Observations of a mode transition in a hydrogen hollow cathode discharge using phase resolved optical emission spectroscopy

NASA Astrophysics Data System (ADS)

Dixon, Sam; Charles, Christine; Dedrick, James; Gans, Timo; O'Connell, Deborah; Boswell, Rod

2014-07-01

Two distinct operational modes are observed in a radio frequency (rf) low pressure hydrogen hollow cathode discharge. The mode transition is characterised by a change in total light emission and differing expansion structures. An intensified CCD camera is used to make phase resolved images of Balmer α emission from the discharge. The low emission mode is consistent with a typical γ discharge, and appears to be driven by secondary electrons ejected from the cathode surface. The bright mode displays characteristics common to an inductive discharge, including increased optical emission, power factor, and temperature of the H2 gas. The bright mode precipitates the formation of a stationary shock in the expansion, observed as a dark region adjacent to the source-chamber interface.

Development of Repulsive Barrier Discharge from Twin Needles

NASA Astrophysics Data System (ADS)

Ueno, Hideki; Hata, Koji; Nakayama, Hiroshi

2007-03-01

Barrier discharge characteristics have been investigated for a twin needles-to-plane electrode configuration in dry air. The characteristics of barrier discharge under ac voltage application have been investigated for various distances between two needle tips (d=1.0--4.0 mm). We have found that corona discharge behavior strongly depends on needle-tip distance. In the case of a twin-needles configuration with a long needle-tip distance (d=4.0 mm), discharges from the two needle tips develop into a dielectric barrier with almost a straight path. On the contrary, the development of repulsive discharges from two needle tips in the gap between needles and a barrier was obtained for the shortest needle-tip distance investigated here (d=1.0 mm) and it was enhanced by increasing the peak voltage. From detailed time-resolved observations, development of repulsive discharge was observed only during positive polarity upon ac voltage application. Moreover, the degree of repulsion increased with increasing applied voltage of positive polarity. The observed unique discharge behavior can be interpreted as the effect of field relaxation induced not only by charge accumulation on the barrier surface, which is markedly enhanced at a short needle-tip distance, but also by space charge by coronas between two needles.

New Raman-peak at 1850 cm(-1) observed in multiwalled carbon nanotubes produced by hydrogen arc discharge.

PubMed

Chen, B; Kadowaki, Y; Inoue, S; Ohkohchi, M; Zhao, X; Ando, Y

2010-06-01

The new peak (near 1850 cm(-1)) assigned to carbon linear chain included in the centre of very thin innermost multiwalled carbon nanotubes (MWNTs) has been verified by Raman spectroscopy. These MWNTs were produced by dc arc discharge of pure graphite rods in pure hydrogen gas and existed in the cathode deposit. In this paper, we clarified that the new Raman-peaks could also be observed in the cathode deposit including MWNTs produced by hydrogen dc arc discharge using graphite electrode with added Y or La. By changing the quantity of addition (Y or La), dc arc current and pressure of ambient hydrogen gas, the optimum condition to get maximum intensity of the new Raman-peaks was obtained. For the case of 1 wt% La, dc 50 A, H2 pressure of 50 Torr was found to be optimum, and the intensity of new Raman-peak was even higher than the G-band peak. For the case of 1 wt% Y, dc 50 A, H2 pressure of 50 Torr was optimum, but the intensity of new Raman-peak was weaker than the G-band peak. Transmission electron microscopy observation revealed that the crystallinity of MWNTs produced with pure graphite rod was better than those produced with added Y or La.

Comparison of modelled runoff with observed proglacial discharge across the western margin of the Greenland ice sheet

NASA Astrophysics Data System (ADS)

Moustafa, S.; Rennermalm, A.; van As, D.; Overeem, I.; Tedesco, M.; Mote, T. L.; Koenig, L.; Smith, L. C.; Hagedorn, B.; Sletten, R. S.; Mikkelsen, A. B.; Hasholt, B.; Hall, D. K.; Fettweis, X.; Pitcher, L. H.; Hubbard, A.

2017-12-01

Greenland ice sheet surface ablation now dominates its total mass loss contributions to sea-level rise. Despite the increasing importance of Greenland's sea-level contribution, a quantitative inter-comparison between modeled and measured melt, runoff and discharge across multiple drainage basins is conspicuously lacking. Here we investigate the accuracy of model discharge estimates from the Modèle Atmosphérique Régionale (MAR v3.5.2) regional climate model by comparison with in situ proglacial river discharge measurements at three West Greenland drainage basins - North River (Thule), Watson River (Kangerlussuaq), and Naujat Kuat River (Nuuk). At each target catchment, we: 1) determine optimal drainage basin delineations; 2) assess primary drivers of melt; 3) evaluate MAR at daily, 5-, 10- and 20-day time scales; and 4) identify potential sources for model-observation discrepancies. Our results reveal that MAR resolves daily discharge variability poorly in the Nuuk and Thule basins (r2 = 0.4-0.5), but does capture variability over 5-, 10-, and 20-day means (r2 > 0.7). Model agreement with river flow data, though, is reduced during periods of peak discharge, particularly for the exceptional melt and discharge events of July 2012. Daily discharge is best captured by MAR across the Watson River basin, whilst there is lower correspondence between modeled and observed discharge at the Thule and Naujat Kuat River basins. We link the main source of model error to an underestimation of cloud cover, overestimation of surface albedo, and apparent warm bias in near-surface air temperatures. For future inter-comparison, we recommend using observations from catchments that have a self-contained and well-defined drainage area and an accurate discharge record over variable years coincident with a reliable automatic weather station record. Our study highlights the importance of improving MAR modeled surface albedo, cloud cover representation, and delay functions to reduce model

Vibrational kinetics in CO electric discharge lasers - Modeling and experiments

NASA Technical Reports Server (NTRS)

Stanton, A. C.; Hanson, R. K.; Mitchner, M.

1980-01-01

A model of CO laser vibrational kinetics is developed, and predicted vibrational distributions are compared with measurements. The experimental distributions were obtained at various flow locations in a transverse CW discharge in supersonic (M = 3) flow. Good qualitative agreement is obtained in the comparisons, including the prediction of a total inversion at low discharge current densities. The major area of discrepancy is an observed loss in vibrational energy downstream of the discharge which is not predicted by the model. This discrepancy may be due to three-dimensional effects in the experiment which are not included in the model. Possible kinetic effects which may contribute to vibrational energy loss are also examined.

MHD modeling of DIII-D QH-mode discharges and comparison to observations

NASA Astrophysics Data System (ADS)

King, Jacob

2016-10-01

MHD modeling of DIII-D QH-mode discharges and comparison to observations Nonlinear NIMROD simulations, initialized from a reconstruction of a DIII-D QH-mode discharge with broadband MHD, saturate into a turbulent state, but do not saturate when flow is not included. This is consistent with the experimental results of the quiescent regime observed on DIII-D with broadband MHD activity [Garofalo et al., PoP (2015) and refs. within]. These ELM-free discharges have the normalized pedestal-plasma confinement necessary for burning-plasma operation on ITER. Relative to QH-mode operation with more coherent MHD activity, operation with broadband MHD tends to occur at higher densities and lower rotation and thus may be more relevant to ITER. The nonlinear NIMROD simulations require highly accurate equilibrium reconstructions. Our equilibrium reconstructions include the scrape-off-layer profiles and the measured toroidal and poloidal rotation profiles. The simulation develops into a saturated turbulent state and the n=1 and 2 modes become dominant through an inverse cascade. Each toroidal mode in the range of n=1-5 is dominant at a different time. The perturbations are advected and sheared apart in the counter-clockwise direction consistent with the direction of the poloidal flow inside the LCFS. Work towards validation through comparison to magnetic coil and Doppler reflectometry measurements is presented. Consistent with experimental observations during QH-mode, the simulated state leads to large particle transport relative to the thermal transport. Analysis shows that the phase of the density and temperature perturbations differ resulting in greater convective particle transport relative to the convective thermal transport. This work supported by the U.S. Department of Energy Office of Science and the SciDAC Center for Extended MHD Modeling under Contract Numbers DE-FC02-06ER54875, DE-FC02-08ER54972 and DE-FC02-04ER54698.

Electric-discharge-pumped nitrogen ion laser

NASA Technical Reports Server (NTRS)

Laudenslager, J. B.; Pacala, T. J.; Wittig, C.

1976-01-01

The routine operation is described of an N2(+) laser oscillating on the first negative band system of N2(+) which is produced in a preionized transverse discharge device. The discharge design incorporates features which favor the efficient production of the excitation transfer reaction of He2(+) with N2. A capacitive discharge switched by means of a high-current grounded grid thyratron is used to meet the design requirement of a volumetric discharge in high-pressure gas mixtures where the electric discharge need not have an ultrafast rise time (greater than 10 nsec) but should be capable of transferring large quantities of stored electric energy to the gas. A peak power of 180 kW in an 8-nsec laser pulse was obtained with a 0.1% mixture of N2 in helium at a total pressure of 3 atm. The most intense laser oscillations were observed on the (0,1) vibrational transition at 427.8 microns.

Plasma Discharge Process in a Pulsed Diaphragm Discharge System

NASA Astrophysics Data System (ADS)

Duan, Jianjin; Hu, Jue; Zhang, Chao; Wen, Yuanbin; Meng, Yuedong; Zhang, Chengxu

2014-12-01

As one of the most important steps in wastewater treatment, limited study on plasma discharge process is a key challenge in the development of plasma applications. In this study, we focus on the plasma discharge process of a pulsed diaphragm discharge system. According to the analysis, the pulsed diaphragm discharge proceeds in seven stages: (1) Joule heating and heat exchange stage; (2) nucleated site formation; (3) plasma generation (initiation of the breakdown stage); (4) avalanche growth and plasma expansion; (5) plasma contraction; (6) termination of the plasma discharge; and (7) heat exchange stage. From this analysis, a critical voltage criterion for breakdown is obtained. We anticipate this finding will provide guidance for a better application of plasma discharges, especially diaphragm plasma discharges.

Hydrometeorology as an Inversion Problem: Can River Discharge Observations Improve the Atmosphere by Ensemble Data Assimilation?

NASA Astrophysics Data System (ADS)

Sawada, Yohei; Nakaegawa, Tosiyuki; Miyoshi, Takemasa

2018-01-01

We examine the potential of assimilating river discharge observations into the atmosphere by strongly coupled river-atmosphere ensemble data assimilation. The Japan Meteorological Agency's Non-Hydrostatic atmospheric Model (JMA-NHM) is first coupled with a simple rainfall-runoff model. Next, the local ensemble transform Kalman filter is used for this coupled model to assimilate the observations of the rainfall-runoff model variables into the JMA-NHM model variables. This system makes it possible to do hydrometeorology backward, i.e., to inversely estimate atmospheric conditions from the information of river flows or a flood on land surfaces. We perform a proof-of-concept Observing System Simulation Experiment, which reveals that the assimilation of river discharge observations into the atmospheric model variables can improve the skill of the short-term severe rainfall forecast.

River Discharge and Bathymetry Estimation from Hydraulic Inversion of Surface Currents and Water Surface Elevation Observations

NASA Astrophysics Data System (ADS)

Simeonov, J.; Holland, K. T.

2015-12-01

We developed an inversion model for river bathymetry and discharge estimation based on measurements of surface currents, water surface elevation and shoreline coordinates. The model uses a simplification of the 2D depth-averaged steady shallow water equations based on a streamline following system of coordinates and assumes spatially uniform bed friction coefficient and eddy viscosity. The spatial resolution of the predicted bathymetry is related to the resolution of the surface currents measurements. The discharge is determined by minimizing the difference between the predicted and the measured streamwise variation of the total head. The inversion model was tested using in situ and remote sensing measurements of the Kootenai River east of Bonners Ferry, ID. The measurements were obtained in August 2010 when the discharge was about 223 m3/s and the maximum river depth was about 6.5 m. Surface currents covering a 10 km reach with 8 m spatial resolution were estimated from airborne infrared video and were converted to depth-averaged currents using acoustic Doppler current profiler (ADCP) measurements along eight cross-stream transects. The streamwise profile of the water surface elevation was measured using real-time kinematic GPS from a drifting platform. The value of the friction coefficient was obtained from forward calibration simulations that minimized the difference between the predicted and measured velocity and water level along the river thalweg. The predicted along/cross-channel water depth variation was compared to the depth measured with a multibeam echo sounder. The rms error between the measured and predicted depth along the thalweg was found to be about 60cm and the estimated discharge was 5% smaller than the discharge measured by the ADCP.

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

NASA Astrophysics Data System (ADS)

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

2011-06-01

The hydroxyl radical (OH) plays an important role in plasma chemistry at atmospheric pressure. OH radicals have a higher oxidation potential compared with other oxidative species such as free radical O, atomic oxygen, hydroperoxyl radical (HO2), hydrogen peroxide(H2O2) and ozone. In this study, surface discharges on liquids (water and its solutions) were investigated experimentally. A pulsed streamer discharge was generated on the liquid surface using a point-to-plane electrode geometry. The primary generation process of OH radicals is closely related to the streamer propagation, and the subsequent secondary process after the discharge has an influence on the chemical reaction. Taking into account the timescale of these processes, we investigated the behavior of OH radicals using two different diagnostic methods. Time evolution of the ground-state OH radicals above the liquid surface after the discharge was observed by a laser-induced fluorescence (LIF) technique. In order to observe the ground-state OH, an OH [A 2∑+(v' = 1) <-- X 2Π(v'' = 0)] system at 282 nm was used. As the secondary process, a portion of OH radicals diffused from gas phase to the liquid surface and dissolved in the liquid. These dissolved OH radicals were measured by a chemical probe method. Terephthalic acid was used as an OH radical trap and fluorescence of the resulting 2-hydroxyterephthalic acid was measured. This paper directly presents visualization of OH radicals over the liquid surface by means of LIF, and indirectly describes OH radicals dissolved in water by means of a chemical method.

The cloud-ionosphere discharge: a newly observed thunderstorm phenomenon.

PubMed

Winckler, J R

1997-09-30

This paper deals with a luminous electric discharge that forms in the mesospheric region between thundercloud tops and the ionosphere at 90-km altitude. These cloud-ionosphere discharges (CIs), following visual reports dating back to the 19th century, were finally imaged by a low-light TV camera as part of the "SKYFLASH" program at the University of Minnesota in 1989. Many observations were made by various groups in the period 1993-1996. The characteristics of CIs are that they have a wide range of sizes from a few kilometers up to 50 km horizontally; they extend from 40 km to nearly 90 km vertically, with an intense region near 60-70 km and streamers extending down toward cloud tops; the CIs are partly or entirely composed of vertical luminous filaments of kilometer size. The predominate color is red. The TV images show that the CIs usually have a duration less than one TV field (16.7 ms), but higher-speed photometric measurements show that they last about 3 ms, and are delayed 3 ms after an initiating cloud-ground lightning stroke; 95% of these initiating strokes are found to be "positive"-i.e., carry positive charges from clouds to ground. The preference for positive initiating strokes is not understood. Theories of the formation of CIs are briefly reviewed.

The cloud–ionosphere discharge: A newly observed thunderstorm phenomenon

PubMed Central

Winckler, John R.

1997-01-01

This paper deals with a luminous electric discharge that forms in the mesospheric region between thundercloud tops and the ionosphere at 90-km altitude. These cloud–ionosphere discharges (CIs), following visual reports dating back to the 19th century, were finally imaged by a low-light TV camera as part of the “SKYFLASH” program at the University of Minnesota in 1989. Many observations were made by various groups in the period 1993–1996. The characteristics of CIs are that they have a wide range of sizes from a few kilometers up to 50 km horizontally; they extend from 40 km to nearly 90 km vertically, with an intense region near 60–70 km and streamers extending down toward cloud tops; the CIs are partly or entirely composed of vertical luminous filaments of kilometer size. The predominate color is red. The TV images show that the CIs usually have a duration less than one TV field (16.7 ms), but higher-speed photometric measurements show that they last about 3 ms, and are delayed 3 ms after an initiating cloud–ground lightning stroke; 95% of these initiating strokes are found to be “positive”—i.e., carry positive charges from clouds to ground. The preference for positive initiating strokes is not understood. Theories of the formation of CIs are briefly reviewed. PMID:11038577

A prospective observational study comparing a physiological scoring system with time-based discharge criteria in pediatric ambulatory surgical patients.

PubMed

Armstrong, James; Forrest, Helen; Crawford, Mark W

2015-10-01

Discharge criteria based on physiological scoring systems can be used in the postanesthesia care unit (PACU) to fast-track patients after ambulatory surgery; however, studies comparing physiological scoring systems with traditional time-based discharge criteria are lacking. The purpose of this study was to compare PACU discharge readiness times using physiological vs time-based discharge criteria in pediatric ambulatory surgical patients. We recorded physiological observations from consecutive American Society of Anesthesiologists physical status I-III patients aged 1-18 yr who were admitted to the PACU after undergoing ambulatory surgery in a tertiary academic pediatric hospital. The physiological score was a combination of the Aldrete and Chung systems. Scores were recorded every 15 min starting upon arrival in the PACU. Patients were considered fit for discharge once they attained a score ≥12 (maximum score, 14), provided no score was zero, with the time to achieve a score ≥12 defining the criteria-based discharge (CBD) time. Patients were discharged from the PACU when both the CBD and the existing time-based discharge (TBD) criteria were met. The CBD and TBD data were compared using Kaplan-Meier and log-rank analysis. Observations from 506 children are presented. Median (interquartile range [IQR]) age was 5.5 [2.8-9.9] yr. Median [IQR] CBD and TBD PACU discharge readiness times were 30 [15-45] min and 60 [45-60] min, respectively. Analysis of Kaplan-Meier curves indicated a significant difference in discharge times using the different criteria (hazard ratio, 5.43; 95% confidence interval, 4.51 to 6.53; P < 0.001). All patients were discharged home without incident. This prospective study suggests that discharge decisions based on physiological criteria have the potential for significantly speeding the transit of children through the PACU, thereby enhancing PACU efficiency and resource utilization.

Stage-discharge relationship in tidal channels

NASA Astrophysics Data System (ADS)

Kearney, W. S.; Mariotti, G.; Deegan, L.; Fagherazzi, S.

2016-12-01

Long-term records of the flow of water through tidal channels are essential to constrain the budgets of sediments and biogeochemical compounds in salt marshes. Statistical models which relate discharge to water level allow the estimation of such records from more easily obtained records of water stage in the channel. While there is clearly structure in the stage-discharge relationship, nonlinearity and nonstationarity of the relationship complicates the construction of statistical stage-discharge models with adequate performance for discharge estimation and uncertainty quantification. Here we compare four different types of stage-discharge models, each of which is designed to capture different characteristics of the stage-discharge relationship. We estimate and validate each of these models on a two-month long time series of stage and discharge obtained with an Acoustic Doppler Current Profiler in a salt marsh channel. We find that the best performance is obtained by models which account for the nonlinear and time-varying nature of the stage-discharge relationship. Good performance can also be obtained from a simplified version of these models which approximates the fully nonlinear and time-varying models with a piecewise linear formulation.

Feasibility of early discharge after implantable cardioverter-defibrillator procedures.

PubMed

Choudhuri, Indrajit; Desai, Dipan; Walburg, Jon; August, Phyllis; Keller, Seth I; Suri, Ranjit

2012-10-01

Registry data demonstrate considerably low complication rates after implantable cardioverter-defibrillator (ICD) procedures for primary prevention of sudden death. Yet standard of care includes postimplant overnight in-hospital observation that may levy substantial unnecessary financial burden on health care systems. In appropriate patients, discharge soon after implant could translate into significant cost savings, if such practice does not result in complications. We applied a simple clinical algorithm to assess feasibility of discharge on the same day of ICD implantation in patients at low risk for procedural complications. We prospectively randomized primary prevention ICD candidates at low risk for complications (not pacing-dependent or requiring bridging heparin anticoagulation) to next-day discharge with overnight in-hospital observation, or same-day discharge with remote monitoring for 24 hours after ICD implant. Implants were performed via cephalic vein access, and randomization occurred after 4-hours clinical observation and device interrogation. All patients were followed for a minimum of 6 weeks to assess acute procedural complications. 71 patients comprised the study cohort (mean age 62, 79% male) after 3 were excluded. The most common indication for ICD implant was ischemic cardiomyopathy with ejection fraction ≤35%. Device data obtained through 24-hour remote monitoring was comparable to 4-hour postimplant parameters in same-day discharge patients. No acute complications occurred in same-day discharge patients; 1 next-day discharge patient developed pneumothorax. ICD implantation with same-day discharge is reasonable in patients at low risk for complications. Remote monitoring can be useful in indicating lead-parameter stability during the immediate postoperative period. © 2012 Wiley Periodicals, Inc.

Estimation of Uncertainties in Stage-Discharge Curve for an Experimental Himalayan Watershed

NASA Astrophysics Data System (ADS)

Kumar, V.; Sen, S.

2016-12-01

Various water resource projects developed on rivers originating from the Himalayan region, the "Water Tower of Asia", plays an important role on downstream development. Flow measurements at the desired river site are very critical for river engineers and hydrologists for water resources planning and management, flood forecasting, reservoir operation and flood inundation studies. However, an accurate discharge assessment of these mountainous rivers is costly, tedious and frequently dangerous to operators during flood events. Currently, in India, discharge estimation is linked to stage-discharge relationship known as rating curve. This relationship would be affected by a high degree of uncertainty. Estimating the uncertainty of rating curve remains a relevant challenge because it is not easy to parameterize. Main source of rating curve uncertainty are errors because of incorrect discharge measurement, variation in hydraulic conditions and depth measurement. In this study our objective is to obtain best parameters of rating curve that fit the limited record of observations and to estimate uncertainties at different depth obtained from rating curve. The rating curve parameters of standard power law are estimated for three different streams of Aglar watershed located in lesser Himalayas by maximum-likelihood estimator. Quantification of uncertainties in the developed rating curves is obtained from the estimate of variances and covariances of the rating curve parameters. Results showed that the uncertainties varied with catchment behavior with error varies between 0.006-1.831 m3/s. Discharge uncertainty in the Aglar watershed streams significantly depend on the extent of extrapolation outside the range of observed water levels. Extrapolation analysis confirmed that more than 15% for maximum discharges and 5% for minimum discharges are not strongly recommended for these mountainous gauging sites.

Observation of the inductive to helicon mode transition in a weakly magnetized solenoidal inductive discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Min-Hyong; Chung, Chin-Wook

2008-10-13

A mode transition from an inductive mode to a helicon mode is observed in a solenoidal inductive discharge immersed in a weak dc magnetic field. The measured electron temperature and the plasma density at the reactor radial boundary show a sudden increase when the magnetic field strength reaches the critical value and the electron cyclotron frequency exceeds the rf driving frequency. These increases are due to the electron heating by the helicon wave. Such increases in the temperature and the density are not observed at the plasma center because the helicon wave cannot propagate to the center of the solenoidalmore » type reactor unless the magnetic field is very high. These results show that the transition of the discharge from the inductive to the helicon mode occurs at the critical magnetic field strength.« less

Determination of discharge during pulsating flow

USGS Publications Warehouse

Thompson, T.H.

1968-01-01

Pulsating flow in an open channel is a manifestation of unstable-flow conditions in which a series of translatory waves of perceptible magnitude develops and moves rapidly downstream. Pulsating flow is a matter of concern in the design and operation of steep-gradient channels. If it should occur at high stages in a channel designed for stable flow, the capacity of the channel may be inadequate at a discharge that is much smaller than that for which the channel was designed. If the overriding translatory wave carries an appreciable part of the total flow, conventional stream-gaging procedures cannot be used to determine the discharge; neither the conventional instrumentation nor conventional methodology is adequate. A method of determining the discharge during pulsating flow was tested in the Santa Anita Wash flood control channel in Arcadia, Calif., April 16, 1965. Observations of the dimensions and velocities of translatory waves were made during a period of controlled reservoir releases of about 100, 200, and 300 cfs (cubic feet per second). The method of computing discharge was based on (1) computation of the discharge in the overriding waves and (2) computation of the discharge in the shallow-depth, or overrun, part of the flow. Satisfactory results were obtained by this method. However, the procedure used-separating the flow into two components and then treating the shallow-depth component as though it were steady--has no theoretical basis. It is simply an expedient for use until laboratory investigation can provide a satisfactory analytical solution to the problem of computing discharge during pulsating flow. Sixteen months prior to the test in Santa Anita Wash, a robot camera had been designed .and programmed to obtain the data needed to compute discharge by the method described above. The photographic equipment had been installed in Haines Creek flood control channel in Los Angeles, Calif., but it had not been completely tested because of the infrequency of

Television image of a large upward electrical discharge above a thunderstorm system

NASA Technical Reports Server (NTRS)

Franz, R. C.; Nemzek, R. J.; Winckler, J. R.

1990-01-01

A low light-level TV camera is used to obtain an unusual image of luminous electrical discharge over a thunderstorm 250 km from the observation site. The image is presented and the discharge in the image is described. It is suggested that the image is probably due to two localized electric charge concentrations at the cloud tops. The hazard of these discharges for aircraft and rocket launches is examined. Consideration is given to the possibility that these discharges may account for unexplained photometric observations of distant lightning events that show a low rise rate of the luminous pulse and no electromagnetic sferic pulse like that in cloud-to-earth lightning strokes. The photometric events of this type that occurred on September 22-23, 1989 during hurricane Hugo are noted.

Characterization of argon dielectric barrier discharges applied to ethyl lactate plasma polymerization

NASA Astrophysics Data System (ADS)

Laurent, Morgane; Desjardins, Edouard; Meichelboeck, Maximilian; Naudé, Nicolas; Stafford, Luc; Gherardi, Nicolas; Laroche, Gaétan

2017-11-01

The influence of the input voltage frequency (35 and 150 kHz), interelectrode gap (1 and 2 mm) and precursor concentration (250, 350, and 450 ppm) on the electron temperature (T e), number density of metastable Ar atoms (n(Ar m )), and discharge current density (proportional to the electron density ne) is studied in an argon-ethyl lactate dielectric barrier discharge (DBD). An argon-ammonia Penning mixture is also considered as reference. These results are correlated to the chemistry (XPS, IR) and topography (AFM) of the ethyl-lactate-based plasma polymer coatings. Low T e values from 0.3 to 0.5 eV were obtained for all discharges. This observation, in addition to resemblances with the Ar-NH3 mixture, suggested that the ionization kinetics of ethyl lactate-based discharges is driven by Penning reactions. Among the investigated parameters, the dissipated power obtained through changes of the excitation frequency had the largest impact on both the coatings properties and the discharge behavior.

Homogeneous dielectric barrier discharges in atmospheric air and its influencing factor

NASA Astrophysics Data System (ADS)

Ran, Junxia; Li, Caixia; Ma, Dong; Luo, Haiyun; Li, Xiaowei

2018-03-01

The stable homogeneous dielectric barrier discharge (DBD) is obtained in atmospheric 2-3 mm air gap. It is generated using center frequency 1 kHz high voltage power supply between two plane parallel electrodes with specific alumina ceramic plates as the dielectric barriers. The discharge characteristics are studied by a measurement of its electrical discharge parameters and observation of its light emission phenomena. The results show that a large single current pulse of about 200 μs duration appearing in each voltage pulse, and its light emission is radially homogeneous and covers the entire surface of the two electrodes. The homogeneous discharge generated is a Townsend discharge during discharge. The influences of applied barrier, its thickness, and surface roughness on the transition of discharge modes are studied. The results show that it is difficult to produce a homogeneous discharge using smooth plates or alumina plate surface roughness Ra < 100 nm even at a 1 mm air gap. If the alumina plate is too thin, the discharge also transits to filamentary discharge. If it is too thick, the discharge is too weak to observe. With the increase of air gap distance and applied voltage, the discharge can also transit from a homogeneous mode to a filamentary mode. In order to generate stable and homogeneous DBD at a larger air gap, proper dielectric material, dielectric thickness, and dielectric surface roughness should be used, and proper applied voltage amplitude and frequency should also be used.

Microstructure Investigation of 13Cr-2Mo ODS Steel Components Obtained by High Voltage Electric Discharge Compaction Technique.

PubMed

Bogachev, Igor; Yudin, Artem; Grigoryev, Evgeniy; Chernov, Ivan; Staltsov, Maxim; Khasanov, Oleg; Olevsky, Eugene

2015-11-02

Refractory oxide dispersion strengthened 13Cr-2Mo steel powder was successfully consolidated to near theoretical density using high voltage electric discharge compaction. Cylindrical samples with relative density from 90% to 97% and dimensions of 10 mm in diameter and 10-15 mm in height were obtained. Consolidation conditions such as pressure and voltage were varied in some ranges to determine the optimal compaction regime. Three different concentrations of yttria were used to identify its effect on the properties of the samples. It is shown that the utilized ultra-rapid consolidation process in combination with high transmitted energy allows obtaining high density compacts, retaining the initial structure with minimal grain growth. The experimental results indicate some heterogeneity of the structure which may occur in the external layers of the tested samples due to various thermal and electromagnetic in-processing effects. The choice of the optimal parameters of the consolidation enables obtaining samples of acceptable quality.

Microstructure investigation of 13Cr-2Mo ODS steel components obtained by high voltage electric discharge compaction technique

DOE PAGES

Bogachev, Igor; Yudin, Artem; Grigoryev, Evgeniy; ...

2015-11-02

Refractory oxide dispersion strengthened 13Cr-2Mo steel powder was successfully consolidated to near theoretical density using high voltage electric discharge compaction. Cylindrical samples with relative density from 90% to 97% and dimensions of 10 mm in diameter and 10–15 mm in height were obtained. Consolidation conditions such as pressure and voltage were varied in some ranges to determine the optimal compaction regime. Three different concentrations of yttria were used to identify its effect on the properties of the samples. It is shown that the utilized ultra-rapid consolidation process in combination with high transmitted energy allows obtaining high density compacts, retaining themore » initial structure with minimal grain growth. The experimental results indicate some heterogeneity of the structure which may occur in the external layers of the tested samples due to various thermal and electromagnetic in-processing effects. As a result, the choice of the optimal parameters of the consolidation enables obtaining samples of acceptable quality.« less

Discharge stabilization studies of CO laser gas mixtures in quasi-steady supersonic flow

NASA Technical Reports Server (NTRS)

Srinivasan, G.; Smith, J. A.

1976-01-01

Experiments were conducted to study the applicability of a double discharge stabilization scheme in conditions appropriate for high energy CO lasers in supersonic flows. A Ludwieg tube impulse flow facility and a ballasted capacitor bank provided essentially steady flow and discharge conditions (d.c.) for times longer than ten electrode length-flow transit times. Steady, arc-free, volume discharges were produced in a Mach 3 test cavity using an auxiliary discharge to stabilize the main discharge in N2 and He/CO mixture. A signigicant 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 very much less than the threshold level required for laser operation.

Langmuir probe measurements of double-layers in a pulsed discharge

NASA Technical Reports Server (NTRS)

Levine, J. S.; Crawford, F. W.

1980-01-01

Langmuir probe measurements were carried out which confirm the occurrence of double-layers in an argon positive column. Pulsing the discharge current permitted probe measurements to be performed in the presence of the double-layer. Supplementary evidence, obtained from DC and pulsed discharges, indicated that the double-layers formed in the two modes of operation were similar. The double-layers observed were weak and stable; their relation to other classes of double-layers are discussed, and directions for future work are suggested.

In-situ observation of NO and NO2 in streamer corona discharge by two-dimensional laser-induced fluorescence spectroscopy

NASA Astrophysics Data System (ADS)

Aramaki, M.; Kurakane, H.; Sasaki, K.

2003-10-01

It is known that most of nitrogenous oxides which are released from factories, cars, and so on are mainly composed NO and NO_2. Hence, it is especially important to examine dissociation processes of NO and NO2 in the research of the NOx removal using high-pressure non-equilibrium plasmas. In-situ observations of NO and NO2 in the plasma reactor are effective to investigate the reaction kinetics of NO_x. In the present work, we measured temporal variations of the density distributions of NO and NO2 in streamer corona discharges between needle and planar electrodes by two-dimensional laser induced fluorescence spectroscopy. The two-dimensional images of the density distributions of NO and NO2 were taken using an ICCD camera. The discharge atmosphere was air including NO2 (1500 ˜2000 ppm) at a pressure of 200 Torr. The NO2 density decreased locally in the region below the needle electrode at 10 ms after the discharge. At the same time, we observed the appearance of NO in the region corresponding to the decay of NO_2. The significant production of NO was not observed when the discharge atmosphere was composed of N2 and NO_2. Therefore, from these experimental results, it is suggested that NO is produced by a reaction NO2 + O arrow NO + O_2.

Impacts of climate change on river discharge in the northern Tien Shan: Results from the long-term observations and modelling

NASA Astrophysics Data System (ADS)

Shahgedanova, Maria; Afzal, Muhammad; Usmanova, Zamira; Kapitsa, Vasilii; Mayr, Elisabeth; Hagg, Wilfried; Severskiy, Igor; Zhumabayev, Dauren

2017-04-01

The study presents results of investigation of the observed and projected changes in discharge of seven snow- and glacier-nourished rivers of the northern Tien Shan (south-eastern Kazakhstan). The observed trends were assessed using the long-term (40-60 years) homogeneous daily records of discharge from the gauging stations located in the mountains and unaffected by human activities including water abstraction. Positive trends in discharge were registered at most sites between the 1950s and 2010s with the strongest increase in summer and autumn particularly in 2000-2010s in line with the positive temperature trends. The observed increase was most prominent in the catchments with a higher proportion of glacierized area. At the Ulken Almatinka and Kishi Almatinka rivers, where 16% and 12% of the catchment areas are glacierized, positive trends in summer and autumn discharge exceeded 1% per year. The strongest increase was observed in September indicating that melting period extends in the early autumn. In September-November, the number of days with extreme discharge values, defined as daily values exceeding 95th percentile (calculated for each meteorological season), increased at all rivers. Future changes in discharge were modelled using HBV-ETH hydrological model and four climate change scenarios derived using regional climate model PRECIS with 25 km spatial resolution driven by HadGEM GCM for RCP 2.6 and RCP 8.5 scenarios and HadCM3Q0 and ECHAM5 GCM for A1B scenario. A range of glacier change scenarios was considered. All climate experiments project increase in temperature with the strongest warming projected by the HadGEM-driven simulation for RCP 8.5 scenario and HadCM3Q0-driven simulation for A1B scenario. The projected changes in precipitation varied between models and seasons, however, most experiments did not show significant trends in precipitation within the studied catchments. The exception is a simulation driven by HadGEM GCM for 8.5 RCP scenario which

Observation of copper atoms behavior in a vacuum arc discharge using laser spectroscopy

NASA Astrophysics Data System (ADS)

Sung, Y. M.; Hayashi, Y.; Okraku-Yirenkyi, Y.; Otsubo, M.; Honda, C.; Sakoda, T.

2003-01-01

In order to investigate the most important parameters influencing the breaking characteristic of a vacuum circuit breaker (VCB), the behavior of copper (Cu) particles emitted from electrodes designed as an imitation of a vacuum valve of the VCB was observed. The temporal-spatial intensity distributions due to Cu particles in an excited state or a neutral state were measured using the laser induced fluorescence (LIF) technique and a charge coupled device camera attached with a special filter. The diffusion velocity of a Cu atom was also investigated by evaluating a Doppler shift of the LIF signal. The results showed that most Cu particles were emitted from the anode and were in an excited state or an ionized state during an arc discharge. Also, Cu particles were distributed between electrodes even after the discharge chocked, and its diffusion velocity in the direction of the cathode from the anode was about 2.6 km/s.

Observations and modelling of subglacial discharge and heat transport in Godthåbsfjord (Greenland, 64 °N)

NASA Astrophysics Data System (ADS)

Bendtsen, Jørgen; Mortensen, John; Rysgaard, Søren

2017-04-01

Subglacial discharge from tidewater outlet glaciers forms convective bouyant freshwater plumes ascending close the glacier face, and entrainment of ambient bottom water increases the salinity of the water until the plume reaches its level of neutral buoyancy at sub-surface levels or reaches the surface. Relatively warm bottom water masses characterize many fjords around Greenland and therefore entrainment would also increase the temperature in the plumes and, thereby, impact the heat transport in the fjords. However, relatively few oceanographic measurements have been made in or near plumes from subglacial discharge and, therefore, the potential for subglacial discharge for increasing heat transport towards the tidewater outlet glaciers are poorly understood. We present the first direct hydrographic measurements in a plume from subglacial discharge in Godthåbsfjord (located on the western coast of Greenland) where a XCTD was launched from a helicopter directly into the plume. Measurements of the surface salinity showed that the plume only contained 7% of freshwater at the surface, implying a large entrainment with a mixing ratio of 1:13 between outflowing meltwater and saline fjord water. These observations are analyzed together with seasonal observations of ocean heat transport towards the tidewater outlet glaciers in Godthåbsfjord and we show that subglacial discharge only had modest effects on the overall heat budget in front of the glacier. These results were supported from a high-resolution three-dimensional model of Godthåbsfjord. The model explicitly considered subglacial freshwater discharge from three tidewater outlet glaciers where entrainment of bottom water was taken into account. Model results showed that subglacial discharge only affected the fjord circulation relatively close ( 10 km) to the glaciers. Thus, the main effect on heat transport was due to the freshwater discharge itself whereas the subsurface discharge and associated entrainment only

Characterizing Long-term Contaminant Mass Discharge and the Relationship Between Reductions in Discharge and Reductions in Mass for DNAPL Source Areas

PubMed Central

Matthieu, D.E.; Carroll, K.C.; Mainhagu, J.; Morrison, C.; McMillan, A.; Russo, A.; Plaschke, M.

2013-01-01

The objective of this study was to characterize the temporal behavior of contaminant mass discharge, and the relationship between reductions in contaminant mass discharge and reductions in contaminant mass, for a very heterogeneous, highly contaminated source-zone field site. Trichloroethene is the primary contaminant of concern, and several lines of evidence indicate the presence of organic liquid in the subsurface. The site is undergoing groundwater extraction for source control, and contaminant mass discharge has been monitored since system startup. The results show a significant reduction in contaminant mass discharge with time, decreasing from approximately 1 to 0.15 kg/d. Two methods were used to estimate the mass of contaminant present in the source area at the initiation of the remediation project. One was based on a comparison of two sets of core data, collected 3.5 years apart, which suggests that a significant (~80%) reduction in aggregate sediment-phase TCE concentrations occurred between sampling events. The second method was based on fitting the temporal contaminant mass discharge data with a simple exponential source-depletion function. Relatively similar estimates, 784 and 993 kg, respectively, were obtained with the two methods. These data were used to characterize the relationship between reductions in contaminant mass discharge (CMDR) and reductions in contaminant mass (MR). The observed curvilinear relationship exhibits a reduction in contaminant mass discharge essentially immediately upon initiation of mass reduction. This behavior is consistent with a system wherein significant quantities of mass are present in hydraulically poorly accessible domains for which mass removal is influenced by rate-limited mass transfer. The results obtained from the present study are compared to those obtained from other field studies to evaluate the impact of system properties and conditions on mass-discharge and mass-removal behavior. The results indicated that

Observations of nearshore groundwater discharge: Kahekili Beach Park submarine springs, Maui, Hawaii

USGS Publications Warehouse

Swarzenski, Peter W.; Dulai, H.; Kroeger, K.D.; Smith, C.G.; Dimova, N.; Storlazzi, C. D.; Prouty, N.G.; Gingerich, S.B.; Glenn, C. R.

