Science.gov

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. Determination of the Hall Thruster Operating Regimes

    SciTech Connect

    L. Dorf; V. Semenov; Y. Raitses; N.J. Fisch

    2002-04-09

    A quasi one-dimensional (1-D) steady-state model of the Hall thruster is presented. For the same discharge voltage two operating regimes are possible -- with and without the anode sheath. For given mass flow rate, magnetic field profile and discharge voltage a unique solution can be constructed, assuming that the thruster operates in one of the regimes. However, we show that for a given temperature profile the applied discharge voltage uniquely determines the operating regime: for discharge voltages greater than a certain value, the sheath disappears. That result is obtained over a wide range of incoming neutral velocities, channel lengths and widths, and cathode plane locations. It is also shown that a good correlation between the quasi 1-D model and experimental results can be achieved by selecting an appropriate electron mobility and temperature profile.

  4. 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.

  5. 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.

  6. 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.

  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.

    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.

  8. 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.

  9. Ongoing Explorations of Exceptional Lightning Discharges in Several Meteorological Regimes

    NASA Astrophysics Data System (ADS)

    Lyons, W. A.; Warner, T. A.; Cummer, S. A.; Lang, T. J.; Orville, R. E.

    2010-12-01

    As new observing technologies and methodologies become available to any scientific discipline, unexpected discoveries often follow. This has certainly been true with regard to atmospheric electricity and lightning studies, as witnessed by the advancements allowed by regional and national lightning detection networks and radar. More recently, the ability to operationally monitor CG impulse charge moment changes (iCMC) using the National Charge Moment Change Network (CMCN), the advent of deployable high speed video imagers (to 10,000 images/sec and even faster), low-light television (LLTV) systems for detecting transient luminous events (TLEs), 3-D Lightning Mapping Arrays (LMA), and new software tools which facilitate the analysis and display of these complex data sets, is creating new areas of exploration of the lightning discharge plus delving into the characteristics of the storms which generate exceptional lightning discharges. By flagging those +CGs with large iCMCs values (>~300 C km), it is now possible in real-time to identify convective storms highly likely to generate TLEs, especially sprites. The ability of LLTVs to monitor TLEs above storms at ranges approaching 900 km (under ideal conditions) has allowed coordinated measurements, using high speed (1000-10,000 images/sec) video systems, of +CGs triggering both sprites and upward discharges from tall broadcast towers. Four such events were captured in the Rapid City area in May and June, 2010. Detailed analyses of the lightning video, the TLE imagery, and the NLDN, CMCN, and NEXRAD data are delineating the time line of these complex discharges in the context of their meteorological environment. The use of LLTVs to monitor TLEs above distant LMAs enabled studies of two MCSs traversing the Oklahoma LMA (OKLMA) in 2007. Continued analyses of these discharges, some >200 km in length, find sprite parent +CGs lowering charge to ground from altitudes varying from 4 to 8 or 9 km AGL, depending upon storm

  10. 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.

  11. 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.

  12. 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.

  13. UV radiation sources operating in an abnormal microdischarge regime

    NASA Astrophysics Data System (ADS)

    Starostin, S. A.; Mitko, S. V.; Peters, P. J. M.; Boller, K. J.; Udalov, Yu. B.

    2002-10-01

    Recently we proposed a new design approach for microdischarge plasma sources and microdischarge arrays [1]. The major improvement comes from the fact that the ceramic dielectric layer is sintered directly on the metal cathode. The discharge channels are drilled in the dielectric layer mechanically or by laser. This design approach excludes the undesirable cathode spot spread, which usually occurs if dielectric is mechanically pressed on the cathode surface. Another advantage is a possibility of efficient cooling. The electrical characteristics of a single microdischarge and microdischarge array operating in abnormal regime were investigated in different gas mixtures (He, Ar, Xe, He-Ar-Xe, He-Xe-HCl) at different gas pressures and configurations of the discharge set-up. The studied set-up allows to achieve discharge voltages up to 2kV in continuous wave DC mode at gas pressures of 100-200 mbar in He or He-Xe gas mixtures. The obtained results indicate that this kind of discharge can be considered as a low-energy electron-beam source. It can be used for efficient pumping of gas lasers (for instance atomic Xe) or for large area planar VUV light sources based on excimers with relatively high excitation threshold (for instance He2 or Ne2 dimers). 1. RU.Patent N^o 2172573

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Wildfire vs. Agricultural Operations: A Tale of Overprinted Disturbance Regimes

    NASA Astrophysics Data System (ADS)

    Gray, A. B.; Pasternack, G. B.; Watson, E. B.; Warrick, J. A.; Hatten, J. A.; Goni, M. A.

    2016-12-01

    Punctuated disturbances, such as wildfire, compete with interdecadal scale changes to land surfaces, such as shifting agricultural practices, resulting in complex trends in the suspended sediment transport dynamics of watersheds. A powerful, though data intensive approach to identifying dominant disturbance regimes is the application of retrospective forensic analysis, whereby time series of major factors potentially affecting watershed expression are investigated. In the test case, a decreasing trend in discharge corrected suspended sediment concentrations was found in the lower Salinas River, California between 1967 and 2011. Event to decadal scale patterns in sediment production in the Salinas River have been found to be largely controlled by antecedent hydrologic conditions, but decreasing suspended sediment concentrations over the last 15 years of the record departed from those expected from hydro-climatic forcing. Sediment production from the mountainous headwaters of the central California Coast Ranges, which are drained in part by the Salinas River, is known to be dominated by the interaction of wildfire and large rainfall/runoff events. However, the decreasing trend in Salinas River suspended sediment concentrations run contrary to increases in the watershed's effective burn area over time. The departure from hydrologic and wildfire forcing on suspended sediment concentration patterns was found to coincide with a rapid conversion of irrigation practices from sprinkler and furrow to subsurface drip irrigation. Changes in agricultural operations appear to have decreased sediment supply to the Salinas River over late 20th to early 21st century; obscuring the influence of wildfire on suspended sediment production.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Hysteresis, regime shifts, and non-stationarity in aquifer recharge-storage-discharge systems

    NASA Astrophysics Data System (ADS)

    Klammler, Harald; Jawitz, James; Annable, Michael; Hatfield, Kirk; Rao, Suresh

    2016-04-01

    Based on physical principles and geological information we develop a parsimonious aquifer model for Silver Springs, one of the largest karst springs in Florida. The model structure is linear and time-invariant with recharge, aquifer head (storage) and spring discharge as dynamic variables at the springshed (landscape) scale. Aquifer recharge is the hydrological driver with trends over a range of time scales from seasonal to multi-decadal. The freshwater-saltwater interaction is considered as a dynamic storage mechanism. Model results and observed time series show that aquifer storage causes significant rate-dependent hysteretic behavior between aquifer recharge and discharge. This leads to variable discharge per unit recharge over time scales up to decades, which may be interpreted as a gradual and cyclic regime shift in the aquifer drainage behavior. Based on field observations, we further amend the aquifer model by assuming vegetation growth in the spring run to be inversely proportional to stream velocity and to hinder stream flow. This simple modification introduces non-linearity into the dynamic system, for which we investigate the occurrence of rate-independent hysteresis and of different possible steady states with respective regime shifts between them. Results may contribute towards explaining observed non-stationary behavior potentially due to hydrological regime shifts (e.g., triggered by gradual, long-term changes in recharge or single extreme events) or long-term hysteresis (e.g., caused by aquifer storage). This improved understanding of the springshed hydrologic response dynamics is fundamental for managing the ecological, economic and social aspects at the landscape scale.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

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

    NASA Astrophysics Data System (ADS)

    Brandenburg, Ronny

    2017-05-01

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

  14. 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.

  15. Improving the accuracy of operation coding in surgical discharge summaries

    PubMed Central

    Martinou, Eirini; Shouls, Genevieve; Betambeau, Nadine

    2014-01-01

    Procedural coding in surgical discharge summaries is extremely important; as well as communicating to healthcare staff which procedures have been performed, it also provides information that is used by the hospital's coding department. The OPCS code (Office of Population, Censuses and Surveys Classification of Surgical Operations and Procedures) is used to generate the tariff that allows the hospital to be reimbursed for the procedure. We felt that the OPCS coding on discharge summaries was often incorrect within our breast and endocrine surgery department. A baseline measurement over two months demonstrated that 32% of operations had been incorrectly coded, resulting in an incorrect tariff being applied and an estimated loss to the Trust of £17,000. We developed a simple but specific OPCS coding table in collaboration with the clinical coding team and breast surgeons that summarised all operations performed within our department. This table was disseminated across the team, specifically to the junior doctors who most frequently complete the discharge summaries. Re-audit showed 100% of operations were accurately coded, demonstrating the effectiveness of the coding table. We suggest that specifically designed coding tables be introduced across each surgical department to ensure accurate OPCS codes are used to produce better quality surgical discharge summaries and to ensure correct reimbursement to the Trust. PMID:26734286

  16. H2OTSTUF: Appropriate Operating Regimes for Magnetohydrodynamic Augmentation

    NASA Technical Reports Server (NTRS)

    Jones, Jonathan E.; Hawk, Clark W.

    1998-01-01

    A trade study of magnetohydrodynamic (MHD) augmented propulsion reveals a unique operating regime at lower thrust levels. Substantial mass savings are realized over conventional chemical, solar, and electrical propulsion concepts when MHD augmentation is used to obtain optimal I(sub sp). However, trip times for the most conservative estimates of power plant specific impulse and accelerator efficiency may be prohibitively long. Quasi-one-dimensional calculations show that a solar or nuclear thermal system augmented by MHD can provide competitive performance while utilizing a diverse range of propellants including water, which is available from the Space Shuttle, the Moon, asteroids, and various moons and planets within our solar system. The use of in-situ propellants will reduce costs of space operations as well as enable human exploration of our Solar System. The following conclusions can be drawn from the results of the mission trade study: (1) There exists a maximum thrust or mass flow rate above which MHD augmentation increases the initial mass in low earth orbit (LEO); (2) Mass saving of over 50% can be realized for unique combination of solar/MHD systems; (3) Trip times for systems utilizing current power supply technology may be prohibitively long. Theoretical predictions of MHD performance for in space propulsion systems show that improved efficiencies can reduce trip times to acceptable levels; (4) Long trip times indicative of low thrust systems can be shortened by an increase in the MHD accelerator efficiency or a decrease in the specific mass of the power supply and power processing unit; and (5) As for all propulsion concepts, missions with larger (Delta)v's benefit more from the increased specific impulse resulting from MHD augmentation. Using a quasi-one-dimensional analysis, the required operating conditions for a MHD accelerator to reach acceptable efficiencies are outlined. This analysis shows that substantial non-equilibrium ionization is

  17. Orbital motion theory and operational regimes for cylindrical emissive probes

    NASA Astrophysics Data System (ADS)

    Chen, Xin; Sanchez-Arriaga, G.

    2017-02-01

    A full-kinetic model based on the orbital-motion theory for cylindrical emissive probes (EPs) is presented. The conservation of the distribution function, the energy, and the angular momentum for cylindrical probes immersed in collisionless and stationary plasmas is used to write the Vlasov-Poisson system as a single integro-differential equation. It describes self-consistently the electrostatic potential profile and, consequently, the current-voltage (I-V) probe characteristics. Its numerical solutions are used to identify different EP operational regimes, including orbital-motion-limited (OML)/non-OML current collection and monotonic/non-monotonic potential, in the parametric domain of probe bias and emission level. The most important features of the potential and density profiles are presented and compared with common approximations in the literature. Conventional methods to measure plasma potential with EPs are briefly revisited. A direct application of the model is to estimate plasma parameters by fitting I-V measurements to the theoretical results.

  18. Operating regimes of covalent modification cycles at high enzyme concentrations.

    PubMed

    Straube, Ronny

    2017-10-27

    The Goldbeter-Koshland model has been a paradigm for ultrasensitivity in biological networks for more than 30 years. Despite its simplicity the validity of this model is restricted to conditions when the substrate is in excess over the converter enzymes - a condition that is easy to satisfy in vitro, but which is rarely satisfied in vivo. Here, we analyze the Goldbeter-Koshland model by means of the total quasi-steady state approximation which yields a comprehensive classification of the steady state operating regimes under conditions when the enzyme concentrations are comparable to or larger than that of the substrate. Where possible we derive simple expressions characterizing the input-output behavior of the system. Our analysis suggests that enhanced sensitivity occurs if the concentration of at least one of the converter enzymes is smaller (but not necessarily much smaller) than that of the substrate and if that enzyme is saturated. Conversely, if both enzymes are saturated and at least one of the enzyme concentrations exceeds that of the substrate the system exhibits concentration robustness with respect to changes in that enzyme concentration. Also, depending on the enzyme's saturation degrees and the ratio between their maximal reaction rates the total fraction of phosphorylated substrate may increase, decrease or change nonmonotonically as a function of the total substrate concentration. The latter finding may aid the interpretation of experiments involving genetic perturbations of enzyme and substrate abundances. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. 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. © 2015 The Authors. Groundwater published by Wiley

  20. A single width-discharge regime relationship for individual threads of braided and meandering rivers from the Himalayan Foreland

    NASA Astrophysics Data System (ADS)

    Gaurav, K.; Tandon, S. K.; Devauchelle, O.; Sinha, R.; Métivier, F.

    2017-10-01

    We explore the existence of a single width-discharge regime relation for alluvial rivers of braided and meandering patterns. The study relies on the field measurement of a channel's cross section geometry (width, depth), discharge, and grain size of 98 individual threads of braided and meandering rivers from the Ganga-Brahmaputra plains of the Himalayan Foreland. Using this data set, we show that, irrespective of the diverse climatic and geologic setting along the strike, the braided and meandering threads share statistically indistinguishable regime relations and scale according to Lacey's law. To explain the observed trend in this empirical relationship, we use the threshold theory introduced by Glover and Florey (1951). Using this theory we detrend our data with respect to discharge to produce a statistically homogeneous ensemble of width measurements. The statistical distribution of the detrended width is similar for braided and meandering threads of the entire plains of the Foreland. This suggests that when we decompose a braided river into individual threads, each of these resemble single-thread meandering rivers. Based on this study, we conclude that the individual threads of braided and meandering rivers of the Himalayan Foreland are geometrically comparable and share a common width-discharge regime relation.

  1. Computing anode heating voltage in high-pressure arc discharges and modelling rod electrodes in dc and ac regimes

    NASA Astrophysics Data System (ADS)

    Almeida, N. A.; Cunha, M. D.; Benilov, M. S.

    2017-09-01

    Numerical modelling of near-anode layers in arc discharges in several gases (Ar, Xe and Hg) is performed in a wide range of current densities, anode surface temperatures, and plasma pressures. It is shown that the density of energy flux to the anode is only weakly affected by the anode surface temperature and varies linearly with the current density. This allows one to interpret the results in terms of anode heating voltage (volt equivalent of the heat flux to the anode). The computed data may be useful in different ways. An example considered in this work concerns the evaluation of thermal regime of anodes in the shape of a thin rod operating in the diffuse mode. Invoking the model of nonlinear surface heating for cathodes, one obtains a simple and free of empirical parameters model of thin rod electrodes applicable to dc and ac high-pressure arcs provided that no anode spots are present. The model is applied to a variety of experiments reported in the literature and a good agreement with the experimental data found.

  2. 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.

  3. Post-operative recovery profile after laparoscopic cholecystectomy: a prospective, observational study of a multimodal anaesthetic regime.

    PubMed

    Jensen, K; Kehlet, H; Lund, C M

    2007-04-01

    Laparoscopic cholecystectomy is now often an ambulatory procedure, but dependent on short-term post-operative complaints of pain and post-operative nausea and vomiting (PONV). The efficacy of post-anaesthesia care units (PACUs) is therefore important to facilitate return to normal functions. We investigated the feasibility and efficacy of a standardized, evidence-based anaesthesia/analgesic regime to identify residual problems in the early post-operative phase. One hundred and thirty-four consecutive patients admitted for elective laparoscopic cholecystectomy at Hvidovre University Hospital between 15 March and 30 September 2005 were included in the study. The standardized, evidence-based regime consisted of total intravenous (i.v.) anaesthesia (propofol-remifentanil), well-defined fluid therapy, dexamethasone, ketorolac, ondansetron, sufentanil and incisional bupivacaine intra-operatively, and in the PACU on demand (prn) administration of sufentanil, morphine, paracetamol, ondansetron, droperidol, oral fluids and oxygen (if SpO(2) < 93%) with PACU discharge using a modified Aldrete score. Protocol violations were moderate and occurred unsystematically, 8% had medical violations and 10% did not receive the pre-planned fluid amount. Severe PONV was seen in 2%. Thirteen per cent experienced severe pain, and the presence of any pain and/or PONV were predictors of an extended PACU stay. Mean oxygen demand was 46 min (range, 0-300 min), which influenced time to discharge (mean, 88 min). There were on average 2.7 treatment interventions (range, 0-11) before discharge. An evidence-based, multimodal approach to the anaesthetic/analgesic management in laparoscopic cholecystectomy is feasible and advantageous in the early post-operative phase. Pain and PONV are predictors of a complicated recovery profile and deserve further attention. Transient oxygen desaturations postpone discharge from the PACU, but the clinical significance of this fact is questionable.

  4. 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.

  5. 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.

  6. 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.

  7. Spatio-temporal characterization of the multiple current pulse regime of diffuse barrier discharges in helium with nitrogen admixtures

    NASA Astrophysics Data System (ADS)

    Bogaczyk, Marc; Tschiersch, Robert; Nemschokmichal, Sebastian; Meichsner, Jürgen

    2017-10-01

    This work reports on the spatio-temporal characterization of the multiple current pulse regime of diffuse barrier discharges driven by sine-wave feeding voltage at a frequency of 2~kHz in helium with small nitrogen admixtures. The discharge gap of 3~mm is bounded by glass plates on both plane electrodes. Priority is given to the lateral discharge inhomogeneities, underlying volume- and surface-memory effects, and the breakdown mechanism. Therefore, relevant processes in the discharge volume and on the dielectric surfaces were investigated by ICCD camera imaging and optical emission spectroscopy in combination with electrical measurements and surface charge diagnostics using the electro-optic Pockels effect of a bismuth silicon oxide crystal. The number of current pulses per half-cycle of the sine-wave voltage rises with increasing nitrogen admixture to helium due to the predominant role of the Penning ionization. Here, the transition from the first glow-like breakdown to the last Townsend-like breakdown is favored by residual species from the former breakdowns which enhance the secondary electron emission during the pre-phase of the later breakdowns. Moreover, the surface charge measurements reveal that the consecutive breakdowns occur alternately at central and peripheral regions on the electrode surface. These spatial inhomogeneities are conserved by the surface charge memory effect as pointed out by the recalculated spatio-temporal development of the gap voltage.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Linkages between rainfall regimes and storage-discharge relations under climate variability in coastal California watersheds

    NASA Astrophysics Data System (ADS)

    Chen, Y. J.; Jones, C.; Melack, J. M.

    2016-12-01

    The effect of climate variability on hydrologic responses within watersheds is reflected by the variability in the amount of rainfall, stream flow, and water storage. Climate variability from synoptic, intra-seasonal to inter-annual temporal scales can lead to shifts in the frequency of rainfall. We examined long-term rain and streamflow data as well as climate variability indices in coastal California watersheds in order to examine interactions between climate variability, rainfall, and storage-discharge conditions. We interpolated the spatial distributions of rainfall and correlated them with climate variability indices including atmospheric rivers (AR), Madden Julian Oscillation (MJO), and El Niño Southern Oscillation (ENSO), for water years 1970 to 2014. Atmospheric rivers influenced 48% of large rainfall events (>90 percentile) from 1989 to 2010, 47% of large rainfall events are associated with active MJO from 1970 to 2014, and 26% of large rainfall events are attributed to the occurrence of weak warm phase of ENSO. We also examine the relationship between climatic factors and variations in storage-discharge within different local watersheds. Our study offers a compelling case study on combining climate variability, rainfall, and storage conditions to provide critical information for managing water resources.

  14. 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.

  15. 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

  16. Extension of the operational regime of the LHD towards a deuterium experiment

    NASA Astrophysics Data System (ADS)

    Takeiri, Y.; Morisaki, T.; Osakabe, M.; Yokoyama, M.; Sakakibara, S.; Takahashi, H.; Nakamura, Y.; Oishi, T.; Motojima, G.; Murakami, S.; Ito, K.; Ejiri, A.; Imagawa, S.; Inagaki, S.; Isobe, M.; Kubo, S.; Masamune, S.; Mito, T.; Murakami, I.; Nagaoka, K.; Nagasaki, K.; Nishimura, K.; Sakamoto, M.; Sakamoto, R.; Shimozuma, T.; Shinohara, K.; Sugama, H.; Watanabe, K. Y.; Ahn, J. W.; Akata, N.; Akiyama, T.; Ashikawa, N.; Baldzuhn, J.; Bando, T.; Bernard, E.; Castejón, F.; Chikaraishi, H.; Emoto, M.; Evans, T.; Ezumi, N.; Fujii, K.; Funaba, H.; Goto, M.; Goto, T.; Gradic, D.; Gunsu, Y.; Hamaguchi, S.; Hasegawa, H.; Hayashi, Y.; Hidalgo, C.; Higashiguchi, T.; Hirooka, Y.; Hishinuma, Y.; Horiuchi, R.; Ichiguchi, K.; Ida, K.; Ido, T.; Igami, H.; Ikeda, K.; Ishiguro, S.; Ishizaki, R.; Ishizawa, A.; Ito, A.; Ito, Y.; Iwamoto, A.; Kamio, S.; Kamiya, K.; Kaneko, O.; Kanno, R.; Kasahara, H.; Kato, D.; Kato, T.; Kawahata, K.; Kawamura, G.; Kisaki, M.; Kitajima, S.; Ko, W. H.; Kobayashi, M.; Kobayashi, S.; Kobayashi, T.; Koga, K.; Kohyama, A.; Kumazawa, R.; Lee, J. H.; López-Bruna, D.; Makino, R.; Masuzaki, S.; Matsumoto, Y.; Matsuura, H.; Mitarai, O.; Miura, H.; Miyazawa, J.; Mizuguchi, N.; Moon, C.; Morita, S.; Moritaka, T.; Mukai, K.; Muroga, T.; Muto, S.; Mutoh, T.; Nagasaka, T.; Nagayama, Y.; Nakajima, N.; Nakamura, Y.; Nakanishi, H.; Nakano, H.; Nakata, M.; Narushima, Y.; Nishijima, D.; Nishimura, A.; Nishimura, S.; Nishitani, T.; Nishiura, M.; Nobuta, Y.; Noto, H.; Nunami, M.; Obana, T.; Ogawa, K.; Ohdachi, S.; Ohno, M.; Ohno, N.; Ohtani, H.; Okamoto, M.; Oya, Y.; Ozaki, T.; Peterson, B. J.; Preynas, M.; Sagara, S.; Saito, K.; Sakaue, H.; Sanpei, A.; Satake, S.; Sato, M.; Saze, T.; Schmitz, O.; Seki, R.; Seki, T.; Sharov, I.; Shimizu, A.; Shiratani, M.; Shoji, M.; Skinner, C.; Soga, R.; Stange, T.; Suzuki, C.; Suzuki, Y.; Takada, S.; Takahata, K.; Takayama, A.; Takayama, S.; Takemura, Y.; Takeuchi, Y.; Tamura, H.; Tamura, N.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Tanaka, T.; Tanaka, Y.; Toda, S.; Todo, Y.; Toi, K.; Toida, M.; Tokitani, M.; Tokuzawa, T.; Tsuchiya, H.; Tsujimura, T.; Tsumori, K.; Usami, S.; Velasco, J. L.; Wang, H.; Watanabe, T.-H.; Watanabe, T.; Yagi, J.; Yajima, M.; Yamada, H.; Yamada, I.; Yamagishi, O.; Yamaguchi, N.; Yamamoto, Y.; Yanagi, N.; Yasuhara, R.; Yatsuka, E.; Yoshida, N.; Yoshinuma, M.; Yoshimura, S.; Yoshimura, Y.

