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Sample records for discharges operating regimes

  1. On the physical processes ruling an atmospheric pressure air glow discharge operating in an intermediate current regime

    SciTech Connect

    Prevosto, L. Mancinelli, B.; Chamorro, J. C.; Cejas, E.; Kelly, H.

    2015-02-15

    Low-frequency (100 Hz), intermediate-current (50 to 200 mA) glow discharges were experimentally investigated in atmospheric pressure air between blunt copper electrodes. Voltage–current characteristics and images of the discharge for different inter-electrode distances are reported. A cathode-fall voltage close to 360 V and a current density at the cathode surface of about 11 A/cm{sup 2}, both independent of the discharge current, were found. The visible emissive structure of the discharge resembles to that of a typical low-pressure glow, thus suggesting a glow-like electric field distribution in the discharge. A kinetic model for the discharge ionization processes is also presented with the aim of identifying the main physical processes ruling the discharge behavior. The numerical results indicate the presence of a non-equilibrium plasma with rather high gas temperature (above 4000 K) leading to the production of components such as NO, O, and N which are usually absent in low-current glows. Hence, the ionization by electron-impact is replaced by associative ionization, which is independent of the reduced electric field. This leads to a negative current-voltage characteristic curve, in spite of the glow-like features of the discharge. On the other hand, several estimations show that the discharge seems to be stabilized by heat conduction; being thermally stable due to its reduced size. All the quoted results indicate that although this discharge regime might be considered to be close to an arc, it is still a glow discharge as demonstrated by its overall properties, supported also by the presence of thermal non-equilibrium.

  2. Sharp transition between two regimes of operation of dc discharge with two anodes and thermionic emission from cathode

    SciTech Connect

    Mustafaev, A. S.; Grabovskiy, A.; Demidov, V. I.; Kaganovich, I. D.; Koepke, M. E.

    2014-05-15

    In a dc discharge plasma with two anodes and thermionic emission from cathode, the two anodes are used for plasma control. The main anode is placed between the cathode and the other auxiliary anode has a circular opening for passing electron current from the cathode to the second anode. It is experimentally demonstrated that a plasma may exhibit a sudden transition between two quasi-stable conditions as one increases the cathode-electron current collected by the auxiliary anode through an aperture, i.e., hole, in the main anode. In one regime, a bright glowing “ball-shaped double layer” appears on the plasma side having a potential drop of 10–15 eV and concomitant ionization in the neighboring region attached to the opening. The second regime is characterized by a uniform potential profile in plasma and an absence of the ball-shaped double layer. The transition between these regimes is accompanied by a significant change in plasma properties, such as the electron energy distribution function (EEDF). Controlling the EEDF is a valuable capability in technological applications. Increasing the gas pressure leads to the elimination of the first regime for sufficiently high gas pressure, the threshold being a few Torr. The disappearance of a regime transition can be explained by invoking an EEDF transition, from being nonlocal at low pressure to becoming local at high pressure. Local EEDF is determined by local values of electric field. Nonlocal EEDF is determined by electric field values elsewhere, and the electron can travel without energy loss over a path much longer than the discharge dimension.

  3. Capillary underwater discharges in repetitive pulse regime

    NASA Astrophysics Data System (ADS)

    de Baerdemaeker, F.; Monte, M.; Leys, C.

    2004-03-01

    In this study a capillary underwater discharge, that is sustained with AC (50 Hz) voltages up to 7.5 kV, is investigated. In a capillary discharge scheme, the current is, at some point along its path between two submerged electrodes, flowing through a narrow elongated bore in a dielectric material. When the current density is sufficiently high, local boiling and subsequent vapour breakdown results in the formation of a plasma within this capillary. At the same time the capillary emits an intense jet of vapour bubbles. Time-dependent electrical current, voltage and light emission curves are recorded for discharges in solutions of NaCl in distilled water and reveal different discharge regimes, depending on the conductivity and the excitation voltage, ranging from repetitive microsecond discharge pulses to a quasi-continuous discharge with a glow-like voltage-current characteristic.

  4. River Flow Regimes and Effective Discharge

    NASA Astrophysics Data System (ADS)

    Basso, S.; Sprocati, R.; Frascati, A.; Marani, M.; Schirmer, M.; Botter, G.

    2015-12-01

    The concept of effective discharge is widespread in geomorphology and river engineering and restoration. For example, it is used to design the most stable channel configuration, to estimate sedimentation rate and lifespan of reservoirs and to characterize the hydrologic forcing in models studying long-term evolution of rivers. Accordingly, the effective discharge has been the focus of countless empirical, theoretical and numerical studies, which found it to vary among catchments as a function of climate, landscape and river morphology, type of transport (dissolved, suspended or bedload), and of streamflow variability. The heterogeneity of the effective discharge values observed in different catchments challenges a thorough understanding of its pivotal drivers, and a consistent framework which explains observations carried out in different geographic areas is still lacking. In the present work, the observed diversity is explained in terms of the underlying heterogeneity of river flow regimes, by linking effective discharge to attributes of the sediment rating curve and to streamflow variability, as resulting from climatic and landscape drivers. An analytic expression of the effective ratio (i.e. the ratio between effective discharge and mean streamflow) is provided, which captures observed values of effective discharge for suspended sediment transport in a set of catchments of the continental United States. The framework disentangles hydrologic and landscape controls on effective discharge, and highlights distinct effective ratios of persistent and erratic hydrologic regimes (respectively characterized by low and high flow variability), attributable to intrinsically different streamflow dynamics. Clusters of river catchments characterized by similar streamflow dynamics can be identified. The framework provides an opportunity for first-order estimates of effective discharge in rivers belonging to different areas, based on the type of flow regime.

  5. Statistical instability of barrier microdischarges operating in townsend regime

    SciTech Connect

    Nagorny, V. P.

    2007-01-15

    The dynamics of barrier microdischarges operating in a Townsend regime is studied analytically and via kinetic particle-in-cell/Monte Carlo simulations. It is shown that statistical fluctuations of the number of charged particles in the discharge gap strongly influence the dynamics of natural oscillations of the discharge current and may even lead to a disruption of the discharge. Analysis of the statistical effects based on a simple model is suggested. The role of external sources in stabilizing microdischarges is clarified.

  6. Global patterns of change in discharge regimes for 2100

    NASA Astrophysics Data System (ADS)

    Sperna Weiland, F. C.; van Beek, L. P. H.; Kwadijk, J. C. J.; Bierkens, M. F. P.

    2012-04-01

    This study makes a thorough global assessment of the effects of climate change on hydrological regimes and their accompanying uncertainties. Meteorological data from twelve GCMs (SRES scenarios A1B and control experiment 20C3M) are used to drive the global hydrological model PCR-GLOBWB. This reveals in which regions of the world changes in hydrology can be detected that have a high likelihood and are consistent amongst the ensemble of GCMs. New compared to existing studies is: (1) the comparison of spatial patterns of regime changes and (2) the quantification of notable consistent changes calculated relative to the GCM specific natural variability. The resulting consistency maps indicate in which regions the likelihood of hydrological change is large. Projections of different GCMs diverge widely. This underscores the need of using a multi-model ensemble. Despite discrepancies amongst models, consistent results are revealed: by 2100 the GCMs project consistent decreases in discharge for southern Europe, southern Australia, parts of Africa and southwestern South-America. Discharge decreases strongly for most African rivers, the Murray and the Danube while discharge of monsoon influenced rivers slightly increases. In the Arctic regions river discharge increases and a phase-shift towards earlier peaks is observed. Results are comparable to previous global studies, with a few exceptions. Globally we calculated an ensemble mean discharge increase of more than ten percent. This increase contradicts previously estimated decreases, which is amongst others caused by the use of smaller GCM ensembles and different reference periods.

  7. Global patterns of change in discharge regimes for 2100

    NASA Astrophysics Data System (ADS)

    Sperna Weiland, F. C.; van Beek, L. P. H.; Kwadijk, J. C. J.; Bierkens, M. F. P.

    2011-12-01

    This study makes a thorough global assessment of the effects of climate change on hydrological regimes and their accompanying uncertainties. Meteorological data from twelve GCMs (SRES scenarios A1B, and control experiment 20C3M) are used to drive the global hydrological model PCR-GLOBWB. We reveal in which regions of the world changes in hydrology can be detected that are significant and consistent amongst the ensemble of GCMs. New compared to existing studies is: (1) the comparison of spatial patterns of regime changes and (2) the quantification of consistent significant change calculatesd relative to both the natural variability and the inter-model spread. The resulting consistency maps indicate in which regions likelihood of hydrological change is large. Projections of different GCMs diverge widely. This underscores the need of using a multi-model ensemble. Despite discrepancies amongst models, consistent results are revealed: by 2100 the GCMs project consistent decreases in discharge for southern Europe, southern Australia, parts of Africa and southwestern South-America. Discharge decreases are large for most African rivers, the Murray and the Danube. While discharge of Monsoon influenced rivers slightly increases. In the Arctic regions river discharge increases and a phase-shift towards earlier peaks is observed. Results are comparable to previous global studies, with a few exceptions. Globally we calculated an ensemble mean discharge increase of more than ten percent. This increase contradicts previously estimated decreases, which is amongst others caused by the use of smaller GCM ensembles and different reference periods.

  8. Discharge regimes in an intermediate-pressure gas with runaway electrons

    SciTech Connect

    Kolbychev, G.V.; Ptashnik, I.V.

    1985-09-01

    It is shown experimentally that there exist two transition discharge regimes that generate beams of runaway electrons. The first regime, previously unknown, prevails during sufficiently intense ultraviolet illumination and appears immediately after the breakdown of the gap. In this regime, the discharge current is determined solely by the photoelectron emission from the cathode caused by the external ultraviolet light and consists of current runaway electrons. The second regime is a hindered glow discharge; it either follows the photoelectron regime or, if the ultraviolet illumination is not sufficiently intense, arises directly during the breakdown. 6 references.

  9. Steady state plasma operation in RF dominated regimes on EAST

    SciTech Connect

    Zhang, X. J.; Zhao, Y. P.; Gong, X. Z.; Hu, C. D.; Liu, F. K.; Hu, L. Q.; Wan, B. N. Li, J. G.

    2015-12-10

    Significant progress has recently been made on EAST in the 2014 campaign, including the enhanced CW H&CD system over 20MW heating power (LHCD, ICRH and NBI), more than 70 diagnostics, ITER-like W-monoblock on upper divertor, two inner cryo-pumps and RMP coils, enabling EAST to investigate long pulse H mode operation with dominant electron heating and low torque to address the critical issues for ITER. H-mode plasmas were achieved by new H&CD system or 4.6GHz LHCD alone for the first time. Long pulse high performance H mode has been obtained by LHCD alone up to 28s at H{sub 98}∼1.2 or by combing of ICRH and LHCD, no or small ELM was found in RF plasmas, which is essential for steady state operation in the future Tokamak. Plasma operation in low collision regimes were implemented by new 4.6GHz LHCD with core Te∼4.5keV. The non-inductive scenarios with high performance at high bootstrap current fraction have been demonstrated in RF dominated regimes for long pulse operation. Near full non-inductive CD discharges have been achieved. In addition, effective heating and decoupling method under multi-transmitter for ICRF system were developed in this campaign, etc. EAST could be in operation with over 30MW CW heating and current drive power (LHCD ICRH NBI and ECRH), enhanced diagnostic capabilities and full actively-cooled metal wall from 2015. It will therefore allow to access new confinement regimes and to extend these regimes towards to steady state operation.

  10. Steady state plasma operation in RF dominated regimes on EAST

    NASA Astrophysics Data System (ADS)

    Zhang, X. J.; Zhao, Y. P.; Gong, X. Z.; Hu, C. D.; Liu, F. K.; Hu, L. Q.; Wan, B. N.; Li, J. G.

    2015-12-01

    Significant progress has recently been made on EAST in the 2014 campaign, including the enhanced CW H&CD system over 20MW heating power (LHCD, ICRH and NBI), more than 70 diagnostics, ITER-like W-monoblock on upper divertor, two inner cryo-pumps and RMP coils, enabling EAST to investigate long pulse H mode operation with dominant electron heating and low torque to address the critical issues for ITER. H-mode plasmas were achieved by new H&CD system or 4.6GHz LHCD alone for the first time. Long pulse high performance H mode has been obtained by LHCD alone up to 28s at H98˜1.2 or by combing of ICRH and LHCD, no or small ELM was found in RF plasmas, which is essential for steady state operation in the future Tokamak. Plasma operation in low collision regimes were implemented by new 4.6GHz LHCD with core Te˜4.5keV. The non-inductive scenarios with high performance at high bootstrap current fraction have been demonstrated in RF dominated regimes for long pulse operation. Near full non-inductive CD discharges have been achieved. In addition, effective heating and decoupling method under multi-transmitter for ICRF system were developed in this campaign, etc. EAST could be in operation with over 30MW CW heating and current drive power (LHCD ICRH NBI and ECRH), enhanced diagnostic capabilities and full actively-cooled metal wall from 2015. It will therefore allow to access new confinement regimes and to extend these regimes towards to steady state operation.

  11. Stable operating regime for traveling wave devices

    DOEpatents

    Carlsten, Bruce E.

    2000-01-01

    Autophase stability is provided for a traveling wave device (TWD) electron beam for amplifying an RF electromagnetic wave in walls defining a waveguide for said electromagnetic wave. An off-axis electron beam is generated at a selected energy and has an energy noise inherently arising from electron gun. The off-axis electron beam is introduced into the waveguide. The off-axis electron beam is introduced into the waveguide at a second radius. The waveguide structure is designed to obtain a selected detuning of the electron beam. The off-axis electron beam has a velocity and the second radius to place the electron beam at a selected distance from the walls defining the waveguide, wherein changes in a density of the electron beam due to the RF electromagnetic wave are independent of the energy of the electron beam to provide a concomitant stable operating regime relative to the energy noise.

  12. The operating regimes and basic control principles of SNPS Topaz''. [Cs

    SciTech Connect

    Makarov, A.N.; Volberg, M.S.; Grayznov, G.M.; Zhabotinsky, E.E.; Serbin, V.I. )

    1991-01-05

    The basic operating regimes of space nuclear power system (SNPS) Topaz'' are considered. These regimes include: prelaunch preparation and launch into working orbit, SNPS start-up to obtain desired electric power, nominal regime, SNPS shutdown. The main requirements for SNPS at different regimes are given, and the control algorithms providing these requirements are described. The control algorithms were chosen on the basis of theoretical studies and ground power tests of the SNPS prototypes. Topaz'' successful ground and flight tests allow to conclude that for SNPS of this type control algorithm providing required thermal state of cesium vapor supply system and excluding any possibility of discharge processes in current conducting elements is the most expedient at the start-up regime. At the nominal regime required electric power should be provided by maintenance of reactor current and fast-acting voltage regulator utilization. The limitation of the outlet coolant temperature should be foreseen also.

  13. Spatio-temporal analysis of discharge regimes based on hydrograph classification techniques in an agricultural catchment

    NASA Astrophysics Data System (ADS)

    Chen, Xiaofei; Bloeschl, Guenter; Blaschke, Alfred Paul; Silasari, Rasmiaditya; Exner-Kittridge, Mike

    2016-04-01

    The stream, discharges and groundwater hydro-graphs is an integration in spatial and temporal variations for small-scale hydrological response. Characterizing discharges response regime in a drainage farmland is essential to irrigation strategies and hydrologic modeling. Especially for agricultural basins, diurnal hydro-graphs from drainage discharges have been investigated to achieve drainage process inferences in varying magnitudes. To explore the variability of discharge responses, we developed an impersonal method to characterize and classify discharge hydrograph based on features of magnitude and time-series. A cluster analysis (hierarchical k-means) and principal components analysis techniques are used for discharge time-series and groundwater level hydro-graphs to analyze their event characteristics, using 8 different discharge and 18 groundwater level hydro-graphs to test. As the variability of rainfall activity, system location, discharge regime and soil moisture pre-event condition in the catchment, three main clusters of discharge hydro-graph are identified from the test. The results show that : (1) the hydro-graphs from these drainage discharges had similar shapes but different magnitudes for individual rainstorm; the similarity is also showed in overland flow discharge and spring system; (2) for each cluster, the similarity of shape insisted, but the rising slope are different due to different antecedent wetness condition and the rain accumulation meanwhile the difference of regression slope can be explained by system location and discharge area; and (3) surface water always has a close proportional relation with soil moisture throughout the year, while only after the soil moisture exceeds a certain threshold does the outflow of tile drainage systems have a direct ratio relationship with soil moisture and a inverse relationship with the groundwater levels. Finally, we discussed the potential application of hydrograph classification in a wider range of

  14. New discharge regime of the Huanghe (Yellow River): Causes and implications

    NASA Astrophysics Data System (ADS)

    Yu, Yonggui; Wang, Houjie; Shi, Xuefa; Ran, Xiangbin; Cui, Tingwei; Qiao, Shuqing; Liu, Yanguang

    2013-10-01

    This research examines changes in the Huanghe discharge regime over the past 60 years, and their multiple implications to the coastal environment. The results reveal that the Huanghe has been reverted from the pristine state of monsoonal nature, to a highly human-regulated hydrologic system. The new discharge regime of the Huanghe is featured with ~70% and ~90% reductions in water and sediment discharges to the sea, altered inter-annual distribution of runoff to the sea, decreasing amplitudes of flood peaks, ~66% loss in SSC (suspended sediment concentration) with coarsening particles, and dam-controlled "flood period". The altered discharge regime is mainly a consequence of anthropogenic interventions including soil conservation in the Loess Plateau, increasing water consumption and the multiple dam effects. The new discharge regime has a series of geological and ecological implications to the coastal environment, reflected by shrinking delta plain, altered sediment dispersal mechanism, restricted plume extent near the river mouth, less sediment reaching the deeper shelf environment, changing fate of the fluvial sediments, and altered ecological environment in the Bohai sea. This study provides a context for our understanding in changes of riverborne material to the sea for human-altered river system and their impacts on the coastal environment.

  15. Effective discharge for sediment transport: the sorting role of river flow regimes

    NASA Astrophysics Data System (ADS)

    Basso, Stefano; Sprocati, Riccardo; Frascati, Alessandro; Marani, Marco; Schirmer, Mario; Botter, Gianluca

    2016-04-01

    The effective discharge is a key concept in geomorphology, river engineering and restoration. It is used to design the most stable channel configuration, to estimate sedimentation rate and lifespan of reservoirs and to characterize the hydrologic forcing in models studying long-term evolution of rivers. Previous empirical, theoretical and numerical studies found the effective discharge to be affected by climate, landscape and river morphology, type of transport (dissolved, suspended or bedload), and by streamflow variability. However, the heterogeneity of values observed for the effective discharge challenges a clear understanding of its pivotal drivers, and a consistent framework which explains observations carried out in different catchments and geographic areas is still lacking. This work relates the observed diversity of effective discharge values to the underlying heterogeneity of river flow regimes. The effective ratio (i.e. the ratio between effective discharge and mean streamflow) is derived as a function of the empirical exponent of the sediment rating curve and the streamflow variability, resulting from climatic and landscape drivers. The proposed analytic expression helps to disentangle hydrologic and landscape controls on the effective discharge, and highlights distinct effective ratios of persistent and erratic hydrologic regimes (respectively characterized by low and high flow variability), attributable to intrinsically different streamflow dynamics. The framework captures observed values of effective discharge for suspended sediment transport in a set of catchments of the continental United States, and may allow for first-order estimates of effective discharge in rivers belonging to different climatic regions.

  16. Suppression of Instability of High Pressure DC Microplasma Operating in the Negative Differential Resistance (NDR) Regime

    NASA Astrophysics Data System (ADS)

    Mahamud, Rajib; Farouk, Tanvir I.

    2015-09-01

    Microplasma devices have been the subject of considerable interest and research during the last decade. In a DC system most of the operation regime of the plasma discharges studied fall in the ``abnormal,'' ``normal'' and ``corona'' modes - where a quasi-steady state is achieved. It is well known that even in a DC system the negative differential resistance (NDR) regime can trigger self pulsing discharges. These pulsations are initiated by the parasitic capacitance of the system hence governed by the response time of the power circuit. The circuit response time is required to be larger than the ion transit time to initiate the oscillations. In this present study a suppressor circuit element in the form of an inductor is used to restrain the plasma from switching to a self pulsing mode. It has been identified that the combined response time of the inductor and the plasma discharge (L/Rplasma) has to be larger than the power circuit time constant (RC) to achieve suppression. Inhibition of oscillation has been observed in both experiments and numerical simulations. The obtained voltage-current characteristics show that the inductor element extends the normal glow regime to lower current. Additional parametric simulations are conducted to map out a ``stable'' operation regime. The author would like to thank DARPA (ARO Grant No. W911NF1210007) and University of South Carolina (USC) for the financial support of the work.

  17. Nanosecond Repetitively Pulsed Discharges in Air at Atmospheric Pressure -- Experiment and Theory of Regime Transitions

    NASA Astrophysics Data System (ADS)

    Pai, David; Lacoste, Deanna; Laux, Christophe

    2009-10-01

    In atmospheric pressure air preheated from 300 to 1000 K, the Nanosecond Repetitively Pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and inter-electrode gap distance) of each discharge regime. Notably, there is a minimum gap distance for the existence of the glow regime that increases with decreasing gas temperature. A theory is developed to describe the Corona-to-Glow (C-G) and Glow-to-Spark (G-S) transitions for NRP discharges. The C-G transition is shown to depend on the Avalanche-to-Streamer Transition (AST) as well as the electric field strength in the positive column. The G-S transition is due to the thermal ionization instability. The minimum gap distance for the existence of the glow regime can be understood by considering that the applied voltage of the AST must be lower than that of the thermal ionization instability. This is a previously unknown criterion for generating glow discharges, as it does not correspond to the Paschen minimum or to the Meek-Raether criterion.

  18. Vibration analysis of a hydro generator for different operating regimes

    NASA Astrophysics Data System (ADS)

    Haţiegan, C.; Pădureanu, I.; Jurcu, M.; Nedeloni, M. D.; Hamat, C. O.; Chioncel, C. P.; Trocaru, S.; Vasile, O.; Bădescu, O.; Micliuc, D.; (Filip Nedeloni, L.; Băra, A.; (Barboni Haţiegan, L.

    2017-01-01

    Based on experimental measurements, this paper presents the vibration analysis of a hydro generator that equips a Kaplan hydraulic turbine of a Hydropower plant in Romania. This analysis means vibrations measurement to different operating regimes of the hydro generator respectively before installing it and into operation, namely putting off load mode (unexcited and excited) respectively putting on load mode. By comparing, through the experimental results obtained before and after the operation of hydro aggregates are observed vibrations improvements.

  19. The Influence of Dam Discharge Regime and Canyon Orientation on Ecosystem Metabolism in the Colorado River

    NASA Astrophysics Data System (ADS)

    Kennedy, T. A.; Tietjen, T.; Wright, S.

    2005-05-01

    Since the closure of Glen Canyon Dam and the beginning of flow regulation of the Colorado River in Grand Canyon in 1963, considerable efforts have been directed toward understanding the aquatic ecology of this altered ecosystem. Understanding what controls resource availability has been a central focus of these efforts because the Colorado River supports populations of sport fish and endangered humpback chub, both of which appear to be strongly resource limited. There is evidence that dam discharge regime and canyon orientation influence algal standing crop due to their effects on water velocity (scour) and solar insolation, respectively. We explored whether these physical factors influenced rates of primary production and ecosystem respiration, two different metrics of resource availability, in the clear tailwater section of the Colorado River by conducting whole system metabolism measurements across a range of discharge regimes and in reaches with different orientation (i.e. N-S vs. E-W). We found that while both discharge regime and canyon orientation influence rates of primary production, seasonal changes in light availability appear to have a far stronger influence on rates of primary production in the Colorado River. Water temperature appeared to be the main driver of ecosystem respiration.

  20. Early warning of atmospheric regime transitions using transfer operators

    NASA Astrophysics Data System (ADS)

    Tantet, Alexis; Dijkstra, Henk

    2015-04-01

    The existence of persistent midlatitude atmospheric regimes, such as blocking events, with time scales larger than 5-10 days and indications of preferred transition paths between them motivates the development of early-warning indicators of regime transitions. Here, we use a barotropic model of the northern midlatitudes winter flow to study such meta-stable regimes. We look at estimates of transfer operators acting on densities evolving on a reduced phase space spanned by the first Empirical Orthogonal Functions of the streamfunction and develop an early-warning indicator of zonal to blocked flow transition. The study of the spectra of transfer operators estimated for different lags reveals a multi-level structure in the flow as well as the effect of memory on the reduced dynamics due to past interactions between the resolved and unresolved variables. The slowest motions in the reduced phase space are thereby found to have time scales larger than 8 days and to behave as Markovian for larger lags. These motions are associated with meta-stable regimes and their transitions and can be detected as almost-invariant sets of the transfer operator. The early-warning indicator is based on the action on an initial density of products of the transfer operators estimated for sufficiently long lags, making use of the semi-group property of these operators and shows relatively good Peirce skill score. From the energy budget of the model, we are able to explain the meta-stability of the regimes and the existence of preferred transition paths as the manifestation of barotropic instability. Finally, even though the model is highly simplified, the skill of the early warning indicator is promising, suggesting that the transfer operator approach can be used in parallel to an operational deterministic model for stochastic prediction or to assess forecast uncertainty.

  1. Observed river discharge changes due to hydropower operations in the Upper Mekong Basin

    NASA Astrophysics Data System (ADS)

    Räsänen, Timo A.; Someth, Paradis; Lauri, Hannu; Koponen, Jorma; Sarkkula, Juha; Kummu, Matti

    2017-02-01

    The Upper Mekong Basin is undergoing extensive hydropower development and its largest dams have recently become operational. Hydropower is built to improve the regional energy supply, but at the same time, it has considerable transboundary impacts on downstream discharge regime and further on aquatic ecosystems, riparian livelihoods and food security. Despite the transboundary significance of the impacts, there is no public information on the hydropower operations or on the already observed downstream discharge impacts since the completion of the largest dams. Therefore, in this study we assess the discharge changes using observed river discharge data and a distributed hydrological model over the period of 1960-2014. Our findings indicate that the hydropower operations have considerably modified the river discharges since 2011 and the largest changes were observed in 2014. According to observed and simulated discharges, the most notable changes occurred in northern Thailand (Chiang Saen) in March-May 2014 when the discharge increased by 121-187% and in July-August 2014 when the discharge decreased by 32-46% compared to average discharges. The respective changes in Cambodia (Kratie) were 41-74% increase in March-May 2014 and 0-6% decrease in July-August 2014 discharges. The earlier model-based predictions of the discharge changes are well in line with the observed changes, although observed changes are partly larger. The discharge impacts are expected to vary from year to year depending on hydropower operations. Altogether, the results highlight the need for strong transboundary cooperation for managing the downstream impacts.

  2. Nanosecond repetitively pulsed discharges in air at atmospheric pressure—the spark regime

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    Nanosecond repetitively pulsed (NRP) spark discharges have been studied in atmospheric pressure air preheated to 1000 K. Measurements of spark initiation and stability, plasma dynamics, gas temperature and current-voltage characteristics of the spark regime are presented. Using 10 ns pulses applied repetitively at 30 kHz, we find that 2-400 pulses are required to initiate the spark, depending on the applied voltage. Furthermore, about 30-50 pulses are required for the spark discharge to reach steady state, following initiation. Based on space- and time-resolved optical emission spectroscopy, the spark discharge in steady state is found to ignite homogeneously in the discharge gap, without evidence of an initial streamer. Using measured emission from the N2 (C-B) 0-0 band, it is found that the gas temperature rises by several thousand Kelvin in the span of about 30 ns following the application of the high-voltage pulse. Current-voltage measurements show that up to 20-40 A of conduction current is generated, which corresponds to an electron number density of up to 1015 cm-3 towards the end of the high-voltage pulse. The discharge dynamics, gas temperature and electron number density are consistent with a streamer-less spark that develops homogeneously through avalanche ionization in volume. This occurs because the pre-ionization electron number density of about 1011 cm-3 produced by the high frequency train of pulses is above the critical density for streamer-less discharge development, which is shown to be about 108 cm-3.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  4. A frequency tunable relativistic magnetron with a wide operation regime

    NASA Astrophysics Data System (ADS)

    Shi, Di-Fu; Qian, Bao-Liang; Wang, Hong-Gang; Li, Wei; Du, Guang-Xing

    2017-02-01

    A frequency tunable relativistic magnetron (RM) with a wide operation regime is proposed. With the all cavity-magnetron axial extraction technique, the RM can output TEM mode with the operating frequency of 4.3 GHz, which is demonstrated as the dominating output mode by theoretical analysis, cold simulations and hot simulations respectively, corresponding to the output power of 466 MW and the power conversion efficiency of 56.4 %. It also can achieve a wide frequency tuning with the bandwidth of 0.96 GHz and the relative bandwidth of 20.8 %, corresponding to the output power of above 400 MW and the power conversion efficiency of above 40 %. Further simulation results show that the RM has strong performance robustness to the perturbations of the electrical parameters and almost all structural parameters except the cathode radius, anode radius and cavity radius, however two methods proposed in this paper can be taken to further improve the RM performance. The performance robustness enables the RM to operate with a wide parameter regime while keeping a good performance. In addition, a GW-level RM with the power conversion efficiency of 55.9 % also can be obtained.

  5. Study of Operational Regimes of the VASIMR Helicon Plasma Source

    NASA Astrophysics Data System (ADS)

    Batishchev, O.; Molvig, K.

    2000-10-01

    Effective plasma production by a plasma source is crucial for the overall > 50% efficiency of the VASIMR plasma rocket. Primary propellant H (D) - enters the helicon source as cold molecular gas and leaves it as a hot gas-plasma mix. We present an analysis that shows the following plasma composition: e, H_2, H, H^+, H_2^+, H_3^+. Mass and energy balance is described by the 14 non-linear plasma chemistry equations for the species concentrations and temperatures. Their numerical solution shows agreement with the measured electron temperature ~ 6 eV, and density ~ 10^12 cm-3 for both H and D discharges. Simulation shows also that the Ly-α radiation may account for 25%, while Frank-Condon neutrals for 15% of the total input power ~ 1 kW. Gas ionization fraction is ~ 3 - 5% with sizable amount of H_2^+ and H_3^+ ions. However, mass-flow ratio neutral gas/plasma is close to 1 due to the huge difference in the exhaust velocities. A separate numerical analysis of the pure gas flow in the gas inlet - quartz tube - magnet bore channel shows very good agreement with the gas pressure measurements. Modeling indicates that gas flow in the mixed viscous - free molecular regime (Kn ~ 0.5 - 2) is very subsonic with V ~ 0.02 - 0.1 C_S. We discuss effects of gas pre-heating and residual vacuum tank pressure, and importance of baffles.

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  7. Wide-pressure-range coplanar dielectric barrier discharge: Operational characterisation of a versatile plasma source

    NASA Astrophysics Data System (ADS)

    Čech, J.; Bonaventura, Z.; SÅ¥ahel, P.; Zemánek, M.; Dvořáková, H.; Černák, M.

    2017-01-01

    Many plasma applications could benefit from the versatile plasma source operable at a wide-pressure-range, e.g., from the fraction of Pa to the super-atmospheric conditions. In this paper, the basic characteristics of wide-pressure-range plasma source based on the coplanar dielectric barrier discharge is given. The operational characteristics of this plasma source were measured in nitrogen at pressures ranging from 101 Pa (resp. 10-4 Pa) to 105 Pa. Measurements of the plasma geometry, breakdown voltage, and micro-discharges' behaviour revealed three operational regimes of this plasma source: "high pressure," "transitional" and "low-pressure" with vague boundaries at the pressures of approx. 10 kPa and 1 kPa. It was found that the plasma layer of coplanar dielectric barrier discharge could be expanded up to several centimetres to the half-space above the planar dielectric barrier when the gas pressure is reduced below 1 kPa, which provides an outstanding space to tailor the source for the specific applications. The proposed model of an effective gap distance in the Paschen breakdown criterion enabled us to explain the discharge behaviour fitting the experimental breakdown voltage data in the whole studied pressure range. Under the filament-forming conditions, i.e., at the pressure range from approx. 1-100 kPa, the active plasma volume could be varied through the micro-discharges' lateral thickness scaling with the inverse of the square-root of the gas pressure.

  8. Operating regimes for multivalued single-electron tunneling phase logic

    NASA Astrophysics Data System (ADS)

    Li, Tan; Kiehl, Richard A.

    2003-06-01

    The dc bias range and the logic-state lifetime for multivalued single-electron tunneling phase logic are examined in computer simulations. Results for quaternary operation, which is of particular interest for compact logic circuitry, are compared with those for ternary and binary logic. Quaternary logic is shown to exhibit a rotation rule similar to binary and ternary logic and to have an optimized dc bias range of 14%, compared with 20 and 37 % for ternary and binary logic, respectively. The effects of shot noise and Nyquist noise on the logic-state lifetime are strongly influenced by the number of logic states. The ratio of tunnel resistance to series resistance required to suppress the effects of shot noise below those of Nyquist noise depends on the number of logic states. To obtain a lifetime equal to 1000 phase-locked cycles together with a maximum dc bias operating range, the ratio of Coulomb energy to thermal energy Ec/kBT must be 400, 1650, and 2830 for two, three, and four states, respectively. This corresponds to a rapid drop in the maximum operating temperature with the number of states, which can be related to an exponential dependence of lifetime on the activation energy for a thermally activated escape process. The implications of these results on the trade-offs between the operating regimes for dc bias, temperature, and junction size are discussed.

  9. Field-emitting Townsend regime of surface dielectric barrier discharges generated in CO2 emerging at high pressure

    NASA Astrophysics Data System (ADS)

    Pai, David; Stauss, Sven; Terashima, Kazuo

    2015-09-01

    Surface dielectric barrier discharges (DBDs) in CO2 from atmospheric pressure up to supercritical conditions (Tc = 304.13 K, pc = 7.4 MPa) generated using 10-kHz ac excitation are studied experimentally. Two discharge regimes are obtained: the standard and field-emitting Townsend regimes. The former resembles typical surface DBDs that have streamer-like characteristics, but the latter has not been reported previously. Here we present an analysis of the electrical and optical diagnostics of the field-emitting Townsend discharge regime using current-voltage and charge-voltage measurements, imaging, optical emission spectroscopy, and spontaneous Raman spectroscopy. Using an electrical model, it is possible to calculate the discharge-induced capacitances of the plasma and the dielectric, as well as the space-averaged values of the surface potential and the potential drop across the discharge. The model also accounts for the space-averaged Laplacian field by including the capacitance due to the fringe electric field from the electrode edge. The electrical characteristics are similar to those of atmospheric-pressure Townsend DBDs, i.e. self-sustained DBDs with minimal space-charge effects. The purely continuum emission spectrum is due to electron-neutral bremsstrahlung, with a corresponding average electron temperature of 2600 K. Raman spectra of CO2 near the critical point demonstrate that the discharge increases the average gas temperature by less than 1 K. This work was supported financially in part by MEXT and JSPS.

  10. Optimizing Wellfield Operation in a Variable Power Price Regime.

    PubMed

    Bauer-Gottwein, Peter; Schneider, Raphael; Davidsen, Claus

    2016-01-01

    Wellfield management is a multiobjective optimization problem. One important objective has been energy efficiency in terms of minimizing the energy footprint (EFP) of delivered water (MWh/m(3) ). However, power systems in most countries are moving in the direction of deregulated markets and price variability is increasing in many markets because of increased penetration of intermittent renewable power sources. In this context the relevant management objective becomes minimizing the cost of electric energy used for pumping and distribution of groundwater from wells rather than minimizing energy use itself. We estimated EFP of pumped water as a function of wellfield pumping rate (EFP-Q relationship) for a wellfield in Denmark using a coupled well and pipe network model. This EFP-Q relationship was subsequently used in a Stochastic Dynamic Programming (SDP) framework to minimize total cost of operating the combined wellfield-storage-demand system over the course of a 2-year planning period based on a time series of observed price on the Danish power market and a deterministic, time-varying hourly water demand. In the SDP setup, hourly pumping rates are the decision variables. Constraints include storage capacity and hourly water demand fulfilment. The SDP was solved for a baseline situation and for five scenario runs representing different EFP-Q relationships and different maximum wellfield pumping rates. Savings were quantified as differences in total cost between the scenario and a constant-rate pumping benchmark. Minor savings up to 10% were found in the baseline scenario, while the scenario with constant EFP and unlimited pumping rate resulted in savings up to 40%. Key factors determining potential cost savings obtained by flexible wellfield operation under a variable power price regime are the shape of the EFP-Q relationship, the maximum feasible pumping rate and the capacity of available storage facilities.

  11. Analyses of ITER operation mode using the support vector machine technique for plasma discharge classification

    NASA Astrophysics Data System (ADS)

    Lukianitsa, A. A.; Zhdanov, F. M.; Zaitsev, F. S.

    2008-06-01

    A new approach is proposed for classifying tokamak plasma discharges. The method is based on a modern data mining technique—the so-called 'support vector machine', which is able to construct the optimal classifier. The international database of plasma discharges from different tokamaks has been analyzed with respect to H- and L-modes. A new linear equation, which separates H- and L-modes in the space of eight parameters, was obtained allowing us to classify a tokamak pulse as H- or L-mode and to give a quantitative estimate of how deep the pulse is in a mode. The equation also allows calculation of the value of the H-mode threshold for a selected plasma characteristic. The results are applied to ITER parameters. It is shown that in the main regimes ITER should operate deeply in H-mode. A more optimistic than known H-mode loss power threshold prediction is obtained for ITER.

  12. Discharge modes of a DC operated atmospheric pressure air plasma jet

    NASA Astrophysics Data System (ADS)

    Kolb, Juergen; Pei, Xuekai; Kredl, Jana; Lu, Xinpei

    2016-09-01

    By flowing air or nitrogen through a microhollow cathode discharge geometry an afterglow plasma jet can be generated at atmospheric pressure in air. The plasma jet has been successfully used for the inactivation of bacteria and yeast. The responsible reaction chemistry is based on the production of high concentrations of nitric oxide. Production yields depend in particular on gas flow rate and energy dissipated in the plasma. The same parameters also determine different modes of operation for the jet. A true DC operation is achieved for low to moderate gas flow rate of about 1 slm and discharge currents on the order of 10 mA. When increasing the gas flow rate to 10 slm the operation is changing to a self-pulsing mode with characteristics similar to the ones observed for a transient spark. By increasing the current a DC operation can be achieved again also at higher gas flow rates. The parameter regimes for different modes of operation can be described by the reduced electric field E/N.

  13. Analysis of thermionic bare tether operation regimes in passive mode

    NASA Astrophysics Data System (ADS)

    Sanmartín, J. R.; Chen, Xin; Sánchez-Arriaga, G.

    2017-01-01

    A thermionic bare tether (TBT) is a long conductor coated with a low work-function material. In drag mode, a tether segment extending from anodic end A to a zero-bias point B, with the standard Orbital-motion-limited current collection, is followed by a complex cathodic segment. In general, as bias becomes more negative in moving from B to cathodic end C, one first finds space-charge-limited (SCL) emission covering up to some intermediate point B*, then full Richardson-Dushman (RD) emission reaching from B* to end C. An approximate analytical study, which combines the current and voltage profile equations with results from asymptotic studies of the Vlasov-Poisson system for emissive probes, is carried out to determine the parameter domain covering two limit regimes, which are effectively controlled by just two dimensionless parameters involving ambient plasma and TBT material properties. In one such limit regime, no point B* is reached and thus no full RD emission develops. In an opposite regime, SCL segment BB* is too short to contribute significantly to the current balance.

  14. Regime-shifting streamflow processes: Implications for water supply reservoir operations

    NASA Astrophysics Data System (ADS)

    Turner, S. W. D.; Galelli, S.

    2016-05-01

    This paper examines the extent to which regime-like behavior in streamflow time series impacts reservoir operating policy performance. We begin by incorporating a regime state variable into a well-established stochastic dynamic programming model. We then simulate and compare optimized release policies—with and without the regime state variable—to understand how regime shifts affect operating performance in terms of meeting water delivery targets. Our optimization approach uses a Hidden Markov Model to partition the streamflow time series into a small number of separate regime states. The streamflow persistence structures associated with each state define separate month-to-month streamflow transition probability matrices for computing penalty cost expectations within the optimization procedure. The algorithm generates a four-dimensional array of release decisions conditioned on the within-year time period, reservoir storage state, inflow class, and underlying regime state. Our computational experiment is executed on 99 distinct, hypothetical water supply reservoirs fashioned from the Australian Bureau of Meteorology's Hydrologic Reference Stations. Results show that regime-like behavior is a major cause of suboptimal operations in water supply reservoirs; conventional techniques for optimal policy design may misguide the operator, particularly in regions susceptible to multiyear drought. Stationary streamflow models that allow for regime-like behavior can be incorporated into traditional stochastic optimization models to enhance the flexibility of operations.

  15. Experimental analysis on the effects of DC arc discharges at various flow regimes

    SciTech Connect

    Bianchi, G.; Saracoglu, B. H. Regert, T.; Paniagua, G.

    2015-03-15

    This paper addresses the control of the boundary layer on a compression ramp by means of DC electrical arc discharges. The development and realization of the control system are first described and then assessed in the wind tunnel. The objective of the research was to control the supersonic flow using the minimum amount of energy. The array of electrodes was located at the base of a ramp, where a low momentum flow develops. The electrical discharge was generated by a custom designed electronic facility based on high-voltage ignition coils. The slanted tungsten electrodes were insulated by mounting them in a ceramic support. The discharge evolution was studied through high-speed flow visualizations, while electrical measurements at the high-voltage section of the circuitry allowed to estimate the energy release. The development of a high-speed short exposure Schlieren imaging technique, based on a very short duration laser pulse illumination and a double shot CCD camera, allowed to observe the macroscopic effects associated with the arc establishment between the electrodes (glow, sound wave and heat release). Due to the long residence time, the thermal perturbation spread along the streamwise direction. Cross correlation of Schlieren images with short time separation revealed that in supersonic conditions, the discharges led to an overall acceleration of the flow field underneath the oblique shock wave.

  16. Experimental analysis on the effects of DC arc discharges at various flow regimes

    NASA Astrophysics Data System (ADS)

    Bianchi, G.; Saracoglu, B. H.; Paniagua, G.; Regert, T.

    2015-03-01

    This paper addresses the control of the boundary layer on a compression ramp by means of DC electrical arc discharges. The development and realization of the control system are first described and then assessed in the wind tunnel. The objective of the research was to control the supersonic flow using the minimum amount of energy. The array of electrodes was located at the base of a ramp, where a low momentum flow develops. The electrical discharge was generated by a custom designed electronic facility based on high-voltage ignition coils. The slanted tungsten electrodes were insulated by mounting them in a ceramic support. The discharge evolution was studied through high-speed flow visualizations, while electrical measurements at the high-voltage section of the circuitry allowed to estimate the energy release. The development of a high-speed short exposure Schlieren imaging technique, based on a very short duration laser pulse illumination and a double shot CCD camera, allowed to observe the macroscopic effects associated with the arc establishment between the electrodes (glow, sound wave and heat release). Due to the long residence time, the thermal perturbation spread along the streamwise direction. Cross correlation of Schlieren images with short time separation revealed that in supersonic conditions, the discharges led to an overall acceleration of the flow field underneath the oblique shock wave.

  17. ATC contingency operations in the en-route flight regime

    NASA Technical Reports Server (NTRS)

    Lyman, E. G.

    1981-01-01

    Air traffic control (ATC) operations were examined to learn what factors of controller performance should be given consideration in the design and development of future automation systems enhancing ATC. Contingencies were of two types: those constraining airspace usage or traffic flow (i.e., weather); and those related to system and equipment usage (i.e., radar/radio status). Examination of controller response to contingencies and workload pressures showed differing effects on controller allocations of effort among the three primary function of planning, monitoring, and informaton transfer. Automation advancements oriented towards aiding the controller in performing monitoring tasks may offer the most substantial safety benefit.

  18. Development of a Discharge Channel upon Electric Explosion of a Wire in Interrupted- and Uninterrupted-Current Regimes

    SciTech Connect

    Romanova, Vera; Tkachenko, Svetlana; Mingaleev, Albert; Agafonov, Alexey; Ter-Oganesyan, Alexey; Shelkovenko, Tatiana; Pikuz, Sergey

    2009-01-21

    Experimental results on the electrical explosion of thin W, Cu and Ni wires with a current density of {approx}10{sup 12} A/m{sup 2}, a current rise rate (dI/dt){approx}40 A/ns and a current pulse with amplitude 9 kA are presented. The structures of the discharge channels developed in single wire explosions in air and vacuum using laser shadow and schlieren imaging have been studied under the condition that the current in the circuit was interrupted. A difference in the shock wave propagation in air and the expansion of the exploded wire dense core in interrupted- and uninterrupted-current regimes has been observed. Analysis of the optical images has been performed in a shunting breakdown scenario.

  19. Two-wave regime of operation of the high-harmonic gyrotron

    SciTech Connect

    Savilov, A. V.; Denisov, G. G.; Kalynov, Yu. K.; Osharin, I. V.

    2015-04-15

    The use of the two-wave co-generation is proposed as a way to decrease the effective Q-factor of the operating near-cutoff wave of the gyrotron. In this two-wave regime, the operating wave represents a “hot” wave mode formed by two partial “cold” modes (near-cutoff and far-from-cutoff ones) coupled on the electron beam. It is shown that the use of this regime can provide a significant decrease of the Ohmic losses in low-relativistic high-harmonic gyrotrons operating in the THz frequency range.

  20. Two simultaneous operating regimes in an Erbium doped-fiber laser

    NASA Astrophysics Data System (ADS)

    Demori, C. B. S.; Thoroh de Souza, E. A.

    2015-06-01

    This work presents an Erbium doped fiber laser operating simultaneously in two distinct regimes, active mode-locking and continuous wave (CW), by introducing two arrayed waveguide gratings (AWG) paired inside ring cavity. Active phase modulator operating at 10 GHz and a single mode fiber were introduced between the two AWGs to allow the two operating regimes. The mode-locking was able to generated pulses with 30 ps simultaneous with the CW line. Both lasers could be tunable independent and simultaneously from 1530 nm to 1565 nm.

  1. Post-operative Seroma Causing Spontaneous Nipple Discharge: Diagnosis by Galactography

    PubMed Central

    Ramirez-Hernandez, Ivan E.; Hardman, Rulon L.; Kirkpatrick, Aaron D.; Sutcliffe, Joseph

    2013-01-01

    Nipple discharge is a common breast complaint in women. Discharge in the post-operative patient for breast cancer is especially concerning, as these women are at higher risk for recurrent or new breast cancer. Galactography is a reliable method to evaluate nipple discharge, attempting to identify a mass that may cause the discharge within the duct of concern. We present two cases of women with spontaneous nipple discharge after lumpectomy for breast cancer. In both cases, evaluation with galactography demonstrated a post-operative seroma that communicated with a native breast duct, causing nipple discharge. This presentation of a post-operative seroma is important to recognize by breast surgeons and breast imagers. Galactography can play an important role in the work up of these patients, demonstrating etiology of the nipple discharge with greater confidence than other imaging modalities. PMID:23705053

  2. Discharge regime of non-ambipolarity with a self-induced steady-state magnetic field in plasma sources with localized radio-frequency power deposition

    SciTech Connect

    Shivarova, A. Lishev, St.; Todorov, D.; Paunska, Ts.

    2015-10-15

    Involving the idea for the Biermann effect known from space physics as well as recent discussions on non-ambipolarity of the electron and ion fluxes in low-pressure discharges, the study builds the discharge pattern in a source with localized RF power deposition outside the region of high electron density. A vortex dc current flowing in an RF discharge and a steady-state magnetic field induced by this current govern the discharge behavior. Owing to a shift in the positions of the electron-density and plasma-potential maxima, the dc current is driven with the purpose of keeping the conservativity of the dc field in the discharge. The results present the spatial structure of a discharge in a regime of non-ambipolarity of the electron and ion fluxes, including its modifications by the magnetic field.

  3. Evaluation of nickel-yttria stabilized zirconia anode degradation during discharge operation and redox cycles operation by electrochemical calculation

    NASA Astrophysics Data System (ADS)

    Shimura, Takaaki; Jiao, Zhenjun; Shikazono, Naoki

    2016-10-01

    Degradation of Solid Oxide Fuel Cell (SOFC) anode during discharge operation and redox cycles operation were evaluated by three-dimensional electrochemical calculations using a Lattice Boltzmann method (LBM). Three dimensional microstructures were obtained by Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) reconstruction. In the electrochemical calculations, changes in exchange current density and ionic conductivity of Yttria stabilized Zirconia (YSZ) during the operations were assumed and their values were calculated by fitting the calculated overpotential values to the experimental ones. Changes in triple phase boundary density calculated from the reconstructed microstructures were inconsistent with the gradual degradation observed during repeated redox-discharge cycles. Changes of the fitted exchange current density and YSZ ionic conductivity values in both discharge operation and redox cycle operation showed same tendency as the experimental results. Change in exchange current density or YSZ ionic conductivity should be considered as an essential factor which governs the cell performance change regardless of the redox treatment.

  4. High-energy femtosecond Yb-doped fiber laser operating in the anomalous dispersion regime.

    PubMed

    Ortaç, Bülend; Limpert, Jens; Tünnermann, Andreas

    2007-08-01

    We report on high-energy ultrashort pulse generation from a passively mode-locked ytterbium-doped large-mode-area photonic crystal fiber oscillator operating in the anomalous dispersion regime. In the single-pulse regime, the laser directly generates 880 mW of average power of sub-500 fs pulses at a repetition rate of 53.33 MHz, corresponding to a pulse energy of 16.5 nJ. Stable and self-starting operation is obtained by adapting the spot size at the saturable absorber mirror to the pulse evolution in the low-nonlinearity fiber. The approach presented demonstrates the scaling potential of fiber based short pulse oscillators towards the microJ-level.

  5. High energy bursts from a solid state laser operated in the heat capacity limited regime

    DOEpatents

    Albrecht, Georg; George, E. Victor; Krupke, William F.; Sooy, Walter; Sutton, Steven B.

    1996-01-01

    High energy bursts are produced from a solid state laser operated in a heat capacity limited regime. Instead of cooling the laser, the active medium is thermally well isolated. As a result, the active medium will heat up until it reaches some maximum acceptable temperature. The waste heat is stored in the active medium itself. Therefore, the amount of energy the laser can put out during operation is proportional to its mass, the heat capacity of the active medium, and the temperature difference over which it is being operated. The high energy burst capacity of a heat capacity operated solid state laser, together with the absence of a heavy, power consuming steady state cooling system for the active medium, will make a variety of applications possible. Alternately, cooling takes place during a separate sequence when the laser is not operating. Industrial applications include new material working processes.

  6. High energy bursts from a solid state laser operated in the heat capacity limited regime

    DOEpatents

    Albrecht, G.; George, E.V.; Krupke, W.F.; Sooy, W.; Sutton, S.B.

    1996-06-11

    High energy bursts are produced from a solid state laser operated in a heat capacity limited regime. Instead of cooling the laser, the active medium is thermally well isolated. As a result, the active medium will heat up until it reaches some maximum acceptable temperature. The waste heat is stored in the active medium itself. Therefore, the amount of energy the laser can put out during operation is proportional to its mass, the heat capacity of the active medium, and the temperature difference over which it is being operated. The high energy burst capacity of a heat capacity operated solid state laser, together with the absence of a heavy, power consuming steady state cooling system for the active medium, will make a variety of applications possible. Alternately, cooling takes place during a separate sequence when the laser is not operating. Industrial applications include new material working processes. 5 figs.

  7. The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmas [The quiescent H-mode regime for high performance ELM-stable operation in future burning plasmas

    SciTech Connect

    Garofalo, Andrea M.; Burrell, Keith H.; Eldon, David; Grierson, Brian A.; Hanson, Jeremy M.; Holland, Christopher; Huijsmans, Guido T. A.; Liu, Feng; Loarte, Alberto; Meneghini, Orso; Osborne, T. H.; Paz-Soldan, C.; Smith, S. P.; Snyder, P. B.; Solomon, W. M.; Turnbull, A. D.; Zeng, L.

    2015-05-26

    For the first time, DIII-D experiments have achieved stationary quiescent H-mode (QH-mode) operation for many energy confinement times at simultaneous ITER-relevant values of beta, confinement, and safety factor, in an ITER similar shape. QH-mode provides excellent energy confinement, even at very low plasma rotation, while operating without edge localized modes (ELMs) and with strong impurity transport via the benign edge harmonic oscillation (EHO). By tailoring the plasma shape to improve the edge stability, the QH-mode operating space has also been extended to densities exceeding 80% of the Greenwald limit, overcoming the long-standing low-density limit of QH-mode operation. In the theory, the density range over which the plasma encounters the kink-peeling boundary widens as the plasma cross-section shaping is increased, thus increasing the QH-mode density threshold. Here, the DIII-D results are in excellent agreement with these predictions, and nonlinear MHD analysis of reconstructed QH-mode equilibria shows unstable low n kink-peeling modes growing to a saturated level, consistent with the theoretical picture of the EHO. Furthermore, high density operation in the QH-mode regime has opened a path to a new, previously predicted region of parameter space, named “Super H-mode” because it is characterized by very high pedestals that can be more than a factor of two above the peeling-ballooning stability limit for similar ELMing H-mode discharges at the same density.

  8. The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmas [The quiescent H-mode regime for high performance ELM-stable operation in future burning plasmas

    DOE PAGES

    Garofalo, Andrea M.; Burrell, Keith H.; Eldon, David; ...

