzed in the present paper. Investigation method is based on mathematical simulation of unsteady flow through the hydro unit under the following conditions: with the free running or locked runner and with removed runner. Physical researches of the swirling flow behavior in the model bent penstocks and model turbine water passages have been performed. Based on the results of calculations and model tests the following extensive data have been obtained: pressure fluctuation in the whole hydro unit, fluctuation of hydrodynamic forces acting on guide vanes, torque fluctuation on the runner and discharge fluctuation. Thus, based on this data preferable designs of free discharge are proposed.

  20. Zero Discharge Water Management for Horizontal Shale Gas Well Development

    SciTech Connect

    Paul Ziemkiewicz; Jennifer Hause; Raymond Lovett; David Locke Harry Johnson; Doug Patchen

    2012-03-31

    Hydraulic fracturing technology (fracking), coupled with horizontal drilling, has facilitated exploitation of huge natural gas (gas) reserves in the Devonian-age Marcellus Shale Formation (Marcellus) of the Appalachian Basin. The most-efficient technique for stimulating Marcellus gas production involves hydraulic fracturing (injection of a water-based fluid and sand mixture) along a horizontal well bore to create a series of hydraulic fractures in the Marcellus. The hydraulic fractures free the shale-trapped gas, allowing it to flow to the well bore where it is conveyed to pipelines for transport and distribution. The hydraulic fracturing process has two significant effects on the local environment. First, water withdrawals from local sources compete with the water requirements of ecosystems, domestic and recreational users, and/or agricultural and industrial uses. Second, when the injection phase is over, 10 to 30% of the injected water returns to the surface. This water consists of flowback, which occurs between the completion of fracturing and gas production, and produced water, which occurs during gas production. Collectively referred to as returned frac water (RFW), it is highly saline with varying amounts of organic contamination. It can be disposed of, either by injection into an approved underground injection well, or treated to remove contaminants so that the water meets the requirements of either surface release or recycle use. Depending on the characteristics of the RFW and the availability of satisfactory disposal alternatives, disposal can impose serious costs to the operator. In any case, large quantities of water must be transported to and from well locations, contributing to wear and tear on local roadways that were not designed to handle the heavy loads and increased traffic. The search for a way to mitigate the situation and improve the overall efficiency of shale gas production suggested a treatment method that would allow RFW to be used as make

  1. High energy XeBr electric discharge laser

    DOEpatents

    Sze, R.C.; Scott, P.B.

    A high energy XeBr laser for producing coherent radiation at 282 nm is disclosed. The XeBr laser utilizes an electric discharge as the excitation source to minimize formation of molecular ions thereby minimizing absorption of laser radiation by the active medium. Additionally, HBr, is used as the halogen donor which undergoes harpooning reactions with Xe/sub M/ to form XeBr.

  2. High energy KrCl electric discharge laser

    DOEpatents

    Sze, R.C.; Scott, P.B.

    A high energy KrCl laser is presented for producing coherent radiation at 222 nm. Output energies on the order of 100 mJ per pulse are produced utilizing a discharge excitation source to minimize formation of molecular ions, thereby minimizing absorption of laser radiation by the active medium. Additionally, HCl is used as a halogen donor which undergoes a harpooning reaction with metastable Kr/sub M/ to form KrCl.

  3. High energy KrCl electric discharge laser

    DOEpatents

    Sze, Robert C.; Scott, Peter B.

    1981-01-01

    A high energy KrCl laser for producing coherent radiation at 222 nm. Output energies on the order of 100 mJ per pulse are produced utilizing a discharge excitation source to minimize formation of molecular ions, thereby minimizing absorption of laser radiation by the active medium. Additionally, HCl is used as a halogen donor which undergoes a harpooning reaction with metastable Kr.sub.M * to form KrCl.

  4. High energy XeBr electric discharge laser

    DOEpatents

    Sze, Robert C.; Scott, Peter B.

    1981-01-01

    A high energy XeBr laser for producing coherent radiation at 282 nm. The XeBr laser utilizes an electric discharge as the excitation source to minimize formation of molecular ions thereby minimizing absorption of laser radiation by the active medium. Additionally, HBr is used as the halogen donor which undergoes harpooning reactions with Xe.sub.M * to form XeBr*.

  5. Properties of UN Sintered by High Voltage Electric Discharge Consolidation

    NASA Astrophysics Data System (ADS)

    Yurlova, M.; Tarasov, B.; Shornikov, D.; Grigoryev, E.; Olevsky, E.

    In the present work, the opportunity of the consolidation of uranium nitride tablets by high voltage electric discharge consolidation (HVEDC) is considered. It is shown that the consolidation by HVEDC allows the prevention of the expansion of uranium nitride powders and renders pellets with relative density of up to 97%. The thermal stability of the obtained samples has been investigated. The analysis of the microstructure of the processed samples indicates the retention of the initial powder structure

  6. Electric discharges produced by clouds of charged water droplets in the presence of moving conducting object

    NASA Astrophysics Data System (ADS)

    Kostinskiy, Alexander Y.; Syssoev, Vladimir S.; Mareev, Eugene A.; Rakov, Vladimir A.; Andreev, Mikhail G.; Bogatov, Nikolai A.; Makal'sky, Leonid M.; Sukharevsky, Dmitry I.; Aleshchenko, Alexander S.; Kuznetsov, Vladimir E.; Shatalina, Maria V.

    2015-12-01

    The possibility of initiation of electric discharges by a crossbow bolt (projectile) moving in the electric field of a cloud of negatively charged water droplets has been demonstrated for the first time. Over one hundred of discharges have been produced. For each event, a high-speed video camera recorded the images of upward positive leaders developing from both the nearby grounded sphere and the projectile, followed by the return-stroke-like process. Corresponding currents were measured and integrated photos of the events were obtained. The results can help to improve our understanding of lightning initiation by airborne vehicles and by a vertical conductor rapidly extended below the thundercloud in order to trigger lightning with the rocket-and-wire technique.

  7. Analyzing Conductivity Profiles in Stream Waters Influenced by Mine Water Discharges

    NASA Astrophysics Data System (ADS)

    Räsänen, Teemu; Hämäläinen, Emmy; Hämäläinen, Matias; Turunen, Kaisa; Pajula, Pasi; Backnäs, Soile

    2015-04-01

    Conductivity is useful as a general measure of stream water quality. Each stream inclines to have a quite constant range of conductivity that can be used as a baseline for comparing and detecting influence of contaminant sources. Conductivity in natural streams and rivers is affected primarily by the geology of the watershed. Thus discharges from ditches and streams affect not only the flow rate in the river but also the water quality and conductivity. In natural stream waters, the depth and the shape of the river channel change constantly, which changes also the water flow. Thus, an accurate measuring of conductivity or other water quality indicators is difficult. Reliable measurements are needed in order to have holistic view about amount of contaminants, sources of discharges and seasonal variation in mixing and dilution processes controlling the conductivity changes in river system. We tested the utility of CastAway-CTD measuring device (SonTek Inc) to indicate the influence of mine waters as well as mixing and dilution occurring in the recipient river affected by treated dewatering and process effluent water discharges from a Finnish gold mine. The CastAway-CTD measuring device is a small, rugged and designed for profiling of depths of up to 100m. Device measures temperature, salinity, conductivity and sound of speed using 5 Hz response time. It has also built-in GPS which produces location information. CTD casts are normally used to produce vertical conductivity profile for rather deep waters like seas or lakes. We did seasonal multiple Castaway-CTD measurements during 2013 and 2014 and produced scaled vertical and horizontal profiles of conductivity and water temperature at the river. CastAway-CTD measurement pinpoints how possible contaminants behave and locate in stream waters. The conductivity profiles measured by CastAway-CTD device show the variation in maximum conductivity values vertically in measuring locations and horizontally in measured cross

  8. Volume Diffuse Dielectric Barrier Discharge Plasma Produced by Nanosecond High Voltage Pulse in Airflow

    NASA Astrophysics Data System (ADS)

    Qi, Haicheng; Gao, Wei; Fan, Zhihui; Liu, Yidi; Ren, Chunsheng

    2016-05-01

    Volume diffuse dielectric barrier discharge (DBD) plasma is produced in subsonic airflow by nanosecond high-voltage pulse power supply with a plate-to-plate discharge cell at 6 mm air gap length. The discharge images, optical emission spectra (OES), the applied voltage and current waveforms of the discharge at the changed airflow rates are obtained. When airflow rate is increased, the transition of the discharge mode and the variations of discharge intensity, breakdown characteristics and the temperature of the discharge plasma are investigated. The results show that the discharge becomes more diffuse, discharge intensity is decreased accompanied by the increased breakdown voltage and time lag, and the temperature of the discharge plasma reduces when airflow of small velocity is introduced into the discharge gap. These phenomena are because that the airflow changes the spatial distribution of the heat and the space charge in the discharge gap. supported by National Natural Science Foundation of China (No. 51437002)

  9. [Removal of SO2 from flue gas by water vapor DC corona discharge].

    PubMed

    Sun, Ming; Wu, Yan

    2006-07-01

    The influence of several factors on removal rate of SO2 from flue gas in unsaturated water vapor DC corona discharge was researched. Furthermore, the experiments of the removal rate of SO2 in pulsed discharge increased by water vapor DC corona discharge plasma were conducted. The experiment system is supplied with multi-nozzle-plate electrodes and the flow of simulated flue gas is under 70 m3/h. The results show that removal rate of SO2 can be improved by increasing the concentration of water vapor, intensity of electric field or decreasing flow of simulated flue gas. In unsaturated water vapor DC corona discharge, removal rate of SO2 can be improved by 10%, when NH3 is added as NH3 and SO2 is in a mole ratio of two to one, it can reach 60%. The removal rate of SO2 can be increased by 5% in pulsed corona discharge and reach above 90%. PMID:16881295

  10. The electro-acoustic transition process of pulsed corona discharge in conductive water

    NASA Astrophysics Data System (ADS)

    Huang, Yifan; Yan, Hui; Wang, Bingzhe; Zhang, Xuming; Liu, Zhen; Yan, Keping

    2014-06-01

    A pulsed corona discharge in conductive water is studied theoretically and experimentally via pre-discharge analysis, thermodynamic and dynamic processes of a plasma-containing bubble, an acoustic signature and energy partitioning. The total particle density and electron density inside the bubble, internal temperature and pressure, bubble radius and bubble wall Mach number are simulated by solving a set of equations including the ideal gas equation, Rayleigh equation and energy balance equation. The bubble radius is also measured by a high-speed charge-coupled device camera on a homemade experimental device. The acoustic waveforms and their power spectral density are calculated indirectly. By using several diagnostic tools, the electrical parameters of the load, light emission from the plasma and acoustic waveforms are recorded simultaneously. Simulation and experimental results of the bubble radius and acoustic signature agree reasonably well over the range of energy inputs from 5 to 30 J per pulse. Different kinds of terminations or intermediates of the energy transition process are analysed through simulation and experimental data. The electro-acoustic efficiency varies from 0.8% to 1.9%, while most of the discharge energy is consumed by circuit loss, Joule heating and thermal radiation, or is transformed into kinetic energy in the water.

  11. Multi-Model Assessment of Global Hydropower and Cooling Water Discharge Potential Under Climate Change

    NASA Technical Reports Server (NTRS)

    van Vliet, M. T. H.; van Beek, L. P. H.; Eisener, S.; Wada, Y.; Bierkens, M. F. P.

    2016-01-01

    Worldwide, 98% of total electricity is currently produced by thermoelectric power and hydropower. Climate change is expected to directly impact electricity supply, in terms of both water availability for hydropower generation and cooling water usage for thermoelectric power. Improved understanding of how climate change may impact the availability and temperature of water resources is therefore of major importance. Here we use a multi-model ensemble to show the potential impacts of climate change on global hydropower and cooling water discharge potential. For the first time, combined projections of streamflow and water temperature were produced with three global hydrological models (GHMs) to account for uncertainties in the structure and parametrization of these GHMs in both water availability and water temperature. The GHMs were forced with bias-corrected output of five general circulation models (GCMs) for both the lowest and highest representative concentration pathways (RCP2.6 and RCP8.5). The ensemble projections of streamflow and water temperature were then used to quantify impacts on gross hydropower potential and cooling water discharge capacity of rivers worldwide. We show that global gross hydropower potential is expected to increase between +2.4% (GCM-GHM ensemble mean for RCP 2.6) and +6.3% (RCP 8.5) for the 2080s compared to 1971-2000. The strongest increases in hydropower potential are expected for Central Africa, India, central Asia and the northern high-latitudes, with 18-33% of the world population living in these areas by the 2080s. Global mean cooling water discharge capacity is projected to decrease by 4.5-15% (2080s). The largest reductions are found for the United States, Europe, eastern Asia, and southern parts of South America, Africa and Australia, where strong water temperature increases are projected combined with reductions in mean annual streamflow. These regions are expected to affect 11-14% (for RCP2.6 and the shared socioeconomic

  12. Computer programs for describing the recession of ground-water discharge and for estimating mean ground-water recharge and discharge from streamflow records-update

    USGS Publications Warehouse

    Rutledge, A.T.

    1998-01-01

    The computer programs included in this report can be used to develop a mathematical expression for recession of ground-water discharge and estimate mean ground-water recharge and discharge. The programs are intended for analysis of the daily streamflow record of a basin where one can reasonably assume that all, or nearly all, ground water discharges to the stream except for that which is lost to riparian evapotranspiration, and where regulation and diversion of flow can be considered to be negligible. The program RECESS determines the master reces-sion curve of streamflow recession during times when all flow can be considered to be ground-water discharge and when the profile of the ground-water-head distribution is nearly stable. The method uses a repetitive interactive procedure for selecting several periods of continuous recession, and it allows for nonlinearity in the relation between time and the logarithm of flow. The program RORA uses the recession-curve displacement method to estimate the recharge for each peak in the streamflow record. The method is based on the change in the total potential ground-water discharge that is caused by an event. Program RORA is applied to a long period of record to obtain an estimate of the mean rate of ground-water recharge. The program PART uses streamflow partitioning to estimate a daily record of base flow under the streamflow record. The method designates base flow to be equal to streamflow on days that fit a requirement of antecedent recession, linearly interpolates base flow for other days, and is applied to a long period of record to obtain an estimate of the mean rate of ground-water discharge. The results of programs RORA and PART correlate well with each other and compare reasonably with results of the corresponding manual method.

  13. A comparative summary on streamers of positive corona discharges in water and atmospheric pressure gases

    NASA Astrophysics Data System (ADS)

    Tachibana, Kunihide; Motomura, Hideki

    2015-07-01

    From an intention of summarizing present understandings of positive corona discharges in water and atmospheric pressure gases, we tried to observe streamers in those media by reproducing and complementing previously reported results under a common experimental setup. We used a point-to-plane electrode configuration with different combinations of electrode gap (7 and 19 mm length) and pulsed power sources (0.25 and 2.5 ɛs duration). The general features of streamers were similar and the streamer-to-spark transition was also observed in both the media. However, in the details large differences were observed due to inherent nature of the media. The measured propagation speed of streamers in water of 0.035 × 106 ms-1 was much smaller than the speed in gases (air, N2 and Ar) from 0.4 to 1.1 × 106 ms-1 depending on species. In He the discharge looked glow-like and no streamer was observed. The other characteristics of streamers in gases, such as inception voltage, number of branches and thickness did also depend on the species. The thickness and the length of streamers in water were smaller than those in gases. From the volumetric expansion of a streamer in water after the discharge, the molecular density within the streamer medium was estimated to be rarefied from the density of water by about an order of magnitude in the active discharge phase. We derived also the electron density from the analysis of Stark broadened spectral lines of H and O atoms on the order of 1025 m-3 at the earlier time of the streamer propagation. The analyzed background blackbody radiation, rotational temperature of OH band emission and population density of Cu atomic lines yielded a consistent temperature of the streamer medium between 7000 and 10 000 K. Using the present data with a combination of the analysis of static electric field and previously reported results, we discuss the reason for the relatively low streamer inception voltage in water as compared to the large difference in the

  14. Water-Quality Assessment of Southern Florida - Wastewater Discharges and Runoff

    USGS Publications Warehouse

    Marella, Richard L.

    1998-01-01

    Nearly 800 million gallons per day of treated wastewater was discharged in the Southern Florida National Water-Quality Assessment (NAWQA) study unit in 1990, most to the Atlantic Ocean (44 percent) and to deep, saline aquifers (25 percent). About 9 percent was discharged to fresh surface waters and about 22 percent to shallow ground water, of which septic tanks accounted for 9 percent. Runoff from agricultural and urban lands, though not directly measured, is a large source of wastewater in southern Florida.

  15. Ground-water discharge determined from estimates of evapotranspiration, Death Valley regional flow system, Nevada and California

    USGS Publications Warehouse

    Laczniak, Randell J.; Smith, J. LaRue; Elliott, Peggy E.; DeMeo, Guy A.; Chatigny, Melissa A.; Roemer, Gaius J.

    2001-01-01

    The Death Valley regional flow system (DVRFS) is one of the larger ground-water flow systems in the southwestern United States and includes much of southern Nevada and the Death Valley region of eastern California. Centrally located within the ground-water flow system is the Nevada Test Site (NTS). The NTS, a large tract covering about 1,375 square miles, historically has been used for testing nuclear devices and currently is being studied as a potential repository for the long-term storage of high-level nuclear waste generated in the United States. The U.S. Department of Energy, as mandated by Federal and State regulators, is evaluating the risk associated with contaminants that have been or may be introduced into the subsurface as a consequence of any past or future activities at the NTS. Because subsurface contaminants can be transported away from the NTS by ground water, components of the ground-water budget are of great interest. One such component is regional ground-water discharge. Most of the ground water leaving the DVRFS is limited to local areas where geologic and hydrologic conditions force ground water upward toward the surface to discharge at springs and seeps. Available estimates of ground-water discharge are based primarily on early work done as part of regional reconnaissance studies. These early efforts covered large, geologically complex areas and often applied substantially different techniques to estimate ground-water discharge. This report describes the results of a study that provides more consistent, accurate, and scientifically defensible measures of regional ground-water losses from each of the major discharge areas of the DVRFS. Estimates of ground-water discharge presented in this report are based on a rigorous quantification of local evapotranspiration (ET). The study identifies areas of ongoing ground-water ET, delineates different ET areas based on similarities in vegetation and soil-moisture conditions, and determines an ET rate for

  16. Yield of Ozone, Nitrite Nitrogen and Hydrogen Peroxide Versus Discharge Parameter Using APPJ Under Water

    NASA Astrophysics Data System (ADS)

    Chen, Bingyan; Zhu, Changping; Fei, Juntao; He, Xiang; Yin, Cheng; Wang, Yuan; Gao, Ying; Jiang, Yongfeng; Wen, Wen; Chen, Longwei

    2016-03-01

    Discharge plasma in and in contact with water can be accompanied with ultraviolet radiation and electron impact, thus can generate hydroxyl radicals, ozone, nitrite nitrogen and hydrogen peroxide. In this paper, a non-equilibrium plasma processing system was established by means of an atmospheric pressure plasma jet immersed in water. The hydroxyl intensities and discharge energy waveforms were tested. The results show that the positive and negative discharge energy peaks were asymmetric, where the positive discharge energy peak was greater than the negative one. Meanwhile, the yield of ozone and nitrite nitrogen was enhanced with the increase of both the treatment time and the discharge energy. Moreover, the pH value of treated water was reduced rapidly and maintained at a lower level. The residual concentration of hydrogen peroxide in APPJ treated water was kept at a low level. Additionally, both the efficiency energy ratio of the yield of ozone and nitrite nitrogen and that of the removal of p-nitrophenol increased as a function of discharge energy and discharge voltage. The experimental results were fully analyzed and the chemical reaction equations and the physical processes of discharges in water were given. supported by National Natural Science Foundation of China (Nos. 11274092, 11404092, 61401146), the Nantong Science and Technology Project, Nantong, China (No. BK2014024), the Open Project of Jiangsu Province Key Laboratory of Environmental Engineering, Nanjing, China (No. KF2014001), and the Fundamental Research Funds for the Central Universities of China (No. 2014B11414)

  17. Pulsed Discharge Plasma over a Water Surface Induces Decoloration of Dyes

    NASA Astrophysics Data System (ADS)

    Wahyudiono; Machmudah, Siti; Goto, Motonobu

    2013-06-01

    It was well known that plasma can be defined as a partially ionized gas composed of ions, electrons and neutral species. Recently, plasma-water interaction has attracted growing interest as it may provide experimental chemists with a quite unique reaction medium. In this work, decoloration of dyes in water as a reaction media and the effects of various parameters with pulsed high-voltage discharge plasma are studied. Such as plasma applied under hydrothermal conditions generates high-energy electrons, ions, and radicals, which in turn may generate new reaction fields, leading to effective organic compounds oxidation for both homogeneous and heterogeneous reactions. Here, we utilize pulse discharge plasma over water surface to study the decoloration of Orange G, Orange II, Congo Red, and Naphthol Blue Black. They were directly fed as starting materials without additives. The experiments were conducted under argon atmospheric at 313 K using a batch type reactor. The products were directly analyzed by UV-Vis (ultra violet-visible) spectrophotometer V-550. The decoloration rate increased with increasing peak pulse voltage and pulse numbers, presumably due to the increased electric field energy. Based on these results, the present system may be promising.

  18. Global land-ocean linkage: direct inputs of nitrogen to coastal waters via submarine groundwater discharge

    NASA Astrophysics Data System (ADS)

    Beusen, A. H. W.; Slomp, C. P.; Bouwman, A. F.

    2013-09-01

    The role of submarine groundwater discharge (SGD), the leakage of groundwater from aquifers into coastal waters, in coastal eutrophication has been demonstrated mostly for the North American and European coastlines, but poorly quantified in other regions. Here, we present the first spatially explicit global estimates of N inputs via SGD to coastal waters and show that it has increased from about 1.0 to 1.4 Tg of nitrate (NO3-N) per year over the second half of the 20th century. Since this increase is not accompanied by an equivalent increase of groundwater phosphorus (P) and silicon (Si), SGD transport of nitrate is an important factor for the development of harmful algal blooms in coastal waters. Groundwater fluxes of N are linked to areas with high runoff and intensive anthropogenic activity on land, with Southeast Asia, parts of North and Central America, and Europe being hot spots.

  19. HIGH PERFORMANCE STATIONARY DISCHARGES IN THE DIII-D TOKAMAK

    SciTech Connect

    45th ANNUAL MEETING OF DIVISION OF PLASMA PHYSICS, ALBUQUERQUE, NEW MEXICO, OCTOBER 27-31,2003 AND TO BE PUBLISHED IN PHYS. PLASMAS.

    2003-10-01

    Recent experiments in the DIII-D tokamak [J.L. Luxon, Nucl. Fusion 42,614 (2002)] have demonstrated high {beta} with good confinement quality under stationary conditions. Two classes of stationary discharges are observed--low q{sub 95} discharges with sawteeth and higher q{sub 95} without sawteeth. The discharges are deemed stationary when the plasma conditions are maintained for times greater than the current profile relaxation time. In both cases the normalized fusion performance ({beta}{sub N}H{sub 89P}/q{sub 95}{sup 2}) reaches or exceeds the value of this parameter projected for Q{sub fus} = 10 in the International Thermonuclear Experimental Reactor (ITER) design [R. Aymar, et al., Plasma Phys. Control. Fusion 44, 519 (2002)]. The presence of sawteeth reduces the maximum achievable normalized {beta}, while confinement quality (confinement time relative to scalings) is largely independent of q{sub 95}. Even with the reduced {beta} limit, the normalized fusion performance maximizes at the lowest q{sub 95}. Projections to burning plasma conditions are discussed, including the methodology of the projection and the key physics issues which still require investigation.

  20. CASE STUDY OF A MARINE DISCHARGE: COMPARISON OF EFFLUENT AND RECEIVING WATER TOXICITY

    EPA Science Inventory

    An on-site investigation was conducted in northeast Florida to evaluate the toxicity of a pulp and paper mill discharge and to determine whether there was any receiving water toxicity associated with that discharge. The species tested included the macroalga Champia parvula, the m...

  1. Anthropogenic effects on global riverine sediment and water discharge - a spatially explicit analysis

    NASA Astrophysics Data System (ADS)

    Cohen, S.; Kettner, A. J.; Syvitski, J. P.

    2013-12-01

    Changes in global riverine water discharge and suspended sediment flux over a 50-year period, 1960-2010 are studied, applying a new version of the WBMsed (WBMsed v.2.0) global hydrological water balance model. A new floodplain component is introduced to better represent water and sediment dynamics during periods of overbank discharge. Validated against data from 16 globally distributed stations, WBMsed v.2.0 simulation results show considerable improvement over the original model. Anthropogenic impact on sediment and water discharge is evaluated by comparing global scale simulations with and without human drivers and parameters (agricultural land use, water intake form aquifers and rivers, sediment trapping in reservoirs, and human-induced soil erosion). The results show that, on average, global riverine sediment flux is reduced by approximately 25% by anthropogenic activities (almost exclusively due to trapping in reservoirs) while water discharge is reduced by about 2%. These results correspond to previous analysis by other research groups. Substantial global and intra-basin variability is observed (see Figure 1) for the first time. In some regions an opposite anthropogenic effect on sediment and water discharge was predicted (e.g. west Mississippi Basin, Rio Grande River, Indian subcontinent). We discuss the western part of the Mississippi Basin as an example of this intriguing anthropogenic impact. Figure 1. Percent change between disturbed and pristine simulations (with and without human footprint respectively) for sediment flux (top) and water discharge (bottom).

  2. Influence of Sodium Carbonate on Decomposition of Formic Acid by Discharge inside Bubble in Water

    NASA Astrophysics Data System (ADS)

    Iwabuchi, Masashi; Takahashi, Katsuyuki; Takaki, Koichi; Satta, Naoya

    2015-09-01

    An influence of sodium carbonate on decomposition of formic acid by discharge inside bubble in water was investigated. Oxygen or argon gases were injected into the water through a vertically positioned glass tube, in which the high-voltage wire electrode was placed to generate plasmas at low applied voltage. The concentration of formic acid was determined by ion chromatography. In the case of addition of sodium carbonate, the pH value increased with decomposition of the formic acid. In the case of oxygen injection, the increase of pH value contributed to improve an efficiency of the formic acid decomposition because the reaction rate of ozone and formic acid increased with increasing pH value. In the case of argon injection, the decomposition rate was not affected by the pH value owing to the high rate constants for loss of hydroxyl radicals.

  3. Habitat use by a Midwestern U.S.A. riverine fish assemblage: effects of season, water temperature and river discharge

    USGS Publications Warehouse

    Gillette, D.P.; Tiemann, J.S.; Edds, D.R.; Wildhaber, M.L.

    2006-01-01

    The hypothesis that temperate stream fishes alter habitat use in response to changing water temperature and stream discharge was evaluated over a 1 year period in the Neosho River, Kansas, U.S.A. at two spatial scales. Winter patterns differed from those of all other seasons, with shallower water used less frequently, and low-flow habitat more frequently, than at other times. Non-random habitat use was more frequent at the point scale (4.5 m2) than at the larger reach scale (20-40 m), although patterns at both scales were similar. Relative to available habitats, assemblages used shallower, swifter-flowing water as temperature increased, and shallower, slower-flowing water as river discharge increased. River discharge had a stronger effect on assemblage habitat use than water temperature. Proportion of juveniles in the assemblage did not have a significant effect. This study suggests that many riverine fishes shift habitats in response to changing environmental conditions, and supports, at the assemblage level, the paradigm of lotic fishes switching from shallower, high-velocity habitats in summer to deeper, low-velocity habitats in winter, and of using shallower, low-velocity habitats during periods of high discharge. Results also indicate that different species within temperate river fish assemblages show similar habitat use patterns at multiple scales in response to environmental gradients, but that non-random use of available habitats is more frequent at small scales. ?? 2006 The Fisheries Society of the British Isles.

  4. Produced water discharges to the Gulf of Mexico: Background information for ecological risk assessments

    SciTech Connect

    Meinhold, A.F.; Holtzman, S.; DePhillips, M.P.

    1996-06-01

    This report reviews ecological risk assessment concepts and methods; describes important biological resources in the Gulf of Mexico of potential concern for produced water impacts; and summarizes data available to estimate exposure and effects of produced water discharges. The emphasis is on data relating to produced water discharges in the central and western Gulf of Mexico, especially in Louisiana. Much of the summarized data and cited literature are relevant to assessments of impacts in other regions. Data describing effects on marine and estuarine fishes, mollusks, crustaceans and benthic invertebrates are emphasized. This review is part of a series of studies of the health and ecological risks from discharges of produced water to the Gulf of Mexico. These assessments will provide input to regulators in the development of guidelines and permits, and to industry in the use of appropriate discharge practices.

  5. Requiring Pollutant Discharge Permits for Pesticide Applications that Deposit Residues in Surface Waters

    PubMed Central

    Centner, Terence; Eberhart, Nicholas

    2014-01-01

    Agricultural producers and public health authorities apply pesticides to control pests that damage crops and carry diseases. Due to the toxic nature of most pesticides, they are regulated by governments. Regulatory provisions require pesticides to be registered and restrictions operate to safeguard human health and the environment. Yet pesticides used near surface waters pose dangers to non-target species and drinking water supplies leading some governments to regulate discharges of pesticides under pollution discharge permits. The dual registration and discharge permitting provisions are burdensome. In the United States, agricultural interest groups are advancing new legislation that would exempt pesticide residues from water permitting requirements. An analysis of the dangers posed by pesticide residues in drinking water leads to a conclusion that both pesticide registration and pollutant discharge permitting provisions are needed to protect human health and aquatic species. PMID:24814945

  6. Requiring pollutant discharge permits for pesticide applications that deposit residues in surface waters.

    PubMed

    Centner, Terence; Eberhart, Nicholas

    2014-05-01

    Agricultural producers and public health authorities apply pesticides to control pests that damage crops and carry diseases. Due to the toxic nature of most pesticides, they are regulated by governments. Regulatory provisions require pesticides to be registered and restrictions operate to safeguard human health and the environment. Yet pesticides used near surface waters pose dangers to non-target species and drinking water supplies leading some governments to regulate discharges of pesticides under pollution discharge permits. The dual registration and discharge permitting provisions are burdensome. In the United States, agricultural interest groups are advancing new legislation that would exempt pesticide residues from water permitting requirements. An analysis of the dangers posed by pesticide residues in drinking water leads to a conclusion that both pesticide registration and pollutant discharge permitting provisions are needed to protect human health and aquatic species. PMID:24814945

  7. Model-estimated ground-water recharge and hydrograph of ground-water discharge to a stream

    USGS Publications Warehouse

    Rutledge, A.T.

    1997-01-01

    The computer model PULSE, described in this report, can be used to construct a hydrograph of ground-water discharge to a stream. The model is applicable to a ground-water flow system that is driven by areally uniform recharge to the water table, and in which ground water discharges to a gaining stream. One of the two formulations used by the model allows for an instantaneous recharge pulse and subsequent ground-water discharge to the stream. The other formulation, which allows for a gradual hydrologic gain or loss term in addition to the instantaneous pulse, can be used to simulate the effects of gradual recharge to the water table, ground-water evapotranspiration, or downward leakage to a deeper aquifer.

  8. Potential water-quality effects of coal-bed methane production water discharged along the upper Tongue River, Wyoming and Montana

    USGS Publications Warehouse

    Kinsey, Stacy M.; Nimick, David A.

    2011-01-01

    Water quality in the upper Tongue River from Monarch, Wyoming, downstream to just upstream from the Tongue River Reservoir in Montana potentially could be affected by discharge of coal-bed methane (CBM) production water (hereinafter referred to as CBM discharge). CBM discharge typically contains high concentrations of sodium and other ions that could increase dissolved-solids (salt) concentrations, specific conductance (SC), and sodium-adsorption ratio (SAR) in the river. Increased inputs of sodium and other ions have the potential to alter the river's suitability for agricultural irrigation and aquatic ecosystems. Data from two large tributaries, Goose Creek and Prairie Dog Creek, indicate that these tributaries were large contributors to the increase in SC and SAR in the Tongue River. However, water-quality data were not available for most of the smaller inflows, such as small tributaries, irrigation-return flows, and CBM discharges. Thus, effects of these inflows on the water quality of the Tongue River were not well documented. Effects of these small inflows might be subtle and difficult to determine without more extensive data collection to describe spatial patterns. Therefore, synoptic water-quality sampling trips were conducted in September 2005 and April 2006 to provide a spatially detailed profile of the downstream changes in water quality in this reach of the Tongue River. The purpose of this report is to describe these downstream changes in water quality and to estimate the potential water-quality effects of CBM discharge in the upper Tongue River. Specific conductance of the Tongue River through the study reach increased from 420 to 625 microsiemens per centimeter (.μS/cm; or 49 percent) in the downstream direction in September 2005 and from 373 to 543 .μS/cm (46 percent) in April 2006. Large increases (12 to 24 percent) were measured immediately downstream from Goose Creek and Prairie Dog Creek during both sampling trips. Increases attributed to

  9. Experimental measurement of spatially resolved electron density in a filament of a pulsed positive streamer discharge in water

    SciTech Connect

    Wen, Xiao Qiong; Niu, Zhi Wen; Ren, Chun-Sheng; Hou, Bo

    2015-06-29

    By combining a high-speed frame camera with a monochromator, the spatially resolved optical emission spectrum of hydrogen α line in a single filament of a pulsed positive streamer discharge in water has been experimentally measured. The spatially resolved electron densities in a single filament of a pulsed positive streamer discharge in water with a conductivity of 200 μS/cm were investigated. During the experiment, the average energy per pulse of discharge was 90.6 ± 13.6 mJ. The results show that the electron density in the streamer filament is 10{sup 17–18}/cm{sup 3}, and present a decreasing tendency along the axial direction of the streamer filament with increasing distance from the tip of the anode.

  10. Heated Discharge Control and Management Alternatives: Small Water Bodies and Rivers.

    ERIC Educational Resources Information Center

    MacLaren, James F.

    Basic concepts of waste heat management on shallow and deep small water bodies and rivers are reviewed and examples are given. This study defines a small water body as a body in which the far field hydrothermal effects of a heated discharge can be detected in a major portion or practically all of the water body. Environmental effects due to…

  11. Ground-water discharge and nitrate loadings to the coastal bays of Maryland

    USGS Publications Warehouse

    Dillow, Jonathan J.A.; Greene, Earl A.

    1999-01-01

    Nitrate in ground water discharged to the Atlantic coastal bays of Maryland enhances the growth of phytoplankton and algae in the bays, which in turn contributes to the process of eutrophication (changes in a body of water as nutrients and sediments accumulate), which is one of the principal environmental problems in the bays. Information on nitrate loading to the bays has been identified as a major data gap by State and Federal resource managers. This report presents results of a study to estimate ground-water discharge and potential nitrate loads to the coastal bays of Maryland, which include Chincoteague, Newport, Sinepuxent, Isle of Wight, and Assawoman Bays. The nitrate load from the discharge of ground water to the coastal bays is dependent on the concentration of nitrate in the water and the volume of ground water being discharged. Data from 388 wells completed in the surficial aquifer that discharges to the bays were used to construct a map of the distribution of nitrate concentration in the ground water. On the basis of those data, and on several simplifying assumptions, the potential nitrate load to the coastal bays from direct discharge of ground water was estimated to be 272,000 pounds of nitrate per year, distributed throughout the 108-square-mile surface area of the bays. Nitrate from ground water can also enter the coastal bays by way of base flow to streams that discharge to the bays. The potential nitrate load to the bays from the base flow of streams was estimated to be 862,000 pounds per year, assuming that the concentration of nitrate in stream base flow is 3.2 milligrams per liter, which is the median concentration of nitrate in ground water in the study area.

  12. Electrodeless HID lamp study. Final report. [High intensity discharge

    SciTech Connect

    Anderson, J.M.; Johnson, P.D.; Jones, C.E.; Rautenberg, T.H.

    1985-01-01

    High intensity discharge lamps excited by solenoidal electric fields (SEF/HID) were examined for their ability to give high brightness, high efficacy and good color. Frequency of operation was 13.56 MHz (ISM Band) and power to the lamp plasma ranged from about 400 to 1000 W. Radio frequency transformers with air cores and with air core complemented by ferrite material in the magnetic path were used to provide the voltage for excitation. Electrical properties of the matching network and the lamp plasma were measured or calculated and total light from the lamp was measured by an integrating sphere. Efficacies calculated from measurement were found to agree well with the positive column efficacies of conventional HID lamps containing only mercury, and with additives of sodium, thallium, and scandium iodide. Recommendations for future work are given.

  13. Estimates of Nutrient Loading by Ground-Water Discharge into the Lynch Cove Area of Hood Canal, Washington

    USGS Publications Warehouse

    Simonds, F. William; Swarzenski, Peter W.; Rosenberry, Donald O.; Reich, Christopher D.; Paulson, Anthony J.

    2008-01-01

    field investigations show that ground-water discharge into the Lynch Cove area of Hood Canal is highly dynamic and strongly affected by the large tidal range. In areas with a steep shoreline and steep hydraulic gradient, ground-water discharge is spatially concentrated in or near the intertidal zone, with increased discharge during low tide. Topographically flat areas with weak hydraulic gradients had more spatial variability, including larger areas of seawater recirculation and more widely dispersed discharge. Measured total-dissolved-nitrogen concentrations in ground water ranged from below detection limits to 2.29 milligrams per liter and the total load entering Lynch Cove was estimated to be approximately 98 ? 10.3 metric tons per year (MT/yr). This estimate is based on net freshwater seepage rates from Lee-type seepage meter measurements and can be compared to estimates derived from geochemical tracer mass balance estimates (radon and radium) of 231 to 749 MT/yr, and previous water-mass-balance estimates (14 to 47 MT/ yr). Uncertainty in these loading estimates is introduced by complex biogeochemical cycles of relevant nutrient species, the representativeness of measurement sites, and by energetic dynamics at the coastal aquifer-seawater interface caused by tidal forcing.

  14. Suspended sediment and stream discharge in Bloody Run and Sny Magill watershed, water year 1992

    USGS Publications Warehouse

    Kalkhoff, Stephen J.; Eash, David A.

    1994-01-01

    Hydrologic data were collected in the Bloody Run and Sny Magill watersheds in Clayton County, Iowa during the 1992 Water Year (October 1, 1991 to September 30, 1992) to provide data on suspended sediment and stream discharge from these watersheds.  Suspended-sediment samples were collected daily during normal flow and several times during rainstorms.  Stream stage was recorded continuously and stream-discharge measurements were made monthly to develop a stage-discharge relation.  Data on drainage-basin morphology and precipitation were quantified to help understand the variability in sediment and stream discharge.  The total suspended-sediment discharge for Water Year 1992 was 2,720 tons at site BR1 on Bloody Run and 1,940 tons at site SN1 on Sny Magill Creek  The daily median suspended-sediment discharge was 1.1 tons at both sites BR1 and SN1.  The maximum daily mean stream discharge (205 cubic feet per second) at site BR1 on Bloody Run occurred on November 1, 1991.  The median daily discharge at BR1 for the 1992 Water year was 24 cubic feet per second or 0.70 cubic feet per second per square mile (ft3/s/mi2).  The maximum daily mean stream discharge at site SN1 on Sny Magill Creek was 90 cubic feet per second which occurred on April 20, 1992.  The median daily discharge at site SN1 for the 1992 Water Year was 15 cubic feet per second or 0.54 ft3/s/mi2.

  15. Pathogenic and nonpathogenic Acanthamoeba spp. in thermally polluted discharges and surface waters

    SciTech Connect

    de Jonckheere, J.F.

    1981-02-01

    During spring and autumn, the total number of amoebae and the number of acanthamoeba species able to grow at 37 degrees C were determined in six thermally polluted factory discharges and the surrounding surface waters. The isolated Acanthamoeba strains were studied for growth in axenic medium, cytopathic effect in Vito cell cultures, and virulence in mice. Although more amoebae were isolated in autumn, the number of Acanthamoeba species was lower than in spring, when the percent of pathogenic strains among the isolates was highest. Higher concentrations of amoebae were found in warm discharges, and more virulent strains occurred in thermal discharges than in surface waters.

  16. Estimates of ground-water discharge as determined from measurements of evapotranspiration, Ash Meadows area, Nye County, Nevada

    USGS Publications Warehouse

    Laczniak, R.J.; DeMeo, G.A.; Reiner, S.R.; Smith, Jody L.; Nylund, W.E.

    1999-01-01

    of the seven identified ET units. Micrometeorological data were collected for a minimum of 1 year at each site during 1994 through 1997. Evapotranspiration ranged from 0.6 foot per year in a sparse, dry saltgrass environment to 8.6 feet per year over open water. Ancillary data, including water levels, were collected during this same period to gain additional insight into the evapotranspiration process. Water levels measured in shallow wells showed annual declines of more than 10 feet and daily declines as high as 0.3 foot attributed to water losses associated with evapotranspiration. Mean annual ET from the Ash Meadows area is estimated at 21,000 acre-feet. An estimate of ground-water discharge, based on this ET estimate, is presented as a range to account for uncertainties in the contribution of local precipitation. The estimates given for mean annual ground-water discharge range from 18,000 to 21,000 acre-feet. The low estimate assumes a large contribution from local precipitation in computed ET rates; whereas, the high estimate assumes no contribution from local precipitation. The range presented is only slightly higher than previous estimates of ground-water discharge from the Ash Meadows area based primarily on springflow measurements.

  17. An investigation of an underwater steam plasma discharge as alternative to air plasmas for water purification

    NASA Astrophysics Data System (ADS)

    Gucker, Sarah N.; Foster, John E.; Garcia, Maria C.

    2015-10-01

    An underwater steam plasma discharge, in which water itself is the ionizing media, is investigated as a means to introduce advanced oxidation species into contaminated water for the purpose of water purification. The steam discharge avoids the acidification observed with air discharges and also avoids the need for a feed gas, simplifying the system. Steam discharge operation did not result in a pH changes in the processing of water or simulated wastewater, with the actual pH remaining roughly constant during processing. Simulated wastewater has been shown to continue to decompose significantly after steam treatment, suggesting the presence of long-lived plasma produced radicals. During steam discharge operation, nitrate production is limited, and nitrite production was found to be below the detection threshold of (roughly 0.2 mg L-1). The discharge was operated over a broad range of deposited power levels, ranging from approximately 30 W to 300 W. Hydrogen peroxide production was found to scale with increasing power. Additionally, the hydrogen peroxide production efficiency of the discharge was found to be higher than many of the rates reported in the literature to date.

  18. Magnetic shielding of Hall thrusters at high discharge voltages

    SciTech Connect

    Mikellides, Ioannis G. Hofer, Richard R.; Katz, Ira; Goebel, Dan M.

    2014-08-07

    A series of numerical simulations and experiments have been performed to assess the effectiveness of magnetic shielding in a Hall thruster operating in the discharge voltage range of 300–700 V (I{sub sp} ≈ 2000–2700 s) at 6 kW, and 800 V (I{sub sp} ≈ 3000) at 9 kW. At 6 kW, the magnetic field topology with which highly effective magnetic shielding was previously demonstrated at 300 V has been retained for all other discharge voltages; only the magnitude of the field has been changed to achieve optimum thruster performance. It is found that magnetic shielding remains highly effective for all discharge voltages studied. This is because the channel is long enough to allow hot electrons near the channel exit to cool significantly upon reaching the anode. Thus, despite the rise of the maximum electron temperature in the channel with discharge voltage, the electrons along the grazing lines of force remain cold enough to eliminate or reduce significantly parallel gradients of the plasma potential near the walls. Computed maximum erosion rates in the range of 300–700 V are found not to exceed 10{sup −2} mm/kh. Such rates are ∼3 orders of magnitude less than those observed in the unshielded version of the same thruster at 300 V. At 9 kW and 800 V, saturation of the magnetic circuit did not allow for precisely the same magnetic shielding topology as that employed during the 6-kW operation since this thruster was not designed to operate at this condition. Consequently, the maximum erosion rate at the inner wall is found to be ∼1 order of magnitude higher (∼10{sup −1} mm/kh) than that at 6 kW. At the outer wall, the ion energy is found to be below the sputtering yield threshold so no measurable erosion is expected.

  19. 77 FR 35268 - Standards for Living Organisms in Ships' Ballast Water Discharged in U.S. Waters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    ... concentration of living organisms in ships' ballast water discharged in waters of the United States (77 FR 17254). The Coast Guard also established an approval process for ballast water management systems (77 FR 17254... SECURITY Coast Guard 33 CFR Part 151 46 CFR Part 162 RIN 1625-AA32 Standards for Living Organisms in...

  20. High Rate Discharge Studies of LI/SO2 Batteries

    NASA Technical Reports Server (NTRS)

    Barnes, J. A.; Buchholz, S.; Bis, R. F.; Debold, F. C.; Kowalchik, L. A.

    1984-01-01

    A battery composed of twelve lithium/sulfur dioxide D size cells in series is forced discharged at 21 amperes. This current is established by the proposed use of the battery and represented a discharge condition which might produce venting. Discharge of the battery into voltage reversal results not only in cells venting but also in the violent rupture of at least one cell.

  1. Global model for high pressure electronegative radio-frequency discharges

    SciTech Connect

    Lee, Y.T.; Lieberman, M.A.; Lichtenberg, A.J.; Bose, F.; Baltes, H.; Patrick, R.

    1997-01-01

    We develop a global model for high pressure (0.1{endash}1 Torr) electronegative rf discharges and apply it to model a capacitively driven plasma etcher. The molecular gases considered consist of either pure chlorine species or a mixture of chlorine and helium species. The charged and neutral heavy particle densities together with the electron density and electron temperature are calculated by using the equations of particle balance and power balance for the input discharge parameters rf power or rf current, inlet pressure, gas flow rates, reactor diameter, and gap spacing. The power is deposited in the electrons via ohmic heating and in those ions accelerated across the dc sheath potential. The voltage across the sheath is calculated self-consistently with the densities and the electron temperature by using a collisional Child law sheath model. Analytic scaling laws for the dependence of charged and neutral particle densities, electron temperature, rf voltage and current, sheath width, and plasma impedance on pressure and absorbed rf power are presented and used to explain the numerical results obtained from the global model. The model results are compared to recent experimental measurements in a chlorine discharge over a range of absorbed power P{sub abs}=20{endash}180W at an inlet pressure p{sub in}=0.4 Torr and a range of pressure 0.1{endash}1.6 Torr with a fixed input power of 100 W. We obtain reasonable agreement for P{sub abs}{lt}200W and for 0.2 Torr{lt}p{sub in}{lt}1Torr. {copyright} {ital 1997 American Vacuum Society.}

  2. RF physics of ICWC discharge at high cyclotron harmonics

    NASA Astrophysics Data System (ADS)

    Lyssoivan, A.; van Eester, D.; Wauters, T.; Bobkov, V.; Vervier, M.; Douai, D.; Kogut, D.; Kreter, A.; Moiseenko, V.; Möller, S.; Noterdaeme, J.-M.; Philipps, V.; Rohde, V.; Schneider, P.; Sergienko, G.; van Schoor, M.; Textor Team, ASDEX Upgrade Team

    2014-02-01

    Recent experiments on Ion Cyclotron Wall Conditioning (ICWC) performed in tokamaks TEXTOR and ASDEX Upgrade with standard ICRF antennas operated at fixed frequencies but variable toroidal magnetic field demonstrated rather contrasting parameters of ICWC discharge in scenarios with on-axis fundamental ion cyclotron resonance (ICR) for protons,ω=ωH+, and with its high cyclotron harmonics (HCH), ω=10ωcH+ṡ HCH scenario: very high antenna coupling to low density RF plasmas (Ppl≈0.9PRF-G) and low energy Maxwellian distribution of CX hydrogen atoms with temperature TH≈350 eV. Fundamental ICR: lower antenna-plasma coupling efficiency (by factor of about 1.5 times) and generation of high energy non-Maxwellian CX hydrogen atoms (with local energy E⊥H ≥1.0 keV). In the present paper, we analyze the obtained experimental results numerically using (i) newly developed 0-D transport code describing the process of plasma production with electron and ion collisional ionization in helium-hydrogen gas mixture and (ii) earlier developed 1-D Dispersion Relation Solver accounting for finite temperature effects and collision absorption mechanisms for all plasma species in addition to conventionally examined Landau/TTPM damping for electrons and cyclotron absorption for ions. The numerical study of plasma production in helium with minor hydrogen content in low and high toroidal magnetic fields is presented. The investigation of the excitation, conversion and absorption of plasma waves as function of BT-field suggests that only fast waves (FW) may give a crucial impact on antenna coupling and characteristics of the ICWC discharge using standard poloidally polarized ICRF antennas designed to couple RF power mainly to FW. The collisional (non-resonant) absorption by electrons and ions and IC absorption by resonant ions of minor concentration in low Te plasmas is studied at fundamental ICR and its high harmonics.

