WorldWideScience

Sample records for corona discharge treatment

  1. Effects of corona discharge treatment on some properties of wool ...

    African Journals Online (AJOL)

    Yomi

    2011-12-21

    Dec 21, 2011 ... Corona discharge after operation worsted water absorption property increased and the ... finally conditioned with atmospheric air (20°C, relative humidity ... For corona treatment, a glow discharge generator was used with a.

  2. Application of electric corona discharge for grain seeds treatment before sowing

    Science.gov (United States)

    Porsev, E. G.; Malozyomov, B. V.; Rozhkova, M. V.

    2017-10-01

    The paper overviews directions for electrotechnology treatment of grain seeds before sowing. The hypothesis of the germination enhancement of seeds if treated with corona discharge is presented here. Besides, the description of electrotechnology installation and facilities for it including manufacturing process quality obtained as a result of scientific tests are also provided in the paper.

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

    Science.gov (United States)

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

    2007-02-01

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

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

    International Nuclear Information System (INIS)

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

    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

  5. Corona Glow Discharge Plasma Treatment for Hidrophylicity Improvement of Polyester and Cotton Fabrics

    Science.gov (United States)

    Susan, A. I.; Widodo, M.; Nur, M.

    2017-07-01

    The effects of irradiation by a corona glow discharge plasma on hidrophylicity properties of polyester and cotton fabrics were investigated. We used a corona glow discharge plasma reactor with multiple points to plane electrodes, which was generated by a high voltage DC. Factors that affect the hidrophylicity properties were identified and evaluated as functions of irradiation parameters, which include duration of treatment, distance between electrodes, and bias voltage. It was readily observed from SEM examinations that plasma changed the surface morphology of both polyester and cotton fibers, giving result to an increased roughness to both of them. Results also showed that the hidrophylicityof polyester and cotton fabrics improved by the treatment, which is proportional to the time of treatment and voltage, but inversely proportional to the distance between electrodes. Time of treatment that provided the optimum enhancement of hidrophylicity for cotton is 15 minutes which improved the wetting time from 8.16 seconds to 1.26 seconds. For polyester, it took 15 minutes of irradiation time to improve the wetting time from 7340 seconds to 2905 seconds. The optimum distance between electrodes for both fabrics in this study was found to be 2 cm. Further analysis showed that the improved hidrophylicity properties is due to the creation of surface radicals by free radicals in the plasma leading to the formation of new water-attracting functional groups on the fiber surface.

  6. Ions mobilities in corona discharge

    International Nuclear Information System (INIS)

    Bakhtaev, Sh. A.; Bochkareva, G. V.; Sydykova, G. K.

    2000-01-01

    Ion mobility in unipolar corona at small inter-electron distances (up to 0.01 m) when as coroning element serves micro-wire is consider. Experimental data of ion mobility in corona discharge external zone in atmospheric air are obtained and its comparative analysis with known data is worked out. (author)

  7. Characteristics of a corona discharge with a hot corona electrode

    International Nuclear Information System (INIS)

    Kulumbaev, E. B.; Lelevkin, V. M.; Niyazaliev, I. A.; Tokarev, A. V.

    2011-01-01

    The effect of the temperature of the corona electrode on the electrical characteristics of a corona discharge was studied experimentally. A modified Townsend formula for the current-voltage characteristic of a one-dimensional corona is proposed. Gasdynamic and thermal characteristics of a positive corona discharge in a coaxial electrode system are calculated. The calculated results are compared with the experimental data.

  8. Alkali ion migration between stacked glass plates by corona discharge treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, Keiga [Research Institute for Electronic Science, Hokkaido University, N20 W10, Kita-ku, Sapporo, Hokkaido 001-0020 (Japan); Suzuki, Toshio [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama, Kanagawa 221-8755 (Japan); Ikeda, Hiroshi [Art, Science and Technology Center for Cooperative Research, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Sakai, Daisuke [Department of Electrical and Electronic Engineering, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Funatsu, Shiro; Uraji, Keiichiro [Production Technology Center, Asahi Glass Co., Ltd., 1-1 Suehiro-cyo, Tsurumiku, Yokohama, Kanagawa 230-0045 (Japan); Yamamoto, Kiyoshi [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama, Kanagawa 221-8755 (Japan); Harada, Kenji [Department of Computer Science, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Nishii, Junji, E-mail: nishii@es.hokudai.ac.jp [Research Institute for Electronic Science, Hokkaido University, N20 W10, Kita-ku, Sapporo, Hokkaido 001-0020 (Japan)

    2015-05-30

    Highlights: • Two stacked glass plates with a 1 mm gap were treated by corona discharge. • Spatial migration of alkali ion over the gap was demonstrated. • Hydrogen gas was necessary for uniform migration. • Surface modification was done with this process without high temperature or vacuum. - Abstract: Corona discharge reflects the spatial migration of alkali ions over a gap between two glass plates. This study examined stacked glass plates containing different alkali ions treated with the corona discharge plasma generated by applied voltage of 4.5 kV at 200 °C. Protons generated at the anode electrode penetrate into the potassium-ion-containing upper glass plate, which is located 5 mm below the anode electrode. Potassium ions intruded into the lower glass plate containing sodium ions placed on the cathode electrode, even over a 1 mm gap separating the plates. Finally, the sodium ion discharged on the cathode electrode. The hydrogen atmosphere was effective at inhibiting the potassium ion reaction with ambient gases during the spatial migration between the two glass plates.

  9. A study on the electrical characteristics of corona discharges for flue gas treatment

    International Nuclear Information System (INIS)

    Jung, Suk Won

    2000-02-01

    A wire- cylinder reactor and wire- plate reactor were designed and constructed for generating the corona discharges to be applied to the dissociation of NOx and SOx in the flue gases of combustion engines and power plants. Experiments for the characterization of the corona discharges in air were carried out. To obtain the pulsed voltage shape, a rotary spark gap switch was formed with a DC motor. A discharge circuit was constructed with a resistor (50kΩ ), DC high voltage power supply, a rotary spark gap switch. Two electric probes and voltage probe were installed in order to measure the total current, displacement current, conduction current and applied voltage. The charges, power, and energy in the two reactors were calculated from the measured voltage and current. Also, to find the frequency dependence of the corona discharge, the high frequency (20kHz) and high voltage power supply was used in the wire- cylinder reactor. The each obtained and calculated value from the probes in both reactor cases (high frequency, low frequency ) were compared each other

  10. Evaluation and Optimization of Electrode Configuration of Multi-Channel Corona Discharge Plasma for Dye-Containing Wastewater Treatment

    International Nuclear Information System (INIS)

    Ren Jingyu; Qu Guangzhou; Liang Dongli; Hu Shibin; Wang Tiecheng

    2015-01-01

    A discharge plasma reactor with a point-to-plane structure was widely studied experimentally in wastewater treatment. In order to improve the utilization efficiency of active species and the energy efficiency of this kind of discharge plasma reactor during wastewater treatment, the electrode configuration of the point-to-plane corona discharge reactor was studied by evaluating the effects of discharge spacing and adjacent point distance on discharge power and discharge energy density, and then dye-containing wastewater decoloration experiments were conducted on the basis of the optimum electrode configuration. The experimental results of the discharge characteristics showed that high discharge power and discharge energy density were achieved when the ratio of discharge spacing to adjacent point distance (d/s) was 0.5. Reactive Brilliant Blue (RBB) wastewater treatment experiments presented that the highest RBB decoloration efficiency was observed at d/s of 0.5, which was consistent with the result obtained in the discharge characteristics experiments. In addition, the biodegradability of RBB wastewater was enhanced greatly after discharge plasma treatment under the optimum electrode configuration. RBB degradation processes were analyzed by GC-MS and IC, and the possible mechanism for RBB decoloration was also discussed. (paper)

  11. 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

    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...

  12. Air corona discharge chemical kinetics

    International Nuclear Information System (INIS)

    Kline, L.E.; Kanter, I.E.

    1984-01-01

    We have theoretically studied the initial chemical processing steps which occur in pulseless, negative, dc corona discharges in flowing air. A rate equation model is used because these discharges consist of a very small ionization zone near the pin with most of the pin-plane gap filled by a drift zone where both the electric field and the electron density are relatively uniform. The primary activated species are N 2 (A),O and O 2 (a 1 Δ). The predicted activated species density due to one discharge is 100 ppm per ms . mA cm 2 assuming E/n=60 Td. In pure, dry air the final product due to these activated species is primarily O 3 . The NO /sub x/ production is about 0.5 ppm per mA. In moist air there is an additional production of about 1.5 ppm per mA of HO /sub x/ species. The predicted ozone formation reactions will be ''intercepted'' when impurities are present in the air. Impurities present at densities below about 0.1% will react primarily with the activated species rather than with electrons. Hence the predicted activated species density provides an estimate of the potential chemical processing performance of the discharge

  13. Modeling of experimental treatment of acetaldehyde-laden air and phenol-containing water using corona discharge technique.

    Science.gov (United States)

    Faungnawakij, Kajornsak; Sano, Noriaki; Charinpanitkul, Tawatchai; Tanthapanichakoon, Wiwut

    2006-03-01

    Acetaldehyde-laden air and phenol-contaminated water were experimentally treated using corona discharge reactions and gas absorption in a single water-film column. Mathematical modeling of the combined treatment was developed in this work. Efficient removal of the gaseous acetaldehyde was achieved while the corona discharge reactions produced short-lived species such as O and O- as well as ozone. Direct contact of the radicals and ions with water was known to produce aqueous OH radical, which contributes to the decomposition of organic contaminants: phenol, absorbed acetaldehyde, and intermediate byproducts in the water. The influence of initial phenol concentration ranging from 15 to 50 mg L(-1) and that of influent acetaldehyde ranging from 0 to 200 ppm were experimentally investigated and used to build the math model. The maximum energetic efficiency of TOC, phenol, and acetaldehyde were obtained at 25.6 x 10(-9) mol carbon J(-1), 25.0 x 10(-9) mol phenol J(-1), and 2.0 x 10(-9) mol acetaldehyde J(-1), respectively. The predictions for the decomposition of acetaldehyde, phenol, and their intermediates were found to be in good agreement with the experimental results.

  14. Pulsed Corona Discharge Generated By Marx Generator

    Science.gov (United States)

    Sretenovic, G. B.; Obradovic, B. M.; Kovacevic, V. V.; Kuraica, M. M.; Puric J.

    2010-07-01

    The pulsed plasma has a significant role in new environmental protection technologies. As a part of a pulsed corona system for pollution control applications, Marx type repetitive pulse generator was constructed and tested in arrangement with wire-plate corona reactor. We performed electrical measurements, and obtained voltage and current signals, and also power and energy delivered per pulse. Ozone formation by streamer plasma in air was chosen to monitor chemical activity of the pulsed corona discharge.

  15. Investigation of the decolorization efficiency of two pin-to-plate corona discharge plasma system for industrial wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    El-Tayeb, A., E-mail: ahmed.khalil@ejust.edu.eg; El-Shazly, A. H.; Elkady, M. F. [Egypt−Japan University of Science and Technology, Chemicals and Petrochemicals Engineering Department (Egypt); Abdel-Rahman, A. B. [Egypt−Japan University of Science and Technology, Electronics and Communications Engineering Department (Egypt)

    2016-09-15

    In this article, a dual pin-to-plate high-voltage corona discharge system is introduced to study experimentally the gap distance, the contact time, the effect of pin and plate materials, the thickness of ground plate and the conductivity on the amount of Acid Blue 25 dye color removal efficiency from polluted water. A study for the optimum air gap distance between dual pin and surface of Acid Blue 25 dye solution is carried out using 3D-EM simulator to find maximum electric field intensity at the tip of both pins. The outcomes display that the best gap for corona discharge is approximately 5 mm for 15-kV source. This separation is constant during the study of other factors. In addition, an investigation of the essential reactive species responsible for oxidation of the dye organic compounds (O{sub 3} in air discharge, O{sub 3} in water, and H{sub 2}O{sub 2}) during the experimental time is conducted. Three various materials such as: stainless steel, copper and aluminum are used for pins and plate. The maximum color removal efficiencies of Acid Blue 25 dyes are 99.03, 82.04, and 90.78% after treatment time 15 min for stainless steel, copper, and aluminum, respectively. Measurement results for the impact of thickness of an aluminum ground plate on color removal competence show color removal efficiencies of 86.3, 90.78, and 98.06% after treatment time 15 min for thicknesses of 2, 0.5, and 0.1 mm, respectively. The increasing of the solution conductivity leads to the reduction of decolorization efficiency. A kinetic model is used to define the performance of corona discharge system. The models of pseudo-zero-order, pseudo-first-order, and pseudo-second-order reaction kinetics are utilized to investigate the decolorization of Acid Blue 25 dye. The rate of degradation of Acid Blue 25 dye follows the pseudo-first-order kinetics in the dye concentration.

  16. Investigation of the decolorization efficiency of two pin-to-plate corona discharge plasma system for industrial wastewater treatment

    International Nuclear Information System (INIS)

    El-Tayeb, A.; El-Shazly, A. H.; Elkady, M. F.; Abdel-Rahman, A. B.

    2016-01-01

    In this article, a dual pin-to-plate high-voltage corona discharge system is introduced to study experimentally the gap distance, the contact time, the effect of pin and plate materials, the thickness of ground plate and the conductivity on the amount of Acid Blue 25 dye color removal efficiency from polluted water. A study for the optimum air gap distance between dual pin and surface of Acid Blue 25 dye solution is carried out using 3D-EM simulator to find maximum electric field intensity at the tip of both pins. The outcomes display that the best gap for corona discharge is approximately 5 mm for 15-kV source. This separation is constant during the study of other factors. In addition, an investigation of the essential reactive species responsible for oxidation of the dye organic compounds (O 3 in air discharge, O 3 in water, and H 2 O 2 ) during the experimental time is conducted. Three various materials such as: stainless steel, copper and aluminum are used for pins and plate. The maximum color removal efficiencies of Acid Blue 25 dyes are 99.03, 82.04, and 90.78% after treatment time 15 min for stainless steel, copper, and aluminum, respectively. Measurement results for the impact of thickness of an aluminum ground plate on color removal competence show color removal efficiencies of 86.3, 90.78, and 98.06% after treatment time 15 min for thicknesses of 2, 0.5, and 0.1 mm, respectively. The increasing of the solution conductivity leads to the reduction of decolorization efficiency. A kinetic model is used to define the performance of corona discharge system. The models of pseudo-zero-order, pseudo-first-order, and pseudo-second-order reaction kinetics are utilized to investigate the decolorization of Acid Blue 25 dye. The rate of degradation of Acid Blue 25 dye follows the pseudo-first-order kinetics in the dye concentration.

  17. Characteristics of pulse corona discharge over water surface

    Science.gov (United States)

    Fujii, Tomio; Arao, Yasushi; Rea, Massimo

    2008-12-01

    Production of ozone and OH radical is required to advance the plasma chemical reactions in the NOx removal processes for combustion gas treatment. The corona discharge to the water surface is expected to induce the good conditions for the proceeding of the NO oxidation and the NO2 dissolution removal into water. In order to get the fundamental data of the corona discharge over the water surface, the positive and negative V-I characteristics and the ozone production were measured with the multi needle and the saw-edge type of the discharge electrodes. The pulse corona characteristics were also measured with some different waveforms of the applied pulse voltage. The experiments were carried out under the atmospheric pressure and room temperature. Both the DC and the pulse corona to the water surface showed a stable and almost the same V-I characteristics as to plate electrodes though the surface of water was waved by corona wind. The positive streamer corona showed more ozone production than the negative one both in the DC and in the pulse corona.

  18. Characteristics of pulse corona discharge over water surface

    International Nuclear Information System (INIS)

    Fujii, Tomio; Arao, Yasushi; Rea, Massimo

    2008-01-01

    Production of ozone and OH radical is required to advance the plasma chemical reactions in the NOx removal processes for combustion gas treatment. The corona discharge to the water surface is expected to induce the good conditions for the proceeding of the NO oxidation and the NO 2 dissolution removal into water. In order to get the fundamental data of the corona discharge over the water surface, the positive and negative V-I characteristics and the ozone production were measured with the multi needle and the saw-edge type of the discharge electrodes. The pulse corona characteristics were also measured with some different waveforms of the applied pulse voltage. The experiments were carried out under the atmospheric pressure and room temperature. Both the DC and the pulse corona to the water surface showed a stable and almost the same V-I characteristics as to plate electrodes though the surface of water was waved by corona wind. The positive streamer corona showed more ozone production than the negative one both in the DC and in the pulse corona.

  19. Negative corona discharges modelling. Application to the electrostatic precipitation

    International Nuclear Information System (INIS)

    Gaychet, S.

    2010-01-01

    Electrostatic precipitation presents many advantages from the nuclear wastes treatment's point of view. Indeed, this kind of process can capture submicron particles without producing secondary wastes (no filter media) and without pressure looses in the exhaust circuit. The work presented in this thesis concerns the study of negative corona discharges in air at atmospheric pressure occurring in an electrostatic precipitator (ESP) developed by the CEA (Atomic Energy Committee). The aim of this study is to determine how the electrostatic precipitation dedicated phenomena, especially the specific high voltage generator, the gas temperature and the fact that particles are flowing through the gap then collapsing on the electrodes, modify the discharge to improve the efficiency of ESPs. This work is based on a fundamental experimental study of the negative corona discharge and on numerical simulations of this discharge under conditions close to those of the lab scale ESP developed by the CEA. (author) [fr

  20. An analytical theory of corona discharge plasmas

    International Nuclear Information System (INIS)

    Uhm, H.S.; Lee, W.M.

    1997-01-01

    In this paper we describe an analytical investigation of corona discharge systems. Electrical charge and the energy transfer mechanism are investigated based on the circuit analysis. Efficient delivery of electrical energy from the external circuit to the reactor chamber is a major issue in design studies. The optimum condition obtained in this paper ensures 100% energy transfer. Second-order coupled differential equations are numerically solved. All the analytical results agree remarkably well with numerical data. The reactor capacitor plays a pivotal role in circuit performance. The voltage profile is dominated by the reactor capacitor. Corona discharge properties in the reactor chamber are also investigated, assuming that a specified voltage profile V(t) is fed through the inner conductor. The analytical description is based on the electron moment equation. Defining the plasma breakdown parameter u=V/R c p, plasma is generated for a high-voltage pulse satisfying u>u c , where u c is the critical breakdown parameter defined by geometrical configuration. Here, u is in units of a million volts per m per atm, and R c is the outer conductor radius. It is found that the plasma density profile generated inside the reactor chamber depends very sensitively on the system parameters. A small change of a physical parameter can easily lead to a density change in one order of magnitude

  1. Comparative study on decontamination treatment of paper-based materials in corona discharge and HF cold plasma

    Science.gov (United States)

    Ioanid, E. G.; Dunca, S.; Rusu, D.; Tǎnase, C.

    2012-04-01

    Documents decontamination using dry methods, less invasive than the wet ones implying toxic nocuous substances for cellulose-based materials, has been the object of numerous studies. In recent years mixed researchers teams have been studying the possibility of one-step document decontamination performed by a dry treatment, the risks of repeated wet manipulation thus being reduced. Among physical methods appropriate to this end, high-frequency cold plasma and corona effect can be mentioned. Our studies were carried out on samples taken from ancient books with no cultural heritage value. The decontamination efficiency and the impact on paper of the two types of treatments were determined by: microbiological analysis, scanning electron microscopy, FTIR, chromatic alterations and gloss determination. The above-mentioned procedures eliminate the use of chemical conservation substances, nocuous for the paper support. At the same time the health risk for conservators, restorers, archivists or archive's users is removed.

  2. Ionization and Corona Discharges from Stressed Rocks

    Science.gov (United States)

    Winnick, M. J.; Kulahci, I.; Cyr, G.; Tregloan-Reed, J.; Freund, F. T.

    2008-12-01

    Pre-earthquake signals have long been observed and documented, though they have not been adequately explained scientifically. These signals include air ionization, occasional flashes of light from the ground, radio frequency emissions, and effects on the ionosphere that occur hours or even days before large earthquakes. The theory that rocks function as p-type semiconductors when deviatoric stresses are applied offers a mechanism for this group of earthquake precursors. When an igneous or high-grade metamorphic rock is subjected to deviatoric stresses, peroxy bonds that exist in the rock's minerals as point defects dissociate, releasing positive hole charge carriers. The positive holes travel by phonon-assisted electron hopping from the stressed into and through the unstressed rock volume and build up a positive surface charge. At sufficiently large electric fields, especially along edges and sharp points of the rock, air molecules become field-ionized, loosing an electron to the rock surface and turning into airborne positive ions. This in turn can lead to corona discharges, which manifest themselves by flashes of light and radio frequency emissions. We applied concentrated stresses to one end of a block of gabbro, 30 x 15 x 10 cm3, inside a shielded Faraday cage and observed positive ion currents through an air gap about 25 cm from the place where the stresses were applied, punctuated by short bursts, accompanied by flashes of light and radio frequency emissions characteristic of a corona discharge. These observations may serve to explain a range of pre-earthquake signals, in particular changes in air conductivity, luminous phenomena, radio frequency noise, and ionospheric perturbations.

  3. The effect of atmospheric corona treatment on AA1050 aluminium

    DEFF Research Database (Denmark)

    Jariyaboon, Manthana; Møller, Per; Dunin-Borkowski, Rafal E.

    2010-01-01

    The effect of atmospheric corona discharge on AM 050 aluminium surface was investigated using electrochemical polarization, SEM-EDX, FIB-SEM. and XPS. The corona treatment was performed with varying time (1, 5, and 15 min) in atmospheric air. A 200 nm oxide layer was generated on AA1050 after...

  4. ''Relaxing phenomena'' in negative corona discharge in air: new aspects

    International Nuclear Information System (INIS)

    Strelle, D.; Pavlik, M.; Skalny, J.D.

    1998-01-01

    Several conspicuous differences between the positive and the negative corona discharges in air observed in small discharge gaps have been explained by two recent theoretical models considering the ion-molecule and chemical reactions in the negative corona discharge in air. In the present paper the discrepancies of these models are discussed, and the earlier experimental data and the presumptions used in the models are re-examined in the light of the latest experimentally confirmed facts. (J.U.)

  5. Chaotic characteristics of corona discharges in atmospheric air

    International Nuclear Information System (INIS)

    Tan Xiangyu; Zhang Qiaogen; Wang Xiuhuan; Sun Fu; Zha Wei; Jia Zhijie

    2008-01-01

    A point-plane electrode system in atmospheric air is established to investigate the mechanism of the corona discharge. By using this system, the current pulses of the corona discharges under the 50 Hz ac voltage are measured using partial discharge (PD) measurement instrument and constitute the point-plane voltage-current (V-I) characteristic equation together with the voltage. Then, this paper constructs the nonlinear circuit model and differential equations of the system in an attempt to give the underlying dynamic mechanism based on the nonlinear V-I characteristics of the point-plane corona discharges. The results show that the chaotic phenomenon is found in the corona circuit by the experimental study and nonlinear dynamic analysis. The basic dynamic characteristics, including the Lyapunov exponent, the existence of the strange attractors, and the equilibrium points, are also found and analyzed in the development process of the corona circuit. Moreover, the time series of the corona current pulses obtained in the experiment is used to demonstrate the chaotic characteristics of the corona current based on the nonlinear dynamic circuit theory and the experimental basis. It is pointed out that the corona phenomenon is not a purely stochastic phenomenon but a short term deterministic chaotic activity

  6. Impedance-stabilized positive corona discharge and its decontamination properties

    Energy Technology Data Exchange (ETDEWEB)

    Horak, P; Khun, J, E-mail: pavel.horak@vscht.c [Department of Physics and Measurements, Faculty of Chemical Engineering, Institute of Chemical Technology, Technicka 5, 166 28 Praha 6 (Czech Republic)

    2010-04-01

    The point-to-plane DC corona discharge in air at atmospheric pressure was stabilized by a serially connected ballast impedance. The ballast impedance was implemented by a resistor-capacitor group connected in parallel. In the case of connecting the serial impedance into the electric circuit of a negative corona, the transition into a spark takes place at parameters similar to those of a non-stabilized discharge. In contrast, in the case of a positive corona, the discharge does not undergo a transition into a spark, but rather into a mode of periodic streamers. We measured the bactericidal effect of the stabilized discharge. The experiments showed that after a 2-minute exposure the quantity of surviving bacteria decreased from 95% for a non-stabilized discharge down to 5% for a stabilized one.

  7. Impedance-stabilized positive corona discharge and its decontamination properties

    International Nuclear Information System (INIS)

    Horak, P; Khun, J

    2010-01-01

    The point-to-plane DC corona discharge in air at atmospheric pressure was stabilized by a serially connected ballast impedance. The ballast impedance was implemented by a resistor-capacitor group connected in parallel. In the case of connecting the serial impedance into the electric circuit of a negative corona, the transition into a spark takes place at parameters similar to those of a non-stabilized discharge. In contrast, in the case of a positive corona, the discharge does not undergo a transition into a spark, but rather into a mode of periodic streamers. We measured the bactericidal effect of the stabilized discharge. The experiments showed that after a 2-minute exposure the quantity of surviving bacteria decreased from 95% for a non-stabilized discharge down to 5% for a stabilized one.

  8. Triggering Excimer Lasers by Photoionization from Corona Discharges

    Science.gov (United States)

    Xiong, Zhongmin; Duffey, Thomas; Brown, Daniel; Kushner, Mark

    2009-10-01

    High repetition rate ArF (192 nm) excimer lasers are used for photolithography sources in microelectronics fabrication. In highly attaching gas mixtures, preionization is critical to obtaining stable, reproducible glow discharges. Photoionization from a separate corona discharge is one technique for preionization which triggers the subsequent electron avalanche between the main electrodes. Photoionization triggering of an ArF excimer laser sustained in multi-atmosphere Ne/Ar/F2/Xe gas mixtures has been investigated using a 2-dimensional plasma hydrodynamics model including radiation transport. Continuity equations for charged and neutral species, and Poisson's equation are solved coincident with the electron temperature with transport coefficients obtained from solutions of Boltzmann's equation. Photoionizing radiation is produced by a surface discharge which propagates along a corona-bar located adjacent to the discharge electrodes. The consequences of pulse power waveform, corona bar location, capacitance and gas mixture on uniformity, symmetry and gain of the avalanche discharge will be discussed.

  9. Generation of ozone by pulsed corona discharge over water surface in hybrid gas-liquid electrical discharge reactor

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Člupek, Martin; Babický, Václav; Šunka, Pavel; Janda, V.

    2005-01-01

    Roč. 38, č. 3 (2005), s. 409-416 ISSN 0022-3727 R&D Projects: GA ČR(CZ) GA202/02/1026 Institutional research plan: CEZ:AV0Z20430508 Keywords : Corona discharge * hybrid reactor * ozone * water treatment Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.957, year: 2005

  10. Ozone formation by gaseous corona discharge generated above aqueous solution

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Člupek, Martin; Babický, Václav; Šunka, Pavel

    2004-01-01

    Roč. 54, suppl. C (2004), C909-C913 ISSN 0011-4626. [Symposium on Plasma Physics and Technology /21st/. Praha, 14.06.2004-17.06.2004] R&D Projects: GA ČR GA202/02/1026 Keywords : corona discharg, ozone Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.292, year: 2004

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

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Muhammad Arif [Applied Chemistry Division, PINSTECH, PO Nilore, Islamabad (Pakistan); Ubaid-ur-Rehman [Applied Chemistry Division, PINSTECH, PO Nilore, Islamabad (Pakistan); Ghaffar, Abdul; Ahmed, Kurshid [Electronics Division, PINSTECH, PO Nilore, Islamabad (Pakistan)

    2002-08-01

    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 -1} methylene blue in distilled water was decolourized in 120 min. Bubbling O{sub 2} at 10 ml min{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 -1} at 10 ml min{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 30 min by corona discharge with O{sub 2} bubbling, and in 11 min by corona discharge with bubbling of O{sub 2} containing 1500 {mu}mol O{sub 3} l{sup -1}.

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

    International Nuclear Information System (INIS)

    Malik, Muhammad Arif; Ubaid-ur-Rehman; Ghaffar, Abdul; Ahmed, Kurshid

    2002-01-01

    The effect of O 2 and O 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 MΩ 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 -1 methylene blue in distilled water was decolourized in 120 min. Bubbling O 2 at 10 ml min -1 through the discharge region reduced the decolourization time to 25 min. Bubbling O 2 containing 1500 μmol O 3 l -1 at 10 ml min -1 reduced the decolourization time to 8 min. The O 3 was produced by fractionating input energy between a water treatment reactor and a O 3 generator, i.e. no additional energy was consumed for O 3 production. Under the same experimental conditions methylene blue solution in tap water was decolourized in >210 min by corona discharge in solution, in 30 min by corona discharge with O 2 bubbling, and in 11 min by corona discharge with bubbling of O 2 containing 1500 μmol O 3 l -1

  13. Dielectric fluid directional spreading under the action of corona discharge

    Science.gov (United States)

    Zhou, Shangru; Liu, Jie; Hu, Qun; Jiang, Teng; Yang, Jinchu; Liu, Sheng; Zheng, Huai

    2018-01-01

    Liquid spreading is a very common nature phenomenon and of significant importance for a broad range of applications. In this study, a dielectric fluid directional spreading phenomenon is presented. Under the action of corona discharge, a dielectric fluid, here a typical silicone directionally spreads along conductive patterns on conductive/nonconductive substrates. Directional spreading behaviors of silicone were experimentally observed on different conductive patterns in detail. Spreading speeds were analyzed at different driving voltages, which induced the corona discharge. The presented phenomenon may be useful to inspire several techniques of manipulating liquid transportation and fabricating micropatterns.

  14. DBD-Corona Discharge for Degradation of Toxic Gases

    International Nuclear Information System (INIS)

    Pacheco-Pacheco, M.; Pacheco-Sotelo, J.; Moreno-Saavedra, H.; Diaz-Gomez, J. A.; Mercado-Cabrera, A.; Yousfi, M.

    2007-01-01

    The non-thermal plasma technology is a promising technique to treat SO 2 and NO x . Chemical radicals produced with this technology can remove several pollutants at atmospheric pressure in a very short period of time simultaneously. Both theoretical and experimental study on SO 2 and NO x removal, by a dielectric barrier discharge (DBD) with corona effect, is presented

  15. Filamentation of diamond nanoparticles treated in underwater corona discharge

    Czech Academy of Sciences Publication Activity Database

    Jirásek, Vít; Lukeš, Petr; Kozak, Halyna; Artemenko, Anna; Člupek, Martin; Čermák, Jan; Rezek, Bohuslav; Kromka, Alexander

    2016-01-01

    Roč. 6, č. 3 (2016), 2352-2360 ISSN 2046-2069 R&D Projects: GA ČR GA15-01687S; GA MŠk(CZ) LD14011 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : nanodiamonds * pulsed streamer corona discharge * filamentation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.108, year: 2016

  16. The Effect of a Corona Discharge on a Lightning Attachment

    International Nuclear Information System (INIS)

    Aleksandrov, N.L.; Bazelyan, E.M.; Raizer, Yu.P.

    2005-01-01

    The interaction between the lightning leader and the space charge accumulated near the top of a ground object in the atmospheric electric field is considered using analytical and numerical models developed earlier to describe spark discharges in long laboratory gaps. The specific features of a nonstationary corona discharge that develops in the electric field of a thundercloud and a downward lightning leader are analyzed. Conditions for the development of an upward lightning discharge from a ground object and for the propagation of an upward-connecting leader from the object toward a downward lightning leader (the process determining the point of strike to the ground) are investigated. Possible mechanisms for the interaction of the corona space charge with an upward leader and prospects of using it to control downward lightning discharges are analyzed

  17. CORONA DISCHARGE IGNITION FOR ADVANCED STATIONARY NATURAL GAS ENGINES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Paul D. Ronney

    2003-09-12

    An ignition source was constructed that is capable of producing a pulsed corona discharge for the purpose of igniting mixtures in a test chamber. This corona generator is adaptable for use as the ignition source for one cylinder on a test engine. The first tests were performed in a cylindrical shaped chamber to study the characteristics of the corona and analyze various electrode geometries. Next a test chamber was constructed that closely represented the dimensions of the combustion chamber of the test engine at USC. Combustion tests were performed in this chamber and various electrode diameters and geometries were tested. The data acquisition and control system hardware for the USC engine lab was updated with new equipment. New software was also developed to perform the engine control and data acquisition functions. Work is underway to design a corona electrode that will fit in the new test engine and be capable igniting the mixture in one cylinder at first and eventually in all four cylinders. A test engine was purchased for the project that has two spark plug ports per cylinder. With this configuration it will be possible to switch between corona ignition and conventional spark plug ignition without making any mechanical modifications.

  18. Pulsed corona discharge oxidation of aqueous carbamazepine micropollutant.

    Science.gov (United States)

    Ajo, Petri; Krzymyk, Ewelina; Preis, Sergei; Kornev, Iakov; Kronberg, Leif; Louhi-Kultanen, Marjatta

    2016-08-01

    The anti-epileptic drug carbamazepine (CBZ) receives growing attention due to slow biodegradation and inherent accumulation in the aquatic environment. The application of a gas-phase pulsed corona discharge (PCD) was investigated to remove CBZ from synthetic solutions and spiked wastewater effluent from a municipal wastewater treatment facility. The treated water was showered between high voltage (HV) wires and grounded plate electrodes, to which ultra-short HV pulses were applied. CBZ was readily oxidized and 1-(2-benzaldehyde)-4-hydroquinazoline-2-one (BQM) and 1-(2-benzaldehyde)-4-hydro-quinazoline-2,4-dione (BQD) were identified as the most abundant primary transformation products, which, contrary to CBZ ozonation data available in the literature, were further easily oxidized with PCD: BQM and BQD attributed to only a minor portion of the target compound oxidized. In concentrations commonly found in wastewater treatment plant effluents (around 5 µg L(-1)), up to 97% reduction in CBZ concentration was achieved at mere 0.3 kW h m(-3) energy consumption, and over 99.9% was removed at 1 kW h m(-3). The PCD application proved to be efficient in the removal of both the parent substance and its known transformation products, even with the competing reactions in the complex composition of wastewater.

  19. Corona discharge induced snow formation in a cloud chamber.

    Science.gov (United States)

    Ju, Jingjing; Wang, Tie-Jun; Li, Ruxin; Du, Shengzhe; Sun, Haiyi; Liu, Yonghong; Tian, Ye; Bai, Yafeng; Liu, Yaoxiang; Chen, Na; Wang, Jingwei; Wang, Cheng; Liu, Jiansheng; Chin, S L; Xu, Zhizhan

    2017-09-18

    Artificial rainmaking is in strong demand especially in arid regions. Traditional methods of seeding various Cloud Condensation Nuclei (CCN) into the clouds are costly and not environment friendly. Possible solutions based on ionization were proposed more than 100 years ago but there is still a lack of convincing verification or evidence. In this report, we demonstrated for the first time the condensation and precipitation (or snowfall) induced by a corona discharge inside a cloud chamber. Ionic wind was found to have played a more significant role than ions as extra CCN. In comparison with another newly emerging femtosecond laser filamentation ionization method, the snow precipitation induced by the corona discharge has about 4 orders of magnitude higher wall-plug efficiency under similar conditions.

  20. High tension generator for corona barrier discharge

    International Nuclear Information System (INIS)

    Baltag, O.; Costandache, D.; Gheorghiu, M.; Paraschivescu, A.; Popa, G.

    2001-01-01

    Different types of high-voltage generators are in use for the study of low pressure (or atmospheric) discharges. Mostly used are the Tesla coils generators or the power generators working in linear or switching regime. The Tesla coils generators have the advantage of a simple bloc diagram. In exchange, they have a number of short-comings, such as: the difficulty in modifying the frequency of the high voltage pulses, generation of a high voltage and frequency pulse train, the amplitude is not constant.This paper presents a high-voltage generator meant to be used in the study of the dielectric barrier discharges (DBD). The bloc diagram is presented. Performances obtained are as follows: - Generated frequency: 10 Hz - 100 Hz, 100 Hz - 1 KHz, 1 KHz - 10 KHz; - High voltage pulses control: a single pulse from an internal or external generator; - Synchronization with the oscilloscope, variable delay: 5 μs - 0.1 s; - Output voltage: variable both smoothly and in steps: 1 kV -15 kV; - High voltage polarity: mono and bipolar; - Output power during the continuous duty: 300 VA (maximum 600 VA for a short time); - Pulse energy: 0.23 J; - Pulse duration: 4 μs - 50 μs

  1. Pulsed corona discharge for improving treatability of coking wastewater.

    Science.gov (United States)

    Liu, Ming; Preis, Sergei; Kornev, Iakov; Hu, Yun; Wei, Chao-Hai

    2018-02-01

    Coking wastewater (CW) contains toxic and macromolecular substances that inhibit biological treatment. The refractory compounds remaining in biologically treated coking wastewater (BTCW) provide chemical oxygen demand (COD) and color levels that make it unacceptable for reuse or disposal. Gas-phase pulsed corona discharge (PCD) utilizing mostly hydroxyl radicals and ozone as oxidants was applied to both raw coking wastewater (RCW) and BTCW wastewater as a supplemental treatment. The energy efficiency of COD, phenol, thiocyanate and cyanide degradation by PCD was the subject of the research. The cost-effective removal of intermediate oxidation products with addition of lime was also studied. The energy efficiency of oxidation was inversely proportional to the pulse repetition frequency: lower frequency allows more effective utilization of ozone at longer treatment times. Oxidative treatment of RCW showed the removal of phenol and thiocyanate at 800 pulses per second from 611 to 227mg/L and from 348 to 86mg/L, respectively, at 42kWh/m 3 delivered energy, with substantial improvement in the BOD 5 /COD ratio (from 0.14 to 0.43). The COD and color of BTCW were removed by 30% and 93%, respectively, at 20kWh/m 3 , showing energy efficiency for the PCD treatment exceeding that of conventional ozonation by a factor of 3-4. Application of lime appeared to be an effective supplement to the PCD treatment of RCW, degrading COD by about 28% at an energy input of 28kWh/m 3 and the lime dose of 3.0kg/m 3 . The improvement of RCW treatability is attributed to the degradation of toxic substances and fragmentation of macromolecular compounds. Copyright © 2017. Published by Elsevier B.V.

  2. Semi-analytical modelling of positive corona discharge in air

    Science.gov (United States)

    Pontiga, Francisco; Yanallah, Khelifa; Chen, Junhong

    2013-09-01

    Semianalytical approximate solutions of the spatial distribution of electric field and electron and ion densities have been obtained by solving Poisson's equations and the continuity equations for the charged species along the Laplacian field lines. The need to iterate for the correct value of space charge on the corona electrode has been eliminated by using the corona current distribution over the grounded plane derived by Deutsch, which predicts a cos m θ law similar to Warburg's law. Based on the results of the approximated model, a parametric study of the influence of gas pressure, the corona wire radius, and the inter-electrode wire-plate separation has been carried out. Also, the approximate solutions of the electron number density has been combined with a simplified plasma chemistry model in order to compute the ozone density generated by the corona discharge in the presence of a gas flow. This work was supported by the Consejeria de Innovacion, Ciencia y Empresa (Junta de Andalucia) and by the Ministerio de Ciencia e Innovacion, Spain, within the European Regional Development Fund contracts FQM-4983 and FIS2011-25161.

  3. DC corona discharge ozone production enhanced by magnetic field

    Science.gov (United States)

    Pekárek, S.

    2010-01-01

    We have studied the effect of a stationary magnetic field on the production of ozone from air at atmospheric pressure by a negative corona discharge in a cylindrical electrode configuration. We used a stainless steel hollow needle placed at the axis of the cylindrical discharge chamber as a cathode. The outer wall of the cylinder was used as an anode. The vector of magnetic induction was perpendicular to the vector of current density. We found that: (a) the magnetic field extends the current voltage range of the discharge; (b) for the discharge in the Trichel pulses regime and in the pulseless glow regime, the magnetic field has no substantial effect on the discharge voltage or on the concentration of ozone that is produced; (c) for the discharge in the filamentary streamer regime for a particular current, the magnetic field increases the discharge voltage and consequently an approximately 30% higher ozone concentration can be obtained; (d) the magnetic field does not substantially increase the maximum ozone production yield. A major advantage of using a magnetic field is that the increase in ozone concentration produced by the discharge can be obtained without additional energy requirements.

  4. Corona discharge ion mobility spectrometry at reduced pressures

    International Nuclear Information System (INIS)

    Tabrizchi, Mahmoud; Rouholahnejad, Fereshteh

    2004-01-01

    Ion mobility spectrometers (IMSs) normally operate at ambient pressure. In this work an IMS cell has been designed and constructed to allow the pressure to be reduced inside the IMS cell. In this cell, corona discharge was employed as the ionization source. Reducing pressure affected both the discharge and the performance of the IMS. The discharge current was observed to increase with reducing pressure while the ignition potential decreased. The ion current received at the collector plate was also increased about 50 times when the pressure was reduced from ambient pressure to 15 Torr. The higher ion current can lead to an extended dynamic range. IMS spectra were recorded at various pressures and the results show that the drift times shift perfectly linear with pressure. This suggests that unlike temperature, pressure correction for ion mobility spectra is as simple as multiplying the drift times by a factor of 760/P

  5. Oxidation of sulfur and nitrogen oxides by pulse corona discharge

    International Nuclear Information System (INIS)

    Amirov, R.H.; Desiaterik, Yu.N.; Filimonova, E.A.; Zhelezniak, M.B.; Chae, J.O.

    1996-01-01

    The NO x and SO 2 removal efficiency of the corona reactor has been measured both with and without ammonia addition to the gas stream. Experimental conditions are described. The dependence of NO and SO 2 removal efficiency from flow rate and initial pollutant concentrations were measured. One test with fixed amount of the inputted energy per the unit of SO 2 but with different initial concentration have been made. It is found that increasing of the initial concentration from 200 ppm to 700 ppm can enlarge the removal efficiency by factor 2.5. Some tests were carried out with both pollutant gases SO 2 and NO simultaneously. An efficiency on the SO 2 removal of 96% and on the NO removal 70% in pulse corona have been achieved with ammonia addition when SO 2 initial concentration was 480 ppm and the NO initial concentration was 230 ppm. A numerical model for NO and SO 2 oxidation in homogeneous gas flow has been developed. The flow contains cold (T = 300-400 K) background components N 2 , CO 2 , H 2 O, O 2 and impurities SO 2 , NO x , CO. A source of chemically active species is an electrical streamer discharge of corona type. (authors)

  6. The role of photoionization in negative corona discharge

    Directory of Open Access Journals (Sweden)

    B. X. Lu

    2016-09-01

    Full Text Available The effect of photoionization on the negative corona discharge was simulated based on the needle to plane air gaps. The Trichel pulse, pulse train, electron density and the distribution of electric field will be discussed in this manuscript. Effect of photoionization on the magnitude and interval of the first pulse will be discussed for different applied voltages. It is demonstrated that the peak of the first pulse current could be weakened by photoionization and a critical voltage of the first pulse interval influenced by photoionization was given.

  7. Toxic Gas Removal by Dielectric Discharge with Corona Effect

    International Nuclear Information System (INIS)

    Moreno, H.; Pacheco, M.; Mercado, A.; Cruz, A.; Pacheco, J.; Yousfi, M.; Eichwald, O.; Benhenni, M.

    2006-01-01

    In this work, a theoretical and experimental study on SO2 and NOx removal by non-thermal plasma technology, more specifically a dielectric barrier (DBD) discharge combined with the Corona effect, is presented. Results obtained from a theoretical study describe the chemical kinetic model of SO2 and NOx removal processes; the effect of OH radicals in removal of both gases is noteworthy. Experimental results of de-SO2 process are reported. Also, optical emission spectroscopy study was applied on some atomic helium lines to obtain temperature of electrons in the non-thermal plasma

  8. 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...

  9. Numerical and Experimental Study of Amplitude Modulated Positive Corona Discharge

    Directory of Open Access Journals (Sweden)

    Pablo Martín GOMEZ

    2014-12-01

    Full Text Available The electrical behavior of a modulated positive corona discharge loudspeaker was studied. A coaxial transducer in air was built using a central copper wire of 75 mm radius (inner electrode and a perforated tube of 11 mm (outer electrode. A high voltage DC supply provided the bias current and a sinusoidal signal was superimposed to measure the discharge admittance. The experimental results could not be matched to previously reported equivalent circuits with fixed components. Using the basic equations that describe the ion motion, a numerical model was proposed. The computed values matched well the experimental data and suggested an equivalent circuit composed of frequency dependent conductance and capacitance. This dependence is closely related to the ion travel time between electrodes (transit time. Simulations carried out at several inter-electrode distances could be synthesized in a single plot where the different results overlap and further emphasize the role of the transit time. This numerical model proved to be an efficient tool to simulate and design modulated corona transducers.

  10. Comparison of sodium naphthenate and air-ionization corona discharge as surface treatments for the ethylene-tetrafluoroethylene polymer (ETFE) to improve adhesion between ETFE and acrylonitrile-butadiene-styrene polymer (ABS) in the presence of a cyanoacrylate adhesive (CAA)

    International Nuclear Information System (INIS)

    Johanning-Solís, Ana Lucía; Stradi-Granados, Benito A

    2014-01-01

    This study compares two ethylene-tetrafluoroethylene (ETFE) surface activation treatments, namely chemical attack with a solution of sodium naphthenate and plasma erosion via air-ionization corona discharge in order to improve the adhesive properties of the ETFE. An experimental design was prepared for both treatments in order to assess the effect of the treatment characteristics on the tensile load needed to break the bond between the ETFE and the acrylonitrile-butadiene-styrene polymer (ABS) formed with a cyanoacrylate adhesive (CAA) applied between them. The reason for the selection of this problem is that both polymers are frequently used in the biomedical industry for their properties, and they need to be joined firmly in biomedical devices, and the cyanoacrylate adhesive is the adhesive traditionally used for fluoropolymers, in this case the ETFE, and the same CAA has also shown good adhesion with ABS. However, the strength of the bond for the triplet ETFE-CAA-ABS has not been reported and the improvement of the strength of the bond with surface treatments is not found in scholarly journals for modern medical devices such as stents and snares. Both treatments were compared based on the aforementioned design of experiments. The case where ETFE receives no surface treatment serves as the reference. The results indicated that the three factors evaluated (initial drying of the material, temperature of the chemical bath, and immersion time), and their interactions have no significant effect over the tensile load at failure (tensile strength) of the adhesive bond being evaluated. For the air-ionization corona discharge treatment, two factors were evaluated: discharge exposition time and air pressure. The results obtained from this experimental design indicate that there is no significant difference between the levels of the factors evaluated. These results were unexpected as the ranges used were representative of the maximum ranges permissible in manufacturing

  11. Comparison of sodium naphthenate and air-ionization corona discharge as surface treatments for the ethylene-tetrafluoroethylene polymer (ETFE) to improve adhesion between ETFE and acrylonitrile-butadiene-styrene polymer (ABS) in the presence of a cyanoacrylate adhesive (CAA)

    Science.gov (United States)

    Lucía Johanning-Solís, Ana; Stradi-Granados, Benito A.

    2014-09-01

    This study compares two ethylene-tetrafluoroethylene (ETFE) surface activation treatments, namely chemical attack with a solution of sodium naphthenate and plasma erosion via air-ionization corona discharge in order to improve the adhesive properties of the ETFE. An experimental design was prepared for both treatments in order to assess the effect of the treatment characteristics on the tensile load needed to break the bond between the ETFE and the acrylonitrile-butadiene-styrene polymer (ABS) formed with a cyanoacrylate adhesive (CAA) applied between them. The reason for the selection of this problem is that both polymers are frequently used in the biomedical industry for their properties, and they need to be joined firmly in biomedical devices, and the cyanoacrylate adhesive is the adhesive traditionally used for fluoropolymers, in this case the ETFE, and the same CAA has also shown good adhesion with ABS. However, the strength of the bond for the triplet ETFE-CAA-ABS has not been reported and the improvement of the strength of the bond with surface treatments is not found in scholarly journals for modern medical devices such as stents and snares. Both treatments were compared based on the aforementioned design of experiments. The case where ETFE receives no surface treatment serves as the reference. The results indicated that the three factors evaluated (initial drying of the material, temperature of the chemical bath, and immersion time), and their interactions have no significant effect over the tensile load at failure (tensile strength) of the adhesive bond being evaluated. For the air-ionization corona discharge treatment, two factors were evaluated: discharge exposition time and air pressure. The results obtained from this experimental design indicate that there is no significant difference between the levels of the factors evaluated. These results were unexpected as the ranges used were representative of the maximum ranges permissible in manufacturing

  12. Investigation of some properties of Nylon-6 surface treated by corona discharge in helium

    International Nuclear Information System (INIS)

    Dumitrascu, N.; Surdu, S.; Popa, Gh.; Raileanu, D.

    1996-01-01

    In this work an easy and less expensive method of treatment has been used by corona discharge. This allows to modify the surface properties and especially to improve the compatibility of polymers with biological tissue. The Nylon-6 as a test material was chosen. A scanning electron microscope to visualize the morphology of the morphology of the surface and an IR spectrophotometer able to identify the amide groups and other as well, have been used. Morphology of the treated surface by corona discharge emphasis an etching an etching and/or a crosslinking of amorphous domains, generally important to improve the properties as wetting, dyeing, adhesion, etc. Over all treated surface there is significant blood compatible properties without the need of heparinization of surface. The treated surface influences the biological behaviour of micro-organisms, respectively, that surface is a favourable medium for division of cells and may increase their lifetime. (authors)

  13. Chemical intermediate detection following corona discharge on volatile organic compounds: general method using molecular beam techniques

    International Nuclear Information System (INIS)

    He Luning; Sulkes, Mark

    2011-01-01

    Nonthermal plasma (NTP)-based treatments of volatile organic compounds (VOCs) have potential for effective environmental remediation. Theory and experiment that consider the basic science pertaining to discharge events have helped improve NTP remediation outcomes. If direct information on early post-discharge chemical intermediates were also available, it would likely lead to additional improvement in NTP remediation outcomes. To this point, however, experiments yielding direct information on post-NTP VOC intermediates have been limited. An approach using supersonic expansion molecular beam methods offers general promise for detection of post-discharge VOC intermediates. To illustrate the potential utility of these methods, we present mass spectra showing the growth of early products formed when pulsed corona discharges were carried out on toluene in He and then in He with added O 2 . Good general detection of neutral post-discharge species was obtained using 800 nm 150 fs photoionization pulses.

  14. Electrical and optical analysis of fast transient discharges in a pulsed corona pilot unit

    NARCIS (Netherlands)

    Blom, P.P.M.; Smulders, H.W.M.; Heesch, van E.J.M.; Laan, van der P.C.T.

    1997-01-01

    We give a detailed analysis of intense pulsed corona dis charges. CCD movies and current, voltage and energy in put measurements are the basis of the description. The discharges are generated in a 1.5 kW pilot unit, which cre ates pulsed corona discharges energized by 100 kV pulses of 200 us width,

  15. Effect of dc and pulsed corona discharge on DNA and proteins

    International Nuclear Information System (INIS)

    Shvedchikov, A.P.; Polyakova, A.V.; Belousova, E.V.; Ponizovskii, A.Z.; Goncharov, V.A.

    1993-01-01

    The authors have investigated the effect of a d.c. and pulsed corona discharge in air and nitrogen on DNA and albumin films in the temperature range 77-298 K. The authors have shown that upon exposure to a corona discharge and O 3 , the biopolymers are degraded. With a reduction in temperature, the extent of degradation of DNA drops

  16. DC negative corona discharge in atmospheric pressure helium: transition from the corona to the ‘normal’ glow regime

    International Nuclear Information System (INIS)

    Hasan, Nusair; Farouk, Bakhtier; Antao, Dion S

    2014-01-01

    Direct current (dc) negative corona discharges in atmospheric pressure helium are simulated via detailed numerical modeling. Simulations are conducted to characterize the discharges in atmospheric helium for a pin plate electrode configuration. A self-consistent two-dimensional hybrid model is developed to simulate the discharges and the model predictions are validated with experimental measurements. The discharge model considered consists of momentum and energy conservation equations for a multi-component (electrons, ions, excited species and neutrals) gas mixture, conservation equations for each component of the mixture and state relations. A drift–diffusion approximation for the electron and the ion fluxes is used. A model for the external circuit driving the discharge is also considered and solved along with the discharge model. Many of the key features of a negative corona discharge, namely non-linear current–voltage characteristics, spatially flat cathode current density and glow-like discharge in the high current regime are displayed in the predictions. A transition to the ‘normal’ glow discharge from the corona discharge regime is also observed. The transition is identified from the calculated current–voltage characteristic curve and is characterized by the radial growth of the negative glow and the engulfment of the cathode wire. (paper)

  17. Sulphur dioxide (SO2) electrotransfer in electric field generated by corona discharge

    International Nuclear Information System (INIS)

    Wang, Zu-wu; Guo, Jia; Zeng, Han-cai; Ge, Chun-liang; Yu, Jiang

    2007-01-01

    The mechanism of the forming SO 2 negative ions and their electrotransfer in the corona discharge electric field was investigated in this paper. The experimental results showed that SO 2 electrotransfer occurred in the electric field with corona discharge, which had potential applications in removal of SO 2 of the flue gas from coal-fired power plants by electrotransfer. SO 2 electrotransfer was enhanced by higher electric-field intensity or a larger discharging area. Assistant uniform electric field after the corona discharge electric field would improve SO 2 electrotransfer. The increment of the desulphurization efficiency by SO 2 electrotransfer might reach as high as 50%. (author)

  18. Numerical modelling of ozone production in a wire-cylinder corona discharge and comparison with a wire-plate corona discharge

    International Nuclear Information System (INIS)

    Wang Pengxiang; Chen Junhong

    2009-01-01

    The effect of electrode configuration on ozone production in the direct-current corona discharge of dry and humid air is studied by a numerical model that combines the electron distribution in the corona plasma, plasma chemistry and transport phenomena. Two electrode configurations are considered: wire-cylinder discharge with air flowing along the wire axis and wire-plate discharge with air flowing transverse to the wire. The ozone distributions in both types of discharges are compared. For both electrode configurations, the ozone production rate is higher in the negative corona than in the positive corona and it decreases with an increase in relative humidity. More importantly, the detailed ozone distribution in the neighbourhood of the discharge wire, together with the ozone kinetics, reveals the possible difference in the ozone production from the two discharges. With the same operating conditions and sufficiently short flow residence time, the ozone production rate is nearly the same for both electrode configurations. When the flow residence time is longer than the characteristic time for homogeneous ozone destruction, the net ozone production is higher in the wire-cylinder discharge than in the wire-plate discharge due to relatively less ozone destruction.

  19. Numerical modelling of ozone production in a wire-cylinder corona discharge and comparison with a wire-plate corona discharge

    Science.gov (United States)

    Wang, Pengxiang; Chen, Junhong

    2009-02-01

    The effect of electrode configuration on ozone production in the direct-current corona discharge of dry and humid air is studied by a numerical model that combines the electron distribution in the corona plasma, plasma chemistry and transport phenomena. Two electrode configurations are considered: wire-cylinder discharge with air flowing along the wire axis and wire-plate discharge with air flowing transverse to the wire. The ozone distributions in both types of discharges are compared. For both electrode configurations, the ozone production rate is higher in the negative corona than in the positive corona and it decreases with an increase in relative humidity. More importantly, the detailed ozone distribution in the neighbourhood of the discharge wire, together with the ozone kinetics, reveals the possible difference in the ozone production from the two discharges. With the same operating conditions and sufficiently short flow residence time, the ozone production rate is nearly the same for both electrode configurations. When the flow residence time is longer than the characteristic time for homogeneous ozone destruction, the net ozone production is higher in the wire-cylinder discharge than in the wire-plate discharge due to relatively less ozone destruction.

  20. Breakdown of methylene blue and methyl orange by pulsed corona discharge

    NARCIS (Netherlands)

    Grabowski, L.R.; Veldhuizen, van E.M.; Pemen, A.J.M.; Rutgers, W.R.

    2007-01-01

    The recently developed corona above water technique is applied to water containing 10 mg l-1 methylene blue (MB) or methyl orange (MO). The corona discharge pulses are created with a spark gap switched capacitor followed by a transmission line transformer. The pulse amplitude is 40 kV; its duration

  1. Effect of corona discharge plasma jet on surface-borne microorganisms and sprouting of broccoli seeds.

    Science.gov (United States)

    Kim, Je-Wook; Puligundla, Pradeep; Mok, Chulkyoon

    2017-01-01

    Different pathogenic microorganisms have been reported to cause sprouts-associated outbreaks. In order to sterilise and enhance the germination of seeds, non-thermal plasma has been increasingly investigated in the field of agricultural science as an alternative to the traditional pre-sowing seed treatments. This work aimed to evaluate the effect of corona discharge plasma jet (CDPJ) on disinfection of the natural bio-contaminants of broccoli seed and also studied the plasma effect on sprout seed germination rate and physico-chemical properties of sprouts. Aerobic bacteria, moulds and yeasts, B. cereus, E. coli, Salmonella spp. were detected on the broccoli seed surface. After 0-3 min treatment using CDPJ, the detected microorganisms were reduced in the range of 1.2-2.3 log units. Inactivation patterns were better explained using pseudo-first-order kinetics. The plasma treatment of seeds up to 2 min exhibited a positive effect on germination rate, seedling growth. The physico-chemical and sensory characteristics of sprouts were unaffected due to the CDPJ treatment of their respective seeds. Corona discharge plasma jet can potentially be used for microbial decontamination of broccoli seeds. In addition, the plasma treatment of broccoli sprout seeds has enabled a significant enhancement in their germination rate and seedling growth without compromising physico-chemical and sensory characteristics of their corresponding sprouts. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  2. Food waste management using an electrostatic separator with corona discharge

    Science.gov (United States)

    Lai, Koonchun; Lim, Sooking; Teh, Pehchiong

    2015-05-01

    In Malaysia, municipal solid waste contains a high portion of organic matters, typically contributed by food waste. It is estimated that about 45% of the municipal waste are food waste, followed by the non-food waste such as plastics, metals, glass and others. Food waste, while being properly sorted and contamination free from non-food waste, can be reused (e.g. fertiliser) instead of being landfilled. Therefore, recycling of food waste is crucial not only from the view point of waste management, but also with respect to the reduction of resource losses and greenhouse gases emission. A new waste separation process involved food particles, non-food particles and electrostatic discharge was investigated in this study. The empirical results reveal that the corona electrostatic separation is an environmental-friendly way in recovering foods from municipal waste. The efficiency of the separator, under same operating conditions, varies with the particle size of the food and non-food particles. The highest efficiency of 82% is recorded for the particle sizes between 1.5 and 3.0 mm.

  3. Food waste management using an electrostatic separator with corona discharge

    International Nuclear Information System (INIS)

    Lai, Koonchun; Teh, Pehchiong; Lim, Sooking

    2015-01-01

    In Malaysia, municipal solid waste contains a high portion of organic matters, typically contributed by food waste. It is estimated that about 45% of the municipal waste are food waste, followed by the non-food waste such as plastics, metals, glass and others. Food waste, while being properly sorted and contamination free from non-food waste, can be reused (e.g. fertiliser) instead of being landfilled. Therefore, recycling of food waste is crucial not only from the view point of waste management, but also with respect to the reduction of resource losses and greenhouse gases emission. A new waste separation process involved food particles, non-food particles and electrostatic discharge was investigated in this study. The empirical results reveal that the corona electrostatic separation is an environmental-friendly way in recovering foods from municipal waste. The efficiency of the separator, under same operating conditions, varies with the particle size of the food and non-food particles. The highest efficiency of 82% is recorded for the particle sizes between 1.5 and 3.0 mm

  4. Towards metals analysis using corona discharge ionization ion mobility spectrometry.

    Science.gov (United States)

    Jafari, Mohammad T; Saraji, Mohammad; Sherafatmand, Hossein

    2016-02-25

    For the first time, the capability of corona discharge ionization ion mobility spectrometry (CD-IMS) in the determination of metal complex was evaluated. The extreme simplicity of dispersive liquid-liquid microextraction (DLLME) coupled to the high sensitivity of CD-IMS measurement could make this combination really useful for simple, rapid, and sensitive determination of metals in different samples. In this regard, mercury, as a model metal, was complexed with diethyldithiocarbamate (DEDTC), and then extracted into the carbon tetrachloride using DLLME. Some parameters affecting the extraction efficiency, including the type and volume of the extraction solvent, the type and volume of the disperser solvent, the concentration of the chelating agent, salt addition and, pH were exhaustively investigated. Under the optimized condition, the enrichment factor was obtained to be 142. The linear range of 0.035-10.0 μg mL(-1) with r(2) = 0.997 and the detection limit of 0.010 μg mL(-1) were obtained. The relative standard deviation values were calculated to be lower than 4% and 8% for intra-day and inter-day, respectively. Finally, the developed method was successfully applied for the extraction and determination of mercury in various real samples. The satisfactory results revealed the capability of the proposed method in trace analysis without tedious derivatization or hydride generation. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Food waste management using an electrostatic separator with corona discharge

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Koonchun; Teh, Pehchiong [Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman (Malaysia); Lim, Sooking [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman (Malaysia)

    2015-05-15

    In Malaysia, municipal solid waste contains a high portion of organic matters, typically contributed by food waste. It is estimated that about 45% of the municipal waste are food waste, followed by the non-food waste such as plastics, metals, glass and others. Food waste, while being properly sorted and contamination free from non-food waste, can be reused (e.g. fertiliser) instead of being landfilled. Therefore, recycling of food waste is crucial not only from the view point of waste management, but also with respect to the reduction of resource losses and greenhouse gases emission. A new waste separation process involved food particles, non-food particles and electrostatic discharge was investigated in this study. The empirical results reveal that the corona electrostatic separation is an environmental-friendly way in recovering foods from municipal waste. The efficiency of the separator, under same operating conditions, varies with the particle size of the food and non-food particles. The highest efficiency of 82% is recorded for the particle sizes between 1.5 and 3.0 mm.

  6. Pulsed corona discharge: the role of ozone and hydroxyl radical in aqueous pollutants oxidation.

    Science.gov (United States)

    Preis, S; Panorel, I C; Kornev, I; Hatakka, H; Kallas, J

    2013-01-01

    Ozone and hydroxyl radical are the most active oxidizing species in water treated with gas-phase pulsed corona discharge (PCD). The ratio of the species dependent on the gas phase composition and treated water contact surface was the objective for the experimental research undertaken for aqueous phenol (fast reaction) and oxalic acid (slow reaction) solutions. The experiments were carried out in the reactor, where aqueous solutions showered between electrodes were treated with 100-ns pulses of 20 kV voltage and 400 A current amplitude. The role of ozone increased with increasing oxygen concentration and the oxidation reaction rate. The PCD treatment showed energy efficiency surpassing that of conventional ozonation.

  7. Dynamic characteristics of corona discharge generated under rainfall condition on AC charged conductors

    Science.gov (United States)

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

    2017-12-01

    By synchronous measurement of corona current and the water droplet deformation process on a conductor surface, different types of corona discharge are visualized when AC voltage is applied on a line-ground electrode system. The corona characteristics are closely related to the applied voltage and water supply rate. With the increase of AC voltage, the positive Taylor cone discharge firstly appears and then disappears, replaced by the dripping and crashing discharge. Furthermore, the number of pulses in each pulse train increases with the increase of applied voltage. The mechanism of the transfer from the positive Taylor cone discharge to the dripping and crashing discharge is found to be related to the oscillation process of the water droplet. The water supply rate also has a great influence on the characteristics of corona currents. The number of positive pulse trains increases linearly when the water supply rate gets larger, leading to a higher audible noise and radio interference level from the AC corona, which is quite different from that of the DC corona. The difference between the AC and DC coronas under rainfall conditions is analyzed finally.

  8. FTIR study of decomposition of carbon dioxide in dc corona discharges

    International Nuclear Information System (INIS)

    Horvath, G; Skalny, J D; Mason, N J

    2008-01-01

    The decomposition rate of carbon dioxide and the generation of ozone and carbon monoxide in coaxial corona discharges fed by pure CO 2 has been investigated in a dc corona discharge operated in both positive and negative polarities using FTIR spectroscopy. The degree of CO 2 decomposition is found to be dependent on the voltage, U, with a maximum CO 2 decomposition of nearly 10% found in a negative corona discharge for U = 7.5 kV. In all cases the amount of CO 2 decomposition was lower in positive polarity discharges than in negative polarity discharges operated under same conditions. CO and ozone were found to be the main products observed in the discharges.

