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Sample records for stabilization discharge sources

  1. Ballooning stability of JET discharges

    International Nuclear Information System (INIS)

    Huysmans, G.T.A.; Goedbloed, J.P.; Galvao, R.M.O.; Lazzaro, E.; Smeulders, P.

    1989-01-01

    Conditions under which ballooning modes are expected to be excited have recently been obtained in two different types of discharges in JET. In the first type, extremely large pressure gradients have been produced in the plasma core through pellet injections in the current rise phase followed by strong additional heating. In the second type, the total pressure of the discharge is approaching the Troyon limit. The stability of these discharges with respect to the ideal MHD ballooning modes has been studied with the stability code HBT. The equilibria are reconstructed with the IDENTC code using the external magnetic measurements and the experimental pressure profile. The results show that the evaluated high beta discharge is unstable in the central region of the plasma. This instability is related to the low shear and not to a large pressure gradient, as expected at the Troyon limit. In the pellet discharges the regions with the large pressure gradients are unstable to ballooning modes at the time of the beta decay, which ends the period of enhanced performance. The maximum pressure gradient in these discharges is limited by the boundary of the first region of stability. The observed phenomena at the beta decay are similar to those observed at the beta limit in DIII-D and TFTR. (author)

  2. Ideal ballooning stability of JET discharges

    International Nuclear Information System (INIS)

    Galvao, R.M.O.; Lazzaro, E.; O'Rourke, J.; Smeulders, P.; Schmidt, G.

    1989-01-01

    Conditions under which ballooning modes are expected to be excited have recently been obtained in two different types of discharges in JET. In the first type, discharges with β approaching the Troyon-Sykes-Wesson critical value β c for optimised pressure profiles have been produced at low toroidal fields (B T =1.5T). In the second type, extremely high pressure gradients have been produced in the plasma core through pellet injection in the current rise phase of the discharge followed by strong additional heating. The stability of these discharges has been studied with the stability code HBT coupled to the equilibrium identification code IDENTC. The equilibrium pressure and diamagnetic function profiles are determined in IDENTC by an optimisation procedure to fit the external magnetic measurements. The resulting pressure profile in the equatorial plane is then compared with the profile derived from 'direct' measurements, i.e. electron density and temperature profiles measured by the LIDAR diagnostic system, ion-temperature profile measured by the charge-exchange diagnostic system, and ion density profile calculated from the Z eff and electron density profiles. Furthermore, the value of the safety factor q on axis is compared with that determined from polarimetry. When good agreement is found, the output data from IDENTC is passed directly to HBT to carry out the stability analysis. When there is not a good agreement, as in the case of pellet discharges with highly peaked pressure profiles, the equilibrium is reevaluated using the 'experimental' profile and the data from polarimetry. (author) 6 refs., 4 figs

  3. Atmospheric sampling glow discharge ionization source

    Science.gov (United States)

    McLuckey, S.A.; Glish, G.L.

    1989-07-18

    An atmospheric sampling glow discharge ionization source that can be used in combination with an analytical instrument which operates at high vacuum, such as a mass spectrometer. The atmospheric sampling glow discharge ionization source comprises a chamber with at least one pair of electrodes disposed therein, an inlet for a gaseous sample to be analyzed and an outlet communicating with an analyzer which operates at subatmospheric pressure. The ionization chamber is maintained at a pressure below atmospheric pressure, and a voltage difference is applied across the electrodes to induce a glow discharge between the electrodes, so that molecules passing through the inlet are ionized by the glow discharge and directed into the analyzer. The ionization source accepts the sample under atmospheric pressure conditions and processes it directly into the high vacuum instrument, bridging the pressure gap and drawing off unwanted atmospheric gases. The invention also includes a method for analyzing a gaseous sample using the glow discharge ionization source described above. 3 figs.

  4. Research on Modern Gas Discharge Light Sources

    Science.gov (United States)

    Born, M.; Markus, T.

    This article gives an overview of today's gas discharge light sources and their application fields with focus on research aspects. In Sect. 15.1 of this chapter, an introduction to electric light sources, the lighting market and related research topics is outlined. Due to the complexity of the subject, we have focused on selected topics in the field of high intensity discharge (HID) lamps since these represent an essential part of modern lamp research. The working principle and light technical properties of HID lamps are described in Sect. 15.2. Physical and thermochemical modelling procedures and tools as well as experimental analysis are discussed in Sects. 15.3 and 15.4, respectively. These tools result in a detailed scientific insight into the complexity of real discharge lamps. In particular, analysis and modelling are the keys for further improvement and development of existing and new products.

  5. Technological ion sources based on the vacuum arc discharge

    CERN Document Server

    Bugaev, S P; Oks, E M; Yushkov, G Y; Shchanin, P M; Braun, Y

    2001-01-01

    The Titan service ion sources are designed to generate wide-aperture high-current ion beams of gases or metals, as well as, mixed two-component gas and metal ion beams with the controllable ratio of components in a beam. This possibility is achieved via integration of two discharge systems in a source discharge system. To generate metal ions one uses a vacuum, arc discharge, while gas ions are generated by a low pressure contracted arc discharge with cold cathodes. The paper describes operation of these sources, their design, technical characteristics, peculiarities of their operation and application fields

  6. Operation of Ferroelectric Plasma Sources in a Gas Discharge Mode

    International Nuclear Information System (INIS)

    Dunaevsky, A.; Fisch, N.J.

    2004-01-01

    Ferroelectric plasma sources in vacuum are known as sources of ablative plasma, formed due to surface discharge. In this paper, observations of a gas discharge mode of operation of the ferroelectric plasma sources (FPS) are reported. The gas discharge appears at pressures between approximately 20 and approximately 80 Torr. At pressures of 1-20 Torr, there is a transition from vacuum surface discharge to the gas discharge, when both modes coexist and the surface discharges sustain the gas discharge. At pressures between 20 and 80 Torr, the surface discharges are suppressed, and FPS operate in pure gas discharge mode, with the formation of almost uniform plasma along the entire surface of the ceramics between strips. The density of the expanding plasma is estimated to be about 1013 cm-3 at a distance of 5.5 mm from the surface. The power consumption of the discharge is comparatively low, making it useful for various applications. This paper also presents direct measurements of the yield of secondary electron emission from ferroelectric ceramics, which, at low energies of primary electrons, is high and dependent on the polarization of the ferroelectric material

  7. Estimating contaminant discharge rates from stabilized uranium tailings embankments

    International Nuclear Information System (INIS)

    Weber, M.F.

    1986-01-01

    Estimates of contaminant discharge rates from stabilized uranium tailings embankments are essential in evaluating long-term impacts of tailings disposal on groundwater resources. Contaminant discharge rates are a function of water flux through tailings covers, the mass and distribution of tailings, and the concentrations of contaminants in percolating pore fluids. Simple calculations, laboratory and field testing, and analytical and numerical modeling may be used to estimate water flux through variably-saturated tailings under steady-state conditions, which develop after consolidation and dewatering have essentially ceased. Contaminant concentrations in water discharging from the tailings depend on tailings composition, leachability and solubility of contaminants, geochemical conditions within the embankment, tailings-water interactions, and flux of water through the embankment. These concentrations may be estimated based on maximum reported concentrations, pore water concentrations, extrapolations of column leaching data, or geochemical equilibria and reaction pathway modeling. Attempts to estimate contaminant discharge rates should begin with simple, conservative calculations and progress to more-complicated approaches, as necessary

  8. 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.}

  9. Ballooning stability analysis of JET H-mode discharges

    International Nuclear Information System (INIS)

    O'Brien, D.P.; Galvao, R.; Keilhacker, M.; Lazzaro, E.; Watkins, M.L.

    1989-01-01

    Previous studies of the stability of a large aspect ratio model equilibrium to ideal MHD ballooning modes have shown that across the bulk of the plasma there exist two marginally stable values of the pressure gradient parameter α. These define an unstable zone which separates the first (small α) stable region from the second (large α) stable region. Close to the separatrix, however, the first and second regions can coalesce when the surface averaged current density, Λ, exceeds a critical value. The plasma in this region is then stable to ballooning modes at all values of the pressure gradient. In this paper we extend these results to JET H-mode equilibria using a finite aspect ratio ballooning formalism, and assess the relevance of ideal ballooning stability in these discharges. In particular we analyse shot 15894 at time 56 sec. which is 1.3 s into the H-phase. (author) 4 refs., 4 figs

  10. Multifunctional bulk plasma source based on discharge with electron injection.

    Science.gov (United States)

    Klimov, A S; Medovnik, A V; Tyunkov, A V; Savkin, K P; Shandrikov, M V; Vizir, A V

    2013-01-01

    A bulk plasma source, based on a high-current dc glow discharge with electron injection, is described. Electron injection and some special design features of the plasma arc emitter provide a plasma source with very long periods between maintenance down-times and a long overall lifetime. The source uses a sectioned sputter-electrode array with six individual sputter targets, each of which can be independently biased. This discharge assembly configuration provides multifunctional operation, including plasma generation from different gases (argon, nitrogen, oxygen, acetylene) and deposition of composite metal nitride and oxide coatings.

  11. Gas-discharge sources with charged particle emission from the plasma of glow discharge with a hollow cathode

    CERN Document Server

    Semenov, A P

    2001-01-01

    One studied properties of a magnetron discharge with a cold hollow and uncooled rod cathodes. One demonstrated the dominant effect of thermoelectron emission of a rod cathode heated in a discharge on characteristics of discharge and on emission properties of a gas-discharge plasma and the possibility pf a smooth transition of glow discharge to diffusion mode of arc discharge combustion. Paper describes sources of ions and electrons with improved physical and generalized design and engineering parameters. One shows the promise of the electrode structure of a hollow cathode magnetron discharge to be used as a source, in particular, of the atomic hydrogen and of atom flow of a working rod cathode

  12. Electrical discharge light sources: a challenge for the future

    International Nuclear Information System (INIS)

    Zissis, G.

    2001-01-01

    The first electric powder lamp operated that 150 years ago, since then the evolution of light sources is astonishing. Today, more than 10 % of the global electric power produced worldwide serve fore light production from several billions lamps. Since last three decades incandescent lamps are gradually replaced by more energy efficient discharge lamps. In parallel, new generation of light emitting diodes, producing bright colours (including white) with luminous efficacy challenging even discharge lamps, appeared in past years. The objective of this paper is to focus on the state of art in the domain of light sources and discuss the challenges for the near future. (author)

  13. [The glow discharge as an atomization and ionization source

    International Nuclear Information System (INIS)

    1990-01-01

    This is to summarize the research progress in this project at the University of Florida over the past 13 months. In keeping with the directions of the Federal Demonstration Project, the report will be brief, presenting an overview of the major findings. We have continued the study of the glow discharge, primarily as an ionization source for elemental analysis. Glow discharge interest continues to grow in the analytical chemistry community as evidenced by the number of special symposia at major conferences, by the new researchers entering the field, and by the introduction of new instrumentation. There is little doubt that glow discharge mass spectrometry, for example, is now a major technique in the elemental analysis of solids

  14. Confined discharge plasma sources for Z-pinch experiments

    International Nuclear Information System (INIS)

    Hinshelwood, D.D.; Goodrich, P.J.; Mehlman, G.; Scherrer, V.E.; Stephanakis, S.J.; Young, F.C.

    1989-01-01

    The authors report their investigation Z-pinch implosions on the NRL Gamble II generator using metallic sources of sodium and aluminum, and non-metallic source of sodium (NaF), magnesium (MgF 2 ), and aluminum (Al 2 0 3 ). For 1 MA driving currents, peak Κ-shell radiated powers of about 100 GW and energies of about 1.5 kj have been obtained with both pure aluminum and NaF implosions. The aluminum results are comparable to those in previous Gamble II experiments with aluminum wire arrays. Confined discharge sources have been used to generate tens of GW in the Na Heα pump line and flourescence of the neon has been observed. The effects of nozzle shape and size, chamber diameter, amount of fuse material, and confined discharge current have been investigated in Gamble II implosion experiments. These studies indicate that confined discharge sources are capable of supplying significantly more material than required for implosions at the 1 MA level, so that this technique could be extended to higher current generators

  15. LMFBR source term experiments with rupture disk discharge under sodium

    International Nuclear Information System (INIS)

    Minges, J.; Schuetz, W.

    1993-05-01

    In the frame of the KfK research program FAUST, contributions are given to the assessment of the instantaneous source term in case of an LMFBR loss-of-flow accident with expanding fuel or sodium vapour. The main goal of the program is to achieve information, mainly by experiments, on the retention capability of the primary sodium pool for fuel and fission products. For that purpose, it is necessary to investigate the interaction of bubble and aerosol behaviour after a pressure discharge, and the subsequent aerosol transport. After a series of water tests (FAUST-1), rupture disk discharge tests under 500 C sodium up to 3.81 MPa were performed during the phase FAUST-2 with the two test facilities 2A (about 2 liters of sodium) and 2B (about 200 liters of sodium). The discharge tests were performed with pressurized argon gas and admixtures of the simulation materials Cs, Csl, Nal, l 2 , SrO, and UO 2 . Cs was a liquid, l 2 vapour, and all other substances solid particles. Besides UO 2 , non-radioactive material was used (natural isotopes). The retention capability of liquid sodium is expressed by retention factors RF. In general, RF is defined as the mass ratio of discharged amount, and the amount which is detected in the cover gas for the relevant species. From sampling immediately after the discharge, the instantaneous retention factors are deduced. From retarded sampling, the 'delayed factors' follow. High pressure discharge creates two important removal mechanisms, namely 'impaction by inertia relative to the bubble oscillations' and 'wash-out by sedimentation of entrained sodium droplets'. On the other hand, the retention of particles enclosed in a buoyantly rising bubble is significantly smaller. (orig.) [de

  16. Stability and Confinement Properties of Auxiliary Heated NSTX Discharges

    Energy Technology Data Exchange (ETDEWEB)

    J.E. Menard; R.E.Bell; C. Bourdelle; D.S. Darrow; E.D. Fredrickson; D.A. Gates; L.R. Grisham; S.M. Kaye; B.P. LeBlanc; R. Maingi; S.S. Medley; D. Mueller; F. Paoletti; S.A. Sabbagh; D. Stutman; D.W. Swain; J.R. Wilson; M.G. Bell; J.M. Bialek; C.E.Bush; J.C. Hosea; D.W. Johnson; R. Kaita; H.W. Kugel; R.J. Maqueda; M. Ono; Y-K.M. Peng; C.H. Skinner; V.A. Soukhanovskii; E.J. Synakowski; G. Taylor; G.A. Wurden; and S.J. Zweben

    2001-07-05

    The National Spherical Torus Experiment (NSTX) is a spherical tokamak with nominal plasma major radius R(subscript ''0'') = 0.85 m, minor radius a = 0.66 m, and aspect ratio A > 1.28. Typical discharge parameters are plasma current I (subscript ''p'') = 0.7-1.4 MA, toroidal magnetic field B(subscript ''t0'') = 0.25-0.45 Tesla at major radius R(subscript ''0''), elongation = 1.7-2.2, triangularity 0.3-0.5, line-average electron density = 2-5 x 10(superscript ''19'') m(superscript ''-3''), electron temperature T(subscript ''e'')(0) = 0.5-1.5 keV, and ion temperature T(subscript ''i'')(0) = 0.5-2 keV. The NSTX auxiliary heating systems can routinely deliver 4.5 MW of 80-keV deuterium neutral beams and 3 MW of 30-MHz high-harmonic fast-wave power. Kinetic profile diagnostics presently include a 10-channel, 30-Hz multipulse Thomson scattering system (MPTS), a 17-channel charge-exchange recombination spectroscopy (CHERS) system, a 48-chord ultra-soft X-ray (USXR) array, and a 15-chord bolometry array. Initial experiments utilizing auxiliary heating on NSTX have focused on MHD stability limits, confinement trends, studying H-mode characteristics, and performing initial power balance calculations.

  17. Discharge plasmas as EUV Sources for Future Micro Lithography

    Science.gov (United States)

    Kruecken, Thomas

    2007-08-01

    Future extreme ultraviolet (EUV) lithography will require very high radiation intensities in a narrow wavelength range around 13.5 nm, which is most efficiently emitted as line radiation by highly ionized heavy particles. Currently the most intense EUV sources are based on xenon or tin gas discharges. After having investigated the limits of a hollow cathode triggered xenon pinch discharge Philips Extreme UV favors a laser triggered tin vacuum spark discharge. Plasma and radiation properties of these highly transient discharges will be compared. Besides simple MHD-models the ADAS software package has been used to generate important atomic and spectral data of the relevant ion stages. To compute excitation and radiation properties, collisional radiative equilibria of individual ion stages are computed. For many lines opacity effects cannot be neglected. In the xenon discharges the optical depths allow for a treatment based on escape factors. Due to the rapid change of plasma parameters the abundancies of the different ionization stages must be computed dynamically. This requires effective ionization and recombination rates, which can also be supplied by ADAS. Due to very steep gradients (up to a couple orders of magnitude per mm) the plasma of tin vacuum spark discharges is very complicated. Therefore we shall describe here only some technological aspects of our tin EUV lamp: The electrode system consists of two rotating which are pulled through baths of molten tin such that a tin film remains on their surfaces. With a laser pulse some tin is ablated from one of the wheels and travels rapidly through vacuum towards the other rotating wheel. When the tin plasma reaches the other electrodes it ignites and the high current phase starts, i.e. the capacitor bank is unloaded, the plasma is pinched and EUV is radiated. Besides the good spectral properties of tin this concept has some other advantages: Erosion of electrodes is no severe problem as the tin film is

  18. PREFACE: Diagnostics for electrical discharge light sources: pushing the limits Diagnostics for electrical discharge light sources: pushing the limits

    Science.gov (United States)

    Zissis, Georges; Haverlag, Marco

    2010-06-01

    Light sources play an indispensable role in the daily life of any human being. Quality of life, health and urban security related to traffic and crime prevention depend on light and on its quality. In fact, every day approximately 30 billion electric light sources operate worldwide. These electric light sources consume almost 19% of worldwide electricity production. Finding new ways to light lamps is a challenge where the stakes are scientific, technological, economic and environmental. The production of more efficient light sources is a sustainable solution for humanity. There are many opportunities for not only enhancing the efficiency and reliability of lighting systems but also for improving the quality of light as seen by the end user. This is possible through intelligent use of new technologies, deep scientific understanding of the operating principles of light sources and knowledge of the varied human requirements for different types of lighting in different settings. A revolution in the domain of light source technology is on the way: high brightness light emitting diodes arriving in the general lighting market, together with organic LEDs (OLEDs), are producing spectacular advances. However, unlike incandescence, electrical discharge lamps are far from disappearing from the market. In addition, new generations of discharge lamps based on molecular radiators are becoming a reality. There are still many scientific and technological challenges to be raised in this direction. Diagnostics are important for understanding the fundamental mechanisms taking place in the discharge plasma. This understanding is an absolute necessity for system optimization leading to more efficient and high quality light sources. The studied medium is rather complex, but new diagnostic techniques coupled to innovative ideas and powerful tools have been developed in recent years. This cluster issue of seven papers illustrates these efforts. The selected papers cover all domains, from

  19. Ion source using a hollow cathode discharge system and especially, particle accelerator comprising said source

    International Nuclear Information System (INIS)

    Mourier, Georges.

    1975-01-01

    An ion source provided with a hollow cathode discharge system is presented. The ion extraction system is designed in view of generating a beam directed towards a point of use located far from the point of ion production. Said source essentially comprises two cathodes facing each other, an anode at a continuous voltage with respect to the cathodes, a heated filament beyond the cathode on the path of the extracted beam, and a grid between said filament and cathode. The ion extraction is limited to a certain portion of the ions present inside the plasma, so as the discharge to continue to be sustained by itself. For that purpose pierced cathodes are used, with a transparency (the ratio of the hole area to the whole cathode area) not much higher than 50% [fr

  20. MHD stability of runaway electron discharge in tokamaks

    International Nuclear Information System (INIS)

    Wakatani, M.

    1978-04-01

    A runaway current concentrating in the central region has stabilizing effects on kink and tearing instabilities on the basis of a model in which the runaway current is assumed rigid. The Kruskal-Shafranov limit (iota(a) = iota sub(σ(a) + iota sub( b)(a) <= 1) disappears for iota sub(σ(a) <= 0.2 in the case of parabolic profiles of both the runaway current and the conduction current. Here iota sub(σ)(a) is a rotational transform due to the conduction current and iota sub( b)(a) is a rotational transform due to the runaway current. (auth.)

  1. Technological plasma source equipped with combined system of vacuum-arc discharge initiation

    International Nuclear Information System (INIS)

    Sysoev, Yu.O.

    2013-01-01

    The construction and the operation principle of erosion plasma source with a three-stage system of vacuum-arc discharge excitation is described. As first two step was used the modified contactless start system with plasma injector, which was widely used in standard plasma sources of the ''Bulat'' systems. The operation principle of the third stage was based on the transition of glow discharge to arc discharge. Coordinated operation of three stages during various stages of coating deposition provided significant increasing of service life and reliability of the system of vacuum-arc discharge initiation and extended the functionality of the plasma source

  2. Quantitative Analysis of Electrochemical and Electrode Stability with Low Self-Discharge Lithium-Sulfur Batteries.

    Science.gov (United States)

    Chung, Sheng-Heng; Han, Pauline; Manthiram, Arumugam

    2017-06-21

    The viability of employing high-capacity sulfur cathodes in building high-energy-density lithium-sulfur batteries is limited by rapid self-discharge, short shelf life, and severe structural degradation during cell resting (static instability). Unfortunately, the static instability has largely been ignored in the literature. We present in this letter a long-term self-discharge study by quantitatively analyzing the control lithium-sulfur batteries with a conventional cathode configuration, which provides meaningful insights into the cathode failure mechanisms during resting. Utilizing the understanding obtained with the control cells, we design and present low self-discharge (LSD) lithium-sulfur batteries for investigating the long-term self-discharge effect and electrode stability.

  3. Effect of a sound wave on the stability of an argon discharge

    International Nuclear Information System (INIS)

    Galechyan, G.A.; Karapetyan, D.M.; Tavakalyan, L.B.

    1992-01-01

    The effect of a sound wave on the stability of the positive column of an argon discharge has been studied experimentally in the range of pressures from 40 to 180 torr and discharge currents from 40 to 110 mA in a tube with an interior diameter of 9.8 cm. It is shown that, depending on the intensity of the sound wave and the discharge parameters, sound can cause the positive column either to contract or to leave the contracted state. The electric field strength has been measured as a function of the sound intensity. An analogy between the effect of sound and that of longitudinal pumping of the gas on the argon discharge parameters has been established. The radial temperature of the gas has been studied in an argon discharge as a function of the sound intensity for different gas pressures. A direct relationship has been established between the sign of the detector effect produced by a sound wave in a discharge and the processes of contraction and filamentation of a discharge. 11 refs., 4 figs., 1 tab

  4. Stabilized operation of the Spallation Neutron Source radio-frequency quadrupole

    Directory of Open Access Journals (Sweden)

    Sang-ho Kim

    2010-07-01

    Full Text Available The Spallation Neutron Source (SNS radio-frequency quadrupole (RFQ had resonance control instabilities at duty factors higher than approximately 4%. Systematic investigations have been carried out to understand the cause of the instability and to ensure the operational stability of the RFQ. The most critical source of the instability is revealed to be an interaction between hydrogen released by beam bombardments and the RFQ rf field resulting in a discharge, which consumes additional rf power and could cause the RFQ to operate in an unstable region. This paper reports improvement of the SNS RFQ operational stability based on the findings during the SNS operation.

  5. 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.

  6. Characterization of neutral beam source using dc cold cathode discharge and its application processes

    International Nuclear Information System (INIS)

    Ichiki, Katsunori; Hatakeyama, Masahiro

    2008-01-01

    Fast atom beam (FAB) sources using dc cold cathode discharge, comprising parallel plate electrodes and thick carbon plate cathodes with multiple beam extracting apertures, were developed to generate parallel and straight energetic neutral beams for precise etching of three-dimensional microstructures consisting of insulating materials. Conventional FAB sources and their applications are briefly reviewed, and the advantages of newly developed FAB sources and new applications are introduced. By using SF 6 gas, a precise etching of quartz glass with an etch rate of 30 nm min -1 , a uniformity of within 4% (P-V) in Oe76 mm, vertical etch profile, smooth etch surface and long-term etch rate stability over 250 min were realized. The neutralization coefficient and the beam current density were also measured using a secondary electron method and a pulse-counting method, making it possible to measure the neutralization coefficient without referring to databases for secondary electron yields. A neutralization coefficient of 98% was obtained at maximum, although, under practical etching conditions, the neutralization coefficient is less than 70%. By comparing the results of the simple model calculation with the experimental data, it was determined that the neutralization mechanism was dominated by charge transfer. The importance of neutralization in a process chamber is also discussed

  7. Gas-discharge plasma sources for nonlocal plasma technology

    International Nuclear Information System (INIS)

    Demidov, V. I.; DeJoseph, C. A. Jr.; Simonov, V. Ya.

    2007-01-01

    Nonlocal plasma technology is based on the effect of self-trapping of fast electrons in the plasma volume [V. I. Demidov, C. A. DeJoseph, Jr., and A. A. Kudryavtsev, Phys. Rev. Lett. 95, 215002 (2006)]. This effect can be achieved by changing the ratio of fast electron flux to ion flux incident on the plasma boundaries. This in turn leads to a significant change in plasma properties and therefore can be useful for technological applications. A gas-discharge device which demonstrates control of the plasma properties by this method is described

  8. Radiological exposure within the range of several sources of discharge

    International Nuclear Information System (INIS)

    Ehrlich, H.G.; Vogt, K.J.

    1978-01-01

    There is presented the multi-source computing model SESAM. It is subdivided into the parts pollutant dispersion, superposition, and dose calculation. By means of it all questions relevant in connection with multi-source problems can be dealt with. The model was illustrated by means of two examples of calculation. (orig./HP) 891 HP/orig.- 892 MB [de

  9. Control of stochastic sensitivity in a stabilization problem for gas discharge system

    Energy Technology Data Exchange (ETDEWEB)

    Bashkirtseva, Irina [Ural Federal University, Lenina, 51, Ekaterinburg, 620000 (Russian Federation)

    2015-11-30

    We consider a nonlinear dynamic stochastic system with control. A problem of stochastic sensitivity synthesis of the equilibrium is studied. A mathematical technique of the solution of this problem is discussed. This technique is applied to the problem of the stabilization of the operating mode for the stochastic gas discharge system. We construct a feedback regulator that reduces the stochastic sensitivity of the equilibrium, suppresses large-amplitude oscillations, and provides a proper operation of this engineering device.

  10. Final NPDES General Permit for New and Existing Sources and New Dischargers

    Science.gov (United States)

    Final NPDES General Permit for New and Existing Sources and New Dischargers in the Offshore Subcategory of the Oil and Gas Extraction Category for the Western Portion of the Outer Continental Shelf of the Gulf of Mexico (PDF)

  11. Renewable source controls for grid stability.

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Raymond Harry; Elliott, Ryan Thomas; Neely, Jason C.; Silva Monroy, Cesar Augusto; Schoenwald, David Alan; Grant, Lisa

    2012-12-01

    The goal of this study was to evaluate the small signal and transient stability of the Western Electric- ity Coordinating Council (WECC) under high penetrations of renewable energy, and to identify control technologies that would improve the system performance. The WECC is the regional entity responsible for coordinating and promoting bulk electric system reliability in the Western Interconnection. Transient stability is the ability of the power system to maintain synchronism after a large disturbance while small signal stability is the ability of the power system to maintain synchronism after a small disturbance. Tran- sient stability analysis usually focuses on the relative rotor angle between synchronous machines compared to some stability margin. For this study we employed generator speed relative to system speed as a metric for assessing transient stability. In addition, we evaluated the system transient response using the system frequency nadir, which provides an assessment of the adequacy of the primary frequency control reserves. Small signal stability analysis typically identi es the eigenvalues or modes of the system in response to a disturbance. For this study we developed mode shape maps for the di erent scenarios. Prony analysis was applied to generator speed after a 1.4 GW, 0.5 second, brake insertion at various locations. Six di erent WECC base cases were analyzed, including the 2022 light spring case which meets the renewable portfolio standards. Because of the di culty in identifying the cause and e ect relationship in large power system models with di erent scenarios, several simulations were run on a 7-bus, 5-generator system to isolate the e ects of di erent con gurations. Based on the results of the study, for a large power system like the WECC, incorporating frequency droop into wind/solar systems provides a larger bene t to system transient response than replacing the lost inertia with synthetic inertia. From a small signal stability

  12. Spectroscopic measurements of an H- ion source discharge

    International Nuclear Information System (INIS)

    Keller, R.; Smith, H.V. Jr.

    1985-01-01

    Spectral emission lines from an H - Penning surface-plasma source (SPS), the 4X source, are examined in the visible and near ultraviolet. Electron distribution temperatures are deduced from integral line-strength measurements. These temperatures are surprisingly low, about 0.5 eV. Electron density values of about 1.5 x 10 14 cm -3 and H-atom energies between 2 and 2.6 eV are determined from the measured Balmer-line profiles. Assuming the H - energy is identical to the H-atom energy, an emittance limit of 0.006 π x cm x mrad is deduced for this source with a 5.4-mm aperture

  13. Modeling Tool to Quantify Metal Sources in Stormwater Discharges at Naval Facilities (NESDI Project 455)

    Science.gov (United States)

    2014-06-01

    demonstration/validation project to assess the use of the urban stormwater model Windows Source Loading and Management Model (WinSLAMM) to characterize...the urban stormwater model Windows Source Loading and Management Model (WinSlamm) to characterize sources of copper and zinc in storm runoff at Navy...are ubiquitous contaminants found in stormwater discharges in urban and industrialized areas. These contaminants originate from a variety of sources

  14. A High Reliability Frequency Stabilized Semiconductor Laser Source Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA needs high stability laser source of 1W output power for Lidar applications. Princeton Optronics has developed ultra-stable, narrow linewidth diode pumped solid...

  15. Organic impurities harmful to arc discharge in multi-ampere duo-pigatron ion source

    International Nuclear Information System (INIS)

    Peng Zhudong; Wang Shouhu; Chen Miaosun; Huang Chongan; Ge Yishan; Fu Peng; E Maohuai

    1989-01-01

    Besides mechanism producing plasmain Duo-Pigatron Ion Source, the main purpose of this paper is to introduce the problem on arc discharge exhaustion caused by oil pollution. The problem was discovered during developing a 15 cm Duo-Pigatron Ion Source. The paper also describes its physical process

  16. The nature and source of irregular discharges to stormwater entering Sydney estuary, Australia

    International Nuclear Information System (INIS)

    Beck, H.J.; Birch, G.F.

    2014-01-01

    Irregular discharges of polluted stormwater into drainage systems during base flow (no rainfall) result in acute ecological impacts within fluvial and estuarine environments. In this study, metal and TSS concentrations were significantly more variable during business hours of weekdays (i.e. high-business activity) than weekends/public holidays (i.e. low-business activity) within three highly-urbanised catchments of Sydney estuary (Australia), as determined by analysing multivariate dispersion (PERMDISP). Concentrations of TSS and all metals analysed (Al, Ca, Cu, Fe, Mg, Pb and Zn) were also significantly greater during high- than low-business periods within at least one of the three catchments. In no case were concentrations significantly higher during low- than high-business periods. This pattern of contamination supports the hypothesis that commercial and industrial sources are major contributors of irregular discharges of contamination to Sydney estuary. Irregular discharges and consequential ecological impacts may be effectively reduced in this environment by focussing management efforts on these activities. - Highlights: • Irregular discharges of pollution have acute impacts on aquatic ecosystems. • These discharges were thought to be made during low activity periods, such as night. • Pollution was more concentrated and erratic during high- than low-business periods. • Timing of pollution suggests commercial and industrial activities are major sources. • Discharges effectively reduced by managing commercial and industrial activities. - Previously unreported irregular, illegal discharges of polluted stormwater released to estuaries result in acute ecological impacts and are potentially related to commercial/industrial activities

  17. Programmable current source for diode lasers stabilized optical fiber

    International Nuclear Information System (INIS)

    Gomez, J.; Camas, J.; Garcia, L.

    2012-01-01

    In this paper, we present the electronic design of a programmable stabilized current source. User can access to the source through a password, which, it has a database with the current and voltage operating points. This source was successfully used as current source in laser diode in optical fiber sensors. Variations in the laser current were carried out by a monitoring system and a control of the Direct Current (DC), which flowing through a How land source with amplifier. The laser current can be stabilized with an error percent of ± 1 μA from the threshold current (Ith) to its maximum operation current (Imax) in DC mode. The proposed design is reliable, cheap, and its output signal of stabilized current has high quality. (Author)

  18. Hydrogen isotopic spectral determination in inert gases with the use of light source with contracted discharge

    International Nuclear Information System (INIS)

    Nemets, V.M.; Solov'ev, A.A.

    1981-01-01

    Isotopic-spectral technique for hydrogen determination in helium, neon and argon is developed. It employs a contracted high-frequency discharge as a light source to decrease the distorting effect. of a dummy signal and the ''memory'' effect of the discharge tube. The discharge is realized in a quartz tube approximately 7 mm dia. and gas pressure in it approximately 6x10 4 Pa. The analysis technique comprises sampling of gas, dosed introduction of deuterium into the sample, selection of a mixture portion into the discharge tube, spectroscopic determination of hydrogen isotope ratio and calculation of the sought for hydrogen concentration. The lower boundary of the determined concentrations of hydrogen constitutes 7x10 - 5 , 2x10 - 4 and 4x10 - 4 volumetric per cent in helium, neon, and argon, respectively

  19. Monitoring physical properties of a submarine groundwater discharge source at Kalogria Bay, SW Peloponnissos, Greece

    Directory of Open Access Journals (Sweden)

    Papathanassiou E.

    2012-04-01

    Full Text Available An impressive SGD in Kalogria Bay (SW Peloponnissos was surveyed for the first time in 2006, revealing the existence of 2 major and 2 minor point sources of freshwater (salinity ~l-2; the discharge was ~ 1000 m3 h−1. The major point source was located in a karstic cavity at 25 m depth. In July 2009, and for a period of one year, the site was monitored intensively. During summer, the underwater discharge was not very strong, the water was flowing from many dispersed points, and salinity range was 20–36. During autumn and winter, flow velocity increased considerably (> 1 m s−1, and the SGDs discharged water of low salinity (< 2. Gradually, the smaller SGDs ceased their operation, and the major SGD emanated brackish water during spring and summer, thus hampering the possibilities of freshwater exploitation, in a touristic area which suffers from great aridity and water demand is high during summer.

  20. Ion source based on Penning discharge for production of doubly charged helium ions

    Directory of Open Access Journals (Sweden)

    V. I. Voznyi

    2017-11-01

    Full Text Available The article presents the results of operation of ion source with Penning discharge developed in the IAP of NAS of Ukraine to produce doubly charged helium ions He2+ beam and to increase the energy of accelerated ions up to 3.2 MeV. This energy is necessary for ERDA channel when measuring hydrogen concentration in the structural materials used in nuclear engineering. The ion source parameters are the following: discharge voltage is 6 kV, discharge current is 0.8 - 1.2 mA, the current of singly charged helium ions He+ 24 μA, the current of doubly charged helium ions He2+ 0.5 μA.

  1. Using Soluble Reactive Phosphorus and Ammonia to Identify Point Source Discharge from Large Livestock Facilities

    Science.gov (United States)

    Borrello, M. C.; Scribner, M.; Chessin, K.

    2013-12-01

    A growing body of research draws attention to the negative environmental impacts on surface water from large livestock facilities. These impacts are mostly in the form of excessive nutrient loading resulting in significantly decreased oxygen levels. Over-application of animal waste on fields as well as direct discharge into surface water from facilities themselves has been identified as the main contributor to the development of hypoxic zones in Lake Erie, Chesapeake Bay and the Gulf of Mexico. Some regulators claim enforcement of water quality laws is problematic because of the nature and pervasiveness of non-point source impacts. Any direct discharge by a facility is a violation of permits governed by the Clean Water Act, unless the facility has special dispensation for discharge. Previous research by the principal author and others has shown runoff and underdrain transport are the main mechanisms by which nutrients enter surface water. This study utilized previous work to determine if the effects of non-point source discharge can be distinguished from direct (point-source) discharge using simple nutrient analysis and dissolved oxygen (DO) parameters. Nutrient and DO parameters were measured from three sites: 1. A stream adjacent to a field receiving manure, upstream of a large livestock facility with a history of direct discharge, 2. The same stream downstream of the facility and 3. A stream in an area relatively unimpacted by large-scale agriculture (control site). Results show that calculating a simple Pearson correlation coefficient (r) of soluble reactive phosphorus (SRP) and ammonia over time as well as temperature and DO, distinguishes non-point source from point source discharge into surface water. The r value for SRP and ammonia for the upstream site was 0.01 while the r value for the downstream site was 0.92. The control site had an r value of 0.20. Likewise, r values were calculated on temperature and DO for each site. High negative correlations

  2. Initial operation of the CW 8X H- ion source discharge

    International Nuclear Information System (INIS)

    Smith, H.V. Jr.; Allison, P.; Geisik, C.; Schmitt, D.R.; Schneider, J.D.; Stelzer, J.E.

    1993-01-01

    A pulsed 8Χ source was built and the H - beam current, emittance, and power efficiency were measured. These results were promising, so a cooled, dc version designed for operation at arc power levels up to 30 kW was built. Testing of the CW 8Χ source discharge is underway. The design dc power loading on the cathode surface is 900 W/cm 2 , considerably higher than achieved in any pervious Penning surface-plasma source (SPS). Thus, the electrode surfaces are cooled with pressurized, hot water. We describe the source and present the initial operating experience and arc test results

  3. Emission Spectroscopy of the 4X Source Discharge With and Without N2 Gas

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Horace Vernon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-14

    This tech note summarizes the December, 1988 emission spectroscopy measurements made on the 4X source discharge with and without N₂ gas added to the H + Cs discharge. This study is motivated by the desire to understand why small amounts of N₂ gas added to the source discharge results in a reduction in the H⁻ beam noise. The beneficial effect of N₂ gas on H⁻ beam noise was first discovered by Bill Ingalls and Stu Orbesen on the ATS SAS source. For the 4X source the observed effect is that when N2 gas is added to the discharge the H⁻ beam noise is reduced about a factor of 2.

  4. New type of discharge-produced plasma source for extreme ultraviolet based on liquid tin jet electrodes

    NARCIS (Netherlands)

    Koshelev, K.N.; Krivtsun, V.M.; Ivanov, V.; Yakushev, O.; Chekmarev, A.; Koloshnikov, V.; Snegirev, E.; Medvedev, Viacheslav

    2012-01-01

    A new approach for discharge-produced plasma (DPP) extreme ultraviolet (EUV) sources based on the usage of two liquid metallic alloy jets as discharge electrodes has been proposed and tested. Discharge was ignited using laser ablation of one of the cathode jets. A system with two jet electrodes was

  5. Stabilization of premixed lean methane-air combustion using dielectric barrier discharge with low pollutant emissions

    Science.gov (United States)

    Ono, Ryo; Ogura, Kazuaki; Mogi, Toshio

    2017-09-01

    Catalytic combustion is a promising technology to stabilize lean combustion with low pollutant emissions. Catalytic combustion has been applied to gas turbine combustors; however, some drawbacks of this technology remain to be addressed. In this work, a new concept is demonstrated to overcome the problems of catalytic combustion by using dielectric barrier discharge (DBD) instead of a catalyst. A premixed lean methane-air mixture preheated to 400 °C with an equivalence ratio of 0.45 is flowed through the DBD reactor under atmospheric pressure. Almost complete combustion is achieved with a DBD power of 0.7% of the net calorific value of the mixture. The exhaust emissions are NO = 20 ppm, NO2 = 2 ppm, CO = 2 ppm, and HC \\cong 0 ppm. This work demonstrates that DBD-assisted combustion is a potential alternative to catalytic combustion.

  6. Pulse current as a current source with charge-discharge capacitor method for making magnet

    International Nuclear Information System (INIS)

    Handoko, Djati; Farhad, Hasan; Kurniawan, Budhy; Manaf, Azwar

    2002-01-01

    Have been made and analyzed a high current source instrument with charge-discharge capacitor method. A 0.25 kA pulse current have been produce by this instrument. The instrument has 2 capacitors in parallel configuration with 3300 μF/350 V capacitance. Charge and discharge is controlled by closing/opening SCR and adjustable with timer. Analyze has been done for change of voltage in capacitor comparing with time to reach that. The result showed that both of them have linear relationship. The instrument has been done for making magnet based on Nd-Fe-B and SmCo materials and produced better than electromagnet method

  7. Ion source for IMS based on wire-to-plate corona discharge

    Science.gov (United States)

    Xia, Qing; Zhang, Yu; Ouyang, Jiting

    2017-08-01

    In this paper, an ion source based on wire-to-plate corona is developed for Ion Mobility Spectrometer (IMS). The characteristics of the corona discharge and the ion current detected on Faraday plate are investigated under different electrode spacing and voltage. The effect of voltage polarity is also studied. The features of this new designed ion source are compared with that of point-to-plate corona. The results show that the present IMS prototype machine can provide a much larger value of ion current connected by Faraday plate than the point-to-plate corona and/or the traditional 63Ni source. The corona configuration can also act as a good electromagnetic shielding to defense the electromagnetic emission from the corona discharge.

  8. Discharge characteristics of a penning ion source for compact neutron generator

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Weibo, E-mail: liuwb_1108@163.com [Department of Opto-Electronic Engineering, Binzhou University, Binzhou 256603 (China); Li, Mingjuan [Flying College, Binzhou University, Binzhou 256603 (China); Gao, Kun [Department of Opto-Electronic Engineering, Binzhou University, Binzhou 256603 (China); Gu, Deshan [School of Physics, Northeast Normal University, Changchun 130024 (China)

    2014-12-21

    We investigate the discharge characteristics of a penning ion source for a compact sealed neutron generator in DC mode. A measuring system consisting of console, vacuum gauges, and teslameter is established. By using the measuring system, the discharge current as a function of ion source voltage, gas pressure, and magnetic field is studied. The results show that the neutron generator can operate in a safe and steady state when the experimental parameters are as follows: ion source voltage of 1.2–2 kV, gas pressure of 4×10{sup −2}–8×10{sup −2} Pa, and magnetic field of 0.3–0.5 T. Within these ranges, the neutron yield of the generator can reach 2×10{sup 8} n/s.

  9. Carbon source from the toroidal pumped limiter during long discharge operation in Tore Supra

    International Nuclear Information System (INIS)

    Dufour, E.; Brosset, C.; Lowry, C.; Bucalossi, J.; Chappuis, P.; Corre, Y.; Desgranges, C.; Guirlet, R.; Gunn, J.; Loarer, T.; Mitteau, R.; Monier-Garbet, P.; Pegourie, B.; Reichle, R.; Thomas, P.; Tsitrone, E.; Hogan, J.; Roubin, P.; Martin, C.; Arnas, C.

    2005-01-01

    A better understanding of deuterium retention mechanisms requires the knowledge of carbon sources in Tore-Supra. The main source of carbon in the vacuum vessel during long discharges is the toroidal pumped limiter (TPL). This work is devoted to the experimental characterisation of the carbon source from the TPL surface during long discharges using a visible spectroscopy diagnostic. Moreover, we present an attempt to perform a carbon balance over a typical campaign and we discuss it with regards to the deuterium in-vessel inventory deduced from particle balance and the deuterium content of the deposited layers. The study shows that only a third of the estimated deuterium trapped in the vessel is trapped in the carbon deposits. Thus, in the present state of our knowledge and characterisation of the permanent retention, one has to search for mechanisms other than co-deposition to explain the deuterium retention in Tore Supra. (A.C.)

  10. Bifurcation and stability in Yang-Mills theory with sources

    International Nuclear Information System (INIS)

    Jackiw, R.

    1979-06-01

    A lecture is presented in which some recent work on solutions to classical Yang-Mills theory is discussed. The investigations summarized include the field equations with static, external sources. A pattern allowing a comprehensive description of the solutions and stability in dynamical systems are covered. A list of open questions and problems for further research is given. 20 references

  11. Stability analysis of direct current control in current source rectifier

    DEFF Research Database (Denmark)

    Lu, Dapeng; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    Current source rectifier with high switching frequency has a great potential for improving the power efficiency and power density in ac-dc power conversion. This paper analyzes the stability of direct current control based on the time delay effect. Small signal model including dynamic behaviors...

  12. On Stability of Voltage Source Inverters in Weak Grids

    DEFF Research Database (Denmark)

    Adib, Aswad; Mirafza, Behrooz; Wang, Xiongfei

    2018-01-01

    of circuit and control parameters on the stability of voltage source inverters are studied using a small-signal state-space model in the synchronously rotating dq-frame of reference. The full order state-space model developed in this work is directly extracted from Pulse-Width Modulation (PWM) switching......As the number of inverters increases in the power grid, the stability of grid-tied inverters becomes an important concern for the power industry. In particular, a weak grid can lead to voltage fluctuations at the inverter terminals and consequently cause inverter instability. In this paper, impacts...... pattern, and enables the stability analysis of concurrent variations in the three-phase circuit and control parameters. This paper demonstrates that the full-order model of a grid-tied PQ-controlled VSI can be significantly reduced to a second-order model, preserving the overall system stability in case...

  13. Stability and vibration control in synchrotron light source buildings

    Energy Technology Data Exchange (ETDEWEB)

    Godel, J.B.

    1991-01-01

    Synchrotron light sources have undergone three generations of development in the last two decades. The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory has two second generation'' storage rings that currently provide the world's most intense sources of photons in the VUV and X-ray spectral ranges. There are almost 90 beam lines serving a community of 2600 scientists from 370 institutions. They are engaged in basic and applied research in physics, chemistry, biology, medicine, materials science and various technologies. When design of the NSLS began in 1977, emphasis was given to the stability of the concrete slab on which the storage rings and experimental beam lines were placed. Stability is the result of controlling: vibration from sources internal and external to the building, thermal effects of air and water temperature variations, foundation settlement and contact between the slab and underlying subsoil. With the advent of new research where highly focused beams of x-rays must be placed on increasingly smaller targets located 35 meters or more from the source, and the development of x-ray lithography with resolutions approaching 0.1 micron at chip exposure stations, even greater attention to stability is required in building designs. This paper will review the results of the successful NSLS experience and give an integrated design approach that includes elements which contribute to instabilities, and the means available to reduce them to acceptable levels.

  14. Stability and vibration control in synchrotron light source buildings

    Energy Technology Data Exchange (ETDEWEB)

    Godel, J.B.

    1991-12-31

    Synchrotron light sources have undergone three generations of development in the last two decades. The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory has two ``second generation`` storage rings that currently provide the world`s most intense sources of photons in the VUV and X-ray spectral ranges. There are almost 90 beam lines serving a community of 2600 scientists from 370 institutions. They are engaged in basic and applied research in physics, chemistry, biology, medicine, materials science and various technologies. When design of the NSLS began in 1977, emphasis was given to the stability of the concrete slab on which the storage rings and experimental beam lines were placed. Stability is the result of controlling: vibration from sources internal and external to the building, thermal effects of air and water temperature variations, foundation settlement and contact between the slab and underlying subsoil. With the advent of new research where highly focused beams of x-rays must be placed on increasingly smaller targets located 35 meters or more from the source, and the development of x-ray lithography with resolutions approaching 0.1 micron at chip exposure stations, even greater attention to stability is required in building designs. This paper will review the results of the successful NSLS experience and give an integrated design approach that includes elements which contribute to instabilities, and the means available to reduce them to acceptable levels.

  15. Characteristics of cold atmospheric plasma source based on low-current pulsed discharge with coaxial electrodes

    Science.gov (United States)

    Bureyev, O. A.; Surkov, Yu S.; Spirina, A. V.

    2017-05-01

    This work investigates the characteristics of the gas discharge system used to create an atmospheric pressure plasma flow. The plasma jet design with a cylindrical graphite cathode and an anode rod located on the axis of the system allows to realize regularly reproducible spark breakdowns mode with a frequency ∼ 5 kHz and a duration ∼ 40 μs. The device generates a cold atmospheric plasma flame with 1 cm in diameter in the flow of various plasma forming gases including nitrogen and air at about 100 mA average discharge current. In the described construction the cathode spots of individual spark channels randomly move along the inner surface of the graphite electrode creating the secondary plasma stream time-average distributed throughout the whole exit aperture area after the decay of numerous filamentary discharge channels. The results of the spectral diagnostics of plasma in the discharge gap and in the stream coming out of the source are presented. Despite the low temperature of atoms and molecules in plasma stream the cathode spots operation with temperature of ∼ 4000 °C at a graphite electrode inside a discharge system enables to saturate the plasma by CN-radicals and atomic carbon in the case of using nitrogen as the working gas.

  16. Wave Driven N2-O2 Discharges as Sources of Active Species

    Science.gov (United States)

    Henriques, J.; Tatarova, E.; Ferreira, Cm.; Ricard, A.

    2003-10-01

    Microwave N2-O2 discharges driven by traveling surface waves attract attention as sources of active species, in particular for cold plasma sterilization of surgical material and other medical devices. The objective of this study is to investigate the concentration of various active species, such as O(3P) and N(4S) atoms, N2+ ions, and N2(A) and NO(A) molecules, as a function of the spatial position and the mixture composition in an azimuthally symmetric surface wave driven discharge operating at 2.45 GHz. The plasma column is created in N2-xO2 mixtures (x < 10%) at the pressure p = 5 Torr, in a quartz glass tube with inner radius a = 0.25 cm and with flow rates in the range Q = 300 -1000 sccm. Emission spectroscopy is used to measure the N2(1+,2+, 1-) and NO(γ,β) band intensities along the discharge column length. NO titration is used to determine the densities of N and O atoms in the post-discharge, close to the end of the discharge. A theoretical model is developed which accounts in a self-consistent way for the electron and heavy particle kinetics, gas thermal balance and wave electrodynamics. This model provides a satisfactory interpretation of the experimental data.

  17. Stabilization effect of fission source in coupled Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Borge; Dufek, Jan [Div. of Nuclear Reactor Technology, KTH Royal Institute of Technology, AlbaNova University Center, Stockholm (Sweden)

    2017-08-15

    A fission source can act as a stabilization element in coupled Monte Carlo simulations. We have observed this while studying numerical instabilities in nonlinear steady-state simulations performed by a Monte Carlo criticality solver that is coupled to a xenon feedback solver via fixed-point iteration. While fixed-point iteration is known to be numerically unstable for some problems, resulting in large spatial oscillations of the neutron flux distribution, we show that it is possible to stabilize it by reducing the number of Monte Carlo criticality cycles simulated within each iteration step. While global convergence is ensured, development of any possible numerical instability is prevented by not allowing the fission source to converge fully within a single iteration step, which is achieved by setting a small number of criticality cycles per iteration step. Moreover, under these conditions, the fission source may converge even faster than in criticality calculations with no feedback, as we demonstrate in our numerical test simulations.

  18. Boron ion source based on planar magnetron discharge in self-sputtering mode.

    Science.gov (United States)

    Gushenets, V I; Hershcovitch, A; Kulevoy, T V; Oks, E M; Savkin, K P; Vizir, A V; Yushkov, G Yu

    2010-02-01

    An ion source based on a planar magnetron sputtering device with thermally isolated target has been designed and demonstrated. For a boron sputtering target, high target temperature is required because boron has low electrical conductivity at room temperature, increasing with temperature. The target is well-insulated thermally and can be heated by an initial low-current, high-voltage discharge mode. A discharge power of 16 W was adequate to attain the required surface temperature (400 degrees C), followed by transition of the discharge to a high-current, low-voltage mode for which the magnetron enters a self-sputtering operational mode. Beam analysis was performed with a time-of-flight system; the maximum boron ion fraction in the beam is greater than 99%, and the mean boron ion fraction, time-integrated over the whole pulse length, is about 95%. We have plans to make the ion source steady state and test with a bending magnet. This kind of boron ion source could be competitive to conventional boron ion sources that utilize compounds such as BF(3), and could be useful for semiconductor industry application.

  19. Operating modes of a hydrogen ion source based on a hollow-cathode pulsed Penning discharge.

    Science.gov (United States)

    Oks, E M; Shandrikov, M V; Vizir, A V

    2016-02-01

    An ion source based on a hollow-cathode Penning discharge was switched to a high-current pulsed mode (tens of amperes and tens of microseconds) to produce an intense hydrogen ion beam. With molecular hydrogen (H2), the ion beam contained three species: H(+), H2(+), and H3(+). For all experimental conditions, the fraction of H2 (+) ions in the beam was about 10 ÷ 15% of the total ion beam current and varied little with ion source parameters. At the same time, the ratio of H(+) and H3(+) depended strongly on the discharge current, particularly on its distribution in the gap between the hollow and planar cathodes. Increasing the discharge current increased the H(+) fraction in ion beam. The maximum fraction of H(+) reached 80% of the total ion beam current. Forced redistribution of the discharge current in the cathode gap for increasing the hollow cathode current could greatly increase the H3(+) fraction in the beam. At optimum parameters, the fraction of H3(+) ions reached 60% of the total ion beam current.

  20. Separation of radio-frequency sources and localization of partial discharges in noisy environments.

    Science.gov (United States)

    Robles, Guillermo; Fresno, José Manuel; Martínez-Tarifa, Juan Manuel

    2015-04-27

    The detection of partial discharges (PD) can help in early-warning detection systems to protect critical assets in power systems. The radio-frequency emission of these events can be measured with antennas even when the equipment is in service which reduces dramatically the maintenance costs and favours the implementation of condition-based monitoring systems. The drawback of these type of measurements is the difficulty of having a reference signal to study the events in a classical phase-resolved partial discharge pattern (PRPD). Therefore, in open-air substations and overhead lines where interferences from radio and TV broadcasting and mobile communications are important sources of noise and other pulsed interferences from rectifiers or inverters can be present, it is difficult to identify whether there is partial discharges activity or not. This paper proposes a robust method to separate the events captured with the antennas, identify which of them are partial discharges and localize the piece of equipment that is having problems. The separation is done with power ratio (PR) maps based on the spectral characteristics of the signal and the identification of the type of event is done localizing the source with an array of four antennas. Several classical methods to calculate the time differences of arrival (TDOA) of the emission to the antennas have been tested, and the localization is done using particle swarm optimization (PSO) to minimize a distance function.

  1. Separation of Radio-Frequency Sources and Localization of Partial Discharges in Noisy Environments

    Directory of Open Access Journals (Sweden)

    Guillermo Robles

    2015-04-01

    Full Text Available The detection of partial discharges (PD can help in early-warning detection systems to protect critical assets in power systems. The radio-frequency emission of these events can be measured with antennas even when the equipment is in service which reduces dramatically the maintenance costs and favours the implementation of condition-based monitoring systems. The drawback of these type of measurements is the difficulty of having a reference signal to study the events in a classical phase-resolved partial discharge pattern (PRPD. Therefore, in open-air substations and overhead lines where interferences from radio and TV broadcasting and mobile communications are important sources of noise and other pulsed interferences from rectifiers or inverters can be present, it is difficult to identify whether there is partial discharges activity or not. This paper proposes a robust method to separate the events captured with the antennas, identify which of them are partial discharges and localize the piece of equipment that is having problems. The separation is done with power ratio (PR maps based on the spectral characteristics of the signal and the identification of the type of event is done localizing the source with an array of four antennas. Several classical methods to calculate the time differences of arrival (TDOA of the emission to the antennas have been tested, and the localization is done using particle swarm optimization (PSO to minimize a distance function.

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

    Science.gov (United States)

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

    2011-01-01

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

  3. Simulation of convection-stabilized low-current glow and arc discharges in atmospheric-pressure air

    International Nuclear Information System (INIS)

    Naidis, G V

    2007-01-01

    A two-dimensional model of stationary convection-stabilized low-current glow and arc discharge columns in atmospheric-pressure air is developed which accounts for deviation of the plasma state from the local thermodynamic equilibrium (LTE). In addition to equations of energy, continuity and momentum (analogous to those used in LTE arc models), the non-LTE model includes balance equations for plasma species and for the vibrational energy of nitrogen molecules. The kinetic scheme is used which was developed recently for the simulation of low-current wall-stabilized discharges in air. Results of calculation of discharge parameters over a wide current range are presented. It is shown that the non-equilibrium effects are substantial at currents lower than ∼ 100 mA. The calculated plasma parameters agree with available experimental data

  4. Development of high efficiency Versatile Arc Discharge Ion Source at CERN ISOLDE.

    Science.gov (United States)

    Penescu, L; Catherall, R; Lettry, J; Stora, T

    2010-02-01

    We report here recent developments of Forced Electron Beam Induced Arc Discharge (FEBIAD) ion sources at the ISOLDE radioactive ion beam facility, hosted at the European Organization for Nuclear Research (CERN). As a result of the propositions to improve the ionization efficiency, two FEBIAD prototypes have been produced and successfully tested in 2008. Off-line studies showed that the 1+ ionization efficiencies for noble gases are 5-20 times larger than with the standard ISOLDE FEBIAD ion sources and reach 60% for radon, which allowed the identification at ISOLDE of (229)Rn, an isotope that had never previously been observed in the laboratory. A factor of 3 increase is also expected for the ionization efficiency of the other elements. The experimental and theoretical methodology is presented. The theoretical model, which gives precise insights on the processes affecting the ionization, is used to design optimal sources (grouped under the name of VADIS--Versatile Arc Discharge Ion Source) for the different chemical classes of the produced isotopes, as already demonstrated for the noble gases.

  5. Compact soft x-ray microscope using a gas-discharge light source.

    Science.gov (United States)

    Benk, Markus; Bergmann, Klaus; Schäfer, David; Wilhein, Thomas

    2008-10-15

    We report on a soft x-ray microscope using a gas-discharge plasma with pseudo spark-like electrode geometry as a light source. The source produces a radiant intensity of 4 x 10(13) photons/(sr pulse) for the 2.88 nm emission line of helium-like nitrogen. At a demonstrated 1 kHz repetition rate a brilliance of 4.3 x 10(9) photons/(microm2 sr s) is obtained for the 2.88 nm line. Ray-tracing simulations show that, employing an adequate grazing incidence collector, a photon flux of 1 x 10(7) photons/(microm2 s) can be achieved with the current source. The applicability of the presented pinch plasma concept to soft x-ray microscopy is demonstrated in a proof-of-principle experiment.

