WorldWideScience

Sample records for surface waters discharge

  1. Surface water discharges from onshore stripper wells.

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ruma,; Yoshihara, K. [Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555 (Japan); Hosseini, S. H. R., E-mail: hosseini@kumamoto-u.ac.jp; Sakugawa, T.; Akiyama, H. [Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555 (Japan); Institute of Pulsed Power Science, Kumamoto University, Kumamoto 860-8555 (Japan); Akiyama, M. [Department of Electrical and Electronic Engineering, Kagoshima University, Kagoshima 890-0065 (Japan); Lukeš, P. [Institute of Plasma Physics, AS CR, Prague, Prague 18200 (Czech Republic)

    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.

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

    Science.gov (United States)

    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.

  4. Characteristics of meter-scale surface electrical discharge propagating along water surface at atmospheric pressure

    Science.gov (United States)

    Hoffer, Petr; Sugiyama, Yuki; Hosseini, S. Hamid R.; Akiyama, Hidenori; Lukes, Petr; Akiyama, Masahiro

    2016-10-01

    This paper reports physical characteristics of water surface discharges. Discharges were produced by metal needle-to-water surface geometry, with the needle electrode driven by 47 kV (FWHM) positive voltage pulses of 2 µs duration. Propagation of discharges along the water surface was confined between glass plates with 2 mm separation. This allowed generation of highly reproducible 634 mm-long plasma filaments. Experiments were performed using different atmospheres: air, N2, and O2, each at atmospheric pressure. Time- and spatially-resolved spectroscopic measurements revealed that early spectra of discharges in air and nitrogen atmospheres were dominated by N2 2nd positive system. N2 radiation disappeared after approx. 150 ns, replaced by emissions from atomic hydrogen. Spectra of discharges in O2 atmosphere were dominated by emissions from atomic oxygen. Time- and spatially-resolved emission spectra were used to determine temperatures in plasma. Atomic hydrogen emissions showed excitation temperature of discharges in air to be about 2  ×  104 K. Electron number densities determined by Stark broadening of the hydrogen H β line reached a maximum value of ~1018 cm-3 just after plasma initiation. Electron number densities and temperatures depended only slightly on distance from needle electrode, indicating formation of high conductivity leader channels. Direct observation of discharges by high speed camera showed that the average leader head propagation speed was 412 km · s-1, which is substantially higher value than that observed in experiments with shorter streamers driven by lower voltages.

  5. Electron density and electron temperature measurements in nanosecond pulse discharges over liquid water surface

    Science.gov (United States)

    Simeni Simeni, M.; Roettgen, A.; Petrishchev, V.; Frederickson, K.; Adamovich, I. V.

    2016-12-01

    Time-resolved electron density, electron temperature, and gas temperature in nanosecond pulse discharges in helium and O2-He mixtures near liquid water surface are measured using Thomson/pure rotational Raman scattering, in two different geometries, (a) ‘diffuse filament’ discharge between a spherical high-voltage electrode and a grounded pin electrode placed in a reservoir filled with distilled water, with the tip exposed, and (b) dielectric barrier discharge between the high-voltage electrode and the liquid water surface. A diffuse plasma filament generated between the electrodes in helium during the primary discharge pulse exhibits noticeable constriction during the secondary discharge pulse several hundred ns later. Adding oxygen to the mixture reduces the plasma filament diameter and enhances constriction during the secondary pulse. In the dielectric barrier discharge, diffuse volumetric plasma occupies nearly the entire space between the high voltage electrode and the liquid surface, and extends radially along the surface. In the filament discharge in helium, adding water to the container results in considerable reduction of plasma lifetime compared to the discharge in dry helium, by about an order of magnitude, indicating rapid electron recombination with water cluster ions. Peak electron density during the pulse is also reduced, by about a factor of two, likely due to dissociative attachment to water vapor during the discharge pulse. These trends become more pronounced as oxygen is added to the mixture, which increases net rate of dissociative attachment. Gas temperature during the primary discharge pulse remains near room temperature, after which it increases up to T ~ 500 K over 5 µs and decays back to near room temperature before the next discharge pulse several tens of ms later. As expected, electron density and electron temperature in diffuse DBD plasmas are considerably lower compared to peak values in the filament discharge. Use of Thomson

  6. Point source nutrient discharges to surface water in the United States Pacific Northwest for 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial data set was created by the U.S. Geological Survey (USGS) to represent the amount of total nitrogen and total phosphorus discharged to surface waters in...

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Centner, Terence; Eberhart, Nicholas

    2014-05-08

    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.

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

    Directory of Open Access Journals (Sweden)

    Terence Centner

    2014-05-01

    Full Text Available 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.

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

    OpenAIRE

    Terence Centner; Nicholas Eberhart

    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 pesticid...

  13. Study on the Generation Characteristics of Dielectric Barrier Discharge Plasmas on Water Surface

    Science.gov (United States)

    Liu, Wenzheng; Li, Chuanhui

    2014-01-01

    A new contact glow discharge electrode on the surface of water was designed and employed in this study. Because of the strong field strength in the small air gap formed by the electrode and the water surface, glow discharge plasmas were generated and used to treat waste water. The electric field distribution of the designed electrode model was simulated by MAXWELL 3D® simulation software, and the discharge parameters were measured. Through a series of experiments, we investigated the impact of optimal designs, such as the dielectric of the electrode, immersion depths, and curvature radii of the electrode on the generation characteristics of plasmas. In addition, we designed an equipotential multi-electrode configuration to treat a Methyl Violet solution and observe the discoloration effect. The experimental and simulation results indicate that the designed electrodes can realize glow discharge with a relative low voltage, and the generated plasmas covered a large area and were in stable state. The efficiency of water treatment is improved and optimized with the designed electrodes.

  14. Evaluating the vulnerability of surface waters to antibiotic contamination from varying wastewater treatment plant discharges

    Energy Technology Data Exchange (ETDEWEB)

    Batt, Angela L. [Department of Chemistry, State University of New York at Buffalo, 608 Natural Sciences Complex, Buffalo, NY 14260-3000 (United States)]. E-mail: abatt@hotmail.com; Bruce, Ian B. [Department of Geography, Buffalo State College, Buffalo, NY (United States)]. E-mail: ianbbruce@gmail.com; Aga, Diana S. [Department of Chemistry, State University of New York at Buffalo, 608 Natural Sciences Complex, Buffalo, NY 14260-3000 (United States)]. E-mail: dianaaga@buffalo.edu

    2006-07-15

    Effluents from three wastewater treatment plants with varying wastewater treatment technologies and design were analyzed for six antibiotics and caffeine on three sampling occasions. Sulfamethoxazole, trimethoprim, ciprofloxacin, tetracycline, and clindamycin were detected in the effluents at concentrations ranging from 0.090 to 6.0 {mu}g/L. Caffeine was detected in all effluents at concentrations ranging from 0.19 to 9.9 {mu}g/L. These findings indicate that several conventional wastewater management practices are not effective in the complete removal of antibiotics, and their discharges have a large potential to affect the aquatic environment. To evaluate the persistence of antibiotics coming from the wastewater discharges on the surrounding surface waters, samples were collected from the receiving streams at 10-, 20- and 100-m intervals. Ciprofloxacin, sulfamethoxazole, and clindamycin (0.043 to 0.076 {mu}g/L) were found as far as 100 m from the discharge point, which indicates the persistence of these drugs in surface waters. - This work investigates the extent of antibiotic concentrations in receiving waters from discharges of wastewater treatment plants.

  15. Flow Alteration and Chemical Reduction: Air Stripping to Lessen Subsurface Discharges of Mercury to Surface Water

    Science.gov (United States)

    Brooks, S. C.; Bogle, M.; Liang, L.; Miller, C. L.; Peterson, M.; Southworth, G. R.; Spalding, B. P.

    2009-12-01

    Mercury concentrations in groundwater, surface water, and biota near an industrial facility in Oak Ridge, Tennessee remain high some 50 years after the original major releases from the facility to the environment. Since the mid-1980s, various remedial and abatement actions have been implemented at the facility, including re-routing water flows, armoring contaminated stream banks, relining or cleanout of facility storm drains, and activated charcoal treatment of groundwater and sump discharges. These actions were taken to reduce inorganic mercury inputs from the facility to the stream; a strategy that assumes limiting the inorganic mercury precursor will reduce Hg methylation and its subsequent bioaccumulation. To date, such actions have reduced mercury loading from the site by approximately 90% from levels typical of the mid 1980's, but waterborne mercury at the facility boundary remains roughly 100 times the typical local background concentration and methylmercury accumulation in aquatic biota exceed standards for safe consumption by humans and wildlife. In 2008 and 2009, a series of investigations was initiated to explore innovative approaches to further control mercury concentrations in stream water. Efforts in this study focused on decreasing waterborne inorganic mercury inputs from two sources. The first, a highly localized source, is the discharge point of the enclosed stormdrain network whereas the second is a more diffuse short reach of stream where metallic Hg in streambed sediments generates a continued input of dissolved Hg to the overlying water. Moving a clean water flow management discharge point to a position downstream of the contaminated reach reduced mercury loading from the streambed source by 75% - 100%, likely by minimizing resuspension of Hg-rich fine particulates and changing characteristic hyporheic flow path length and residence time. Mercury in the stormdrain discharge exists as highly reactive dissolved Hg(II) due to residual chlorine in

  16. Corona discharges with water electrospray for Escherichia coli biofilm eradication on a surface.

    Science.gov (United States)

    Kovalova, Zuzana; Leroy, Magali; Kirkpatrick, Michael J; Odic, Emmanuel; Machala, Zdenko

    2016-12-01

    Low-temperature plasma (cold), a new method for the decontamination of surfaces, can be an advantageous alternative to the traditional chemical methods, autoclave or dry heat. Positive and negative corona discharges in air were tested for the eradication of 48-h Escherichia coli biofilms grown on glass slides. The biofilms were treated by cold corona discharge plasma for various exposure times. Water electrospray from the high voltage electrode was applied in some experiments. Thermostatic cultivation of the biofilm, and confocal laser scanning microscopy (CLSM) of the biofilm stained with fluorescent dyes were used for biocidal efficiency quantification. Up to 5 log10 reduction of bacterial concentration in the biofilm was measured by thermostatic cultivation after exposure to both corona discharges for 15min. This decontamination efficiency was significantly enhanced by simultaneous water electrospray through the plasma. CLSM showed that the live/dead ratio after treatment remained almost constant inside the biofilm; only cells on the top layers of the biofilm were affected. DAPI fluorescence showed that biofilm thickness was reduced by about 1/3 upon exposure to the corona discharges with electrospray for 15min. The biofilm biomass loss by about 2/3 was confirmed by crystal violet assay.

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

    Institute of Scientific and Technical Information of China (English)

    Young Sun MOK; Hyun Tae AHN; Joeng Tai KIM

    2007-01-01

    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.

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

    Science.gov (United States)

    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.

  19. Continuous measurements of water surface height and width along a 6.5km river reach for discharge algorithm development

    Science.gov (United States)

    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.

  20. Noncontact methods for measuring water-surface elevations and velocities in rivers: Implications for depth and discharge extraction

    Science.gov (United States)

    Nelson, Jonathan M.; Kinzel, Paul J.; McDonald, Richard R.; Schmeeckle, Mark

    2016-01-01

    Recently developed optical and videographic methods for measuring water-surface properties in a noninvasive manner hold great promise for extracting river hydraulic and bathymetric information. This paper describes such a technique, concentrating on the method of infrared videog- raphy for measuring surface velocities and both acoustic (laboratory-based) and laser-scanning (field-based) techniques for measuring water-surface elevations. In ideal laboratory situations with simple flows, appropriate spatial and temporal averaging results in accurate water-surface elevations and water-surface velocities. In test cases, this accuracy is sufficient to allow direct inversion of the governing equations of motion to produce estimates of depth and discharge. Unlike other optical techniques for determining local depth that rely on transmissivity of the water column (bathymetric lidar, multi/hyperspectral correlation), this method uses only water-surface information, so even deep and/or turbid flows can be investigated. However, significant errors arise in areas of nonhydrostatic spatial accelerations, such as those associated with flow over bedforms or other relatively steep obstacles. Using laboratory measurements for test cases, the cause of these errors is examined and both a simple semi-empirical method and computational results are presented that can potentially reduce bathymetric inversion errors.

  1. The study of contamination of discharged runoff from surface water disposal channels of Bushehr city in 2012-2013

    Directory of Open Access Journals (Sweden)

    Vaheid Noroozi-Karbasdehi

    2016-09-01

    Full Text Available Background: In coastal cities, wastewater discharge into the sea is one of the options for sewage disposal that in case of non-compliance with health standards  in wastewater disposal will be led to the spread of infection and disease. On the other hand, water resources preservation and using them efficiently are the principles of sustainable development of each country. This study was aimed to investigate the contamination of discharged runoff from the surface water disposal channels of Bushehr city in 2012 - 13. Materials and Methods: In this study, Sampling was conducted by composite sampling method from output of the five main surface water disposal channels leading to the Persian Gulf located in the coastal region of Bushehr city during two seasons including wet (winter and dry (summer in 2012- 13. Then, experimental tests of BOD5, total coliform and fecal coliform were done on any of the 96 samples according to the standard method. Results: Analysis of the data showed that the BOD5, total coliform and fecal coliform of effluent runoff of the channels were more than the national standard output of disposal wastewaters into the surface waters, and the highest and lowest amount of BOD5 which obtained were 160 mg/L and 28 mg/L, respectively. Conclusion: considering the fact that discharged runoff from surface water disposal channels link from shoreline to sea in close distance and they often are as natural swimming sites and even fishing sites of Bushehr city, and also according to high level of organic and bacterial load of these channels, it is urgently required to be considered by the authorities.

  2. Water-surface elevation and discharge measurement data for the Red River of the North and its tributaries near Fargo, North Dakota, water years 2014–15

    Science.gov (United States)

    Damschen, William C.; Galloway, Joel M.

    2016-08-25

    The U.S. Geological Survey, in cooperation with the Fargo Diversion Board of Authority, collected water-surface elevations during a range of discharges needed for calibration of hydrologic and hydraulic models for specific reaches of interest in water years 2014–15. These water-surface elevation and discharge measurement data were collected for design planning of diversion structures on the Red River of the North and Wild Rice River and the aqueduct/diversion structures on the Sheyenne and Maple Rivers. The Red River of the North and Sheyenne River reaches were surveyed six times, and discharges ranged from 276 to 6,540 cubic feet per second and from 166 to 2,040 cubic feet per second, respectively. The Wild Rice River reach also was surveyed six times during 2014 and 2015, and discharges ranged from 13 to 1,550 cubic feet per second. The Maple River reach was surveyed four times, and discharges ranged from 16.4 to 633 cubic feet per second. Water-surface elevation differences from upstream to downstream in the reaches ranged from 0.33 feet in the Red River of the North reach to 9.4 feet in the Maple River reach.

  3. Point source nutrient discharges to surface water in the United States Pacific Northwest for 2002 summarized for NHDPlus v2 catchments

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial data set was created by the U.S. Geological Survey (USGS) to represent the amount of total nitrogen and total phosphorus discharged to surface waters in...

  4. Interaction between shallow groundwater, saline surface water and nutrient discharge in a seasonal estuary: the Swan-Canning system

    Science.gov (United States)

    Linderfelt, William R.; Turner, Jeffrey V.

    2001-09-01

    load to the Swan River derived from regionally advected groundwater discharge is conservatively estimated at between 30 and 60 t/year. This ranks groundwater as one of the highest single inputs of nitrogen to the Swan-Canning Estuary when compared to surface water flows. It contributes about 10% of the total nitrogen load entering this reach of the river. Seasonal and tidal variations increase the complexity of the system and may act to increase the presence and availability of groundwater-derived nutrients in the river and estuary system.Field observations and results from numerical groundwater flow modelling show that groundwater preferentially discharges into the Swan River along the outside of river meanders. Along the inside of meanders, groundwater discharge is either very low or at times the flow direction reverses such that saline river water recharges the aquifer during the late spring, summer and early autumn months. Short-term, high-frequency fluctuations such as wave-induced displacement, seawater intrusion, hyporheic flux and tidal fluctuations may cause small spatial scale mixing and perturbation of the nutrient-rich groundwater and sediment porewater with either the river water directly or with fresher groundwater as it discharges to the river. These short-term fluctuations appear to cause nutrient release from the sediment pore fluids, particularly in summer low flow periods such that they are a significant contributing factor in triggering algal blooms.

  5. Water-Surface Elevations, Discharge, and Water-Quality Data for Selected Sites in the Warm Springs Area near Moapa, Nevada

    Science.gov (United States)

    Beck, David A.; Ryan, Roslyn; Veley, Ronald J.; Harper, Donald P.; Tanko, Daron J.

    2006-01-01

    The U.S. Geological Survey, in cooperation with Southern Nevada Water Authority and the Nevada Division of Water Resources, operates and maintains a surface-water monitoring network of 6 continuous-record stream-flow gaging stations and 11 partial-record stations in the Warm Springs area near Moapa, Nevada. Permanent land-surface bench marks were installed within the Warm Springs area by the Las Vegas Valley Water District, the Southern Nevada Water Authority, and the U.S. Geological Survey to determine water-surface elevations at all network monitoring sites. Vertical datum elevation and horizontal coordinates were established for all bench marks through a series of Differential Global Positioning System surveys. Optical theodolite surveys were made to transfer Differential Global Positioning System vertical datums to reference marks installed at each monitoring site. The surveys were completed in June 2004 and water-surface elevations were measured on August 17, 2004. Water-surface elevations ranged from 1,810.33 feet above North American Vertical Datum of 1988 at a stream-gaging station in the Pederson Springs area to 1,706.31 feet at a station on the Muddy River near Moapa. Discharge and water-quality data were compiled for the Warm Springs area and include data provided by the U.S. Geological Survey, Nevada Division of Water Resources, U.S. Fish and Wildlife Service, Moapa Valley Water District, Desert Research Institute, and Converse Consultants. Historical and current hydrologic data-collection networks primarily are related to changes in land- and water-use activities in the Warm Springs area. These changes include declines in ranching and agricultural use, the exportation of water to other areas of Moapa Valley, and the creation of a national wildlife refuge. Water-surface elevations, discharge, and water-quality data compiled for the Warm Springs area will help identify (1) effects of changing vegetation within the former agricultural lands, (2) effects

  6. Importance of including small-scale tile drain discharge in the calibration of a coupled groundwater-surface water catchment model

    DEFF Research Database (Denmark)

    Hansen, Anne Lausten; Refsgaard, Jens Christian; Christensen, Britt Stenhøj Baun;

    2013-01-01

    the catchment. In this study, a coupled groundwater-surface water model based on the MIKE SHE code was developed for the 4.7 km2 Lillebæk catchment in Denmark, where tile drain flow is a major contributor to the stream discharge. The catchment model was calibrated in several steps by incrementally including...... the observation data into the calibration to see the effect on model performance of including diverse data types, especially tile drain discharge. For the Lillebæk catchment, measurements of hydraulic head, daily stream discharge, and daily tile drain discharge from five small (1–4 ha) drainage areas exist....... The results showed that including tile drain data in the calibration of the catchment model improved its general performance for hydraulic heads and stream discharges. However, the model failed to correctly describe the local-scale dynamics of the tile drain discharges, and, furthermore, including the drain...

  7. Dynamic Attribution of Global Water Demand to Surface Water and Groundwater Resources: Effects of Abstractions and Return Flows on River Discharge

    Science.gov (United States)

    de Graaf, Inge; van Beek, Rens; Wada, Yoshi; Bierkens, Marc

    2013-04-01

    As human water demand is increasing worldwide, groundwater is abstracted at rates that exceed groundwater recharge in many areas, resulting in depletion of existing groundwater stocks. Most studies, that focus on human water consumption and water stress indicate a gap between water demand and availability. However, between studies very different assumptions are made on how water abstraction is divided between surface water, groundwater, and other resources. Moreover, simplified assumptions are used of the interactions between groundwater and surface water. Here, we simulate at the global scale, the dynamic attribution of total water demand to surface water and groundwater resources, based on actual water availability and accounting for return flows and surface water- groundwater interactions. The global hydrological model PCR-GLOBWB is used to simulate water storages, abstractions, and return flows for the model period 1960-2010, with a daily time step at 0.5° x 0.5° spatial resolution. Total water demand is defined as requirements for irrigation, industry, and domestic use. Water abstractions are variably taken from surface water and groundwater resources depending on availability of both resources. Return flows of non-consumed abstracted water contribute to a single source; those of irrigation recharging groundwater, those of industry and domestic use discharging to surface waters. Groundwater abstractions are taken from renewable groundwater, or when exceeding recharge from an alternative unlimited resource. This resource consists of non-renewable groundwater, or non-local water, the former being an estimate of groundwater depletion. Results show that worldwide the effect of water abstractions is evident, especially on the magnitude and frequency of low flows when the contribution of groundwater through baseflow is substantial. River regimes are minimally affected by abstractions in industrial regions because of the high return flows. In irrigated regions the

  8. Influence of wastewater treatment plant discharges on microplastic concentrations in surface water.

    Science.gov (United States)

    Estahbanati, Shirin; Fahrenfeld, N L

    2016-11-01

    The abundance of microplastic particles in the marine environment is well documented, but less is known about microplastics in the freshwater environment. Wastewater treatment plants (WWTPs) may not effectively remove microplastics allowing for their release to the freshwater environment. To investigate concentration of microplastic in fresh water and the impact of WWTP effluent, samples were collected upstream and downstream of four major municipal WWTPs on the Raritan River, NJ. Microplastics were categorized into three quantitative categories (500-2000 μm, 250-500 μm, 125-250 μm), and one semi-quantitative category (63-125 μm). Then, microplastics were classified as primary (manufactured in small size) or secondary (derived from larger plastics) based on morphology. The concentration of microplastics in the 125-250 and 250-500 μm size categories significantly increased downstream of WWTP. The smaller size classes, often not quantified in microplastic studies, were in high relative abundance across sampling sites. While primary microplastics significantly increased downstream of WWTP, secondary microplastic was the dominant type in the quantitative size categories (66-88%). A moderate correlation between microplastic and distance downstream was observed. These results have implications for understanding the fate and transport of microplastics in the freshwater environment.

  9. Water purification by electrical discharges

    Science.gov (United States)

    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.}

  10. Application of ICP-OES for Evaluating Energy Extraction and Production Wastewater Discharge Impacts on Surface Waters in Western Pennsylvania

    Science.gov (United States)

    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) w...

  11. Cadmium removal from urban stormwater runoff via bioretention technology and effluent risk assessment for discharge to surface water

    Science.gov (United States)

    Wang, Jianlong; Zhang, Pingping; Yang, Liqiong; Huang, Tao

    2016-02-01

    Bioretention technology, a low-impact development stormwater management measure, was evaluated for its ability to remove heavy metals (specifically cadmium, Cd) from urban stormwater runoff. Fine sand, zeolite, sand and quartz sand were selected as composite bioretention media. The effects of these materials on the removal efficiency, chemical forms, and accumulation and migration characteristics of Cd were examined in laboratory scale bioretention columns. Heretofore, few studies have examined the removal of Cd by bioretention. A five-step sequential extraction method, a single-contamination index method, and an empirical migration equation were used in the experiments. The average Cd removal efficiency of quartz sand approached 99%, and removal by the other media all exceeded 90%. The media types markedly affected the forms of Cd found in the columns as well as its vertical migration rate. The Cd accumulated in the four media was mainly in residual form; moreover, accumulation of Cd occurred mainly in the surface layer of the bioretention column. The migration depth of Cd in the four media increased with elapsed time, in the following sequence: zeolite > quartz sand > fine sand > sand. In contrast, the migration rate decreased with elapsed time, and the migration rate of Cd was lowest in sand (0.015 m per annum over the first ten years). The comprehensive risk index analysis indicated that the risk arising from Cd discharge to surface water was "intermediate", and that the degree of risk was lowest in sand, then quartz sand, zeolite, and fine sand in sequence. These results indicate that the adsorption and accumulation of Cd in the four media are more significant than the migration of Cd. In addition, the results of Cd risk assessment for the effluent indicate that each of the four media can serve as long-term adsorption material in a bioretention facility for purifying stormwater runoff.

  12. Estimating ground water discharge by hydrograph separation.

    Science.gov (United States)

    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.

  13. Quantifying the level of improvement in discharge estimation from the SRTM-era to the proposed Surface Water Ocean Topography (SWOT)-mission era

    Science.gov (United States)

    Sikder, M. S.; Hossain, F.

    2014-12-01

    It was almost 15 years ago, when the Shuttle Radar Topography Mission (SRTM) flew for a few days to map the elevation of earth's surface. SRTM has since become the community standard for a global digital elevation model (DEM) and has triggered numerous studies that require elevation information. One particular avenue that has benefited the hydrologic community is the space-borne discharge estimation using water slope information that is afforded by the spatial imaging concept of SRTM. Numerous feasibility studies involving SRTM data for discharge estimation in rivers have led to adopting a similar concept for the proposed Surface Water and Ocean Topography (SWOT) mission (launch date: 2020). Because SWOT is expected to have significantly higher accuracy and smaller spatial scale in resolving the elevation characteristics of a water surface, it is important to understand the extent of improvement that SWOT will afford for discharge estimation once it is launched. In this study, we explored geophysical sources of uncertainty of satellite interferometric-based discharge estimation in Bangladesh delta of the Ganges, Brahmaputra and Meghna (GBM) river basins. This exploration was carried out for two scenarios: A) using SRTM elevation data and B) using SWOT-simulated elevation data. We contextualized the improvement in accuracy as a function of river's geophysical characteristics (river width, reach averaging length, bed/water slope) and also to explored a pragmatic approach to further uncertainty reduction using water level climatology. The discharge was estimated according to the slope-area (Manning's) method using elevation data assuming availability of in-situ river bathymetry (in order to remove uncertainty due to river cross section data). A high resolution hydrodynamic model was accurately calibrated (against in-situ water level data) to simulate water level and flow dynamics along the entire river reaches of the GBM river network and served as reference for

  14. Synoptic Multi-tracer Sensing for Mapping Groundwater-Surface Water Discharges and Estimating Reactive Nitrate Loading along a Gaining Lowland River

    Science.gov (United States)

    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.

  15. Assessing toxicity of copper, cadmium and chromium levels relevant to discharge limits of industrial effluents into inland surface waters using common onion, Allium cepa bioassay.

    Science.gov (United States)

    Hemachandra, Chamini K; Pathiratne, Asoka

    2015-02-01

    Toxicity of copper, cadmium and chromium relevant to established tolerance limits for the discharge of industrial effluents into inland surface waters was evaluated by Allium cepa bioassay. The roots of A. cepa bulbs exposed to Cu(2+) (3 mg L(-1)) individually or in mixtures with Cd(2+) (0.1 mg L(-1)) or/and Cr(6+) (0.1 mg L(-1)) exhibited the highest growth inhibition, mitotic index depression and nuclear abnormalities. Root tip cells exposed to Cr(6+) or Cd(2+) alone or in mixture displayed significant chromosomal aberrations in comparison to the controls. EC50s for root growth inhibition followed the order Cu(2+) < Cd(2+) < Cr(6+) indicating greater toxicity of copper. The results show that the industrial effluent discharge regulatory limits for these metals need to be reviewed considering potential cyto-genotoxicity to biological systems.

  16. Density-dependent surface water-groundwater interaction and nutrient discharge in the Swan-Canning Estuary

    Science.gov (United States)

    Smith, Anthony J.; Turner, Jeffrey V.

    2001-09-01

    Salinity in the Swan-Canning Estuary, Western Australia, varies seasonally from freshwater conditions in winter up to the salinity of seawater in summer. Field observations show that the resulting seasonal density contrasts between the estuary and the adjacent fresh groundwater system are sufficient to drive mixed-convection cells that give rise to circulation of river water in the aquifer. In this study, we examine the role of steady density-driven convection as a mechanism that contributes to the exchange of dissolved nutrients, particularly ammonium, between the Swan-Canning Estuary and the local groundwater system. We present results from two-dimensional (section) and three-dimensional density-coupled flow and mass transport modelling, in comparison with Glover's abrupt-interface solution for saltwater intrusion. The modelling is focused on developing an understanding of the physical processes that influence the long-term or mean convective behaviour of groundwater beneath the estuary. It is shown that the convective stability depends fundamentally on the interplay between two factors: (1) the downward destabilizing buoyancy effect of density contrasts between the estuary and aquifer; and (2) the upward stabilizing influence of regional groundwater discharge. The structure of convection cells beneath the estuary and recirculation rates of estuary water within the groundwater system are shown to be related to a flow-modified Rayleigh number that depends critically on the aquifer anisotropy and estuary meander pattern. The recirculation of estuary water by these mechanisms is responsible for transport of high concentrations of ammonium, observed in pore fluids in the estuary bed sediments, into groundwater and its eventual return to the estuary.

  17. Surface Water & Surface Drainage

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains boundaries for all surface water and surface drainage for the state of New Mexico. It is in a vector digital data structure digitized from a...

  18. Computational study of temporal behavior of incident species impinging on a water surface in dielectric barrier discharge for the understanding of plasma-liquid interface

    Science.gov (United States)

    Suda, Yoshiyuki; Oda, Akinori; Kato, Ryo; Yamashita, Ryuma; Tanoue, Hideto; Takikawa, Hirofumi; Tero, Ryugo

    2015-01-01

    A lipid bilayer is a basic structure of the cell membrane and is stable in liquid solution. In this study, we analyzed dielectric barrier discharge (DBD) containing water on a quartz substrate using a one-dimensional fluid model. To simulate atmospheric pressure plasma for practical use, a tiny amount of N2 gas (0.5 ppm) was added to He gas ambient as an impure gas. The calculated current-voltage (I-V) characteristics reproduced the measured ones qualitatively. We focused on the behavior of DBD at the plasma-liquid interface and analyzed the temporal behavior of the electric field strength and incident fluxes of charged, excited, and radical species on the water surface. By varying the gap length, it was shown that the maximum electric field strength in an AC cycle saturated at gap lengths ≥0.15 cm. The incident fluxes of N2+ and He2+ on the water surface are almost the same and show strong correlations with the electric field in the vicinity of the water surface.

  19. Arc discharge sliding over a conducting surface

    NARCIS (Netherlands)

    Goor, van F.A.; Mitko, S.V.; Ochkin, V.N.; Paramonov, A.P.; Witteman, W.J.

    1997-01-01

    Results of experimental and theoretical studies of the arc discharge which slides over the surface of a conductor are reported. Experiments were performed in air and argon ambients at various pressures. It is found that the velocity of the discharge plasma front depends linearly on the strength of t

  20. Surface modification of polycarbonate in homogeneous atmospheric pressure discharge

    Energy Technology Data Exchange (ETDEWEB)

    SIra, M; Trunec, D; St' ahel, P; BursIkova, V; Navratil, Z [Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic)

    2008-01-07

    A homogeneous atmospheric pressure dielectric barrier discharge was used for the surface modification of polycarbonate (PC). The discharge was generated between two planar metal electrodes, the top electrode was covered by glass and the bottom electrode was covered by a polymer sample. The discharge burned in pure nitrogen or in a mixture of nitrogen and hydrogen. The surface properties of both treated and untreated polymers were characterized by atomic force microscopy, surface free energy (SFE) measurements and x-ray photoelectron spectroscopy. The influence of the treatment time and power input to the discharge on the surface properties of polymers was studied. The ageing of treated samples was also investigated. The treatment of polymers in the homogeneous atmospheric pressure discharge was homogeneous and the polymer surfaces showed a smaller degree of roughness in comparison with the polymer surfaces treated in a filamentary discharge. The SFE of the treated PC obtained at optimum conditions was 53 mJ m{sup -2} and the corresponding contact angle of water was 38{sup 0}. The maximum decrease in the SFE during ageing was about 13%. The analysis of the chemical composition showed an increase in the nitrogen concentration in the surface layer, but almost a zero increase in the oxygen concentration. This result was discussed concerning the measured values of the SFE measurement.

  1. Surface micro-discharges on spacecraft dielectrics

    Science.gov (United States)

    Balmain, K. G.; Cuchanski, M.; Kremer, P. C.

    1977-01-01

    Extensive measurements on Teflon and Kapton in a scanning electron microscope indicate the existence of a well-defined family of surface micro-discharges characteristic of the dielectric material. For a given small region exposed to the 16-20 kV electron beam, the strongest discharge pulses are similar in shape and amplitude. For Teflon, typical pulse durations are 2-3 ns, rise and fall times are sometimes as low as 0.2 ns, current amplitudes are approximately 100 mA flowing down to the pedestal and the pulses are unidirectional with no ringing. The use of a rapid-scan electron microscope with a secondary-electron imaging system reveals complex charge distributions resembling Lichtenberg figures on a supposedly flat homogeneous dielectric surface. These patterns undergo extensive alteration at each micro-discharge pulse and indicate that both the charging and discharging processes are highly nonuniform over the dielectric surface. The use of floodbeam causes the occurrence of a large-scale macro-discharges, in which a typical peak current is 40 A with a duration of 120 ns.

  2. State-by-state emission spectra fitting for non-equilibrium plasmas: OH spectra of surface barrier discharge at argon/water interface

    Science.gov (United States)

    Voráč, Jan; Synek, Petr; Procházka, Vojtěch; Hoder, Tomáš

    2017-07-01

    Optical emission spectroscopy applied to non-equilibrium plasmas in molecular gases can give important information on basic plasma parameters, including the rotational and vibrational temperatures and densities of the investigated radiative states. In order to precisely understand the non-equilibrium of rotational-vibrational state distribution from the investigated spectra without limiting presumptions, a state-by-state temperature-independent fitting procedure is the ideal approach. In this paper, we present a novel software tool developed for this purpose, freely available for the scientific community. The introduced tool offers a convenient way to construct Boltzmann plots even from partially overlapping spectra, in a user-friendly environment. We apply the novel software to the challenging case of OH spectra in surface streamer discharges generated from the triple-line of the argon/water/dielectrics interface. After the barrier discharge is characterised by ICCD and electrical measurements, the spatially and phase resolved rotational temperatures from N2(C-B) and OH(A-X) spectra are determined and compared. The precise analysis shows that OH(A) states with quantum numbers ≤ft({{v}\\prime}=0,~9≤slant {{N}\\prime}≤slant 13\\right) are overpopulated with respect to the found two-Boltzmann distribution. We hypothesise that fast vibrational-energy transfer is responsible for this phenomenon, observed here for the first time. Finally, the vibrational temperature of the plasma and the relative populations of hot and cold OH(A) states are quantified spatially and phase resolved.

  3. Characterisation of pulsed discharge in water

    Science.gov (United States)

    Kocik, Marek; Dors, Miroslaw; Podlinski, Janusz; Mizeraczyk, Jerzy; Kanazawa, Seiji; Ichiki, Ryuta; Sato, Takehiko

    2013-10-01

    In this paper, Schlieren photography technique has been applied for the visualization of the pressure field of a single-shot underwater pulsed discharge. A needle-to-plane electrode configuration submerged in distilled water was used. The detailed time- and space-resolved images of both streamers and pressure waves were captured. As a result, several phenomena, such as the phase change prior to the initiation of the discharge, primary and secondary streamers propagation, shock wave generation, and the bubble formation, were observed. From these observations, a scenario of multiple events from prebreakdown to post-discharge was proposed. The gas bubbles generated in discharge were used to visualize the electrohydrodynamic flow induced by the discharge. This work was presented on the occasion of the 13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII).

  4. Enhanced removal of humic acid from micro-polluted source water in a surface discharge plasma system coupled with activated carbon.

    Science.gov (United States)

    Wang, Tiecheng; Li, Yujuan; Qu, Guangzhou; Sun, Qiuhong; Liang, Dongli; Hu, Shibin; Zhu, Lingyan

    2017-07-26

    Surface discharge plasma (SDP) combined with activated carbon (AC) was employed to eliminate dissolved organic matter from micro-polluted source water, with humic acid (HA) as the model pollutant. Synergistic effect on HA removal was observed in the SDP-AC system; HA removal efficiency reached 60.9% within 5-min treatment in the SDP-AC system with 5.0 g AC addition, whereas 16.7 and 17.4% of HA were removed in sole SDP system and AC adsorption, respectively. Scanning electron microscope and Boehm titration analysis showed that chemical reactions between active species and functional groups of AC occurred. The existence of isopropanol or benzoquinone exhibited inhibitive effects on HA removal in the SDP system, while these inhibitive effects were weakened in the SDP-AC system. The influences of AC on ozone equivalent concentration and H2O2 concentration were evaluated, and there were approximately 39 and 20% decline in ozone equivalent concentration and H2O2 concentration within 6-min treatment in the SDP-AC system, respectively, compared with those in the sole SDP system. Dissolved organic carbon, specific ultraviolet absorbance, and UV absorption ratios analysis demonstrated that the SDP treatment destroyed the chromophoric groups, double bonds, and aromatic structure of HA molecules, and these destructive actions were strengthened by AC.

  5. Study on the transition from filamentary discharge to diffuse discharge by using a dielectric barrier surface discharge device

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Discharge characteristics have been investigated in different gases under different pressures using a dielectric barrier surface discharge device. Electrical measurements and optical emission spectroscopy are used to study the discharge,and the results obtained show that the discharges in atmospheric pressure helium and in low-pressure air are diffuse,while that in high-pressure air is filamentary. With decreasing pressure, the discharge in air can transit from filamentary to diffuse one. The results also indicate that corona discharge around the stripe electrode is important for the diffuse discharge. The spectral intensity of N2+ (391.4 nm) relative to N2 (337.1 nm) is measured during the transition from diffuse to filamentary discharge. It is shown that relative spectral intensity increases during the discharge transition. This phenomenon implies that the averaged electron energy in diffuse discharge is higher than that in the filamentary discharge.

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

    Energy Technology Data Exchange (ETDEWEB)

    Haggard, R.D.

    1996-08-12

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

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

    Science.gov (United States)

    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.

  8. Innovative Use of Cr(VI) Plume Depictions and Pump-and-Treat Capture Analysis to Estimate Risks of Contaminant Discharge to Surface Water at Hanford Reactor Areas

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Chuck W.; Hanson, James P.; Ivarson, Kristine A.; Tonkin, M.

    2015-01-14

    The Hanford Site nuclear reactor operations required large quantities of high-quality cooling water, which was treated with chemicals including sodium dichromate dihydrate for corrosion control. Cooling water leakage, as well as intentional discharge of cooling water to ground during upset conditions, produced extensive groundwater recharge mounds consisting largely of contaminated cooling water and resulted in wide distribution of hexavalent chromium (Cr[VI]) contamination in the unconfined aquifer. The 2013 Cr(VI) groundwater plumes in the 100 Areas cover approximately 6 km2 (1500 acres), primarily in the 100-HR-3 and 100-KR-4 groundwater operable units (OUs). The Columbia River is a groundwater discharge boundary; where the plumes are adjacent to the Columbia River there remains a potential to discharge Cr(VI) to the river at concentrations above water quality criteria. The pump-and-treat systems along the River Corridor are operating with two main goals: 1) protection of the Columbia River, and 2) recovery of contaminant mass. An evaluation of the effectiveness of the pump-and-treat systems was needed to determine if the Columbia River was protected from contamination, and also to determine where additional system modifications may be needed. In response to this need, a technique for assessing the river protection was developed which takes into consideration seasonal migration of the plume and hydraulic performance of the operating well fields. Groundwater contaminant plume maps are generated across the Hanford Site on an annual basis. The assessment technique overlays the annual plume and the capture efficiency maps for the various pump and treat systems. The river protection analysis technique was prepared for use at the Hanford site and is described in detail in M.J. Tonkin, 2013. Interpolated capture frequency maps, based on mapping dynamic water level observed in observation wells and derived water levels in the vicinity of extraction and injection wells

  9. Charging of moving surfaces by corona discharges sustained in air

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun-Chieh, E-mail: junchwan@umich.edu; Kushner, Mark J., E-mail: mjkush@umich.edu [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122 (United States); Zhang, Daihua, E-mail: dhzhang@tju.edu.cn [Tianjin University, Tianjin (China); Leoni, Napoleon, E-mail: napoleon.j.leoni@hp.com; Birecki, Henryk, E-mail: henryk.birecki@hp.com; Gila, Omer, E-mail: omer-gila@hp.com [Hewlett-Packard Research Labs, Palo Alto, California 94304 (United States)

    2014-07-28

    Atmospheric pressure corona discharges are used in electrophotographic (EP) printing technologies for charging imaging surfaces such as photoconductors. A typical corona discharge consists of a wire (or wire array) biased with a few hundred volts of dc plus a few kV of ac voltage. An electric discharge is produced around the corona wire from which electrons drift towards and charge the underlying dielectric surface. The surface charging reduces the voltage drop across the gap between the corona wire and the dielectric surface, which then terminates the discharge, as in a dielectric barrier discharge. In printing applications, this underlying surface is continuously moving throughout the charging process. For example, previously charged surfaces, which had reduced the local electric field and terminated the local discharge, are translated out of the field of view and are replaced with uncharged surface. The uncharged surface produces a rebound in the electric field in the vicinity of the corona wire which in turn results in re-ignition of the discharge. The discharge, so reignited, is then asymmetric. We found that in the idealized corona charging system we investigated, a negatively dc biased corona blade with a dielectric covered ground electrode, the discharge is initially sustained by electron impact ionization from the bulk plasma and then dominated by ionization from sheath accelerated secondary electrons. Depending on the speed of the underlying surface, the periodic re-ignition of the discharge can produce an oscillatory charging pattern on the moving surface.

  10. Charging of moving surfaces by corona discharges sustained in air

    Science.gov (United States)

    Wang, Jun-Chieh; Zhang, Daihua; Leoni, Napoleon; Birecki, Henryk; Gila, Omer; Kushner, Mark J.

    2014-07-01

    Atmospheric pressure corona discharges are used in electrophotographic (EP) printing technologies for charging imaging surfaces such as photoconductors. A typical corona discharge consists of a wire (or wire array) biased with a few hundred volts of dc plus a few kV of ac voltage. An electric discharge is produced around the corona wire from which electrons drift towards and charge the underlying dielectric surface. The surface charging reduces the voltage drop across the gap between the corona wire and the dielectric surface, which then terminates the discharge, as in a dielectric barrier discharge. In printing applications, this underlying surface is continuously moving throughout the charging process. For example, previously charged surfaces, which had reduced the local electric field and terminated the local discharge, are translated out of the field of view and are replaced with uncharged surface. The uncharged surface produces a rebound in the electric field in the vicinity of the corona wire which in turn results in re-ignition of the discharge. The discharge, so reignited, is then asymmetric. We found that in the idealized corona charging system we investigated, a negatively dc biased corona blade with a dielectric covered ground electrode, the discharge is initially sustained by electron impact ionization from the bulk plasma and then dominated by ionization from sheath accelerated secondary electrons. Depending on the speed of the underlying surface, the periodic re-ignition of the discharge can produce an oscillatory charging pattern on the moving surface.

  11. Discharge Characteristics in Atmospheric Pressure Glow Surface Discharge in Helium Gas

    Institute of Scientific and Technical Information of China (English)

    LI Xue-Chen; WANG Long

    2005-01-01

    @@ Atmospheric pressure glow discharge is observed for the first time in a surface discharge generator in flowing helium. Electrical and optical methods are used to measure the characteristics of atmospheric pressure glow discharge for different voltages. The results show that discharge current waveforms are asymmetric for the different polarities of the applied voltage. A continuous discharge profile with a width of several microseconds appears for per half cycle of the applied voltage when the voltage is increased to a certain value. The short-pulsed discharge and the continuous current would result from the Townsend breakdown and glow discharge mechanisms respectively. The properties of surface discharge in stagnant helium are completely different from that in flowing helium.

  12. Benefits of Riverine Water Discharge into the Lorian Swamp, Kenya

    Directory of Open Access Journals (Sweden)

    Zipporah Musyimi

    2012-12-01

    Full Text Available Use and retention of river water in African highlands deprive communities in arid lowlands of their benefits. This paper reviews information on water use in the Ewaso Ng’iro catchment, Kenya, to evaluate the effects of upstream abstraction on the Lorian Swamp, a wetland used by pastoralists downstream. We first assess the abstractions and demands for water upstream and the river water supplies at the upper and the lower end of the Lorian Swamp. Further analysis of 12 years of monthly SPOT-VEGETATION satellite imagery reveals higher NDVI (Normalized Differential Vegetation Index values in the swamp than nearby rainfed areas, with the difference in NDVI between the two positively related to river water discharged into the swamp. The paper next reviews the benefits derived from water entering the swamp and the vulnerability to abstractions for three categories of water: (i the surface water used for drinking and sanitation; (ii the surface water that supports forage production; and (iii the water that recharges the Merti Aquifer. Our results suggest that benefits from surface water for domestic use and forage production are vulnerable to abstractions upstream whereas the benefits from the aquifer, with significant fossil water, are likely to be affected in the long run, but not the short term.

  13. Glow and pseudo-glow discharges in a surface discharge generator

    Institute of Scientific and Technical Information of China (English)

    Li Xue-Chen; Dong Li-Fang; Wang Long

    2005-01-01

    The glow discharge in flowing argon at one atmospheric pressure is realized in a surface discharge generator. The discharge current presents one peak per half-cycle of the applied voltage. The duration of the discharge pulse is more than 1μs when the frequency of the applied voltage is 60kHz. For the glow discharge in argon, the power consumption increases with the increase of voltage or the decrease of gas pressure.This relation is explained qualitatively based on the theory of the Townsend breakdown mechanism. In contrast, the discharge current in one atmospheric pressure air gives many spikes in each half-cycle, and correspondingly this kind of discharge is called pseudo-glow discharge. Every current spike oscillates with high-frequency damping. The pseudo-glow discharge in one atmospheric pressure air might result from the streamer breakdown mechanism.

  14. Dielectric barrier discharge plasma treatment of cellulose nanofibre surfaces

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Madsen, Bo; Berglund, Linn

    2017-01-01

    on the nanofibre surface. Ultrasonic irradiation further enhanced the wetting and oxidation of the nanofibre coating. Scanning electron microscopic observations showed skeleton-like features on the plasma-treated surface, indicating preferential etching of weaker domains, such as low-molecular weight domains......Dielectric barrier discharge plasma treatment was applied to modify cellulose nanofibre (CNF) surfaces with and without ultrasonic irradiation. The plasma treatment improved the wetting by deionised water and glycerol, and increased the contents of oxygen, carbonyl group, and carboxyl group...... and amorphous phases. Ultrasonic irradiation also improved the uniformity of the treatment. Altogether, it is demonstrated that atmospheric pressure plasma treatment is a promising technique to modify the CNF surface before composite processing....

  15. Early Stage of Pulsed Discharge in Water

    Institute of Scientific and Technical Information of China (English)

    卢新培; 潘垣; 刘克富; 刘明海; 张寒虹

    2001-01-01

    The bubble radius at the early stage of discharge in water is investigated using high-speed photography. Some simulation results on the bubble radius are presented, which are in agreement with the experimental results, with a maximum difference of about 10%. The reasons why the peak pressure of the first shock wave is only related to the energy released in the bubble during the first half period are addressed. The energy released in the bubble after the first half period increases the bubble pulsation period, but it produces no more than 10% under the peak pressure of the second shock wave.

  16. Application of dielectric surface barrier discharge for food storage

    Directory of Open Access Journals (Sweden)

    Yassine BELLEBNA

    2015-12-01

    Full Text Available Ozone (O3 is a powerful oxidizer and has much higher disinfection potential than chlorine and other disinfectants. Ozone finds its application mainly in water treatment and air purification Dielectric barrier discharge (DBD method has proved to be the best method to produce ozone. Dried air or oxygen is forced to pass through a 1-2 mm gap. The aim of this study was to show that disinfection system using ozone generated by dielectric barrier discharge (DBD is an effective alternative to be used in food industry and ensures a safe quality of air for optimum preservation of fruits and vegetables. The DBDs are specific kind of discharges because one (or sometimes both electrodes is covered by a dielectric material, thereby preventing the discharge to move towards electrical breakdown. A succession of microdischarges occurs rapidly; their "lifetime" is in the range of a few nanoseconds. One of their most important applications is the production of ozone for air treatment, used mainly in the area of food industry, for extending the storage life of foods. After the achievement of a surface DBD reactor of cylindrical shape and its electrical characterization, it was then used as an ozone generator for air disinfection. Obtained results have shown that this reactor used as an ozone generator is effective for disinfection of air by removing viruses, bacteria and pathogens, causing the slowdown of the ripening process of fruits and vegetables.

  17. Water withdrawals, use, discharge, and trends in Florida, 1995

    Science.gov (United States)

    Marella, R.L.

    1999-01-01

    , Lake Apopka, Lake Okeechobee and associated canals, and the St. Johns River. Freshwater withdrawals increased nearly 29 percent in Florida between 1970 and 1995. Ground-water withdrawals increased 56 percent, and surface-water withdrawals increased 2 percent during this period. Between 1990 and 1995, freshwater withdrawals decreased 5 percent. Fresh ground-water withdrawals decreased 7 percent, and fresh surface-water withdrawals decreased 1 percent during this period. Saline water withdrawals increased 13 percent between 1970 and 1995, and increased 6 percent between 1990 and 1995. An estimated 39 percent of the freshwater withdrawn in Florida was consumed; the remaining 61 percent was returned for use again. Wastewater discharged from the 615 treatment facilities inventoried in 1995 totaled 1,836 Mgal/d, of which 84 percent was from domestic wastewater facilities and the remaining 16 percent was from industrial facilities. Domestic wastewater discharge increased 37 percent between 1985 and 1995, while industrial wastewater discharge increased 7 percent during this period.

  18. Surface degradation of silicone rubber exposed to corona discharge

    OpenAIRE

    Zhu, Yong; Haji, Kenichi; Otsubo, Masahisa; Honda, Chikahisa

    2006-01-01

    This paper describes the surface degradation of unfilled high-temperature vulcanized silicone rubber (HTV-SR)###resulting from creeping corona discharges under atmospheric pressure. In this paper, HTV-SR specimens were exposed to corona###stress generated by a parallel needle-plate electrode system; furthermore, physicochemical analyses were conducted on the surface layer of SR before and after corona discharge treatment. The results showed that the plasma impingement from the corona discharg...

  19. Fractal characterization of surface electrical discharges

    Energy Technology Data Exchange (ETDEWEB)

    Egiziano, L.; Femia, N.; Lupo' , G.; Tucci, V. (Salerno Univ. (Italy). Ist. di Ingegneria Elettronica Naples Univ. (Italy). Dip. di Ingegneria Elettrica)

    1991-01-01

    The concepts of fractal geometry have been usefully applied to describe several physical processes whose growth mechanisms are characterized by complex topological structures. The fractal characterization of electrical discharges taking place at the air/solid dielectric interface is considered in this paper. A numerical procedure allowing the reproduction the typical discharge patterns, known as Lichtenberg figures, is presented: the growth process of the discharge is simulated by solving iteratively the Laplace equation with moving boundary conditions and by considering two power probability laws whose exponents determine the ramification level of the structure. The discharge patterns are then considered as fractal sets and their characteristic parameters are determined. The dependence of the typical structures on the two exponents of the probability laws are also discussed.

  20. Improvement of water quality using dielectric barrier discharge plasma

    Science.gov (United States)

    Quyen, N. T.; Traikool, T.; Nitisoravut, R.; Onjun, T.

    2017-06-01

    The improvement of water quality using by atmospheric plasma produced from a dielectric barrier discharge (DBD) was studied. An experiment was set-up with a 4 mm diameter pipe, which contains 2 electrodes and has an air flow with the rate of 15 liters per minute. Surface water, domestic wastewater and DI water were treated with the DBD plasma for some period of time. Electricity was supplied at 3.5 kV with the frequency of 5.5 kHz. Some key parameters of water quality includes the level of chemical oxygen demand (COD), total suspended solid (TSS), color, and odor are measured before and after. The result showed that strong acid with pH below 2 was observed after 60 minutes plasma treatment for the DI water, while the surface water and wastewater needs about 120 minutes to pH below 2 even though the pH value are about the same at the beginning. Moreover, It was formed that the COD, TSS microorganism was noticeably decreased, therefore the increasing of transparency level. This result confirms that atmospheric DBD plasma generated acidity in water as reduce amount of organic and suspended solid in water.

  1. Optical Spectra of the High Voltage Erosive Water Discharge

    CERN Document Server

    Pirozerski, A L

    2008-01-01

    In the present paper kinetics of emission spectra of the high voltage erosive water discharge at near ultraviolet and visible spectral ranges has been investigated. Obtained results show a similarity of physical properties of this discharge (and of corresponding plasmoids) to that of some other types of erosional discharges which also result in the formation of dust-gas fireballs.

  2. Free-surface flow simulations for discharge-based operation of hydraulic structure gates

    CERN Document Server

    Erdbrink, C D; Sloot, P M A

    2014-01-01

    We combine non-hydrostatic flow simulations of the free surface with a discharge model based on elementary gate flow equations for decision support in operation of hydraulic structure gates. A water level-based gate control used in most of today's general practice does not take into account the fact that gate operation scenarios producing similar total discharged volumes and similar water levels may have different local flow characteristics. Accurate and timely prediction of local flow conditions around hydraulic gates is important for several aspects of structure management: ecology, scour, flow-induced gate vibrations and waterway navigation. The modelling approach is described and tested for a multi-gate sluice structure regulating discharge from a river to the sea. The number of opened gates is varied and the discharge is stabilized with automated control by varying gate openings. The free-surface model was validated for discharge showing a correlation coefficient of 0.994 compared to experimental data. A...

  3. Groundwater–Surface Water Exchange

    DEFF Research Database (Denmark)

    Karan, Sachin

    The exchange of groundwater-surface water has been invetigated in the western part of Denmark. Holtum AA provides the framework for all the performed investigations. Several methods are used, primarily eld based measurements ombined with numerical models to achieve insight to the governing...... processes of interaction between groundwater and surface water. By using heat as a tracer it has been possible to use temperature directly as calibrationtargets in a groundwater and heat transport model. Thus, it is possible to use heat investigate the change in groundwater discharge in dynamic conditions...... by using simple temperature devices along a stream to delineate the areas of interest in regard to GW{SW exchange. Thus, at several locations in a stream a temperature data logger was placed in the water column and right at the streambed-water interface. By looking at the correlation of streambed...