  9. FTIR study of decomposition of carbon dioxide in dc corona discharges

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, G; Skalny, J D [Department of Experimental Physics, Comenius University, Mlynska dolina F-2, 842 48, Bratislava (Slovakia); Mason, N J [Open University, Department of Physics and Astronomy, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2008-11-21

    The decomposition rate of carbon dioxide and the generation of ozone and carbon monoxide in coaxial corona discharges fed by pure CO{sub 2} has been investigated in a dc corona discharge operated in both positive and negative polarities using FTIR spectroscopy. The degree of CO{sub 2} decomposition is found to be dependent on the voltage, U, with a maximum CO{sub 2} decomposition of nearly 10% found in a negative corona discharge for U = 7.5 kV. In all cases the amount of CO{sub 2} decomposition was lower in positive polarity discharges than in negative polarity discharges operated under same conditions. CO and ozone were found to be the main products observed in the discharges.

  10. Corona discharge secondary ionization of laser desorbed neutral molecules from a liquid matrix at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Turney, Kevin [Department of Chemistry, University of Florida, Gainesville, Florida 32611 (United States); Harrison, W.W. [Department of Chemistry, University of Florida, Gainesville, Florida 32611 (United States)]. E-mail: harrison@chem.ufl.edu

    2006-06-15

    Matrix assisted laser desorption/ionization (MALDI) is studied at atmospheric pressure using liquid sampling methods. A time-of-flight mass spectrometer couples to an open sample stage accessed by a UV laser for desorption and ionization. Also coupled to the sampling state is a corona discharge for auxiliary ionization of desorbed neutral molecules. The interaction of the laser desorption and corona ionization is studied for a range of desorption conditions, showing enhanced analyte ionization, but the effect is analytically advantageous only at low desorption rates. The effect of corona discharge voltage was also explored. The decoupling of neutral molecule formation and subsequent ionization provides an opportunity to study each process separately.

  11. Corona discharge secondary ionization of laser desorbed neutral molecules from a liquid matrix at atmospheric pressure

    International Nuclear Information System (INIS)

    Turney, Kevin; Harrison, W.W.

    2006-01-01

    Matrix assisted laser desorption/ionization (MALDI) is studied at atmospheric pressure using liquid sampling methods. A time-of-flight mass spectrometer couples to an open sample stage accessed by a UV laser for desorption and ionization. Also coupled to the sampling state is a corona discharge for auxiliary ionization of desorbed neutral molecules. The interaction of the laser desorption and corona ionization is studied for a range of desorption conditions, showing enhanced analyte ionization, but the effect is analytically advantageous only at low desorption rates. The effect of corona discharge voltage was also explored. The decoupling of neutral molecule formation and subsequent ionization provides an opportunity to study each process separately

  12. Multiscale simulation of DC corona discharge and ozone generation from nanostructures

    Science.gov (United States)

    Wang, Pengxiang

    Atmospheric direct current (dc) corona discharge from micro-sized objects has been widely used as an ion source in many devices, such as photocopiers, laser printers, and electronic air cleaners. Shrinking the size of the discharge electrode to the nanometer range (e.g., through the use of carbon nanotubes or CNTs) is expected to lead to a significant reduction in power consumption and detrimental ozone production in these devices. The objectives of this study are to unveil the fundamental physics of the nanoscale corona discharge and to evaluate its performance and ozone production through numerical models. The extremely small size of CNTs presents considerable complexity and challenges in modeling CNT corona discharges. A hybrid multiscale model, which combines a kinetic particle-in-cell plus Monte Carlo collision (PIC-MCC) model and a continuum model, is developed to simulate the corona discharge from nanostructures. The multiscale model is developed in several steps. First, a pure PIC-MCC model is developed and PIC-MCC simulations of corona plasma from micro-sized electrode with same boundary conditions as prior model are performed to validate the PIC-MCC scheme. The agreement between the PIC-MCC model and the prior continuum model indicates the validity of the PIC-MCC scheme. The validated PIC-MCC scheme is then coupled with a continuum model to simulate the corona discharge from a micro-sized electrode. Unlike the prior continuum model which only predicts the corona plasma region, the hybrid model successfully predicts the self-consistent discharge process in the entire corona discharge gap that includes both corona plasma region and unipolar ion region. The voltage-current density curves obtained by the hybrid model agree well with analytical prediction and experimental results. The hybrid modeling approach, which combines the accuracy of a kinetic model and the efficiency of a continuum model, is thus validated for modeling dc corona discharges. For

  13. Experimental Investigation of the Corona Discharge in Electrical Transmission due to AC/DC Electric Fields

    Directory of Open Access Journals (Sweden)

    Fuangpian Phanupong

    2016-01-01

    Full Text Available Nowadays, using of High Voltage Direct Current (HVDC transmission to maximize the transmission efficiency, bulk power transmission, connection of renewable power source from wind farm to the grid is of prime concern for the utility. However, due to the high electric field stress from Direct Current (DC line, the corona discharge can easily be occurred at the conductor surface leading to transmission loss. Therefore, the polarity effect of DC lines on corona inception and breakdown voltage should be investigated. In this work, the effect of DC polarity and Alternating Current (AC field stress on corona inception voltage and corona discharge is investigated on various test objects, such as High Voltage (HV needle, needle at ground plane, internal defect, surface discharge, underground cable without cable termination, cable termination with simulated defect and bare overhead conductor. The corona discharge is measured by partial discharge measurement device with high-frequency current transformer. Finally, the relationship between supply voltage and discharge intensity on each DC polarity and AC field stress can be successfully determined.

  14. Radio and television interference caused by corona discharges from high-voltage transmission lines

    International Nuclear Information System (INIS)

    Sarmadi, M.

    1996-01-01

    Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and atmospheric conditions and generally increases by 10 to 30 dB in foul weather

  15. Pulsed power corona discharges for air pollution control

    NARCIS (Netherlands)

    Smulders, H.W.M.; Heesch, van E.J.M.; Paasen, van S.V.B.

    1998-01-01

    Successful introduction of pulsed corona for industrial purposes very much depends on the reliability of high-voltage and pulsed power technology and on the efficiency of energy transfer. In addition, it is of the utmost importance that adequate electromagnetic compatibility (EMC) is achieved

  16. Greener corona discharge for enhanced wind generation with a simple dip-coated carbon nanotube decoration

    Science.gov (United States)

    Wu, Yishan; Li, Jun; Ye, Jianchun; Chen, Xiaohong; Li, Huili; Huang, Sumei; Zhao, Ran; Ou-Yang, Wei

    2017-10-01

    Corona discharge-induced wind (CDIW) has been widely utilized in production lines in the food and semiconductor industries and in indoor devices such as electrostatic precipitators. Some ozone is inevitably emitted, posing serious health risks to respiratory system and lung function of a human being. In this work, a greener corona discharge with enhanced wind generation for a needle-to-cylinder discharge structure is demonstrated using a simple dip-coating method to attach carbon nanotubes (CNTs) to the discharge electrode of a stainless steel needle. Compared with a conventional discharge electrode without CNT decoration, the velocity of the CDIW is greatly enhanced, the onset voltage is lowered, the energy conversion efficiency is greatly improved and the concentration of generated ozone is much reduced, making this easy method of CNT decoration a promising candidate for greener corona discharge systems. In addition, several impact factors for improved performance are discussed mathematically and phenomenologically, providing an insight into the corona discharge and wind generation.

  17. Greener corona discharge for enhanced wind generation with a simple dip-coated carbon nanotube decoration

    International Nuclear Information System (INIS)

    Wu, Yishan; Ye, Jianchun; Chen, Xiaohong; Li, Huili; Huang, Sumei; Zhao, Ran; Ou-Yang, Wei; Li, Jun

    2017-01-01

    Corona discharge-induced wind (CDIW) has been widely utilized in production lines in the food and semiconductor industries and in indoor devices such as electrostatic precipitators. Some ozone is inevitably emitted, posing serious health risks to respiratory system and lung function of a human being. In this work, a greener corona discharge with enhanced wind generation for a needle-to-cylinder discharge structure is demonstrated using a simple dip-coating method to attach carbon nanotubes (CNTs) to the discharge electrode of a stainless steel needle. Compared with a conventional discharge electrode without CNT decoration, the velocity of the CDIW is greatly enhanced, the onset voltage is lowered, the energy conversion efficiency is greatly improved and the concentration of generated ozone is much reduced, making this easy method of CNT decoration a promising candidate for greener corona discharge systems. In addition, several impact factors for improved performance are discussed mathematically and phenomenologically, providing an insight into the corona discharge and wind generation. (paper)

  18. Study on law of negative corona discharge in microparticle-air two-phase flow media

    Directory of Open Access Journals (Sweden)

    Bo He

    2016-03-01

    Full Text Available To study the basic law of negative corona discharge in solid particle-air two-phase flow, corona discharge experiments in a needle-plate electrode system at different voltage levels and different wind speed were carried out in the wind tunnel. In this paper, the change law of average current and current waveform were analyzed, and the observed phenomena were systematically explained from the perspectives of airflow, particle charging, and particle motion with the help of PIV (particle image velocity measurements and ultraviolet observations.

  19. Modelling of pulsed RF corona discharges in high-pressure air

    International Nuclear Information System (INIS)

    Auzas, F; Makarov, M; Naidis, G V

    2012-01-01

    An approach to description of pulsed RF corona discharges in high-pressure air is developed, based on the model of a filamentary discharge sustained by an electromagnetic wave guided along the plasma filament. Results of numerical simulation of spatial-temporal discharge dynamics at the quasi-stationary stage are obtained for various values of gas pressure and wave frequency. Experimental data on the discharge length versus the power absorbed by the discharge are presented. Their comparison with simulation results is given. (paper)

  20. A semi-analytical study of positive corona discharge in wire–plane electrode configuration

    International Nuclear Information System (INIS)

    Yanallah, K; Pontiga, F; Chen, J H

    2013-01-01

    Wire-to-plane positive corona discharge in air has been studied using an analytical model of two species (electrons and positive ions). The spatial distributions of electric field and charged species are obtained by integrating Gauss's law and the continuity equations of species along the Laplacian field lines. The experimental values of corona current intensity and applied voltage, together with Warburg's law, have been used to formulate the boundary condition for the electron density on the corona wire. To test the accuracy of the model, the approximate electric field distribution has been compared with the exact numerical solution obtained from a finite element analysis. A parametrical study of wire-to-plane corona discharge has then been undertaken using the approximate semi-analytical solutions. Thus, the spatial distributions of electric field and charged particles have been computed for different values of the gas pressure, wire radius and electrode separation. Also, the two dimensional distribution of ozone density has been obtained using a simplified plasma chemistry model. The approximate semi-analytical solutions can be evaluated in a negligible computational time, yet provide precise estimates of corona discharge variables. (paper)

  1. A semi-analytical study of positive corona discharge in wire-plane electrode configuration

    Science.gov (United States)

    Yanallah, K.; Pontiga, F.; Chen, J. H.

    2013-08-01

    Wire-to-plane positive corona discharge in air has been studied using an analytical model of two species (electrons and positive ions). The spatial distributions of electric field and charged species are obtained by integrating Gauss's law and the continuity equations of species along the Laplacian field lines. The experimental values of corona current intensity and applied voltage, together with Warburg's law, have been used to formulate the boundary condition for the electron density on the corona wire. To test the accuracy of the model, the approximate electric field distribution has been compared with the exact numerical solution obtained from a finite element analysis. A parametrical study of wire-to-plane corona discharge has then been undertaken using the approximate semi-analytical solutions. Thus, the spatial distributions of electric field and charged particles have been computed for different values of the gas pressure, wire radius and electrode separation. Also, the two dimensional distribution of ozone density has been obtained using a simplified plasma chemistry model. The approximate semi-analytical solutions can be evaluated in a negligible computational time, yet provide precise estimates of corona discharge variables.

  2. A semi-analytical stationary model of a point-to-plane corona discharge

    International Nuclear Information System (INIS)

    Yanallah, K; Pontiga, F

    2012-01-01

    A semi-analytical model of a dc corona discharge is formulated to determine the spatial distribution of charged particles (electrons, negative ions and positive ions) and the electric field in pure oxygen using a point-to-plane electrode system. A key point in the modeling is the integration of Gauss' law and the continuity equation of charged species along the electric field lines, and the use of Warburg's law and the corona current–voltage characteristics as input data in the boundary conditions. The electric field distribution predicted by the model is compared with the numerical solution obtained using a finite-element technique. The semi-analytical solutions are obtained at a negligible computational cost, and provide useful information to characterize and control the corona discharge in different technological applications. (paper)

  3. 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.

  4. Transformation of soybean Gy3 gene into Artemisaarenaria mediated by corona discharge

    International Nuclear Information System (INIS)

    Chao, Lu-meng; Na, Ri; Xue, Dan; Xu, Yongze; Liu, Teng

    2013-01-01

    In order to improve the protein content of desert plant, a method of genetic transformation mediated by corona discharge was established. Artemisia seeds were processed in corona electric field for 120 min at 12 kV, and then soaked in 0.1 SSC media that contained Soybean Gy3 gene DNA to incubate for 12 h at 26 °C. Finally the seeds were inoculated on the differentiation medium. Polymerase Chain Reaction (PCR) and Reverse Transcription Polymerase Chain Reaction (RT-PCR) detection showed that the Soybean Gy3 gene had been successfully introduced into genomic DNA of the regenerated plants of Artemisaarenaria. The study provided a new way for corona discharge in plant genetic modification.

  5. Efficiency of ozone production by pulsed positive corona discharge in synthetic air

    Czech Academy of Sciences Publication Activity Database

    Šimek, Milan; Člupek, Martin

    2002-01-01

    Roč. 35, č. 11 (2002), s. 1171-1175 ISSN 0022-3727 R&D Projects: GA AV ČR IAA1043102; GA ČR GA202/99/1298 Institutional research plan: CEZ:AV0Z2043910 Keywords : corona, synthetic air Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.366, year: 2002

  6. Ozone generation by negative corona discharge: the effect of Joule heating

    Energy Technology Data Exchange (ETDEWEB)

    Yanallah, K; Castellanos, A [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla (Spain); Pontiga, F; Fernandez-Rueda, A [Departamento de Fisica Aplicada II, Universidad de Sevilla (Spain); Belasri, A [Laboratoire de Physique des Plasmas, des Materiaux Conducteur et Leurs Applications, Universite d' Oran (Algeria)

    2008-10-07

    Ozone generation in pure oxygen using a wire-to-cylinder corona discharge reactor is experimentally and numerically investigated. Ozone concentration is determined by means of direct UV spectroscopy and the effects of Joule heating and ozone decomposition on the electrodes are analysed for different discharge gaps. The numerical model combines the physical processes in the corona discharge with the chemistry of ozone formation and destruction. The chemical kinetics model and the electrical model are coupled through Poisson's equation, and the current-voltage (CV) characteristic measured in experiments is used as input data to the numerical simulation. The numerical model is able to predict the radial distributions of electrons, ions, atoms and molecules for each applied voltage of the CV characteristic. In particular, the evolution of ozone density inside the discharge cell has been investigated as a function of current intensity and applied voltage.

  7. Ozone generation by negative corona discharge: the effect of Joule heating

    International Nuclear Information System (INIS)

    Yanallah, K; Castellanos, A; Pontiga, F; Fernandez-Rueda, A; Belasri, A

    2008-01-01

    Ozone generation in pure oxygen using a wire-to-cylinder corona discharge reactor is experimentally and numerically investigated. Ozone concentration is determined by means of direct UV spectroscopy and the effects of Joule heating and ozone decomposition on the electrodes are analysed for different discharge gaps. The numerical model combines the physical processes in the corona discharge with the chemistry of ozone formation and destruction. The chemical kinetics model and the electrical model are coupled through Poisson's equation, and the current-voltage (CV) characteristic measured in experiments is used as input data to the numerical simulation. The numerical model is able to predict the radial distributions of electrons, ions, atoms and molecules for each applied voltage of the CV characteristic. In particular, the evolution of ozone density inside the discharge cell has been investigated as a function of current intensity and applied voltage

  8. Ozone generation by negative corona discharge: the effect of Joule heating

    Science.gov (United States)

    Yanallah, K.; Pontiga, F.; Fernández-Rueda, A.; Castellanos, A.; Belasri, A.

    2008-10-01

    Ozone generation in pure oxygen using a wire-to-cylinder corona discharge reactor is experimentally and numerically investigated. Ozone concentration is determined by means of direct UV spectroscopy and the effects of Joule heating and ozone decomposition on the electrodes are analysed for different discharge gaps. The numerical model combines the physical processes in the corona discharge with the chemistry of ozone formation and destruction. The chemical kinetics model and the electrical model are coupled through Poisson's equation, and the current-voltage (CV) characteristic measured in experiments is used as input data to the numerical simulation. The numerical model is able to predict the radial distributions of electrons, ions, atoms and molecules for each applied voltage of the CV characteristic. In particular, the evolution of ozone density inside the discharge cell has been investigated as a function of current intensity and applied voltage.

  9. Comparison of toluene removal in air at atmospheric conditions by different corona discharges.

    Science.gov (United States)

    Schiorlin, Milko; Marotta, Ester; Rea, Massimo; Paradisi, Cristina

    2009-12-15

    Different types of corona discharges, produced by DC of either polarity (+/-DC) and positive pulsed (+pulsed) high voltages, were applied to the removal of toluene via oxidation in air at room temperature and atmospheric pressure. Mechanistic insight was obtained through comparison of the three different corona regimes with regard to process efficiency, products, response to the presence of humidity and, for DC coronas, current/voltage characteristics coupled with ion analysis. Process efficiency increases in the order +DC toluene conversion and product selectivity were achieved, CO(2) and CO accounting for about 90% of all reacted carbon. Ion analysis, performed by APCI-MS (Atmospheric Pressure Chemical Ionization-Mass Spectrometry), provides a powerful rationale for interpreting current/voltage characteristics of DC coronas. All experimental findings are consistent with the proposal that in the case of +DC corona toluene oxidation is initiated by reactions with ions (O(2)(+*), H(3)O(+) and their hydrates, NO(+)) both in dry as well as in humid air. In contrast, with -DC no evidence is found for any significant reaction of toluene with negative ions. It is also concluded that in humid air OH radicals are involved in the initial stage of toluene oxidation induced both by -DC and +pulsed corona.

  10. Removal of styrene vapor from atmospheric air using a pulsed corona discharge and UV-irridiation

    International Nuclear Information System (INIS)

    Shvedchikov, A.P.; Belousova, E.V.; Polyakova, A.V.; Ponizovskii, A.Z.; Goncharov, V.A.

    1993-01-01

    The authors have investigated processes for removal of styrene vapor from atmospheric air (volume content 0.007-0.06%) upon exposure to UV radiation and dc and pulsed corona discharges. The authors have studied the dependence of the degree of purification on various parameters (flow rate, temperature, composition, pulse frequency). It has been shown that the purification rate increases when UV radiation is combined with the discharge. A possible mechanism for the purification process is considered

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  12. Removal of iodomethane from air using a plot-scale corona discharge scrubber

    International Nuclear Information System (INIS)

    Dickson, L.W.; Toft-Hall, A.; Torgerson, D.F.

    1985-12-01

    This report presents the results of a study of the removal of iodomethane from air using a pilot-scale corona discharge scrubber. The removal was measured in the following parameter ranges: bulk air flow, 30 to 350 m 3 /h; initial CH 3 I concentration, 6 to 230 μmol/m 3 ; and discharge current, 0 to 75 mA DC (negative polarity). Approximately five to ten moles of iodomethane are removed per mole of electrons added to the air stream at a discharge voltage of ∼ 10 kV. This removal efficiency suggests that both ion-molecule and radical-molecule reactions may be important in the removal of iodomethane from air in a corona discharge. The results of this pilot-scale demonstration indicate that a corona discharge scrubber would be suitable for removing iodine species from air as part of the emergency filtered-air discharge system of a nuclear reactor. The application of this technology to the control of nitrogen oxide, sulfur dioxide and hydrogen sulfide emissions is being investigated. 15 refs

  13. A morphological study of the changes in the ultrastructure of a bacterial biofilm disrupted by an ac corona discharge in air

    Energy Technology Data Exchange (ETDEWEB)

    Stepanova, Olga, E-mail: o.m.stepanova@spbu.ru; Astafiev, Alexander; Kudryavtsev, Anatoly [Physical Faculty, Saint Petersburg State University, St. Petersburg (Russian Federation); Rybalchenko, Oksana; Orlova, Olga; Kapustina, Valentina [Faculty of Medicine, Saint Petersburg State University, St. Petersburg (Russian Federation)

    2016-08-14

    The morphology of bacterial cells and biofilms subjected to a low frequency (∼10{sup 5} Hz) ac (∼10{sup −1} A) corona discharge was investigated using electron microscopy. A low-frequency ac corona discharge in air is shown to have a bactericidal and bacteriostatic effect on Escherichia coli M17 culture at both the cellular and population levels. Corona exposure inhibits the formation of a microbial community and results in the destruction of formed biofilms. This paper presents data on changes in the ultrastructure of cells and biofilms after corona treatment. Our results suggest that the E. coli M17 cells inside biofilms are affected with results similar to sub-lethal and lethal thermal exposure. Some of the biological aspects of colony and biofilm cells death are evaluated. Morphological changes in the ultrastructure of the biofilms under corona treatment are described. Our results indicate that the heating effect is the main factor responsible for the corona-induced inactivation of bacteria.

  14. A morphological study of the changes in the ultrastructure of a bacterial biofilm disrupted by an ac corona discharge in air

    International Nuclear Information System (INIS)

    Stepanova, Olga; Astafiev, Alexander; Kudryavtsev, Anatoly; Rybalchenko, Oksana; Orlova, Olga; Kapustina, Valentina

    2016-01-01

    The morphology of bacterial cells and biofilms subjected to a low frequency (∼10"5 Hz) ac (∼10"−"1 A) corona discharge was investigated using electron microscopy. A low-frequency ac corona discharge in air is shown to have a bactericidal and bacteriostatic effect on Escherichia coli M17 culture at both the cellular and population levels. Corona exposure inhibits the formation of a microbial community and results in the destruction of formed biofilms. This paper presents data on changes in the ultrastructure of cells and biofilms after corona treatment. Our results suggest that the E. coli M17 cells inside biofilms are affected with results similar to sub-lethal and lethal thermal exposure. Some of the biological aspects of colony and biofilm cells death are evaluated. Morphological changes in the ultrastructure of the biofilms under corona treatment are described. Our results indicate that the heating effect is the main factor responsible for the corona-induced inactivation of bacteria.

  15. Preliminary experiments on the growth of plants exposed to DC corona discharge in a hydroponics. Chokuryu corona hodenkadeno suiko sanbaini yoru shokubutsu seiikuno yobiteki kento

    Energy Technology Data Exchange (ETDEWEB)

    Shigemitsu, Tsukasa; Watanabe, Yasunori

    1988-01-01

    For the purpose of utilizing electrical phenomena to agriculture fields, preliminary experiments were carried out hydroponically to evaluate especially the effects of ion by DC corona discharge on the growth of plants such as lettuce or radish. The influences of various shapes of discharge electrodes on a water evaporation rate, ozone production rate and ion current change were studied, and the indirect stimulation effects on plants by more water evaporation under discharge, and the direct stimulation effects on plants with discharge by the electrode fixed 45cm above plants were studied. As a result, the water evaporation rate was 2 or 3 times more than that of control plots by positive or negative corona discharge, however, for the growth of plants, no remarkable direct or indirect stimulation effects by discharge were observed. As subjects, the clarification of water behavior change under discharge and of effects on plants in cellular level were pointed out to be necessary. (14 figs, 12 tabs, 12 refs)

  16. Ozone generation in positive and negative corona discharge fed by humid oxygen and carbon dioxide

    International Nuclear Information System (INIS)

    Skalny, J D; Orszagh, J; MatejcIk, S; Mason, N J

    2008-01-01

    The effect of humidity on ozone generation of positive and negative corona discharges fed by O 2 and CO 2 has been studied in the humidity range of 100-20 000 ppm. The experiments were carried out at an ambient temperature and pressure of 100 kPa. The increase in humidity of CO 2 conspicuously suppressed the ozone generation in negative corona discharge at all values of the input energy densities into the discharge. The effect was less pronounced in oxygen. In contrast to decrease of ozone concentration observed in negative corona discharge, the presence of water both in O 2 and CO 2 acts catalytically. The ozone concentration has been found to increase remarkably (approximately 10 times) in oxygen, if the humidity was increased from 100 to 20 000 ppm. The dependence of ozone concentration on the gas humidity exhibited an extreme. The increase observed at humidity up to approximately 5000 ppm was followed by the marginal reduction in ozone concentration. Anyway, the values of this were considerably higher than those found in dry CO 2 . The effect of humidity on ozone concentration will be discussed in relation to plasma chemical processes in studied discharges and their macroscopic parameters.

  17. Method for measuring the stochastic properties of corona and partial-discharge pulses

    International Nuclear Information System (INIS)

    Van Brunt, R.J.; Kulkarni, S.V.

    1989-01-01

    A new method is described for measuring the stochastic behavior of corona and partial-discharge pulses which utilizes a pulse selection and sorting circuit in conjunction with a computer-controlled multichannel analyzer to directly measure various conditional and unconditional pulse-height and pulse-time-separation distributions. From these measured distributions it is possible to determine the degree of correlation between successive discharge pulses. Examples are given of results obtained from measurements on negative, point-to-plane (Trichel-type) corona pulses in a N 2 /O 2 gas mixture which clearly demonstrate that the phenomenon is inherently stochastic in the sense that development of a discharge pulse is significantly affected by the amplitude of and time separation from the preceding pulse. It is found, for example, that corona discharge pulse amplitude and time separation from an earlier pulse are not independent random variables. Discussions are given about the limitations of the method, sources of error, and data analysis procedures required to determine self-consistency of the various measured distributions

  18. Ozone production by corona discharges during a convective event in DISCOVER-AQ Houston

    Science.gov (United States)

    Kotsakis, Alexander; Morris, Gary A.; Lefer, Barry; Jeon, Wonbae; Roy, Anirban; Minschwaner, Ken; Thompson, Anne M.; Choi, Yunsoo

    2017-07-01

    An ozonesonde launched near electrically active convection in Houston, TX on 5 September 2013 during the NASA DISCOVER-AQ project measured a large enhancement of ozone throughout the troposphere. A separate ozonesonde was launched from Smith Point, TX (∼58 km southeast of the Houston site) at approximately the same time as the launch from Houston and did not measure that enhancement. Furthermore, ozone profiles for the descent of both sondes agreed well with the ascending Smith Point profile, suggesting a highly localized event in both space and time in which an anomalously large enhancement of 70-100 ppbv appeared in the ascending Houston ozonesonde data. Compared to literature values, such an enhancement appears to be the largest observed to date. Potential sources of the localized ozone enhancement such as entrainment of urban or biomass burning emissions, downward transport from the stratosphere, photochemical production from lightning NOx, and direct ozone production from corona discharges were investigated using model simulations. We conclude that the most likely explanation for the large ozone enhancement is direct ozone production by corona discharges. Integrating the enhancement seen in the Houston ozone profile and using the number of electrical discharges detected by the NLDN (or HLMA), we estimate a production of 2.48 × 1028 molecules of ozone per flash which falls within the range of previously recorded values (9.89 × 1026-9.82 × 1028 molecules of ozone per flash). Since there is currently no parameterization for the direct production of ozone from corona discharges we propose the implementation of an equation into a chemical transport model. Ultimately, additional work is needed to further understand the occurrence and impact of corona discharges on tropospheric chemistry on short and long timescales.

  19. Electro-Hydrodynamics and Kinetic Modeling of Dry and Humid Air Flows Activated by Corona Discharges

    Science.gov (United States)

    P. Sarrette, J.; Eichwald, O.; Marchal, F.; Ducasse, O.; Yousfi, M.

    2016-05-01

    The present work is devoted to the 2D simulation of a point-to-plane Atmospheric Corona Discharge Reactor (ACDR) powered by a DC high voltage supply. The corona reactor is periodically crossed by thin mono filamentary streamers with a natural repetition frequency of some tens of kHz. The study compares the results obtained in dry air and in air mixed with a small amount of water vapour (humid air). The simulation involves the electro-dynamics, chemical kinetics and neutral gas hydrodynamics phenomena that influence the kinetics of the chemical species transformation. Each discharge lasts about one hundred of a nanosecond while the post-discharge occurring between two successive discharges lasts one hundred of a microsecond. The ACDR is crossed by a lateral dry or humid air flow initially polluted with 400 ppm of NO. After 5 ms, the time corresponding to the occurrence of 50 successive discharge/post-discharge phases, a higher NO removal rate and a lower ozone production rate are found in humid air. This change is due to the presence of the HO2 species formed from the H primary radical in the discharge zone.

  20. Experimental investigation and numerical modelling of positive corona discharge: ozone generation

    Energy Technology Data Exchange (ETDEWEB)

    Yanallah, K; Castellanos, A [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla (Spain); Pontiga, F; Fernandez-Rueda, A [Departamento de FIsica Aplicada II, Universidad de Sevilla (Spain)

    2009-03-21

    The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

  1. Experimental investigation and numerical modelling of positive corona discharge: ozone generation

    International Nuclear Information System (INIS)

    Yanallah, K; Castellanos, A; Pontiga, F; Fernandez-Rueda, A

    2009-01-01

    The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

  2. Experimental investigation and numerical modelling of positive corona discharge: ozone generation

    Science.gov (United States)

    Yanallah, K; Pontiga, F; Fernández-Rueda, A; Castellanos, A

    2009-03-01

    The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

  3. Dimensional analysis of detrimental ozone generation by positive wire-to-plate corona discharge in air

    Science.gov (United States)

    Bo, Z.; Chen, J. H.

    2010-02-01

    The dimensional analysis technique is used to formulate a correlation between ozone generation rate and various parameters that are important in the design and operation of positive wire-to-plate corona discharges in indoor air. The dimensionless relation is determined by linear regression analysis based on the results from 36 laboratory-scale experiments. The derived equation is validated by experimental data and a numerical model published in the literature. Applications of such derived equation are illustrated through an example selection of the appropriate set of operating conditions in the design/operation of a photocopier to follow the federal regulations of ozone emission. Finally, a new current-voltage characteristic equation is proposed for positive wire-to-plate corona discharges based on the derived dimensionless equation.

  4. Dimensional analysis of detrimental ozone generation by positive wire-to-plate corona discharge in air

    International Nuclear Information System (INIS)

    Bo, Z; Chen, J H

    2010-01-01

    The dimensional analysis technique is used to formulate a correlation between ozone generation rate and various parameters that are important in the design and operation of positive wire-to-plate corona discharges in indoor air. The dimensionless relation is determined by linear regression analysis based on the results from 36 laboratory-scale experiments. The derived equation is validated by experimental data and a numerical model published in the literature. Applications of such derived equation are illustrated through an example selection of the appropriate set of operating conditions in the design/operation of a photocopier to follow the federal regulations of ozone emission. Finally, a new current-voltage characteristic equation is proposed for positive wire-to-plate corona discharges based on the derived dimensionless equation.

  5. A Compact Source of Flash-Corona Discharge for Biomedical Applications

    Science.gov (United States)

    Moshkunov, S. I.; Khomich, V. Yu.; Shershunova, E. A.

    2018-01-01

    A compact source of low-temperature plasma for biological and medical applications is proposed, which operates at kilohertz frequencies in the regime of flash-corona discharge with an energy of 0.1 mJ/pulse. The plasma source was tested in application to plasma pretreatment of green salad seeds. Plasma-treated seeds exhibited increased (by about 25%) germination speed as compared to that in the untreated control.

  6. Experimental study of the polymer powder film thickness uniformity produced by the corona discharge

    Science.gov (United States)

    Fazlyyyakhmatov, Marsel

    2017-01-01

    The results of an experimental study of the polymer powder film thickness uniformity are presented. Polymer powder films are produced by the electrostatic field of corona discharge. Epoxy and epoxy-polyester powder films with thickness in the range of 30-120 microns are studied. Experimentally confirmed possibility of using these coatings as protective matching layer of piezoceramic transducers at frequencies of 0.5-15 MHz.

  7. Efficiency of ozone production by pulsed positive corona discharge in synthetic air

    Energy Technology Data Exchange (ETDEWEB)

    Simek, Milan [Institute of Plasma Physics, Department of Pulsed Plasma Systems, Academy of Sciences of the Czech Republic, Prague (Czech Republic)]. E-mail: simek@ipp.cas.cz; Clupek, Martin [Institute of Plasma Physics, Department of Pulsed Plasma Systems, Academy of Sciences of the Czech Republic, Prague (Czech Republic)

    2002-06-07

    We have studied the efficiency of ozone production by pulsed positive corona discharge in coaxial wire-cylinder geometry at atmospheric pressure. A corona discharge was generated by short ({approx}150 ns) high voltage pulses applied between a silver coated copper wire anode and stainless steel cylinder cathode in synthetic air. A pyrex probe and Teflon tube was used for collecting discharge products and an ozone concentration was monitored outside of the discharge chamber by a non-dispersive UV absorption technique. The production of ozone was investigated as a function of energy density (10{sup -4}-3x10{sup -1} Wh l{sup -1}) delivered to the discharge volume by combining the discharge frequency (0.1-10 Hz) and airflow rate (1-32 l min{sup -1}). From ozone concentration measurements we have evaluated the ozone production, yield and production energy cost. The ozone production yield and cost vary in the range of 15-55 g kWh{sup -1} and 35-110 eV/molecule. (author)

  8. A high-current rail-type gas switch with preionization by an additional corona discharge

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, E. I.; Belozerov, O. S.; Krastelev, E. G., E-mail: ekrastelev@yandex.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

    2016-12-15

    The characteristics of a high-current rail-type gas switch with preionization of the gas (air) in a spark gap by an additional corona discharge are investigated. The experiments were performed in a voltage range of 10–45 kV using a two-electrode switch consisting of two cylindrical electrodes with a diameter of 22 mm and a length of 100 mm and a set of laterally located corona-discharge needles. The requirements for the position and size of the needles are defined for which a corona discharge is ignited before a breakdown of the main gap and does not change to a sparking form, and the entire length of the rail electrodes is efficiently used. The fulfillment of these requirements ensures stable operation of the switch with a small variation of the pulse breakdown voltage, which is not more than 1% for a fixed voltage-pulse rise time in the range from 150 ns to 3.5 μs. A short delay time of the switch breakdown makes it possible to control the two-electrode switch by an overvoltage pulse of nanosecond duration.

  9. Combined corona discharge and UV photoionization source for ion mobility spectrometry.

    Science.gov (United States)

    Bahrami, Hamed; Tabrizchi, Mahmoud

    2012-08-15

    An ion mobility spectrometer is described which is equipped with two non-radioactive ion sources, namely an atmospheric pressure photoionization and a corona discharge ionization source. The two sources cannot only run individually but are additionally capable of operating simultaneously. For photoionization, a UV lamp was mounted parallel to the axis of the ion mobility cell. The corona discharge electrode was mounted perpendicular to the UV radiation. The total ion current from the photoionization source was verified as a function of lamp current, sample flow rate, and drift field. Simultaneous operation of the two ionization sources was investigated by recording ion mobility spectra of selected samples. The design allows one to observe peaks from either the corona discharge or photoionization individually or simultaneously. This makes it possible to accurately compare peaks in the ion mobility spectra from each individual source. Finally, the instrument's capability for discriminating two peaks appearing in approximately identical drift times using each individual ionization source is demonstrated. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Numerical simulation of Trichel pulses of negative DC corona discharge based on a plasma chemical model

    Science.gov (United States)

    Chen, Xiaoyue; Lan, Lei; Lu, Hailiang; Wang, Yu; Wen, Xishan; Du, Xinyu; He, Wangling

    2017-10-01

    A numerical simulation method of negative direct current (DC) corona discharge based on a plasma chemical model is presented, and a coaxial cylindrical gap is adopted. There were 15 particle species and 61 kinds of collision reactions electrons involved, and 22 kinds of reactions between ions are considered in plasma chemical reactions. Based on this method, continuous Trichel pulses are calculated on about a 100 us timescale, and microcosmic physicochemical process of negative DC corona discharge in three different periods is discussed. The obtained results show that the amplitude of Trichel pulses is between 1-2 mA, and that pulse interval is in the order of 10-5 s. The positive ions produced by avalanche ionization enhanced the electric field near the cathode at the beginning of the pulse, then disappeared from the surface of cathode. The electric field decreases and the pulse ceases to develop. The negative ions produced by attachment slowly move away from the cathode, and the electric field increases gradually until the next pulse begins to develop. The positive and negative ions with the highest density during the corona discharge process are O4+ and O3- , respectively.

  11. A high-current rail-type gas switch with preionization by an additional corona discharge

    International Nuclear Information System (INIS)

    Antipov, E. I.; Belozerov, O. S.; Krastelev, E. G.

    2016-01-01

    The characteristics of a high-current rail-type gas switch with preionization of the gas (air) in a spark gap by an additional corona discharge are investigated. The experiments were performed in a voltage range of 10–45 kV using a two-electrode switch consisting of two cylindrical electrodes with a diameter of 22 mm and a length of 100 mm and a set of laterally located corona-discharge needles. The requirements for the position and size of the needles are defined for which a corona discharge is ignited before a breakdown of the main gap and does not change to a sparking form, and the entire length of the rail electrodes is efficiently used. The fulfillment of these requirements ensures stable operation of the switch with a small variation of the pulse breakdown voltage, which is not more than 1% for a fixed voltage-pulse rise time in the range from 150 ns to 3.5 μs. A short delay time of the switch breakdown makes it possible to control the two-electrode switch by an overvoltage pulse of nanosecond duration.

  12. Improving COIL Efficiency By Iodine Pre-Dissociation Via Corona Discharge In The Transonic Section Of The Secondary Flow

    National Research Council Canada - National Science Library

    Rosenwaks, Zamik; Barmashenko, Boris

    2006-01-01

    ...: We intend to carry out a comprehensive experimental study of I2 pre-dissociation, based on applying corona discharge in the transonic section of the secondary flow in the COIL supersonic nozzle...

  13. Water purification by corona-above-water treatment

    NARCIS (Netherlands)

    Pemen, A.J.M.; Heesch, van E.J.M.; Hoeben, W.F.L.M.

    2012-01-01

    Advanced oxidation technologies (AOT), such as non-thermal plasmas, are considered to be very promising for the purpose of water treatment. The goal of this study is to test the feasibility of "Corona-above-water" technology for the treatment of drinking water. Experiments have been performed on the

  14. Corona discharge experiments in admixtures of N2 and CH4: a laboratory simulation of Titan's atmosphere

    International Nuclear Information System (INIS)

    Horvath, G; Skalny, J D; Klas, M; Zahoran, M; Mason, N J; Vladoiu, R; Manole, M

    2009-01-01

    A positive corona discharge fed by a N 2 : CH 4 mixture (98 : 2) at atmospheric pressure and ambient temperature has been studied as a laboratory mimic of the chemical processes occurring in the atmosphere of Titan, Saturn's largest moon. In situ measurements of UV and IR transmission spectra within the discharge have shown that the main chemical product is C 2 H 2 , produced by dissociation of CH 4 , with small but significant traces of ethane and HCN, all species that have been detected in Titan's atmosphere. A small amount (0.2%) of CH 4 was decomposed after 12 min of treatment requiring an average energy of 2.7 kWh g -1 . After 14 min the discharge was terminated due to the formation of a solid yellow deposit on the central wire electrode. Such a deposit is similar to that observed in other discharges and is believed to be an analogue of the aerosol and dust observed in Titan's atmosphere and is composed of chemical species commonly known as 'tholins'. We have also explored the electrical properties of the discharge. The admixture of methane into nitrogen caused an increase in the onset voltage of the discharge and consequently led to a reduction in the measured discharge current.

  15. Corona-like multistreamer discharge in water for cylindrical shock wave generation

    Czech Academy of Sciences Publication Activity Database

    Prukner, Václav; Koláček, Karel; Schmidt, Jiří; Štraus, Jaroslav; Frolov, Oleksandr; Martínková, M.

    2006-01-01

    Roč. 56, suppl.B (2006), s. 342-348 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/22nd./. Praha, 26.6.2006-29.6.2006] R&D Projects: GA ČR GA202/06/1324; GA MŠk 1P04LA235 Institutional research plan: CEZ:AV0Z20430508 Keywords : Shock wave in water * Corona-like multi-streamer discharge Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.568, year: 2006

  16. Line Shape Modeling for the Diagnostic of the Electron Density in a Corona Discharge

    Directory of Open Access Journals (Sweden)

    Joël Rosato

    2017-09-01

    Full Text Available We present an analysis of spectra observed in a corona discharge designed for the study of dielectrics in electrical engineering. The medium is a gas of helium and the discharge was performed at the vicinity of a tip electrode under high voltage. The shape of helium lines is dominated by the Stark broadening due to the plasma microfield. Using a computer simulation method, we examine the sensitivity of the He 492 nm line shape to the electron density. Our results indicate the possibility of a density diagnostic based on passive spectroscopy. The influence of collisional broadening due to interactions between the emitters and neutrals is discussed.

  17. Modeling and characterization of field-enhanced corona discharge in ozone-generator diode

    Science.gov (United States)

    Patil, Jagadish G.; Vijayan, T.

    2010-02-01

    Electric field enhanced corona plasma discharge in ozone generator diode of axial symmetry has been investigated and characterized in theory. The cathode K of diode is made of a large number of sharpened nozzles arranged on various radial planes on the axial mast and pervaded in oxygen gas inside the anode cup A, produces high fields over MV/m and aids in the formation of a corona plume of dense ozone cloud over the cathode surface. An r-z finite difference scheme has been devised and employed to numerically determine the potential and electric field distributions inside the diode. The analyses of cathode emissions revealed a field emission domain conformed to modified Child-Langmuir diode-current. Passage of higher currents (over μA) in shorter A-K gaps d gave rise to cathode heated plasma extending from the corona to Saha regimes depending on local temperature. Plasma densities of order 102-106 m-3 are predicted in these. For larger d however, currents are smaller and heating negligible and a negative corona favoring ozone formation is attained. High ozone yields about 20 per cent of oxygen input is predicted in this domain. The generator so developed will be applied to various important applications such as, purification of ambient air /drinking water, ozone therapy, and so on.

  18. Modeling and characterization of field-enhanced corona discharge in ozone-generator diode

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Jagadish G; Vijayan, T, E-mail: jagdishlove@gmail.co [Mahatma Education Society' s ' Pillai' s Institute of Information Technology, Engineering, Media Studies and Research' Dr. K M Vasudevan Pillai' s Campus, Sector 16, New Panvel, Navi Mumbai - 410 206 (India)

    2010-02-01

    Electric field enhanced corona plasma discharge in ozone generator diode of axial symmetry has been investigated and characterized in theory. The cathode K of diode is made of a large number of sharpened nozzles arranged on various radial planes on the axial mast and pervaded in oxygen gas inside the anode cup A, produces high fields over MV/m and aids in the formation of a corona plume of dense ozone cloud over the cathode surface. An r-z finite difference scheme has been devised and employed to numerically determine the potential and electric field distributions inside the diode. The analyses of cathode emissions revealed a field emission domain conformed to modified Child-Langmuir diode-current. Passage of higher currents (over {mu}A) in shorter A-K gaps d gave rise to cathode heated plasma extending from the corona to Saha regimes depending on local temperature. Plasma densities of order 10{sup 2}-10{sup 6} m{sup -3} are predicted in these. For larger d however, currents are smaller and heating negligible and a negative corona favoring ozone formation is attained. High ozone yields about 20 per cent of oxygen input is predicted in this domain. The generator so developed will be applied to various important applications such as, purification of ambient air /drinking water, ozone therapy, and so on.

  19. Modeling and characterization of field-enhanced corona discharge in ozone-generator diode

    International Nuclear Information System (INIS)

    Patil, Jagadish G; Vijayan, T

    2010-01-01

    Electric field enhanced corona plasma discharge in ozone generator diode of axial symmetry has been investigated and characterized in theory. The cathode K of diode is made of a large number of sharpened nozzles arranged on various radial planes on the axial mast and pervaded in oxygen gas inside the anode cup A, produces high fields over MV/m and aids in the formation of a corona plume of dense ozone cloud over the cathode surface. An r-z finite difference scheme has been devised and employed to numerically determine the potential and electric field distributions inside the diode. The analyses of cathode emissions revealed a field emission domain conformed to modified Child-Langmuir diode-current. Passage of higher currents (over μA) in shorter A-K gaps d gave rise to cathode heated plasma extending from the corona to Saha regimes depending on local temperature. Plasma densities of order 10 2 -10 6 m -3 are predicted in these. For larger d however, currents are smaller and heating negligible and a negative corona favoring ozone formation is attained. High ozone yields about 20 per cent of oxygen input is predicted in this domain. The generator so developed will be applied to various important applications such as, purification of ambient air /drinking water, ozone therapy, and so on.

  20. Plasma sterilization of polyethylene terephthalate bottles by pulsed corona discharge at atmospheric pressure.

    Science.gov (United States)

    Masaoka, Satoshi

    2007-06-01

    A pulsed power supply was used to generate a corona discharge on a polyethylene terephthalate bottle, to conduct plasma sterilization at atmospheric pressure. Before generating such a discharge, minute quantities of water were attached to the inner surface of the bottle and to the surface of a high voltage (HV) electrode inserted into the bottle. Next, high-voltage pulses of electricity were discharged between electrodes for 6.0s, while rotating the bottle. The resulting spore log reduction values of Bacillus subtilis and Aspergillus niger on the inner surface of the bottle were 5.5 and 6 or higher, respectively, and those on the HV electrode surface were each 6 or higher for both strains. The presence of the by-products gaseous ozone, hydrogen peroxide, and nitric ions resulting from the electrical discharge was confirmed.

  1. Experimental study of negative corona discharge in pure carbon dioxide and its mixtures with oxygen

    International Nuclear Information System (INIS)

    Mikoviny, T; Kocan, M; Matejcik, S; Mason, N J; Skalny, J D

    2004-01-01

    The products of a negative corona discharge in both pure CO 2 and mixtures of CO 2 + O 2 have been studied using a coaxial cylindrical electrode geometry with particular emphasis on the production of ozone. The discharge current in pure CO 2 was found to be highly sensitive to the presence of trace concentrations of molecular oxygen and to changes in the flow speed through the discharge. The effect of dissociative electron attachment to ozone on the discharge current was studied by measurements of ozone and CO production. The ozone concentration increases monotonically with increasing content of oxygen in the mixture with carbon dioxide, whereas the CO concentration exhibits a flat maximum for oxygen concentrations of around 4%. A simple kinetic model of the dominant chemical processes is described and compared with the experimental results

  2. Development of a short pulsed corona discharge ionization source for ion mobility spectrometry

    International Nuclear Information System (INIS)

    An Yuan; Aliaga-Rossel, R.; Choi, Peter; Gilles, Jean-Paul

    2005-01-01

    The development of a pulsed corona discharge ionization source and its use in ion mobility spectrometry (IMS) is presented. In a point-plane electrode geometry, an electrical pulse up to 12 kV, 150 ns rise time and 500 ns pulse width was used to generate a corona discharge in air. A single positive high voltage pulse was able to generate about 1.6x10 10 ions at energy consumption of 22 μJ. Since the temporal distribution of ions is in a pulsed form, the possibility of removal the ion gate has been investigated. By purposely arranging the interface between discharge field and drift field, nearly 10 7 positive ions were drawn into the drift region with absence of the ion gate after every single discharge. The positive spectrum of acetone dimer (working at room temperature) was obtained with a resolving power of 20 by using this configuration. The advantages of this new scheme are the low power consumption compared with the dc method as well as the simplicity of the IMS cell structure

  3. Breakdown of methylene blue and methyl orange by pulsed corona discharge

    International Nuclear Information System (INIS)

    Grabowski, L R; Veldhuizen, E M van; Pemen, A J M; Rutgers, W R

    2007-01-01

    The recently developed corona above water technique is applied to water containing 10 mg l -1 methylene blue (MB) or methyl orange (MO). The corona discharge pulses are created with a spark gap switched capacitor followed by a transmission line transformer. The pulse amplitude is 40 kV; its duration is 50 ns. At a pulse repetition rate of 10 Hz this leads to an average power of 0.6 W into the discharge. MB and MO are completely decolourized in ∼20 min. This corresponds to a yield of ∼4.5 gr kW -1 h -1 , which is much higher than obtained with other discharge techniques or sonoluminescence. The high yield is reflected in the observed temperature increase of only ∼1 K. Tests with additional chemicals show that the initial speed of the conversion can be influenced but the total time required for total decolourization is constant. Further, it follows that the main oxidation path of the dyes is by direct ozone attack and the conversion products are strong acids

  4. Effect of pulsed corona discharge voltage and feed gas flow rate on dissolved ozone concentration

    Energy Technology Data Exchange (ETDEWEB)

    Prasetyaningrum, A., E-mail: ajiprasetyaningrum@gmail.com; Ratnawati,; Jos, B. [Department of Chemical Engineering, Faculty of Engineering, Diponegoro University Jl. Prof. H. Soedarto Tembalang, Semarang, Central Java, Indonesia, 50276 (Indonesia)

    2015-12-29

    Ozonization is one of the methods extensively used for water purification and degradation of organic materials. Ozone (O{sub 3}) is recognized as a powerful oxidizing agent. Due to its strong oxidability and better environmental friendless, ozone increasing being used in domestic and industrial applications. Current technology in ozone production utilizes several techniques (corona discharge, ultra violet radiation and electrolysis). This experiment aimed to evaluating effect of voltage and gas flow rate on ozone production with corona discharge. The system consists of two net-type stainless steel electrode placed in a dielectric barrier. Three pulsed voltage (20, 30, 40 KV) and flow rate (5, 10, 15 L/min) were prepare for operation variable at high frequency (3.7 kHz) with AC pulsed power supply. The dissolved ozone concentration depends on the applied high-voltage level, gas flow rate and the discharge exposure duration. The ozone concentration increases with decreasing gas flow rate. Dissolved ozone concentrations greater than 200 ppm can be obtained with a minimum voltage 40 kV.

  5. Breakdown of methylene blue and methyl orange by pulsed corona discharge

    Science.gov (United States)

    Grabowski, L. R.; van Veldhuizen, E. M.; Pemen, A. J. M.; Rutgers, W. R.

    2007-05-01

    The recently developed corona above water technique is applied to water containing 10 mg l-1 methylene blue (MB) or methyl orange (MO). The corona discharge pulses are created with a spark gap switched capacitor followed by a transmission line transformer. The pulse amplitude is 40 kV; its duration is 50 ns. At a pulse repetition rate of 10 Hz this leads to an average power of 0.6 W into the discharge. MB and MO are completely decolourized in ~20 min. This corresponds to a yield of ~4.5 gr kW-1h-1, which is much higher than obtained with other discharge techniques or sonoluminescence. The high yield is reflected in the observed temperature increase of only ~1 K. Tests with additional chemicals show that the initial speed of the conversion can be influenced but the total time required for total decolourization is constant. Further, it follows that the main oxidation path of the dyes is by direct ozone attack and the conversion products are strong acids.

  6. Breakdown of methylene blue and methyl orange by pulsed corona discharge

    Energy Technology Data Exchange (ETDEWEB)

    Grabowski, L R [Department of Applied Physics, Technische Universiteit Eindhoven (Netherlands); Veldhuizen, E M van [Department of Applied Physics, Technische Universiteit Eindhoven (Netherlands); Pemen, A J M [Department of Electrical Engineering, Technische Universiteit Eindhoven (Netherlands); Rutgers, W R [Department of Applied Physics, Technische Universiteit Eindhoven (Netherlands)

    2007-05-15

    The recently developed corona above water technique is applied to water containing 10 mg l{sup -1} methylene blue (MB) or methyl orange (MO). The corona discharge pulses are created with a spark gap switched capacitor followed by a transmission line transformer. The pulse amplitude is 40 kV; its duration is 50 ns. At a pulse repetition rate of 10 Hz this leads to an average power of 0.6 W into the discharge. MB and MO are completely decolourized in {approx}20 min. This corresponds to a yield of {approx}4.5 gr kW{sup -1}h{sup -1}, which is much higher than obtained with other discharge techniques or sonoluminescence. The high yield is reflected in the observed temperature increase of only {approx}1 K. Tests with additional chemicals show that the initial speed of the conversion can be influenced but the total time required for total decolourization is constant. Further, it follows that the main oxidation path of the dyes is by direct ozone attack and the conversion products are strong acids.

  7. Effect of pulsed corona discharge voltage and feed gas flow rate on dissolved ozone concentration

    International Nuclear Information System (INIS)

    Prasetyaningrum, A.; Ratnawati,; Jos, B.

    2015-01-01

    Ozonization is one of the methods extensively used for water purification and degradation of organic materials. Ozone (O 3 ) is recognized as a powerful oxidizing agent. Due to its strong oxidability and better environmental friendless, ozone increasing being used in domestic and industrial applications. Current technology in ozone production utilizes several techniques (corona discharge, ultra violet radiation and electrolysis). This experiment aimed to evaluating effect of voltage and gas flow rate on ozone production with corona discharge. The system consists of two net-type stainless steel electrode placed in a dielectric barrier. Three pulsed voltage (20, 30, 40 KV) and flow rate (5, 10, 15 L/min) were prepare for operation variable at high frequency (3.7 kHz) with AC pulsed power supply. The dissolved ozone concentration depends on the applied high-voltage level, gas flow rate and the discharge exposure duration. The ozone concentration increases with decreasing gas flow rate. Dissolved ozone concentrations greater than 200 ppm can be obtained with a minimum voltage 40 kV

  8. Effect of pulsed corona discharge voltage and feed gas flow rate on dissolved ozone concentration

    Science.gov (United States)

    Prasetyaningrum, A.; Ratnawati, Jos, B.

    2015-12-01

    Ozonization is one of the methods extensively used for water purification and degradation of organic materials. Ozone (O3) is recognized as a powerful oxidizing agent. Due to its strong oxidability and better environmental friendless, ozone increasing being used in domestic and industrial applications. Current technology in ozone production utilizes several techniques (corona discharge, ultra violet radiation and electrolysis). This experiment aimed to evaluating effect of voltage and gas flow rate on ozone production with corona discharge. The system consists of two net-type stainless steel electrode placed in a dielectric barrier. Three pulsed voltage (20, 30, 40 KV) and flow rate (5, 10, 15 L/min) were prepare for operation variable at high frequency (3.7 kHz) with AC pulsed power supply. The dissolved ozone concentration depends on the applied high-voltage level, gas flow rate and the discharge exposure duration. The ozone concentration increases with decreasing gas flow rate. Dissolved ozone concentrations greater than 200 ppm can be obtained with a minimum voltage 40 kV.

  9. Evaluation of the potential of soil remediation by direct multi-channel pulsed corona discharge in soil.

    Science.gov (United States)

    Wang, Tie Cheng; Qu, Guangzhou; Li, Jie; Liang, Dongli

    2014-01-15

    A novel approach, named multi-channel pulsed corona discharge in soil, was developed for remediating organic pollutants contaminated soil, with p-nitrophenol (PNP) as the model pollutant. The feasibility of PNP degradation in soil was explored by evaluating effects of pulse discharge voltage, air flow rate and soil moisture on PNP degradation. Based on roles of chemically active species and evolution of degradation intermediates, PNP degradation processes were discussed. Experimental results showed that about 89.4% of PNP was smoothly degraded within 60min of discharge treatment at pulse discharge voltage 27kV, soil moisture 5% and air flow rate 0.8Lmin(-1), and the degradation process fitted the first-order kinetic model. Increasing pulse discharge voltage was found to be favorable for PNP degradation, but not for energy yield. There existed appropriate air flow rate and soil moisture for obtaining gratifying PNP degradation efficacy. Roles of radical scavenger and measurement of active species suggested that ozone, H2O2, and OH radicals played very important roles in PNP degradation. CN bond in PNP molecule was cleaved, and the main intermediate products such as hydroquinone, benzoquinone, catechol, phenol, acetic acid, formic acid, oxalic acid, NO2(-) and NO3(-) were identified. Possible pathway of PNP degradation in soil in such a system was proposed. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Influence of the airflow speed along transmission lines on the DC corona discharge loss, using finite element approach

    Energy Technology Data Exchange (ETDEWEB)

    Shemshadi, A.; Akbari, A. [Electric Department, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Niayesh, K. [Electric Engineering Department, Tehran University, Tehran (Iran, Islamic Republic of)

    2012-07-15

    Corona discharge is of great interest from the physical point of view and due to its numerous practical applications in industry and especially one of the most important sources of loss in the high voltage transmission lines. This paper provides guidelines for the amount of electric loss caused by corona phenomenon occurred around a DC high voltage wire placed between two flat plates and influence of wind speed rate on the amount of corona loss using COMSOL Multiphysics. So electric potential distribution patterns and charge density diffusion around the wire are studied in this article.

  11. Electrolysis Processes in D.C. Corona Discharges in Humid Air

    Science.gov (United States)

    Lelièvre, J.; Dubreuil, N.; Brisset, J.-L.

    1995-04-01

    Aqueous solutions exposed to the flux of the neutrals emitted in a d.c. point-to-plane corona discharge in air enriched with NO-3 and NO-2 anions as the matching counter-ions of the protons. The nitrate concentration continuously increases with the treatment time while that of the nitrites presents a maximum. Both concentrations are increasing functions of the current intensity and the exposure time. These results are examined in terms of successive electrochemical reactions and involve oxidation and reduction reactions at each electrode. L'exposition d'une solution aqueuse aux neutres d'une décharge couronne pointe-plan continue établie dans l'air humide fait apparaître en solution des ions nitrites et nitrates qui équilibrent la formation des protons. La concentration en nitrates croît continûment tandis que celle des nitrites présente un maximum. Un mécanisme d'oxydations successives est proposé; il implique des réactions électrochimiques à chaque électrode et rend compte que la décharge négative engendre des concentrations en nitrite supérieures à la décharge positive. Un développement du modèle concourt à expliquer la différence d'effets observés pour des décharges positives ou négatives selon la nature du gaz plasmagène.

  12. Ignition method of corona discharge with modulation of the field in ion source of ion mobility spectrometer

    International Nuclear Information System (INIS)

    Gromov, Evgeniy

    2011-01-01

    The new method for the ignition of the corona discharge has been developed, which improves the stability of the ion mobility spectrometer and the resolution of the instrument. The system of forming a corona discharge without additional electrodes, which are used in a number of known structures for the pre-ionization, has been developed. This simplifies the design of the proposed source and an electronic control circuit. IMS technology is widely used in different civil and military fields for vapor-phase detection of explosive, narcotics, chemical warfare agents, biology molecules and so on. There are set of methods whose are used for the ionization of molecules under analysis. They are the following: radioactive ionization, ultraviolet photoionization, laser ionization, electric field ionization, corona spray ionization, electro spray ionization, roentgen ionization, and surface ionization. All these methods has their own advantages and disadvantages. A comparing of ion mobility spectra of non-polar hydrocarbons for photoionization, corona discharge ionization and 63 Ni ionization, had carried in. In our work we have investigated four types of IMS spectrometers whose use different sources for molecules under analysis ionization. They use radioactive ionization, ultraviolet photoionization, laser ionization, and roentgen ionization. The traditional explosives had investigated in experiments. In electricity, a corona discharge is an electrical discharge brought on by the ionization of a fluid surrounding a conductor, which occurs when the potential gradient (the strength of the electric field) exceeds a certain value, but conditions are insufficient to cause complete electrical breakdown or arcing.

  13. An optical sensors for monitoring SF6 dissociation in a corona discharge

    International Nuclear Information System (INIS)

    Irawan, R.; Scelsi, G.B.; Woolsey, G.A.

    1999-01-01

    Sulphur hexafluoride (SF 6 ) is a chemically inert gas (Schumb, 1947) and has high dielectric strength, 3 times greater than air (Morrison and Robins, 1994). In high voltage systems, it is used both as a dielectric and an arc-quenching medium. An electrical breakdown event such as a partial discharge (corona) or arc will dissociate SF 6 into sulphur fluorides, sulphur and fluorine. In a contaminant-free environment, the dissociation products recombine back to SF 6 after extinction of the electrical discharge. Otherwise, some of the products will react with contaminants such as water vapour and oxygen, and with the metal surfaces and electrodes of the discharge chamber, to produce by-products including gaseous sulphur oxyfluorides and solid by-products (Van Brunt, 1985; Griffin et al, 1990 and Vukovic, 1997). As a consequence, a reduction in SF 6 concentration takes place, and the insulating efficiency of the system is degraded. If the SF 6 is not renewed, failure of the high voltage system is likely to eventually occur. One method of monitoring a system is to look for the presence of partial discharges, using techniques such as ultrasonic wave detection (Auckland et al, 1996) or fluorescent plastic fibre (Kurosawa et al., 1997). More directly, the integrity of the SF 6 may be examined using techniques such as mass spectrometry, gas chromatography-mass spectrometry and Fourier Transform Infra-Red Spectroscopy. Such techniques, however, are bulky and require gas samples to be extracted, and so they are unsuited to field use. Since SF 6 insulating systems involve high voltages and a high level of electromagnetic interference, direct in-situ optical monitoring appears to provide the best approach. This paper describes the development of such an optical sensing technique, specifically for continuous monitoring of SF 6 degradation in partial or corona discharges

  14. A Study of Electromagnetic Radiation of Corona Discharge Near 500-Kv Electric Installations

    International Nuclear Information System (INIS)

    Korzhov, A. V.; Okrainskaya, I. S.; Sidorov, A. I.; Kufel'd, V. D.

    2004-01-01

    Data on the spectral composition and intensity of electromagnetic radiation of corona discharge are obtained in an experimental study performed on the outdoor switchgear of the Shagol 500-kV substation of the Chelyabinsk Enterprise of Trunk Transmission Grids and under a 500-kV Shagol - Kozyrevo overhead transmission line. The electromagnetic environment on the territory of the 500-kV outdoor switchgear is shown to be determined by narrow-band radiations (harmonics of the frequency of electric supply) and wide-band radiations due to corona discharges of high-voltage sources. This means that the personnel experience the action of a commercial-frequency electric field and electromagnetic radiation of a quite wide range, which is not allowed for by the existing guidelines. It is recommended to continue the study in cooperation with medical institutions in order to create guidelines that would allow for the joint action of commercial-frequency electric field and electromagnetic radiation and for the voltage in the line, the current load, the meteorological situation, and other factors

  15. Kinetic model of vibrational relaxation in a humid-air pulsed corona discharge

    International Nuclear Information System (INIS)

    Komuro, Atsushi; Ono, Ryo; Oda, Tetsuji

    2010-01-01

    The effect of humidity on the vibrational relaxation of O 2 (v) and N 2 (v) in a humid-air pulsed corona discharge is studied using a kinetic model. We previously showed that humidity markedly increases the vibration-to-translation (V-T) rate of molecules in a humid-air pulsed corona discharge by measuring O 2 (v) density (Ono et al 2010 Plasma Sources Sci. Technol. 19 015009). In this paper, we numerically calculate the vibrational kinetics of O 2 , N 2 and H 2 O to study the reason behind the acceleration of V-T in the presence of humidity. The calculation closely reproduces the measured acceleration of V-T due to humidity, and shows that the increase in the V-T rate is caused by the fast vibration-to-vibration (V-V) processes of O 2 -H 2 O and N 2 -H 2 O and the subsequent rapid V-T process of H 2 O-H 2 O. In addition, it is shown that O atom density is also important in the vibrational kinetics owing to the rapid V-T process of O 2 -O.