  6. Thin surface layers of SiO2 obtained from tetraethoxysilane (TEOS) in electric discharges stabilized by a dielectric barrier

    International Nuclear Information System (INIS)

    Schmidt-Szalowski, K.; Fabianowski, W.; Rzanek-Boroch, Z.; Gutkowski, R.

    1998-01-01

    The reported research was devoted to the process of thin layer deposition in a discharge at atmospheric pressure stabilized by a dielectric barrier. Thin surface layers composed mainly of silicon dioxide were produced by polycondensation of tetraethoxysilane vapor in mixtures with helium gas with a small amount of oxygen. The influence was studied of the voltage applied and of the time elapsed in the deposition process, on the thickness of the layer, as were the changes of composition of the deposited layers during and after storage. It is shown that good passivating pinhole-free silicon oxide layers can be produced in surface barrier discharges. (J.U.)

  7. Determination of trace amounts of impurities in molybdenum by spark source and glow discharge mass spectrometry

    International Nuclear Information System (INIS)

    Saito, Morimasa

    1994-01-01

    For the determination of trace and ultra-trace amounts of impurities in high-purity molybdenum, spark source mass spectrometry and glow discharge mass spectrometry were studied. In spark source mass spectrometry using the metal probe method, the liquid-helium cryogenic pump was used in order to protect the surface of the samples from oxidation. The theoretical relative sensitivity factors (Mo=1) calculated from physical properties were used. The analytical results obtained for molybdenum tablet and high-purity molybdenum were in good agreement with those obtained by other methods (atomic absorption spectrometry and others). In glow discharge mass spectrometry, the relative sensitivity factors were calculated by using the results obtained by spark source mass spectrometry and atomic absorption spectrometry, and this method was applied to the determination of ultra-trace amounts of impurities in ultra high-purity molybdenum and gave the satisfactory results. The detection limits (2σ, n=10) in the integration time of 600 s for U and Th were 0.6 ppb and 0.3 ppb, and the values for Al, Si, Cr, Mn and Cu were in the range of 10 ppb to 0.5 ppb. (author)

  8. Stabilization effect of fission source in coupled Monte Carlo simulations

    Directory of Open Access Journals (Sweden)

    Börge Olsen

    2017-08-01

    Full Text Available A fission source can act as a stabilization element in coupled Monte Carlo simulations. We have observed this while studying numerical instabilities in nonlinear steady-state simulations performed by a Monte Carlo criticality solver that is coupled to a xenon feedback solver via fixed-point iteration. While fixed-point iteration is known to be numerically unstable for some problems, resulting in large spatial oscillations of the neutron flux distribution, we show that it is possible to stabilize it by reducing the number of Monte Carlo criticality cycles simulated within each iteration step. While global convergence is ensured, development of any possible numerical instability is prevented by not allowing the fission source to converge fully within a single iteration step, which is achieved by setting a small number of criticality cycles per iteration step. Moreover, under these conditions, the fission source may converge even faster than in criticality calculations with no feedback, as we demonstrate in our numerical test simulations.

  9. Ozone Production With Dielectric Barrier Discharge: Effects of Power Source and Humidity

    KAUST Repository

    Zhang, Xuming

    2016-08-24

    Ozone synthesis in air dielectric barrier discharge (DBD) was studied with an emphasis on the effects of power sources and humidity. Discharge characteristics were investigated to understand the physical properties of plasma and corresponding system performance. It was found that 10-ns pulsed DBD produced a homogeneous discharge mode, while ac DBD yielded an inhomogeneous pattern with many microdischarge channels. At a similar level of the energy density (ED), decreasing the flowrate is more effective in the production of ozone for the cases of the ac DBD, while increased voltage is more effective for the pulsed DBD. Note that the maximum ozone production efficiency (110 g/kWh) was achieved with the pulsed DBD. At the ED of ∼ 85 J/L, the ozone concentrations with dry air were over three times higher than those with the relative humidity of 100% for both the ac DBD and pulsed DBD cases. A numerical simulation was conducted using a global model to understand a detailed chemical role of water vapor to ozone production. It was found HO and OH radicals from water vapor significantly consumed O atoms, resulting in a reduction in ozone production. The global model qualitatively captured the experimental trends, providing further evidence that the primary effect of humidity on ozone production is chemical in nature.

  10. Instream Biological Assessment of NPDES Point Source Discharges at the Savannah River Site, 2000

    International Nuclear Information System (INIS)

    Specht, W.L.

    2001-01-01

    The Savannah River Site (SRS) currently has 31 NPDES outfalls that have been permitted by the South Carolina Department of Health and Environmental Control (SCDHEC) to discharge to SRS streams and the Savannah River. In order to determine the cumulative impacts of these discharges to the receiving streams, a study plan was developed to perform in-stream assessments of the fish assemblages, macroinvertebrate assemblages, and habitats of the receiving streams. These studies were designed to detect biological impacts due to point source discharges. Sampling was initially conducted between November 1997 and July 1998 and was repeated in the summer and fall of 2000. A total of 18 locations were sampled (Table 1, Figure 1). Sampling locations for fish and macroinvertebrates were generally the same. However, different locations were sampled for fish (Road A-2) and macroinvertebrates (Road C) in the lower portion of Upper Three Runs, to avoid interference with ongoing fisheries studies at Road C. Also, fish were sampled in Fourmile Branch at Road 4 rather than at Road F because the stream at Road F was too narrow and shallow to support many fish. Sampling locations and parameters are detailed in Sections 2 and 3 of this report. In general, sampling locations were selected that would permit comparisons upstream and downstream of NPDES outfalls. In instances where this approach was not feasible because effluents discharge into the headwaters of a stream, appropriate unimpacted reference were used for comparison purposes. This report summarizes the results of the sampling that was conducted in 2000 and also compares these data to the data that were collected in 1997 and 1998

  11. Investigation on discharge characteristics of a coaxial dielectric barrier discharge reactor driven by AC and ns power sources

    Science.gov (United States)

    Qian, WANG; Feng, LIU; Chuanrun, MIAO; Bing, YAN; Zhi, FANG

    2018-03-01

    A coaxial dielectric barrier discharge (DBD) reactor with double layer dielectric barriers has been developed for exhaust gas treatment and excited either by AC power or nanosecond (ns) pulse to generate atmospheric pressure plasma. The comparative study on the discharge characteristics of the discharge uniformity, power deposition, energy efficiency, and operation temperature between AC and ns pulsed coaxial DBD is carried out in terms of optical and electrical characteristics and operation temperature for optimizing the coaxial DBD reactor performance. The voltages across the air gap and dielectric layer and the conduction and displacement currents are extracted from the applied voltages and measured currents of AC and ns pulsed coaxial DBDs for the calculation of the power depositions and energy efficiencies through an equivalent electrical model. The discharge uniformity and operating temperature of the coaxial DBD reactor are monitored and analyzed by optical images and infrared camera. A heat conduction model is used to calculate the temperature of the internal quartz tube. It is found that the ns pulsed coaxial DBD has a much higher instantaneous power deposition in plasma, a lower total power consumption, and a higher energy efficiency compared with that excited by AC power and is more homogeneous and stable. The temperature of the outside wall of the AC and ns pulse excited coaxial DBD reaches 158 °C and 64.3 °C after 900 s operation, respectively. The experimental results on the comparison of the discharge characteristics of coaxial DBDs excited by different powers are significant for understanding of the mechanism of DBDs, reducing energy loss, and optimizing the performance of coaxial DBD in industrial applications.

  12. Assessment of cardiorespiratory stability using the infant car seat challenge before discharge in preterm infants (<37 weeks' gestational age).

    Science.gov (United States)

    Narvey, Michael R

    2016-04-01

    Preterm infants younger than 37 weeks corrected gestational age are at increased risk for abnormal control of respiration. The infant car seat challenge has been used as a screening tool to ensure cardiorespiratory stability before discharging preterm infants from many hospitals in Canada. While it is clear that infants placed in a car seat are more likely to experience oxygen desaturation and/or bradycardia than when they are supine, neither positioning predicts an adverse neurodevelopmental outcome or mortality post-discharge. A review of the literature yielded insufficient evidence to recommend routine use of the infant car seat challenge as part of discharge planning for preterm infants. This finding has prompted a change in recommendation from a previous Canadian Paediatric Society position statement published in 2000.

  13. Broad-beam high-current dc ion source based on a two-stage glow discharge plasma.

    Science.gov (United States)

    Vizir, A V; Oks, E M; Yushkov, G Yu

    2010-02-01

    We have designed, made, and demonstrated a broad-beam, dc, ion source based on a two-stage, hollow-cathode, and glow discharges plasma. The first-stage discharge (auxiliary discharge) produces electrons that are injected into the cathode cavity of a second-stage discharge (main discharge). The electron injection causes a decrease in the required operating pressure of the main discharge down to 0.05 mTorr and a decrease in required operating voltage down to about 50 V. The decrease in operating voltage of the main discharge leads to a decrease in the fraction of impurity ions in the ion beam extracted from the main gas discharge plasma to less than 0.2%. Another feature of the source is a single-grid accelerating system in which the ion accelerating voltage is applied between the plasma itself and the grid electrode. The source has produced steady-state Ar, O, and N ion beams of about 14 cm diameter and current of more than 2 A at an accelerating voltage of up to 2 kV.

  14. Stability of Global Alfven Waves (Tae, Eae) in Jet Tritium Discharges

    NARCIS (Netherlands)

    Kerner, W.; Borba, D.; Huysmans, G. T. A.; Porcelli, F.; Poedts, S.; Goedbloed, J. P.; Betti, R.

    1994-01-01

    The interaction of alpha-particles in JET tritium discharges with global Alfven waves via inverse Landau damping is analysed. It is found that alpha-particle driven eigenmodes were stable in the PTE1 and should also be stable in a future 50:50 deuterium-tritium mix discharge aiming at Q(DT) = 1,

  15. Quasi-Laminar Flow Characteristics in Hybrid-Stabilized Argon–Water Arc Discharge for Subsonic-Supersonic Regimes

    Czech Academy of Sciences Publication Activity Database

    Jeništa, Jiří; Takana, H.; Nishiyama, H.; Křenek, Petr; Bartlová, M.; Aubrecht, V.

    2014-01-01

    Roč. 42, č. 10 (2014), s. 2632-2633 ISSN 0093-3813 R&D Projects: GA ČR GAP205/11/2070 Institutional support: RVO:61389021 Keywords : Hybrid-stabilized electric arc * large-eddy simulation * partial characteristics * the Smagorinsky subgrid scale model Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.101, year: 2014 http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6876210

  16. Separation of sources in radiofrequency measurements of partial discharges using time-power ratio maps.

    Science.gov (United States)

    Albarracin, R; Robles, G; Martinez-Tarifa, J M; Ardila-Rey, J

    2015-09-01

    Partial discharges measurement is one of the most useful tools for condition monitoring of high-voltage (HV) equipment. These phenomena can be measured on-line in radiofrequency (RF) with sensors such as the Vivaldi antenna, used in this paper, which improves the signal-to-noise ratio by rejecting FM and low-frequency TV bands. Additionally, the power ratios (PR), a signal-processing technique based on the power distribution of the incoming signals in frequency bands, are used to characterize different sources of PD and electromagnetic noise (EMN). The calculation of the time length of the pulses is introduced to separate signals where the PR alone do not give a conclusive solution. Thus, if several EM sources could be previously calibrated, it is possible to detect pulses corresponding to PD activity. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Submarine groundwater discharge as a major source of nutrients to the Mediterranean Sea.

    Science.gov (United States)

    Rodellas, Valentí; Garcia-Orellana, Jordi; Masqué, Pere; Feldman, Mor; Weinstein, Yishai

    2015-03-31

    The Mediterranean Sea (MS) is a semienclosed basin that is considered one of the most oligotrophic seas in the world. In such an environment, inputs of allochthonous nutrients and micronutrients play an important role in sustaining primary productivity. Atmospheric deposition and riverine runoff have been traditionally considered the main external sources of nutrients to the MS, whereas the role of submarine groundwater discharge (SGD) has been largely ignored. However, given the large Mediterranean shore length relative to its surface area, SGD may be a major conveyor of dissolved compounds to the MS. Here, we used a (228)Ra mass balance to demonstrate that the total SGD contributes up to (0.3-4.8)⋅10(12) m(3) ⋅ y(-1) to the MS, which appears to be equal or larger by a factor of 16 to the riverine discharge. SGD is also a major source of dissolved inorganic nutrients to the MS, with median annual fluxes of 190⋅10(9), 0.7⋅10(9), and 110⋅10(9) mol for nitrogen, phosphorous, and silica, respectively, which are comparable to riverine and atmospheric inputs. This corroborates the profound implications that SGD may have for the biogeochemical cycles of the MS. Inputs of other dissolved compounds (e.g., iron, carbon) via SGD could also be significant and should be investigated.

  18. V-I curves and plasma parameters in a high density DC glow discharge generated by a current-source

    International Nuclear Information System (INIS)

    Granda-Gutierrez, E E; Lopez-Callejas, R; Piedad-Beneitez, A de la; BenItez-Read, J S; Pacheco-Sotelo, J O; Pena-Eguiluz, R; A, R Valencia; Mercado-Cabrera, A; Barocio, S R

    2008-01-01

    Nitrogen DC glow discharges, conducted in a cylindrical geometry, have been characterized using a new current-source able to provide 10 -3 - 3 A for the sustainment of the discharge, instead of a conventional voltage-source. The V-I characteristic curves obtained from these discharges were found to fit the general form i(v) = A(p)v k(p) , whereby the plasma itself can be modeled as a voltage-controlled current-source. We conclude that the fitting parameters A and k, which mainly depend on the gas pressure p, are strongly related to the plasma characteristics, so much so that they can indicate the pressure interval in which the maximum plasma density is located, with values in the order of 10 16 m -3 at reduced discharge potential (300-600 V) and low working pressure (10 -1 - 10 1 Pa)

  19. PROPERTIES OF ARC DISCHARGE WITH HYBRID STABILI-ZATION: IMPACT OF DIFFERENT PHYSICAL AND NUMERICAL ASSUMPTIONS

    Czech Academy of Sciences Publication Activity Database

    Jeništa, Jiří; Bartlová, M.; Aubrecht, V.

    2006-01-01

    Roč. 10, č. 4 (2006), s. 501-514 ISSN 1093-3611. [High Technology Plasma Processes (HTPP 9). St. Petersburg, 27.5.2006-4.6.2006] R&D Projects: GA ČR GA202/05/0669 Institutional research plan: CEZ:AV0Z20430508 Keywords : arc * hybrid (water) discharge * partial characteristics * upwind * grid Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.343, year: 2006

  20. Sources of particulate organic matter discharged by the Lena River using lignin phenols

    Science.gov (United States)

    Winterfeld, M.; Trojahn, S.; Hefter, J.; Pittauer, D.; Zubrzycki, S.; Han, P.; Rethemeyer, J.; Mollenhauer, G.

    2016-12-01

    Particulate organic matter (POM) discharged by rivers and deposited offshore their mouths is generally assumed to record an integrated signal from the watershed and therefore provides an archive of past environmental changes. Yet, in large river systems the riverine POM might be trapped in flood plains and the lower reaches resulting in an inefficient transport of POM particularly from the distal parts of the watershed. Further, the POM likely undergoes degradation during transport from source to sink. The Lena River is one of these large river systems stretching from 53°N to 71°N in central Siberia. The watershed can be broadly divided into two different biomes, taiga in the south and tundra in the northernmost part. The relative contribution of these biomes to the POM load of the river and its discharge to the ocean as well as the changes it is undergoing during transport are not well understood. Here we present the lignin phenol composition of different grain size fractions (bulk, 2mm-63µm, gymnosperm-derived POM, particularly close to the river mouth and in the <63µm fraction. Because of the large heterogeneity of organic matter degradation in the soil samples and their grain size fractions, it is not quite clear to which degree the POM gets mineralized within the soils and during transport in the river compared to degradation occurring during cross shelf transport.

  1. Liquid sampling-atmospheric pressure glow discharge as a secondary excitation source: Assessment of plasma characteristics

    International Nuclear Information System (INIS)

    Manard, Benjamin T.; Gonzalez, Jhanis J.; Sarkar, Arnab; Dong, Meirong; Chirinos, Jose; Mao, Xianglei; Russo, Richard E.; Marcus, R. Kenneth

    2014-01-01

    The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as a secondary excitation source with a parametric evaluation regarding carrier gas flow rate, applied current, and electrode distance. With this parametric evaluation, plasma optical emission was monitored in order to obtain a fundamental understanding with regards to rotational temperature (T rot ), excitation temperature (T exc ), electron number density (n e ), and plasma robustness. Incentive for these studies is not only for a greater overall fundamental knowledge of the APGD, but also in instrumenting a secondary excitation/ionization source following laser ablation (LA). Rotational temperatures were determined through experimentally fitting of the N 2 and OH molecular emission bands while atomic excitation temperatures were calculated using a Boltzmann distribution of He and Mg atomic lines. The rotational and excitation temperatures were determined to be ∼ 1000 K and ∼ 2700 K respectively. Electron number density was calculated to be on the order of ∼ 3 × 10 15 cm −3 utilizing Stark broadening effects of the Hα line of the Balmer series and a He I transition. In addition, those diagnostics were performed introducing magnesium (by solution feed and laser ablation) into the plasma in order to determine any perturbation under heavy matrix sampling. The so-called plasma robustness factor, derived by monitoring Mg II/Mg I emission ratios, is also employed as a reflection of potential perturbations in microplasma energetics across the various operation conditions and sample loadings. While truly a miniaturized source ( 3 volume), the LS-APGD is shown to be quite robust with plasma characteristics and temperatures being unaffected upon introduction of metal species, whether by liquid or laser ablation sample introduction. - Highlights: • Liquid sampling-atmospheric pressure glow discharge (LS-APGD) • LS-APGD as a secondary excitation source for laser-ablated (LA

  2. A Black-box Modelling Engine for Discharge Produced Plasma Radiation Sources

    International Nuclear Information System (INIS)

    Zakharov, S.V.; Choi, P.; Krukovskiy, A.Y.; Zhang, Q.; Novikov, V.G.; Zakharov, V.S.

    2006-01-01

    A Blackbox Modelling Engine (BME), is an instrument based on the adaptation of the RMHD code Z*, integrated into a specific computation environment to provide a turn key simulation instrument and to enable routine plasma modelling without specialist knowledge in numerical computation. Two different operating modes are provided: Detailed Physics mode and Fast Numerics mode. In the Detailed Physics mode, non-stationary, non-equilibrium radiation physics have been introduced to allow the modelling of transient plasmas in experimental geometry. In the Fast Numerics mode, the system architecture and the radiation transport is simplified to significantly accelerate the computation rate. The Fast Numerics mode allows the BME to be used realistically in parametric scanning to explore complex physical set up, before using the Detailed Physics mode. As an example of the results from the BME modelling, the EUV source plasma dynamics in the pulsed capillary discharge are presented

  3. Liquid sampling-atmospheric pressure glow discharge as a secondary excitation source: Assessment of plasma characteristics

    Science.gov (United States)

    Manard, Benjamin T.; Gonzalez, Jhanis J.; Sarkar, Arnab; Dong, Meirong; Chirinos, Jose; Mao, Xianglei; Russo, Richard E.; Marcus, R. Kenneth

    The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as a secondary excitation source with a parametric evaluation regarding carrier gas flow rate, applied current, and electrode distance. With this parametric evaluation, plasma optical emission was monitored in order to obtain a fundamental understanding with regards to rotational temperature (Trot), excitation temperature (Texc), electron number density (ne), and plasma robustness. Incentive for these studies is not only for a greater overall fundamental knowledge of the APGD, but also in instrumenting a secondary excitation/ionization source following laser ablation (LA). Rotational temperatures were determined through experimentally fitting of the N2 and OH molecular emission bands while atomic excitation temperatures were calculated using a Boltzmann distribution of He and Mg atomic lines. The rotational and excitation temperatures were determined to be ~ 1000 K and ~ 2700 K respectively. Electron number density was calculated to be on the order of ~ 3 × 1015 cm- 3 utilizing Stark broadening effects of the Hα line of the Balmer series and a He I transition. In addition, those diagnostics were performed introducing magnesium (by solution feed and laser ablation) into the plasma in order to determine any perturbation under heavy matrix sampling. The so-called plasma robustness factor, derived by monitoring Mg II/Mg I emission ratios, is also employed as a reflection of potential perturbations in microplasma energetics across the various operation conditions and sample loadings. While truly a miniaturized source (laser ablation sample introduction.

  4. Is groundwater discharge a significant source of carbon dioxide in North Creek, NSW, Australia?

    Science.gov (United States)

    Atkins, M. L.; Santos, I. R.; Ruiz-Halpern, S.

    2012-12-01

    Dissolved carbon dioxide is enriched in groundwater. However, the contribution of groundwater discharge as a source of CO2 to freshwater ecosystems, estuaries and coastal waters is poorly understood. CO2 evasion from waterbodies has been considered a significant contributor to the global carbon cycle. We assessed for radon (natural groundwater tracer), pCO2 and other parameters in the tidal North Creek in northern NSW, Australia. Once a natural wetland area, the floodplain has been extensively drained for agricultural and residential development. A 16km high resolution spatial survey revealed increasing radon (up to 17.3 dpm L-1) and pCO2 (up to 11151 μatm) concentration in the upstream direction. Allocated 24-h time series experiments were performed at two fixed sites downstream and upstream. Creek water was continuously pumped into a shower head equilibrator. A Licor-7000 and RAD7 monitor were connected in series in a closed air loop system incorporating the showerhead exchanger to measure pCO2 and radon at 10 minute intervals. Under normal hydrological conditions, radon (17.5 - 58.7 dpm L-1) and pCO2 (3031 - 14880 μatm) concentrations were high. Upstream measurements demonstrated a strong correlation between pCO2 and radon (r2 = 0.81, n = 142, p standard deviation and median flux for the three time series deployments were 167 mmol m-2 d-1, 44 mmol m-2 d-1 and 154 mmol m-2 d-1 respectively, rendering this aquatic system a major pathway of CO2 to the atmosphere. Our observations imply that groundwater discharge drove CO2 dynamics at the upstream site while mangrove respiration drove CO2 at the downstream site. Overall, groundwater discharge accounted for at least 32% of surface water in North Creek. Our observations demonstrate that groundwater seepage is an important factor driving CO2 supersaturation in this coastal creek. Groundwater should be accounted for in CO2 budgets in coastal waters.

  5. Identification of nitrate sources and discharge-depending nitrate dynamics in a mesoscale catchment

    Science.gov (United States)

    Mueller, Christin; Strachauer, Ulrike; Brauns, Mario; Musolff, Andreas; Kunz, Julia Vanessa; Brase, Lisa; Tarasova, Larisa; Merz, Ralf; Knöller, Kay

    2017-04-01

    During the last decades, nitrate concentrations in surface and groundwater have increased due to land use change and accompanying application of fertilizer in agriculture as well as increased atmospheric deposition. To mitigate nutrient impacts on downstream aquatic ecosystems, it is important to quantify potential nitrate sources, instream nitrate processing and its controls in a river system. The objective of this project is to characterize and quantify (regional) scale dynamics and trends in water and nitrogen fluxes of the entire Holtemme river catchment in central Germany making use of isotopic fingerprinting methods. Here we compare two key date sampling campaigns in 2014 and 2015, with spatially highly resolved measurements of discharge at 23 sampling locations including 11 major tributaries and 12 locations at the main river. Additionally, we have data from continuous runoff measurements at 10 locations operated by the local water authorities. Two waste water treatment plants contribute nitrogen to the Holtemme stream. This contribution impacts nitrate loads and nitrate isotopic signatures depending on the prevailing hydrological conditions. Nitrogen isotopic signatures in the catchment are mainly controlled by different sources (nitrified soil nitrogen in the headwater and manure/ effluents from WWTPs in the lowlands) and increase with raising nitrate concentrations along the main river. Nitrate loads at the outlet of the catchment are extremely different between both sampling campaigns (2014: NO3- = 97 t a-1, 2015: NO3- = 5 t a-1) which is associated with various runoff (2014: 0.8 m3 s-1, 2015: 0.2 m3 s-1). In 2015, the inflow from WWTP's raises the NO3- loads and enriches δ18O-NO3 values. Generally, oxygen isotope signatures from nitrate are more variable and are controlled by biogeochemical processes in concert with the oxygen isotopic composition of the ambient water. Elevated δ18O-NO3 in 2015 are most likely due to higher temperatures and lower

  6. Current profile control and magnetohydrodynamic stability in Tore Supra discharges with edge-plasma control by the ergodic divertor

    International Nuclear Information System (INIS)

    Zabiego, M.; Friant, C.; Ghendrih, P.; Becoulet, M.; Bucalossi, J.; Saint-Laurent, F.

    1999-01-01

    Although ergodic divertors are primarily designed to control particle and heat fluxes at the plasma edge, they also happen to affect the MHD stability of tokamak discharges. On Tore Supra, the ergodic divertor has long been known to stabilize the m/n=2/1 tearing mode induced, for instance, by edge radiation and detachment processes, thus allowing safe high-current and high-density operations. More recently, though, in discharges where ergodic divertor operations were optimised relative to the control of the edge-plasma (i.e., with large divertor perturbation), a detrimental increase in the disruptiveness has been observed. The action that the ergodic divertor has on the MHD activity is interpreted in terms of a redistribution of the current profile. The latter results from a large increase in the edge resistivity, primarily induced by the degradation of the electron energy confinement in the ergodic layer. The possibility that a transport barrier develops in the vicinity of the separatrix strongly affects the considered modelling. (authors)

  7. Numerical simulation of atmospheric-pressure helium discharge driven by combined radio frequency and trapezoidal pulse sources

    International Nuclear Information System (INIS)

    Wang Qi; Sun Jizhong; Zhang Jianhong; Ding Zhenfeng; Wang Dezhen

    2010-01-01

    Atmospheric-pressure capacitive discharges driven by combined radio frequency (rf) and trapezoidal pulse sources are investigated using a one-dimensional self-consistent fluid model. The results show that the plasma intensity in the rf discharge can be enhanced drastically when a low duty ratio short pulse source is additionally applied. The mechanism for the increase in the plasma density can be attributed to a strong localized electric field induced by the applied short pulse; the strong electric field generates a great number of high energy electrons and chemically active particles, which subsequently generate more electrons and ions. The rf capacitive discharges with the aid of externally applied short pulses can achieve a high plasma density with better power efficiency.

  8. Simulated impacts of artificial groundwater recharge and discharge of the source area and source volume of an Atlantic Coastal Plain Stream, Delaware, USA

    Science.gov (United States)

    Kasper, Joshua W.; Denver, Judish M.; McKenna, Thomas E.; Ullman, William J.

    2010-01-01

    A numerical groundwater-flow model was used to characterize the source area and volume of Phillips Branch, a baseflow-dominated stream incising a highly permeable unconfined aquifer on the low relief Delmarva Peninsula, USA. Particle-tracking analyses indicate that the source area (5.51 km2) is ~20% smaller than the topographically defined watershed (6.85 km2), and recharge entering ~37% of the surface watershed does not discharge to Phillips Branch. Groundwater residence time within the source volume ranges from a few days to almost 100 years, with 95% of the volume "flushing" within 50 years. Artificial discharge from groundwater pumping alters the shape of the source area and reduces baseflow due to the interception of stream flow paths, but has limited impacts on the residence time of groundwater discharged as baseflow. In contrast, artificial recharge from land-based wastewater disposal substantially reduces the source area, lowers the range in residence time due to the elimination of older flow paths to the stream, and leads to increased discharge to adjacent surface-water bodies. This research suggests that, in this and similar hydrogeologic settings, the "watershed" approach to water-resource management may be limited, particularly where anthropogenic stresses alter the transport of soluble contaminants through highly permeable unconfined aquifers.

  9. A study on prevention of an electric discharge at an extraction electrode of an electron cyclotron resonance ion source for cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kishii, Y., E-mail: Ando.Yasuto@ct.MitsubishiElectric.co.jp; Kawasaki, S. [Energy Systems Center, Mitsubishi Electric Corporation, 1-1-2 Wadasaki-cho, Hyogo-ku, Kobe 652-8555 (Japan); Kitagawa, A.; Muramatsu, M. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Uchida, T. [Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe 350-8585 (Japan); Graduate School of Interdisciplinary New Science, Toyo University, 2100 Kujirai, Kawagoe 350-8585 (Japan)

    2014-02-15

    A compact ECR ion source has utilized for carbon radiotherapy. In order to increase beam intensity with higher electric field at the extraction electrode and be better ion supply stability for long periods, electric geometry and surface conditions of an extraction electrode have been studied. Focusing attention on black deposited substances on the extraction electrode, which were observed around the extraction electrode after long-term use, the relation between black deposited substances and the electrical insulation property is investigated. The black deposited substances were inspected for the thickness of deposit, surface roughness, structural arrangement examined using Raman spectroscopy, and characteristics of electric discharge in a test bench, which was set up to simulate the ECR ion source.

  10. High current 66 kV tests on high stability PFN discharge capacitors for CERN LHC

    CERN Document Server

    Barnes, M J

    1999-01-01

    The European Laboratory for Particle Physics (CERN) is constructing a Large Hadron Collider (LHC) to be installed in an existing 27 km circumference tunnel. The LHC will be equipped with fast pulsed magnet systems for injecting two counter-rotating hadron beams. Two pulsed systems, of 4 magnets and 4 pulse forming networks (PFNs) each, are required for this purpose. TRIUMF will build and test 5 resonant charging power supplies (RCPS) and nine PFNs and the associated thyratron switch units as part of the Canadian contribution to CERN LHC. Failures in the PFN capacitors may lead to incorrect beam deflections that may in turn damage LHC components. For this reason the reliability of the capacitors must be exceptionally high. Hence sample PFN capacitors were purchased and tested. The test procedure included discharging the PFN capacitors from 66 kV, into a 10.1 Ohm resistance, for 500,000 cycles, at a frequency of approximately 1 Hz. Subsequently the PFN capacitors were discharged from 66 kV into a 2.7 Ohm resist...

  11. On spatial stabilization of dielectric barrier discharge microfilaments by residual heat build-up in air

    Science.gov (United States)

    Ráhel, Jozef; Szalay, Zsolt; Čech, Jan; Morávek, Tomás

    2016-04-01

    Microfilaments of dielectric barrier discharge are known for their multiple re-appearance at the same spot on dielectrics. This effect of localized re-appearance is driven by residual excited species and ions, surface charge deposited on the dielectric and the local temperature build-up resulting in the local increase of reduced electric field E/ΔN. To assess the magnitude of the latter, the breakdown voltage vs. temperature up to 180 °C was carefully measured at coplanar DBD and used as an input into the numerical simulation of heat build-up by the train of discharge pulses. An average reduction of breakdown voltage was found to be 20 V/K. The model predicted a quasi-stable microfilament temperature into which the thermal build-up rapidly converges. Its magnitude agreed well with the reported rotational temperature of similar electrode configuration. The impact of quasi-stable temperature on microfilament formation dynamics is further discussed. Contribution to the Topical Issue "Recent Breakthroughs in Microplasma Science and Technology", edited by Kurt Becker, Jose Lopez, David Staack, Klaus-Dieter Weltmann and Wei Dong Zhu.

  12. Xenon capillary discharge as a source of soft X-ray

    Czech Academy of Sciences Publication Activity Database

    Vrba, Pavel; Vrbová, M.

    2002-01-01

    Roč. 52, supplement D (2002), s. 112-116 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/20th./. Prague, 10.06.2002-13.06.2002] Institutional research plan: CEZ:AV0Z2043910 Keywords : capillary discharge, soft X-ray Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.311, year: 2002

  13. A new design of a test platform for testing multiple partial discharge sources

    NARCIS (Netherlands)

    Rodrigo Mor, A. R.; Castro Heredia, L.C.; Harmsen, Daniel A.; Muñoz Muñoz, F.A.

    Partial discharge (PD) measurements are an effective tool for insulation assessment of high-voltage (HV) equipment widely used in both HV laboratories and in field tests. This paper presents the design of a test platform for electrical detection of partial discharges that contribute to the

  14. FINANCIAL STABILITY OF INSURANCE AND ITS SOURCES OF SUPPORT

    Directory of Open Access Journals (Sweden)

    R. Pikus

    2016-03-01

    Full Text Available The article describes theoretical aspects of determination of financial stability of insurance companies of Ukraine. It was found the main factors that influence the financial stability of insurance companies. Influencing factors are classified into internal and external and the effects of these factors on insurers' activities are presented. The main criteria of financial stability of insurance companies were deeply analysed and the most significant were chosen: sufficient amount of equity capital, the optimal tariff policy, balanced insurance portfolio, secure and effective reinsurance program, sufficient amount of insurance reserves for future payments, optimal investment management of insurance reserves and high solvency of an insurance company. Basic directions of provision and maintenance of financial stability of insurance companies in post-crisis period were presented. The main problems of provision and maintenance of financial stability of insurance companies were outlined and recommendations for its strengthening were provided.

  15. Partial discharge tests and characterisation of the Advanced Photon Source linac modulator cables

    International Nuclear Information System (INIS)

    Cours, A.

    2007-01-01

    The advanced photon source (APS) linac modulators are PFN-type pulsers with switch-mode charging power supplies (PSs). The PS and the PFN are connected to each other by 15 feet of 100-kV x-ray cable, with the PFN end of the cable terminated with a connector that was confirmed partial-discharge (PD)-free up to 38 kV ac (53.5 kV peak). Another end of the cable is terminated with a connector that was designed by the PS manufacturer and cannot easily be replaced with another type of connector, since part of it is located inside the densely packed PS. PD tests of the cables with this type of connector show that the PD inception voltages (PDIVs) in different cables turn out to be located within a wide voltage range: 21 to 27 kV ac that corresponds to 29 to 38 kV peak. In order to evaluate the insulation condition of the modulator cables, detect insulation deterioration, and ensure failure-preventing equipment maintenance, over the last two years the PDIVs of all high-voltage (HV) cables in use in the modulators have been tested about every three and a half months. Before the tests, all cables were removed from the equipment, carefully cleaned, inspected, and regreased. The tests were performed using a 40-kV PD detector. The test results show that: 1 The PDIVs remain almost unchanged in all tested cables. 2 From test to test, the PDIV of any particular cable may slightly oscillate around some average value. This possibly depends on the connector regreasing technique. 3 There is no direct evidence of cable insulation deterioration during more than two years of operation under voltage higher than the PD inception level.

  16. Stabilization of electrohydrodynamic jets by gas discharges and applications to printing

    Science.gov (United States)

    Korkut, Sibel

    From integrated circuits to DNA hybridization micro arrays, many areas of research require flexible and reliable, high resolution surface patterning tools. A new surface patterning technique, electrohydrodynamic printing (EHDP) [1] provides high resolution and speed at the same time, which was not attainable with the existing direct surface patterning techniques. Stability of electrohydrodynamic (EHD) jets determines the accuracy of deployment in EHD printing [1-3]; therefore, understanding non-axisymmetric instability of the jet, which is caused by the surface charges, is crucial to successful operation. In this thesis, fast imaging and image analysis techniques are used to determine non-axisymmetric disturbance growth rates experimentally. Comparison of experimental instability growth rates with the theoretical estimations based on total current reveals a big discrepancy. It is also found that instability growth rates decrease and stability of EHD filaments is enhanced either by decreasing the electrode separation or by changing the surrounding gas. After considering all possible mechanisms, it is concluded that the main reason for stabilization is the increased ionization of the surrounding gas. Gas ionization results in partial neutralization of surface charges on the filament by the oppositely charged ions in the gas phase and stabilizes the jet. A new current balance including the charge transfer through the gas is developed to estimate the charge density left on the filament. Experimental and theoretical instability growth rates agree much better when the estimated charge density is used for the instability growth rate calculations. The second part of the thesis focuses on pattern formation on the surfaces. The final pattern produced with a colloidal suspension by EHDP depends on not only the stability of the jet but also the dynamics of the suspension and the stability of printed lines after the deployment. Rivulet instability, which causes deployed

  17. Submarine groundwater discharge driven nitrogen fluxes to Long Island Sound, NY: Terrestrial vs. marine sources

    Science.gov (United States)

    Tamborski, J. J.; Cochran, J. K.; Bokuniewicz, H. J.

    2017-12-01

    Bottom-waters in Smithtown Bay (Long Island Sound, NY) are subject to hypoxic conditions every summer despite limited nutrient inputs from waste-water and riverine sources, while modeling estimates of groundwater inputs are thought to be insignificant. Terrestrial and marine fluxes of submarine groundwater discharge (SGD) were quantified to Smithtown Bay using mass balances of 222Rn, 224Ra, 226Ra and 228Ra during the spring and summer of 2014/2015, in order to track this seasonal transition period. Intertidal pore waters from a coastal bluff (terrestrial SGD) and from a barrier beach (marine SGD) displayed substantial differences in N concentrations and sources, traced using a multi-isotope approach (222Rn, Ra, δ15N-NO3-, δ18O-NO3-). NO3- in terrestrial SGD did not display any seasonality and was derived from residential septic systems and fertilizer. Marine SGD N concentrations varied month-to-month because of mixing between oxic seawater and hypoxic saline pore waters; N concentrations were greatest during the summer, when NO3- was derived from the remineralization of organic matter. Short-lived 222Rn and 224Ra SGD fluxes were used to determine remineralized N loads along tidal recirculation flow paths, while long-lived 228Ra was used to trace inputs of anthropogenic N in terrestrial SGD. 228Ra-derived terrestrial N load estimates were between 20 and 55% lower than 224Ra-derived estimates (excluding spring 2014); 228Ra may be a more appropriate tracer of terrestrial SGD N loads. Terrestrial SGD NO3- (derived from 228Ra) to Smithtown Bay varied from (1.40-12.8) ∗ 106 mol N y-1, with comparable marine SGD NO3- fluxes of (1.70-6.79) ∗ 106 mol N y-1 derived from 222Rn and 224Ra. Remineralized N loads were greater during the summer compared with spring, and these may be an important driver toward the onset of seasonal hypoxic conditions in Smithtown Bay and western Long Island Sound. Seawater recirculation through the coastal aquifer can rival the N load from

  18. Stabilization of ion source operation for the ''EG-2.5'' electrostatic accelerator

    International Nuclear Information System (INIS)

    Nikitin, V.A.; Yakushev, V.P.

    1980-01-01

    A system for stabilization of operating conditions of an electrostatic accelerator ion source is described. The system is the first stage of stabilizing the ion current on a target. The current of the beam escaping from a source is equal to the difference between the currents in the source anode and cathode circuits. In the anode circuit the current is stabilized by changing the HF-generator anode voltage, and the cathode current is stabilized by a special automatic device. This ensures the constancy of the current for a beam which escapes from the source and thus increases the stability of ion currents on a target. The range of current control in the source anode circuit constitutes 15-110 μA, current oscillations do not exceed 0.5% during two hours [ru

  19. Long-Term Charge/Discharge Cycling Stability of MnO2 Aqueous Supercapacitor under Positive Polarization

    KAUST Repository

    Ataherian, Fatemeh

    2011-01-01

    The long-term charge/discharge cycling stability of MnO 2 electrode under positive polarization in aqueous KCl electrolyte has been studied over different potential windows spanning from the open circuit potential to varied higher-end potential limited by O 2 evolution. Cycling up to 1.2 V (vs Ag/AgCl (aq)) causes partial (35) capacitance fading to a plateau value within the initial cycles, accompanied by morphological reconstruction, reduction of surface Mn ions and oxygen evolution. The surface Mn-ion reduction has been attributed to a two-step oxidation-reduction mechanism involving OH oxidation in electrolyte, based on electrochemical analysis. When cycling potential extends to 1.4 V, extensive oxygen evolution takes place. The combination of surface passivation of current collector and extensive gas bubbling, which deteriorates electrical contact among the constituent particles within the electrode, results in further monotonic capacitance reduction. © 2011 The Electrochemical Society.

  20. A Bayesian geostatistical approach for evaluating the uncertainty of contaminant mass discharges from point sources

    DEFF Research Database (Denmark)

    Troldborg, Mads; Nowak, Wolfgang; Binning, Philip John

    of both concentration and groundwater flow. For risk assessments or any other decisions that are being based on mass discharge estimates, it is essential to address these uncertainties. We present a novel Bayesian geostatistical approach for quantifying the uncertainty of the mass discharge across...... and the hydraulic gradient across the control plane and are consistent with measurements of both hydraulic conductivity and head at the site. An analytical macro-dispersive transport solution is employed to simulate the mean concentration distribution across the control plane, and a geostatistical model of the Box......Estimates of mass discharge (mass/time) are increasingly being used when assessing risks of groundwater contamination and designing remedial systems at contaminated sites. Mass discharge estimates are, however, prone to rather large uncertainties as they integrate uncertain spatial distributions...

  1. Instream biological assessment of NPDES point source discharges at the Savannah River Site, 1997-1998

    Energy Technology Data Exchange (ETDEWEB)

    Specht, W.L.

    2000-02-28

    The Savannah River Site currently has 33 permitted NPDES outfalls that have been permitted by the South Carolina Department of Health an Environmental Control to discharge to SRS streams and the Savannah River. In order to determine the cumulative impacts of these discharges to the receiving streams, a study plan was developed to perform in-stream assessments of the fish assemblages, macroinvertebrate assemblages, and habitats of the receiving streams.

  2. Instream biological assessment of NPDES point source discharges at the Savannah River Site, 1997-1998

    International Nuclear Information System (INIS)

    Specht, W.L.

    2000-01-01

    The Savannah River Site currently has 33 permitted NPDES outfalls that have been permitted by the South Carolina Department of Health an Environmental Control to discharge to SRS streams and the Savannah River. In order to determine the cumulative impacts of these discharges to the receiving streams, a study plan was developed to perform in-stream assessments of the fish assemblages, macroinvertebrate assemblages, and habitats of the receiving streams

  3. Development of soft ionization using direct current pulse glow discharge plasma source in mass spectrometry for volatile organic compounds analysis

    Science.gov (United States)

    Nunome, Yoko; Kodama, Kenji; Ueki, Yasuaki; Yoshiie, Ryo; Naruse, Ichiro; Wagatsuma, Kazuaki

    2018-01-01

    This study describes an ionization source for mass analysis, consisting of glow discharge plasma driven by a pulsed direct-current voltage for soft plasma ionization, to detect toxic volatile organic compounds (VOCs) rapidly and easily. The novelty of this work is that a molecular adduct ion, in which the parent molecule attaches with an NO+ radical, [M + NO]+, can be dominantly detected as a base peak with little or no fragmentation of them in an ambient air plasma at a pressure of several kPa. Use of ambient air as the discharge plasma gas is suitable for practical applications. The higher pressure in an ambient air discharge provided a stable glow discharge plasma, contributing to the soft ionization of organic molecules. Typical mass spectra of VOCs toluene, benzene, o-xylene, chlorobenzene and n-hexane were observed as [M + NO]+ adduct ion whose peaks were detected at m/z 122, 108, 136, 142 and 116, respectively. The NO generation was also confirmed by emission bands of NO γ-system. The ionization reactions were suggested, such that NO+ radical formed in an ambient air discharge could attach with the analyte molecule.

  4. LASER EMISSIONS FROM CO2 VIBRATIONAL TRANSITIONS IN A LOW TEMPERATURE SUPERSONIC FLOW EXCITED BY A PULSED ELECTRON BEAM STABILIZED DISCHARGE

    OpenAIRE

    Fontaine, B.; Forestier, B.; Gross, P.; Koudriavtsev, E.

    1980-01-01

    High power long pulse infrared laser emission has been achieved on CO2 molecule with the high density and very low temperature supersonic flow-electron beam-stabilized discharge excitation device developped at I.M.F.M. ([MATH] [MATH] 2 amagats, T [MATH] 70 - 150 K). Laser emission at [MATH] = 10.6 µ has been achieved for a resonant cavity set at the discharge location and also 3 cm downstream of the discharge location. With Ar/CO2, Ar/CO2/H2, He/CO2, and He/CO2/N2 mixtures, lasing energy and ...

  5. Fluvial sediments a summary of source, transportation, deposition, and measurement of sediment discharge

    Science.gov (United States)

    Colby, B.R.

    1963-01-01

    This paper presents a broad but undetailed picture of fluvial sediments in streams, reservoirs, and lakes and includes a discussion of the processes involved in the movement of sediment by flowing water. Sediment is fragmental material that originates from the chemical or physical disintegration of rocks. The disintegration products may have many different shapes and may range in size from large boulders to colloidal particles. In general, they retain about the same mineral composition as the parent rocks. Rock fragments become fluvial sediment when they are entrained in a stream of water. The entrainment may occur as sheet erosion from land surfaces, particularly for the fine particles, or as channel erosion after the surface runoff has accumulated in streams. Fluvial sediments move in streams as bedload (particles moving within a few particle diameters of the streambed) or as suspended sediment in the turbulent flow. The discharge of bedload varies with several factors, which may include particle size and a type of effective shear on the surface of the streambed. The discharge of suspended sediment depends partly on concentration of moving sediment near the streambed and hence on discharge of bedload. However, the concentration of fine sediment near the streambed varies widely, even for equal flows, and, therefore, the discharge of fine sediment normally cannot be computed theoretically. The discharge of suspended sediment also depends on velocity, turbulence, depth of flow, and fall velocity of the particles. In general, the coarse sediment transported by a stream moves intermittently and is discharged at a rate that depends on properties of the flow and of the sediment. If an ample supply of coarse sediment is available at the surface of the streambed, the discharge of the coarse sediment, such as sand, can be roughly computed from properties of the available sediment and of the flow. On the other hand, much of the fine sediment in a stream usually moves nearly

  6. Stability of very-high pressure arc discharges against perturbations of the electron temperature

    Energy Technology Data Exchange (ETDEWEB)

    Benilov, M. S. [Departamento de Fisica, Ciencias Exactas e Engenharia, Universidade da Madeira, Largo do Municipio, Funchal 9000 (Portugal); Hechtfischer, U. [Philips Lighting, BU Automotive Lamps, Technology, Philipsstrasse 8, Aachen 52068 (Germany)

    2012-04-01

    We study the stability of the energy balance of the electron gas in very high-pressure plasmas against longitudinal perturbations, using a local dispersion analysis. After deriving a dispersion equation, we apply the model to a very high-pressure (100 bar) xenon plasma and find instability for electron temperatures, T{sub e}, in a window between 2400 K and 5500-7000 K x 10{sup 3} K, depending on the current density (10{sup 6}-10{sup 8} A/m{sup 2}). The instability can be traced back to the Joule heating of the electron gas being a growing function of T{sub e}, which is due to a rising dependence of the electron-atom collision frequency on T{sub e}. We then analyze the T{sub e} range occurring in very high-pressure xenon lamps and conclude that only the near-anode region exhibits T{sub e} sufficiently low for this instability to occur. Indeed, previous experiments have revealed that such lamps develop, under certain conditions, voltage oscillations accompanied by electromagnetic interference, and this instability has been pinned down to the plasma-anode interaction. A relation between the mechanisms of the considered instability and multiple anodic attachments of high-pressure arcs is discussed.

  7. Surface modification and stability of detonation nanodiamonds in microwave gas discharge plasma

    International Nuclear Information System (INIS)

    Stanishevsky, Andrei V.; Walock, Michael J.; Catledge, Shane A.

    2015-01-01

    Graphical abstract: - Highlights: • Single and binary gas plasma modification of nanodiamond powders studied. • Temperature-dependent effect of N 2 and N 2 /H 2 plasma reported for the first time. • Role of H 2 in H 2 /N 2 and H 2 /O 2 plasma modification of nanodiamond discussed. - Abstract: Detonation nanodiamonds (DND), with low hydrogen content, were exposed to microwave plasma generated in pure H 2 , N 2 , and O 2 gases and their mixtures, and investigated using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Raman, and X-ray photoelectron spectroscopies. Considerable alteration of the DND surface was observed under the plasma conditions for all used gases, but the diamond structure of the DND particle core was preserved in most cases. The stabilizing effect of H 2 in H 2 /N 2 and H 2 /O 2 binary gas plasmas on the DND structure and the temperature-dependent formation of various CNH x surface groups in N 2 and H 2 /N 2 plasmas were observed and discussed for the first time. DND surface oxidation and etching were the main effects of O 2 plasma, whereas the N 2 plasma led to DND surfaces rich in amide groups below 1073 K and nitrile groups at higher temperatures. Noticeable graphitization of the DND core structure was detected only in N 2 plasma when the substrate temperature was above 1103 K.

  8. Recent advances in incoherent light sources in the vacuum-ultraviolet (88-200nm) based on electric discharge plasmas

    International Nuclear Information System (INIS)

    Ward, B.K.; Carman, R.J.; Mildren, R.P.; Kane, D.M.

    2004-01-01

    Full text: Rare-gas and rare gas-halide excimer lamps are powerful, frequency agile, mercury-free sources of high power, narrow band (10nm-30nm), UV and VUV radiation covering the wavelength range 88nm-320nm. A very efficient and practically convenient method of excitation is achieved using the dielectric barrier discharge (DBD). In the DBD, charge build-up on an insulating (dielectric) barrier at one or both of the electrodes provides an intrinsic mechanism for quenching the discharge before the transition to a high current discharge. The UV/VUV output from rare-gas DBD lamps is highly monochromatic, derived predominantly from 2nd excimer continuum, with negligible output at visible and infrared wavelengths. For DBD lamps powered by sinusoidal voltage waveforms (50Hz-100kHz), the electrical to optical conversion efficiency typically reaches 10-20%. The discharge structure consists of multiple transient plasma aments that occur stochastically in time during the discharge cycle leading to VUV output pulses with irregular spacing and amplitude. We have shown, however, that using discrete high-voltage pulses of relatively short duration, produces a short-lived homogeneous discharge that generates much higher peak power from short (sub-microsecond) VUV output pulses, with an additional increase (two- fold) in overall efficiency. Conversion efficiencies between 40-60% have also been reported for short-pulse excitation techniques. Efficient generation of pulsed, high peak-power VUV output is of interest for a broad range of applications in time-resolved spectroscopy, photo-lithography, materials processing and surface modification/cleaning, killing of micro- organisms and bacteria, sterilization, and in ozone production for water purification

  9. Surface modification and stability of detonation nanodiamonds in microwave gas discharge plasma

    Energy Technology Data Exchange (ETDEWEB)

    Stanishevsky, Andrei V., E-mail: astan@uab.edu; Walock, Michael J.; Catledge, Shane A.

    2015-12-01

    Graphical abstract: - Highlights: • Single and binary gas plasma modification of nanodiamond powders studied. • Temperature-dependent effect of N{sub 2} and N{sub 2}/H{sub 2} plasma reported for the first time. • Role of H{sub 2} in H{sub 2}/N{sub 2} and H{sub 2}/O{sub 2} plasma modification of nanodiamond discussed. - Abstract: Detonation nanodiamonds (DND), with low hydrogen content, were exposed to microwave plasma generated in pure H{sub 2}, N{sub 2}, and O{sub 2} gases and their mixtures, and investigated using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Raman, and X-ray photoelectron spectroscopies. Considerable alteration of the DND surface was observed under the plasma conditions for all used gases, but the diamond structure of the DND particle core was preserved in most cases. The stabilizing effect of H{sub 2} in H{sub 2}/N{sub 2} and H{sub 2}/O{sub 2} binary gas plasmas on the DND structure and the temperature-dependent formation of various CNH{sub x} surface groups in N{sub 2} and H{sub 2}/N{sub 2} plasmas were observed and discussed for the first time. DND surface oxidation and etching were the main effects of O{sub 2} plasma, whereas the N{sub 2} plasma led to DND surfaces rich in amide groups below 1073 K and nitrile groups at higher temperatures. Noticeable graphitization of the DND core structure was detected only in N{sub 2} plasma when the substrate temperature was above 1103 K.

  10. Dither-free stabilization of CH3OH pumping sources

    Science.gov (United States)

    Bennett, C. A.; Patterson, J. D.; Hutchinson, D. P.

    1986-08-01

    A dither-free stabilization scheme was reported recently1 in which the optical transmission through an absorption cell filled with CH2F2 provided an error signal necessary to stabilize the 214-μm line of CH2F2. Measurements have indicated that this technique is difficult to apply to the 119-μm line of CH3OH due to a lack of contrast in the absorption features of CH3OH over the tuning range of the pump. Efforts to find a nonlasant gas with the required absorption features and to develop a similar technique based on the photoacoustic technique will be described. This research was supported by the Office of Fusion Energy, U.S. DOE, under Contract No. DE-AC05-84OR21400 with Martin Marietta Energy Systems, Inc.

  11. Fluid model of dc glow discharge with nonlocal ionization source term

    International Nuclear Information System (INIS)

    Rafatov, I R; Bogdanov, E A; Kudryavtsev, A A

    2012-01-01

    We developed and tested a simple hybrid model for a glow discharge, which incorporates nonlocal ionization by fast electrons into the fluid framework. Calculations have been performed for an argon gas. Comparison with the experimental data as well as with the hybrid (particle) and fluid modelling results demonstated good applicability of the proposed model.

  12. A High Reliability Frequency Stabilized Semiconductor Laser Source, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Ultrastable, narrow linewidth, high reliability MOPA sources are needed for high performance LIDARs in NASA for, wind speed measurement, surface topography and earth...

  13. Survey, alignment, and beam stability at the Advanced Light Source

    International Nuclear Information System (INIS)

    Krebs, G.F.

    1997-10-01

    This paper describes survey and alignment at the Lawrence Berkeley Laboratories Advanced Light Source (ALS) accelerators from 1993 to 1997. The ALS is a third generation light source requiring magnet alignment to within 150 microns. To accomplish this, a network of monuments was established and maintained. Monthly elevation surveys show the movement of the floor over time. Inclinometers have recently been employed to give real time information about magnet, vacuum tank and magnet girder motion in the ALS storage ring

  14. Dielectric barrier discharges: progress on plasma sources and on the understanding of regimes and single filaments

    Science.gov (United States)

    Brandenburg, Ronny

    2017-05-01

    Dielectric barrier discharges (DBDs) are plasmas generated in configurations with an insulating (dielectric) material between the electrodes which is responsible for a self-pulsing operation. DBDs are a typical example of nonthermal atmospheric or normal pressure gas discharges. Initially used for the generation of ozone, they have opened up many other fields of application. Therefore DBDs are a relevant tool in current plasma technology as well as an object for fundamental studies. Another motivation for further research is the fact that so-called partial discharges in insulated high voltage systems are special types of DBDs. The breakdown processes, the formation of structures, and the role of surface processes are currently under investigation. This review is intended to give an update to the already existing literature on DBDs considering the research and development within the last two decades. The main principles and different modes of discharge generation are summarized. A collection of known as well as special electrode configurations and reactor designs will be presented. This shall demonstrate the different and broad possibilities, but also the similarities and common aspects of devices for different fields of applications explored within the last years. The main part is devoted to the progress on the investigation of different aspects of breakdown and plasma formation with the focus on single filaments or microdischarges. This includes a summary of the current knowledge on the electrical characterization of filamentary DBDs. In particular, the recent new insights on the elementary volume and surface memory mechanisms in these discharges will be discussed. An outlook for the forthcoming challenges on research and development will be given.

  15. [Spatial discharge characteristics and total load control of non-point source pollutants based on the catchment scale].

    Science.gov (United States)

    Wang, Xia-Hui; Lu, Jun; Zhang, Qing-Zhong; Wang, Bo; Yao, Rui-Hua; Zhang, Hui-Yuan; Huang, Feng

    2011-09-01

    Agricultural non-point source pollution is one of the major causes of water quality deterioration. Based on the analysis of the spatial discharge characteristics and intensity of major pollutants from the agricultural pollution source, the establishment of spatial management subzones for controlling agricultural non-point pollution and a design of a plan for total load control of pollutants from each subzone is an important way to improve the efficiency of control measures. In this paper the Four Lake basin in Hubei Province is adopted as the research case region and a systematic research of the control countermeasures of agricultural non-point pollution based on the catchment scale is carried out. The results shows that in the Four Lake basin, the COD, total nitrogen, total phosphorus and ammonia nitrogen load of the water environment are mainly caused by agricultural non-point pollution. These four kinds of non-point source pollutants respectively account for 67.6%, 82.2%, 84.7% and 50.9% of the total pollutant discharge amount in the basin. The analysis of the spatial discharge characteristics of non-point source pollutants in the Four Lake basin shows that the major contributor source regions of non-point source pollutant in the basin are the four counties, including Honghu, Jianli, Qianjiang and Shayang where the aquatic and livestock production are relatively developed. According to the spatial discharge characteristics of the pollutants and the evaluation of the discharge intensity of pollutants, the Four Lake basin is divided into three agricultural non-point pollution management subzones, which including Changhu upstream aquatic and livestock production pollution control subzone, Four-lake trunk canal rural non-point source pollution control subzone and Honghu aquatic production pollution control subzone. Specific pollution control measures are put forward for each subzone. With a comprehensive consideration of the water quality amelioration and the

  16. Impact of pulsed-electric field and high-voltage electrical discharges on red wine microbial stabilization and quality characteristics.

    Science.gov (United States)

    Delsart, C; Grimi, N; Boussetta, N; Miot Sertier, C; Ghidossi, R; Vorobiev, E; Mietton Peuchot, M

    2016-01-01

    In this study, pulsed-electric fields (PEF) and high-voltage electrical discharges (HVED) are proposed as new techniques for the microbial stabilization of red wines before bottling. The efficiency of the treatment was then evaluated. PEF and HVED-treatments have been applied to wine for the inactivation of Oenococcus oeni CRBO 9304, O. oeni CRBO 0608, Pediococcus parvulus CRBO 2.6 and Brettanomyces bruxellensis CB28. Different treatment times (1, 2, 4, 6, 8 and 10 ms) were used at 20 kV cm(-1) for the PEF treatments and at 40 kV for the HVED treatments, which correspond to applied energies from 80 to 800 kJ l(-1) . The effects of the treatments on the microbial inactivation rate and on various characteristics of red wines (phenolic composition, chromatic characteristics and physico-chemical parameters) were measured. The application of PEF or HVED treatments on red wine allowed the inactivation of alteration yeasts (B. bruxellensis CB28) and bacteria (O. oeni CRBO 9304, O. oeni CRBO 0608 and P. parvulus CRBO 2.6). The electric discharges at 40 kV were less effective than the PEF even after 10 ms of treatments. Indeed, 4 ms of PEF treatment at 20 kV cm(-1) were sufficient to inactivate all micro-organisms present in the wines. Also, the use of PEF had no negative impact on the composition of wines compared to the HVED treatments. Contrary to PEF, the phenolics compounds were degraded after the HVED treatment and the physico-chemical composition of wine were modified with HVED. PEF technology seems to be an interesting alternative to stabilize microbiologically wines before bottling and without modifying their composition. This process offers many advantages for winemakers: no chemical inputs, low energy consumption (320 kJ l(-1) ), fast (treatment time of 4 ms) and athermal (ΔT ≈ 10°C). © 2015 The Society for Applied Microbiology.