  4. Groundwater–Surface Water Exchange

    DEFF Research Database (Denmark)

    Karan, Sachin

    The exchange of groundwater-surface water has been invetigated in the western part of Denmark. Holtum AA provides the framework for all the performed investigations. Several methods are used, primarily eld based measurements ombined with numerical models to achieve insight to the governing...... processes of interaction between groundwater and surface water. By using heat as a tracer it has been possible to use temperature directly as calibrationtargets in a groundwater and heat transport model. Thus, it is possible to use heat investigate the change in groundwater discharge in dynamic conditions...... by using simple temperature devices along a stream to delineate the areas of interest in regard to GW{SW exchange. Thus, at several locations in a stream a temperature data logger was placed in the water column and right at the streambed-water interface. By looking at the correlation of streambed...

  5. Pulsed electrical discharges in water for removal of organic pollutants: a comparative study

    OpenAIRE

    Dang, T.H.; Denat, A.; Lesaint, O.; Teissedre, G.

    2009-01-01

    Abstract In this study, the efficiency of different types of pulsed electrical discharges for the removal of organic pollutants from wastewater has been determined. Three discharge types, either in the water volume or in close proximity to the water surface are studied. The production of hydrogen peroxide in pure water, and the degradation of two typical pollutants (4-chlorophenol and 4-nitrophenol) is measured together with the amount of electrical energy d...

  6. Studying surface glow discharge for application in plasma aerodynamics

    Science.gov (United States)

    Tereshonok, D. V.

    2014-02-01

    Surface glow discharge in nitrogen between two infinite planar electrodes occurring on the same plane has been studied in the framework of a diffusion-drift model. Based on the results of numerical simulations, the plasma structure of this discharge is analyzed and the possibility of using it in plasma aerodynamics is considered.

  7. Discharge Water Quality Models of Storm Runoff in a Catchment

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The relationships between the water qualities of nitrogen and phosphorous contents in the discharge water and the discharge of storm runoff of an experimental catchment including terraced paddy field are analyzed based on experiment results of the catchment. By summarizing the currently related research on water quality models, the water quality models of different components of storm runoff of the catchment are presented and verified with the experiment data of water quality analyses and the corresponding discharge of the storm runoffs during 3 storms. Through estimating the specific discharge of storm runoff, the specific load of different components of nitrogen and phosphorus in the discharge water of the catchment can be forecasted by the models. It is found that the mathematical methods of linear regression are very useful for analysis of the relationship between the concentrations of nitrogen and phosphorus and the water discharge of storm runoff. It is also found that the most content of the nitrogen (75%) in the discharge water is organic, while half of the content (49%) of phosphorus in the discharge water is inorganic.

  8. RF-PACVD of water repellent and protective HMDSO coatings on bell metal surfaces: Correlation between discharge parameters and film properties

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, A.J. [Materials Science Division, Institute of Advanced Study in Science and Technology, Paschim Boragaon, Guwahati 781035, Assam (India); Barve, S.A. [Laser and Plasma Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Chutia, Joyanti, E-mail: joyanti_c@sify.com [Materials Science Division, Institute of Advanced Study in Science and Technology, Paschim Boragaon, Guwahati 781035, Assam (India); Pal, A.R. [Materials Science Division, Institute of Advanced Study in Science and Technology, Paschim Boragaon, Guwahati 781035, Assam (India); Kishore, R. [Material Science Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Jagannath [Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Pande, M. [High Pressure Physics Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Patil, D.S. [Laser and Plasma Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India)

    2011-08-01

    Hexamethyldisiloxane (HMDSO) films have been deposited on bell metal using radiofrequency plasma assisted chemical vapor deposition (RF-PACVD) technique. The protective performances of the HMDSO films and their water repellency have been investigated as a function of DC self-bias voltage on the substrates during deposition. Plasma potential measurements during film deposition process are carried out by self-compensated emissive probe. Optical emission spectroscopy (OES) analyses of the plasma during deposition reveal no significant change in the plasma composition within the DC self-bias voltage range of -40 V to -160 V that is used. Raman and X-ray photoelectron spectroscopy (XPS) studies are carried out for film chemistry analysis and indicate that the impinging ion energy on the substrates influences the physio-chemical properties of the HMDSO films. At critical ion energy of 113 qV (corresponding to DC self-bias voltage of -100 V), the deposited HMDSO film exhibits least defective Si-O-Si chemical structure and highest inorganic character and this contributes to its best corrosion resistance behavior. The hardness and elastic modulus of the films are found to be bias dependent and are 1.27 GPa and 5.36 GPa for films deposited at -100 V. The critical load for delamination is also bias dependent and is 11 mN for this film. The water repellency of the HMDSO films is observed to be dependent on the variation in surface roughness. The results of the investigations suggest that HMDSO films deposited by RF-PACVD can be used as protective coatings on bell metal surfaces.

  9. Ambient-temperature trap/release of arsenic by dielectric barrier discharge and its application to ultratrace arsenic determination in surface water followed by atomic fluorescence spectrometry

    Science.gov (United States)

    A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HGAFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical m...

  10. Surface Water Data at Los Alamos National Laboratory 1998 Water Year

    Energy Technology Data Exchange (ETDEWEB)

    D. A. Shaull; M. R. Alexander; R. P. Reynolds; C. T. McLean; R. P. Romero

    1999-02-01

    The principal investigators collected and computed surface water discharge data from 19 stream-gaging stations that cover most of Los Alamos National Laboratory. Also included are discharge data from three springs that flow into Caiion de Vane.

  11. AGING EFFECTS OF REPEATEDLY GLOW-DISCHARGED POLYETHYLENE - INFLUENCE ON CONTACT-ANGLE, INFRARED-ABSORPTION, ELEMENTAL SURFACE-COMPOSITION, AND SURFACE-TOPOGRAPHY

    NARCIS (Netherlands)

    VANDERMEI, HC; STOKROOS, [No Value; SCHAKENRAAD, JM; BUSSCHER, HJ

    1991-01-01

    Aging effects of repeatedly oxygen glow-discharged polyethylene surfaces were determined by water contact angle measurements, infrared (IR) spectroscopy, X-ray photoelectron (XPS) spectroscopy, and surface topography determination. Glow-discharged surfaces were stored at room temperature and in liqu

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

    Science.gov (United States)

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

    2014-05-01

    Keywords: cellulose; biosorbent; PAHs; polycontaminated wastewaters; trace levels. Polycyclic aromatic hydrocarbons (PAHs), chemicals essentially formed during incomplete combustion of organic materials from anthropogenic activities, were present in all compartments of the ecosystem, air, water and soil. Notably, a part of PAHs found in aquatic system was introduced through industrial discharge waters. Since the Water Framework Directive has classified certain PAHs as priority hazardous substances, industrials are called to take account this kind of organic pollutants in their global environmental concern. Conventional materials such as activated carbons definitively proved their worth as finishing treatment systems but remained costly. In this study, we proposed to use cellulose grafted with glycidyl methacrylate [1] for the removal of PAHs present in discharge waters of surface treatment industries. Firstly, to develop the device, we worked with synthetic solutions containing 16 PAHs at 500 ng/L. Two types of grafted cellulose were tested over a closed-loop column with a concentration of 4g cellulose/L: cellulose C2 with a hydroxide group and cellulose C4 with an amine group. No PAH was retained by the raw cellulose whereas abatement percentages of PAHs were similar between C2 and C4 (94% and 98%, respectively, for the sum of the 16 PAHs) with an experiment duration of 400 min (corresponding to about 20 cycles through grafted cellulose). Secondly, to determine the shorter time to abate the amount maximum of PAHs through the system, a kinetic was realized from 20 min (one cycle) to 400 min with C4. The steady state (corresponding to about 95% of abatement of the total PAHs) was reached at 160 min. Finally, the system was then tested with real industrial discharge waters containing both mineral and organic compounds. The results indicated that the abatement percentage of PAHs was similar between C2 and C4, corroborating the tests with synthetic solution. In return

  13. Electric discharge in water as a source of UV radiation, ozone and hydrogen peroxide

    Science.gov (United States)

    Anpilov, A. M.; Barkhudarov, E. M.; Bark, Yu B.; Zadiraka, Yu V.; Christofi, M.; Kozlov, Yu N.; Kossyi, I. A.; Kop'ev, V. A.; Silakov, V. P.; Taktakishvili, M. I.; Temchin, S. M.

    2001-03-01

    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≤λ≤430 nm) has been determined and the absolute number of quanta in this wavelength interval has been measured. The potentiality of the slipping surface discharge in water for its disinfection is analysed. The energy expenditure for water cleansing is estimated to be as low as ~10-4 kWh l-1.

  14. Waste water discharges into natural waters; Problematiche sulla dispersione di effluenti liquidi da canali o condotte a pelo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Marri, P. [ENEA, Centro Ricerche Santa Teresa, La Spezia (Italy). Dip. Ambiente; Barsanti, P.; Mione, A.; Posarelli, M. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dip. Ambiente

    1996-12-01

    The acqueous discharges into natural waters is a very technical solution expecially for surface buoyant discharges. It is not only convenient to limit the concentration levels of the discharges, but also to improve the turbolent processes that diluite the discharge. Mostly these processes depend by some geometric parameters of the discharge and by some physical parameters of the effluent and of the receiving water body. An appropriate choice of some parameters, using also suitable mathematical models, allows to design discharges with a very high dilution; so the decreasing of the pollutant levels is improved and the environmental impact can be reduced versus a not diluted effluent. The simulations of a mathematical model, here described, prove that in some circumstances, expecially in case of discharges of fresh water into saline water bodies with a low velocity of the current, the dilution is poor; the effluent can be trapped in a narrow water surface layer where the pollutant concentrations remain high. also far away from the discharge point.

  15. Underwater plasma discharge and its water treatment applications

    Science.gov (United States)

    Ma, Sukhwal; Huh, Jin Young; Kim, Kangil; Hong, Yong Cheol; National Fusion Research Institute Team; Chonbuk National University Team; Kwangwoon University Team; NPAC Team

    2016-09-01

    In recent, the quality of water has been exacerbated by the influx of wastewater and water pollutants. There have been frequent occurrences of water blooms due to the eutrophication of river. Therefore, the needs for water treatment are increased through effective and environment-friendly method. In this work, we propose the plasma system to overcome the problems mentioned above using underwater discharge plasma. The underwater discharges are generated by capillary electrode, and have the advantages of low cost, high efficiency and eco-friendly processing. The proposed technologies can be suitable for eliminating cyanobacteria, decreasing the concentration of oil dissolved in water, and purifying wastewater. Cyanobacteria is killed directly by the underwater discharge and water-dissolved oil and heavy-metal wastewater are purified by coagulation effect, which may result from the chemical reactions of underwater plasma. Consequently, these technologies using underwater discharge can be alternative methods to replace the existing technologies.

  16. Chaos Existence in Surface Discharge of Tracking Test

    Institute of Scientific and Technical Information of China (English)

    DU Boxue; DONG Dianshuai; ZHENG Xiaolei

    2009-01-01

    Tracking tests for different polymer materials were carried out to investigate the chaotic behavior of surface discharge.The discharge sequences measured during the discharge process were analyzed for finding the evidence of chaos existence.Four kinds of nonlinear analysis methods were adopted:estimating the largest Lyapunov exponent,calculating the fractal dimension with increasing the embedding dimension,drawing the recurrence plots,and plotting the Poincare maps.It is found that the largest Lyapunov exponent of the discharge is positive,and the plot of fractal dimension,as a function of embedding dimension,will saturate at a value.The recurrence plots show the chaotic frame-work patterns,and the Poincare maps also have the chaotic characteristics.The results indicate that the chaotic behavior does exist in the discharge currents of the tracking test.

  17. Oil field produced water discharges into wetlands in Wyoming

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Approximately 600 oil field produced water discharges are permitted in Wyoming by the State’s Department of Environmental Quality's (WDEQ) National Pollutant...

  18. Section 11: Surface Water Pathway - Likelihood of Release

    Science.gov (United States)

    Surface water releases can include the threat to targets from overland flow of hazardous substances and from flooding or the threat from the release of hazardous substances to ground water and the subsequent discharge of contaminated ground w

  19. Distribution of biochemical constituents in the surface sediments of western coastal Bay of Bengal: Influence of river discharge and water column properties

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, B.S.K.; Sarma, V.V.S.S.; Krishna, M.S.

    Biochemical composition of surface sediment samples from off major and minor rivers along the east coast of India revealed that spatial distribution of sediment organic carbon (SOC) composition was mainly governed by differential characteristics...

  20. Estimating river discharge from earth observation measurement of river surface hydraulic variables

    Directory of Open Access Journals (Sweden)

    J. Negrel

    2010-10-01

    Full Text Available River discharge is a key variable to quantify the water cycle, its fluxes and stocks at different scales, from local scale for the efficient management of water resource to global scale for the monitoring of climate change. Therefore, developing Earth observation (EO techniques for the measurement or estimation of river discharge is a major challenge. A key question deals with the possibility of deriving river discharge values from EO surface variables (width, level, slope, velocity the only one accessible through EO without any in situ measurement. Based on a literature study and original developments, the possibilities of estimating water surface variables using remote-sensing techniques have been explored, mainly RADAR altimetry as well as across-track and along-track interferometry.

  1. Surface-water surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Saldi, K.A.; Dirkes, R.L.; Blanton, M.L.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the Surface water on and near the Hanford Site is monitored to determine the potential effects of Hanford operations. Surface water at Hanford includes the Columbia River, riverbank springs, ponds located on the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site. Columbia River sediments are also included in this discussion. Tables 5.3.1 and 5.3.2 summarize the sampling locations, sample types, sampling frequencies, and sample analyses included in surface-water surveillance activities during 1994. Sample locations are also identified in Figure 5.3.1. This section describes the surveillance effort and summarizes the results for these aquatic environments. Detailed analytical results are reported by Bisping (1995).

  2. Collective phenomena in volume and surface barrier discharges

    Science.gov (United States)

    Kogelschatz, U.

    2010-11-01

    Barrier discharges are increasingly used as a cost-effective configuration to produce non-equilibrium plasmas at atmospheric pressure. This way, copious amounts of electrons, ions, free radicals and excited species can be generated without significant heating of the background gas. In most applications the barrier is made of dielectric material. Major applications utilizing mainly dielectric barriers include ozone generation, surface cleaning and modification, polymer and textile treatment, sterilization, pollution control, CO2 lasers, excimer lamps, plasma display panels (flat TV screens). More recent research efforts are devoted to biomedical applications and to plasma actuators for flow control. Sinusoidal feeding voltages at various frequencies as well as pulsed excitation schemes are used. Volume as well as surface barrier discharges can exist in the form of filamentary, regularly patterned or diffuse, laterally homogeneous discharges. The physical effects leading to collective phenomena in volume and surface barrier discharges are discussed in detail. Special attention is paid to self-organization of current filaments and pattern formation. Major similarities of the two types of barrier discharges are elaborated.

  3. Surface Water in Hawaii

    Science.gov (United States)

    Oki, Delwyn S.

    2003-01-01

    Surface water in Hawaii is a valued resource as well as a potential threat to human lives and property. The surface-water resources of Hawaii are of significant economic, ecologic, cultural, and aesthetic importance. Streams supply more than 50 percent of the irrigation water in Hawaii, and although streams supply only a few percent of the drinking water statewide, surface water is the main source of drinking water in some places. Streams also are a source of hydroelectric power, provide important riparian and instream habitats for many unique native species, support traditional and customary Hawaiian gathering rights and the practice of taro cultivation, and possess valued aesthetic qualities. Streams affect the physical, chemical, and aesthetic quality of receiving waters, such as estuaries, bays, and nearshore waters, which are critical to the tourism-based economy of the islands. Streams in Hawaii pose a danger because of their flashy nature; a stream's stage, or water level, can rise several feet in less than an hour during periods of intense rainfall. Streams in Hawaii are flashy because rainfall is intense, drainage basins are small, basins and streams are steep, and channel storage is limited. Streamflow generated during periods of heavy rainfall has led to loss of property and human lives in Hawaii. Most Hawaiian streams originate in the mountainous interiors of the islands and terminate at the coast. Streams are significant sculptors of the Hawaiian landscape because of the erosive power of the water they convey. In geologically young areas, such as much of the southern part of the island of Hawaii, well-defined stream channels have not developed because the permeability of the surface rocks generally is so high that rainfall infiltrates before flowing for significant distances on the surface. In geologically older areas that have received significant rainfall, streams and mass wasting have carved out large valleys.

  4. Surface Roughness Effects on Discharge Coefficient of Broad Crested Weir

    Directory of Open Access Journals (Sweden)

    Shaker A. Jalil

    2014-06-01

    Full Text Available The aim of this study is to investigate the effects of surface roughness sizes on the discharge coefficient for a broad crested weirs. For this purpose, three models having different lengths of broad crested weirs were tested in a horizontal flume. In each model, the surface was roughed four times. Experimental results of all models showed that the logical negative effect of roughness increased on the discharge (Q for different values of length. The performance of broad crested weir improved with decrease ratio of roughness to the weir height (Ks/P and with the increase of the total Head to the Length (H/L. An empirical equation was obtained to estimate the variation of discharge coefficient Cd in terms total head to length ratio, with total head to roughness ratio.

  5. A digital procedure for ground water recharge and discharge pattern recognition and rate estimation.

    Science.gov (United States)

    Lin, Yu-Feng; Anderson, Mary P

    2003-01-01

    A digital procedure to estimate recharge/discharge rates that requires relatively short preparation time and uses readily available data was applied to a setting in central Wisconsin. The method requires only measurements of the water table, fluxes such as stream baseflows, bottom of the system, and hydraulic conductivity to delineate approximate recharge/discharge zones and to estimate rates. The method uses interpolation of the water table surface, recharge/discharge mapping, pattern recognition, and a parameter estimation model. The surface interpolator used is based on the theory of radial basis functions with thin-plate splines. The recharge/discharge mapping is based on a mass-balance calculation performed using MODFLOW. The results of the recharge/discharge mapping are critically dependent on the accuracy of the water table interpolation and the accuracy and number of water table measurements. The recharge pattern recognition is performed with the help of a graphical user interface (GUI) program based on several algorithms used in image processing. Pattern recognition is needed to identify the recharge/discharge zonations and zone the results of the mapping method. The parameter estimation program UCODE calculates the parameter values that provide a best fit between simulated heads and flows and calibration head-and-flow targets. A model of the Buena Vista Ground Water Basin in the Central Sand Plains of Wisconsin is used to demonstrate the procedure.

  6. EPA Office of Water (OW): Facilities that Discharge to Water NHDPlus Indexed Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — Discharge of pollutants into waters of the United States is regulated under the National Pollutant Discharge Elimination System (NPDES), a mandated provision of the...

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

  8. Submarine ground-water discharge: nutrient loading and nitrogen transformations

    Science.gov (United States)

    Kroeger, Kevin D.; Swarzenski, Peter W.; Crusius, John; Bratton, John F.; Charette, Matthew A.

    2006-01-01

    Eutrophication of coastal waters due to nonpoint source land-derived nitrogen (N) loads is a worldwide phenomenon and perhaps the greatest agent of change altering coastal ecology (National Research Council, 2000; Howarth and others, 2000). Within the United States, a majority of estuaries have been determined to be moderately to severely impaired by eutrophication associated with increasing nutrient loads (Bricker and others, 1999).In coastal watersheds with soils of high hydraulic conductivity and permeable coastal sediments, ground water is a major route of transport of freshwater and its solutes from land to sea. Freshwater flowing downgradient from aquifers may either discharge from a seepage face near the intertidal zone, or flow directly into the sea as submarine ground-water discharge (SGD) (fig. 1). In the coastal aquifer, entrainment of saline pore water occurs prior to discharge, producing a gradient in ground-water salinity from land to sea, referred to as a subterranean estuary (Moore, 1999). In addition, processes including density-driven flow and tidal pumping create brackish and saline ground-water circulation. Hence, submarine ground-water discharge often consists of a substantial amount of recirculating seawater. Mixing of fresh and saline ground waters in the context of coastal sediments may alter the chemical composition of the discharging fluid. Depending on the biogeochemical setting, removal of fixed N due to processes leading to N2 (dinitrogen gas) production in the nearshore aquifer and subterranean estuary may significantly attenuate land-derived N loads; or, processes such as ion exchange and tidal pumping in the subterranean estuary may substantially accelerate the transport of both land-derived and sediment re-mineralized N to estuarine water columns.As emphasized by Burnett and others (2001, 2002), a fundamental problem in evaluating the importance of ground-water discharge in marine geochemical budgets is the difficulty of collecting

  9. Effects of diaphragm discharge in water solutions containing humic substances

    Science.gov (United States)

    Halamova, Ivana; Stara, Zdenka; Krcma, Frantisek

    2010-01-01

    Preliminary results of research focused on the applications of DC diaphragm discharge in water solutions containing humic substances are presented in this paper. Diaphragm discharge investigated by this work was created in the reactor using constant DC high voltage up to 2 kV that gave the total input power from 100 to 200 W. Presented work investigated decomposition of humic substances by the electric discharge in the dependence of discharge conditions (electrode polarity) as well as solution properties (electrolyte kind, pH). Especially substantial effect of pH on humic acid decomposition has been observed when acidic conditions stimulated the degradation process. Absorption spectroscopy in UV-VIS region together with fluorescence spectroscopy has been used for the detection of changes in humic solutions. Index of humification was calculated from obtained fluorescence spectra and a significant decrease of aromatic components in the humic mixture was determined during the discharge treatment.

  10. Optimization of a Water Window Capillary Discharge Radiation Source

    Directory of Open Access Journals (Sweden)

    M. Stefanovič

    2011-01-01

    Full Text Available Computer modeling of a fast electrical discharge in a nitrogen-filled alumina capillary was performed in order to discover discharge system parameters that lead to high radiation intensity in the so-called water window range of wavelengths (2–4 nm. The modeling was performed by means of the two-dimensional RMHD code Z*. The time and spatial distribution of plasma quantities were used for calculating the ion level populations and for estimating the absorption of the 2.88 nm radiation line in the capillary plasma, using the FLYCHK code. Optimum discharge parameters for the capillary discharge water window source are suggested. The heating of the electrodes and the role of capillary channel shielding were analyzed according to the Z* code.

  11. Discharge Characteristics of DC Arc Water Plasma for Environmental Applications

    Institute of Scientific and Technical Information of China (English)

    LI Tianming; Sooseok CHOI; Takayuki WATANABE

    2012-01-01

    A water plasma was generated by DC arc discharge with a hafnium embedded rodtype cathode and a nozzle-type anode. The discharge characteristics were examined by changing the operation parameter of the arc current. The dynamic behavior of the arc discharge led to significant fluctuations in the arc voltage and its frequency. Analyses of the high speed image and the arc voltage waveform showed that the arc discharge was in the restrike mode and its frequency varied within several tens of kilohertz according to the operating conditions. The larger thermal plasma volume was generated by the higher flow from the forming steam with a higher restrike frequency in the higher arc current conditions. In addition, the characteristics of the water plasma jet were investigated by means of optical emission spectroscopy to identify the abundant radicals required in an efficient waste treatment process.

  12. The effect of water on discharge product growth and chemistry in Li-O2 batteries.

    Science.gov (United States)

    Kwabi, David G; Batcho, Thomas P; Feng, Shuting; Giordano, Livia; Thompson, Carl V; Shao-Horn, Yang

    2016-09-28

    Understanding what controls Li-O2 battery discharge product chemistry and morphology is key to enabling its practical deployment as a low-cost, high-specific-energy energy conversion technology. Several studies have recently shown that the addition of substantial quantities (hundreds to thousands ppm) of water and weak acids to dimethoxyethane (DME)-based electrolytes can significantly increase Li-O2 battery discharge capacity, without substantially changing the discharge product chemistry, which remains Li2O2. The exact mechanisms behind these device-level improvements, however, are not yet understood. In this study, we show that the presence of water in a DME-based electrolyte decreases the rate of Li2O2 nucleation on the electrode surface during Li-O2 battery discharge, using potentiostatic electrochemical measurements, and direct, ex situ observations of Li2O2 particles. We also show that adding water to an acetonitrile (MeCN)-based electrolyte results in LiOH upon discharge, as opposed to only Li2O2. Using first principles calculations, we propose that this change in discharge product chemistry is attributable to increased proton availability, as shown by a lower pKa for water in MeCN than in DME. This study combines kinetic and morphological analyses with first principles calculations, and elucidates relationships among electrolyte composition, discharge product chemistry and growth mechanisms for the rational design of efficient metal-air batteries.

  13. Discharge, water temperature, and water quality of Warm Mineral Springs, Sarasota County, Florida: A retrospective analysis

    Science.gov (United States)

    Metz, Patricia A.

    2016-09-27

    Warm Mineral Springs, located in southern Sarasota County, Florida, is a warm, highly mineralized, inland spring. Since 1946, a bathing spa has been in operation at the spring, attracting vacationers and health enthusiasts. During the winter months, the warm water attracts manatees to the adjoining spring run and provides vital habitat for these mammals. Well-preserved late Pleistocene to early Holocene-age human and animal bones, artifacts, and plant remains have been found in and around the spring, and indicate the surrounding sinkhole formed more than 12,000 years ago. The spring is a multiuse resource of hydrologic importance, ecological and archeological significance, and economic value to the community.The pool of Warm Mineral Springs has a circular shape that reflects its origin as a sinkhole. The pool measures about 240 feet in diameter at the surface and has a maximum depth of about 205 feet. The sinkhole developed in the sand, clay, and dolostone of the Arcadia Formation of the Miocene-age to Oligocene-age Hawthorn Group. Underlying the Hawthorn Group are Oligocene-age to Eocene-age limestones and dolostones, including the Suwannee Limestone, Ocala Limestone, and Avon Park Formation. Mineralized groundwater, under artesian pressure in the underlying aquifers, fills the remnant sink, and the overflow discharges into Warm Mineral Springs Creek, to Salt Creek, and subsequently into the Myakka River. Aquifers described in the vicinity of Warm Mineral Springs include the surficial aquifer system, the intermediate aquifer system within the Hawthorn Group, and the Upper Floridan aquifer in the Suwannee Limestone, Ocala Limestone, and Avon Park Formation. The Hawthorn Group acts as an upper confining unit of the Upper Floridan aquifer.Groundwater flow paths are inferred from the configuration of the potentiometric surface of the Upper Floridan aquifer for September 2010. Groundwater flow models indicate the downward flow of water into the Upper Floridan aquifer

  14. Proposed test method for determining discharge rates from water closets

    DEFF Research Database (Denmark)

    Nielsen, V.; Fjord Jensen, T.

    At present the rates at which discharge takes place from sanitary appliances are mostly known only in the form of estimated average values. SBI has developed a measuring method enabling determination of the exact rate of discharge from a sanitary appliance as function of time. The methods depends...... on the application of a calibrated measuring vessel, the volume of water in the vessel being measured at a given moment by means of a transducer and recorded by an UV recorder which is able to follow very rapid variations. In the article the apparatus is described in detail, and an example is given...... of the measurements of the rate of discharge from a WC....

  15. Pulsed electrical discharge in gas bubbles in water

    Science.gov (United States)

    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

  16. All solid state pulsed power system for water discharge

    OpenAIRE

    Sakugawa, Takashi; Yamaguchi, Takahiro; Yamamoto, Kunihiro; Kiyan, Tsuyoshi; Namihira, Takao; Katsuki, Sunao; Akiyama, Hidenori; サクガワ, タカシ; ヤマグチ, タカヒロ; ヤマモト, クニヒロ; キヤン, ツヨシ; ナミヒラ, タカオ; カツキ, スナオ; アキヤマ, ヒデノリ; 佐久川, 貴志

    2005-01-01

    Pulsed power has been used to produce non-thermal plasmas in gases that generate a high electric field at the tip of streamer discharges, where high energy electrons, free radicals, and ozone are produced. Recently, all solid state pulsed power generators, which are operated with high repetition rate, long lifetime and high reliability, have been developed for industrial applications, such as high repetition rate pulsed gas lasers, high energy density plasma (EUV sources) and water discharges...

  17. Observation of OH radicals produced by pulsed discharges on the surface of a liquid

    Science.gov (United States)

    Kanazawa, Seiji; Kawano, Hirokazu; Watanabe, Satoshi; Furuki, Takashi; Akamine, Shuichi; Ichiki, Ryuta; Ohkubo, Toshikazu; Kocik, Marek; Mizeraczyk, Jerzy

    2011-06-01

    The hydroxyl radical (OH) plays an important role in plasma chemistry at atmospheric pressure. OH radicals have a higher oxidation potential compared with other oxidative species such as free radical O, atomic oxygen, hydroperoxyl radical (HO2), hydrogen peroxide(H2O2) and ozone. In this study, surface discharges on liquids (water and its solutions) were investigated experimentally. A pulsed streamer discharge was generated on the liquid surface using a point-to-plane electrode geometry. The primary generation process of OH radicals is closely related to the streamer propagation, and the subsequent secondary process after the discharge has an influence on the chemical reaction. Taking into account the timescale of these processes, we investigated the behavior of OH radicals using two different diagnostic methods. Time evolution of the ground-state OH radicals above the liquid surface after the discharge was observed by a laser-induced fluorescence (LIF) technique. In order to observe the ground-state OH, an OH [A 2∑+(v' = 1) gas phase to the liquid surface and dissolved in the liquid. These dissolved OH radicals were measured by a chemical probe method. Terephthalic acid was used as an OH radical trap and fluorescence of the resulting 2-hydroxyterephthalic acid was measured. This paper directly presents visualization of OH radicals over the liquid surface by means of LIF, and indirectly describes OH radicals dissolved in water by means of a chemical method.

  18. Quantitative relationship between the maximum streamer length and discharge voltage of a pulsed positive streamer discharge in water

    Science.gov (United States)

    Wen, Xiaoqiong; Li, Qian; Li, Jingsen; Ren, Chunsheng

    2017-08-01

    A linear relationship has been realized between the maximum streamer length and discharge voltage of a pulsed positive streamer discharge by measuring the streamer length in water with conductivity of 100 μS cm-1 using high-speed photography. Based on Ohm’s law, a quantitative equation has been derived for the dependence of the maximum streamer length on the discharge voltage of a pulsed positive streamer discharge in water. According to the equation, our results suggest that the streamers spontaneously stop propagating through water due to the voltage at the streamer head dropping below the ignition voltage of a pulsed positive streamer discharge.

  19. Water Transport Models of Moisture Absorption and Sweat Discharge Yarns

    Institute of Scientific and Technical Information of China (English)

    WANG Fa-ming; ZHOU Xiao-hong; WANG Shan-yuan

    2008-01-01

    An important property of moisture absorption and sweat discharge yams is their water transport property. In the paper, two water transport models of moisture absorption and sweat discharge yams were developed to investigate the influence factors on their wicking rate. In parallel Column Pores Model, wicking rate is determined by the equivalent capillary radius R and length of the capillary tube L. In Pellets Accumulation Model, wicking rate is decided by the capillary radius r and length of the fiber unit assemble L0.

  20. Enhanced osteoblast response to electrical discharge machining surface.

    Science.gov (United States)

    Otsuka, Fukunaga; Kataoka, Yu; Miyazaki, Takashi

    2012-01-01

    The purpose of this study is to investigate the surface characteristics and biocompatibility of titanium (Ti) surfaces modified by wire electrical discharge machining (EDM). EDM surface characteristics were evaluated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), thin-film X-ray diffractometry (XRD) and contact angle measurements. MC3T3-E1 cell morphology, attachment and proliferation, as well as analysis of osteoblastic gene expressions, on machined surfaces and EDM surfaces were also evaluated. EDM surfaces exhibited high super hydrophilicity, due to high surface energy. XPS and XRD revealed that a passive oxide layer with certain developing thickness onto. EDM surfaces promoted cell attachment, but restrained proliferation. Counted cell numbers increased significantly on the machined surfaces as compared to the EDM surfaces. Real-time PCR analyses showed significantly higher relative mRNA expression levels of osteoblastic genes (ALP, osteocalcin, Runx2, Osterix) in cells cultured on the EDM surfaces as compared to cells cultured on the machined surfaces.

  1. Research on Discharge Circuit of Electro-Hydraulic Power Impulse Water Jets

    Science.gov (United States)

    Wang, Zhaohui; Gao, Quanjie; Wang, Wei; Liao, Zhenfang

    2012-01-01

    Electro-hydraulic power impulse water jets can convert the shock wave generated in the liquid by discharging into mechanical energy, and it has been widely used in material forming, surface cleaning, pipeline dirt cleaning and ore breaking process. Compared with the traditional high pressure water jets, the energy utilization of electro-hydraulic power impulse water jets is up to 80% while the water consumption is reduced by 40-55%. This paper has taken electro-hydraulic power impulse water jets as the research object, employed obtaining the maximum pressure of compression impulse matrix surface as the research goal, studied in depth the equivalent discharge circuit, characteristic equation and the relationship between the electrical parameters of the electro-hydraulic power impulse discharge circuit and built the calculation method of the voltage, the inductance, the capacitance and the electrode spacing parameter of electro-hydraulic power impulse water jets discharge circuit. So, it will provide important theoretical basis for further studies of electro-hydraulic power impulse technology and the existing water jets device.

  2. Assessment of the Water Quality from the Sitnica River as a Result of Urban Discharges

    Directory of Open Access Journals (Sweden)

    ALBONA SHALA

    2015-10-01

    Full Text Available According to the Ministry of Environment and Spatial Planning, Kosovo is facing problems related not only to the limited amount of water, but also when it comes to its quality, as a result of discharge of contaminated wastewater into the surface and groundwater, without any prior treatment. The longest river (90km and at the same time the most polluted river in Kosovo is the Sitnica River. All the wastewater from the towns and villages washed by this river during its entire watercourse from its source until its mouth into the Ibar River is discharged into this river. In order to have a more accurate overview of the impact of urban discharge into the quality of the Sitnica River water and to assess the impact of the pollutants discharged into this river, we conducted a research at five monitoring stations: the first station representing a reference station not being subjected (untouched to anthropogenic pollution pressure while the other four represent monitoring stations situated at water area affected by this discharge of urban wastewater. The purpose of this study is to assess the quality of the Sitnica River water and to analyze the pollution scale level throughout its course caused by urban discharge. Some of the parameters of the water qualityanalyzed are: temperature, turbidity, electrical conductivity, pH, DO, COD, BOD, P total, nitrates, detergents and ammonium ions.Analysis of the physical – chemical parameters of the water quality was conducted at the laboratory of the Hydro-meteorological Institute of Kosovo. Based on experimental results, various readings of the majority of the studied parameters were obtained at different stations with a tendency of deteriorated quality of water with the growing distance from the source of the Sitnica River, as a result of continuous impact of pollution. From our findings we can conclude that continuous discharge of urban wastewater has a considerable impact on the quality of the Sitnica River

  3. Surface Treatment of Polyethylene Terephthalate Film Using Atmospheric Pressure Glow Discharge in Air

    Institute of Scientific and Technical Information of China (English)

    方志; 邱毓昌; 王辉

    2004-01-01

    Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted.The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the surface oxygen content of PET surface increases to 39%, and the water contact angle decreases to 19°, respectively.

  4. Water on graphene surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gordillo, M C [Departamento de Sistemas Fisicos, Quimicos y Naturales, Facultad de Ciencias Experimentales, Universidad Pablo de Olavide, Carretera de Utrera, km 1, E-41013 Sevilla (Spain); Marti, J, E-mail: cgorbar@upo.e, E-mail: jordi.marti@upc.ed [Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, B4-B5 Campus Nord, E-08034 Barcelona, Catalonia (Spain)

    2010-07-21

    In this paper, we summarize the main results obtained in our group about the behavior of water confined inside or close to different graphene surfaces by means of molecular dynamics simulations. These include the inside and outside of carbon nanotubes, and the confinement inside a slit pore or a single graphene sheet. We paid special attention to some thermodynamical (binding energies), structural (hydrogen-bond distributions) and dynamic (infrared spectra) properties, and their comparison to their bulk counterparts.

  5. Surface charge dynamics and OH and H number density distributions in near-surface nanosecond pulse discharges at a liquid / vapor interface

    Science.gov (United States)

    Winters, Caroline; Petrishchev, Vitaly; Yin, Zhiyao; Lempert, Walter R.; Adamovich, Igor V.

    2015-10-01

    The present work provides insight into surface charge dynamics and kinetics of radical species reactions in nanosecond pulse discharges sustained at a liquid-vapor interface, above a distilled water surface. The near-surface plasma is sustained using two different discharge configurations, a surface ionization wave discharge between two exposed metal electrodes and a double dielectric barrier discharge. At low discharge pulse repetition rates (~100 Hz), residual surface charge deposition after the discharge pulse is a minor effect. At high pulse repetition rates (~10 kHz), significant negative surface charge accumulation over multiple discharge pulses is detected, both during alternating polarity and negative polarity pulse trains. Laser induced fluorescence (LIF) and two-photon absorption LIF (TALIF) line imaging are used for in situ measurements of spatial distributions of absolute OH and H atom number densities in near-surface, repetitive nanosecond pulse discharge plasmas. Both in a surface ionization wave discharge and in a double dielectric barrier discharge, peak measured H atom number density, [H] is much higher compared to peak OH number density, due to more rapid OH decay in the afterglow between the discharge pulses. Higher OH number density was measured near the regions with higher plasma emission intensity. Both OH and especially H atoms diffuse out of the surface ionization wave plasma volume, up to several mm from the liquid surface. Kinetic modeling calculations using a quasi-zero-dimensional H2O vapor / Ar plasma model are in qualitative agreement with the experimental data. The results demonstrate the experimental capability of in situ radical species number density distribution measurements in liquid-vapor interface plasmas, in a simple canonical geometry that lends itself to the validation of kinetic models.

  6. Study on hexagonal super-lattice pattern with surface discharges in dielectric barrier discharge

    Science.gov (United States)

    Liu, Ying; Dong, Lifang; Niu, Xuejiao; Gao, Yenan; Zhang, Chao

    2015-10-01

    The hexagonal super-lattice pattern with surface discharges (SDs) in dielectric barrier discharge is investigated by intensified charge-coupled device. The pattern is composed of the bright spot and the dim spot which is located at the centroid of surrounding other three bright spots. The phase diagram of the pattern as a function of the gas pressure and the argon concentration is given. The instantaneous images indicate that the bright spot emerging at the front of the current pulse is formed by the volume discharge (VD), and dim spot occurring at the tail of the current pulse is formed by the SD. The above result shows that the SD is induced by the VD. The simulation of the electric fields of wall charges accumulated by VDs confirms that the dim spot is formed by the confluences of the SDs of surrounding other three bright spots. By using optical emission spectrum method, both the molecule vibration temperature and electron density of the SD are larger than that of the VD.

  7. EPA Enforcement and Compliance History Online: Water Discharge Monitoring Report Data Sets for FY2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report (DMR) data sets for Clean Water...

  8. EPA Enforcement and Compliance History Online: Water Discharge Monitoring Report Data Sets for FY2015

    Data.gov (United States)

    U.S. Environmental Protection Agency — Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report (DMR) data sets for Clean Water...

  9. EPA Enforcement and Compliance History Online: Water Discharge Monitoring Report Data Sets for FY2014

    Data.gov (United States)

    U.S. Environmental Protection Agency — Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report (DMR) data sets for Clean Water...

  10. EPA Enforcement and Compliance History Online: Water Discharge Monitoring Report Data Sets for FY2016

    Data.gov (United States)

    U.S. Environmental Protection Agency — Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report (DMR) data sets for Clean Water...

  11. EPA Enforcement and Compliance History Online: Water Discharge Monitoring Report Data Sets for FY2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report (DMR) data sets for Clean Water...

  12. EPA Enforcement and Compliance History Online: Water Discharge Monitoring Report Data Sets for FY2009

    Data.gov (United States)

    U.S. Environmental Protection Agency — Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report (DMR) data sets for Clean Water...

  13. EPA Enforcement and Compliance History Online: Water Discharge Monitoring Report Data Sets for FY2010

    Data.gov (United States)

    U.S. Environmental Protection Agency — Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report (DMR) data sets for Clean Water...

  14. EPA Enforcement and Compliance History Online: Water Discharge Monitoring Report Data Sets for FY2012

    Data.gov (United States)

    U.S. Environmental Protection Agency — Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report (DMR) data sets for Clean Water...

  15. Surface Water Data at Los Alamos National Laboratory 2000 Water Year

    Energy Technology Data Exchange (ETDEWEB)

    D.A.Shaull; M.R.Alexander; R.P.Reynolds; R.P.Romero; E.T.Riebsomer; C.T.McLean

    2001-06-02

    The principal investigators collected and computed surface water discharge data from 23 stream-gaging stations that cover most of Los Alamos National Laboratory and one at Bandelier National Monument. Also included are discharge data from three springs, two that flow into Canon del Valle and one that flows into Water Canyon.

  16. Surface Water Data at Los Alamos National Laboratory: 2002 Water Year

    Energy Technology Data Exchange (ETDEWEB)

    D.A. Shaull; D. Ortiz; M.R. Alexander; R.P. Romero

    2003-03-03

    The principal investigators collected and computed surface water discharge data from 34 stream-gaging stations that cover most of Los Alamos National Laboratory and one at Bandelier National Monument. Also included are discharge data from three springs--two that flow into Canon de Valle and one that flows into Water Canyon--and peak flow data from 16 stations.

  17. Surface Water Data at Los Alamos National Laboratory: 1999 Water Year

    Energy Technology Data Exchange (ETDEWEB)

    D. A. Shaull; M. R. Alexander; R. P. Reynolds; C. T. McLean; R. P. Romero

    2000-04-01

    The principal investigators collected and computed surface water discharge data from 22 stream-gaging stations that cover most of Los Alamos National Laboratory with one at Bandelier National Monument. Also included are discharge data from three springs that flow into Canon de Valle and nine partial-record storm water stations.

  18. Surface water data at Los Alamos National Laboratory: 2008 water year

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, David; Cata, Betsy; Kuyumjian, Gregory

    2009-09-01

    The principal investigators collected and computed surface water discharge data from 69 stream-gage stations that cover most of Los Alamos National Laboratory and one at Bandelier National Monument. Also included are discharge data from three springs— two that flow into Cañon de Valle and one that flows into Water Canyon.

  19. Surface Water Data at Los Alamos National Laboratory 2006 Water Year

    Energy Technology Data Exchange (ETDEWEB)

    R.P. Romero, D. Ortiz, G. Kuyumjian

    2007-08-01

    The principal investigators collected and computed surface water discharge data from 44 stream-gaging stations that cover most of Los Alamos National Laboratory and one at Bandelier National Monument. Also included are discharge data from three springs--two that flow into Canon de Valle and one that flows into Water Canyon--and peak flow data for 44 stations.

  20. Surface water data at Los Alamos National Laboratory: 2008 water year

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, David; Cata, Betsy; Kuyumjian, Gregory

    2009-09-01

    The principal investigators collected and computed surface water discharge data from 69 stream-gage stations that cover most of Los Alamos National Laboratory and one at Bandelier National Monument. Also included are discharge data from three springs— two that flow into Cañon de Valle and one that flows into Water Canyon.

  1. Surface water data at Los Alamos National Laboratory: 2009 water year

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, David; McCullough, Betsy

    2010-05-01

    The principal investigators collected and computed surface water discharge data from 73 stream-gage stations that cover most of Los Alamos National Laboratory and one at Bandelier National Monument. Also included are discharge data from three springs— two that flow into Cañon de Valle and one that flows into Water Canyon.

  2. Trans-Himalayan water contributions to river discharge

    Science.gov (United States)

    Andermann, Christoff; Stieglitz, Thomas; Schuessler, Jan A.; Parajouli, Binod

    2017-04-01

    -defined diurnal cycles in water temperature, stage level and water chemistry. These diurnal cycles have a profound impact on the chemical concentrations and need to be corrected for to estimate representative geochemical fluxes for the full river and end member mixing modeling. Radon and trace element data indicate that groundwater contributions are primarily associated with the main tectonic structures of the Himalayan range, but also concentrate on the steep southern mountain front, and that groundwater outflow from the Lesser Himalayas is limited during baseflow season. Over the seasons the chemical dilution signature across the Himalayan range is persistent. However, specific elements have temporally distinct dilution signatures highlighting the alternating contribution of different hydrological compartments over the annual hydrological cycle. Our analysis allows to decipher the hydrological contribution of different water reservoirs to the surface water discharge in rivers, along a major Himalayan stream. Our results highlight the volumetric importance of a high mountain deep-groundwater storage compartment across the Himalayan mountain belt and provides first order quantification of groundwater contribution to stream flow.

  3. FAST TRACK COMMUNICATION: Small surface wave discharge at atmospheric pressure

    Science.gov (United States)

    Kiss'ovski, Zh; Kolev, M.; Ivanov, A.; Lishev, St.; Koleva, I.

    2009-09-01

    A small surface wave driven source produces plasma at atmospheric pressure. Microwave power at frequency 2.45 GHz is coupled with the source and a discharge is ignited at power levels below 10 W. The coaxial exciter of the surface waves has a length of 10 mm because its dielectric is a high permittivity discharge tube. The plasma source operates as a plasma jet in the case of plasma columns longer than the tube length. The source maintains stable plasma columns over a wide range of neutral gas flow and applied power in continuous and pulse regimes. An additional advantage of this source is the discharge self-ignition. An electron temperature of Te ~ 1.9 eV and a density of ne ~ 3.9 × 1014 cm-3 are estimated by the probe diagnostics method. The emission spectra in the wavelength range 200-1000 nm under different experimental conditions are analysed and they prove the applicability of the source for analytical spectroscopy. The dependences of column length, reflected power and plasma parameters on the gas flow and the input power are discussed.

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

    Science.gov (United States)

    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.

  5. Remarkable impact of water on the discharge performance of a silicon-air battery.

    Science.gov (United States)

    Cohn, Gil; Macdonald, Digby D; Ein-Eli, Yair

    2011-08-22

    Here, we report on a Si-air/ionic liquid electrolyte battery whose performance improves with small amounts of water in the electrolyte. The shift of the generation zone of the SiO(2) discharge product from the air cathode surface into the bulk region of the liquid electrolyte, caused by water addition, is demonstrated through various means. Addition of 15 vol% water leads to an increase of 40% in the discharge capacity as compared to the capacity obtained using a pure ionic liquid electrolyte. If the water content increases above 20 vol%, the Si-air cell capacity dramatically decreases. The water-ionic liquid electrolyte mixture shows a maximum in the ionic conductivity with a water content of 10 vol%. In-depth studies indicate a reduced amount of discharge product at the air electrode using 15 vol% H(2)O electrolyte. The morphology of the anode surface, as well as the developed surface film in the presence of water-containing ionic liquid, is reported. This study shows that exposing a Si-air battery to a humid environment does not result in capacity losses, but rather improves cell performance.

  6. Effect of land use change on water discharge in Srepok watershed, Central Highland, Viet Nam

    Directory of Open Access Journals (Sweden)

    Nguyen Thi Ngoc Quyen

    2014-09-01

    Full Text Available Srepok watershed plays an important role in Central Highland in Viet Nam. It impacts to developing social-economic conditions. Therefore, it is necessary to research elements which impact to natural resources in this watershed. The Soil and Water Assessment Tool (SWAT model and Geography Information System (GIS were used to simulate water discharge in the Srepok watershed. The objectives of the research were to apply GIS and SWAT model for simulation water discharge and then, we assessed land use change which impacted on water discharge in the watershed. The observed stream flow data from Ban Don Stream gauge station was used to calibrate for the period from 1981 to 2000 and then validate for the period from 2001 to 2009. After using SWAT-CUP software to calibration, NSI reached 0.63 and R square value achieved 0.64 from 2004 to 2008 in calibration and NSI gained good level at 0.74 and R square got 0.75 from 2009 to 2012 in validation step at Ban Don Station. After that, land cover in 2010 was processed like land cover in 2000 and set up SWAT model again. The simulated water discharge in scenario 1 (land use 2000 was compared with scenario 2 (land use 2010, the simulation result was not significant difference between two scenarios because the change of area of land use was not much enough to affect the fluctuation of water discharge. However, the effect of land cover on water resource could be seen clearly via total water yield. The percentage of surface flow in 2000 was twice times more than in 2010; retard and base flow in 2000 was slightly more than in 2010. Therefore, decreased surface flow, increased infiltration capacity of water and enriched base flow resulted in the growth of land cover.

  7. Atmospheric pressure dielectric barrier discharges for sterilization and surface treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chin, O. H.; Lai, C. K.; Choo, C. Y.; Wong, C. S.; Nor, R. M. [Plasma Technology Research Centre, Physics Department, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Thong, K. L. [Microbiology Division, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-04-24

    Atmospheric pressure non-thermal dielectric barrier discharges can be generated in different configurations for different applications. For sterilization, a parallel-plate electrode configuration with glass dielectric that discharges in air was used. Gram-negative bacteria (Escherichia coli and Salmonella enteritidis) and Gram-positive bacteria (Bacillus cereus) were successfully inactivated using sinusoidal high voltage of ∼15 kVp-p at 8.5 kHz. In the surface treatment, a hemisphere and disc electrode arrangement that allowed a plasma jet to be extruded under controlled nitrogen gas flow (at 9.2 kHz, 20 kVp-p) was applied to enhance the wettability of PET (Mylar) film.

  8. Optical emission spectrum of filamentary nanosecond surface dielectric barrier discharge

    Science.gov (United States)

    Shcherbanev, S. A.; Khomenko, A. Yu; Stepanyan, S. A.; Popov, N. A.; Starikovskaia, S. M.

    2017-02-01

    Streamer-to-filament transition is a general feature of high pressure high voltage (HV) nanosecond surface dielectric barrier discharges. The transition was studied experimentally using time- and space-resolved optical emission in UV and visible parts of spectra. The discharge was initiated by HV pulses 20 ns in duration and 2 ns rise time, positive or negative polarity, 20-60 kV in amplitude on the HV electrode. The experiments were carried out in a single-shot regime at initial pressures P  >  3 bar and ambient initial temperature in air, N2, H2:N2 and O2:Ar mixtures. It was shown that the transition to filamentary mode is accompanied by the appearance of intense continuous radiation and broad atomic lines. Electron density calculated from line broadening is characterized by high absolute values and long decay in the afterglow. The possible reasons for the continuous spectra were analyzed.

  9. Design of Water Network with Multiple Contaminants and Zero Discharge

    Institute of Scientific and Technical Information of China (English)

    李英; 都健; 姚平经

    2003-01-01

    The paper presents a procedure to design water network. First of all, water reuse system, water regeneration reuse system (including regeneration recycle) and wastewater treatment system are designed separately.But the interaction between different parts demands that each part is designed iteratively to optimize the whole water network. Therefore, on the basis of the separated design a water network superstructure including reuse,regeneration and wastewater treatment is established from the system engineering point of view. And a multiobjective adaptive simulated annealing genetic algorithm is adopted to simultaneously integrate the overall water network to balance the economic and environmental effects. The algorithm overcomes the defect of local optimum of simulated annealing (SA), avoids the pre-maturation of genetic algorithm (GA) and finds a set of solutions (pareto front) in acceptable computer time. From the pareto front, a point with minimum fresh water consumption will be extended to zero discharge as our ultimate goal.

  10. Surface Modification of Polyethylene (PE) Films Using Dielectric Barrier Discharge Plasma at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    WANG Kun; LI Jian; REN Chunsheng; WANG Dezhen; WANG Younian

    2008-01-01

    Modification of the surface properties of polyethylene (PE) films is studied using air dielectric barrier discharge at atmospheric pressure. The treated samples are examined by water contact angle measurements, Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). With the increase in treating time, the water contact angle changes from 93.2° before treatment to a minimum of 53.3° after a treatment for 50 s. Both ATR and XPS results show some oxidized" species are introduced into the sample surface by the plasma treatment and the tendency of the water contact angle with the treating time is the same as that of oxygen concentration on the treated sample surface. SEM result shows the surface roughness of PE samples increases with the treatment time increasing.

  11. Design of Water Discharge of Medewi Watershed Using Avswat Model

    Science.gov (United States)

    Pramana, Y. H.; Purwanto, B. P.

    2013-12-01

    Medewi watersheds is located in the southern of Bali Island and its estuary is located in Medewi Beach at Kabupaten Jembrana. The exact location of Medewi watersheds is between Desa Medewi and Desa Pulukan, Kecamatan Pekutatan, Kabupaten Jembrana. The watersheds itself, due to its strategic location is used as a territorial border between the two villages. Geographically, Medewi watersheds is between 114o48'00' - 114o50'00' east longitude and 08o20'00' - 08o26,5'00' south latitude. The main river of Medewi Watersheds is 25,64 km long and is classified as a continuous river, the width of the watersheds itself is measured 128,2 km2. Medewi watersheds have two tributaries which is Medaan watersheds and Pangliman watersheds, both watersheds' heads are located in Medewi Beach. Medewi watersheds is often flooded and brings heavy toll to its surrounding areas and citizen. Therefore, there is an urgent need to perform engineering techniques to overcome the aforementioned problem. However, there is a slight issue in the definition of water discharge plan in the location. The water discharge plan, which is used as a basis to prevent flooding, is often inaccurate. That is the reason why it is needed to build a model in order to accurately find out the amount of water discharge in the study location. Medewi watersheds' area usage is as follow: bushes (9,44%), forestation (77,10%), farm (7,76%), settlement (2,15%), irrigation field (1,64%), rainfed field (1,88%) and crops field (0,48%). The result of our modeling using ASVAT shows that the maximum water discharge is 149,9 m3/sec. The discharge is calibrated with the available water discharge data log. According to AWLR data, it is known that the largest discharge occurred on June 2nd, 2009 and measured at 147,9 m3/sec. Our conclusion is that the model used in this study managed to approach the field result with minimum error.