  16. Generation of ozone by pulsed corona discharge over water surface in hybrid gas-liquid electrical discharge reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lukes, Petr [Department of Pulse Plasma Systems, Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Za Slovankou 3, PO Box 17, 182 21 Prague 8 (Czech Republic); Clupek, Martin [Department of Pulse Plasma Systems, Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Za Slovankou 3, PO Box 17, 182 21 Prague 8 (Czech Republic); Babicky, Vaclav [Department of Pulse Plasma Systems, Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Za Slovankou 3, PO Box 17, 182 21 Prague 8 (Czech Republic); Janda, Vaclav [Department of Water Technology and Environmental Engineering, Institute of Chemical Technology, Technicka 5, 160 28 Prague 6 (Czech Republic); Sunka, Pavel [Department of Pulse Plasma Systems, Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Za Slovankou 3, PO Box 17, 182 21 Prague 8 (Czech Republic)

    2005-02-07

    Ozone formation by a pulse positive corona discharge generated in the gas phase between a planar high voltage electrode made from reticulated vitreous carbon and a water surface with an immersed ground stainless steel plate electrode was investigated under various operating conditions. The effects of gas flow rate (0.5-3 litre min{sup -1}), discharge gap spacing (2.5-10 mm), applied input power (2-45 W) and gas composition (oxygen containing argon or nitrogen) on ozone production were determined. Ozone concentration increased with increasing power input and with increasing discharge gap. The production of ozone was significantly affected by the presence of water vapour formed through vaporization of water at the gas-liquid interface by the action of the gas phase discharge. The highest energy efficiency for ozone production was obtained using high voltage pulses of approximately 150 ns duration in Ar/O{sub 2} mixtures with the maximum efficiency (energy yield) of 23 g kW h{sup -1} for 40% argon content.

  17. Generation of ozone by pulsed corona discharge over water surface in hybrid gas-liquid electrical discharge reactor

    International Nuclear Information System (INIS)

    Lukes, Petr; Clupek, Martin; Babicky, Vaclav; Janda, Vaclav; Sunka, Pavel

    2005-01-01

    Ozone formation by a pulse positive corona discharge generated in the gas phase between a planar high voltage electrode made from reticulated vitreous carbon and a water surface with an immersed ground stainless steel plate electrode was investigated under various operating conditions. The effects of gas flow rate (0.5-3 litre min -1 ), discharge gap spacing (2.5-10 mm), applied input power (2-45 W) and gas composition (oxygen containing argon or nitrogen) on ozone production were determined. Ozone concentration increased with increasing power input and with increasing discharge gap. The production of ozone was significantly affected by the presence of water vapour formed through vaporization of water at the gas-liquid interface by the action of the gas phase discharge. The highest energy efficiency for ozone production was obtained using high voltage pulses of approximately 150 ns duration in Ar/O 2 mixtures with the maximum efficiency (energy yield) of 23 g kW h -1 for 40% argon content

  18. Measurement of gas temperature and OH density in the afterglow of pulsed positive corona discharge

    International Nuclear Information System (INIS)

    Ono, Ryo; Oda, Tetsuji

    2008-01-01

    The gas temperature and OH density in the afterglow of pulsed positive corona discharge are measured using the laser-induced predissociation fluorescence (LIPF) of OH radicals. Discharge occurs in a 13 mm point-to-plane gap in an atmospheric-pressure H 2 O(2.8%)/O 2 (2.0%)/N 2 mixture. The temperature measurement shows that (i) the temperature increases after discharge and (ii) the temperature near the anode tip (within 1 mm from the anode tip) is much higher than that of the rest of the discharge volume. Near the anode tip, the temperature increases from 500 K (t = 0 μs) to 1100 K (t = 20 μs), where t is the postdischarge time, while it increases from 400 K (t = 0 μs) to 700 K (t = 100 μs) in the rest of the discharge volume away from the anode tip. This temperature difference between the two volumes (near and far from the anode tip) causes a difference in the decay rate of OH density: OH density near the anode tip decays approximately 10 times slower than that far from the tip. The spatial distribution of OH density shows good agreement with that of the secondary streamer luminous intensity. This shows that OH radicals are mainly produced in the secondary streamer, not in the primary one

  19. Ozone production by a dc corona discharge in air contaminated by n-heptane

    International Nuclear Information System (INIS)

    Pekarek, S

    2008-01-01

    Beneficial purposes of ozone such as elimination of odours, harmful bacteria and mildew can be used for transportation of food, fruits and vegetables with the aim to extend their storage life. To date the main technique used for this purpose in the transportation of these commodities, e.g. by trucks, was cooling. Here a combination of cooling together with the supply of ozone into containers with these commodities is considered. For these purposes we studied the effect of air contamination by n-heptane (part of automotive fuels) and humidity on ozone production by a dc hollow needle to mesh corona discharge. We found that, for both polarities of the needle electrode, addition of n-heptane to air (a) decreases ozone production; (b) causes discharge poisoning to occur at lower current than for air; (c) does not substantially influence the current for which the ozone production reaches the maximum. Finally the maximum ozone production for the discharge in air occurs for the same current as the maximum ozone production for the discharge contaminated by n-heptane. We also found that humidity decreases ozone production from air contaminated by n-heptane irrespective of the polarity of the coronating needle electrode. This dependence is stronger for the discharge with the needle biased positively

  20. Transitions between corona, glow, and spark regimes of nanosecond repetitively pulsed discharges in air at atmospheric pressure

    OpenAIRE

    Pai , David ,; Lacoste , Deanna ,; Laux , C.

    2010-01-01

    International audience; In atmospheric pressure air preheated from 300 to 1000 K, the nanosecond repetitively pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and interelectrode gap distance) of each discharge regime. In particular, the experimental conditions necessary for the glow regime of NRP discharges have been determine...

  1. A novel pulsed corona discharge reactor based on surface streamers for diesel exhaust remediation

    Energy Technology Data Exchange (ETDEWEB)

    Malik, M.A.; Schoenbach, K.H. [Old Dominion Univ., Norfolk, VA (United States). Frank Reidy Research Center for Bioelectrics

    2010-07-01

    Modelling of surface streamers along insulating surfaces to determine the dielectric strength of insulators in high voltage systems has shown that surface streamers consist of a positive streamer head followed by quasi-neutral plasma in the channel behind and surrounded by a layer of positive charges. This paper described a novel pulsed corona discharge reactor which utilized such surface streamers along insulating surfaces. The electrodes were comprised of a stainless steel wire anode of 150 mm in diameter stretched along the surface of a glass sheet and two parallel aluminum strips as cathodes. An eight-stage Marx bank, was used to produce the surface streamers in nitrogen-oxygen mixtures at atmospheric pressure. The paper described the experimental study with particular reference to the schematics of a surface streamer plasma reactor and the dimensions of discharge spaces of three reactors. The purpose of the study was to find the optimum conditions for energy yield and effective destruction of nitrogen oxides from diesel engine exhaust. It was concluded that surface streamers generate a more diffuse plasma. Energy costs for production of ozone or nitrogen dioxide that require reactions with bulk gas molecules were nearly the same in surface streamer discharges as in volume streamer discharges. 12 refs., 1 tab., 7 figs.

  2. Ionization Capabilities of Hydronium Ions and High Electric Fields Produced by Atmospheric Pressure Corona Discharge.

    Science.gov (United States)

    Sato, Natsuhiko; Sekimoto, Kanako; Takayama, Mitsuo

    2016-01-01

    Atmospheric pressure corona discharge (APCD) was applied to the ionization of volatile organic compounds. The mass spectra of analytes having aromatic, phenolic, anilinic, basic and aliphatic in nature were obtained by using vapor supply and liquid smear supply methods. The vapor supply method mainly gave protonated analytes [A+H] + caused by proton transfer from hydronium ion H 3 O + , except for benzene, toluene and n -hexane that have lower proton affinity. The use of the liquid smear supply method resulted in the formation of molecular ion A ·+ and/or dehydride analyte [A-H] + , according to the nature of analytes used. The formation of A ·+ without fragment ions could be explained by the electron tunneling via high electric fields 10 8  V/m at the tip of the corona needle. The dehydride analytes [A-H] + observed in the mass spectra of n -hexane, di- and tributylamines may be explained by the hydride abstraction from the alkyl chains by the hydronium ion. The hydronium ion can play the two-roles for analytes, i.e. , the proton donor to form [A+H] + and the hydride acceptor to form [A-H] + .

  3. Modeling of hazardous air pollutant removal in the pulsed corona discharge

    International Nuclear Information System (INIS)

    Derakhshesh, Marzie; Abedi, Jalal; Omidyeganeh, Mohammad

    2009-01-01

    This study investigated the effects of two parts of the performance equation of the pulsed corona reactor, which is one of the non-thermal plasma processing tools of atmospheric pressure for eliminating pollutant streams. First, the effect of axial dispersion in the diffusion term and then the effect of different orders of the reaction in the decomposition rate term were considered. The mathematical model was primarily developed to predict the effluent concentration of the pulsed corona reactor using mass balance, and considering axial dispersion, linear velocity and decomposition rate of pollutant. The steady state form of this equation was subsequently solved assuming different reaction orders. For the derivation of the performance equation of the reactor, it was assumed that the decomposition rate of the pollutant was directly proportional to discharge power and the concentration of the pollutant. The results were validated and compared with another predicted model using their experimental data. The model developed in this study was also validated with two other experimental data in the literature for N 2 O

  4. Oxidation of ammonium sulfite by a multi-needle-to-plate gas phase pulsed corona discharge reactor

    Science.gov (United States)

    Ren, Hua; Lu, Na; Shang, Kefeng; Li, Jie; Wu, Yan

    2013-03-01

    The oxidation of ammonium sulfite in the ammonia-based flue gas desulfurization (FGD) process was investigated in a multi-needle-to-plate gas phase pulsed corona discharge reactor in this paper. The effect of several parameters, including capacitance and peak pulse voltage of discharge system, electrode gap and bubbling gas flow rate on the oxidation rate of ammonium sulfite was reviewed. The oxidation rate of ammonium sulfite could reach 47.2% at the capacitance, the peak pulse voltage, electrode gap and bubbling gas flow rate equal to 2 nF, -24.6 k V, 35 mm and 4 L min-1 within treatment time of 40 min The experimental results indicate that the gas phase pulsed discharge system with a multi-needle-to-plate electrode can oxide the ammonium sulfite. The oxidation rate increased with the applied capacitance and peak pulse voltage and decreased with the electrode gap. As the bubbling gas flow rate increased, the oxidation rate increased first and then tended to reach a stationary value. These results would be important for the process optimization of the (NH4)2SO3 to (NH4)2SO4 oxidation.

  5. [Research on the emission spectrum of NO molecule's γ-band system by corona discharge].

    Science.gov (United States)

    Zhai, Xiao-dong; Ding, Yan-jun; Peng, Zhi-min; Luo, Rui

    2012-05-01

    The optical emission spectrum of the gamma-band system of NO molecule, A2 sigma+ --> X2 pi(r), has been analyzed and calculated based on the energy structure of NO molecule' doublet states. By employing the theory of diatomic molecular Spectra, some key parameters of equations for the radiative transition intensity were evaluated theoretically, including the potentials of the doublet states of NO molecule's upper and lower energy levels, the electronic transition moments calculated by using r-centroid approximation method, and the Einstein coefficient of different vibrational and rotational levels. The simulated spectrum of the gamma-band system was calculated as a function of different vibrational and rotational temperature. Compared to the theoretical spectroscopy, the measured results were achieved from corona discharge experiments of NO and N2. The vibrational and rotational temperatures were determined approximately by fitting the measured spectral intensities with the calculated ones.

  6. Ionized-cluster source based on high-pressure corona discharge

    International Nuclear Information System (INIS)

    Lokuliyanage, K.; Huber, D.; Zappa, F.; Scheier, P.

    2006-01-01

    Full text: It has been demonstrated that energetic beams of large clusters, with thousands of atoms, can be a powerful tool for surface modification. Normally ionized cluster beams are obtained by electron impact on neutral beams produced in a supersonic expansion. At the University of Innsbruck we are pursuing the realization of a high current cluster ion source based on the corona discharge.The idea in the present case is that the ionization should occur prior to the supersonic expansion, thus supersede the need of subsequent electron impact. In this contribution we present the project of our source in its initial stage. The intensity distribution of cluster sizes as a function of the source parameters, such as input pressure, temperature and gap voltage, are investigated with the aid of a custom-built time of flight mass spectrometer. (author)

  7. Ozone generation by negative direct current corona discharges in dry air fed coaxial wire-cylinder reactors

    International Nuclear Information System (INIS)

    Yehia, Ashraf; Mizuno, Akira

    2013-01-01

    An analytical study was made in this paper for calculating the ozone generation by negative dc corona discharges. The corona discharges were formed in a coaxial wire-cylinder reactor. The reactor was fed by dry air flowing with constant rates at atmospheric pressure and room temperature, and stressed by a negative dc voltage. The current-voltage characteristics of the negative dc corona discharges formed inside the reactor were measured in parallel with concentration of the generated ozone under different operating conditions. An empirical equation was derived from the experimental results for calculating the ozone concentration generated inside the reactor. The results, that have been recalculated by using the derived equation, have agreed with the experimental results over the whole range of the investigated parameters, except in the saturation range for the ozone concentration. Therefore, the derived equation represents a suitable criterion for expecting the ozone concentration generated by negative dc corona discharges in dry air fed coaxial wire-cylinder reactors under any operating conditions in range of the investigated parameters.

  8. CORONA DISCHARGE REACTOR FOR SELECTIVE OXIDATION OF ALCOHOLS AND HYDROCARBONS USING OZONATION AND PHOTOXIDATION OF OVER TIO2

    Science.gov (United States)

    We have developed a process that combines the use of surface corona for the production of ozone by passing air or oxygen through a high voltage electrical discharge and the emitted UV is being used to activate a photocatalyst. A thin film of nanostructured TiO2 with primary part...

  9. Characterization and comprehension of corona partial discharge in air under power frequency to very low frequency voltage

    Science.gov (United States)

    Yuanxiang, ZHOU; Zhongliu, ZHOU; Ling, ZHANG; Yunxiao, ZHANG; Yajun, MO; Jiantao, SUN

    2018-05-01

    For the partial discharge test of electrical equipment with large capacitance, the use of low-frequency voltage instead of power frequency voltage can effectively reduce the capacity requirements of test power supply. However, the validity of PD test under low frequency voltage needs to be evaluated. In order to investigate the influence of voltage frequency on corona discharge in the air, the discharge test of the tip-plate electrode under the frequency from 50 to 0.1 Hz is carried out based on the impulse current method. The results show that some of the main features of corona under low frequency do not change. The magnitude of discharge in a positive half cycle is obviously larger than that in a negative cycle. The magnitude of discharge and interval in positive cycle are random, while that in negative cycle are regular. With the decrease of frequency, the inception voltage increases. The variation trend of maximum and average magnitude and repetition rate of the discharge in positive and negative half cycle with the variation of voltage frequency and magnitude is demonstrated, with discussion and interpretation from the aspects of space charge transportation, effective discharge time and transition of discharge modes. There is an obvious difference in the phase resolved pattern of partial discharge and characteristic parameters of discharge patterns between power and low frequency. The experimental results can be the reference for mode identification of partial discharge under low frequency tests. The trend of the measured parameters with the variation of frequency provides more information about the insulation defect than traditional measurements under a single frequency (usually 50 Hz). Also it helps to understand the mechanism of corona discharge with an explanation of the characteristics under different frequencies.

  10. Emission spectra of a pulse needle-to-plane corona-like discharge in conductive aqueous solution

    Czech Academy of Sciences Publication Activity Database

    Šimek, Milan; Člupek, Martin; Babický, Václav; Lukeš, Petr; Šunka, Pavel

    2012-01-01

    Roč. 21, č. 5 (2012), 055031-055031 ISSN 0963-0252 R&D Projects: GA AV ČR IAAX00430802 Institutional research plan: CEZ:AV0Z20430508 Keywords : Water * pulsed electrical breakdown * point-plane geometry * streamer propagation * corona discharge * emission spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.515, year: 2012 http://iopscience.iop.org/0963-0252/21/5/055031/pdf/0963-0252_21_5_055031.pdf

  11. The catalytic role of tungsten electrode material in the plasmachemical activity of a pulsed corona discharge in water

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Člupek, Martin; Babický, Václav; Sisrová, I.; Janda, V.

    2011-01-01

    Roč. 20, č. 3 (2011), 034011-034011 ISSN 0963-0252 R&D Projects: GA AV ČR IAAX00430802; GA ČR(CZ) GD104/09/H080 Institutional research plan: CEZ:AV0Z20430508 Keywords : corona discharge * water * erosion * tungsten * hydrogen peroxide * dimethylsulfoxide Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.521, year: 2011 http://www.ipp.cas.cz/Ips/public/lukes_2011a.pdf

  12. Electrical and spectroscopic analysis of mono- and multi-tip pulsed corona discharges in air at atmospheric pressure

    Science.gov (United States)

    Mraihi, A.; Merbahi, N.; Yousfi, M.; Abahazem, A.; Eichwald, O.

    2011-12-01

    This work is devoted to the analysis of experimental results obtained in dry air at atmospheric pressure in a positive point-to-plane corona discharge under a pulsed applied voltage in the cases of anodic mono- and multi-tips. In the mono-tip case, the peak corona current is analysed as a function of several experimental parameters such as magnitude, frequency and duration of pulsed voltage and gap distance. The variation of the corona discharge current is correlated with the ozone production. Then in the multi-tip case, the electrical behaviour is analysed as a function of the distance between two contiguous tips and the tip number in order to highlight the region of creation active species for the lowest dissipated power. Intensified charge-coupled device pictures and electric field calculations as a function of inter-tip distance are performed to analyse the mutual effect between two contiguous tips. The optical emission spectra are measured in the UV-visible-NIR wavelength range between 200 nm and 800 nm, in order to identify the main excited species formed in an air corona discharge such as the usual first and second positive systems with first negative systems of molecular nitrogen. The identification of atomic species (O triplet and N) and the quenching of NOγ emission bands are also emphasized.

  13. Electrical and spectroscopic analysis of mono- and multi-tip pulsed corona discharges in air at atmospheric pressure

    International Nuclear Information System (INIS)

    Mraihi, A; Merbahi, N; Yousfi, M; Abahazem, A; Eichwald, O

    2011-01-01

    This work is devoted to the analysis of experimental results obtained in dry air at atmospheric pressure in a positive point-to-plane corona discharge under a pulsed applied voltage in the cases of anodic mono- and multi-tips. In the mono-tip case, the peak corona current is analysed as a function of several experimental parameters such as magnitude, frequency and duration of pulsed voltage and gap distance. The variation of the corona discharge current is correlated with the ozone production. Then in the multi-tip case, the electrical behaviour is analysed as a function of the distance between two contiguous tips and the tip number in order to highlight the region of creation active species for the lowest dissipated power. Intensified charge-coupled device pictures and electric field calculations as a function of inter-tip distance are performed to analyse the mutual effect between two contiguous tips. The optical emission spectra are measured in the UV–visible–NIR wavelength range between 200 nm and 800 nm, in order to identify the main excited species formed in an air corona discharge such as the usual first and second positive systems with first negative systems of molecular nitrogen. The identification of atomic species (O triplet and N) and the quenching of NOγ emission bands are also emphasized.

  14. 2D simulation of active species and ozone production in a multi-tip DC air corona discharge

    Science.gov (United States)

    Meziane, M.; Eichwald, O.; Sarrette, J. P.; Ducasse, O.; Yousfi, M.

    2011-11-01

    The present paper shows for the first time in the literature a complete 2D simulation of the ozone production in a DC positive multi-tip to plane corona discharge reactor crossed by a dry air flow at atmospheric pressure. The simulation is undertaken until 1 ms and involves tens of successive discharge and post-discharge phases. The air flow is stressed by several monofilament corona discharges generated by a maximum of four anodic tips distributed along the reactor. The nonstationary hydrodynamics model for reactive gas mixture is solved using the commercial FLUENT software. During each discharge phase, thermal and vibrational energies as well as densities of radical and metastable excited species are locally injected as source terms in the gas medium surrounding each tip. The chosen chemical model involves 10 neutral species reacting following 24 reactions. The obtained results allow us to follow the cartography of the temperature and the ozone production inside the corona reactor as a function of the number of high voltage anodic tips.

  15. Investigation of Peculiarities of a High-Voltage Pulsing Corona Discharge in Carbonic Gas and an Feature Using of Such Discharge for CO2 Dissociation

    International Nuclear Information System (INIS)

    Berezina, G.P.; Mirny, V.I.; Omelaenko, O.L.; Us, V.S.

    2006-01-01

    On laboratory stand of plasmochemical reactor the feature of CO 2 dissociation with the purpose of CO production in high-voltage pulsing corona discharge is investigated at a voltage up to 120 kV, a pulse length of a current 0,5 μs a repetition rate up to 100 Hz. Peculiarities of volt-ampere characteristics of such discharge are studied at different pressures of air and carbonic gas in the discharge chamber and construction of an interior electrode. It is established that in conditions of the carried out experiments a maximum efficiency of CO accretion does not exceed 3,5%

  16. Characteristics of a Pulse-Periodic Corona Discharge in Atmospheric Air

    Science.gov (United States)

    Tarasenko, V. F.; Baksht, E. Kh.; Sosnin, E. A.; Burachenko, A. G.; Panarin, V. A.; Skakun, V. S.

    2018-05-01

    Pulse-periodic corona discharge in atmospheric air excited by applying a voltage pulse with a subnanosecond or microsecond rise time to a point electrode is studied experimentally. It is shown that, at a voltage rise rate of dU/ dt 1014 V/s, positive and negative ball-shaped streamers with a front velocity of ≥2 mm/ns form near the point electrode. As dU/ dt is reduced to 1010-1011 V/s, the streamer shape changes and becomes close to cylindrical. The propagation velocity of cylindrical streamers is found to be 0.1 mm/ns at dU/ dt 2 × 1010 V/s. It is shown that the propagation direction of a cylindrical streamer can be changed by tilting the point electrode, on the axis of which the electric field strength reaches its maximum value. It is established that, for the negative polarity of the point electrode and a microsecond rise time of the voltage pulse, a higher voltage is required to form a cylindrical streamer than for the positive polarity of the point electrode.

  17. Biodiesel production using fatty acids from food industry waste using corona discharge plasma technology.

    Science.gov (United States)

    Cubas, A L V; Machado, M M; Pinto, C R S C; Moecke, E H S; Dutra, A R A

    2016-01-01

    This article aims to describe an alternative and innovative methodology to transform waste, frying oil in a potential energy source, the biodiesel. The biodiesel was produced from fatty acids, using a waste product of the food industry as the raw material. The methodology to be described is the corona discharge plasma technology, which offers advantages such as acceleration of the esterification reaction, easy separation of the biodiesel and the elimination of waste generation. The best conditions were found to be an oil/methanol molar ratio of 6:1, ambient temperature (25 °C) and reaction time of 110 min and 30 mL of sample. The acid value indicates the content of free fatty acids in the biodiesel and the value obtained in this study was 0.43 mg KOH/g. Peaks corresponding to octadecadienoic acid methyl ester, octadecanoic acid methyl ester and octadecenoic acid methyl ester, from the biodiesel composition, were identified using GC-MS. A major advantage of this process is that the methyl ester can be obtained in the absence of chemical catalysts and without the formation of the co-product (glycerin). Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Evaluation of the potential of pentachlorophenol degradation in soil by pulsed corona discharge plasma from soil characteristics.

    Science.gov (United States)

    Wang, Tie Cheng; Lu, Na; Li, Jie; Wu, Yan

    2010-04-15

    Chlorinated organics are frequently found as harmful soil contaminants and persisted for extended periods of time. A novel approach, named pulsed corona discharge plasma (PCDP), was employed for the degradation of pentachlorophenol (PCP) in soil. Experimental results showed that 87% of PCP could be smoothly removed in 60 min. Increasing pulse voltage, enhancing soil pH, lowering humic acid (HA) in soil and reducing granular size of the soil were found to be favorable for PCP degradation efficiency. Oxidation and physical processes simultaneously contributed to PCP removal in soil and ozone was the main factor in PCDP treatment. C-Cl bonds in PCP were cleaved during PCDP treatment by Fourier transform infrared spectroscopy (FTIR) analysis. The mineralization of PCP was confirmed by total organic carbon (TOC) and dechlorination analyses. The main intermediate products such as tetrachlorocatechol, tetrachlorohydroquinone, acetic acid, formic acid, and oxalic acid were identified by HPLC/MS and ion chromatography. A possible pathway of PCP degradation in soil in such a system was proposed.

  19. Numerical simulation of an oxygen-fed wire-to-cylinder negative corona discharge in the glow regime

    Energy Technology Data Exchange (ETDEWEB)

    Yanallah, K; Pontiga, F [Dpt. Fisica Aplicada II, Universidad de Sevilla (Spain); Castellanos, A [Dpt. Electronica y Electromagnetismo, Universidad de Sevilla (Spain)

    2011-02-09

    Negative glow corona discharge in flowing oxygen has been numerically simulated for a wire-to-cylinder electrode geometry. The corona discharge is modelled using a fluid approximation. The radial and axial distributions of charged and neutral species are obtained by solving the corresponding continuity equations, which include the relevant plasma-chemical kinetics. Continuity equations are coupled with Poisson's equation and the energy conservation equation, since the reaction rate constants may depend on the electric field and temperature. The experimental values of the current-voltage characteristic are used as input data into the numerical calculations. The role played by different reactions and chemical species is analysed, and the effect of electrical and geometrical parameters on ozone generation is investigated. The reliability of the numerical model is verified by the reasonable agreement between the numerical predictions of ozone concentration and the experimental measurements.

  20. Numerical simulation of an oxygen-fed wire-to-cylinder negative corona discharge in the glow regime

    Science.gov (United States)

    Yanallah, K.; Pontiga, F.; Castellanos, A.

    2011-02-01

    Negative glow corona discharge in flowing oxygen has been numerically simulated for a wire-to-cylinder electrode geometry. The corona discharge is modelled using a fluid approximation. The radial and axial distributions of charged and neutral species are obtained by solving the corresponding continuity equations, which include the relevant plasma-chemical kinetics. Continuity equations are coupled with Poisson's equation and the energy conservation equation, since the reaction rate constants may depend on the electric field and temperature. The experimental values of the current-voltage characteristic are used as input data into the numerical calculations. The role played by different reactions and chemical species is analysed, and the effect of electrical and geometrical parameters on ozone generation is investigated. The reliability of the numerical model is verified by the reasonable agreement between the numerical predictions of ozone concentration and the experimental measurements.

  1. Numerical simulation of an oxygen-fed wire-to-cylinder negative corona discharge in the glow regime

    International Nuclear Information System (INIS)

    Yanallah, K; Pontiga, F; Castellanos, A

    2011-01-01

    Negative glow corona discharge in flowing oxygen has been numerically simulated for a wire-to-cylinder electrode geometry. The corona discharge is modelled using a fluid approximation. The radial and axial distributions of charged and neutral species are obtained by solving the corresponding continuity equations, which include the relevant plasma-chemical kinetics. Continuity equations are coupled with Poisson's equation and the energy conservation equation, since the reaction rate constants may depend on the electric field and temperature. The experimental values of the current-voltage characteristic are used as input data into the numerical calculations. The role played by different reactions and chemical species is analysed, and the effect of electrical and geometrical parameters on ozone generation is investigated. The reliability of the numerical model is verified by the reasonable agreement between the numerical predictions of ozone concentration and the experimental measurements.

  2. A Simple Analytical Model for Predicting the Detectable Ion Current in Ion Mobility Spectrometry Using Corona Discharge Ionization Sources

    Science.gov (United States)

    Kirk, Ansgar Thomas; Kobelt, Tim; Spehlbrink, Hauke; Zimmermann, Stefan

    2018-05-01

    Corona discharge ionization sources are often used in ion mobility spectrometers (IMS) when a non-radioactive ion source with high ion currents is required. Typically, the corona discharge is followed by a reaction region where analyte ions are formed from the reactant ions. In this work, we present a simple yet sufficiently accurate model for predicting the ion current available at the end of this reaction region when operating at reduced pressure as in High Kinetic Energy Ion Mobility Spectrometers (HiKE-IMS) or most IMS-MS instruments. It yields excellent qualitative agreement with measurement results and is even able to calculate the ion current within an error of 15%. Additional interesting findings of this model are the ion current at the end of the reaction region being independent from the ion current generated by the corona discharge and the ion current in High Kinetic Energy Ion Mobility Spectrometers (HiKE-IMS) growing quadratically when scaling down the length of the reaction region. [Figure not available: see fulltext.

  3. Hazardous gas treatment by atmospheric discharges

    International Nuclear Information System (INIS)

    Mizeraczyk, J.

    2005-01-01

    The emissions of NO x ; SO x , CO 2 and volatile organic compounds (VOCs) including fluorocarbons to the atmosphere influence heavily our environment, NO x and SO x emitted to the atmosphere are the major cause of acid rains, while CO 2 and VOCs emissions cause the greenhouse effect which leads to abnormal global heating of the atmosphere and creating in a temperature inversion layer that traps gaseous pollutants. Therefore, there is an increasing interest in controlling these emissions. A new technique, which uses the plasma processes induced by energetic electrons, emerges as one of the most effective methods of reducing concentrations of the emitted gaseous pollutants. Various plasma techniques have been tested for gaseous pollution control. The electron bean irradiation was found to be physically and economically efficient for NO x and SO x reduction in the exhaust gases from electrical and heat power plants. The capability of the non-thermal plasmas, produced in atmospheric pressure electrical discharges, for decomposition of the gaseous pollutants has been widely tested. These atmospheric pressure electrical discharges are dielectric barrier discharges, pulsed and de corona discharges (in the reactors with the point-to-plate, wire-cylinder and wire-plate geometries, in the reactors with flow stabilized corona torch and corona radical shower), gliding discharges, inductively coupled high-frequency discharges, ac surface discharges, ac discharges in the packed bed reactors, and microwave torch discharges. In this paper, after reviewing the methods and devices used for producing the non-thermal plasmas for gaseous pollutant control, some results of the laboratory experiments on the plasmas abatement of NO x ; SO x and various VOCs will be presented, followed by a discussion on the energy efficiency and by-products. Also some results obtained in the pilot-plants will be given. finally other possible applications of the presented plasma devices for controlling

  4. Corona discharge experiments in admixtures of N{sub 2} and CH{sub 4}: a laboratory simulation of Titan's atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, G; Skalny, J D; Klas, M; Zahoran, M [Department of Experimental Physics, Comenius University, Mlynska dolina F-2, 842 48 Bratislava (Slovakia); Mason, N J [Department of Physics and Astronomy, The Open University, Walton Hall, MK7 6AA, Milton Keynes (United Kingdom); Vladoiu, R; Manole, M [Ovidius University Constanta, B - dul Mamaia 124, 900527 Constanta (Romania)], E-mail: horeszka@gmail.com

    2009-08-15

    A positive corona discharge fed by a N{sub 2} : CH{sub 4} mixture (98 : 2) at atmospheric pressure and ambient temperature has been studied as a laboratory mimic of the chemical processes occurring in the atmosphere of Titan, Saturn's largest moon. In situ measurements of UV and IR transmission spectra within the discharge have shown that the main chemical product is C{sub 2}H{sub 2}, produced by dissociation of CH{sub 4}, with small but significant traces of ethane and HCN, all species that have been detected in Titan's atmosphere. A small amount (0.2%) of CH{sub 4} was decomposed after 12 min of treatment requiring an average energy of 2.7 kWh g{sup -1}. After 14 min the discharge was terminated due to the formation of a solid yellow deposit on the central wire electrode. Such a deposit is similar to that observed in other discharges and is believed to be an analogue of the aerosol and dust observed in Titan's atmosphere and is composed of chemical species commonly known as 'tholins'. We have also explored the electrical properties of the discharge. The admixture of methane into nitrogen caused an increase in the onset voltage of the discharge and consequently led to a reduction in the measured discharge current.

  5. Corona discharge experiments in admixtures of N2 and CH4: a laboratory simulation of Titan's atmosphere

    OpenAIRE

    Horvath, G.; Skalny, J. D.; Mason, N. J.; Klas, M.; Zahoran, M.; Vladoiu, R.; Manole, M.

    2009-01-01

    A positive corona discharge fed by a N2:CH4 mixture (98:2) at atmospheric pressure and ambient temperature has been studied as a laboratory mimic of the chemical processes occurring in the atmosphere of Titan, Saturn's largest moon. In-situ measurements of UV and IR transmission spectra within the discharge have shown that the main chemical product is C2H2, produced by dissociation of CH4, with small but significant traces of ethane and HCN, all species that have been detected in Titan's atmo...

  6. Transitions between corona, glow, and spark regimes of nanosecond repetitively pulsed discharges in air at atmospheric pressure

    Science.gov (United States)

    Pai, David Z.; Lacoste, Deanna A.; Laux, Christophe O.

    2010-05-01

    In atmospheric pressure air preheated from 300 to 1000 K, the nanosecond repetitively pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and interelectrode gap distance) of each discharge regime. In particular, the experimental conditions necessary for the glow regime of NRP discharges have been determined, with the notable result that there exists a minimum and maximum gap distance for its existence at a given ambient gas temperature. The minimum gap distance increases with decreasing gas temperature, whereas the maximum does not vary appreciably. To explain the experimental results, an analytical model is developed to explain the corona-to-glow (C-G) and glow-to-spark (G-S) transitions. The C-G transition is analyzed in terms of the avalanche-to-streamer transition and the breakdown field during the conduction phase following the establishment of a conducting channel across the discharge gap. The G-S transition is determined by the thermal ionization instability, and we show analytically that this transition occurs at a certain reduced electric field for the NRP discharges studied here. This model shows that the electrode geometry plays an important role in the existence of the NRP glow regime at a given gas temperature. We derive a criterion for the existence of the NRP glow regime as a function of the ambient gas temperature, pulse repetition frequency, electrode radius of curvature, and interelectrode gap distance.

  7. Chlorinated organic compound removal by gas phase pulsed streamer corona electrical discharge with reticulated vitreous carbon electrodes

    International Nuclear Information System (INIS)

    Kirkpatrick, M.J.; Finney, W.C.; Locke, B. R.

    2002-01-01

    Trichloroethylene (TCE) and vinyl chloride removal by pulsed corona discharge was investigated with attention to energy efficiency and byproduct identification. Approximately, 50 to 95 percent removal of TCE and vinyl chloride was observed depending on the energy density applied to the gas. Water vapor had no significant effect on TCE removal. Evidence was found for post-corona reactions leading to removal of vinyl chloride downstream of the plasma discharge. Energy efficiencies of 100-900 g/kw-hr in the case of 1000 ppm feed of TCE and efficiencies of 2-24 g/kw-hr for a 100 ppm feed of vinyl chloride were found. In TCE experiments, the formation of dichloroacetyl chloride was observed, while chloro-ethane formation was found for vinyl chloride. In both cases, Cl- was measured downstream of the pulsed corona reactor in a water trap using an ion-selective electrode, although measured amounts varied widely due to condensation in the gas lines between the reactor and the water trap. The addition of a platinum-rhodium coated electrode was found only to reduce the downstream removal of vinyl chloride at low energy density. (author)

  8. Study of Corona Discharge on 160 KeV, 10 mA Electron Accelerator Facility Using FEM

    International Nuclear Information System (INIS)

    Ghazali, Abu Bakar Mhd; Sobri, Rokiah Mohd

    2008-01-01

    This paper describes a method to verify the overall design of our electron accelerator. It is free from corona or spark discharge phenomenon. This locally designed electron accelerator facility is located at Nuclear Malaysia Complex, Bangi, Selangor. In this study, we describe the geometry of the pressure vessel filled with SF 6 gas at 2 atm to enclose the high voltage area of the accelerating tube. The Poisson's equation is used to calculate the contours of the electric field that is created between the cathode of -160 kV maximum and the wall of the vessel. The nearest sharp edge between the cathode and the pressure wall is 163 mm apart. The calculation is based on finite element method (FEM) for electrostatic charges in order to obtain an electric field contour in two-dimensional plane. We found that the surface charge density of the cathode is 1.1x10 -5 C/m 2 for the corona glowing seen at -90 kV. Moreover, the highest electric field near to (about 5 mm from) the sharp edge is about 2.7 MV/m, which is less than the dielectric strength of SF 6 gas, i.e. 6 MV/m and therefore, it proved that our design of the pressure vessel is save from corona or spark discharges

  9. Study of Corona Discharge on 160 KeV, 10 mA Electron Accelerator Facility Using FEM

    Science.gov (United States)

    Ghazali, Abu Bakar Mhd; Sobri, Rokiah Mohd

    2008-05-01

    This paper describes a method to verify the overall design of our electron accelerator. It is free from corona or spark discharge phenomenon. This locally designed electron accelerator facility is located at Nuclear Malaysia Complex, Bangi, Selangor. In this study, we describe the geometry of the pressure vessel filled with SF6 gas at 2 atm to enclose the high voltage area of the accelerating tube. The Poisson's equation is used to calculate the contours of the electric field that is created between the cathode of -160 kV maximum and the wall of the vessel. The nearest sharp edge between the cathode and the pressure wall is 163 mm apart. The calculation is based on finite element method (FEM) for electrostatic charges in order to obtain an electric field contour in two-dimensional plane. We found that the surface charge density of the cathode is 1.1×10-5 C/m2 for the corona glowing seen at -90 kV. Moreover, the highest electric field near to (about 5 mm from) the sharp edge is about 2.7 MV/m, which is less than the dielectric strength of SF6 gas, i.e. 6 MV/m and therefore, it proved that our design of the pressure vessel is save from corona or spark discharges.

  10. The Growth Potential of Corona Discharges from Aircraft Flying in Precipitation.

    Science.gov (United States)

    1987-11-12

    required for corona onset. However, it turns out that the fields required to generate corona from ’ce and water particles of the anticipated size are...still significantly larger than those commonly encountered in a thundercloud. The exception here is the long water filament drawn out when water drop...trial and error had 300 cone-angle, with a tip of radius -20Im (measured with a travelling microscope). It was necessary to electrolyse the tip in

  11. Observation of enhanced ozone in an electrically active storm over Socorro, NM: Implications for ozone production from corona discharges

    Science.gov (United States)

    Minschwaner, K.; Kalnajs, L. E.; Dubey, M. K.; Avallone, L. M.; Sawaengphokai, P. C.; Edens, H. E.; Winn, W. P.

    2008-09-01

    Enhancements in ozone were observed between about 3 and 10 km altitude within an electrically active storm in central New Mexico. Measurements from satellite sensors and ground-based radar show cloud top pressures between 300 and 150 mb in the vicinity of an ozonesonde launched from Socorro, NM, and heavy precipitation with radar reflectivities exceeding 50 dBZ. Data from a lightning mapping array and a surface electric field mill show a large amount of electrical activity within this thunderstorm. The observed ozone enhancements are large (50% above the mean) and could have resulted from a number of possible processes, including the advection of polluted air from the urban environments of El Paso and Juarez, photochemical production by lightning-generated NOx from aged thunderstorm outflow, downward mixing of stratospheric air, or local production from within the thunderstorm. We find that a large fraction of the ozone enhancement is consistent with local production from corona discharges, either from cloud particles or by corona associated with lightning. The implied global source of ozone from thunderstorm corona discharge is estimated to be 110 Tg O3 a-1 with a range between 40 and 180 Tg O3 a-1. This value is about 21% as large as the estimated ozone production rate from lightning NOx, and about 3% as large as the total chemical production rate of tropospheric ozone. Thus while the estimated corona-induced production of ozone may be significant on local scales, it is unlikely to be as important to the global ozone budget as other sources.

  12. Modeling of plasma chemical processes in the artificial ionized layer in the upper atmosphere by the nanosecond corona discharge

    Science.gov (United States)

    Vikharev, A. L.; Gorbachev, A. M.; Ivanov, O. A.; Kolisko, A. L.; Litvak, A. G.

    1993-08-01

    The plasma chemical processes in the corona discharge formed in air by a series of high voltage pulses of nanosecond duration are investigated experimentally. The experimental conditions (reduced electric field, duration and repetition frequency of the pulses, gas pressure in the chamber) modeled the regime of creation of the artificial ionized layer (AIL) in the upper atmosphere by a nanosecond microwave discharge. It was found that in a nanosecond microwave discharge predominantly generation of ozone occurs, and that the production of nitrogen dioxide is not large. The energy expenditures for the generation of one O 3 molecule were about 15 eV. On the basis of the experimental results the prognosis of the efficiency of ozone generation in AIL was made.

  13. DEGRADATION BY PULSED CORONA DISCHARGES: STUDY ON THE POSSIBLE CHEMICAL DEGRADATION PATHWAY FOR DICLOFENAC

    OpenAIRE

    TORRES-GODOY, CYNTHIA

    2012-01-01

    The remo val of hazardous organic pollutants such as polychlorinated biphenyls (PCB's), polycyclic aromatic hydrocarbons (benzopyrene, dibenzoanthracene), pesticides (DDT, lindane), and pharmaceutical products ( diclofenac, ibuprofen, carbamazepine) from waste water is a growing concem in environmental science and technology. Therefore, innovative methods for water remediation in removing contaminants from waste sites need to be examined. This work explores the use of Pulsed Corona Disc...

  14. Tar removal from biomass derived fuel gas by pulsed corona discharges: chemical kinetic study II

    NARCIS (Netherlands)

    Nair, S.A.; Yan, K.; Pemen, A.J.M.; Heesch, van E.J.M.; Ptasinski, K.J.; Drinkenburg, A.A.H.

    2005-01-01

    Tar (heavy hydrocarbon or poly aromatic hydrocarbon (PAH)) removal from biomass derived fuel gas is one of the biggest obstacles in its utilization for power generation. We have investigated pulsed corona as a method for tar removal. Our previous experimental results indicate the energy consumption

  15. Application of Ni-63 photo and corona discharge ionization for the analysis of chemical warfare agents and toxic wastes

    Science.gov (United States)

    Stach, J.; Adler, J.; Brodacki, M.; Doring, H.-R.

    1995-01-01

    Over the past decade, advances in instrumental design and refinements in the understanding of ion molecule reactions at atmospheric pressure enabled the application of Ion Mobility Spectrometry (IMS) as a simple inexpensive and sensitive analytical method for the detection of organic trace compounds. Positive and negative gas-phase ions for ion mobility spectrometry have been produced by a variety of methods, including photo-ionization, laser multi photon ionization, surface ionization, corona discharge ionization. The most common ion source used in ion mobility spectrometry is a radioactive Ni-63 foil which is favored due to simplicity, stability, convenience, and high selectivity. If reactant ions like (H2O(n)H)(+) or (H2O(n)O2)(-) dominate in the reaction region, nearly all kinds of compounds with a given proton or electron affinity; are ionized. However, the radioactivity of the Ni-63 foil is one disadvantage of this ion source that stimulates the development and application of other ionization techniques. In this paper, we report analyses of old chemical warfare agents and toxic wastes using Bruker RAID ion mobility spectrometers. Due to the modular construction of the measuring cell, the spectrometers can be equipped with different ion sources. The combined use of Ni-63, photo- and corona discharge ionization allows the identification of different classes of chemical compounds and yields in most cases comparable results.

  16. Inactivation of Candida albicans by Corona Discharge: The Increase of Inhibition Zones Area After Far Subsequent Exposition

    Directory of Open Access Journals (Sweden)

    Vladyslava Fantova

    2013-01-01

    Full Text Available The cold atmospheric pressure plasma generated by the negative corona discharge has inhibition effect on the microorganism growth. This effect is well-known and it can be demonstrated on the surface of cultivation agar plates by the formation of inhibition zones. We exposed the cultures of Candida albicans to the negative corona discharge plasma in a special arrangement in this study: The equal doses of plasma were applied subsequently twice or four times on the same culture on one Petri dish, while the distance between exposed points was variable. Only small differences were observed in decontaminated zone areas for twice exposed agar at the shortest distance between exposed points (1.5 cm. In case of the four times exposed agars, we observed significant differences in inhibition zone areas, dependent not only on the exposition site distances, but also on the exposition order. The largest inhibition zone size was observed for the first exposition decreasing to the fourth one. To check relevancy of these dependencies, we presume to conduct further set of experiments with lower yeast concentration. In conclusion, significant difference in partial inhibition zone sizes appeared only when four expositions on one Petri dish were carried out, whereas no significant difference was observed for two subsequent expositions. The explanation of this effect may be the subject of subsequent remote exposition(s, when minute amounts of scattered active particles act on the previously exposed areas; the influence of diffused ozone may also take place.

  17. Synthesis of AlN fine particles by surface corona discharge-CVD; Enmen corona hoden CVD ni yoru AlN biryushi no gosei

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Y.; Chiba, S. [Hokkaido National Industrial Research Institute, Sapporo (Japan); Harima, K> ; Kondo, K.; Shinohara, K. [Hokkaido University, Sapporo (Japan)

    1994-09-15

    With an objective to improve insulating and heat dissipating substrates substituting for the conventional alumina substrates, discussions been given on synthesis of AlN fine particles by means of gaseous phase reaction between AlCl3 and NH3 using surface corona discharge as a reaction exciting source. AIN particles should be highly pure to acquire high-heat conductivity, and fine and uniform particles to obtain dense sinters at low temperatures. The particles obtained by using the present method were amorphous particles having nearly spherical form and smooth surface. The particle diameter depends on the initial concentration of AlCl3, and is proportional to 0.4 square of the concentration. Within the range in the present experiment, the diameters ranged from 208 nm to 431 nm. The particle diameter increased in proportion to 0.2 square of an average gas stagnating time within the plasma generating region. The particle size distribution consisted of highly uniform fine particles having the standard deviation at about the same degree as that in the conventional thermal CVD process. The alumina-based oxygen was removed completely by reduction due to graphite powder, but the re-oxidation during removal of the remaining graphite using combustion had oxygen remained at 7.4% by weight. 16 refs., 7 figs.

  18. Morphological Processing of Ultraviolet Emissions of Electrical Corona Discharge for Analysis and Diagnostic Use

    Science.gov (United States)

    Schubert, Matthew R.; Moore, Andrew J.

    2015-01-01

    Electron cascades from electrical discharge produce secondary emissions from atmospheric plasma in the ultraviolet band. For a single point of discharge, these emissions exhibit a stereotypical discharge morphology, with latent information about the discharge location. Morphological processing can uncover the location and therefore can have diagnostic utility.

  19. Experimental and modeling study of the oxidation of acetaldehyde in an atmospheric-pressure pulsed corona discharge

    International Nuclear Information System (INIS)

    Klett, C; Touchard, S; Vega-Gonzalez, A; Redolfi, M; Bonnin, X; Hassouni, K; Duten, X

    2012-01-01

    This paper reports the results obtained for the degradation of acetaldehyde by an atmospheric plasma corona discharge working in a pulsed regime. It was shown that a few hundred ppm of acetaldehyde diluted in a pure N 2 gas flow can be removed up to 80% by a discharge fed with an electric power lower than 1 W. Under the same conditions, adding up to 5% of O 2 allowed the removal of up to 95% of the initial acetaldehyde. The main identified end products were CO 2 , CO and methanol. A quasi-homogeneous zero-dimensional chemical model was developed to investigate the respective efficiency of the discharge and post-discharge periods in the global removal of the pollutant. The identified main pathways of acetaldehyde degradation were quenching of N 2 metastable states during plasma pulses and oxidation by O and OH radicals during the post-discharge. This latter contribution increased with input power because of ozone accumulation in the gas mixture acting as an additional oxygen reservoir. (paper)

  20. Experimental and modeling study of the oxidation of acetaldehyde in an atmospheric-pressure pulsed corona discharge

    Science.gov (United States)

    Klett, C.; Touchard, S.; Vega-Gonzalez, A.; Redolfi, M.; Bonnin, X.; Hassouni, K.; Duten, X.

    2012-08-01

    This paper reports the results obtained for the degradation of acetaldehyde by an atmospheric plasma corona discharge working in a pulsed regime. It was shown that a few hundred ppm of acetaldehyde diluted in a pure N2 gas flow can be removed up to 80% by a discharge fed with an electric power lower than 1 W. Under the same conditions, adding up to 5% of O2 allowed the removal of up to 95% of the initial acetaldehyde. The main identified end products were CO2, CO and methanol. A quasi-homogeneous zero-dimensional chemical model was developed to investigate the respective efficiency of the discharge and post-discharge periods in the global removal of the pollutant. The identified main pathways of acetaldehyde degradation were quenching of N2 metastable states during plasma pulses and oxidation by O and OH radicals during the post-discharge. This latter contribution increased with input power because of ozone accumulation in the gas mixture acting as an additional oxygen reservoir.

  1. Spatial distribution of ozone density in pulsed corona discharges observed by two-dimensional laser absorption method

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Ryo; Oda, Tetsuji [Department of Electrical Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 (Japan)

    2004-03-07

    The spatial distribution of ozone density is measured in pulsed corona discharges with a 40 {mu}m spatial resolution using a two-dimensional laser absorption method. Discharge occurs in a 13 mm point-to-plane gap in dry air with a pulse duration of 100 ns. The result shows that the ozone density increases for about 100 {mu}s after the discharge pulse. The rate coefficient of the ozone-producing reaction, O + O{sub 2} + M {yields} O{sub 3} + M, is estimated to be 3.5 x 10{sup -34} cm{sup 6} s{sup -1}. It is observed that ozone is mostly distributed in the secondary-streamer channel. This suggests that most of the ozone is produced by the secondary streamer, not the primary streamer. After the discharge pulse, ozone diffuses into the background from the secondary-streamer channel. The diffusion coefficient of ozone is estimated to be approximately 0.1 to 0.2 cm{sup 2} s{sup -1}.

  2. Diffuse mode and diffuse-to-filamentary transition in a high pressure nanosecond scale corona discharge under high voltage

    International Nuclear Information System (INIS)

    Tardiveau, P; Moreau, N; Bentaleb, S; Postel, C; Pasquiers, S

    2009-01-01

    The dynamics of a point-to-plane corona discharge induced in high pressure air under nanosecond scale high overvoltage is investigated. The electrical and optical properties of the discharge can be described in space and time with fast and precise current measurements coupled to gated and intensified imaging. Under atmospheric pressure, the discharge exhibits a diffuse pattern like a multielectron avalanche propagating through a direct field ionization mechanism. The diffuse regime can exist since the voltage rise time is much shorter than the characteristic time of the field screening effects, and as long as the local field is higher than the critical ionization field in air. As one of these conditions is not fulfilled, the discharge turns into a multi-channel regime and the diffuse-to-filamentary transition strongly depends on the overvoltage, the point-to-plane gap length and the pressure. When pressure is increased above atmospheric pressure, the diffuse stage and its transition to streamers seem to satisfy similarity rules as the key parameter is the reduced critical ionization field only. However, above 3 bar, neither diffuse avalanche nor streamer filaments are observed but a kind of streamer-leader regime, due to the fact that mechanisms such as photoionization and heat diffusion are not similar to pressure.

  3. Spatial distribution of ozone density in pulsed corona discharges observed by two-dimensional laser absorption method

    International Nuclear Information System (INIS)

    Ono, Ryo; Oda, Tetsuji

    2004-01-01

    The spatial distribution of ozone density is measured in pulsed corona discharges with a 40 μm spatial resolution using a two-dimensional laser absorption method. Discharge occurs in a 13 mm point-to-plane gap in dry air with a pulse duration of 100 ns. The result shows that the ozone density increases for about 100 μs after the discharge pulse. The rate coefficient of the ozone-producing reaction, O + O 2 + M → O 3 + M, is estimated to be 3.5 x 10 -34 cm 6 s -1 . It is observed that ozone is mostly distributed in the secondary-streamer channel. This suggests that most of the ozone is produced by the secondary streamer, not the primary streamer. After the discharge pulse, ozone diffuses into the background from the secondary-streamer channel. The diffusion coefficient of ozone is estimated to be approximately 0.1 to 0.2 cm 2 s -1

  4. A high voltage DC switching power supply of corona discharge for ozone tube

    International Nuclear Information System (INIS)

    Ketkaew, Siseerot

    2007-08-01

    Full text: This paper presents a study of design and construction of a high voltage DC switching power supply for corona generating of ozone gas generating. This supply uses fly back converter at 3 k Vdc 30 khz and controls its operation using PWM techniques. I C TL494 is controlled of the switching. The testing of supply by putting high voltage to ozone gas tube at one-hour, the oxygen quantity 21 % of air, which ozone tube model enables ozone gas generating capacity of 95.2 mgO3/hr

  5. Treatment of hazardous organic wastes using silent discharge plasmas

    International Nuclear Information System (INIS)

    Rosocha, L.A.; Anderson, G.K.; Bechtold, L.A.; Coogan, J.J.; Heck, H.G.; Kang, M.; McCulla, W.H.; Tennant, R.A.; Wantuck, P.J.

    1992-01-01

    During the past two decades, interest in applying non-equilibrium plasmas to the removal of hazardous chemicals from gaseous media has been growing, in particular from heightened concerns over the pollution of our environment and a growing body of environmental regulations. At the Los Alamos National Laboratory, we are currently engaged in a project to develop non-equilibrium plasma technology for hazardous waste treatment. Our present focus is on dielectric-barrier discharges, which are historically called silent electrical discharges. This type of plasma is also named a silent discharge plasma (SDP). We have chosen this method due to its potential for high energy efficiency, its scientific and technological maturity, and its scalability. The SDP process has been demonstrated to be reliable and economical for the industrial-scale synthesis of ozone, where municipal water treatment plants frequently require the on-site generation of thousands of kilograins per day (Eliasson ampersand Kogelschatz). The related methods of corona processing are presently the focus of work at other institutions, particularly for flue gas processing. Both SDP and corona processes are characterized by the production of large quantities of highly reactive free radicals, especially atomic oxygen O(3P) and the hydroxyl OH, in the gaseous medium and their subsequent reaction with contaminants. Our primary objective is to convert hazardous or toxic chemicals into non-hazardous compounds or into materials which are more amenable to treatment. In the ideal case, the hazardous wastes are destructively oxidized to simpler, non-hazardous compounds plus CO2 and H2O. Sometimes the reaction products are still potentially hazardous, but are easily treated by conventional methods to yield non-hazardous products

  6. Experimental and numerical investigation of electrohydrodynamic flow in a point-to-ring corona discharge

    Science.gov (United States)

    Guan, Yifei; Vaddi, Ravi Sankar; Aliseda, Alberto; Novosselov, Igor

    2018-04-01

    An electrohydrodynamic (EHD) flow in a point-to-ring corona configuration is investigated experimentally and via a multiphysics computational model. The model couples the ion transport equation and the Navier-Stokes equations (NSE) to solve for the spatiotemporal distribution of electric field, flow field, and charge density. The numerical simulation results are validated against experimental measurements of the cathode voltage, ion concentration, and velocity profiles. The maximum flow velocity is at the centerline, and it decays rapidly with radial distance due to the viscous and electric forces acting on the partially ionized gas. To understand this coupling, a nondimensional parameter, X , is formulated as the ratio of the local electric force to the inertial term in the NSE. In the region of X ≥1 , the electric force dominates the flow dynamics, while in the X ≪1 region, the balance of viscous and inertial terms yields traditional pipe flow characteristics. This approach expands on the analytical model of Guan et al. by adding a description of the developing flow region. The approach allows the model to be used for the entire EHD domain, providing insights into the near-field flow in the corona region.

  7. Two-photon absorption laser-induced fluorescence of atomic oxygen in the afterglow of pulsed positive corona discharge

    Science.gov (United States)

    Ono, Ryo; Takezawa, Kei; Oda, Tetsuji

    2009-08-01

    Atomic oxygen is measured in the afterglow of pulsed positive corona discharge using time-resolved two-photon absorption laser-induced fluorescence. The discharge occurs in a 14 mm point-to-plane gap in dry air. After the discharge pulse, the atomic oxygen density decreases at a rate of 5×104 s-1. Simultaneously, ozone density increases at almost the same rate, where the ozone density is measured using laser absorption method. This agreement between the increasing rate of atomic oxygen and decreasing rate of ozone proves that ozone is mainly produced by the well-known three-body reaction, O+O2+M→O3+M. No other process for ozone production such as O2(v)+O2→O3+O is observed. The spatial distribution of atomic oxygen density is in agreement with that of the secondary streamer luminous intensity. This agreement indicates that atomic oxygen is mainly produced in the secondary streamer channels, not in the primary streamer channels.

  8. Nanoparticle formation in H2O/N-2 and H2O/Ar mixtures under irradiation by 20 MeV protons and positive corona discharge

    DEFF Research Database (Denmark)

    Imanaka, M.; Tomita, S.; Kanda, S.

    2010-01-01

    To investigate the contribution of ions to gas nucleation, we have performed experiments on the formation of water droplets in H2O/N-2 and H2O/Ar gas mixtures by irradiation with a 20 MeV proton beam and by positive corona discharge. The size of the formed nanoparticles was measured using...

  9. Removal of NO2 and O3 generated from corona discharge in indoor air cleaning with MnO2 catalyst

    International Nuclear Information System (INIS)

    Ge, H; Yu, R; Zhu, Y M; Mi, D

    2013-01-01

    The production rules and removal efficiency of harmful byproducts such as NO 2 and O 3 generated from DC corona discharge in indoor air cleaning were investigated. The production behaviours of NO 2 and O 3 and the relationship between the amount of catalyst (MnO 2 ) and the removal rate of harmful byproducts were experimentally studied. Further, indoor application tests were carried out in a closed room with 90 m 3 . The results showed that the concentrations of NO 2 and O 3 produced by corona discharge linearly increased with discharge time. The NO 2 yield is larger than O 3 by almost one order of magnitude under the same discharge power. To satisfy the demand of Standard of Indoor Air Quality (GB/T18883-2002), the power consumption of unit volume should be less than 1 W m −3 and the catalyst MnO 2 consumptions in positive-negative corona discharge were 200 cm 3 W −1 and 100 cm 3 W −1 , respectively.

  10. Temporal and spatial evolution of EHD particle flow onset in air in a needle-to-plate negative DC corona discharge

    International Nuclear Information System (INIS)

    Mizeraczyk, J; Berendt, A; Podlinski, J

    2016-01-01

    In this paper we present images showing the temporal and spatial evolution of the electrohydrodynamic (EHD) flow of dust particles (cigarette smoke) suspended in still air in a needle-to-plate negative DC corona discharge arrangement just after the corona onset, i.e. in the first stage of development of the EHD particle flow. The experimental apparatus for our study of the EHD flow onset consisted of a needle-to-plate electrode arrangement, high voltage power supply and time-resolved EHD imaging system based on 2D time-resolved particle image velocimetry equipment. The time-resolved flow images clearly show the formation of a ball-like flow structure at the needle tip just after the corona discharge onset, and its evolution into a mushroom-like object moving to the collecting electrode. After a certain time, when the mushroom-like object is still present in the interelectrode gap a second mushroom-like object forms near the needle electrode and starts to move towards the collecting electrode. Before the first mushroom-like object reaches the collecting electrode several similar mushroom-like objects can be formed and presented simultaneously in the interelectrode gap. They look like a series of mushroom-like minijets shot from the needle electrode vicinity towards the collecting electrode. The simultaneous presence of mushroom-like minijets in the interelectrode gap in the corona discharge in particle-seeded air resembles the negative-ion-charged ‘clouds’ (induced by the Trichel pulses) traversing simultaneously the interelectrode gap of the corona discharge in air, predicted a long time ago by Loeb, and Lama and Gallo and recently by Dordizadeh et al . Analysing the time behaviours of the mushroom-like minijets and current waveform in the corona discharge in particle-seeded air, we found that the Trichel pulse trains, formed just after the corona onset initiates the mushroom-like minijets. The first stage of development of the EHD particle flow, the area of

  11. The effect of the configuration of a single electrode corona discharge on its acoustic characteristics

    Science.gov (United States)

    Zhu, Xinlei; Zhang, Liancheng; Huang, Yifan; Wang, Jin; Liu, Zhen; Yan, Keping

    2017-07-01

    A new sparker system based on pulsed spark discharge with a single electrode has already been utilized for oceanic seismic exploration. However, the electro-acoustic energy efficiency of this system is lower than that of arc discharge based systems. A simple electrode structure was investigated in order to improve the electro-acoustic energy efficiency of the spark discharge. Experiments were carried out on an experimental setup with discharge in water driven by a pulsed power source. The voltage-current waveform, acoustic signal and bubble oscillation were recorded when the relative position of the electrode varied. The electro-acoustic energy efficiency was also calculated. The load voltage had a saltation for the invaginated electrode tip, namely an obvious voltage remnant. The more the electrode tip was invaginated, the larger the pressure peaks and first period became. The results show that electrode recessing into the insulating layer is a simple and effective way to improve the electro-acoustic energy efficiency from 2% to about 4%.

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

    Czech Academy of Sciences Publication Activity Database

    Banaschik, R.; Lukeš, Petr; Jablonowski, H.; Hammer, M. U.; Weltmann, K.-D.; Kolb, J.F.

    2015-01-01

    Roč. 84, November (2015), s. 127-135 ISSN 0043-1354 R&D Projects: GA MŠk(CZ) LD14080 Grant - others:European Cooperation in Science and Technology(XE) COST TD1208 Institutional support: RVO:61389021 Keywords : Advanced oxidation * Non-thermal plasma * Ethinylestradiol * Diclofenac * Phenol * Hydroxyl radicals Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 5.991, year: 2015 http://www.sciencedirect.com/science/journal/00431354/84/supp/C

  13. Spatial and temporal evolutions of ozone in a nanosecond pulse corona discharge at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Duten, X; Redolfi, M; Aggadi, N; Vega, A; Hassouni, K, E-mail: duten@lspm.cnrs.fr [LSPM-CNRS UPR 3407, Universite Paris Nord, 90 Avenue J.B. Clement, 93430 Villetaneuse (France)

    2011-10-19

    This paper deals with the experimental determination of the spatial and temporal evolutions of the ozone concentration in an atmospheric pressure pulsed plasma, working in the nanosecond regime. We observed that ozone was produced in the localized region of the streamer. The ozone transport requires a characteristic time well above the millisecond. The numerical modelling of the streamer expansion confirms that the hydrodynamic expansion of the filamentary discharge region during the streamer propagation does not lead to a significant transport of atomic oxygen and ozone. It appears therefore that only diffusional transport can take place, which requires a characteristic time of the order of 50 ms.

  14. Spatial and temporal evolutions of ozone in a nanosecond pulse corona discharge at atmospheric pressure

    Science.gov (United States)

    Duten, X.; Redolfi, M.; Aggadi, N.; Vega, A.; Hassouni, K.

    2011-10-01

    This paper deals with the experimental determination of the spatial and temporal evolutions of the ozone concentration in an atmospheric pressure pulsed plasma, working in the nanosecond regime. We observed that ozone was produced in the localized region of the streamer. The ozone transport requires a characteristic time well above the millisecond. The numerical modelling of the streamer expansion confirms that the hydrodynamic expansion of the filamentary discharge region during the streamer propagation does not lead to a significant transport of atomic oxygen and ozone. It appears therefore that only diffusional transport can take place, which requires a characteristic time of the order of 50 ms.

  15. Spatial and temporal evolutions of ozone in a nanosecond pulse corona discharge at atmospheric pressure

    International Nuclear Information System (INIS)

    Duten, X; Redolfi, M; Aggadi, N; Vega, A; Hassouni, K

    2011-01-01

    This paper deals with the experimental determination of the spatial and temporal evolutions of the ozone concentration in an atmospheric pressure pulsed plasma, working in the nanosecond regime. We observed that ozone was produced in the localized region of the streamer. The ozone transport requires a characteristic time well above the millisecond. The numerical modelling of the streamer expansion confirms that the hydrodynamic expansion of the filamentary discharge region during the streamer propagation does not lead to a significant transport of atomic oxygen and ozone. It appears therefore that only diffusional transport can take place, which requires a characteristic time of the order of 50 ms.

  16. New evidence on the formation of oxidizing species in corona discharge in contact with liquid and their reactions with organic compounds.