  17. Space-Qualifiable High Reliability Frequency-Stabilized CW Laser Source Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the SBIR Phase II effort to develop and space-qualify a 1.06 micron high reliability frequency-stabilized CW laser source that fully satisfies the...

  18. Space-Qualifiable High Reliability Frequency-Stabilized CW Laser Source Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the development and space qualification of a high reliability frequency-stabilized CW laser source at 1064 nm wavelength region to satisfy the...

  19. Microplasma source based on a dielectric barrier discharge for the determination of mercury by atomic emission spectrometry.

    Science.gov (United States)

    Zhu, Zhenli; Chan, George C-Y; Ray, Steven J; Zhang, Xinrong; Hieftje, Gary M

    2008-11-15

    A low-power, atmospheric-pressure microplasma source based on a dielectric barrier discharge (DBD) has been developed for use in atomic emission spectrometry. The small plasma (0.6 mm x 1 mm x 10 mm) is generated within a glass cell by using electrodes that do not contact the plasma. Powered by an inexpensive ozone generator, the discharge ignites spontaneously, can be easily sustained in Ar or He at gas flow rates ranging from 5 to 200 mL min(-1), and requires less than 1 W of power. The effect of operating parameters such as plasma gas identity, plasma gas flow rate, and residual water vapor on the DBD source performance has been investigated. The plasma can be operated without removal of residual water vapor, permitting it to be directly coupled with cold vapor generation sample introduction. The spectral background of the source is quite clean in the range from 200 to 260 nm with low continuum and structured components. The DBD source has been applied to the determination of Hg by continuous-flow, cold vapor generation and offers detection limits from 14 (He-DBD) to 43 pg mL(-1) (Ar-DBD) without removal of the residual moisture. The use of flow injection with the He-DBD permits measurement of Hg with a 7.2 pg limit of detection, and with repetitive injections having an RSD of <2% for a 10 ng mL(-1) standard.

  20. Research on numerical method for multiple pollution source discharge and optimal reduction program

    Science.gov (United States)

    Li, Mingchang; Dai, Mingxin; Zhou, Bin; Zou, Bin

    2018-03-01

    In this paper, the optimal method for reduction program is proposed by the nonlinear optimal algorithms named that genetic algorithm. The four main rivers in Jiangsu province, China are selected for reducing the environmental pollution in nearshore district. Dissolved inorganic nitrogen (DIN) is studied as the only pollutant. The environmental status and standard in the nearshore district is used to reduce the discharge of multiple river pollutant. The research results of reduction program are the basis of marine environmental management.

  1. High-performance cathode elements for gas-discharge light sources

    Directory of Open Access Journals (Sweden)

    Sevastyanov V. V.

    2009-02-01

    Full Text Available Application of cathode elements of the arc-discharge activator made on the basis of developed material — alloy of iridium and rare-earth metals (of cerium group — has been suggested. The working samples of arc lamps have been produced and tested. The location of metal-alloy cathode has been optimized. The tests demonstrated, that after 4500 hours of work the lighting-up and glowing parameters of such lamps remained stable.

  2. Wastewater discharge impact on drinking water sources along the Yangtze River (China).

    Science.gov (United States)

    Wang, Zhuomin; Shao, Dongguo; Westerhoff, Paul

    2017-12-01

    Unplanned indirect (de facto) wastewater reuse occurs when wastewater is discharged into surface waters upstream of potable drinking water treatment plant intakes. This paper aims to predict percentages and trends of de facto reuse throughout the Yangtze River watershed in order to understand the relative contribution of wastewater discharges into the river and its tributaries towards averting water scarcity concerns. The Yangtze River is the third longest in the world and supports more than 1/15 of the world's population, yet the importance of wastewater on the river remains ill-defined. Municipal wastewater produced in the Yangtze River Basin increased by 41% between 1998 and 2014, from 2580m 3 /s to 3646m 3 /s. Under low flow conditions in the Yangtze River near Shanghai, treated wastewater contributions to river flows increased from 8% in 1998 to 14% in 2014. The highest levels of de facto reuse appeared along a major tributary (Han River) of the Yangtze River, where de facto reuse can exceed 20%. While this initial analysis of de facto reuse used water supply and wastewater data from 110 cities in the basin and 11 gauging stations with >50years of historic streamflow data, the outcome was limited by the lack of gauging stations at more locations (i.e., data had to be predicted using digital elevation mapping) and lack of precise geospatial location of drinking water intakes or wastewater discharges. This limited the predictive capability of the model relative to larger datasets available in other countries (e.g., USA). This assessment is the first analysis of de facto wastewater reuse in the Yangtze River Basin. It will help identify sections of the river at higher risk for wastewater-related pollutants due to presence of-and reliance on-wastewater discharge that could be the focus of field studies and model predictions of higher spatial and temporal resolution. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The source of X-rays and high-charged ions based on moderate power vacuum discharge with laser triggering

    Directory of Open Access Journals (Sweden)

    Alkhimova Mariya A.

    2015-06-01

    Full Text Available The source of X-ray radiation with the energy of quanta that may vary in the range hν = 1÷12 keV was developed for studies in X-ray interaction with matter and modification of solid surfaces. It was based on a vacuum spark discharge with the laser triggering. It was shown in our experiments that there is a possibility to adjust X-ray radiation spectrum by changing the configuration of the electrode system when the energy stored in the capacitor is varied within the range of 1÷17 J. A comprehensive study of X-ray imaging and quanta energy was carried out. These experiments were carried out for the case of both direct and reverse polarity of the voltage on the electrodes. Additionally, ion composition of plasma created in a laser-triggered vacuum discharge was analyzed. Highly charged ions Zn(+21, Cu(+20 and Fe(+18 were observed.

  4. Submarine groundwater discharge as an important nutrient source influencing nutrient structure in coastal water of Daya Bay, China

    Science.gov (United States)

    Wang, Xuejing; Li, Hailong; Zheng, Chunmiao; Yang, Jinzhong; Zhang, Yan; Zhang, Meng; Qi, Zhanhui; Xiao, Kai; Zhang, Xiaolang

    2018-03-01

    As an important nutrient source for coastal waters, submarine groundwater discharge (SGD) has long been largely ignored in Daya Bay, China. In this study, we estimate the fluxes of SGD and associated nutrients into this region using a 224Ra mass balance model and assess the contribution/importance of nutrients by SGD, benthic sediments, local rivers, and atmospheric deposition. The results of 224Ra mass balance show that the estimated SGD ranges from (2.76 ± 1.43) × 106 m3/d to (1.03 ± 0.53) × 107 m3/d with an average of (6.32 ± 2.42) × 106 m3/d, about 16 times the total discharge rate of local rivers. The nutrient loading from SGD is estimated to be (1.05-1.99) × 105 mol/d for NO3-N, (4.04-12.16) × 103 mol/d for DIP, and (3.54-11.35) × 105 mol/d for Si. Among these considered nutrient sources, we find that SGD is the primary source for Si and NO3-N, contributing 68% and 42% of all considered sources, respectively. The atmospheric NO3-N flux is comparable to that from SGD. The local rivers are the most important source for DIP, contributing 75% of all considered sources. SGD with high N:P ratio (NO3-N/DIP) of 37.0 delivers not only a large quantity of nutrients, but also changes nutrient structure in coastal water. Based on a DIP budget, primary productivity is evaluated to be 54-73 mg C/m2 d, in which SGD accounts for approximately 30% of total production. This study indicates that SGD is a key source of nutrients to coastal waters and may cause an obvious change of primary production and nutrient structure in Daya Bay.

  5. Emission characteristics and stability of laser ion sources

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; Velyhan, Andriy; Krouský, Eduard; Láska, Leoš; Rohlena, Karel; Jungwirth, Karel; Ullschmied, Jiří; Lorusso, A.; Velardi, L.; Nassisi, V.; Czarnecka, A.; Ryc, L.; Parys, P.; Wolowski, J.

    2010-01-01

    Roč. 85, č. 5 (2010), s. 617-621 ISSN 0042-207X R&D Projects: GA AV ČR IAA100100715 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : laser ion sources * ion emission reproducibility * thermal and fast ions * ion temperature * centre-of-mass velocity Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.048, year: 2010

  6. Miniature High Stability High Temperature Space Rated Blackbody Radiance Source

    Science.gov (United States)

    Jones, J. A.; Beswick, A. G.

    1987-09-01

    This paper presents the design and test performance of a conical cavity type blackbody radiance source that will meet the requirements of the Halogen Occultation Experiment (HALOE) on the NASA Upper Atmospheric Research Satellite program (UARS). Since a radiance source meeting the requirements of this experiment was unavailable in the commercial market, a development effort was undertaken by the HALOE Project. The blackbody radiance source operates in vacuum at 1300 K + 0.5 K over any 15-minute interval, uses less than 7.5 watts of power, maintains a 49°C outer case temperature, and fits within the 2.5 x 2.5 x 3.0 inch envelope allocated inside the HALOE instrument. Also, the unit operates in air, during ground testing of the HALOE instrument, where it uses 17 watts of power with an outer case temperature of 66°C. The thrust of this design effort was to minimize the heat losses, in order to keep the power usage under 7.5 watts, and to minimize the amount of silica in the materials. Silica in the presence of the platinum heater winding used in this design would cause the platinum to erode, changing the operating temperature set-point. The design required the development of fabrication techniques which would provide very small, close tolerance parts from extremely difficult-to-machine materials. Also, a space rated ceramic core and unique, low thermal conductance, ceramic-to-metal joint was developed, tested and incorporated in this design. The completed flight qualification hardware has undergone performance, environmental and life testing. The design configuration and test results are discussed in detail in this paper.

  7. Sputtering in a glow discharge ion source - pressure dependence: theory and experiment

    International Nuclear Information System (INIS)

    Mason, R.S.; Pichilingi, Melanie

    1994-01-01

    A simplified theoretical expression has been developed for a glow discharge to show how the average cathode erosion rate (expressed as the number of atoms per ion of the total bombarding flux) varies with primary sputter yield, pressure, 'diffusion length' and sputtered atom 'stopping' cross section. An inverse pressure dependence is predicted which correlates well with experiment in the 2 and He, tend to converge. It is suggested that this could be due to a change in the mechanism to self-sputtering. Under constant conditions, the erosion rates of different cathode materials still correlate quite well with the differences in their primary sputter yields. (author)

  8. Dynamics of suspended sediment concentration, flow discharge and sediment particle size interdependency to identify sediment source

    Science.gov (United States)

    Sadeghi, Seyed Hamidreza; Singh, Vijay P.

    2017-11-01

    Spatiotemporal behavior of sediment yield is a key for proper watershed management. This study analyzed statistical characteristics and trends of suspended sediment concentration (SCS), flow discharge (FD) and sediment particle sizes using data from 24 gage stations scattered throughout the United States. Analysis showed significant time- and location-specific differences of these variables. The median values of SSC, FD and percentage of particle sizes smaller than 63 μm (P63) for all 24 gage stations were found to be 510.236 mg l-1 (right skewed), 45.406 m3 s-1 (left skewed) and 78.648% (right skewed), respectively. Most of the stations exhibited significant trends (P type and erosivity, watershed area, and soil erodibility) and human-affected (i.e., land use and hydraulic structures and water resources management) factors governing the study variables.

  9. Ambient desorption/ionization mass spectrometry using a liquid sampling-atmospheric glow discharge (LS-APGD) ionization source.

    Science.gov (United States)

    Marcus, R Kenneth; Burdette, Carolyn Q; Manard, Benjamin T; Zhang, Lynn X

    2013-10-01

    A novel approach to ambient desorption/ionization mass spectrometry (ADI-MS) is described, based on a recently developed liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source. The device is essentially unmodified relative to its implementation in elemental mass spectrometry, where the operational space is characterized by low operation power (LS-APGD source is mounted onto the source interface of a Thermo Finnigan LCQ Advantage Max quadrupole ion trap mass spectrometer without modifications to the instrument faceplate or ion optics. Described here is the initial evaluation of the roles of source geometry and working parameters, including electrolytic solution composition and plasma current, on the response of caffeine residues, with preliminary limits of detection based on the relative standard deviation of the spectral background suggested to be on the 10-pg level. Demonstrative spectra are presented for green tea extracts and raw leaves, coffee beans, a dried (raw) tobacco leaf, an analgesic tablet, and paper currency. Versatility is further revealed through the determination of components in common cigarette smoke. In each case, the spectra are characterized by (M + H)(+) species of the expected constituents. The capacity for a single source to perform both in solution and particulate elemental analysis (as shown previously) and ADI of molecular species is unique in the realm of mass spectrometry.

  10. Effect of the relative phase of the driving sources on heating of dual frequency capacitive discharges

    Science.gov (United States)

    Ziegler, Dennis; Trieschmann, Jan; Mussenbrock, Thomas; Brinkmann, Ralf Peter

    2009-10-01

    The influence of the relative phase of the driving voltages on heating in asymmetric dual frequency capacitive discharges is investigated. Basis of the analysis is a recently published global model [1] extended by the possibility to freely adjust the phase angles between the driving voltages. In recent publications it was reported that nonlinear electron resonance heating (NERH) drastically enhances dissipation at moments of sheath collapse due to plasma series resonance (PSR) excitation [2]. This work shows that depending on the relative phase of the driving voltages, the total number and exact moments of sheath collapse can be influenced. In case of a collapse directly being followed by a second collapse ("double collapse") a substantial increase in dissipated power, well above the reported growth due to a single PSR excitation event per period, can be observed.[4pt] [1] D.,iegler, T.,ussenbrock, and R.,. Brinkmann, Phys. Plasmas 16, 023503 (2009)[0pt] [2] T.,ussenbrock, R.,. Brinkmann, M.,. Lieberman, A.,. Lichtenberg, and E. Kawamura, Phys. Rev. Lett. 101, 085004 (2008)

  11. An Impedance-Based Stability Analysis Method for Paralleled Voltage Source Converters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2014-01-01

    This paper analyses the stability of paralleled voltage source converters in AC distributed power systems. An impedance-based stability analysis method is presented based on the Nyquist criterion for multiloop system. Instead of deriving the impedance ratio as usual, the system stability...... of converter and the passive network can also be predicted by the Nyquist diagrams. This method is applied to evaluate the current and voltage controller interactions of converters in both grid-connected and islanded operations. Simulations and experimental results verify the effectiveness of theoretical...... analysis....

  12. High stabilized power sources for bending and quadrupole magnets of TRISTAN project

    International Nuclear Information System (INIS)

    Kumagai, Noritaka; Ogawa, Shin-ichi; Koseki, Shoichiro; Nagasaka, Saburo.

    1984-01-01

    In the power source exciting the electro-magnets for the electron ring of TRISTAN project being advanced in the National Laboratory for High Energy Physics, the performance as strict as 10 -4 is required for its long hour stability and pulsating rate of DC output current in order to maintain beam stably. For satisfying such specification, the structure of power source using a high accuracy current detector, an active filter and so on was adopted. In order to verify the performance of this power source, the trial manufacture was carried out independently, and the test combining with actual magnets was performed. As the results, it was confirmed that the power source had the sufficient performance about its output stability, pulsating rate, current-following property and so on. At present, the manufacture of 80 actual power sources is in progress. In this paper, the power source system and the results of performance test of the power source made for trial are reported. The power sources are divide into B power sources for exciting deflecting electro-magnets and Q power sources for exciting quadrupole electro-magnets. (Kako, I.)

  13. Degradation of bisphenol-A by dielectric barrier discharge system: influence of polyethylene glycol stabilized nano zero valent iron particles

    Science.gov (United States)

    Tijani, Jimoh O.; Mouele, Massima E. S.; Fatoba, Ojo O.; Babajide, Omotola O.; Petrik, Leslie F.

    2017-09-01

    In this study we report the synthesis and catalytic properties of polyethylene glycol stabilized nano zero valent iron particles (PEG-nZVI) added to the dielectric barrier discharge (DBD) system to induce photo-Fenton process in the degradation of bisphenol A (BPA) in aqueous solution. The influence of operating parameters such as solution pH, initial concentration of the modelled pollutant and PEG-nZVI dosage on the extent of BPA degradation was investigated. The residual concentration of BPA and its intermediates were determined using high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LCMS). The high resolution scanning electron microscope (HRSEM), x-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, and x-ray photoelectron spectroscopy (XPS) analysis confirmed the formation of filamentous, high surface area iron nanoparticles in the zero valent state. The BPA mineralization rate was monitored using total organic carbon (TOC) analyser. 100% BPA removal was achieved with DBD/PEG-nZVI system within 30 min compared to 67.9% (BPA) with DBD alone after 80 min. The complete BPA removal within a short reaction time was attributed to the existence of a synergetic effect in the combined DBD/PEG-nZVI system. Five new transformation products of BPA namely: 4-nitrophenol (C6H5NO3), 4-nitrosophenolate (C6H4NO2), 4-(prop-1-en-2-yl) cyclohexa-3,5-diene-1,2-dione, (C9H8O2), 4-(2-hydroxylpropan-2-yl)cyclohexane-3,5-diene-1,2-dione (C9H10O3), and 1,2-dimethyl-4-(2-nitropropan-2-yl)benzene (C9H10NO4) were identified. BPA degradation proceeded via ozonation, hydroxylation, dimerization, and decarboxylation and nitration step. The combined DBD/photo-Fenton-induced process was found to be the most efficient in the elimination of BPA in aqueous solutions and DBD alone.

  14. Repetitively pulsed UV radiation source based on a run-away electron preionised diffuse discharge in nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Baksht, E Kh; Burachenko, A G; Lomaev, M I; Panchenko, A N; Tarasenko, V F [Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation)

    2015-04-30

    An extended repetitively pulsed source of spontaneous UV radiation is fabricated, which may also be used for producing laser radiation. Voltage pulses with an incident wave amplitude of up to 30 kV, a half-amplitude duration of ∼4 ns and a rise time of ∼2.5 ns are applied to a gap with a nonuniform electric field. For an excitation region length of 35 cm and a nitrogen pressure of 30 – 760 Torr, a diffusive discharge up to a pulse repetition rate of 2 kHz is produced without using an additional system for gap preionisation. An investigation is made of the plasma of the run-away electron preionised diffuse discharge. Using a CCD camera it is found that the dense diffused plasma fills the gap in a time shorter than 1 ns. X-ray radiation is recorded from behind the foil anode throughout the pressure range under study; a supershort avalanche electron beam is recorded by the collector electrode at pressures below 100 Torr. (laser applications and other topics in quantum electronics)

  15. Repetitively pulsed UV radiation source based on a run-away electron preionised diffuse discharge in nitrogen

    Science.gov (United States)

    Baksht, E. Kh; Burachenko, A. G.; Lomaev, M. I.; Panchenko, A. N.; Tarasenko, V. F.

    2015-04-01

    An extended repetitively pulsed source of spontaneous UV radiation is fabricated, which may also be used for producing laser radiation. Voltage pulses with an incident wave amplitude of up to 30 kV, a half-amplitude duration of ~4 ns and a rise time of ~2.5 ns are applied to a gap with a nonuniform electric field. For an excitation region length of 35 cm and a nitrogen pressure of 30 - 760 Torr, a diffusive discharge up to a pulse repetition rate of 2 kHz is produced without using an additional system for gap preionisation. An investigation is made of the plasma of the run-away electron preionised diffuse discharge. Using a CCD camera it is found that the dense diffused plasma fills the gap in a time shorter than 1 ns. X-ray radiation is recorded from behind the foil anode throughout the pressure range under study; a supershort avalanche electron beam is recorded by the collector electrode at pressures below 100 Torr.

  16. Heat sources for glacial ice melt in a West Greenland tidewater outlet glacier fjord: The role of subglacial freshwater discharge

    DEFF Research Database (Denmark)

    Bendtsen, Jørgen; Mortensen, John; Lennert, Kunuk

    2015-01-01

    The melting of tidewater outlet glaciers from the Greenland Ice Sheet contributes significantly to global sea level rise. Accelerated mass loss is related to melt-processes in front of calving glaciers, yet the role of ocean heat transports is poorly understood. Here we present the first direct...... measurements from a subglacial plume in front of a calving tidewater outlet glacier. Surface salinity in the plume corresponded to a meltwater content of 7 %, which is indicative of significant entrainment of warm bottom water and, according to plume model calculations, significant ice melt. Energy balance...... of the area near the glacier showed that ice melt was mainly due to ocean heat transport and that direct plume-associated melt was only important in periods with high meltwater discharge rates of ~100 m3 s−1. Ocean mixing outside of the plume area was thus the primary heat source for melting glacier ice....

  17. Factory-discharged pharmaceuticals could be a relevant source of aquatic environment contamination: review of evidence and need for knowledge.

    Science.gov (United States)

    Cardoso, Olivier; Porcher, Jean-Marc; Sanchez, Wilfried

    2014-11-01

    Human and veterinary active pharmaceutical ingredients (APIs) are involved in contamination of surface water, ground water, effluents, sediments and biota. Effluents of waste water treatment plants and hospitals are considered as major sources of such contamination. However, recent evidences reveal high concentrations of a large number of APIs in effluents from pharmaceutical factories and in receiving aquatic ecosystems. Moreover, laboratory exposures to these effluents and field experiments reveal various physiological disturbances in exposed aquatic organisms. Also, it seems to be relevant to increase knowledge on this route of contamination but also to develop specific approaches for further environmental monitoring campaigns. The present study summarizes available data related to the impact of pharmaceutical factory discharges on aquatic ecosystem contaminations and presents associated challenges for scientists and environmental managers. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Novel design of high voltage pulse source for efficient dielectric barrier discharge generation by using silicon diodes for alternating current

    Science.gov (United States)

    Truong, Hoa Thi; Hayashi, Misaki; Uesugi, Yoshihiko; Tanaka, Yasunori; Ishijima, Tatsuo

    2017-06-01

    This work focuses on design, construction, and optimization of configuration of a novel high voltage pulse power source for large-scale dielectric barrier discharge (DBD) generation. The pulses were generated by using the high-speed switching characteristic of an inexpensive device called silicon diodes for alternating current and the self-terminated characteristic of DBD. The operation started to be powered by a primary DC low voltage power supply flexibly equipped with a commercial DC power supply, or a battery, or DC output of an independent photovoltaic system without transformer employment. This flexible connection to different types of primary power supply could provide a promising solution for the application of DBD, especially in the area without power grid connection. The simple modular structure, non-control requirement, transformer elimination, and a minimum number of levels in voltage conversion could lead to a reduction in size, weight, simple maintenance, low cost of installation, and high scalability of a DBD generator. The performance of this pulse source has been validated by a load of resistor. A good agreement between theoretically estimated and experimentally measured responses has been achieved. The pulse source has also been successfully applied for an efficient DBD plasma generation.

  19. External control of the synchronization dynamics of two inductively coupled glow discharge plasma sources

    Science.gov (United States)

    Chaubey, Neeraj; Mukherjee, S.; Sen, A.

    2017-10-01

    An experimental investigation of the influence of an external periodic forcing on the synchronization dynamics of two inductively coupled plasma sources is reported. The driven response of the coupled system is found to have a rich structure in the parameter space of the frequency and the amplitude of the external driver. In particular, there is a strong impact on the nature of the phase-flip transitions between anti-phase and in-phase synchronized states of the system and the frequency bifurcation structure of the collective states. The external driver provides a convenient tool for accessing various collective states of the system and controlling the collective dynamics of the two coupled systems through a proper choice of its frequency and amplitude. Our experimental results are qualitatively supported by numerical simulation results from a theoretical model of two environmentally coupled van der Pol equations, one of which is also driven externally.

  20. SPECIFICATIONS OF THE SOURCES OF SECURING INSURANCE COMPANY’S FINANCIAL STABILITY

    Directory of Open Access Journals (Sweden)

    Mariia Balytska

    2017-11-01

    Full Text Available The purpose is to generalize the methodological concepts of domestic researchers in sources of insurance companies' financial stability provision. The need in developing and deepening both theory and practice upon the issues of improving financial stability of the Ukrainian insurance companies facilitated the following tasks: analysis of methodical approaches of native researchers concerning division of financial stability sources; highlighting the most important sources of securing financial stability for insurance companies; feasibility of the role and essence of each factor securing financial stability for insurance companies. Methodology. The study is based on the theoretical analysis of scientific works and practical activity of enterprises. Methodological basis of the article are methods of scientific cognition, which enable to expose basic conformities to the law of development of the insurance companies, priority ways to ensure their financial sustainability. Such methods are in particular used: analysis and synthesis – during research of financial stability of the insurance companies; systematizations – for revealing factors of maintenance of financial stability of insurers, their detailed analysis and definition of their interrelation; scientific abstraction – with the purpose of forming theoretical generalizations and conclusions. Results. The insurance sector plays an important role in the provision of critical financial services. But insurers are exposed to a number of risks and can become distressed or fail. The article examines the essence and importance of insurance company’s financial stability as an important factor in the development and functioning of the insurance market. The economic essence of the general theoretical issues about the financial stability of insurance companies is reviewed and analysed. The main features of insurance companies and the factors that affect their financial stability are investigated

  1. Stability analysis and design of the improved droop controller on a voltage source inverter

    DEFF Research Database (Denmark)

    Calabria, Mauro; Schumacher, Walter; Guerrero, Josep M.

    2015-01-01

    This paper studies the dynamics of a droop-controlled voltage source inverter connected to a stiff grid and addresses the use of the improved droop controller in order to enhance the dynamic behavior of the system. The small-signal stability of the inverter is studied in depth considering...

  2. Determination of discharge parameters via OES at the Linac4 H{sup −} ion source

    Energy Technology Data Exchange (ETDEWEB)

    Briefi, S., E-mail: stefan.briefi@physik.uni-augsburg.de [AG Experimentelle Plasmaphysik, Institut für Physik, Universität Augsburg, 86135 Augsburg (Germany); Fink, D.; Mattei, S.; Lettry, J. [Linac4 Ion Source Team, CERN-ABP, 1211 Geneva 23 (Switzerland); Fantz, U. [AG Experimentelle Plasmaphysik, Institut für Physik, Universität Augsburg, 86135 Augsburg (Germany); Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching (Germany)

    2016-02-15

    Optical emission spectroscopy (OES) measurements of the atomic Balmer series and the molecular Fulcher transition have been carried out at the Linac4 ion source in order to determine plasma parameters. As the spectroscopic system was only relatively calibrated, the data evaluation only yielded rough estimates of the plasma parameters (T{sub e} ≈ 1.2 eV, n{sub e} ≈ 1 × 10{sup 19} m{sup −3}, and n{sub H}/n{sub H{sub 2}} ≈ 0.5 at standard operational parameters). The analysis of the Fulcher transition revealed a non-thermal “hockey-stick” rotational population of the hydrogen molecules. At varying RF power, the measurements at the on-axis line of sight (LOS) showed a peak in the rotational temperatures between 25 and 40 kW of RF power, whereas a steady decrease with power was observed at a tilted LOS, indicating the presence of strong plasma parameter gradients.

  3. Assessment of the impact that individual voltage source has on a generator’s stability

    DEFF Research Database (Denmark)

    Dmitrova, Evgeniya; Jóhannsson, Hjörtur; Nielsen, Arne Hejde

    2012-01-01

    This paper presents an approach for splitting equivalent Thevenin voltage into components induced by each voltage source in the reduced grid. Thevenin equivalent representation of the system is sometimes used for stability assessment of a given generator, where the Thevenin voltage is one...... of the key variables affecting the stability conditions. Thevenin voltage is formed by components induced by each voltage source in the grid, while depending on topology and system parameters, the impact of these components on the equivalent Thevenin voltage Eth might vary considerably. This paper...... demonstrates how the impact of individual voltage source to the Eth might be defined utilizing system admittance matrix. Knowledge about alternation of Eth while applying changes to either admittance matrix or generators’ excitation and torque gives promising perspective for determination of effective...

  4. Comparison of dielectric barrier discharge, atmospheric pressure radiofrequency-driven glow discharge and direct analysis in real time sources for ambient mass spectrometry of acetaminophen

    Czech Academy of Sciences Publication Activity Database

    Kratzer, Jan; Mester, Z.; Sturgeon, R. E.

    2011-01-01

    Roč. 66, č. 8 (2011), s. 594-603 ISSN 0584-8547 Grant - others:Akademie věd České republiky(CZ) M200310971 Institutional research plan: CEZ:AV0Z40310501 Keywords : ambient mass spectrometry * direct analysis in real time * dielectric barrier discharge Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.876, year: 2011

  5. Short- and longtime stability of therapeutic ultrasound reference sources for dosimetry and exposimetry purposes

    Science.gov (United States)

    Haller, J.; Wilkens, V.

    2017-03-01

    The objective of this work was to create highly stable therapeutic ultrasound fields with well-known exposimetry and dosimetry parameters that are reproducible and hence predictable with well-known uncertainties. Such well- known and reproducible fields would allow validation and secondary calibrations of different measuring capabilities, which is already a widely accepted strategy for diagnostic fields. For this purpose, a reference setup was established that comprises two therapeutic ultrasound sources (one High-Intensity Therapeutic Ultrasound (HITU) source and one physiotherapy-like source), standard rf electronics for signal creation, and computer-controlled feedback to stabilize the input voltage. The short- and longtime stability of the acoustic output were evaluated - for the former, measurements over typical laboratory measurement time periods (i.e. some seconds or minutes) of the input voltage stability with and without feedback control were performed. For the latter, measurements of typical acoustical exposimetry parameters were performed bimonthly over one year. The measurement results show that the short- and the longtime stability of the reference setup are very good and that it is especially significantly improved in comparison to a setup without any feedback control.

  6. Nitrogen Source Stabilization of Quorum Sensing in the Pseudomonas aeruginosa Bioaugmentation Strain SD-1.

    Science.gov (United States)

    Wang, Mei-Zhen; Lai, Bai-Min; Dandekar, Ajai A; Yang, Yu-Sheng; Li, Na; Yin, Jun; Shen, Dong-Sheng

    2017-08-15

    Pseudomonas aeruginosa SD-1 is efficient at degrading aromatic compounds and can therefore contribute to the bioremediation of wastewater. P. aeruginosa uses quorum sensing (QS) to regulate the production of numerous secreted "public goods." In wastewater bioaugmentation applications, there are myriad nitrogen sources, and we queried whether various nitrogen sources impact the stabilities of both QS and the bacterial populations. In a laboratory strain of P. aeruginosa , PAO1, the absence of a nitrogen source has been shown to destabilize these populations through the emergence of QS mutant "cheaters." We tested the ability of SD-1 to grow in casein broth, a condition that requires QS for growth, when the nitrogen source with either NH 4 Cl, NaNO 3 , or NaNO 2 or with no added nitrogen source. There was great variability in susceptibility to invasion by QS mutant cheaters and, by extension, the stability of the SD-1 population. When grown with NH 4 Cl as an extra nitrogen source, no population collapse was observed; by contrast, two-thirds of cultures grown in the presence of NaNO 2 collapsed. In the populations that collapsed, the frequency of social cheaters exceeded 40%. NaNO 3 and NaNO 2 directly favor QS mutants of P. aeruginosa SD-1. Although the mechanism by which these nitrogen sources act is not clear, these data indicate that the metabolism of nitrogen can affect the stability of bacterial populations, an important observation for continuing industrial applications with this species. IMPORTANCE Bioaugmentation as a method to help remediate wastewater pollutant streams holds significant potential to enhance traditional methods of treatment. Addition of microbes that can catabolize organic pollutants can be an effective method to remove several toxic compounds. Such bioaugmented strains of bacteria have been shown to be susceptible to competition from the microbiota that are present in wastewater streams, limiting their potential effectiveness. Here, we

  7. Catchment tracers reveal discharge, recharge and sources of groundwater-borne pollutants in a novel lake modelling approach

    Science.gov (United States)

    Kristensen, Emil; Madsen-Østerbye, Mikkel; Massicotte, Philippe; Pedersen, Ole; Markager, Stiig; Kragh, Theis

    2018-02-01

    Groundwater-borne contaminants such as nutrients, dissolved organic carbon (DOC), coloured dissolved organic matter (CDOM) and pesticides can have an impact the biological quality of lakes. The sources of pollutants can, however, be difficult to identify due to high heterogeneity in groundwater flow patterns. This study presents a novel approach for fast hydrological surveys of small groundwater-fed lakes using multiple groundwater-borne tracers. Water samples were collected from the lake and temporary groundwater wells, installed every 50 m within a distance of 5-45 m to the shore, were analysed for tracer concentrations of CDOM, DOC, total dissolved nitrogen (TDN, groundwater only), total nitrogen (TN, lake only), total dissolved phosphorus (TDP, groundwater only), total phosphorus (TP, lake only), δ18O / δ16O isotope ratios and fluorescent dissolved organic matter (FDOM) components derived from parallel factor analysis (PARAFAC). The isolation of groundwater recharge areas was based on δ18O measurements and areas with a high groundwater recharge rate were identified using a microbially influenced FDOM component. Groundwater discharge sites and the fractions of water delivered from the individual sites were isolated with the Community Assembly via Trait Selection model (CATS). The CATS model utilized tracer measurements of TDP, TDN, DOC and CDOM from the groundwater samples and related these to the tracer measurements of TN, TP, DOC and CDOM in the lake. A direct comparison between the lake and the inflowing groundwater was possible as degradation rates of the tracers in the lake were taken into account and related to a range of water retention times (WRTs) of the lake (0.25-3.5 years in 0.25-year increments). These estimations showed that WRTs above 2 years required a higher tracer concentration of inflowing water than found in any of the groundwater wells around the lake. From the estimations of inflowing tracer concentration, the CATS model isolated

  8. High-power microwave generation from a frequency-stabilized virtual cathode source

    International Nuclear Information System (INIS)

    Fazio, M.V.; Hoeberling, R.F.; Kinross-Wright, J.

    1988-01-01

    The evolution of virtual cathode based high-power microwave-source technology has been directed primarily toward achieving higher peak-power levels. As peak powers in excess of 10 GW have been reported, attention has begun to focus on techniques for producing a more frequency- and phase-stable virtual cathode source. Free-running virtual cathode microwave sources characteristically exhibit bandwidths in a single pulse of tens of percent, which makes them unsuitable for many applications such as power sources for phased array antennas and microwave linear accelerators. Presented here are results of an experimental approach utilizing a high-Q, resonant cavity surrounding the oscillating virtual cathode to achieve frequency stabilization and repeatable narrow-band operation. A cylindrical cavity resonator is used with the microwave power being extracted radially through circumferential slot apertures into L-band waveguide

  9. Effect of Inverter Power Source Characteristics on Welding Stability and Heat Affected Zone Dimensions

    Science.gov (United States)

    Il’yaschenko, D. P.; Chinakhov, D. A.; Mamadaliev, R. A.

    2018-01-01

    The paper presents results the research in the effect of power sources dynamic characteristics on stability of melting and electrode metal transfer to the weld pool shielded metal arc welding. It is proved that when applying inverter-type welding power sources, heat and mass transfer characteristics change, arc gap short-circuit time and drop generation time are reduced. This leads to reduction of weld pool heat content and contraction of the heat-affected zone by 36% in comparison the same parameters obtained using a diode rectifier.

  10. Extended stability range of weak grids with Voltage Source Converters through impedance-conditioned grid synchronization

    OpenAIRE

    Suul, Jon Are; D'Arco, Salvatore; Rodríguez Cortés, Pedro; Molinas Cabrera, Marta

    2015-01-01

    The stability range of power transfer in high impedance, weak, grids with Voltage Source Converters (VSC) can be extended a simple modification of the conventional Synchronous Reference Frame Phase Locked Loop (PLL) used for grid synchronization. By introducing an impedance-conditioning term in the voltage used by the PLL, the VSC control system is virtually synchronized to the voltage at a stronger point in the grid. By synchronization to the voltage behind the corresponding virtual impedanc...

  11. Run-away electron preionized diffuse discharge as a source of efficient laser emission in the IR, UV, VUV

    Science.gov (United States)

    Panchenko, A. N.; Panchenko, N. A.; Tarasenko, V. F.

    2017-05-01

    REP DD was suggested as an excitation source of various gas lasers. The efficient lasing was obtained in the IR, UV, and VUV spectral ranges. The ultimate intrinsic efficiency of non-chain chemical lasers on HF(DF) molecules was achieved. REP DD pumped N2 laser with an ultimate electrical efficiency of 0.2% was developed. Lasing on N2 molecules with 2 or 3 peaks in successive REP DD current oscillations was obtained for the first time. The laser action on F2* at 157 nm and rare gas fluorides (KrF*, XeF*) under REP DD pumping was obtained for the first time, as well. It has been shown that the volume stage of REP DD in mixtures with fluorine can last over 50 ns during several current half-cycles. Therewith, the efficiency and the pulse duration of lasers on rare gas fluorides and VUV F2* laser parameters under REP DD excitation are comparable with those obtained in suitable transverse discharges. The results allow the conclusion that the REP DD homogeneity in mixtures with F2 and SF6 is high enough for attaining high laser efficiency.

  12. Assessment of the discharge regime and water budget of Belo Vrelo (source of the Tolišnica River, central Serbia

    Directory of Open Access Journals (Sweden)

    Čokorilo-Ilić Marina

    2014-01-01

    Full Text Available A sufficiently long spring discharge regime monitoring data set allows for a large number of analyses, to better understand the process of transformation of precipitation into a discharge hydrograph. It is also possible to determine dynamic groundwater volumes in a karst spring catchment area, the water budget equation parameters and the like. It should be noted that a sufficiently long data set is deemed to be a continuous spring discharge time series of more than 30 years. Such time series are rare in Serbia. They are generally much shorter (less than 15 years, and the respective catchment areas therefore fall into the “ungauged” category. In order to extend existing karst spring discharge time series, we developed a model whose outputs, apart from mean monthly spring discharges, include daily real evapotranspiration rates, catchment size and dynamic volume variation during the analytical period. So far the model has solely been used to assess the discharge regime and water budget of karst springs. The present paper aims to demonstrate that the model also yields good results in the case of springs that drain aquifers developed in marbles. Belo Vrelo (“White Spring”, source of the Tolišnica River, which drains marbles and marbleized limestones and dolomites of Čemerno Mountain, was selected for the present case study. [OI-176022

  13. Stabilization of microgrid with intermittent renewable energy sources by SMES with optimal coil size

    International Nuclear Information System (INIS)

    Saejia, M.; Ngamroo, I.

    2011-01-01

    A controller design of a superconducting magnetic energy storage unit is proposed. The structure of a power controller is the practical proportional-integral (PI). The PI parameters and coil size are tuned by a particle swarm optimization. The proposed method is able to effectively alleviate power fluctuations. It is well known that the superconducting coil is the vital part of a superconducting magnetic energy storage (SMES) unit. This paper deals with the power controller design of a SMES unit with an optimal coil size for stabilization of an isolated microgrid. The study microgrid consists of renewable energy sources with intermittent power outputs i.e., wind and photovoltaic. Since power generations from such renewable sources are unpredictable and variable, these result in power fluctuations in a microgrid. To stabilize power fluctuations, a SMES unit with a fast control of active and reactive power can be applied. The structure of a power controller is the practical proportional-integral (PI). Based on the minimization of the variance of power fluctuations from renewable sources as well as the initial stored energy of SMES, the optimal PI parameters and coil size are automatically and simultaneously tuned by a particle swarm optimization. Simulation studies show that the proposed SMES controller with an optimal coil size is able to effectively alleviate power fluctuations under various power patterns from intermittent renewable sources.

  14. Liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source for elemental mass spectrometry: preliminary parametric evaluation and figures of merit.

    Science.gov (United States)

    Quarles, C Derrick; Carado, Anthony J; Barinaga, Charles J; Koppenaal, David W; Marcus, R Kenneth

    2012-01-01

    A new, low-power ionization source for the elemental analysis of aqueous solutions has recently been described. The liquid sampling-atmospheric pressure glow discharge (LS-APGD) source operates at relatively low currents (LS-APGD has been interfaced to what is otherwise an organic, LC-MS mass analyzer, the Thermo Scientific Exactive Orbitrap without any modifications, other than removing the electrospray ionization source supplied with that instrument. A glow discharge is initiated between the surface of the test solution exiting a glass capillary and a metallic counter electrode mounted at a 90° angle and separated by a distance of ~5 mm. As with any plasma-based ionization source, there are key discharge operation and ion sampling parameters that affect the intensity and composition of the derived mass spectra, including signal-to-background ratios. We describe here a preliminary parametric evaluation of the roles of discharge current, solution flow rate, argon sheath gas flow rate, and ion sampling distance as they apply on this mass analyzer system. A cursive evaluation of potential matrix effects due to the presence of easily ionized elements indicate that sodium concentrations of up to 50 μg mL(-1) generally cause suppressions of less than 50%, dependant upon the analyte species. Based on the results of this series of studies, preliminary limits of detection (LOD) have been established through the generation of calibration functions. While solution-based concentration LOD levels of 0.02-2 μg mL(-1) are not impressive on the surface, the fact that they are determined via discrete 5 μL injections leads to mass-based detection limits at picogram to single-nanogram levels. The overhead costs associated with source operation (10 W d.c. power, solution flow rates of LS-APGD ion source may present a practical alternative to inductively coupled plasma sources typically employed in elemental mass spectrometry.

  15. Multi-Source Generation Mechanisms for Low Frequency Noise Induced by Flood Discharge and Energy Dissipation from a High Dam with a Ski-Jump Type Spillway.

    Science.gov (United States)

    Lian, Jijian; Wang, Xiaoqun; Zhang, Wenjiao; Ma, Bin; Liu, Dongming

    2017-11-30

    As excess water is discharged from a high dam, low frequency noise (air pulsation lower than 10 Hz, LFN) is generated and propagated in the surrounding areas, causing environmental hazards such as the vibration of windows and doors and the discomfort of local residents. To study the generation mechanisms and key influencing factors of LFN induced by flood discharge and energy dissipation from a high dam with a ski-jump type spillway, detailed prototype observations and analyses of LFN are carried out. The discharge flow field is simulated and analyzed using a gas-liquid turbulent flow model. The acoustic response characteristics of the air cavity, which is formed between the discharge nappe and dam body, are analyzed using an acoustic numerical model. The multi-sources generation mechanisms are first proposed basing on the prototype observation results, vortex sound model, turbulent flow model and acoustic numerical model. Two kinds of sources of LFN are studied. One comes from the energy dissipation of submerged jets in the plunge pool, the other comes from nappe-cavity coupled vibration. The results of the analyses reveal that the submerged jets in the plunge pool only contribute to an on-site LFN energy of 0-1.0 Hz, and the strong shear layers around the high-velocity submerged jets and wall jet development areas are the main acoustic source regions of LFN in the plunge pool. In addition, the nappe-cavity coupled vibration, which is induced when the discharge nappe vibrates with close frequency to the model frequency of the cavity, can induce on-site LFN energy with wider frequency spectrum energy within 0-4.0 Hz. By contrast, the contribution degrees to LFN energy from two acoustic sources are almost same, while the contribution degree from nappe-cavity coupled vibration is slightly higher.

  16. Dynamic Stability Analysis of Autonomous Medium-Voltage Mixed-Source Microgrid

    DEFF Research Database (Denmark)

    Zhao, Zhuoli; Yang, Ping; Guerrero, Josep M.

    2015-01-01

    In an autonomous microgrid without connection to the interconnected grid to support the frequency and voltage, it is more complex to control and manage. Thus in order to investigate the dynamic stability of the medium-voltage (MV) microgrid in Dongao Island, a detailed small-signal state......-space model of the autonomous MV mixed-source microgrid containing diesel generator set (DGS), grid-supporting battery energy storage system (BESS), squirrel cage induction generator (SCIG) wind turbine and network is developed. Sensitivity analysis is carried out to reveal the dynamic stability margin...... of the MV microgrid and identify the permissible variations range of the droop coefficients. Finally, the theoretical analysis is verified with time-domain simulation and experimental results....

  17. Composite resin color stability: influence of light sources and immersion media

    Directory of Open Access Journals (Sweden)

    Patricia Aleixo dos Santos Domingos

    2011-06-01

    Full Text Available OBJECTIVE: This study evaluated the influence of light sources and immersion media on the color stability of a nanofilled composite resin. MATERIAL AND METHODS: Conventional halogen, high-power-density halogen and high-power-density light-emitting diode (LED units were used. There were 4 immersion media: coffee, tea, Coke® and artificial saliva. A total of 180 specimens (10 mm x 2 mm were prepared, immersed in artificial saliva for 24 h at 37±1ºC, and had their initial color measured with a spectrophotometer according to the CIELab system. Then, the specimens were immersed in the 4 media during 60 days. Data from the color change and luminosity were collected and subjected to statistical analysis by the Kruskall-Wallis test (p<0.05. For immersion time, the data were subjected to two-way ANOVA test and Fisher's test (p<0.05. RESULTS: High-power-density LED (ΔE=1.91 promoted similar color stability of the composite resin to that of the tested halogen curing units (Jet Lite 4000 plus - ΔE=2.05; XL 3000 - ΔE=2.28. Coffee (ΔE=8.40; ΔL=-5.21 showed the highest influence on color stability of the studied composite resin. CONCLUSION: There was no significant difference in color stability regardless of the light sources, and coffee was the immersion medium that promoted the highest color changes on the tested composite resin.

  18. Formation of stable direct current microhollow cathode discharge by venturi gas flow system for remote plasma source in atmosphere

    International Nuclear Information System (INIS)

    Park, Ki Wan; Lee, Tae Il; Hwang, Hyeon Seok; Noh, Joo Hyon; Baik, Hong Koo; Song, Kie Moon

    2008-01-01

    We introduce a microhollow cathode configuration with venturi gas flow to ambient air in order to obtain glow discharge at atmospheric pressure. Stable microhollow cathode discharge was formed in a 200 μm diameter at 9 mA and the optimum value of gas velocityxdiameter for hollow cathode effect was obtained in our system. In order to confirm hollow cathode effect, we measured the enhancement of E/N strength for 200 μm (0.31 m 2 /s) and 500 μm (0.78 m 2 /s) air discharge at 8 mA under the velocity of 156 m/s. As a result, an increase of 46.7% in E/N strength of the discharge of 200 μm hole was obtained compare to that of 500 μm

  19. Discharge estimation for the Upper Brahmaputra River in the Tibetan Plateau using multi-source remote sensing data

    Science.gov (United States)

    Huang, Q.; Long, D.; Du, M.; Hong, Y.

    2017-12-01

    River discharge is among the most important hydrological variables of hydrologists' concern, as it links drinking water supply, irrigation, and flood forecast together. Despite its importance, there are extremely limited gauging stations across most of alpine regions such as the Tibetan Plateau (TP) known as Asia's water towers. Use of remote sensing combined with partial in situ discharge measurements is a promising way of retrieving river discharge over ungauged or poorly gauged basins. Successful discharge estimation depends largely on accurate water width (area) and water level, but it is challenging to obtain these variables for alpine regions from a single satellite platform due to narrow river channels, complex terrain, and limited observations. Here, we used high-spatial-resolution images from Landsat series to derive water area, and satellite altimetry (Jason 2) to derive water level for the Upper Brahmaputra River (UBR) in the TP with narrow river width (less than 400 m in most occasions). We performed waveform retracking using a 50% Threshold and Ice-1 Combined algorithm (TIC) developed in this study to obtain accurate water level measurements. The discharge was estimated well using a range of derived formulas including the power function between water level and discharge, and that between water area and discharge suitable for the triangular cross-section around the Nuxia gauging station in the UBR. Results showed that the power function using Jason 2-derived water levels after performing waveform retracking performed best, showing an overall NSE value of 0.92. The proposed approach for remotely sensed river discharge is effective in the UBR and possibly other alpine rivers globally.

  20. Development of a stable source of atomic oxygen with a pulsed high-voltage discharge and its application to crossed-beam reactions.

    Science.gov (United States)

    Lu, I-Chung; Huang, Wen-Jian; Chaudhuri, Chanchal; Chen, Wei-Kan; Lee, Shih-Huang

    2007-08-01

    To investigate the reactions of oxygen atoms with ethene and silane in a crossed-beam condition, we developed a stable, highly intense, and short-pulsed source of atomic oxygen with a transient high-voltage discharge. Mixtures of O(2) and He served as discharge media. Utilizing a crossed molecular-beam apparatus and direct vacuum-ultraviolet ionization, we measured the temporal profiles of oxygen atoms and the time-of-flight spectra of reaction products. With O(2) 3% seeded in He as a discharge medium, oxygen atoms might have a full width as small as 13.5 micros at half maximum at a location 193 mm downstream from the discharge region. Most population of oxygen atoms is in the ground state (3)P but some in the first excited state (1)D, depending on the concentration of precursor O(2). This discharge device analogously generates carbon, nitrogen, and fluorine atoms from precursors CO, N(2), and F(2), respectively.

  1. Development and demonstration of a water-window soft x-ray microscope using a Z-pinching capillary discharge source

    Science.gov (United States)

    Nawaz, M. F.; Jancarek, Alexandr; Nevrkla, Michal; Duda, Martin Jakub; Pina, Ladislav

    2017-05-01

    The development and demonstration of a soft X-ray (SXR) microscope, based on a Z-pinching capillary discharge source has been realized. The Z-pinching plasma acts as a source of SXR radiation. A ceramic capacitor bank is pulsed charged up to 80 kV, and discharged through a pre- ionized nitrogen filled ceramic capillary. The discharge current has an amplitude of 25 kA. Working within the water-window spectral region (λ = 2.88 nm), corresponding to the 1s2-1s2p quantum transition of helium-like nitrogen (N5+), the microscope has a potential in exploiting the natural contrast existing between the K-absorption edges of carbon and oxygen as the main constituents of biological materials, and hence imaging them with high spatial resolution. The SXR microscope uses the grazing incidence ellipsoidal condenser mirror for the illumination, and the Fresnel zone plate optics for the imaging of samples onto a BI-CCD camera. The half- pitch spatial resolution of 100 nm [1] was achieved, as demonstrated by the knife-edge test. In order to enhance the photon-flux at the sample plane, a new scheme for focusing the radiation, from multiple capillary sources has been investigated. Details about the source, and the construction of the microscope are presented and discussed.

  2. MHD stability of (2,1) tearing mode: an issue for the preforming phase of Tore Supra non-inductive discharges

    International Nuclear Information System (INIS)

    Maget, P.; Luetjens, H.; Huysmans, G.; Moreau, Ph.; Schunke, B.; Segui, J.-L.; Garbet, X.; Joffrin, E.; Luciani, J.F.

    2007-01-01

    The early phase of a tokamak plasma discharge can have a dramatic impact on the main heating phase. This has been a persistent problem for the development of the steady state, fully non-inductive scenario using lower hybrid current drive (LHCD) on Tore Supra. The present paper reports on recent experimental and numerical investigations showing that a tearing mode coupled to the internal kink grows on q = 2 in the ohmic phase when the total current is too low, due to the weakening of field line curvature stabilization. Then, the application of LHCD drives the island to a larger size and undermines the development of the non-inductive phase. Decreasing the edge safety factor or increasing the Lundquist number S is found to be beneficial in both the linear and non-linear MHD analyses. The experimental database, which allows covering the edge safety factor dependence, supports this interpretation

  3. Discharge performance of solid-state oxygen shuttle metal-air battery using Ca-stabilized ZrO2 electrolyte.

    Science.gov (United States)

    Inoishi, Atsushi; Kim, Hack-Ho; Sakai, Takaaki; Ju, Young-Wan; Ida, Shintaro; Ishihara, Tatsumi

    2015-04-13

    The effects of metal choice on the electrochemical performance of oxygen-shuttle metal-air batteries with Ca-stabilized ZrO2 (CSZ) as the electrolyte and various metals as the anodes were studied at 1073 K. The equilibrium oxygen partial pressure (P O 2) in the anode chamber was governed by the metal used in the anode chamber. A lower-P O 2 environment in the anode decreased the polarization resistance of the anode. The oxidation of oxide ions to oxygen in the anode is drastically enhanced by the n-type conduction generated in the CSZ electrolyte when it is exposed to a reducing atmosphere. A high discharge potential and high capacity can be achieved in an oxygen-shuttle battery with a Li or Mg anode because of the fast anode reaction compared to that of cells with a Zn, Fe, or Sn anode. However, only the mildly reducing metals (Zn, Si, Fe, and Sn) can potentially be used in rechargeable metal-air batteries because the transport number of the CSZ electrolyte must be unity during charge and discharge. Oxygen shuttle rechargeable batteries with Fe, and Sn electrodes are demonstrated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. 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; ...

  5. Astaxanthin: Sources, Extraction, Stability, Biological Activities and Its Commercial Applications—A Review

    Directory of Open Access Journals (Sweden)

    Ranga Rao Ambati

    2014-01-01

    Full Text Available There is currently much interest in biological active compounds derived from natural resources, especially compounds that can efficiently act on molecular targets, which are involved in various diseases. Astaxanthin (3,3′-dihydroxy-β, β′-carotene-4,4′-dione is a xanthophyll carotenoid, contained in Haematococcus pluvialis, Chlorella zofingiensis, Chlorococcum, and Phaffia rhodozyma. It accumulates up to 3.8% on the dry weight basis in H. pluvialis. Our recent published data on astaxanthin extraction, analysis, stability studies, and its biological activities results were added to this review paper. Based on our results and current literature, astaxanthin showed potential biological activity in in vitro and in vivo models. These studies emphasize the influence of astaxanthin and its beneficial effects on the metabolism in animals and humans. Bioavailability of astaxanthin in animals was enhanced after feeding Haematococcus biomass as a source of astaxanthin. Astaxanthin, used as a nutritional supplement, antioxidant and anticancer agent, prevents diabetes, cardiovascular diseases, and neurodegenerative disorders, and also stimulates immunization. Astaxanthin products are used for commercial applications in the dosage forms as tablets, capsules, syrups, oils, soft gels, creams, biomass and granulated powders. Astaxanthin patent applications are available in food, feed and nutraceutical applications. The current review provides up-to-date information on astaxanthin sources, extraction, analysis, stability, biological activities, health benefits and special attention paid to its commercial applications.

  6. Estimating Mass Discharge From Dense Nonaqueous Phase Liquid Source Zones Using Upscaled Mass Transfer Coefficients: An Evaluation Using Multiphase Numerical Simulations

    Science.gov (United States)

    2006-11-28

    parameters including groundwater velocity, mean hydraulic conductivity, and the extent of mass removal using best fit correlation parameters. These upscaled ...Estimating mass discharge from dense nonaqueous phase liquid source zones using upscaled mass transfer coefficients: An evaluation using multiphase...of a number of simplified models that rely upon upscaled (i.e., domain-averaged) mass transfer coefficients to approximate field-scale dissolution

  7. Fast capillary discharge facility CAPEX-U as a source of the soft X-ray radiation

    Czech Academy of Sciences Publication Activity Database

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

    2007-01-01

    Roč. 52, č. 16 (2007), s. 295-295 ISSN 0003-0503. [Annual Meeting of the Division of Plasma Physics/49th./. Orlando , Florida, 12.11.2007-16.11.2007] R&D Projects: GA ČR GA202/06/1324; GA AV ČR KJB100430702; GA AV ČR KAN300100702; GA MŠk 1P04LA235 Institutional research plan: CEZ:AV0Z20430508 Keywords : Capillary discharge * x-ray * laser * laser-triggered * spark gap * breakdown * plasma Subject RIV: BL - Plasma and Gas Discharge Physics http://meetings.aps.org/Meeting/DPP07/Content/901

  8. Power source for inactivation of micro-organisms with partial high voltage discharge in a continuous process

    NARCIS (Netherlands)

    Creyghton, Y.; Beurskens, R.; Fiala, A.; Haan, S.W.H. de

    2002-01-01

    An electrical discharge technology is investigated as non-thermal method for inactivation of microorganisms. Potential applications include treatment of drinking water (e.g. legionella) and liquid food pasteurization (e.g. fruit juices). A strong interest exists in mild food conservation processes

  9. Remote measurement of river discharge using thermal particle image velocimetry (PIV) and various sources of bathymetric information

    Science.gov (United States)

    Legleiter, Carl; Kinzel, Paul J.; Nelson, Jonathan M.

    2017-01-01

    Although river discharge is a fundamental hydrologic quantity, conventional methods of streamgaging are impractical, expensive, and potentially dangerous in remote locations. This study evaluated the potential for measuring discharge via various forms of remote sensing, primarily thermal imaging of flow velocities but also spectrally-based depth retrieval from passive optical image data. We acquired thermal image time series from bridges spanning five streams in Alaska and observed strong agreement between velocities measured in situ and those inferred by Particle Image Velocimetry (PIV), which quantified advection of thermal features by the flow. The resulting surface velocities were converted to depth-averaged velocities by applying site-specific, calibrated velocity indices. Field spectra from three clear-flowing streams provided strong relationships between depth and reflectance, suggesting that, under favorable conditions, spectrally-based bathymetric mapping could complement thermal PIV in a hybrid approach to remote sensing of river discharge; this strategy would not be applicable to larger, more turbid rivers, however. A more flexible and efficient alternative might involve inferring depth from thermal data based on relationships between depth and integral length scales of turbulent fluctuations in temperature, captured as variations in image brightness. We observed moderately strong correlations for a site-aggregated data set that reduced station-to-station variability but encompassed a broad range of depths. Discharges calculated using thermal PIV-derived velocities were within 15% of in situ measurements when combined with depths measured directly in the field or estimated from field spectra and within 40% when the depth information also was derived from thermal images. The results of this initial, proof-of-concept investigation suggest that remote sensing techniques could facilitate measurement of river discharge.

  10. Source and fate of inorganic solutes in the Gibbon River, Yellowstone National Park, Wyoming, USA: I. Low-flow discharge and major solute chemistry

    Science.gov (United States)

    McCleskey, R. Blaine; Nordstrom, D. Kirk; Susong, David D.; Ball, James W.; Holloway, JoAnn M.