  12. Degradation of dyes by active species injected from a gas phase surface discharge

    Science.gov (United States)

    Li, Jie; Wang, Tiecheng; Lu, Na; Zhang, Dandan; Wu, Yan; Wang, Tianwei; Sato, Masayuki

    2011-06-01

    A reactor, based on the traditional gas phase surface discharge (GPSD), is designed for degradation of dye wastewater in this study. The reactor is characterized by using the dye wastewater as a ground electrode. A spiral discharge electrode of stainless steel wire attached on the inside wall of a cylindrical insulating medium and the wastewater surrounding the insulating medium for simultaneous cooling of the discharge electrode constitute the reactor. The active chemical radicals generated by the discharge of the spiral electrode are injected into the water with the carrier gas. The removal of three organic dyes (including methyl red (MR), reactive brilliant blue (RBB) and cationic red (CR)) in aqueous solution is investigated. The effects of electrode configuration, discharge voltage and solution pH value on the decoloration efficiency of MR are discussed. The experimental results show that over 95% of decoloration efficiencies for all the dyes are obtained after several minutes of plasma treatment. 40% of chemical oxygen demand removal of MR is obtained after 8 min of discharge treatment. Furthermore, it is found that ozone mainly affects the removal of dyes and several aliphatic compounds are identified as the oxidation products of MR. The possible degradation pathways of MR by GPSD are proposed.

  13. Degradation of dyes by active species injected from a gas phase surface discharge

    Energy Technology Data Exchange (ETDEWEB)

    Li Jie; Wang Tiecheng; Lu Na; Zhang Dandan; Wu Yan; Wang Tianwei [Institute of Electrostatic and Special Power, Dalian University of Technology, Dalian 116024 (China); Sato, Masayuki, E-mail: lijie@dlut.edu.cn [Department of Chemical and Environmental Engineering, Gunma University, Kiryu, Tenjin-cho 1-5-1, 376-8515 (Japan)

    2011-06-15

    A reactor, based on the traditional gas phase surface discharge (GPSD), is designed for degradation of dye wastewater in this study. The reactor is characterized by using the dye wastewater as a ground electrode. A spiral discharge electrode of stainless steel wire attached on the inside wall of a cylindrical insulating medium and the wastewater surrounding the insulating medium for simultaneous cooling of the discharge electrode constitute the reactor. The active chemical radicals generated by the discharge of the spiral electrode are injected into the water with the carrier gas. The removal of three organic dyes (including methyl red (MR), reactive brilliant blue (RBB) and cationic red (CR)) in aqueous solution is investigated. The effects of electrode configuration, discharge voltage and solution pH value on the decoloration efficiency of MR are discussed. The experimental results show that over 95% of decoloration efficiencies for all the dyes are obtained after several minutes of plasma treatment. 40% of chemical oxygen demand removal of MR is obtained after 8 min of discharge treatment. Furthermore, it is found that ozone mainly affects the removal of dyes and several aliphatic compounds are identified as the oxidation products of MR. The possible degradation pathways of MR by GPSD are proposed.

  14. Inactivation of Staphylococcus aureus in water by pulsed spark discharge.

    Science.gov (United States)

    Zheng, Jiansheng

    2017-09-04

    A pulsed spark plasma discharge system was developed and tested as an energy efficient water sterilization method. A 5 log10 reduction on Staphylococcus aureus concentration of 10(8) CFU/ml was obtained. Complete inactivation was achieved for concentration of 10(6) CFU/ml. Of the various factors generated by an underwater spark discharge, ultraviolet radiation plays a major role. The inactivation was completely suppressed by the addition of 30 mg/L of a soluble sunscreen, Benzophenone-9. Results obtained using the pulsed spark plasma discharge showed that this system has several advantages, such as high energy efficiency, absence of harmful by-products and portability, over the conventional sterilization methods.

  15. Diagnostics of Atmospheric Pressure Surface Discharge Plasmas in Argon

    Institute of Scientific and Technical Information of China (English)

    张锐; 詹如娟; 温晓辉

    2003-01-01

    Atmospheric pressure surface discharge is shown to have great prospects for a number of industrial applications.To acquire better results in application fields and considering that the study of the basic parameters including electron temperature and electron density is desirable,we develop an equivalent circuit model and the diagnostic techniques based on optical emission spectroscopy and electrical measurement in our laboratory.The electron temperature has been determined to be about 0.7eV by a Fermi-Dirac model.The electron density has been calculated to be near 1010 cm-3 from a time resolved electrical measurement(Ohmic heating method).

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

    Directory of Open Access Journals (Sweden)

    Jingan Chen

    Full Text Available 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.

  17. Discharge and Treatment of Waste Water in Denmark

    DEFF Research Database (Denmark)

    Larsen, Torben

    1990-01-01

    a population of 70.000 inhabitans, and waste water treatment takes place in two treatment plants. These plants are now being extended to perform tertiary treatment, to fulfil the new Danish requirements. From 1992, the maximum average concentrations allowed for municipal waste water discharges to receiving...... waters will be; 15 mg/1 for BOD5, 8 mg/1 for total nitrogen, and 1.5 mg/1 for total phosphorus. These general requirements cover all types of receiving waters, but regional authorities have, in a number of cases, fixed lower values for sensitive areas.......This paper describes the waste water treatment situation in the area of Esbjerg. This example was chosen because the situation in Esbjerg is typical of that of most towns in Denmark, and because Esbjerg is closest to the British situation with respect to the receiving water. Esbjerg has...

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

    Science.gov (United States)

    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.

  19. Submittal of SWMU Assessment Report for Building 9960 Surface Discharge

    Energy Technology Data Exchange (ETDEWEB)

    Dotson, Patrick Wells [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    Sandia National Laboratories is a multi-purpose engineering and science laboratory owned by the U.S. Department of Energy (DOE)/National Nuclear Security Administration and managed and operated by Sandia Corporation (Sandia), a wholly-owned subsidiary of Lockheed Martin Corporation. This Solid Waste Management Unit (SWMU) Assessment Report (SAR) for the Sandia National Laboratories, New Mexico (SNL/NM), Coyote Test Field, Building 9960 Surface Discharge, has been prepared in accordance with Section V of the Compliance Order on Consent (the Consent Order) between the New Mexico Environment Department (NMED), DOE, and Sandia (NMED April 2004). The DOE and Sandia formally notified the NMED of this newly identified or suspected SWMU or Area of Concern (AOC) by letter dated December 9, 2014. This SAR is being submitted in accordance with the NMED Hazardous Waste Bureau (HWB) letter dated February 16, 2015 letter (Kieling February 2015). This SAR presents the available information for the Building 9960 Surface Discharge, including location, designation of type and function, a general description, the operational dates, waste characteristics, and a summary of existing analytical wastewater and soil data

  20. Analysis of uncertainties, associated to the calculating hypothesis, in discharge tables for high flows estimating, based on mathematics models for calculating water surface profiles fore steady gradually varied flow; Analisis de las incertidumbres, asociadas a las hipotesis de calculo, en la estimacion de curvas de gasto para crcidas, basada en el empleo de modelo matematico de calculo hidraulico en regimen permanente

    Energy Technology Data Exchange (ETDEWEB)

    Aldana Valverde, A. L.; Gonzalez Rodriguez, J. C.

    1999-08-01

    In this paper are analyzed some of the most important factors which can influence on the results of calculating water surface profiles for steady gradually varied flow. In this case, the objective of this kind of modeling, has been the estimation of discharges tables for high flows of river station gages connected to the hydrologic automatic information system (SAIH) of the Confederacion Hidrografica del Sur de Espana, system named red Hidrosur. (Author) 3 refs

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. HYDRAULIC CHARACTERISTICS OF WATER-WINGS FOR THE MIDDLE-PIER OF A DISCHARGE TUNNEL

    Institute of Scientific and Technical Information of China (English)

    WU Jian-hua; CAI Chang-guang; JI Wei; RUAN Shi-ping

    2006-01-01

    Water-wings, induced by the middle-pier placed in the inlet of a discharge tunnel, have harmful effects on the operation of the discharge tunnel.Based on dimensional analysis and physical model tests, the hydraulic characteristics of water-wings were investigated and their causes were analyzed in this study.The results show that the height and length of the water-wings increased with the increase of three factors, i.e., the Froude number Frd of the outlet of the pressure section, the depth Hc of the water surface concave at the end of the middle-pier, and the impact length Li of the two flows after this end.

  3. Optical Emission Spectroscopic Measurement of Hydroxyl Radicals in Air Discharge with Atomized Water%Optical Emission Spectroscopic Measurement of Hydroxyl Radicals in Air Discharge with Atomized Water

    Institute of Scientific and Technical Information of China (English)

    孙明; 陈维刚; 张颖

    2011-01-01

    Effects of discharge mode, voltage applied, size of the nozzle discharge electrode and flow rate of water on the generation of hydroxyl radical were investigated in air discharge with atomized water, by using optical emission spectroscopy (OES). Water was injected into the discharge region through the discharge nozzle electrode, and a large amount of fine water drops, formed and distributed in the discharge region, corona discharge was more effective to generate were observed. It was found that negative DC the hydroxyl radicals in comparison to positive DC corona discharge or negative pulsed discharge. A larger outer diameter of the nozzle electrode or a stronger electric field is beneficial for hydroxyl-radical generation. Moreover, there is a critical value in the flow rate of atomized water against the discharge voltage. Below this critical value, hydroxyl-radical generation increases with the increase in flow rate of the water, while above this value, it decreases. In addition, it is observed that OES from the discharge is mainly in the ultraviolet domain. The results are helpful in the study of the mechanism and application of plasma in pollution-control in either air or water.

  4. GRACE-based estimates of water discharge over the Yellow River basin

    Institute of Scientific and Technical Information of China (English)

    Qiong Li; BO Zhong; Zhicai Luo; Chaolong Yao

    2016-01-01

    As critical component of hydrologic cycle,basin discharge is a key issue for understanding the hydrological and climatologic related to water and energy cycles.Combining GRACE gravity field models with ET from GLDAS models and precipitation from GPCP,discharge of the Yellow River basin are estimated from the water balance equation.While comparing the results with discharge from GLDAS model and in situ measurements,the results reveal that discharge from Mosaic and CLM GLDAS model can partially represent the river discharge and the discharge estimation from water balance equation could reflect the discharge from precipitation over the Yellow River basin.

  5. Waste water discharge and its effect on the quality of water of Mahim creek and bay

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Desai, B.N.

    Coastal environment around Mahim was monitored to evaluate the effects of domestic and industrial waste water discharge in Mahim Creek, Maharashtra, India. Vertical salinity and DO gradient occasionally observed in the Mahim Bay during postmonsoon...

  6. Surface-Water Conditions in Georgia, Water Year 2005

    Science.gov (United States)

    Painter, Jaime A.; Landers, Mark N.

    2007-01-01

    INTRODUCTION The U.S. Geological Survey (USGS) Georgia Water Science Center-in cooperation with Federal, State, and local agencies-collected surface-water streamflow, water-quality, and ecological data during the 2005 Water Year (October 1, 2004-September 30, 2005). These data were compiled into layers of an interactive ArcReaderTM published map document (pmf). ArcReaderTM is a product of Environmental Systems Research Institute, Inc (ESRI?). Datasets represented on the interactive map are * continuous daily mean streamflow * continuous daily mean water levels * continuous daily total precipitation * continuous daily water quality (water temperature, specific conductance dissolved oxygen, pH, and turbidity) * noncontinuous peak streamflow * miscellaneous streamflow measurements * lake or reservoir elevation * periodic surface-water quality * periodic ecological data * historical continuous daily mean streamflow discontinued prior to the 2005 water year The map interface provides the ability to identify a station in spatial reference to the political boundaries of the State of Georgia and other features-such as major streams, major roads, and other collection stations. Each station is hyperlinked to a station summary showing seasonal and annual stream characteristics for the current year and for the period of record. For continuous discharge stations, the station summary includes a one page graphical summary page containing five graphs, a station map, and a photograph of the station. The graphs provide a quick overview of the current and period-of-record hydrologic conditions of the station by providing a daily mean discharge graph for the water year, monthly statistics graph for the water year and period of record, an annual mean streamflow graph for the period of record, an annual minimum 7-day average streamflow graph for the period of record, and an annual peak streamflow graph for the period of record. Additionally, data can be accessed through the layer's link

  7. Discharge, water temperature, and water quality of Warm Mineral Springs, Sarasota County, Florida: A retrospective analysis

    Science.gov (United States)

    Metz, Patricia A.

    2016-09-27

    Warm Mineral Springs, located in southern Sarasota County, Florida, is a warm, highly mineralized, inland spring. Since 1946, a bathing spa has been in operation at the spring, attracting vacationers and health enthusiasts. During the winter months, the warm water attracts manatees to the adjoining spring run and provides vital habitat for these mammals. Well-preserved late Pleistocene to early Holocene-age human and animal bones, artifacts, and plant remains have been found in and around the spring, and indicate the surrounding sinkhole formed more than 12,000 years ago. The spring is a multiuse resource of hydrologic importance, ecological and archeological significance, and economic value to the community.The pool of Warm Mineral Springs has a circular shape that reflects its origin as a sinkhole. The pool measures about 240 feet in diameter at the surface and has a maximum depth of about 205 feet. The sinkhole developed in the sand, clay, and dolostone of the Arcadia Formation of the Miocene-age to Oligocene-age Hawthorn Group. Underlying the Hawthorn Group are Oligocene-age to Eocene-age limestones and dolostones, including the Suwannee Limestone, Ocala Limestone, and Avon Park Formation. Mineralized groundwater, under artesian pressure in the underlying aquifers, fills the remnant sink, and the overflow discharges into Warm Mineral Springs Creek, to Salt Creek, and subsequently into the Myakka River. Aquifers described in the vicinity of Warm Mineral Springs include the surficial aquifer system, the intermediate aquifer system within the Hawthorn Group, and the Upper Floridan aquifer in the Suwannee Limestone, Ocala Limestone, and Avon Park Formation. The Hawthorn Group acts as an upper confining unit of the Upper Floridan aquifer.Groundwater flow paths are inferred from the configuration of the potentiometric surface of the Upper Floridan aquifer for September 2010. Groundwater flow models indicate the downward flow of water into the Upper Floridan aquifer

  8. Characterization of a dielectric barrier discharge in contact with liquid and producing a plasma activated water

    Science.gov (United States)

    Neretti, G.; Taglioli, M.; Colonna, G.; Borghi, C. A.

    2017-01-01

    In this work a low-temperature plasma source for the generation of plasma activated water (PAW) is developed and characterized. The plasma reactor was operated by means of an atmospheric-pressure air dielectric barrier discharge (DBD). The plasma generated is in contact with the water surface and is able to chemically activate the liquid medium. Electrodes were supplied by both sinusoidal and nanosecond-pulsed voltage waveforms. Treatment times were varied from 2 to 12 min to increase the energy dose released to the water by the DBD plasma. The physics of the discharge was studied by means of electrical, spectroscopic and imaging diagnostics. The interaction between the plasma and the liquid was investigated as well. Temperature and composition of the treated water were detected. Images of the discharges showed a filamentary behaviour in the sinusoidal case and a more homogeneous behaviour in the nanosecond-pulsed one. The images and the electrical measurements allowed to evaluate an average electron number density of about 4  ×  1019 and 6  ×  1017 m-3 for the sinusoidal and nanosecond-pulsed discharges respectively. Electron temperatures in the range of 2.1÷2.6 eV were measured by using spectroscopic diagnostics. Rotational temperatures in the range of 318-475 K were estimated by fitting synthetic spectra with the measured ones. Water temperature and pH level did not change significantly after the exposure to the DBD plasma. The production of ozone and hydrogen peroxide within the water was enhanced by increasing the plasma treatment time and the energy dose. Numerical simulations of the nanosecond-pulsed discharge were performed by using a self-consistent coupling of state-to-state kinetics of the air mixture with the Boltzmann equation of free electron kinetics. Temporal evolution of the electron energy distribution function shows departure from the Maxwellian distribution especially during the afterglow phase of the discharge. When

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

    Science.gov (United States)

    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

  10. Experimental investigation of surface roughness in electrical discharge turning process

    Science.gov (United States)

    Gohil, Vikas; Puri, Y. M.

    2016-10-01

    In the present study the effects of machining parameters on the average surface roughness (Ra) in electrical discharge turning (EDT) is investigated. EDT is a new machining process in which a rotary spindle is added to a conventional die-sinking EDM machine in order to produce cylindrical components. In this method a new process parameter (spindle rotation) along with pulse on time and current is introduced to study its effect on Ra. This has been done by means of full factorial design (21 × 32) of experiments. A mathematical model has been developed for Ra by regression analysis and factor effects were analyzed using analysis of variance (ANOVA). Signal-to-noise ratio analysis is used to find the optimal condition.

  11. Diffuse coplanar surface barrier discharge -- basic properties and its application in surface treatment of nonwovens

    Science.gov (United States)

    Kovacik, Dusan; Rahel, Jozef; Kubincova, Jana; Zahoranova, Anna; Cernak, Mirko

    2009-10-01

    In recent years, low temperature atmospheric pressure plasma surface treatments have become a hot topic because of the potential of fast and efficient in-line processing fabrication without expensive vacuum equipment. A major problem of atmospheric pressure treatment in air is insufficient treatment uniformity because, particularly at the higher plasma power densities, the air plasma has the tendency of filamentation and transition into an arc discharge. Diffuse coplanar surface barrier discharge (DCSBD) plasma source has been developed to overcome these problems. This type of discharge enables to generate macroscopically homogeneous thin (˜ 0.3 mm) plasma layer with power density of some 100 W/cm^3 practically in any gas without admixture of He. It was found that the ambient air plasma of DCSBD is capable to make lightweight polypropylene nonwoven fabrics permanently hydrophilic, without any pinholing and with low power consumption of some 1 kWh/kg.

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

    Science.gov (United States)

    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...

  13. Sustaining dry surfaces under water

    DEFF Research Database (Denmark)

    Jones, Paul R.; Hao, Xiuqing; Cruz-Chu, Eduardo R.

    2015-01-01

    Rough surfaces immersed under water remain practically dry if the liquid-solid contact is on roughness peaks, while the roughness valleys are filled with gas. Mechanisms that prevent water from invading the valleys are well studied. However, to remain practically dry under water, additional...... mechanisms need consideration. This is because trapped gas (e.g. air) in the roughness valleys can dissolve into the water pool, leading to invasion. Additionally, water vapor can also occupy the roughness valleys of immersed surfaces. If water vapor condenses, that too leads to invasion. These effects have...... not been investigated, and are critically important to maintain surfaces dry under water.In this work, we identify the critical roughness scale, below which it is possible to sustain the vapor phase of water and/or trapped gases in roughness valleys – thus keeping the immersed surface dry. Theoretical...

  14. Sustaining dry surfaces under water

    Science.gov (United States)

    Jones, Paul R.; Hao, Xiuqing; Cruz-Chu, Eduardo R.; Rykaczewski, Konrad; Nandy, Krishanu; Schutzius, Thomas M.; Varanasi, Kripa K.; Megaridis, Constantine M.; Walther, Jens H.; Koumoutsakos, Petros; Espinosa, Horacio D.; Patankar, Neelesh A.

    2015-08-01

    Rough surfaces immersed under water remain practically dry if the liquid-solid contact is on roughness peaks, while the roughness valleys are filled with gas. Mechanisms that prevent water from invading the valleys are well studied. However, to remain practically dry under water, additional mechanisms need consideration. This is because trapped gas (e.g. air) in the roughness valleys can dissolve into the water pool, leading to invasion. Additionally, water vapor can also occupy the roughness valleys of immersed surfaces. If water vapor condenses, that too leads to invasion. These effects have not been investigated, and are critically important to maintain surfaces dry under water. In this work, we identify the critical roughness scale, below which it is possible to sustain the vapor phase of water and/or trapped gases in roughness valleys - thus keeping the immersed surface dry. Theoretical predictions are consistent with molecular dynamics simulations and experiments.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Artificial Ground Water Recharge with Surface Water

    Science.gov (United States)

    Heviánková, Silvie; Marschalko, Marian; Chromíková, Jitka; Kyncl, Miroslav; Korabík, Michal

    2016-10-01

    With regard to the adverse manifestations of the recent climatic conditions, Europe as well as the world have been facing the problem of dry periods that reduce the possibility of drawing drinking water from the underground sources. The paper aims to describe artificial ground water recharge (infiltration) that may be used to restock underground sources with surface water from natural streams. Among many conditions, it aims to specify the boundary and operational conditions of the individual aspects of the artificial ground water recharge technology. The principle of artificial infiltration lies in the design of a technical system, by means of which it is possible to conduct surplus water from one place (in this case a natural stream) into another place (an infiltration basin in this case). This way, the water begins to infiltrate into the underground resources of drinking water, while the mixed water composition corresponds to the water parameters required for drinking water.

  17. Application of bipolar gas discharge for water sterilization from S.aureus and E-coli

    Science.gov (United States)

    Taran, Anatoliy; Okhrimovskyy, Andriy; Komozynskyi, Petro; Kyslytsyn, Oleksandr; Taran, Svitlana; Filimonova, Nataliya; Lesnoy, Viktor; Oranska, Daria

    2016-09-01

    Recently, water treatment by gas discharge above the surface of the liquid has attracted a lot of attention. In most cases, however, the unipolar power source is used. Bipolar pulses of high voltage and current can increases degree of water sterilization from organic compounds, both chemical and bacterial since non equilibrium atmospheric plasma contains not only electrons but also positive and negative ions as well as an excited molecules or atoms and active radicals. Heavy charged particles of both signs, accelerated by bipolar electric field, can easily destroy chemical and biological contaminants in water. To evaluate this phenomenon, high voltage bipolar pulse generator was used. The amplitude of the pulse voltage was approaching value of 200 kV at the discharge ignition. The repetition time was varied from 1 to 14 milliseconds. Current pulse had a shape of a superposition of bipolar pulses with decaying amplitude. Liquid surface was used as a cathode or anode.Two types of contaminants, S.aureus and E.coli, with was 1 . 5 ×108 CFU/mL were treated by bipolar high voltage pulse discharge. After 30 minutes of exposition, no contaminants were observed within the water.

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

    Science.gov (United States)

    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.

  19. Drainage-water travel times as a key factor for surface water contamination

    OpenAIRE

    Groenendijk, P.; Eertwegh, van den, A.J.M.

    2004-01-01

    The importance of the unsaturated zone as an inextricable part of the hydrologic cycle has long been recognized. The root zone and the unsaturated sub-surface domain are chemically and biologically the most active zones. The interrelationships between soil, subsoil and surface waters make it unrealistic to treat the saturated and unsaturated zones and the discharge to surface waters separately. Point models describe vertical water flow in the saturated zone and possibly lateral flow by defini...

  20. Recycled Coarse Aggregate Produced by Pulsed Discharge in Water

    Science.gov (United States)

    Namihira, Takao; Shigeishi, Mitsuhiro; Nakashima, Kazuyuki; Murakami, Akira; Kuroki, Kaori; Kiyan, Tsuyoshi; Tomoda, Yuichi; Sakugawa, Takashi; Katsuki, Sunao; Akiyama, Hidenori; Ohtsu, Masayasu

    In Japan, the recycling ratio of concrete scraps has been kept over 98 % after the Law for the Recycling of Construction Materials was enforced in 2000. In the present, most of concrete scraps were recycled as the Lower Subbase Course Material. On the other hand, it is predicted to be difficult to keep this higher recycling ratio in the near future because concrete scraps increase rapidly and would reach to over 3 times of present situation in 2010. In addition, the demand of concrete scraps as the Lower Subbase Course Material has been decreased. Therefore, new way to reuse concrete scraps must be developed. Concrete scraps normally consist of 70 % of coarse aggregate, 19 % of water and 11 % of cement. To obtain the higher recycling ratio, the higher recycling ratio of coarse aggregate is desired. In this paper, a new method for recycling coarse aggregate from concrete scraps has been developed and demonstrated. The system includes a Marx generator and a point to hemisphere mesh electrode immersed in water. In the demonstration, the test piece of concrete scrap was located between the electrodes and was treated by the pulsed discharge. After discharge treatment of test piece, the recycling coarse aggregates were evaluated under JIS and TS and had enough quality for utilization as the coarse aggregate.

  1. Dechlorination Technology Manual. Final report. [Utility cooling water discharge systems

    Energy Technology Data Exchange (ETDEWEB)

    Aschoff, A.F.; Chiesa, R.J.; Jacobs, M.H.; Lee, Y.H.; Mehta, S.C.; Meko, A.C.; Musil, R.R.; Sopocy, D.M.; Wilson, J.A.

    1984-11-01

    On November 19, 1982, the United States Environmental Protection Agency (EPA) promulgated regulations severely restricting chlorination practices as they relate to utility cooling water discharge systems. EPRI authorized the preparation of a manual on dechlorination technology to assist utilities in evaluating the various alternatives available to them to meet these new requirements. The Dechlorination Technology Manual emphasizes the engineering aspects involved in the selection and design of dechlorination systems. However, background information is included concerning chemistry, regulatory requirements, environmental considerations and aquatic impacts. There is also a brief discussion of the various alternatives to dechlorination. Case studies are given to acquaint the user with the use of the manual for the design of chlorination facilities given various site-related characteristics, such as salt versus fresh waters. Numerous graphs and tables are presented to facilitate the selection and design process. 207 references, 66 figures, 60 tables.

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

    Science.gov (United States)

    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.

  3. Dynamics of near-surface electric discharges and mechanisms of their interaction with the airflow

    Science.gov (United States)

    Leonov, Sergey B.; Adamovich, Igor V.; Soloviev, Victor R.

    2016-12-01

    The main focus of the review is on dynamics and kinetics of near-surface discharge plasmas, such as surface dielectric barrier discharges sustained by AC and repetitively pulsed waveforms, pulsed DC discharges, and quasi-DC discharges, generated in quiescent air and in the airflow. A number of technical issues related to plasma flow control applications are discussed in detail, including discharge development via surface ionization waves, charge transport and accumulation on dielectric surface, discharge contraction, different types of flow perturbations generated by surface discharges, and effect of high-speed flow on discharge dynamics. In the first part of the manuscript, plasma morphology and results of electrical and optical emission spectroscopy measurements are discussed. Particular attention is paid to dynamics of surface charge accumulation and dissipation, both in diffuse discharges and during development of ionization instabilities resulting in discharge contraction. Contraction leads to significant increase of both the surface area of charge accumulation and the energy coupled to the plasma. The use of alternating polarity pulse waveforms accelerates contraction of surface dielectric barrier discharges and formation of filamentary plasmas. The second part discusses the interaction of discharge plasmas with quiescent air and the external airflow. Four major types of flow perturbations have been identified: (1) low-speed near-surface jets generated by electrohydrodynamic interaction (ion wind); (2) spanwise and streamwise vortices formed by both electrohydrodynamic and thermal effects; (3) weak shock waves produced by rapid heating in pulsed discharges on sub-microsecond time scale; and (4) near-surface localized stochastic perturbations, on sub-millisecond time, detected only recently. The mechanism of plasma-flow interaction remains not fully understood, especially in filamentary surface dielectric barrier discharges. Localized quasi-DC surface

  4. Reactivity of water vapor in an atmospheric pressure DBD -Application to LDPE surfaces

    CERN Document Server

    Collette, S; Viville, Pascal; Reniers, François

    2016-01-01

    The reactivity of water vapor introduced in an atmospheric dielectric barrier discharge supplied in argon is investigated through optical emission spectroscopy measurements. This discharge is also used for the treatment of LDPE surfaces. Water contact angles measurements, XPS and AFM techniques are used to study the grafting of oxygen functions on the LDPE surface and increase its hydrophilicity.

  5. The effect on river discharge estimation by considering an interaction between land surface process and river routing process

    Science.gov (United States)

    Yorozu, K.; Tachikawa, Y.

    2015-06-01

    There is much research assessing the impact of climate change on the hydrologic cycle. However, it has often focused on a specific hydrologic process, without considering the interaction among hydrologic processes. In this study, a distributed hydrologic model considering the interaction between flow routing and land surface processes was developed, and its effect on river discharge estimation was investigated. The model enables consideration of flow routing, irrigation withdrawal from rivers at paddy fields, crop growth depending on water and energy status, and evapotranspiration based on meteorological, soil water and vegetation status. To examine the effects of hydrologic process interaction on river discharge estimation, a developed model was applied to the Chao Phraya river basin using near surface meteorological data collected by the Japanese Meteorological Research Institute's Atmospheric General Circulation Model (MRI-AGCM3.2S) with TL959 spatial resolution as forcing data. Also, a flow routing model, which was part of the developed model, was applied independently, using surface and subsurface runoff data from the same GCM. In the results, the developed model tended to estimate a smaller river discharge than was estimated by the river routing model, because of the irrigation effect. In contrast, the annual maximum daily discharge calculated by the developed model was 24% greater than that by the flow routing model. It is assumed that surface runoff in the developed model was greater than that in the flow routing model because the soil water content was maintained at a high level through irrigation withdrawal. As for drought discharge, which is defined as the 355th largest daily discharge, the developed model gave a discharge 2.7-fold greater than the flow routing model. It seems that subsurface runoff in the developed model was greater than that in the flow routing model. The results of this study suggest that considering hydrologic interaction in a

  6. Study of Ag and Au Nanoparticles Synthesized by Arc Discharge in Deionized Water

    Directory of Open Access Journals (Sweden)

    Der-Chi Tien

    2010-01-01

    Full Text Available The paper presents a study of Ag and Au nanofluids synthesized by the arc discharge method (ADM in deionized water. The metallic Ag nanoparticle (Ag0 and ionic Ag (Ag+ have played an important role in the battle against germs which are becoming more drug-resistant every year. Our study indicates that Ag nanoparticle suspension (SNPS fabricated by using ADM without added surfactants exclusively contains the metallic Ag nanoparticle and ionic Ag. Besides that, the ADM in deionized water has also been employed for the fabrication process of Au nanoparticles. The experimental results indicate that the prepared Ag nanoparticles can react with the dissolved H2CO3 in deionized water, leading to the formation of Ag2CO3. Significantly different to Ag, the prepared Au nanoparticles with their surfaces bonded by oxygen are suspended in deionized water by the formation of hydrogen bonded with the neighboring water molecules.

  7. Transferred plasma jet from a dielectric barrier discharge for processing of poly(dimethylsiloxane) surfaces

    CERN Document Server

    Nascimento, Fellype do; Canesqui, Mara A; Moshkalev, Stanislav

    2016-01-01

    In this work we studied processing of poly(dimethylsiloxane) (PDMS) surfaces using dielectric barrier discharge (DBD) plasma in two different assemblies, one using the primary plasma jet obtained from a conventional DBD and the other using a DBD plasma jet transfer. The evolution of water contact angle (WCA) in function of plasma processing time and in function of aging time as well as the changes in the surface roughness of PDMS samples for both plasma treatments have been studied. We also compared vibrational and rotational temperatures for both plasmas and for the first time the vibrational temperature (T_vib) for the transferred plasma jet has been shown to be higher as compared with the primary jet. The increment in the T_vib value seems to be the main reason for the improvements in adhesion properties and surface wettability for the transferred plasma jet. Possible explanations for the increase in the vibrational temperature are presented.

  8. PTFE surface etching in the post-discharge of a RF scanning plasma torch: evidence of ejected fluorinated species

    CERN Document Server

    Dufour, Thierry; Viville, Pascal; Duluard, Corinne Y; Desbief, Simon; Lazzaroni, Roberto; Reniers, François

    2016-01-01

    The texturization of poly(tetrafluoroethylene) (PTFE) surfaces is achieved at atmospheric pressure by using the post-discharge of a radio-frequency plasma torch supplied in helium and oxygen gases. The surface properties are characterized by contact angle measurement, X-ray photoelectron spectroscopy and atomic force microscopy. We show that the plasma treatment increases the surface hydrophobicity (with water contact angles increasing from 115 to 155{\\deg}) only by modifying the PTFE surface morphology and not the stoichiometry. Measurements of sample mass losses correlated to the ejection of CF$_2$ fragments from the PTFE surface evidenced an etching mechanism at atmospheric pressure.

  9. Modelling mid-span water table depth and drainage discharge ...

    African Journals Online (AJOL)

    2015-04-03

    Apr 3, 2015 ... addition, the time requirements for this method make it unsuit- able for agricultural .... auger smeared the surface of the auger-hole during the drilling process. ... which water level readings were taken every 10 s, using a Laser.

  10. Total Phosphorus in Surface Water

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excess phosphorus in surface water can result in eutrophication. TOTALP is reported in kilograms/hectare/year. More information about these resources, including the...

  11. Total Nitrogen in Surface Water

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excess nitrogen in surface water can result in eutrophication. TOTALN is reported in kilograms/hectare/year. More information about these resources, including the...

  12. Free Surface Water Tunnel (FSWT)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Free Surface Water Tunnel consists of the intake plenum, the test section and the exit plenum. The intake plenum starts with a perforated pipe that...

  13. Nutrient Enrichment in Estuaries from Discharge of Shallow Ground Water, Mt. Desert Island, Maine

    Science.gov (United States)

    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

  14. New acoustic system for continuous measurement of river discharge and water temperature

    Directory of Open Access Journals (Sweden)

    Kiyosi KAWANISI

    2010-03-01

    Full Text Available In many cases, river discharge is indirectly estimated from water level or streamflow velocity near the water surface. However, these methods have limited applicability. In this study, an innovative system, the fluvial acoustic tomography system (FATS, was used for continuous discharge measurement. Transducers with a central frequency of 30 kHz were installed diagonally across the river. The system’s significant functions include accurate measurement of the travel time of the transmission signal using a GPS clock and the attainment of a high signal-to-noise ratio as a result of modulation of the signal by the 10th order M-sequence. In addition, FATS is small and lightweight, and its power consumption is low. Operating in unsteady streamflow, FATS successfully measured the cross-sectional average velocity. The agreement between FATS and acoustic Doppler current profilers (ADCPs on water discharge was satisfactory. Moreover, the temporal variation of the cross-sectional average temperature deduced from the sound speed of FATS was similar to that measured by a temperature sensor near the bank.

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

    Science.gov (United States)

    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 -.

  16. Surface oxide formation during corona discharge treatment of AA 1050 aluminium surfaces

    DEFF Research Database (Denmark)

    Minzari, Daniel; Møller, Per; Kingshott, Peter

    2008-01-01

    Atmospheric plasmas have traditionally been used as a non-chemical etching process for polymers, but the characteristics of these plasmas could very well be exploited for metals for purposes more than surface cleaning that is presently employed. This paper focuses on how the corona discharge...... process modifies aluminium AA 1050 surface, the oxide growth and resulting corrosion properties. The corona treatment is carried out in atmospheric air. Treated surfaces are characterized using XPS, SEM/EDS, and FIB-FESEM and results suggest that an oxide layer is grown, consisting of mixture of oxide...... and hydroxide. The thickness of the oxide layer extends to 150–300 nm after prolonged treatment. Potentiodynamic polarization experiments show that the corona treatment reduces anodic reactivity of the surface significantly and a moderate reduction of the cathodic reactivity....

  17. Inactivation of Escherichia coli on PTFE surfaces by diffuse coplanar surface barrier discharge

    Science.gov (United States)

    Tučeková, Zlata; Koval'ová, Zuzana; Zahoranová, Anna; Machala, Zdenko; Černák, Mirko

    2016-08-01

    The non-equilibrium plasma of diffuse coplanar surface barrier discharge (DCSBD) was tested for decontamination of bacteria Escherichia coli on polymer surfaces. We investigated the optical parameters of DCSBD plasma generated in synthetic air with different relative humidity. Our study was provided to estimate the main plasma components active during the DCSBD plasma degradation of E. coli contamination prepared on polytetrafluoroethylene (PTFE, Teflon) surface, in ambient air at atmospheric pressure. The DCSBD plasma was characterized by means of electrical measurements and optical emission spectroscopy. The inactivation of E. coli bacteria was evaluated by standard microbiological cultivation (CFU plate counting). The experimental results of the germicidal efficiency obtained for short plasma exposure times proved the effectiveness of DCSBD plasma for the polymer surface decontamination. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  18. Source Water Assessment for the Las Vegas Valley Surface Waters

    Science.gov (United States)

    Albuquerque, S. P.; Piechota, T. C.

    2003-12-01

    The 1996 amendment to the Safe Drinking Water Act of 1974 created the Source Water Assessment Program (SWAP) with an objective to evaluate potential sources of contamination to drinking water intakes. The development of a Source Water Assessment Plan for Las Vegas Valley surface water runoff into Lake Mead is important since it will guide future work on source water protection of the main source of water. The first step was the identification of the watershed boundary and source water protection area. Two protection zones were delineated. Zone A extends 500 ft around water bodies, and Zone B extends 3000 ft from the boundaries of Zone A. These Zones extend upstream to the limits of dry weather flows in the storm channels within the Las Vegas Valley. After the protection areas were identified, the potential sources of contamination in the protection area were inventoried. Field work was conducted to identify possible sources of contamination. A GIS coverage obtained from local data sources was used to identify the septic tank locations. Finally, the National Pollutant Discharge Elimination System (NPDES) Permits were obtained from the State of Nevada, and included in the inventory. After the inventory was completed, a level of risk was assigned to each potential contaminating activity (PCA). The contaminants of concern were grouped into five categories: volatile organic compounds (VOCs), synthetic organic compounds (SOCs), inorganic compounds (IOCs), microbiological, and radionuclides. The vulnerability of the water intake to each of the PCAs was assigned based on these five categories, and also on three other factors: the physical barrier effectiveness, the risk potential, and the time of travel. The vulnerability analysis shows that the PCAs with the highest vulnerability rating include septic systems, golf courses/parks, storm channels, gas stations, auto repair shops, construction, and the wastewater treatment plant discharges. Based on the current water quality

  19. Streamers sliding on a water surface

    Science.gov (United States)

    Akishev, Yuri Semenov; Karalnik, Vladimir; Medvedev, Mikhail; Petryakov, Alexander; Trushkin, Nikolay; Shafikov, Airat

    2017-06-01

    The features of an electrical interaction between surface streamers (thin current filaments) sliding on a liquid and liquid itself are still unknown in many details. This paper presents the experimental results on properties of the surface streamers sliding on water with different conductivity (distilled and tap water). The streamers were initiated with a sharpened thin metallic needle placed above the liquid and stressed with a periodical or pulsed high voltage. Two electrode systems were used and tested. The first of them provides in advance the existence of the longitudinal electric field above the water. The second one imitates the electrode geometry of a pin-to-plane dielectric barrier discharge in which the barrier is a thick layer of liquid. The electrical and optical characteristics of streamers were complemented with data on the spectroscopic measurements. It was revealed that surface streamers on water have no spatial memory. Contribution to the topical issue "The 15th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XV)", edited by Nicolas Gherardi and Tomáš Hoder

  20. Surface Modification of Fluororubber Using Atmospheric Pressure Dielectric Barrier Discharge (DBD)

    Institute of Scientific and Technical Information of China (English)

    TONG Wei; LU Canhui; CAI Yongkun; HUANG Yigang

    2007-01-01

    Fluoride rubber F2311 film, an alternating copolymer of CF2-CFC1 (CTFE) and CH2-CF2 (VF2) components, was treated by atmospheric pressure dielectric barrier discharge (DBD) in air. The surface structure, topography and surface chemistry of the treated F2311 films were characterized by contact angle measurement, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS), respectively. The experimental results showed that a short time air plasma treatment led to morphological, wettability and chemical changes in the F2311 films. The surface hydrophilicity increased greatly after the plasma treatment, the static water contact angle decreased from 98.6° to 32°, and oxygen containing groups (C=O, O-C=O, etc. ) were introduced. Atomic force microscopy revealed that plasma produced by DBD etched F2311 films obviously. The roughness of the samples increased remarkably with the formation of peaks and valleys on the treated surfaces. The increased surface wettability may be correlated with both the introduction of hydrophilic groups due to air plasma oxidation of the surface and the change in surface morphology etched by DBD.

  1. Characteristics of Ozone Production by Using Atmospheric Surface Glow Barrier Discharge

    Directory of Open Access Journals (Sweden)

    Mudtorlep NISOA

    2009-06-01

    Full Text Available Ozone is a strong oxidizer that can kill bacteria and other micro-organisms very effectively. In the recent years, ozone has become very important for sterilization of water used in shrimp farming and treatment of wastewater from food industry. However, ozonisers available in the markets are very expensive and have low energy-efficiency. In this work, a highly-efficient and low-cost system that can produce high-concentrations of ozone gas and dissolved ozone in water has been developed. The system consists of a dried air unit, high-voltage rf power supply, ozoniser tubes and venturi injector. The tubes are designed and configured to convert oxygen gas to ozone gas by atmospheric surface glow barrier discharge.

  2. Recirculation pump discharge line break tests at ROSA-III for a boiling water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, M.; Anoda, Y.; Kumamaru, H.; Nakamura, H.; Shiba, M.; Tasaka, K.

    1985-08-01

    Three loss-of-coolant accident (LOCA) tests were conducted at the Rig of Safety Assessment (ROSA)-III test facility, which simulates boiling water reactor (BWR)/6-251 with a volumetric scaling factor of 1/424. The fundamental features of the recirculation pump discharge line break LOCA and the effects of break areas on the features are investigated. It has been confirmed experimentally that the LOCA phenomena in the discharge line break are analogous to those in the suction line break with the same effective choking flow area, which is a sum of the least choking flow areas along the break flow paths and controls the system pressure responses. In general, the maximum effective choking flow area is (A /SUB j/ + A /SUB p/ ) for discharge line breaks and (A /SUB j/ + A /SUB o/ ) for suction line breaks, where A /SUB j/ , A /SUB p/ , and A /SUB o/ are the flow areas of the jet pump drive nozzles, the main recirculation pump discharge nozzle, and the break, respectively. The similarity between the ROSA-III test and a BWR LOCA has been confirmed in the key phenomena by the analyses using the RELAP5/MOD1 code. An atypical behavior is observed in the fuel rod surface temperature transient in the early phase of blowdown due to the limitation of the ROSA-III initial core power.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  4. Micro Hydropower generation by Discharge water of Dongbu Sewage Treatment Plant in Seogwipo City

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Il Seong

    2005-02-15

    This study aims to examine the possibility of Micro hydroelectric power plants by using discharged water from Dongbu Sewage Treatment Plant located in Seogwipo City, Jeju do. The results are as follows; The best location for installing the hydropower plant is at the location of EL(+)2.0, the joint owned surface of the water on the west between discharge flow meter chamber and the surface of the sea water. In calculating the quantity of electric power generation, the amount used is 0.157m{sup 3}/sec, the average 95day water Flow for the recent 3 years. The effective difference in elevation is 12.41m between discharge flow meter chamber and the location of hydraulic turbine installation. Therefore, the quantity of electric generation is expected to be 14.6kW. The monthly quantity of electric generation is 9.46 MW and the yearly quantity of electric generation is calculated to be 113.53 MW. The type of hydraulic turbine to be applied to the hydro power generation is the hydraulic turbine of low head miniflow. Therefore, it is recommended to choose an all-in-one inline-type hydraulic turbine generator. The recommended capacity is 50kW. The hydropower generation has The system of pollution-free energy production. Because the Jejudo government has promoted the free international city project, the image of Clean Jeju is expected to continuously rise. In addition, sewage disposal plants have been regarded as disgusting facilities. Considering this fact, the hydropower generation is expected to build up the image of friendly natural environment. In a word, this project should be considered to be The project of alternative energy production.

  5. The mechanistic basis for storage-dependent age distributions of water discharged from an experimental hillslope

    Science.gov (United States)

    Pangle, Luke A.; Kim, Minseok; Cardoso, Charlene; Lora, Marco; Meira Neto, Antonio A.; Volkmann, Till H. M.; Wang, Yadi; Troch, Peter A.; Harman, Ciaran J.

    2017-04-01

    Distributions of water transit times (TTDs), and related storage-selection (SAS) distributions, are spatially integrated metrics of hydrological transport within landscapes. Recent works confirm that the form of TTDs and SAS distributions should be considered time variant—possibly depending, in predictable ways, on the dynamic storage of water within the landscape. We report on a 28 day periodic-steady-state-tracer experiment performed on a model hillslope contained within a 1 m3 sloping lysimeter. Using experimental data, we calibrate physically based, spatially distributed flow and transport models, and use the calibrated models to generate time-variable SAS distributions, which are subsequently compared to those directly observed from the actual experiment. The objective is to use the spatially distributed estimates of storage and flux from the model to characterize how temporal variation in water storage influences temporal variation in flow path configurations, and resulting SAS distributions. The simulated SAS distributions mimicked well the shape of observed distributions, once the model domain reflected the spatial heterogeneity of the lysimeter soil. The spatially distributed flux vectors illustrate how the magnitude and directionality of water flux changes as the water table surface rises and falls, yielding greater contributions of younger water when the water table surface rises nearer to the soil surface. The illustrated mechanism is compliant with conclusions drawn from other recent studies and supports the notion of an inverse-storage effect, whereby the probability of younger water exiting the system increases with storage. This mechanism may be prevalent in hillslopes and headwater catchments where discharge dynamics are controlled by vertical fluctuations in the water table surface of an unconfined aquifer.

  6. Nonthermal Biological Treatments Using Discharge Plasma Produced by Pulsed Power 5. Inactivation of Cryptosporidium Oocysts by UV Emission Generated from Pulsed Arc Discharge in Water

    Science.gov (United States)

    Kunitomo, Shinta

    Cryptosporidium contaminates most surface waters around the world. It is difficult to remove through conventional treatment processes, and is extremely resistant to the method of chemical disinfection typically used to inactivate these microorganisms. We have developed a new technology for inactivating Cryptosporidium oocysts by using a pulsed arc discharge in water, which creates shock waves, UV emissions, and radicals. The pulsed arc is generated between two cylindrical stainless steel rod electrodes, 6 mm in diameter, and 2 mm apart. We applied this method to the inactivation of oocysts in backwash water from a sand-filter unit of a drinking water plant. The results indicate that the major factor influencing inactivation is UV emissions, and that more than 99% of the oocysts in the high turbidity backwash water (80 NTU) are inactivated with an energy of 0.24 kWh/m3.

  7. Effects of Hydroxyl Radicals on Introduced Organisms of Ship's Ballast Water Based Micro-Gap Discharge

    Institute of Scientific and Technical Information of China (English)

    BAI Mindong; ZHANG Zhitao; BAI Mindi; YANG Bo; BAI Xiyao

    2007-01-01

    With the physical method of micro-gap gas discharge,OH.radicals were produced by the ionization of O2 in air and H2O in the gaseous state,in order to explore more effective method totreat the ship's ballast water.The surface morphology of A1203 dielectric layer was analysed using Atomic Force Microscopy (AFM),where the size of A1203 particles was in the range of 2 μm to 5 μm.At the same time,the biochemical effect of hydroxyl radicals on the introduced organisms and the quality of ship's ballast water were studied.The results indicate that the main reasons of cell death are lipid peroxide and damage of the antioxidant enzyme system in Catalase (CAT),Peroxidase (POD) and Superoxide dismutase (SOD).In addition,the quality of the ballast water was greatly improved.

  8. Surface modification of acrylate intraocular lenses with dielectric barrier discharge plasma at atmospheric pressure

    Institute of Scientific and Technical Information of China (English)

    WANG Yao; LIU ZhenMei; XU ZhiKang; YAO Ke

    2009-01-01

    Surface modification with dielectric barrier discharge (DBD) plasma was carried out at atmospheric pressure (argon as the discharge gas) to improve the biocompatibility of hydrophobic acrylate intraocular lens (IOL). Changes of the plasma-treated IOL surface in chemical composition,morphology and hydrophilicity were comprehensively evaluated by X-ray photoelectron spectroscopy (XPS),field emission scanning electron microscopy (FESEM),atomic force microscopy (AFM) and water contact angle (WCA) measurements. The surface biocompatibility of the untreated and plasma-treated IOLs was compared with the adhesion behavior of platelets,macrophages and lens epithelial cells (LECs) in vitro. After DBD plasma treatment,the hydrophilicity of the IOL surface was obviously improved. The changes in WCA with treatment extension may be attributed to both the introduction of oxygen or/and nitrogen-containing polar groups and the increase of surface roughness induced by plasma etching effect. The existence of low molecular weight oxidized material (LMWOM) was proved on the plasma treated IOL which was caused by the chain scission effect of the plasma treatment. The plasma-treated lOLs resisted the adhesion of platelets and macrophages significantly. The LECs spreading and proliferation were postponed on the lOLs plasma-treated for more than 180 s,with a well maintained epithelial phenotype of LECs. The IOL biocompatibility was improved after the DBD plasma treatment. We speculate that slighter foreign-body reaction and later incidence of anterior capsule opacification (ACO) may be expected after implantation of the argon DBD plasma-treated IOL.

  9. Surface modification of acrylate intraocular lenses with dielectric barrier discharge plasma at atmospheric pressure

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Surface modification with dielectric barrier discharge(DBD) plasma was carried out at atmospheric pressure(argon as the discharge gas) to improve the biocompatibility of hydrophobic acrylate intraocular lens(IOL).Changes of the plasma-treated IOL surface in chemical composition,morphology and hydrophilicity were comprehensively evaluated by X-ray photoelectron spectroscopy(XPS),field emission scanning electron microscopy(FESEM),atomic force microscopy(AFM) and water contact angle(WCA) measurements.The surface biocompatibility of the untreated and plasma-treated IOLs was compared with the adhesion behavior of platelets,macrophages and lens epithelial cells(LECs) in vitro.After DBD plasma treatment,the hydrophilicity of the IOL surface was obviously improved.The changes in WCA with treatment extension may be attributed to both the introduction of oxygen or/and nitrogen-containing polar groups and the increase of surface roughness induced by plasma etching effect.The existence of low molecular weight oxidized material(LMWOM) was proved on the plasma-treated IOL which was caused by the chain scission effect of the plasma treatment.The plasma-treated IOLs resisted the adhesion of platelets and macrophages significantly.The LECs spreading and proliferation were postponed on the IOLs plasma-treated for more than 180 s,with a well maintained epithelial phenotype of LECs.The IOL biocompatibility was improved after the DBD plasma treatment.We speculate that slighter foreign-body reaction and later incidence of anterior capsule opacification(ACO) may be expected after implantation of the argon DBD plasma-treated IOL.

  10. Water discharge changes of the Changjiang River downstream Datong during dry season

    Institute of Scientific and Technical Information of China (English)

    CHENXiqing; WANGXiaoli; ZHANGErfeng

    2003-01-01

    Based on hydrometric data and extensive investigations on water-extracting projects, this paper presents a preliminary study on water discharge changes between Datong and Xuliujing during dry season. The natural hydrological processes and human factors that influence the water discharge are analyzed with the help of GIS method. The investigations indicate that the water-extracting projects downstream from Datong to Xuliujing had amounted to 64 in number by the end of 2000,with a water-extracting capacity up to 4,626 m3/s averaged in a tidal cycle. The water extraction from the Changjiang River has become the most important factor influencing the water discharge downstream Datong during dry season. The potential magnitude in water discharge changes are estimated based on historical records of water extraction and a water balance model. The computational results were calibrated with the actual data. The future trend in changes of water discharge into the sea during dry season was discussed by taking into consideration of newly built hydro-engineering projects. The water extraction downstream Datong in dry season before 2000 had a great influence on discharges into the sea in the extremely dry year like 1978-1979. It produced a net decrease of more than 490 m3/s in monthly mean discharges from the Changjiang into the sea. It is expected that the water extraction will continually increase in the coming decades, especially in dry years, when the net decrease in monthly mean water discharge will increase to more than 1000 m3/s and will give a far-reaching effect on the changes of water discharge from the Changjiang into the sea.

  11. Surface modification of polyester film by glow discharge tunnel at atmospheric pressure

    Institute of Scientific and Technical Information of China (English)

    XU Xiang-yu; WANG Shou-guo; YE Tian-chun; JING Guang-yin; YU Da-peng

    2004-01-01

    A large-area improved dielectric barrier glow discharge tunnel has been developed for modifying the surface of polyester film at atmospheric pressure with argon and oxygen gas mixtures. The electrical properties of the glow discharge tunnel were studied by simultaneous measurement of the voltage and current. In addition, the effect of the glow discharge tunnel treatment on the surface of polyester film were studied. The resultant modifications of the surface properties of the treated samples were investigated through scanning probe microscopy and contact angle measurement.

  12. Meteorological, stream-discharge, and water-quality data for 1986 through 1991 from two small basins in central Nevada

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Surface-Water and Ground-Water Interactions in the Central Everglades, Florida

    Science.gov (United States)

    Harvey, Judson W.; Newlin, Jessica T.; Krest, James M.; Choi, Jungyill; Nemeth, Eric A.; Krupa, Steven L.

    2004-01-01

    Recharge and discharge are hydrological processes that cause Everglades surface water to be exchanged for subsurface water in the peat soil and the underlying sand and limestone aquifer. These interactions are thought to be important to water budgets, water quality, and ecology in the Everglades. Nonetheless, relatively few studies of surface water and ground water interactions have been conducted in the Everglades, especially in its vast interior areas. This report is a product of a cooperative investigation conducted by the USGS and the South Florida Water Management District (SFWMD) aimed at developing and testing techniques that would provide reliable estimates of recharge and discharge in interior areas of WCA-2A (Water Conservation Area 2A) and several other sites in the central Everglades. The new techniques quantified flow from surface water to the subsurface (recharge) and the opposite (discharge) using (1) Darcy-flux calculations based on measured vertical gradients in hydraulic head and hydraulic conductivity of peat; (2) modeling transport through peat and decay of the naturally occurring isotopes 224Ra and 223Ra (with half-lives of 4 and 11 days, respectively); and (3) modeling transport and decay of naturally occurring and 'bomb-pulse' tritium (half-life of 12.4 years) in ground water. Advantages and disadvantages of each method for quantifying recharge and discharge were compared. In addition, spatial and temporal variability of recharge and discharge were evaluated and controlling factors identified. A final goal was to develop appropriately simplified (that is, time averaged) expressions of the results that will be useful in addressing a broad range of hydrological and ecological problems in the Everglades. Results were compared with existing information about water budgets from the South Florida Water Management Model (SFWMM), a principal tool used by the South Florida Water Management District to plan many of the hydrological aspects of the

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

    Science.gov (United States)

    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.