2016-01-01

Study regionThe study region encompasses the nearshore, coastal waters off west Maui, Hawaii. Here abundant groundwater—that carries with it a strong land-based fingerprint—discharges into the coastal waters and over a coral reef.Study focusCoastal groundwater discharge is a ubiquitous hydrologic feature that has been shown to impact nearshore ecosystems and material budgets. A unique combined geochemical tracer and oceanographic time-series study addressed rates and oceanic forcings of submarine groundwater discharge at a submarine spring site off west Maui, Hawaii.New hydrological insights for the regionEstimates of submarine groundwater discharge were derived for a primary vent site and surrounding coastal waters off west Maui, Hawaii using an excess 222Rn (t1/2 = 3.8 d) mass balance model. Such estimates were complemented with a novel thoron (220Rn,t1/2 = 56 s) groundwater discharge tracer application, as well as oceanographic time series and thermal infrared imagery analyses. In combination, this suite of techniques provides new insight into the connectivity of the coastal aquifer with the near-shore ocean and examines the physical drivers of submarine groundwater discharge. Lastly, submarine groundwater discharge derived constituent concentrations were tabulated and compared to surrounding seawater concentrations. Such work has implications for the management of coastal aquifers and downstream nearshore ecosystems that respond to sustained constituent loadings via this submarine route.

River discharge estimation from synthetic SWOT-type observations using variational data assimilation and the full Saint-Venant hydraulic model

NASA Astrophysics Data System (ADS)

Oubanas, Hind; Gejadze, Igor; Malaterre, Pierre-Olivier; Mercier, Franck

2018-04-01

The upcoming Surface Water and Ocean Topography satellite mission, to be launched in 2021, will measure river water surface elevation, slope and width, with an unprecedented level of accuracy for a remote sensing tool. This work investigates the river discharge estimation from synthetic SWOT observations, in the presence of strong uncertainties in the model inputs, i.e. the river bathymetry and bed roughness. The estimation problem is solved by a novel variant of the standard variational data assimilation, the '4D-Var' method, involving the full Saint-Venant 1.5D-network hydraulic model SIC2. The assimilation scheme simultaneously estimates the discharge, bed elevation and bed roughness coefficient and is designed to assimilate both satellite and in situ measurements. The method is tested on a 50 km-long reach of the Garonne River during a five-month period of the year 2010, characterized by multiple flooding events. First, the impact of the sampling frequency on discharge estimation is investigated. Secondly, discharge as well as the spatially distributed bed elevation and bed roughness coefficient are determined simultaneously. Results demonstrate feasibility and efficiency of the chosen combination of the estimation method and of the hydraulic model. Assimilation of the SWOT data results into an accurate estimation of the discharge at observation times, and a local improvement in the bed level and bed roughness coefficient. However, the latter estimates are not generally usable for different independent experiments.

Medication details documented on hospital discharge: cross-sectional observational study of factors associated with medication non-reconciliation

PubMed Central

Grimes, Tamasine C; Duggan, Catherine A; Delaney, Tim P; Graham, Ian M; Conlon, Kevin C; Deasy, Evelyn; Jago-Byrne, Marie-Claire; O' Brien, Paul

2011-01-01

AIMS Movement into or out of hospital is a vulnerable period for medication safety. Reconciling the medication a patient is using before admission with the medication prescribed on discharge, and documenting any changes (medication reconciliation) is recommended to improve safety. The aims of the study were to investigate the factors contributing to medication reconciliation on discharge, and identify the prevalence of non-reconciliation. METHODS The study was a cross-sectional, observational survey using consecutive discharges from purposively selected services in two acute public hospitals in Ireland. Medication reconciliation, potential for harm and unplanned re-admission were investigated. RESULTS Medication non-reconciliation was identified in 50% of 1245 inpatient episodes, involving 16% of 9569 medications. The majority of non-reconciled episodes had potential to result in moderate (63%) or severe (2%) harm. Handwritten rather than computerized discharges (adjusted odds ratio (adjusted OR) 1.60, 95% CI 1.11, 2.99), increasing number of medications (adjusted OR 1.26, 95% CI 1.21, 1.31) or chronic illness (adjusted OR 2.08, 95% CI 1.33, 3.24) were associated with non-reconciliation. Omission of endocrine, central nervous system and nutrition and blood drugs was more likely on discharge, whilst omission on admission and throughout inpatient care, without documentation, was more likely for obstetric, gynaecology and urinary tract (OGU) or respiratory drugs. Documentation in the discharge communication that medication was intentionally stopped during inpatient care was less likely for cardiovascular, musculoskeletal and OGU drugs. Errors involving the dose were most likely for respiratory drugs. CONCLUSIONS The findings inform strategies to facilitate medication reconciliation on discharge from acute hospital care. PMID:21284705

Production of fullerenes and single-wall carbon nanotubes by high-temperature pulsed arc discharge

NASA Astrophysics Data System (ADS)

Sugai, Toshiki; Omote, Hideki; Bandow, Shunji; Tanaka, Nobuo; Shinohara, Hisanori

2000-04-01

Fullerenes and single-wall carbon nanotubes (SWNTs) have been produced for the first time by the high-temperature pulsed arc-discharge technique, which has developed in this laboratory. Fullerenes are identified quantitatively by high-performance liquid chromatography (HPLC), and scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations reveal a significant amount of production of bundles of SWNTs in soot. The pulse arc production of fullerenes and SWNTs favors the high-temperature (⩾1000 °C), long pulses (⩾1 ms) and a heavy rare gas such as Ar or Kr as a buffer gas. We have found that fullerenes and SWNTs have complementary relationships in their early stage of production. The details of the pulsed arc discharge have been obtained by observing the transition from the pulsed arc discharge to the steady arc discharge while increasing the pulse width.

Electron-impact ionization and electron attachment cross sections of radicals important in transient gaseous discharges

NASA Technical Reports Server (NTRS)

Lee, Long C.; Srivastava, Santosh K.

1990-01-01

Electron-impact ionization and electron attachment cross sections of radicals and excited molecules were measured using an apparatus that consists of an electron beam, a molecular beam and a laser beam. The information obtained is needed for the pulse power applications in the areas of high power gaseous discharge switches, high energy lasers, particle beam experiments, and electromagnetic pulse systems. The basic data needed for the development of optically-controlled discharge switches were also investigated. Transient current pulses induced by laser irradiation of discharge media were observed and applied for the study of electron-molecule reaction kinetics in gaseous discharges.

The transition mechanism from a symmetric single period discharge to a period-doubling discharge in atmospheric helium dielectric-barrier discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen

2013-06-15

Period-doubling and chaos phenomenon have been frequently observed in atmospheric-pressure dielectric-barrier discharges. However, how a normal single period discharge bifurcates into period-doubling state is still unclear. In this paper, by changing the driving frequency, we study numerically the transition mechanisms from a normal single period discharge to a period-doubling state using a one-dimensional self-consistent fluid model. The results show that before a discharge bifurcates into a period-doubling state, it first deviates from its normal operation and transforms into an asymmetric single period discharge mode. Then the weaker discharge in this asymmetric discharge will be enhanced gradually with increasing of themore » frequency until it makes the subsequent discharge weaken and results in the discharge entering a period-doubling state. In the whole transition process, the spatial distribution of the charged particle density and the electric field plays a definitive role. The conclusions are further confirmed by changing the gap width and the amplitude of the applied voltage.« less

Study of physical properties of metal oxide nanoparticles obtained in acoustoplasma discharge

NASA Astrophysics Data System (ADS)

Bulychev, N. A.; Kazaryan, M. A.; Zakharyan, A. R.; Bodryshev, V. V.; Kirichenko, M. N.; Shevchenko, S. N.; Yakunin, V. G.; Timoshenko, V. Y.; Bychenko, A. B.

2018-04-01

Nanoparticles of tungsten, copper, iron, and zinc oxides were synthesized in acoustoplasma discharge. Their size distribution was studied by electron microscopy and laser correlation spectroscopy. Ultrasound was found to narrow significantly the size distribution width of zinc oxide nanoparticles. Water suspensions of zinc oxide nanoparticles showed photoluminescence in red and near infrared spectral ranges, which makes them a promising material for luminescent diagnostics of biological systems.

Observation and interpretation of energy efficient, diffuse direct current glow discharge at atmospheric pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Jie, E-mail: tangjie1979@opt.ac.cn; Jiang, Weiman; Wang, Yishan

2015-08-24

A diffuse direct-current glow discharge was realized with low energy consumption and high energy utilization efficiency at atmospheric pressure. The formation of diffuse discharge was demonstrated by examining and comparing the electrical properties and optical emissions of plasmas. In combination with theoretical derivation and calculation, we draw guidelines that appearance of nitrogen ions at low electron density is crucial to enhance the ambipolar diffusion for the expansion of discharge channel and the increasing ambipolar diffusion near the cathode plays a key role in the onset of diffuse discharge. An individual-discharge-channel expansion model is proposed to explain the diffuse discharge formation.

Experimental observation of standing wave effect in low-pressure very-high-frequency capacitive discharges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Yong-Xin; Gao, Fei; Liu, Jia

2014-07-28

Radial uniformity measurements of plasma density were carried out by using a floating double probe in a cylindrical (21 cm in electrode diameter) capacitive discharge reactor driven over a wide range of frequencies (27–220 MHz). At low rf power, a multiple-node structure of standing wave effect was observed at 130 MHz. The secondary density peak caused by the standing wave effect became pronounced and shifts toward the axis as the driving frequency further to increase, indicative of a much more shortened standing-wave wavelength. With increasing rf power, the secondary density peak shift toward the radial edge, namely, the standing-wave wavelength was increased,more » in good qualitative agreement with the previous theory and simulation results. At higher pressures and high frequencies, the rf power was primarily deposited at the periphery of the electrode, due to the fact that the waves were strongly damped as they propagated from the discharge edge into the center.« less

Bifurcations in the theory of current transfer to cathodes of DC discharges and observations of transitions between different modes

NASA Astrophysics Data System (ADS)

Bieniek, M. S.; Santos, D. F. N.; Almeida, P. G. C.; Benilov, M. S.

2018-04-01

General scenarios of transitions between different spot patterns on electrodes of DC gas discharges and their relation to bifurcations of steady-state solutions are analyzed. In the case of cathodes of arc discharges, it is shown that any transition between different modes of current transfer is related to a bifurcation of steady-state solutions. In particular, transitions between diffuse and spot modes on axially symmetric cathodes, frequently observed in the experiment, represent an indication of the presence of pitchfork or fold bifurcations of steady-state solutions. Experimental observations of transitions on cathodes of DC glow microdischarges are analyzed and those potentially related to bifurcations of steady-state solutions are identified. The relevant bifurcations are investigated numerically and the computed patterns are found to conform to those observed in the course of the corresponding transitions in the experiment.

Observed Spatial and Temporal Variability of Subglacial Discharge-Driven Plumes in Greenland's Outlet Glacial Fjords

NASA Astrophysics Data System (ADS)

Sutherland, D.; Carroll, D.; Nash, J. D.; Shroyer, E.; Mickett, J.; Stearns, L. A.; Fried, M.; Bartholomaus, T.; Catania, G. A.

2015-12-01

Hydrographic and velocity observations in Greenland's outlet glacier fjords have revealed, unsurprisingly, a rich set of dynamics over a range of spatial and temporal scales. Through teasing apart the distinct processes that control circulation within these fjords, we are likely to better understand the impact of fjord circulation on modulating outlet glacier dynamics, and thus, changes in Greenland Ice Sheet mass balance. Here, we report on data from the summers of 2013-2015 in two neighboring fjords in the Uummannaq Bay region of west Greenland: Kangerlussuup Sermia (KS) and Rink Isbræ (RI). We find strong subglacial discharge driven plumes in both systems that evolve on synoptic and seasonal time scales, without the complicating presence of other circulation processes. The plumes both modify fjord water properties and respond to differences in ambient water properties, supporting the notion that a feedback exists between subglacial discharge plume circulation and water mass properties. This feedback between subglacial discharge and water properties potentially influences submarine melt rates at the glacier termini. Observed plume properties, including the vertical structure of velocity, and temperature and salinity anomalies, are compared favorably to model estimates. In KS, we find a near-surface intensified plume with high sediment content that slows and widens as it evolves downstream. In contrast, the plume in RI is entirely subsurface, ranging from 100-300 m depth at its core during summer, although it shows similar temperature, salinity, and optical backscatter signals to the KS plume. Importantly, the distinct vertical plume structures imprint on the overall water mass properties found in each fjord, raising the minimum temperatures by up to 1-2°C in the case of RI.

Obtaining coincident image observations for Mission to Planet Earth science data return

NASA Technical Reports Server (NTRS)

Newman, Lauri Kraft; Folta, David C.; Farrell, James P.

1994-01-01

One objective of the Mission to Planet Earth (MTPE) program involves comparing data from various instruments on multiple spacecraft to obtain a total picture of the Earth's systems. To correlate image data from instruments on different spacecraft, these spacecraft must be able to image the same location on the Earth at approximately the same time. Depending on the orbits of the spacecraft involved, complicated operational details must be considered to obtain such observations. If the spacecraft are in similar orbits, close formation flying or synchronization techniques may be used to assure coincident observations. If the orbits are dissimilar, the launch time of the second satellite may need to be restricted in order to align its orbit with that of the first satellite launched. This paper examines strategies for obtaining coincident observations for spacecraft in both similar and dissimilar orbits. Although these calculations may be performed easily for coplanar spacecraft, the non-coplanar case involves additional considerations which are incorporated into the algorithms presented herein.

A sociological exploration of the tensions related to interprofessional collaboration in acute-care discharge planning.

PubMed

Goldman, Joanne; Reeves, Scott; Wu, Robert; Silver, Ivan; MacMillan, Kathleen; Kitto, Simon

2016-01-01

Patient discharge is a key concern in hospitals, particularly in acute care, given the multifaceted and challenging nature of patients' healthcare needs. Policies on discharge have identified the importance of interprofessional collaboration, yet research has described its limitations in this clinical context. This study aimed to extend our understanding of interprofessional interactions related to discharge in a general internal medicine setting by using sociological theories to illuminate the existence of, and interplay between, structural factors and microlevel practices. An ethnographic approach was employed to obtain an in-depth insight into healthcare providers' perspectives, behaviours, and interactions regarding discharge. Data collection involved observations, interviews, and document analysis. Approximately 65 hours of observations were undertaken, 23 interviews were conducted with healthcare providers, and government and hospital discharge documents were collected. Data were analysed using a directed content approach. The findings indicate the existence of a medically dominated division of healthcare labour in patient discharge with opportunities for some interprofessional negotiations; the role of organizational routines in facilitating and challenging interprofessional negotiations in patient discharge; and tensions in organizational priorities that impact an interprofessional approach to discharge. The findings provide insight into the various levels at which interventions can be targeted to improve interprofessional collaboration in discharge while recognizing the organizational tensions that challenge an interprofessional approach.

Spectroscopic evidence of α,α-dichlorobenzyl radical produced by corona discharge of benzotrichloride

NASA Astrophysics Data System (ADS)

Yoon, Young Wook; Chae, Sang Youl; Lim, Manho; Lee, Sang Kuk

2015-08-01

We report spectroscopic observations of the α,α-dichlorobenzyl radical obtained by corona excited supersonic jet expansion using a pinhole-type glass nozzle. Vibronically excited but jet-cooled radicals were generated by corona discharge of the precursor benzotrichloride with a large amount of helium carrier gas, from which the visible vibronic emission spectrum was recorded using a long path monochromator. From an analysis of the spectrum observed, the electronic energy of the D1 → D0 transition and a few vibrational mode frequencies in the ground electronic state were obtained for the α,α-dichlorobenzyl radical by comparing observed frequencies with those obtained by ab initio calculation.

Television Image of a Large Upward Electrical Discharge Above a Thunderstorm System

NASA Astrophysics Data System (ADS)

Franz, R. C.; Nemzek, R. J.; Winckler, J. R.

1990-07-01

An image of an unusual luminous electrical discharge over a thunderstorm 250 kilometers from the observing site has been obtained with a low-light-level television camera. The discharge began at the cloud tops at 14 kilometers and extended into the clear air 20 kilometers higher. The image, which had a duration of less than 30 milliseconds, resembled two jets or fountains and was probably caused by two localized electric charge concentrations at the cloud tops. Large upward discharges may create a hazard for aircraft and rocket launches and, by penetrating into the ionosphere, may initiate whistler waves and other effects on a magnetospheric scale. Such upward electrical discharges may account for unexplained photometric observations of distant lightning events that showed a low rise rate of the luminous pulse and no electromagnetic sferic pulse of the type that accompanies cloud-to-earth lightning strokes. An unusually high rate of such photometric events was recorded during the night of 22 to 23 September 1989 during a storm associated with hurricane Hugo.

Television image of a large upward electrical discharge above a thunderstorm system.

PubMed

Franz, R C; Nemzek, R J; Winckler, J R

1990-07-06

An image of an unusual luminous electrical discharge over a thunderstorm 250 kilometers from the observing site has been obtained with a low-light-level television camera. The discharge began at the cloud tops at 14 kilometers and extended into the clear air 20 kilometers higher. The image, which had a duration of less than 30 milliseconds,resembled two jets or fountains and was probably caused by two localizd electric charge concentrations at the cloud tops. Large upward discharges may create a hazard for aircraft and rocket launches and, by penetrating into the ionosphere, may initiate whistler waves and other effects on a magnetospheric scale. Such upward electrical discharges may account for unexplained photometric observations of distant lightning events that showed a low rise rate of the luminous pulse and no electromagnetic sferic pulse of the type that accompanies cloud-to-earth lightning strokes. An unusually high rate of such photometric events was recorded during the night of 22 to 23 September 1989 during a storm associated with hurricane Hugo.

Dicarboxylic acids from electric discharge

NASA Technical Reports Server (NTRS)

Zeitman, B.; Chang, S.; Lawless, J. G.

1974-01-01

An investigation was conducted concerning the possible synthesis of a suite of dicarboxylic acids similar to that found in the Murchison meteorite. The investigation included the conduction of a chemical evolution experiment which simulated electric discharge through the primitive atmosphere of the earth. The suite of dicarboxylic acids obtained in the electric discharge experiment is similar to that of the Murchison meteorite, except for the fact that 2-chlorosuccinic acid is present in the spark discharge.

Estimating sediment discharge: Appendix D

USGS Publications Warehouse

Gray, John R.; Simões, Francisco J. M.

2008-01-01

Sediment-discharge measurements usually are available on a discrete or periodic basis. However, estimates of sediment transport often are needed for unmeasured periods, such as when daily or annual sediment-discharge values are sought, or when estimates of transport rates for unmeasured or hypothetical flows are required. Selected methods for estimating suspended-sediment, bed-load, bed- material-load, and total-load discharges have been presented in some detail elsewhere in this volume. The purposes of this contribution are to present some limitations and potential pitfalls associated with obtaining and using the requisite data and equations to estimate sediment discharges and to provide guidance for selecting appropriate estimating equations. Records of sediment discharge are derived from data collected with sufficient frequency to obtain reliable estimates for the computational interval and period. Most sediment- discharge records are computed at daily or annual intervals based on periodically collected data, although some partial records represent discrete or seasonal intervals such as those for flood periods. The method used to calculate sediment- discharge records is dependent on the types and frequency of available data. Records for suspended-sediment discharge computed by methods described by Porterfield (1972) are most prevalent, in part because measurement protocols and computational techniques are well established and because suspended sediment composes the bulk of sediment dis- charges for many rivers. Discharge records for bed load, total load, or in some cases bed-material load plus wash load are less common. Reliable estimation of sediment discharges presupposes that the data on which the estimates are based are comparable and reliable. Unfortunately, data describing a selected characteristic of sediment were not necessarily derived—collected, processed, analyzed, or interpreted—in a consistent manner. For example, bed-load data collected with

A survey of ELF and VLF research on lightning-ionosphere interactions and causative discharges

NASA Astrophysics Data System (ADS)

Inan, U. S.; Cummer, S. A.; Marshall, R. A.

2010-06-01

Extremely low frequency (ELF) and very low frequency (VLF) observations have formed the cornerstone of measurement and interpretation of effects of lightning discharges on the overlying upper atmospheric regions, as well as near-Earth space. ELF (0.3-3 kHz) and VLF (3-30 kHz) wave energy released by lightning discharges is often the agent of modification of the lower ionospheric medium that results in the conductivity changes and the excitation of optical emissions that constitute transient luminous events (TLEs). In addition, the resultant ionospheric changes are best (and often uniquely) observable as perturbations of subionospherically propagating VLF signals. In fact, some of the earliest evidence for direct disturbances of the lower ionosphere in association with lightning discharges was obtained in the course of the study of such VLF perturbations. Measurements of the detailed ELF and VLF waveforms of parent lightning discharges that produce TLEs and terrestrial gamma ray flashes (TGFs) have also been very fruitful, often revealing properties of such discharges that maximize ionospheric effects, such as generation of intense electromagnetic pulses (EMPs) or removal of large quantities of charge. In this paper, we provide a review of the development of ELF and VLF measurements, both from a historical point of view and from the point of view of their relationship to optical and other observations of ionospheric effects of lightning discharges.

Partitioning Ocean Wave Spectra Obtained from Radar Observations

NASA Astrophysics Data System (ADS)

Delaye, Lauriane; Vergely, Jean-Luc; Hauser, Daniele; Guitton, Gilles; Mouche, Alexis; Tison, Celine

2016-08-01

2D wave spectra of ocean waves can be partitioned into several wave components to better characterize the scene. We present here two methods of component detection: one based on watershed algorithm and the other based on a Bayesian approach. We tested both methods on a set of simulated SWIM data, the Ku-band real aperture radar embarked on the CFOSAT (China- France Oceanography Satellite) mission which launch is planned mid-2018. We present the results and the limits of both approaches and show that Bayesian method can also be applied to other kind of wave spectra observations as those obtained with the radar KuROS, an airborne radar wave spectrometer.

Optimization of discharge circuit of the TEA CO II laser with two discharge channels

NASA Astrophysics Data System (ADS)

Hu, Xiao Yong; Zhang, LiLi; Ren, DeMing; Qu, YanChen; Zhao, WeiJiang; Song, BaoAn

2007-01-01

In order to achieve the highest peak power of radiation pulse and highest output energy, the primary circuit parameters are investigated to optimize the discharge circuit performance of the laser. The structure and the discharge circuit of the laser are discussed at first. To realize synchronous discharge in two discharge channels, the conjunct electrode device for two pairs of discharge electrodes is designed. Finally, the results of the experiments on the primary circuit parameters are given. The discharge is most stable at a pressure of 5.33×10 4Pa when the pressure of gaseous mixture CO II:N II:He=1:1:3 is changed from 2.67×10 4 Pa to 6.67×10 4 Pa. The ratio of storage capacitance to peak capacitance is chosen to be about 1.5-7/3, because residual voltage is lower on this condition and residual voltage is adverse to discharge. When the inductance 330μH is used, the homogeneous glow discharge in a widest voltage range is obtained. The duration of when the stimuli voltage is increased in homogeneous glow discharge condition. The discharge circuit allows charge and discharge and the magnitude of residual voltage decrease the homogeneous glow discharge in a wide range of pressure of gaseous mixture when these circuit parameters are used. Thus it offers reference to the improvement of output characteristic of TEA CO II laser with two discharge channels.

The Critical Role of the Routing Scheme in Simulating Peak River Discharge in Global Hydrological Models

NASA Technical Reports Server (NTRS)

Zhao, Fang; Veldkamp, Ted I. E.; Frieler, Katja; Schewe, Jacob; Ostberg, Sebastian; Willner, Sven; Schauberger, Bernhard; Gosling, Simon N.; Schmied, Hannes Muller; Portmann, Felix T.;

Validation of Observations Obtained with a Liquid Mirror Telescope by Comparison with Sloan Digital Sky Survey Observations

NASA Astrophysics Data System (ADS)

Borra, E. F.

2015-06-01

The results of a search for peculiar astronomical objects using very low resolution spectra obtained with the NASA Orbital Debris Observatory (NODO) 3 m diameter liquid mirror telescope (LMT) are compared with results of spectra obtained with the Sloan Digital Sky Survey (SDSS). The main purpose of this comparison is to verify whether observations taken with this novel type of telescope are reliable. This comparison is important because LMTs are an inexpensive novel type of telescope that is very useful for astronomical surveys, particularly surveys in the time domain, and validation of the data taken with an LMT by comparison with data from a classical telescope will validate their reliability. We start from a published data analysis that classified as peculiar only 206 of the 18,000 astronomical objects observed with the NODO LMT. A total of 29 of these 206 objects were found in the SDSS. The reliability of the NODO data can be seen through the results of the detailed analysis that, in practice, incorrectly identified less than 0.3% of the 18,000 spectra as peculiar objects, most likely because they are variable stars. We conclude that the LMT gave reliable observations, comparable to those that would have been obtained with a telescope using a glass mirror.

Dissemination of satellite-based river discharge and flood data

NASA Astrophysics Data System (ADS)

Kettner, A. J.; Brakenridge, G. R.; van Praag, E.; de Groeve, T.; Slayback, D. A.; Cohen, S.

2014-12-01

In collaboration with NASA Goddard Spaceflight Center and the European Commission Joint Research Centre, the Dartmouth Flood Observatory (DFO) daily measures and distributes: 1) river discharges, and 2) near real-time flood extents with a global coverage. Satellite-based passive microwave sensors and hydrological modeling are utilized to establish 'remote-sensing based discharge stations', and observed time series cover 1998 to the present. The advantages over in-situ gauged discharges are: a) easy access to remote or due to political reasons isolated locations, b) relatively low maintenance costs to maintain a continuous observational record, and c) the capability to obtain measurements during floods, hazardous conditions that often impair or destroy in-situ stations. Two MODIS instruments aboard the NASA Terra and Aqua satellites provide global flood extent coverage at a spatial resolution of 250m. Cloud cover hampers flood extent detection; therefore we ingest 6 images (the Terra and Aqua images of each day, for three days), in combination with a cloud shadow filter, to provide daily global flood extent updates. The Flood Observatory has always made it a high priority to visualize and share its data and products through its website. Recent collaborative efforts with e.g. GeoSUR have enhanced accessibility of DFO data. A web map service has been implemented to automatically disseminate geo-referenced flood extent products into client-side GIS software. For example, for Latin America and the Caribbean region, the GeoSUR portal now displays current flood extent maps, which can be integrated and visualized with other relevant geographical data. Furthermore, the flood state of satellite-observed river discharge sites are displayed through the portal as well. Additional efforts include implementing Open Geospatial Consortium (OGC) standards to incorporate Water Markup Language (WaterML) data exchange mechanisms to further facilitate the distribution of the satellite

Observations of Blue Discharges Associated With Negative Narrow Bipolar Events in Active Deep Convection

NASA Astrophysics Data System (ADS)

Liu, Feifan; Zhu, Baoyou; Lu, Gaopeng; Qin, Zilong; Lei, Jiuhou; Peng, Kang-Ming; Chen, Alfred B.; Huang, Anjing; Cummer, Steven A.; Chen, Mingli; Ma, Ming; Lyu, Fanchao; Zhou, Helin

2018-03-01

On 19 August 2012, the Imager of Sprites and Upper Atmospheric Lightning on board the FORMOSAT-2 satellite captured a sequence of seven blue discharges within 1 min that emanated from a parent thunderstorm over Lake Taihu in East China. The analysis of lightning activity produced in the thunderstorm indicates that at least six of these events occurred in association with negative narrow bipolar events (NBEs) that were concurrent with the blue discharge by less than 1 ms, and negative cloud-to-ground occurred within 6 s before each blue discharge, which is in agreement with the modeling presented by Krehbiel et al. (2008). Therefore, the frequent occurrence of negative cloud-to-ground could provide the favorable condition for the production of blue discharges, and negative NBEs are probably the initial event of blue discharges. The detection of negative NBEs might provide a convenient approach to detect the occurrence of blue discharges as lightning bolt shooting upward from the top of energetic thunderstorms.

The critical role of the routing scheme in simulating peak river discharge in global hydrological models

NASA Astrophysics Data System (ADS)

Zhao, F.; Veldkamp, T.; Frieler, K.; Schewe, J.; Ostberg, S.; Willner, S. N.; Schauberger, B.; Gosling, S.; Mueller Schmied, H.; Portmann, F. T.; Leng, G.; Huang, M.; Liu, X.; Tang, Q.; Hanasaki, N.; Biemans, H.; Gerten, D.; Satoh, Y.; Pokhrel, Y. N.; Stacke, T.; Ciais, P.; Chang, J.; Ducharne, A.; Guimberteau, M.; Wada, Y.; Kim, H.; Yamazaki, D.

2017-12-01

Global hydrological models (GHMs) have been applied to assess global flood hazards, but their capacity to capture the timing and amplitude of peak river discharge—which is crucial in flood simulations—has traditionally not been the focus of examination. Here we evaluate to what degree the choice of river routing scheme affects simulations of peak discharge and may help to provide better agreement with observations. To this end we use runoff and discharge simulations of nine GHMs forced by observational climate data (1971-2010) within the ISIMIP2a project. The runoff simulations were used as input for the global river routing model CaMa-Flood. The simulated daily discharge was compared to the discharge generated by each GHM using its native river routing scheme. For each GHM both versions of simulated discharge were compared to monthly and daily discharge observations from 1701 GRDC stations as a benchmark. CaMa-Flood routing shows a general reduction of peak river discharge and a delay of about two to three weeks in its occurrence, likely induced by the buffering capacity of floodplain reservoirs. For a majority of river basins, discharge produced by CaMa-Flood resulted in a better agreement with observations. In particular, maximum daily discharge was adjusted, with a multi-model averaged reduction in bias over about 2/3 of the analysed basin area. The increase in agreement was obtained in both managed and near-natural basins. Overall, this study demonstrates the importance of routing scheme choice in peak discharge simulation, where CaMa-Flood routing accounts for floodplain storage and backwater effects that are not represented in most GHMs. Our study provides important hints that an explicit parameterisation of these processes may be essential in future impact studies.

Stage-discharge rating curves based on satellite altimetry and modeled discharge in the Amazon basin

NASA Astrophysics Data System (ADS)

Paris, Adrien; Dias de Paiva, Rodrigo; Santos da Silva, Joecila; Medeiros Moreira, Daniel; Calmant, Stephane; Garambois, Pierre-André; Collischonn, Walter; Bonnet, Marie-Paule; Seyler, Frederique

2016-05-01

In this study, rating curves (RCs) were determined by applying satellite altimetry to a poorly gauged basin. This study demonstrates the synergistic application of remote sensing and watershed modeling to capture the dynamics and quantity of flow in the Amazon River Basin, respectively. Three major advancements for estimating basin-scale patterns in river discharge are described. The first advancement is the preservation of the hydrological meanings of the parameters expressed by Manning's equation to obtain a data set containing the elevations of the river beds throughout the basin. The second advancement is the provision of parameter uncertainties and, therefore, the uncertainties in the rated discharge. The third advancement concerns estimating the discharge while considering backwater effects. We analyzed the Amazon Basin using nearly one thousand series that were obtained from ENVISAT and Jason-2 altimetry for more than 100 tributaries. Discharge values and related uncertainties were obtained from the rain-discharge MGB-IPH model. We used a global optimization algorithm based on the Monte Carlo Markov Chain and Bayesian framework to determine the rating curves. The data were randomly allocated into 80% calibration and 20% validation subsets. A comparison with the validation samples produced a Nash-Sutcliffe efficiency (Ens) of 0.68. When the MGB discharge uncertainties were less than 5%, the Ens value increased to 0.81 (mean). A comparison with the in situ discharge resulted in an Ens value of 0.71 for the validation samples (and 0.77 for calibration). The Ens values at the mouths of the rivers that experienced backwater effects significantly improved when the mean monthly slope was included in the RC. Our RCs were not mission-dependent, and the Ens value was preserved when applying ENVISAT rating curves to Jason-2 altimetry at crossovers. The cease-to-flow parameter of our RCs provided a good proxy for determining river bed elevation. This proxy was validated

Particle-in-cell simulations of anomalous transport in a Penning discharge

NASA Astrophysics Data System (ADS)

Carlsson, Johan; Kaganovich, Igor; Powis, Andrew; Raitses, Yevgeny; Romadanov, Ivan; Smolyakov, Andrei

2018-06-01

Electrostatic particle-in-cell simulations of a Penning discharge are performed in order to investigate azimuthally asymmetric, spoke-like structures previously observed in experiments. Two-dimensional simulations show that for Penning-discharge conditions, a persistent nonlinear spoke-like structure forms readily and rotates in the direction of E × B and electron diamagnetic drifts. The azimuthal velocity is within about a factor of 2 of the ion acoustic speed. The spoke frequency follows the experimentally observed scaling with ion mass, which indicates the importance of ion inertia in spoke formation. The spoke provides enhanced (anomalous) radial electron transport, and the effective cross-field conductivity is several times larger than the classical (collisional) value. The level of anomalous current obtained in the simulations is in good agreement with the experimental data. The rotating spoke channels most of the radial current, observable by an edge probe as short pulses.

Study of ultrasound-assisted radio-frequency plasma discharges in n-dodecane

NASA Astrophysics Data System (ADS)

Camerotto, Elisabeth; De Schepper, Peter; Nikiforov, Anton Y.; Brems, Steven; Shamiryan, Denis; Boullart, Werner; Leys, Christophe; De Gendt, Stefan

2012-10-01

This paper investigates the generation of a stable plasma phase in a liquid hydrocarbon (n-dodecane) by means of ultrasound (US) and radio-frequency (RF) or electromagnetic radiation. It is demonstrated for the first time that ultrasonic aided RF plasma discharges can be generated in a liquid. Plasma discharges are obtained for different gas mixtures at a pressure of 12 kPa and at low ignition powers (100 W for RF and 2.4 W cm-2 for US). Direct carbon deposition from the liquid precursor on Cu, Ni, SiO2 and Si substrates has been obtained and no apparent compositional or structural difference among the substrate materials was observed. Characterization of the deposited solid phase revealed an amorphous structure. In addition, structural changes in the liquid precursor after plasma treatment have been analysed. Optical emission spectroscopy (OES) allowed the estimation of several plasma characteristic temperatures. The plasma excitation temperature was estimated to be about 2.3-2.4 eV. The rotational and vibrational temperatures of the discharge in n-dodecane with Ar as a feed gas were 1400 K and 6500 K, respectively. In Ar/O2 plasma, an increased rotational (1630 K) and vibrational temperature (7200 K) were obtained.

Simulation of spring discharge from a limestone aquifer in Iowa, USA

USGS Publications Warehouse

Zhang, Y.-K.; Bai, E.-W.; Libra, R.; Rowden, R.; Liu, H.

1996-01-01

A lumped-parameter model and least-squares method were used to simulate temporal variations of discharge from Big Spring, Iowa, USA, from 1983 to 1994. The simulated discharge rates poorly match the observed one when precipitation is taken as the sole input. The match is improved significantly when the processes of evapotranspiration and infiltration are considered. The best results are obtained when snowmelt is also included in the model. Potential evapotranspiration was estimated with Thornthwaite's formula, infiltration was calculated through a water-balance approach, and snowmelt was generated by a degree-day model. The results show that groundwater in the limestone aquifer is mainly recharged by snowmelt in early spring and by infiltration from rainfall in later spring and early summer. Simulated discharge was visually calibrated against measured discharge; the similarity between the two supports the validity of this approach. The model can be used to study the effects of climate change on groundwater resources and their quality.

Incident CTS in a large pooled cohort study: associations obtained by a Job Exposure Matrix versus associations obtained from observed exposures.

PubMed

Dale, Ann Marie; Ekenga, Christine C; Buckner-Petty, Skye; Merlino, Linda; Thiese, Matthew S; Bao, Stephen; Meyers, Alysha Rose; Harris-Adamson, Carisa; Kapellusch, Jay; Eisen, Ellen A; Gerr, Fred; Hegmann, Kurt T; Silverstein, Barbara; Garg, Arun; Rempel, David; Zeringue, Angelique; Evanoff, Bradley A

2018-03-29

There is growing use of a job exposure matrix (JEM) to provide exposure estimates in studies of work-related musculoskeletal disorders; few studies have examined the validity of such estimates, nor did compare associations obtained with a JEM with those obtained using other exposures. This study estimated upper extremity exposures using a JEM derived from a publicly available data set (Occupational Network, O*NET), and compared exposure-disease associations for incident carpal tunnel syndrome (CTS) with those obtained using observed physical exposure measures in a large prospective study. 2393 workers from several industries were followed for up to 2.8 years (5.5 person-years). Standard Occupational Classification (SOC) codes were assigned to the job at enrolment. SOC codes linked to physical exposures for forceful hand exertion and repetitive activities were extracted from O*NET. We used multivariable Cox proportional hazards regression models to describe exposure-disease associations for incident CTS for individually observed physical exposures and JEM exposures from O*NET. Both exposure methods found associations between incident CTS and exposures of force and repetition, with evidence of dose-response. Observed associations were similar across the two methods, with somewhat wider CIs for HRs calculated using the JEM method. Exposures estimated using a JEM provided similar exposure-disease associations for CTS when compared with associations obtained using the 'gold standard' method of individual observation. While JEMs have a number of limitations, in some studies they can provide useful exposure estimates in the absence of individual-level observed exposures. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

SOME NEW DATA ON SELF-COMPRESSED DISCHARGES (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kvartskhava, I.F.; Kervalidze, K.N.; Gvaladze, Yu.C.

1962-01-01

The theory of self-constricted discharges, which predicts the possibiiity of the appearance of various types of instabilities, does not reflect fully the multiple phenoniena which are experimentally observed. The models used in the theory evidentiy do not consider the presence of some processes in self- constricted discharges which materially determine the real behavior of the plasma. The experiments showed a number of such processes. Basically, they consist of an unequal heating of the discharge near the walls of the chamber. Thereby the discharge currents fiow along distorted threadlike channels which, in theta - pinches mostly follow either the z-direction ormore » the theta -direction, and in z- pinches they basically follow the theta -direction. In the process of plasma compression the above mentioned thread formations experience unequal accelerations. Having a high conductivity, these formations facilitate the capture of magnetic fieids which obstructs the thermaiization of the kinetic energy of the plasma's radial motion. As a result of this process the plasma is far from thermial equilibrium when in the stage of maximum compression. It is encompassed by a motion of turbulent character. After the maximum compression of the plasma, various kinds of plasma formation are ejected from the surface of the pinch. The magnetic field is more effectively trapped than in zpinches. Consequently, a greater variety of types of instability is observed in theta - pinches than in z-pinches. Highspeed photography of the discharge turned out to be the most practical and fruitful method of studying the processes of formation and the subsequent motion of the plasma. Photographs of the discharges obtained by streak photography and by framing camera are discussed. The results of probe measurements of magnetic and electric fields as well as the results of measurements of currents by means of Rogovsky belts are given. (auth)« less

Discharge current distribution in stratified soil under impulse discharge

NASA Astrophysics Data System (ADS)

Eniola Fajingbesi, Fawwaz; Shahida Midi, Nur; Elsheikh, Elsheikh M. A.; Hajar Yusoff, Siti

2017-06-01

The mobility of charge particles traversing a material defines its electrical properties. Soil (earth) have long been the universal grounding before and after the inception of active ground systems for electrical appliance purpose due to it semi-conductive properties. The soil can thus be modelled as a single material exhibiting semi-complex inductive-reactive impedance. Under impulse discharge such as lightning strikes to soil this property of soil could result in electric potential level fluctuation ranging from ground potential rise/fall to electromagnetic pulse coupling that could ultimately fail connected electrical appliance. In this work we have experimentally model the soil and lightning discharge using point to plane electrode setup to observe the current distribution characteristics at different soil conductivity [mS/m] range. The result presented from this research indicate above 5% shift in conductivity before and after discharge which is significant for consideration when dealing with grounding designs. The current distribution in soil have also be successfully observed and analysed from experimental result using mean current magnitude in relation to electrode distance and location, current density variation with depth all showing strong correlation with theoretical assumptions of a semi-complex impedance material.