    2017-10-01

    As the finalization of a hydrogen experiment towards the deuterium phase, the exploration of the best performance of hydrogen plasma was intensively performed in the large helical device. High ion and electron temperatures, T i and T e, of more than 6 keV were simultaneously achieved by superimposing high-power electron cyclotron resonance heating onneutral beam injection (NBI) heated plasma. Although flattening of the ion temperature profile in the core region was observed during the discharges, one could avoid degradation by increasing the electron density. Another key parameter to present plasma performance is an averaged beta value ≤ft< β \\right> . The high ≤ft< β \\right> regime around 4% was extended to an order of magnitude lower than the earlier collisional regime. Impurity behaviour in hydrogen discharges with NBI heating was also classified with a wide range of edge plasma parameters. The existence of a no impurity accumulation regime, where the high performance plasma is maintained with high power heating  >10 MW, was identified. Wide parameter scan experiments suggest that the toroidal rotation and the turbulence are the candidates for expelling impurities from the core region.

  17. 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.

  18. High calorie and protein clear fluid regime for pre-operative bowel preparation.

    PubMed

    Fletcher, J P; Little, J M

    1986-09-01

    The effect of a high calorie and protein clear fluid regime for pre-operative bowel preparation was assessed in 16 patients requiring aortic grafting for aneurysm or occlusive disease. Patients were randomized to receive either standard clear fluids or a special high calorie and protein clear fluid regime for 48 h pre-operatively. Nitrogen balance was calculated for the first 5 postoperative days. The group receiving the special high calorie and protein clear fluid regime had a consistent reduction in negative nitrogen balance on each day of the study with a mean daily negative nitrogen balance of 9.00 g compared to 12.33 g, this difference being highly significant (P = 0.004).

  19. Cell chip temperature measurements in different operation regimes of HCPV modules

    NASA Astrophysics Data System (ADS)

    Rumyantsev, V. D.; Chekalin, A. V.; Davidyuk, N. Yu.; Malevskiy, D. A.; Pokrovskiy, P. V.; Sadchikov, N. A.; Pan'chak, A. N.

    2013-09-01

    A new method has been developed for accurate measurements of the solar cell temperature in maximum power point (MPP) operation regime in comparison with that in open circuit (OC) regime (TMPP and TOC). For this, an electronic circuit has been elaborated for fast variation of the cell load conditions and for voltage measurements, so that VOC values could serve as an indicator of TMPP at the first moment after the load disconnection. The method was verified in indoor investigations of the single-junction AlGaAs/GaAs cells under CW laser irradiation, where different modifications of the heat spreaders were involved. PV modules of the "SMALFOC" design (Small-size concentrators; Multijunction cells; "All-glass" structure; Lamination technology; Fresnel Optics for Concentration) with triple-junction InGaP/GaAs/Ge cells were examined outdoors to evaluate temperature regimes of their operation.

  20. The operating regime in mechanical pulps--the significance of fiber failure

    Treesearch

    Lauri K. Lehtonen; Alan W. Rudie; Douglas W. Coffin; Derek H. Page

    2004-01-01

    In order to circumvent the problem of altering the sheet composition to increase bonding, in this study the bonding was increased by wet pressing and press drying sheets to various levels of RBA. The operating regime problem was then studied by interpreting the tear relative to bonding (where bonding is measured as T/Z, Tensile index/Zero span tensile index)...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  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. Discharge pumped iodine monofluoride laser: Operating parameters and collisional kinetics

    NASA Astrophysics Data System (ADS)

    Dlabal, M. L.

    Lasing was observed at five different wavelengths ranging from 472 to 497 nm from discharge pumped iodine monofluoride (IF). At the optimum output coupling 4 mJ was measured in a 30 ns FWHM pulse with a peak power of 140 kW. The merits and deficiencies of both HI and CF3I as iodine donors are discussed. Measurements show the small signal gain to be or = 1%/cm from 478 to 497 nm, while much of the absorption is due to excited state of He. Limited line tunability is also demonstrated by using an internally mounted Littrow prism. Quenching measurements of the upper and lowr laser level show the lower level to be removed more rapidly, thereby avoiding bottlenecking. In addition, the upper level spontaneous emission lifetime is measured to 17.2 + or - 4.0 ns. Finally studies of the formation kinetics of the upper laser level of IF show I (4P) atoms to be an immediate precursor, while the F (4P) atoms are unimportant.

  10. 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.

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

    SciTech Connect

    Garofalo, A. M. Burrell, K. H.; Meneghini, O.; Osborne, T. H.; Paz-Soldan, C.; Smith, S. P.; Snyder, P. B.; Turnbull, A. D.; Eldon, D.; Grierson, B. A.; Solomon, W. M.; Hanson, J. M.; Holland, C.; Huijsmans, G. T. A.; Liu, F.; Loarte, A.; Zeng, L.

    2015-05-15

    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-like 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. The DIII-D results are in excellent agreement with these predictions, and nonlinear magnetohydrodynamic 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.

  12. Determinants of early discharge from the intensive care unit after cardiac operations.

    PubMed

    Ranucci, Marco; Bellucci, Carmen; Conti, Daniela; Cazzaniga, Anna; Maugeri, Bruno

    2007-03-01

    The length of stay in the intensive care unit is one of the factors limiting operating room utilization in cardiac surgery. We investigated the impact of a goal-oriented program aimed at discharging the patients from the intensive care unit the morning after the operation within a comprehensive model including other explanatory variables. A multivariable predictive model for early discharge from the intensive care unit was established using a stepwise forward logistic regression. The analysis was retrospectively conducted on 9120 consecutive patients undergoing cardiac surgical procedures at our institution. A total of 1874 patients were discharged early from the intensive care unit. Factors associated with early discharge were ejection fraction, lowest hematocrit on cardiopulmonary bypass, lowest temperature on cardiopulmonary bypass, and the presence of the goal-oriented strategy (odds ratio, 5.5; 95% confidence interval, 4.8 to 6.3). Factors associated with late discharge were age, preoperative serum creatinine value, unstable angina, congestive heart failure, redo operation, combined operation, and cardiopulmonary bypass duration. An extubation time of 4 hours after the arrival in the intensive care unit was associated with the peak rate of early discharge. Patients being early discharged according to the goal-oriented strategy did not demonstrate a different complication rate compared with patients treated with a standard strategy. Early discharge from the intensive care unit depends on a combination of preoperative and intraoperative factors, but most of all on the presence of a goal-oriented strategy. A very early extubation is not required for an early discharge from the intensive care unit.

  13. 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.

  14. Fast reactor: an experimental study of thermohydraulic processes in different operating regimes

    NASA Astrophysics Data System (ADS)

    Opanasenko, A. N.; Sorokin, A. P.; Zaryugin, D. G.; Trufanov, A. A.

    2017-05-01

    Results of integrated water model studies of temperature fields and a flow pattern of a nonisothermal primary coolant in the elements of the fast neutron reactor (hereinafter, fast reactor) primary circuit with primary sodium in different regimes, such as forced circulation (FC), transition to the reactor cooldown and emergency cooldown with natural coolant convection, are presented. It is shown that, under the influence of lift forces on the nonisothermal coolant flow in the upper chamber at the periphery of its bottom region over the side shields, a stable cold coolant isothermal zone is formed, whose dimensions increase with increase of total water flowrate. An essential and stable coolant temperature stratification is detected in the peripheral area of the upper (hot) chamber over the side shields, in the pressure and cold side chambers, in the elevator baffle, in the cooling system of the reactor vessel, and in the outlet of intermediate and autonomous heat exchangers in different operating regimes. Large gradients and temperature fluctuations are registered at the interface of stratified and recycling formations. In all of the studied cooldown versions, the coolant outlet temperature at the core fuel assembly is decreased and the coolant temperature in the peripheral zone of the upper chamber is increased compared to the FC. High performance of a passive emergency cooldown system of a fast reactor (BN-1200) with submersible autonomous heat exchangers (AHE) is confirmed. Thus, in a normal operation regime, even in case of malfunction of three submersible AHEs, the temperature of the equipment inside the reactor remains within acceptable limits and decay heat removal from the reactor does not exceed safe operation limits. The obtained results can be used both for computer code verification and for approximate estimate of the reactor plant parameters on the similarity criteria basis.

  15. Comparing Postprocessing Approaches to Calibrating Operational River Discharge Forecasts

    NASA Astrophysics Data System (ADS)

    Hopson, T. M.; Webster, P. J.; Wood, A. W.

    2010-12-01

    With rare exceptions, current operational ensemble weather and hydrologic forecast systems require a final post-processing step to steer the forecast products towards satisfying the twin constraints of greater reliability while retaining (or enhancing) forecast sharpness. Such post-processing of model output can be viewed as an extension of the modeling effort itself, such as in the case of under-dispersive ensemble forecasts, where post-processing of the ensemble dispersion can implicitly account for missing scales of variability or mis-representation of physical processes. Over the last decade a number of different approaches have emerged that show consistent utility in calibrating ensembles derived from a variety of forecasting systems. In this work we compare and contrast four such approaches under differing operational constraints (e.g. data size limitations): logistic regression, an analogue approach, Bayesian model averaging, and quantile regression. The setting for this study is the Climate Forecasting Applications for Bangladesh (CFAB) forecast system, which over the last decade has been providing operational probabilistic forecasts of severe flooding of the Brahmaputra and Ganges Rivers as part of a humanitarian effort to mitigate the impacts of these events on the country of Bangladesh. The flood forecasting system developed utilizes weather forecast uncertainty information provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble weather forecasts, rain gauge and satellite-derived precipitation estimates from NASA and NOAA, along with near-real-time river stage observations provided by the Flood Forecasting and Warning Centre of Bangladesh. This paper will discuss both the results of the post-processing comparison study more generally, and also within the unique context of this ongoing flood forecasting effort for Bangladesh.

  16. 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.

  17. 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...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Imaging in the visible wavelength range through anisotropic layered flat lens operating in the canalization regime

    NASA Astrophysics Data System (ADS)

    Pastuszczak, Anna; Kotynski, Rafal

    2010-04-01

    We study the propagation of light through silver-dielectric layered structures operating in the canalization regime. These structures have an extremely large value of the effective permittivity in the propagation direction. Therefore they are able to couple a broad spectrum of incident spatial frequencies, including evanescent waves, into propagating modes. As a result, subwavelength resolution at the back interface of the structure is observed. We consider multilayers made of silver and several dielectric materials, namely TiO2, SrTiO3 and GaP. We optimise the multilayers geometry in order to obtain the best resolution accompanied with a large value of the effective skin depth. We use the full width at half-maximum (FWHM) of the point spread function to measure the resolution. The effective skin depth is calculated both approximately based on the effective medium model and rigorously by analysing the amplitude decay rate in an infinite periodic layered structure.

  8. A bank-operated traveling-block cableway for stream discharge and sediment measurements

    Treesearch

    James J. Paradiso

    2000-01-01

    Streams often present a challenge for collecting flow and sediment measurements on a year-round basis. Streams that can normally be waded become hazardous during seasonal flows, either endangering hydrographers or precluding data collection completely. A hand-operated cableway permits the accurate and safe collection of discharge and sediment data from the stream bank...

  9. 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...

  10. 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...

  11. 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...

  12. 33 CFR 151.73 - Operating requirements: Discharge of garbage from fixed or floating platforms.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID... Protocol on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.73 Operating requirements: Discharge of garbage from fixed or floating platforms...

  13. 33 CFR 151.73 - Operating requirements: Discharge of garbage from fixed or floating platforms.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID... Protocol on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.73 Operating requirements: Discharge of garbage from fixed or floating platforms...

  14. 33 CFR 151.73 - Operating requirements: Discharge of garbage from fixed or floating platforms.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID... Protocol on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.73 Operating requirements: Discharge of garbage from fixed or floating platforms...

  15. 33 CFR 151.69 - Operating requirements: Discharge of garbage outside special areas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES... on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.69 Operating requirements: Discharge of garbage outside special areas. (a) When...

  16. 33 CFR 151.73 - Operating requirements: Discharge of garbage from fixed or floating platforms.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID... Protocol on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.73 Operating requirements: Discharge of garbage from fixed or floating platforms...

  17. 33 CFR 151.69 - Operating requirements: Discharge of garbage outside special areas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES... on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.69 Operating requirements: Discharge of garbage outside special areas. (a) Except...

  18. 33 CFR 151.71 - Operating requirements: Discharge of garbage within special areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES... on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.71 Operating requirements: Discharge of garbage within special areas. (a) When a...

  19. 33 CFR 151.69 - Operating requirements: Discharge of garbage outside special areas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES... on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.69 Operating requirements: Discharge of garbage outside special areas. (a) Except...

  20. 33 CFR 151.69 - Operating requirements: Discharge of garbage outside special areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES... on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.69 Operating requirements: Discharge of garbage outside special areas. (a) When...

  1. 33 CFR 151.73 - Operating requirements: Discharge of garbage from fixed or floating platforms.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID... Protocol on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.73 Operating requirements: Discharge of garbage from fixed or floating platforms...

  2. 33 CFR 151.69 - Operating requirements: Discharge of garbage outside special areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES... on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.69 Operating requirements: Discharge of garbage outside special areas. (a) When...

  3. 33 CFR 151.71 - Operating requirements: Discharge of garbage within special areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES... on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.71 Operating requirements: Discharge of garbage within special areas. (a) When a...

  4. 33 CFR 151.71 - Operating requirements: Discharge of garbage within special areas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES... on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.71 Operating requirements: Discharge of garbage within special areas. (a) When a...

  5. 33 CFR 151.71 - Operating requirements: Discharge of garbage within special areas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES... on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.71 Operating requirements: Discharge of garbage within special areas. (a) When a...

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

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

    SciTech Connect

    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.

    2016-06-20

    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 ITBs. 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 2 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. Finally, more investigations will be carried out on EAST with more additional auxiliary power to come online in the near term.

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

    DOE PAGES

    Ren, Q. L.; Garofalo, A. M.; Gong, X. Z.; ...

    2016-06-20

    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 ITBs. Good confinement has been achieved with reduced toroidal rotation. These high βp plasmas challenge the energy transport understanding, especially in the electronmore » energy channel. A new turbulent transport model, named 2 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. Finally, more investigations will be carried out on EAST with more additional auxiliary power to come online in the near term.« less

  17. 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.

  18. 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.

  19. 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.

  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, 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 pollution...

  2. 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...

  3. 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...

  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. 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.

  7. 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.

  8. Environmental and economic assessment of discharges from Gulf of Mexico Region Oil and Gas Operations

    SciTech Connect

    Gettleson, D.A.

    1997-11-24

    Task 3 (Environmental Field Sampling and Analysis of NORM, Heavy Metals, and Organics) and 4 (Monitoring of the Recovery of Impacted Wetland and Open Bay Produced Water Discharge Sites in Coastal Louisiana and Texas) activities involved continued data analysis and report writing. Task 5 (Assessment of Economic Impacts of Offshore and Coastal Discharge Requirements on Present and Future Operations in the Gulf of Mexico Region) was issued as a final report during the previous reporting period. Task 6 (Synthesis of Gulf of Mexico Seafood Consumption and Use Patterns) activities included the preparation of the final report. There were no Task 7 (Technology Transfer Plan) activities to report. Task 8 (Project Management and Deliverables) activities involved the submission of the necessary reports and routine management.

  9. Operation of an Extremely Compact Capillary Discharge Soft X-Ray Laser

    NASA Astrophysics Data System (ADS)

    Benware, B. R.; Moreno, C. H.; Burd, D. J.; Rocca, J. J.

    1996-11-01

    A major goal in ultrashort wavelength laser research is the development of practical laser sources that can impact applications. Of particular interest is the development of compact "table-top" amplifiers. We have previously reported the first observation of large soft x-ray amplification, at 46.9 nm in the J=0-1 line of Ne-like argon in a plasma column generated by a fast capillary discharge.(J. J. Rocca, V. Shlyaptsev, F. G. Tomasel, O. D. Cortazar, D. Hartshorn, and J. L. A. Chilla, Phys. Rev. Lett. 73), 2192 (1994). Herein we report the successful operation of an extremely compact table-top discharge driven 46.9 nm laser. Measurement of the soft x-ray laser output pulse energy, pulse duration and beam divergence will be reported. Work supported by the National Science Foundation.

  10. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  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. 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

  13. 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.

  14. Observations of a helium-air gas-confined barrier discharge operated in diffuse mode

    NASA Astrophysics Data System (ADS)

    Wu, Shuqun; Dong, Xi; Mao, Wenhao; Yue, Yuanfu; Jiang, Jun; Zhang, Chaohai; Lu, Xinpei

    2017-08-01

    With ambient air instead of solid dielectric operating as the insulating layer, a diffuse helium/air gas-confined barrier discharge with a coaxial jet configuration is demonstrated for the first time. The effects of the helium gas flow rate, the diameter, and the vertical position of the helium gas flow on the breakdown characteristics of the diffuse mode are investigated. As the applied voltage increases, a diffuse plasma layer is first ignited within the helium gas column followed by a typical filamentary discharge bridging the whole gap. With the replacement of ambient air by N2 or O2 gas, the diffuse mode can be achieved with relatively lower breakdown voltage in the case of N2 gas while it is not observable in the case of O2 gas. The dynamics of the diffuse discharge show that the plasma front crosses the helium gas column vertically at an average velocity of ˜104 m/s, and then splits into two horizontally counter-propagating plasma fronts with the dark channel left behind.

  15. Super H-mode: theoretical prediction and initial observations of a new high performance regime for tokamak operation

    DOE PAGES

    Snyder, Philip B.; Solomon, Wayne M.; Burrell, Keith H.; ...

    2015-07-21

    A new “Super H-mode” regime is predicted, which enables pedestal height and predicted fusion performance substantially higher than for H-mode operation. This new regime is predicted to exist by the EPED pedestal model, which calculates criticality constraints for peeling-ballooning and kinetic ballooning modes, and combines them to predict the pedestal height and width. EPED usually predicts a single (“H-mode”) pedestal solution for each set of input parameters, however, in strongly shaped plasmas above a critical density, multiple pedestal solutions are found, including the standard “Hmode” solution, and a “Super H-Mode” solution at substantially larger pedestal height and width. The Supermore » H-mode regime is predicted to be accessible by controlling the trajectory of the density, and to increase fusion performance for ITER, as well as for DEMO designs with strong shaping. A set of experiments on DIII-D has identified the predicted Super H-mode regime, and finds pedestal height and width, and their variation with density, in good agreement with theoretical predictions from the EPED model. Finally, the very high pedestal enables operation at high global beta and high confinement, including the highest normalized beta achieved on DIII-D with a quiescent edge.« less

  16. Super H-mode: theoretical prediction and initial observations of a new high performance regime for tokamak operation

    SciTech Connect

    Snyder, Philip B.; Solomon, Wayne M.; Burrell, Keith H.; Garofalo, Andrea M.; Grierson, Brian A.; Groebner, Richard J.; Leonard, Anthony W.; Nazikian, Raffi; Osborne, Thomas H.; Belli, Emily A.; Candy, John; Wilson, Howard R.

    2015-07-21

    A new “Super H-mode” regime is predicted, which enables pedestal height and predicted fusion performance substantially higher than for H-mode operation. This new regime is predicted to exist by the EPED pedestal model, which calculates criticality constraints for peeling-ballooning and kinetic ballooning modes, and combines them to predict the pedestal height and width. EPED usually predicts a single (“H-mode”) pedestal solution for each set of input parameters, however, in strongly shaped plasmas above a critical density, multiple pedestal solutions are found, including the standard “Hmode” solution, and a “Super H-Mode” solution at substantially larger pedestal height and width. The Super H-mode regime is predicted to be accessible by controlling the trajectory of the density, and to increase fusion performance for ITER, as well as for DEMO designs with strong shaping. A set of experiments on DIII-D has identified the predicted Super H-mode regime, and finds pedestal height and width, and their variation with density, in good agreement with theoretical predictions from the EPED model. Finally, the very high pedestal enables operation at high global beta and high confinement, including the highest normalized beta achieved on DIII-D with a quiescent edge.