    2010-01-01

    The Gibbon River in Yellowstone National Park (YNP) is an important natural resource and habitat for fisheries and wildlife. However, the Gibbon River differs from most other mountain rivers because its chemistry is affected by several geothermal sources including Norris Geyser Basin, Chocolate Pots, Gibbon Geyser Basin, Beryl Spring, and Terrace Spring. Norris Geyser Basin is one of the most dynamic geothermal areas in YNP, and the water discharging from Norris is much more acidic (pH 3) than other geothermal basins in the upper-Madison drainage (Gibbon and Firehole Rivers). Water samples and discharge data were obtained from the Gibbon River and its major tributaries near Norris Geyser Basin under the low-flow conditions of September 2006. Surface inflows from Norris Geyser Basin were sampled to identify point sources and to quantify solute loading to the Gibbon River. The source and fate of the major solutes (Ca, Mg, Na, K, SiO2, Cl, F, HCO3, SO4, NO3, and NH4) in the Gibbon River were determined in this study and these results may provide an important link in understanding the health of the ecosystem and the behavior of many trace solutes. Norris Geyser Basin is the primary source of Na, K, Cl, SO4, and N loads (35–58%) in the Gibbon River. The largest source of HCO3 and F is in the lower Gibbon River reach. Most of the Ca and Mg originate in the Gibbon River upstream from Norris Geyser Basin. All the major solutes behave conservatively except for NH4, which decreased substantially downstream from Gibbon Geyser Basin, and SiO2, small amounts of which precipitated on mixing of thermal drainage with the river. As much as 9–14% of the river discharge at the gage is from thermal flows during this period.

  11. Fast Orbit Feedback and Beam Stability at the Swiss Light Source

    Science.gov (United States)

    Schlott, V.; Böge, M.; Keil, B.; Pollet, P.; Schilcher, T.

    2004-11-01

    A global, fast orbit feedback (FOFB) based on the digital beam position monitor (DBPM) system has been in user operation at the Swiss Light Source (SLS) since November 2003. The SVD-based correction scheme acts at a sampling rate of 4 kHz using position information from all 72 DBPM stations and applying corrections with all 72 horizontal and 72 vertical corrector magnets. As a result, the FOFB successfully damps orbit distortions, which are mainly caused by ground and girder vibrations as well as the 3-Hz booster crosstalk. It also allows fast and independent ID gap changes, which are completely transparent to all SLS users. With top-up as a regular operation mode at SLS, global beam stability on a μm-level has been achieved from days to milliseconds.

  12. Coupled radon, methane and nitrate sensors for large-scale assessment of groundwater discharge and non-point source pollution to coastal waters.

    Science.gov (United States)

    Dulaiova, Henrieta; Camilli, Richard; Henderson, Paul B; Charette, Matthew A

    2010-07-01

    We constructed a survey system of radon/methane/nitrate/salinity to find sites of submarine groundwater discharge (SGD) and groundwater nitrate input. We deployed the system in Waquoit Bay and Boston Harbor, MA where we derived SGD rates using a mass balance of radon with methane serving as a fine resolution qualitative indicator of groundwater. In Waquoit Bay we identified several locations of enhanced groundwater discharge, out of which two (Childs and Quashnet Rivers) were studied in more detail. The Childs River was characterized by high nitrate input via groundwater discharge, while the Quashnet River SGD was notable but not a significant source of nitrate. Our radon survey of Boston Harbor revealed several sites with significant SGD, out of these Inner Harbor and parts of Dorchester Bay and Quincy Bay had groundwater fluxes accompanied by significant water column nitrogen concentrations. The survey system has proven effective in revealing areas of SGD and non-point source pollution. 2009 Elsevier Ltd. All rights reserved.

  13. On an Allan variance approach to classify VLBI radio-sources on the basis of their astrometric stability

    Science.gov (United States)

    Gattano, C.; Lambert, S.; Bizouard, C.

    2017-12-01

    In the context of selecting sources defining the celestial reference frame, we compute astrometric time series of all VLBI radio-sources from observations in the International VLBI Service database. The time series are then analyzed with Allan variance in order to estimate the astrometric stability. From results, we establish a new classification that takes into account the whole multi-time scales information. The algorithm is flexible on the definition of ``stable source" through an adjustable threshold.

  14. Deactivation of Escherichia coli in a post-discharge chamber coupled to an atmospheric pressure multi-electrode DBD plasma source

    International Nuclear Information System (INIS)

    Pérez-Ruiz, V H; López-Callejas, R; De la Piedad Beneitez, A; Peña-Eguiluz, R; Mercado-Cabrera, A; Muñoz-Castro, A E; Barocio, S R; Valencia-Alvarado, R; Rodríguez-Méndez, B G

    2012-01-01

    Experimental results from applying a room pressure RF multi-electrode DBD plasma source to the inhibition of the population growth of Gram negative Escherichia coli (E. coli) within a post-discharge reactor are reported. The sample to be treated is deposited in the post-discharge chamber at about 50 mm from the plasma source outlet. Thus, the active species generated by the source are conveyed toward the chamber by the working gas flow. The plasma characterization included the measurement of the axial temperature at different distances from the reactor outlet by means of a K-type thermocouple. The resulting 294 K to 322 K temperature interval corresponded to distances between 10 mm to 1 mm respectively. As the material under treatment is placed further away, any thermal damage of the sample by the plasma is prevented. The measurement and optimization of the ozone O 3 concentration has also been carried out, provided that this is an active specie with particularly high germicide power. The effectiveness treatment of the E. coli bacteria growth inhibition by the proposed plasma source reached 99% when a 10 3 CFU/mL concentration on an agar plate had been exposed during ten minutes.

  15. Evaluating the source and seasonality of submarine groundwater discharge using a radon-222 pore water transport model

    Science.gov (United States)

    Smith, Christopher G.; Cable, Jaye E.; Martin, Jonathan B.; Roy, Moutusi

    2008-09-01

    Pore water radon ( 222Rn) distributions from Indian River Lagoon, Florida, are characterized by three zones: a lower zone where pore water 222Rn and sediment-bound radium ( 226Ra) are in equilibrium and concentration gradients are vertical; a middle zone where 222Rn is in excess of sediment-bound 226Ra and concentration gradients are concave-downward; and an upper zone where 222Rn concentration gradients are nearly vertical. These 222Rn data are simulated in a one-dimensional numerical model including advection, diffusion, and non-local exchange to estimate magnitudes of submarine groundwater discharge components (fresh or marine). The numerical model estimates three parameters, fresh groundwater seepage velocity, irrigation intensity, and irrigation attenuation, using two Monte Carlo (MC) simulations that (1) ensure the minimization algorithm converges on a global minimum of the merit function and the parameter estimates are consistent within this global minimum, and (2) provide 90% confidence intervals on the parameter estimates using the measured 222Rn activity variance. Model estimates of seepage velocities and discharge agree with previous estimates obtained from numerical groundwater flow models and seepage meter measurements and show the fresh water component decreases offshore and varies seasonally by a factor of nine or less. Comparison between the discharge estimates and precipitation patterns suggests a mean residence time in unsaturated and saturated zones on the order of 5 to 7 months. Irrigation rates generally decrease offshore for all sampling periods. The mean irrigation rate is approximately three times greater than the mean seepage velocity although the ranges of irrigation rates and seepage velocities are the same. Possible mechanisms for irrigation include density-driven convection, wave pumping, and bio-irrigation. Simulation of both advection and irrigation allows the separation of submarine groundwater discharge into fresh groundwater and

  16. Electric-discharge source of steady-state UV-VUV radiation from iodine atoms and iodine-containing molecules

    Science.gov (United States)

    Shuaibov, A. K.; Grabovaya, I. A.

    2005-07-01

    This paper presents the results of an investigation of the optical characteristics of a compact electric-discharge UV-VUV radiator based on mixtures of inert gases with iodine vapor in which the pressure of the working mixture is 250-2000 Pa. The output characteristics of the lamp were optimized as a function of the partial pressure of the inert gases and the glow-discharge current. It is established that the lamp's total radiation power in the 206-350-nm spectral region reaches 6-7 W at an efficiency of 15-20%. The operating life of the lamp in the gasostat regime was 500 h. About half the power of the UV glow-discharge radiation in this case is represented in the form of a spectral line of the iodine atom (lambda=206.2nm), while the other half is in the form of vibronic bands of iodine molecules and xenon iodide. The lamp can be recommended for use in photochemistry, medicine, and biophysics.

  17. Evaluation of the operating parameters of the liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source for elemental mass spectrometry.

    Science.gov (United States)

    Zhang, Lynn X; Manard, Benjamin T; Konegger-Kappel, Stefanie; Kappel, Stefanie Konegger; Marcus, R Kenneth

    2014-11-01

    The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as an ionization source for elemental analysis with an interdependent, parametric evaluation regarding sheath/cooling gas flow rate, discharge current, liquid flow rate, and the distance between the plasma and the sampling cone of the mass spectrometer. In order to better understand plasma processes (and different from previous reports), no form of collision/reaction processing was performed to remove molecular interferents. The evaluation was performed employing five test elements: cesium, silver, lead, lanthanum and nickel (10(-4) mol L(-1) in 1 mol L(-1) HNO3). The intensity of the atomic ions, levels of spectral background, the signal-to-background ratios, and the atomic-to-oxide/hydroxide adduct ratios were monitored in order to obtain fundamental understanding with regards to not only how each parameter effects the performance of this LS-APGD source, but also the inter-parametric effects. The results indicate that the discharge current and the liquid sampling flow rates are the key aspects that control the spectral composition. A compromise set of operating conditions was determined: sheath gas flow rate = 0.9 L min(-1), discharge current = 10 mA, solution flow rate = 10 μL min(-1), and sampling distance = 1 cm. Limits of detection (LODs) were calculated using the SBR-RSDB (signal-to-background ratio/relative standard deviation of the background) approach under the optimized condition. The LODs for the test elementals ranged from 15 to 400 ng mL(-1) for 10 μL injections, with absolute mass values from 0.2 to 4 ng.

  18. Productivity of irrigated beans due to sources of stabilized nitrogen fertilizer and controlled release

    Directory of Open Access Journals (Sweden)

    Tatiely Gomes Bernardes

    2015-12-01

    Full Text Available ABSTRACT New nitrogen fertilizers are available in the market actually, however, does not have results on the efficiency of the Cerrado conditions. With that objective of this study was to evaluate the effect of urea including stabilized and controlled release urea on yield of irrigated common beans (Phaseolus vulgaris L in no-tillage system. The experiment was conducted in the winter crop, at Embrapa Arroz e Feijão, in Santo Antônio de Goiás, State of Goiás, Brazil. The experimental design was randomized blocks, with five replicates. Treatments consisted of five N sources (urea, urea + NBPT, urea + polymer, ammonium sulphate, and ammonium nitrate and a control (without N being applied 20 kg ha-1 of N at sowing and 80 kg ha-1 onf N in topdressing. We evaluated the chlorophyll content in leaves of common beans, the leaf N content and dry mass weight (MSPA in the flowering of common beans, the number of pods per plant, number of grains per pod, mass of 100 grains, grain yield and final stand of the common beans. The sources of nitrogen fertilizer did not influence, leaf N content, the mass of MSPA and the relative chlorophyll index of common beans. The use of polymerized urea and urea with urease inhibitor, did not produce increases in the number of grains per pod, number of pods per plant, mass of 100 grains and common beans yield compared to traditional sources of N, urea, ammonium sulfate and ammonium nitrate.

  19. A qualitative study of patient involvement in medicines management after hospital discharge: an under-recognised source of systems resilience.

    Science.gov (United States)

    Fylan, Beth; Armitage, Gerry; Naylor, Deirdre; Blenkinsopp, Alison

    2017-11-16

    There are risks to the safety of medicines management when patient care is transferred between healthcare organisations, for example, when a patient is discharged from hospital. Using the theoretical concept of resilience in healthcare, this study aimed to better understand the proactive role that patients can play in creating safer, resilient medicines management at a common transition of care. Qualitative interviews with 60 cardiology patients 6 weeks after their discharge from 2 UK hospitals explored patients' experiences with their discharge medicines. Data were initially subjected to an inductive thematic analysis and a subsequent theory-guided deductive analysis. During interviews 23 patients described medicines management resilience strategies in two main themes: identifying system vulnerabilities; and establishing self-management strategies. Patients could anticipate problems in the system that supplied them with medicines and took specific actions to prevent them. They also identified when errors had occurred both before and after medicines had been supplied and took corrective action to avoid harm. Some reported how they had not foreseen problems or experienced patient safety incidents. Patients recounted how they ensured information about medicines changes was correctly communicated and acted upon, and described their strategies to enhance their own reliability in adherence and resource management. Patients experience the impact of vulnerabilities in the medicines management system across the secondary-primary care transition but many are able to enhance system resilience through developing strategies to reduce the risk of medicines errors occurring. Consequently, there are opportunities-with caveats-to elicit, develop and formalise patients' capabilities which would contribute to safer patient care and more effective medicines management. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights

  20. Stabilization

    Directory of Open Access Journals (Sweden)

    Muhammad H. Al-Malack

    2016-07-01

    Full Text Available Fuel oil flyash (FFA produced in power and water desalination plants firing crude oils in the Kingdom of Saudi Arabia is being disposed in landfills, which increases the burden on the environment, therefore, FFA utilization must be encouraged. In the current research, the effect of adding FFA on the engineering properties of two indigenous soils, namely sand and marl, was investigated. FFA was added at concentrations of 5%, 10% and 15% to both soils with and without the addition of Portland cement. Mixtures of the stabilized soils were thoroughly evaluated using compaction, California Bearing Ratio (CBR, unconfined compressive strength (USC and durability tests. Results of these tests indicated that stabilized sand mixtures could not attain the ACI strength requirements. However, marl was found to satisfy the ACI strength requirement when only 5% of FFA was added together with 5% of cement. When the FFA was increased to 10% and 15%, the mixture’s strength was found to decrease to values below the ACI requirements. Results of the Toxicity Characteristics Leaching Procedure (TCLP, which was performed on samples that passed the ACI requirements, indicated that FFA must be cautiously used in soil stabilization.

  1. Arsenic-containing soil from geogenic source in Hong Kong: Leaching characteristics and stabilization/solidification.

    Science.gov (United States)

    Li, Jiang-Shan; Beiyuan, Jingzi; Tsang, Daniel C W; Wang, Lei; Poon, Chi Sun; Li, Xiang-Dong; Fendorf, Scott

    2017-09-01

    Geogenic sources of arsenic (As) have aroused extensive environmental concerns in many countries. This study evaluated the vertical profiles, leaching characteristics, and surface characteristics of As-containing soils in Hong Kong. The results indicated that elevated levels of As (486-1985 mg kg -1 ) were mostly encountered in deeper layer (15-20 m below ground). Despite high concentrations, geogenic As displayed a high degree of chemical stability in the natural geochemical conditions, and there was minimal leaching of As in various leaching tests representing leachability, mobility, phytoavailability, and bioaccessibility. Microscopic/spectroscopic investigations suggested that As in the soils was predominantly present as As(V) in a coordination environment with Fe oxides. Sequential extraction indicated that the majority of As were strongly bound with crystalline Fe/Al oxides and residual phase. Yet, uncertainties may remain with potential As exposure through accidental ingestion and abiotic/biotic transformation due to changes in geochemical conditions. Hence, the effectiveness of stabilization/solidification (S/S) treatment was evaluated. Although the leached concentrations of As from the S/S treated soils increased to varying extent in different batch leaching tests due to the increase in alkalinity, the mobility of As was considered very low based on semi-dynamic leaching test. This suggested that As immobilization in the S/S treated soils was predominantly dependent on physical encapsulation by interlocking framework of hydration products, which could also prevent potential exposure and allow controlled utilization of S/S treated soils as monolithic materials. These results illustrate the importance of holistic assessment and treatment/management of As-containing soils for enabling flexible future land use. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Relict thermokarst carbon source kept stable within gas hydrate stability zone of the South Kara Sea

    Science.gov (United States)

    Portnov, A.; Mienert, J.; Winsborrow, M.; Vadakkepuliyambatta, S.; Semenov, P.

    2017-12-01

    Substantial shallow sources of carbon can exist in the South Kara Sea shelf, extending offshore from the permafrost areas of Yamal Peninsula and the Polar Ural coast. Our study presents new evidence for >250 buried relict thermokarst units. These amalgamated thawing wedges formed in the uppermost permafrost of the past and are still recognizable in today's non-permafrost areas. Part of these potential carbon reservoirs are kept stable within the South Kara Sea gas hydrate stability zone (GHSZ). We utilize an extensive 2D high-resolution seismic dataset, collected in the South Kara Sea in 2005-2006 by Marine Arctic Geological Expedition (MAGE), to map distinctive U-shaped units that are acoustically transparent. These units appear all over the study area in water depths 50-250 m. Created by thermal erosion into Cretaceous-Paleogene bedrock, they are buried under the younger glacio-marine deposits and reach hundreds of meters wide and up to 100 meters thick. They show the characteristics of relict thermokarst, generated during ancient episode(s) of sea level regression of the South Kara Sea. These thermokarst units are generally limited by the Upper Regional Unconformity, which is an erosional horizon created by several glaciation events during the Pleistocene. On land, permafrost is known to sequester large volumes of carbon, half of which is concentrated within thermokarst structures. Based on modern thermokarst analogues we demonstrate with our study that a significant amount of organic carbon can be stored under the Kara Sea. To assess the stability of these shallow carbon reservoirs we carried out GHSZ modeling, constrained by geochemical analyses, temperature measurements and precise bathymetry. This revealed a significant potential for a GHSZ in water depths >225 m. The relict thermokast carbon storage system is stable under today's extremely low bottom water temperatures ( -1.7 °C) that allows for buried GHSZ, located tens of meters below the seabed

  3. Graywater Discharges from Vessels

    Science.gov (United States)

    2011-11-01

    both sewage and graywater, or sewage collected from “ honey dipper” trucks, which may contain far less graywater, depending on the source (See... crystal clean effluent discharge. As a reference, Cruiseliners equipped with Scanship AWP systems has obtained continous discharge permits in Hawaii and

  4. Paediatric vaginal discharge

    African Journals Online (AJOL)

    Vaginal discharge in the prepubertal patient is a common symptom, and can be a source of distress for the caregiver and con- cern for the healthcare worker. Several factors predispose these patients to the development of recurrent vaginal discharge. Unless noticed by the caregiver, this problem can persist for long periods ...

  5. Using discharge data to reduce structural deficits in a hydrological model with a Bayesian inference approach and the implications for the prediction of critical source areas

    Science.gov (United States)

    Frey, M. P.; Stamm, C.; Schneider, M. K.; Reichert, P.

    2011-12-01

    A distributed hydrological model was used to simulate the distribution of fast runoff formation as a proxy for critical source areas for herbicide pollution in a small agricultural catchment in Switzerland. We tested to what degree predictions based on prior knowledge without local measurements could be improved upon relying on observed discharge. This learning process consisted of five steps: For the prior prediction (step 1), knowledge of the model parameters was coarse and predictions were fairly uncertain. In the second step, discharge data were used to update the prior parameter distribution. Effects of uncertainty in input data and model structure were accounted for by an autoregressive error model. This step decreased the width of the marginal distributions of parameters describing the lower boundary (percolation rates) but hardly affected soil hydraulic parameters. Residual analysis (step 3) revealed model structure deficits. We modified the model, and in the subsequent Bayesian updating (step 4) the widths of the posterior marginal distributions were reduced for most parameters compared to those of the prior. This incremental procedure led to a strong reduction in the uncertainty of the spatial prediction. Thus, despite only using spatially integrated data (discharge), the spatially distributed effect of the improved model structure can be expected to improve the spatially distributed predictions also. The fifth step consisted of a test with independent spatial data on herbicide losses and revealed ambiguous results. The comparison depended critically on the ratio of event to preevent water that was discharged. This ratio cannot be estimated from hydrological data only. The results demonstrate that the value of local data is strongly dependent on a correct model structure. An iterative procedure of Bayesian updating, model testing, and model modification is suggested.

  6. Preparation, physical characterization, and stability of Ferrous-Chitosan microcapsules using different iron sources

    Science.gov (United States)

    Handayani, Noer Abyor; Luthfansyah, M.; Krisanti, Elsa; Kartohardjono, Sutrasno; Mulia, Kamarza

    2017-11-01

    Dietary modification, supplementation and food fortification are common strategies to alleviate iron deficiencies. Fortification of food is an effective long-term approach to improve iron status of populations. Fortification by adding iron directly to food will cause sensory problems and decrease its bioavailability. The purpose of iron encapsulation is: (1) to improve iron bioavailability, by preventing oxidation and contact with inhibitors and competitors; and (2) to disguise the rancid aroma and flavor of iron. A microcapsule formulation of two suitable iron compounds (iron II fumarate and iron II gluconate) using chitosan as a biodegradable polymer will be very important. Freeze dryer was also used for completing the iron microencapsulation process. The main objective of the present study was to prepare and characterize the iron-chitosan microcapsules. Physical characterization, i.e. encapsulation efficiency, iron loading capacity, and SEM, were also discussed in this paper. The stability of microencapsulated iron under simulated gastrointestinal conditions was also investigated, as well. Both iron sources were highly encapsulated, ranging from 71.5% to 98.5%. Furthermore, the highest ferrous fumarate and ferrous gluconate loaded were 1.9% and 4.8%, respectively. About 1.04% to 9.17% and 45.17% to 75.19% of Fe II and total Fe, were released in simulated gastric fluid for two hours and in simulated intestinal fluid for six hours, respectively.

  7. Evaluation of a pulsed glow discharge time-of-flight mass spectrometer as a detector for gas chromatography and the influence of the glow discharge source parameters on the information volume in chemical speciation analysis.

    Science.gov (United States)

    Fliegel, Daniel; Fuhrer, Katrin; Gonin, Marc; Günther, Detlef

    2006-09-01

    The figures of merit of a pulsed glow discharge time-of-flight mass spectrometer (GD-TOFMS) as a detector for gas chromatography (GC) analysis were evaluated. The mass resolution for the GD-TOFMS was determined on FWHM in the high mass range (208Pb+) as high as 5,500. Precision of 400 subsequent analyses was calculated on 63Cu+ to be better than 1% RSD with no significant drift over the time of the analysis. Isotope precision based on the 63Cu+/65Cu+ ratio over 400 analyses was 1.5% RSD. The limits of detection for gaseous analytes (toluene in methanol as solvent) were determined to be as low as several hundred ppb or several hundred pg absolute without using any pre-concentration technique. Furthermore, the different GD source parameters like capillary distance, cathode-anode spacing, and GD source pressure with regards to the accessible elemental, structural, and molecular information were evaluated. It was demonstrated that each of these parameters has severe influence on the ratio of elemental, structural, and parent molecular information in chemical speciation analysis.

  8. Active beam position stabilization of pulsed lasers for long-distance ion profile diagnostics at the Spallation Neutron Source (SNS).

    Science.gov (United States)

    Hardin, Robert A; Liu, Yun; Long, Cary; Aleksandrov, Alexander; Blokland, Willem

    2011-02-14

    A high peak-power Q-switched laser has been used to monitor the ion beam profiles in the superconducting linac at the Spallation Neutron Source (SNS). The laser beam suffers from position drift due to movement, vibration, or thermal effects on the optical components in the 250-meter long laser beam transport line. We have designed, bench-tested, and implemented a beam position stabilization system by using an Ethernet CMOS camera, computer image processing and analysis, and a piezo-driven mirror platform. The system can respond at frequencies up to 30 Hz with a high position detection accuracy. With the beam stabilization system, we have achieved a laser beam pointing stability within a range of 2 μrad (horizontal) to 4 μrad (vertical), corresponding to beam drifts of only 0.5 mm × 1 mm at the furthest measurement station located 250 meters away from the light source.

  9. Active stabilization of alkali-atom vapor density with a solid-state electrochemical alkali-atom source.

    Science.gov (United States)

    Kang, Songbai; Mott, Russell P; Mis, Allison V; Roper, Christopher S; Donley, Elizabeth A; Kitching, John

    2018-02-05

    We report a demonstration of vapor-phase Rubidium (Rb) density stabilization in a vapor cell using a solid-state electrochemical Rb source device. Clear Rb density stabilization is observed. Further demonstrations show that the temperature coefficient for Rb density can be reduced more than 100 times when locked and the device's power consumption is less than 10 mW. Preliminary investigation of the locking dynamic range shows that the Rb density is well stabilized when the initial density is five times higher (33 × 10 9 /cm 3 ) than the set point density (6 × 10 9 /cm 3 ). Active stabilization with this device is of high interest for portable cold-atom microsystems where large ambient temperature working ranges and low power consumption are required.

  10. 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

  11. Nitrogen discharge pathways in vegetable production as non-point sources of pollution and measures to control it.

    Science.gov (United States)

    Min, Ju; Shi, Weiming

    2018-02-01

    Discharge of nitrogen (N) from fertilizers applied to vegetables is becoming a serious environmental problem. In a field experiment involving a celery-tomato-fallow-lettuce rotation, leaching was the primary pathway of N loss (56.1±0.4% of the total), followed, in descending order, by runoff (11.7±0.3%), N 2 O emissions (1.6±0.1%), and volatilization of ammonia (0.5±0.1%). Decreasing the traditional dose of N by 40% in each growth season decreased N leaching by 22.3±4.5, 39.8±6.7, 40.3±2.9 and 27.4±3.6% in celery, tomato, fallow and lettuce seasons, respectively, without any yield loss, and modifying the rotation to include a leguminous crop reduced the N leaching by 72±2, 40±3, 24±2 and 13±1% in each season, respectively, without any economic impact. These measures decreased annual N leaching by 36±4%. A combination of the eco-ditches and wetland paddy fields adjacent to the vegetable plot led to annual N removal efficiency of 73±6% in runoff. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. 77 FR 19282 - Draft NPDES General Permit for Discharges From the Oil and Gas Extraction Point Source Category...

    Science.gov (United States)

    2012-03-30

    ... not New Sources, the United States Fish and Wildlife Service (FWS) concurred with EPA's finding that... study for produced water, intake velocity limit for cooling water intake structures from new facilities... adversely affect an Essential Fish Habitat is subject to the consultation provisions of the Manguson-Stevens...

  13. A dielectric barrier discharge based ion source for a sensitive and versatile chemical ionization time of flight mass spectrometer instrument using the negative ion mode

    Science.gov (United States)

    Albrecht, Sascha; Afchine, Armin; Barthel, Jochen; Dick, Markus; Rongen, Heinz; Franzke, Joachim; Stroh, Fred; Benter, Thorsten

    2017-04-01

    Chemical ionization mass spectrometry (CIMS) provides high sensitivity for ultra-sensitive trace gas measurements in the atmosphere. The presented ion source is used to replace radioactive Po ion sources. First in-field test runs have been done using an airborne instrument flown on the StratoClim campaign in Greece, Kalamata 2016. Especially stratospheric measurements at ambient pressures lower than 100 hPa require improved sensitivity. Therefore, a chemical ionization (CI) time-of-flight (TOF) instrument using a dielectric barrier discharge (DBD) ion source and a high-transmission transfer stage has been set-up and characterized. A new concept including the ion molecule reaction (IMR) zone inside an ion funnel is used. The focus will be on the brilliant DBD ion source, which also can be used to generate ion precursors in the plasma. Thereby multiple reactants can be generated having a versatile ion source. To finally judge the brilliance of the DBD ion source it is compared to a 10 mCi Po ion source. These measurements are highlighting that even more ions are generated in the DBD ion source compared to a 10 mCi Po ion source. However, first measurements with good sensitivity have been made, employing the CIMS instrument described. The analyte gas is introduced into the first ion funnel and mixed with the ion source gas flow. It has been discovered that the mixing in the IMR funnel is critical in terms of sensitivity and was therefore optimized. The ion funnel achieves a transmission of 40% working at 50 hPa pressure and using a gas flow of 1 slm. The complete transfer stage achieves a high transmission of around 10 % for gas phase ions and therefore enables a high sensitivity combined with the brilliant DBD ion source. A detection limit better than 100 pptV was determined for SO2 using CO3- ions. Further-on a fast exchange of the reactants is possible. NO3-, CO3-, I- and SF6- have been successfully tested and can be generated in the DBD from low ppm or even ppb

  14. The use of stable isotopes to determine the water and nitrogen sources of Casuarina glauca at a saline discharge site

    International Nuclear Information System (INIS)

    Cramer, V.; Stewart, G. R.

    1997-01-01

    Full text: The concentration of salt in the root zone of plants due to root water uptake is a major concern in the long term success of tree planting to manage saline groundwater tables. Increased concentration of salts in the root zone will not only limit water availability, but may also interfere with the uptake of nutrients, such as nitrogen, through either ionic or osmotic effects. At a highly saline site in south-east Queensland, natural abundance stable isotopes have been used to determine the soil sources of both water and nitrogen used by Casuarina glauca planted at the site, including the role of nitrogen fixation in the nitrogen nutrition of the trees. At this site, the dominant source of water for C. glauca originated from the groundwater table, with an annual average of greater than 60% of tree water derived from this source. However, on a monthly basis this proportion varied considerably. Trees readily utilised large summer rainfall events. But showed a smaller, or delayed response, to winter rainfall events. Soil nitrogen levels (combined NH 4 , and NO 3 ) ranged widely between plots, with the majority of soil nitrogen present in the upper soil layers. The availability of soil N to plants was estimated using the ion exchange resin bag techniques with results reflecting the influence of soil moisture and leaching events on NH 4 and NO 3 availability. Tree δ 15 N signatures reflected soil N availability, with enriched values in high N soils. Soil δ 15 N signatures were compared to those of trees to determine whether nitrogen was acquired from mineral sources or through nitrogen fixation

  15. Application of the Vapor-phase Multi-stage CMD Test to Characterize Contaminant Mass Discharge Associated with Volatile Organic Contaminant Sources in the Vadose Zone

    Science.gov (United States)

    Brusseau, M. L.; Mainhagu, J.; Morrison, C. N.; Carroll, K. C.

    2014-12-01

    Vapor-phase multi-stage contaminant mass discharge (CMD) tests were conducted at two field sites to measure mass discharge associated with contaminant sources located in the vadose zone. A CMD of 32 g/d was obtained for a site at which soil vapor extraction (SVE) has been in operation for approximately 6 years. The behavior exhibited for the vapor extractions conducted at this site suggests that there is unlikely to be a significant mass of non-vapor-phase contaminant (e.g., DNAPL, sorbed phase) present in the advective domains, and that most remaining mass is likely located in poorly accessible domains. Given the conditions for this site, this remaining mass is hypothesized to be associated with the low-permeability (and higher water saturation) region in the vicinity of the saturated zone and capillary fringe. This is supported by the results of a sediment-coring effort conducted prior to the CMD test. A CMD of 270 g/d was obtained for a site for which there were no prior SVE operations. The behavior exhibited for the vapor extractions conducted at this site suggest that non-vapor-phase contaminant mass (e.g., DNAPL) may be present in the advective domains. This is consistent with the results of prior characterization activities conducted at the site. Hence, the asymptotic conditions observed for this site most likely derive from a combination of rate-limited mass transfer from DNAPL (and sorbed) phases present in the advective domain as well as mass residing in lower-permeability ("non-advective") regions. The CMD values obtained from the tests were used in conjunction with a recently developed vapor-discharge tool to evaluate the impact of the measured CMDs on groundwater quality.

  16. New Evidence That Nonlinear Source-Filter Coupling Affects Harmonic Intensity and fo Stability During Instances of Harmonics Crossing Formants.

    Science.gov (United States)

    Maxfield, Lynn; Palaparthi, Anil; Titze, Ingo

    2017-03-01

    The traditional source-filter theory of voice production describes a linear relationship between the source (glottal flow pulse) and the filter (vocal tract). Such a linear relationship does not allow for nor explain how changes in the filter may impact the stability and regularity of the source. The objective of this experiment was to examine what effect unpredictable changes to vocal tract dimensions could have on fo stability and individual harmonic intensities in situations in which low frequency harmonics cross formants in a fundamental frequency glide. To determine these effects, eight human subjects (five male, three female) were recorded producing fo glides while their vocal tracts were artificially lengthened by a section of vinyl tubing inserted into the mouth. It was hypothesized that if the source and filter operated as a purely linear system, harmonic intensities would increase and decrease at nearly the same rates as they passed through a formant bandwidth, resulting in a relatively symmetric peak on an intensity-time contour. Additionally, fo stability should not be predictably perturbed by formant/harmonic crossings in a linear system. Acoustic analysis of these recordings, however, revealed that harmonic intensity peaks were asymmetric in 76% of cases, and that 85% of fo instabilities aligned with a crossing of one of the first four harmonics with the first three formants. These results provide further evidence that nonlinear dynamics in the source-filter relationship can impact fo stability as well as harmonic intensities as harmonics cross through formant bandwidths. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  17. Influence of the electrode wear on the EUV generation of a discharge based extreme ultraviolet light source

    Science.gov (United States)

    Vieker, Jochen; Bergmann, Klaus

    2017-08-01

    Reliability and a long maintenance interval are major requirements for the industrial use of an extreme ultraviolet (EUV) source. In this paper we present results on the influence of the electrode erosion on the EUV generation and its lifetime limiting characteristics. The geometry of the electrodes and their influence on the gas pressure distribution within the electrode system have been found to be the key variables to characterize the regime of operation. This better understanding allows for an optimization of device parameters (e.g. gas flow or pulse energy) to counteract the erosion process, in order to increase the maintenance interval and EUV output. The EUV source under investigation is based on a hollow cathode triggered pinch plasma. A new trigger concept is introduced that enables free adjustment of the gas pressure during operation, thus enabling the operation with a high conversion efficiency of up to  >0.7 %/2πsr at 13.5 nm and 2% bandwidth. The efficiency for the peak brilliance is up to ~2.6 W kW-1 mm-2sr-1 while the maximum electrical input power of the system is 15 kW.

  18. A Novel Partial Discharge Ultra-High Frequency Signal De-Noising Method Based on a Single-Channel Blind Source Separation Algorithm

    Directory of Open Access Journals (Sweden)

    Liangliang Wei

    2018-02-01

    Full Text Available To effectively de-noise the Gaussian white noise and periodic narrow-band interference in the background noise of partial discharge ultra-high frequency (PD UHF signals in field tests, a novel de-noising method, based on a single-channel blind source separation algorithm, is proposed. Compared with traditional methods, the proposed method can effectively de-noise the noise interference, and the distortion of the de-noising PD signal is smaller. Firstly, the PD UHF signal is time-frequency analyzed by S-transform to obtain the number of source signals. Then, the single-channel detected PD signal is converted into multi-channel signals by singular value decomposition (SVD, and background noise is separated from multi-channel PD UHF signals by the joint approximate diagonalization of eigen-matrix method. At last, the source PD signal is estimated and recovered by the l1-norm minimization method. The proposed de-noising method was applied on the simulation test and field test detected signals, and the de-noising performance of the different methods was compared. The simulation and field test results demonstrate the effectiveness and correctness of the proposed method.

  19. Electric Vehicles Integration in the Electric Power System with Intermittent Energy Sources - The Charge/Discharge infrastructure

    DEFF Research Database (Denmark)

    Marra, Francesco

    increased levels of non-dispatchable and fluctuating energy sources, as well as additional power demand due to EV charging. If the charging of EVs can be intelligently managed, several advantages can be offered to the power system. How useful coordinated EV charging can be, in combination with RES...... storage solution to facilitate PV integration in LV distribution grids. In this context, the storage capabilities of EV charging stations are analyzed. Two concepts of stations are investigated: public charging station, to accommodate the parallel charging of EVs at public locations, and private charging...... stations at private homes. The coordination of EV load of public or private charging stations creates benefits in feeders with PV. A method based on voltage sensitivity analysis is proposed to evaluate the influence of EV load coordination at different locations in the grid. Time-series simulations...

  20. Research on spectrum stability technology in a NaI(Tl) spectrometer with embed 241 Am source

    International Nuclear Information System (INIS)

    Dai Chuanbo; Luo Peng; Zhu Guohua; Chen Xianglei; Zou Tao; Liao Wu

    2012-01-01

    Several methods have been researched to improve the performance of the 241 Am reference peak in Na(Tl) γ spectrometer about how to make 241 Am source, how to design and machining the collimator. The reference peak has the performance with 3.53 MeV γ equivalence energy, resolution of 2.5%, and count rate stability of 0.1%, which provides a stable reference for the Na(Tl) γ spectrometers in engineering. (authors)

  1. Modelling electric discharge chemistry

    International Nuclear Information System (INIS)

    McFarlane, J.; Wren, J.C.

    1991-07-01

    The chemistry occurring in a electric discharge was modelled to predict how it would be influenced by discharge conditions. The discharge was characterized by a calculated Boltzmann electron-energy distribution, from which rate constants for electron-molecule processes in air were determined. These rate constants were used in a chemical kinetics calculation that also included reactions between neutral molecules, ions, free radicals and electronically excited species. The model describes how the discharge chemistry was influenced by humidity, electric field, electron number density, and concentrations of key reagents identified in the study. The use of an electric discharge to destroy airborne contaminant molecules was appraised, the targeted contaminants being CF 2 Cl 2 , HCN, and SO 2 . The modelling results indicate that an electric discharge should be able to remove HCN and CF 2 Cl 2 effectively, especially if the discharge conditions have been optimized. Effective destruction is achieved with a moderate electric field (over 1 x 10 -15 V.cm 2 ), a substantial electron number density (over 1 x 10 12 cm -3 ), and the presence of H 2 0 in the process air. The residence time in the discharge was also shown to be important in contaminant destruction. An attempt was made to explain the results of the electric discharge abatement of SO 2 , a component of a simulated flue-gas mixture. Results from the model indicate that the discharge parameters that increase the concentration of hydroxyl radical also increase the rate of decomposition of SO 2 . An objective of the study was to explain the apparent enhancement of SO 2 destruction by the presence of a small amount of NO 2 . It was thought that a likely explanation would be the stabilization of HOSO 2 , an important intermediate in the oxidation of SO 2 by NO 2 . (49 figs., 14 tabs., 75 refs.)

  2. 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%.

  3. Wheat bran extracts: a potent source of natural antioxidants for the stabilization of canola oil

    Directory of Open Access Journals (Sweden)

    Shahid Chatha, Shahzad Ali

    2011-06-01

    Full Text Available In the present work, the antioxidant activity of different solvent extracts of wheat (var. Inqalab 91 bran was evaluated following different antioxidant assays using canola oil as the oxidation substrate. The bran samples were extracted with 80% and 100% methanol and acetone. A preliminary assessment of the antioxidant activity of the 80 and 100% acetone and methanolic extracts of wheat bran was done by the measurement of % inhibition of peroxidation in a linoleic acid system, total phenolic contents (TPC and bleachability of β-carotene in the linoleic acid system. Additionally, the canola oil samples were stabilized with crude concentrated extracts and subjected to ambient aging (6 months. The extent of oxidative deterioration was followed by the measurement of peroxide-, p-anisidine-, conjugated dienes-, and trienes- values. The results of ambient stored samples revealed a significant improvement in these oxidation parameters. The overall order of antioxidant activity of the extracts as determined by various antioxidant assays was determined to be; 80% methanolic extract > 100% methanolic extract > 80% acetone extracts . 100% acetone extract. The results of the present comprehensive analysis demonstrate that extracts of the wheat bran indigenous to Pakistan are a viable source of natural antioxidants and might be exploited for commercial and neutraceutical applications.

    En el presente trabajo la actividad antioxidante de diferentes extractos obtenidos con disolventes del salvado de trigo (var. Inqalab 91 fue evaluada mediante diferentes ensayos antioxidantes y aceite de canola como substrato de oxidación. Las muestras de salvado fueron extraídas con metanol y acetona al 80% y al 100%. La evaluación preliminar de la actividad antioxidante de los extractos de metanol y de acetona al 80% y 100% fue hecha mediante la medida del % de inhibición de la peroxidación en un sistema con ácido linoleico, el contenido total de fenoles

  4. 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 L; 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. © 2013.

  5. Impact of source and level of calcium fortification on the heat stability of reconstituted skim milk powder.

    Science.gov (United States)

    Vyas, H K; Tong, P S

    2004-05-01

    Calcium enrichment of food and dairy products has gained interest with the increased awareness about the importance of higher calcium intake. Calcium plays many important roles in the human body. Dairy products are an excellent source of dietary calcium, which can be further fortified with calcium salts to achieve higher calcium intake per serving. However, the addition of calcium salts can destabilize food systems unless conditions are carefully controlled. The effect of calcium fortification on the heat stability of reconstituted skim milk was evaluated, using reconstituted skim milks with 2 protein levels: 1.75 and 3.5% (wt/wt) prepared using low and high heat powders. Calcium carbonate, phosphate, lactate, and citrate were used for fortification at 0.15, 0.18, and 0.24% (wt/wt). Each sample was analyzed for solubility, heat stability, and pH. The addition of phosphate and lactate salts lowered the pH of milk, citrate did not have any major effect, and carbonate for the 1.75% protein samples increased the pH. In general, changes in solubility and heat stability were associated with changes in pH. Calcium addition decreased the solubility and heat stability. However, interestingly, the presence of carbonate salt greatly increased the heat stability for 1.75% protein samples. This is due to the neutralizing effect of calcium carbonate when it goes into solution. The results suggested that the heat stability of milk can be affected by the type of calcium salt used. This may be applied to the development of milk-based calcium enriched beverages.

  6. Ultrastable offset-locked frequency-stabilized heterodyne laser source with water cooling.

    Science.gov (United States)

    Yang, Hongxing; Yang, Ruitao; Hu, Pengcheng; Tan, Jiubin

    2017-11-20

    An ultrastable frequency-stabilized He-Ne laser with a water-cooling structure has been developed for a high-speed and high-accuracy heterodyne interferometer. To achieve high frequency stability and reproducibility, a two-mode He-Ne laser was offset locked to an iodine-stabilized laser. An improved synchronous multi-cycle offset frequency-measurement method with a gate time of an integer multiple of the modulation period was employed to remove the frequency-modulation effect on the offset-frequency counter. A water-cooling structure based on the double-helix structure was established to provide a stable and low-temperature working environment. This structure can remarkably reduce the frequency instability arising from the environmental temperature variation and the thermal pollution released from the laser to the environment. The experimental results indicate that the frequency stability according to the Allen variance is better than 2.3×10 -11 (τ=10  s) and the frequency reproducibility is better than 4.5×10 -10 .

  7. Preliminary Assessment of Potential for Metal-Ligand Speciation in Aqueous Solution via the Liquid Sampling-Atmospheric Pressure Glow Discharge (LS-APGD) Ionization Source: Uranyl Acetate.

    Science.gov (United States)

    Zhang, Lynn X; Manard, Benjamin T; Powell, Brian A; Marcus, R Kenneth

    2015-07-21

    The determination of metals, including the generation of metal-ligand speciation information, is essential across a myriad of biochemical, environmental, and industrial systems. Metal speciation is generally affected by the combination of some form of chromatographic separation (reflective of the metal-ligand chemistry) with element-specific detection for the quantification of the metal composing the chromatographic eluent. Thus, the identity of the metal-ligand is assigned by inference. Presented here, the liquid sampling-atmospheric pressure glow discharge (LS-APGD) is assessed as an ionization source for metal speciation, with the uranyl ion-acetate system used as a test system. Molecular mass spectra can be obtained from the same source by simple modification of the sustaining electrolyte solution. Specifically, chemical information pertaining to the degree of acetate complexation of uranyl ion (UO2(2+)) is assessed as a function of pH in the spectral abundance of three metallic species: inorganic (nonligated) uranyl, UO2Ac(H2O)n(MeOH)m(+), and UO2Ac2(H2O)n(MeOH)(m)H(+) (n = 1, 2, 3, ...; m = 1, 2, 3, ...). The product mass spectra are different from what are obtained from electrospray ionization sources that have been applied to this system. The resulting relationships between the speciation and pH values have been compared to calculated concentrations of the corresponding uranyl species: UO2(2+), UO2Ac(+), UO2Ac2. The capacity for the LS-APGD to affect both atomic mass spectra and structurally significant spectra for organometallic complexes is a unique and potentially powerful combination.

  8. Influence of the configuration of the magnetic filter field on the discharge structure in the RF driven negative ion source prototype for fusion

    Science.gov (United States)

    Lishev, S.; Schiesko, L.; Wünderlich, D.; Fantz, U.

    2017-08-01

    The study provides results for the influence of the filter field topology on the plasma parameters in the RF prototype negative ion source for ITER NBI. A previously developed 2D fluid plasma model of the prototype source was extended towards accounting for the particles and energy losses along the magnetic field lines and the presence of a magnetic field in the driver which is the case at the BATMAN and ELISE test-beds. The effect of the magnetic field in the driver is shown for the magnetic field configuration of the prototype source (i.e. a magnetic field produced by an external magnet frame) by comparison of plasma parameters without and with the magnetic field in the driver and for different axial positions of the filter. Since the ELISE-like magnetic field (i.e. a magnetic field produced by a current flowing through the plasma grid) is a new feature planned to be installed at the BATMAN test-bed, its effect on the discharge structure was studied for different strengths of the magnetic field. The obtained results show for both configurations of the magnetic filter the same main features in the patterns of the plasma parameters in the expansion chamber: a strong axial drop of the electron temperature and the formation of a groove accompanied with accumulation of electrons in front of the plasma grid. The presence of a magnetic field in the driver has a local impact on the plasma parameters: the formation of a second groove of the electron temperature in the case of BATMAN (due to the reversed direction of the filter field in the driver) and a strong asymmetry of the electron density. Accounting for the additional losses in the third dimension suppresses the drifts across the magnetic field and, thus, the variations of the electron density in the expansion chamber are less pronounced.

  9. Equilibrium and Stability Properties of Low Aspect Ratio Mirror Systems: from Neutron Source Design to the Parker Spiral

    Science.gov (United States)

    Peterson, Ethan; Anderson, Jay; Clark, Mike; Egedal, Jan; Endrizzi, Douglass; Flanagan, Ken; Harvey, Robert; Lynn, Jacob; Milhone, Jason; Wallace, John; Waleffe, Roger; Mirnov, Vladimir; Forest, Cary

    2017-10-01

    Equilibrium reconstructions of rotating magnetospheres in the lab are computed using a user-friendly extended Grad-Shafranov solver written in Python and various magnetic and kinetic measurements. The stability of these equilibria are investigated using the NIMROD code with two goals: understand the onset of the classic ``wobble'' in the heliospheric current sheet and demonstrating proof-of-principle for a laboratory source of high- β turbulence. Using the same extended Grad-Shafranov solver, equilibria for an axisymmetric, non-paraxial magnetic mirror are used as a design foundation for a high-field magnetic mirror neutron source. These equilibria are numerically shown to be stable to the m=1 flute instability, with higher modes likely stabilized by FLR effects; this provides stability to gross MHD modes in an axisymmetric configuration. Numerical results of RF heating and neutral beam injection (NBI) from the GENRAY/CQL3D code suite show neutron fluxes promising for medical radioisotope production as well as materials testing. Synergistic effects between NBI and high-harmonic fast wave heating show large increases in neutron yield for a modest increase in RF power. work funded by DOE, NSF, NASA.

  10. The study of the influence of stabilizing devices on the pressure pulsations at the free discharge of water through the turbine

    Directory of Open Access Journals (Sweden)

    Platonov Dmitry

    2017-01-01

    Full Text Available The free discharge through the turbine is applied in the course of construction of hydro power plant or in case of excessive water inflow during floods or emergency situations. The experimental and numerical investigation of flow-induced pressure pulsations in hydraulic turbine draft tube at free discharge was performed using a special setup for suppression of draft tube surge. Such special equipment in draft tube cone as fins and “spider”-like units was considered for reducing these pressure pulsations. The paper considers influence of these units on vortex structures and pressure pulsations in the draft tube in several regimes.

  11. Effects of a poloidally asymmetric ionization source on toroidal drift wave stability and the generation of sheared parallel flow

    International Nuclear Information System (INIS)

    Ware, A.S.; Diamond, P.H.

    1993-01-01

    The effects of a poloidally asymmetric ionization source on both dissipative toroidal drift wave stability and the generation of mean sheared parallel flow are examined. The first part of this work extends the development of a local model of ionization-driven drift wave turbulence [Phys. Fluids B 4, 877 (1992)] to include the effects of magnetic shear and poloidal source asymmetry, as well as poloidal mode coupling due to both magnetic drifts and the source asymmetry. Numerical and analytic investigation confirm that ionization effects can destabilize collisional toroidal drift waves. However, the mode structure is determined primarily by the magnetic drifts, and is not overly effected by the poloidal source asymmetry. The ionization source drives a purely inward particle flux, which can explain the anomalously rapid uptake of particles which occurs in response to gas puffing. In the second part of this work, the role poloidal asymmetries in both the source and turbulent particle diffusion play in the generation of sheared mean parallel flow is examined. Analysis indicates that predictions of sonic parallel shear flow [v parallel (r)∼c s ] are an unphysical result of the assumption of purely parallel flow (i.e., v perpendicular =0) and the neglect of turbulent parallel momentum transport. Results indicate that the flow produced is subcritical to the parallel shear flow instability when diamagnetic effects are properly considered

  12. Comparative Evaluation of Modeling Methods for Harmonic Stability Analysis of Three-Phase Voltage Source Converters

    DEFF Research Database (Denmark)

    Kwon, Jun Bum; Wang, Xiongfei; Bak, Claus Leth

    2015-01-01

    As the increasing of power electronics based systems, not only the component-based analysis but also a systematic interaction analysis with each other systems are being important. Especially studies about the stability and the harmonics interaction are critical in order to establish the required ...... for the AC-DC converters with a low ratio of switching to the fundamental frequency, and it provides an effective way to reveal the harmonic interaction and stability analysis for the future power electronics based power systems.......As the increasing of power electronics based systems, not only the component-based analysis but also a systematic interaction analysis with each other systems are being important. Especially studies about the stability and the harmonics interaction are critical in order to establish the required...... performance in a power network. However, the traditional small-signal modeling approaches are not enough to represent the complexity of the interaction due to the time varying components of such systems. This paper compares the small-signal modeling methods for harmonic analysis of AC - DC converters...

  13. Compact, Wavelength Stabilized Seed Source for Multi-Wavelength Lidar Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I effort proposes to establish the feasibility of developing a compact, high performance laser source for integration into the next generation seed...

  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. Investigation of the dynamics of the Z-pinch imploding plasma for a laser-assisted discharge-produced Sn plasma EUV source

    Science.gov (United States)

    Zhu, Q.; Yamada, J.; Kishi, N.; Watanabe, M.; Okino, A.; Horioka, K.; Hotta, E.

    2011-04-01

    Dynamics of the imploding plasma and its relations to the 13.5 nm EUV emissions have been experimentally investigated for a laser-assisted Sn based discharge-produced plasma EUV source. The behaviours and two-dimensional electron density distributions of the EUV-emitting plasma were obtained using the time-resolved shadowgraph and Nomarski interferometric techniques. Observation of the plasma piston in the prepinch phase justified the validity of the zero-dimensional thin-shell model, from which the ion charge state of the prepinch plasma in the cathode region was estimated. The sausage (m = 0) instability that usually enhances the EUV emission was observed, with the radial electron density distribution that displays a concave shape at the crest of the plasma and a bell shape at the neck; the maximum of the electron density is located at one peak of the concave distribution at the crest instead of the neck. Intense EUV emission was produced by the Z-pinch plasma with the electron density (2.0-3.0) × 1018 cm-3. Moreover, the shock waves generated in the anode region can also produce in-band EUV emission with the intensity of 30% of that from the Z-pinch plasma.

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

    Science.gov (United States)

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

    2017-09-01

    Surface discharge plasma (SDP) combined with activated carbon (AC) was employed to eliminate dissolved organic matter from micro-polluted source water, with humic acid (HA) as the model pollutant. Synergistic effect on HA removal was observed in the SDP-AC system; HA removal efficiency reached 60.9% within 5-min treatment in the SDP-AC system with 5.0 g AC addition, whereas 16.7 and 17.4% of HA were removed in sole SDP system and AC adsorption, respectively. Scanning electron microscope and Boehm titration analysis showed that chemical reactions between active species and functional groups of AC occurred. The existence of isopropanol or benzoquinone exhibited inhibitive effects on HA removal in the SDP system, while these inhibitive effects were weakened in the SDP-AC system. The influences of AC on ozone equivalent concentration and H 2 O 2 concentration were evaluated, and there were approximately 39 and 20% decline in ozone equivalent concentration and H 2 O 2 concentration within 6-min treatment in the SDP-AC system, respectively, compared with those in the sole SDP system. Dissolved organic carbon, specific ultraviolet absorbance, and UV absorption ratios analysis demonstrated that the SDP treatment destroyed the chromophoric groups, double bonds, and aromatic structure of HA molecules, and these destructive actions were strengthened by AC.

  17. Nano-silver in drinking water and drinking water sources: stability and influences on disinfection by-product formation.

    Science.gov (United States)

    Tugulea, A-M; Bérubé, D; Giddings, M; Lemieux, F; Hnatiw, J; Priem, J; Avramescu, M-L

    2014-10-01

    Nano-silver is increasingly used in consumer products from washing machines and refrigerators to devices marketed for the disinfection of drinking water or recreational water. The nano-silver in these products may be released, ending up in surface water bodies which may be used as drinking water sources. Little information is available about the stability of the nano-silver in sources of drinking water, its fate during drinking water disinfection processes, and its interaction with disinfection agents and disinfection by-products (DBPs). This study aims to investigate the stability of nano-silver in drinking water sources and in the finished drinking water when chlorine and chloramines are used for disinfection and to observe changes in the composition of DBPs formed when nano-silver is present in the source water. A dispersion of nano-silver particles (10 nm; PVP-coated) was used to spike untreated Ottawa River water, treated Ottawa River water, organic-free water, and a groundwater at concentrations of 5 mg/L. The diluted dispersions were kept under stirred and non-stirred conditions for up to 9 months and analyzed weekly using UV absorption to assess the stability of the nano-silver particles. In a separate experiment, Ottawa River water containing nano-silver particles (at 0.1 and 1 mg/L concentration, respectively) was disinfected by adding sodium hypochlorite (a chlorinating agent) in sufficient amounts to maintain a free chlorine residual of approximately 0.4 mg/L after 24 h. The disinfected drinking water was then quenched with ascorbic acid and analyzed for 34 neutral DBPs (trihalomethanes, haloacetonitriles, haloacetaldehydes, 1,1 dichloro-2-propanone, 1,1,1 trichloro-2-propanone, chloropicrin, and cyanogen chloride). The results were compared to the profile of DBPs obtained under the same conditions in the absence of nano-silver and in the presence of an equivalent concentration of Ag(+) ions (as AgNO3). The stability of the nano-silver dispersions in

  18. Functional Stability of a Mixed Microbial Consortium Producing PHA From Waste Carbon Sources

    Energy Technology Data Exchange (ETDEWEB)

    David N. Thompson; Erik R. Coats; William A. Smith; Frank J. Loge; Michael P. Wolcott

    2006-04-01

    Polyhydroxyalkanoates (PHAs) represent an environmentally-effective alternative to synthetic thermoplastics; however, current production practices are not sustainable. In this study, PHA production was accomplished in sequencing batch bioreactors utilizing real wastewaters and mixed microbial consortia from municipal activated sludge as inoculum. Polymer production reached 85%, 53%, and 10% of the cell dry weight from methanol-enriched pulp-and-paper mill foul condensate, fermented municipal primary solids, and biodiesel wastewater, respectively. Employing denaturing gradient gel electrophoresis of 16S-rDNA from PCR-amplified DNA extracts, distinctly different communities were observed between and within wastewaters following enrichment. Most importantly, functional stability was maintained despite differing and contrasting microbial populations.

  19. Intensity stability improvements for the intense pulsed neutron source accelerator system

    International Nuclear Information System (INIS)

    Rauchas, A.; Gunderson, G.; Zolecki, R.; Stipp, V.; Volk, G.

    1985-01-01

    The Intense Pulsed Neutron Source (IPNS) accelerator system consists of a 750 keV Cockcroft-Walton preaccelerator, 50 MeV linear accelerator and a 500 MeV Rapid Cycling Synchrotron (RCS). The accelerator system accelerates over 2.5 x 10 12 protons per pulse at a 30 Hz rate to strike a depleted uranium target for producing neutrons (which are used for neutron scattering research.) Since beginning operation in 1977, the beam intensity has been steadily increasing with improvements in various systems, such as a new H - source, improved correction magnet systems, etc. Instabilities created by the higher intensities have also been under control

  20. Mathematical physics approaches to lightning discharge problems

    Science.gov (United States)

    Kyrala, A.

    1985-01-01

    Mathematical physics arguments useful for lightning discharge and generation problems are pursued. A soliton Ansatz for the lightning stroke is treated including a charge generation term which is the ultimate source for the phenomena. Equations are established for a partially ionized plasma inding the effects of pressure, magnetic field, electric field, gravitation, viscosity, and temperature. From these equations is then derived the non-stationary generalized Ohm's Law essential for describing field/current density relationships in the horizon channel of the lightning stroke. The discharge initiation problem is discussed. It is argued that the ionization rate drives both the convective current and electric displacement current to increase exponentially. The statistical distributions of charge in the thundercloud preceding a lightning dischage are considered. The stability of the pre-lightning charge distributions and the use of Boltzmann relaxational equations to determine them are discussed along with a covered impedance path provided by the aircraft.

  1. Single-Source Multi-Battery Solar Charger: Analysis and Stability Issues

    Directory of Open Access Journals (Sweden)

    Alon Kuperman

    2015-06-01

    Full Text Available In this paper, dynamic analysis of a multi-battery dual mode charger, powered by a single solar array and suitable for lead-acid and lithium-ion cell-based batteries is presented. Each battery is interfaced to the solar array by means of a current-controlled buck power stage, operating either in constant power or constant voltage mode. Operation in former/latter charging mode implies regulating input/output voltage of the converter, which is a non-trivial situation since while feeding different batteries, all the converters share the same input terminals, connected to the solar array. It is revealed that when at least one of the batteries operates in constant power charging mode, open-loop instability occurs whenever converter input voltage is lower than maximum power point voltage of the solar array. Consequently, input voltage regulating controller must be designed to stabilize closed-loop dynamics for the worst case of instability, which is also derived. Moreover, it is shown that the dynamics of the converters operating under output voltage control are perceived as disturbances by input voltage control loop and must be properly rejected. Simple loop shaping design is proposed based on a PI controller, allowing stabilizing the system in case of worst case instability and rejecting output voltage control induced disturbances at the expense of non-constant, operating-point dependent closed-loop damping.

  2. Impact of a localized source of subglacial discharge on the heat flux and submarine melting of a tidewater glacier : A laboratory study

    NARCIS (Netherlands)

    Cenedese, Claudia; Gatto, V.M.