Influence of driving frequency on discharge modes in the dielectric barrier discharge excited by a triangle voltage

NASA Astrophysics Data System (ADS)

Li, Xuechen; Liu, Rui; Jia, Pengying; Wu, Kaiyue; Ren, Chenhua; Yin, Zengqian

2018-01-01

A one-dimensional fluid model in atmospheric pressure argon is employed to investigate the influence of the driving frequency on dielectric barrier discharge modes excited by a triangle voltage. Results indicate that a stepped discharge mode is obtained with a low driving frequency of 35 kHz. The current amplitude increases, while its plateau duration decreases with increasing the frequency. The stepped discharge transits into a multi-pulsed mode when the frequency is increased to 80 kHz. With its further increment, the pulse number decreases, and a double-pulsed discharge is realized at 90 kHz, which finally transits to a single-pulsed discharge. Through analyzing spatial distributions of electron density, ion density, and electric field, it can be concluded that the discharge regime transits from a Townsend-like discharge to a glow discharge with increasing the frequency. The regime transition is further verified by analyzing voltage-current curves. These simulated results are consistent with the experimental phenomena.

Clinical observation, pharmacotherapy and referral on discharge of patients with anxiety disorder in a psychiatric emergency service.

PubMed

Pailhez, Guillem; Majó, Albert; Córcoles, David; Ginés, José M; Arcega, José M; Castaño, Juan; Merino, Ana; Bulbena, Antonio; Pérez, Víctor

2015-01-01

To analyze factors associated with clinical observation, pharmacotherapy and referral on discharge of patients with anxiety disorder (AD) seeking care at a psychiatric emergency unit. A total of 5003 consecutive visits were reviewed over a three-year period at a psychiatric emergency service in a tertiary university hospital. Data collected included sociodemographic and clinical information as well as the Global Assessment of Functioning (GAF) and the Severity Psychiatric Illness (SPI) scale scores. Of all the visits, 992 (19.8%) were diagnosed of AD. Of these, 19.6% required clinical observation and 72.2% were referred to a psychiatrist at discharge. Regression analysis showed that referral to psychiatry was associated with being male, native, psychiatric background, greater severity, lower global functioning, and behavioral disorders. Clinical observation (in a box) was associated with being female, greater severity, and psychotic or behavioral symptoms. Prescription of benzodiazepines was associated with anxiety, no history of addiction, and lower global functioning. Antidepressants were associated with being a native, anxiety with no history of addiction, and lower functioning. Antipsychotics were associated with being native, psychiatric background (not addiction), anxiety, and lower functioning. Behavior, psychiatric background and illness severity were determinants of referral to a specialist. Besides these, psychotic symptoms and non-specific clinical symptoms were determinants of observation. Drug prescription in AD is less frequent if the main complaint is not anxiety and depends more on the level of functioning than on that of severity.

Motor unit potential induced repetitive discharges (MIRDs): description of an unusual iterative discharge.

PubMed

So, Noel F; Rubin, Devon I; Jones, Lyell K; Litchy, William J; Sorenson, Eric J

2013-12-01

Repetitive discharges may be recorded during nerve conduction studies (NCS) or during needle electromyography in a muscle at rest. Repetitive discharges that occur during voluntary activation and are time-locked to voluntary motor unit potentials (MUP) have not been described. Retrospective review of motor unit potential induced repetitive discharges (MIRDs) identified in the EMG laboratory. Characteristics of each MIRD, patient demographics, other EMG findings in the same muscle, and electrophysiological diagnosis were analyzed. MIRDs were observed in 15 patients. The morphology and number of spikes and duration of MIRDs varied. The discharges fired at rates of 50-200 Hz. All but 2 patients had EMG findings of a chronic neurogenic disorder. MIRDs are rare iterative discharges time-locked to a voluntary MUP. The pathophysiology of MIRDs is unclear, but their presence may indicate a chronic neurogenic process. Copyright © 2013 Wiley Periodicals, Inc.

Correlated Lightning Mapping Array (LMA) and Radar Observations of the Initial Stages of Florida Triggered Lightning Discharges

NASA Technical Reports Server (NTRS)

Hill, J. D.; Pilkey, J.; Uman, M, A.; Jordan, D. M.; Biggerstaff, M. I.; Rison, W.; Blakeslee, R.

2012-01-01

We characterize the geometrical and electrical characteristics of the initial stages of nine Florida triggered lightning discharges using a Lightning Mapping Array (LMA), a C-band SMART radar, and measured channel-base currents. We determine initial channel and subsequent branch lengths, average initial channel and branch propagation speeds, and channel-base current at the time of each branch initiation. The channel-base current is found to not change significantly when branching occurs, an unexpected result. The initial stage of Florida triggered lightning typically transitions from vertical to horizontal propagation at altitudes of 3-6 km, near the typical 0 C level of 4-5 km and several kilometers below the expected center of the negative cloud-charge region at 7-8 km. The data presented potentially provide information on thunderstorm electrical and hydrometeor structure and discharge propagation physics. LMA source locations were obtained from VHF sources of positive impulsive currents as small as 10 A, in contrast to expectations found in the literature.

Magnetic dipole discharges. II. Cathode and anode spot discharges and probe diagnostics

NASA Astrophysics Data System (ADS)

Stenzel, R. L.; Urrutia, J. M.; Ionita, C.; Schrittwieser, R.

2013-08-01

The high current regime of a magnetron-type discharge has been investigated. The discharge uses a permanent magnet as a cold cathode which emits secondary electrons while the chamber wall or a grounded electrode serves as the anode. As the discharge voltage is increased, the magnet develops cathode spots, which are short duration arcs that provide copious electrons to increase the discharge current dramatically. Short (1 μs), high current (200 A) and high voltage (750 V) discharge pulses are produced in a relaxation instability between the plasma and a charging capacitor. Spots are also observed on a negatively biased plane Langmuir probe. The probe current pulses are as large as those on the magnet, implying that the high discharge current does not depend on the cathode surface area but on the properties of the spots. The fast current pulses produce large inductive voltages, which can reverse the electrical polarity of the magnet and temporarily operate it as an anode. The discharge current may also oscillate at the frequency determined by the charging capacitor and the discharge circuit inductance. Each half cycle of high-current current pulses exhibits a fast (≃10 ns) current rise when a spot is formed. It induces high frequency (10-100 MHz) transients and ringing oscillations in probes and current circuits. Most probes behave like unmatched antennas for the electromagnetic pulses of spot discharges. Examples are shown to distinguish the source of oscillations and some rf characteristics of Langmuir probes.

The discharge characteristics in nitrogen helicon plasma

NASA Astrophysics Data System (ADS)

Zhao, Gao; Wang, Huihui; Si, Xinlu; Ouyang, Jiting; Chen, Qiang; Tan, Chang

2017-12-01

Discharge characteristics of helicon plasma in nitrogen and argon-nitrogen mixtures were investigated experimentally by using a Langmuir probe, a B-dot probe, and an optical emission spectrum. Helicon wave discharge is confirmed by the changes of electron density and electromagnetic signal amplitude with the increasing RF power, which shows three discharge stages in nitrogen, corresponding to E-mode, H-mode, and W-mode discharges in helicon plasma, respectively. Discharge images in the radial cross section at different discharge modes through an intensified charge coupled device (ICCD) show a rapid increase in luminous intensity along with the RF power. When the nitrogen discharge is in the W-mode, the images show that the strongest luminance locates near the plasma boundary and no blue core appears in the axial center of tube, which is always observed in argon W-mode discharge. The "big blue" or blue core is a special character in helicon plasma, but it has not been observed in nitrogen helicon plasma. In nitrogen-argon mixtures, a weak blue core is observed in ICCD images since the nitrogen content is increased. The electric field turns to the periphery in the distribution of the radial field and the electron temperature decreases with the increasing nitrogen content, especially when the blue core disappears. The different behaviors of the electron impact and the energy consumption in nitrogen helicon plasma are suggested to be responsible for the decrease in electron energy and the change in the electric field distribution.

Investigation of airflow effects on the dielectric barrier discharge with single/double discharge channel arrangement

NASA Astrophysics Data System (ADS)

Fan, Zhihui; Yan, Huijie; Liu, Yidi; Guo, Hongfei; Wang, Yuying; Ren, Chunsheng

2018-05-01

Atmospheric-pressure dielectric barrier discharge (DBD) with airflow participation has been widely used in recent years. In this paper, effects of airflow on DBD characteristics are experimentally investigated by single/double pin-to-plate DBD arrangements with an AC exciting source. The discharge electrical characteristics and the movements of discharge channels in airflow are investigated with a single pin electrode arrangement. The current intensities increase in positive cycles and decrease in negative cycles with the increase in airflow velocity. The transition from a filamentary discharge to a diffuse discharge is observed under certain airflow conditions, and the discharge channels move with the airflow with a movement velocity less than the corresponding airflow velocity. In the cases of double pin electrode arrangements, the repulsion between double pin discharge channels is apparent at a 10 mm distance but is not obvious at a 20 mm distance. When the airflow is introduced into the discharge gap, not as in the case of single pin electrode arrangement, the movements of discharge channels in airflow are affected by adjacent discharge channels. The corresponding reasons are analyzed in the paper.

KrF laser pumping by electron beam discharge

NASA Astrophysics Data System (ADS)

Bonnet, J.; Fournier, G.; Pigache, D.

1981-09-01

The pumping of excimer lasers used in nuclear fusion and isotope separation is considered. Homogeneous ionization with an electron beam permitted discharge pumping of a KrF laser with a discharge-energy/beam-energy ratio 5. This high value is obtained to the detriment of an energy density and an efficiency which are about half the best values obtained under other conditions. This result does not modify a recent conclusion indicating that an electron beam controlled discharge has no significant advantage over a pure electron beam as regards pumping high energy KrF lasers at high repetition rate.

Parametric investigation of enclosed keeper discharge characteristics

NASA Technical Reports Server (NTRS)

Sheheen, T. W.; Finke, R. C.

1973-01-01

Volt-ampere discharge characteristics of an enclosed keeper hollow cathode discharge were measured as a function of the mercury flow rate and external circuit impedance. Discharge currents were varied from 0 to 1 ampere and voltages were 7 to 39 volts. Batteries and a vacuum tube control circuit were used to obtain characteristics curves that were independent of power supply impedance. Variation of the neutral flow results in changes in the discharge which interact with the impedance of the external circuit, and under some conditions, give rise to multiple operating points.

High-repetition-rate short-pulse gas discharge.

PubMed

Tulip, J; Seguin, H; Mace, P N

1979-09-01

A high-average-power short-pulse gas discharge is described. This consists of a volume-preionized transverse discharge of the type used in gas lasers driven by a Blumlein energy storage circuit. The Blumlein circuit is fabricated from coaxial cable, is pulse-charged from a high-repetition-rate Marx-bank generator, and is switched by a high-repetition-rate segmented rail gap. The operation of this discharge under conditions typical of rare-gas halide lasers is described. A maximum of 900 pps was obtained, giving a power flow into the discharge of 30 kW.

Observation of a periodic runaway in the reactive Ar/O{sub 2} high power impulse magnetron sputtering discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shayestehaminzadeh, Seyedmohammad, E-mail: ses30@hi.is, E-mail: shayesteh@mch.rwth-aachen.de; Arnalds, Unnar B.; Magnusson, Rögnvaldur L.

2015-11-15

This paper reports the observation of a periodic runaway of plasma to a higher density for the reactive discharge of the target material (Ti) with moderate sputter yield. Variable emission of secondary electrons, for the alternating transition of the target from metal mode to oxide mode, is understood to be the main reason for the runaway occurring periodically. Increasing the pulsing frequency can bring the target back to a metal (or suboxide) mode, and eliminate the periodic transition of the target. Therefore, a pulsing frequency interval is defined for the reactive Ar/O{sub 2} discharge in order to sustain the plasmamore » in a runaway-free mode without exceeding the maximum power that the magnetron can tolerate.« less

Medication issues experienced by patients and carers after discharge from the intensive care unit.

PubMed

Eijsbroek, Heleen; Howell, David C J; Smith, Felicity; Shulman, Rob

2013-02-01

Medication-related problems (MRPs) frequently occur at the interfaces of care settings. We examined this further because little has been published about MRPs experienced by patients/carers after discharge from the intensive care unit (ICU). Medication history data were collected before, during, and after ICU admission and by face-to-face semistructured interviews with 21 patients and 13 carers attending the ICU Follow-up Clinic (FC) of our 35-bed adult ICU. A total of 122 drugs were prescribed regularly before ICU admission, 168 on ICU discharge, 132 at hospital discharge, and 128 at the FC. Medication-related problems were identified with hypnotics/anxiolytics, antidepressants, proton pump inhibitors, and analgesics. Good follow-up was observed in all 4 cases where the antidysrhythmic agent amiodarone was initiated on ICU. Patients/carers described 20 cases of difficulty in obtaining appropriate and timely supplies and 19 of insufficient information. These results show that our incidence of MRPs after ICU discharge was encouragingly infrequent, in which we attribute it to targeted medicine reconciliation and the availability of our FC. However, MRPs were perceived to stem from inadequate communication at the interfaces of care and the lack of opportunity for patients/carers to obtain relevant information. We recommend that FC should focus on MRPs during their consultation and that further research in this area should be performed to examine our observations further. Copyright © 2013 Elsevier Inc. All rights reserved.

Triggering Excimer Lasers by Photoionization from Corona Discharges

NASA Astrophysics Data System (ADS)

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

2009-10-01

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

Discharge Characteristics of Series Surface/Packed-Bed Discharge Reactor Diven by Bipolar Pulsed Power

NASA Astrophysics Data System (ADS)

Hu, Jian; Jiang, Nan; Li, Jie; Shang, Kefeng; Lu, Na; Wu, Yan; Mizuno, Akira

2016-03-01

The discharge characteristics of the series surface/packed-bed discharge (SSPBD) reactor driven by bipolar pulse power were systemically investigated in this study. In order to evaluate the advantages of the SSPBD reactor, it was compared with traditional surface discharge (SD) reactor and packed-bed discharge (PBD) reactor in terms of the discharge voltage, discharge current, and ozone formation. The SSPBD reactor exhibited a faster rising time and lower tail voltage than the SD and PBD reactors. The distribution of the active species generated in different discharge regions of the SSPBD reactor was analyzed by optical emission spectra and ozone analysis. It was found that the packed-bed discharge region (3.5 mg/L), rather than the surface discharge region (1.3 mg/L) in the SSPBD reactor played a more important role in ozone generation. The optical emission spectroscopy analysis indicated that more intense peaks of the active species (e.g. N2 and OI) in the optical emission spectra were observed in the packed-bed region. supported by National Natural Science Foundation of China (No. 51177007), the Joint Funds of National Natural Science Foundation of China (No. U1462105), and Dalian University of Technology Fundamental Research Fund of China (No. DUT15RC(3)030)

DC corona discharge ozone production enhanced by magnetic field

NASA Astrophysics Data System (ADS)

Pekárek, S.

2010-01-01

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

Postoperative rehabilitation for chronic subdural hematoma in the elderly. An observational study focusing on balance, ambulation and discharge destination.

PubMed

Carlisi, Ettore; Feltroni, Lucia; Tinelli, Carmine; Verlotta, Mariarosaria; Gaetani, Paolo; Dalla Toffola, Elena

2017-02-01

Chronic subdural hematoma (CSDH) can have a negative impact on autonomy of the elderly. Ambulatory and functional status may remain limited despite successful surgical evacuation. To evaluate the outcome of a postoperative assisted rehabilitation program. Single-institution short-term observational study. Inpatient (Neurosurgery Unit of a University Hospital). Thirty-five patients, aged 65 or older, who underwent burr-hole drainage for chronic subdural hematoma. Postoperatively all participants underwent a rehabilitation program, described in details, aimed at recovering standing position and gait as soon as possible. The program involved daily 30-minute individual sessions assisted by a physiotherapist, until discharge from hospital. The Markwalder's Grading Scale was used to assess the neurological status preoperatively and at discharge. The Trunk Control Test, the Standing Balance by Bohannon Scale and the Modified Rankin Scale were used to evaluate balance and general function (primary outcome) in the immediate postoperative and at discharge. We also recorded the rate of pre-CSDH walking patients who maintained ambulation at discharge and the discharge destination (secondary outcome). Total scores of Markwalder's Grading Scale, Trunk Control Test, Standing Balance by Bohannon Scale and Modified Rankin Scale improved (P<0.05), indicating a global favorable outcome, especially for balance. Excluding the patients who were dependent pre-CSDH, the others maintained gait function in 74.2% of cases. Only 45.7% of the patients were discharged home, the others being divided between inpatient medical settings and rehabilitation. The rehabilitation program was well tolerated by the patients. Our study showed a clear improvement in trunk control and standing balance and an overall favorable outcome for neurological and ambulatory status at discharge. Despite an assisted postoperative rehabilitation program, the residual impairment in general function was the main factor

Flow determination of a pump-turbine at zero discharge

NASA Astrophysics Data System (ADS)

Edinger, G.; Erne, S.; Doujak, E.; Bauer, C.

2014-03-01

When starting up a reversible Francis pump-turbine in pump mode, the machine may operate at zero flow at a given gate opening. Besides reversal flow and prerotation in the draft tube cone, the onset of a fully separated flow in the vaned diffuser is observable at zero- discharge condition. In this paper, the occurrence of prerotation and reversal flow in the conical draft tube and the flow in one stay vane channel of a pump-turbine are examined experimentally and compared to numerical simulations. In order to assess the strongly three-dimensional flow in the stay vane channel, measurements with a 2D laser doppler velocimeter (LDV) were performed at various positions. The inlet flow in the draft tube cone, which becomes significantly at zero discharge in pump mode, is investigated by velocity measurements at two different positions. Pressure fluctuations in the draft tube cone induced by complex flow patterns are also recorded and analyzed. It is found that the swirl number at zero discharge does not significant differ from the values obtained at very low load pumping. Experimental investigations combined with CFD have shown that in the stay vane channel flow velocity components different from zero occur even at no discharge. Streamline plots show the fully separated flow structure.

Numerical Modeling of the Hall Thruster Discharge

DTIC Science & Technology

2005-04-01

This collection of seven previously published papers performed under Grant No. FA8655-04-1-3003 provide the background for the development of a new version of the HPHall hybrid code (HPHallv.2) for the numerical modeling of Hall Thruster discharge and new insights on discharge physics obtained during the development.

Time resolved EUV spectra from Zpinching capillary discharge plasma

NASA Astrophysics Data System (ADS)

Jancarek, Alexandr; Nevrkla, Michal; Nawaz, Fahad

2015-09-01

We developed symmetrically charged driver to obtain high voltage, high current Z-pinching capillary discharge. Plasma is created by up to 70 kA, 29 ns risetime current pulse passing through a 5 mm inner diameter, 224 mm long capillary filled with gas to initial pressure in the range of 1 kPa. Due to the low inductance design of the driver, the pinch is observable directly from the measured current curve. Time-integrated and time-resolved spectra of discharge plasma radiation are recorded together with the capillary current and analyzed. The most encouraging spectra were captured in the wavelength range 8.3 ÷ 14 nm. This spectral region contains nitrogen Balmer series lines including potentially lasing NVII 2 - 3 transition. Spectral lines are identified in the NIST database using the FLY kinetic code. The line of 13.38 nm wavelength, transition NVII 2 - 3, was observed in gated, and also in time-integrated spectra for currents >60 kA. This work has been supported by the Ministry of Education, Youth and Sports of the Czech Republic grants LG13029.

Static current-voltage characteristics for radio-frequency induction discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Budyansky, A.; Zykov, A.

1995-12-31

The aim of this work was to obtain experimentally such characteristic of Radio-Frequency Induction Discharge (RFID) that can play the role of its current-voltage characteristic (CVC) and to explain the nature of current and voltage jumps arising in RF coils at exciting of discharge. Experiments were made in quartz 5.5, 11, 20 cm diam tubes with outer RF coil at pressures 10--100 mTorr, at frequency 13.56 MHz and discharge power to 500 W. In case of outer coil as analogue of discharge voltage it`s convenient to use the value of the RF voltage U{sub R}, induced around outer perimeter ofmore » discharge tube. It is evident that current and voltage jumps arising at exciting of discharge are due to low output resistance of standard generators and negative slope of initial part of CVC. Three sets of such dependencies for different pressures were obtained for each diameter of tubes. The influence of different metal electrodes placed into discharge volume on CVC`s shape has been studied also. Experimental results can explain the behavior of HFI discharge as a load of RF generator and give data for calculation of RF circuit.« less

Observability of global rivers with future SWOT observations

NASA Astrophysics Data System (ADS)

Fisher, Colby; Pan, Ming; Wood, Eric

2017-04-01

The Surface Water and Ocean Topography (SWOT) mission is designed to provide global observations of water surface elevation and slope from which river discharge can be estimated using a data assimilation system. This mission will provide increased spatial and temporal coverage compared to current altimeters, with an expected accuracy for water level elevations of 10 cm on rivers greater than 100 m wide. Within the 21-day repeat cycle, a river reach will be observed 2-4 times on average. Due to the relationship between the basin orientation and the orbit, these observations are not evenly distributed in time, which will impact the derived discharge values. There is, then, a need for a better understanding of how the mission will observe global river basins. In this study, we investigate how SWOT will observe global river basins and how the temporal and spatial sampling impacts the discharge estimated from assimilation. SWOT observations can be assimilated using the Inverse Streamflow Routing (ISR) model of Pan and Wood [2013] with a fixed interval Kalman smoother. Previous work has shown that the ISR assimilation method can be used to reproduce the spatial and temporal dynamics of discharge within many global basins: however, this performance was strongly impacted by the spatial and temporal availability of discharge observations. In this study, we apply the ISR method to 32 global basins with different geometries and crossing patterns for the future orbit, assimilating theoretical SWOT-retrieved "gauges". Results show that the model performance varies significantly across basins and is driven by the orientation, flow distance, and travel time in each. Based on these properties, we quantify the "observability" of each basin and relate this to the performance of the assimilation. Applying this metric globally to a large variety of basins we can gain a better understanding of the impact that SWOT observations may have across basin scales. By determining the

[Spectral diagnosis of hydroxyl radical in multiphase pulsed discharge system].

PubMed

Wang, Hui-juan; Li, Jie; Quan, Xie; Wu, Yan; Li, Guo-feng

2007-12-01

A gas-liquid hybrid pulsed discharge system with a multi-needle-to-plate electrode geometry was used in the present study. A multiphase (gas-liquid-solid) pulsed discharge system was then formed by adding glasses beads immobilized with TiO2 photocatalyst into the discharge system. In the present paper, ultraviolet light produced during the pulsed discharge process was used as the lamp-house to induce the photocatalytic activity of the TiO2 photocatalyst. The synergistic effect of pulsed discharge and TiO2 photocatalysis was reviewed by the spectral diagnosis of hydroxyl radical ( *OH) in the pulsed discharge system. The obtained results showed that the emission spectrum of *OH could be observed at 306 nm (A2Sigma+-->X2II), 309 mn (A2Sigma+ (v' = 0) --> X2II (v" = 0)) and 313 nm (A2Sigma+ (v' = 1) --> X2II (v" = 1) transition). The relative emission intensity of *OH at 313 nm in the discharge system was the strongest among the three characteristic spectra. The relative emission intensity of *OH at 313 nm was stronger by adding TiO2 photocatalyst into the pulsed discharge system than that in the sole pulsed discharge system. In the case of experiments that changing the gas bubbling varieties and initial solution pH values, the results revealed that the relative emission intensity of *OH at 313 nm in the synergistic system was stronger when Ar was used as bubbling gas compared with that when air and oxygen were bubbled into the reaction system. Furthermore, the acidic solution system was favorable for producing more *OH, and therefore the corresponding emission intensity of *OH at 313 nm was stronger than that in the neutral and basic solution.

Lightning Mapping Observations: What we are learning.

NASA Astrophysics Data System (ADS)

Krehbiel, P.

2001-12-01

The use of radio frequency time-of-arrival techniques for accurately mapping lightning discharges is revolutionizing our ability to study lightning discharge processes and to investigate thunderstorms. Different types of discharges are being observed that we have not been able to study before or knew existed. Included are a variety of inverted and normal polarity intracloud and cloud-to-ground discharges, frequent short-duration discharges at high altitude in storms and in overshooting convective tops, highly energetic impulsive discharge events, and horizontally extensive `spider' lightning discharges in large mesoscale convective systems. High time resolution measurements valuably complement interferometric observations and are starting to exceed the ability of interferometers to provide detailed pictures of flash development. Mapping observations can be used to infer the polarity of the breakdown channels and hence the location and sign of charge regions in the storm. The lightning activity in large, severe storms is found to be essentially continuous and volume-filling, with substantially more lightning inside the storm than between the cloud and ground. Spectacular dendritic structures are observed in many flashes. The lightning observations can be used to infer the electrical structure of a storm and therefore to study the electrification processes. The results are raising fundamental questions about how storms become electrified and how the electrification evolves with time. Supercell storms are commonly observed to electrify in an inverted or anomalous manner, raising questions about how these storms are different from normal storms, and even what is `normal'. The high lightning rates in severe storms raises the distinct possibility that the discharges themselves might be sustaining or enhancing the electrification. Correlated observations with radar, instrumented balloons and aircraft, and ground-based measurements are leading to greatly improved

Experimental study on detection of electrostatic discharges generated by polymer granules inside a metal silo

NASA Astrophysics Data System (ADS)

Choi, Kwangseok; Mogami, Tomofumi; Suzuki, Teruo

2014-04-01

To detect electrostatic discharges generated by polymer granules within a metal silo, we developed a novel and simple electrostatic discharge detector that utilizes a photosensor. The novel detector consists of a photosensor module in a metal cylinder, an optical band-pass filter, a quartz glass, a power supply, an amplifier for the photosensor module, and a digital oscilloscope. In this study, we conducted experiments at a real pneumatic powder transport facility that includes a metal silo to evaluate the novel detector using polypropylene granules. To determine the performance of the novel detector, we observed the electrostatic discharge within the metal silo using a conventional image intensifier system. The results obtained from the experiments show that the novel detector worked well in this study. The signals obtained with the novel detector were identical to the electrostatic discharges obtained with the conventional image intensifier system. The greatest advantage of this novel detector is that it is effective even when placed under external lights. In addition, the influence of various optical band-pass filters on the performance of the novel detector was discussed. Our study confirmed that an optical band-pass filter with a center wavelength of λ 330 nm (λ1/2: 315-345 nm) was the best performer among the optical band-pass filters used in this study.

Experimental study on detection of electrostatic discharges generated by polymer granules inside a metal silo.

PubMed

Choi, Kwangseok; Mogami, Tomofumi; Suzuki, Teruo

2014-04-01

To detect electrostatic discharges generated by polymer granules within a metal silo, we developed a novel and simple electrostatic discharge detector that utilizes a photosensor. The novel detector consists of a photosensor module in a metal cylinder, an optical band-pass filter, a quartz glass, a power supply, an amplifier for the photosensor module, and a digital oscilloscope. In this study, we conducted experiments at a real pneumatic powder transport facility that includes a metal silo to evaluate the novel detector using polypropylene granules. To determine the performance of the novel detector, we observed the electrostatic discharge within the metal silo using a conventional image intensifier system. The results obtained from the experiments show that the novel detector worked well in this study. The signals obtained with the novel detector were identical to the electrostatic discharges obtained with the conventional image intensifier system. The greatest advantage of this novel detector is that it is effective even when placed under external lights. In addition, the influence of various optical band-pass filters on the performance of the novel detector was discussed. Our study confirmed that an optical band-pass filter with a center wavelength of λ 330 nm (λ1/2: 315-345 nm) was the best performer among the optical band-pass filters used in this study.

Non-discharging evapotranspiration bed system for wastewater disposal at Lincoln.

PubMed

Balley, P; Dakers, A J

1996-10-01

A non-discharging evapotranspiration bed system installed on a dairy farm at Lincoln University was studied to evaluate actual evapotranspiration rate, ET a , to develop and validate a water balance model for the system, and to assess the feasible application of the vaporative concept for wastewater disposal in the immediate geographic area. Observations, measurements, and calculations indicate that ET a was slightly higher than the meteorologically estimated Penman potential ET (ET p ) for the study period, and a ratio λ=ET a /ET p =1.21 was obtained. A water-balance equation of the system which can be used in different climatic conditions was obtained and can be written as ΔW=Q+PPTN-Et a ; where ΔW is the variation of storage water in the bed (in mm), Q is the effluent wastewater (in mm), and PPTN is the total precipitation. It was also observed that a truly non-discharging ET bed system's feasible application in the study location may be highly questionable. This is due to the fact that the precipitation rate for the location generally exceeds the ET p during critical Winter months. However, two possibilities of improving the performance of the system were found and suggested for further studies. The suggestions were (1) to design the system with its surface adequately crowned to shed large amounts of rain water falling on it, and (2) to design a winter-sheltered-non-discharging ET bed which would consist of an ET bed with a removable transparent plastic roof to shed the total amount of rain water and act as a 'green house'

The Role of Climatic Conditions in Controlling Observed Variability of Timing and Peak Discharge of Glacial Lake Outburst Floods: Lago Cachet Dos, Chile

NASA Astrophysics Data System (ADS)

Jacquet, J.; McCoy, S. W.; McGrath, D.; Nimick, D.; Friesen, B.; Fahey, M. J.; Leidich, J.; Okuinghttons, J.

2016-12-01

The sudden release of water from an ice-dammed lake poses substantial hazard to the downstream environment, but predicting the timing and magnitude of such an event is difficult. We use a series of high-resolution discharge measurements from a glacier-dammed lake, Lago Cachet Dos (LC2), during outburst events to evaluate the environmental conditions that influence the timing of initiation and peak discharge of observed glacial lake outburst floods (GLOFs). Since April 2008, 20 GLOFs have initiated out of LC2, located on the eastern edge of the Northern Patagonia Icefield, Chile and flooded areas along the Rio Colonia- Rio Baker system. GLOF frequency has averaged 2-3 events annually and peak discharges exiting LC2 have ranged widely from 2,000 to >15,000 m3 s-1. Although some LC2 GLOFs are consistent with global compilations relating peak discharge to lake volume, large deviations from the global trend and large intra-event variability are striking and call into question the predictive ability of simple empirical scaling equations. To evaluate the environmental conditions that lead to variability in observed peak discharge, we use a variation of the theoretical model of Nye (1976), which describes the process of englacial conduit evolution as a competition between thermally induced conduit growth and viscous flow of ice causing conduit collapse. We show that, consistent with theory, initial lake volume, lake temperature, and the rate of meltwater input into the glacially dammed lake all influence the peak discharge of measured GLOFs. Consequently, evolving climatic conditions of a region can greatly influence the potential hazard of GLOFs. Our results suggest that more accurate predictions of GLOF timing and magnitude from ice dammed lakes can be made by incorporating additional measurements of environmental conditions.

Lightning discharges produced by wind turbines

NASA Astrophysics Data System (ADS)

Montanyà, Joan; van der Velde, Oscar; Williams, Earle R.

2014-02-01

New observations with a 3-D Lightning Mapping Array and high-speed video are presented and discussed. The first set of observations shows that under certain thunderstorm conditions, wind turbine blades can produce electric discharges at regular intervals of 3 s in relation to its rotation, over periods of time that range from a few minutes up to hours. This periodic effect has not been observed in static towers indicating that the effect of rotation is playing a critical role. The repeated discharges can occur tens of kilometers away from electrically active thunderstorm areas and may or may not precede a fully developed upward lightning discharge from the turbine. Similar to rockets used for triggering lightning, the fast movement of the blade tip plays an important role on the initiation of the discharge. The movement of the rotor blades allows the tip to "runaway" from the generated corona charge. The second observation is an uncommon upward/downward flash triggered by a wind turbine. In that flash, a negative upward leader was initiated from a wind turbine without preceding lightning activity. The flash produced a negative cloud-to-ground stroke several kilometers from the initiation point. The third observation corresponds to a high-speed video record showing simultaneous upward positive leaders from a group of wind turbines triggered by a preceding intracloud flash. The fact that multiple leaders develop simultaneously indicates a poor shielding effect among them. All these observations provide some special features on the initiation of lightning by nonstatic and complex tall structures.

RF wave observations in beam-plasma discharge

NASA Technical Reports Server (NTRS)

Bernstein, W.

1986-01-01

The Beam Plasma Discharge (BPD) was produced in the large vacuum chamber at Johnson Space Center (20 x 30 m) using an energetic electron beam of moderately high perveance. A more complete expression of the threshold current I sub c taking into account the pitch angle injection dependence is given. Ambient plasma density inferred from wave measurements under various beam conditions are reported. Maximum frequency of the excited RF band behaves differently than the frequency of the peak amplitude. The latter shows signs of parabolic saturation consistent with the light data. Beam plasma state (pre-BPD or BPD) does not affect the pitch angle dependence. Unexpected strong modulation of the RF spectrum at half odd integer of the electron cyclotron frequency (n + 1/2)f sub ce is reported (5 n 10). Another new feature, the presence of wave emission around 3/2 f sub ce for I sub b is approximate I sub c is reported.

Multi-spark discharge system for preparation of nutritious water

NASA Astrophysics Data System (ADS)

Nakaso, Tetsushi; Harigai, Toru; Kusumawan, Sholihatta Aziz; Shimomura, Tomoya; Tanimoto, Tsuyoshi; Suda, Yoshiyuki; Takikawa, Hirofumi

2018-01-01

The nitrogen compound concentration in water is increased by atmospheric-pressure plasma discharge treatment. A rod-to-water electrode discharge treatment system using plasma discharge has been developed by our group to obtain water with a high concentration of nitrogen compounds, and this plasma-treated water improves the growth of chrysanthemum roots. However, it is difficult to apply the system to the agriculture because the amount of treated water obtained by using the system too small. In this study, a multi-spark discharge system (MSDS) equipped multiple spark plugs is presented to obtain a large amount of plasma-treated water. The MSDS consisted of inexpensive parts in order to reduce the system introduction cost for agriculture. To suppress the temperature increase of the spark plugs, the 9 spark plugs were divided into 3 groups, which were discharged in order. The plasma-treated water with a NO3- concentration of 50 mg/L was prepared using the MSDS for 90 min, and the treatment efficiency was about 6 times higher than that of our previous system. It was confirmed that the NO2-, O3, and H2O2 concentrations in the water were also increased by treating the water using the MSDS.

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

PubMed Central

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

2015-01-01

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

Experimental Investigation – Magnetic Assisted Electro Discharge Machining

NASA Astrophysics Data System (ADS)

Kesava Reddy, Chirra; Manzoor Hussain, M.; Satyanarayana, S.; Krishna, M. V. S. Murali

2018-04-01

Emerging technology needs advanced machined parts with high strength and temperature resistance, high fatigue life at low production cost with good surface quality to fit into various industrial applications. Electro discharge machine is one of the extensively used machines to manufacture advanced machined parts which cannot be machined by other traditional machine with high precision and accuracy. Machining of DIN 17350-1.2080 (High Carbon High Chromium steel), using electro discharge machining has been discussed in this paper. In the present investigation an effort is made to use permanent magnet at various positions near the spark zone to improve surface quality of the machined surface. Taguchi methodology is used to obtain optimal choice for each machining parameter such as peak current, pulse duration, gap voltage and Servo reference voltage etc. Process parameters have significant influence on machining characteristics and surface finish. Improvement in surface finish is observed when process parameters are set at optimum condition under the influence of magnetic field at various positions.

Large-scale hydrological model river storage and discharge correction using a satellite altimetry-based discharge product

NASA Astrophysics Data System (ADS)

Emery, Charlotte Marie; Paris, Adrien; Biancamaria, Sylvain; Boone, Aaron; Calmant, Stéphane; Garambois, Pierre-André; Santos da Silva, Joecila

2018-04-01

Land surface models (LSMs) are widely used to study the continental part of the water cycle. However, even though their accuracy is increasing, inherent model uncertainties can not be avoided. In the meantime, remotely sensed observations of the continental water cycle variables such as soil moisture, lakes and river elevations are more frequent and accurate. Therefore, those two different types of information can be combined, using data assimilation techniques to reduce a model's uncertainties in its state variables or/and in its input parameters. The objective of this study is to present a data assimilation platform that assimilates into the large-scale ISBA-CTRIP LSM a punctual river discharge product, derived from ENVISAT nadir altimeter water elevation measurements and rating curves, over the whole Amazon basin. To deal with the scale difference between the model and the observation, the study also presents an initial development for a localization treatment that allows one to limit the impact of observations to areas close to the observation and in the same hydrological network. This assimilation platform is based on the ensemble Kalman filter and can correct either the CTRIP river water storage or the discharge. Root mean square error (RMSE) compared to gauge discharges is globally reduced until 21 % and at Óbidos, near the outlet, RMSE is reduced by up to 52 % compared to ENVISAT-based discharge. Finally, it is shown that localization improves results along the main tributaries.

The n-by-T Target Discharge Strategy for Inpatient Units.

PubMed

Parikh, Pratik J; Ballester, Nicholas; Ramsey, Kylie; Kong, Nan; Pook, Nancy

2017-07-01

Ineffective inpatient discharge planning often causes discharge delays and upstream boarding. While an optimal discharge strategy that works across all units at a hospital is likely difficult to identify and implement, a strategy that provides a reasonable target to the discharge team appears feasible. We used observational and retrospective data from an inpatient trauma unit at a Level 2 trauma center in the Midwest US. Our proposed novel n-by-T strategy-discharge n patients by the Tth hour-was evaluated using a validated simulation model. Outcome measures included 2 measures: time-based (mean discharge completion and upstream boarding times) and capacity-based (increase in annual inpatient and upstream bed hours). Data from the pilot implementation of a 2-by-12 strategy at the unit was obtained and analyzed. The model suggested that the 1-by-T and 2-by-T strategies could advance the mean completion times by over 1.38 and 2.72 h, respectively (for 10 AM ≤ T ≤ noon, occupancy rate = 85%); the corresponding mean boarding time reductions were nearly 11% and 15%. These strategies could increase the availability of annual inpatient and upstream bed hours by at least 2,469 and 500, respectively. At 100% occupancy rate, the hospital-favored 2-by-12 strategy reduced the mean boarding time by 26.1%. A pilot implementation of the 2-by-12 strategy at the unit corroborated with the model findings: a 1.98-h advancement in completion times (P<0.0001) and a 14.5% reduction in boarding times (P = 0.027). Target discharge strategies, such as the n-by-T, can help substantially reduce discharge lateness and upstream boarding, especially during high unit occupancy. To sustain implementation, necessary commitment from the unit staff and physicians is vital, and may require some training.