  17. 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...

  18. 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...

  19. 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

  20. 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.

  1. Changes in long-term flow regimes in Mekong River and their implications in riverine ecosystems and reservoir operation

    NASA Astrophysics Data System (ADS)

    Dongnan, L.; Long, D.; Zhao, J.; Lu, H.; Hong, Y.

    2016-12-01

    Human activities, such as dam construction, significantly alter the flow regimes in Mekong River, especially after the completion of two large dams, namely, Xiaowan and Nuozadu, in 2010 and 2014, respectively. Streamflow data from 1960 to 2014 obtained from six stations located along the Mekong mainstream are divided into three periods, i.e., the pre-impact period (1960-1991), the transition period (1992-2009), and the impacted period (2010-2014). The flow regimes are investigated using eco-low metrics and the indicators of hydrologic alteration (IHA). Principal component analysis is applied to select key indices from IHA. Results show that damming the upstream area reduced the annual streamflow in upstream Chiang Saen gauging station, whereas no clear effect was observed in downstream Stung Treng station. Operation of dams reduces the streamflow in wet seasons and increases the streamflow in dry seasons, leading to unique seasonal variation in streamflow in terms of eco-flow metrics in Chiang Saen gauging station from 2010 to 2014. In addition, no notable change has been observed in the date of occurrence of extreme flows. In upstream Chiang Saen gauging station, the maximum flow values decreased significantly in the year corresponding to the completion of the Manwan, Dachaoshan, and Jinghong Dams. The construction and operation of dams clearly exerted significant impacts on low pulse duration. The 90-day maximum flow, high and low pulse duration, number of fluctuations, and date of the occurrence of maximum flow are selected to reflect flow regimes in Mekong River. On one hand, changes in flow regimes influence the riverine ecosystems; on the other hand, these changes are beneficial in downstream irrigation, flood management, and navigation. The results of this study provide reference for reservoir operation in upstream regions, taking into consideration both the ecological and economic benefits of such operation, as well as for maximizing the interests of

  2. 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.

  3. Design and construction of uniform glow discharge plasma system operating under atmospheric condition

    SciTech Connect

    Kocum, C.; Ayhan, H.

    2007-06-15

    The design of a uniform glow discharge plasma system operating without vacuum is presented. A full-bridge switching circuit was used to switch the transformers. The primary windings of transformers were connected in parallel, but in opposite phase to double the output voltage. Theoretically, 20 000 V{sub pp} was obtained. Rectangle copper electrodes were used, and placed parallel to each other. To prevent the spark production that is, to obtain uniformity, two 2 mm Teflon sheets were glued to the electrodes. However, it was observed that the operating frequency also affected the uniformity. For the system presented here, the frequency at which more uniformity was obtained was found to be 14 kHz.

  4. Porous anodes with helical flow pathways in bioelectrochemical systems: The effects of fluid dynamics and operating regimes

    NASA Astrophysics Data System (ADS)

    Kim, Jung Rae; Boghani, Hitesh C.; Amini, Negar; Aguey-Zinsou, Kondo-François; Michie, Iain; Dinsdale, Richard M.; Guwy, Alan J.; Guo, Zheng Xiao; Premier, Giuliano C.

    2012-09-01

    Bioelectrochemical systems (BES) and/or microbial fuel cell (MFC) mass transport and associated over-potential limitations are affected by flow regimes, which may simultaneously increase the power and pollution treatment capacities. Two electrodes with helical flow channels were compared in the same tubular MFC reactor. 1). A machined monolithic microporous conductive carbon (MMCC). 2). A layered carbon veil with spoked ABS former (LVSF); both presented helical flow channel. Anode performances were compared when subject to temperature, substrate concentration and flow rate variations. The MMCC maximum power increased from 2.9 ± 0.3 to 7.6 ± 0.7 mW with influent acetate concentration, from 1 to 10 mM (with 2 mL min-1), but decreased power to 5.5 ± 0.5 mW at 40 mM, implicated localized pH/buffering. Flow rate (0.1 to 7.5 mL min-1) effects were relatively small but an increase was evident from batch to continuous operation at 0.1 mL min-1. The LVSF configuration showed improved performance in power as the flow rate increased, indicating that flow pattern affects BES performance. Computational fluid dynamics (CFD) modelling showed less uniform flow with the LVSF. Thus flow regime driven mass transfer improves the power output in continuously fed system operation. These results indicate that electrode configuration, flow regime and operating condition need consideration to optimize the bioelectrochemical reaction.

  5. 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.

  6. 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.

  7. Environmental and economic assessment of discharges from Gulf of Mexico region oil and gas operations

    SciTech Connect

    Gettleson, D.A.

    1993-04-22

    Task 3 (Environmental Field Sampling and Analysis of NORM, Heavy Metals, and Organics) activities included the continuation of the platform selection process. A revised sampling plan and a projected cost estimate were prepared for Task 3. A letter detailing the revised plan was sent to the Scientific Review Committee (SRC). Task 4 (Monitoring of the Recovery of Impacted Wetland and Open Bay Produced Water Discharge Sites in Coastal Louisiana and Texas) activities involved receiving the final approval for sampling two facilities and requesting approval for a third alternative facility. A revised Task 4 sampling plan and projected estimated costs were prepared. The sampling plan was presented to the SRC for comment. Mobilization activities for the first quarterly sampling were initiated. Task 5 (Assessment of Economic Impactsof Offshore and Coastal Discharge Requirements on Present and Future Operations in the Gulf of Mexico Region) activities included refining the model for estimating the impact of increased environmental compliance costs on remaining reserves in coastal and offshore fields. Task 6 (Synthesis of Gulf of Mexico Seafood Consumption and Use Patterns) activities involved completion and field testing of most survey forms. Retail surveys were initiated and contacts were made with the Vietnamese community. Task 7 (Technology Transfer Plan) work has included scheduling the presentation of information concerning this project at the DOE Contractor Review Meeting in July in Oklahoma. Task 8 (Project Management and Deliverables) activities have involved the submission of the necessary reports and routine management.

  8. 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.

  9. 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.

  10. Electron beam and plasma modes of a channel spark discharge operation

    SciTech Connect

    Gleizer, S.; Yarmolich, D.; Felsteiner, J.; Krasik, Ya. E.; Nozar, P.; Taliani, C.

    2009-10-01

    Parameters of a modified pulsed channel spark discharge (CSD), operating at a repetition rate up to 100 Hz at Ar gas pressures of 10{sup -3} and 10{sup -4} Torr and of the generated electron beam, were studied using different electrical, optical, and x-ray diagnostics. It was shown that efficient (up to approx74%) transfer of the initially stored energy to the energetic electron beam is realized only at the pressure of 10{sup -4} Torr. Conversely, at the pressure of 10{sup -3} Torr, less than 10% of the stored energy is acquired by the energetic electrons. It was found that the energetic electron beam generation is limited by the expansion of the cathode and anode plasmas and by the formation of plasma inside the gap between the CSD capillary output and the anode. It was also found that the plasma, which acquires the hollow cathode potential, is already formed at the beginning of the CSD operation inside the capillary, and the electron emission occurs from the capillary output plasma boundary. Finally, it was shown that the electron beam energy spectrum differs significantly from the energy spectrum, which one may expect in the case of the planar diode operation.

  11. Variations of Hydrological Regime in the Jingjiang Reach of the Yangtze River after Operation of the Three Gorges Project

    NASA Astrophysics Data System (ADS)

    Zhu, Y.-H.; Guo, X.-H.; Hu, W.; Qu, G.; He, G.-S.

    2012-04-01

    The Three Gorges Project (TGP) of China has been in operation since 2003. In October 2010 the water level at the Three Gorges Dam (TGD) rose to the normal storage water level of 175 m, indicting the realization of the integrated targets of the TGP in terms of flood protection, electricity generation, navigation, etc. The operation of the TGP has changed the flow and sediment conditions (i.e. the hydrological regime) of the river channel downstream. The 347.2 km Jingjiang Reach, part of the middle reach of the Yangtze River, is very closely dowstream of the TGD and is affected relatively earlier and significant by the project operation. Based on the measured prototype hydrological data from 1950 to 2010, variations of the hydrological regime in the Jingjiang Reach after operation of the TGP are analyzed. The results showing that the runoff of the river is of no clear variation tendency during the last 60 years. However, after the operation of the TGP, the sediment concentration of the flow in the Jingjiang Reach decreased by 75%; coarsening of the suspended load and bed load in the river is evident; the water level at the same flow rate has a tendency to decline, with the margin of decline of the upper Jingjiang Reach being larger than that of the lower Reach, and that at smaller flow rate being larger than at larger flow rate. The flow and sediment diversion from the Yangtze River to the Dongting Lake via the three outlets also has a tendency to decrease; the degree of dcrease of the sediment diversion is much larger than that of the flow diversion. After the operation of the TGP, except the 2006 is a special low flow year, in which the decrease of the ratios of flow and sediment diversion are relatively large, the ratios are of no clear unidirectional variation tendency in the other years. Due to the operation of the TGP, within one year, the flow diversion in October is decreased comparing with that before the operation. Keywords: The Three Gorges Project, the

  12. Compatibility of internal transport barrier with steady-state operation in the high bootstrap fraction regime on DIII-D

    SciTech Connect

    Garofalo, Andrea M.; Gong, Xianzu; Grierson, Brian A.; Ren, Qilong; Solomon, Wayne M.; Strait, Edward J.; Van Zeeland, Michael A.; Holcomb, Christopher T.; Meneghini, Orso; Smith, Sterling P.; Staebler, Gary M.; Wan, Baonian; Bravenec, Ronald; Budny, Robert V.; Ding, Siye; Hanson, Jeremy M.; Heidbrink, William W.; Lao, Lang L.; Li, Guoqiang; Pan, Chengkang; Petty, Craig C.; Qian, Jingping; Paz-Soldan, Carlos; Xu, Guosheng

    2015-11-16

    Recent EAST/DIII-D joint experiments on the high poloidal beta tokamak regime in DIII-D have demonstrated fully noninductive operation with an internal transport barrier (ITB) at large minor radius, at normalized fusion performance increased by ≥30% relative to earlier work. The advancement was enabled by improved understanding of the “relaxation oscillations”, previously attributed to repetitive ITB collapses, and of the fast ion behavior in this regime. It was found that the “relaxation oscillations” are coupled core-edge modes 2 amenable to wall-stabilization, and that fast ion losses which previously dictated a large plasma-wall separation to avoid wall over-heating, can be reduced to classical levels with sufficient plasma density. By using optimized waveforms of the plasma-wall separation and plasma density, fully noninductive plasmas have been sustained for long durations with excellent energy confinement quality, bootstrap fraction ≥ 80%, βN ≤ 4 , βP ≥ 3 , and βT ≥ 2%. Finally, these results bolster the applicability of the high poloidal beta tokamak regime toward the realization of a steady-state fusion reactor.

  13. Compatibility of internal transport barrier with steady-state operation in the high bootstrap fraction regime on DIII-D

    DOE PAGES

    Garofalo, Andrea M.; Gong, Xianzu; Grierson, Brian A.; ...

    2015-11-16

    Recent EAST/DIII-D joint experiments on the high poloidal beta tokamak regime in DIII-D have demonstrated fully noninductive operation with an internal transport barrier (ITB) at large minor radius, at normalized fusion performance increased by ≥30% relative to earlier work. The advancement was enabled by improved understanding of the “relaxation oscillations”, previously attributed to repetitive ITB collapses, and of the fast ion behavior in this regime. It was found that the “relaxation oscillations” are coupled core-edge modes 2 amenable to wall-stabilization, and that fast ion losses which previously dictated a large plasma-wall separation to avoid wall over-heating, can be reduced tomore » classical levels with sufficient plasma density. By using optimized waveforms of the plasma-wall separation and plasma density, fully noninductive plasmas have been sustained for long durations with excellent energy confinement quality, bootstrap fraction ≥ 80%, βN ≤ 4 , βP ≥ 3 , and βT ≥ 2%. Finally, these results bolster the applicability of the high poloidal beta tokamak regime toward the realization of a steady-state fusion reactor.« less

  14. Numerical Simulation of Table-Top Tunable Smith-Purcell Teraherz Free-Electron Laser Operating in the Superradiant Regime

    SciTech Connect

    Prokop, C.; Piot, P.; Lin, M.C.; Stoltz, P.; /Fermilab /Northern Illinois U.

    2010-01-01

    Terahertz (THz) radiation occupies a very large portion of the electromagnetic spectrum and has generated much recent interest due to its ability to penetrate deep into many organic materials without the damage associated with ionizing radiation such as x-rays. One path for generating copious amount of tunable narrow-band THz radiation is based on the Smith-Purcell free-electron laser (SPFEL) effect. In this Letter we propose a simple concept for a compact tunable SPFEL operating in the superradiant regime and demonstrate its capabilities and performances via computer simulation using the conformal finite-difference time-domain electromagnetic solver VORPAL.

  15. 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)

  16. 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.

  17. Does arousal interfere with operant conditioning of spike-wave discharges in genetic epileptic rats?

    PubMed

    Osterhagen, Lasse; Breteler, Marinus; van Luijtelaar, Gilles

    2010-06-01

    One of the ways in which brain computer interfaces can be used is neurofeedback (NF). Subjects use their brain activation to control an external device, and with this technique it is also possible to learn to control aspects of the brain activity by operant conditioning. Beneficial effects of NF training on seizure occurrence have been described in epileptic patients. Little research has been done about differentiating NF effectiveness by type of epilepsy, particularly, whether idiopathic generalized seizures are susceptible to NF. In this experiment, seizures that manifest themselves as spike-wave discharges (SWDs) in the EEG were reinforced during 10 sessions in 6 rats of the WAG/Rij strain, an animal model for absence epilepsy. EEG's were recorded before and after the training sessions. Reinforcing SWDs let to decreased SWD occurrences during training; however, the changes during training were not persistent in the post-training sessions. Because behavioural states are known to have an influence on the occurrence of SWDs, it is proposed that the reinforcement situation increased arousal which resulted in fewer SWDs. Additional tests supported this hypothesis. The outcomes have implications for the possibility to train SWDs with operant learning techniques. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Benthic foraminiferal responses to operational drill cutting discharge in the SW Barents Sea - a case study.

    NASA Astrophysics Data System (ADS)

    Aagaard-Sørensen, Steffen; Junttila, Juho; Dijkstra, Noortje

    2016-04-01

    Petroleum related exploration activities started in the Barents Sea 1980, reaching 97 exploration wells drilled per January 2013. The biggest operational discharge from drilling operations in the Barents Sea is the release of drill cuttings (crushed seabed and/or bedrock) and water based drilling muds including the commonly used weighing material barite (BaSO4). Barium (Ba), a constituent of barite, does not degrade and can be used to evaluate dispersion and accumulation of drill waste. The environmental impact associated with exploration drilling within the Goliat Field, SW Barents Sea in 2006 was evaluated via a multiproxy investigation of local sediments. The sediments were retrieved in November 2014 at ~350 meters water depth and coring sites were selected at distances of 5, 30, 60, 125 and 250 meters from the drill hole in the eastward downstream direction. The dispersion pattern of drill waste was estimated via measurements of sediment parameters including grain size distribution and water content in addition to heavy metal and total organic carbon contents. The environmental impact was evaluated via micro faunal analysis based on benthic foraminiferal (marine shell bearing protists) fauna composition and concentration changes. Observing the sediment parameters, most notably Ba levels, reveals that dispersion of drill waste was limited to <125 meters from the drill site with drill waste thicknesses decreasing downstream. The abruptness and quantity of drill waste sedimentation initially smothered the foraminiferal fauna at ≤ 30 meters from the drill site, while at a distance of 60 meters, the fauna seemingly survived and bioturbation persisted. Analysis of the live (Nov 2014) foraminiferal fauna reveals a natural species composition at all distances from the drill site within the top sediments (0-5 cm core depth). Furthermore, the fossil foraminiferal fauna composition found within post-impacted top sediment sections, particularly in the cores situated at

  5. 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....

  6. 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.

  7. Banana Regime Neoclassical Ion Heat Flux with Retention of the Field Term in the Linearized Collision Operator

    NASA Astrophysics Data System (ADS)

    Parker, J. B.; Catto, P. J.

    2011-10-01

    The standard calculation of neoclassical ion heat flux in the large aspect ratio, circular flux surface, banana regime limit uses a model collision operator where only pitch angle scattering is retained and an ad hoc term is introduced to preserve conservation of momentum. The full linearized collision operator contains also an energy diffusion term and a complicated field term which involves an integral over the perturbed distribution, both of which are dropped in the standard calculation. We reexamine the standard treatment by considering the field as well as the test particle portions of the linearized collision operator and by using an expansion in the eigenfunctions associated with the transit-averaged pitch angle scattering collision operator. We focus on modifications due to the field term to attempt to determine if corrections are needed to the standard result in the large aspect ratio limit. Work supported by a U.S. DOE FES Fellowship and by U.S. DOE Contract No. DE-FG02-91ER-54109.

  8. A planar diode operating in the regime of limited electron emission

    NASA Astrophysics Data System (ADS)

    Pushkarev, A. I.; Sazonov, R. V.

    2008-04-01

    The current-voltage characteristic of a planar diode with a graphite explosive-emission cathode has been experimentally studied at the initial stage of electron current formation. An analytical expression has been obtained for the total area of discrete emitting centers in the cellular structure approximation, assuming that the number of such emitting centers operative during the current pulse formation is constant. It is shown that the electron current buildup for a cathode surface with discrete emitting centers is satisfactorily described by a modified Child-Langmuir formula with the form factor decreasing from F = 6 to 1.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Inverse model construction for control implementation of macro fiber composite actuators operating in hysteretic regimes

    NASA Astrophysics Data System (ADS)

    Stuebner, Michael; Smith, Ralph C.

    2010-04-01

    Macro Fiber Composite (MFC) actuators utilize PZT fibers embedded in an epoxy matrix for structural actuation. Due to their construction, they are lightweight and provide broadband inputs. Significant advantages of MFC actuators are their high performance, durability, and flexibility when compared to traditional piezoceramic actuators. They are presently being considered for a range of applications including positioning of membrane mirrors and structural control in the aerospace and automotive industry. However, they exhibit varying degrees of hysteresis and constitutive nonlinearities throughout their operating range that must be incorporated in models to achieve the full capabilities of the materials. In this paper, hysteresis is modeled using the homogenized energy model. The inverse model is then used to construct an inverse compensator framework suitable for subsequent control design. The performance of the inverse compensator is illustrated through a numerical example.

  14. Effect of Variation of Operational Regimes in Building Environment on Results of its Energy and Exergy Assessments

    NASA Astrophysics Data System (ADS)

    Voloshchuk, Volodymyr

    2017-03-01

    For further development of the dynamic exergy analysis within built environment the work proposes to take into account stochastic nature of variations of operational regimes. Using the probability theory and statistics methods, the set of parameters considered as relevant for uncertainty conditions are presented. It is shown that characteristics of buildings (insulation, window performance, heat recovery, etc.) and type of the heating system have undoubtedly a strong influence not only on the energy/exergy demand and consumption but also on the sensitivity of the energy/exergy parameters to variations of external conditions. According to the results obtained after implementations of energy efficient solutions coefficient of variation of energy/exergy-based parameters can be increased up to two times.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Environmental and Economic Assessment of Discharges from Gulf of Mexico Region Oil and Gas Operations

    SciTech Connect

    Gettleson, David A

    1999-10-28

    The primary objectives of the project are to increase the base of scientific knowledge concerning (1) the fate and environmental effects of organics, trace metals, and NORM in water, sediment, and biota near several offshore oil and gas facilities; (2) the characteristics of produced water and produced sand discharges as they pertain to organics, trace metals, and NORM variably found in association with the discharges; (3) the recovery of three terminated produced water discharge sites located in wetland and high-energy open bay sites of coastal Louisiana; (4) the economic and energy supply impacts of existing and anticipated federal and state offshore and coastal discharge regulations; and (5) the catch, consumption and human use patterns of seafood species collected from coastal and offshore waters. The products of the effort will be a series of technical reports detailing the study procedures, results, and conclusions which contribute to the transfer of technology to the scientific community, petroleum industry, and state and federal agencies.

  3. 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.

  4. 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.

  5. 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.

  6. Temperature range and conditions of stable operation of gas-discharge rare-earth metal vapor lasers

    NASA Astrophysics Data System (ADS)

    Gerasimov, V. A.; Gerasimov, V. V.; Pavlinskiy, A. V.

    2008-08-01

    We have experimentally studied the temperature range and conditions of the stable operation of rare-earth metal (REM) vapor lasers. Gas-discharge tubes made of alumina (Al2O3-GDTs) were used in the experiments. The lasing appears at the temperature when the saturated-vapor pressure of REMs reaches the value of 0.1 Torr and abruptly drops at the melting temperature of corresponding REM under any excitation conditions. The necessity of protecting film of REM aluminates LnnAlmOk and oxides Ln2O3 on the inner surface of Al2O3-GDT for stable operation of these lasers is shown. An explanation of lasing impossibility in vapors of cerium (Ce), praseodymium (Pr), neodymium (Nd), gadolinium (Gd), and terbium (Tb) under gas-discharge excitation is proposed.

  7. Characteristics of atmospheric-pressure, radio-frequency glow discharges operated with argon added ethanol

    SciTech Connect

    Sun Wenting; Li Guo; Li Heping; Bao Chengyu; Wang Huabo; Zeng Shi; Gao Xing; Luo Huiying

    2007-06-15

    Rf, atmospheric-pressure glow discharge (APGD) plasmas with bare metal electrodes have promising prospects in the fields of plasma-aided etching, thin film deposition, disinfection and sterilization, etc. In this paper, the discharge characteristics are presented for the rf APGD plasmas generated with pure argon or argon-ethanol mixture as the plasma-forming gas and using water-cooled, bare copper electrodes. The experimental results show that the breakdown voltage can be reduced significantly when a small amount of ethanol is added into argon, probably due to the fact that the Penning ionization process is involved, and a pure {alpha}-mode discharge can be produced more easily with the help of ethanol. The uniformity of the rf APGDs of pure argon or argon-ethanol mixtures using bare metallic electrodes is identified with the aid of the intensified charge coupled device images.