    2016-01-01

    Idealized laboratory experiments have been conducted in a two-layer stratified fluid to investigate the leading-order dynamics that control submarine melting and meltwater export near a vertical ice-ocean interface as a function of subglacial discharge. In summer, the discharge of surface runoff

  3. Performance of photon position monitors and stability of undulator beams at the Advanced Light Source

    International Nuclear Information System (INIS)

    Warwick, T.; Andresen, N.; Portmann, G.; Jackson, A.

    1994-01-01

    Position monitors are implemented in three undulator beamlines at the ALS. Their performance has been studied carefully on one of these lines and is reviewed. The monitors work as expected and show the ALS to be an exceptionally stable source of synchrotron radiation

  4. Wind Farm Stabilization by using DFIG with Current Controlled Voltage Source Converters Taking Grid Codes into Consideration

    Science.gov (United States)

    Okedu, Kenneth Eloghene; Muyeen, S. M.; Takahashi, Rion; Tamura, Junji

    Recent wind farm grid codes require wind generators to ride through voltage sags, which means that normal power production should be re-initiated once the nominal grid voltage is recovered. However, fixed speed wind turbine generator system using induction generator (IG) has the stability problem similar to the step-out phenomenon of a synchronous generator. On the other hand, doubly fed induction generator (DFIG) can control its real and reactive powers independently while being operated in variable speed mode. This paper proposes a new control strategy using DFIGs for stabilizing a wind farm composed of DFIGs and IGs, without incorporating additional FACTS devices. A new current controlled voltage source converter (CC-VSC) scheme is proposed to control the converters of DFIG and the performance is verified by comparing the results with those of voltage controlled voltage source converter (VC-VSC) scheme. Another salient feature of this study is to reduce the number of proportionate integral (PI) controllers used in the rotor side converter without degrading dynamic and transient performances. Moreover, DC-link protection scheme during grid fault can be omitted in the proposed scheme which reduces overall cost of the system. Extensive simulation analyses by using PSCAD/EMTDC are carried out to clarify the effectiveness of the proposed CC-VSC based control scheme of DFIGs.

  5. 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).

  6. Characterization of polarized electrons coming from helium post-discharge source; Caracterisation du faisceau d`electrons polarises issus d`une source a post-decharge d`helium

    Energy Technology Data Exchange (ETDEWEB)

    Zerhouni, R.O.

    1996-02-01

    The objective of this thesis is the characterization of the polarized electron source developed at Orsay and foreseen to be coupled to a cw accelerator for nuclear physics experiments. The principle of operation of this source relies on the chemo-ionization reaction between optically aligned helium triplet metastable atoms and CO{sub 2} molecules. The helium metastable atoms are generated by injection of purified helium into a 2,45 GHz micro-wave discharge. They are optically pumped using two beams of 1,083 micro-meter resonant radiation, one circularly and the other linearly polarized. Both beams are delivered by a high power LNA laser. The metastable atomic beam interacts with a dense (10{sup 13} cm {sup -3}) spin singlet CO{sub 2} target. A fraction of the produced polarized electrons is extracted and collimated by electrostatic optics. Either to the Mott polarimeter or to the Faraday cup in order to measure the electron polarization and extracted current. For current intensities of 100 micro-Amperes, the electronic polarization reaches 62 % and shows that this type of source has reached the same high competitive level as the most performing GaAs ones. Additionally, the optical properties of the extracted beam are found to be excellent. These properties (energy spread and emittance) reflect the electron energy distribution at the chemo-ionization region. The upper limit of the beam`s energy spread is 0.24 eV since this value characterizes our instrumental resolution. The average normalized emittance is found to be 0.6 pi mm-mrad. These values satisfy the requirements of most cw accelerators. All the measurements were performed at low electron beam transport energies (1 to 2 KeV). (author). 105 refs., 54 figs., 4 tabs.

  7. Coexisting sea-based and land-based sources of contamination by PAHs in the continental shelf sediments of Coatzacoalcos River discharge area (Gulf of Mexico).

    Science.gov (United States)

    Ruiz-Fernández, Ana Carolina; Portela, Julián Mauricio Betancourt; Sericano, José Luis; Sanchez-Cabeza, Joan-Albert; Espinosa, Luisa Fernanda; Cardoso-Mohedano, José Gilberto; Pérez-Bernal, Libia Hascibe; Tinoco, Jesús Antonio Garay

    2016-02-01

    The oldest refinery and the major petrochemical complexes of Mexico are located in the lower reach of the Coatzacoalcos River, considered the most polluted coastal area of Mexico. A (210)Pb-dated sediment core, from the continental shelf of the Coatzacoalcos River, was studied to assess the contamination impact by the oil industry in the southern Gulf of Mexico. The sedimentary record showed the prevalence of petrogenic PAHs between 1950s and 1970s, a period during which waste discharges from the oil industry were not regulated. Later on, sediments exhibited higher contents of pyrogenic PAHs, attributed to the incineration of petrochemical industry wastes and recurrent wildfires in open dumpsites at the nearby swamps. The total concentration of the 16 EPA-priority PAHs indicated low levels of contamination (1000 ng g(-1)) during the late 1970s, most likely due to the major oil spill produced by the blowout of the Ixtoc-I offshore oil rig in deep waters of the southwestern Gulf of Mexico. Most of the PAH congeners did not show defined temporal trends but, according to a Factor Analysis, apparently have a common origin, probably waste released from the nearby oil industry. The only exceptions were the pyrogenic benzo(b)fluoranthene and benzo(a)pyrene, and the biogenic perylene, that showed increasing concentration trends with time, which we attributed to erosional input of contaminated soil from the catchment area. Our study confirmed chronic oil contamination in the Coatzacoalcos River coastal area from land based sources for more than 60 years (since 1950s). Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Efficiency and stability of a phosphor-conversion white light source using a blue laser diode

    Directory of Open Access Journals (Sweden)

    G. Ledru

    2014-10-01

    Full Text Available A white light source using direct phosphor-conversion excited by a blue laser diode is presented. In this preliminary study we have investigated the influence of phosphor’s thickness and operating current of the laser diode over the (x, y chromaticity coordinates, Correlated Color Temperature (CCT and Color Rendering Index (CRI. The best values found were 4000 K and 94. A 40 lm/W luminous efficacy was achieved together with a CRI close to 90 for an operating current of 0.8 A. Those values, to the best of our knowledge, were not previously reported in the literature.

  9. Circular arc fuel plate stability experiments and analyses for the advanced neutron source

    International Nuclear Information System (INIS)

    Swinson, W.F.; Battiste, R.L.; Yahr, G.T.

    1995-08-01

    The thin fuel plates planned for the Advanced Neutron Source are to be cooled by forcing heavy water at high velocity, 25 m/s, through thin cooling channels on each side of each plate. Because the potential for structural failure of the plates is a design concern, considerable effort has been expended in assessing this potential. As part of this effort, experimental flow tests and analyses to evaluate the structural response of circular arc plates have been conducted, and the results are given in this report

  10. Carotenoids: Actual knowledge on food sources, intakes, stability and bioavailability and their protective role in humans

    DEFF Research Database (Denmark)

    Maiani, Giuseppe; Castón, María Jesús Periago; Catasta, Giovina

    2009-01-01

    Carotenoids are one of the major food micronutrients in human diets and the overall objective of this review is to re-examine the role of carotenoids in human nutrition. We have emphasized the attention on the following carotenoids present in food and human tissues: -carotene, -cryptoxanthin......, -carotene, lycopene, lutein and zeaxanthin; we have reported the major food sources and dietary intake of these compounds. We have tried to summarize positive and negative effects of food processing, storage, cooking on carotenoid content and carotenoid bioavailability. In particular, we have evidenced...... the possibility to improve carotenoids bioavailability in accordance with changes and variations of technology procedures....

  11. Stability and emulsifying capacity of biosurfactants obtained from lignocellulosic sources using Lactobacillus pentosus.

    Science.gov (United States)

    Portilla-Rivera, O; Torrado, A; Domínguez, J M; Moldes, A B

    2008-09-10

    Lactobacillus pentosus grown on sugars from agricultural residues produces biosurfactants with emulsifying properties that could facilitate the bioremediation of hydrocarbon contaminated sites. The biosurfactans obtained after growing L. pentosus cells on distilled grape marc hydrolyzates gave values of relative emulsion volume (EV) close to 50%, being stable after 72 h when gasoline or kerosene were employed. These EV values were higher than those achieved using commercial surfactin (14.1% for gasoline and 27.2% for kerosene). Moreover, assays carried out with kerosene showed that L. pentosus produced biosurfactants from distilled grape marc hydrolyzates with the highest stabilizing capacity value (ES) to maintain the emulsion (99%) followed by biosurfactants produced from hazelnut shell hydrolyzates (97%). These data are comparable with those obtained using sodium dodecyl sulfate, SDS (87.7%), whereas surfactin only gave an ES value of 65.4%. Consequently, this work shows that utilization of low-cost feedstock agricultural residues as substrates for producing biosurfactants/bioemulsifiers is possible thus removing obstacles for the wide-scale industrial application of biosurfactants/bioemulsifiers.

  12. Functional Stability Of A Mixed Microbial Consortia Producing PHA From Waste Carbon Sources

    Energy Technology Data Exchange (ETDEWEB)

    David N. Thompson; Erik R. Coats; William A. Smith; Frank J. Loge; Michael P. Wolcott

    2006-04-01

    Polyhydroxyalkanoates (PHAs), naturally-occurring biological polyesters that are microbially synthesized from a myriad of carbon sources, can be utilized as biodegradable substitutes for petroleum-derived thermoplastics. However, current PHA commercialization schemes are limited by high feedstock costs, the requirement for aseptic reactors, and high separation and purification costs. Bacteria indigenous to municipal waste streams can accumulate large quantities of PHA under environmentally controlled conditions; hence, a potentially more environmentally-effective method of production would utilize these consortia to produce PHAs from inexpensive waste carbon sources. In this study, PHA production was accomplished in sequencing batch bioreactors utilizing mixed microbial consortia from municipal activated sludge as inoculum, in cultures grown on real wastewaters. PHA production averaged 85%, 53%, and 10% of the cell dry weight from methanol-enriched pulp-and-paper mill foul condensate, fermented municipal primary solids, and biodiesel wastewater, respectively. The PHA-producing microbial consortia were examined to explore the microbial community changes that occurred during reactor operations, employing denaturing gradient gel electrophoresis (DGGE) of 16S-rDNA from PCR-amplified DNA extracts. Distinctly different communities were observed both between and within wastewaters following enrichment. More importantly, stable functions were maintained despite the differing and contrasting microbial populations.

  13. Esophagectomy - discharge

    Science.gov (United States)

    ... 000241.htm Esophagectomy - discharge To use the sharing features on this page, please enable JavaScript. You had ... up or down stairs, or ride in a car. Be sure to rest after being active. If it hurts when ... In the bathroom , install safety bars to help you get in and out ...

  14. Mastectomy - discharge

    Science.gov (United States)

    ... had breast reconstruction surgery with implants or natural tissue . What to Expect at Home Full recovery may take ... lump removal Breast reconstruction - implants Breast reconstruction - natural ... breast surgery - discharge Mastectomy and breast reconstruction - what to ask your doctor Wet-to-dry dressing ...

  15. Status report on the long-term stability of the Advanced Photon Source

    International Nuclear Information System (INIS)

    Friedsam, H.

    1998-01-01

    Table 1 summarizes the average elevation changes and standard deviations as well as the points with the largest changes for each year. On average, hardly any settlements can be detected; however, local changes of +2.90 mm to -2.31 mm have been measured. Looking at the low and high points, the settlement process is slowing down over time. Overall, the settlements observed match the expectations for this type of construction. To date no major realignment of the Advanced Photon Source (APS) storage ring has been necessary. The particle beam tracks with the settlements of the floor as long as these changes occur in a smooth fashion and not as sudden discontinuities [5]. From Figures 6 through 8 it is also apparent that settlements affect larger areas in the storage ring and experiment hall that impact the location of the source point as well as the location of the beamline user equipment. The limiting apertures of the insertion device chambers will make realignment of the APS storage ring a necessity at some point in the future. Currently simulations and machine studies we underway to provide an estimate of tolerable settlement limits before a realignment of certain sections of the storage ring would be required. In conclusion, the APS has been constructed on solid ground with an excellent foundation. Only small settlement changes are being observed; so far they are not impacting the operation of the accelerator. We are continuing to monitor deformations of the APS floor in anticipation of a future realignment of the accelerator components

  16. Biomarker and carbon isotope constraints (δ13C, Δ14C) on sources and cycling of particulate organic matter discharged by large Siberian rivers draining permafrost areas

    International Nuclear Information System (INIS)

    Winterfeld, Maria

    2014-08-01

    Circumpolar permafrost soils store about half of the global soil organic carbon pool. These huge amounts of organic matter (OM) could accumulate due to low temperatures and water saturated soil conditions over the course of millennia. Currently most of this OM remains frozen and therefore does not take part in the active carbon cycle, making permafrost soils a globally important carbon sink. Over the last decades mean annual air temperatures in the Arctic increased stronger than the global mean and this trend is projected to continue. As a result the permafrost carbon pool is under climate pressure possibly creating a positive climate feedback due to the thaw-induced release of greenhouse gases to the atmosphere. Arctic warming will lead to increased annual permafrost thaw depths and Arctic river runoff likely resulting in enhanced mobilization and export of old, previously frozen soil-derived OM. Consequently, the great arctic rivers play an important role in global biogeochemical cycles by connecting the large permafrost carbon pool of their hinterlands with the arctic shelf seas and the Arctic Ocean. The first part of this thesis deals with particulate organic matter (POM) from the Lena Delta and adjacent Buor Khaya Bay. The Lena River in central Siberia is one of the major pathways translocating terrestrial OM from its southernmost reaches near Lake Baikal to the coastal zone of the Laptev Sea. The permafrost soils from the Lena catchment area store huge amounts of pre-aged OM, which is expected to be remobilized due to climate warming. To characterize the composition and vegetation sources of OM discharged by the Lena River, the lignin phenol and carbon isotopic composition (δ 13 C and Δ 14 C) in total suspended matter (TSM) from surface waters, surface sediments from the Buor Khaya Bay along with soils from the Lena Delta's first (Holocene) and third terraces (Pleistocene ice complex) were analyzed. The lignin compositions of these samples are

  17. LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Conditions for the simultaneous formation of Ar, Kr, and Xe chlorides in a multiwave radiation source pumped by a transverse discharge

    Science.gov (United States)

    Shuaibov, Aleksandr K.; Dashchenko, Arkadii I.

    2000-03-01

    Conditions for the formation of ArCl(B), KrCl(B), XeCl(D, B), and Cl2(D') molecules in a pulsed transverse discharge based on an Ar—Kr—Xe—Cl2 mixture (p=2-30 kPa) were investigated. It is shown that the discharge is a multiwave source of VUV—UV radiation at λ =175, 222, 236, 258, and 308 nm in ArCl (B—X transition), KrCl (B—X), XeCl (D—X), Cl2 (D'—A'), and XeCl (B—X), respectively. In order to obtain comparable brightness of the radiation as a result of the above transitions of the molecules at a moderate charging voltage (4-15 kV), the partial pressure of the Kr and Xe atoms in the mixture must be in the range 0.2-0.5 kPa. The discharge investigated is of interest for developing a multiwave electric-discharge-pumped radiation source based on chlorides of heavy rare gases emitting in the range 175-308 nm.

  18. Stability of high-speed lithium sheet jets for the neutron source in Boron Neutron Capture Therapy (BNCT)

    International Nuclear Information System (INIS)

    Nakagawa, Masamichi; Takahashi, Minoru; Aritomi, Masanori; Kobayashi, Toru

    2014-01-01

    The stability of high-speed liquid lithium sheet jets was analytically studied for the neutron source in Boron Neutron Capture Therapy (BNCT), which makes cancers and tumors curable with cell-level selections and hence high QOL. The object of our research is to realize the thin and high-speed plane sheet jets of liquid lithium in a high-vacuum as an accelerator target. Linear analysis approach is made to the stability on thin plane sheet jets of liquid lithium in a high-vacuum, and then our analytical results were compared with the previous experimental ones. We proved that the waves of surface tension on thin lithium sheet jets in a high-vacuum are of supercritical flows and neutral stable under about 17.4 m/s in flow velocity and that the fast non-dispersive anti-symmetric waves are more significant than the very slow dispersive symmetric waves. We also formulated the equation of shrinking angle in isosceles-triangularly or isosceles-trapezoidal shrinking sheet jets corresponding to the Mach angle of supersonic gas flows. This formula states universally the physical meaning of Weber number of sheet jets on the wave of surface tension in supercritical flows. We obtained satisfactory prospects (making choice of larger flow velocity U and larger thickness of sheet a) to materialize a liquid target of accelerator in BNCT. (author)

  19. Trace Mineral Sources and Rosemary Oil in the Diet of Brown Laying Hens: Egg Quality and Lipid Stability

    Directory of Open Access Journals (Sweden)

    NR Batista

    Full Text Available ABSTRACT Two experiments were carried out to evaluate the effects of rosemary oil (RO and trace mineral sources (MS on the internal quality and lipid stability of brown layer eggs. The treatments consisted of diets supplemented with two trace mineral sources (inorganic or organic and three levels (0, 100, or 200 mg kg-1 of rosemary oil (RO, and three egg storage times. Eggs were stored at a controlled temperature (CT; 25.0ºC in Experiment I and under refrigeration (RT; 5.0ºC in Experiment II. The following parameters were analyzed on days 0 (fresh, 15 and 30 of storage: malonaldehyde level (MDA, egg weight (EW, Haugh unit (HU, yolk index (YI, albumen and yolk pH, raw yolk color (RYC, and egg weight loss. Data were analyzed according to completely randomized design in a 2x3x3 factorial arrangement (MS x RO x storage time. In Experiment I, there was an interaction between treatments for EW, HU and ALBp. Dietary OTM inclusion improved the results for all analyzed variables. The addition of 200 mg kg-1 RO reduced MDA and increased HU, YI and RYC. In experiment II, 200 mg kg-1 of RO in the diet improved HU. The internal quality of eggs stored both at CT and under RT is adversely affected by increasing storage periods, but this effect can be minimized by the dietary supplementation of OTM and 200 mg kg-1 rosemary oil. The lipid stability of eggs stored at CT improves with the supplementation of OTM and 200 mg kg-1 rosemary oil, but not of eggs stored under refrigeration.

  20. Thermal stabilities and optimal operating parameters for the Oak Ridge Spallation Neutron Source superconducting linear accelerator

    International Nuclear Information System (INIS)

    Kim, Sang-Ho; Campisi, Isidoro E.

    2007-01-01

    The baseline Spallation Neutron Source (SNS) accelerator will provide a 1 GeV, 1.4 MW proton beam to a mercury target for the production of neutrons. The main acceleration for the H- beam is provided by 81 superconducting cavities installed in 23 cryomodules operating at 805 MHz. The design of the superconducting linac includes a 2.1 K, 2.5 kW cryogenic plant to maintain the cavities below the helium lambda point for efficient operation at high accelerating gradients. In this paper operating conditions are analyzed rather than the design ones, which still guarantees a high gradient operation without any temperature constraint. From the analysis it appears that the SNS superconducting linac can be operated at temperatures higher than 2.1 K, a fact resulting from both the pulsed nature of the superconducting cavities, the specific configuration of the existing cryogenic plant and the operating frequency. General conditions are also given regarding the operation of pulsed superconducting cavities resonating at different frequencies

  1. Remote Operating Monitoring Of Spatial Stability Magnets On A Kurchatov Source Of Synchrotron Radiation

    CERN Document Server

    Barkovsky, E V; Martynenko, V V; Novikov, V A; Udin, L I

    2004-01-01

    During operation of the accelerator because of a nonuniform warm -up of the ring base and constructions of installation there are angular and linear displacements of bending and focusing magnets of a Big Accelerator Ring (BR) of a Kurchatov Source of Synchrotron Radiation. With the purpose of remote operating monitoring of a spatial position of elements BR was used anglemetrical control and measuring system with digital and analog registration in a real time mode. The results of the first stage of a monitoring BR have shown high informativity of the given instrumental - methodical means. The basic radiants of cyclical thermoelastic alternating strains are detected; the amplitudes of angular and linear displacements of magnets from different internal factors evaluated during operation of the accelerator. Is established, that the maximum radial angular and linear displacements of magnets are watched in 3,5-4 day after switching on of installation and achieve in max 30-35 seconds of an arc or 120-150 microns in ...

  2. 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)

  3. Study of the use of an electric discharge for hollow cathodes used as optical excitation sources in the spectrographic measurement of fluorine in thorium, uranium and plutonium

    International Nuclear Information System (INIS)

    Bufpereau, M.; Crehange, G.; Poublan, J.

    1964-01-01

    Previous works and phenomena concerned with a hollow cathode excitation are reviewed. Experiments aimed specially on the determination of the best conditions for an analysis of fluorine in oxides-metals and solutions. In that purpose, several factors have been pointed out. One started some researches about others elements that fluorine. Carrying fluorine into discharge and excitation have been more specially studied. A quantitative analysis method is given. The analysis limit is 45 ppm about but the detection limit is 5 ppm about. As a conclusion, various ways for optical excitation of fluorine are reviewed as other analytical possibilities a hollow cathode discharge offers. (authors) [fr

  4. Neutral gas temperature maps of the pin-to-plate argon micro discharge into the ambient air

    International Nuclear Information System (INIS)

    Xu, S. F.; Zhong, X. X.; Majeed, Asif

    2015-01-01

    This study is designed to explore the two dimensional temperature maps of the atmospheric argon discharge consisting of pin-to-plane electrodes supplied by a high voltage DC source. After checking the stability of the micro discharge, the two dimensional image plane focused by a quartz lens was scanned by the fiber probe driven by a 3D Mobile Platform. The rotational and vibrational temperatures are calculated using nitrogen emissions collected by the high resolution spectrometer and high sensitive intensified charge coupled device. The rotational temperature varies from 1558.15 K to 2621.14 K and vibrational temperature varies from 3010.38 K to 3774.69 K, indicating a great temperature gradient due to small discharge size. The temperature maps show a lateral expansion and a sharp truncation in the radial direction. A double layers discharge is identified, where an arc discharge coats the glow discharge

  5. Discharge Dialogue

    DEFF Research Database (Denmark)

    Horsbøl, Anders

    2012-01-01

    less attention has been given to medical patients, who are often elderly and suffer from multiple diseases. This paper addresses the latter issue with a case study of a local initiative to improve transition from hospital to home (care) for medical patients at a Danish hospital, in which a discharge......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...

  6. Influence of geometry of the discharge interval on distribution of ion and electron streams at surface of the Penning source cathode

    International Nuclear Information System (INIS)

    Egiazaryan, G.A.; Khachatrian, Zh.B.; Badalyan, E.S.; Ter-Gevorgyan, E.I.; Hovhannisyan, V.N.

    2006-01-01

    In the discharge of oscillating electrons, the mechanism of the processes, which controls the distribution of the ion and electron streams over the cathode surface, is investigated experimentally. The influence of the length of the discharge interval on value and distribution of the ion and electron streams is analyzed. The distribution both of ion and electron streams at the cathode surface is determined at different conditions of the discharge. It is shown that for given values of the anode diameter d a =31 mm and the gas pressure P=5x10 -5 Torr, the intensive stream of positive ions falls entirely on the cathode central area in the whole interval of the anode length variation (l a =1-11 cm). At the cathode, the ion current reaches the maximal value at a certain (optimal) value of the anode length that, in turn, depends on the anode voltage U a . The intensive stream of longitudinal electrons forms in the short anodes only (l a =2.5-3.5 cm) and depending on the choice of the discharge regime, may fall both on central and middle parts of the cathode

  7. Sources

    International Nuclear Information System (INIS)

    Duffy, L.P.

    1991-01-01

    This paper discusses the sources of radiation in the narrow perspective of radioactivity and the even narrow perspective of those sources that concern environmental management and restoration activities at DOE facilities, as well as a few related sources. Sources of irritation, Sources of inflammatory jingoism, and Sources of information. First, the sources of irritation fall into three categories: No reliable scientific ombudsman to speak without bias and prejudice for the public good, Technical jargon with unclear definitions exists within the radioactive nomenclature, and Scientific community keeps a low-profile with regard to public information. The next area of personal concern are the sources of inflammation. This include such things as: Plutonium being described as the most dangerous substance known to man, The amount of plutonium required to make a bomb, Talk of transuranic waste containing plutonium and its health affects, TMI-2 and Chernobyl being described as Siamese twins, Inadequate information on low-level disposal sites and current regulatory requirements under 10 CFR 61, Enhanced engineered waste disposal not being presented to the public accurately. Numerous sources of disinformation regarding low level radiation high-level radiation, Elusive nature of the scientific community, The Federal and State Health Agencies resources to address comparative risk, and Regulatory agencies speaking out without the support of the scientific community

  8. Effect of different calcium sources on the bioactive compounds stability of extruded and nixtamalized blue maize flours.

    Science.gov (United States)

    Sánchez-Madrigal, Miguel Ángel; Quintero-Ramos, Armando; Martínez-Bustos, Fernando; Meléndez-Pizarro, Carmen O; Ruiz-Gutiérrez, Martha G; Camacho-Dávila, Alejandro; Torres-Chávez, Patricia Isabel; Ramírez-Wong, Benjamín

    2015-05-01

    The stability of antioxidants in extruded and nixtamalized blue maize flours with calcium hydroxide [Ca(OH)2] and calcium lactate [C6H10O6Ca] were evaluated. Extruded blue maize flours batches were obtained by mixing blue maize flours separately with different Ca(OH)2 (0.1, 0.2 and 0.3 %) and C6H10O6Ca (0.3, 0.6 and 0.9 %) concentrations respectively and extruded to obtain the extruded flours. For nixtamalized flours, the maize grains were cooked at 1 % Ca(OH)2 and 2.95 % C6H10O6Ca concentrations respectively. Color, antioxidant activity, total phenolics, total anthocyanins and individual anthocyanins, contents were analyzed. Color, antioxidant activity, anthocyanins contents and total phenolics decreased as the calcium hydroxide concentration increased. In contrast, increasing the calcium lactate concentration on the extruded flours had the opposite effect. The extrusion process retained 57-47 %, 72-62 % and 79-65 % of the anthocyanins content, total phenolic content and antioxidant activity, respectively. These retention rates were higher than those of the nixtamalized flours using the same calcium sources. Cyanidin-3-glucoside and pelargonidin-3-glucoside were identified in the maize kernel and flours. Cyanidin-3-glucoside concentration was increased by both extrusion and nixtamalization processed with either of the two calcium sources. In contrast, pelargonidin-3-glucoside concentration decreased by both processes. Other anthocyanins were observed, but they were not identified.

  9. Lung surgery - discharge

    Science.gov (United States)

    ... Lung biopsy - discharge; Thoracoscopy - discharge; Video-assisted thoracoscopic surgery - discharge; VATS - discharge ... milk) for 2 weeks after video-assisted thoracoscopic surgery and 6 to 8 weeks after open surgery. ...

  10. Hysterectomy - vaginal - discharge

    Science.gov (United States)

    Vaginal hysterectomy - discharge; Laparoscopically assisted vaginal hysterectomy - discharge; LAVH - discharge ... you are unable to urinate. You have a discharge from your vagina that has a bad odor. You have bleeding ...

  11. Pediatric heart surgery - discharge

    Science.gov (United States)

    ... discharge; Heart valve surgery - children - discharge; Heart surgery - pediatric - discharge; Heart transplant - pediatric - discharge ... Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 434. ...

  12. Hip replacement - discharge

    Science.gov (United States)

    ... discharge; Total hip replacement - discharge; Hip hemiarthroplasty - discharge; Osteoarthritis - hip replacement discharge ... such as downhill skiing or contact sports like football and soccer. But you should be able to ...

  13. Time effects on the stability of the induced defects in TiO2 nanoparticles doped by different nitrogen sources

    Science.gov (United States)

    Spadavecchia, F.; Ardizzone, S.; Cappelletti, G.; Oliva, C.; Cappelli, S.

    2012-12-01

    N-doped TiO2 samples are claimed to be the most promising among the so-called second-generation photocatalysts, but their success in photocatalysis is still under debate. In this study, N-doped TiO2 nanocrystals are obtained by a simple, quick, and effortless procedure, starting from titanium alkoxide as the precursor for the sol-gel route, with the N source being either inorganic (NH3) or organic (triethylamine, urea). Structural, morphological, and optical characterizations are compared with electron paramagnetic resonance (EPR) data to give an integrated picture of such materials. No literature data on the "aging" features in the dry state of the fresh calcined samples on the EPR and diffuse reflectance spectra (DRS) measurements are reported. Our N-doped TiO2 powders show different stabilities of paramagnetic and optical signals. The photocatalytic activity is tested, toward the degradation of ethanol in aqueous media, under both visible and UV irradiation, in this latter case resembling the same trend of the paramagnetic species decay.

  14. Coplanar surface barrier discharge ignited in water vapor—a selective source of OH radicals proved by (TA)LIF measurement

    Science.gov (United States)

    Procházka, V.; Tučeková, Z.; Dvořák, P.; Kováčik, D.; Slavíček, P.; Zahoranová, A.; Voráč, J.

    2018-01-01

    Coplanar dielectric barrier discharge (DBD) was ignited in pure water vapor at atmospheric pressure in order to generate highly oxidizing plasma with one specific type of reactive radicals. In order to prevent water condensation the used plasma reactor was heated to 120 {}\\circ C. The composition of the radical species in the discharge was studied by methods based on laser-induced fluorescence (LIF) and compared with analogous measurements realized in the same coplanar DBD ignited in air. Fast collisional processes and laser-surface interaction were taken into account during LIF data processing. It was found that coplanar DBD ignited in water vapor produces hydroxyl (OH) radicals with concentration in the order of 1020 m-3, which is 10× higher than the value measured in discharge in humid air (40% relative humidity at 21 {}\\circ C). The concentration of atomic hydrogen radicals in the DBD ignited in water vapor was below the detection limit, which proves that the generation of oxidizing plasma with dominance of one specific type of reactive radicals was achieved. The temporal evolution, spatial distribution, power dependence and rotational temperature of the OH radicals was determined in the DBD ignited in both water vapor and air.

  15. Is groundwater discharge the dominant source of nutrients to Alabama estuaries and will it keep impacting these waters for the foreseeable future?

    Science.gov (United States)

    Mortazavi, B.; Domangue, R.; Kleinhuizen, A.; Tatariw, C.

    2017-12-01

    Land use change and population growth are dominant factors impacting coastal waters. Populations in Alabama coastal counties have increased by several folds since the 1950s and a large fraction of the farmed land are now being used for growing sod requiring large amounts of fertilizers. Concurrent with these changes, marshes bordering Mobile Bay have been disappearing such that they now only cover 50% of their areal extent compared to the 1780s. These changes in land use and coastal geomorphology, as well as the population growth ultimately result in larger delivery of nutrients either through runoff or groundwater discharge to the coastal waters. The Mobile Bay estuary in Alabama is bordered with several subestuaries and a coastal lagoon. Our investigations suggest that the large inputs of nutrients through river discharge in Weeks Bay (140 g N m-2 yr-1) and groundwater discharge in Little Lagoon (300 g N m-2 yr-1) by far dominate inputs of N to the water column and exceed N input, for example, from benthic regeneration, by an order of magnitude. Furthermore, the capacity for N removal through denitrification in these systems is low and instead nitrogen is retained through dissimilatory nitrate reduction to ammonium at a rate that exceed denitrification by an order of magnitude. Our measurements also suggest that once marshes are transformed to subtidal unvegetated sediments rates of nitrogen removal by denitrification decline four folds. Excessive inputs of nitrogen and the high efficiency with which nitrogen is retained in these systems is impacting the foodweb and harmful algal blooms and fish kills are reoccurring events. While changes in agricultural practices and reconstruction of marshes can potentially reduce the delivery of N or enhance N removal by denitrification, nutrient inputs through groundwater discharge are going to impact these estuaries for the foreseeable future. Our capacity to construct nutrient budgets and to predict the trajectory of

  16. Discharge processes of UV pre-ionized electric-discharge pulsed DF laser

    Science.gov (United States)

    Pan, Qikun; Xie, Jijiang; Shao, Chunlei; Wang, Chunrui; Shao, Mingzhen; Guo, Jin

    2016-03-01

    The discharge processes of ultraviolet (UV) pre-ionized electric-discharge pulsed DF laser operating with a SF6-D2 gas mixture are studied. A mathematical model based on continuity equation of electrons and Kirchhoff equations for discharge circuit is established to describe the discharge processes. Voltage and current waveforms of main discharge and voltage waveforms of pre-ionization are solved numerically utilizing the model. The calculations correctly display some physical processes, such as the delay time between pre-ionization and main discharge, breakdown of the main electrode and self-sustained volume discharge (SSVD). The results of theory are consistent with the experiments, which are performed in our non-chain pulsed DF laser. Then the delay inductance and peak capacitance are researched to analyze their influences on discharge processes, and the circuit parameters of DF laser are given which is useful to improve the discharge stability.

  17. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  18. The effect of metal-buffer bilayer drain/source electrodes on the operational stability of the organic field effect transistors

    International Nuclear Information System (INIS)

    Karimi-Alavijeh, H.R.; Ehsani, A.

    2015-01-01

    In this paper, we have investigated experimentally the effect of different drain/source (D/S) electrodes and charge injection buffer layers on the electrical properties and operational stability of a stilbene organic field effect transistor (OFET). The results show that the organic buffer layer of copper phthalocyanine (CuPc) considerably improves the electrical properties of the transistors, but has a negligible effect on their temporal behavior. On the other hand, inorganic metal-oxide buffer layer of molybdenum oxide (MoO 3 ) drastically changes both the electrical properties and operational stability. The functionalities of this metal-oxide tightly depend on the properties of the D/S metallic electrodes. OFETs with Al/MoO 3 as the bilayer D/S electrodes have the best electrical properties: field effect mobility μ eff = 0.32 cm 2 V −1 s −1 and threshold voltage V TH = − 5 V and the transistors with Ag/MoO 3 have the longest operational stability. It was concluded that the chemical stability of the metal/metal-oxide or metal/organic interfaces of the bilayer D/S electrodes determine the operational stability of the OFETs. - Highlights: • The effect of buffer layers on the performance of the stilbene OFETs has been investigated. • Inorganic buffer layer improved the electrical and temporal behaviors simultaneously. • Organic buffer layer only changes the electrical properties. • Chemical stability of the interfaces determines the operational stability of the transistor

  19. Automatic control system for the pig ion source for the U-400 cyclotron

    International Nuclear Information System (INIS)

    Kutner, V.B.; Subbotin, V.G.; Sukhov, A.M.; Tret'yakov, Yu.P.; Fefilov, B.V.

    1989-01-01

    An automatic control system is described for the cyclotron U-400 multiply-charged ion source based on CAMAC apparatus and microprocesor controllers. The system allows the automatic tuning of the ion source to the necessary regime including the automatic start-up of discharge, the obtaining of the necessary parameters of sputtering, the automatic search for a maximum beam current within the given discharge parameters. The system performs tuning the ion source to the quasioptimal regime for 10-15 minutes with up to 5% deviation from the preset parameters. It is possible to stabilize the beam current within 3% using the automatic correction of the discharge regime. 6 refs.; 4 figs

  20. Groundwater discharge by evapotranspiration, flow of water in unsaturated soil, and stable isotope water sourcing in areas of sparse vegetation, Amargosa Desert, Nye County, Nevada

    Science.gov (United States)

    Moreo, Michael T.; Andraski, Brian J.; Garcia, C. Amanda

    2017-08-29

    This report documents methodology and results of a study to evaluate groundwater discharge by evapotranspiration (GWET) in sparsely vegetated areas of Amargosa Desert and improve understanding of hydrologic-continuum processes controlling groundwater discharge. Evapotranspiration and GWET rates were computed and characterized at three sites over 2 years using a combination of micrometeorological, unsaturated zone, and stable-isotope measurements. One site (Amargosa Flat Shallow [AFS]) was in a sparse and isolated area of saltgrass (Distichlis spicata) where the depth to groundwater was 3.8 meters (m). The second site (Amargosa Flat Deep [AFD]) was in a sparse cover of predominantly shadscale (Atriplex confertifolia) where the depth to groundwater was 5.3 m. The third site (Amargosa Desert Research Site [ADRS]), selected as a control site where GWET is assumed to be zero, was located in sparse vegetation dominated by creosote bush (Larrea tridentata) where the depth to groundwater was 110 m.Results indicated that capillary rise brought groundwater to within 0.9 m (at AFS) and 3 m (at AFD) of land surface, and that GWET rates were largely controlled by the slow but relatively persistent upward flow of water through the unsaturated zone in response to atmospheric-evaporative demands. Greater GWET at AFS (50 ± 20 millimeters per year [mm/yr]) than at AFD (16 ± 15 mm/yr) corresponded with its shallower depth to the capillary fringe and constantly higher soil-water content. The stable-isotope dataset for hydrogen (δ2H) and oxygen (δ18O) illustrated a broad range of plant-water-uptake scenarios. The AFS saltgrass and AFD shadscale responded to changing environmental conditions and their opportunistic water use included the time- and depth-variable uptake of unsaturated-zone water derived from a combination of groundwater and precipitation. These results can be used to estimate GWET in other areas of Amargosa Desert where hydrologic conditions are similar.

  1. Ultraviolet radiation induced discharge laser

    Science.gov (United States)

    Gilson, Verle A.; Schriever, Richard L.; Shearer, James W.

    1978-01-01

    An ultraviolet radiation source associated with a suitable cathode-anode electrode structure, disposed in a gas-filled cavity of a high pressure pulsed laser, such as a transverse electric atmosphere (TEA) laser, to achieve free electron production in the gas by photoelectric interaction between ultraviolet radiation and the cathode prior to the gas-exciting cathode-to-anode electrical discharge, thereby providing volume ionization of the gas. The ultraviolet radiation is produced by a light source or by a spark discharge.

  2. Effects of electric discharges on polymers

    International Nuclear Information System (INIS)

    Bagirov, M.A.

    2002-01-01

    Full text: One of the reasons for the worsening of electrical properties of polymeric isolation in use in the effect of the electric discharges which developing in the gas inclusions and in the interlayer inside the isolation itself. The electrical discharges in the gas gap lead to the electrical growing old and the worsening of its electro physical qualities. We have learned the changes of electrical properties (dielectrical permeability and dielectrical loss, and electrical conductivity, electrical strength) of polymer films under the influence of electrical discharges. This paper shows the ways of increase of stability of polymers to the electrical discharges

  3. Coordination of Series and Shunt Flexible AC Transmission System Devices Based Voltage Source Converter for Improving Power System Stability

    OpenAIRE

    Prechanon Kumkratug

    2011-01-01

    Abstract: Problem statement: Static Synchronous Compensator (STATCOM) and Static Synchronous Series Compensator (SSSC) have been individually applied to improve stability of power system. Approach: This study presents the coordination of a STATCOM and SSSC for improving power system stability. The swing curves of the three phase faulted power system with various cases are tested and compared. Results: The swing curve of system without FACTS devices has undamped oscill...

  4. Ankle replacement - discharge

    Science.gov (United States)

    ... total - discharge; Total ankle arthroplasty - discharge; Endoprosthetic ankle replacement - discharge; Osteoarthritis - ankle ... You had an ankle replacement. Your surgeon removed and reshaped ... an artificial ankle joint. You received pain medicine and were ...

  5. Tennis elbow surgery - discharge

    Science.gov (United States)

    Lateral epicondylitis surgery - discharge; Lateral tendinosis surgery - discharge; Lateral tennis elbow surgery - discharge ... Soon after surgery, severe pain will decrease, but you may have mild soreness for 3 to 6 months.

  6. Knee joint replacement - discharge

    Science.gov (United States)

    ... Knee replacement - total - discharge; Tricompartmental knee replacement - discharge; Osteoarthritis - knee replacement discharge ... such as downhill skiing or contact sports like football and soccer. But, you should be able to ...

  7. The effect of metal-buffer bilayer drain/source electrodes on the operational stability of the organic field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Karimi-Alavijeh, H.R., E-mail: h.karimi@eng.ui.ac.ir [Department of Electrical Engineering, University of Isfahan, Isfahan (Iran, Islamic Republic of); Ehsani, A. [Department of Electrical and Avionics Engineering, Malek-Ashtar University of Technology, Isfahan (Iran, Islamic Republic of)

    2015-09-01

    In this paper, we have investigated experimentally the effect of different drain/source (D/S) electrodes and charge injection buffer layers on the electrical properties and operational stability of a stilbene organic field effect transistor (OFET). The results show that the organic buffer layer of copper phthalocyanine (CuPc) considerably improves the electrical properties of the transistors, but has a negligible effect on their temporal behavior. On the other hand, inorganic metal-oxide buffer layer of molybdenum oxide (MoO{sub 3}) drastically changes both the electrical properties and operational stability. The functionalities of this metal-oxide tightly depend on the properties of the D/S metallic electrodes. OFETs with Al/MoO{sub 3} as the bilayer D/S electrodes have the best electrical properties: field effect mobility μ{sub eff} = 0.32 cm{sup 2} V{sup −1} s{sup −1} and threshold voltage V{sub TH} = − 5 V and the transistors with Ag/MoO{sub 3} have the longest operational stability. It was concluded that the chemical stability of the metal/metal-oxide or metal/organic interfaces of the bilayer D/S electrodes determine the operational stability of the OFETs. - Highlights: • The effect of buffer layers on the performance of the stilbene OFETs has been investigated. • Inorganic buffer layer improved the electrical and temporal behaviors simultaneously. • Organic buffer layer only changes the electrical properties. • Chemical stability of the interfaces determines the operational stability of the transistor.

  8. Discharge of swine wastes risks water quality and food safety: Antibiotics and antibiotic resistance genes from swine sources to the receiving environments.

    Science.gov (United States)

    He, Liang-Ying; Ying, Guang-Guo; Liu, You-Sheng; Su, Hao-Chang; Chen, Jun; Liu, Shuang-Shuang; Zhao, Jian-Liang

    2016-01-01

    Swine feedlots are widely considered as a potential hotspot for promoting the dissemination of antibiotic resistance genes (ARGs) in the environment. ARGs could enter the environment via discharge of animal wastes, thus resulting in contamination of soil, water, and food. We investigated the dissemination and diversification of 22 ARGs conferring resistance to sulfonamides, tetracyclines, chloramphenicols, and macrolides as well as the occurrence of 18 corresponding antibiotics from three swine feedlots to the receiving water, soil environments and vegetables. Most ARGs and antibiotics survived the on-farm waste treatment processes in the three swine farms. Elevated diversity of ARGs was observed in the receiving environments including river water and vegetable field soils when compared with respective controls. The variation of ARGs along the vertical soil profiles of vegetable fields indicated enrichment and migration of ARGs. Detection of various ARGs and antibiotic residues in vegetables fertilized by swine wastes could be of great concern to the general public. This research demonstrated the contribution of swine wastes to the occurrence and development of antibiotic resistance determinants in the receiving environments and potential risks to food safety and human health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Laser source for dimensional metrology: investigation of an iodine stabilized system based on narrow linewidth 633 nm DBR diode

    Czech Academy of Sciences Publication Activity Database

    Řeřucha, Šimon; Yacoot, A.; Pham, Minh Tuan; Čížek, Martin; Hucl, Václav; Lazar, Josef; Číp, Ondřej

    2017-01-01

    Roč. 28, č. 4 (2017), s. 1-11, č. článku 045204. ISSN 0957-0233 R&D Projects: GA ČR GB14-36681G; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA TA ČR TE01020233 Institutional support: RVO:68081731 Keywords : optical metrology * DBR laser diode * frequency stabilization * laser interferometry * dimensional metrology * iodine stabilization * displacement measurement Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 1.585, year: 2016

  10. Discharge Planning in Chronic Conditions

    Science.gov (United States)

    McMartin, K

    2013-01-01

    Background Chronically ill people experience frequent changes in health status accompanied by multiple transitions between care settings and care providers. Discharge planning provides support services, follow-up activities, and other interventions that span pre-hospital discharge to post-hospital settings. Objective To determine if discharge planning is effective at reducing health resource utilization and improving patient outcomes compared with standard care alone. Data Sources A standard systematic literature search was conducted for studies published from January 1, 2004, until December 13, 2011. Review Methods Reports, randomized controlled trials, systematic reviews, and meta-analyses with 1 month or more of follow-up and limited to specified chronic conditions were examined. Outcomes included mortality/survival, readmissions and emergency department (ED) visits, hospital length of stay (LOS), health-related quality of life (HRQOL), and patient satisfaction. Results One meta-analysis compared individualized discharge planning to usual care and found a significant reduction in readmissions favouring individualized discharge planning. A second meta-analysis compared comprehensive discharge planning with postdischarge support to usual care. There was a significant reduction in readmissions favouring discharge planning with postdischarge support. However, there was significant statistical heterogeneity. For both meta-analyses there was a nonsignificant reduction in mortality between the study arms. Limitations There was difficulty in distinguishing the relative contribution of each element within the terms “discharge planning” and “postdischarge support.” For most studies, “usual care” was not explicitly described. Conclusions Compared with usual care, there was moderate quality evidence that individualized discharge planning is more effective at reducing readmissions or hospital LOS but not mortality, and very low quality evidence that it is more

  11. Stability of the Atlantic overturning circulation: competition between Bering Strait freshwater flux and Agulhas heat and salt sources

    NARCIS (Netherlands)

    Weijer, W.; Ruijter, W.P.M. de; Dijkstra, H.A.

    2000-01-01

    In this study we examine the role that is played by interocean fluxes of buoyancy in stabilizing the present-day overturning circulation of the Atlantic Ocean. A 2D model of the Atlantic overturning circulation is used, in which the interocean fluxes of heat and salt (via the Bering Strait, the

  12. State Waste Discharge Permit application, 100-N Sewage Lagoon

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations (Ecology et al. 1994), the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173--216 (or 173--218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order No. DE 91NM-177, (Ecology and DOE-RL 1991). This document constitutes the State Waste Discharge Permit application for the 100-N Sewage Lagoon. Since the influent to the sewer lagoon is domestic waste water, the State Waste Discharge Permit application for Public Owned Treatment Works Discharges to Land was used. Although the 100-N Sewage Lagoon is not a Public Owned Treatment Works, the Public Owned Treatment Works application is more applicable than the application for industrial waste water. The 100-N Sewage Lagoon serves the 100-N Area and other Hanford Site areas by receiving domestic waste from two sources. A network of sanitary sewer piping and lift stations transfers domestic waste water from the 100-N Area buildings directly to the 100-N Sewage Lagoon. Waste is also received by trucks that transport domestic waste pumped from on site septic tanks and holding tanks. Three ponds comprise the 100-N Sewage Lagoon treatment system. These include a lined aeration pond and stabilization pond, as well as an unlined infiltration pond. Both piped-in and trucked-in domestic waste is discharged directly into the aeration pond.

  13. State Waste Discharge Permit application, 100-N Sewage Lagoon

    International Nuclear Information System (INIS)

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations (Ecology et al. 1994), the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173--216 (or 173--218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order No. DE 91NM-177, (Ecology and DOE-RL 1991). This document constitutes the State Waste Discharge Permit application for the 100-N Sewage Lagoon. Since the influent to the sewer lagoon is domestic waste water, the State Waste Discharge Permit application for Public Owned Treatment Works Discharges to Land was used. Although the 100-N Sewage Lagoon is not a Public Owned Treatment Works, the Public Owned Treatment Works application is more applicable than the application for industrial waste water. The 100-N Sewage Lagoon serves the 100-N Area and other Hanford Site areas by receiving domestic waste from two sources. A network of sanitary sewer piping and lift stations transfers domestic waste water from the 100-N Area buildings directly to the 100-N Sewage Lagoon. Waste is also received by trucks that transport domestic waste pumped from on site septic tanks and holding tanks. Three ponds comprise the 100-N Sewage Lagoon treatment system. These include a lined aeration pond and stabilization pond, as well as an unlined infiltration pond. Both piped-in and trucked-in domestic waste is discharged directly into the aeration pond

  14. Source-pathway-receptor investigation of the fate of trace elements derived from shotgun pellets discharged in terrestrial ecosystems managed for game shooting

    International Nuclear Information System (INIS)

    Sneddon, Jennifer; Clemente, Rafael; Riby, Philip; Lepp, Nicholas W.

    2009-01-01

    Spent shotgun pellets may contaminate terrestrial ecosystems. We examined the fate of elements originating from shotgun pellets in pasture and woodland ecosystems. Two source-receptor pathways: i) soil-soil pore water-plant and ii) whole earthworm/worm gut contents - washed and unwashed small mammal hair were investigated. Concentrations of Pb and associated contaminants were higher in soils from shot areas than controls. Arsenic and lead concentrations were positively correlated in soils, soil pore water and associated biota. Element concentrations in biota were below statutory levels in all locations. Bioavailability of lead to small mammals, based on concentrations in washed body hair was low. Lead movement from soil water to higher trophic levels was minor compared to lead adsorbed onto body surfaces. Lead was concentrated in earthworm gut and some plants. Results indicate that managed game shooting presents minimal risk in terms of element transfer to soils and their associated biota. - Source-receptor pathway analysis of a managed game shooting site showed no environmental risk of trace element transfer.

  15. Effectiveness of Partition and Graph Theoretic Clustering Algorithms for Multiple Source Partial Discharge Pattern Classification Using Probabilistic Neural Network and Its Adaptive Version: A Critique Based on Experimental Studies

    Directory of Open Access Journals (Sweden)

    S. Venkatesh

    2012-01-01

    Full Text Available Partial discharge (PD is a major cause of failure of power apparatus and hence its measurement and analysis have emerged as a vital field in assessing the condition of the insulation system. Several efforts have been undertaken by researchers to classify PD pulses utilizing artificial intelligence techniques. Recently, the focus has shifted to the identification of multiple sources of PD since it is often encountered in real-time measurements. Studies have indicated that classification of multi-source PD becomes difficult with the degree of overlap and that several techniques such as mixed Weibull functions, neural networks, and wavelet transformation have been attempted with limited success. Since digital PD acquisition systems record data for a substantial period, the database becomes large, posing considerable difficulties during classification. This research work aims firstly at analyzing aspects concerning classification capability during the discrimination of multisource PD patterns. Secondly, it attempts at extending the previous work of the authors in utilizing the novel approach of probabilistic neural network versions for classifying moderate sets of PD sources to that of large sets. The third focus is on comparing the ability of partition-based algorithms, namely, the labelled (learning vector quantization and unlabelled (K-means versions, with that of a novel hypergraph-based clustering method in providing parsimonious sets of centers during classification.

  16. Estimating Discharge and Nonpoint Source Nitrate Loading to Streams From Three End-Member Pathways Using High-Frequency Water Quality Data

    Science.gov (United States)

    Miller, Matthew P.; Tesoriero, Anthony J.; Hood, Krista; Terziotti, Silvia; Wolock, David M.

    2017-12-01

    The myriad hydrologic and biogeochemical processes taking place in watersheds occurring across space and time are integrated and reflected in the quantity and quality of water in streams and rivers. Collection of high-frequency water quality data with sensors in surface waters provides new opportunities to disentangle these processes and quantify sources and transport of water and solutes in the coupled groundwater-surface water system. A new approach for separating the streamflow hydrograph into three components was developed and coupled with high-frequency nitrate data to estimate time-variable nitrate loads from chemically dilute quick flow, chemically concentrated quick flow, and slowflow groundwater end-member pathways for periods of up to 2 years in a groundwater-dominated and a quick-flow-dominated stream in central Wisconsin, using only streamflow and in-stream water quality data. The dilute and concentrated quick flow end-members were distinguished using high-frequency specific conductance data. Results indicate that dilute quick flow contributed less than 5% of the nitrate load at both sites, whereas 89 ± 8% of the nitrate load at the groundwater-dominated stream was from slowflow groundwater, and 84 ± 25% of the nitrate load at the quick-flow-dominated stream was from concentrated quick flow. Concentrated quick flow nitrate concentrations varied seasonally at both sites, with peak concentrations in the winter that were 2-3 times greater than minimum concentrations during the growing season. Application of this approach provides an opportunity to assess stream vulnerability to nonpoint source nitrate loading and expected stream responses to current or changing conditions and practices in watersheds.

  17. Investigations on Cs-free alternatives for negative ion formation in a low pressure hydrogen discharge at ion source relevant parameters

    Science.gov (United States)

    Kurutz, U.; Friedl, R.; Fantz, U.

    2017-07-01

    Caesium (Cs) is applied in high power negative hydrogen ion sources to reduce a converter surface’s work function and thus enabling an efficient negative ion surface formation. Inherent drawbacks with the usage of this reactive alkali metal motivate the search for Cs-free alternative materials for neutral beam injection systems in fusion research. In view of a future DEMOnstration power plant, a suitable material should provide a high negative ion formation efficiency and comply with the RAMI issues of the system: reliability, availability, maintainability, inspectability. Promising candidates, like low work function materials (molybdenum doped with lanthanum (MoLa) and LaB6), as well as different non-doped and boron-doped diamond samples were investigated in this context at identical and ion source relevant parameters at the laboratory experiment HOMER. Negative ion densities were measured above the samples by means of laser photodetachment and compared with two reference cases: pure negative ion volume formation with negative ion densities of about 1× {10}15 {{{m}}}-3 and the effect of H- surface production using an in situ caesiated stainless steel sample which yields 2.5 times higher densities. Compared to pure volume production, none of the diamond samples did exhibit a measurable increase in H- densities, while showing clear indications of plasma-induced erosion. In contrast, both MoLa and LaB6 produced systematically higher densities (MoLa: ×1.60 LaB6: ×1.43). The difference to caesiation can be attributed to the higher work functions of MoLa and LaB6 which are expected to be about 3 eV for both compared to 2.1 eV of a caesiated surface.

  18. Analysis of Multipactor Discharge

    International Nuclear Information System (INIS)

    Lau, Y. Y.

    2005-01-01

    Several comprehensive studies of radio frequency (rf) breakdown and rf heating are reported. They are of general interest to magnetic confinement fusion, rf linac, and high power microwave source development. The major results include: (1) a ground-breaking theory of multipactor discharge on dielectric, including a successful proof-of-principle experiment that verified the newly developed scaling laws, (2) an in depth investigation of the failure mechanisms of diamond windows and ceramic windows, and of the roles of graphitization, thin films of coating and contaminants, and (3) a most comprehensive theory, to date, on the heating of particulates by an electromagnetic pulse, and on the roles of rf magnetic field heating and of rf electric field heating, including the construction of new scaling laws that govern them. The above form a valuable knowledge base for the general problem of heating phenomenology

  19. Readiness for hospital discharge: A concept analysis.

    Science.gov (United States)

    Galvin, Eileen Catherine; Wills, Teresa; Coffey, Alice

    2017-11-01

    To report on an analysis on the concept of 'readiness for hospital discharge'. No uniform operational definition of 'readiness for hospital discharge' exists in the literature; therefore, a concept analysis is required to clarify the concept and identify an up-to-date understanding of readiness for hospital discharge. Clarity of the concept will identify all uses of the concept; provide conceptual clarity, an operational definition and direction for further research. Literature review and concept analysis. A review of literature was conducted in 2016. Databases searched were: Academic Search Complete, CINAHL Plus with Full Text, PsycARTICLES, Psychology and Behavioural Sciences Collection, PsycINFO, Social Sciences Full Text (H.W. Wilson) and SocINDEX with Full Text. No date limits were applied. Identification of the attributes, antecedents and consequences of readiness for hospital discharge led to an operational definition of the concept. The following attributes belonging to 'readiness for hospital discharge' were extracted from the literature: physical stability, adequate support, psychological ability, and adequate information and knowledge. This analysis contributes to the advancement of knowledge in the area of hospital discharge, by proposing an operational definition of readiness for hospital discharge, derived from the literature. A better understanding of the phenomenon will assist healthcare professionals to recognize, measure and implement interventions where necessary, to ensure patients are ready for hospital discharge and assist in the advancement of knowledge for all professionals involved in patient discharge from hospital. © 2017 John Wiley & Sons Ltd.

  20. Stability and Convergence of an Effective Numerical Method for the Time-Space Fractional Fokker-Planck Equation with a Nonlinear Source Term

    Directory of Open Access Journals (Sweden)

    Qianqian Yang

    2010-01-01

    fractional Fokker-Planck equations with a nonlinear source term (TSFFPENST, which involve the Caputo time fractional derivative (CTFD of order ∈ (0, 1 and the symmetric Riesz space fractional derivative (RSFD of order ∈ (1, 2]. Approximating the CTFD and RSFD using the L1-algorithm and shifted Grünwald method, respectively, a computationally effective numerical method is presented to solve the TSFFPE-NST. The stability and convergence of the proposed numerical method are investigated. Finally, numerical experiments are carried out to support the theoretical claims.

  1. Compact Intracloud Discharges

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David A. [Univ. of Colorado, Boulder, CO (United States)

    1998-11-01

    In November of 1993, mysterious signals recorded by a satellite-borne broadband VHF radio science experiment called Blackboard led to a completely unexpected discovery. Prior to launch of the ALEXIS satellite, it was thought that its secondary payload, Blackboard, would most often detect the radio emissions from lightning when its receiver was not overwhelmed by noise from narrowband communication carriers. Instead, the vast majority of events that triggered the instrument were isolated pairs of pulses that were one hundred times more energetic than normal thunderstorm electrical emissions. The events, which came to be known as TIPPs (for transionospheric pulse pairs), presented a true mystery to the geophysics community. At the time, it was not even known whether the events had natural or anthropogenic origins. After two and one half years of research into the unique signals, two ground-based receiver arrays in New Mexico first began to detect and record thunderstorm radio emissions that were consistent with the Blackboard observations. On two occasions, the ground-based systems and Blackboard even recorded emissions that were produced by the same exact events. From the ground based observations, it has been determined that TIPP events areproduced by brief, singular, isolated, intracloud electrical discharges that occur in intense regions of thunderstorms. These discharges have been dubbed CIDS, an acronym for compact intracloud discharges. During the summer of 1996, ground-based receiver arrays were used to record the electric field change signals and broadband HF emissions from hundreds of CIDS. Event timing that was accurate to within a few microseconds made possible the determination of source locations using methods of differential time of arrival. Ionospheric reflections of signals were recorded in addition to groundwave/line-of-sight signals and were used to determine accurate altitudes for the discharges. Twenty-four CIDS were recorded from three

  2. 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.