Wall conditioning by ECRH discharges and He-GDC in the limiter phase of Wendelstein 7-X

NASA Astrophysics Data System (ADS)

Wauters, T.; Brakel, R.; Brezinsek, S.; Dinklage, A.; Goriaev, A.; Laqua, H. P.; Marsen, S.; Moseev, D.; Stange, T.; Schlisio, G.; Pedersen, T. Sunn; Volzke, O.; Wenzel, U.; the W7-X Team

2018-06-01

Wendelstein 7-X (W7-X) relies on wall conditioning to control the density and the impurity content of the plasma. Wall conditioning in the first operation campaign of W7-X consisted of baking at 150 °C during 1 week prior to operation, glow discharge conditioning (GDC) in helium (He) and electron cyclotron resonance heating (ECRH) discharges. Additionally, the usage of He-GDC was limited to avoid sputtering and migration of metallic plasma facing components. This presented a unique opportunity for studying the applicability of ECRH discharges for initial wall conditioning on a stellarator, albeit in the carbon limiter configuration. A single envelope curve is observed in the normalised outgassing data that takes into account all ECRH discharges. This illustrates that the majority of discharges operates at the limits of a radiative collapse. Hydrogen recycling dominated the fuelling of ECRH discharges throughout while CO outgassing was found strongest at the start of the campaign. A reduction of recycling was observed throughout the campaign. Temporarily depleting the walls from H and impurities was possible by He-GDC. It was shown that the recycling coefficient in -ECRH plasmas could be reduced and the pulse duration significantly extended by He-’recovery’ ECRH plasmas. Good wall conditions were defined by normalised outgassing values below mbar kJ‑1. In absence of -GDC, more than 311 cumulated discharge seconds of ECRH discharges are needed for obtaining lasting low outgassing levels. A release model with two trapping reservoirs could reproduce the normalised outgassing trend, including ECRH and GDC plasma wall interactions.

Bent paths of a positive streamer and a cathode-directed spark leader in diffuse discharges preionized by runaway electrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Cheng; Shao, Tao, E-mail: st@mail.iee.ac.cn; Wang, Ruixue

2015-03-15

Diffuse discharges preionized by runaway electrons can produce large-area homogeneous discharges at elevated pressures, which is an intriguing phenomenon in the physics of pulsed discharges. In this paper, runaway-electron-preionized diffuse discharge (REP DD) was obtained in a wide pressure range (0.05–0.25 MPa), and under certain conditions a positive streamer and a cathode-directed spark leader could be observed to propagate at some angles to the applied (background) electric field lines. For a 16-mm gap at an air pressure of 0.08–0.1 MPa, the percentage of pulses in which such propagation is observed is about 5%–50% of their total number, and in the other pulsesmore » such bent paths could not be observed because there is even no streamer or cathode-directed spark leader in diffuse discharges. In our opinion, such propagation of the positive streamer and the cathode-directed spark leader at some angle to the background electric field lines owes to different increase rates of the electron density in different regions of the discharge volume under REP DD conditions. Therefore, during the formation of a REP DD, the increase of the electron density is inhomogeneous and nonsimultaneous, resulting in an electron density gradient at the ionization wave front.« less

Development and feasibility testing of the Pediatric Emergency Discharge Interaction Coding Scheme.

PubMed

Curran, Janet A; Taylor, Alexandra; Chorney, Jill; Porter, Stephen; Murphy, Andrea; MacPhee, Shannon; Bishop, Andrea; Haworth, Rebecca

2017-08-01

Discharge communication is an important aspect of high-quality emergency care. This study addresses the gap in knowledge on how to describe discharge communication in a paediatric emergency department (ED). The objective of this feasibility study was to develop and test a coding scheme to characterize discharge communication between health-care providers (HCPs) and caregivers who visit the ED with their children. The Pediatric Emergency Discharge Interaction Coding Scheme (PEDICS) and coding manual were developed following a review of the literature and an iterative refinement process involving HCP observations, inter-rater assessments and team consensus. The coding scheme was pilot-tested through observations of HCPs across a range of shifts in one urban paediatric ED. Overall, 329 patient observations were carried out across 50 observational shifts. Inter-rater reliability was evaluated in 16% of the observations. The final version of the PEDICS contained 41 communication elements. Kappa scores were greater than .60 for the majority of communication elements. The most frequently observed communication elements were under the Introduction node and the least frequently observed were under the Social Concerns node. HCPs initiated the majority of the communication. Pediatric Emergency Discharge Interaction Coding Scheme addresses an important gap in the discharge communication literature. The tool is useful for mapping patterns of discharge communication between HCPs and caregivers. Results from our pilot test identified deficits in specific areas of discharge communication that could impact adherence to discharge instructions. The PEDICS would benefit from further testing with a different sample of HCPs. © 2017 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

Characterization of microwave discharge plasmas for surface processing

NASA Astrophysics Data System (ADS)

Nikolic, Milka

We have developed several diagnostic techniques to characterize two types of microwave (MW) discharge plasmas: a supersonic flowing argon MW discharge maintained in a cylindrical quartz cavity at frequency ƒ = 2.45 GHz and a pulse repetitive MW discharge in air at ƒ = 9.5 GHz. Low temperature MW discharges have been proven to posses attractive properties for plasma cleaning and etching of niobium surfaces of superconductive radio frequency (SRF) cavities. Plasma based surface modification technologies offer a promising alternative for etching and cleaning of SRF cavities. These technologies are low cost, environmentally friendly and easily controllable, and present a possible alternative to currently used acid based wet technologies, such as buffered chemical polishing (BCP), or electrochemical polishing (EP). In fact, weakly ionized. non-equilibrium, and low temperature gas discharges represent a powerful tool for surface processing due to the strong chemical reactivity of plasma radicals. Therefore, characterizing these discharges by applying non-perturbing, in situ measurement techniques is of vital importance. Optical emission spectroscopy has been employed to analyze the molecular structure and evaluate rotational and vibrational temperatures in these discharges. The internal plasma structure was studied by applying a tomographic numerical method based on the two-dimensional Radon formula. An automated optical measurement system has been developed for reconstruction of local plasma parameters. It was found that excited argon states are concentrated near the tube walls, thus confirming the assumption that the post discharge plasma is dominantly sustained by a travelling surface wave. Employing a laser induced fluorescence technique in combination with the time synchronization device allowed us to obtain time-resolved population densities of some excited atomic levels in argon. We have developed a technique for absolute measurements of electron density based

Design of a fast computer-based partial discharge diagnostic system

NASA Technical Reports Server (NTRS)

Oliva, Jose R.; Karady, G. G.; Domitz, Stan

1991-01-01

Partial discharges cause progressive deterioration of insulating materials working in high voltage conditions and may lead ultimately to insulator failure. Experimental findings indicate that deterioration increases with the number of discharges and is consequently proportional to the magnitude and frequency of the applied voltage. In order to obtain a better understanding of the mechanisms of deterioration produced by partial discharges, instrumentation capable of individual pulse resolution is required. A new computer-based partial discharge detection system was designed and constructed to conduct long duration tests on sample capacitors. This system is capable of recording large number of pulses without dead time and producing valuable information related to amplitude, polarity, and charge content of the discharges. The operation of the system is automatic and no human supervision is required during the testing stage. Ceramic capacitors were tested at high voltage in long duration tests. The obtained results indicated that the charge content of partial discharges shift towards high levels of charge as the level of deterioration in the capacitor increases.

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

PubMed

Sekimoto, Kanako; Takayama, Mitsuo

2011-01-01

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

Comparison of fungicidal properties of non-thermal plasma produced by corona discharge and dielectric barrier discharge.

PubMed

Julák, J; Soušková, H; Scholtz, V; Kvasničková, E; Savická, D; Kříha, V

2018-01-01

The inactivation of four micromycete species by action of non-thermal plasma was followed. Two sources of plasma were compared, namely, positive corona discharge and dielectric barrier discharge. The corona discharge appeared as suitable for fungal spore inactivation in water suspension, whereas the barrier discharge inactivated spores on the surface of cultivation agar. Cladosporium sphaerospermum was the most sensitive, being inactivated within 10 min of exposure to plasma, whereas Aspergillus oryzae displayed decrease in viable cell count only, the complete inactivation was not achieved even after 40 min of exposure. Intermediate sensitivity was found for Alternaria sp. and Byssochlamys nivea. The significant delay of growth was observed for all fungi after exposure to sublethal dose of plasma, but we failed to express this effect quantitatively.

Discharge transient coupling in large space power systems

NASA Technical Reports Server (NTRS)

Stevens, N. John; Stillwell, R. P.

1990-01-01

Experiments have shown that plasma environments can induce discharges in solar arrays. These plasmas simulate the environments found in low earth orbits where current plans call for operation of very large power systems. The discharges could be large enough to couple into the power system and possibly disrupt operations. Here, the general concepts of the discharge mechanism and the techniques of coupling are discussed. Data from both ground and flight experiments are reviewed to obtain an expected basis for the interactions. These concepts were applied to the Space Station solar array and distribution system as an example of the large space power system. The effect of discharges was found to be a function of the discharge site. For most sites in the array discharges would not seriously impact performance. One location at the negative end of the array was identified as a position where discharges could couple to charge stored in system capacitors. This latter case could impact performance.

Characteristics of Capacity Coupled Discharge in Atmospheric Pressure Air

NASA Astrophysics Data System (ADS)

Sasaki, Tadahiro; Omukai, Reina; Mukaigawa, Seiji; Takaki, Koichi; Fujiwara, Tamiya; Mase, Hiroshi; Sato, Noriyoshi

This paper describes characteristics of capacity coupled discharge in atmospheric pressure air with focusing influence of gap length of point-to-plane electrode configuration on input power into the discharge. The discharge can be quenched in short time duration by inserting a small capacitance capacitor between the electrode and the ground. We employed a needle electrode and a coaxial cable as the quenching capacitor. The discharge was successfully quenched within 25 ns in duration according to 9.4 pF in a capacitance of the quenching capacitor. The discharge was classified as two modes; a spark mode and a corona mode. At the spark mode, the power consumed in the discharge plasma was almost 10 times as large as that of a conventional dielectric barrier discharge. At the corona mode, the consumed energy was almost same value with that of the dielectric barrier discharge. A velocity of the discharge development was obtained to be 3×105 m/s by an optical measurement.

Electrochemical cell with high discharge/charge rate capability

DOEpatents

Redey, Laszlo

1988-01-01

A fully charged positive electrode composition for an electrochemical cell includes FeS.sub.2 and NiS.sub.2 in about equal molar amounts along with about 2-20 mole percent of the reaction product Li.sub.2 S. Through selection of appropriate electrolyte compositions, high power output or low operating temperatures can be obtained. The cell includes a substantially constant electrode impedance through most of its charge and discharge range. Exceptionally high discharge rates and overcharge protection are obtainable through use of the inventive electrode composition.

Subglacial discharge at tidewater glaciers revealed by seismic tremor

PubMed Central

Amundson, Jason M.; Walter, Jacob I.; O'Neel, Shad; West, Michael E.; Larsen, Christopher F.

2015-01-01

Abstract Subglacial discharge influences glacier basal motion and erodes and redeposits sediment. At tidewater glacier termini, discharge drives submarine terminus melting, affects fjord circulation, and is a central component of proglacial marine ecosystems. However, our present inability to track subglacial discharge and its variability significantly hinders our understanding of these processes. Here we report observations of hourly to seasonal variations in 1.5–10 Hz seismic tremor that strongly correlate with subglacial discharge but not with basal motion, weather, or discrete icequakes. Our data demonstrate that vigorous discharge occurs from tidewater glaciers during summer, in spite of fast basal motion that could limit the formation of subglacial conduits, and then abates during winter. Furthermore, tremor observations and a melt model demonstrate that drainage efficiency of tidewater glaciers evolves seasonally. Glaciohydraulic tremor provides a means by which to quantify subglacial discharge variations and offers a promising window into otherwise obscured glacierized environments. PMID:27667869

Subglacial discharge at tidewater glaciers revealed by seismic tremor

USGS Publications Warehouse

Bartholomaus, Timothy C.; Amundson, Jason M.; Walter, Jacob I.; O'Neel, Shad; West, Michael E.; Larsen, Christopher F.

2015-01-01

Subglacial discharge influences glacier basal motion and erodes and redeposits sediment. At tidewater glacier termini, discharge drives submarine terminus melting, affects fjord circulation, and is a central component of proglacial marine ecosystems. However, our present inability to track subglacial discharge and its variability significantly hinders our understanding of these processes. Here we report observations of hourly to seasonal variations in 1.5–10 Hz seismic tremor that strongly correlate with subglacial discharge but not with basal motion, weather, or discrete icequakes. Our data demonstrate that vigorous discharge occurs from tidewater glaciers during summer, in spite of fast basal motion that could limit the formation of subglacial conduits, and then abates during winter. Furthermore, tremor observations and a melt model demonstrate that drainage efficiency of tidewater glaciers evolves seasonally. Glaciohydraulic tremor provides a means by which to quantify subglacial discharge variations and offers a promising window into otherwise obscured glacierized environments.

Direct observation of ozone formation on SiO2 surfaces in O2 discharges

NASA Astrophysics Data System (ADS)

Marinov, D.; Guaitella, O.; Booth, J. P.; Rousseau, A.

2013-01-01

Ozone production is studied in a pulsed O2 discharge at pressures in the range 1.3-6.7 mbar. Time-resolved absolute concentrations of O3 and O are measured in the post-discharge using UV absorption spectroscopy and two-photon absorption laser-induced fluorescence. In a bare silica discharge tube ozone is formed mainly by three-body gas-phase recombination. When the tube surface is covered by a high specific surface silica catalyst heterogeneous formation becomes the main source of ozone. The efficiency of this surface process increases with O2 pressure and is favoured by the presence of OH groups and adsorbed H2O on the surface. At p = 6.7 mbar ozone production accounts for up to 25% of the atomic oxygen losses on the surface.

Observatory enabled discovery of diffuse discharge temperature structure

NASA Astrophysics Data System (ADS)

Bemis, K. G.; Lee, R.; Ivakin, A. N.

2016-12-01

Underwater cabled observatories provide long term but short time and spatial scale measurements of hydrothermal discharge properties. For the first time, an intricate picture of diffuse discharge has been captured at both Axial Volcano (Axial) and the Main Endeavour Field (MEF) on the Juan de Fuca Ridge. This study combines thermistor (3D array, 2D array and spot) and acoustic data to compare the statistical and distribution characteristics of diffuse discharge for narrow crack flow (at ASHES field on Axial) and distributive flow out of a sulfide structure (at Grotto vent in MEF). Two surprising observations seem to apply to both styles of diffuse discharge: (1) thermal variance scales with the mean temperature suggesting coherent flow structures exist in the form of plumes, wakes or boundary layers, and (2) thermal hot spots are persistently localized in space, despite tidal current disruption. Thermal variance was measured at ASHES using a 3D thermistor array (TMPSF) with 10 s sampling over two years and at Grotto using 2D thermistor arrays with 1 hr sampling over several years and a ROV-held CTD (Seabird 39plus) with 0.5 second sampling over several minutes. For locations with temperatures greater than ambient, the variance in temperature scales with the mean temperature. This unusual statistical property is characteristic of self-similar flows like plumes, wakes, and boundary layers and arises from the bounded mixing of a cooling high temperature fluid with a cold ambient fluid. Thus this observation implies an underlying coherence to the diffuse discharge that has not yet been adequately captured or described. A coherent flow like a plume should have a discoverable spatial pattern, albeit one that may vary with the influence of tides. Acoustic observations ( 1m diameter footprint) of the Grotto sulfide edifice found stable local hot spots of diffuse discharge that sway with tides. In contrast, the 3D thermistor array at ASHES sees very localized (single

Breakdown of methylene blue and methyl orange by pulsed corona discharge

NASA Astrophysics Data System (ADS)

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

2007-05-01

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

NPDES (National Pollution Discharge & Elimination System) Minor Dischargers

EPA Pesticide Factsheets

As authorized by the Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) permit program controls water pollution by regulating point sources that discharge pollutants into waters of the United States. The NPDES permit program regulates direct discharges from municipal and industrial wastewater treatment facilities that discharge directly into surface waters. The NPDES permit program is part of the Permit Compliance System (PCS) which issues, records, tracks, and regulates point source discharge facilities. Individual homes that are connected to a municipal system, use a septic system, or do not have a surface discharge do not need an NPDES permit. Facilities in PCS are identified as either major or minor. Within the major/minor classification, facilities are grouped into municipals or non-municipals. In many cases, non-municipals are industrial facilities. This data layer contains Minor dischargers. Major municipal dischargers include all facilities with design flows of greater than one million gallons per day; minor dischargers are less that one million gallons per day. Essentially, a minor discharger does not meet the discharge criteria for a major. Since its introduction in 1972, the NPDES permit program is responsible for significant improvements to our Nation's water quality.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Effectiveness of syndromic management for male patients with urethral discharge symptoms in Amazonas, Brazil.

PubMed

Menezes Filho, Jonas Rodrigues de; Sardinha, José Carlos Gomes; Galbán, Enrique; Saraceni, Valéria; Talhari, Carolina

2017-01-01

Urethral discharge syndrome (UDS) is characterized by the presence of purulent or mucopurulent urethral discharge.The main etiological agents of this syndrome are Neisseria gonorrhoeae and Chlamydia trachomatis. To evaluate the effectiveness of the syndromic management to resolve symptoms in male urethral discharge syndrome cases in Manaus, Amazonas, Brazil. Retrospective cohort of male cases of urethral discharge syndrome observed at a clinic for sexually transmitted disease (STD) in 2013. Epidemiological and clinical data, as well as the results of urethral swabs, bacterioscopy, hybrid capture for C.trachomatis, wet-mount examination, and culture for N.gonorrhoeae, were obtained through medical chart reviews. Of the 800 urethral discharge syndrome cases observed at the STD clinic, 785 (98.1%) presented only urethral discharge syndrome, 633 (79.1%) returned for follow-up, 579 (91.5%) were considered clinically cured on the first visit, 41(6.5 %) were considered cured on the second visit, and 13(2.0%) did not reach clinical cure after two appointments. Regarding the etiological diagnosis, 42.7% of the patients presented a microbiological diagnosis of N.gonorrhoeae, 39.3% of non-gonococcal and non-chlamydia urethritis, 10.7% of C.trachomatis and 7.3% of co-infection with chlamydia and gonococcus. The odds of being considered cured in the first visit were greater in those who were unmarried, with greater schooling, and with an etiological diagnosis of gonorrhea. The diagnosis of non-gonococcal urethritis reduced the chance of cure in the first visit. A study conducted at a single center of STD treatment. Syndromic management of male urethral discharge syndrome performed in accordance with the Brazilian Ministry of Health STD guidelines was effective in resolving symptoms in the studied population. More studies with microbiological outcomes are needed to ensure the maintenance of the syndromic management.

Effectiveness of syndromic management for male patients with urethral discharge symptoms in Amazonas, Brazil*

PubMed Central

de Menezes Filho, Jonas Rodrigues; Sardinha, José Carlos Gomes; Galbán, Enrique; Saraceni, Valéria; Talhari, Carolina

2017-01-01

Background Urethral discharge syndrome (UDS) is characterized by the presence of purulent or mucopurulent urethral discharge.The main etiological agents of this syndrome are Neisseria gonorrhoeae and Chlamydia trachomatis. Objectives To evaluate the effectiveness of the syndromic management to resolve symptoms in male urethral discharge syndrome cases in Manaus, Amazonas, Brazil. Methods Retrospective cohort of male cases of urethral discharge syndrome observed at a clinic for sexually transmitted disease (STD) in 2013. Epidemiological and clinical data, as well as the results of urethral swabs, bacterioscopy, hybrid capture for C.trachomatis, wet-mount examination, and culture for N.gonorrhoeae, were obtained through medical chart reviews. Results Of the 800 urethral discharge syndrome cases observed at the STD clinic, 785 (98.1%) presented only urethral discharge syndrome, 633 (79.1%) returned for follow-up, 579 (91.5%) were considered clinically cured on the first visit, 41(6.5 %) were considered cured on the second visit, and 13(2.0%) did not reach clinical cure after two appointments. Regarding the etiological diagnosis, 42.7% of the patients presented a microbiological diagnosis of N.gonorrhoeae, 39.3% of non-gonococcal and non-chlamydia urethritis, 10.7% of C.trachomatis and 7.3% of co-infection with chlamydia and gonococcus. The odds of being considered cured in the first visit were greater in those who were unmarried, with greater schooling, and with an etiological diagnosis of gonorrhea. The diagnosis of non-gonococcal urethritis reduced the chance of cure in the first visit. Study limitation A study conducted at a single center of STD treatment. Conclusion Syndromic management of male urethral discharge syndrome performed in accordance with the Brazilian Ministry of Health STD guidelines was effective in resolving symptoms in the studied population. More studies with microbiological outcomes are needed to ensure the maintenance of the syndromic

Surface flow observations from a gauge-cam station on the Tiber river

NASA Astrophysics Data System (ADS)

Tauro, Flavia; Porfiri, Maurizio; Petroselli, Andrea; Grimaldi, Salvatore

2016-04-01

Understanding the kinematic organization of natural water bodies is central to hydrology and environmental engineering practice. Reliable and continuous flow observations are essential to comprehend flood generation and propagation mechanisms, erosion dynamics, sediment transport, and drainage network evolution. In engineering practice, flood warning systems largely rely on real-time discharge measurements, and flow velocity monitoring is important for the design and management of hydraulic structures, such as reservoirs and hydropower plants. Traditionally, gauging stations have been equipped with water level meters, and stage-discharge relationships (rating curves) have been established through few direct discharge measurements. Only in rare instances, monitoring stations have integrated radar technology for local measurement of surface flow velocity. Establishing accurate rating curves depends on the availability of a comprehensive range of discharge values, including measurements recorded during extreme events. However, discharge values during high-flow events are often difficult or even impossible to obtain, thereby hampering the reliability of discharge predictions. Fully remote observations have been enabled in the past ten years through optics-based velocimetry techniques. Such methodologies enable the estimation of the surface flow velocity field over extended regions from the motion of naturally occurring debris or floaters dragged by the current. Resting on the potential demonstrated by such approaches, here, we present a novel permanent gauge-cam station for the observation of the flow velocity field in the Tiber river. This new station captures one-minute videos every 10 minutes over an area of up to 20.6 × 15.5m2. In a feasibility study, we demonstrate that experimental images analyzed via particle tracking velocimetry and particle image velocimetry can be used to obtain accurate surface flow velocity estimations in close agreement with radar records

Production of atmospheric-pressure glow discharge in nitrogen using needle-array electrode

NASA Astrophysics Data System (ADS)

Takaki, K.; Hosokawa, M.; Sasaki, T.; Mukaigawa, S.; Fujiwara, T.

2005-04-01

An atmospheric pressure glow discharge was generated using a needle-array electrode in nitrogen, and the voltage-current characteristics of the glow discharge were obtained in a range from 1 mA to 60 A. A pulsed high voltage with short rise time under 10 ns was employed to generate streamer discharges simultaneously at all needle tips. The large number of streamer discharges prevented the glow-to-arc transition caused by inhomogeneous thermalization. Semiconductor opening switch diodes were employed as an opening switch to shorten the rise time. The glow voltage was almost constant until the discharge current became 0.3 A, whereas the voltage increased with the current higher than 0.3 A. Electron density and temperature in a positive column of the glow discharge at 60 A were obtained to 1.4×1012cm-3 and 1.3 eV from calculation based on nitrogen swarm data.

Field Assessment of Acoustic-Doppler Based Discharge Measurements

USGS Publications Warehouse

Mueller, D.S.; ,

2002-01-01

The use of equipment based on the Doppler principle for measuring water velocity and computing discharge is common within the U.S. Geological Survey (USGS). The instruments and software have changed appreciably during the last 5 years; therefore, the USGS has begun a field validation of the instruments currently (2002) available for making discharge measurements from a moving boat in streams of various sizes. Instruments manufactured by SonTek/YSI2 and RD Instruments, Inc. were used to collect discharge data at five different sites. One or more traditional discharge measurements were made by the use of a Price AA current meter and standard USGS procedures with the acoustic instruments at each site during data collection. The discharges measured with the acoustic instruments were compared with the discharges measured with Price AA meters and the current USGS stage-discharge rating for each site. The mean discharges measured by each acoustic instrument were within 5 percent of the Price AA-based measurement and (or) discharge from the stage-discharge rating. Additional analysis of the data collected indicates that the coefficient of variation of the discharge measurements consistently was less for the RD Instruments, Inc. Rio Grandes than it was for the SonTek/YSI RiverSurveyors. The bottom-tracking referenced measurement had a lower coefficient of variation than the differentially corrected global positioning system referenced measurements. It was observed that the higher frequency RiverSurveyors measured a moving bed more often than the lower frequency Rio Grandes. The detection of a moving bed caused RiverSurveyors to be consistently biased low when referenced to bottom tracking. Differentially corrected global positioning system data may be used to remove the bias observed in the bottom-tracking referenced measurements.

Stereotactic radiosurgery - discharge

MedlinePlus

Gamma knife - discharge; Cyberknife - discharge; Stereotactic radiotherapy - discharge; Fractionated stereotactic radiotherapy - discharge; Cyclotrons - discharge; Linear accelerator - discharge; Lineacs - discharge; Proton beam radiosurgery - discharge

Discharge estimation in arid areas with the help of optical satellite data

NASA Astrophysics Data System (ADS)

Mett, M.; Aufleger, M.

2009-04-01

The MENA region is facing severe water scarcity. Overexploitation of groundwater resources leads to an ongoing drawdown of the water tables, salinisation and desertification of vast areas. To make matters worse enormous birth-rates, economic growth and refugees from conflict areas let the need for water explode. In the context of climate change this situation will even worsen and armed conflicts are within the bounds of possibility. To ease water scarcity many innovative techniques like artificial groundwater recharge are being developed or already state of the art. But missing hydrological information (for instance discharge data) often prevents design and efficient operation of such measures. Especially in poor countries hydrological measuring devices like gage stations are often missing, in a bad status or professionals of the water sector are absent. This leads to the paradox situation that in many arid regions water resources are indeed available but they cannot be utilised because they are not known. Nowadays different approaches are being designed to obtain hydrological information from perennial river systems with the help of satellite techniques. Mostly they are based on hydraulic parameters like river dimensions, roughness and water levels which can be derived from satellite data. By using conventional flow formulas and additional field investigations the discharge can be estimated. Another methodology derived information about maximum flow depth and flow width from optical sensors of high resolution to calculate discharge of the rivers whilst the flood. Attempts to derive discharge information from structural components of the river and fluviomorphologic changes due to changing flow regimes are in the focus of recent research. One attempt used Synthetic Aperture Radar (SAR) data to estimate discharge in braided river systems. Other attempts used airborne SAR imagery to obtain information about sinuosity and total river width of perennial braided river

Diffusion cannot govern the discharge of neurotransmitter in fast synapses.

PubMed Central

Khanin, R; Parnas, H; Segel, L

1994-01-01

In the present work we show that diffusion cannot provide the observed fast discharge of neurotransmitter from a synaptic vesicle during neurotransmitter release, mainly because it is not sufficiently rapid nor is it sufficiently temperature-dependent. Modeling the discharge from the vesicle into the cleft as a continuous point source, we have determined that discharge should occur in 50-75 microseconds, to provide the observed high concentrations of transmitter at the critical zone. Images FIGURE 5 PMID:7811953

Observation of an abrupt electron heating mode transition in capacitive single radio frequency discharges

NASA Astrophysics Data System (ADS)

Wilczek, Sebastian; Trieschmann, Jan; Schulze, Julian; Brinkmann, Ralf Peter; Mussenbrock, Thomas; Derzsi, Aranka; Korolov, Ihor; Donkó, Zoltan

2013-09-01

The electron heating in capacitive discharges at very low pressures (~1 Pa) is dominated by stochastic heating. In this regime electrons are accelerated by the oscillating sheaths, traverse through the plasma bulk and interact with the opposite sheath. By varying the driving frequency or the gap size of the discharge, energetic electrons reach the sheath edge at different temporal phases, i.e., the collapsing or expanding phase, or the moment of minimum sheath width. This work reports numerical experiments based on Particle-In-Cell simulations which show that at certain frequencies the discharge switches abruptly from a low density mode in a high density mode. The inverse transition is also abrupt, but shows a significant hysteresis. This behavior is explained by the complex interaction of the bulk and the sheath. This work is supported by the German Research Foundation in the frame of TRR 87.

Drug-related problems at discharge: results on the Spanish pharmacy discharge programme CONSULTENOS.

PubMed

López, Maángeles Pardo; Saliente, Ma Teresa Aznar; Company, Enrique Soler; Monsalve, Ana Garcia; Cueva, Marta Aparício; Domingo, Elena Arroyo; Hernández, Monica Montero; Carrión, Carmen Carrión; Martí, Monica Climente; Querejeta, Nuria Bujaldón; Blasco, Joaquín Borrás; Milá, Amparo Rocher

2010-10-01

The aim of this study was to describe the most common drug-related problems (DRPs) found after discharge, pharmacist interventions and their results for the patients enrolled on the CONSULTENOS programme. An observational, prospective, multicentre study was conducted to evaluate the results of a pharmaceutical care programme at discharge. Patients from 10 hospitals participating in the CONSULTENOS programme were enrolled. Pharmacists conducting this programme were newly graduated and worked under the supervision of a pharmacy staff member; only two pharmacists had previous hospital pharmacy experience. DRPs were identified and classified according to the Iaser methodology. Frequencies, types of DRP, interventions and outcomes were registered prospectively, at discharge and during a follow-up call 7 days after leaving the hospital. A total of 7711 patients were included in the study. DRPs were detected in 23.7% of the patients, with a total of 2120 DRPs (1788 at discharge and 332 in the follow-up). The most common problems identified at discharge were twofold: firstly the need of an additional treatment (34.1%) and secondly an unnecessary treatment (18.1%). In the follow-up phone call the most frequent DRPs were adverse effects (29.2%). Besides the standard educational interventions at discharge, 3313 extra interventions were performed, of which 85% were accepted. The outcomes for the patients were positive in 80% of the cases, although documentation with objective or subjective data was rare. DRPs occur frequently after patient discharge. A pharmaceutical care programme can identify and solve DRPs in this scenario. The clinical impact of the pharmacists' interventions should be better addressed. © 2010 The Authors. IJPP © 2010 Royal Pharmaceutical Society of Great Britain.

Recent studies on nanosecond-timescale pressurized gas discharges

DOE PAGES

Yatom, S.; Shlapakovski, A.; Beilin, L.; ...

2016-10-05

The results of recent experimental and numerical studies of nanosecond high-voltage discharges in pressurized gases are reviewed. The discharges were ignited in a diode filled by different gases within a wide range of pressures by an applied pulsed voltage or by a laser pulse in the gas-filled charged resonant microwave cavity. Fast-framing imaging of light emission, optical emission spectroscopy, X-ray foil spectrometry and coherent anti-Stokes Raman scattering were used to study temporal and spatial evolution of the discharge plasma density and temperature, energy distribution function of runaway electrons and dynamics of the electric field in the plasma channel. The resultsmore » obtained allow a deeper understanding of discharge dynamical properties in the nanosecond timescale, which is important for various applications of these types of discharges in pressurized gases.« less

Numerical modelling of the effect of dry air traces in a helium parallel plate dielectric barrier discharge

NASA Astrophysics Data System (ADS)

Lazarou, C.; Belmonte, T.; Chiper, A. S.; Georghiou, G. E.

2016-10-01

A validated numerical model developed for the study of helium barrier discharges in the presence of dry air impurities is presented in this paper. The model was used to numerically investigate the influence of air traces on the evolution of the helium dielectric barrier discharge (DBD). The level of dry air used as impurity was in the range from 0 to 1500 ppm, which corresponds to the most commonly encountered range in atmospheric pressure discharge experiments. The results presented in this study clearly show that the plasma chemistry and consequently the discharge evolution is highly affected by the concentration level of impurities in the mixture. In particular, it was observed that air traces assist the discharge ignition at low concentration levels (~55 ppm), while on the other hand, they increase the burning voltage at higher concentration levels (~1000 ppm). Furthermore, it was found that the discharge symmetry during the voltage cycle highly depends on the concentration of air. For the interpretation of the results, a detailed analysis of the processes that occur in the discharge gap is performed and the main reaction pathways of ion production are described. Thanks to this approach, useful insight into the physics behind the evolution of the discharge is obtained.

Synergistic effects of liquid and gas phase discharges using pulsed high voltage for dyes degradation in the presence of oxygen.

PubMed

Yang, Bin; Zhou, Minghua; Lei, Lecheng

2005-07-01

The technology of combined liquid and gas phase discharges (LGD) using pulsed high voltage for dyes degradation was developed in this study. Apparent synergistic effects for Acid orange II (AO) degradation in the presence of oxygen were observed. The enhancement of AO degradation rate was around 302%. Furthermore, higher energy efficiency was obtained comparing with individual liquid phase discharge (LD) or gas phase discharge process (GD). The AO degradation in the presence of oxygen by LGD proceeded through the direct ozone oxidation and the ozone decomposition induced by LD. Important operating parameters such as electrode distance, applied voltage, pulse repetition rate, and types of dyes were further investigated.

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

NASA Astrophysics Data System (ADS)

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

2005-02-01

Ozone formation by a pulse positive corona discharge generated in the gas phase between a planar high voltage electrode made from reticulated vitreous carbon and a water surface with an immersed ground stainless steel plate electrode was investigated under various operating conditions. The effects of gas flow rate (0.5-3 litre min-1), discharge gap spacing (2.5-10 mm), applied input power (2-45 W) and gas composition (oxygen containing argon or nitrogen) on ozone production were determined. Ozone concentration increased with increasing power input and with increasing discharge gap. The production of ozone was significantly affected by the presence of water vapour formed through vaporization of water at the gas-liquid interface by the action of the gas phase discharge. The highest energy efficiency for ozone production was obtained using high voltage pulses of approximately 150 ns duration in Ar/O2 mixtures with the maximum efficiency (energy yield) of 23 g kW h-1 for 40% argon content.

Large discharge-volume, silent discharge spark plug

DOEpatents

Kang, Michael

1995-01-01

A large discharge-volume spark plug for providing self-limiting microdischarges. The apparatus includes a generally spark plug-shaped arrangement of a pair of electrodes, where either of the two coaxial electrodes is substantially shielded by a dielectric barrier from a direct discharge from the other electrode, the unshielded electrode and the dielectric barrier forming an annular volume in which self-terminating microdischarges occur when alternating high voltage is applied to the center electrode. The large area over which the discharges occur, and the large number of possible discharges within the period of an engine cycle, make the present silent discharge plasma spark plug suitable for use as an ignition source for engines. In the situation, where a single discharge is effective in causing ignition of the combustible gases, a conventional single-polarity, single-pulse, spark plug voltage supply may be used.

Newborn follow-up after discharge from a tertiary care hospital in the Western Cape region of South Africa: a prospective observational cohort study.

PubMed

Milambo, Jean Paul Muambangu; Cho, KaWing; Okwundu, Charles; Olowoyeye, Abiola; Ndayisaba, Leonidas; Chand, Sanjay; Corden, Mark H

2018-01-01

Current practice in the Western Cape region of South Africa is to discharge newborns born in-hospital within 24 h following uncomplicated vaginal delivery and two days after caesarean section. Mothers are instructed to bring their newborn to a clinic after discharge for a health assessment. We sought to determine the rate of newborn follow-up visits and the potential barriers to timely follow-up. Mother-newborn dyads at Tygerberg Hospital in Cape Town, South Africa were enrolled from November 2014 to April 2015. Demographic data were obtained via questionnaire and medical records. Mothers were contacted one week after discharge to determine if they had brought their newborns for a follow-up visit, and if not, the barriers to follow-up. Factors associated with follow-up were analyzed using logistic regression. Of 972 newborns, 794 (82%) were seen at a clinic for a follow-up visit within one week of discharge. Mothers with a higher education level or whose newborns were less than 37 weeks were more likely to follow up. The follow-up rate did not differ based on hospital length of stay. Main reported barriers to follow-up included maternal illness, lack of money for transportation, and mother felt follow-up was unnecessary because newborn was healthy. Nearly 4 in 5 newborns were seen at a clinic within one week after hospital discharge, in keeping with local practice guidelines. Further research on the outcomes of this population and those who fail to follow up is needed to determine the impact of postnatal healthcare policy.

Concentration-discharge relationships for variably sized streams in Florida: Patterns and drivers in long-term catchment studies

NASA Astrophysics Data System (ADS)

Diamond, J.; Cohen, M.

2012-12-01

Catchment-scale analyses can provide important insight into the processes governing solute sources, transport and storage. Understanding solute dynamics is vital for water management both for accurate predictions of chemical fluxes as well as ecosystem responses to them. This project synthesized long-term (>15 years) hydrochemical data from 80 variably sized (101-105 m2) watersheds in Florida. Our goal was to evaluate scaling effects on flow-solute relationships, and determine the factors that control observed inter-catchment variation. We obtained long term records of a variety of chemical parameters include color, nutrients (N and P), and geogenic solutes (Ca, Si, Mg, Na, Cl) from stations where chemistry and flow data were matched. Catchment attributes (land use, terrain, surface geology) were obtained for each stream as potential covariates. Concentration-discharge relationships were modeled as power functions, the exponents (b) of which were categorized into three end-member scenarios: (1) b>0, or chemodynamic conditions, where increased discharge increases concentration, (2) b=0, or chemostatic conditions, where concentration is independent of discharge, and (3) b<0, or dilution conditions, where increased discharge decreases concentrations. Color was strongly chemodynamic, while geogenic solutes tended to be chemostatic;nutrient-flow relationships varied substantially (from dilution to chemodynamic) suggesting important ancillary controls. To assess between-site variability, power function exponents were compared against land use and catchment area. These results indicate that watersheds dominated by urban land use exhibit stronger dilution effects for most solutes while watersheds dominated by agricultural land use were generally chemostatic particularly for nutrients. This synthesis approach to understanding controls on observed concentration-discharge relationships is crucial to understanding the dynamics and early-warning indicators of anthropogenically

The effect of a combined low-pressure gas discharge on metal surfaces

NASA Astrophysics Data System (ADS)

Brzhozovskii, B.; Brovkova, M.; Gestrin, S.; Martynov, V.; Zinina, E.

2018-04-01

The properties and effects of a combined gas discharge, obtained by superimposing ultrahigh-frequency electromagnetic and electrostatic fields on the surface of metal products, have been studied. Estimates for the main physical properties characterizing the discharge have been obtained. The paper shows that the properties of a combined discharge essentially depend on the sign of the constant electric potential of the workpiece. In the case of a positive potential, there is a substantial hardening of the metal surface layer. Blanket coating formation, which is a nanocomposite two-phase structure, has been recorded.