    2015-05-26

    For the first time, DIII-D experiments have achieved stationary quiescent H-mode (QH-mode) operation for many energy confinement times at simultaneous ITER-relevant values of beta, confinement, and safety factor, in an ITER similar shape. QH-mode provides excellent energy confinement, even at very low plasma rotation, while operating without edge localized modes (ELMs) and with strong impurity transport via the benign edge harmonic oscillation (EHO). By tailoring the plasma shape to improve the edge stability, the QH-mode operating space has also been extended to densities exceeding 80% of the Greenwald limit, overcoming the long-standing low-density limit of QH-mode operation. In the theory,more » the density range over which the plasma encounters the kink-peeling boundary widens as the plasma cross-section shaping is increased, thus increasing the QH-mode density threshold. Here, the DIII-D results are in excellent agreement with these predictions, and nonlinear MHD analysis of reconstructed QH-mode equilibria shows unstable low n kink-peeling modes growing to a saturated level, consistent with the theoretical picture of the EHO. Furthermore, high density operation in the QH-mode regime has opened a path to a new, previously predicted region of parameter space, named “Super H-mode” because it is characterized by very high pedestals that can be more than a factor of two above the peeling-ballooning stability limit for similar ELMing H-mode discharges at the same density.« less

  9. Control of Oxygen Delamination in Solid Oxide Electrolyzer Cells via Modifying Operational Regime

    SciTech Connect

    Sergey N. Rashkeev; Michael V. Glazoff

    2011-10-01

    Possible modifications of operational regimes for solid oxide fuel cell (SOEC) devices for hydrogen production are discussed. It is shown that applying alternating current (AC) voltage pulses at a certain frequency range to SOECs could reduce oxygen delamination degradation in these devices and significantly increase their lifetime. This operational scheme provides wide possibilities to increase longevity of SOEC devices required for their use in commercial hydrogen production processes, without any significant modification of used materials and/or cell design. Developed simulation method possesses a broad generality and be employed in a number of other industrial processes.

  10. Terahertz generation in GaN diodes operating in pulsed regime limited by self-heating

    NASA Astrophysics Data System (ADS)

    Barry, E. A.; Sokolov, V. N.; Kim, K. W.; Trew, R. J.

    2009-06-01

    The conditions for pulsed regime operation of terahertz power generation in vertical nanoscale GaN-based diodes are investigated via self-consistent simulation of the high-field electron transport in the active channel and thermal transport in the entire device structure. The combined electrothermal model allows for a detailed analysis of the dynamical local distributions of the electric field, drift-velocity, and lattice temperature. We show that stable generation is achievable with a self-heating limited output power of 2.25 W at an operation frequency of 0.71 THz for a pulse width of 3 ns with a few tens of nanosecond duty cycle.

  11. Administrative aspects of a general surgical firm: an audit of accuracy of operation lists and timeliness of discharge summaries.

    PubMed

    Aziz, M M; Corder, A P

    1996-07-01

    A one-year audit of operation lists and discharge summaries of one surgical firm showed only 1.4 percent of operation lists contained errors or omissions and only 5 percent contained abbreviations. 74.2 percent of discharge summaries were dictated within one week of discharge. A high proportion of day cases allowed 44.7 percent of the discharge summaries to be dictated on the day of operation. Close consultant and secretarial involvement in the preparation of operating lists can ensure a high degree of accuracy. Day case operation notes should be combined with a discharge letter to optimise communication with general practitioners.

  12. Enhancement of the EUV emission of a metallic capillary discharge operated with argon ambient gas

    SciTech Connect

    Chan, L. S. Tan, D. Saboohi, S. Yap, S. L. Wong, C. S.

    2014-03-05

    In this work, the metallic capillary discharge is operated with two different ambients: air and argon. In the experiments reported here, the chamber is first evacuated to 10{sup −5} mbar. The discharge is initiated by the transient hollow cathode effect generated electron beam, with either air ambient or argon ambient at 10{sup −4} mbar. The bombardment of electron beam at the tip of the stainless steel anode gives rise to a metallic vapor, which is injected into the capillary and initiates the main discharge through the capillary. The EUV emission is measured for different discharge voltages for both conditions and compared. It is found that the metallic capillary discharge with argon ambientis able to produce higher EUV energy compared to that with air ambient.

  13. A New Look at the GEO and Near-GEO Regimes: Operations, Disposals, and Debris

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas

    2011-01-01

    Since 1963 more than 900 spacecraft and more than 200 launch vehicle upper stages have been inserted into the vicinity of the geosynchronous regime. Equally important, more than 300 spacecraft have been maneuvered into disposal orbits at mission termination to alleviate unnecessary congestion in the finite GEO region. However, the number of GEO satellites continues to grow, and evidence exists of a substantial small debris population. In addition, the operational modes of an increasing number of GEO spacecraft differ from those of their predecessors of several decades ago, including more frequent utilization of inclined and eccentric geosynchronous orbits. Consequently, the nature of the GEO regime and its immediate surroundings is evolving from well-known classical characteristics. This paper takes a fresh look at the GEO satellite population and the near- and far-term environmental implications of the region, including the effects of national and international debris mitigation measures.

  14. 20 CFR 726.207 - Discharge by the carrier of obligations and duties of operator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Discharge by the carrier of obligations and... obligations and duties of operator. Every obligation and duty in respect of payment of benefits, the providing.... Jurisdiction of the operator by a district director, administrative law judge, the Office, or...

  15. Prospects for CW and LP operation of the European XFEL in hard X-ray regime

    NASA Astrophysics Data System (ADS)

    Brinkmann, R.; Schneidmiller, E. A.; Sekutowicz, J.; Yurkov, M. V.

    2014-12-01

    The European XFEL will operate nominally at 17.5 GeV in SP (short pulse) mode with 0.65 ms long bunch train and 10 Hz repetition rate. A possible upgrade of the linac to CW (continuous wave) or LP (long pulse) modes with a corresponding reduction of electron beam energy is under discussion for many years. Recent successes in the dedicated R&D program allow to forecast a technical feasibility of such an upgrade in the foreseeable future. One of the challenges is to provide sub-Ångström FEL operation in CW and LP modes. In this paper we perform a preliminary analysis of a possible operation of the European XFEL in the hard X-ray regime in CW and LP modes with electron energies of 7 GeV and 10 GeV, respectively. We consider lasing in the baseline XFEL undulator as well as in a new undulator with a reduced period. We show that, with reasonable requirements on electron beam quality, lasing on the fundamental will be possible in the sub-Ångström regime. As an option for generating brilliant photon beams at short wavelengths we also consider harmonic lasing that has recently attracted a significant attention.

  16. Study of the operational properties of the Capillary Plasma Electrode (CPE) discharges

    NASA Astrophysics Data System (ADS)

    Lopez, Jose; Jacome, David; Zhu, Wei-Dong; Figus, Margaret; Becker, Kurt H.

    2009-03-01

    Various approaches have been pursued to create stable atmospheric pressure discharges by extending the lifetime of the diffuse phase of the discharge to hundreds of microseconds. Previous research showed that the stability of the diffuse mode is dependent on the frequency (in the kHz range), gas type power, mode of the excitation, and geometrical confinement. Some of the most promising approaches are based on the recognition of the arc formation in high-pressure plasmas can be avoided and stable high-pressure plasma can be generated and maintained when the plasma are spatially constricted to the dimensions of tens to hundreds of microns. The Capillary Plasma Electrode (CPE) discharge is stable to produce stable atmospheric pressure nonequilibrium plasma. The CPE is similar in design to the Barrier Electrode Discharge, but has perforated dielectrics. The configuration, aside from exhibiting a diffuse mode of operation, also exhibits the so-called ``capillary jet'' mode, in which the capillaries “turn on” and a bright plasma jet emerges from the capillaries. The capillary jets from adjacent capillaries overlap so that the discharge appears uniform when the electrode contains an array of holes. There appears to be a threshold frequency for the capillary jet formation, which is strongly dependent on the L/D ratio of the capillaries, where D is diameter of the capillary and L its length. However, the operating principles and basic properties of this behavior are not well understood. The current work explores these modes of operations of the CPE by characterizing the electrical and optical emission properties of this discharge by examining a multi-hole discharge as well as a single capillary discharge reactor.

  17. Validation of mathematical models for predicting the swirling flow and the vortex rope in a Francis turbine operated at partial discharge

    NASA Astrophysics Data System (ADS)

    Kuibin, P. A.; Okulov, V. L.; Susan-Resiga, R. F.; Muntean, S.

    2010-08-01

    The vortex rope in a hydro turbine draft tube is one the main and strong sources of pulsations in non-optimal modes of hydro turbine operation. We examine the case of a Francis turbine model operated at partial discharge, where a strong precessing vortex rope is developed in the discharge cone downstream the runner. Available experimental data provide the circumferentially averaged axial and circumferential velocity profiles, as well as the vortex rope geometry, precessing frequency, and the level of pressure fluctuation at the wall. The mathematical models presented in this paper can correctly recover all this information without actually computing the full three-dimensional unsteady flow in the hydraulic turbine. As a result, we provide valuable mathematical tools for assessing the turbine behaviour at off-design operating regimes in the early stages of runner design, with computational effort several orders of magnitude less than the current approaches of simulating the complex turbine flow.

  18. ZnO Nanowire-Based Corona Discharge Devices Operated Under Hundreds of Volts

    NASA Astrophysics Data System (ADS)

    Yang, Wenming; Zhu, Rong; Zong, Xianli

    2016-02-01

    Minimizing the voltage of corona discharges, especially when using nanomaterials, has been of great interest in the past decade or so. In this paper, we report a new corona discharge device by using ZnO nanowires operated in atmospheric air to realize continuous corona discharge excited by hundreds of volts. ZnO nanowires were synthesized on microelectrodes using electric-field-assisted wet chemical method, and a thin tungsten film was deposited on the microchip to enhance discharging performance. The testing results showed that the corona inception voltages were minimized greatly by using nanowires compared to conventional dischargers as a result of the local field enhancement of nanowires. The corona could be continuously generated and self-sustaining. It was proved that the law of corona inception voltage obeyed the conventional Peek's breakdown criterion. An optimal thickness of tungsten film coated over ZnO nanowires was figured out to obtain the lowest corona inception voltage. The ion concentration of the nanowire-based discharger attained 1017/m3 orders of magnitude, which is practicable for most discharging applications.

  19. ZnO Nanowire-Based Corona Discharge Devices Operated Under Hundreds of Volts.

    PubMed

    Yang, Wenming; Zhu, Rong; Zong, Xianli

    2016-12-01

    Minimizing the voltage of corona discharges, especially when using nanomaterials, has been of great interest in the past decade or so. In this paper, we report a new corona discharge device by using ZnO nanowires operated in atmospheric air to realize continuous corona discharge excited by hundreds of volts. ZnO nanowires were synthesized on microelectrodes using electric-field-assisted wet chemical method, and a thin tungsten film was deposited on the microchip to enhance discharging performance. The testing results showed that the corona inception voltages were minimized greatly by using nanowires compared to conventional dischargers as a result of the local field enhancement of nanowires. The corona could be continuously generated and self-sustaining. It was proved that the law of corona inception voltage obeyed the conventional Peek's breakdown criterion. An optimal thickness of tungsten film coated over ZnO nanowires was figured out to obtain the lowest corona inception voltage. The ion concentration of the nanowire-based discharger attained 10(17)/m(3) orders of magnitude, which is practicable for most discharging applications.

  20. Characterization of the Basic Operational Properties of the Capillary Plasma Electrode (CPE) Discharge

    NASA Astrophysics Data System (ADS)

    Lopez, Jose; Zhu, Weidong; Figus, Margaret; Becker, Kurt

    2008-10-01

    Various approaches have been pursued to create stable atmospheric pressure discharges by extending the lifetime of the diffuse phase of the discharge to hundreds of microseconds. Previous research showed that the stability of the diffuse mode is dependent on the frequency (in the kHz range), gas type, power, mode of the excitation, and geometrical confinement. The Capillary Plasma Electrode (CPE) discharge is able to produce stable atmospheric pressure nonequilibrium plasmas. The CPE is similar in design to a barrier-electrode discharge, but has perforated dielectrics. This configuration, aside from exhibiting a diffuse mode of operation, also exhibits the so-called ``capillary jet'' mode, in which the capillaries ``turn on'' and a bright plasma jet emerges from the capillaries. The capillary jets from adjacent capillaries overlap so that the discharge appears uniform when the electrode contains an array of holes. There appears to be a threshold frequency for the capillary jet formation, which is strongly dependent on the L/D ratio of the capillaries, where D is the diameter of a capillary and L its length. This current work explores these modes of operation of the CPE by characterizing the electrical and optical emission properties of this discharge.

  1. Operation of a titanium nitride superconducting microresonator detector in the nonlinear regime

    NASA Astrophysics Data System (ADS)

    Swenson, L. J.; Day, P. K.; Eom, B. H.; Leduc, H. G.; Llombart, N.; McKenney, C. M.; Noroozian, O.; Zmuidzinas, J.

    2013-03-01

    If driven sufficiently strongly, superconducting microresonators exhibit nonlinear behavior including response bifurcation. This behavior can arise from a variety of physical mechanisms including heating effects, grain boundaries or weak links, vortex penetration, or through the intrinsic nonlinearity of the kinetic inductance. Although microresonators used for photon detection are usually driven fairly hard in order to optimize their sensitivity, most experiments to date have not explored detector performance beyond the onset of bifurcation. Here, we present measurements of a lumped-element superconducting microresonator designed for use as a far-infrared detector and operated deep into the nonlinear regime. The 1 GHz resonator was fabricated from a 22 nm thick titanium nitride film with a critical temperature of 2 K and a normal-state resistivity of 100 μΩ cm. We measured the response of the device when illuminated with 6.4 pW optical loading using microwave readout powers that ranged from the low-power, linear regime to 18 dB beyond the onset of bifurcation. Over this entire range, the nonlinear behavior is well described by a nonlinear kinetic inductance. The best noise-equivalent power of 2×10-16 W/Hz1/2 at 10 Hz was measured at the highest readout power, and represents a ˜10 fold improvement compared with operating below the onset of bifurcation.

  2. Parametric system identification of resonant micro/nanosystems operating in a nonlinear response regime

    NASA Astrophysics Data System (ADS)

    Sabater, A. B.; Rhoads, J. F.

    2017-02-01

    The parametric system identification of macroscale resonators operating in a nonlinear response regime can be a challenging research problem, but at the micro- and nanoscales, experimental constraints add additional complexities. For example, due to the small and noisy signals micro/nanoresonators produce, a lock-in amplifier is commonly used to characterize the amplitude and phase responses of the systems. While the lock-in enables detection, it also prohibits the use of established time-domain, multi-harmonic, and frequency-domain methods, which rely upon time-domain measurements. As such, the only methods that can be used for parametric system identification are those based on fitting experimental data to an approximate solution, typically derived via perturbation methods and/or Galerkin methods, of a reduced-order model. Thus, one could view the parametric system identification of micro/nanosystems operating in a nonlinear response regime as the amalgamation of four coupled sub-problems: nonparametric system identification, or proper experimental design and data acquisition; the generation of physically consistent reduced-order models; the calculation of accurate approximate responses; and the application of nonlinear least-squares parameter estimation. This work is focused on the theoretical foundations that underpin each of these sub-problems, as the methods used to address one sub-problem can strongly influence the results of another. To provide context, an electromagnetically transduced microresonator is used as an example. This example provides a concrete reference for the presented findings and conclusions.

  3. Enhanced focus steering abilities of multi-element therapeutic arrays operating in nonlinear regimes

    SciTech Connect

    Yuldashev, P. Ilyin, S.; Gavrilov, L.; Sapozhnikov, O.; Khokhlova, V.; Kreider, W.

    2015-10-28

    Steering abilities of a typical HIFU therapeutic array operated in linear and nonlinear regimes were compared using numerical simulation with the 3D Westervelt equation. The array included 256 elements of 1.2 MHz frequency and 6.6 mm diameter distributed in a quasi-random pattern over a spherical shell with a 130 mm aperture and a focal length of 120 mm. In the case of linear focusing, thermal effects are proportional to the intensity level and the criterion for safe array operation is that the intensity in the grating lobes should be less than 10% of the intensity in the main focus. In the case of nonlinear focusing, the heating effect is no longer proportional to intensity; therefore the heat deposition rate was chosen as the relevant metric, using the same 10% threshold for the secondary lobe in comparison with the focal maximum. When steering the focus, the same linearly predicted intensity level at the main focus was maintained by increasing the array power. Numerical simulations of the acoustic field were performed for nonlinear propagation both in water and in tissue. It was shown that for shock-forming conditions in the main focus, the steering range of safe electronic focusing is larger than that for linear propagation conditions. Nonlinear sonication regimes therefore can be used to enlarge tissue volumes that can be sonicated using electronic steering of the focus of HIFU arrays.

  4. Basal Resources in Backwaters of the Colorado River Below Glen Canyon Dam-Effects of Discharge Regimes and Comparison with Mainstem Depositional Environments

    USGS Publications Warehouse

    Behn, Katherine E.; Kennedy, Theodore A.; Hall, Robert O.

    2010-01-01

    Eight species of fish were native to the Colorado River before the closure of Glen Canyon Dam, but only four of these native species are currently present. A variety of factors are responsible for the loss of native fish species and the limited distribution and abundance of those that remain. These factors include cold and constant water temperatures, predation and competition with nonnative fish species, and food limitation. Backwaters are areas of stagnant flow in a return-current channel and are thought to be critical rearing habitat for juvenile native fish. Backwaters can be warmer than the main channel and may support higher rates of food production. Glen Canyon Dam is a peaking hydropower facility and, as a result, has subdaily variation in discharge because of changes in demand for power. Stable daily discharges may improve the quality of nearshore rearing habitats such as backwaters by increasing warming, stabilizing the substrate, and increasing food production. To evaluate whether backwaters have greater available food resources than main-channel habitats, and how resource availability in backwaters is affected by stable flow regimes, we quantified water-column and benthic food resources in backwaters seasonally for 1 year using both standing (organic matter concentration/density; chlorophyll a concentration/density; zooplankton concentration; benthic invertebrate density and biomass) and process measurements (chamber estimates of ecosystem metabolism). We compared backwater resource measurements with comparable data from main-channel habitats, and compared backwater data collected during stable discharge with data collected when there was subdaily variation in discharge. Rates of primary production in backwaters (mean gross primary production of 1.7 g O2/m2/d) and the main channel (mean gross primary production of 2.0 g O2/m2/d) were similar. Benthic organic matter standing stock (presented as ash-free dry mass-AFDM) was seven times higher in backwaters

  5. Operating Modes and Power Considerations of Microhollow Cathode Discharge Devices with Elongated Trenches

    DTIC Science & Technology

    2012-01-24

    of these MHCDs for micro- plasma reforming applications, providing insights into operational modes and power consumption estimates critical to...hydrocarbon reforming technology. Here we report on the electrical phenomena resulting from MHCD devices with elongated trenches using argon at...P.O. Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS Microplasma, Nonthermal plasma , Microhollow cathode discharge, Self-pulsing

  6. 20 CFR 726.207 - Discharge by the carrier of obligations and duties of operator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Discharge by the carrier of obligations and duties of operator. 726.207 Section 726.207 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, AS AMENDED BLACK LUNG...

  7. 20 CFR 726.207 - Discharge by the carrier of obligations and duties of operator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Discharge by the carrier of obligations and duties of operator. 726.207 Section 726.207 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, AS AMENDED BLACK LUNG...

  8. 20 CFR 726.207 - Discharge by the carrier of obligations and duties of operator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Discharge by the carrier of obligations and duties of operator. 726.207 Section 726.207 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, AS AMENDED BLACK LUNG...

  9. Flood frequency analysis and discussion of non-stationarity of the Lower Rhine flooding regime (AD 1350-2011): Using discharge data, water level measurements, and historical records

    NASA Astrophysics Data System (ADS)

    Toonen, W. H. J.

    2015-09-01

    Accurate estimates of the recurrence time of extreme floods are essential to assess flood safety in flood-prone regions, such as the Lower Rhine in The Netherlands. Measured discharge records have a limited length and are, in general, poorly representing extremes, which results in considerable uncertainties when used for flood frequency analysis. In this paper, it is shown how alternative discharge monitoring stations along the Rhine, measurements of water levels, and historical records can be used to increase data availability. Although pre-processing and the conversion of data types into discharge estimates introduces extra uncertainty, the added value of this data in flood frequency analysis is considerable, because extending record length by including slightly less-precise data results in much better constrained estimates for the discharges and recurrence intervals of extreme events. Based on results obtained with the Generalised Extreme Value (GEV) distribution, it was concluded that large floods of the last century are presumably rarer than previously considered using shorter data series. Moreover, the combined effect of climatic and anthropogenic-induced non-stationarities of the flooding regime is more easily recognised in extended records. It is shown that non-stationarities have a significant effect on the outcomes of flood frequency analysis using both short and long input data series. Effects on outcomes of dominant multi-decadal variability are, however, largely subdued in the longer 240-year series.

  10. Operation of a Solid-Rod Cathode in a Low-Pressure Discharge

    NASA Technical Reports Server (NTRS)

    Goodfellow, K. D.

    1996-01-01

    Cathode erosion is one of the life-limiting mechanisms in several classes of electric thrusters. Since cathode erosion depends strongly on the cathode temperature, a quantitative understanding of the effects of cathode operation in the cathode temperature is required. A pure tungsten cathode was sucessfully operated in an argon discharge at pressures of 1.5 and 3.0 kPa and current levels of 600, 1000 and 1400 A.

  11. Microbubble generation in a co-flow device operated in a new regime.

    PubMed

    Castro-Hernández, Elena; van Hoeve, Wim; Lohse, Detlef; Gordillo, José M

    2011-06-21

    A new regime of operation of PDMS-based flow-focusing microfluidic devices is presented. We show that monodisperse microbubbles with diameters below one-tenth of the channel width (here w = 50 μm) can be produced in low viscosity liquids thanks to a strong pressure gradient in the entrance region of the channel. In this new regime bubbles are generated at the tip of a long and stable gas ligament whose diameter, which can be varied by tuning appropriately the gas and liquid flow rates, is substantially smaller than the channel width. Through this procedure the volume of the bubbles formed at the tip of the gas ligament can be varied by more than two orders of magnitude. The experimental results for the bubble diameter d(b) as function of the control parameters are accounted for by a scaling theory, which predicts d(b)/w ∝ (μ(g)/μ(l))(1/12)(Q(g)/Q(l))(5/12), where μ(g) and μ(l) indicate, respectively, the gas and liquid viscosities and Q(g) and Q(l) are the gas and liquid flow rates. As a particularly important application of our results we produce monodisperse bubbles with the appropriate diameter for therapeutic applications (d(b) ≃ 5 μm) and a production rate exceeding 10(5) Hz.

  12. Operation regimes and electrical transport of steep slope Schottky Si-FinFETs

    NASA Astrophysics Data System (ADS)

    Jeon, Dae-Young; Zhang, Jian; Trommer, Jens; Park, So Jeong; Gaillardon, Pierre-Emmanuel; De Micheli, Giovanni; Mikolajick, Thomas; Weber, Walter M.

    2017-02-01

    In the quest for energy efficient circuits, considerable focus has been given to steep slope and polarity-controllable devices, targeting low supply voltages and reduction of transistor count. The recently proposed concept of the three-independent gated Si-FinFETs with Schottky-barriers (SBs) has proven to bring both functionalities even in a single device. However, the complex combination of transport properties including Schottky emission and weak impact ionization as well as the body effect makes the design of such devices challenging. In this work, we perform a deep electrical characterization analysis to visualize and decouple the different operation regimes and electrical properties of the SB Si-FinFETs using a graphical transport map. From these, we give important guidelines for the design of future devices.

  13. A new high performance field reversed configuration operating regime in the C-2 device

    SciTech Connect

    Tuszewski, M.; Smirnov, A.; Thompson, M. C.; Barnes, D.; Binderbauer, M. W.; Brown, R.; Bui, D. Q.; Clary, R.; Conroy, K. D.; Deng, B. H.; Dettrick, S. A.; Douglass, J. D.; Garate, E.; Glass, F. J.; Gota, H.; Guo, H.Y.; Gupta, D.; Gupta, S.; Kinley, J. S.; Knapp, K.; and others

    2012-05-15

    Large field reversed configurations (FRCs) are produced in the C-2 device by combining dynamic formation and merging processes. The good confinement of these FRCs must be further improved to achieve sustainment with neutral beam (NB) injection and pellet fuelling. A plasma gun is installed at one end of the C-2 device to attempt electric field control of the FRC edge layer. The gun inward radial electric field counters the usual FRC spin-up and mitigates the n = 2 rotational instability without applying quadrupole magnetic fields. Better plasma centering is also obtained, presumably from line-tying to the gun electrodes. The combined effects of the plasma gun and of neutral beam injection lead to the high performance FRC operating regime, with FRC lifetimes up to 3 ms and with FRC confinement times improved by factors 2 to 4.

  14. Stress predictions in a Francis turbine at no-load operating regime

    NASA Astrophysics Data System (ADS)

    Morissette, JF; Chamberland-Lauzon, J.; Nennemann, B.; Monette, C.; Giroux, AM; Coutu, A.; Nicolle, J.

    2016-11-01

    In the operation of hydraulic turbines, no-load and very low load conditions are among the most damaging. Even though there is no power generation, there is still a significant amount of energy which has to be entirely dissipated, mainly in the runner, where the flow is quite complex, with large scale unsteady and chaotic vortices resulting from partial pumping. This paper presents different approaches to perform stress analyses at low load conditions on a Francis turbine, taking into account the pressure fluctuations on the runner blades due to the large stochastic flow structures inherent in no-load operating regimes. With appropriate mesh density and time step, unsteady computational fluid dynamics (CFD) simulations using the SAS-SST turbulence model can be used on a Francis runner to predict the pressure fluctuations with reasonable accuracy when compared to measurements. These calculated pressure loads can then be used to predict the dynamic stresses with finite-element analyses (FEA). Different approaches are discussed ranging from quasi-static single-blade models to full runner time- dependent one-way fluid-structure interaction (FSI). Pros and cons of the different modelling strategies will be discussed in a detailed analysis of the structural results with comparisons to experimental data. Once the time signal of the stochastic stress at no-load conditions is obtained, the runner fatigue damage related to this operating condition can be estimated using different tools such as time signal extrapolation and rainflow counting.

  15. Influence of Reservoir Operation on River Eco-hydrological Regime Variation

    NASA Astrophysics Data System (ADS)

    Chang, J.; Wang, Y.; Li, Y.

    2013-12-01

    With the development of reservoir, river hydrological situation has undergone great changes. Liujiaxia and Longyangxia reservoir which all have great regulation ability were constructed in the upper reaches above Lanzhou station of the Yellow River. In view of the Indicator of Hydrologic Alteration (IHA), the Range of Variability Approach ( RVA ) is used to calculate the eco- hydrological characteristic values and analyze the influence of different reservoir operating modes on the variation of eco-hydrological characteristics of the Yellow River upstream. On the whole, the hydrologic regime at each station downstream of the Liujiaxia reservoir has changed obviously, especially that at Lanzhou station. The overall degree of hydrologic alteration with single reservoir (Liujiaxia) was 72. 64%, and the hydrologic alteration degree with two reservoirs joint operation was 78. 90%. Both of them were belong to high change. Also, after joint operation of Liujiaxia and Longyangxia reservoir, the flow in flood season significantly reduce and the number of high and low flow reversals increase, which would influence the living condition of aquatic organism in the Yellow River, and greatly endanger the aquatic species' reproduction.

  16. Clogging of Joule-Thomson Devices in Liquid Hydrogen-Lunar Lander Descent Stage Operating Regime

    NASA Astrophysics Data System (ADS)

    Jurns, J. M.

    2010-04-01

    Joule-Thomson (J-T) devices have been identified as critical components for future space exploration missions. The NASA Constellation Program lunar architecture considers LOX/LH2 propulsion for the lunar lander descent stage main engine an enabling technology, ensuring the cryogenic propellants are available at the correct conditions for engine operation. This cryogenic storage system may utilize a Thermodynamic Vent System (TVS) that includes J-T devices to maintain tank fluid pressure and temperature. Previous experimental investigations have indicated that J-T devices may become clogged when flowing LH2 while operating at a temperature range from 20.5 K to 24.4 K. It has been proposed that clogging is due to a trace amount of metastable, supercooled liquid neon in the regular LH2 supply. In time, flow blockage occurs from accretion of solid neon on the orifice. This clogging poses a realistic threat to spacecraft propulsion systems utilizing J-T devices in cryogenic pressure control systems. TVS failure due to J-T clogging would prevent removal of environmental heat from the propellant and potential loss of mission. This report describes J-T clogging tests performed with LH2. Tests were performed in the expected Lunar Lander operating regime, and several methods were evaluated to determine the optimum approach to mitigating the potential risk of J-T clogging.

  17. Effect of the river discharge implementation in an operational model for the West Iberia coastal area.

    NASA Astrophysics Data System (ADS)

    Campuzano, Francisco; Brito, David; Juliano, Manuela; Fernandes, Rodrigo; Neves, Ramiro

    2015-04-01

    In the Iberian Peninsula, most of the largest rivers discharge on the Atlantic coast draining almost two thirds of the territory. It is an important source of nutrients and sediments to these coastal areas. Rivers discharges in the Atlantic area when compared with the ones in the Mediterranean side present the particularity that their water before is released into the ocean is previously mixed in their estuaries in a different ratio depending of the estuarine residence time and the discharged flow. In order to evaluate the relative importance of the inland waters in the circulation patterns of Western Iberia, the rivers discharges were implemented in the PCOMS model application (Portuguese Coast Operational Modelling System). To reproduce the water continuum including the different spatial and temporal scales, a methodology consisting in a system of integrated models using the Mohid model was designed. At the watershed level, the Mohid Land model calculated operationally water flow and properties, including nutrients, for the main river catchments of Western Iberian with a 2 km horizontal resolution. Downstream, several operational hydrodynamic and biological estuarine applications used those outcomes as model inputs, filling the gaps in the observation network. From the estuarine models, the tidally modulated water and properties fluxes to the coast were obtained. These fluxes were finally imposed in the Portuguese Coast Operational Modelling System (PCOMS), a fully 3D baroclinic hydrodynamic and ecological regional model that covers the Iberian Atlantic front. The fate of the rivers discharges were analysed by integrating model results in boxes, comparing the climatologies obtained with and without rivers and the rivers area of influence was obtained by lagrangian tracers simulations.

  18. Initial Operation of Microwave Discharge Ion Engines Onboard “HAYABUSA” Asteroid Explorer

    NASA Astrophysics Data System (ADS)

    Kuninaka, Hitoshi; Nishiyama, Kazutaka; Shimizu, Yukio; Toki, Kyoichiro; Kawaguchi, Jun'Ichiro; Uesugi, Kuninori

    The microwave discharge ion engine generates plasmas of the main ion source as well as the neutralizer using 4GHz microwave without discharge electrodes and hollow cathodes, so that long life and durability against oxygen and air are expected. MUSES-C “HAYABUSA” spacecraft installing four microwave discharge ion engines was launched into deep space by M-V rocket on May 9, 2003. After vacuum exposure and several runs of baking for reduction of residual gas the ion engine system established the continuous acceleration of the spacecraft toward an asteroid. The Doppler shift measurement of the communication microwave revealed the performance of ion engines, which is 8mN thrust force for a single unit with 3,200sec specific impulse at 23mN/kW thrust power ratio. At the beginning of December 2003 the accumulated operational time exceeded 7,000 hours and units.

  19. Effects of dam operation on the endangered Júcar nase, Parachondrostoma arrigonis, related to mesohabitats, microhabitat availability and water temperature regime, in the river Cabriel (Spain)

    NASA Astrophysics Data System (ADS)

    Martinez-Capel, Francisco; Costa, Rui; Muñoz-Mas, Rafael; Diego Alcaraz-Hernandez, Juan; Hernandez-Mascarell, Aina

    2010-05-01

    The presence of large dams affects habitat availability, often regarded as the primary factor that limits population and community recovery in rivers. Physical habitat is often targeted in restoration, but there is often a paucity of useful information. Habitat degradation has reduced the complexity and connectivity of the Mediterranean streams in Spain. These changes have diminished the historical range of the endangered Júcar nase, Parachondrostoma arrigonis (Steindachner, 1866), isolated the populations of this species, and probably contributed to its risk of extinction. In the Júcar River basin (Spain), where this fish is endemic, the populations are mainly restricted to the river Cabriel, which is fragmented in two segments by the large dam of Contreras. In this river, 3 main lines of research were developed from 2006 to 2008, i.e., microhabitat suitability, mesohabitat suitability, and water temperature, in order to relate such kind of variables with the flow regime. The main goal of the research project, funded by the Spanish Ministry of Environment, was to detect the main reasons of the species decline, and to propose dam operation improvements to contribute to the recovery of the species. The flow and water temperature regimes were also studied in the river Cabriel, upstream and downstream the large dam of Contreras. During the three years of study, below the dam it was observed a small and not significant variation in the proportions of slow and fast habitats; the regulated flow regime was pointed out as the main reason of such variations. At the microhabitat scale, optimal ranges for average depth and velocity were defined; these data allowed us to develop an estimation of weighted useable area under natural and regulated conditions. The Júcar nase were found majorly at depths no greater than 1,15 meters with slow water velocities. It was possible to observe a clear alteration of the flow and water temperature regime below the dam, due to the cold

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

    NASA Astrophysics Data System (ADS)

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

    2011-02-01

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

  1. 46 CFR 153.1130 - Failure of slops discharge recording equipment; operating with, reporting failures, and replacing...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Failure of slops discharge recording equipment; operating with, reporting failures, and replacing pollution equipment: Category A, B, C, D. 153.1130 Section... slops discharge recording equipment; operating with, reporting failures, and replacing...

  2. 46 CFR 153.1130 - Failure of slops discharge recording equipment; operating with, reporting failures, and replacing...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Failure of slops discharge recording equipment; operating with, reporting failures, and replacing pollution equipment: Category A, B, C, D. 153.1130 Section... slops discharge recording equipment; operating with, reporting failures, and replacing...

  3. 46 CFR 153.1130 - Failure of slops discharge recording equipment; operating with, reporting failures, and replacing...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Failure of slops discharge recording equipment; operating with, reporting failures, and replacing pollution equipment: Category A, B, C, D. 153.1130 Section... slops discharge recording equipment; operating with, reporting failures, and replacing...

  4. 46 CFR 153.1130 - Failure of slops discharge recording equipment; operating with, reporting failures, and replacing...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Failure of slops discharge recording equipment; operating with, reporting failures, and replacing pollution equipment: Category A, B, C, D. 153.1130 Section... slops discharge recording equipment; operating with, reporting failures, and replacing...

  5. 46 CFR 153.1130 - Failure of slops discharge recording equipment; operating with, reporting failures, and replacing...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Failure of slops discharge recording equipment; operating with, reporting failures, and replacing pollution equipment: Category A, B, C, D. 153.1130 Section... slops discharge recording equipment; operating with, reporting failures, and replacing...

  6. Plasma characteristics of argon glow discharge produced by AC power supply operating at low frequencies

    NASA Astrophysics Data System (ADS)

    Kongpiboolkid, Watcharapon; Mongkolnavin, Rattachat

    2015-04-01

    Non-thermal properties of Argon glow discharge operating with various operating pressures were measured and presented in this work. The Argon plasma is produced by a parallel conducting electrodes coupling with a high voltage AC power supply. The power supply can generate high AC voltage at various frequencies. The frequencies for the operation are in the range of a few kHz. The system is capable of generating electric field between the two metal electrodes discharge system. The characteristics of plasma produced were measured by optical emission spectroscopy (OES) technique where electron temperature (Te) and electron number density (ne) can be determined by line intensity ratio method. The value of electron number density was then determined from the Saha-Eggert equation. Our results show that the electron number density of the discharge obtained is of the order of 10-17 - 10-18 m-3 where the electron temperature is between 1.00-2.00 eV for various operating frequencies used which are in good agreement with similar results published earlier.

  7. Plasma characteristics of argon glow discharge produced by AC power supply operating at low frequencies

    SciTech Connect

    Kongpiboolkid, Watcharapon; Mongkolnavin, Rattachat

    2015-04-24

    Non-thermal properties of Argon glow discharge operating with various operating pressures were measured and presented in this work. The Argon plasma is produced by a parallel conducting electrodes coupling with a high voltage AC power supply. The power supply can generate high AC voltage at various frequencies. The frequencies for the operation are in the range of a few kHz. The system is capable of generating electric field between the two metal electrodes discharge system. The characteristics of plasma produced were measured by optical emission spectroscopy (OES) technique where electron temperature (T{sub e}) and electron number density (n{sub e}) can be determined by line intensity ratio method. The value of electron number density was then determined from the Saha-Eggert equation. Our results show that the electron number density of the discharge obtained is of the order of 10{sup −17} − 10{sup −18} m{sup −3} where the electron temperature is between 1.00−2.00 eV for various operating frequencies used which are in good agreement with similar results published earlier.

  8. Progress toward steady-state tokamak operation exploiting the high bootstrap current fraction regime

    NASA Astrophysics Data System (ADS)

    Ren, Q. L.; Garofalo, A. M.; Gong, X. Z.; Holcomb, C. T.; Lao, L. L.; McKee, G. R.; Meneghini, O.; Staebler, G. M.; Grierson, B. A.; Qian, J. P.; Solomon, W. M.; Turnbull, A. D.; Holland, C.; Guo, W. F.; Ding, S. Y.; Pan, C. K.; Xu, G. S.; Wan, B. N.

    2016-06-01

    Recent DIII-D experiments have increased the normalized fusion performance of the high bootstrap current fraction tokamak regime toward reactor-relevant steady state operation. The experiments, conducted by a joint team of researchers from the DIII-D and EAST tokamaks, developed a fully noninductive scenario that could be extended on EAST to a demonstration of long pulse steady-state tokamak operation. Improved understanding of scenario stability has led to the achievement of very high values of βp and βN , despite strong internal transport barriers. Good confinement has been achieved with reduced toroidal rotation. These high βp plasmas challenge the energy transport understanding, especially in the electron energy channel. A new turbulent transport model, named TGLF-SAT1, has been developed which improves the transport prediction. Experiments extending results to long pulse on EAST, based on the physics basis developed at DIII-D, have been conducted. More investigations will be carried out on EAST with more additional auxiliary power to come online in the near term.

  9. High-efficiency FEL-oscillator with Bragg resonator operated in reversed guide field regime

    SciTech Connect

    Kaminsky, A.K.; Sedykh, S.N.; Sergeyev, A.P.

    1995-12-31

    The aim of the present work was to develop a narrow-band FEL-oscillator working in millimeter wavelength with, high efficiency. It looked promising to combine the high selective property of Bragg resonator with high efficiency and other advantages of FEL operation in the reversed guide-field regime. An experimental study of the FEL was performed using lilac LIU-3000 (JINR, Dubna) with the electron energy of 1 MeV, beam current up to 200 A and pulse duration of 200 ns. The beam was injected into the internction region with guide magnetic field of 2.9 kGs. Transverse oscillations of electrons were pumped by the helical wiggler with the period length of 6 cm and the field slowly up-tapering over the initial 6 periods. The FEI electrodynamic system consisted of a circular waveguide with diameter 20 mm and two Bragg reflectors. The H wave of the circular waveguide was shown for operation. Two effective feedback waves were observed in {open_quotes}cold{close_quotes} electrodynamic measurement in correspondence with calculations; the E wave near the frequency of 31. 5 GHz and the E wave - 37.5 GHz. The width of the both reflection resonances was about 2%. In {open_quotes}hot{close_quotes} experiments the radiation on the designed H wave and frequencies corresponding to the both feedback waves was registered separately. Selection of the frequency was realized by varying of the wiggler field strength. The spectrum was measured with a set of the cut--off waveguide filters with inaccuracy less than 2%. Calibrated Semiconductor detectors wire used to measure the radiation power. The radiation with the frequencies of 37.5 and 31.5 GHz was observed in vicinity of the wiggler field amplitude of 2.5 kGs. The measured spectrum width of the output FEL-oscillator radiation did not exceed the width of the Bragg reflector resonances for the both feedback waves.

  10. Powerful electrostatic FEL: Regime of operation, recovery of the spent electron beam and high voltage generator

    SciTech Connect

    Boscolo, I.; Gong, J.

    1995-02-01

    FEL, driven by a Cockcroft-Walton electrostatic accelerator with the recovery of the spent electron beam, is proposed as powerful radiation source for plasma heating. The low gain and high gain regimes are compared in view of the recovery problem and the high gain regime is shown to be much more favourable. A new design of the onion Cockcroft-Walton is presented.

  11. Future changes in Mekong River hydrology: impact of climate change and reservoir operation on discharge

    NASA Astrophysics Data System (ADS)

    Lauri, H.; de Moel, H.; Ward, P. J.; Räsänen, T. A.; Keskinen, M.; Kummu, M.

    2012-12-01

    The transboundary Mekong River is facing two ongoing changes that are expected to significantly impact its hydrology and the characteristics of its exceptional flood pulse. The rapid economic development of the riparian countries has led to massive plans for hydropower construction, and projected climate change is expected to alter the monsoon patterns and increase temperature in the basin. The aim of this study is to assess the cumulative impact of these factors on the hydrology of the Mekong within next 20-30 yr. We downscaled the output of five general circulation models (GCMs) that were found to perform well in the Mekong region. For the simulation of reservoir operation, we used an optimisation approach to estimate the operation of multiple reservoirs, including both existing and planned hydropower reservoirs. For the hydrological assessment, we used a distributed hydrological model, VMod, with a grid resolution of 5 km × 5 km. In terms of climate change's impact on hydrology, we found a high variation in the discharge results depending on which of the GCMs is used as input. The simulated change in discharge at Kratie (Cambodia) between the baseline (1982-1992) and projected time period (2032-2042) ranges from -11% to +15% for the wet season and -10% to +13% for the dry season. Our analysis also shows that the changes in discharge due to planned reservoir operations are clearly larger than those simulated due to climate change: 25-160% higher dry season flows and 5-24% lower flood peaks in Kratie. The projected cumulative impacts follow rather closely the reservoir operation impacts, with an envelope around them induced by the different GCMs. Our results thus indicate that within the coming 20-30 yr, the operation of planned hydropower reservoirs is likely to have a larger impact on the Mekong hydrograph than the impacts of climate change, particularly during the dry season. On the other hand, climate change will increase the uncertainty of the

  12. Biological nutrient removal in a sequencing batch reactor operated as oxic/anoxic/extended-idle regime.

    PubMed

    Li, Xiao-ming; Chen, Hong-bo; Yang, Qi; Wang, Dong-bo; Luo, Kun; Zeng, Guang-ming

    2014-06-01

    Previous researches have demonstrated that biological phosphorus removal from wastewater could be induced by oxic/extended-idle (O/EI) regime. In this study, an anoxic period was introduced after the aeration to realize biological nutrient removal. High nitrite accumulation ratio and polyhydroxyalkanoates biosynthesis were obtained in the aeration and biological nutrient removal could be well achieved in oxic/anoxic/extended-idle (O/A/EI) regime for the wastewater used. In addition, nitrogen and phosphorus removal performance in O/A/EI regime was compared with that in conventional anaerobic/anoxic/aerobic (A(2)/O) and O/EI processes. The results showed that O/A/EI regime exhibited higher nitrogen and phosphorus removal than A(2)/O and O/EI processes. More ammonium oxidizing bacteria and polyphosphate accumulating organisms and less glycogen accumulating organisms containing in the biomass might be the principal reason for the better nitrogen and phosphorus removal in O/A/EI regime. Furthermore, biological nutrient removal with O/A/EI regime was demonstrated with municipal wastewater. The average TN, SOP and COD removal efficiencies were 93%, 95% and 87%, respectively.

  13. Future changes in Mekong River hydrology: impact of climate change and reservoir operation on discharge

    NASA Astrophysics Data System (ADS)

    Lauri, H.; de Moel, H.; Ward, P. J.; Räsänen, T. A.; Keskinen, M.; Kummu, M.

    2012-05-01

    The transboundary Mekong River is facing two on-going changes that are estimated to significantly impact its hydrology and the characteristics of its exceptional flood pulse. The rapid economic development of the riparian countries has led to massive plans for hydropower construction, and the projected climate change is expected to alter the monsoon patterns and increase temperature in the basin. The aim of this study is to assess the cumulative impact of these factors on the hydrology of the Mekong within next 20-30 yr. We downscaled output of five General Circulation Models (GCMs) that were found to perform well in the Mekong region. For the simulation of reservoir operation, we used an optimisation approach to estimate the operation of multiple reservoirs, including both existing and planned hydropower reservoirs. For hydrological assessment, we used a distributed hydrological model, VMod, with a grid resolution of 5 km × 5 km. In terms of climate change's impact to hydrology, we found a high variation in the discharge results depending on which of the GCMs is used as input. The simulated change in discharge at Kratie (Cambodia) between the baseline (1982-1992) and projected time period (2032-2042) ranges from -11% to +15% for the wet season and -10% to +13% for the dry season. Our analysis also shows that the changes in discharge due to planned reservoir operations are clearly larger than those simulated due to climate change: 25-160% higher dry season flows and 5-24% lower flood peaks in Kratie. The projected cumulative impacts follow rather closely the reservoir operation impacts, with an envelope around them induced by the different GCMs. Our results thus indicate that within the coming 20-30 yr, the operation of planned hydropower reservoirs is likely to have a larger impact on the Mekong hydrograph than the impacts of climate change, particularly during the dry season. On the other hand, climate change will increase the uncertainty of the estimated

  14. Hollow cathode operation at high discharge currents. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Friedly, Verlin Joe

    1990-01-01

    It was shown that ion thruster hollow cathode operation at high discharge current levels can induce reduced thruster lifetimes by causing cathode insert overheating and/or erosion of surfaces located downstream of the cathode. The erosion problem has been particularly baffling because the mechanism by which it occurs has not been understood. The experimental investigation described reveals the energies of the ions produced close to the cathode orifice can be several times the anode-to-cathode potential difference generally considered available to accelerate them. These energies (of order 50 eV) are sufficient to cause the observed erosion rates. The effects of discharge current (to 60 A), magnetic field configuration and the cathode flowrate, orifice diameter and insert design on the energies and current densities of these jet ions are examined. A model describing the mechanism by which the high energy ions could be produced when the anode-cathode potential difference is insufficient is proposed. The effects of discharge current on cathode temperature and internal pressure are also examined experimentally and described phenomenologically.

  15. 40 CFR Appendix B to Part 434 - Baseline Determination and Compliance Monitoring for Pre-existing Discharges at Remining Operations

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS COAL MINING POINT... establishing effluent limitations for pre-existing discharges at coal remining operations, in accordance with the requirements set forth in subpart G; Coal Remining. The requirements specify that...

  16. 40 CFR Appendix B to Part 434 - Baseline Determination and Compliance Monitoring for Pre-existing Discharges at Remining Operations

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS COAL MINING POINT... establishing effluent limitations for pre-existing discharges at coal remining operations, in accordance with the requirements set forth in Subpart G; Coal Remining. The requirements specify that...

  17. Potential Industrial Applications of the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) Operating in Ambient Air

    NASA Astrophysics Data System (ADS)

    Reece Roth, J.

    2004-11-01

    The majority of industrial plasma processing with glow discharges has been conducted at pressures below 10 torr. This tends to limit applications to high value workpieces as a result of the high capital cost of vacuum systems and the production constraints of batch processing. It has long been recognized that glow discharge plasmas would play a much larger industrial role if they could be generated at one atmosphere. The One Atmosphere Uniform Glow Discharge Plasma (OAUGDP), developed at the University of Tennessee's Plasma Sciences Laboratory, is a non-thermal RF plasma operating on displacement currents with the time-resolved characteristics of a classical low pressure DC normal glow discharge. As a glow discharge, the OAUGDP operates with maximum electrical efficiency at the Stoletow point, where the energy input per ion-electron pair is a minimum [1, 2]. Several interdisciplinary teams have investigated potential applications of the OAUGDP. These teams included collaborators from the UTK Textiles and Nonwovens Development Center (TANDEC), and the Departments of Electrical and Computer Engineering, Microbiology, and Food Science and Technology, as well as the NASA Langley Research Center. The potential applications of the OAUGDP have all been at one atmosphere and room temperature, using air as the working gas. These applications include sterilizing medical and dental equipment; sterilizable air filters to deal with the "sick building syndrome"; removal of soot from Diesel engine exhaust; subsonic plasma aerodynamic effects, including flow re-attachment to airfoils and boundary layer modification; electrohydrodynamic (EDH) flow control of working gases; increasing the surface energy of materials; improving the adhesion of paints and electroplated layers: improving the wettability and wickability of fabrics; stripping of photoresist; and plasma deposition and directional etching of potential microelectronic relevance. [1] J. R. Roth, Industrial Plasma Engineering

  18. Integrated scheduling of a container handling system with simultaneous loading and discharging operations

    NASA Astrophysics Data System (ADS)

    Li, Chen; Lu, Zhiqiang; Han, Xiaole; Zhang, Yuejun; Wang, Li

    2016-03-01

    The integrated scheduling of container handling systems aims to optimize the coordination and overall utilization of all handling equipment, so as to minimize the makespan of a given set of container tasks. A modified disjunctive graph is proposed and a mixed 0-1 programming model is formulated. A heuristic algorithm is presented, in which the original problem is divided into two subproblems. In the first subproblem, contiguous bay crane operations are applied to obtain a good quay crane schedule. In the second subproblem, proper internal truck and yard crane schedules are generated to match the given quay crane schedule. Furthermore, a genetic algorithm based on the heuristic algorithm is developed to search for better solutions. The computational results show that the proposed algorithm can efficiently find high-quality solutions. They also indicate the effectiveness of simultaneous loading and discharging operations compared with separate ones.

  19. Proton acceleration by single-cycle laser pulses offers a novel monoenergetic and stable operating regime

    NASA Astrophysics Data System (ADS)

    Zhou, M. L.; Yan, X. Q.; Mourou, G.; Wheeler, J. A.; Bin, J. H.; Schreiber, J.; Tajima, T.

    2016-04-01

    Prompted by the possibility to produce high energy, single-cycle laser pulses with tens of Petawatt (PW) power, we have investigated laser-matter interactions in the few optical cycle and ultra relativistic intensity regimes. A particularly interesting instability-free regime for ion production was revealed leading to the efficient coherent generation of short (femtosecond; 10 - 15 s ) monoenergetic ion bunches with a peak energy greater than GeV. Of paramount importance, the interaction is absent of the Rayleigh Taylor Instabilities and hole boring that plague techniques such as target normal sheath acceleration and radiation pressure acceleration.

  20. Magnification of subwavelength field distributions at microwave frequencies using a wire medium slab operating in the canalization regime

    NASA Astrophysics Data System (ADS)

    Ikonen, Pekka; Simovski, Constantin; Tretyakov, Sergei; Belov, Pavel; Hao, Yang

    2007-09-01

    Authors demonstrate numerically the magnification of subwavelength field pattern using a wire medium slab operating in the canalization regime. The magnifying slab is implemented by radially enlarging the distance between adjacent wires, and the operational frequency is tuned to coincide with the Fabry-Pérot resonance condition. The near-field pattern of a complex-shaped source is canalized over an electrical distance corresponding roughly to three wavelengths (3λ), and the pattern details are magnified by a factor of 3. The performance is also studied at several frequencies deviating from the one of the Fabry-Pérot resonance.

  1. Numerical design of a Knudsen pump with curved channels operating in the slip flow regime

    NASA Astrophysics Data System (ADS)

    Leontidis, Vlasios; Chen, Jie; Baldas, Lucien; Colin, Stéphane

    2014-08-01

    A numerical procedure has been developed for modeling 2D thermal creep flows with Fluent®. Complete first order velocity slip, including thermal creep and walls curvature effects, as well as temperature jump, boundary conditions, are implemented via C routines. After validation on benchmark flows, the technique is used for designing a Knudsen pump with curved microchannels and it is demonstrated that this micropump can be efficient in the slip flow regime.

  2. Optimization of wire Electrical Discharge turning operations using robust design of experiment

    NASA Astrophysics Data System (ADS)

    Mohammadi, Aminollah; Fadaei Tehrani, Alireza; Safari, Mahdi

    2011-01-01

    In the present study a multi response optimization method using Taguchi's robust design approach is proposed for wire electrical discharge turning (WEDT) operations. Experimentation was planned as per Taguchi's L18 orthogonal array. Each experiment has been performed under different machining conditions of power, servo, voltage, pulse off time, wire tension, wire feed speed, and rotational speed. Three responses namely material removal rate (MRR), surface roughness, and roundness have been considered for each experiment. The machining parameters are optimized with the multi response characteristics of the material removal rate, surface roughness, and roundness. Multi response S/N (MRSN) ratio is applied to measure the performance characteristics deviating from the actual value. Analysis of variance (ANOVA) is employed to identify the level of importance of the machining parameters on the multiple performance considered characteristics. Finally experimental confirmation was carried out to identify the effectiveness of this proposed method.

  3. Injection Locking of Quantum-Dot Microlasers Operating in the Few-Photon Regime

    NASA Astrophysics Data System (ADS)

    Schlottmann, Elisabeth; Holzinger, Steffen; Lingnau, Benjamin; Lüdge, Kathy; Schneider, Christian; Kamp, Martin; Höfling, Sven; Wolters, Janik; Reitzenstein, Stephan

    2016-10-01

    We experimentally and theoretically investigate injection locking of quantum-dot microlasers in the regime of cavity quantum electrodynamics. We observe frequency locking and phase locking where cavity-enhanced spontaneous emission enables simultaneous stable oscillation at the master frequency and at the solitary frequency of the slave microlaser. Measurements of the second-order autocorrelation function prove this simultaneous presence of both master and slavelike emission, where the former has coherent character with g(2 )(0 )=1 , while the latter has thermal character with g(2 )(0 )=2 . Semiclassical rate equations explain this peculiar behavior by cavity-enhanced spontaneous emission and a low number of photons in the laser mode.

  4. Operation features of a longitudinal-capacitive-discharge-pumped CuBr laser

    SciTech Connect

    Gubarev, F A; Shiyanov, D V; Evtushenko, Gennadii S; Sukhanov, V B

    2010-01-31

    The frequency and energy characteristics of a capacitive-discharge-pumped CuBr laser are investigated. Processes proceeding in the discharge circuit of lasers pumped in this way, in particular, pumped without an external storage capacitor are analysed. It is shown that, depending on the pumping circuit, laser levels are excited either during the charge current flow or during the discharge of electrode capacitances. The differences in the influence of the active HBr addition on the characteristics of the discharge and lasing compared to the case of a usual repetitively pulsed high-current discharge with internal electrodes are established. (lasers)

  5. Soft X-Ray Emission Analysis Of A Pulsed Capillary Discharge Operated In Nitrogen

    NASA Astrophysics Data System (ADS)

    Valdivia, M. P.; Valenzuela, J. C.; Wyndham, E. S.; Favre, M.; Chuaqui, H.; Bhuyan, H.