  3. Characterization of fish hold effluent discharged from commercial fishing vessels into harbor waters.

    PubMed

    Albert, Ryan J; McLaughlin, Christine; Falatko, Debra

    2014-10-15

    Fish hold effluent and the effluent produced from the cleaning of fish holds may contain organic material resulting from the degradation of seafood and cleaning products (e.g., soaps and detergents). This effluent is often discharged by vessels into near shore waters and, therefore, could have the potential to contribute to water pollution in bays and estuaries. We characterized effluent from commercial fishing vessels with holds containing refrigerated seawater, ice slurry, or chipped ice. Concentrations of trace heavy metals, wet chemistry parameters, and nutrients in effluent were compared to screening benchmarks to determine if there is a reasonable potential for effluent discharge to contribute to nonattainment of water quality standards. Most analytes (67%) exceeded their benchmark concentration and, therefore, may have the potential to pose risk to human health or the environment if discharges are in significant quantities or there are many vessels discharging in the same areas. PMID:25176279

  4. Effects of high salinity wastewater discharges on unionid mussels in the Allegheny River, Pennsylvania

    USGS Publications Warehouse

    Kathleen Patnode; Hittle, Elizabeth A.; Robert Anderson; Lora Zimmerman; Fulton, John W.

    2015-01-01

    We examined the effect of high salinity wastewater (brine) from oil and natural gas drilling on freshwater mussels in the Allegheny River, Pennsylvania, during 2012. Mussel cages (N = 5 per site) were deployed at two sites upstream and four sites downstream of a brine treatment facility on the Allegheny River. Each cage contained 20 juvenile northern riffleshell mussels Epioblasma torulosa rangiana). Continuous specific conductance and temperature data were recorded by water quality probes deployed at each site. To measure the amount of mixing throughout the entire study area, specific conductance surveys were completed two times during low-flow conditions along transects from bank to bank that targeted upstream (reference) reaches, a municipal wastewater treatment plant discharge upstream of the brine-facility discharge, the brine facility, and downstream reaches. Specific conductance data indicated that high specific conductance water from the brine facility (4,000–12,000 µS/cm; mean 7,846) compared to the reference reach (103–188 µS/cm; mean 151) is carried along the left descending bank of the river and that dilution of the discharge via mixing does not occur until 0.5 mi (805 m) downstream. Juvenile northern riffleshell mussel survival was severely impaired within the high specific conductance zone (2 and 34% at and downstream of the brine facility, respectively) and at the municipal wastewater treatment plant (21%) compared to background (84%). We surveyed native mussels (family Unionidae) at 10 transects: 3 upstream, 3 within, and 4 downstream of the high specific conductance zone. Unionid mussel abundance and diversity were lower for all transects within and downstream of the high conductivity zone compared to upstream. The results of this study clearly demonstrate in situ toxicity to juvenile northern riffleshell mussels, a federally endangered species, and to the native unionid mussel assemblage located downstream of a brine discharge to the

  5. Evaluation of the potentials of humic acid removal in water by gas phase surface discharge plasma.

    PubMed

    Wang, Tiecheng; Qu, Guangzhou; Ren, Jingyu; Yan, Qiuhe; Sun, Qiuhong; Liang, Dongli; Hu, Shibin

    2016-02-01

    Degradation of humic acid (HA), a predominant type of natural organic matter in ground water and surface waters, was conducted using a gas phase surface discharge plasma system. HA standard and two surface waters (Wetland, and Weihe River) were selected as the targets. The experimental results showed that about 90.9% of standard HA was smoothly removed within 40 min's discharge plasma treatment at discharge voltage 23.0 kV, and the removal process fitted the first-order kinetic model. Roles of some active species in HA removal were studied by evaluating the effects of solution pH and OH radical scavenger; and the results presented that O3 and OH radical played significant roles in HA removal. Scanning electron microscope (SEM) and FTIR analysis showed that HA surface topography and molecular structure were changed during discharge plasma process. The mineralization of HA was analyzed by UV-Vis spectrum, dissolved organic carbon (DOC), specific UV absorbance (SUVA), UV absorption ratios, and excitation-emission matrix (EEM) fluorescence. The formation of disinfection by-products during HA sample chlorination was also identified, and CHCl3 was detected as the main disinfection by-product, but discharge plasma treatment could suppress its formation to a certain extent. In addition, approximately 82.3% and 67.9% of UV254 were removed for the Weihe River water and the Wetland water after 40 min of discharge plasma treatment. PMID:26624519

  6. Role of water and discharge mode on modulating properties in an atmospheric air MHCD jet

    NASA Astrophysics Data System (ADS)

    Liu, Kun; Wang, Chenying; Lei, Juzhang; Hu, Huimin; Zheng, Peichao; He, Wei

    2016-04-01

    A portable micro hollow cathode discharge (MHCD) device was designed in this paper to generate water-air plasma jet. The results showed that MHCD jet pattern was changed from self-pulsing discharge mode to DC mode with the increasing of voltage, and the critical voltage value of discharge mode increased with the rise of gas flow. In order to study the influences of discharge mode and water content on MHCD jet, the electrical characteristics and radicals were all measured in different conditions. We found that the length of jet decreased and temperature increased with raising water-air ratio, and during self-pulsing discharge mode, •OH content was extremely low because of the low energy of electron, but level of NO was raised with gradually increasing applied voltage. In DC mode, the results showed there was least NO content, on the other hand •OH content increased with rise of voltage and water-air ratio. O existed in both discharge modes and the effect of water content on the O production was complex. Contribution to the Topical Issue "Recent Breakthroughs in Microplasma Science and Technology", edited by Kurt Becker, Jose Lopez, David Staack, Klaus-Dieter Weltmann and Wei Dong Zhu.

  7. 21 CFR 1040.30 - High-intensity mercury vapor discharge lamps.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false High-intensity mercury vapor discharge lamps. 1040...-intensity mercury vapor discharge lamps. (a) Applicability. The provisions of this section apply to any high-intensity mercury vapor discharge lamp that is designed, intended, or promoted for illumination purposes...

  8. 21 CFR 1040.30 - High-intensity mercury vapor discharge lamps.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false High-intensity mercury vapor discharge lamps. 1040...-intensity mercury vapor discharge lamps. (a) Applicability. The provisions of this section apply to any high-intensity mercury vapor discharge lamp that is designed, intended, or promoted for illumination purposes...

  9. 21 CFR 1040.30 - High-intensity mercury vapor discharge lamps.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false High-intensity mercury vapor discharge lamps. 1040...-intensity mercury vapor discharge lamps. (a) Applicability. The provisions of this section apply to any high-intensity mercury vapor discharge lamp that is designed, intended, or promoted for illumination purposes...

  10. Ionization front in a high-current gas discharge

    NASA Astrophysics Data System (ADS)

    Choueiri, Edgar Y.; Randolph, Thomas M.

    2007-02-01

    Spectroscopic measurements of ion/neutral density ratio profiles are made inside the high-current, low-pressure discharge of a coaxial magnetoplasmadynamic thruster and show the existence of a thin ionization front, upstream in the discharge, that effectively ionizes the incoming gas to ionization levels above 50%. The measurements allow an estimate of the width of this ionization front to be on the order of a few millimeters. Due to the known existence of microturbulence in the plasma, which can produce suprathermal electrons, an explanation of the measurements based on the existence of a suprathermal tail in the electron energy distribution function is sought. A theoretical model for the width of the ionization front is combined with a multilevel excitation model for argon and shows that a Maxwellian electron distribution function cannot account for the small length scale of the ionization front, and that the latter is more consistent with an electron distribution function having a suprathermal population, the magnitude of which is estimated by comparing the model to the experiments.

  11. Ionization front in a high-current gas discharge

    SciTech Connect

    Choueiri, Edgar Y.; Randolph, Thomas M.

    2007-03-15

    Spectroscopic measurements of ion/neutral density ratio profiles are made inside the high-current, low-pressure discharge of a coaxial magnetoplasmadynamic thruster and show the existence of a thin ionization front, upstream in the discharge, that effectively ionizes the incoming gas to ionization levels above 50%. The measurements allow an estimate of the width of this ionization front to be on the order of a few millimeters. Due to the known existence of microturbulence in the plasma, which can produce suprathermal electrons, an explanation of the measurements based on the existence of a suprathermal tail in the electron energy distribution function is sought. A theoretical model for the width of the ionization front is combined with a multilevel excitation model for argon and shows that a Maxwellian electron distribution function cannot account for the small length scale of the ionization front, and that the latter is more consistent with an electron distribution function having a suprathermal population, the magnitude of which is estimated by comparing the model to the experiments.

  12. USDOE study: Human health and ecological risk assessment for produced water discharges

    SciTech Connect

    Meinhold, A.F.; Holtzman, S.; DePhillips, M.; Hamilton, L.D.

    1994-12-31

    Produced water generated during the production of oil and gas can contain high concentrations of radionuclides, organics and heavy metals. There are concerns about potential human health and ecological impacts from the discharge of these contaminants to the Gulf of Mexico. Data collected in the United States Department of Energy (USDOE) field study are being used in a series of human health and ecological risk assessments. These assessments will support scientifically-based regulation and risk management. This presentation: summarizes risk assessments performed for produced water discharges; describes how uncertainties in these assessments are guiding data collection efforts in the USDOE field study; and outlines ongoing risk assessment studies. In these studies, risk assessment is treated as an iterative process. An initial screening-level assessment is performed to identify important contaminants, transport and exposure pathways, and parameters. These intermediate results are used to guide data collection efforts and refinements to the analysis. At this stage in the analysis, risk is described in terms of probabilities; the uncertainties in each measured or modeled parameter are considered explicitly.

  13. Pulsed positive streamer discharges in air at high temperatures

    NASA Astrophysics Data System (ADS)

    Ono, Ryo; Kamakura, Taku

    2016-08-01

    Atmospheric-pressure air pulsed positive streamer discharges are generated in a 13 mm point-plane gap in the temperature range of 293 K–1136 K, and the effect of temperature on the streamer discharges is studied. When the temperature is increased, the product of applied voltage and temperature VT proportional to the reduced electric field can be used as a primary parameter that determines some discharge parameters regardless of temperature. For a given VT, the transferred charge per pulse, streamer diameter, product of discharge energy and temperature, and length of secondary streamer are almost constant regardless of T, whereas the streamer velocity decreases with increasing T and the decay rate of the discharge current is proportional to 1/T. The N2(C) emission intensity is approximately determined by the discharge energy independent of T. These results are useful to predict the streamer discharge and its reactive species production when the ambient temperature is increased.

  14. Spatial and temporal distributions of toxicity in receiving waters around an oil effluent discharge site

    SciTech Connect

    Krause, P.R.

    1994-12-31

    Distributions of pollutants from a point source discharge within the water column may vary in both time and space. In this study, they examined the spatial and temporal patterns of toxicity from an oil production effluent (produced water) discharge plume using sea urchin fertilization and development bioassays. Specifically, they tested the sensitivity and response patterns of sea urchin gametes and early life stages exposed to receiving waters sampled along a 1 km transact near an active produced water outfall. Fertilization success and development of larvae to the pluteus stage varied significantly with proximity to the outfall, with reduced fertilization and larval development found closer to the outfall. Although estimated toxicity in receiving water samples, based on fertilization success, was variable in time -- perhaps responding to variation in the quantity or make-up of produced water discharges -- the general spatial pattern of toxicity along the sampling transact remained relatively constant. Strong evidence that field toxicity was directly attributable to produced water effluents was provided by sampling the receiving waters while the produced water discharge was not operating. At such a time, no toxicity was found at any of the field sites. Receiving water toxicity data, along with toxicity data from the effluent itself, were used to prepare a ``map`` of effective effluent concentrations along the sampling transect.

  15. Best Management Practices (BMP) plan for potable water discharges Y-12 Plant

    SciTech Connect

    Wiest, M.C. Jr.

    1995-07-01

    This plan provides guidance to minimize the environmental effects from discharges of chlorinated waters, including: Flushing of potable water lines; Releases from fire hydrants during testing and maintenance of fire protection systems; Releases from sprinkler systems for maintenance or testing purposes; and Other significant releases of chlorinated water. This BMP plan is intended to meet the Y-12 Plant National Pollutant Discharge Elimination System (NPDES) permit condition, requiring that BWs be used for flushing potable water lines and similar activities. Close adherence to the steps provided in this plan will help prevent the discharge of chlorinated waters ``in concentrations sufficient to be hazardous or otherwise detrimental to humans, livestock, wildlife, plant life, or fish and aquatic life in the receiving stream``.

  16. Temporal variability of the non-steady contribution from glaciers to water discharge in western Austria

    NASA Astrophysics Data System (ADS)

    Lambrecht, Astrid; Mayer, Christoph

    2009-10-01

    SummaryA long series of negative glacier mass balance years during the last decades influenced the run-off characteristics of glacierized catchments in the Austrian Alps. For balanced conditions, run-off from catchments containing glaciers shows increased values for warm and dry periods, but the annual sum generally equals the total basin precipitation. In contrast, the recent series of negative glacier mass balances reduced the storage volume of the glaciers, providing additional water in the rivers for many years. The existing Austrian Glacier Inventories allowed the determination of very accurate glacier volume changes between 1969 and 1998. These data were used to calculate the excess discharge for two catchment basins in western Austria (one unaffected by hydro power management, one with hydropower management) for the time period between the inventories which then was compared to the accumulated river run-off from the individual basins. The inter-annual distribution of the total excess could be determined by using existing mass balance series from several glaciers in the different basins as scaling functions. In addition, a degree-day approach was used to provide information about the role of above-average glacial melt water on a monthly basis. Considering different gauging stations along the rivers, it was found that the amount of excess discharge during the entire period was in the range of 1.5-9% of the total discharge, depending on the relative degree of glacier coverage (4-40%). For summer months only, this fraction increases to 3-12%. In individual months, however, the relative importance of excess melt can reach more than 25% in a highly glacier covered catchment (40%), but it can also contribute up to 20% for catchments with a glacier coverage of 8-15%.

  17. Ground water discharge by evapotranspiration in wetlands of an arid intermountain basin

    NASA Astrophysics Data System (ADS)

    Sanderson, John S.; Cooper, David J.

    2008-04-01

    SummaryTo improve basin-scale modeling of ground water discharge by evapotranspiration (ET) in relation to water table depth, daily ET was measured using the Bowen ratio energy balance method during 1999-2005 in five herbaceous plant dominated wetlands in an arid intermountain basin in Colorado, USA. Three wetlands were wet meadows supplied primarily by regional ground water flow and two were playas supplied primarily by local stream flow. In wet meadows, mean daily water table depth (WTD) ranged from 0.00 m (ground surface) to 1.2 m, with low inter-annual variability. In wet meadows, annual actual ET (ET a) was 751-994 mm, and ground water discharge from the shallow aquifer (ET g) was 75-88% of ET a. In playas, mean daily WTD ranged from -0.65 to 1.89 m, with high inter-annual variability. In playas, annual ET a was 352-892 mm, and ET g was 0-77% of ET a. The relationship of annual ET g to WTD was compared to existing ET g-WTD models. For wet meadows, ET g decreased exponentially as WTD increased from 0.13 to 0.95 m ( r2 = 0.83, CV = 5%, p < 0.001). In comparison with our findings, existing models under- and over-estimate ET g by -30% to 47% at WTD of 0.13 m, and they under-estimate ET g by -12% to -42% at WTD of 0.95 m. This study found that as the water table declined from near the soil surface to 0.95 m, ET g decreased only ˜26% versus 39-55% estimated by existing models. The magnitude of ET g decrease was 220 mm, whereas existing models predicted decreases up to 700 mm (218% greater). In playas, there was no clear ET g-WTD relationship. Instead, ET g was strongly dependent on the surface water supply. When sufficient surface water inputs occurred to meet ET demand, ET g was ≈0 mm/yr and independent of WTD. When inputs did not meet ET demand, ET g was positive though highly variable at WTD up to 1.68 m.

  18. Mineral water discharges at the Azores archipelago (Portugal): hydrogeological setting, chemical composition and mapping

    NASA Astrophysics Data System (ADS)

    Freire, P.; Cruz, J.; Coutinho, R.; Costa, A.; Antunes, P.

    2009-04-01

    The geological setting of the Azores archipelago, located in the North Atlantic ocean, about 1500 km form Portugal mainland and made of 9 islands of volcanic origin, enhances the multiplicity of surface hydrothermal manifestations. Therefore, a field survey made possible to identify 101 mineral water discharges in the Azores, mainly of CO2-rich cold waters and thermal waters, spread along São Miguel (75%), Terceira (6%), Graciosa (7%), Pico (2%), Faial (3%), São Jorge (5%) and Flores ( 2%) islands, as well as fumarolic grounds. Furnas and Fogo central volcanoes, two of the three composite active volcanoes that dominates the geology of São Miguel, the largest island of the archipelago, represent respectively about 41% and 24% of the discharges from the Azores. Discharges are mainly from fissured aquifers, made of basaltic or trachitic lava flows. Instead, discharges from porous aquifers, made of pyroclastic deposits, mainly of pumice type, are less common, and are more frequent at São Miguel island. The studied discharges correspond mainly to springs (75), and also to boiling pools (10), at fumarolic grounds, 14 drilled wells and 2 large-diameter wells. The boiling pools are only observable at São Miguel island, while drilled wells were made at São Miguel, Terceira and Graciosa. Groundwater at Azores occurs in two major aquifers systems: (1) the basal aquifer system, which corresponds to fresh-water lenses floating on underlying salt water, and (2) in perched-water bodies. The basal aquifer system is in the coastal area, presenting generally a very low hydraulic gradient. From the 14 drilled wells only two are in perched-water bodies. Considering mineral springs, the majority discharge from perched-water bodies (77%), while all the boiling pools also discharge in altitude, also from perched -water bodies. During the field survey an extensive campaign of sample collection was made in all islands, in order to characterize the chemical composition of these waters

  19. Unsaturated zone hydrology and cave drip discharge water response: Implications for speleothem paleoclimate record variability

    NASA Astrophysics Data System (ADS)

    Markowska, Monika; Baker, Andy; Treble, Pauline C.; Andersen, Martin S.; Hankin, Stuart; Jex, Catherine N.; Tadros, Carol V.; Roach, Regina

    2015-10-01

    High-frequency, spatially-dense discharge monitoring was conducted over fifteen months to characterise unsaturated zone flow at Harrie Wood Cave (HWC), in the Snowy Mountains, Yarrangobilly (SE Australia). The cave was formed in the Late Silurian Yarrangobilly Limestone, a fractured rock associated with very low primary porosity due to past diagenesis. Over our monitoring period we simultaneously measured rainfall, soil moisture saturation and drip discharge rate at fourteen sites to characterise infiltration-discharge relationships. All drip discharge sites exhibited non-Gaussian distributions, indicating long periods where low discharge predominates, punctuated by short infrequent periods of high discharge. However, there was significant variability in discharge between sites and consequently no spatial correlation in the cave. We investigated the depth-discharge relationship at HWC and found a moderate relationship between depth and drip discharge lag (response) times to soil moisture content, but only weak relationships between depth and mean and maximum discharge. This highlights that the karst architecture plays an important role in controlling drip discharge dynamics. Principal Component Analysis (PCA) and Agglomerative Hierarchal Clustering (AHC) were used to classify similar drip types, revealing five unique drip regimes. Two-phase flow and non-linear response to recharge behaviour were observed, suggesting secondary porosity is controlling unsaturated zone flow in mature limestone environments with low primary porosity. Using the data presented here, the first coupled conceptual and box hydrological flow model was developed. This study highlights the heterogeneous nature of hydrological flow in karst and the need to understand unsaturated zone hydrology at the individual drip discharge level, to inform speleothem studies for high-resolution paleoclimate reconstruction.

  20. Late quaternary history and uranium isotopic compositions of ground water discharge deposits, Crater Flat, Nevada

    SciTech Connect

    Paces, J.B.; Taylor, E.M.; Bush, C.

    1993-12-31

    Three carbonate-rich spring deposits are present near the southern end of Crater Flat, NV, approximately 18 km southwest of the potential high-level waste repository at Yucca Mountain. We have analyzed five samples of carbonate-rich material from two of the deposits for U and Th isotopic compositions. Resulting U-series disequilibrium ages indicate that springs were active at 18 {+-} 1, 30 {+-} 3, 45 {+-} 4 and >70 ka. These ages are consistent with a crude internal stratigraphy at one site. Identical ages for two samples at two separate sites suggest that springs were contemporaneous, at least in part, and were most likely part of the same hydrodynamic system. In addition, initial U isotopic compositions range from 2.8 to 3.8 and strongly suggest that ground water from the regional Tertiary-volcanic aquifer provided the source for these hydrogenic deposits. This interpretation, along with water level data from near-by wells suggest that the water table rose approximately 80 to 115 m above present levels during the late Quaternary and may have fluctuated repeatedly. Current data are insufficient to allow reconstruction of a detailed depositional history, however geochronological data are in a good agreement with other paleoclimatic proxy records preserved throughout the region. Since these deposits are down gradient from the potential repository site, the possibility of higher ground water levels in the future dramatically shortens both vertical and lateral ground water pathways and reduces travel times of transported radionuclides to potential discharge sites.

  1. Shock wave generated by high-energy electric spark discharge

    NASA Astrophysics Data System (ADS)

    Liu, Qingming; Zhang, Yunming

    2014-10-01

    Shock wave generated by electric spark discharge was studied experimentally and the shock wave energy was evaluated in this paper. A pressure measurement system was established to study the pressure field of the electric spark discharge process. A series of electric spark discharge experiments were carried out and the energy of the electric spark used in present study was in the range of 10 J, 100 J, and 1000 J, respectively. The shock wave energy released from the electric spark discharge process was calculated by using the overpressure values at different measurement points near the electric spark discharge center. The good consistency of shock wave energies calculated by pressure histories at different measuring points in the same electric spark discharge experiment illustrates the applicability of the weak shock wave theory in calculating the energy of shock wave induced by electric spark discharge process. The result showed that shock wave formed at the initial stage of electric spark discharge process, and the shock wave energy is only a little part of electric spark energy. From the analysis of the shock wave energy and electric spark energy, a good linear relationship between shock wave energy and electric spark energy was established, which make it possible to calculate shock wave energy by measuring characteristic parameters of electric spark discharge process instead of shock wave. So, the initiation energy of direct initiation of detonation can be determined easily by measuring the parameters of electric spark discharge process.

  2. Assessing hazards due to contaminant discharge in coastal waters

    NASA Astrophysics Data System (ADS)

    Churchill, J. H.

    1987-02-01

    Models of contaminant dispersion in the marine environment have mostly sought to determine the mean concentration field. At a location not far from a pollution source, concentration is intermittently high, depending on whether the site is immersed in the concentrated contaminant plume which emanates from the source. At such a locale the probability of immersion, denoted by visitation frequency, is a more meaningful measure of nuisance than mean concentration. Two methods of computing visitation frequency from moored current meter data, each having particular advantages and drawbacks, are presented. One technique estimates visitation frequency from probability distributions of the position and velocity of water parcels originating from the effluent source. The second method entails simulating the configuration and movement of a contaminant plume. Required by both schemes is the plume cross-axial width as a function of time since release. A simple procedure of approximating this using the results of dye diffusion studies is described. These methods are applied to the coastal region off Long Island, New York, where current meter and dye diffusion data are available.

  3. Prediction of diffuse sulfate emissions from a former mining district and associated groundwater discharges to surface waters

    NASA Astrophysics Data System (ADS)

    Graupner, Bastian J.; Koch, Christian; Prommer, Henning

    2014-05-01

    Rivers draining mining districts are often affected by the diffuse input of polluted groundwaters. The severity and longevity of the impact depends on a wide range of factors such as the source terms, the hydraulic regime, the distance between pollutant sources and discharge points and the dilution by discharge from upstream river reaches. In this study a deterministic multi-mine life-cycle model was developed. It is used to characterize pollutant sources and to quantify the resulting current and future effects on both groundwater and river water quality. Thereby sulfate acts as proxy for mining-related impacts. The model application to the Lausitz mining district (Germany) shows that the most important factors controlling concentrations and discharge of sulfate are mixing/dilution with ambient groundwater and the rates of biological sulfate reduction during subsurface transport. In contrast, future impacts originating from the unsaturated zones of the mining dumps showed to be of little importance due to the high age of the mining dumps and the associated depletion in reactive iron-sulfides. The simulations indicate that currently the groundwater borne diffuse input of sulfate into the rivers Kleine Spree and Spree is ∼2200 t/years. Our predictions suggest a future increase to ∼11,000 t/years within the next 40 years. Depending on river discharge rates this represents an increase in sulfate concentration of 40-300 mg/L. A trend reversal for the surface water discharge is not expected before 2050.

  4. Estimated ground-water discharge by evapotranspiration, Ash Meadows Area, Nye County, Nevada, 1994

    SciTech Connect

    Nichols, W.D.; Laczniak, R.J.; DeMeo, G.A.; Rapp, T.R.

    1997-05-01

    Ground water discharges from the regional ground-water flow system that underlies the eastern part of the Nevada Test Site through numerous springs and seeps in the Ash Meadows National Wildlife Refuge in southern Nevada. The total spring discharge was estimated to be about 17,000 acre-feet per year by earlier studies. Previous studies estimated that about 10,500 acre-feet of this discharge was lost to evapotranspiration. The present study was undertaken to develop a more rigorous approach to estimating ground-water discharge in the Ash Meadows area. Part of the study involves detailed field investigation of evapotranspiration. Data collection began in early 1994. The results of the first year of study provide a basis for making preliminary estimates of ground-water discharge by evapotranspiration. An estimated 13,100 acre-feet of ground water was evapotranspired from about 6,800 acres of marsh and salt-grass. Additional 3,500 acre-feet may have been transpired from the open water and from about 1,460 acres of other areas of Ash Meadows in which field studies have not yet been made.

  5. High-pressure dc glow discharges in hollow diamond cathodes

    NASA Astrophysics Data System (ADS)

    Truscott, B. S.; Turner, C.; May, P. W.

    2016-04-01

    We report the generation and characterization of dc helium microdischarges at several times atmospheric pressure in monolithic diamond hollow-cathode devices having cavity diameters on the order of 100 μm. I-V characteristics indicated operation in the glow discharge regime even at nearly 10 atm, while spectroscopic measurements of the N2 C3Πu  →  B3Πg emission returned rotational temperatures always around 420 K, with a pressure-dependent vibrational population distribution. The variation of breakdown voltage with pressure closely followed Paschen’s law, but with offsets in both axes that we tentatively ascribe to strong diffusive loss and a partial thermalization of electron energies under the high pressures considered here.

  6. A modified resistance equation for modeling underwater spark discharge with salinity and high pressure conditions

    SciTech Connect

    Zhao, Pengfei; Roy, Subrata

    2014-05-07

    This work investigates the performance of underwater spark discharge relating to bubble growth and decay under high pressure and with salinity conditions by introducing a modified form of the resistance equation. Here, we study salinity influence on circuit parameters by fitting the experimental data for which gap resistance is much larger in conductive water than in dielectric water. Accordingly, the resistance equation is modified by considering the influence of both plasma and its surrounding liquid. Thermal radiation effect of the bubble is also studied by comparing two different radiation models. Numerical results predict a larger bubble pressure for saline water but a reduced size and a smaller bubble cycle at a greater water depth. Such study may be useful in many saltwater applications, including that for deep sea conditions.

  7. Effects of air transient spark discharge and helium plasma jet on water, bacteria, cells, and biomolecules.

    PubMed

    Hensel, Karol; Kučerová, Katarína; Tarabová, Barbora; Janda, Mário; Machala, Zdenko; Sano, Kaori; Mihai, Cosmin Teodor; Ciorpac, Mitică; Gorgan, Lucian Dragos; Jijie, Roxana; Pohoata, Valentin; Topala, Ionut

    2015-01-01

    Atmospheric pressure DC-driven self-pulsing transient spark (TS) discharge operated in air and pulse-driven dielectric barrier discharge plasma jet (PJ) operated in helium in contact with water solutions were used for inducing chemical effects in water solutions, and the treatment of bacteria (Escherichia coli), mammalian cells (Vero line normal cells, HeLa line cancerous cells), deoxyribonucleic acid (dsDNA), and protein (bovine serum albumin). Two different methods of water solution supply were used in the TS: water electrode system and water spray system. The effects of both TS systems and the PJ were compared, as well as a direct exposure of the solution to the discharge with an indirect exposure to the discharge activated gas flow. The chemical analysis of water solutions was performed by using colorimetric methods of UV-VIS absorption spectrophotometry. The bactericidal effects of the discharges on bacteria were evaluated by standard microbiological plate count method. Viability, apoptosis and cell cycle were assessed in normal and cancerous cells. Viability of cells was evaluated by trypan blue exclusion test, apoptosis by Annexin V-FITC/propidium iodide assay, and cell cycle progression by propidium iodide/RNase test. The effect of the discharges on deoxyribonucleic acid and protein were evaluated by fluorescence and UV absorption spectroscopy. The results of bacterial and mammalian cell viability, apoptosis, and cell cycle clearly show that cold plasma can inactivate bacteria and selectively target cancerous cells, which is very important for possible future development of new plasma therapeutic strategies in biomedicine. The authors found that all investigated bio-effects were stronger with the air TS discharge than with the He PJ, even in indirect exposure. PMID:25947389

  8. EFFECTS OF THERMAL DISCHARGES ON PHYSICO-CHEMICAL PROCESSES AND WATER QUALITY, VISTULA RIVER, POLAND

    EPA Science Inventory

    A study on the influence of thermal water discharge from the Koezienice power plant on thermal regimes and water quality of the Vistula River was carried out between January 1973 and December 1975. Results of field survey of the thermal plume indicate that under non-extreme condi...

  9. 33 CFR 151.2040 - Discharge of ballast water in extraordinary circumstances.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... requirements of 33 CFR 151.1515. (b) If the installed BWMS required by this subpart stops operating properly... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Discharge of ballast water in... OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES,...

  10. 33 CFR 151.2040 - Discharge of ballast water in extraordinary circumstances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements of 33 CFR 151.1515. (b) If the installed BWMS required by this subpart stops operating properly... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Discharge of ballast water in... OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES,...

  11. 33 CFR 151.2040 - Discharge of ballast water in extraordinary circumstances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements of 33 CFR 151.1515. (b) If the installed BWMS required by this subpart stops operating properly... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Discharge of ballast water in... OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES,...

  12. Application of Microsecond Voltage Pulses for Water Disinfection by Diaphragm Electric Discharge

    NASA Astrophysics Data System (ADS)

    Kakaurov, S. V.; Suvorov, I. F.; Yudin, A. S.; Solovyova, T. L.; Kuznetsova, N. S.

    2015-11-01

    The paper presents the dependence of copper and silver ions formation on the duration of voltage pulses of diaphragm electric discharge and on the pH of treated liquid medium. Knowing it allows one to create an automatic control system to control bactericidal agent's parameters obtained in diaphragm electric discharge reactor. The current-voltage characteristic of the reactor with a horizontal to the diaphragm membrane water flow powered from the author's custom pulse voltage source is also presented. The results of studies of the power consumption of diaphragm electric discharge depending on temperature of the treated liquid medium are given.

  13. Plutonium discharges to the sanitary sewer: Health impacts at the Livermore Water Reclamation Plant

    SciTech Connect

    Balke, B.K.

    1993-04-16

    The Lawrence Livermore National Laboratory (LLNL) is the largest discharger of sewage treated by the Livermore Water Reclamation (LWRP), contributing approximately 7% by volume of the LWRP influent LILNL operations, as potential sources both of industrial pollutants and radioactivity, are therefore of particular concern to the LWRP. For this reason, LLNL has maintained vigorous wastewater discharge control and monitoring programs. In particular, the monitoring program has demonstrated that, except in a few rare instances, the concentration of contaminants in LLNL effluent have always remained below the appropriate regulatory standards. The exceptions have generally been due to inadvertent discharges of metals-bearing solutions produced by metal plating or cleaning operations.

  14. Gas-discharge probe microscopy of water-carrying channels in wood

    NASA Astrophysics Data System (ADS)

    Ivanov-Omskii, V. I.; Ivanova, E. I.

    2012-04-01

    We have used a gas-discharge imaging technique to study the water transport channels (tracheids) in wood samples. Results obtained for the samples of bitch and aspen show features of this variant of the probe microscopy and show its additional possibilities as compared to optical microscopy. It is concluded that gas-discharge probe microscopy can be used for additional diagnostics of the structure of plant and animal tissues.

  15. RF physics of ICWC discharge at high cyclotron harmonics

    SciTech Connect

    Lyssoivan, A.; Van Eester, D.; Wauters, T.; Vervier, M.; Van Schoor, M.; Bobkov, V.; Rohde, V.; Schneider, P.; Douai, D.; Kogut, D.; Kreter, A.; Möller, S.; Philipps, V.; Sergienko, G.; Moiseenko, V.; Noterdaeme, J.-M.; Collaboration: TEXTOR Team; ASDEX Upgrade Team

    2014-02-12

    Recent experiments on Ion Cyclotron Wall Conditioning (ICWC) performed in tokamaks TEXTOR and ASDEX Upgrade with standard ICRF antennas operated at fixed frequencies but variable toroidal magnetic field demonstrated rather contrasting parameters of ICWC discharge in scenarios with on-axis fundamental ion cyclotron resonance (ICR) for protons,ω=ω{sub H+}, and with its high cyclotron harmonics (HCH), ω=10ω{sub cH+}⋅ HCH scenario: very high antenna coupling to low density RF plasmas (P{sub pl}≈0.9P{sub RF-G}) and low energy Maxwellian distribution of CX hydrogen atoms with temperature T{sub H}≈350 eV. Fundamental ICR: lower antenna-plasma coupling efficiency (by factor of about 1.5 times) and generation of high energy non-Maxwellian CX hydrogen atoms (with local energy E{sub ⊥H} ≥1.0 keV). In the present paper, we analyze the obtained experimental results numerically using (i) newly developed 0-D transport code describing the process of plasma production with electron and ion collisional ionization in helium-hydrogen gas mixture and (ii) earlier developed 1-D Dispersion Relation Solver accounting for finite temperature effects and collision absorption mechanisms for all plasma species in addition to conventionally examined Landau/TTPM damping for electrons and cyclotron absorption for ions. The numerical study of plasma production in helium with minor hydrogen content in low and high toroidal magnetic fields is presented. The investigation of the excitation, conversion and absorption of plasma waves as function of B{sub T}-field suggests that only fast waves (FW) may give a crucial impact on antenna coupling and characteristics of the ICWC discharge using standard poloidally polarized ICRF antennas designed to couple RF power mainly to FW. The collisional (non-resonant) absorption by electrons and ions and IC absorption by resonant ions of minor concentration in low T{sub e} plasmas is studied at fundamental ICR and its high harmonics.

  16. 77 FR 17253 - Standards for Living Organisms in Ships' Ballast Water Discharged in U.S. Waters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ... Environmental Impact Statement FR final rule GRT gross register tons GSI Great Ships Initiative GT gross tons... Water Discharged in U.S. Waters'' in the Federal Register (74 FR 44632). In response, we received 662... requiring Coast Guard approval. 44 FR 73038 (December 17, 1979). The Coast Guard promulgated 46 CFR part...

  17. 77 FR 33969 - Standards for Living Organisms in Ships' Ballast Water Discharged in U.S. Waters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-08

    ... FR 17254), entitled ``Standards for Living Organisms in Ships' Ballast Water Discharged in U.S... March 23, 2012 (77 FR 17254), entitled ``Standards for Living Organisms in Ships' Ballast Water... Standards Directorate''. Notification should be provided to U.S. Coast Guard Marine Safety Center. In FR...

  18. The effects of precipitation, river discharge, land use and coastal circulation on water quality in coastal Maine

    PubMed Central

    Tilburg, Charles E.; Jordan, Linda M.; Carlson, Amy E.; Zeeman, Stephan I.; Yund, Philip O.

    2015-01-01

    Faecal pollution in stormwater, wastewater and direct run-off can carry zoonotic pathogens to streams, rivers and the ocean, reduce water quality, and affect both recreational and commercial fishing areas of the coastal ocean. Typically, the closure of beaches and commercial fishing areas is governed by the testing for the presence of faecal bacteria, which requires an 18–24 h period for sample incubation. As water quality can change during this testing period, the need for accurate and timely predictions of coastal water quality has become acute. In this study, we: (i) examine the relationship between water quality, precipitation and river discharge at several locations within the Gulf of Maine, and (ii) use multiple linear regression models based on readily obtainable hydrometeorological measurements to predict water quality events at five coastal locations. Analysis of a 12 year dataset revealed that high river discharge and/or precipitation events can lead to reduced water quality; however, the use of only these two parameters to predict water quality can result in a number of errors. Analysis of a higher frequency, 2 year study using multiple linear regression models revealed that precipitation, salinity, river discharge, winds, seasonality and coastal circulation correlate with variations in water quality. Although there has been extensive development of regression models for freshwater, this is one of the first attempts to create a mechanistic model to predict water quality in coastal marine waters. Model performance is similar to that of efforts in other regions, which have incorporated models into water resource managers' decisions, indicating that the use of a mechanistic model in coastal Maine is feasible. PMID:26587258

  19. The effects of precipitation, river discharge, land use and coastal circulation on water quality in coastal Maine.

    PubMed

    Tilburg, Charles E; Jordan, Linda M; Carlson, Amy E; Zeeman, Stephan I; Yund, Philip O

    2015-07-01

    Faecal pollution in stormwater, wastewater and direct run-off can carry zoonotic pathogens to streams, rivers and the ocean, reduce water quality, and affect both recreational and commercial fishing areas of the coastal ocean. Typically, the closure of beaches and commercial fishing areas is governed by the testing for the presence of faecal bacteria, which requires an 18-24 h period for sample incubation. As water quality can change during this testing period, the need for accurate and timely predictions of coastal water quality has become acute. In this study, we: (i) examine the relationship between water quality, precipitation and river discharge at several locations within the Gulf of Maine, and (ii) use multiple linear regression models based on readily obtainable hydrometeorological measurements to predict water quality events at five coastal locations. Analysis of a 12 year dataset revealed that high river discharge and/or precipitation events can lead to reduced water quality; however, the use of only these two parameters to predict water quality can result in a number of errors. Analysis of a higher frequency, 2 year study using multiple linear regression models revealed that precipitation, salinity, river discharge, winds, seasonality and coastal circulation correlate with variations in water quality. Although there has been extensive development of regression models for freshwater, this is one of the first attempts to create a mechanistic model to predict water quality in coastal marine waters. Model performance is similar to that of efforts in other regions, which have incorporated models into water resource managers' decisions, indicating that the use of a mechanistic model in coastal Maine is feasible. PMID:26587258

  20. Density matters: Approaches to settling ballast water discharge concentrations

    EPA Science Inventory

    A consensus has evolved that invasion risk increases with propagule pressure. However, translating this general principal into ecologically “acceptable” concentrations of organisms in ballast water has proven challenging. The treaty being promulgated by the International Maritime...

  1. Ballast water regulations and the move toward concentration-based numeric discharge limits.

    PubMed

    Albert, Ryan J; Lishman, John M; Saxena, Juhi R

    2013-03-01

    Ballast water from shipping is a principal source for the introduction of nonindigenous species. As a result, numerous government bodies have adopted various ballast water management practices and discharge standards to slow or eliminate the future introduction and dispersal of these nonindigenous species. For researchers studying ballast water issues, understanding the regulatory framework is helpful to define the scope of research needed by policy makers to develop effective regulations. However, for most scientists, this information is difficult to obtain because it is outside the standard scientific literature and often difficult to interpret. This paper provides a brief review of the regulatory framework directed toward scientists studying ballast water and aquatic invasive species issues. We describe different approaches to ballast water management in international, U.S. federal and state, and domestic ballast water regulation. Specifically, we discuss standards established by the International Maritime Organization (IMO), the U.S. Coast Guard and U.S. Environmental Protection Agency, and individual states in the United States including California, New York, and Minnesota. Additionally, outside the United States, countries such as Australia, Canada, and New Zealand have well-established domestic ballast water regulatory regimes. Different approaches to regulation have recently resulted in variations between numeric concentration-based ballast water discharge limits, particularly in the United States, as well as reliance on use of ballast water exchange pending development and adoption of rigorous science-based discharge standards. To date, numeric concentration-based discharge limits have not generally been based upon a thorough application of risk-assessment methodologies. Regulators, making decisions based on the available information and methodologies before them, have consequently established varying standards, or not established standards at all. The

  2. Effect of Oxygen Gas on the Decomposition of Dye by Pulsed Discharge in Water Droplet Spray

    NASA Astrophysics Data System (ADS)

    Nose, Taisuke; Yokoyama, Yuzo; Nakamura, Akira; Minamitani, Yasushi

    Effect of O2 on the decolorization of indigo carmine and on the production of dissolved species such as NO2-, NO3-, O3 and H2O2 in the treatment water by pulsed discharge in water droplet spray was investigated by controlling the O2/N2 ratios as carrier gases in the reactor. The decolorization rate gradually increased with rise in O2 ratio, which reached a constant value in the range of 50% to 90% O2 ratio and decreased in pure O2. The maximum value was about 2 times as high as that of 20% O2 ratio. The decolorization efficiency was not affected by gas flow rate in the range of 4 L/min to 50 L/min. NO2- in the treatment water was only detected in pure N2, but NO3- was produced in O2/N2. NO2- added to the treatment water was not oxidized in pure N2, but was perfectly converted to NO3- in O2/N2. These results implied that hydroxyl radical produced in gas phase does not directly contribute to the oxidation of substances in water. O3 concentration gradually increased with rise in O2 ratio, whereas H2O2 concentration decreased. In the range of 50 to 80% O2 ratio, O3 and H2O2 concentrations were approximately constant value, similar to the trend of decolorization rate. Moreover rate constants on various gas mixing ratio of O2/N2 were determined from the kinetics study. These results suggested that hydroxyl radical produced in the treatment water by the chain reactions of O3 and hydroperoxy radical (HO2·) plays an important role of the decomposition of molecules in water.

  3. Characteristics of produced water discharged to the Gulf of Mexico hypoxiczone.

    SciTech Connect

    Veil, J. A.; Kimmell, T. A.; Rechner, A. C.

    2005-08-24

    Each summer, an area of low dissolved oxygen (the hypoxic zone) forms in the shallow nearshore Gulf of Mexico waters from the Mississippi River Delta westward to near the Texas/Louisiana border. Most scientists believe that the leading contributor to the hypoxic zone is input of nutrients (primarily nitrogen and phosphorus compounds) from the Mississippi and Atchafalaya Rivers. The nutrients stimulate growth of phytoplankton. As the phytoplankton subsequently die, they fall to the bottom waters where they are decomposed by microorganisms. The decomposition process consumes oxygen in the bottom waters to create hypoxic conditions. Sources other than the two rivers mentioned above may also contribute significant quantities of oxygen-demanding pollutants. One very visible potential source is the hundreds of offshore oil and gas platforms located within or near the hypoxic zone. Many of these platforms discharge varying volumes of produced water. However, only limited data characterizing oxygen demand and nutrient concentration and loading from offshore produced water discharges have been collected. No comprehensive and coordinated oxygen demand data exist for produced water discharges in the Gulf of Mexico. This report describes the results of a program to sample 50 offshore oil and gas platforms located within the Gulf of Mexico hypoxic zone. The program was conducted in response to a requirement in the U.S. Environmental Protection Agency (EPA) general National Pollutant Discharge Elimination System (NPDES) permit for offshore oil and gas discharges. EPA requested information on the amount of oxygen-demanding substances contained in the produced water discharges. This information is needed as inputs to several water quality models that EPA intends to run to estimate the relative contributions of the produced water discharges to the occurrence of the hypoxic zone. Sixteen platforms were sampled 3 times each at approximately one-month intervals to give an estimate of

  4. In-stream Physical Heterogeneity, Rainfall Aided Flushing, and Discharge on Stream Water Quality.

    PubMed

    Gomes, Pattiyage I A; Wai, Onyx W H

    2015-08-01

    Implications of instream physical heterogeneity, rainfall-aided flushing, and stream discharge on water quality control have been investigated in a headwater stream of a climatic region that has contrasting dry and wet seasons. Dry (low flow) season's physical heterogeneity showed a positive correlation with good water quality. However, in the wet season, physical heterogeneity showed minor or no significance on water quality variations. Furthermore, physical heterogeneity appeared to be more complementary with good water quality subsequent to rainfall events. In many cases stream discharge was a reason for poor water quality. For the dry season, graywater inputs to the stream could be held responsible. In the wet season, it was probably the result of catchment level disturbances (e.g., regulation of ephemeral freshwater paths). Overall, this study revealed the importance of catchment-based approaches on water quality improvement in tandem with in-stream approaches framed on a temporal scale. PMID:26237692

  5. Hyporheic discharge of river water into fall chinook salmon (Oncorhynchus tshawytscha) spawning areas in the Hanford Reach, Columbia River

    SciTech Connect

    Geist, David R. )

    1999-12-01

    Fall chinook salmon (Oncorhynchus tshawytscha) spawned predominantly in areas of the Hanford Reach of the Columbia River where hyporheic water discharged into the river channel. This upwelling water had a dissolved solids content (i.e., specific conductance) indicative of river water and was presumed to have entered highly permeable riverbed substrate at locations upstream of the spawning areas. Hyporheic discharge zones composed of undiluted ground water or areas with little or no upwelling were not used by spawning salmon. Rates of upwelling into spawning areas averaged 1,200 L?m-2?day-1 (95% C.I.= 784 to 1,665 L?m-2?day-1) as compared to approximately 500 L?m-2?day-1 (95% C.I.= 303 to 1,159 L?m-2?day-1) in non-spawning areas. Dissolved oxygen content of the hyporheic discharge near salmon spawning areas was about 9 mg?L-1 (+ 0.4 mg?L-1) whereas in non-spawning areas dissolved oxygen values were 7 mg?L-1 (+ 0.9 mg?L-1) or lower. In both cases dissolved oxygen of the river water was higher (11.3+ 0.3 mg?L-1). Physical and chemical gradients between the hyporheic zone and the river may provide cues for adult salmon to locate suitable spawning areas. This information will help fisheries managers to describe the suitability of salmon spawning habitat in large rivers.

  6. Ground-penetrating radar methods used in surface-water discharge measurements

    USGS Publications Warehouse

    Haeni, F.P.; Buursink, Marc L.; Costa, John E.; Melcher, Nick B.; Cheng, Ralph T.; Plant, William J.

    2000-01-01

    In 1999, an experiment was conducted to see if a combination of complementary radar methods could be used to calculate the discharge of a river without having any of the measuring equipment in the water. The cross-sectional area of the 183-meter wide Skagit River in Washington State was measured using a ground-penetrating radar (GPR) system with a single 100-MHz antenna. A van-mounted, side-looking pulsed-Doppler radar system was used to collect water-surface velocity data across the same section of the river. The combined radar data sets were used to calculate the river discharge and the results compared closely to the discharge measurement made by using the standard in-water measurement techniques.

  7. Differential Inactivation of Fungal Spores in Water and on Seeds by Ozone and Arc Discharge Plasma.

    PubMed

    Kang, Min Ho; Pengkit, Anchalee; Choi, Kihong; Jeon, Seong Sil; Choi, Hyo Won; Shin, Dong Bum; Choi, Eun Ha; Uhm, Han Sup; Park, Gyungsoon

    2015-01-01

    Seed sterilization is essential for preventing seed borne fungal diseases. Sterilization tools based on physical technologies have recently received much attention. However, available information is very limited in terms of efficiency, safety, and mode of action. In this study, we have examined antifungal activity of ozone and arc discharge plasma, potential tools for seed sterilization. In our results, ozone and arc discharge plasma have shown differential antifungal effects, depending on the environment associated with fungal spores (freely submerged in water or infected seeds). Ozone inactivates Fusarium fujikuroi (fungus causing rice bakanae disease) spores submerged in water more efficiently than arc discharge plasma. However, fungal spores associated with or infecting rice seeds are more effectively deactivated by arc discharge plasma. ROS generated in water by ozone may function as a powerful fungicidal factor. On the other hand, shockwave generated from arc discharge plasma may have greatly contributed to antifungal effects on fungus associated with rice seeds. In support of this notion, addition of ultrasonic wave in ozone generating water has greatly increased the efficiency of seed disinfection. PMID:26406468

  8. Differential Inactivation of Fungal Spores in Water and on Seeds by Ozone and Arc Discharge Plasma

    PubMed Central

    Kang, Min Ho; Pengkit, Anchalee; Choi, Kihong; Jeon, Seong Sil; Choi, Hyo Won; Shin, Dong Bum; Choi, Eun Ha; Uhm, Han Sup; Park, Gyungsoon

    2015-01-01

    Seed sterilization is essential for preventing seed borne fungal diseases. Sterilization tools based on physical technologies have recently received much attention. However, available information is very limited in terms of efficiency, safety, and mode of action. In this study, we have examined antifungal activity of ozone and arc discharge plasma, potential tools for seed sterilization. In our results, ozone and arc discharge plasma have shown differential antifungal effects, depending on the environment associated with fungal spores (freely submerged in water or infected seeds). Ozone inactivates Fusarium fujikuroi (fungus causing rice bakanae disease) spores submerged in water more efficiently than arc discharge plasma. However, fungal spores associated with or infecting rice seeds are more effectively deactivated by arc discharge plasma. ROS generated in water by ozone may function as a powerful fungicidal factor. On the other hand, shockwave generated from arc discharge plasma may have greatly contributed to antifungal effects on fungus associated with rice seeds. In support of this notion, addition of ultrasonic wave in ozone generating water has greatly increased the efficiency of seed disinfection. PMID:26406468

  9. Dielectric surface discharges: Effects of combined low-energy and high-energy incident electrons

    NASA Technical Reports Server (NTRS)

    Balmain, K. G.; Hirt, W.