MHD modeling of a DIII-D low-torque QH-mode discharge and comparison to observations

DOE PAGES

King, Jacob R.; Kruger, S. E.; Burrell, K. H.; ...

2017-03-07

Extended-MHD modeling of DIII-D tokamak quiescent H-mode (QH-mode) discharges with nonlinear NIMROD simulations saturates into a turbulent state but does not saturate when the steady-state flow inferred from measurements is not included. This is consistent with the experimental observations of the quiescent regime on DIII-D. The simulation with flow develops into a saturated turbulent state where the n Φ = 1 and 2 toroidal modes become dominant through an inverse cascade. Each mode in the range of n Φ = 1–5 is dominant at a different time. Consistent with experimental observations during QH-mode, the simulated state leads to large particlemore » transport relative to the thermal transport. Analysis shows that the amplitude and phase of the density and temperature perturbations differ resulting in greater fluctuation-induced convective particle transport relative to the convective thermal transport. As a result, comparison to magnetic-coil measurements shows that rotation frequencies differ between the simulation and experiment, which indicates that more sophisticated extended-MHD two-fluid modeling is required.« less

MHD modeling of a DIII-D low-torque QH-mode discharge and comparison to observations

DOE Office of Scientific and Technical Information (OSTI.GOV)

King, Jacob R.; Kruger, S. E.; Burrell, K. H.

Extended-MHD modeling of DIII-D tokamak quiescent H-mode (QH-mode) discharges with nonlinear NIMROD simulations saturates into a turbulent state but does not saturate when the steady-state flow inferred from measurements is not included. This is consistent with the experimental observations of the quiescent regime on DIII-D. The simulation with flow develops into a saturated turbulent state where the n Φ = 1 and 2 toroidal modes become dominant through an inverse cascade. Each mode in the range of n Φ = 1–5 is dominant at a different time. Consistent with experimental observations during QH-mode, the simulated state leads to large particlemore » transport relative to the thermal transport. Analysis shows that the amplitude and phase of the density and temperature perturbations differ resulting in greater fluctuation-induced convective particle transport relative to the convective thermal transport. As a result, comparison to magnetic-coil measurements shows that rotation frequencies differ between the simulation and experiment, which indicates that more sophisticated extended-MHD two-fluid modeling is required.« less

Craniosynostosis repair - discharge

MedlinePlus

... a child's skull to grow together (fuse) too early. ... Craniectomy - child - discharge; Synostectomy - discharge; Strip craniectomy - discharge; Endoscopy-assisted craniectomy - discharge; Sagittal craniectomy - discharge; Frontal-orbital advancement - discharge; FOA - discharge

Radical prostatectomy - discharge

MedlinePlus

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

Particle-in-cell modeling of gas-confined barrier discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levko, Dmitry; Raja, Laxminarayan L.

2016-04-15

Gas-confined barrier discharge is studied using the one-dimensional Particle-in-Cell Monte Carlo Collisions model for the conditions reported by Guerra-Garcia and Martinez-Sanchez [Appl. Phys. Lett. 106, 041601 (2015)]. Depending on the applied voltage, two modes of discharge are observed. In the first mode, the discharge develops in the entire interelectrode gap. In the second mode, the discharge is ignited and develops only in the gas layer having smaller breakdown voltage. The one-dimensional model shows that for the conditions considered, there is no streamer stage of breakdown as is typical for a traditional dielectric barrier discharge.

Microwave Discharges

NASA Astrophysics Data System (ADS)

Marec, J.; Bloyet, E.; Chaker, M.; Leprince, P.; Nghiem, P.

Microwave discharges first appeared as unwanted and disturbing effects. However, beginning about the end of World War II, Professors Allis and Brown at the Massachusetts Institute of Technology started to investigate the physics of these discharges. During the next few years, many experimental and theoretical studies were undertaken. However, in the early 60's and for about 15 years, there were few studies of such discharges because of the theoretical difficulties encountered. Effectively, the impossibility of modeling microwave discharges prevented a good understanding of their behavior, and their future use did not appear promising. Recently there has been new interest in these discharges. The plasmas produced by microwave discharges find applications in areas such as: 1) spectroscopy (because of their low contamination), and 2) plasma chemistry. Another advantage of these discharges as compared to d.c. discharges is their ease of operation.

Discharge Oscillations in a Permanent Magnet Cylindrical Hall-Effect Thruster

NASA Technical Reports Server (NTRS)

Polzin, K. A.; Sooby, E. S.; Raitses, Y.; Merino, E.; Fisch, N. J.

2009-01-01

Measurements of the discharge current in a cylindrical Hall thruster are presented to quantify plasma oscillations and instabilities without introducing an intrusive probe into the plasma. The time-varying component of the discharge current is measured using a current monitor that possesses a wide frequency bandwidth and the signal is Fourier transformed to yield the frequency spectra present, allowing for the identification of plasma oscillations. The data show that the discharge current oscillations become generally greater in amplitude and complexity as the voltage is increased, and are reduced in severity with increasing flow rate. The breathing mode ionization instability is identified, with frequency as a function of discharge voltage not increasing with discharge voltage as has been observed in some traditional Hall thruster geometries, but instead following a scaling similar to a large-amplitude, nonlinear oscillation mode recently predicted in for annular Hall thrusters. A transition from lower amplitude oscillations to large relative fluctuations in the oscillating discharge current is observed at low flow rates and is suppressed as the mass flow rate is increased. A second set of peaks in the frequency spectra are observed at the highest propellant flow rate tested. Possible mechanisms that might give rise to these peaks include ionization instabilities and interactions between various oscillatory modes.

Oxygen discharge and post-discharge kinetics experiments and modeling for the electric oxygen-iodine laser system.

PubMed

Palla, A D; Zimmerman, J W; Woodard, B S; Carroll, D L; Verdeyen, J T; Lim, T C; Solomon, W C

2007-07-26

Laser oscillation at 1315 nm on the I(2P1/2)-->I(2P3/2) transition of atomic iodine has been obtained by a near resonant energy transfer from O2(a1Delta) produced using a low-pressure oxygen/helium/nitric oxide discharge. In the electric discharge oxygen-iodine laser (ElectricOIL) the discharge production of atomic oxygen, ozone, and other excited species adds levels of complexity to the singlet oxygen generator (SOG) kinetics which are not encountered in a classic purely chemical O2(a1Delta) generation system. The advanced model BLAZE-IV has been introduced to study the energy-transfer laser system dynamics and kinetics. Levels of singlet oxygen, oxygen atoms, and ozone are measured experimentally and compared with calculations. The new BLAZE-IV model is in reasonable agreement with O3, O atom, and gas temperature measurements but is under-predicting the increase in O2(a1Delta) concentration resulting from the presence of NO in the discharge and under-predicting the O2(b1Sigma) concentrations. A key conclusion is that the removal of oxygen atoms by NOX species leads to a significant increase in O2(a1Delta) concentrations downstream of the discharge in part via a recycling process; however, there are still some important processes related to the NOX discharge kinetics that are missing from the present modeling. Further, the removal of oxygen atoms dramatically inhibits the production of ozone in the downstream kinetics.

Analysis on the spectra and synchronous radiated electric field observation of cloud-to-ground lightning discharge plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cen Jianyong; Yuan Ping; Qu Haiyan

2011-11-15

According to the spectra of cloud-to-ground (CG) lightning discharge plasma captured by a slit-less spectrograph and the information of synchronous radiated electric field, the temperatures, the total intensity of spectra, the peak value of current and its action integral of discharge plasma channel have been calculated. Furthermore, the correlativity of these parameters has been analyzed for the first time. The results indicate that the total intensity of spectra has a positive correlation to the discharge current in different strokes of one CG lightning, and the temperature of discharge plasma is direct proportion to the action integral in the first returnmore » strokes of different lightning.« less

Discharge characteristics of embankment-shaped weirs

USGS Publications Warehouse

Kindsvater, Carl E.

1964-01-01

An embankment-shaped weir is an embankment overtopped by flood waters. Among the engineering problems frequently resulting from. this occurrence is the need to compute the peak discharge from postflood yield observations. The research described in this. report was concerned with the theoretical and experimental bases for the computation procedure. The research had two main objectives. One was to determine the relationship between embankment form and roughness and some of the more important discharge characteristics. The second was to define, theoretically and experimentally, the relationship between free-flow discharge and the boundary layer on the roadway. The first objective was accomplished with the experimental determination of coefficients of discharge and other significant flow characteristics for a variety of boundary and flow conditions. The second objective was accomplished with the development and experimental verification of a discharge equation which involved the boundary layer displacement thickness. This phase of the research included a general investigation of boundary layer growth on the roadway. It is included that both free- and submerged-flow discharge are virtually independent of the influence of embankment shape and relative height. The influence of boundary resistance is appreciable only for smaller heads. The most practical solution for discharge is one which is based on. the simple weir equation and experimentally determined coefficients. A completely analytical equation of discharge is impractical. The report contains the results of 936 experiments on the discharge characteristics of 17 different models; plus 106 boundary-layer velocity traverses on 4 different models. The data are summarized in both graphical and tabular form.

AC Glow Discharge Plasma in N2O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yousif, F. B.; Martinez, H.; Robledo-Martinez, A.

2006-12-04

This paper considers the optical and electrical characterization of AC glow discharge plasma in the abnormal glow mode used for optical emission spectroscopy. The total discharge current and applied voltage are measured using conventional techniques. The electrical characteristics of the planer-cathode glow discharge confirmed that the plasma is operating at abnormal discharge mode characterized by the increases in the operating voltage as the current was raised under given pressure. Optical emission spectroscopy was used to determine the main emission lines of the glow discharge plasma of N2O at pressures between 0.5 and 4.0 Torr. It shows that the discharge emissionmore » range is mainly within 300-400 nm. The emission lines correspond to NO, O2, and O{sub 2}{sup +} are the dominant lines in the glow discharge plasma in the present study. Intensity of the emission lines show linear increase with the discharge current up to 0.4 A followed by saturation at higher currents. No emission lines were observed in this work corresponding to atomic oxygen or nitrogen.« less

An experimental investigation of a hollow cathode discharge

NASA Technical Reports Server (NTRS)

Wilbur, P. J.

1971-01-01

An experimental study of the effects of various modifications to the hollow cathode discharge region of a 20 cm electron bombardment ion thruster is presented. The introduction of electrical insulation between the main and cathode discharge regions is shown to have no significant effect on thruster performance. Adjustment of both the diameter and length of the cathode discharge region from the design condition are examined and the reduced sizes are shown to effect large improvements in propellant utilization when the thruster is operating at about 30% of the design thrust level. Performance improvements are shown to be less significant at higher thrust levels. The feasibility of using a high voltage tickler electrode to initiate the cathode-keeper discharge is considered and results obtained suggest this mode of startup is unsatisfactory.

Shoulder replacement - discharge

MedlinePlus

Total shoulder arthroplasty - discharge; Endoprosthetic shoulder replacement - discharge; Partial shoulder replacement - discharge; Partial shoulder arthroplasty - discharge; Replacement - shoulder - discharge; Arthroplasty - shoulder - ...

Mode transition of a Hall thruster discharge plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hara, Kentaro, E-mail: kenhara@umich.edu; Sekerak, Michael J., E-mail: msekerak@umich.edu; Boyd, Iain D.

2014-05-28

A Hall thruster is a cross-field plasma device used for spacecraft propulsion. An important unresolved issue in the development of Hall thrusters concerns the effect of discharge oscillations in the range of 10–30 kHz on their performance. The use of a high speed Langmuir probe system and ultra-fast imaging of the discharge plasma of a Hall thruster suggests that the discharge oscillation mode, often called the breathing mode, is strongly correlated to an axial global ionization mode. Stabilization of the global oscillation mode is achieved as the magnetic field is increased and azimuthally rotating spokes are observed. A hybrid-direct kinetic simulationmore » that takes into account the transport of electronically excited atoms is used to model the discharge plasma of a Hall thruster. The predicted mode transition agrees with experiments in terms of the mean discharge current, the amplitude of discharge current oscillation, and the breathing mode frequency. It is observed that the stabilization of the global oscillation mode is associated with reduced electron transport that suppresses the ionization process inside the channel. As the Joule heating balances the other loss terms including the effects of wall loss and inelastic collisions, the ionization oscillation is damped, and the discharge oscillation stabilizes. A wide range of the stable operation is supported by the formation of a space charge saturated sheath that stabilizes the electron axial drift and balances the Joule heating as the magnetic field increases. Finally, it is indicated from the numerical results that there is a strong correlation between the emitted light intensity and the discharge current.« less

High-frequency underwater plasma discharge application in antibacterial activity

NASA Astrophysics Data System (ADS)

Ahmed, M. W.; Choi, S.; Lyakhov, K.; Shaislamov, U.; Mongre, R. K.; Jeong, D. K.; Suresh, R.; Lee, H. J.

2017-03-01

Plasma discharge is a novel disinfection and effectual inactivation approach to treat microorganisms in aqueous systems. Inactivation of Gram-negative Escherichia coli ( E. coli) by generating high-frequency, high-voltage, oxygen (O2) injected and hydrogen peroxide (H2O2) added discharge in water was achieved. The effect of H2O2 dose and oxygen injection rate on electrical characteristics of discharge and E. coli disinfection has been reported. Microbial log reduction dependent on H2O2 addition with O2 injection was observed. The time variation of the inactivation efficiency quantified by the log reduction of the initial E. coli population on the basis of optical density measurement was reported. The analysis of emission spectrum recorded after discharge occurrence illustrated the formation of oxidant species (OH•, H, and O). Interestingly, the results demonstrated that O2 injected and H2O2 added, underwater plasma discharge had fabulous impact on the E. coli sterilization. The oxygen injection notably reduced the voltage needed for generating breakdown in flowing water and escalated the power of discharge pulses. No impact of hydrogen peroxide addition on breakdown voltage was observed. A significant role of oxidant species in bacterial inactivation also has been identified. Furthermore the E. coli survivability in plasma treated water with oxygen injection and hydrogen peroxide addition drastically reduced to zero. The time course study also showed that the retardant effect on E. coli colony multiplication in plasma treated water was favorable, observed after long time. High-frequency underwater plasma discharge based biological applications is technically relevant and would act as baseline data for the development of novel antibacterial processing strategies.

Characterization of the supersonic flowing microwave discharge using two dimensional plasma tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nikolic, M.; Samolov, A.; Popovic, S.

2013-03-14

A tomographic numerical method based on the two-dimensional Radon formula for a cylindrical cavity has been employed for obtaining spatial distributions of the argon excited levels. The spectroscopy measurements were taken at different positions and directions to observe populations of excited species in the plasmoid region and the corresponding excitation temperatures. Excited argon states are concentrated near the tube walls, thus, confirming the assumption that the post discharge plasma is dominantly sustained by travelling surface wave. An automated optical measurement system has been developed for reconstruction of local plasma parameters of the plasmoid structure formed in an argon supersonic flowingmore » microwave discharge. The system carries out angle and distance measurements using a rotating, flat mirror, as well as two high precision stepper motors operated by a microcontroller-based system and several sensors for precise feedback control.« less

The evolution of discharge current and channel radius in cloud-to-ground lightning return stroke process

NASA Astrophysics Data System (ADS)

Fan, Tingting; Yuan, Ping; Wang, Xuejuan; Cen, Jianyong; Chang, Xuan; Zhao, Yanyan

2017-09-01

The spectra of two negative cloud-to-ground lightning discharge processes with multi-return strokes are obtained by a slit-less high-speed spectrograph, which the temporal resolution is 110 μs. Combined with the synchronous electrical observation data and theoretical calculation, the physical characteristics during return strokes process are analysed. A positive correlation between discharge current and intensity of ionic lines in the spectra is verified, and based on this feature, the current evolution characteristics during four return strokes are investigated. The results show that the time from peak current to the half-peak value estimated by multi point-fitting is about 101 μs-139 μs. The Joule heat in per unit length of four return strokes channel is in the order of 105J/m-106 J/m. The radius of arc discharge channel is positively related to the discharge current, and the more intense the current is, the greater the radius of channel is. Furthermore, the evolution for radius of arc core channel in the process of return stroke is consistent with the change trend of discharge current after the peak value. Compared with the decay of the current, the temperature decreases more slowly.

High-k shallow traps observed by charge pumping with varying discharging times

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Szu-Han; Chen, Ching-En; Tseng, Tseung-Yuen

2013-11-07

In this paper, we investigate the influence of falling time and base level time on high-k bulk shallow traps measured by charge pumping technique in n-channel metal-oxide-semiconductor field-effect transistors with HfO{sub 2}/metal gate stacks. N{sub T}-V{sub high} {sub level} characteristic curves with different duty ratios indicate that the electron detrapping time dominates the value of N{sub T} for extra contribution of I{sub cp} traps. N{sub T} is the number of traps, and I{sub cp} is charge pumping current. By fitting discharge formula at different temperatures, the results show that extra contribution of I{sub cp} traps at high voltage are inmore » fact high-k bulk shallow traps. This is also verified through a comparison of different interlayer thicknesses and different Ti{sub x}N{sub 1−x} metal gate concentrations. Next, N{sub T}-V{sub high} {sub level} characteristic curves with different falling times (t{sub falling} {sub time}) and base level times (t{sub base} {sub level}) show that extra contribution of I{sub cp} traps decrease with an increase in t{sub falling} {sub time}. By fitting discharge formula for different t{sub falling} {sub time}, the results show that electrons trapped in high-k bulk shallow traps first discharge to the channel and then to source and drain during t{sub falling} {sub time}. This current cannot be measured by the charge pumping technique. Subsequent measurements of N{sub T} by charge pumping technique at t{sub base} {sub level} reveal a remainder of electrons trapped in high-k bulk shallow traps.« less

Clostridium beijerinckii mutant obtained atmospheric pressure glow discharge generates enhanced electricity in a microbial fuel cell.

PubMed

Liu, Jun; Guo, Ting; Wang, Dong; Ying, Hanjie

2015-01-01

A Clostridium beijerinckii mutant M13 was derived from C. beijerinckii NCIMB 8052 by atmospheric pressure glow discharge. C. beijerinckii M13 generated a maximum output power density of 79.2 mW m(-2) and a maximum output voltage of 230 mV in a microbial fuel cell containing 1 g glucose l(-1) as carbon source and 0.15 g methyl viologen l(-1) as an electron carrier.

Determination of the plasma impedance of a glow discharge in carbon dioxide

NASA Astrophysics Data System (ADS)

Kiselev, A. S.; Smirnov, E. A.

2017-07-01

In this work an expression for the dynamic resistance of a glow discharge flowing in long tubes is obtained and analyzed. The expression describes the physical processes occurring in the positive column of a glow discharge. The frequency dependences of the active and reactive components as well as the dynamic resistance module for the discharge conditions corresponding to CO2-lasers have been calculated. Based on the simulation results developed a computer program in the C# programming language for modeling the dynamic resistance discharge of glow discharge lasers.

High Power ECR Ion Thruster Discharge Characterization

NASA Technical Reports Server (NTRS)

Foster, John E.; Kamhawi, Hani; Haag, Thomas; Carpenter, Christian; Williams, George W.

2006-01-01

Electron cyclotron resonance (ECR) based ion thrusters with carbon based ion optics can potentially satisfy lifetime requirements for long duration missions (approximately 10 years) because grid erosion and cathode insert depletion issues are virtually eliminated. Though the ECR plasma discharge has been found to typically operate at slightly higher discharge losses than conventional DC ion thrusters (for high total thruster power applications), the discharge power fraction is small (less than 1 percent at 25 kW). In this regard, the benefits of increased life, low discharge plasma potentials, and reduced complexity are welcome tradeoffs for the associated discharge efficiency decrease. Presented here are results from discharge characterization of a large area ECR plasma source for gridded ion thruster applications. These measurements included load matching efficacy, bulk plasma properties via Langmuir probe, and plasma uniformity as measured using current probes distributed at the exit plane. A high degree of plasma uniformity was observed (flatness greater than 0.9). Additionally, charge state composition was qualitatively evaluated using emission spectroscopy. Plasma induced emission was dominated by xenon ion lines. No doubly charged xenon ions were detected.

Satellite-Based Estimation of Water Discharge and Runoff in the Magdalena River, Northern Andes of Colombia

NASA Astrophysics Data System (ADS)

Restrepo, J. D.; Escobar Correa, R.; Kettner, A.; Brakenridge, G. R.

2016-12-01

The Magdalena River and its most important tributary, the Cauca, drain the northern Andes of Colombia. During the wet season, flood events affect the whole region and cause huge damage in low-income communities. Mitigation of such natural disasters in Colombia lacks science-supported tools for evaluating river response to extreme climate events. Here we introduce near-real-time estimations of river discharge towards technical capacity building for evaluation of flood magnitudes and variability along the Magdalena and Cauca. We use the River Watch version 3 system of the Dartmouth Flood Observatory (DFO) at five selected measurement sites on the two rivers. For each site, two different rating curves were constructed to transform microwave signal from TRMM, AMSR-E, AMRS-2, and GPM satellites into river discharge. The first rating curves were based on numerical discharge estimates from a global Water Balance Model (WBM); the second were obtained from the relationship between satellite signal and measured river discharge at ground gauging stations at nearby locations. Determination coefficients (R2) between observed versus satellite-derived daily discharge data, range from 0.38 to 0.57 in the upper basin, whereas in the middle of the basin R2 values vary between 0.47 and 0.64. In the lower basin, observed R2 values are lower and range from 0.32 to 0.4. Once time lags between the microwave satellite signal and river discharge from either WBM estimates or ground-based gauging stations are taken into account, the R2 values increase considerably. The time series of satellite-based river discharge during the 1998 - 2016 period show high inter-annual variability as well as strong pulses associated with the ENSO (La Niña/El Niño) cycle. Numerical runoff magnitude estimates at peaks of extreme climatic anomalies are more correlated than stream flows measured at ground-based gauging stations. In fluvial systems such as the Magdalena, characterized by high spatial variability

Development of a Lumped Element Circuit Model for Approximation of Dielectric Barrier Discharges

DTIC Science & Technology

2011-08-01

dielectric barrier discharge (DBD) plasmas. Based on experimental observations, it is assumed that nanosecond pulsed DBDs, which have been proposed...species for pulsed direct current (DC) dielectric barrier discharge (DBD) plasmas. Based on experimental observations, it is assumed that nanosecond...momentum-based approaches. Given the fundamental differences between the novel pulsed discharge approach and the more conventional momentum-based

Visualization by discharge illumination technique and modification by plasma actuator of rarefied Mach 2 airflow around a cylinder

NASA Astrophysics Data System (ADS)

Leger, L.; Sellam, M.; Barbosa, E.; Depussay, E.

2013-06-01

The use of plasma actuators for flow control has received considerable attention in recent years. This kind of device seems to be an appropriate means of raising abilities in flow control thanks to total electric control, no moving parts and a fast response time. The experimental work presented here shows, firstly, the non-intrusive character of the visualization of the density field of an airflow around a cylinder obtained using a plasma luminescence technique. Experiments are made in a continuous supersonic wind tunnel. The static pressure in the flow is 8 Pa, the mean free path is about 0.3 mm and the airflow velocity is 510 m s-1. Pressure measurements obtained by means of glass Pitot tube without the visualization discharge are proposed. Measured and simulated pressure profiles are in good agreement in the region near the cylinder. There is good correlation between numerical simulations of the supersonic flow field, analytical model predictions and experimental flow visualizations obtained by a plasma luminescence technique. Consequently, we show that the plasma luminescence technique is non-intrusive. Secondly, the effect of a dc discharge on a supersonic rarefied air flow around a cylinder is studied. An electrode is flush mounted on the cylinder. Stagnation pressure profiles are examined for different electrode positions on the cylinder. A shock wave modification depending on the electrode location is observed. The discharge placed at the upstream stagnation point induces an upstream shift of the bow shock, whereas a modification of the shock wave shape is observed when it is placed at 45° or 90°.

Post-breakdown secondary discharges at the electrode/dielectric interface of a cylindrical barrier discharge

NASA Astrophysics Data System (ADS)

Carman, Robert; Ward, Barry; Kane, Deborah

2011-10-01

The electrical breakdown characteristics of a double-walled cylindrical dielectric barrier discharge (DBD) lamp with a neon buffer gas under pulsed voltage excitation have been investigated. Following the formation of plasma in the main discharge gap, we have observed secondary breakdown phenomena at the inner and outer mesh electrode/dielectric interfaces under specific operating conditions. Plasma formation at these interfaces is investigated by monitoring the Ozone production rate in controlled flows of ultra high purity oxygen together with the overall electrical voltage-charge characteristics of the lamp. The results show that this secondary breakdown only occurs after the main discharge plasma has been established, and that significant electrical power may be dissipated in generating these spurious secondary plasmas. The results are important with regards to optimising the design and identifying efficient operating regimes of DBD based devices that employ mesh-type or wire/strip electrodes.

Alternating current corona discharge/atmospheric pressure chemical ionization for mass spectrometry.

PubMed

Habib, Ahsan; Usmanov, Dilshadbek; Ninomiya, Satoshi; Chen, Lee Chuin; Hiraoka, Kenzo

2013-12-30

Although alternating current (ac) corona discharge has been widely used in the fields of material science and technology, no reports have been published on its application to an atmospheric pressure chemical ionization (APCI) ion source. In this work, ac corona discharge for an APCI ion source has been examined for the first time. The ambient atmospheric pressure ac corona discharge (15 kHz, 2.6 kVptp ) was generated by using a stainless steel acupuncture needle. The generated ions were measured using an ion trap mass spectrometer. A comparative study on ac and direct current (dc) corona APCI ion sources was carried out using triacetone triperoxide and trinitrotoluene as test samples. The ac corona discharge gave ion signals as strong as dc corona discharge for both positive and negative ion modes. In addition, softer ionization was obtained with ac corona discharge than with dc corona discharge. The erosion of the needle tip induced by ac corona was less than that obtained with positive mode dc corona. A good 'yardstick' for assessing ac corona is that it can be used for both positive and negative ion modes without changing the polarity of the high-voltage power supply. Thus, ac corona can be an alternative to conventional dc corona for APCI ion sources. Copyright © 2013 John Wiley & Sons, Ltd.

Characterization of millimetre magnitude atmospheric pressure streamer discharge in pin-to-plane dielectric barrier discharge

NASA Astrophysics Data System (ADS)

Xu, S. J.; Zhang, Y. H.; Yu, Z.; Yao, J.; Zhang, Z. T.

2013-03-01

The streamer regime of pin-to-plane dielectric barrier discharge in air was studied by means of fast photography, electrical measurement and photoelectricity. The fast photographs of positive streamer were obtained by CCD camera with micro lens. The exposure time is one microseconds. The images illustrate that the streamer is non-axisymmetric because of some random factors, such as surface charge position, space charge distribution, gas liquidity and so on. In fact, the streamer propagates along bend discharge channel. The bending degree increases with the electric field strengthen. By surveying a mass of images, the diameter of streamer, height of surface charge effect and scope of surface charge was estimate used to describe the shape of streamer.

Facilitating emergency hospital evacuation through uniform discharge criteria.

PubMed

Sandra, Keret; Meital, Nahari; Ofer, Merin; Limor, Aharonson-Daniel; Sara, Goldberg; Bruria, Adini

2017-05-01

Though hospitals' operational continuity is crucial, full institutional evacuation may at times be unavoidable. The study's objective was to establish criteria for discharge of patients during complete emergency evacuation and compare scope of patients suitable for discharge pre/post implementation of criteria. Standards for patient discharge during an evacuation were developed based on literature and disaster managers. The standards were reviewed in a two-round Delphi process. All hospitals in Israel were requested to identify inpatients' that could be released home during institutional evacuation. Potential discharges were compared in 2013-2014, before and after formulation of discharge criteria. Consensus exceeding 80% was obtained for four out of five criteria after two Delphi cycles. Average projected discharge rate before and after formulation of criteria was 34.2% and 42.9%, respectively (p<0.001). Variance in potential dischargeable patients was 31-fold less in 2014 than in 2013 (MST=8,452 versus MST=264,366, respectively; p<0.001). Differences were found between small, medium and large hospitals in mean rate of dischargeable patients: 52.1%, 41.5% and 42.2%, respectively (p=0.001). The study's findings enable to forecast the extent of patients that may be released home during full emergency evacuation of a hospital; thereby facilitating preparedness of contingency plans. Copyright © 2016 Elsevier Inc. All rights reserved.

Sensitive glow discharge ion source for aerosol and gas analysis

DOEpatents

Reilly, Peter T. A. [Knoxville, TN

2007-08-14

A high sensitivity glow discharge ion source system for analyzing particles includes an aerodynamic lens having a plurality of constrictions for receiving an aerosol including at least one analyte particle in a carrier gas and focusing the analyte particles into a collimated particle beam. A separator separates the carrier gas from the analyte particle beam, wherein the analyte particle beam or vapors derived from the analyte particle beam are selectively transmitted out of from the separator. A glow discharge ionization source includes a discharge chamber having an entrance orifice for receiving the analyte particle beam or analyte vapors, and a target electrode and discharge electrode therein. An electric field applied between the target electrode and discharge electrode generates an analyte ion stream from the analyte vapors, which is directed out of the discharge chamber through an exit orifice, such as to a mass spectrometer. High analyte sensitivity is obtained by pumping the discharge chamber exclusively through the exit orifice and the entrance orifice.

MHD modeling of a DIII-D low-torque QH-mode discharge and comparison to observations

NASA Astrophysics Data System (ADS)

King, J. R.; Kruger, S. E.; Burrell, K. H.; Chen, X.; Garofalo, A. M.; Groebner, R. J.; Olofsson, K. E. J.; Pankin, A. Y.; Snyder, P. B.

2017-05-01

Extended-MHD modeling of DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] quiescent H-mode (QH-mode) discharges with nonlinear NIMROD [C. R. Sovinec et al., J. Comput. Phys. 195, 355 (2004)] simulations saturates into a turbulent state but does not saturate when the steady-state flow inferred from measurements is not included. This is consistent with the experimental observations of the quiescent regime on DIII-D. The simulation with flow develops into a saturated turbulent state where the nϕ=1 and 2 toroidal modes become dominant through an inverse cascade. Each mode in the range of nϕ=1 -5 is dominant at a different time. Consistent with experimental observations during QH-mode, the simulated state leads to large particle transport relative to the thermal transport. Analysis shows that the amplitude and phase of the density and temperature perturbations differ resulting in greater fluctuation-induced convective particle transport relative to the convective thermal transport. Comparison to magnetic-coil measurements shows that rotation frequencies differ between the simulation and experiment, which indicates that more sophisticated extended-MHD two-fluid modeling is required.

Cathode fall measurement in a dielectric barrier discharge in helium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hao, Yanpeng; Zheng, Bin; Liu, Yaoge

2013-11-15

A method based on the “zero-length voltage” extrapolation is proposed to measure cathode fall in a dielectric barrier discharge. Starting, stable, and discharge-maintaining voltages were measured to obtain the extrapolation zero-length voltage. Under our experimental conditions, the “zero-length voltage” gave a cathode fall of about 185 V. Based on the known thickness of the cathode fall region, the spatial distribution of the electric field strength in dielectric barrier discharge in atmospheric helium is determined. The strong cathode fall with a maximum field value of approximately 9.25 kV/cm was typical for the glow mode of the discharge.

Linear error analysis of slope-area discharge determinations

USGS Publications Warehouse

Kirby, W.H.

1987-01-01

The slope-area method can be used to calculate peak flood discharges when current-meter measurements are not possible. This calculation depends on several quantities, such as water-surface fall, that are subject to large measurement errors. Other critical quantities, such as Manning's n, are not even amenable to direct measurement but can only be estimated. Finally, scour and fill may cause gross discrepancies between the observed condition of the channel and the hydraulic conditions during the flood peak. The effects of these potential errors on the accuracy of the computed discharge have been estimated by statistical error analysis using a Taylor-series approximation of the discharge formula and the well-known formula for the variance of a sum of correlated random variates. The resultant error variance of the computed discharge is a weighted sum of covariances of the various observational errors. The weights depend on the hydraulic and geometric configuration of the channel. The mathematical analysis confirms the rule of thumb that relative errors in computed discharge increase rapidly when velocity heads exceed the water-surface fall, when the flow field is expanding and when lateral velocity variation (alpha) is large. It also confirms the extreme importance of accurately assessing the presence of scour or fill. ?? 1987.

Application of Bayesian geostatistics for evaluation of mass discharge uncertainty at contaminated sites

NASA Astrophysics Data System (ADS)

Troldborg, Mads; Nowak, Wolfgang; Lange, Ida V.; Santos, Marta C.; Binning, Philip J.; Bjerg, Poul L.

2012-09-01

Mass discharge estimates are increasingly being used when assessing risks of groundwater contamination and designing remedial systems at contaminated sites. Such estimates are, however, rather uncertain as they integrate uncertain spatial distributions of both concentration and groundwater flow. Here a geostatistical simulation method for quantifying the uncertainty of the mass discharge across a multilevel control plane is presented. The method accounts for (1) heterogeneity of both the flow field and the concentration distribution through Bayesian geostatistics, (2) measurement uncertainty, and (3) uncertain source zone and transport parameters. The method generates conditional realizations of the spatial flow and concentration distribution. An analytical macrodispersive transport solution is employed to simulate the mean concentration distribution, and a geostatistical model of the Box-Cox transformed concentration data is used to simulate observed deviations from this mean solution. By combining the flow and concentration realizations, a mass discharge probability distribution is obtained. The method has the advantage of avoiding the heavy computational burden of three-dimensional numerical flow and transport simulation coupled with geostatistical inversion. It may therefore be of practical relevance to practitioners compared to existing methods that are either too simple or computationally demanding. The method is demonstrated on a field site contaminated with chlorinated ethenes. For this site, we show that including a physically meaningful concentration trend and the cosimulation of hydraulic conductivity and hydraulic gradient across the transect helps constrain the mass discharge uncertainty. The number of sampling points required for accurate mass discharge estimation and the relative influence of different data types on mass discharge uncertainty is discussed.

Effect of cardiologist care on 6-month outcomes in patients discharged with heart failure: results from an observational study based on administrative data

PubMed Central

Avaldi, Vera Maria; Urbinati, Stefano; Molinazzi, Dario; Descovich, Carlo; Campagna, Anselmo; Taglioni, Martina; Fioritti, Angelo

2017-01-01

Objectives To evaluate the effect of cardiologist care on adherence to evidence-based secondary prevention medications, mortality and readmission within 6 months of discharge in patients with heart failure (HF). Design Retrospective observational study based on administrative data. Setting Local Healthcare Authority (LHA) of Bologna, one of the largest LHAs of Italy with ~870 000 inhabitants. Participants All patients residing in the LHA of Bologna discharged from hospital with a diagnosis of HF between 1 January 2015 and 31 December 2015. Primary and secondary outcome measures Multivariable regression analysis was used to assess the association of inpatient and outpatient cardiologist care with adherence to evidence-based medications, all-cause mortality and hospital readmission (including emergency room visits) within 6 months of discharge. Results The study population included 2650 patients (mean age 82.3 years). 340 (12.8%) patients were discharged from cardiology wards, while 635 (24.0%) were seen by a cardiologist during follow-up. Inpatient and outpatient cardiologist care was associated with an increased likelihood of adherence to ACE inhibitors/angiotensin receptor blockers (ACEIs/ARBs), β-blockers and aldosterone antagonists after discharge. The risk of mortality was significantly lower among patients adherent to ACEIs/ARBs and/or β-blockers (–53% and –28%, respectively); the risk of hospital readmission was significantly lower among patients adherent to ACEIs/ARBs (–28%). Conclusions Compared with non-specialist care, cardiologist care improves patient adherence to evidence-based medications and might thus favourably affect mortality and readmission following HF. PMID:29101146

High-frequency underwater plasma discharge application in antibacterial activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, M. W.; Choi, S.; Lyakhov, K.

Plasma discharge is a novel disinfection and effectual inactivation approach to treat microorganisms in aqueous systems. Inactivation of Gram-negative Escherichia coli (E. coli) by generating high-frequency, high-voltage, oxygen (O{sub 2}) injected and hydrogen peroxide (H{sub 2}O{sub 2}) added discharge in water was achieved. The effect of H{sub 2}O{sub 2} dose and oxygen injection rate on electrical characteristics of discharge and E. coli disinfection has been reported. Microbial log reduction dependent on H{sub 2}O{sub 2} addition with O{sub 2} injection was observed. The time variation of the inactivation efficiency quantified by the log reduction of the initial E. coli population onmore » the basis of optical density measurement was reported. The analysis of emission spectrum recorded after discharge occurrence illustrated the formation of oxidant species (OH{sup •}, H, and O). Interestingly, the results demonstrated that O{sub 2} injected and H{sub 2}O{sub 2} added, underwater plasma discharge had fabulous impact on the E. coli sterilization. The oxygen injection notably reduced the voltage needed for generating breakdown in flowing water and escalated the power of discharge pulses. No impact of hydrogen peroxide addition on breakdown voltage was observed. A significant role of oxidant species in bacterial inactivation also has been identified. Furthermore the E. coli survivability in plasma treated water with oxygen injection and hydrogen peroxide addition drastically reduced to zero. The time course study also showed that the retardant effect on E. coli colony multiplication in plasma treated water was favorable, observed after long time. High-frequency underwater plasma discharge based biological applications is technically relevant and would act as baseline data for the development of novel antibacterial processing strategies.« less

An Apparatus for Measuring Rates of Discharge of a Fuel-Injection System

NASA Technical Reports Server (NTRS)

Dutee, Francis J

1941-01-01

A portable apparatus for rapidly determining rates of discharge of a fuel-injection system is described. Satisfactory operation of this apparatus with injection-pump speeds up to 2400 r.p.m was obtained. Rate-of-discharge tests were made with several cam-plunger-valve injection systems with long injection tubes. A check valve designed to reduce secondary discharges was tested. This check valve was operated with injection-pump speeds up to 2400 r.p.m without the occurrence of large secondary discharges.

Low-pressure electrical discharge experiment to simulate high-altitude lightning above thunderclouds

NASA Technical Reports Server (NTRS)

Jarzembski, M. A.; Srivastava, V.

1995-01-01

Recently, extremely interesting high-altitude cloud-ionosphere electrical discharges, like lightning above thunderstorms, have been observed from NASA's space shuttle missions and during airborne and ground-based experiments. To understand these discharges, a new experiment was conceived to simulate a thundercloud in a vacuum chamber using a dielectric in particulate form into which electrodes were inserted to create charge centers analogous to those in an electrified cloud. To represent the ionosphere, a conducting medium (metallic plate) was introduced at the top of the chamber. It was found that for different pressures between approximately 1 and 300 mb, corresponding to various upper atmospheric altitudes, different discharges occurred above the simulated thundercloud, and these bore a remarkable similarity to the observed atmospheric phenomena. At pressures greater than 300 mb, these discharges were rare and only discharges within the simulated thundercloud were observed. Use of a particulate dielectric was critical for the successful simulation of the high-altitude lightning.