    2014-05-01

    We present results from a pulsed capillary ns discharge source, operated in Nitrogen and N/He mixtures, in an alumina capillary 2.1mm long with outer diameter of 6.3mm and inner diameter of 1.6mm. The electrical energy stored is 0.5J with peak current of 6kA. Fast charging from an IGBT based pulsed power circuit allows operation at 35-600 Hz with voltages in the range of 18-24kV. Characteristic time-integrated N/He spectra were recorded and analyzed for values of 20-200 Å, with clear evidence of He-like Nitrogen emission at 28.8Å, which represents a possible source for water window soft x-ray microscopy. Filtered diode measurements reveal the influence of axial electron beams, generated by hollow cathode dynamics, on the x-ray emission in the range of 300-450 eV. We discuss optimal voltage applied and pressure conditions for soft x-ray generation. Time-integrated MCP images of a filtered slit-wire system delivered clear evidence of full wall detachment with ~500μm in radial size for the entire emission range and ~200μm for the emission in the 300-450 eV range.

  6. Special features of deformation and disruption of nickel alloys under conditions simulating operating regimes

    NASA Astrophysics Data System (ADS)

    Kleshchev, A. S.; Vlasova, O. N.; Lyakhova, L. V.

    1995-11-01

    Turbine, compressor, and rotor disks are critical elements of an aircraft engine. The repeated heating and cooling to which the disks are subjected during operation cause an accumulation of plastic deformation and development of fatigue rupture. Therefore, it is important to know in what way the nickel alloys lose strength and fail in the process of long-term operation at high temperatures. The aim of the present work is to investigate the effect of various structural parameters on the processes of deformation and rupture of high-temperature nickel alloys used for disks of gas-turbine engines under conditions close to the operating ones.

  7. Determination of axial forces in centrifugal blowers in regulating their operating regime

    SciTech Connect

    Dovzhenko, V.N.; Bondarenko, G.A.; Eremenko, E.N.

    1986-03-01

    The authors examine the effect, on the axial force, of the most frequently used regulation methods in centrifugal blowers: throttling at suction and supercharging, variation of the angular velocity of the rotor, and the variation of the twist of the flow using the input regulating device (IRD). The investigations were conducted on a model of a single-stage centrifugal blower of natural gas equipped with a strain gauging system for measuring the axial load in the thrust bearing. An IRD of the axial type with the central body was used in regulation by varying the twist of the flow at the inlet into the rotor. A computer was used for averaging out the experimental data and integrating in respect to the surfaces of the rotor. Formation, by means of the IRD, of positive twisting of the flow in front of the rotor results in a considerably smaller reduction of axial force, especia-ly in regimes. Throttling in both supercharging and in suction increased the axial force.

  8. A Programmable Difference-of-Gaussian Analog Complementary Metal Oxide Semiconductor Image Sensor Operating in the Subthreshold Regime

    NASA Astrophysics Data System (ADS)

    Wang, Zheye; Shibata, Tadashi

    2013-04-01

    A difference-of-Gaussian (DoG) analog CMOS image sensor architecture in which the kernel size and shape are made arbitrarily programmable has been developed based on the MOS subthreshold characteristics. The variability of MOS transistor threshold voltage causes a serious problem in the circuits operating in the subthreshold regime because the current varies exponentially depending on the threshold voltage. The problem has been alleviated by introducing a cancellation scheme employing a switched floating-gate MOS (neuMOS) circuitry. A proof-of-concept chip was designed in a 0.18-µm CMOS technology. The operation of the designed circuits was investigated by SPICE (simulation program with integrated circuit emphasis) simulation and their basic functions were demonstrated. A part of the core function, i.e., the generation of the Gaussian function profile, was confirmed by the measurement of a fabricated test circuit.

  9. Observation of a high performance operating regime with small edge-localized modes in the National Spherical Torus Experiment

    NASA Astrophysics Data System (ADS)

    Maingi, R.; Tritz, K.; Fredrickson, E. D.; Menard, J. E.; Sabbagh, S. A.; Stutman, D.; Bell, M. G.; Bell, R. E.; Bush, C. E.; Gates, D. A.; Johnson, D. W.; Kaita, R.; Kaye, S. M.; Kugel, H. W.; LeBlanc, B. P.; Mueller, D.; Raman, R.; Roquemore, A. L.; Soukhanovskii, V. A.

    2005-04-01

    We report the observation of a high performance scenario in the National Spherical Torus Experiment with very small edge-localized modes (ELMs). These ELMs, individually, have no measurable impact on the stored energy and are observed by several diagnostics. The small ELMs have clear differences as compared with the ELM types reported in the literature, and this operating mode has distinct features compared with other high performance tokamak scenarios with little or no ELMs. The ELM is termed as 'type V', and it has a short-lived n = 1 magnetic precursor oscillation rotating counter to the plasma current and a distinct signature on the soft x-ray system. If we could extrapolate it, this scenario would provide an attractive operating regime for next step fusion experiments.

  10. 33 CFR 151.66 - Operating requirements: Discharge of garbage in the Great Lakes and other navigable waters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Implementation of... Pollution from Ships Garbage Pollution and Sewage § 151.66 Operating requirements: Discharge of garbage...

  11. 33 CFR 151.66 - Operating requirements: Discharge of garbage in the Great Lakes and other navigable waters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Implementation of... Pollution from Ships Garbage Pollution and Sewage § 151.66 Operating requirements: Discharge of garbage...

  12. 33 CFR 151.66 - Operating requirements: Discharge of garbage in the Great Lakes and other navigable waters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Implementation of... Pollution from Ships Garbage Pollution and Sewage § 151.66 Operating requirements: Discharge of garbage...

  13. 33 CFR 151.66 - Operating requirements: Discharge of garbage in the Great Lakes and other navigable waters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Implementation of... Pollution from Ships Garbage Pollution and Sewage § 151.66 Operating requirements: Discharge of garbage...

  14. 33 CFR 151.66 - Operating requirements: Discharge of garbage in the Great Lakes and other navigable waters of the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER... Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.66 Operating requirements: Discharge...

  15. 40 CFR Appendix B to Part 434 - Baseline Determination and Compliance Monitoring for Pre-existing Discharges at Remining Operations

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Monitoring for Pre-existing Discharges at Remining Operations B Appendix B to Part 434 Protection of.... B Appendix B to Part 434—Baseline Determination and Compliance Monitoring for Pre-existing... monthly (single-observation) procedure and an annual procedure shall be applied, as described below. b....

  16. High energy bursts from a solid state laser operated in the heat capacity limited regime

    SciTech Connect

    Albrecht, G.; George, E.V.; Krupke, W.

    1994-12-31

    Solid state laser technology is a very well developed field and numerous embodiments and modes of operation have been demonstrated. A more recent development has been the pumping of a solid state laser active medium with an array of diode lasers (diode pumping, for short). These diode pump packages have previously been developed to pump solid state lasers with good efficiency, but low average power. This invention is a method and the resulting apparatus for operating a solid state laser in the heat capacity mode. Instead of cooling the laser, the active medium will heat up until it reaches some maximum acceptable temperature. The waste heat is stored in the active medium itself.

  17. Towards multi-sensor operational monitoring of the European fire regime

    NASA Astrophysics Data System (ADS)

    Beck, P. S. A.; San Miguel-Ayanz, J.; Busetto, L.; Boca, R.; Boccacci, F.

    2014-12-01

    Europe loses approximately half a million hectares of forest to human-caused fires annually. High population densities and fuel loads in areas of forest recovery aid uncontrolled wildfires, despite decreasing use of fire in agriculture. In rural areas such as the Mediterranean, pervasive wildfires can be indicative of socio-economic decline and themselves cause political tension. Since the 2000s, the European Forest Fires Information System maps forest fires in Europe daily, as part of a modular system that also assesses fire risk. This system, developed and maintained by the European Commission, feeds pan-European information to forest fire and civil protection agencies in the EU and provides a consistent quality-checked forest fire record for scientific analysis and global reporting initiatives. The current fire mapping algorithm captures fires larger than 50 ha, owing to its reliance on MODIS imagery. As a result, the system misses about 95% of Europe's forest fires, which contribute 20-25% of the annually burned area, because they are too small for detection. We present a new approach to fire mapping that relies on multiple satellite sensors to improve spatiotemporal detail of mapped fire activity. We implemented the approach to map European wildfires exploiting the 30 m spatial resolution of the Landsat 8 sensor, and the daily overpass of the MODIS sensors. By doing so, detections of smaller fires improved dramatically, although they were somewhat delayed. The algorithm relies on a set of heuristic rules that translate knowledge of the temporal dynamics of fire disturbance, recovery, and confounding factors such as agricultural harvest, into spectro-temporal criteria. By design, it can be adapted to areas with different fire regimes, and ingest information from additional satellite sensors to further improve detection rates and times. We discuss the latter in the context of the Sentinel missions, and their potential contribution to global wildfire monitoring.

  18. Multi-GeV electron beams from capillary discharge guided sub-petawatt class laser pulses in the self-trapping regime

    NASA Astrophysics Data System (ADS)

    Leemans, Wim

    2014-10-01

    Laser plasma accelerators (LPAs) can produce acceleration gradients on the order of tens to hundreds of GV/m, making them attractive as compact particle accelerators. During the past decade, quasi-monochromatic electron beams at the 1 GeV energy level have been produced using laser pulses at the 40-50 TW peak power level. With the availability of petawatt class lasers, beams up to 2 GeV have been produced from 7 cm long gas cells at UT Austin using 150 J laser pulses and at the 1 GeV level with tails extending to 3 GeV at the GIST facility in Korea. In this talk we present experimental results using the 1 Hz petawatt class BELLA laser at LBNL of the generation of multi-GeV electron beams with center energy up to 4.2 GeV, 6% rms energy spread, charge approximately 10 pC and an rms divergence around 0.3 mrad. The beams were produced from 9 cm long capillary discharge waveguide structure with a plasma density of ~ 7 ×1017cm-3 , powered by laser pulses with peak power up to 0.3 PW. Preformed plasma waveguides allow the use of lower laser power compared to unguided plasma structures to achieve the same beam energy. Detailed comparison between experiment and simulation indicates the importance of the near-field laser transverse mode quality on guiding and acceleration in the LPA. By tuning the plasma density, regimes were found where laser beams with a top hat near-field profile were guided well, and where high energy electron beams can be produced, with narrow divergence [ <0.8 mrad (FWHM)], and relatively small integrated energy spread (<10%). Provided that the slice energy spread and emittance are sufficiently low, electron beams with this energy could power x-ray free electron lasers. Future experiments will aim at increasing the beam energy to the 10 GeV level. Work supported by Office of Science, Office of HEP, US DOE Contract DE-AC02-05CH11231.

  19. Operation of a full-scale pumped flow biofilm reactor (PFBR) under two aeration regimes.

    PubMed

    O'Reilly, E; Rodgers, M; Clifford, E

    2011-01-01

    A novel technology suitable for centralised and decentralised wastewater treatment has been developed, extensively tested at laboratory-scale, and trialled at a number of sites for populations ranging from 15 to 400 population equivalents (PE). The two-reactor-tank pumped flow biofilm reactor (PFBR) is characterised by: (i) its simple construction; (ii) its ease of operation and maintenance; (iii) low operating costs; (iv) low sludge production; and (v) comprising no moving parts or compressors, other than hydraulic pumps. By operating the system in a sequencing batch biofilm reactor (SBBR) mode, the following treatment can be achieved: 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and total suspended solids (TSS) reduction; nitrification and denitrification. During a 100-day full-scale plant study treating municipal wastewater and operating at 165 PE and 200 PE (Experiments 1 and 2, respectively), maximum average removals of 94% BOD5, 86% TSS and 80% ammonium-nitrogen (NH4-N) were achieved. During the latter part of Experiment 2, effluent concentrations averaged: 14 mg BOD5/l; 32 mg COD(filtered)/l; 14 mg TSS/l; 4.4 mg NH4-N/l; and 4.0 mg NO3-N/l (nitrate-nitrogen). The average energy consumption was 0.46-0.63 kWh/m3(treated) or 1.25-1.76 kWh/kg BOD5 removed. No maintenance was required during these experiments. The PFBR technology offers a low energy, minimal maintenance technology for the treatment of municipal wastewater.

  20. The 1966 enactment of Medicare: its effect on discharges from Los Angeles County-operated hospitals.

    PubMed Central

    Glassman, P A; Bell, R M; Tranquada, R E

    1994-01-01

    The effect of Medicare on two public hospitals in Los Angeles County was analyzed by examining the percentage of patients 65 years of age and older among all discharges from 1958 through 1971. At Harbor General Hospital, discharges of elderly patients had dropped from 21.7% to 7.9% by late 1966; at Los Angeles County General Hospital, discharges decreased from 15.3% to 10.7% between 1966 and 1967. Monitoring public hospitals' demographic changes after enacting a national health plan may provide information on patients' and providers' acceptance of insurance and on resources needed by public hospitals to care for those left without coverage. PMID:8059897

  1. The 1966 enactment of Medicare: its effect on discharges from Los Angeles County-operated hospitals.

    PubMed

    Glassman, P A; Bell, R M; Tranquada, R E

    1994-08-01

    The effect of Medicare on two public hospitals in Los Angeles County was analyzed by examining the percentage of patients 65 years of age and older among all discharges from 1958 through 1971. At Harbor General Hospital, discharges of elderly patients had dropped from 21.7% to 7.9% by late 1966; at Los Angeles County General Hospital, discharges decreased from 15.3% to 10.7% between 1966 and 1967. Monitoring public hospitals' demographic changes after enacting a national health plan may provide information on patients' and providers' acceptance of insurance and on resources needed by public hospitals to care for those left without coverage.

  2. Restoring a flow regime through the coordinated operation of a multireservoir system: The case of the Zambezi River basin

    NASA Astrophysics Data System (ADS)

    Tilmant, A.; Beevers, L.; Muyunda, B.

    2010-07-01

    Large storage facilities in hydropower-dominated river basins have traditionally been designed and managed to maximize revenues from energy generation. In an attempt to mitigate the externalities downstream due to a reduction in flow fluctuation, minimum flow requirements have been imposed to reservoir operators. However, it is now recognized that a varying flow regime including flow pulses provides the best conditions for many aquatic ecosystems. This paper presents a methodology to derive a trade-off relationship between hydropower generation and ecological preservation in a system with multiple reservoirs and stochastic inflows. Instead of imposing minimum flow requirements, the method brings more flexibility to the allocation process by building upon environmental valuation studies to derive simple demand curves for environmental goods and services, which are then used in a reservoir optimization model together with the demand for energy. The objective here is not to put precise monetary values on environmental flows but to see the marginal changes in release policies should those values be considered. After selecting appropriate risk indicators for hydropower generation and ecological preservation, the trade-off curve provides a concise way of exploring the extent to which one of the objectives must be sacrificed in order to achieve more of the other. The methodology is illustrated with the Zambezi River basin where large man-made reservoirs have disrupted the hydrological regime.

  3. Wind tunnel results of advanced high speed propellers in the takeoff, climb and landing operating regimes

    NASA Technical Reports Server (NTRS)

    Stefko, G. L.; Jeracki, R. J.

    1985-01-01

    Low speed wind tunnel performance tests of two advanced propellers were completed. The 62.2 cm diameter adjustable pitch models were tested at Mach numbers typical of takeoff, initial climbout, and landing speeds in the 10 by 10 ft Supersonic Wind Tunnel. Both models had eight blades and a cruise design point operating condition of 0.80 Mach number, 10.668 km S.A. altitude, 243.8 m/s tip speed and a high power loading of 301 kW sq m. No adverse or unusual low speed operating conditions were found during the test with either the straight blade SR-2 or the 45 deg swept SR-3 propellers. The 45 deg swept propeller efficiency exceeded the straight blade efficiency by 4 to 5%. Typical net efficiencies of the straight and 45 deg swept propeller at a Mach 0.20 takeoff condition were 50.2 and 54.9% respectively. At a Mach 0.34 climb condition, the efficiencies were 53.7 and 59.1%. Reverse thrust data indicates that these propellers are capable of producing more reverse thrust at Mach 0.20 than a high bypass turbofan engine at Mach 0.20.

  4. Wind tunnel results of advanced high speed propellers in the takeoff, climb, and landing operating regimes

    NASA Technical Reports Server (NTRS)

    Stefko, G. L.; Jeracki, R. J.

    1985-01-01

    Low speed wind tunnel performance tests of two advanced propellers were completed. The 62.2 cm diameter adjustable pitch models were tested at Mach numbers typical of takeoff, initial climbout, and landing speeds in the 10 by 10 ft Supersonic Wind Tunnel. Both models had eight blades and a cruise design point operating condition of 0.80 Mach number, 10.668 km S.A. altitude, 243.8 m/s tip speed and a high power loading of 301 kW sq m. No adverse or unusual low speed operating conditions were found during the test with either the straight blade SR-2 or the 45 deg swept SR-3 propellers. The 45 deg swept propeller efficiency exceeded the straight blade efficiency by 4 to 5 percent. Typical net efficiencies of the straight and 45 deg swept propeller at a Mach 0.20 takeoff condition were 50.2 and 54.9 percent respectively. At a Mach 0.34 climb condition, the efficiencies were 53.7 and 59.1 percent. Reverse thrust data indicates that these propellers are capable of producing more reverse thrust at Mach 0.20 than a high bypass turbofan engine at Mach 0.20.

  5. 75 FR 10477 - Draft Report to Congress: Study of Discharges Incidental to Normal Operation of Commercial...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-08

    ...-299 on the types of wastewater discharged from commercial fishing vessels and non- recreational... Permits Division, Office of Wastewater Management (4203M), Environmental Protection Agency, 1200... Robin Danesi, Water Permits Division, Office of Wastewater Management (4203M), Environmental...

  6. Transition from column to micropinch regime in Z-pinches

    SciTech Connect

    Engel, A.; Lebert, R.; Koshelev, K. N.; Sidelnikov, Yu. V.; Gavrilescu, C.; Neff, W.

    1997-05-05

    Plasma focus and Z-pinches are known to be intensive sources of K-ion radiation. This radiation is observed in two different regimes of compression: column and micropinch. Appearance of these regimes depends on combination of discharge circuit parameter and element composition of plasma. Column regime is typical for low current discharges operating in low Z gases. Micropinch regime, which represents a development of ''neck'' type instabilities in a presence of strong radiation losses, is typical for heavy ion plasma, i.e. vacuum spark or plasma focus with admixture of heavy gases. Transition from column to micropinch mode has been investigated experimentally. It was found that appearance of either regime can be quantitatively described by a distinction parameter depending on pinch current, particle density and used element.

  7. Thermodynamic analysis of journal bearings operating under steady state loading in laminar regime. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Khonsari, M. M.

    1983-01-01

    Thermohydrodynamic effects in journal bearings operating under steady load in laminar regime are investigated. An analytical model for the finite and infinitely long journal bearings is formulated. The model includes correction factors for the cavitation effects in the unloaded region of the bearing and the mixing of the recirculating oil and supply oil at the oil inlet. A finite difference computer program is developed to numerically solve the governing equations of the continuity, Reynolds, energy, Laplace heat conduction, and a viscosity-temperature relation simultaneously. The program includes a numerical technique for obtaining an isothermal shaft temperature. The numerical results of temperature distribution and the heat effects on the bearing load carrying capacity agree closely with those of experimental findings. Several different sets of simpler boundary conditions for the energy equation are studied.

  8. Femtosecond Laser Tagging Characterization of a Sweeping Jet Actuator Operating in the Compressible Regime

    NASA Technical Reports Server (NTRS)

    Peters, Christopher J.; Miles, Richard B.; Burns, Ross A.; Bathel, Brett F.; Jones, Gregory S.; Danehy, Paul M.

    2016-01-01

    A sweeping jet (SWJ) actuator operating over a range of nozzle pressure ratios (NPRs) was characterized with femtosecond laser electronic excitation tagging (FLEET), single hot-wire anemometry (HWA) and high-speed/phase-averaged schlieren. FLEET velocimetry was successfully demonstrated in a highly unsteady, oscillatory flow containing subsonic through supersonic velocities. Qualitative comparisons between FLEET and HWA (which measured mass flux since the flow was compressible) showed relatively good agreement in the external flow profiles. The spreading rate was found to vary from 0.5 to 1.2 depending on the pressure ratio. The precision of FLEET velocity measurements in the external flow field was poorer (is approximately equal to 25 m/s) than reported in a previous study due to the use of relatively low laser fluences, impacting the velocity fluctuation measurements. FLEET enabled velocity measurements inside the device and showed that choking likely occurred for NPR = 2.0, and no internal shockwaves were present. Qualitative oxygen concentration measurements using FLEET were explored in an effort to gauge the jet's mixing with the ambient. The jet was shown to mix well within roughly four throat diameters and mix fully within roughly eight throat diameters. Schlieren provided visualization of the internal and external flow fields and showed that the qualitative structure of the internal flow does not vary with pressure ratio and the sweeping mechanism observed for incompressible NPRs also probably holds for compressible NPRs.

  9. Large-signal characterization of DDR silicon IMPATTs operating in millimeter-wave and terahertz regime

    NASA Astrophysics Data System (ADS)

    Acharyya, Aritra; Chakraborty, Jit; Das, Kausik; Datta, Subir; De, Pritam; Banerjee, Suranjana; Banerjee, J. P.

    2013-10-01

    The authors have carried out the large-signal characterization of silicon-based double-drift region (DDR) impact avalanche transit time (IMPATT) devices designed to operate up to 0.5 THz using a large-signal simulation method developed by the authors based on non-sinusoidal voltage excitation. The effect of band-to-band tunneling as well as parasitic series resistance on the large-signal properties of DDR Si IMPATTs have also been studied at different mm-wave and THz frequencies. Large-signal simulation results show that DDR Si IMPATT is capable of delivering peak RF power of 633.69 mW with 7.95% conversion efficiency at 94 GHz for 50% voltage modulation, whereas peak RF power output and efficiency fall to 81.08 mW and 2.01% respectively at 0.5 THz for same voltage modulation. The simulation results are compared with the experimental results and are found to be in close agreement.

  10. Operating Regime for a Backward Raman Laser Amplifier in Preformed Plasma

    SciTech Connect

    Daniel S. Clark; Nathaniel J. Fisch

    2003-02-06

    A critical issue in the generation of ultra-intense, ultra-short laser pulses by backward Raman scattering in plasma is the stability of the pumping pulse to premature backscatter from thermal fluctuations in the preformed plasma. Malkin et al. [V.M. Malkin, et al., Phys. Rev. Lett. 84 (6):1208-1211, 2000] demonstrated that density gradients may be used to detune the Raman resonance in such a way that backscatter of the pump from thermal noise can be stabilized while useful Raman amplification persists. Here plasma conditions for which the pump is stable to thermal Raman backscatter in a homogeneous plasma and the density gradients necessary to stabilize the pump for other plasma conditions are quantified. Other ancillary constraints on a Raman amplifier are also considered to determine a specific region in the Te-he plane where Raman amplification is feasible. By determining an operability region, the degree of uncertainty in density or temperature tolerable for an experimental Raman amplifier is thus also identified. The fluid code F3D, which includes the effects of thermal fluctuations, is used to verify these analytic estimates.

  11. Advances in X-Band TW Accelerator Structures Operating in the 100 MV/M Regime

    SciTech Connect

    Higo, Toshiyasu; Higashi, Yasuo; Matsumoto, Shuji; Yokoyama, Kazue; Adolphsen, Chris; Dolgashev, Valery; Jensen, Aaron; Laurent, Lisa; Tantawi, Sami; Wang, Faya; Wang, Juwen; Dobert, Steffen; Grudiev, Alexej; Riddone, Germana; Wuensch, Walter; Zennaro, Riccardo; /CERN

    2012-07-05

    A CERN-SLAC-KEK collaboration on high gradient X-band accelerator structure development for CLIC has been ongoing for three years. The major outcome has been the demonstration of stable 100 MV/m gradient operation of a number of CLIC prototype structures. These structures were fabricated using the technology developed from 1994 to 2004 for the GLC/NLC linear collider initiative. One of the goals has been to refine the essential parameters and fabrication procedures needed to realize such a high gradient routinely. Another goal has been to develop structures with stronger dipole mode damping than those for GLC/NLC. The latter requires that the surface temperature rise during the pulse be higher, which may increase the breakdown rate. One structure with heavy damping has been RF processed and another is nearly finished. The breakdown rates of these structures were found to be higher by two orders of magnitude compared to those with equivalent acceleration mode parameters but without the damping features. This paper presents these results together with some of the earlier results from non-damped structures.

  12. Global stability and operational regimes of ignitor, ITER, and alcator C-mod

    SciTech Connect

    Detragiache, P.; Bombarda, F.; Coppi, B.; Migliuolo, S.

    1996-12-31

    One of the primary requirements for an experiment capable of approaching ignition conditions is the macroscopic stability of the plasma column. For two proposed ignition experiments (Ignitor and ITER) we analyze numerically (using both the PEST and DCON codes, involving the ideal MHD linearized approximation) the stability of their confinement configuration for different plasma pressure and current profiles. Since in both cases the aspect ratio is tight (2.8 and 2.9, respectively), when the unwinding parameter q({Psi}) < 1 for r {approx_lt} a/2, n = 1 modes, for which the m = 1 and m = 2 poloidal harmonics prevail, involve a major part of the plasma column (q({Psi}) = 2 for r{sub 2} {approx} 3a/4). For profiles that are nearly flat up to the q(r{sub 1}) = 1 surface and are represented by p = p{sub 0}(1 - {Psi}{sup 3}){sup 3/2}, where {Psi} is the (normalized) poloidal flux variable, pressure driven modes, dominated by the m = 2 harmonic, may be found, depending on the value of {beta}{sub p} = 2 {mu}{sub 0}(p)/B{sub p}{sup 2}. These modes are unstable for the reference parameters of operation of ITER (B{sub T}{congruent} 5.7 {Tau}, n{sub 0} {congruent} 1.5 x 10{sup 20} m{sup -3}, {Tau}{sub 0} {congruent} 20 keV), but are stable in the case of Ignitor B{sub T}{congruent}13 {Tau}, n{sub 0} {congruent} 12 keV.

  13. Design and operation of an inverse free-electron-laser accelerator in the microwave regime

    NASA Astrophysics Data System (ADS)

    Yoder, Rodney Bruce

    2000-09-01

    A novel electron accelerator demonstrating the inverse free-electron-laser (IFEL) principle has been designed, built, and operated using radio-frequency power at 2.856 GHz. Such an accelerator uses a stationary, periodic magnetic field to impart transverse motion to charged particles, which are then accelerated by guided electromagnetic waves. The experiment described here demonstrates for the first time the phase dependence of IFEL acceleration. This design uses up to 15 MW of RF power propagating in a smooth-walled circular waveguide surrounded by a pulsed bifilar helical undulator; an array of solenoids provides an axial guiding magnetic field undulator; pitch, which is initially 11.75 cm, is linearly increased to 12.3 cm. over the 1-meter length of the structure to maintain acceleration gradient. Numerical computations predict an energy gain of up to 0.7 MeV using a 6 MeV injected beam from a 2-1/2 cell RF gun, with small energy spread and strong phase trapping. The initial injection phase is the most important parameter, determining the rate of energy gain or loss. These simulations are compared with experimental measurements at low power in which electron beams at energies between 5 and 6 MeV gain up to 0.35 MeV with minimal energy spread, all exiting particles having been accelerated. The predicted phase sensitivity of the mechanism is verified, with beams injected into accelerating phases gaining energy cleanly while those injected into ``decelerating'' phases are shown to be degraded in quality and hardly changed in energy, demonstrating the asymmetry of a tapered-wiggler design. Agreement with simulation is very good for accelerating phases, though less exact otherwise. Scaling to higher power and frequency is investigated. The maximum attainable acceleration gradient for a MIFELA using 150 MW of RF power at 34 GHz is estimated to be at least 30 MV/m, and laser IFELs could conceivably reach gradients in the GeV/m range.

  14. 33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... certified to carry more than 10 persons must not discharge untreated sewage into the sea within 12 nautical miles of Antarctic land or ice shelves; beyond such distance, sewage stored in a holding tank must not... those on board or saving life at sea. Notice of an activity, otherwise prohibited under paragraph (a)...

  15. 33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... certified to carry more than 10 persons must not discharge untreated sewage into the sea within 12 nautical miles of Antarctic land or ice shelves; beyond such distance, sewage stored in a holding tank must not... those on board or saving life at sea. Notice of an activity, otherwise prohibited under paragraph (a)...

  16. 33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... certified to carry more than 10 persons must not discharge untreated sewage into the sea within 12 nautical miles of Antarctic land or ice shelves; beyond such distance, sewage stored in a holding tank must not... those on board or saving life at sea. Notice of an activity, otherwise prohibited under paragraph (a)...

  17. 33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... certified to carry more than 10 persons must not discharge untreated sewage into the sea within 12 nautical miles of Antarctic land or ice shelves; beyond such distance, sewage stored in a holding tank must not... those on board or saving life at sea. Notice of an activity, otherwise prohibited under paragraph (a)...

  18. 33 CFR 151.79 - Operating requirements: Discharge of sewage within Antarctica.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... certified to carry more than 10 persons must not discharge untreated sewage into the sea within 12 nautical miles of Antarctic land or ice shelves; beyond such distance, sewage stored in a holding tank must not... those on board or saving life at sea. Notice of an activity, otherwise prohibited under paragraph (a)...

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

    SciTech Connect

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

    2016-02-15

    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 (H{sub 2}), the ion beam contained three species: H{sup +}, H{sub 2}{sup +}, and H{sub 3}{sup +}. For all experimental conditions, the fraction of H{sub 2}{sup +} 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{sup +} and H{sub 3}{sup +} 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{sup +} fraction in ion beam. The maximum fraction of H{sup +} 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 H{sub 3}{sup +} fraction in the beam. At optimum parameters, the fraction of H{sub 3}{sup +} ions reached 60% of the total ion beam current.

  20. Study of a contracted glow in low-frequency plasma-jet discharges operating with argon

    SciTech Connect

    Minotti, F.; Giuliani, L.; Xaubet, M.; Grondona, D.

    2015-11-15

    In this work, we present an experimental and theoretical study of a low frequency, atmospheric plasma-jet discharge in argon. The discharge has the characteristics of a contracted glow with a current channel of submillimeter diameter and a relatively high voltage cathode layer. In order to interpret the measurements, we consider the separate modeling of each region of the discharge: main channel and cathode layer, which must then be properly matched together. The main current channel was modeled, extending a previous work, as similar to an arc in which joule heating is balanced by lateral heat conduction, without thermal equilibrium between electrons and heavy species. The cathode layer model, on the other hand, includes the emission of secondary electrons by ion impact and by additional mechanisms, of which we considered emission due to collision of atoms excited at metastable levels, and field-enhanced thermionic emission (Schottky effect). The comparison of model and experiment indicates that the discharge can be effectively sustained in its contracted form by the secondary electrons emitted by collision of excited argon atoms, whereas thermionic emission is by far insufficient to provide the necessary electrons.

  1. Ozone generation in a kHz-pulsed He-O2 capillary dielectric barrier discharge operated in ambient air

    NASA Astrophysics Data System (ADS)

    Sands, Brian L.; Ganguly, Biswa N.

    2013-12-01

    The generation of reactive oxygen species using nonequilibrium atmospheric pressure plasma jet devices has been a subject of recent interest due to their ability to generate localized concentrations from a compact source. To date, such studies with plasma jet devices have primarily utilized radio-frequency excitation. In this work, we characterize ozone generation in a kHz-pulsed capillary dielectric barrier discharge configuration comprised of an active discharge plasma jet operating in ambient air that is externally grounded. The plasma jet flow gas was composed of helium with an admixture of up to 5% oxygen. A unipolar voltage pulse train with a 20 ns pulse risetime was used to drive the discharge at repetition rates between 2-25 kHz. Using UVLED absorption spectroscopy centered at 255 nm near the Hartley-band absorption peak, ozone was detected over 1 cm from the capillary axis. We observed roughly linear scaling of ozone production with increasing pulse repetition rate up to a "turnover frequency," beyond which ozone production steadily dropped and discharge current and 777 nm O(5P→5S°) emission sharply increased. The turnover in ozone production occurred at higher pulse frequencies with increasing flow rate and decreasing applied voltage with a common energy density of 55 mJ/cm3 supplied to the discharge. The limiting energy density and peak ozone production both increased with increasing O2 admixture. The power dissipated in the discharge was obtained from circuit current and voltage measurements using a modified parallel plate dielectric barrier discharge circuit model and the volume-averaged ozone concentration was derived from a 2D ozone absorption measurement. From these measurements, the volume-averaged efficiency of ozone production was calculated to be 23 g/kWh at conditions for peak ozone production of 41 mg/h at 11 kV applied voltage, 3% O2, 2 l/min flow rate, and 13 kHz pulse repetition rate, with 1.79 W dissipated in the discharge.

  2. Evaluation of the Submerged Discharge of Dredged Material Slurry During Pipeline Dredge Operations

    DTIC Science & Technology

    1978-08-01

    turbulentI flow of the fluid mud wave the friction factor becomes virtually independent of Reynolds number and is determined solely by the relative...viscosity of the fluid mud. In the laboratory test program, head wave Reynolds numbers fell in the turbulent regime, and the bottom friction factor was...to prototype, the bottom friction factor was constant. Friction conditions at the upper inter- face are governed primarily by Froude number with little

  3. Corrective action plan for CAU Number 339: Area 12 Fleet Operations, Steam Cleaning Discharge Area, Nevada Test Site

    SciTech Connect

    1997-05-01

    The purpose of this Corrective Action Plan (CAP) is to provide the method for implementing the corrective action alternative as provided in the Corrective Action Decision Document (CADD). Detailed information of the site history and results of previous characterizations can be found in the Work Plan, the Preliminary Investigation Report, and the Phase 2 Characterization Report. Previous characterization investigations were completed as a condition of the Temporary Water Pollution Control Permit issued by the Nevada Division of Environmental Protection (NDEP) on July 14, 1992. The scope of this report is to prepare a CAP based upon the selected remedial alternative for closure of the Area 12, Building 12-16 Fleet Operations steam cleaning discharge area. The effluent discharge area has been impacted by volatile organic compounds (VOCs) and total petroleum hydrocarbons (TPH) as oil. The maximum hydrocarbon and VOC concentrations detected in the Preliminary and Phase 2 Site Characterization Investigations are summarized.

  4. Observations of soft X-ray emission and plasma dynamics of a compact capillary discharge operated in xenon

    SciTech Connect

    Valenzuela, J. C.; Wyndham, E. S.; Favre, M.; Chuaqui, H.

    2013-09-15

    We report observations of a low stored energy, low inductance compact capillary discharge operated in xenon. Even though the stored electrical energy is less than 1 J, significant output in the optical windows at 110 and 135 Å is measured. The soft X-ray emission is time-resolved and the conversion energy of the source is obtained. A lower bound to the conversion efficiency at 110 Å ± 2% and 135 Å ± 1% of 3.6% and 1.6% is obtained, respectively. The use of moiré-schlieren optical diagnostic allows the evolution of the line electron density. In particular, we observe a significant degree of compression in a tight on axis pinch as well as radial compression waves. The temporal evolution of the X-ray emission, which occurs during the current reversal and later, is discussed in relation to work in argon discharges and in relation to model calculations.

  5. Experimental investigation on a diode-pumped cesium-vapor laser stably operated at continuous-wave and pulse regime.

    PubMed

    Chen, Fei; Xu, Dongdong; Gao, Fei; Zheng, Changbin; Zhang, Kuo; He, Yang; Wang, Chunrui; Guo, Jin

    2015-05-04

    Employing a fiber-coupled diode-laser with a center wavelength of 852.25 nm and a line width of 0.17 nm, experimental investigation on diode-end-pumped cesium (Cs) vapor laser stably operated at continuous-wave (CW) and pulse regime is carried out. A 5 mm long cesium vapor cell filled with 60 kPa helium and 20 kPa ethane is used as laser medium. Using an output coupler with reflectivity of 48.79%, 1.26 W 894.57 nm CW laser is obtained at an incident pump power of 4.76 W, corresponding an optical-optical efficiency of 26.8% and a slope-efficiency of 28.8%, respectively. The threshold temperature is 67.5 °C. Stable pulsed cesium laser with a maximum average output power of 2.6 W is obtained at a repetition rate of 76 Hz, and the pulse repetition rate can be extend to 1 kHz with a pulse width of 18 μs.

  6. Extension of operation regimes and investigation of three-dimensional currentless plasmas in the Large Helical Device

    NASA Astrophysics Data System (ADS)

    Kaneko, O.; Yamada, H.; Inagaki, S.; Jakubowski, M.; Kajita, S.; Kitajima, S.; Kobayashi; Koga, K.; Morisaki, T.; Morita, S.; Mutoh, T.; Sakakibara, S.; Suzuki, Y.; Takahashi, H.; Tanaka, K.; Toi, K.; Yoshimura, Y.; Akiyama, T.; Asahi, Y.; Ashikawa, N.; Chikaraishi, H.; Cooper, A.; Darrow, D. S.; Drapiko, E.; Drewelow, P.; Du, X.; Ejiri, A.; Emoto, M.; Evans, T.; Ezumi, N.; Fujii, K.; Fukuda, T.; Funaba, H.; Furukawa, M.; Gates, D. A.; Goto, M.; Goto, T.; Guttenfelder, W.; Hamaguchi, S.; Hasuo, M.; Hino, T.; Hirooka, Y.; Ichiguchi, K.; Ida, K.; Idei, H.; Ido, T.; Igami, H.; Ikeda, K.; Imagawa, S.; Imai, T.; Isobe, M.; Itagaki, M.; Ito, T.; Itoh, K.; Itoh, S.; Iwamoto, A.; Kamiya, K.; Kariya, T.; Kasahara, H.; Kasuya, N.; Kato, D.; Kato, T.; Kawahata, K.; Koike, F.; Kubo, S.; Kumazawa, R.; Kuwahara, D.; Lazerson, S.; Lee, H.; Masuzaki, S.; Matsuoka, S.; Matsuura, H.; Matsuyama, A.; Michael, C.; Mikkelsen, D.; Mitarai, O.; Mito, T.; Miyazawa, J.; Motojima, G.; Mukai, K.; Murakami, A.; Murakami, I.; Murakami, S.; Muroga, T.; Muto, S.; Nagaoka, K.; Nagasaki, K.; Nagayama, Y.; Nakajima, N.; Nakamura, H.; Nakamura, Y.; Nakanishi, H.; Nakano, H.; Nakano, T.; Narihara, K.; Narushima, Y.; Nishimura, K.; Nishimura, S.; Nishiura, M.; Nunami, Y. M.; Obana, T.; Ogawa, K.; Ohdachi, S.; Ohno, N.; Ohyabu, N.; Oishi, T.; Okamoto, M.; Okamoto, A.; Osakabe, M.; Oya, Y.; Ozaki, T.; Pablant, N.; Peterson, B. J.; Sagara, A.; Saito, K.; Sakamoto, R.; Sakaue, H.; Sasao, M.; Sato, K.; Sato, M.; Sawada, K.; Seki, R.; Seki, T.; Sergeev, V.; Sharapov, S.; Sharov, I.; Shimizu, A.; Shimozuma, T.; Shiratani, M.; Shoji, M.; Sudo, S.; Sugama, H.; Suzuki, C.; Takahata, K.; Takeiri, Y.; Takemura, Y.; Takeuchi, M.; Tamura, H.; Tamura, N.; Tanaka, H.; Tanaka, T.; Tingfeng, M.; Todo, Y.; Tokitani, M.; Tokunaga, K.; Tokuzawa, T.; Tsuchiya, H.; Tsumori, K.; Ueda, Y.; Vyacheslavov, L.; Watanabe, K. Y.; Watanabe, T.; Watanabe, T. H.; Wieland, B.; Yamada, I.; Yamada, S.; Yamamoto, S.; Yanagi, N.; Yasuhara, R.; Yokoyama, M.; Yoshida, N.; Yoshimura, S.; Yoshinaga, T.; Yoshinuma, M.; Komori, A.

    2013-10-01

    The progress of physical understanding as well as parameter improvement of net-current-free helical plasma is reported for the Large Helical Device since the last Fusion Energy Conference in Daejeon in 2010. The second low-energy neutral beam line was installed, and the central ion temperature has exceeded 7 keV, which was obtained by carbon pellet injection. Transport analysis of the high-Ti plasmas shows that the ion-thermal conductivity and viscosity decreased after the pellet injection although the improvement does not last long. The effort has been focused on the optimization of plasma edge conditions to extend the operation regime towards higher ion temperature and more stable high density and high beta. For this purpose a portion of the open helical divertors are being modified to the baffle-structured closed ones aimed at active control of the edge plasma. It is compared with the open case that the neutral pressure in the closed helical divertor increased by ten times as predicted by modelling. Studies of physics in a three-dimensional geometry are highlighted in the topics related to the response to a resonant magnetic perturbation at the plasma periphery such as edge-localized-mode mitigation and divertor detachment. Novel approaches of non-local and non-diffusive transport have also been advanced.

  7. Corrective Action Decision Document (CADD), Area 12 fleet operations steam cleaning discharge area, Nevada Test Site Corrective Action Unit 339

    SciTech Connect

    Bonn, J.F.

    1996-12-01

    This Corrective Action Decision Document (CADD) incorporates the methodology used for evaluating the remedial alternatives completed for a former steam cleaning discharge area at the Nevada Test Site (NTS). The former steam cleaning site is located in Area 12, east of the Fleet Operations Building 12-16. The discharge area has been impacted by Resource Conservation and Recovery Act (RCRA) F Listed volatile organic compounds (VOCs) and petroleum hydrocarbons waste. Based upon these findings, resulting from Phase 1 and Phase 2 site investigations, corrective action is required at the site. To determine the appropriate corrective action to be proposed, an evaluation of remedial alternatives was completed. The evaluation was completed using a Corrective Measures Study (CMS). Based on the results of the CMS, the favored closure alternative for the site is plugging the effluent discharge line, removing the sandbagged barrier, completing excavation of VOC impacted soils, and fencing the soil area impacted by total petroleum hydrocarbons (TPH), east of the discharge line and west of the soil berm. Management of the F Listed VOCs are dictated by RCRA. Due to the small volume of impacted soil, excavation and transportation to a Treatment Storage and Disposal Facility (TSDF) is the most practical method of management. It is anticipated that the TPH (as oil) impacted soils will remain in place based upon; the A through K Analysis, concentrations detected (maximum 8,600 milligrams per kilogram), expected natural degradation of the hydrocarbons over time, and the findings of the Phase 2 Investigation that vertical migration has been minimal.

  8. CONTROL OF LASER RADIATION PARAMETERS: Influence of a constant magnetic field on non-stationary operation regimes of solid-state ring lasers

    NASA Astrophysics Data System (ADS)

    Kravtsov, Nikolai V.; Chekina, S. N.

    2007-02-01

    The effect of a constant magnetic field on the nonlinear radiation dynamics of a monolithic chip ring Nd:YAG laser pumped by modulated radiation is studied experimentally. It is found that the application of a constant magnetic field to the active element of the solid-state ring laser operating in the non-stationary regime results in the displacement of the regions of existence of quasi-periodic and chaotic lasing regimes to the low-frequency region of pump power modulation. In addition, the application of a magnetic field to the active element of the laser gives rise to the spectral nonreciprocity.

  9. Experimental method to quantify the efficiency of the first two operational stages of nanosecond dielectric barrier discharge plasma actuators

    NASA Astrophysics Data System (ADS)

    Correale, G.; Avallone, F.; Starikovskiy, A. Yu

    2016-12-01

    A method to quantify the efficiency of the first two operational stages of a nanosecond dielectric barrier discharge (ns-DBD) plasma actuator is proposed. The method is based on the independent measurements of the energy of electrical pulses and the useful part of the energy which heats up the gas in the discharge region. Energy input is calculated via a back current shunt technique as the difference between the energy given and the energy reflected back. The ratio of the difference of the latter two quantities and the energy input gives the electrical efficiency (η E) of a ns-DBD. The extent of the energy deposited is estimated via Schlieren visualizations and infrared thermography measurements. Then, the ideal power flux obtained if all the inputted energy was converted into heat is calculated. Transient surface temperature was measured via infrared thermography and used to solve a 1D inverse heat transfer problem in a direction normal to the surface. It gives as output the actual power flux. The estimated ratio between the two power fluxes represents a quantification of the mechanical fluid efficiency (η FM) of a ns-DBD plasma actuator. Results show an inverse proportionality between η E, and η FM, and the thickness of the barrier. The efficiency of the first two operational stages of a ns-DBD is further defined as η  =  η E · η FM.

  10. Temporal changes in VOC discharge to surface water from a fractured rock aquifer during well installation and operation, Greenville, South Carolina

    USGS Publications Warehouse

    Vroblesky, D.A.; Robertson, J.F.

    1996-01-01

    Analysis of the vapor in passive vapor samplers retrieved from a streambed in fractured rock terrain implied that volatile organic carbon (VOC) discharge from ground water to surface water substantially increased following installation of a contaminant recovery well using air rotary drilling. The air rotary technique forced air into the aquifer near the stream. The injection produced an upward hydraulic gradient that appears to have transported water and contaminants from deeper parts of the aquifer through fractures into shallow parts of the aquifer. Once in the shallow flow regime, the contamination was transported to the stream, where it discharged during the next several weeks following well installation. After the recovery well was activated and began continuously pumping contaminated ground water to a treatment facility, the VOC concentrations in the stream bottom passive vapor samplers decreased to below detectable concentrations, suggesting that the withdrawal had captured the contaminated ground water that previously had discharged to the stream.

  11. Natural laminar-turbulent transition delay by dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Ustinov, Maxim; Kogan, Mikhail; Litvinov, Vladimir; Uspensky, Alexander

    2011-12-01

    The use dielectric barrier discharge for the delay of laminar turbulent transition excited by natural flow disturbances in a quiet wind-tunnel was investigated experimentally. Optimal electrodes location and the operational regime of high-voltage impulse generator provided maximal downstream shift of transition location were found. It was demonstrated that the 10% increase of the laminar part of boundary layer can be obtained using barrier discharge with the cross-flow electrodes. This gives up to 20% friction drag reduction.

  12. All-fiber passively mode-locked Tm-doped NOLM-based oscillator operating at 2-μm in both soliton and noisy-pulse regimes.

    PubMed

    Li, Jianfeng; Zhang, Zuxing; Sun, Zhongyuan; Luo, Hongyu; Liu, Yong; Yan, Zhijun; Mou, Chengbo; Zhang, Lin; Turitsyn, Sergei K

    2014-04-07

    A self-starting all-fiber passively mode-locked Tm(3+)-doped fiber laser based on nonlinear loop mirror (NOLM) is demonstrated. Stable soliton pulses centered at 2017.33 nm with 1.56 nm FWHM were produced at a repetition rate of 1.514 MHz with pulse duration of 2.8 ps and pulse energy of 83.8 pJ. As increased pump power, the oscillator can also operate at noise-like (NL) regime. Stable NL pulses with coherence spike width of 341 fs and pulse energy of up to 249.32 nJ was achieved at a center wavelength of 2017.24 nm with 21.33 nm FWHM. To the best of our knowledge, this is the first 2 µm region NOLM-based mode-locked fiber laser operating at two regimes with the highest single pulse energy for NL pulses.

  13. Hairpin resonator probes with frequency domain boxcar operation for time resolved density measurements in pulsed RF discharges

    NASA Astrophysics Data System (ADS)

    Peterson, David; Kummerer, Theresa; Coumou, David; Shannon, Steven

    2014-10-01

    In this work, microsecond time resolved electron density measurements in pulsed RF discharges are shown using an automated hairpin resonance probe using relatively low cost electronics, on par with normal Langmuir probe boxcar mode operation. A low cost signal generator is used to produce the applied microwave frequency and the reflected waveform is filtered to remove the RF component. The signal is then heterodyned with a simple frequency mixer to produce a dc signal read by an oscilloscope to determine the electron density. The applied microwave frequency is automatically shifted in small increments in a frequency boxcar routine through a Labview™program to determine the resonant frequency. A simple dc sheath correction is then easily applied since the probe is fully floating, producing low cost, high fidelity, and highly reproducible electron density measurements. The measurements are made in a capacitively coupled, parallel plate configuration in a 13.56 MHz, 50--200 W RF discharge pulsed at 500 Hz, 200 W, 50% duty cycle. The gas input ranged from 50--100 mTorr pure Ar or with 5--10% O/He mixtures.

  14. Investigation of the laser pumping power impact on the operating regimes of a laser passively Q-switched by a saturated absorber

    NASA Astrophysics Data System (ADS)

    Benarab, Mustapha; Mokdad, Rabah; Djellout, Hocine; Benfdila, Arezki; Lamrous, Omar; Meyrueis, Patrick

    2011-09-01

    We have adapted the point model for the study of an all-fiber laser doped with Nd3+ and Q-switched by a saturable fiber absorber doped with Cr4+. Calculations of the output power of the 1084 nm laser are considered as a function of the pump power supplied by a 790 nm laser diode. The analysis of the simulation results reveals the existence of pulsed, sinusoidal, and dc operating regimes.

  15. Calibration of a rainfall-runoff model at regional scale by optimising river discharge statistics: Performance analysis for the average/low flow regime

    NASA Astrophysics Data System (ADS)

    Lombardi, Laura; Toth, Elena; Castellarin, Attilio; Montanari, Alberto; Brath, Armando

    Traditional procedures for rainfall-runoff model calibration are generally based on the fit of individual values of simulated and observed hydrographs. We use here an alternative option that is carried out by matching, in the optimisation process, a set of streamflow statistics. Such an approach has the significant advantage to enable also a straightforward regional calibration of model parameters, based on the regionalisation of the selected statistics. The minimisation of the set of objective functions is carried out by using the AMALGAM algorithm, leading to the identification of behavioural parameter sets. The procedure is applied to a set of river basins located in central Italy: the basins are treated alternatively as gauged and ungauged and, as a term of comparison, the results obtained with a traditional time-domain calibration are also presented. With respect to previous applications of analogous procedures, we investigate here the identification of the target statistics depending on the purposes of the application, and in particular when the focus is on the reproduction of the low-flows. The results show that a suitable choice of the statistics to be optimised leads to interesting results in real world case studies as far as the reproduction of the different flow regimes is concerned.

  16. Hybrid radiation background monitoring in operational control and forecasting of environmental contamination by nuclear power station discharges

    SciTech Connect

    Ermeev, I.S.; Eremenko, V.A.; Makarov, Y.A.; Matueev, V.V.; Zhernov, V.S.

    1986-05-01

    Rapid developments in nuclear power have stimulated research on monitoring and forecasting environmental radiation pollution (ERP), and in particular the amounts, compositions, and distributions of radionuclides in the environment. A conceptual model is presented for hybrid environmental radiation pollution monitoring. When there is an emergency, the model operates in a fashion most closely corresponding to the actual meteorological conditions, and the ERP data given by the model enable one to distinguish changes due to the man-made component from random fluctuations in the natural background. The measurement system in general includes mobile and stationary data-acquisition facilities linked by wire or radio to the central point. The system also accumulates and stores data on the radiation environment, which are edited on the basis of radioactive, chemical, and other transformations. The purpose of hybrid monitoring is ultimately to analyze trends in order to detect elevated discharges and thus to output data to the regional monitoring system.

  17. Integrated coaxial-hollow micro dielectric-barrier-discharges for a large-area plasma source operating at around atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Sakai, Osamu; Kishimoto, Yutaka; Tachibana, Kunihide

    2005-02-01

    An integrated structure of coaxial-hollow micro dielectric-barrier-discharges has been developed by stacking two metal meshes covered with insulating material. The test panel has an effective area of 50 mm diameter in which hundreds of hollow structures are assembled with a unit hollow area of 0.2 × 1.7 mm2. He or N2 was used as the discharge gas in the pressure range from 20 to 100 kPa and the firing voltage was less than 2 kV, even at the maximum pressure. The intensity of each microdischarge was observed to be uniform over the whole area throughout the pressure range, and its time evolution during one discharge pulse was analysed through two-dimensional microscopic observation with a gated CCD camera. In a gas flow regime through the coaxial hollow structures, several significant changes of the discharge properties were observed, such as impurity reduction, decrease in discharge voltage and cooling of the neutral gas. The fundamental plasma parameters were measured using a single probe in the downstream region of microdischarges using an auxiliary flat electrode set apart from the mesh electrode plane. The occurrence of an extended glow with a length of some millimetres was observed in He but not in N2. The electron density derived by the probe data in He at 100 kPa was ~3 × 1011 cm-3, suggesting a value of more than 1012 cm-3 in the active microdischarge region.

  18. High density operation in H mode discharges by inboard launch pellet refuelling

    NASA Astrophysics Data System (ADS)

    Lang, P. T.; Gafert, J.; Gruber, O.; Kaufmann, M.; Lorenz, A.; Maraschek, M.; Mertens, V.; Neuhauser, J.; Salzmann, H.; ASDEX Upgrade Team

    2000-02-01

    Operating a tokamak at plasma densities near the empirical Greenwald limit bar neGw in H mode could yield significant advantages for a fusion reactor. Trying to avoid the strong confinement degradation observed with gas puff refuelling, pellet injection from the magnetic high field side was applied. Sufficient pellet particle flux was supplied to achieve persistent density rampup and to enable density control in H mode at a level beyond bar neGw for the first time. The pellet induced density increase decays in a fast phase with τ = 10 ms until about half of the latest pellet inventory remains, and decays thereafter to the base density on the particle confinement timescale with τ = 120 ms. The fast decay is the result of strong ELM events following each injected pellet, accompanied by a loss of energy, causing a transient reduction of the plasma energy content by convective heat flux. Recovery of the plasma energy after the ELM sequence takes place with τ = 25 ms, enabling transient operation at appropriately high densities without significant confinement degradation. To reach this scenario, however, confinement degradation caused by other factors must be inhibited. Other factors causing confinement degradation were found to be the increase of neutral gas pressure by pellet born gas puff at insufficient pumping speed or the occurrence of neoclassical tearing modes triggered by pellets when the temperatures close to rational surfaces were reduced too strongly.

  19. Barium Depletion in the NSTAR Discharge Cathode After 30,000 Hours of Operation

    NASA Technical Reports Server (NTRS)

    Polk, James E.; Capece, Angela M.; Mikellides, Ioannis G.; Katz, Ira

    2010-01-01

    Dispenser hollow cathodes rely on a consumable supply of barium released by impregnant materials in the pores of a tungsten matrix to maintain a low work function surface. Examinations of cathode inserts from long duration ion engine tests show deposits of tungsten at the downstream end that appear to block the flow of barium from the interior. In addition, a numerical model of barium transport in the insert plasma indicates that the barium partial pressure in the insert may exceed the equilibrium vapor pressure of the dominant barium-producing reaction, and it was postulated previously that this would suppress barium loss in the upstream part of the insert. New measurements of the depth of barium depletion from a cathode insert operated for 30,352 hours reveal that barium loss is confined to a narrow region near the downstream end, confirming this hypothesis.