  15. Longevity of acid discharges from underground mines located above the regional water table.

    Science.gov (United States)

    Demchak, J; Skousen, J; McDonald, L M

    2004-01-01

    The duration of acid mine drainage flowing out of underground mines is important in the design of watershed restoration and abandoned mine land reclamation projects. Past studies have reported that acid water flows from underground mines for hundreds of years with little change, while others state that poor drainage quality may last only 20 to 40 years. More than 150 above-drainage (those not flooded after abandonment) underground mine discharges from Pittsburgh and Upper Freeport coal seams were located and sampled during 1968 in northern West Virginia, and we revisited 44 of those sites in 1999-2000 and measured water flow, pH, acidity, Fe, sulfate, and conductivity. We found no significant difference in flows between 1968 and 1999-2000. Therefore, we felt the water quality data could be compared and the data represented real changes in pollutant concentrations. There were significant water quality differences between year and coal seam, but no effect of disturbance. While pH was not significantly improved, average total acidity declined 79% between 1968 and 1999-2000 in Pittsburgh mines (from 66.8 to 14 mmol H+ L(-1)) and 56% in Upper Freeport mines (from 23.8 to 10.4 mmol H+ L(-1)). Iron decreased an average of about 80% across all sites (from an average of 400 to 72 mg L(-1)), while sulfate decreased between 50 and 75%. Pittsburgh seam discharge water was much worse in 1968 than Upper Freeport seam water. Twenty of our 44 sites had water quality information in 1980, which served as a midpoint to assess the slope of the decline in acidity and metal concentrations. Five of 20 sites (25%) showed an apparent exponential rate of decline in acidity and iron, while 10 of 20 sites (50%) showed a more linear decline. Drainage from five Upper Freeport sites increased in acidity and iron. While it is clear that surface mines and below-drainage underground mines improve in discharge quality relatively rapidly (20-40 years), above-drainage underground mines are not as

  16. Effects of the Liquid Conductivity on Pulsed High-voltage Discharge Modes in Water

    Institute of Scientific and Technical Information of China (English)

    Bin YANG; Le Cheng LEI; Ming Hua ZHOU

    2004-01-01

    Spark, stream and corona pulsed high-voltage discharges in water induced by the various initial conductivities have been examined in this paper. The discharge modes changed from spark to corona discharge with the liquid conductivity increasing. The apparent production of OH radical and quantum yield generated by spark discharge in distilled water were 11.57 μmol/L and 0.0978photon/s, respectively. A preliminary study on acid fuchsine (AF) treatment indicated that higher AF removal efficiency has been achieved by spark discharge. The process of degradation showed that the oxidative effects through OH radical oxidation did not play an important role and did increase with the discharge mode changing to spark discharge.

  17. Discharge Fee Policy Analysis: A Computable General Equilibrium (CGE Model of Water Resources and Water Environments

    Directory of Open Access Journals (Sweden)

    Guohua Fang

    2016-09-01

    Full Text Available To alleviate increasingly serious water pollution and shortages in developing countries, various kinds of policies have been implemented by local governments. It is vital to quantify and evaluate the performance and potential economic impacts of these policies. This study develops a Computable General Equilibrium (CGE model to simulate the regional economic and environmental effects of discharge fees. Firstly, water resources and water environment factors are separated from the input and output sources of the National Economic Production Department. Secondly, an extended Social Accounting Matrix (SAM of Jiangsu province is developed to simulate various scenarios. By changing values of the discharge fees (increased by 50%, 100% and 150%, three scenarios are simulated to examine their influence on the overall economy and each industry. The simulation results show that an increased fee will have a negative impact on Gross Domestic Product (GDP. However, waste water may be effectively controlled. Also, this study demonstrates that along with the economic costs, the increase of the discharge fee will lead to the upgrading of industrial structures from a situation of heavy pollution to one of light pollution which is beneficial to the sustainable development of the economy and the protection of the environment.

  18. Evaluation of the depth-integration method of measuring water discharge in large rivers

    Science.gov (United States)

    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

  19. Optical characteristics of the filamentary and diffuse modes in surface dielectric barrier discharge

    Science.gov (United States)

    Zhang, Ying; Li, Jie; Jiang, Nan; Shang, Ke-Feng; Lu, Na; Wu, Yan

    2016-11-01

    Surface dielectric barrier discharge (DBD) plasmas generally exhibits filamentary and diffuse discharges at atmospheric air. The focus of this investigation is on the different optical characteristics and quantitative research about morphological features of two discharge modes. The temporally and spatially resolved characteristics of discharge phenomenon together with the gas temperature are presented with microsecond time scale. Discharge area is estimated by the sum of pixels that equal to "1" in MATLAB software. The formation of diffuse plasma mainly depends on an increase of the ionization coefficient and a creation of sufficient seed electrons by the Penning effect at low electric fields. Accordingly, experimental measurements show that diffuse discharge during the negative half cycle has good uniformity and stability compared with filamentary discharge during the positive half cycle. The rotational temperatures of plasma are determined by comparing the experimental spectra with the simulated spectra that have been investigated. The plasma gas temperature keeps almost constant in the filamentary discharge phase and subsequently increased by about 115 K during the diffuse discharge. In addition, it is shown to be nearly identical in the axial direction. Non-uniform temperature distribution can be observed in the radial direction with large fluctuations. The plasma length is demonstrated almost the same between two discharge modes.

  20. Stabilization of the spark-discharge point on a sample surface by laser irradiation for steel analysis.

    Science.gov (United States)

    Matsuta, Hideyuki; Kitagawa, Kuniyuki; Wagatsuma, Kazuaki

    2006-10-01

    A combined technique with laser irradiation is suggested to control spark discharge for analytical use, having a unique feature that firing points of the spark discharge can be fixed by laser irradiation. Because the spark discharge easily initiates at particular surface sites, such as non-metallic inclusions, called selective discharge, the concentration of some elements sometimes deviates from their average one in spark discharge optical emission spectrometry. Therefore, stabilization of firing points on a sample surface could improve the analytical precision.

  1. Mobile surface water filtration system

    Directory of Open Access Journals (Sweden)

    Aashish Vatsyayan

    2012-09-01

    Full Text Available To design a mobile system for surface water filtrationMethodology: the filtration of surface impurities begins with their retraction to concentrated thickness using non ionising surfactants, then isolation using surface tension property and sedimentation of impurities in process chamber using electrocoagulation. Result:following studies done to determine the rate of spreading of crude oil on water a method for retraction of spread crude oil to concentrated volumes is developed involving addition of non -ionising surfactants in contrast to use of dispersants. Electrocoagulation process involves multiple processes taking place to lead to depositionof impurities such as oil, grease, metals. Studies of experiments conducted reveals parameters necessary for design of electrocoagulation process chamber though a holistic approach towards system designing is still required. Propeller theory is used in determining the required design of propeller and the desired thrust, the overall structure will finally contribute in deciding the choice of propeller.

  2. Surface Modification of Polyimide Film by Dielectric Barrier Discharge at Atmospheric Pressure

    Science.gov (United States)

    Peng, Shi; Li, Lingjun; Li, Wei; Wang, Chaoliang; Guo, Ying; Shi, Jianjun; Zhang, Jing

    2016-04-01

    In this paper, polyimide (PI) films are modified using an atmospheric pressure plasma generated by a dielectric barrier discharge (DBD) in argon. Surface performance of PI film and its dependence on exposure time from 0 s to 300 s are investigated by dynamic water contact angle (WCA), field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy in attenuated total multiple reflection mode (FTIR-ATR). The study demonstrates that dynamic WCA exhibits a minimum with 40 s plasma treatment, and evenly distributed nano-dots and shadow concaves appeared for 40 s and 12 s Ar plasma treatment individually. A short period of plasma modification can contribute to the scission of the imide ring and the introduction of C-O and C=O (-COOH) by detailed analysis of FTIR-ATR.

  3. Surface Modification Process by Electrical Discharge Machining with Ti Powder Green Compact Electrode

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper describes a new method of surface modification by Electrical Discharge Machining (EDM). By using ordinary EDM machine tool and kerosene fluid, a hard ceramic layer can be created on the workpiece surface with Ti or other compressed powder electrode in a certain condition. This new revolutionary method is called Electrical Discharge Coating (EDC). The process of EDC begins with electrode wear during EDM,then a kind of hard carbide is created through the thermal and chemical reaction between the wo...

  4. Surface water data at Los Alamos National Laboratory: 1995 water year. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Barks, R. [ed.; Shaull, D.A.; Alexander, M.R.; Reynolds, R.P.

    1996-08-01

    The principle investigators collected and computed surface water discharge data from 15 stream-gaging stations that cover most of Los Alamos National Laboratory. The United States Department of Interior Geological Survey, Water Resources Division, operates two of the stations under a subcontract; these are identified in the station manuscripts. Included in this report are data from one seepage run conducted in Los Alamos Canyon during the 1995 water year.

  5. Effect of water vapor on plasma morphology, OH and H2O2 production in He and Ar atmospheric pressure dielectric barrier discharges

    Science.gov (United States)

    Du, Yanjun; Nayak, Gaurav; Oinuma, Gaku; Peng, Zhimin; Bruggeman, Peter J.

    2017-04-01

    Although atmospheric pressure dielectric barrier discharges (DBDs) have a long history, the effects of water vapor on the discharge morphology and kinetics have not been studied intensively. We report a simultaneous investigation of discharge morphology, OH and H2O2 production in Ar and He DBDs operated at different water vapor concentrations and powers. The combined study allows us to assess the impact of the discharge morphology and power on the concentration dependence of the OH and H2O2 production. The morphology of the discharge is investigated by ICCD images and current–voltage waveforms. These diagnostics are complemented by broadband absorption and a colorimetric method to measure the gas temperature and the OH and H2O2 concentrations. The number of filaments in Ar DBD increases with increasing water concentration and power. The surface discharge part of the micro-discharge also reduces with increasing water concentration most likely due to a change in surface conductivity of the dielectric with changing water concentration. The OH density in the case of Ar is approximately double the OH density in He for similar power and water admixture. In contrast to the root square dependence of the OH density on the water concentration in He similar to diffuse RF discharges, the OH density in Ar increases for small water concentrations followed by a saturation and reduces for higher water concentrations. This dependence of OH density on water concentration is found to correlate with changes in discharge morphology. An analytical balance of the production and destruction mechanism of H2O2 is shown to be able to reproduce the ratio of the measured OH and H2O2 density for realistic values of electron densities.

  6. Partial discharge patterns related to surface deterioration in voids in epoxy

    DEFF Research Database (Denmark)

    Holbøll, Joachim; Henriksen, Mogens

    1990-01-01

    Results are presented from an investigation of the relationship between changes in partial discharge patterns and the surface deterioration process taking place in small naturally formed spherical voids in epoxy plastic. The voids were exposed to a moderate electric stress above inception level......, where partial discharges were present for more than 1500 h. Two types of electrical tree growth were found, the bush like tree and a single channel-like tree, which led to very different partial discharge patterns. It is concluded that the formation of crystals on a void surface leads to an immediate...

  7. Water discharge estimates from large radar altimetry datasets in the Amazon basin

    Directory of Open Access Journals (Sweden)

    A. C. V. Getirana

    2012-06-01

    Full Text Available In this study, we evaluate the use of a large radar altimetry dataset as a complementary gauging network capable of providing water discharge in ungauged regions within the Amazon basin. A rating-curve-based methodology is adopted to derive water discharge from altimetric data provided by Envisat at 444 virtual stations (VS. The stage-discharge relations at VS are built based on radar altimetry and outputs from a global flow routing scheme. In order to quantify the impact of modeling uncertainties on rating-curve based discharges, another experiment is performed using simulated discharges derived from a simplified data assimilation procedure. Discharge estimates at 90 VS are evaluated against observations during the curve fitting calibration (2002–2005 and evaluation (2006–2008 periods, resulting in mean relative RMS errors as high as 52% and 12% for experiments without and with assimilation, respectively. Without data assimilation, uncertainty of discharge estimates can be mostly attributed to forcing errors at smaller scales, generating a positive correlation between performance and drainage area. Mean relative errors (RE of altimetry-based discharges varied from 15% to 92% for large and small drainage areas, respectively. Rating curves produced a mean RE of 54% versus 68% from model outputs. Assimilating discharge data decreases the mean RE from 68% to 12%. These results demonstrate the feasibility of applying the proposed methodology to the regional or global scales. Also, it is shown the potential of satellite altimetry for predicting water discharge in poorly-gauged and ungauged river basins.

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

    Science.gov (United States)

    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

  9. Stormwater Priority Pollutants Versus Surface Water Quality Criteria

    DEFF Research Database (Denmark)

    Eriksson, Eva; Ledin, Anna; Baun, Anders

    2011-01-01

    Stormwater in urban areas comprises of a substantial part of the urban water cycle, dominating the flow in many small urban streams, and the pollution levels are sizeable. No stormwater quality criteria were found here and no European or national emission limit values exist. Stormwater pollutants...... however are present in levels exceeding most of the regulated surface water quality criteria and environmental quality standards. Therefore catchment characterisation is needed to chose suitable treatment prior to discharge into receiving surface waters, as the mixing may be insufficient in small streams....

  10. Experimental study of electric discharge treatment of nanodiamond particles in water

    Science.gov (United States)

    Medvedev, Dmitry; Sapunov, Dmitry; Potapkin, Boris; Korobtsev, Sergey

    2012-08-01

    A novel type of high voltage pulsed electric discharge in water flow in a Venturi tube is proposed. The influence of the novel discharge on sizes and properties of nanodiamond particles has been studied. Experiments were carried out in water media with purified detonation nanodiamonds made impure by non-diamond carbon material. The ability of high voltage pulsed electric discharge in water to modify nanoparticle conglomerates in water solution and to relieve spherically shaped nanodiamond conglomerates from the initial mixture with non-diamond material can be seen. Prolonged treatment of the suspension made it possible to relieve primary nanodiamond crystals from conglomerates. Formation of ordered and unordered structures from primary (3-5 nm) nanodiamond crystals has been observed. Study of the electric discharge in water was carried out at the pressure region from atmospheric down to 0.02 atm to reproduce conditions which are typical for the discharge in the Venturi tube in liquid flow and different gap lengths. Two `types' of discharge behavior depending on the geometry of the discharge system and other external parameters have been observed. Characteristics that are critical for understanding the behavior of the discharge in the Venturi tube in water flow have been investigated.

  11. A Study of DC Surface Plasma Discharge in Absence of Free Airflow: Ionic Wind Velocity Profile

    Directory of Open Access Journals (Sweden)

    M. Rafika

    2009-01-01

    Full Text Available In our study we are interested with the DC (Direct Current electric corona discharge created between two wire electrodes. We present experimental results related to some electroaerodynamic actuators based on the DC corona discharge at the surface of a dielectric material. We used different geometrical forms of dielectric surface such as a plate, a cylinder and a wing of aircraft of type NACA 0015. We present the current density-electric filed characteristics for different cases in order to determine the discharge regimes. The corona discharge produces non-thermal plasma so that it is called plasma discharge. Plasma discharge creates a tangential ionic wind above the surface at the vicinity of the wall. We have measured the ionic wind induced by the corona discharge in absence of free external airflow, we give the ionic wind velocity profiles for different surface forms and we compare the actuators effect based on the span of the ionic wind velocity values. We notice that the maximum ionic wind velocity is obtained with the NACA profile, which shows the effectiveness of this actuator for the airflow control.

  12. Effects of coal-bed methane discharge waters on the vegetation and soil ecosystem in Powder River Basin, Wyoming

    Science.gov (United States)

    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.

  13. Potential of pulsed corona discharges generated in water for the degradation of persistent pharmaceutical residues.

    Science.gov (United States)

    Banaschik, Robert; Lukes, Petr; Jablonowski, Helena; Hammer, Malte U; Weltmann, Klaus-Dieter; Kolb, Juergen F

    2015-11-01

    Anthropogenic pollutants and in particular pharmaceutical residues are a potential risk for potable water where they are found in increasing concentrations. Different environmental effects could already be linked to the presence of pharmaceuticals in surface waters even for low concentrations. Many pharmaceuticals withstand conventional water treatment technologies. Consequently, there is a need for new water purification techniques. Advanced oxidation processes (AOP), and especially plasmas with their ability to create reactive species directly in water, may offer a promising solution. We developed a plasma reactor with a coaxial geometry to generate large volume corona discharges directly in water and investigated the degradation of seven recalcitrant pharmaceuticals (carbamazepine, diatrizoate, diazepam, diclofenac, ibuprofen, 17α-ethinylestradiol, trimethoprim). For most substances we observed decomposition rates from 45% to 99% for treatment times of 15-66 min. Especially ethinylestradiol and diclofenac were readily decomposed. As an inherent advantage of the method, we found no acidification and only an insignificant increase in nitrate/nitrite concentrations below legal limits for the treatment. Studies on the basic plasma chemical processes for the model system of phenol showed that the degradation is primarily caused by hydroxyl radicals.

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

    Science.gov (United States)

    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)

  15. Measurement of the impulse produced by a pulsed surface discharge actuator in air

    Science.gov (United States)

    Elias, P. Q.; Castera, P.

    2013-09-01

    The pulsed surface discharge in atmospheric pressure air generates a shock wave, thereby transferring an impulse to the surrounding gas. The aim of this work is to measure this impulse, using implementation of a plasma actuator based on linear surface discharges of length up to 10 cm, and of linear energy in a range 0.1-0.5 J cm-1. The shock wave generated by the discharge is visualized using a pulsed schlieren system and the impulse is measured with a dedicated balance. These measurements are correlated with 1D numerical simulations of pulsed energy depositions in a perfect gas. Experiments show that the discharge generates a cylindrical shock wave that travels at sonic speed after a few tens of microseconds, and produces an impulse that varies from 1 to 4 mN s m-1 and scales linearly with the linear energy density. This linearity agrees with the numerical simulations when 9.5% of the energy dissipated in the discharge is assumed to heat the gas. Overall, to produce a time-averaged force similar to the one achieved by dielectric barrier discharge (DBD) actuators, 2 to 3 times more power is required. However, surface discharge actuators do not saturate, and thus can induce time-averaged forces one or two orders of magnitude above DBD when pulsed at several hundreds of hertz.

  16. Numerical investigation of the spatiotemporal distribution of chemical species in an atmospheric surface barrier-discharge

    Science.gov (United States)

    Hasan, M. I.; Walsh, J. L.

    2016-05-01

    Using a one dimensional time dependent convection-reaction-diffusion model, the temporal and spatial distributions of species propagating downstream of an atmospheric pressure air surface barrier discharge was studied. It was found that the distribution of negatively charged species is more spatially spread compared to positive ions species, which is attributed to the diffusion of electrons that cool down and attach to background gas molecules, creating different negative ions downstream of the discharge region. Given the widespread use of such discharges in applications involving the remote microbial decontamination of surfaces and liquids, the transport of plasma generated reactive species away from the discharge region was studied by implementing mechanical convection through the discharge region. It was shown that increased convection causes the spatial distribution of species density to become uniform. It was also found that many species have a lower density close to the surface of the discharge as convection prevents their accumulation. While for some species, such as NO2, convection causes a general increase in the density due to a reduced residence time close to the discharge region, where it is rapidly lost through reactions with OH. The impact of the applied power was also investigated, and it was found that the densities of most species, whether charged or neutral, are directly proportional to the applied power.

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

    Science.gov (United States)

    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.

  18. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    Directory of Open Access Journals (Sweden)

    Thangam Chinnadurai

    2016-12-01

    Full Text Available This study focuses on investigating the effects of process parameters, namely, Peak current (Ip, Pulse on time (Ton, Pulse off time (Toff, Water pressure (Wp, Wire feed rate (Wf, Wire tension (Wt, Servo voltage (Sv and Servo feed setting (Sfs, on the Material Removal Rate (MRR and Surface Roughness (SR for Wire electrical discharge machining (Wire-EDM of nickel using Taguchi method. Response Surface Methodology (RSM is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used.

  19. Surface water - groundwater interactions at different spatial and temporal scales

    DEFF Research Database (Denmark)

    Sebök, Éva

    in lowland catchments, mainly exploring and assessing Distributed Temperature Sensing (DTS) which by detecting variability in temperatures at the Sediment-Water Interface (SWI) can indirectly map variability in groundwater discharge at several spatial and temporal scales. On the small-scale (...As there is a growing demand for the protection and optimal management of both the surface water and groundwater resources, the understanding of their exchange processes is of great importance. This PhD study aimed at describing the natural spatial and temporal variability of these interactions...... detected large spatial variability in SWI temperatures with scattered high-discharge sites in a stream and also in a lake where discharge fluxes were estimated by vertical temperature profiles and seepage meter measurements. On the kilometre scale DTS indicated less spatial variability in streambed...

  20. Sporicidal properties from surface micro-discharge plasma under different plasma conditions at different humidities

    Science.gov (United States)

    Jeon, J.; Klaempfl, T. G.; Zimmermann, J. L.; Morfill, G. E.; Shimizu, T.

    2014-10-01

    In the current study, bacterial endospores of Geobacillus stearothermophilus are exposed to the surface micro-discharge plasma for 5 min and the humidity and power consumption are varied. At the low humidity of 5.5 ± 0.5 g m-3, almost no sporicidal effect (<0.5 log) is observed. At the high humidity of 17.9 ± 0.6 g m-3, the spore reduction increases monotonically up to 3.5 log with increasing power consumption. At a humidity of 10.4 ± 0.6 g m-3, the spores are inactivated in a limited range of power consumption with a maximum reduction of ˜2.5 log. The survival curves show a single-slope decrease of the spores. The contribution of heat and UV to the sporicidal effect as well as the inactivation of spores by the short-lived species from the plasma are ruled out. The concentration of ozone, one indicator for the long-lived species, is measured and no correlation with the sporicidal effect is found. In conclusion, water-related reactive species, e.g. hydrogen peroxide, appear to be responsible for the sporicidal effect under the investigated conditions. Furthermore, condensation of water at high humidity enables the plasma-activated water containing both long-lived and short-lived reactive species to contribute to the sporicidal effect.

  1. Using Contaminant Transport Modeling to Determine Historical Discharges at the Surface

    Science.gov (United States)

    Fogwell, T. W.

    2013-12-01

    When it is determined that a contaminated site needs to be remediated, the issue of who is going to pay for that remediation is an immediate concern. This means that there needs to be a determination of who the responsible parties are for the existing contamination. Seldom is it the case that records have been made and kept of the surface contaminant discharges. In many cases it is possible to determine the relative amount of contaminant discharge at the surface of the various responsible parties by employing a careful analysis of the history of contaminant transport through the surface, through the vadose zone, and within the saturated zone. The process begins with the development of a dynamic conceptual site model that takes into account the important features of the transport of the contaminants through the vadose zone and in the groundwater. The parameters for this model can be derived from flow data available for the site. The resulting contaminant transport model is a composite of the vadose zone transport model, together with the saturated zone (groundwater) flow model. Any calibration of the model should be carefully employed in order to avoid using information about the conclusions of the relative discharge amounts of the responsible parties in determining the calibrated parameters. Determination of the leading edge of the plume is an important first step. It is associated with the first discharges from the surface of the site. If there were several discharging parties at the same time, then it is important to establish a chemical or isotopic signature of the chemicals that were discharged. The time duration of the first discharger needs to be determined as accurately as possible in order to establish the appropriate characterization of the leading portion of the resulting plume in the groundwater. The information about the first discharger and the resulting part of the plume associated with this discharger serves as a basis for the determination of the

  2. Phosphonate removal from discharged circulating cooling water using iron-carbon micro-electrolysis.

    Science.gov (United States)

    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⁺).

  3. The Mechanical Analysis and Experimental Study of Shock Wave Effect of Electrical Discharge under Water In Filth Cleaning

    Institute of Scientific and Technical Information of China (English)

    Deng Qilin; Zhang Lei; Zhou Jinjin

    2004-01-01

    Filth adhering to metal pipes can be cleaned by shock wave generated by electrical discharge under water. The mechanism of shock wave effect of electrical discharge under water on filth cleaning is analyzed by building a mechanical model. A metal pipe coated with cement to simulate real filth is cleaned by using electrical discharge under water. The experimental results confirm the mechanical analysis and also show the technology of electrical discharge under water is an very effective method for filth cleaning.

  4. Water quality of large discharges from mines in the anthracite region of eastern Pennsylvania

    Science.gov (United States)

    Wood, C.R.

    1996-01-01

    In 1991, 99 of the 102 coal mines in the anthracite coal fields of Pennsylvania that discharged 1.0 cubic foot per second or more when water-quality samples were collected in 1975 were revisited. Water was not discharging from 15 of these 99 mines in 1991. Discharge, water temperature, specific conductance, pH, dissolved oxygen, sulfate, iron, manganese, alkalinity, and acidity were measured in water samples collected at 84 mines to assess changes in water quality from 1975 to 1991. The pH increased in water samples of 64 of the 81 mines. However, acidity was essentially unchanged. Concentrations of iron decreased in water discharge samples from 57 of 82 mines, manganese concentrations decreased in samples from 23 of 26 mines, and sulfate concentrations decreased in samples from 62 of 77 mines. The median change in sulfate was a decrease of 139 milligrams per liter. Alkalinity increased in water discharge samples from 43 mines, remained the same at 22 mines, and decreased at 14 mines. In 1975, the samples were collected during high base flow in the spring; in 1991, samples were collected during lower-than-normal base flow in the fall. This may have affected the comparison. Many mine discharges have elevated concentrations of aluminum, calcium, cobalt, iron, lithium, magnesium, manganese, nickel, strontium, zinc, and sulfate.

  5. Applicability of CFD Modelling in Determining Accurate Weir Discharge: Water Level Relationships

    NARCIS (Netherlands)

    Rombouts, P.M.M.; Tralli, A.; Langeveld, J.G.; Verhaart, F.; Clemens, F.H.L.R.

    2014-01-01

    Being able to accurately determine weir discharges is of key importance in urban water management. The most common method is performing a level measurement and calculating the discharge using the standard weir equation. Since this equation is only valid in certain conditions, this can lead to large

  6. Surface Partial Discharge Characteristics of Oil-paper Insulation Under Combined AC-DC Voltage

    Institute of Scientific and Technical Information of China (English)

    SHA Yanchao; ZHOU Yuanxiang; NIE Dexin; WU Zhirong; DENG Jiangang; LU Licheng

    2013-01-01

    The valve side windings of converter transformers bear AC,DC,impulse,and reversal-polarity voltages during operation,which could result in serious insulation problems of the equipment.By performing experiments with surface discharge model of oil-paper insulation at 80 ℃ under combined AC-DC voltage for 200 h,we studied the spectrums and statistical parameters of partial discharges at different discharge stages.Furthermore,some fingerprint parameters were calculated in order to estimate the development situation of partial discharge,while the characteristic gases dissolved in the transformer oil were measured by gas chromatography.The surface discharges in the experiments were observed using a high speed camera,and a full discharge process could be marked off into four stages as follows.①The elementary stage.When a partial discharge occurs near electrodes,electrical charges are injected into the region near electrodes and causing bubble generation.②Due to their high resistivity and low dielectric constant,the bubbles would bare the major part of the voltage applied to samples.Therefore,discharge happens inside the small bubbles,and it emits a lot of light.③Micmmolecules of gas are produced in discharge,and further ionization in the transformer oil takes place simultaneously when high-energy electrons collide with oil molecules.④The carrier charge moves forward to electrodes driven by the applied electric field,till they neutralize with the charge from electrodes,and hence discharge channels are formed subsequently.

  7. Two-dimensional simulation research of secondary electron emission avalanche discharge on vacuum insulator surface

    Science.gov (United States)

    Cai, Libing; Wang, Jianguo; Zhu, Xiangqin; Wang, Yue; Zhang, Dianhui

    2015-01-01

    Based on the secondary electron emission avalanche (SEEA) model, the SEEA discharge on the vacuum insulator surface is simulated by using a 2D PIC-MCC code developed by ourselves. The evolutions of the number of discharge electrons, insulator surface charge, current, and 2D particle distribution are obtained. The effects of the strength of the applied electric field, secondary electron yield coefficient, rise time of the pulse, length of the insulator on the discharge are investigated. The results show that the number of the SEEA electrons presents a quadratic dependence upon the applied field strength. The SEEA current, which is on the order of Ampere, is directly proportional to the field strength and secondary electron yield coefficient. Finally, the electron-stimulated outgassing is included in the simulation code, and a three-phase discharge curve is presented by the simulation, which agrees with the experimental data.

  8. Wastewater discharge degrades coastal waters and reef communities in southern Thailand.

    Science.gov (United States)

    Reopanichkul, Pasinee; Carter, R W; Worachananant, Suchai; Crossland, C J

    2010-06-01

    Runoff and sewage discharge from land developments can cause significant changes in water quality of coastal waters, resulting in coral degradation. Coastal waters around Phuket, Thailand are influenced by numerous sewage outfalls associated with rapid tourism development. Water quality and biological monitoring around the Phuket region was undertaken to quantify water quality and biotic characteristics at various distances from sewage outfalls. The surveys revealed strong gradients in water quality and biotic characteristics associated with tourism concentration levels as well as seasonal variability. Water and reef quality tended to decrease with increasing tourist intensity, but improved with increasing distance from sewage discharge within each of the three study locations. In addition, the effect of wastewater discharge was not localised around the source of pollution, but appeared to be transported to non-developed sites by currents, and exacerbated in the wet season.

  9. Surface charging, discharging and chemical modification at a sliding contact

    DEFF Research Database (Denmark)

    Singh, Shailendra Vikram; Kusano, Yukihiro; Morgen, Per

    2012-01-01

    -ray photoelectron spectroscopy (XPS). The experiments were performed on the disk surface of a ball-on-rotating-disk apparatus; using a glass disk and a Teflon (polytetrafluoroethylene) ball arrangement, and a polyester disks and a diamondlike carbon (DLC) coated steel ball arrangement. The capacitive probe...

  10. Gas-dynamic disturbances created by surface dielectric barrier discharge in the constricted mode

    Science.gov (United States)

    Moralev, I.; Boytsov, S.; Kazansky, P.; Bityurin, V.

    2014-05-01

    Three-dimensional structure of the gas-dynamic disturbances, created by surface dielectric barrier discharge in a constricted (saturated) mode, was analyzed simultaneously with the discharge morphology. Discharge was created in the still air under normal conditions. Flow visualization was performed by shadowgraphy and stereo-PIV technique. The wall-normal jets with the origins located in between the positions of the constricted filaments are found. Velocity magnitude in the wall-normal direction is comparable with the tangential component. Flow structure is similar to the one created by the serpentine actuator.

  11. Modification of the Steel Surface Treated by a Volume Discharge Plasma in Nitrogen at Atmospheric Pressure

    Science.gov (United States)

    Erofeev, M. V.; Shulepov, M. A.; Ivanov, Yu. F.; Oskomov, K. V.; Tarasenko, V. F.

    2016-03-01

    Effect of volume discharge plasma initiated by an avalanche electron beam on the composition, structure, and properties of the surface steel layer is investigated. Voltage pulses with incident wave amplitude up to 30 kV, full width at half maximum of about 4 ns, and wave front of about 2.5 ns were applied to the gap with an inhomogeneous electric field. Changes indicating the hardening effect of the volume discharge initiated by an avalanche electron beam are revealed in St3-grade steel specimens treated by the discharge of this type.

  12. Non-self-sustained discharge with hollow anode for plasma-based surface treatment

    Directory of Open Access Journals (Sweden)

    Misiruk Ivan O.

    2016-06-01

    Full Text Available The paper discusses plasma methods for surface modification using the non-self-sustained glow discharge with a hollow anode. This discharge is characterised by low voltage and high values of electron and ion currents. It can be easily excited in vacuum-arc installations that are widely used for coatings deposition. It is shown that such type of discharge may be effectively used for ion pumping, film deposition, ion etching, diffusion saturation of metallic materials, fusion and brazing of metals, and for combined application of above mentioned technologies in a single vacuum cycle.

  13. Second-harmonic plasma response in diffusion-controlled surface-wave-sustained discharges

    Science.gov (United States)

    Stoev, L.

    2008-05-01

    The formation of nonlinear plasma response at the second harmonic frequency in diffusion controlled surface-wave-sustained discharges is studied theoretically. The study is aimed at estimating theoretically the ratio of the squared amplitudes of the wave field of fundamental frequency and of the resulting - from the nonlinear effects - electric field at the second harmonic frequency. The model presented is intended for further use in discharge diagnostics.

  14. Partial discharge patterns related to surface deterioration in voids in epoxy

    OpenAIRE

    Holbøll, Joachim; Henriksen, Mogens

    1990-01-01

    Results are presented from an investigation of the relationship between changes in partial discharge patterns and the surface deterioration process taking place in small naturally formed spherical voids in epoxy plastic. The voids were exposed to a moderate electric stress above inception level, where partial discharges were present for more than 1500 h. Two types of electrical tree growth were found, the bush like tree and a single channel-like tree, which led to very different partial disch...

  15. Influence of Fine Metal Particles on Surface Discharge Characteristics of Outdoor Insulators

    Directory of Open Access Journals (Sweden)

    Yong Liu

    2016-01-01

    Full Text Available Focusing on the influence of fine metal particles on the insulation characteristics of outdoor insulators, spherical micrometer-level iron powders were used to represent fine metal particles of different parameters on a polymer insulator specimen surface. Dynamic movement and lift-off behavior of fine particles, as well as the triggered surface discharges under AC voltage were investigated in a uniform electric field under different experimental conditions. The results reveal that the inception, propagation and intensity of surface discharges are significantly affected by the particle parameters, including particle size, amount and distributing characteristic. Based on the measurement of light emission during the flashover process using a high-speed camera, the process of surface discharge to flashover triggered by the fine metal particles were investigated to obtain a relationship between flashover voltage, discharge light intensity and particle parameters. It is suggested that particle size smaller than 28 µm and particle amount more than 40 mg in contact with the non-uniform distribution can cause a significant distortion and intensification of the electric field resulting in a higher risk of surface discharges leading to flashover. Such investigations can enhance the operating reliability of outdoor insulators subjected to these conditions.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Contraction of Surface Barrier Discharge at Positive and Negative Polarities in Atmospheric Air

    Science.gov (United States)

    Leonov, Sergey; Houpt, Alec

    2016-10-01

    This experimental study of surface dielectric barrier discharge examines the morphology and charge transfer dynamics depending on the supplied voltage pattern: single polarity vs alternating polarity. Diagnostics included electrical measurements, camera imaging, optical emission spectroscopy, and a set of original charge sensors. Two basic modes were analyzed: diffusive and filamentary. The key factor of the discharge dynamics is the development of ionization instability causing the contraction of the discharge current and formation of the filamentary, highly conductive plasma during both positive and negative polarities. A main criterion of the discharge contraction is the generation of a zone with a high level of longitudinal electric field, not less than 15 kV/cm, realized during the alternating of the sign of surface charge. It is shown that the alternating polarity of the supplied voltage accompanied with the process of discharge contraction gives a significant benefit in the surface area covered by the discharge and in the power deposition, increasing it 2-4 times. FlowPAC Institute, University of Notre Dame.

  18. Surface Dielectric Barrier Discharge Jet for Skin Disinfection

    Science.gov (United States)

    Creyghton, Yves; Meijer, Rogier; Verweij, Paul; van der Zanden, Frank; Leenders, Paul

    A consortium consisting of the research institute TNO, the medical ­university and hospital St Radboud and two industrial enterprises is working on a non-thermal plasma treatment method for hand disinfection. The group is seeking for cooperation, in particular in the field of validation methods and potential ­standardization for plasma based disinfection procedures. The present paper describes technical progress in plasma source development together with initial microbiological data. Particular properties of the sheet shaped plasma volume are the possibility of treating large irregular surfaces in a short period of time, effective plasma produced species transfer to the surface together with high controllability of the nature of plasma species by means of temperature conditioning.

  19. Submarine groundwater discharge of total mercury and monomethylmercury to central California coastal waters.

    Science.gov (United States)

    Black, Friank J; Paytan, Adina; Knee, Karen L; De Sieyes, Nicholas R; Ganguli, Priya M; Gray, Ellen; Flegal, A Russell

    2009-08-01

    Fluxes of total mercury (Hg(T)) and monomethylmercury (MMHg) associated with submarine groundwater discharge (SGD) at two sites onthe central California coast were estimated by combining measurements of Hg(T) and MMHg in groundwater with the use of short-lived, naturally occurring radium isotopes as tracers of groundwater inputs. Concentrations of Hg(T) were relatively low, ranging from 1.2 to 28.3 pM in filtered groundwater, 0.8 to 11.6 pM in filtered surface waters, and 2.5 to 12.9 pM in unfiltered surface waters. Concentrations of MMHg ranged from < 0.04 to 3.1 pM in filtered groundwater, < 0.04 to 0.53 pM in filtered surface waters, and 0.07 to 1.2 pM in unfiltered surface waters. Multiple linear regression analysis identified significant (p < 0.05) positive correlations between dissolved groundwater concentrations of Hg(T) and those of NH4+ and SiO2, and between dissolved groundwater concentrations of MMHg and those of Hg(T) and NH4+. However, such relationships did not account for the majority of the variability in concentration data for either mercury species in groundwater. Fluxes of Hg(T) via SGD were estimated to be 250 +/- 160 nmol day m(-1) of shoreline at Stinson Beach and 3.0 +/- 2.0 nmol m(-2) day(-1) at Elkhorn Slough. These Hg(T) fluxes are substantially greater than net atmospheric inputs of Hg(T) reported for waters in nearby San Francisco Bay. Calculated fluxes of MMHg to coastal waters via SGD were 10 +/- 12 nmol day(-1) m(-1) of shoreline at Stinson Beach and 0.24 +/- 0.21 nmol m(-2) day at Elkhorn Slough. These MMHg fluxes are similar to benthic fluxes of MMHg out of surface sediments commonly reported for estuarine and coastal environments. Consequently, this work demonstrates that SGD is an important source of both Hg(T) and MMHg to coastal waters along the central California coast.

  20. Tailoring surface properties of polyethylene separator by low pressure 13.56 MHz RF oxygen plasma glow discharge

    Science.gov (United States)

    Li, Chun; Liang, Chia-Han; Huang, Chun

    2016-01-01

    Low-pressure plasma surface modification in a radio-frequency capacitively coupled glow discharge of oxygen gas was carried out to induce polar functional groups onto polyethylene membrane separator surfaces to enhance its hydrophilicity. The surface changes in surface free energy were monitored by static contact angle measurement. A significant increase in the surface energy of polyethylene membrane separators caused by the oxygen gas plasma modifications was observed. The static water contact angle of the plasma-modified membrane separator significantly decreased with the increase in treatment duration and plasma power. An obvious increase in the surface energy of the membrane separators owing to the oxidative effect of oxygen-gas-plasma modifications was also observed. Optical emission spectroscopy was carried out to analyze the chemical species generated by oxygen gas plasma surface modification. The variations in the surface morphology and chemical structure of the separators were confirmed by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy (XPS). XPS showed significantly higher surface concentrations of oxygen functional groups in the oxygen-gas-plasma-modified polymeric separator surfaces than in the unmodified polymeric separator surface. The experimental results show the important role of chemical species in the interaction between oxygen gas plasmas and the separator surface, which can be controlled by surface modification to tailor the hydrophilicity of the separator.

  1. Valorisation of discharge water from substrate-grown crops in greenhouses

    NARCIS (Netherlands)

    Balendonck, J.; Os, van E.A.; Ruijven, van J.P.M.; Lans, van der C.J.M.; Beerling, E.A.M.; Feenstra, L.

    2014-01-01

    Due to mismatch of nutrients, high sodium concentration, growth inhibition or system failures, greenhouse growers with substrate-grown crops tend to discharge their drain water. To comply with Water Framework regulations, in future, they must re-use drain water streams as much as possible. With memb

  2. Annual Report of Airborne Discharge Station for Treated Radioactive Waste Water with Tritium in 2015

    Institute of Scientific and Technical Information of China (English)

    HAN; Yi-dan; FENG; Chun-xiao; LONG; Bo-kang; ZHAO; Yu-hang; WANG; Jian-xin

    2015-01-01

    The airborne discharge station for radioactive purity liquid waste water is officially put into operation in 2010,and it is the first facility for treated radioactive waste water with tritium in China.The station is primarily based on the"air humidification"principle for treated waste water

  3. A method for the separation of total discharge into base flow, overland flow and channel precipitation for water quality modelling of a small watershed in the Netherlands

    NARCIS (Netherlands)

    Bleuten, W.

    1988-01-01

    For surface water quality modelling all contributing discharges, each with different loads of dissolved matter have to be considered separately. Apart from physical and (bio)chemical interactions, water quality is the result of all inputs, both in volume and mass. For this reason dynamic modelling o

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

    Science.gov (United States)

    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.

  5. Modification of GaAs surface by low-current Townsend discharge

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, E L; Kittel, S; Hergenroeder, R [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V., 44139 Dortmund (Germany); Astrov, Yu A; Portsel, L M; Lodygin, A N; Tolmachev, V A; Ankudinov, A V, E-mail: evgeny.gurevich@isas.d, E-mail: yuri.astrov@mail.ioffe.r [Ioffe Physico-Technical Institute, RAS, 194021 St Petersburg (Russian Federation)

    2010-07-14

    The influence of stationary spatially homogeneous Townsend discharge on the (1 0 0) surface of semi-insulating GaAs samples is studied. Samples exposed to both electrons and ions in a nitrogen discharge at a current density j = 60 {mu}A cm{sup -2} are studied by means of x-ray photoelectron spectroscopy, ellipsometry and atomic force microscopy. It is shown that an exposure to low-energy ions (<1 eV) changes the crystal structure of the semiconductor for a depth of up to 10-20 nm, although the stoichiometric composition does not change. The exposure to low-energy electrons (<10 eV) forms an oxide layer, which is 5-10 nm thick. Atomic force microscopy demonstrates that the change in the surface potential of the samples may exceed 100 mV, for both discharge polarities, while the surface roughness does not increase.

  6. Modification of GaAs surface by low-current Townsend discharge

    Science.gov (United States)

    Gurevich, E. L.; Kittel, S.; Hergenröder, R.; Astrov, Yu A.; Portsel, L. M.; Lodygin, A. N.; Tolmachev, V. A.; Ankudinov, A. V.

    2010-07-01

    The influence of stationary spatially homogeneous Townsend discharge on the (1 0 0) surface of semi-insulating GaAs samples is studied. Samples exposed to both electrons and ions in a nitrogen discharge at a current density j = 60 µA cm-2 are studied by means of x-ray photoelectron spectroscopy, ellipsometry and atomic force microscopy. It is shown that an exposure to low-energy ions (<1 eV) changes the crystal structure of the semiconductor for a depth of up to 10-20 nm, although the stoichiometric composition does not change. The exposure to low-energy electrons (<10 eV) forms an oxide layer, which is 5-10 nm thick. Atomic force microscopy demonstrates that the change in the surface potential of the samples may exceed 100 mV, for both discharge polarities, while the surface roughness does not increase.

  7. Discharge areas for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents discharge areas in the Death Valley regional ground-water flow system (DVRFS) transient model. Natural ground-water discharge occurs...

  8. Discharge areas for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents discharge areas in the Death Valley regional ground-water flow system (DVRFS) transient model. Natural ground-water discharge...

  9. Water molecules orientation in surface layer

    Science.gov (United States)

    Klingo, V. V.

    2000-08-01

    The water molecules orientation has been investigated theoretically in the water surface layer. The surface molecule orientation is determined by the direction of a molecule dipole moment in relation to outward normal to the water surface. Entropy expressions of the superficial molecules in statistical meaning and from thermodynamical approach to a liquid surface tension have been found. The molecules share directed opposite to the outward normal that is hydrogen protons inside is equal 51.6%. 48.4% water molecules are directed along to surface outward normal that is by oxygen inside. A potential jump at the water surface layer amounts about 0.2 volts.

  10. The Proposed Surface Water and Ocean Topography (SWOT) Mission

    Science.gov (United States)

    Fu, Lee-Lueng; Alsdorf, Douglas; Rodriguez, Ernesto; Morrow, Rosemary; Mognard, Nelly; Vaze, Parag; Lafon, Thierry

    2012-01-01

    A new space mission concept called Surface Water and Ocean Topography (SWOT) is being developed jointly by a collaborative effort of the international oceanographic and hydrological communities for making high-resolution measurement of the water elevation of both the ocean and land surface water to answer the questions about the oceanic submesoscale processes and the storage and discharge of land surface water. The key instrument payload would be a Ka-band radar interferometer capable of making high-resolution wide-swath altimetry measurement. This paper describes the proposed science objectives and requirements as well as the measurement approach of SWOT, which is baselined to be launched in 2019. SWOT would demonstrate this new approach to advancing both oceanography and land hydrology and set a standard for future altimetry missions.

  11. Roughness modification of surfaces treated by a pulsed dielectric barrier discharge

    CERN Document Server

    Dumitrascu, N; Apetroaei, N; Popa, G

    2002-01-01

    Local modifications of surface roughness are very important in many applications, as this surface property is able to generate new mechano-physical characteristics of a large category of materials. Roughness is one of the most important parameters used to characterize and control the surface morphology, and techniques that allow modifying and controlling the surface roughness present increasing interest. In this respect we propose the dielectric barrier discharge (DBD) as a simple and low cost method that can be used to induce controlled roughness on various surfaces in the nanoscale range. DBD is produced in helium, at atmospheric pressure, by a pulsed high voltage, 28 kV peak to peak, 13.5 kHz frequency and 40 W power. This type of discharge is a source of energy capable of modifying the physico-chemical properties of the surfaces without affecting their bulk properties. The discharge is characterized by means of electrical probes and, in order to analyse the heat transfer rate from the discharge to the tre...

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

    Science.gov (United States)

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

    2016-02-01

    Measurements of near-ice (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.

  13. Reactivity of water vapor in an atmospheric argon flowing post-discharge plasma torch

    CERN Document Server

    Collette, S; Reniers, F

    2016-01-01

    The reactivity of water vapor introduced in the flowing post-discharge of an RF atmospheric plasma torch is investigated through electrical characterization, optical emission spectroscopy and mass spectrometry measurements. Due to the technical features of the plasma torch, the post-discharge can be considered as divided into two regions: an inner region (inside the plasma torch device) where the water vapor is injected and an outer region which directly interacts with the ambient air. The main reactions induced by the injection of water vapor are identified as well as those indicative of the influence of the ambient air. Plausible pathways allowing the production of H, OH, O radicals and H2O2 are discussed as well as reactions potentially responsible for inhomogeneities and for a low DC current measured in the flowing post-discharge. Keywords: atmospheric post-discharge, H2O plasma reactivity, RF plasma torch

  14. Uptake and degradation of discharged produced water components in marine microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Brakstad, O.G.; Olsen, A.J.; Nordtug, T. [and others

    1996-12-31

    Produced waters from offshore oil production are a significant source of aromatic compounds discharged to the seawater. Exposure studies have revealed toxic effects of alkylated phenols and PAH compounds to various marine organisms. In this study the fate of aromatic compounds in seawater was investigated, using a dynamic exposure system which simulated dilution effects of discharged chemicals and {open_quotes}natural{close_quotes} conditions in the seawater recipient. {sup 14}C-labelled alkylated phenols (para-cresol) and polyaromatic hydrocarbons (PAH; naphthalene or phenanthrene) were applied to exposure tanks at sub-ppb concentrations by the aid of a computer-controlled injector device. Natural seawater, with normal seawater bacteria, cultures of the phytoplankton Isochrysis galbana, or the ciliate Euplotes bisulcatus, passed the exposure system at a residence time of approximately 5 hours, creating a short and defined exposure time between compounds and microorganisms. Compounds bound to or taken up by the organisms were collected on filters downstream the exposure system. The results showed that marine microorganisms may take up portions of aromatic compounds within a short period of time. Uptake mechanisms were expected to be passive events. Comparison of bioconcentration factors to the water-octanol coefficients of the components indicated alternative uptake mechanisms to a passive incorporation in the lipid membranes of the organisms. Binding to surface protein and carbohydrate moieties may play a central role during uptake. Studies in static systems with exposure of components to normal seawater bacteria showed a significant uptake and mineralization only for p-cresol. Standard seawater BOD testing indicated that all compounds tested were potentially biodegradable in normal non-acclimated seawater. The results demonstrate that uptake and degradation of produced water components are important to consider during studies of the fate of these components.

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

    Science.gov (United States)

    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.

  16. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment

  17. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment concentrati

  18. Rocky Mountain Arsenal surface water management plan : water year 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Surface Water Management Plan (SWMP) for Water Year 2003 (WY 2003) (October I, 2002 to September 30, 2003) is an assessment of the nonpotable water demands at...

  19. Rocky Mountain Arsenal surface water management plan : water year 2005

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Surface Water Management Plan for Water Year (WY) 2005 (October 1, 2004 to September 30, 2005) is an assessment of the nonpotable water demands at the Rocky...

  20. Rocky Mountain Arsenal surface water management plan : water year 2006

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Surface Water Management Plan for Water Year (WY) 2006 (October 1, 2005 to September 30, 2006) is an assessment of the nonpotable water demands at the Rocky...

  1. Effects of surface dielectric barrier discharge on aerodynamic characteristic of train

    Science.gov (United States)

    Dong, Lei; Gao, Guoqiang; Peng, Kaisheng; Wei, Wenfu; Li, Chunmao; Wu, Guangning

    2017-07-01

    High-speed railway today has become an indispensable means of transportation due to its remarkable advantages, including comfortability, convenience and less pollution. The increase in velocity makes the air drag become the main source of energy consumption, leading to receiving more and more concerns. The surface dielectric barrier discharge has shown some unique characteristics in terms of active airflow control. In this paper, the influences of surface dielectric barrier discharge on the aerodynamic characteristics of a scaled train model have been studied. Aspects of the discharge power consumption, the temperature distribution, the velocity of induced flow and the airflow field around the train model were considered. The applied AC voltage was set in the range of 20 kV to 28 kV, with a fixed frequency of 9 kHz. Results indicated that the discharge power consumption, the maximum temperature and the induced flow velocity increased with increasing applied voltage. Mechanisms of applied voltage influencing these key parameters were discussed from the point of the equivalent circuit. The airflow field around the train model with different applied voltages was observed by the smoke visualization experiment. Finally, the effects of surface dielectric barrier discharge on the train drag reduction with different applied voltages were analyzed.

  2. Water discharge during an Antarctic subglacial flood from CryoSat interferometric altimetry. (Invited)

    Science.gov (United States)

    McMillan, M.; Corr, H.; Shepherd, A.; Ridout, A.; Laxon, S.; Cullen, R.

    2013-12-01

    Beneath the Antarctic Ice Sheet lies a network of subglacial lakes which can store, and periodically release, some of the estimated 65 Gt of water generated annually by subglacial melting. These lakes produce a system of episodic mass transfer at the ice sheet base, with the capacity to alter the subglacial environment, the flow of overlying ice and the delivery of freshwater to the ocean. In this study, we use data acquired by the CryoSat-2 interferometric radar altimeter to map the perimeter and depth of a 260 km2 surface depression above an Antarctic subglacial lake (SGL). In combination with ICESat laser altimetry, we chart decadal changes in SGL volume. During 2007-2008, between 4.9 and 6.4 km3 of water drained from the SGL, and peak discharge exceeded 160 m3s-1. The flood was twice as large as any previously recorded, and equivalent to ~ 10 % of the meltwater generated annually beneath the ice sheet. The ice surface has since uplifted at a rate of 5.6 × 2.8 m yr-1. Our study demonstrates the ability of CryoSat-2 to provide detailed maps of ice sheet topography, its potential to accurately measure SGL drainage events, and the contribution it can make to understanding mass transport beneath the Antarctic Ice Sheet.

  3. Fast estimation of lacustrine groundwater discharge volumes based on stable water isotopes

    Science.gov (United States)

    Lewandowski, Jörg; Gercken, Jasper; Premke, Katrin; Meinikmann, Karin

    2017-04-01

    Lake eutrophication is still a severe problem in many parts of the world, commonly due to anthropogenic sources of nutrients such as fertilizer, manure or sewage. Improved quantification of nutrient inputs to lakes is required to address this problem. One possible input path for nutrients is lacustrine groundwater discharge (LGD). However, LGD has often been disregarded in water and nutrient budgets of lakes although some studies reveal an extraordinary importance of LGD for phosphorus inputs. The aim of the present study is to identify lakes that receive large LGD volumes compared to other input paths. Such lakes are more prone to high groundwater-borne nutrient inputs than lakes with small LGD volumes. . The simple and fast approach used in the present study is based on the fact that evaporation of surface water causes an enrichment of heavier isotopes in lake and river water while precipitation and groundwater are lighter and have similar isotopic signatures. The isotopic signature of lake water depends on a) the isotopic signature of its inputs and b) the lakés residence time (the longer the more enriched with heavier isotopes). In the present study we used the citizen science project "Tatort Gewässer" to let people collect lake water samples all over Germany. Based on additional information we identified lakes without or with small (compared to the lake volume) aboveground inflows. Based on the isotopic signatures of these lakes and additional background information such as the mean depth we could identify lakes in which groundwater is an important component of the water balance. The results will be used as a basis of intense research on groundwater-driven lake eutrophication.

  4. Investigation of Atmospheric Plasma Discharge and Its Application to Surface Modification of Textile Materials

    Institute of Scientific and Technical Information of China (English)

    TANG Xiao-liang; QIU Gao; FENG Xian-ping; YAN Yong-hui; SHI Yun-cheng; YAN Zhi-ren; WANG Liang

    2005-01-01

    In this paper, an improved quasi-stable atmospheric pressure dielectric barrier discharge (DBD) plasma source is achieved after carefully controlled discharge voltage and current, discharge power, working gas, treatment period,and gap between the electrodes. This plasma source has been used to modify the surface of Polybutylene Terephthalate (PBT) melt-blown nonwovens and Polyester(PET) fabrics, and the various influences on surface modification and the aging effeet of treated polymeric materials have been systematically investigated. In addition, the method of spectrum analysis is also used for diagnosing plasma parameters such as electron temperature.Experimental results indicate that both the wettablity and permeation of treated PBT melt-blown nonwovens and dyeing ability of treated PET fabrics are certainly improved.

  5. Investigation Of The High-Voltage Discharge On The Surface Of Gas-Liquid System

    Science.gov (United States)

    Nguyen-Kuok, Shi; Morgunov, Aleksandr; Malakhov, Yury; Korotkikh, Ivan

    2016-09-01

    This paper describes an experimental setup for study of physical processes in the high-voltage discharge on the surface of gas-liquid system at atmospheric pressure. Measurements of electrical and optical characteristics of the high-voltage discharge in gas, at the surface of the gas-liquid system and in the electrolyte are obtained. The parameters of the high-voltage discharge and the conditions for its stable operation are presented. Investigations with various electrolytes and cathode assemblies of various materials and sizes were carried out. The installation can be used for the processing and recycling of industrial and chemical liquid waste. Professor of Laboratory of Plasma Physics, National Research University MPEI, Krasnokazarmennya Str.14, 111250, Moscow, Russia.