  3. Vessel Sewage Discharges

    Science.gov (United States)

    Vessel sewage discharges are regulated under Section 312 of the Clean Water Act, which is jointly implemented by the EPA and Coast Guard. This homepage links to information on marine sanitation devices and no discharge zones.

  4. Foot amputation - discharge

    Science.gov (United States)

    Amputation - foot - discharge; Trans-metatarsal amputation - discharge ... You have had a foot amputation. You may have had an accident, or your foot may have had an infection or disease and doctors could ...

  5. Elbow replacement - discharge

    Science.gov (United States)

    Total elbow arthroplasty - discharge; Endoprosthetic elbow replacement - discharge ... Pain is normal after elbow replacement surgery. It should get better over time. Your doctor will give you a prescription for pain medicine. Get it filled when ...

  6. Vaginal delivery - discharge

    Science.gov (United States)

    Pregnancy - discharge after vaginal delivery ... return in: 4 to 9 weeks after your delivery if you're not breastfeeding 3 to 12 ... can start sexual activity around 6 weeks after delivery, if the discharge or lochia has stopped. Women ...

  7. Influence of the datasets size on the stability of the LR in the lower region of the within source distribution

    NARCIS (Netherlands)

    Haraksim, Rudolf; Meuwly, Didier

    2013-01-01

    This article focuses on the statistical evaluation of the fingermark evidence using the likelihood ratio (LR) approach. It studies the influence of the quantity of data used to model the within (WS) and between (BS) source variability. The LR system built for the experiment uses an Automated

  8. Stability of source mechanisms inverted from P-wave amplitude microseismic monitoring data acquired at the surface

    Czech Academy of Sciences Publication Activity Database

    Staněk, František; Eisner, Leo; Moser, T.J.

    2014-01-01

    Roč. 62, č. 3 (2014), s. 475-490 ISSN 0016-8025 R&D Projects: GA ČR GAP210/12/2451 Institutional support: RVO:67985891 Keywords : microseismic monitoring * inversion * ray modelling * source mechanism Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.506, year: 2013

  9. The vapor-phase multi-stage CMD test for characterizing contaminant mass discharge associated with VOC sources in the vadose zone: Application to three sites in different lifecycle stages of SVE operations.

    Science.gov (United States)

    Brusseau, M L; Mainhagu, J; Morrison, C; Carroll, K C

    2015-08-01

    Vapor-phase multi-stage contaminant mass discharge (CMD) tests were conducted at three field sites to measure mass discharge associated with contaminant sources located in the vadose zone. The three sites represent the three primary stages of the soil vapor extraction (SVE) operations lifecycle-pre/initial-SVE, mid-lifecycle, and near-closure. A CMD of 32g/d was obtained for a site at which soil vapor SVE has been in operation for approximately 6years, and for which mass removal is currently in the asymptotic stage. The contaminant removal behavior exhibited for the vapor extractions conducted at this site suggests that there is unlikely to be a significant mass of non-vapor-phase contaminant (e.g., DNAPL, sorbed phase) remaining in the advective domains, and that most remaining mass is likely located in poorly accessible domains. Given the conditions for this site, this remaining mass is hypothesized to be associated with the low-permeability (and higher water saturation) region in the vicinity of the saturated zone and capillary fringe. A CMD of 25g/d was obtained for a site wherein SVE has been in operation for several years but concentrations and mass-removal rates are still relatively high. A CMD of 270g/d was obtained for a site for which there were no prior SVE operations. The behavior exhibited for the vapor extractions conducted at this site suggest that non-vapor-phase contaminant mass (e.g., DNAPL) may be present in the advective domains. Hence, the asymptotic conditions observed for this site most likely derive from a combination of rate-limited mass transfer from DNAPL (and sorbed) phases present in the advective domain as well as mass residing in lower-permeability ("non-advective") regions. The CMD values obtained from the tests were used in conjunction with a recently developed vapor-discharge tool to evaluate the impact of the measured CMDs on groundwater quality. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Potential sources of hydrogel stabilization of Florida Bay lime mud sediments and implications for organic matter preservation

    Science.gov (United States)

    Louda, J.W.; Loitz, J.W.; Melisiotis, A.; Orem, W.H.

    2004-01-01

    The fine grained carbonate mud sediments of central Florida Bay are resuspended quite easily. However, this disturbance is usually limited to the surficial ('floc') layer, as the underlying sediments appear to be stabilized by an hydrogelation involving the bulk organic matter. That gelation has occurred within these sediments is suggested from their physical behavior and an observed mathematical relationship between the percentages of organic carbon (C org) and water. Specifically, when extruded from a core barrel, the sediment maintains its integrity and has the consistency of a fine spackling compound. However, upon homogenization, as with a stirring rod prior to sieving, these sediments break into two distinct phases, 1/2-2/3 milky water and 1/3-1/2 sediment grains, by volume. The relationship observed between Corg and water was modeled as both linear (% water = (0.0777) Corg + 0.2984, R2 = 0.8664) and logarithmic (% water = 0.2489 Ln Corg + 0.2842, R2 = 0.9455) functions. As this relationship tends to be asymptotic at higher Corg (>3.5% dry)/water values (>60%) and given an higher correlation, the relationship appears better modeled as a logarithmic function. Values of C org from 1.2 to over 6.5%dry wt. and water contents from 30 to over 70%wt. were observed. The calculated intercept revealed that, without organic carbon (viz. hydrogel formation), these carbonates would likely contain only ???30% water by weight ('m' from linear model). This gelation is proposed to involve exopolymeric substances (EPS), likely polysaccharides, derived from diatoms and cyanobacteria of the microphytobenthos. A cyanobacterial-diatomaceous biofilm/mat underlain by purple sulfur bacteria was shown, by pigment based chemotaxonomy, to form the main components of the microphytobenthos. Additional water column detrital biomass, also mainly cyanobacteria and diatoms, is admixed with the living microphytobenthos in a flocculent/nephloid layer above the sediments prior to final

  11. 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 ...

  12. Adaptive shaping system for both spatial and temporal profiles of a highly stabilized UV laser light source for a photocathode RF gun

    Science.gov (United States)

    Tomizawa, H.; Dewa, H.; Taniuchi, T.; Mizuno, A.; Asaka, T.; Yanagida, K.; Suzuki, S.; Kobayashi, T.; Hanaki, H.; Matsui, F.

    2006-02-01

    We have been developing a stable and highly qualified ultraviolet (UV) laser pulse as a light source of an RF gun for an injector candidate of future light sources. Our gun cavity is a single-cell pillbox, and the copper inner wall is used as a photocathode. The chirped pulse amplification (CPA) Ti:sapphire laser system is operated at a repetition rate of 10 Hz. At the third harmonic generation (central wavelength—263 nm), the laser pulse energy after a 45 cm silica rod is up to 850 μJ/pulse. In its present status, the laser's pulse energy stability has been improved down to 0.2˜0.3% at the fundamental, and 0.7-1.4% (rms; 10 pps; 33,818 shots) at the third harmonic generation, respectively. This stability has been held for 1 month continuously, 24 h a day. The improvements we had passively implemented were to stabilize the laser system as well as the environmental conditions. We introduced a humidity-control system kept at 50-60% in a clean room to reduce damage to the optics. In addition, we prepared a deformable mirror for spatial shaping and a spatial light modulator based on fused-silica plates for temporal shaping. We are applying both the adaptive optics to automatic optimization of the electron beam bunch to produce lower emittance with the feedback routine. Before the improvements, the electron beam produced from a cathode suffered inhomogeneous distribution caused by the quantum efficiency effect, and some pulse distortions caused by its response time. However, we can now freely form any arbitrary electron beam distribution on the surface of the cathode.

  13. Power-stabilized tunable narrow-band source using a VCSEL and an EDFA for FBG sensor interrogation

    International Nuclear Information System (INIS)

    Mizunami, Toru; Hirose, Shuji; Yoshinaga, Takeshi; Yamamoto, Ken-ichi

    2013-01-01

    Wavelength tuning with a current of a long-wavelength vertical-cavity surface-emitting laser (VCSEL) was studied for application to wavelength readout of fiber Bragg grating (FBG) sensors. 1.5 µm single-longitudinal-mode VCSELs with a spectral line width of 30 MHz were used. To decrease the variation in the output power with the current, saturated amplification of the VCSEL output by an erbium-doped fiber amplifier (EDFA) was proposed. In the experiment, the wavelength readout of an FBG by variation in the VCSEL current was studied first, and then amplification characteristics using a commercially available EDFA module were measured. Two VCSELs with different wavelengths and tuning ranges were used as input and compared. For a VCSEL with a wavelength tuning range of 2.5 nm, there was a threefold change in the VCSEL output power. However, the variation in the amplified output power was within ±14%. For another VCSEL with a wavelength tuning range of 3.9 nm, the variation in the amplified output power was within ±18% for variation in the VCSEL output power by 2.2 times. The power slope with respect to the wavelength was also decreased by the stabilization. Computer simulation was performed to study the wavelength shift in the measured Bragg wavelength induced by the power slope. The simulation showed that the wavelength shift can be reduced to 1/2.5–1/5 by the stabilization compared with that using a single VCSEL. Application to long-period grating sensors was also discussed. (paper)

  14. Evaluation of the Earth Radiation Budget Experiment (ERBE) shortwave channel's stability using in-flight calibration sources

    Science.gov (United States)

    Gibson, Michael A.; Lee, Robert B., III; Thomas, Susan

    1992-01-01

    The Earth Radiation Budget Experiment (ERBE) radiometers were designed to make absolute measurements of the incoming solar, earth-reflected solar, and earth-emitted fluxes for investigations of the earth's climate system. Thermistor bolometers were the sensors used for the ERBE scanning radiometric package. Each thermistor bolometer package consisted of three narrow field of view broadband radiometric channels measuring shortwave, longwave, and total (0.2 micron to 50 microns) radiation. The in-flight calibration facilities include Mirror Attenuator Mosaics, shortwave internal calibration source, and internal blackbody sources to monitor the long-term responsivity of the radiometers. This paper describes the in-flight calibration facilities, the calibration data reduction techniques, and the results from the in-flight shortwave channel calibrations. The results indicate that the ERBE shortwave detectors were stable to within +/- 1 percent for up to five years of flight operation.

  15. X-ray pre-ionized molecular fluorine laser with a large discharge cross-section

    NARCIS (Netherlands)

    Bastiaens, Hubertus M.J.; Peters, P.J.M.; Witteman, W.J.

    1997-01-01

    High energy extraction from UV pre-ionized molecular fluorine lasers is hampered by the short period of discharge stability and the spatial inhomogeneity of the discharge. So far stable discharge operation is reported for small discharge cross sections with an area less than 0.8 cm2 and efficiencies

  16. [Study of the effect of light source stability on the signal to noise ratio in degenerate four wave mixing experiment].

    Science.gov (United States)

    Wang, Wei-Bo; Chen, De-Ying; Fan, Rong-Wei; Xia, Yuan-Qin

    2010-02-01

    The effects of the stability of dye laser on the signal to noise ratio in degenerate four-wave mixing (DFWM) were first investigated in iodine vapor using forward geometries. Frequency-doubled outputs from a multi-mode Nd : YAG laser pumped dye laser with laser dye PM580 dissolved in ethanol was used. With the help of forward compensated beam-split technique and imaging detecting system, the saturation intensity of DFWM spectrum in the iodine vapor at 5 554.013 nm was first measured to be 290 microJ under the condition of atmospheric pressure and room temperature. The features of the dye laser such as wavelength ranges, beam quality and energy conversion efficiency decreased gradually with increasing pumping service use, pulse number and intensity. Additionally, with the comparison of the stable and unstable dye laser output, it was found that the instability of dye laser output had greatly influenced the DFWM signal and decreased the signal to background noise ratio. Shot to shot jitter and the broadening in the output frequency leads to an effective broadening of the recorded spectrum and loss of the DFWM signal to noise ratio under the same pumping intensity at different time. The study is of importance to the detection of trace atom, molecule and radical in combustion diagnosis.

  17. Improved Passive-Damped LCL Filter to Enhance Stability in Grid-Connected Voltage-Source Converters

    DEFF Research Database (Denmark)

    Beres, Remus Narcis; Wang, Xiongfei; Blaabjerg, Frede

    2015-01-01

    This paper proposes an improved passive-damped LCL filter to be used as interface between the grid-connected voltage-source converters and the utility grid. The proposed filter replaces the LCL filter capacitor with a traditional C-type filter with the resonant circuit tuned in such a way...... passive-damped LCL filter. To verify the benefits of the proposed filter, a comparison with the conventional filter is made in terms of losses and ratings when both the filters are designed under the same condition....... that switching harmonics due to pulse width modulation are to be cancelled. Since the tuned circuit of the C-type filter suppresses the switching harmonics more effectively, the total inductance of the filter can be reduced. Additionally, the rating of the damping resistor is lower, compared with conventional...

  18. Stability analysis of a power system made up of an intermittent renewable energy source directly tied to a conventional rotating power generator

    International Nuclear Information System (INIS)

    Coiante, D.

    1997-02-01

    A simple power system made up of a conventional rotating power generator in direct connection to an intermittent renewable energy source (with energy or photovoltaic) is modelled on the base of respective functional schemes. The relative variations of the voltage frequency are calculated as an output to an abrupt variation of intermittent tied power and in function of electro-mechanical parameters of the rotating generator (dumping coefficient and inertial rotor coefficient). The stability conditions and the tolerance allowed on the frequency variations are considered in relation to toad service requires. As a consequence, the maximum intermittent power amount, which can be accepted in direct connection, is obtained. For usual conventional rotating machines, the resulting limit is placed in the range of (12-19)% of nominal capacity of power generator

  19. Impact of Pressure Regulation of Cryogenic Fluids and EPICS EPID Feedback on the Monochromatic Beam Position Stability of the 7ID Beamline at the Advanced Photon Source

    Science.gov (United States)

    Dufresne, Eric M.; Arms, Dohn A.; Landahl, Eric C.; Walko, Donald A.

    2007-01-01

    The first crystal mount of the double-crystal Si (111) cryogenically cooled monochromator of the 7ID beamline at the Advanced Photon Source (APS) is slightly sensitive to pressure variations in the cryogenic lines. Pressure variations during a liquid nitrogen cryocooler fill every 4 hours move the beam by tens of microns. Pressure variations due to the cryocooler closed-loop pressure control with a heater element (around 0.3 psi) move the beam by 5 microns every 15 seconds. We have recently stabilized the coolant pressure with a simple pressure regulator that is in use at many beamlines of the APS. This paper shows the improvements in beam position stability made using this simple yet effective pressure-regulation circuit. We also recently added beam-position feedback to the second-crystal Bragg angle of the monochromator. The Experimental Physics and Industrial Control System (EPICS) Enhanced Proportional-Integral-Differential (EPID) feedback record implementation resulted in an additional improvement of the standard deviation of the beam position to 0.5 μm.

  20. Early discharge following birth

    DEFF Research Database (Denmark)

    Nilsson, Ingrid M. S.; Kronborg, Hanne; Knight, Christopher H.

    2017-01-01

    of discharge after birth. Results In total 34% mothers were discharged within 12 hours (very early) and 25% between 13 and 50 hours (early), respectively. Vaginal birth and multiparity were the most influential predictors, as Caesarean section compared to vaginal birth had an OR of 0.35 (CI 0....... Smoking, favourable social support and breastfeeding knowledge were significantly associated with discharge within 12 hours. Finally time of discharge varied significantly according to region and time of day of birth. Conclusions Parity and birth related factors were the strongest predictors of early...

  1. Application of MEVVA discharge to material surface modification

    International Nuclear Information System (INIS)

    Gao Yu; Geng Man; Huang Yuming; Gong Xiaorong; Yu Yijun; Tang Deli; Tie Jun

    1996-01-01

    The authors describes some characteristics of the MEVVA discharge, the process of generating a cathode-arc plasma and the advantages of the MEVVA discharge compared with the kind of heating-vaporizing-ionizing source. Some practical parameters and the operating process of the MEVVA ion source as well as a plasma source with MEVVA discharge used in a PSII device are presented. Various plasmas having good-quality and high-performance are obtained with MEVVA discharges and have been widely used in sight-line processing and omnibearing ion implantation for material surface modification

  2. Plasma diagnostics discharge parameters and chemistry

    CERN Document Server

    Auciello, Orlando

    1989-01-01

    Plasma Diagnostics, Volume 1: Discharge Parameters and Chemistry covers seven chapters on the important diagnostic techniques for plasmas and details their use in particular applications. The book discusses optical diagnostic techniques for low pressure plasmas and plasma processing; plasma diagnostics for electrical discharge light sources; as well as Langmuir probes. The text also describes the mass spectroscopy of plasmas, microwave diagnostics, paramagnetic resonance diagnostics, and diagnostics in thermal plasma processing. Electrical engineers, nuclear engineers, microwave engineers, che

  3. Reduced river discharge intensifies phytoplankton bloom in Godavari estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Acharyya, T.; Sarma, V.V.S.S.; Sridevi, B.; Venkataramana, V.; Bharathi, M.D.; Naidu, S.A.; Kumar, B.S.K.; Prasad, V.R.; Bandyopadhyay, D.; Reddy, N.P.C.; DileepKumar, M.

    . The reduced water discharge, during the peak discharge period, slowed the flushing of the estuary from 1.2 days to 6.3 days, respectively. The consequent increase in stability of water column and reduced suspended material load gave rise to intense...

  4. Prostate brachytherapy - discharge

    Science.gov (United States)

    ... nausea or vomiting Any new or unusual symptoms Alternative Names Implant therapy - prostate cancer - discharge; Radioactive seed placement - discharge References D'Amico AV, Nguyen PL, Crook JM, et al. Radiation therapy for prostate cancer. In: Wein AJ, Kavoussi LR, Partin AW, Peters CA, ...

  5. CO-AXIAL DISCHARGES

    Science.gov (United States)

    Luce, J.S.; Smith, L.P.

    1960-11-22

    A method and apparatus are given for producing coaxial arc discharges in an evacuated enclosure and within a strong, confining magnetic field. The arcs are maintained at a high potential difference. Electrons will diffuse to the more positive arc from the negative arc, and positive ions will diffuse from the more positive arc to the negative arc. Coaxial arc discharges have the advantage that ions which return to strike the positive arc discharge will lose no energy since they do not strike a solid wall or electrode. Those discharges are useful in confining an ionized plasma between the discharges, and have the advantage of preventing impurities from the walls of the enclosure from entering ihe plasma area because of the arc barrier set up bv the cylindrical outer arc.

  6. Predicting tile drainage discharge

    DEFF Research Database (Denmark)

    Iversen, Bo Vangsø; Kjærgaard, Charlotte; Petersen, Rasmus Jes

    More than 50 % of Danish agricultural areas are expected to be artificial tile drained. Transport of water and nutrients through the tile drain system to the aquatic environment is expected to be significant. For different mitigation strategies such as constructed wetlands an exact knowledge...... of the water load coming from the tile drainage system is therefore essential. This work aims at predicting tile drainage discharge using dynamic as well as a statistical predictive models. A large dataset of historical tile drain discharge data, daily discharge values as well as yearly average values were...... used in the analysis. For the dynamic modelling, a simple linear reservoir model was used where different outlets in the model represented tile drain as well as groundwater discharge outputs. This modelling was based on daily measured tile drain discharge values. The statistical predictive model...

  7. Transport modelling and gyrokinetic analysis of advanced high performance discharges

    International Nuclear Information System (INIS)

    Kinsey, J.E.; Imbeaux, F.; Staebler, G.M.; Budny, R.; Bourdelle, C.; Fukuyama, A.; Garbet, X.; Tala, T.; Parail, V.

    2005-01-01

    Predictive transport modelling and gyrokinetic stability analyses of demonstration hybrid (HYBRID) and advanced tokamak (AT) discharges from the International Tokamak Physics Activity (ITPA) profile database are presented. Both regimes have exhibited enhanced core confinement (above the conventional ITER reference H-mode scenario) but differ in their current density profiles. Recent contributions to the ITPA database have facilitated an effort to study the underlying physics governing confinement in these advanced scenarios. In this paper, we assess the level of commonality of the turbulent transport physics and the relative roles of the transport suppression mechanisms (i.e. E x B shear and Shafranov shift (α) stabilization) using data for select HYBRID and AT discharges from the DIII-D, JET and AUG tokamaks. GLF23 transport modelling and gyrokinetic stability analysis indicate that E x B shear and Shafranov shift stabilization play essential roles in producing the improved core confinement in both HYBRID and AT discharges. Shafranov shift stabilization is found to be more important in AT discharges than in HYBRID discharges. We have also examined the competition between the stabilizing effects of E x B shear and Shafranov shift stabilization and the destabilizing effects of higher safety factors and parallel velocity shear. Linear and nonlinear gyrokinetic simulations of idealized low and high safety factor cases reveal some interesting consequences. A low safety factor (i.e. HYBRID relevant) is directly beneficial in reducing the transport, and E x B shear stabilization can dominate parallel velocity shear destabilization allowing the turbulence to be quenched. However, at low-q/high current, Shafranov shift stabilization plays less of a role. Higher safety factors (as found in AT discharges), on the other hand, have larger amounts of Shafranov shift stabilization, but parallel velocity shear destabilization can prevent E x B shear quenching of the turbulent

  8. Transport modeling and gyrokinetic analysis of advanced high performance discharges

    International Nuclear Information System (INIS)

    Kinsey, J.; Imbeaux, F.; Bourdelle, C.; Garbet, X.; Staebler, G.; Budny, R.; Fukuyama, A.; Tala, T.; Parail, V.

    2005-01-01

    Predictive transport modeling and gyrokinetic stability analyses of demonstration hybrid (HYBRID) and Advanced Tokamak (AT) discharges from the International Tokamak Physics Activity (ITPA) profile database are presented. Both regimes have exhibited enhanced core confinement (above the conventional ITER reference H-mode scenario) but differ in their current density profiles. Recent contributions to the ITPA database have facilitated an effort to study the underlying physics governing confinement in these advanced scenarios. In this paper, we assess the level of commonality of the turbulent transport physics and the relative roles of the transport suppression mechanisms (i.e. ExB shear and Shafranov shift (α) stabilization) using data for select HYBRID and AT discharges from the DIII-D, JET, and AUG tokamaks. GLF23 transport modeling and gyrokinetic stability analysis indicates that ExB shear and Shafranov shift stabilization play essential roles in producing the improved core confinement in both HYBRID and AT discharges. Shafranov shift stabilization is found to be more important in AT discharges than in HYBRID discharges. We have also examined the competition between the stabilizing effects of ExB shear and Shafranov shift stabilization and the destabilizing effects of higher safety factors and parallel velocity shear. Linear and nonlinear gyrokinetic simulations of idealized low and high safety factor cases reveals some interesting consequences. A low safety factor (i.e. HYBRID relevant) is directly beneficial in reducing the transport, and ExB shear stabilization can win out over parallel velocity shear destabilization allowing the turbulence to be quenched. However, at low-q/high current, Shafranov shift stabilization plays less of a role. Higher safety factors (as found in AT discharges), on the other hand, have larger amounts of Shafranov shift stabilization, but parallel velocity shear destabilization can prevent ExB shear quenching of the turbulent

  9. Ventil – ochrana stability

    Czech Academy of Sciences Publication Activity Database

    Řípa, Milan

    Červenec (2017) ISSN 2464-7888 Institutional support: RVO:61389021 Keywords : fusion * ITER * tokamak * valve * VAT * gyrotron Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) http://www.3pol.cz/cz/rubriky/jaderna-fyzika-a-energetika/2035-ventil-ochrana-stability

  10. Construction Of RF Power Supply For Glow Discharge Plasma

    International Nuclear Information System (INIS)

    Yunanto; Wibowo, Tono; Wirjoadi; Suryadi

    1996-01-01

    A RF power supply for glow discharge plasma has been made, so that on glow discharge reactor appear plasma that can be used make excellent matter. The device consisted of oscillator with LC tank circuit method, RF voltage amplifier, RF power amplifier and matching box. The device can be operated at 4 MHz to 13,56 MHz with optimum power output 30 watt. The RF power supply was coupled through matching box with glow discharge tube of capacitive method and working properly during 8 hours operation. The plasma stabilization has been tested and shows that stabilizations is about 2 x 10 - 2 / hour

  11. Capacitor discharge engineering

    CERN Document Server

    Früngel, Frank B A

    1976-01-01

    High Speed Pulse Technology, Volume III: Capacitor Discharge Engineering covers the production and practical application of capacitor dischargers for the generation and utilization of high speed pulsed of energy in different forms. This nine-chapter volume discusses the principles of electric current, voltage, X-rays, gamma rays, heat, beams of electrons, neutrons and ions, magnetic fields, sound, and shock waves in gases and liquids. Considerable chapters consider the applications of capacitor discharges, such as impulse hardening of steel, ultrapulse welding of precision parts, X-ray flash t

  12. Plasma return current discharge

    International Nuclear Information System (INIS)

    Mangano, J.A.; Hsia, J.; Jacob, J.H.; Srivastava, B.N.

    1978-01-01

    A discharge technique based on the use of an electron-beam-induced plasma return current to produce and heat large-volume plasmas is described. The results of discharge studies using this technique in attachment-dominated mixtures are presented. The results are found to be adequately described by a simple theory. The electron attachment rate by F 2 inferred from these measurements agrees well with those of other workers. KrF laser action at 248 nm is reported in return-current discharge-excited mixtures of F 2 /Kr/He

  13. Biomarker and carbon isotope constraints (δ{sup 13}C, Δ{sup 14}C) on sources and cycling of particulate organic matter discharged by large Siberian rivers draining permafrost areas

    Energy Technology Data Exchange (ETDEWEB)

    Winterfeld, Maria

    2014-08-15

    Circumpolar permafrost soils store about half of the global soil organic carbon pool. These huge amounts of organic matter (OM) could accumulate due to low temperatures and water saturated soil conditions over the course of millennia. Currently most of this OM remains frozen and therefore does not take part in the active carbon cycle, making permafrost soils a globally important carbon sink. Over the last decades mean annual air temperatures in the Arctic increased stronger than the global mean and this trend is projected to continue. As a result the permafrost carbon pool is under climate pressure possibly creating a positive climate feedback due to the thaw-induced release of greenhouse gases to the atmosphere. Arctic warming will lead to increased annual permafrost thaw depths and Arctic river runoff likely resulting in enhanced mobilization and export of old, previously frozen soil-derived OM. Consequently, the great arctic rivers play an important role in global biogeochemical cycles by connecting the large permafrost carbon pool of their hinterlands with the arctic shelf seas and the Arctic Ocean. The first part of this thesis deals with particulate organic matter (POM) from the Lena Delta and adjacent Buor Khaya Bay. The Lena River in central Siberia is one of the major pathways translocating terrestrial OM from its southernmost reaches near Lake Baikal to the coastal zone of the Laptev Sea. The permafrost soils from the Lena catchment area store huge amounts of pre-aged OM, which is expected to be remobilized due to climate warming. To characterize the composition and vegetation sources of OM discharged by the Lena River, the lignin phenol and carbon isotopic composition (δ{sup 13}C and Δ{sup 14}C) in total suspended matter (TSM) from surface waters, surface sediments from the Buor Khaya Bay along with soils from the Lena Delta's first (Holocene) and third terraces (Pleistocene ice complex) were analyzed. The lignin compositions of these samples are

  14. Filament Discharge Phenomena in Fingerprint Acquisition by Dielectric Barrier Discharge

    International Nuclear Information System (INIS)

    Weng Ming; Xu Weijun; Liu Qiang

    2007-01-01

    In this paper, the dielectric barrier discharge fingerprint acquisition technique is introduced. The filament discharge phenomena were observed in the process of fingerprint acquisition. The filament discharge reduced the quality of fingerprint images. Obviously, it was necessary to eliminate streamer discharges in order to get good fingerprint images. The streamer discharge was considered to be the cause of the filament discharge in the experiment. The relationship between the critical electric field and the discharge gap was calculated with the Raether's model of streamer discharge. The calculated results and our experiment proved that it would be difficult for the streamer discharge to occur when the discharge gap was narrow. With a narrow discharge gap, the discharge was homogeneous, and the fingerprint images were clear and large in area. The images obtained in the experiment are very suitable for fingerprint identification as they contain more information

  15. Acoustic signal analysis in the creeping discharge

    International Nuclear Information System (INIS)

    Nakamiya, T; Sonoda, Y; Tsuda, R; Ebihara, K; Ikegami, T

    2008-01-01

    We have previously succeeded in measuring the acoustic signal due to the dielectric barrier discharge and discriminating the dominant frequency components of the acoustic signal. The dominant frequency components appear over 20kHz of acoustic signal by the dielectric barrier discharge. Recently surface discharge control technology has been focused from practical applications such as ozonizer, NO X reactors, light source or display. The fundamental experiments are carried to examine the creeping discharge using the acoustic signal. When the high voltage (6kV, f = 10kHz) is applied to the electrode, the discharge current flows and the acoustic sound is generated. The current, voltage waveforms of creeping discharge and the sound signal detected by the condenser microphone are stored in the digital memory scope. In this scheme, Continuous Wavelet Transform (CWT) is applied to discriminate the acoustic sound of the micro discharge and the dominant frequency components are studied. CWT results of sound signal show the frequency spectrum of wideband up to 100kHz. In addition, the energy distributions of acoustic signal are examined by CWT

  16. Implantable cardioverter defibrillator - discharge

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000108.htm Implantable cardioverter defibrillator - discharge To use the sharing features on this page, please enable JavaScript. An implantable cardioverter-defibrillator (ICD) is a device that detects a life- ...

  17. Hypospadias repair - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000158.htm Hypospadias repair - discharge To use the sharing features on this page, please enable JavaScript. Your child had hypospadias repair to fix a birth defect in which ...

  18. Concussion - child - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000125.htm Concussion in children - discharge To use the sharing features ... enable JavaScript. Your child was treated for a concussion . This is a mild brain injury that can ...

  19. Urethral discharge culture

    Science.gov (United States)

    ... Genital exudate culture; Culture - genital discharge or exudate; Urethritis - culture ... Augenbraun MH, McCormack WM. Urethritis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases . 8th ed. ...

  20. Thyroid gland removal - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000293.htm Thyroid gland removal - discharge To use the sharing features ... surgery. This will make your scar show less. Thyroid Hormone Replacement You may need to take thyroid ...

  1. Atrial fibrillation - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000237.htm Atrial fibrillation - discharge To use the sharing features on this ... have been in the hospital because you have atrial fibrillation . This condition occurs when your heart beats faster ...

  2. Asthma - child - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000001.htm Asthma - child - discharge To use the sharing features on this ... care for your child. Take Charge of Your Child's Asthma at Home Make sure you know the asthma ...

  3. Small bowel resection - discharge

    Science.gov (United States)

    ... Ileostomy and your diet Ileostomy - caring for your stoma Ileostomy - changing your pouch Ileostomy - discharge Ileostomy - what to ask your doctor Low-fiber diet Surgical wound care - open Types of ileostomy Wet-to-dry dressing ...

  4. Kidney stones - lithotripsy - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000136.htm Kidney stones and lithotripsy - discharge To use the sharing features on this page, please enable JavaScript. A kidney stone is a solid mass made up of tiny ...

  5. Chest radiation - discharge

    Science.gov (United States)

    Radiation - chest - discharge; Cancer - chest radiation; Lymphoma - chest radiation ... When you have radiation treatment for cancer, your body goes through changes. About 2 weeks after your first treatment: It may be hard ...

  6. Breast radiation - discharge

    Science.gov (United States)

    Radiation - breast - discharge ... away around 4 to 6 weeks after the radiation treatment is over. You may notice changes in ... breast looks or feels (if you are getting radiation after a lumpectomy). These changes include: Soreness or ...

  7. Brain radiation - discharge

    Science.gov (United States)

    Radiation - brain - discharge; Cancer-brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  8. Epilepsy - children - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000127.htm Epilepsy in children - discharge To use the sharing features ... this page, please enable JavaScript. Your child has epilepsy . People with epilepsy have seizures. A seizure is ...

  9. Epilepsy or seizures - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000128.htm Epilepsy or seizures - discharge To use the sharing features on this page, please enable JavaScript. You have epilepsy . People with epilepsy have seizures. A seizure is ...

  10. Multiple sclerosis - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000129.htm Multiple sclerosis - discharge To use the sharing features on this ... Your doctor has told you that you have multiple sclerosis (MS). This disease affects the brain and spinal ...

  11. Pneumonia - adults - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000017.htm Pneumonia in adults - discharge To use the sharing features on this page, please enable JavaScript. You have pneumonia, which is an infection in your lungs. In ...

  12. Pneumonia - children - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000011.htm Pneumonia in children - discharge To use the sharing features ... this page, please enable JavaScript. Your child has pneumonia, which is an infection in the lungs. In ...

  13. Hip fracture - discharge

    Science.gov (United States)

    ... Philadelphia, PA: Elsevier; 2017:chap 55. Read More Broken bone Hip fracture surgery Hip pain Leg MRI scan Osteoporosis - overview Patient Instructions Getting your home ready - knee or hip surgery Osteomyelitis - discharge Review ...

  14. Valorization of soursop flowers (Annona muricata L.) as potent source of natural antioxidants for stabilization of palm olein during accelerated storage.

    Science.gov (United States)

    Womeni, Hilaire Macaire; Tonfack Djikeng, Fabrice; Iruku, Naga Satya Surya Prabhakar; Karuna, Mallampalli Sri Lakshmi; Prasad, Rachapudi Badari Narayana; Linder, Michel

    2016-11-01

    This study investigates the effect of soursop flowers methanolic extract on the physicochemical characteristics of palm olein during accelerated storage. After analysis of the extract by determining its total phenolic content by colorimetry and identification of some of its phenolic antioxidants by HPLC-DAD(Diode Array Detector), preliminary antioxidants tests have been done. After that, the extract was added in palm olein at concentrations 200-1800 ppm. BHT, at 200 ppm served as standard besides the Control. Induction time, peroxide, p -anisidine, Total oxidation (TOTOX), thiobarbituric acid and iodine values, as well as changes in linoleic acid profile Gas Chromatography/Flamme Ionization Detector (GC/FID) of oil during the storage were evaluated. Results showed soursop flower extract to be rich in phenolic antioxidants and to be efficient, at all concentrations, in delaying palm olein oxidation on Rancimat and accelerated Schaal oven test of 30 days at 70°C. Soursop flowers might be used as potent source of antioxidants for the stabilization of palm olein.

  15. Investigating effects of sample pretreatment on protein stability using size-exclusion chromatography and high-resolution continuum source atomic absorption spectrometry.

    Science.gov (United States)

    Rakow, Tobias; El Deeb, Sami; Hahne, Thomas; El-Hady, Deia Abd; AlBishri, Hassan M; Wätzig, Hermann

    2014-09-01

    In this study, size-exclusion chromatography and high-resolution atomic absorption spectrometry methods have been developed and evaluated to test the stability of proteins during sample pretreatment. This especially includes different storage conditions but also adsorption before or even during the chromatographic process. For the development of the size exclusion method, a Biosep S3000 5 μm column was used for investigating a series of representative model proteins, namely bovine serum albumin, ovalbumin, monoclonal immunoglobulin G antibody, and myoglobin. Ambient temperature storage was found to be harmful to all model proteins, whereas short-term storage up to 14 days could be done in an ordinary refrigerator. Freezing the protein solutions was always complicated and had to be evaluated for each protein in the corresponding solvent. To keep the proteins in their native state a gentle freezing temperature should be chosen, hence liquid nitrogen should be avoided. Furthermore, a high-resolution continuum source atomic absorption spectrometry method was developed to observe the adsorption of proteins on container material and chromatographic columns. Adsorption to any container led to a sample loss and lowered the recovery rates. During the pretreatment and high-performance size-exclusion chromatography, adsorption caused sample losses of up to 33%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Design and Mechanical Stability Analysis of the Interaction Region for the Inverse Compton Scattering Gamma-Ray Source Using Finite Element Method

    Science.gov (United States)

    Khizhanok, Andrei

    Development of a compact source of high-spectral brilliance and high impulse frequency gamma rays has been in scope of Fermi National Accelerator Laboratory for quite some time. Main goal of the project is to develop a setup to support gamma rays detection test and gamma ray spectroscopy. Potential applications include but not limited to nuclear astrophysics, nuclear medicine, oncology ('gamma knife'). Present work covers multiple interconnected stages of development of the interaction region to ensure high levels of structural strength and vibrational resistance. Inverse Compton scattering is a complex phenomenon, in which charged particle transfers a part of its energy to a photon. It requires extreme precision as the interaction point is estimated to be 20 microm. The slightest deflection of the mirrors will reduce effectiveness of conversion by orders of magnitude. For acceptable conversion efficiency laser cavity also must have >1000 finesse value, which requires a trade-off between size, mechanical stability, complexity, and price of the setup. This work focuses on advantages and weak points of different designs of interaction regions as well as in-depth description of analyses performed. This includes laser cavity amplification and finesse estimates, natural frequency mapping, harmonic analysis. Structural analysis is required as interaction must occur under high vacuum conditions.

  17. Chaos in gas discharges

    International Nuclear Information System (INIS)

    Piel, A.

    1993-01-01

    Many gas discharges exhibit natural oscillations which undergo a transition from regular to chaotic behavior by changing an experimental parameter or by applying external modulation. Besides several isolated investigations, two classes of discharge phenomena have been studied in more detail: ionization waves in medium pressure discharges and potential relaxation oscillations in filament cathode discharges at very low pressure. The latter phenomenon will be discussed by comparing experimental results from different discharge arrangements with particle-in-cell simulations and with a model based on the van-der-Pol equation. The filament cathode discharge has two stable modes of operation: the low current anode-glow-mode and the high current temperature-limited-mode, which form the hysteresis curve in the I(U) characteristics. Close to the hysteresis point of the AGM periodic relaxation oscillations occur. The authors demonstrate that the AGM can be understood by ion production in the anode layer, stopping of ions by charge exchange, and trapping in the virtual cathode around the filament. The relaxation oscillations consist of a slow filling phase and a rapid phase that invokes formation of an unstable double-layer, current-spiking, and ion depletion from the cathodic plasma. The relaxation oscillations can be mode-locked by external modulation. Inside a mode-locked state, a period doubling cascade is observed at high modulation degree

  18. Identifying discharge practice training needs.

    Science.gov (United States)

    Lees, L; Emmerson, K

    A training needs analysis tool was developed to identify nurses' discharge training needs and to improve discharge practice. The tool includes 49 elements of discharge practice subdivided into four areas: corporate, operational, clinical and nurse-led discharge. The tool was disseminated to 15 wards on two hospital sites with assistance from the practice development team. Analysis of discharge training is important to assess discharge training needs and to identify staff who may assist with training.

  19. Thermal modeling of cylindrical lithium ion battery during discharge cycle

    International Nuclear Information System (INIS)

    Jeon, Dong Hyup; Baek, Seung Man

    2011-01-01

    Highlights: → Transient and thermo-electric finite element analysis (FEA) of cylindrical lithium ion (Li-ion) battery was presented. → This model provides the thermal behavior of Li-ion battery during discharge cycle. → A LiCoO 2 /C battery at various discharge rates was investigated. → The contribution of heat source due to joule heating was significant at a high discharge rate. → The contribution of heat source due to entropy change was dominant at a low discharge rate. - Abstract: Transient and thermo-electric finite element analysis (FEA) of cylindrical lithium ion (Li-ion) battery was presented. The simplified model by adopting a cylindrical coordinate was employed. This model provides the thermal behavior of Li-ion battery during discharge cycle. The mathematical model solves conservation of energy considering heat generations due to both joule heating and entropy change. A LiCoO 2 /C battery at various discharge rates was investigated. The temperature profile from simulation had similar tendency with experiment. The temperature profile was decomposed with contributions of each heat sources and was presented at several discharge rates. It was found that the contribution of heat source due to joule heating was significant at a high discharge rate, whereas that due to entropy change was dominant at a low discharge rate. Also the effect of cooling condition and the LiNiCoMnO 2 /C battery were analyzed for the purpose of temperature reduction.

  20. UK strategy for radioactive discharges 2001-2020. Consultation document

    International Nuclear Information System (INIS)

    2000-06-01

    This consultation draft of a strategy for radioactive discharges describes how the United Kingdom (UK) will implement the agreements reached at the 1998 Ministerial meeting of the OSPAR Commission, with regard to radioactive substances. It also provides a policy base for future reviews of discharge authorisations by the regulatory bodies and for strategic planning by the nuclear operators. The strategy sets a framework for radioactive discharges from UK installations over the next twenty years. Its aims are: progressive and substantial reductions in radioactive discharges from the UK as a whole and from each of the main sectors responsible for such discharges; progressive reduction of human exposure to ionising radiation resulting from radioactive discharges, so that no member of the general public in the UK will be exposed to a dose of more than 0.02 mSv a year, as a result of authorised radioactive discharges made from 2020 onwards; progressive reductions in concentrations of radionuclides in the marine environment resulting from radioactive discharges, such that by 2020 they add close to zero to historic levels. The scope of the UK strategy encompasses radioactive discharges from nuclear licensed sites, defence activities and other nuclear and non-nuclear sources of radioactive discharges. It covers both liquid and aerial discharges, although it is assumed that in general liquid discharges will have the largest and most measurable effects in the marine environment

  1. Nanomaterials synthesis at atmospheric pressure using nanosecond discharges

    International Nuclear Information System (INIS)

    Pai, David Z

    2011-01-01

    The application of nanosecond discharges towards nanomaterials synthesis at atmospheric pressure is explored in this perspective article. First, various plasma sources are evaluated in terms of the energy used to include one atom into the nanomaterial, which is shown to depend strongly on the electron temperature. Because of their high average electron temperature, nanosecond discharges could be used to achieve nanofabrication at a lower energy cost, and therefore with better efficiency, than with other plasma sources at atmospheric pressure. Transient spark discharges and nanosecond repetitively pulsed (NRP) discharges are suggested as particularly useful examples of nanosecond discharges generated at high repetition frequency. Nanosecond discharges also generate fast heating and cooling rates that could be exploited to produce metastable nanomaterials.

  2. Investigations of MHD activity in ASDEX discharges

    International Nuclear Information System (INIS)

    Stambaugh, R.; Gernhardt, J.; Klueber, O.; Wagner, F.

    1984-06-01

    This report makes a strong attempt to relate some specific observations of MHD activity in ADEX discharges to observations made on the Doublet III and PDX tokamaks and to theoretical work on high β MHD modes at GA and PPPL. Three topics are discussed. The first topic is the detailed analysis of the time history of MHD activity in a β discharge. The β limit discharge in ASDEX is identified as a discharge in which, during constant neutral beam power, β reaches a maximum and then decreases, often to a lower steady level if the heating pulse is long enough. During the L phase of this discharge, the MHD activity observed in the B coils is both a continuous and bursting coupled m >= 1 mode of the 'fishbone' type. When β is rising in the H phase, this mode disappears; only ELMs are present. At βsub(max), a different mode appears, the m=2, n=1 tearing mode, which grows rapidly as β decreases. The second topic is the very new observation of the fishbone-like mode in a discharge heated by combined neutral beam and ion cyclotron heating power. The mode characteristics are modulated by sawtooth oscillations in a manner consistent with the importance of q(0) in the stability of this mode. The third topic is the search for ELM precursors in discharges designed to have no other competing and complicating MHD activity. In these cases nonaxisymmetric precursors to the Hsub(α) spike were observed. Hence, it appears that an MHD mode, rather than an energy balance problem, must be the origin of the ELM. (orig./GG)

  3. Oil based mud discharges

    International Nuclear Information System (INIS)

    Tiesma, R.

    1996-01-01

    The intensive use of oil based muds by the offshore oil and gas industry during the 1980s has caused considerable contamination around drilling sites. A recent investigation on the Norwegian continental shelf indicates that the situation is much worse than previously thought. This material suggests that oil pollution of this kind could be damaging the North Sea's endangered fish stocks, including cod, haddock and plaice. The amount of oil discharged in the UK sector is many times higher than in the other sectors, suggesting that the problem there may be even more serious. The amount discharged in the Dutch and Norwegian sectors are comparable. (author)

  4. [Diagnosis of vaginal discharge].

    Science.gov (United States)

    Böcher, Sidsel; Helmig, Rikke Bek; Arpi, Magnus; Bjerrum, Lars

    2018-01-15

    Changes in vaginal discharge are often caused by imbalance in the vaginal microflora, and laboratory testing is usually of little use, as most microbes detected are commensals. In-office diagnosis in general practice using wet mount microscopy and Amsel criteria is helpful and often sufficient to ensure correct diagnosis and treatment. Laboratory testing of vaginal discharge should only be performed, if sexually transmitted disease is suspected, if there is treatment failure or inconclusive wet mount prior to gynaecological surgery, and in pregnant women with recurrent miscarriage or preterm birth.

  5. Red herring vaginal discharge.

    Science.gov (United States)

    Lee, Jun Hee; Pringle, Kirsty; Rajimwale, Ashok

    2013-09-18

    Labial hair tourniquet syndrome is a rare condition that can be easily misdiagnosed and ultimately lead to irreversible damage. An 11-year-old premenarche girl presented with a 5-day history of pain and swelling in the labia with associated vaginal discharge. The general practitioner treated her with clotrimazole without improvement. On examination, there was an oedematous swelling of the right labia with a proximal hair tourniquet. Local anaesthetic was applied and the hair removed with forceps. There was instant relief of pain and the discharge stopped within 24 h. The patient was sent home with a course of antibiotics.

  6. Discharges from nuclear power stations

    International Nuclear Information System (INIS)

    1991-02-01

    HM Inspectorate of Pollution commissioned, with authorising responsibilities in England and Wales, a study into the discharges of radioactive effluents from Nuclear Power Stations. The study considered arisings from nuclear power stations in Europe and the USA and the technologies to treat and control the radioactive discharges. This report contains details of the technologies used at many nuclear power stations to treat and control radioactive discharges and gives, where information was available, details of discharges and authorised discharge limits. (author)

  7. Heart bypass surgery - discharge

    Science.gov (United States)

    ... trouble with short-term memory or feel confused ("fuzzy-headed") Be tired or not have much energy ... or a fever over 101°F (38.3°C). Alternative Names Off-pump coronary artery bypass - discharge; ...

  8. Electrical Discharge Machining.

    Science.gov (United States)

    Montgomery, C. M.

    The manual is for use by students learning electrical discharge machining (EDM). It consists of eight units divided into several lessons, each designed to meet one of the stated objectives for the unit. The units deal with: introduction to and advantages of EDM, the EDM process, basic components of EDM, reaction between forming tool and workpiece,…

  9. MANAGEMENT OF VAGINAL DISCHARGE

    African Journals Online (AJOL)

    Enrique

    , an oral antifungal should be used weekly, e.g. 100 mg flucona- zole.7. The discharge of candidiasis is curd- like and adherent due to direct hyphal invasion of epithelial tissues resulting in erythema of the vaginal epithelium. Clinical diagnosis ...

  10. Ulcerative colitis - discharge

    Science.gov (United States)

    ... doctor - child Diarrhea - what to ask your health care provider - adult Enteral nutrition - child - managing problems Gastrostomy feeding tube - bolus Ileostomy and your child Ileostomy and your diet Ileostomy - caring for your stoma Ileostomy - discharge Jejunostomy feeding tube Living with your ...

  11. Crohn disease - discharge

    Science.gov (United States)

    ... doctor - child Diarrhea - what to ask your health care provider - adult Enteral nutrition - child - managing problems Gastrostomy feeding tube - bolus Ileostomy and your child Ileostomy and your diet Ileostomy - caring for your stoma Ileostomy - discharge Jejunostomy feeding tube Living with your ...

  12. Cosmetic breast surgery - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000273.htm Cosmetic breast surgery - discharge To use the sharing features on this ... Editorial team. Related MedlinePlus Health Topics Plastic and Cosmetic Surgery Browse the Encyclopedia A.D.A.M., Inc. ...

  13. Pellet fuelling in Tore Supra long discharges

    Science.gov (United States)

    Géraud, A.; Bucalossi, J.; Loarer, T.; Pégourié, B.; Grisolia, C.; Gros, G.; Gunn, J.

    2005-03-01

    A new pellet injector, able to inject continuously hydrogen or deuterium pellets, was installed on Tore Supra in 2003 and preliminary experiments aiming to fuel long discharges were performed. In combination with Lower Hybrid (LH) Current Drive, pure pellet fuelled discharges lasting up to 2 min were achieved. The LH power was switched off just before each pellet injection (LH notching) to maintain a relatively deep pellet penetration by reducing the energy of the super-thermal electrons driven by the LH wave. A comparison, based on a particle balance study, between two comparable pellet fuelled and gas fuelled discharges has been done. In the two cases, the volume average density is the same and the analysis shows that the particle source, the pumped flux and the wall retention are similar and appear to be independent of the fuelling method for the low plasma current and density conditions considered ( Ip = 0.6 MA, = 1.5 × 10 19 m -3).

  14. Vessel Sewage Discharges: No-Discharge Zones (NDZs)

    Science.gov (United States)

    States may petition the EPA to establish areas, called no discharge zones (NDZs), where vessel sewage discharges are prohibited. This page describes how NDZs are designated, the types of designations, who enforces them, and how to comply.

  15. GASEOUS DISCHARGE DEVICE

    Science.gov (United States)

    Gow, J.D.

    1961-01-10

    An extremely compact two-terminal gaseous discharge device is described that is capable of producing neutrons in copious quantities, relatively high energy ions, intense x rays, and the like. Principal novelty resides in the provision of a crossed electric-magnetic field region in the discharge envelope that traps electrons and accelerates them to very high energies to provide an intense ionizing medium adjacent the anode of the device for ionizing gas therein with extremely high efficiency. In addition, the crossed-field trapping region holds the electrons close to the anode whereby the acceleration of ions to the cathode is not materially effected by the electron sheath and the ions assume substantially the full energy of the anodecathode potential drop. (auth)

  16. Discharge pulse phenomenology

    Science.gov (United States)

    Frederickson, A. R.

    1985-01-01

    A model was developed which places radiation induced discharge pulse results into a unified conceptual framework. Only two phenomena are required to interpret all space and laboratory results: (1) radiation produces large electrostatic fields inside insulators via the trapping of a net space charge density; and (2) the electrostatic fields initiate discharge streamer plasmas similar to those investigated in high voltage electrical insulation materials; these streamer plasmas generate the pulsing phenomena. The apparent variability and diversity of results seen is an inherent feature of the plasma streamer mechanism acting in the electric fields which is created by irradiation of the dielectrics. The implications of the model are extensive and lead to constraints over what can be done about spacecraft pulsing.

  17. Investigation of Combined High-Frequency and Arc Discharges

    International Nuclear Information System (INIS)

    Taran, V.S.; Nezovibatko, Yu.N.; Marinin, V.G.; Shvets, O.M.; Ridozub, V.N.; Gasilin, V.V.

    2001-01-01

    In this paper we analyze experiment with arc and high-frequency (HF) plasma sources carried out in modified devise of the ''Bulat'' type. The HF-sources and combined discharges have attracted considerable attention for surface cleaning and coating. The utilization of such discharges allows decreasing droplet fraction formation and providing better adhesion and microhardness values. The existence of HF-field in plasma allows obtaining either conductive or dielectric coatings and they can be deposited on any substrates. (author)

  18. Monitoring of lightning discharge

    International Nuclear Information System (INIS)

    Grigor'ev, V.A.

    2001-01-01

    The paper presents a brief description of a lightning discharge recording system developed at the NPO 'Monitoring Techniques' under the direction of V.M. Moskolenko (Moscow). The system provides information about dangerous environmental occurrences such as tornados and hurricanes, making the forecast of extreme situations possible, especially in the areas of dangerous industries and objects. The created automatic system can be useful in solving the tasks relating to nuclear test monitoring. (author)

  19. The human discharge chain

    Science.gov (United States)

    Dudley, Scott C.; Heerema, Bret D.; Haaland, Ryan K.

    1997-06-01

    The common classroom demonstration of a human chain, charged by a Van de Graaff generator, and then discharged via the person at the end of the chain touching ground, is analyzed as a capacitor and resistor circuit model. The energy deposited in each person in the chain is determined. Further, the effect of increasing energy deposited in the person who touched ground, as the number of people in the chain is increased, is shown and quantified.

  20. Vaginal itching and discharge - child

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003159.htm Vaginal itching and discharge - child To use the sharing features on this ... problem in girls before the age of puberty. Vaginal discharge may also be present. The color, smell, and ...

  1. Spleen removal - open - adults - discharge

    Science.gov (United States)

    ... discharge; Spleen removal - adult - discharge References Poulose BK, Holzman MD. The spleen. In: Townsend CM, Beauchamp RD, ... provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial ...

  2. Rapid analysis of pesticide residues in drinking water samples by dispersive solid-phase extraction based on multiwalled carbon nanotubes and pulse glow discharge ion source ion mobility spectrometry.

    Science.gov (United States)

    Zou, Nan; Gu, Kejia; Liu, Shaowen; Hou, Yanbing; Zhang, Jialei; Xu, Xiang; Li, Xuesheng; Pan, Canping

    2016-03-01

    An analytical method based on dispersive solid-phase extraction with a multiwalled carbon nanotubes sorbent coupled with positive pulse glow discharge ion mobility spectrometry was developed for analysis of 30 pesticide residues in drinking water samples. Reduced ion mobilities and the mass-mobility correlation of 30 pesticides were measured. The pesticides were divided into five groups to verify the separation capability of pulse glow discharge in mobility spectrometry. The extraction conditions such as desorption solvent, ionic strength, conditions of adsorption and desorption, the amounts of multiwalled carbon nanotubes, and solution pH were optimized. The enrichment factors of pesticides were 5.4- to 48.7-fold (theoretical enrichment factor was 50-fold). The detection limits of pesticides were 0.01∼0.77 μg/kg. The linear range was 0.005-0.2 mg/L for pesticide standard solutions, with determination coefficients from 0.9616 to 0.9999. The method was applied for the analysis of practical and spiked drinking water samples. All results were confirmed by high-performance liquid chromatography with tandem mass spectrometry. The proposed method was proven to be a commendably rapid screening qualitative and semiquantitative technique for the analysis of pesticide residues in drinking water samples on site. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. 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.

  4. Continuous pile discharging machine

    International Nuclear Information System (INIS)

    Smith, P.P.

    1976-01-01

    A device for discharging cartridges from tubes under fluid pressure includes a cylindrical housing adapted to be seated in a leak-tight manner on the end of one of the tubes, a chute depending from the cylindrical housing near the end seated on the end of the tube, a rotatable piston having a wrench on the forward end thereof disposed in the cylindrical housing and adapted to manipulate a plug in the end of the tube, and a telescopic hydraulic ram adapted to move the piston toward the plug. In addition the wrench contains a magnet which prevents inadvertent uncoupling of the wrench and the plug. 7 claims, 10 drawing figures

  5. Continuous pile discharging machine

    Science.gov (United States)

    Smith, Phillips P.

    1976-05-11

    A device for discharging cartridges from tubes under fluid pressure includes a cylindrical housing adapted to be seated in a leak-tight manner on the end of one of the tubes, a chute depending from the cylindrical housing near the end seated on the end of the tube, a rotatable piston having a wrench on the forward end thereof disposed in the cylindrical housing and adapted to manipulate a plug in the end of the tube, and a telescopic hydraulic ram adapted to move the piston toward the plug. In addition the wrench contains a magnet which prevents inadvertent uncoupling of the wrench and the plug.

  6. Dischargers_Example.png | ECHO | US EPA

    Science.gov (United States)

    ECHO, Enforcement and Compliance History Online, provides compliance and enforcement information for approximately 800,000 EPA-regulated facilities nationwide. ECHO includes permit, inspection, violation, enforcement action, and penalty information about facilities regulated under the Clean Air Act (CAA) Stationary Source Program, Clean Water Act (CWA) National Pollutant Elimination Discharge System (NPDES), and/or Resource Conservation and Recovery Act (RCRA). Information also is provided on surrounding demographics when available.

  7. Dielectric barrier discharges applied for soft ionization and their mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Sebastian; Klute, Felix David; Schütz, Alexander; Franzke, Joachim, E-mail: joachim.franzke@isas.de

    2017-01-25

    Dielectric barrier discharges are used for analytical applications as dissociative source for optical emission spectrometry and for ambient-ionization techniques. In the range of ambient-ionization techniques it has attracted much attention in fields like food safety, biological analysis, mass spectrometry for reaction monitoring and imaging forensic identification. In this review some examples are given for the application as desorption/ionization source as well as for the sole application as ionization source with different sample introductions. It will be shown that the detection might depend on the certain distance of the plasma in reference to the sample or the kind of discharge which might be produced by different shapes of the applied high voltage. Some attempts of characterization are presented. A more detailed characterization of the dielectric barrier discharge realized with two ring electrodes, each separately covered with a dielectric layer, is described. - Highlights: • Dielectric barrier discharge applied as desorption/ionization source. • Dielectric barrier discharge applied solely as ionization source. • Different geometries in order to maintain soft ionization. • Characterization of the LTP probe. • Dielectric barrier discharges with two dielectric barriers (ring-ring shape).

  8. Simulation of the MHD stabilities of the experiment on HL-2A tokamak by GATO code

    International Nuclear Information System (INIS)

    Pan Wei; Chen Liaoyuan; Dong Jiaqi; Shen Yong; Zhang Jinhua

    2009-01-01

    The ideal two-dimensional MHD stabilities code, GATO, has been successfully immigrated to the high-performance computing system of HL-2A and used to the simulation study of the ideal MHD stabilities of the plasmas produced by one of the pellets injection experiments on HL-2A tokamak. The EFIT code was used to reconstruct the equilibrium configures firstly and the GATO was used to compute their MHD stabilities secondly whose source data were obtained by the NO.4050 discharge of the experiments on HL-2A, and finally by analyzing these results the preliminary conclusion was devised that the confinement performance of the plasma was improved because of the stabilization effect of the anti-sheared configures created by the pellets injection. (authors)

  9. Cable Stability

    CERN Document Server

    Bottura, L

    2014-01-01

    Superconductor stability is at the core of the design of any successful cable and magnet application. This chapter reviews the initial understanding of the stability mechanism, and reviews matters of importance for stability such as the nature and magnitude of the perturbation spectrum and the cooling mechanisms. Various stability strategies are studied, providing criteria that depend on the desired design and operating conditions.