  20. Numerical simulation of operation modes in atmospheric pressure uniform barrier discharge excited by a saw-tooth voltage

    NASA Astrophysics Data System (ADS)

    Li, Xuechen; Niu, Dongying; Yin, Zengqian; Fang, Tongzhen; Wang, Long

    2012-08-01

    The characteristics of dielectric barrier discharge excited by a saw-tooth voltage are simulated in atmospheric pressure helium based on a one-dimensional fluid model. A stepped discharge is obtained per half voltage cycle with gas gap width less than 2 mm by the simulation, which is different to the pulsed discharge excited by a sinusoidal voltage. For the stepped discharge, the plateau duration increases with increasing the voltage amplitude and decreasing the gas gap. Therefore, uniform discharge with high temporal duty ratio can be realized with small gap through increasing the voltage amplitude. The maximal densities of both electron and ion appear near the anode and the electric field is almost uniformly distributed along the gap, which indicates that the stepped discharge belongs to a Townsend mode. In contrast to the stepped discharge with small gas gap, a pulsed discharge can be obtained with large gas gap. Through analyzing the spatial density distributions of electron and ion and the electric field, the pulsed discharge is in a glow mode. The voltage-current (V-I) characteristics are analyzed for the above mentioned discharges under different gas gaps, from which the different discharge modes are verified.

  1. Generation of trains of ultrashort microwave pulses by two coupled helical gyro-TWTs operating in regimes of amplification and nonlinear absorption

    NASA Astrophysics Data System (ADS)

    Ginzburg, N. S.; Denisov, G. G.; Vilkov, M. N.; Sergeev, A. S.; Zotova, I. V.; Samsonov, S. V.; Mishakin, S. V.

    2017-02-01

    Based on a time-domain model, we demonstrate that a periodic train of powerful ultrashort microwave pulses can be generated in an electron oscillator consisting of two coupled helically corrugated gyrotron travelling wave tubes (gyro-TWTs) operating in regimes of amplification and saturable absorption, respectively. The mechanism of pulse formation in such an oscillator is based on the effect of passive mode-locking widely used in laser physics. Saturable absorption can be implemented in a gyro-TWT in the Kompfner dip regime by a proper matching of the guiding magnetic field. According to simulations with the parameters of an experimentally realized Ka-band gyro-TWT, the peak power of generated pulses with a duration of 200 ps can achieve 400 kW.

  2. Removal of organic micro-pollutants from solid waste landfill leachate in membrane bioreactor operated without excess sludge discharge.

    PubMed

    Boonyaroj, V; Chiemchaisri, C; Chiemchaisri, W; Yamamoto, K

    2012-01-01

    Two-stage membrane bioreactor (MBR) system was applied to the treatment of landfill leachate from a solid waste disposal site in Thailand. The first stage anoxic reactor was equipped with an inclined tube module for sludge separation. It was followed by an aerobic stage with a hollow fiber membrane module for solid liquid separation. Mixed liquor sludge from the aerobic reactor was re-circulated back to anoxic reactor in order to maintain constant mixed liquor suspended solids (MLSS) concentration in the aerobic reactor. The removal of micro-pollutants from landfill leachate along the treatment period of 300 days was monitored. The results indicated that two-stage MBRs could remove biochemical oxygen demand (BOD), chemical oxygen demand (COD) and NH(4)(+) by 97, 87 and 91% at steady operating condition. Meanwhile organic micro-pollutant removals were 50-76%. The removal efficiencies varied according to the hydrophobic characteristic of compounds but they were improved during long-term MBR operation without sludge discharge.

  3. Closure report for CAU 339: Area 12 Fleet Operations steam-cleaning discharge area, Nevada Test Site

    SciTech Connect

    1997-12-01

    This Closure Report (CR) provides documentation of the completed corrective action at the Area 12 Fleet Operations site located in the southeast portion of the Area 12 Camp at the Nevada Test Site (NTS). Field work was performed in July 1997 as outlined in the Corrective Action Plan (CAP). The CAP was approved by the Nevada Division of Environmental Protection (NDEP) in June 1997. This site is identified in the Federal Facility Agreement and Consent Order (FFACO) as Corrective Action Site (CAS) Number 12-19-01 and is the only CAS in Corrective Action Unit (CAU) 339. The former Area 12 Fleet Operations Building 12-16 functioned as a maintenance facility for light- and heavy-duty vehicles from approximately 1965 to January 1993. Services performed at the site included steam-cleaning, tire service, and preventative maintenance on vehicles and equipment. Past activities impacted the former steam-cleaning discharge area with volatile organic compounds (VOCs) and total petroleum hydrocarbons (TPH) as oil.

  4. Dynamical regimes of a pH-oscillator operated in two mass-coupled flow-through reactors.

    PubMed

    Pešek, Oldřich; Schreiberová, Lenka; Schreiber, Igor

    2011-05-28

    We present results of experiments focused on emergent and cooperative dynamics in a system of two coupled flow-through stirred reaction cells with diffusion-like mass exchange and a strongly nonlinear chemical reaction between hydrogen peroxide and thiosulphate catalysed by cupric ions in diluted solution of sulphuric acid. Due to complex mechanism, in which a crucial role is played by hydrogen and/or hydroxide ions, dynamics in a single cell entail multiple stationary states, excitability and oscillations conveniently indicated by measuring pH. When coupled, the system shows a plethora of dynamical regimes depending on the coupling strength and flow rate. Under certain conditions both cells display dynamics close to that in the absence of coupling, but majority of the regimes are emergent and cannot be deduced from dynamics of decoupled reactors. The most prominent is a stationary state maintaining highly acidic values of pH in one of the reactors and weakly acidic in the other. When each cell is set to display excitability and the coupled system is externally perturbed, the cells may cooperate and transmit excitations elicited by pulsed perturbations in one cell to the other. Periodic pulses induce firing patterns marked by a various degree of propagated excitations and by being periodic or irregular.

  5. Laser frequency stabilisation by the Pound - Drever - Hall method using an acousto-optic phase modulator operating in the pure Raman - Nath diffraction regime

    SciTech Connect

    Baryshev, Vyacheslav N

    2012-04-30

    Frequency stabilisation of diode laser radiation has been implemented by the Pound - Drever - Hall method using a new acousto-optic phase modulator, operating in the pure Raman - Nath diffraction regime. It is experimentally shown that, as in the case of saturated-absorption spectroscopy in atomic vapour, the spatial divergence of the frequency-modulated output spectrum of this modulator does not interfere with obtaining error signals by means of heterodyne frequency-modulation spectroscopy with a frequency discriminator based on a high-Q Fabry - Perot cavity with finesse of several tens of thousands.

  6. Gallbladder removal - laparoscopic - discharge

    MedlinePlus

    Cholecystectomy laparoscopic - discharge; Cholelithiasis - laparoscopic discharge; Biliary calculus - laparoscopic discharge; Gallstones - laparoscopic discharge; Cholecystitis - laparoscopic discharge

  7. Interacting particles on the line and Dunkl intertwining operator of type A: application to the freezing regime

    NASA Astrophysics Data System (ADS)

    Andraus, Sergio; Katori, Makoto; Miyashita, Seiji

    2012-10-01

    We consider a one-dimensional system of Brownian particles that repel each other through a logarithmic potential. We study two formulations for the system and the relation between them. The first, Dyson’s Brownian motion model, has an interaction coupling constant determined by the parameter β > 0. When β = 1, 2 and 4, this model can be regarded as a stochastic realization of the eigenvalue statistics of Gaussian random matrices. The second system comes from Dunkl processes, which are defined using differential-difference operators (Dunkl operators) associated with finite abstract vector sets called root systems. When the type-A root system is specified, Dunkl processes constitute a one-parameter system similar to Dyson’s model, with the difference that its particles interchange positions spontaneously. We prove that the type-A Dunkl processes with parameter k > 0 starting from any symmetric initial configuration are equivalent to Dyson’s model with the parameter β = 2k. We focus on the intertwining operators, since they play a central role in the mathematical theory of Dunkl operators, but their general closed form is not yet known. Using the equivalence between symmetric Dunkl processes and Dyson’s model, we extract the effect of the intertwining operator of type A on symmetric polynomials from these processes’ transition probability densities. In the strong coupling limit, the intertwining operator maps all symmetric polynomials onto a function of the sum of their variables. In this limit, Dyson’s model freezes, and it becomes a deterministic process with a final configuration proportional to the roots of the Hermite polynomials multiplied by the square root of the process time, while being independent of the initial configuration.

  8. Generation of GW radiation pulses from a VUV free-electron laser operating in the femtosecond regime.

    PubMed

    Ayvazyan, V; Baboi, N; Bohnet, I; Brinkmann, R; Castellano, M; Castro, P; Catani, L; Choroba, S; Cianchi, A; Dohlus, M; Edwards, H T; Faatz, B; Fateev, A A; Feldhaus, J; Flöttmann, K; Gamp, A; Garvey, T; Genz, H; Gerth, Ch; Gretchko, V; Grigoryan, B; Hahn, U; Hessler, C; Honkavaara, K; Hüning, M; Ischebeck, R; Jablonka, M; Kamps, T; Körfer, M; Krassilnikov, M; Krzywinski, J; Liepe, M; Liero, A; Limberg, T; Loos, H; Luong, M; Magne, C; Menzel, J; Michelato, P; Minty, M; Müller, U-C; Nölle, D; Novokhatski, A; Pagani, C; Peters, F; Pflüger, J; Piot, P; Plucinski, L; Rehlich, K; Reyzl, I; Richter, A; Rossbach, J; Saldin, E L; Sandner, W; Schlarb, H; Schmidt, G; Schmüser, P; Schneider, J R; Schneidmiller, E A; Schreiber, H-J; Schreiber, S; Sertore, D; Setzer, S; Simrock, S; Sobierajski, R; Sonntag, B; Steeg, B; Stephan, F; Sytchev, K P; Tiedtke, K; Tonutti, M; Treusch, R; Trines, D; Türke, D; Verzilov, V; Wanzenberg, R; Weiland, T; Weise, H; Wendt, M; Will, I; Wolff, S; Wittenburg, K; Yurkov, M V; Zapfe, K

    2002-03-11

    Experimental results are presented from vacuum-ultraviolet free-electron laser (FEL) operating in the self-amplified spontaneous emission (SASE) mode. The generation of ultrashort radiation pulses became possible due to specific tailoring of the bunch charge distribution. A complete characterization of the linear and nonlinear modes of the SASE FEL operation was performed. At saturation the FEL produces ultrashort pulses (30-100 fs FWHM) with a peak radiation power in the GW level and with full transverse coherence. The wavelength was tuned in the range of 95-105 nm.

  9. Pancreatitis - discharge

    MedlinePlus

    Chronic pancreatitis - discharge; Pancreatitis - chronic - discharge; Pancreatic insufficiency - discharge; Acute pancreatitis - discharge ... fluids through an intravenous (IV) tube in your vein and nutrition through a feeding tube or IV. ...

  10. Improving three-dimensional target reconstruction in the multiple scattering regime using the decomposition of the time-reversal operator

    NASA Astrophysics Data System (ADS)

    Zhang, Ting; Chaumet, Patrick C.; Sentenac, Anne; Belkebir, Kamal

    2016-12-01

    The singular vectors of the time reversal operator (décomposition de l'opérateur de retournement temporel, time reversal operator decomposition (DORT) processing) are often used for localizing small echogeneous targets in a cluttered environment. In this work, we show that they can also improve the imaging of relatively large and contrasted targets in a homogeneous environment. It is observed that non-linear inversion schemes, minimizing iteratively the discrepancy between experimental data and simulated field scattered by target estimates, are more efficient when the illuminations correspond to the DORT singular vectors. In addition, DORT preprocessing permits a drastic diminution of the data load and computer burden. This study is conducted with experimental microwave data of targets with size comparable or greater than the wavelength.

  11. Simulations of the effects of minimum-discharge schedules on the oxygen concentration of the discharge of Conowingo Dam. Final report

    SciTech Connect

    Dwyer, R.L.; Turner, M.A.

    1986-04-01

    It has been suggested that there may be an optimum discharge regime for the Conowingo Dam that may allow the discharge waters to meet the Maryland water-quality standard for dissolved oxygen (DO). To test the efficacy of various minimum-discharge regimes, existing simulation models of Conowingo Reservoir and the nontidal river below the dam were linked together by a numerical procedure. Specifically, the linking procedure converted the output from the Conowingo Reservoir model (daily average DO concentrations in the surface and bottom layers of the reservoir) into 15-minute or hourly values. Those values then served as inputs to an empirical procedure for the withdrawal of water from the reservoir by the dam's turbines. The withdrawal model estimated the relative amounts of water withdrawn from each of the reservoir layers as turbine discharge increased. Waters from the layers were mixed to make up the discharge water. Typical summer operating patterns, constrained by the minimum discharge requirements were tested. It was concluded that no feasible changes in operating regimes alone would allow the discharge DO to meet the State standard of 5 mg/l.

  12. On the bipolar resistive-switching characteristics of Al₂O₃- and HfO₂-based memory cells operated in the soft-breakdown regime

    SciTech Connect

    Goux, L. Fantini, A.; Nigon, R.; Strangio, S.; Degraeve, R.; Kar, G.; Chen, Y. Y.; Jurczak, M.; Raghavan, N.; De Stefano, F.; Afanas'ev, V. V.

    2014-10-07

    In this article, we investigate extensively the bipolar-switching properties of Al₂O₃- and HfO₂-based resistive-switching memory cells operated at low current down to <1 μA. We show that the switching characteristics differ considerably from those typically reported for larger current range (>15 μA), which we relate as intrinsic to soft-breakdown (SBD) regime. We evidence a larger impact of the used switching-oxide in this current range, due to lower density of oxygen-vacancy (V{sub o}) defects in the SBD regime. In this respect, deep resetting and large memory window may be achieved using the stoichiometric Al₂O₃ material due to efficient V{sub o} annihilation, although no complete erasure of the conductive-filament (CF) is obtained. We finally emphasize that the conduction may be described by a quantum point-contact (QPC) model down to very low current level where only a few V{sub o} defects compose the QPC constriction. The large switching variability inherent to this latter aspect is mitigated by CF shape tuning through adequate engineering of an Al₂O₃\\HfO₂ bilayer.

  13. Identifying discharge practice training needs.

    PubMed

    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.

  14. National scale operational mapping of burnt areas as a tool for the better understanding of contemporary wildfire patterns and regimes.

    PubMed

    Kontoes, Charalampos; Keramitsoglou, Iphigenia; Papoutsis, Ioannis; Sifakis, Nicolas I; Xofis, Panteleimon

    2013-08-21

    This paper presents the results of an operational nationwide burnt area mapping service realized over Greece for the years 2007-2011, through the implementation of the so-called BSM_NOA dedicated method developed at the National Observatory of Athens for post-fire recovery management. The method exploits multispectral satellite imagery, such as Landsat-TM, SPOT, FORMOSAT-2, WorldView and IKONOS. The analysis of fire size distribution reveals that a high number of fire events evolve to large and extremely large wildfires under favorable wildfire conditions, confirming the reported trend of an increasing fire-severity in recent years. Furthermore, under such conditions wildfires affect to a higher degree areas at high altitudes, threatening the existence of ecologically significant ecosystems. Finally, recent socioeconomic changes and land abandonment has resulted in the encroachment of former agricultural areas of limited productivity by shrubs and trees, resulting both in increased fuel availability and continuity, and subsequently increased burnability.

  15. National Scale Operational Mapping of Burnt Areas as a Tool for the Better Understanding of Contemporary Wildfire Patterns and Regimes

    PubMed Central

    Kontoes, Charalampos; Keramitsoglou, Iphigenia; Papoutsis, Ioannis; Sifakis, Nicolas I.; Xofis, Panteleimon

    2013-01-01

    This paper presents the results of an operational nationwide burnt area mapping service realized over Greece for the years 2007–2011, through the implementation of the so-called BSM_NOA dedicated method developed at the National Observatory of Athens for post-fire recovery management. The method exploits multispectral satellite imagery, such as Landsat-TM, SPOT, FORMOSAT-2, WorldView and IKONOS. The analysis of fire size distribution reveals that a high number of fire events evolve to large and extremely large wildfires under favorable wildfire conditions, confirming the reported trend of an increasing fire-severity in recent years. Furthermore, under such conditions wildfires affect to a higher degree areas at high altitudes, threatening the existence of ecologically significant ecosystems. Finally, recent socioeconomic changes and land abandonment has resulted in the encroachment of former agricultural areas of limited productivity by shrubs and trees, resulting both in increased fuel availability and continuity, and subsequently increased burnability. PMID:23966201

  16. Continuous anaerobic co-digestion of Ulva biomass and cheese whey at varying substrate mixing ratios: Different responses in two reactors with different operating regimes.

    PubMed

    Jung, Heejung; Kim, Jaai; Lee, Changsoo

    2016-12-01

    The feasibility of co-digestion of Ulva with whey was investigated at varying substrate mixing ratios in two continuous reactors run with increasing and decreasing proportions of Ulva, respectively. Co-digestion with whey proved beneficial to the biomethanation of Ulva, with the methane yield being greater by up to 1.6-fold in co-digestion phases than in the Ulva mono-digestion phases. The experimental reactors responded differently, in terms of process performance and community structure, to the changes in the substrate mixing ratio. This can be attributed to the different operating regimes between two reactors, which may have caused the microbial communities to develop in different ways to acclimate. Methanosaeta-related populations were the predominant methanogens responsible for the production of methane regardless of different substrate mixing ratios in both reactors. Considering the methane recovery and the Ulva treatment capacity, the optimal fraction of Ulva in the substrate mixture is suggested to be 50-75%.

  17. Co-operation and conflict under hard and soft contracting regimes: case studies from England and Wales

    PubMed Central

    2013-01-01

    Background This paper examines NHS secondary care contracting in England and Wales in a period which saw increasing policy divergence between the two systems. At face value, England was making greater use of market levers and utilising harder-edged service contracts incorporating financial penalties and incentives, while Wales was retreating from the 1990s internal market and emphasising cooperation and flexibility in the contracting process. But there were also cross-border spill-overs involving common contracting technologies and management cultures that meant that differences in on-the-ground contracting practices might be smaller than headline policy differences suggested. Methods The nature of real-world contracting behaviour was investigated by undertaking two qualitative case studies in England and two in Wales, each based on a local purchaser/provider network. The case studies involved ethnographic observations and interviews with staff in primary care trusts (PCTs) or local health boards (LHBs), NHS or Foundation trusts, and the overseeing Strategic Health Authority or NHS Wales regional office, as well as scrutiny of relevant documents. Results Wider policy differences between the two NHS systems were reflected in differing contracting frameworks, involving regional commissioning in Wales and commissioning by either a PCT, or co-operating pair of PCTs in our English case studies, and also in different oversight arrangements by higher tiers of the service. However, long-term relationships and trust between purchasers and providers had an important role in both systems when the financial viability of organisations was at risk. In England, the study found examples where both PCTs and trusts relaxed contractual requirements to assist partners faced with deficits. In Wales, news of plans to end the purchaser/provider split meant a return to less precisely-specified block contracts and a renewed concern to build cooperation between LHB and trust staff

  18. Flight tests of Viking parachute system in three Mach number regimes. 1: Vehicle description, test operations, and performance

    NASA Technical Reports Server (NTRS)

    Lundstrom, R. R.; Raper, J. L.; Bendura, R. J.; Shields, E. W.

    1974-01-01

    Flight qualifications for parachutes were tested on full-scale simulated Viking spacecraft at entry conditions for the Viking 1975 mission to Mars. The vehicle was carried to an altitude of 36.6 km for the supersonic and transonic tests by a 980.000 cu m balloon. The vehicles were released and propelled to test conditions with rocket engines. A 117,940 cu m balloon carried the test vehicle to an altitude of 27.5 km and the conditions for the subsonic tests were achieved in free fall. Aeroshell separation occurred on all test vehicles from 8 to 14 seconds after parachute deployment. This report describes: (1) the test vehicle; (2) methods used to insure that the test conditions were achieved; and (3) the balloon system design and operations. The report also presents the performance data from onboard and ground based instruments and the results from a statistical trajectory program which gives a continuous history of test-vehicle motions.

  19. High repetition rate operation of a photoinitiated impulse-enhanced electrically excited CO2 laser discharge using a burst-mode technique

    NASA Astrophysics Data System (ADS)

    Nikumb, S. K.; Seguin, H. J. J.; Seguin, V. A.; Presakarchuk, D.

    1988-10-01

    The incorporation of a gating signal into the trigger circuit of a photoinitiated, impulse-enhanced, electrically excited (PIE) laser system has permitted high-power, pulsed operation of a normally cw CO2 discharge. The 40 liter gain medium has been run at repetition rates approaching 1 kHz utilizing this approach. Plasma uniformity and stability have been significantly enhanced, such that a factor of two increase in electrical power deposition into the excited volume has been achieved. Results suggest that pulsed performance considerably in excess of that achievable under cw operating conditions can be realized through the adoption of this simple modification to the PIE ionization process.

  20. Approaches for derivation of environmental quality criteria for substances applied in risk assessment of discharges from offshore drilling operations.

    PubMed

    Altin, Dag; Frost, Tone Karin; Nilssen, Ingunn

    2008-04-01

    In order to achieve the offshore petroleum industries "zero harm" goal to the environment, the environmental impact factor for drilling discharges was developed as a tool to identify and quantify the environmental risks associated with disposal of drilling discharges to the marine environment. As an initial step in this work the main categories of substances associated with drilling discharges and assumed to contribute to toxic or nontoxic stress were identified and evaluated for inclusion in the risk assessment. The selection were based on the known toxicological properties of the substances, or the total amount discharged together with their potential for accumulation in the water column or sediments to levels that could be expected to cause toxic or nontoxic stress to the biota. Based on these criteria 3 categories of chemicals were identified for risk assessment the water column and sediments: Natural organic substances, metals, and drilling fluid chemicals. Several approaches for deriving the environmentally safe threshold concentrations as predicted no effect concentrations were evaluated in the process. For the water column consensus were reached for using the species sensitivity distribution approach for metals and the assessment factor approach for natural organic substances and added drilling chemicals. For the sediments the equilibrium partitioning approach was selected for all three categories of chemicals. The theoretically derived sediment quality criteria were compared to field-derived threshold effect values based on statistical approaches applied on sediment monitoring data from the Norwegian Continental Shelf. The basis for derivation of predicted no effect concentration values for drilling discharges should be consistent with the principles of environmental risk assessment as described in the Technical Guidance Document on Risk Assessment issued by the European Union.

  1. Lung surgery - discharge

    MedlinePlus

    Thoracotomy - discharge; Lung tissue removal - discharge; Pneumonectomy - discharge; Lobectomy - discharge; Lung biopsy - discharge; Thoracoscopy - discharge; Video-assisted thoracoscopic surgery - discharge; VATS - ...

  2. Statistical analysis of the effect of dielectric barrier discharge (DBD) operating parameters on the surface processing of poly(methylmethacrylate) film

    NASA Astrophysics Data System (ADS)

    Liu, Chaozong; Brown, Norman M. D.; Meenan, Brian J.

    2005-02-01

    A dielectric barrier discharge (DBD) plasma, operating in air at atmospheric pressure, has been used to induce changes in the surface properties of poly(methylmethacrylate) (PMMA) films. The relative effects that key DBD operating parameters, specifically: discharge power, electrode gap and duration of exposure have on producing chemical and microstructural changes in the polymer surface region have been investigated. The approach taken involves the application of an orthogonal array experimental design and statistical analysis methodology. The various data sets obtained from these analyses have been used to develop an equation in which induced changes in the surface properties of the DBD modified PMMA films are expressed in terms of the effectiveness of the various processing parameters in producing them. In general, the results obtained clearly indicate that DBD plasma processing is an effective method for the controlled surface modification of PMMA. Relatively short exposures to the atmospheric pressure discharge produces a significant amount of oxygen incorporation at the surface as indicted by a pronounced reduction in water contact angle. Analysis of the role of each of the operating parameters concerned shows that they do indeed have selective effectiveness for inducing resultant surface modification. Duration of exposure to the DBD plasma, expressed here as the number of treatment cycles at a given speed of specimen transit through the electrode gap, was found to play a major role in decreasing the surface wettability of PMMA. Conversely, the magnitude of the discharge power was not a significant parameter in this regard. In contrast, the value of the applied power played the dominant role in achieving the observed enrichment of the surface oxygen abundance, as measured by XPS, with the duration of exposure to the discharge playing a secondary role in this case. The nature and scale of the induced surface changes that originate from the various processing

  3. Pre-breakdown evaluation of gas discharge mechanisms in microgaps

    SciTech Connect

    Semnani, Abbas; Peroulis, Dimitrios; Venkattraman, Ayyaswamy; Alexeenko, Alina A.

    2013-04-29

    The individual contributions of various gas discharge mechanisms to total pre-breakdown current in microgaps are quantified numerically. The variation of contributions of field emission and secondary electron emission with increasing electric field shows contrasting behavior even for a given gap size. The total current near breakdown decreases rapidly with gap size indicating that microscale discharges operate in a high-current, low-voltage regime. This study provides the first such analysis of breakdown mechanisms and aids in the formulation of physics-based theories for microscale breakdown.

  4. Kinetic simulations of magnetized capacitively coupled discharges

    NASA Astrophysics Data System (ADS)

    Trieschmann, Jan; Shihab, Mohammed; Eremin, Denis; Brinkmann, Ralf Peter; Schulze, Julian; Mussenbrock, Thomas

    2012-10-01

    Capacitive high frequency discharges are of crucial importance in the context of plasma etching, deposition and surface modification. As these single or multiple frequency discharges are oftentimes operated at low pressures of less than a few pascal, a high plasma density is commonly achieved with the use of external magnetic fields. In this work kinetic simulations are used to investigate the effect of inhomogeneous external magnetic fields on the discharge dynamics in a strongly nonlocal pressure regime. We found that capacitively coupled discharges can be largely asymmetrized by applying strong magnetic fields in front of a given target electrode. This not only has an effect on the plasma density, but also on the ion energy distribution functions (IEDF) at the electrodes and on the acceleration of fast electrons in the plasma sheath regions. In consequence in the discharge currents a generation of higher harmonics of the driving frequency can be observed. We investigate these scenarios in terms of 1D-3V Particle in Cell simulations.

  5. Dielectric barrier discharge-based plasma actuator operation in artificial atmospheres for validation of modeling and simulation

    SciTech Connect

    Mangina, R. S.; Enloe, C. L.; Font, G. I.

    2015-11-15

    We present an experimental case study of time-resolved force production by an aerodynamic plasma actuator immersed in various mixtures of electropositive (N{sub 2}) and electronegative gases (O{sub 2} and SF{sub 6}) at atmospheric pressure using a fixed AC high-voltage input of 16 kV peak amplitude at 200 Hz frequency. We have observed distinct changes in the discharge structures during both negative- and positive-going voltage half-cycles, with corresponding variations in the actuator's force production: a ratio of 4:1 in the impulse produced by the negative-going half-cycle of the discharge among the various gas mixtures we explored, 2:1 in the impulse produced by the positive-going half-cycle, and cases in which the negative-going half-cycle dominates force production (by a ratio of 1.5:1), where the half-cycles produce identical force levels, and where the positive-going half cycle dominates (by a ratio of 1:5). We also present time-resolved experimental evidence for the first time that shows electrons do play a significant role in the momentum coupling to surrounding neutrals during the negative going voltage half-cycle of the N{sub 2} discharge. We show that there is sufficient macroscopic variation in the plasma that the predictions of numerical models at the microscopic level can be validated even though the plasma itself cannot be measured directly on those spatial and temporal scales.

  6. Discharge reductions--value for money?

    PubMed

    Morley, R G; Coates, R; Taylor, R H

    2004-12-01

    Through the Nuclear Liabilities Management Authority White Paper, the UK Government and the Regulators have signalled a commitment to further improving the operation of the regulatory regime and to its operating within the principles of proportionality, transparency, consistency and accountability which underpin the Government's approach to regulation in general. Particular emphasis is placed upon ensuring that there is greater consistency in the treatment of risk and hazard; proportionate and cost effective delivery of public, worker and environmental protection; and an open and transparently applied regulatory system. The paper uses the historical record of radioactive discharges from BNFL's Sellafield reprocessing site in the UK and seeks to identify what have been the key drivers for change, particularly over the past 20 years of significant discharge reductions. The paper examines the current context for ongoing and future discharges from the site, and the incorporation of the use of the concepts of best practicable environmental option and best practicable means. Intergovernmental commitments such as the OSPAR Sintra and Bremen statements and the developing UK policy framework are also considered, together with BNFL's work with a wide range of 'green' stakeholders. The paper outlines the principal components of BNFL's decision-making processes for discharge control and abatement; and how these interact with the relevant external pressures. It then analyses whether the overall drivers and outcomes align with the declared desire of the UK Government to ensure that the taxpayer receives value for money in the new national arrangements for managing historic nuclear liabilities.

  7. Radical prostatectomy - discharge

    MedlinePlus

    ... prostatectomy - discharge; Laparoscopic radical prostatectomy - discharge; LRP - discharge; Robotic-assisted laparoscopic prostatectomy - discharge ; RALP - discharge; Pelvic lymphadenectomy - discharge; Prostate cancer - prostatectomy

  8. A laser gyro with a four-mirror square resonator: formulas for simulating the dynamics of the synchronisation zone parameters of the frequencies of counterpropagating waves during the device operation in the self-heating regime

    SciTech Connect

    Bondarenko, E A

    2014-04-28

    For a laser gyro with a four-mirror square resonator we have developed a mathematical model, which allows one to simulate the temporal behaviour of the synchronisation zone parameters of the frequencies of counterpropagating waves in a situation when the device operates in the self-heating regime and is switched-on at different initial temperatures. (laser gyroscopes)

  9. Oil Discharge Reporting Requirements

    EPA Pesticide Factsheets

    If a facility or vessel discharges oil to navigable waters or adjoining shorelines, the owner/operator is required to follow certain federal reporting requirements. This fact sheet outlines those reporting requirements.

  10. Vaginal Discharge

    MedlinePlus

    ... also be on the lookout for symptoms of yeast infections, bacterial vaginosis and trichomoniasis, 3 infections that ... cause changes in your vaginal discharge.Signs of yeast infectionsWhite, cottage cheese-like dischargeSwelling and pain around ...

  11. Absolute nitrogen atom density measurements by two-photon laser-induced fluorescence spectroscopy in atmospheric pressure dielectric barrier discharges of pure nitrogen

    SciTech Connect

    Es-Sebbar, Et-Touhami; Sarra-Bournet, Christian; Naude, Nicolas; Gherardi, Nicolas; Massines, Francoise

    2009-10-01

    In this paper, two-photon absorption laser induced fluorescence spectroscopy is used to follow the nitrogen atom density in flowing dielectric barrier discharges fed with pure nitrogen and operating at atmospheric pressure. Two different dielectric barrier discharge regimes are investigated: the Townsend regime, which is homogeneous although operating at atmospheric pressure, and the more common filamentary regime. In both regimes, densities as high as 3x10{sup 14}/cm{sup 3} are detected. However, the N atoms kinetic formation depends on the discharge regime. The saturation level is reached more rapidly with a filamentary discharge. For a given discharge regime, the N atom density depends strongly on the energy dissipated in the plasma between the gas inlet and the measurement position, whether the energy is varied by varying the position of the measurements, the gas flow, or the dissipated power. Experiments performed in the postdischarge show that the N atom decay cannot be simply attributed to three-body recombination of atomic nitrogen with nitrogen molecules, meaning that other mechanisms such as surface recombination or gas impurities play a role.

  12. Temporally, spatially, and spectrally resolved barrier discharge produced in trapped helium gas at atmospheric pressure

    SciTech Connect

    Chiper, Alina Silvia; Popa, Gheorghe

    2013-06-07

    Experimental study was made on induced effects by trapped helium gas in the pulsed positive dielectric barrier discharge (DBD) operating in symmetrical electrode configuration at atmospheric pressure. Using fast photography technique and electrical measurements, the differences in the discharge regimes between the stationary and the flowing helium are investigated. It was shown experimentally that the trapped gas atmosphere (TGA) has notable impact on the barrier discharge regime compared with the influence of the flowing gas atmosphere. According to our experimental results, the DBD discharge produced in trapped helium gas can be categorized as a multi-glow (pseudo-glow) discharge, each discharge working in the sub-normal glow regime. This conclusion is made by considering the duration of current pulse (few {mu}s), their maximum values (tens of mA), the presence of negative slope on the voltage-current characteristic, and the spatio-temporal evolution of the most representative excited species in the discharge gap. The paper focuses on the space-time distribution of the active species with a view to better understand the pseudo-glow discharge mechanism. The physical basis for these effects was suggested. A transition to filamentary discharge is suppressed in TGA mode due to the formation of supplementary source of seed electrons by surface processes (by desorption of electrons due to vibrationally excited nitrogen molecules, originated from barriers surfaces) rather than volume processes (by enhanced Penning ionisation). Finally, we show that the pseudo-glow discharge can be generated by working gas trapping only; maintaining unchanged all the electrical and constructive parameters.

  13. New type of drift tubes for gas-discharge detectors operating in vacuum: Production technology and quality control

    NASA Astrophysics Data System (ADS)

    Azorskii, N. I.; Gusakov, Yu. V.; Elsha, V. V.; Enik, T. L.; Ershov, Yu. V.; Kekelidze, V. D.; Kislov, E. M.; Kolesnikov, A. O.; Madigozhin, D. T.; Movchan, S. A.; Polenkevich, I. A.; Potrebenikov, Yu. K.; Samsonov, V. A.; Shkarovskiy, S. N.; Sotnikov, A. N.; Volkov, A. D.; Zinchenko, A. I.

    2017-01-01

    A device for fabricating thin-wall (straw) drift tubes using polyethylene terephthalate film 36 μm thick by ultrasonic welding is described together with the technique for controlling their quality. The joint width amounts to 0.4-1.0 mm. The joint breaking strength is 31.9 kg/mm2. The argon leakage from a tube of volume 188.6 cm3 under a pressure gradient of 1.0 atm does not exceed 0.3 × 10-3 cm3/min, which is mainly related to the absence of metallization in the joint vicinity. The high strength, the low tensile creep due to the absence of glued layers, the small value of gas leakage makes the new tubes capable of reliable and long-term operation in vacuum, which is confirmed by the operation of 7168 straw tubes for two years in the NA62 experiment.

  14. The New English Quality Assurance Regime

    ERIC Educational Resources Information Center

    Brown, Roger

    2011-01-01

    England is developing a new quality assurance regime that will come into effect in October 2011. A new funding regime will operate from the following year, together with new rules to ease the participation of private higher education providers. This article describes and analyses the new quality and funding regimes. It argues that the greater…

  15. Anti-reflux surgery - discharge

    MedlinePlus

    ... fundoplication - discharge; Toupet fundoplication - discharge; Thal fundoplication - discharge; Hiatal hernia repair - discharge; Endoluminal fundoplication - discharge; GERD - fundoplication discharge; ...

  16. HOLLOW CARBON ARC DISCHARGE

    DOEpatents

    Luce, J.S.

    1960-10-11

    A device is described for producing an energetic, direct current, hollow, carbon-arc discharge in an evacuated container and within a strong magnetic field. Such discharges are particularly useful not only in dissociation and ionization of high energy molecular ion beams, but also in acting as a shield or barrier against the instreaming of lowenergy neutral particles into a plasma formed within the hollow discharge when it is used as a dissociating mechanism for forming the plasma. There is maintained a predetermined ratio of gas particles to carbon particles released from the arc electrodes during operation of the discharge. The carbon particles absorb some of the gas particles and are pumped along and by the discharge out of the device, with the result that smaller diffusion pumps are required than would otherwise be necessary to dispose of the excess gas.

  17. Bone marrow transplant - discharge

    MedlinePlus

    Transplant - bone marrow - discharge; Stem cell transplant - discharge; Hematopoietic stem cell transplant - discharge; Reduced intensity; Non-myeloablative transplant - discharge; Mini transplant - discharge; Allogenic bone marrow transplant - ...

  18. Statistical modelling of discharge behavior of atmospheric pressure dielectric barrier discharge

    SciTech Connect

    Tay, W. H.; Kausik, S. S.; Wong, C. S. Yap, S. L.; Muniandy, S. V.

    2014-11-15

    In this work, stochastic behavior of atmospheric pressure dielectric barrier discharge (DBD) has been investigated. The experiment is performed in a DBD reactor consisting of a pair of stainless steel parallel plate electrodes powered by a 50 Hz ac high voltage source. Current pulse amplitude distributions for different space gaps and the time separation between consecutive current pulses are studied. A probability distribution function is proposed to predict the experimental distribution function for the current pulse amplitudes and the occurrence of the transition regime of the pulse distribution. Breakdown voltage at different positions on the dielectric surface is suggested to be stochastic in nature. The simulated results based on the proposed distribution function agreed well with the experimental results and able to predict the regime of transition voltage. This model would be useful for the understanding of stochastic behaviors of DBD and the design of DBD device for effective operation and applications.

  19. Reduction of the uncertainties in the water level-discharge relation of a 1D hydraulic model in the context of operational flood forecasting

    NASA Astrophysics Data System (ADS)

    Habert, J.; Ricci, S.; Le Pape, E.; Thual, O.; Piacentini, A.; Goutal, N.; Jonville, G.; Rochoux, M.

    2016-01-01

    This paper presents a data-driven hydrodynamic simulator based on the 1-D hydraulic solver dedicated to flood forecasting with lead time of an hour up to 24 h. The goal of the study is to reduce uncertainties in the hydraulic model and thus provide more reliable simulations and forecasts in real time for operational use by the national hydrometeorological flood forecasting center in France. Previous studies have shown that sequential assimilation of water level or discharge data allows to adjust the inflows to the hydraulic network resulting in a significant improvement of the discharge while leaving the water level state imperfect. Two strategies are proposed here to improve the water level-discharge relation in the model. At first, a modeling strategy consists in improving the description of the river bed geometry using topographic and bathymetric measurements. Secondly, an inverse modeling strategy proposes to locally correct friction coefficients in the river bed and the flood plain through the assimilation of in situ water level measurements. This approach is based on an Extended Kalman filter algorithm that sequentially assimilates data to infer the upstream and lateral inflows at first and then the friction coefficients. It provides a time varying correction of the hydrological boundary conditions and hydraulic parameters. The merits of both strategies are demonstrated on the Marne catchment in France for eight validation flood events and the January 2004 flood event is used as an illustrative example throughout the paper. The Nash-Sutcliffe criterion for water level is improved from 0.135 to 0.832 for a 12-h forecast lead time with the data assimilation strategy. These developments have been implemented at the SAMA SPC (local flood forecasting service in the Haute-Marne French department) and used for operational forecast since 2013. They were shown to provide an efficient tool for evaluating flood risk and to improve the flood early warning system

  20. Numerical study of a helicon gas discharge

    NASA Astrophysics Data System (ADS)

    Batishchev, Oleg; Molvig, Kim

    2001-06-01

    Plasma sources based on the helicon gas discharge are widely used in industry [1] due to their high efficiency. We investigate performance of a particular helicon plasma sources designed for the VASIMR [2] plasma thruster. Specifically we are interested in the VX-10 configuration [3] operating with hydrogen or helium plasmas. Firstly, we use our zero-dimensional model to characterize plasma condition and composition [4]. Next we couple it to one-dimensional hybrid model [5] for a rarified gas flow in the system feeding pipe - quartz tube of the helicon. We perform numerical analysis of plasma source operation in different regimes. Results are compared and used to explain experimental data [3]. Finally, we'll discuss more detailed fully kinetic models for the gas and plasma species evolution in the helicon discharge with parameters typical to that of the VASIMR plasma thruster. [1] M.A. Lieberman and A.J.Lihtenberg, , 'Principles of plasma discharges and materials processing', Wiley, NY, 1994; [2] F.Chang-Diaz et al, Bull. APS 45 (7) 129, 2000; [3] J. Squire et al., Bull. APS 45 (7) 130, 2000; [4] O.Batishchev and Kim Molvig, AIAA technical paper 2000-3754, 2000; [5] O.Batishchev and Kim Molvig, AIAA technical paper 2001-0963, 2001.

  1. Generation of a diffuse brush-shaped plasma plume using a dielectric barrier discharge at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Li, Xuechen; Chu, Jingdi; Jia, Pengying; Zhang, Qi; Zhang, Chunyan; Dong, Lifang

    2016-11-01

    With argon used as working gas, a barrier discharge device composed of two diverging wire electrodes is developed to generate a diffuse brush-shaped plasma plume outside a wedged gap. The parameter range for plume generation and its discharge characteristics are studied through electrical and optical methods. The spatial and temporal evolution is implemented by fast photography to investigate the formation mechanism of the plume. At a lower voltage, it is found that the large-scale plume is a superposition of micro-discharge filaments gliding along the argon flow direction, which operate in a glow discharge regime. However, streamer-discharge branches appear stochastically on the gliding micro-discharge filaments under an overvoltage. Results also indicate that the plasma is in a non-equilibrium condition.

  2. INTENSE ENERGETIC GAS DISCHARGE

    DOEpatents

    Luce, J.S.

    1960-03-01

    A method and apparatus for initiating and sustaining an energetic gas arc discharge are described. A hollow cathode and a hollow anode are provided. By regulating the rate of gas flow into the interior of the cathode, the arc discharge is caused to run from the inner surface of the cathode with the result that adequate space-charge neutralization is provided inside the cathode but not in the main arc volume. Thus, the gas fed to the cathode is substantially completely ionized before it leaves the cathode, with the result that an energetic arc discharge can be maintained at lower operating pressures.

  3. Evaluation of Spatial Pattern of Altered Flow Regimes on a River Network Using a Distributed Hydrological Model

    PubMed Central

    Ryo, Masahiro; Iwasaki, Yuichi; Yoshimura, Chihiro; Saavedra V., Oliver C.

    2015-01-01

    Alteration of the spatial variability of natural flow regimes has been less studied than that of the temporal variability, despite its ecological importance for river ecosystems. Here, we aimed to quantify the spatial patterns of flow regime alterations along a river network in the Sagami River, Japan, by estimating river discharge under natural and altered flow conditions. We used a distributed hydrological model, which simulates hydrological processes spatiotemporally, to estimate 20-year daily river discharge along the river network. Then, 33 hydrologic indices (i.e., Indicators of Hydrologic Alteration) were calculated from the simulated discharge to estimate the spatial patterns of their alterations. Some hydrologic indices were relatively well estimated such as the magnitude and timing of maximum flows, monthly median flows, and the frequency of low and high flow pulses. The accuracy was evaluated with correlation analysis (r > 0.4) and the Kolmogorov–Smirnov test (α = 0.05) by comparing these indices calculated from both observed and simulated discharge. The spatial patterns of the flow regime alterations varied depending on the hydrologic indices. For example, both the median flow in August and the frequency of high flow pulses were reduced by the maximum of approximately 70%, but these strongest alterations were detected at different locations (i.e., on the mainstream and the tributary, respectively). These results are likely caused by different operational purposes of multiple water control facilities. The results imply that the evaluation only at discharge gauges is insufficient to capture the alteration of the flow regime. Our findings clearly emphasize the importance of evaluating the spatial pattern of flow regime alteration on a river network where its discharge is affected by multiple water control facilities. PMID:26207997

  4. Evaluation of Spatial Pattern of Altered Flow Regimes on a River Network Using a Distributed Hydrological Model.

    PubMed

    Ryo, Masahiro; Iwasaki, Yuichi; Yoshimura, Chihiro; Saavedra V, Oliver C

    2015-01-01

    Alteration of the spatial variability of natural flow regimes has been less studied than that of the temporal variability, despite its ecological importance for river ecosystems. Here, we aimed to quantify the spatial patterns of flow regime alterations along a river network in the Sagami River, Japan, by estimating river discharge under natural and altered flow conditions. We used a distributed hydrological model, which simulates hydrological processes spatiotemporally, to estimate 20-year daily river discharge along the river network. Then, 33 hydrologic indices (i.e., Indicators of Hydrologic Alteration) were calculated from the simulated discharge to estimate the spatial patterns of their alterations. Some hydrologic indices were relatively well estimated such as the magnitude and timing of maximum flows, monthly median flows, and the frequency of low and high flow pulses. The accuracy was evaluated with correlation analysis (r > 0.4) and the Kolmogorov-Smirnov test (α = 0.05) by comparing these indices calculated from both observed and simulated discharge. The spatial patterns of the flow regime alterations varied depending on the hydrologic indices. For example, both the median flow in August and the frequency of high flow pulses were reduced by the maximum of approximately 70%, but these strongest alterations were detected at different locations (i.e., on the mainstream and the tributary, respectively). These results are likely caused by different operational purposes of multiple water control facilities. The results imply that the evaluation only at discharge gauges is insufficient to capture the alteration of the flow regime. Our findings clearly emphasize the importance of evaluating the spatial pattern of flow regime alteration on a river network where its discharge is affected by multiple water control facilities.

  5. Plasma in a Pulsed Discharge Environment

    NASA Technical Reports Server (NTRS)

    Remy, J.; Bienier, L.; Salama, F.

    2005-01-01

    The plasma generated in a pulsed slit discharge nozzle is used to form molecular ions in an astrophysically relevant environment. The plasma has been characterized as a glow discharge in the abnormal regime. Laboratory studies help understand the formation processes of polycyclic aromatic hydrocarbon (PAH) ions that are thought to be the source of the ubiquitous unidentified infrared bands.

  6. Observation of dynamic interactions between fundamental and second-harmonic modes in a high-power sub-terahertz gyrotron operating in regimes of soft and hard self-excitation.

    PubMed

    Saito, Teruo; Tatematsu, Yoshinori; Yamaguchi, Yuusuke; Ikeuchi, Shinji; Ogasawara, Shinya; Yamada, Naoki; Ikeda, Ryosuke; Ogawa, Isamu; Idehara, Toshitaka

    2012-10-12

    Dynamic mode interaction between fundamental and second-harmonic modes has been observed in high-power sub-terahertz gyrotrons [T. Notake et al., Phys. Rev. Lett. 103, 225002 (2009); T. Saito et al. Phys. Plasmas 19, 063106 (2012)]. Interaction takes place between a parasitic fundamental or first-harmonic (FH) mode and an operating second-harmonic (SH) mode, as well as among SH modes. In particular, nonlinear excitation of the parasitic FH mode in the hard self-excitation regime with assistance of a SH mode in the soft self-excitation regime was clearly observed. Moreover, both cases of stable two-mode oscillation and oscillation of the FH mode only were observed. These observations and theoretical analyses of the dynamic behavior of the mode interaction verify the nonlinear hard self-excitation of the FH mode.

  7. Pulsed submicrosecond multichannel sliding discharges of opposite polarities: Filling of the discharge gap with spark channels

    SciTech Connect

    Trusov, K. K.

    2012-05-15

    Results are presented from measurements of the discharge current and the factor of the discharge gap filling with spark channels during pulsed sliding discharges of opposite polarities in Ne, Ar, and Xe on an aluminum oxide ceramic surface. The measurements were performed in the regime of single pulses of submi-crosecond duration at discharge voltages of 0-12 kV with two discharge chambers with different thicknesses of the ceramic plate (0.4 and 0.17 cm) and different electrode gap lengths (4 and 10.3 cm) at gas pressures of 30 and 100 kPa. The results obtained for discharges of opposite polarities are compared with one another, and common features of discharges in three gases are revealed. It is shown that the filling of the discharge gap with spark channels in the gases under study is more efficient in the case of the positive polarity of the discharge voltage, except Xe at a pressure of 100 kPa in the electrode gap of length 10.3 cm. The quasi-homogeneous regime of discharge in each of the three gases is attained easier at lower gas pressures. Comparison of the data on the filling factors of the discharge gap and the peak currents of opposite-polarity discharges for each gas at a given pressure indicates that the higher the discharge current, the more densely the discharge gap is filled with spark channels.

  8. Septoplasty - discharge

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000246.htm Septoplasty - discharge To use the sharing features on this page, please enable JavaScript. Septoplasty is surgery to correct any problems in the ...

  9. Osteomyelitis - discharge

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000297.htm Osteomyelitis - discharge To use the sharing features on this page, please enable JavaScript. You have osteomyelitis , a bone infection caused by bacteria or other ...

  10. Cirrhosis - discharge

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000290.htm Cirrhosis - discharge To use the sharing features on this page, please enable JavaScript. You have cirrhosis of the liver. Scar tissue forms and your ...

  11. Acoustic field effects on a negative corona discharge

    NASA Astrophysics Data System (ADS)

    Bálek, R.; Červenka, M.; Pekárek, S.

    2014-06-01

    For a negative corona discharge under atmospheric pressure in different regimes, we investigated the effects of an acoustic field both on its electrical parameters and on the change in its visual appearance. We found that the application of an acoustic field on the true corona discharge, for particular currents, decreases the discharge voltage. The application of an acoustic field on the discharge in the filamentary streamer regime substantially extends the range of currents for which the discharge voltage remains more or less constant, i.e. it allows a substantial increase in the power delivered to the discharge. The application of an acoustic field on the discharge causes the discharge to spread within the discharge chamber and consequently, a highly reactive non-equilibrium plasma is created throughout the inter-electrode space. Finally, our experimental apparatus radiates almost no acoustic energy from the discharge chamber.

  12. Pulse-Periodic Regimes of Kinetic Instabilities in the Non-Equilibrium Plasma of an Electron Cyclotron Resonance Discharge Maintained by Continuous-Wave Radiation of a 24 GHz Gyrotron

    NASA Astrophysics Data System (ADS)

    Mansfeld, D. A.; Viktorov, M. E.; Vodopyanov, A. V.

    2017-01-01

    We have experimentally discovered an instability, which manifests itself as precipitations of hot electrons occurring synchronously with generation of bursts of electromagnetic radiation, in the plasma of an electron cyclotron resonance discharge maintained by a high-power, continuous-wave radiation of a 24 GHz gyrotron, for the first time. The observed instability has the kinetic nature and is determined by the formation of the non-equilibrium velocity distribution of hot particles. Two possible explanations are proposed for the mechanism of wave excitation in a two-component plasma with a stationary source of non-equilibrium particles. The results of the studies performed are of interest for modeling of the dynamics of magnetospheric cyclotron masers.

  13. Assessment of economic impact of offshore and coastal discharge requirements on present and future operations in the Gulf of Mexico. Final report

    SciTech Connect

    Lindsey, R.

    1996-06-01

    The high potential costs of compliance associated with new effluent guidelines for offshore and coastal oil and gas operations could significantly affect the economics of finding, developing, and producing oil and gas in the Gulf of Mexico. This report characterizes the potential economic impacts of alternative treatment and discharge regulations for produced water on reserves and production in Gulf of Mexico coastal, territorial and outer continental shelf (OCS) waters, quantifying the impacts of both recent regulatory changes and possible more stringent requirements. The treatment technologies capable of meeting these requirements are characterized in terms of cost, performance, and applicability to coastal and offshore situations. As part of this analysis, an extensive database was constructed that includes oil and gas production forecasts by field, data on existing platforms, and the current treatment methods in place for produced water treatment and disposal on offshore facilities. This work provides the first comprehensive evaluation of the impacts of alternative regulatory requirements for produced water management and disposal in coastal and offshore areas of the Gulf of Mexico.

  14. Cardiac catheterization - discharge

    MedlinePlus

    Catheterization - cardiac - discharge; Heart catheterization - discharge: Catheterization - cardiac; Heart catheterization; Angina - cardiac catheterization discharge; CAD - cardiac catheterization discharge; Coronary artery disease - cardiac catheterization ...

  15. Newborn jaundice - discharge

    MedlinePlus

    ... Jaundice of the newborn - discharge; Neonatal hyperbilirubinemia - discharge; Breastfeeding jaundice - discharge; Physiologic jaundice - discharge Images Exchange transfusion - series Infant jaundice References Kaplan M, ...

  16. Kidney removal - discharge

    MedlinePlus

    ... nephrectomy - discharge; Open nephrectomy - discharge; Laparoscopic nephrectomy - discharge; Partial nephrectomy - discharge ... Plan to have someone drive you home from the hospital. DO NOT drive yourself home. You may ...

  17. Atrial fibrillation - discharge

    MedlinePlus

    Auricular fibrillation - discharge; A-fib - discharge; AF - discharge; Afib - discharge ... been in the hospital because you have atrial fibrillation . This condition occurs when your heart beats faster ...

  18. Estimating initial contaminant mass based on fitting mass-depletion functions to contaminant mass discharge data: Testing method efficacy with SVE operations data

    NASA Astrophysics Data System (ADS)

    Mainhagu, J.; Brusseau, M. L.

    2016-09-01

    The mass of contaminant present at a site, particularly in the source zones, is one of the key parameters for assessing the risk posed by contaminated sites, and for setting and evaluating remediation goals and objectives. This quantity is rarely known and is challenging to estimate accurately. This work investigated the efficacy of fitting mass-depletion functions to temporal contaminant mass discharge (CMD) data as a means of estimating initial mass. Two common mass-depletion functions, exponential and power functions, were applied to historic soil vapor extraction (SVE) CMD data collected from 11 contaminated sites for which the SVE operations are considered to be at or close to essentially complete mass removal. The functions were applied to the entire available data set for each site, as well as to the early-time data (the initial 1/3 of the data available). Additionally, a complete differential-time analysis was conducted. The latter two analyses were conducted to investigate the impact of limited data on method performance, given that the primary mode of application would be to use the method during the early stages of a remediation effort. The estimated initial masses were compared to the total masses removed for the SVE operations. The mass estimates obtained from application to the full data sets were reasonably similar to the measured masses removed for both functions (13 and 15% mean error). The use of the early-time data resulted in a minimally higher variation for the exponential function (17%) but a much higher error (51%) for the power function. These results suggest that the method can produce reasonable estimates of initial mass useful for planning and assessing remediation efforts.