    Science.gov (United States)

    Magureanu, M; Dobrin, D; Bradu, C; Gherendi, F; Mandache, N B; Parvulescu, V I

    2016-12-01

    The objective of these investigations is to understand in more detail how organic compounds in water are degraded during plasma treatment. The formation of oxidizing species (ozone (O 3 ), hydrogen peroxide (H 2 O 2 ) and hydroxyl radicals (OH)) in a pulsed corona discharge in contact with liquid is investigated. The degradation of a target organic compound (methylparaben) in aqueous solution was increased when combining plasma treatment with ozonation, using the O 3 generated in the discharge. Enhanced mass transfer of O 3 obtained in this plasma+O 3 configuration leads to a six fold increase of MeP oxidation rate. The evolution of oxidants concentration during treatment of MeP solutions provides information on their consumption in reactions with MeP and its oxidation products. The correlation of MeP degradation results (MeP removal and mineralization) with O 3 consumption and the identified reaction products confirms that although O 3 plays an important role in the degradation, for the mineralization OH radicals have an essential contribution. The concentration of OH radicals is diminished in the solutions containing MeP as compared to plasma-treated water, indicating OH consumption in reactions with the target compound and its degradation products. The concentration of H 2 O 2 in the liquid can be either increased or reduced in the presence of MeP, depending on its initial concentration. On the one hand, decomposition of H 2 O 2 by OH or O 3 is suppressed in the presence of MeP, but on the other hand less OH radicals are available for its formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Feasibility of corona discharge ion mobility spectrometry for direct analysis of samples extracted by dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Jafari, Mohammad T; Riahi, Farhad

    2014-05-23

    The capability of corona discharge ionization ion mobility spectrometry (CD-IMS) for direct analysis of the samples extracted by dispersive liquid-liquid microextraction (DLLME) was investigated and evaluated, for the first time. To that end, an appropriate new injection port was designed and constructed, resulting in possibility of direct injection of the known sample volume, without tedious sample preparation steps (e.g. derivatization, solvent evaporation, and re-solving in another solvent…). Malathion as a test compound was extracted from different matrices by a rapid and convenient DLLME method. The positive ion mobility spectra of the extracted malathion were obtained after direct injection of carbon tetrachloride or methanol solutions. The analyte responses were compared and the statistical results revealed the feasibility of direct analysis of the extracted samples in carbon tetrachloride, resulting in a convenient methodology. The coupled method of DLLME-CD-IMS was exhaustively validated in terms of sensitivity, dynamic range, recovery, and enrichment factor. Finally, various real samples of apple, river and underground water were analyzed, all verifying the feasibility and success of the proposed method for the easy extraction of the analyte using DLLME separation before the direct analysis by CD-IMS. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Synergistic effect of plasmacatalyst and ozone in a pulsed corona discharge reactor on the decomposition of organic pollutants in water

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Muhammad Arif [Applied Chemistry Laboratories, PINSTECH, PO Nilore, Islamabad (Pakistan)

    2003-11-01

    Plasmacatalytic effects of {alpha}-alumina, {gamma}-alumina, and silica gel in a pulsed corona discharge (PCD) reactor on the decomposition of aqueous methylene blue are described. Methylene blue concentration in the effluent was reduced to 23% of the inlet concentration by PCDs in water. Under the same experimental conditions, addition of {alpha}-alumina further reduced it to 8%, {gamma}-alumina to 4%, and silica gel to below the detection limits. PCDs with silica gel were run for >100 h in a continuous flow reactor and methylene blue in the effluent remained below the detection limit. A hybrid system of plasmacatalysis and ozonation is also described. Phenol concentration in the effluent was reduced to 84% of the inlet concentration by PCDs in water. Under the same experimental conditions, addition of either silica gel or ozone further reduced it to around 35%, and simultaneous addition of silica gel and ozone to 14% of inlet concentration. Decolourization of pre-adsorbed methylene blue on silica gel has been demonstrated. Adsorption and stabilization of the chemically active species on silica gel was indicated by experimental evidence. A significant improvement in the rate of decomposition of organic pollutants in water has been realized by hybridizing plasmacatalysis and ozonation in a PCD reactor.

  19. Synergistic effect of plasmacatalyst and ozone in a pulsed corona discharge reactor on the decomposition of organic pollutants in water

    International Nuclear Information System (INIS)

    Malik, Muhammad Arif

    2003-01-01

    Plasmacatalytic effects of α-alumina, γ-alumina, and silica gel in a pulsed corona discharge (PCD) reactor on the decomposition of aqueous methylene blue are described. Methylene blue concentration in the effluent was reduced to 23% of the inlet concentration by PCDs in water. Under the same experimental conditions, addition of α-alumina further reduced it to 8%, γ-alumina to 4%, and silica gel to below the detection limits. PCDs with silica gel were run for >100 h in a continuous flow reactor and methylene blue in the effluent remained below the detection limit. A hybrid system of plasmacatalysis and ozonation is also described. Phenol concentration in the effluent was reduced to 84% of the inlet concentration by PCDs in water. Under the same experimental conditions, addition of either silica gel or ozone further reduced it to around 35%, and simultaneous addition of silica gel and ozone to 14% of inlet concentration. Decolourization of pre-adsorbed methylene blue on silica gel has been demonstrated. Adsorption and stabilization of the chemically active species on silica gel was indicated by experimental evidence. A significant improvement in the rate of decomposition of organic pollutants in water has been realized by hybridizing plasmacatalysis and ozonation in a PCD reactor

  20. Effects of water vapor on flue gas conditioning in the electric fields with corona discharge.

    Science.gov (United States)

    Liqiang, Qi; Yajuan, Zhang

    2013-07-15

    Sulfur dioxide (SO2) removal via pulsed discharge nonthermal plasma in the absence of ammonia was investigated to determine how electrostatic precipitators (ESPs) can effectively collect particulate matter less than 2.5μm in diameter from flue gas. SO2 removal increased as water vapor concentration increased. In a wet-type plasma reactor, directing a gas-phase discharge plasma toward the water film surface significantly enhanced the liquid-phase oxidation of HSO3(-) to SO4(2-). Comparisons of various absorbents revealed that the hydroxyl radical is a key factor in plasma-induced liquid-phase reactions. The resistivity, size distribution, and cohesive force of fly ash at different water vapor contents were measured using a Bahco centrifuge, which is a dust electrical resistivity test instrument, as well as a cohesive force test apparatus developed by the researchers. When water vapor content increased by 5%, fly ash resistivity in flue gas decreased by approximately two orders of magnitude, adhesive force and size increased, and specific surface area decreased. Therefore, ESP efficiency increased. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Decomposition Characteristics of Benzene, Toluene and Xylene in an Atmospheric Pressure DC Corona Discharge II. Characteristics of Deposited By-products and Decomposition Process

    OpenAIRE

    SAKAI, Seiji; TAKAHASHI, Kazuhiro; SATOH, Kohki; ITOH, Hidenori

    2016-01-01

    Gaseous by-products and deposited material obtained from the decomposition of benzene, toluene and xylene in an atmospheric pressure DC corona discharge were minutely investigated by gas chromatograph mass spectrometry and infrared absorption spectroscopy, and the decomposition processes of benzene, toluene and xylene were estimated. It was found that carbon dioxide (CO2), carbon monoxide (CO), formic acid (HCOOH) and formic anhydride ((CHO)2) were the major gaseous by-products from benzene, ...

  2. Stormwater pollution treatment BMP discharge structures.

    Science.gov (United States)

    2014-03-01

    Structural best management practices (BMPs) are used to capture and treat stormwater runoff. Most structural BMPs provide treatment by filtering : runoff through a filter media or collecting it in a detention basin and slowly discharging it over an e...

  3. Effects of water vapor on flue gas conditioning in the electric fields with corona discharge

    Energy Technology Data Exchange (ETDEWEB)

    Liqiang, QI, E-mail: qi_liqiang@163.com; Yajuan, Zhang

    2013-07-15

    Highlights: • The influence mechanism of water vapor humidification on SO{sub 2} oxidation was analyzed. •The effects of water vapor on the specific resistance in fly ash in ESPs were reported. • The effects of water vapor on the size distribution and specific surface area of fly ash were discussed. • The adhesive characteristic of fly ash in different water vapor was experimented. -- Abstract: Sulfur dioxide (SO{sub 2}) removal via pulsed discharge nonthermal plasma in the absence of ammonia was investigated to determine how electrostatic precipitators (ESPs) can effectively collect particulate matter less than 2.5 μm in diameter from flue gas. SO{sub 2} removal increased as water vapor concentration increased. In a wet-type plasma reactor, directing a gas-phase discharge plasma toward the water film surface significantly enhanced the liquid-phase oxidation of HSO{sub 3}{sup −} to SO{sub 4}{sup 2−}. Comparisons of various absorbents revealed that the hydroxyl radical is a key factor in plasma-induced liquid-phase reactions. The resistivity, size distribution, and cohesive force of fly ash at different water vapor contents were measured using a Bahco centrifuge, which is a dust electrical resistivity test instrument, as well as a cohesive force test apparatus developed by the researchers. When water vapor content increased by 5%, fly ash resistivity in flue gas decreased by approximately two orders of magnitude, adhesive force and size increased, and specific surface area decreased. Therefore, ESP efficiency increased.

  4. Corona helps curb losses

    Energy Technology Data Exchange (ETDEWEB)

    Laasonen, M.; Lahtinen, M.; Lustre, L.

    1996-11-01

    The greatest power losses in electricity transmission arise through a phenomenon called load losses. Corona losses caused by the surface discharge of electricity also constitute a considerable cost item. IVS, the nationwide network company, is investigating corona- induced losses, and has also commissioned similar research from IVO International, the Technical Research Centre of Finland (VTT) and from Tampere University of Technology. The research work strives to gain more in-depth knowledge on the phenomenon of frosting and its impact on corona losses. The correct prediction of frost helps reduce corona losses, while also cutting costs considerably. (orig.)

  5. Production mechanism of atomic nitrogen in atmospheric pressure pulsed corona discharge measured using two-photon absorption laser-induced fluorescence

    International Nuclear Information System (INIS)

    Teramoto, Yoshiyuki; Ono, Ryo; Oda, Tetsuji

    2012-01-01

    To study the production mechanism of atomic nitrogen, the temporal profile and spatial distribution of atomic nitrogen are measured in atmospheric pressure pulsed positive corona discharge using two-photon absorption laser-induced fluorescence. The absolute atomic nitrogen density in the streamer filaments is estimated from decay rate of atomic nitrogen in N 2 discharge. The results indicate that the absolute atomic nitrogen density is approximately constant against discharge energy. When the discharge voltage is 21.5 kV, production yield of atomic nitrogen produced by an N 2 discharge pulse is estimated to be 2.9 - 9.8 × 10 13 atoms and the energy efficiency of atomic nitrogen production is estimated to be about 1.8 - 6.1 × 10 16 atoms/J. The energy efficiency of atomic nitrogen production in N 2 discharge is constant against the discharge energy, while that in N 2 /O 2 discharge increases with discharge energy. In the N 2 /O 2 discharge, two-step process of N 2 dissociation plays significant role for atomic nitrogen production.

  6. Mass spectrometric analysis of small negative ions (e/m < 100) produced by Trichel pulse negative corona discharge fed by ozonised air

    OpenAIRE

    Skalny, J.D.; Horvath, G.; Mason, N.

    2007-01-01

    Mass spectrometric analysis of small negative ions (e/m < 100) produced by DC negative corona discharge in ozonised wet air both in flow and flow-stopped regimes was conducted at pressure of 30 kPa. The point-to-plain electrode system has been used. The yield of individual ions is strongly affected by trace concentrations of ozone in both regimes. Ozone concentration greater than 25 ppm is sufficient to completely suppress the appearance of O2- and a NO2- ion as well as theirs clusters in the...

  7. LASERS: Parameters of a trigatron-driven low-pulse-repetition-rate TEA CO2 laser preionised by a surface corona discharge

    Science.gov (United States)

    Aram, M.; Behjat, A.; Shabanzadeh, M.; Mansori, F.

    2007-01-01

    The design of a TEA CO2 laser with UV preionisation by a surface corona discharge is described and the dependences of its average output energy on the gas-flow rate, discharge voltage and pulse repetition rate are presented. The scheme of the electric circuit and the geometry of the pre-ionisation system are considered. The electric circuit is designed to produce only impulse voltage difference between the laser electrodes. The triggering system of the trigatron is used to prevent the appearance of the arc. The dependences of the current, voltage and average output energy on the gas-mixture composition and applied voltages at a low pulse repetition rate are presented. The central output wavelength of the laser was measured with an IR spectrometer. Lasing at two adjacent vibrational-rotational transitions of the CO2 molecule was observed, which demonstrates the possibility of simultaneous lasing at several lines.

  8. Parameters of a trigatron-driven low-pulse-repetition-rate TEA CO2 laser preionised by a surface corona discharge

    International Nuclear Information System (INIS)

    Aram, M; Shabanzadeh, M; Mansori, F; Behjat, A

    2007-01-01

    The design of a TEA CO 2 laser with UV preionisation by a surface corona discharge is described and the dependences of its average output energy on the gas-flow rate, discharge voltage and pulse repetition rate are presented. The scheme of the electric circuit and the geometry of the pre-ionisation system are considered. The electric circuit is designed to produce only impulse voltage difference between the laser electrodes. The triggering system of the trigatron is used to prevent the appearance of the arc. The dependences of the current, voltage and average output energy on the gas-mixture composition and applied voltages at a low pulse repetition rate are presented. The central output wavelength of the laser was measured with an IR spectrometer. Lasing at two adjacent vibrational-rotational transitions of the CO 2 molecule was observed, which demonstrates the possibility of simultaneous lasing at several lines. (lasers)

  9. Treatment Episode Data Set: Discharges (TEDS-D-2011)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Treatment Episode Data Set -- Discharges (TEDS-D) is a national census data system of annual discharges from substance abuse treatment facilities. TEDS-D...

  10. Treatment Episode Data Set: Discharges (TEDS-D-2008)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Treatment Episode Data Set -- Discharges (TEDS-D) is a national census data system of annual discharges from substance abuse treatment facilities. TEDS-D...

  11. Treatment Episode Data Set: Discharges (TEDS-D-2010)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Treatment Episode Data Set -- Discharges (TEDS-D) is a national census data system of annual discharges from substance abuse treatment facilities. TEDS-D...

  12. Treatment Episode Data Set: Discharges (TEDS-D-2007)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Treatment Episode Data Set -- Discharges (TEDS-D) is a national census data system of annual discharges from substance abuse treatment facilities. TEDS-D...

  13. Treatment Episode Data Set: Discharges (TEDS-D-2006)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Treatment Episode Data Set -- Discharges (TEDS-D) is a national census data system of annual discharges from substance abuse treatment facilities. TEDS-D...

  14. Treatment Episode Data Set: Discharges (TEDS-D-2009)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Treatment Episode Data Set -- Discharges (TEDS-D) is a national census data system of annual discharges from substance abuse treatment facilities. TEDS-D...

  15. Carbon Nanotube Fiber Ionization Mass Spectrometry: A Fundamental Study of a Multi-Walled Carbon Nanotube Functionalized Corona Discharge Pin for Polycyclic Aromatic Hydrocarbons Analysis

    Science.gov (United States)

    Nahan, Keaton S.; Alvarez, Noe; Shanov, Vesselin; Vonderheide, Anne

    2017-09-01

    Mass spectrometry continues to tackle many complicated tasks, and ongoing research seeks to simplify its instrumentation as well as sampling. The desorption electrospray ionization (DESI) source was the first ambient ionization source to function without extensive gas requirements and chromatography. Electrospray techniques generally have low efficiency for ionization of nonpolar analytes and some researchers have resorted to methods such as direct analysis in real time (DART) or desorption atmospheric pressure chemical ionization (DAPCI) for their analysis. In this work, a carbon nanotube fiber ionization (nanoCFI) source was developed and was found to be capable of solid phase microextraction (SPME) of nonpolar analytes as well as ionization and sampling similar to that of direct probe atmospheric pressure chemical ionization (DP-APCI). Conductivity and adsorption were maintained by utilizing a corona pin functionalized with a multi-walled carbon nanotube (MWCNT) thread. Quantitative work with the nanoCFI source with a designed corona discharge pin insert demonstrated linearity up to 0.97 (R2) of three target PAHs with phenanthrene internal standard. [Figure not available: see fulltext.

  16. Comparison of Cocaine Detections in Corona Discharge Ionization-Ion Mobility Spectrometry and in Atmospheric Pressure Chemical Ionization-Mass Spectrometry

    International Nuclear Information System (INIS)

    Choi, Sung Seen; Kim, Yun Ki; Kim, Ok Bae; An, Seung Geon; Shin, Myung Won; Maeng, Seug Jin; Choi, Gyu Seop

    2010-01-01

    In this study, we determined the detection limit and reproducibility of the new IMS equipped with corona discharge ionization source using cocaine. The sample was injected with liquid solution to compare the results of APCI-MS. Ion mobility spectrometry (IMS) was a technique originally applied for the detection of trace compounds. IMS has been widely used to detect chemical warfare agents, explosives, and illegal drugs since it combines both high sensitivity (detection limits down to the ng/L range to pg/L range, ppb range and ppt range) and relatively low technical expenditure with high-speed data acquisition. The time required to acquire a single spectrum is in the range of several tens ms. The working principle is based on the drift of ions at ambient pressure under the influence of an external electric field

  17. Comparison of Cocaine Detections in Corona Discharge Ionization-Ion Mobility Spectrometry and in Atmospheric Pressure Chemical Ionization-Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sung Seen; Kim, Yun Ki; Kim, Ok Bae [Sejong University, Seoul (Korea, Republic of); An, Seung Geon; Shin, Myung Won; Maeng, Seug Jin; Choi, Gyu Seop [Wooju Communication and Technology Co., Seoul (Korea, Republic of)

    2010-08-15

    In this study, we determined the detection limit and reproducibility of the new IMS equipped with corona discharge ionization source using cocaine. The sample was injected with liquid solution to compare the results of APCI-MS. Ion mobility spectrometry (IMS) was a technique originally applied for the detection of trace compounds. IMS has been widely used to detect chemical warfare agents, explosives, and illegal drugs since it combines both high sensitivity (detection limits down to the ng/L range to pg/L range, ppb range and ppt range) and relatively low technical expenditure with high-speed data acquisition. The time required to acquire a single spectrum is in the range of several tens ms. The working principle is based on the drift of ions at ambient pressure under the influence of an external electric field.

  18. Decomposition of three volatile organic compounds by nanosecond pulsed corona discharge: Study of by-product formation and influence of high voltage pulse parameters

    Science.gov (United States)

    Jarrige, Julien; Vervisch, Pierre

    2006-06-01

    Increasing concerns over atmospheric pollution has motivated research into technologies able to remove volatile organic compounds (VOC's) from gas streams. The aim of this paper is to understand the chemical and physical mechanisms implied in the decomposition of VOC's in a filamentary nonthermal plasma discharge. Experiments have been carried out on three pollutants (propane, propene, and isopropyl alcohol) in dry air at atmospheric pressure using a wire to cylinder corona discharge generated by a homemade nanosecond rise time high voltage pulse generator. The resulting plasma efficiently destructs propane, propene, or isopropyl alcohol at a concentration of 500 ppm with low specific input energies (less than 500 J/L), but the poor oxidation rate leads to the formation of numerous by-products (acetone, formaldehyde, formic acid, and methyl nitrate) whose concentration can reach some hundreds of ppm. We also investigated the effect of pulse parameters on VOC removal efficiency. Neither pulse peak value nor rise time (in the range of 4-12 ns) appears to have a significant influence on the VOC decomposition rates. Therefore, we believe that the way the energy is deposited in the plasma does not modify the density of active species (radicals, ions) in the streamers. The production of energetic electrons is not enhanced by the external applied field, and the only effective parameter may be the local field in the streamer head, which is almost the same (around 500 Td) whatever the voltage (above the inception value).

  19. Decomposition of three volatile organic compounds by nanosecond pulsed corona discharge: Study of by-product formation and influence of high voltage pulse parameters

    International Nuclear Information System (INIS)

    Jarrige, Julien; Vervisch, Pierre

    2006-01-01

    Increasing concerns over atmospheric pollution has motivated research into technologies able to remove volatile organic compounds (VOC's) from gas streams. The aim of this paper is to understand the chemical and physical mechanisms implied in the decomposition of VOC's in a filamentary nonthermal plasma discharge. Experiments have been carried out on three pollutants (propane, propene, and isopropyl alcohol) in dry air at atmospheric pressure using a wire to cylinder corona discharge generated by a homemade nanosecond rise time high voltage pulse generator. The resulting plasma efficiently destructs propane, propene, or isopropyl alcohol at a concentration of 500 ppm with low specific input energies (less than 500 J/L), but the poor oxidation rate leads to the formation of numerous by-products (acetone, formaldehyde, formic acid, and methyl nitrate) whose concentration can reach some hundreds of ppm. We also investigated the effect of pulse parameters on VOC removal efficiency. Neither pulse peak value nor rise time (in the range of 4-12 ns) appears to have a significant influence on the VOC decomposition rates. Therefore, we believe that the way the energy is deposited in the plasma does not modify the density of active species (radicals, ions) in the streamers. The production of energetic electrons is not enhanced by the external applied field, and the only effective parameter may be the local field in the streamer head, which is almost the same (around 500 Td) whatever the voltage (above the inception value)

  20. Disease specific protein corona

    Science.gov (United States)

    Rahman, M.; Mahmoudi, M.

    2015-03-01

    It is now well accepted that upon their entrance into the biological environments, the surface of nanomaterials would be covered by various biomacromolecules (e.g., proteins and lipids). The absorption of these biomolecules, so called `protein corona', onto the surface of (nano)biomaterials confers them a new `biological identity'. Although the formation of protein coronas on the surface of nanoparticles has been widely investigated, there are few reports on the effect of various diseases on the biological identity of nanoparticles. As the type of diseases may tremendously changes the composition of the protein source (e.g., human plasma/serum), one can expect that amount and composition of associated proteins in the corona composition may be varied, in disease type manner. Here, we show that corona coated silica and polystyrene nanoparticles (after interaction with in the plasma of the healthy individuals) could induce unfolding of fibrinogen, which promotes release of the inflammatory cytokines. However, no considerable releases of inflammatory cytokines were observed for corona coated graphene sheets. In contrast, the obtained corona coated silica and polystyrene nanoparticles from the hypofibrinogenemia patients could not induce inflammatory cytokine release where graphene sheets do. Therefore, one can expect that disease-specific protein coronas can provide a novel approach for applying nanomedicine to personalized medicine, improving diagnosis and treatment of different diseases tailored to the specific conditions and circumstances.

  1. Double streamer phenomena in atmospheric pressure low frequency corona plasma

    International Nuclear Information System (INIS)

    Kim, Dan Bee; Jung, H.; Gweon, B.; Choe, Wonho

    2010-01-01

    Time-resolved images of an atmospheric pressure corona discharge, generated at 50 kHz in a single pin electrode source, show unique positive and negative corona discharge features: a streamer for the positive period and a glow for the negative period. However, unlike in previous reports of dc pulse and low frequency corona discharges, multistreamers were observed at the initial time stage of the positive corona. A possible physical mechanism for the multistreamers is suggested.

  2. Influence of corona charging in cellular polyethylene film

    International Nuclear Information System (INIS)

    Ortega Brana, Gustavo; Magraner, Francisco; Quijano, Alfredo; Llovera Segovia, Pedro

    2011-01-01

    Cellular polymers have recently attracted attention for their property of exhibiting a piezoelectric constant when they are electrically charged. The electrostatic charge generated in the voids by the internal discharges creates and internal macrodipole which is responsible for the piezoelectric effect. Charging by corona discharge is the most used method for cellular polymers. Many works has been published on polypropylene and polyethylene films mainly focused on the required expansion process or on the results obtained for raw cellular materials electrically activated. Our work is based on commercial polyethylene cellular films which have been physically characterized and electrically activated. The effect of thermal treatment, physical uniaxial or biaxial stretching and corona charging was investigated. The new method of corona charging improved the piezoelectric constant under other activation conditions.

  3. Influence of corona charging in cellular polyethylene film

    Energy Technology Data Exchange (ETDEWEB)

    Ortega Brana, Gustavo; Magraner, Francisco; Quijano, Alfredo [Instituto Tecnologico de la Energia (ITE), Av. Juan de la Cierva 24, Parque Tecnologico de Valencia, 46980 Paterna-Valencia (Spain); Llovera Segovia, Pedro, E-mail: gustavo.ortega@ite.es [Instituto de TecnologIa Electrica - Universitat Politecnica de Valencia, Camino de Vera s/n 46022-Valencia (Spain)

    2011-06-23

    Cellular polymers have recently attracted attention for their property of exhibiting a piezoelectric constant when they are electrically charged. The electrostatic charge generated in the voids by the internal discharges creates and internal macrodipole which is responsible for the piezoelectric effect. Charging by corona discharge is the most used method for cellular polymers. Many works has been published on polypropylene and polyethylene films mainly focused on the required expansion process or on the results obtained for raw cellular materials electrically activated. Our work is based on commercial polyethylene cellular films which have been physically characterized and electrically activated. The effect of thermal treatment, physical uniaxial or biaxial stretching and corona charging was investigated. The new method of corona charging improved the piezoelectric constant under other activation conditions.

  4. Treatment of hazardous wastes by DC thermal plasma arc discharge

    International Nuclear Information System (INIS)

    Toru, Iwao; Yafang, Liu; Furuta, N.; Tsuginori, Inaba

    2001-01-01

    The temperature of the DC thermal plasma arc discharge is discussed, and examples of the waste treatment for the inorganic compounds such as fly ash, asbestos, and for the organic compounds such as the toxic dioxines and TBT by using the DC plasma arc discharge are shown. In addition, the plasma treatment by using a radiant power emitted from the DC plasma arc discharge is also shown as another new kind of ones. (authors)

  5. Influence of corona discharge on the ozone budget in the tropical free troposphere: a case study of deep convection during GABRIEL

    Science.gov (United States)

    Bozem, H.; Fischer, H.; Gurk, C.; Schiller, C. L.; Parchatka, U.; Koenigstedt, R.; Stickler, A.; Martinez, M.; Harder, H.; Kubistin, D.; Williams, J.; Eerdekens, G.; Lelieveld, J.

    2014-09-01

    Convective redistribution of ozone and its precursors between the boundary layer (BL) and the free troposphere (FT) influences photochemistry, in particular in the middle and upper troposphere (UT). We present a case study of convective transport during the GABRIEL campaign over the tropical rain forest in Suriname in October 2005. During one measurement flight the inflow and outflow regions of a cumulonimbus cloud (Cb) have been characterized. We identified a distinct layer between 9 and 11 km altitude with enhanced mixing ratios of CO, O3, HOx, acetone and acetonitrile. The elevated O3 contradicts the expectation that convective transport brings low-ozone air from the boundary layer to the outflow region. Entrainment of ozone-rich air is estimated to account for 62% (range: 33-91%) of the observed O3. Ozone is enhanced by only 5-6% by photochemical production in the outflow due to enhanced NO from lightning, based on model calculations using observations including the first reported HOx measurements over the tropical rainforest. The "excess" ozone in the outflow is most probably due to direct production by corona discharge associated with lightning. We deduce a production rate of 5.12 × 1028 molecules O3 flash-1 (range: 9.89 × 1026-9.82 × 1028 molecules O3 flash-1), which is at the upper limit of the range reported previously.

  6. Depolarization current relaxation process of insulating dielectrics after corona poling under different charging conditions

    Directory of Open Access Journals (Sweden)

    J. W. Zhang

    2017-10-01

    Full Text Available As an insulating dielectric, polyimide is favorable for the application of optoelectronics, electrical insulation system in electric power industry, insulating, and packaging materials in space aircraft, due to its excellent thermal, mechanical and electrical insulating stability. The charge storage profile of such insulating dielectric is utmost important to its application, when it is exposed to electron irradiation, high voltage corona discharge or other treatments. These treatments could induce changes in physical and chemical properties of treated samples. To investigate the charge storage mechanism of the insulating dielectrics after high-voltage corona discharge, the relaxation processes responsible for corona charged polyimide films under different poling conditions were analyzed by the Thermally Stimulated Discharge Currents method (TSDC. In the results of thermal relaxation process, the appearance of various peaks in TSDC spectra provided a deep insight into the molecular status in the dielectric material and reflected stored space charge relaxation process in the insulating polymers after corona discharge treatments. Furthermore, the different space charge distribution status under various poling temperature and different discharge voltage level were also investigated, which could partly reflect the influence of the ambiance condition on the functional dielectrics after corona poling.

  7. Depolarization current relaxation process of insulating dielectrics after corona poling under different charging conditions

    Science.gov (United States)

    Zhang, J. W.; Zhou, T. C.; Wang, J. X.; Yang, X. F.; Zhu, F.; Tian, L. M.; Liu, R. T.

    2017-10-01

    As an insulating dielectric, polyimide is favorable for the application of optoelectronics, electrical insulation system in electric power industry, insulating, and packaging materials in space aircraft, due to its excellent thermal, mechanical and electrical insulating stability. The charge storage profile of such insulating dielectric is utmost important to its application, when it is exposed to electron irradiation, high voltage corona discharge or other treatments. These treatments could induce changes in physical and chemical properties of treated samples. To investigate the charge storage mechanism of the insulating dielectrics after high-voltage corona discharge, the relaxation processes responsible for corona charged polyimide films under different poling conditions were analyzed by the Thermally Stimulated Discharge Currents method (TSDC). In the results of thermal relaxation process, the appearance of various peaks in TSDC spectra provided a deep insight into the molecular status in the dielectric material and reflected stored space charge relaxation process in the insulating polymers after corona discharge treatments. Furthermore, the different space charge distribution status under various poling temperature and different discharge voltage level were also investigated, which could partly reflect the influence of the ambiance condition on the functional dielectrics after corona poling.

  8. Electric discharge for treatment of trace contaminants

    Science.gov (United States)

    Flamm, D. L.; Wydeven, T. J. (Inventor)

    1978-01-01

    A radio frequency glow discharge reactor is described for removing trace oxidizable contaminants from an oxygen bearing atmosphere. The reaction chamber is defined by an inner metal electrode facing a dielectric backed by an outer conductive electrode. In one embodiment, a conductive liquid forms the conductor of an outer electrode and cools the dielectric. A resonator coupled to a variable radio frequency source generates the high voltages for creating a glow discharge in the chamber at a predetermined pressure whereby the trace contaminants are oxidized into a few simple non-toxic products that may be easily recovered. The corresponding process for removal of trace contaminants from an oxygen-bearing atmosphere with high efficiency independent of the concentration level is also disclosed.

  9. Treatment of Patients in the Vulnerable Phase (at Discharge or Early After Discharge

    Directory of Open Access Journals (Sweden)

    Yuri Lopatin

    2017-01-01

    Full Text Available The clinical course of heart failure includes a period in which the patient is at increased risk of death or rehospitalisation for HF. This period is termed the “vulnerable phase” and occurs during the peri-acute HF phase, due to microenvironmental changes in the cardiovascular system. Typically, the vulnerability phase starts from the onset of an acute HF event leading to admission, continues through a peri-discharge period and lasts up to 6 months after discharge.These poor post-discharge outcomes also represent a significant socioeconomic burden. This articles reviews treatments that are beneficial in this important phase.

  10. Halloysite nanotubes-titanium dioxide as a solid-phase microextraction coating combined with negative corona discharge-ion mobility spectrometry for the determination of parathion.

    Science.gov (United States)

    Saraji, Mohammad; Jafari, Mohammad Taghi; Mossaddegh, Mehdi

    2016-07-05

    Halloysite nanotubes-titanium dioxide (HNTs-TiO2) as a biocompatible environmentally friendly solid-phase microextraction (SPME) fiber coating was prepared. HNTs-TiO2 was chemically coated on the surface of a fused-silica fiber using a sol-gel process. Parathion as an organophosphorus pesticide was selected as a model compound to investigate the extraction efficiency of the fiber. The extracted analyte was detected by negative corona discharge-ion mobility spectrometer (NCD-IMS). The effective parameters on the extraction efficiency, such as salt effect, extraction temperature and extraction time were investigated and optimized. The extraction efficiency of HNTs-TiO2 fiber was compared with bare-silica (sol-gel based coating without HNTs-TiO2), HNTs, carbon nanotubes and commercial SPME fibers (PA, PDMS, and PDMS-DVB). The HNTs-TiO2 fiber showed highest extraction efficiency among the studied fibers. The intra- and inter-day relative standard deviations were found to be 4.3 and 6.3%, respectively. The limit of detection and limit of quantification values were 0.03 and 0.1 μg L(-1), respectively. The dynamic range of the method was in the range of 0.1-25 μg L(-1). The spiking recoveries were between 85 (±9) and 97 (±6). The SPME-HNTs-TiO2 combined with NCD-IMS was successfully applied for the determination of parathion in apple, strawberry, celery and water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Influence of corona discharge on the ozone budget in the tropical free troposphere: a case study of deep convection during GABRIEL

    Science.gov (United States)

    Bozem, H.; Fischer, H.; Gurk, C.; Schiller, C. L.; Parchatka, U.; Koenigstedt, R.; Stickler, A.; Martinez, M.; Harder, H.; Kubistin, D.; Williams, J.; Eerdekens, G.; Lelieveld, J.

    2014-02-01

    Convective redistribution of ozone and its precursors between the boundary layer (BL) and the free troposphere (FT) influences photochemistry, in particular that of the middle and upper troposphere (UT). We present a case study of convective transport during the GABRIEL campaign over the tropical rain forest in Suriname in October 2005. During a measurement flight on 12 October the inflow and outflow regions of a cumulonimbus cloud (Cb) have been characterized, providing evidence of convective transport. We identified a distinct layer between 9 and 11 km altitude with enhanced mixing ratios of CO, O3, HOx, acetone and acetonitrile. The elevated O3 contradicts the expectation that convective transport brings low ozone air from the boundary layer to the outflow region. The enhanced mixing ratio of ozone in the outflow was mainly of dynamical origin. Entrainment of ozone rich air at the outflow level into the convective outflow accounts for 62% (range: 33-91%) of the observed O3. Ozone is enhanced by only 5-6% by photochemical production in the outflow due to enhanced NO from lightning, based on steady state model calculations, using in-situ observations including the first reported HOx measurements over the tropical rainforest. The "excess" ozone in the outflow is most probably due to direct production by corona discharge associated with lightning. We deduce a production rate of 5.12 × 1028 molecules O3 flash-1 (range: 9.89 × 1026-9.82 × 1028 molecules O3 flash-1), which is at the upper limit of the range of the values reported previously.

  12. Surface modification of steels by electrical discharge treatment in electrolyte

    International Nuclear Information System (INIS)

    Krastev, D.; Paunov, V.; Yordanov, B.; Lazarova, V.

    2013-01-01

    Full text: In this work are discussed some experimental data about the influence of applied electrical discharge treatment in electrolyte on the surface structure of steels. The electrical discharge treatment of steel surface in electrolyte gives a modified structure with specific combination of characteristics in result of nonequilibrium transformations. The modification goes by a high energy thermal process in a very small volume on the metallic surface involving melting, vaporisation, activation and alloying in electrical discharges, and after that cooling of this surface with high rate in the electrolyte. The surface layers obtain a different structure in comparison with the metal matrix and are with higher hardness, wear resistance and corrosion resistance. key words: surface modification, electrical discharge treatment in electrolyte, steels

  13. Hydrophilic property of 316L stainless steel after treatment by atmospheric pressure corona streamer plasma using surface-sensitive analyses

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hamarneh, Ibrahim, E-mail: hamarnehibrahim@yahoo.com [Department of Physics, Faculty of Science, Al-Balqa Applied University, Salt 19117 (Jordan); Pedrow, Patrick [School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA 99164 (United States); Eskhan, Asma; Abu-Lail, Nehal [Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164 (United States)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Surface hydrophilic property of surgical-grade 316L stainless steel was enhanced by Ar-O{sub 2} corona streamer plasma treatment. Black-Right-Pointing-Pointer Hydrophilicity, surface morphology, roughness, and chemical composition before and after plasma treatment were evaluated. Black-Right-Pointing-Pointer Contact angle measurements and surface-sensitive analyses techniques, including XPS and AFM, were carried out. Black-Right-Pointing-Pointer Optimum plasma treatment conditions of the SS 316L surface were determined. - Abstract: Surgical-grade 316L stainless steel (SS 316L) had its surface hydrophilic property enhanced by processing in a corona streamer plasma reactor using O{sub 2} gas mixed with Ar at atmospheric pressure. Reactor excitation was 60 Hz ac high-voltage (0-10 kV{sub RMS}) applied to a multi-needle-to-grounded screen electrode configuration. The treated surface was characterized with a contact angle tester. Surface free energy (SFE) for the treated stainless steel increased measurably compared to the untreated surface. The Ar-O{sub 2} plasma was more effective in enhancing the SFE than Ar-only plasma. Optimum conditions for the plasma treatment system used in this study were obtained. X-ray photoelectron spectroscopy (XPS) characterization of the chemical composition of the treated surfaces confirms the existence of new oxygen-containing functional groups contributing to the change in the hydrophilic nature of the surface. These new functional groups were generated by surface reactions caused by reactive oxidation of substrate species. Atomic force microscopy (AFM) images were generated to investigate morphological and roughness changes on the plasma treated surfaces. The aging effect in air after treatment was also studied.

  14. River water remediation using pulsed corona, pulsed spark or ozonation

    Energy Technology Data Exchange (ETDEWEB)

    Izdebski, T.; Dors, M. [Polish Academy of Sciences, Szewalski Inst. of Fluid Flow Machiney, Fiszera (Poland). Centre for Plasma and Laser Engineering; Mizeraczyk, J. [Polish Academy of Sciences, Szewalski Inst. of Fluid Flow Machiney, Fiszera (Poland). Centre for Plasma and Laser Engineering; Gdynia Maritime Univ., Morska (Poland). Dept. of Marine Electronics

    2010-07-01

    The most common reason for epidemic formation is the pollution of surface and drinking water by wastewater bacteria. Pathogenic microorganisms that form the largest part of this are fecal bacteria, such as escherichia coli (E. coli). Wastewater treatment plants reduce the amount of the fecal bacteria by 1-3 orders of magnitude, depending on the initial number of bacteria. There is a lack of data on waste and drinking water purification by the electrohydraulic discharges method, which causes the destruction and inactivation of viruses, yeast, and bacteria. This paper investigated river water cleaning from microorganisms using pulsed corona, spark discharge and ozonization. The paper discussed the experimental setup and results. It was concluded that ozonization is the most efficient method of water disinfection as compared with pulsed spark and pulsed corona discharges. The pulsed spark discharge in water was capable of killing all microorganism similarly to ozonization, but with much lower energy efficiency. The pulsed corona discharge was found to be the less effective method of water disinfection. 21 refs., 4 figs.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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. (paper)

  16. Ion mobility spectrometric analysis of vaporous chemical warfare agents by the instrument with corona discharge ionization ammonia dopant ambient temperature operation.

    Science.gov (United States)

    Satoh, Takafumi; Kishi, Shintaro; Nagashima, Hisayuki; Tachikawa, Masumi; Kanamori-Kataoka, Mieko; Nakagawa, Takao; Kitagawa, Nobuyoshi; Tokita, Kenichi; Yamamoto, Soichiro; Seto, Yasuo

    2015-03-20

    The ion mobility behavior of nineteen chemical warfare agents (7 nerve gases, 5 blister agents, 2 lachrymators, 2 blood agents, 3 choking agents) and related compounds including simulants (8 agents) and organic solvents (39) was comparably investigated by the ion mobility spectrometry instrument utilizing weak electric field linear drift tube with corona discharge ionization, ammonia doping, purified inner air drift flow circulation operated at ambient temperature and pressure. Three alkyl methylphosphonofluoridates, tabun, and four organophosphorus simulants gave the intense characteristic positive monomer-derived ion peaks and small dimer-derived ion peaks, and the later ion peaks were increased with the vapor concentrations. VX, RVX and tabun gave both characteristic positive monomer-derived ions and degradation product ions. Nitrogen mustards gave the intense characteristic positive ion peaks, and in addition distinctive negative ion peak appeared from HN3. Mustard gas, lewisite 1, o-chlorobenzylidenemalononitrile and 2-mercaptoethanol gave the characteristic negative ion peaks. Methylphosphonyl difluoride, 2-chloroacetophenone and 1,4-thioxane gave the characteristic ion peaks both in the positive and negative ion mode. 2-Chloroethylethylsulfide and allylisothiocyanate gave weak ion peaks. The marker ion peaks derived from two blood agents and three choking agents were very close to the reactant ion peak in negative ion mode and the respective reduced ion mobility was fluctuated. The reduced ion mobility of the CWA monomer-derived peaks were positively correlated with molecular masses among structurally similar agents such as G-type nerve gases and organophosphorus simulants; V-type nerve gases and nitrogen mustards. The slope values of the calibration plots of the peak heights of the characteristic marker ions versus the vapor concentrations are related to the detection sensitivity, and within chemical warfare agents examined the slope values for sarin, soman

  17. Corona Borealis

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    (the Northern Crown; abbrev. CrB, gen. Coronae Borealis; area 179 sq. deg.) A northern constellation which lies between Boötes and Hercules, and culminates at midnight in mid-May. It represents the crown that in Greek mythology was made by Hephaestus, god of fire, and worn by Princess Ariadne of Crete. Its brightest stars were cataloged by Ptolemy (c. AD 100-175) in the Almagest....

  18. Water Treatment Using Plasma Discharge with Variation of Electrode Materials

    Science.gov (United States)

    Chanan, N.; Kusumandari; Saraswati, T. E.

    2018-03-01

    This research studied water treatment using plasma discharge. Plasma generated in this study produced active species that played a role in organic compound decomposition. The plasma reactor consisted of two needle electrodes made from stainless steel, tungsten, aluminium and grafit. It placed approximately 2 mm above the solution and connected with high-AC voltage. A solution of methylene blue used as an organic solution model. Plasma treatment times were 2, 4, 6, 8 and 10 min. The absorbance, temperature and pH of the solution were measured before and after treatment using various electrodes. The best electrode used in plasma discharging for methylene blue absorbance reduction was the graphite electrode, which provided the highest degradation efficiency of 98% at 6 min of treatment time.

  19. Using a nitrogen dielectric barrier discharge for surface treatment

    International Nuclear Information System (INIS)

    Borcia, G; Anderson, C A; Brown, N M D

    2005-01-01

    In this paper, continuing previous work, we report on the installation and the testing of an experimental dielectric barrier discharge (DBD) reactor run in a controlled atmospheric pressure gaseous environment other than air. Here, the effects of a N 2 -DBD treatment on the surface of a test polymer material (UHMW polyethylene) are examined, reported, discussed and compared to results obtained previously following air-DBD treatment. Surface analysis and characterization were performed using x-ray photoelectron spectroscopy, contact angle measurement and scanning electron microscopy before and following the DBD processing described. The discharge parameters used were correlated with the changes in the surface characteristics found following DBD treatments of various durations in a nitrogen atmosphere. The work focuses on the control of the gaseous environment supporting the discharge and on the possibility of overcoming the potentially dominant effect of reactive oxygen-related species, derived from any residual air present. The results obtained underline the very high reactivity of such species in the discharge, but are encouraging in respect of the possibility of the implantation or generation of functional groups other than oxygen-related ones at the surface of interest. The processing conditions concerned simulate 'real' continuous high speed processing, allowing the planning of further experiments, where various gaseous mixtures of the type X + N 2 will be used for controlled surface functionalization

  20. Quantifying Construction Site Sediment Discharge Risk and Treatment Potential

    Science.gov (United States)

    Ferrell, L.; Beighley, R. E.

    2006-12-01

    Dealing with soil erosion and sediment transport can be a significant challenge during the construction process due to the potentially large spatial and temporal extent and conditions of bare soils. Best Management Practices (BMP) are commonly used to eliminate or reduce offsite discharge of sediment. However, few efforts have investigated the time varying risk of sediment discharge from construction sites, which often have dynamic soil conditions and the potential for less than optimal BMP installations. The goal of this research is to improve the design, implementation and effectiveness of sediment and erosion control at construction sites using site specific, temporal distributions of sediment discharge risk. Sediment risk is determined from individual factors leading to sediment expert, such as rainfall frequency, the adequacy of BMP installations, and the extent and duration of bare soil conditions. This research specifically focuses on quantifying: (a) the effectiveness of temporary sediment and control erosion control BMPs in preventing, containing, and/or treating construction site sediment discharge at varying levels of "proper" installation, and (b) sediment discharge potential from construction sites during different phases of construction, (ex., disturbed earth operations). BMPs are evaluated at selected construction sites in southern California and at the Soil Erosion Research Laboratory (SERL) in the Civil and Environmental Engineering department at San Diego State University. SERL experiments are performed on a 3-m by 10-m tilting soil bed with soil depths up to 1 meter, slopes ranging from 0 to 50 percent, and rainfall rates up to 150 mm/hr (6 in/hr). BMP performance is assessed based on experiments where BMPs are installed per manufacture specifications, potential less than optimal installations, and no treatment conditions. Soil conditions are also varied to represent site conditions during different phases of construction (i.e., loose lifts

  1. Treatment of Wastewater by Ozone Produced in Dielectric Barrier Discharge

    Directory of Open Access Journals (Sweden)

    Rita Bhatta

    2015-01-01

    Full Text Available There is rapid diminishing of water resources in many countries due to, for example, population growth and constant reduction in fresh water supply. The sewage wastewater, industrial effluents, and municipal wastewater are directly and indiscriminately discharged into rivers and lakes and thus primarily cause water pollution in Nepal. This has increased the water crisis and also causes environmental deterioration. Therefore, the need for the development of an effective, cheap, and environmentally friendly process for the treatment of wastewater before discharging into aquatic environment has emerged. Treatment by ozone produced from dielectric barrier discharge is one of the emerging technologies for such application. The ozonation process is more effective for disinfection and degradation of organic pollutants from water. The current study describes the treatment of wastewater of selected site within Kathmandu. Results on various physicochemical and microbial parameters of the inlet and outlet samples are discussed. Our results showed slight increase in pH, decrease in chemical oxygen demand, and significant increase in dissolved oxygen after ozonation. Importantly, ozonation caused total reduction of fecal coliform.

  2. Radioactive Liquid Waste Treatment Facility Discharges in 2011

    Energy Technology Data Exchange (ETDEWEB)

    Del Signore, John C. [Los Alamos National Laboratory

    2012-05-16

    This report documents radioactive discharges from the TA50 Radioactive Liquid Waste Treatment Facilities (RLWTF) during calendar 2011. During 2011, three pathways were available for the discharge of treated water to the environment: discharge as water through NPDES Outfall 051 into Mortandad Canyon, evaporation via the TA50 cooling towers, and evaporation using the newly-installed natural-gas effluent evaporator at TA50. Only one of these pathways was used; all treated water (3,352,890 liters) was fed to the effluent evaporator. The quality of treated water was established by collecting a weekly grab sample of water being fed to the effluent evaporator. Forty weekly samples were collected; each was analyzed for gross alpha, gross beta, and tritium. Weekly samples were also composited at the end of each month. These flow-weighted composite samples were then analyzed for 37 radioisotopes: nine alpha-emitting isotopes, 27 beta emitters, and tritium. These monthly analyses were used to estimate the radioactive content of treated water fed to the effluent evaporator. Table 1 summarizes this information. The concentrations and quantities of radioactivity in Table 1 are for treated water fed to the evaporator. Amounts of radioactivity discharged to the environment through the evaporator stack were likely smaller since only entrained materials would exit via the evaporator stack.

  3. TREATMENTS OF PLASMA CORONA RADIATION ON SEAWEED Gracilaria Verrucosa (HUDSON PAPENFUSS: Efforts to increase growth and biomass

    Directory of Open Access Journals (Sweden)

    Filemon Jalu N Putra

    2014-12-01

    Full Text Available Gracilaria verrucosa (Hudson Papenfuss has great potential to be farmed in the water resources in Indonesia. As natural resource, the weed has a major contribution in the field of industry both for human food and health. Efforts have been done intensively to increase the production capacity to meet the market demand especially gelatin, both national and international market. One of them is the application of plasma corona irradiation treatments on the weed to improve developmental pathways. The concept of plasma irradiation performed at atmospheric conditions may impact on nitrogen intrusion pathway that is important element in the growth of the weed. The aims of this study are to assess the potential impact of plasma irradiation in improving the growth of G. verrucosa and thus increase their biomass production. The treatments were done using five different duration of plasma irradiation, which were 2, 4, 6, 8, and 10 minutes at a 0,5mA stable source of voltage and 8kV of electrical current. Observations of growth rate include thallus length and biomass of G. verrucosa , that was observed every week for 28 days. The result showed that the growth of weed exhibited better than those without radiation. The best growth was reached in the group of treatment of 8 minutes irradiation, exhibited 65,91g of biomass and 9.5515% growth rate and length of thallus reached 22,33 cm and daily growth rate of 2.9759%. The lowest growth of the weed occurred in the treatment of 10 minutes irradiation, which was 44,82 g biomass, 8.123% growth rate, 17,13 cm thallus length with a daily growth rate of 1.9942%

  4. Treatment of Wastewater with High Conductivity by Pulsed Discharge Plasma

    Science.gov (United States)

    Wang, Zhaojun; Jiang, Song; Liu, Kefu

    2014-07-01

    A wastewater treatment system was established by means of pulsed dielectric barrier discharge (DBD). The main advantage of this system is that the wastewater is employed as one of the electrodes for the degradation of rhodamine B, which makes use of the high conductivity and lessenes its negative influence on the discharge process. At the same time, the reactive species like ozone and ultraviolet (UV) light generated by the DBD can be utilized for the treatment of wastewater. The effects of some factors like conductivity, peak pulse voltage, discharge frequency and pH values were investigated. The results show that the combination of these reactive species could enhance the degradation of the dye while the ozone played the most important role in the process. The degradation efficiency was enhanced with the increase of energy supplied. The reduction in the concentration of rhodamine B was much more effective with high solution conductivity; under the highest conductivity condition, the degradation rate could rise to 99%.

  5. Treatment of Wastewater with High Conductivity by Pulsed Discharge Plasma

    International Nuclear Information System (INIS)

    Wang Zhaojun; Jiang Song; Liu Kefu

    2014-01-01

    A wastewater treatment system was established by means of pulsed dielectric barrier discharge (DBD). The main advantage of this system is that the wastewater is employed as one of the electrodes for the degradation of rhodamine B, which makes use of the high conductivity and lessenes its negative influence on the discharge process. At the same time, the reactive species like ozone and ultraviolet (UV) light generated by the DBD can be utilized for the treatment of wastewater. The effects of some factors like conductivity, peak pulse voltage, discharge frequency and pH values were investigated. The results show that the combination of these reactive species could enhance the degradation of the dye while the ozone played the most important role in the process. The degradation efficiency was enhanced with the increase of energy supplied. The reduction in the concentration of rhodamine B was much more effective with high solution conductivity; under the highest conductivity condition, the degradation rate could rise to 99%. (plasma technology)

  6. Experimental studies of the formation of cluster ions formed by corona discharge in an atmosphere containing SO2, NH3, and H2O

    DEFF Research Database (Denmark)

    Hvelplund, Preben; Pedersen, Jens Olaf Pepke; Støchkel, Kristian

    2013-01-01

    Abstract We report on studies of ion-induced nucleation in a corona discharge taking place in an atmosphere containing SO2, NH3, and H2O at standard temperature and pressure. Positive ions such as H3O+(H2O)n, NH4+(H2O)n, and H+(H2SO4)(H2O)n and negative ions such as HSO5-(H2O)n, SO4-(H2O)n, HSO4-(H......5-, which has been observed in many studies, in our experiments is contaminated by O2-(HNO3)(H2O) ions, and this may also have been the case in other experiments. Finally an ion with m/z = 232 (where m is the cluster mass in amu and z is the charge state), capable of attaching H2O...

  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. 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....

  9. Discharge and Treatment of Waste Water in Denmark

    DEFF Research Database (Denmark)

    Larsen, Torben

    1990-01-01

    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...... 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....

  10. Pulsed Corona for Sustainable Technology

    International Nuclear Information System (INIS)

    Heesch, E.J.M. van; Pemen, A.J.M.; Yan, K.; Blom, P.P.M.; Huijbrechts, P.A.H.J.; Der Laan, P.C.T. van

    2000-01-01

    Highly active coronas with a peak power of up to 25 MW p/m corona wire and kJ/liter energy densities in the streamer channels can be produced by pulsed power. Since the voltage pulses are short, full breakdown does not occur even though the discharge currents are hundreds of Amperes. A matched pulsed power source can deposit up to 80% of its electrical energy into such a controlled discharge. Reliable and efficient sources characterized by 100 kV,150 ns wide pulses at 1000 Hz have passed 400 hours of operation. The area of applications is growing: VOC control, hot gas cleanup, water and air purification and sterilization. (author)

  11. Treatment Episode Data Set: Discharges (TEDS-D-2006-2011)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Treatment Episode Data Set -- Discharges (TEDS-D) is a national census data system of annual discharges from substance abuse treatment facilities. TEDS-D...

  12. Spectroscopic characteristics of H-alpha/O-I atomic lines generated by nanosecond pulsed corona-like discharge in deionized water

    Czech Academy of Sciences Publication Activity Database

    Pongrác, Branislav; Šimek, Milan; Člupek, Martin; Babický, Václav; Lukeš, Petr

    2018-01-01

    Roč. 51, č. 12 (2018), č. článku 124001. ISSN 0022-3727 R&D Projects: GA ČR(CZ) GA15-12987S Institutional support: RVO:61389021 Keywords : underwater discharge * nanosecond pulsed discharge * time-resolved emission spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.588, year: 2016 http://iopscience.iop.org/article/10.1088/1361-6463/aaabb1/meta

  13. The role of surface chemistry at ceramic/electrolyte intefaces in the generation of pulsed corona discharges in water using porous ceramic-coated rod electrodes

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Člupek, Martin; Babický, Václav; Šunka, Pavel

    2009-01-01

    Roč. 6, č. 11 (2009), s. 719-728 ISSN 1612-8850 R&D Projects: GA AV ČR IAAX00430802 Institutional research plan: CEZ:AV0Z20430508 Keywords : non-thermal plasma * electrical discharge * water * surface chemistry Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.037, year: 2009 http://www3.interscience.wiley.com/cgi-bin/fulltext/122593644/PDFSTART

  14. Treatment of complex electroplating waste by 'zero discharge' technique

    International Nuclear Information System (INIS)

    Khattak, B.Q.; Ram Sankar, P.; Jain, A.K.

    2009-01-01

    Surface treatment processes generate lot of liquid waste, which contains toxic substances and are potentially harmful to the living beings. It is extremely difficult to treat the pollutants where processes and frequencies are not fixed. In Chemical Treatment Facility of RRCAT, surface treatment processes are user dependent and makes the electroplating waste very complicated. Initially the waste was treated by simple chemical transformation technique in which heavy metal ions are converted to hydroxide precipitates. Non metallic ions that contribute much to the plating waste could not be treated by this process. To remove maximum possible pollutants, many experiments were conducted on the laboratory scale. Based on those results, a pilot ion exchange plant of various resins was introduced in the process to achieve disposal quality effluent. Anionic load of Phosphate, Nitrate and fluoride caused frequent anionic bed exhaustions and polymeric network damaging. To avoid this phenomenon a new setup was designed. This pre treatment has the capacity to treat 500 litres per hour connected to a platter with clarifier followed by high pressure carbon and pebbles filters. Analysis of these ions was carried out on the advanced ion chromatography system and is found free of toxic metals, phosphate and fluoride. This effluent can be reused by adding a reverse osmosis system followed by ion exchange system to produce good quality de mineralized water needed for surface treatment activities. In this paper we describe the existing status of effluent treatment facility and future plans for achieving 'zero discharge'. (author)

  15. Liquid discharges from patients undergoing {sup 131}I treatments

    Energy Technology Data Exchange (ETDEWEB)

    Barquero, R. [Servicio de Radiofisica y Proteccion Radiologica, Hospital Universitario Rio Hortega, E-47010 Valladolid (Spain)], E-mail: rbarquero@hurh.sacyl.es; Basurto, F. [Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, E-47010 Valladolid (Spain); Nunez, C. [Servicio de Radiofisica y Proteccion Radiologica, Fundacion Jimenez Diaz, FJD, E-82001 Madrid (Spain); Esteban, R. [Servicio de Radiologia, Hospital Clinico Universitario, E-47005 Valladolid (Spain)

    2008-10-15

    This work discusses the production and management of liquid radioactive wastes as excretas from patients undergoing therapy procedures with {sup 131}I radiopharmaceuticals in Spain. The activity in the sewage has been estimated with and without waste radioactive decay tanks. Two common therapy procedures have been considered, the thyroid cancer (4.14 GBq administered per treatment), and the hyperthyroidism (414 MBq administered per treatment). The calculations were based on measurements of external exposure around the 244 hyperthyroidism patients and 23 thyroid cancer patients. The estimated direct activity discharged to the sewage for two thyroid carcinomas and three hyperthyroidisms was 14.57 GBq and 1.27 GBq, respectively, per week; the annual doses received by the most exposed individual (sewage worker) were 164 {mu}Sv and 13 {mu}Sv, respectively. General equations to calculate the activity as a function of the number of patient treated each week were also obtained.

  16. Observations of different core water cluster ions Y-(H2O)n (Y = O2, HOx, NOx, COx) and magic number in atmospheric pressure negative corona discharge mass spectrometry.

    Science.gov (United States)

    Sekimoto, Kanako; Takayama, Mitsuo

    2011-01-01

    Reliable mass spectrometry data from large water clusters Y(-)(H(2)O)(n) with various negative core ions Y(-) such as O(2)(-), HO(-), HO(2)(-), NO(2)(-), NO(3)(-), NO(3)(-)(HNO(3))(2), CO(3)(-) and HCO(4)(-) have been obtained using atmospheric pressure negative corona discharge mass spectrometry. All the core Y(-) ions observed were ionic species that play a central role in tropospheric ion chemistry. These mass spectra exhibited discontinuities in ion peak intensity at certain size clusters Y(-)(H(2)O)(m) indicating specific thermochemical stability. Thus, Y(-)(H(2)O)(m) may correspond to the magic number or first hydrated shell in the cluster series Y(-)(H(2)O)(n). The high intensity discontinuity at HO(-)(H(2)O)(3) observed was the first mass spectrometric evidence for the specific stability of HO(-)(H(2)O)(3) as the first hydrated shell which Eigen postulated in 1964. The negative ion water clusters Y(-)(H(2)O)(n) observed in the mass spectra are most likely to be formed via core ion formation in the ambient discharge area (760 torr) and the growth of water clusters by adiabatic expansion in the vacuum region of the mass spectrometers (≈1 torr). The detailed mechanism of the formation of the different core water cluster ions Y(-)(H(2)O)(n) is described. Copyright © 2010 John Wiley & Sons, Ltd.

  17. Ion-impact secondary emission in negative corona with photoionization

    Directory of Open Access Journals (Sweden)

    B. X. Lu

    2017-03-01

    Full Text Available A corona discharge measurement system and simulation model are presented to investigate the effects of photoionization and ion-impact secondary emission process in negative corona discharge. The simulation results obtained is shown good agreement with experimental observations. Distribution of electron density along the symmetry axis at three critical moments is shown and the role of photoionization in negative corona discharge is clearly explained. Moreover, the current pulses are also presented under different secondary emission coefficients and the effect of the secondary emission coefficient is discussed.

  18. Plasmachemical Oxidation Processes in Hybrid Gas-Liquid Electrical Discharge Reactor

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Locke, B.R.

    2005-01-01

    Roč. 38, č. 22 (2005), s. 4074-4081 ISSN 0022-3727 Institutional research plan: CEZ:AV0Z20430508 Keywords : Corona discharge * hybrid reactor * hydroxyl radical * ozone * phenol * water treatment Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.957, year: 2005

  19. TBI Patient, Injury, Therapy, and Ancillary Treatments Associated with Outcomes at Discharge and 9 Months Post-discharge

    Science.gov (United States)

    Horn, Susan D.; Corrigan, John D.; Beaulieu, Cynthia L.; Bogner, Jennifer; Barrett, Ryan S.; Giuffrida, Clare G.; Ryser, David K.; Cooper, Kelli; Carroll, Deborah M.; Deutscher, Daniel

    2015-01-01

    Objective To examine associations of patient and injury characteristics, inpatient rehabilitation therapy activities, and neurotropic medications with outcomes at discharge and 9 months post-discharge for patients with traumatic brain injury (TBI) Design Prospective, longitudinal observational study Setting 10 inpatient rehabilitation centers (9 US, 1 Canada) Participants Consecutive patients (n=2130) enrolled between 2008 and 2011, admitted for inpatient rehabilitation after an index TBI injury Interventions Not applicable Main Outcome Measures Rehabilitation length of stay, discharge to home, and Functional Independence Measure (FIM) at discharge and 9 months post-discharge Results The admission FIM Cognitive score was used to create 5 relatively homogeneous subgroups for subsequent analysis of treatment outcomes. Within each subgroup, significant associations were found between outcomes and patient and injury characteristics, time spent in therapy activities, and medications used. Patient and injury characteristics explained on average 35.7% of the variation in discharge outcomes and 22.3% in 9-month outcomes. Adding time spent and level of effort in therapy activities, as well as percent of stay using specific medications, explained approximately 20.0% more variation for discharge outcomes and 12.9% for 9-month outcomes. After patient, injury, and treatment characteristics were used to predict outcomes, center differences added only approximately 1.9% additional variance explained. Conclusions At discharge, greater effort during therapy sessions, time spent in more complex therapy activities, and use of specific medications were associated with better outcomes for patients in all admission FIM Cognitive subgroups. At 9 months post-discharge, similar but less pervasive associations were observed for therapy activities, but not classes of medications. Further research is warranted to examine more specific combinations of therapy activities and medications that

  20. Electrohydraulic Discharges and Nonthermal Plasma for Water Treatment

    Czech Academy of Sciences Publication Activity Database

    Locke, B.R.; Sato, M.; Hoffman, M.R.; Chang, J.S.; Šunka, Pavel

    2006-01-01

    Roč. 45, č. 1 (2006), s. 882-905 ISSN 0888-5885 Institutional research plan: CEZ:AV0Z20430508 Keywords : Electrical discharges * water cleaning * environmental applications * liquid phase reactor Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.518, year: 2006

  1. Nanoparticles formation and deposition in the trichel pulse corona

    International Nuclear Information System (INIS)

    Amirov, R H; Samoylov, I S; Petrov, A A

    2013-01-01

    Cathode erosion in the negative corona discharge has been studied in the point-to-plane electrode configuration with Cu cathodes in the Trichel pulse regime. Redeposition of erosion products has been found on the cathode surface in form of agglomerates of 10-nm nanoparticles. Nanocraters and nanoparticles formation in the negative corona discharge has been considered in frames of electro-explosive mechanism of cathode erosion. According to this mechanism the cathode erosion is performed as a consequence of elementary erosion events each of which is caused by a Trichel pulse. A 1-dimentional model of corona-produced nanoparticles dynamics in the gap was elaborated. According to results of the simulation, the redeposition is explained by charging of the nanoparticles due to positive ions adsorption and thermionic emission. The size, temperature and initial velocity of the aerosol nanoparticles have the decisive action on redeposition in the negative corona discharge.