    1981-01-01

    Dielectric surface discharges affected by the addition of high energy electrons at 5 pA/sq cm to a primary 20 keV, 10 nA/sq cm electron beam with the high energy broad spectrum particles coming from the beta decay of Strontium 90 are studied. Kapton exhibits significantly increased discharge strength, increased waiting time between discharges, and a decreased number of discharges per specimen before discharge cessation. Mylar exhibits similar but less pronounced effects, while Teflon is relatively unaffected. With Kapton and Mylar, the high energy electrons act in some way to delay the instant of discharge ignition so that more charge can be accumulated and hence released during discharge.

  10. Dielectric surface discharges - Effects of combined low-energy and high-energy incident electrons

    NASA Technical Reports Server (NTRS)

    Balmain, K. G.; Hirt, W.

    1983-01-01

    Dielectric surface discharges affected by the addition of high energy electrons at 5 pA/sq cm to a primary 20 keV, 10 nA/sq cm electron beam with the high energy broad spectrum particles coming from the beta decay of Strontium 90 are studied. Kapton exhibits significantly increased discharge strength, increased waiting time between discharges, and a decreased number of discharges per specimen before discharge cessation. Mylar exhibits similar but less pronounced effects, while Teflon is relatively unaffected. With Kapton and Mylar, the high energy electrons act in some way to delay the instant of discharge ignition so that more charge can be accumulated and hence released during discharge. Previously announced in STAR as N82-14222

  11. Continental freshwater discharge estimates from satellite observations and terrestrial water balance

    NASA Astrophysics Data System (ADS)

    Munier, S.; Cazenave, A. A.; Maisongrande, P.

    2011-12-01

    Freshwater discharge is a key component of the global water cycle. During the last few decades, remotely sensed hydro-climatic data has given the opportunity to overcome the numerous technical, political and economical challenges raised by ground-based observation networks. In the present study, we used satellite observations combined with atmospheric reanalysis in a coupled ocean-land-atmosphere water mass balance to estimate freshwater discharge over the last few years at basin, continental and global scales. Variations in terrestrial water storage (TWS) are provided by the Gravity Recovery and Climate Experiment (GRACE) mission, whereas precipitation minus evapotranspiration (P-E) is computed from atmospheric reanalyses (NCEP-NCAR and ECMWF datasets). In order to assess the accuracy of freshwater discharge estimates, uncertainties in each terms of the water balance are explored. GRACE-derived TWS is compared to outputs of Land Surface Models (GLDAS, WGHM and ISBA), keeping in mind that LSMs generally do not account for human-induced effects on the hydrological cycle. Independently, reanalysis-based P-E is compared to remotely sensed and/or in situ observations of precipitation (GPCC, GPCP, CMAP), evaporation over oceans (OAFlux, HOAPS) and modeled evapotranspiration over land (Penman-Monteith and Priestley-Taylor). Finally, freshwater discharge estimates are compared to in situ discharge observations from GRDC and to estimates from previous global studies. Discrepancies between the different datasets, in terms of annual mean as well as seasonal and inter-annual variability, allowed us to draw uncertainty maps, then highlighting regions where freshwater discharge estimates are the most uncertain. Such results may help to focus future developments on hydrological modeling for further improvement in freshwater discharge estimates.

  12. High methylmercury production under ferruginous conditions in sediments impacted by sewage treatment plant discharges.

    PubMed

    Bravo, Andrea G; Bouchet, Sylvain; Guédron, Stéphane; Amouroux, David; Dominik, Janusz; Zopfi, Jakob

    2015-09-01

    Sewage treatment plants (STPs) are important point sources of mercury (Hg) to the environment. STPs are also significant sources of iron when hydrated ferric oxide (HFO) is used as a dephosphatation agent during water purification. In this study, we combined geochemical and microbiological characterization with Hg speciation and sediment amendments to evaluate the impact of STP's effluents on monomethylmercury (MMHg) production. The highest in-situ Hg methylation was found close to the discharge pipe in subsurface sediments enriched with Hg, organic matter, and iron. There, ferruginous conditions were prevailing with high concentrations of dissolved Fe(2+) and virtually no free sulfide in the porewater. Sediment incubations demonstrated that the high MMHg production close to the discharge was controlled by low demethylation yields. Inhibition of dissimilatory sulfate reduction with molybdate led to increased iron reduction rates and Hg-methylation, suggesting that sulfate-reducing bacteria (SRB) may not have been the main Hg methylators under these conditions. However, Hg methylation in sediments amended with amorphous Fe(III)-oxides was only slightly higher than control conditions. Thus, in addition to iron-reducing bacteria, other non-SRB most likely contributed to Hg methylation. Overall, this study highlights that sediments impacted by STP discharges can become local hot-spots for Hg methylation due to the combined inputs of i) Hg, ii) organic matter, which fuels bacterial activities and iii) iron, which keeps porewater sulfide concentration low and hence Hg bioavailable. PMID:26005785

  13. 30 CFR 250.217 - What solid and liquid wastes and discharges information and cooling water intake information must...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... information and cooling water intake information must accompany the EP? 250.217 Section 250.217 Mineral... What solid and liquid wastes and discharges information and cooling water intake information must accompany the EP? The following solid and liquid wastes and discharges information and cooling water...

  14. 30 CFR 550.248 - What solid and liquid wastes and discharges information and cooling water intake information must...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... information and cooling water intake information must accompany the DPP or DOCD? 550.248 Section 550.248... liquid wastes and discharges information and cooling water intake information must accompany the DPP or DOCD? The following solid and liquid wastes and discharges information and cooling water...

  15. 30 CFR 250.248 - What solid and liquid wastes and discharges information and cooling water intake information must...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... information and cooling water intake information must accompany the DPP or DOCD? 250.248 Section 250.248... and discharges information and cooling water intake information must accompany the DPP or DOCD? The following solid and liquid wastes and discharges information and cooling water intake information...

  16. 30 CFR 550.217 - What solid and liquid wastes and discharges information and cooling water intake information must...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... information and cooling water intake information must accompany the EP? 550.217 Section 550.217 Mineral... What solid and liquid wastes and discharges information and cooling water intake information must accompany the EP? The following solid and liquid wastes and discharges information and cooling water...

  17. Method and apparatus for nondestructive testing. [using high frequency arc discharges

    NASA Technical Reports Server (NTRS)

    Hoop, J. M. (Inventor)

    1974-01-01

    High voltage is applied to an arc gap adjacent to a test specimen to develop a succession of high frequency arc discharges. Those high frequency arc discharges generate pulses of ultrasonic energy within the test specimen without requiring the arc discharges to contact that test specimen and without requiring a coupling medium. Those pulses can be used for detection of flaws and measurements of certain properties and stresses within the test specimen.

  18. Long-term effects of discharges of produced water the marine environment from petroleum-related activities at Sonda de Campeche, Gulf of México.

    PubMed

    Schifter, I; González-Macías, C; Salazar-Coria, L; Sánchez-Reyna, G; González-Lozano, C

    2015-11-01

    Produced water from offshore oil platforms is a major source of oil and related chemicals into the sea. The large volume and high salinity of produced water could pose severe environmental impacts upon inadequate disposal. This study is based on direct field sampling of effluents released into the ocean in the years 2003 and 2013 at the Sonda de Campeche located in the southern part of the Gulf of Mexico. Metals and hydrocarbons were characterized in water, sediments, and fish tissues at the discharge site and compared with those obtained at two reference sites. Chemicals that exceeded risk-based concentrations in the discharge included the metals As, Pb, Cd, and Cr, and a variety of compounds polycyclic aromatic hydrocarbon (PAHs), including naphthalene, fluorenes, and low molecular weight PAHs. The values of low to high molecular weight polycyclic aromatic hydrocarbon (PAHs), and carbon preference index indicate that hydrocarbons in sediments of the discharge zone are originated from the produced water and combustion sources. Fish tissues at the discharge zone and reference site are contaminated with PAHs, dominated by 2- and 3-rings; 4-ring accounted for less than 1% of total PAHs (TPAHs) in 2003, but increased to 7% in 2013. Results suggest that, from 2003 to 2013, discharges of produced water have had a non-negligible impact on ecosystems at a regional level, so the possibility of subtle, cumulative effects from operational discharges should not be ignored. PMID:26519077

  19. High-altitude electrical discharges associated with thunderstorms and lightning

    NASA Astrophysics Data System (ADS)

    Liu, Ningyu; McHarg, Matthew G.; Stenbaek-Nielsen, Hans C.

    2015-12-01

    The purpose of this paper is to introduce electrical discharge phenomena known as transient luminous events above thunderstorms to the lightning protection community. Transient luminous events include the upward electrical discharges from thunderstorms known as starters, jets, and gigantic jets, and electrical discharges initiated in the lower ionosphere such as sprites, halos, and elves. We give an overview of these phenomena with a focus on starters, jets, gigantic jets, and sprites, because similar to ordinary lightning, streamers and leaders are basic components of these four types of transient luminous events. We present a few recent observations to illustrate their main properties and briefly review the theories. The research in transient luminous events has not only advanced our understanding of the effects of thunderstorms and lightning in the middle and upper atmosphere, but also improved our knowledge of basic electrical discharge processes critical for sparks and lightning.

  20. DEVICE AND METHOD FOR PRODUCING A HIGH INTENSITY ARC DISCHARGE

    DOEpatents

    Luce, J.S.

    1960-01-01

    A device is described for producing an energetic d-c carbon arc discharge between widely spaced electrodes with arc currents in excess of 100 amperes in a magnetic field of about 3000 gauss and witnin an evacuated enclo sure at a pressure of about 10/sup -5/ mm Hg. No defining electrodes are used in the device, thus essentially eliminating the problems of shorting which heretofore limited the amount of current that could be produced in an arc discharge. The energetic carbon arc discharge is sustained by the potential across the electrodes and by carbon ions and electrons released from the electrodes during arc operation. A large part of the potential drop of the arc occurs along the arc and many energetic electrons reach the anode because the arc pressure is relatively low, and few collisions occur. The carbon discharge is also an efficient ion pump.

  1. Application of pulsed spark discharge for calcium carbonate precipitation in hard water.

    PubMed

    Yang, Yong; Kim, Hyoungsup; Starikovskiy, Andrey; Fridman, Alexander; Cho, Young I

    2010-06-01

    The effect of underwater pulsed spark discharge on the precipitation of dissolved calcium ions was investigated in the present study. Water samples with different calcium hardness were prepared by continuous evaporation of tap water using a laboratory cooling tower. It was shown that the concentration of calcium ions dropped by 20-26% after 10-min plasma treatment, comparing with no drop for untreated cases. A laser particle counting method demonstrated that the total number of solid particles suspended in water increased by over 100% after the plasma treatment. The morphology and the crystal form of the particles were identified by both scanning electron microscopy and X-ray diffraction. Calcite with rhombohedron morphology was observed for plasma treated cases, comparing with the round structure observed for no-treatment cases. It was hypothesized that the main mechanisms for the plasma-assisted calcium carbonate precipitation might include electrolysis, local heating in the vicinity of plasma channel and a high electric field at the tip of plasma streamers, inducing structural changes in the electric double layer of hydrated ions. PMID:20494397

  2. Plasma potential mapping of high power impulse magnetron sputtering discharges

    SciTech Connect

    Rauch, Albert; Mendelsberg, Rueben J.; Sanders, Jason M.; Anders, Andre

    2012-04-15

    Pulsed emissive probe techniques have been used to determine the plasma potential distribution of high power impulse magnetron sputtering (HiPIMS) discharges. An unbalanced magnetron with a niobium target in argon was investigated for a pulse length of 100 {mu}s at a pulse repetition rate of 100 Hz, giving a peak current of 170 A. The probe data were recorded with a time resolution of 20 ns and a spatial resolution of 1 mm. It is shown that the local plasma potential varies greatly in space and time. The lowest potential was found over the target's racetrack, gradually reaching anode potential (ground) several centimeters away from the target. The magnetic presheath exhibits a funnel-shaped plasma potential resulting in an electric field which accelerates ions toward the racetrack. In certain regions and times, the potential exhibits weak local maxima which allow for ion acceleration to the substrate. Knowledge of the local E and static B fields lets us derive the electrons'ExB drift velocity, which is about 10{sup 5} m/s and shows structures in space and time.

  3. Plasma potential mapping of high power impulse magnetron sputtering discharges

    SciTech Connect

    Rauch, Albert; Mendelsberg, Rueben J.; Sanders, Jason M.; Anders, Andre

    2011-12-20

    Pulsed emissive probe techniques have been used to determine the plasma potential distribution of high power impulse magnetron sputtering (HiPIMS) discharges. An unbalanced magnetron with a niobium target in argon was investigated for pulse length of 100 μs at a pulse repetition rate of 100 Hz, giving a peak current of 170 A. The probe data were taken with a time resolution of 20 ns and a spatial resolution of 1 mm. It is shown that the local plasma potential varies greatly in space and time. The lowest potential was found over the target’s racetrack, gradually reaching anode potential (ground) several centimeters away from the target. The magnetic pre-sheath exhibits a funnel-shaped plasma potential resulting in an electric field which accelerates ions toward the racetrack. In certain regions and times, the potential exhibits weak local maxima which allow for ion acceleration to the substrate. Knowledge of the local E and static B fields lets us derive the electrons’ E×B drift velocity, which is about 105 m/s and shows structures in space and time.

  4. Spectroscopic imaging of metal halide high-intensity discharge lamps

    NASA Astrophysics Data System (ADS)

    Bonvallet, Geoffrey A.

    The body of this work consists of three main research projects. An optical- and near-ultraviolet-wavelength absorption study sought to determine absolute densities of ground and excited level Sc atoms, ground level Sc + ions, and ground level Na atoms in a commercial 250 W metal halide high intensity discharge lamp during operation. These measurements also allowed the determination of the arc temperature and absolute electron density as functions of radius. Through infrared emission spectroscopy, relative densities of sodium and scandium were determined as functions of radius. Using the absolute densities gained from the optical experiment, these relative densities were calibrated. In addition, direct observation of the infrared emission allowed us to characterize the infrared power losses of the lamp. When considered as a fraction of the overall power consumption, the near-infrared spectral power losses were not substantial enough to warrant thorough investigation of their reduction in these lamps. The third project was an attempt to develop a portable x-ray diagnostic experiment. Two-dimensional spatial maps of the lamps were analyzed to determine absolute elemental mercury densities and the arc temperature as a function of radius. Two methods were used to improve the calibration of the density measurements and to correct for the spread in x-ray energy: known solutions of mercury in nitric acid, and an arc lamp which was uniformly heated to evaporate the mercury content. Although many complexities arose in this experiment, its goal was successfully completed.

  5. Pulse modulated high-pressure caesium discharge lamp

    NASA Astrophysics Data System (ADS)

    Gu, H.; Muzeroll, M. E.; Chamberlain, J. C.; Maya, J.

    2001-02-01

    The high-pressure caesium discharge has a favourable spectral distribution consisting of a smooth recombination continuum in the visible range. When operated on a continuous power source, the spectrum in the visible region is close to blackbody radiation; however, the lamp efficacy is restrained by the self-reversed resonance lines occurring at 825 nm and 894 nm. Pulse modulation significantly increases the core plasma temperature, suppresses the near-infrared segment of the spectrum, strongly enhances the continuous radiation in the visible region, and successfully avoids overloading (<40 W cm-2) the arc tubes. The spectrum in the visible appears to have the same shape as blackbody radiation when the lamp is operated on a multiple pulse modulated power source. The arc tube geometry, caesium/mercury compositions, and power supply waveforms were optimized for photometric performance through a series of comparison tests. The lamp efficacy increased with narrower diameter arc tubes, higher lamp currents, as well as higher current crest factors (ratio of current pulse peak to RMS current). The highest efficacy achieved for the lamp operated on the pulse modulated power supply was 46 lpw. The lamp exhibits excellent dimming characteristics and has a colour rendering index (CRI) very close to a thermal source such as a tungsten halogen lamp. This study provides a framework for the design of a new lamp/ballast system which features excellent dimming characteristics, a near-perfect CRI, an efficacy above 40 lpw, and long life. The application for this light source could be a replacement for a high-end tungsten halogen or a white high-pressure sodium lamp.

  6. Effect of Electrolytes on the Decomposition of Dye by Pulsed Discharge in Air Spraying Water Droplets

    NASA Astrophysics Data System (ADS)

    Nose, Taisuke; Yokoyama, Yuzo; Minamitani, Yasushi

    Effect of electrolytes on the decolorization of indigo carmine and on the production of H2O2 by pulsed discharge in air spraying water droplets was performed in sodium chloride and magnesium sulfate solutions. Peak voltage of the discharge decreased with increasing solution conductivity, but peak current and discharge energy increased. Decolorization rate and decolorization efficiency of indigo carmine and the yield of H2O2 decreased with increasing chloride and sulfate ion concentrations. It was found that the decolorization of indigo carmine and the production of H2O2 are affected by the ion concentration even in the case of discharge in air spraying water droplets. However it was less effective than that of discharge in water. Chloride ion was more effective than sulfate ion regarding the decrease of decolorization rate and the production of H2O2. Decolorization rate of indigo carmine was strongly related to the production of H2O2. These results also indicated that decolorization of indigo carmine depends on the production of hydroxyl radical.

  7. High-intensity vacuum-ultraviolet generator utilizing a surface-discharge diode

    NASA Astrophysics Data System (ADS)

    Sagae, Michiaki; Sato, Eiichi; Oizumi, Teiji; Hayasi, Yasuomi; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1995-05-01

    The fundamental studies on a high-intensity flash vacuum-ultraviolet (VUV) generator for producing water-window flash x rays are described. This generator consisted of the following essential components: a high- voltage power supply, a coaxial high-voltage pulser having a 0.2 (mu) F condenser, a Krytron pulser as a trigger device, a turbo molecular pump, and a VUV tube. The VUV tube employed a surface-discharge ferrite substrate having two copper electrodes and was evacuated by the pump with a pressure of 1.3 X 10-3 Pa. The condenser in the pulser was charged from 10 to 30 kV by the power supply, and the electric charges in the condenser were discharged to the radiation tube after closing a gap switch by the Krytron pulser. Then the flash VUV rays were generated. The maximum output voltage from the pulser was almost equivalent to the charged voltage, and both the tube voltage and current displayed damped oscillations. The maximum values of the tube voltage and current were approximately 23 kV and 13 kA, respectively. Since the effective accelerating voltage was substantially decreased by the substrate, soft x rays were easily generated. The pulse durations of the VUV rays including water window x rays were nearly equivalent to those of the damped oscillations of the voltage and current, and their values were less than 30 microsecond(s) .

  8. Critical discharge of initially subcooled water through slits. [PWR; BWR

    SciTech Connect

    Amos, C N; Schrock, V E

    1983-09-01

    This report describes an experimental investigation into the critical flow of initially subcooled water through rectangular slits. The study of such flows is relevant to the prediction of leak flow rates from cracks in piping, or pressure vessels, which contain sufficient enthalpy that vaporization will occur if they are allowed to expand to the ambient pressure. Two new analytical models, which allow for the generation of a metastable liquid phase, are developed. Experimental results are compared with the predictions of both these new models and with a Fanno Homogeneous Equilibrium Model.

  9. Discharge, water temperature, and selected meteorological data for Vancouver Lake, Vancouver, Washington, water years 2011-13

    USGS Publications Warehouse

    Foreman, James R.; Marshall, Cameron A.; Sheibley, Rich W.

    2014-01-01

    The U.S. Geological Survey partnered with the Vancouver Lake Watershed Partnership in a 2-year intensive study to quantify the movement of water and nutrients through Vancouver Lake in Vancouver, Washington. This report is intended to assist the Vancouver Lake Watershed Partnership in evaluating potential courses of action to mitigate seasonally driven blooms of harmful cyanobacteria and to improve overall water quality of the lake. This report contains stream discharge, lake water temperature, and selected meteorological data for water years 2011, 2012, and 2013 that were used to develop the water and nutrient budgets for the lake.

  10. Charging and discharging of single colloidal particles at oil/water interfaces

    NASA Astrophysics Data System (ADS)

    Gao, Peng; Xing, Xiaochen; Li, Ye; Ngai, To; Jin, Fan

    2014-05-01

    The physical behavior of solid colloids trapped at a fluid-fluid interface remains in itself an open fundamental issue. Here, we show that the gradients of surface tension can induce particles to jet towards the oil/water interface with velocities as high as ~ 60 mm/s when particle suspensions come in contact with the interface. We hypothesize that rubbing between the particles and oil lead to the spontaneous accumulation of negative charges on the hemisphere of those interfacial particles that contact the oil phase by means of triboelectrification. The charging process is highly dependent on the sliding distances, and gives rise to long-ranged repulsions that protect interfacial particles from coagulating at the interface by the presence of electrolyte. These triboelectric charges, however, are compensated within several hours, which affect the stability of interfacial particles. Importantly, by charging different kinds of colloidal particles using various spreading solvents and dispersion methods, we have demonstrated that charging and discharging of single colloidal particles at oil/water interfaces impacts a broad range of dynamical behavior.

  11. Charging and discharging of single colloidal particles at oil/water interfaces

    PubMed Central

    Gao, Peng; Xing, XiaoChen; Li, Ye; Ngai, To; Jin, Fan

    2014-01-01

    The physical behavior of solid colloids trapped at a fluid-fluid interface remains in itself an open fundamental issue. Here, we show that the gradients of surface tension can induce particles to jet towards the oil/water interface with velocities as high as ≈ 60 mm/s when particle suspensions come in contact with the interface. We hypothesize that rubbing between the particles and oil lead to the spontaneous accumulation of negative charges on the hemisphere of those interfacial particles that contact the oil phase by means of triboelectrification. The charging process is highly dependent on the sliding distances, and gives rise to long-ranged repulsions that protect interfacial particles from coagulating at the interface by the presence of electrolyte. These triboelectric charges, however, are compensated within several hours, which affect the stability of interfacial particles. Importantly, by charging different kinds of colloidal particles using various spreading solvents and dispersion methods, we have demonstrated that charging and discharging of single colloidal particles at oil/water interfaces impacts a broad range of dynamical behavior. PMID:24786477

  12. Effect of water on sulfur dioxide (SO2) and nitrogen oxides (NOx) removal from flue gas in a direct current corona discharge reactor

    NASA Astrophysics Data System (ADS)

    Yang, Jiaxiang; Chi, Xiaochun; Dong, Limin

    2007-05-01

    A direct current (dc) corona discharge reactor composed of needle-plate electrodes in a glass container filled with flue gas was designed. To clarify the influence of water on discharge characteristics, water was introduced in the plasma reactor as electrode where plate electrode is immersed, under the application of dc voltage. Experiment results show that (1) corona wind forming between high-voltage needle electrode and water by corona discharge enhances the cleaning efficiency of flue gas due to the existence of water and the cleaning efficiency will increase with the increase of applied dc voltage within definite range and (2) both removal efficiencies of NOx and SO2 increased in the presence of water, which reach up to 98% for SO2, and about 85% for NOx under suitable conditions. These results play an important role in flue gas cleanup research.

  13. Permitted water pollution discharges and population cancer and non-cancer mortality: toxicity weights and upstream discharge effects in US rural-urban areas

    PubMed Central

    2012-01-01

    Background The study conducts statistical and spatial analyses to investigate amounts and types of permitted surface water pollution discharges in relation to population mortality rates for cancer and non-cancer causes nationwide and by urban-rural setting. Data from the Environmental Protection Agency's (EPA) Discharge Monitoring Report (DMR) were used to measure the location, type, and quantity of a selected set of 38 discharge chemicals for 10,395 facilities across the contiguous US. Exposures were refined by weighting amounts of chemical discharges by their estimated toxicity to human health, and by estimating the discharges that occur not only in a local county, but area-weighted discharges occurring upstream in the same watershed. Centers for Disease Control and Prevention (CDC) mortality files were used to measure age-adjusted population mortality rates for cancer, kidney disease, and total non-cancer causes. Analysis included multiple linear regressions to adjust for population health risk covariates. Spatial analyses were conducted by applying geographically weighted regression to examine the geographic relationships between releases and mortality. Results Greater non-carcinogenic chemical discharge quantities were associated with significantly higher non-cancer mortality rates, regardless of toxicity weighting or upstream discharge weighting. Cancer mortality was higher in association with carcinogenic discharges only after applying toxicity weights. Kidney disease mortality was related to higher non-carcinogenic discharges only when both applying toxicity weights and including upstream discharges. Effects for kidney mortality and total non-cancer mortality were stronger in rural areas than urban areas. Spatial results show correlations between non-carcinogenic discharges and cancer mortality for much of the contiguous United States, suggesting that chemicals not currently recognized as carcinogens may contribute to cancer mortality risk. The

  14. Treatment of Dyeing Wastewater by Using Positive Pulsed Corona Discharge to Water Surface

    NASA Astrophysics Data System (ADS)

    Young, Sun Mok; Hyun, Tae Ahn; Joeng, Tai Kim

    2007-02-01

    This study investigated the treatment of textile-dyeing wastewater by using an electrical discharge technique (positive pulsed corona discharge). The high-voltage electrode was placed above the surface of the wastewater while the ground electrode was submerged in the wastewater. The electrical discharge starting at the tip of the high voltage electrode propagated toward the surface of the wastewater, producing various oxidative radicals and ozone. Oxygen was used as the working gas instead of air to prevent nitrogen oxides from forming. The simulated wastewater was made up with amaranth, which is a kind of azo dye. The results obtained showed that the chromaticity of the wastewater was almost completely removed within an hour. The ultraviolet/visible spectra of the wastewater treated by the electrical discharge revealed that the total hydrocarbon level also decreased significantly.

  15. Review of the methods to form hydrogen peroxide in electrical discharge plasma with liquid water

    NASA Astrophysics Data System (ADS)

    Locke, Bruce R.; Shih, Kai-Yuan

    2011-06-01

    This paper presents a review of the literature dealing with the formation of hydrogen peroxide from plasma processes. Energy yields for hydrogen peroxide generation by plasma from water span approximately three orders of magnitude from 4 × 10-2 to 80 g kWh-1. A wide range of plasma processes from rf to pulsed, ac, and dc discharges directly in the liquid phase have similar energy yields and may thus be limited by radical quenching processes at the plasma-liquid interface. Reactor modification using discharges in bubbles and discharges over the liquid phase can provide modest improvements in energy yield over direct discharge in the liquid, but the interpretation is complicated by additional chemical reactions of gas phase components such as ozone and nitrogen oxides. The highest efficiency plasma process utilizes liquid water droplets that may enhance efficiency by sequestering hydrogen peroxide in the liquid and by suppressing decomposition reactions by radicals from the gas and at the interface. Kinetic simulations of water vapor reported in the literature suggest that plasma generation of hydrogen peroxide should approach 45% of the thermodynamics limit, and this fact coupled with experimental studies demonstrating improvements with the presence of the condensed liquid phase suggest that further improvements in energy yield may be possible. Plasma generation of hydrogen peroxide directly from water compares favorably with a number of other methods including electron beam, ultrasound, electrochemical and photochemical methods, and other chemical processes.

  16. Environmental impacts of produced water and drilling waste discharges from the Norwegian offshore petroleum industry.

    PubMed

    Bakke, Torgeir; Klungsøyr, Jarle; Sanni, Steinar

    2013-12-01

    Operational discharges of produced water and drill cuttings from offshore oil and gas platforms are a continuous source of contaminants to continental shelf ecosystems. This paper reviews recent research on the biological effects of such discharges with focus on the Norwegian Continental Shelf. The greatest concern is linked to effects of produced water. Alkylphenols (AP) and polyaromatic hydrocarbons (PAH) from produced water accumulate in cod and blue mussel caged near outlets, but are rapidly metabolized in cod. APs, naphtenic acids, and PAHs may disturb reproductive functions, and affect several chemical, biochemical and genetic biomarkers. Toxic concentrations seem restricted to <2 km distance. At the peak of discharge of oil-contaminated cuttings fauna disturbance was found at more than 5 km from some platforms, but is now seldom detected beyond 500 m. Water-based cuttings may seriously affect biomarkers in filter feeding bivalves, and cause elevated sediment oxygen consumption and mortality in benthic fauna. Effects levels occur within 0.5-1 km distance. The stress is mainly physical. The risk of widespread, long term impact from the operational discharges on populations and the ecosystem is presently considered low, but this cannot be verified from the published literature. PMID:24119441

  17. Recombination time of an RF discharge plasma in the presence of water molecules

    SciTech Connect

    Protasevich, E.T.

    1986-05-01

    The authors show that the introduction of water vapor into an electrodeless rf discharge noticeably reduces the excitation temperature and substantially increases the recombination time of the plasma. An attempt is made to explain the physical processes associated with these phenomena.

  18. Time-delayed transition of normal-to-abnormal glow in pin-to-water discharge

    NASA Astrophysics Data System (ADS)

    Yoon, S.-Y.; Byeon, Y.-S.; Yoo, S.; Hong, E. J.; Kim, S. B.; Yoo, S. J.; Ryu, S.

    2016-08-01

    Time-delayed transition of normal-to-abnormal glow was investigated in discharge between spoke-like pins and ultrapure water by applying AC-driven power at a frequency of 14.3 kHz at atmospheric pressure. The normal-to-abnormal transition can be recognized from the slope changes of current density, gas temperature, electrode temperature, and OH density. The slope changes took place in tens of minutes rather than just after discharge, in other words, the transition was delayed. The time-delay of the transition was caused by the interaction between the plasma and water. The plasma affected water properties, and then the water affected plasma properties.

  19. A Simulation of Pre-Arcing Plasma Discharge Processes in Water Purification

    SciTech Connect

    Rodriguez-Mendez, B. G.; Piedad-Beneitez, A. de la; Lopez-Callejas, R.; Godoy-Cabrera, O. G.; Benitez-Read, J. S.; Pacheco-Sotelo, J. O.; Pena-Eguiluz, R.; Mercado-Cabrera, A.; Valencia-A, R.; Barocio, S. R.

    2006-12-04

    The simulation of a water purification system within a coaxial cylinder reactor operated by 1 kHz frequency plasma discharges in pre-arcing regimes is presented. In contrast with precedent works, this computational model considers three mechanisms of the system operation: (a) the relevant physical characteristics of water (b) the ionisation and expansion processes in the spark channel including the near-breakdown electric current generated by the rate of change of the effective capacitance and resistance in the discharge, and (c) the energy associated with this initial spark in the water. The outcome of the model seems to meet all main requirements to allow the design and construction of specific water purification technology devices.

  20. Plume survey OTEC-1 mixed-water discharge, April 11-12, 1981

    SciTech Connect

    Noda, E.K.; Bienfang, P.K.; Kimmerer, W.J.; Walsh, T.W.

    1981-05-01

    The environmental effects of mixed cold and warm water discharge from the OTEC-1 system is assessed by a plume survey. The specific objectives of the survey are: (1) to locate and map the physical extent of the thermal plume, both vertically and horizontally and determine the dilution of the discharging effluent with ambient waters as a function of location, and (2) to carry out a biological and water quality sampling program both within and out of the plume. The water quality sampling program involved measurement of dissolved oxygen, salinity and nutrients. The phytoplankton sampling program involves measurements of ATP, chlorophyll-a, and phaeopigments. The zooplankton program involves horizontal net tows both within and out of the plume. (LEW)

  1. Tracking stormwater discharge plumes and water quality of the Tijuana River with multispectral aerial imagery

    NASA Astrophysics Data System (ADS)

    Svejkovsky, Jan; Nezlin, Nikolay P.; Mustain, Neomi M.; Kum, Jamie B.

    2010-04-01

    Spatial-temporal characteristics and environmental factors regulating the behavior of stormwater runoff from the Tijuana River in southern California were analyzed utilizing very high resolution aerial imagery, and time-coincident environmental and bacterial sampling data. Thirty nine multispectral aerial images with 2.1-m spatial resolution were collected after major rainstorms during 2003-2008. Utilizing differences in color reflectance characteristics, the ocean surface was classified into non-plume waters and three components of the runoff plume reflecting differences in age and suspended sediment concentrations. Tijuana River discharge rate was the primary factor regulating the size of the freshest plume component and its shorelong extensions to the north and south. Wave direction was found to affect the shorelong distribution of the shoreline-connected fresh plume components much more strongly than wind direction. Wave-driven sediment resuspension also significantly contributed to the size of the oldest plume component. Surf zone bacterial samples collected near the time of each image acquisition were used to evaluate the contamination characteristics of each plume component. The bacterial contamination of the freshest plume waters was very high (100% of surf zone samples exceeded California standards), but the oldest plume areas were heterogeneous, including both polluted and clean waters. The aerial imagery archive allowed study of river runoff characteristics on a plume component level, not previously done with coarser satellite images. Our findings suggest that high resolution imaging can quickly identify the spatial extents of the most polluted runoff but cannot be relied upon to always identify the entire polluted area. Our results also indicate that wave-driven transport is important in distributing the most contaminated plume areas along the shoreline.

  2. Modeling discharge, temperature, and water quality in the Tualatin River, Oregon

    USGS Publications Warehouse

    Rounds, Stewart A.; Wood, Tamara M.; Lynch, Dennis D.

    1999-01-01

    The discharge, water temperature, and water quality of the Tualatin River in northwestern Oregon was simulated with CE-QUAL-W2, a two-dimensional, laterally averaged model developed by the U.S. Army Corps of Engineers. The model was calibrated for May through October periods of 1991, 1992, and 1993. Nine hypothetical scenarios were tested with the model to provide insight for river managers and regulators.

  3. 77 FR 17082 - Standards for Living Organisms in Ships' Ballast Water Discharged in U.S. Waters: Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ... notice regarding our public dockets in the January 17, 2008, issue of the Federal Register (73 FR 3316... preventing the introduction and spread of NIS via discharged ballast water (68 FR 55559). On July 28, 2004... of the United States, which was authorized under NISA (69 FR 44952). This program is currently...

  4. The influence of water in XLPE cable conductor on XLPE insulation breakdown voltage and partial discharge

    SciTech Connect

    Nikolajevic, S.V.; Stojanovic, B.B.

    1996-12-31

    This paper presents the results of a continuing investigation into degradation of the crosslinked polyethylene (XLPE) cable insulation. The paper deals with the changing of water absorption of various types of XLPE cable insulations: steam and nitrogen-dry cured crosslinked polyethylene (XL) and steam and nitrogen-dry cured water tree retardant crosslinked polyethylene (WTR-XL). The results of the study into effect of water absorption on breakdown stress (AC BDS) and partial discharge for different XLPE cable insulations are also given. During the aging tests, the cable conductor was poured with the tap water and the cable ends were properly closed.

  5. Field Evaluation Of Arsenic Transport Across The Ground-Water/Surface Water Interface: Ground-Water Discharge And Iron Oxide Precipitation

    EPA Science Inventory

    A field investigation was conducted to examine the distribution of arsenic in ground water, surface water, and sediments at a Superfund Site in the northeastern United States (see companion presentation by K. G. Scheckel et al). Ground-water discharge into the study area was cha...

  6. Hydrogeologic controls on ground-water and contaminant discharge to the Columbia River near the Hanford Townsite

    SciTech Connect

    Luttrell, S.P.; Newcomer, D.R.; Teel, S.S.; Vermeul, V.R.

    1992-11-01

    The purpose of this study is to quantify ground-water and contaminant discharge to the Columbia River in the Hanford Townsite vicinity. The primary objectives of the work are to: describe the hydrogeologic setting and controls on ground-water movement and contaminant discharge to the Columbia River; understand the river/aquifer relationship and its effects on contaminant discharge to the Columbia River; quantify the ground-water and contaminant mass discharge to the Columbia River; and provide data that may be useful for a three-dimensional model of ground-water flow and contaminant transport in the Hanford Townsite study area. The majority of ground-water contamination occurs within the unconfined aquifer; therefore, ground-water and contaminant discharge from the unconfined aquifer is the emphasis of this study. The period of study is primarily from June 1990 through March 1992.

  7. River Discharge and Bathymetry Estimation from Hydraulic Inversion of Surface Currents and Water Surface Elevation Observations

    NASA Astrophysics Data System (ADS)

    Simeonov, J.; Holland, K. T.

    2015-12-01

    We developed an inversion model for river bathymetry and discharge estimation based on measurements of surface currents, water surface elevation and shoreline coordinates. The model uses a simplification of the 2D depth-averaged steady shallow water equations based on a streamline following system of coordinates and assumes spatially uniform bed friction coefficient and eddy viscosity. The spatial resolution of the predicted bathymetry is related to the resolution of the surface currents measurements. The discharge is determined by minimizing the difference between the predicted and the measured streamwise variation of the total head. The inversion model was tested using in situ and remote sensing measurements of the Kootenai River east of Bonners Ferry, ID. The measurements were obtained in August 2010 when the discharge was about 223 m3/s and the maximum river depth was about 6.5 m. Surface currents covering a 10 km reach with 8 m spatial resolution were estimated from airborne infrared video and were converted to depth-averaged currents using acoustic Doppler current profiler (ADCP) measurements along eight cross-stream transects. The streamwise profile of the water surface elevation was measured using real-time kinematic GPS from a drifting platform. The value of the friction coefficient was obtained from forward calibration simulations that minimized the difference between the predicted and measured velocity and water level along the river thalweg. The predicted along/cross-channel water depth variation was compared to the depth measured with a multibeam echo sounder. The rms error between the measured and predicted depth along the thalweg was found to be about 60cm and the estimated discharge was 5% smaller than the discharge measured by the ADCP.

  8. Temporal modelling of ballast water discharge and ship-mediated invasion risk to Australia

    PubMed Central

    Cope, Robert C.; Prowse, Thomas A. A.; Ross, Joshua V.; Wittmann, Talia A.; Cassey, Phillip

    2015-01-01

    Biological invasions have the potential to cause extensive ecological and economic damage. Maritime trade facilitates biological invasions by transferring species in ballast water, and on ships' hulls. With volumes of maritime trade increasing globally, efforts to prevent these biological invasions are of significant importance. Both the International Maritime Organization and the Australian government have developed policy seeking to reduce the risk of these invasions. In this study, we constructed models for the transfer of ballast water into Australian waters, based on historic ballast survey data. We used these models to hindcast ballast water discharge over all vessels that arrived in Australian waters between 1999 and 2012. We used models for propagule survival to compare the risk of ballast-mediated propagule transport between ecoregions. We found that total annual ballast discharge volume into Australia more than doubled over the study period, with the vast majority of ballast water discharge and propagule pressure associated with bulk carrier traffic. As such, the ecoregions suffering the greatest risk are those associated with the export of mining commodities. As global marine trade continues to increase, effective monitoring and biosecurity policy will remain necessary to combat the risk of future marine invasion events. PMID:26064643

  9. Investigation of Optimum Applied Voltage for Water Treatment by Pulsed Streamer Discharge in Air Spraying Water Droplets

    NASA Astrophysics Data System (ADS)

    Sugai, Taichi; Suzuki, Tomoya; Minamitani, Yasushi; Nose, Taisuke

    In this study, we investigated a water treatment method spraying the droplets of wastewater into pulse discharge space. The water treatment was carried out by applying voltage with different pulse widths to determine the optimum pulse width, and the optimum pulse voltage determined on the basis of the results of the study was analyzed. The rise time of the voltages with pulse widths of 40, 60, and 80 ns was about 12, 19, and 32 ns, respectively, and the discharge current in the case of the faster rise time was higher. The number of streamer discharges is believed to increase with a decrease in the rise time. The energy efficiency in the case of the pulse width of 40 ns is higher than that in the case of the other pulse widths. This is because almost all of active species are generated by early streamer discharge, and longer discharging time by longer pulse width makes more ineffectual energy by thermal loss. These results show that the pulsed voltage of faster rise time and shorter pulse width is optimum for the treatment.

  10. Past peak water in Peru's Cordillera Blanca: diagnosing the demise of glacier influence on stream discharge

    NASA Astrophysics Data System (ADS)

    Baraer, M.; Mark, B. G.; McKenzie, J. M.

    2011-12-01

    In conditions of continuous retreat, glaciers generate a temporary increase in stream runoff as they lose mass. Yet as the extant glacier volume diminishes, the annual runoff reaches a peak and is followed by a persistent decrease. In the present study we explore historical and modern discharge measurements measured between 1952 and 2010 at nine stations across the upper Rio Santa watershed, the basin that drains most of the western Cordillera Blanca, Peru, and situate the regional stream hydrology within this glacier influence change sequence. The relation between glacial retreat and stream discharge is investigated by the use of a simple water balance model that simulates glacier retreat influence on the annual and dry-season discharge, as well as on the annual discharge variability, permitting distinction between four phases of glacier retreat hydrological impact. The link between the modeled synthetic time series and the Cordillera Blanca discharge records is assessed using polynomial regressions and the Mann-Kendall non-parametric statistical test on daily discharge series for three hydrograph parameters: the yearly average, the dry season discharge and the variability coefficient. The glacial retreat for the same period is estimated using existing historical data of glacial coverage from an analysis of composite ASTER imagery that shows accelerating glacier recession in the upper Rio Santa watershed, with the overall glacierized area decreasing annually by 0.81 % between 1990 and 2009. The results provide statistically significant evidence that seven of the nine discharge time series have crossed a critical transition, and now exhibit a decreasing trend related to glacier retreat. La Balsa station measures discharge from the entire upper Rio Santa before entering a major hydro-electrical power plant, and it is undergoing a decline in dry season flow that probably began during the 1970s. Our results predict that if the glaciers completely melt, stream

  11. Macroscale water fluxes: 3. Effects of land processes on variability of monthly river discharge

    USGS Publications Warehouse

    Milly, P.C.D.; Wetherald, R.T.

    2002-01-01

    A salient characteristic of river discharge is its temporal variability. The time series of flow at a point on a river can be viewed as the superposition of a smooth seasonal cycle and an irregular, random variation. Viewing the random component in the spectral domain facilitates both its characterization and an interpretation of its major physical controls from a global perspective. The power spectral density functions of monthly flow anomalies of many large rivers worldwide are typified by a "red noise" process: the density is higher at low frequencies (e.g., <1 y-1) than at high frequencies, indicating disproportionate (relative to uncorrelated "white noise") contribution of low frequencies to variability of monthly flow. For many high-latitude and arid-region rivers, however, the power is relatively evenly distributed across the frequency spectrum. The power spectrum of monthly flow can be interpreted as the product of the power spectrum of monthly basin total precipitation (which is typically white or slightly red) and several filters that have physical significance. The filters are associated with (1) the conversion of total precipitation (sum of rainfall and snowfall) to effective rainfall (liquid flux to the ground surface from above), (2) the conversion of effective rainfall to soil water excess (runoff), and (3) the conversion of soil water excess to river discharge. Inferences about the roles of each filter can be made through an analysis of observations, complemented by information from a global model of the ocean-atmosphere-land system. The first filter causes a snowmelt-related amplification of high-frequency variability in those basins that receive substantial snowfall. The second filter causes a relatively constant reduction in variability across all frequencies and can be predicted well by means of a semiempirical water balance relation. The third filter, associated with groundwater and surface water storage in the river basin, causes a strong

  12. Estimated predevelopment discharge to streams from the High Plains Aquifer in northwestern Oklahoma, southwestern Kansas, and northwestern Texas

    USGS Publications Warehouse

    Luckey, R.R.; Becker, M.F.

    1998-01-01

    A study of the High Plains aquifer in Okla homa was initiated in 1996 to: (1) provide the information needed by the Oklahoma Water Resources Board to manage the quantity of water produced from the aquifer; and (2) provide base line water-chemistry data. The approach used to meet the first objective is to develop a digital ground-water flow model. The model will be cali brated, in part, by comparing simulated and esti mated predevelopment discharge from the aquifer to streams and cross-boundary flow. This report presents the estimated predevelopment discharge to streams from the High Plains aquifer. Streamflow data were the primary source of information used to estimate predevelopment dis charge from the High Plains aquifer. Data from 30 streamflow stations between the Arkansas and Canadian Rivers were considered in the analysis, and winter low-flow frequencies for 7-, 14-, and 30-day periods were determined for 25 stations. The 14-day low flow with a recurrence interval of 2 years was the primary value used to estimate pre development discharge from the aquifer. The streams that drain the eastern part of the High Plains aquifer in Kansas (generally east of 99.5 longitude) are estimated to have had large predevelopment discharge from the aquifer, and most of them received discharge from near their headwaters. For streams with more than one streamflow gage, the upper perennial reaches appeared to have gained more discharge from the aquifer than the lower reaches. The total predevel opment discharge from the aquifer in this area to several streams is estimated to have been about 312 cubic feet per second, not including discharge that probably went directly to the Arkansas River. The Cimarron River and its tributaries are estimated to have gained about 78 cubic feet per second, but nearly one-half that amount was lost in the lower reaches of the river. The cause of the loss in the lower reaches is unknown. The Beaver River and its tributaries are estimated to have

  13. The source, discharge, and chemical characteristics of water from Agua Caliente Spring, Palm Springs, California

    USGS Publications Warehouse

    : Martin, Peter, (Edited By); Contributors: Brandt, Justin; Catchings, Rufus D.; Christensen, Allen H.; Flint, Alan L.; Gandhok, Gini; Goldman, Mark R.; Halford, Keith J.; Langenheim, V.E.; Martin, Peter; Rymer, Michael J.; Schroeder, Roy A.; Smith, Gregory A.; Sneed, Michelle

    2011-01-01

    Numerical models of fluid and temperature flow were developed for the Agua Caliente Spring to (1) test the validity of the conceptual model that the Agua Caliente Spring enters the valley-fill deposits from fractures in the underlying basement complex and rises through more than 800 feet of valley-fill deposits by way of a washed-sand conduit and surrounding low-permeability deposits (spring chimney) of its own making, (2) evaluate whether water-level declines in the regional aquifer will influence the temperature of discharging water, and (3) determine the source of thermal water in the perched aquifer. A radial-flow model was used to test the conceptual model and the effect of water-level declines. The observed spring discharge and temperature could be simulated if the vertical hydraulic conductivity of the spring orifice was about 200 feet per day and the horizontal hydraulic conductivity of the orifice (spring chimney) was about 0.00002 feet per day. The simulated vertical hydraulic conductivity is within the range of values reported for sand; however, the low value simulated for the horizontal hydraulic conductivity suggests that the spring chimney is cemented with increasing depth. Chemical data collected for this study indicate that the water at Agua Caliente Spring is at saturation with respect to both calcite and chalcedony, which provides a possible mechanism for cementation of the spring chimney. A simulated decline of about 100 feet in the regional aquifer had no effect on the simulated discharge of Agua Caliente Spring and resulted in a slight increase in the temperature of the spring discharge. Results from the radial-flow- and three-dimensional models of the Agua Caliente Spring area demonstrate that the distribution and temperature of thermal water in the perched water table can be explained by flow from a secondary shallow-subsurface spring orifice of the Agua Caliente Spring not contained by the steel collector tank, not by leakage from the

  14. High-speed micro-electro-discharge machining.

    SciTech Connect

    Chandrasekar, Srinivasan Dr. (.School of Industrial Engineering, West Lafayette, IN); Moylan, Shawn P. (School of Industrial Engineering, West Lafayette, IN); Benavides, Gilbert Lawrence

    2005-09-01

    When two electrodes are in close proximity in a dielectric liquid, application of a voltage pulse can produce a spark discharge between them, resulting in a small amount of material removal from both electrodes. Pulsed application of the voltage at discharge energies in the range of micro-Joules results in the continuous material removal process known as micro-electro-discharge machining (micro-EDM). Spark erosion by micro-EDM provides significant opportunities for producing small features and micro-components such as nozzle holes, slots, shafts and gears in virtually any conductive material. If the speed and precision of micro-EDM processes can be significantly enhanced, then they have the potential to be used for a wide variety of micro-machining applications including fabrication of microelectromechanical system (MEMS) components. Toward this end, a better understanding of the impacts the various machining parameters have on material removal has been established through a single discharge study of micro-EDM and a parametric study of small hole making by micro-EDM. The main avenues for improving the speed and efficiency of the micro-EDM process are in the areas of more controlled pulse generation in the power supply and more controlled positioning of the tool electrode during the machining process. Further investigation of the micro-EDM process in three dimensions leads to important design rules, specifically the smallest feature size attainable by the process.