  19. Performance and control of optimized shear discharges in JET

    NASA Astrophysics Data System (ADS)

    Bécoulet, A.; Eriksson, L.-G.; Baranov, Yu. F.; Borba, D. N.; Challis, C. D.; Conway, G. D.; Fuchs, V.; Gormezano, C.; Gowers, C. W.; Hawkes, N. C.; Hender, T. C.; Huysmans, G. T. A.; Joffrin, E.; Litaudon, X.; Lomas, P. J.; Maas, A.; Mayoral, M. L.; Parail, V. V.; Rimini, F. G.; Rochard, F.; Sarazin, Y.; Sips, A. C. C.; Söldner, F. X.; Zastrow, K.-D.; Zwingman, W. P.

    2000-06-01

    High performance discharges are routinely obtained on JET with low or reversed magnetic shear (s = (r/q)dq/dr), and the potential for steady state operation of such discharges is under investigation. With the use of the proper heating and fuelling, these `optimized shear' (OS) discharges exhibit an internal transport barrier (ITB), resulting in a strong peaking of the pressure profile, and thus in high fusion performance. These regimes have been extensively studied during the last (DD and DT) JET campaigns in order to promote this type of scenario as the basis for `advanced tokamak' operation. A review is given of the highest performance achieved on JET OS discharges during the last experimental campaigns, in both DD (up to 5.6 × 1016neutrons/s) and DT operation (fusion power up to 8.2 MW, ni0Ti0τE up to 1021 m-3 keV s). The role of the plasma edge is pointed out, as the power required to trigger an ITB is often higher than the H mode power threshold, leading to double barrier regimes. The presence of an H mode pedestal both modifies the ITB and induces edge bootstrap and ELM activity, which should be controlled to prolong such discharges. The operational procedure of optimization is then discussed, addressing the problems of ITB formation (power threshold, timing of the main heating phase, i.e. optimization of the target q profile, influence of the heating scheme, electron versus ion ITBs), ITB evolution (expansion of the ITB footpoint, H mode formation) and ITB termination (disruptive and/or `soft' MHD limits). Finally, the crucial problem of the route to steady state for such OS discharges is addressed, both in terms of ITB sustainment and control within the stability domain and in terms of edge pedestal control by means of impurity injection. The impurity behaviour is found, and examples of high performance discharges sustained for several energy confinement times are given (βN = 1.95, H89 = 2.3, Pfusioneq~10 MW, QDTeq~0.4 sustained for ~3 s). Extrapolation

  20. Effect of the Initial Load Parameters on the K-shell Output of Al Planar Wire Arrays Operating in the Microsecond Implosion Regime

    SciTech Connect

    Shishlov, A.; Chaikovsky, S.; Fedunin, A.; Fursov, F.; Kokshenev, V.; Kurmaev, N.; Labetsky, A.; Oreshkin, V.; Rousskikh, A.; Labetskaya, N.

    2009-01-21

    A set of microsecond implosion experiments was carried on the GIT-12 generator to study the radiative performance of Al planar wire arrays. The load parameters such as a wire diameter, a gap between the wires, the number of wires, and the total planar wire mass and width were varied during the experiments, however the implosion time and the peak implosion current were almost the same for all load configurations. This ensured equal energy deposition to the plasma due to kinetic mechanisms for all load configurations. Two implosion regimes with the implosion times of 1050 ns and 850 ns were investigated. The experimental data on the K-shell radiation yield and power at varying load parameters are presented.

  1. Post-Closure Monitoring Report for Corrective Action Unit 339: Area 12 Fleet Operations Steam Cleaning Discharge Area Nevada Test Site, Nevada

    SciTech Connect

    A. T. Urbon

    2001-08-01

    The Area 12 Fleet Operations Steam Cleaning site is located in the southeast portion of the Area 12 Camp at the Nevada Test Site (Figure 1). This site is identified in the Federal Facility Agreement and Consent Order (FFACO, 1996) as Corrective Action Site (CAS) 12-19-01 and is the only CAS assigned to Corrective Action Unit (CAU) 339. Post-closure sampling and inspection of the site were completed on March 23, 2001. Because of questionable representativeness and precision of the results, the site was resampled on June 12, 2001. Post-closure monitoring activities were scheduled biennially (every two years) in the Post-Closure Monitoring Plan provided in the December 1997 Closure Report for CAU 339: Area 12 Fleet Operations Steam Cleaning Discharge Area, Nevada Test Site (U.S. Department of Energy, Nevada Operations Office [DOE/NV], 1997). If after six years the rate of degradation appears to be so slow that the greatest concentration of total petroleum hydrocarbons (TPH) present at the site would not decay within 30 years of the site closure, the site will be reevaluated with consideration to enriching the impacted soil at the site to enhance the degradation process. A baseline for the site was established by sampling in 1997. Based on the recommendations from the 1999 post-closure monitoring report, samples were collected in 2000, earlier than originally proposed, because the 1999 sample results did not provide the expected decrease in TPH concentrations at the site. Sampling results from 2000 revealed favorable conditions for natural degradation at the CAU 339 site, but because of differing sample methods and heterogeneity of the soil, the data results from 2000 were not directly correlated with previous results. Post-closure monitoring activities for 2001 consisted of the following: Soil sample collection from three undisturbed plots (Plots A, B, and C, Figure 2); Sample analysis for TPH as oil and bio-characterization parameters (Comparative Enumeration Assay

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

    PubMed

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

    2015-03-20

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

  3. Nipple Discharge

    MedlinePlus

    ... If the ultrasound shows a lesion within a milk duct, you may need a biopsy to confirm that it's a papilloma or to exclude a cancer. Nipple discharge is rarely a sign of breast cancer. But it might be a sign of ...

  4. Effective discharge analysis of ecological processes in streams

    USGS Publications Warehouse

    Doyle, M.W.; Stanley, E.H.; Strayer, D.L.; Jacobson, R.B.; Schmidt, J.C.

    2005-01-01

    [1] Discharge is a master variable that controls many processes in stream ecosystems. However, there is uncertainty of which discharges are most important for driving particular ecological processes and thus how flow regime may influence entire stream ecosystems. Here the analytical method of effective discharge from fluvial geomorphology is used to analyze the interaction between frequency and magnitude of discharge events that drive organic matter transport, algal growth, nutrient retention, macroinvertebrate disturbance, and habitat availability. We quantify the ecological effective discharge using a synthesis of previously published studies and modeling from a range of study sites. An analytical expression is then developed for a particular case of ecological effective discharge and is used to explore how effective discharge varies within variable hydrologic regimes. Our results suggest that a range of discharges is important for different ecological processes in an individual stream. Discharges are not equally important; instead, effective discharge values exist that correspond to near modal flows and moderate floods for the variable sets examined. We suggest four types of ecological response to discharge variability: discharge as a transport mechanism, regulator of habitat, process modulator, and disturbance. Effective discharge analysis will perform well when there is a unique, essentially instantaneous relationship between discharge and an ecological process and poorly when effects of discharge are delayed or confounded by legacy effects. Despite some limitations the conceptual and analytical utility of the effective discharge analysis allows exploring general questions about how hydrologic variability influences various ecological processes in streams. Copyright 2005 by the American Geophysical Union.

  5. Addendum to the Closure Report for Corrective Action Unit 339: Area 12 Fleet Operations Steam Cleaning Discharge Area, Nevada Test Site, Revision 0

    SciTech Connect

    Grant Evenson

    2009-05-01

    This document constitutes an addendum to the Closure Report for CAU 339: Area 12 Fleet Operations Steam Cleaning Discharge Area Nevada Test Site, December 1997 as described in the document Supplemental Investigation Report for FFACO Use Restrictions, Nevada Test Site, Nevada (SIR) dated November 2008. The SIR document was approved by NDEP on December 5, 2008. The approval of the SIR document constituted approval of each of the recommended UR removals. In conformance with the SIR document, this addendum consists of: • This page that refers the reader to the SIR document for additional information • The cover, title, and signature pages of the SIR document • The NDEP approval letter • The corresponding section of the SIR document This addendum provides the documentation justifying the cancellation of the UR for CAS 12-19-01, A12 Fleet Ops Steam Cleaning Efflu. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was reevaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above the risk-based FALs. Requirements for inspecting and maintaining this UR will be canceled, and the postings and signage at this site will be removed. Fencing and posting may be present at this site that are unrelated to the

  6. Numerical simulation of a direct current glow discharge in atmospheric pressure helium

    NASA Astrophysics Data System (ADS)

    Yin, Zeng-Qian; Wang, Yan; Zhang, Pan-Pan; Zhang, Qi; Li, Xue-Chen

    2016-12-01

    Characteristics of a direct current (DC) discharge in atmospheric pressure helium are numerically investigated based on a one-dimensional fluid model. The results indicate that the discharge does not reach its steady state till it takes a period of time. Moreover, the required time increases and the current density of the steady state decreases with increasing the gap width. Through analyzing the spatial distributions of the electron density, the ion density and the electric field at different discharge moments, it is found that the DC discharge starts with a Townsend regime, then transits to a glow regime. In addition, the discharge operates in a normal glow mode or an abnormal glow one under different parameters, such as the gap width, the ballast resistors, and the secondary electron emission coefficients, judged by its voltage-current characteristics. Project supported by the National Natural Science Foundation of China (Grant Nos. 11575050 and 10805013), the Midwest Universities Comprehensive Strength Promotion Project, the Natural Science Foundation of Hebei Province, China (Grant Nos. A2016201042 and A2015201092), and the Research Foundation of Education Bureau of Hebei Province, China (Grant No. LJRC011).

  7. Hysterectomy - vaginal - discharge

    MedlinePlus

    Vaginal hysterectomy - discharge; Laparoscopically assisted vaginal hysterectomy - discharge; LAVH - discharge ... you were in the hospital, you had a vaginal hysterectomy. Your surgeon made a cut in your ...

  8. Tubal ligation - discharge

    MedlinePlus

    ... discharge; Tube tying - discharge; Tying the tubes - discharge; Contraception - tubal ... chap 23. Jensen JT, Mishell DR. Family planning: contraception, sterilization, and pregnancy termination. In: Lentz GM, Lobo ...

  9. The effect of the operation modes of a gas discharge low-pressure amalgam lamp on the intensity of generation of 185 nm UV vacuum radiation

    SciTech Connect

    Vasilyak, L. M.; Drozdov, L. A. Kostyuchenko, S. V.; Sokolov, D. V.; Kudryavtsev, N. N.; Sobur, D. A.

    2011-12-15

    The effect of the discharge current, mercury vapor pressure, and the inert gas pressure on the intensity and efficiency of the 185 nm line generation are considered. The spectra of the UV radiation (vacuum ultraviolet) transmission by protective coatings from the oxides of rare earth metals and aluminum are investigated.

  10. Influence of Operating Parameters on Surface Properties of RF Glow Discharge Oxygen Plasma Treated TiO2/PET Film for Biomedical Application

    EPA Science Inventory

    Thin transparent titania (TiO2) films were coated on the surface of flexible poly (ethylene terephthalate) (PET) surface using standard sol gel techniques. The TiO2/PET thin film surfaces were further modified by exposing the films to a RF glow discharge oxygen plasma. The exposu...

  11. Gastroesophageal reflux - discharge

    MedlinePlus

    Peptic esophagitis - discharge; Reflux esophagitis - discharge; GERD - discharge; Heartburn - chronic - discharge ... You have gastroesophageal reflux disease (GERD). This is a condition in which food or liquid travels backwards from the stomach to the esophagus ( ...

  12. Ventriculoperitoneal shunt - discharge

    MedlinePlus

    ... ventriculoperitoneal - discharge; VP shunt - discharge; Shunt revision - discharge; Hydrocephalus shunt placement - discharge ... Your child has hydrocephalus and needed a shunt placed to drain excess fluid and relieve pressure in the brain. This buildup of brain ...

  13. Refractive corneal surgery - discharge

    MedlinePlus

    Nearsightedness surgery - discharge; Refractive surgery - discharge; LASIK - discharge; PRK - discharge ... You had refractive corneal surgery to help improve your vision. This surgery uses a laser to reshape your cornea. It corrects mild-to-moderate nearsightedness, ...

  14. Energetic Ion Beam Production by a Low-Pressure Plasma Focus Discharge

    SciTech Connect

    Lim, L. K.; Yap, S. L.; Wong, C. S.

    2011-03-30

    Energetic ion beam emissions in a 3 kJ Mather type plasma focus operating at low-pressure regime are investigated. Deuterium gas is used and the discharge is operated in a low-pressure regime of below 1 mbar. Formation of the current sheath during the breakdown phase at the back wall is assisted by a set delayed trigger pulse. Energetic and intense ion beams with good reproducibility have been obtained for the operating pressure ranging from 0.05 mbar to 0.5 mbar. Deuteron beam is determined by time resolved measurement by making use of three biased ion collectors placed at the end on direction. The average energies of deuteron beams are resolved by using time-of flight method. Correlation between the ion emissions and the current sheath dynamics is also discussed.

  15. Stage-Discharge Relations for the Colorado River in Glen, Marble, and Grand Canyons, Arizona, 1990-2005

    USGS Publications Warehouse

    Hazel, Joseph E.; Kaplinski, Matt; Parnell, Rod; Kohl, Keith; Topping, David J.

    2007-01-01

    This report presents stage-discharge relations for 47 discrete locations along the Colorado River, downstream from Glen Canyon Dam. Predicting the river stage that results from changes in flow regime is important for many studies investigating the effects of dam operations on resources in and along the Colorado River. The empirically based stage-discharge relations were developed from water-surface elevation data surveyed at known discharges at all 47 locations. The rating curves accurately predict stage at each location for discharges between 141 cubic meters per second and 1,274 cubic meters per second. The coefficient of determination (R2) of the fit to the data ranged from 0.993 to 1.00. Given the various contributing errors to the method, a conservative error estimate of ?0.05 m was assigned to the rating curves.

  16. A comparative study of changes operated by sympathetic nervous system activation on spindle afferent discharge and on tonic vibration reflex in rabbit jaw muscles.

    PubMed

    Passatore, M; Deriu, F; Grassi, C; Roatta, S

    1996-03-07

    The effect of sympathetic activation on the spindle afferent response to vibratory stimuli eliciting the tonic vibration reflex in jaw closing muscles was studied in precollicularly decerebrate rabbits. Stimulation of the cervical sympathetic trunk, at frequencies within the physiologic range, consistently induced a decrease in spindle response to muscle vibration, which was often preceded by a transient enhancement. Spindle discharge was usually correlated with the EMG activity in the masseter muscle and the tension reflexly developed by jaw muscles. The changes in spindle response to vibration were superimposed on variations of the basal discharge which exhibited different patterns in the studied units, increases in the firing rate being more frequently observed. These effects were mimicked by close arterial injection of the selective alpha 1-adrenoceptor agonist phenylephrine. Data presented here suggest that sympathetically-induced modifications of the tonic vibration reflex are due to changes exerted on muscle spindle afferent information.

  17. Discharge Asymmetry in Delta Bifurcations

    NASA Astrophysics Data System (ADS)

    Salter, G.; Paola, C.; Voller, V. R.

    2015-12-01

    Distributary networks are formed by channels which bifurcate downstream in a river delta. Sediment and water fluxes are often split unequally in delta bifurcations. Understanding flux asymmetry in distributary networks is important for predicting how a delta will respond to sea-level rise. We present results of a quasi-1D model of a delta bifurcation. Consistent with previous results, in the absence of deposition, stable bifurcations may be either symmetric or asymmetric, depending on flow conditions. However, in a depositional setting, a stable asymmetric flow partitioning is no longer possible, as the dominant branch becomes less and less steep relative to the other branch. This feedback eventually causes the second branch to become favored. For the depositional case, we identify three regimes of bifurcation behavior: 1) stable symmetric bifurcation, 2) "soft" avulsions where the dominant branch switches without complete abandonment of the previous channel, and 3) complete avulsions where one branch is completely abandoned. In each case, the bifurcation is symmetric in the long-term average, but the latter two allow for short-term asymmetry. We find that keeping upstream sediment and water discharges fixed, as downstream channel length increases the regime shifts from symmetric to soft avulsions to complete avulsions. In the two avulsion regimes we examine the effect of upstream sediment and water discharges and downstream channel length on avulsion period and maximum discharge ratio. Finally, we compare numerical modeling results to a fixed-wall bifurcation experiment. As in the numerical model, the presence or absence of a downstream sink exerts a strong control on system behavior. If a sink is present, a bifurcation may be asymmetric indefinitely. Conversely, without a sink the system is depositional, and the feedback between sediment discharge asymmetry and slope causes the bifurcation to remain symmetric in the long-term average.

  18. Augment railgun and sequential discharge

    NASA Astrophysics Data System (ADS)

    Kobayashi, K.

    1993-01-01

    Proprietary R&D efforts toward the creation of tactical weapon systems-applicable railguns are presented. Attention is given to measures taken for projectile velocity maximization and sequential-discharge operation, and to an augmenting railgun which has demonstrated a 66-percent efficiency improvement over the two-rail baseline railgun system. This device is characterized by strong interaction between capacitor bank submodules during sequential discharge.

  19. Operations

    ERIC Educational Resources Information Center

    Wilkins, Jesse L. M.; Norton, Anderson; Boyce, Steven J.

    2013-01-01

    Previous research has documented schemes and operations that undergird students' understanding of fractions. This prior research was based, in large part, on small-group teaching experiments. However, written assessments are needed in order for teachers and researchers to assess students' ways of operating on a whole-class scale. In this study,…

  20. Regime Shifts in the Anthropocene: Drivers, Risks, and Resilience

    PubMed Central

    Rocha, Juan Carlos; Peterson, Garry D.; Biggs, Reinette

    2015-01-01

    Many ecosystems can experience regime shifts: surprising, large and persistent changes in the function and structure of ecosystems. Assessing whether continued global change will lead to further regime shifts, or has the potential to trigger cascading regime shifts has been a central question in global change policy. Addressing this issue has, however, been hampered by the focus of regime shift research on specific cases and types of regime shifts. To systematically assess the global risk of regime shifts we conducted a comparative analysis of 25 generic types of regime shifts across marine, terrestrial and polar systems; identifying their drivers, and impacts on ecosystem services. Our results show that the drivers of regime shifts are diverse and co-occur strongly, which suggests that continued global change can be expected to synchronously increase the risk of multiple regime shifts. Furthermore, many regime shift drivers are related to climate change and food production, whose links to the continued expansion of human activities makes them difficult to limit. Because many regime shifts can amplify the drivers of other regime shifts, continued global change can also be expected to increase the risk of cascading regime shifts. Nevertheless, the variety of scales at which regime shift drivers operate provides opportunities for reducing the risk of many types of regime shifts by addressing local or regional drivers, even in the absence of rapid reduction of global drivers. PMID:26267896

  1. Regime shifts in the anthropocene: drivers, risks, and resilience.

    PubMed

    Rocha, Juan Carlos; Peterson, Garry D; Biggs, Reinette

    2015-01-01

    Many ecosystems can experience regime shifts: surprising, large and persistent changes in the function and structure of ecosystems. Assessing whether continued global change will lead to further regime shifts, or has the potential to trigger cascading regime shifts has been a central question in global change policy. Addressing this issue has, however, been hampered by the focus of regime shift research on specific cases and types of regime shifts. To systematically assess the global risk of regime shifts we conducted a comparative analysis of 25 generic types of regime shifts across marine, terrestrial and polar systems; identifying their drivers, and impacts on ecosystem services. Our results show that the drivers of regime shifts are diverse and co-occur strongly, which suggests that continued global change can be expected to synchronously increase the risk of multiple regime shifts. Furthermore, many regime shift drivers are related to climate change and food production, whose links to the continued expansion of human activities makes them difficult to limit. Because many regime shifts can amplify the drivers of other regime shifts, continued global change can also be expected to increase the risk of cascading regime shifts. Nevertheless, the variety of scales at which regime shift drivers operate provides opportunities for reducing the risk of many types of regime shifts by addressing local or regional drivers, even in the absence of rapid reduction of global drivers.

  2. Effect of gas heating on the generation of an ultrashort avalanche electron beam in the pulse-periodic regime

    NASA Astrophysics Data System (ADS)

    Baksht, E. Kh.; Burachenko, A. G.; Lomaev, M. I.; Sorokin, D. A.; Tarasenko, V. F.

    2015-07-01

    The generation of an ultrashort avalanche electron beam (UAEB) in nitrogen in the pulse-periodic regime is investigated. The gas temperature in the discharge gap of the atmospheric-pressure nitrogen is measured from the intensity distribution of unresolved rotational transitions ( C 3Π u , v' = 0) → ( B 3Π g , v″ = 0) in the nitrogen molecule for an excitation pulse repetition rate of 2 kHz. It is shown that an increase in the UAEB current amplitude in the pulse-periodic regime is due to gas heating by a series of previous pulses, which leads to an increase in the reduced electric field strength as a result of a decrease in the gas density in the zone of the discharge formation. It is found that in the pulse-periodic regime and the formation of the diffuse discharge, the number of electrons in the beam increases by several times for a nitrogen pressure of 9 × 103 Pa. The dependences of the number of electrons in the UAEB on the time of operation of the generator are considered.

  3. Impact of air conditioning system operation on increasing gases emissions from automobile

    NASA Astrophysics Data System (ADS)

    Burciu, S. M.; Coman, G.

    2016-08-01

    The paper presents a study concerning the influence of air conditioning system operation on the increase of gases emissions from cars. The study focuses on urban operating regimes of the automobile, regimes when the engines have low loads or are operating at idling. Are presented graphically the variations of pollution emissions (CO, CO2, HC) depending of engine speed and the load on air conditioning system. Additionally are presented, injection duration, throttle position, the mechanical power required by the compressor of air conditioning system and the refrigerant pressure variation on the discharge path, according to the stage of charging of the air conditioning system.

  4. In situ CF3 Detection in Low Pressure Inductive Discharges by Fourier Transform Infrared Spectroscopy

    NASA Technical Reports Server (NTRS)

    Kim, J. S.; Cappelli, M. A.; Sharma, S. P.; Arnold, J. O. (Technical Monitor)

    1998-01-01

    The detection of CF(x) (x=1-3) radicals in low pressure discharges using source gases such as CF4 and CHF3 is of importance to the understanding of their chemical structure and relevance in plasma based etching processes. These radicals are known to contribute to the formation of fluorocarbon polymer films, which affect the selectivity and anisotropy of etching. In this study, we present preliminary results of the quantitative measurement of trifluoromethyl radicals, CF3, in low pressure discharges. The discharge studied here is an inductively (transformer) coupled plasma (ICP) source in the GEC reference cell, operating on pure CF4 at pressures ranging from 10 - 100 mTorr, This plasma source generates higher electron number densities at lower operating pressures than obtainable with the parallel-plate capacitively coupled version of the GEC reference cell. Also, this expanded operating regime is more relevant to new generations of industrial plasma reactors being used by the microelectronics industry. Fourier transform infrared (FTIR) spectroscopy is employed to observe the absorption band of CF3 radicals in the electronic ground state X2Al in the region of 1233-1270/cm. The spectrometer is equipped with a high sensitivity HgCdTe (MCT) detector and has a fixed resolution of 0.125/cm. The CF3 concentrations are measured for a range of operating pressures and discharge power levels.

  5. Prediction of nested complementary pattern in argon dielectric-barrier discharge at atmospheric pressure

    PubMed Central

    Jiang, Weiman; Li, Jing; Tang, Jie; Wang, Yishan; Zhao, Wei; Duan, Yixiang

    2015-01-01

    A two-dimensional self-consistent fluid model was employed to investigate the spatiotemporal nonlinear behavior in an argon glow-like/Townsend-like dielectric-barrier discharge (DBD) at atmospheric pressure. The discharge is characterized by a major current pulse with a residual one ahead per half cycle of the external voltage. The two current pulses are operated in glow mode, but with Townsend mode between them. Contrasting spatial discharge structures are complementarily presented not only at two current pulses in the same half cycle but also during the discharge in the two adjacent-half cycles, resulting in the formation of a unique nested complementary pattern each cycle. This peculiar behavior mainly lies in the fact that sufficient charged particles are trapped in the gas gap due to the last discharge and able to dominate the subsequent discharge through the “spatial memory effect”. The charge transport regime reveals that this nested complementary pattern is presented only in a limited range of driving frequency. PMID:26552714

  6. Optimum operating regimes of common paramagnetic refrigerants

    NASA Astrophysics Data System (ADS)

    Wikus, Patrick; Burghart, Gerhard; Figueroa-Feliciano, Enectalí

    2011-09-01

    Adiabatic Demagnetization Refrigerators (ADRs) are commonly used in cryogenic laboratories to achieve subkelvin temperatures. ADRs are also the technology of choice for several space borne instruments which make use of cryogenic microcalorimeters or bolometers [1-4]. For these applications, refrigerants with high ratios of cooling capacity to volume, or cooling capacity to mass are usually required. In this manuscript, two charts for the simple selection of the most suitable of several common refrigerants (CAA, CMN, CPA, DGG, FAA, GGG, GLF and MAS) are presented. These graphs are valid for single stage cycles. The selection of the refrigerants is uniquely dependent on the starting conditions of the refrigeration cycle (temperature and magnetic field density) and the desired final temperature. Only thermodynamic properties of the refrigerants have been taken into account, and other important factors such as availability and manufacturability have not been considered.

  7. Pulsed COIL initiated by discharge

    NASA Astrophysics Data System (ADS)

    Yuryshev, Nikolai N.

    2004-06-01

    Pulsed mode makes COIL possible to produce pulses which power can significantly exceed that of CW COIL mode at the same flowrate of chemicals. Such a mode can find application in material treatment, in drilling for oil wells, as an optical locator, in laser frequency conversion via non-linear processes, in laser propulsion, etc. The method of volume generation of iodine atoms was shown to be the most effective one in generation of high power pulses. The base of method is substitution of molecular iodine in operation mixture for iodide which is stable in the mixture with singlet oxygen, and subsequent forced dissociation of iodide. In this approach the advantage of direct I-atom injection in laser active medium is demonstrated. The comparison of experimental results obtained with different sources used for iodide dissociation shows the electric discharge provides significantly higher electrical laser efficiency in comparison with photolysis initiation. At the same time, the specific energy of the electric discharge initiated COIL is at disadvantage in relation with that obtained with photolysis initiation. This fact is a result of active medium temperature increase due to insufficient initiation selectivity of electric discharge. Both longitudinal and transverse electric discharges were investigated as possible sources for laser initiation. The transverse discharge is more promising for increased operation pressure of active medium. The operation pressure is limited by dark reaction of iodide with singlet delta oxygen. The repetitively pulsed operation with repetition rate of up to 75 Hz of pulsed COIL is demonstrated.

  8. Climatic and landscape controls on effective discharge

    NASA Astrophysics Data System (ADS)

    Basso, S.; Frascati, A.; Marani, M.; Schirmer, M.; Botter, G.

    2015-10-01

    The effective discharge constitutes a key concept in river science and engineering. Notwithstanding many years of studies, a full understanding of the effective discharge determinants is still challenged by the variety of values identified for different river catchments. The present paper relates the observed diversity of effective discharge to the underlying heterogeneity of flow regimes. An analytic framework is proposed, which links the effective ratio (i.e., the ratio between effective discharge and mean streamflow) to the empirical exponent of the sediment rating curve and to the streamflow variability, resulting from climatic and landscape drivers. The analytic formulation predicts patterns of effective ratio versus streamflow variability observed in a set of catchments of the continental United States and helps in disentangling the major climatic and landscape drivers of sediment transport in rivers. The findings highlight larger effective ratios of erratic hydrologic regimes (characterized by high flow variability) compared to those exhibited by persistent regimes, which are attributable to intrinsically different streamflow dynamics. The framework provides support for the estimate of effective discharge in rivers belonging to diverse climatic areas.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. 40 CFR 1700.7 - No-discharge zones.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES UNIFORM NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES Effect on States No-Discharge Zones § 1700.7 No-discharge zones. For this part... the normal operation of Armed Forces vessels, whether treated or not, are prohibited. A...

  11. 40 CFR 1700.7 - No-discharge zones.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES UNIFORM NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES Effect on States No-Discharge Zones § 1700.7 No-discharge zones. For this part... the normal operation of Armed Forces vessels, whether treated or not, are prohibited. A...

  12. 40 CFR 1700.7 - No-discharge zones.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES UNIFORM NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES Effect on States No-Discharge Zones § 1700.7 No-discharge zones. For this part... the normal operation of Armed Forces vessels, whether treated or not, are prohibited. A...

  13. 40 CFR 1700.7 - No-discharge zones.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES UNIFORM NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES Effect on States No-Discharge Zones § 1700.7 No-discharge zones. For this part... the normal operation of Armed Forces vessels, whether treated or not, are prohibited. A...

  14. 40 CFR 1700.7 - No-discharge zones.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES UNIFORM NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES Effect on States No-Discharge Zones § 1700.7 No-discharge zones. For this part... the normal operation of Armed Forces vessels, whether treated or not, are prohibited. A...

  15. Champagne experiences various rhythmical bubbling regimes in a flute.

    PubMed

    Liger-Belair, Gérard; Tufaile, Alberto; Jeandet, Philippe; Sartorelli, José-Carlos

    2006-09-20

    Bubble trains are seen rising gracefully from a few points on the glass wall (called nucleation sites) whenever champagne is poured into a glass. As time passes during the gas-discharging process, the careful observation of some given bubble columns reveals that the interbubble distance may change suddenly, thus revealing different rhythmical bubbling regimes. Here, it is reported that the transitions between the different bubbling regimes of some nucleation sites during gas discharging is a process which may be ruled by a strong interaction between tiny gas pockets trapped inside the nucleation site and/or also by an interaction between the tiny bubbles just blown from the nucleation site.

  16. Tennis elbow surgery - discharge

    MedlinePlus

    ... epicondylitis surgery - discharge; Lateral tendinosis surgery - discharge; Lateral tennis elbow surgery - discharge ... long as you are told. This helps ensure tennis elbow will not return. You may be prescribed a ...

  17. Eye muscle repair - discharge

    MedlinePlus

    ... Lazy eye repair - discharge; Strabismus repair - discharge; Extraocular muscle surgery - discharge ... You or your child had eye muscle repair surgery to correct eye muscle ... term for crossed eyes is strabismus. Children most often ...

  18. Asthma - child - discharge

    MedlinePlus

    Pediatric asthma - discharge; Wheezing - discharge; Reactive airway disease - discharge ... Your child has asthma , which causes the airways of the lungs to swell and narrow. In the hospital, the doctors and nurses helped ...

  19. Gastric bypass surgery - discharge

    MedlinePlus

    Bariatric surgery - gastric bypass - discharge; Roux-en-Y gastric bypass - discharge; Gastric bypass - Roux-en-Y - discharge; Obesity ... Gloy VL, Briel M, Bhatt DL, et al. Bariatric surgery versus non-surgical treatment for obesity: a systematic ...

  20. Influence of operating parameters on surface properties of RF glow discharge oxygen plasma treated TiO₂/PET film for biomedical application.

    PubMed

    Pandiyaraj, K Navaneetha; Deshmukh, R R; Mahendiran, R; Su, Pi-G; Yassitepe, Emre; Shah, Ismat; Perni, Stefano; Prokopovich, Polina; Nadagouda, Mallikarjuna N

    2014-03-01

    In this paper, a thin transparent titania (TiO2) film was coated on the surface of flexible poly(ethylene terephthalate) (PET) film using the sol-gel method. The surface properties of the obtained TiO2/PET film were further improved by RF glow discharge oxygen plasma as a function of exposure time and discharge power. The changes in hydrophilicity of TiO2/PET films were analyzed by contact angle measurements and surface energy. The influence of plasma on the surface of the TiO2/PET films was analyzed by atomic force microscopy (AFM) as well as the change in chemical state and composition that were investigated by X-ray photo electron spectroscopy (XPS). The cytotoxicity of the TiO2/PET films was analyzed using human osteoblast cells and the bacterial eradication behaviors of TiO2/PET films were also evaluated against Staphylococcus bacteria. It was found that the surface roughness and incorporation of oxygen containing polar functional groups of the plasma treated TiO2/PET films increased substantially as compared to the untreated one. Moreover the increased concentration of Ti(3+) on the surface of plasma treated TiO2/PET films was due to the transformation of chemical states (Ti(4+)→Ti(3+)). These morphological and chemical changes are responsible for enhanced hydrophilicity of the TiO2/PET films. Furthermore, the plasma treated TiO2/PET film exhibited no citotoxicity against osteoblast cells and antibacterial activity against Staphylococcus bacteria which can find application in manufacturing of biomedical devices.

  1. Fish Hold Effluent and Fish Hold Cleaning Wastewater Discharge

    DTIC Science & Technology

    2011-11-01

    commercial fishing vessels, and fish hold cleaning discharge samples from 9 vessels for their Study of Discharges Incidental to Normal Operation of...operate in US waters, representing the largest category of vessels in the Report to Congress: Study of Discharges Incidental to Normal Operation of...feet in length that fish the Bering Sea and the Gulf of Alaska for king crab (USEPA, 2010). During the 2010 Study of vessel discharges, EPA observed

  2. Surface water discharges from onshore stripper wells.

    SciTech Connect

    Veil, J. A.

    1998-01-16

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

  3. Prostate brachytherapy - discharge

    MedlinePlus

    Implant therapy - prostate cancer - discharge; Radioactive seed placement - discharge ... You had a procedure called brachytherapy to treat prostate cancer. Your treatment lasted 30 minutes or more, depending ...

  4. ACL reconstruction - discharge

    MedlinePlus

    Anterior cruciate ligament reconstruction - discharge; ACL reconstruction - discharge ... had surgery to reconstruct your anterior cruciate ligament (ACL). The surgeon drilled holes in the bones of ...

  5. Arctic circulation regimes.

    PubMed

    Proshutinsky, Andrey; Dukhovskoy, Dmitry; Timmermans, Mary-Louise; Krishfield, Richard; Bamber, Jonathan L

    2015-10-13

    Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic and anticyclonic alternating at 5 to 7 year intervals. During cyclonic regimes, low sea-level atmospheric pressure (SLP) dominated over the Arctic Ocean driving sea ice and the upper ocean counterclockwise; the Arctic atmosphere was relatively warm and humid, and freshwater flux from the Arctic Ocean towards the subarctic seas was intensified. By contrast, during anticylonic circulation regimes, high SLP dominated driving sea ice and the upper ocean clockwise. Meanwhile, the atmosphere was cold and dry and the freshwater flux from the Arctic to the subarctic seas was reduced. Since 1997, however, the Arctic system has been under the influence of an anticyclonic circulation regime (17 years) with a set of environmental parameters that are atypical for this regime. We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from the Arctic Ocean and Greenland impact environmental conditions and interrupt their decadal variability.

  6. Arctic circulation regimes

    PubMed Central

    Proshutinsky, Andrey; Dukhovskoy, Dmitry; Timmermans, Mary-Louise; Krishfield, Richard; Bamber, Jonathan L.

    2015-01-01

    Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic and anticyclonic alternating at 5 to 7 year intervals. During cyclonic regimes, low sea-level atmospheric pressure (SLP) dominated over the Arctic Ocean driving sea ice and the upper ocean counterclockwise; the Arctic atmosphere was relatively warm and humid, and freshwater flux from the Arctic Ocean towards the subarctic seas was intensified. By contrast, during anticylonic circulation regimes, high SLP dominated driving sea ice and the upper ocean clockwise. Meanwhile, the atmosphere was cold and dry and the freshwater flux from the Arctic to the subarctic seas was reduced. Since 1997, however, the Arctic system has been under the influence of an anticyclonic circulation regime (17 years) with a set of environmental parameters that are atypical for this regime. We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from the Arctic Ocean and Greenland impact environmental conditions and interrupt their decadal variability. PMID:26347536

  7. Sediment regime constraints on river restoration - An example from the lower missouri river

    USGS Publications Warehouse

    Jacobson, R.B.; Blevins, D.W.; Bitner, C.J.

    2009-01-01

    Dammed rivers are subject to changes in their flow, water-quality, and sediment regimes. Each of these changes may contribute to diminished aquatic habitat quality and quantity. Of the three factors, an altered sediment regime is a particularly unyielding challenge on many dammed rivers. The magnitude of the challenge is illustrated on the Lower Missouri River, where the largest water storage system in North America has decreased the downriver suspended-sediment load to 0.2%-17% of predamloads. In response to the altered sediment regime, the Lower Missouri River channel has incised as much as 3.5 m just downstream of Gavins Point Dam, although the bed has been stable to slightly aggrading at other locations farther downstream. Effects of channel engineering and commercial dredging are superimposed on the broad-scale adjustments to the altered sediment regime. The altered sediment regime and geomorphic adjustments constrain restoration and management opportunities. Incision and aggradation limit some objectives of flow-regime management: In incising river segments, ecologically desirable reconnection of the floodplain requires discharges that are beyond operational limits, whereas in aggrading river segments, small spring pulses may inundate or saturate low-lying farmlands. Lack of sediment in the incising river segment downstream of Gavins Point Dam also limits sustainable restoration of sand-bar habitat for bird species listed under the Endangered Species Act. Creation of new shallow-water habitat for native fi shes involves taking sediment out of floodplain storage and reintroducing most or all of it to the river, raising concerns about increased sediment, nutrient, and contaminant loads. Calculations indicate that effects of individual restoration projects are small relative to background loads, but cumulative effects may depend on sequence and locations of projects. An understanding of current and historical sediment fl uxes, and how they vary along the river

  8. Simulation and Analysis of the Hybrid Operating Mode in ITER

    SciTech Connect

    Kessel, C.E.; Budny, R.V.; Indireshkumar, K.

    2005-09-22

    The hybrid operating mode in ITER is examined with 0D systems analysis, 1.5D discharge scenario simulations using TSC and TRANSP, and the ideal MHD stability is discussed. The hybrid mode has the potential to provide very long pulses and significant neutron fluence if the physics regime can be produced in ITER. This paper reports progress in establishing the physics basis and engineering limitation for the hybrid mode in ITER.

  9. RF micro-discharge thruster

    NASA Astrophysics Data System (ADS)

    Dunaevsky, Alexander; Fisch, Nathaniel

    2004-11-01

    Propulsion devices for spacecrafts with masses of several tens to one hundred kilograms are in an increasing demand. These devices should provide thrust of a few mN and specific impulse of about 1000 s at the total power consumption of several tens of W. In search of an alternative solution for lower power range, we investigated an rf discharge initiated in a sub-millimeter capillary fed by a gaseous propellant. In such a discharge, it is possible to heat plasma electrons up to temperatures of ˜ 20-30 eV. Steep density drop at the open end of the capillary should be a reason of the formation of a double layer, were the discharge ions are accelerated to energies of ˜5Te. A laboratory prototype demonstrated stable operation at the argon flow rate of 4-10 sccm. The discharge was powered by a 2 MHz rf generator. Power consumption of the discharge was about 16 W. Ionization rate was moderate due to nonoptimal electrode configuration, which resulted in the propellant utilization of 6-11%. Relatively wide plume angle of ˜130 degrees indicates that the acceleration region is placed outside the capillary and has a convex shape. Stability and parameters of the discharge depends on the material of the capillary channel. Among advantages of the rf micro-discharge thruster are simplicity, small size, and absence of cathode-neutralizer. Being optimized, the rf micro-discharge thruster seems very promising propulsion device for sub-mN thrust range.

  10. GAS DISCHARGE DEVICES

    DOEpatents

    Arrol, W.J.; Jefferson, S.

    1957-08-27

    The construction of gas discharge devices where the object is to provide a gas discharge device having a high dark current and stabilized striking voltage is described. The inventors have discovered that the introduction of tritium gas into a discharge device with a subsequent electrical discharge in the device will deposit tritium on the inside of the chamber. The tritium acts to emit beta rays amd is an effective and non-hazardous way of improving the abovementioned discharge tube characteristics

  11. Factors determining discharge destination for patients undergoing total joint arthroplasty.

    PubMed

    Sharareh, Behnam; Le, Natasha B; Hoang, Melinda T; Schwarzkopf, Ran

    2014-07-01

    Discharge destination to skilled nursing facilities (SNF) following total joint arthroplasty (TJA) plays an important role in healthcare costs. The pre-operative, intra-operative, and post-operative factors of 50 consecutive patients discharged to an SNF following TJA were compared to that of 50 consecutive patients discharged to home. Patients discharged to SNFs had slower pre-operative Get Up and Go scores (TGUG), lower pre-operative EQ-5D scores, higher ASA scores, increased hospital length of stay, increased self-reported post-operative pain, and decreased physical therapy achievements. We believe that the results of this study indicate that patients who get discharged to SNFs fit a certain criteria and this may be used to guide post-operative discharge destination during pre-operative planning, which can help lower costs while helping decrease the length of inpatient stay.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  13. Device for generation of pulsed corona discharge

    SciTech Connect

    Gutsol, Alexander F; Fridman, Alexander; Blank, Kenneth; Korobtsev, Sergey; Shiryaevsky, Valery; Medvedev, Dmitry

    2012-05-08

    The invention is a method and system for the generation of high voltage, pulsed, periodic corona discharges capable of being used in the presence of conductive liquid droplets. The method and system can be used, for example, in different devices for cleaning of gaseous or liquid media using pulsed corona discharge. Specially designed electrodes and an inductor increase the efficiency of the system, permit the plasma chemical oxidation of detrimental impurities, and increase the range of stable discharge operations in the presence of droplets of water or other conductive liquids in the discharge chamber.

  14. Angioplasty and stent placement - peripheral arteries - discharge

    MedlinePlus

    Percutaneous transluminal angioplasty - peripheral artery - discharge; PTA - peripheral artery - discharge; Angioplasty - peripheral artery - discharge; Balloon angioplasty - peripheral artery- discharge; PAD - PTA discharge; PVD - PTA discharge

  15. Application of effective discharge analysis to environmental flow decision-making

    USGS Publications Warehouse

    McKay, S. Kyle; Freeman, Mary C.; Covich, A.P.

    2016-01-01

    Well-informed river management decisions rely on an explicit statement of objectives, repeatable analyses, and a transparent system for assessing trade-offs. These components may then be applied to compare alternative operational regimes for water resource infrastructure (e.g., diversions, locks, and dams). Intra- and inter-annual hydrologic variability further complicates these already complex environmental flow decisions. Effective discharge analysis (developed in studies of geomorphology) is a powerful tool for integrating temporal variability of flow magnitude and associated ecological consequences. Here, we adapt the effectiveness framework to include multiple elements of the natural flow regime (i.e., timing, duration, and rate-of-change) as well as two flow variables. We demonstrate this analytical approach using a case study of environmental flow management based on long-term (60 years) daily discharge records in the Middle Oconee River near Athens, GA, USA. Specifically, we apply an existing model for estimating young-of-year fish recruitment based on flow-dependent metrics to an effective discharge analysis that incorporates hydrologic variability and multiple focal taxa. We then compare three alternative methods of environmental flow provision. Percentage-based withdrawal schemes outcompete other environmental flow methods across all levels of water withdrawal and ecological outcomes.

  16. Application of Effective Discharge Analysis to Environmental Flow Decision-Making

    NASA Astrophysics Data System (ADS)

    McKay, S. Kyle; Freeman, Mary C.; Covich, Alan P.

    2016-06-01

    Well-informed river management decisions rely on an explicit statement of objectives, repeatable analyses, and a transparent system for assessing trade-offs. These components may then be applied to compare alternative operational regimes for water resource infrastructure (e.g., diversions, locks, and dams). Intra- and inter-annual hydrologic variability further complicates these already complex environmental flow decisions. Effective discharge analysis (developed in studies of geomorphology) is a powerful tool for integrating temporal variability of flow magnitude and associated ecological consequences. Here, we adapt the effectiveness framework to include multiple elements of the natural flow regime (i.e., timing, duration, and rate-of-change) as well as two flow variables. We demonstrate this analytical approach using a case study of environmental flow management based on long-term (60 years) daily discharge records in the Middle Oconee River near Athens, GA, USA. Specifically, we apply an existing model for estimating young-of-year fish recruitment based on flow-dependent metrics to an effective discharge analysis that incorporates hydrologic variability and multiple focal taxa. We then compare three alternative methods of environmental flow provision. Percentage-based withdrawal schemes outcompete other environmental flow methods across all levels of water withdrawal and ecological outcomes.

  17. O-regime dynamics and modeling in Tore Supra

    NASA Astrophysics Data System (ADS)

    Turco, F.; Giruzzi, G.; Imbeaux, F.; Udintsev, V. S.; Artaud, J. F.; Barana, O.; Dumont, R.; Mazon, D.; Ségui, J.-L.

    2009-06-01

    The regime of nonlinear temperature oscillations (O-regime), characteristic of noninductive discharges on Tore Supra [Équipe Tore Supra, Proceedings of the 12th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Nice, France, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 1, p. 9], is investigated in its triggering and suppressing mechanism. This regime can be described by two nonlinearly coupled equations for the current density j(r ) and the electron temperature Te(r) where the equation coefficients are functions of j and Te themselves. Both the integrated modeling code CRONOS [V. Basiuk et al., Nucl. Fusion 43, 822 (2003)] and a two-patch predator-prey system with diffusion and noise have been used and results have been compared to the experimental observations of the O-regime. A database of discharges is analyzed which features monotonic, flat, and reversed safety factor (q) profiles in order to characterize the action of external actuators on the regime dynamics with the widest generality. Electron cyclotron current drive and neutral beam injections have been used in order to induce localized perturbations in the total current profile j(r ) as well as to change the plasma confinement conditions in the central region. Magnetic shear perturbations and modifications of the heat transport turn out to be the central parameters governing the dynamics of the O-regime.

  18. O-regime dynamics and modeling in Tore Supra

    SciTech Connect

    Turco, F.; Giruzzi, G.; Imbeaux, F.; Udintsev, V. S.; Artaud, J. F.; Barana, O.; Dumont, R.; Mazon, D.; Segui, J.-L.

    2009-06-15

    The regime of nonlinear temperature oscillations (O-regime), characteristic of noninductive discharges on Tore Supra [Equipe Tore Supra, Proceedings of the 12th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Nice, France, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 1, p. 9], is investigated in its triggering and suppressing mechanism. This regime can be described by two nonlinearly coupled equations for the current density j(r) and the electron temperature T{sub e}(r) where the equation coefficients are functions of j and T{sub e} themselves. Both the integrated modeling code CRONOS[V. Basiuk et al., Nucl. Fusion 43, 822 (2003)] and a two-patch predator-prey system with diffusion and noise have been used and results have been compared to the experimental observations of the O-regime. A database of discharges is analyzed which features monotonic, flat, and reversed safety factor (q) profiles in order to characterize the action of external actuators on the regime dynamics with the widest generality. Electron cyclotron current drive and neutral beam injections have been used in order to induce localized perturbations in the total current profile j(r) as well as to change the plasma confinement conditions in the central region. Magnetic shear perturbations and modifications of the heat transport turn out to be the central parameters governing the dynamics of the O-regime.

  19. Deep discharge reconditioning: Pros and cons

    NASA Technical Reports Server (NTRS)

    Scott, W. R.

    1983-01-01

    Deep-discharge reconditioning (DDR) can be of great benefit to battery performance, especially in geosynchronous orbit, if performed properly and regularly, and can be essential to operation of batteries at the high depths of discharge (DOD) required to minimize weight. The procedure should be tailored to fit the nature of the degradation occuring during regular cycling. DDR is not without its drawbacks, however, and these differ depending on the normal DOD to be sustained and/or whether the discharge is done at the battery or the cell level. Battery-level discharge carries the minimum weight penalty but raises questions of the effects of low-rate cell reversal that as yet have no firm answers. Cell level discharge avoids cell reversal but carries significant penalties of weight and complexity. Thus no universal procedure or method of implementation of deep-discharge reconditioning is now available and thus the various approaches must be evaluated for each application.

  20. Discharge coefficient correlations for circular-arc venturi flowmeters at critical /sonic/ flow

    NASA Technical Reports Server (NTRS)

    Arnberg, B. T.; Britton, C. L.; Seidl, W. F.

    1973-01-01

    Experimental data are analyzed to support theoretical predictions for discharge coefficients in circular-arc venturi flow meters operating in the critical sonic flow regime at throat Reynolds numbers above 150 thousand. The data tend to verify the predicted 0.25% decrease in the discharge coefficient during transition from a laminar to turbulent boundary layer. Four different test gases and three flow measurement facilities were used in the experiments with 17 venturis with throat sizes from 0.15 to 1.37 in. and Beta ratios ranging from 0.014 to 0.25. Recommendations are given as to how the effectiveness of future studies in the field could be improved.

  1. State Waste Discharge Permit application, 183-N Backwash Discharge Pond

    SciTech Connect

    Not Available

    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.

  2. Atmospheric sampling glow discharge ionization source

    DOEpatents

    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.

  3. Performance of a novel baffled osmotic membrane bioreactor-microfiltration hybrid system under continuous operation for simultaneous nutrient removal and mitigation of brine discharge.

    PubMed

    Pathak, Nirenkumar; Chekli, Laura; Wang, Jin; Kim, Youngjin; Phuntsho, Sherub; Li, Sheng; Ghaffour, Noreddine; Leiknes, TorOve; Shon, Hokyong

    2017-03-14

    The present study investigated the performance of an integrated osmotic and microfiltration membrane bioreactor system for wastewater treatment employing baffles in the reactor. Thus, this reactor design enables both aerobic and anoxic processes in an attempt to reduce the process footprint and energy costs associated with continuous aeration. The process performance was evaluated in terms of water flux, salinity build up in the bioreactor, organic and nutrient removal and microbial activity using synthetic reverse osmosis (RO) brine as draw solution (DS). The incorporation of MF membrane was effective in maintaining a reasonable salinity level (612-1434mg/L) in the reactor which resulted in a much lower flux decline (i.e. 11.48-6.98LMH) as compared to previous studies. The stable operation of the osmotic membrane bioreactor-forward osmosis (OMBR-FO) process resulted in an effective removal of both organic matter (97.84%) and nutrient (phosphate 87.36% and total nitrogen 94.28%), respectively.

  4. Assessment, validation and intercomparison of operational models for predicting tritium migration from routine discharges of nuclear power plants: the case of Loire River.

    PubMed

    Goutal, Nicole; Luck, Marilyne; Boyer, Patrick; Monte, Luigi; Siclet, Françoise; Angeli, Giacomo

    2008-02-01

    During last decades, a number of projects have been launched to validate models for predicting the behaviour of radioactive substances in the environment. The project of the "Aquatic" working group of the project EMRAS (Environmental Modelling for Radiation Safety) organised by the International Atomic Energy Agency (IAEA) was based on the validation and assessment of models for predicting the behaviour of radionuclides in the aquatic ecosystems. The present paper describes a blind test of models aimed at assessing the dispersion of tritium releases in the Loire River (France), on a large domain ( approximately 350km) and on a period of six months, by comparing the results obtained by operational-to-experimental values of tritium concentration at Angers, a city along the Loire River. The common conclusion is that the models used by the different participants namely 1D models and models based on a schematic hydraulic (box models) are reliable tools for tritium transport modelling. Nevertheless, the importance of proper and detailed hydrological data for the appropriate prediction of pollutant migration in water is demonstrated by the example provided during this study.

  5. Vessel Sewage Discharges

    EPA Pesticide Factsheets

    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.

  6. Nipple Discharge: A Sign of Breast Cancer?

    PubMed Central

    Richards, T; Hunt, A; Courtney, S; Umeh, H

    2007-01-01

    INTRODUCTION Nipple discharge is regarded a sign of breast cancer. Type of discharge and cytology are unreliable for diagnosis. Most malignant cases have a detectable breast mass. The aim of this study was to assess the association between nipple discharge and breast cancer. PATIENTS AND METHODS Patients who underwent operation for nipple discharge at a district general hospital (population 460,000) over a 3-year period were included. All had normal clinical, radiological and cytological examination. Operation and histopathology reports were reviewed. RESULTS Eighty-six patients underwent operation for nipple discharge. Median age was 54 years (range, 32–84 years). Analysis of nipple discharge revealed red blood cells (RBCs) in 35 patients (40%). At operation, 81 patients underwent radical sub-areola duct excision (Hadfield's procedure) and five microdochectomy. Histopathology reported duct ectasia in 59 patients and benign ductal papilloma in 25. Two patients had occult malignancy – DCIS (1) and LCIS (1). No invasive cancer was found. CONCLUSIONS Nipple discharge alone is not usually a sign of breast cancer. Occult malignancy is rare. A period of ‘watchful waiting’ may prevent patients undergoing unnecessary surgery. PMID:17346403

  7. Plasma assisted ignition with nanosecond surface dielectric barrier discharge. Two modes of nanosecond surface discharge

    NASA Astrophysics Data System (ADS)

    Shcherbanev, Sergey; Popov, Nikolay; Starikovskaia, Svetlana; LPP Team; LIA France-Russia Collaboration

    2016-09-01

    Nanosecond surface dielectric barrier discharge (nSDBD) is an efficient tool for a multi-point plasma-assisted ignition of combustible mixtures at elevated pressures. In combustible mixtures, nSDBD initiates numerous combustion waves propagating from the electrode. This work presents a comparative experimental study of the surface dielectric barrier discharge initiated by high voltage pulses (U =+/-(20-60) kV) of different polarities in air at elevated pressures (P =1 -12 bar). Discharge morphology, deposited energy, and spectroscopy of the discharges are analyzed. Differences between the discharges of the different polarity, as well as the changes in the discharge morphology with changing of a gas mixture composition, are discussed. The initiation of combustion with nSDBD was studied experimentally at high initial pressures up to 6 bar on the example of lean H2/Air. The ignition is initiated with two different discharge modes: streamer and filamentary. The influence of the discharge structure and energy deposition on the ignition is demonstrated. Three regimes of multi-point ignition were observed: ignition with a few kernels, quasi-uniform ignition along the edge of high voltage electrodes and ignition along the plasma channels.