The measurement of argon metastable atoms in the barrier discharge plasma

NASA Astrophysics Data System (ADS)

Ghildina, Anna R.; Mikheyev, Pavel Anatolyevich; Chernyshov, Aleksandr Konstantinovich; Lunev, Nikolai Nikolaevich; Azyazov, Valeriy Nikolaevich

2018-04-01

The mandatory condition for efficient operation of an optically-pumped all-rare-gas laser (OPRGL) is the presence of rare gas metastable atoms in the discharge plasma with number density of the order of 1012-1013 cm-3. This requirement mainly depends on the choice of a discharge system. In this study the number density values of argon metastable atoms were obtained in the condition of the dielectric-barrier discharge (DBD) at an atmospheric pressure.

2-dimensional simulations of electrically asymmetric capacitively coupled RF-discharges

NASA Astrophysics Data System (ADS)

Mohr, Sebastian; Schulze, Julian; Schuengel, Edmund; Czarnetzki, Uwe

2011-10-01

Capactively coupled RF-discharges are widely used for surface treatment like the deposition of thin films. For industrial applications, the independent control of the ion flux to and the mean energy of the electrons impinging on the surfaces is desired. Experiments and 1D3v-PIC/MCC-simulations have shown that this independent control is possible by applying a fundamental frequency and its second harmonic to the powered electrode. This way, even in geometrically symmetric discharges, as they are often used in industrial reactors, a discharge asymmetry can be induced electrically, hence the name Electrical Asymmetry Effect (EAE). We performed 2D-simulations of electrically asymmetric discharges using HPEM by the group of Mark Kushner, a simulation tool suitable for simulating industrial reactors. First results are presented and compared to previously obtained experimental and simulation data. The comparison shows that for the first time, we succeeded in simulating electrically asymmetric discharges with a 2-dimensional simulation. Capactively coupled RF-discharges are widely used for surface treatment like the deposition of thin films. For industrial applications, the independent control of the ion flux to and the mean energy of the electrons impinging on the surfaces is desired. Experiments and 1D3v-PIC/MCC-simulations have shown that this independent control is possible by applying a fundamental frequency and its second harmonic to the powered electrode. This way, even in geometrically symmetric discharges, as they are often used in industrial reactors, a discharge asymmetry can be induced electrically, hence the name Electrical Asymmetry Effect (EAE). We performed 2D-simulations of electrically asymmetric discharges using HPEM by the group of Mark Kushner, a simulation tool suitable for simulating industrial reactors. First results are presented and compared to previously obtained experimental and simulation data. The comparison shows that for the first time, we

X-ray Production in a Laboratory Streamer Discharge

NASA Astrophysics Data System (ADS)

Lehtinen, N. G.; Kochkin, P.; Ostgaard, N.

2016-12-01

A 1D model of a 1-m scale laboratory discharge streamer system [Lehtinen et al, 2016, http://meetingorganizer.copernicus.org/EGU2016/EGU2016-6180.pdf] has reproduced the experimentally-observed [Kochkin et al, 2014, doi:10.1088/0022-3727/47/14/145203] detached streamer systems (pilots). The pilots grow in both directions and thus produce counter-streamers which collide with forward-moving streamers, a mechanism which was proposed to lead to the production of x-rays [Cooray, 2009, doi:10.1016/j.jastp.2009.07.010]. However, the 1D model is insufficient to analyse this process because in this model the electric field between the colliding streamers is averaged in the transverse direction and therefore the maximum fields are underestimated. In this presentation, we include the microscopic processes in the modeling of streamer propagation in order to calculate accurately the electric field enhancement between colliding streamers of opposite polarity. We evaluate the temporal and spatial characteristics of the enhanced electric field, which define the production of relativistic runaway electrons and x-rays. The x-ray output for the conditions occuring in a laboratory discharge is compared to the experimental data [Kochkin et al, 2012, doi:10.1088/0022-3727/45/42/425202; 2015, doi:10.1088/0022-3727/48/2/025205]. We note that the previous modeling of streamer collisions [Ihaddadene and Celestin, 2015, doi:10.1002/2015GL064623] obtained the field enhancements which are insufficient for the observed x-ray production.

Changes in the physical activity of acute stroke survivors between inpatient and community living with early supported discharge: an observational cohort study.

PubMed

Kerr, A; Rowe, P; Esson, D; Barber, M

2016-12-01

To describe and compare patterns of physical activity among stroke survivors during their hospital stay and community living with early supported discharge. Observational cohort study of physical activity before and after early supported discharge. UK National Health Service stroke units and participants' homes. Forty-one stroke survivors with a mean age of 69 (standard deviation 11) years, and a median Modified Rivermead Mobility Index of 33.5 [interquartile range (IQR) 25.8 to 35.3]. The primary outcome measures were time spent in sitting/standing/walking and number of steps taken, as recorded by a physical activity monitor. There were statistical differences (P<0.001) for all categories of physical activity. After early supported discharge to the community, participants took more than twice the number of steps {median 474 (IQR 189 to 773) vs. 1193 (IQR 512 to 2856), median difference 636 [95% confidence interval (CI) 262 to 931]} and spent more than double the time in standing [median 51 (IQR 22 to 128) minutes vs. 100 (IQR 51 to 178) minutes, median difference 28 (95% CI 11 to 68)] compared with their hospital stay. Community living with early supported discharge promoted higher levels of physical activity in medically stable stroke survivors. The near-doubling of activity may serve as a guideline for what is achievable during stroke rehabilitation. Number UKCRN 15472. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

State-space prediction of spring discharge in a karst catchment in southwest China

NASA Astrophysics Data System (ADS)

Li, Zhenwei; Xu, Xianli; Liu, Meixian; Li, Xuezhang; Zhang, Rongfei; Wang, Kelin; Xu, Chaohao

2017-06-01

Southwest China represents one of the largest continuous karst regions in the world. It is estimated that around 1.7 million people are heavily dependent on water derived from karst springs in southwest China. However, there is a limited amount of water supply in this region. Moreover, there is not enough information on temporal patterns of spring discharge in the area. In this context, it is essential to accurately predict spring discharge, as well as understand karst hydrological processes in a thorough manner, so that water shortages in this area could be predicted and managed efficiently. The objectives of this study were to determine the primary factors that govern spring discharge patterns and to develop a state-space model to predict spring discharge. Spring discharge, precipitation (PT), relative humidity (RD), water temperature (WD), and electrical conductivity (EC) were the variables analyzed in the present work, and they were monitored at two different locations (referred to as karst springs A and B, respectively, in this paper) in a karst catchment area in southwest China from May to November 2015. Results showed that a state-space model using any combinations of variables outperformed a classical linear regression, a back-propagation artificial neural network model, and a least square support vector machine in modeling spring discharge time series for karst spring A. The best state-space model was obtained by using PT and RD, which accounted for 99.9% of the total variation in spring discharge. This model was then applied to an independent data set obtained from karst spring B, and it provided accurate spring discharge estimates. Therefore, state-space modeling was a useful tool for predicting spring discharge in karst regions in southwest China, and this modeling procedure may help researchers to obtain accurate results in other karst regions.

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 ...

Use of radars to monitor stream discharge by noncontact methods

USGS Publications Warehouse

Costa, J.E.; Cheng, R.T.; Haeni, F.P.; Melcher, N.; Spicer, K.R.; Hayes, E.; Plant, W.; Hayes, K.; Teague, C.; Barrick, D.

2006-01-01

Conventional measurements of river flows are costly, time‐consuming, and frequently dangerous. This report evaluates the use of a continuous wave microwave radar, a monostatic UHF Doppler radar, a pulsed Doppler microwave radar, and a ground‐penetrating radar to measure river flows continuously over long periods and without touching the water with any instruments. The experiments duplicate the flow records from conventional stream gauging stations on the San Joaquin River in California and the Cowlitz River in Washington. The purpose of the experiments was to directly measure the parameters necessary to compute flow: surface velocity (converted to mean velocity) and cross‐sectional area, thereby avoiding the uncertainty, complexity, and cost of maintaining rating curves. River channel cross sections were measured by ground‐penetrating radar suspended above the river. River surface water velocity was obtained by Bragg scattering of microwave and UHF Doppler radars, and the surface velocity data were converted to mean velocity on the basis of detailed velocity profiles measured by current meters and hydroacoustic instruments. Experiments using these radars to acquire a continuous record of flow were conducted for 4 weeks on the San Joaquin River and for 16 weeks on the Cowlitz River. At the San Joaquin River the radar noncontact measurements produced discharges more than 20% higher than the other independent measurements in the early part of the experiment. After the first 3 days, the noncontact radar discharge measurements were within 5% of the rating values. On the Cowlitz River at Castle Rock, correlation coefficients between the USGS stream gauging station rating curve discharge and discharge computed from three different Doppler radar systems and GPR data over the 16 week experiment were 0.883, 0.969, and 0.992. Noncontact radar results were within a few percent of discharge values obtained by gauging station, current meter, and hydroacoustic methods

Neutral gas rotation in magnetron discharge

NASA Astrophysics Data System (ADS)

Pal, A. F.; Ryabinkin, A. N.; Serov, A. O.; Filippov, A. V.

2014-12-01

We have experimentally established the existence and determined the velocity of motion of the neutral component of plasma in a planar magnetron discharge, which takes place in the direction of drift of the charged plasma component in crossed electric and magnetic ( E × B) fields. For this purpose, we have studied the propagation of a small gaseous additive over the plasma ring of dc magnetron discharge in the diffusion regime. The obtained temporal dependences of the intensity of atomic emission spectra of the additive in various regions of the plasma ring are compared to the results of numerical solution of the diffusion equation for the experimental conditions studied.

Understanding performance limitation and suppression of leakage current or self-discharge in electrochemical capacitors: a review.

PubMed

Ike, Innocent S; Sigalas, Iakovos; Iyuke, Sunny

2016-01-14

Self-discharge is known to have considerable adverse effects on the performance and application of electrochemical capacitors (ECs). Thus, obtaining an understanding of EC self-discharge mechanism(s) and subsequent derivation and solution of EC models, subject to a particular mechanism or combination of mechanisms during charging, discharging and storage of the device, is the only way to solve problems associated with EC self-discharge. In this review, we summarize recent progress with respect to EC self-discharge by considering the two basic types, electric double-layer capacitors (EDLC) and pseudocapacitors, and their hybrids with their respective charge storage mechanisms, distinguishable self-discharge mechanisms, charge redistribution and charge/energy loss during self-discharge. It was clearly observed that most of the voltage reduction is not purely due to the self-discharge effect but is basically due to redistribution of charge carriers deep inside pores and can therefore be retrieved from a capacitor during long-time discharging. Tuning the self-discharge rate is therefore feasible for single-walled carbon nanotube (SWNT) ECs and can be achieved by simply adjusting the surface chemistry of the nanotubes. The effects of surface chemistry modification on EC self-discharge are very important in studying and suppressing the self-discharge process and will benefit potential applications of ECs with respect to energy retention. Self-discharge can be averted by the use of redox couples that are transformed to insoluble species via electrolysis and adsorbed onto the activated carbon electrode in redox-couple EDLCs, thus transforming the EDLC electrolyte into a material that can store charge. Self-discharge in ECs can also be successfully suppressed by utilizing an ion-interchange layer (ion-exchange membrane), separator or CuSO4 mobile electrolyte that can be converted into an insoluble species by electrolysis during the charge/discharge process. This will help

Glow discharge based device for solving mazes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dubinov, Alexander E., E-mail: dubinov-ae@yandex.ru; Mironenko, Maxim S.; Selemir, Victor D.

2014-09-15

A glow discharge based device for solving mazes has been designed and tested. The device consists of a gas discharge chamber and maze-transformer of radial-azimuth type. It allows changing of the maze pattern in a short period of time (within several minutes). The device has been tested with low pressure air. Once switched on, a glow discharge has been shown to find the shortest way through the maze from the very first attempt, even if there is a section with potential barrier for electrons on the way. It has been found that ionization waves (striations) can be excited in themore » maze along the length of the plasma channel. The dependancy of discharge voltage on the length of the optimal path through the maze has been measured. A reduction in discharge voltage with one or two potential barriers present has been found and explained. The dependency of the magnitude of discharge ignition voltage on the length of the optimal path through the maze has been measured. The reduction of the ignition voltage with the presence of one or two potential barriers has been observed and explained.« less

Estimation of peak-discharge frequency of urban streams in Jefferson County, Kentucky

USGS Publications Warehouse

Martin, Gary R.; Ruhl, Kevin J.; Moore, Brian L.; Rose, Martin F.

1997-01-01

An investigation of flood-hydrograph characteristics for streams in urban Jefferson County, Kentucky, was made to obtain hydrologic information needed for waterresources management. Equations for estimating peak-discharge frequencies for ungaged streams in the county were developed by combining (1) long-term annual peakdischarge data and rainfall-runoff data collected from 1991 to 1995 in 13 urban basins and (2) long-term annual peak-discharge data in four rural basins located in hydrologically similar areas of neighboring counties. The basins ranged in size from 1.36 to 64.0 square miles. The U.S. Geological Survey Rainfall- Runoff Model (RRM) was calibrated for each of the urban basins. The calibrated models were used with long-term, historical rainfall and pan-evaporation data to simulate 79 years of annual peak-discharge data. Peak-discharge frequencies were estimated by fitting the logarithms of the annual peak discharges to a Pearson-Type III frequency distribution. The simulated peak-discharge frequencies were adjusted for improved reliability by application of bias-correction factors derived from peakdischarge frequencies based on local, observed annual peak discharges. The three-parameter and the preferred seven-parameter nationwide urban-peak-discharge regression equations previously developed by USGS investigators provided biased (high) estimates for the urban basins studied. Generalized-least-square regression procedures were used to relate peakdischarge frequency to selected basin characteristics. Regression equations were developed to estimate peak-discharge frequency by adjusting peak-dischargefrequency estimates made by use of the threeparameter nationwide urban regression equations. The regression equations are presented in equivalent forms as functions of contributing drainage area, main-channel slope, and basin development factor, which is an index for measuring the efficiency of the basin drainage system. Estimates of peak discharges for streams

Discharge Chamber Primary Electron Modeling Activities in Three-Dimensions

NASA Technical Reports Server (NTRS)

Steuber, Thomas J.

2004-01-01

Designing discharge chambers for ion thrusters involves many geometric configuration decisions. Various decisions will impact discharge chamber performance with respect to propellant utilization efficiency, ion production costs, and grid lifetime. These hardware design decisions can benefit from the assistance of computational modeling. Computational modeling for discharge chambers has been limited to two-dimensional codes that leveraged symmetry for interpretation into three-dimensional analysis. This paper presents model development activities towards a three-dimensional discharge chamber simulation to aid discharge chamber design decisions. Specifically, of the many geometric configuration decisions toward attainment of a worthy discharge chamber, this paper focuses on addressing magnetic circuit considerations with a three-dimensional discharge chamber simulation as a tool. With this tool, candidate discharge chamber magnetic circuit designs can be analyzed computationally to gain insight into factors that may influence discharge chamber performance such as: primary electron loss width in magnetic cusps, cathode tip position with respect to the low magnetic field volume, definition of a low magnetic field region, and maintenance of a low magnetic field region across the grid span. Corroborating experimental data will be obtained from mockup hardware tests. Initially, simulated candidate magnetic circuit designs will resemble previous successful thruster designs. To provide opportunity to improve beyond previous performance benchmarks, off-design modifications will be simulated and experimentally tested.

Dynamics of spiral patterns in gas discharge detected by optical method

NASA Astrophysics Data System (ADS)

Yang, Fan; Wang, Mingyi; Liu, Shuhua

2016-09-01

The dynamics behavior of spiral patterns is investigated in gas discharge using optical method. Rich kinks of spiral patterns are obtained and the formation and evolution process is investigated. The process of pattern formation is breakdown -> hexagon -> bee comb-like -> strip -> spiral -> chaos. Spiral pattern always formed after the strip pattern. It is found that the temperature of the water electrodes plays an important role in the spiral patterns formation. When it exceeds 20°C no spiral has been obtained. The discharge current waveform and the emission spectrum of the discharge have been measured when the filaments self-organized in spiral pattern. Electron excited temperature of forming spiral pattern is calculated using intensity ratio method. It is found that the electron excited temperature of spiral pattern increase as the power supply frequency increased. Relation between wavelength and discharge parameter has been measured. It shows that the wavelength of spiral pattern increases as the discharge gap increases, and decreases as the air ratio mixed in argon increases. Accompanying measurements proved that the wavelength is approximately linear to the square root of the spiral rotating period .This work has useful reference value for studying pattern dynamics.

Interactions between surface discharges induced by volume discharges in a dielectric barrier discharge system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Yenan; Dong, Lifang, E-mail: donglfhbu@163.com; Zhao, Longhu

2014-10-15

The interaction between micro-discharges involved in surface discharges (SDs) is studied in dielectric barrier discharge system. Instantaneous images taken by high speed cameras show that the SDs are induced by volume discharges (VDs). They cannot cross the midperpendicular of two neighbouring volume charges at low voltage while they stretch along it at high voltage, indicating that there is interaction between SDs. The differences of plasma parameters between SD and VD are studied by optical emission spectroscopy. The simulation of the electric fields of the wall charges accumulated by VD further confirms the existence of the interaction.

Psychiatric Discharge Process

PubMed Central

Alghzawi, Hamzah M.

2012-01-01

Background. Integration of research evidence into clinical nursing practice is essential for the delivery of high-quality nursing care. Discharge planning is an essential process in psychiatric nursing field, in order to prevent recurrent readmission to psychiatric units. Objective. The purpose of this paper is to perform literature overview on psychiatric discharge planning, in order to develop evidence-based practice guideline of psychiatric discharge plan. Methods. A search of electronic databases was conducted. The search process aimed to locate different levels of evidence. Inclusion criteria were studies including outcomes related to prevention of readmission as stability in the community, studies investigating the discharge planning process in acute psychiatric wards, and studies that included factors that impede discharge planning and factors that aid timely discharge. On the other hand, exclusion criteria were studies in which discharge planning was discussed as part of a multi faceted intervention and was not the main focus of the review. Result. Studies met inclusion criteria were mainly literature reviews, consensus statements, and descriptive studies. All of these studies are considered at the lower levels of evidence. Conclusion. This review demonstrated that discharge planning based on general principles (evidence based principles) should be applied during psychiatric discharge planning to make this discharge more effective. Depending on this review, it could be concluded that effective discharge planning includes main three stages; initial discharge meeting, regular discharge meeting(s), and leaving from hospital and discharge day. Each stage of them has requirements should be accomplished be go to the next stage. PMID:23762767

Numerical simulation and analysis of electromagnetic-wave absorption of a plasma slab created by a direct-current discharge with gridded anode

NASA Astrophysics Data System (ADS)

Yuan, Chengxun; Tian, Ruihuan; Eliseev, S. I.; Bekasov, V. S.; Bogdanov, E. A.; Kudryavtsev, A. A.; Zhou, Zhongxiang

2018-03-01

In this paper, we present investigation of a direct-current discharge with a gridded anode from the point of view of using it as a means of creating plasma coating that could efficiently absorb incident electromagnetic (EM) waves. A single discharge cell consists of two parallel plates, one of which (anode) is gridded. Electrons emitted from the cathode surface are accelerated in the short interelectrode gap and are injected into the post-anode space, where they lose acquired energy on ionization and create plasma. Numerical simulations were used to investigate the discharge structure and obtain spatial distributions of plasma density in the post-anode space. The numerical model of the discharge was based on a simple hybrid approach which takes into account non-local ionization by fast electrons streaming from the cathode sheath. Specially formulated transparency boundary conditions allowed performing simulations in 1D. Simulations were carried out in air at pressures of 10 Torr and higher. Analysis of the discharge structure and discharge formation is presented. It is shown that using cathode materials with lower secondary emission coefficients can allow increasing the thickness of plasma slabs for the same discharge current, which can potentially enhance EM wave absorption. Spatial distributions of electron density obtained during simulations were used to calculate attenuation of an incident EM wave propagating perpendicularly to the plasma slab boundary. It is shown that plasma created by means of a DC discharge with a gridded anode can efficiently absorb EM waves in the low frequency range (6-40 GHz). Increasing gas pressure results in a broader range of wave frequencies (up to 500 GHz) where a considerable attenuation is observed.

Interaction between pulsed discharge and radio frequency discharge burst at atmospheric pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Jie; College of Science, Donghua University, Shanghai 201620; Guo, Ying

The atmospheric pressure glow discharges (APGD) with dual excitations in terms of pulsed voltage and pulse-modulation radio frequency (rf) power are studied experimentally between two parallel plates electrodes. Pulse-modulation applied in rf APGD temporally separates the discharge into repetitive discharge bursts, between which the high voltage pulses are introduced to ignite sub-microsecond pulsed discharge. The discharge characteristics and spatio-temporal evolution are investigated by means of current voltage characteristics and time resolved imaging, which suggests that the introduced pulsed discharge assists the ignition of rf discharge burst and reduces the maintain voltage of rf discharge burst. Furtherly, the time instant ofmore » pulsed discharge between rf discharge bursts is manipulated to study the ignition dynamics of rf discharge burst.« less

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

A time-resolved Langmuir double-probe method for the investigation of pulsed magnetron discharges

NASA Astrophysics Data System (ADS)

Welzel, Th.; Dunger, Th.; Kupfer, H.; Richter, F.

2004-12-01

Langmuir probes are important means for the characterization of plasma discharges. For measurements in plasmas used for the deposition of thin films, the Langmuir double probe is especially suited. With the increasing popularity of pulsed deposition discharges, there is also an increasing need for time-resolved characterization methods. For Langmuir probes, several single-probe approaches to time-resolved measurements are reported but very few for the double probe. We present a time-resolved Langmuir double-probe technique, which is applied to a pulsed magnetron discharge at several 100 kHz used for MgO deposition. The investigations show that a proper treatment of the current measurement is necessary to obtain reliable results. In doing so, a characteristic time dependence of the charge-carrier density during the "pulse on" time containing maximum values of almost 2•1011cm-3 was found. This characteristic time dependence varies with the pulse frequency and the duty cycle. A similar time dependence of the electron temperature is only observed when the probe is placed near the magnesium target.

Phenomena of oscillations in atmospheric pressure direct current glow discharges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Fu-cheng; Yan, Wen; Wang, De-zhen

2013-12-15

Self-sustained oscillations in a dc glow discharge with a semiconductor layer at atmospheric pressure were investigated by means of a one-dimensional fluid model. It is found that the dc glow discharge initially becomes unstable in the subnormal glow region and gives rise to oscillations of plasma parameters. A variety of oscillations with one or more frequencies have been observed under different conditions. The discharge oscillates between the glow discharge mode and the Townsend discharge mode in the oscillations with large amplitude while operates in the subnormal glow discharge mode all the while in the oscillations with small amplitude. Fourier Transformmore » spectra of oscillations reveal the transition mechanism between different oscillations. The effects of semiconductor conductivity on the oscillation frequency of the dominant mode, gas voltage, as well as the discharge current have also been analyzed.« less

A study of point discharge current observations in the thunderstorm environment at a tropical station during the year 1987 and 1988

NASA Technical Reports Server (NTRS)

Manohar, G. K.; Kandalgaonkar, S. S.; Sholapurkar, S. M.

1991-01-01

The results of the measurements of point discharge current observations at Pune, India, during years 1987 and 1988 are presented by categorizing and studying their number of spells, polar current average durations, and current magnitudes in day-time and night-time conditions. While the results showed that the thunderstorm activity occupies far more day-time than the night-time the level of current magnitudes remains nearly the same in the two categories.

Spatial Representativeness of PM2.5 Concentrations Obtained Using Observations From Network Stations

NASA Astrophysics Data System (ADS)

Shi, Xiaoqin; Zhao, Chuanfeng; Jiang, Jonathan H.; Wang, Chunying; Yang, Xin; Yung, Yuk L.

2018-03-01

Haze has been a focused air pollution phenomenon in China, and its characterization is highly desired. Aerosol properties obtained from a single station are frequently used to represent the haze condition over a large domain, such as tens of kilometers, which could result in high uncertainties due to their spatial variation. Using a high-resolution network observation over an urban city in North China from November 2015 to February 2016, this study examines the spatial representativeness of ground station observations of particulate matter with diameters less than 2.5 μm (PM2.5). We developed a new method to determine the representative area of PM2.5 measurements from limited stations. The key idea is to determine the PM2.5 spatial representative area using its spatial variability and temporal correlation. We also determine stations with large representative area using two grid networks with different resolutions. Based on the high spatial resolution measurements, the representative area of PM2.5 at one station can be determined from the grids with high correlations and small differences of PM2.5. The representative area for a single station in the study period ranges from 0.25 to 16.25 km2 but is less than 3 km2 for more than half of the stations. The representative area varies with locations, and observation at 10 optimal stations would have a good representativeness of those obtained from 169 stations for the 4 month time scale studied. Both evaluations with an empirical orthogonal function analysis and with independent data set corroborate the validity of the results found in this study.

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 ...

Discharge rate measurements for Micromegas detectors in the presence of a longitudinal magnetic field

NASA Astrophysics Data System (ADS)

Moreno, B.; Aune, S.; Ball, J.; Charles, G.; Giganon, A.; Konczykowski, P.; Lahonde-Hamdoun, C.; Moutarde, H.; Procureur, S.; Sabatié, F.

2011-10-01

We present first discharge rate measurements for Micromegas detectors in the presence of a high longitudinal magnetic field in the GeV kinematical region. Measurements were performed by using two Micromegas detectors and a photon beam impinging a CH 2 target in the Hall B of the Jefferson Laboratory. One detector was equipped with an additional GEM foil, and a reduction of the discharge probability by two orders of magnitude compared to the stand-alone Micromegas was observed. The detectors were placed in the FROST solenoid providing a longitudinal magnetic field up to 5 T. It allowed for precise measurements of the discharge probability dependence with a diffusion-reducing magnetic field. Between 0 and 5 T, the discharge probability increased by a factor of 10 for polar angles between 19° and 34°. A GEANT4-based simulation developed for sparking rate calculation was calibrated against these data in order to predict the sparking rate in a high longitudinal magnetic field environment. This simulation is then used to investigate the possible use of Micromegas in the Forward Vertex Tracker (FVT) of the future CLAS12 spectrometer. In the case of the FVT a sparking rate of 1 Hz per detector was obtained at the anticipated CLAS12 luminosity.

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 - discharge; ...

Tonle Sap Lake Water Storage Change Over 24 Years From Satellite Observation and Its Link With Mekong River Discharge and Climate Events

NASA Astrophysics Data System (ADS)

Biancamaria, S.; Frappart, F.; Normandin, C.; Blarel, F.; Bourrel, L.; Aumont, M.; Azema, P.; Vu, P. L.; Lubac, B.; Darrozes, J.

2017-12-01

The Tonle Sap lake is the largest freshwater lake in Southeast Asia and is located within the Mekong basin (mainly in Cambodia). It is one of he most productive ecosystem of the world and provide two thirds of Cambodia fish catch. It also plays a unique role on the Mekong basin hydrological cycle: during the monsoon period, the Mekong river partially flows to the lake, whereas during the dry season, the lake flows to the Mekong delta. It is therefore crucial to monitor and take into account this lake to estimate Mekong discharge to the ocean. However, in situ measurements of lake level and river discharge are very sparse (especially during the last decades) and computing lake storage variation from in situ data only is difficult due to the huge annual variation of lake area. That's why, satellite data (nadir radar altimetry and visible imagery) have been used to study its volume variation and its relationship with climate events and Mekong river discharge. Multi-mission altimetry data have been extracted (Topex, ERS-2, ENVISAT, Jason-1, Jason-2, Saral and Jason-3, using CTOH data extraction tools) to derive a lake water level from1993 to 2016, which varies from 3 m to 12 m. Lake area have been computed from MODIS data from 2000 to 2016 and varies from 3,400 km2 to 11,800 km2. These dataset clearly shows a relationship between lake water level and area, which has been used to estimate lake water volume change from 1995 to 2016, with a minimum in 2015 and a maximum in 2011. Lake's droughts and floods can be observed during moderate and strong El Nino/La Nina events, enhanced by the Pacific Decadal Oscillation. Besides, comparison with in situ discharge at the outlet of the Mekong basin (over 1995/2000 time period) shows that lake water level is 20 days time lagged and increases/decreases after Mekong discharge at its outlet. This time lag results of Mekong river partially flowing to the lake. Finally, high correlation between lake level and outlet discharge allows to

[Morphology determination of multi-needle-to-plate positive corona discharge].

PubMed

Su, Peng-hao; Zhu, Yi-min; Chen, Hai-feng

2008-09-01

Using the method of OES (optical emission spectrum) for measuring N2 emission spectrum, the distribution of the energetic electrons in multi-needle-to-plate positive corona discharge at atmospheric pressure was investigated, and compared with that in negative corona discharge. According to the distribution of N2 second positive band's intensity I(SPB), the outline of the ionization region in glow discharge and the streamer channel were drawn rather accurately. The relationship between I(SPB) and the discharge current I in glow discharge can be obtained through the volume integral of the I(SPB). In glow discharge, both the ionization region scale and I(SPB) are smaller than in negative corona discharge, the electron avalanche develops farther along the radius direction of needle than along axis direction, and only the arrange along axis direction is enhanced slightly with the rise of the applied voltage U. The integral of I(SPB) is second order linear to I. In streamer discharge, the discharge channels develop from needlepoint to the plate, while the shape of the region in which I(SPB) is higher looks like a bullet. The density of energetic electron in the channel farther away from the needlepoint is relatively uniform along the axis direction, but first increases then decreases along the radius direction.

Glow discharge cleaning of vacuum switch tubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayashi, T.; Toya, H.

1991-10-01

This paper reports that glow discharge cleaning has ben advancing as a means of degassing vacuum chambers constructed for a large accelerator or for nuclear fusion research. To clean the whole surface of parts inside a vacuum switch tube (VST), a new technique is tried which generates glow discharge between the inner electrodes and copper grid surrounding it. Photographic observation reveals that the glow discharge spreads out and cleans the whole surface inside the VST. A breakdown test between the inner electrodes shows the effect of the cleaning with this technique. Higher breakdown voltage between the inner electrodes is attainedmore » by performing this glow discharge cleaning in argon rather than hydrogen gas. The difference of the cleaning effect seems to be attributed to that of the energy transfer from ion species to the absorbed molecules and microprotrusions on the surfaces.« less

Psychiatric diagnosis and differential risks of offending following discharge.

PubMed

Coid, Jeremy W; Yang, Min; Ullrich, Simone; Hickey, Nicole; Kahtan, Nadji; Freestone, Mark

2015-01-01

Psychiatric diagnosis is not considered a risk factor for offending following discharge. However, treatment interventions and aftercare are strongly influenced by clinical primary diagnosis. We compared differential risks of reoffending of patients falling into six primary diagnostic categories following discharge from Medium Secure Units in the UK: schizophrenia/schizoaffective disorder; delusional disorder; mania/hypomania; depressive disorder; organic brain syndrome; personality disorder. We followed up 1344 patients, on average 6.2 years (SD=2.1) at risk, discharged from 7 of 14 Regional Medium Secure services in England and Wales. Outcomes were period prevalence, incidence, and cumulative probability of criminal conviction. Established demographic and criminal history predictors of reoffending were observed across different diagnostic categories. Risks of all offending were increased for personality disorder, violence/acquisitive offending for delusional disorder, sexual offending for mania/hypomania and violence/acquisitive offending for organic brain syndrome. Patterns of risk over time differed markedly between categories of mental disorder. Most patients with personality disorder who offended violently did so within 4 years of discharge. A subgroup with delusional disorder demonstrated increased risk of violent offending 5 years after discharge. Differential risks of reoffending are observed between different diagnostic groups. Clinical diagnosis should be included together with established risk measures in risk management following discharge. Close supervision of patients with personality disorder should begin immediately after discharge when risks of reoffending are greatest. For delusional disorder further investigation is needed into the marked increase in risk of violence after 5 years. Copyright © 2015 Elsevier Ltd. All rights reserved.

Gallbladder removal - laparoscopic - discharge

MedlinePlus

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

Control of plasma-liquid interaction of atmospheric DC glow discharge using liquid electrode

NASA Astrophysics Data System (ADS)

Shirai, Naoki; Aoki, Ryuta; Nito, Aihito; Aoki, Takuya; Uchida, Satoshi; Tochikubo, Fumiyoshi

2014-10-01

Atmospheric plasma in contact with liquid have a variety of interesting phenomena and applications. Previously, we investigated the fundamental characteristics of an atmospheric dc glow discharge using a liquid electrode with a miniature helium flow. We tried to control the plasma-liquid interaction by changing the plasma parameter such as gas species, liquid, and applied voltage. Sheath flow system enables another gas (N2, O2, Ar) flow to around the helium core flow. It can control the gas species around the discharge. When liquid (NaCl aq.) cathode DC discharge is generated, Na emission (588 nm) can be observed from liquid surface with increasing discharge current. Na emission strongly depends on the discharge current and liquid temperature. However, when Ar sheath flow is used, the intensity of Na becomes weak. When liquid anode DC discharge is generated, self-organized luminous pattern formation can be observed at the liquid surface. The pattern depends on existence of oxygen gas in gap. By changing the oxygen gas ratio in the gap, variety of pattern formation can be observed. The discharge in contact with liquid also can be used for synthesis of metal nanoparticles at plasma-liquid interface. Size and shape of nanoparticles depend on discharge gases. This work was supported financially in part by a Grant-in-Aid for Scientific Research on Innovative Areas (No 21110007) from MEXT, Japan.

Pediatric heart surgery - discharge

MedlinePlus

... of the aorta repair - discharge; Heart surgery for children - discharge; Atrial septal defect repair - discharge; Ventricular septal ... discharge; Acquired heart disease - discharge; Heart valve surgery - ... Heart surgery - pediatric - discharge; Heart transplant - pediatric - ...

Vessel Sewage Discharges: No-Discharge Zones (NDZs)

EPA Pesticide Factsheets

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

Characteristics of soft x-ray spectra from ultra-fast micro-capillary discharge plasmas

NASA Astrophysics Data System (ADS)

Li, Jing; Avaria, Gonzalo; Shlyaptsev, Vyacheslav; Tomasel, Fernando; Grisham, Michael; Dawson, Quincy; Rocca, Jorge; NSF CenterExtreme Ultraviolet Science; Technology Collaboration

2013-10-01

The efficient generation of high aspect ratio (e.g. 300:1) plasma columns ionized to very high degrees of ionization (e.g. Ni-like Xenon) by an ultrafast current pulses of moderate amplitude in micro-capillary channels is of interest for fundamental plasma studies and for applications such as the generation of discharge-pumped soft x-ray lasers. Spectra and simulations for plasmas generated in 500 um alumina capillary discharges driven by 35-40 kA current pulses with 4 ns rise time were obtained in Xenon and Neon discharges. The first shows the presence of lines corresponding to ionization stages up to Fe-like Xe. The latter show that Al impurities from the walls and Si (from injected SiH4) are ionized to the H-like and He-like stages. He-like spectra containing the resonance line significantly broaden by opacity, the intercombination line, and Li-like satellites are analyzed and modeled. For Xenon discharges, the spectral lines from the Ni-like transitions the 3d94d(3/2, 3/2)J=0 to the 3d94p(5/2, 3/2)J=1 and to 3d94p(3/2, 1/2)J=1 are observed at gas pressures up to 2.0 Torr. Work supported by NSF Award PHY-1004295.

Understanding clinician influences and patient perspectives on outpatient discharge decisions: a qualitative study

PubMed Central

Harun, N A; Salek, S

2017-01-01

Objective To observe the influences on clinicians when discharging patients, to explore patients' perspectives concerning their discharge or follow-up decision and to identify what patients think is important for clinicians to consider when taking a discharge decision. Design Qualitative study involving observations of consultations and semistructured interviews with outpatients. Setting National Health Service outpatient clinics at a university hospital secondary referral centre. Participants 64 consultations were observed followed by 56 interviews with patients aged over 18 years. Main outcome measure Analysis of patients' perspectives and expectations concerning whether or not they were discharged. Results 25 types of influences were observed to be influencing the discharge decision process. All 31 discharged patients appeared to accept the clinicians' decision; however, 10 (22%) of those patients later expressed disappointment. Patients' discontent was due to perceived clinicians' uncertainty in diagnosis (patients mentioning=2), poor acceptance of the diagnosis (2), disease not ‘cured’ (4), differing perception on medical needs (2), lack of concern for job demands (1), felt uninvolved in the decision-making (4), feeling rushed (3), prolonged open appointment (2), pushed to seek private care due to healthcare budget constraints (2), language barrier (1) and not keen to continue follow-up with general practitioner (2). Patients were happy when there was certainty of the diagnosis (19), clear treatment plan (16), advised on treatment side effects (7), given a contact number if symptoms recurred (4), considering their travelling and job demands (3). Conclusions This study highlights the importance of accurately perceiving patients' perspectives in ensuring the appropriateness of outpatient discharge. There was a disparity between patients' and clinicians' perception on what was an appropriate discharge. This included discrepancies concerning diagnostic

Numerical Simulation of a Nanosecond Pulse Discharge in Mach 5 Flow

DTIC Science & Technology

2013-01-01

Numerical Simulation of a Nanosecond Pulse Discharge in Mach 5 Flow Jonathan Poggie∗and Nicholas J. Bisek† Air Force Research Laboratory, Wright...was developed for nanosecond- pulse discharges , including real- istic air kinetics, electron energy transport, and compressible bulk gas flow. A reduced...shock waves originating near the sheath edge, consistent with experimental observations. I. Introduction In a nanosecond- pulse discharge , the input

Availability of mobile phones for discharge follow-up of pediatric Emergency Department patients in western Kenya

PubMed Central

Cheptinga, Philip; Rusyniak, Daniel E.

2015-01-01

Objective. Mobile phones have been successfully used for Emergency Department (ED) patient follow-up in developed countries. Mobile phones are widely available in developing countries and may offer a similar potential for follow-up and continued care of ED patients in low and middle-income countries. The goal of this study was to determine the percentage of families with mobile phones presenting to a pediatric ED in western Kenya and rate of response to a follow-up phone call after discharge. Methods. A prospective, cross-sectional observational study of children presenting to the emergency department of a government referral hospital in Eldoret, Kenya was performed. Documentation of mobile phone access, including phone number, was recorded. If families had access, consent was obtained and families were contacted 7 days after discharge for follow-up. Results. Of 788 families, 704 (89.3%) had mobile phone access. Of those families discharged from the ED, successful follow-up was made in 83.6% of cases. Conclusions. Mobile phones are an available technology for follow-up of patients discharged from a pediatric emergency department in resource-limited western Kenya. PMID:25780757

Availability of mobile phones for discharge follow-up of pediatric Emergency Department patients in western Kenya.

PubMed

House, Darlene R; Cheptinga, Philip; Rusyniak, Daniel E

2015-01-01

Objective. Mobile phones have been successfully used for Emergency Department (ED) patient follow-up in developed countries. Mobile phones are widely available in developing countries and may offer a similar potential for follow-up and continued care of ED patients in low and middle-income countries. The goal of this study was to determine the percentage of families with mobile phones presenting to a pediatric ED in western Kenya and rate of response to a follow-up phone call after discharge. Methods. A prospective, cross-sectional observational study of children presenting to the emergency department of a government referral hospital in Eldoret, Kenya was performed. Documentation of mobile phone access, including phone number, was recorded. If families had access, consent was obtained and families were contacted 7 days after discharge for follow-up. Results. Of 788 families, 704 (89.3%) had mobile phone access. Of those families discharged from the ED, successful follow-up was made in 83.6% of cases. Conclusions. Mobile phones are an available technology for follow-up of patients discharged from a pediatric emergency department in resource-limited western Kenya.