  2. Polypyrrole/montmorillonite nanocomposite as a new solid phase microextraction fiber combined with gas chromatography–corona discharge ion mobility spectrometry for the simultaneous determination of diazinon and fenthion organophosphorus pesticides

    International Nuclear Information System (INIS)

    Jafari, Mohammad T.; Saraji, Mohammad; Sherafatmand, Hossein

    2014-01-01

    Graphical abstract: - Highlights: • A novel SPME fiber based on polypyrrole/montmorillonite nanocomposites with highly porous and thermal stability was prepared. • The two-dimensional separation technique, GC–IMS, was used for analysis of complex matrices extracted by SPME. • Direct and simultaneous analysis of diazinon and fenthion in various real samples was successfully accomplished. - Abstract: A novel solid phase microextraction (SPME) fiber was prepared and coupled with gas chromatography corona discharge ion mobility spectrometry (GC–CD–IMS) based on polypyrrole/montmorillonite nanocomposites for the simultaneous determination of diazinon and fenthion. The nanocomposite polymer was coated using a three-electrode electrochemical system and directly deposited on a Ni–Cr wire by applying a constant potential. The scanning electron microscopy images revealed that the new fiber exhibited a rather porous and homogenous surface. The thermal stability of the fabricated fiber was investigated by thermogravimetric analysis. The effects of different parameters influencing the extraction efficiency such as extraction temperature and time, salt addition, stirring rate, the amount of nanoclay, and desorption temperature were investigated and optimized. The method was exhaustively evaluated in terms of sensitivity, recovery, and reproducibility. The linearity ranges of 0.05–10 and 0.08–10 μg L −1 , and the detection limits of 0.020 and 0.035 μg L −1 were obtained for diazinon and fenthion, respectively. The relative standard deviation values were calculated to be lower than 5% and 8% for intra-day and inter-day, respectively. Finally, the developed method was applied to determine the diazinon and fenthion (as model compounds) in cucumber, lettuce, apple, tap and river water samples. The satisfactory recoveries revealed the capability of the two-dimensional separation technique (retention time in GC and drift time in IMS) for the analysis of complex

  3. Polypyrrole/montmorillonite nanocomposite as a new solid phase microextraction fiber combined with gas chromatography–corona discharge ion mobility spectrometry for the simultaneous determination of diazinon and fenthion organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Jafari, Mohammad T., E-mail: jafari@cc.iut.ac.ir; Saraji, Mohammad; Sherafatmand, Hossein

    2014-03-01

    Highlights: • A novel SPME fiber based on polypyrrole/montmorillonite nanocomposites with highly porous and thermal stability was prepared. • The two-dimensional separation technique, GC–IMS, was used for analysis of complex matrices extracted by SPME. • Direct and simultaneous analysis of diazinon and fenthion in various real samples was successfully accomplished. Abstract: A novel solid phase microextraction (SPME) fiber was prepared and coupled with gas chromatography corona discharge ion mobility spectrometry (GC–CD–IMS) based on polypyrrole/montmorillonite nanocomposites for the simultaneous determination of diazinon and fenthion. The nanocomposite polymer was coated using a three-electrode electrochemical system and directly deposited on a Ni–Cr wire by applying a constant potential. The scanning electron microscopy images revealed that the new fiber exhibited a rather porous and homogenous surface. The thermal stability of the fabricated fiber was investigated by thermogravimetric analysis. The effects of different parameters influencing the extraction efficiency such as extraction temperature and time, salt addition, stirring rate, the amount of nanoclay, and desorption temperature were investigated and optimized. The method was exhaustively evaluated in terms of sensitivity, recovery, and reproducibility. The linearity ranges of 0.05–10 and 0.08–10 μg L⁻¹, and the detection limits of 0.020 and 0.035 μg L⁻¹ were obtained for diazinon and fenthion, respectively. The relative standard deviation values were calculated to be lower than 5% and 8% for intra-day and inter-day, respectively. Finally, the developed method was applied to determine the diazinon and fenthion (as model compounds) in cucumber, lettuce, apple, tap and river water samples. The satisfactory recoveries revealed the capability of the two-dimensional separation technique (retention time in GC and drift time in IMS) for the analysis of complex matrices extracted by

  4. Collision-Induced Dissociation Study of Strong Hydrogen-Bonded Cluster Ions Y-(HF) n (Y=F, O2) Using Atmospheric Pressure Corona Discharge Ionization Mass Spectrometry Combined with a HF Generator.

    Science.gov (United States)

    Sakamoto, Kenya; Sekimoto, Kanako; Takayama, Mitsuo

    2017-01-01

    Hydrogen fluoride (HF) was produced by a homemade HF generator in order to investigate the properties of strong hydrogen-bonded clusters such as (HF) n . The HF molecules were ionized in the form of complex ions associated with the negative core ions Y - produced by atmospheric pressure corona discharge ionization (APCDI). The use of APCDI in combination with the homemade HF generator led to the formation of negative-ion HF clusters Y - (HF) n (Y=F, O 2 ), where larger clusters with n ≥4 were not detected. The mechanisms for the formation of the HF, F - (HF) n , and O 2 - (HF) n species were discussed from the standpoints of the HF generator and APCDI MS. By performing energy-resolved collision-induced dissociation (CID) experiments on the cluster ions F - (HF) n ( n =1-3), the energies for the loss of HF from F - (HF) 3 , F - (HF) 2 , and F - (HF) were evaluated to be 1 eV or lower, 1 eV or higher, and 2 eV, respectively, on the basis of their center-of-mass energy ( E CM ). These E CM values were consistent with the values of 0.995, 1.308, and 2.048 eV, respectively, obtained by ab initio calculations. The stability of [O 2 (HF) n ] - ( n =1-4) was discussed on the basis of the bond lengths of O 2 H-F - (HF) n and O 2 - H-F(HF) n obtained by ab initio calculations. The calculations indicated that [O 2 (HF) 4 ] - separated into O 2 H and F - (HF) 3 .

  5. Development of a new corona discharge based ion source for high resolution time-of-flight chemical ionization mass spectrometer to measure gaseous H2SO4 and aerosol sulfate

    Science.gov (United States)

    Zheng, Jun; Yang, Dongsen; Ma, Yan; Chen, Mindong; Cheng, Jin; Li, Shizheng; Wang, Ming

    2015-10-01

    A new corona discharge (CD) based ion source was developed for a commercial high-resolution time-of-flight chemical ionization mass spectrometer (HRToF-CIMS) (Aerodyne Research Inc.) to measure both gaseous sulfuric acid (H2SO4) and aerosol sulfate after thermal desorption. Nitrate core ions (NO3-) were used as reagent ions and were generated by a negative discharge in zero air followed by addition of excess nitrogen dioxide (NO2) to convert primary ions and hydroxyl radicals (OH) into NO3- ions and nitric acid (HNO3). The CD-HRToF-CIMS showed no detectable interference from hundreds parts per billion by volume (ppbv) of sulfur dioxide (SO2). Unlike the atmospheric pressure ionization (API) ToF-CIMS, the CD ion source was integrated onto the ion-molecule reaction (IMR) chamber and which made it possible to measure aerosol sulfate by coupling to a filter inlet for gases and aerosols (FIGAERO). Moreover, compared with a quadrupole-based mass spectrometer, the desired HSO4- signal was detected by its exact mass of m/z 96.960, which was well resolved from the potential interferences of HCO3-ṡ(H2O)2 (m/z 97.014) and O-ṡH2OṡHNO3 (m/z 97.002). In this work, using laboratory-generated standards the CD-HRToF-CIMS was demonstrated to be able to detect as low as 3.1 × 105 molecules cm-3 gaseous H2SO4 and 0.5 μg m-3 ammonium sulfate based on 10-s integration time and two times of the baseline noise. The CD ion source had the advantages of low cost and a simple but robust structure. Since the system was non-radioactive and did not require corrosive HNO3 gas, it can be readily field deployed. The CD-HRToF-CIMS can be a powerful tool for both field and laboratory studies of aerosol formation mechanism and the chemical processes that were critical to understand the evolution of aerosols in the atmosphere.

  6. Time dependent argon glow discharge treatment of Al-alloy

    Indian Academy of Sciences (India)

    The energy dispersive microanalysis by X-rays (EDX) is used to determine ... surface preparation of vacum components and vacuum system of any size. ... In this work, samples of aluminium alloy are treated under dc glow discharge .... (ii) For ałuninium, iron and germanium, relative weight percentage decreases or in-.

  7. Corona SDK hotshot

    CERN Document Server

    Flanagan, Nevin

    2013-01-01

    Using a project based approach you will learn the coolest aspects of Corona SDK development. Each project contains step bystep explanations, diagrams, screenshots, and downloadable materials.This book is for users who already have completed at least one simple app using Corona and are familiar with mobile development using another platform and have done Lua programming in another context. Knowledge of the basic functions of Corona routines, as well as an understanding of the Lua programming language's syntax and common libraries, is assumed throughout.

  8. Moving Clinical Deliberations on Administrative Discharge in Drug Addiction Treatment Beyond Moral Rhetoric to Empirical Ethics.

    Science.gov (United States)

    Williams, Izaak L

    2016-01-01

    Patients' admission to modern substance use disorder treatment comes with the attendant risk of being discharged from treatment-a widespread practice. This article describes the three mainstream theories of addiction that operate as a reference point for clinicians in reasoning about a decision to discharge a patient from treatment. The extant literature is reviewed to highlight the pathways that patients follow after administrative discharge. Little scientific research has been done to investigate claims and hypotheses about the therapeutic function of AD, which points to the need for empirical ethics to inform clinical addictions practice. Copyright 2016 The Journal of Clinical Ethics. All rights reserved.

  9. 42 CFR 412.104 - Special treatment: Hospitals with high percentage of ESRD discharges.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Special Treatment of Certain Facilities Under the Prospective Payment System for Inpatient... established that ESRD beneficiary discharges, excluding discharges classified into MS-DRG 652 (Renal Failure...

  10. Hazardous gas treatment using atmospheric pressure microwave discharges

    International Nuclear Information System (INIS)

    Mizeraczyk, Jerzy; Jasinski, Mariusz; Zakrzewski, Zenon

    2005-01-01

    Atmospheric pressure microwave discharge methods and devices used for producing non-thermal plasmas for control of gaseous pollutants are described in this paper. The main part of the paper is concerned with microwave torch discharges (MTDs). Results of laboratory experiments on plasma abatement of several volatile organic compounds (VOCs) in their mixtures with either synthetic air or nitrogen in low (∼100 W) and moderate (200-400 W) microwave torch plasmas at atmospheric pressure are presented. Three types of MTD generators, i.e. low-power coaxial-line-based MTDs, moderate-power waveguide-based coaxial-line MTDs and moderate-power waveguide-based MTDs were used. The gas flow rate and microwave (2.45 GHz) power delivered to the discharge were in the range of 1-3 litre min -1 and 100-400 W, respectively. The concentrations of the processed gaseous pollutants were from several to several tens of per cent. The results showed that the MTD plasmas fully decomposed the VOCs at a relatively low energy cost. The energy efficiency of decomposition of several gaseous pollutants reached 1000 g (kW-h) -1 . This suggests that MTD plasmas can be useful tools for decomposition of highly concentrated VOCs

  11. Micro Corona Ionizer as an Ozone Source for Bacterial Cell Lysis

    Science.gov (United States)

    Lee, Eun-Hee; Lim, Hyun Jeong; Chua, Beelee; Son, Ahjeong

    2015-04-01

    DNA extraction is a critical process of DNA assays including polymerase chain reaction (PCR), microarrays, molecular cloning, and DNA hybridization which has been well established and can be implemented by commercial kits. DNA extraction involves cell lysis, precipitation, and purification through the combination of physical and chemical processes. Cell lysis is essential to high DNA recovery yield which can be achieved via a variety of physical, chemical, and enzymatic methods. However, these methods were originally developed for bioassays that were labor intensive, time consuming, and vulnerable to contamination and inhibition. Here, we proposed to employ a micro corona ionizer as an ozone source to lyse bacterial cells. Ozone has been well known and used as a disinfectant which allows cell lysis and DNA extraction. Previously, we have shown that a micro corona ionizer is capable of generating a significant amount of ozone. In this study, we employed the micro corona ionizer for the bacterial cell lysis which consists of a 50 μm diameter cantilever wire as the discharge cathode and a 50 μm thick copper foil as anode. Applied voltages varied from 1900 to 2200 V with corresponding corona currents from 16 to 28 μA. The resultant ozone (concentration > 0.14 ppm) generated from the micro corona ionizer was bubbled into the sample via a miniature pump. We demonstrated the cell lysis of Pseudomonas putida as the target bacterium using the micro corona ionizer. At a flow rate of 38 ml/min and applied corona voltage of 2000 V, 98.5 ± 0.2% lysis (normalized to sonication result) was achieved after 10 min. In comparison, untreated and air-treated samples showed normalized % lysis of 11.9 ± 2.4 and 36.1 ± 1.7%, respectively. We also showed that the cell lysis efficiency could be significantly increased by increasing the flow rate and the applied corona voltage. By comparing the experimental results for continuous and pulsed treatment, we verified that the percentage of

  12. Assessment of wastewater treatment facility compliance with decreasing ammonia discharge limits using a regression tree model.

    Science.gov (United States)

    Suchetana, Bihu; Rajagopalan, Balaji; Silverstein, JoAnn

    2017-11-15

    A regression tree-based diagnostic approach is developed to evaluate factors affecting US wastewater treatment plant compliance with ammonia discharge permit limits using Discharge Monthly Report (DMR) data from a sample of 106 municipal treatment plants for the period of 2004-2008. Predictor variables used to fit the regression tree are selected using random forests, and consist of the previous month's effluent ammonia, influent flow rates and plant capacity utilization. The tree models are first used to evaluate compliance with existing ammonia discharge standards at each facility and then applied assuming more stringent discharge limits, under consideration in many states. The model predicts that the ability to meet both current and future limits depends primarily on the previous month's treatment performance. With more stringent discharge limits predicted ammonia concentration relative to the discharge limit, increases. In-sample validation shows that the regression trees can provide a median classification accuracy of >70%. The regression tree model is validated using ammonia discharge data from an operating wastewater treatment plant and is able to accurately predict the observed ammonia discharge category approximately 80% of the time, indicating that the regression tree model can be applied to predict compliance for individual treatment plants providing practical guidance for utilities and regulators with an interest in controlling ammonia discharges. The proposed methodology is also used to demonstrate how to delineate reliable sources of demand and supply in a point source-to-point source nutrient credit trading scheme, as well as how planners and decision makers can set reasonable discharge limits in future. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Why the negative corona current in air decreases?

    International Nuclear Information System (INIS)

    Pavlik, M.; Skalny, J.D.; Strelle, D.

    1996-01-01

    The time dependence of negative corona current I, called by Gagarin like 'relaxing of CV-characteristics', is a observed phenomena. The observed phenomena was explained by two theoretical models considering the ion-molecule and chemical reactions in the negative corona discharges in air, especially the ozone production. In the presented paper the discrepancies of above mentioned models, re-examination the earlier experimental data and presumptions used in models in a light the latest experimentally confirmed facts are discussed

  14. Corona-discharge air-purification system

    Science.gov (United States)

    Wydeven, T. J.; Flamm, D. L.

    1979-01-01

    Plasma reaction chamber removes trace contaminants from spacecraft, submarines, and other closed environments by oxidizing contaminants to produce carbon dioxide and water. Contaminants are alcohols, esters, hydrogen sulfide, and ammonia. Others are lubricant solvents such as Freons, aromatics, and Ketones. Contaminants are removed from chamber by scrubber.

  15. Water cleaning by pulsed corona discharges

    NARCIS (Netherlands)

    Grabowski, L.R.; Veldhuizen, van E.M.; Rutgers, W.R.

    2004-01-01

    Direct electrical energization methods for water cleaning are under investigation in the framework of the ytriD-project1. The emphasis of the first stage of the project is optimization of the reactor configuration regarding the energy efficiency. A comparison is made between a batch reactor and an

  16. Vehicle exhaust treatment using electrical discharge and materials chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Tonkyn, R.G.; Balmer, M.L.; Barlow, S.E.; Orlando, T.M. [Pacific Northwest National Lab., Richland, WA (United States); Goulette, D.; Hoard, J. [Ford Motor Co., Dearborn, MI (United States). Scientific Research Lab.

    1997-12-31

    Current 3-way catalytic converters have proven quite effective at removing NO{sub x} from the exhaust of spark ignition vehicles operating near stoichiometric air-to-fuel ratios. However, diesel engines typically operate at very high air-to-fuel ratios. Under such lean burn conditions current catalytic converters are ineffective for NO{sub x} removal. As a result, considerable effort has been made to develop a viable lean NO{sub x} catalyst. Although some materials have been shown to reduce NO{sub x} under lean burn conditions, none exhibit the necessary activity and stability at the high temperatures and humidities found in typical engine exhaust,. As a result, alternative technologies are being explored in an effort to solve the so-called lean NO{sub x} problem. Packed-bed barrier discharge systems are well suited to take advantage of plasma-surface interactions due to the large number of contaminant surface collisions in the bed. The close proximity of the active surface to transient species produced by the plasma may lead to favorable chemistry at considerably lower temperatures than required by thermal catalysts. The authors present data in this paper illustrating that the identity and surface properties of the packing material can alter the discharge-driven chemistry in synthetic leanburn exhaust mixtures. Results using non-porous glass beads as the packing material suggest the limits of NO{sub x} reduction using purely gas phase discharge chemistry. By comparison, encouraging results are reported for several alternative packing materials.

  17. Statistical characteristic in time-domain of direct current corona-generated audible noise from conductor in corona cage

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xuebao, E-mail: lxb08357x@ncepu.edu.cn; Cui, Xiang, E-mail: x.cui@ncepu.edu.cn; Ma, Wenzuo; Bian, Xingming; Wang, Donglai [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206 (China); Lu, Tiebing, E-mail: tiebinglu@ncepu.edu.cn [Beijing Key Laboratory of High Voltage and EMC, North China Electric Power University, Beijing 102206 (China); Hiziroglu, Huseyin [Department of Electrical and Computer Engineering, Kettering University, Flint, Michigan 48504 (United States)

    2016-03-15

    The corona-generated audible noise (AN) has become one of decisive factors in the design of high voltage direct current (HVDC) transmission lines. The AN from transmission lines can be attributed to sound pressure pulses which are generated by the multiple corona sources formed on the conductor, i.e., transmission lines. In this paper, a detailed time-domain characteristics of the sound pressure pulses, which are generated by the DC corona discharges formed over the surfaces of a stranded conductors, are investigated systematically in a laboratory settings using a corona cage structure. The amplitude of sound pressure pulse and its time intervals are extracted by observing a direct correlation between corona current pulses and corona-generated sound pressure pulses. Based on the statistical characteristics, a stochastic model is presented for simulating the sound pressure pulses due to DC corona discharges occurring on conductors. The proposed stochastic model is validated by comparing the calculated and measured A-weighted sound pressure level (SPL). The proposed model is then used to analyze the influence of the pulse amplitudes and pulse rate on the SPL. Furthermore, a mathematical relationship is found between the SPL and conductor diameter, electric field, and radial distance.

  18. Statistical characteristic in time-domain of direct current corona-generated audible noise from conductor in corona cage

    Science.gov (United States)

    Li, Xuebao; Cui, Xiang; Lu, Tiebing; Ma, Wenzuo; Bian, Xingming; Wang, Donglai; Hiziroglu, Huseyin

    2016-03-01

    The corona-generated audible noise (AN) has become one of decisive factors in the design of high voltage direct current (HVDC) transmission lines. The AN from transmission lines can be attributed to sound pressure pulses which are generated by the multiple corona sources formed on the conductor, i.e., transmission lines. In this paper, a detailed time-domain characteristics of the sound pressure pulses, which are generated by the DC corona discharges formed over the surfaces of a stranded conductors, are investigated systematically in a laboratory settings using a corona cage structure. The amplitude of sound pressure pulse and its time intervals are extracted by observing a direct correlation between corona current pulses and corona-generated sound pressure pulses. Based on the statistical characteristics, a stochastic model is presented for simulating the sound pressure pulses due to DC corona discharges occurring on conductors. The proposed stochastic model is validated by comparing the calculated and measured A-weighted sound pressure level (SPL). The proposed model is then used to analyze the influence of the pulse amplitudes and pulse rate on the SPL. Furthermore, a mathematical relationship is found between the SPL and conductor diameter, electric field, and radial distance.

  19. Plasma treatment of polyethylene tubes in continuous regime using surface dielectric barrier discharge with water electrodes

    Science.gov (United States)

    Galmiz, Oleksandr; Zemánek, Miroslav; Pavliňák, David; Černák, Mirko

    2018-05-01

    Combining the surface dielectric barrier discharges generated in contact with water based electrolytes, as the discharge electrodes, we have designed a new type of surface electric discharge, generating thin layers of plasma which propagate along the treated polymer surfaces. The technique was aimed to achieve uniform atmospheric pressure plasma treatment of polymeric tubes and other hollow bodies. The results presented in this work show the possibility of such system to treat outer surface of polymer materials in a continuous mode. The technical details of experimental setup are discussed as well as results of treatment of polyethylene tubes are shown.

  20. Treatment of nitridation by microwave post discharge plasma in an AISI 4140 steel

    International Nuclear Information System (INIS)

    Medina F, A.; Rodriguez L, V.; Zamora R, L.; Oseguera P, J.

    1998-01-01

    The objective of this work is to determine through X-ray diffraction, microhardness measurement and scanning electron microscopy those main operation parameters of the microwave post discharge treatment (temperature of treatment, gas mixture and permanence time) nitriding an AISI 4140 steel and to characterize the compact layer of nitrides formed during the treatment. (Author)

  1. NOx removal characteristics of corona radical shower with ammonia and methylamine radical injections

    Energy Technology Data Exchange (ETDEWEB)

    Urashima, K.; Ara, M.; Chang, J.S. [McMaster Univ., Hamilton, ON (Canada). Dept. of Engineering Physics; Uchida, Y. [Aichi Inst. of Technology, (Japan). Dept. of Engineering

    2010-07-01

    Air pollutants such as nitrogen oxides (NOx) and sulfur oxides (SOx) are the major cause of acid rain. There are different types of NOx and SOx conversion techniques such as wet scrubber, selective catalytic reactor, sorbent injection, and low NOx burner. Non-thermal plasma techniques have also been utilized in commercial plants, but the energy efficiency of the non-thermal plasma reactors have not yet been optimized. The direct plasma treatments of flue gases including, the electron beam, barrier discharge and pulsed corona reactors, may lose input energy to activate unwanted components of flue gases such as carbon dioxide (CO{sub 2}) and nitrogen (N{sub 2}). The corona discharge ammonia radical shower system has demonstrated significant NOx removal with higher energy efficiency for large bench scale and pilot plant tests for combustion exhausts. An experiment has also demonstrated that methane can replace ammonia as an injection gas with less NOx removal efficiency. This paper presented an experimental investigation that compared methylamine radical injection with traditional ammonia and methane radical injections. The paper discussed the bench scale test facilities and corona radical shower plasma reactor. It was concluded that the processes to form ammonium nitrate could be observed from trace white solid particles deposited on the reactor wall as observed by scanning electron microscopy pictures. 10 refs., 5 figs., 2 appendices.

  2. Corona-induced graft polymerization for surface modification of porous polyethersulfone membranes

    International Nuclear Information System (INIS)

    Zhu Liping; Zhu Baoku; Xu Li; Feng Yongxiang; Liu Fu; Xu Youyi

    2007-01-01

    Graft polymerization of acrylic acid (AA) onto porous polyethersulfone (PES) membrane surfaces was developed using corona discharge in atmospheric ambience as an activation process followed by polymerization of AA in aqueous solution. The effects of the corona parameters and graft polymerization conditions on grafting yield (GY) of AA were investigated. The grafting of AA on the PES membranes was confirmed by ATR-FTIR and X-ray photoelectron spectroscopy (XPS) analysis. Porosimetry measurements indicate the average pore diameters and porosities of the modified membranes decrease with the increase of the GY. The hydrophilicity and surface wetting properties of the original and modified membranes were evaluated by observing the dynamic changes of water contact angles. It is found that the grafting of AA occurs not only on the membrane surfaces, but also on the pore walls of the cells inside the membrane. The permeability experiments of protein solution reveal that the grafting of PAA endows the modified membranes with enhanced fluxes and anti-fouling properties. The optimized GY of AA is in the range of 150-200 μg/cm 2 . In addition, the tensile experiments show the corona discharge treatment with the power lower than 150 W yields little damage to the mechanical strength of the membranes

  3. Predictors of premature discontinuation of outpatient treatment after discharge of patients with posttraumatic stress disorder.

    Science.gov (United States)

    Wang, Hee Ryung; Woo, Young Sup; Jun, Tae-Youn; Bahk, Won-Myong

    2015-01-01

    This study aimed to examine the sociodemographic and disease-related variables associated with the premature discontinuation of psychiatric outpatient treatment after discharge among patients with noncombat-related posttraumatic stress disorder. We retrospectively reviewed the medical records of patients who were discharged with a diagnosis of posttraumatic stress disorder. Fifty-five percent of subjects (57/104) prematurely discontinued outpatient treatment within 6 months of discharge. Comparing sociodemographic variables between the 6-month non-follow-up group and 6-month follow-up group, there were no variables that differed between the two groups. However, comparing disease-related variables, the 6-month follow-up group showed a longer hospitalization duration and higher Global Assessment of Function score at discharge. The logistic regression analysis showed that a shorter duration of hospitalization predicted premature discontinuation of outpatient treatment within 6 months of discharge. The duration of psychiatric hospitalization for posttraumatic stress disorder appeared to influence the premature discontinuation of outpatient treatment after discharge.

  4. National Pollution Discharge Elimination System (NPDES) Wastewater Treatment Plant Outfall Points, Region 9, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES outfalls/dischargers for waste water treatment plants which generally represent the site of the discharge....

  5. National Pollution Discharge Elimination System (NPDES) Wastewater Treatment Plant Outfall Points, Region 9, 2007, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES outfalls/dischargers for waste water treatment plants which generally represent the site of the discharge....

  6. National Pollution Discharge Elimination System (NPDES) Wastewater Treatment Plant Outfall Points, Region 9, 2011, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES outfalls/dischargers for waste water treatment plants which generally represent the site of the discharge....

  7. Equilibrium plasma corona surfaces

    International Nuclear Information System (INIS)

    Ensley, D.L.

    1979-07-01

    The distribution of charge of one sign when the opposite charge density is given is determined. Poisson's equation is solved in plane geometry for a simple specified ion density. This automatically gives the inverse solution for a given electron density, by reversing the sign of the potential. Some solutions can approximate a microwave confined corona, for very over dense cases

  8. Treatment of mixed wastes by thermal plasma discharges

    International Nuclear Information System (INIS)

    Diaz A, L.V.

    2007-01-01

    The present study has as purpose to apply the technology of thermal plasma in the destruction of certain type of waste generated in the ININ. As first instance, origin, classification and disposition of the radioactive waste generated in the ININ is identified. Once identified the waste, the waste to treat is determined based on: the easiness of treating him with plasma, classification and importance. Later on, a substance or compound settles down (sample model) that serves as indicative of the waste for its physical-chemical characteristics, this is made because in the Thermal Plasma Applications Laboratory is not had the license to work with radioactive material. The sample model and the material to form the vitreous matrix are characterized before and after the treatment in order to evaluating their degradation and vitrification. During the treatment by means of the thermal plasma, the appropriate conditions are determined for the degradation and vitrification of the waste. Also, it is carried out an energy balance in the system to know the capacity to fuse the material depending the transfer of existent heat between the plasma and the material to treat. Obtaining favorable results, it thought about to climb in the project and by this way to help to solve one of the environmental problems in Mexico, as they are it the mixed wastes. (Author)

  9. Loeb's and streamer-based mechanism for negative corona current pulses

    International Nuclear Information System (INIS)

    Vagnerova, L.; Skalny, J.D.; Cermak, M.

    1998-01-01

    The negative point-to-plane corona discharge in electronegative gaseous mixtures is studied experimentally and the basic mechanisms controlling the corona phenomena are discussed. The typical shapes of the current pulse waveforms observed in experiments with the nitrogen-freon mixtures are explained in terms of the theory by Loeb and of the positive-streamer-based model. (J.U.)

  10. Elimination of liquid discharge to the environment from the TA-50 Radioactive Liquid Waste Treatment Facility

    International Nuclear Information System (INIS)

    Moss, D.; Williams, N.; Hall, D.; Hargis, K.; Saladen, M.; Sanders, M.; Voit, S.; Worland, P.; Yarbro, S.

    1998-06-01

    Alternatives were evaluated for management of treated radioactive liquid waste from the radioactive liquid waste treatment facility (RLWTF) at Los Alamos National Laboratory. The alternatives included continued discharge into Mortandad Canyon, diversion to the sanitary wastewater treatment facility and discharge of its effluent to Sandia Canyon or Canada del Buey, and zero liquid discharge. Implementation of a zero liquid discharge system is recommended in addition to two phases of upgrades currently under way. Three additional phases of upgrades to the present radioactive liquid waste system are proposed to accomplish zero liquid discharge. The first phase involves minimization of liquid waste generation, along with improved characterization and monitoring of the remaining liquid waste. The second phase removes dissolved salts from the reverse osmosis concentrate stream to yield a higher effluent quality. In the final phase, the high-quality effluent is reused for industrial purposes within the Laboratory or evaporated. Completion of these three phases will result in zero discharge of treated radioactive liquid wastewater from the RLWTF

  11. Elimination of liquid discharge to the environment from the TA-50 Radioactive Liquid Waste Treatment Facility

    Energy Technology Data Exchange (ETDEWEB)

    Moss, D.; Williams, N.; Hall, D.; Hargis, K.; Saladen, M.; Sanders, M.; Voit, S.; Worland, P.; Yarbro, S.

    1998-06-01

    Alternatives were evaluated for management of treated radioactive liquid waste from the radioactive liquid waste treatment facility (RLWTF) at Los Alamos National Laboratory. The alternatives included continued discharge into Mortandad Canyon, diversion to the sanitary wastewater treatment facility and discharge of its effluent to Sandia Canyon or Canada del Buey, and zero liquid discharge. Implementation of a zero liquid discharge system is recommended in addition to two phases of upgrades currently under way. Three additional phases of upgrades to the present radioactive liquid waste system are proposed to accomplish zero liquid discharge. The first phase involves minimization of liquid waste generation, along with improved characterization and monitoring of the remaining liquid waste. The second phase removes dissolved salts from the reverse osmosis concentrate stream to yield a higher effluent quality. In the final phase, the high-quality effluent is reused for industrial purposes within the Laboratory or evaporated. Completion of these three phases will result in zero discharge of treated radioactive liquid wastewater from the RLWTF.

  12. Inception behaviour of pulsed positive corona in several gases

    International Nuclear Information System (INIS)

    Veldhuizen, E M van; Rutgers, W R

    2003-01-01

    The inception probability and the streamer length of pulsed positive corona discharges is determined in argon, nitrogen, oxygen and air. This study is performed in a 25 mm point-plane gap at a pressure of 1 bar. The lowest voltage at which a discharge in argon starts is 3 kV but only with an inception probability of 1%. At 5 kV the corona discharge in argon transforms into a spark with a probability close to 100%. The inception probability of corona discharges in all molecular gases used here as a function of the voltage is identical, starting with 1% at 4 kV and going up to 100% at 9 kV. The streamer lengths are quite different for these gases, nitrogen requiring the lowest voltage for streamers to cross the gap and oxygen the highest. This is probably due to electron attachment in oxygen. A remarkable result is that in air streamers bridge the gap at 8 kV, but spark breakdown occurs only above 26 kV. This property makes it relatively easy to obtain powerful pulsed corona discharges in air

  13. Inception behaviour of pulsed positive corona in several gases

    Energy Technology Data Exchange (ETDEWEB)

    Veldhuizen, E M van; Rutgers, W R [Technische Universiteit Eindhoven, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2003-11-07

    The inception probability and the streamer length of pulsed positive corona discharges is determined in argon, nitrogen, oxygen and air. This study is performed in a 25 mm point-plane gap at a pressure of 1 bar. The lowest voltage at which a discharge in argon starts is 3 kV but only with an inception probability of 1%. At 5 kV the corona discharge in argon transforms into a spark with a probability close to 100%. The inception probability of corona discharges in all molecular gases used here as a function of the voltage is identical, starting with 1% at 4 kV and going up to 100% at 9 kV. The streamer lengths are quite different for these gases, nitrogen requiring the lowest voltage for streamers to cross the gap and oxygen the highest. This is probably due to electron attachment in oxygen. A remarkable result is that in air streamers bridge the gap at 8 kV, but spark breakdown occurs only above 26 kV. This property makes it relatively easy to obtain powerful pulsed corona discharges in air.

  14. Predictors of Discharge to Home after Thrombolytic Treatment in Right Hemisphere Infarct Patients

    Directory of Open Access Journals (Sweden)

    E-I. Ruuskanen

    2010-01-01

    Full Text Available Background The aim of the study was to assess the association between thrombolysis and length of hospital stay after right hemisphere (RH infarct, and to identify which cognitive functions were predictive of discharge. Methods The study group consisted of 75 acute RH patients. Thirty-three patients had thrombolysis. Neuropsychologicalexaminations were performed within 11 days of stroke onset. The cognitive predictors were visual neglect, visual memory, visual search and reasoning and visuoconstructive abilities. The outcome variable was time from stroke to discharge to home. Results Thrombolysis emerged as a statistically significant predictor of discharge time in patients with moderate/severe stroke (NIHSS ≥5. In the total series of patients and in patients with mild stroke (NIHSS <5, thrombolysiswas not significantly associated with discharge time. Milder visuoconstructive defects shortened the hospital stay of the whole patient group and of patients with moderate/severe stroke. In all patient groups, independence in activitiesof daily living (ADL was a significant single predictor of a shorter hospital stay. The best combination of predictors for discharge was independence in ADL in the total series of patients and in patients with mild stroke, and thrombolysis and independence in ADL in patients with moderate/severe stroke. Conclusions Thrombolytic treatment was a significant predictor of earlier discharge to home in patients with moderate/severe RH infarct, while cognitive functions had less predictive power.

  15. Treatment of methyl orange by nitrogen non-thermal plasma in a corona reactor: The role of reactive nitrogen species

    Energy Technology Data Exchange (ETDEWEB)

    Cadorin, Bruno Mena, E-mail: brunomenacadorin@gmail.com [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Tralli, Vitor Douglas [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Ceriani, Elisa [Department of Chemical Sciences, Università di Padova (Italy); Benetoli, Luís Otávio de Brito [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Marotta, Ester, E-mail: ester.marotta@unipd.it [Department of Chemical Sciences, Università di Padova (Italy); Ceretta, Claudio [Department of Industrial Engineering, Università di Padova (Italy); Debacher, Nito Angelo [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Paradisi, Cristina [Department of Chemical Sciences, Università di Padova (Italy)

    2015-12-30

    Highlights: • Nitration of methyl orange is one of the main processes in treatment with N{sub 2}-plasma. • MS/MS analysis shows preferred nitration of methyl orange in ortho position. • N{sub 2} plasma, N{sub 2}-PAW, reaction with NO{sub 2}{sup −} or NO{sub 2}{sup −}/H{sub 2}O{sub 2} at pH 2 give the same products. - Abstract: Methyl orange (MO) azo dye served as model organic pollutant to investigate the role of reactive nitrogen species (RNS) in non-thermal plasma (NTP) induced water treatments. The results of experiments in which MO aqueous solutions were directly exposed to N{sub 2}-NTP are compared with those of control experiments in which MO was allowed to react with nitrite, nitrate and hydrogen peroxide, which are species formed in water exposed to N{sub 2}-NTP. Treatment of MO was also performed in PAW, Plasma Activated Water, that is water previously exposed to N{sub 2}-NTP. Both direct N{sub 2}-NTP and N{sub 2}-PAW treatments induced the rapid decay of MO. No appreciable reaction was instead observed when MO was treated with NO{sub 3}{sup −} and H{sub 2}O{sub 2} either under acidic or neutral pH. In contrast, in acidic solutions MO decayed rapidly when treated with NO{sub 2}{sup −} and with a combination of NO{sub 2}{sup −} and H{sub 2}O{sub 2}. Thorough product analysis was carried out by HPLC coupled with UV–vis and ESI–MS/MS detectors. In all experiments in which MO reaction was observed, the major primary product was a derivative nitro-substituted at the ortho position with respect to the N,N-dimethylamino group of MO. The reactions of RNS are discussed and a mechanism for the observed nitration products is proposed.

  16. A national discharge load of perfluoroalkyl acids derived from industrial wastewater treatment plants in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hee-Young; Seok, Hyun-Woo [Department of Civil and Environmental Engineering, Pusan National University, Busan 46241 (Korea, Republic of); Kwon, Hye-Ok; Choi, Sung-Deuk [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919 (Korea, Republic of); Seok, Kwang-Seol [Chemical Research Division, National Institute of Environmental Research, Incheon 22689 (Korea, Republic of); Oh, Jeong Eun [Department of Civil and Environmental Engineering, Pusan National University, Busan 46241 (Korea, Republic of)

    2016-09-01

    Levels of 11 perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), were measured in wastewater (influent and effluent) and sludge samples collected from 25 industrial wastewater treatment plants (I-WWTPs) in five industrial sectors (chemicals, electronics, metals, paper, and textiles) in South Korea. The highest ∑{sub 11}PFAAs concentrations were detected in the influent and effluent from the paper (median: 411 ng/L) and textile (median: 106 ng/L) industries, and PFOA and PFOS were the predominant PFAAs (49–66%) in wastewater. Exceptionally high levels of PFAAs were detected in the sludge associated with the electronics (median: 91.0 ng/g) and chemical (median: 81.5 ng/g) industries with PFOS being the predominant PFAA. The discharge loads of 11 PFAAs from I-WWTP were calculated that total discharge loads for the five industries were 0.146 ton/yr. The textile industry had the highest discharge load with 0.055 ton/yr (PFOA: 0.039 ton/yr, PFOS: 0.010 ton/yr). Municipal wastewater contributed more to the overall discharge of PFAAs (0.489 ton/yr) due to the very small industrial wastewater discharge compared to municipal wastewater discharge, but the contribution of PFAAs from I-WWTPs cannot be ignored. - Highlights: • 11 PFAAs in wastewater and sludge from 5 industrial sectors were investigated. • PFOA and PFOS were the dominant in wastewater while PFOS was predominant in sludge. • The total discharge loads from 5 industrial sectors 0.146 ton/yr. • The textile industry showed the highest discharge load with 0.055 ton/yr.

  17. National Pollution Discharge Elimination System (NPDES) Wastewater Treatment Plant Points, Region 9, 2007, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES Waste Water Treatment Plant Facilities. NPDES (National Pollution Discharge Elimination System) is an EPA...

  18. National Pollution Discharge Elimination System (NPDES) Wastewater Treatment Plant Points, Region 9, 2011, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES Waste Water Treatment Plant Facilities. NPDES (National Pollution Discharge Elimination System) is an EPA...

  19. National Pollution Discharge Elimination System (NPDES) Wastewater Treatment Plant Points, Region 9, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES Waste Water Treatment Plant Facilities. NPDES (National Pollution Discharge Elimination System) is an EPA...

  20. Adhesion improvement of glass-fibre-reinforced polyester composites by gliding arc discharge treatment

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Sørensen, Bent F.; Løgstrup Andersen, Tom

    2013-01-01

    A gliding arc is a plasma that can be operated at atmospheric pressure and applied for plasma surface treatment for adhesion improvement. In the present work, glass-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding arc discharge with an air flow to improve...

  1. Surface treatment of polyethylene terephthalate film using atmospheric pressure glow discharge in air

    International Nuclear Information System (INIS)

    Fang Zhi; Qiu Yuchang; Wang Hui

    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 degree, respectively. (authors)

  2. Electro-discharge mashining of natural single-phase adsorbent for sewage treatment

    International Nuclear Information System (INIS)

    Gashimov, A.M.; Gurbanov, K.B.; Zakieva, I.G.; Gasanov, M.A.; Ganbarov, D.M.

    2012-01-01

    Full text : The results of research of wastewater treatment plants with soap-electric effect have been presented. It has been shown that using other electric discharge effect of barrier type has led to the significant increasing adsorption refining efficiency of wastewater

  3. Corona SDK application design

    CERN Document Server

    Williams, Daniel

    2013-01-01

    A step by step tutorial that focuses on everything from setup to deployment of basic apps.Have you ever wanted to create your own app? Then this book is for you. You will learn how to create apps using Corona SDK and how to publish your app so others can get a glimpse of your creation. This book is aimed at both Android and iOS app developers. The reader must have basic knowledge of app development.

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

    International Nuclear Information System (INIS)

    Mingolo, N.; Gonzalez, C.R.; Martinez, O.E.; Rocca, J.J.

    1997-01-01

    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 μA was found to limit the shot to shot current variation to within 1.5%. 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 1997 American Institute of Physics

  5. 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.}

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

    International Nuclear Information System (INIS)

    Batt, Angela L.; Bruce, Ian B.; Aga, Diana S.

    2006-01-01

    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 μg/L. Caffeine was detected in all effluents at concentrations ranging from 0.19 to 9.9 μg/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 μg/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

  7. Determining a sustainable and economically optimal wastewater treatment and discharge strategy.

    Science.gov (United States)

    Hardisty, Paul E; Sivapalan, Mayuran; Humphries, Robert

    2013-01-15

    Options for treatment and discharge of wastewater in regional Western Australia (WA) are examined from the perspective of overall sustainability and social net benefit. Current practice in the state has typically involved a basic standard of treatment deemed to be protective of human health, followed by discharge to surface water bodies. Community and regulatory pressure to move to higher standards of treatment is based on the presumption that a higher standard of treatment is more protective of the environment and society, and thus is more sustainable. This analysis tests that hypothesis for Western Australian conditions. The merits of various wastewater treatment and discharge strategies are examined by quantifying financial costs (capital and operations), and by monetising the wider environmental and social costs and benefits of each option over an expanded planning horizon (30 years). Six technical treatment-disposal options were assessed at a test site, all of which met the fundamental criterion of protecting human health. From a financial perspective, the current business-as-usual option is preferred - it is the least cost solution. However, valuing externalities such as water, greenhouse gases, ecological impacts and community amenity, the status quo is revealed as sub-optimal. Advanced secondary treatment with stream disposal improves water quality and provides overall net benefit to society. All of the other options were net present value (NPV) negative. Sensitivity analysis shows that the favoured option outperforms all of the others under a wide range of financial and externality values and assumptions. Expanding the findings across the state reveals that moving from the identified socially optimal level of treatment to higher (tertiary) levels of treatment would result in a net loss to society equivalent to several hundred million dollars. In other words, everyone benefits from improving treatment to the optimum point. But society, the environment, and

  8. Degradation of methylparaben in water by corona plasma coupled with ozonation.

    Science.gov (United States)

    Dobrin, D; Magureanu, M; Bradu, C; Mandache, N B; Ionita, P; Parvulescu, V I

    2014-11-01

    The degradation of methylparaben (MeP) in water was investigated using a pulsed corona discharge generated in oxygen, above the liquid. A comparison was made between results obtained in semi-batch corona (SBC) configuration (stationary solution, continuous gas flow) and results obtained in a semi-batch corona with recirculation combined with ozonation (SBCR + O3), where the liquid is continuously circulated between a solution reservoir and the plasma reactor and the effluent gas containing ozone is bubbled through the solution in the reservoir. It was found that MeP was completely degraded after 10-15 min of treatment in both configurations. Oxidation by ozone alone, in the absence of plasma, was a slower process. The energy efficiency for MeP removal (Y MeP) and for mineralization (Y TOC) was significantly higher in the SBCR + O3 configuration (Y MeP = 7.1 g/kWh at 90 % MeP removal and Y TOC = 0.41 g/kWh at 50 % total organic carbon (TOC) removal) than in the SBC configuration (Y MeP = 0.6 g/kWh at 90 % MeP removal and Y TOC = 0.11 g/kWh at 50 % TOC removal).

  9. Zero-discharge wastewater treatment facility for a 900-MWe GCC power plant

    International Nuclear Information System (INIS)

    Rosain, R.M.; Dalan, J.A.

    1992-05-01

    Florida Power and Light desires to examine the prospect of achieving zero liquid discharge from the gasification area of their proposed 900-MW coal gasification-combined cycle (GCC) power plant expansion at the Martin station. This report provides information about the technologies available, cost, and process selection methods, and recommends a preferred system for achieving zero liquid discharge from the gasification block. The recommended system consists of primary clarification and vapor compression evaporation, followed by carbon adsorption post-treatment of the evaporator distillate. Dry solids are produced from the evaporator concentrate with a crystallizer/centrifuge combination. The system recovers 99 percent of the wastewater as pure distillate vater. The predicted capital cost for the 265-gpm system is $12.5 million; the predicted operating costs are $18.60/1000 gallons. Both costs are in 1990 dollars. Promising treatment technologies to examine for future designs are cooling tower treatment and freeze crystallization

  10. Angina - discharge

    Science.gov (United States)

    Chest pain - discharge; Stable angina - discharge; Chronic angina - discharge; Variant angina - discharge; Angina pectoris - discharge; Accelerating angina - discharge; New-onset angina - discharge; Angina-unstable - discharge; ...

  11. Galactic absorption line coronae

    International Nuclear Information System (INIS)

    Bregman, J.N.

    1981-01-01

    We have investigated whether gaseous coronae around galaxies rise to the absorption systems seen in quasar spectra. In our model, gas originally located in the disk is heated to the million degree range and rises to surround the galaxy; the gas remains bound to the galaxy. Optically thin radiative cooling drives a thermal instability in the hot gas which causes cool clouds (T 4 K) to condense out of the corona. These clouds, which follow ballistic trajectories back to the disk, are the absorption sites. A two-dimensional hydrodynamic code with radiative cooling was used to study the dynamics and thermodynamics of the corona as well as the position rate at which clouds form. Coupled to the code is a galaxy with two mass components, a disk (approx.10 11 M/sub sun/) and a dark halo (approx.10 12 M/sub sun/). In a model where the temperature at the base of the corona (in the disk) is 3 x 10 6 K, absorbing gas of column density NL> or approx. =10 18 cm 2 extends radially to 100 kpc (face-on orientation) and vertically to 60 Kpc (edge-on orientation). The total mass of gas required here (coronal plus cloud gas) is 1.4 x 10 10 M/sub sun/, while the minimum supernova heating rate is one supernova per 27 years. In two other models (base coronal temperatures of 0.50 x 10 6 K and 1 x 10 6 K), coronal gas rises from an extended gaseous disk (in the previous model, the gas comes from a typical gaseous disk approximately 15 kpc in extent). Here, column densities of 10 19 cm -2 out to a radius of 70 kpc (face-on orientation) are achieved with a total gas mass of 1.7 x 10 9 M/sub direct-product/ and 2.0 x 10 9 M/sub sun/ and minimum heating rates of approximately one supernova per 170 years and one supernova per 60 years

  12. Regulating specific organic substances and heavy metals in industrial wastewater discharged to municipal wastewater treatment plants

    DEFF Research Database (Denmark)

    Grüttner, Henrik; Munk, L.; Pedersen, F.

    1994-01-01

    Due to the extension of wastewater treatment plants to nutrient removal and the development towards reuse of sludge m agriculture, new guidelines for regulating industrial discharges m Denmark were needed. The paper describes how a concept for regulating the discharge of specific organic substances...... substances, present knowledge of fate and effects in biological treatment plants is too scarce to underpin the setting of general standards. Therefore, it has been decided to base the developed priority system on the data used in the EEC-system for classification of hazardous chemicals. This includes ready...... degradability, defined by the OECD-test, bio-sorption and bio-accumulation, defined by the octanol/water distribution coefficient and toxic effects on water organisms. Several potential effects of seven heavy metals have been evaluated, and the most critical effects were found to be the quality criteria...

  13. Reel-to-Reel Atmospheric Pressure Dielectric Barrier Discharge (DBD Plasma Treatment of Polypropylene Films

    Directory of Open Access Journals (Sweden)

    Lukas JW Seidelmann

    2017-03-01

    Full Text Available Atmospheric pressure plasma treatment of the surface of a polypropylene film can significantly increase its surface energy and, thereby improve the printability of the film. A laboratory-scale dielectric barrier discharge (DBD system has therefore been developed, which simulates the electrode configuration and reel-to-reel web transport mechanism used in a typical industrial-scale system. By treating the polypropylene in a nitrogen discharge, we have shown that the water contact angle could be reduced by as much as 40° compared to the untreated film, corresponding to an increase in surface energy of 14 mNm−1. Ink pull-off tests showed that the DBD plasma treatment resulted in excellent adhesion of solvent-based inks to the polypropylene film.

  14. Viking solar corona experiment

    International Nuclear Information System (INIS)

    Tyler, G.L.; Brenkle, J.P.; Komarek, T.A.; Zygielbaum, A.I.

    1977-01-01

    The 1976 Mars solar conjunction resulted in complete occulations of the Viking spacecraft by the sun at solar minimum. During the conjunction period, coherent 3.5- and 13-cm wavelength radio waves from the orbiters passed through the solar corona and were received with the 64-m antennas of the NASA Deep Space Network. Data were obtained within at least 0.3 and 0.8 R/sub s/ of the photosphere at the 3.5- and 13-cm wavelengths, respectively. The data can be used to determine the plasma density integrated along the radio path, the velocity of density irregularities in the coronal plasma, and the spectrum of the density fluctuations in the plasma. Observations of integrated plasma density near the south pole of the sun generally agree with a model of the corona which has an 8:1 decrease in plasma density from the equator to the pole. Power spectra of the 3.5- and 13-cm signals at a heliocentric radial distance of about 2 R/sub s/ have a 1/2-power width of several hundred hertz and vary sharply with proximate geometric miss distance. Spectral broadening indicates a marked progressive increase in plasma irregularities with decreasing ray altitude at scales between about 1 and 100 km

  15. Plasma surface treatment of Cu by nanosecond-pulse diffuse discharges in atmospheric air

    Science.gov (United States)

    Cheng, ZHANG; Jintao, QIU; Fei, KONG; Xingmin, HOU; Zhi, FANG; Yu, YIN; Tao, SHAO

    2018-01-01

    Nanosecond-pulse diffuse discharges could provide high-density plasma and high-energy electrons at atmospheric pressure. In this paper, the surface treatment of Cu by nanosecond-pulse diffuse discharges is conducted in atmospheric air. Factors influencing the water contact angle (WCA), chemical composition and microhardness, such as the gap spacing and treatment time, are investigated. The results show that after the plasma surface treatment, the WCA considerably decreases from 87° to 42.3°, and the surface energy increases from 20.46 mJ m-2 to 66.28 mJ m-2. Results of energy dispersive x-ray analysis show that the concentration of carbon decreases, but the concentrations of oxygen and nitrogen increase significantly. Moreover, the microhardness increases by approximately 30% after the plasma treatment. The aforementioned changes on the Cu surface indicate the plasma surface treatment enhances the hydrophilicity and microhardness, and it cleans the carbon and achieves oxidization on the Cu surface. Furthermore, by increasing the gap spacing and treatment time, better treatment effects can be obtained. The microhardness in the case of a 2.5 cm gap is higher than that in the case of a 3 cm gap. More oxygen and nitrogen species appear on the Cu surface for the 2.5 cm gap treatment than for the 3 cm gap treatment. The WCA significantly decreases with the treatment time when it is no longer than 90 s, and then it reaches saturation. In addition, more oxygen-containing and nitrogen-containing groups appear after extended plasma treatment time. They contribute to the improvement of the hydrophilicity and oxidation on the Cu surface.

  16. Characteristics and Biodegradability of Wastewater Organic Matter in Municipal Wastewater Treatment Plants Collecting Domestic Wastewater and Industrial Discharge

    OpenAIRE

    Yun-Young Choi; Seung-Ryong Baek; Jae-In Kim; Jeong-Woo Choi; Jin Hur; Tae-U Lee; Cheol-Joon Park; Byung Joon Lee

    2017-01-01

    Municipal wastewater treatment plants (WWTPs) in Korea collect and treat not only domestic wastewater, but also discharge from industrial complexes. However, some industrial discharges contain a large amount of non-biodegradable organic matter, which cannot be treated properly in a conventional biological WWTP. This study aimed to investigate the characteristics and biodegradability of the wastewater organic matter contained in the industrial discharges and to examine the fate of the industri...

  17. Treatment of Dye Wastewater by Using a Hybrid Gas/Liquid Pulsed Discharge Plasma Reactor

    International Nuclear Information System (INIS)

    Lu Na; Li Jie; Wu Yan; Masayuki, Sato

    2012-01-01

    A hybrid gas/liquid pulsed discharge plasma reactor using a porous ceramic tube is proposed for dye wastewater treatment. High voltage pulsed discharge plasma was generated in the gas phase and simultaneously the plasma channel was permeated through the tiny holes of the ceramic tube into the water phase accompanied by gas bubbles. The porous ceramic tube not only separated the gas phase and liquid phase but also offered an effective plasma spreading channel. The effects of the peak pulse voltage, additive gas varieties, gas bubbling rate, solution conductivity and TiO 2 addition were investigated. The results showed that this reactor was effective for dye wastewater treatment. The decoloration efficiency of Acid Orange II was enhanced with an increase in the power supplied. Under the studied conditions, 97% of Acid Orange II in aqueous solution was effectively decolored with additive oxygen gas, which was 51% higher than that with argon gas, and the increasing O 2 bubbling rate also benefited the decoloration of dye wastewater. Water conductivity had a small effect on the level of decoloration. Catalysis of TiO 2 could be induced by the pulsed discharge plasma and addition of TiO 2 aided the decoloration of Acid Orange II.

  18. New progress in wastewater treatment technology for standard-reaching discharge in sour gas fields

    Directory of Open Access Journals (Sweden)

    Jie Yang

    2018-02-01

    Full Text Available Gas field water is generally characterized by complex contaminant components and high salinity. Its proper treatment has always been the great concern in the field of environmental protection of oil & gas fields. In this paper, the wastewater from a gas field in the Sichuan Basin with high salinity and more contaminants (e.g. sulfides was treated as a case study for the standard-reaching discharge. Lab experiments were carried out to analyze the adaptability and effectiveness of coagulation–desulfurization composite treatment technology, chemical oxidation based ammonia nitrogen removal technology and cryogenic multi-efficacy distillation technology in the treatment of wastewater in this field. The results show that the removal rate of sulfides and oils is over 90% if polymeric ferric sulfate (PFS is taken as the coagulant combined with TS-1 desulfurization agent. Besides, the removal rate of ammonia nitrogen is over 96% if CA-1 is taken as the oxidant. Finally, after the gas field water is treated by means of cryogenic three-efficacy distillation technology, chloride concentration of distilled water is below 150 mg/L and CODcr concentration is less than 60 mg/L. It is concluded that after the whole process treatment, the main contaminant indicators of wastewater in this case study can satisfy the grade one standard specified in the Integrated Wastewater Discharge Standard (GB 8978–1996 and the chloride concentration can meet the requirement of the Standards for Irrigation Water Quality (GB 5084–2005. To sum up, the above mentioned composite technologies are efficient to the wastewater treatment in sour gas fields. Keywords: Sulfide-bearing gas field water, Coagulation, Desulfurization, Chemical oxidation, Standard discharge, Ammonia nitrogen, Chloride, Cryogenic multi-efficacy distillation, Sichuan Basin

  19. NO removal characteristics of a corona radical shower system under DC and AC/DC superimposed operations

    NARCIS (Netherlands)

    Yan, K.; Yamamoto, T.; Kanazawa, S.; Ohkubo, T.; Nomoto, Y.; Chang, Jen-Shih

    2001-01-01

    In this paper, the effects of the applied voltage modes on the positive corona discharge morphology and NO removal characteristics from air streams are experimentally investigated. By using a DC superimposed high frequency AC power supply (10-60 kHz), a uniform streamer corona can be generated,

  20. Short communication: Evaluation of vaginal discharge following treatment with a progesterone insert.

    Science.gov (United States)

    Fischer-Tenhagen, C; von Krueger, X; Heuwieser, W

    2012-08-01

    Yellowish discharge after application of intravaginal progesterone releasing inserts is frequently observed in cows. The objective of this study was to compare the bacteriological contamination of the vagina and uterus before and after a treatment with a progesterone insert in heifers. Forty-two Holstein heifers received a progesterone releasing insert [Eazi-Breed controlled internal drug release (CIDR) insert; Pfizer Animal Health, Berlin, Germany] for 7d. The protruding tail had been removed from half of the inserts (no tail group: n=21; tail group: n=21). Nine heifers from the tail group lost the insert within the 7-d treatment interval and were excluded. Heifers identified in estrus were artificially inseminated on d 9 or 10. Vaginal discharge was scored on a 4-point scale [vaginal discharge score (VDS) 0 to 3] and vaginal swabs were taken for bacteriological examination on d 0 and 7 and the day of artificial insemination (AI). Furthermore, cytological and bacteriological samples were obtained from the uterus on d 7 and the day of AI. On d 0, coliforms and Streptococcus spp. were found in vaginal swabs of 21 heifers (64%). On d 7, all heifers showed purulent vaginal discharge (VDS 2 to 3). The VDS was higher in the tail group compared with the no tail group. Arcanobacterium pyogenes, coliforms, and Streptococcus spp. were isolated from the vaginal swabs in 32 of 33 (96%) heifers on d 7. On the day of AI, VDS had improved to 0 or 1 in 96% of the heifers. However, A. pyogenes, coliforms, and Streptococcus spp. were still isolated in 17 of 33 (53%) heifers from the vagina and in 32 of 33 (96%) heifers from the endometrium. Endometrial cytology revealed polymorphonuclear neutrophils (PMN) in 11 heifers (6 to 32% PMN). Five samples exceeded the threshold of 5% PMN, and 2 samples exceeded the 10% PMN threshold, indicative of subclinical endometritis. In conclusion, pyogenic bacteria were found in the vagina and uterus on d 7 and the day of AI after intravaginal

  1. Regulation, characterization and treatment of discharge waters from pipelines. Volume 1. Topical report, January 1989-April 1992. Executive summary

    International Nuclear Information System (INIS)

    Tallon, J.T.; Fillo, J.P.

    1992-04-01

    The report examines environmental issues related to hydrostatic testing of discharge waters generated from integrity testing of natural gas pipelines. Hydrostatic testing, and proper environmental management of the discharge waters, can be required by DOT regulations. However, disposal of water used to conduct a hydrostatic pipeline test is regulated on a state-by-state basis. State-specific requirements vary widely, ranging from an authorization letter to a complete NPDES permit. Monitoring may be required before and during discharge, include a variety of analyses, have varying protocols for obtaining samples, and may be required either to obtain data or to ascertain compliance with stipulated discharge limits. The composition of the discharge and state-specific discharge limitations dictate treatment needs on a case-by-case basis. The volume consists of the Executive Summary of a five-volume report series

  2. Note: A phase synchronization photography method for AC discharge

    Science.gov (United States)

    Wu, Zhicheng; Zhang, Qiaogen; Ma, Jingtan; Pang, Lei

    2018-05-01

    To research discharge physics under AC voltage, a phase synchronization photography method is presented. By using a permanent-magnet synchronous motor to drive a photography mask synchronized with a discharge power supply, discharge images in a specific phase window can be recorded. Some examples of discharges photographed by this method, including the corona discharge in SF6 and the corona discharge along the air/epoxy surface, demonstrate the feasibility of this method. Therefore, this method provides an effective tool for discharge physics researchers.

  3. Influence of dielectric barrier discharge treatment on mechanical and dyeing properties of wool

    Science.gov (United States)

    Rahul, NAVIK; Sameera, SHAFI; Md Miskatul, ALAM; Md Amjad, FAROOQ; Lina, LIN; Yingjie, CAI

    2018-06-01

    Physical and chemical properties of wool surface significantly affect the absorbency, rate of dye bath exhaustion and fixation of the industrial dyes. Hence, surface modification is a necessary operation prior to coloration process in wool wet processing industries. Plasma treatment is an effective alternative for physiochemical modification of wool surface. However, optimum processing parameters to get the expected modification are still under investigation, hence this technology is still under development in the wool wet processing industries. Therefore, in this paper, treatment parameters with the help of simple dielectric barrier discharge plasma reactor and air as a plasma gas, which could be a promising combination for treatment of wool substrate at industrial scale were schematically studied, and their influence on the water absorbency, mechanical, and dyeing properties of twill woven wool fabric samples are reported. It is expected that the results will assist to the wool coloration industries to improve the dyeing processes.

  4. Impact of warfarin discharge education program on hospital readmission and treatment costs.

    Science.gov (United States)

    Brunetti, Luigi; Lee, Seung-Mi; Doherty, Nancy; Suh, David; Kim, Jeong-Eun; Lee, Sun-Hong; Choi, Yong Chan; Suh, Dong-Churl

    2018-03-31

    Background Although warfarin is highly effective, management of patients prescribed warfarin is complex due to its narrow therapeutic window. Objective To evaluate the impact of a formal warfarin discharge education program (WDEP) on hospital readmission and treatment costs in patients who received warfarin therapy. Setting Robert Wood Johnson University Hospital Somerset in Somerville, New Jersey, USA. Method In this interventional cohort study, patients were assigned to either the WDEP group or the usual care group. The effects of the WDEP on readmission within 90 days after discharge were analyzed using Cox proportional hazards models. Factors influencing treatment cost were identified using generalized linear model with log-link function and gamma distribution. Main outcome measure Hospital readmission within 90 days and treatment costs associated with hospital readmission. Results Among 692 eligible patients, 203 in each group were matched using propensity scores and there were no statistically significant differences in the patient baseline characteristics between two groups. The risk of all-cause readmission within 90 days was significantly lower in the WDEP group compared to the usual care group (relative risk = 0.46, 95% CI 0.28-0.76). The treatment costs associated with hospital readmission in the WDEP group were 19% lower than those in the usual care group after adjusting for the study variables. Conclusion A formal, individualized WDEP provided by pharmacists resulted in significant reduction of readmission and treatment costs. The economic burden of treatment costs associated with warfarin can be controlled if well-organized warfarin education is provided to patients who received warfarin therapy.

  5. Effectiveness of intrauterine treatment with cephapirin in dairy cows with purulent vaginal discharge.

    Science.gov (United States)

    Tison, N; Bouchard, E; DesCôteaux, L; Lefebvre, R C

    2017-02-01

    The objective of this study was to assess the efficacy of cephapirin intrauterine treatment preceding a timed artificial insemination protocol in lactating dairy cows with purulent vaginal discharges (PVDs). Holstein dairy cows (n = 1247) from 18 herds were enrolled in a controlled randomized clinical trial. At 34 days in milk (DIM; ±7 days), cows had a genital examination (transrectal palpation, vaginoscopy, and uterine bacteriology). They were randomly assigned to either the control group (CONT, no treatment) or the treatment group (CEPH) consisting of 1 intrauterine infusion of 500-mg cephapirin benzathine (RCL) (Metricure, Merck Animal Health, Montreal, Canada) regardless of the uterine health status. All cows were systematically enrolled in a presynch-ovsynch protocol for the first insemination. A second genital examination was made 2 weeks later. Cows that received any systemic or local antibiotics 10 days prior sampling to the end of the synchronization protocol were excluded from the study. Reproductive data of cows were collected for at least 300 DIM, entered in a databank, and validated (health record management software, DSAHR). Pregnancy diagnosis was done by transrectal palpation at the routinely scheduled veterinarian visits. On the basis of the highest sum of sensibility and specificity for pregnancy status at 120 DIM, the optimal cutoff for vaginal discharge score was determined as the presence of cloudy discharge with or without purulent material (PVD+, score 2). With a prevalence of 21.6% at 34 DIM, PVD+ was detrimental to the first-service conception rate (FSCR; PVD+: 26 ± 5%; PVD-: 40 ± 3%; P = 0.02). The negative effect of PVD+ was indicated by a hazard ratio of 0.72 (chi-square = 8.58; P < 0.01; 95% confidence interval = 0.56-0.91). Treatment with cephapirin was associated with a significant improvement of the FSCR in PVD+ cows (PVD+ CEPH: 36 ± 5%, PVD+ CONT: 23 ± 5%; P < 0.05), although it did not produce a

  6. Particulate and colloidal silver in sewage effluent and sludge discharged from British wastewater treatment plants.

    Science.gov (United States)

    Johnson, Andrew C; Jürgens, Monika D; Lawlor, Alan J; Cisowska, Iwona; Williams, Richard J

    2014-10-01

    Differential filtration was used to measure silver (>2 nm) entering and leaving nine sewage treatment plants (STPs). The mean concentration of colloidal (2-450 nm) silver, which includes nanosilver, was found to be 12 ng L(-1) in the influent and 6 ng L(-1) in the effluent. For particulate silver (>450 nm) the mean values were 3.3 μg L(-1) for influent and 0.08 μg L(-1) for effluent. Thus, removal was around 50% and 98% for colloidal and particulate silver respectively. There was no significant difference in performance between the different types of STP investigated (three examples each of activated sludge, biological filter and biological filter with tertiary treatment located across England, UK). In addition, treated sewage sludge samples (biosolids) were taken from several STPs to measure the total silver likely to be discharged to soils. Total silver was 3-14 mg kg(-1) DW in the sludge (median 3.6), which if the sludge were added at the recommended rate to soil, would add 11 μg kg(-1) yr(-1) to the top 20 cm soil layer. Predicted concentrations using the LF2000-WQX model for all the rivers of England and Wales for nanosilver were typically in the 0-1 ng L(-1) range but levels up to 4 ng L(-1) are possible in a high discharge and low flow scenario. Predicted concentrations for the total particulate forms were mostly below 50 ng L(-1) except for a high discharge and low flow scenario where concentrations could reach 135 ng L(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Fang Zhi; Qiu Yuchang; Wang Hui; Kuffel, E

    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 CH 3 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

  8. Treatment seeking, vaginal discharge and psychosocial distress among women in urban Mumbai.

    Science.gov (United States)

    Kostick, Kristin M; Schensul, Stephen L; Jadhav, Kalpita; Singh, Rajendra; Bavadekar, Amruta; Saggurti, Niranjan

    2010-09-01

    Vaginal discharge (safed pani in Hindi, meaning "white water") is one of the leading symptoms for which women in India seek care. Treatment-seeking for safed pani is disproportionately high among poor women, representing a physical, emotional and financial burden for low-income families. Safed pani is only rarely indicative of a reproductive tract or sexually transmitted infection. The discrepancy between symptom reports and observed pathology has led some researchers to characterize safed pani as a culturally based expression of more generalized negative life situation. Data are drawn from two prevention intervention studies (2002-2006 and 2007-2012) conducted in economically marginal communities in Mumbai. Results show that husbands as problem generators and spousal abusers and women's greater perceived empowerment and reported tension are significantly associated with safed pani. These results provide the basis for identifying women at greater risk for psychosocial distress and providing supports at the locations at which they seek treatment.