  8. Boundary Effect of Planar Glow Dielectric Barrier Discharge and Its Influence on the Discharge Structure

    NASA Astrophysics Data System (ADS)

    Xu, Shaowei; Li, Lulu; Ouyang, Jiting

    2015-05-01

    The dielectric barrier discharge (DBD) in the glow regime in neon has been investigated by experiment and two-dimensional (2D) fluid modeling. The discharge was carried out in a planar DBD system with segmented-electrodes driven by square-wave voltage. The results show that the glow DBD originates in the center of the electrode and expands outward to the electrode edge during each half cycle of the voltage, forming a radial structure. The discharge decays firstly in the inner area but sustains longer in the edge area, showing a reversed discharge area. The discharge cannot completely cover the entire electrode surface, but remains a border of non- or weak discharge. The fluid modeling shows a similar result in agreement with the experiments. The simulations indicate that the electric field in the edge area is distorted due to the boundary effect so that the electric field and charge distribution are different from that in the inner part. The distorted field reduces the longitudinal component near the edge and causes the local field to be lower than that in the center, and hence makes the discharge behindhand. It also induces a transverse field that makes the discharge extend radially outward to the edge. The boundary effect plays an important role in the glow DBD structure. supported by National Natural Science Foundation of China (No. 11175017)

  9. Pediatric heart surgery - discharge

    MedlinePlus

    ... get enough calories to heal and grow. After heart surgery, most babies and infants (younger than 12 to 15 months) can take ... valve surgery - children - discharge; Heart surgery - pediatric - discharge; Heart transplant - pediatric - discharge ... open heart surgery References Bernstein D. General principles ...

  10. Spine surgery - discharge

    MedlinePlus

    ... symptoms should get better in a few weeks. Recovery after laminectomy and fusion surgery is longer. You will not be able ... discharge; Anterior spinal fusion - discharge; Spine surgery - spinal fusion - discharge Images Spinal surgery -- cervical - series References Agrawal BM, Zeidman SM, Rhines L, ...

  11. Multiscale regime shifts and planetary boundaries.

    PubMed

    Hughes, Terry P; Carpenter, Stephen; Rockström, Johan; Scheffer, Marten; Walker, Brian

    2013-07-01

    Life on Earth has repeatedly displayed abrupt and massive changes in the past, and there is no reason to expect that comparable planetary-scale regime shifts will not continue in the future. Different lines of evidence indicate that regime shifts occur when the climate or biosphere transgresses a tipping point. Whether human activities will trigger such a global event in the near future is uncertain, due to critical knowledge gaps. In particular, we lack understanding of how regime shifts propagate across scales, and whether local or regional tipping points can lead to global transitions. The ongoing disruption of ecosystems and climate, combined with unprecedented breakdown of isolation by human migration and trade, highlights the need to operate within safe planetary boundaries.

  12. Classification of river regimes: A context for hydroecology

    USGS Publications Warehouse

    Osterkamp, W.R.; Friedman, J.M.

    2000-01-01

    Over the past 30 years, ecologists have demostrated the importance of flow and temperature as primary variables in driving running water, riparian and floodplain ecosystems. As it is important to assess the size and timing of discharge variations in relation to those in temperature, a method is proposed that uses multivariate techniques to separately classify annual discharge and temperature regimes according to their 'shape' and 'magnitude', and which then combines the classifications. This paper: (i) describes a generally applicable method; (ii) tests the method by applying it to riparian systems on four British rivers using a 20-year record (1977-97) of flow and air temperature: (iii) proposes a hydroecological interpretation of the classification; (iv) considers the degree to which the methodology might provide information to support the design of ecologically acceptable flow regimes. 'Regimes' are defined for discharge and air temperature using monthly mean data. The results of applying the classification procedure to four British rivers indicates that the 'typical' regimes for each of the four catchments are composite features produced by a small number of clearly defined annual types that reflect interannual variability in hydroclimatological conditions. Annual discharge patterns are dominated by three 'shape' classes (accounting for 94% of the station years: class A, early (November) peak; class B, intermediate (December-January) peak; and class C, late (March) peak) and one 'magnitude' class (70% of the station years fall into class 3, intermediate), with two subordinate 'magnitude' classes: low-flow years (18%) and high flow years (12%). For air temperature, annual patterns are classified evenly into three 'shape' and four 'magnitude' classes. It is argued that this variety of flow-temperature patterns is important for sustaining ecosystem integrity and for establishing benchmark flow regimes and associated frequencies to aid river management. Copyright

  13. Anti-reflux surgery - children - discharge

    MedlinePlus

    Fundoplication - children - discharge; Nissen fundoplication - children - discharge; Belsey (Mark IV) fundoplication - children - discharge; Toupet fundoplication - children - discharge; Thal fundoplication - ...

  14. Nonsputtering impulse magnetron discharge

    SciTech Connect

    Khodachenko, G. V.; Mozgrin, D. V.; Fetisov, I. K.; Stepanova, T. V.

    2012-01-15

    Experiments with quasi-steady high-current discharges in crossed E Multiplication-Sign B fields in various gases (Ar, N{sub 2}, H{sub 2}, and SF{sub 6}) and gas mixtures (Ar/SF{sub 6} and Ar/O{sub 2}) at pressures from 10{sup -3} to 5 Torr in discharge systems with different configurations of electric and magnetic fields revealed a specific type of stable low-voltage discharge that does not transform into an arc. This type of discharge came to be known as a high-current diffuse discharge and, later, a nonsputtering impulse magnetron discharge. This paper presents results from experimental studies of the plasma parameters (the electron temperature, the plasma density, and the temperature of ions and atoms of the plasma-forming gas) of a high-current low-pressure diffuse discharge in crossed E Multiplication-Sign B fields.

  15. 46 CFR 154.1838 - Discharge by gas pressurization.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Discharge by gas pressurization. 154.1838 Section 154... SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Operations § 154.1838 Discharge by gas pressurization. The person in charge of cargo transfer may not authorize cargo discharge...

  16. 46 CFR 154.1838 - Discharge by gas pressurization.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Discharge by gas pressurization. 154.1838 Section 154... SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Operations § 154.1838 Discharge by gas pressurization. The person in charge of cargo transfer may not authorize cargo discharge...

  17. 46 CFR 154.1838 - Discharge by gas pressurization.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Discharge by gas pressurization. 154.1838 Section 154... SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Operations § 154.1838 Discharge by gas pressurization. The person in charge of cargo transfer may not authorize cargo discharge...

  18. Theory of beam plasma discharge

    NASA Technical Reports Server (NTRS)

    Papadopoulos, K.

    1982-01-01

    The general theory of beam plasma discharge (BPD) is discussed in relation to space and laboratory beam injection situations. An important concept introduced is that even when beam plasma instabilities are excited, there are two regime of BPD with radically different observational properties. They are described here as BPD with either classical or anomalous energy depositions. For high pressures or low altitudes, the classical is expected to dominate. For high altitudes and laboratory experiments, where the axial system size is less than lambda sub en, no BPD will be triggered unless the unstable waves are near the ambient plasma frequency and their amplitudes at saturation are large enough to create suprathermal tails by collapsing.

  19. Production of Ar metastables in a dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Mikheyev, Pavel A.; Han, Jiande; Clark, Amanda; Sanderson, Carl; Heaven, Michael C.

    2017-01-01

    The results of experiments with a dielectric barrier discharge (DBD) are presented, where the production of metastable argon atoms was studied. The recently proposed optically pumped all-rare-gas laser (OPRGL) utilizes metastable atoms of heavier rare gases as lasing species. The required number density of metastables for efficient laser operation is 1012÷1013 cm-3 in an atmospheric pressure of He buffer gas. Recent experiments had shown that such densities are easily produced in a nanosecond pulsed discharge, even at pressures larger than atmospheric, but problems appear when one is trying to produce them in a CW regime. The reason for difficulties in the CW production of metastables at an atmospheric pressure seems to be the low value of the E/N parameter (<5-6 Td). In our experiments a 20 KHz DBD in 2-5% Ar mixture with He at an atmospheric pressure was studied. [Ar(1s5)] number density of the order of 1012 cm-3 was readily achieved. Temporal behavior of [Ar(1s5)] throughout the DBD cycle was obtained. The results demonstrate the feasibility of DBDs for OPRGL development.

  20. Stability of atmospheric pressure glow discharges

    NASA Astrophysics Data System (ADS)

    Chirokov, Alexandre V.

    There has been a considerable interest in non-thermal atmospheric pressure discharges over the past decade due to increased number of industrial applications. Although non-thermal atmospheric pressure discharges have been intensively studied for the past century the clear physical picture of these discharges is far from being complete. Spontaneous transition of non-thermal atmospheric pressure discharges to thermal discharge and discharge filamentation are among least understood plasma phenomena. The discharge stability and reliable control of plasma parameters are highly desirable for numerous applications. This study focuses on stability of atmospheric pressure glow discharges with respect to filamentation and arcing. Atmospheric pressure glow discharge (APG) is the newest and the most promising addition to the family of non-thermal atmospheric pressure discharges. However this discharge is very susceptible to thermal instability which causes arcing, loss of uniformity and significant damage to electrodes. Suppression of thermal instability and effective control of discharge parameters is critical for industrial applications. A model was developed to understand transition to arc in atmospheric pressure glow discharges. APG discharges that operate in pure helium and in helium with addition of oxygen and nitrogen were considered in these studies. Simulation results indicate that arcing is the result of sheath breakdown rather than thermal instability. It was shown that although sheath breakdown is always followed by overheating the transition to arc in atmospheric glow discharges is not a result of thermal instability. In second part of this research interaction between plasma filaments in dielectric barrier discharges has been studied. This interaction is responsible for the formation of microdischarge patterns reminiscent of two-dimensional crystals. Depending on the application, microdischarge patterns may have a significant influence on DBD performance

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

  2. Sediment discharge from highway construction near Port Carbon, Pennsylvania

    USGS Publications Warehouse

    Helm, Robert E.

    1978-01-01

    About 16,000 tons of suspended-sediment was discharged from the basin during the construction. The highway construction produced about 8,000 tons or 50 percent of the total sediment discharge. Steep slopes, the availability of fine coal wastes, coal-washing operations, and other land uses in the basin were responsible for most of the remaining sediment discharge. Seventy percent of the total suspended-sediment discharge occurred during eight storms.

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  4. Helium corona-assisted air discharge

    SciTech Connect

    Jiang Nan; Gao Lei; Ji Ailing; Cao Zexian

    2011-10-15

    Operation of atmospheric discharge of electronegative gases including air at low voltages yet without consuming any inert gas will enormously promote the application of non-thermal plasmas. By taking advantage of the low onset voltage for helium corona, air discharge was successfully launched at much reduced voltages with a needle-plate system partly contained in a helium-filled glass bulb--for a needle-plate distance of 12 mm, 1.0 kV suffices. Ultraviolet emission from helium corona facilitates the discharging of air, and the discharge current manifests distinct features such as relatively broad Trichel pulses in both half periods. This design allows safe and economic implementation of atmospheric discharge of electronegative gases, which will find a broad palette of applications in surface modification, plasma medicine and gas treatment, etc.

  5. Quasi-perpetual discharge behaviour in p-type Ge-air batteries.

    PubMed

    Ocon, Joey D; Kim, Jin Won; Abrenica, Graniel Harne A; Lee, Jae Kwang; Lee, Jaeyoung

    2014-11-07

    Metal-air batteries continue to become attractive energy storage and conversion systems due to their high energy and power densities, safer chemistries, and economic viability. Semiconductor-air batteries - a term we first define here as metal-air batteries that use semiconductor anodes such as silicon (Si) and germanium (Ge) - have been introduced in recent years as new high-energy battery chemistries. In this paper, we describe the excellent doping-dependent discharge kinetics of p-type Ge anodes in a semiconductor-air cell employing a gelled KOH electrolyte. Owing to its Fermi level, n-type Ge is expected to have lower redox potential and better electronic conductivity, which could potentially lead to a higher operating voltage and better discharge kinetics. Nonetheless, discharge measurements demonstrated that this prediction is only valid at the low current regime and breaks down at the high current density region. The p-type Ge behaves extremely better at elevated currents, evident from the higher voltage, more power available, and larger practical energy density from a very long discharge time, possibly arising from the high overpotential for surface passivation. A primary semiconductor-air battery, powered by a flat p-type Ge as a multi-electron anode, exhibited an unprecedented full discharge capacity of 1302.5 mA h gGe(-1) (88% anode utilization efficiency), the highest among semiconductor-air cells, notably better than new metal-air cells with three-dimensional and nanostructured anodes, and at least two folds higher than commercial Zn-air and Al-air cells. We therefore suggest that this study be extended to doped-Si anodes, in order to pave the way for a deeper understanding on the discharge phenomena in alkaline metal-air conversion cells with semiconductor anodes for specific niche applications in the future.

  6. ECH experiments aiming at further advanced operations in LHD

    SciTech Connect

    Igami, H.; Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Miyazawa, J.; Yamada, I.; Narihara, K.; Tamura, N.; Ida, K.; Mutoh, T.; Komori, A.; Inagaki, S.; Nagasaki, K.; Tanaka, H.; Maekawa, T.; Uchida, M.; Notake, T.

    2007-09-28

    In the Large helical device (LHD), super dense core (SDC) regime [1] and high electron temperature regime with formation of the electron internal transport barrier (e-ITB) [2][3] have been studied strenuously. Electron cyclotron heating (ECH) and current drive (ECCD) in such regimes can be powerful tools for heating and control of the plasma confinement. In this paper, recent progress of ECH experiments aiming at further advanced operation in these regimes is reported. Study of fundamental ECH by electron Bernstein waves (EBWs) has been required in the SDC regime. Early experimental results of EBW-ECH by so-called O-X-B and X-B method are introduced. In a newly realized enhanced magnetic field configuration, the highest central electron temperature over 10 keV was obtained in electron cyclotron resonance (ECR) discharges. ECCD will be very important in both of high density and high temperature regimes. It has been progressed with the optimization of microwave injection and magnetic field configuration. Progress of ECCD experiment is shortly introduced.

  7. Discharging dynamics in an electrolytic cell

    NASA Astrophysics Data System (ADS)

    Feicht, Sarah E.; Frankel, Alexandra E.; Khair, Aditya S.

    2016-07-01

    We analyze the dynamics of a discharging electrolytic cell comprised of a binary symmetric electrolyte between two planar, parallel blocking electrodes. When a voltage is initially applied, ions in the electrolyte migrate towards the electrodes, forming electrical double layers. After the system reaches steady state and the external current decays to zero, the applied voltage is switched off and the cell discharges, with the ions eventually returning to a uniform spatial concentration. At voltages on the order of the thermal voltage VT=kBT /q ≃25 mV, where kB is Boltzmann's constant, T is temperature, and q is the charge of a proton, experiments on surfactant-doped nonpolar fluids observe that the temporal evolution of the external current during charging and discharging is not symmetric [V. Novotny and M. A. Hopper, J. Electrochem. Soc. 126, 925 (1979), 10.1149/1.2129195; P. Kornilovitch and Y. Jeon, J. Appl. Phys. 109, 064509 (2011), 10.1063/1.3554445]. In fact, at sufficiently large voltages (several VT), the current during discharging is no longer monotonic: it displays a "reverse peak" before decaying in magnitude to zero. We analyze the dynamics of discharging by solving the Poisson-Nernst-Planck equations governing ion transport via asymptotic and numerical techniques in three regimes. First, in the "linear regime" when the applied voltage V is formally much less than VT, the charging and discharging currents are antisymmetric in time; however, the potential and charge density profiles during charging and discharging are asymmetric. The current evolution is on the R C timescale of the cell, λDL /D , where L is the width of the cell, D is the diffusivity of ions, and λD is the Debye length. Second, in the (experimentally relevant) thin-double-layer limit ɛ =λD/L ≪1 , there is a "weakly nonlinear" regime defined by VT≲V ≲VTln(1 /ɛ ) , where the bulk salt concentration is uniform; thus the R C timescale of the evolution of the current magnitude

  8. Impact of Te and ne on edge current density profiles in ELM mitigated regimes on ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Dunne, M. G.; Rathgeber, S.; Burckhart, A.; Fischer, R.; Giannone, L.; McCarthy, P. J.; Schneider, P. A.; Wolfrum, E.; the ASDEX Upgrade Team

    2015-01-01

    ELM resolved edge current density profiles are reconstructed using the CLISTE equilibrium code. As input, highly spatially and temporally resolved edge electron temperature and density profiles are used in addition to data from the extensive set of external poloidal field measurements available at ASDEX Upgrade, flux loop difference measurements, and current measurements in the scrape-off layer. Both the local and flux surface averaged current density profiles are analysed for several ELM mitigation regimes. The focus throughout is on the impact of altered temperature and density profiles on the current density. In particular, many ELM mitigation regimes rely on operation at high density. Two reference plasmas with type-I ELMs are analysed, one with a deuterium gas puff and one without, in order to provide a reference for the behaviour in type-II ELMy regimes and high density ELM mitigation with external magnetic perturbations at ASDEX Upgrade. For type-II ELMs it is found that while a similar pedestal top pressure is sustained at the higher density, the temperature gradient decreases in the pedestal. This results in lower local and flux surface averaged current densities in these phases, which reduces the drive for the peeling mode. No significant differences between the current density measured in the type-I phase and ELM mitigated phase is seen when external perturbations are applied, though the pedestal top density was increased. Finally, ELMs during the nitrogen seeded phase of a high performance discharge are analysed and compared to ELMs in the reference phase. An increased pedestal pressure gradient, which is the source of confinement improvement in impurity seeded discharges, causes a local current density increase. However, the increased Zeff in the pedestal acts to reduce the flux surface averaged current density. This dichotomy, which is not observed in other mitigation regimes, could act to stabilize both the ballooning mode and the peeling mode at the

  9. Pelvic radiation - discharge

    MedlinePlus

    Radiation of the pelvis - discharge; Cancer treatment - pelvic radiation; Prostate cancer - pelvic radiation; Ovarian cancer - pelvic radiation; Cervical cancer - pelvic radiation; Uterine cancer - pelvic radiation; Rectal cancer - ...

  10. ORAL ISSUE OF THE JOURNAL "USPEKHI FIZICHESKIKH NAUK": Modeling of gas discharge plasma

    NASA Astrophysics Data System (ADS)

    Smirnov, Boris M.

    2009-06-01

    The condition for the self-maintenance of a gas discharge plasma (GDP) is derived from its ionization balance expressed in the Townsend form and may be used as a definition of a gas discharge plasma in its simplest form. The simple example of a gas discharge plasma in the positive column of a cylindrical discharge tube allows demonstrating a wide variety of possible GDP regimes, revealing a contradiction between simple models used to explain gas discharge regimes and the large number of real processes responsible for the self-maintenance of GDP. The variety of GDP processes also results in a stepwise change of plasma parameters and developing some instabilities as the voltage or discharge current is varied. As a consequence, new forms and new applications of gas discharge arise as technology progresses.

  11. Computing discharge using the index velocity method

    USGS Publications Warehouse

    Levesque, Victor A.; Oberg, Kevin A.

    2012-01-01

    Application of the index velocity method for computing continuous records of discharge has become increasingly common, especially since the introduction of low-cost acoustic Doppler velocity meters (ADVMs) in 1997. Presently (2011), the index velocity method is being used to compute discharge records for approximately 470 gaging stations operated and maintained by the U.S. Geological Survey. The purpose of this report is to document and describe techniques for computing discharge records using the index velocity method. Computing discharge using the index velocity method differs from the traditional stage-discharge method by separating velocity and area into two ratings—the index velocity rating and the stage-area rating. The outputs from each of these ratings, mean channel velocity (V) and cross-sectional area (A), are then multiplied together to compute a discharge. For the index velocity method, V is a function of such parameters as streamwise velocity, stage, cross-stream velocity, and velocity head, and A is a function of stage and cross-section shape. The index velocity method can be used at locations where stage-discharge methods are used, but it is especially appropriate when more than one specific discharge can be measured for a specific stage. After the ADVM is selected, installed, and configured, the stage-area rating and the index velocity rating must be developed. A standard cross section is identified and surveyed in order to develop the stage-area rating. The standard cross section should be surveyed every year for the first 3 years of operation and thereafter at a lesser frequency, depending on the susceptibility of the cross section to change. Periodic measurements of discharge are used to calibrate and validate the index rating for the range of conditions experienced at the gaging station. Data from discharge measurements, ADVMs, and stage sensors are compiled for index-rating analysis. Index ratings are developed by means of regression

  12. Flywheel Charge/Discharge Control Developed

    NASA Technical Reports Server (NTRS)

    Beach, Raymond.F.; Kenny, Barbara H.

    2001-01-01

    A control algorithm developed at the NASA Glenn Research Center will allow a flywheel energy storage system to interface with the electrical bus of a space power system. The controller allows the flywheel to operate in both charge and discharge modes. Charge mode is used to store additional energy generated by the solar arrays on the spacecraft during insolation. During charge mode, the flywheel spins up to store the additional electrical energy as rotational mechanical energy. Discharge mode is used during eclipse when the flywheel provides the power to the spacecraft. During discharge mode, the flywheel spins down to release the stored rotational energy.

  13. Use of flumes in measuring discharge

    USGS Publications Warehouse

    Kilpatrick, F.A.; Schneider, V.R.

    1983-01-01

    Flumes for measuring discharge are usually of two general groups-critical-flow flumes and supercritical-flow flumes. In this chapter, the underlying design principles for each group are discussed; the most commonly used flumes are described and their discharge ratings presented. There is also discussion of considerations in choosing and fitting the appropriate flume for a given situation as well as flume construction techniques and operational experiences.

  14. Environment Flow Assessment with Flow Regime Transition

    NASA Astrophysics Data System (ADS)

    Su, J.; Ho, C. C.; Chang, L. C.

    2015-12-01

    To avoid worsen river and estuarine ecosystems cause by overusing water resources, environmental flows conservation is applied to reduce the impact of river environment. Environmental flows refer to water provided within a river, wetland or coastal zone to sustain ecosystems and benefits to human wellbeing. Environment flow assessment is now widely accepted that a naturally variable flow regime, rather than just a minimum low flow. In this study, we propose four methods, experience method, Tenant method, hydraulic method and habitat method to assess the environmental flow of base flow, flush flow and overbank flow with different discharge, frequency and occurrence period. Dahan River has been chosen as a case to demonstrate the assessment mechanism. The alternatives impact analysis of environment and human water used provides a reference for stakeholders when holding an environmental flow consultative meeting.

  15. Graywater Discharges from Vessels

    DTIC Science & Technology

    2011-11-01

    of members is 55; however, two have holding tanks and discharge shore-side and a third vessel is the car ferry Badger that discharges shore-side...Alaskan waters, and in numerous European ports such as Venice and Oslo ever since 2003. Model Capacitiy Load Installed Power

  16. Lithium battery discharge tests

    NASA Technical Reports Server (NTRS)

    Johnson, C. J.

    1980-01-01

    The long term discharge of a variety of lithium cells was characterized and the susceptibility of the cells to chemical variation during the slow discharge was tested. A shunt resistor was set across the terminals to monitor the voltage as a function of time. Failures were identified by premature voltage drops.

  17. Longitudinal discharge laser electrodes

    DOEpatents

    Warner, B.E.; Miller, J.L.; Ault, E.R.

    1994-08-23

    The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window. 2 figs.

  18. Longitudinal discharge laser electrodes

    DOEpatents

    Warner, Bruce E.; Miller, John L.; Ault, Earl R.

    1994-01-01

    The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window.

  19. Co-axial discharges

    DOEpatents

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

    1960-11-22

    An apparatus is described 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 diffuse to the more positive arc from the negative arc, and positive ions diffuse from the more positive arc to the negative arc. Coaxial arc discharges have the advantuge that ions that return to strike the positive arc discharge will lose no energy since they do not strike a solid wall or electrode. These 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 the plasma area because of the arc barrier set up by the cylindrical outer arc. (auth)

  20. CO-AXIAL DISCHARGES

    DOEpatents

    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.

  1. GAS DISCHARGE DEVICES

    DOEpatents

    Jefferson, S.

    1958-11-11

    An apparatus utilized in introducing tritium gas into envelope of a gas discharge device for the purpose f maintaining the discharge path in ionized condition is described. ln addition to the cathode and anode, the ischarge device contains a zirconium or tantalum ilament arranged for external excitation and a metallic seed containing tritium, and also arranged to have a current passed through it. Initially, the zirconium or tantalum filament is vaporized to deposit its material adjacent the main discharge region. Then the tritium gas is released and, due to its affinity for the first released material, it deposits in the region of the main discharge where it is most effective in maintaining the discharge path in an ionized condition.

  2. NPDES General Permit for Discharges from CAFOs in New Mexico

    EPA Pesticide Factsheets

    This general permit authorizes owners and operators of concentrated animal feeding operations in New Mexico, except those excluded, authorization to discharge, and sets forth effluent limitations, monitoring requirements and other provisions.

  3. Improving Hospital Discharge Time

    PubMed Central

    El-Eid, Ghada R.; Kaddoum, Roland; Tamim, Hani; Hitti, Eveline A.

    2015-01-01

    Abstract Delays in discharging patients can impact hospital and emergency department (ED) throughput. The discharge process is complex and involves setting specific challenges that limit generalizability of solutions. The aim of this study was to assess the effectiveness of using Six Sigma methods to improve the patient discharge process. This is a quantitative pre and post-intervention study. Three hundred and eighty-six bed tertiary care hospital. A series of Six Sigma driven interventions over a 10-month period. The primary outcome was discharge time (time from discharge order to patient leaving the room). Secondary outcome measures included percent of patients whose discharge order was written before noon, percent of patients leaving the room by noon, hospital length of stay (LOS), and LOS of admitted ED patients. Discharge time decreased by 22.7% from 2.2 hours during the preintervention period to 1.7 hours post-intervention (P < 0.001). A greater proportion of patients left their room before noon in the postintervention period (P < 0.001), though there was no statistical difference in before noon discharge. Hospital LOS dropped from 3.4 to 3.1 days postintervention (P < 0.001). ED mean LOS of patients admitted to the hospital was significantly lower in the postintervention period (6.9 ± 7.8 vs 5.9 ± 7.7 hours; P < 0.001). Six Sigma methodology can be an effective change management tool to improve discharge time. The focus of institutions aspiring to tackle delays in the discharge process should be on adopting the core principles of Six Sigma rather than specific interventions that may be institution-specific. PMID:25816029

  4. Radionuclides, Metals, and Hydrocarbons in Oil and Gas Operational Discharges and Environmental Samples Associated with Offshore Production Facilities on the Texas/Louisiana Continental Shelf with an Environmental Assessment of Metals and Hydrocarbons

    SciTech Connect

    Continental Shelf Associates, Inc.

    1999-08-16

    This report presents concentrations of radionuclides, metals, and hydrocarbons in samples of produced water and produced sand from oil and gas production platforms located offshore Texas and Louisiana. Concentrations in produced water discharge plume/receiving water, ambient seawater, sediment, interstitial water, and marine animal tissue samples collected in the vicinity of discharging platforms and reference sites distant from discharges are also reported and discussed. An environmental risk assessment is made on the basis of the concentrations of metals and hydrocarbons determined in the samples.

  5. Radionuclides, Metals, and Hydrocarbons in Oil and Gas Operational Discharges and Environmental Samples Associated with Offshore Production Facilities on the Texas/Louisiana Continental Shelf with an Environmental Assessment of Metals and Hydrocarbons.

    SciTech Connect

    1997-06-01

    This report presents concentrations of radionuclides, metals, and hydrocarbons in samples of produced water and produced sand from oil and gas production platforms located offshore Texas and Louisiana. concentrations in produced water discharge plume / receiving water, ambient seawater, sediment, interstitial water, and marine animal tissue samples collected in the vicinity of discharging platforms and reference sites distant from discharges are also reported and discussed. An environmental risk assessment is made on the basis of the concentration of metals and hydrocarbons determined in the samples.

  6. Dynamics and density distributions in a capillary-discharge waveguide with an embedded supersonic jet

    SciTech Connect

    Matlis, N. H. Gonsalves, A. J.; Steinke, S.; Tilborg, J. van; Shaw, B.; Mittelberger, D. E.; Geddes, C. G. R.; Matlis, E. H.; Leemans, W. P.

    2015-11-28

    We present an analysis of the gas dynamics and density distributions within a capillary-discharge waveguide with an embedded supersonic jet. This device provides a target for a laser plasma accelerator which uses longitudinal structuring of the gas-density profile to enable control of electron trapping and acceleration. The functionality of the device depends sensitively on the details of the density profile, which are determined by the interaction between the pulsed gas in the jet and the continuously-flowing gas in the capillary. These dynamics are captured by spatially resolving recombination light from several emission lines of the plasma as a function of the delay between the jet and the discharge. We provide a phenomenological description of the gas dynamics as well as a quantitative evaluation of the density evolution. In particular, we show that the pressure difference between the jet and the capillary defines three regimes of operation with qualitatively different longitudinal density profiles and show that jet timing provides a sensitive method for tuning between these regimes.

  7. Ion kinetics and self pulsing in DC microplasma discharges at atmospheric and higher pressure

    NASA Astrophysics Data System (ADS)

    Mahamud, Rajib; Farouk, Tanvir I.

    2016-04-01

    Atmospheric pressure microplasma devices have been the subject of considerable interest and research during the last decade. Most of the operation regime of the plasma discharges studied fall in the ‘abnormal’, ‘normal’ and ‘corona’ modes—increasing and a ‘flat’ voltage current characteristics. However, the negative differential resistance regime at atmospheric and high pressures has been less studied and possesses unique characteristics that can be employed for novel applications. In this work, the role of ion kinetics especially associated with trace impurities; on the self pulsing behavior has been investigated. Detailed numerical simulations have been conducted with a validated model for a helium-nitrogen feed gas mixture. Different oscillatory modes were observed where the discharge was found to undergo complete or partial relaxation. Trace amount of nitrogen was found to significantly alter the pulsing characteristics. External parameters influencing these self oscillations are also studied and aspects of the ion kinetics on the oscillatory behavior are discussed.

  8. Numerical investigation of dielectric barrier discharges

    NASA Astrophysics Data System (ADS)

    Li, Jing

    1997-12-01

    A dielectric barrier discharge (DBD) is a transient discharge occurring between two electrodes in coaxial or planar arrangements separated by one or two layers of dielectric material. The charge accumulated on the dielectric barrier generates a field in a direction opposite to the applied field. The discharge is quenched before an arc is formed. It is one of the few non-thermal discharges that operates at atmospheric pressure and has the potential for use in pollution control. In this work, a numerical model of the dielectric barrier discharge is developed, along with the numerical approach. Adaptive grids based on the charge distribution is used. A self-consistent method is used to solve for the electric field and charge densities. The Successive Overrelaxation (SOR) method in a non-uniform grid spacing is used to solve the Poisson's equation in the cylindrically-symmetric coordinate. The Flux Corrected Transport (FCT) method is modified to solve the continuity equations in the non-uniform grid spacing. Parametric studies of dielectric barrier discharges are conducted. General characteristics of dielectric barrier discharges in both anode-directed and cathode-directed streamer are studied. Effects of the dielectric capacitance, the applied field, the resistance in external circuit and the type of gases (O2, air, N2) are investigated. We conclude that the SOR method in an adaptive grid spacing for the solution of the Poisson's equation in the cylindrically-symmetric coordinate is convergent and effective. The dielectric capacitance has little effect on the g-factor of radical production, but it determines the strength of the dielectric barrier discharge. The applied field and the type of gases used have a significant role on the current peak, current pulse duration and radical generation efficiency, discharge strength, and microstreamer radius, whereas the external series resistance has very little effect on the streamer properties. The results are helpful in

  9. Lubrication regimes in lumbar total disc arthroplasty.

    PubMed

    Shaheen, A; Shepherd, D E T

    2007-08-01

    A number of total disc arthroplasty devices have been developed. Some concern has been expressed that wear may be a potential failure mode for these devices, as has been seen with hip arthroplasty. The aim of this paper was to investigate the lubrication regimes that occur in lumbar total disc arthroplasty devices. The disc arthroplasty was modelled as a ball-and-socket joint. Elastohydrodynamic lubrication theory was used to calculate the minimum film thickness of the fluid between the bearing surfaces. The lubrication regime was then determined for different material combinations, size of implant, and trunk velocity. Disc arthroplasties with a metal-polymer or metal-metal material combination operate with a boundary lubrication regime. A ceramic-ceramic material combination has the potential to operate with fluid-film lubrication. Disc arthroplasties with a metal-polymer or metal-metal material combination are likely to generate wear debris. In future, it is worth considering a ceramic-ceramic material combination as this is likely to reduce wear.

  10. Investigation of the regimes of mixing of superconducting tunneling structures

    NASA Astrophysics Data System (ADS)

    Kalashnikov, K. V.; Artanov, A. A.; Filippenko, L. V.; Koshelets, V. P.

    2016-11-01

    The regimes of operation of a superconductor-insulator-superconductor tunnel junction based on three-layer structures Nb/AlOx/Nb and Nb/AlN/NbN as a harmonic mixer (for frequencies of the order of 600 and 20 GHz, respectively) and a frequency up-converter (in the frequency range from 0.1 to 5.0 GHz) have been investigated experimentally. The quasiparticle and Josephson mixing regimes have been compared. It has been shown that, in some practical applications, such as the use of the superconductor-insulator-superconductor junction as a cryogenic harmonic phase detector, the Josephson mixing regime is more preferable, because it can provide a higher signal and a greater signal-to-noise ratio as compared to the quasiparticle mixing regime. It has also been demonstrated that the Josephson mixing regime is promising for the use in signal multiplexing systems for superconducting detectors.

  11. The Electrical Characteristics of a Filamentary Dielectric Barrier Discharge

    SciTech Connect

    Tay, W. H.; Yap, S. L.; Wong, C. S.

    2010-07-07

    The electrical characteristics of a filamentary dielectric barrier discharge using parallel-plate electrodes geometry were statistically studied. The DBD's system was powered by a 50 Hz power supply and operated at atmospheric pressure. The influence of the air gap and position of dielectric on the discharge had been investigated. It was found that the air gap distance and position of dielectric had significant influence on the discharge current pulse. The results showed that discharge with large distance between the high voltage electrode and the dielectric would generate higher current pulses during the positive cycle. The discharge energy of single pulse was also determined.

  12. Electric field in an AC dielectric barrier discharge overlapped with a nanosecond pulse discharge

    NASA Astrophysics Data System (ADS)

    Goldberg, Benjamin M.; Shkurenkov, Ivan; Adamovich, Igor V.; Lempert, Walter R.

    2016-08-01

    The effect of ns discharge pulses on the AC barrier discharge in hydrogen in plane-to-plane geometry is studied using time-resolved measurements of the electric field in the plasma. The AC discharge was operated at a pressure of 300 Torr at frequencies of 500 and 1750 Hz, with ns pulses generated when the AC voltage was near zero. The electric field vector is measured by ps four-wave mixing technique, which generates coherent IR signal proportional to the square of electric field. Absolute calibration was done using an electrostatic (sub-breakdown) field applied to the discharge electrodes, when no plasma was generated. The results are compared with one-dimensional kinetic modeling of the AC discharge and the nanosecond pulse discharge, predicting behavior of both individual micro-discharges and their cumulative effect on the electric field distribution in the electrode gap, using stochastic averaging based on the experimental micro-discharge temporal probability distribution during the AC period. Time evolution of the electric field in the AC discharge without ns pulses, controlled by a superposition of random micro-discharges, exhibits a nearly ‘flat top’ distribution with the maximum near breakdown threshold, reproduced quite well by kinetic modeling. Adding ns pulse discharges on top of the AC voltage waveform changes the AC discharge behavior in a dramatic way, inducing transition from random micro-discharges to a more regular, near-1D discharge. In this case, reproducible volumetric AC breakdown is produced at a well-defined moment after each ns pulse discharge. During the reproducible AC breakdown, the electric field in the plasma exhibits a sudden drop, which coincides in time with a well-defined current pulse. This trend is also predicted by the kinetic model. Analysis of kinetic modeling predictions shows that this effect is caused by large-volume ionization and neutralization of surface charges on the dielectrics by ns discharge pulses. The present

  13. Steady and transient regimes in hydropower plants

    NASA Astrophysics Data System (ADS)

    Gajic, A.

    2013-12-01

    Hydropower plant that has been in operation for about 30 years has to be reconstructed. They have already installed 12 Kaplan turbines, the largest in the world at that time. The existing CAM relationship was determined based on hydraulic model tests and checked by efficiency on-site tests. It was also tested based on turbine bearing vibrations. In order to discover vibrations and long cracks on stay vanes detailed on-site measurements were performed. Influence of the modification of the trailing edges on the dynamic stresses of the stay vanes is also shown. In order to improve power output transient regimes were analyzed, both experimentally and numerically. Reversible hydropower plant, a pioneer in Europe since it was the first Pump storage power plant constructed with the highest head pump-turbines in the world. Analyses of transient regimes discover some problems with S-shaped characteristics coupled with non-symmetrical penstock.

  14. Glow discharge detector

    DOEpatents

    Koo, Jackson C.; Yu, Conrad M.

    2002-01-01

    A highly sensitive electronic ion cell for the measurement of trace elements in He carrier gas which involves glow discharge. A constant wave (CW) glow discharge detector which is controlled through a biased resistor, can detect the change of electron density caused by impurities in the He carrier gas by many orders of magnitude larger than that caused by direct ionization or electron capture. The glow discharge detector utilizes a floating pseudo-electrode to form a probe in or near the plasma. By using this probe, the large variation of electron density due to trace amounts of impurities can be directly measured.

  15. Discharge lamp technologies

    NASA Technical Reports Server (NTRS)

    Dakin, James

    1994-01-01

    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 advances.

  16. Stochastic regimes in very-low-frequency fluidic oscillator

    NASA Astrophysics Data System (ADS)

    Tesař, Václav

    2016-03-01

    Paper discusses interesting unexpected stochastic regimes discovered in a fluidic oscillator designed for operation at very low oscillation frequencies - without the inconvenience of the long feedback loops needed in standard low-frequency oscillator designs. The new oscillator contains a pair of bistable turn-down active valves operating in anti-parallel — essentially analogous to Abraham & Bloch electric "multibrateur" invented in 1919. Three different self-excited oscillation regimes were found. In the order of increasing supplied flow rate, these regimes are characterised by: (A) generation of stochastic-duration multi-pulse packs, (B) generation of individual pulses with a degree of periodicity, and (C) regime with randomly appearing flow pulses separated by intervals of the order of seconds.

  17. Time-of-Flight Mass Spectrometry with a Pulsed Glow Discharge Ionization Source.

    PubMed

    Steiner, R E; Lewis, C L; King, F L

    1997-05-01

    The pulsed glow discharge (GD) plasma source exhibits several characteristics that make it ideally suited for use with time-of-flight mass spectrometry (TOFMS). TOFMS uniquely affords the ability to monitor a narrow temporal window for a time-varying process such as ion formation in the pulsed glow discharge plasma. Pulsed GD-TOFMS exhibited distinct advantages for the direct determination of trace elements in solid state samples. Initially, the pulse-powered GD-TOFMS system used for these investigations exhibited poor resolution. In an effort to improve resolution, a slit was introduced to narrow the ion beam orthogonally entering the extraction region of the TOFMS. In an effort to determine optimal operating conditions, the influence of slit width on TOF performance was investigated. In the course of this study, the slit width was found to influence isotope ratio accuracy as well as resolution. A slit width of 1.0 mm was determined to provide the best compromise between resolution and isotope ratio accuracy. Pulsed GD-TOFMS affords improved sensitivity and selectivity because Penning ionization is enhanced during the time period immediately following the termination of the discharge power. Ions sampled by an extraction pulse applied after power termination also yield a mass spectrum that is free of contributions arising from electron-ionized interferences. This advantage arises because only ions generated via the Penning ionization mechanism persist after the termination of discharge power. Sampling in the "afterpeak" time regime eliminates the saturation of the detector arising from discharge support gas ion signal.

  18. Breast radiation - discharge

    MedlinePlus

    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 ...

  19. Brain radiation - discharge

    MedlinePlus

    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 ...

  20. Heart failure - discharge

    MedlinePlus

    ... Heart failure - overview Heart pacemaker High blood pressure Implantable cardioverter-defibrillator Smoking - tips on how to quit ... ask your doctor How to read food labels Implantable cardioverter defibrillator - discharge Low-salt diet Mediterranean diet ...

  1. Concussion - child - discharge

    MedlinePlus

    ... 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 ...

  2. Capacitor discharge pulse analysis.

    SciTech Connect

    Baker, Michael Sean; Griffiths, Stewart K.; Tanner, Danelle Mary

    2013-08-01

    Capacitors used in firing sets and other high discharge current applications are discharge tested to verify performance of the capacitor against the application requirements. Parameters such as capacitance, inductance, rise time, pulse width, peak current and current reversal must be verified to ensure that the capacitor will meet the application needs. This report summarizes an analysis performed on the discharge current data to extract these parameters by fitting a second-order system model to the discharge data and using this fit to determine the resulting performance metrics. Details of the theory and implementation are presented. Using the best-fit second-order system model to extract these metrics results in less sensitivity to noise in the measured data and allows for direct extraction of the total series resistance, inductance, and capacitance.

  3. Multiple sclerosis - discharge

    MedlinePlus

    ... 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 ...

  4. Uterine artery embolization - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000161.htm Uterine artery embolization - discharge To use the sharing features on this page, please enable JavaScript. You had uterine artery embolization (UAE). UAE is a procedure to treat ...

  5. Deep vein thrombosis - discharge

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000027.htm Deep vein thrombosis - discharge To use the sharing features ... page, please enable JavaScript. You were treated for deep vein thrombosis ( DVT ). This is a condition in ...

  6. Knee arthroscopy - discharge

    MedlinePlus

    ... remove it. Torn or damaged anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) Inflamed or damaged ... surgery Knee pain Meniscal allograft transplantation Patient Instructions ACL reconstruction - discharge Getting your home ready - knee or ...

  7. Corneal transplant - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000243.htm Corneal transplant - discharge To use the sharing features on this page, please enable JavaScript. You had a corneal transplant. Most of the tissue of your cornea (the ...

  8. Shoulder replacement - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000178.htm Shoulder replacement - discharge To use the sharing features on this page, please enable JavaScript. You had shoulder replacement surgery to replace the bones of your shoulder ...

  9. Electric discharge during electrosurgery

    PubMed Central

    Shashurin, Alexey; Scott, David; Zhuang, Taisen; Canady, Jerome; Beilis, Isak I.; Keidar, Michael

    2015-01-01

    Electric discharge utilized for electrosurgery is studied by means of a recently developed method for the diagnostics of small-size atmospheric plasma objects based on Rayleigh scattering of microwaves on the plasma volume. Evolution of the plasma parameters in the near-electrode sheaths and in the positive column is measured and analyzed. It is found that the electrosurgical system produces a glow discharge of alternating current with strongly contracted positive column with current densities reaching 103 A/cm2. The plasma electron density and electrical conductivities in the channel were found be 1016 cm−3 and (1-2) Ohm−1cm−1, respectively. The discharge interrupts every instance when the discharge-driving AC voltage crosses zero and re-ignites again every next half-wave at the moment when the instant voltage exceeds the breakdown threshold. PMID:25880721

  10. Femur fracture repair - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000166.htm Femur fracture repair - discharge To use the sharing features on this page, please enable JavaScript. You had a fracture (break) in the femur in your leg. It ...

  11. Crohn disease - discharge

    MedlinePlus

    ... diet Nasogastric feeding tube Small bowel resection - discharge Review Date 12/2/2014 Updated by: Jenifer K. ... Frankford-Torresdale Hospital, Aria Health System, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by ...

  12. Cosmetic breast surgery - discharge

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000273.htm Cosmetic breast surgery - discharge To use the sharing features on this page, please enable JavaScript. You had cosmetic breast surgery to change the size or shape ...

  13. Shoulder surgery - discharge

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000179.htm Shoulder surgery - discharge To use the sharing features on this page, please enable JavaScript. You had shoulder surgery to repair the tissues inside or around ...

  14. Pneumonia - children - discharge

    MedlinePlus

    ... 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 ...

  15. Discharge parameters and dominant electron conductivity mechanism in a low-pressure planar magnetron discharge

    SciTech Connect

    Baranov, O.; Romanov, M.; Ostrikov, Kostya

    2009-06-15

    Parameters of a discharge sustained in a planar magnetron configuration with crossed electric and magnetic fields are studied experimentally and numerically. By comparing the data obtained in the experiment with the results of calculations made using the proposed theoretical model, conclusion was made about the leading role of the turbulence-driven Bohm electron conductivity in the low-pressure operation mode (up to 1 Pa) of the discharge in crossed electric and magnetic fields. A strong dependence of the width of the cathode sputter trench, associated with the ionization region of the magnetron discharge, on the discharge parameters was observed in the experiments. The experimental data were used as input parameters in the discharge model that describes the motion of secondary electrons across the magnetic field in the ionization region and takes into account the classical, near-wall, and Bohm mechanisms of electron conductivity.

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

    PubMed

    Mulling, Bram T M; van den Boomen, Rob M; van der Geest, Harm G; Kappelhof, Joost W N M; Admiraal, Wim

    2013-03-01

    Constructed wetlands (CWs) have been shown to improve the water quality of treated wastewater. The capacity of CWs to reduce nutrients, pathogens and organic matter and restore oxygen regime under normal operating conditions cannot be extrapolated to periods of incidental peak discharges. The buffering capacity of CWs during peak discharges is potentially a key factor for water quality in the receiving waters. Therefore, the aim of the present study was to investigate the behaviour of peak discharges of suspended particles, (associated) physiochemical parameters and pathogenic organisms from a wastewater treatment plant (WWTP) in a full scale constructed wetland (CW). By mixing clarified water and sludge rich water from the settlement tank of the WWTP, the suspended particle concentration was increased for 8 h from ± 3.5 to ± 230 mg L(-1), and discharged into a full scale horizontal surface flow constructed wetland. An increase of suspended particle concentration following the peak discharge concurred with increases in turbidity and oxygen demand, total nutrient load (nitrogen, phosphorus and carbon) and pathogens (Escherichia coli and Enterococci). Temperature, pH, conductivity and dissolved nutrient concentrations (nitrogen, phosphorus and carbon) were however unaffected by the initial peak discharge. After retention in the unvegetated ponds (the first CW compartment) the applied suspended particle peak with a total load of 86.2 kg was reduced by >99%. Similar peak buffering was observed for the turbidity, oxygen demand and settable volume. Simultaneously dissolved nutrient concentrations increased, indicating partial mineralization of the suspended particles during retention in the unvegetated ponds. The peak buffering of pathogens was lower (40-84%), indicating differences in removal processes between other suspended particles and pathogens. The results indicated that the suspended particles were probably mostly removed by sedimentation and mineralization

  17. Detecting spatial regimes in ecosystems

    EPA Science Inventory

    Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological ...

  18. Computational simulation of coupled nonequilibrium discharge and compressible flow phenomena in a microplasma thruster

    NASA Astrophysics Data System (ADS)

    Deconinck, Thomas; Mahadevan, Shankar; Raja, Laxminarayan L.

    2009-09-01

    The microplasma thruster (MPT) concept is a simple extension of a cold gas micronozzle propulsion device, where a direct-current microdischarge is used to preheat the gas stream to improve the specific impulse of the device. Here we study a prototypical MPT device using a detailed, self-consistently coupled plasma and flow computational model. The model describes the microdischarge power deposition, plasma dynamics, gas-phase chemical kinetics, coupling of the plasma phenomena with high-speed flow, and overall propulsion system performance. Compared to a cold gas micronozzle, a significant increase in specific impulse is obtained from the power deposition in the diverging section of the MPT nozzle. For a discharge voltage of 750 V, a power input of 650 mW, and an argon mass flow rate of 5 SCCM (SCCM denotes cubic centimeter per minute at STP), the specific impulse of the device is increased by a factor of ˜1.5 to about 74 s. The microdischarge remains mostly confined inside the micronozzle and operates in an abnormal glow discharge regime. Gas heating, primarily due to ion Joule heating, is found to have a strong influence on the overall discharge behavior. The study provides a validation of the MPT concept as a simple and effective approach to improve the performance of micronozzle cold gas propulsion devices.

  19. Computational simulation of coupled nonequilibrium discharge and compressible flow phenomena in a microplasma thruster

    SciTech Connect

    Deconinck, Thomas; Mahadevan, Shankar; Raja, Laxminarayan L.

    2009-09-15

    The microplasma thruster (MPT) concept is a simple extension of a cold gas micronozzle propulsion device, where a direct-current microdischarge is used to preheat the gas stream to improve the specific impulse of the device. Here we study a prototypical MPT device using a detailed, self-consistently coupled plasma and flow computational model. The model describes the microdischarge power deposition, plasma dynamics, gas-phase chemical kinetics, coupling of the plasma phenomena with high-speed flow, and overall propulsion system performance. Compared to a cold gas micronozzle, a significant increase in specific impulse is obtained from the power deposition in the diverging section of the MPT nozzle. For a discharge voltage of 750 V, a power input of 650 mW, and an argon mass flow rate of 5 SCCM (SCCM denotes cubic centimeter per minute at STP), the specific impulse of the device is increased by a factor of approx1.5 to about 74 s. The microdischarge remains mostly confined inside the micronozzle and operates in an abnormal glow discharge regime. Gas heating, primarily due to ion Joule heating, is found to have a strong influence on the overall discharge behavior. The study provides a validation of the MPT concept as a simple and effective approach to improve the performance of micronozzle cold gas propulsion devices.

  20. Characterization of thin-film deposition in a pulsed acrylic acid polymerizing discharge

    SciTech Connect

    Voronin, Sergey A.; Bradley, James W.; Fotea, Catalin; Zelzer, Mischa; Alexander, Morgan R.

    2007-07-15

    In this study, thin-film deposition in a pulsed rf polymerizing discharge (13.56 MHz) struck in acrylic acid has been investigated by mass spectrometry, x-ray photoelectron spectroscopy, and quartz crystal microbalance techniques. The experiment was conducted at a fixed acrylic acid pressure of 1.3 Pa and 'on' pulse duration of 0.1 ms, whereas the 'off' time was varied between 0 and 20 ms. The rf input power in the 'on' time and gas flow rate were varied between 10 and 50 W and 1.5 and 4.8 sccm (sccm denotes cubic centimeter per minute at STP), respectively. These changes of the discharge conditions resulted in large-scale progressive variations in film and gas-phase plasma composition. In particular, the -COOH functionality of the monomer was increasingly retained in the plasma-generated thin films as the duty cycle was lowered (i.e., with lowered time-averaged powers). The monomer retention reached its maximum value of 66% for 'off' times exceeding 5 ms, when the discharge was operating in the power-deficient regime. The results show that the film deposition rate is a strong function of the monomer flow rate, whereas -COOH retention is correlated to the amount of unfragmented monomer in the plasma, controlled by the applied power.

  1. Simulation study of one-dimensional self-organized pattern in an atmospheric-pressure dielectric barrier discharge

    SciTech Connect

    Zhang, Jiao; Wang, Yanhui Wang, Dezhen

    2015-04-15

    A two-dimensional fluid model is developed to simulate the one-dimensional self-organized patterns in an atmospheric-pressure dielectric barrier discharge (DBD) driven by sinusoidal voltage in argon. Under certain conditions, by changing applied voltage amplitude, the transversely uniform discharge can evolve into the patterned discharge and the varied self-organized patterned discharges with different numbers and arrangements of discharge channels can be observed. Similar to the uniform atmospheric-pressure DBD, the patterned discharge mode is found to undergo a transition from Townsend regime, sub-glow regime to glow regime with increasing applied voltage amplitude. In the different regimes, charged particles and electric field display different dynamical behaviors. If the voltage amplitude is increased over a certain value, the discharge enters an asymmetric patterned discharge mode, and then transforms into the spatially chaotic state with out-of-order discharge channels. The reason for forming the one-dimensional self-organized pattern is mainly due to the so-called activation-inhibition effect resulting from the local high electron density region appearing in discharge space. Electrode arrangement is the reason that induces local high electron density.

  2. Pulsed operation of low-power plasma thruster

    NASA Astrophysics Data System (ADS)

    Bugrova, A. I.; Desyatskov, A. V.; Korobkin, Yu. V.; Lipatov, A. S.; Kharchevnikov, V. K.

    2010-10-01

    Integral and local characteristics of the laboratory model of a low-power plasma thruster operating in a pulsed regime have been experimentally studied. Rectangular pulses of discharge current with the leading and trailing fronts not exceeding 1 ms have been obtained. At an average supplied electric power of ˜150 W, the propulsion efficiency amounted to 35%. The plasma concentration, electron temperature, and potential distributions in the output plasma jet have been measured using an electric probe. These measurements showed that a well formed plasma jet with a small divergence angle exists behind the thruster edge.

  3. Cold starting of fluorescent lamps - part I: a description of the transient regime

    NASA Astrophysics Data System (ADS)

    Langer, Reinhard; Garner, Richard; Paul, Irina; Horn, Siegfried; Tidecks, Reinhard

    2016-10-01

    In this paper we give a proposal for the transient behaviour of a cold-started fluorescent lamp, from the generation of the first conductive channel over the normal and abnormal glow discharge and the glow-to-arc (GTA) transition to the arc discharge in the steady state. Starting from the equilibrium voltage-current characteristics of the lamp and considering recent experimental results a qualitative description of the transient regime is developed, which was so far not available in the literature.

  4. 75 FR 20592 - Notice of Availability of Draft National Pollutant Discharge Elimination System (NPDES) General...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-20

    ... where the property discharges wholly into an MS4 system operated by that local, state or federal... government unit where the property discharges wholly into an MS4 system operated by that local, state or... AGENCY Notice of Availability of Draft National Pollutant Discharge Elimination System (NPDES)...

  5. 33 CFR 159.315 - Sewage and graywater discharge record book.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... by Cruise Vessel Operations § 159.315 Sewage and graywater discharge record book. (a) While operating in the applicable waters of Alaska each cruise vessel shall maintain, in English, a legible Sewage... and location of each discharge port within the ship; (2) Date the start of discharge occurred;...

  6. 33 CFR 159.315 - Sewage and graywater discharge record book.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... by Cruise Vessel Operations § 159.315 Sewage and graywater discharge record book. (a) While operating in the applicable waters of Alaska each cruise vessel shall maintain, in English, a legible Sewage... and location of each discharge port within the ship; (2) Date the start of discharge occurred;...

  7. 33 CFR 159.315 - Sewage and graywater discharge record book.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... by Cruise Vessel Operations § 159.315 Sewage and graywater discharge record book. (a) While operating in the applicable waters of Alaska each cruise vessel shall maintain, in English, a legible Sewage... and location of each discharge port within the ship; (2) Date the start of discharge occurred;...

  8. 33 CFR 159.315 - Sewage and graywater discharge record book.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... by Cruise Vessel Operations § 159.315 Sewage and graywater discharge record book. (a) While operating in the applicable waters of Alaska each cruise vessel shall maintain, in English, a legible Sewage... and location of each discharge port within the ship; (2) Date the start of discharge occurred;...