  8. 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.

  9. 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.

  10. 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)...

  11. 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)...

  12. 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)...

  13. 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)...

  14. 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)...

  15. 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.

  16. 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.

  17. Role of interactions in an electronic Fabry–Perot interferometer operating in the quantum Hall effect regime

    PubMed Central

    Ofek, Nissim; Bid, Aveek; Heiblum, Moty; Stern, Ady; Umansky, Vladimir; Mahalu, Diana

    2010-01-01

    Interference of edge channels is expected to be a prominent tool for studying statistics of charged quasiparticles in the quantum Hall effect (QHE). We present here a detailed study of an electronic Fabry–Perot interferometer (FPI) operating in the QHE regime [C. Chamon, et al. (1997) Phys Rev B 55:2331–2334], with the phase of the interfering quasiparticles controlled by the Aharonov–Bohm effect. Our main finding is that Coulomb interactions among the electrons dominate the interference, even in a relatively large area FPI, leading to a strong dependence of the area enclosed by the interference loop on the magnetic field. In particular, for a composite edge structure, with a few independent edge channels propagating along the edge, interference of the outmost edge channel (belonging to the lowest Landau level) was insensitive to magnetic field—suggesting a constant enclosed flux. However, when any of the inner edge channels interfered, the enclosed flux decreased when the magnetic field increased. By intentionally varying the enclosed area with a biased metallic gate and observing the periodicity of the interference pattern, charges e (for integer filling factors) and e/3 (for a fractional filling factor) were found to be expelled from the FPI. Moreover, these observations provided also a novel way of detecting the charge of the interfering quasiparticles. PMID:20212147

  18. 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.

  19. Dynamic manipulation of nanomechanical resonators in the high-amplitude regime and non-volatile mechanical memory operation.

    PubMed

    Bagheri, Mahmood; Poot, Menno; Li, Mo; Pernice, Wolfram P H; Tang, Hong X

    2011-10-23

    The ability to control mechanical motion with optical forces has made it possible to cool mechanical resonators to their quantum ground states. The same techniques can also be used to amplify rather than reduce the mechanical motion of such systems. Here, we study nanomechanical resonators that are slightly buckled and therefore have two stable configurations, denoted 'buckled up' and 'buckled down', when they are at rest. The motion of these resonators can be described by a double-well potential with a large central energy barrier between the two stable configurations. We demonstrate the high-amplitude operation of a buckled resonator coupled to an optical cavity by using a highly efficient process to generate enough phonons in the resonator to overcome the energy barrier in the double-well potential. This allows us to observe the first evidence for nanomechanical slow-down and a zero-frequency singularity predicted by theorists. We also demonstrate a non-volatile mechanical memory element in which bits are written and reset by using optomechanical backaction to direct the relaxation of a resonator in the high-amplitude regime to a specific stable configuration.

  20. 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

  1. Tennis elbow surgery - discharge

    MedlinePlus

    Lateral epicondylitis surgery - discharge; Lateral tendinosis surgery - discharge; Lateral tennis elbow surgery - discharge ... Adams JE, Steinmann SP. Elbow tendinopathies and tendon ruptures. In: ... SH, Cohen MS, eds. Green's Operative Hand Surgery . 7th ed. ...

  2. Development of glow discharge plasma-catalytic reactors operated under atmospheric conditions

    SciTech Connect

    Hayashi, Y.; Itoyama, K.; Tanabe, S.; Matsumoto, H.

    1997-12-31

    Two kinds of glow discharge plasma-catalytic reactors, zone discharge tube plasma reactor and rotating electrode ring plasma reactor, have been developed and evaluated in various chemical reactions under atmospheric condition. In the former glow discharge occurs between two electrodes through a dielectric material (Pyrex or quartz tube) and in the latter between a rotating (rotor) and a fixed electrode (stator) to make large volumes of the plasma zone under atmospheric pressure. Each electrode is, furthermore, coated with catalytically active metals, such as Pt, Pd, Rh, Cu or Ni. Various kinds of decomposition reactions of chemically stable compounds have been examined in order to evaluate the performance of these reactors, such as decompositions of CO{sub 2}, H{sub 2}O, NO, CH{sub 4} and Freon into simple molecules. Different characteristic capabilities were observed between these reactors. The conversions of various reactants depend on the input power (voltage, current and frequency), the catalytic metal employed, carrier gas with different metastable level and the flow rate of reactant. In most of the reactions investigated, generally speaking, both reactors showed excellent results in comparison with conventional catalytic reactors.

  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. The design and characteristics of direct current glow discharge atomic emission source operated with plain and hollow cathodes.

    PubMed

    Qayyum, A; Mahmood, M I

    2008-01-07

    A compact direct current glow discharge atomic emission source has been designed and constructed for analytical applications. This atomic emission source works very efficiently at a low-input electrical power. The design has some features that make it distinct from that of the conventional Grimm glow discharge source. The peculiar cathode design offered greater flexibility on size and shape of the sample. As a result the source can be easily adopted to operate in Plain or Hollow Cathode configuration. I-V and spectroscopic characteristics of the source were compared while operating it with plain and hollow copper cathodes. It was observed that with hollow cathode, the source can be operated at a less input power and generates greater Cu I and Cu II line intensities. Also, the intensity of Cu II line rise faster than Cu I line with argon pressure for both cathodes. But the influence of pressure on Cu II lines was more significant when the source is operated with hollow cathode.

  6. Effect of turbine-operating regime and adjustment of automated control system on stability and critical area of surge tanks at HPP

    SciTech Connect

    Murav'ev, O. A.

    2011-05-15

    Materials of the works of several authors who have investigated the effect of turbine-operating regime on the stability of HPP with surge tanks are presented. Anumber of new results are obtained. Analytical relationships that can be used in stability calculations for a number of coefficients are compared with a large amount of actual data.

  7. 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.

  8. Performance of a microwave induced plasma (MIP) operated in a liquid-cooled discharge tube for atomic emission spectrometry

    NASA Astrophysics Data System (ADS)

    Mierzwa, J.; Brandt, R.; Broekaert, J. A. C.; Tschöpel, P.; Tölg, G.

    1996-01-01

    Different types of microwave induced plasma (MIP) discharge operated in liquid-cooled tubes, namely a glass tube of Duran ®, a quartz tube of Herasil ®, and a very simple demountable discharge tube made of glass and quartz have been investigated. The last tube leads to the best analytical properties and the longest lifetime. The intensities of silicon lines and of the continuum spectral background, together with the signal-to-background ratios for B, Ca, Cd, Co and Zn in the case of the pneumatic nebulization of solutions have been measured and used as an indicator for the cooling efficiency. The MIP torch was cooled with a thermostated silicon oil. The decrease of the temperature of the cooling medium causes a measurable decrease of the spectral background intensity. Diagnostic measurements of the plasma include radial profiles of spectral line intensities and excitation temperatures with the lines of Fe I; values of 5000-6000 K are found. The influence of different plasma parameters, e.g. microwave power and helium flow rate, is investigated. The preliminary analytical characterization of a helium MIP maintained with the liquid-cooled demountable discharge tube is presented. Limits of detection for Al, B, Ca, Co, Fe, P, Sb and Zn (between 0.002 and 1.2 μg ml -1) are comparable with or better than those reported for low power helium MIPs with sample introduction in the form of a wet aerosol.

  9. 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.

  10. 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.

  11. Self-stabilized discharge filament in plane-parallel barrier discharge configuration: formation, breakdown mechanism, and memory effects

    NASA Astrophysics Data System (ADS)

    Tschiersch, R.; Nemschokmichal, S.; Bogaczyk, M.; Meichsner, J.

    2017-10-01

    Single self-stabilized discharge filaments were investigated in the plane-parallel electrode configuration. The barrier discharge was operated inside a gap of 3 mm shielded by glass plates to both electrodes, using helium-nitrogen mixtures and a square-wave feeding voltage at a frequency of 2 kHz. The combined application of electrical measurements, ICCD camera imaging, optical emission spectroscopy and surface charge diagnostics via the electro-optic Pockels effect allowed the correlation of the discharge development in the volume and on the dielectric surfaces. The formation criteria and existence regimes were found by systematic variation of the nitrogen admixture to helium, the total pressure and the feeding voltage amplitude. Single self-stabilized discharge filaments can be operated over a wide parameter range, foremost, by significant reduction of the voltage amplitude after the operation in the microdischarge regime. Here, the outstanding importance of the surface charge memory effect on the long-term stability was pointed out by the recalculated spatio-temporally resolved gap voltage. The optical emission revealed discharge characteristics that are partially reminiscent of both the glow-like barrier discharge and the microdischarge regime, such as a Townsend pre-phase, a fast cathode-directed ionization front during the breakdown and radially propagating surface discharges during the afterglow.

  12. Use of state discharge abstract data to identify hospitals performing similar types of operative procedures.

    PubMed

    Wachtel, Ruth E; Dexter, Franklin; Barry, Brian; Applegeet, Carol

    2010-04-01

    A hospital or anesthesia or surgical group that is making decisions to expand its practice benefits from knowledge of the types of surgical procedures performed at other hospitals. Discharge abstract data were used to study 1 hospital in each of 3 states. A similarity index provided information on which other hospitals in each state were competitors and/or peer institutions. To reveal potential growth opportunities, Clinical Classifications Software (CCS) grouping of specific types of procedures into broad categories was combined with the similarity index. The internal Herfindahl index was used to quantify the heterogeneity of procedures within each CCS category. Although the similarity index between many pairs of hospitals was highly influenced by the common orthopedic procedures performed at most hospitals, the similarity index was dominated by a large number of different types of procedures. For some pairs of hospitals, there was considerable overlap between the different types of procedures performed at each institution. For other pairs of hospitals, the overlap was small. Consequently, large hospitals were not always similar to each other because of the wide range of procedures performed. Smaller community hospitals were not always similar to each other either. Some small hospitals were sometimes similar to large metropolitan hospitals. The similarity index is a robust and valid method for quantitatively comparing the numbers and types of inpatient surgical procedures performed at different hospitals. The similarity index, when combined with CCS categories, is useful for identifying opportunities that enable surgeons and anesthesiologists to better meet the needs of their communities.

  13. 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.

  14. 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.

  15. 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

    ... Vessels and Other Non- Recreational Vessels Less Than 79 Feet AGENCY: Environmental Protection Agency (EPA... Operation of Commercial Fishing Vessels and Other Non- Recreational Vessels Less than 79 feet. EPA conducted... vessels less than 79 feet in length. The draft report can be accessed in its entirety at http://www.epa...

  16. 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.

  17. Progress toward fully noninductive discharge operation in DIII-D using off-axis neutral beam injection

    SciTech Connect

    Ferron, J. R.; Luce, T. C.; Politzer, P. A.; Hyatt, A. W.; La Haye, R. J.; Lanctot, M. J.; Petrie, T. W.; Petty, C. C.; Holcomb, C. T.; Park, J. M.; Turco, F.; Hanson, J. M.; Heidbrink, W. W.; Doyle, E. J.; Zeng, L.; In, Y.; Okabayashi, M.

    2013-09-15

    The initial experiments on off-axis neutral beam injection into high noninductive current fraction (f{sub NI}), high normalized pressure (β{sub N}) discharges in DIII-D [J. L. Luxon, Fusion Sci. Technol. 48, 828 (2005)] have demonstrated changes in the plasma profiles that increase the limits to plasma pressure from ideal low-n instabilities. The current profile is broadened and the minimum value of the safety factor (q{sub min}) can be maintained above 2 where the profile of the thermal component of the plasma pressure is found to be broader. The off-axis neutral beam injection results in a broadening of the fast-ion pressure profile. Confinement of the thermal component of the plasma is consistent with the IPB98(y,2) scaling, but global confinement with q{sub min}>2 is below the ITER-89P scaling, apparently as a result of enhanced transport of fast ions. A 0-D model is used to examine the parameter space for f{sub NI}=1 operation and project the requirements for high performance steady-state discharges. Fully noninductive solutions are found with 4<β{sub N}<5 and bootstrap current fraction near 0.5 for a weak shear safety factor profile. A 1-D model is used to show that a f{sub NI}=1 discharge at the top of this range of β{sub N} that is predicted stable to n=1, 2, and 3 ideal MHD instabilities is accessible through further broadening of the current and pressure profiles with off-axis neutral beam injection and electron cyclotron current drive.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Device-quality SiO 2 films on InP and Si obtained by operating the pyrolytic CVD reactor in the retardation regime

    NASA Astrophysics Data System (ADS)

    Lakhani, Amir A.

    1984-10-01

    A cold wall atmospheric pressure Chemical Vapor Deposition (CVD) reactor was used to deposit films of SiO 2 at 250°C on n-InP and p-Si substrates. By varying the ratio of oxygen to silane flow rates, the reactor was operated in both the reaction rate controlled and retardation regimes. The insulator-semiconductor interface was evaluated with the aid of high frequency and quasi-static C- V curves. Films deposited on Si in the retardation regime with O 2:SiH 4 = 6 had lowest Qss of 5.8 × 10 11 cm -2 and minimum fast surface state density of 1 × 10 11cm-2eV-1. C- V curves on InP had a hysteresis of 0.5 V, a well defined dip in the quasi-static curve and the accumulation capacitance exhibited no frequency dispersion.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Extension of operational regime in high-temperature plasmas and effect of ECRH on ion thermal transport in the LHD

    NASA Astrophysics Data System (ADS)

    Takahashi, H.; Nagaoka, K.; Murakami, S.; Osakabe, M.; Nakano, H.; Ida, K.; Tsujimura, T. I.; Kubo, S.; Kobayashi, T.; Tanaka, K.; Seki, R.; Takeiri, Y.; Yokoyama, M.; Maeta, S.; Nakata, M.; Yoshinuma, M.; Yamada, I.; Yasuhara, R.; Ido, T.; Shimizu, A.; Tsuchiya, H.; Tokuzawa, T.; Goto, M.; Oishi, T.; Morita, S.; Suzuki, C.; Emoto, M.; Tsumori, K.; Ikeda, K.; Kisaki, M.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Makino, R.; Seki, T.; Kasahara, H.; Saito, K.; Kamio, S.; Nagasaki, K.; Mutoh, T.; Kaneko, O.; Morisaki, T.; the LHD Experiment Group

    2017-08-01

    A simultaneous high ion temperature (T i) and high electron temperature (T e) regime was successfully extended due to an optimized heating scenario in the LHD. Such high-temperature plasmas were realized by the simultaneous formation of an electron internal transport barrier (ITB) and an ion ITB by the combination of high power NBI and ECRH. Although the ion thermal confinement was degraded in the plasma core with an increase of T e/T i by the on-axis ECRH, it was found that the ion thermal confinement was improved at the plasma edge. The normalized ion thermal diffusivity {χ\\text{i}}/T\\text{i}1.5 at the plasma edge was reduced by 70%. The improvement of the ion thermal confinement at the edge led to an increase in T i in the entire plasma region, even though the core transport was degraded.

  14. Simulation of toluene decomposition in a pulse-periodic discharge operating in a mixture of molecular nitrogen and oxygen

    SciTech Connect

    Trushkin, A. N.; Kochetov, I. V.

    2012-05-15

    The kinetic model of toluene decomposition in nonequilibrium low-temperature plasma generated by a pulse-periodic discharge operating in a mixture of nitrogen and oxygen is developed. The results of numerical simulation of plasma-chemical conversion of toluene are presented; the main processes responsible for C{sub 6}H{sub 5}CH{sub 3} decomposition are identified; the contribution of each process to total removal of toluene is determined; and the intermediate and final products of C{sub 6}H{sub 5}CH{sub 3} decomposition are identified. It was shown that toluene in pure nitrogen is mostly decomposed in its reactions with metastable N{sub 2}(A{sub 3}{Sigma}{sub u}{sup +}) and N{sub 2}(a Prime {sup 1}{Sigma}{sub u}{sup -}) molecules. In the presence of oxygen, in the N{sub 2} : O{sub 2} gas mixture, the largest contribution to C{sub 6}H{sub 5}CH{sub 3} removal is made by the hydroxyl radical OH which is generated in this mixture exclusively due to plasma-chemical reactions between toluene and oxygen decomposition products. Numerical simulation showed the existence of an optimum oxygen concentration in the mixture, at which toluene removal is maximum at a fixed energy deposition.

  15. Field application of selective precipitation for recovering Cu and Zn in drainage discharged from an operating mine.

    PubMed

    Oh, Chamteut; Han, Young-Soo; Park, Jin Hee; Bok, Songmin; Cheong, Youngwook; Yim, Giljae; Ji, Sangwoo

    2016-07-01

    Acid mine drainage (AMD) generated from mining activities has been recognized as a serious problem due to its increased acidity and high concentration of heavy metals. In this research, a feasibility test of the selective precipitation (SP) process was performed using AMD discharged from a currently operating mine in Korea for the purpose of minimizing the environmental impact of AMD. For the SP process, a pilot scale equipment (100L reaction tank) was used in field and among various metals, Cu and Zn were the target metals. Through the research, it was confirmed that AMD from an operating mine has two disadvantages of being applied to the SP: altering water quality and unexpected inclusion of clay debris. Despite unfavorable conditions, Cu and Zn precipitate of 80% purity with 90% precipitation rate was able to be obtained from 1.4L/min (2.0tons/day) AMD. The recovered precipitates were identified as amorphous CuS and ZnS with small amounts of impurities (Si minerals, CuFeS2, and Fe/Al hydroxide). The strategies to reduce these impurities were also discussed. Recovery rate, which is the amount of precipitate collected per unit volume of AMD, was proposed as an indicator to evaluate the working efficiency of the SP process. It was confirmed that the recovery rate was strongly dependent on flow rate and dose of coagulant. The results of this study may be helpful in reducing the potential complications which occurs when SP is applied on field. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Droplet formation in microfluidic T-junction generators operating in the transitional regime. III. Dynamic surfactant effects.

    PubMed

    Glawdel, Tomasz; Ren, Carolyn L

    2012-08-01

    This study extends our previous work on droplet generation in microfluidic T-junction generators to include dynamic interfacial tension effects created by the presence of surfactants. In Paper I [T. Glawdel, C. Elbuken, and C. L. Ren, Phys. Rev. E 85, 016322 (2012)], we presented experimental findings regarding the formation process in the squeezing-to-transition regime, and in Paper II [T. Glawdel, C. Elbuken, and C. L. Ren, Phys. Rev. E 85, 016323 (2012)] we developed a theoretical model that describes the performance of T-junction generators without surfactants. Here we study dynamic interfacial tension effects for two surfactants, one with a small molecular weight that adsorbs quickly, and the other with a large molecular weight that adsorbs slowly. Using the force balance developed in Paper II we extract the dynamic interfacial tension from high speed videos obtained during experiments. We then develop a theoretical model to predict the dynamic interfacial tension in microfluidic T-junction generators as a function of the surfactant properties, flow conditions, and generator design. This model is then incorporated into the overall model for generator performance to effectively predict the size of droplets produced when surfactants are present.

  17. 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

    ...′ N 82°44′ W 44°54′ N 82°40′ W Sleeping Bear Dunes National Lakeshore means the site on or near Lake... exclusively within Western Basin may discharge limestone or clean stone cargo residues over the dredged..., except that a vessel may discharge residue over the dredged navigation channels between Toledo...

  18. 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

    ...′ N 82°44′ W 44°54′ N 82°40′ W Sleeping Bear Dunes National Lakeshore means the site on or near Lake... exclusively within Western Basin may discharge limestone or clean stone cargo residues over the dredged..., except that a vessel may discharge residue over the dredged navigation channels between Toledo...

  19. 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

    ...′ N 82°44′ W 44°54′ N 82°40′ W Sleeping Bear Dunes National Lakeshore means the site on or near Lake... exclusively within Western Basin may discharge limestone or clean stone cargo residues over the dredged..., except that a vessel may discharge residue over the dredged navigation channels between Toledo...

  20. 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.

  1. 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.

  2. Supporting inland waterway transport on German waterways by operational forecasting services - water-levels, discharges, river ice

    NASA Astrophysics Data System (ADS)

    Meißner, Dennis; Klein, Bastian; Ionita, Monica; Hemri, Stephan; Rademacher, Silke

    2017-04-01

    Inland waterway transport (IWT) is an important commercial sector significantly vulnerable to hydrological impacts. River ice and floods limit the availability of the waterway network and may cause considerable damages to waterway infrastructure. Low flows significantly affect IWT's operation efficiency usually several months a year due to the close correlation of (low) water levels / water depths and (high) transport costs. Therefore "navigation-related" hydrological forecasts focussing on the specific requirements of water-bound transport (relevant forecast locations, target parameters, skill characteristics etc.) play a major role in order to mitigate IWT's vulnerability to hydro-meteorological impacts. In light of continuing transport growth within the European Union, hydrological forecasts for the waterways are essential to stimulate the use of the free capacity IWT still offers more consequently. An overview of the current operational and pre-operational forecasting systems for the German waterways predicting water levels, discharges and river ice thickness on various time-scales will be presented. While short-term (deterministic) forecasts have a long tradition in navigation-related forecasting, (probabilistic) forecasting services offering extended lead-times are not yet well-established and are still subject to current research and development activities (e.g. within the EU-projects EUPORIAS and IMPREX). The focus is on improving technical aspects as well as on exploring adequate ways of disseminating and communicating probabilistic forecast information. For the German stretch of the River Rhine, one of the most frequented inland waterways worldwide, the existing deterministic forecast scheme has been extended by ensemble forecasts combined with statistical post-processing modules applying EMOS (Ensemble Model Output Statistics) and ECC (Ensemble Copula Coupling) in order to generate water level predictions up to 10 days and to estimate its predictive

  3. 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.