  15. Linking glacially modified waters to catchment-scale subglacial discharge using autonomous underwater vehicle observations

    NASA Astrophysics Data System (ADS)

    Stevens, Laura A.; Straneo, Fiamma; Das, Sarah B.; Plueddemann, Albert J.; Kukulya, Amy L.; Morlighem, Mathieu

    2016-02-01

    Measurements of near-ice (< 200 m) hydrography and near-terminus subglacial hydrology are lacking, due in large part to the difficulty in working at the margin of calving glaciers. Here we pair detailed hydrographic and bathymetric measurements collected with an autonomous underwater vehicle as close as 150 m from the ice-ocean interface of the Saqqarliup sermia-Sarqardleq Fjord system, West Greenland, with modeled and observed subglacial discharge locations and magnitudes. We find evidence of two main types of subsurface glacially modified water (GMW) with distinct properties and locations. The two GMW locations also align with modeled runoff discharged at separate locations along the grounded margin corresponding with two prominent subcatchments beneath Saqqarliup sermia. Thus, near-ice observations and subglacial discharge routing indicate that runoff from this glacier occurs primarily at two discrete locations and gives rise to two distinct glacially modified waters. Furthermore, we show that the location with the largest subglacial discharge is associated with the lighter, fresher glacially modified water mass. This is qualitatively consistent with results from an idealized plume model.

  16. State waste discharge permit application 400 Area secondary cooling water. Revision 2

    SciTech Connect

    1996-01-01

    This document constitutes the Washington Administrative Code 173-216 State Waste Discharge Permit Application that serves as interim compliance as required by Consent Order DE 91NM-177, for the 400 Area Secondary Cooling Water stream. As part of the Hanford Federal Facility Agreement and Consent Order negotiations, the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site that affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173-216 of the Washington Administrative Code, the State Waste Discharge Permitting Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order DE 91NM-177. The Consent Order DE 91NM-177 requires a series of permitting activities for liquid effluent discharges. Based upon compositional and flow rate characteristics, liquid effluent streams on the Hanford Site have been categorized into Phase 1, Phase 2, and Miscellaneous streams. This document only addresses the 400 Area Secondary Cooling Water stream, which has been identified as a Phase 2 stream. The 400 Area Secondary Cooling Water stream includes contribution streams from the Fuels and Materials Examination Facility, the Maintenance and Storage Facility, the 481-A pump house, and the Fast Flux Test Facility.

  17. Risk assessment for produced water discharges to Louisiana open bays. Final report

    SciTech Connect

    Meinhold, A.F.; DePhillips, M.P.; Holtzman, S.

    1996-03-22

    The US Department of Energy (USDOE) has a program of research in the environmental aspects of oil and gas extraction. This sampling project will characterize the environmental impacts associated with the discharge of naturally occurring radioactive materials (NORM), metals and organics in produced water. This report is part of a series of studies of the health and ecological risks from discharges of produced water to the Gulf of Mexico, supported by the USDOE. These assessments are being coordinated with the field study, using the collected data to perform human health and ecological risk assessments. These assessments will provide input to regulators in the development of guidelines and permits, and to industry in the development and use of appropriate discharge practices. The initial human health and ecological risk assessments consist of conservative screening analyses meant to identify potentially important contaminants, and to eliminate others from further consideration. More quantitative assessments were done for contaminants identified, in the screening analysis, as being of potential concern. Section 2 gives an overview of human health and ecological risk assessment to help put the analyses presented here in perspective. Section 3 provides the hazard assessment portion of the risk assessment, and identifies the important receptors and pathways of concern. Section 3 also outlines the approach taken to the risk assessments presented in the rest of the report. The remaining sections (4 through 9) present the human health and ecological risk assessments for discharges of produced water to open bays in Louisiana.

  18. Synchronised electrical monitoring and high speed video of bubble growth associated with individual discharges during plasma electrolytic oxidation

    NASA Astrophysics Data System (ADS)

    Troughton, S. C.; Nominé, A.; Nominé, A. V.; Henrion, G.; Clyne, T. W.

    2015-12-01

    Synchronised electrical current and high speed video information are presented from individual discharges on Al substrates during PEO processing. Exposure time was 8 μs and linear spatial resolution 9 μm. Image sequences were captured for periods of 2 s, during which the sample surface was illuminated with short duration flashes (revealing bubbles formed where the discharge reached the surface of the coating). Correlations were thus established between discharge current, light emission from the discharge channel and (externally-illuminated) dimensions of the bubble as it expanded and contracted. Bubbles reached radii of 500 μm, within periods of 100 μs, with peak growth velocity about 10 m/s. It is deduced that bubble growth occurs as a consequence of the progressive volatilisation of water (electrolyte), without substantial increases in either pressure or temperature within the bubble. Current continues to flow through the discharge as the bubble expands, and this growth (and the related increase in electrical resistance) is thought to be responsible for the current being cut off (soon after the point of maximum radius). A semi-quantitative audit is presented of the transformations between different forms of energy that take place during the lifetime of a discharge.

  19. Multi-scale analysis of the fluxes between terrestrial water storage, groundwater, and stream discharge in the Columbia River Basin

    EPA Science Inventory

    The temporal relationships between the measurements of terrestrial water storage (TWS), groundwater, and stream discharge were analyzed at three different scales in the Columbia River Basin (CRB) for water years 2004 - 2012. Our nested watershed approach examined the Snake River ...

  20. High Input Voltage Discharge Supply for High Power Hall Thrusters Using Silicon Carbide Devices

    NASA Technical Reports Server (NTRS)

    Pinero, Luis R.; Scheidegger, Robert J.; Aulsio, Michael V.; Birchenough, Arthur G.

    2014-01-01

    A power processing unit for a 15 kW Hall thruster is under development at NASA Glenn Research Center. The unit produces up to 400 VDC with two parallel 7.5 kW discharge modules that operate from a 300 VDC nominal input voltage. Silicon carbide MOSFETs and diodes were used in this design because they were the best choice to handle the high voltage stress while delivering high efficiency and low specific mass. Efficiencies in excess of 97 percent were demonstrated during integration testing with the NASA-300M 20 kW Hall thruster. Electromagnet, cathode keeper, and heater supplies were also developed and will be integrated with the discharge supply into a vacuum-rated brassboard power processing unit with full flight functionality. This design could be evolved into a flight unit for future missions that requires high power electric propulsion.

  1. High-intensity xenon plasma discharge lamp for bulk-sensitive high-resolution photoemission spectroscopy

    SciTech Connect

    Souma, S.; Sato, T.; Takahashi, T.; Baltzer, P.

    2007-12-15

    We have developed a highly brilliant xenon (Xe) discharge lamp operated by microwave-induced electron cyclotron resonance (ECR) for ultrahigh-resolution bulk-sensitive photoemission spectroscopy (PES). We observed at least eight strong radiation lines from neutral or singly ionized Xe atoms in the energy region of 8.4-10.7 eV. The photon flux of the strongest Xe I resonance line at 8.437 eV is comparable to that of the He I{alpha} line (21.218 eV) from the He-ECR discharge lamp. Stable operation for more than 300 h is achieved by efficient air-cooling of a ceramic tube in the resonance cavity. The high bulk sensitivity and high-energy resolution of PES using the Xe lines are demonstrated for some typical materials.

  2. Analytical approach for determining the mean water level profile in an estuary with substantial fresh water discharge

    NASA Astrophysics Data System (ADS)

    Cai, Huayang; Savenije, Hubert H. G.; Jiang, Chenjuan; Zhao, Lili; Yang, Qingshu

    2016-03-01

    The mean water level in estuaries rises in the landward direction due to a combination of the density gradient, the tidal asymmetry, and the backwater effect. This phenomenon is more prominent under an increase of the fresh water discharge, which strongly intensifies both the tidal asymmetry and the backwater effect. However, the interactions between tide and river flow and their individual contributions to the rise of the mean water level along the estuary are not yet completely understood. In this study, we adopt an analytical approach to describe the tidal wave propagation under the influence of substantial fresh water discharge, where the analytical solutions are obtained by solving a set of four implicit equations for the tidal damping, the velocity amplitude, the wave celerity, and the phase lag. The analytical model is used to quantify the contributions made by tide, river, and tide-river interaction to the water level slope along the estuary, which sheds new light on the generation of backwater due to tide-river interaction. Subsequently, the method is applied to the Yangtze estuary under a wide range of river discharge conditions where the influence of both tidal amplitude and fresh water discharge on the longitudinal variation of the mean tidal water level is explored. Analytical model results show that in the tide-dominated region the mean water level is mainly controlled by the tide-river interaction, while it is primarily determined by the river flow in the river-dominated region, which is in agreement with previous studies. Interestingly, we demonstrate that the effect of the tide alone is most important in the transitional zone, where the ratio of velocity amplitude to river flow velocity approaches unity. This has to do with the fact that the contribution of tidal flow, river flow, and tide-river interaction to the residual water level slope are all proportional to the square of the velocity scale. Finally, we show that, in combination with extreme

  3. Decline of Yangtze River water and sediment discharge: Impact from natural and anthropogenic changes

    PubMed Central

    Yang, S. L.; Xu, K. H.; Milliman, J. D.; Yang, H. F.; Wu, C. S.

    2015-01-01

    The increasing impact of both climatic change and human activities on global river systems necessitates an increasing need to identify and quantify the various drivers and their impacts on fluvial water and sediment discharge. Here we show that mean Yangtze River water discharge of the first decade after the closing of the Three Gorges Dam (TGD) (2003–2012) was 67 km3/yr (7%) lower than that of the previous 50 years (1950–2002), and 126 km3/yr less compared to the relatively wet period of pre-TGD decade (1993–2002). Most (60–70%) of the decline can be attributed to decreased precipitation, the remainder resulting from construction of reservoirs, improved water-soil conservation and increased water consumption. Mean sediment flux decreased by 71% between 1950–1968 and the post-TGD decade, about half of which occurred prior to the pre-TGD decade. Approximately 30% of the total decline and 65% of the decline since 2003 can be attributed to the TGD, 5% and 14% of these declines to precipitation change, and the remaining to other dams and soil conservation within the drainage basin. These findings highlight the degree to which changes in riverine water and sediment discharge can be related with multiple environmental and anthropogenic factors. PMID:26206169

  4. Decline of Yangtze River water and sediment discharge: Impact from natural and anthropogenic changes

    NASA Astrophysics Data System (ADS)

    Yang, S. L.; Xu, K. H.; Milliman, J. D.; Yang, H. F.; Wu, C. S.

    2015-07-01

    The increasing impact of both climatic change and human activities on global river systems necessitates an increasing need to identify and quantify the various drivers and their impacts on fluvial water and sediment discharge. Here we show that mean Yangtze River water discharge of the first decade after the closing of the Three Gorges Dam (TGD) (2003-2012) was 67 km3/yr (7%) lower than that of the previous 50 years (1950-2002), and 126 km3/yr less compared to the relatively wet period of pre-TGD decade (1993-2002). Most (60-70%) of the decline can be attributed to decreased precipitation, the remainder resulting from construction of reservoirs, improved water-soil conservation and increased water consumption. Mean sediment flux decreased by 71% between 1950-1968 and the post-TGD decade, about half of which occurred prior to the pre-TGD decade. Approximately 30% of the total decline and 65% of the decline since 2003 can be attributed to the TGD, 5% and 14% of these declines to precipitation change, and the remaining to other dams and soil conservation within the drainage basin. These findings highlight the degree to which changes in riverine water and sediment discharge can be related with multiple environmental and anthropogenic factors.

  5. The impact of commercially treated oil and gas produced water discharges on bromide concentrations and modeled brominated trihalomethane disinfection byproducts at two downstream municipal drinking water plants in the upper Allegheny River, Pennsylvania, USA.

    PubMed

    Landis, Matthew S; Kamal, Ali S; Kovalcik, Kasey D; Croghan, Carry; Norris, Gary A; Bergdale, Amy

    2016-01-15

    In 2010, a dramatic increase in the levels of total trihalomethane (THM) and the relative proportion of brominated species was observed in finished water at several Pennsylvania water utilities (PDW) using the Allegheny River as their raw water supply. An increase in bromide (Br(-)) concentrations in the Allegheny River was implicated to be the cause of the elevated water disinfection byproducts. This study focused on quantifying the contribution of Br(-) from a commercial wastewater treatment facility (CWTF) that solely treats wastes from oil and gas producers and discharges into the upper reaches of the Allegheny River, and impacts on two downstream PDWs. In 2012, automated daily integrated samples were collected on the Allegheny River at six sites during three seasonal two-week sampling campaigns to characterize Br(-) concentrations and river dispersion characteristics during periods of high and low river discharges. The CWTF discharges resulted in significant increases in Br(-) compared to upstream baseline values in PDW raw drinking water intakes during periods of low river discharge. During high river discharge, the assimilative dilution capacity of the river resulted in lower absolute halide concentrations, but significant elevations Br(-) concentrations were still observed at the nearest downstream PDW intake over baseline river levels. On days with active CWTF effluent discharge the magnitude of bromide impact increased by 39 ppb (53%) and 7 ppb (22%) for low and high river discharge campaigns, respectively. Despite a declining trend in Allegheny River Br(-) (2009-2014), significant impacts from CWTF and coal-fired power plant discharges to Br(-) concentrations during the low river discharge regime at downstream PDW intakes was observed, resulting in small modeled increases in total THM (3%), and estimated positive shifts (41-47%) to more toxic brominated THM analogs. The lack of available coincident measurements of THM, precursors, and physical parameters

  6. Sediment and water discharge rates of Turkish Black Sea rivers before and after hydropower dam construction

    SciTech Connect

    Hay, B.J. )

    1994-06-01

    Presently, the water discharge rate to the Black Sea by Turkish rivers is approximately 41 km[sup 3]/yr. The sediment discharge rate of Turkish rivers to the Black Sea is 28 x 10[sup 6] t/yr. Before construction of the hydroelectric dams, the sediment discharge rate was approximately 70 x 10[sup 6] t/yr. The sharp reduction in sediment load is largely a result of the dams near the mouths of the Yesil Irmak and Kizil Irmak rivers. Before the construction of dams, Turkish rivers contributed approximately one third of the total amount of sediment received by the Black Sea from all surrounding rivers. The life-span of the major reservoirs varies from approximately only one century (Yesil Irmak river reservoirs) to several thousand years (Sakarya river reservoirs). Life-span for the large Altinkaya Dam reservoir is estimated with approximately 500 yr.

  7. Evaluation of a cost effective technique for treating aquaculture water discharge using Lolium perenne Lam as a biofilter.

    PubMed

    Nduwimana, André; Yang, Xiang-Long; Wang, Li-Ren

    2007-01-01

    Wastewater stabilization ponds generate low cost by-products that are useful for agriculture. The utilization of these by-products for soil amendment and as a source of nutrients for plants requires a high level of sanitation and stabilization of the organic matter, to maintain acceptable levels of soil, water and air quality. In this study, two aquaculture wastewater treatment systems; recirculating system and a floating plant bed system were designed to improve the quality of irrigation water in local communities with low income. In both systems the grass species Lolium perenne Lam was used as a plant biofilter while vegetable specie Amaranthus viridis was used to evaluate the performance of the system and the suitability of the phyto-treated water for irrigation. It was found that the harmful material removal rate for recirculating system was 88.9% for TAN (total ammonia nitrogen), 90% for NO2(-)-N, 64.8% for NO3(-)-N while for floating plant bed system 82.7% for TAN, 82% for NO2(-)-N and 60.5% for NO3(-)-N. Comparative analysis of the efficiency of waste element removal between the two systems revealed that both systems performed well, however, plant growth was not robust for floating plant bed system while recirculating system is energy consuming. Although both systems did not attain sufficient levels of TN (total nitrogen) and TP (total phosphorus) load reduction, the treatment with L. perenne remarkably improved the irrigation water quality. A. viridis plants irrigated with the phyto-treated discharge water had lesser concentrations of heavy metals in their tissues compared to those irrigated with untreated discharge. The control plants irrigated with untreated discharge were also found to be highly lignified with few stems and small leaves. PMID:17966513

  8. Martian Post-Impact Hydrothermal Systems: Effects of Permeability and Freezing on Surface Discharge and Water:Rock Ratios

    NASA Astrophysics Data System (ADS)

    Barnhart, C. J.; Nimmo, F.; Travis, B. J.

    2008-12-01

    A km-scale bolide delivers enough energy to heat subsurface water, and drive hydrothermal circulation (Abramov and Kring, 2005). This post-impact hydrothermal (PIH) circulation can lead to surface discharge of water, and chemical alteration - both are potentially detectable. We present the effects that permeability and freezing have on discharge and water:rock (W/R) ratios. We simulate the evolution of PIH systems using MAGHNUM (detailed in Travis et al., 2003). MAGHNUM solves the time-dependent transport of water and heat through a porous medium, incorporating phase transitions between ice (applicable to Mars), vapor and water. PIH evolution depends on heat sources and permeability (k); these, in turn, control discharge and chemical alteration which depends on both the peak temperatures and the W/R ratio (Schwenzer and Kring, 2008). Recently, CRISM detected phyllosilicate-rich material within ~45 km craters (Mustard et al., 2008) and the HiRISE camera imaged gullies, some emanating from central peaks, within many high latitude craters. We model a 45 km crater created by a 3.9 km dia., 7 km/s impactor. Simulations run for 100,000 yrs in a 2D axisymmetric domain with a heat flux of 32.5 mW m-2. Thus far we have tested systems with a range of surface k's (10-4 to 1 darcys) that decay exponentially with depth and are exposed to two surface temperatures (5°C and -53°C). In general W/R ratios increase with increased k. Focusing in on the upper 200 m at the center of the crater, fluid temperatures remain > 100°C for 9000 yrs and flow yields W/R ratios of 10 when exposed to a surface temperature of 5°C. Dropping the surface temperature below freezing to a Mars-like - 53°C maintains upper 200 m temperatures > 100°C for only 600 yrs and W/R ratios are reduced to 1. Higher permeabilities yield higher W/R ratios but reduced time exposure to high temperatures. When surface temperatures are below freezing total system discharge is roughly independent of k for modest

  9. Discharge, suspended sediment, bedload, and water quality in Clear Creek, western Nevada, water years 2010-12

    USGS Publications Warehouse

    Huntington, Jena M.; Savard, Charles S.

    2015-01-01

    During this study, total annual sediment loads ranged from 355 tons per year in 2010 to 1,768 tons per year in 2011 and were significantly lower than the previous study (water years 2004–07). Bedload represented between 29 and 38 percent of total sediment load in water years 2010–12, and between 72 and 90 percent of the total sediment load in water years 2004–07, which indicates a decrease in bedload between study periods. Annual suspended-sediment loads in water years 2010–12 indicated no significant change from water years 2004–07. Mean daily discharge was significantly lower in water years 2010–12 than in waters years 2004–07 and may be the reason for the decrease in bedload that resulted in a lower total sediment load.

  10. Counting at low concentrations: the statistical challenges of verifying ballast water discharge standards

    USGS Publications Warehouse

    Frazier, Melanie; Miller, A. Whitman; Lee, Henry, II; Reusser, Deborah A.

    2013-01-01

    Discharge from the ballast tanks of ships is one of the primary vectors of nonindigenous species in marine environments. To mitigate this environmental and economic threat, international, national, and state entities are establishing regulations to limit the concentration of living organisms that may be discharged from the ballast tanks of ships. The proposed discharge standards have ranged from zero detectable organisms to 3. If standard sampling methods are used, verifying whether ballast discharge complies with these stringent standards will be challenging due to the inherent stochasticity of sampling. Furthermore, at low concentrations, very large volumes of water must be sampled to find enough organisms to accurately estimate concentration. Despite these challenges, adequate sampling protocols comprise a critical aspect of establishing standards because they help define the actual risk level associated with a standard. A standard that appears very stringent may be effectively lax if it is paired with an inadequate sampling protocol. We describe some of the statistical issues associated with sampling at low concentrations to help regulators understand the uncertainties of sampling as well as to inform the development of sampling protocols that ensure discharge standards are adequately implemented.

  11. Initiation of a discharge channel in water by means of electrical explosion of aluminum foil

    NASA Astrophysics Data System (ADS)

    Sil'nikov, M. V.; Krivosheev, S. I.; Kulakov, K. S.; Kulakov, S. L.

    2013-12-01

    This paper reports the results of an experimental investigation into initiation of the electric discharge in service water by means of explosion of aluminum foil having various mass and dimensions. The electric discharge was formed in a chamber with a movable wall (the piston). As an electric energy storage, the capacitor bank having the capacity C = 200-600 μF with charging voltage U 0 = 2-5 kV (stored energy Q 0 = 0.4-7.5 kJ) and the rate of rise of the discharging current dI/ dt = (3-4) × 109 A/s. The results of experiments showed that destruction (loss of conductivity) of foil occurs at the value of the integral of the current density h j = (0.3-0.65) × 109 (A2/cm4)/s. The stage of the repeated breakdown in the electric discharge occurs when the value of the intensity of the electric field along the discharge channel is of E rb ≥ 50 V/mm. Geometric dimensions and mass of the initiating conductor that provide the maximum efficiency of conversion of the value of Q 0 into kinetic energy of the piston have been determined.

  12. Micro electrical discharge milling of WC-Co using a deionized water spray and a bipolar pulse

    NASA Astrophysics Data System (ADS)

    Song, Ki Young; Chung, Do Kwan; Park, Min Soo; Chu, Chong Nam

    2010-04-01

    Micro electrical discharge milling (ED-milling) is an effective machining process for manufacturing micro structures on hard metals. This method of machining generally uses kerosene or deionized water as the working fluid, both of which are associated with some problems. Kerosene results in considerable electrode wear and deionized water causes electrolytic corrosion in workpieces. In particular, when cemented tungsten carbide (WC-Co), which has superior strength, hardness and wear resistance, is machined by electrical discharge machining (EDM), the problem of electrolytic corrosion arises as a matter of course since the material is very susceptible to electrolyzation. In this study, spray ED-milling with a bipolar pulsed power source and deionized water was conducted to solve the above problems. This method uses a water spray, which is a mixture of compressed air and deionized water. The spray is injected into the machining gap between the electrode and the workpiece. WC-Co was used for the workpiece and micro grooves were machined on the workpiece. As a result, using the spray ED-milling method, high-quality micro grooves were manufactured on the WC-Co workpiece with no electrolytic corrosion and almost-zero electrode wear.

  13. Atmospheric Water Vapor Transport in NCEP-NCAR Reanalyses: Comparison with River Discharge in the Central United States.

    NASA Astrophysics Data System (ADS)

    Gutowski, William J., Jr.; Chen, Yibin; Ötles, Zekai

    1997-09-01

    The authors extract the water transport produced by the National Centers for Environmental Prediction reanalysis for a 10-yr period, 1984-93, and compare its convergence into two river basins with an independent dataset, river discharge (streamflow). Analysis focuses on two basins in the United States, the Upper Mississippi and the Ohio-Tennessee Basins, where the relatively high density of routine upper-air observations might be expected to give the reanalysis its closest rendition of the actual water transport. Over periods of several years, water input by the atmosphere should match water output from these basins in streamflow. However, in both basins an imbalance between the two with biases with respect to streamflow approaching 40% is found. The accuracy attributed to river discharge measurements averaged over several years and the apparent lack of significant multiyear storage in the basins lead us to conclude that the bias is largely an inaccuracy in the atmospheric transport. Temporal variability of atmospheric input and streamflow output shows somewhat better correspondence, with statistically significant correlations occurring for both basins on interannual and several-day timescales. The overall behavior suggests that the temporal variability of water transport depicted by the reanalysis can be used to gain insight into the actual variability of atmospheric transport, at least for well-observed regions such as the United States.

  14. Growth of arc in high-pressure, pulsed glow discharge by gas density depletion

    NASA Astrophysics Data System (ADS)

    Imada, Go; Yatsui, Kiyoshi; Masuda, Wataru

    2000-10-01

    Effects of gas density depletion on arc formation of high-pressure, pulsed glow discharge have been investigated by eliminating the other factors which may affect the discharge stability, such as shock waves, residual ions, electrode heating, and discharge products. The gas density depletion has been simulated by utilizing a subsonic gas flow between the curved electrodes combined with a convergent nozzle and a divergent diffuser. A comparison has been made on the discharge in the aerodynamically created gas density depletion with the second discharge in the double-pulse discharge within a stable gas. We have found that the large gas density depletion, Δρ/ρ0˜-3.6% corresponding to a pulse repetition rate (PRR) of ˜50 Hz, tends to cause an arc-like filament or an arc without the shocks, ions, electrode heating, and products. However, the second discharge in the double-pulse discharge becomes an arc in much smaller gas density depletion (Δρ/ρ0˜-1.2% corresponding to PRR ˜3 Hz). Therefore, the collapse of high-pressure, pulsed glow discharge is most likely caused by some factor other than the gas density depletion.

  15. Inactivation of MS2 bacteriophage by streamer corona discharge in water.

    PubMed

    Lee, Changha; Kim, Jaeeun; Yoon, Jeyong

    2011-02-01

    Electrical discharge processes are emerging as water treatment technologies applicable to both the degradation of organic contaminants as well as inactivation of pathogens. Particularly as a disinfection technology, electrical discharge processes do not produce toxic byproducts, and effectively inactivate a wide spectrum of microorganisms by multiple lethal actions generated by the formation of plasma channels. This study demonstrates the inactivation of a virus using the streamer corona discharge process (SCDP) with MS2 phage as a surrogate. A rapid inactivation of MS2 phage (i.e., approximately 4 log inactivation in 5 min) was observed in all experimental runs conducted. Discharge conditions such as applied voltage and storage capacitance significantly affected the inactivation efficiency of MS2 phage, whereas the influence of water quality parameters was minor. In order to elucidate the mechanism of MS2 phage inactivation, potentially lethal factors that can be generated by the SCDP were selected, and their roles in the inactivation of MS2 phage were examined. As a result, effects of UV radiation, chemical oxidants, and pulsed electric fields were found to be insignificant. The shockwave generated upon plasma channel formation appears to be the most important factor responsible for MS2 phage inactivation. PMID:21144553

  16. Final Report: Risk assessment for produced water discharges to Louisiana open bays

    SciTech Connect

    Meinhold, A.F.; DePhillips, M.P.; Holtzman, S.

    1996-03-01

    Potential human health and environmental impacts from discharges of produced water to the Gulf of Mexico are of concern to regulators at the State and Federal levels, the public, environmental interest groups and industry. Current and proposed regulations require a zero discharge limit for coastal facilities, based primarily on studies in low energy, poorly flushed environments. However, produced water discharges in coastal Louisiana include a number of open bay sites, where potential human health and environmental impacts are likely to be smaller than those demonstrated for low energy canal environments, but greater than the minimal impacts associated with offshore discharges. Additional data and assessments are needed to support risk managers at the State and Federal levels in the development of regulations that protect human health and the environment without unnecessary cost to the economic welfare of the region and the nation. This project supports the Natural Gas and Oil Initiative objectives to: (1) improve coordination on environmental research; (2) streamline State and Federal regulation; (3) enhance State, and Federal regulatory decision making capability; (4) enhance dialogue through industry/government/public partnerships; and (5) work with States and Native American Tribes.

  17. Table-top water-window soft X-ray microscope using a Z-pinching capillary discharge source

    NASA Astrophysics Data System (ADS)

    Nawaz, M. F.; Nevrkla, M.; Jancarek, A.; Torrisi, A.; Parkman, T.; Turnova, J.; Stolcova, L.; Vrbova, M.; Limpouch, J.; Pina, L.; Wachulak, P.

    2016-07-01

    The development and demonstration of a table-top transmission soft X-ray (SXR) microscope, using a laboratory incoherent capillary discharge source has been carried out. This Z-pinching capillary discharge water-window SXR source, is a first of its kind to be used for high spatial resolution microscopy at λ = 2.88 nm (430 eV) . A grazing incidence ellipsoidal condenser mirror is used for focusing of the SXR radiation at the sample plane. The Fresnel zone plate objective lens is used for imaging of the sample onto a back-illuminated (BI) CCD camera. The achieved half-pitch spatial resolution of the microscope approaches 100 nm, as demonstrated by the knife-edge test. Details about the source, and the construction of the microscope are presented and discussed. Additionally, the SXR images of various samples, proving applicability of such microscope for observation of objects in the nanoscale, are shown.

  18. Predictive analyses of ground-water discharges in the Willow Creek Watershed, northeast Nebraska

    USGS Publications Warehouse

    Dugan, Jack T.; Lappala, E.G.

    1978-01-01

    Ground-water discharge to Willow Creek in northeast Nebraska was predicted with a digital model of the ground-water/surface-water system. Recharge and irrigation requirements were determined with a model of the soil zone. The regional aquifer is Pliocene and Pleistocene sands and gravels. Water in the regional aquifer is unconfined in the western part of the watershed and confined in the eastern part. The confining layer is Pleistocene eolian silts with very fine sand interbeds overlying a basal clay. Where the regional aquifer is unconfined, perennial flow of Willow Creek is sustained by ground-water discharge. Where it is confined, the low hydraulic conductivity of the confining beds isolates the regional aquifer from Willow Creek. Adequate agreement between simulated and observed streamflows and water levels during 1975 and 1976 was obtained by modifying initial estimates of hydraulic conductivity and specific storage. The future perennial flow of Willow Creek was simulated by superimposing six patterns of ground-water withdrawals upon variations in recharge for a monthly climatic sequence identical with the period 1931-34. These analyses showed that the perennial monthly flows would be less than 12 cubic feet per second at least 50 percent of the time. (Woodard-USGS)

  19. Potential health implications of water resources depletion and sewage discharges in the Republic of Macedonia.

    PubMed

    Hristovski, Kiril D; Pacemska-Atanasova, Tatjana; Olson, Larry W; Markovski, Jasmina; Mitev, Trajce

    2016-08-01

    Potential health implications of deficient sanitation infrastructure and reduced surface water flows due to climate change are examined in the case study of the Republic of Macedonia. Changes in surface water flows and wastewater discharges over the period 1955-2013 were analyzed to assess potential future surface water contamination trends. Simple model predictions indicated a decline in surface water hydrology over the last half century, which caused the surface waters in Macedonia to be frequently dominated by >50% of untreated sewage discharges. The surface water quality deterioration is further supported by an increasing trend in modeled biochemical oxygen demand trends, which correspond well with the scarce and intermittent water quality data that are available. Facilitated by the climate change trends, the increasing number of severe weather events is already triggering flooding of the sewage-dominated rivers into urban and non-urban areas. If efforts to develop a comprehensive sewage collection and treatment infrastructure are not implemented, such events have the potential to increase public health risks and cause epidemics, as in the 2015 case of a tularemia outbreak. PMID:27441863

  20. Max Tech and Beyond: High-Intensity Discharge Lamps

    SciTech Connect

    Scholand, Michael

    2012-04-01

    High-intensity discharge (HID) lamps are most often found in industrial and commercial applications, and are the light source of choice in street and area lighting, and sports stadium illumination. HID lamps are produced in three types - mercury vapor (MV), high pressure sodium (HPS) and metal halide (MH). Of these, MV and MH are considered white-light sources (although the MV exhibits poor color rendering) and HPS produces a yellow-orange color light. A fourth lamp, low-pressure sodium (LPS), is not a HID lamp by definition, but it is used in similar applications and thus is often grouped with HID lamps. With the notable exception of MV which is comparatively inefficient and in decline in the US from both a sales and installed stock point of view; HPS, LPS and MH all have efficacies over 100 lumens per watt. The figure below presents the efficacy trends over time for commercially available HID lamps and LPS, starting with MV and LPS in 1930's followed by the development of HPS and MH in the 1960's. In HID lamps, light is generated by creating an electric arc between two electrodes in an arc tube. The particles in the arc are partially ionized, making them electrically conductive, and a light-emitting 'plasma' is created. This arc occurs within the arc tube, which for most HID lamps is enclosed within an evacuated outer bulb that thermally isolates and protects the hot arc tube from the surroundings. Unlike a fluorescent lamp that produces visible light through down-converting UV light with phosphors, the arc itself is the light source in an HID lamp, emitting visible radiation that is characteristic of the elements present in the plasma. Thus, the mixture of elements included in the arc tube is one critical factor determining the quality of the light emitted from the lamp, including its correlated color temperature (CCT) and color rendering index (CRI). Similar to fluorescent lamps, HID lamps require a ballast to start and maintain stable operating conditions, and

  1. Assessing the effects of treated and untreated urban discharges to estuarine and coastal waters applying selected biomarkers on caged mussels.

    PubMed

    de los Ríos, A; Pérez, L; Ortiz-Zarragoitia, M; Serrano, T; Barbero, M C; Echavarri-Erasun, B; Juanes, J A; Orbea, A; Cajaraville, M P

    2013-12-15

    To assess effects of urban discharges, biomarkers were measured in caged mussels in northern Iberian Peninsula. Lysosomal membrane stability and histopathology of gonad and digestive gland were analysed as general effect biomarkers. Exposure to specific pollutants was evaluated by autometallographical detection of metals, peroxisomal acyl-CoA oxidase activity, micronucleus test and transcription levels of vitellogenin and MT20 genes. Health status of mussels was impaired after 3 days of caging at the untreated outfall discharge and at the waste water treatment plant effluent discharge to the estuary. The most relevant finding was the significant up-regulation of vitellogenin gene transcription in male mussels exposed to the untreated outfall discharge. Metals and xenoestrogenic endocrine disruptors were bioavailable in some discharges and disturbed the health status of mussels. Biomarkers were effective in the assessment of effects of urban discharges and could be implemented in operative controls required to assess the risks associated to effluent discharges. PMID:24156823

  2. Numerical modelling of distribution the discharged heat water from thermal power plant on the aquatic environment

    NASA Astrophysics Data System (ADS)

    Issakhov, Alibek

    2016-06-01

    The paper presents a mathematical model of distribution the discharged heat water from thermal power plant under various operational capacities on the aquatic environment. It was solved by the Navier-Stokes and temperature equations for an incompressible fluid in a stratified medium were based on the splitting method by physical parameters which approximated by the finite volume method. The numerical solution of the equation system was divided into four stages. At the first step it was assumed that the momentum transfer carried out only by convection and diffusion. While the intermediate velocity field was solved by 5-step Runge-Kutta method. At the second stage, the pressure field was solved by found the intermediate velocity field. Whereas Poisson equation for the pressure field was solved by Jacobi method. The third step assumes that the transfer was carried out only by pressure gradient. Finally the fourth step of the temperature equation was also solved as motion equations, with 5-step Runge-Kutta method. The algorithm was parallelized on high-performance computer. The obtained numerical results of three-dimensional stratified turbulent flow were compared with experimental data. What revealed qualitatively and quantitatively approximately the basic laws of hydrothermal processes occurring in the reservoir-cooler.

  3. Assessment of the Impacts of Climate Change on Stream Discharge and Water Quality in an Arid, Urbanized Watershed

    NASA Astrophysics Data System (ADS)

    Ranatunga, T.; Tong, S.; Yang, J.

    2011-12-01

    Hydrologic and water quality models can provide a general framework to conceptualize and investigate the relationships between climate and water resources. Under a hot and dry climate, highly urbanized watersheds are more vulnerable to changes in climate, such as excess heat and drought. In this study, a comprehensive watershed model, Hydrological Simulation Program FORTRAN (HSPF), is used to assess the impacts of future climate change on the stream discharge and water quality in Las Vegas Wash in Nevada, the only surface water body that drains from the Las Vegas Valley (an area with rapid population growth and urbanization) to Lake Mead. In this presentation, the process of model building, calibration and validation, the generation of climate change scenarios, and the assessment of future climate change effects on stream hydrology and quality are demonstrated. The hydrologic and water quality model is developed based on the data from current national databases and existing major land use categories of the watershed. The model is calibrated for stream discharge, nutrients (nitrogen and phosphorus) and sediment yield. The climate change scenarios are derived from the outputs of the Global Climate Models (GCM) and Regional Climate Models (RCM) simulations, and from the recent assessment reports from the Intergovernmental Panel on Climate Change (IPCC). The Climate Assessment Tool from US EPA's BASINS is used to assess the effects of likely future climate scenarios on the water quantity and quality in Las Vegas Wash. Also the presentation discusses the consequences of these hydrologic changes, including the deficit supplies of clean water during peak seasons of water demand, increased eutrophication potentials, wetland deterioration, and impacts on wild life habitats.

  4. Upwelling of warm water in lakes due to lacustrine groundwater discharge

    NASA Astrophysics Data System (ADS)

    Marruedo Arricibita, Amaia I.; Lewandowski, Jörg; Krause, Stefan; Dämpfling, Hauke

    2016-04-01

    Detection of lacustrine groundwater discharge (LGD) is still a challenge. The buoyancy of warm groundwater during winter and early spring when lake water is colder and heavier than groundwater can be used for identification of groundwater upwelling related hotspots in surface waters by FO-DTS. FO-DTS has been successfully used to locate groundwater contributions at the sediment-water interface of lakes and rivers. Yet, FO-DTS has not been used to study 3D temperature patterns in lake water bodies. Still, qualitative and quantitative interpretations of groundwater fluxes are hampered by the lack of understanding how the groundwater upwelling signal propagates from the sediment-water interface through the water column to the water-air interface and what perturbations and signal losses occur along this pathway. In the present study, groundwater discharge to a surface water body was simulated in a mesocosm experiment. Under winter conditions water of 14° C to 16°C was discharged at the bottom of a 10x2.8 m mesocosm where surface water varied from 4°C -7.4°C. Four layers (20, 40, 60 and 80 cm above the sediment) of the 81 cm deep mesocosm were equipped with fibre-optic distributed temperature sensing (FO-DTS) for tracing thermal patterns in the mesocosm in order to: (1) analyze the propagation of the temperature signal through the water column by FO-DTS and (2) characterize the spatial distribution of groundwater-borne hot spots close to the pond surface by FO-DTS. Different LGD rates were simulated in order to establish the minimum rate of GW upwelling that can be reliably detected at the water surface by FO-DTS. The experiments also allow us to benchmark scale dependencies and adequacy of FO-DTS method. It also reveals that weather conditions can have important impacts on the detection of LGD at surface water-atmosphere interfaces at larger scales.

  5. Low-pressure electrical discharge experiment to simulate high-altitude lightning above thunderclouds

    NASA Technical Reports Server (NTRS)

    Jarzembski, M. A.; Srivastava, V.

    1995-01-01

    Recently, extremely interesting high-altitude cloud-ionosphere electrical discharges, like lightning above thunderstorms, have been observed from NASA's space shuttle missions and during airborne and ground-based experiments. To understand these discharges, a new experiment was conceived to simulate a thundercloud in a vacuum chamber using a dielectric in particulate form into which electrodes were inserted to create charge centers analogous to those in an electrified cloud. To represent the ionosphere, a conducting medium (metallic plate) was introduced at the top of the chamber. It was found that for different pressures between approximately 1 and 300 mb, corresponding to various upper atmospheric altitudes, different discharges occurred above the simulated thundercloud, and these bore a remarkable similarity to the observed atmospheric phenomena. At pressures greater than 300 mb, these discharges were rare and only discharges within the simulated thundercloud were observed. Use of a particulate dielectric was critical for the successful simulation of the high-altitude lightning.

  6. Bubble Phenomena caused by High Repetitive Plasmas in Water

    NASA Astrophysics Data System (ADS)

    Akiyama, Masahiro; Oikawa, Takuma; Fue, Masatoshi; Ogata, Ryoma; Takaki, Koich; Akiyama, Hidenori; Iwate Univ Team; Kumamoto Univ Collaboration

    2015-09-01

    Streamer discharges in water were generated by a pulsed power generator. The streamer shape changed depending on pulse repetition rate. Streamer discharges at 500 pulses per second (pps) resulted in a ball shape. Under this formation, small bubbles gather near the electrode tip. Our aims are the analysis and discussion of the bubble phenomena caused by high repetitive plasmas produced in water. Pulsed power with a maximum output of 1 J/pulse was applied to an electrode of 0.8 mm in diameter covered by an insulator of 2 mm thickness. The electrode was inserted into tap water with conductivity of 170 uS/cm. The polarity was positive. Phenomena, in which the resulting gas bubbles oscillate and gather, were found to have an important role in producing ball shape streamer discharges.

  7. Impact of sewage discharges on coastal water quality of Mumbai, India: present and future scenarios.

    PubMed

    Vijay, Ritesh; Mardikar, Trupti; Kumar, Rakesh

    2016-07-01

    The simulation study assesses the impact of sewage discharges on the present and predicted water quality of the Mumbai coast using MIKE 21. Water quality parameters in terms of dissolved oxygen (DO), biochemical oxygen demand (BOD) and faecal coliform (FC) are checked against specified standards. The simulation is validated for the present coastal hydrodynamics and observed water quality parameters. The validated model is further used for predicting scenarios in terms of upgradation in a pumping station and improvement in wastewater collection, treatment level and disposal systems. The water quality of the existing coastal environment does not conform to the stipulated standards but improves considerably in the prediction scenarios. However, despite a marked improvement in FC, it is not as per desired standards as no treatment for bacteria removal is considered. The simulation study emphasizes the need for exploring options like the reuse or recycle of treated effluent, as an effort for water conservation. PMID:27317055

  8. Rapid and direct electrochemical determination of Ni(II) in industrial discharge water.

    PubMed

    Ferancová, Adriana; Hattuniemi, Maarit K; Sesay, Adama M; Räty, Jarkko P; Virtanen, Vesa T

    2016-04-01

    Industrial water contains a number of contaminants, such as organic pollutants and heavy metals, which can significantly affect the quality of soil, ground and environmental waters. We have successfully optimized and tested an electrochemical method and sensor modified with dimethylglyoxime for monitoring of nickel(II). The detection limit was 0.03mg/L and determination limit was 0.09mg/L. Linear concentration range was observed from 0.06 to 0.5mg/L Ni(II) and it is suitable for the analysis of environmental waters. The effect of all parameters important for on-site measurements (such as interferences, presence of dissolved oxygen, temperature) was investigated and considered in the analysis of mine discharge water. Water samples were analyzed without any pretreatment or filtration. A low level of error (5.6%) was observed for analysis demonstrating the usability of the optimized sensor and method for on-site measurements. PMID:26686524

  9. Production characteristics of reactive oxygen/nitrogen species in water using atmospheric pressure discharge plasmas

    NASA Astrophysics Data System (ADS)

    Takahashi, Kazuhiro; Satoh, Kohki; Itoh, Hidenori; Kawaguchi, Hideki; Timoshkin, Igor; Given, Martin; MacGregor, Scott

    2016-07-01

    A pulsed discharge, a DC corona discharge, and a plasma jet are separately generated above a water surface, and reactive oxygen species and reactive nitrogen species (ROS/RNS) in the water are investigated. ROS/RNS in water after the sparging of the off-gas of a packed-bed dielectric barrier discharge (PB-DBD) are also investigated. H2O2, NO2 ‑, and NO3 ‑ are detected after plasma exposure and only NO3 ‑ after off-gas sparging. Short-lifetime species in plasma are found to play an important role in H2O2 and NO2 ‑ production and long-lifetime species in NO3 ‑ production. NO x may inhibit H2O2 production through OH consumption to produce HNO2 and HNO3. O3 does not contribute to ROS/RNS production. The pulsed plasma exposure is found to be effective for the production of H2O2 and NO2 ‑, and the off-gas sparging of the PB-DBD for the production of NO3 ‑.

  10. The TORE SUPRA Cryogenic System Behaviour During Long Plasma Discharges with a High Injected Energy

    SciTech Connect

    Henry, D.; Hertout, P.; Journeaux, J. Y.; Duchateau, J. L.; Reynaud, P.

    2006-04-27

    After the CIEL project completion including the upgrade of the plasma facing components and the water cooling system, the superconducting Tore Supra Tokamak achieved a world record of injected energy (1.1 GJ), during long duration (6 min) plasma discharges, which was enabled by the upgrade of the transfer system capacities, but also by the steady state toroidal field. The Tore Supra cryogenic refrigerator enables the toroidal field coils to be operated at nominal current along the full daily plasma operation shift. It has capacities of 300 W at 1.8 K, 750 W at 4.5 K and 30 kW at 80 K and was operated with a high reliability for more than 16 years. After a brief recall on the cryogenic refrigeration of the toroidal superconducting magnet, the distribution of the heat loads at the various levels of temperature (in standby mode 150W at 1.8 K and 200W at 4.5 K) is presented. The inventory of the calculated static and variable heat loads deposited within each part of toroidal field coils and thermal shields, is given with the factors of dependence. This analysis identifies and quantifies the major magnetic disturbances like a disruption (about 12 kJ onto the coils and 300 kJ onto the thick casings) which generate additional heat loads for the refrigerator.The measurements associated with the He II saturated bath pumping system, and the supercritical helium loop cooling the thick casings, allow us to verify thereafter the behaviour of the cryo-refrigerator during the long duration discharges, and the compliance with the theoretical model.The conclusions bring results also applicable to the cyoplant of future plant like ITER which will operate with long duration discharges.

  11. The TORE SUPRA Cryogenic System Behaviour During Long Plasma Discharges with a High Injected Energy

    NASA Astrophysics Data System (ADS)

    Henry, D.; Hertout, P.; Journeaux, J. Y.; Duchateau, J. L.; Reynaud, P.

    2006-04-01

    After the CIEL project completion including the upgrade of the plasma facing components and the water cooling system, the superconducting Tore Supra Tokamak achieved a world record of injected energy (1.1 GJ), during long duration (6 min) plasma discharges, which was enabled by the upgrade of the transfer system capacities, but also by the steady state toroidal field. The Tore Supra cryogenic refrigerator enables the toroidal field coils to be operated at nominal current along the full daily plasma operation shift. It has capacities of 300 W at 1.8 K, 750 W at 4.5 K and 30 kW at 80 K and was operated with a high reliability for more than 16 years. After a brief recall on the cryogenic refrigeration of the toroidal superconducting magnet, the distribution of the heat loads at the various levels of temperature (in standby mode 150W at 1.8 K and 200W at 4.5 K) is presented. The inventory of the calculated static and variable heat loads deposited within each part of toroidal field coils and thermal shields, is given with the factors of dependence. This analysis identifies and quantifies the major magnetic disturbances like a disruption (about 12 kJ onto the coils and 300 kJ onto the thick casings) which generate additional heat loads for the refrigerator. The measurements associated with the He II saturated bath pumping system, and the supercritical helium loop cooling the thick casings, allow us to verify thereafter the behaviour of the cryo-refrigerator during the long duration discharges, and the compliance with the theoretical model. The conclusions bring results also applicable to the cyoplant of future plant like ITER which will operate with long duration discharges.

  12. Impacts from oil and gas produced water discharges on the gulf of Mexico hypoxic zone.

    SciTech Connect

    Parker, M. E.; Satterlee, K.; Veil, J. A.; Environmental Science Division; ExxonMobil Production Co.; Shell Offshore

    2006-01-01

    Shallow water areas of the Gulf of Mexico continental shelf experience low dissolved oxygen (hypoxia) each summer. The hypoxic zone is primarily caused by input of nutrients from the Mississippi and Atchafalaya Rivers. The nutrients stimulate the growth of phytoplankton, which leads to reduction of the oxygen concentration near the sea floor. During the renewal of an offshore discharge permit used by the oil and gas industry in the Gulf of Mexico, the U.S. Environmental Protection Agency (EPA) identified the need to assess the potential contribution from produced water discharges to the occurrence of hypoxia. The EPA permit required either that all platforms in the hypoxic zone submit produced water samples, or that industry perform a coordinated sampling program. This paper, based on a report submitted to EPA in August 2005 (1), describes the results of the joint industry sampling program and the use of those results to quantify the relative significance of produced water discharges in the context of other sources on the occurrence of hypoxia in the Gulf of Mexico. In the sampling program, 16 facilities were selected for multiple sampling - three times each at one month intervals-- and another 34 sites for onetime sampling. The goal of the sampling program was to quantify the sources and amount of oxygen demand associated with a variety of Gulf of Mexico produced waters. Data collected included direct oxygen demand measured by BOD5 (5-day biochemical oxygen demand) and TOC (total organic carbon) and indirect oxygen demand measured by nitrogen compounds (ammonia, nitrate, nitrate, and TKN [total Kjeldahl nitrogen]) and phosphorus (total phosphorus and orthophosphate). These data will serve as inputs to several available computer models currently in use for forecasting the occurrence of hypoxia in the Gulf of Mexico. The output of each model will be compared for consistency in their predictions and then a semi-quantitative estimate of the relative significance of

  13. Temporal variability in domestic point source discharges and their associated impact on receiving waters.

    PubMed

    Richards, Samia; Withers, Paul J A; Paterson, Eric; McRoberts, Colin W; Stutter, Marc

    2016-11-15

    Discharges from the widely distributed small point sources of pollutants such as septic tanks contribute to microbial and nutrient loading of streams and can pose risks to human health and stream ecology, especially during periods of ecological sensitivity. Here we present the first comprehensive data on the compositional variability of septic tank effluents (STE) as a potential source of water pollution during different seasons and the associated links to their influence on stream waters. To determine STE parameters and nutrient variations, the biological and physicochemical properties of effluents sampled quarterly from 12 septic tank systems were investigated with concurrent analyses of upstream and downstream receiving waters. The study revealed that during the warmer dryer months of spring and summer, effluents were similar in composition, as were the colder wetter months of autumn and winter. However, spring/summer effluents differed significantly (P<0.05) from autumn/winter for concentrations of biological oxygen demand (BOD), arsenic, barium (Ba), cobalt, chromium, manganese, strontium (Sr), titanium, tungsten (W) and zinc (Zn). With the exception of BOD, Ba and Sr which were greater in summer and spring, the concentrations of these parameters were greater in winter. Receiving stream waters also showed significant seasonal variation (P≤0.05) in alkalinity, BOD, dissolved organic carbon, sulphate, sulphur, lithium, W, Zn and Escherichiacoli abundance. There was a clear significant influence of STE on downstream waters relative to upstream from the source (P<0.05) for total suspended solids, total particulate P and N, ammonium-N, coliforms and E. coli. The findings of this study found seasonal variation in STE and place effluent discharges as a factor affecting adjacent stream quality and call for appropriate measures to reduce or redirect STE discharges away from water courses. PMID:27474989

  14. EVALUATING THE EFFECTS OF UPSTREAM DISCHARGERS ON DOWNSTREAM WATER SUPPLIES: A SOURCE WATER PROTECTION MODEL

    EPA Science Inventory

    Source water protection is a component of the 1996 Amendments to the Safe Drinking Water Act. Drinking water utilities have adopted widely different philosophies for source water protection. the City of New York, with large upland water reservoirs, is investing millions of doll...