Electron concentration distribution in a glow discharge in air flow

NASA Astrophysics Data System (ADS)

Mukhamedzianov, R. B.; Gaisin, F. M.; Sabitov, R. A.

1989-04-01

Electron concentration distributions in a glow discharge in longitudinal and vortex air flows are determined from the attenuation of the electromagnetic wave passing through the plasma using microwave probes. An analysis of the distribution curves obtained indicates that electron concentration decreases in the direction of the anode. This can be explained by charge diffusion toward the chamber walls and electron recombination and sticking within the discharge.

Prebreakdown phenomena and formation process of the glow discharge in low-pressure Ar gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hosokawa, Tatsuzo; Goto, Kazuhiro; Ohuchi, Mikio

2001-06-01

The prebreakdown phenomena and the formation process of the glow discharge in a low-pressure Ar gas were investigated under a uniform field gap. Prebreakdown phenomena were observed for 0.5Torrcm{le}pd{le}2Torrcm (where p is pressure, d the gap distance) in Ar gas under conditions of a slowly increasing voltage. It was observed that the prebreakdown phenomena formed pulse discharges up to the transition to the glow discharge. The amplitudes of the photon and current pulses due to the pulse discharge increased with time, and then decreased as soon as the transition to a steady glow discharge occurred. When the overvoltage or externalmore » series resistance was increased, the pulse amplitudes increased with the applied voltage and decreased with the resistance. The characteristics of the prebreakdown phenomena were changed by the shape of the electrodes. The formation mechanism of the glow discharge can be qualitatively explained by that of the streamer in a high-pressure discharge. The transient glow discharge was observed, and its duration increased with an increase in resistance. The instability of the glow discharge was controlled by three factors, namely, Kaufmann{close_quote}s criterion, the Child{endash}Langmuir law, and the density balance between the production and removal rates of electrons. {copyright} 2001 American Institute of Physics.« less

A fully redundant double difference algorithm for obtaining minimum variance estimates from GPS observations

NASA Technical Reports Server (NTRS)

Melbourne, William G.

1986-01-01

In double differencing a regression system obtained from concurrent Global Positioning System (GPS) observation sequences, one either undersamples the system to avoid introducing colored measurement statistics, or one fully samples the system incurring the resulting non-diagonal covariance matrix for the differenced measurement errors. A suboptimal estimation result will be obtained in the undersampling case and will also be obtained in the fully sampled case unless the color noise statistics are taken into account. The latter approach requires a least squares weighting matrix derived from inversion of a non-diagonal covariance matrix for the differenced measurement errors instead of inversion of the customary diagonal one associated with white noise processes. Presented is the so-called fully redundant double differencing algorithm for generating a weighted double differenced regression system that yields equivalent estimation results, but features for certain cases a diagonal weighting matrix even though the differenced measurement error statistics are highly colored.

Confirmed Assignments of Isomeric Dimethylbenzyl Radicals Generated by Corona Discharge

NASA Astrophysics Data System (ADS)

Yoon, Young Wook; Lee, Sang Kuk

2012-06-01

Polymethylbenzyl radicals, multi-methyl-substituted benzyl radicals, have been believed to be an ideal model for understanding the torsional effect of methyl group and substitution effect on electronic transition. These radicals are mainly generated from polymethylbenzenes by electric discharge for spectroscopic observation. However, the existence of several methyl groups on the benzene ring may produce several isomeric polymethylbenzyl radicals by removing one of the C-H bonds of each methyl group at different substitution position, which makes the assignment of spectrum ambiguous. In this work, the controversial vibronic assignments of isomeric dimethylbenzyl radicals were clearly resolved by using different precursors. By using corresponding dimethylbenzyl chlorides as precursors, we identified the origins of the vibronic bands of the dimethylbenzyl radicals generated by corona discharge of precursors 1,2,3- and 1,2,4-trimethylbenzenes. From the analysis of the spectra observed from the dimethylbenzyl chlorides in a corona excited supersonic expansion using a pinhole-type glass nozzle, we revised previous assignments of the 2,6- and 2,3-dimethylbenzyl radicals as well as the 3,4-, 2,4-, and 2,5-dimethylbenzyl radicals. In addition, spectroscopic data of electronic transition and vibrational mode frequencies in the ground electronic state of each isomer were accurately determined by comparing them with those obtained by an ab initio calculation and with the known vibrational data of precursors.

A Multidisciplinary Initiative to Increase Inpatient Discharges Before Noon.

PubMed

Kane, Marlena; Weinacker, Ann; Arthofer, Rudolph; Seay-Morrison, Timothy; Elfman, Wesley; Ramirez, Mark; Ahuja, Neera; Pickham, David; Hereford, James; Welton, Mark

2016-12-01

The aim of this study is to evaluate the effect of 2 hospital-wide interventions on achieving a discharge-before-noon rate of 40%. A multidisciplinary team led by administrative and physician leadership developed a plan to diminish capacity constraints by minimizing late afternoon hospital discharges using 2 patient flow management techniques. The study was a preintervention/postintervention retrospective analysis observing all inpatients discharged across 19 inpatient units in a 484-bed, academic teaching hospital measuring calendar month discharge-before-noon percentage, patient satisfaction, and readmission rates. Patient satisfaction and readmission rates were used as baseline metrics. The discharge-before-noon percentage increased from 14% in the 11-month preintervention period to an average of 24% over the 11-month postintervention period, whereas patient satisfaction scores and readmission rates remained stable. Implementation of the 2 interventions successfully increased the percentage of discharges before noon yet did not achieve the goal of 40%. Patient satisfaction and readmission rates were not negatively impacted by the program.

Simulation of nonstationary phenomena in atmospheric-pressure glow discharge

NASA Astrophysics Data System (ADS)

Korolev, Yu. D.; Frants, O. B.; Nekhoroshev, V. O.; Suslov, A. I.; Kas'yanov, V. S.; Shemyakin, I. A.; Bolotov, A. V.

2016-06-01

Nonstationary processes in atmospheric-pressure glow discharge manifest themselves in spontaneous transitions from the normal glow discharge into a spark. In the experiments, both so-called completed transitions in which a highly conductive constricted channel arises and incomplete transitions accompanied by the formation of a diffuse channel are observed. A model of the positive column of a discharge in air is elaborated that allows one to interpret specific features of the discharge both in the stationary stage and during its transition into a spark and makes it possible to calculate the characteristic oscillatory current waveforms for completed transitions into a spark and aperiodic ones for incomplete transitions. The calculated parameters of the positive column in the glow discharge mode agree well with experiment. Data on the densities of the most abundant species generated in the discharge (such as atomic oxygen, metastable nitrogen molecules, ozone, nitrogen oxides, and negative oxygen ions) are presented.

Simulation of nonstationary phenomena in atmospheric-pressure glow discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korolev, Yu. D., E-mail: korolev@lnp.hcei.tsc.ru; Frants, O. B.; Nekhoroshev, V. O.

2016-06-15

Nonstationary processes in atmospheric-pressure glow discharge manifest themselves in spontaneous transitions from the normal glow discharge into a spark. In the experiments, both so-called completed transitions in which a highly conductive constricted channel arises and incomplete transitions accompanied by the formation of a diffuse channel are observed. A model of the positive column of a discharge in air is elaborated that allows one to interpret specific features of the discharge both in the stationary stage and during its transition into a spark and makes it possible to calculate the characteristic oscillatory current waveforms for completed transitions into a spark andmore » aperiodic ones for incomplete transitions. The calculated parameters of the positive column in the glow discharge mode agree well with experiment. Data on the densities of the most abundant species generated in the discharge (such as atomic oxygen, metastable nitrogen molecules, ozone, nitrogen oxides, and negative oxygen ions) are presented.« less

Self-Organized Patterns in Gas-Discharge: Particle-Like Behaviour and Dissipative Solitons

NASA Astrophysics Data System (ADS)

Purwins, H.-G.

2008-03-01

The understanding of self-organise patterns in spatially extended nonlinear dissipative systems (SOPs) is one of the most challenging subjects in modern natural sciences. In the last 20 years it turned out that research in the field of low temperature gas-discharge can help to obtain insight into important aspect of SOPs. At the same time, due to the practical relevance of plasma systems one might expect interesting applications. In the present paper the focus is on self-organised filamentary patterns in planar dc and ac systems with high ohmic and dielectric barrier, respectively. - In the discharge plane of these systems filaments show up as spots which are also referred to as dissipative solitons (DSs). In many respect experimentally detected DSs exhibit particle-like behaviour. Among other things, isolated stationary or travelling DSs, stationary, travelling or rotating "molecules" and various kinds of many-body systems have been observed. Also scattering, generation and annihilation of DSs are frequent phenomena. - At least some of these patterns can be described quantitatively in terms of a drift diffusion model. It is also demonstrated that a simple reaction diffusion model allows for an intuitive understanding of many of the observed phenomena. At the same time this model is the basis for a theoretical foundation of the particle picture and the experimentally observed universal behaviour of SOPs. - Finally some hypothetical applications are discussed.

Combination of satellite based thermal remote sensing and in situ radon measurements and field observations to detect (submarine) groundwater discharge

NASA Astrophysics Data System (ADS)

Mallast, U.; Schubert, M.; Schmidt, A.; Knoeller, K.; Stollberg, R.; Siebert, C.; Merz, R.

2012-12-01

Submarine groundwater discharge (SGD) is an important factor in the understanding and sustainable management of coastal freshwater aquifers in many highly populated coastal areas worldwide. This is not only due to the fact that SGD represents (i) a significant pathway for transfer of matter between land and sea as it supplies nutrients and trace metals to coastal oceans and (ii) a contamination threat to the near-shore marine environment resulting from land-based activities. It means also that potentially significant freshwater quantities are lost to the sea in e.g. arid areas, where groundwater is the main water resource (IAEA, 2007). The quantitative estimation of SGD is complicated due to its large temporal and spatial variability. Several studies attempted to quantify SGD rates using seepage meters, piezometers or geochemical tracers (Taniguchi et al., 2002). In most of these studies the actual SGD locations were known. In cases of unknown discharge locations airborne- and recently spaceborne-thermal remote sensing were used for detection (Roxburgh, 1985; Wilson and Rocha, 2012). Presented approaches applied only single images that represent only a temporal snapshot and hence possibly a non-representative picture of the discharge behavior (e.g. stormdriven or dry periods). Due to the continuous satellite image recording (Landsat TM/ETM+), numerous images exist that can be exploited against the background of temperature contrasts between discharging groundwater and ocean water. Hence, integrating multiple images recorded at different times does not only account for the intermittent character of groundwater discharge but enables to derive representative SGD information. We will present a satellite-based multi-thermal image method which exploits the fact that continuously discharging groundwater stabilizes the temperature at the discharge location and hence displays small temperature variability. In contrast, ambient unaffected areas clearly follow the seasonal

Length bounds for connecting discharges in triggered lightning subsequent strokes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Idone, V.P.

1990-11-20

Highly time resolved streak recordings from nine subsequent strokes in four triggered flashes have been examined for evidence of the occurrence of upward connecting discharges. These photographic recordings were obtained with superior spatial and temporal resolution (0.3 m and 0.5 {lambda}s) and were examined with a video image analysis system to help delineate the separate leader and return stroke image tracks. Unfortunately, a definitive determination of the occurrence of connecting discharges in these strokes could not be made. The data did allow various determinations of an upper bound length for any possible connecting discharge in each stroke. Under the simplestmore » analysis approach possible, an 'absolute' upper bound set of lengths was measured that ranged from 12 to 27 m with a mean of 19 m; two other more involved analyses yielded arguably better upper bound estimates of 8-18 m and 7-26 m with means of 19 m; two other more involved analyses yielded arguably better upper bound estimates of 8-18 m and 7-26 m with means of 12 and 13 m, respectively. An additional set of low time-resolution telephoto recordings of the lowest few meters of channel revealed six strokes in these flashes with one or more upward unconnected channels originating from the lightning rod tip. The maximum length of unconnected channel seen in each of these strokes ranged from 0.2 to 1.6 m with a mean of 0.7 m. This latter set of observations is interpreted as indirect evidence that connecting discharges did occur in these strokes and that the lower bound for their length is about 1 m.« less

Characterization of Microwave-Induced Electric Discharge Phenomena in Metal–Solvent Mixtures

PubMed Central

Chen, Wen; Gutmann, Bernhard; Kappe, C Oliver

2012-01-01

Electric discharge phenomena in metal–solvent mixtures are investigated utilizing a high field density, sealed-vessel, single-mode 2.45 GHz microwave reactor with a built-in camera. Particular emphasis is placed on studying the discharges exhibited by different metals (Mg, Zn, Cu, Fe, Ni) of varying particle sizes and morphologies in organic solvents (e.g., benzene) at different electric field strengths. Discharge phenomena for diamagnetic and paramagnetic metals (Mg, Zn, Cu) depend strongly on the size of the used particles. With small particles, short-lived corona discharges are observed that do not lead to a complete breakdown. Under high microwave power conditions or with large particles, however, bright sparks and arcs are experienced, often accompanied by solvent decomposition and formation of considerable amounts of graphitized material. Small ferromagnetic Fe and Ni powders (<40 μm) are heated very rapidly in benzene suspensions and start to glow in the microwave field, whereas larger particles exhibit extremely strong discharges. Electric discharges were also observed when Cu metal or other conductive materials such as silicon carbide were exposed to the microwave field in the absence of a solvent in an argon or nitrogen atmosphere. PMID:24551491

Characterization of microwave-induced electric discharge phenomena in metal-solvent mixtures.

PubMed

Chen, Wen; Gutmann, Bernhard; Kappe, C Oliver

2012-02-01

Electric discharge phenomena in metal-solvent mixtures are investigated utilizing a high field density, sealed-vessel, single-mode 2.45 GHz microwave reactor with a built-in camera. Particular emphasis is placed on studying the discharges exhibited by different metals (Mg, Zn, Cu, Fe, Ni) of varying particle sizes and morphologies in organic solvents (e.g., benzene) at different electric field strengths. Discharge phenomena for diamagnetic and paramagnetic metals (Mg, Zn, Cu) depend strongly on the size of the used particles. With small particles, short-lived corona discharges are observed that do not lead to a complete breakdown. Under high microwave power conditions or with large particles, however, bright sparks and arcs are experienced, often accompanied by solvent decomposition and formation of considerable amounts of graphitized material. Small ferromagnetic Fe and Ni powders (<40 μm) are heated very rapidly in benzene suspensions and start to glow in the microwave field, whereas larger particles exhibit extremely strong discharges. Electric discharges were also observed when Cu metal or other conductive materials such as silicon carbide were exposed to the microwave field in the absence of a solvent in an argon or nitrogen atmosphere.

Magnetic tearing of plasma discharges due to nonuniform resistivity

NASA Technical Reports Server (NTRS)

Hassam, A. B.

1988-01-01

The rearrangement of current in a plasma discharge in response to resistivity nonuniformities within a magnetic surface is studied. It is shown that macroscopic magnetic islands develop about those surfaces where the nonuniformity is aligned with the magnetic field. If the nonuniformity and the field are not aligned anywhere, there is no current rearrangement; instead, relatively large plasma flows are set up. Such resistivity inhomogeneities can obtain in solar coronal loops and, in some circumstances, in tokamak discharges.

Snowmelt discharge characteristics Sierra Nevada, California

USGS Publications Warehouse

Peterson, David; Smith, Richard; Stewart, Iris; Knowles, Noah; Soulard, Chris; Hager, Stephen

2005-01-01

Alpine snow is an important water resource in California and the western U.S. Three major features of alpine snowmelt are the spring pulse (the first surge in snowmelt-driven river discharge in spring), maximum snowmelt discharge, and base flow (low river discharge supported by groundwater in fall). A long term data set of hydrologic measurements at 24 gage locations in 20 watersheds in the Sierra Nevada was investigated to relate patterns of snowmelt with stream discharge In wet years, the daily variations in snowmelt discharge at all the gage locations in the Sierra Nevada correlate strongly with the centrally located Merced River at Happy Isles, Yosemite National Park (i.e., in 1983, the mean of the 23 correlations was R= 0.93 + 0.09) ; in dry years, however, this correlation breaks down (i.e., in year 1977, R=0.72 + 0.24). A general trend towards earlier snowmelt was found and modeled using correlations with the timing of the spring pulse and the river discharge center of mass. For the 24 river and creek gage locations in this study, the spring pulse appeared to be a more sensitive measure of early snowmelt than the center of mass. The amplitude of maximum daily snowmelt discharge correlates strongly with initial snow water equivalent. Geologic factors, base rock permeability and soil-to-bedrock ratio, influence snowmelt flow pathways. Although both surface and ground water flows and water levels increase in wet years compared to dry years, the increase was greater for surface water in a watershed with relatively impermeable base rock than for surface water in a watershed with highly permeable base rock The relation was the opposite for base flow (ground water). The increase was greater for groundwater in a watershed with permeable rock compared to ground water in a watershed with impermeable rock. A similar, but weaker, surface/groundwater partitioning was observed in relatively impermeable granitic watersheds with differing soil-to-bedrock ratios. The

High-current discharge channel contraction in high density gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rutberg, Ph. G.; Bogomaz, A. A.; Pinchuk, M. E.

Research results for discharges at current amplitudes of 0.5-1.6 MA and current rise rate of {approx}10{sup 10} A/s are presented. The discharge is performed in the hydrogen environment at the initial pressure of 5-35 MPa. Initiation is implemented by a wire explosion. The time length of the first half-period of the discharge current is 70-150 {mu}s. Under such conditions, discharge channel contraction is observed; the contraction is followed by soft x-ray radiation. The phenomena are discussed, which are determined by high density of the gas surrounding the discharge channel. These phenomena are increase of the current critical value, where themore » channel contraction begins and growth of temperature in the axis region of the channel, where the initial density of the gas increases.« less

Experimental investigation on the effect of plasma jet in the triggered discharge process of a gas switch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tie, W., E-mail: twh.110.666@163.com, E-mail: 84470220@qq.com; Xi'an Jiaotong University, Xi'an 710049; Liu, S.

The temporal and spatial evolution of a plasma jet generated by a spark discharge was observed. The electron temperature and density were obtained under different time and gas pressures by optical emission spectroscopy. Moreover, the discharge process of the plasma-jet triggered gas switch was recorded and analyzed at the lowest working coefficient. The results showed that the plasma jet moved forward in a bullet mode, and the advancing velocity increased with the decrease of pressure, and decreased with time growing. At initial time, the maximum velocity of a plasma jet could reach 3.68 × 10{sup 6 }cm/s. The electron temperature decreased from 2.0 eVmore » to 1.3 eV, and the electron density increased from 3.1 × 10{sup 15}/cm{sup 3} to 6.3 × 10{sup 15}/cm{sup 3} at the initial moment as the gas pressure increases from 0.1 MPa to 0.32 MPa. For a two-gap gas switch, the discharge performances were more depended on the second discharge spark gap (gap 2). Because plasma jet promoted the discharge in Gap 2, the gas switch operating in mode II had better triggered discharge characteristics. In the discharge process, the plasma-jet triggering had the effect of non-penetrating inducing, which not only provided initial electrons for reducing statistical lag but also enhanced the local electric field. The discharge was initiated and accelerated from electron avalanche to streamer. Therefore, a fast discharge was occurred in the gas switch.« less

Computer programs for describing the recession of ground-water discharge and for estimating mean ground-water recharge and discharge from streamflow records-update

USGS Publications Warehouse

Rutledge, A.T.

1998-01-01

The computer programs included in this report can be used to develop a mathematical expression for recession of ground-water discharge and estimate mean ground-water recharge and discharge. The programs are intended for analysis of the daily streamflow record of a basin where one can reasonably assume that all, or nearly all, ground water discharges to the stream except for that which is lost to riparian evapotranspiration, and where regulation and diversion of flow can be considered to be negligible. The program RECESS determines the master reces-sion curve of streamflow recession during times when all flow can be considered to be ground-water discharge and when the profile of the ground-water-head distribution is nearly stable. The method uses a repetitive interactive procedure for selecting several periods of continuous recession, and it allows for nonlinearity in the relation between time and the logarithm of flow. The program RORA uses the recession-curve displacement method to estimate the recharge for each peak in the streamflow record. The method is based on the change in the total potential ground-water discharge that is caused by an event. Program RORA is applied to a long period of record to obtain an estimate of the mean rate of ground-water recharge. The program PART uses streamflow partitioning to estimate a daily record of base flow under the streamflow record. The method designates base flow to be equal to streamflow on days that fit a requirement of antecedent recession, linearly interpolates base flow for other days, and is applied to a long period of record to obtain an estimate of the mean rate of ground-water discharge. The results of programs RORA and PART correlate well with each other and compare reasonably with results of the corresponding manual method.

Interoperability challenges in river discharge modelling: A cross domain application scenario

NASA Astrophysics Data System (ADS)

Santoro, Mattia; Andres, Volker; Jirka, Simon; Koike, Toshio; Looser, Ulrich; Nativi, Stefano; Pappenberger, Florian; Schlummer, Manuela; Strauch, Adrian; Utech, Michael; Zsoter, Ervin

2018-06-01

River discharge is a critical water cycle variable, as it integrates all the processes (e.g. runoff and evapotranspiration) occurring within a river basin and provides a hydrological output variable that can be readily measured. Its prediction is of invaluable help for many water-related tasks including water resources assessment and management, flood protection, and disaster mitigation. Observations of river discharge are important to calibrate and validate hydrological or coupled land, atmosphere and ocean models. This requires using datasets from different scientific domains (Water, Weather, etc.). Typically, such datasets are provided using different technological solutions. This complicates the integration of new hydrological data sources into application systems. Therefore, a considerable effort is often spent on data access issues instead of the actual scientific question. This paper describes the work performed to address multidisciplinary interoperability challenges related to river discharge modeling and validation. This includes definition and standardization of domain specific interoperability standards for hydrological data sharing and their support in global frameworks such as the Global Earth Observation System of Systems (GEOSS). The research was developed in the context of the EU FP7-funded project GEOWOW (GEOSS Interoperability for Weather, Ocean and Water), which implemented a "River Discharge" application scenario. This scenario demonstrates the combination of river discharge observations data from the Global Runoff Data Centre (GRDC) database and model outputs produced by the European Centre for Medium-Range Weather Forecasts (ECMWF) predicting river discharge based on weather forecast information in the context of the GEOSS.

Recent Progress in Development of SWOT River Discharge Algorithms

NASA Astrophysics Data System (ADS)

Pavelsky, Tamlin M.; Andreadis, Konstantinos; Biancamaria, Sylvian; Durand, Michael; Moller, Dewlyn; Rodriguez, Enersto; Smith, Laurence C.

2013-09-01

The Surface Water and Ocean Topography (SWOT) Mission is a satellite mission under joint development by NASA and CNES. The mission will use interferometric synthetic aperture radar technology to continuously map, for the first time, water surface elevations and water surface extents in rivers, lakes, and oceans at high spatial resolutions. Among the primary goals of SWOT is the accurate retrieval of river discharge directly from SWOT measurements. Although it is central to the SWOT mission, discharge retrieval represents a substantial challenge due to uncertainties in SWOT measurements and because traditional discharge algorithms are not optimized for SWOT-like measurements. However, recent work suggests that SWOT may also have unique strengths that can be exploited to yield accurate estimates of discharge. A NASA-sponsored workshop convened June 18-20, 2012 at the University of North Carolina focused on progress and challenges in developing SWOT-specific discharge algorithms. Workshop participants agreed that the only viable approach to discharge estimation will be based on a slope-area scaling method such as Manning's equation, but modified slightly to reflect the fact that SWOT will estimate reach-averaged rather than cross- sectional discharge. While SWOT will provide direct measurements of some key parameters such as width and slope, others such as baseflow depth and channel roughness must be estimated. Fortunately, recent progress has suggested several algorithms that may allow the simultaneous estimation of these quantities from SWOT observations by using multitemporal observations over several adjacent reaches. However, these algorithms will require validation, which will require the collection of new field measurements, airborne imagery from AirSWOT (a SWOT analogue), and compilation of global datasets of channel roughness, river width, and other relevant variables.

Modeling of electron cyclotron resonance discharges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyyappan, M.; Govindan, T.R.

The current trend in plasma processing is the development of high density plasma sources to achieve high deposition and etch rates, uniformity over large ares, and low wafer damage. Here, is a simple model to predict the spatially-averaged plasma characteristics of electron cyclotron resonance (ECR) reactors is presented. The model consists of global conservation equations for species concentration, electron density and energy. A gas energy balance is used to predict the neutral temperature self-consistently. The model is demonstrated for an ECR argon discharge. The predicted behavior of the discharge as a function of system variables agrees well with experimental observations.

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

Wavelength Scanning with a Tilting Interference Filter for Glow-Discharge Elemental Imaging.

PubMed

Storey, Andrew P; Ray, Steven J; Hoffmann, Volker; Voronov, Maxim; Engelhard, Carsten; Buscher, Wolfgang; Hieftje, Gary M

2017-06-01

Glow discharges have long been used for depth profiling and bulk analysis of solid samples. In addition, over the past decade, several methods of obtaining lateral surface elemental distributions have been introduced, each with its own strengths and weaknesses. Challenges for each of these techniques are acceptable optical throughput and added instrumental complexity. Here, these problems are addressed with a tilting-filter instrument. A pulsed glow discharge is coupled to an optical system comprising an adjustable-angle tilting filter, collimating and imaging lenses, and a gated, intensified charge-coupled device (CCD) camera, which together provide surface elemental mapping of solid samples. The tilting-filter spectrometer is instrumentally simpler, produces less image distortion, and achieves higher optical throughput than a monochromator-based instrument, but has a much more limited tunable spectral range and poorer spectral resolution. As a result, the tilting-filter spectrometer is limited to single-element or two-element determinations, and only when the target spectral lines fall within an appropriate spectral range and can be spectrally discerned. Spectral interferences that result from heterogeneous impurities can be flagged and overcome by observing the spatially resolved signal response across the available tunable spectral range. The instrument has been characterized and evaluated for the spatially resolved analysis of glow-discharge emission from selected but representative samples.

Performance of a green propellant thruster with discharge plasma

NASA Astrophysics Data System (ADS)

Shindo, Takahiro; Wada, Asato; Maeda, Hiroshi; Watanabe, Hiroki; Takegahara, Haruki

2017-02-01

A discharge plasma was applied to initiate the combustion of a hydroxylammonium nitrate-based propellant as a substitute for the catalysts that are typically employed. The resulting thrust and thrust-to-power ratio during short interval firing tests as well as the chamber pressure with a single pulse discharge were evaluated. A 1.5-s firing test generated a maximum thrust of 322 mN along with a thrust-to-power ratio of 0.95 mN/W. During the single-pulse discharge trials, pulsed discharge capacitor energies of 5.4, 10.8, and 16.4 J were assessed, and the maximum chamber pressure was found to increase as the energy was raised. The maximum chamber pressures varied widely between experimental trials, and a 16.4-J energy value resulted in the highest chamber pressure of over 1 MPaG. The time spans between the pulsed discharge and the peak chamber pressure were in the range of 1-2 ms, representing a chamber pressure increase rate much higher than those obtained with standard catalysts.

Speckle Interferometry at Mount Wilson Observatory: Observations Obtained in 2006-2007 and 35 New Orbits

NASA Technical Reports Server (NTRS)

Hartkopf, William I.; Mason, Brian D.

2009-01-01

Results are presented for 607 speckle interferometric observations of double stars, as well as 222 measures of single stars or unresolved pairs. All data were obtained in 2006 and 2007 at the Mount Wilson Observatory, using the 2.5 m Hooker telescope. Separations range from 0.06 to 6.31, with a median of 0.34. These three observing runs concentrated on binaries in need of confirmation (mainly Hipparcos and Tycho pairs), as well as systems in need of improved orbital elements. New orbital solutions have been determined for 35 systems as a result.

Do prehospital discharge pacemaker checks provide any additional clinical benefit?

PubMed

Wheelan, Kevin R; Legge, Darlene M; Sakowski, Brent C; Bruce, Susan S; Roberts, David C; Johnston, L Murphy; Moore, B Jane; Beveridge, Thomas P; Wells, Peter J; Vallabahn, Ravi; Donsky, Michael S; Franklin, Jay O

2005-08-01

We performed a retrospective analysis of 250 records of consecutive, newly implanted, pacemaker patients from a single center to determine the rate of postimplant complications and observations discovered before and during the prehospital discharge evaluation. No observations occurred in 246 of 250 patients (98.4%) (1-sided 95% confidence interval 96.4%). Of the 250 patients, 4 had observations that were discovered at the prehospital discharge check and required reprogramming to increase the sensitivity safety margin (3 atrial and 1 ventricular). We documented only 1 complication that was discovered before the predischarge evaluation through telemetry and resulted in an atrial lead revision.

Effective Discharge and Annual Sediment Yield on Brazos River

NASA Astrophysics Data System (ADS)

Rouhnia, M.; Salehi, M.; Keyvani, A.; Ma, F.; Strom, K. B.; Raphelt, N.

2012-12-01

Geometry of an alluvial river alters dynamically over the time due to the sediment mobilization on the banks and bottom of the river channel in various flow rates. Many researchers tried to define a single representative discharge for these morphological processes such as "bank-full discharge", "effective discharge" and "channel forming discharge". Effective discharge is the flow rate in which, the most sediment load is being carried by water, in a long term period. This project is aimed to develop effective discharge estimates for six gaging stations along the Brazos River from Waco, TX to Rosharon, TX. The project was performed with cooperation of the In-stream Flow Team of the Texas Water Development Board (TWDB). Project objectives are listed as: 1) developing "Flow Duration Curves" for six stations based on mean-daily discharge by downloading the required, additional data from U.S Geological Survey website, 2) developing "Rating Curves" for six gaging stations after sampling and field measurements in three different flow conditions, 3) developing a smooth shaped "Sediment Yield Histogram" with a well distinguished peak as effective discharge. The effective discharge was calculated using two methods of manually and automatic bin selection. The automatic method is based on kernel density approximation. Cross-sectional geometry measurements, particle size distributions and water field samples were processed in the laboratory to obtain the suspended sediment concentration associated with flow rate. Rating curves showed acceptable trends, as the greater flow rate we experienced, the more sediment were carried by water.

Study on residual discharge time of lead-acid battery based on fitting method

NASA Astrophysics Data System (ADS)

Liu, Bing; Yu, Wangwang; Jin, Yueqiang; Wang, Shuying

2017-05-01

This paper use the method of fitting to discuss the data of C problem of mathematical modeling in 2016, the residual discharge time model of lead-acid battery with 20A,30A,…,100A constant current discharge is obtained, and the discharge time model of discharge under arbitrary constant current is presented. The mean relative error of the model is calculated to be about 3%, which shows that the model has high accuracy. This model can provide a basis for optimizing the adaptation of power system to the electrical motor vehicle.

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 ...

Hysterectomy - vaginal - discharge

MedlinePlus

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

[Relationships between pollutants discharge and red tide occurrence in Shenzhen eastern coast].

PubMed

Jiang, Tian-jiu; Niu, Tao; Ying, Wen-ye

2007-05-01

The study on the effects of pollutants discharge on red tide occurrence in eastern sea area of Shenzhen showed that the occurrence frequency of dinoflagellate red tide had significant positive correlations with the net discharge of total nitrogen (TN) and total phosphorous (TP) as well as the N/P ratio of the discharge. The thresholds of net discharged TN and TP were estimated to be 3.917 x 10(3) t and 2.123 x 10(4) t, respectively. No significant correlation was observed between diatom red tide and alongshore pollutants discharge. An example was given to illustrate the means of pollutants discharge control.

Auto-Detection of Partial Discharges in Power Cables by Descrete Wavelet Transform

NASA Astrophysics Data System (ADS)

Yasuda, Yoh; Hara, Takehisa; Urano, Koji; Chen, Min

One of the serious problems that may happen in power XLPE cables is destruction of insulator. The best and conventional way to prevent such a crucial accident is generally supposed to ascertain partial corona discharges occurring at small void in organic insulator. However, there are some difficulties to detect those partial discharges because of existence of external noises in detected data, whose patterns are hardly identified at a glance. By the reason of the problem, there have been a number of researches on the way of development to accomplish detecting partial discharges by employing neural network (NN) system, which is widely known as the system for pattern recognition. We have been developing the NN system of the auto-detection for partial discharges, which we actually input numerical data of waveform itself into and obtained appropriate performance from. In this paper, we employed Descrete Wavelet Transform (DWT) to acquire more detailed transformed data in order to put them into the NN system. Employing DWT, we became able to express the waveform data in time-frequency space, and achieved effective detectiton of partial discharges by NN system. We present here the results using DWT analysis for partial discharges and noise signals which we obtained actually. Moreover, we present results out of the NN system which were dealt with those transformed data.

Large discharge capacity from carbon electrodes in sulfuric acid with oxidant

NASA Astrophysics Data System (ADS)

Inagaki, M.; Iwashita, N.

The discharge performance of the graphite intercalation compounds in sulfuric acid containing nitric acid (H 2SO 4-GICs) was studied by focusing on the effects of oxidant and carbon nanotexture. A large discharge capacity from H 2SO 4-GICs synthesized by using an excess amount of HNO 3, more than 150 times of the theoretical value (93 mAh/g carbon), was obtained depending on the amount of oxidant added, the discharge current, and the nanotexture of carbon electrode. The experimental results are explained in terms of competition between the de-intercalation of sulfuric acid due to galvanostatic reduction and the re-intercalation due to chemical oxidation by HN03 during discharging. However, a subsidiary reaction decreases the effective amount of HNO 3 on the discharge by a small current and also on the cycle of chemical charging and electrochemical discharging. The oxidant KMnO 4 gave only a little larger capacity for discharge than the theoretical one, because it was reduced to the manganese oxide precipitates during the oxidation of the carbon electrode.

Understanding the distributed cognitive processes of intensive care patient discharge.

PubMed

Lin, Frances; Chaboyer, Wendy; Wallis, Marianne

2014-03-01

To better understand and identify vulnerabilities and risks in the ICU patient discharge process, which provides evidence for service improvement. Previous studies have identified that 'after hours' discharge and 'premature' discharge from ICU are associated with increased mortality. However, some of these studies have largely been retrospective reviews of various administrative databases, while others have focused on specific aspects of the process, which may miss crucial components of the discharge process. This is an ethnographic exploratory study. Distributed cognition and activity theory were used as theoretical frameworks. Ethnographic data collection techniques including informal interviews, direct observations and collecting existing documents were used. A total of 56 one-to-one interviews were conducted with 46 participants; 28 discharges were observed; and numerous documents were collected during a five-month period. A triangulated technique was used in both data collection and data analysis to ensure the research rigour. Under the guidance of activity theory and distributed cognition theoretical frameworks, five themes emerged: hierarchical power and authority, competing priorities, ineffective communication, failing to enact the organisational processes and working collaboratively to optimise the discharge process. Issues with teamwork, cognitive processes and team members' interaction with cognitive artefacts influenced the discharge process. Strategies to improve shared situational awareness are needed to improve teamwork, patient flow and resource efficiency. Tools need to be evaluated regularly to ensure their continuous usefulness. Health care professionals need to be aware of the impact of their competing priorities and ensure discharges occur in a timely manner. Activity theory and distributed cognition are useful theoretical frameworks to support healthcare organisational research. © 2013 John Wiley & Sons Ltd.

Singlet delta oxygen production in a 2D micro-discharge array in air: effect of gas residence time and discharge power

NASA Astrophysics Data System (ADS)

Nayak, Gaurav; Santos Sousa, João; Bruggeman, Peter J.

2017-03-01

The production of singlet delta oxygen (O2(a 1Δg)) is of growing interest for many applications. We report on the measurement of O2(a 1Δg) and ozone (O3) in a room temperature atmospheric pressure discharge in dry air. The plasma source is a 2D array of micro-discharges generated by an alternating current voltage at 20 kHz. The study focuses on the effect of gas flow through the discharge. The maximum investigated flow rate allows reducing the gas residence time in the discharge zone to half the discharge period. Results indicate that the residence time and discharge power have a major effect on the O2(a 1Δg) production. Different O2(a 1Δg) density dependencies on power are observed for different flow rates. Effects of collisional quenching on the as-produced and measured O2(a 1Δg) densities are discussed. The flow rate also allows for control of the O2(a 1Δg) to O3 density ratio in the effluent from 0.7 to conditions of pure O3.

Characterizing the SWOT discharge error budget on the Sacramento River, CA

NASA Astrophysics Data System (ADS)

Yoon, Y.; Durand, M. T.; Minear, J. T.; Smith, L.; Merry, C. J.

2013-12-01

The Surface Water and Ocean Topography (SWOT) is an upcoming satellite mission (2020 year) that will provide surface-water elevation and surface-water extent globally. One goal of SWOT is the estimation of river discharge directly from SWOT measurements. SWOT discharge uncertainty is due to two sources. First, SWOT cannot measure channel bathymetry and determine roughness coefficient data necessary for discharge calculations directly; these parameters must be estimated from the measurements or from a priori information. Second, SWOT measurement errors directly impact the discharge estimate accuracy. This study focuses on characterizing parameter and measurement uncertainties for SWOT river discharge estimation. A Bayesian Markov Chain Monte Carlo scheme is used to calculate parameter estimates, given the measurements of river height, slope and width, and mass and momentum constraints. The algorithm is evaluated using simulated both SWOT and AirSWOT (the airborne version of SWOT) observations over seven reaches (about 40 km) of the Sacramento River. The SWOT and AirSWOT observations are simulated by corrupting the ';true' HEC-RAS hydraulic modeling results with the instrument error. This experiment answers how unknown bathymetry and roughness coefficients affect the accuracy of the river discharge algorithm. From the experiment, the discharge error budget is almost completely dominated by unknown bathymetry and roughness; 81% of the variance error is explained by uncertainties in bathymetry and roughness. Second, we show how the errors in water surface, slope, and width observations influence the accuracy of discharge estimates. Indeed, there is a significant sensitivity to water surface, slope, and width errors due to the sensitivity of bathymetry and roughness to measurement errors. Increasing water-surface error above 10 cm leads to a corresponding sharper increase of errors in bathymetry and roughness. Increasing slope error above 1.5 cm/km leads to a

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li Xuechen; Niu Dongying; Yin Zengqian

2012-08-15

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 ionmore » 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.« less

Optimization of gas-filled quartz capillary discharge waveguide for high-energy laser wakefield acceleration

NASA Astrophysics Data System (ADS)

Qin, Zhiyong; Li, Wentao; Liu, Jiansheng; Liu, Jiaqi; Yu, Changhai; Wang, Wentao; Qi, Rong; Zhang, Zhijun; Fang, Ming; Feng, Ke; Wu, Ying; Ke, Lintong; Chen, Yu; Wang, Cheng; Li, Ruxin; Xu, Zhizhan

2018-04-01

A hydrogen-filled capillary discharge waveguide made of quartz is presented for high-energy laser wakefield acceleration (LWFA). The experimental parameters (discharge current and gas pressure) were optimized to mitigate ablation by a quantitative analysis of the ablation plasma density inside the hydrogen-filled quartz capillary. The ablation plasma density was obtained by combining a spectroscopic measurement method with a calibrated gas transducer. In order to obtain a controllable plasma density and mitigate the ablation as much as possible, the range of suitable parameters was investigated. The experimental results demonstrated that the ablation in the quartz capillary could be mitigated by increasing the gas pressure to ˜7.5-14.7 Torr and decreasing the discharge current to ˜70-100 A. These optimized parameters are promising for future high-energy LWFA experiments based on the quartz capillary discharge waveguide.