  4. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Pulse Operation of Chemical Oxygen-Iodine Laser by Pulsed Gas Discharge with the Assistance of Spark Pre-ionization

    NASA Astrophysics Data System (ADS)

    Li, Guo-Fu; Yu, Hai-Jun; Duo, Li-Ping; Jin, Yu-Qi; Wang, Jian; Sang, Feng-Ting; Fang, Ben-Jie; Wang, De-Zhen

    2009-11-01

    The continuous wavelength chemical oxygen-iodine laser can be turned into pulse operation mode in order to obtain high energy and high pulse power. We propose an approach to produce iodine atoms instantaneously by pulsed gas discharge with the assistance of spark pre-ionization to achieve the pulsed goal. The influence of spark pre-ionization on discharge homogeneity is discussed. Voltage-current characteristics are shown and discussed in existence of the pre-ionization capacitor and peaking capacitor. The spark pre-ionization and peaking capacitor are very helpful in obtaining a stable and homogeneous discharge. The lasing is achieved at the total pressure of 2.2-2.9kPa and single pulse energy is up to 180 mJ, the corresponding specific output energy is 1.0 J/L.

  5. 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.

  6. Impact of an inter-basin water transfer and reservoir operation in karst on the hydrological regime: the example of the Sabljaki and Bukovik reservoirs (Croatia)

    NASA Astrophysics Data System (ADS)

    Bonacci, Ognjen; Andrić, Ivo; Oskoruš, Dijana

    2010-05-01

    The Sabljaki reservoir in the Zagorska Mrežnica River and the Bukovik reservoir in the Upper Dobra River began operation in 1959. Both are part of the hydroelectric power plant (HEPP) Gojak. Their water volumes at the spillway altitude of 320.10 m a. s. l. and 320.15 m a. s. l. is 3.3 × 106 m3 and 0.24 × 106 m3 respectively. Water from the Sabljaki reservoir is provided by 9376 m long tunnel to the HEPP Gojak constructed in the neighboring Lower Dobra River. The Sabljaki reservoir is located in the Mrežnica karst polje while the Bukovik reservoir is located in the neighboring Ogulin karst polje. The consequence of the inter-basin water transfer is strong and abrupt change of hydrological regime on the downstream parts of both rivers. At the same time construction and development of the both reservoirs caused hydrological changes on the upstream part of the Upper Dobra River. The both Dobra and Mrežnica Rivers are at the same time losing, sinking and underground karst rivers. The presentation describes hydrological changes caused by inter-basin water transfer and the reservoirs development on the hydrological regime on the both rivers.

  7. Transition from open access to quota based fishery management regimes in Alaska increased the safety of operations.

    PubMed

    Hughes, Steven E; Woodley, Christopher

    2007-01-01

    During the past 12 years fishery managers responsible for federal fisheries off Alaska have developed and implemented three new fishery management limited access/quota share programs in place of traditional open access management. The three limited access programs are unique but each provides for the allocation of quota shares to individual participants in the halibut and sablefish longline fishery, in the Bering Sea pollock trawl fishery and in the Bering Sea king and Tanner crab fishery, respectively. New management programs are briefly described and contrasted with traditional management. For each of the three fisheries, management changes over time have generated substantial changes in fishing fleets, their operations, crew employment, economics and safety records. Under quota share management, fleet consolidations have occurred, particularly in the more over capitalized fisheries. The intense speed and inflexible timing associated with open access fisheries have greatly lessened as have the risk taking and incentives to maximize fishing power. Active vessel economic viability has strengthened due to a combination of increased efficiency, higher product yields, reduced costs, greater crew stability and safer operations.

  8. 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. ...

  9. Ear discharge

    MedlinePlus

    ... health care provider if: The discharge is white, yellow, clear, or bloody. The discharge is the result of an injury. The discharge has lasted more than 5 days. There is severe pain. The discharge is ...

  10. 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

  11. 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.

  12. 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%.

  13. Numerical modeling of a table-top tunable Smith-Purcell terahertz free-electron laser operating in the super-radiant regime

    SciTech Connect

    Prokop, C.; Piot, P.; Lin, M. C.; Stoltz, P.

    2010-04-12

    Terahertz (THz) radiation occupies a very large portion of the electromagnetic spectrum and has generated much recent interest due to its ability to penetrate deep into many organic materials without the damage associated with ionizing radiation such as x-rays. One path for generating copious amount of tunable narrow-band THz radiation is based on the Smith-Purcell free-electron laser (SPFEL) effect. In this paper we propose a simple concept for a compact two-stage tunable SPFEL operating in the super-radiant regime capable of radiating at the fundamental bunching frequency. We demonstrate its capabilities and performances using the conformal finite-difference time-domain electromagnetic solver VORPAL.

  14. 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

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

    PubMed

    Hughes, David; Allen, Pauline; Doheny, Shane; Petsoulas, Christina; Vincent-Jones, Peter

    2013-01-01

    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 1990 s 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. 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. 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. The interdependency of local

  16. Subwavelength imaging at optical frequencies using a transmission device formed by a periodic layered metal-dielectric structure operating in the canalization regime

    NASA Astrophysics Data System (ADS)

    Belov, Pavel A.; Hao, Yang

    2006-03-01

    Imaging with subwavelength resolution using a periodic metal-dielectric layered structure is demonstrated. The structure operates in canalization regime as a transmission device and it does not involve negative refraction and amplification of evanescent modes. The thickness of the structure has to be an integer number of half-wavelengths and can be made as large as required for ceratin applications, in contrast to the solid metallic slabs operating with subwavelength resolution which have to be much thinner than the wavelength. Resolution of λ/20 at 600nm wavelength is confirmed by numerical simulation for a 300nm thick structure formed by a periodic stack of 10nm layers of glass with ɛ=2 and 5nm layers of metal-dielectric composite with ɛ=-1 . Resolution of λ/60 is predicted for a structure with same thickness, period and operating frequency, but formed by 7.76nm layers of silicon with ɛ=15 and 7.24nm layers of silver with ɛ=-14 .

  17. 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.

  18. Alfvén Instabilities Excited by Energetic Particles in a Parameter Regime Similar to EAST Operation

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Hu, Chundong; Hu, Shuanghui; Wu, Bin; Ding, Siye

    2013-08-01

    The kinetic excitation of ideal magnetohydrodynamic (MHD) Alfvén instabilities is investigated for operations at the EAST tokamak. The instabilities include α-induced toroidal Alfvén eigenmodes (αTAE here, α = -q2Rdβ/dr, with q being the safety factor, β the ratio between the plasma and magnetic pressures, R the major radius, and r the minor radius), toroidicity-induced Alfvén eigenmodes (TAE), and the energetic particle continuum mode (EPM). The αTAE, trapped by α-induced potential wells along the magnetic field line, can be readily destabilized by energetic particles due to negligible continuum damping via wave energy tunneling. It is shown for the geometry and the parameters similar to those of the EAST equilibrium that αTAE is different not only from the EPM by the potential-well determined frequency, but also from the TAE by the broad frequency spectrum outside the toroidal frequency gap.

  19. 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.

  20. Transition from diffuse to self-organized discharge in a high frequency dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Belinger, Antoine; Naudé, Nicolas; Gherardi, Nicolas

    2017-05-01

    Depending on the operating conditions, different regimes can be obtained in a dielectric barrier discharge (DBD): filamentary, diffuse (also called homogeneous) or self-organized. For a plane-to-plane DBD operated at high frequency (160 kHz) and at atmospheric pressure in helium gas, we show that the addition of a small amount of nitrogen induces a transition from the diffuse regime to a self-organized regime characterized by the appearance of filaments at the exit of the discharge. In this paper, we detail mechanisms that could be responsible of the transition from diffuse mode to this self-organized mode. We point out the critical role of the power supply and the importance of the gas memory effect from one discharge to the following one on the transition to the self-organised mode. The self-organized mode is usually attributed to a surface memory effect. In this work, we show an additional involvement of the gas memory effect on the self-organized mode. Contribution to the topical issue "The 15th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XV)", edited by Nicolas Gherardi and Tomáš Hoder

  1. 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.

  2. 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.

  3. 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.

  4. Environmental and economic assessment of discharges from Gulf of Mexico region oil and gas operations. Quarterly technical progress report, April 1995--June 1995

    SciTech Connect

    Gettleson, D.A.

    1995-07-31

    Progress is described on the determination of environmental impacts from waste discharges to the aquatic ecosystems from oil and gas operations. Task 2 (Preparation of the Sampling and Analysis Plan) activities involved revisions and additions to the Sampling and Analysis Plan. Task 3 (Environmental Field Sampling and Analysis of NORM, Heavy Metals, and Organics) work included analyses of water, sediment, and tissue samples as well as data management. Task 4 (Monitoring of the Recovery of Impacted Wetland and Open Bay Produced Water Discharge Sites in Coastal Louisiana and Texas) activities involved the continued analyses of samples and conducting field sampling at Bay de Chene. Task 5 (Assessment of Economic Impacts of Offshore and Coastal Discharge Requirements on Present and Future Operations in the Gulf of Mexico Region) activities included preparing a draft final report and review by the Scientific Review Committee (SRC). Task 6 (Synthesis of Gulf of Mexico Seafood Consumption and Use Patterns) work involved the preparation of the draft final report and review by the SRC. Task 7 (Technology Transfer Plan) activities involved the presentation of four papers. Task 8 (Project Management and Deliverables) activities involved the submission of the necessary reports and routine management.

  5. Trade-off analysis of discharge-desiltation-turbidity and ANN analysis on sedimentation of a combined reservoir-reach system under multi-phase and multi-layer conjunctive releasing operation

    NASA Astrophysics Data System (ADS)

    Huang, Chien-Lin; Hsu, Nien-Sheng; Wei, Chih-Chiang; Yao, Chun-Hao

    2017-10-01

    Multi-objective reservoir operation considering the trade-off of discharge-desiltation-turbidity during typhoons and sediment concentration (SC) simulation modeling are the vital components for sustainable reservoir management. The purposes of this study were (1) to analyze the multi-layer release trade-offs between reservoir desiltation and intake turbidity of downstream purification plants and thus propose a superior conjunctive operation strategy and (2) to develop ANFIS-based (adaptive network-based fuzzy inference system) and RTRLNN-based (real-time recurrent learning neural networks) substitute SC simulation models. To this end, this study proposed a methodology to develop (1) a series of multi-phase and multi-layer sediment-flood conjunctive release modes and (2) a specialized SC numerical model for a combined reservoir-reach system. The conjunctive release modes involve (1) an optimization model where the decision variables are multi-phase reduction/scaling ratios and the timings to generate a superior total release hydrograph for flood control (Phase I: phase prior to flood arrival, Phase II/III: phase prior to/subsequent to peak flow) and (2) a combination method with physical limitations regarding separation of the singular hydrograph into multi-layer release hydrographs for sediment control. This study employed the featured signals obtained from statistical quartiles/sediment duration curve in mesh segmentation, and an iterative optimization model with a sediment unit response matrix and corresponding geophysical-based acceleration factors, for efficient parameter calibration. This research applied the developed methodology to the Shihmen Reservoir basin in Taiwan. The trade-off analytical results using Typhoons Sinlaku and Jangmi as case examples revealed that owing to gravity current and re-suspension effects, Phase I + II can de-silt safely without violating the intake's turbidity limitation before reservoir discharge reaches 2238 m3/s; however

  6. 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

    ...′ W 44°51.0′ N, 082°44.0′ W 44°53.0′ N, 082°44.0′ W 44°54.0′ N, 082°40.0′ W. Sleeping Bear Dunes... cargo residues over the dredged navigation channels between Toledo Harbor Light and Detroit River Light... Refuge; prohibited in Western Basin, except that a vessel may discharge residue over the...

  7. 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

    ...°17′ N 82°30′ W 44°28′ N 82°40′ W 44°51′ N 82°44′ W 44°53′ N 82°44′ W 44°54′ N 82°40′ W Sleeping Bear... limestone or clean stone cargo residues over the dredged navigation channels between Toledo Harbor Light and... International Wildlife Refuge; prohibited in Western Basin, except that a vessel may discharge residue over...

  8. ICU Admission, Discharge, and Triage Guidelines: A Framework to Enhance Clinical Operations, Development of Institutional Policies, and Further Research.

    PubMed

    Nates, Joseph L; Nunnally, Mark; Kleinpell, Ruth; Blosser, Sandralee; Goldner, Jonathan; Birriel, Barbara; Fowler, Clara S; Byrum, Diane; Miles, William Scherer; Bailey, Heatherlee; Sprung, Charles L

    2016-08-01

    To update the Society of Critical Care Medicine's guidelines for ICU admission, discharge, and triage, providing a framework for clinical practice, the development of institutional policies, and further research. An appointed Task Force followed a standard, systematic, and evidence-based approach in reviewing the literature to develop these guidelines. The assessment of the evidence and recommendations was based on the principles of the Grading of Recommendations Assessment, Development and Evaluation system. The general subject was addressed in sections: admission criteria and benefits of different levels of care, triage, discharge timing and strategies, use of outreach programs to supplement ICU care, quality assurance/improvement and metrics, nonbeneficial treatment in the ICU, and rationing considerations. The literature searches yielded 2,404 articles published from January 1998 to October 2013 for review. Following the appraisal of the literature, discussion, and consensus, recommendations were written. Although these are administrative guidelines, the subjects addressed encompass complex ethical and medico-legal aspects of patient care that affect daily clinical practice. A limited amount of high-quality evidence made it difficult to answer all the questions asked related to ICU admission, discharge, and triage. Despite these limitations, the members of the Task Force believe that these recommendations provide a comprehensive framework to guide practitioners in making informed decisions during the admission, discharge, and triage process as well as in resolving issues of nonbeneficial treatment and rationing. We need to further develop preventive strategies to reduce the burden of critical illness, educate our noncritical care colleagues about these interventions, and improve our outreach, developing early identification and intervention systems.

  9. Environmental and economic assessment of discharges from Gulf of Mexico region oil and gas operations. Quarterly technical progress report, April--June 1993

    SciTech Connect

    Gettleson, D.A.

    1993-07-26

    Continental Shelf Associates, Inc. (CSA) was contracted to conduct a three-year study of the environmental and health related impacts of produced water and sand discharges from oil and gas operations. Data on naturally occurring radioactive materials (NORM), heavy metals, and hydrocarbons in water, sediment, and biota will be collected and evaluated. Health related impacts will be studied through field collections and analyses of commercially- and recreationally-important fish and shellfish tissues. Additionally, information on seafood catch, consumption, and use patterns for the Gulf of Mexico will be gathered and analyzed. The facilities to be studied will include both offshore and coastal facilities in the Gulf of Mexico. Coastal sites will be additionally studied to determine ecological recovery of impacted wetland and open bay areas. The economic impact of existing and proposed effluent federal and state regulations will also be evaluated. The primary objectives of the project are to increase the base of scientific knowledge concerning (1) the fate and environmental effects of organics, trace metals, and NORM in water, sediment, and biota near several offshore oil and gas facilities; (2) the characteristics of produced water and produced sand discharges as they pertain to organics, trace metals, and NORM variably found in association with the discharges; (3) the recovery of four terminated produced water discharge sites located in wetland and high-energy open bay sites of coastal Louisiana and Texas; (4) the economic and energy supply impacts of existing and anticipated federal and state offshore and coastal discharge regulations; and (5) the catch, consumption and human use patterns of seafood species collected from coastal and offshore waters. Accomplishments for this period are described.

  10. Environmental and economic assessment of discharges from Gulf of Mexico Region oil and gas operation. Quarterly technical progress report, 1 October--31 December 1994

    SciTech Connect

    Gettleson, D.A.

    1995-01-18

    Task 3 (Environmental Field Sampling and Analysis of NORM, Heavy Metals, and Organics) work included analyses of samples. Task 4 (Monitoring of the Recovery of Impacted Wetland and Open Bay Produced Water Discharge Sites in Coastal Louisiana and Texas) activities involved the continued analyses of samples and field sampling at Bay de Chene. Task 5 (Assessment of Economic Impacts of Offshore and Coastal Discharge Requirements on Present and Future Operations in the Gulf of Mexico Region) activities included preparing a draft final report. Task 6 (Synthesis of Gulf of Mexico Seafood Consumption and Use Patterns) work also involved preparing a draft final report. Task 7 (Technology Transfer Plan) activities included a presentation at the Minerals Management Service Information Transfer Meeting for the Gulf of Mexico OCS Region. Task 8 (Project Management and Deliverables) activities involved the submission of the necessary reports and routine management.

  11. 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

  12. Hysterectomy - laparoscopic - discharge

    MedlinePlus

    Supracervical hysterectomy - discharge; Removal of the uterus - discharge; Laparoscopic hysterectomy - discharge; Total laparoscopic hysterectomy - discharge; TLH - discharge; Laparoscopic supracervical ...

  13. Radical prostatectomy - discharge

    MedlinePlus

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

  14. 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.

  15. Flow regime mapping: outcome, or pre-requisite of tracer tests? (from the standpoint of deep-georeservoir characterization, development, operation, and monitoring)

    NASA Astrophysics Data System (ADS)

    Ghergut, Julia; Behrens, Horst; Sauter, Martin

    2017-04-01

    Tracer tests in deep-subsurface flow usually yield fluid residence time distributions (RTD) for a sparse selection of fluid spiking and fluid sampling points. Such RTD can be explained more or less adequately assuming certain flow and transport boundary conditions, and a fractured-porous void-space structure in which advective-dispersive transport and possibly partitioning/reactions at interfaces take place. Yet RTD do not by themselves enable to tell 'where' a flow process is taking place. So to say, "to trace is not to track", and 'tracking' would require some complementary kind of mapping, imaging, or monitoring - additionally to the metering of tracer fluxes at the few accessible 'places' in the georeservoir (i. e., deep boreholes) at which fluids can be sampled. We do not feel the need for such 'tracking' capability, when tracer-based RTD are used to predict the thermal lifetime of, say, a geothermal well doublet. However, the ability to 'locate' flow and transport processes (in both space and time) may become critical when facing environmental impacts of deep-georeservoir operation, and liabilities associated with these. On the other hand, it can also be a primary task in reservoir diagnostics and engineering, for instance when facing the question of whether and where to re-frac (in unconventional reservoir development). The poster describes three paradigm settings where a complementary, non-fluid-borne mapping of flow regimes (or at least of flow regime contrasts) appears as a very sensible, if not indispensable counterpart to tracer-based RTD for predicting (or accounting for) deep-georeservoir behavior. These are illustrated with (a) inter-well tracings of geothermally exploited Malm aquifers beneath the Munich metropolitan area, in analogy to past work conducted by Seiler et al. (1989) in the Franconian Alb; (b) single-well spikings of petrothermal or aquifer-based EGS in the N-German sedimentary basin, with two major issues left unresolved by Ghergut et

  16. 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.

  17. 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)

  18. Operating room discharge after deep neuromuscular block reversed with sugammadex compared with shallow block reversed with neostigmine: a randomized controlled trial.

    PubMed

    Putz, Laurie; Dransart, Christophe; Jamart, Jacques; Marotta, Maria-Laura; Delnooz, Geraldine; Dubois, Philippe E

    2016-12-01

    To determine if reversing a deep or moderate block with sugammadex, compared with a shallow block reversed with neostigmine, reduces the time to operating room discharge after surgery and the time spent in the postanesthesia care unit. A randomized controlled trial. Monocentric study performed from February 2011 until May 2012. One hundred consenting women with American Society of Anesthesiologists grade I or II were randomized into 2 groups. Laparoscopic hysterectomy was performed under desflurane general anesthesia. For the neostigmine (N) group, 0.45 mg · kg(-1) rocuronium was followed by spontaneous recovery. A 5-mg rescue bolus was administered only if surgical evaluation was unacceptable. At the end of surgery, 50 μg · kg(-1) neostigmine with glycopyrrolate was administered. For the sugammadex (S) group, a higher intubating rocuronium dose (0.6 mg · kg(-1)) was followed by 5-mg boluses each time the train-of-four count exceeded 2. Sugammadex (2-4 mg · kg(-1)) was administered to reverse the block. All patients were extubated after obtaining a train-of-four ratio of 0.9. The duration between the end of surgery and operating room discharge and the time spent in the postanesthesia care unit. The time till operating room discharge was shorter and more predictable in group S (9.15±4.28 minutes vs 13.87±11.43 minutes in group N; P=.005). The maximal duration in group S was 22 minutes, compared with 72 minutes in group N. The time spent in the postanesthesia care unit was not significantly different (group S: 47.75±31.77 minutes and group N: 53.43±40.57 minutes; P=.543). Maintaining a deep neuromuscular block during laparoscopic hysterectomy reversed at the end of the procedure with sugammadex enabled a faster and more predictable time till operating room discharge than did the classical combination of a shallower block reversed with neostigmine. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. 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.

  20. 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.

  1. Environmental and economic assessment of discharges from Gulf of Mexico region oil and gas operations. Quarterly technical progress report, July--September 1995

    SciTech Connect

    Gettleson, D.A.

    1995-10-31

    Continental Shelf Associates, Inc. (CSA) was contracted to conduct a three-year study of the environmental and health related impacts of produced water and sand discharges from oil and gas operations. Data on naturally occurring radioactive materials (NORM), heavy metals, and hydrocarbons in water, sediment, and biota will be collected and evaluated. Health related impacts will be studied through field collections and analyses of commercially- and recreationally-important fish and shellfish tissues. Additionally, information on seafood catch, consumption, and use patterns for the Gulf of Mexico will be gathered and analyzed. The facilities to be studied will include both offshore and coastal facilities in the Gulf of Mexico. Coastal sites will be additionally studied to determine ecological recovery of impacted wetland and open bay areas. The economic impact of existing and proposed effluent federal and state regulations will also be evaluated. This report represents the thirteenth quarterly technical summary for the study ``Environmental and Economic Assessment of Discharges from Gulf of Mexico Region Oil and Gas Operations.`` Activities associated with Tasks 3 through 8 are discussed in this report.

  2. 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.

  3. 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.

  4. Burning plasma regime for Fussion-Fission Research Facility

    NASA Astrophysics Data System (ADS)

    Zakharov, Leonid E.