  9. Pedestal characterization and stability of small-ELM regimes in NSTX

    SciTech Connect

    Sontag, Aaron C; Canik, John; Maingi, Rajesh; Manickam, J.; Snyder, P.; Bell, R. E.; Gerhardt, S.P.; Kubota, S.; LaBlanc, B. P.; Mueller, D.; Osborne, T.; Tritz, K.

    2011-01-01

    An instability near the plasma edge known as the edge harmonic oscillation (EHO) is thought to enable access to the ELM-free quiescent H-mode (QH-mode) in tokamaks, which is a highly desirable operational regime for ITER because of the avoidance of periodic ELM heat loads. The EHO has been hypothesized to be a saturated kink driven unstable by toroidal rotational shear that provides sufficient transport near the plasma edge to keep the edge plasma below the peeling-ballooning stability limit. NSTX has observed unstable modes with similar characteristics to the EHO coincident with transition to a small-ELM regime (called Type-V). These small ELMs do not have a measurable effect on the plasma stored energy (< 1%). Transition to this regime is associated with a downward biased plasma as evidenced by drsep < -5 mm. Soft x-ray emission indicates that these modes are localized just inside the pedestal and are correlated with increased density fluctuations in the pedestal as measured by microwave reflectometry. The lowest order mode rotates at the plasma rotation frequency, indicating n=1, and harmonics up to n=6 have been observed simultaneously with the n=1, as determined by the rotation frequency of the higher harmonics. Increased edge collisionality is required to access Type-V ELMs. Stability analysis during the observed modes indicates instability to n=1-3 with n=3 having the highest growth rate and unstable mode eigenfunctions peaked near the plasma edge. Discharges with Type-V and Type-I ELMs are both calculated to be on the peeling unstable side of the peeling ballooning stability curve, with the Type-V case at higher normalized pressure gradient.

  10. Pedestal Characterization and Stability of Small-ELM Regimes in NSTX

    SciTech Connect

    Sontag, Aaron C; Canik, John; Maingi, Rajesh; Manickam, J.; Snyder, P.; Bell, R. E.; Gerhardt, S.P.; Kubota, S.; LaBlanc, B. P.; Mueller, D.; Osborne, T.; Tritz, K.

    2010-01-01

    An instability near the plasma edge known as the edge harmonic oscillation (EHO) is thought to enable access to the ELM-free quiescent H-mode (QH-mode) in tokamaks, which is a highly desirable operational regime for ITER because of the avoidance of periodic ELM heat loads. The EHO has been hypothesized to be a saturated kink driven unstable by toroidal rotational shear that provides sufficient transport near the plasma edge to keep the edge plasma below the peeling-ballooning stability limit. NSTX has observed unstable modes with similar characteristics to the EHO coincident with transition to a small-ELM regime (called Type-V). These small ELMs do not have a measurable effect on the plasma stored energy (< 1%). Transition to this regime is associated with a downward biased plasma as evidenced by drsep < -5 mm. Soft x-ray emission indicates that these modes are localized just inside the pedestal and are correlated with increased density fluctuations in the pedestal as measured by microwave reflectometry. The lowest order mode rotates at the plasma rotation frequency, indicating n=1, and harmonics up to n=6 have been observed simultaneously with the n=1, as determined by the rotation frequency of the higher harmonics. Increased edge collisionality is required to access Type-V ELMs. Stability analysis during the observed modes indicates instability to n=1-3 with n=3 having the highest growth rate and unstable mode eigenfunctions peaked near the plasma edge. Discharges with Type-V and Type-I ELMs are both calculated to be on the peeling unstable side of the peeling ballooning stability curve, with the Type-V case at higher normalized pressure gradient.

  11. Monitor For Electrical-Discharge Machining

    NASA Technical Reports Server (NTRS)

    Burley, Richard K.

    1993-01-01

    Circuit monitors electrical-discharge-machining (EDM) process to detect and prevent abnormal arcing, which can produce unacceptable "burn" marks on workpiece. When voltage between EDM electrode and workpiece behaves in manner indicative of abnormal arcing, relay made to switch off EDM power, which remains off until operator attends to EDM setup and resets monitor.

  12. High Power ECR Ion Thruster Discharge Characterization

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

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

  13. Stable glow discharge detector

    DOEpatents

    Koo, Jackson C.; Yu, Conrad M.

    2004-05-18

    A highly sensitive electronic ion cell for the measurement of trace elements in He carrier gas which involves glow discharge. A constant wave (CW) stable glow discharge detector which is controlled through a biased resistor, can detect the change of electron density caused by impurities in the He carrier gas by many orders of magnitude larger than that caused by direct ionization or electron capture. The stable glow discharge detector utilizes a floating pseudo-electrode to form a probe in or near the plasma and a solid rod electrode. By using this probe, the large variation of electron density due to trace amounts of impurities can be directly measured. The solid rod electrode provides greater stability and thus easier alignment.

  14. Identifying Biologically Relevant Cues in the Hydrologic Regime

    NASA Astrophysics Data System (ADS)

    Lovellford, R. M.; Flitcroft, R.; Santelmann, M. V.; Grant, G. E.; Safeeq, M.; Lewis, S.

    2012-12-01

    Seasonal variation in hydrologic discharge and temperature defines the availability, connectivity, and quality of lentic habitats. Native aquatic species are adapted to local hydrologic regimes , eg. magnitudes and rates of change . In recent decades, biologically relevant hydrologic conditions have been identified that are necessary to maintain habitat conditions for aquatic obligate species. Another element of hydrologic regimes important to aquatic species are the cues that inform individuals of seasonal changes that precipitate important physiological or behavioral alterations. There is a need for hydrologists, biologists, and ecologists, to define biologically significant cues within the hydrologic regime. Coho salmon (Onchorhynchus kisutch), an anadromous species of Pacific salmon, offers an example of sensitivity to environmental cues. Examinations of the run-timing of mature adult coho salmon on the North Umpqua River, OR, indicate that migration timing coincides with decreasing fall water temperatures prior to increasing winter discharge. For this species, adults leave the ocean ready to spawn. Adults need to spawn in small headwater streams prior to the onset of intense storm conditions that prohibit effective deposition or fertilization of eggs in redds (salmon nests).Therefore, the timing of spawning must be carefully executed. Understanding the cues that trigger specific behaviors gives insight to the processes that provide ecosystem stability and flexibility over time. Improved understanding of these cues may help us protect freshwater ecosystems and improve management for endangered species.

  15. Antarctic subglacial lake discharges

    NASA Astrophysics Data System (ADS)

    Pattyn, Frank

    Antarctic subglacial lakes were long time supposed to be relatively closed and stable environments with long residence times and slow circulations. This view has recently been challenged with evidence of active subglacial lake discharge underneath the Antarctic ice sheet. Satellite altimetry observations witnessed rapid changes in surface elevation across subglacial lakes over periods ranging from several months to more than a year, which were interpreted as subglacial lake discharge and subsequent lake filling, and which seem to be a common and widespread feature. Such discharges are comparable to jökulhlaups and can be modeled that way using the Nye-Röthlisberger theory. Considering the ice at the base of the ice sheet at pressure melting point, subglacial conduits are sustainable over periods of more than a year and over distances of several hundreds of kilometers. Coupling of an ice sheet model to a subglacial lake system demonstrated that small changes in surface slope are sufficient to start and sustain episodic subglacial drainage events on decadal time scales. Therefore, lake discharge may well be a common feature of the subglacial hydrological system, influencing the behavior of large ice sheets, especially when subglacial lakes are perched at or near the onset of large outlet glaciers and ice streams. While most of the observed discharge events are relatively small (101-102 m3 s-1), evidence for larger subglacial discharges is found in ice free areas bordering Antarctica, and witnessing subglacial floods of more than 106 m3 s-1 that occurred during the middle Miocene.

  16. Marine regime shifts: drivers and impacts on ecosystems services

    PubMed Central

    Rocha, J.; Yletyinen, J.; Biggs, R.; Blenckner, T.; Peterson, G.

    2015-01-01

    Marine ecosystems can experience regime shifts, in which they shift from being organized around one set of mutually reinforcing structures and processes to another. Anthropogenic global change has broadly increased a wide variety of processes that can drive regime shifts. To assess the vulnerability of marine ecosystems to such shifts and their potential consequences, we reviewed the scientific literature for 13 types of marine regime shifts and used networks to conduct an analysis of co-occurrence of drivers and ecosystem service impacts. We found that regime shifts are caused by multiple drivers and have multiple consequences that co-occur in a non-random pattern. Drivers related to food production, climate change and coastal development are the most common co-occurring causes of regime shifts, while cultural services, biodiversity and primary production are the most common cluster of ecosystem services affected. These clusters prioritize sets of drivers for management and highlight the need for coordinated actions across multiple drivers and scales to reduce the risk of marine regime shifts. Managerial strategies are likely to fail if they only address well-understood or data-rich variables, and international cooperation and polycentric institutions will be critical to implement and coordinate action across the scales at which different drivers operate. By better understanding these underlying patterns, we hope to inform the development of managerial strategies to reduce the risk of high-impact marine regime shifts, especially for areas of the world where data are not available or monitoring programmes are not in place.

  17. NSTX Filament Preionization and Glow Discharge Cleaning Systems

    SciTech Connect

    Kugel, H. W.; Blanchard, W.; D'Amico, G.; Gernhardt, R.; Provost, T.

    1999-11-01

    Initial NSTX GDC experiments were performed with one moveable anode and a biased filament preionization system that allowed D2 and He Glow Discharge breakdowns at the actual operating pressure, voltage and current. The biased filament system was also operated continuously during ohmic operations, and used to reduce volt-sec consumption for February 1999 plasma discharges up to 280 KA. An upgraded system has been installed with 2 fixed wall anodes and 3 biased filaments; 2 on the mid-plane and one in the divertor region; all separately controllable remotely using a PLC system. Recent applications include assisting in preionization for 800 KA plasma discharges.

  18. Cloud regimes as phase transitions

    NASA Astrophysics Data System (ADS)

    Stechmann, Samuel N.; Hottovy, Scott

    2016-06-01

    Clouds are repeatedly identified as a leading source of uncertainty in future climate predictions. Of particular importance are stratocumulus clouds, which can appear as either (i) closed cells that reflect solar radiation back to space or (ii) open cells that allow solar radiation to reach the Earth's surface. Here we show that these clouds regimes -- open versus closed cells -- fit the paradigm of a phase transition. In addition, this paradigm characterizes pockets of open cells as the interface between the open- and closed-cell regimes, and it identifies shallow cumulus clouds as a regime of higher variability. This behavior can be understood using an idealized model for the dynamics of atmospheric water as a stochastic diffusion process. With this new conceptual viewpoint, ideas from statistical mechanics could potentially be used for understanding uncertainties related to clouds in the climate system and climate predictions.

  19. MHD modeling of DIII-D QH-mode discharges and comparison to observations

    NASA Astrophysics Data System (ADS)

    King, Jacob

    2016-10-01

    MHD modeling of DIII-D QH-mode discharges and comparison to observations Nonlinear NIMROD simulations, initialized from a reconstruction of a DIII-D QH-mode discharge with broadband MHD, saturate into a turbulent state, but do not saturate when flow is not included. This is consistent with the experimental results of the quiescent regime observed on DIII-D with broadband MHD activity [Garofalo et al., PoP (2015) and refs. within]. These ELM-free discharges have the normalized pedestal-plasma confinement necessary for burning-plasma operation on ITER. Relative to QH-mode operation with more coherent MHD activity, operation with broadband MHD tends to occur at higher densities and lower rotation and thus may be more relevant to ITER. The nonlinear NIMROD simulations require highly accurate equilibrium reconstructions. Our equilibrium reconstructions include the scrape-off-layer profiles and the measured toroidal and poloidal rotation profiles. The simulation develops into a saturated turbulent state and the n=1 and 2 modes become dominant through an inverse cascade. Each toroidal mode in the range of n=1-5 is dominant at a different time. The perturbations are advected and sheared apart in the counter-clockwise direction consistent with the direction of the poloidal flow inside the LCFS. Work towards validation through comparison to magnetic coil and Doppler reflectometry measurements is presented. Consistent with experimental observations during QH-mode, the simulated state leads to large particle transport relative to the thermal transport. Analysis shows that the phase of the density and temperature perturbations differ resulting in greater convective particle transport relative to the convective thermal transport. This work supported by the U.S. Department of Energy Office of Science and the SciDAC Center for Extended MHD Modeling under Contract Numbers DE-FC02-06ER54875, DE-FC02-08ER54972 and DE-FC02-04ER54698.

  20. The effect of refrigerants in the mixed lubrication regime

    SciTech Connect

    Mizuhara, Kazuyuki; Tomimoto, Makoto

    1997-12-31

    Because of environmental concerns, CFC (chlorofluorocarbon) refrigerants must be replaced with HFCs (hydrofluorocarbons). As a result, many tribological problems are caused especially in rotary piston compressors. To solve the problem, the effects of refrigerants on friction and wear characteristics of the oil and refrigerant mixtures at the mixed lubrication regime are investigated. The difference in refrigerants are clearly observed not only in boundary but also in the mixed lubrication regime. The effects of operating conditions on sliding conditions and experimental results are also discussed. It is concluded that for practical application where long life is essential, experiments must be conducted under the mixed lubrication regime. Also, the importance of defining the lubrication regime in terms of film parameter is emphasized.

  1. Analysis of light regime in continuous light distributions in photobioreactors.

    PubMed

    Brindley, Celeste; Fernández, F G Acién; Fernández-Sevilla, J M

    2011-02-01

    Maximum photobioreactor (PBR) efficiency is a must in applications such as the obtention of microalgae-derived fuels. Improving PBR performance requires a better understanding of the "light regime", the varying irradiance that microalgal cells moving in a dense culture are exposed to. We propose a definition of light regime that can be used consistently to describe the continuously varying light patterns in PBRs as well as in light/dark cycles. Equivalent continuous and light/dark regimes have been experimentally compared and the results show that continuous variations are not well represented by light/dark cycles, as had been widely accepted. It has been shown that a correct light regime allows obtaining photosynthetic rates higher than the corresponding to continuous light, the so-called "flashing light effect" and that this is possible in commercial PBRs. A correct PBR operation could result in photosynthetic efficiency close to the optimum eight quanta per O(2).

  2. 46 CFR 153.964 - Discharge by gas pressurization.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Discharge by gas pressurization. 153.964 Section 153.964... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.964 Discharge by gas pressurization. The person in charge of cargo transfer may...

  3. 46 CFR 153.964 - Discharge by gas pressurization.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Discharge by gas pressurization. 153.964 Section 153.964... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.964 Discharge by gas pressurization. The person in charge of cargo transfer may...

  4. 21 CFR 1250.51 - Railroad conveyances; discharge of wastes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Railroad conveyances; discharge of wastes. 1250.51... CONVEYANCE SANITATION Equipment and Operation of Land and Air Conveyances § 1250.51 Railroad conveyances; discharge of wastes. (a) New railroad conveyances. Human wastes, garbage, waste water, or other...

  5. 21 CFR 1250.51 - Railroad conveyances; discharge of wastes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Railroad conveyances; discharge of wastes. 1250.51... CONVEYANCE SANITATION Equipment and Operation of Land and Air Conveyances § 1250.51 Railroad conveyances; discharge of wastes. (a) New railroad conveyances. Human wastes, garbage, waste water, or other...

  6. 21 CFR 1250.51 - Railroad conveyances; discharge of wastes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Railroad conveyances; discharge of wastes. 1250.51... CONVEYANCE SANITATION Equipment and Operation of Land and Air Conveyances § 1250.51 Railroad conveyances; discharge of wastes. (a) New railroad conveyances. Human wastes, garbage, waste water, or other...

  7. 46 CFR 153.966 - Discharge by liquid displacement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Discharge by liquid displacement. 153.966 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.966 Discharge by liquid displacement. The person in charge of cargo transfer...

  8. 46 CFR 153.966 - Discharge by liquid displacement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Discharge by liquid displacement. 153.966 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.966 Discharge by liquid displacement. The person in charge of cargo transfer...

  9. 46 CFR 153.966 - Discharge by liquid displacement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Discharge by liquid displacement. 153.966 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.966 Discharge by liquid displacement. The person in charge of cargo transfer...

  10. 46 CFR 153.966 - Discharge by liquid displacement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Discharge by liquid displacement. 153.966 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.966 Discharge by liquid displacement. The person in charge of cargo transfer...

  11. 46 CFR 153.966 - Discharge by liquid displacement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Discharge by liquid displacement. 153.966 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.966 Discharge by liquid displacement. The person in charge of cargo transfer...

  12. 33 CFR 157.31 - Discharges: Chemical additives.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Discharges: Chemical additives. 157.31 Section 157.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... OIL IN BULK Vessel Operation § 157.31 Discharges: Chemical additives. No person may use a...

  13. 33 CFR 157.31 - Discharges: Chemical additives.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Discharges: Chemical additives. 157.31 Section 157.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... OIL IN BULK Vessel Operation § 157.31 Discharges: Chemical additives. No person may use a...

  14. 33 CFR 157.31 - Discharges: Chemical additives.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Discharges: Chemical additives. 157.31 Section 157.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... OIL IN BULK Vessel Operation § 157.31 Discharges: Chemical additives. No person may use a...

  15. 33 CFR 157.31 - Discharges: Chemical additives.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Discharges: Chemical additives. 157.31 Section 157.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... OIL IN BULK Vessel Operation § 157.31 Discharges: Chemical additives. No person may use a...

  16. 33 CFR 157.31 - Discharges: Chemical additives.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Discharges: Chemical additives. 157.31 Section 157.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... OIL IN BULK Vessel Operation § 157.31 Discharges: Chemical additives. No person may use a...

  17. 2D fluid simulations of discharges at atmospheric pressure in reactive gas mixtures

    NASA Astrophysics Data System (ADS)

    Bourdon, Anne

    2015-09-01

    Since a few years, low-temperature atmospheric pressure discharges have received a considerable interest as they efficiently produce many reactive chemical species at a low energy cost. This potential is of great interest for a wide range of applications as plasma assisted combustion or biomedical applications. Then, in current simulations of atmospheric pressure discharges, there is the need to take into account detailed kinetic schemes. It is interesting to note that in some conditions, the kinetics of the discharge may play a role on the discharge dynamics itself. To illustrate this, we consider the case of the propagation of He-N2 discharges in long capillary tubes, studied for the development of medical devices for endoscopic applications. Simulation results put forward that the discharge dynamics and structure depend on the amount of N2 in the He-N2 mixture. In particular, as the amount of N2 admixture increases, the discharge propagation velocity in the tube increases, reaches a maximum for about 0 . 1 % of N2 and then decreases, in agreement with experiments. For applications as plasma assisted combustion with nanosecond repetitively pulsed discharges, there is the need to handle the very different timescales of the nanosecond discharge with the much longer (micro to millisecond) timescales of combustion processes. This is challenging from a computational point of view. It is also important to better understand the coupling of the plasma induced chemistry and the gas heating. To illustrate this, we present the simulation of the flame ignition in lean mixtures by a nanosecond pulsed discharge between two point electrodes. In particular, among the different discharge regimes of nanosecond repetitively pulsed discharges, a ``spark'' regime has been put forward in the experiments, with an ultra-fast local heating of the gas. For other discharge regimes, the gas heating is much weaker. We have simulated the nanosecond spark regime and have observed shock waves

  18. Effect of air flow on the micro-discharge dynamics in an array of integrated coaxial microhollow dielectric barrier discharges

    NASA Astrophysics Data System (ADS)

    Nayak, Gaurav; Du, Yanjun; Brandenburg, Ronny; Bruggeman, Peter J.

    2017-03-01

    The micro-discharge properties and evolution in a 2D array of integrated coaxial microhollow dielectric barrier discharges are studied by using highly time-resolved electrical and optical diagnostics. The study is focused on the effect of the gas flow rate and gas residence time on discharge properties. The investigated integrated coaxial microhollow discharge geometry allows operating the discharge at exceptionally small residence times, which can be equal to or even smaller than the discharge period, at reasonable gas flow rates. The gas flow has an impact on gas heating, residual humidity, pre-ionization density and the densities of excited and reactive species produced by previous discharges. A unique voltage–charge plot is obtained with elongated periods without discharge activity. A very significant effect of flow on NO emission is observed that relates to the impact of flow on the NO production in these micro-discharges. Using the emission intensities of molecular bands of the second positive system of nitrogen and the first negative system of the nitrogen ion, effective reduced electric field strengths are obtained with a maximum equal to 870 Td. The reduced electric field decreases with increasing gas flow rate. This behavior is consistent with the reduction of the overall discharge intensity due to a reduced amount of charges present in the discharge gap. Both the flow rate and a reduction in water impurity changing the ion mobility can be responsible for the different effective electric field distributions at the highest and no flow conditions.

  19. Longitudinal discharge laser baffles

    DOEpatents

    Warner, B.E.; Ault, E.R.

    1994-06-07

    The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam. 1 fig.

  20. Longitudinal discharge laser baffles

    DOEpatents

    Warner, Bruce E.; Ault, Earl R.

    1994-01-01

    The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam.

  1. Simulating Divertor Detachment of Ohmic Discharges in ASDEX Upgrade Using SOLPS: the Role of Carbon

    SciTech Connect

    Wischmeier, M; Coster, D; Chankin, A; Fuchs, C; Groth, M; Harhausen, J; Kallenbach, A; Muller, H; Tsalas, M; Wolfrum, E

    2007-06-27

    With divertor detachment being a prerequisite for burning plasma operation in ITER, numerical codes such as SOLPS [1] have been developed for predicting and interpreting the divertor performance at all operational regimes in current tokamaks and ITER. In ITER complete detachment from the outer divertor target is not permitted as this might result in an X-point MARFE, imposing an upper limit for the upstream separatrix density, n{sub e}{sup sep}. Despite the knowledge of the basic mechanisms required for achieving detachment, such as radiative power exhaust, volumetric momentum and charge removal [1], a quantitative evaluation of experimentally observed detached regimes proves to be particularly difficult for several tokamaks. In particular the strong asymmetry of the ion flux density between the inner, {Lambda}{sub it}, and the outer target {Lambda}{sub ot} with increasing line averaged density, {bar n}{sub e}, and in particular ''vanishing'' of the ion flux, defined as full/complete detachment, at the inner target cannot be reproduced. It is unclear how this is related to divertor target plates or other plasma facing components containing carbon. As part of a combined effort at various experimental devices this paper contributes to the validation of the SOLPS code against experimental data from ASDEX Upgrade, AUG, at the onset of divertor detachment. In the framework established under the International Tokamak Physics Activity (ITPA) Divertor and SOL working group a series of ohmic discharges have been performed in AUG, which had as similar as possible plasma parameters as companion discharges undertaken in DIII-D [2]. The effect of activating drift terms, the influence of the chemical sputtering yield at the inner target and in addition to [3] the role of impurity influx from the inner heat shield are analyzed.

  2. Determining the microwave coupling and operational efficiencies of a microwave plasma assisted chemical vapor deposition reactor under high pressure diamond synthesis operating conditions

    SciTech Connect

    Nad, Shreya; Gu, Yajun; Asmussen, Jes

    2015-07-15

    The microwave coupling efficiency of the 2.45 GHz, microwave plasma assisted diamond synthesis process is investigated by experimentally measuring the performance of a specific single mode excited, internally tuned microwave plasma reactor. Plasma reactor coupling efficiencies (η) > 90% are achieved over the entire 100–260 Torr pressure range and 1.5–2.4 kW input power diamond synthesis regime. When operating at a specific experimental operating condition, small additional internal tuning adjustments can be made to achieve η > 98%. When the plasma reactor has low empty cavity losses, i.e., the empty cavity quality factor is >1500, then overall microwave discharge coupling efficiencies (η{sub coup}) of >94% can be achieved. A large, safe, and efficient experimental operating regime is identified. Both substrate hot spots and the formation of microwave plasmoids are eliminated when operating within this regime. This investigation suggests that both the reactor design and the reactor process operation must be considered when attempting to lower diamond synthesis electrical energy costs while still enabling a very versatile and flexible operation performance.

  3. Bone marrow transplant – children - discharge

    MedlinePlus

    Transplant - bone marrow - children - discharge; Stem cell transplant - children - discharge; Hematopoietic stem cell transplant -children - discharge; Reduced intensity, non-myeloablative transplant - children - discharge; Mini transplant - children - discharge; Allogenic ...

  4. Low Pressure Experimental Simulation of Electrical Discharges Above and Inside a Cloud

    NASA Technical Reports Server (NTRS)

    Jarzembski, Maurice A.; Srivastava, Vandana

    1996-01-01

    A low pressure laboratory experiment to generate sporadic electrical discharges in either a particulate dielectric or air, representing a competing path of preferred electrical breakdown, was investigated. At high pressures, discharges occurred inside the dielectric particulate; at low pressures, discharges occurred outside the dielectric particulate; at a transition pressure regime, which depends on conductivity of the dielectric particulate, discharges were simultaneously generated in both particulate dielectric and air. Unique use of a particulate dielectric was critical for sporadic discharges at lower pressures which were not identical in character to discharges without the particulate dielectric. Application of these experimental results to the field of atmospheric electricity and simulation of the above-cloud type discharges that have recently been documented, called jets and sprites, are discussed.

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

    PubMed

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

    2016-06-01

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

  6. Discharge effects on gas flow dynamics in a plasma jet

    NASA Astrophysics Data System (ADS)

    Xian, Yu Bin; Hasnain Qaisrani, M.; Yue, Yuan Fu; Lu, Xin Pei

    2016-10-01

    Plasma is used as a flow visualization method to display the gas flow of a plasma jet. Using this method, it is found that a discharge in a plasma jet promotes the transition of the gas flow to turbulence. A discharge at intermediate frequency (˜6 kHz in this paper) has a stronger influence on the gas flow than that at lower or higher frequencies. Also, a higher discharge voltage enhances the transition of the gas flow to turbulence. Analysis reveals that pressure modulation induced both by the periodically directed movement of ionized helium and Ohmic heating on the gas flow plays an important role in inducing the transition of the helium flow regime. In addition, since the modulations induced by the high- and low-frequency discharges are determined by the frequency-selective effect, only intermediate-frequency (˜6 kHz) discharges effectively cause the helium flow transition from the laminar to the turbulent flow. Moreover, a discharge with a higher applied voltage makes a stronger impact on the helium flow because it generates stronger modulations. These conclusions are useful in designing cold plasma jets and plasma torches. Moreover, the relationship between the discharge parameters and the gas flow dynamics is a useful reference on active flow control with plasma actuators.

  7. Recombinative plasma in electron runaway discharge

    SciTech Connect

    Kuznetsov, Yu.K.; Galvao, R.M.O.; Usuriaga, O.C.; Krasheninnikov, S.I.; Soboleva, T.K.; Tsypin, V.S.; Fonseca, A.M.M.; Ruchko, L.F.; Sanada, E.K.

    2005-07-15

    Cold recombinative plasma is the basic feature of the new regime of runaway discharges recently discovered in the Tokamak Chauffage Alfven Bresilien tokamak [R. M. O. Galvao et al., Plasma Phys. Controlled Fusion 43, 1181 (2001)]. With low plasma temperature, the resistive plasma current and primary Dreicer process of runaway generation are strongly suppressed at the stationary phase of the discharge. In this case, the runaway avalanche, which has been recently recognized as a novel important mechanism for runaway electron generation in large tokamaks, such as International Thermonuclear Experimental Reactor, during disruptions, and for electric breakdown in matter, is the only mechanism responsible for toroidal current generation and can be easily observed. The measurement of plasma temperature by the usual methods is a difficult task in fully runaway discharges. In the present work, various indirect evidences for low-temperature recombinative plasma are presented. The direct observation of recombinative plasma is obtained as plasma detachment from the limiter. The model of cold recombinative plasma is also supported by measurements of plasma density and H{sub {alpha}} emission radial profiles, analysis of time variations of these parameters due to the relaxation instability, estimations of plasma resistivity from voltage spikes, and energy and particle balance calculations.

  8. Demonstration of high performance negative central magnetic shear discharges on the DIII-D tokamak

    SciTech Connect

    Rice, B.W.; Burrell, K.H.; Lao, L.L.

    1996-01-01

    Reliable operation of discharges with negative central magnetic shear has led to significant increases in plasma performance and reactivity in both low confinement, L-mode, and high confinement, H-mode, regimes in the DIII-D tokamak. Using neutral beam injection early in the initial current ramp, a large range of negative shear discharges have been produced with durations lasting up to 3.2 s. The total non- inductive current (beam plus bootstrap) ranges from 50% to 80% in these discharges. In the region of shear reversal, significant peaking of the toroidal rotation [f{sub {phi}} {approx} 30-60 kHz] and ion temperature [T{sub i}(0) {approx} 15-22 keV] profiles are observed. In high power discharges with an L-mode edge, peaked density profiles are also observed. Confinement enhancement factors up to H {equivalent_to} {tau}{sub E}/{tau}{sub ITER-89P} {approx} 2.5 with an L-mode edge, and H {approx} 3.3 in an Edge Localized Mode (ELM)-free H-mode, are obtained. Transport analysis shows both ion thermal diffusivity and particle diffusivity to be near or below standard neoclassical values in the core. Large pressure peaking in L- mode leads to high disruptivity with {Beta}{sub N} {equivalent_to} {Beta}{sub T}/(I/aB) {<=} 2.3, while broader pressure profiles in H- mode gives low disruptivity with {Beta}{sub N} {<=} 4.2.

  9. Observed trends in the hydrologic regime of Alpine catchments

    NASA Astrophysics Data System (ADS)

    Bard, Antoine; Renard, Benjamin; Lang, Michel

    2010-05-01

    A European trans-national project, AdaptAlp, has been set up since 2008 in order to study the impacts of climate change in the Alps and to assess adaptation strategies. One of the objectives of this project is to study past and present changes in the hydrologic regime of Alpine rivers. This poster presents preliminary results of a trend analysis over the whole Alpine area. A new dataset of more than two hundred discharge time series has been collected over the six countries of the alpine space: Switzerland, Italy, Germany, Austria, Slovenia and France. These series are made up of at least forty years of daily record and are related to undisturbed catchments. This dataset covers the whole spectrum of hydrological regimes existing in the Alps (from glacier- to mixed rainfall/snow regimes). In a second step, a set of hydrologic indices has been defined to characterize the hydrologic regime in terms of low, medium and high flows. In particular, these indices describe the drought severity (in terms of duration, intensity and volume deficit) and seasonality, the volume and timing of snowmelt, floods intensity and seasonality. A statistical trend test is finally applied for each hydrologic indice at each site. Consistent trends affecting the timing of snowmelt-dominated streamflow are found all over the Alps. Spring floods appear earlier in the season and tend to be longer in duration. Winter droughts tend to be shorter and less severe in terms of volume deficit.

  10. Characterization of millimetre magnitude atmospheric pressure streamer discharge in pin-to-plane dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Xu, S. J.; Zhang, Y. H.; Yu, Z.; Yao, J.; Zhang, Z. T.

    2013-03-01

    The streamer regime of pin-to-plane dielectric barrier discharge in air was studied by means of fast photography, electrical measurement and photoelectricity. The fast photographs of positive streamer were obtained by CCD camera with micro lens. The exposure time is one microseconds. The images illustrate that the streamer is non-axisymmetric because of some random factors, such as surface charge position, space charge distribution, gas liquidity and so on. In fact, the streamer propagates along bend discharge channel. The bending degree increases with the electric field strengthen. By surveying a mass of images, the diameter of streamer, height of surface charge effect and scope of surface charge was estimate used to describe the shape of streamer.

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

    EPA Pesticide Factsheets

    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.

  12. Plasma regimes in high power pulsed magnetron sputtering

    NASA Astrophysics Data System (ADS)

    de Los Arcos, Teresa

    2013-09-01

    High Power Pulsed Magnetron Sputtering (HPPMS) is a relatively recent variation of magnetron sputtering where high power is applied to the magnetron in short pulses. The result is the formation of dense transient plasmas with a high fraction of ionized species, ideally leading to better control of film growth through substrate bias. However, the broad range of experimental conditions accessible in pulsed discharges results in bewildering variations in current and voltage pulse shapes, pulse power densities, etc, which represent different discharge behaviors, making it difficult to identify relevant deposition conditions. The complexity of the plasma dynamics is evident. Within each pulse, plasma characteristics such as plasma composition, density, gas rarefaction, spatial distribution, degree of self-sputtering, etc. vary with time. A recent development has been the discovery that the plasma emission can self-organize into well-defined regions of high and low plasma emissivity above the racetrack (spokes), which rotate in the direction given by the E ×B drift and that significantly influence the transport mechanisms in HPPMS. One seemingly universal characteristic of HPPMS plasmas is the existence of well defined plasma regimes for different power ranges. These regimes are clearly differentiated in terms of plasma conductivity, plasma composition and spatial plasma self-organization. We will discuss the global characteristics of these regimes in terms of current-voltage characteristics, energy-resolved QMS and OES analysis, and fast imaging. In particular we will discuss how the reorganization of the plasma emission into spokes is associated only to specific regimes of high plasma conductivity. We will also briefly discuss the role of the target in shaping the characteristics of the HPPMS plasma, since sputtering is a surface-driven process. This work was supported by the Deutsche Forschungsgemeinschaft (DFG) within the framework of the SFB-TR87.

  13. The transition mechanism from a symmetric single period discharge to a period-doubling discharge in atmospheric helium dielectric-barrier discharge

    SciTech Connect

    Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen

    2013-06-15

    Period-doubling and chaos phenomenon have been frequently observed in atmospheric-pressure dielectric-barrier discharges. However, how a normal single period discharge bifurcates into period-doubling state is still unclear. In this paper, by changing the driving frequency, we study numerically the transition mechanisms from a normal single period discharge to a period-doubling state using a one-dimensional self-consistent fluid model. The results show that before a discharge bifurcates into a period-doubling state, it first deviates from its normal operation and transforms into an asymmetric single period discharge mode. Then the weaker discharge in this asymmetric discharge will be enhanced gradually with increasing of the frequency until it makes the subsequent discharge weaken and results in the discharge entering a period-doubling state. In the whole transition process, the spatial distribution of the charged particle density and the electric field plays a definitive role. The conclusions are further confirmed by changing the gap width and the amplitude of the applied voltage.

  14. GASEOUS DISCHARGE DEVICE

    DOEpatents

    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)

  15. Magnetic dipole discharges. I. Basic properties

    SciTech Connect

    Stenzel, R. L.; Urrutia, J. M.; Teodorescu-Soare, C. T.; Ionita, C.; Schrittwieser, R.

    2013-08-15

    A simple discharge is described which uses a permanent magnet as a cold cathode and the metallic chamber wall as an anode. The magnet's equator is biased strongly negative, which produces secondary electrons due to the impact of energetic ions. The emitted electrons are highly confined by the strong dipolar magnetic field and the negative potential in the equatorial plane of the magnet. The emitted electrons ionize near the sheath and produce further electrons, which drift across field lines to the anode while the nearly unmagnetized ions are accelerated back to the magnet. A steady state discharge is maintained at neutral pressures above 10{sup −3} mbar. This is the principle of magnetron discharges, which commonly use cylindrical and planar cathodes rather than magnetic dipoles as cathodes. The discharge properties have been investigated in steady state and pulsed mode. Different magnets and geometries have been employed. The role of a background plasma has been investigated. Various types of instabilities have been observed such as sheath oscillations, current-driven turbulence, relaxation instabilities due to ionization, and high frequency oscillations created by sputtering impulses, which are described in more detail in companion papers. The discharge has also been operated in reactive gases and shown to be useful for sputtering applications.

  16. Electric-discharge-pumped nitrogen ion laser

    NASA Technical Reports Server (NTRS)

    Laudenslager, J. B.; Pacala, T. J.; Wittig, C.

    1976-01-01

    The routine operation is described of an N2(+) laser oscillating on the first negative band system of N2(+) which is produced in a preionized transverse discharge device. The discharge design incorporates features which favor the efficient production of the excitation transfer reaction of He2(+) with N2. A capacitive discharge switched by means of a high-current grounded grid thyratron is used to meet the design requirement of a volumetric discharge in high-pressure gas mixtures where the electric discharge need not have an ultrafast rise time (greater than 10 nsec) but should be capable of transferring large quantities of stored electric energy to the gas. A peak power of 180 kW in an 8-nsec laser pulse was obtained with a 0.1% mixture of N2 in helium at a total pressure of 3 atm. The most intense laser oscillations were observed on the (0,1) vibrational transition at 427.8 microns.

  17. Electrostatic discharge test apparatus

    NASA Technical Reports Server (NTRS)

    Smith, William Conrad (Inventor)

    1988-01-01

    Electrostatic discharge properties of materials are quantitatively measured and ranked. Samples are rotated on a turntable beneath selectable, co-available electrostatic chargers, one being a corona charging element and the other a sample-engaging triboelectric charging element. Samples then pass under a voltage meter to measure the amount of residual charge on the samples. After charging is discontinued, measurements are continued to record the charge decay history over time.

  18. Deterministic-random separation in nonstationary regime

    NASA Astrophysics Data System (ADS)

    Abboud, D.; Antoni, J.; Sieg-Zieba, S.; Eltabach, M.

    2016-02-01

    In rotating machinery vibration analysis, the synchronous average is perhaps the most widely used technique for extracting periodic components. Periodic components are typically related to gear vibrations, misalignments, unbalances, blade rotations, reciprocating forces, etc. Their separation from other random components is essential in vibration-based diagnosis in order to discriminate useful information from masking noise. However, synchronous averaging theoretically requires the machine to operate under stationary regime (i.e. the related vibration signals are cyclostationary) and is otherwise jeopardized by the presence of amplitude and phase modulations. A first object of this paper is to investigate the nature of the nonstationarity induced by the response of a linear time-invariant system subjected to speed varying excitation. For this purpose, the concept of a cyclo-non-stationary signal is introduced, which extends the class of cyclostationary signals to speed-varying regimes. Next, a "generalized synchronous average'' is designed to extract the deterministic part of a cyclo-non-stationary vibration signal-i.e. the analog of the periodic part of a cyclostationary signal. Two estimators of the GSA have been proposed. The first one returns the synchronous average of the signal at predefined discrete operating speeds. A brief statistical study of it is performed, aiming to provide the user with confidence intervals that reflect the "quality" of the estimator according to the SNR and the estimated speed. The second estimator returns a smoothed version of the former by enforcing continuity over the speed axis. It helps to reconstruct the deterministic component by tracking a specific trajectory dictated by the speed profile (assumed to be known a priori).The proposed method is validated first on synthetic signals and then on actual industrial signals. The usefulness of the approach is demonstrated on envelope-based diagnosis of bearings in variable

  19. Modeling electronegative plasma discharge

    SciTech Connect

    Lichtenberg, A.J.; Lieberman, M.A.

    1995-12-31

    Macroscopic analytic models for a three-component electronegative gas discharge are developed. Assuming the negative ions to be in Boltzmann equilibrium, a positive ion ambipolar diffusion equation is derived. The discharge consists of an electronegative core and electropositive edges. The electron density in the core is nearly uniform, allowing a parabolic approximation to the plasma profile to be employed. The resulting equilibrium equations are solved analytically and matched to a constant mobility transport model of an electropositive edge plasma. The solutions are compared to a simulation of a parallel-plane r.f. driven oxygen plasma for p = 50 mTorr and n{sub eo}= 2.4 x 10{sup 15} m{sup -3}. The ratio {alpha}{sub o} of central negative ion density to electron density, and the electron temperature T{sub e}, found in the simulation, are in reasonable agreement with the values calculated from the model. The model is extended to: (1) low pressures, where a variable mobility model is used in the electropositive edge region; and (2) high {alpha}{sub o} in which the edge region disappears. The inclusion of a second positive ion species, which can be very important in describing electronegative discharges used for materials processing, is a possible extension of the model.

  20. Powerful glow discharge excilamp

    DOEpatents

    Tarasenko, Victor F.; Panchenko, Aleksey N.; Skakun, Victor S.; Sosnin, Edward A.; Wang, Francis T.; Myers, Booth R.; Adamson, Martyn G.

    2002-01-01

    A powerful glow discharge lamp comprising two coaxial tubes, the outer tube being optically transparent, with a cathode and anode placed at opposite ends of the tubes, the space between the tubes being filled with working gas. The electrodes are made as cylindrical tumblers placed in line to one other in such a way that one end of the cathode is inserted into the inner tube, one end of the anode coaxially covers the end of the outer tube, the inner tube penetrating and extending through the anode. The increased electrodes' surface area increases glow discharge electron current and, correspondingly, average radiation power of discharge plasma. The inner tube contains at least one cooling liquid tube placed along the axis of the inner tube along the entire lamp length to provide cathode cooling. The anode has a circumferential heat extracting radiator which removes heat from the anode. The invention is related to lighting engineering and can be applied for realization of photostimulated processes under the action of powerful radiation in required spectral range.

  1. Regime Change the Old Fashioned Way: US Support to Insurgencies

    DTIC Science & Technology

    2008-04-23

    attributed the failure to poor direction and coordination, and created a special structure to oversee Operation MONGOOSE , a second covert program...against the Castro regime in Cuba. To ensure unity of effort, Kennedy designated Brigadier General Edward Lansdale in writing as the 7 MONGOOSE

  2. Effects of flow regime on stream turbidity and suspended solids after wildfire, Colorado Front Range

    USGS Publications Warehouse

    Murphy, Sheila F.; McCleskey, R. Blaine; Writer, Jeffrey H.

    2012-01-01

    Wildfires occur frequently in the Colorado Front Range and can alter the hydrological response of watersheds, yet little information exists on the impact of flow regime and storm events on post-wildfire water quality. The flow regime in the region is characterized by base-flow conditions during much of the year and increased runoff during spring snowmelt and summer convective storms. The impact of snowmelt and storm events on stream discharge and water quality was evaluated for about a year after a wildfire near Boulder, Colorado, USA. During spring snowmelt and low-intensity storms, differences in discharge and turbidity at sites upstream and downstream from the burned areas were minimal. However, high-intensity convective storms resulted in dramatic increases in discharge and turbidity at sites downstream from the burned area. This study highlights the importance of using high-frequency sampling to assess accurately wildfire impacts on water quality downstream.

  3. Physics and Chemistry of MW Discharge in Gas Flows

    DTIC Science & Technology

    2007-11-02

    this working regime of wind tunnel. Measurement was carried out by means of pneumatic probes. 1.1.1. Experimental conditions Nozzle with Mach number 2.1...unstable objects may be Laser Thomson Scattering Technique. Created laser Thomson Final Report 30 July, 2004 Project 2014p IHT-SPSU scattering...experimental scheme for investigation of Thomson scattering in MW discharge in SS flow with static pressure 20 - 50 Torr and Mach number 1.5 - 2. Impulse

  4. Equatorial atmospheric weather regimes: Their structure and role

    SciTech Connect

    Connors, V.S.

    1991-01-01

    Infrared radiance measurements by the Geostationary Operational Environmental Satellite (GOES-6) from April 1986 through April 1987 are used to characterize and identify distinct regimes of persistent, large-scale cloudiness patterns over the Amazon Basin. These tropical weather regimes are responsible for the continental-scale atmospheric processes that transport air, trace gases, and heat from the Amazon Basin. The cloud patterns are represented by both scene-scale parameters, such as the cloud-free area and the value of the 'clear sky peak' in a histogram, and textural measures, such as contrast of cloudy area and homogeneity or cloudy area. Correlation analyses of the attribute arrays determined that only 9 of the original 15 cloud pattern descriptors are required for the cluster analyses. Seventy-six percent of the satellite images are classified into 1 of 14 weather regimes which persist for periods that range from 3 to 15 days each. The dominant weather regimes are described by the recurrence and duration of the events, by the rainfall produced and energy released to the tropical atmosphere, and by the composite kinematic and thermodynamic analyses. While the classification analyses identified a range of organized weather conditions in the Amazon Basin, two weather regimes, each occurring in separate seasons, dominate the year. The prominent dry season regime (A) occurs 11 times, persists for 25 percent of the year, produces 81 percent of the dry season rainfall, and 7 percent of the energy export necessary to balance the global heat budget. The prominent wet season regime (B) occurs 8 times, persists for 18 percent of the year, delivers about 30 percent of the wet season rainfall, and 16 percent of the energy export requirement. Because the dry season regime (A) draws nearly half of its water vapor supply from local sources, a vital link may exist between the rainforest ecosystem and the dry season rainfall.

  5. Hall effect in hopping regime

    NASA Astrophysics Data System (ADS)

    Avdonin, A.; Skupiński, P.; Grasza, K.

    2016-02-01

    A simple description of the Hall effect in the hopping regime of conductivity in semiconductors is presented. Expressions for the Hall coefficient and Hall mobility are derived by considering averaged equilibrium electron transport in a single triangle of localization sites in a magnetic field. Dependence of the Hall coefficient is analyzed in a wide range of temperature and magnetic field values. Our theoretical result is applied to our experimental data on temperature dependence of Hall effect and Hall mobility in ZnO.

  6. Detecting spatial regimes in ecosystems

    USGS Publications Warehouse

    Sundstrom, Shana M.; Eason, Tarsha; Nelson, R. John; Angeler, David G.; Barichievy, Chris; Garmestani, Ahjond S.; Graham, Nicholas A.J.; Granholm, Dean; Gunderson, Lance; Knutson, Melinda; Nash, Kirsty L.; Spanbauer, Trisha; Stow, Craig A.; Allen, Craig R.

    2017-01-01

    Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory-based method, on both terrestrial and aquatic animal data (U.S. Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps and multivariate analyses such as nMDS and cluster analysis. We successfully detected spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change.

  7. Discharge measurements at gaging stations

    USGS Publications Warehouse

    Buchanan, Thomas J.; Somers, William P.

    1969-01-01

    The techniques used in making discharge measurements at gaging stations are described in this report. Most of the report deals with the current-meter method of measuring discharge, because this is the principal method used in gaging streams. The use of portable weirs and flumes, floats, and volumetric tanks in measuring discharge are briefly described.

  8. Foot amputation - discharge

    MedlinePlus

    ... the foot. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; ... of amputations. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; ...

  9. Plasma Discharge Process in a Pulsed Diaphragm Discharge System

    NASA Astrophysics Data System (ADS)

    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.

  10. A comparison between micro hollow cathode discharges and atmospheric pressure plasma jets in Ar/O2 gas mixtures

    NASA Astrophysics Data System (ADS)

    Lazzaroni, C.; Chabert, P.

    2016-12-01

    Using global models, micro hollow cathode discharges (MHCDs) are compared to radiofrequency atmospheric pressure plasma jets (APPJs) in terms of reactive oxygen species (ROS) production. Ar/O2 gas mixtures are investigated, typically with a small percentage of oxygen in argon. The same chemical reaction set, involving 17 species and 128 chemical reactions in the gas phase, is used for both devices, operated in the typical geometries previously published; the APPJ is driven by a radiofrequency voltage across a 1 mm gap, at atmospheric pressure, while the MHCD is driven by a DC voltage source, at 100 Torr and in a 400 μm hole. The MHCD may be operated either in the self-pulsing or in the normal (stationary) regime, depending on the driving voltage. The comparison shows that in both regimes, the MHCD produces larger amounts of \\text{O}2\\ast , while the APPJ produces predominantly reactive oxygen ground state species, \\text{O} and {{\\text{O}}3} . These large differences in ROS composition are mostly due to the higher plasma density produced in the MHCD. The difference in operating pressure is a second order effect.

  11. Influence of the anode processes on discharges driven by thermionic emission

    SciTech Connect

    Levko, Dmitry

    2015-07-15

    The influence of electron reflection and secondary electron emission due to electron impact from the anode on discharges driven by thermionic emission is studied by the self-consistent one-dimensional particle-in-cell Monte Carlo collisions model. Two regimes are considered. In the first regime, the two-stream instability is excited and large anode sheath potential is obtained. It is found that in this regime, the reflected electrons play a significant role. In the second regime, the instability is not excited and the anode sheath potential is small. The dominant anode process in this regime is the secondary electron emission. It is shown that in both regimes, the anode processes significantly influence the plasma parameters.

  12. 77 FR 44494 - National Pollutant Discharge Elimination System Permit Regulation for Concentrated Animal Feeding...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... for Concentrated Animal Feeding Operations: Removal of Vacated Elements in Response to 2011 Court... Feeding Operation (CAFO) that ``proposes to discharge'' must apply for a National Pollutant Discharge... Feeding Operations in Response to the Waterkeeper Decision,'' (the 2008 CAFO Rule). DATES: This final...

  13. Charge transferred in brush discharges

    NASA Astrophysics Data System (ADS)

    Talarek, M.; Kacprzyk, R.

    2015-10-01

    Electrostatic discharges from surfaces of plastic materials can be a source of ignition, when appear in explosive atmospheres. Incendivity of electrostatic discharges can be estimated using the transferred charge test. In the case of brush discharges not all the energy stored at the tested sample is released and the effective surface charge density (or surface potential) crater is observed after the discharge. Simplified model, enabling calculation of a charge transferred during electrostatic brush discharge, was presented. Comparison of the results obtained from the simplified model and from direct measurements of transferred charge are presented in the paper.

  14. Compact Intracloud Discharges

    SciTech Connect

    Smith, David A.

    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

  15. Compact intracloud discharges

    NASA Astrophysics Data System (ADS)

    Smith, David Adam

    In November of 1993, mysterious signals recorded by a satellite-borne broadband VHF radio science experiment called Blackbeard led to a completely unexpected discovery. Prior to launch of the ALEXIS satellite, it was thought that its secondary payload, Blackbeard, 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 Blackbeard observations. On two occasions, the ground-based systems and Blackbeard even recorded emissions that were produced by the same exact events. From the ground-based observations, it has been determined that TIPP events are produced 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

  16. Effects of hydrologic infrastructure on flow regimes of California's Central Valley rivers: Implications for fish populations

    USGS Publications Warehouse

    Brown, Larry R.; Bauer, Marissa L.

    2010-01-01

    Alteration of natural flow regimes is generally acknowledged to have negative effects on native biota; however, methods for defining ecologically appropriate flow regimes in managed river systems are only beginning to be developed. Understanding how past and present water management has affected rivers is an important part of developing such tools. In this paper, we evaluate how existing hydrologic infrastructure and management affect streamflow characteristics of rivers in the Central Valley, California and discuss those characteristics in the context of habitat requirements of native and alien fishes. We evaluated the effects of water management by comparing observed discharges with estimated discharges assuming no water management ("full natural runoff"). Rivers in the Sacramento River drainage were characterized by reduced winter–spring discharges and augmented discharges in other months. Rivers in the San Joaquin River drainage were characterized by reduced discharges in all months but particularly in winter and spring. Two largely unaltered streams had hydrographs similar to those based on full natural runoff of the regulated rivers. The reduced discharges in the San Joaquin River drainage streams are favourable for spawning of many alien species, which is consistent with observed patterns of fish distribution and abundance in the Central Valley. However, other factors, such as water temperature, are also important to the relative success of native and alien resident fishes. As water management changes in response to climate change and societal demands, interdisciplinary programs of research and monitoring will be essential for anticipating effects on fishes and to avoid unanticipated ecological outcomes.

  17. Continuous pile discharging machine

    DOEpatents

    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.

  18. Radiation transport in kinetic simulations and the influence of photoemission on electron current in self-sustaining discharges

    NASA Astrophysics Data System (ADS)

    Fierro, Andrew; Moore, Chris; Scheiner, Brett; Yee, Benjamin T.; Hopkins, Matthew M.

    2017-02-01

    A kinetic description for electronic excitation of helium for principal quantum number n ≤slant 4 has been included into a particle-in-cell (PIC) simulation utilizing direct simulation Monte Carlo (DSMC) for electron-neutral interactions. The excited electronic levels radiate state-dependent photons with wavelengths from the extreme ultraviolet (EUV) to visible regimes. Photon wavelengths are chosen according to a Voigt distribution accounting for the natural, pressure, and Doppler broadened linewidths. This method allows for reconstruction of the emission spectrum for a non-thermalized electron energy distribution function (EEDF) and investigation of high energy photon effects on surfaces, specifically photoemission. A parallel plate discharge with a fixed field (i.e. space charge neglected) is used to investigate the effects of including photoemission for a Townsend discharge. When operating at a voltage near the self-sustaining discharge threshold, it is observed that the electron current into the anode is higher when including photoemission from the cathode than without even when accounting for self-absorption from ground state atoms. The photocurrent has been observed to account for as much as 20% of the total current from the cathode under steady-state conditions.

  19. Radiation transport in kinetic simulations and the influence of photoemission on electron current in self-sustaining discharges

    DOE PAGES

    Fierro, Andrew S.; Moore, Christopher Hudson; Scheiner, Brett; ...

    2017-01-12

    A kinetic description for electronic excitation of helium for principal quantum number nmore » $$\\leqslant $$ 4 has been included into a particle-in-cell (PIC) simulation utilizing direct simulation Monte Carlo (DSMC) for electron-neutral interactions. The excited electronic levels radiate state-dependent photons with wavelengths from the extreme ultraviolet (EUV) to visible regimes. Photon wavelengths are chosen according to a Voigt distribution accounting for the natural, pressure, and Doppler broadened linewidths. This method allows for reconstruction of the emission spectrum for a non-thermalized electron energy distribution function (EEDF) and investigation of high energy photon effects on surfaces, specifically photoemission. A parallel plate discharge with a fixed field (i.e. space charge neglected) is used to investigate the effects of including photoemission for a Townsend discharge. When operating at a voltage near the self-sustaining discharge threshold, it is observed that the electron current into the anode is higher when including photoemission from the cathode than without even when accounting for self-absorption from ground state atoms. As a result, the photocurrent has been observed to account for as much as 20% of the total current from the cathode under steady-state conditions.« less

  20. Modelling Of Chlorine Inductive Discharges

    NASA Astrophysics Data System (ADS)

    Chabert P.; Despiau-Pujo, E.