  15. Nutrient Enrichment in Estuaries from Discharge of Shallow Ground Water, Mt. Desert Island, Maine

    USGS Publications Warehouse

    Culbertson, Charles W.; Huntington, Thomas G.; Caldwell, James M.

    2007-01-01

    Nutrient enrichment from atmospheric deposition, agricultural activities, wildlife, and domestic sources is a concern at Acadia National Park because of the potential problem of water-quality degradation and eutrophication in its estuaries. Water-quality degradation has been observed at the Park?s Bass Harbor Marsh estuary but not in Northeast Creek estuary. Previous studies at Acadia National Park have estimated nutrient inputs to estuaries from atmospheric deposition and surface-water runoff, but the importance of shallow ground water that may contain nutrients derived from domestic or other sources is unknown. Northeast Creek and Bass Harbor Marsh estuaries were studied to (1) identify shallow ground-water seeps, (2) assess the chemistry of the water discharged from selected seeps, and (3) assess the chemistry of ground water in shallow ground-water hyporheic zones. The hyporheic zone is defined here as the region beneath and lateral to a stream bed, where there is mixing of shallow ground water and surface water. This study also provides baseline chemical data for ground water in selected bedrock monitoring wells and domestic wells on Mt. Desert Island. Water samples were analyzed for concentrations of nutrients, wastewater compounds, dissolved organic carbon, pH, dissolved oxygen, temperature and specific conductance. Samples from bedrock monitoring wells also were analyzed for alkalinity, major cations and anions, and trace metals. Shallow ground-water seeps to Northeast Creek and Bass Harbor Marsh estuaries at Acadia National Park were identified and georeferenced using aerial infrared digital imagery. Monitoring included the deployment of continuously recording temperature and specific conductance sensors in the seep discharge zone to access marine or freshwater signatures related to tidal flooding, gradient-driven shallow ground-water flow, or shallow subsurface flow related to precipitation events. Many potential shallow ground-water discharge zones were

  16. Evidence of persistent patchy submarine ground water discharge in the intertidal zone

    NASA Astrophysics Data System (ADS)

    Welti, Nina; Hayes, Matthew; Poh, Seng; Lockington, David

    2013-04-01

    We report on circular beach mounds, which we have called 'Wonky Mounds' in colloquial reference to locally known seafloor depressions. Two mounds have been identified in the intertidal zone off of North Stradbroke Island, located in Moreton Bay near Brisbane, Australia. They are persistent sand mounds with a diameter of 5-6m and a height of ca. 30cm relative to the surrounding beach and have not been previously documented. While these features resemble seafloor depressions which can be substantial sites for submarine groundwater discharge (SGD), we report on convex mounds at the order of the meter scale which demonstrate a heterogeneous patchiness at the local scale. Preliminary results from 222Rn, conductivity, and temperature measurements indicate that fresh groundwater, originating from the island, may flow from these mounds. Although previous studies have stressed the importance of SGD flows for nutrient delivery off of coastal shelves, this linkage between the fresh aquifer and intertidal waters are a new source of nutrient delivery that has not previously been considered in either hydrological or biogeochemical models. While total freshwater input into the world's oceans is dominated by riverine discharge, the input of nutrients from SGD is disproportionally large due to its elevated nutrient loads. We consider the local scale ecosystems' patchiness and heterogeneity in regards to the possible pathways of localized SGD discharge and the biogeochemical ramifications of discrete patchy freshwater discharge into the intertidal zone.

  17. Discharge, water quality, and native fish abundance in the Virgin River, Utah, Nevada, and Arizona, in support of Pah Tempe Springs discharge remediation efforts

    USGS Publications Warehouse

    Miller, Matthew P.; Lambert, Patrick M.; Hardy, Thomas B.

    2014-01-01

    Pah Tempe Springs discharge hot, saline, low dissolved-oxygen water to the Virgin River in southwestern Utah, which is transported downstream to Lake Mead and the Colorado River. The dissolved salts in the Virgin River negatively influence the suitability of this water for downstream agricultural, municipal, and industrial use. Therefore, various remediation scenarios to remove the salt load discharged from Pah Tempe Springs to the Virgin River are being considered. One concern about this load removal is the potential to impact the ecology of the Virgin River. Specifically, information is needed regarding possible impacts of Pah Tempe Springs remediation scenarios on the abundance, distribution, and survival of native fish in the Virgin River. Future efforts that aim to quantitatively assess how various remediation scenarios to reduce the load of dissolved salts from Pah Tempe Springs into the Virgin River may influence the abundance, distribution, and survival of native fish will require data on discharge, water quality, and native fish abundance. This report contains organized accessible discharge, water quality, and native fish abundance data sets from the Virgin River, documents the compilation of these data, and discusses approaches for quantifying relations between abiotic physical and chemical conditions, and fish abundance.

  18. Concentration-Discharge Patterns Revealed from High Resolution Nitrate Measurements in Agricultural Landscapes

    NASA Astrophysics Data System (ADS)

    Boland, S. J.; Basu, N. B.

    2012-12-01

    Riverine export of nutrients is a major component of nutrient cycles, particularly with respect to nitrogen; ~ 25 percent of terrestrially applied nitrogen (N) is removed via riverine export. Understanding the patterns in N export during a storm event is critical for developing a conceptual model of the dominant processes and pathways of N transformation, and designing appropriate management strategies to mitigate N pollution in streams and receiving water bodies. Most studies however, are limited by the lack of high-resolution water quality data to elucidate these pathways and mechanisms. We explored concentration-discharge relationships using high-resolution (15 minute) discharge (Q) and nitrate concentration (C) data (measured using an in-situ Nitratax Sonde) at multiple nested scales (from 151.3 km2 to 8900 km2) in two watersheds in Iowa: Clear Creek Watershed and the Raccoon River watershed. Three distinct regimes of nitrate transport were revealed: (1) a linear regime in which C increases with increasing Q, (2) a saturation regime in which C remains constant against increasing Q, and (3) a dilution regime in which concentration decreases as Q increases. The tight clustering of the data along these patterns is indicative of emergent behavior in such human-dominated systems. All three regimes were apparent in the Raccoon River Watershed, while only the saturation and dilution regimes were apparent in the Clear Creek Watershed. We hypothesize that surface flow is dominant in the Clear Creek Watershed leading to a saturation/dilution regimes, while subsurface flow is dominant in the more heavily tile-drained Raccoon River Watershed, leading to the occurrence of all three regimes. A parsimonious model was developed to test the hypothesis and develop C-Q patterns as a function of the partitioning of flow through the different pathways.

  19. Annual ground-water discharge by evapotranspiration from areas of spring-fed riparian vegetation along the eastern margin of Death Valley, 2000-02

    USGS Publications Warehouse

    Laczniak, Randell J.; Smith, J. LaRue; DeMeo, Guy A.

    2006-01-01

    Flow from major springs and seeps along the eastern margin of Death Valley serves as the primary local water supply and sustains much of the unique habitat in Death Valley National Park. Together, these major spring complexes constitute the terminus of the Death Valley Regional Ground-Water Flow System--one of the larger flow systems in the Southwestern United States. The Grapevine Springs complex is the least exploited for water supply and consequently contains the largest area of undisturbed riparian habitat in the park. Because few estimates exist that quantify ground-water discharge from these spring complexes, a study was initiated to better estimate the amount of ground water being discharged annually from these sensitive, spring-fed riparian areas. Results of this study can be used to establish a basis for estimating water rights and as a baseline from which to assess any future changes in ground-water discharge in the park. Evapotranspiration (ET) is estimated volumetrically as the product of ET-unit (general vegetation type) acreage and a representative ET rate. ET-unit acreage is determined from high-resolution multi-spectral imagery; and a representative ET rate is computed from data collected in the Grapevine Springs area using the Bowen-ratio solution to the energy budget, or from rates given in other ET studies in the Death Valley area. The ground-water component of ET is computed by removing the local precipitation component from the ET rate. Two different procedures, a modified soil-adjusted vegetation index using the percent reflectance of the red and near-infrared wavelengths and land-cover classification using multi-spectral imagery were used to delineate the ET units within each major spring-discharge area. On the basis of the more accurate procedure that uses the vegetation index, ET-unit acreage for the Grapevine Springs discharge area totaled about 192 acres--of which 80 acres were moderate-density vegetation and 112 acres were high

  20. Zero Liquid Discharge (ZLD) System for Flue-Gas Derived Water From Oxy-Combustion Process

    SciTech Connect

    Sivaram Harendra; Danylo Oryshchyn; Thomas Ochs; Stephen J. Gerdemann; John Clark

    2011-10-16

    Researchers at the National Energy Technology Laboratory (NETL) located in Albany, Oregon, have patented a process - Integrated Pollutant Removal (IPR) that uses off-the-shelf technology to produce a sequestration ready CO{sub 2} stream from an oxy-combustion power plant. Capturing CO{sub 2} from fossil-fuel combustion generates a significant water product which can be tapped for use in the power plant and its peripherals. Water condensed in the IPR{reg_sign} process may contain fly ash particles, sodium (from pH control), and sulfur species, as well as heavy metals, cations and anions. NETL is developing a treatment approach for zero liquid discharge while maximizing available heat from IPR. Current treatment-process steps being studied are flocculation/coagulation, for removal of cations and fine particles, and reverse osmosis, for anion removal as well as for scavenging the remaining cations. After reverse osmosis process steps, thermal evaporation and crystallization steps will be carried out in order to build the whole zero liquid discharge (ZLD) system for flue-gas condensed wastewater. Gypsum is the major product from crystallization process. Fast, in-line treatment of water for re-use in IPR seems to be one practical step for minimizing water treatment requirements for CO{sub 2} capture. The results obtained from above experiments are being used to build water treatment models.

  1. Water discharged from the gulf stream north of Cape Hatteras. (Reannouncement with new availability information)

    SciTech Connect

    Churchill, J.H.; Cornillon, P.C.

    1991-12-31

    Satellite radiometer-derived sea surface temperature images together with moored instrument and hydrographic survey data indicate that water ejected from the Gulf Stream often occupies the upper 200 m of the water column over the continental slope between Cape Hatteras and Hudson Canyon. At times this water resembles the energetic Gulf Stream frontal eddies commonly seen to the south of Cape Hatteras. However, many of the observed parcels of this water differ markedly from frontal eddies and Gulf Stream warm-core rings and so appear to form a class of discharged Gulf Stream water distinct from any previously reported. These parcels generally cover a broad area (compared with frontal eddies), contain relatively weak currents (generally < 40 cm/s at 100 m), and are remarkably long-lived (sometimes distinguishable for more than 2 months). Sanity anomaly distributions indicate that despite their persistence, these water masses contain intrusions of and mix with surrounding lower-salinity water, particularly in the upper So m. Continuity of various tracers along surfaces reveals that the discharged Gulf Stream water observed near the sea surface originated within the nutrient-bearing stratum of the Gulf Stream, having upwelled hundreds of meters along density surfaces. As a result, it tends to enhance nutrient concentrations over the continental slope, to a significant extent at 100 m depth but only marginally at 50 m depth. By contrast, this water does not carry unusually large kinetic energy densities into the slope region, but apparently gives up a good deal of kinetic energy, on the order of 10,000 sq cm/sec sq. per unit mass, while leaving the Gulf Stream.

  2. 220Rn as a method for identifying point sources of groundwater discharge: Expanding the dissolved gas tool kit in groundwater stream water interactions. (Invited)

    NASA Astrophysics Data System (ADS)

    Gardner, P.

    2013-12-01

    The most commonly used dissolved gas environmental tracer technique for estimating groundwater discharge to streams is 222Rn. 222Rn has very low background in surface water and has a relatively long retention time in stream water, providing a high sensitivity for detecting groundwater discharge. Given the gas exchange velocity and half-life of 222Rn groundwater input signal can persist for over 5 km, making identification of point source discharge difficult. 220Rn (Thoron), is produced in the subsurface along with 222Rn, but has a half-life of 55.6s and decays away rapidly once it enters stream water. Thus, 220Rn is an ideal tracer for identifying point locations of groundwater discharge. 220 can be measured in conjunction with 222Rn providing a convenient methodology for identifying diffuse and point discharges of groundwater. The conditions required for measuring 220Rn, methodology for measuring 220Rn and characteristics of 222Rn and 220Rn signals in groundwater-stream water applications will be discussed. Initial results from a field investigation utilizing these tracers in the Jemez River in Northern New Mexico will be presented. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  3. Fueling Requirements for Steady State high butane current fraction discharges

    SciTech Connect

    R.Raman

    2003-10-08

    The CT injector originally used for injecting CTs into 1T toroidal field discharges in the TdeV tokamak was shipped PPPL from the Affiliated Customs Brokers storage facility in Montreal during November 2002. All components were transported safely, without damage, and are currently in storage at PPPL, waiting for further funding in order to begin advanced fueling experiments on NSTX. The components are currently insured through the University of Washington. Several technical presentations were made to investigate the feasibility of the CT injector installation on NSTX. These technical presentations, attached to this document, were: (1) Motivation for Compact Toroida Injection in NSTX; (2) Assessment of the Engineering Feasibility of Installing CTF-II on NSTX; (3) Assessment of the Cost for CT Installation on NSTX--A Peer Review; and (4) CT Fueling for NSTX FY 04-08 steady-state operation needs.

  4. Improved comfinement in high-density ohmic discharges in ASDEX

    SciTech Connect

    Soeldner, F.X.; Mueller, E.R.; Wagner, F.; Bosch, H.S.; Eberhagen, A.; Fahrbach, H.U.; Fussmann, G.; Gehre, O.; Gentle, K.; Gernhardt, J.; and others

    1988-08-29

    The unsaturated linear rise of the energy confinement time with density, tau/sub E/approx.n-bar/sub e/, up to the density limit is recovered in Ohmically heated, discharges in ASDEX. Improvement of a factor of 2 is reached with tau/sub E/approx. =150 ms at n-bar/sub e/ = 5 x 10/sup 13/ cm/sup -3/. The improved state is characterized by peaked density profiles. The ion heat diffusivity decreases to the neoclassical value. The parameter eta/sub i/ = L/sub =//L/sub =/, governing the onset of ion-temperature-gradient modes, falls to the stability threshold. The improvement in confinement might therefore be attributed to the stabilization of eta/sub i/ modes.

  5. Research on characteristics of electromagnetic radiation of corona discharges from high voltage transmission lines

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Liu, Shang-he; Wei, Ming; Hu, Xiao-feng

    2013-03-01

    With the development and application of ultra high voltage electric power transmitting technology, harmful effects of corona discharges to the safe and stable operation of the ultra high voltage (UHV) transmission lines should be considered. In this paper, the radiation law of corona discharges was studied by theoretical analysis and laboratory simulation. Correlated conclusions include that the waveform of corona discharges is in attenuated oscillation mode, the signal of the radiation field increases with increasing charging voltage, whereas the signal amplitude the antenna receives is attenuated with the distance from 3 m to 24 m.

  6. Atlantic water intrusions linked to NAO modulate Greenland Ice Sheet discharge dynamics

    NASA Astrophysics Data System (ADS)

    Christoffersen, Poul; Mugford, Ruth; Seale, Anthony; Heywood, Karen; Joughin, Ian; Dowdeswell, Julian; Syvitski, James; Luckman, Adrian

    2010-05-01

    Major outlet glaciers in the Greenland Ice Sheet have experienced rapid fluctuations in speed and discharge over the last decade. The triggering mechanism of abrupt speed-up events is not firmly established, but synchronous occurrences and numerical simulations of response dynamics suggest an oceanographic cause. Here, we show that warm Atlantic water was present inside Kangerdlugssuaq Fjord, East Greenland, a few months before the sudden retreat of Kangerdlugssuaq Glacier in 2004. Using temperature and salinity from the ¼ degree NEMO ocean model and hydrographic data collected in previous years, we show that inflow of warm, saline Atlantic water to the East Greenland continental shelf may be a seasonal mechanism and that the extent and coastal proximity of Atlantic water intrusions may be governed by the North Atlantic Oscillation (NAO). To investigate the possible impact of these intrusions, we developed an automated procedure for identifying calving margins from MODIS data (2000-2008), allowing for the delineation of calving margins in 100,000+ images of East Greenland. This region-wide assessment of glacier fluctuations showed rapid retreat by an average of 2.9 km over 2001 to 2005 for the glaciers exposed to Atlantic water intrusions opposed to average retreat of just 0.3 km for glaciers unaffected by such inflows. The modeled extent of Atlantic water intrusions and the mapped extent of rapid glacier change are consistent with the recent attribution of sustained mass losses in southeast Greenland to increased discharge. Although our data suggest that NAO impacts on ice sheet discharge could be large, they also show that the influence is geographically confined.

  7. [Spectroscopic study on the high voltage fast pulsed discharge of nitrogen, ammonia or their mixture].

    PubMed

    Liu, Z P; Wang, P N; Yang, W D; Zheng, J B; Li, F M

    2001-10-01

    The emission spectra from the pulsed discharge plasma of nitrogen, ammonia or their mixture were measured. In the discharge of pure nitrogen gas, as the pressure increased, the discharge volume decreased and more dissociation of nitrogen molecules occurred due to the higher energy density. In the discharge of ammonia, N,N+ and NH+ were observed, but no NH2 and NH3 were detected, indicating that ammonia, which has the lower dissociation and ionization energies as compared to nitrogen, was highly dissociated. The discharge of the mixture of N2 and NH3 was also studied. The dependence of the dissociation of nitrogen on the ratio of nitrogen to ammonia was investigated by emission spectra. The optimal ratio for nitrogen dissociation was obtained. The advantage of using the mixture of nitrogen and ammonia in the synthesis of nitrides was discussed. PMID:12945317

  8. Are the argon metastables important in high power impulse magnetron sputtering discharges?

    SciTech Connect

    Gudmundsson, J. T.; Lundin, D.; Minea, T. M.; Stancu, G. D.; Brenning, N.

    2015-11-15

    We use an ionization region model to explore the ionization processes in the high power impulse magnetron sputtering (HiPIMS) discharge in argon with a titanium target. In conventional dc magnetron sputtering (dcMS), stepwise ionization can be an important route for ionization of the argon gas. However, in the HiPIMS discharge stepwise ionization is found to be negligible during the breakdown phase of the HiPIMS pulse and becomes significant (but never dominating) only later in the pulse. For the sputtered species, Penning ionization can be a significant ionization mechanism in the dcMS discharges, while in the HiPIMS discharge Penning ionization is always negligible as compared to electron impact ionization. The main reasons for these differences are a higher plasma density in the HiPIMS discharge, and a higher electron temperature. Furthermore, we explore the ionization fraction and the ionized flux fraction of the sputtered vapor and compare with recent experimental work.

  9. Influence of sodium carbonate on decomposition of formic acid by pulsed discharge plasma inside bubble in water

    NASA Astrophysics Data System (ADS)

    Iwabuchi, Masashi; Takahashi, Katsuyuki; Takaki, Koichi; Satta, Naoya

    2016-07-01

    The influence of sodium carbonate on the decomposition of formic acid by discharge inside bubbles in water was investigated experimentally. Oxygen or argon gases were injected into the water through a vertically positioned glass tube, in which the high-voltage wire electrode was placed to generate plasmas at low applied voltage. The concentration of formic acid was determined by ion chromatography. In the case of sodium carbonate additive, the pH increased owing to the decomposition of the formic acid. In the case of oxygen injection, the percentage of conversion of formic acid increased with increasing pH because the reaction rate of ozone with formic acid increased with increasing pH. In the case of argon injection, the percentage of conversion was not affected by the pH owing to the high rate loss of hydroxyl radicals.

  10. High electrical permittivity of ultrapure water at the water-platinum interface

    PubMed Central

    POLLACK, GERALD H.

    2014-01-01

    The discharge of a platinum parallel-plate capacitor filled with ultrapure water has been measured. The observed discharge trend can be described by a Modified Poisson-Boltzmann Equation (MPB) only when the voltage is very low. Increasing the applied voltage creates an “exclusion zone,” in which the MPB equation no longer fits, and the system capacitance shows a dependence on the spacing between the two platinum plates. The permittivity of water, calculated considering the system as a plane capacitor, appears to be very high. This implies that the exclusion zone could have extraordinary dielectric properties. PMID:25258452

  11. High electrical permittivity of ultrapure water at the water-platinum interface

    NASA Astrophysics Data System (ADS)

    Musumeci, Francesco; Pollack, Gerald H.

    2014-10-01

    The discharge of a platinum parallel-plate capacitor filled with ultrapure water has been measured. The observed discharge trend can be described by a Modified Poisson-Boltzmann Equation (MPB) only when the voltage is very low. Increasing the applied voltage creates an ‘exclusion zone' in which the MPB equation no longer fits, and the system capacitance shows a dependence on the spacing between the two platinum plates. The permittivity of water, calculated considering the system as a plane capacitor, appears to be very high. This implies that the exclusion zone could have extraordinary dielectric properties.

  12. High electrical permittivity of ultrapure water at the water-platinum interface.

    PubMed

    Musumeci, Francesco; Pollack, Gerald H

    2014-10-01

    The discharge of a platinum parallel-plate capacitor filled with ultrapure water has been measured. The observed discharge trend can be described by a Modified Poisson-Boltzmann Equation (MPB) only when the voltage is very low. Increasing the applied voltage creates an "exclusion zone," in which the MPB equation no longer fits, and the system capacitance shows a dependence on the spacing between the two platinum plates. The permittivity of water, calculated considering the system as a plane capacitor, appears to be very high. This implies that the exclusion zone could have extraordinary dielectric properties. PMID:25258452

  13. Direct Hydrocarbon Detection of Produced Formation Water Discharge on the Northwest Shelf, Australia

    NASA Astrophysics Data System (ADS)

    Holdway, D.; Heggie, D. T.

    2000-03-01

    Rapid and continuous direct hydrocarbon detection (DHD) of benzene, toluene and total C 1-C 6light hydrocarbons was used to map the dispersion of produced formation water (PFW) discharged from a petroleum production platform into near-surface waters of the Northwest Shelf of Australia. These hydrocarbon components are sensitive tracers of PFW discharge. Analyses at 2 minute intervals at a typical ship speed of 3 knots provided a C 1-C 6benzene and toluene sample every 180 m of ship travel. The PFW discharge was mapped in a NNW and SSE direction on both the ebb and flood tides to about 10 km from the production platform. A net westerly drift of the plume was evident on both the ebb and flood tides toward the Montebello Islands and Varanus Is., rather than toward the east and the mainland. Measured dilution of hydrocarbons at distances less than 1 km from the platform, indicated that dispersion rates appear to be benzene> toluene>C1-C6, where typical dilution of total C1-C6 hydrocarbons was over 2500 times, and benzene and toleune, over 10 000 and 20 000 times respectively. Vertical profiles of PFW hydrocarbons showed that the PFW plume was primarily a surface to mid-depth feature with most hydrocarbons confined to the top 12 m. Beyond 1 km, all hydrocarbons were well mixed vertically at only slightly elevated levels with characteristic dispersion half-distances of about 3·5 km on a spring (3 m) tide.

  14. Illegal discharges in Spanish waters. Analysis of the profile of the Alleged Offending Vessel.

    PubMed

    Martín Alonso, J M; Ortega Piris, Andrés; Pérez Labajos, Carlos

    2015-08-15

    There is at present a growing concern, on an international level, over environmental offences caused by oil discharges into the sea from vessels. The objective of the Spanish Maritime Administration is to prevent the illegal discharges of polluting substances in Spanish maritime waters by vessels in transit. To combat such discharges, since 2007 Spain has reinforced its means of response with the use of aircrafts that provide services of maritime surveillance, identifying the Alleged Offending Vessels and acting as a deterrent. The objective of the present study is both to introduce the concept and to analyze certain aspects of the so-called "Alleged Offending Vessel" (AOV) that have been detected within Spanish Search and Rescue (SAR) jurisdiction waters in the period 2008-2012, in order to build a profile of such a vessel. For this purpose, an analysis methodology is formalized based on the GINI index and Lorenz curves, associated with certain aspects of vessels: type, flag and sailing area. PMID:26070959

  15. Recharge Area, Base-Flow and Quick-Flow Discharge Rates and Ages, and General Water Quality of Big Spring in Carter County, Missouri, 2000-04

    USGS Publications Warehouse

    Imes, Jeffrey L.; Plummer, L. Niel; Kleeschulte, Michael J.; Schumacher, John G.

    2007-01-01

    Exploration for lead deposits has occurred in a mature karst area of southeast Missouri that is highly valued for its scenic beauty and recreational opportunities. The area contains the two largest springs in Missouri (Big Spring and Greer Spring), both of which flow into federally designated scenic rivers. Concerns about potential mining effects on the area ground water and aquatic biota prompted an investigation of Big Spring. Water-level measurements made during 2000 helped define the recharge area of Big Spring, Greer Spring, Mammoth Spring, and Boze Mill Spring. The data infer two distinct potentiometric surfaces. The shallow potentiometric surface, where the depth-to-water is less than about 250 feet, tends to mimic topographic features and is strongly controlled by streams. The deep potentiometric surface, where the depth-to-water is greater than about 250 feet represents ground-water hydraulic heads within the more mature karst areas. A highly permeable zone extends about 20 mile west of Big Spring toward the upper Hurricane Creek Basin. Deeper flowing water in the Big Spring recharge area is directed toward this permeable zone. The estimated sizes of the spring recharge areas are 426 square miles for Big Spring, 352 square miles for Greer Spring, 290 square miles for Mammoth Spring, and 54 square miles for Boze Mill Spring. A discharge accumulation curve using Big Spring daily mean discharge data shows no substantial change in the discharge pattern of Big Spring during the period of record (water years 1922 through 2004). The extended periods when the spring flow deviated from the trend line can be attributed to prolonged departures from normal precipitation. The maximum possible instantaneous flow from Big Spring has not been adequately defined because of backwater effects from the Current River during high-flow conditions. Physical constraints within the spring conduit system may restrict its maximum flow. The largest discharge measured at Big Spring

  16. Charging and Discharging of Amorphous Solid Water Ice: Effects of Porosity

    NASA Astrophysics Data System (ADS)

    Bu, Caixia; Baragiola, Raul A.

    2015-11-01

    Introduction: Amorphous solid water (ASW) is abundant on Saturn’s icy satellites and rings [1,2], where it is subject to bombardment of energetic ions, electrons, and photons; together with secondary electron and ion emission, this may leave the surfaces charged. Surface potential can affect the flux of incoming charged particles, altering surface evolution. We examined the role of porosity [3] on electrostatic charging and discharging of ASW films at 30-140 K.Experiment: Experiments were performed in ultra-high vacuum [4]. ASW films were deposited at 30 K onto a liquid-He-cooled quartz crystal microbalance (QCM). Film porosity was calculated from the areal mass via the QCM and thickness via a UV-visible interferometry. ASW films were charged at 30 K using 500 eV He+. Surface potentials (Vs) of the films were measured with a Kelvin probe, and infrared spectra were collected using a Fourier transform infrared spectrometer.Results: We measured Vs of the ASW film at 30 K as a function of ion fluence (F). The Vs(F) deviates from a straight line at low fluence, attributed to emitted secondary electrons due to the negative polarization voltage [5,6], and increases linearly when the Vs is positive. We also measured Vs as a function of annealing temperature. We prepared ASW films with various porosities by annealing the films to different temperatures (Ta) prior to irradiation or varying the vapor-beam incidence angle (θ). Upon heating, we observed sharp decreases of the Vs at temperatures that strongly depend on Ta and θ. Decreases of the infrared absorbance of the dangling OH bands of the charged film share similar trends as that of the Vs. We propose a model that includes porosity for electrostatic charging/discharging of ASW films at temperatures below 100 K. Results are applicable to the study of plasma-surface interactions of icy satellites and rings.References: [1] Jurac et al., J. Geophys. Res. 100, 14821 (1995); [2] A. L. Graps et al., Space Sci. Rev. 137, 435

  17. Capacity fade study of lithium-ion batteries cycled at high discharge rates

    NASA Astrophysics Data System (ADS)

    Ning, Gang; Haran, Bala; Popov, Branko N.

    Capacity fade of Sony US 18650 Li-ion batteries cycled using different discharge rates was studied at ambient temperature. The capacity losses were estimated after 300 cycles at 2 C and 3 C discharge rates and were found to be 13.2 and 16.9% of the initial capacity, respectively. At 1 C discharge rate the capacity lost was only 9.5%. The cell cycled at high discharge rate (3 C) showed the largest internal resistance increase of 27.7% relative to the resistance of the fresh cells. The rate capability losses were proportional with the increase of discharge rates. Half-cell study and material and charge balances were used to quantify the capacity fade due to the losses of primary active material (Li +), the secondary active material (LiCoO 2/C)) and rate capability losses. It was found that carbon with 10.6% capacity loss after 300 cycles dominates the capacity fade of the whole cell at high discharge rates (3 C). A mechanism is proposed which explains the capacity fade at high discharge rates.

  18. Dielectric barrier discharge for multi-point plasma-assisted ignition at high pressures.

    PubMed

    Shcherbanev, S A; Stepanyan, S A; Popov, N A; Starikovskaia, S M

    2015-08-13

    Nanosecond surface dielectric barrier discharge (nSDBD) is an efficient tool for a multi-point plasma-assisted ignition of combustible mixtures at elevated pressures. The discharge develops as a set of synchronously propagated from the high-voltage electrode charged channels (streamers), with a typical density up to a few streamers per millimetre of the length of the electrode. In combustible mixtures, nSDBD initiates numerous combustion waves propagating from the electrode. Very little is known about nSDBD at high pressures. This work presents a comparative experimental study of the surface dielectric barrier discharge initiated by high-voltage pulses (U=±(20-60) kV) of different polarities in air at elevated pressures (P=1-6 atm). Discharge morphology, deposited energy and velocity of the discharge front propagation are analysed. Differences between the discharges of positive and negative polarity, as well as the changes in the discharge morphology with changing of a gas mixture composition. PMID:26170430

  19. Influence of St. Lawrence River discharge on the circulation and hydrography in Canadian Atlantic waters

    NASA Astrophysics Data System (ADS)

    Ohashi, Kyoko; Sheng, Jinyu

    2013-04-01

    This study examines the effects of freshwater discharge from the St. Lawrence River (SLR) on the three-dimensional circulation and hydrography in Canada's Atlantic waters using a regional shelf circulation model based on the Princeton Ocean Model. The study region comprises the Gulf of St. Lawrence, the Scotian Shelf, and the Gulf of Maine. The model forcing includes atmospheric forcing at the sea surface; tidal elevation and currents at the lateral open boundaries; and freshwater discharge from the SLR and other major rivers in the region. The forcing at the lateral open boundaries also includes non-tidal currents as well as temperature and salinity fields produced by a coarse-resolution circulation model for the northwest Atlantic. The shelf circulation model is integrated for 5 years (1999-2003); the simulated hydrography and circulation during the last 4 years are compared to observations to assess the model's performance. Three additional model runs are made, called the climate, wet, and dry runs, in which the SLR discharge values specified in the model are respectively the long-term mean and the long-term mean plus or minus 3.5 standard deviations. Model results from the climate run demonstrate that the variability of freshwater flux in the St. Lawrence Estuary takes ˜100 days to reach Cabot Strait; ˜160 days to reach the central Scotian Shelf; and ˜220 days to reach the eastern Gulf of Maine. Within the Gulf of St. Lawrence, an increase in the SLR discharge results in a stronger Gaspé Current (up to ˜0.1 m s-1 stronger in the wet run than in the dry run) as well as lower salinity in the western part of the gulf. In the winter, the effect of a higher SLR discharge extends along the Scotian Shelf and into the Gulf of Maine, with salinity in both areas lower by ˜0.1 psu in the wet run than in the dry run.

  20. Storm-water hydrograph separation of run off from a mine-tailings impoundment formed by thickened tailings discharge at Kidd Creek, Timmins, Ontario

    NASA Astrophysics Data System (ADS)

    Al, Tom A.; Blowes, David W.

    1996-05-01

    The Kidd Creek CuZn sulphide mine is located near Timmins, Ontario. Mill tailings are thickened and deposited as a thickened slurry in a circular, conical-shaped pile with an area of approximately 1200 ha. Deposition of tailings as a thickened slurry results in a relatively uniform grain-size distribution and hydraulic conductivity, and a thick tension-saturated zone above the water table. The tailings are drained by numerous small, ephemeral stream channels, which have developed in a radial pattern. During storms, water from these streams collects in catchment ponds where it is held before treatment. The contribution of tailings pore water to the run off is of interest because of the potential for discharge of pore water containing high concentrations of Fe(II)-acidity, metals and SO 4 to the stream. Hydraulic head measurements, measurements of water-table elevation and groundwater flow modelling were conducted to determine the mechanisms responsible for tailings pore water entering the surface streams. Chemical hydrograph separation of storm run off in one of these streams, during three rainfall events, using Na and Cl as conservative tracers, indicates that the integrated tailings pore water fraction makes up between less than 1 % and 20% of the total hydrograph. This range is less than the maximum fraction of tailings pore water of 22-65% reported for run off from a conventional tailings deposit. At this site, preferential flow through permeable fractures may be the dominant mechanism causing discharge of tailings pore water to storm run off. Estimates of the mass of Fe(II) that discharges to the surface run off from the pore water range up to 2800 mg s -1 during a moderate intensity, long duration rainfall event. The greatest potential for discharge of significant masses of solutes derived from the pore water exists during long duration rainfall events, when the water table rises to the surface over large areas of the tailings impoundment.

  1. [Mechanism of the organic pollutant degradation in water by hybrid gas-liquid electrical discharge].

    PubMed

    Zhu, Li-nan; Ma, Jun; Yang, Shi-dong

    2007-09-01

    The method of hybrid gas-liquid electrical discharge was investigated for the removal of phenol. The results indicate that this new method can remove phenol in water effectively. The removal rate increases with increasing voltage and air aeration. The production quantity of H2O2 and O3 is measured respectively in the discharge region and the production quantity increases with increasing of voltage and air aeration. The energy consumption analysis indicates that with increasing the voltage, the increase extent of the phenol removal rate is smaller than the energy's, so the increase of energy efficiency is very small. Air aeration increases the energy consumption. At the same time, a considerable part of energy in the overall input energy makes the temperature of the solution increase, and more energy is transformed into heat, which leads to the waste of energy. PMID:17990549

  2. Continuous measurements of water surface height and width along a 6.5km river reach for discharge algorithm development

    NASA Astrophysics Data System (ADS)

    Tuozzolo, S.; Durand, M. T.; Pavelsky, T.; Pentecost, J.

    2015-12-01

    The upcoming Surface Water and Ocean Topography (SWOT) satellite will provide measurements of river width and water surface elevation and slope along continuous swaths of world rivers. Understanding water surface slope and width dynamics in river reaches is important for both developing and validating discharge algorithms to be used on future SWOT data. We collected water surface elevation and river width data along a 6.5km stretch of the Olentangy River in Columbus, Ohio from October to December 2014. Continuous measurements of water surface height were supplemented with periodical river width measurements at twenty sites along the study reach. The water surface slope of the entire reach ranged from during 41.58 cm/km at baseflow to 45.31 cm/km after a storm event. The study reach was also broken into sub-reaches roughly 1km in length to study smaller scale slope dynamics. The furthest upstream sub-reaches are characterized by free-flowing riffle-pool sequences, while the furthest downstream sub-reaches were directly affected by two low-head dams. In the sub-reaches immediately upstream of each dam, baseflow slope is as low as 2 cm/km, while the furthest upstream free-flowing sub-reach has a baseflow slope of 100 cm/km. During high flow events the backwater effect of the dams was observed to propagate upstream: sub-reaches impounded by the dams had increased water surface slopes, while free flowing sub-reaches had decreased water surface slopes. During the largest observed flow event, a stage change of 0.40 m affected sub-reach slopes by as much as 30 cm/km. Further analysis will examine height-width relationships within the study reach and relate cross-sectional flow area to river stage. These relationships can be used in conjunction with slope data to estimate discharge using a modified Manning's equation, and are a core component of discharge algorithms being developed for the SWOT mission.

  3. A comparison of thermal infrared to fiber-optic distributed temperature sensing for evaluation of groundwater discharge to surface water

    NASA Astrophysics Data System (ADS)

    Hare, Danielle K.; Briggs, Martin A.; Rosenberry, Donald O.; Boutt, David F.; Lane, John W.

    2015-11-01

    Groundwater has a predictable thermal signature that can be used to locate discrete zones of discharge to surface water. As climate warms, surface water with strong groundwater influence will provide habitat stability and refuge for thermally stressed aquatic species, and is therefore critical to locate and protect. Alternatively, these discrete seepage locations may serve as potential point sources of contaminants from polluted aquifers. This study compares two increasingly common heat tracing methods to locate discrete groundwater discharge: direct-contact measurements made with fiber-optic distributed temperature sensing (FO-DTS) and remote sensing measurements collected with thermal infrared (TIR) cameras. FO-DTS is used to make high spatial resolution (typically m) thermal measurements through time within the water column using temperature-sensitive cables. The spatial-temporal data can be analyzed with statistical measures to reveal zones of groundwater influence, however, the personnel requirements, time to install, and time to georeference the cables can be burdensome, and the control units need constant calibration. In contrast, TIR data collection, either from handheld, airborne, or satellite platforms, can quickly capture point-in-time evaluations of groundwater seepage zones across large scales. However the remote nature of TIR measurements means they can be adversely influenced by a number of environmental and physical factors, and the measurements are limited to the surface "skin" temperature of water features. We present case studies from a range of lentic to lotic aquatic systems to identify capabilities and limitations of both technologies and highlight situations in which one or the other might be a better instrument choice for locating groundwater discharge. FO-DTS performs well in all systems across seasons, but data collection was limited spatially by practical considerations of cable installation. TIR is found to consistently locate

  4. Ferroelectric polymer networks with high energy density and improved discharged efficiency for dielectric energy storage.

    PubMed

    Khanchaitit, Paisan; Han, Kuo; Gadinski, Matthew R; Li, Qi; Wang, Qing

    2013-01-01

    Ferroelectric polymers are being actively explored as dielectric materials for electrical energy storage applications. However, their high dielectric constants and outstanding energy densities are accompanied by large dielectric loss due to ferroelectric hysteresis and electrical conduction, resulting in poor charge-discharge efficiencies under high electric fields. To address this long-standing problem, here we report the ferroelectric polymer networks exhibiting significantly reduced dielectric loss, superior polarization and greatly improved breakdown strength and reliability, while maintaining their fast discharge capability at a rate of microseconds. These concurrent improvements lead to unprecedented charge-discharge efficiencies and large values of the discharged energy density and also enable the operation of the ferroelectric polymers at elevated temperatures, which clearly outperforms the melt-extruded ferroelectric polymer films that represents the state of the art in dielectric polymers. The simplicity and scalability of the described method further suggest their potential for high energy density capacitors. PMID:24276519

  5. Effects of water vapor on flue gas conditioning in the electric fields with corona discharge.

    PubMed

    Liqiang, Qi; Yajuan, Zhang

    2013-07-15

    Sulfur dioxide (SO2) removal via pulsed discharge nonthermal plasma in the absence of ammonia was investigated to determine how electrostatic precipitators (ESPs) can effectively collect particulate matter less than 2.5μm in diameter from flue gas. SO2 removal increased as water vapor concentration increased. In a wet-type plasma reactor, directing a gas-phase discharge plasma toward the water film surface significantly enhanced the liquid-phase oxidation of HSO3(-) to SO4(2-). Comparisons of various absorbents revealed that the hydroxyl radical is a key factor in plasma-induced liquid-phase reactions. The resistivity, size distribution, and cohesive force of fly ash at different water vapor contents were measured using a Bahco centrifuge, which is a dust electrical resistivity test instrument, as well as a cohesive force test apparatus developed by the researchers. When water vapor content increased by 5%, fly ash resistivity in flue gas decreased by approximately two orders of magnitude, adhesive force and size increased, and specific surface area decreased. Therefore, ESP efficiency increased. PMID:23669785

  6. Does zero-water discharged technology enhance culture performance of pacific white shrimp (Litopenaeus vannamei Boone.)?

    NASA Astrophysics Data System (ADS)

    Suantika, Gede; Anggraeni, Jayanty; Hasby, Fahri Azhari; Yanuwiarti, Ni Putu Indah

    2014-03-01

    Litopenaeus vannamei or white leg shrimp is an introduced shrimp which has successfully cultured in Indonesia. In Indonesia, L. vannamei is commonly cultured on outdoor/earthen pond that requires renewal of water, less control in term of water quality and disease and attributed to unpredictable yield production. Based on the existing culture condition, a system that enable to minimize water consumption, improve the hygiene of the culture and at the same time maintain a more stable yield production is urgent to be developed by using a zero water discharge system. The system consists of: (a) culture tank - to retain and culture the shrimp; (b) CaCO3 grained - buffering agent and substrate of nitrifying bacteria; (c) aeration line - to provide O2 and homogenize the culture; (d) ancho (feeding) - to control an appropriate feed; (e) nitrifying bacteria adding - to consume ammonium and nitrite then convert it to nitrate, and also control pathogen Vibrio sp.; (f) diatom microalgae (Chaetoceros gracilis) - to uptake nitrate, bacteriostatic agent, feed source, provide O2 and shading. In this study, there were 2 treatments: the static culture (batch) system was set as control (K) (in 70 PL/m2), and culture system with zero-water discharge system which was inoculated by 0.02% v/v 106 CFU/ml of mixed culture nitrifying bacteria and diatom microalgae in 70 PL/m2 (P1). The white leg shrimp used in this experiment was at post larvae (PL) 10 and cultured in a batch system (1 × 1 × 0.5 m3 pond) during 2 months. Several parameters including survival rate, mean body weight, and water quality (salinity, temperature, pH, DO, ammonium, nitrite, and nitrate) were measured. Based on the results, biomass of P1 (237.12 ± 31.11) gram is significantly higher than control (K) (180.80 ± 12.26) gram (P< 0,05). Water quality during the culture period in all treatments were still in tolerance range of white leg shrimp post larvae, except ammonium concentration in control (K) (2.612 ± 0.56) mg

  7. Combining different assays and chemical analysis to characterize the genotoxicity of waters impacted by textile discharges.

    PubMed

    Vacchi, Francine I; Vendemiatti, Josiane A S; Brosselin, Vanessa; Ferreira da Silva, Bianca; B Zanoni, Maria Valnice; DeMeo, Michel; Bony, Sylvie; Devaux, Alain; Umbuzeiro, Gisela A

    2016-08-01

    Waters receiving textile discharges can exhibit genotoxic and mutagenic activity, which has been related to the presence of dyes and aromatic amines as synthesis precursors or byproducts. The aim of this study was to identify dyes and aromatic amines in water samples impacted by textile discharges, and to evaluate the genotoxic responses of these samples using the Salmonella/microsome assay in strains TA98 and YG1041, and the Fpg-modified comet assay in the RTL-W1 fish cell line. The genotoxicity of river samples downstream of the discharge was greater than the upstream samples in both of the Ames tests. The Fpg-modified comet assay detected similar levels of DNA damage in the upstream and downstream samples. Mutagenicity was not detected with TA98, except for the Quilombo River samples, but when YG1041 was used as the tester strain mutagenicity was detected for all sites with a very different profile in upstream sites relative to the other sites. The mutagenic response strongly indicated that aromatic amines or dyes were contributing to the mutagenic activity downstream. The impact of textile discharges was also confirmed by chemical analysis, because the highest concentrations of azo dyes and aromatic amines were detected in the river downstream. This study shows the value of combining assays measuring complementary endpoints to better characterize the mutagenicity of environmental samples, with the advantage that this approach provides an indication of what classes of compounds are responsible for the effect. Environ. Mol. Mutagen. 57:559-571, 2016. © 2016 Wiley Periodicals, Inc. PMID:27412112

  8. High-pressure water facility

    NASA Technical Reports Server (NTRS)

    2006-01-01

    NASA Test Operations Group employees, from left, Todd Pearson, Tim Delcuze and Rodney Wilkinson maintain a water pump in Stennis Space Center's high-pressure water facility. The three were part of a group of employees who rode out Hurricane Katrina at the facility and helped protect NASA's rocket engine test complex.

  9. Periglacial Slope Deposits and Saprolites Controlling Water Discharge. Examples From the Bavarian Forest, Germany and Boulder Creek (CZO), Colorado, USA

    NASA Astrophysics Data System (ADS)

    Huber, J.; Huerkamp, K.; Voelkel, J.; Leopold, M.

    2008-12-01

    Periglacial slope deposits are widespread in Pleistocene non-glaciated areas. They are part of the critical zone, the uppermost layer between surface and the lowest groundwater level and responsible for layer- characteristic soil water movements. These are hydrological processes like interflow and storage, depending on the sediments which are divided into Upper- (Hauptlage), Middle- (Mittellage) and Lower Head (Basislage). Their properties are governed by their genesis at different climates and according to periglacial morphodynamics. Additionally, bedrock geology and sedimentology are influencing factors. In the low mountain ranges of crystalline basement rocks, the bedrock is mostly weathered to saprolite. The significance for lateral and vertical water discharge within the critical zone is not well known and builds a major goal of this study. Especially the transition zone between periglacial slope deposits and saprolite is in the focus of interest. In the study area of the Otterbachtal, Bavarian Forest, Germany, volumetric water content is measured by FD-probes within the different layers. Sedimentological data is collected using refraction seismic prospection and interpolated to the scale of the slope catchment. Physical and chemical soil parameters are determined on samples from profile pits along a representative catena. Therefore, a complete series of water content measurements is available for the last three hydrological years. The results show seasonal typical curves with major fluctuations in water contents occurring in the Upper Head. This is ascribed to good permeabilities and rapid infiltrations within this layer. Permanent high discharge values can be found in the Lower Heads. There is no dependence on the amounts of precipitation visible, thus, they are interpreted as interflow. The saprolite is characterized by approximate constant data, possibly proven by water storage. The transferability of the results to other regions is aspired by comparable

  10. Changes in water clarity in response to river discharges on the Great Barrier Reef continental shelf: 2002-2013

    NASA Astrophysics Data System (ADS)

    Fabricius, K. E.; Logan, M.; Weeks, S. J.; Lewis, S. E.; Brodie, J.

    2016-05-01

    Water clarity is a key factor for the health of marine ecosystems. The Australian Great Barrier Reef (GBR) is located on a continental shelf, with >35 major seasonal rivers discharging into this 344,000 km2 tropical to subtropical ecosystem. This work investigates how river discharges affect water clarity in different zones along and across the GBR. For each day over 11 years (2002-2013) we calculated 'photic depth' as a proxy measure of water clarity (calibrated to be equivalent to Secchi depth), for each 1 km2 pixel from MODIS-Aqua remote sensing data. Long-term and seasonal changes in photic depth were related to the daily discharge volumes of the nearest rivers, after statistically removing the effects of waves and tides on photic depth. The relationships between photic depths and rivers differed across and along the GBR. They typically declined from the coastal to offshore zones, and were strongest in proximity to rivers in agriculturally modified catchments. In most southern inner zones, photic depth declined consistently throughout the 11-year observation period; such long-term trend was not observed offshore nor in the northern regions. Averaged across the GBR, photic depths declined to 47% of local maximum values soon after the onset of river floods, and recovery to 95% of maximum values took on average 6 months (range: 150-260 days). The river effects were strongest at latitude 14.5°-19.0°S, where river loads are high and the continental shelf is narrow. Here, even offshore zones showed a >40% seasonal decline in photic depth, and 17-24% reductions in annual mean photic depth in years with large river nutrients and sediment loads. Our methodology is based on freely available data and tools and may be applied to other shelf systems, providing valuable insights in support of ecosystem management.

  11. Testing of a high performance compressor discharge seal

    NASA Astrophysics Data System (ADS)

    Munson, John H.