  6. Simulation of Discharge Production in a Water Vapour Layer on an Electrode

    Science.gov (United States)

    Karim, Mohammad; Evans, Benjamin; Asimakoulas, Leonidas; Stalder, Kenneth; Field, Thomas; Graham, Bill; Murakami, Tomoyuki

    2016-09-01

    Electrical discharges in water are receiving increasing attention because of chemical, environmental and biomedical applications.The work to be presented focuses on plasmas created directly in high conductivity water, saline solution. Here the plasma is produced at low voltage ( 200V) and is clearly associated with an initial vapour layer on the electrode surface that isolates the electrode from the liquid. In a previous paper a finite element multi-physics program, incorporating all relevant electrical and thermal properties of the solution was shown to reproduce the experimentally observed pre-plasma vapour layer behaviour. The results of a simulation of the plasma production in vapour layers of the same size and shape as predicted in will be presented, At present inert gas fills the ``vapour layer''. However this produces spatial distributions of the electron parameters that are consistent with the electric fields predicted in the original simulations. The water plasma simulation recently developed by Murakami is currently being included. It is anticipated that results of the coupled codes, showing the temporal and 2-D spatial development of the vapour and plasma, will be presented.

  7. Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

    Directory of Open Access Journals (Sweden)

    Élise Euvrard

    2016-08-01

    Full Text Available In this study, a polymer, prepared by crosslinking cyclodextrin (CD by means of a polycarboxylic acid, was used for the removal of pollutants from spiked solutions and discharge waters from the surface treatment industry. In spiked solutions containing five metals, sixteen polycyclic aromatic hydrocarbons (PAH and three alkylphenols (AP, the material exhibited high adsorption capacities: >99% of Co2+, Ni2+ and Zn2+ were removed, between 65 and 82% of the PAHs, as well as 69 to 90% of the APs. Due to the structure of the polymer and its specific characteristics, such as the presence of carboxylic groups and CD cavities, the adsorption mechanism involves four main interactions: ion exchange, electrostatic interactions and precipitation for metal removal, and inclusion complexes for organics removal. In industrial discharge waters, competition effects appeared, especially because of the presence of calcium at high concentrations, which competed with other pollutants for the adsorption sites of the adsorbent.

  8. Suspended particle and pathogen peak discharge buffering by a surface-flow constructed wetland

    NARCIS (Netherlands)

    Mulling, B.T.M.; van den Boomen, R.M.; van der Geest, H.G.; Kappelhof, J.W.N.M.; Admiraal, W.

    2013-01-01

    Constructed wetlands (CWs) have been shown to improve the water quality of treated wastewater. The capacity of CWs to reduce nutrients, pathogens and organic matter and restore oxygen regime under normal operating conditions cannot be extrapolated to periods of incidental peak discharges. The

  9. Low pressure water vapour discharge as a light source: I. Spectroscopic characteristics and efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Artamonova, E; Artamonova, T; Beliaeva, A; Gorbov, D; Khodorkovskii, M; Melnikov, A; Milenin, V; Murashov, S; Rakcheeva, L; Timofeev, N [Saint-Petersburg State University, Ulyanovskaya 3, 198504 (Russian Federation); Michael, D [General Electric Global Research Center, One Research Circle (Bldg K1 Rm 4B31), Niskayuna, NY, 12309 (United States)], E-mail: timofeev@pobox.spbu.ru, E-mail: michael@crd.ge.com

    2008-08-07

    Spectral and electrical characteristics of a low pressure dc discharge formed from a mixture of one of the rare gases Ne, Ar or Kr plus water vapour are studied. Water vapour is only a minor additive to the rare gas. It has been shown that enhanced emission of the OH 306.4 nm band is registered from the discharge of Ar mixed with water vapour. Plasmas from the other investigated rare gases yielded considerably less OH 306.4 nm emission. Data about consumed electric power, spectra and relative efficiencies are presente000.

  10. Partial discharge patterns and surface deterioration in voids in filled and unfilled epoxy

    DEFF Research Database (Denmark)

    Holbøll, Joachim; Henriksen, Mogens

    1992-01-01

    Results are presented from analyses of pulses from partial discharges (PDs) in single spherical voids in filled and unfilled epoxy plastic and related to the observed surface deterioration. The filler types used were dolomite, alumina, and silica. Long-time aging tests including pulse phase...

  11. Evolution of nanosecond surface dielectric barrier discharge for negative polarity of a voltage pulse

    Science.gov (United States)

    Soloviev, V. R.; Krivtsov, V. M.; Shcherbanev, S. A.; Starikovskaia, S. M.

    2017-01-01

    Surface dielectric barrier discharge, initiated by a high-voltage pulse of negative polarity in atmospheric pressure air, is studied numerically and experimentally. At a pulse duration of a few tens of nanoseconds, two waves of optical emission propagate from the high-voltage electrode corresponding to the leading and trailing edges of the high-voltage pulse. It is shown by means of numerical modeling that a glow-like discharge slides along the surface of the dielectric at the leading edge of the pulse, slowing down on the plateau of the pulse. When the trailing edge of the pulse arrives to the high-voltage electrode, a second discharge starts and propagates in the same direction. The difference is that the discharge corresponding to the trailing edge is not diffuse and demonstrates a well-pronounced streamer-like shape. The 2D (in numerical modeling) streamer propagates above the dielectric surface, leaving a gap of about 0.05 mm between the streamer and the surface. The calculated and experimentally measured emission picture, waveform of the electrical current, and deposited energy, qualitatively coincide. The sensitivity of the numerical solution to unknown physical parameters of the model is discussed.

  12. Quantitative Analysis on Carbon Migration in Double-Glow Discharge Plasma Surface Alloying Process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhen-xia; WANG Cong-zeng; ZHANG Wen-quan; SU Xue-kuan

    2004-01-01

    Carbon migration is of great significance in double-glow discharge plasma surface alloying process, but literature of quantitative analysis about carbon migration is relatively scarce. In this paper differential equations of the carbon and metal concentration distribution were established. By means of differential equations carbon migration was described and a numerical solution was acquired. The computational results fit the experiment results quite well.

  13. Pollutant removal from industrial discharge water using individual and combined effects of adsorption and ion-exchange processes: Chemical abatement

    Directory of Open Access Journals (Sweden)

    Jérémie Charles

    2016-03-01

    Full Text Available In this study, adsorption-oriented processes for pollutant removal from metal polycontaminated surface-finishing discharge water were applied individually as well as in combination with ion-exchange treatment to remove the remaining metal ions and organic load. Several materials were compared using batch experiments, namely an activated carbon, three ion-exchange resins (IRA 402Cl, IR 120H and TP 207, and two non-conventional cross-linked polysaccharide-based biosorbents (starch and cyclodextrin. This article presents the abatements obtained in chemical pollution as monitored by complete chemical analysis. For the same experimental conditions (similar discharge water, pollutant concentrations, stirring rate, contact time, and initial pH, the highest levels of pollutant removal were attained with the combined use of two materials, an activated carbon and a mixture of two ion-exchange resins. This physicochemical treatment effectively lowered the main pollutants present in the discharge water such as Cu, Ni and COD, by more than 96%, 79% and 74% respectively (average values for three samples, while the treatment with carbon alone lowered them by 58%, 9% and 70%, and resins alone by 85%, 61% and 16%. Similar interesting results were obtained with the cyclodextrin-based adsorbent and its use alone was sufficient to obtain decreases in Cu, Ni and COD of more than 94%, 77% and 67% respectively. The adsorption-oriented process using cyclodextrin polymer could be an advantageous approach for removing organic and metallic pollutants from metal surface-finishing discharge water due to the non-toxic character of CD to humans and the environment.

  14. Natural Attenuation of Chlorinated Solvent Ground-Water Plumes Discharging into Wetlands

    Science.gov (United States)

    2003-09-01

    ground water in highly saline wetlands (Swanson et al., 1984), and the distribution of marsh marigold (Caltha palustris L.) has been used to map...seeps and springs next to a lake and in wetlands in Minnesota (Rosenberry et al., 2000). Marsh marigold favors ground-water discharge areas across the

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

    Science.gov (United States)

    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

    2015-06-06

    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.

  16. ASSESSMENT OF SURFACE WATER QUALITY IN AN ARSENIC CONTAMINATED VILLAGE

    Directory of Open Access Journals (Sweden)

    Kumud C. Saikia

    2012-01-01

    Full Text Available Arsenic contamination of ground water has occurred in various parts of the world, becoming a menace in the Ganga-Meghna-Brahmaputra basin (West Bengal and Assam in India and Bangladesh. Recently arsenic has been detected in Cachar and Karimganj districts of barak valley, Assam, bordering Bangladesh. In this area coli form contamination comprises the major constraint towards utilization of its otherwise ample surface water resources. The local water management exploited ground water sources using a centralized piped water delivery scheme without taking into account the geologically arsenic-prone nature of the sediments and aquifers in this area. Thus surface water was the suggestive alternative for drinking water in this area. The present study investigated surface water quality and availability in a village of Karimganj district, Assam, India contaminated with arsenic for identifying the potential problems of surface water quality maintenance so that with effective management safe drinking water could be provided. The study revealed that the area was rich in freshwater ecosystems which had all physico-chemical variables such as water temperature, pH, DO, total alkalinity, free CO2, heavy metals like lead, chromium and cadmium within WHO standards. In contrast, coli form bacteria count was found far beyond permissible limit in all the sources. Around 60% people of the village preferred ground water for drinking and only 6% were aware of arsenic related problems. The problem of bacterial contamination could be controlled by implementing some ameliorative measures so that people can safely use surface water. Inhabitants of the two districts should be given proper education regarding arsenic contamination and associated health risk. Effluents should be treated to acceptable levels and standards before discharging them into natural streams.

  17. Application of remote sensing techniques for monitoring the thermal pollution of cooling-water discharge from nuclear power plant.

    Science.gov (United States)

    Chen, Chuqun; Shi, Ping; Mao, Qingwen

    2003-08-01

    This article introduces a practical method to investigate thermal pollution in coastal water from satellite data. The intensity and distribution areas of thermal pollution by the heated effluent discharge from the nuclear power plant on Daya Bay, southern China were investigated by using Landsat-5 Thematic Mapper (TM) thermal band data from 1994 to 2001. A local algorithm was developed, based on sea-truth data of water surface temperature measured when the satellite passed over the study area. The local algorithm was then applied to estimate water temperature from TM data. It shows that the remote sensing technique provides an effective means to quantitatively monitor the intensity of thermal pollution and to retrieve a very detailed distribution pattern of thermal pollution in coastal waters. The remotely-sensed results of the thermal pollution can be used for environmental management of coastal waters.

  18. Discharge of water containing waste emanating from land to the ...

    African Journals Online (AJOL)

    driniev

    The DWAF as public trustee of the water resources in South. Africa must ... that freshwater (including groundwater), the coast and the sea are inseparably .... the international market where first world standards apply should not be ignored.

  19. Purification of inkjet ink from water using liquid phase, electric discharge polymerization and cellulosic membrane filtration.

    Science.gov (United States)

    Jordan, Alexander T; Hsieh, Jeffery S; Lee, Daniel T

    2013-01-01

    A method to separate inkjet ink from water was developed using a liquid phase, electric discharge process. The liquid phase, electric discharge process with filtration or sedimentation was shown to remove 97% of inkjet ink from solutions containing between 0.1-0.8 g/L and was consistent over a range of treatment conditions. Additionally, particle size analysis of treated allyl alcohol and treated propanol confirmed the electric discharge treatment has a polymerization mechanism, and small molecule analysis of treated methanol using gas chromatography and mass spectroscopy confirmed the mechanism was free radical initiated polymerization.

  20. Aqueous reactive species induced by a surface air discharge: Heterogeneous mass transfer and liquid chemistry pathways.

    Science.gov (United States)

    Liu, D X; Liu, Z C; Chen, C; Yang, A J; Li, D; Rong, M Z; Chen, H L; Kong, M G

    2016-04-01

    Plasma-liquid interaction is a critical area of plasma science and a knowledge bottleneck for many promising applications. In this paper, the interaction between a surface air discharge and its downstream sample of deionized water is studied with a system-level computational model, which has previously reached good agreement with experimental results. Our computational results reveal that the plasma-induced aqueous species are mainly H(+), nitrate, nitrite, H2O2 and O3. In addition, various short-lived aqueous species are also induced, regardless whether they are generated in the gas phase first. The production/loss pathways for aqueous species are quantified for an air gap width ranging from 0.1 to 2 cm, of which heterogeneous mass transfer and liquid chemistry are found to play a dominant role. The short-lived reactive oxygen species (ROS) and reactive nitrogen species (RNS) are strongly coupled in liquid-phase reactions: NO3 is an important precursor for short-lived ROS, and in turn OH, O2(-) and HO2 play a crucial role for the production of short-lived RNS. Also, heterogeneous mass transfer depends strongly on the air gap width, resulting in two distinct scenarios separated by a critical air gap of 0.5 cm. The liquid chemistry is significantly different in these two scenarios.

  1. Aqueous reactive species induced by a surface air discharge: Heterogeneous mass transfer and liquid chemistry pathways

    Science.gov (United States)

    Liu, D. X.; Liu, Z. C.; Chen, C.; Yang, A. J.; Li, D.; Rong, M. Z.; Chen, H. L.; Kong, M. G.

    2016-01-01

    Plasma-liquid interaction is a critical area of plasma science and a knowledge bottleneck for many promising applications. In this paper, the interaction between a surface air discharge and its downstream sample of deionized water is studied with a system-level computational model, which has previously reached good agreement with experimental results. Our computational results reveal that the plasma-induced aqueous species are mainly H+, nitrate, nitrite, H2O2 and O3. In addition, various short-lived aqueous species are also induced, regardless whether they are generated in the gas phase first. The production/loss pathways for aqueous species are quantified for an air gap width ranging from 0.1 to 2 cm, of which heterogeneous mass transfer and liquid chemistry are found to play a dominant role. The short-lived reactive oxygen species (ROS) and reactive nitrogen species (RNS) are strongly coupled in liquid-phase reactions: NO3 is an important precursor for short-lived ROS, and in turn OH, O2− and HO2 play a crucial role for the production of short-lived RNS. Also, heterogeneous mass transfer depends strongly on the air gap width, resulting in two distinct scenarios separated by a critical air gap of 0.5 cm. The liquid chemistry is significantly different in these two scenarios. PMID:27033381

  2. Impact of water and sediment discharges on subaqueous delta evolution in Yangtze Estuary from 1950 to 2010

    Directory of Open Access Journals (Sweden)

    Yun-ping YANG

    2014-07-01

    Full Text Available In order to determine how the subaqueous delta evolution depends on the water and sediment processes in the Yangtze Estuary, the amounts of water and sediment discharged into the estuary were studied. The results show that, during the period from 1950 to 2010, there was no significant change in the annual water discharge, and the multi-annual mean water discharge increased in dry seasons and decreased in flood seasons. However, the annual sediment discharge and the multi-annual mean sediment discharge in flood and dry seasons took on a decreasing trend, and the intra-annual distribution of water and sediment discharges tended to be uniform. The evolution process from deposition to erosion occurred at the ?10 m and ?20 m isobaths of the subaqueous delta. The enhanced annual water and sediment discharges had a silting-up effect on the delta, and the effect of sediment was greater than that of water. Based on data analysis, empirical curves were built to present the relationships between the water and sediment discharges over a year or in dry and flood seasons and the erosion/deposition rates in typical regions of the subaqueous delta, whose evolution followed the pattern of silting in flood seasons and scouring in dry seasons. Notably, the Three Gorges Dam has changed the distribution processes of water and sediment discharges, and the dam’s regulating and reserving functions can benefit the subaqueous delta deposition when the annual water and sediment discharges are not affected.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  5. Water surface capturing by image processing

    Science.gov (United States)

    An alternative means of measuring the water surface interface during laboratory experiments is processing a series of sequentially captured images. Image processing can provide a continuous, non-intrusive record of the water surface profile whose accuracy is not dependent on water depth. More trad...

  6. Optical Emission Spectroscopy Investigation of a Surface Dielectric Barrier Discharge Plasma Aerodynamic Actuator

    Institute of Scientific and Technical Information of China (English)

    LI Ying-Hong; WU Yun; JIA Min; ZHOU Zhang-Wen; GUO Zhi-Gang; PU Yi-Kang

    2008-01-01

    The optical emission spectroscopy of a surface dielectric barrier discharge plasma aerodynamic actuator is investigated with different electrode configurations, applied voltages and driving frequencies. The rotational temperature of N2 (C3IIu) molecule is calculated according to its rotational emission band near 380.5 nm. The average electron energy of the discharge is evaluated by emission intensity ratio of first negative system to second positive system of N2. The rotational temperature is sensitive to the inner space of an electrode pair. The average electron energy shows insensitivity to the applied voltage, the driving frequency and the electrode configuration.

  7. Stabilization of a cold cathode electron beam glow discharge for surface treatment

    Energy Technology Data Exchange (ETDEWEB)

    Mingolo, N.; Gonzalez, C.R. [Lab. de Haces Dirigidos, Depto. de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina); Martinez, O.E. [Lab. de Electronica Cuantica, Depto. de Fisica, Universidad de Buenos Aires, Pabellon 1, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Rocca, J.J. [Department of Electrical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)

    1997-10-01

    We have demonstrated that the reproducibility of electron beam pulses generated by a high power, cold cathode glow discharge is greatly improved by adding a small continuous keep-alive discharge current. A current of the order of 200 {mu}A was found to limit the shot to shot current variation to within 1.5{percent}. This stabilization in turn reduces by an order of magnitude the fluctuations of the energy density deposited on the target, demonstrating a reliable energy source for surface treatment. {copyright} {ital 1997 American Institute of Physics.}

  8. Experimental investigation of Lissajous figure shapes in planar and surface dielectric barrier discharges

    Science.gov (United States)

    Biganzoli, I.; Barni, R.; Gurioli, A.; Pertile, R.; Riccardi, C.

    2014-11-01

    Dielectric Barrier Discharges (DBDs) operating in air at atmospheric pressure are widely employed as cold plasma sources for plasma processing and applications, in both volume and surface configurations. Surface dielectric barrier discharges, however, are mainly known for the manipulation of the boundary layer of an airflow surrounding a body, and thus for aeronautical applications. Lissajous figures, obtained by means of a high-voltage and a capacitive probes, are usually adopted for both these types of DBDs as a method for measuring the power consumption by the discharge. In this work, we propose to integrate this diagnostic tool with the measurement of current pulses, which are associated to microdischarges that usually develop in these plasmas because of the presence of the dielectric barrier. We have studied both planar and surface DBDs in presence of a continuous sinusoidal voltage feeding, and we have demonstrated that this method is promising in order to gain additional information about the discharge characteristics from the shape of the Lissajous figures.

  9. Modelling total sewage water discharge to a regional treatment plant.

    NARCIS (Netherlands)

    Witter, J.V.; Stricker, H.

    1986-01-01

    In the Netherlands, sewage water is often treated on a regional basis. In case of combined systems that are spread within a large region of several hundreds of square kilometers, reduction of the hydraulic capacity of the regional treatment plant seems possible, because of space-time variations in r

  10. Surface performance of workpieces processed by electrical discharge machining in gas

    Institute of Scientific and Technical Information of China (English)

    LI Li-qing; BAI Ji-cheng; GUO Yong-feng; WANG Zhen-long

    2009-01-01

    The surface performance of workpieces processed by electrical discharge machining in gas (dry EDM) was studied in this paper. Firstly, the composition, micro hardness and recast layer of electrical discharge machined (EDMed) surface of 45 carbon steels in air were investigated through different test analysis methods. The results show that the workpiece surface EDMed in air contains a certain quantity of oxide, and oxidation occurs on the workpiece surface. Compared with the surface of workpieces processed in kerosene, fewer cracks exist on the dry EDMed workpiece surface, and the surface recast layer is thinner than that obtained by conventional EDM. The micro hardness of workpieces machined by dry EDM method is lower than that machined in kerosene, and higher than that of the matrix. In addition, experiments were conducted on the surface wear resistance of workpieces processed in air and kerosene using copper electrode and titanium alloy electrode.The results indicate that the surface wear resistance of workpieces processed in air can be improved, and it is related with tool material and dielectric.

  11. Synergistic effect of pulsed corona discharges and ozonation on decolourization of methylene blue in water

    CERN Document Server

    Malik, M A; Ghaffar, A; Ahmed, K

    2002-01-01

    The effect of O sub 2 and O sub 3 bubbling on decolourization of methylene blue by pulsed corona discharges in water was studied. The pulsed corona discharges were produced by charging an 80 pF capacitor with a 40 kV DC source, through a 100 M OMEGA resistor, and discharging it into a needle-plate type reactor at 60 Hz through a rotating spark gap switch. A 20 ml sample of 13.25 mg l sup - sup 1 methylene blue in distilled water was decolourized in 120 min. Bubbling O sub 2 at 10 ml min sup - sup 1 through the discharge region reduced the decolourization time to 25 min. Bubbling O sub 2 containing 1500 mu mol O sub 3 l sup - sup 1 at 10 ml min sup - sup 1 reduced the decolourization time to 8 min. The O sub 3 was produced by fractionating input energy between a water treatment reactor and a O sub 3 generator, i.e. no additional energy was consumed for O sub 3 production. Under the same experimental conditions methylene blue solution in tap water was decolourized in >210 min by corona discharge in solution, in...

  12. Plasma processes in water under effect of short duration pulse discharges

    Science.gov (United States)

    Gurbanov, Elchin

    2013-09-01

    It is very important to get a clear water without any impurities and bacteria by methods, that don't change the physical and chemical indicators of water now. In this article the plasma processes during the water treatment by strong electric fields and short duration pulse discharges are considered. The crown discharge around an electrode with a small radius of curvature consists of plasma leader channels with a high conductivity, where the thermo ionization processes and UV-radiation are taken place. Simultaneously the partial discharges around potential electrode lead to formation of atomic oxygen and ozone. The spark discharge arises, when plasma leader channels cross the all interelectrode gap, where the temperature and pressure are strongly grown. As a result the shock waves and dispersing liquid streams in all discharge gap are formed. The plasma channels extend, pressure inside it becomes less than hydrostatic one and the collapse and UV-radiation processes are started. The considered physical processes can be successfully used as a basis for development of pilot-industrial installations for conditioning of drinking water and to disinfecting of sewage.

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

    Directory of Open Access Journals (Sweden)

    Min Ho Kang

    Full Text Available 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.

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

    Science.gov (United States)

    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

  15. Radiating dipole model of interference induced in spacecraft circuitry by surface discharges

    Science.gov (United States)

    Metz, R. N.

    1984-01-01

    Spacecraft in geosynchronous orbit can be charged electrically to high voltages by interaction with the space plasma. Differential charging of spacecraft surfaces leads to arc and blowoff discharging. The discharges are thought to upset interior, computer-level circuitry. In addition to capacitive or electrostatic effects, significant inductive and less significant radiative effects of these discharges exist and can be modeled in a dipole approximation. Flight measurements suggest source frequencies of 5 to 50 MHz. Laboratory tests indicate source current strengths of several amperes. Electrical and magnetic fields at distances of many centimeters from such sources can be as large as tens of volts per meter and meter squared, respectively. Estimates of field attenuation by spacecraft walls and structures suggest that interior fields may be appreciable if electromagnetic shielding is much thinner than about 0.025 mm (1 mil). Pickup of such fields by wires and cables interconnecting circuit components could be a source of interference signals of several volts amplitude.

  16. Surface-initiated graft polymerization on multiwalled carbon nanotubes pretreated by corona discharge at atmospheric pressure.

    Science.gov (United States)

    Xu, Lihua; Fang, Zhengping; Song, Ping'an; Peng, Mao

    2010-03-01

    Surface-initiated graft polymerization on multi-walled carbon nanotubes pretreated with a corona discharge at atmospheric pressure was explored. The mechanism of the corona-discharge-induced graft polymerization is discussed. The results indicate that MWCNTs were encapsulated by poly(glycidyl methacrylate) (PGMA), demonstrating the formation of PGMA-grafted MWCNTs (PGMA-g-MWCNTs), with a grafting ratio of about 22 wt%. The solubility of PGMA-g-MWCNTs in ethanol was dramatically improved compared to pristine MWCNTs, which could contribute to fabricating high-performance polymer/MWCNTs nanocomposites in the future. Compared with most plasma processes, which operate at low pressures, corona discharge has the merit of working at atmospheric pressure.

  17. Bioactive surface modifications on inner walls of poly-tetra-fluoro-ethylene tubes using dielectric barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Ki [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Heat Treatment and Surface Engineering R and D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Park, Daewon; Kim, Hoonbae [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Hyerim; Park, Heonyong [Department of Molecular Biology, Dankook University, Yongin 448-701 (Korea, Republic of); Kim, Hong Ja [Department of Internal Medicine, Dankook University, Cheonan 330-714 (Korea, Republic of); Jung, Donggeun, E-mail: djung@skku.ac.kr [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-03-01

    Graphical abstract: - Highlights: • The surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts. • Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment using micro plasma discharge. - Abstract: Bioactive surface modification can be used in a variety of medical polymeric materials in the fields of biochips and biosensors, artificial membranes, and vascular grafts. In this study, the surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts, which are made of biocompatible material for the human body in the medical field. Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment on the PFTE surface using micro plasma discharge. Micro plasma was generated by a medium-frequency alternating current high-voltage generator. The preliminary modification of PTFE was conducted by a plasma of hydrogen and argon gases. The hydrocarbon thin film was deposited on modified PTFE with a mixture of acetylene and argon gases. The reactive plasma treatment using oxygen plasma was done to give biocompatible functionality to the inner wall surface. The hydrophobic surface of bare PTFE is made hydrophilic by the reactive plasma treatment due to the formation of carbonyl groups on the surface. The reactive treatment could lead to improved attachment of smooth muscle cells (SMCs) on the modified PTFE tubing. Fourier transform infrared absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle measurement were used for the analysis of the surface modification. The SMC-attached PTFE tube developed will be applicable to in vitro human vasculature

  18. Characterization of surface dielectric barrier discharge influenced by intermediate frequency for ozone production

    Science.gov (United States)

    Abdelaziz, Ayman A.; Ishijima, Tatsuo; Seto, Takafumi; Osawa, Naoki; Wedaa, Hassan; Otani, Yoshio

    2016-06-01

    The aim of this study is to investigate the effect of the intermediate frequency (1-10 kHz) of the sinusoidal driving voltage on the characteristics of a developed surface dielectric barrier discharge (SDBD)-based reactor having spikes on its discharge electrode. Moreover, its influence on the production of ozone and nitrogen oxide byproducts is evaluated. The results show that SDBD is operated in the filamentary mode at all the frequencies. Nevertheless, the pulses of the discharge current at high frequencies are much denser and have higher amplitudes than those at low frequencies. The analysis of the power consumed in the reactor shows that a small portion of the input power is dissipated in the dielectric material of SDBD source, whereas the major part of the power is consumed in the plasma discharge. The results of the ozone production show that higher frequencies have a slightly adverse effect on the ozone production at relatively high energy density values, where the ozone concentration is slightly decreased when the frequency is increased at the same energy density. The temperature of the discharge channels and gas is not a crucial factor for the decomposition of ozone in this reactor, while the results of the measurements of nitrogen oxides characteristics indicate that the formation of NO and NO2 has a significant adverse effect on the production efficiency of ozone due to their oxidation to another nitrogen oxides and their catalytic effect.

  19. Evolution of surface velocities and ice discharge of Larsen B outlet glaciers from 1995 to 2013

    Directory of Open Access Journals (Sweden)

    J. Wuite

    2014-12-01

    Full Text Available We use repeat-pass SAR data to produce detailed maps of surface motion covering the glaciers draining into the former Larsen B ice shelf, Antarctic Peninsula, for different epochs between 1995 and 2013. We combine the velocity maps with estimates of ice thickness to analyze fluctuations of ice discharge. The collapse of the central and northern sections of the ice shelf in 2002 led to a near-immediate acceleration of tributary glaciers as well as of the remnant ice shelf in Scar Inlet. Velocities of the glaciers discharging directly into the ocean remain to date well above the velocities of the pre-collapse period. The response of individual glaciers differs and velocities show significant temporal fluctuations, implying major variations in ice discharge and mass balance as well. Due to reduced velocity and ice thickness the ice discharge of Crane Glacier decreased from 5.02 Gt a−1 in 2007 to 1.72 Gt a−1 in 2013, whereas Hektoria and Green glaciers continue to show large temporal fluctuations in response to successive stages of frontal retreat. The velocity on Scar Inlet ice shelf increased two- to three fold since 1995, with the largest increase in the first years after the break-up of the main section of Larsen B. Flask and Leppard glaciers, the largest tributaries to Scar Inlet ice shelf, accelerated. In 2013 their discharge was 38%, respectively 45%, higher than in 1995.

  20. Evolution of surface velocities and ice discharge of Larsen B outlet glaciers from 1995 to 2013

    Science.gov (United States)

    Wuite, J.; Rott, H.; Hetzenecker, M.; Floricioiu, D.; De Rydt, J.; Gudmundsson, G. H.; Nagler, T.; Kern, M.

    2015-05-01

    We use repeat-pass SAR data to produce detailed maps of surface motion covering the glaciers draining into the former Larsen B Ice Shelf, Antarctic Peninsula, for different epochs between 1995 and 2013. We combine the velocity maps with estimates of ice thickness to analyze fluctuations of ice discharge. The collapse of the central and northern sections of the ice shelf in 2002 led to a near-immediate acceleration of tributary glaciers as well as of the remnant ice shelf in Scar Inlet. Velocities of most of the glaciers discharging directly into the ocean remain to date well above the velocities of the pre-collapse period. The response of individual glaciers differs and velocities show significant temporal fluctuations, implying major variations in ice discharge as well. Due to reduced velocity and ice thickness the ice discharge of Crane Glacier decreased from 5.02 Gt a-1 in 2007 to 1.72 Gt a-1 in 2013, whereas Hektoria and Green glaciers continue to show large temporal fluctuations in response to successive stages of frontal retreat. The velocity on Scar Inlet ice shelf increased 2-3-fold since 1995, with the largest increase in the first years after the break-up of the main section of Larsen B. Flask and Leppard glaciers, the largest tributaries to Scar Inlet ice shelf, accelerated. In 2013 their discharge was 38% and 46% higher than in 1995.

  1. Nanosecond Discharge in Bubbled Liquid n-Heptane: Effects of Gas Composition and Water Addition

    KAUST Repository

    Hamdan, Ahmad

    2016-08-30

    Recently, an aqueous discharge reactor was developed to facilitate reformation of liquid fuels by in-liquid plasma. To gain a microscopic understanding of the physical elements behind this aqueous reactor, we investigate nanosecond discharges in liquid n-heptane with single and double gaseous bubbles in the gap between electrodes. We introduce discharge probability (DP) to characterize the stochastic nature of the discharges, and we investigate the dependence of DP on the gap distance, applied voltage, gaseous bubble composition, and the water content in n-heptane/distilled-water emulsified mixtures. Propagation of a streamer through the bubbles indicates no discharges in the liquids. DP is controlled by the properties of the gaseous bubble rather than by the composition of the liquid mixture in the gap with a single bubble; meanwhile, DP is determined by the dielectric permittivity of the liquid mixture in the gap with double bubbles, results that are supported by static electric field simulations. We found that a physical mechanism of increasing DP is caused by an interaction between bubbles and an importance of the dielectric permittivity of a liquid mixture on the local enhancement of field intensity. We also discuss detailed physical characteristics, such as plasma lifetime and electron density within the discharge channel, by estimating from measured emissions with a gated-intensified charge-coupled device and by using spectroscopic images, respectively. © 1973-2012 IEEE.

  2. Ground water discharge and the related nutrient and trace metal fluxes into Quincy Bay, Massachusetts

    Science.gov (United States)

    Poppe, L.J.; Moffett, A.M.

    1993-01-01

    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 m3 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 we]l 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.

  3. Does Water Management Reduce uncertainty of Projected Climate Change Impacts on River Discharge?

    Science.gov (United States)

    Pohle, I.; Koch, H.; Gaedeke, A.; Hinz, C.; Grünewald, U.

    2015-12-01

    Climate change impact studies are associated with error propagation and amplification of uncertainties through model chains. Water management, especially reservoir management, reduces discharge variability. In this study we investigated how water management influences uncertainty propagation of climate change scenarios. We applied a model ensemble of (i) the regional climate model STAR (STAR 0K: no further climate change, STAR 2K and 3K: increase of mean annual temperature by 2 K and 3 K resp.; each scenario is represented by 100 realizations), (ii) the hydrological models SWIM and EGMO, and (iii) the water management model WBalMo. The study was performed in the two neighbouring catchments of the Schwarze Elster River (Germany) and the Spree River (Germany and Czech Republic). These catchments have similar climate, topography and land use, but differ in their water management. The Spree River has a higher reservoir capacity, more withdrawals and discharges from water users and more water transfers. The projected natural runoff in both catchments is similar. Compared to STAR 0K, the natural runoff decreases remarkably in the other climate scenarios. The uncertainties related to the climate projection are propagated through the hydrological model. In the Schwarze Elster River catchment, these uncertainties are slightly increased by the water management model, whereas in the Spree River catchment, due to a higher reservoir capacity and more water transfers, interannual variability and uncertainty of managed discharge are strongly moderated by water management. The results of this study imply that generally, effective water management can reduce uncertainty related to climate change impacts on river discharge. Catchments with a high storage ratio are less vulnerable to changing climate conditions. This underlines the role of water management in coping with climate change impacts. Yet, due to decreasing reservoir volumes in drought periods, reservoir management alone

  4. Multi-Parameter Analysis of Surface Finish in Electro-Discharge Machining of Tool Steels

    Directory of Open Access Journals (Sweden)

    Cornelia Victoria Anghel

    2006-10-01

    Full Text Available The paper presents a multi- parameter analysis of surface finish imparted to tool-steel plates by electro-discharge machining (EDM is presented. The interrelationship between surface texture parameters and process parameters is emphasized. An increased number of parameters is studied including amplitude, spacing, hybrid and fractal parameters,, as well. The correlation of these parameters with the machining conditions is investigated. Observed characteristics become more pronounced, when intensifying machining conditions. Close correlation exists between certain surface finish parameters and EDM input variables and single and multiple statistical regression models are developed.

  5. Pin Hole Discharge Creation in Na2SO4 Water Solutions

    Directory of Open Access Journals (Sweden)

    Lucie Hlavatá

    2013-01-01

    Full Text Available This work deals with the diaphragm discharge generated in water solutions containing Na2SO4 as a supporting electrolyte. The solution conductivity was varied in the range of 270 ÷ 750 µScm-1. The batch plasma reactor with volume of 100 ml was divided into two electrode spaces by the Shapal-MTM ceramics dielectric barrier with a pin-hole (diameter of 0.6 mm. Three variable barrier thicknesses (0.3; 0.7 and 1.5 mm and non-pulsed DC voltage up to 2 kV were used for the discharge creation. Each of the current–voltage characteristic can be divided into three parts: electrolysis, bubble formation and discharge operation. The experimental results showed that the discharge ignition moment in the pin-hole was significantly dependent on the dielectric diaphragm thickness. Breakdown voltage increases with the increase of the dielectric barrier thickness.

  6. Safe Drinking Water Information System (SDWIS) Surface Water Intakes

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is a point feature dataset showing the locations of surface water intakes. These intake locations are part of the safe drinking water information system...

  7. Near-surface Heating of Young Rift Sediment Causes Mass Production and Discharge of Reactive Dissolved Organic Matter.

    Science.gov (United States)

    Lin, Yu-Shih; Koch, Boris P; Feseker, Tomas; Ziervogel, Kai; Goldhammer, Tobias; Schmidt, Frauke; Witt, Matthias; Kellermann, Matthias Y; Zabel, Matthias; Teske, Andreas; Hinrichs, Kai-Uwe

    2017-03-22

    Ocean margin sediments have been considered as important sources of dissolved organic carbon (DOC) to the deep ocean, yet the contribution from advective settings has just started to be acknowledged. Here we present evidence showing that near-surface heating of sediment in the Guaymas Basin, a young extensional depression, causes mass production and discharge of reactive dissolved organic matter (DOM). In the sediment heated up to ~100 °C, we found unexpectedly low DOC concentrations in the pore waters, reflecting the combined effect of thermal desorption and advective fluid flow. Heating experiments suggested DOC production to be a rapid, abiotic process with the DOC concentration increasing exponentially with temperature. The high proportions of total hydrolyzable amino acids and presence of chemical species affiliated with activated hydrocarbons, carbohydrates and peptides indicate high reactivity of the DOM. Model simulation suggests that at the local scale, near-surface heating of sediment creates short and massive DOC discharge events that elevate the bottom-water DOC concentration. Because of the heterogeneous distribution of high heat flow areas, the expulsion of reactive DOM is spotty at any given time. We conclude that hydrothermal heating of young rift sediments alter deep-ocean budgets of bioavailable DOM, creating organic-rich habitats for benthic life.

  8. Near-surface Heating of Young Rift Sediment Causes Mass Production and Discharge of Reactive Dissolved Organic Matter

    Science.gov (United States)

    Lin, Yu-Shih; Koch, Boris P.; Feseker, Tomas; Ziervogel, Kai; Goldhammer, Tobias; Schmidt, Frauke; Witt, Matthias; Kellermann, Matthias Y.; Zabel, Matthias; Teske, Andreas; Hinrichs, Kai-Uwe

    2017-03-01

    Ocean margin sediments have been considered as important sources of dissolved organic carbon (DOC) to the deep ocean, yet the contribution from advective settings has just started to be acknowledged. Here we present evidence showing that near-surface heating of sediment in the Guaymas Basin, a young extensional depression, causes mass production and discharge of reactive dissolved organic matter (DOM). In the sediment heated up to ~100 °C, we found unexpectedly low DOC concentrations in the pore waters, reflecting the combined effect of thermal desorption and advective fluid flow. Heating experiments suggested DOC production to be a rapid, abiotic process with the DOC concentration increasing exponentially with temperature. The high proportions of total hydrolyzable amino acids and presence of chemical species affiliated with activated hydrocarbons, carbohydrates and peptides indicate high reactivity of the DOM. Model simulation suggests that at the local scale, near-surface heating of sediment creates short and massive DOC discharge events that elevate the bottom-water DOC concentration. Because of the heterogeneous distribution of high heat flow areas, the expulsion of reactive DOM is spotty at any given time. We conclude that hydrothermal heating of young rift sediments alter deep-ocean budgets of bioavailable DOM, creating organic-rich habitats for benthic life.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. FUZZY MODEL FOR TWO-DIMENSIONAL RIVER WATER QUALITY SIMULATION UNDER SUDDEN POLLUTANTS DISCHARGED

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the fuzziness and impreciseness of water environmental system, the fuzzy arithmetic was used to simulate the fuzzy and imprecise relations in modeling river water quality. By defining the parameters of water quality model as symmetrical triangular fuzzy numbers, a two-dimensional fuzzy water quality model for sudden pollutant discharge is established. From the fuzzy model, the pollutant concentrations, corresponding to the specified confidence level of α, can be obtained by means of the α-cut technique and arithmetic operations of triangular fuzzy numbers. Study results reveal that it is feasible in theory and reliable on calculation applying triangular fuzzy numbers to the simulation of river water quality.

  11. Array of surface-confined glow discharges in atmospheric pressure helium: Modes and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Liu, D. X., E-mail: liudingxin@gmail.com, E-mail: mglin5g@gmail.com [Center for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Shaanxi (China); Nie, Q. Y.; Li, H. P. [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Chen, H. L. [Frank Reidy Center for Bioelectrics, Old Dominion University, Norfolk, Virginia 23508 (United States); Kong, M. G., E-mail: liudingxin@gmail.com, E-mail: mglin5g@gmail.com [Center for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Shaanxi (China); Frank Reidy Center for Bioelectrics, Old Dominion University, Norfolk, Virginia 23508 (United States); Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States)

    2014-05-19

    Array of atmospheric pressure surface discharges confined by a two-dimensional hexagon electrode mesh is studied for its discharge modes and temporal evolution so as to a theoretical underpinning to their growing applications in medicine, aerodynamic control, and environmental remediation. Helium plasma surface-confined by one hexagon-shaped rim electrode is shown to evolve from a Townsend mode to a normal and abnormal glow mode, and its evolution develops from the rim electrodes as six individual microdischarges merging in the middle of the hexagon mesh element. Within one hexagon element, microdischarges remain largely static with the mesh electrode being the instantaneous cathode, but move towards the hexagon center when the electrode is the instantaneous anode. On the entire array electrode surface, plasma ignition is found to beat an unspecific hexagon element and then spreads to ignite surrounding hexagon elements. The spreading of microdischarges is in the form of an expanding circle at a speed of about 3 × 10{sup 4} m/s, and their quenching starts in the location of the initial plasma ignition. Plasma modes influence how input electrical power is used to generate and accelerate electrons and as such the reaction chemistry, whereas plasma dynamics are central to understand and control plasma instabilities. The present study provides an important aspect of plasma physics of the atmospheric surface-confined discharge array and a theoretical underpinning to its future technological innovation.

  12. Surface treatment of zinc anodes to improve discharge capacity and suppress hydrogen gas evolution

    Science.gov (United States)

    Cho, Yung-Da; Fey, George Ting-Kuo

    The shape change and redistribution of zinc anode material over the electrode during repeated cycling have been identified as the main factors that can limit the life of alkaline zinc-air batteries. Li 2O-2B 2O 3 (lithium boron oxide, LBO) glass with high Li + conductivity and stability can be coated on the surface of zinc powders. The structures of the surface-treated and pristine zinc powders were characterized by XRD, SEM, TEM, ESCA and BET analyses. XRD patterns of LBO-coated zinc powders revealed that the coating did not affect the crystal structure. TEM images of LBO-coated on the zinc particles were compact with an average passivation layer of about 250 nm. The LBO layer can prevent zinc from coming into direct contact with the KOH electrolyte and minimize the side reactions within the batteries. The 0.1 wt.% LBO-coated zinc anode material provided an initial discharge capacity of 1.70 Ah at 0.5 V, while the pristine zinc electrode delivered only 1.57 Ah. A surface-treated zinc electrode can increase discharge capacity, decrease hydrogen evolution reaction, and reduce self-discharge. The results indicated that surface treatment should be effective for improving the comprehensive properties of anode materials for zinc-air batteries.

  13. Formation of superpower volume discharges and their application for modification of surface of metals

    Science.gov (United States)

    Tarasenko, Victor F.; Shulepov, M. A.

    2008-05-01

    The results of experimental investigations of a volume avalanche discharge initiated by an e-beam (VADIEB) and surface layer of Cu and AlBe foils modifications at the plasma action of VADIEB are given. The volume discharge in the air of atmosphere pressure formed in the gap with the cathode having small curvature radius and with high voltage pulses of nanosecond duration and positive and negative polarity. A supershort avalanche electron beam (SAEB) with formation conditions in gases under atmospheric pressure have been investigated. It is proved that the surface layer is cleared of carbon at foil treatment, and atoms of oxygen penetrate into a foil. It is show that the cleaning depth depends on polarity of voltage pulses. At positive polarity of a copper foil electrode the cleaning is observed at the depth over 50 nm, and atoms of oxygen penetrate at the depth up to 25 nm. Plasma of the superpower volume discharge of nanosecond duration with a specific excitation power of hundreds of MW/cm3, and SAEB, and the discharge plasma radiation of various spectral ranges (including UV, VUV and X-ray) has the influence on the anode. The supershort avalanche electronic beam is generated only at negative polarity of a voltage pulse on an electrode with a small radius of curvature. SAEB influence on modifications of the copper foil surface is registered. VADIEB is easily realized in various gases and at various pressures, and, at gas pressure decrease the density of the beam current in helium can achieve 2 kA/cm2. It allows predicting an opportunity of VADIEB application for metal surface modifications in various technological processes, and for surface dielectric modifications at the certain design of the anode.

  14. High-voltage electrode optimization towards uniform surface treatment by a pulsed volume discharge

    Science.gov (United States)

    Ponomarev, A. V.; Pedos, M. S.; Scherbinin, S. V.; Mamontov, Y. I.; Ponomarev, S. V.

    2015-11-01

    In this study, the shape and material of the high-voltage electrode of an atmospheric pressure plasma generation system were optimised. The research was performed with the goal of achieving maximum uniformity of plasma treatment of the surface of the low-voltage electrode with a diameter of 100 mm. In order to generate low-temperature plasma with the volume of roughly 1 cubic decimetre, a pulsed volume discharge was used initiated with a corona discharge. The uniformity of the plasma in the region of the low-voltage electrode was assessed using a system for measuring the distribution of discharge current density. The system's low-voltage electrode - collector - was a disc of 100 mm in diameter, the conducting surface of which was divided into 64 radially located segments of equal surface area. The current at each segment was registered by a high-speed measuring system controlled by an ARM™-based 32-bit microcontroller. To facilitate the interpretation of results obtained, a computer program was developed to visualise the results. The program provides a 3D image of the current density distribution on the surface of the low-voltage electrode. Based on the results obtained an optimum shape for a high-voltage electrode was determined. Uniformity of the distribution of discharge current density in relation to distance between electrodes was studied. It was proven that the level of non-uniformity of current density distribution depends on the size of the gap between electrodes. Experiments indicated that it is advantageous to use graphite felt VGN-6 (Russian abbreviation) as the material of the high-voltage electrode's emitting surface.

  15. Numerical Study of the Effect of a Power Plant Cooling Water Discharge in the Montevideo Bay

    Directory of Open Access Journals (Sweden)

    Mónica Fossati

    2011-01-01

    Full Text Available The numerical simulation of the water temperature in the Río de la Plata River and Montevideo's Bay was done using the numerical model of finite elements RMA-10 in its 2D vertical integrated mode. Parameters involved in the formulations of thermal exchange with the atmosphere were adjusted using measurements of water temperature in several locations of the water body. After calibrating the model, it was used to represent the operation of a power plant located in Montevideo's Bay. This central takes water from the bay in order to cool its generators and also discharges high-temperature water into the bay. The correct representation of temperatures at the water intake and discharge of the plant reflects that the model is able to represent the operation of the central. Several analysis were made to study the thermal plume, the effects of the water discharge on the water intake of the power plant, and the effect on environmental variables of the study area like currents.

  16. Discharge of surface water from Billund Airport (VB)

    DEFF Research Database (Denmark)

    Wetlesen, Kåre Wessel; Møller, Jens; Bastholm, Lars

    1999-01-01

    It has been found that Billund Airport does not cause any environmental strain on Billund Stream that it can not handle by itself. Thought it has been assessed that in combination with extreme weather the strain can exceed a critical limit. Such situation can cause great damage to the flora...

  17. Anti-Aliased Rendering of Water Surface

    Institute of Scientific and Technical Information of China (English)

    Xue-Ying Qin; Eihachiro Nakamae; Wei Hua; Yasuo Nagai; Qun-Sheng Peng

    2004-01-01

    Water surface is one of the most important components of landscape scenes. When rendering spacious far from the viewpoint. This is because water surface consists of stochastic water waves which are usually modeled by periodic bump mapping. The incident rays on the water surface are actually scattered by the bumped waves,pattern, we estimate this solid angle of reflected rays and trace these rays. An image-based accelerating method is adopted so that the contribution of each reflected ray can be quickly obtained without elaborate intersection calculation. We also demonstrate anti-aliased shadows of sunlight and skylight on the water surface. Both the rendered images and animations show excellent effects on the water surface of a reservoir.

  18. Evaluation of Fatigue Behavior and Surface Characteristics of Aluminum Alloy 2024 T6 After Electric Discharge Machining

    Science.gov (United States)

    Mehmood, Shahid; Shah, Masood; Pasha, Riffat Asim; Sultan, Amir

    2017-09-01

    The effect of electric discharge machining (EDM) on surface quality and consequently on the fatigue performance of Al 2024 T6 is investigated. Five levels of discharge current are analyzed, while all other electrical and nonelectrical parameters are kept constant. At each discharge current level, dog-bone specimens are machined by generating a peripheral notch at the center. The fatigue tests are performed on four-point rotating bending machine at room temperature. For comparison purposes, fatigue tests are also performed on the conventionally machined specimens. Linearized SN curves for 95% failure probability and with four different confidence levels (75, 90, 95 and 99%) are plotted for each discharge current level as well as for conventionally machined specimens. These plots show that the electric discharge machined (EDMed) specimens give inferior fatigue behavior as compared to conventionally machined specimen. Moreover, discharge current inversely affects the fatigue life, and this influence is highly pronounced at lower stresses. The EDMed surfaces are characterized by surface properties that could be responsible for change in fatigue life such as surface morphology, surface roughness, white layer thickness, microhardness and residual stresses. It is found that all these surface properties are affected by changing discharge current level. However, change in fatigue life by discharge current could not be associated independently to any single surface property.

  19. Studying surface water balance in Kurdistan province using GIS

    Directory of Open Access Journals (Sweden)

    Nader Fallah

    2016-06-01

    Full Text Available The study of water exchange in a region or area, which emphasizes the principle of conservation of matter in the water cycle, is called balance. Investigating their balance is the basis for managing the rivers’ water management, the results of which refer to the change rate in surface water supply and can efficiently be used in decision making and optimal use of water resources. The present study was carried out in order to investigate the surface water balance in Kurdistan province using GIS. In so doing, digital topographic maps, soil map of the area, and meteorological data retrieved from the regional stations were used to prepare layers of precipitation, evaporation and infiltration of rainwater into the soil. Discharge-arearegion comparative method was employed to measure the amount of runoff and base flow for each sub-basin in raster form saved per unit area which was subsequently overlapped based on balance equation, and the balance of the region was displayed in a graphical mode. The results indicated that more surface water is wasted in the southeast and central area of the province.

  20. Application of Tank Model for Predicting Water Balance and Flow Discharge Components of Cisadane Upper Catchment

    Directory of Open Access Journals (Sweden)

    Nana Mulyana Arifjaya

    2012-01-01

    Full Text Available The concept of hydrological tank model was well described into four compartments (tanks. The first tank (tank A comprised of one vertical (qA0 and two lateral (qA1 and qA2 water flow components and tank B comprised of one vertical (qB0 and one lateral (qB1 water flow components. Tank C comprised of one vertical (qC0 and one lateral (qC1 water flow components, whereas tank D comprised of one lateral water flow component (qD1.  These vertical water flows would also contribute to the depletion of water flow in the related tanks but would replenish tanks in the deeper layers. It was assumed that at all lateral water flow components would finally accumulate in one stream, summing-up of the lateral water flow, much or less, should be equal to the water discharge (Qo at specified time concerns. Tank A received precipitation (R and evapo-transpiration (ET which was its gradientof (R-ET over time would become the driving force for the changes of water stored in the soil profiles and thosewater flows leaving the soil layer.  Thus tank model could describe th vertical and horizontal water flow withinthe watershed. The research site was Cisadane Upper Catchment, located at Pasir Buncir Village of CaringinSub-District within the Regency of Bogor in West Java Province.  The elevations ranged 512 –2,235 m above sealevel, with a total drainage area of 1,811.5 ha and total length of main stream of 14,340.7 m.  The land cover wasdominated by  forest  with a total of 1,044.6 ha (57.67%,  upland agriculture with a total of 477.96 ha (26.38%,mixed garden with a total of 92.85 ha(5.13% and semitechnical irigated rice field with a total of 196.09 ha (10,8%.  The soil was classified as hydraquent (96.6% and distropept (3.4%.  Based on the calibration of tank model application in the study area, the resulting coefficient of determination (R2 was 0.72 with model efficiency (NSEof= 0.75, thus tank model could well illustrate the water flow distribution of

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    : Martin, Peter; 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

    Agua Caliente Spring, in downtown Palm Springs, California, has been used for recreation and medicinal therapy for hundreds of years and currently (2008) is the source of hot water for the Spa Resort owned by the Agua Caliente Band of the Cahuilla Indians. The Agua Caliente Spring is located about 1,500 feet east of the eastern front of the San Jacinto Mountains on the southeast-sloping alluvial plain of the Coachella Valley. The objectives of this study were to (1) define the geologic structure associated with the Agua Caliente Spring; (2) define the source(s), and possibly the age(s), of water discharged by the spring; (3) ascertain the seasonal and longer-term variability of the natural discharge, water temperature, and chemical characteristics of the spring water; (4) evaluate whether water-level declines in the regional aquifer will influence the temperature of the spring discharge; and, (5) estimate the quantity of spring water that leaks out of the water-collector tank at the spring orifice.

  3. SURFACE WATER QUALITY IN THE RIVER PRUT

    Directory of Open Access Journals (Sweden)

    MIHAELA DUMITRAN

    2011-03-01

    Full Text Available Water is an increasingly important and why it is important to surfacewater quality, which is given by the analysis of physical - chemical, biological andobserving the investigation of water, biota, environments investigation. Analysis ofthe Prut river in terms of biological and physical elements - chemical. Evaluationof ecological and chemical status of water was done according to order of approvalof the standard classification nr.161/2006 surface water to determine the ecologicalstatus of water bodies

  4. Study of Titanizing the Surface of Copper Substrates by the Double Glow Discharge Plasma Surface Alloying Technique

    Institute of Scientific and Technical Information of China (English)

    Zhang Yuefei; Chen Fei; Lü Junxia; Su Yongan; Xu Zhong

    2005-01-01

    This paper discusses a study in which Ti surface alloying has been performed on copper substrates by means of a double glow discharge plasma surface alloying technique. The micro-structure, the phase structure, the micro-hardness and the distribution of Ti concentration of alloying layer were investigated in detail by XRD, SEM and so on. The effect of process parameters on the alloying layer was studied. The experimental results show that a Ti solid solution with the precipitation Cu4Ti alloying layer has been formed on the copper surface. The thickness of the alloying layer is about 120μm and the surface titanium concentration gradually decreases from w (Ti) = 87% to w (Ti) = 4%. The micro-hardness of the alloying layer is between 300 HV ~ 800 HV. Source sputtering, surface absorption, ion bombarding and high temperature diffusion are the major factors that affect the alloying layer.