  9. Dielectric Barrier Discharge Plasma-Induced Photocatalysis and Ozonation for the Treatment of Wastewater

    International Nuclear Information System (INIS)

    Sun, Mok Young; Jin-Oh, Jo; Heon-Ju, Lee

    2008-01-01

    The physicochemical processes of dielectric barrier discharge (DBD) such as in-situ formation of chemically active species and emission of ultraviolet (UV)/visible light were utilized for the treatment of a simulated wastewater formed with Acid Red 4 as the model organic contaminant. The chemically active species (mostly ozone) produced in the DBD reactor were well distributed in the wastewater using a porous gas diffuser, thereby increasing the gas-liquid contact area. For the purpose of making the best use of the light emission, a titanium oxide-based photocatalyst was incorporated in the wastewater treating system. The experimental parameters chosen were the voltage applied to the DBD reactor, the initial pH of the wastewater, and the concentration of hydrogen peroxide added to the wastewater. The results have clearly shown that the present system capable of degrading organic contaminants in two ways (photocatalysis and ozonation) may be a promising wastewater treatment technology.

  10. Dielectric Barrier Discharge Plasma-Induced Photocatalysis and Ozonation for the Treatment of Wastewater

    Science.gov (United States)

    Mok, Young Sun; Jo, Jin-Oh; Lee, Heon-Ju

    2008-02-01

    The physicochemical processes of dielectric barrier discharge (DBD) such as in-situ formation of chemically active species and emission of ultraviolet (UV)/visible light were utilized for the treatment of a simulated wastewater formed with Acid Red 4 as the model organic contaminant. The chemically active species (mostly ozone) produced in the DBD reactor were well distributed in the wastewater using a porous gas diffuser, thereby increasing the gas-liquid contact area. For the purpose of making the best use of the light emission, a titanium oxide-based photocatalyst was incorporated in the wastewater treating system. The experimental parameters chosen were the voltage applied to the DBD reactor, the initial pH of the wastewater, and the concentration of hydrogen peroxide added to the wastewater. The results have clearly shown that the present system capable of degrading organic contaminants in two ways (photocatalysis and ozonation) may be a promising wastewater treatment technology.

  11. Effects of air dielectric barrier discharge plasma treatment time on surface properties of PBO fiber

    International Nuclear Information System (INIS)

    Wang Qian; Chen Ping; Jia Caixia; Chen, Mingxin; Li Bin

    2011-01-01

    In this paper, the effects of air dielectric barrier discharge (DBD) plasma treatment time on surface properties of poly(p-phenylene benzobisoxazole) (PBO) fiber were investigated. The surface characteristics of PBO fiber before and after the plasma treatments were analyzed by dynamic contact angle (DCA) analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). DCA measurements indicated that the surface wettability of PBO fiber was improved significantly by increasing the fiber surface free energy via air DBD plasma treatments. The results were confirmed by the improvement of adhesion of a kind of thermoplastic resin to PBO fiber which was observed by SEM, showing that more resin was adhering evenly to the fiber surface. AFM measurement revealed that the surface topography of PBO fiber became more complicated and the surface roughness was greatly enhanced after the plasma treatments, and XPS analysis showed that some new polar groups (e.g. -O-C=O) were introduced on plasma treated PBO fiber surface. The results of this study also showed that the surface properties of PBO fiber changed with the elongation of plasma treatment time.

  12. Predictors of premature discontinuation of outpatient treatment after discharge of patients with posttraumatic stress disorder

    Directory of Open Access Journals (Sweden)

    Wang HR

    2015-03-01

    Full Text Available Hee Ryung Wang, Young Sup Woo, Tae-Youn Jun, Won-Myong Bahk Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Korea Objective: This study aimed to examine the sociodemographic and disease-related variables associated with the premature discontinuation of psychiatric outpatient treatment after discharge among patients with noncombat-related posttraumatic stress disorder. Methods: We retrospectively reviewed the medical records of patients who were discharged with a diagnosis of posttraumatic stress disorder. Results: Fifty-five percent of subjects (57/104 prematurely discontinued outpatient treatment within 6 months of discharge. Comparing sociodemographic variables between the 6-month non-follow-up group and 6-month follow-up group, there were no variables that differed between the two groups. However, comparing disease-related variables, the 6-month follow-up group showed a longer hospitalization duration and higher Global Assessment of Function score at discharge. The logistic regression analysis showed that a shorter duration of hospitalization predicted premature discontinuation of outpatient treatment within 6 months of discharge. Conclusion: The duration of psychiatric hospitalization for posttraumatic stress disorder appeared to influence the premature discontinuation of outpatient treatment after discharge. Keywords: posttraumatic stress disorder, discontinuation, compliance, predictor

  13. Prostate brachytherapy - discharge

    Science.gov (United States)

    Implant therapy - prostate cancer - discharge; Radioactive seed placement - discharge ... You had a procedure called brachytherapy to treat prostate cancer. Your treatment lasted 30 minutes or more, ...

  14. Two-year survey of specific hospital wastewater treatment and its impact on pharmaceutical discharges.

    Science.gov (United States)

    Wiest, Laure; Chonova, Teofana; Bergé, Alexandre; Baudot, Robert; Bessueille-Barbier, Frédérique; Ayouni-Derouiche, Linda; Vulliet, Emmanuelle

    2018-04-01

    domestic discharges. Thanks to the SIPIBEL site, data obtained from this 2-year program are useful to evaluate the relevance of separate hospital wastewater treatment.

  15. Enhancement of discharge performance of Li/CF x cell by thermal treatment of CF x cathode material

    Science.gov (United States)

    Zhang, Sheng S.; Foster, Donald; Read, Jeffrey

    In this work we demonstrate that the thermal treatment of CF x cathode material just below the decomposition temperature can enhance discharge performance of Li/CF x cells. The performance enhancement becomes more effective when heating a mixture of CF x and citric acid (CA) since CA serves as an extra carbon source. Discharge experiments show that the thermal treatment not only reduces initial voltage delay, but also raises discharge voltage. Whereas the measurement of powder impedance indicates the thermal treatment does not increase electronic conductivity of CF x material. Based on these facts, we propose that the thermal treatment results in a limited decomposition of CF x, which yields a subfluorinated carbon (CF x- δ), instead of a highly conductive carbon. In the case of CF x/AC mixture, the AC provides extra carbon that reacts with F 2 and fluorocarbon radicals generated by the thermal decomposition of CF x to form subfluorinated carbon. The process of thermal treatment is studied by thermogravimetric analysis and X-ray diffraction, and the effect of treatment conditions such as heating temperature, heating time and CF x/CA ratio on the discharge performance of CF x cathode is discussed. As an example, a Li/CF x cell using CF x treated with CA at 500 °C under nitrogen for 2 h achieved theretical specific capacity when being discharged at C/5. Impedance analysis indicates that the enhanced performance is attributed to a significant reduction in the cell reaction resistance.

  16. Adsorbability Enhancement of Macroporous Resin by Dielectric Barrier Discharge Plasma Treatment to Phenol in Water

    Directory of Open Access Journals (Sweden)

    Shoufeng Tang

    2016-01-01

    Full Text Available In order to enhance the adsorption efficiency and economize the use of macroporous resin, we have treated it with the dielectric barrier discharge (DBD plasma to improve its adsorbing capacity for phenol. The effects of operation conditions, for instance, applied voltage, treated time, and air flow rate on resin, were investigated by adsorption kinetics and isotherms. Results showed that the adsorption data were in good agreement with the pseudo-second-order and Freundlich equation. Experimental results showed that the modified resin was 156.5 mg/g and 39.2% higher than the untreated sample, when the modified conditions were conducted for discharge voltage 20 kV, treatment time 45 min, and air flow rate 1.2 L/min. The resin was characterized by FTIR and nitrogen adsorption isotherms before and after the DBD processes. It was found that the reason for the enhancement of resin adsorbability was attributed to the DBD plasma changing the surface physical and chemical structure.

  17. Surface treatment of aramid fiber by air dielectric barrier discharge plasma at atmospheric pressure

    International Nuclear Information System (INIS)

    Jia Caixia; Chen Ping; Liu Wei; Li Bin; Wang Qian

    2011-01-01

    Aramid fiber samples are treated by air dielectric barrier discharge (DBD) plasma at atmospheric pressure; the plasma treatment time is investigated as the major parameter. The effects of this treatment on the fiber surface physical and chemical properties are studied by using surface characterization techniques. Scanning electron microscopy (SEM) is performed to determine the surface morphology changes, X-ray photoelectron spectroscopy (XPS) is analyzed to reveal the surface chemical composition variations and dynamic contact angle analysis (DCAA) is used to examine the changes of the fiber surface wettability. In addition, the wetting behavior of a kind of thermoplastic resin, poly(phthalazinone ether sulfone ketone) (PPESK), on aramid fiber surface is also observed by SEM photos. The study shows that there seems to be an optimum treatment condition for surface modification of aramid fiber by the air DBD plasma. In this paper, after the 12 s, 27.6 W/cm 3 plasma treatment the aramid fiber surface roughness is significantly improved, some new oxygen-containing groups such as C-O, C=O and O=C-O are generated on the fiber surface and the fiber surface wettability is greatly enhanced, which results in the better wetting behavior of PPESK resin on the plasma-treated aramid fiber.

  18. Surface Treatment of Polypropylene Films Using Dielectric Barrier Discharge with Magnetic Field

    International Nuclear Information System (INIS)

    Wang Changquan; Zhang Guixin; Wang Xinxin; Chen Zhiyu

    2012-01-01

    Atmospheric pressure non-thermal plasma is of interest for industrial applications. In this study, polypropylene (PP) films are modified by a dielectric barrier discharge (DBD) with a non-uniform magnetic field in air at atmospheric pressure. The surface properties of the PP films before and after a DBD treatment are studied by using contact angle measurement, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The effect of treatment time on the surface modification with and without a magnetic field is investigated. It is found that the hydrophilic improvement depends on the treatment time and magnetic field. It is also found that surface roughness and oxygen-containing groups are introduced onto the PP film surface after the DBD treatment. Surface roughness and oxygen-containing polar functional groups of the PP films increase with the magnetic induction density. The functional groups are identified as C-O, C=O and O-C=O by using XPS analysis. It is concluded that the hydrophilic improvement of PP films treated with a magnetic field is due to a greater surface roughness and more oxygen-containing groups. (plasma technology)

  19. Design of the corona current measurement sensor with wide bandwidth under dc ultra-high-voltage environment

    International Nuclear Information System (INIS)

    Liu, Yingyi; Yuan, Haiwen; Yang, Qinghua; Cui, Yong

    2011-01-01

    The research in the field of corona discharge, which is one of the key technologies, can help us to realize ultra-high-voltage (UHV) power transmission. This paper proposes a new sampling resistance sensor to measure the dc UHV corona current in a wide band. By designing the structural and distributed parameters of the sensor, the UHV dielectric breakdown performance and the wide-band measuring characteristics of the sensor are satisfied. A high-voltage discharge test shows that the designed sensor can work under a 1200 kV dc environment without the occurrence of corona discharge. A frequency characteristic test shows that the measuring bandwidth of the sensor can be improved from the current 4.5 to 20 MHz. The test results in an actual dc UHV transmission line demonstrate that the sensor can accurately measure the corona current under the dc UHV environment

  20. Treatment of Egyptian Maghara coal by plasma ozone synthesized by silent discharge

    CERN Document Server

    Salem, M A; Garamoon, A A; Hassouba, M A

    2003-01-01

    A sample of pyrite rich bituminous coal collected from the main coal seam of Maghara mine, northern sinai, was treated by ozone plasma. The latter was synthesized using silent discharge method (10 kv a.c. and 50 hz). The room temperature Moessbauer spectra of untreated coal sample was easily fitted to two doublet, whose parameters matched those of pyrite (FeS sub 2) and sulfate (FeSO sub 4.H sub 2 O) in addition to hematite. After treatment by ozone plasma, a doublet ascribed to pyrite was observed. The extent of pyrite oxidation to jarosite (Fe sub 2 (SO sub 4) sub 3. nH sub 2 O) was monitored by their relative spectral areas, the incomplete oxidation of pyrite may be attributed to the presence of calcium sulfate layer which acts a screen of ozone.

  1. 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.

  2. Chemical corrosion by chlorides on ancient-like bronzes and treatment by hydrogen glow discharge plasma

    Science.gov (United States)

    Papadopoulou, O.; Novakovic, J.; Vassiliou, P.; Filippaki, E.; Bassiakos, Y.

    2013-12-01

    Three representative ancient-like bronzes are employed for the chemical synthesis of Cu2(OH)3Cl rich patinas in order to study the influence of the alloying elements in the evolution of the chloride attack and to further conduct stabilization treatment via Hydrogen Glow Discharge Plasma (HGDP) at low temperature and pressure. The corrosion behavior of specimens having Sn and Pb as main alloying elements is governed by a decuprification mechanism and by the formation of Sn-Pb-O enriched barrier layers. In the case of the Zn containing alloy, dezincification is more pronounced at the corrosion initial stages, and copper species predominate the corrosion products evolution. A three-hour HGDP treatment leads to Cu+ production and metallic Cu, Sn, Zn, and Pb redeposition, as a result of metal cation reduction. This process is accompanied by partial removal of Cl species, O diminution, and change in coloration. The further increase of the Cl/O atomic ratio measured on the post-treated surfaces leads to the formation of nantokite and thus to the conclusion that the stabilization of objects with extensive Cl attack is not feasible by HGDP without preliminary chemical treatment.

  3. Deactivation and treatment of mine wastewaters and of aqueous solutions discharged in uranium ore treatment and processing

    International Nuclear Information System (INIS)

    Jilek, R.; Prochazka, H.; Fuska, J.; Nemec, P.; Katzer, J.

    1974-01-01

    A description is presented of decontamination and purification of mine wastewaters and water solutions discharged from uranium ore treatment and processing and of the simultaneous removal and concentration of uranium-radium daughters, mainly of 226 Ra and 210 Pb. These elements are incorporated in the mycelium of microorganisms, such as those of the Fungi imperfecti class or are sorbed on the mycelium surface. The mycelia are then mechanically separated from the decontaminated solution, e.g., by filtration, centrifugation or sedimentation. The mycelium may be cultivated in the purified solutions to which nutrients are added, such as carbon, nitrogen and phosphorus in concentrations necessary for the growth of the microorganisms used. The mycelium may be added to the purified solution either in the native or in the dried state. (B.S.)

  4. Propagation characteristics of audible noise generated by single corona source under positive DC voltage

    Directory of Open Access Journals (Sweden)

    Xuebao Li

    2017-10-01

    Full Text Available The directivity and lateral profile of corona-generated audible noise (AN from a single corona source are measured through experiments carried out in the semi-anechoic laboratory. The experimental results show that the waveform of corona-generated AN consists of a series of random sound pressure pulses whose pulse amplitudes decrease with the increase of measurement distance. A single corona source can be regarded as a non-directional AN source, and the A-weighted SPL (sound pressure level decreases 6 dB(A as doubling the measurement distance. Then, qualitative explanations for the rationality of treating the single corona source as a point source are given on the basis of the Ingard’s theory for sound generation in corona discharge. Furthermore, we take into consideration of the ground reflection and the air attenuation to reconstruct the propagation features of AN from the single corona source. The calculated results agree with the measurement well, which validates the propagation model. Finally, the influence of the ground reflection on the SPL is presented in the paper.

  5. The detailed characteristics of positive corona current pulses in the line-to-plane electrodes

    Science.gov (United States)

    Xuebao, LI; Dayong, LI; Qian, ZHANG; Yinfei, LI; Xiang, CUI; Tiebing, LU

    2018-05-01

    The corona current pulses generated by corona discharge are the sources of the radio interference from transmission lines and the detailed characteristics of the corona current pulses from conductor should be investigated in order to reveal their generation mechanism. In this paper, the line-to-plane electrodes are designed to measure and analyze the characteristics of corona current pulses from positive corona discharges. The influences of inter-electrode gap and line diameters on the detail characteristics of corona current pulses, such as pulse amplitude, rise time, duration time and repetition frequency, are carefully analyzed. The obtained results show that the pulse amplitude and the repetition frequency increase with the diameter of line electrode when the electric fields on the surface of line electrodes are same. With the increase of inter-electrode gap, the pulse amplitude and the repetition frequency first decrease and then turn to be stable, while the rise time first increases and finally turns to be stable. The distributions of electric field and space charges under the line electrodes are calculated, and the influences of inter-electrode gap and line electrode diameter on the experimental results are qualitatively explained.

  6. Hydrogen Peroxide and Ozone Formation in Hybrid Gas-Liquid Electrical Discharge Reactors

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Appleton, A. T.; Locke, B. R.

    2004-01-01

    Roč. 40, č. 1 (2004), s. 60-67 ISSN 0093-9994. [IEEE Industry Applications Society Annual Meeting 2002/37th./. Pittsburgh, Pennsylvania , 13.10.2002-18.10.2002] R&D Projects: GA ČR GA202/02/1026; GA MŠk ME 472 Grant - others:NSF(US) INT0086351 Keywords : hydrogen peroxide, ozone, corona discharge, water treatment, hybrid reactor Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.987, year: 2004

  7. Characteristics and Biodegradability of Wastewater Organic Matter in Municipal Wastewater Treatment Plants Collecting Domestic Wastewater and Industrial Discharge

    Directory of Open Access Journals (Sweden)

    Yun-Young Choi

    2017-06-01

    Full Text Available Municipal wastewater treatment plants (WWTPs in Korea collect and treat not only domestic wastewater, but also discharge from industrial complexes. However, some industrial discharges contain a large amount of non-biodegradable organic matter, which cannot be treated properly in a conventional biological WWTP. This study aimed to investigate the characteristics and biodegradability of the wastewater organic matter contained in the industrial discharges and to examine the fate of the industrial discharges in a biological WWTP. In contrast to most previous studies targeting a specific group of organic compounds or traditional water quality indices, such as biological oxygen demand (BOD and chemical oxygen demand (COD, this study was purposed to quantify and characterize the biodegradable and nonbiodegradable fractions of the wastewater organic matter. Chemical oxygen demand (COD fractionation tests and fluorescence spectroscopy revealed that the industrial discharge from dyeing or pulp mill factories contained more non-biodegradable soluble organic matter than did the domestic wastewater. Statistical analysis on the WWTPs’ monitoring data indicated that the industrial discharge containing non-biodegradable soluble organic matter was not treated effectively in a biological WWTP, but was escaping from the system. Thus, industrial discharge that contained non-biodegradable soluble organic matter was a major factor in the decrease in biodegradability of the discharge, affecting the ultimate fate of wastewater organic matter in a biological WWTP. Further application of COD fractionation and fluorescence spectroscopy to wastewaters, with various industrial discharges, will help scientists and engineers to better design and operate a biological WWTP, by understanding the fate of wastewater organic matter.

  8. Treatment and Reuse of Wastewaters Discharged by Petroleum Industries (HMD/Algeria)

    Energy Technology Data Exchange (ETDEWEB)

    Sellami, MH, E-mail: sellami2000dz@gmail.com [Process Engineering Department, Laboratory of Process Engineering, Ouargla University (Algeria); Loudiyi, K [Renewable Energies Laboratory (REL) Al Akhawayne University, Ifrane (Morocco); Boubaker, MC; Habbaz, H [Process Engineering Department, Laboratory of Process Engineering, Ouargla University (Algeria)

    2015-12-23

    Industrial wastewaters discharged by petroleum industries contains: oil, heavy metals and chemicals used in the process of oil separation and treatment. These waters are a source of soil, water and air pollution, and lead a mortal danger to the ecosystem. Our aim in this work has an aspect that can contribute to the collective effort to address the enormous amount of water purges storage bins and reuse them to avoid any environmental damage. This was achieved by chemical treating of these wastewaters discharged from three different locations of Hassi Messaoud (HMD) petroleum field by flocculation with (C-5563) followed by coagulation with (C-2061) using two different acids as sequestering namely: Ascorbic and Citric acid. After experiments, the results showed that the wastewater can be treated without sequestering by adding 40 ppm of activated silicates. The best result was obtained by addition of 160 ppm of Ascorbic acid as sequestering agent and 20 ppm of activated silicates; resulting in removal of 92.81 % of suspended matter and 95.53 % of turbidity. Finally we concluded that this wastewater was satisfactorily treated and we recommend either inject it for enhanced oil recovery in industrial closest field (North field) to maintain the reservoir pressure and the improved rate recovery of oil reserves or reuse it in garden irrigation. In order to see the impact of the treated water on plants, irrigation tests have conducted on two types of plants (date palm and shaft apocalyptic) for one year. The tests showed that the thick layer of 5 cm and 0.08mm of particles diameter of dune sand removes most of remaining oil. The sand layer that fills the basin surrounding the shaft is removed and replaced every 06 months. So, Dune sand plays the role of natural filter. The garden plants appear and grow normally.

  9. Treatment and Reuse of Wastewaters Discharged by Petroleum Industries (HMD/Algeria)

    International Nuclear Information System (INIS)

    Sellami, MH; Loudiyi, K; Boubaker, MC; Habbaz, H

    2015-01-01

    Industrial wastewaters discharged by petroleum industries contains: oil, heavy metals and chemicals used in the process of oil separation and treatment. These waters are a source of soil, water and air pollution, and lead a mortal danger to the ecosystem. Our aim in this work has an aspect that can contribute to the collective effort to address the enormous amount of water purges storage bins and reuse them to avoid any environmental damage. This was achieved by chemical treating of these wastewaters discharged from three different locations of Hassi Messaoud (HMD) petroleum field by flocculation with (C-5563) followed by coagulation with (C-2061) using two different acids as sequestering namely: Ascorbic and Citric acid. After experiments, the results showed that the wastewater can be treated without sequestering by adding 40 ppm of activated silicates. The best result was obtained by addition of 160 ppm of Ascorbic acid as sequestering agent and 20 ppm of activated silicates; resulting in removal of 92.81 % of suspended matter and 95.53 % of turbidity. Finally we concluded that this wastewater was satisfactorily treated and we recommend either inject it for enhanced oil recovery in industrial closest field (North field) to maintain the reservoir pressure and the improved rate recovery of oil reserves or reuse it in garden irrigation. In order to see the impact of the treated water on plants, irrigation tests have conducted on two types of plants (date palm and shaft apocalyptic) for one year. The tests showed that the thick layer of 5 cm and 0.08mm of particles diameter of dune sand removes most of remaining oil. The sand layer that fills the basin surrounding the shaft is removed and replaced every 06 months. So, Dune sand plays the role of natural filter. The garden plants appear and grow normally

  10. Corona initiated from grounded objects under thunderstorm conditions and its influence on lightning attachment

    International Nuclear Information System (INIS)

    Bazelyan, E M; Raizer, Yu P; Aleksandrov, N L

    2008-01-01

    Lightning attachment to grounded structures due to the initiation of an upward connecting leader from them is considered taking into account the effect of corona space charge near the structures. It is shown that the corona space charge strongly affects the initiation and development of the connecting leader. Specific features of a non-stationary corona are analysed analytically and numerically for one-dimensional electrode geometries and for a grounded rod coronating in a slowly varying thundercloud electric field that can be enhanced by the charge of an approaching downward lightning leader. Initiation and development of an upward connecting leader or upward lightning from high ground objects are investigated. Prospects of using the effect of coronae to control downward lightning discharges are discussed.

  11. Cell treatment and surface functionalization using a miniature atmospheric pressure glow discharge plasma torch

    International Nuclear Information System (INIS)

    Yonson, S; Coulombe, S; Leveille, V; Leask, R L

    2006-01-01

    A miniature atmospheric pressure glow discharge plasma torch was used to detach cells from a polystyrene Petri dish. The detached cells were successfully transplanted to a second dish and a proliferation assay showed the transplanted cells continued to grow. Propidium iodide diffused into the cells, suggesting that the cell membrane had been permeabilized, yet the cells remained viable 24 h after treatment. In separate experiments, hydrophobic, bacteriological grade polystyrene Petri dishes were functionalized. The plasma treatment reduced the contact angle from 93 0 to 35 0 , and promoted cell adhesion. Two different torch nozzles, 500 μm and 150 μm in internal diameter, were used in the surface functionalization experiments. The width of the tracks functionalized by the torch, as visualized by cell adhesion, was approximately twice the inside diameter of the nozzle. These results indicate that the miniature plasma torch could be used in biological micropatterning, as it does not use chemicals like the present photolithographic techniques. Due to its small size and manouvrability, the torch also has the ability to pattern complex 3D surfaces

  12. Growth and male reproduction improvement of non-thermal dielectric barrier discharge plasma treatment on chickens

    Science.gov (United States)

    Jiao Zhang, Jiao; Luong Huynh, Do; Chandimali, Nisansala; Kang, Tae Yoon; Kim, Nameun; Mok, Young Sun; Kwon, Taeho; Jeong, Dong Kee

    2018-05-01

    This study investigated whether plasma treatment of fertilized eggs before hatching could affect the growth and reproduction of chickens. Three point five-day-incubated fertilized eggs exposed to non-thermal dielectric barrier discharge plasma at 2.81 W of power for 2 min resulted in the highest growth in chickens. Plasma growth-promoting effect was regulated by the reactive oxygen species homeostasis and the improvement of energy metabolism via increasing serum hormones and adenosine triphosphate levels which were resulted from the regulation of genes involved in antioxidant defense, hormone biosynthesis and energetic metabolism. Interestingly, plasma-treated male chickens conspicuously grew faster than females. Further, aspects of male reproductive system (testosterone level and sperm quality) were improved by the plasma treatment but female reproduction (estradiol and progesterone levels, egg-laying rate and egg weight) had no significant changes. Unfortunately, offspring whose parents were the optimal plasma-treated chickens did not show any difference on growth characteristics and failed to inherit excellent growth features from their parents. Our results suggest a new method to improve the growth rate and male reproductive capacity in poultry but it is only effective in the plasma direct-treated generation.

  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. Study and optimization of the partial discharges in capacitor model ...

    African Journals Online (AJOL)

    The initial potential as well as the temperature are known to influence the partial discharge ... The development of electrostatic industry has ... the liquid impregnation. One of the ..... the Surface of Corona charged Uniforms layers of HIPS.

  15. Treatment of discharge water from hydrostatic testing of natural gas pipelines. Volume 4. Topical report, January 1989-June 1992

    International Nuclear Information System (INIS)

    Tallon, J.T.; Lee-Ryan, P.B.; Volpi, K.A.; Fillo, J.P.

    1992-06-01

    The report presents results developed from bench- and full-scale treatment testing conducted on discharge water from hydrostatic testing of natural gas pipelines. Bench-scale testing examined sedimentation with and without chemical coagulants for reducing iron and total suspended solids, aeration for removal of volatile organics, and activated carbon adsorption for removal of organic constituents. Treatment results are provided for a full-scale treatment process, which utilized a hay bale structure and adsorbent booms for removing suspended solids and oil from the discharge water. Detailed characterization results are presented for test water collected before and after treatment. Results developed from an economic analysis of other potential treatment/disposal alternatives are also presented. A total of eight approaches that may be applied for managing constituents present in hydrostatic test waters are examined. The report is Volume 4 of a five-volume report series

  16. Treatment of EDTA contained reactor coolant using water dielectric barrier discharge plasma

    International Nuclear Information System (INIS)

    Song, Sang Heon; Kwon, Daniel; Kim, Gon Ho

    2005-01-01

    EDTA (Ethylene Diamine Tetraacetic Acid) is used as a main absorbent for the metal ion in the secondary loop of the nuclear reactor. Dissolving the wasted EDTA with low cost, therefore, is important issue for the maintenance of the nuclear power reactor and the protection of environment. EDTA is not easily biodegradable, furthermore these methods could make remained another pollutant as complex chemical compounds. Compared to chemical method, the physical methods, using the energetic particles and UVs, are more favorable because they dissociate the bonds of organic compounds directly without the secondary chemical reactions during the treatment. Recently, high energy electron beam, the plasma torch, and the water breakdown by high voltage pulse are applied to treatment of the waste water contained chemicals. Here consideration is narrow down to improve the interaction between the plasma and the chemical bonds of EDTA because the energetic particles; activated radicals, and UVs, are abundant in plasmas. The new method adapted of the water DBD (dielectric barrier discharge) which plasma generates directly on the top of the water contained EDTA is proposed. The application of DBD plasmas has been extended for cleaning the organic compounds from the contaminated surface and also for removing volatile organic chemicals (VOC) such as NO x and SO x from the exhausted gases. Here, the water DBD reactor (SEMTECH, SD-DWG-04-1) is consisted that the one electrode is a ceramic insulator and another one is the water itself. Interestingly, the one electrode, the water, is not the solid dielectric electrode. In this study, therefore, the characteristics with driving frequency are considered and the feasibility of this new method for the DBD treatment of EDTA contained water is demonstrated

  17. Introduction to investigations of the negative corona and EHD flow in gaseous two-phase fluids

    Science.gov (United States)

    Jerzy, MIZERACZYK; Artur, BERENDT

    2018-05-01

    Research interests have recently been directed towards electrical discharges in multi-phase environments. Natural electrical discharges, such as lightning and coronas, occur in the Earth’s atmosphere, which is actually a mixture of gaseous phase (air) and suspended solid and liquid particulate matters (PMs). An example of an anthropogenic gaseous multi-phase environment is the flow of flue gas through electrostatic precipitators (ESPs), which are generally regarded as a mixture of a post-combustion gas with solid PM and microdroplets suspended in it. Electrical discharges in multi-phase environments, the knowledge of which is scarce, are becoming an attractive research subject, offering a wide variety of possible discharges and multi-phase environments to be studied. This paper is an introduction to electrical discharges in multi-phase environments. It is focused on DC negative coronas and accompanying electrohydrodynamic (EHD) flows in a gaseous two-phase fluid formed by air (a gaseous phase) and solid PM (a solid phase), run under laboratory conditions. The introduction is based on a review of the relevant literature. Two cases will be considered: the first case is of a gaseous two-phase fluid, initially motionless in a closed chamber before being subjected to a negative corona (with the needle-to-plate electrode arrangement), which afterwards induces an EHD flow in the chamber, and the second, of a gaseous two-phase fluid flowing transversely with respect to the needle-to-plate electrode axis along a chamber with a corona discharge running between the electrodes. This review-based introductory paper should be of interest to theoretical researchers and modellers in the field of negative corona discharges in single- or two-phase fluids, and for engineers who work on designing EHD devices (such as ESPs, EHD pumps, and smoke detectors).

  18. Novel bioevaporation process for the zero-discharge treatment of highly concentrated organic wastewater.

    Science.gov (United States)

    Yang, Benqin; Zhang, Lei; Lee, Yongwoo; Jahng, Deokjin

    2013-10-01

    A novel process termed as bioevaporation was established to completely evaporate wastewater by metabolic heat released from the aerobic microbial degradation of the organic matters contained in the highly concentrated organic wastewater itself. By adding the glucose solution and ground food waste (FW) into the biodried sludge bed, the activity of the microorganisms in the biodried sludge was stimulated and the water in the glucose solution and FW was evaporated. As the biodegradable volatile solids (BVS) concentration in wastewater increased, more heat was produced and the water removal ratio increased. When the volatile solids (VS) concentrations of both glucose and ground FW were 120 g L(-1), 101.7% and 104.3% of the added water was removed, respectively, by completely consuming the glucose and FW BVS. Therefore, the complete removal of water and biodegradable organic contents was achieved simultaneously in the bioevaporation process, which accomplished zero-discharge treatment of highly concentrated organic wastewater. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Removal of antibiotics in conventional and advanced wastewater treatment: implications for environmental discharge and wastewater recycling.

    Science.gov (United States)

    Watkinson, A J; Murby, E J; Costanzo, S D

    2007-10-01

    Removal of 28 human and veterinary antibiotics was assessed in a conventional (activated sludge) and advanced (microfiltration/reverse osmosis) wastewater treatment plant (WWTP) in Brisbane, Australia. The dominant antibiotics detected in wastewater influents were cephalexin (med. 4.6 microg L(-1), freq. 100%), ciprofloxacin (med. 3.8 microg L(-1), freq. 100%), cefaclor (med. 0.5 microg L(-1), freq. 100%), sulphamethoxazole (med. 0.36 microg L(-1), freq. 100%) and trimethoprim (med. 0.34 microg L(-1), freq. 100%). Results indicated that both treatment plants significantly reduced antibiotic concentrations with an average removal rate from the liquid phase of 92%. However, antibiotics were still detected in both effluents from the low-to-mid ng L(-1) range. Antibiotics detected in effluent from the activated sludge WWTP included ciprofloxacin (med. 0.6 microg L(-1), freq. 100%), sulphamethoxazole (med. 0.27 microg L(-1), freq. 100%) lincomycin (med. 0.05 microg L(-1), freq. 100%) and trimethoprim (med. 0.05 microg L(-1), freq. 100%). Antibiotics identified in microfiltration/reverse osmosis product water included naladixic acid (med. 0.045 microg L(-1), freq. 100%), enrofloxacin (med. 0.01 microg L(-1), freq. 100%), roxithromycin (med. 0.01 microg L(-1), freq. 100%), norfloxacin (med. 0.005 microg L(-1), freq. 100%), oleandomycin (med. 0.005 microg L(-1), freq. 100%), trimethoprim (med. 0.005 microg L(-1), freq. 100%), tylosin (med. 0.001 microg L(-1), freq. 100%), and lincomycin (med. 0.001 microg L(-1), freq. 66%). Certain traditional parameters, including nitrate concentration, conductivity and turbidity of the effluent were assessed as predictors of total antibiotic concentration, however only conductivity demonstrated any correlation with total antibiotic concentration (p=0.018, r=0.7). There is currently a lack of information concerning the effects of these chemicals to critically assess potential risks for environmental discharge and water recycling.

  20. Skylab investigations of solar corona

    International Nuclear Information System (INIS)

    Krivsky, L.

    1976-01-01

    The findings are reported obtained by the observation of the Sun and its corona from Skylab. The most important findings include the discovery of explosive loop structures induced by eruptive phenomena below the corona, in the chromosphere. The front edge of the explosive loop structure was observed at a distance of 1,700,000 to 2,800,000 km from the Sun. The rate of prominence was around 500 km/s. The loop structure disturbed the original shape of the corona above the solar disk edge. A graph was plotted of the variation of the release of the expanding loop structure from the solar surface in millions of kilometers with time. The graph aided in refuting the erroneous assumption that the prominence was not associated with radio bursts similar to those induced by plasma shock waves. It was also shown that a prominent shock wave is present in the vicinity of the expanding structure front which, at lower levels, got released from the eruptive flare above the solar ''surface''. The knowledge obtained does not involve the Sun alone but is also valuable from the point of view of the prognosis of consequent magnetic anomalies in the interstellar space and geomagnetic disturbances on the Earth. (Z.S.)

  1. Polyester composites reinforced with corona-treated fibers from pine, eucalyptus and sugarcane bagasse

    Science.gov (United States)

    This study aims to evaluate plant fibers that were surface activated with NaOH and corona discharge before incorporating in ortho unsaturated polyester-based fiber composites. It demonstrates the potential use of lignocellulosic particles, especially eucalyptus that presented the higher values for a...

  2. Low-level NOx removal in ambient air by pulsed corona technology

    NARCIS (Netherlands)

    Beckers, F.J.C.M.; Hoeben, W.F.L.M.; Pemen, A.J.M.; Heesch, van E.J.M.

    2013-01-01

    Although removal of NOx by (pulsed) corona discharges has been thoroughly investigated for high concentrations of NOx in flue gas, removal of low levels in ambient air proves to be a difficult task. (Sub) ppm NOx levels exist in traffic tunnels due to accumulation of exhaust gases. The application

  3. Silent Discharge Plasma Technology for the Treatment of Air Toxics and Other Applications

    Energy Technology Data Exchange (ETDEWEB)

    Rosocha, Louis A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chase, Peter J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gross, Michael P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    1998-09-21

    Under this CRADA, the Los Alamos National Laboratory (LANL) and High Mesa Technologies, Inc. (HMT) carried out a joint project on the development of the silent discharge plasma (SDP) technology for the treatment of hazardous air pollutants and other hazardous or toxic chemicals. The project had two major components: a technology-demonstration part and a scale-up and commercialization part. In the first part, a small-scale, mobile SDP plasma processor, which was being developed under a CRADA with the Electric Power Research Institute (EPRI) was the mobile equipment was modified for higher capacity service and employed for an innovative remediation technologies demonstration on soil-vapor extraction off-gases at the McClellan Air Force Base near Sacramento, CA. The performance of the SDP system for the variety of volatile organic compounds (VOCs) encountered at the McClellan site was sufficiently promising to the project HMT and LANL worked together to formulate a scale-up strategy and commercialization/manufacturing plan, and to design a prototype scaled-up SDP unit. HMT and LANL are now in the final stages of completing a licensing agreement for the technology and HMT is in the process of raising funds to engineer and manufacture commercial prototype SDP equipment focused on stack-gas emissions control and environmental remediation. HMT, in collaboration with another Northern New Mexico business, Coyote Aerospace, has also been successful in receiving a Phase I Small Business Innovative Research (SBIR) award from the Army Research Office to develop, design, and construct a small non-thermal plasma reactor for laboratory studies ("Non-Thermal Plasma Reactor for Control of Fugitive Emissions of Toxic Gases")

  4. Effects of Dielectric Barrier Discharge Plasma Treatment on Pentachlorophenol Removal of Granular Activated Carbon

    International Nuclear Information System (INIS)

    Ji Puhui; Qu Guangzhou; Li Jie

    2013-01-01

    The pentachlorophenol (PCP) adsorbed granular activated carbon (GAC) was treated by dielectric barrier discharge (DBD) plasma. The effects of DBD plasma on the structure of GAC and PCP decomposition were analyzed by N 2 adsorption, thermogravimetric, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and gas chromatography mass spectrometry (GC-MS). The experimental data of adsorption kinetics and thermodynamics of PCP on GAC were fitted with different kinetics and isotherm models, respectively. The results indicate that the types of N 2 adsorption isotherm of GAC are not changed by DBD plasma, while the specific surface area and pore volume increase after DBD plasma treatment. It is found that the weight loss of the saturated GAC is the highest, on the contrary, the weight loss of DBD treated GAC is the least because of reduced PCP residue on the GAC. The XPS spectra and SEM image suggest that some PCP on the GAC is removed by DBD plasma, and the surface of GAC treated by DBD plasma presents irregular and heterogeneous morphology. The GC-MS identification of by-products shows that two main dechlorination intermediate products, tetrachlorophenol and trichlorophenol, are distinguished. The fitting results of experimental data of adsorption kinetics and thermodynamics indicate that the pseudo-first-order and pseudo-second order models can be used for the prediction of the kinetics of virgin GAC and DBD treated GAC for PCP adsorption, and the Langmuir isotherm model fits better with the data of adsorption isotherm than the Freundlich isotherm in the adsorption of PCP on virgin GAC and DBD treated GAC

  5. Landau Damping and Anomalous Skin Effect in Low-pressure Gas Discharges: Self-consistent Treatment of Collisionless Heating

    International Nuclear Information System (INIS)

    Kaganovich, Igor D.; Polomarov, Oleg V.; Theodosiou, Constantine E.

    2004-01-01

    In low-pressure discharges, where the electron mean free path is larger or comparable with the discharge length, the electron dynamics is essentially nonlocal. Moreover, the electron energy distribution function (EEDF) deviates considerably from a Maxwellian. Therefore, an accurate kinetic description of the low-pressure discharges requires knowledge of the nonlocal conductivity operator and calculation of the non-Maxwellian EEDF. The previous treatments made use of simplifying assumptions: a uniform density profile and a Maxwellian EEDF. In the present study a self-consistent system of equations for the kinetic description of nonlocal, nonuniform, nearly collisionless plasmas of low-pressure discharges is reported. It consists of the nonlocal conductivity operator and the averaged kinetic equation for calculation of the non-Maxwellian EEDF. This system was applied to the calculation of collisionless heating in capacitively and inductively coupled plasmas. In particular, the importance of accounting for the nonuniform plasma density profile for computing the current density profile and the EEDF is demonstrated. The enhancement of collisionless heating due to the bounce resonance between the electron motion in the potential well and the external radio-frequency electric field is investigated. It is shown that a nonlinear and self-consistent treatment is necessary for the correct description of collisionless heating

  6. Study of a dual frequency atmospheric pressure corona plasma

    International Nuclear Information System (INIS)

    Kim, Dan Bee; Moon, S. Y.; Jung, H.; Gweon, B.; Choe, Wonho

    2010-01-01

    Radio frequency mixing of 2 and 13.56 MHz was investigated by performing experimental measurements on the atmospheric pressure corona plasma. As a result of the dual frequency, length, current density, and electron excitation temperature of the plasma were increased, while the gas temperature was maintained at roughly the same level when compared to the respective single frequency plasmas. Moreover, observation of time-resolved images revealed that the dual frequency plasma has a discharge mode of 2 MHz positive streamer, 2 MHz negative glow, and 13.56 MHz continuous glow.

  7. Performance evaluation of oxygen adsorbents using negative corona discharge–ion mobility spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Azadkish, Kamal; Jafari, Mohammad T., E-mail: jafari@cc.iut.ac.ir; Ghaziaskar, Hassan S.

    2017-02-08

    Trace amounts of oxygen was determined using negative corona discharge as an ionization source for ion mobility spectrometry. A point-in-cylinder geometry with novel design was used to establish the corona discharge without interferences of negative ions such as NO{sub X}{sup −}. The desirable background spectrum shows only electrons peak, providing the instrument capable of trace analysis of oxygen in gaseous samples. The limit of detection and linear dynamic range with high coefficient of determination (r{sup 2} = 0.9997), were obtained for oxygen as 8.5 and 28–14204 ppm, respectively. The relative standard deviations of the method for intraday and interday were obtained 4 and 11%, respectively. The satisfactory results revealed the ability of the negative corona discharge ion mobility spectrometry for investigating the performance of synthesized oxygen adsorbents in nitrogen streams. Two oxygen scavengers of MnO and Cu powder were prepared and the optimum temperature of the reactor containing MnO and Cu powder were obtained as 180 and 230 °C, respectively. Due to higher lifetime of copper powder, it was selected as the oxygen scavenger and some parameters such as: the type of adsorbent support, the size of adsorbent particles, and the amount of copper were studied for preparation of more efficient oxygen adsorbent. - Highlights: • Analysis of oxygen using negative corona discharge-ion mobility spectrometry was investigated for the first time. • Novel designed point-in-cylinder geometry was used to establish the corona discharge without interferences of negative ions. • The method was utilized to evaluate the performance of some synthesized oxygen scavengers.

  8. High Power DC Diaphragm Discharge Excited in a Vapor Bubble for the Treatment of Water

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Člupek, Martin; Babický, Václav; Doležalová, Eva; Sisrová, Irena; Maršálková, Eliška; Maršálek, Blahoslav

    2013-01-01

    Roč. 33, č. 1 (2013), s. 83-95 ISSN 0272-4324 R&D Projects: GA AV ČR IAAX00430802; GA ČR(CZ) GD104/09/H080 Institutional support: RVO:61389021 ; RVO:67985939 Keywords : Diaphragm discharge * Water * Hydrogen peroxide * Phenol * Bacteria * Algae Subject RIV: BL - Plasma and Gas Discharge Physics; EF - Botanics (BU-J) Impact factor: 1.599, year: 2013 http://link.springer.com/content/pdf/10.1007%2Fs11090-012-9432-6.pdf

  9. Dynamics of a lightning corona sheath—A constant field approach using the generalized traveling current source return stroke model

    Science.gov (United States)

    Cvetic, Jovan; Heidler, Fridolin; Markovic, Slavoljub; Radosavljevic, Radovan; Osmokrovic, Predrag

    2012-11-01

    A generalized lightning traveling current source return stroke model has been used to examine the characteristics of the lightning channel corona sheath surrounding a thin channel core. A model of the lightning channel consisting of a charged corona sheath and a narrow, highly conducting central core that conducts the main current flow is assumed. Strong electric field, with a predominant radial direction, has been created during the return stroke between the channel core and the outer channel sheath containing the negative charge. The return stroke process is modeled with the positive charge coming from the channel core discharging the negative leader charge in the corona sheath. The corona sheath model that predicts the charge motion in the sheath is used to derive the expressions of the sheath radius vs. time during the return stroke. According to the corona sheath model proposed earlier by Maslowski and Rakov (2006) and Maslowski et al. (2009), it consists of three zones, zone 1 (surrounding channel core with net positive charge), zone 2 (surrounding zone 1 with negative charge) and zone 3 (outer zone representing the virgin air without charges). We adopted the assumption of a constant electric field inside zone 1 of the corona sheath observed in the experimental research of corona discharges in a coaxial geometry by Cooray (2000). This assumption seems to be more realistic than the assumption of a uniform corona space charge density used previously in the study of Maslowski and Rakov (2006), Marjanovic and Cvetic (2009), and Tausanovic et al. (2010). Applying the Gauss' law on the infinitesimally small cylindrical section of the channel the expressions for time-dependence of the radii of zones 1 and 2 during the return stroke are derived. The calculations have shown that the overall channel dynamics concerning electrical discharge is roughly 50% slower and the maximum radius of zone 1 is about 33% smaller compared to the corresponding values calculated in the

  10. 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.

  11. Investigation of electric discharge treatment of water for ammonium nitrogen removal

    International Nuclear Information System (INIS)

    Nazarenko, O.B.; Shubin, B.G.

    2007-01-01

    The possibility of water purification from ammonium nitrogen using pulsed electric discharge in water-air mixtures was investigated. The model solution of chlorous ammonium was used in experiments. The concentration of ions ammonium was about 300 mg/l. Achieved reduction of ammonium concentration was about 35%. In this paper the mechanism of this process is discussed. The ways to increasing efficiency of this method are proposed

  12. Ceramic core with polymer corona hybrid nanocarrier for the treatment of osteosarcoma with co-delivery of protein and anti-cancer drug

    Science.gov (United States)

    Ram Prasad, S.; Sampath Kumar, T. S.; Jayakrishnan, A.

    2018-01-01

    For the treatment of metastatic bone cancer, local delivery of therapeutic agents is preferred compared to systemic administration. Delivery of an anti-cancer drug and a protein that helps in bone regeneration simultaneously is a challenging approach. In this study, a nanoparticulate carrier which delivers a protein and an anti-cancer drug is reported. Bovine serum albumin (BSA) as a model protein was loaded into hydroxyapatite (HA) nanoparticles (NPs) and methotrexate (MTX) conjugated to poly(vinyl alcohol) was coated onto BSA-loaded HA NPs. Coating efficiency was in the range of 10-17 wt%. In vitro drug release showed that there was a steady increase in the release of both BSA and MTX with 76% of BSA and 88% of MTX being released in 13 days. Cytotoxicity studies of the NPs performed using human osteosarcoma (OMG-63) cell line showed the NPs were highly biocompatible and exhibited anti-proliferative activity in a concentration-dependent manner.

  13. Pancreatitis - discharge

    Science.gov (United States)

    Chronic pancreatitis - discharge; Pancreatitis - chronic - discharge; Pancreatic insufficiency - discharge; Acute pancreatitis - discharge ... You were in the hospital because you have pancreatitis. This is a swelling of the pancreas. You ...

  14. Understanding the hydrologic impacts of wastewater treatment plant discharge to shallow groundwater: Before and after plant shutdown

    Science.gov (United States)

    Hubbard, Laura E.; Keefe, Steffanie H.; Kolpin, Dana W.; Barber, Larry B.; Duris, Joseph W.; Hutchinson, Kasey J.; Bradley, Paul M.

    2016-01-01

    Effluent-impacted surface water has the potential to transport not only water, but wastewater-derived contaminants to shallow groundwater systems. To better understand the effects of effluent discharge on in-stream and near-stream hydrologic conditions in wastewater-impacted systems, water-level changes were monitored in hyporheic-zone and shallow-groundwater piezometers in a reach of Fourmile Creek adjacent to and downstream of the Ankeny (Iowa, USA) wastewater treatment plant (WWTP). Water-level changes were monitored from approximately 1.5 months before to 0.5 months after WWTP closure. Diurnal patterns in WWTP discharge were closely mirrored in stream and shallow-groundwater levels immediately upstream and up to 3 km downstream of the outfall, indicating that such discharge was the primary control on water levels before shutdown. The hydrologic response to WWTP shutdown was immediately observed throughout the study reach, verifying the far-reaching hydraulic connectivity and associated contaminant transport risk. The movement of WWTP effluent into alluvial aquifers has implications for potential WWTP-derived contamination of shallow groundwater far removed from the WWTP outfall.

  15. Dynamics of the transition corona

    International Nuclear Information System (INIS)

    Masson, Sophie; McCauley, Patrick; Golub, Leon; Reeves, Katharine K.; DeLuca, Edward E.

    2014-01-01

    Magnetic reconnection between the open and closed magnetic fields in the corona is believed to play a crucial role in the corona/heliosphere coupling. At large scale, the exchange of open/closed connectivity is expected to occur in pseudo-streamer (PS) structures. However, there is neither clear observational evidence of how such coupling occurs in PSs, nor evidence for how the magnetic reconnection evolves. Using a newly developed technique, we enhance the off-limb magnetic fine structures observed with the Atmospheric Imaging Assembly and identify a PS-like feature located close to the northern coronal hole. We first identify that the magnetic topology associated with the observation is a PS, null-point (NP) related topology bounded by the open field. By comparing the magnetic field configuration with the EUV emission regions, we determined that most of the magnetic flux associated with plasma emission are small loops below the PS basic NP and open field bounding the PS topology. In order to interpret the evolution of the PS, we referred to a three-dimensional MHD interchange reconnection modeling the exchange of connectivity between small closed loops and the open field. The observed PS fine structures follow the dynamics of the magnetic field before and after reconnecting at the NP obtained by the interchange model. Moreover, the pattern of the EUV plasma emission is the same as the shape of the expected plasma emission location derived from the simulation. These morphological and dynamical similarities between the PS observations and the results from the simulation strongly suggest that the evolution of the PS, and in particular the opening/closing of the field, occurs via interchange/slipping reconnection at the basic NP of the PS. Besides identifying the mechanism at work in the large-scale coupling between the open and closed fields, our results highlight that interchange reconnection in PSs is a gradual physical process that differs from the impulsive

  16. Regulating industrial wastewater discharged to public wastewater treatment plants - A conceptual approach

    DEFF Research Database (Denmark)

    Grüttner, Henrik

    1997-01-01

    The paper describes some of the basic principles behind the DEPA Guidelines for discharge of industrial wastewater to public sewers set in operation in 1995 and evaluates some of the experiences with the implementation. It is described how such guidelines support the approach of pollution...... prevention and the implementation of cleaner technology by putting a stress on the industry. Further an approach for the balance between environmental and technological considerations is introduced. The need for easily understandable environmental priorities is stressed and a concept for this is presented...

  17. The effect of coronae on leader initiation and development under thunderstorm conditions and in long air gaps

    International Nuclear Information System (INIS)

    Aleksandrov, N.L.; Bazelyan, E.M.; Carpenter Jr, R.B.; Drabkin, M.M.; Raizer, Yu P.

    2001-01-01

    The initiation and development of a leader is theoretically studied by considering an electrode which is embedded in a cloud of space charge injected by a corona discharge. The focus is on the initiation of upward lightning from a stationary grounded object in a thundercloud electric field. The main results are also applicable to the leader process in long laboratory air gaps at direct voltage. Simple physical models of non-stationary coronae developing in free space near a solitary stressed sphere and of a leader propagating in the space charge cloud of coronae are suggested. It is shown that the electric field redistribution due to the space charge released by the long corona discharge near the top of a high object hinders the initiation and development of an upward leader from the object in a thundercloud electric field. The conditions for the formation of corona streamers that are required to initiate a leader are derived. The criteria are obtained for a leader to be initiated and propagate in the space charge cloud. A hypothesis is proposed that the streamers are never initiated near the top of a high object under thunderstorm conditions if at ground level there is only a slowly-varying electric field of the thundercloud. The streamers may be induced by the fast-rising electric field of distant downward leaders or intracloud discharges. (author)

  18. Charge-Discharge Properties of the Surface-Modified ZrNi Alloy Electrode with Different Degrees of Boiling Alkaline Treatment

    Directory of Open Access Journals (Sweden)

    Akihiro Matsuyama

    2016-09-01

    Full Text Available Charge-discharge properties of the surface-modified ZrNi negative electrodes with different degrees of boiling alkaline treatment were investigated. The boiling alkaline treatment was performed by immersing the ZrNi electrode in a boiling 6 M KOH aqueous solution for 2 h or 4 h. The initial discharge capacity for the untreated ZrNi negative electrode was 21 mAh·g−1, but it was increased to 114 mAh·g−1 and 308 mAh·g−1 after the boiling alkaline treatments for 2 h and 4 h, respectively. The discharge capacity for the ZrNi negative electrode after the treatment for 2 h steadily increased with repeating charge-discharge cycles as well as that of the untreated electrode, whereas that for the ZrNi negative electrode after the 4 h treatment greatly decreased. The high rate of dischargeability was improved with an increase in the treatment period of time, and the charge-transfer resistance was drastically decreased. Scanning electron microscopy (SEM and electron dispersive X-ray spectroscopy demonstrated the ZrO2 passive layer on the ZrNi alloy surface was removed by the boiling alkaline treatment to form a porous morphology containing Ni(OH2, which can be reduced to Ni during charging, leading to the reduction of a barrier for the charge-discharge reactions.

  19. A guide to the solar corona

    CERN Document Server

    Billings, Donald E

    1966-01-01

    A Guide to the Solar Corona is specifically directed to the space scientist or engineer who is not a specialist in solar physics, but whose work requires a fairly detailed knowledge of the corona. It is hoped that the material may prove useful to most graduate students in astrophysics, while solar physicists may find some topics of interest and value to them. The book contains 12 chapters and begins with three descriptive chapters that provide the casual reader with a concept of the corona as it is evident through more or less direct observation. Topics covered include the development of coron

  20. Heart pacemaker - discharge

    Science.gov (United States)

    Cardiac pacemaker implantation - discharge; Artificial pacemaker - discharge; Permanent pacemaker - discharge; Internal pacemaker - discharge; Cardiac resynchronization therapy - discharge; CRT - discharge; ...

  1. State waste discharge permit application for the 200 Area Effluent Treatment Facility and the State-Approved Land Disposal Site

    International Nuclear Information System (INIS)

    1993-08-01

    Application is being made for a permit pursuant to Chapter 173--216 of the Washington Administrative Code (WAC), to discharge treated waste water and cooling tower blowdown from the 200 Area Effluent Treatment Facility (ETF) to land at the State-Approved Land Disposal Site (SALDS). The ETF is located in the 200 East Area and the SALDS is located north of the 200 West Area. The ETF is an industrial waste water treatment plant that will initially receive waste water from the following two sources, both located in the 200 Area on the Hanford Site: (1) the Liquid Effluent Retention Facility (LERF) and (2) the 242-A Evaporator. The waste water discharged from these two facilities is process condensate (PC), a by-product of the concentration of waste from DSTs that is performed in the 242-A Evaporator. Because the ETF is designed as a flexible treatment system, other aqueous waste streams generated at the Hanford Site may be considered for treatment at the ETF. The origin of the waste currently contained in the DSTs is explained in Section 2.0. An overview of the concentration of these waste in the 242-A Evaporator is provided in Section 3.0. Section 4.0 describes the LERF, a storage facility for process condensate. Attachment A responds to Section B of the permit application and provides an overview of the processes that generated the wastes, storage of the wastes in double-shell tanks (DST), preliminary treatment in the 242-A Evaporator, and storage at the LERF. Attachment B addresses waste water treatment at the ETF (under construction) and the addition of cooling tower blowdown to the treated waste water prior to disposal at SALDS. Attachment C describes treated waste water disposal at the proposed SALDS

  2. Osmosis process for leachate treatment in industrial platform: Economic and performances evaluations to zero liquid discharge.

    Science.gov (United States)

    Cingolani, Diego; Eusebi, Anna Laura; Battistoni, Paolo

    2017-12-01

    The industrial processes require large quantities of water. The presence of discharges results not only in significant environmental impact but implies wastage of water resources. This problem could be solved treating and reusing the produced wastewaters and applying the new zero liquid discharge approach. This paper discusses the design and the performances of reverse osmosis membranes for the upgrading of full scale platform for industrial liquid wastes. The final effluent from the ultrafiltration unit of the full scale plant was monitored to design the reverse osmosis unit. Previous modelling phase was used to evaluate the specific ordinary and maintenance costs and the final effluent quality (2.7 €/m 3 ). The system was designed in triple stages at different operative pressures. The economic feasibility and the payback period of the technology at different percentages of produced permeate were determined. The recovery of 90% was identified as profitable for the reverse osmosis application. One experimental pilot plant applying the reverse osmosis was used to test the final effluent. Moreover, the same flow was treated with second pilot system based on the forward osmosis process. The final efficiencies were compared. Removals higher than 95% using the reverse system were obtained for the main macropollutants and ions. No sustainable applicability of the forward osmosis was determined. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Heart attack - discharge

    Science.gov (United States)

    ... and lifestyle Cholesterol - drug treatment Controlling your high blood pressure Deep vein thrombosis - discharge Dietary fats explained Fast food tips Heart attack - discharge Heart attack - what to ask your doctor Heart bypass ... pacemaker - discharge High blood pressure - what to ask your doctor How to read ...

  4. Low-level NOx removal in ambient air by pulsed corona technology

    International Nuclear Information System (INIS)

    Beckers, F J C M; Hoeben, W F L M; Pemen, A J M; Van Heesch, E J M

    2013-01-01

    Although removal of NO x by (pulsed) corona discharges has been thoroughly investigated for high concentrations of NO x in flue gas, removal of low levels in ambient air proves to be a difficult task. (Sub) ppm NO x levels exist in traffic tunnels due to accumulation of exhaust gases. The application of pulsed corona technology for purification of traffic tunnel air is studied during a series of lab and field experiments. An industrial pilot scale wire-cylinder type corona reactor has been utilized. Lab tests have been carried out using a diesel generator as NO x source. NO x conversion levels have been determined by applying two Recordum Airpointers (chemiluminescence-based detection). The detector appeared to be cross-sensitive for HNO 3 and high levels of O 3 . NO x removal rates of 60–80% were obtained for inlet levels of 2–10 ppm. The SIE value of 10 ppm NO x removal is 7 J l −1 . The corona discharges produce ppm level NO x at high energy densities. This intrinsic NO x production limits removal of inlet levels due to equilibrium between production and oxidation. (paper)

  5. Specific job anxiety in comparison to general psychosomatic symptoms at admission, discharge and six months after psychosomatic inpatient treatment.

    Science.gov (United States)

    Muschalla, Beate; Linden, Michael

    2012-01-01

    Job anxiety is a severe problem in many patients with chronic mental disorders, as it usually results in specific participation problems in the workplace and long-term sick leave. The aim of this study was to explore the development of sick leave in dependence on general psychosomatic complaints and job anxiety from admission to a psychosomatic inpatient treatment until 6 months after discharge. A convenience sample of 91 patients, suffering from multiple mental disorders, filled in self-rating questionnaires on job anxiety (Job Anxiety Scale) and on general psychosomatic symptom load (Symptom Checklist-90-Revised) at the beginning, the end, and 6 months after discharge from an inpatient psychosomatic treatment. Additionally, sick leave status and employment status were assessed before and 6 months after the treatment. 15.4% of 91 patients were on sick leave before inpatient treatment and at follow-up (SS group), 20.9% were fit for work at intake and follow-up (FF group), 6.6% were fit for work initially and on sick leave later (FS group), and 57.1% on sick leave first and working at follow-up (SF group). In regard to general psychosomatic complaints, there were initially high scores on the SCL, a marked reduction during inpatient treatment, and a bouncing back to initial levels at follow-up for all 4 patient groups. SS and FS patients showed the highest scores at intake and follow-up. Concerning job anxiety, SS patients had the highest scores at all three assessments, while FF patients had significantly lower scores, with only low variation between assessments. SF patients started with comparatively high scores of job anxiety, which even increased before reentering work, but decreased in the follow-up period when they were confronted with work again. FS patients started low (like the FF patients) at intake, reduced their job anxiety further till discharge, but increased to higher scores at follow-up. General psychosomatic symptom load and job anxiety show a

  6. Limited activity and social participation after hospital discharge from leprosy treatment in a hyperendemic area in north Brazil

    Directory of Open Access Journals (Sweden)

    Lorena Dias Monteiro

    2014-03-01

    Full Text Available INTRODUCTION: Neural damages are among the main factors that contribute to physical disability in leprosy. Systematic monitoring using a broad physical, psychological and social approach is necessary. OBJECTIVE: The objective of this study was to characterize the limitation of activity and social participation and its correlation with disabilities and/or impairment in individuals after being discharged from a multidrug leprosy therapy. METHOD: A cross-sectional study conducted in Araguaína, state of Tocantins, which is a leprosy hyperendemic municipality. We included cases of patients who were discharged from treatment considered as cured from January 2004 to December 2009. We performed dermatological examination and applied the Screening Activity Limitation and Safety Awareness (SALSA and social participation scales. RESULTS: We included 282 individuals (mean age: 45.8 years old. The paucibacillary operational classification was more common (170; 60.3%. The eye-hand-foot score ranged from 0 to 12 (mean: 0.7. A total of 84 (29.8% individuals presented limited activity. A slight restriction in social participation occurred in 18 (6.3% cases. There was a statistically significant correlation between activity limitation, age (r = 0.40; p < 0.0001 and degree of functional limitation (r = 0.54; p < 0.0001, as well as of restricted social participation, activity limitation (r = 0.56, p < 0.0001 and functional limitations (r = 0.54, p < 0.0001. CONCLUSION: Functional limitation due to leprosy had an impact on the conduct of activities and social participation after the discharge from a leprosy treatment. The association between Screening of Activity Limitation and Safety Awareness and participation scales will assist in designing evidence-based assistance measures.

  7. Protein Corona Analysis of Silver Nanoparticles Links to Their Cellular Effects.

    Science.gov (United States)

    Juling, Sabine; Niedzwiecka, Alicia; Böhmert, Linda; Lichtenstein, Dajana; Selve, Sören; Braeuning, Albert; Thünemann, Andreas F; Krause, Eberhard; Lampen, Alfonso

    2017-11-03

    The breadth of applications of nanoparticles and the access to food-associated consumer products containing nanosized materials lead to oral human exposure to such particles. In biological fluids nanoparticles dynamically interact with biomolecules and form a protein corona. Knowledge about the protein corona is of great interest for understanding the molecular effects of particles as well as their fate inside the human body. We used a mass spectrometry-based toxicoproteomics approach to elucidate mechanisms of toxicity of silver nanoparticles and to comprehensively characterize the protein corona formed around silver nanoparticles in Caco-2 human intestinal epithelial cells. Results were compared with respect to the cellular function of proteins either affected by exposure to nanoparticles or present in the protein corona. A transcriptomic data set was included in the analyses in order to obtain a combined multiomics view of nanoparticle-affected cellular processes. A relationship between corona proteins and the proteomic or transcriptomic responses was revealed, showing that differentially regulated proteins or transcripts were engaged in the same cellular signaling pathways. Protein corona analyses of nanoparticles in cells might therefore help in obtaining information about the molecular consequences of nanoparticle treatment.