    1993-06-01

    A gas lubricated film riding face seal (FRFS) is being developed for use in an advanced subsonic demonstrator engine. This seal will replace the multiple sets of labyrinth seals currently used to seal the compressor discharge air from the engine secondary flow system. The described program consisted of a design, fabrication, and test evaluation phase. This paper deals with testing and results of the rig evaluation of the seals. Several alternative hydrostatic and hydrodynamic FRFS designs were considered in the design phase. Film stiffness, leakage, and heat generation were selected to be the most important design criteria. Using these criteria, hydrodynamic seals proved superior to the hydrostatic designs. Spiral groove design and Rayleigh step pad type seals were selected for detail design and fabrication. Testing was performed in an advanced seal test rig. Both seals were successfully demonstrated. Testing included operation to approximately 700 ft/sec relative velocity, 500 psi pressure differential, and temperatures of at least 1200 F. Noncontacting operation and low leakage rates were demonstrated by both seals.

  12. Industrial discharges of metals in Kigali, Rwanda, and the impact on drinking water quality

    SciTech Connect

    Gasana, J.; Twagilimana, L.; Hallenbeck, W.; Brenniman, G.

    1997-04-01

    Rwanda is a landlocked country located in Africa`s Central-East Great Lakes region. It has a population of 7.5 million which occupies 26,338 km{sup 2}. Its population density (285/km{sup 2}) is one of the highest in the world and has prompted fear of a rapid degradation of the ecosystem. There are no central sewer systems in Rwanda. The use of pit latrines and septic tanks is common in urban and rural areas. People still defecate in the fields. Less than half of the urban population is served by a central water supply. The majority of people get their water untreated from rivers that have been polluted by chemicals and human excreta. In and around the capital city of Kigali, there is a concentration of people, farms, and industries which discharge wastewater into the Nyabarongo River and its tributaries. The Nyabarongo River, a tributary of the Nile, empties into the Akagera River which flows into Lake Victoria. Nyabarongo River water is used for drinking water, cooking, bathing, and agriculture in the Kigali area. There has been very little monitoring of the water quality of the Nyabarongo River and of industrial outfalls located on tributaries of the Nyabarongo River. As a first step in understanding the water quality of the Nyabarongo River, wastewater samples were collected in 1993 from industrial outfalls located on tributaries of the Nyabarongo River. Most of the facilities sampled had no wastewater treatment. The impact of these discharges on the water quality of the Nyabarongo River was evaluated. 1 ref., 2 tabs.

  13. Evaluation of the depth-integration method of measuring water discharge in large rivers

    NASA Astrophysics Data System (ADS)

    Moody, John A.; Troutman, Brent M.

    1992-07-01

    The depth-integration method oor measuring water discharge makes a continuos measurement of the water velocity from the water surface to the bottom at 20 to 40 locations or verticals across a river. It is especially practical for large rivers where river traffic makes it impractical to use boats attached to taglines strung across the river or to use current meters suspended from bridges. This method has the additional advantage over the standard two- and eight-tenths method in that a discharge-weighted suspended-sediment sample can be collected at the same time. When this method is used in large rivers such as the Missouri, Mississippi and Ohio, a microwave navigation system is used to determine the ship's position at each vertical sampling location across the river, and to make accurate velocity corrections to compensate for shift drift. An essential feature is a hydraulic winch that can lower and raise the current meter at a constant transit velocity so that the velocities at all depths are measured for equal lengths of time. Field calibration measurements show that: (1) the mean velocity measured on the upcast (bottom to surface) is within 1% of the standard mean velocity determined by 9-11 point measurements; (2) if the transit velocity is less than 25% of the mean velocity, then average error in the mean velocity is 4% or less. The major source of bias error is a result of mounting the current meter above a sounding weight and sometimes above a suspended-sediment sampling bottle, which prevents measurement of the velocity all the way to the bottom. The measured mean velocity is slightly larger than the true mean velocity. This bias error in the discharge is largest in shallow water (approximately 8% for the Missouri River at Hermann, MO, where the mean depth was 4.3 m) and smallest in deeper water (approximately 3% for the Mississippi River at Vickbsurg, MS, where the mean depth was 14.5 m). The major source of random error in the discharge is the natural

  14. Evaluation of the depth-integration method of measuring water discharge in large rivers

    USGS Publications Warehouse

    Moody, J.A.; Troutman, B.M.

    1992-01-01

    The depth-integration method oor measuring water discharge makes a continuos measurement of the water velocity from the water surface to the bottom at 20 to 40 locations or verticals across a river. It is especially practical for large rivers where river traffic makes it impractical to use boats attached to taglines strung across the river or to use current meters suspended from bridges. This method has the additional advantage over the standard two- and eight-tenths method in that a discharge-weighted suspended-sediment sample can be collected at the same time. When this method is used in large rivers such as the Missouri, Mississippi and Ohio, a microwave navigation system is used to determine the ship's position at each vertical sampling location across the river, and to make accurate velocity corrections to compensate for shift drift. An essential feature is a hydraulic winch that can lower and raise the current meter at a constant transit velocity so that the velocities at all depths are measured for equal lengths of time. Field calibration measurements show that: (1) the mean velocity measured on the upcast (bottom to surface) is within 1% of the standard mean velocity determined by 9-11 point measurements; (2) if the transit velocity is less than 25% of the mean velocity, then average error in the mean velocity is 4% or less. The major source of bias error is a result of mounting the current meter above a sounding weight and sometimes above a suspended-sediment sampling bottle, which prevents measurement of the velocity all the way to the bottom. The measured mean velocity is slightly larger than the true mean velocity. This bias error in the discharge is largest in shallow water (approximately 8% for the Missouri River at Hermann, MO, where the mean depth was 4.3 m) and smallest in deeper water (approximately 3% for the Mississippi River at Vickbsurg, MS, where the mean depth was 14.5 m). The major source of random error in the discharge is the natural

  15. Discharge and water-depth estimates for ungauged rivers: Combining hydrologic, hydraulic, and inverse modeling with stage and water-area measurements from satellites

    NASA Astrophysics Data System (ADS)

    Liu, Ganming; Schwartz, Franklin W.; Tseng, Kuo-Hsin; Shum, C. K.

    2015-08-01

    Anticipating future global freshwater scarcity and providing mitigation require timely knowledge of spatiotemporal dynamics of discharge for gauged and, more challengingly, ungauged rivers. This study describes a coupled hydrologic (SWAT) and hydraulic (XSECT) modeling approach set in a genetic algorithm framework for estimating discharge and water depth for ungauged rivers from space. The method was tested in the Red River of the North basin by comparing simulated discharges and depths from 2006 to 2010 to in situ observations from across the basin. Results showed that calibration using only remotely sensed data (i.e., water levels from ENVISAT altimetry and water extents from LANDSAT) along the main stem of the Red River yielded daily and monthly estimates of river discharge, which correlated to measured discharges at three gaging stations on the main stem with R2 values averaging 0.822 and 0.924, respectively. The comparisons of modeled and measured discharges were also extended to smaller tributaries, yielding a mean R2 of 0.809 over seven gaging stations. The modeling approach also provided estimates of water depth that correlated to observations at four stations with an average R2 of 0.831. We conclude that the integrated modeling approach is able to estimate discharge and water depth from space for larger ungauged rivers. This study also implies that in situ discharge data may not be necessary for successful hydrologic model calibration.

  16. Contribution of snow and glacier melt to discharge for highly glacierised catchments in Norway

    NASA Astrophysics Data System (ADS)

    Engelhardt, M.; Schuler, T. V.; Andreassen, L. M.

    2014-02-01

    Glacierised catchments show a discharge regime that is strongly influenced by snow and glacier meltwaters. In this study, we modelled the mass balance and discharge rates for three highly glacierised catchments (>50% glacier cover) in western Norway over the period 1961-2012. The spatial pattern of the catchments follows a gradient in climate continentality from west to east. The model input were gridded temperature and precipitation values from seNorge (http://senorge.no) which are available at daily resolution. The model accounted for accumulation of snow, transformation of snow to firn and ice, evaporation and melt. Calibration and validation were performed for each catchment based on measurements of seasonal glacier mass balances and daily discharge rates, as additional validation data served daily melt rates from sonic rangers located in the ablation zones of two of the glaciers. The discharge sources snowmelt, glacier melt and rain were analysed with respect to spatial variations and temporal evolution. Model simulations reveal an increase in the relative contribution from glacier melt to total discharge for the three catchments from less than 10% in the early 1990s to 15-30% in the late 2000s. The decline in precipitation by 10-20% in the same period was therefore overcompensated, resulting in an increase in annual discharge by 5-20%. Annual discharge sums and annual glacier melt are most strongly correlated with annual and winter precipitation at the most maritime glacier and, with increased climate continentality, variations in both glacier melt contribution and annual discharge are becoming more strongly correlated with variations in summer temperatures. Therefore, glaciers in more continental climates are especially vulnerable to decrease in both annual and summer discharge with continued rise in summer temperatures and subsequent decrease in glacier extent. This may lead to significant changes to the

  17. Digital-model analysis of the effects of water-use alternatives on spring discharges Gooding and Jerome Counties, Idaho

    USGS Publications Warehouse

    Moreland, Joe A.

    1976-01-01

    Springs discharging from the Snake Plain aquifer contribute approximately 6,000 cubic feet per second (170 cubic metres per second) to flow in the Snake River between Milner and King Hill. Before irrigation began on the Snake River Plain north and east of the springs, total spring discharge was about 4,200 cubic feet per second (120 cubic meters per second). Increasing amounts of irrigated acreage from the early 1900's to the mid-1940's contributed more irrigation-return water to the aquifer resulting in increased discharge at the springs. Maximum discharge of about 6,800 cubic feet per second (190 cubic metres per second) occurred during the late 1940's and early 1950's. Increased use of pumped ground water for irrigation and changing irrigation practices have since resulted in a decline in spring discharge.

  18. 30 CFR 250.248 - What solid and liquid wastes and discharges information and cooling water intake information must...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... information and cooling water intake information must accompany the DPP or DOCD? 250.248 Section 250.248...) § 250.248 What solid and liquid wastes and discharges information and cooling water intake information... cooling water intake information must accompany your DPP or DOCD: (a) Projected wastes. A table...

  19. 30 CFR 250.217 - What solid and liquid wastes and discharges information and cooling water intake information must...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... information and cooling water intake information must accompany the EP? 250.217 Section 250.217 Mineral... cooling water intake information must accompany the EP? The following solid and liquid wastes and discharges information and cooling water intake information must accompany your EP: (a) Projected wastes....

  20. 33 CFR 336.1 - Discharges of dredged or fill material into waters of the U.S.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Discharges of dredged or fill material into waters of the U.S. 336.1 Section 336.1 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FACTORS TO BE CONSIDERED IN THE EVALUATION OF ARMY CORPS OF ENGINEERS DREDGING PROJECTS INVOLVING...

  1. 33 CFR 151.66 - Operating requirements: Discharge of garbage in the Great Lakes and other navigable waters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Operating requirements: Discharge of garbage in the Great Lakes and other navigable waters. 151.66 Section 151.66 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL...

  2. Direct determination of ammoniacal nitrogen in water samples using corona discharge ion mobility spectrometry.

    PubMed

    Jafari, M T; Khayamian, T

    2008-09-15

    In this study, direct determination of ammoniacal nitrogen residues in water samples using corona discharge ion mobility spectrometry (CD-IMS) was investigated. Pyridine was used as an alternate reagent gas to enhance selectivity and sensitivity of the method. The results indicate that the limit of detection (LOD) was about 9.2x10(-3)mugmL(-1) and the linear dynamic range was obtained from 0.03 to 2.00mugmL(-1). The relative standard deviation was about 11%. Furthermore, this method was successfully applied to the direct determination of ammoniacal nitrogen in river and tap water samples and the results were compared with the Nessler method. The comparison of the results validates the potential of the proposed method as an alternative technique for the analysis of the ammoniacal nitrogen in water samples. PMID:18761176

  3. Inactivation of Bacillus subtilis var. niger of both spore and vegetative forms by means of corona discharges applied in water.

    PubMed

    Joubert, Vanessa; Cheype, Cyril; Bonnet, Jean; Packan, Denis; Garnier, Jean-Pierre; Teissié, Justin; Blanckaert, Vincent

    2013-03-01

    Spores are dormant units of bacteria resistant to numerous disinfection methods. Additionally, the effects on bacteria of repetitive electrical discharges in water by used of the so-called "corona discharges" or streamer are poorly described. In this study vegetative and spore forms of Bacillus subtilis var. niger were subjected to these discharges. To generate corona discharges in water, a Marx generator capable of delivering 60-90 kV was used with a coaxial chamber of treatment. Vegetative and spore form reductions were defined using colony-forming unit counting. Proteins extracts were separated by two-dimensional electrophoresis and spots of interest were characterized by mass spectrometry. Shock waves were assessed by the diminution of liposome size and OD(400 nm). The results show a decrease in bacteria viability of 2 log(10) after 1000 discharges on the vegetative form and 4 log(10) after 10,000 discharges on the spores. Two-dimensional electrophoresis showed that the streamers impact the regulation of several proteins in the vegetative forms with UniProt ID: P80861, Q06797, P80244, C0ZI91, respectively. The reduction appears to be due, in part, to hydrogen peroxide (H(2)O(2)) generated by the corona discharges while spore deactivation remained insensitive to these chemicals. The spore eradication was associated to shock waves induced by the discharges but not H(2)O(2). Corona discharges appear as a prospective method for eradication of spores in water. The corona discharges can be an efficient method for decontamination processes of waste water. PMID:23286986

  4. Effects of discharge current and voltage on the high density of metastable helium atoms

    NASA Astrophysics Data System (ADS)

    Feng, Xian-Ping; Andruczyk, D.; James, B. W.; Takiyama, K.; Namba, S.; Oda, T.

    2003-05-01

    Both hollow-cathode and Penning-type discharges were adopted to excite helium atoms to a metastable state. Experimental data indicate that Penning discharge is more suitable for generating high fractions of metastables in a low-density helium beam for laser-induced fluorescence technique in measuring electric fields at the edge of a plasma. The metastable density increases with increasing helium gas pressure in the range of 1.33×10-2-66.7Pa. The highest metastable density of 3.8×1016m-3 is observed at a static gas pressure of 66.7Pa. An approximately linear relationship between the density of metastable helium atoms and the plasma discharge current is observed. Magnetic field plays a very important role in producing a high density of metastable atoms in Penning discharge.

  5. Production of High Energy Ions Near an Ion Thruster Discharge Hollow Cathode

    NASA Technical Reports Server (NTRS)

    Katz, Ira; Mikellides, I. G.; Goebel, D. M.; Jameson, K. K.; Wirz, R.; Polk, James E.

    2006-01-01

    Several researchers have measured ions leaving ion thruster discharge chambers with energies far greater than measured discharge chamber potentials. Presented in this paper is a new mechanism for the generation of high energy ions and a comparison with measured ion spectra. The source of high energy ions has been a puzzle because they not only have energies in excess of measured steady state potentials, but as reported by Goebel et. al. [1], their flux is independent of the amplitude of time dependent plasma fluctuations. The mechanism relies on the charge exchange neutralization of xenon ions accelerated radially into the potential trough in front of the discharge cathode. Previous researchers [2] have identified the importance of charge exchange in this region as a mechanism for protecting discharge cathode surfaces from ion bombardment. This paper is the first to identify how charge exchange in this region can lead to ion energy enhancement.

  6. Spatiotemporal study of the local thermodynamic equilibrium deviations in high-intensity discharge lamps

    SciTech Connect

    Helali, H.; Bchir, T.; Araoud, Z.; Charrada, K.

    2013-04-15

    The aim of this work is to study the local thermodynamic equilibrium (LTE) deviations in arc discharges plasma generated in high-intensity discharge lamps operating under an ac (50 Hz) power supply. To achieve this goal, we elaborate a two-temperature, two-dimensional, and time-depending model. We have found numerical results almost reproducing the experimental data, which allows us to validate this model. After validation, we have discussed different energy term effects on the LTE deviations.

  7. A severe human ESD (electrostatic discharge) model for safety and high reliability system qualification testing

    SciTech Connect

    Fisher, R J

    1989-01-01

    A severe human electrostatic discharge (ESD) equivalent source model has been developed for use in qualification testing of systems that have stringent safety or very high reliability requirements. The model produces the now-acknowledged worst-case waveform, and the values of the constituent components have been selected from measured human body electrical parameters to maximize the peak amplitude and rate of rise of the short-circuit discharge current and energy transfer to the victim system. 18 refs., 5 figs.

  8. An evaluation of dilution models for the discharge of produced water into the Gulf of Mexico

    SciTech Connect

    Tomasko, D.

    1993-11-01

    A study was performed to determine which of two mixing models (CORMIX1 or UM/PLUMES) was more appropriate for simulating the vertically downward discharge of negatively buoyant produced waters into a stratified ambient having a crossflow in Gulf of Mexico waters. For deep waters without impingement on the seafloor or gravitational collapse of the plume, UM/PLUMES is recommended because of its Lagrangian solution to the governing equations of mass, momentum, and energy. CORMIXI is recommended if the plume interacts with the seafloor or if the plume undergoes gravitational collapse, although its results may be overly conservative at the edge of the mixing zone. These overly conservative results can be corrected by employing a post-processing technique developed by Limno-Tech, Inc. and Wright. Because neither model was specifically designed to simulate the entire discharge scenario, additional work is recommended. This work includes laboratory and field studies to generate additional validation data, and code modifications to enhance the capabilities of the models and reduce uncertainty in the predicted jet behavior and potential errors in post processing model results.

  9. Does localized recharge occur at a discharge area within the ground-water flow system of Yucca Mountain, Nevada?

    SciTech Connect

    Czarnecki, J.B.; Kroitoru, L.; Ronen, D. |; Magaritz, M.

    1992-10-01

    Studies done in 1984, at a central site on Franklin Lake playa (also known as Alkali Flat, a major discharge area of the ground-water flow system that includes Yucca Mountain, Nevada, the potential site of a high-level nuclear-waste repository) yield limited hydraulic-head and hydrochemical data from a 3-piezometer nest which indicated a slightly downward hydraulic gradient ({minus}0.02) and decreasing concentration of dissolved solids with increasing depth. Hydraulic-head measurements in June, 1989 made at the piezometer nest showed a substantially larger downward gradient ({minus}0.10) and a 0. 83{minus}meter higher water level in the shallowest piezometer (3.29 meters deep), indicating the possibility of localized recharge. during the period of September-November, 1989, a multilevel sampler was used to obtain detailed hydrochemical profiles of the uppermost 1. 5 m of the saturated zone.

  10. Experimental observation of the luminescence flash at the collapse phase of a bubble produced by pulsed discharge in water

    SciTech Connect

    Huang, Yifan; Zhang, Liancheng; Zhu, Xinlei; Liu, Zhen Yan, Keping; Chen, Jim

    2015-11-02

    This letter presents an experimental observation of luminescence flash at the collapse phase of an oscillating bubble produced by a pulsed discharge in water. According to the high speed records, the flash lasts around tens of microseconds, which is much longer than the lifetime of laser and ultrasound induced luminescence flashes in nanoseconds and picoseconds, respectively. The pulse width of temperature waveform and minimum radius calculated at the collapse phase also show that the thermodynamic and dynamic signatures of the bubbles in this work are much larger than those of ultrasound and laser induced bubbles both in time and space scales. However, the peak temperature at the point of collapse is close to the results of ultrasound and laser induced bubbles. This result provides another possibility for accurate emission spectrum measurement other than amplification of the emitted light, such as increasing laser energy or sound energy or substituting water with sulphuric acid.

  11. Experimental observation of the luminescence flash at the collapse phase of a bubble produced by pulsed discharge in water

    NASA Astrophysics Data System (ADS)

    Huang, Yifan; Zhang, Liancheng; Chen, Jim; Zhu, Xinlei; Liu, Zhen; Yan, Keping

    2015-11-01

    This letter presents an experimental observation of luminescence flash at the collapse phase of an oscillating bubble produced by a pulsed discharge in water. According to the high speed records, the flash lasts around tens of microseconds, which is much longer than the lifetime of laser and ultrasound induced luminescence flashes in nanoseconds and picoseconds, respectively. The pulse width of temperature waveform and minimum radius calculated at the collapse phase also show that the thermodynamic and dynamic signatures of the bubbles in this work are much larger than those of ultrasound and laser induced bubbles both in time and space scales. However, the peak temperature at the point of collapse is close to the results of ultrasound and laser induced bubbles. This result provides another possibility for accurate emission spectrum measurement other than amplification of the emitted light, such as increasing laser energy or sound energy or substituting water with sulphuric acid.

  12. Predicted impacts from offshore produced water discharges on hypoxia in the Gulf of Mexico.

    SciTech Connect

    Bierman, V. J.; Hinz, S.C.; Justic, D.; Scavia, D.; Veil, J. A.; Satterlee, K.; Parker, M. E.; Wilson, S.; Environmental Science Division; LimnoTech.; Louisiana State Univ.; Univ of Michigan; Shell E&P Co.; Exxon Mobil Production Co.; U.S. EPA

    2008-06-01

    Summer hypoxia (dissolved oxygen < 2 mg/L) in the bottom waters of the northern Gulf of Mexico has received considerable scientific and policy attention because of potential ecological and economic impacts. This hypoxic zone forms off the Louisiana coast each summer and has increased from an average of 8,300 km{sup 2} in 1985-1992 to over 16,000 km{sup 2} in 1993-2001, reaching a record 22,000 km{sup 2} in 2002. The almost threefold increase in nitrogen load from the Mississippi River Basin (MRB) to the Gulf since the middle of the last century is the primary external driver for hypoxia. A goal of the 2001 Federal Action Plan is to reduce the 5-year running average size of the hypoxic zone to below 5,000 km{sup 2} by 2015. After the Action Plan was developed, a new question arose as to whether sources other than the MRB may also contribute significant quantities of oxygen-demanding substances. One very visible potential source is the hundreds of offshore oil and gas platforms located within or near the hypoxic zone, many of which discharge varying volumes of produced water. The objectives of this study were to assess the incremental impacts of produced water discharges on dissolved oxygen in the northern Gulf of Mexico, and to evaluate the significance of these discharges relative to loadings from the MRB. Predictive simulations were conducted with three existing models of Gulf hypoxia using produced water loads from an industry study. Scenarios were designed that addressed loading uncertainties, settleability of suspended constituents, and different assumptions on delivery locations for the produced water loads. Model results correspond to the incremental impacts of produced water loads, relative to the original model results, which included only loads from the MRB. The predicted incremental impacts of produced water loads on dissolved oxygen in the northern Gulf of Mexico from all three models were small. Even considering the predicted ranges between lower- and

  13. Novel industrial wastewater treatment integrated with recovery of water and salt under a zero liquid discharge concept.

    PubMed

    Rajamani, Sengodagounder

    2016-03-01

    Conventional industrial effluent treatment systems are designed to reduce biochemical oxygen demand (BOD), chemical oxygen demand (COD) but not total dissolved solids (TDS), mainly contributed by chlorides. In addition to the removal of TDS, it is necessary to recover water for reuse to meet the challenges of shortage of quality water. To recover water, the wastewater needs to be further treated by adopting treatment systems including microfilters, low pressure membrane units such as ultrafiltration (UF), membrane bioreactors (MBR), etc., for the application of reverse osmosis (RO) systems. By adopting the RO system, 75%-80% of quality water with <500 mg/L of TDS is recovered from treated effluent. The management of 20%-25% of the saline water rejected from the RO system with high TDS concentration is being addressed by methods such as forced evaporation systems. The recovery of water from domestic and industrial waste for reuse has become a reality. The membrane system has been used for different applications. It has become mandatory to achieve zero liquid discharge (ZLD) in many states in India and other countries such as Spain, China, etc., and resulted in development of new treatment technologies to suit the local conditions. PMID:26982606

  14. Purification of water by bipolar pulsed discharge plasma combined with TiO2 catalysis

    NASA Astrophysics Data System (ADS)

    Zhang, Yongrui; Zhang, Ruobing; Ma, Wenchang; Zhang, Xian; Wang, Liming; Guan, Zhicheng

    2013-03-01

    In the process of water treatment by bipolar pulsed discharge plasma, there are not only the chemical effects such as the cold plasma, but also the physical effects such as the optical radiation. The energy of the optical radiation can be used by photocatalyst. Therefore, the effect of the photocatalyst to the degradation of the organic pollutant was investigated using a packed bed reactor by bipolar pulsed discharge in the air-liquid-solid mixture. The nanoparticle TiO2 photocatalyst was obtained using the sol-gel method and the typical dye solution Indigo Carmine was chosen as the degradation target to test the catalytic effect of the nanoparticle TiO2 photocatalyst. Experiment results proved that the degradation efficiency of the Indigo Carmine solution was increased by a certain extent with the TiO2 photocatalyst. It was totally decolorized within 3 minutes by bipolar pulsed discharge in the condition that the peak voltage was 30 kV and the air flow was 1.0 m3 h-1.

  15. Relationship of water quality of Hudson River, New York, during peak discharges to geologic characteristics of contributing subbasins

    USGS Publications Warehouse

    Turk, John T.; Troutman, David E.

    1981-01-01

    Water samples from two Hudson River floods in 1977--one originating mainly in shale subbasins that produce high sediment loads, the other in soil-poor, crystalline rock terrane that yields little sediment--were analyzed to evaluate the relationship of iron, manganese, lead, phosphorus, and polychlorinated biphenyls (PCB's) to suspended-sediment concentration. During the flood of high sediment discharge, ratios for all substances studied except PCB 's reflected their concentration within the basin regolith. During the flood of smaller magnitude, from the low-sediment crystalline terrane, however, only the ratio for iron correlated with predicted concentrations in the basin, which suggests that the chemical constituents studied were contributed principally from other sources, possibly anthropogenic sources. High lead concentrations in the low-sediment flood were derived from an unidentified, basinwide source whose contribution was relatively insignificant during the flood from the shale area. (USGS)

  16. Mechanisms of deflagration-to-detonation transition under initiation by high-voltage nanosecond discharges

    SciTech Connect

    Rakitin, Aleksandr E.; Starikovskii, Andrei Yu.

    2008-10-15

    An experimental study of detonation initiation in a stoichiometric propane-oxygen mixture by a high-voltage nanosecond gas discharge was performed in a detonation tube with a single-cell discharge chamber. The discharge study performed in this geometry showed that three modes of discharge development were realized under the experimental conditions: a spark mode with high-temperature channel formation, a streamer mode with nonuniform gas excitation, and a transient mode. Under spark and transient initiation, simultaneous ignition inside the discharge channel occurred, forming a shock wave and leading to a conventional deflagration-to-detonation transition (DDT) via an adiabatic explosion. The DDT length and time at 1 bar of initial pressure in the square smooth tube with a 20-mm transverse size amounted to 50 mm and 50{mu}s, respectively. The streamer mode of discharge development at an initial pressure of 1 bar resulted in nonuniform mixture excitation and a successful DDT via a gradient mechanism, which was confirmed by high-speed time resolved ICCD imaging. The gradient mechanism implied a longer DDT time of 150{mu}s, a DDT run-up distance of 50 mm, and an initiation energy of 1 J, which is two orders of magnitude less than the direct initiation energy for a planar detonation under these conditions. (author)

  17. Nanofiltration of Mine Water: Impact of Feed pH and Membrane Charge on Resource Recovery and Water Discharge.

    PubMed

    Mullett, Mark; Fornarelli, Roberta; Ralph, David

    2014-01-01

    Two nanofiltration membranes, a Dow NF 270 polyamide thin film and a TriSep TS 80 polyamide thin film, were investigated for their retention of ionic species when filtering mine influenced water streams at a range of acidic pH values. The functional iso-electric point of the membranes, characterized by changes in retention over a small pH range, were examined by filtering solutions of sodium sulphate. Both membranes showed changes in retention at pH 3, suggesting a zero net charge on the membranes at this pH. Copper mine drainage and synthetic solutions of mine influenced water were filtered using the same membranes. These solutions were characterized by pH values within 2 and 5, thus crossing the iso-electric point of both membranes. Retention of cations was maximized when the feed solution pH was less than the iso-electric point of the membrane. In these conditions, the membrane has a net positive charge, reducing the transmission rate of cations. From the recoveries of a range of cations, the suitability of nanofiltration was discussed relative to the compliance with mine water discharge criteria and the recovery of valuable commodity metals. The nanofiltration process was demonstrated to offer advantages in metal recovery from mine waste streams, concomitantly enabling discharge criteria for the filtrate disposal to be met. PMID:24957170

  18. Nanofiltration of Mine Water: Impact of Feed pH and Membrane Charge on Resource Recovery and Water Discharge

    PubMed Central

    Mullett, Mark; Fornarelli, Roberta; Ralph, David

    2014-01-01

    Two nanofiltration membranes, a Dow NF 270 polyamide thin film and a TriSep TS 80 polyamide thin film, were investigated for their retention of ionic species when filtering mine influenced water streams at a range of acidic pH values. The functional iso-electric point of the membranes, characterized by changes in retention over a small pH range, were examined by filtering solutions of sodium sulphate. Both membranes showed changes in retention at pH 3, suggesting a zero net charge on the membranes at this pH. Copper mine drainage and synthetic solutions of mine influenced water were filtered using the same membranes. These solutions were characterized by pH values within 2 and 5, thus crossing the iso-electric point of both membranes. Retention of cations was maximized when the feed solution pH was less than the iso-electric point of the membrane. In these conditions, the membrane has a net positive charge, reducing the transmission rate of cations. From the recoveries of a range of cations, the suitability of nanofiltration was discussed relative to the compliance with mine water discharge criteria and the recovery of valuable commodity metals. The nanofiltration process was demonstrated to offer advantages in metal recovery from mine waste streams, concomitantly enabling discharge criteria for the filtrate disposal to be met. PMID:24957170

  19. Partitioning of Water Discharge by Distributary Channels in the Prograding, Wax Lake Delta, Coastal Louisiana, USA

    NASA Astrophysics Data System (ADS)

    Buttles, J.; Mohrig, D.; Nittrouer, J.; McElroy, B.; Baitis, E.; Allison, M.; Paola, C.; Parker, G.; Kim, W.

    2007-12-01

    How water and sediment is routed through distributary networks on river deltas is incompletely known and a topic of much active research. We have undertaken a study to determine the controls on partitioning of water and sediment discharge in distributary channels of the Wax Lake Delta and to connect these transport processes to the land building associated with the growth of islands that separate distributary channels from each other. Here we present first results from the field project that defines how water from the upstream primary channel is partitioned between the first set of five distributary channels. Measurements of water discharge and channel bathymetry were collected using a 22-ft research vessel equipped with an acoustic Doppler velocity profiler, a swath bathymetry profiler and dual differential GPS antennas. Wax Lake Delta is situated at the downstream end of Wax Lake Outlet, a man-made channel that diverts water and sediment from the lower Atchafalaya River, roughly 20 km upstream from Morgan City, LA. The subaerial delta has been building out into Atchafalaya Bay since roughly 1973 with a delta-front advance rate of about 0.27 km/yr. Associated with this growth has been development of a distributary network of channels that continues to evolve as the delta progrades seaward. Measurements collected in May, 2007 define properties of the upstream channel and the first set of five distributary channels. Characteristic width, depth and water discharge for the upstream channel are 420 m, 21.2 m, and 2900 m3/s. Characteristic values for width, depth and water discharge for the five distributary channels are 1) 270 m, 6.7 m, and 310 m3/s, 2) 300 m, 6.5 m, and 350 m3/s, 3) 650 m, 6.8 m, and 820 m3/s, 4) 395 m, 6.5 m, and 560 m3/s, and 5) 440 m, 6.0 m, and 440 m3/s. These data highlight a number of interesting points regarding the initial set of bifurcations. First, the transition from one to five channels is associated with a two-thirds reduction in

  20. Automated reconstruction of drainage basins and water discharge to the sea through glacial cycles

    NASA Astrophysics Data System (ADS)

    Wickert, Andrew

    2015-04-01

    Over glacial cycles, ice masses and their geophysical impacts on surface topography dramatically changed drainage patterns and river discharges. These changes impacted meltwater discharge to the ocean, geomorphology, and climate. As the river systems'the threads that tied the ice sheets to the sea'were stretched, severed, and rearranged during deglaciation, they also shrank and swelled with the pulse of meltwater inputs and proglacial lake dynamics. Here I present a general method to compute past river flow paths, drainage basin geometries, and river discharges. I automate these calculations within GRASS GIS to take advantage of rapid solution techniques for drainage networks in an open-source and compute-cluster-ready environment. I combine modern topography and bathymetry with ice sheet reconstructions from the last glacial cycle and a global glacial isostatic adjustment model to build digital elevation models of the past Earth surface. I then sum ice sheet mass balance with computed precipitation and evapotranspiration from a paleoclimate general circulation model to produce grids of water input. I combine these topographic and hydrologic inputs to compute past river networks and discharges through time. These paleodrainage reconstructions connect ice sheets, sea level, and climate models to fluvial systems, which in turn generate measurable terrace and sedimentary records as they carry physical, compositional, and isotopic signatures of ice sheet melt and landscape change through their channels and to the sea. Therefore, this work provides a self-consistent paleogeographic framework within which models and geologic records may be quantitatively compared to build new insights into past glacial systems.

  1. Locating Ground-Water Discharge in the Hanford Reach of the Columbia River

    SciTech Connect

    Lee, D.R.; Geist, D.R.; Saldi, K.; Hartwig, D.; Cooper, T.

    1997-03-01

    A bottom-contacting probe for measuring electrical conductivity at the sediment-water interface was used to scan the bed of the Columbia River adjacent to the Hanford Site in southeast Washington State during a 10-day investigation. Four river-sections, each about a kilometer in length, were scanned for variations in electrical conductivity. The probe was towed along the riverbed at a speed of 1 m/s and is position was recorded using a Global Positioning System. The bottom tows revealed several areas of elevated electrical conductivity. Where these anomalies were relatively easy to access, piezometers were driven into the riverbed and porewater electrical conductivity ranged from 111 to 150 uS/cm. The piezometers, placed in electrical conductivity “hotspots,” yielded chemical or isotopic data consistent with previous analyses of water taken from monitoring wells and visible shoreline seeps. Tritium, nitrate, and chromium exceeded water quality standards in some porewaters. The highest tritium and nitrate levels were found near the Old Hanford Townsite at 120,000 pCi/L (+ 5,880 pCi/L total propagated analytical uncertainty) and ug/L (+ 5,880 ug/L), respectively. The maximum chromium (total and hexavalent) levels were found near 100-H reactor area where unfiltered porewater total chromium was 1,900 ug/L (+ 798 ug/L) and hexavalent chromium was 20 ug/L. The electrical conductivity probe provided rapid, cost-effective reconnaissance for ground-water discharge areas when used in combination with conventional piezometers. It may be possible to obtain quantitative estimates of both natural and contaminated ground-water discharge in the Hanford Reach with more extensive surveys of river bottom.

  2. Temporal evolution of the electron density produced by nanosecond repetitively pulsed discharges in water vapor at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Sainct, Florent; Lacoste, Deanna; Kirkpatrick, Michael; Odic, Emmanuel; Laux, Christophe

    2014-10-01

    A study of plasma discharges produced by nanosecond repetitive pulses (NRP) in water vapor at 450 K and 1 atm is presented. The plasma was generated between two point electrodes with 20-ns duration, high-voltage (0--20 kV) pulses, at a repetition frequency of 10 kHz, in the spark regime (2 mJ/pulse). Atomic lines measured by optical emission spectroscopy were used to determine the electron number density in this non-equilibrium water-vapor plasma. The broadenings and shifts of the Hα and Hβ lines of the hydrogen Balmer series and of the atomic oxygen triplet at 777 nm were analyzed. For a maximum reduced electric field of about 200 Td, a maximum electron density of 2 × 1018 cm-3 was measured, corresponding to an ionization level of about 10 %. This ionization level is two orders of magnitude higher than the one obtained for similar NRP discharges in air at atmospheric pressure.

  3. Impact of discharges from point and nonpoint sources on water quality of the upper Reedy River near Greenville, South Carolina

    USGS Publications Warehouse

    Cahal, D.I.; Speiran, G.K.

    1983-01-01

    Impacts of discharge from nonpoint sources in the urban area of Greenville, South Carolina and from the point source, the Mauldin Road Wastewater Treatment Plant, on water quality of the Reedy River were studied from October 1979 through September 1980. Streamflow and water-quality data were collected before and during two storms. The pH and concentrations of organic nitrogen, ammonium, nitrate plus nitrate, ultimate carbonaceous biochemical oxygen demand, dissolved oxygen, and orthophosphate were determined. Streamflow and concentrations of dissolved oxygen were measured continuously at three stations from May through September 1980. Discharge from the point source resulted in average daily concentrations of dissolved oxygen less than 5 milligrams per liter in the Reedy River on 34 days during low streamflow in the summer of 1980. During periods of high streamflow that resulted from the two storms. Dissolved oxygen remained at about 5 milligrams per liter in the Reedy River because increased dilution of loads of oxygen-demanding materials reduced the impacts of these loads on the quality of the Reedy River. (USGS)

  4. Ultra high energy density and fast discharge nanocomposite capacitors

    NASA Astrophysics Data System (ADS)

    Tang, Haixiong; Sodano, Henry A.

    2013-04-01

    Nanocomposites containing high dielectric permittivity ceramics embedded in high breakdown strength polymers are currently of considerable interest as a solution for the development of high energy density capacitors. However, the improvement of dielectric permittivity comes at expense of the breakdown strength leading to limit the final energy density. Here, an ultra-high energy density nanocomposite was fabricated based on high aspect ratio barium strontium titanate nanowires. The pyroelectric phase Ba0.2Sr0.8TiO3 was chosen for the nanowires combined with quenched PVDF to fabricate high energy density nanocomposite. The energy density with 7.5% Ba0.2Sr0.8TiO3 nanowires reached 14.86 J/cc at 450 MV/m, which represented a 42.9% increase in comparison to the PVDF with an energy density of 10.4 J/cc at the same electric field. The capacitors have 1138% greater than higher energy density than commercial biaxial oriented polypropylene capacitors (1.2 J/cc at 640). These results demonstrate that the high aspect ratio nanowires can be used to produce nanocomposite capacitors with greater performance than the neat polymers thus providing a novel process for the development of future pulsed-power capacitors.

  5. Comparison of two high-repetition-rate pulsed CO/sub 2/ laser discharge geometries

    SciTech Connect

    Faszer, W.; Tulip, J.; Seguin, H.

    1980-11-01

    Two discharge geometries are commonly used for pumping high-repetition-rate transversely excited atmosphere (TEA) lasers. One uses solid electrodes with preionization provided by downstream spark pins. The other uses a solid electrode and a screen electrode with preionization provided by an auxiliary discharge behind the screen. In this study the performance of the two systems was compared. The repetition rate at which arcing occurs was found to increase linearly with flow velocity but decrease with increasing energy density. It was also dependent on system geometry and the spark pin preionized system performed better than the auxiliary discharge preionized system. Data are given for discharges in N/sub 2/, CO/sub 2/, He, and a CO/sub 2/ laser mixture.

  6. Impact of high rate discharge on the aging of lithium nickel cobalt aluminum oxide batteries

    NASA Astrophysics Data System (ADS)

    Wong, Derek; Shrestha, Biju; Wetz, David A.; Heinzel, John M.

    2015-04-01

    In this study, three identical LiNixCoyAl1-x-yO2, (NCA) batteries are evaluated to understand the impact of high rate discharge on the rate of capacity fade. The first of the three cells is repeatedly discharged in a pulse width modulated (PWM) manner at a frequency of 10 kHz, duty cycle of 50%, and peak rate of 83C (250 A). The second cell is repeatedly discharged at a constant current (CC) rate of 25C (75 A) while the third cell, which serves as the control cell, is discharged at its nominal CC rate of 1C (3 A). All three cells are recharged using a 1C CC recharge procedure to minimize the impact of recharge on cell aging. Novel and commercially procured battery cyclers are used to experimentally discharge and recharge the cells. Periodic baseline measurements, in which both capacity and electrochemical impedance spectroscopy (EIS) measurements show that the degradation mechanisms are enhanced under high rate pulse discharge cycling conditions. EIS modeling points to breakdown in the integrity of the anodic side double layer and increased charge transfer resistance as the largest contributors to impedance evolution in the cell.

  7. Estimating reach-averaged discharge for the River Severn from measurements of river water surface elevation and slope

    NASA Astrophysics Data System (ADS)

    Durand, Michael; Neal, Jeffrey; Rodríguez, Ernesto; Andreadis, Konstantinos M.; Smith, Laurence C.; Yoon, Yeosang

    2014-04-01

    An algorithm is presented that calculates a best estimate of river bathymetry, roughness coefficient, and discharge based on input measurements of river water surface elevation (h) and slope (S) using the Metropolis algorithm in a Bayesian Markov Chain Monte Carlo scheme, providing an inverse solution to the diffusive approximation to the shallow water equations. This algorithm has potential application to river h and S measurements from the forthcoming Surface Water and Ocean Topography (SWOT) satellite mission. The algorithm was tested using in situ data as a proxy for satellite measurements along a 22.4 km reach of the River Severn, UK. First, the algorithm was run with gage measurements of h and S during a small, in-bank event in June 2007. Second, the algorithm was run with measurements of h and S estimated from four remote sensing images during a major out-of-bank flood event in July 2007. River width was assumed to be known for both events. Algorithm-derived estimates of river bathymetry were validated using in situ measurements, and estimates of roughness coefficient were compared to those used in an operational hydraulic model. Algorithm-derived estimates of river discharge were evaluated using gaged discharge. For the in-bank event, when lateral inflows from smaller tributaries were assumed to be known, the method provided an accurate discharge estimate (10% RMSE). When lateral inflows were assumed unknown, discharge RMSE increased to 36%. Finally, if just one of the three river reaches was assumed to be have known bathymetry, solutions for bathymetry, roughness and discharge for all three reaches were accurately retrieved, with a corresponding discharge RMSE of 15.6%. For the out-of-bank flood event, the lateral inflows were unknown, and the final discharge RMSE was 19%. These results suggest that it should be possible to estimate river discharge via SWOT observations of river water surface elevation, slope and width.

  8. Seasonal Variation of Frequency of High Current Lightning Discharges Observed by JLDN

    NASA Astrophysics Data System (ADS)

    Saito, Mikihisa; Ishii, Masaru; Fujii, Fumiyuki; Matsui, Michihiro

    Seasonal variations of number of high current lightning discharges exceeding 100kA observed by JLDN (Japanese Lightning Detection Network) were analyzed. The months with averaged altitudes of -10°C level higher than 5.7km are classified as ordinary summer from the viewpoint of lightning activity. Meanwhile, on the coast of the Sea of Japan, more than 90% of negative high current lightning discharges were -GC (Ground to Cloud) strokes in the months when monthly averaged altitudes of -10°C level are lower than 2.7km. These months are classified as the winter lightning season when upward lightning flashes frequently occur. Months other than winter or summer are classified as spring or autumn. In these seasons, the proportions of positive high current lightning discharges are higher than those of negative discharges like winter. Thus, the charge structure in the thunderclouds of spring and autumn may be similar to that in winter, and high current lightning strokes tend to occur. Since this variation of seasons is different in each area of Japan, relation of seasons, areas, and densities of high current lightning discharges were analyzed.

  9. Transport and transformation of pharmaceuticals and other contaminants of emerging concern from wastewater discharge through surface water to drinking water intake and treatment

    EPA Science Inventory

    The ubiquitous presence of pharmaceuticals, hormones, and other contaminants of emerging concern (CECs) in surface-water resources have necessitated research that better elucidates pathways of transport and transformation for these compounds from their discharged wastewater, thro...

  10. Streamflow, ground-water recharge and discharge, and characteristics of surficial deposits in Buzzards Bay basin, southeastern Massachusetts

    USGS Publications Warehouse

    Bent, Gardner C.

    1995-01-01

    Streamflows exceeded between 50 and 99 percent of the time during water years 1967-91 were estimated for 14 low-flow partial-record stations and two discontinued streamflow-gaging stations in Buzzards Bay Basin, Massachusetts. At low flows, stream discharge per unit area for subbasins underlain primarily by stratified-drift deposits was several times greater than for subbasins underlain primarily by till and bedrock deposits. Streamflow measured three times at the Paskamanset River showed that streamflows downstream of municipal pumping wells were affected by ground-water pumpage near the river. Mean ground-water recharge rates were estimated to be 19.7 to 22.6 and 23.8 to 25.2 inches per year for basins underlain primarily by till and bedrock deposits and stratified drift deposits, respectively. Annual ground-water recharge during drought years can be less than one-half of the mean ground-water recharge rate for water years 1967-91. Ground-water discharge rates generally were estimated to be 1 to 4 inches per year less than ground-water recharge rates. Thus, ground-water discharge rates could be used as a low estimate of ground-water recharge rates. From the 50 to 99 percent flow duration, ground-water discharges averaged 85.7 percent of the total streamflow at six nearby streamflow-gaging stations. Ground-water discharges were estimated at the 16 stations in the basin by multiplying estimated streamflows at the selected flow durations from 50- to 99-percent for water years 1967-91 by 85.7 percent. Based on new well-log and seismic-refraction survey data, a few minor corrections were determined in existing saturated thickness maps for stratified-drift deposits in basin.

  11. Removal of atrazine in water by combination of activated carbon and dielectric barrier discharge.

    PubMed

    Vanraes, Patrick; Willems, Gert; Nikiforov, Anton; Surmont, Pieter; Lynen, Frederic; Vandamme, Jeroen; Van Durme, Jim; Verheust, Yannick P; Van Hulle, Stijn W H; Dumoulin, Ann; Leys, Christophe

    2015-12-15

    Efficiency of modern wastewater treatment plants to remove or decompose persistent contaminants in low concentration is often insufficient to meet the demands imposed by governmental laws. Novel, efficient and cheap methods are required to address this global issue. We developed a new type of plasma reactor, in which atrazine decomposition by atmospheric dielectric barrier discharge (DBD) in dry air is combined with micropollutant adsorption on activated carbon textile and with extra bubbling of generated ozone. Investigation of reaction kinetics and by-product analysis shows that increasing input power with a factor 3.5 leads to deeper atrazine oxidation without significantly changing energy yield of atrazine removal. By-products of first and later generations are detected with HPLC-MS analysis in water and adsorbed on the activated carbon textile. Our reactor is compared in energy efficiency with reactors described in literature, showing that combination of plasma discharge with pollutant adsorption and ozone recycling is attractive for future applications of water treatment. PMID:26282086

  12. Phosphonate removal from discharged circulating cooling water using iron-carbon micro-electrolysis.

    PubMed

    Zhou, Zhen; Qiao, Weimin; Lin, Yangbo; Shen, Xuelian; Hu, Dalong; Zhang, Jianqiao; Jiang, Lu-Man; Wang, Luochun

    2014-01-01

    Phosphonate is a commonly used corrosion and scale inhibitor for a circulating cooling water (CCW) system. Its discharge could cause eutrophication of receiving waters. The iron-carbon (Fe/C) micro-electrolysis technology was used to degrade and remove phosphonate from discharged CCW. The influences of initial pH, Fe/C ratio (FCR) and temperature on phosphonate removal were investigated in a series of batch tests and optimized by response surface methodology. The quadratic model of phosphonate removal was obtained with satisfactory degrees of fitness. The optimum conditions with total phosphorus removal efficiency of 95% were obtained at pH 7.0, FCR of 1.25, and temperature of 45 °C. The phosphonate removal mechanisms were also studied. Phosphonate removal occurred predominantly via two consecutive reactive phases: the degradation of phosphonate complexes (Ca-phosphonate) and the precipitation of Fe/C micro-electrolysis products (PO₄(3-), Ca²⁺ and Fe³⁺). PMID:25098884

  13. Coupled modelling of the effect of overpressure on water discharge in a tile drainage system

    NASA Astrophysics Data System (ADS)

    Henine, H.; Nédélec, Y.; Ribstein, P.

    2014-04-01

    The effect of subsurface drainage on agricultural catchment outflow has been debated for quite some time. Concerning downstream peak flow, it is a complex task to predict the impact of agricultural drainage because different flow media are involved: the soil, pipe drainage networks and open channel networks. In France, drain pipes are designed to operate under a free-surface flow condition. Nevertheless, during intense rainfall events, some pipe sections may flow under pressurised conditions, so that a complex interaction between pipe networks and groundwater flows appears in the vicinity of these sections. In this paper, an integrated modelling strategy is considered in order to analyse these flow interactions. A 1D Saint-Venant network model is combined with a 2D Boussinesq shallow groundwater flow model by means of special internal boundary conditions which take into account the flow interactions. This study follows field experiments conducted in a small subsurface drained catchment, where drainage discharge and pressure heads were monitored in a buried pipe collector and water table profiles were monitored in the field. The simulation results of the coupled model are in good agreement with experimental observations. Moreover, it satisfactorily simulates the behaviour of the drainage system during the pressurisation stages. The model is also applied to a scenario addressing the effect of pressurisation, as compared to non-pressurisation, at the outlet. The coupled model reveals the relation existing between pipe pressurisation and hydrograph timing. Pipe pressurisation results in temporary storage of discharging water, which is released later when pressurisation stops.