    2010-11-01

    The basic aspects of burning plasma regimes of Fusion-Fission Research Facility (FFRF, R/a=4/1 m/m, Ipl=5 MA, Btor=4-6 T, P^DT=50-100 MW, P^fission=80-4000 MW, 1 m thick blanket), which is suggested as the next step device for Chinese fusion program, are presented. The mission of FFRF is to advance magnetic fusion to the level of a stationary neutron source and to create a technical, scientific, and technology basis for the utilization of high-energy fusion neutrons for the needs of nuclear energy and technology. FFRF will rely as much as possible on ITER design. Thus, the magnetic system, especially TFC, will take advantage of ITER experience. TFC will use the same superconductor as ITER. The plasma regimes will represent an extension of the stationary plasma regimes on HT-7 and EAST tokamaks at ASIPP. Both inductive discharges and stationary non-inductive Lower Hybrid Current Drive (LHCD) will be possible. FFRF strongly relies on new, Lithium Wall Fusion (LiWF) plasma regimes, the development of which will be done on NSTX, HT-7, EAST in parallel with the design work. This regime will eliminate a number of uncertainties, still remaining unresolved in the ITER project. Well controlled, hours long inductive current drive operation at P^DT=50-100 MW is predicted.

  5. Battery-Operated Atomic Emission Analyzer for Waterborne Arsenic Based on Atmospheric Pressure Glow Discharge Excitation Source.

    PubMed

    Yang, Chun; He, Dong; Zhu, Zhenli; Peng, Huan; Liu, Zhifu; Wen, Guojun; Bai, Jianghao; Zheng, Hongtao; Hu, Shenghong; Wang, Yanxin

    2017-03-21

    In this paper, a sensitive atomic emission spectrometer (AES) based on a new low power and low argon consumption (<8 W, 100 mL min(-1)) miniature direct current (dc) atmospheric pressure glow discharge (APGD) plasma (3 mm × 5 mm) excitation source was developed for the determination of arsenic in water samples. In this method, arsenic in water was reduced to AsH3 by hydride generation (HG), which was then transported to the APGD source for excitation and detected by a compact CCD (charge-coupled device) microspectrometer. Different parameters affecting the APGD and the hydride generation reactions were investigated. The detection limit for arsenic with the proposed APGD-AES was 0.25 μg L(-1), and the calibration curves were found to be linear up to 3 orders of magnitude. The proposed method was successfully applied to the determination of certified reference material (GBW08605), tap water, pond water, groundwater, and hot spring samples. Measurements from the APGD analyzer showed good agreement with the certified value/values obtained with well-established hydride generation atomic fluorescence spectrometry (HG-AFS). These results suggest that the developed robust, cost-effective, and fast analyzer can be used for field based arsenic determination and may provide an important tool for arsenic contamination and remediation programs.

  6. 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 ...

  7. After-discharges and seizures during pediatric extra-operative electrical cortical stimulation functional brain mapping: Incidence, thresholds, and determinants.

    PubMed

    Aungaroon, Gewalin; Zea Vera, Alonso; Horn, Paul S; Byars, Anna W; Greiner, Hansel M; Tenney, Jeffrey R; Arthur, Todd M; Crone, Nathan E; Holland, Katherine D; Mangano, Francesco T; Arya, Ravindra

    2017-10-01

    This study examined the incidence, thresholds, and determinants of electrical cortical stimulation (ECS)-induced after-discharges (ADs) and seizures. Electrocorticograph recordings were reviewed to determine incidence of ECS-induced ADs and seizures. Multivariable analyses for predictors of AD/seizure occurrence and their thresholds were performed. In 122 patients, the incidence of ADs and seizures was 77% (94/122) and 35% (43/122) respectively. Males (odds ratio [OR] 2.92, 95% CI 1.21-7.38, p=0.02) and MRI-negative patients (OR 3.69, 95% CI 1.24-13.7, p=0.03) were found to have higher odds of ECS-induced ADs. A significant trend for decreasing AD thresholds with age was seen (regression co-efficient -0.151, 95% CI -0.267 to -0.035, p=0.011). ECS-induced seizures were more likely in patients with lateralized functional imaging (OR 6.62, 95% CI 1.36-55.56, p=0.036, for positron emission tomography) and presence of ADs (OR 3.50, 95% CI 1.12-13.36, p=0.043). ECS is associated with a high incidence of ADs and seizures. With age, current thresholds decrease and the probability for AD/seizure occurrence increases. ADs and seizures during ECS brain mapping are potentially hazardous and affect its functional validity. Thus, safer method(s) for brain mapping with improved neurophysiologic validity are desirable. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  8. Environmental and economic assessment of discharges from Gulf of Mexico Region oil and gas operations. Quarterly technical progress report, 1 October--31 December 1992

    SciTech Connect

    Gettleson, D.A.

    1993-01-18

    Tasks 3 (Environmental Field Sampling and Analysis of naturally occurring radioactive materials (NORM), Heavy Metals, and Organics) and 4 (Monitoring of the Recovery of Impacted Wetland and Open Bay Produced Water Discharge Sites in Coastal Louisiana and Texas) activities have included the narrowing of the list of potential offshore platforms for study off Louisiana and Texas and a preliminary selection of three coastal sites in Louisiana. After an extensive search effort, it was concluded that no coastal sites are available in Texas. A meeting was held between the contractor, Department of Energy (DOE), and Brookhaven National Laboratory (BNL) personnel to discuss potential sites and sampling designs. A letter was sent to the Scientific Review Committee (SRC) providing a general description of the revised site selection process and sampling designs. Task 5 (Assessment of Economic Impacts of Offshore and Coastal Discharge Requirements on Present and Future Operations in the Gulf of Mexico Region) activities included continued evaluation of data types available for the economic analysis. Historical field basis data were acquired. The identification of permitted discharge points was also initiated. Task 6 (Synthesis of Gulf of Mexico Seafood Consumption and Use Patterns) activities have involved the completion of the literature review. Drafts of the fisherman and wholesaler surveys were prepared. It was determined with DOE and BNL personnel that the retailer survey would be eliminated and a subsistence fisherman survey would be added. Task 7 (Technology Transfer Plan) work has been delayed due to the Tasks 3 and 4 delay and cancellation of the annual US Minerals Management Service (MMS) Gulf of Mexico Region Information Transfer Meeting. Task 8 (Project Management and Deliverables) activities have involved the submission of the necessary reports and routine management.

  9. Evaluation of medication safety in the discharge medication of 509 surgical inpatients using electronic prescription support software and an extended operational interaction classification.

    PubMed

    Frölich, Thomas; Zorina, Olesya; Fontana, Andrea O; Kullak-Ublick, Gerd A; Vollenweider, Andreas; Russmann, Stefan

    2011-12-01

    Our aim was to study drug interactions and dose adjustments in patients with renal impairment in the discharge medication of surgical inpatients and to evaluate the strengths and limitations of clinical decision support software (CDSS) for this task. This was a cross-sectional study involving 509 surgical patients of a primary care hospital. We developed a customized interface for the CDSS MediQ, which we used for automated retrospective identification of drug interactions in the patients' discharge medication. The clinical relevance of the interactions was evaluated based on the Zurich Interaction System (ZHIAS) that incorporates the operational classification of drug interactions (ORCA). Prescriptions were further analyzed for recommended dose adjustments in patients with a glomerular filtration rate <60 ml/min. For the total of 2,729 prescriptions written for the 509 patients enrolled in the study, MediQ generated 2,558 interaction alerts and 1,849 comments. Among these were ten "high danger" and 551 "average danger" alerts that we reclassified according to ORCA criteria. This reclassification resulted in ten contraindicated combinations, 77 provisionally contraindicated combinations, and 310 with a conditional and 164 with a minimal risk of adverse outcomes. The ZHIAS classification also provides categorical information on expected adverse outcomes and management recommendations, which are presented in detail. We identified 56 prescriptions without a recommended dose adjustment for impaired renal function. CDSS identified a large number of drug interactions in surgical discharge medication, but according to ZHIAS criteria only a minor fraction of these appeared to involve a substantial risk to the patient. CDSS should therefore aim at reducing over-alerting and improve usability in order to become more efficacious in terms of the prevention of adverse drug events in clinical practice.

  10. 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…

  11. 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…

  12. 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.

  13. Statistical prediction of seasonal discharge in Central Asia for water resources management: development of a generic (pre-)operational modeling tool

    NASA Astrophysics Data System (ADS)

    Apel, Heiko; Baimaganbetov, Azamat; Kalashnikova, Olga; Gavrilenko, Nadejda; Abdykerimova, Zharkinay; Agalhanova, Marina; Gerlitz, Lars; Unger-Shayesteh, Katy; Vorogushyn, Sergiy; Gafurov, Abror

    2017-04-01

    The semi-arid regions of Central Asia crucially depend on the water resources supplied by the mountainous areas of the Tien-Shan and Pamirs. During the summer months the snow and glacier melt dominated river discharge originating in the mountains provides the main water resource available for agricultural production, but also for storage in reservoirs for energy generation during the winter months. Thus a reliable seasonal forecast of the water resources is crucial for a sustainable management and planning of water resources. In fact, seasonal forecasts are mandatory tasks of all national hydro-meteorological services in the region. In order to support the operational seasonal forecast procedures of hydromet services, this study aims at the development of a generic tool for deriving statistical forecast models of seasonal river discharge. The generic model is kept as simple as possible in order to be driven by available hydrological and meteorological data, and be applicable for all catchments with their often limited data availability in the region. As snowmelt dominates summer runoff, the main meteorological predictors for the forecast models are monthly values of winter precipitation and temperature as recorded by climatological stations in the catchments. These data sets are accompanied by snow cover predictors derived from the operational ModSnow tool, which provides cloud free snow cover data for the selected catchments based on MODIS satellite images. In addition to the meteorological data antecedent streamflow is used as a predictor variable. This basic predictor set was further extended by multi-monthly means of the individual predictors, as well as composites of the predictors. Forecast models are derived based on these predictors as linear combinations of up to 3 or 4 predictors. A user selectable number of best models according to pre-defined performance criteria is extracted automatically by the developed model fitting algorithm, which includes a test

  14. Environmental and economic assessment of discharges from Gulf of Mexico Region Oil and Gas Operations. Quarterly technical progress report, 1 October--31 December 1993

    SciTech Connect

    Gettleson, D.A.

    1994-01-28

    Task 2 (Preparation of the Sampling and Analysis Plan) activities involved the incorporation of the offshore site selection process into the Sampling and Analysis Plan. Task 3 (Environmental Field Sampling and Analysis of NORM, Heavy Metals, and Organics) work included making decisions on tissue analyses and performing analyses of water and sediment samples. Task 4 (Monitoring of the Recovery of Impacted Wetland and Open Bay Produced Water Discharge Sites in Coastal Louisiana and Texas) activities involved the completion of the spring benthos samples collection on pre-termination samples at Four Isle Dome and the first post-termination samples at Delacroix Island. Task 5 (Assessment of Economic Impacts of Offshore and Coastal Discharge Requirements on Present and Future Operations in the Gum of Mexico Region) activities included continued work on development of a base case production forecast, modeling future production, and determining economic impact of treatment technologies. Task 6 (Synthesis of Gulf of Mexico Seafood Consumption and Use Patterns) work involved the completion of the fall survey season and the initiation of the survey data assembly. Task 7 (Technology Transfer Plan) activities included presentations at the Society of Environmental Toxicology and Chemistry annual meeting and Minerals Management Service Information Transfer Meeting. Task 8 (Project Management and Deliverables) activities involved the submission of the necessary reports and routine management.

  15. Environmental and economic assessment of discharges from Gulf of Mexico region oil and gas operations. Quarterly technical progress report, 1 January--31 March 1993

    SciTech Connect

    Gettleson, D.A.

    1993-04-22

    Task 3 (Environmental Field Sampling and Analysis of NORM, Heavy Metals, and Organics) activities included the continuation of the platform selection process. A revised sampling plan and a projected cost estimate were prepared for Task 3. A letter detailing the revised plan was sent to the Scientific Review Committee (SRC). Task 4 (Monitoring of the Recovery of Impacted Wetland and Open Bay Produced Water Discharge Sites in Coastal Louisiana and Texas) activities involved receiving the final approval for sampling two facilities and requesting approval for a third alternative facility. A revised Task 4 sampling plan and projected estimated costs were prepared. The sampling plan was presented to the SRC for comment. Mobilization activities for the first quarterly sampling were initiated. Task 5 (Assessment of Economic Impactsof Offshore and Coastal Discharge Requirements on Present and Future Operations in the Gulf of Mexico Region) activities included refining the model for estimating the impact of increased environmental compliance costs on remaining reserves in coastal and offshore fields. Task 6 (Synthesis of Gulf of Mexico Seafood Consumption and Use Patterns) activities involved completion and field testing of most survey forms. Retail surveys were initiated and contacts were made with the Vietnamese community. Task 7 (Technology Transfer Plan) work has included scheduling the presentation of information concerning this project at the DOE Contractor Review Meeting in July in Oklahoma. Task 8 (Project Management and Deliverables) activities have involved the submission of the necessary reports and routine management.

  16. Environmental and economic assessment of discharges from Gulf of Mexico Region oil and gas operations. Quarterly technical progress report, 23 June 1992--30 September 1992

    SciTech Connect

    Gettleson, D.A.

    1992-11-10

    A Sampling and Analysis Plan was prepared and submitted to a Scientific Review Committee for comment. Substantial comments relative to study objectives, sampling design, and sampling periods coupled with the passage of Hurricane Andrew precluded the scheduled initiation of sampling at offshore and coastal sites (Tasks 3 -- Environmental Field Sampling and Analysis of Naturally Occurring Radioactive Materials (NORM), Heavy Metals, and Organics and 4 -- Monitoring of the Recovery of Impacted Wetland and Open Bay Produced Water Discharge Sites in Coastal Louisiana and Texas). A proposed revised schedule has been prepared for Tasks 3 and 4. Task 5 (Assessment of Economic Impacts of Offshore and Coastal Discharge Requirements on Present and Future Operations in the Gulf of Mexico Region), activities have involved identification and collection of the necessary data for the economic analysis. Task 6 (Synthesis of Gulf of Mexico Region Consumption and Use Patterns), activities have included near completion of the literature review and a reevaluation of the data collection efforts relative to the wholesaler, process plant, and restaurant components. Task 7 (Technology Transfer Plan), work has been delayed due to the Tasks 3 and 4 delay and cancellation of the annual US Minerals Management Service Gulf of Mexico Region Information Transfer Meeting.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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 - ...

  2. Pediatric heart surgery - discharge

    MedlinePlus

    Congenital heart surgery - discharge; Patent ductus arteriosus ligation - discharge; Hypoplastic left heart repair - discharge; Tetralogy of Fallot repair - discharge; Coarctation of the aorta repair - discharge; ...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. Anomalous Transport in Closed and Open-Drift Hall Discharges

    NASA Astrophysics Data System (ADS)

    Cappelli, Mark; Meezan, Nathan; Schmidt, Dan

    1999-10-01

    Hall discharges are presently under development for use in space propulsion applications. These discharges exhibit characteristic cross-field transport, which is enhanced by fluctuations in the electric field and plasma density. Our recent electrostatic probe and laser-induced fluorescence measurements in closed-drift coaxial geometry discharges indicate that the effective Hall parameter ranges from 1 - 20. This value is much less than that based on classical electron transport, and while it brackets the value typical of anomalous Bohm transport, it is found to vary significantly along the axial direction of the discharge, increasing to unusually low values near the anode. This high anomalous transport explains in part why we have been able to successfully operate Hall discharges of a linear geometry (with an open Hall current). In this paper, we shall also present recent measurements of time-resolved emission along the anode from which fluctuations in electron density and average electron energy are characterized. The emission measurements are found to be in qualitative agreement with time-averaged measurements of the Hall parameter, indicating that in some operating regimes, there are intense fluctuations in the near-anode plasma regions.

  10. Anomalous Transport in Closed-Drift Hall Discharges

    NASA Astrophysics Data System (ADS)

    Meezan, N. B.; Cappelli, M. A.

    1999-11-01

    Hall discharges are presently under development for use in space propulsion applications. These discharges exhibit characteristic cross-field transport, which is believed to be enhanced by fluctuations in the electric field and plasma density. Recent electrostatic probe and laser-induced fluorescence measurements in closed-drift coaxial geometry discharges indicate that the effective Hall parameter ranges from 1-20. This value is much less than that based on classical electron transport, and while it brackets the value typical of anomalous Bohm transport, it is found to vary significantly along the axial direction of the discharge, increasing to unusually low values near the anode. This high anomalous transport explains in part why we have been able to successfully operate Hall discharges of a linear geometry (with an open Hall current). In this paper, we shall also present recent measurements of time-resolved emission along the anode from which fluctuations in electron density and average electron energy are characterized. The emission measurements are found to be in qualitative agreement with time-averaged measurements of the Hall parameter, indicating that in some operating regimes, there are intense fluctuations in the near-anode plasma regions.

  11. Mode operation of inductively-coupled argon plasmas studied by optical emission spectroscopy

    NASA Astrophysics Data System (ADS)

    Iordanova, S.; Koleva, I.

    2007-04-01

    Mode operation of inductively driven plasmas in argon gas at low pressures is studied by optical emission spectroscopy. The plasma source is a tandem type source with a driver and an expansion plasma region. The driver region of the discharge is in the classical form of a cylindrically shaped inductive discharge, with a coil positioned over a gas discharge tube. The inductively coupled plasma discharge is maintained at high frequency f = 27 MHz, applied power varied in the limits P = (20-700) W and gas pressure in the range p = (8-260) mTorr. The Ar line intensity dependencies on the applied power injected into the discharge is analysed. With the power increase a mode transition of the discharge regime is not observed. The investigations on the discharge mode operation are supported by theoretical calculations based on kinetic modelling of main processes contributing to the line intensity behaviour.

  12. A model for precessing helical vortex in the turbine discharge cone

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    The decelerated swirling flow in the discharge cone of hydraulic turbine develops various self-induced instabilities and associated low frequency phenomena when the turbine is operated far from the best efficiency regime. In particular, the precessing helical vortex ("vortex rope") developed at part-load regimes is notoriously difficult and expensive to be computed using full three-dimensional turbulent unsteady flow models. On the other hand, modern design and optimization techniques require robust, tractable and accurate a-priori assessment of the turbine flow unsteadiness level within a wide operating range before actually knowing the runner geometry details. This paper presents the development and validation of a quasi-analytical model of the vortex rope in the discharge cone. The first stage is the computing of the axisymmetrical swirling flow at runner outlet with input information related only to the operating point and to the blade outlet angle. Then, the swirling flow profile further downstream is computed in successive cross-sections through the discharge cone. The second stage is the reconstruction of the precessing vortex core parameters in successive cross-sections of the discharge cone. The final stage lies in assembling 3D unsteady flow field in the discharge cone. The end result is validated against both experimental and numerical data.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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 ...

  19. Gallstones - discharge

    MedlinePlus

    ... full liquid Pancreatitis - discharge Wet-to-dry dressing changes Review Date 12/2/2016 Updated by: Michael M. Phillips, MD, Clinical Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by ...

  20. 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 ...

  1. 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 ...

  2. 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.

  3. 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.

  4. 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 ...

  5. 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 ...

  6. 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

  7. 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

  8. Plate-like Dusty Structures in an e-Beam Sustained Glow Discharge at Atmospheric Pressure

    NASA Astrophysics Data System (ADS)

    Filippov, Anatoly V.; Babichev, Valery N.; Pal', Alexander F.; Starostin, Andrey N.

    2005-10-01

    The paper is devoted to studying the dusty plasma created by the injection of dust particles into the atmospheric pressure gas ionized by an electron beam of 85-120 keV energy. The beam current density was varied within 0.1-1.0 mA/cm2. The electron gun operated in the stationary regime. The behavior of dusty particles lighted by a laser ``knife'' was observed with a digital video camera. Stable plate-like structures were observed in the cathode sheath of non-self-sustained discharge. Numerical simulation was performed by using the non-local model of the non-self-sustained discharge.

  9. Time to replace adjusted discharges.

    PubMed

    Cleverley, William O

    2014-05-01

    With inpatient revenue averaging less than 50 percent of total operating revenue for hospitals and bundled payments becoming the norm, Equivalent Discharges is a simple, alternative metric that offers superior predictive power of hospital volume. Equivalent Discharges are not subject to the same measurement flaws as adjusted discharges or adjusted patient days. The new metric also explains cost variation in situations where there is a more complex case mix.

  10. 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

  11. Improving Value in Total Joint Arthroplasty: A Comprehensive Patient Education and Management Program Decreases Discharge to Post-Acute Care Facilities and Post-Operative Complications.