  10. High-radiance LDP source: clean, reliable, and stable EUV source for mask inspection

    Science.gov (United States)

    Teramoto, Yusuke; Santos, Bárbara; Mertens, Guido; Kops, Ralf; Kops, Margarete; von Wezyk, Alexander; Bergmann, Klaus; Yabuta, Hironobu; Nagano, Akihisa; Ashizawa, Noritaka; Taniguchi, Yuta; Shirai, Takahiro; Nakamura, Kiyotada; Aoki, Kazuya; Kasama, Kunihiko

    2016-03-01

    High-throughput and -resolution actinic mask inspection tools are needed as EUVL begins to enter into volume production phase. To realize such inspection tools, a high-radiance EUV source is necessary. Ushio's laser-assisted discharge-produced plasma (LDP) source is able to meet industry's requirements in radiance, cleanliness, stability and reliability. Ushio's LDP source has shown the peak radiance at plasma of 180 W/mm2/sr and the area-averaged radiance in a 200-μm-diameter circle behind the debris mitigation system of 120 W/mm2/sr. A new version of the debris mitigation system is in testing phase. Its optical transmission was confirmed to be 73 %, which is 4 % lower than that of the previous version and therefore will be improved. Cleanliness of the system is evaluated by exposing Ru mirrors placed behind the debris mitigation system. Ru sputter rate was proven to be sufficiently low as 3~5 nm/Gpulse at 7 kHz, whereas frequency-dependent sputter rate was 1~3 nm/Gpulse at 5~9 kHz as previously reported. Sn deposition remained very low (discharge frequencies. Pulse energy stability was approximately 10 %. Dose energy stability dropped from approximately 2 % to 0.1 % when feedback control was activated. EUV emission position stability was studied at 3 kHz. Deviation of the plasma center of gravity was 6 μm, which is 3 % of plasma diameter and therefore considered to be negligible. Reliability tests were performed on both R and D and prototype machines and up to 200 hours of non-interrupted operation was demonstrated.

  11. Heart bypass surgery - minimally invasive - discharge

    Science.gov (United States)

    ... invasive direct coronary artery bypass - discharge; MIDCAB - discharge; Robot assisted coronary artery bypass - discharge; RACAB - discharge; Keyhole ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  12. Transport simulation of negative magnetic shear discharges

    International Nuclear Information System (INIS)

    St. John, H.; Taylor, T.S.; Lin-Liu, Y.R.; Turnbull, A.D.

    1994-10-01

    In the present work the authors present simulations which show that the hollow current profile can be maintained in quasi-steady state through a self-consistently determined combination of bootstrap current and neutral beam and rf current drive. Controllability of the q profile is demonstrated by eliminating low m/n mode number instabilities from these discharges by maintaining q > 1.5 at all times, starting from appropriate initial conditions. At moderately high β p , the bootstrap current can be a substantial fraction of the total current and the ability to maintain the proper total current density profile depends on the bootstrap current profile and the availability of suitable localized heating and current drive. In these simulations, they use electron cyclotron heating, ion cyclotron heating, and electron cyclotron and fast wave current drive. The ability to maintain the profiles is demonstrated using several energy transport models. Self-consistent transport simulations are used to model the SSC discharges using the ONETWO transport code coupled to rf heating and current drive packages FASTWAVE and TORAY. To accurately model inductive and driven current profile evolution, the additional source terms that arise in Faraday's law due to internal flux surface motion are included by coupling the transport calculations to a fixed boundary equilibrium code. To test the sensitivity of the results to the transport model used, they model DIII-D discharges using thermal conductivities consistent with improved confinement DIII-D discharges, and with the Rebut-Lallia-Watkins model of energy transport

  13. Laboratory Experimental System for Examination of Acoustic Emission Generated by Partial Discharges

    Directory of Open Access Journals (Sweden)

    I. M. Salom

    2013-11-01

    Full Text Available One of the major causes of transformer failures is dielectric breakdown. Partial discharges cause gradual insulation degradation thus partial discharge activity monitoring provides transformer state insight. This paper gives an overview of common methods for partial discharges detection and source location in transformers, with a special reference to the acoustic method as an noninvasive and interference resistant method suitable for application. For laboratory testing a laboratory experimental system for partial discharge diagnostics using acoustic emission measurement was developed.

  14. Radioactive Ion Sources

    CERN Document Server

    Stora, T

    2013-01-01

    This chapter provides an overview of the basic requirements for ion sources designed and operated in radioactive ion beam facilities. The facilities where these sources are operated exploit the isotope separation online (ISOL) technique, in which a target is combined with an ion source to maximize the secondary beam intensity and chemical element selectivity. Three main classes of sources are operated, namely surface-type ion sources, arc discharge-type ion sources, and finally radio-frequency-heated plasma-type ion sources.

  15. 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.

  16. Power supply instrumentation for pulsed dielectric barrier discharges

    International Nuclear Information System (INIS)

    Quiroz Velázquez, V E; López Callejas, R; De la Piedad Beneitez, A; Rodríguez Méndez, B G; Peña Eguiluz, R; Muñoz Castro, A E; Barocio, S R; Mercado Cabrera, A; Valencia Alvarado, R

    2012-01-01

    The design and implementation of a pulsed high voltage supply intended to the production and control of pulsed dielectric barrier discharges are reported. The instrumentation includes three independently built DC sources coupled to Flyback-like converters using three 1:50 high voltage transformers. The system is capable of supplying voltages up to 70 kV at a 100-2000 Hz repetition rate, delivering 1-500 μs wide pulses. The system has been applied to the development of pulsed dielectric barrier discharges in a stainless steel coaxial reactor 30 cm long and with a 2.54 cm diameter. The inner nickel electrode diameter is 0.005 cm and is embedded in alumina. The discharges have been carried out in room pressure air. Discharges have been implemented. The discharge is made is a water environment for purposes of bacterial elimination.

  17. Investigations of low qa discharges in the SINP tokamak

    International Nuclear Information System (INIS)

    Lahiri, S.; Iyengar, A.N.S.; Mukhopadhyay, S.; Pal, R.

    2002-01-01

    Low edge safety factor discharges including very low q a (1 a a (0 a qa , τ R etc have been obtained using a set of soft wares developed at SINP. From fluctuation analysis of the external magnetic probe data it has been found that MHD instabilities m = 1, n = 1 and m = 2, n = 1 etc. play major role in the evolution of these discharges. To investigate the internal details of these discharges, an internal magnetic probe system has been developed using which current density j θ and other related parameters have been estimated. By carrying out a resistive stability analysis, evidence of the above-mentioned MHD instabilities have again been found. The physical processes lying behind the accessibility and evolution of the low q a discharges have been thoroughly investigated. (author)

  18. Modeling a short dc discharge with thermionic cathode and auxiliary anode

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanov, E. [St. Petersburg State University, St. Petersburg 199034 (Russian Federation); University ITMO, Kronverkskiy pr. 49, St. Petersburg 197101 (Russian Federation); Demidov, V. I. [St. Petersburg State University, St. Petersburg 199034 (Russian Federation); West Virginia University, Morgantown, West Virginia 26506 (United States); Kaganovich, I. D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Koepke, M. E. [West Virginia University, Morgantown, West Virginia 26506 (United States); Kudryavtsev, A. A. [St. Petersburg State University, St. Petersburg 199034 (Russian Federation)

    2013-10-15

    A short dc discharge with a thermionic cathode can be used as a current and voltage stabilizer, but is subject to current oscillation. If instead of one anode two anodes are used, the current oscillations can be reduced. We have developed a kinetic model of such a discharge with two anodes, where the primary anode has a small opening for passing a fraction of the discharge current to an auxiliary anode. The model demonstrates that the current-voltage relationship of the discharge with two anodes is characterized everywhere by positive slope, i.e., positive differential resistance. Therefore, the discharge with two anodes is expected to be stable to the spontaneous oscillation in current that is induced by negative differential resistance. As a result, such a discharge can be used in an engineering application that requires stable plasma, such as a current and voltage stabilizer.

  19. Stability-transport modeling of the SINP tokamak discharges

    Indian Academy of Sciences (India)

    Explicit finite-difference methods have been used to follow the temporal evolution of the electron temperature equation. The poloidal field diffusion equation has been solved at every time step. The effects of MHD instabilities have been incorporated by solving equations for MHD mixing and tearing modes as and when ...

  20. H- source developments

    International Nuclear Information System (INIS)

    Allison, P.W.

    1978-01-01

    The design and operation of a Penning discharge, cold cathode, surface plasma H - ion source are described. A high current density, about 2 A/cm 2 , is extracted from the source by putting about 20 keV across the 2 to 2 1 / 2 mm gap

  1. The influence of preparation method, nitrogen source, and post-treatment on the photocatalytic activity and stability of N-doped TiO2 nanopowder.

    Science.gov (United States)

    Hu, Shaozheng; Li, Fayun; Fan, Zhiping

    2011-11-30

    NH(3) plasma, N(2) plasma, and annealing in flowing NH(3) were used to prepare N doped TiO(2), respectively. XRD, UV-vis spectroscopy, N(2) adsorption, FT-IR, Zeta-potential measurement, and XP spectra were used to characterize the prepared TiO(2) samples. The nitridation procedure did not change the phase composition and particle sizes of TiO(2) samples, but extended its absorption edges to the visible light region. The photocatalytic activities were tested in the degradation of an aqueous solution of a reactive dyestuff, methylene blue, under visible light. The photocatalytic activity and stability of TiO(2) prepared by NH(3) plasma were much higher than that of samples prepared by other nitridation procedures. The visible light activity of the prepared N doped TiO(2) was improved by increasing the lattice-nitrogen content and decreasing adsorbed NH(3) on catalyst surface. The lattice-nitrogen stability of N-doped TiO(2) samples improved after HCl solution washing. The possible mechanism for the photocatalysis was proposed. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Charge Management in LISA Pathfinder: The Continuous Discharging Experiment

    Science.gov (United States)

    Ewing, Becca Elizabeth

    2018-01-01

    Test mass charging is a significant source of excess force and force noise in LISA Pathfinder (LPF). The planned design scheme for mitigation of charge induced force noise in LISA is a continuous discharge by UV light illumination. We report on analysis of a charge management experiment on-board LPF conducted during December 2016. We discuss the measurement of test mass charging noise with and without continuous UV illumination, in addition to the dynamic response in the continuous discharge scheme. Results of the continuous discharge system will be discussed for their application to operating LISA with lower test mass charge.

  3. All solid state pulsed power system for water discharge

    OpenAIRE

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

    2005-01-01

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

  4. Submarine Groundwater Discharge in the Coastal Zone

    Science.gov (United States)

    Bakti, Hendra

    2018-02-01

    Indonesia is one of the archipelagic countries that has the longest coastline in the world. Because it is located in the tropics, in general it has a very high rainfall. Each island has a different morphology which is composed of a variety of rocks with different hydrogeological properties. This natural condition allows for the presence of groundwater in different amount in each island. The difference in groundwater hydraulics gradients in aquifer continuous to the sea has triggered the discharge of groundwater to offshore known as submarine groundwater discharge (SGD). Its presence can be as seepage or submarine springs with components derived from land and sea and a mixture between them. The understanding of SGD phenomenon is very important because it can be useful as a source of clean water in coastal areas, affecting marine health, and improving marine environment.

  5. ICP Reactor Modeling: CF4 Discharge

    Science.gov (United States)

    Bose, Deepak; Govindan, T. R.; Meyyappan, M.

    1999-01-01

    Inductively coupled plasma (ICP) reactors are widely used now for etching and deposition applications due to their simpler design compared to other high density sources. Plasma reactor modeling has been playing an important role since it can, in principle, reduce the number of trial and error iterations in the design process and provide valuable understanding of mechanisms. Fluorocarbon precursors have been the choice for oxide etching. We have data available on CF4 from our laboratory. These are current voltage characteristics, La.ngmuir probe data, UV-absorption, and mass spectrometry measurements in a GEC-ICP reactor. We have developed a comprehensive model for ICP reactors which couples plasma generation and transport and neutral species dynamics with the gas flow equations. The model has been verified by comparison with experimental results for a nitrogen discharge in an ICP reactor. In the present work, the model has been applied to CF4 discharge and compared to available experimental data.

  6. Deep-water seamounts in the NE Atlantic, sources of landslides-induced tsunamis: Slope stability analysis and tsunami numerical modelling

    Science.gov (United States)

    Baptista, M. A.; Omira, R.; Ramalho, I.; Vales, D.; Matias, L. M.; Terrinha, P.

    2015-12-01

    Submarine mass failures (SMFs) present one of the significant marine Geo-hazards. Their importance as contributors to tsunami hazard has been recognized over the last 20-30 years, but they are seldom considered in the evaluation of quantitative tsunami impact or in the design of warning strategies. This study aims to investigate the slope stability of the SMFs in the NE Atlantic, their companion tsunami and the associated hazard at the target coasts. It focuses on two major deep-water seamounts of the NE Atlantic, the Gorringe Bank and the Hirondelle, where evidences of large SMFs have been found. Slope stability analysis is often based on relationships between landslides and earthquakes. Here, within each considered seamount, slope failure potential is investigated through the pseudo-static method. This analysis allows establishing a relationship between the size of the SMF and the critical earthquake peak ground acceleration necessary to initiate it and therefore define the possible SMF scenarios. Numerical modelling of SMF-induced tsunami generation is then employed to test the tsunamigenic potential of each defined scenario. It is performed using a multi-layers viscous shallow-water model, where the lower layer represents the deformable slide that is assumed to be a viscous-incompressible fluid, and bounded by the upper layer of seawater assumed to be inviscid and incompressible. The propagation of tsunami waves is simulated employing non-linear shallow water equations. Results are presented in terms of: 1) slope stability curves that establish the relationship between the probable earthquake magnitudes and the possible sizes of SMFs, 2) possible SMF scenarios within each seamount, 3) potential of tsunami generation for each SMF, 4) tsunami coastal impact at target coasts. Results show that SMFs in the NE Atlantic have the potential of generating large tsunamis with significant impact along the surrounding coasts. Therefore, more attention must be accorded to

  7. Oxidation of SO2 by stabilized Criegee intermediate (sCI radicals as a crucial source for atmospheric sulfuric acid concentrations

    Directory of Open Access Journals (Sweden)

    M. Boy

    2013-04-01

    Full Text Available The effect of increased reaction rates of stabilized Criegee intermediates (sCIs with SO2 to produce sulfuric acid is investigated using data from two different locations, SMEAR II, Hyytiälä, Finland, and Hohenpeissenberg, Germany. Results from MALTE, a zero-dimensional model, show that using previous values for the rate coefficients of sCI + SO2, the model underestimates gas phase H2SO4 by up to a factor of two when compared to measurements. Using the rate coefficients recently calculated by Mauldin et al. (2012 increases sulfuric acid by 30–40%. Increasing the rate coefficient for formaldehyde oxide (CH2OO with SO2 according to the values recommended by Welz et al. (2012 increases the H2SO4 yield by 3–6%. Taken together, these increases lead to the conclusion that, depending on their concentrations, the reaction of stabilized Criegee intermediates with SO2 could contribute as much as 33–46% to atmospheric sulfuric acid gas phase concentrations at ground level. Using the SMEAR II data, results from SOSA, a one-dimensional model, show that the contribution from sCI reactions to sulfuric acid production is most important in the canopy, where the concentrations of organic compounds are the highest, but can have significant effects on sulfuric acid concentrations up to 100 m. The recent findings that the reaction of sCI + SO2 is much faster than previously thought together with these results show that the inclusion of this new oxidation mechanism could be crucial in regional as well as global models.

  8. 76 FR 68750 - Final National Pollutant Discharge Elimination System (NPDES) Pesticide General Permit for Point...

    Science.gov (United States)

    2011-11-07

    ... regulation that excluded discharges of biological pesticides and chemical pesticides that leave a residue.... 2009). The Court held that the CWA unambiguously includes ``biological pesticides,'' and ``chemical... pesticides is from a point source. Thus, point source discharges of biological pesticides and chemical...

  9. The ASDEX Upgrade discharge schedule

    International Nuclear Information System (INIS)

    Neu, G.; Engelhardt, K.; Raupp, G.; Treutterer, W.; Zasche, D.; Zehetbauer, T.

    2007-01-01

    ASDEX Upgrade's recently commissioned discharge control system (DCS) marks the transition from a traditional programmed system to a highly flexible 'data driven' one. The allocation of application processes (APs) to controllers, the interconnection of APs through uniquely named signals, and AP control parameter values are all defined as data, and can easily be adapted to the requirements of a particular discharge. The data is laid down in a set of XML documents which APs request via HTTP from a configuration server before a discharge. The use of XML allows for easy parsing, and structural validation through (XSD) schemas. The central input to the configuration process is the discharge schedule (DS), which embodies the dynamic behaviour of a planned discharge as reference trajectories grouped in segments, concatenated through transition conditions. Editing, generation and validation tools, and version control through CVS allow for efficient management of DSs

  10. Recurrent vaginal discharge in children.

    Science.gov (United States)

    McGreal, Sharon; Wood, Paul

    2013-08-01

    Childhood vaginal discharge remains a frequent reason for referral from primary to secondary care. The Pediatric and Adolescent Gynecology (PAG) service at Kettering General Hospital was established in 1993 and provides a specialized service that meets the needs of children with gynaecological conditions. To investigate recurrent vaginal discharge noting symptomatology, defining pathogens, common and rarer causes, exploring management regimes, and any changes in practice over time. Retrospective review spanning 15 years identifying prepubertal children attending the outpatient PAG clinic with recurrent vaginal discharge. We reviewed the medical notes individually. 110 patients were identified; 85% were referred from primary care. The age distribution was bimodal at four and eight years. Thirty-five percent of our patients were discharged after the initial consultation. The commonest cause of discharge was vulvovaginitis (82%). Other important causes included suspected sexual abuse (5%), foreign body (3%), labial adhesions (3%), vaginal agenesis (2%). 35% of patients were admitted for vaginoscopy. Vaginal discharge is the most common gynecological symptom in prepubertal girls and can cause repeated clinical episodes. Vulvovaginitis is the most common cause and often responds to simple hygiene measures. Awareness of the less common causes of vaginal discharge is essential. Copyright © 2013 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  11. High efficiency atomic hydrogen source

    International Nuclear Information System (INIS)

    Lagomarsino, V.; Bassi, D.; Bertok, E.; De Paz, M.; Tommasini, F.

    1974-01-01

    This work presents preliminary results of research intended to produce a M.W. discharge atomic hydrogen source with good dissociation at pressures larger than 10 torr. Analysis of the recombination process at these pressures shows that the volume recombination by three body collisions may be more important than wall recombination or loss of atoms by diffusion and flow outside the discharge region

  12. Legal aspects of thermal discharges

    International Nuclear Information System (INIS)

    Martin, A.J.

    1974-01-01

    An overview of those legal areas which directly affect technical and planning decisions is presented in the form of 2 legal approaches which constrain the indiscriminate release of thermal discharges to receiving waters. One takes the form of private remedies which have traditionally been available to aggrieved parties who are in some way damaged by the harmful discharge. The 2nd approach utilizes the various statutory constraints leading to direct governmental action. It appears that statutory law is playing the prominent role in restricting the temperature to which receiving waters may be raised as a result of such discharges by using effluent limitations and water quality standards. (Water Resour. Abstr.)

  13. An introduction to gas discharges

    CERN Document Server

    Howatson, A M

    2013-01-01

    An Introduction to Gas Discharges: Second Edition aims to provide a compact introduction to the subject of gas discharges, which continues to make both scientific and industrial progress. In this second edition, the author has made minor corrections, rewritten and expanded some sections, used SI units and modernized notions, in hopes of making the book more up to date. Included in the book is a short history of the subject, an introduction that enumerates the types of gas discharges, the fundamental processes, and then moves on to the more specific areas such as the breakdown, the self-sustai

  14. Foundations of DC plasma sources

    Science.gov (United States)

    Tomas Gudmundsson, Jon; Hecimovic, Ante

    2017-12-01

    A typical dc discharge is configured with the negative cathode at one end and a positive anode at the other end, separated by a gas filled gap, placed inside a long glass cylinder. A few hundred volts between the cathode and anode is required to maintain the discharge. The type of discharge that is formed between the two electrodes depends upon the pressure of the working gas, the nature of the working gas, the applied voltage and the geometry of the discharge. We discuss the current–voltage characteristics of the discharge as well as the distinct structure that develops in the glow discharge region. The dc glow discharge appears in the discharge current range from μA to mA at 0.5–300 Pa pressure. We discuss the various phenomena observed in the dc glow discharge, including the cathode region, the positive column, and striations. The dc glow discharge is maintained by the emission of secondary electrons from the cathode target due to the bombardment of ions. For decades, the dc glow discharge has been used as a sputter source. Then it is often operated as an obstructed abnormal glow discharge and the required applied voltage is in the range 2–5 kV. Typically, the cathode target (the material to be deposited) is connected to a negative voltage supply (dc or rf) and the substrate holder faces the target. The relatively high operating pressure, in the range from 2 to 4 Pa, high applied voltages, and the necessity to have a conductive target limit the application of dc glow discharge as a sputter source. In order to lower the discharge voltage and expand the operation pressure range, the lifetime of the electrons in target vicinity is increased through applying magnetic field, by adding permanent magnets behind the cathode target. This arrangement is coined the magnetron sputtering discharge. The various configurations of the magnetron sputtering discharge and its applications are described. Furthermore, the use of dc discharges for chemical analysis, the

  15. Numerical simulation of compact intracloud discharge and generated electromagnetic pulse

    Science.gov (United States)

    Babich, L. P.; Bochkov, E. I.; Kutsyk, I. M.

    2015-06-01

    Using the concept of the relativistic runaway electron avalanche, numerical simulation of compact intracloud discharge as a generator of powerful natural electromagnetic pulses (EMPs) in the HF-UHF range was conducted. We evaluated the numbers of electrons initiating the avalanche, with which the calculated EMP characteristics are consistent with measured ones. The discharge capable of generating EMPs produces runaway electrons in numbers close to those in the source of terrestrial γ-flashes (TGF) registered in the nearest space, which may be an argument for a joint EMP and TGF source.

  16. Metal impurity release in diverted tokamak discharges

    International Nuclear Information System (INIS)

    Staudenmaier, G.; Wampler, W.R.

    1987-01-01

    Plasma-materials interaction at the wall of the main plasma chamber of the divertor tokamak ASDEX was investigated by a combined probe, allowing simultaneous measurements of the erosion rate by neutral particles, and the flux and average energy of neutrals. The erosion was measured by collecting part of the released material which was analysed subsequently by electron induced X-ray analysis. The flux and energy of the impinging neutral particles were measured after each single discharge with an energy resolving carbon resistance probe. The carbon probe is an excellent detector not only for deuterium but also for energetic neutral helium atoms. Wall sputtering by CX neutrals is the dominant iron impurity source in ohmically heated deuterium discharges. However, during discharges in helium not only CX neutral sputtering but also sputtering by helium ions is an important impurity release mechanism. But during auxiliary heating by neutral beams and radio frequency in deuterium, impurity generation by CX neutrals was found to increase with heating power. (orig.)

  17. Harwell Laboratory radioactive discharges and environmental monitoring

    International Nuclear Information System (INIS)

    1992-06-01

    This report provides information on disposal of radioactive waste from Harwell and on associated environmental monitoring for the calendar year 1991. In most instances information has also been provided on measurements made in previous years to show the 1991 results in their historical perspective. The National Radiological Protection Board, (NRPB) currently recommends a primary dose limit for individual members of the public of 1 mSv per year from sources other than natural background radiation. Operations of a single site such as Harwell should give rise to a dose of no more than 0.5 mSv per year. No member of the public is judged to have exceeded this dose as a consequence of discharges made in 1991. Throughout this report, discharge measurements have been assessed against derived limits corresponding to a dose of 0.5 mSv, consistent with NRPB advice. During the year, work was completed on the revision of both the atmospheric and liquid discharge authorisations, bringing to a close a long period of discussions between the Laboratory and the Authorising Departments (HMIP and MAFF). Draft certificates of authorisation were sent out to local public bodies for consultation in the autumn and the final certificates were in place ready for implementation on the 1st January 1992. Further details are given in the body of this report. (author)

  18. High pressure discharges in cavities formed by microfabrication techniques

    International Nuclear Information System (INIS)

    Khan, B.A.; Cammack, D.A.; Pinker, R.D.; Racz, J.

    1997-01-01

    High pressure discharges are the basis of small high intensity light sources. In this work, we demonstrate the formation of high pressure discharges, in cavities formed by applying micromachining and integrated circuit techniques to quartz substrates. Cavities containing varying amounts of mercury and argon were fabricated to obtain high pressure discharges. A high pressure mercury discharge was formed in the electrodeless cavities by exciting them with a microwave source, operating at 2.45 GHz and in the electroded cavities by applying a dc voltage. The contraction of the discharge into a high pressure arc was observed. A broad emission spectrum due to self-absorption and collisions between excited atoms and normal atoms, typical of high pressure mercury discharges, was measured. The light output and efficacy increased with increasing pressure. The measured voltage was used to estimate the pressure within the electroded cavities, which is as high as 127 atm for one of the two cavities discussed in this work. Efficacies over 40 lumens per watt were obtained for the electrodeless cavities and over 50 scr(l)m/W for the electroded cavities. copyright 1997 American Institute of Physics

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    The properties of water surface discharge plasma for variety of pulse repetition rates are investigated. A magnetic pulse compression (MPC) pulsed power modulator able to deliver pulse repetition rates up to 1000 Hz, with 0.5 J per pulse energy output at 25 kV, was used as the pulsed power source. Positive pulse with a point-to-plane electrode configuration was used for the experiments. The concentration and production yield of hydrogen peroxide (H 2 O 2 ) were quantitatively measured and orange II organic dye was treated, to evaluate the chemical properties of the discharge reactor. Experimental results show that the physical and chemical properties of water surface discharge are not influenced by pulse repetition rate, very different from those observed for under water discharge. The production yield of H 2 O 2 and degradation rate per pulse of the dye did not significantly vary at different pulse repetition rates under a constant discharge mode on water surface. In addition, the solution temperature, pH, and conductivity for both water surface and underwater discharge reactors were measured to compare their plasma properties for different pulse repetition rates. The results confirm that surface discharge can be employed at high pulse repetition rates as a reliable and advantageous method for industrial and environmental decontamination applications.

  20. Parameters for Fabricating Nano-Au Colloids through the Electric Spark Discharge Method with Micro-Electrical Discharge Machining.

    Science.gov (United States)

    Tseng, Kuo-Hsiung; Chung, Meng-Yun; Chang, Chaur-Yang

    2017-06-02

    In this study, the Electric Spark Discharge Method (ESDM) was employed with micro-electrical discharge machining (m-EDM) to create an electric arc that melted two electrodes in deionized water (DW) and fabricated nano-Au colloids through pulse discharges with a controlled on-off duration (T ON -T OFF ) and a total fabrication time of 1 min. A total of six on-off settings were tested under normal experimental conditions and without the addition of any chemical substances. Ultraviolet-visible spectroscopy (UV-Vis), Zetasizer Nano measurements, and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) analyses suggested that the nano-Au colloid fabricated at 10-10 µs (10 µs on, 10 µs off) had higher concentration and suspension stability than products made at other T ON -T OFF settings. The surface plasmon resonance (SPR) of the colloid was 549 nm on the first day of fabrication and stabilized at 532 nm on the third day. As the T ON -T OFF period increased, the absorbance (i.e., concentration) of all nano-Au colloids decreased. Absorbance was highest at 10-10 µs. The SPR peaks stabilized at 532 nm across all T ON -T OFF periods. The Zeta potential at 10-10 µs was -36.6 mV, indicating that no nano-Au agglomeration occurred and that the particles had high suspension stability.

  1. Numerical modelling of barrier discharge

    International Nuclear Information System (INIS)

    Kozlov, K.V.

    1990-01-01

    A survey is given of the theory of the barrier discharge in oxygen at atmospheric pressure. The discharge consists of a number of randomly distributed microdischarges of nanosecond duration. This complicated space-time structure must be taken into account in any numerical model of the barrier discharge. In a single discharge channel, three consequent phases can be distinguished; 1) electric breakdown and electron-time-scale processes; 2) ion drift and ion-time-scale processes; 3) slow chemical processes, diffusion of chemical products and heat transfer. The scheme of such a three-phase model is presented and the results of simulation are discussed and compared with experimental data. (J.U.) 9 figs., 15 refs

  2. Microwave discharges in capillary tubes

    International Nuclear Information System (INIS)

    Dervisevic, Emil

    1984-01-01

    This research thesis aims at being a contribution to the study of microwave discharge by a surface wave, and more precisely focusses on the discharge in capillary tubes filled with argon. The author first present theoretical models which describe, on the one hand, the propagation of the surface wave along the plasma column, and, on the other hand, longitudinal and radial profiles of the main discharge characteristics. The second part addresses the study of the influence of parameters (gas pressure and tube radius) on discharge operation and characteristics. Laws of similitude as well as empirical relationships between argon I and argon II emission line intensities, electron density, and electric field in the plasma have been established [fr

  3. Gram stain of urethral discharge

    Science.gov (United States)

    Urethral discharge Gram stain; Urethritis - Gram stain ... Augenbraun MH, McCormack WM. Urethritis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition . ...

  4. Discharge cell for ozone generator

    Science.gov (United States)

    Nakatsuka, Suguru

    2000-01-01

    A discharge cell for use in an ozone generator is provided which can suppress a time-related reduction in ozone concentration without adding a catalytic gas such as nitrogen gas to oxygen gas as a raw material gas. The discharge cell includes a pair of electrodes disposed in an opposed spaced relation with a discharge space therebetween, and a dielectric layer of a three-layer structure consisting of three ceramic dielectric layers successively stacked on at least one of the electrodes, wherein a first dielectric layer of the dielectric layer contacting the one electrode contains no titanium dioxide, wherein a second dielectric layer of the dielectric layer exposed to the discharge space contains titanium dioxide in a metal element ratio of not lower than 10 wt %.

  5. Total colectomy or proctocolectomy - discharge

    Science.gov (United States)

    ... Ileostomy and your diet Ileostomy - caring for your stoma Ileostomy - changing your pouch Ileostomy - discharge Ileostomy - what to ask your doctor Low-fiber diet Surgical wound care - open Types of ileostomy Review Date 9/17/ ...

  6. Preventing readmissions through comprehensive discharge planning.

    Science.gov (United States)

    Hunter, Tabitha; Nelson, James Rex; Birmingham, Jackie

    2013-01-01

    Conditions of Participation for Discharge Planning can be used not only to show compliance but as tools to evaluate current practice and identify areas of improvement. Preventable readmissions or rehospitalizations directly affect patient safety, patient outcome, hospital reimbursement, and hospital accreditation. Preventable readmissions can be controlled by comprehensive discharge planning. Case managers are directly involved in discharge planning and thus have direct accountability regarding readmissions; therefore, they must refine the admission assessment screening to include specific information based on a patient's preadmission level of care. Collaboration with community-based providers is essential to managing readmissions or rehospitalizations. Hospitals will find it beneficial to track readmissions by using specific data points unique to readmissions such as source of admission and previous length of stay. Self-assessment of compliance will help identify opportunities for quality improvement in the case management department. PLEASE NOTE: Rules and regulations are constantly changing. It is critical to monitor changes in standards. Information contained in this article is current at the time of submission, and readers are encouraged to review the content of this article with administration before implementing changes.

  7. Multipactor Discharge on Metal and Dielectric Surfaces

    Science.gov (United States)

    Kishek, R. A.

    1997-11-01

    Multipactor is a recurrent rf breakdown phenomenon based on secondary electron emission. It occurs in a wide range of devices when the electron trajectories due to the applied rf are resonant with structures such as accelerators, coherent radiation sources, satellites, and ECRH/ICRH antennas. A simple model is used to study the temporal evolution of a first-order, two-surface multipactor discharge and its interaction with the surrounding rf structure. The loading of the structure by the changing multipactor current, a combination of de-tuning and of reducing the quality factor of the resonant structure, is found to cause saturation. A novel phase focusing mechanism is discovered in which the electrostatic repulsion among the space charge may result in the multipactor electrons being very tightly bunched. The theory predicts the parameter range over which a steady-state, 2-surface multipactor may occur, linking material properties to the dynamics of the discharge(R. A. Kishek, Y. Y. Lau, and D. Chernin, Phys. Plasmas 4, 863 (1997).). The analytic theory is in excellent agreement with the computational results of the model and is applied to documented experimental observations of multipactor. On a dielectric (such as an rf window), multipactor poses a different kind of problem. Charge accumulation on the dielectric sets up a DC electric field which affects the dynamics of the discharge. Monte Carlo simulations are used to construct susceptibility diagrams for a wide range of materials that will allow an immediate assessment of the range of rf power over which multipactor may be expected to occur.

  8. Sources for charged particles

    International Nuclear Information System (INIS)

    Arianer, J.

    1997-01-01

    This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.)

  9. Radioactive discharges from Sellafield (UK)

    International Nuclear Information System (INIS)

    Pentreath, R.J.

    1985-01-01

    This study of low-level liquid radioactive discharges from the British Nuclear Fuels Ltd Sellafield site into the eastern basin of the Irish Sea, prepared on the basis of existing publications and documents, reviews chemical forms and rate of discharges, physical oceanography, sediment distribution and fisheries of the Irish Sea, behaviour of radionuclides in seawater, association with sedimentary materials, accumulation of radionuclides by biological materials, environmental monitoring, surveillance and assessment of radiation exposure of the public and impact on the environment

  10. Electric discharge synthesis of HCN in simulated Jovian atmospheres.

    Science.gov (United States)

    Stribling, R; Miller, S L

    1987-01-01

    HCN has been detected in the Jovian atmosphere at a column density of about 2.2 x 10(-7) moles cm-2. While photochemical synthesis from methylamine and aziridine, upwelling, and lightning have been proposed as possible sources of this HCN, corona discharge has not been previously considered. HCN energy yields (moles J-1) were measured using corona discharge for gas mixtures containing H2, CH4, NH3, with H2/CH4 ratios from 4.4 to 1585. The yields are approximately proportional to the mole fraction of methane in the gas mixture. Assuming that the 3/1 ratio of corona discharge to lightning energy on the Earth applies to Jupiter, HCN column densities from corona discharge could account for approximately 10% of the observed HCN. These estimates are very dependent on the values used for the energy available as lightning on Jupiter and the eddy diffusion coefficients in the region of synthesis.

  11. Discharging a DC bus capacitor of an electrical converter system

    Science.gov (United States)

    Kajouke, Lateef A; Perisic, Milun; Ransom, Ray M

    2014-10-14

    A system and method of discharging a bus capacitor of a bidirectional matrix converter of a vehicle are presented here. The method begins by electrically shorting the AC interface of the converter after an AC energy source is disconnected from the AC interface. The method continues by arranging a plurality of switching elements of a second energy conversion module into a discharge configuration to establish an electrical current path from a first terminal of an isolation module, through an inductive element, and to a second terminal of the isolation module. The method also modulates a plurality of switching elements of a first energy conversion module, while maintaining the discharge configuration of the second energy conversion module, to at least partially discharge a DC bus capacitor.

  12. Laser ablation/ionization studies in a glow discharge

    International Nuclear Information System (INIS)

    Hess, K.R.; Harrison, W.W.

    1985-01-01

    The pin cathode glow discharge is used in the laboratory as an atomization/ionization source for a variety of applications, including solids mass spectrometry. Coupled with a tunable dye laser, the glow discharge may also serve as an atom reservoir for resonance ionization mass spectrometry in which the laser ionizes the discharge sputtered atoms. By tightly focusing the laser onto solid samples, various ablation effects may also be investigated. The laser may be used to generate an ionized plasma which may be directly analyzed by mass spectrometry. Alternatively, the ablated neutral atoms may be used in post-ablation excitation/ionization processes, in this case the glow discharge. The results of these investigations are the basis of this paper

  13. Vaginal Discharge: What's Normal, What's Not

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Vaginal Discharge: What's Normal, What's Not KidsHealth / For Teens / Vaginal Discharge: What's Normal, What's Not Print Normal vaginal discharge ...

  14. Decision & Management Tools for DNAPL Sites: Optimization of Chlorinated Solvent Source and Plume Remediation Considering Uncertainty

    Science.gov (United States)

    2011-08-01

    ii LIST OF FIGURES Page Figure 1. Power function illustration of source mass and source discharge relationship...source model based on a power function relationship linking the source mass to the source discharge and an analytical plume model based on one...rate in the source zone. The source mass is linked to the source discharge through a power function relationship to reflect the site architecture

  15. Vessel-sourced pollution: a security threat in Malaysian waters ...

    African Journals Online (AJOL)

    Vessel-sourced pollution is one of the major sources of marine pollution and it encompasses accidental discharge of oil, intentional discharge of oil (like discharge from ballast tanks), chemicals, dumping, etc. The United Nations Convention on the Law of the Sea (UNCLOS), 1982 and some other conventions make ...

  16. The formation of diffuse discharge by short-front nanosecond voltage pulses and the modification of dielectrics in this discharge

    Science.gov (United States)

    Orlovskii, V. M.; Panarin, V. A.; Shulepov, M. A.

    2014-07-01

    The dynamics of diffuse discharge formation under the action of nanosecond voltage pulses with short fronts (below 1 ns) in the absence of a source of additional preionization and the influence of a dielectric film on this process have been studied. It is established that the diffuse discharge is induced by the avalanche multiplication of charge initiated by high-energy electrons and then maintained due to secondary breakdowns propagating via ionized gas channels. If a dielectric film (polyethylene, Lavsan, etc.) is placed on the anode, then multiply repeated discharge will lead to surface and bulk modification of the film material. Discharge-treated polyethylene film exhibits a change in the optical absorption spectrum in the near-IR range.

  17. Classification of electrical discharges in DC Accelerators

    Science.gov (United States)

    Banerjee, Srutarshi; Deb, A. K.; Rajan, Rehim N.; Kishore, N. K.

    2016-08-01

    Controlled electrical discharge aids in conditioning of the system while uncontrolled discharges damage its electronic components. DC Accelerator being a high voltage system is no exception. It is useful to classify electrical discharges according to the severity. Experimental prototypes of the accelerator discharges are developed. Photomultiplier Tubes (PMTs) are used to detect the signals from these discharges. Time and Frequency domain characteristics of the detected discharges are used to extract features. Machine Learning approaches like Fuzzy Logic, Neural Network and Least Squares Support Vector Machine (LSSVM) are employed to classify the discharges. This aids in detecting the severity of the discharges.

  18. Classification of electrical discharges in DC Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Srutarshi, E-mail: sruban.stephens@gmail.com [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Deb, A.K. [Department of Electrical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Rajan, Rehim N. [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Kishore, N.K. [Department of Electrical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2016-08-11

    Controlled electrical discharge aids in conditioning of the system while uncontrolled discharges damage its electronic components. DC Accelerator being a high voltage system is no exception. It is useful to classify electrical discharges according to the severity. Experimental prototypes of the accelerator discharges are developed. Photomultiplier Tubes (PMTs) are used to detect the signals from these discharges. Time and Frequency domain characteristics of the detected discharges are used to extract features. Machine Learning approaches like Fuzzy Logic, Neural Network and Least Squares Support Vector Machine (LSSVM) are employed to classify the discharges. This aids in detecting the severity of the discharges.

  19. A hollow cathode ion source for production of primary ions for the BNL electron beam ion source

    Science.gov (United States)

    Alessi, James; Beebe, Edward; Carlson, Charles; McCafferty, Daniel; Pikin, Alexander; Ritter, John

    2014-02-01

    A hollow cathode ion source, based on one developed at Saclay, has been modified significantly and used for several years to produce all primary 1+ ions injected into the Relativistic Heavy Ion Collider Electron Beam Ion Source (EBIS) at Brookhaven. Currents of tens to hundreds of microamperes have been produced for 1+ ions of He, C, O, Ne, Si, Ar, Ti, Fe, Cu, Kr, Xe, Ta, Au, and U. The source is very simple, relying on a glow discharge using a noble gas, between anode and a solid cathode containing the desired species. Ions of both the working gas and ionized sputtered cathode material are extracted, and then the desired species is selected using an ExB filter before being transported into the EBIS trap for charge breeding. The source operates pulsed with long life and excellent stability for most species. Reliable ignition of the discharge at low gas pressure is facilitated by the use of capacitive coupling from a simple toy plasma globe. The source design, and operating experience for the various species, is presented.

  20. Water-stabilized plasma generators

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, Milan

    1998-01-01

    Roč. 70, č. 6 (1998), s. 1157-1162 ISSN 0033-4545 R&D Projects: GA ČR GA102/95/0592; GA ČR GV106/96/K245 Institutional research plan: CEZ:AV0Z2043910 Keywords : thermal plasma, plasma torch, water -stabilized plasma Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.677, year: 1998

  1. The Spectral Statistical Method for Determining the Location Parameters of a Dipole Source of Electromagnetic Radiation

    Science.gov (United States)

    Panyukov, A. V.; Bogushov, A. K.

    2016-09-01

    Using the measured horizontal and vertical components of the magnetic and electric fields, respectively, we solve the problem of determining the location of a dipole source of electromagnetic radiation, which is equivalent to the lightning discharge, at the specified point of an infinitely conducting plane. The proposed method, which is based on the analysis of the measured-signal spectra, allows one to develop many estimates of the source location, choose the final estimate on the basis of the results of analysis of the entire totality of these estimates, and, therefore, reach stability in determining the source location. The spectral method makes it possible to obtain more stable solutions at a lower computation cost compared with the previously developed parametric extremum method. The spectral-method algorithm can be naturally parallelized. The results of the analytical and numerical studies of the accuracy and stability of the proposed method are presented.

  2. Fishbone mode in high-β discharges of spherical tokamaks

    International Nuclear Information System (INIS)

    Kolesnichenko, Ya.I.; Lutsenko, V.V.; Marchenko, V.S.

    2000-01-01

    Using Hamiltonian formalism, it has been shown that well-trapped energetic ions moving outwards consume the energy of MHD perturbations through the precessional resonance provided that the plasma pressure is sufficiently high. This supports the conclusion of recent publication that the fishbone mode is stabilized in high-β discharges of spherical tokamaks. It has also been found that the presence of the velocity anisotropy of energetic ions does not change this conclusion. (author)

  3. Estimating sediment discharge: Appendix D

    Science.gov (United States)

    Gray, John R.; Simões, Francisco J. M.

    2008-01-01

    Sediment-discharge measurements usually are available on a discrete or periodic basis. However, estimates of sediment transport often are needed for unmeasured periods, such as when daily or annual sediment-discharge values are sought, or when estimates of transport rates for unmeasured or hypothetical flows are required. Selected methods for estimating suspended-sediment, bed-load, bed- material-load, and total-load discharges have been presented in some detail elsewhere in this volume. The purposes of this contribution are to present some limitations and potential pitfalls associated with obtaining and using the requisite data and equations to estimate sediment discharges and to provide guidance for selecting appropriate estimating equations. Records of sediment discharge are derived from data collected with sufficient frequency to obtain reliable estimates for the computational interval and period. Most sediment- discharge records are computed at daily or annual intervals based on periodically collected data, although some partial records represent discrete or seasonal intervals such as those for flood periods. The method used to calculate sediment- discharge records is dependent on the types and frequency of available data. Records for suspended-sediment discharge computed by methods described by Porterfield (1972) are most prevalent, in part because measurement protocols and computational techniques are well established and because suspended sediment composes the bulk of sediment dis- charges for many rivers. Discharge records for bed load, total load, or in some cases bed-material load plus wash load are less common. Reliable estimation of sediment discharges presupposes that the data on which the estimates are based are comparable and reliable. Unfortunately, data describing a selected characteristic of sediment were not necessarily derived—collected, processed, analyzed, or interpreted—in a consistent manner. For example, bed-load data collected with

  4. Glow discharge in singlet oxygen

    International Nuclear Information System (INIS)

    Vagin, N.P.; Ionin, A.A.; Klimachev, Yu.M.; Sinitsyn, D.V.; Yuryshev, N.N.; Kochetov, I.V.; Napartovich, A.P.

    2003-01-01

    Currently, there is no experimental data on the plasma balance in gas mixtures with a high content of singlet delta oxygen O 2 ( 1 Δ g ). These data can be obtained by studying the parameters of an electric discharge in singlet oxygen produced by a chemical generator. The O 2 ( 1 Δ g ) molecules significantly change the kinetics of electrons and negative ions in plasma. Hence, the discharge conditions at low and high O 2 ( 1 Δ g ) concentrations are very different. Here, the parameters of the positive column of a glow discharge in a gas flow from a chemical singlet-oxygen generator are studied. It is experimentally shown that, at an O 2 ( 1 Δ g ) concentration of 50% and at pressures of 1.5 and 2 torr, the electric field required to sustain the discharge is considerably lower than in the case when all of the oxygen molecules are in the ground state. A theoretical model of the glow discharge is proposed whose predictions are in good agreement with the experimental data

  5. Spatial Characteristics and Driving Factors of Provincial Wastewater Discharge in China

    Directory of Open Access Journals (Sweden)

    Kunlun Chen

    2016-12-01

    Full Text Available Based on the increasing pressure on the water environment, this study aims to clarify the overall status of wastewater discharge in China, including the spatio-temporal distribution characteristics of wastewater discharge and its driving factors, so as to provide reference for developing “emission reduction” strategies in China and discuss regional sustainable development and resources environment policies. We utilized the Exploratory Spatial Data Analysis (ESDA method to analyze the characteristics of the spatio-temporal distribution of the total wastewater discharge among 31 provinces in China from 2002 to 2013. Then, we discussed about the driving factors, affected the wastewater discharge through the Logarithmic Mean Divisia Index (LMDI method and classified those driving factors. Results indicate that: (1 the total wastewater discharge steadily increased, based on the social economic development, with an average growth rate of 5.3% per year; the domestic wastewater discharge is the main source of total wastewater discharge, and the amount of domestic wastewater discharge is larger than the industrial wastewater discharge. There are many spatial differences of wastewater discharge among provinces via the ESDA method. For example, provinces with high wastewater discharge are mainly the developed coastal provinces such as Jiangsu Province and Guangdong Province. Provinces and their surrounding areas with low wastewater discharge are mainly the undeveloped ones in Northwest China; (2 The dominant factors affecting wastewater discharge are the economy and technological advance; The secondary one is the efficiency of resource utilization, which brings about the unstable effect; population plays a less important role in wastewater discharge. The dominant driving factors affecting wastewater discharge among 31 provinces are divided into three types, including two-factor dominant type, three-factor leading type and four-factor antagonistic type

  6. Deriving Global Discharge Records from SWOT Observations

    Science.gov (United States)

    Pan, M.; Fisher, C. K.; Wood, E. F.

    2017-12-01

    River flows are poorly monitored in many regions of the world, hindering our ability to accurately estimate water global water usage, and thus estimate global water and energy budgets or the variability in the global water cycle. Recent developments in satellite remote sensing, such as water surface elevations from radar altimetry or surface water extents from visible/infrared imagery, aim to fill this void; however, the streamflow estimates derived from these are inherently intermittent in both space and time. There is then a need for new methods that are able to derive spatially and temporally continuous records of discharge from the many available data sources. One particular application of this will be the Surface Water and Ocean Topography (SWOT) mission, which is designed to provide global observations of water surface elevation and slope from which river discharge can be estimated. Within the 21-day repeat cycle, a river reach will be observed 2-4 times on average. Due to the relationship between the basin orientation and the orbit, these observations are not evenly distributed in time or space. In this study, we investigate how SWOT will observe global river basins and how the temporal and spatial sampling impacts our ability to reconstruct discharge records.River flows can be estimated throughout a basin by assimilating SWOT observations using the Inverse Streamflow Routing (ISR) model of Pan and Wood [2013]. This method is applied to 32 global basins with different geometries and crossing patterns for the future orbit, assimilating theoretical SWOT-retrieved "gauges". Results show that the model is able to reconstruct basin-wide discharge from SWOT observations alone; however, the performance varies significantly across basins and is driven by the orientation, flow distance, and travel time in each, as well as the sensitivity of the reconstruction method to errors in the satellite retrieval. These properties are combined to estimate the "observability" of

  7. Discharge quenching circuit for counters

    International Nuclear Information System (INIS)

    Karasik, A.S.

    1982-01-01

    A circuit for quenching discharges in gas-discharge detectors with working voltage of 3-5 kV based on transistors operating in the avalanche mode is described. The quenching circuit consists of a coordinating emitter follower, amplifier-shaper for avalanche key cascade control which changes potential on the counter electrodes and a shaper of discharge quenching duration. The emitter follower is assembled according to a widely used flowsheet with two transistors. The circuit permits to obtain a rectangular quenching pulse with front of 100 ns and an amplitude of up to 3.2 kV at duration of 500 μm-8 ms. Application of the quenching circuit described permits to obtain countering characteristics with the slope less than or equal to 0.02%/V and plateau extent greater than or equal to 300 V [ru

  8. State Waste Discharge Permit application, 183-N Backwash Discharge Pond

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations (Ecology et al. 1994), the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173--216 (or 173--218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order No. DE91NM-177, (Ecology and DOE-RL 1991). The Consent Order No. DE91NM-177 requires a series of permitting activities for liquid effluent discharges. Liquid effluents on the Hanford Site have been classified as Phase I, Phase II, and Miscellaneous Streams. The Consent Order No. DE91NM-177 establishes milestones for State Waste Discharge Permit application submittals for all Phase I and Phase II streams, as well as the following 11 Miscellaneous Streams as identified in Table 4 of the Consent Order No. DE91NM-177.

  9. Length of stay after vaginal birth: sociodemographic and readiness-for-discharge factors.

    Science.gov (United States)

    Weiss, Marianne; Ryan, Polly; Lokken, Lisa; Nelson, Magdalen

    2004-06-01

    The impact of reductions in postpartum length of stay have been widely reported, but factors influencing length of hospital stay after vaginal birth have received less attention. The study purpose was to compare the sociodemographic characteristics and readiness for discharge of new mothers and their newborns at 3 discharge time intervals, and to determine which variables were associated with postpartum length of stay. The study sample comprised 1,192 mothers who were discharged within 2 postpartum days after uncomplicated vaginal birth at a tertiary perinatal center in the midwestern United States. The sample was divided into 3 postpartum length-of-stay groups: group 1 (18-30 hr), group 2 (31-42 hr), and group 3 (43-54 hr). Sociodemographic and readiness-for-discharge data were collected by self-report and from a computerized hospital information system. Measures of readiness for discharge included perceived readiness (single item and Readiness for Discharge After Birth Scale), documented maternal and neonatal clinical problems, and feeding method. Compared with other groups, the longest length-of-stay group was older; of higher socioeconomic status and education; and with more primiparous, breastfeeding, white, married mothers who were living with the baby's father, had adequate home help, and had a private payor source. This group also reported greater readiness for discharge, but their newborns had more documented clinical problems during the postbirth hospitalization. In logistic regression modeling, earlier discharge was associated with young age, multiparity, public payor source, low socioeconomic status, lack of readiness for discharge, bottle-feeding, and absence of a neonatal clinical problem. Sociodemographic characteristics and readiness for discharge (clinical and perceived) were associated with length of postpartum hospital stay. Length of stay is an outcome of a complex interface between patient, provider, and payor influences on discharge timing

  10. Modeling Atmospheric Electromagnetic Field Following a Lightning Discharge

    Science.gov (United States)

    Davydenko, S.; Mareev, E.; Sergeev, A. S.

    2013-12-01

    A numerical model describing the electromagnetic field in the vicinity of an isolated lightning discharge is developed. Both the slow transient (quasistatic) electric field caused by the Maxwell relaxation of the charge disturbance and fast transient (electromagnetic pulse) are calculated in a plane atmosphere using the FDTD method. The lightning discharge is presented as a pulse current producing a distributed charge dipole inside the thundercloud in a case of intra-cloud (IC) flash or monopole charge in a case of cloud-to-ground (CG) flash. A temporal profile of the discharge current implies an existence of the return stroke, continuous current, and its fine features like the M-component. Temporal and spatial dependences of the atmospheric electric field on the flash type (IC or CG), distance to the discharge, disturbance of the electric conductivity inside the thundercloud, altitude(s) and lateral scale(s) of the charge region(s), temporal profile of the discharge current, and velocity of the return stroke are considered. A dependence of the net electric charge transferred to the upper atmospheric layers on the parameters of IC and CG flashes is studied. It is shown that both IC and CG flashes could serve as effective sources in the global electric circuit. A retrieval of the basic discharge parameters on the results of the one- or multipoint measurements of the both electromagnetic and quasistatic electric fields is discussed.

  11. Electric probe data analysis for glow discharge diagnostics

    International Nuclear Information System (INIS)

    Cain, B.L.

    1987-01-01

    This report summarizes the development and application of digital computations for the analysis of data from an electric probe used for glow discharge diagnostics. The essential physics of the probe/discharge interaction is presented, along with formulations from modern electric probe theory. These results are then digitally implemented by a set of computer programs which both calculate discharge properties of electron temperature and density, and aid in the interpretation of these property estimates. The method of analysis, and the theories selected for implementation, are valid only for low pressure, collisionless sheath, and quiescent discharges where the single electric probe has a much smaller area than the discharge reference electrode. However, certain algorithms are included which, in some cases, can extend the analysis into intermediate pressure regimes. The digital programs' functional capabilities are demonstrated by the analysis of experimental probe data, collected using a laboratory glow discharge. Typical sources of error inherent in the electric probe method are discussed, along with an analysis of error induced by the computational methods of the programs. 27 refs., 49 figs., 20 tabs

  12. High Current, High Density Arc Plasma as a New Source for WiPAL

    Science.gov (United States)

    Waleffe, Roger; Endrizzi, Doug; Myers, Rachel; Wallace, John; Clark, Mike; Forest, Cary; WiPAL Team

    2016-10-01

    The Wisconsin Plasma Astrophysics Lab (WiPAL) has installed a new array of nineteen plasma sources (plasma guns) on its 3 m diameter, spherical vacuum vessel. Each gun is a cylindrical, molybdenum, washer-stabilized, arc plasma source. During discharge, the guns are maintained at 1.2 kA across 100 V for 10 ms by the gun power supply establishing a high density plasma. Each plasma source is fired independently allowing for adjustable plasma parameters, with densities varying between 1018 -1019 m-3 and electron temperatures of 5-15 eV. Measurements were characterized using a 16 tip Langmuir probe. The plasma source will be used as a background plasma for the magnetized coaxial plasma gun (MCPG), the Terrestrial Reconnection Experiment (TREX), and as the plasma source for a magnetic mirror experiment. Temperature, density, and confinement results will be presented. This work is supported by the DoE and the NSF.

  13. Dynamic of ozone formation in nanosecond microwave discharges

    International Nuclear Information System (INIS)

    Akhmedzhanov, R.A.; Vikharev, A.L.; Gorbachev, A.M.

    1995-01-01

    Nanosecond gas discharges are efficient sources of chemically active plasma. Studies of the nanosecond microwave discharge are interesting for remote modification of the chemical composition of the atmosphere in term of its purification, for diagnostics of impurities and ozone replenishment in the regions of local open-quotes ozone holesclose quotes. In this connection a study of plasma chemical processes in such a discharge seems appropriate, as well as modeling of ecological consequences of the effect of powerful microwave radiation on the atmosphere. The present paper contains generalized results of studying the process of ozone formation in a pulse-periodic freely localized nanosecond microwave discharge. The experiments were performed in a wide range of parameters: microwave radiation wavelength λ = 0.8 and 3cm, pulse duration τ = 6 and 500ns, pulse power P = 50kW and 20MW, pulse repetition rate F = 1-10 3 Hz. The working gases were air and oxygen under pressure P = 10-100Torr. As a source of the microwave radiation a pulse magnetron was used with a device for pulse compression based on the waveguide resonator, and a relativistic microwave generator. The discharge was produced in the focus of the parabolic mirror and had the form of homogeneous cylinder. The plasma chemical processes were studied in two cases. The discharge was created either in the quartz tube placed along the focal line of the mirror or in the free air. Dynamics of formation of ozone and nitrogen oxides in the discharge was studied by means of absorption spectroscopy in the regime of accumulation of the products of chemical reactions (in a closed volume) and their diffusion spreading

  14. Dynamic of ozone formation in nanosecond microwave discharge

    Energy Technology Data Exchange (ETDEWEB)

    Akhmedzhanov, R.A.; Vikharev, A.L.; Gorbachev, A.M. [Inst. of Applied Physics, Novgorod (Russian Federation)] [and others

    1995-12-31

    Nanosecond gas discharges are efficient sources of chemically active plasma. Studies of the nanosecond microwave discharge are interesting for remote modification of the chemical composition of the atmosphere in term of its purification, for diagnostics of impurities and ozone replenishment in the regions of local {open_quotes}ozone holes{close_quotes}. In this connection a study of plasma chemical processes in such a discharge seems appropriate, as well as modeling of ecological consequences of the effect of powerful microwave radiation on the atmosphere. The present paper contains generalized results of studying the process of ozone formation in a pulse-periodic freely localized nanosecond microwave discharge. The experiments were performed in a wide range of parameters: microwave radiation wavelength {Lambda} = 0.8 and 3cm, pulse duration {tau} = 6 and 500ns, pulse power P = 50kW and 20MW, pulse repetition rate F = 1-10{sup 3} Hz. The working gases were air and oxygen under pressure p = 10-100Torr. As a source of the microwave radiation a pulse magnetron was used with a device for pulse compression based on the waveguide resonator, and a relativistic microwave generator. The discharge was produced in the focus of the parabolic mirror and had the form of homogeneous cylinder. The plasma chemical processes were studied in two cases. The discharge was created either in the quartz tube placed along the focal line of the mirror or in the free air. Dynamics of formation of ozone and nitrogen oxides in the discharge was studied by means of absorption spectroscopy in the regime of accumulation of the products of chemical reactions in a closed volume and in case of their diffusion spreading.