  14. Growth and Collapse of a Single Bubble near a Plate by Spark Discharge in Water

    NASA Astrophysics Data System (ADS)

    Akcam, I.; Inaba, K.; Takahashi, K.; Kishimoto, K.

    2015-12-01

    Single bubble dynamics in the vicinity of a solid boundary submerged in water were studied experimentally. Single bubble inside a water tank was generated by a spark discharge of capacitor into a couple of copper wires closing a simple circuit. A circular polycarbonate plate was placed horizontally above the bubble creation site. Polycarbonate plates with two different thicknesses were tested by changing the distance between the plate and the creation site. The effects of distance to the wall and wall thickness on the bubble motion is observed by considering the fluid-structure interaction. It is shown that motion of the two boundaries during the bubble generation differ from each other. Jetting behavior of two cases is also different.

  15. Dynamics of a wire-to-cylinder atmospheric pressure high-voltage nanosecond discharge

    SciTech Connect

    Levko, Dmitry; Raja, Laxminarayan L.

    2015-08-15

    The dynamics of a wire-to-cylinder atmospheric pressure high-voltage nanosecond discharge is studied by the one-dimensional Particle-in-Cell Monte Carlo collisions model in cylindrical coordinates. The x-ray photons emitted from the anode are found to be inconsequential to the generation of dense plasma in the gap. Rather, the electron impact ionization resulting from acceleration of naturally occurring background electrons in the discharge gap are enough to explain the generation of high-density (∼10{sup 15 }cm{sup −3}) non-equilibrium plasma. The influence of the high-voltage rise time on the plasma parameters is discussed.

  16. The impact of major earthquakes and subsequent sewage discharges on the microbial quality of water and sediments in an urban river.

    PubMed

    Devane, Megan L; Moriarty, Elaine M; Wood, David; Webster-Brown, Jenny; Gilpin, Brent J

    2014-07-01

    A series of large earthquakes struck the city of Christchurch, New Zealand in 2010-2011. Major damage sustained by the sewerage infrastructure required direct discharge of up to 38,000 m(3)/day of raw sewage into the Avon River of Christchurch for approximately six months. This allowed evaluation of the relationship between concentrations of indicator microorganisms (Escherichia coli, Clostridium perfringens and F-RNA phage) and pathogens (Campylobacter, Giardia and Cryptosporidium) in recreational water and sediment both during and post-cessation of sewage discharges. Giardia was the pathogen found most frequently in river water and sediment, although Campylobacter was found at higher levels in water samples. E. coli levels in water above 550 CFU/100 mL were associated with increased likelihood of detection of Campylobacter, Giardia and Cryptosporidium, supporting the use of E. coli as a reliable indicator for public health risk. The strength of the correlation of microbial indicators with pathogen detection in water decreased in the following order: E. coli>F-RNA phage>C. perfringens. All the microorganisms assayed in this study could be recovered from sediments. C. perfringens was observed to accumulate in sediments, which may have confounded its usefulness as an indicator of fresh sewage discharge. F-RNA phage, however, did not appear to accumulate in sediment and in conjunction with E. coli, may have potential as an indicator of recent human sewage discharge in freshwater. There is evidence to support the low-level persistence of Cryptosporidium and Giardia, but not Campylobacter, in river sediments after cessation of sewage discharges. In the event of disturbances of the sediment, it is highly probable that there could be re-mobilisation of microorganisms beyond the sediment-water exchange processes occurring under base flow conditions. Re-suspension events do, therefore, increase the potential risk to human health for those who participate in recreational

  17. The discharge mechanism of the high-temperature arc

    NASA Technical Reports Server (NTRS)

    Busz-Peuckert, G.; Finkelnburg, W.

    1984-01-01

    The mechanism of the high temperature Ar arc is interpreted considering those essential points in which it deviates from the known arcs based on earlier measurements and experiments. The following points are discussed individually: the charge carrier balance, the energy balance, the volt amp characteristics, and the difference between high temperature arcs in Ar and N. Besides the volt amp characteristic of a 10 mm long arc in Ar between 10 and 200 amp, the anode fall, cathode fall, and arc gradient were obtained with the aid of probes. The difference between Ar and N arcs are attributed to variations of the heat conditions and electrical conditions at different temperatures of the gas.

  18. Interim report on streamflow, sediment discharge, and water quality in the Calabazas Creek Basin, Santa Clara County, California

    USGS Publications Warehouse

    Knott, J.M.; Pederson, G.L.; Middelburg, Robert F.

    1978-01-01

    Streamflow, sediment-discharge, and water-quality data are being collected in the Calabazas Creek basin, Santa Clara County, Calif., to determine annual water and sediment discharge at base-line conditions that are representative of a basin prior to urbanization. Results of the first 3 years of the study (1973-75) are given in this report. Climatic conditions during this period were representative of a very wet year (1973) and 2 years of above-average rainfall (1974 and 1975). Daily water and sediment discharge were monitored at three primary stations, and periodic measurements were made at five secondary stations during selected storms. Most of the total annual sediment discharge at each station was transported during a few days each year. Maximum daily sediment discharge in a given year ranged from 23 to 62 percent of the annual total. Daily water discharge at the gaging station Calabazas Creek at Rainbow Drive, near Cupertino, ranged from no flow to 3.31 cubic meters per second. Streamflow at this location was significantly augmented during low flow by diversion of water from the South Bay Aqueduct. Annual sediment discharge at Calabazas Creek at Rainbow Drive was 4,900 t in 1974 and 9,570 t in 1975. A large quantity of sediment was trapped in a debris basin at Comer Drive upstream from this station during both years. If this sediment had not been trapped, sediment discharge at the station would have been about 35 percent greater in 1974 and 30 percent greater in 1975. Most of the trapped sediment consists of sand and gravel that would probably have been deposited in the Calabazas Creek channel downstream from the station. (Woodard-USGS)

  19. Temporal evolution of temperature and OH density produced by nanosecond repetitively pulsed discharges in water vapour at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Sainct, F. P.; Lacoste, D. A.; Kirkpatrick, M. J.; Odic, E.; Laux, C. O.

    2014-02-01

    We report on an experimental study of the temporal evolution of OH density and gas temperature in spark discharges created by nanosecond repetitively pulsed discharges in pure water vapour at 475 K and atmospheric pressure. The plasma was generated by 20 kV, 20 ns pulses, at a repetition frequency of 10 kHz. The temperature was measured during the discharge by optical emission spectroscopy of the second positive system of N2, and between two discharges by two-colour OH-planar laser induced fluorescence (OH-PLIF) using two pairs of rotational transitions. Between two successive discharges, the relative density of OH was measured by OH-PLIF and was found to decay very slowly, with a 1/e decay time of about 50 µs. With the use of a chemical kinetics model, the OH density was placed on an absolute scale.

  20. Dependence of recycling and edge profiles on lithium evaporation in high triangularity, high performance NSTX H-mode discharges

    NASA Astrophysics Data System (ADS)

    Maingi, R.; Osborne, T. H.; Bell, M. G.; Bell, R. E.; Boyle, D. P.; Canik, J. M.; Diallo, A.; Kaita, R.; Kaye, S. M.; Kugel, H. W.; LeBlanc, B. P.; Sabbagh, S. A.; Skinner, C. H.; Soukhanovskii, V. A.

    2015-08-01

    In this paper, the effects of a pre-discharge lithium evaporation variation on highly shaped discharges in the National Spherical Torus Experiment (NSTX) are documented. Lithium wall conditioning ('dose') was routinely applied onto graphite plasma facing components between discharges in NSTX, partly to reduce recycling. Reduced Dα emission from the lower and upper divertor and center stack was observed, as well as reduced midplane neutral pressure; the magnitude of reduction increased with the pre-discharge lithium dose. Improved energy confinement, both raw τE and H-factor normalized to scalings, with increasing lithium dose was also observed. At the highest doses, we also observed elimination of edge-localized modes. The midplane edge plasma profiles were dramatically altered, comparable to lithium dose scans at lower shaping, where the strike point was farther from the lithium deposition centroid. This indicates that the benefits of lithium conditioning should apply to the highly shaped plasmas planned in NSTX-U.

  1. Residence times and nitrate transport in ground water discharging to streams in the Chesapeake Bay Watershed

    USGS Publications Warehouse

    Lindsey, Bruce D.; Phillips, Scott; Donnelly, Colleen A.; Speiran, Gary K.; Plummer, L. Niel; Bohlke, John-Karl; Focazio, Michael J.; Burton, William C.; Busenberg, Eurybiades

    2003-01-01

    One of the major water-quality problems in the Chesapeake Bay is an overabundance of nutrients from the streams and rivers that discharge to the Bay. Some of these nutrients are from nonpoint sources such as atmospheric deposition, agricultural manure and fertilizer, and septic systems. The effects of efforts to control nonpoint sources, however, can be difficult to quantify because of the lag time between changes at the land surface and the response in the base-flow (ground water) component of streams. To help resource managers understand the lag time between implementation of management practices and subsequent response in the nutrient concentrations in the base-flow component of streamflow, a study of ground-water discharge, residence time, and nitrate transport in springs throughout the Chesapeake Bay Watershed and in four smaller watersheds in selected hydrogeomorphic regions (HGMRs) was conducted. The four watersheds were in the Coastal Plain Uplands, Piedmont crystalline, Valley and Ridge carbonate, and Valley and Ridge siliciclastic HGMRs. A study of springs to estimate an apparent age of the ground water was based on analyses for concentrations of chlorofluorocarbons in water samples collected from 48 springs in the Chesapeake Bay Watershed. Results of the analysis indicate that median age for all the samples was 10 years, with the 25th percentile having an age of 7 years and the 75th percentile having an age of 13 years. Although the number of samples collected in each HGMR was limited, there did not appear to be distinct differences in the ages between the HGMRs. The ranges were similar between the major HGMRs above the Fall Line (modern to about 50 years), with only two HGMRs of small geographic extent (Piedmont carbonate and Mesozoic Lowland) having ranges of modern to about 10 years. The median values of all the HGMRs ranged from 7 to 11 years. Not enough samples were collected in the Coastal Plain for comparison. Spring samples showed slightly

  2. High-voltage pulsed generators for electro-discharge technologies

    NASA Astrophysics Data System (ADS)

    Kovalchuk, B. M.; Kharlov, A. V.; Kumpyak, E. V.; Sinebrykhov, V. A.

    2013-09-01

    A high-voltage pulse technology is one of effective techniques for the disintegration and milling of rocks, separation of ores and synthesized materials, recycling of building and elastoplastic materials. We present here the design and test results of two portable HV pulsed generators, designed for materials fragmentation, though some other technological applications are possible as well. Generator #1 consists of low voltage block, high voltage transformer, high voltage capacitive storage block, two electrode gas switch, fragmentation chamber and control system block. Technical characteristics of the #1 generator: stored energy in HV capacitors can be varied from 50 to 1000 J, output voltage up to 300 kV, voltage rise time ~ 50 ns, typical operation regime 1000 pulses bursts with a repetitive rate up to 10 Hz. Generator #2 is made on an eight stages Marx scheme with two capacitors (100 kV-400 nF) per stage, connected in parallel. Two electrode spark gap switches, operated in atmospheric air, are used in the Marx generator. Parameters of the generator: stored energy in capacitors 2÷8 kJ, amplitude of the output voltage 200÷400 kV, voltage rise time on a load 50÷100 ns, repetitive rate up to 0.5 Hz. The fragmentation process can be controlled within a wide range of parameters for both generators.

  3. Bacteriological quality of abattoir effluents discharged into water bodies in abuja, Nigeria.

    PubMed

    Nafarnda, W D; Ajayi, I E; Shawulu, J C; Kawe, M S; Omeiza, G K; Sani, N A; Tenuche, O Z; Dantong, D D; Tags, S Z

    2012-01-01

    Bacteriological characteristics of abattoir effluents (wastewater), abattoir water source, and water bodies receiving abattoir wastewater were investigated in Abuja, Nigeria using the multiple-tube fermentation technique. Source of water to the abattoirs and the usage of water bodies receiving abattoir effluents were determined using questionnaires. Bacterial counts ranged from 4.8 × 10(6) to 5.8 × 10(5) /100 mL of total coliform (TC), 8.2 × 10(4) to 3.2 × 10(4)/100 mL of Fecal coliform (FC), 5.2 × 10(4) to 2.0 × 10(4)/100 mL of Fecal streptococcus and 1.2 × 10(4) to 2.0 × 10(3)/100 mL of Escherichia coli for abattoir effluents 6.6 × 10(5) to 6.0 × 10(5)/100 mL of TC, 6.2 × 10(4) to 1.8 × 10(4)/100 mL of FC, 1.8 × 10(4) to 6.0 × 10(3)/100 mL of F. streptococcus, and 4.8 × 10(3) to 6.6 × 10(2)/100 mL of E. coli for water bodies receiving abattoir effluents 100 m downstream. TC bacteria counts for abattoir effluents exceeded recommended limit for discharge into surface water in Nigeria. No significant difference (P < 0.05) was observed between bacterial counts of abattoir effluents and receiving water bodies 100 m downstream: an indication of contamination of receiving water bodies by abattoir effluents and possible public and environmental health hazards. PMID:23738127

  4. Numerical Simulation of Non-Equilibrium Plasma Discharge for High Speed Flow Control

    NASA Astrophysics Data System (ADS)

    Balasubramanian, Ramakrishnan; Anandhanarayanan, Karupannasamy; Krishnamurthy, Rajah; Chakraborty, Debasis

    2016-06-01

    Numerical simulation of hypersonic flow control using plasma discharge technique is carried out using an in-house developed code CERANS-TCNEQ. The study is aimed at demonstrating a proof of concept futuristic aerodynamic flow control device. The Kashiwa Hypersonic and High Temperature wind tunnel study of plasma discharge over a flat plate had been considered for numerical investigation. The 7-species, 18-reaction thermo-chemical non-equilibrium, two-temperature air-chemistry model due Park is used to model the weakly ionized flow. Plasma discharge is modeled as Joule heating source terms in both the translation-rotational and vibrational energy equations. Comparison of results for plasma discharge at Mach 7 over a flat plate with the reference data reveals that the present study is able to mimic the exact physics of complex flow such as formation of oblique shock wave ahead of the plasma discharge region with a resultant rise in surface pressure and vibrational temperature up to 7000 K demonstrating the use of non-equilibrium plasma discharge for flow control at hypersonic speeds.

  5. An asymmetric Zn//Ag doped polyaniline microparticle suspension flow battery with high discharge capacity

    NASA Astrophysics Data System (ADS)

    Wu, Sen; Zhao, Yongfu; Li, Degeng; Xia, Yang; Si, Shihui

    2015-02-01

    In this study, the effect of oxygen on the potential of reduced polyaniline (PANI) was investigated. In order to enhance the air oxidation of reduced PANI, several composites of PANI doped with co-catalysts were prepared, and a reasonable flow Zn//PANI suspension cell system was designed to investigate the discharge capacity of obtained PANI composite microparticle suspension cathodes. Compared with PANI doped with Cu2+, La+, Mn2+ and zinc protoporphyrin, Ag doped PANI composite at 0.90 weight percent doping of Ag gave the highest value of discharge capacity for the half-cell potential from the initial value to -0.20 V (vs. SCE). A comparison study on the electrochemical properties of both PANI and Ag doped PANI microparticle suspension was done by using cyclic voltammetry, AC Impedance. Due to partial utilization of Zn//air fuel cell, the discharge capacity for Ag doped PANI reached 470 mA h g-1 at the current density of 20 mA cm-2. At 15 mA cm-2, the discharge capacity even reached up to 1650 mA h g-1 after 220 h constant current discharge at the final discharge voltage of 0.65 V. This work demonstrates an effective and feasible approach toward obtaining high energy and power densities by a Zn//Ag-doped PANI suspension flow battery system combined with Zn//air fuel cell.

  6. Sediment filtration can reduce the N load of the waste water discharge - a full-scale lake experiment

    NASA Astrophysics Data System (ADS)

    Aalto, Sanni L.; Saarenheimo, Jatta; Karvinen, Anu; Rissanen, Antti J.; Ropponen, Janne; Juntunen, Janne; Tiirola, Marja

    2016-04-01

    European commission has obliged Baltic states to reduce nitrate load, which requires high investments on the nitrate removal processes and may increase emissions of greenhouse gases, e.g. N2O, in the waste water treatment plants. We used ecosystem-scale experimental approach to test a novel sediment filtration method for economical waste water N removal in Lake Keurusselkä, Finland between 2014 and 2015. By spatially optimizing the waste water discharge, the contact area and time of nitrified waste water with the reducing microbes of the sediment was increased. This was expected to enhance microbial-driven N transformation and to alter microbial community composition. We utilized 15N isotope pairing technique to follow changes in the actual and potential denitrification rates, nitrous oxide formation and dissimilatory nitrate reduction to ammonium (DNRA) in the lake sediments receiving nitrate-rich waste water input and in the control site. In addition, we investigated the connections between observed process rates and microbial community composition and functioning by using next generation sequencing and quantitative PCR. Furthermore, we estimated the effect of sediment filtration method on waste water contact time with sediment using the 3D hydrodynamic model. We sampled one year before the full-scale experiment and observed strong seasonal patterns in the process rates, which reflects the seasonal variation in the temperature-related mixing patterns of the waste water within the lake. During the experiment, we found that spatial optimization enhanced both actual and potential denitrification rates of the sediment. Furthermore, it did not significantly promote N2O emissions, or N retention through DNRA. Overall, our results indicate that sediment filtration can be utilized as a supplemental or even alternative method for the waste water N removal.

  7. Transit time of water discharges from catchments in coastal mountain of Chile

    NASA Astrophysics Data System (ADS)

    Bustamante-Ortega, Ramon; Morgenstern, Uwe; Ramirez de Arellano, Pablo

    2015-04-01

    Water quantity and quality response of forest catchments to climate and land-use change are difficult to understand and predict due to complexities of subsurface water flow paths. The main focus of forest hydrology in Chile has been the effect of canopy and soil together with rain in water availability. Groundwater, as a factor in water availability especially during dry season, has not been studied. Only a few studies have been carried out in northern Chile in a non-forestry area using the stable isotopes of the water to characterize recharge and depletion of the aquifer. We use tritium for understanding the dynamics of groundwater through small watersheds over a latitudinal gradient in the coastal range of Central Chile. The zone constitutes rapid growth plantations and a large population that depend on surface water and groundwater for drinking, agriculture, pasture and industry. The study areas have metamorphic bedrock with a Mediterranean weather, and precipitation ranging from 700-800 mm year-1 in the North (Constitución area) to 2300-2500 mm year-1 in the South (Valdivia area). The watersheds have been forested with Pinus radiata in 2003 and 1990 respectively, and flow stations were installed in 2008 by Forestal Arauco S.A. to identify the forest management impact on the water cycle. Tritium is present in meteoric water and decays through radioactive decay. In groundwater, which is separated from the tritium production source in the atmosphere, the tritium concentration decreases over time and therefore allows for determination of the residence time of the water in the groundwater system, and the lag time between recharge of the water, and discharge into the streams. Preliminary results of rain samples collected in 2014 in Constitución confirm the tritium input estimate that we made using the New Zealand input data from similar latitude, and the IAEA data (http://www-naweb.iaea.org/napc/ih/IHS_resources_gnip.html). The mean residence time of the water in

  8. High-Efficiency Hall Thruster Discharge Power Converter

    NASA Technical Reports Server (NTRS)

    Jaquish, Thomas

    2015-01-01

    Busek Company, Inc., is designing, building, and testing a new printed circuit board converter. The new converter consists of two series or parallel boards (slices) intended to power a high-voltage Hall accelerator (HiVHAC) thruster or other similarly sized electric propulsion devices. The converter accepts 80- to 160-V input and generates 200- to 700-V isolated output while delivering continually adjustable 300-W to 3.5-kW power. Busek built and demonstrated one board that achieved nearly 94 percent efficiency the first time it was turned on, with projected efficiency exceeding 97 percent following timing software optimization. The board has a projected specific mass of 1.2 kg/kW, achieved through high-frequency switching. In Phase II, Busek optimized to exceed 97 percent efficiency and built a second prototype in a form factor more appropriate for flight. This converter then was integrated with a set of upgraded existing boards for powering magnets and the cathode. The program culminated with integrating the entire power processing unit and testing it on a Busek thruster and on NASA's HiVHAC thruster.

  9. Constant Light Output Ballasting For High Intensity Discharge Lamps

    NASA Astrophysics Data System (ADS)

    Donkin, Adrian

    1988-02-01

    Since the commercial introduction some twenty years ago of HMI* (Hydragyrum-mercury, Medium, Iodide) type lamps, as a source intended primarily for floodlighting applications, their attraction as a cinematographic light source has been apparent due to their largely desirable characteristics. Use in this field has been restricted due to the absolute requirement for an alternating current supply - with a sine wave supply frame rates are limited to a sub-multiple of the supply frequency with the supply frequency phase locked to the camera frame rate. This has effectively barred metal halide HID lighting from use in high speed photography. The general characteristics of metal halide HID lamps are presented alongside a sample of other light sources. An electronic ballast which has been proven to 12000 Watts in the motion picture industry is then described which overcomes the limitations of the conventional magnetic ballast - the square wave output of the electronic ballast theoretically allows the use of any camera frame rate/shutter angle combination. Finally the suitability of luminaires for high speed photography is discussed.

  10. Angina - discharge

    MedlinePlus

    ... bypass surgery - minimally invasive - discharge Heart disease - risk factors High ... of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed ...

  11. SUPPLEMENT TO EFFECTS OF THERMAL DISCHARGES ON PHYSICO-CHEMICAL PROCESSES AND WATER QUALITY, VISTULA RIVER, POLAND

    EPA Science Inventory

    The study on the influence of thermal water discharge from the open cooling system of the Kozienice power plant on the thermal regimes and water quality of the Vistula River was carried out in the period from January 1973 to December 1975. Studies carried out downstream of the pl...

  12. Fluorescent and high intensity discharge lamp use in chambers and greenhouses

    NASA Technical Reports Server (NTRS)

    Langhans, Robert W.

    1994-01-01

    Fluorescent and High Intensity Discharge lamps have opened up great opportunities for researchers to study plant growth under controlled environment conditions and for commercial growers to increase plant production during low/light periods. Specific technical qualities of fluorescent and HID lamps have been critically reviewed. I will direct my remarks to fluorescent and high intensity discharge (HID) lamps in growth chambers, growth rooms, and greenhouses. I will discuss the advantages and disadvantages of using each lamp in growth chambers, growth rooms and greenhouses.

  13. Effect of the Discharge Water which Mixed Sewage Disposal Water with Seawater Desalting Treated Sewage for Bottom Sediment and Hypoxic Water Mass

    NASA Astrophysics Data System (ADS)

    Watanabe, Ryoichi; Yamasaki, Koreyoshi; Minagawa, Tomoko; Iyooka, Hiroki; Kitano, Yoshinori

    For every time in summer season, hypoxic water mass has formed at the inner part of Hakata Bay. Field observation study has carried out at the inner part of Hakata Bay since 2004 with the particular aim of tracking the movement of hypoxic water mass. Hypoxic water masses form the end of June to September on this area because the consumption of oxygen in bottom water layers exceeds the re-supply of oxygen from the atmosphere. Under such hypoxic conditions, the seawater desalination plant has begun to use in 2005. After seawater desalination plant operation starting, hypoxic water mass tends to improve. In this research, the authors show the following result. After seawater desalination plant has begun to operate, the hypoxia around the mixed discharge water outlet tends to be improved.

  14. Discharge Physics of High Power Impulse Magnetron Sputtering

    SciTech Connect

    Anders, Andre

    2010-10-13

    High power impulse magnetron sputtering (HIPIMS) is pulsed sputtering where the peak power exceeds the time-averaged power by typically two orders of magnitude. The peak power density, averaged over the target area, can reach or exceed 107 W/m2, leading to plasma conditions that make ionization of the sputtered atoms very likely. A brief review of HIPIMS operation is given in a tutorial manner, illustrated by some original data related to the self-sputtering of niobium in argon and krypton. Emphasis is put on the current-voltage-time relationships near the threshold of self-sputtering runaway. The great variety of current pulse shapes delivers clues on the very strong gas rarefaction, self-sputtering runaway conditions, and the stopping of runaway due to the evolution of atom ionization and ion return probabilities as the gas plasma is replaced by metal plasma. The discussions are completed by considering instabilities and the special case of ?gasless? self-sputtering.

  15. The persistent microbicidal effect in water exposed to the corona discharge.

    PubMed

    Julák, Jaroslav; Scholtz, Vladimír; Kotúčová, Soňa; Janoušková, Olga

    2012-07-01

    This article describes and particularly explains a new phenomenon of persistent microbicidal effect of water previously exposed to the low-temperature plasma, which cannot be attributed to the acidification only. The direct microbicidal action of plasma is well documented, being mediated by number of reactive particles with a short lifetime. However, we observed the microbicidal effect also in exposed water stored for a month, where it must be mediated by stable particles. In water and in phosphate-buffered saline, the formation of NO(x) and corresponding acids, H(2)O(2) and O(3) was confirmed after exposition to the low-temperature plasma generated in air by DC negative glow corona and positive streamer discharge. The time course of acidification, H(2)O(2) and O(3) formation were deremined. Except uncertain traces of HCN, SIFT-MS analysis of exposed liquids reveals no additional reactive compounds. The microbicidal effect persists almost unchanged during 4 weeks of storage, although O(3) completely and H(2)O(2) almost disappears. Staphylococcus epidermidis and Escherichia coli were inactivated within 10 min of incubation in exposed liquids, Candida albicans needs at least 1 h. The solutions prepared by artificial mixing of reactive compounds mimic the action of exposed water, but in lesser extent. The acid milieu is the main cause of the microbicidal effect, but the possibility of still unidentified additional compound remains open. PMID:21925912

  16. Forested wetland mitigation resulting from discharges of cooling water into streams

    SciTech Connect

    Nelson, E.A. )

    1993-01-01

    The Savannah River Swamp is a 3020-ha forested wetland on the floodplain of the Savannah River and is located on the US Department of Energy's Savannah River Site (SRS) near Aiken, South Carolina. Historically, the swamp consisted of [approximately]50% bald cypress-water tupelo stands, 40% mixed bottomland hardwood stands, and 10% shrub, marsh, and open water. The hydrology was controlled by flooding the Savannah River and by flow from four creeks that drain into the swamp prior to flow into the Savannah River. Upstream dams have caused some alteration of the water levels and timing of flooding within the floodplain. Major impacts to the swamp hydrology occurred with the completion of the production reactors and one coal-fired powerhouse at the SRS in the early 1950s. Water, often in excess of 40 to 50[degrees]C was discharged into one of the small streams from 1954 to 1988, at various levels, ranging from 20 to 40 times the prior flow rate of the stream. This had a major impact on the adjacent swamp land, with erosion, silting, and vegetation destruction. The Final Environmental Impact Statement, Continued Operation of K, L, and P Reactors, Savannah River Site, Aiken, South Carolina, and the subsequent record of decision directed that these areas be restored to functional forested wetland status to the extent possible. This paper describes work begun to reach that objective.

  17. High-pressure pulsed avalanche discharges: Formulas for required preionization density and rate for homogeneity

    SciTech Connect

    Brenning, N.; Axnaes, I.; Nilsson, J.O.; Eninger, J.E.

    1997-02-01

    The requirements on preionization for the formation of spatially homogeneous pulsed avalanche discharges are examined. The authors derive two formulas which apply in the case of a slowly rising electric field, one which gives the required preionization density at breakdown, and one which gives the required preionization rate. These quantities are expressed as functions of the electrochemical properties of the gas, the neutral density, and the electric field rise time. They also treat the statistical effect that the electrons tend to form groups, in contrast to being randomly distributed in space, during the prebreakdown phase. This process is found to increase the required preionization rate significantly, typically by a factor of five for a discharge at atmospheric pressure. Homogeneous high-pressure discharges have been used for laser excitation, and have also been proposed for chemical plasma processing (ozone production) because of their good scaling properties and high efficiency.

  18. Compression and strong rarefaction in high power impulse magnetron sputtering discharges

    SciTech Connect

    Horwat, David; Anders, Andre

    2010-11-11

    Gas compression and strong rarefaction have been observed for high power impulse magnetron sputtering (HIPIMS) discharges using a copper target in argon. Time-resolved ion saturation currents of 35 probes were simultaneously recorded for HIPIMS discharges operating far above the self-sputtering runaway threshold. The argon background pressure was a parameter for the evaluation of the spatial and temporal development of the plasma density distribution. The data can be interpreted by a massive onset of the sputtering flux (sputter wind) that causes a transient densification of the gas, followed by rarefaction and the replacement of gas plasma by the metal plasma of sustained self-sputtering. The plasma density pulse follows closely the power pulse at low pressure. At high pressure, the relatively remote probes recorded a density peak only after the discharge pulse, indicative for slow, diffusive ion transport.

  19. Plasma Emission Characteristics from a High Current Hollow Cathode in an Ion Thruster Discharge Chamber

    NASA Technical Reports Server (NTRS)

    Foster, John E.; Patterson, Michael J.

    2002-01-01

    The presence of energetic ions produced by a hollow cathodes operating at high emission currents (greater than 5A) has been documented in the literature. In order to further elucidate these findings, an investigation of a high current cathode operating in an ion thruster discharge chamber has been undertaken. Using Langmuir probes, a low energy charged particle analyzer and emission spectroscopy, the behavior of the near-cathode plasma and the emitted ion energy distribution was characterized. The presence of energetic ions was confirmed. It was observed that these ions had energies in excess of the discharge voltage and thus cannot be simply explained by ions falling out of plasma through a potential difference of this order. Additionally, evidence provided by Langmuir probes suggests the existence of a double layer essentially separating the hollow cathode plasma column from the main discharge. The radial potential difference associated with this double layer was measured to be of order the ionization potential.

  20. Matching of an extended high-current Z-discharge to a pulsed power system

    NASA Astrophysics Data System (ADS)

    Burtsev, V. A.; Kalinin, N. V.

    2013-08-01

    Conditions for matching an extended high-current Z-discharge to a pulsed power system are numerically investigated. The power system consists of a pulsed voltage generator and a long transmission line. Experiments are aimed at generating a highly ionized dense plasma as an active medium for an extreme ultraviolet laser on hydrogen-like ions of nitrogen (λ = 13.4 nm). Emphasis is on the distribution of the energy transmitted from a storage ring to a load among its components and on the reduction of the energy that remains in the electrical circuit by the end of the pump pulse and will inevitably dissipate in the discharge tube. The solution of this problem will make it possible to diminish the load on the walls of the discharge chamber and extend its service life. It is shown that energy deposition into the load is effective when the timeaveraged sum of the ohmic and dynamic components of the discharge resistance is roughly equal to the wave impedance of the transmission line. In this case, the wave reflected from the load carries away a minimal energy, which allows for optimization of the energy deposited into the load. The input and output energy balances for different matching conditions are calculated with an eye to designing an efficient short-wavelength extreme ultraviolet laser with a long service life of the discharge tube.

  1. Patterns of Phrenic Nerve Discharge after Complete High Cervical Spinal Cord Injury in the Decerebrate Rat.

    PubMed

    Ghali, Michael George Zaki; Marchenko, Vitaliy

    2016-06-15

    Studies conducted since the second half of the 19th century have revealed spontaneous as well as pharmacologically induced phasic/rhythmic discharge in spinal respiratory motor outputs of cats, dogs, rabbits, and neonatal rats following high cervical transection (Tx). The extent to which these various studies validate the existence of a true spinal respiratory rhythm generator remains debated. In this set of studies, we seek to characterize patterns of spontaneous phasic/rhythmic, asphyxia-induced, and pharmacologically induced activity occurring in phrenic nerve (PhN) discharge after complete high cervical (C1-C2) spinal cord transection. Experiments were performed on 20 unanesthetized decerebrate Sprague-Dawley adult male rats. Patterns of spontaneous activity after spinalization included tonic, phasic, slow oscillatory, and long-lasting tonic discharges. Topical application of antagonists of GABAA and glycine receptors to C1- and C2- spinal segments induced left-right synchronized phasic decrementing activity in PhN discharge that was abolished by an additional C2Tx. Asphyxia elicited increases in tonic activity and left-right synchronized gasp-like bursts in PhN discharge, demonstrating the presence of spinal circuits that may underlie a spinal gasping-like mechanism. We conclude that intrinsic slow oscillators and a phasic burst/rhythm generator exist in the spinal cord of the adult rat. If present in humans, this mechanism may be exploited to recover respiratory function in patients sustaining severe spinal cord injury. PMID:26239508

  2. Radiative heat transfer in plasma of pulsed high pressure caesium discharge

    NASA Astrophysics Data System (ADS)

    Lapshin, V. F.

    2016-01-01

    Two-temperature many component gas dynamic model is used for the analysis of features of radiative heat transfer in pulsed high pressure caesium discharge plasma. It is shown that at a sufficiently high pressure the radial optical thickness of arc column is close to unit (τR (λ) ∼ 1) in most part of spectrum. In this case radiative heat transfer has not local character. In these conditions the photons which are emitted in any point of plasma volume are absorbed in other point remote from an emission point on considerable distance. As a result, the most part of the electric energy put in the discharge mainly near its axis is almost instantly redistributed on all volume of discharge column. In such discharge radial profiles of temperature are smooth. In case of low pressure, when discharge plasma is optically transparent for own radiation in the most part of a spectrum (τR(λ) << 1), the emission of radiation without reabsorption takes place. Radiative heat transfer in plasma has local character and profiles of temperature have considerable gradient.

  3. Measuring the Thermal Conductivity of Sediments for the Estimation of Groundwater Discharge to Surface Waters with Temperature Probes

    NASA Astrophysics Data System (ADS)

    Duque, C.; Müller, S.; Sebok, E.; Engesgaard, P. K.

    2015-12-01

    Using temperature probes is a common exploratory method for studying groundwater-surface water interaction due to the ease for collecting measurements and the simplicity of the different analytical solutions. This approach requires to define the surface water temperature, the groundwater temperature and a set of parameters (density and specific capacity of water, and thermal conductivity of sediments) that can be easily extracted from tabulated values under the assumption that they are homogeneous in the study area. In the case of the thermal conductivity, it is common to apply a standard value of 1.84 Wm-1 C-1 corresponding to sand. Nevertheless the environments where this method is applied, like streambeds or lake/lagoons shores, are sedimentary depositional systems with high energy and biological activity that often lead to sediments dominated by organic matter or sharp changes in grain size modifying greatly the thermal conductivity values. In this study, the thermal conductivity was measured in situ along transects where vertical temperature profiles were collected in a coastal lagoon bed receiving groundwater discharge (Ringkøbing Fjord, Denmark). A set of 4 transects with 10-20 temperature profiles during 3 different seasons was analyzed together with more than 150 thermal conductivity measurements along the working transects and in experimental parcels of 1 m2 where the cm scale spatial variability of the thermal conductivity was assessed. The application of a literature-based bulk thermal conductivity of 1.84 Wm-1 C-1 instead of field data that ranged from 0.62 to 2.19 Wm-1 C-1, produced a mean flux overestimation of 2.33 cm d-1 that, considering the low fluxes of the study area, represents an increase of 89 % and up to a factor of 3 in the most extreme cases. The changes in thermal conductivity can alter the estimated fluxes hindering the detection of patterns in groundwater discharge and modifying the interpretation of the results.

  4. A time-resolved imaging and electrical study on a high current atmospheric pressure spark discharge

    NASA Astrophysics Data System (ADS)

    Palomares, J. M.; Kohut, A.; Galbács, G.; Engeln, R.; Geretovszky, Zs.

    2015-12-01

    We present a time-resolved imaging and electrical study of an atmospheric pressure spark discharge. The conditions of the present study are those used for nanoparticle generation in spark discharge generator setups. The oscillatory bipolar spark discharge was generated between two identical Cu electrodes in different configurations (cylindrical flat-end or tipped-end geometries, electrode gap from 0.5 to 4 mm), in a controlled co-axial N2 flow, and was supplied by a high voltage capacitor. Imaging data with nanosecond time resolution were collected using an intensified CCD camera. This data were used to study the time evolution of plasma morphology, total light emission intensity, and the rate of plasma expansion. High voltage and high current probes were employed to collect electrical data about the discharge. The electrical data recorded allowed, among others, the calculation of the equivalent resistance and inductance of the circuit, estimations for the energy dissipated in the spark gap. By combining imaging and electrical data, observations could be made about the correlation of the evolution of total emitted light and the dissipated power. It was also observed that the distribution of light emission of the plasma in the spark gap is uneven, as it exhibits a "hot spot" with an oscillating position in the axial direction, in correlation with the high voltage waveform. The initial expansion rate of the cylindrical plasma front was found to be supersonic; thus, the discharge releases a strong shockwave. Finally, the results on equivalent resistance and channel expansion are comparable to those of unipolar arcs. This shows the spark discharge has a similar behavior to the arc regime during the conductive phase and until the current oscillations stop.

  5. Degradation of TAIC by water falling film dielectric barrier discharge--influence of radical scavengers.

    PubMed

    Rong, Shaopeng; Sun, Yabing

    2015-04-28

    This work describes the application of plasma generated by water falling film dielectric barrier discharge for the degradation of triallyl isocyanurate (TAIC). The results indicated that TAIC solution of 1000mg/L was effectively removed within 60min treatment at 120W output power. Six intermediates were identified and a possible evolution of the TAIC degradation process was continuously proposed basing on the results of mass spectrum analysis. The effects of metal ions and radical scavengers were investigated. Results showed that whatever hydrogen radical scavengers (carbon tetrachloride, perfluorooctane) or hydroxyl radical scavengers (iso-propyl alcohol, tert-butyl alcohol) all could further enhance the degradation processes, and both kings of radical scavengers could promote the generation of H2O2. In the present study, we employed a novel method by introducing the mixed additives of Fe(2+) and radical scavengers into the plasma. It was found that the reaction rate constant and energy efficiency were improved by 309.2% and 387.8%, respectively. Among the mixed additives, Fe(2+) could promote the decomposition and increase the oxidizing power of H2O2, which is generated from the plasma discharge and greatly enhanced by the radical scavengers. PMID:25668300

  6. Recovery of water tables in Welsh blanket bog after drain blocking: Discharge rates, time scales and the influence of local conditions

    NASA Astrophysics Data System (ADS)

    Wilson, Lorraine; Wilson, Jared; Holden, Joseph; Johnstone, Ian; Armstrong, Alona; Morris, Michael

    2010-09-01

    SummaryPeatland practitioners and scientists have increasingly recognised the damage resulting from various management methods, and the need to restore peatlands to achieve several potential benefits. Many of the hoped-for benefits of peatland restoration, such as Carbon storage, biodiversity conservation and water quality improvements, are thought to depend on a reinstatement of high water tables that had been reduced by drainage. Despite the current emphasis on restoring drained peatlands, many of the predicted responses to restoration are still not adequately proven and the mechanisms behind them still uncertain. This study reports on water table and discharge responses to drain blocking restoration of a degraded Welsh upland blanket bog. Restoration work and monitoring were designed to permit a novel catchment scale control-intervention experimental design. An information theoretic approach to examining the data provided evidence of increases in water retention and water tables within the bog after restoration. But the study also demonstrated the importance of small and large scale topography in determining the degree of these responses. The increases in water storage after restoration produced lower discharge rates observable at the level of both drains and hill streams; as well as greater water table stability, reduction in peak flows and increases in water residency after rainfall. Crucially, this study showed strong catchment scale differences in response, and a very gradual recovery of water tables, both of which highlight the need for more studies to be carried out at the landscape scale and over longer time periods.

  7. Ground-water discharge by evapotranspiration in a desert environment of southern Nevada, 1987

    USGS Publications Warehouse

    Johnson, M.J.

    1994-01-01

    Evapotranspiration (ET) data were collected at two sites where microclimates are typical of the Mojave Desert in southern Nevada-one site with and one without ground-water contributions to ET--under extremely arid desert conditions. By comparing the rate of evapotranspiration at the two sites, the amount of ground-water ET can be inferred. This method may be useful for quantifying ground-water discharge by ET around basin playas or the summer carbonate-aquifer springs, ET rates are greatest in early spring, but are less than 0.6 millimeter per day (mm/d). As the summer progresses and soil moisture is depleted, ET drops below 0.1 mm/d and vegetation wilts. In areas'with a ground-water contribution, under similar climatic conditions, ET rates increase with increasing solar radiation and plant growth from 1 mm/d in winter to an average of 1.5 to 3.0 mm/d in spring. The highest average is about 5.0 mm/d, in June, July, and August, with fluctuations generally between 3.0 and 7.0 mm/d; the rate then decreases from 3.0 to less than 1.0 mm/d by late autumn. A comparison of monthly ET totals based on average daily rates at the two sites indicates that about 520 millimeters of ground water was lost to ET at Ash Meadows during the 6 months of record, April through September 1987. This is in general agreement with the range of values estimated for areas with native vegetation in the Amargosa Desert where the depth to water was between 0.0 and 1.5 meters. Estimated rates ranged from 320 to 760 millimeters per year.

  8. Evaporation and discharge dynamics of highly charged multicomponent droplets generated by electrospray ionization.

    PubMed

    Grimm, Ronald L; Beauchamp, J L

    2010-01-28

    We investigate the Rayleigh discharge and evaporation dynamics of highly charged two-component droplets consisting principally of methanol with 2-methoxyethanol, tert-butanol, or m-nitrobenzyl alcohol. A phase Doppler anemometer (PDA) characterizes droplets generated by electrospray ionization (ESI) according to size, velocity, and charge as they move through a uniform electric field within an ion mobility spectrometer (IMS). Repeated field reversals result in droplet "ping-pong" through the PDA. This generates individual droplet histories of solvent evaporation behavior and the dynamics of charge loss to progeny droplets during Rayleigh discharge events. On average, methanol droplets discharge at 127% their Rayleigh limit of charge, q(R), and release 25% of the net charge. Charge loss from methanol/2-methoxyethanol droplets behaves similarly to pure 2-methoxyethanol droplets which release approximately 28% of their net charge. Binary methanol droplets containing up to 50% tert-butanol discharge at a lower percent q(R) than pure methanol and release a greater fraction of their net charge. Mixed 99% methanol/1% m-nitrobenzyl alcohol droplets possess discharge characteristics similar to those of methanol. However, droplets of methanol containing 2% m-nitrobenzyl evaporate down to a fixed size and charge that remains constant with no observable discharges. Quasi-steady-state evaporation models accurately describe observed evaporation phenomena in which methanol/tert-butanol droplets evaporate at a rate similar to that of pure methanol and methanol/2-methoxyethanol droplets evaporate at a rate similar to that of 2-methoxyethanol. We compare these results to previous Rayleigh discharge experiments and discuss the implications for binary solvents in electrospray mass spectrometry (ESI-MS) and field-induced droplet ionization mass spectrometry (FIDI-MS). PMID:19848399

  9. The Rhine outflow: A prototypical pulsed discharge plume in a high energy shallow sea

    NASA Astrophysics Data System (ADS)

    de Ruijter, Wilhelmus P. M.; Visser, Andre W.; Bos, W. G.

    1997-08-01

    Over the past years, a wealth of data has been collected in the Rhine ROFI (Region Of Freshwater Influence) where freshwater from the Rhine is transported and dispersed along the Netherlands coast. The Rhine ROFI may be considered as a prototypical one, its spreading being relatively uncomplicated by coastal and bathymetric features. The discharge of the Rhine, and comparable rivers like the Connecticut, is heavily modulated by the tidal wave propagating into the estuary. As a result, this river water exits into the coastal zone as successive low salinity pulses. The processes and parameters involved in the development of such pulsed river plumes are qualitatively examined. The main criteria that lead to a pulsed discharge are that the net discharge is halted at some stage during the tidal cycle and that a pulse is sufficiently far removed from the river mouth after one tidal cycle so as not to interfere with the development of the successive pulses. From this we have derived necessary conditions for the formation of a pulsed discharge, namely (1) the maximal tidal current amplitude exceeds the river discharge velocity and (2) the inertial radius is larger than the river mouth width. Within this parameter regime rivers can thus be classified as falling within the pulsed plume regime or not. Mixing processes, particularly by winds and tides, are important at all times. Without wind and around neap tide (low mixing rates) the "life expectancy" of a typical Rhine pulse is of the order of a week, an upper bound. This order decreases quickly with increasing winds. However, then also velocities in the long shore "Dutch Coastal Current" go up. The observations show that under such extreme conditions a train of fresh water lenses can be transported along the Dutch coast.

  10. Water Quality Management With Time Varying River Flow and Discharger Control

    NASA Astrophysics Data System (ADS)

    Herbay, Jean-Pierre; Smeers, Yves; Tyteca, Daniel

    1983-12-01

    An extension of the classical river quality management problem is presented that allows for time varying operation of the treatment plants. The hydrology of the river is represented by a set of steady state flow regimes; a river water quality model is used for each of these regimes to give a constraint set to be imposed on the discharges in order to achieve the stream standards during that regime. The objective function distinguishes between investment costs, fixed operating costs, and variable operating costs. A treatment system is sought that minimizes the sum of these costs, taking account of the possibility of operating the treatment system at various different levels during the year. The model is quantified and tested on an example.

  11. Facile Carbon Fixation to Performic Acids by Water-Sealed Dielectric Barrier Discharge.

    PubMed

    Kawasaki, Mitsuo; Morita, Tatsuo; Tachibana, Kunihide

    2015-01-01

    Carbon fixation refers to the conversion of carbon dioxide (CO2) to organic materials, as commonly performed in nature through photosynthesis by plants and other autotrophic organisms. The creation of artificial carbon fixation processes is one of the greatest challenges for chemistry to solve the critical environmental issue concerning the reduction of CO2 emissions. We have developed an electricity-driven facile CO2 fixation process that yields performic acid, HCO2OH, from CO2 and water at neutral pH by dielectric barrier discharge with an input electric power conversion efficiency of currently 0.2-0.4%. This method offers a promising future technology for artificial carbon fixation on its own, and may also be scaled up in combination with e.g., the post-combustion CO2 capture and storage technology. PMID:26439402

  12. Facile Carbon Fixation to Performic Acids by Water-Sealed Dielectric Barrier Discharge

    NASA Astrophysics Data System (ADS)

    Kawasaki, Mitsuo; Morita, Tatsuo; Tachibana, Kunihide

    2015-10-01

    Carbon fixation refers to the conversion of carbon dioxide (CO2) to organic materials, as commonly performed in nature through photosynthesis by plants and other autotrophic organisms. The creation of artificial carbon fixation processes is one of the greatest challenges for chemistry to solve the critical environmental issue concerning the reduction of CO2 emissions. We have developed an electricity-driven facile CO2 fixation process that yields performic acid, HCO2OH, from CO2 and water at neutral pH by dielectric barrier discharge with an input electric power conversion efficiency of currently 0.2-0.4%. This method offers a promising future technology for artificial carbon fixation on its own, and may also be scaled up in combination with e.g., the post-combustion CO2 capture and storage technology.

  13. Facile Carbon Fixation to Performic Acids by Water-Sealed Dielectric Barrier Discharge

    PubMed Central

    Kawasaki, Mitsuo; Morita, Tatsuo; Tachibana, Kunihide

    2015-01-01

    Carbon fixation refers to the conversion of carbon dioxide (CO2) to organic materials, as commonly performed in nature through photosynthesis by plants and other autotrophic organisms. The creation of artificial carbon fixation processes is one of the greatest challenges for chemistry to solve the critical environmental issue concerning the reduction of CO2 emissions. We have developed an electricity-driven facile CO2 fixation process that yields performic acid, HCO2OH, from CO2 and water at neutral pH by dielectric barrier discharge with an input electric power conversion efficiency of currently 0.2−0.4%. This method offers a promising future technology for artificial carbon fixation on its own, and may also be scaled up in combination with e.g., the post-combustion CO2 capture and storage technology. PMID:26439402

  14. Spatial patterns of the evolution of the chemical composition and discharge of river water in the Ob River basin

    NASA Astrophysics Data System (ADS)

    Savichev, O. G.; Mazurov, A. K.; Pipko, I. I.; Sergienko, V. I.; Semiletov, I. P.

    2016-01-01

    The discharge of major cations and dissolved organic carbon (Corg) with water of the Ob River and its tributaries along the natural zones within the Ob River basin was calculated, and the contribution of the underground component to the volumes of total discharge of the Ob River basin was estimated. It was demonstrated that the total chemical composition of river water and the geochemical discharge in the Ob River basin were consistent with the zoned hydroclimatic conditions controlling the character and duration of interaction in the water-rock system. It was established that the average ionic discharge of the Ob River increased from 6-7 × 106 t/year near Barnaul to 46-47 × 106 t/year near Salekhard; the discharge of dissolved Corg increased from 0.1 × 106 to 3.8 × 106 t/year. Multiple enrichment of underground waters of the Ob River in dissolved organic matter from the upper to the lower reaches was revealed.