    2010-07-01

    III-V compounds such as GaAs, InP or GaN-based materials are increasingly important for their use in optoelectronic applications, especially in the telecommunications and light detection industries. Photonic devices including lasers, photodetectors or LEDs, require reliable etching processes characterized by high etch rate, profile control and low damage. Although many problems remain to be understood, inductively coupled discharges seem to be promising to etch such materials, using Cl2/Ar, Cl2/N2 and Cl2/H2 gas chemistries. Inductively coupled plasma (ICP) sources meet most of the requirements for efficient plasma processing such as high etch rates, high ion densities and low controllable ion energies. However, the presence of a negative ion population in the plasma alters the positive ion flux, reduces the electron density, changes the electron temperature, modifies the spatial structure of the discharge and can cause unstable operation. Several experimental studies and numerical simulation results have been published on inductively coupled Cl2/Ar plasmas but relatively few systematic comparisons of model predictions and experimental data have been reported in given reactor geometries under a wide range of op- erating conditions. Validation of numerical predictions is essential for chemically complex plasma processing and there is a need to benchmark the models with as many measurements as possible. In this paper, comparisons of 2D fluid simulations with experimental measurements of Ar/Cl2 plasmas in a low pressure ICP reactor are reported (Corr et al. 2008). The electron density, negative ion fraction and Cl atom density are investigated for various conditions of Ar/Cl2 ratio, gas pressure and applied RF power in H mode. Simulations show that the wall recombination coefficient of Cl atom (?) is a key parameter of the model and that neutral densities are very sensitive to its variations. The best agreement between model and experiment is obtained for ? = 0

  1. 33 CFR 157.37 - Discharge of oily mixtures from oil cargoes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Discharge of oily mixtures from... CARRYING OIL IN BULK Vessel Operation § 157.37 Discharge of oily mixtures from oil cargoes. (a) A tank vessel may not discharge an oily mixture into the sea from a cargo tank, slop tank, or cargo pump...

  2. 33 CFR 157.37 - Discharge of oily mixtures from oil cargoes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Discharge of oily mixtures from... CARRYING OIL IN BULK Vessel Operation § 157.37 Discharge of oily mixtures from oil cargoes. (a) A tank vessel may not discharge an oily mixture into the sea from a cargo tank, slop tank, or cargo pump...

  3. 33 CFR 157.37 - Discharge of oily mixtures from oil cargoes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Discharge of oily mixtures from... CARRYING OIL IN BULK Vessel Operation § 157.37 Discharge of oily mixtures from oil cargoes. (a) A tank vessel may not discharge an oily mixture into the sea from a cargo tank, slop tank, or cargo pump...

  4. 33 CFR 157.37 - Discharge of oily mixtures from oil cargoes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Discharge of oily mixtures from... CARRYING OIL IN BULK Vessel Operation § 157.37 Discharge of oily mixtures from oil cargoes. (a) A tank vessel may not discharge an oily mixture into the sea from a cargo tank, slop tank, or cargo pump...

  5. 33 CFR 157.37 - Discharge of oily mixtures from oil cargoes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Discharge of oily mixtures from... CARRYING OIL IN BULK Vessel Operation § 157.37 Discharge of oily mixtures from oil cargoes. (a) A tank vessel may not discharge an oily mixture into the sea from a cargo tank, slop tank, or cargo pump...

  6. Discharge data at water-quality monitoring stations in Arkansas, 1980 water year

    USGS Publications Warehouse

    Knott, R.K.

    1981-01-01

    Discharge data were computed for a network of water-quality monitoring stations operated by the Arkansas Department of Pollution Control and Ecology. Some of the sites are located at U.S. Geological Survey of U.S. Army Corps of Engineers daily-discharge stations, but most sites are at points where discharges are not regularly measured. (USGS)

  7. Discharge data at water-quality monitoring stations in Arkansas, 1977 water year

    USGS Publications Warehouse

    Knott, R.K.

    1978-01-01

    Discharge data were computed for a network of water-quality monitoring stations operated by the Arkansas Department of Pollution Control and Ecology. Some of the sites are located at U.S. Geological Survey or U.S. Army Corps of Engineers daily-discharge stations, but most are at points where discharges are not measured regularly. (Woodard-USGS)

  8. Instabilities in Inductive Discharges with Electronegative Gases

    DTIC Science & Technology

    2003-07-20

    electronegative gases P. Chabert, H . Abada , and J.-P. Booth LPTP, Ecole Polytechnique, 91128 Palaiseau cedex, France A.J. Lichtenberg, M.A. Lieberman, A. M...can exist in two inductive discharge modes: the capacitive (E) mode, for low power, and the g00 inductive ( H ) mode, for high power. As the power is -1...increased, transitions from capacitive to inductive modes D00 (E- H transitions) are observed [7,8]. When operating with Q. electropositive gases the

  9. Culvert analysis program for indirect measurement of discharge

    USGS Publications Warehouse

    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.

  10. Plasma physics issues in gas discharge laser development

    SciTech Connect

    Garscadden, A. ); Kushner, M.J.; Eden, J.G. . Dept. of Electrical and Computer Engineering)

    1991-12-01

    In this paper an account is given of the interplay between partially ionized plasma physics and the development of gas discharge lasers. Gas discharge excitation has provided a wide array of laser devices extending from the soft X-ray region to the far infrared. The scaling of gas discharge lasers in power and energy also covers many orders of magnitude. The particular features of three regimes are discussed: short wavelength lasers (deep UV to soft X-ray); visible and near UV lasers; and infrared molecular gas lasers. The current status (Fall 1990) of these areas is reviewed, and an assessment is made of future research topics that are perceived to be important.

  11. Long slide-away discharges in the COMPASS tokamak

    NASA Astrophysics Data System (ADS)

    Ficker, Ondrej; Mlynar, Jan; Vlainic, Milos; Weinzettl, Vladimir; Urban, Jakub; Cavalier, Jordan; Havlicek, Jaroslav; Panek, Radomir; Hron, Martin; Cerovsky, Jaroslav; Vondracek, Petr; Paprok, Richard; Decker, Joan; Peysson, Yves; Bogar, Ondrej; Stahl, Adam; Compass Team

    2016-10-01

    In this contribution, long runaway electron (RE) dominated discharges achieved in the COMPASS tokamak are presented. The extensive length is possible due to a low consumption of available volt-seconds of the tokamak transformer in this type of discharge. Energetic electron losses in this regime seems to be modulated mainly by small oscillations of a radial position (controller setting) unlike in the RE discharges at higher electron density, where various MHD phenomena affect the evolution of the losses. The behaviour of the slide-away plasma is studied using magnetic coils, HXR detectors, ECE system and a pair of 3He proportional counters of neutrons. The plasma scenario is also modelled using Fokker-Planck codes. EUROfusion WP MST1, MST2.

  12. The Nonlinear Behaviors in Atmospheric Dielectric Barrier Multi Pulse Discharges

    NASA Astrophysics Data System (ADS)

    Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen

    2016-08-01

    An in-depth and comprehensive understanding of the complex nonlinear behaviors in atmospheric dielectric barrier discharge is significant for the stable operation and effective control of the plasma. In this paper, we study the nonlinear behaviors in argon atmospheric dielectric barrier multi pulse discharges by a one-dimensional fluid model. Under certain conditions, the multi pulse discharge becomes very sensitive with the increase of frequency, and the multi pulse period-doubling bifurcation, inverse period-doubling bifurcation and chaos appear frequently. The discharge can reach a relatively steady state only when the discharges are symmetrical between positive and negative half cycle. In addition, the effects of the voltage on these nonlinear discharges are also studied. It is found that the amplitude of voltage has no effects on the number of discharge pulses in multi-pulse period-doubling bifurcation sequences; however, to a relatively stable periodic discharge, the discharge pulses are proportional to the amplitude of the applied voltage within a certain range. supported by National Natural Science Foundation of China (No. 11447244), the Science Foundation of Hengyang Normal University of China (No. 14B41), the Construct Program of the Key Discipline in Hunan Province, and the Hunan Provincial Applied Basic Research Base of Optoelectronic Information Technology of China (No. GDXX010)

  13. Properties of corona discharge in a hot chamber

    SciTech Connect

    Uhm, H.S.

    1999-07-01

    The corona discharge system has been studied lately for its potential application to reduce NO{sub x} and SO{sub x} gas emission, where high electrical voltage (typically 50 kV) is applied to electrodes, inducing electrical breakdown in an atmospheric pressure and generating a plasma volume. One of the important issues in the corona discharge system is an effective generation of plasmas in the system. The electrical power needed for the plasma generation is one of the main operating costs of the corona discharge system. Less power consumption for plasma generation makes the corona discharge system more economical. Air pollutants are very often emitted from hot chambers such as municipal incinerators or electric power plants. It is therefore necessary to investigate influence of the chamber temperature on properties of the corona discharge system. From present work, the authors found that the critical voltage V{sub c} required for the corona-discharge breakdown is inversely proportional to the chamber temperature T. The electrical energy w{sub c} required for corona-discharge breakdown is inversely proportional to the square of the chamber temperature T. Thus, the electrical energy consumption for corona-discharge system decreases significantly as the temperature increases. The plasma generation by corona discharge in a hot chamber is much more efficient than that in a cold chamber.

  14. Experimental investigations of electron heating dynamics and ion energy distributions in capacitive discharges driven by customized voltage waveforms

    SciTech Connect

    Berger, Birk; Brandt, Steven; Franek, James; Schüngel, Edmund; Koepke, Mark; Schulze, Julian; Mussenbrock, Thomas

    2015-12-14

    Capacitively coupled radio frequency plasmas driven by customized voltage waveforms provide enhanced opportunities to control process-relevant energy distributions of different particle species. Here, we present an experimental investigation of the spatio-temporal electron heating dynamics probed by Phase-Resolved Optical Emission Spectroscopy (PROES) in an argon discharge driven by up to three consecutive harmonics of 13.56 MHz with individually adjustable harmonics' amplitudes and phases. PROES and voltage measurements are performed at fixed total voltage amplitudes as a function of the number of driving harmonics, their relative phases, and pressure to study the effects of changing the applied voltage waveform on the heating dynamics in collisionless and collisional regimes. Additionally, the ion energy distribution function (IEDF) is measured at low pressure. In this collisionless regime, the discharge is operated in the α-mode. The velocity of energetic electron beams generated by the expanding sheaths is found to be affected by the number of driving harmonics and their relative phases. This is understood based on the sheath dynamics obtained from a model that determines sheath voltage waveforms. The formation of the measured IEDFs is understood and found to be directly affected by the observed changes in the electron heating dynamics. It is demonstrated that the mean ion energy can be controlled by adjusting the harmonics' phases. In the collisional regime at higher pressures changing the number of harmonics and their phases at fixed voltage is found to induce heating mode transitions from the α- to the γ-mode. Finally, a method to use PROES as a non-invasive diagnostic to monitor and detect changes of the ion flux to the electrodes is developed.

  15. Flow regimes during immiscible displacement

    DOE PAGES

    Armstrong, Ryan T.; Mcclure, James; Berrill, Mark A.; ...

    2017-02-01

    Fractional ow of immiscible phases occurs at the pore scale where grain surfaces and phases interfaces obstruct phase mobility. However, the larger scale behavior is described by a saturation-dependent phenomenological relationship called relative permeability. As a consequence, pore-scale parameters, such as phase topology and/ or geometry, and details of the flow regime cannot be directly related to Darcy-scale flow parameters. It is well understood that relative permeability is not a unique relationship of wetting-phase saturation and rather depends on the experimental conditions at which it is measured. Herein we use fast X-ray microcomputed tomography to image pore-scale phase arrangements duringmore » fractional flow and then forward simulate the flow regimes using the lattice-Boltzmann method to better understand the underlying pore-scale flow regimes and their influence on Darcy-scale parameters. We find that relative permeability is highly dependent on capillary number and that the Corey model fits the observed trends. At the pore scale, while phase topologies are continuously changing on the scale of individual pores, the Euler characteristic of the nonwetting phase (NWP) averaged over a sufficiently large field of view can describe the bulk topological characteristics; the Euler characteristic decreases with increasing capillary number resulting in an increase in relative permeability. Lastly, we quantify the fraction of NWP that flows through disconnected ganglion dynamics and demonstrate that this can be a significant fraction of the NWP flux for intermediate wetting-phase saturation. Furthermore, rate dependencies occur in our homogenous sample (without capillary end effect) and the underlying cause is attributed to ganglion flow that can significantly influence phase topology during the fractional flow of immiscible phases.« less

  16. Studies of corona and back discharges in carbon dioxide

    NASA Astrophysics Data System (ADS)

    Czech, Tadeusz; Sobczyk, Arkadiusz Tomasz; Jaworek, Anatol; Krupa, Andrzej; Rajch, Eryk

    2013-01-01

    unwanted inception, decreases the energy and collection efficiencies of electrostatic precipitator. The second reason behind these studies is that CO2 is the main component of flue gas leaving oxyfuel boiler that re-circulates in the combustion-precipitation cycle. It was shown that discharges in CO2 lead to contamination of discharge electrode with carbonaceous products that can cause severe maintenance problems of electrostatic precipitator. The recognition of the characteristics of electrostatic precipitator operating in the oxyfuel system is, therefore, of crucial importance for exhaust gas cleaning in modern combustion systems.

  17. Overview of the regimes: CWC

    SciTech Connect

    1995-12-31

    The Chemical Weapons Convention`s (CWC) seeks to eradicate an entire category of catastrophic weapons and to ensure their continued non-production. Unlike the Non-Proliferation Treaty`s (NPT), the CWC requires disarmament. States Parties having chemical weapons (CW) must destroy them. The CWC has not adopted the NPT distinction between weapons and non-weapons states; the CWC`s prohibitions and obligations will apply identically to all States parties. In most other respects, the two treaties establish similar regimes with similar approaches. Included are objectives and primary obligations, legal bases, institutional oversight, trade restrictions, protection of information, penal consequences, and role of the United Nations.

  18. Frequency dependence of microparticle charge in a radio frequency discharge with Margenau electron velocity distribution

    SciTech Connect

    Du, Cheng-Ran; Khrapak, Sergey A.; Antonova, Tetyana; Steffes, Bernd; Thomas, Hubertus M.; Morfill, Gregor E.

    2011-01-15

    rf discharges are widely used in complex plasma experiments. In this paper, we theoretically investigate the dependence of the particle floating potential on the discharge frequency, assuming the model Margenau expression for the electron velocity distribution function. In doing so we use the orbital motion limited cross section to calculate the electron flux to the particle and collision enhanced collection approximation for the ion flux to the particle. The floating potential is then obtained from the flux balance condition. It is shown that for typical plasma conditions in laboratory rf discharges, normalized floating potential grows with increase of the discharge frequency in collisionless regime and decreases in weakly collisional regime. However, variations in the floating potential are usually small when plasma parameters do not depend on the rf frequency.

  19. Flow Regime Identification of Horizontal Two Phase Refrigerant R-134a Flow Using Neural Networks (Postprint)

    DTIC Science & Technology

    2013-11-01

    state operation of the channel. Measurement and detection of changes in flow regime improve thermal management system modeling efforts. Historically...identification and classification of horizontal two-phase flow regimes relies on human interpretation of measured signals. Variations in flow...Tomography (ECT) is a non-invasive impedance measurement method that produces mean normalized permittivity ratio, ̅, values that are directly linked

  20. Large discharge-volume, silent discharge spark plug

    DOEpatents

    Kang, Michael

    1995-01-01

    A large discharge-volume spark plug for providing self-limiting microdischarges. The apparatus includes a generally spark plug-shaped arrangement of a pair of electrodes, where either of the two coaxial electrodes is substantially shielded by a dielectric barrier from a direct discharge from the other electrode, the unshielded electrode and the dielectric barrier forming an annular volume in which self-terminating microdischarges occur when alternating high voltage is applied to the center electrode. The large area over which the discharges occur, and the large number of possible discharges within the period of an engine cycle, make the present silent discharge plasma spark plug suitable for use as an ignition source for engines. In the situation, where a single discharge is effective in causing ignition of the combustible gases, a conventional single-polarity, single-pulse, spark plug voltage supply may be used.

  1. Effects of a diversion hydropower facility on the hydrological regime of the Correntes River, a tributary to the Pantanal floodplain, Brazil

    NASA Astrophysics Data System (ADS)

    Fantin-Cruz, Ibraim; Pedrollo, Olavo; Girard, Pierre; Zeilhofer, Peter; Hamilton, Stephen K.

    2015-12-01

    Facilities that produce hydroelectricity by diversion of part of the river's flow, which are often considered to have lower environmental impact than conventional hydropower dams, are being built in large numbers on river systems throughout the world, yet their cumulative impacts are not well understood. This study evaluated the hydrological effects of operation of a diversion hydropower facility on the Correntes River in Brazil (mean discharge 73 m3 s-1), which is potentially important because of the ecological implications for the floodplains of the Pantanal into which it flows. Many similar dams are built or proposed on rivers feeding the Pantanal. The 210-MW facility known as Ponte de Pedra diverts part of the river flow into a diversion channel in a nearly "run-of-river" design. The natural (reconstructed) and regulated (observed) flow regimes were characterized using Indicators of Hydrologic Alteration (IHA) and Flow Duration Curves (FDC). Seven parameters of IHA were significantly altered by the reservoir formation (magnitude of lowest monthly flow, minimum flows of 1, 3 and 7 days, maximum flow of 90 days and counts of high and low pulses). Among these, Principal Components Analysis identified the maximum flow of 90 days and the count of high flow pulses as integrators of hydrological alterations. The FDC showed that the reservoir also changed the seasonal regime of the flows, with greater changes in the lowest flow season. The reduction of river-floodplain connectivity and loss of associated ecosystem services are the major downstream ecological implications of this altered flow regime. To maintain the seasonal flooding regime while meeting the requirements for hydroelectric production, proposed limits for flow regime alterations are up to ±18% in low flow, ±24% in the rising limb and ±22% in high flow and the falling limb, relative to the natural flow. Operational changes to maintain flows with these limits could easily be implemented because the

  2. Angioplasty and stent placement - carotid artery - discharge

    MedlinePlus

    ... angioplasty and stenting - discharge; CAS - discharge; Endarterectomy - carotid artery - discharge; Angioplasty - carotid artery - discharge ... were done to open a narrowed or blocked artery that supplies blood to your brain. Your health ...

  3. Overview of Initial NSTX-U Experimental Operations

    NASA Astrophysics Data System (ADS)

    Battaglia, Devon; the NSTX-U Team

    2016-10-01

    Initial operation of the National Spherical Torus Experiment Upgrade (NSTX-U) has satisfied a number of commissioning milestones, including demonstration of discharges that exceed the field and pulse length of NSTX. ELMy H-mode operation at the no-wall βN limit is obtained with Boronized wall conditioning. Peak H-mode parameters include: Ip = 1 MA, BT0 = 0.63 T, WMHD = 330 kJ, βN = 4, βN/li = 6, κ = 2.3, τE , tot >50 ms. Access to high-performance H-mode scenarios with long MHD-quiescent periods is enabled by the resilient timing of the L-H transition via feedback control of the diverting time and shape, and correction of the dominant n =1 error fields during the Ip ramp. Stationary L-mode discharges have been realized up to 1 MA with 2 s discharges achieved at Ip = 650 kA. The long-pulse L-mode discharges enabled by the new central solenoid supported initial experiments on error field measurements and correction, plasma shape control, controlled discharge ramp-down, L-mode transport and fast ion physics. Increased off-axis current drive and reduction of fast ion instabilities has been observed with the new, more tangential neutral beamline. The initial results support that access to increased field, current and heating at low-aspect-ratio expands the regimes available to develop scenarios, diagnostics and predictive models that inform the design and optimization of future burning plasma tokamak devices, including ITER. Work Supported by U.S. DOE Contract No. DE-AC02-09CH11466.

  4. Doped organic transistors operating in the inversion and depletion regime

    NASA Astrophysics Data System (ADS)

    Lüssem, Björn; Tietze, Max L.; Kleemann, Hans; Hoßbach, Christoph; Bartha, Johann W.; Zakhidov, Alexander; Leo, Karl

    2013-11-01

    The inversion field-effect transistor is the basic device of modern microelectronics and is nowadays used more than a billion times on every state-of-the-art computer chip. In the future, this rigid technology will be complemented by flexible electronics produced at extremely low cost. Organic field-effect transistors have the potential to be the basic device for flexible electronics, but still need much improvement. In particular, despite more than 20 years of research, organic inversion mode transistors have not been reported so far. Here we discuss the first realization of organic inversion transistors and the optimization of organic depletion transistors by our organic doping technology. We show that the transistor parameters—in particular, the threshold voltage and the ON/OFF ratio—can be controlled by the doping concentration and the thickness of the transistor channel. Injection of minority carriers into the doped transistor channel is achieved by doped contacts, which allows forming an inversion layer.

  5. Numerical modeling of ozone production in a pulsed homogeneous discharge: A parameter study

    SciTech Connect

    Nilsson, J.O.; Eninger, J.E.

    1997-02-01

    The pulsed volume discharge is an alternative for the efficient generation of ozone in compact systems. This paper presents a parameter study of the reactions in this kind of homogeneous discharge by using a numerical model which solves plasma chemical kinetic rate and energy equations. Results are presented of ozone generation efficiency versus ozone concentration for different parameter combinations. Two parameter regimes are identified and analyzed. In the plasma phase ozone formation regime, where significant amounts of ozone are produced during the discharge pulse, it is found that higher ozone concentrations can be obtained than in the neutral phase ozone formation regime, where most of the ozone is formed after the discharge pulse. In the two-step ozone formation process, the rate of conversion of atomic oxygen plays a key role. In both regimes the ozone generation efficiency increases as n is increased or T{sub 0} decreased. The maximum concentration is 3% at 10 amagat and 100 K. The results on ozone accumulation in multiple pulse discharges are presented. In contrast to the single pulse case, higher efficiency is achieved at lower gas density. This scaling can be explained by losses due to ion currents. A tradeoff can be made between ozone generation efficiency and the number of pulses required to reach a certain concentration.

  6. Low pressure arc discharge lamp apparatus with magnetic field generating means

    DOEpatents

    Grossman, M.W.; George, W.A.; Maya, J.

    1987-10-06

    A low-pressure arc discharge apparatus having a magnetic field generating means for increasing the output of a discharge lamp is disclosed. The magnetic field generating means, which in one embodiment includes a plurality of permanent magnets, is disposed along the lamp for applying a constant transverse magnetic field over at least a portion of the positive discharge column produced in the arc discharge lamp operating at an ambient temperature greater than about 25 C. 3 figs.

  7. Low pressure arc discharge lamp apparatus with magnetic field generating means

    DOEpatents

    Grossman, Mark W.; George, William A.; Maya, Jakob

    1987-01-01

    A low-pressure arc discharge apparatus having a magnetic field generating means for increasing the output of a discharge lamp is disclosed. The magnetic field generating means, which in one embodiment includes a plurality of permanent magnets, is disposed along the lamp for applying a constant transverse magnetic field over at least a portion of the positive discharge column produced in the arc discharge lamp operating at an ambient temperature greater than about 25.degree. C.

  8. Adaptation in Collaborative Governance Regimes

    NASA Astrophysics Data System (ADS)

    Emerson, Kirk; Gerlak, Andrea K.

    2014-10-01

    Adaptation and the adaptive capacity of human and environmental systems have been of central concern to natural and social science scholars, many of whom characterize and promote the need for collaborative cross-boundary systems that are seen as flexible and adaptive by definition. Researchers who study collaborative governance systems in the public administration, planning and policy literature have paid less attention to adaptive capacity specifically and institutional adaptation in general. This paper bridges the two literatures and finds four common dimensions of capacity, including structural arrangements, leadership, knowledge and learning, and resources. In this paper, we focus on institutional adaptation in the context of collaborative governance regimes and try to clarify and distinguish collaborative capacity from adaptive capacity and their contributions to adaptive action. We posit further that collaborative capacities generate associated adaptive capacities thereby enabling institutional adaptation within collaborative governance regimes. We develop these distinctions and linkages between collaborative and adaptive capacities with the help of an illustrative case study in watershed management within the National Estuary Program.

  9. Adaptation in collaborative governance regimes.

    PubMed

    Emerson, Kirk; Gerlak, Andrea K

    2014-10-01

    Adaptation and the adaptive capacity of human and environmental systems have been of central concern to natural and social science scholars, many of whom characterize and promote the need for collaborative cross-boundary systems that are seen as flexible and adaptive by definition. Researchers who study collaborative governance systems in the public administration, planning and policy literature have paid less attention to adaptive capacity specifically and institutional adaptation in general. This paper bridges the two literatures and finds four common dimensions of capacity, including structural arrangements, leadership, knowledge and learning, and resources. In this paper, we focus on institutional adaptation in the context of collaborative governance regimes and try to clarify and distinguish collaborative capacity from adaptive capacity and their contributions to adaptive action. We posit further that collaborative capacities generate associated adaptive capacities thereby enabling institutional adaptation within collaborative governance regimes. We develop these distinctions and linkages between collaborative and adaptive capacities with the help of an illustrative case study in watershed management within the National Estuary Program.

  10. Impurity confinement and transport in high confinement regimes without edge localized modes on DIII-D

    SciTech Connect

    Grierson, B. A. Nazikian, R. M.; Solomon, W. M.; Burrell, K. H.; Garofalo, A. M.; Belli, E. A.; Staebler, G. M.; Evans, T. E.; Smith, S. P.; Chrobak, C.; Fenstermacher, M. E.; McKee, G. R.; Orlov, D. M.; Chrystal, C.

    2015-05-15

    Impurity transport in the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] is investigated in stationary high confinement (H-mode) regimes without edge localized modes (ELMs). In plasmas maintained by resonant magnetic perturbation (RMP), ELM-suppression, and QH-mode, the confinement time of fluorine (Z = 9) is equivalent to that in ELMing discharges with 40 Hz ELMs. For selected discharges with impurity injection, the impurity particle confinement time compared to the energy confinement time is in the range of τ{sub p}/τ{sub e}≈2−3. In QH-mode operation, the impurity confinement time is shown to be smaller for intense, coherent magnetic, and density fluctuations of the edge harmonic oscillation than weaker fluctuations. Transport coefficients are derived from the time evolution of the impurity density profile and compared to neoclassical and turbulent transport models NEO and TGLF. Neoclassical transport of fluorine is found to be small compared to the experimental values. In the ELMing and RMP ELM-suppressed plasma, the impurity transport is affected by the presence of tearing modes. For radii larger than the mode radius, the TGLF diffusion coefficient is smaller than the experimental value by a factor of 2–3, while the convective velocity is within error estimates. Low levels of diffusion are observed for radii smaller than the tearing mode radius. In the QH-mode plasma investigated, the TGLF diffusion coefficient is higher inside of ρ=0.4 and lower outside of 0.4 than the experiment, and the TGLF convective velocity is more negative by a factor of approximately 1.7.

  11. Optical Characteristics of Cuinse2 Nanocrystals Synthesized by Electric Discharge in Ethanol

    NASA Astrophysics Data System (ADS)

    Burakov, V. S.; Nedelko, M. I.; Tarasenko, N. V.

    2016-01-01

    The optical characteristics of CuInSe 2 nanocrystals synthesized by electric discharged treatment of a stoichiometric mixture of copper, indium, and selenium powders in ethanol are discussed. The forbidden band width for the particles produced in various discharge regimes was determined by analysis of the absorption spectra. Data on the effect of laser radiation on the variation of the optical characteristics of the nanoparticles are presented.

  12. Similarity in Neuronal Firing Regimes across Mammalian Species

    PubMed Central

    Mochizuki, Yasuhiro; Onaga, Tomokatsu; Shimazaki, Hideaki; Shimokawa, Takeaki; Tsubo, Yasuhiro; Kimura, Rie; Saiki, Akiko; Sakai, Yutaka; Isomura, Yoshikazu; Fujisawa, Shigeyoshi; Shibata, Ken-ichi; Hirai, Daichi; Furuta, Takahiro; Kaneko, Takeshi; Takahashi, Susumu; Nakazono, Tomoaki; Ishino, Seiya; Sakurai, Yoshio; Kitsukawa, Takashi; Lee, Jong Won; Lee, Hyunjung; Jung, Min Whan; Babul, Cecilia; Maldonado, Pedro E.; Takahashi, Kazutaka; Arce-McShane, Fritzie I.; Ross, Callum F.; Sessle, Barry J.; Hatsopoulos, Nicholas G.; Brochier, Thomas; Riehle, Alexa; Chorley, Paul; Grün, Sonja; Nishijo, Hisao; Ichihara-Takeda, Satoe; Funahashi, Shintaro; Shima, Keisetsu; Mushiake, Hajime; Yamane, Yukako; Tamura, Hiroshi; Fujita, Ichiro; Inaba, Naoko; Kawano, Kenji; Kurkin, Sergei; Fukushima, Kikuro; Kurata, Kiyoshi; Taira, Masato; Tsutsui, Ken-Ichiro; Ogawa, Tadashi; Komatsu, Hidehiko; Koida, Kowa; Toyama, Keisuke; Richmond, Barry J.

    2016-01-01

    The architectonic subdivisions of the brain are believed to be functional modules, each processing parts of global functions. Previously, we showed that neurons in different regions operate in different firing regimes in monkeys. It is possible that firing regimes reflect differences in underlying information processing, and consequently the firing regimes in homologous regions across animal species might be similar. We analyzed neuronal spike trains recorded from behaving mice, rats, cats, and monkeys. The firing regularity differed systematically, with differences across regions in one species being greater than the differences in similar areas across species. Neuronal firing was consistently most regular in motor areas, nearly random in visual and prefrontal/medial prefrontal cortical areas, and bursting in the hippocampus in all animals examined. This suggests that firing regularity (or irregularity) plays a key role in neural computation in each functional subdivision, depending on the types of information being carried. SIGNIFICANCE STATEMENT By analyzing neuronal spike trains recorded from mice, rats, cats, and monkeys, we found that different brain regions have intrinsically different firing regimes that are more similar in homologous areas across species than across areas in one species. Because different regions in the brain are specialized for different functions, the present finding suggests that the different activity regimes of neurons are important for supporting different functions, so that appropriate neuronal codes can be used for different modalities. PMID:27225764

  13. State Waste Discharge Permit application: 200-E Powerhouse Ash Pit

    SciTech Connect

    Atencio, B.P.

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations, the US Department and 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. This document constitutes the State Waste Discharge Permit application for the 200-E Powerhouse Ash Pit. The 200-E Powerhouse Ash Waste Water discharges to the 200-E Powerhouse Ash Pit via dedicated pipelines. The 200-E Ash Waste Water is the only discharge to the 200-E Powerhouse Ash Pit. The 200-E Powerhouse is a steam generation facility consisting of a coal-handling and preparation section and boilers.

  14. State Waste Discharge Permit application: 200-W Powerhouse Ash Pit

    SciTech Connect

    Atencio, B.P.

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations; the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173-216 (or 173-218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. This document constitutes the State Waste Discharge Permit application for the 200-W Powerhouse Ash Pit. The 200-W Powerhouse Ash Waste Water discharges to the 200-W Powerhouse Ash Pit via dedicated pipelines. The 200-W Powerhouse Ash Waste Water is the only discharge to the 200-W Powerhouse Ash Pit. The 200-W Powerhouse is a steam generation facility consisting of a coal-handling and preparation section and boilers.

  15. High intensity discharge device containing oxytrihalides

    DOEpatents

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

    1987-06-09

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

  16. High intensity discharge device containing oxytrihalides

    DOEpatents

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

    1987-01-01

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

  17. Determination of discharge during pulsating flow

    USGS Publications Warehouse

    Thompson, T.H.

    1968-01-01

    Pulsating flow in an open channel is a manifestation of unstable-flow conditions in which a series of translatory waves of perceptible magnitude develops and moves rapidly downstream. Pulsating flow is a matter of concern in the design and operation of steep-gradient channels. If it should occur at high stages in a channel designed for stable flow, the capacity of the channel may be inadequate at a discharge that is much smaller than that for which the channel was designed. If the overriding translatory wave carries an appreciable part of the total flow, conventional stream-gaging procedures cannot be used to determine the discharge; neither the conventional instrumentation nor conventional methodology is adequate. A method of determining the discharge during pulsating flow was tested in the Santa Anita Wash flood control channel in Arcadia, Calif., April 16, 1965. Observations of the dimensions and velocities of translatory waves were made during a period of controlled reservoir releases of about 100, 200, and 300 cfs (cubic feet per second). The method of computing discharge was based on (1) computation of the discharge in the overriding waves and (2) computation of the discharge in the shallow-depth, or overrun, part of the flow. Satisfactory results were obtained by this method. However, the procedure used-separating the flow into two components and then treating the shallow-depth component as though it were steady--has no theoretical basis. It is simply an expedient for use until laboratory investigation can provide a satisfactory analytical solution to the problem of computing discharge during pulsating flow. Sixteen months prior to the test in Santa Anita Wash, a robot camera had been designed .and programmed to obtain the data needed to compute discharge by the method described above. The photographic equipment had been installed in Haines Creek flood control channel in Los Angeles, Calif., but it had not been completely tested because of the infrequency of

  18. Analysis of Multipactor Discharge

    SciTech Connect

    Lau, Y. Y.

    2005-08-31

    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. State waste discharge permit application: Hydrotest, maintenance and construction discharges. Revision 0

    SciTech Connect

    1995-11-01

    On December 23, 1991, the US DOE< Richland Operation Office (RL) and the Washington State Department of Ecology (Ecology) agreed to adhere to the provisions of the Department of Ecology Consent Order No. DE91NM-177 (216 Consent Order) (Ecology and US DOE 1991). The 216 Consent Order list regulatory milestones for liquid effluent streams at the Hanford Site and requires compliance with the permitting requirements of Washington Administrative Code. Hanford Site liquid effluent streams discharging to the soil column have been categorized on the 216 Consent Order as follows: Phase I Streams; Phase II Streams; Miscellaneous Streams. Phase I and Phase II Streams were initially addressed in two report. Miscellaneous Streams are subject to the requirements of several milestones identified in the 216 Consent Order. This document constitutes the Categorical State Waste Discharge Permit application for hydrotest,maintenance and construction discharges throughout the Hanford Site. This categorical permit application form was prepared and approved by Ecology.

  20. Effects of discharge voltage waveform on the discharge characteristics in a helium atmospheric plasma jet

    SciTech Connect

    Uchida, Giichiro Takenaka, Kosuke; Setsuhara, Yuichi

    2015-04-21

    We present here an analysis of the discharge characteristics of a He plasma jet operating under three different types of applied voltage waveform: (a) a μs-pulse voltage waveform with a slow voltage rise time, (b) ns-pulse, and (c) rectangular voltage waveforms with fast voltage rise time. Optical emission measurements show that the application of a voltage with a fast voltage rise time induces rapid discharge growth and, consequently, produces an abundance of energetic electrons, which in turn leads to high optical emission from the O atoms. We also estimate the optical emission efficiency of the O atom (η{sub o}), which corresponds roughly to the production efficiency of the reactive O species. η{sub o} increases with increasing applied voltage, and the highest value of η{sub o} is obtained in the shortest pulse discharge, which was ignited by a ns-pulse voltage waveform with a fast voltage rise time and short pulse width.

  1. Fire regime in Mediterranean ecosystem

    NASA Astrophysics Data System (ADS)

    Biondi, Guido; Casula, Paolo; D'Andrea, Mirko; Fiorucci, Paolo

    2010-05-01

    The analysis of burnt areas time series in Mediterranean regions suggests that ecosystems characterising this area consist primarily of species highly vulnerable to the fire but highly resilient, as characterized by a significant regenerative capacity after the fire spreading. In a few years the area burnt may once again be covered by the same vegetation present before the fire. Similarly, Mediterranean conifer forests, which often refers to plantations made in order to reforest the areas most severely degraded with high erosion risk, regenerate from seed after the fire resulting in high resilience to the fire as well. Only rarely, and usually with negligible damages, fire affects the areas covered by climax species in relation with altitude and soil types (i.e, quercus, fagus, abies). On the basis of these results, this paper shows how the simple Drossel-Schwabl forest fire model is able to reproduce the forest fire regime in terms of number of fires and burned area, describing whit good accuracy the actual fire perimeters. The original Drossel-Schwabl model has been slightly modified in this work by introducing two parameters (probability of propagation and regrowth) specific for each different class of vegetation cover. Using model selection methods based on AIC, the model with the optimal number of classes with different fire behaviour was selected. Two different case studies are presented in this work: Regione Liguria and Regione Sardegna (Italy). Both regions are situated in the center of the Mediterranean and are characterized by a high number of fires and burned area. However, the two regions have very different fire regimes. Sardinia is affected by the fire phenomenon only in summer whilst Liguria is affected by fires also in winter, with higher number of fires and larger burned area. In addition, the two region are very different in vegetation cover. The presence of Mediterranean conifers, (Pinus Pinaster, Pinus Nigra, Pinus halepensis) is quite spread in

  2. Annual bed-elevation regime in the alluvial channel of Squamish River, southwestern British Columbia Canada

    USGS Publications Warehouse

    Stanford, S.D.; Seidl, M.A.; Ashley, G.M.

    2000-01-01

    The aim of this study is to examine the annual regime of channel scour and fill by monitoring bed-elevation changes in a reach of Squamish River in southwestern British Columbia, Canada. Sonar surveys of 13 river cross-sections in a sandy gravel-bed single-channel study reach were repeated biweekly over a full hydrologic year (1995/6). The survey results show that bedload movement occurs as waves or pulses forming bedwaves that appear to maintain an overall coherence with movement downstream. These bedwaves propagate downstream by a mode here termed pulse scour and pulse fill, a process distinguished from the conventional mode of scour and fill commonly associated with flood events (here termed local scour and local fill). Bedwave celerity was estimated to be about 15.5 m d-1 corresponding to a bedwave residence time in the study reach of almost one hydrologic year. The total amount of local bed-elevation change ranged between 0.22 m and 2.41 m during the period of study. Analysis of the bed-elevation and flow data reveals that, because of the bedware phenomenon, there is no simple relation between the mean bed-elevation and discharge nor any strong linear correlation among cross-sectional behaviour. The bed-elevation data also suggest that complex changes to the bed within a cross-section are masked when the bed is viewed in one dimension, although no definitive trends in bed behaviour were found in the two-dimensional analysis. Although a weak seasonal effect is evident in this study, the bed-elevation regime is dominated by sediment supply-driven fluctuations in bedload transport occurring at timescales shorter than the seasonal fluctuation in discharge. The study also indicates that bed-elevation monitoring on Squamish River, and others like it, for purposes of detecting and measuring aggradation/degradation must take into account very considerable and normal channel-bed variability operating at timescales from hours to months. Copyright (C) 2000 John Wiley and

  3. A comprehensive inpatient discharge system.

    PubMed Central

    O'Connell, E. M.; Teich, J. M.; Pedraza, L. A.; Thomas, D.

    1996-01-01

    Our group has developed a computer system that supports all phases of the inpatient discharge process. The system fills in most of the physician's discharge order form and the nurse's discharge abstract, using information available from sign-out, order entry, scheduling, and other databases. It supplies information for referrals to outside institutions, and provides a variety of instruction materials for patients. Discharge forms can be completed in advance, so that the patient is not waiting for final paperwork. Physicians and nurses can work on their components independently, rather than in series. Response to the system has been very favorable. PMID:8947755

  4. Multi-Fluid Modeling of Low-Recycling Divertor Regimes

    SciTech Connect

    Smirnov, R. D.; Pigarov, A. Y.; Krasheninnikov, S. I.; Rognlien, T. D.; Soukhanovskii, V. A.; Rensink, M. E.; Maingi, Rajesh; Skinner, C. H.; Stotler, D. P.; Bell, R. E.; Kugel, H. W.

    2010-01-01

    The low-recycling regimes of divertor operation in a single-null NSTX magnetic configuration are studied using computer simulations with the edge plasma transport code UEDGE. The edge plasma transport properties pertinent to the low-recycling regimes are demonstrated. These include the flux-limited character of the parallel heat transport and the high plasma temperatures with the flattened profiles in the scrape-off-layer. It is shown that to maintain the balance of particle fluxes at the core interface the deuterium gas puffing rate should increase as the divertor recycling coefficient decreases. The radial profiles of the heat load to the outer divertor plate, the upstream radial plasma profiles, and the effects of the cross-field plasma transport in the low-recycling regimes are discussed. It is also shown that recycling of lithium impurities evaporating from the divertor plate at high surface temperatures can reverse the low-recycling divertor operational regime to the high-recycling one and may cause thermal instability of the divertor plate. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  5. Quantifying downstream impacts of impoundment on flow regime and channel planform, lower Trinity River, Texas

    NASA Astrophysics Data System (ADS)

    Wellmeyer, Jessica L.; Slattery, Michael C.; Phillips, Jonathan D.

    2005-07-01

    As human population worldwide has grown, so has interest in harnessing and manipulating the flow of water for the benefit of humans. The Trinity River of eastern Texas is one such watershed greatly impacted by engineering and urbanization. Draining the Dallas-Fort Worth metroplex, just under 30 reservoirs are in operation in the basin, regulating flow while containing public supplies, supporting recreation, and providing flood control. Lake Livingston is the lowest, as well as largest, reservoir in the basin, a mere 95 km above the Trinity's outlet near Galveston Bay. This study seeks to describe and quantify channel activity and flow regime, identifying effects of the 1968 closure of Livingston dam. Using historic daily and peak discharge data from USGS gauging stations, flow duration curves are constructed, identifying pre- and post-dam flow conditions. A digital historic photo archive was also constructed using six sets of aerial photographs spanning from 1938 to 1995, and three measures of channel activity applied using a GIS. Results show no changes in high flow conditions following impoundment, while low flows are elevated. However, the entire post-dam period is characterized by significantly higher rainfall, which may be obscuring the full impact of flow regulation. Channel activity rates do not indicate a more stabilized planform following dam closure; rather they suggest that the Trinity River is adjusting itself to the stress of Livingston dam in a slow, gradual process that may not be apparent in a modern time scale.

  6. Molecular systems under shock compression into the dense plasma regime: carbon dioxide and hydrocarbon polymers

    NASA Astrophysics Data System (ADS)

    Mattsson, Thomas R.; Cochrane, Kyle R.; Root, Seth; Carpenter, John H.

    2013-10-01

    Density Functional Theory (DFT) has proven remarkably accurate in predicting properties of matter under shock compression into the dense plasma regime. Materials where chemistry plays a role are of interest for many applications, including planetary science and inertial confinement fusion (ICF). As examples of systems where chemical reactions are important, and demonstration of the high fidelity possible for these both structurally and chemically complex systems, we will discuss shock- and re-shock of liquid carbon dioxide (CO2) in the range 100 to 800 GPa and shock compression of hydrocarbon polymers, including GDP (glow discharge polymer) which is used as an ablator in laser ICF experiments. Experimental results from Sandia's Z machine validate the DFT simulations at extreme conditions and the combination of experiment and DFT provide reliable data for evaluating existing and constructing future wide-range equations of state models for molecular compounds. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  7. Comparison of Small ELM Characteristics and Regimes in Alcator C-Mod, MAST, and NSTX

    SciTech Connect

    Maingi, Rajesh; Hubbard, A.E.; Meyer, H.; Kirk, A.; Maqueda, R.; Terry, J. L.

    2011-01-01

    We report on the status of a set of ITPA-coordinated experiments between the Alcator C-Mod, MAST and NSTX devices to compare the characteristics and access conditions of discharges with small edge-localized modes (ELMs). The small ELMs in C-Mod, MAST and one of the two small ELM types in NSTX exist when {beta}{sub ped}{sup pol} approached 10-15%, although the lower/upper limits of the operational windows differ. These small ELM regimes appear in diverted configurations very close to balanced double-null in each device. We classify these small ELMs as type II, based on the published characteristics from a number of previous studies. In addition, these type II ELMs in each device had multiple filaments with propagation in the co-I{sub p} or ion diamagnetic drift direction. Moreover, we conclude that these type II ELMs are distinct from the type V ELMs routinely observed in NSTX, which have one or two filaments and propagate in the electron diamagnetic drift direction.

  8. IMPACTS OF DAM BUILDING ON THE STREAM TEMPERATURE REGIME OF THE YANGTZE RIVER

    NASA Astrophysics Data System (ADS)

    Li, Q.

    2009-12-01

    The Yangtze River (Changjiang) is one of the most important rivers in the world. With population increase and economic growth, the stream temperature regime of the Yangtze River has been altered to some extent by human activities, including runoff impoundment (dam construction). To assess dam-induced alterations in the temperature regime of the Yangtze River quantitatively, this paper selected two key hydrological stations (i.e. Yichang and Cuntan stations) below and above the Three Gorges dam respectively as case study sites. Cuntan station is at the upper limit of Three Gorges reservoir controlling water and sediment discharge to the reservoir from the upper Yangtze River. Yichang station is the control point of the upper Yangtze River basin and located at the starting point of the middle reach of the Yangtze River, 44 km below the Three Gorges Dam and 6 km below the Gezhouba Dam. The Gezhouba reservoir, with a capacity of 1.58 × 109m3, is a run-of-river reservoir and located on the main stem of the Yangtze River, 38 km below the Three Gorges reservoir. The Three Gorges reservoir with a capacity of 3.93 × 1010 m3 spans the Yangtze River. On the consideration that the Gezhouba Reservoir and the Three Gorges Reservoir may impose impacts on the downstream temperature regime of Gezouba and Three Gorges dams to different extents respectively, the whole study periods were divided into 3 subperiods by the years when these two reservoirs started to store water respectively. On the basis of 50-year long time series of daily or ten-day stream temperature from two stations, their annual, seasonal, monthly and daily stream temperature, the correlation of the 10-day stream temperature values between Cuntan and Yichang, and the correlation of the 10-day stream temperature changing rates between Cuntan and Yichang in different subperiods were analyzed and compared. The stream temperature rising and falling characteristics and daily stream temperature distribution during the

  9. Estimated discharge of treated wastewater in Florida, 1990

    USGS Publications Warehouse

    Marella, R.L.

    1994-01-01

    According to the Florida Department of Environ- mental Protection, 5,100 wastewater treatment systems were in operation during 1990. Of this total, 72 percent were domestic wastewater facilities and 28 percent were industrial waste- water facilities. The number of wastewater systems inventoried for 1990 was 1,062 (systems that treated and discharged more than 0.01 Mgal/d or had a plant capacity of greater than 0.04 Mgal/d. Based on this inventory, the estimated discharge of treated wastewater in Florida during 1990 totaled 1,638 million gallons per day. Approxi- mately 65 percent of this water was discharged to surface water during 1990 and the remaining 35 percent was discharged to ground water. Discharge to surface water includes effluent outfalls into the Atlantic Ocean (32 percent), while the re- maining (68 percent) is discharged into the Gulf of Mexico, bays, rivers, wetlands, and other surface water bodies throughout Florida. Discharge to ground-water includes treated effluent outfalls to land application systems (reuse systems and spray fields), drain fields, percolation ponds (51 percent), and to injection wells (49 percent). An estimated 322 million gallons per day of the treated domestic and industrial wastewater was reused during 1990. Discharge of treated domestic wastewater from the 994 systems inventoried in Florida during 1990 totaled 1,353 million gallons per day and served an estimated 8.58 million people (66 percent of the population of Florida in 1990). The remaining 34 percent of the popu- lation (4.36 million) are served by the 2,700 smaller domestic wastewater systems or have individual septic tanks. In 1990, there were 1.56 million septic tanks in Florida. Discharge of industrial wastewater was inventoried for 68 systems in 1990 and totaled 285 million gallons per day. Discharge of domestic wastewater in- creased more than 20 percent and industrial wastewater discharge increased 5 percent from 1985 to 1990. (USGS)

  10. Spleen removal - child - discharge

    MedlinePlus

    ... activity restrictions will depend on: The type of surgery (open or laparoscopic) Your child's age The reason for the operation Ask your doctor about specific activity instructions and ... other pain medicines to use at home if your child needs them.

  11. Heart pacemaker - discharge

    MedlinePlus

    ... please enable JavaScript. A pacemaker is a small, battery-operated device that senses when your heart is ... pacemaker is placed under your skin. These include: Battery powered cordless tools (such as screwdrivers and drills) ...

  12. Implementation of Discharge Plans for Chronically Ill Elders Discharged Home.

    ERIC Educational Resources Information Center

    Proctor, Enola K.; And Others

    1996-01-01

    Addresses the extent to which discharge plans for elderly patients with congestive heart failure were implemented as planned, tested the consequences of implementation problems, and identified factors associated with implementation problems. Implications for hospital discharge planners and home health care are discussed. (KW)

  13. 49 CFR 194.105 - Worst case discharge.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... hours (based on historic discharge data or in the absence of such historic data, the operator's best... battery of tanks within a single secondary containment system, adjusted for the capacity or size of the secondary containment system, expressed in barrels (cubic meters). (4) Operators may claim...

  14. Neoclassical Tearing Modes characterization in JET ILW operation

    NASA Astrophysics Data System (ADS)

    Baruzzo, Matteo; Alper, Barry; Angioni, Clemente; Baranov, Yuriy; Buratti, Paolo; Casson, Francis; Hender, Tim; Mantica, Paola; Marchetto, Chiara; Lauro Taroni, Laura; Valisa, Marco; JET-EFDA Contributors Team

    2014-10-01

    After several years of operation with the ITER Like Wall a comprehensive evidence on the effect of Neoclassical Tearing Modes on discharge stability and confinement has been collected. NTMs appearance is coincident with a flattening of the electron temperature profile within the island (the effect with the C-wall), but it is sometimes correlated with enhanced core plasma radiation and eventually radiative collapse. A mechanism for W accumulation in presence of magnetic island has been outlined in, where the island is responsible of connecting two radial regions characterized by different transport regimes. In this work the statistics of W accumulation measured with bolometry and Soft X-ray will be correlated with the island radial position and island width as measured by fast Electron Cyclotron Emission for different toroidal mode numbers and in different tokamak operational scenarios. JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB, UK.

  15. The effects of water diversion and climate change on hydrological alteration and temperature regime of karst rivers in central Croatia.

    PubMed

    Zganec, Krešimir

    2012-09-01

    Karst rivers in Croatia have been heavily dammed in the past. However, long-term impacts of dams, water diversion and climate change on karst rivers in Croatia have rarely been examined. This study analyzes long-term trends of hydrological and temperature conditions, prior to closure of new large dam, in five connected karst rivers of central Croatia: the sinking rivers Gornja Dobra and Zagorska Mrežnica that have underground connections with the Gojačka Dobra, Tounjčica and Mrežnica Rivers. It was established that hydrological conditions of these rivers have been greatly changed after the Gojak HPP, located at spring of Gojačka Dobra, became operational in 1959. Water diversion from the reservoirs on Zagorska Mrežnica and Gornja Dobra to the Gojak HPP has increased mean annual discharge (52-106%), causing great subdaily fluctuations and overall modification of natural flow regime along the whole course of Gojačka Dobra. By cutting the connection between Zagorska Mrežnica and Tounjčica, water diversion has caused a reduction of mean annual discharges of the Tounjčica (-60%) and Mrežnica (-29%) Rivers. Analyses of long-term trends in water temperature over the last 50 years have revealed significant positive trends in average annual temperature at three gauging stations on three rivers with increase of 0.17, 0.44 and 0.48°C per decade and climate change as the primary cause. The highest significant increasing trend was established at the lower course of Mrežnica where discharge was reduced by water diversion. Mitigation measures for the improvement of hydrological conditions of affected rivers and underground systems are proposed and discussed.

  16. Disruption characteristics in PDX with limiter and divertor discharges

    SciTech Connect

    Couture, P.; McGuire, K.

    1986-09-01

    A comparison has been made between the characteristics of disruptions with limiter and divertor configurations in PDX. A large data base on disruptions has been collected over four years of machine operation, and a total of 15,000 discharges are contained in the data file. It was found that divertor discharges have less disruptions during ramp up and flattop of the plasma current. However, for divertor discharges a large number of fast, low current disruptions take place during the current ramp down. These disruptions are probably caused by the deformation of the plasma shape.

  17. Spent nuclear fuel discharges from U.S. reactors 1994

    SciTech Connect

    1996-02-01

    Spent Nuclear Fuel Discharges from US Reactors 1994 provides current statistical data on fuel assemblies irradiated at commercial nuclear reactors operating in the US. This year`s report provides data on the current inventories and storage capacities at these reactors. Detailed statistics on the data are presented in four chapters that highlight 1994 spent fuel discharges, storage capacities and inventories, canister and nonfuel component data, and assembly characteristics. Five appendices, a glossary, and bibliography are also included. 10 figs., 34 tabs.

  18. Use of flumes in metering discharge at gaging stations

    USGS Publications Warehouse

    Kilpatrick, F.A.; Schneider, V.R.

    1982-01-01

    Flumes for metering discharge are usually of two general types--critical-flow flumes and supercritical-flow flumes. In this report the principles underlying the design of each are discussed, the most commonly used flumes of each of the two types are described, and discharge ratings for each are presented. Considerations in choosing and fitting the appropriate flume for a given situation are discussed along with construction techniques and operational experiences.

  19. Interactions between surface discharges induced by volume discharges in a dielectric barrier discharge system

    SciTech Connect

    Gao, Yenan; Dong, Lifang Zhao, Longhu; Wang, Yongjie; Pan, Yuyang; Li, Ben

    2014-10-15

    The interaction between micro-discharges involved in surface discharges (SDs) is studied in dielectric barrier discharge system. Instantaneous images taken by high speed cameras show that the SDs are induced by volume discharges (VDs). They cannot cross the midperpendicular of two neighbouring volume charges at low voltage while they stretch along it at high voltage, indicating that there is interaction between SDs. The differences of plasma parameters between SD and VD are studied by optical emission spectroscopy. The simulation of the electric fields of the wall charges accumulated by VD further confirms the existence of the interaction.

  20. Simultaneous transient operation of a high head hydro power plant and a storage pumping station in the same hydraulic scheme

    NASA Astrophysics Data System (ADS)

    Bucur, D. M.; Dunca, G.; Cervantes, M. J.; Cǎlinoiu, C.; Isbǎşoiu, E. C.

    2014-03-01

    This paper presents an on-site experimental analysis of a high head hydro power plant and a storage pumping station, in an interconnected complex hydraulic scheme during simultaneous transient operation. The investigated hydropower site has a unique structure as the pumping station discharges the water into the hydropower plant penstock. The operation regimes were chosen for critical scenarios such as sudden load rejections of the turbines as well as start-ups and stops with different combinations of the hydraulic turbines and pumps operation. Several parameters were simultaneously measured such as the pumped water discharge, the pressure at the inlet pump section, at the outlet of the pumps and at the vane house of the hydraulic power plant surge tank. The results showed the dependence of the turbines and the pumps operation. Simultaneous operation of the turbines and the pumps is possible in safe conditions, without endangering the machines or the structures. Furthermore, simultaneous operation of the pumping station together with the hydropower plant increases the overall hydraulic efficiency of the site since shortening the discharge circuit of the pumps.