  15. Dynamic of ozone formation in nanosecond microwave discharges

    Energy Technology Data Exchange (ETDEWEB)

    Akhmedzhanov, R.A.; Vikharev, A.L.; Gorbachev, A.M. [Inst. of Applied Physics, Nizhny Novgorod (Russian Federation)] [and others

    1995-12-31

    Nanosecond gas discharges are efficient sources of chemically active plasma. Studies of the nanosecond microwave discharge are interesting for remote modification of the chemical composition of the atmosphere in term of its purification, for diagnostics of impurities and ozone replenishment in the regions of local {open_quotes}ozone holes{close_quotes}. In this connection a study of plasma chemical processes in such a discharge seems appropriate, as well as modeling of ecological consequences of the effect of powerful microwave radiation on the atmosphere. The present paper contains generalized results of studying the process of ozone formation in a pulse-periodic freely localized nanosecond microwave discharge. The experiments were performed in a wide range of parameters: microwave radiation wavelength {lambda} = 0.8 and 3cm, pulse duration {tau} = 6 and 500ns, pulse power P = 50kW and 20MW, pulse repetition rate F = 1-10{sup 3} Hz. The working gases were air and oxygen under pressure P = 10-100Torr. As a source of the microwave radiation a pulse magnetron was used with a device for pulse compression based on the waveguide resonator, and a relativistic microwave generator. The discharge was produced in the focus of the parabolic mirror and had the form of homogeneous cylinder. The plasma chemical processes were studied in two cases. The discharge was created either in the quartz tube placed along the focal line of the mirror or in the free air. Dynamics of formation of ozone and nitrogen oxides in the discharge was studied by means of absorption spectroscopy in the regime of accumulation of the products of chemical reactions (in a closed volume) and their diffusion spreading.

  16. Pinching Capillary Discharge as a Water Window Radiation Source

    Czech Academy of Sciences Publication Activity Database

    Vrba, Pavel; Zakharov, S.V.; Jančárek, A.; Vrbová, M.; Nevrkla, M.; Kolař, P.

    2011-01-01

    Roč. 184, 3-6 (2011), s. 335-337 ISSN 0368-2048. [The 37th International Conference on Vacuum Ultraviolet and X-ray Physics (VUVX2010). Vancouver, 11.07.2010-16.07.2010] R&D Projects: GA MŠk LA08024 Institutional research plan: CEZ:AV0Z20430508 Keywords : Capillary Z-pinch * water window radiation * soft x-ray spectral diagnostics * RHMD Z* engine Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.958, year: 2011 http://www.sciencedirect.com/science/article/pii/S0368204810002847

  17. Characteristics of shunting arc discharge for carbon ion source

    International Nuclear Information System (INIS)

    Takaki, K.; Mukaigawa, S.; Fujiwara, T.; Kumagai, M.; Yukimura, K.

    2003-01-01

    The criteria of initial resistance of carbon rod for shunting arc ignition are described in this article. The five different resistances were used. The rods are 40 mm in length and 2 mm in diameter. The carbon rod was set in the vacuum and was initially heated up with a pulsed current supplied by a charged capacitor with a capacitance of 20 μF, followed by a self-ignition. The heating energy is almost independent of the charging voltage of the capacitor. The heating energy increases with decreasing the rod resistance, whereas the energy deposited in the plasma and the utilizing efficiency of the charged energy in the capacitor decreases

  18. Study of glow discharge positive column with cloud of disperse particles

    International Nuclear Information System (INIS)

    Polyakov, D.N.; Shumova, V.V.; Vasilyak, L.M.; Fortov, V.E.

    2011-01-01

    The study aims to describe plasma parameters changes induced by clouds of disperse micron size particles. Dust clouds were formed in the positive column of glow discharge in air at pressure 0.1-0.6 torr and current 0.1-3 mA. The simultaneous registration of discharge voltage and dust cloud parameters was carried out. Experimental results were simulated using diffusion model. The dust cloud is shown to smooth the radial electron concentration profile, increase electric field strength and electron temperature and stabilize the discharge. The cloud is demonstrated to be a trap for positive ions without increase of discharge current. -- Highlights: → 25% increase of longitudinal electric field strength in discharge with dust cloud. → The smoothing effect of dust cloud on radial electron and ion concentration profiles. → Dust cloud as a trap for positive ions without increase of discharge current. → Increase of electron temperature in discharge with dust cloud. → Increase of discharge stability in presence of dust cloud.

  19. Bedform Stability Fields for Smaller Density Ratio

    Science.gov (United States)

    Yokokawa, M.; Muraoka, S.; Murokawa, T.; Mizokami, Y.; Tsuji, A.; Kishimoto, K.; Naruse, H.

    2008-12-01

    When the fluid flow moves on the granular materials, the bed geometry, i.e., bedforms, change corresponding the flow conditions. Bedforms are the important source of information. From geological point of view, the bedforms migrate to generate the variety of sedimentary structures which can be used to reconstruct the paleo-hydraulic conditions. From the engineering point of view, bedforms have to be considered when the sediment transport and/or the bed roughness are discussed. Although there have been done numerous flume experiments both in the geology and engineering, most of the diagrams of bedform stability fields have been made using the silica materials and water, whose density ratio is about 2.65. Here we performed flume experiments for smaller density ratio, 1.5. This is aimed at examining the effect of density ratio on the bedform stability fields. Different density ratio can occur in the natural environments, such as under the hyperconcentrated flow, or on the surfaces of other planets. We performed flume experiments using the fragments of melamine resin, whose specific gravity is 1.5, and we used five kinds of size distributions. Small recirculating-flumes, 4 m in length, 0.3 or 0.4 m in depth and 0.08 m in width, in Kyoto University and Osaka Institute of Technology are used. The flume floor was laid with the material, and unidirectional flow was operated. The flow discharge was increased gradually, and bedform formation was observed. Flow discharge, flow depth, water-surface slope, and water temperature were measured. Based on these data, non-dimensional parameters, such as Mobility parameter, Particle parameter, and Froude number, were calculated and compared with those of quartz grains (Van den Berg and Van Gelder, 1993). As a result, we got bedform stability fields for the density ratio 1.5. Comparing with that of quartz grains, the following features were found. (1) The kinds of bedforms observed in these experiments were the same with those of

  20. EUV sources for the alpha-tools

    Science.gov (United States)

    Pankert, Joseph; Apetz, Rolf; Bergmann, Klaus; Damen, Marcel; Derra, Günther; Franken, Oliver; Janssen, Maurice; Jonkers, Jeroen; Klein, Jürgen; Kraus, Helmar; Krücken, Thomas; List, Andreas; Loeken, Micheal; Mader, Arnaud; Metzmacher, Christof; Neff, Willi; Probst, Sven; Prümmer, Ralph; Rosier, Oliver; Schwabe, Stefan; Seiwert, Stefan; Siemons, Guido; Vaudrevange, Dominik; Wagemann, Dirk; Weber, Achim; Zink, Peter; Zitzen, Oliver

    2006-03-01

    In this paper, we report on the recent progress of the Philips Extreme UV source. The Philips source concept is based on a discharge plasma ignited in a Sn vapor plume that is ablated by a laser pulse. Using rotating electrodes covered with a regenerating tin surface, the problems of electrode erosion and power scaling are fundamentally solved. Most of the work of the past year has been dedicated to develop a lamp system which is operating very reliably and stable under full scanner remote control. Topics addressed were the development of the scanner interface, a dose control system, thermo-mechanical design, positional stability of the source, tin handling, and many more. The resulting EUV source-the Philips NovaTin(R) source-can operate at more than 10kW electrical input power and delivers 200W in-band EUV into 2π continuously. The source is very small, so nearly 100% of the EUV radiation can be collected within etendue limits. The lamp system is fully automated and can operate unattended under full scanner remote control. 500 Million shots of continuous operation without interruption have been realized, electrode lifetime is at least 2 Billion shots. Three sources are currently being prepared, two of them will be integrated into the first EUV Alpha Demonstration tools of ASML. The debris problem was reduced to a level which is well acceptable for scanner operation. First, a considerable reduction of the Sn emission of the source has been realized. The debris mitigation system is based on a two-step concept using a foil trap based stage and a chemical cleaning stage. Both steps were improved considerably. A collector lifetime of 1 Billion shots is achieved, after this operating time a cleaning would be applied. The cleaning step has been verified to work with tolerable Sn residues. From the experimental results, a total collector lifetime of more than 10 Billion shots can be expected.

  1. 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

  2. Discharge measurements at gaging stations

    Science.gov (United States)

    Turnipseed, D. Phil; Sauer, Vernon B.

    2010-01-01

    The techniques and standards for making discharge measurements at streamflow gaging stations are described in this publication. The vertical axis rotating-element current meter, principally the Price current meter, has been traditionally used for most measurements of discharge; however, advancements in acoustic technology have led to important developments in the use of acoustic Doppler current profilers, acoustic Doppler velocimeters, and other emerging technologies for the measurement of discharge. These new instruments, based on acoustic Doppler theory, have the advantage of no moving parts, and in the case of the acoustic Doppler current profiler, quickly and easily provide three-dimensional stream-velocity profile data through much of the vertical water column. For much of the discussion of acoustic Doppler current profiler moving-boat methodology, the reader is referred to U.S. Geological Survey Techniques and Methods 3-A22 (Mueller and Wagner, 2009). Personal digital assistants (PDAs), electronic field notebooks, and other personal computers provide fast and efficient data-collection methods that are more error-free than traditional hand methods. The use of portable weirs and flumes, floats, volumetric tanks, indirect methods, and tracers in measuring discharge are briefly described.

  3. Discharge cleaning of carbon deposits

    International Nuclear Information System (INIS)

    Mozetic, M.; Vesel, A.; Drenik, A.

    2006-01-01

    Experimental results of discharge cleaning of carbon deposits are presented. Deposits were prepared by creating plasma in pure methane. The methane was cracked in RF discharge at the output power of 250 W. The resultant radicals were bonded to the wall of discharge vessel forming a thin film of hydrogenated black carbon with the thickness of about 200nm. The film was then cleaned in situ by oxygen plasma with the density of about 1x10 16 m -3 , electron temperature of 5 eV, neutral gas kinetic temperature of about 100 0 C and neutral atom density of 6x10 21 m -3 . The treatment time was 30 minutes. The efficiency of plasma cleaning was monitored by optical emission spectroscopy. As long as the wall was contaminated with carbon deposit, substantial emission of the CO molecules was detected. As the cleaning was in progress, the CO emission was decreasing and vanished after 30 minutes when the discharge vessel became free of any carbon. The results are explained by interaction of plasma radicals with carbon deposits. (author)

  4. High beta and second stability region transport and stability analysis

    International Nuclear Information System (INIS)

    1990-01-01

    This document summarizes progress made on the research of high beta and second region transport and stability. In the area second stability region studies we report on an investigation of the possibility of second region access in the center of TFTR ''supershots.'' The instabilities found may coincide with experimental observation. Significant progress has been made on the resistive stability properties of high beta poloidal ''supershot'' discharges. For these studies profiles were taken from the TRANSP transport analysis code which analyzes experimental data. Invoking flattening of the pressure profile on mode rational surfaces causes tearing modes to persist into the experimental range of interest. Further, the experimental observation of the modes seems to be consistent with the predictions of the MHD model. In addition, code development in several areas has proceeded

  5. A Safe and Interactive Method of Illuminating Discharge Tubes for Studying Emission Spectra

    Science.gov (United States)

    Lu, Zhe

    2012-01-01

    Discharge tubes are useful tools for teaching emission spectra and the discrete energy levels of the Bohr model. A new setup uses a plasma globe to illuminate the discharge tube and allows a higher degree of interactivity owing to the omission of a traditional, high-voltage power source. The decreased power consumption also reduces the heating of…

  6. Fluorescence of Diatomic ZnO in a Hollow Cathode Discharge

    Energy Technology Data Exchange (ETDEWEB)

    Cannavo, D.; Gerber, T.

    2004-03-01

    A hollow-cathode-discharge (HCD) was tested as a source of diatomic zinc oxide molecules in the gas phase. Discharge fluorescence was monitored in the spectral region between 300 nm and 600 nm. A band emission could be observed around 560 nm in agreement with earlier published observations. (author)

  7. Recent progress in discharge-based soft x-ray lasers at IPP ASci CR

    Science.gov (United States)

    Kolacek, Karel; Schmidt, Jiri; Prukner, Vaclav; Frolov, Oleksandr; Straus, Jaroslav

    2008-01-01

    Activity of our laboratory in the field of pulsed high-current proximity-wall-stabilised discharges - media for XUV/soft X-ray generation and amplification (XUV/soft X-ray lasing), and our effort to demonstrate lasing of discharge-based sources at the wavelength 60 kA).

  8. Surface modification by EUV laser beam based on capillary discharge

    Czech Academy of Sciences Publication Activity Database

    Frolov, Oleksandr; Koláček, Karel; Schmidt, Jiří; Štraus, Jaroslav; Prukner, Václav; Shukurov, A.

    -, č. 58 (2011), s. 484-487 ISSN 2010-376X. [International Conference on Fusion and Plasma Physics. Bali, Indonésie, 26.10.2011-28.10.2011] R&D Projects: GA AV ČR KAN300100702; GA MŠk LA08024; GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z20430508 Keywords : soft x-ray * EUV * laser * radiation * source * capillary * discharge * plasma * ablation * surface modification Subject RIV: BL - Plasma and Gas Discharge Physics http://www.waset.org/journals/waset/v58/v58-99.pdf

  9. Atomization of thorium in a hollow-cathode type discharge

    International Nuclear Information System (INIS)

    Pianarosa, P.; Demers, Y.; Gagne, J.M.

    1984-01-01

    The atomization of thorium metal in a hollow-cathode electrical discharge has been investigated. Laser absorption spectroscopy with the laser tuned on the 5760.55 A (0-17355 1 cm -1 ) transition of Th I was used to evaluate the density of atoms in the 3 F 2 ground state. The results obtained (densities up to 10 13 atoms cm -3 ) show that our discharge tube is a suitable source of thorium metal atoms for laser assisted spectroscopic analysis of this element. (author)

  10. SVM-based Partial Discharge Pattern Classification for GIS

    Science.gov (United States)

    Ling, Yin; Bai, Demeng; Wang, Menglin; Gong, Xiaojin; Gu, Chao

    2018-01-01

    Partial discharges (PD) occur when there are localized dielectric breakdowns in small regions of gas insulated substations (GIS). It is of high importance to recognize the PD patterns, through which we can diagnose the defects caused by different sources so that predictive maintenance can be conducted to prevent from unplanned power outage. In this paper, we propose an approach to perform partial discharge pattern classification. It first recovers the PRPD matrices from the PRPD2D images; then statistical features are extracted from the recovered PRPD matrix and fed into SVM for classification. Experiments conducted on a dataset containing thousands of images demonstrates the high effectiveness of the method.

  11. Harwell Laboratory: radioactive discharges and environmental monitoring

    International Nuclear Information System (INIS)

    1991-06-01

    The United Kingdom Atomic Energy Authority's Harwell Laboratory is situated some 5 miles west of Didcot in Oxfordshire. The AEA Businesses located at the Laboratory carry out a wide range of nuclear and non-nuclear investigations for customers in the UK and overseas. This report provides information on disposal of radioactive waste from Harwell and on associated environmental monitoring for the calendar year 1990. In most instances information has also been provided on measurements made in previous years to show the 1990 results in their historical perspective. The National Radiological Protection Board, (NRPB) currently recommends a primary dose limit for individual members of the public of 1 mSv per year from sources other than natural background radiation, and that operations of a single site such as Harwell should give rise to a dose of no more than 0.5 mSv per year. No member of the public is judged to have exceeded this dose as a consequence of discharges made in 1990. Throughout this report, discharge measurements have been assessed against derived limits corresponding to a dose of 0.5 mSv, consistent with NRPB advice. At the end of March 1990, the Harwell materials testing reactors, DIDO and PLUTO, were shut down for the final time after over 34 years' operation. Later in the year the GLEEP reactor was closed down after 43 years of continuous operation, the longest serving reactor in the world. (author)

  12. Ultraviolet gas-discharge lamp on iodine molecules

    Science.gov (United States)

    Shuaibov, A. K.; Minya, A. I.; Gomoki, Z. T.; Kalyuzhnaya, A. G.; Shchedrin, A. I.

    2010-08-01

    The emission characteristics of a pulsed-periodic UV radiation source are reported. The source excited by a pulsed-periodic capacitive discharge initiated in helium-iodine vapor, neon-iodine vapor, or krypton-iodine vapor mixtures radiates in the spectral range 200-450 nm. It is shown that most of the plasma radiation power concentrates in the integral line of the iodine atom (206.2 nm) and in the D'- A' band of the iodine molecule with a maximum at 342 nm. The radiation intensity of the lamp is optimized in accordance with the partial pressure of the inert gases. The discharge plasma parameters that are of interest for simulating the process kinetics and the output characteristics of an UV source based on molecular iodine, atomic iodine, and xenon iodide are calculated in helium-iodine vapor and xenon-iodine vapor mixtures.

  13. Proton beam source

    International Nuclear Information System (INIS)

    Auslender, V.L.; Lazarev, V.N.; Panfilov, A.D.

    1979-01-01

    A proton pulse source with penning discharge and a cathode needle in the discharge chamber is described. The source is simple in design and has a great service life. An electromagnet induces a magnetic field of the order of 700 Oe along the axis of the discharge chamber. In this field the discharge is ignited between the left and right cathodes when a positive voltage is applied to the anode. A hole in the recess of the right cathode serves to provide the injection of plasma into the accelerating gap. The cathodes and the anode unit are set into a sleeve welded to magnet poles. Through a magnetic circuit this unit is placed on a high-voltage ceramic insulator. For extraction and initial shaping of an ion beam with a divergence angle of 3 0 use is made of extraction electrodes which form the Pierce optics. Further shaping of the ion beam is realized by an electrostatic lens. Tungsten grids in the holes of grounded electrodes increase the focusing effect of the lens. At the input of the first accelerating gap of an accelerator the described source provides an ion peak current of 140 mA at 65% content of protons and a normalized emittance of no more than 4x10 -5 cmxrad

  14. New discharge tube with virtual cathode

    International Nuclear Information System (INIS)

    Seidelmann, L.; Aubrecht, L.

    2003-01-01

    Till this time known methods of the excitation of the discharge between electrodes are using either secondary or thermo emission of electrons by the cathode. Usually we speak about the self-maintained discharge. Lifetime of the cathode, that is shortened by the emission, limits in principle, the lifetime of the whole discharge tube. The discharge can, according to the present state of the art, be induced also by the inductive way. Arrangement for excitation of such discharge is rather expensive. The construction of the inductive excited discharge tube is considerably influenced by the necessity of the limitation of the losses in excitation magnetic circuits. Especially length of the discharge and pressure of the working gas are limited by the economic standpoints. Function of the discharge is always connected with unwanted electromagnetic radiation, whose restraint is expensive and represents limiting factor for arrangement of the discharge tube (Authors)

  15. Discharge current distribution in stratified soil under impulse discharge

    Science.gov (United States)

    Eniola Fajingbesi, Fawwaz; Shahida Midi, Nur; Elsheikh, Elsheikh M. A.; Hajar Yusoff, Siti

    2017-06-01

    The mobility of charge particles traversing a material defines its electrical properties. Soil (earth) have long been the universal grounding before and after the inception of active ground systems for electrical appliance purpose due to it semi-conductive properties. The soil can thus be modelled as a single material exhibiting semi-complex inductive-reactive impedance. Under impulse discharge such as lightning strikes to soil this property of soil could result in electric potential level fluctuation ranging from ground potential rise/fall to electromagnetic pulse coupling that could ultimately fail connected electrical appliance. In this work we have experimentally model the soil and lightning discharge using point to plane electrode setup to observe the current distribution characteristics at different soil conductivity [mS/m] range. The result presented from this research indicate above 5% shift in conductivity before and after discharge which is significant for consideration when dealing with grounding designs. The current distribution in soil have also be successfully observed and analysed from experimental result using mean current magnitude in relation to electrode distance and location, current density variation with depth all showing strong correlation with theoretical assumptions of a semi-complex impedance material.

  16. Atmospheric air dielectric barrier discharge excited by nanosecond pulse and AC used for improving the hydrophilicity of aramid fibers

    Science.gov (United States)

    Hao, YUAN; Wenchun, WANG; Dezheng, YANG; Zilu, ZHAO; Li, ZHANG; Sen, WANG

    2017-12-01

    In this paper, a long line-shape dielectric barrier discharge excited by a nanosecond pulse and AC is generated in atmospheric air for the purpose of discussing the uniformity, stability and ability of aramid fiber treatment. The discharge images, waveforms of current and voltage, optical emission spectra, and gas temperatures of both discharges are compared. It is found that nanosecond pulsed discharge has a more uniform discharge morphology, higher energy efficiency and lower gas temperature, which indicates that nanosecond pulsed discharge is more suitable for surface modification. To reduce the water contact angle from 96° to about 60°, the energy cost is only about 1/7 compared with AC discharge. Scanning electron microscopy, Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy are employed to understand the mechanisms of hydrophilicity improvement.

  17. 75 FR 35712 - National Pollutant Discharge Elimination System (NPDES): Use of Sufficiently Sensitive Test...

    Science.gov (United States)

    2010-06-23

    ... Permits Division, Office of Wastewater Management (4203M), Environmental Protection Agency, 1200.... National Technology Transfer and Advancement Act J. Executive Order 12898: Federal Actions To Address... ``permitting authorities''). These point source dischargers include publicly owned treatment works (POTWs) and...

  18. Impaired postural stability after laparoscopic surgery

    DEFF Research Database (Denmark)

    Eskildsen, K Z; Staehr-Rye, A K; Rasmussen, L S

    2015-01-01

    BACKGROUND: Early postoperative mobilisation may reduce patient morbidity and improve hospital efficiency by accelerated discharge. The aim of this study was to measure postural stability early after laparoscopic surgery in order to assess how early it is safe to mobilise and discharge patients....... METHODS: We included 25 women undergoing outpatient gynaecological laparoscopic surgery in the study. Patients received standardised anaesthesia with propofol, remifentanil and rocuronium. Postural stability was assessed preoperatively, at 30 min after tracheal extubation, and at discharge from the post......-anaesthesia care unit using a force platform where sway area, mean sway and sway velocity were determined. The assessments were done with eyes closed and with eyes open. The primary outcome was the change in sway area with eyes closed 30 min after extubation. Data are reported as median (25-75% range). RESULTS...

  19. Feasibility of wear compensation in micro EDM milling based on discharge counting and discharge population characterization

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; Tristo, G.

    2011-01-01

    This paper investigates the applicability of real time wear compensation in micro EDM milling based on discharge counting and discharge population characterization. Experiments were performed involving discharge counting and tool electrode wear measurement in a wide range of process parameters...

  20. Discharge data from 50 selected rivers for GCM validation

    International Nuclear Information System (INIS)

    Duemenil, L.; Isele, K.; Liebscher, H.J.; Schroeder, U.; Schumacher, M.; Wilke, K.

    1993-01-01

    This Technical Report refers to a joint project between GRDC Koblenz and MPI Hamburg. The Global Runoff Data Centre operates under the auspieces of WMO at the Federal Institute of Hydrology (Bundesanstalt fuer Gewaesserkunde) in Koblenz. River discharge data of the 50 largest rivers provide an independent data source for the validation of the hydrological cycle in general circulation models. This type of data is particularly valuable, because in some cases the available time series are exceptionally long. The data are presented as time series of annual average discharge (averaged over the period for which data is available, see below for caveats) and as annual cycles of monthly mean discharge averaged over the length of the time series available. (orig./KW)

  1. Culvert analysis program for indirect measurement of discharge

    Science.gov (United States)

    Fulford, Janice M.; ,

    1993-01-01

    A program based on the U.S. Geological Survey (USGS) methods for indirectly computing peak discharges through culverts allows users to employ input data formats used by the water surface profile program (WSPRO). The program can be used to compute discharge rating surfaces or curves that describe the behavior of flow through a particular culvert or to compute discharges from measurements of upstream of the gradually varied flow equations and has been adapted slightly to provide solutions that minimize the need for the user to determine between different flow regimes. The program source is written in Fortran 77 and has been run on mini-computers and personal computers. The program does not use or require graphics capability, a color monitor, or a mouse.

  2. X-ray preionization for electric discharge lasers

    International Nuclear Information System (INIS)

    Lin, S.; Levatter, J.I.

    1979-01-01

    Using x rays of 60--200-keV photon energy (lambdaapprox.0.06--0.2 A) as an ionizing radiation source in a transmission-line-driven low-inductance discharge chamber, we have succeeded in generating spatially homogeneous pulsed avalanche discharges of several liter volume at greater than 1 atm pressure for up to 100-nsec duration. In concurrent laser generation experiments with relatively lossy windows, we have observed high-optical-quality pulsed uv laser output of up to 2 J/liter from such discharges in rare-gas/halogen mixtures, and IR laser output of up to 12.5 J/liter from a He/N 2 /CO 2 mixture

  3. Macroeconomic stability

    DEFF Research Database (Denmark)

    Jespersen, Jesper

    2004-01-01

    It is demonstrated that full employment and sustainable development not necessarily are conflicting goals. On the other hand macroeconomic stability cannot be obtained without a deliberate labour sharing policy and a shift in the composition of private consumption away from traditional material...

  4. Energy discharge heater power supply

    International Nuclear Information System (INIS)

    Jaskierny, W.

    1992-11-01

    The heater power supply is intended to supply capacitively stored,energy to embedded heater strips in cryo magnets. The amount of energy can be controlled by setting different charge different capacitor values. Two chassis' can be operated in series or interlocks are provided. The charge voltage, number of capacitors pulse can be monitored. There and dual channel has two discharge supplies in one chassis. This report reviews the characteristics of this power supply further

  5. Response of foraminifera to a reverse osmosis briny discharge

    Science.gov (United States)

    Small, Richard Eustace Aiken

    Reverse osmosis water treatment plants are becoming the preferred means of generating potable water for many eastern North Carolina communities. At these facilities, reject brine solutions---sometimes containing up to 10 times the initial concentration of dissolved solids---are created and often discharged into estuarine waters. Several state and federal agencies have expressed concern over the potential ecological impacts this wastewater could have on these sensitive environments. Monitoring of a brine discharge site in Currituck County, North Carolina revealed significantly higher conductivity values within ~50 m of the point source. One group of organisms that have proven useful in other studies for monitoring impact of anthropogenic pollution in estuaries is Foraminifera. Foraminifera are abundant microorganisms that are widespread in most marginal-marine and marine environments; nevertheless, individual taxa are highly selective of their habitat. Nearly all species build shells (tests) that are preserved in coastal sediments, allowing for reconstruction of previous marine conditions. Species abundance data was collected from surface and sub-surface samples taken in the area surrounding the brine point source. Two taxa (Ammobaculites spp. and Ammotium sp.) accounted for 98.5% of all normalized specimens. Abundance is significantly less in the sub-surface samples (Student's t-test, p<0.0001), likely due to taphonomic effects. Abundance does not appear correlated with discharge of the wastewater; instead, natural parameters appear to affect abundance in an assemblage to a greater degree. Species distribution is similar in surface and sub-surface samples. Foraminiferal diversity is significantly less near the discharge based on one sample collected within 5 m of the discharge site; samples at greater distances do not appear affected. Loss of diversity within a few meters of the discharge site is consistent with previous studies, but more data would be needed to

  6. The regulation of technetium-99 discharges at Sellafield

    International Nuclear Information System (INIS)

    Mayall, A.

    2002-01-01

    The reprocessing of spent Magnox fuel at BNFL Sellafield produces a liquid waste concentrate containing technetium-99 and other, more radiotoxic, radionuclides such as plutonium and americium. The concentrate is known as medium active concentrate (MAC). Prior to 1981, MAC was discharged to sea untreated after several years' storage, during which short-lived radionuclides underwent radioactive decay. In the early 1980s, discharges of MAC were suspended and it was retained in storage tanks, pending the construction of a plant to remove the radionuclides of greatest radiological concern (these did not include technetium- 99). The Enhanced Actinide Removal Plant started operation in 1994 and began to clear the backlog of stored waste MAC, as well as current arisings from Magnox reprocessing. As a consequence technetium-99 was once more discharged to sea. Subsequently, concentrations of this radionuclide in the marine environment increased. In particular, there was a significant increase in the concentration of technetium-99 in lobster in the Irish Sea. An increase in technetium-99 has also been detected at locations far distant from Sellafield, e.g. in Scandinavian coastal waters, albeit at very low concentrations. This dispersal of technetium- 99 throughout the Irish Sea and further afield has therefore caused concern, although the radiological impact is low. This paper examines the nature and source of the technetium-99 in sea discharges at Sellafield and the levels of past and current discharges as well as their impact. It goes on to describe the Environment Agency's recent proposals on the future regulation of technetium-99 discharges and how these should lead to substantial reductions in not only technetium-99 discharges, but also of other radionuclides such as caesium-137 and strontium-90. (author)

  7. Internal Electrostatic Discharge Monitor - IESDM

    Science.gov (United States)

    Kim, Wousik; Goebel, Dan M.; Jun, Insoo; Garrett, Henry B.

    2011-01-01

    A document discusses an innovation designed to effectively monitor dielectric charging in spacecraft components to measure the potential for discharge in order to prevent damage from internal electrostatic discharge (IESD). High-energy electrons penetrate the structural materials and shielding of a spacecraft and then stop inside dielectrics and keep accumulating. Those deposited charges generate an electric field. If the electric field becomes higher than the breakdown threshold (approx. =2 x 10(exp 5) V/cm), discharge occurs. This monitor measures potentials as a function of dielectric depth. Differentiation of potential with respect to the depth yields electric field. Direct measurement of the depth profile of the potential in a dielectric makes real-time electronic field evaluation possible without simulations. The IESDM has been designed to emulate a multi-layer circuit board, to insert very thin metallic layers between the dielectric layers. The conductors serve as diagnostic monitoring locations to measure the deposited electron-charge and the charge dynamics. Measurement of the time-dependent potential of the metal layers provides information on the amount of charge deposited in the dielectrics and the movement of that charge with time (dynamics).

  8. Corona discharges from a windmill and its lightning protection tower in winter thunderstorms

    Science.gov (United States)

    Wu, Ting; Wang, Daohong; Rison, William; Thomas, Ronald J.; Edens, Harald E.; Takagi, Nobuyuki; Krehbiel, Paul R.

    2017-05-01

    This paper presents lightning mapping array (LMA) observations of corona discharges from a windmill and its lightning protection tower in winter thunderstorms in Japan. Corona discharges from the windmill, called windmill coronas, and those from the tower, called tower coronas, are distinctly different. Windmill coronas occur with periodic bursts, generally radiate larger power, and possibly develop to higher altitudes than tower coronas do. A strong negative electric field is necessary for the frequent production of tower coronas but is not apparently related with windmill coronas. These differences are due to the periodic rotation of the windmill and the moving blades which can escape space charges produced by corona discharges and sustain a large local electric field. The production period of windmill coronas is related with the rotation period of the windmill. Surprisingly, for one rotation of the windmill, only two out of the three blades produce detectable discharges and source powers of discharges from these two blades are different. The reason for this phenomenon is still unclear. For tower coronas, the source rate can get very high only when there is a strong negative electric field, and the source power can get very high only when the source rate is very low. The relationship between corona discharges and lightning flashes is investigated. There is no direct evidence that corona discharges can increase the chance of upward leader initiation, but nearby lightning flashes can increase the source rate of corona discharges right after the flashes. The peak of the source height distribution of corona discharges is about 100 m higher than the top of the windmill and the top of the tower. Possible reasons for this result are discussed.

  9. An experimental study on discharge mechanism of pulsed atmospheric pressure glow discharges

    International Nuclear Information System (INIS)

    Huang Xiaojiang; Bao Yun; Sun Liqun; Zhang Jing; Shi, J. J.

    2011-01-01

    The discharge mechanism of pulsed atmospheric pressure glow discharges excited by the unipolar positive voltage pulses between two parallel plate electrodes with or without one dielectric barrier on the ground electrode in flowing helium has been characterized by nanosecond time resolved optical and electrical measurements. The uniform glow discharges can only be achieved when the voltage pulse duration is less than 1 μs with bare electrodes. With introducing a dielectric barrier on the ground electrode, a model of electrons traveling on the background ions between two discharge events is proposed to explain the discharge mechanism and characteristics in terms of discharge ignition, discharge spatial profile and discharge current amplitude.

  10. On self-sustainment of DC discharges with gridded anode

    Science.gov (United States)

    Yuan, Chengxun; Yao, Jingfeng; Eliseev, S. I.; Bogdanov, E. A.; Kudryavtsev, A. A.; Zhou, Zhongxiang

    2017-10-01

    The paper presents results of numerical investigation of a large-volume plasma source based on a DC discharge with gridded anode. Geometry and configuration of the electrodes were chosen so as to ensure the formation of a cathode sheath, which would accelerate electrons up to high energies and inject them into the post-anode space and create plasma. Simulations were carried out using a hybrid model, and distributions of the main discharge parameters were obtained in a wide range of currents. At low currents, cathode sheath occupies whole interelectrode gap while plasma is formed in the post-anode space. It is shown that ions moving through the anode grid into the interelectrode gap cause reduction of discharge voltage when compared to the case of classical obstructed discharge with virtually closed anode grid. At higher currents, however, plasma is formed within the interlectrode gap as well, and ions moving from plasma in the post-anode space become trapped by reversed electric field. This essentially nullifies influence of the post-anode plasma on discharge properties.

  11. Research on the Plasma Anemometer Based on AC Glow Discharge

    Directory of Open Access Journals (Sweden)

    Bing Yu

    2017-01-01

    Full Text Available A new plasma anemometer based on AC glow discharge is designed in this article. Firstly, theoretical analysis of plasma anemometer working principle is introduced to prove the feasibility of the experimental measurement method. Then the experiments are carried out to study the effects of different parameters on the static discharge characteristics of the plasma anemometer system, by which the system optimization methods are obtained. Finally, several groups of appropriate parameters are selected to build the plasma anemometer system based on resistance capacitance coupling negative feedback AC glow discharge, and different airflow speeds are applied to obtain the achievable velocity measurement range. The results show that there is a linear relationship between airflow velocity and discharge current in an allowable error range, which can be applied for airflow velocity measurement. Negative feedback coupling module, which is composed of the coupling resistance and the coupling capacitance, has good effects on improving the system stability. The measurement range of the airflow velocity is significantly increased when the electrode gap is 3 mm, coupling resistance is 470 Ω, and coupling capacitance is 220 pF.

  12. Early hospital discharge and early puerperal complications.

    Science.gov (United States)

    Ramírez-Villalobos, Dolores; Hernández-Garduño, Adolfo; Salinas, Aarón; González, Dolores; Walker, Dilys; Rojo-Herrera, Guadalupe; Hernández-Prado, Bernardo

    2009-01-01

    To evaluate the association between time of postpartum discharge and symptoms indicative of complications during the first postpartum week. Women with vaginal delivery at a Mexico City public hospital, without complications before the hospital discharge, were interviewed seven days after delivery. Time of postpartum discharge was classified as early (25 hours). The dependent variable was defined as the occurrence and severity of puerperal complication symptoms. Out of 303 women, 208 (68%) were discharged early. However, women with early discharge and satisfactory prenatal care had lower odds of presenting symptoms in early puerperium than women without early discharge and inadequate prenatal care (OR 0.36; 95% confidence intervals = 0.17-0.76). There was no association between early discharge and symptoms of complications during the first postpartum week; the odds of complications were lower for mothers with early discharge and satisfactory prenatal care.

  13. EPA Region 1 No Discharge Zones

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset details No Discharge Zones (NDZ) for New England. Boaters may not discharge waste into these areas. Boundaries were determined mostly by Federal...

  14. Measurement of radiation and temperature of cathod spots in excimer laser discharge; Ekishima reza reiki hodennai ni fukumareru inkyoku kiten no kogakuteki kansoku to ondo no sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Minamitani, Y.; Nakatani, H. [Mitsubishi Electric Corp., Tokyo (Japan)

    1996-08-20

    Excimer laser is used in various fields such as luminous source for steppers, annealing treatment, ablation process, nuclear fusion and so on. In this paper, the radiation timing and gas temperature of cathode spots, streamer discharges and glow discharges in KrF excimer are measured by observing the radiating spectra thereof. The following conclusions are obtained from the results of the present study. Cathode spots begin to radiate at about 20ns after the discharge initiation, then the first and second radiation peaks are observed respectively when the discharge current reversing after passing zero point and the reserved discharged current approaching zero point. Streamer discharge makes flashover between electrodes at the second radiation peak of cathode spots, while the glow discharges almost disappear when streamer discharges occurring. The temperatures of cathode spots and glow discharge as 5500K and 2600K respectively are almost constant and independent upon the discharging voltage of laser. 14 refs., 12 figs.

  15. Basic Studies of Distributed Discharge Limiters

    Science.gov (United States)

    2014-02-10

    electron avalanche ionization discharges induced by a focused 110 GHz millimeter-wave beam in atmospheric air. Discharges take place in a free volume of...plasma. 3.1.7 Vacuum Ultraviolet emission from pulsed discharges at atmospheric pressure. Fig. 6. Energy level diagram for molecular and...the utilized spectral simulation software, SPECTRAPLOT. 3.1.8 Non-intrusive diagnostic method for dissociation degree in pulsed discharges

  16. Capacitor discharges, magnetohydrodynamics, X-rays, ultrasonics

    CERN Document Server

    Früngel, Frank B A

    1965-01-01

    High Speed Pulse Technology, Volume 1: Capacitor Discharges - Magnetohydrodynamics - X-Rays - Ultrasonics deals with the theoretical and engineering problems that arise in the capacitor discharge technique.This book discusses the characteristics of dielectric material, symmetrical switch tubes with mercury filling, and compensation conductor forms. The transformed discharge for highest current peaks, ignition transformer for internal combustion engines, and X-ray irradiation of subjects in mechanical motion are also elaborated. This text likewise covers the transformed capacitor discharge in w

  17. Expansion of a nitrogen discharge by sound

    International Nuclear Information System (INIS)

    Antinyan, M.A.; Galechyan, G.A.; Tavakalyan, L.B.

    1992-01-01

    When the background pressure and the discharge current in a gas discharge are raised the plasma column is tightened up into a filament. Then the discharge occupies a region of the discharge tube whose transverse dimensions are substantially less than those of the tube. This contraction phenomenon in discharges restricts the range of parameters used in various devices to the range of relatively low discharge currents and low gas pressures. This contraction interferes with creating high-power gas lasers, since it acts destructively on the lasing process. In order to suppress filamentation of discharges the working gas has been pumped through the system at high speed, with considerable success. The turbulent mixing in the stream plays an important role in creating an uncontracted discharge at high pressures. The purpose of the present work is to study the possibility of undoing the contraction of a nitrogen discharge, which is one of the main components in the operation of a CO 2 laser, by introducing an intense sound wave in the discharge tube. Discharge contraction and the effect of a sound wave propagating along the plasma column have been investigated experimentally in nitrogen by studying the current-voltage characteristics of a contracted discharge. 6 refs., 3 figs

  18. Tides Stabilize Deltas until Humans Interfere

    Science.gov (United States)

    Hoitink, T.; Zheng Bing, W.; Vermeulen, B.; Huismans, Y.; Kastner, K.

    2017-12-01

    Despite global concerns about river delta degradation caused by extraction of natural resources, sediment retention by reservoirs and sea-level rise, human activity in the world's largest deltas intensifies. In this review, we argue that tides tend to stabilize deltas until humans interfere. Under natural circumstances, delta channels subject to tides are more stable than their fluvial-dominated counterparts. The oscillatory tidal flow counteracts the processes responsible for bank erosion, which explains why unprotected tidal channels migrate only slowly. Peak river discharges attenuate the tides, which creates storage space to accommodate the extra river discharge during extreme events and as a consequence, reduce flood risk. With stronger tides, the river discharge is being distributed more evenly over the various branches in a delta, preventing silting up of smaller channels. Human interference in deltas is massive. Storm surge barriers are constructed, new land is being reclaimed and large-scale sand excavation takes place, to collect building material. Evidence from deltas around the globe shows that in human-controlled deltas the tidal motion often plays a destabilizing role. In channels of the Rhine-Meuse Delta, some 100 scour holes are identified, which relates to the altered tidal motion after completion of a storm surge barrier. Sand mining has led to widespread river bank failures in the tidally-influenced Mekong Delta. The catastrophic flood event in the Gauges-Brahmaputra Delta by Cyclone Aila, which caused the inundation of an embanked polder area for over two years, was preceded by river bank erosion at the mouths of formal tidal channels that were blocked by the embankment. Efforts to predict the developments of degrading deltas are few. Existing delta models are capable of reproducing expanding deltas, which is essentially a matter of simulating the transport of sediment from source in a catchment to the sink in a delta. Processes of soil

  19. Protection of neutral-beam-accelerator electrodes from spark discharges

    International Nuclear Information System (INIS)

    Praeg, W.F.

    1978-01-01

    The high-voltage (HV) electrodes of neutral beam sources (NBS's) must be protected from occasional sparks to ground. Spark currents can be limited with special transformers and reactors which introduce time delays that are long enough to quench the spark or to disconnect the energy source. A saturated time delay transformer (STDT) connected in series with the HV power supply detects spark faults and limits the current supplied by the power supply and its capacitance to ground; it also initiates spark quenching. Nonsaturated, longitudinal reactors limit the discharge current supplied by the energy stored in the circuit capacitance of the NBS filament and arc power supplies long enough to discharge this capacitance into a resistor. The design principles of these protective circuits are presented in this paper

  20. Protection of neutral-beam accelerator electrodes from spark discharges

    International Nuclear Information System (INIS)

    Praeg, W.F.

    1977-01-01

    The high-voltage (HV) electrodes of neutral beam sources (NBS's) must be protected from occasional sparks to ground. Spark currents can be limited with special transformers and reactors which introduce time delays that are long enough to quench the spark or to disconnect the energy source. A saturated time delay transformer (STDT) connected in series with the HV power supply detects spark faults and limits the current supplied by the power supply and its capacitance to ground; it also initiates spark quenching. Nonsaturated, longitudinal reactors limit the discharge current supplied by the energy stored in the circuit capacitance of the NBS filament and arc power supplies long enough to discharge this capacitance into a resistor. The design principles of these protective circuits are presented

  1. EDITORIAL: Mercury-free discharges for lighting

    Science.gov (United States)

    Haverlag, M.

    2007-07-01

    This special Cluster of articles in Journal of Physics D: Applied Physics covers the subject of mercury-free discharges that are being investigated by different light source researchers, as an alternative to existing mercury-containing lamps. The main driving force to move away from mercury-containing discharge light sources is connected to the environmentally unfriendly nature of mercury. After inhalation or direct contact, severe mercury exposure can lead to damage to human brain cells, the kidneys, the liver and the nervous system. For this reason, the use of mercury in products is becoming more and more restricted by different governmental bodies. In the lighting industry, however, many products still make use of mercury, for different reasons. The main reason is that mercury-containing products are, in most cases, more efficient than mercury-free products. For a realistic comparison of the environmental impact, the mercury-contamination due to electricity production must be taken into account, which depends on the type of fuel being used. For an average European fuel-mix, the amount of mercury that is released into the environment is around 29 μg kWh-1. This means that a typical 30 W TL lamp during a lifetime of 20,000 hours will release a total of about 20 mg mercury due to electricity production, which exceeds the total mercury dose in the lamp (more and more of which is being recycled) by a factor of 5-10 for a modern TL lamp. This illustrates that, quite apart from other environmental arguments like increased CO2 production, mercury-free alternatives that use more energy can in fact be detrimental for the total mercury pollution over the lifetime of the lamp. For this reason, the lighting industry has concentrated on lowering the mercury content in lamps as long as no efficient alternatives exist. Nevertheless, new initiatives for HID lamps and fluorescent lamps with more or less equal efficiency are underway, and a number of them are described in this

  2. Narrow gap electronegative capacitive discharges

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, E.; Lieberman, M. A.; Lichtenberg, A. J. [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States)

    2013-10-15

    Narrow gap electronegative (EN) capacitive discharges are widely used in industry and have unique features not found in conventional discharges. In this paper, plasma parameters are determined over a range of decreasing gap length L from values for which an electropositive (EP) edge exists (2-region case) to smaller L-values for which the EN region connects directly to the sheath (1-region case). Parametric studies are performed at applied voltage V{sub rf}=500 V for pressures of 10, 25, 50, and 100 mTorr, and additionally at 50 mTorr for 1000 and 2000 V. Numerical results are given for a parallel plate oxygen discharge using a planar 1D3v (1 spatial dimension, 3 velocity components) particle-in-cell (PIC) code. New interesting phenomena are found for the case in which an EP edge does not exist. This 1-region case has not previously been investigated in detail, either numerically or analytically. In particular, attachment in the sheaths is important, and the central electron density n{sub e0} is depressed below the density n{sub esh} at the sheath edge. The sheath oscillations also extend into the EN core, creating an edge region lying within the sheath and not characterized by the standard diffusion in an EN plasma. An analytical model is developed using minimal inputs from the PIC results, and compared to the PIC results for a base case at V{sub rf}=500 V and 50 mTorr, showing good agreement. Selected comparisons are made at the other voltages and pressures. A self-consistent model is also developed and compared to the PIC results, giving reasonable agreement.

  3. Discharge planning is CMS' focus.

    Science.gov (United States)

    2012-02-01

    The Centers for Medicare and Medicaid Services (CMS) has announced its intention to add three new questions about discharge planning to the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey in 2012. Case managers should make sure that patients have a choice of options for the next level of care. Make sure there are beds available and then give the patients a list of appropriate provides from which to choose. CAHPS scores are increasing in importance as CMS moves to value-based purchasing.

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

    Energy Technology Data Exchange (ETDEWEB)

    Haggard, R.D.

    1996-08-12

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

  5. Development of a discharge planning mentorship program.

    Science.gov (United States)

    Hansen, D C; Matt-Hensrud, N; Holland, D E; Severson, M A

    2000-01-01

    Discharge planning coordinators at a tertiary medical center developed a Discharge Planning Mentorship Program. The group established the educational program to support the autonomy of the staff primary nurse in the discharge planning component of professional practice. To establish the program, the discharge planning coordinators used the underlying principle of "CollaMentoach." The term is an acronym combining the three core concepts of collaboration, mentoring, and coaching. Program planning and marketing, participant selection, curriculum development, and curriculum evaluation are included to guide staff development specialists and nurse managers in the formulation of a program to enhance staff nurse discharge planning skills.

  6. Discharge residence of TLD tagged fish

    International Nuclear Information System (INIS)

    Romberg, G.P.; Prepejchal, W.

    1974-01-01

    Although visual observations suggested that fish remained in the discharge for considerable periods, temperature-sensitive tags indicated the majority of fish spend less than 50 hr or 10 percent of the time at discharge temperatures. During 1974 a second fish tagging study was conducted, using temperature-sensitive tags to yield discharge residence times of Lake Michigan salmonids at Point Beach thermal discharge. Preliminary results revealed that many fish tag values were close to Unit I line indicating that calculated maximum discharge residence times for these fish will be nearly 100 percent of the elapsed time

  7. Environmental impact of brine discharge from desalination plant

    OpenAIRE

    Gregorič, Elio

    2016-01-01

    Population growth demands constant increase in drinkable water production. Many developing countries have a shortage of fresh water so they have to tap into alternative water sources. Desalination technologies provide the possibility to produce fresh water from sea or brackish water. Every technological process has its by-products; the major one in desalination is the rejected brine. This thesis presents some research made on the influence of brine discharge on the marine environments and ...

  8. Electromagnetic fields produced by simulated spacecraft discharges

    Science.gov (United States)

    Nonevicz, J. E.; Adamo, R. C.; Beers, B. L.; Delmer, T. N.

    1980-01-01

    The initial phase of a broader, more complete program for the characterization of electrical breakdowns on spacecraft insulating materials is described which consisted of the development of a discharge simulator and characterization facility and the performance of a limited number of discharge measurements to verify the operation of the laboratory setup and to provide preliminary discharge transient field data. A preliminary model of the electromagnetic characteristics of the discharge was developed. It is based upon the "blow off" current model of discharges, with the underlying assumption of a propagating discharge. The laboratory test facility and discharge characterization instrumentation are discussed and the general results of the "quick look" tests are described on quartz solar reflectors aluminized Kapton and silver coated Teflon are described.

  9. [Severe vaginal discharge following rectal surgery].

    Science.gov (United States)

    Burg, L C; Bremers, A J A; Heesakkers, J P F A; Kluivers, K B

    2018-01-01

    Almost 50% of women who have had rectal surgery subsequently develop vaginal discharge. Due to the recurrent and unexpected nature of this heavy discharge, they often experience it as very distressing. Many of these women undergo extensive diagnostic tests that are mainly focused on identifying fistula formation. If no fistula is found, in most cases no other cause for severe vaginal discharge can be demonstrated. In our practice, we saw three patients (49-, 54- and 74-years-old, respectively) with similar severe vaginal discharge after rectal surgery and in whom no explanation for the vaginal discharge could be found. For this reason we conducted a literature search into this condition. Anatomical changes appear to be responsible for heavy vaginal discharge following rectal surgery. Changes in pelvic floor muscles and compression of the distal part of the vagina may lead to pooling of fluid in the proximal part of the vagina, resulting in severe discharge. Symptomatic treatment may reduce the symptoms.

  10. Electrostatic discharge concepts and definitions

    Energy Technology Data Exchange (ETDEWEB)

    Borovina, Dan L [Los Alamos National Laboratory

    2008-01-01

    Many objects -like a human body, plastic wrap, or a rolling cart -that are electrically neutral, overall, can gain a net electrostatic charge by means of one of three methods: induction, physical transfer, or triboelectric charging (separation of conductive surfaces). The result is a voltage difference between the charged object and other objects, creating a situation where current flow is likely if two objects come into contact or close proximity. This current flow is known as electrostatic discharge, or ESD. The energy and voltage of the discharge can be influenced by factors such as the temperature and humidity in the room, the types of materials or flooring involved, or the clothing and footwear a person uses. Given the possible ranges of the current and voltage characteristic of an ESD pulse, it is important to consider the safety risks associated with detonator handling, assembly and disassembly, transportation and maintenance. For main charge detonators, these safety risks include high explosive violent reactions (HEVR) as well as inadvertent nuclear detonations (lND).

  11. Uncertainty regarding instantaneous discharge obtained from stage–discharge rating curves built with low density discharge measurements

    Directory of Open Access Journals (Sweden)

    Juan Felipe Martínez Plata

    2012-01-01

    Full Text Available This work concerned uncertainty analysis for constructing stage–discharge rating curves to estimate error or uncertainty regarding calculated discharges, considering different discharge measurement availability scenarios. A methodology was used for creating artificial samples of discharge measurements from real data observed in the field and the effect of variation on measurement quantity and distribution concerning instantaneous discharge uncertainty was then studied. The results indicated that discharge uncertainty mostly depends on the number of river discharge measurements used for rating curve calibration and on the extent of extrapolation outside the range of measured river water levels. This research found that uncertainty regarding instantaneous discharges calculated for the area within average level values could be as high as 14% when the rating curve was calibrated with few measurements. Uncertainty can reach 20% and 60% for high and low water level values, respectively, or even higher depending on the extent of rating curve extrapolation. This work established that 35 discharge measurements for rating curve calibration were needed to fulfill World Meteorological Organization standards concerning discharge defined for low water level values.

  12. Sources for charged particles; Les sources de particules chargees

    Energy Technology Data Exchange (ETDEWEB)

    Arianer, J.

    1997-09-01

    This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.).

  13. Magnesium-aerial primary current source

    Directory of Open Access Journals (Sweden)

    Barba I. N.

    2007-12-01

    Full Text Available Novel metal-air chemical power sources (CPS 3,0-ВМБ-7,5 have been developed. They have an unlimited shelf life and, even after decades of storage, give almost 100% of the designed capacity. These sources are water-activated. An aqueous salt solution is used as an electrolyte. Such sources are designed for single continuous or discontinuous discharge. The paper presents electrochemical reactions at the electrodes during CPS discharge. Comparison of electrical characteristics of the developed power source and various types of "dry cells" has shown that the developed sources have higher energy characteristics.

  14. Preliminary Characterization of the Liquid Discharge of the Mexico Hospital

    International Nuclear Information System (INIS)

    Hernandez Rojas, A

    2001-01-01

    The generation and wrong handling of hospital waste constitutes a serious problem at national level. In this work, a preliminary characterization of the discharge it liquidates of the Mexico Hospital is carried out. For it, different pouring points were analyzed inside the institution; they are: Laundry, Central Kitchen, Clinical Laboratory, X-Rays, Laboratory of Biomass, Morgue, and the final discharge of the hospital. This with the purpose of knowing the handling of the liquid waste in the health center, the sanitary quality of these liquids and their influence in the raw waters of the Mexico Hospital in the receiving body. For this study, we first coordinated with the personnel of each department to know about the handling and type of liquid residuals that are discharged to the system of pipes. Later on the physical-chemical and biological tests were carried out with base in two compound samplings done the days October 26 and November 4 1998. Among the carried out tests we have: pH, DBO, DQO, SAAM, Fatty and Oils, Temperature, Nitrogen and Faecal Coniforms, depending on the characteristics of their origin point. At the end of the study, the obtained results were evaluated for each studied pouring point, and then the influence of these focuses on the quality of the raw waters of the hospital that discharge in a gulch located to the northwest side of the facilities was analyzed. The obtained results allow to preliminarily know the characterization of the liquid discharge of the Mexico Hospital and it was classified as a source of contamination. The Hospital requires of a biological treatment plant for those biodegradable poured liquids, and of a system of chemical treatment for that type of products used in the processes characteristic of each department. It is also required to take into account measures of reduction of contamination that diminish the quantity of waste from the source. (Author) [es

  15. Dump Truck Stability During Unloading

    Directory of Open Access Journals (Sweden)

    Yu. N. Baryshnikov

    2015-01-01

    Full Text Available The article deals with the problem of stability of the truck while unloading. The main symptom is a loss of stability of a vehicle rollover. The most common vehicle rollover occurs when unloading on sloped sites. The unloading area can be both longitudinal and cross slope. In this regard, the main task of the calculation is to determine the stability of the car the maximum allowable angle of discharge site and loads acting on the bearing system of the car.The paper presents a developed mathematical model of the truck when unloading on the longitudinal slope. It also offers the procedure of the step change in the parameters for the calculation of the critical angle of the site. The formulas for calculating the force interaction platform and the support system in the truck unloading at the site with a longitudinal slope are given. On the basis of the developed technique, a program for calculating longitudinal stability and loads acting on the bearing system dump trucks is created.Modern methods to assess stability while unloading the truck on a cross slope are analyzed. It is noted that the solution of this problem is developing in two directions. The first approach involves the testing truck samples on the special stands. Examples of bench tests on the stability of trucks are given. Another approach uses computational methods for the study. However, this requires the creation of a complex mathematical model of the truck, which should take into account the structural features of the suspension, the nonlinear elastic suspension components and tires, as well as the possibility of plastic deformation of the support system in torsion. In this formulation, the problem can only be solved using numerical methods and may be the subject of further research.The proposed approach allows multiple calculations for truck strength and stability already at an early designing stage in order to find the optimal design solution.

  16. 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.

  17. Implementation of Design Changes Towards a More Reliable, Hands-off Magnetron Ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Sosa, A. [Fermilab; Bollinger, D. S. [Fermilab; Karns, P. R. [Fermilab; Tan, C. Y. [Fermilab

    2017-12-07

    As the main H- ion source for the accelerator complex, magnetron ion sources have been used at Fermilab since the 1970’s. At the offline test stand, new R&D is carried out to develop and upgrade the present magnetron-type sources of H- ions of up to 80 mA and 35 keV beam energy in the context of the Proton Improvement Plan. The aim of this plan is to provide high-power proton beams for the experiments at FNAL. In order to reduce the amount of tuning and monitoring of these ion sources, a new electronic system consisting of a current-regulated arc discharge modulator allow the ion source to run at a constant arc current for improved beam output and operation. A solenoid-type gas valve feeds H2 gas into the source precisely and independently of ambient temperature. This summary will cover several studies and design changes that have been tested and will eventually be implemented on the operational magnetron sources at Fermilab. Innovative results for this type of ion source include cathode geometries, solenoid gas valves, current controlled arc pulser, cesium boiler redesign, gas mixtures of hydrogen and nitrogen, and duty factor reduction, with the aim to improve source lifetime, stability, and reducing the amount of tuning needed. In this summary, I will highlight the advances made in ion sources at Fermilab and will outline the directions of the continuing R&D effort.

  18. Study of the vortex-induced pressure excitation source in a Francis turbine draft tube by particle image velocimetry

    Science.gov (United States)

    Favrel, A.; Müller, A.; Landry, C.; Yamamoto, K.; Avellan, F.

    2015-12-01

    Francis turbines operating at part-load experience the development of a precessing cavitation vortex rope at the runner outlet, which acts as an excitation source for the hydraulic system. In case of resonance, the resulting pressure pulsations seriously compromise the stability of the machine and of the electrical grid to which it is connected. As such off-design conditions are increasingly required for the integration of unsteady renewable energy sources into the existing power system, an accurate assessment of the hydropower plant stability is crucial. However, the physical mechanisms driving this excitation source remain largely unclear. It is for instance essential to establish the link between the draft tube flow characteristics and the intensity of the excitation source. In this study, a two-component particle image velocimetry system is used to investigate the flow field at the runner outlet of a reduced-scale physical model of a Francis turbine. The discharge value is varied from 55 to 81 % of the value at the best efficiency point. A particular set-up is designed to guarantee a proper optical access across the complex geometry of the draft tube elbow. Based on phase-averaged velocity fields, the evolution of the vortex parameters with the discharge, such as the trajectory and the circulation, is determined for the first time. It is shown that the rise in the excitation source intensity is induced by an enlargement of the vortex trajectory and a simultaneous increase in the precession frequency, as well as the vortex circulation. Below a certain value of discharge, the structure of the vortex abruptly changes and loses its coherence, leading to a drastic reduction in the intensity of the induced excitation source.

  19. Experience with synchrotron radiation sources

    International Nuclear Information System (INIS)

    Krinsky, S.

    1987-01-01

    The development of synchrotron radiation sources is discussed, emphasizing characteristics important for x-ray microscopy. Bending magnets, wigglers and undulators are considered as sources of radiation. Operating experience at the national Synchrotron Light Source on the VUV and XRAY storage rings is reviewed, with particular consideration given to achieved current and lifetime, transverse bunch dimensions, and orbit stability. 6 refs., 3 figs

  20. Global Sourcing Flexibility

    DEFF Research Database (Denmark)

    Ørberg Jensen, Peter D.; Petersen, Bent

    2013-01-01

    and operations against the backdrop of the theory-based definition of the construct. We discuss in particular the importance of global sourcing flexibility for operational performance stability, and the trade-off between specialization benefits, emerging from location and service provider specialization, versus...... the higher costs (but decreased risk for value chain disruption) embedded in a more flexible global sourcing model that allows the firm to replicate and/or relocate activities across multiple locations. We develop a model and propositions on facilitating and constraining conditions of global sourcing...... flexibility. We finally discuss implications for management and international business research, within and beyond the domain of global services sourcing....