  5. Microscopic degradation mechanism of polyimide film caused by surface discharge under bipolar continuous square impulse voltage

    Science.gov (United States)

    Luo, Yang; Wu, Guang-Ning; Liu, Ji-Wu; Peng, Jia; Gao, Guo-Qiang; Zhu, Guang-Ya; Wang, Peng; Cao, Kai-Jiang

    2014-02-01

    Polyimide (PI) film is an important type of insulating material used in inverter-fed motors. Partial discharge (PD) under a sequence of high-frequency square impulses is one of the key factors that lead to premature failures in insulation systems of inverter-fed motors. In order to explore the damage mechanism of PI film caused by discharge, an aging system of surface discharge under bipolar continuous square impulse voltage (BCSIV) is designed based on the ASTM 2275 01 standard and the electrical aging tests of PI film samples are performed above the partial discharge inception voltage (PDIV). The chemical bonds of PI polymer chains are analyzed through Fourier transform infrared spectroscopy (FTIR) and the dielectric properties of unaged and aged PI samples are investigated by LCR testers HIOKI 3532-50. Finally, the micro-morphology and micro-structure changes of PI film samples are observed through scanning electron microscopy (SEM). The results show that the physical and chemical effects of discharge cut off the chemical bonds of PI polymer chains. The fractures of ether bond (C—O—C) and imide ring (C—N—C) on the backbone of a PI polymer chain leads to the decrease of molecular weight, which results in the degradation of PI polymers and the generation of new chemical groups and materials, like carboxylic acid, ketone, aldehydes, etc. The variation of microscopic structure of PI polymers can change the orientation ability of polarizable units when the samples are under an AC electric field, which would cause the dielectric constant ɛ to increase and dielectric loss tan δ to decrease. The SEM images show that the degradation path of PI film is initiated from the surface and then gradually extends to the interior with continuous aging. The injection charge could result in the PI macromolecular chain degradation and increase the trap density in the PI polymer bulk.

  6. EFFECT OF DIMPLE GEOMETRIC PARAMETERS OBTAINED ON METAL SURFACE BY ELECTRICAL DISCHARGE ON ITS CUTTING ABILITY

    Directory of Open Access Journals (Sweden)

    M. G. Kiselev

    2016-01-01

    Full Text Available The paper contains an analysis of dimple geometric parameters obtained on wire surface during its in its electrical discharge machining. A photography and description of one of the dimples has been given in the paper. The paper has analyzed a cross-sectional shape of the obtained dimple with due account of the solidified metal flows formed along its edges. The flows in a first approximation can be considered as elements of a cutting wedge. According to cutting theory provisions the paper considers solidified metal flow shapes in a longitudinal section and indicates angles which have been formed by the flows, working planes and edges which can be involved in the cutting process. It has been shown that cutting elements on the dimple surface are arranged symmetrically that makes it possible to carry out cutting process while moving a tool in both directions of reciprocating motion. Parameters of cutting surface influencing on cutting process execution have been specified in the paper. It has been demonstrated that due to changes in energy of electric discharge through voltage or capacity of a power supply storage capacitor it is possible purposefully to influence on the shape and size of metal flows and, respectively, on values of cutting wedge parameters that characterize a tool cutting ability. A conclusion has been made about possibility to obtain the most advantageous values of these parameters while optimizing modes of wire electrical discharge machining.

  7. Impact of reservoirs on river discharge and irrigation water supply during the 20th century

    NARCIS (Netherlands)

    Biemans, H.; Haddeland, I.; Kabat, P.; Ludwig, F.; Hutjes, R.W.A.

    2011-01-01

    This paper presents a quantitative estimation of the impact of reservoirs on discharge and irrigation water supply during the 20th century at global, continental, and river basin scale. Compared to a natural situation the combined effect of reservoir operation and irrigation extractions decreased me

  8. 77 FR 11401 - Marine Sanitation Devices (MSDs): No Discharge Zone (NDZ) for California State Marine Waters

    Science.gov (United States)

    2012-02-27

    ... sewage discharges include solids, nutrients, pathogens, petroleum products, heavy metals, pesticides..., pollute drinking water supplies, harm fish and other aquatic wildlife, and cause damage to coral reefs... protection that should be provided through an NDZ. California's highly varied marine environments support...

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

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, S.-Y.; Byeon, Y.-S.; Yoo, S.; Hong, E. J.; Kim, S. B.; Yoo, S. J.; Ryu, S., E-mail: smryu@nfri.re.kr [Plasma Technology Research Center of National Fusion Research Institute, 37, Dongjangsan-ro, Gunsan-si, Jeollabuk-do, Gunsan 54004 (Korea, Republic of)

    2016-08-15

    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.

  10. Urban surface water pollution problems arising from misconnections.

    Science.gov (United States)

    Revitt, D Michael; Ellis, J Bryan

    2016-05-01

    The impacts of misconnections on the organic and nutrient loadings to surface waters are assessed using specific household appliance data for two urban sub-catchments located in the London metropolitan region and the city of Swansea. Potential loadings of biochemical oxygen demand (BOD), soluble reactive phosphorus (PO4-P) and ammoniacal nitrogen (NH4-N) due to misconnections are calculated for three different scenarios based on the measured daily flows from specific appliances and either measured daily pollutant concentrations or average pollutant concentrations for relevant greywater and black water sources obtained from an extensive review of the literature. Downstream receiving water concentrations, together with the associated uncertainties, are predicted from derived misconnection discharge concentrations and compared to existing freshwater standards for comparable river types. Consideration of dilution ratios indicates that these would need to be of the order of 50-100:1 to maintain high water quality with respect to BOD and NH4-N following typical misconnection discharges but only poor quality for PO4-P is likely to be achievable. The main pollutant loading contributions to misconnections arise from toilets (NH4-N and BOD), kitchen sinks (BOD and PO4-P) washing machines (PO4-P and BOD) and, to a lesser extent, dishwashers (PO4-P). By completely eliminating toilet misconnections and ensuring misconnections from all other appliances do not exceed 2%, the potential pollution problems due to BOD and NH4-N discharges would be alleviated but this would not be the case for PO4-P. In the event of a treatment option being preferred to solve the misconnection problem, it is shown that for an area the size of metropolitan Greater London, a sewage treatment plant with a Population Equivalent value approaching 900,000 would be required to efficiently remove BOD and NH4-N to safely dischargeable levels but such a plant is unlikely to have the capacity to deal

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

    Science.gov (United States)

    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.

  12. Groundwater and surface-water interactions and impacts of human activities in the Hailiutu catchment, northwest China

    Science.gov (United States)

    Yang, Zhi; Zhou, Yangxiao; Wenninger, Jochen; Uhlenbrook, Stefan; Wang, Xusheng; Wan, Li

    2017-02-01

    The interactions between groundwater and surface water have been significantly affected by human activities in the semi-arid Hailiutu catchment, northwest China. Several methods were used to investigate the spatial and temporal interactions between groundwater and surface water. Isotopic and chemical analyses of water samples determined that groundwater discharges to the Hailiutu River, and mass balance equations were employed to estimate groundwater seepage rates along the river using chemical profiles. The hydrograph separation method was used to estimate temporal variations of groundwater discharges to the river. A numerical groundwater model was constructed to simulate groundwater discharges along the river and to analyze effects of water use in the catchment. The simulated seepage rates along the river compare reasonably well with the seepage estimates derived from a chemical profile in 2012. The impacts of human activities (river-water diversion and groundwater abstraction) on the river discharge were analyzed by calculating the differences between the simulated natural groundwater discharge and the measured river discharge. Water use associated with the Hailiutu River increased from 1986 to 1991, reached its highest level from 1992 to 2000, and decreased from 2001 onwards. The reduction of river discharge might have negative impacts on the riparian ecosystem and the water availability for downstream users. The interactions between groundwater and surface water as well as the consequences of human activities should be taken into account when implementing sustainable water resources management in the Hailiutu catchment.

  13. Groundwater and surface-water interactions and impacts of human activities in the Hailiutu catchment, northwest China

    Science.gov (United States)

    Yang, Zhi; Zhou, Yangxiao; Wenninger, Jochen; Uhlenbrook, Stefan; Wang, Xusheng; Wan, Li

    2017-08-01

    The interactions between groundwater and surface water have been significantly affected by human activities in the semi-arid Hailiutu catchment, northwest China. Several methods were used to investigate the spatial and temporal interactions between groundwater and surface water. Isotopic and chemical analyses of water samples determined that groundwater discharges to the Hailiutu River, and mass balance equations were employed to estimate groundwater seepage rates along the river using chemical profiles. The hydrograph separation method was used to estimate temporal variations of groundwater discharges to the river. A numerical groundwater model was constructed to simulate groundwater discharges along the river and to analyze effects of water use in the catchment. The simulated seepage rates along the river compare reasonably well with the seepage estimates derived from a chemical profile in 2012. The impacts of human activities (river-water diversion and groundwater abstraction) on the river discharge were analyzed by calculating the differences between the simulated natural groundwater discharge and the measured river discharge. Water use associated with the Hailiutu River increased from 1986 to 1991, reached its highest level from 1992 to 2000, and decreased from 2001 onwards. The reduction of river discharge might have negative impacts on the riparian ecosystem and the water availability for downstream users. The interactions between groundwater and surface water as well as the consequences of human activities should be taken into account when implementing sustainable water resources management in the Hailiutu catchment.

  14. Low-dielectric layer increases nanosecond electric discharges in distilled water

    Directory of Open Access Journals (Sweden)

    Ahmad Hamdan

    2016-10-01

    Full Text Available Electric discharge in liquids is an emerging field of research, and is involved into various environmental applications (water purification, fuel reforming, nanomaterial synthesis, etc.. Increasing the treatment efficiency with simultaneous decreasing of the energy consumption are the main goals of today’s research. Here we present an experimental study of nanosecond discharge in distilled water covered by a layer of dielectric material. We demonstrate through this paper that the discharge efficiency can be improved by changing the interface position regarding the anode tip. The efficiency increase is due to the increase of the discharge probability as well as the plasma volume. The understanding of the experimental results is brought and strengthened by simulating the electric field distribution, using Comsol Multiphysics software. Because the dielectric permittivity ( ε is discontinuous at the interface, the electric field is enhanced by a factor that depends on the relative value of ε of the two liquids. The present result is very promising in future: opportunities for potential applications as well as fundamental studies for discharges in liquid.

  15. Low-dielectric layer increases nanosecond electric discharges in distilled water

    Science.gov (United States)

    Hamdan, Ahmad; Cha, Min Suk

    2016-10-01

    Electric discharge in liquids is an emerging field of research, and is involved into various environmental applications (water purification, fuel reforming, nanomaterial synthesis, etc.). Increasing the treatment efficiency with simultaneous decreasing of the energy consumption are the main goals of today's research. Here we present an experimental study of nanosecond discharge in distilled water covered by a layer of dielectric material. We demonstrate through this paper that the discharge efficiency can be improved by changing the interface position regarding the anode tip. The efficiency increase is due to the increase of the discharge probability as well as the plasma volume. The understanding of the experimental results is brought and strengthened by simulating the electric field distribution, using Comsol Multiphysics software. Because the dielectric permittivity ( ɛ ) is discontinuous at the interface, the electric field is enhanced by a factor that depends on the relative value of ɛ of the two liquids. The present result is very promising in future: opportunities for potential applications as well as fundamental studies for discharges in liquid.

  16. Low-dielectric layer increases nanosecond electric discharges in distilled water

    KAUST Repository

    Hamdan, Ahmad

    2016-10-24

    Electric discharge in liquids is an emerging field of research, and is involved into various environmental applications (water purification, fuel reforming, nanomaterial synthesis, etc.). Increasing the treatment efficiency with simultaneous decreasing of the energy consumption are the main goals of today’s research. Here we present an experimental study of nanosecond discharge in distilled water covered by a layer of dielectric material. We demonstrate through this paper that the discharge efficiency can be improved by changing the interface position regarding the anode tip. The efficiency increase is due to the increase of the discharge probability as well as the plasma volume. The understanding of the experimental results is brought and strengthened by simulating the electric field distribution, using Comsol Multiphysics software. Because the dielectric permittivity (ε) is discontinuous at the interface, the electric field is enhanced by a factor that depends on the relative value of ε of the two liquids. The present result is very promising in future: opportunities for potential applications as well as fundamental studies for discharges in liquid.

  17. Water-quality, water-level, and discharge data associated with the Mississippi embayment agricultural chemical-transport study, 2006-2008

    Science.gov (United States)

    Dalton, Melinda S.; Rose, Claire E.; Coupe, Richard H.

    2010-01-01

    In 2006, the Agricultural Chemicals: Sources, Transport and Fate study team (Agricultural Chemicals Team, ACT) of the U.S. Geological Survey National Water-Quality Assessment Program began a study in northwestern Mississippi to evaluate the influence of surface-water recharge on the occurrence of agriculturally related nutrients and pesticides in the Mississippi River Valley alluvial aquifer. The ACT study was composed in the Bogue Phalia Basin, an indicator watershed within the National Water-Quality Assessment Program Mississippi Embayment Study Unit and utilized several small, subbasins within the Bogue Phalia to evaluate surface and groundwater interaction and chemical transport in the Basin. Data collected as part of this ACT study include water-quality data from routine and incident-driven water samples evaluated for major ions, nutrients, organic carbon, physical properties, and commonly used pesticides in the area; discharge, gage height and water-level data for surface-water sites, the shallow alluvial aquifer, and hyporheic zone; additionally, agricultural data and detailed management activities were reported by land managers for farms within two subbasins of the Bogue Phalia Basin—Tommie Bayou at Pace, MS, and an unnamed tributary to Clear Creek near Napanee, MS.

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

    Science.gov (United States)

    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

  19. Shaping of steel mold surface of lens array by electrical discharge machining with single rod electrode.

    Science.gov (United States)

    Takino, Hideo; Hosaka, Takahiro

    2014-11-20

    We propose a method for fabricating a lens array mold by electrical discharge machining (EDM). In this method, the tips of rods are machined individually to form a specific surface, and then a number of the machined rods are arranged to construct an electrode for EDM. The repetition of the EDM process using the electrode enables a number of lens elements to be produced on the mold surface. The effectiveness of our proposed method is demonstrated by shaping a lens array mold made of stainless steel with 16 spherical elements, in which the EDM process with a single rod electrode is repeatedly conducted.

  20. Micro Wire Electro Discharge Grinding: Optimization of Material Removal Rate and Surface Roughness

    Science.gov (United States)

    Yeakub Ali, Mohammad; Rahman, Mohamed Abd; Nordin, Rosmarina

    2017-03-01

    This paper presents the analysis and modelling of material removal rate (MRR) and surface roughness (Ra) by micro wire electro discharge grinding (micro-WEDG) with control parameter of gap voltage, feed rate, and spindle speed. The data were analyzed and empirical models are developed. The optimized values of MRR and Ra are 0.051 mm3/min and 0.25 μm respectively with 110 V gap voltage, 38 μm/s feed rate, and 1315 rpm spindle speed. The analysis showed that gap voltage has significant effect on material removal rate while spindle speed has significant effect on surface roughness.

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

    Science.gov (United States)

    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

  2. Results of ground-water, surface-water, and water-chemistry monitoring, Black Mesa area, northeastern Arizona, 1994

    Science.gov (United States)

    Littin, G.R.; Monroe, S.A.

    1995-01-01

    The Black Mesa monitoring program is designed to document long-term effects of ground-water pumping from the N aquifer by industrial and municipal users. The N aquifer is the major source of water in the 5,400-square-mile Black Mesa area, and the ground water occurs under confined and unconfined conditions. Monitoring activities include continuous and periodic measurements of (1) ground-water pumpage from the confined and unconfined areas of the aquifer, (2) ground-water levels in the confined and unconfined areas of the aquifer, (3) surface-water discharge, and (4) chemistry of the ground water and surface water. In 1994, ground-water withdrawals for industrial and municipal use totaled about 7,000 acre-feet, which is an 8-percent increase from the previous year. Pumpage from the confined part of the aquifer increased by about 9 percent to 5,400 acre-feet, and pumpage from the unconfined part of the aquifer increased by about 2 percent to 1,600 acre-feet. Water-level declines in the confined area during 1994 were recorded in 10 of 16 wells, and the median change was a decline of about 2.3 feet as opposed to a decline of 3.3 feet for the previous year. The median change in water levels in the unconfined area was a rise of 0.1 foot in 1994 as opposed to a decline of 0.5 foot in 1993. Measured low-flow discharge along Moenkopi Wash decreased from 3.0 cubic feet per second in 1993 to 2.9 cubic feet per second in 1994. Eleven low-flow measurements were made along Laguna Creek between Tsegi, Arizona, and Chinle Wash to determine the amount of discharge that would occur as seepage from the N aquifer under optimal base-flow conditions. Discharge was 5.6 cubic feet per second near Tsegi and 1.5 cubic feet per second above the confluence with Chinle Wash. Maximum discharge was 5.9 cubic feet per second about 4 miles upstream from Dennehotso. Discharge was measured at three springs. The changes in discharge at Burro and Whisky Springs were small and within the uncertainty of

  3. Thermoluminescence study of the trapped charge at an alumina surface electrode in different dielectric barrier discharge regimes

    Energy Technology Data Exchange (ETDEWEB)

    Ambrico, P F; Ambrico, M; Dilecce, G; De Benedictis, S [Consiglio Nazionale delle Ricerche, Istituto di Metodologie Inorganiche e dei Plasmi UOS Bari-c/o Dipartimento di Chimica, Universita degli Studi di Bari ' Aldo Moro' , via Orabona, 4, 70126 Bari (Italy); Colaianni, A [Dipartimento di Geologia e Geofisica, Universita degli Studi di Bari ' Aldo Moro' , via Orabona, 4, 70126 Bari (Italy); Schiavulli, L, E-mail: paolofrancesco.ambrico@cnr.i [Dipartimento Interateneo di Fisica, Universita degli Studi di Bari ' Aldo Moro' , via Orabona, 4, 70126 Bari (Italy)

    2010-08-18

    In this study, the charge trapping effect in alumina dielectric surfaces has been deeply investigated by means of a dedicated dielectric barrier discharge apparatus in different discharge regimes and gas mixtures. This work further validates our previous findings in the case of air discharges in a filamentary regime. Long lasting charge trapping has been evidenced by ex situ thermoluminescence characterizations of alumina dielectric barrier plates exposed to a plasma. The density of trapped surface charges was found to be higher in the glow discharge with respect to pseudo-glow and filamentary regimes, and for all regimes the minimum trap activation temperature was 390 K and the trap energy was less than or around 1 eV. This implies that in the case of glow discharges a higher reservoir of electrons is present. Also, the effect was found to persist for several days after running the discharge.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. 'Waterstreams': A model for estimation of crop water demand, water supply, salt accumulation and discharge for soilless crops

    NARCIS (Netherlands)

    Voogt, W.; Swinkels, G.L.A.M.; Os, van E.A.

    2012-01-01

    Abstract: Closed growing systems are obligatory for soilless grown greenhouse crops in The Netherlands. It requires water sources of high quality as sodium (Na) accumulation is a potential risk and necessitates frequent discharge, which causes undesirable emission of nutrients and plant protection p

  6. Improving Hydrophobicity of Glass Surface Using Dielectric Barrier Discharge Treatment in Atmospheric Air

    Institute of Scientific and Technical Information of China (English)

    FANG Zhi; QIU Yuchang; WANG Hui; E. KUFFEL

    2007-01-01

    Non-thermal plasmas under atmospheric pressure are of great interest in industrial applications, especially in material surface treatment. In this paper, the treatment of a glass surface for improving hydrophobicity using the non-thermal plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure in ambient air is conducted, and the surface properties of the glass before and after the DBD treatment are studied by using contact angle measurement, surface resistance measurement and wet flashover voltage tests. The effects of the applied voltage and time duration of DBD on the surface modification are studied, and the optimal conditions for the treatment are obtained. It is found that a layer of hydrophobic coating is formed on the glass surface after spraying a thin layer of silicone oil and undergoing the DBD treatment, and the improvement of hydrophobicity depends on DBD voltage and treating time. It seems that there exists an optimum treating time for a certain applied voltage of DBD during the surface treatment. The test results of thermal aging and chemical aging show that the hydrophobic layer has quite stable characteristics. The interaction mechanism between the DBD plasma and the glass surface is discussed. It is concluded that CH3 and large molecule radicals can react with the radicals in the glass surface to replace OH, and the hydrophobicity of the glass surface is improved accordingly.

  7. Manufacturing and characterisation of water repellent surfaces

    DEFF Research Database (Denmark)

    De Grave, Arnaud; Botija, Pablo; Hansen, Hans Nørgaard

    2006-01-01

    design criteria for such surfaces. The problem of adapting this behaviour to artificially roughened surfaces is addressed by providing design criteria for superhydrophobic, water-repellent and self-cleaning surfaces according to the concrete performance desired for them. Different kind of manufacturing...

  8. Pin Hole Discharge Creation in Na2SO4 Water Solutions

    OpenAIRE

    Lucie Hlavatá; Rodica Serbanescu; Lenka Hlochová; Zdenka Kozáková; František Krčma

    2013-01-01

    This work deals with the diaphragm discharge generated in water solutions containing Na2SO4 as a supporting electrolyte. The solution conductivity was varied in the range of 270 ÷ 750 µScm-1. The batch plasma reactor with volume of 100 ml was divided into two electrode spaces by the Shapal-MTM ceramics dielectric barrier with a pin-hole (diameter of 0.6 mm). Three variable barrier thicknesses (0.3; 0.7 and 1.5 mm) and non-pulsed DC voltage up to 2 kV were used for the discharge creation. Each...

  9. Variables of state and charateristics for isentropic discharge phenomena of water, starting with saturation

    Energy Technology Data Exchange (ETDEWEB)

    Baudisch, H.

    1968-03-15

    The tables presented in this report contain the thermodynamic values of isentropic change of state for water in the two-phase region starting from the saturation line down to 0.01 at. The variables have been computed in the pressure range from 5-100 at. in equal pressure intervals of 5 at. and in the range from 100-170 at. in intervals of 10 at. Assuming a one-dimensional flow and a known saturation pressure, the dimensions of a discharge nozzle may be determined by interpolation of the calculated values for an isentropic discharge. 4 figs., 29 tabs., 23 refs.

  10. Surface Water Quality Monitoring Sites

    Data.gov (United States)

    Minnesota Department of Natural Resources — The MN Department of Agriculture (MDA) is charged with periodically collecting and analyzing water samples from selected locations throughout the state to determine...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Characteristics of ac capillary discharge produced in electrically conductive water solution

    Science.gov (United States)

    DeBaerdemaeker, F.; Simek, M.; Schmidt, J.; Leys, C.

    2007-05-01

    Basic electrical, optical and calorimetric characteristics of an ac (50 Hz) driven capillary discharge produced in a water solution were studied for initial water solution conductivity in the range 50-1000 µS cm-1. Typical current and voltage waveforms and emission intensities produced by several electronically excited species were recorded with high time resolution. The evolution of the electrical current, power and capillary resistance was inspected during positive ac half-cycle for various operational regimes. A fast relaxation of the discharge following a breakdown event was observed. Optical measurements indicate that radiative species are mostly generated during the first few hundreds of nanoseconds of plasma generation and that the average duration of plasma emission induced by a discharge pulse is of the order of a few microseconds. Results of calorimetric measurements are in good agreement with average electrical measurements and support the assumption that the discharge is a constant source of heat delivered to the liquid. Assuming that only a fraction of the heat released inside the capillary can be transported by conduction through the capillary wall and via its orifices, the processes of bubble formation, expulsion and re-filling the capillary with 'fresh' water must play a key role in maintaining a thermal balance during long-time steady-state operation of the device. Furthermore, a simplified numerical model and a first order energy deposition calculation prove the plausibility of the bubble breakdown mechanism.

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

    Science.gov (United States)

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

    2016-09-01

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

  14. Stress response of Escherichia coli induced by surface streamer discharge in humid air

    Science.gov (United States)

    Doležalová, Eva; Prukner, Václav; Lukeš, Petr; Šimek, Milan

    2016-02-01

    Inactivation of Escherichia coli by means of surface streamer discharge has been investigated to obtain new insights into the key mechanisms involved, with a particular emphasis placed on the microbial response to plasma-induced stress. The surface streamer discharge was produced in coplanar dielectric barrier discharge electrode geometry, and was driven by an amplitude-modulated ac high voltage in humid synthetic air at atmospheric pressure. The response to plasma-induced stress was evaluated by using conventional cultivation, sublethal injury and resazurin assay and the LIVE/DEAD® BacLight™ Bacterial Viability kit. Compared to conventional cultivation, the LIVE/DEAD® test labels bacteria with damaged membranes, while resazurin assay tracks their metabolic activity. Our results clearly demonstrate that the treated bacteria partly lost their ability to grow properly, i.e. they became injured and culturable, or even viable but nonculturable (VBNC). The ability to develop colonies could have been lost due to damage of the bacterial membrane. Damage of the membranes was mainly caused by the lipid peroxidation, evidencing the key role of oxygen reactive species, in particular ozone. We conclude that the conventional cultivation method overestimates the decontamination efficiency of various plasma sources, and must therefore be complemented by alternative techniques capable of resolving viable but nonculturable bacteria.

  15. Surface depression with double-angle geometry during the discharge of grains from a silo

    Science.gov (United States)

    Pacheco-Vázquez, F.; Ramos-Reyes, A. Y.; Hidalgo-Caballero, S.

    2017-08-01

    When rough grains in loose packing conditions are discharged from a silo, a conical depression with a single slope is formed at the surface. We observed that the increase of volume fraction generates a more complex depression, characterized by two angles of discharge: one at the bottom similar to the angle of repose and a considerably larger upper angle. The change in slope appears at the boundary between a dense stagnant region at the periphery and the central flowing channel formed over the aperture. Since the material in the latter zone is always fluidized, the flow rate is unaffected by the initial packing of the bed. On the other hand, the contrast between both angles is markedly smaller when smooth particles of the same size and density are used, which reveals that high packing fraction and friction must combine to produce the observed geometry. Our results show that the surface profile helps to identify by simple visual inspection the packing conditions of a granular bed, being useful to prevent undesirable collapses during silo discharge in industry.

  16. Atmospheric pressure argon surface discharges propagated in long tubes: physical characterization and application to bio-decontamination

    Science.gov (United States)

    Kovalova, Zuzana; Leroy, Magali; Jacobs, Carolyn; Kirkpatrick, Michael J.; Machala, Zdenko; Lopes, Filipa; Laux, Christophe O.; DuBow, Michael S.; Odic, Emmanuel

    2015-11-01

    Pulsed corona discharges propagated in argon (or in argon with added water vapor) at atmospheric pressure on the interior surface of a 49 cm long quartz tube were investigated for the application of surface bio-decontamination. H2O molecule dissociation in the argon plasma generated reactive species (i.e. OH in ground and excited states) and UV emission, which both directly affected bacterial cells. In order to facilitate the evaluation of the contribution of UV radiation, a DNA damage repair defective bacterial strain, Escherichia coli DH-1, was used. Discharge characteristics, including propagation velocity and plasma temperature, were measured. Up to ~5.5 and ~5 log10 reductions were observed for E. coli DH-1 bacteria (from 106 initial load) exposed 2 cm and 44 cm away from the charged electrode, respectively, for a 20 min plasma treatment. The factors contributing to the observed bactericidal effect include desiccation, reactive oxygen species (OH) plus H2O2 accumulation in the liquid phase, and UV-B (and possibly VUV) emission in dry argon. The steady state temperature measured on the quartz tube wall did not exceeded 29 °C the contribution of heating, along with that of H2O2 accumulation, was estimated to be low. The effect of UV-B emission alone or in combination with the other stress factors of the plasma process was examined for different operating conditions.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Masayuki [Department of Chemical and Environmental Engineering, Gunma University 1-5-1 Tenjin, Kiryu, Gunma 376-8515 (Japan)], E-mail: mxsato@cee.gunma-u.ac.jp

    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.

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

    Institute of Scientific and Technical Information of China (English)

    贺元吉; 董丽敏; 杨嘉祥

    2004-01-01

    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.

  19. Inactivation of Bacteria in Oil Field Injected Water by a Pulsed Plasma Discharge Process

    Science.gov (United States)

    Xin, Qing; Li, Zhongjian; Lei, Lecheng; Yang, Bin

    2016-09-01

    Pulsed plasma discharge was employed to inactivate bacteria in the injection water for an oil field. The effects of water conductivity and initial concentration of bacteria on elimination efficiency were investigated in the batch and continuous flow modes. It was demonstrated that Fe2+ contained in injection water could enhance the elimination efficiency greatly. The addition of reducing agent glutathione (GSH) indicated that active radicals generated by pulsed plasma discharges played an important role in the inactivation of bacteria. Moreover, it was found that the microbial inactivation process for both batch and continuous flow mode well fitted the model based on the Weibull's survival function. supported by Zhejiang Province Welfare Technology Applied Research Project of China (No. 2014C31137), National Natural Science Foundation of China (Nos. 21436007 and U1462201), and the Fundamental Research Funds for the Central Universities of China (No. 2015QNA4032)

  20. Discharge of Oilfield-Produced Water in Nueces Bay, Texas: A Case Study

    Science.gov (United States)

    D'Unger, Claude; Chapman, Duane; Carr, R. Scott

    1996-01-01

    During oil and gas production, water is often extracted from geological formations along with the hydrocarbons. These “produced waters” have been discharged to Nueces Bay since the turn of the century. These effluents were found to be highly toxic, and sediments in the vicinity of the discharges were also toxic. We developed a map of wells and produced-water discharge sites in the vicinity of Nueces Bay and identified numerous unplugged wells suitable for conversion to produced water disposal wells. An economic analysis of conversion to subterranean injection of produced water indicates that most of the wells currently in production could pay out the cost of conversion to injection in one to three years. The use of one injection well for two or more water-producing wells could yield greater savings. Wells that could not support the cost of injection are small producers, and their loss would not constitute a major loss of jobs or dollars to the area. This study could serve as a useful model for evaluating the economic feasibility of conversion to injection in other areas of Texas and Louisiana.

  1. Quality of surface water in Missouri, water year 2012

    Science.gov (United States)

    Barr, Miya N.

    2014-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams and springs throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2012 water year (October 1, 2011, through September 30, 2012), data were collected at 81 stations—73 Ambient Water-Quality Monitoring Network stations, 6 alternate Ambient Water-Quality Monitoring Network stations, and 2 U.S. Geological Survey National Stream Quality Accounting Network stations. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite as nitrogen, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 78 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  2. Quality of surface water in Missouri, water year 2013

    Science.gov (United States)

    Barr, Miya N.; Schneider, Rachel E.

    2014-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams and springs throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2013 water year (October 1, 2012, through September 30, 2013), data were collected at 79 stations—73 Ambient Water-Quality Monitoring Network stations, 4 alternate Ambient Water-Quality Monitoring Network stations, and 2 U.S. Geological Survey National Stream Quality Accounting Network stations. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, Escherichia coli bacteria, fecal coliform bacteria, dissolved nitrate plus nitrite as nitrogen, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 76 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  3. Surface water hydrology and the Greenland Ice Sheet

    Science.gov (United States)

    Smith, L. C.; Yang, K.; Pitcher, L. H.; Overstreet, B. T.; Chu, V. W.; Rennermalm, A. K.; Cooper, M. G.; Gleason, C. J.; Ryan, J.; Hubbard, A.; Tedesco, M.; Behar, A.

    2016-12-01

    Mass loss from the Greenland Ice Sheet now exceeds 260 Gt/year, raising global sea level by >0.7 mm annually. Approximately two-thirds of this total mass loss is now driven by negative ice sheet surface mass balance (SMB), attributed mainly to production and runoff of meltwater from the ice sheet surface. This new dominance of runoff as a driver of GrIS total mass loss will likely persist owing to anticipated further increases in surface melting, reduced meltwater storage in firn, and the waning importance of dynamical mass losses (ice calving) as the ice sheets retreat from their marine-terminating margins. It also creates the need and opportunity for integrative research pairing traditional surface water hydrology approaches with glaciology. As one example, we present a way to measure supraglacial "runoff" (i.e. specific discharge) at the supraglacial catchment scale ( 101-102 km2), using in situ measurements of supraglacial river discharge and high-resolution satellite/drone mapping of upstream catchment area. This approach, which is standard in terrestrial hydrology but novel for ice sheet science, enables independent verification and improvement of modeled SMB runoff estimates used to project sea level rise. Furthermore, because current SMB models do not consider the role of fluvial watershed processes operating on the ice surface, inclusion of even a simple surface routing model materially improves simulations of runoff delivered to moulins, the critical pathways for meltwater entry into the ice sheet. Incorporating principles of surface water hydrology and fluvial geomorphology and into glaciological models will thus aid estimates of Greenland meltwater runoff to the global ocean as well as connections to subglacial hydrology and ice sheet dynamics.

  4. A prototype of radar-drone system for measuring the surface flow velocity at river sites and discharge estimation

    Science.gov (United States)

    Moramarco, Tommaso; Alimenti, Federico; Zucco, Graziano; Barbetta, Silvia; Tarpanelli, Angelica; Brocca, Luca; Mezzanotte, Paolo; Rosselli, Luca; Orecchini, Giulia; Virili, Marco; Valigi, Paolo; Ciarfuglia, Thomas; Pagnottelli, Stefano

    2015-04-01

    Discharge estimation at a river site depends on local hydraulic conditions identified by recording water levels. In fact, stage monitoring is straightforward and relatively inexpensive compared with the cost necessary to carry out flow velocity measurements which are, however, limited to low flows and constrained by the accessibility of the site. In this context the mean flow velocity is hard to estimate for high flow, affecting de-facto the reliability of discharge assessment for extreme events. On the other hand, the surface flow velocity can be easily monitored by using radar sensors allowing to achieve a good estimate of discharge by exploiting the entropy theory applied to rivers hydraulic (Chiu,1987). Recently, a growing interest towards the use of Unmanned Aerial Vehicle (UVA), henceforth drone, for topographic applications is observed and considering their capability drones may be of a considerable interest for the hydrological monitoring and in particular for streamflow measurements. With this aim, for the first time, a miniaturized Doppler radar sensor, operating at 24 GHz, will be mounted on a drone to measure the surface flow velocity in rivers. The sensor is constituted by a single-board circuit (i.e. is a fully planar circuits - no waveguides) with the antenna on one side and the front-end electronic on the other side (Alimenti et al., 2007). The antenna has a half-power beam width of less than 10 degrees in the elevation plane and a gain of 13 dBi. The radar is equipped with a monolithic oscillator and transmits a power of about 4 mW at 24 GHz. The sensor is mounted with an inclination of 45 degrees with respect to the drone flying plane and such an angle is considered in recovering the surface speed of the water. The drone is a quadricopter that has more than 30 min, flying time before recharging the battery. Furthermore its flying plan can be scheduled with a suitable software and is executed thanks to the on-board sensors (GPS, accelerometers

  5. Study on ozone treatment of soil for agricultural application of surface dielectric barrier discharge

    Science.gov (United States)

    Nagatomo, Takuya; Abiru, Tomoya; Mitsugi, Fumiaki; Ebihara, Kenji; Nagahama, Kazuhiro

    2016-01-01

    Recently, application of plasma technologies to the agricultural field has attracted much interest because residual pesticides and excessive nitrogen oxides contained in plants, soil, and groundwater have become a serious issue worldwide. Since almost all of the atmospheric discharge plasma generates ozone, the effects of ozone are among the key factors for their agricultural applications. We have proposed the use of ozone generated using surface barrier discharge plasma for soil disinfection or sterilization. In this work, the ozone consumption coefficient and diffusion coefficient in soil were measured by the ultraviolet absorption method. The pH(H2O) and amount of nitrogen nutrient in soil after ozone diffusion treatment were studied and plant growth was observed simultaneously. The effect of ozone treatment on the amount of DNA in soil was also investigated and compared with that determined from the obtained ozone consumption coefficient.

  6. PRO-GRADE: GIS toolkits for ground water recharge and discharge estimation.

    Science.gov (United States)

    Lin, Yu-Feng; Wang, Jihua; Valocchi, Albert J

    2009-01-01

    PRO-GRADE is an ESRI ArcGIS 9.2 plug-in package that consists of two separate toolkits: (1) the pattern recognition organizer for geographic information system (PRO-GIS) and (2) the ground water recharge and discharge estimator for GIS (GRADE-GIS). PRO-GIS is a collection of several existing image-processing algorithms into one user interface to offer the flexibility to extract spatial patterns according to the user's needs. GRADE-GIS is a ground water recharge and discharge estimation interface using a mass balance method that requires only hydraulic conductivity, water table, and bedrock elevation data for simulating two-dimensional steady-state unconfined aquifers. PRO-GRADE was developed to assist ongoing assessments of the water resources in Illinois and Wisconsin, and is being used to assist several ground water resource studies in several locations in the United States. The advantage of using PRO-GRADE is to enable fast production of initial recharge and discharge maps that can be further enhanced by using a follow-up ground water flow model with parameter estimation codes. PRO-GRADE leverages ArcGIS to provide a computer-assisted framework to support expert judgment in order to efficiently select alternative recharge and discharge maps that can be used as (1) guidelines for field study planning and decision making; (2) initial conditions for numerical simulation; and (3) screening for alternative model selection and prediction/parameter uncertainty evaluation. In addition, PRO-GRADE allows for more easy and rapid correlation of those maps with other hydrologically relevant geospatial data.

  7. Remote monitoring of volumetric discharge employing bathymetry determined from surface turbulence metrics

    Science.gov (United States)

    Johnson, E. D.; Cowen, E. A.

    2016-03-01

    Current methods employed by the United States Geological Survey (USGS) to measure river discharge are manpower intensive, expensive, and during high flow events require field personnel to work in dangerous conditions. Indirect methods of estimating river discharge, which involve the use of extrapolated rating curves, can result in gross error during high flow conditions due to extrapolation error and/or bathymetric change. Our goal is to develop a remote method of monitoring volumetric discharge that reduces costs at the same or improved accuracy compared with current methods, while minimizing risk to field technicians. We report the results of Large-Scale Particle Image Velocimetry (LSPIV) and Acoustic Doppler Velocimetry (ADV) measurements conducted in a wide-open channel under a range of flow conditions, i.e., channel aspect ratio (B/H = 6.6-31.9), Reynolds number (ReH = 4,950-73,800), and Froude number (Fr = 0.04-0.46). Experiments were carried out for two different channel cross sections (rectangular and asymmetric compound) and two bathymetric roughness conditions (smooth glass and rough gravel bed). The results show that the mean surface velocity normalized by the depth-averaged velocity (the velocity index) decreases with increasing δ*/H, where δ* is the boundary layer displacement thickness and that the integral length scales, L11,1 and L22,1, calculated on the free-surface vary predictably with the local flow depth. Remote determination of local depth-averaged velocity and flow depth over a channel cross section yields an estimate of volumetric discharge.

  8. Etching Processes of Polytetrafluoroethylene Surfaces Exposed to He and He-O2 Atmospheric Post-discharges

    CERN Document Server

    Hubert, J; Vandencasteele, Nicolas; Desbief, Simon; Lazzaroni, Roberto; Reniers, F

    2016-01-01

    A comparative study of polytetrafluoroethylene (PTFE) surfaces treated by the post-discharge of He and He-O2 plasmas at atmospheric pressure is presented. The characterization of treated PTFE surfaces and the species involved in the surface modification are related. In pure He plasmas, no significant change of the surface has been observed by X-ray photoelectron spectroscopy (XPS), dynamic water contact angles (dWCA) and atomic force microscopy (AFM), in spite of important mass losses recorded. According to these observations, a layer-by-layer physical etching without any preferential orientation is proposed, where the highly energetic helium metastables are the main species responsible for the scission of --(CF2)n-- chains. In He--O 2 plasmas, as the density of helium metastables decreases as a function of the oxygen flow rate, the treatment leads to fewer species ejected from the PTFE surfaces (in agreement with mass loss measurements and the detection of fluorinated species onto aluminum foil). However, th...

  9. Experimental investigations on characteristics of stable water electrospray in air without discharge

    Science.gov (United States)

    Park, Inyong; Hong, Won Seok; Kim, Sang Bok; Kim, Sang Soo

    2017-06-01

    An experimental study was conducted to resolve previous conflicting results on water electrospray in air at atmospheric pressure. Using a small flow rate relative to that used in previous studies and a small nonmetallic nozzle, we observed stable electrospray of water in air without discharge and distinguished three distinct operating regimes for applied voltage and flow rate. The well-known cone-jet mode was observed and the general scaling law of the generated droplet size in the cone-jet mode was confirmed by direct visualization of the meniscus, jet, and generated droplets. We also observed and analyzed whipping motion in the electrified water jet.

  10. Dynamic corona characteristics of water droplets on charged conductor surface

    Science.gov (United States)

    Xu, Pengfei; Zhang, Bo; Wang, Zezhong; Chen, Shuiming; He, Jinliang

    2017-03-01

    The formation of the Taylor cone of a water droplet on the surface of the conductor in a line-ground electrode system is captured using a high-speed camera, while the corona current is synchronously measured using a current measurement system. Repeated Taylor cone deformation is observed, yielding regular groupings of corona current pulses. The underlying mechanism of this deformation is studied and the correlation between corona discharge characteristics and cone deformation is investigated. Depending on the applied voltage and rate of water supply, the Taylor cone may be stable or unstable and has a significant influence on the characteristics of the corona currents. If the rate of water supply is large enough, the Taylor cone tends to be unstable and generates corona-current pulses of numerous induced current pulses with low amplitudes. In consequence, this difference suggests that large rainfall results in simultaneously lower radio interference and higher corona loss.

  11. The interplay of snow, surface water, and groundwater reservoirs for integrated water resources management

    Science.gov (United States)

    Rajagopal, S.; Huntington, J.

    2015-12-01

    Changes in climate, growth in population and economy have increased the reliance on groundwater to augment supplies of surface water across the world, and especially the Western United States. Martis Valley, a high altitude, snow dominated watershed in the Sierra Nevada, California has both surface (river/reservoir) and groundwater resources that are utilized to meet demands within the valley. The recent drought and changing precipitation type (less snow, more rain) has stressed the regional surface water supply and has increased the reliance on groundwater pumping. The objective of this paper is to quantify how changes in climate and depletion of snow storage result in decreased groundwater recharge and increased groundwater use, and to assess if increased surface water storage can mitigate impacts to groundwater under historic and future climate conditions. These objectives require knowledge on the spatiotemporal distribution of groundwater recharge, discharge, and surface and groundwater interactions. We use a high resolution, physically-based integrated surface and groundwater model, GSFLOW, to identify key mechanisms that explain recent hydrologic changes in the region. The model was calibrated using a multi-criteria approach to various historical observed hydrologic fluxes (streamflow and groundwater pumping) and states (lake stage, groundwater head, snow cover area). Observations show that while groundwater use in the basin has increased significantly since the 1980's, it still remains a relatively minor component of annual consumptive water use. Model simulations suggest that changes from snow to rain will lead to increases in Hortonian and Dunnian runoff, and decreases in groundwater recharge and discharge to streams, which could have a greater impact on groundwater resources than increased pumping. These findings highlight the necessity of an integrated approach for evaluating natural and anthropogenic impacts on surface and groundwater resources.

  12. Index of surface-water stations in Texas, January 1988

    Science.gov (United States)

    Rawson, Jack; Carrillo, E.R.; Buckner, H.D.

    1988-01-01

    As of January 1, 1988, the surface-water data-collection network in Texas included 368 continuous streamflow, 12 continuous or daily reservoir-content, 38 gage height, 15 crest-stage partia 1-record, 4 periodic discharge through range, 32 floodhydrocjraph partial-record, 9 flood-profile partial-record, 36 low-flow partial-record 45 daily chemical-quality, 19 continuous-recording water-quality, 83 periodic biological, 19 lake surveys, 160 periodic organic and (or) nutrient, 3 periodic insecticide, 33 periodic pesticide, 20 automatic sampler, 137 periodic minor elements, 125 periodic chemical-quality, 74 periodic physica1-organic, 24 continuous-recording three- or four-parameter water-quality, 34 periodic sediment, 21 continuous-recording temperature, and 30 national stream-quality accounting network stations. Plate 1 shows the location of surface-water streamflow or reservoir-content and chemicalquality or sediment stations in Texas. Plate 2 shows the location of partial-record surface-water stations.

  13. Baseline studies and evaluation of effects of surface discharge of deep-sea mining - INDEX area

    Digital Repository Service at National Institute of Oceanography (India)

    DeSousa, S.N.; Sardessai, S.

    Hydrochemical properties of the water column were measured at the Indian Experiment (INDEX) site in the Central Indian Ocean Basin, as a part of baseline studies for the environmental impact assessment of benthic disturbance. The surface mixed layer...

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

    Science.gov (United States)

    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.

  15. Fluorescence (TALIF) measurement of atomic hydrogen concentration in a coplanar surface dielectric barrier discharge

    Science.gov (United States)

    Mrkvičková, M.; Ráheľ, J.; Dvořák, P.; Trunec, D.; Morávek, T.

    2016-10-01

    Spatially and temporally resolved measurements of atomic hydrogen concentration above the dielectric of coplanar barrier discharge are presented for atmospheric pressure in 2.2% H2/Ar. The measurements were carried out in the afterglow phase by means of two-photon absorption laser-induced fluorescence (TALIF). The difficulties of employing the TALIF technique in close proximity to the dielectric surface wall were successfully addressed by taking measurements on a suitable convexly curved dielectric barrier, and by proper mathematical treatment of parasitic signals from laser-surface interactions. It was found that the maximum atomic hydrogen concentration is situated closest to the dielectric wall from which it gradually decays. The maximum absolute concentration was more than 1022 m-3. In the afterglow phase, the concentration of atomic hydrogen above the dielectric surface stays constant for a considerable time (10 μs-1 ms), with longer times for areas situated farther from the dielectric surface. The existence of such a temporal plateau was explained by the presented 1D model: the recombination losses of atomic hydrogen farther from the dielectric surface are compensated by the diffusion of atomic hydrogen from regions close to the dielectric surface. The fact that a temporal plateau exists even closest to the dielectric surface suggests that the dielectric surface acts as a source of atomic hydrogen in the afterglow phase.

  16. Surface Water Treatment Workshop Manual.

    Science.gov (United States)

    Ontario Ministry of the Environment, Toronto.

    This manual was developed for use at workshops designed to increase the knowledge of experienced water treatment plant operators. Each of the fourteen lessons in this document has clearly stated behavioral objectives to tell the trainee what he should know or do after completing that topic. Areas covered in this manual include: basic water…

  17. Evidence for water structuring forces between surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, Christopher B [ORNL; Rau, Dr. Donald [National Institutes of Health

    2011-01-01

    Structured water on apposing surfaces can generate significant energies due to reorganization and displacement as the surfaces encounter each other. Force measurements on a multitude of biological structures using the osmotic stress technique have elucidated commonalities that point toward an underlying hydration force. In this review, the forces of two contrasting systems are considered in detail: highly charged DNA and nonpolar, uncharged hydroxypropyl cellulose. Conditions for both net repulsion and attraction, along with the measured exclusion of chemically different solutes from these macromolecular surfaces, are explored and demonstrate features consistent with a hydration force origin. Specifically, the observed interaction forces can be reduced to the effects of perturbing structured surface water.

  18. Quantifying the impacts of climate and human activities on water and sediment discharge in a karst region of southwest China

    Science.gov (United States)

    Li, Zhenwei; Xu, Xianli; Yu, Bofu; Xu, Chaohao; Liu, Meixian; Wang, Kelin

    2016-11-01

    Quantifying the impacts of climate and human activities on water and sediment discharge has become a central topic in climate and hydrologic research. This issue, however, has so far received little attention in karst regions around the world. Seven karst catchments located in southwest China were chosen to explore water and sediment discharge responses to different driving factors during the period from the 1950s to 2011. The non-parametric Mann-Kendall test was used to detect both the trends and abrupt changes in water and sediment discharge. The double mass curve method was used to quantify the effects of climate and human activities on water and sediment discharge. Results indicated that the annual water discharge showed a decreasing trend in all catchments (-0.21 to -3.68 × 108 m3 yr-1), and the sediment discharge exhibited a significant decreasing trend (-7 to -101 × 104 t yr-1) for six out of the seven catchments. A rapid decline (abrupt change) in sediment discharge occurred since 2000 for all except Liujiang catchment where the sediment discharge has a slight increase since 1983 as no large dams were constructed in this catchment. Specifically, the magnitude of reduction in sediment discharge (%) significantly increases with the extent of flow regulation as measured by the ratio of the area upstream the dam to the total catchment area for the seven catchments (R2 = 0.98, P China.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

    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 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.

  1. Assessment of Wastewater Discharge Impact from a Sewage Treatment Plant on Lagoon Water, Lagos, Nigeria

    Directory of Open Access Journals (Sweden)

    Ezechiel Longe

    2010-05-01

    Full Text Available The aim of this study was to assess the wastewater discharge impact from the University of Lagos campus treatment plant on the lagoon system . In order to achieve this objective water samples were collected from nine sites and analyzed for different wastewater quality variables. The field survey was carried out between July and November in order to capture both the wet and dry seasons. Average removal efficiencies of measured parameters from treated effluents are 26% for Total Dissolved Solids (TDS, 73% for Biological Oxygen Demand (BOD, 65.8% for Chemical Oxygen Demand (COD and 72% for Total Nitrogen (Total N for the wet season campaign. During the dry season average rem oval efficiencies of measured parameters are 54% for TDS, 54% for BOD, 39% for COD and 42% for Total N. These values are lower than values obtained for the wet season except for TDS. Most parameters in effluents exceeded the National Environmental Protection Regulations, Effluent Limitation standards for discharge into river bodies. Average concentrations of TDS, BOD and COD in lagoon water show higher concentrations than in the treated effluent and are above the regulatory requirements. The research recommends further study on the possible influence of water dynamics and sampling methods on water quality of the lagoon. The overall results from this research conclude that the lagoon is being polluted by effluents discharge from the university treatment plant thereby exposing the health of local residents who use it for recreation and for food production purposes.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Effects of lowering nitrogen and phosphorus surpluses in agriculture on the quality of groundwater and surface water in the Netherlands

    NARCIS (Netherlands)

    Oenema, O.; Liere, van L.; Schoumans, O.F.

    2005-01-01

    The ecological status of many surface waters in the Netherlands (NL) is poor, due to relatively high discharges of N and P from agriculture, industry and wastewater treatment plants. Agriculture is suggested to be a major source, as discharges from industry and wastewater treatment plants have sharp

  4. Quality of surface water in Missouri, water year 2014

    Science.gov (United States)

    Barr, Miya N.

    2015-12-18

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams and springs throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2014 water year (October 1, 2013, through September 30, 2014), data were collected at 74 stations—72 Ambient Water-Quality Monitoring Network stations and 2 U.S. Geological Survey National Stream Quality Assessment Network stations. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, Escherichia coli bacteria, fecal coliform bacteria, dissolved nitrate plus nitrite as nitrogen, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 71 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  5. Quality of surface water in Missouri, water year 2010

    Science.gov (United States)

    Barr, Miya N.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designs and operates a series of monitoring stations on streams throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2010 water year (October 1, 2009 through September 30, 2010), data were collected at 75 stations-72 Ambient Water-Quality Monitoring Network stations, 2 U.S. Geological Survey National Stream Quality Accounting Network stations, and 1 spring sampled in cooperation with the U.S. Forest Service. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 72 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  6. Quality of surface water in Missouri, water year 2009

    Science.gov (United States)

    Barr, Miya N.

    2010-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designs and operates a series of monitoring stations on streams throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2009 water year (October 1, 2008, through September 30, 2009), data were collected at 75 stations-69 Ambient Water-Quality Monitoring Network stations, 2 U.S. Geological Survey National Stream Quality Accounting Network stations, 1 spring sampled in cooperation with the U.S. Forest Service, and 3 stations sampled in cooperation with the Elk River Watershed Improvement Association. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 72 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and seven-day low flow is presented.

  7. Quality of surface water in Missouri, water year 2011

    Science.gov (United States)

    Barr, Miya N.

    2012-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2011 water year (October 1, 2010, through September 30, 2011), data were collected at 75 stations—72 Ambient Water-Quality Monitoring Network stations, 2 U.S. Geological Survey National Stream Quality Accounting Network stations, and 1 spring sampled in cooperation with the U.S. Forest Service. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 72 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  8. Surface alloying of Cu with Ti by double glow discharge process

    Institute of Scientific and Technical Information of China (English)

    袁庆龙; 池成忠; 苏永安; 徐重; 唐宾

    2004-01-01

    The surface of pure copper alloyed with Ti using double glow discharge process was investigated. The morphology, structure and forming mechanism of the Cu-Ti alloying layer were analyzed. The microhardness and wear resistance of the Cu-Ti alloying layer were measured, and compared with those of pure copper. The results indicate that the surface of copper activated by Ar and Ti ions bombardment is favorable to absorption and diffusion of Ti element. In current experimental temperature, as the Ti content increases, the liquid phase occurs between the deposited layer and diffused layer, which makes the Ti ions and atoms easy to dissolve and the thickness of Cu-Ti alloying layer increase rapidly. After cooling, the structure of the alloying layer is composed of CuTi, Cu4 Ti and Cu(Ti) solid solution. The solid solution strengthening and precipitation strengthening effects of Ti result in high surface hardness and wear resistance.

  9. Total control-based unified allocation model for allowable basin water withdrawal and sewage discharge

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper,a new model with a total amount control target of allowable water withdrawal based on initial water right is built for the implementation of initial water right allocation scheme as well as unified allocation for allowable water withdrawal and sewage discharge.The model couples the water allocation simulation model and the computational model of permissible pol-lution bearing capacity.In view of the model complexity,a new technology which synthesizes system simulation,iterative reservoir turns and intelligent computation is proposed to improve the operability of allocation scheme and computational efficiency.Taking the Beijiang River Basin in the Pearl River Basin as an example,the study explains the model establishment,solution and application,and draws an optimized operation graph of large-scale reservoirs.The study also obtains a long-term operation strategy of river basin water resources system,the allocation schemes of allowable water withdrawal and sewage discharge in a typical year and the flow hydrographs of trans-boundary sections.The validity of the model and the allocation rationality are analyzed as well.