    PubMed

    Pelt, Christopher E; Gililland, Jeremy M; Erickson, Jill A; Trimble, Dory E; Anderson, Mike B; Peters, Christopher L

    2017-08-19

    A step-by-step approach to creating a comprehensive patient education, expectation, and management program is described with the aim of reducing discharges to post-acute care centers (PACs) following total joint arthroplasty (TJA). We hypothesized that by lowering discharges to PACs, readmissions and reoperations would also decrease. Following the implementation of a multi-faceted patient education and management program, we retrospectively reviewed 927 TJAs who underwent surgery 12 months before (n = 465) and after (n = 462) the program was implemented. To assess the exposure of the pathway on discharge disposition as well as institutional 30-day and 90-day readmissions and reoperations, a modified Poisson regression was used. There was a 20% absolute reduction in discharges to PACs (<0.001). The frequency of 30-day readmissions was greater in patients who underwent TJA before implementation (incidence rate ratio [IRR] 1.93, 95% confidence interval [CI] 1.01-3.69). The risk for 90-day readmissions (IRR 1.70, 95% CI 1.20-2.40) and reoperations (IRR 1.67, 95% CI 1.12-2.53) was greater prior to implementation. Discharge to PACs was associated with 2.4 and 3.10 times greater risk for 30-day readmissions (95% CI 1.28-4.56) and 30-day reoperations (95% CI 1.40-7.0), respectively. Patients discharged to PACs were also at greater risk for both 90-day readmissions (IRR 1.59, 95% CI 1.08-2.32) and 90-day reoperations (IRR 1.75, 95% CI 1.12-2.73). Our program led to a reduction in the number of patients being discharged to PACs following TJA, while also demonstrating a reduction in readmission and reoperations. Additionally, discharge to these facilities was an independent risk factor for these complications. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Exploitation rates of two benthic resources across management regimes in central Chile: Evidence of illegal fishing in artisanal fisheries operating in open access areas

    PubMed Central

    Andreu-Cazenave, Miguel; Subida, Maria Dulce; Fernandez, Miriam

    2017-01-01

    There is an urgent need to quantify the impacts of artisanal fisheries and define management practices that allow for the recovery and conservation of exploited stocks. The extent of illegal catch is particularly critical as a driver of overexploitation in artisanal fisheries. However, the lack of data at proper spatial scales limits the evaluation of illegal fishing and effectiveness of management practices. We used a catch curve analysis to estimate total instantaneous mortality as a proxy of fishing pressure in the artisanal benthic fishery in central Chile. We compared the patterns of total mortality in fishing grounds under the well-studied territorial use rights for fisheries system (TURF) immersed in a landscape of open access areas (OAA; no access restriction), and from these patterns determined the extent of illegal fishing in open access areas focusing on the two most frequently extracted resources: locos (Concholepas concholepas) and keyhole limpets (Fissurella spp.). The beauty of this seascape is the presence of the no-take (NT) area of Las Cruces as control (no fishing), allowing us to estimate natural mortality. Loco exploitation is banned in OAAs. However, loco mortality in OAAs was 92% higher than in the NT, and 42% higher than in TURFs. Keyhole limpet mortality was similar between TURFs and the NT, but doubled in OAAs. We also found strong differences in mortality among fishing grounds with the same level of protection (i.e. TURFs), and over time. Our results highlight (a) the high level of illegal fishing that may occur in artisanal fisheries under traditional management regimes, and (b) that TURFs can be effective to reduce fishing mortality. However, large variability among TURFs suggests the need for a deeper understanding of the drivers of success of TURFs. PMID:28666013

  13. Exploitation rates of two benthic resources across management regimes in central Chile: Evidence of illegal fishing in artisanal fisheries operating in open access areas.

    PubMed

    Andreu-Cazenave, Miguel; Subida, Maria Dulce; Fernandez, Miriam

    2017-01-01

    There is an urgent need to quantify the impacts of artisanal fisheries and define management practices that allow for the recovery and conservation of exploited stocks. The extent of illegal catch is particularly critical as a driver of overexploitation in artisanal fisheries. However, the lack of data at proper spatial scales limits the evaluation of illegal fishing and effectiveness of management practices. We used a catch curve analysis to estimate total instantaneous mortality as a proxy of fishing pressure in the artisanal benthic fishery in central Chile. We compared the patterns of total mortality in fishing grounds under the well-studied territorial use rights for fisheries system (TURF) immersed in a landscape of open access areas (OAA; no access restriction), and from these patterns determined the extent of illegal fishing in open access areas focusing on the two most frequently extracted resources: locos (Concholepas concholepas) and keyhole limpets (Fissurella spp.). The beauty of this seascape is the presence of the no-take (NT) area of Las Cruces as control (no fishing), allowing us to estimate natural mortality. Loco exploitation is banned in OAAs. However, loco mortality in OAAs was 92% higher than in the NT, and 42% higher than in TURFs. Keyhole limpet mortality was similar between TURFs and the NT, but doubled in OAAs. We also found strong differences in mortality among fishing grounds with the same level of protection (i.e. TURFs), and over time. Our results highlight (a) the high level of illegal fishing that may occur in artisanal fisheries under traditional management regimes, and (b) that TURFs can be effective to reduce fishing mortality. However, large variability among TURFs suggests the need for a deeper understanding of the drivers of success of TURFs.

  14. A survey of prosthetic eye wearers to investigate mucoid discharge

    PubMed Central

    Pine, Keith; Sloan, Brian; Stewart, Joanna; Jacobs, Robert J

    2012-01-01

    Background This study aimed to better understand the causes and treatments of mucoid discharge associated with prosthetic eye wear by reviewing the literature and surveying anophthalmic patients. Methods An anonymous questionnaire was completed by 429 prosthetic eye wearers who used visual analog scales to self-measure their discharge experience for four discharge characteristics: frequency, color, volume, and viscosity. These characteristics were analyzed with age, ethnicity, years wearing a prosthesis, eye loss cause, removal and cleaning regimes, hand-washing behavior, age of current prosthesis, and professional repolishing regimes as explanatory variables. Eighteen ocularists’ Web sites containing comments on the cause and treatment of discharge were surveyed. Results Associations were found between discharge frequency and cleaning regimes with more frequent cleaning accompanying more frequent discharge. Color was associated with years of wearing and age, with more years of wearing and older people having less colored discharge. Volume was associated with cleaning regimes with more frequent cleaners having more volume. Viscosity was associated with cleaning regimes and years of wearing with more frequent cleaning and shorter wearing time accompanying more viscous discharge. No associations were found between discharge characteristics and ethnicity, eye loss cause, hand washing, age of current prosthesis, or repolishing regimes. Forty-seven percent of ocularists’ Web sites advised that discharge was caused by surface deposits on the prosthesis, 29% by excessive handling of the prosthesis, and 24% by other causes. Conclusions A standardized treatment protocol for managing discharge is lacking. More frequent prosthesis removal and cleaning was associated with more severe discharge, but the direction of cause and effect has not been established. Professional repolishing regimes had limited impact on discharge experience. Further research into the socket

  15. New Combustion Regimes and Kinetic Studies of Plasma Assisted Combustion

    DTIC Science & Technology

    2012-11-01

    New combustion regimes and kinetic studies of plasma assisted combustion Nov.6-7, 2012 MURI Plasma 3rd Yr Review Meeting MURI Topic #11: Chemical...TITLE AND SUBTITLE New combustion regimes and kinetic studies of plasma assisted combustion 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...Flow reactor Species and kinetics (Ju) 1. New combustion regimes and kinetic studies of in situ plasma discharge in counterflow flames

  16. 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 ...

  17. Two-dimensional simulation of a direct-current microhollow cathode discharge

    NASA Astrophysics Data System (ADS)

    Kothnur, Prashanth S.; Raja, Laxminarayan L.

    2005-02-01

    Microhollow cathode discharges (MHCD's) are miniature direct-current discharges that operate at elevated pressures (several tens to hundreds of Torr) with electrode dimensions in the 10-100-μm range. MHCD's have been proposed for a number of applications based on their unique characteristics such as presence of intense excimer radiation and significant gas heating within the submillimeter discharge volume. A two-dimensional, self-consistent fluid model of a helium MHCD in the high-pressure (several hundreds of Torr), high-current (˜1mA) operating regime is presented in this study. Results indicate that the MHCD operates in an abnormal glow discharge mode with charged and excited metastable species with densities of ˜1020m-3, electron temperatures of approximately tens of eV, and gas temperatures of hundreds of Kelvin above room temperature. Significant discharge activity exists outside of the hollow region. The discharge volume and intensity increases with increasing current and becomes more confined with increasing pressures. Most predictions presented in this paper are in qualitative and quantitative agreement with experimental data for MHCD's under similar conditions.

  18. BABE - a brush cathode discharge for thermal fluctuation measurements

    NASA Astrophysics Data System (ADS)

    Ratynskaia, S.; Dilecce, G.; Tolias, P.

    2015-04-01

    For experimental tests of fluctuation theory in ideal plasmas and plasmas seeded with dust, the ideal environment would be that of stable quiescent plasma. In most laboratory plasmas the homogeneous state of the positive column is often unstable, rare exceptions are the so-called brush cathode discharges, proposed in the 60s, where a specially manufactured cathode allows stable operation in the abnormal glow regime and the only fluctuations present are those due the thermal motion of the particles. Such a device, the BAri Brush Electrode (BABE), has recently been built in a novel configuration that combines the advantages of the inverse design with those of the reflex geometry. The region between the two anodes is essentially field-free and extremely stable in wide range of plasma densities and collisionalities. Unprecedented low fluctuation levels of δn/n <= 10-5 in He and δn/n <= 5 × 10-6 in Ar discharges have been achieved.

  19. Membranes minimize liquid discharge

    SciTech Connect

    Cappos, S.

    1995-07-01

    Zero discharge is a matter of concentration. Liquid and solid waste are repeatedly reduced to minimize or eliminate their discharge. But the process is intense, requiring an array of filtering and purifying technologies to achieve discharge goals. One of the most productive and effective technologies for this purpose is reverse osmosis (RO). Developed in the 1960s, RO produces a high-quality permeate for reuse, and a small concentrated stream for further treatment. The addition of RO to a wastewater treatment system can reduce overall operating costs and the capital costs of other components, as well as reduce a waste treatment system`s reliance on chemical treatment. The paper discusses how RO works, when RO is the best solution, where the waste goes, alternative technologies (clarifiers, vapor compression evaporators, and ion exchange demineralizers), and recent advances in membrane technology.

  20. 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.

  1. 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

  2. How can a change in the operating system of the mental health review board promote the discharge of long-term hospitalized psychiatric patients? A case study of Seoul city.

    PubMed

    Lee, Myung-Soo; Lim, Hee-Young; Kim, Youngki; Lee, Yong-Suk

    2014-01-01

    One of the most typical and chronic problem in Korean mental health system is the prolonged length of hospital stay. In contrast to there are many components which leads to long length of stay of psychiatric patients in Korean situation such as low and fixed medical fee for psychiatric inpatient treatment, shortage of community resources, lack of care-givers' awareness and so on, there are just few mechanisms to handle this issue such as Mental Health Review Board (MHRB) which is based on Mental Health Act since 1995. However, the discharge order rate was very low and there community care system after discharge order is still very weak. The Korean government has revised the Mental Health Act in 2008 and changed the operating principals of the MHRB from a regional level to a local level to strengthen the function of MHRB. However, the discharge order rate versus the whole evaluation requests still remains at a very low level or less than 5%. And it is still very difficult to execute a discharge order against a patient whose symptoms and conditions become psychiatrically stabilized enough for discharge, due to a shortage of community care facilities and a lack of social support system. These results are exactly same with former studies. Any policies to promote psychiatric discharge including MHRB are needed to take the comprehensive factors into consideration, such as payment program, community infrastructure, increasing care-givers' acceptance and so on. Despite of the political trial of Korean government to reduce length of stay of chronic psychiatric patients, it was not successful. Still it had failed to propose a detailed policy measure in terms of the above-mentioned prerequisites. Therefore, new system and program developments including reform of payment system which reflect prior studies' recommendations are essential.

  3. 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).

  4. 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...

  5. 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...

  6. Environmental and economic assessment of discharges from Gulf of Mexico Region Oil and Gas Operations. Quarterly technical progress report, January 1, 1994--March 31, 1994

    SciTech Connect

    Gettleson, D.A.

    1994-04-21

    The primary objectives of the project are to increase the base of scientific knowledge concerning (1) the fate and environmental effects of organics, trace metals, and NORM in water, sediment, and biota near several offshore oil and gas facilities; (2) the characteristics of produced water and produced sand discharges as they pertain to organics, trace metals, and NORM variably found in association with the discharges; (3) the recovery of four terminated produced water discharge sites located in wetland and high-energy open bay sites of coastal Louisiana and Texas; (4) the economic and energy supply impacts of existing and anticipated federal and state offshore and coastal discharge regulations; and (5) the catch, consumption and human use patterns of seafood species collected from coastal and offshore waters. The products of the effort will be a series of technical reports detailing the study procedures, results, and conclusions which contribute to the transfer of technology to the scientific community, petroleum industry, and state and federal programs.

  7. 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.

  8. Hysterectomy - vaginal - discharge

    MedlinePlus

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

  9. 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 ...

  10. Effects of periodic discharges

    NASA Technical Reports Server (NTRS)

    Ford, F. E.

    1977-01-01

    Periodic capacity checks are assessed as well as the effects of periodic discharges on the cycle life and the performance of cells during the cycle life. Topics discussed include the effect of the amount of electrolyte on cell capacity at 35 C; battery design for spacecraft; electrolyte starvation theory; battery separator degradation; negative electrode stability; voltage regulation; operating temperatures; and integration of reconditioning systems using microprocessors.

  11. 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,…

  12. 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.

  13. 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.

  14. 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, ...

  15. 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 ...

  16. Brain injury - discharge

    MedlinePlus

    Head injury - discharge; Head trauma - discharge; Contusion - discharge; Shaken baby syndrome - discharge ... done to help them recover from the brain injury. The person may have stayed in a special ...

  17. Lung surgery - discharge

    MedlinePlus

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

  18. 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.

  19. 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

  20. 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.

  1. Performance of a large-scale barrier discharge plume improved by an upstream auxiliary barrier discharge

    NASA Astrophysics Data System (ADS)

    Li, Xuechen; Chu, Jingdi; Zhang, Qi; Zhang, Panpan; Jia, Pengying; Geng, Jinling

    2016-11-01

    Enhanced by an upstream auxiliary dielectric barrier discharge (ADBD), a transverse barrier discharge plume with a fairly large scale is generated downstream of a narrow slit. Electrical and optical characteristics are compared for the two discharges with and without the ADBD. Results indicate that the plume with the ADBD is longer, more uniform, and dissipates a higher power. Moreover, its inception voltage is much lower. High-speed imaging presents that the uniform plasma plume with the ADBD comprises a series of moving micro-discharge filaments in a glow regime, which are much smoother than those without the ADBD.

  2. 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.

  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. 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.

  5. 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.

  6. 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.

  7. A Regime Diagram for Subduction

    NASA Astrophysics Data System (ADS)

    Stegman, D. R.; Farrington, R.; Capitanio, F. A.; Schellart, W. P.

    2009-12-01

    regimes are generated primarily as a product of two mechanisms. The first mechanism is that of the competition between the weight of the slab and the strength of the plate, which can be understood in terms of the applied bending moment, and this competition results in a particular radius of curvature (for which we provide a simple scaling theory). The second mechanism is the interaction between the slab and the more viscous lower mantle, which produces each regime's distinct slab morphology. Thus, the emergence of five distinct styles of subduction is a direct consequence of the presence of the modest barrier to flow into the lower mantle. Although only 2 of these styles presently operate on Earth, the possibility exists that other modes may have been the predominant mode in the past. Based on these models, we propose that the lithosphere is the primary factor in describing key elements of the plate tectonics system over time, rather than the convecting mantle. We discuss the various factors that may have influenced secular changes in Earth's tectonic behavior, some of which may have interesting consequences for the geochemical evolution of the Earth.

  8. 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.

  9. 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.

  10. Simulation of pulsed dielectric barrier discharge xenon excimer lamp

    NASA Astrophysics Data System (ADS)

    Bogdanov, E. A.; Kudryavtsev, A. A.; Arslanbekov, R. R.; Kolobov, V. I.

    2004-11-01

    Recently, it has been shown that the efficiency of excimer lamps can be drastically increased in a pulsed regime. A one-dimensional simulation of pulsed excimer lamps has been performed by Carman and Mildren (2003 J. Phys. D: Appl. Phys. 36 19) (C&M). However, some computational results of the work of C&M are questionable and need to be revisited. In this paper, a dielectric barrier discharge (DBD) in xenon has been simulated for operating conditions similar to those of C&M to better understand plasma dynamics in a pulsed regime. Our simulation results differ considerably from the computational results of C&M. Although these differences do not affect profoundly the plasma macro parameters measured in the C&M experiments, they offer a better understanding of plasma dynamics in pulsed DBDs and form a solid foundation for computational optimization of excimer lamps. It was found that the dynamics of breakdown and the current pulse depend significantly on the initial densities of species after a previous pulse, and so it is important to accurately simulate the plasma evolution in both the afterglow and active stages. It seems possible to modify the power deposition in the plasma by varying external discharge parameters such as the amplitude and the rise time of the applied voltage, and to modify the plasma composition by changing the pulse repetition rate and plasma decay in the afterglow stage.

  11. 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.

  12. 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.

  13. Water treatment plant sludge discharge to wastewater treatment works: effects on the operation of upflow anaerobic sludge blanket reactor and activated sludge systems.

    PubMed

    Asada, Lucia N; Sundefeld, Gilberto C; Alvarez, Carlos R; Filho, Sidney Seckler Ferreira; Piveli, Roque P

    2010-05-01

    This experiment examined the effects of the discharge of water treatment plant (WTP) sludge into the following three types of wastewater treatment systems: a pilot-scale upflow anaerobic sludge blanket (UASB) reactor, a pilot-scale activated sludge system, and a full-scale activated sludge sequencing batch reactor (SBR). The UASB reactor received 50 mg of suspended solids (SS) of WTP sludge per liter of wastewater in the first phase, and, in the second phase, it received 75 mg SS/L. The pilot-scale activated sludge system received 25 and 50 mg SS/L in the first and second phases, respectively. The full-scale WWTP (SBR) received approximately 74 mg SS/L. The results of the experiments showed that, despite some negative effects on nitrification, there were positive effects on phosphorus removal, and, furthermore, there was the addition of solids in all systems.

  14. 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. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. 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.

  16. 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

  17. 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. © 2015 The Authors.

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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.

  4. 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.

  5. 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

  6. 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 ...

  7. 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 ...

  8. 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 ...

  9. 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.

  10. The Vapor-phase Multi-stage CMD Test for Characterizing Contaminant Mass Discharge Associated with VOC Sources in the Vadose Zone: Application to Three Sites in Different Lifecycle Stages of SVE Operations

    PubMed Central

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

    2015-01-01

    Vapor-phase multi-stage contaminant mass discharge (CMD) tests were conducted at three field sites to measure mass discharge associated with contaminant sources located in the vadose zone. The three sites represent the three primary stages along the soil vapor extraction (SVE) operations lifecycle- pre/initial-SVE, mid-lifecycle, and near-closure. A CMD of 32 g/d was obtained for a site at which soil vapor SVE has been in operation for approximately 6 years, and for which mass removal is currently in the asymptotic stage. The contaminant removal behavior exhibited for the vapor extractions conducted at this site suggests that there is unlikely to be a significant mass of non-vapor-phase contaminant (e.g., DNAPL, sorbed phase) remaining in the advective domains, and that most remaining mass is likely located in poorly accessible domains. Given the conditions for this site, this remaining mass is hypothesized to be associated with the low-permeability (and higher water saturation) region in the vicinity of the saturated zone and capillary fringe. A CMD of 25 g/d was obtained for a site wherein SVE has been in operation for several years but concentrations and mass-removal rates are still relatively high. A CMD of 270 g/d was obtained for a site for which there were no prior SVE operations. The behavior exhibited for the vapor extractions conducted at this site suggest that non-vapor-phase contaminant mass (e.g., DNAPL) may be present in the advective domains. Hence, the asymptotic conditions observed for this site most likely derive from a combination of rate-limited mass transfer from DNAPL (and sorbed) phases present in the advective domain as well as mass residing in lower-permeability (“non-advective”) regions. The CMD values obtained from the tests were used in conjunction with a recently developed vapor-discharge tool to evaluate the impact of the measured CMDs on groundwater quality. PMID:26047819

  11. 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 ...

  12. Regimes of Helium Burning

    NASA Astrophysics Data System (ADS)

    Timmes, F. X.; Niemeyer, J. C.

    2000-07-01

    The burning regimes encountered by laminar deflagrations and Zeldovich von Neumann Döring (ZND) detonations propagating through helium-rich compositions in the presence of buoyancy-driven turbulence are analyzed. Particular attention is given to models of X-ray bursts that start with a thermonuclear runaway on the surface of a neutron star and to the thin-shell helium instability of intermediate-mass stars. In the X-ray burst case, turbulent deflagrations propagating in the lateral or radial direction encounter a transition from the distributed regime to the flamelet regime at a density of ~108 g cm-3. In the radial direction, the purely laminar deflagration width is larger than the pressure scale height for densities smaller than ~106 g cm-3. Self-sustained laminar deflagrations traveling in the radial direction cannot exist below this density. Similarly, the planar ZND detonation width becomes larger than the pressure scale height at ~107 g cm-3, suggesting that steady state, self-sustained detonations cannot come into existence in the radial direction. In the thin helium shell case, turbulent deflagrations traveling in the lateral or radial direction encounter the distributed regime at densities below ~107 g cm-3 and the flamelet regime at larger densities. In the radial direction, the purely laminar deflagration width is larger than the pressure scale height for densities smaller than ~104 g cm-3, indicating that steady state laminar deflagrations cannot form below this density. The planar ZND detonation width becomes larger than the pressure scale height at ~5×104 g cm-3, suggesting that steady state, self-sustained detonations cannot come into existence in the radial direction.

  13. Regimes of Helium Burning

    SciTech Connect

    Timmes, F. X.; Niemeyer, J. C.

    2000-07-10

    The burning regimes encountered by laminar deflagrations and Zeldovich von Neumann Doering [ZND] detonations propagating through helium-rich compositions in the presence of buoyancy-driven turbulence are analyzed. Particular attention is given to models of X-ray bursts that start with a thermonuclear runaway on the surface of a neutron star and to the thin-shell helium instability of intermediate-mass stars. In the X-ray burst case, turbulent deflagrations propagating in the lateral or radial direction encounter a transition from the distributed regime to the flamelet regime at a density of {approx}108 g cm-3. In the radial direction, the purely laminar deflagration width is larger than the pressure scale height for densities smaller than {approx}106 g cm-3. Self-sustained laminar deflagrations traveling in the radial direction cannot exist below this density. Similarly, the planar ZND detonation width becomes larger than the pressure scale height at {approx}107 g cm-3, suggesting that steady state, self-sustained detonations cannot come into existence in the radial direction. In the thin helium shell case, turbulent deflagrations traveling in the lateral or radial direction encounter the distributed regime at densities below {approx}107 g cm-3 and the flamelet regime at larger densities. In the radial direction, the purely laminar deflagration width is larger than the pressure scale height for densities smaller than {approx}104 g cm-3, indicating that steady state laminar deflagrations cannot form below this density. The planar ZND detonation width becomes larger than the pressure scale height at {approx}5x10{sup 4} g cm-3, suggesting that steady state, self-sustained detonations cannot come into existence in the radial direction. (c) 2000 The American Astronomical Society.