  8. Modeling of Trichel pulses in negative corona

    International Nuclear Information System (INIS)

    Napartovich, A.P.; Akishev, Yu. S.; Deryugin, A.A.; Kochetov, I.V.; Pan'kin, M.V.; Trushkin, N.I.

    1998-01-01

    Results are reported of detailed numerical studies of Trichel pulse formation for dry air in short-gap coronas. Continuity equations for electrons, positive and negative ions, and the Poisson equation averaged over the current cross section were solved numerically with appropriate boundary conditions. The results of numerical simulation make it possible to analyze in detail the trailing edge of the Trichel pulse and the inter-pulse pause determining the period between pulses. In particular, the variations of the total number of negative ions in the corona spacing occurring under typical conditions of a pulsating corona, proved to be quite insignificant. A comparison with experiments demonstrated a reasonable agreement both for the shape of the pulse and for the average characteristics of the negative corona. (J.U.)

  9. The influence of the breakdown electric field in the configuration of lightning corona sheath on charge distribution in the channel

    Science.gov (United States)

    Ignjatovic, Milan; Cvetic, Jovan; Heidler, Fridolin; Markovic, Slavoljub; Djuric, Radivoje

    2014-11-01

    A model of corona sheath that surrounds the thin core of the lightning channel has been investigated by using a generalized traveling current source return stroke model. The lightning channel is modeled by a charged corona sheath that stretches around a highly conductive central core through which the main current flows. The channel core with the negatively charged outer channel sheath forms a strong electric field, with an overall radial orientation. The return stroke process is modeled as the negative leader charge in the corona sheath being discharged by the positive charge coming from the channel core. Expressions that describe how the corona sheath radius evolves during the return stroke are obtained from the corona sheath model, which predicts charge motion within the sheath. The corona sheath model, set forth by Maslowski and Rakov (2006), Tausanovic et al. (2010), Marjanovic and Cvetic (2009), Cvetic et al. (2011) and Cvetic et al. (2012), divides the sheath onto three zones: zone 1 (surrounding the channel core with net positive charge), zone 2 (surrounding zone 1 with negative charge) and zone 3 (the outer zone, representing uncharged virgin air). In the present study, we have assumed a constant electric field inside zone 1, as suggested by experimental research of corona discharges in coaxial geometry conducted by Cooray (2000). The present investigation builds upon previous studies by Tausanovic et al. (2010) and Cvetic et al. (2012) in several ways. The value of the breakdown electric field has been varied for probing its effect on channel charge distribution prior and during the return stroke. With the aim of investigating initial space charge distribution along the channel, total electric field at the outer surface of the channel corona sheath, just before the return stroke, is calculated and compared for various return stroke models. A self-consistent algorithm is applied to the generalized traveling current source return stroke model, so that the

  10. Estrogenic compounds in Tunisian urban sewage treatment plant: occurrence, removal and ecotoxicological impact of sewage discharge and sludge disposal.

    Science.gov (United States)

    Belhaj, Dalel; Athmouni, Khaled; Jerbi, Bouthaina; Kallel, Monem; Ayadi, Habib; Zhou, John L

    2016-12-01

    The occurrence, fate and ecotoxicological assessment of selected estrogenic compounds were investigated at Tunisian urban sewage treatment plant. The influents, effluents, as well as primary, secondary and dehydrated sludge, were sampled and analyzed for the target estrogens to evaluate their fate. All target compounds were detected in both sewage and sludge with mean concentrations from 0.062 to 0.993 μg L -1 and from 11.8 to 792.9 μg kg -1 dry weight, respectively. A wide range of removal efficiencies during the treatment processes were observed, from 6.3 % for estrone to 76.8 % for estriol. Ecotoxicological risk assessment revealed that the highest ecotoxicological risk in sewage effluent and dehydrated sludge was due to 17β-estradiol with a risk quotient (RQ) of 4.6 and 181.9, respectively, and 17α-ethinylestradiol with RQ of 9.8 and 14.85, respectively. Ecotoxicological risk after sewage discharge and sludge disposal was limited to the presence of 17β-estradiol in dehydrated-sludge amended soil with RQ of 1.38. Further control of estrogenic hormones in sewage effluent and sludge is essential before their discharge and application in order to prevent their introduction into the natural environment.

  11. Effect of dielectric barrier discharge treatment on surface nanostructure and wettability of polylactic acid (PLA) nonwoven fabrics

    Science.gov (United States)

    Ren, Yu; Xu, Lin; Wang, Chunxia; Wang, Xiaona; Ding, Zhirong; Chen, Yuyue

    2017-12-01

    Polylactic acid (PLA) nonwoven fabrics are treated with atmospheric dielectric barrier discharge (DBD) plasma to improve surface wettability. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) show that micro- to nano-scale textures appear on the treated PLA surfaces dependent on the treatment time. X-ray photoelectron spectroscopy (XPS) analysis reveals that the DBD plasma treatments result in decreased carbon contents and increased oxygen contents as well as slightly increased nitrogen contents. The water contact angle decreases sharply with the increase of the DBD plasma treatment time. The super hydrophilic PLA surfaces (the water contact angle reached 0°) are obtained when the treatment time is longer than 90 s. Ninety days after the DBD plasma treatment, the XPS analysis shows that Csbnd O/Csbnd N and Cdbnd O/Osbnd Cdbnd O percentages decline for all treatment groups. However, the water contact angle is kept constant at 0° for the groups treated above 90 s, which could be due to the oxidized nano-structured layer on the DBD plasma treated PLA surfaces.

  12. The Faraday rotation experiment. [solar corona

    Science.gov (United States)

    Volland, H.; Levy, G. S.; Bird, M. K.; Stelzried, C. T.; Seidel, B. L.

    1984-01-01

    The magnetized plasma of the solar corona was remotely sounded using the Faraday rotation effect. The solar magnetic field together with the electrons of the coronal plasma cause a measurable Faraday rotation effect, since the radio waves of Helios are linearly polarized. The measurement is performed at the ground stations. Alfven waves traveling from the Sun's surface through the corona into interplanetary space are observed. Helios 2 signals penetrating through a region where coronal mass is ejected show wavelike structures.

  13. Microsecond-pulsed dielectric barrier discharge plasma stimulation of tissue macrophages for treatment of peripheral vascular disease

    Energy Technology Data Exchange (ETDEWEB)

    Miller, V., E-mail: vmiller@coe.drexel.edu; Lin, A.; Brettschneider, J.; Fridman, G.; Fridman, A. [AJ Drexel Plasma Institute, Drexel University, Camden, New Jersey 08103 (United States); Kako, F.; Gabunia, K.; Kelemen, S.; Autieri, M. [Department of Physiology, Independence Blue Cross Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania 19140 (United States)

    2015-12-15

    Angiogenesis is the formation of new blood vessels from pre-existing vessels and normally occurs during the process of inflammatory reactions, wound healing, tissue repair, and restoration of blood flow after injury or insult. Stimulation of angiogenesis is a promising and an important step in the treatment of peripheral artery disease. Reactive oxygen species have been shown to be involved in stimulation of this process. For this reason, we have developed and validated a non-equilibrium atmospheric temperature and pressure short-pulsed dielectric barrier discharge plasma system, which can non-destructively generate reactive oxygen species and other active species at the surface of the tissue being treated. We show that this plasma treatment stimulates the production of vascular endothelial growth factor, matrix metalloproteinase-9, and CXCL 1 that in turn induces angiogenesis in mouse aortic rings in vitro. This effect may be mediated by the direct effect of plasma generated reactive oxygen species on tissue.

  14. Simulation of the AC corona phenomenon with experimental validation

    International Nuclear Information System (INIS)

    Villa, Andrea; Barbieri, Luca; Marco, Gondola; Malgesini, Roberto; Leon-Garzon, Andres R

    2017-01-01

    The corona effect, and in particular the Trichel phenomenon, is an important aspect of plasma physics with many technical applications, such as pollution reduction, surface and medical treatments. This phenomenon is also associated with components used in the power industry where it is, in many cases, the source of electro-magnetic disturbance, noise and production of undesired chemically active species. Despite the power industry to date using mainly alternating current (AC) transmission, most of the studies related to the corona effect have been carried out with direct current (DC) sources. Therefore, there is technical interest in validating numerical codes capable of simulating the AC phenomenon. In this work we describe a set of partial differential equations that are comprehensive enough to reproduce the distinctive features of the corona in an AC regime. The model embeds some selectable chemical databases, comprising tens of chemical species and hundreds of reactions, the thermal dynamics of neutral species and photoionization. A large set of parameters—deduced from experiments and numerical estimations—are compared, to assess the effectiveness of the proposed approach. (paper)

  15. Corona Associations and Their Implications for Venus

    Science.gov (United States)

    Chapman, M.G.; Zimbelman, J.R.

    1998-01-01

    Geologic mapping principles were applied to determine genetic relations between coronae and surrounding geomorphologic features within two study areas in order to better understand venusian coronae. The study areas contain coronae in a cluster versus a contrasting chain and are (1) directly west of Phoebe Regio (quadrangle V-40; centered at latitude 15??S, longitude 250??) and (2) west of Asteria and Beta Regiones (between latitude 23??N, longitude 239?? and latitude 43??N, longitude 275??). Results of this research indicate two groups of coronae on Venus: (1) those that are older and nearly coeval with regional plains, and occur globally; and (2) those that are younger and occur between Beta, Atla, and Themis Regiones or along extensional rifts elsewhere, sometimes showing systematic age progressions. Mapping relations and Earth analogs suggest that older plains coronae may be related to a near-global resurfacing event perhaps initiated by a mantle superplume or plumes. Younger coronae of this study that show age progression may be related to (1) a tectonic junction of connecting rifts resulting from local mantle upwelling and spread of a quasi-stationary hotspot plume, and (2) localized spread of post-plains volcanism. We postulate that on Venus most of the young, post-resurfacing coronal plumes may be concentrated within an area defined by the bounds of Beta, Atla, and Themis Regiones. ?? 1998 Academic Press.

  16. Effect of diagnosis and treatment of clinical endometritis based on vaginal discharge score grading system in postpartum Holstein cows.

    Science.gov (United States)

    Okawa, Hiroaki; Fujikura, Atsushi; Wijayagunawardane, Missaka M P; Vos, Peter L A M; Taniguchi, Masayasu; Takagi, Mitsuhiro

    2017-09-12

    In this study, the prevalence, effectiveness of diagnosis, and treatment based on vaginal discharge score (VDS) of clinical endometritis in cattle were evaluated. To detect clinical endometritis and classify its severity, vaginoscopy was performed during 21 to 60 days postpartum in 164 Holstein cows consisting of 229 lactations. Groups were defined using the 4-point VDS scale. Study groups included the following: non-endometritis (VDS=0; no/clear mucus; NEM group; n=168); mild endometritis, no treatment (VDS=1; mucus containing flecks of white/off-white pus; NTR group; n=30); and severe endometritis, treated with PGF2α (VDS≥2; discharge containing 50% pus, and fluid or uterine horn asymmetry; TEM group; n=31). Cows treated with PGF2α that did not recover (VDS≥1, n=5) received intrauterine procaine penicillin and streptomycin. Prevalence of clinical endometritis (VDS≥1) was 26.6%. The NTR group required significantly more artificial inseminations per pregnancy than NEM and TEM groups (2.8 ± 1.8 vs 2.0 ± 1.3, 1.9 ± 0.8, Pcows was higher in the NTR group compared to the NEM (P=0.012) and TEM (P=0.076) groups. In the TEM group, calving to first artificial insemination interval tended to be higher in cows treated 41 to 60 days postpartum than cows treated 29 to 40 days postpartum (97.2 ± 27.1 vs 74.4 ± 19.7, P=0.084). Our study suggests that cows with VDS=1 may require treatment to recover fertility. Diagnosis and treatment of clinical endometritis based on a VDS grading system may improve dairy herd reproductive performance.

  17. Plasma chemical and electrical modelling of a negative DC corona in pure oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Soria, C [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Sevilla (Spain); Pontiga, F [Departamento de FIsica Aplicada II, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Sevilla (Spain); Castellanos, A [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Sevilla (Spain)

    2004-02-01

    A complex plasma chemical and electrical model of a negative stationary wire-to-cylinder corona discharge in pure oxygen is presented. The corona discharge is assumed to have axial and azimuthal symmetry. The experimental current-voltage characteristic is required as input data, but there are no other adjustable or empirical parameters. The experimental validation of the results of the model comes from its prediction of the ozone concentration. The role played by different reactions and species is analysed in detail using the results of the simulation. The effect of the gas temperature and of the decomposition of ozone at the electrodes is also investigated. The agreement between the model and the experiments is excellent when the effect of ozone decomposition at the electrodes is taken into account.

  18. Mechanism for negative corona current pulse in CO sub 2 -SF sub 6 mixtures

    CERN Document Server

    Zahoranova, A; Simor, M; Cernak, M

    2003-01-01

    Current waveforms of first negative corona pulses have been measured in CO sub 2 -SF sub 6 mixtures over a pressure range extending from 6.65 to 50 kPa and various overvoltages. Effects of changing cathode secondary electron emission were studied using a copper cathode coated by CuI and graphite. For a given set of experimental conditions it is concluded that in the mixtures containing up to 30% of SF sub 6 the negative corona pulse is associated with the formation of a cathode-directed streamer-like ionizing wave in the immediate vicinity of the cathode. This is in contrast to the discharge behaviour in air-SF sub 6 and N sub 2 -SF sub 6 mixtures, where in similar conditions the discharge develops according to a multi-avalanche Townsend mechanism. (rapid communication)

  19. Plasma chemical and electrical modelling of a negative DC corona in pure oxygen

    International Nuclear Information System (INIS)

    Soria, C; Pontiga, F; Castellanos, A

    2004-01-01

    A complex plasma chemical and electrical model of a negative stationary wire-to-cylinder corona discharge in pure oxygen is presented. The corona discharge is assumed to have axial and azimuthal symmetry. The experimental current-voltage characteristic is required as input data, but there are no other adjustable or empirical parameters. The experimental validation of the results of the model comes from its prediction of the ozone concentration. The role played by different reactions and species is analysed in detail using the results of the simulation. The effect of the gas temperature and of the decomposition of ozone at the electrodes is also investigated. The agreement between the model and the experiments is excellent when the effect of ozone decomposition at the electrodes is taken into account

  20. Study of carbon dioxide gas treatment based on equations of kinetics in plasma discharge reactor

    Science.gov (United States)

    Abedi-Varaki, Mehdi

    2017-08-01

    Carbon dioxide (CO2) as the primary greenhouse gas, is the main pollutant that is warming earth. CO2 is widely emitted through the cars, planes, power plants and other human activities that involve the burning of fossil fuels (coal, natural gas and oil). Thus, there is a need to develop some method to reduce CO2 emission. To this end, this study investigates the behavior of CO2 in dielectric barrier discharge (DBD) plasma reactor. The behavior of different species and their reaction rates are studied using a zero-dimensional model based on equations of kinetics inside plasma reactor. The results show that the plasma reactor has an effective reduction on the CO2 density inside the reactor. As a result of reduction in the temporal variations of reaction rate, the speed of chemical reactions for CO2 decreases and very low concentration of CO2 molecules inside the plasma reactor is generated. The obtained results are compared with the existing experimental and simulation findings in the literature.

  1. Solar corona electron density distribution

    International Nuclear Information System (INIS)

    Esposito, P.B.; Edenhofer, P.; Lueneburg, E.

    1980-01-01

    Three and one-half months of single-frequency (f= 0 2.2 x 10 9 Hz) time delay data (earth-to-spacecraft and return signal travel time) were acquired from the Helios 2 spacecraft around the time of its solar occupation (May 16, 1976). Following the determination of the spacecraft trajectory the excess time delay due to the integrated effect of free electrons along the signal's ray path could be separated and modeled. An average solar corona, equatorial, electron density profile, during solar minimum, was deduced from time delay measurements acquired within 5--60 solar radii (R/sub S/) of the sun. As a point of reference, at 10 R/sub S/ from the sun we find an average electron density of 4500 el cm -3 . However, there appears to be an asymmtry in the electron density as the ray path moved from the west (preoccultation) to east (post-occulation) solar limb. This may be related to the fact that during entry into occulation the heliographic latitude of the ray path (at closes approach to the sun) was about 6 0 , whereas during exit it became -7 0 . The Helios electron density model is compared with similar models deduced from a variety of different experimental techniques. Within 5--20 R/sub S/ of the sun the models separate according to solar minimum or maximum conditions; however, anomalies are evident

  2. Production of nitrogen oxides in air pulse-periodic discharge with apokamp

    Science.gov (United States)

    Panarin, Victor A.; Skakun, Victor S.; Sosnin, Eduard A.; Tarasenko, Victor F.

    2018-05-01

    The decomposition products of pulse-periodic discharge atmospheric pressure plasma in apokamp, diffuse and corona modes were determined by optical and chemical methods. It is shown that apokamp discharge formation starts at a critical value of dissipation power in a discharge channel. Simultaneously, due to the thermochemical reactions, plasma starts to efficiently produce nitrogen oxides.

  3. Electric discharge synthesis of HCN in simulated Jovian atmospheres

    Science.gov (United States)

    Stribling, Roscoe; Miller, Stanley L.

    1987-01-01

    Corona discharge is presently considered as a possible source of the HCN detected in the Jovian atmosphere at 2.2 x 10 to the -7th moles/sq cm column density, for the cases of gas mixtures containing H2, CH4, and NH3, with H2/CH4 ratios from 4.4 to 1585. A 3:1 ratio of corona discharge to lightning energy similar to that of the earth is applied to Jupiter. Depending on the lightning energy available on Jupiter and the eddy diffusion coefficients in the synthesis region, HCN column densities generated by corona discharge could account for about 10 percent of the HCN observed.

  4. Nipple Discharge

    Science.gov (United States)

    ... any unexpected nipple discharge evaluated by a doctor. Nipple discharge in men under any circumstances could be a problem and needs further evaluation. One or both breasts may produce a nipple discharge, either spontaneously or when you squeeze your ...

  5. A thermal packed-bed reactor and a silent discharge plasma cell for a two-stage treatment system

    International Nuclear Information System (INIS)

    Godoy-Cabrera, O G; Lopez-Callejas, R; Mercado-Cabrera, A; Barocio, S R; Valencia, R; Munoz-Castro, A; Eguiluz, R Pena; Piedad-Beneitez, A de la

    2006-01-01

    Dielectric barrier discharge cells (DBDCs) have proved their efficiency in the generation of cold plasmas for hazardous organic compound degradation. Here, we describe the design and construction of a dual thermal packed-bed reactor and DBDC-based system to carry out the degradation of hazardous organic compounds in both liquid and gas phases. The main components of this system are: (i) the thermal treatment system (ii) DBDC and (iii) resonant inverters of low (3.3 kHz) and high (100 kHz) calculated frequencies. The definition of the cell physical parameters considers: (a) a first-order degradation ratio of the compound and (b) the air breakdown at atmospheric pressure as a function of the transport carrier gas. The power consumed by the cells during the discharges was computed theoretically and experimentally. Using the dual system along with a gas chromatography diagnostic system, highly efficient degradations of a test compound (benzene) have been obtained, reaching 99.950% in the case of a cell experimentally operated at 3.3 kHz and up to 99.996% in another one at 94.3 kHz. An additional 3.7 times reduction in the latter case residence time with respect to the low frequency cell has been found

  6. Potential of electrical gas discharges for pollution control of large gas volumes

    International Nuclear Information System (INIS)

    Kogelschatz, U.

    1997-01-01

    Non-equilibrium gas discharges in many cases offer an innovative approach to the solution cf industrial air pollution problems. Negative corona discharges are used in electrostatic precipitators to collect dust and fly ash particles. Pulsed positive streamer coronas, dielectric-barrier discharges and possibly also flow-stabilised high pressure glow discharges are emerging technologies for the destruction of air pollutants like nitrogen oxides and sulfur dioxide in flue gases and volatile organic compounds (VOCs) in industrial effluents. The different discharge types are discussed with special emphasis on their potential for upscaling. Major applications are expected particularly in the removal of dilute concentrations of air pollutants, in odour control and in the simultaneous removal of different pollutants. Dielectric-barrier discharges exhibit disposal efficiencies similar to those of pulsed positive streamer coronas and require less sophisticated feeding circuits in large-scale industrial applications. (author)

  7. Treatment of Candida albicans biofilms with low-temperature plasma induced by dielectric barrier discharge and atmospheric pressure plasma jet

    International Nuclear Information System (INIS)

    Koban, Ina; Welk, Alexander; Meisel, Peter; Holtfreter, Birte; Kocher, Thomas; Matthes, Rutger; Huebner, Nils-Olaf; Kramer, Axel; Sietmann, Rabea; Kindel, Eckhard; Weltmann, Klaus-Dieter

    2010-01-01

    Because of some disadvantages of chemical disinfection in dental practice (especially denture cleaning), we investigated the effects of physical methods on Candida albicans biofilms. For this purpose, the antifungal efficacy of three different low-temperature plasma devices (an atmospheric pressure plasma jet and two different dielectric barrier discharges (DBDs)) on Candida albicans biofilms grown on titanium discs in vitro was investigated. As positive treatment controls, we used 0.1% chlorhexidine digluconate (CHX) and 0.6% sodium hypochlorite (NaOCl). The corresponding gas streams without plasma ignition served as negative treatment controls. The efficacy of the plasma treatment was determined evaluating the number of colony-forming units (CFU) recovered from titanium discs. The plasma treatment reduced the CFU significantly compared to chemical disinfectants. While 10 min CHX or NaOCl exposure led to a CFU log 10 reduction factor of 1.5, the log 10 reduction factor of DBD plasma was up to 5. In conclusion, the use of low-temperature plasma is a promising physical alternative to chemical antiseptics for dental practice.

  8. Treatment of Candida albicans biofilms with low-temperature plasma induced by dielectric barrier discharge and atmospheric pressure plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Koban, Ina; Welk, Alexander; Meisel, Peter; Holtfreter, Birte; Kocher, Thomas [Unit of Periodontology, Dental School, University of Greifswald, Rotgerberstr. 8, 17475 Greifswald (Germany); Matthes, Rutger; Huebner, Nils-Olaf; Kramer, Axel [Institute for Hygiene and Environmental Medicine, University of Greifswald, Walther-Rathenau-Str. 49 a, 17487 Greifswald (Germany); Sietmann, Rabea [Institute of Microbiology, University of Greifswald, Friedrich-Ludwig-Jahn-Str. 15, 17487 Greifswald (Germany); Kindel, Eckhard; Weltmann, Klaus-Dieter, E-mail: ina.koban@uni-greifswald.d [Leibniz Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

    2010-07-15

    Because of some disadvantages of chemical disinfection in dental practice (especially denture cleaning), we investigated the effects of physical methods on Candida albicans biofilms. For this purpose, the antifungal efficacy of three different low-temperature plasma devices (an atmospheric pressure plasma jet and two different dielectric barrier discharges (DBDs)) on Candida albicans biofilms grown on titanium discs in vitro was investigated. As positive treatment controls, we used 0.1% chlorhexidine digluconate (CHX) and 0.6% sodium hypochlorite (NaOCl). The corresponding gas streams without plasma ignition served as negative treatment controls. The efficacy of the plasma treatment was determined evaluating the number of colony-forming units (CFU) recovered from titanium discs. The plasma treatment reduced the CFU significantly compared to chemical disinfectants. While 10 min CHX or NaOCl exposure led to a CFU log{sub 10} reduction factor of 1.5, the log{sub 10} reduction factor of DBD plasma was up to 5. In conclusion, the use of low-temperature plasma is a promising physical alternative to chemical antiseptics for dental practice.

  9. The influence of electrohydrodynamic flow on the distribution of chemical species in positive corona

    Science.gov (United States)

    Pontiga, Francisco; Yanallah, Khelifa; Bouazza, R.; Chen, Junhong

    2015-09-01

    A numerical simulation of positive corona discharge in air, including the effect of electrohydrodynamic (EHD) motion of the gas, has been carried out. Air flow is assumed to be confined between two parallel plates, and corona discharge is produced around a thin wire, midway between the plates. Therefore, fluid dynamics equations, including electrical forces, have been solved together with the continuity equation of each neutral species. The plasma chemical model included 24 chemical reactions and ten neutral species, in addition to electrons and positive ions. The results of the simulation have shown that the influence of EHD flow on the spatial distributions of the species is quite different depending on the species. Hence, reactive species like atomic oxygen and atomic nitrogen are confined to the vicinity of the wire, and they are weakly affected by the EHD gas motion. In contrast, nitrogen oxides and ozone are efficiently dragged outside the active region of the corona discharge by the EHD flow. This work was supported by the Spanish Government Agency ``Ministerio de Ciencia e Innovación'' under Contract No. FIS2011-25161.

  10. Corona-induced electrohydrodynamic instabilities in low conducting liquids

    Energy Technology Data Exchange (ETDEWEB)

    Vega, F.; Perez, A.T. [Depto. Electronica y Electromagnetismo, Facultad de Fisica, Universidad de Sevilla, Avda. Reina Mercedes, s/n. 41012, Sevilla (Spain)

    2003-06-01

    The rose-window electrohydrodynamic (EHD) instability has been observed when a perpendicular field with an additional unipolar ion injection is applied onto a low conducting liquid surface. This instability has a characteristic pattern with cells five to 10 times greater than those observed in volume instabilities caused by unipolar injection. We have used corona discharge from a metallic point to perform some measurements of the rose-window instability in low conducting liquids. The results are compared to the linear theoretical criterion for an ohmic liquid. They confirmed that the minimum voltage for this instability is much lower than that for the interfacial instability in high conducting liquids. This was predicted theoretically in the dependence of the critical voltage as a function of the non-dimensional conductivity. It is shown that in a non-ohmic liquid the rose window appears as a secondary instability after the volume instability. (orig.)

  11. Treatment of poly(ethylene terephthalate) foils by atmospheric pressure air dielectric barrier discharge and its influence on cell growth

    Science.gov (United States)

    Kuzminova, Anna; Vandrovcová, Marta; Shelemin, Artem; Kylián, Ondřej; Choukourov, Andrei; Hanuš, Jan; Bačáková, Lucie; Slavínská, Danka; Biederman, Hynek

    2015-12-01

    In this contribution an effect of dielectric barrier discharge (DBD) sustained in air at atmospheric pressure on surface properties of poly(ethylene terephthalate) (PET) foils is studied. It is found that exposure of PET to DBD plasma leads to rapid changes of surface chemical composition, wettability, surface morphology as well as mechanical properties of PET surface. In addition, based on biological tests that were performed using two cell types (Saos-2 human osteoblast-like cells and HUVEC human umbilical vein endothelial cells), it may be concluded that DBD plasma treatment positively influences cell growth on PET. This effect was found to be connected predominantly with increased surface energy and oxygen content of the surface of treated PET foils.

  12. Management and construction of a major zero discharge water supply and treatment scheme at Mount Piper Power Station, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Wong, P.; Docker, P.; Gabbrielli, E.; Wade, P. [Pacific Power, Sydney, NSW (Australia)

    1994-09-01

    Excellence in the organisation and management of a large multi-disciplinary design and construct project such as the zero discharge water supply and treatment scheme for Mount Piper coal-fired power station was essential to its successful execution. This paper discusses the management philosophies and strategies of Pacific Power and Transfield-PWT Asia/Pacific that resulted in this project being completed to the satisfaction of the client in the minimum time without delays and cost increases caused by interfaces between the parties. It highlights the advantages of contract packaging and placing the total responsibility for the performance and integration of a complex project system on one organisation. 2 refs., 6 figs.

  13. Method of removing uranium and its compounds from mine wastewaters and from aqueous solutions discharged in hydrometallurgical uranium ore treatment

    International Nuclear Information System (INIS)

    Jilek, R.; Prochazka, H.; Kuhr, I.; Fuska, J.; Nemec, P.; Katzer, J.

    1974-01-01

    The separation of uranium and its compounds from mine wastewaters and from water solutions discharged from uranium ore hydrometallurgical treatment, and its eventual simultaneous concentration in the biomass during uranium ore technological processing are described. The solutions are replenished with nutrients necessary for the growth of microorganisms, mainly with nitrogen, carbon and phosphorus and inoculated with fungi. During submersion cultivation, uranium incorporates in the mycelium, or is bound physico-chemically to the mycelium components. Together with these components, uranium is mechanically separated, i.e., by filtration, centrifugation or sedimentation. Organisms of the Fungi imperfecti class, mainly the Aspergillus and Penicillium genera are used for cultivation which may be continuous or semicontinuous. (B.S.)

  14. Mortality in COPD patients discharged from hospital: the role of treatment and co-morbidity

    Directory of Open Access Journals (Sweden)

    Nieminen Markku M

    2006-08-01

    Full Text Available Abstract Background The aim of this study was to analyse mortality and associated risk factors, with special emphasis on health status, medications and co-morbidity, in patients with chronic obstructive pulmonary disease (COPD that had been hospitalized for acute exacerbation. Methods This prospective study included 416 patients from each of the five Nordic countries that were followed for 24 months. The St. George's Respiratory Questionnaire (SGRQ was administered. Information on treatment and co-morbidity was obtained. Results During the follow-up 122 (29.3% of the 416 patients died. Patients with diabetes had an increased mortality rate [HR = 2.25 (1.28–3.95]. Other risk factors were advanced age, low FEV1 and lower health status. Patients treated with inhaled corticosteroids and/or long-acting beta-2-agonists had a lower risk of death than patients using neither of these types of treatment. Conclusion Mortality was high after COPD admission, with older age, decreased lung function, lower health status and diabetes the most important risk factors. Treatment with inhaled corticosteroids and long-acting bronchodilators may be associated with lower mortality in patients with COPD.

  15. Equitable Colorings Of Corona Multiproducts Of Graphs

    Directory of Open Access Journals (Sweden)

    Furmánczyk Hanna

    2017-11-01

    Full Text Available A graph is equitably k-colorable if its vertices can be partitioned into k independent sets in such a way that the numbers of vertices in any two sets differ by at most one. The smallest k for which such a coloring exists is known as the equitable chromatic number of G and denoted by =(G. It is known that the problem of computation of =(G is NP-hard in general and remains so for corona graphs. In this paper we consider the same model of coloring in the case of corona multiproducts of graphs. In particular, we obtain some results regarding the equitable chromatic number for the l-corona product G ◦l H, where G is an equitably 3- or 4-colorable graph and H is an r-partite graph, a cycle or a complete graph. Our proofs are mostly constructive in that they lead to polynomial algorithms for equitable coloring of such graph products provided that there is given an equitable coloring of G. Moreover, we confirm the Equitable Coloring Conjecture for corona products of such graphs. This paper extends the results from [H. Furmánczyk, K. Kaliraj, M. Kubale and V.J. Vivin, Equitable coloring of corona products of graphs, Adv. Appl. Discrete Math. 11 (2013 103–120].

  16. Treatment of poly(ethylene terephthalate) foils by atmospheric pressure air dielectric barrier discharge and its influence on cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Kuzminova, Anna [Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University, V Holešovickách 2, 180 00 Praha 8 (Czech Republic); Vandrovcová, Marta [Institute of Physiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague 4 (Czech Republic); Shelemin, Artem [Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University, V Holešovickách 2, 180 00 Praha 8 (Czech Republic); Kylián, Ondřej, E-mail: ondrej.kylian@gmail.com [Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University, V Holešovickách 2, 180 00 Praha 8 (Czech Republic); Choukourov, Andrei; Hanuš, Jan [Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University, V Holešovickách 2, 180 00 Praha 8 (Czech Republic); Bačáková, Lucie [Institute of Physiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague 4 (Czech Republic); Slavínská, Danka; Biederman, Hynek [Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University, V Holešovickách 2, 180 00 Praha 8 (Czech Republic)

    2015-12-01

    Highlights: • Effect of atmospheric pressure DBD plasma on PET foils was investigated. • DBD treatment causes increase in surface density of O-containing functional groups. • DBD plasma causes increase of wettability, roughness and complex modulus of PET. • DBD treatment positively influences cells growth on PET. • Enhancement of cell growth on treated PET depends on the cell type. - Abstract: In this contribution an effect of dielectric barrier discharge (DBD) sustained in air at atmospheric pressure on surface properties of poly(ethylene terephthalate) (PET) foils is studied. It is found that exposure of PET to DBD plasma leads to rapid changes of surface chemical composition, wettability, surface morphology as well as mechanical properties of PET surface. In addition, based on biological tests that were performed using two cell types (Saos-2 human osteoblast-like cells and HUVEC human umbilical vein endothelial cells), it may be concluded that DBD plasma treatment positively influences cell growth on PET. This effect was found to be connected predominantly with increased surface energy and oxygen content of the surface of treated PET foils.

  17. COMPOSITIONAL ANALYSIS OF THE SEWAGE INCOMING TO AND DISCHARGED FROM THE SEWAGE TREATMENT PLANT IN KOLBUSZOWA DOLNA

    Directory of Open Access Journals (Sweden)

    Krzysztof Chmielowski

    2016-11-01

    Full Text Available The paper presents the compositional analysis of sewage supplied to and discharged from the wastewater treatment plant in Kolbuszowa Dolna in the Subcarpathian region. The analysis was based on three basic indicators of sewage pollution (BOD5, CODCr, total suspended solids and two biogenic indicators (total nitrogen and total phosphorus. The composition of sewage was studied in the years 2010–2015. Basic descriptive statistics for the values of the analyzed indicators of sewage pollution were summarized and the obtained results were interpreted. The study showed that the sewage was susceptible to biological treatment. Descriptive statistics for the relationship between the following indicators were presented: CODCr/BOD5, BOD5/Ntot, BOD5/Ptot. The collected results indicate high variability of the composition of sewage entering the studied facility. The coefficients of variation for the values of basic indicators (BOD5, CODCr, total suspended solids in the raw sewage were similar and amounted to Wn = 0.45 while for total nitrogen it was Wn = 0.33 and for total phosphorus Wn = 0.40. The analysis of the collected material showed that sewage entering the treatment plant was readily biodegradable. On the other hand, the treated sewage was characterized by low values of the analyzed indicators, much below the permissible values provided by the water permit. The raw sewage was divided into five groups depending on the concentration of each pollution indicator. The number of raw sewage samples was determined for each group of the analyzed pollution indicator concentrations.

  18. Investigation of electric fields for low-temperature treatment of soils and liquids

    International Nuclear Information System (INIS)

    Heath, W.O.; Goheen, S.C.; Miller, M.C.; Richardson, R.L.

    1992-02-01

    Work was performed to assess the feasibility of an in situ technology for decomposing and removing hazardous organic waste compounds from soils. The technology is based on conductive soil heating and partial electrical discharges (corona) combined with soil-vapor extraction. A pilot-scale facility was developed and used to evaluate the ability to heat and dry soils using polyphase electricity applied through inserted pipes. Uniform heating (100 ± 2 degrees C) and drying to 1.2-wt % moisture were observed. Heating and resultant in situ steam formation have been demonstrated in previous studies to be effective in removing volatile and semivolatile compounds. Corona reactors were constructed to investigate decomposition of organic compounds by oxidants produced in a point-to-liquid corona discharge in ambient air at room temperature and pressure. Point-to-liquid corona was found to be capable of destroying a wide variety of organics, including three aromatics, two polyaromatics, a pcp, a pcb, an alkane, an alkene, an amide, a complexant, a chelator, and an organic dye. Tests with trichloroethylene demonstrated a decontamination factor of 2 x 10 5 (equal to a destruction efficiency of 99.999995%) and nearly complete (99.7%) mineralization, with the main byproduct being aqueous chloride ions. Real-time data on the decolorization kinetics of aqueous methylene blue were obtained using in situ probe colorimetry. Reaction rates were directly proportional to the amount of unreacted dye present and the square of electrode current. Other exploratory tests were performed to investigate concepts for generating ac corona discharges in soil and the ability of those discharges to decompose adsorbed organic compounds. All findings are discussed in relation to a conceptual soil-treatment scenario that includes a description of the basic hardware requirements

  19. Purulent vaginal discharge in grazing dairy cows: Risk factors, reproductive performance, and prostaglandin F2α treatment.

    Science.gov (United States)

    Giuliodori, M J; Magnasco, M; Magnasco, R P; Lacau-Mengido, I M; de la Sota, R L

    2017-05-01

    The objectives of this study were to assess the association of a 4-point scale of vaginal discharge score (VDS) with time to pregnancy to define criteria for a practical case of purulent vaginal discharge (PVD) in dairy cows, to test the risk factors for PVD, and, finally, the effect of a dose of PGF 2α on cure and reproductive performance. In experiment 1, grazing Holstein cows (n = 2,414) had their vaginal discharge scored at ∼32 d in milk (DIM) on a 4-point scale, the effect of VDS on the hazard of pregnancy by 300 DIM was then assessed to derive a case definition of PVD. Risk factors for PVD and self-cure were also assessed. In experiment 2, grazing Holstein cows (n = 6,326) from 5 herds were checked for PVD at ∼30 DIM. Cows with PVD were assigned to receive one dose of 500 μg of PGF 2α analog (Cloprostenol; Ciclase, Syntex SA, Buenos Aires, Argentina) per cow (odd ear tag number) or to remain untreated (even tag number). Cure was declared if cows presented clear normal vaginal discharge (VDS-0) at visit 2 (∼62 DIM). Data were analyzed with Cox's regression and mixed logistic models. In experiment 1, cows with VDS ≥1 had lower hazard of pregnancy and longer calving to pregnancy interval than cows with VDS-0. This finding was not affected by the time at which the diagnosis was performed. Therefore, a cow ≥21 DIM and having VDS ≥1 was used to define a case of PVD. The odds of PVD were greater in primiparous cows compared with multiparous, in cows with abnormal calving compared with those with normal calving, and in those losing BCS peripartum. In experiment 2, PGF 2α treatment tended to slightly increase the hazard of pregnancy (adjusted hazard ratio = 1.13). Conversely, PGF 2α had no effect on the odds of cure of PVD [adjusted odds ratio (AOR) = 1.19], pregnancy at first service (AOR = 1.03), or pregnancy by 100 DIM (AOR = 0.89) or 200 DIM (AOR = 1.27). In conclusion, cows with VDS ≥1 can be considered to have PVD because of their lower hazard

  20. TESIS experiment on study of solar corona in EUV spectral range (CORONAS-PHOTON project)

    International Nuclear Information System (INIS)

    Kuzin, S.V.; Zhitnik, I.A.; Ignat'ev, A.P.; Mitrofanov, A.V.; Pertsov, A.A.; Bugaenko, O.I.

    2005-01-01

    A new orbital station, namely: the CORONAS-PHOTON one (to be launched in 2006) equipped with systems to explore Sun at the intensification period of the solar activity 24-th cycle and at its peak is being designed within the framework of the CORONAS National Sun Space Exploration Program. The station equipment consists of systems to observe Sun within the spectral soft X-ray and vacuum ultraviolet bands. Paper lists and describes the TESIS experiment tools designed for the CORONAS-PHOTON Project to ensure the Sun atmospheric research within short-wave band [ru

  1. Potential of Micro Hydroelectric Generator Embedded at 30,000 PE Effluent Discharge of Sewerage Treatment Plant

    Science.gov (United States)

    Che Munaaim, M. A.; Razali, N.; Ayob, A.; Hamidin, N.; Othuman Mydin, M. A.

    2018-03-01

    A micro hydroelectric generator is an energy conversion approach to generate electricity from potential (motion) energy to an electrical energy. In this research, it is desired to be implemented by using a micro hydroelectric generator which is desired to be embedded at the continuous flow of effluent discharge point of domestic sewerage treatment plant (STP). This research evaluates the potential of electricity generation from micro hydroelectric generator attached to 30,000 PE sewerage treatment plant. The power output obtained from calculation of electrical power conversion is used to identify the possibility of this system and its ability to provide electrical energy, which can minimize the cost of electric bill especially for the pumping system. The overview of this system on the practical application with the consideration of payback period is summarized. The ultimate aim of the whole application is to have a self-ecosystem electrical power generated for the internal use of STP by using its own flowing water in supporting the sustainable engineering towards renewable energy and energy efficient approach. The results shows that the output power obtained is lower than expected output power (12 kW) and fall beyond of the range of a micro hydro power (5kW - 100kW) since it is only generating 1.58 kW energy by calculation. It is also observed that the estimated payback period is longer which i.e 7 years to recoup the return of investment. A range of head from 4.5 m and above for the case where the flow shall at least have maintained at 0.05 m3/s in the selected plant in order to achieved a feasible power output. In conclusion, wastewater treatment process involves the flowing water (potential energy) especially at the effluent discharge point of STP is possibly harvested for electricity generation by embedding the micro hydroelectric generator. However, the selection of STP needs to have minimum 4.5 meter head with 0.05 m3/s of continuously flowing water to make

  2. Potential of Micro Hydroelectric Generator Embedded at 30,000 PE Effluent Discharge of Sewerage Treatment Plant

    Directory of Open Access Journals (Sweden)

    Che Munaaim M.A.

    2018-01-01

    Full Text Available A micro hydroelectric generator is an energy conversion approach to generate electricity from potential (motion energy to an electrical energy. In this research, it is desired to be implemented by using a micro hydroelectric generator which is desired to be embedded at the continuous flow of effluent discharge point of domestic sewerage treatment plant (STP. This research evaluates the potential of electricity generation from micro hydroelectric generator attached to 30,000 PE sewerage treatment plant. The power output obtained from calculation of electrical power conversion is used to identify the possibility of this system and its ability to provide electrical energy, which can minimize the cost of electric bill especially for the pumping system. The overview of this system on the practical application with the consideration of payback period is summarized. The ultimate aim of the whole application is to have a self-ecosystem electrical power generated for the internal use of STP by using its own flowing water in supporting the sustainable engineering towards renewable energy and energy efficient approach. The results shows that the output power obtained is lower than expected output power (12 kW and fall beyond of the range of a micro hydro power (5kW - 100kW since it is only generating 1.58 kW energy by calculation. It is also observed that the estimated payback period is longer which i.e 7 years to recoup the return of investment. A range of head from 4.5 m and above for the case where the flow shall at least have maintained at 0.05 m3/s in the selected plant in order to achieved a feasible power output. In conclusion, wastewater treatment process involves the flowing water (potential energy especially at the effluent discharge point of STP is possibly harvested for electricity generation by embedding the micro hydroelectric generator. However, the selection of STP needs to have minimum 4.5 meter head with 0.05 m3/s of continuously flowing

  3. Probabilistic environmental risk characterization of pharmaceuticals in sewage treatment plant discharges.

    Science.gov (United States)

    Christensen, Anne Munch; Markussen, Bo; Baun, Anders; Halling-Sørensen, Bent

    2009-10-01

    The occurrence of pharmaceuticals in different water bodies and the findings of effects on aquatic organisms in ecotoxicity tests have raised concerns about environmental risks of pharmaceuticals in receiving waters. Due to the fact that the amount of ecotoxicological studies has increased significantly during the last decade, probabilistic approaches for risk characterization of these compounds may be feasible. This approach was evaluated by applying it to 22 human-used pharmaceuticals covering both pharmaceuticals with a high volume and high ecotoxicity, using ecotoxicological effect data from laboratory studies and comparing these to monitoring data on the effluents from sewage treatment plants in Europe and pharmaceutical sales quantities. We found that for 19 of the 22 selected pharmaceuticals the existing data were sufficient for probabilistic risk characterizations. The subsequently modeled ratios between monitored concentrations and low-effect concentrations were mostly above a factor of 100. Compared to the current paradigm for EU environmental risk assessment where a safety factor of 10 or 100 might have been used it seems that for the modeled compounds there's a low environmental risk. However, similarly calculated ratios for five pharmaceuticals (propranolol, ibuprofen, furosemide, ofloxacin, and ciprofloxacin) were below 100, while ibuprofen and ciprofloxacin are considered to be of high concern due to lack of ecotoxicity studies. This paper shows that by applying probabilistic approaches, existing data can be used to execute a comprehensive study on probability of impacts, thereby contributing to a more comprehensive environmental risk assessment of pharmaceuticals.

  4. Bioaugmentation: An Emerging Strategy of Industrial Wastewater Treatment for Reuse and Discharge

    Directory of Open Access Journals (Sweden)

    Alexis Nzila

    2016-08-01

    Full Text Available A promising long-term and sustainable solution to the growing scarcity of water worldwide is to recycle and reuse wastewater. In wastewater treatment plants, the biodegradation of contaminants or pollutants by harnessing microorganisms present in activated sludge is one of the most important strategies to remove organic contaminants from wastewater. However, this approach has limitations because many pollutants are not efficiently eliminated. To counterbalance the limitations, bioaugmentation has been developed and consists of adding specific and efficient pollutant-biodegrading microorganisms into a microbial community in an effort to enhance the ability of this microbial community to biodegrade contaminants. This approach has been tested for wastewater cleaning with encouraging results, but failure has also been reported, especially during scale-up. In this review, work on the bioaugmentation in the context of removal of important pollutants from industrial wastewater is summarized, with an emphasis on recalcitrant compounds, and strategies that can be used to improve the efficiency of bioaugmentation are also discussed. This review also initiates a discussion regarding new research areas, such as nanotechnology and quorum sensing, that should be investigated to improve the efficiency of wastewater bioaugmentation.

  5. Evaluation of surface water treatment and discharge options for the Weldon Spring Site Remedial Action Project

    International Nuclear Information System (INIS)

    Goyette, M.L.; MacDonell, M.M.

    1992-01-01

    The US Department of Energy (DOE), under its Environmental Restoration and Waste Management Program, is responsible for conducting response actions at the Weldon Spring site in St. Charles County, Missouri. The site consists of two noncontiguous areas: (1) the chemical plant area, which includes four raffinate pits and two small ponds, and (2) a 3.6-ha (9-acre) quarry located about 6.4 km (4 mi) southwest of the chemical plant area. Both of these areas became chemically and radioactively contaminated as a result of processing and disposal activities that took place from the 1940s through 1960s. The Weldon Spring site, located about 48 km (30 mi) west of St. Louis, is listed on the National Priorities List of the US Environmental Protection Agency. Nitroaromatic explosives were processed by the Army at the chemical plant area during the 1940s, and radioactive materials were processed by DOE's predecessor agency (the Atomic Energy Commission) during the 1950s and 1960s. Overall remediation of the Weldon Spring site is being addressed through the Weldon Spring Site Remedial Action Project, and it consists of several components. One component is the management of radioactively and chemically contaminated surface water impoundments at the chemical plant area -- i.e., the four raffinate pits, Frog Pond, and Ash Pond which was addressed under a separate action and documented in an engineering evaluation/cost analysis report. This report discusses the evaluation of surface water treatment at the Weldon Spring site

  6. Water treatments in semi-closed cooling circuits and their impact on the quality of effluents discharged by CERN

    CERN Document Server

    Santos Leite Cima Gomes, J; Kleiner, S

    2008-01-01

    The main goal of this study is to assess the impact of the discharges of the semi-closed water cooling circuits of CERN (European Center for Nuclear Research) on the overall quality of CERN's effluents, taking as guidelines the international legislation supported on the knowledge of the water systems of CERN. In order to reach this goal, a thorough analysis of the functioning of the semi-closed water cooling systems of CERN's particle accelerators was done, as well as, an analysis of the treatment that is done to prevent the proliferation of bacteria such as Legionella. The products used in these water treatments, as well as their impact, were also researched. In addition, a study of the applicable regulation to CERN's effluent was done. This study considered not only the regulation of France and Switzerland (CERN's host states) but also the international regulation from the European community, Portugal Germany, Spain, U.S. and Canada, having in view a better understanding of the limit values of the parameter...

  7. Selective Grafting of Primary Amines onto Carbon Nanotubes via Free-Radical Treatment in Microwave Plasma Post-Discharge

    Directory of Open Access Journals (Sweden)

    Philippe Dubois

    2012-01-01

    Full Text Available A novel strategy to graft functional groups at the surface of carbon nanotubes (CNTs is discussed. Aiming at grafting nitrogen containing groups, and more specifically primary amine covalent functionalization, CNTs were exposed under atomic nitrogen flow arising from an Ar + N2 microwave plasma. The primary amine functions were identified and quantified through chemical derivatization with 4-(trifluoromethylbenzaldehyde and characterized through X-ray photoelectron spectroscopy. The increase of the selectivity in the primary amines grafting onto CNTs, up to 66.7% for treatment of CNT powder, was performed via the reduction of post-treatment oxygen contamination and the addition of hydrogen in the experimental set-up, more particularly in the plasma post-discharge chamber. The analyses of nitrogenated and primary amine functions grafting on the CNT surface suggest that atomic nitrogen (N• and reduced nitrogen species (NH• and NH2• react preferentially with defect sites of CNTs and, then, only atomic nitrogen continues to react on the CNT surface, creating defects.

  8. Pulsed corona demonstrator for semi-industrial scale air purification

    NARCIS (Netherlands)

    Beckers, F.J.C.M.; Hoeben, W.F.L.M.; Huiskamp, T.; Pemen, A.J.M.; Heesch, van E.J.M.

    2013-01-01

    Although pulsed corona technology for air purification is widely investigated by the lab experiments, large-scale application has yet to be proven. Industrial systems require large flow handling and thus, high corona power. An autonomous semi-industrial scale pilot wire-cylinder type corona reactor

  9. Sterilization and Decontamination of Surfaces Contaminated With Biological and Chemical Warfare Agents Using Atmospheric Pressure Plasma Discharges

    National Research Council Canada - National Science Library

    Garate, Eusebio

    1999-01-01

    ... based on the application of an atmospheric pressure plasma. We used both a DC corona and dielectric barrier discharge for the sterilization tests which were conducted on a variety of substrates including metals and chemically resistant fabrics...

  10. On ion-cyclotron-resonance heating of the corona and solar wind

    Directory of Open Access Journals (Sweden)

    E. Marsch

    2003-01-01

    Full Text Available This paper concisely summarizes and critically reviews recent work by the authors on models of the heating of the solar corona by resonance of ions with high-frequency waves (up to the proton cyclotron frequency. The quasi-linear theory of pitch angle diffusion is presented in connection with relevant solar wind proton observations. Hybrid fluid-kinetic model equations, which include wave-particle interactions and collisions, are derived. Numerical solutions are discussed, representative of the inner corona and near-Sun solar wind. A semi-kinetic model for reduced velocity distributions is presented, yielding kinetic results for heavy ions in the solar corona. It is concluded that a self-consistent treatment of particle distributions and wave spectra is required, in order to adequately describe coronal physics and to obtain agreement with observations.

  11. Shoulder replacement - discharge

    Science.gov (United States)

    Total shoulder arthroplasty - discharge; Endoprosthetic shoulder replacement - discharge; Partial shoulder replacement - discharge; Partial shoulder arthroplasty - discharge; Replacement - shoulder - discharge; Arthroplasty - shoulder - discharge

  12. Measurement and analysis of time-domain characteristics of corona-generated radio interference from a single positive corona source

    Science.gov (United States)

    Li, Xuebao; Li, Dayong; Chen, Bo; Cui, Xiang; Lu, Tiebing; Li, Yinfei

    2018-04-01

    The corona-generated electromagnetic interference commonly known as radio interference (RI) has become a limiting factor for the design of high voltage direct current transmission lines. In this paper, a time-domain measurement system is developed to measure the time-domain characteristics of corona-generated RI from a single corona source under a positive corona source. In the experiments, the corona current pulses are synchronously measured through coupling capacitors. The one-to-one relationship between the corona current pulse and measured RI voltage pulse is observed. The statistical characteristics of pulse parameters are analyzed, and the correlations between the corona current pulse and RI voltage pulse in the time-domain and frequency-domain are analyzed. Depending on the measured corona current pulses, the time-domain waveform of corona-generated RI is calculated on the basis of the propagation model of corona current on the conductor, the dipolar model for electric field calculation, and the antenna model for inducing voltage calculation. The well matched results between measured and simulated waveforms of RI voltage can show the validity of the measurement and calculation method presented in this paper, which also further show the close correlation between corona current and corona-generated RI.

  13. Nanoflare heating model for collisionless solar corona

    Indian Academy of Sciences (India)

    Magnetic reconnection plays a significant role in heating the solar corona. When two oppositely directed magnetic fields come closer to form a current sheet, the current density of the plasma increases due to which magnetic reconnection and conversion of magnetic energy into thermal energy takes place. The present ...

  14. Novel modulator topology for corona plasma generation

    NARCIS (Netherlands)

    Ariaans, T.H.P.; Pemen, A.J.M.; Winands, G.J.J.; Liu, Z.; Heesch, van E.J.M.

    2009-01-01

    Gas cleaning using plasma technology is slowly introduced into industry nowadays. Several challenges still have to be overcome: increasing the scale, safety, life time and reducing costs. In 2006 we demonstrated a 20 kW nanosecond pulsed corona system. The electrical efficiency was > 90%. O-radical

  15. Protein corona: a new approach for nanomedicine design

    Directory of Open Access Journals (Sweden)

    Nguyen VH

    2017-04-01

    Full Text Available Van Hong Nguyen, Beom-Jin Lee Department of Pharmacy, Bioavailability Control Laboratory, College of Pharmacy, Ajou University, Suwon, Republic of Korea Abstract: After administration of nanoparticle (NP into biological fluids, an NP–protein complex is formed, which represents the “true identity” of NP in our body. Hence, protein–NP interaction should be carefully investigated to predict and control the fate of NPs or drug-loaded NPs, including systemic circulation, biodistribution, and bioavailability. In this review, we mainly focus on the formation of protein corona and its potential applications in pharmaceutical sciences such as prediction modeling based on NP-adsorbed proteins, usage of active proteins for modifying NP to achieve toxicity reduction, circulation time enhancement, and targeting effect. Validated correlative models for NP biological responses mainly based on protein corona fingerprints of NPs are more highly accurate than the models solely set up from NP properties. Based on these models, effectiveness as well as the toxicity of NPs can be predicted without in vivo tests, while novel cell receptors could be identified from prominent proteins which play important key roles in the models. The ungoverned protein adsorption onto NPs may have generally negative effects such as rapid clearance from the bloodstream, hindrance of targeting capacity, and induction of toxicity. In contrast, controlling protein adsorption by modifying NPs with diverse functional proteins or tailoring appropriate NPs which favor selective endogenous peptides and proteins will bring promising therapeutic benefits in drug delivery and targeted cancer treatment. Keywords: protein-nanoparticle interaction, protein corona, exchange of adsorbed protein, toxicity reduction, predictive modeling, targeting drug delivery

  16. Anaerobic treatment for C and S removal in 'zero-discharge' paper mills: effects of process design on S removal efficiencies.

    NARCIS (Netherlands)

    Lier, van J.B.; Lens, P.N.L.; Hulshoff Pol, L.W.

    2001-01-01

    Stringent environmental laws in Europe and Northern America lead to the development towards closure of the process water streams in pulp and paper mills. Application of a "zero-discharge" process is already a feasible option for the board and packaging paper industry, provided in-line treatment is

  17. Low Pressure DC Glow Discharge Air Plasma Surface Treatment of Polyethylene (PE) Film for Improvement of Adhesive Properties

    International Nuclear Information System (INIS)

    Pandiyaraj, Krishnasamy Navaneetha; Yoganand, Paramasivam; Selvarajan, Vengatasamy; Deshmukh, Rajendrasing R.; Balasubramanian, Suresh; Maruthamuthu, Sundaram

    2013-01-01

    The present work deals with the change in surface properties of polyethylene (PE) film using DC low pressure glow discharge air plasma and makes it useful for technical applications. The change in hydrophilicity of the modified PE film surface was investigated by measuring contact angle and surface energy as a function of exposure time. Changes in the morphological and chemical composition of PE films were analyzed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The improvement in adhesion was studied by measuring T-peel and lap-shear strength. The results show that the wettability and surface energy of the PE film has been improved due to the introduction of oxygen-containing polar groups and an increase in surface roughness. The XPS result clearly shows the increase in concentration of oxygen content and the formation of polar groups on the polymer surface. The AFM observation on PE film shows that the roughness of the surface increased due to plasma treatment. The above morphological and chemical changes enhanced the adhesive properties of the PE film surfaces, which was confirmed by T-peel and lap-shear tests.

  18. Fear of food prospectively predicts drive for thinness in an eating disorder sample recently discharged from intensive treatment.

    Science.gov (United States)

    Levinson, Cheri A; Brosof, Leigh C; Ma, Jackie; Fewell, Laura; Lenze, Eric J

    2017-12-01

    Fears of food are common in individuals with eating disorders and contribute to the high relapse rates. However, it is unknown how fears of food contribute to eating disorder symptoms across time, potentially contributing to an increased likelihood of relapse. Participants diagnosed with an eating disorder (N=168) who had recently completed intensive treatment were assessed after discharge and one month later regarding fear of food, eating disorder symptoms, anxiety sensitivity, and negative affect. Cross lagged path analysis was utilized to determine if fear of food predicted subsequent eating disorder symptoms one month later. Fear of food-specifically, anxiety about eating and feared concerns about eating-predicted drive for thinness, a core symptom domain of eating disorders. These relationships held while accounting for anxiety sensitivity and negative affect. There is a specific, direct relationship between anxiety about eating and feared concerns about eating and drive for thinness. Future research should test if interventions designed to target fear of food can decrease drive for thinness and thereby prevent relapse. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Photo-triggering and secondary electron produced ionization in electric discharge ArF* excimer lasers

    Science.gov (United States)

    Xiong, Zhongmin; Kushner, Mark J.

    2011-10-01

    Electric discharge excimer lasers are sustained in multi-atmosphere attaching gas mixtures that are typically preionized to enable a reproducible, uniform glow, which maximizes optical quality and gain. This preionization is often accomplished using UV light produced by a corona discharge within the plasma cavity. To quantify the relationship between corona discharge properties and those of the laser discharge, the triggering of electron avalanche by preionizing UV light in an electric discharge-pumped ArF* excimer laser was numerically investigated using a two-dimensional model. The preionizing UV fluxes were generated by a corona-bar discharge driven by the same voltage pulse as the main discharge sustained in a multi-atmospheric Ne/Ar/Xe/F2 gas mixture. The resulting peak photo-electron density in the inter-electrode spacing is around 108 cm-3, and its distribution is biased toward the UV source. The preionization density increases with increasing dielectric constant and capacitance of the corona bar. The symmetry and uniformity of the discharge are, however, improved significantly once the main avalanche develops. In addition to bulk electron impact ionization, the ionization generated by sheath accelerated secondary electrons was found to be important in sustaining the discharge current at experimentally observed values. At peak current, the magnitude of the ionization by sheath accelerated electrons is comparable to that from bulk electron impact in the vicinity of the cathode.

  20. Attaining 2D Black Phosphorus and Investigations into Floating-Electrode Dielectric Barrier Discharge Treatment of Solutions

    Science.gov (United States)

    Smith, Joshua Benjamin

    -ray diffraction, transmission electron microscopy, and Raman spectroscopy have confirmed successful growth of 2D black phosphorus from red phosphorus thin films for potential uses in 2D semiconductor applications. Additionally, this work discusses some of the chemistry occurring in solution as a result of nonthermal plasma treatment from a floating-electrode dielectric barrier discharge (FE-DBD) configuration. Nonthermal plasma generation allows for the treatment of heat sensitive materials. This has opened up the field to numerous clinical applications of nonthermal plasma treatment including sterilization and wound healing along with potentials in dentistry, dermatology, and even food industries. FE-DBD plasma treatment of water was found to provide a wide-range antimicrobial solution that remained active following 2 years of aging. This plasma-treated water was found to generate a number of ROS/RNS and the formation of these components was studied and verified with UV/Vis and ESR spectroscopy. Enhanced effects were observed when cell culture medium was plasma treated, suggesting the formation of additional reactive species from the plasma treatment of a variety of biomolecules. It is essential to understand these effects for a number of reasons. The possibility to generate a wide range of antimicrobial solutions from air, water, and basic biomolecules could provide a solution for those bacteria that have developed antibiotic resistances. Simultaneously, information into the reaction mechanisms of this FE-DBD plasma treatment can be investigated. All of the applications mentioned above involve complex networks of basic biomolecules, from skin tissue to bacteria cell walls. This work analyzes the effects of plasma treatment on several biomolecule solutions and simultaneously takes aim at understanding some of the potential mechanisms of plasma treatment. Studies were carried out using NMR and GC/MS. This information was used to investigate the possible targeted areas for FE

  1. Thermal acclimation and thyroxine treatment modify the electric organ discharge frequency in an electric fish, Apteronotus leptorhynchus.

    Science.gov (United States)

    Dunlap, K D; Ragazzi, M A

    2015-11-01

    In ectotherms, the rate of many neural processes is determined externally, by the influence of the thermal environment on body temperature, and internally, by hormones secreted from the thyroid gland. Through thermal acclimation, animals can buffer the influence of the thermal environment by adjusting their physiology to stabilize certain processes in the face of environmental temperature change. The electric organ discharge (EOD) used by weak electric fish for electrocommunication and electrolocation is highly temperature sensitive. In some temperate species that naturally experience large seasonal fluctuations in environmental temperature, the thermal sensitivity (Q10) of the EOD shifts after long-term temperature change. We examined thermal acclimation of EOD frequency in a tropical electric fish, Apteronotus leptorhynchus that naturally experiences much less temperature change. We transferred fish between thermal environments (25.3 and 27.8 °C) and measured EOD frequency and its thermal sensitivity (Q10) over 11 d. After 6d, fish exhibited thermal acclimation to both warming and cooling, adjusting the thermal dependence of EOD frequency to partially compensate for the small change (2.5 °C) in water temperature. In addition, we evaluated the thyroid influence on EOD frequency by treating fish with thyroxine or the anti-thyroid compound propylthiouricil (PTU) to stimulate or inhibit thyroid activity, respectively. Thyroxine treatment significantly increased EOD frequency, but PTU had no effect. Neither thyroxine nor PTU treatment influenced the thermal sensitivity (Q10) of EOD frequency during acute temperature change. Thus, the EOD of Apteronotus shows significant thermal acclimation and responds to elevated thyroxine. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Comments on the 'minimum flux corona' concept

    International Nuclear Information System (INIS)

    Antiochos, S.K.; Underwood, J.H.

    1978-01-01

    Hearn's (1975) models of the energy balance and mass loss of stellar coronae, based on a 'minimum flux corona' concept, are critically examined. First, it is shown that the neglect of the relevant length scales for coronal temperature variation leads to an inconsistent computation of the total energy flux F. The stability arguments upon which the minimum flux concept is based are shown to be fallacious. Errors in the computation of the stellar wind contribution to the energy budget are identified. Finally we criticize Hearn's (1977) suggestion that the model, with a value of the thermal conductivity modified by the magnetic field, can explain the difference between solar coronal holes and quiet coronal regions. (orig.) 891 WL [de

  3. MASC: Magnetic Activity of the Solar Corona

    Science.gov (United States)

    Auchere, Frederic; Fineschi, Silvano; Gan, Weiqun; Peter, Hardi; Vial, Jean-Claude; Zhukov, Andrei; Parenti, Susanna; Li, Hui; Romoli, Marco

    We present MASC, an innovative payload designed to explore the magnetic activity of the solar corona. It is composed of three complementary instruments: a Hard-X-ray spectrometer, a UV / EUV imager, and a Visible Light / UV polarimetric coronagraph able to measure the coronal magnetic field. The solar corona is structured in magnetically closed and open structures from which slow and fast solar winds are respectively released. In spite of much progress brought by two decades of almost uninterrupted observations from several space missions, the sources and acceleration mechanisms of both types are still not understood. This continuous expansion of the solar atmosphere is disturbed by sporadic but frequent and violent events. Coronal mass ejections (CMEs) are large-scale massive eruptions of magnetic structures out of the corona, while solar flares trace the sudden heating of coronal plasma and the acceleration of electrons and ions to high, sometimes relativistic, energies. Both phenomena are most probably driven by instabilities of the magnetic field in the corona. The relations between flares and CMEs are still not understood in terms of initiation and energy partition between large-scale motions, small-scale heating and particle acceleration. The initiation is probably related to magnetic reconnection which itself results magnetic topological changes due to e.g. flux emergence, footpoints motions, etc. Acceleration and heating are also strongly coupled since the atmospheric heating is thought to result from the impact of accelerated particles. The measurement of both physical processes and their outputs is consequently of major importance. However, despite its fundamental importance as a driver for the physics of the Sun and of the heliosphere, the magnetic field of our star’s outer atmosphere remains poorly understood. This is due in large part to the fact that the magnetic field is a very difficult quantity to measure. Our knowledge of its strength and

  4. Comparison of pulsed corona plasma and pulsed electric fields for the decontamination of water containing Legionella pneumophila as model organism.