  10. Total Phosphorus in Surface Water (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excess phosphorus in surface water can result in eutrophication. TOTALPFuture is reported in kilograms/hectare/year. More information about these resources,...

  11. Surface processing using water cluster ion beams

    Science.gov (United States)

    Takaoka, Gikan H.; Ryuto, Hiromichi; Takeuchi, Mitsuaki; Ichihashi, Gaku

    2013-07-01

    Vaporized water clusters were produced by an adiabatic expansion phenomenon, and various substrates such as Si(1 0 0), SiO2, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and polycarbonate (PC) were irradiated by water cluster ion beams. The sputtered depth increased with increasing acceleration voltage, and the sputtering rate was much larger than that obtained using Ar monomer ion irradiation. The sputtering yield for PMMA was approximately 200 molecules per ion, at an acceleration voltage of 9 kV. X-ray photoelectron spectroscopy (XPS) measurements showed that high-rate sputtering for the PMMA surface can be ascribed to the surface erosion by the water cluster ion irradiation. Furthermore, the micropatterning was demonstrated on the PMMA substrate. Thus, the surface irradiation by water cluster ion beams exhibited a chemical reaction based on OH radicals, as well as excited hydrogen atoms, which resulted in a high sputtering rate and low irradiation damage of the substrate surfaces.

  12. Surface processing using water cluster ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Takaoka, Gikan H., E-mail: gtakaoka@kuee.kyoto-u.ac.jp [Photonics and Electronics Science and Engineering Center, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Ryuto, Hiromichi; Takeuchi, Mitsuaki; Ichihashi, Gaku [Photonics and Electronics Science and Engineering Center, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan)

    2013-07-15

    Vaporized water clusters were produced by an adiabatic expansion phenomenon, and various substrates such as Si(1 0 0), SiO{sub 2}, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and polycarbonate (PC) were irradiated by water cluster ion beams. The sputtered depth increased with increasing acceleration voltage, and the sputtering rate was much larger than that obtained using Ar monomer ion irradiation. The sputtering yield for PMMA was approximately 200 molecules per ion, at an acceleration voltage of 9 kV. X-ray photoelectron spectroscopy (XPS) measurements showed that high-rate sputtering for the PMMA surface can be ascribed to the surface erosion by the water cluster ion irradiation. Furthermore, the micropatterning was demonstrated on the PMMA substrate. Thus, the surface irradiation by water cluster ion beams exhibited a chemical reaction based on OH radicals, as well as excited hydrogen atoms, which resulted in a high sputtering rate and low irradiation damage of the substrate surfaces.

  13. Exit Creek Water Surface Survey, June 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset consists of survey data from a longitudinal profile of water surface surveyed June 23-24, 2013 at Exit Creek, a stream draining Exit Glacier in Kenai...

  14. US Forest Service Surface Drinking Water Importance

    Data.gov (United States)

    US Forest Service, Department of Agriculture — A map service on the www depicting watershed indexes to help identify areas of interest for protecting surface drinking water quality. The dataset depicted in this...

  15. Total Nitrogen in Surface Water (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excess nitrogen in surface water can result in eutrophication. TOTALNFuture is reported in kilograms/hectare/year. More information about these resources, including...

  16. Surface Waters Information Management System (SWIMS)

    Data.gov (United States)

    Kansas Data Access and Support Center — The Surface Waters Information Management System (SWIMS) has been designed to meet multi-agency hydrologic database needs for Kansas. The SWIMS project was supported...

  17. Silicon Carbide Semiconductor Surface Dielectric Barrier Discharge (SSDBD) Device for Turbulent Skin Friction Drag Reduction and Flow Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed research effort explores the use of a nanosecond pulse driven offset semiconducting surface dielectric barrier discharge (SSDBD) device for the control...

  18. Guidance on the use of passive-vapor-diffusion samplers to detect volatile organic compounds in ground-water-discharge areas, and example applications in New England

    Science.gov (United States)

    Church, Peter E.; Vroblesky, Don A.; Lyford, Forest P.

    2002-01-01

    Polyethylene-membrane passive-vapor-diffusion samplers, or PVD samplers, have been shown to be an effective and economical reconnaissance tool for detecting and identifying volatile organic compounds (VOCs) in bottom sediments of surface-water bodies in areas of ground-water discharge. The PVD samplers consist of an empty glass vial enclosed in two layers of polyethylene membrane tubing. When samplers are placed in contaminated sediments, the air in the vial equilibrates with VOCs in pore water. Analysis of the vapor indicates the presence or absence of VOCs and the likely magnitude of concentrations in pore water.

  19. Plasma Kinetics in Electrical Discharge in Mixture of Air, Water and Ethanol Vapors for Hydrogen Enriched Syngas Production

    CERN Document Server

    Shchedrin, A I; Ryabtsev, A V; Chernyak, V Ya; Yukhymenko, V V; Olszewski, S V; Naumov, V V; Prysiazhnevych, I V; Solomenko, E V; Demchina, V P; Kudryavtsev, V S

    2008-01-01

    The complex theoretical and experimental investigation of plasma kinetics of the electric discharge in the mixture of air and ethanol-water vapors is carried out. The discharge was burning in the cavity, formed by air jets pumping between electrodes, placed in aqueous ethanol solution. It is found out that the hydrogen yield from the discharge is maximal in the case when ethanol and water in the solution are in equal amounts. It is shown that the hydrogen production increases with the discharge power and reaches the saturation at high value. The concentrations of the main stable gas-phase components, measured experimentally and calculated numerically, agree well in the most cases.

  20. The contribution of groundwater discharge to the overall water budget of two typical Boreal lakes in Alberta/Canada estimated from a radon mass balance

    Directory of Open Access Journals (Sweden)

    A. Schmidt

    2010-01-01

    Full Text Available Radon-222, a naturally-occurring radioisotope with a half-life of 3.8 days, was used to estimate groundwater discharge to small lakes in wetland-dominated basins in the vicinity of Fort McMurray, Canada. This region is under significant water development pressure including both oil sands mining and in situ extraction. Field investigations were carried out in March and July 2008 to measure radon-222 distributions in the water column of two lakes as a tracer of groundwater discharge. Radon concentrations in these lakes ranged from 0.5 to 72 Bq/m3, while radon concentrations in groundwaters ranged between 2000 and 8000 Bq/m3. A radon mass balance, used in comparison with stable isotope mass balance, suggested that the two lakes under investigation had quite different proportions of annual groundwater inflow (from 0.5% to about 14% of the total annual water inflow. Lower discharge rates were attributed to a larger drainage area/lake area ratio which promotes greater surface connectivity. Interannual variability in groundwater proportions is expected despite an implied seasonal constancy in groundwater discharge rates. Our results demonstrate that a combination of stable isotope and radon mass balance approaches provides information on flowpath partitioning that is useful for evaluating surface-groundwater connectivity and acid sensitivity of individual water bodies of interest in the Alberta Oil Sands Region.

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

    Science.gov (United States)

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

    2016-04-01

    The semi-arid regions of Central Asia crucially depend on the water resources supplied by the mountainous areas of the Tien-Shan and Pamirs. During the summer months the snow and glacier melt water of the rivers originating in the mountains provides the only water resource available for agricultural production but also for water collection in reservoirs for energy production in winter months. Thus a reliable seasonal forecast of the water resources is crucial for a sustainable management and planning of water resources.. In fact, seasonal forecasts are mandatory tasks of national hydro-meteorological services in the region. Thus this study aims at a statistical forecast of the seasonal water availability, whereas the focus is put on the usage of freely available data in order to facilitate an operational use without data access limitations. The study takes the Naryn basin as a test case, at which outlet the Toktogul reservoir stores the discharge of the Naryn River. As most of the water originates form snow and glacier melt, a statistical forecast model should use data sets that can serve as proxy data for the snow masses and snow water equivalent in late spring, which essentially determines the bulk of the seasonal discharge. CRU climate data describing the precipitation and temperature in the basin during winter and spring was used as base information, which was complemented by MODIS snow cover data processed through ModSnow tool, discharge during the spring and also GRACE gravimetry anomalies. For the construction of linear forecast models monthly as well as multi-monthly means over the period January to April were used to predict the seasonal mean discharge of May-September at the station Uchterek. An automatic model selection was performed in multiple steps, whereas the best models were selected according to several performance measures and their robustness in a leave-one-out cross validation. It could be shown that the seasonal discharge can be predicted with

  2. The Dynamic Surface Tension of Water.

    Science.gov (United States)

    Hauner, Ines M; Deblais, Antoine; Beattie, James K; Kellay, Hamid; Bonn, Daniel

    2017-03-23

    The surface tension of water is an important parameter for many biological or industrial processes, and roughly a factor of 3 higher than that of nonpolar liquids such as oils, which is usually attributed to hydrogen bonding and dipolar interactions. Here we show by studying the formation of water drops that the surface tension of a freshly created water surface is even higher (∼90 mN m(-1)) than under equilibrium conditions (∼72 mN m(-1)) with a relaxation process occurring on a long time scale (∼1 ms). Dynamic adsorption effects of protons or hydroxides may be at the origin of this dynamic surface tension. However, changing the pH does not significantly change the dynamic surface tension. It also seems unlikely that hydrogen bonding or dipole orientation effects play any role at the relatively long time scale probed in the experiments.

  3. Ozone kinetics in low-pressure discharges: vibrationally excited ozone and molecule formation on surfaces

    Science.gov (United States)

    Marinov, Daniil; Guerra, Vasco; Guaitella, Olivier; Booth, Jean-Paul; Rousseau, Antoine

    2013-10-01

    A combined experimental and modeling investigation of the ozone kinetics in the afterglow of pulsed direct current discharges in oxygen is carried out. The discharge is generated in a cylindrical silica tube of radius 1 cm, with short pulse durations between 0.5 and 2 ms, pressures in the range 1-5 Torr and discharge currents ˜40-120 mA. Time-resolved absolute concentrations of ground-state atoms and ozone molecules were measured simultaneously in situ, by two-photon absorption laser-induced fluorescence and ultraviolet absorption, respectively. The experiments were complemented by a self-consistent model developed to interpret the results and, in particular, to evaluate the roles of vibrationally excited ozone and of ozone formation on surfaces. It is found that vibrationally excited ozone, O_3^{*} , plays an important role in the ozone kinetics, leading to a decrease in the ozone concentration and an increase in its formation time. In turn, the kinetics of O_3^{*} is strongly coupled with those of atomic oxygen and O2(a 1Δg) metastables. Ozone formation at the wall does not contribute significantly to the total ozone production under the present conditions. Upper limits for the effective heterogeneous recombination probability of O atoms into ozone are established.

  4. Water desorption from nanostructured graphite surfaces.

    Science.gov (United States)

    Clemens, Anna; Hellberg, Lars; Grönbeck, Henrik; Chakarov, Dinko

    2013-12-21

    Water interaction with nanostructured graphite surfaces is strongly dependent on the surface morphology. In this work, temperature programmed desorption (TPD) in combination with quadrupole mass spectrometry (QMS) has been used to study water ice desorption from a nanostructured graphite surface. This model surface was fabricated by hole-mask colloidal lithography (HCL) along with oxygen plasma etching and consists of a rough carbon surface covered by well defined structures of highly oriented pyrolytic graphite (HOPG). The results are compared with those from pristine HOPG and a rough (oxygen plasma etched) carbon surface without graphite nanostructures. The samples were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The TPD experiments were conducted for H2O coverages obtained after exposures between 0.2 and 55 langmuir (L) and reveal a complex desorption behaviour. The spectra from the nanostructured surface show additional, coverage dependent desorption peaks. They are assigned to water bound in two-dimensional (2D) and three-dimensional (3D) hydrogen-bonded networks, defect-bound water, and to water intercalated into the graphite structures. The intercalation is more pronounced for the nanostructured graphite surface in comparison to HOPG surfaces because of a higher concentration of intersheet openings. From the TPD spectra, the desorption energies for water bound in 2D and 3D (multilayer) networks were determined to be 0.32 ± 0.06 and 0.41 ± 0.03 eV per molecule, respectively. An upper limit for the desorption energy for defect-bound water was estimated to be 1 eV per molecule.

  5. Large-scale surface dielectric barrier discharge type reactor : effect of the electric wind on the conversion effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Jolibois, J. [Univ. de Poitiers, Poitiers (France). Centre national de la recherche scientifique, Laboratoire de Catalyse en Chimie Organique; Poitiers Univ., Futuroscope Chasseneuil Cedex (France). Centre national de la recherche scientifique, Inst. Pprime; Zouzou, N.; Moreau, E. [Poitiers Univ., Futuroscope Chasseneuil Cedex (France). Centre national de la recherche scientifique, Inst. Pprime; Tatibouet, J.M. [Univ. de Poitiers, Poitiers (France). Centre national de la recherche scientifique, Laboratoire de Catalyse en Chimie Organique

    2010-07-01

    Non-thermal plasma (NTP) techniques offer an innovative approach for air pollution reduction. Most studies in NTP techniques use volumetric discharge reactors with small dimensions and low flow rates at laboratory scale. The objective of this study was to develop an air pollution control plasma reactor at industrial scale with surface discharge. Propene (C{sub 3}H{sub 6}) was oxidized at high flow rates in a large-scale plasma reactor based on surface dielectric barrier discharge (DBD). Three different configurations of surface discharges were tested with 15 ppm of C{sub 3}H{sub 6} in air at ambient temperature for a flow rate of 50 m{sup 3} per hour. The properties of these different surface discharges were analyzed using chemical measurements and 3 component particle image velocimetry (PIV) measurements. PIV measurements were used characterize the effect of the electric wind on the polluted gas airflow inside the reactor and to explain the differences of effectiveness of the three tested plasma generators. For the three plasma generators, a propene oxidation of up to 45 percent was obtained at one J per liter. The electric wind produced by the surface discharge resulted in the formation of vortices inside the plasma reactor. This electric wind can increase gas mixing inside the plasma reactor and therefore plays a key role in conversion efficiency. It was concluded that the electric wind produced by surface discharges enables the use of this type of discharge for VOC elimination at high flow rate, with the same effectiveness of volumetric discharges. 5 refs., 10 figs.

  6. Direct plasma NOx reduction using single surface dielectric barrier discharge

    DEFF Research Database (Denmark)

    Kroushawi, Feisal; Stamate, Eugen

    2014-01-01

    NOx reduction using direct atmospheric barrier discharge in air-NO mixture at different voltages and flow rates is inversigated. Reduction rate of 80% is achieved at 3.18 W/cm2 power density and gas mixture of 20 slm air and 0.006 slm NO. The ozone for NO reduction is produced by a honeycomb...... structured DBD with a total surface of 12.56 cm2. The reduction process is investigated by FTIR spectroscopy, chemiluminsecence, mass spectrometry and optical emission spectroscopy....

  7. Polyfluorinated chemicals in European surface waters, ground- and drinking waters

    NARCIS (Netherlands)

    Eschauzier, C.; de Voogt, P.; Brauch, H.-J.; Lange, F.T.; Knepper, T.P.; Lange, F.T.

    2012-01-01

    Polyfluorinated chemicals (PFCs), especially short chain fluorinated alkyl sulfonates and carboxylates, are ubiquitously found in the environment. This chapter aims at giving an overview of PFC concentrations found in European surface, ground- and drinking waters and their behavior during convention

  8. Polyfluorinated chemicals in European surface waters, ground- and drinking waters

    NARCIS (Netherlands)

    Eschauzier, C.; de Voogt, P.; Brauch, H.-J.; Lange, F.T.; Knepper, T.P.; Lange, F.T.

    2012-01-01

    Polyfluorinated chemicals (PFCs), especially short chain fluorinated alkyl sulfonates and carboxylates, are ubiquitously found in the environment. This chapter aims at giving an overview of PFC concentrations found in European surface, ground- and drinking waters and their behavior during

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

    Science.gov (United States)

    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.

  10. Water dissociation in a radio-frequency electromagnetic field with ex situ electrodes—modelling of discharge initiation

    Science.gov (United States)

    Schneider, Jens; Holzer, Frank; Rabe, Carsten; Häupl, Tilmann; Kopinke, Frank-Dieter; Roland, Ulf

    2013-04-01

    Applying a new experimental design with a capillary glass reactor and plate electrodes outside of the reactor allowed the initiation of discharges in aqueous electrolytes under the influence of a radio-frequency (RF) electromagnetic field. This study focused on the mechanism leading to the initiation of such discharges in the restriction of a glass tube. The light emission correlated with discharges was analysed with optical emission spectroscopy. Electrons with energies between 20 and 45 eV were responsible for the dissociation of water molecules into (excited) OH, H and O radicals. Current-voltage characteristics were measured before and under discharge conditions. Modelling of the experimental setup and simulation of electrical field strength distribution support the hypothesis of the origin of discharges in general and experimental findings such as ring-shaped discharges and a minimum solution conductivity of about 1 S m-1 required for discharge initiation with RF voltages of 2 kV.

  11. Modification of a metallic surface in a vacuum arc discharge plasma using thermally stimulated ion diffusion

    Science.gov (United States)

    Muboyadzhyan, S. A.

    2008-12-01

    A new process for modifying a metallic surface in a vacuum arc discharge plasma using thermally stimulated ion diffusion is considered. The effect of the bias voltage (negative substrate potential) on the processes that occur on the surface of a treated part is studied when the substrate material interacts with an accelerated metallic-ion flow. The phase and elemental compositions of the modified layer are studied for substrates made of nickel-based superalloys, austenitic and martensitic steels, and titanium-based alloys. The heat resistance, the salt corrosion resistance, and the corrosion cracking resistance of steels and titanium-based alloys are investigated after their modification in vacuum arc plasmas of pure metals (Ti, Zr, Al, Cr, Y) and related alloys. The surface modification caused by the thermally stimulated ion saturation of the surfaces of parts made from structural materials is shown to change the structural-phase states of their surfaces and, correspondingly, the properties of these materials in relation to the state of the surface.

  12. Limitations of fibre optic distributed temperature sensing for quantifying surface water groundwater interactions

    Directory of Open Access Journals (Sweden)

    H. Roshan

    2014-07-01

    Full Text Available Studies of surface water–groundwater interactions using fiber optic distributed temperature sensing (FO-DTS has increased in recent years. However, only a few studies to date have explored the limitations of FO-DTS in detecting groundwater discharge to streams. A FO_DTS system was therefore tested in a flume under controlled laboratory conditions for its ability to accurately measure the discharge of hot or cold groundwater into a simulated surface water flow. In the experiment the surface water (SW and groundwater (GW velocities, expressed as ratios (vgw/vsw, were varied from 0.21% to 61.7%; temperature difference between SW-GW were varied from 2 to 10 °C; the direction of temperature gradient were varied with both cold and-hot water injection; and two different bed materials were used to investigate their effects on FO_DTS's detection limit of groundwater discharge. The ability of the FO_DTS system to detect the discharge of groundwater of a different temperature in the laboratory environment was found to be mainly dependent upon the surface and groundwater flow velocities and their temperature difference. A correlation was proposed to estimate the groundwater discharge from temperature. The correlation is valid when the ratio of the apparent temperature response to the source temperature difference is above 0.02.

  13. Impacts from oil and gas produced water discharges on the gulf of Mexico hypoxic zone.

    Energy Technology Data Exchange (ETDEWEB)

    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

  14. Surface modification of austenitic steel by various glow-discharge nitriding methods

    Directory of Open Access Journals (Sweden)

    Tomasz Borowski

    2015-09-01

    Full Text Available Recent years have seen intensive research on modifying glow-discharge nitriding processes. One of the most commonly used glow-discharge methods includes cathodic potential nitriding (conventional method, and active screen plasma nitriding. Each of these methods has a number of advantages. One very important, common feature of these techniques is full control of the microstructure, chemical and phase composition, thickness and the surface topography of the layers formed. Another advantage includes the possibility of nitriding such materials as: austenitic steels or nickel alloys, i.e. metallic materials which do not diffuse nitrogen as effectively as ferritic or martensitic steels. However, these methods have some disadvantages as well. In the case of conventional plasma nitriding, engineers have to deal with the edge effect, which makes it difficult to use this method for complexly shaped components. In turn, in the case of active screen plasma nitriding, the problem disappears. A uniform, smooth layer forms, but is thinner, softer and is not as resistant to friction compared to layers formed using the conventional method. Research is also underway to combine these methods, i.e. use an active screen in conventional plasma nitriding at cathodic potential. However, there is a lack of comprehensive data presenting a comparison between these three nitriding processes and the impact of pulsating current on the formation of the microstructure and functional properties of austenitic steel surfaces. The article presents a characterisation of nitrided layers produced on austenitic X2CrNiMo17-12-2 (AISI 316L stainless steel in the course of glow-discharge nitriding at cathodic potential, at plasma potential and at cathodic potential incorporating an active screen. All processes were carried out at 440 °C under DC glow-discharge conditions and in 100 kHz frequency pulsating current. The layers were examined in terms of their microstructure, phase and

  15. Surface modification of austenitic steel by various glow-discharge nitriding methods

    Directory of Open Access Journals (Sweden)

    Tomasz Borowski

    2015-09-01

    Full Text Available Recent years have seen intensive research on modifying glow-discharge nitriding processes. One of the most commonly used glow-discharge methods includes cathodic potential nitriding (conventional method, and active screen plasma nitriding. Each of these methods has a number of advantages. One very important, common feature of these techniques is full control of the microstructure, chemical and phase composition, thickness and the surface topography of the layers formed. Another advantage includes the possibility of nitriding such materials as: austenitic steels or nickel alloys, i.e. metallic materials which do not diffuse nitrogen as effectively as ferritic or martensitic steels. However, these methods have some disadvantages as well. In the case of conventional plasma nitriding, engineers have to deal with the edge effect, which makes it difficult to use this method for complexly shaped components. In turn, in the case of active screen plasma nitriding, the problem disappears. A uniform, smooth layer forms, but is thinner, softer and is not as resistant to friction compared to layers formed using the conventional method. Research is also underway to combine these methods, i.e. use an active screen in conventional plasma nitriding at cathodic potential. However, there is a lack of comprehensive data presenting a comparison between these three nitriding processes and the impact of pulsating current on the formation of the microstructure and functional properties of austenitic steel surfaces. The article presents a characterisation of nitrided layers produced on austenitic X2CrNiMo17-12-2 (AISI 316L stainless steel in the course of glow-discharge nitriding at cathodic potential, at plasma potential and at cathodic potential incorporating an active screen. All processes were carried out at 440 °C under DC glow-discharge conditions and in 100 kHz frequency pulsating current. The layers were examined in terms of their microstructure, phase and

  16. Equations of atrazine transfer from agricultural land to surface water

    Science.gov (United States)

    Cann, C.

    1995-08-01

    As atrazine, the most widely used herbicide in agriculture, makes problems for water supply, the Cemagref study its transfer from lands to surface water. On a small basin of central Brittany, soil and water contents of atrazine have been monitored from 1991 to 1994. Data show that atrazine content of the top layer of soil decreases slowly after spreading. Degradation works more than leaching for this decrease. There is always atrazine in the water of the stream at the outlet of the basin. The concentration of atrazine in water increase sharply in every flood and then decrease slowly. The maximum level of concentration in each flood is very well correlated with the ratio of maximum discharge to the base flow. It means that quick superficial flow of water is the most contaminated water. It brings most of the total flow of atrazine which can be measured in the stream. However, this flow represent only a very small part of the spread atrazine on the basin: less than 1%.

  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

    Science.gov (United States)

    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. The influence of circuit inductance on the energy characteristics of electric discharge and deformation of plates in water

    Science.gov (United States)

    Kosenkov, V. M.; Bychkov, V. M.

    2017-08-01

    We have experimentally studied the influence of discharge-circuit inductance on the efficiency of conversion of energy stored in a capacitor bank, evolved in the electric-discharge channel in water, and spent for the resulting plastic deformation of plates. It is established for the first time that a growth in inductance of the discharge circuit produces a positive effect on the deformation of plates by increasing the amount of energy spent in this process.

  19. EFFECT OF THE CRITICAL IRRADIANCE ON PHOTOVOLTAIC WATER PUMP DISCHARGE UNDER EGYPTIAN CONDITIONS

    Directory of Open Access Journals (Sweden)

    Mamdouh Abbas HELMY

    2015-04-01

    Full Text Available The present investigation aimed to study the effect of critical irradiance due to changing tilt angle of PV panel and tracking sun on submersible pump discharge. The authors used solar tracker and suitable tilt angle for the panel to increase the time interval during which the water pump operates. For the same irradiance collected by the PV, all systems pump the same amount of water, although they occur at different periods of the day. The pump itself 'does not know whether the electric power comes from any processes, as long as it has the same intensity.

  20. Combined Sewer Overflows as a Source of Hormones to Surface Water

    Science.gov (United States)

    Phillips, P.; Chalmers, A.; Gray, J. L.; Foreman, W.; Kolpin, D. W.; Wall, G.; Esposito, K.

    2009-12-01

    Some sources of hormones to surface water, such as wastewater-treatment-plant (WWTP) effluent, have been well documented, but other sources, particularly wet-weather discharges from combined-sewer-overflows (CSOs), are not well characterized. Flow-weighted composite samples of secondarily treated WWTP effluent and untreated sewage discharges from WWTP inflows and CSO discharges were collected during 12 storms and 6 non-storm conditions from November 2007-December 2008 at the main Burlington Vermont WWTP. Concentrations of many androgens and estrogens were highest in samples from untreated sewage, and lower in samples from treated sewage. For example, concentrations of estriol in CSO samples ranged from 5 to over 100 ng/L (nanograms per liter), but were generally less than 1 ng/L in treated sewage. Many androgens were detected in CSO discharge samples in concentrations ranging from 1 to over 1000 ng/L, but were not detected above 1 ng/L in treated samples. For many of the hormones, including androgens and estriol, CSO discharges comprised over half of the total load discharged by the WWTP, even though annual CSO discharge is less than 10% of the treated plant discharge. These results indicate that untreated discharges during CSO events can be a major source of some hormones and other wastewater compounds to the environment.

  1. Surface nitridation of silicon nano-particles using double multi-hollow discharge plasma CVD

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Giichiro; Yamamoto, Kosuke; Kawashima, Yuki; Sato, Muneharu; Nakahara, Kenta; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu [Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka (Japan); Kamataki, Kunihiro [Center for Reserch and Advancement in Higher Education, Kyushu University, Fukuoka (Japan); Kondo, Michio [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki (Japan)

    2011-10-15

    We present production of silicon nano-particles and their surface nitridation for efficient multiple-exciton generation. Nitridated silicon nano-particles were produced using double multi-hollow discharge plasma CVD, where generation of silicon particles and their nitridation were independently performed using SiH{sub 4}/H{sub 2} and N{sub 2} multi-hollow discharge plasmas. We succeeded in controlling nitrogen content in a silicon nano-particle by varying a number density of N radicals irradiated to the Si particle. We also observed strong photoluminescence (PL) emission around 300-500 nm from silicon nano-particles, where the PL peak energy is about 2.5 and 3.1 eV for pure Si nano-particles, and 2.5, 3.1, and 4.1 eV for nitridated Si nano-particles. The additional UV-peak of 4.1 eV from nitridated Si particles is closely related to the nitridation surface layer on Si nano-particles (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Shaping of steel mold surface of lens array by electrical discharge machining with spherical ball electrode.

    Science.gov (United States)

    Takino, Hideo; Hosaka, Takahiro

    2016-06-20

    We propose a method for fabricating a spherical lens array mold by electrical discharge machining (EDM) with a ball-type electrode. The electrode is constructed by arranging conductive spherical balls in an array. To fundamentally examine the applicability of the proposed EDM method to the fabrication of lens array molds, we use an electrode having a single ball to shape a lens array mold made of stainless steel with 16 spherical elements, each having a maximum depth of 0.5 mm. As a result, a mold surface is successfully shaped with a peak-to-valley shape accuracy of approximately 10 μm, and an average surface roughness of 0.85 μm.

  3. Controlled cytotoxicity of plasma treated water formulated by open-air hybrid mode discharge

    Science.gov (United States)

    Lu, P.; Boehm, D.; Cullen, P.; Bourke, P.

    2017-06-01

    Plasma treated liquids (PTLs) provide a means to convey a broad range of effects of relevance for food, environmental, or clinical decontamination, plant growth promotion, and therapeutic applications. Devising the reactive species ingredients and controlling the biological response of PTLs are of great interest. We demonstrate an approach by using an open-air hybrid mode discharge (HMD) to control the principal reactive species composition within plasma treated water (PTW), which is then demonstrated to regulate the cytotoxicity of PTW. The cytotoxicity of HMD produced PTW demonstrates a non-monotonic change over the discharge time. Although hydrogen peroxide and nitrite are not the sole effectors for cell death caused by PTW, using them as principal reactive species indicators, cytotoxicity can be removed and/or enhanced by formulating their concentrations and composition through adjusting the discharge mode and time on-line during PTW generation without the addition of additional working gas or chemical scavengers. This work demonstrates that a hybrid mode discharge can be employed to generate a PTW formulation to control a biological response such as cytotoxicity. This provides insights into how plasma treated liquids may be harnessed for biological applications in a specific and controllable manner.

  4. Simulated and experimental studies on the array dielectric barrier discharge of water electrodes

    Science.gov (United States)

    Lele, WANG; Xiutao, HUANG; Junfeng, CHEN; Shengming, WANG; Zhaoyang, HU; Minghai, LIU

    2017-03-01

    A kind of dielectric barrier discharge (DBD) device composed of water electrodes with 3 × 3 forms can produce large-area low-temperature plasmas at atmospheric pressure. To reflect the discharge characteristics of DBD better, a dynamic simulation model, which is based on the voltage controlled current source (CCS), is established, then the established model in Matlab/Simulink is used to simulate the DBD in air. The voltage–current waves and Lissajous at a voltage of 10 kV, 11 kV and 12 kV peak value with a frequency of 15 kHz are studied. The change of the discharge power of DBD with a different amplitude and frequency of applied voltage is also analyzed. The result shows the voltage–current waves, Lissajous and discharge power of DBD under different conditions from the simulation agree well with those of the experiment. In addition, we propose a method to calculate the dielectric barrier capacitance {{C}}{{d}} and the gap capacitance {{C}}{{g}}, which is valid through analyzing the variation of capacitance at different voltage amplitudes.

  5. Simulated and experimental studies on the array dielectric barrier discharge of water electrodes

    Science.gov (United States)

    Wang, Lele; Huang, Xiutao; Chen, Junfeng; Wang, Shengming; Hu, Zhaoyang; Liu, Minghai

    2017-03-01

    A kind of dielectric barrier discharge (DBD) device composed of water electrodes with 3 × 3 forms can produce large-area low-temperature plasmas at atmospheric pressure. To reflect the discharge characteristics of DBD better, a dynamic simulation model, which is based on the voltage controlled current source (CCS), is established, then the established model in Matlab/Simulink is used to simulate the DBD in air. The voltage-current waves and Lissajous at a voltage of 10 kV, 11 kV and 12 kV peak value with a frequency of 15 kHz are studied. The change of the discharge power of DBD with a different amplitude and frequency of applied voltage is also analyzed. The result shows the voltage-current waves, Lissajous and discharge power of DBD under different conditions from the simulation agree well with those of the experiment. In addition, we propose a method to calculate the dielectric barrier capacitance {{C}}{{d}} and the gap capacitance {{C}}{{g}}, which is valid through analyzing the variation of capacitance at different voltage amplitudes.

  6. Investigation on the characteristics of a two gap capillary discharge based on surface flash over ignition in atmosphere

    Science.gov (United States)

    Huang, Dong; Yang, Lanjun; Huo, Peng; Ma, Jiangbo; Guo, Haishan; Xu, Ran; Ding, Weidong

    2016-09-01

    In this paper, a two gap capillary (TGC) structure is presented and the corresponding driving circuit based on surface flashover ignition is designed to achieve reliable and repetitive discharge in atmosphere. The characteristics of the two gap capillary (TGC) discharge in low energy are investigated, of which the discharge energy is from 27 J to 432 J. With the rise of charging voltage, the delay of the weak capillary discharge and the main discharge both decrease. Meanwhile, the current flowing through the main gap and the plasma jet ejection are enhanced. The main gap resistance is about several hundreds of milliohms in the main discharge and rises gradually with the decay of the current. The long tail extinction is witnessed at the relatively low charging voltage of 0.5 kV and 1.0 kV, by which the pulse width of the discharge is extended. However, the discharge during the long tail extinction contributes little to the plasma jet ejection with negligible plasma jet velocity and low degree of the plasma ionization. The effective energy deposition efficiency on the main gap increases gradually with the charging voltage and reaches approximately 2 times higher than that of the traditional structure at the charging voltage of 2.0 kV. The series inductor in the circuit can restrain the development of the long tail extinction and increase the effective energy deposition efficiency. Thus, the discharge characteristics and the plasma ejection of TGC under the relatively low charging voltage are optimized.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  9. Stable water layers on solid surfaces.

    Science.gov (United States)

    Hong, Ying-Jhan; Tai, Lin-Ai; Chen, Hung-Jen; Chang, Pin; Yang, Chung-Shi; Yew, Tri-Rung

    2016-02-17

    Liquid layers adhered to solid surfaces and that are in equilibrium with the vapor phase are common in printing, coating, and washing processes as well as in alveoli in lungs and in stomata in leaves. For such a liquid layer in equilibrium with the vapor it faces, it has been generally believed that, aside from liquid lumps, only a very thin layer of the liquid, i.e., with a thickness of only a few nanometers, is held onto the surface of the solid, and that this adhesion is due to van der Waals forces. A similar layer of water can remain on the surface of a wall of a microchannel after evaporation of bulk water creates a void in the channel, but the thickness of such a water layer has not yet been well characterized. Herein we showed such a water layer adhered to a microchannel wall to be 100 to 170 nm thick and stable against surface tension. The water layer thickness was measured using electron energy loss spectroscopy (EELS), and the water layer structure was characterized by using a quantitative nanoparticle counting technique. This thickness was found for channel gap heights ranging from 1 to 5 μm. Once formed, the water layers in the microchannel, when sealed, were stable for at least one week without any special care. Our results indicate that the water layer forms naturally and is closely associated only with the surface to which it adheres. Our study of naturally formed, stable water layers may shed light on topics from gas exchange in alveoli in biology to the post-wet-process control in the semiconductor industry. We anticipate our report to be a starting point for more detailed research and understanding of the microfluidics, mechanisms and applications of gas-liquid-solid systems.

  10. Decontamination of Streptococci biofilms and Bacillus cereus spores on plastic surfaces with DC and pulsed corona discharges

    Science.gov (United States)

    Koval'ová, Zuzana; Tarabová, Kataŕna; Hensel, Karol; Machala, Zdenko

    2013-02-01

    Cold air plasmas of DC and pulsed corona discharges: positive streamers and negative Trichel pulses were used for bio-decontamination of Streptococci biofilm and Bacillus cereus spores on polypropylene plastic surfaces. The reduction of bacterial population (evaluated as log10) in the biofilm on plastic surfaces treated by DC corona reached 2.4 logs with 10 min treatment time and 3.3 logs with 2 min treatment time with water spraying. The enhancement of plasma biocidal effects on the biofilm by electro-spraying of water through a hollow needle high-voltage electrode was investigated. No significant polarity effect was found with DC corona. Pulsed corona was demonstrated slightly more bactericidal for spores, especially in the negative polarity where the bacterial population reduction reached up to 2.2 logs at 10 min exposure time. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.

  11. Kinetics and dynamics of nanosecond streamer discharge in atmospheric-pressure gas bubble suspended in distilled water under saturated vapor pressure conditions

    KAUST Repository

    Sharma, Ashish

    2016-09-08

    We perform computational studies of nanosecond streamer discharges generated in helium bubbles immersed in distilled water under atmospheric pressure conditions. The model takes into account the presence of water vapor in the gas bubble for an accurate description of the discharge kinetics. We find that the dynamic characteristics of the streamer discharge are different at low and high positive trigger voltages with the axial streamer evolution dominant for low voltages and a surface hugging mode favored for high voltages. We also find a substantial difference in initiation, transition and evolution stages of discharge for positive and negative trigger voltages with the volumetric distribution of species in the streamer channel much more uniform for negative trigger voltages on account of the presence of multiple streamers. We observe that the presence of water vapor does not affect the breakdown voltage even for oversaturated conditions but significantly influences the composition of dominant species in the trail of the streamer as well as the flux of the dominant species on the bubble surface. © 2016 IOP Publishing Ltd.

  12. Kinetics and dynamics of nanosecond streamer discharge in atmospheric-pressure gas bubble suspended in distilled water under saturated vapor pressure conditions

    Science.gov (United States)

    Sharma, Ashish; Levko, Dmitry; Raja, Laxminarayan L.; Cha, Min Suk

    2016-10-01

    We perform computational studies of nanosecond streamer discharges generated in helium bubbles immersed in distilled water under atmospheric pressure conditions. The model takes into account the presence of water vapor in the gas bubble for an accurate description of the discharge kinetics. We find that the dynamic characteristics of the streamer discharge are different at low and high positive trigger voltages with the axial streamer evolution dominant for low voltages and a surface hugging mode favored for high voltages. We also find a substantial difference in initiation, transition and evolution stages of discharge for positive and negative trigger voltages with the volumetric distribution of species in the streamer channel much more uniform for negative trigger voltages on account of the presence of multiple streamers. We observe that the presence of water vapor does not affect the breakdown voltage even for oversaturated conditions but significantly influences the composition of dominant species in the trail of the streamer as well as the flux of the dominant species on the bubble surface.

  13. One-step process for superhydrophobic metallic surfaces by wire electrical discharge machining.

    Science.gov (United States)

    Bae, Won Gyu; Song, Ki Young; Rahmawan, Yudi; Chu, Chong Nam; Kim, Dookon; Chung, Do Kwan; Suh, Kahp Y

    2012-07-25

    We present a direct one-step method to fabricate dual-scale superhydrophobic metallic surfaces using wire electrical discharge machining (WEDM). A dual-scale structure was spontaneously formed by the nature of exfoliation characteristic of Al 7075 alloy surface during WEDM process. A primary microscale sinusoidal pattern was formed via a programmed WEDM process, with the wavelength in the range of 200 to 500 μm. Notably, a secondary roughness in the form of microcraters (average roughness, Ra: 4.16 to 0.41 μm) was generated during the exfoliation process without additional chemical treatment. The low surface energy of Al 7075 alloy (γ = 30.65 mJ/m(2)) together with the presence of dual-scale structures appears to contribute to the observed superhydrophobicity with a static contact angle of 156° and a hysteresis less than 3°. To explain the wetting characteristics on dual-scale structures, we used a simple theoretical model. It was found that Cassie state is likely to present on the secondary roughness in all fabricated surfaces. On the other hand, either Wenzel or Cassie state can present on the primary roughness depending on the characteristic length of sinusoidal pattern. In an optimal condition of the serial cutting steps with applied powers of ∼30 and ∼8 kW, respectively, a stable, superhydrophobic metallic surface was created with a sinusoidal pattern of 500 μm wavelength.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2017-03-01

    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.

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

    Science.gov (United States)

    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. Application of Glow Discharge Aes for Investigation of Metal Ions and Water in Biology and Medicine

    CERN Document Server

    Bregadze, Vasil G; Tsakadze, Ketevan J

    2007-01-01

    AES VHF inductively coupled plasmatron may be applied to wide range of studies. It enables rapid microanalysis of various solutions including biological objects and peripheral blood serum. In addition, it may be used for investigation of water desorption from solid bodies and for determination of energetic metal-macromolecule complexes. Study of hydration energy and hydration number by kinetic curves of water glow discharge atomic spectral analysis of hydrogen (GD EAS analysis of hydrogen) desorption from Na-DNA humidified fibers allowed to reveal that structural and conformational changes in activation energy of hydrated water molecules increases by 0.65kcal/Mole of water. The developed method of analysis of elements in solutions containing high concentrations of organic materials allows systematic study of practically healthy persons and reveals risk factors for several diseases. Microelemental content of blood serum fractions showed that amount of not bounded with ceruloplasmin copper was three times more ...

  18. Surface treatment of polypropylene (PP) film by 50 Hz dielectric barrier discharge produced in air and argon/air mixture at atmospheric pressure

    Science.gov (United States)

    Joshi, Ujjwal Man; Subedi, Deepak Prasad

    2015-07-01

    Thin films of polypropylene (PP) are treated for improving hydrophilicity using non-thermal plasma generated by 50 Hz line frequency dielectric barrier discharge produced in air and argon/air mixture at atmospheric pressure. PP samples before and after the treatments are studied using contact angle measurements, surface free energy calculations and scanning electron microscopy (SEM). Distilled water (H2O), glycerol (C3H8O3) and diiodomethane (CH2I2) are used as test liquids. The contact angle measurements between test liquids and PP samples are used to determine total surface free energy using sessile drop technique. PP films show a remarkable increase in surface free energy after plasma treatment. SEM analysis of the plasma-treated PP films shows that plasma treatment introduces greater roughness on the surface leading to the increased surface free energy. Furthermore, it is found that introducing a small quantity of argon can enhance the surface treatment remarkably.

  19. Surface treatment of high density polyethylene (HDPE film by 50 Hz dielectric barrier discharge produced in air and argon/air mixture at atmospheric pressure

    Directory of Open Access Journals (Sweden)

    Joshi Ujjwal Man

    2015-03-01

    Full Text Available Thin films of high density polyethylene (HDPE are treated for improving hydrophilicity using non-thermal plasma generated by 50 Hz line frequency dielectric barrier discharge produced in air and argon/air mixture at atmospheric pressure. HDPE samples before and after the treatment are studied using contact angle measurements, surface free energy calculations and atomic force microscopy (AFM. Distilled water (H2O, glycerol (C3H8O3 and diiodomethane (CH2I2 are used as test liquids. The contact angle measurements between test liquids and HDPE samples are used to determine total surface free energy using sessile drop technique. HDPE films show a remarkable increase in surface free energy after plasma treatment. AFM analysis of the plasma-treated HDPE films shows that plasma treatment introduces greater roughness on the surface leading to the increased surface free energy. Furthermore, it is found that introducing a small quantity of argon can enhance the surface treatment remarkably.

  20. Technical and economic aspects of purification strategies to minimise discharge water from companies with closed soilless cultivation systems

    NARCIS (Netherlands)

    Os, E.A. van; Bruins, M.; Beerling, E.; Jurgens, R.; Appelman, W.; Enthoven, N.

    2014-01-01

    The aim of the research project was to achieve closure by two complementary means: 1) maximising reuse of the nutrient solution by solving problems in recirculation that leads to discharge, and 2) purification of the left over discharged water. In this paper the technical and economic aspects of pur

  1. Technical and economic aspects of purification strategies to minimise discharge water from companies with closed soilless cultivation systems

    NARCIS (Netherlands)

    Os, van E.A.; Bruins, M.A.; Beerling, E.A.M.; Jurgens, R.; Appelman, W.; Enthoven, N.

    2014-01-01

    The aim of the research project was to achieve closure by two complementary means: 1) maximising reuse of the nutrient solution by solving problems in recircula-tion that leads to discharge, and 2) purification of the left over discharged water. In this paper the technical and economic aspects of

  2. Plasma-Surface Interactions in Hollow Cathode Discharges for Electric Propulsion

    Science.gov (United States)

    Capece, Angela Maria

    Electric thrusters generate high exhaust velocities and can achieve specific impulses in excess of 1000 s. The low thrust generation and high specific impulse make electric propulsion ideal for interplanetary missions, spacecraft station keeping, and orbit raising maneuvers. Consequently, these devices have been used on a variety of space missions including Deep Space 1, Dawn, and hundreds of commercial spacecraft in Earth orbit. In order to provide the required total impulses, thruster burn time can often exceed 10,000 hours, making thruster lifetime essential. One of the main life-limiting components on ion engines is the hollow cathode, which serves as the electron source for ionization of the xenon propellant gas. Reactive contaminants such as oxygen can modify the cathode surface morphology and degrade the electron emission properties. Hollow cathodes that operate with reactive impurities in the propellant will experience higher operating temperatures, which increase evaporation of the emission materials and reduce cathode life. A deeper understanding of the mechanisms initiating cathode failure will improve thruster operation, increase lifetime, and ultimately reduce cost. A significant amount of work has been done previously to understand the effects of oxygen poisoning on vacuum cathodes; however, the xenon plasma adds complexity, and its role during cathode poisoning is not completely understood. The work presented here represents the first attempt at understanding how oxygen impurities in the xenon discharge plasma alter the emitter surface and affect operation of a 4:1:1 BaO-CaO-Al2O3 hollow cathode. A combination of experimentation and modeling was used to investigate how oxygen impurities in the discharge plasma alter the emitter surface and reduce the electron emission capability. The experimental effort involved operating a 4:1:1 hollow cathode at various conditions with oxygen impurities in the xenon flow. Since direct measurements of the emitter

  3. Research on the degradation mechanism of pyridine in drinking water by dielectric barrier discharge.

    Science.gov (United States)

    Li, Yang; Yi, Rongjie; Yi, Chengwu; Zhou, Biyun; Wang, Huijuan

    2017-03-01

    Pyridine, an important chemical raw material, is widely used in industry, for example in textiles, leather, printing, dyeing, etc. In this research, a dielectric barrier discharge (DBD) system was developed to remove pyridine, as a representative type of nitrogen heterocyclic compound in drinking water. First, the influence of the active species inhibitors tertiary butanol alcohol (TBA), HCO3(-), and CO3(2-) on the degradation rate of pyridine was investigated to verify the existence of active species produced by the strong ionization discharge in the system. The intermediate and final products generated in the degradation process of pyridine were confirmed and analyzed through a series of analytical techniques, including liquid chromatography-mass spectrometry (LC-MS), high performance liquid chromatography (HPLC), ion chromatography (IC), total organic carbon (TOC) analysis, ultraviolet (UV) spectroscopy, etc. The results showed that the degradation of pyridine was mainly due to the strong oxidizing power of ozone and hydroxyl radical produced by the DBD system. Several intermediate products including 3-hydroxyl pyridine, fumaric acid, 2, 3-dihydroxypyridine, and oxalic acid were detected. Nitrogen was removed from the pyridine molecule to form nitrate. Through analysis of the degradation mechanism of pyridine, the oxidation pathway was deduced. The study provided a theoretical and experimental basis for the application of DBD strong ionization discharge in treatment of nitrogen heterocyclic compounds in drinking water. Copyright © 2016. Published by Elsevier B.V.

  4. Illegal discharges in Spanish waters. Analysis of the profile of the Alleged Offending Vessel.

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Radiolysis of water with aluminum oxide surfaces

    Science.gov (United States)

    Reiff, Sarah C.; LaVerne, Jay A.

    2017-02-01

    Aluminum oxide, Al2O3, nanoparticles with water were irradiated with γ-rays and 5 MeV He ions followed by the determination of the production of molecular hydrogen, H2, and characterization of changes in the particle surface. Surface analysis techniques included: diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), nitrogen absorption with the Brunauer - Emmett - Teller (BET) methodology for surface area determination, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Production of H2 by γ-ray radiolysis was determined for samples with adsorbed water and for Al2O3 - water slurries. For Al2O3 samples with adsorbed water, the radiation chemical yield of H2 was measured as 80±20 molecules/100 eV (1 molecule/100 eV=1.04×10-7 mol/J). The yield of H2 was observed to decrease as the amount of water present in the Al2O3 - water slurries increased. Surface studies indicated that the α-phase Al2O3 samples changed phase following irradiation by He ions, and that the oxyhydroxide layer, present on the pristine sample, is removed by γ-ray and He ion irradiation.

  6. Water vapor interactions with polycrystalline titanium surfaces

    Science.gov (United States)

    Azoulay, A.; Shamir, N.; Volterra, V.; Mintz, M. H.

    1999-02-01

    The initial interactions of water vapor with polycrystalline titanium surfaces were studied at room temperature. Measurements of water vapor surface accumulation were performed in a combined surface analysis system incorporating direct recoils spectrometry (DRS), Auger electron spectroscopy and X-ray photoelectron spectroscopy. The kinetics of accommodation of the water dissociation fragments (H, O and OH) displayed a complex behavior depending not only on the exposure dose but also on the exposure pressure. For a given exposure dose the efficiency of chemisorption increased with increasing exposure pressure. DRS measurements indicated the occurrence of clustered hydroxyl moieties with tilted O-H bonds formed even at very low surface coverage. A model which assumes two parallel routes of chemisorption, by direct collisions (Langmuir type) and by a precursor state is proposed to account for the observed behavior. The oxidation efficiency of water seemed to be much lower than that of oxygen. No Ti 4+ states were detected even at high water exposure values. It is likely that hydroxyl species play an important role in the reduced oxidation efficiency of water.

  7. Competitive and synergistic effects between excimer VUV radiation and O radicals on the etching mechanisms of polyethylene and fluoropolymer surfaces treated by an atmospheric He–O2 post-discharge

    OpenAIRE

    Dufour, Thierry; Hubert, J.; Vandencasteele, N; Viville, P; Lazzaroni, R; Reniers, F

    2013-01-01

    International audience; Among various surface modification techniques, plasma can be used as a source for tailoring the surface properties of diverse materials. HDPE and fluoropolymer surfaces have been treated by the post-discharge of an atmospheric RF-plasma torch supplied with helium and oxygen gases. The plasma-treated surfaces were characterized by measurements of mass losses, water contact angles, x-ray photoelectron spectroscopy and atomic force microscopy. This experimental approach c...

  8. An Improved Method for Interpretation of Concentration-Discharge Relationships in Riverine Water-Quality Data

    Science.gov (United States)

    Zhang, Q.; Harman, C. J.; Ball, W. P.

    2016-12-01

    Riverine concentration-discharge (C-Q) relationships are powerful indicators that can provide important clues toward understanding nutrient and sediment export dynamics from river systems, and the analysis of such relations has been a long-standing topic of importance in hydrologic literature. Proper interpretation of such relationships can be made complex, however, if the relationships of ln(C) ln(Q) are nonlinear or if the relationships change over time, season, or discharge. Methods of addressing these issues by "binning" data or smoothing trends can introduce artifacts and ambiguities that obscure underlying interactions among time, discharge, and season. Here we illustrate these issues with examples and propose an alternative method that uses the regression coefficients of the recently-developed WRTDS ("Weighted Regressions on Time, Discharge, and Season") model for examining riverine C-Q relationships, including their uncertainty. The method is applied to sediment concentration data from Susquehanna River at Conowingo Dam (Maryland, USA) to illustrate how the WRTDS coefficients can be accessed and presented in ways that provide additional insights toward the interpretation of river water-quality data. For this case, the results clearly reveal that sediment concentration in the reservoir effluent has become more sensitive to discharge at moderate and high flows (but not very low flows) as it approaches sediment storage capacity, reaffirming the recently-documented decadal-scale decline in reservoir trapping performance. The study also highlights an additional benefit of the method, which is the ability to perform uncertainty analyses. The proposed approach can be implemented by running additional R codes within the WRTDS software - such codes are made available to users through a DOI-referenced archive site (http://dx.doi.org/10.7281/T18G8HM0) that will be maintained for at least five years after publication.

  9. Characterization of a direct dc-excited discharge in water by optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, Peter; Leys, Christophe [Department of Applied Physics, Ghent University, Jozef Plateaustraat 22, B-9000 Ghent (Belgium); Schram, Daan [Department of Applied Physics, Technische Universiteit Eindhoven, PO Box 513, 5600 MB Eindhoven (Netherlands); Gonzalez, Manuel A [Departamento de Fisica Aplicada, Universidad de Valladolid, 47011 Valladolid (Spain); Rego, Robby [Flemish Institute of Technological Research, VITO Materials, Boeretang 200, B-2400 Mol (Belgium); Kong, Michael G [Department of Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)], E-mail: peter.bruggeman@ugent.be

    2009-05-01

    Dc-excited discharges generated in water at the tip of a tungsten wire which is located at the orifice of a quartz capillary are investigated by time-averaged optical emission spectroscopy. Two distinctive discharge modes are observed. For small conductivities of the liquid the discharge is a streamer-like discharge in the liquid itself (liquid mode). For conductivities above typically 45 {mu}S cm{sup -1} a large vapour bubble is formed and a streamer discharge in this vapour bubble is observed (bubble mode). Plasma temperatures and electron densities are investigated for both modes. The gas temperature is estimated from the rotational temperature of N{sub 2}(C-B) and is 1600 {+-} 200 K for the bubble mode and 1900 {+-} 200 K for the liquid mode. The rotational temperature of OH(A-X) is up to 2 times larger and cannot be used as an estimate for the gas temperature. The rotational population distribution of OH(A), {nu} = 0 is also non-Boltzmann with a large overpopulation of high rotational states. This discrepancy in rotational temperatures is discussed in detail. Electron densities are obtained from the Stark broadening of the hydrogen Balmer beta line. The electron densities in the liquid mode are of the order of 10{sup 21} m{sup -3}. In the bubble mode electron densities are significantly smaller: (3-4) x 10{sup 20} m{sup -3}. These values are compared with the Stark broadening of the hydrogen alpha and gamma lines and with electron densities obtained from current density measurements. The chemical reactivities of the bubble and liquid modes are compared by means of the hydrogen peroxide production rate.