  14. Aeration efficiency over stepped cascades: better predictions from flow regimes.

    PubMed

    Khdhiri, Hatem; Potier, Olivier; Leclerc, Jean-Pierre

    2014-05-15

    Stepped cascades are recognized as high potential air-water gas exchangers. In natural rivers, these structures enhance oxygen transfer to water by creating turbulence at interface with increasing air entrainment in water and air-water surface exchange. Stepped cascades could be really useful to improve the natural self-purification process by providing oxygen to aerobic micro-organisms. The aeration performance of these structures depends on several operating and geometrical parameters. In the literature, several empirical correlations for aeration efficiency prediction on stepped cascades exist. Most of these correlations are only applicable for operating and geometrical parameters in the range of which they have been developed. In this paper, 398 experimental sets of data (from our experiments and collected from literature) were used to develop a correlation for aeration prediction over stepped cascades derived from dimensional analysis and parameterized for each individual flow regime in order to consider change in flow regime effect on oxygen transfer. This new correlation allowed calculating the whole set of data obtained for cascades with steps heights between 0.05 m and 0.254 m, cascade total height between 0.25 m and 2.5 m, for discharges per unit of width ranging from 0.28 10(-3) m(2)/s to 600 10(-3) m(2)/s and for cascade steps number between 3 and 25. In these ranges of parameters, standard deviation for aeration efficiency estimation was found to be less than 17%. Finally, advices were proposed to help and improve the structure design in order to improve aeration. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2017-06-01

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

  16. Cross-scale analysis of fire regimes

    Treesearch

    Donald A. Falk; Carol Miller; Donald McKenzie; Anne E. Black

    2007-01-01

    Cross-scale spatial and temporal perspectives are important for studying contagious landscape disturbances such as fire, which are controlled by myriad processes operating at different scales. We examine fire regimes in forests of western North America, focusing on how observed patterns of fire frequency change across spatial scales. To quantify changes in fire...

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Human and organizational errors in loading and discharge operations at marine terminals: Reduction of tanker oil and chemical spills. Organizing to minimize human and organizational errors

    SciTech Connect

    Mannarelli, T.; Roberts, K.; Bea, R.

    1995-11-01

    This report summarizes organizational and managerial findings, and proposes corresponding recommendations, based on a program of research conducted at two major locations: Chevron USA Products Company Refinery in Richmond, California and Arco Marine Incorporated shipping operations in Long Beach, California. The Organizational Behavior and Industrial Relations group from the Business School approached the project with the same objective (of reducing the risk of accidents resulting from human and/or organizational errors), but used a different means of achieving those ends. On the Business side, the aim of the project is to identify organizational and managerial practices, problems, and potential problems, analyze them, and then make recommendations that offer potential solutions to those circumstances which pose a human and/or organizational error (HOE) risk.

  2. 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.

  3. 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.

  4. 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.

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

    PubMed

    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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Setup Aid for Electrical-Discharge Machining

    NASA Technical Reports Server (NTRS)

    Lines, G.; Duca, J.

    1985-01-01

    Interlock assures that workpiece is correctly assembled in machining fixture. A Plunger in a Hollow Shaft actuates a switch, allowing a power supply to produce current for electrical-discharge machining. Plunger operates only when necessary parts are position.

  13. 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.

  14. 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.

  15. 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.

  16. Discharge reliability in ablative pulsed plasma thrusters

    NASA Astrophysics Data System (ADS)

    Wu, Zhiwen; Sun, Guorui; Yuan, Shiyue; Huang, Tiankun; Liu, Xiangyang; Xie, Kan; Wang, Ningfei

    2017-08-01

    Discharge reliability is typically neglected in low-ignition-cycle ablative pulsed plasma thrusters (APPTs). In this study, the discharge reliability of an APPT is assessed analytically and experimentally. The goals of this study are to better understand the ignition characteristics and to assess the accuracy of the analytical method. For each of six sets of operating conditions, 500 tests of a parallel-plate APPT with a coaxial semiconductor spark plug are conducted. The discharge voltage and current are measured with a high-voltage probe and a Rogowski coil, respectively, to determine whether the discharge is successful. Generally, the discharge success rate increases as the discharge voltage increases, and it decreases as the electrode gap and the number of ignitions increases. The theoretical analysis and the experimental results are reasonably consistent. This approach provides a reference for designing APPTs and improving their stability.

  17. 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.

  18. Beyond feast and famine: Selecting a PHA accumulating photosynthetic mixed culture in a permanent feast regime.

    PubMed

    Fradinho, J C; Reis, M A M; Oehmen, A

    2016-11-15

    Currently, the feast and famine (FF) regime is the most widely applied strategy to select for polyhydroxyalkanoate (PHA) accumulating organisms in PHA production systems with mixed microbial cultures. As an alternative to the FF regime, this work studied the possibility of utilizing a permanent feast regime as a new operational strategy to select for PHA accumulating photosynthetic mixed cultures (PMCs). The PMC was selected in an illuminated environment and acetate was constantly present in the mixed liquor to guarantee a feast regime. During steady-state operation, the culture presented low PHA accumulation levels, likely due to low light availability, which resulted in most of the acetate being used for biomass growth (Yx/s of 0.64 ± 0.18 Cmol X/Cmol Acet). To confirm the light limitation on the PMC, SBR tests were conducted with higher light availability, at similar levels as would be expectable from natural sunlight. In this case, the Yx/s reduced to 0.11 ± 0.01 Cmol X/Cmol Acet and the culture presented a PHB production yield on acetate of 0.67 ± 0.01 Cmol PHB/Cmol Acet, leading to a maximum PHB content of 60%. Unlike other studied PMCs, the PMC was capable of simultaneous growth and PHB accumulation continuously throughout the cycle. Thus far, 60% PHA content is the maximum value ever reported for a PMC, a result that prospects the utilization of feast regimes as an alternative strategy for the selection of PHA accumulating PMCs. Furthermore, the PMC also presented high phosphate removal rates, delivering an effluent that complies with phosphate discharge limits. The advantages of selecting PMCs under a permanent feast regime are that no aeration inputs are required; it allows higher PHA contents and phosphate removal rates in comparison to FF-operated PMC systems; and it represents a novel means of integrating wastewater treatment with resource recovery in the form of PHA. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. 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.

  20. Atmospheric sampling glow discharge ionization source

    DOEpatents

    McLuckey, Scott A.; Glish, Gary L.

    1989-01-01

    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.

  1. 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.

  2. Urethral discharge culture

    MedlinePlus

    ... medlineplus.gov/ency/article/003750.htm Urethral discharge culture To use the sharing features on this page, please enable JavaScript. Urethral discharge culture is a laboratory test done on men and ...

  3. 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

  4. 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

  5. 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)

  6. 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.

  7. 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 - ...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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 by...

  13. 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 by...

  14. 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 by...

  15. 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.

  16. Double-discharge stabilization of supersonic CO laser mixtures

    NASA Technical Reports Server (NTRS)

    Srinivasan, G.; Smith, J. A.

    1977-01-01

    Experiments have been conducted to study the applicability of a CW double-discharge stabilization scheme under conditions appropriate for high-energy lasers in supersonic flows. Steady arc-free volume discharges have been produced in a Mach 3 supersonic-flow test cavity using an auxiliary discharge to stabilize the main discharge at low-current densities in N2 and He/CO mixtures. A significant result is the lack of observed plasma E/N changes in response to auxiliary-discharge current changes. Also, where glow discharges were obtained, the energy loading achieved was less than the threshold required for laser operation.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Influence of some gaseous additives on gas-discharge parameters and laser performance of a volume-scaled MIR He-SrBr2 laser

    NASA Astrophysics Data System (ADS)

    Temelkov, K. A.; Slaveeva, S. I.; Lyutov, L.; Vuchkov, N. K.

    2010-10-01

    An active volume scaling in bore and length of He-SrBr2 laser excited in nanosecond pulsed longitudinal discharge is carried out. The optimal temperature regime is found for laser oscillation at several different Sr atom and ion lines. Optimal discharge conditions, such as active zone diameter, vapor pressure, buffer-gas pressure, electrical excitation scheme parameters, average input power, pulse repetition frequency, are found. At multiline operation a record average output power of 4.30 W for the Sr atom lasers is obtained, more than 90 % of which is concentrated on the 6.45-μm Sr atom line. A new discharge tube with furtherly increased active volume in bore is developed. The effect of neon additive to the helium buffer gas on the gas and electron temperatures is investigated.

  5. 75 FR 54873 - Notice of Availability of Final NPDES General Permits MAG910000 and NHG910000 for Discharges From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-09

    ... notice of availability of the final National Pollutant Discharge Elimination System (NPDES) general... contaminated groundwater. Owners and/or operators of facilities with remediation discharges, including those...

  6. Ignition regimes in rapid compression machines

    SciTech Connect

    Grogan, Kevin p; Goldsborough, S. Scott; ihme, matthias

    2015-08-01

    A rapid compression machine is an experimental apparatus used to study ignition chemistry at conditions that are relevant to internal combustion engines and gas turbines. However, due to the operating characteristics of these devices, heat transfer effects and inhomogeneous ignition events can be encountered. Hence, this paper develops a combustion regime diagram, which incorporates these effects in order to better understand physical in uences on the measurements. This diagram employs familiar Damkohler number and Reynolds number scaling, and seeks to provide an operational guide for rapid compression machine experiments. This diagram is compared to experimental data and good agreement is found.

  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. 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.

  9. 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.

  10. 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 - ...

  11. Examination Regimes and Student Achievement

    ERIC Educational Resources Information Center

    Cosentino de Cohen, Clemencia

    2010-01-01

    Examination regimes at the end of secondary school vary greatly intra- and cross-nationally, and in recent years have undergone important reforms often geared towards increasing student achievement. This research presents a comparative analysis of the relationship between examination regimes and student achievement in the OECD. Using a micro…

  12. Chapter 5. Borderlands fire regimes

    Treesearch

    Margot Wilkinson-Kaye; Thomas Swetnam; Christopher R. Baisan

    2006-01-01

    Fire is a keystone process in most natural, terrestrial ecosystems. The vital role that fire plays in controlling the structure of an ecosystem underscores the need for us to increase our knowledge of past and current fire regimes (Morgan and others 1994). Dendrochronological reconstructions of fire histories provide descriptions of past fire regimes across a range of...

  13. Complications after discharge for surgical patients.

    PubMed

    Kable, Ashley; Gibberd, Robert; Spigelman, Allan

    2004-03-01

    To measure the type and frequency of complications for surgical patients 1 month after discharge. A post-discharge patient survey was conducted in 2000 for patients who had undergone one of five elective operations: transurethral resection of the prostate, hysterectomy, major joint replacement, cholecystectomy, herniorrhaphy. Two hundred and fourteen patients (74%) returned the survey forms, which were sent 1 month after surgery. Patients were recruited from two teaching hospitals in the Hunter Area Health Service, New South Wales, Australia. One hundred and thirty-five (63%) patients reported one or more complications and 78 (37%) received treatment for 109 complications. Eighty-six per cent reported pain after discharge and 41% reported moderate to severe pain. Seventeen per cent reported infections after discharge and 94% of these patients were given treatment. Twenty-eight per cent reported bleeding after discharge and 20% of these were given treatment. Eleven (5%) patients were readmitted for treatment of problems related to their surgery including four who required further surgery. One hundred and seventy-two patients accessed a range of health services during the first month after discharge, resulting in 266 occasions of service. Twenty-eight per cent of post-discharge services were unplanned. The lack of post-discharge monitoring conceals information about surgical outcomes. Patient reporting is an effective method of monitoring post-discharge outcomes. There is scope to develop post-discharge services to improve the quality of care in the areas of post-discharge pain management, the use of prophylactic measures and to provide treatment for complications that occur during this period.

  14. 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

  15. 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.

  16. Surface-wave produced discharges in hydrogen: II. Modifications of the discharge structure for varying gas-discharge conditions

    NASA Astrophysics Data System (ADS)

    Paunska, Ts; Schlüter, H.; Shivarova, A.; Tarnev, Kh

    2003-11-01

    The self-consistent structure of diffusion-controlled surface-wave-sustained discharges (SWSDs) in hydrogen is presented in terms of its dependence on the varying gas-discharge conditions (wave-frequency and gas-pressure). First, results for the interrelated variations of the plasma characteristics (concentrations of the ionic (H+, H2+ and H3+) and neutral-gas (H and H2) species, electron and gas temperatures, power Theta absorbed on average by an electron) over a wide range of variation of the electron concentration bar ne (averaged over the discharge cross section) are discussed for different gas-pressures. This exhibits not only the influence of changing gas-pressure but also the influence of varying wave-frequency, since, as is known, the range of the bar ne variation along the plasma columns in SWSDs shifts towards higher bar ne with increase in the wave-frequency. The necessity of using effective ion mobilities for lower pressure is demonstrated. The redistribution—with variation in the electron concentration—of the main processes which contribute to Theta is shown. Next, the complete structure of microwave and rf-discharges is shown by also including the resulting axial profiles of electron concentrations and wave characteristics (wavenumber and space damping rate). The wave behaviour is described in radially inhomogeneous plasmas with arbitrary collisions. With the choice of rf- and microwave-discharges, the results obtained cover regimes of weak and strong collisions. The type of electron heating in the wave field is discussed. The influence of changing the wall temperature as well as of varying the wall temperature along the discharge length is described. Finally, effects related to the radial plasma-density inhomogeneity and changing radius of the discharge tube are presented.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. TREHS: An open-access software tool for investigating and evaluating temporary river regimes as a first step for their ecological status assessment.

    PubMed

    Gallart, Francesc; Cid, Núria; Latron, Jérôme; Llorens, Pilar; Bonada, Núria; Jeuffroy, Justin; Jiménez-Argudo, Sara-María; Vega, Rosa-María; Solà, Carolina; Soria, Maria; Bardina, Mònica; Hernández-Casahuga, Antoni-Josep; Fidalgo, Aránzazu; Estrela, Teodoro; Munné, Antoni; Prat, Narcís

    2017-12-31

    When the regime of a river is not perennial, there are four main difficulties with the use of hydrographs for assessing hydrological alteration: i) the main hydrological features relevant for biological communities are not quantitative (discharges) but qualitative (phases such as flowing water, stagnant pools or lack of surface water), ii) stream flow records do not inform on the temporal occurrence of stagnant pools, iii) as most of the temporary streams are ungauged, their regime has to be evaluated by alternative methods such as remote sensing or citizen science, and iv) the biological quality assessment of the ecological status of a temporary stream must follow a sampling schedule and references adapted to the flow- pool-dry regime. To overcome these challenges within an operational approach, the freely available software tool TREHS has been developed within the EU LIFE TRIVERS project. This software permits the input of information from flow simulations obtained with any rainfall-runoff model (to set an unimpacted reference stream regime) and compares this with the information obtained from flow gauging records (if available) and interviews with local people, as well as instantaneous observations by individuals and interpretation of ground-level or aerial photographs. Up to six metrics defining the permanence of water flow, the presence of stagnant pools and their temporal patterns of occurrence are used to determine natural and observed river regimes and to assess the degree of hydrological alteration. A new regime classification specifically designed for temporary rivers was developed using the metrics that measure the relative permanence of the three main phases: flow, disconnected pools and dry stream bed. Finally, the software characterizes the differences between the natural and actual regimes, diagnoses the hydrological status (degree of hydrological alteration), assesses the significance and robustness of the diagnosis and recommends the best periods

  7. 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.

  8. 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.

  9. 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)

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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.

  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. 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 ...

  19. The one-particle approximation in the reflecting discharge simulation

    NASA Astrophysics Data System (ADS)

    Schitov, N. N.; Yurkov, D. I.

    2017-05-01

    The method of some reflecting discharge (Penning discharge) characteristics computation, based on the one-particle approximation is proposed. This discharge is widely used in ion sources aimed at surface modification. However, only the steady state of this discharge is sufficiently described, whereas pulsed modes are preferable in many cases. In fact, the proposed method is similar to the approach used in the early times of first glow discharge investigations and crossed fields ion sources. It may be applied for the early discharge stages (the Townsend regime) description. It is somehow simpler than the diffusion-drift approximation used as a rule for the stationary state description, because plasma does not exist yet. On the other hand, one need not use most of usual diffusion-drift simplifications e.g. 1 or 2D models, uniform magnetic field etc. So the process of discharge formation may be described exactly for different kinds of Penning cells geometries and fields configurations. The discharge ignition condition for the Penning cell, analogous to the Townsend law is evaluated. It allows one to appreciate the discharge formation time as a function of cell geometric parameters, field configurations, anode voltage and Townsend’s coefficients α and γ. This time, or exactly the trajectory length during this time, plays the role of the Townsend parameter d - the distance between electrodes. The calculated values of such times show good agreement with experimental data.

  20. Influence of Wall Conditioning on ADITYA Plasma Discharges

    NASA Astrophysics Data System (ADS)

    Tanna, R. L.; Jadeja, K. A.; Bhatt, S. B.; Bawankar, P. S.; Gupta, C. N.; Joisa, Y. S.; Atrey, P. K.; Manchanda, R.; Ramaiya, Nilam; Ghosh, J.; Raju, D.; Chattopadhyay, P. K.; Jha, R.; the Aditya Team

    2012-11-01

    ADITYA (R0 = 75 cm, a = 25 cm), an ohmically heated circular limiter tokamak is regularly being operated to carry out several experiments related to controlled thermonuclear fusion research. In recent operational campaign, various experiments have been carried out to enhance the discharge performance as well as improve the plasma parameters. A comparative plasma discharges study with SiC and Graphite limiter was carried out to increase the plasma heating and reduce runaways. Excellent plasma heating has been observed in many discharges using Graphite limiter. Good repeatability of low hard X-rays, high temperature discharges was obtained. The control of plasma impurities and hydrogen recycling is very much essential for high performance discharges. The wall conditioning in ADITYA tokamak is carried out by hydrogen glow discharge cleaning (GDC), Pulse discharge cleaning and electron cyclotron resonance (ECR) discharge cleaning techniques with and without lithium wall coating. GDC assisted Lithiumization was found to be the most effective technique for substantial reduction in Ha and low Z (CIII & O-I) impurities. The partial pressure of mass number 18 (H2O) and 28 (N2/C2H4/CO) were regularly monitored before plasma discharge operation. Furthermore, experiment on optimization of pulse gas feed was helped in reducing wall loading and recycling. However, hard X-rays suppression with the application of multiple gas puff has been successfully achieved during negative converter operation, which led to the extension of plasma pulse length up to ~ 250 ms. All the supporting facts and operation aspects are reported.

  1. 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.

  2. 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.

  3. 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

  4. Advanced high frequency partial discharge measuring system

    NASA Technical Reports Server (NTRS)

    Karady, George G.

    1994-01-01

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

  5. Lower hybrid current drive at high density in the multi-pass regime

    SciTech Connect

    Wallace, G. M.; Faust, I. C.; Meneghini, O.; Parker, R. R.; Shiraiwa, S.; Baek, S. G.; Bonoli, P. T.; Hubbard, A. E.; Hughes, J. W.; LaBombard, B. L.; Lau, C.; Ma, Y.; Reinke, M. L.; Terry, J. L.; Whyte, D. G.; Wright, J. C.; Wukitch, S. J.; Schmidt, A. E.; Harvey, R. W.; Smirnov, A. P.; and others

    2012-06-15

    Assessing the performance of lower hybrid current drive (LHCD) at high density is critical for developing non-inductive current drive systems on future steady-state experiments. Excellent LHCD efficiency has been observed during fully non-inductive operation ({eta}=2.0-2.5 Multiplication-Sign 10{sup 19} AW{sup -1}m{sup -2} at n{sub e}=0.5 Multiplication-Sign 10{sup 20} m{sup -3}) on Alcator C-Mod [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)] under conditions (n{sub e}, magnetic field and topology, and LHCD frequency) relevant to ITER [S. Shiraiwa et al., Nucl. Fusion 51, 103024 (2011)]. To extend these results to advanced tokamak regimes with higher bootstrap current fractions on C-Mod, it is necessary to increase n{sub e} to 1.0-1.5 Multiplication-Sign 10{sup 20} m{sup -3}. However, the number of current-carrying, non-thermal electrons generated by LHCD drops sharply in diverted configurations at densities that are well below the density limit previously observed on limited tokamaks. In these cases, changes in scrape off layer (SOL) ionization and density profiles are observed during LHCD, indicating that significant power is transferred from the LH waves to the SOL. Fokker-Planck simulations of these discharges utilizing ray tracing and full wave propagation codes indicate that LH waves in the high density, multi-pass absorption regime linger in the plasma edge, and SOL region, where absorption near or outside the LCFS results in the loss of current drive efficiency. Modeling predicts that non-thermal emission increases with stronger single-pass absorption. Experimental data show that increasing T{sub e} in high density LH discharges results in higher non-thermal electron emission, as predicted by the models.

  6. 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.

  7. 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 ...

  8. Vaginal delivery - discharge

    MedlinePlus

    Skip navigation U.S. National Library of Medicine The navigation menu has been collapsed. ... //medlineplus.gov/ency/patientinstructions/000628.htm Vaginal delivery - discharge To use the sharing features on this page, ...

  9. ACL reconstruction - discharge

    MedlinePlus

    ... discharge References Micheo W, Amy E, Sepulveda F. Anterior cruciate ligament tear. In: Frontera WR, Silver JK, Rizzo TD, eds. Essentials of Physical Medicine and Rehabilitation . 3rd ed. Philadelphia, PA: Elsevier ...

  10. 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 ...

  11. 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 ...

  12. 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 ...

  13. 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 ...

  14. Abdominal radiation - discharge

    MedlinePlus

    Radiation - abdomen - discharge; Cancer - abdominal radiation; Lymphoma - abdominal radiation ... When you have radiation treatment for cancer, your body goes through changes. About 2 weeks after radiation treatment starts, you might notice changes ...

  15. 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 ...

  16. 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 ...

  17. Heart failure - discharge

    MedlinePlus

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

  18. 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 ...

  19. 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 ...

  20. 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 ...