    Science.gov (United States)

    Banaschik, Robert; Burchhardt, Gerhard; Zocher, Katja; Hammerschmidt, Sven; Kolb, Juergen F; Weltmann, Klaus-Dieter

    2016-12-01

    Pulsed corona plasma and pulsed electric fields were assessed for their capacity to kill Legionella pneumophila in water. Electrical parameters such as in particular dissipated energy were equal for both treatments. This was accomplished by changing the polarity of the applied high voltage pulses in a coaxial electrode geometry resulting in the generation of corona plasma or an electric field. For corona plasma, generated by high voltage pulses with peak voltages of +80kV, Legionella were completely killed, corresponding to a log-reduction of 5.4 (CFU/ml) after a treatment time of 12.5min. For the application of pulsed electric fields from peak voltages of -80kV a survival of log 2.54 (CFU/ml) was still detectable after this treatment time. Scanning electron microscopy images of L. pneumophila showed rupture of cells after plasma treatment. In contrast, the morphology of bacteria seems to be intact after application of pulsed electric fields. The more efficient killing for the same energy input observed for pulsed corona plasma is likely due to induced chemical processes and the generation of reactive species as indicated by the evolution of hydrogen peroxide. This suggests that the higher efficacy and efficiency of pulsed corona plasma is primarily associated with the combined effect of the applied electric fields and the promoted reaction chemistry. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Testing of man-made overland-flow and wetlands systems for the treatment of discharged waters from oil and gas production operations in Wyoming

    International Nuclear Information System (INIS)

    Caswell, P.C.; Gelb, D.; Marinello, S.A.; Emerick, J.C.; Cohen, R.R.H.

    1992-01-01

    The quality of produced and discharged waters is of increasing concern as the overall quality of potable waters within many regions of the country becomes a critical issue. The impact of discharged waters on the downstream water quality, as well as the flora and fauna within a discharge zone, is dependent on the quality of the water ultimately released into the system. In many regions of the country, discharge permits are being re-evaluated and sometimes recalled due to the actual and perceived impact upon surface and subsurface waters, particularly those providing water utilized by the human population. The engineering, design and testing of a system to treat produced waters from oil operations in Wyoming is addressed in this study. This work was designed and performed by students and faculty in the Environmental Science and Engineering and Petroleum Engineering departments at the Colorado School of Mines. The system consists of overland flow units and a constructed wetlands unit. The system units can be independently evaluated. The water is drawn from active settling ponds above the test site. Produced waters are actively being discharged into the drainage basin. Waters flowing through the test units are likewise discharged after treatment. The system has been operational since June, 1991 and monthly sampling and testing will continue through March, 1992. Initial results having been very promising. Aeration, precipitation and bacterial activity in the overland flow and wetland units appears to nearly eliminate the sulfide problem present and significantly reduce the released radium concentration. These are the constituents of major concern although testing for other chemicals of concern, including hydrocarbon content is also analyzed

  6. Operating household wastewater treatment plants in the light of binding quality standards for wastewater discharged to water bodies or to soil

    Directory of Open Access Journals (Sweden)

    Jawecki Bartosz

    2017-03-01

    Full Text Available The study presents the legal requirements concerning the quality of wastewater discharged to waterbodies and to soil after treatment in household wastewater treatment plants located in agglomerations or outside them. The procedure of stopping the operation of a household treatment plant that doesn’t meet the statutory wastewater treatment efficiency was presented. The decision ordering to stop the use of a household wastewater treatment plant has to be preceded by a decision ordering to take measures to limit its adverse impact on the environment. The clarification procedure has to determine the adverse impact on the environment in a doubtless manner and it has to be reflected in the documentation. The assessment of adverse impact should take into account the binding standards of use of the environment. Stopping the operation of a household wastewater treatment plant may result in issuing a decision ordering the user to connect to the sanitary sewage system.

  7. Influence of argon/oxygen atmospheric dielectric barrier discharge treatment on desizing and scouring of poly (vinyl alcohol) on cotton fabrics

    International Nuclear Information System (INIS)

    Peng Shujing; Gao Zhiqiang; Sun Jie; Yao Lan; Qiu Yiping

    2009-01-01

    The effect of argon/oxygen atmospheric dielectric barrier discharge (DBD) treatment on desizing and scouring of polyvinyl alcohol (PVA) on cotton fabric was studied with respect to the treatment duration of 1, 2, 4 and 6 min. X-ray photoelectron spectroscopy (XPS) analysis indicated that oxygen concentration increased for the plasma treated PVA film. Solubility measurement revealed that plasma treatment increased PVA solubility in hot washing but less effective in cold washing. Scanning electron microscopy (SEM) showed that the fiber surfaces were as clean as unsized fibers after 6 min treatment followed by hot washing. Wickability analysis indicated that the capillary heights of plasma treated fabrics increased significantly as the plasma treatment duration increased. The results of the yarn tensile strength test showed that the plasma treatment did not have a negative effect on fabric tensile strength.

  8. NIPPLE DISCHARGE

    Directory of Open Access Journals (Sweden)

    T. N. Bukharova

    2008-01-01

    Full Text Available According to the data available in the literature, as high as 50% of women have benign breast tumors frequently accompanied by nip- ple discharge. Nipple discharge may be serous, bloody, purulent, and colostric. The most common causes are breast abscess, injury, drugs, prolactinoma, intraductal pappiloma, ductal ectasia, intraductal cancer (not more than 10%.

  9. Determination of the Corona model parameters with artificial neural networks

    International Nuclear Information System (INIS)

    Ahmet, Nayir; Bekir, Karlik; Arif, Hashimov

    2005-01-01

    Full text : The aim of this study is to calculate new model parameters taking into account the corona of electrical transmission line wires. For this purpose, a neural network modeling proposed for the corona frequent characteristics modeling. Then this model was compared with the other model developed at the Polytechnic Institute of Saint Petersburg. The results of development of the specified corona model for calculation of its influence on the wave processes in multi-wires line and determination of its parameters are submitted. Results of obtained calculation equations are brought for electrical transmission line with allowance for superficial effect in the ground and wires with reference to developed corona model

  10. Basic principles and applications of atmospheric-pressure discharge plasmas

    International Nuclear Information System (INIS)

    Becker, K.H.

    2002-01-01

    The principles that govern the generation and maintenance of atmospheric - pressure discharge plasmas are summarized. The properties and operating parameters of various types such as dielectric barrier discharge plasmas (DBDs), corona discharge plasmas (CDs), microhollow cathode discharge plasmas (MHCDs) , and dielectric capillary electrode discharge plasmas (CDEDs) are introduced. All of them are self sustained, non equilibrium gas discharges that can be operated at atmospheric pressure. CDs and DBDDs represent very similar types of discharges, while DBDs are characterized by insulating layers on one or both electrodes, CDs depend on inhomogeneous electric fields at least in some parts of the electrode configuration to restrict the primary ionization processes to a small fraction of the inter - electrode region. Their application to novel light sources in the ultraviolet (UV) and vacuum ultraviolet (VUV) spectral region is described. (nevyjel)

  11. Optical signatures of discharges in parallel coupled DC accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, Rehim N.; Banerjee, Srutarshi; Acharya, S.N., E-mail: rehim@barc.gov.in [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Mumbai (India); and others

    2014-07-01

    Parallel coupled voltage multiplier based accelerator topologies offer advantages of better regulation and ripple compared to their series coupled counterparts for Industrial electron beam accelerators. During conditioning and operation these systems undergoes various types of electrical discharges. The discharge can be a direct spark over from the high voltage terminal to ground through SF{sub 6} insulation, vacuum breakdown in the accelerating tube maintained in the order of 10{sup -7} mbar pressure, or local discharge between corona guards which are used to couple RF power to the multiplier. There could be discharges in between dynodes of the accelerating tube. As the inter electrode discharges do not reflect in load current, detection of these conditions becomes very difficult. Optical discharge detection methods can be used effectively in this situation. Photo multiplier based optical discharge detection has been deployed in a 3 MeV DC accelerator. Characteristics of the optical signal received during conditioning phase have been presented in this paper. (author)

  12. Large-scale volcanism associated with coronae on Venus

    Science.gov (United States)

    Roberts, K. Magee; Head, James W.

    1993-01-01

    The formation and evolution of coronae on Venus are thought to be the result of mantle upwellings against the crust and lithosphere and subsequent gravitational relaxation. A variety of other features on Venus have been linked to processes associated with mantle upwelling, including shield volcanoes on large regional rises such as Beta, Atla and Western Eistla Regiones and extensive flow fields such as Mylitta and Kaiwan Fluctus near the Lada Terra/Lavinia Planitia boundary. Of these features, coronae appear to possess the smallest amounts of associated volcanism, although volcanism associated with coronae has only been qualitatively examined. An initial survey of coronae based on recent Magellan data indicated that only 9 percent of all coronae are associated with substantial amounts of volcanism, including interior calderas or edifices greater than 50 km in diameter and extensive, exterior radial flow fields. Sixty-eight percent of all coronae were found to have lesser amounts of volcanism, including interior flooding and associated volcanic domes and small shields; the remaining coronae were considered deficient in associated volcanism. It is possible that coronae are related to mantle plumes or diapirs that are lower in volume or in partial melt than those associated with the large shields or flow fields. Regional tectonics or variations in local crustal and thermal structure may also be significant in determining the amount of volcanism produced from an upwelling. It is also possible that flow fields associated with some coronae are sheet-like in nature and may not be readily identified. If coronae are associated with volcanic flow fields, then they may be a significant contributor to plains formation on Venus, as they number over 300 and are widely distributed across the planet. As a continuation of our analysis of large-scale volcanism on Venus, we have reexamined the known population of coronae and assessed quantitatively the scale of volcanism associated

  13. Discharge current characteristics as an 'electrical method' for glow discharge plasma diagnosis

    International Nuclear Information System (INIS)

    Toma, M.; Paraschivescu, Alina; Morminches, Anisoara

    2001-01-01

    In its simplest form, the glow discharge can be established by passing an electric current through gas between two electrodes. The gas and the electrodes are contained in an insulating envelope. In many technological applications, and not only, the plasma devices are often treated like a black box. There is a series of external parameters or control variables which can be adjusted to obtain a desired effect, namely, the operating voltage, gas pressure, gas nature, gas flow rate, magnetic field strength and magnetic field configuration, electric field geometry, interelectrode distance, and cathode characteristics. The discharge current can be controlled by each of the above control variables. The core idea of this work is the following: a lot of information about the phenomena from the discharge volume, at electrodes or at the discharge bounding wall surface, can be obtained knowing how the change of one of the control parameters influences the discharge current. The following regimes were analyzed: dark discharges (background ionization, saturation regime, Townsend regime, corona regime), glow discharge (the normal and abnormal discharge) and arc discharge (glow to arc transition, non-thermal arcs, thermal arcs). It was concluded that the nonlinearity in the shape of the discharge current characteristics as a function of an external control parameter, can be correlated with the elementary processes and the dynamics of different space charge structures generated in plasma devices. (authors)

  14. Ileostomy - discharge

    Science.gov (United States)

    ... dried fruits (such as raisins), mushrooms, chunky relishes, coconut, and some Chinese vegetables. Tips for when no ... ask your doctor Living with your ileostomy Low-fiber diet Small bowel resection - discharge Total colectomy or ...

  15. Surface Treatment of PEOT/PBT (55/45 with a Dielectric Barrier Discharge in Air, Helium, Argon and Nitrogen at Medium Pressure

    Directory of Open Access Journals (Sweden)

    Pieter Cools

    2018-03-01

    Full Text Available This work describes the surface modification of 300PEO-PEOT/PBT 55/45 thin films using a medium pressure dielectric barrier discharge system operated in argon, helium, nitrogen or dry air to improve cell-surface interactions of this established biomaterial. The first part of the paper describes the optimization of the plasma processing parameters using water contact angle goniometry. The optimized samples are then characterized for changes in surface topography and surface chemical composition using atomic force microscopy (AFM and X-ray fluorescence spectroscopy (XPS respectively. For all plasma treatments, a pronounced increase in surface wettability was observed, of which the extent is dependent on the used plasma discharge gas. Except for dry air, only minor changes in surface topography were noted, while XPS confirmed that the changes in wettability were mainly chemical in nature with the incorporation of 5–10% of extra oxygen as a variety of polar groups. Similarly, for the nitrogen plasma, 3.8% of nitrogen polar groups were additionally incorporated. Human foreskin fibroblast (HFF in vitro analysis showed that within the first 24 h after cell seeding, the effects on cell-surface interactivity were highly dependent on the used discharge gas, nitrogen plasma treatment being the most efficient. Differences between untreated and plasma-treated samples were less pronounced compared to other biodegradable materials, but a positive influence on cell adhesion and proliferation was still observed.

  16. Alcohol, hospital discharge, and socioeconomic risk factors for default from multidrug resistant tuberculosis treatment in rural South Africa: a retrospective cohort study.

    Science.gov (United States)

    Kendall, Emily A; Theron, Danie; Franke, Molly F; van Helden, Paul; Victor, Thomas C; Murray, Megan B; Warren, Robin M; Jacobson, Karen R

    2013-01-01

    Default from multidrug-resistant tuberculosis (MDR-TB) treatment remains a major barrier to cure and epidemic control. We sought to identify patient risk factors for default from MDR-TB treatment and high-risk time periods for default in relation to hospitalization and transition to outpatient care. We retrospectively analyzed a cohort of 225 patients who initiated MDR-TB treatment between 2007 through 2010 at a rural TB hospital in the Western Cape Province, South Africa. Fifty percent of patients were cured or completed treatment, 27% defaulted, 14% died, 4% failed treatment, and 5% transferred out. Recent alcohol use was common (63% of patients). In multivariable proportional hazards regression, older age (hazard ratio [HR]= 0.97 [95% confidence interval 0.94-0.99] per year of greater age), formal housing (HR=0.38 [0.19-0.78]), and steady employment (HR=0.41 [0.19-0.90]) were associated with decreased risk of default, while recent alcohol use (HR=2.1 [1.1-4.0]), recent drug use (HR=2.0 [1.0-3.6]), and Coloured (mixed ancestry) ethnicity (HR=2.3 [1.1-5.0]) were associated with increased risk of default (PDefaults occurred throughout the first 18 months of the two-year treatment course but were especially frequent among alcohol users after discharge from the initial four-to-five-month in-hospital phase of treatment, with the highest default rates occurring among alcohol users within two months of discharge. Default rates during the first two months after discharge were also elevated for patients who received care from mobile clinics. Among patients who were not cured or did not complete MDR-TB treatment, the majority defaulted from treatment. Younger, economically-unstable patients and alcohol and drug users were particularly at risk. For alcohol users as well as mobile-clinic patients, the early outpatient treatment phase is a high-risk period for default that could be targeted in efforts to increase treatment completion rates.

  17. Initial field test of High-Energy Corona process for treating a contaminated soil-offgas stream

    International Nuclear Information System (INIS)

    Shah, R.R.; Garcia, R.E.; Jeffs, J.T.; Virden, J.W.; Heath, W.O.

    1995-04-01

    The High-Energy Corona (HEC) technology for treating process offgases has been under development at Pacific Northwest Laboratory (PNL) since 1991. The HEC process uses high-voltage electrical discharges in air to ionize the air, forming a low-temperature plasma that would be expected to destroy a wide variety of organic compounds in air. The plasma contains strong oxidants, possibly including hydroxyl radicals, hydroperoxy radicals, superoxide radicals, various excited as well as ionized forms of oxygen, high-energy electrons, and ultraviolet (UV) light. Because the high-voltage plasma is produced near ambient temperatures and pressures, yet exhibits extremely rapid destruction kinetics with relatively low power requirements, the HEC technique appears promising as a low-cost treatment technique (Virden et al. 1992). As part of the Volatile Organic Compound (VOC) Nonarid Integrated Demonstration (ID) at the DOE Savannah River Site, research activities were initiated in December 1991 to develop a prototype HEC process for a small-scale field demonstration to treat a soil-offgas stream contaminated with trichloroethylene (TCE) and perchloroethylene (PCE) at varying concentrations. Over an 18-month period, the HEC technology was developed on a fast track, through bench and pilot scales into a trailer-mounted system that was tested at the Nonarid ID. Other national laboratories, universities, and private companies have also participated at the Nonarid ID to demonstrate a number of conventional, emerging and innovative approaches for treating the same soil-offgas stream

  18. The Role of Electronegative Impurities in Ozone Generation by High Pressure Discharges

    International Nuclear Information System (INIS)

    Skalny, J.

    2000-01-01

    The high pressure discharges (pulsed or D C corona, barrier, gliding and the others), have been studied both experimentally and theoretically as sources of low temperature plasma for pollution control technologies. The potential of electrical discharge methods has been demonstrated for the decomposition of many types of VOC. The air or oxygen are used as a feed gas in which pollutant is diluted. The ozone production in air or oxygen in such discharges is also discussed

  19. Surface treatment by electric discharge machining of Ti–6Al–4V alloy for potential application in orthopaedics

    Czech Academy of Sciences Publication Activity Database

    Harcuba, P.; Bačáková, Lucie; Stráský, J.; Bačáková, Markéta; Novotná, Katarína; Janeček, M.

    2012-01-01

    Roč. 7, MAR (2012), s. 96-105 ISSN 1751-6161. [Symposium on Biological Materials Science /7./. San Diego, 27.02.2011-03.03.2011] R&D Projects: GA TA ČR(CZ) TA01011141 Institutional research plan: CEZ:AV0Z50110509 Keywords : electric discharge machining * surface roughness * mechanical properties Subject RIV: FI - Traumatology, Orthopedics Impact factor: 2.368, year: 2012

  20. The nanoparticle biomolecule corona: lessons learned - challenge accepted?

    Science.gov (United States)

    Docter, D; Westmeier, D; Markiewicz, M; Stolte, S; Knauer, S K; Stauber, R H

    2015-10-07

    Besides the wide use of engineered nanomaterials (NMs) in technical products, their applications are not only increasing in biotechnology and biomedicine, but also in the environmental field. While the physico-chemical properties and behaviour of NMs can be characterized accurately under idealized conditions, this is no longer the case in complex physiological or natural environments. Herein, proteins and other biomolecules rapidly bind to NMs, forming a protein/biomolecule corona that critically affects the NMs' (patho)biological and technical identities. As the corona impacts the in vitro and/or in vivo NM applications in humans and ecosystems, a mechanistic understanding of its relevance and of the biophysical forces regulating corona formation is mandatory. Based on recent insights, we here critically review and present an updated concept of corona formation and evolution. We comment on how corona signatures may be linked to effects at the nano-bio interface in physiological and environmental systems. In order to comprehensively analyse corona profiles and to mechanistically understand the coronas' biological/ecological impact, we present a tiered multidisciplinary approach. To stimulate progress in this field, we introduce the potential impact of the corona for NM-microbiome-(human)host interactions and the novel concept of 'nanologicals', i.e., the nanomaterial-specific targeting of molecular machines. We conclude by discussing the relevant challenges that still need to be resolved in this field.

  1. Pulsed positive corona streamer propagation and branching

    International Nuclear Information System (INIS)

    Veldhuizen, E.M. van; Rutgers, W.R.

    2002-01-01

    The propagation and branching of pulsed positive corona streamers in a short gap is observed with high resolution in space and time. The appearance of the pre-breakdown phenomena can be controlled by the electrode configuration, the gas composition and the impedance of the pulsed power circuit. In a point-wire gap the positive corona shows much more branching than in the parallel plane gap with a protrusion. In air, the branching is more pronounced than in argon. The pulsed power circuit appears to operate in two modes, either as an inductive circuit creating a lower number of thick streamers or as a resistive circuit giving a higher number of thin streamers. A possible cause for branching is electrostatic repulsion of two parts of the streamer head. The electric field at the streamer head is limited, the maximum values found are ∼170 kV cm -1 in air and ∼100 kV cm -1 in argon. At these maximum field strengths, the electrons have 5-10 eV energy, so the ionization is dominated by two-step processes. Differences between argon and ambient air in the field strength at which streamers propagate are ascribed to the difference in de-excitation processes in noble and molecular gases. The fact that the pulsed power circuit can control the streamer structure is important for applications, but this effect must also be taken into account in fundamental studies of streamer propagation and branching. (author)

  2. Pulsed positive corona streamer propagation and branching

    Energy Technology Data Exchange (ETDEWEB)

    Veldhuizen, E.M. van [Department of Physics, Technische Universiteit Eindhoven, Eindhoven (Netherlands)]. E-mail: e.m.v.veldhuizen@tue.nl; Rutgers, W.R. [Department of Physics, Technische Universiteit Eindhoven, Eindhoven (Netherlands)

    2002-09-07

    The propagation and branching of pulsed positive corona streamers in a short gap is observed with high resolution in space and time. The appearance of the pre-breakdown phenomena can be controlled by the electrode configuration, the gas composition and the impedance of the pulsed power circuit. In a point-wire gap the positive corona shows much more branching than in the parallel plane gap with a protrusion. In air, the branching is more pronounced than in argon. The pulsed power circuit appears to operate in two modes, either as an inductive circuit creating a lower number of thick streamers or as a resistive circuit giving a higher number of thin streamers. A possible cause for branching is electrostatic repulsion of two parts of the streamer head. The electric field at the streamer head is limited, the maximum values found are {approx}170 kV cm{sup -1} in air and {approx}100 kV cm{sup -1} in argon. At these maximum field strengths, the electrons have 5-10 eV energy, so the ionization is dominated by two-step processes. Differences between argon and ambient air in the field strength at which streamers propagate are ascribed to the difference in de-excitation processes in noble and molecular gases. The fact that the pulsed power circuit can control the streamer structure is important for applications, but this effect must also be taken into account in fundamental studies of streamer propagation and branching. (author)

  3. CORONA project -contribution to VVER nuclear education and training

    International Nuclear Information System (INIS)

    Ilieva, M.; Miteva, R.; Takov, T.

    2016-01-01

    CORONA Project is established to stimulate the transnational mobility and lifelong learning amongst VVER end users. The project aims to provide a special purpose structure for training of specialists and to maintain the nuclear expertise by gathering the existing and generating new knowledge in the VVER area. CORONA Project consists of two parts: CORONA I (2011-2014) ''Establishment of a regional center of competence for VVER technology and Nuclear Applications'', co-financed by the Framework Program 7 of the European Union (EU) and CORONA II (2015-2018) ''Enhancement of training capabilities in VVER technology through establishment of VVER training academy'', co-financed by HORIZON 2020, EURATOM 2014-2015. The selected form of the CORONA Academy, together with the online availability of the training opportunities will allow trainees from different locations to access the needed knowledge on demand. The project will target also new-comers in VVER community like Vietnam, Turkey, Belarus, etc. (authors)

  4. A comparison of reactive plasma pre-treatments on PET substrates by Cu and Ti pulsed-DC and HIPIMS discharges

    Energy Technology Data Exchange (ETDEWEB)

    Audronis, M., E-mail: m.audronis@yahoo.co.uk [Gencoa Ltd, Physics Road, Speke, Liverpool, L24 9HP (United Kingdom); Hinder, S.J. [The Surface Analysis Laboratory, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH (United Kingdom); Mack, P. [ThermoFisher Scientific Ltd, Imberhorne Lane, East Grinstead, Sussex, RH19 1UB (United Kingdom); Bellido-Gonzalez, V. [Gencoa Ltd, Physics Road, Speke, Liverpool, L24 9HP (United Kingdom); Bussey, D.; Matthews, A. [Department of Engineering Materials, University of Sheffield, Sheffield S1 3JD (United Kingdom); Baker, M.A. [The Surface Analysis Laboratory, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH (United Kingdom)

    2011-12-30

    PET web samples have been treated by magnetically enhanced glow discharges powered using either medium frequency pulse direct current (p-DC) or low frequency high power pulse (HIPIMS) sources. The plasma pre-treatment processes were carried out in an Ar-O{sub 2} atmosphere using either Cu or Ti sputter targets. XPS, AFM and sessile drop water contact angle measurements have been employed to examine changes in surface chemistry and morphology for different pre-treatment process parameters. Deposition of metal oxide onto the PET surface is observed as a result of the sputter magnetron-based glow discharge web treatment. Using the Cu target, both the p-DC and HIPIMS processes result in the formation of a thin CuO layer (with a thickness between 1 and 11 nm) being deposited onto the PET surface. Employing the Ti target, both p-DC and HIPIMS processes give rise to a much lower concentration of Ti (< 5 at.%), in the form of TiO{sub 2} on the PET treated surface. The TiO{sub 2} is probably distributed as an island-like distribution covering the PET surface. Presence of Cu and Ti oxide constituents on the treated PET is beneficial in aiding the adhesion but alone (i.e. without oxygen plasma activation) is not enough to provide very high levels of hydrophilicity as is clear from sessile drop water contact angle measurements on aged samples. Exposure to the plasma treatments leads to a small amount of roughening of the substrate surface, but the average surface roughness in all cases is below 2.5 nm. The PET structure at the interface with a coating is mostly or wholly preserved. The oxygen plasma treatment, metal oxide deposition and surface roughening resulting from the HIPIMS and p-DC treatments will promote adhesion to any subsequent thin film that is deposited immediately following the plasma treatment.

  5. Joint Soviet-French studies of the solar corona. II - Photometry of the solar corona on June 30, 1973

    Science.gov (United States)

    Vsekhsvyatsky, S. K.; Dzyubenko, N. I.; Ivanchuk, V. I.; Popov, O. S.; Rubo, G. A.; Koutchmy, S.; Koutchmy, O.; Shtelmacher, G.

    1981-04-01

    Results are presented of a study of negatives obtained on June 30, 1973 during the total solar eclipse in Africa; the study was part of a joint Soviet-French experiment on white corona dynamics, carried out by expeditions of Kiev University (Atar, Mauritania) and the Paris Astrophysical Institute (Moussoro, Chad). The distribution of total corona brightness up to 4.5 solar radii and its K and F corona components for east and north directions were found on the basis of novel methods of photometry and colorimetry using star images up to 8.5m as the photometry standards. Neither the color effect nor flattening is found in the inner part (less than 2.5 solar radii) of the F corona. Integral corona brightness in the standard zone of 1.03-6.00 solar radii was found to be 0.64 x 10 to the -6th solar-E.

  6. Plasma Discharge Process in a Pulsed Diaphragm Discharge System

    Science.gov (United States)

    Duan, Jianjin; Hu, Jue; Zhang, Chao; Wen, Yuanbin; Meng, Yuedong; Zhang, Chengxu

    2014-12-01

    As one of the most important steps in wastewater treatment, limited study on plasma discharge process is a key challenge in the development of plasma applications. In this study, we focus on the plasma discharge process of a pulsed diaphragm discharge system. According to the analysis, the pulsed diaphragm discharge proceeds in seven stages: (1) Joule heating and heat exchange stage; (2) nucleated site formation; (3) plasma generation (initiation of the breakdown stage); (4) avalanche growth and plasma expansion; (5) plasma contraction; (6) termination of the plasma discharge; and (7) heat exchange stage. From this analysis, a critical voltage criterion for breakdown is obtained. We anticipate this finding will provide guidance for a better application of plasma discharges, especially diaphragm plasma discharges.

  7. Morphological and surface compositional changes in poly(lactide-co-glycolide) tissue engineering scaffolds upon radio frequency glow discharge plasma treatment

    International Nuclear Information System (INIS)

    Djordjevic, Ivan; Britcher, Leanne G.; Kumar, Sunil

    2008-01-01

    Chemical functionalisation of polymeric scaffolds with functional groups such as amine could provide optimal conditions for loading of signalling biomolecules over the entire volume of the porous scaffolds. Three-dimensional (both surface and bulk) functionlisation of large volume scaffolds is highly desirable, but preferably without any change to the basic morphological, structural and bulk chemical properties of the scaffolds. In this work, we have carried out and compared treatments of poly(lactide-co-glycolide) tissue engineering scaffolds by two methods, that is, a wet chemical method using ethylenediamine and a glow discharge plasma method using heptylamine as a precursor. The samples thus prepared were analysed by scanning electron microscopy and X-ray photoelectron spectroscopy. The plasma treatment generated amide and protonated amine (NH + ) groups which were present in the bulk and on the surface of the scaffold. Amination also occurred for the wet chemical treatments but the structural and chemical integrity were adversely affected

  8. Morphological and surface compositional changes in poly(lactide-co-glycolide) tissue engineering scaffolds upon radio frequency glow discharge plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Djordjevic, Ivan [Ian Wark Research Institute, University of South Australia, Mawson Lakes, Adelaide, SA 5095 (Australia); Britcher, Leanne G. [Ian Wark Research Institute, University of South Australia, Mawson Lakes, Adelaide, SA 5095 (Australia)], E-mail: Leanne.Britcher@unisa.edu.au; Kumar, Sunil [Ian Wark Research Institute, University of South Australia, Mawson Lakes, Adelaide, SA 5095 (Australia)

    2008-01-30

    Chemical functionalisation of polymeric scaffolds with functional groups such as amine could provide optimal conditions for loading of signalling biomolecules over the entire volume of the porous scaffolds. Three-dimensional (both surface and bulk) functionlisation of large volume scaffolds is highly desirable, but preferably without any change to the basic morphological, structural and bulk chemical properties of the scaffolds. In this work, we have carried out and compared treatments of poly(lactide-co-glycolide) tissue engineering scaffolds by two methods, that is, a wet chemical method using ethylenediamine and a glow discharge plasma method using heptylamine as a precursor. The samples thus prepared were analysed by scanning electron microscopy and X-ray photoelectron spectroscopy. The plasma treatment generated amide and protonated amine (NH{sup +}) groups which were present in the bulk and on the surface of the scaffold. Amination also occurred for the wet chemical treatments but the structural and chemical integrity were adversely affected.

  9. Discharge Dialogue

    DEFF Research Database (Denmark)

    Horsbøl, Anders

    2012-01-01

    For several years, efforts have been made to strengthen collaboration between health professionals with different specializations and to improve patient transition from hospital to home (care). In the Danish health care system, these efforts have concentrated on cancer and heart diseases, whereas...... coordinator, employed at the hospital, is supposed to anticipate discharge and serve as mediator between the hospital and the municipal home care system. Drawing on methods from discourse and interaction analysis, the paper studies the practice of the discharge coordinator in two encounters between patients...... how the home context provides different resources for identification of patient needs and mutual decision making....

  10. Determination of dilution factors for discharge of aluminum-containing wastes by public water-supply treatment facilities into lakes and reservoirs in Massachusetts

    Science.gov (United States)

    Colman, John A.; Massey, Andrew J.; Brandt, Sara L.

    2011-09-16

    Dilution of aluminum discharged to reservoirs in filter-backwash effluents at water-treatment facilities in Massachusetts was investigated by a field study and computer simulation. Determination of dilution is needed so that permits for discharge ensure compliance with water-quality standards for aquatic life. The U.S. Environmental Protection Agency chronic standard for aluminum, 87 micrograms per liter (μg/L), rather than the acute standard, 750 μg/L, was used in this investigation because the time scales of chronic exposure (days) more nearly match rates of change in reservoir concentrations than do the time scales of acute exposure (hours).Whereas dilution factors are routinely computed for effluents discharged to streams solely on the basis of flow of the effluent and flow of the receiving stream, dilution determination for effluents discharged to reservoirs is more complex because (1), compared to streams, additional water is available for dilution in reservoirs during low flows as a result of reservoir flushing and storage during higher flows, and (2) aluminum removal in reservoirs occurs by aluminum sedimentation during the residence time of water in the reservoir. Possible resuspension of settled aluminum was not considered in this investigation. An additional concern for setting discharge standards is the substantial concentration of aluminum that can be naturally present in ambient surface waters, usually in association with dissolved organic carbon (DOC), which can bind aluminum and keep it in solution.A method for dilution determination was developed using a mass-balance equation for aluminum and considering sources of aluminum from groundwater, surface water, and filter-backwash effluents and losses caused by sedimentation, water withdrawal, and spill discharge from the reservoir. The method was applied to 13 reservoirs. Data on aluminum and DOC concentrations in reservoirs and influent water were collected during the fall of 2009. Complete

  11. Effects of wastewater effluent discharge and treatment facility upgrades on environmental and biological conditions of Indian Creek, Johnson County, Kansas, June 2004 through June 2013

    Science.gov (United States)

    Graham, Jennifer L.; Stone, Mandy L.; Rasmussen, Teresa J.; Foster, Guy M.; Poulton, Barry C.; Paxson, Chelsea R.; Harris, Theodore D.

    2014-01-01

    Indian Creek is one of the most urban drainage basins in Johnson County, Kansas, and environmental and biological conditions of the creek are affected by contaminants from point and other urban sources. The Johnson County Douglas L. Smith Middle Basin (hereafter referred to as the “Middle Basin”) and Tomahawk Creek Wastewater Treatment Facilities (WWTFs) discharge to Indian Creek. In summer 2010, upgrades were completed to increase capacity and include biological nutrient removal at the Middle Basin facility. There have been no recent infrastructure changes at the Tomahawk Creek facility; however, during 2009, chemically enhanced primary treatment was added to the treatment process for better process settling before disinfection and discharge with the added effect of enhanced phosphorus removal. The U.S. Geological Survey, in cooperation with Johnson County Wastewater, assessed the effects of wastewater effluent on environmental and biological conditions of Indian Creek by comparing two upstream sites to four sites located downstream from the WWTFs using data collected during June 2004 through June 2013. Environmental conditions were evaluated using previously and newly collected discrete and continuous data and were compared with an assessment of biological community composition and ecosystem function along the upstream-downstream gradient. This study improves the understanding of the effects of wastewater effluent on stream-water and streambed sediment quality, biological community composition, and ecosystem function in urban areas. After the addition of biological nutrient removal to the Middle Basin WWTF in 2010, annual mean total nitrogen concentrations in effluent decreased by 46 percent, but still exceeded the National Pollutant Discharge Elimination System (NPDES) wastewater effluent permit concentration goal of 8.0 milligrams per liter (mg/L); however, the NPDES wastewater effluent permit total phosphorus concentration goal of 1.5 mg/L or less was

  12. Effect of electronegative additives on physical properties and chemical activity of gas discharge plasma

    Science.gov (United States)

    Kuznetsov, D. L.; Filatov, I. E.; Uvarin, V. V.

    2018-01-01

    Effect of electronegative additives (oxygen O2, sulfur dioxide SO2, carbon disulfide CS2, and carbon tetrachloride CCl4) on physical properties and chemical activity of plasma formed by pulsed corona discharge and by non-self-sustained discharge supported by pulsed electron beam in atmospheric pressure gas mixtures was investigated. It is shown that a decrease in discharge current depends on a sort of the additive and on its concentration. The reason is the difference in rate constants of electron attachment processes for the above molecules. In experiments on volatile organic compounds (VOCs) conversion in air by streamer corona it is obtained that an addition of CCl4 both decreases the discharge current amplitude and increases the VOCs conversion degree. An installation for investigation of electron attachment processes and for study of toxic impurities conversion in plasma formed by non-self-sustained discharge initiated by pulsed nanosecond electron beam is created.

  13. Corona ignition system for highly efficient gasoline engines; Corona-Zuendsystem fuer hocheffiziente Ottomotoren

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, John [Federal-Mogul Limited, Manchester (United Kingdom); Lykowski, Jim; Mixell, Kristapher [Federal-Mogul, Plymouth, MI (United States)

    2013-06-01

    Many future gasoline engines will require higher air/fuel ratios and higher mean effective pressures to further improve fuel efficiency. Federal-Mogul has taken up this challenge and has developed the Advanced Corona Ignition System (ACIS) as a new solution to reliably ignite a mix with high AFR/EGR and high MEP. During engine tests ACIS enabled a direct fuel economy improvement of up to 10 %. (orig.)

  14. AIR ATMOSPHERIC-PRESSURE DISCHARGERS FOR OPERATION IN HIGH-FREQUENCY SWITCHING MODE.

    Directory of Open Access Journals (Sweden)

    L.S. Yevdoshenko

    2013-10-01

    Full Text Available Operation of two designs of compact multigap dischargers has been investigated in a high-frequency switching mode. It is experimentally revealed that the rational length of single discharge gaps in the designs is 0.3 mm, and the maximum switching frequency is 27000 discharges per second under long-term stable operation of the dischargers. It is shown that in pulsed corona discharge reactors, the pulse front sharpening results in increasing the operating electric field strength by 1.3 – 1.8 times.

  15. Discharge lamp technologies

    Energy Technology Data Exchange (ETDEWEB)

    Dakin, J. [GE Lighting, Cleveland, OH (United States)

    1994-12-31

    This talk is an overview of discharge lamp technology commonly employed in general lighting, with emphasis on issues pertinent to lighting for plant growth. Since the audience is primarily from the plant growth community, and this begins the light source part of the program, we will start with a brief description of the discharge lamps. Challenges of economics and of thermal management make lamp efficiency a prime concern in controlled environment agriculture, so we will emphasize science considerations relating to discharge lamp efficiency. We will then look at the spectra and ratings of some representative lighting products, and conclude with a discussion of technological advance. A general overview of discharge lighting technology can be found in the book of Waymouth (1971). A recent review of low pressure lighting discharge science is found in Dakin (1991). The pioneering paper of Reiling (1964) provides a good introduction to metal halide discharges. Particularly relevant to lighting for plant growth, a recent and thorough treatment of high pressure Na lamps is found in the book by deGroot and vanVliet (1986). Broad practical aspects of lighting application are thoroughly covered in the IES Lighting Handbook edited by Kaufman (1984).

  16. Evolution of CME Mass in the Corona

    Science.gov (United States)

    Howard, Russell A.; Vourlidas, Angelos

    2018-04-01

    The idea that coronal mass ejections (CMEs) pile up mass in their transport through the corona and heliosphere is widely accepted. However, it has not been shown that this is the case. We perform an initial study of the volume electron density of the fronts of 13 three-part CMEs with well-defined frontal boundaries observed with the Solar and Heliospheric Observatory/ Large Angle and Spectrometric COronagraph (SOHO/LASCO) white-light coronagraphs. We find that, in all cases, the volume electron density decreases as the CMEs travel through the LASCO-C2 and -C3 fields of view, from 2.6 - 30 R_{⊙}. The density decrease follows closely a power law with an exponent of -3, which is consistent with a simple radial expansion. This indicates that in this height regime there is no observed pile-up.

  17. Nonlinearity and instability in stellar coronae

    International Nuclear Information System (INIS)

    Martens, P.C.H.

    1983-01-01

    This thesis is mainly concerned with time dependent processes occurring in the hot and teneous plasma - about 1 million degrees and higher and less than 10 10 cm density - that forms the outer envelopes of many stars including the sun. These envelopes - coronae - emit X-rays and indirectly in the ultraviolet and are therefore mainly observed by satellite techniques. Part I consists of a general introduction to the work and an overview of the non-linear methods that are used in the following. Part II and part III are concerned with respectively open and closed coronal structures. There is great similarity in the physics of these two systems, but the open structures are somewhat more complicated. (Auth.)

  18. Gas discharge plasma treatment of poly(ethylene glycol-co-1,3/1,4 cyclohexanedimethanol terephthalate) for enhanced paint adhesion

    International Nuclear Information System (INIS)

    Salapare, Hernando S.; Cosiñero, Hannah Shamina O.; Suarez, Beverly Anne T.; Bacaoco, Miguel Y.; Ramos, Henry J.; Nuñez, Julius Andrew P.; Guittard, Frédéric

    2016-01-01

    Low-energy hydrogen-ions and tetrafluoromethane-ions produced from a gas discharge ion source were irradiated to poly(ethylene glycol-co-1,3/1,4 cyclohexanedimethanol terephthalate) (PETG) sheets for enhancing paint adhesion. The ion beams were characterized using a cast steel mass spectrometer, while the untreated and treated samples were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, contact angle measurements, and profilometry. The paint adhesion was determined by using the standard method for evaluating adhesion by knife [ASTM D6677-07, Standard Test Method for Evaluating Adhesion by Knife (ASTM International, West Conshohocken, PA, 2012)] and was correlated with the calculation of the work of adhesion derived from the Young–Dupré equation. After plasma treatment, a significant decrease in the contact angle was observed in all samples, except for the CF_4 ion-treated samples with the discharge current of 3 mA and an irradiation time of 30 min. At longer irradiation times, the treated samples showed lesser changes in the contact angle measurement. The increase in the average and root-mean-square surface roughness was observed on the samples after plasma treatment. The samples treated with either H_2 or CF_4 ions for 15 min showed a direct correlation between the discharge current and surface roughness. The samples treated for 30 min showed no significant correlation between the surface roughness and discharge current, which can be attributed to the possible melting of the samples since PETG has a low melting point. The observation made in this study on the relationship of wettability and surface roughness is consistent with the Wenzel wetting mode. Scanning electron micrographs showed surface etching on the hydrogen ion-treated samples while no significant surface changes were observed for the CF_4 ion-treated samples. In general, paint adhesion was stronger for samples that exhibited enhanced wettability

  19. Gas discharge plasma treatment of poly(ethylene glycol-co-1,3/1,4 cyclohexanedimethanol terephthalate) for enhanced paint adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Salapare, Hernando S., E-mail: hssalapare@up.edu.ph [Université Nice Sophia Antipolis, CNRS, LPMC, UMR 7336, Parc Valrose, 06100 Nice (France); Department of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Manila, Manila City 1000 (Philippines); College of Science, Pamantasan ng Lungsod ng Maynila, Intramuros, Manila City 1002 (Philippines); Cosiñero, Hannah Shamina O. [Materials Science and Engineering Program, College of Science, University of the Philippines Diliman, Quezon City 1101 (Philippines); Suarez, Beverly Anne T. [Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan); Bacaoco, Miguel Y.; Ramos, Henry J. [National Institute of Physics, College of Science, University of the Philippines Diliman, Quezon City 1101 (Philippines); Nuñez, Julius Andrew P. [Department of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Manila, Manila City 1000, Philippines and Materials Science and Engineering Program, College of Science, University of the Philippines Diliman, Quezon City 1101 (Philippines); Guittard, Frédéric [Université Nice Sophia Antipolis, CNRS, LPMC, UMR 7336, Parc Valrose, 06100 Nice (France)

    2016-07-15

    Low-energy hydrogen-ions and tetrafluoromethane-ions produced from a gas discharge ion source were irradiated to poly(ethylene glycol-co-1,3/1,4 cyclohexanedimethanol terephthalate) (PETG) sheets for enhancing paint adhesion. The ion beams were characterized using a cast steel mass spectrometer, while the untreated and treated samples were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, contact angle measurements, and profilometry. The paint adhesion was determined by using the standard method for evaluating adhesion by knife [ASTM D6677-07, Standard Test Method for Evaluating Adhesion by Knife (ASTM International, West Conshohocken, PA, 2012)] and was correlated with the calculation of the work of adhesion derived from the Young–Dupré equation. After plasma treatment, a significant decrease in the contact angle was observed in all samples, except for the CF{sub 4} ion-treated samples with the discharge current of 3 mA and an irradiation time of 30 min. At longer irradiation times, the treated samples showed lesser changes in the contact angle measurement. The increase in the average and root-mean-square surface roughness was observed on the samples after plasma treatment. The samples treated with either H{sub 2} or CF{sub 4} ions for 15 min showed a direct correlation between the discharge current and surface roughness. The samples treated for 30 min showed no significant correlation between the surface roughness and discharge current, which can be attributed to the possible melting of the samples since PETG has a low melting point. The observation made in this study on the relationship of wettability and surface roughness is consistent with the Wenzel wetting mode. Scanning electron micrographs showed surface etching on the hydrogen ion-treated samples while no significant surface changes were observed for the CF{sub 4} ion-treated samples. In general, paint adhesion was stronger for samples that exhibited

  20. Effect of corona electric field on the production of gamma-poly glutamic acid based on bacillus natto

    Science.gov (United States)

    Qi, Hong; Na, Ri; Xin, Jiletu; Jie Xie, Ya; Guo, Jiu Feng

    2013-03-01

    Bacillus Natto is an important strain for gamma-poly glutamic acid (γ-PGA) production. The mutagenesis of Bacillus Natto 20646 under corona electric field and the screening of high γ-PGA producing mutant were investigated. A new mutant bacillus natto Ndlz01 was isolated from Bacillus Natto 20646 after mutation in corona electric field at 9kV for 2min. The Ndlz01 exhibited genetic stability of high γ-PGA producing ability even after five generation cultures. When the bacterium was mutated in streamer discharge state at 9kV for 2min, its death rate was more than 90%. Compared with the yield of γ-PGA based on the original Bacillus Natto 20646, the γ-PGA yield of mutant bacillus natto Ndlz01 increased from 2.6 to 5.94 g/L, with an increase rate of 129.78%.

  1. Effect of corona electric field on the production of gamma-poly glutamic acid based on bacillus natto

    International Nuclear Information System (INIS)

    Qi, Hong; Na, Ri; Xin, Jiletu; Xie, Ya Jie; Guo, Jiu Feng

    2013-01-01

    Bacillus Natto is an important strain for gamma-poly glutamic acid (γ-PGA) production. The mutagenesis of Bacillus Natto 20646 under corona electric field and the screening of high γ-PGA producing mutant were investigated. A new mutant bacillus natto Ndlz01 was isolated from Bacillus Natto 20646 after mutation in corona electric field at 9kV for 2min. The Ndlz01 exhibited genetic stability of high γ-PGA producing ability even after five generation cultures. When the bacterium was mutated in streamer discharge state at 9kV for 2min, its death rate was more than 90%. Compared with the yield of γ-PGA based on the original Bacillus Natto 20646, the γ-PGA yield of mutant bacillus natto Ndlz01 increased from 2.6 to 5.94 g/L, with an increase rate of 129.78%.

  2. Treatment of nitridation by microwave post discharge plasma in an AISI 4140 steel; Tratamiento de nitruracion por plasma post-descarga micro-ondas en un acero AISI 4140

    Energy Technology Data Exchange (ETDEWEB)

    Medina F, A. [Instituto Tecnologico de Morelia, Morelia e Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Rodriguez L, V.; Zamora R, L. [ININ, Mexico D.F. (Mexico); Oseguera P, J

    1998-07-01

    The objective of this work is to determine through X-ray diffraction, microhardness measurement and scanning electron microscopy those main operation parameters of the microwave post discharge treatment (temperature of treatment, gas mixture and permanence time) nitriding an AISI 4140 steel and to characterize the compact layer of nitrides formed during the treatment. (Author)

  3. The TESIS experiment on the CORONAS-PHOTON spacecraft

    Science.gov (United States)

    Kuzin, S. V.; Zhitnik, I. A.; Shestov, S. V.; Bogachev, S. A.; Bugaenko, O. I.; Ignat'ev, A. P.; Pertsov, A. A.; Ulyanov, A. S.; Reva, A. A.; Slemzin, V. A.; Sukhodrev, N. K.; Ivanov, Yu. S.; Goncharov, L. A.; Mitrofanov, A. V.; Popov, S. G.; Shergina, T. A.; Solov'ev, V. A.; Oparin, S. N.; Zykov, A. M.

    2011-04-01

    On February 26, 2009, the first data was obtained in the TESIS experiment on the research of the solar corona using imaging spectroscopy. The TESIS is a part of the scientific equipment of the CORONAS-PHO-TON spacecraft and is designed for imaging the solar corona in soft X-ray and extreme ultraviolet regions of the spectrum with high spatial, spectral, and temporal resolutions at altitudes from the transition region to three solar radii. The article describes the main characteristics of the instrumentation, management features, and operation modes.

  4. Core-Shell-Corona Micelles with a Responsive Shell.

    Science.gov (United States)

    Gohy, Jean-François; Willet, Nicolas; Varshney, Sunil; Zhang, Jian-Xin; Jérôme, Robert

    2001-09-03

    A reactor for the synthesis of gold nanoparticles is one of the uses of a poly(styrene)-block-poly(2-vinylpyridine)-block-poly(ethylene oxide) triblock copolymer (PS-b-P2VP-b-PEO) which forms core-shell-corona micelles in water. Very low polydispersity spherical micelles are observed that consist of a PS core surrounded by a pH-sensitive P2VP shell and a corona of PEO chains end-capped by a hydroxyl group. The corona can act as a site for attaching responsive or sensing molecules. © 2001 WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany.

  5. Discharges of produced waters from oil and gas extraction via wastewater treatment plants are sources of disinfection by-products to receiving streams

    Science.gov (United States)

    Hladik, Michelle; Focazio, Michael J.; Engle, Mark

    2014-01-01

    Fluids co-produced with oil and gas production (produced waters) are often brines that contain elevated concentrations of bromide. Bromide is an important precursor of several toxic disinfection by-products (DBPs) and the treatment of produced water may lead to more brominated DBPs. To determine if wastewater treatment plants that accept produced waters discharge greater amounts of brominated DBPs, water samples were collected in Pennsylvania from four sites along a large river including an upstream site, a site below a publicly owned wastewater treatment plant (POTW) outfall (does not accept produced water), a site below an oil and gas commercial wastewater treatment plant (CWT) outfall, and downstream of the POTW and CWT. Of 29 DBPs analyzed, the site at the POTW outfall had the highest number detected (six) ranging in concentration from 0.01 to 0.09 μg L− 1 with a similar mixture of DBPs that have been detected at POTW outfalls elsewhere in the United States. The DBP profile at the CWT outfall was much different, although only two DBPs, dibromochloronitromethane (DBCNM) and chloroform, were detected, DBCNM was found at relatively high concentrations (up to 8.5 μg L− 1). The water at the CWT outfall also had a mixture of inorganic and organic precursors including elevated concentrations of bromide (75 mg L− 1) and other organic DBP precursors (phenol at 15 μg L− 1). To corroborate these DBP results, samples were collected in Pennsylvania from additional POTW and CWT outfalls that accept produced waters. The additional CWT also had high concentrations of DBCNM (3.1 μg L− 1) while the POTWs that accept produced waters had elevated numbers (up to 15) and concentrations of DBPs, especially brominated and iodinated THMs (up to 12 μg L− 1 total THM concentration). Therefore, produced water brines that have been disinfected are potential sources of DBPs along with DBP precursors to streams wherever these wastewaters are discharged.

  6. Angioplasty and stent - heart - discharge

    Science.gov (United States)

    Drug-eluting stents - discharge; PCI - discharge; Percutaneous coronary intervention - discharge; Balloon angioplasty - discharge; Coronary angioplasty - discharge; Coronary artery angioplasty - discharge; Cardiac ...

  7. Radioactive wastes and discharges

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The guide sets out the radiation safety requirements and limits for the treatment of radioactive waste. They shall be observed when discharging radioactive substances into the atmosphere or sewer system, or when delivering solid, low-activity waste to a landfill site without a separate waste treatment plan. The guide does not apply to the radioactive waste resulting from the utilisation of nuclear energy or natural resources.

  8. Radioactive wastes and discharges

    International Nuclear Information System (INIS)

    2000-01-01

    The guide sets out the radiation safety requirements and limits for the treatment of radioactive waste. They shall be observed when discharging radioactive substances into the atmosphere or sewer system, or when delivering solid, low-activity waste to a landfill site without a separate waste treatment plan. The guide does not apply to the radioactive waste resulting from the utilisation of nuclear energy or natural resources

  9. Radiological discharges

    International Nuclear Information System (INIS)

    Woodliffe, J.

    1990-01-01

    Current practice of North Sea States on the discharge and disposal of liquid radioactive wastes to the North Sea are based on the declaration issued at the Second International Conference on the Protection of the North Sea, known as the London Declaration. This has three main points the first of which emphasises the application of the Best Available Technology to protect the North Sea, the second provides a framework on which future controls on radioactive discharges should be based. The third identifies two parts of the framework; to take into account the recommendations of international organizations and that any repositories of radioactive waste which are built should not pollute the North Sea. This chapter looks at how the concensus based on the London Declaration is working, gauges the progress made in the implementation of the policy goal, identifies existing and future areas for concern and proposes ways of strengthening the control of radioactive discharges. The emphasis is on the United Kingdom practice and regulations for liquid wastes, most of which comes from the Sellafield Reprocessing Plant. (author)

  10. Soviet-France cooperative study of the solar corona

    International Nuclear Information System (INIS)

    Vsekhvsyatskij, S.K.; Dzyubenko, N.I.; Ivanchuk, V.I.; Popov, O.S.; Rubo, G.A.; Kuchmij, S.; Kuchmij, O.; Shtel'makher, G.

    1981-01-01

    The study continues the investigations on the solar corona performed according to the program of the Soviet-France experiment ''The white corona dynamics'' during total solar eclipses on July 10 1972 and June 30, 1973 by the expeditions of Kiev University and Paris Astrophysical Institute. The results of the study of eclipse negatives obtained on June 30 1973 in Africa are given. On the basis of new methods of photometry and colorimetry using star images up to 8.5sup(m) as the photometry standards it has been found with high accuracy the distribution of the total corona brightness up to r approximately equal to 4.5 Rsub(S) and its K- and F-corona components for E and N directions. Neither color effect nor flattening is found in the dust component (r -6 Esub(S)

  11. Reticulated Vitreous Carbon Electrodes for Gas Phase Pulsed Corona Reactors

    National Research Council Canada - National Science Library

    Locke, B

    1998-01-01

    A new design for gas phase pulsed corona reactors incorporating reticulated vitreous carbon electrodes is demonstrated to be effective for the removal of nitrogen oxides from synthetic air mixtures...

  12. Reticulated Vitreous Carbon Electrodes for Gas Phase Pulsed Corona Reactors

    National Research Council Canada - National Science Library

    LOCKE, B

    1999-01-01

    A new design for gas phase pulsed corona reactors incorporating reticulated vitreous carbon electrodes is demonstrated to be effective for the removal of nitrogen oxides from synthetic air mixtures...

  13. High-tension corona controlled ozone generator for environment protection

    International Nuclear Information System (INIS)

    Vijayan, T; Patil, Jagadish G

    2010-01-01

    Engineering details of a high voltage driven corona-plasma ozone generator are described. The plasma diode of generator has coaxial cylindrical geometry with cathode located inside anode. Cathode is made of a large number of radial gas nozzles arranged on central tubular mast which admits oxygen gas. The sharp endings of the nozzles along with a set of corona rings create the high electric field at the cathode required for formation of dense corona plume responsible for O 3 evolution. A model of coronal plasma generation and ozone production is presented. The plasma formation is strongly dependent on the electric field and temperature in side diode where a high electron density in a low temperature negative corona is suited for high ozone yields. These are established by suitable regulation of A-K gap, voltage, oxygen pressure, and cathode-nozzle population.

  14. Compensating Faraday Depolarization by Magnetic Helicity in the Solar Corona

    Energy Technology Data Exchange (ETDEWEB)

    Brandenburg, Axel; Ashurova, Mohira B. [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States); Jabbari, Sarah, E-mail: brandenb@nordita.org [School of Mathematical Sciences and Monash Centre for Astrophysics, Monash University, Clayton, VIC 3800 (Australia)

    2017-08-20

    A turbulent dynamo in spherical geometry with an outer corona is simulated to study the sign of magnetic helicity in the outer parts. In agreement with earlier studies, the sign in the outer corona is found to be opposite to that inside the dynamo. Line-of-sight observations of polarized emission are synthesized to explore the feasibility of using the local reduction of Faraday depolarization to infer the sign of helicity of magnetic fields in the solar corona. This approach was previously identified as an observational diagnostic in the context of galactic magnetic fields. Based on our simulations, we show that this method can be successful in the solar context if sufficient statistics are gathered by using averages over ring segments in the corona separately for the regions north and south of the solar equator.

  15. Are All Flare Ribbons Simply Connected to the Corona?

    Energy Technology Data Exchange (ETDEWEB)

    Judge, Philip G. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Paraschiv, Alin; Lacatus, Daniela; Donea, Alina [Monash Center for Astrophysics, School of Mathematical Science, Monash University, Victoria 3800 (Australia); Lindsey, Charlie, E-mail: judge@ucar.edu, E-mail: alina.donea@monash.edu, E-mail: alin.paraschiv@monash.edu, E-mail: daniela.lacatus@monash.edu, E-mail: indsey@cora.nwra.com [Northwest Research Associates, 3380 Mitchell Lane, Boulder, CO 80301 (United States)

    2017-04-01

    We consider the observational basis for the belief that flare ribbons in the chromosphere result from energy transport from the overlying corona. We study ribbons of small flares using magnetic and intensity data from the Hinode , Solar Dynamics Observatory , and IRIS missions. While most ribbons appear connected to the corona and overlie regions of significant vertical magnetic field, we examine one ribbon with no clear evidence for such connections. Evolving horizontal magnetic fields seen with Hinode suggest that reconnection with preexisting fields below the corona can explain the data. The identification of just one, albeit small, ribbon, with no apparent connection to the corona, leads us to conclude that at least two mechanisms are responsible for the heating that leads to flare ribbon emission.

  16. Design of Thermochromic Polynorbornene Bearing Spiropyran Chromophore Moieties: Synthesis, Thermal Behavior and Dielectric Barrier Discharge Plasma Treatment

    Directory of Open Access Journals (Sweden)

    Saleh A. Ahmed

    2017-11-01

    Full Text Available A new class of thermochromic polynorbornene with pendent spiropyran moieties has been synthesized. Functionalization of norbornene monomers with spirobenzopyran moieties has been achieved using Steglich esterification. These new monomeric materials were polymerized via Ring Opening Metathesis Polymerization (ROMP. In spite of their poor solubility, polynorbornenes with spirobenzopyran exhibited thermochromic behavior due to the conversion of their closed spiropyran moieties to the open merocyanine form. Moreover, these polymers displayed bathochromic shifts in their optical response, which was attributed to the J-aggregation of the attached merocyanine moieties that were associated with their high concentration in the polymeric chain. The surface of the obtained polymers was exposed to atmospheric pressure air Dielectric Barrier Discharge (DBD plasma system, which resulted in the reduction of the surface porosity and converted some surface area into completely non-porous regions. Moreover, the plasma system created some areas with highly ordered J-aggregates of the merocyanine form in thread-like structures. This modification of the polymers’ morphology may alter their applications and allow for these materials to be potential candidates for new applications, such as non-porous membranes for reverse osmosis, nanofiltration, or molecular separation in the gas phase.

  17. Geophysical and hydrogeological characterisation of the impacts of on-site wastewater treatment discharge to groundwater in a poorly productive bedrock aquifer

    International Nuclear Information System (INIS)

    Donohue, Shane; McCarthy, Valerie; Rafferty, Patrick; Orr, Alison; Flynn, Raymond

    2015-01-01

    Contaminants discharging from on-site wastewater treatment systems (OSWTSs) can impact groundwater quality, threatening human health and surface water ecosystems. Risk of negative impacts becomes elevated in areas of extreme vulnerability with high water tables, where thin unsaturated intervals limit vadose zone attenuation. A combined geophysical/hydrogeological investigation into the effects of an OSWTS, located over a poorly productive aquifer (PPA) with thin subsoil cover, aimed to characterise effluent impacts on groundwater. Groundwater, sampled from piezometers down-gradient of the OSWTS percolation area displayed spatially erratic, yet temporally consistent, contaminant distributions. Electrical resistivity tomography identified an area of gross groundwater contamination close to the percolation area and, when combined with seismic refraction and water quality data, indicated that infiltrating effluent reaching the water table discharged to a deeper more permeable zone of weathered shale resting on more competent bedrock. Subsurface structure, defined by geophysics, indicated that elevated chemical and microbiological contaminant levels encountered in groundwater samples collected from piezometers, down-gradient of sampling points with lower contaminant levels, corresponded to those locations where piezometers were screened close to the weathered shale/competent rock interface; those immediately up-gradient were too shallow to intercept this interval, and thus the more impacted zone of the contaminant plume. Intermittent occurrence of faecal indicator bacteria more than 100 m down gradient of the percolation area suggested relatively short travel times. Study findings highlight the utility of geophysics as part of multidisciplinary investigations for OSWTS contaminant plume characterisation, while also demonstrating the capacity of effluent discharging to PPAs to impact groundwater quality at distance. Comparable geophysical responses observed in similar

  18. Geophysical and hydrogeological characterisation of the impacts of on-site wastewater treatment discharge to groundwater in a poorly productive bedrock aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Donohue, Shane [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, Northern Ireland (United Kingdom); McCarthy, Valerie; Rafferty, Patrick [Department of Applied Sciences, Dundalk Institute of Technology, Dublin Road, Dundalk (Ireland); Orr, Alison; Flynn, Raymond [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, Northern Ireland (United Kingdom)

    2015-08-01

    Contaminants discharging from on-site wastewater treatment systems (OSWTSs) can impact groundwater quality, threatening human health and surface water ecosystems. Risk of negative impacts becomes elevated in areas of extreme vulnerability with high water tables, where thin unsaturated intervals limit vadose zone attenuation. A combined geophysical/hydrogeological investigation into the effects of an OSWTS, located over a poorly productive aquifer (PPA) with thin subsoil cover, aimed to characterise effluent impacts on groundwater. Groundwater, sampled from piezometers down-gradient of the OSWTS percolation area displayed spatially erratic, yet temporally consistent, contaminant distributions. Electrical resistivity tomography identified an area of gross groundwater contamination close to the percolation area and, when combined with seismic refraction and water quality data, indicated that infiltrating effluent reaching the water table discharged to a deeper more permeable zone of weathered shale resting on more competent bedrock. Subsurface structure, defined by geophysics, indicated that elevated chemical and microbiological contaminant levels encountered in groundwater samples collected from piezometers, down-gradient of sampling points with lower contaminant levels, corresponded to those locations where piezometers were screened close to the weathered shale/competent rock interface; those immediately up-gradient were too shallow to intercept this interval, and thus the more impacted zone of the contaminant plume. Intermittent occurrence of faecal indicator bacteria more than 100 m down gradient of the percolation area suggested relatively short travel times. Study findings highlight the utility of geophysics as part of multidisciplinary investigations for OSWTS contaminant plume characterisation, while also demonstrating the capacity of effluent discharging to PPAs to impact groundwater quality at distance. Comparable geophysical responses observed in similar

  19. Properties of minimum-flux coronae in dwarfs and giants

    International Nuclear Information System (INIS)

    Mullan, D.J.

    1976-01-01

    Using a method due to Hearn, we examine the properties of minimum-flux coronae in dwarfs and giants. If the fraction phi of the total stellar luminosity which is used to heat the corona is equal to the solar value phi/sub s/, then red dwarfs must have coronae that are cooler than the solar corona: in UV Ceti, for example, the coronal temperature is a factor 3 less than in the Sun. This is consistent with an independent estimate of coronal temperature in a flare star. If phi=phi/sub s/, main-sequence stars hotter than the Sun have coronae which are hotter than the solar corona. Soft X-rays from Sirius suggest that the coronal temperature in Sirius is indeed hotter than the Sun by a factor of about 40 percent. Giants show an even more marked decrease in coronal temperature at later spectral type than do the dwarfs. We suggest that the reason for the presence of O V emission in β Gem and O VI emission in α Aur, and the absence of O V emission in α Boo and α Tau, is that the coronae in the latter two stars are cooler (rather than hotter, as McClintock et al. have suggested) than in the former two. Our results explain why it is more likely that mass loss has been detected in α Aur and α Boo, but not in α Tau or β Gem. Using a simple flare model, we show that flares in both a dwarf star (UV Ceti) and a giant (α Aur) were initiated not in the corona, but in the transition region

  20. The energy and pressure balance in the corona

    International Nuclear Information System (INIS)

    McWhirter, R.W.P.; Wilson, R.

    1976-01-01

    This paper reviews theoretical models for the solar corona based on energy and pressure calculations. Processes included in these calculations are: (a) heating of the outer corona by mechanical waves; (b) convective out-flow of gas giving rise to the solar wind; (c) thermal conductions; (d) radiated power loss. Possible observations to help answer some of the outstanding questions about the energy balance are suggested. (author)