  10. A Water Rich Mars Surface Mission Scenario

    Science.gov (United States)

    Hoffman, Stephen; Andrews, Alida; Joosten, Kent; Watts, Kevin

    2017-01-01

    The surface of Mars once had abundant water flowing on its surface, but now there is a general perception that this surface is completely dry. Several lines of research have shown that there are sources of potentially large quantities of water at many locations on the surface, including regions considered as candidates for future human missions. Traditionally, system designs for these human missions are constrained to tightly recycle water and oxygen, and current resource utilization strategies involve ascent vehicle oxidizer production only. But the assumption of relatively abundant extant water may change this. Several scenarios were constructed to evaluate water requirements for human Mars expeditions to assess the impact to system design if locally produced water is available. Specifically, we have assessed water resources needed for 1) ascent vehicle oxidizer and fuel production, 2) open-loop water and oxygen life support requirements along with more robust usage scenarios, and 3) crew radiation protection augmentation. In this assessment, production techniques and the associated chemistry to transform Martian water and atmosphere into these useful commodities are identified, but production mass and power requirements are left to future analyses. The figure below illustrates the type of water need assessment performed and that will be discussed. There have been several sources of feedstock material discussed in recent literature that could be used to produce these quantities of water. This paper will focus on Mars surface features that resemble glacier-like forms on Earth. Several lines of evidence indicate that some of these features are in fact buried ice, likely remnants from an earlier ice age on Mars. This paper examines techniques and hardware systems used in the polar regions of Earth to access this buried ice and withdraw water from it. These techniques and systems will be described to illustrate options available. A technique known as a Rodriguez Well

  11. Recharge and discharge of near-surface groundwater in Forsmark. Comparison of classification methods

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Kent [Golder Associates AB, Uppsala (Sweden); Johansson, Per-Olof [Artesia Grundvattenkonsult AB, Taeby (Sweden); Brydsten, Lars [Umeaa University, Dept. of Ecology and Environmental Science (Sweden); Bosson, Emma; Berglund, Sten [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2007-03-15

    This report presents and compares data and models for identification of near-surface groundwater recharge and discharge (RD) areas in Forsmark. The general principles of groundwater recharge and discharge are demonstrated and applied to interpret hydrological and hydrogeological observations made in the Forsmark area. 'Continuous' RD classification methods considered in the study include topographical modelling, map overlays, and hydrological-hydrogeological flow modelling. 'Discrete' (point) methods include field-based and hydrochemistry-based RD classifications of groundwater monitoring well locations. The topographical RD modelling uses the digital elevation model as the only input. The map overlays use background maps of Quaternary deposits, soils, and ground- and field layers of the vegetation/land use map. Further, the hydrological-hydrogeological modelling is performed using the MIKE SHE-MIKE 11 software packages, taking into account e.g. topography, meteorology, hydrogeology, and geometry of watercourses and lakes. The best between-model agreement is found for the topography-based model and the MIKE SHE-MIKE 11 model. The agreement between the topographical model and the map overlays is less good. The agreement between the map overlays on the one hand, and the MIKE SHE and field-based RD classifications on the other, is thought to be less good, as inferred from the comparison made with the topography-based model. However, much improvement of the map overlays can likely be obtained, e.g. by using 'weights' and calibration (such exercises were outside the scope of the present study). For field-classified 'recharge wells', there is a good agreement to the hydrochemistry-based (Piper plot) well classification, but less good for the field-classified 'discharge wells'. In addition, the concentration of the age-dating parameter tritium shows low variability among recharge wells, but a large spread among discharge

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

    Science.gov (United States)

    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.

  13. Plasma Kinetics in the Ethanol/Water/Air Mixture in "Tornado" Type Electrical Discharge

    CERN Document Server

    Levko, D; Chernyak, V; Olszewski, S; Nedybaliuk, O

    2011-01-01

    This paper presents the results of a theoretical and experimental study of plasma-assisted reforming of ethanol into molecular hydrogen in a new modification of the "tornado" type electrical discharge. Numerical modeling clarifies the nature of the non-thermal conversion and explains the kinetic mechanism of nonequilibrium plasma-chemical transformations in the gas-liquid system and the evolution of hydrogen during the reforming as a function of discharge parameters and ethanol-to-water ratio in the mixture. We also propose a scheme of chemical reactions for plasma kinetics description. It is shown that some characteristics of the investigated reactor are at least not inferior to characteristics of other plasma chemical reactors.

  14. Comparative study of NO removal in surface-plasma and volume-plasma reactors based on pulsed corona discharges.

    Science.gov (United States)

    Malik, Muhammad Arif; Kolb, Juergen F; Sun, Yaohong; Schoenbach, Karl H

    2011-12-15

    Nitric oxide (NO) conversion has been studied for two different types of atmospheric-pressure pulsed-corona discharges, one generates a surface-plasma and the other provides a volume-plasma. For both types of discharges the energy cost for NO removal increases with decreasing oxygen concentration and initial concentration of NO. However, the energy cost for volume plasmas for 50% NO removal, EC(50), from air was found to be 120 eV/molecule, whereas for the surface plasma, it was only 70 eV/molecule. A smaller difference in energy cost, but a higher efficiency for removal of NO was obtained in a pure nitrogen atmosphere, where NO formation is restricted due to the lack of oxygen. For the volume plasma, EC(50) in this case was measured at 50 eV/molecule, and for the surface plasma it was 40 eV/molecule. Besides the higher NO removal efficiency of surface plasmas compared to volume plasmas, the energy efficiency of surface-plasmas was found to be almost independent of the amount of electrical energy deposited in the discharge, whereas the efficiency for volume plasmas decreases considerably with increasing energy. This indicates the possibility of operating surface plasma discharges at high energy densities and in more compact reactors than conventional volume discharges.

  15. Comparative study of NO removal in surface-plasma and volume-plasma reactors based on pulsed corona discharges

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Muhammad Arif, E-mail: MArifMalik@gmail.com [Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA 23508 (United States); Kolb, Juergen F.; Sun, Yaohong; Schoenbach, Karl H. [Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA 23508 (United States)

    2011-12-15

    Nitric oxide (NO) conversion has been studied for two different types of atmospheric-pressure pulsed-corona discharges, one generates a surface-plasma and the other provides a volume-plasma. For both types of discharges the energy cost for NO removal increases with decreasing oxygen concentration and initial concentration of NO. However, the energy cost for volume plasmas for 50% NO removal, EC{sub 50}, from air was found to be 120 eV/molecule, whereas for the surface plasma, it was only 70 eV/molecule. A smaller difference in energy cost, but a higher efficiency for removal of NO was obtained in a pure nitrogen atmosphere, where NO formation is restricted due to the lack of oxygen. For the volume plasma, EC{sub 50} in this case was measured at 50 eV/molecule, and for the surface plasma it was 40 eV/molecule. Besides the higher NO removal efficiency of surface plasmas compared to volume plasmas, the energy efficiency of surface-plasmas was found to be almost independent of the amount of electrical energy deposited in the discharge, whereas the efficiency for volume plasmas decreases considerably with increasing energy. This indicates the possibility of operating surface plasma discharges at high energy densities and in more compact reactors than conventional volume discharges.

  16. Surface Cleaning by Glow Discharge in High-Volume Gas Flow

    Science.gov (United States)

    1976-04-07

    was used with a #25 size hypodermic needle the results are shown in Table 2. A slightly smaller drop was obtained when using the same size needle coated...small to measure, indicates a surface free of both water and of substances which are hydrophobic. The theory of the significance of the small contact...and its diameter when spread out over the surface of the clean specimen. The experiment data to test the following theory , was accumulated by measuring

  17. Discharge of surplus phloem water may be required for normal grape ripening.

    Science.gov (United States)

    Zhang, Yun; Keller, Markus

    2017-01-01

    At the onset of ripening, some fleshy fruits shift the dominant water import pathway from the xylem to the phloem, but the cause for the decline in xylem inflow remains obscure. This study found that xylem-mobile dye movement into grape berries decreased despite transient increases in berry growth and transpiration during early ripening, whereas outward dye movement continued unless the roots were pressurized. Modeling berry vascular flows using measurements of pedicel phloem sap sugar concentration, berry growth, solute accumulation, and transpiration showed that a fraction of phloem-derived water was used for berry growth and transpiration; the surplus was recirculated via the xylem. Changing phloem sap sugar concentration to a much higher published value led to model simulations predicting xylem inflow or backflow depending on the developmental stage and genotype. Mathematically preventing net xylem flow resulted in large variations in phloem sap sugar concentration in pedicels serving neighboring berries on the same fruit cluster. Moreover, restricting water discharge via the xylem and/or across the skin impaired berry solute accumulation and color change. Collectively, these results indicate that discharge of surplus phloem water via berry transpiration and/or xylem backflow may be necessary to facilitate normal grape ripening. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  18. Luminous phase of nanosecond discharge in deionized water: morphology, propagation velocity and optical emission

    Science.gov (United States)

    Šimek, Milan; Pongrác, Branislav; Babický, Václav; Člupek, Martin; Lukeš, Petr

    2017-07-01

    We employed the techniques of time-resolved intensified charge-coupled device (ICCD) microscopy and spectroscopy to register basic morphologic and emission fingerprints of micro-discharges produced in deionized water. Fast rise-time positive high-voltage pulses (full width at half maximum of ˜7 ns and amplitude of ˜100 kV) in a point-to-plane electrode geometry produced micro-discharges, either periodically or in a single-pulse regime with the energy of ˜0.1 J dissipated during a single discharge event. Time resolved ICCD images evidence typical streamer-like branched filamentary morphology. Luminous discharge filaments show very fast and approximately linear initial expansion of the length with propagation velocity of ˜2 × 105 m s-1. When the HV pulse reaches its maximum value, the length of the primary luminous filaments reaches ˜1.3 mm. After initial expansion, the length of luminous filaments collapses and can be characterised by velocity of ˜1.9 × 104 m s-1. The first collapse is followed by a second slightly slower expansion, which is driven by the arrival of a reflected HV pulse, and which can be roughly approximated by propagation velocity of ˜1.5 × 105 m s-1. The second collapse (occurring after second expansion) proceeds at a nearly identical velocity compared with the first one. By combining two ICCD based techniques, we have been able to associate, for the first time ever, characteristic emission spectra with the most important phases of the micro-discharge development. The UV-vis-NIR emission spectra show a broad-band continuum evolving during the first expansion and collapse, followed by the well-known HI/OI atomic lines occurring together with continuum emission during the second expansion and collapse. We conclude that bound-free and free-free radiative transitions are basic emission characteristics of the nanosecond discharge initiation mechanism in liquid water which does not involve the formation of vapour bubbles.

  19. Electrolysis of water on (oxidized) metal surfaces

    DEFF Research Database (Denmark)

    Rossmeisl, Jan; Logadottir, Ashildur; Nørskov, Jens Kehlet

    2005-01-01

    directly from the electronic structure calculations. We consider electrodes of Pt(111) and Au(111) in detail and then discuss trends for a series of different metals. We show that the difficult step in the water splitting process is the formation of superoxy-type (OOH) species on the surface...... by the splitting of a water molecule on top an adsorbed oxygen atom. One conclusion is that this is only possible on metal surfaces that are (partly) oxidized. We show that the binding energies of the different intermediates are linearly correlated for a number of metals. In a simple analysis, where the linear...... relations are assumed to be obeyed exactly, this leads to a universal relationship between the catalytic rate and the oxygen binding energy. Finally, we conclude that for systems obeying these relations, there is a limit to how good a water splitting catalyst an oxidized metal surface can become. (c) 2005...

  20. Index of surface-water stations in Texas, January 1987

    Science.gov (United States)

    Rawson, Jack; Carrillo, E.R.; Buckner, H.D.

    1987-01-01

    As of January 1, 1987, the surface-water data-collection network in Texas included 376 continuous streamflow, 76 continuous or daily reservoir-content, 34 gage height, 16 crest-stage partial-record, 8 periodic discharge through range, 33 floodhydrograph partial-record, 9 flood-profile partial-record, 36 low-flow partial-record, 46 daily chemical-quality, 19 continuous-recording water-quality, 84 periodic biological, 17 lake surveys, 162 periodic organic and (or) nutrient, 3 periodic insecticide, 42 periodic pesticide, 19 automatic sampler, 141 periodic minor elements, 130 periodic chemical-quality, 78 periodic physical-organic, 22 continuous-recording three- or four-parameter water-quality, 34 periodic sediment, 22 continuous-recording temperature, and 30 national stream-quality accounting network stations. Plate 1 shows the location of surface-water streamflow or reservoir-content and chemical-quality or sediment'stations in Texas. Plate 2 shows the location of partial-record surfacewater stations.

  1. Effects of rf power on chemical composition and surface roughness of glow discharge polymer films

    Science.gov (United States)

    Zhang, Ling; He, Xiaoshan; Chen, Guo; Wang, Tao; Tang, Yongjian; He, Zhibing

    2016-03-01

    The glow discharge polymer (GDP) films for laser fusion targets were successfully fabricated by plasma enhanced chemical vapor deposition (PECVD) at different radio frequency (rf) powers. The films were deposited using trans-2-butene (T2B) mixed with hydrogen as gas sources. The composition and state of plasma were diagnosed by quadrupole mass spectrometer (QMS) and Langmuir probe during the deposition process. The composition, surface morphology and roughness were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and white-light interferometer (WLI), respectively. Based on these observation and analyses, the growth mechanism of defects in GDP films were studied. The results show that, at low rf power, there is a larger probability for secondary polymerization and formation of multi-carbon C-H species in the plasma. In this case, the surface of GDP film turns to be cauliflower-like. With the increase of rf power, the degree of ionization is high, the relative concentration of smaller-mass hydrocarbon species increases, while the relative concentration of larger-mass hydrocarbon species decreases. At higher rf power, the energy of smaller-mass species are high and the etching effects are strong correspondingly. The GDP film's surface roughness shows a trend of decrease firstly and then increase with the increasing rf power. At rf power of 30 W, the surface root-mean-square roughness (Rq) drops to the lowest value of 12.8 nm, and no "void" defect was observed.

  2. A Review on overboard CEOR discharged produced water treatment and remediation

    Science.gov (United States)

    Rawindran, H.; Krishnan, S.; Sinnathambi, C. M.

    2017-06-01

    Produced water is a waste by-product generated during oil and gas recovery operations. It contains the mixture of organic and inorganic compounds. Produced water management is a challenge faced by the petroleum practitioners worldwide. Build-up of chemical wastes from produced water causes huge footprint, which results in high CapEx and OpEx. Different technologies are practiced by various practitioners to treat the produced waste water. However, the constituents removed by each technology and the degree of organic compound removal has to be considered to identify the potential and effective treatment technologies for offshore industrial applications. Current produced water technologies and their successful applications have advantages and disadvantages and can be ranked on the basis of several factors, such as their discharge limit into water bodies, reinjection in producing well, or for any miscellaneous beneficial use. This paper attempts to provide a review of existing physical and chemical treatment technologies used for management of produced water. Based on our analysis, suitable methods will be recommended for offshore waste water treatment technologies.

  3. Potential effects of groundwater pumping on water levels, phreatophytes, and spring discharges in Spring and Snake Valleys, White Pine County, Nevada, and adjacent areas in Nevada and Utah

    Science.gov (United States)

    Halford, Keith J.; Plume, Russell W.

    2011-01-01

    Assessing hydrologic effects of developing groundwater supplies in Snake Valley required numerical, groundwater-flow models to estimate the timing and magnitude of capture from streams, springs, wetlands, and phreatophytes. Estimating general water-table decline also required groundwater simulation. The hydraulic conductivity of basin fill and transmissivity of basement-rock distributions in Spring and Snake Valleys were refined by calibrating a steady state, three-dimensional, MODFLOW model of the carbonate-rock province to predevelopment conditions. Hydraulic properties and boundary conditions were defined primarily from the Regional Aquifer-System Analysis (RASA) model except in Spring and Snake Valleys. This locally refined model was referred to as the Great Basin National Park calibration (GBNP-C) model. Groundwater discharges from phreatophyte areas and springs in Spring and Snake Valleys were simulated as specified discharges in the GBNP-C model. These discharges equaled mapped rates and measured discharges, respectively. Recharge, hydraulic conductivity, and transmissivity were distributed throughout Spring and Snake Valleys with pilot points and interpolated to model cells with kriging in geologically similar areas. Transmissivity of the basement rocks was estimated because thickness is correlated poorly with transmissivity. Transmissivity estimates were constrained by aquifer-test results in basin-fill and carbonate-rock aquifers. Recharge, hydraulic conductivity, and transmissivity distributions of the GBNP-C model were estimated by minimizing a weighted composite, sum-of-squares objective function that included measurement and Tikhonov regularization observations. Tikhonov regularization observations were equations that defined preferred relations between the pilot points. Measured water levels, water levels that were simulated with RASA, depth-to-water beneath distributed groundwater and spring discharges, land-surface altitudes, spring discharge at

  4. Ground-Water, Surface-Water, and Water-Chemistry Data, Black Mesa Area, Northeastern Arizona - 2006-07

    Science.gov (United States)

    Truini, Margot; Macy, J.P.

    2008-01-01

    The N aquifer is the major source of water in the 5,400 square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in northeastern Arizona because of continued water requirements for industrial and municipal use and the needs of a growing population. Precipitation in the Black Mesa area is typically about 6 to 14 inches per year. The water-monitoring program in the Black Mesa area began in 1971 and is designed to provide information about the long-term effects of ground-water withdrawals from the N aquifer for industrial and municipal uses. This report presents results of data collected for the monitoring program in the Black Mesa area from January 2006 to September 2007. The monitoring program includes measurements of (1) ground-water withdrawals, (2) ground-water levels, (3) spring discharge, (4) surface-water discharge, and (5) ground-water chemistry. Periodic testing of ground-water withdrawal meters is completed every 4 to 5 years. The Navajo Tribal Utility Authority (NTUA) yearly totals for the ground-water metered withdrawal data were unavailable in 2006 due to an up-grade within the NTUA computer network. Because NTUA data is often combined with Bureau of Indian Affairs data for the total withdrawals in a well system, withdrawals will not be published in this year's annual report. From 2006 to 2007, annually measured water levels in the Black Mesa area declined in 3 of 11 wells measured in the unconfined areas of the N aquifer, and the median change was 0.0 feet. Measurements indicated that water levels declined in 8 of 17 wells measured in the confined area of the aquifer. The median change for the confined area of the aquifer was 0.2 feet. From the prestress period (prior to 1965) to 2007, the median water-level change for 30 wells was -11.1 feet. Median water-level changes were 2.9 feet for 11 wells measured in the unconfined areas and -40.2 feet for 19 wells measured in the confined area. Spring flow was measured

  5. A mathematical model for surface roughness of fluidic channels produced by grinding aided electrochemical discharge machining (G-ECDM

    Directory of Open Access Journals (Sweden)

    Ladeesh V. G.

    2017-01-01

    Full Text Available Grinding aided electrochemical discharge machining is a hybrid technique, which combines the grinding action of an abrasive tool and thermal effects of electrochemical discharges to remove material from the workpiece for producing complex contours. The present study focuses on developing fluidic channels on borosilicate glass using G-ECDM and attempts to develop a mathematical model for surface roughness of the machined channel. Preliminary experiments are conducted to study the effect of machining parameters on surface roughness. Voltage, duty factor, frequency and tool feed rate are identified as the significant factors for controlling surface roughness of the channels produced by G-ECDM. A mathematical model was developed for surface roughness by considering the grinding action and thermal effects of electrochemical discharges in material removal. Experiments are conducted to validate the model and the results obtained are in good agreement with that predicted by the model.

  6. Surface Modification of Water Purification Membranes.

    Science.gov (United States)

    Miller, Daniel J; Dreyer, Daniel R; Bielawski, Christopher W; Paul, Donald R; Freeman, Benny D

    2017-04-18

    Polymeric membranes are an energy-efficient means of purifying water, but they suffer from fouling during filtration. Modification of the membrane surface is one route to mitigating membrane fouling, as it helps to maintain high levels of water productivity. Here, a series of common techniques for modification of the membrane surface are reviewed, including surface coating, grafting, and various treatment techniques such as chemical treatment, UV irradiation, and plasma treatment. Historical background on membrane development and surface modification is also provided. Finally, polydopamine, an emerging material that can be easily deposited onto a wide variety of substrates, is discussed within the context of membrane modification. A brief summary of the chemistry of polydopamine, particularly as it may pertain to membrane development, is also described. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Surface Water Protection by Productive Buffers

    DEFF Research Database (Denmark)

    Christen, Benjamin

    Vegetated riparian buffer zones are a widely recommended best management practice in agriculture for protecting surface and coastal waters from diffuse nutrient pollution. On the background of the EU funded research project NitroEurope (NEU; www.NitroEurope.eu), this study concentrates...... on the mitigation of nitrogen pollution in surface and groundwater, using riparian buffer zones for biomass production. The objectives are to map suitable areas for buffer implementation across the six NEU study landscapes, model tentative N-loss mitigation, calculate biomass production potential and economic...... designed for local conditions could be a way of protecting water quality attractive to many stakeholders....

  8. Does zero-water discharged technology enhance culture performance of pacific white shrimp (Litopenaeus vannamei Boone.)?

    Science.gov (United States)

    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 (Pculture 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/L which is significantly

  9. Surface-water quality assessment of the Clover Creek basin, Pierce County, Washington, 1991-1992

    Science.gov (United States)

    McCarthy, K.A.

    1996-01-01

    Increasing urbanization in the 67-square-mile Clover Creek Basin has generated interest in the effects of land-use changes on local water quality. To investigate these effects, water-quality and streamflow data were collected from 19 surface-water sites in the basin over a 16-month period from January 1991 through April 1992. These data were used to understand the effects of surficial geology, land-use practices, and wastewater disposal practices on surface-water quality within the basin. The basin was divided into four drainage subbasins with dissimilar hydrogeologic, land-use, and water-quality characteristics. In the Upper Clover Creek subbasin, the high permeability of surficial geologic materials promotes infiltration of precipitation to ground water and thus attenuates the response of streams to rainfall. Significant interaction occurs between surface and ground water in this subbasin, and nitrate concentrations and specific conductance values, similar to those found historically in local ground water, indicate that sources such as subsurface waste-disposal systems and fertilizers are affecting surface- water quality in this area. In the Spanaway subbasin, the presence of Spanaway and Tule Lakes affects water quality, primarily because of the reduced velocity and long residence time of water in the lakes. Reduced water velocity and long residence times (1) cause settling of suspended materials, thereby reducing concentrations of suspended sediment and constituents that are bound to the sediment; (2) promote biological activity, which tends to trap nutrients in the lakes; and (3) allow dispersion to attenuate peaks in discharge and water-quality constituent concentrations. In the North Fork subbasin, the low permeability of surficial geologic materials and areas of intensive land development inhibit infiltration of precipitation and thus promote surface runoff to streams. Surface pathways provide little attenuation of storm runoff and result in rapid increases

  10. A mathematical model for surface roughness of fluidic channels produced by grinding aided electrochemical discharge machining (G-ECDM)

    OpenAIRE

    Ladeesh V. G.; Manu R

    2017-01-01

    Grinding aided electrochemical discharge machining is a hybrid technique, which combines the grinding action of an abrasive tool and thermal effects of electrochemical discharges to remove material from the workpiece for producing complex contours. The present study focuses on developing fluidic channels on borosilicate glass using G-ECDM and attempts to develop a mathematical model for surface roughness of the machined channel. Preliminary experiments are conducted to study the effect of mac...

  11. An exact calculation of the N2+ and H2+ influx at cathode surface in N2-H2 discharges

    Science.gov (United States)

    Suraj, K. S.; Alex, Prince

    An exact calculation of N2+ and H2+ influx, at cathode surface in N2-H2 discharge, has been derived using electron impact ionization cross-section at plasma sheath boundary. The analytical formula is very convenient in practical applications. Through the analysis of experimental parameters for glow discharge plasma nitriding, the formula explains, why treatment in an N2-H2 mixture with H2 percentage ∼70% gives most enhanced result.

  12. Application of a pulse-discharge helium detector to the determination of neon in air and water.

    Science.gov (United States)

    Lasa, J; Mochalski, P; Lokas, E; Kedzior, L

    2002-08-30

    A pulse-discharge helium detector (Valco, PD-D2-I) is used to measure neon concentrations in air and water. The detection level is 0.5 x 10(-8) g/cm3 (0.2 ppm). Discharge gas doped with neon results in a linear response to the neon mass up to 10(-6) g. For measuring the neon concentration in water, a simple enrichment system is used.

  13. Effects of rf power on chemical composition and surface roughness of glow discharge polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ling; He, Xiaoshan; Chen, Guo; Wang, Tao; Tang, Yongjian; He, Zhibing, E-mail: hezhibing802@163.com

    2016-03-15

    Graphical abstract: - Highlights: • The growth mechanism of defects in GDP films was studied upon plasma diagnosis. • Increasing rf power enhanced the etching effects of smaller-mass species. • The “void” defect was caused by high energy hydrocarbons bombardment on the surface. • The surface roughness was only 12.76 nm, and no “void” defect was observed at 30 W. - Abstract: The glow discharge polymer (GDP) films for laser fusion targets were successfully fabricated by plasma enhanced chemical vapor deposition (PECVD) at different radio frequency (rf) powers. The films were deposited using trans-2-butene (T{sub 2}B) mixed with hydrogen as gas sources. The composition and state of plasma were diagnosed by quadrupole mass spectrometer (QMS) and Langmuir probe during the deposition process. The composition, surface morphology and roughness were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and white-light interferometer (WLI), respectively. Based on these observation and analyses, the growth mechanism of defects in GDP films were studied. The results show that, at low rf power, there is a larger probability for secondary polymerization and formation of multi-carbon C-H species in the plasma. In this case, the surface of GDP film turns to be cauliflower-like. With the increase of rf power, the degree of ionization is high, the relative concentration of smaller-mass hydrocarbon species increases, while the relative concentration of larger-mass hydrocarbon species decreases. At higher rf power, the energy of smaller-mass species are high and the etching effects are strong correspondingly. The GDP film's surface roughness shows a trend of decrease firstly and then increase with the increasing rf power. At rf power of 30 W, the surface root-mean-square roughness (Rq) drops to the lowest value of 12.8 nm, and no “void” defect was observed.

  14. Surface oxygen micropatterns on glow discharge polymer targets by photo irradiation

    Science.gov (United States)

    Reynolds, Hannah; Baxamusa, Salmaan; Haan, Steven W.; Fitzsimmons, Paul; Carlson, Lane; Farrell, Mike; Nikroo, Abbas; Watson, Brian J.

    2016-02-01

    Recent simulations predict surface oxygen may be a significant source of disruptive perturbations in the implosion process of glow-discharge polymers (GDP) ablators at the National Ignition Facility. GDP material held in ambient atmospheric conditions showed an increase in mass when stored in light transparent containers, which suggests that photo exposure is a driving force for oxygen absorption. To investigate if surface oxygen is a contributing factor of disruptive perturbations during implosion, a method to imprint a periodic micropattern of oxygen on the surface of GDP was developed and used to fabricate a flat sample for empirical testing. Photo exposure using collimated blue light was used to generate micropatterns of surface oxygen on the GDP material. The periodic oxygen micropattern was confirmed by secondary ion mass spectrometry (SIMS) and energy dispersive spectroscopy. A SIMS depth profile showed the atomic percent of oxygen ranged from 8 at. % near the surface to 1 at. % at a depth of 2 μm in a sample exposed for 4 min. The molecular interactions formed between the GDP and oxygen molecules were characterized using Fourier transform infrared resonance (FTIR), which showed the formation of hydroxyl (O-H) and carbonyl (C=O) bonds. The FTIR enabled the oxygen mass uptake as a function of photo exposure time to be quantified (resolved to typically 0.05 at. % oxygen). This experimental protocol was then applied to produce a GDP flat part with a periodic 75 μm wavelength micropattern of photo exposed (oxygen rich) and masked (oxygen deficient) regions. The micropatterned GDP ablators developed in this work are being used to assess the effect of surface oxygen on disruptive perturbations during the inertial confinement fusion implosion process.

  15. Ultra Water Repellent Polypropylene Surfaces with Tunable Water Adhesion.

    Science.gov (United States)

    Zhu, Tang; Cai, Chao; Guo, Jing; Wang, Rong; Zhao, Ning; Xu, Jian

    2017-03-22

    Polypropylene (PP), including isotactic PP (i-PP) and atactic PP (a-PP) with distinct tacticity, is one of the most widely used general plastics. Herein, ultra water repellent PP coatings with tunable adhesion to water were prepared via a simple casting method. The pure i-PP coating shows a hierarchical morphology with micro/nanobinary structures, exhibiting a water contact angle (CA) larger than 150° and a sliding angle less than 5° (for 5 μL water droplet). In contrast, the pure a-PP coating has a less rough morphology with a water contact angle of about 130°, and the water droplets stick on the coating at any tilted angles. For the composite i-PP/a-PP coatings, however, ultra water repellency with CA > 150° but water adhesion tailorable from slippery to sticky can be realized, depending on the contents of a-PP and i-PP. The different wetting behaviors are due to the various microstructures of the composite coatings resulting from the distinct crystallization ability of a-PP and i-PP. Furthermore, the existence of a-PP in the composite coatings enhances the mechanical properties compared to the i-PP coating. The proposed method is feasible to modify various substrates and potential applications in no-loss liquid transportation, slippery surfaces, and patterned superhydrophobic surfaces are demonstrated.

  16. Cold atmospheric plasma discharged in water and its potential use in cancer therapy

    Science.gov (United States)

    Chen, Zhitong; Cheng, Xiaoqian; Lin, Li; Keidar, Michael

    2017-01-01

    Cold atmospheric plasma (CAP) has emerged as a novel technology for cancer treatment. CAP can directly treat cells and tissue but such direct application is limited to skin or can be invoked as a supplement during open surgery. In this study we report indirect plasma treatment using CAP discharged in deionized (DI) water using three gases as carriers (argon (Ar), helium (He), and nitrogen (N2)). Plasma stimulated water was applied to the human breast cancer cell line (MDA-MB-231). MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay tests showed that using Ar plasma had the strongest effect on inducing apoptosis in cultured human breast cancer cells. This result is attributed to the elevated production of reactive oxygen species and reactive nitrogen species in water.

  17. Low pressure water vapour discharge as a light source: II. Electrical characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Artamonova, E; Artamonova, T; Beliaeva, A; Khodorkovskii, M; Melnikov, A; Milenin, V; Murashov, S; Rakcheeva, L; Timofeev, N [Saint Petersburg State University, Ulyanovskaya 3, Petrodvoretz, Saint Petersburg 198504 (Russian Federation); Michael, D [General Electric Global Research Center, One Research Circle (Bldg K1 Rm 4B31A), Niskayuna, NY 12309 (United States); Zissis, G, E-mail: timofeev@pobox.spbu.r, E-mail: michael@crd.ge.co, E-mail: georges.zissis@laplace.univ-tlse.f [Universite Toulouse 3-Paul Sabatier, LAPLACE Building 3R2, 118 rte de Narbonne, F-31062 Toulouse Cedex 9 (France)

    2009-09-07

    The electric field strength, electrode fall voltage, light emission characteristics and efficiency of a (Ar + H{sub 2}O) dc discharge as functions of water vapour content, argon pressure and electric current are presented. The data show that the main processes of 306.4 nm OH band generation are (1) a collision between an excited argon atom and a water molecule with simultaneous excitation of OH into the A {sup 2}{Sigma}{sup +} state and (2) electron excitation of a ground state hydroxyl molecule produced by a quenching process from a water molecule. Electric field strength measurements make it possible to conclude that the light production efficiency of the plasma under study can reach 35 lm W{sup -1}. It is possible, with these data, to propose a model of the plasma in question having reasonable accordance with the experiment and show the way to further increase the efficiency.

  18. How well Can We Classify SWOT-derived Water Surface Profiles?

    Science.gov (United States)

    Frasson, R. P. M.; Wei, R.; Picamilh, C.; Durand, M. T.

    2015-12-01

    The upcoming Surface Water Ocean Topography (SWOT) mission will detect water bodies and measure water surface elevation throughout the globe. Within its continental high resolution mask, SWOT is expected to deliver measurements of river width, water elevation and slope of rivers wider than ~50 m. The definition of river reaches is an integral step of the computation of discharge based on SWOT's observables. As poorly defined reaches can negatively affect the accuracy of discharge estimations, we seek strategies to break up rivers into physically meaningful sections. In the present work, we investigate how accurately we can classify water surface profiles based on simulated SWOT observations. We assume that most river sections can be classified as either M1 (mild slope, with depth larger than the normal depth), or A1 (adverse slope with depth larger than the critical depth). This assumption allows the classification to be based solely on the second derivative of water surface profiles, with convex profiles being classified as A1 and concave profiles as M1. We consider a HEC-RAS model of the Sacramento River as a representation of the true state of the river. We employ the SWOT instrument simulator to generate a synthetic pass of the river, which includes our best estimates of height measurement noise and geolocation errors. We process the resulting point cloud of water surface heights with the RiverObs package, which delineates the river center line and draws the water surface profile. Next, we identify inflection points in the water surface profile and classify the sections between the inflection points. Finally, we compare our limited classification of simulated SWOT-derived water surface profile to the "exact" classification of the modeled Sacramento River. With this exercise, we expect to determine if SWOT observations can be used to find inflection points in water surface profiles, which would bring knowledge of flow regimes into the definition of river reaches.

  19. Problems of mine waters discharge in the Samara River and its influence on biota of the ecosystem

    Directory of Open Access Journals (Sweden)

    V. M. Kochet

    2006-02-01

    Full Text Available On the basis of long-term studies of aquatic organisms’ reactions to mine waters the approximate estimation of the waters influence on theSamaraRiver’s ecosystems was performed. Modern variants of the waters discharge were analyzed. The most acceptable environmental and economic choice of mine pumping at the modern stage of coal mining is presented.

  20. Long-Term Temporal Variability of the Freshwater Discharge and Water Levels at Patos Lagoon, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    G. P. Barros

    2012-01-01

    Full Text Available The aim of this study is to investigate the importance of freshwater discharge as a physical forcing in Patos Lagoon at timescales longer than one year, as well as identify the temporal variability of the dominant processes in freshwater discharge and water levels along the Patos Lagoon. Due to its proximity to the mouth, the water level at the estuary is influenced by the remote effects associated with the adjacent ocean circulation and wave climatology, reducing the observed correlation. At the lagoonar region a high correlation is expected because interannual data is being used, reducing the influence of the wind. Cross wavelet technique is applied to examine the coherence and phase between interannual time-series (South Oscillation Index, freshwater discharge and water levels. The freshwater discharge of the main tributaries and water levels in Patos Lagoon are influenced by ENSO on interannual scales (cycles between 3.8 and 6 years. Therefore, El Niño events are associated with high mean values of freshwater discharge and water levels above the mean. On the other hand, La Niña events are associated with low mean values of freshwater discharge and water levels below the mean.

  1. Formation of radical and active chemical species in electrical discharge plasma in the presence of liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Locke, B.R.; Shih, K.Y.; Burlica, R. [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemical and Biomedical Engineering

    2010-07-01

    This study investigated the interactions of plasma with liquid water using a combination of emission spectroscopy of radical and atomic species and direct measurements of more stable chemical compounds. The study focused on electrical discharge plasma formed directly in liquid water and on discharges formed in the gas phase above liquid water, in bubbles in liquid water, and in the gas phase with water droplet spray that result in a variety of active chemical species that can be used for pollution control as well as other applications in biomedical and materials engineering. The purpose was to improve the design and operation of plasma reactors for a variety of applications. This presentation also reviewed the mechanisms for the formation of active chemical species such as hydroxyl and other radicals, hydrogen peroxide and molecular hydrogen, in electrical discharge plasma formed in the presence of water.

  2. Validation of a CFD model simulating charge and discharge of a small heat storage test module based on a sodium acetate water mixture

    DEFF Research Database (Denmark)

    Dannemand, Mark; Fan, Jianhua; Furbo, Simon;

    2014-01-01

    Experimental and theoretical investigations are carried out to study the heating of a 302 x 302 x 55 mm test box of steel containing a sodium acetate water mixture. A thermostatic bath has been set up to control the charging and discharging of the steel box. The charging and discharging has been...... the module starting with the salt water mixture in liquid phase from 72˚C to 95˚C; heating up the module from ambient temperature with the salt water mixture in solid phase, going through melting, ending in liquid phase at 78˚C/82˚C; and discharging the test module from liquid phase at 82˚C, going through...... investigated experimentally by measuring surface temperatures of the box as well as the internal temperature of the sodium acetate water mixture through a probe located in the center of the steel box. The temperature developments on the outer surfaces of the steel box are used as input parameters...

  3. Predicted impacts from offshore produced water discharges on hypoxia in the Gulf of Mexico.

    Energy Technology Data Exchange (ETDEWEB)

    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

  4. Ozone correlates with antibacterial effects from indirect air dielectric barrier discharge treatment of water

    Science.gov (United States)

    Pavlovich, Matthew J.; Chang, Hung-Wen; Sakiyama, Yukinori; Clark, Douglas S.; Graves, David B.

    2013-04-01

    Ambient-condition air plasma produced by indirect dielectric barrier discharges can rapidly disinfect aqueous solutions contaminated with bacteria and other microorganisms. In this study, we measured key chemical species in plasma-treated aqueous solutions and the associated antimicrobial effect for varying discharge power densities, exposure times, and buffer components in the aqueous medium. The aqueous chemistry corresponded to air plasma chemistry, and we observed a transition in composition from ozone mode to nitrogen oxides mode as the discharge power density increased. The inactivation of E. coli correlates well with the aqueous-phase ozone concentration, suggesting that ozone is the dominant species for bacterial inactivation under these conditions. Published values of ozone-water antibacterial inactivation kinetics as a function of the product of ozone concentration and contact time are consistent with our results. In contrast to earlier studies of plasma-treated water disinfection, ozone-dependent bacterial inactivation does not require acidification of the aqueous medium and the bacterial inactivation rates are far higher. Furthermore, we show that the antimicrobial effect depends strongly on gas-liquid mixing following plasma treatment, apparently because of the low solubility of ozone and the slow rate of mass transfer from the gas phase to the liquid. Without thorough mixing of the ozone-containing gas and bacteria-laden water, the antimicrobial effect will not be observed. However, it should be recognized that the complexity of atmospheric pressure plasma devices, and their sensitivity to subtle differences in design and operation, can lead to different results with different mechanisms.

  5. EXPERIMENTAL STUDY ON CAVITATION AND WATER-WING FOR MIDDLE-PIERS OF DISCHARGE TUNNELS

    Institute of Scientific and Technical Information of China (English)

    WU Jian-hua; CAI Chang-guang; JI Wei; RUAN Shi-ping; LUO Chao

    2005-01-01

    In construction of high dams, design of a middle-pier, placed in a discharge tunnel to divide it into two parts, is a better choice that could breakthrough the limits of the manufacture and operation of the gate due to the high head to it. However, cavitation and water-wing, a kind of flow striking the top and side walls of the tunnel, induced by the middle-pier, may take place and bring about bad effects on operation of the tunnel. The experiments of the six comparing plans were conducted, consisting of atmospheric and vacuum tank models, and the interesting areas included relationships between discharges and reservoir levels, measurements of side wall pressures, comparisons of water-wing states for the various middle-piers, estimations of the incipient cavitation numbers and the flow cavitation numbers, and analyses of cavitation characteristics for the tunnel. A kind of new bodily form of middle-pier was developed. Water-wing states were better improved and non-cavitation conditions were satisfied.

  6. Global modelling of Cryptosporidium in surface water

    Science.gov (United States)

    Vermeulen, Lucie; Hofstra, Nynke

    2016-04-01

    Introduction Waterborne pathogens that cause diarrhoea, such as Cryptosporidium, pose a health risk all over the world. In many regions quantitative information on pathogens in surface water is unavailable. Our main objective is to model Cryptosporidium concentrations in surface waters worldwide. We present the GloWPa-Crypto model and use the model in a scenario analysis. A first exploration of global Cryptosporidium emissions to surface waters has been published by Hofstra et al. (2013). Further work has focused on modelling emissions of Cryptosporidium and Rotavirus to surface waters from human sources (Vermeulen et al 2015, Kiulia et al 2015). A global waterborne pathogen model can provide valuable insights by (1) providing quantitative information on pathogen levels in data-sparse regions, (2) identifying pathogen hotspots, (3) enabling future projections under global change scenarios and (4) supporting decision making. Material and Methods GloWPa-Crypto runs on a monthly time step and represents conditions for approximately the year 2010. The spatial resolution is a 0.5 x 0.5 degree latitude x longitude grid for the world. We use livestock maps (http://livestock.geo-wiki.org/) combined with literature estimates to calculate spatially explicit livestock Cryptosporidium emissions. For human Cryptosporidium emissions, we use UN population estimates, the WHO/UNICEF JMP sanitation country data and literature estimates of wastewater treatment. We combine our emissions model with a river routing model and data from the VIC hydrological model (http://vic.readthedocs.org/en/master/) to calculate concentrations in surface water. Cryptosporidium survival during transport depends on UV radiation and water temperature. We explore pathogen emissions and concentrations in 2050 with the new Shared Socio-economic Pathways (SSPs) 1 and 3. These scenarios describe plausible future trends in demographics, economic development and the degree of global integration. Results and

  7. Surface Coating Constraint Induced Self-Discharging of Silicon Nanoparticles as Anodes for Lithium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Langli; Zhao, Peng; Yang, Hui; Liu, Borui; Zhang, Jiguang; Cui, Yi; Yu, Guihua; Zhang, Sulin; Wang, Chong M.

    2015-10-01

    One of the key challenges of Si-based anodes for lithium ion batteries is the large volume change upon lithiation and delithiation, which commonly leads to electrochemo-mechanical degradation and subsequent fast capacity fading. Recent studies have shown that applying nanometer-thick coating layers on Si nanoparticle (SiNPs) enhances cyclability and capacity retention. However, it is far from clear how the coating layer function from the point of view of both surface chemistry and electrochemo-mechanical effect. Herein, we use in situ transmission electron microscopy to investigate the lithiation/delithiation kinetics of SiNPs coated with a conductive polymer, polypyrrole (PPy). We discovered that this coating layer can lead to “self-delithiation” or “self-discharging” at different stages of lithiation. We rationalized that the self-discharging is driven by the internal compressive stress generated inside the lithiated SiNPs due to the constraint effect of the coating layer. We also noticed that the critical size of lithiation-induced fracture of SiNPs is increased from ~ 150 nm for bare SiNPs to ~ 380 nm for the PPy-coated SiNPs, showing a mechanically protective role of the coating layer. These observations demonstrate both beneficial and detrimental roles of the surface coatings, shedding light on rational design of surface coatings for silicon to retain high-power and high capacity as anode for lithium ion batteries.

  8. Surface-dependent inactivation of model microorganisms with shielded sliding plasma discharges and applied air flow.

    Science.gov (United States)

    Edelblute, Chelsea M; Malik, Muhammad A; Heller, Loree C

    2015-06-01

    Cold atmospheric plasma inactivates bacteria through reactive species produced from the applied gas. The use of cold plasma clinically has gained recent interest, as the need for alternative or supplementary strategies are necessary for preventing multi-drug resistant infections. The purpose of this study was to evaluate the antibacterial efficacy of a novel shielded sliding discharge based cold plasma reactor operated by nanosecond voltage pulses in atmospheric air on both biotic and inanimate surfaces. Bacterial inactivation was determined by direct quantification of colony forming units. The plasma activated air (afterglow) was bactericidal against Escherichia coli and Staphylococcus epidermidis seeded on culture media, laminate, and linoleum vinyl. In general, E. coli was more susceptible to plasma exposure. A bacterial reduction was observed with the application of air alone on a laminate surface. Whole-cell real-time PCR revealed a decrease in the presence of E. coli genomic DNA on exposed samples. These findings suggest that plasma-induced bacterial inactivation is surface-dependent.

  9. Product surface hardening in non-self-sustained glow discharge plasma before synthesis of superhard coatings

    Science.gov (United States)

    Krasnov, P. S.; Metel, A. S.; Nay, H. A.

    2017-05-01

    Before the synthesis of superhard coating, the product surface is hardened by means of plasma nitriding, which prevents the surface deformations and the coating brittle rupture. The product heating by ions accelerated from plasma by applied to the product bias voltage leads to overheating and blunting of the product sharp edges. To prevent the blunting, it is proposed to heat the products with a broad beam of fast nitrogen molecules. The beam injection into a working vacuum chamber results in filling of the chamber with quite homogeneous plasma suitable for nitriding. Immersion in the plasma of the electrode and heightening of its potential up to 50-100 V initiate a non-self-sustained glow discharge between the electrode and the chamber. It enhances the plasma density by an order of magnitude and reduces its spatial nonuniformity down to 5-10%. When a cutting tool is isolated from the chamber, it is bombarded by plasma ions with an energy corresponding to its floating potential, which is lower than the sputtering threshold. Hence, the sharp edges are sputtered only by fast nitrogen molecules with the same rate as other parts of the tool surface. This leads to sharpening of the cutting tools instead of blunting.

  10. Modeling oxygen depletion forced by acetate discharge in the coastal waters of the North Sea

    Science.gov (United States)

    Ilinskaya, Alisa; Yakushev, Evgeny; Nøst, Ole-Anders; Pakhomova, Svetlana

    2017-04-01

    Consequences of discharge of acetate produced during the production of X-ray contrast agents in the coastal waters of the Norwegian coast of the North Sea were analyzed with a set of mathematical models. The baseline seasonal variability of temperature, salinity, advection and turbulence were calculated with the Finite Volume Community Ocean Model (FVCOM) applied to the Southern coast of Norway. These data were used to force a vertical 2-Dimensional Benthic-Pelagic transport model (2DBP) coupled via Framework for Aquatic Biogeochemical Models (FABM) with a biogeochemical model OxyDep, considering phytoplankton, heterotrophs, nutrient, dissolved organic matter, particulate organic matter, and dissolved oxygen (DO). Acetate was considered as a chemical oxygen depletion substrate leading to the decrease of oxygen concentrations. We simulated seasonal variability at a 10 km long vertical transect with a spatial resolution of 50 m horizontally and approximately 2 m vertically. These calculations reproduced local minimum in the vertical DO distributions in 2 km distance from the discharge point, that corresponded to the observations. We conducted numerical experiments on the effects of doubling of the acetate discharge and on formation of acetate complexes.

  11. Using unsteady-state water level data to estimate channel roughness and discharge hydrograph

    Science.gov (United States)

    Aricò, Costanza; Nasello, Carmelo; Tucciarelli, Tullio

    2009-08-01

    A novel methodology for simultaneous discharge and channel roughness estimation is developed and applied to data sets available at three experimental sites. The methodology is based on the synchronous measurement of water level data in two river sections far some kilometers from each other, as well as on the use of a diffusive flow routing solver and does not require any direct velocity measurement. The methodology is first analyzed for the simplest case of a channel with a large slope, where the kinematic assumption holds. A sensitivity and a model error analysis are carried out in this hypothesis in order to show the stability of the results with respect to the error in the input parameters in the case of homogeneous roughness and to analyze the effect of unknown roughness heterogeneity on the estimated discharges. The methodology is then extended to the more general case of channels with mild slope and validated using field data previously collected in three Italian rivers: the Arno (in Tuscany), the Tiber (in Latium) and the Vallo di Diana, a small tributary of the Tanagro river (in Southern Italy). The performance of the proposed algorithm has been investigated according to three performance criteria estimating the quality of the match between the measured and the computed stage and discharge hydrographs. Results of the field tests can be considered good, despite the uncertainties of the field data and of the measured values.

  12. Transient analysis of water slug discharge in PWR safety/relief valve piping. [WATSLUG code

    Energy Technology Data Exchange (ETDEWEB)

    Van Duyne, D.A.; Hsieh, J.S.; Shave, D.F.

    1981-01-01

    The sudden discharge of the water loop seal, which is often present upsteam of pressurizer safety and relief valves, creates large momentum and inertia forces on the piping segments downstream of the valve. This paper provides a brief discussion of the commonly available control-volume calculation techniques, a description of the governing equations and a recently developed computer routine (WATSLUG) for their solution, and a review of results calculated using this method for a typical pressurizer safety and relief valve system. 8 refs.

  13. The effect of purified sewage discharge from a sewage treatment plant on the physicochemical state of water in the receiver

    Directory of Open Access Journals (Sweden)

    Kanownik Włodzimierz

    2016-09-01

    Full Text Available The paper presents changes in the contents of physicochemical indices of the Sudół stream water caused by a discharge of purified municipal sewage from a small mechanical-biological treatment plant with throughput of 300 m3·d−1 and a population equivalent (p.e. – 1,250 people. The discharge of purified sewage caused a worsening of the stream water quality. Most of the studied indices values increased in water below the treatment plant. Almost a 100-fold increase in ammonium nitrogen, 17-fold increase in phosphate concentrations and 12-fold raise in BOD5 concentrations were registered. Due to high values of these indices, the water physicochemical state was below good. Statistical analysis revealed a considerable effect of the purified sewage discharge on the stream water physicochemical state. A statistically significant increase in 10 indices values (BOD5, COD-Mn, EC, TDS, Cl−, Na+, K+, PO43−, N-NH4+ and N-NO2 as well as significant decline in the degree of water saturation with oxygen were noted below the sewage treatment plant. On the other hand, no statistically significant differences between the water indices values were registered between the measurement points localised 150 and 1,000 m below the purified sewage discharge. It evidences a slow process of the stream water self-purification caused by an excessive loading with pollutants originating from the purified sewage discharge.

  14. Towards spatially smart abatement of human pharmaceuticals in surface waters: Defining impact of sewage treatment plants on susceptible functions.

    Science.gov (United States)

    Coppens, Lieke J C; van Gils, Jos A G; Ter Laak, Thomas L; Raterman, Bernard W; van Wezel, Annemarie P

    2015-09-15

    For human pharmaceuticals, sewage treatment plants (STPs) are a major point of entry to surface waters. The receiving waters provide vital functions. Modeling the impact of STPs on susceptible functions of the surface water system allows for a spatially smart implementation of abatement options at, or in the service area of, STPs. This study was performed on a nation-wide scale for the Netherlands. Point source emissions included were 345 Dutch STPs and nine rivers from neighboring countries. The Dutch surface waters were represented by 2511 surface water units. Modeling was performed for two extreme discharge conditions. Monitoring data of 7 locations along the rivers Rhine and Meuse fall mostly within the range of modeled concentrations. Half of the abstracted volumes of raw water for drinking water production, and a quarter of the Natura 2000 areas (European Union nature protection areas) hosted by the surface waters, are influenced by STPs at low discharge. The vast majority of the total impact of all Dutch STPs during both discharge conditions can be attributed to only 19% of the STPs with regard to the drinking water function, and to 39% of the STPs with regard to the Natura 2000 function. Attributing water treatment technologies to STPs as one of the possible measures to improve water quality and protect susceptible functions can be done in a spatially smart and cost-effective way, using consumption-based detailed hydrological and water quality modeling.

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

    Science.gov (United States)

    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

  16. Groundwater discharge by evapotranspiration, flow of water in unsaturated soil, and stable isotope water sourcing in areas of sparse vegetation, Amargosa Desert, Nye County, Nevada

    Science.gov (United States)

    Moreo, Michael T.; Andraski, Brian J.; Garcia, C. Amanda

    2017-08-29

    This report documents methodology and results of a study to evaluate groundwater discharge by evapotranspiration (GWET) in sparsely vegetated areas of Amargosa Desert and improve understanding of hydrologic-continuum processes controlling groundwater discharge. Evapotranspiration and GWET rates were computed and characterized at three sites over 2 years using a combination of micrometeorological, unsaturated zone, and stable-isotope measurements. One site (Amargosa Flat Shallow [AFS]) was in a sparse and isolated area of saltgrass (Distichlis spicata) where the depth to groundwater was 3.8 meters (m). The second site (Amargosa Flat Deep [AFD]) was in a sparse cover of predominantly shadscale (Atriplex confertifolia) where the depth to groundwater was 5.3 m. The third site (Amargosa Desert Research Site [ADRS]), selected as a control site where GWET is assumed to be zero, was located in sparse vegetation dominated by creosote bush (Larrea tridentata) where the depth to groundwater was 110 m.Results indicated that capillary rise brought groundwater to within 0.9 m (at AFS) and 3 m (at AFD) of land surface, and that GWET rates were largely controlled by the slow but relatively persistent upward flow of water through the unsaturated zone in response to atmospheric-evaporative demands. Greater GWET at AFS (50 ± 20 millimeters per year [mm/yr]) than at AFD (16 ± 15 mm/yr) corresponded with its shallower depth to the capillary fringe and constantly higher soil-water content. The stable-isotope dataset for hydrogen (δ2H) and oxygen (δ18O) illustrated a broad range of plant-water-uptake scenarios. The AFS saltgrass and AFD shadscale responded to changing environmental conditions and their opportunistic water use included the time- and depth-variable uptake of unsaturated-zone water derived from a combination of groundwater and precipitation. These results can be used to estimate GWET in other areas of Amargosa Desert where hydrologic conditions are similar.

  17. Surface modification of chitosan/PEO nanofibers by air dielectric barrier discharge plasma for acetylcholinesterase immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Dorraki, Naghme, E-mail: n.dorraki@web.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Safa, Nasrin Navab [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Jahanfar, Mehdi [Protein Research Center, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of)

    2015-09-15

    Highlights: • We used an economical and effective method for surface modification. • Chitosan/PEO nanofibrous membranes were modified by air-DBD plasma. • The most NH{sub 3}{sup +} group was generated on the 6 min plasma modified membrane. • We immobilized acetylcholinesterase on the plasma modified and unmodified membranes. • More enzyme activity was detected on the modified membrane by plasma. - Abstract: There are different methods to modify polymer surfaces for biological applications. In this work we have introduced air-dielectric barrier discharge (DBD) plasma at atmospheric pressure as an economical and safe method for modifying the surface of electrospun chitosan/PEO (90/10) nanofibers for acetylcholinesterase (AChE) immobilization. According to the contact angle measurement results, the nanofibers become highly hydrophilic when they are exposed to the DBD plasma for 6 min in compared to unmodified membrane. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) results reveal hydroxyl, C=O and NH{sub 3}{sup +} polar groups increment after 6 min plasma treatment. Contact angle measurements and ATR-FTIR results are confirmed by X-ray photoelectron spectroscopy (XPS). AChE at pH 7.4 carries a negative charge and after immobilization on the surface of plasma-treated nanofibrous membrane attracts the NH{sub 3}{sup +} group and more enzyme activity is detected on the plasma-modified nanofibers for 6 min in compared to unmodified nanofibers. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used for the surface topography and morphology characterization. The results have proved that air-DBD plasma is a suitable method for chitosan/PEO nanofibrous membrane modification as a biodegradable and functionalized substrate for enzyme immobilization.

  18. Lithium content in potable water, surface water, ground water, and mineral water on the territory of Republic of Macedonia

    OpenAIRE

    Vesna Kostik; Biljana Bauer; Zoran Kavrakovski

    2014-01-01

    The aim of this study was to determine lithium concentration in potable water, surface water, ground, and mineral water on the territory of the Republic of Macedonia. Water samples were collected from water bodies such as multiple public water supply systems located in 13 cities, wells boreholes located in 12 areas, lakes and rivers located in three different areas. Determination of lithium concentration in potable water, surface water was performed by the technique of inductively coupl...

  19. Effects of surface modification by atmospheric oxygen dielectric barrier