  15. Current-voltage-time characteristics of the reactive Ar/N{sub 2} high power impulse magnetron sputtering discharge

    SciTech Connect

    Magnus, F.; Sveinsson, O. B.; Olafsson, S.; Gudmundsson, J. T.

    2011-10-15

    The discharge current and voltage waveforms have been measured in a reactive high power impulse magnetron sputtering (HiPIMS) Ar/N{sub 2} discharge with a Ti target for 400 {mu}s long pulses. We observe that the current waveform in the reactive Ar/N{sub 2} HiPIMS discharge is highly dependent on the pulse repetition frequency, unlike the non-reactive Ar discharge. The current is found to increase significantly as the frequency is lowered. This is attributed to an increase in the secondary electron emission yield during the self-sputtering phase, when the nitride forms on the target at low frequencies. In addition, self-sputtering runaway occurs at lower discharge voltages when nitrogen is added to the discharge. This illustrates the crucial role of self-sputtering in the behavior of the reactive HiPIMS discharge.

  16. Liquid Atomization by a high Discharge Swirl Atomizer and its Characteristics

    NASA Astrophysics Data System (ADS)

    Katoh, Fumio

    The following are concluded for the High Discharge Swirl Atomizer, through theoretically analyzing liquid film disintegration, analysis and experiment for a liquid immersion process, and the measurement of liquid film thickness. (a) A new liquid immersion process is developed, presenting the method of determining a mean droplet diameter. (b) Empirical formulae are given for the atomization characteristics and discharge characteristics with the figures of a swirl atomizer. (c) Empirical formulae are derived from the film thickness-atomization characteristics, and atomization characteristics are summarized, proposing a mean droplet diameter nomogram widely applicable to a swirl atomizer.

  17. Surface modification of polyimide (PI) film using water cathode atmospheric pressure glow discharge plasma

    NASA Astrophysics Data System (ADS)

    Zheng, Peichao; Liu, Keming; Wang, Jinmei; Dai, Yu; Yu, Bin; Zhou, Xianju; Hao, Honggang; Luo, Yuan

    2012-10-01

    The industrial use of polyimide film is limited because of undesirable properties such as poor wettability. In the present paper, a new kind of equipment called water cathode atmospheric pressure glow discharge was used to improve the surface properties of polyimide films and made them useful to technical applications. The changes in hydrophilicity of modified polyimide film surfaces were investigated by contact angle, surface energy and water content measurements as a function of treatment time. The results obtained show good treatment homogeneity and that the variation trends of contact angles are different for polar and non-polar testing liquids, while surface energy and water content are significantly enhanced with the increase of treatment time until they achieve saturated values after 60 s plasma treatment. Also, the thickness of liquid layer plays an important role in plasma processing and directly affects the treatment effect. Changes in morphology of polyimide films were analyzed by atomic force microscope and the results indicate that surface hydrophilicity after plasma treatment are improved partly due to the increase in the roughness. In addition, polyimide films treated by plasma are subjected to an ageing process to determine the durability of plasma treatment. It is found that the hydrophilicity is still better than untreated ones though the hydrophobic character partly recovers after long-term storage in ambient air.

  18. Removal of cyanobacteria from synthetic and real water by dielectric barrier discharge process.

    PubMed

    Zhang, Yi; Chew, Stephanie Ting Yu; Te, Shu Harn; Lim, Tuti Mariana

    2015-12-01

    The feasibility of cyanobacteria removal from freshwater by a dielectric barrier discharge (DBD) process is investigated. Seven commercial and environmental cyanobacteria strains, as well as real algae-laden water, were tested. The removal of the cyanobacteria was evaluated by analyzing the changes in chlorophyll a content, total organic carbon (TOC) concentration, and cell morphology. Nearly total removal of chlorophyll a was achieved within 20 min, while the TOC analysis exhibited an increase-decrease-increase trend in 60 min of treatment, likely due to the oxidation of intracellular and intercellular materials. Observation under light microscopy revealed the disruption of intracellular and intercellular structures within 5 min of DBD treatment and thus supported the TOC analysis. Increasing the salinity of the medium from 0 to 5 parts per thousand (ppt) improved treatment efficiency, where similar level of chlorophyll a removal (around 93%) was achieved in only half the treatment time. Application of DBD on real algae-laden water from a fish farm yielded higher treatment efficiency than in synthetic medium, indicating the promising application of DBD as a means to control cyanobacteria bloom in fresh and estuary water bodies. PMID:26213133

  19. High explosives vapor detection by atmospheric sampling glow discharge ionization/tandem mass spectrometry

    SciTech Connect

    McLuckey, S.A.; Goeringer, D.E.; Asano, K.G.

    1996-02-01

    The combination of atmospheric sampling glow discharge ionization with tandem mass spectrometry for the detection of traces of high explosives is described. Particular emphasis is placed on use of the quadrupole ion trap as the type of tandem mass spectrometer. Atmospheric sampling glow discharge provides a simple, rugged, and efficient means for anion formation while the quadrupole ion trap provides for efficient tandem mass spectrometry. Mass selective ion accumulation and non-specific ion activation methods can be used to overcome deleterious effects arising from ion/ion interactions. Such interactions constitute the major potential technical barrier to the use of the ion trap for real-time monitoring of targeted compounds in uncontrolled and highly variable matrices. Tailored waveforms can be used to effect both mass selective ion accumulation and ion activation. Concatenated tailored waveforms allow for both functions in a single experiment thereby providing the capability for monitoring several targeted species simultaneously. The combination of atmospheric sampling glow discharge ionization with a state-of-the-art analytical quadrupole ion trap is a highly sensitive and specific detector for traces of high explosives. The combination is also small and inexpensive relative to virtually any other form of tandem mass spectrometry. The science and technology underlying the glow discharge/ion trap combination is sufficiently mature to form the basis for an engineering effort to make the detector portable. 85 refs.

  20. PIC-MCC Simulations of Capacitive High-Frequency Discharge Dynamics with Nanoparticles

    NASA Astrophysics Data System (ADS)

    Schweigert, Irina V.

    A new combined particle-in-cell Monte Carlo collision (PIC-MCC) approach is discussed for accurate and fast simulation of a radio-frequency (rf) discharge at a low gas pressure and high plasma density. Test calculations of the heating mode transition in a capacitively coupled rf-discharge in helium and argon show a good agreement with experimental data. The combined PIC-MCC algorithm is very efficient, especially for the collisionless regime of electron heating. Using this algorithm, the properties of a capacitively coupled 13.56 MHz discharge are studied in a mixture of Ar/C2H2 with nanoparticles of different sizes. For the description of plasma-dust interaction a kinetic model is introduced. The dust surface potential and discharge parameters are calculated self-consistently. In this model, any assumption about electron and ion energy distribution functions is not used. This allows us to calculate accurately the dust particle charging. The transport of dust is calculated by using the fluid approach. It is shown that at the initial stage of the growth, nanoparticles are accumulated near the sheath-plasma boundaries, where the ionization rate has maximum value. The nanoparticles suppress the ionization due to the absorbing of fast electrons and stimulate a quick change of the plasma parameters followed by the transition between different modes of discharge operation.

  1. The effects of irrigation waste-water disposal in a former discharge zone of the Murray Basin, Australia

    NASA Astrophysics Data System (ADS)

    Chambers, L. A.; Williams, B. G.; Barnes, C. J.; Wasson, R. J.

    1992-08-01

    In the Murray Basin in southeastern Australia, saline waste irrigation waters are often discharged to natural depressions and saline lakes as a salinity and land management strategy. At the Noora disposal basin in South Australia the waste irrigation water ( EC = 17-19 dS m-1) has formed a lens in the top of the highly saline (50-80 dS m -1) regional groundwater (Parilla Sands) aquifer. Using salinity and environmental isotopes of water (deuterium and oxygen-18) the lens has been shown to extend about 500 m in a northwesterly direction from the disposal pond. The major effects of this lens have been: (1) to cause upwards displacement of the regional ground water over an area of about 285 km 2, implying increased evaporation from areas surrounding the lens; (2) to reduce evaporation of regional ground water from the central low-lying area. Electromagnetic induction techniques for detecting preferred flowpaths away from the basin were rendered ineffective in this environment because of lithologic variations within the dune system. However, examination of bore-logs and groundwater gradients indicated that there was little evidence of stratigraphic control of mound development. Salinity in the Parilla Sands aquifer was closely related to the depth of the water table from the soil surface. Shallow (2-4 m) water tables were affected by recharge and evaporation to a much greater extent than ground water located below the higher dunes. There was, however, an almost instantaneous pressure response throughout the whole groundwater system to changes induced in the low-lying areas. Analyses of piezometric data showed that there was a seasonal variation imposed on the groundwater mound development. Corrected mean annual water-table increments and estimates of the mound volume and area were derived from a Theis response curve of the water table rise associated with the mound alone. Calculations using fitted parameters from the Theis analyses also suggested high transmissivity

  2. Trace elements in the Mississippi River Delta outflow region: Behavior at high discharge

    NASA Astrophysics Data System (ADS)

    Shiller, Alan M.; Boyle, Edward A.

    1991-11-01

    Samples for dissolved trace element analysis were collected in surface waters of the plume of the Mississippi River during a period of high river discharge. These field data are compared with results of laboratory mixing experiments. The studies show that Cu, Ni, and Mo are largely unreactive in the plume. Surprisingly, Fe also appears to show little reactivity; the pronounced flocculation removal of Fe frequently observed in other estuaries is not seen in this system. This difference may be a consequence of the alkaline nature of the Mississippi which results in low dissolved Fe concentrations in the river (<50 nmol/kg). Zinc, another particle-reactive element, also shows little reactivity. This lack of reactivity for Zn, as well as Cu and Ni, is partly a result of the short residence time of plume waters in shallow areas affected by sedimentary interactions. The chromium distribution shows apparent non-conservative behavior indicative of estuarine removal; however, temporal variation in river concentrations is a more likely explanation for this behavior. For some other elements, complex distributions occur as a consequence of the interplay of physical-chemical and/or biological processes with the dynamic mixing regime. For Cd, desorption from the suspended load plays a major role in determining the distribution. However, sedimentary input may also play a role in the spatial variability of Cd. For V, biological uptake in the plume exerts a strong influence on its distribution. At the time of this study, uptake was large enough to consume both the river flux of V as well as a substantial amount of vanadium supplied by the ocean.

  3. Dynamics of multiple double layers in high pressure glow discharge in a simple torus

    SciTech Connect

    Kumar Paul, Manash; Sharma, P. K.; Thakur, A.; Kulkarni, S. V.; Bora, D.

    2014-06-15

    Parametric characterization of multiple double layers is done during high pressure glow discharge in a toroidal vessel of small aspect ratio. Although glow discharge (without magnetic field) is known to be independent of device geometry, but the toroidal boundary conditions are conducive to plasma growth and eventually the plasma occupy the toroidal volume partially. At higher anode potential, the visibly glowing spots on the body of spatially extended anode transform into multiple intensely luminous spherical plasma blob structures attached to the tip of the positive electrode. Dynamics of multiple double layers are observed in argon glow discharge plasma in presence of toroidal magnetic field. The radial profiles of plasma parameters measured at various toroidal locations show signatures of double layer formation in our system. Parametric dependence of double layer dynamics in presence of toroidal magnetic field is presented here.

  4. Discharge chamber of high-current ion source with cold hollow cathode

    SciTech Connect

    Glazunov, V.N.; Grechanyi, V.G.; Metel', A.S.

    1988-08-01

    The discharge chamber of a high-current ion source with a sectional cold hollow cathode of conical shape formed by 44 coaxial rings and an emission grid is described. For a relative loss aperture of approx. = 1% of the fast oscillating electrons from the cavity, the discharge voltage does not exceed 500 V for currents of up to 200 A and helium or argon pressures of less than or equal to 10/sup -1/ Pa. Stable conditions are obtained with ion-extraction factors of up to 13% and a nonuniformity of ion-current density of approx. = 10% in the central zone of a grid with a diameter of up to 20 cm for a discharge current of 200 A and a pulse duration of up to 1 msec.

  5. Current tufa sedimentation in a high discharge river: A comparison with other synchronous tufa records in the Iberian Range (Spain)

    NASA Astrophysics Data System (ADS)

    Arenas, C.; Auqué, L.; Osácar, C.; Sancho, C.; Lozano, M. V.; Vázquez-Urbez, M.; Pardo, G.

    2015-07-01

    water depth. Certain high-discharge events were recorded as lower deposition rates concurrent in the three rivers. Moreover, anomalous water temperatures calculated from the calcite δ18O in the three rivers for a coincident time span support a regional anomaly in the precipitation δ18O. Thus, the evolution of the short-term tufa deposition rates and calcite δ18O composition through time can detect regional climate and hydrology changes and therefore can be robust criteria for correlation in the geological record.

  6. Radio-frequency powered glow discharge device and method with high voltage interface

    DOEpatents

    Duckworth, Douglas C.; Marcus, R. Kenneth; Donohue, David L.; Lewis, Trousdale A.

    1994-01-01

    A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.

  7. Radio-frequency powered glow discharge device and method with high voltage interface

    DOEpatents

    Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.

    1994-06-28

    A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.

  8. An annotated bibliography of selected references on the estimated rates of direct ground-water discharge to the Great Lakes

    USGS Publications Warehouse

    Grannemann, N.G.; Weaver, T.L.

    1999-01-01

    Estimated rates of direct ground-water discharge to Lake Michigan range from 800 to 6,700 cubic feet per second. Highest rates are calculated for the northeastern shore of the Lake. Using generalized values, total direct ground-water discharge to Lake Michigan was estimated to be about 2,700 cubic feet per second. Insufficient data are available to make similar estimates for the remaining Great Lakes (Huron, Superior, Erie, and Ontario), but estimated rates from six studies are much smaller than those from studies for Lake Michigan.

  9. Water withdrawals, wastewater discharge, and water consumption in the Apalachicola-Chattahoochee-Flint River Basin, 2005, and water-use trends, 1970-2005

    USGS Publications Warehouse

    Marella, Richard L.; Fanning, Julia L.

    2011-01-01

    In 2000, an estimated 49 percent of the water withdrawn for public supply in the basin was consumed, and the remaining 51 percent was returned to the hydrologic system through wastewater treatment systems. In 2005, an estimated 38 percent was consumed and 62 percent was returned to the hydrologic system. This contrast between water withdrawals and wastewater discharges for these years was caused primarily by below-average rainfall during 2000 (a dry year) and above-average rainfall during 2005 (a wet year).

  10. 33 CFR 155.330 - Oily mixture (bilge slops)/fuel oil tank ballast water discharges on U.S. non-oceangoing ships.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... oil tank ballast water discharges on U.S. non-oceangoing ships. 155.330 Section 155.330 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS...)/fuel oil tank ballast water discharges on U.S. non-oceangoing ships. (a) No person may operate a...

  11. 33 CFR 155.330 - Oily mixture (bilge slops)/fuel oil tank ballast water discharges on U.S. non-oceangoing ships.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... oil tank ballast water discharges on U.S. non-oceangoing ships. 155.330 Section 155.330 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS...)/fuel oil tank ballast water discharges on U.S. non-oceangoing ships. (a) No person may operate a...

  12. 33 CFR 155.330 - Oily mixture (bilge slops)/fuel oil tank ballast water discharges on U.S. non-oceangoing ships.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... oil tank ballast water discharges on U.S. non-oceangoing ships. 155.330 Section 155.330 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS...)/fuel oil tank ballast water discharges on U.S. non-oceangoing ships. (a) No person may operate a...

  13. The effects of gaseous bubble composition and gap distance on the characteristics of nanosecond discharges in distilled water

    NASA Astrophysics Data System (ADS)

    Hamdan, Ahmad; Cha, Min Suk

    2016-06-01

    Electric discharge in liquids with bubbles can reduce the energy consumption, which increases treatment efficiency. We present an experimental study of nanosecond discharges in distilled water bubbled with the monoatomic gas argon and with the polyatomic gases methane, carbon dioxide, and propane. We monitor the time evolution of the voltage and current waveforms, and calculate the injected charges to characterize the discharge. We establish a relationship between the injected charges and the shape of the plasma by time-resolved imaging to find that increasing the size of the gap reduces the injected charges. Moreover, we determine the plasma characteristics, including electron density, excitation temperatures (for atoms and ions), and rotational temperature of the OH and C2 radicals found in the plasma. Our space- and time-averaged measurements allow us to propose a spatial distribution of the plasma that is helpful for understanding the plasma dynamics necessary to develop and optimize applications based on nanosecond discharges in bubbled liquids.

  14. Ecological risk screen for PAHs in sediments near two produced water discharges at coastal production platforms in the Gulf of Mexico

    SciTech Connect

    Holtzman, S.; Meinhold, A.F.; DePhillips, M.P.

    1995-12-01

    Preliminary screens for risks to biota, were done on PAHs in sediments associated with produced waters from platforms at Delacroix Island and at Bay de Chene, in open bays of the Louisiana coast. Sediment samples were taken in Spring 1993 at the discharge sites, along three transacts at Delacroix Island and along four transacts at Bay de Chene (at intervals of 100, 300, 500 and 1000 ft), and at two reference locations for each discharge site. A screen for deleterious effects on biota was done by comparing concentrations to the Effects Range-Median (ERM) and Effects Range-Low (ERL) criteria of Long et al. 1995. Only sediment samples from the discharge site at Bay de Chene exceeded ERM concentrations for either total PAH, or individual and total high molecular weight PAHS. The ERL criteria for total and individual PAH concentrations were exceeded at, and 100 m from the discharge at Delacroix Island. At Bay de Chene the ERL criteria for total and individual PAH concentrations were exceeded at the discharge, as well as at 100 and 300 m stations.

  15. Synoptic Multi-tracer Sensing for Mapping Groundwater-Surface Water Discharges and Estimating Reactive Nitrate Loading along a Gaining Lowland River

    NASA Astrophysics Data System (ADS)

    Pai, H.; Villamizar, S. R.; Harmon, T. C.

    2015-12-01

    Distributed groundwater (GW) discharges to surface water (GW-SW discharges) in river systems remain difficult to delineate across spatiotemporal scales yet are important to understand with respect to link land management practices to nonpoint source constituent loading. In this work, we develop and test a relatively low-cost strategy for watershed-scale mapping distributed GW-SW discharges for nitrate (NO3-) in a gaining lowland river. We employ ambient GW specific conductance (SC) and nitrate as tracers using a high-resolution longitudinal synoptic sensing along the lower Merced River (38 river km) in Central California. Using available GW SC, we first calibrate a simple distributed GW-SW discharge model (segment-by-segment mixing model) at 1-km resolution for 13 synoptic sampling events at upstream daily flows ranging from 1.3 to 31.6 m3s-1. We then apply the distributed discharge estimates to a similar distributed nitrate loading model, adding a first-order decay term representing shallow aquifer denitrification along the GW-SW flow path. Best-fitting model outcomes (RMSE = 0.06-0.98 mg L-1) were found when we censored GW nitrate data following below detection thresholds (typically 0.5 mg L-1 NO3-N). The range of reach-estimated dimensionless denitrification rate terms varied from 0 to 0.432, which is slightly lower than previous regional results (0.17-1.06), accounting for our reach travel time.

  16. Analysis of the Lithium Sulfur Dioxide System at ultra-high rate discharges

    NASA Astrophysics Data System (ADS)

    Holmes, R. W.; Dey, A. N.

    1981-02-01

    The major objective of this program was to study the effects of electrolytes in Li/SO2 cells, for use in high rate abusive discharge conditions. Five electrolytes were investigated based on previous differential thermal analysis (DTA) results. A standard type electrolyte using acetonitrile (AN) was included in the program for comparison. The work was performed at Duracell International Inc. using LO26SX cells made at the Lithium Systems Division in North Tarrytown, New York. The cells were filled and tested at the Laboratory for Physical Science in Burlington, Massachusetts. Two electrolytes, AN(standard) and AN/PC (90/10) were found satisfactory for use in high rate abuse discharge conditions. Cells with AN/AA (90/10) electrolyte were satisfactory when fresh but these cells evolved CO2 on storage at 55 C and 72 C which led to severe cell-leakage. The remaining electrolytes, AN/BL/DME (85/10/5), PC/DME (50/50) and BL/DME (50/50), were regarded unsatisfactory for use in Li/SO2 cells for high rate abusive discharge conditions. The use of copper foil as the anode substrate was studied in LO26SX cells filled with the standard AN electrolyte. These cells were effective in reducing the sharp voltage reversal during abusive forced discharge at 2.0A at -30 C. The abuse resistance of these cells was at least as good as that of the standard cells.

  17. Saving a life after discharge: CPR training for parents of high-risk children.

    PubMed

    Knight, Lynda J; Wintch, Stephanie; Nichols, Amy; Arnolde, Vickie; Schroeder, Alan R

    2013-01-01

    Pediatric patients with chronic disease are at risk for cardiopulmonary arrest (CPA). Outcomes of CPA are improved if prompt quality cardiopulmonary resuscitation (CPR) is performed. This study examined the efficacy of the CPR Anytime™ Kit as a standardized method of CPR discharge training to families of high-risk children. The kit was provided to parents of 117 high-risk pediatric patients prior to hospital discharge. A telephone survey was used at 1, 3, and 6 months to assess retention of CPR knowledge and skills, parental comfort levels with CPR, and kit dissemination to family members. A second survey was used 1 year after implementation of program to assess nursing satisfaction. CPR comfort levels were reported as confident, knowledge and skills were reported as moderate on follow-up telephone surveys. A total of 82% of subjects reviewed the video at least once after discharge, and 79% of subjects shared the kit with at least two other family members or friends. A total of 72 of 74 nurses (97% ) surveyed were either "satisfied" or "very satisfied" with the program. Provision of the CPR Anytime Kit™ to families of high-risk pediatric patients prior to discharge leads to sustained levels of CPR knowledge and confidence. PMID:23281634

  18. Hollow-cathode electrode for high-power, high-pressure discharge devices

    DOEpatents

    Chang, J.J.; Alger, T.W.

    1995-08-22

    Several different cold cathode configurations are disclosed for a gas discharge device each having a plurality of grooves of selected spacing, depth and width to improve the emission of electrons in a gas discharge device. Each of the cold cathode configurations can be machined from a single piece of a selected material. Several of the configurations can be assembled with individual elements which is easily seen from the various figures. 8 figs.

  19. Water-elevation, stream-discharge, and ground-water quality data in the Alaska Railroad Industrial Area, Fairbanks, Alaska, May 1993 to May 1995

    USGS Publications Warehouse

    Kriegler, A.T.; Lilly, M.R.

    1995-01-01

    From May 1993 to May 1995, the U.S. Geological Survey in cooperation with the Alaska Department of Natural Resources, Division of Mining and Water Management collected data on ground-water and surface-water elevations, stream discharge, and ground-water quality in the Alaska Railroad Industrial area in Fairbanks, Alaska. The data- collection efforts were coordinated with environmental efforts being made in the study area by the Alaska Railroad Corporation. These data were collected as part of an effort to characterize the hydrogeology of the Alaska Railroad Industrial area and to define the extent of petroleum hydrocarbons in the area. Ground-water data were collected at 52 observation wells, surface-water data at 12 sites, stream discharge data at 9 sites, and chemical water-quality data at 32 observation wells.

  20. Effects of coal-bed methane discharge waters on the vegetation and soil ecosystem in Powder River Basin, Wyoming

    USGS Publications Warehouse

    Stearns, M.; Tindall, J.A.; Cronin, G.; Friedel, M.J.; Bergquist, E.

    2005-01-01

    Coal-bed methane (CBM) co-produced discharge waters in the Powder River Basin of Wyoming, resulting from extraction of methane from coal seams, have become a priority for chemical, hydrological and biological research during the last few years. Soil and vegetation samples were taken from affected and reference sites (upland elevations and wetted gully) in Juniper Draw to investigate the effects of CBM discharge waters on soil physical and chemical properties and on native and introduced vegetation density and diversity. Results indicate an increase of salinity and sodicity within local soil ecosystems at sites directly exposed to CBM discharge waters. Elevated concentrations of sodium in the soil are correlated with consistent exposure to CBM waters. Clay-loam soils in the study area have a much larger specific surface area than the sandy soils and facilitate a greater sodium adsorption. However, there was no significant relation between increasing water sodium adsorption ratio (SAR) values and increasing sediment SAR values downstream; however, soils exposed to the CBM water ranged from the moderate to severe SAR hazard index. Native vegetation species density was highest at the reference (upland and gully) and CBM affected upland sites. The affected gully had the greatest percent composition of introduced vegetation species. Salt-tolerant species had the greatest richness at the affected gully, implying a potential threat of invasion and competition to established native vegetation. These findings suggest that CBM waters could affect agricultural production operations and long-term water quality. ?? Springer 2005.

  1. Meteorological, stream-discharge, and water-quality data for 1986 through 1991 from two small basins in central Nevada

    SciTech Connect

    McKinley, P.W.; Oliver, T.A.

    1994-04-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, is investigating the volcanic tuffs of Yucca Mountain, Nevada, for their suitability as storage sites for nuclear waste. Two small basins, measuring less than 2 square miles, were studied to determine the volume of precipitation available for recharge to the ground water. The semiarid 3 Springs Basin is located to the east of Kawich Peak in the Kawich Range east of Tonopah, Nevada. Stewart Basin is a subalpine drainage basin north of Arc Dome in the Toiyabe Range north of Tonopah, Nevada. This publication presents the meteorological, stream-discharge, and water-quality data collected during the study. Meteorological data collected include air temperature, soil temperature, solar radiation, and relative humidity. Stream-discharge data were collected from the surface-water outlet of each basin. Water-quality data are chemical analyses of water samples collected from surface- and ground-water sources. Data were collected throughout the two basins. Each basin has a meteorological station located in the lower and upper reaches of the basin. Hydrologic records include stream-discharge and water-quality data from the lower meteorological site and water-quality data from springs within the basins. Meteorological data are available from the lower sites from the winter of 1986 through the fall of 1991. Periods of data collection were shorter for additional sites in the basin.

  2. Mass spectrometric investigation of the ionic species in a dielectric barrier discharge operating in helium-water vapour mixtures

    NASA Astrophysics Data System (ADS)

    Abd-Allah, Z.; Sawtell, D. A. G.; McKay, K.; West, G. T.; Kelly, P. J.; Bradley, J. W.

    2015-03-01

    Using advanced mass spectrometry the chemistry of ionic species present in an atmospheric-pressure parallel plate dielectric barrier discharge (DBD) with a single dielectric on the powered electrode have been identified. The discharge was driven in helium with controllable concentrations of water vapour using an excitation frequency of 10 kHz and an applied voltage of 1.2 kV. Both negative and positive ions were identified and their relative intensity determined with variation of water concentration in the discharge, inter-electrode spacing, gas residence time and nominal applied power. The most abundant negative ions were of the family \\text{O}{{\\text{H}}-}{{≤ft({{\\text{H}}2}\\text{O}\\right)}n} , while the positive ions were dominated by those of the form {{{H}}^ + }{{{(}}{{{H}}_2}{{O)}}_n} , with n up to 9 in both cases. Negative and positive ions responded in a similar way to changes in the operating parameters, with the particular response depending on the ion mass. Increasing the inter-electrode spacing and the water concentration in the discharge led to an increase in the intensity of large mass ionic water clusters. However, increasing the residence time of the species in the plasma region and increasing the applied power resulted in fragmentation of large water clusters to produce smaller ions.

  3. Nanosecond Pulsed Discharge in Water without Bubbles: A Fundamental Study of Initiation, Propagation and Plasma Characteristics

    NASA Astrophysics Data System (ADS)

    Seepersad, Yohan

    research. Finally, analysis of emission spectra obtained from the OH(A-X) band at 308 nm by the excited hydroxyl radical was performed to quantify the temperature parameters of the plasma. Boltzmann analysis was performed to quantify the rotational temperature of OH which correlates well to the liquid temperature, and Stark broadening of the ionic lines belonging to hydrogen and oxygen was analysed to estimate electron temperature. It was found that the liquid temperature remained close to bulk temperature with T_(n,i)<500 K, and that the electron temperature was very high Te˜6-10 eV. Finally, based on the characterization of the plasma parameters, several potential avenues for applications of this regime of plasma will be suggested. The complex physical and chemical dynamics established when plasma is generated within a liquid medium has unlocked new and fascinating possibilities in the areas of biomedicine, water treatment, material synthesis and nanoscience. The high density, low temperature plasma formed could potentially be harnessed to unlock new applications across these fields and more.

  4. Synoptic Discharge, Water-Property, and pH Measurements for Muddy River Springs Area and Muddy River, Nevada, February 7, 2001

    USGS Publications Warehouse

    Beck, David A.; Wilson, Jon W.

    2006-01-01

    On February 7, 2001, synoptic discharge measurements at selected sites along the Muddy River in Nevada, indicated three trends in discharge resulting from contributions of spring discharge, influences of diversionary flow, and contributions from shallow ground water. Effects from diversionary and tributary flow were local in nature and resulted in a net gain of 2.6 cubic feet per second throughout the measured reach. The minor increase in discharge may be the result of contributions from ground-water flow and measurement error. Comparison of 1963 and 2001 discharge measurements within the Muddy River Springs area indicated that discharge rates and trends from these source waters were similar. Along the mainstem of the Muddy River, water-temperature measurements indicated a net decrease of 8.8 degrees Celsius. Water samples collected and analyzed for specific conductance indicated a net increase of 390 microsiemens per centimeter at 25 degrees Celsius, whereas pH measurements remained relatively constant.

  5. Modeling the Effects of Climate Change on Water, Sediment, and Nutrient Discharge from the Maumee River Watershed

    NASA Astrophysics Data System (ADS)

    Cousino, L. K.; Becker, R.; Zmijewski, K. A.

    2013-12-01

    A hydrologic model of the Maumee River watershed in NW Ohio, USA was constructed to test the effects of climate change on water flow and sediment and nutrient loading within the drainage basin. The Maumee River drains a larger area (17,100 km2) than any other watershed in the Great Lakes region before discharging into the Western Basin (WB) of Lake Erie. Approximately 70% of the land within the watershed is agricultural, resulting in excess sediment and nutrient loading in the WB. High nutrient concentrations, especially phosphate concentrations, contribute to harmful algal blooms (HABs) in Lake Erie, which is the source of drinking water for approximately 11 million people. After a decrease in Lake Erie HABs in the late 1980s and early 1990s, toxic cyanobacteria blooms have been prevalent in the WB every summer since 1995. To determine the effects of climate change on streamflow and sediment and nutrient loading in the Maumee River watershed, a Soil and Water Assessment Tool (SWAT) hydrologic model was constructed. Flow and suspended sediment calibrations were performed for 1995-1999 using observed data from four USGS gauging stations. Suspended sediment concentration, which correlates highly with total phosphorus concentration, was used as a proxy for total phosphorus loads. Downscaled climate projections from the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) were inputted into the model to test the effects of climate change on the flow and suspended sediment discharge of the Maumee River. Validation was performed by inputting downscaled climate data for 1975-1999 and comparing the output to observed flow and suspended sediment data from the USGS gauging station at Waterville, Ohio. Model outputs for A1B, A2, and B1 climate scenarios indicate an overall decrease in annual flow over the next century, with higher flow in the winter and spring and lower total flow in the summer. However, model outputs also indicate

  6. Ground-water discharge determined from measurements of evapotranspiration, other available hydrologic components, and shallow water-level changes, Oasis Valley, Nye County, Nevada

    USGS Publications Warehouse

    Reiner, S.R.; Laczniak, R.J.; DeMeo, G.A.; Smith, Jody L.; Elliott, P.E.; Nylund, W.E.; Fridrich, C.J.

    2002-01-01

    Oasis Valley is an area of natural ground-water discharge within the Death Valley regional ground-water flow system of southern Nevada and adjacent California. Ground water discharging at Oasis Valley is replenished from inflow derived from an extensive recharge area that includes the northwestern part of the Nevada Test Site (NTS). Because nuclear testing has introduced radionuclides into the subsurface of the NTS, the U.S. Department of Energy currently is investigating the potential transport of these radionuclides by ground water flow. To better evaluate any potential risk associated with these test-generated contaminants, a number of studies were undertaken to accurately quantify discharge from areas downgradient in the regional ground-water flow system from the NTS. This report refines the estimate of ground-water discharge from Oasis Valley. Ground-water discharge from Oasis Valley was estimated by quantifying evapotranspiration (ET), estimating subsurface outflow, and compiling ground-water withdrawal data. ET was quantified by identifying areas of ongoing ground-water ET, delineating areas of ET defined on the basis of similarities in vegetation and soil-moisture conditions, and computing ET rates for each of the delineated areas. A classification technique using spectral-reflectance characteristics determined from satellite imagery acquired in 1992 identified eight unique areas of ground-water ET. These areas encompass about 3,426 acres of sparsely to densely vegetated grassland, shrubland, wetland, and open water. Annual ET rates in Oasis Valley were computed with energy-budget methods using micrometeorological data collected at five sites. ET rates range from 0.6 foot per year in a sparse, dry saltgrass environment to 3.1 feet per year in dense meadow vegetation. Mean annual ET from Oasis Valley is estimated to be about 7,800 acre-feet. Mean annual ground-water discharge by ET from Oasis Valley, determined by removing the annual local precipitation

  7. Ultra-High-Pressure Water

    NASA Astrophysics Data System (ADS)

    French, Martin; Redmer, Ronald; Mattsson, Thomas R.

    2008-03-01

    We present the first all-electron QMD simulations of water in the ultra-high-pressure regime up to conditions typical for the deep interior of Jupiter and Saturn. We calculate the equation of state and the Hugoniot curve and study the structural properties via pair correlation functions and self-diffusion coefficients. In the ultra-dense superionic phase, we find a continuous transition in the protonic structure. Water at conditions of Jupiter's core (i.e. 20000 K, 50 Mbar, 11 g/cm^3) forms a fluid dense plasma. Supported by the DFG within SFB 652. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States DOE's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  8. Application of ICP-OES for evaluating energy extraction and production wastewater discharge impacts on surface waters in Western Pennsylvania.

    PubMed

    Pancras, Joseph Patrick; Norris, Gary A; Landis, Matthew S; Kovalcik, Kasey D; McGee, John K; Kamal, Ali S

    2015-10-01

    Oil and gas extraction and coal-fired electrical power generating stations produce wastewaters that are treated and discharged to rivers in Western Pennsylvania with public drinking water system (PDWS) intakes. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to quantify inorganic species in wastewater and river samples using a method based on EPA Method 200.7 rev4.4. A total of 53 emission lines from 30 elements (Al, As, B, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn) were investigated. Samples were prepared by microwave-assisted acid digestion using a mixture of 2% HNO3 and 0.5% HCl. Lower interferences and better detection characteristics resulted in selection of alternative wavelengths for Al, As, Sb, Mg, Mo, and Na. Radial view measurements offered accurate determinations of Al, Ba, K, Li, Na, and Sr in high-brine samples. Spike recovery studies and analyses of reference materials showed 80-105% recoveries for most analytes. This method was used to quantify species in samples with high to low brine concentrations with method detection limits a factor of 2 below the maximum contaminant limit concentrations of national drinking water standards. Elements B, Ca, K, Li, Mg, Na, and Sr were identified as potential tracers for the sources impacting PDWS intakes. Usability of the ICP-OES derived data for factor analytic model applications was also demonstrated. PMID:26005746

  9. Destruction of 4-phenolsulfonic acid in water by anodic contact glow discharge electrolysis.

    PubMed

    Yang, Haiming; An, Baigang; Wang, Shaoyan; Li, Lixiang; Jin, Wenjie; Li, Lihua

    2013-06-01

    Destruction of 4-phenolsulfonic acid (4-PSA) in water was carried out using anodic contact glow discharge electrolysis. Accompanying the decay of 4-PSA, the amount of total organic carbon (TOC) in water correspondingly decreased, while the sulfonate group of 4-PSA was released as sulfate ion. Oxalate and formate were obtained as minor by-products. Additionally, phenol, 1,4-hydroquinone, hydroxyquinol and 1,4-benzoquinone were detected as primary intermediates in the initial stages of decomposition of 4-PSA. A reaction pathway involving successive attacks of hydroxyl and hydrogen radicals was assumed on the basis of the observed products and kinetics. It was revealed that the decay of both 4-PSA and TOC obeyed a first-order rate law. The effects of different Fe ions and initial concentrations of 4-PSA on the degradation rate were investigated. It was found that the presence of Fe ions could increase the degradation rate of 4-PSA, while initial concentrations lower than 80 mmol/L had no significant effect on kinetic behaviour. The disappearance rate of 4-PSA was significantly affected by pH. PMID:24191593

  10. Removal of cyanide from water by means of plasma discharge technology.

    PubMed

    Hijosa-Valsero, María; Molina, Ricardo; Schikora, Hendrik; Müller, Michael; Bayona, Josep M

    2013-03-15

    Two different nonthermal plasma reactors at atmospheric pressure were assessed for the first time for cyanide removal (1 mg L(-1)) from aqueous solutions (0.025 M NaHCO(3)/NaOH buffer, pH 11) at laboratory scale. Both devices were dielectric barrier discharge (DBD) reactors; one of them was a conventional batch reactor (R1) and the other one was a coaxial thin falling water film reactor (R2). A first-order degradation kinetics was proposed for both experiments, obtaining k(R1) = 0.5553 min(-1) and k(R2) = 0.7482 min(-1). The coaxial reactor R2 yielded a removal of 99% within only 3 min. Energy efficiencies (G) were calculated, yielding 1.74 mg kW(-1) h(-1) for R1 and 127.9 mg kW(-1) h(-1) for R2. When the treatment was applied to industrial wastewaters, cyanide elimination was confirmed, although at a lower rate (above 92% removal in 90 min with R2). Therefore, plasma reactors could be a relevant alternative to established advanced oxidation techniques (UV, H(2)O(2), ozonation, etc.) for the removal of cyanide from wastewaters with low organic loads or even drinking waters. PMID:23332789

  11. Chlorothalonil and 2,4-D losses in surface water discharge from a managed turf watershed.

    PubMed

    King, K W; Balogh, J C

    2010-08-01

    Managed turf sites (golf courses) are the most intensively managed landscapes in the urban environment. Yet, long-term watershed scale studies documenting the environmental transport of agrichemicals applied to these systems are rare. The objective of this study was to quantify the surface discharge losses of two commonly applied pesticides (chlorothalonil and 2,4-D) resulting from prevailing practices on a managed golf course. Inflow and outflow discharge waters on a subarea of Northland Country Club located in Duluth, MN were measured for both quantity and quality from April through November from 2003 to 2008. The median chlorothalonil outflow concentration (0.58 microg L(-1)) was significantly greater (p < 0.05) than the inflow concentration, which was below the detection limit (0.07 microg L(-1)). Similarly, the median outflow 2,4-D concentration (0.85 microg L(-1)) was significantly greater (p < 0.05) than the inflow concentration (0.31 microg L(-1)). Chlorothalonil concentrations occasionally exceeded acute toxicity levels (7.6 microg L(-1)) reported for rainbow trout. No 2,4-D concentrations exceeded any human or aquatic species published toxicity level; however, the maximum measured 2,4-D concentration (67.1 microg L(-1)), which rarely occurred, did approach the 70 microg L(-1) maximum contaminant level (MCL) for that compound. Losses of both pesticides were detectable throughout the annual sampling period. Mean annual chlorothalonil loading was 10.5 g ha(-1) or 0.3% of applied, while mean annual 2,4-D loading was 4.9 g ha(-1) or 0.5% of applied. The findings of this study provide quantifiable evidence of agrichemical transport resulting from typical turfgrass management and highlight the need for implementation of best management practices to combat the offsite transport of agrichemicals used in professional turf management. PMID:20526481

  12. Estimation of minimum 7-day, 2-year discharge for selected stream sites, and associated low-flow water-quality data, southeast Texas, 1997-98

    USGS Publications Warehouse

    East, Jeffery W.

    1999-01-01

    The U.S. Geological Survey (USGS) operates a network of streamflow-gaging stations in Texas that provides discharge data used for water-management decisions and various other purposes. Operating stations at all locations where discharge data are needed is not feasible, but the statistical characteristics of the network station data can be used to estimate discharge characteristics at ungaged sites. Regionalization techniques such as regression analyses relate discharge-frequency characteristics to selected physical and climatic characteristics of drainage basins. A particular discharge-frequency characteristic that can be regionalized is the minimum 7-day, 2-year discharge1 (7Q2). In Texas, the 7Q2 is used at stream sites to analyze permit applications for water allocation, water-supply planning, aquatic maintenance (instream flow) requirements, and waste-load allocation for point and nonpoint source discharges.

  13. Effect of river discharge and geometry on tides and net water transport in an estuarine network, an idealised model applied to the Yangtze Estuary

    NASA Astrophysics Data System (ADS)

    de Swart, Huib E.; Alebregtse, Niels C.

    2015-04-01

    Many estuaries in the world show a complex pattern of interconnected branches. The water motion in these estuarine networks is dominated by tides and by net water transport, the latter being primarily forced by river discharge and by nonlinear tidal rectification processes. The behaviour of tides (sea surface height and currents) and the distribution of net water transport over the branches is an important topic of research, e.g. for flushing of pollutants, salinity intrusion and sediment transport. Field observations, e.g. in the Yangtze Estuary, show that tides and distribution of net water transport over the branches are highly sensitive to river discharge (wet and dry season) and to changes in geometry, e.g. due to navigational works. To understand such sensivities, this contribution presents a semi-analytical model that yields explicit solutions for tides and net water transport for arbitrary tidal network configurations. The model accounts for tide-river interactions, which in particular affect friction, and for tidal rectification processes. The model is subsequently applied to the Yangtze Estuary. It will be shown that tide-river interactions are crucial to understand the observed differences in tidal propagation between the wet and dry season. Furthermore, the relative increase of the net water transport driven by tidal rectification with respect to that driven by river discharge explains the observed differences in distribution of water transport over the branches between wet and dry season in this estuary. Finally, it will be shown that the construction of navigational works resulted in an increase of tidal currents, a decrease of net water transport and an increase in ebb-dominance in the North Passage of the Yangtze Estuary, consistent with observations.

  14. A tidal creek water budget: Estimation of groundwater discharge and overland flow using hydrologic modeling in the Southern Everglades

    NASA Astrophysics Data System (ADS)

    Michot, Béatrice; Meselhe, Ehab A.; Rivera-Monroy, Victor H.; Coronado-Molina, Carlos; Twilley, Robert R.

    2011-07-01

    Taylor Slough is one of the natural freshwater contributors to Florida Bay through a network of microtidal creeks crossing the Everglades Mangrove Ecotone Region (EMER). The EMER ecological function is critical since it mediates freshwater and nutrient inputs and controls the water quality in Eastern Florida Bay. Furthermore, this region is vulnerable to changing hydrodynamics and nutrient loadings as a result of upstream freshwater management practices proposed by the Comprehensive Everglades Restoration Program (CERP), currently the largest wetland restoration project in the USA. Despite the hydrological importance of Taylor Slough in the water budget of Florida Bay, there are no fine scale (˜1 km 2) hydrodynamic models of this system that can be utilized as a tool to evaluate potential changes in water flow, salinity, and water quality. Taylor River is one of the major creeks draining Taylor Slough freshwater into Florida Bay. We performed a water budget analysis for the Taylor River area, based on long-term hydrologic data (1999-2007) and supplemented by hydrodynamic modeling using a MIKE FLOOD (DHI, http://dhigroup.com/) model to evaluate groundwater and overland water discharges. The seasonal hydrologic characteristics are very distinctive (average Taylor River wet vs. dry season outflow was 6 to 1 during 1999-2006) with a pronounced interannual variability of flow. The water budget shows a net dominance of through flow in the tidal mixing zone, while local precipitation and evapotranspiration play only a secondary role, at least in the wet season. During the dry season, the tidal flood reaches the upstream boundary of the study area during approximately 80 days per year on average. The groundwater field measurements indicate a mostly upwards-oriented leakage, which possibly equals the evapotranspiration term. The model results suggest a high importance of groundwater contribution to the water salinity in the EMER. The model performance is satisfactory

  15. Electric Discharge Sintering and Joining of Tungsten Carbide--Cobalt Composite with High-Speed Steel Substrate

    SciTech Connect

    Grigoryev, Evgeny G.

    2011-01-17

    Simultaneous electro discharge sintering of high strength structure of tungsten carbide-cobalt composite and connection it with high-speed steel substrate is investigated and suitable operating parameters are defined. Tungsten carbide-cobalt and high-speed steel joining was produced by the method of high voltage electrical discharge together with application of mechanical pressure to powder compact. It was found that the density and hardness of composite material reach its maximum values at certain magnitudes of applied pressure and high voltage electrical discharge parameters. We show that there is an upper level for the discharge voltage beyond which the powder of composite material disintegrates like an exploding wire. Due to our results it is possible to determine optimal parameters for simultaneous electro discharge sintering of WC-Co and bonding it with high-speed steel substrate.

  16. Electron emission mechanism during the nanosecond high-voltage pulsed discharge in pressurized air

    NASA Astrophysics Data System (ADS)

    Levko, D.; Yatom, S.; Vekselman, V.; Krasik, Ya. E.

    2012-02-01

    A comparison between the results of x-ray absorption spectroscopy of runaway electrons (RAEs) generated during nanosecond timescale high-voltage (HV) gas discharge and the simulated attenuation of the x-ray flux produced by the runaway electron spectrum calculated using particle-in-cell numerical modeling of such a type of discharge is presented. The particle-in-cell simulation considered the field and explosive emissions (EEs) of the electrons from the cathode. It is shown that the field emission is the dominant emission mechanism for the short-duration (<2.5 ns) high-voltage pulses, while for the long-duration (>5 ns) high-voltage pulses, the explosive emission is likely to play a significant role.

  17. Effect of Coulomb scattering on low-pressure high-density electronegative discharges.

    PubMed

    Kawamura, E; Birdsall, C K

    2005-02-01

    For electronegative plasmas with low gas pressure and high ion densities, we expect Coulomb collisions between positive and negative ions to dominate over collisions between ions and neutrals. We incorporated Nanbu's cumulative small-angle collision method [K. Nanbu, Phys. Rev. E, 55, 4642 (1997)] into our one-dimensional three-velocity-component particle-in-cell code PDP1 in order to study the effect of Coulomb collisions on low pressure high density electronegative discharges. Nanbu's method treats a succession of small-angle binary collisions as a single binary collision with a large scattering angle, which is far faster than treating each individual small-angle collision. We find that Coulomb collisions between positive and negative ions in low-pressure high-density electronegative discharges significantly modify the negative ion flux, density, and kinetic energy profiles. PMID:15783425

  18. Effect of Coulomb scattering on low-pressure high-density electronegative discharges

    SciTech Connect

    Kawamura, E.; Birdsall, C.K.

    2005-02-01

    For electronegative plasmas with low gas pressure and high ion densities, we expect Coulomb collisions between positive and negative ions to dominate over collisions between ions and neutrals. We incorporated Nanbu's cumulative small-angle collision method [K. Nanbu, Phys. Rev. E, 55, 4642 (1997)] into our one-dimensional three-velocity-component particle-in-cell code PDP1 in order to study the effect of Coulomb collisions on low pressure high density electronegative discharges. Nanbu's method treats a succession of small-angle binary collisions as a single binary collision with a large scattering angle, which is far faster than treating each individual small-angle collision. We find that Coulomb collisions between positive and negative ions in low-pressure high-density electronegative discharges significantly modify the negative ion flux, density, and kinetic energy profiles.

  19. Compact high-speed reciprocating probe system for measurements in a Hall thruster discharge and plume.

    PubMed

    Dannenmayer, K; Mazouffre, S

    2012-12-01

    A compact high-speed reciprocating probe system has been developed in order to perform measurements of the plasma parameters by means of electrostatic probes in the discharge and the plume of a Hall thruster. The system is based on a piezoelectric linear drive that can achieve a speed of up to 350 mm/s over a travel range of 90 mm. Due to the high velocity of the linear drive the probe can be rapidly moved in and out the measurement region in order to minimize perturbation of the thruster discharge due to sputtering of probe material. To demonstrate the impact of the new system, a heated emissive probe, installed on the high-speed translation stage, was used to measure the plasma potential and the electron temperature in the near-field plume of a low power Hall thruster. PMID:23277983

  20. Compact high-speed reciprocating probe system for measurements in a Hall thruster discharge and plume

    SciTech Connect

    Dannenmayer, K.; Mazouffre, S.

    2012-12-15

    A compact high-speed reciprocating probe system has been developed in order to perform measurements of the plasma parameters by means of electrostatic probes in the discharge and the plume of a Hall thruster. The system is based on a piezoelectric linear drive that can achieve a speed of up to 350 mm/s over a travel range of 90 mm. Due to the high velocity of the linear drive the probe can be rapidly moved in and out the measurement region in order to minimize perturbation of the thruster discharge due to sputtering of probe material. To demonstrate the impact of the new system, a heated emissive probe, installed on the high-speed translation stage, was used to measure the plasma potential and the electron temperature in the near-field plume of a low power Hall thruster.