Concussion - adults - discharge

MedlinePlus

Brain injury - concussion - discharge; Traumatic brain injury - concussion - discharge; Closed head injury - concussion - discharge ... Barth JT, Broshek DK, Freeman JR. Concussion and brain injury. In: Miller MD, Thompson SR, eds. DeLee ...

Battery materials for ultrafast charging and discharging.

PubMed

Kang, Byoungwoo; Ceder, Gerbrand

2009-03-12

The storage of electrical energy at high charge and discharge rate is an important technology in today's society, and can enable hybrid and plug-in hybrid electric vehicles and provide back-up for wind and solar energy. It is typically believed that in electrochemical systems very high power rates can only be achieved with supercapacitors, which trade high power for low energy density as they only store energy by surface adsorption reactions of charged species on an electrode material. Here we show that batteries which obtain high energy density by storing charge in the bulk of a material can also achieve ultrahigh discharge rates, comparable to those of supercapacitors. We realize this in LiFePO(4) (ref. 6), a material with high lithium bulk mobility, by creating a fast ion-conducting surface phase through controlled off-stoichiometry. A rate capability equivalent to full battery discharge in 10-20 s can be achieved.

Concentration-discharge relationships reflect chemostatic characteristics of US catchments

USGS Publications Warehouse

Godsey, S.E.; Kirchner, J.W.; Clow, D.W.

2009-01-01

Concentration-discharge relationships have been widely used as clues to the hydrochemical processes that control runoff chemistry. Here we examine concentration-discharge relationships for solutes produced primarily by mineral weathering in 59 geochemically diverse US catchments. We show that these catchments exhibit nearly chemostatic behaviour; their stream concentrations of weathering products such as Ca, Mg, Na, and Si typically vary by factors of only 3 to 20 while discharge varies by several orders of magnitude. Similar patterns are observed at the inter-annual time scale. This behaviour implies that solute concentrations in stream water are not determined by simple dilution of a fixed solute flux by a variable flux of water, and that rates of solute production and/or mobilization must be nearly proportional to water fluxes, both on storm and inter-annual timescales. We compared these catchments' concentration-discharge relationships to the predictions of several simple hydrological and geochemical models. Most of these models can be forced to approximately fit the observed concentration-discharge relationships, but often only by assuming unrealistic or internally inconsistent parameter values. We propose a new model that also fits the data and may be more robust. We suggest possible tests of the new model for future studies. The relative stability of concentration under widely varying discharge may help make aquatic environments habitable. It also implies that fluxes of weathering solutes in streams, and thus fluxes of alkalinity to the oceans, are determined primarily by water fluxes. Thus, hydrology may be a major driver of the ocean-alkalinity feedback regulating climate change. Copyright ?? 2009 John Wiley & Sons, Ltd.

Acceleration processes in the quasi-steady magnetoplasmadynamic discharge. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Boyle, M. J.

1974-01-01

The flow field characteristics within the discharge chamber and exhaust of a quasi-steady magnetoplasmadynamic (MPD) arcjet were examined to clarify the nature of the plasma acceleration process. The observation of discharge characteristics unperturbed by insulator ablation and terminal voltage fluctuations, first requires the satisfaction of three criteria: the use of refractory insulator materials; a mass injection geometry tailored to provide propellant to both electrode regions of the discharge; and a cathode of sufficient surface area to permit nominal MPD arcjet operation for given combinations of arc current and total mass flow. The axial velocity profile and electromagnetic discharge structure were measured for an arcjet configuration which functions nominally at 15.3 kA and 6 g/sec argon mass flow. An empirical two-flow plasma acceleration model is advanced which delineates inner and outer flow regions and accounts for the observed velocity profile and calculated thrust of the accelerator.

Nonuniformity of the chemical composition of a capillary discharge plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kocharyan, A. E.; Bobrova, N. A.; Sasorov, P. V.

A steady-state distribution of the concentration of two ion species in a capillary discharge plasma is studied using MHD equations for a plasma with a spatially nonuniform, time-dependent chemical composition. In our case, the set of equations is significantly simplified because of the steady-state character and symmetry of the problem. Even with such simplification, however, some results could be obtained only by numerical integration. The factors affecting the distribution of heavy ions are studied. It is shown that the distribution of the heavy impurity over the discharge cross section can be much more nonuniform than the distribution of the mainmore » component (hydrogen). A simple criterion for such a nonuniformity is obtained.« less

Multicriteria evaluation of discharge simulation in Dynamic Global Vegetation Models

NASA Astrophysics Data System (ADS)

Yang, Hui; Piao, Shilong; Zeng, Zhenzhong; Ciais, Philippe; Yin, Yi; Friedlingstein, Pierre; Sitch, Stephen; Ahlström, Anders; Guimberteau, Matthieu; Huntingford, Chris; Levis, Sam; Levy, Peter E.; Huang, Mengtian; Li, Yue; Li, Xiran; Lomas, Mark R.; Peylin, Philippe; Poulter, Ben; Viovy, Nicolas; Zaehle, Soenke; Zeng, Ning; Zhao, Fang; Wang, Lei

2015-08-01

In this study, we assessed the performance of discharge simulations by coupling the runoff from seven Dynamic Global Vegetation Models (DGVMs; LPJ, ORCHIDEE, Sheffield-DGVM, TRIFFID, LPJ-GUESS, CLM4CN, and OCN) to one river routing model for 16 large river basins. The results show that the seasonal cycle of river discharge is generally modeled well in the low and middle latitudes but not in the high latitudes, where the peak discharge (due to snow and ice melting) is underestimated. For the annual mean discharge, the DGVMs chained with the routing model show an underestimation. Furthermore, the 30 year trend of discharge is also underestimated. For the interannual variability of discharge, a skill score based on overlapping of probability density functions (PDFs) suggests that most models correctly reproduce the observed variability (correlation coefficient higher than 0.5; i.e., models account for 50% of observed interannual variability) except for the Lena, Yenisei, Yukon, and the Congo river basins. In addition, we compared the simulated runoff from different simulations where models were forced with either fixed or varying land use. This suggests that both seasonal and annual mean runoff has been little affected by land use change but that the trend itself of runoff is sensitive to land use change. None of the models when considered individually show significantly better performances than any other and in all basins. This suggests that based on current modeling capability, a regional-weighted average of multimodel ensemble projections might be appropriate to reduce the bias in future projection of global river discharge.

Atmospheric negative corona discharge using a Taylor cone as liquid electrode

NASA Astrophysics Data System (ADS)

Sekine, Ryuto; Shirai, Naoki; Uchida, Satoshi; Tochikubo, Fumiyoshi

2012-10-01

We examined characteristics of atmospheric negative corona discharge using liquid needle cathode. As a liquid needle cathode, we adopted Taylor cone with conical shape. A nozzle with inner diameter of 10 mm is filled with liquid, and a plate electrode is placed at 10 mm above the nozzle. By applying a dc voltage between electrodes, Taylor cone is formed. To change the liquid property, we added sodium dodecyl sulfate to reduce the surface tension, sodium sulfate to increase the conductivity, and polyvinyl alcohol to increase the viscosity, in distilled water. The liquid, with high surface tension such as pure water could not form a Taylor cone. When we reduced surface tension, a Taylor cone was formed and the stable corona discharge was observed at the tip of the cone. When we increased viscosity, a liquid filament protruded from the solution surface was formed and corona discharge was observed along the filament at position 0.7-1.0 mm above from the tip of the cone. Increasing the conductivity resulted in the higher light intensity of corona and the lower corona onset voltage. When we use the metal needle electrode, the corona discharge depends on the voltage and the gap length. Using Taylor cone, different types of discharges were observed by changing the property of the liquid.

Characteristics of sediment discharge in the subarctic Yukon River, Alaska

USGS Publications Warehouse

Chikita, K.A.; Kemnitz, R.; Kumai, R.

2002-01-01

The characteristics of sediment discharge in the Yukon River, Alaska were investigated by monitoring water discharge, water turbidity and water temperature. The river-transported sediment, 90 wt.% or more, consists of silt and clay (grain size ??? 62.5 ??m), which probably originated in the glacier-covered mountains mostly in the Alaska Range. For early June to late August 1999, we continuously measured water turbidity and temperature near the estuary and in the middle of Yukon River by using self-recording turbidimeters and temperature data loggers. The water turbidity (ppm) was converted to suspended sediment concentration (SSC; mg/l) of river water, using a relation between simultaneous turbidity and SSC at each of the two sites, and then, the suspended sediment discharge, approximately equal to water discharge times SSC, was numerically obtained every 1 or 2 h. It should be noted that the sediment discharge in the Yukon River is controlled by SSC rather than water discharge. As a result, a peak sediment discharge occurred in mid or late August by local sediment runoffs due to glacier-melt (or glacier-melt plus rainfall), while a peak water discharge was produced by snowmelt in late June or early July. Application of the "extended Shields diagram" indicates that almost all the river-transported sediments are under complete suspension. ?? 2002 Elsevier Science B.V. All rights reserved.

SPECTROSOCPIC STUDIES OF IONIZATION IN A HOLLOW-CATHODE DISCHARGE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchell, K.B.

1961-08-01

The influence of carrier gas, carrier gas pressure, cathode geometry, and discharge current on the ionization of metal atoms in a hollow-cathode discharge was studied in some detail. Most of these studies were raade with an iron hollowcathode discharge. A measure of ionization was obtained from the intensity ratio of a line of the second to a line of the first spectrum. In general, this ratio was found to increase with carrier gas pressure and discharge current. This ratio also increased with increasing cathode bcre diameter but decreased with increasing bcre length. This ratio for iron was greatly affected bymore » the use of different inert carrier gases. Of the five common inert gases used, xenon produced the largest value for this ratio and argon produced the smallest. The results of these studies indicated this may be a new method for distinguishing between lines emitted by the neutral atom and lines of the singly ionized atom. (auth)« less

Simulation of ground-water discharge to Biscayne Bay, southeastern Florida

USGS Publications Warehouse

Langevin, Christian David

2001-01-01

As part of the Place-Based Studies Program, the U.S. Geological Survey initiated a project in 1996, in cooperation with the U.S. Army Corps of Engineers, to quantify the rates and patterns of submarine ground-water discharge to Biscayne Bay. Project objectives were achieved through field investigations at three sites (Coconut Grove, Deering Estate, and Mowry Canal) along the coastline of Biscayne Bay and through the development and calibration of variable-density, ground-water flow models. Two-dimensional, vertical cross-sectional models were developed for steady-state conditions for the Coconut Grove and Deering Estate transects to quantify local-scale ground-water discharge patterns to Biscayne Bay. A larger regional-scale model was developed in three dimensions to simulate submarine ground-water discharge to the entire bay. The SEAWAT code, which is a combined version of MODFLOW and MT3D, was used to simulate the complex variable-density flow patterns. Field data suggest that ground-water discharge to Biscayne Bay relative to the shoreline is restricted to within 300 meters at Coconut Grove, 600 to 1,000 meters at Deering Estate, and 100 meters at Mowry Canal. The vertical cross-sectional models, which were calibrated to the field data using the assumption of steady state, tend to focus ground-water discharge to within 50 to 200 meters of the shoreline. With homogeneous distributions for aquifer parameters and a constant-concentration boundary for Biscayne Bay, the numerical models could not reproduce the lower ground-water salinities observed beneath the bay, which suggests that further research may be necessary to improve the accuracy of the numerical simulations. Results from the cross-sectional models, which were able to simulate the approximate position of the saltwater interface, suggest that longitudinal dispersivity ranges between 1 and 10 meters, and transverse dispersivity ranges from 0.1 to 1 meter for the Biscayne aquifer. The three

Statistical Characteristics of the Gaussian-Noise Spikes Exceeding the Specified Threshold as Applied to Discharges in a Thundercloud

NASA Astrophysics Data System (ADS)

Klimenko, V. V.

2017-12-01

We obtain expressions for the probabilities of the normal-noise spikes with the Gaussian correlation function and for the probability density of the inter-spike intervals. As distinct from the delta-correlated noise, in which the intervals are distributed by the exponential law, the probability of the subsequent spike depends on the previous spike and the interval-distribution law deviates from the exponential one for a finite noise-correlation time (frequency-bandwidth restriction). This deviation is the most pronounced for a low detection threshold. Similarity of the behaviors of the distributions of the inter-discharge intervals in a thundercloud and the noise spikes for the varying repetition rate of the discharges/spikes, which is determined by the ratio of the detection threshold to the root-mean-square value of noise, is observed. The results of this work can be useful for the quantitative description of the statistical characteristics of the noise spikes and studying the role of fluctuations for the discharge emergence in a thundercloud.

Angioplasty and stent - heart - discharge

MedlinePlus

Drug-eluting stents - discharge; PCI - discharge; Percutaneous coronary intervention - discharge; Balloon angioplasty - discharge; Coronary angioplasty - discharge; Coronary artery angioplasty - discharge; Cardiac ...

Initial results from the NASA Lewis Bumpy Torus experiment. [of steady-state ion heating method based on modified Penning discharge

NASA Technical Reports Server (NTRS)

Roth, J. R.; Richardson, R. W.; Gerdin, G. A.

1973-01-01

Initial results were obtained from low power operation of the NASA Lewis Bumpy Torus experiment, in which a steady-state ion heating method based on the modified Penning discharge is applied in a bumpy torus confinement geometry. The magnet facility consists of 12 superconducting coils, each 19 cm i.d. and capable of 3.0 T, equally spaced in a toroidal array 1.52 m in major diameter. A 18 cm i.d. anode ring is located at each of the 12 midplanes and is maintained at high positive potentials by a dc power supply. Initial observations indicate electron temperatures from 10 to 150 eV, and ion kinetic temperatures from 200 eV to 1200 eV. Two modes of operation were observed, which depend on background pressure, and have different radial density profiles. Steady state neutron production was observed. The ion heating process in the bumpy torus appears to parallel closely the mechanism observed when the modified Penning discharge was operated in a simple magnetic mirror field.

Refractive corneal surgery - discharge

MedlinePlus

Nearsightedness surgery - discharge; Refractive surgery - discharge; LASIK - discharge; PRK - discharge ... November 27, 2017. Garg S, McColgin AZ, Steinert RF. LASIK. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology . ...

Plasma Methods of Obtainment of Multifunctional Composite Materials, Dispersion-Hardened by Nanoparticles

NASA Astrophysics Data System (ADS)

Sizonenko, O. N.; Grigoryev, E. G.; Pristash, N. S.; Zaichenko, A. D.; Torpakov, A. S.; Lypian, Ye. V.; Tregub, V. A.; Zholnin, A. G.; Yudin, A. V.; Kovalenko, A. A.

2017-09-01

High voltage electric discharge (HVED) in disperse system "hydrocarbon liquid - powder" due to impact of plasma discharge channel, electromagnetic fields, shock waves mechanical impact, hydro flows and volume microcavitation leads to synthesis of nanocarbon, metal powders dispersion and synthesis of micro- (from 10-6 to 10-7 m) and nanosized (from 10-7 to 10-9 m) composite powders of hardening phases. Spark plasma sintering (SPS) of powder mixtures allows targeted control of grain growth rate and thus allows obtainment of multifunctional composite materials dispersion hardened by nanoparticles. Processes of HVED synthesis of micro- and nanosized powders of new compositions from elemental metal powders and their mixtures with the subsequent application of high-speed SPS of obtained powders create conditions for increase of strength (by 10-20 %), hardness and wear-resistance (by 30-60 %) of obtained materials.

Temporal variability in stage-discharge relationships

NASA Astrophysics Data System (ADS)

Guerrero, José-Luis; Westerberg, Ida K.; Halldin, Sven; Xu, Chong-Yu; Lundin, Lars-Christer

2012-06-01

discharge volumes derived from static and dynamic curves was largest for sub-daily ratings but stayed large also for monthly and yearly totals. The relative uncertainty was largest for low flows but it was considerable also for intermediate and large flows. The standard procedure of adjusting rating curves when calculated and observed discharge differ by more than 5% would have required continuously updated rating curves at the studied locations. We believe that these findings can be applicable to many other discharge stations around the globe.

Continuous wavelet transform based time-scale and multifractal analysis of the nonlinear oscillations in a hollow cathode glow discharge plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nurujjaman, Md.; Narayanan, Ramesh; Iyengar, A. N. Sekar

2009-10-15

Continuous wavelet transform (CWT) based time-scale and multifractal analyses have been carried out on the anode glow related nonlinear floating potential fluctuations in a hollow cathode glow discharge plasma. CWT has been used to obtain the contour and ridge plots. Scale shift (or inversely frequency shift), which is a typical nonlinear behavior, has been detected from the undulating contours. From the ridge plots, we have identified the presence of nonlinearity and degree of chaoticity. Using the wavelet transform modulus maxima technique we have obtained the multifractal spectrum for the fluctuations at different discharge voltages and the spectrum was observed tomore » become a monofractal for periodic signals. These multifractal spectra were also used to estimate different quantities such as the correlation and fractal dimension, degree of multifractality, and complexity parameters. These estimations have been found to be consistent with the nonlinear time series analysis.« less

Understanding the occupational and organizational boundaries to safe hospital discharge.

PubMed

Waring, Justin; Marshall, Fiona; Bishop, Simon

2015-01-01

Safe hospital discharge relies upon communication and coordination across multiple occupational and organizational boundaries. Our aim was to understand how these boundaries can exacerbate health system complexity and represent latent sociocultural threats to safe discharge. An ethnographic study was conducted in two local health and social care systems (health economies) in England, focusing on two clinical areas: stroke and hip fracture patients. Data collection involved 345 hours of observations and 220 semi-structured interviews with health and social care professionals, patients and their lay carers. Hospital discharge involves a dynamic network of interactions between heterogeneous health and social care actors, each characterized by divergent ways of organizing discharge activities; cultures of collaboration and interaction and understanding of what discharge involves and how it contributes to patient recovery. These interrelated dimensions elaborate the occupational and organisational boundaries that can influence communication and coordination in hospital discharge. Hospital discharge relies upon the coordination of multiple actors working across occupational and organizational boundaries. Attention to the sociocultural boundaries that influence communication and coordination can help inform interventions that might support enhanced discharge safety. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Dusty waves and vortices in rf magnetron discharge plasma

NASA Astrophysics Data System (ADS)

Filippov, A. V.; Pal, A. F.; Ryabinkin, A. N.; Serov, A. O.; Shugaev, F. V.

2018-01-01

The appearance and subsequent growth of metallic particles in plasma of planar rf magnetron sputter were observed. The origin of the particles is sputtering of the rf electrode by ion flux from the plasma. In some regions of formed dust cloud the particles were involved in the horizontal or vertical circular movement. The horizontal rotation along the sputtered track in the cyclotron drift direction was observed close to the main magnetron plasma. The torus-shaped dust vortex ring engirdled the secondary plasma of the discharge at height of a few centimeters over the electrode. Close to this region particle density waves propagated through the cloud. The possible role of discharge plasma azimuthal inhomogeneity and gas dynamics effects in the forming the observed structures was considered.

[Determination of electric field distribution in dielectric barrier surface glow discharge by spectroscopic method].

PubMed

Li, Xue-chen; Jia, Peng-ying; Liu, Zhi-hui; Li, Li-chun; Dong, Li-fang

2008-12-01

In the present paper, stable glow discharges were obtained in air at low pressure with a dielectric barrier surface discharge device. Light emission from the discharge was detected by photomultiplier tubes and the research results show that the light signal exhibited one discharge pulse per half cycle of the applied voltage. The light pulses were asymmetric between the positive half cycle and the negative one of the applied voltage. The images of the glow surface discharge were processed by Photoshop software and the results indicate that the emission intensity remained almost constant for different places with the same distance from the powered electrode, while the emission intensity decreased with the distance from the powered electrode increasing. In dielectric barrier discharge, net electric field is determined by the applied voltage and the wall charges accumulated on the dielectric layer during the discharge, and consequently, it is important to obtain information about the net electric field distribution. For this purpose, optical emission spectroscopy method was used. The distribution of the net electric field can be deduced from the intensity ratio of spectral line 391.4 nm emitted from the first negative system of N2+ (B 2sigma u+ -->X 2sigma g+) to 337.1 nm emitted from the second positive system of N2 (C 3IIu-B 3IIg). The research results show that the electric field near the powered electric field is higher than at the edge of the discharge. These experimental results are very important for numerical study and industrial application of the surface discharge.

Study of Saturn Electrostatic Discharges in a Wide Range of Timec SCALES

NASA Astrophysics Data System (ADS)

Mylostna, K.; Zakharenko, V.; Konovalenko, A.; Kolyadin, V.; Zarka, P.; Griemeier, J.-M.; Litvinenko, G.; Sidorchuk, M.; Rucker, H.; Fischer, G.; Cecconi, B.; Coffre, A.; Denis, L.; Nikolaenko, V.; Shevchenko, V.

Saturn Electrostatic discharges (SED) are sporadic broadband impulsive radio bursts associated with lightning in Saturnian atmosphere. After 25 years of space investigations in 2006 the first successful observations of SED on the UTR-2 radio telescope were carried out [1]. Since 2007 a long-term program of ED search and study in the Solar system has started. As a part of this program the unique observations with high time resolution were taken in 2010. New possibilities of UTR-2 radio telescope allowed to provide a long-period observations and study with high temporal resolution. This article presents the results of SED study in a wide range of time scales: from seconds to microseconds. For the first time there were obtained a low frequency spectrum of SED. We calculated flux densities of individual bursts at the maximum achievable time resolution. Flux densities of most intensive bursts reach 4200 Jy.

34 CFR 685.214 - Closed school discharge.

Code of Federal Regulations, 2013 CFR

2013-07-01

... program of study through a teach-out at another school or by transferring academic credits or hours earned... section and to transfer any right to recovery against a third party to the Secretary in accordance with... obtain the discharge. (e) Transfer to the Secretary of borrower's right of recovery against third parties...

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.

Accelerated discharge within 72 hours of colorectal cancer resection using simple discharge criteria.

PubMed

Emmanuel, A; Chohda, E; Botfield, C; Ellul, J

2018-01-01

Introduction Short hospital stays and accelerated discharge within 72 hours following colorectal cancer resections have not been widely achieved. Series reporting on accelerated discharge involve heterogeneous patient populations and exclude important groups. Strict adherence to some discharge requirements may lead to delays in discharge. The aim of this study was to evaluate the safety and feasibility of accelerated discharge within 72 hours of all elective colorectal cancer resections using simple discharge criteria. Methods Elective colorectal cancer resections performed between August 2009 and December 2015 by a single surgeon were reviewed. Perioperative care was based on an enhanced recovery programme. A set of simplified discharge criteria were used. Outcomes including postoperative complications, readmissions and reoperations were compared between patients discharged within 72 hours and those with a longer postoperative stay. Results Overall, 256 colorectal cancer resections (90% laparoscopic) were performed. The mean patient age was 70.8 years. The median length of stay was 3 days. Fifty-eight per cent of all patients and sixty-three per cent of patients undergoing laparoscopic surgery were discharged within 72 hours. Accelerated discharge was not associated with adverse outcomes compared with delayed discharge. Patients discharged within 72 hours had significantly fewer postoperative complications, readmissions and reoperations. Open surgery and stoma formation were associated with discharge after 72 hours but not age, co-morbidities, neoadjuvant chemoradiation or surgical procedure. Conclusions Accelerated discharge within 72 hours of elective colorectal resection for cancer is safely achievable for the majority of patients without compromising short-term outcomes.

Gastric bypass surgery - discharge

MedlinePlus

... bypass - discharge; Gastric bypass - Roux-en-Y - discharge; Obesity gastric bypass discharge; Weight loss - gastric bypass discharge ... al. Bariatric surgery versus non-surgical treatment for obesity: a systematic review and meta-analysis of randomised ...

Estimation of peak discharge quantiles for selected annual exceedance probabilities in northeastern Illinois

USGS Publications Warehouse

Over, Thomas M.; Saito, Riki J.; Veilleux, Andrea G.; Sharpe, Jennifer B.; Soong, David T.; Ishii, Audrey L.

2016-06-28

This report provides two sets of equations for estimating peak discharge quantiles at annual exceedance probabilities (AEPs) of 0.50, 0.20, 0.10, 0.04, 0.02, 0.01, 0.005, and 0.002 (recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years, respectively) for watersheds in Illinois based on annual maximum peak discharge data from 117 watersheds in and near northeastern Illinois. One set of equations was developed through a temporal analysis with a two-step least squares-quantile regression technique that measures the average effect of changes in the urbanization of the watersheds used in the study. The resulting equations can be used to adjust rural peak discharge quantiles for the effect of urbanization, and in this study the equations also were used to adjust the annual maximum peak discharges from the study watersheds to 2010 urbanization conditions.The other set of equations was developed by a spatial analysis. This analysis used generalized least-squares regression to fit the peak discharge quantiles computed from the urbanization-adjusted annual maximum peak discharges from the study watersheds to drainage-basin characteristics. The peak discharge quantiles were computed by using the Expected Moments Algorithm following the removal of potentially influential low floods defined by a multiple Grubbs-Beck test. To improve the quantile estimates, regional skew coefficients were obtained from a newly developed regional skew model in which the skew increases with the urbanized land use fraction. The drainage-basin characteristics used as explanatory variables in the spatial analysis include drainage area, the fraction of developed land, the fraction of land with poorly drained soils or likely water, and the basin slope estimated as the ratio of the basin relief to basin perimeter.This report also provides the following: (1) examples to illustrate the use of the spatial and urbanization-adjustment equations for estimating peak discharge quantiles at ungaged

ELECTRODYNAMICS OF AXISYMMETRIC PULSAR MAGNETOSPHERE WITH ELECTRON-POSITRON DISCHARGE: A NUMERICAL EXPERIMENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Alexander Y.; Beloborodov, Andrei M., E-mail: amb@phys.columbia.edu

2014-11-01

We present the first self-consistent global simulations of pulsar magnetospheres with operating e {sup ±} discharge. We focus on the simple configuration of an aligned or anti-aligned rotator. The star is spun up from a zero (vacuum) state to a high angular velocity, and we follow the coupled evolution of its external electromagnetic field and plasma particles using the ''particle-in-cell'' method. A plasma magnetosphere begins to form through the extraction of particles from the star; these particles are accelerated by the rotation-induced electric field, producing curvature radiation and igniting e {sup ±} discharge. We follow the system evolution for severalmore » revolution periods, longer than required to reach a quasi-steady state. Our numerical experiment puts to test previous ideas for the plasma flow and gaps in the pulsar magnetosphere. We first consider rotators capable of producing pairs out to the light cylinder through photon-photon collisions. We find that their magnetospheres are similar to the previously obtained force-free solutions with a Y-shaped current sheet. The magnetosphere continually ejects e {sup ±} pairs and ions. Pair creation is sustained by a strong electric field along the current sheet. We observe powerful curvature and synchrotron emission from the current sheet, consistent with Fermi observations of gamma-ray pulsars. We then study pulsars that can only create pairs in the strong-field region near the neutron star, well inside the light cylinder. We find that both aligned and anti-aligned rotators relax to the ''dead'' state with suppressed pair creation and electric currents, regardless of the discharge voltage.« less

Thyroid gland removal - discharge

MedlinePlus

... tingling in your face or lips Alternative Names Total thyroidectomy - discharge; Partial thyroidectomy - discharge; Thyroidectomy - discharge; Subtotal thyroidectomy - discharge References Lai SY, Mandel SJ, Weber RS. Management of thyroid neoplasms. In: Flint PW, Haughey BH, ...

Cirrhosis - discharge

MedlinePlus

Liver failure - discharge; Liver cirrhosis - discharge ... You have cirrhosis of the liver. Scar tissue forms and your liver gets smaller and harder. Most of the time, this damage cannot be undone. However, the ...

Nested-scale discharge and groundwater level monitoring to improve predictions of flow route discharges and nitrate loads

NASA Astrophysics Data System (ADS)

van der Velde, Y.; Rozemeijer, J. C.; de Rooij, G. H.; van Geer, F. C.; Torfs, P. J. J. F.; de Louw, P. G. B.

2010-10-01

Identifying effective measures to reduce nutrient loads of headwaters in lowland catchments requires a thorough understanding of flow routes of water and nutrients. In this paper we assess the value of nested-scale discharge and groundwater level measurements for predictions of catchment-scale discharge and nitrate loads. In order to relate field-site measurements to the catchment-scale an upscaling approach is introduced that assumes that scale differences in flow route fluxes originate from differences in the relationship between groundwater storage and the spatial structure of the groundwater table. This relationship is characterized by the Groundwater Depth Distribution (GDD) curve that relates spatial variation in groundwater depths to the average groundwater depth. The GDD-curve was measured for a single field site (0.009 km2) and simple process descriptions were applied to relate the groundwater levels to flow route discharges. This parsimonious model could accurately describe observed storage, tube drain discharge, overland flow and groundwater flow simultaneously with Nash-Sutcliff coefficients exceeding 0.8. A probabilistic Monte Carlo approach was applied to upscale field-site measurements to catchment scales by inferring scale-specific GDD-curves from hydrographs of two nested catchments (0.4 and 6.5 km2). The estimated contribution of tube drain effluent (a dominant source for nitrates) decreased with increasing scale from 76-79% at the field-site to 34-61% and 25-50% for both catchment scales. These results were validated by demonstrating that a model conditioned on nested-scale measurements simulates better nitrate loads and better predictions of extreme discharges during validation periods compared to a model that was conditioned on catchment discharge only.

Fresh-water discharge salinity relations in the tidal Delaware River

USGS Publications Warehouse

Keighton, Walter B.

1966-01-01

Sustained flows of fresh water greater than 3,500, 4,400, and 5,300 cubic feet per second into the Delaware River estuary at Trenton, NJ assure low salinity at League Island, Eddystone, and Marcus Hook, respectively. When the discharge at Trenton is less than these critical values, salinity is very sensitive to change in discharge, so that a relatively small decrease in fresh-water discharge results in a relatively great increase in salinity. Comparison of the discharge-salinity relations observed for the 14-year period August 1949-December 1963 with relations proposed by other workers but based on other time periods indicate that such relations change with time and that salinity is affected not only by discharge but also by dredging; construction of breakwater, dikes, and tidal barriers; changing sea level; tidal elevation; tidal range; and wind intensity and direction.

Bayesian analysis of stage-fall-discharge rating curves and their uncertainties

NASA Astrophysics Data System (ADS)

Mansanarez, Valentin; Le Coz, Jérôme; Renard, Benjamin; Lang, Michel; Pierrefeu, Gilles; Le Boursicaud, Raphaël; Pobanz, Karine

2016-04-01

Stage-fall-discharge (SFD) rating curves are traditionally used to compute streamflow records at sites where the energy slope of the flow is variable due to variable backwater effects. Building on existing Bayesian approaches, we introduce an original hydraulics-based method for developing SFD rating curves used at twin gauge stations and estimating their uncertainties. Conventional power functions for channel and section controls are used, and transition to a backwater-affected channel control is computed based on a continuity condition, solved either analytically or numerically. The difference between the reference levels at the two stations is estimated as another uncertain parameter of the SFD model. The method proposed in this presentation incorporates information from both the hydraulic knowledge (equations of channel or section controls) and the information available in the stage-fall-discharge observations (gauging data). The obtained total uncertainty combines the parametric uncertainty and the remnant uncertainty related to the model of rating curve. This method provides a direct estimation of the physical inputs of the rating curve (roughness, width, slope bed, distance between twin gauges, etc.). The performance of the new method is tested using an application case affected by the variable backwater of a run-of-the-river dam: the Rhône river at Valence, France. In particular, a sensitivity analysis to the prior information and to the gauging dataset is performed. At that site, the stage-fall-discharge domain is well documented with gaugings conducted over a range of backwater affected and unaffected conditions. The performance of the new model was deemed to be satisfactory. Notably, transition to uniform flow when the overall range of the auxiliary stage is gauged is correctly simulated. The resulting curves are in good agreement with the observations (gaugings) and their uncertainty envelopes are acceptable for computing streamflow records. Similar

Riverine discharges to Chesapeake Bay: Analysis of long-term (1927–2014) records and implications for future flows in the Chesapeake Bay basin

USGS Publications Warehouse

Rice, Karen; Moyer, Douglas; Mills, Aaron L.

2017-01-01

The Chesapeake Bay (CB) basin is under a total maximum daily load (TMDL) mandate to reduce nitrogen, phosphorus, and sediment loads to the bay. Identifying shifts in the hydro-climatic regime may help explain observed trends in water quality. To identify potential shifts, hydrologic data (1927–2014) for 27 watersheds in the CB basin were analyzed to determine the relationships among long-term precipitation and stream discharge trends. The amount, frequency, and intensity of precipitation increased from 1910 to 1996 in the eastern U.S., with the observed increases greater in the northeastern U.S. than the southeastern U.S. The CB watershed spans the north-to-south gradient in precipitation increases, and hydrologic differences have been observed in watersheds north relative to watersheds south of the Pennsylvania—Maryland (PA-MD) border. Time series of monthly mean precipitation data specific to each of 27 watersheds were derived from the Precipitation-elevation Regression on Independent Slopes Model (PRISM) dataset, and monthly mean stream-discharge data were obtained from U.S. Geological Survey streamgage records. All annual precipitation trend slopes in the 18 watersheds north of the PA-MD border were greater than or equal to those of the nine south of that border. The magnitude of the trend slopes for 1927–2014 in both precipitation and discharge decreased in a north-to-south pattern. Distributions of the monthly precipitation and discharge datasets were assembled into percentiles for each year for each watershed. Multivariate correlation of precipitation and discharge within percentiles among the groups of northern and southern watersheds indicated only weak associations. Regional-scale average behaviors of trends in the distribution of precipitation and discharge annual percentiles differed between the northern and southern watersheds. In general, the linkage between precipitation and discharge was weak, with the linkage weaker in the northern watersheds

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.

Nipple Discharge

MedlinePlus

... breast-feeding. It also may be associated with menstrual hormone changes and fibrocystic changes. The milky discharge ... that requires treatment. If you're still having menstrual periods and your nipple discharge doesn't resolve ...

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 infections White, cottage cheese-like discharge Swelling and ...

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.

Time evolution of nanosecond runaway discharges in air and helium at atmospheric pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yatom, S.; Vekselman, V.; Krasik, Ya. E.

2012-12-15

Time- and space-resolved fast framing photography was employed to study the discharge initiated by runaway electrons in air and He gas at atmospheric pressure. Whereas in the both cases, the discharge occurs in a nanosecond time scale and its front propagates with a similar velocity along the cathode-anode gap, the later stages of the discharge differ significantly. In air, the main discharge channels develop and remain in the locations with the strongest field enhancement. In He gas, the first, diode 'gap bridging' stage, is similar to that obtained in air; however, the development of the discharge that follows is dictatedmore » by an explosive electron emission from micro-protrusions on the edge of the cathode. These results allow us to draw conclusions regarding the different conductivity of the plasma produced in He and air discharges.« less

Estimated intensity of the EMP from lightning discharges necessary for elves initiation based on balloon experiment

NASA Astrophysics Data System (ADS)

Kondo, S.; Yoshida, A.; Takahashi, Y.; Chikada, S.; Adachi, T.; Sakanoi, T.

2007-12-01

Transient optical phenomena in the mesosphere and lower ionosphere called transient luminous events (TLEs) have been investigated extensively since the first discovery in 1989. In the lower ionosphere, elves are generated by the electromagnetic pulses (EMPs) radiated from the intense lightning current. On the ground-based observation, cameras can not always identify the occurrence of elves because elves emission is sometimes reduced significantly by the atmosphere and blocked by clouds. Therefore, it has been difficult to determine the threshold of intensity of EMPs necessary for initiation of elves. We simultaneously carried out optical and sferics measurements for TLEs and lightning discharges using a high altitude balloon launched at Sanriku Balloon Center on the night of August 25 / 26 in 2006. We fixed four CCD cameras on the gondola, each of which had horizontal FOV of ~100 degree. They cover 360 degree in horizontal direction and imaged the TLEs without atmospheric extinction nor blocking by clouds. The frame rate is 30 fps. We installed three dipole antennas at the gondola, which received the vertical and horizontal electric fields radiated from lightning discharges. The frequency range of the VLF receiver is 1-25 kHz. We also make use of VLF sferics data obtained by ground-based antennas located at Tohoku University in Sendai. We picked up six elves from the image data set obtained by the CCD cameras, and examined the maximum amplitudes of the vertical electric field for 22 lightning discharge events including the six elves events observed both at the balloon and at Sendai. It is found that the maximum amplitudes of the vertical electric field in the five elves events are much larger than those in the other lightning events. We estimate the intensity of the radiated electric field necessary for elves. About one elves event, we don't see intense vertical electric field in the balloon data.

Electric discharge synthesis of HCN in simulated Jovian atmospheres

NASA Technical Reports Server (NTRS)

Stribling, Roscoe; Miller, Stanley L.

1987-01-01

Corona discharge is presently considered as a possible source of the HCN detected in the Jovian atmosphere at 2.2 x 10 to the -7th moles/sq cm column density, for the cases of gas mixtures containing H2, CH4, and NH3, with H2/CH4 ratios from 4.4 to 1585. A 3:1 ratio of corona discharge to lightning energy similar to that of the earth is applied to Jupiter. Depending on the lightning energy available on Jupiter and the eddy diffusion coefficients in the synthesis region, HCN column densities generated by corona discharge could account for about 10 percent of the HCN observed.

Electric discharges in air - Near infrared emission spectrum.

NASA Technical Reports Server (NTRS)

Benesch, W. M.; Saum, K. A.

1972-01-01

The emission from glow discharges in flowing air has been investigated in the 1- to 5-micron wavelength region with a vacuum spectrometer. Most of the spectral features observed in the pressure range of .5 to 10 torr are identified, including atomic lines of OI, NI, and HI and molecular bands of N2, NO, N2O, CO2, and CO. The spectra are presented as a function of pressure and a table compiled of the atomic lines. Of particular interest are the contrasts between the emission of the air discharge and that of the pure gases, nitrogen and oxygen. In addition, the results of studies of several discharge modes, employing steady voltages and pulsed, provide data on details of the energy flow within the plasma.

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.

Direct current microhollow cathode discharges on silicon devices operating in argon and helium

NASA Astrophysics Data System (ADS)

Michaud, R.; Felix, V.; Stolz, A.; Aubry, O.; Lefaucheux, P.; Dzikowski, S.; Schulz-von der Gathen, V.; Overzet, L. J.; Dussart, R.

2018-02-01

Microhollow cathode discharges have been produced on silicon platforms using processes usually used for MEMS fabrication. Microreactors consist of 100 or 150 μm-diameter cavities made from Ni and SiO2 film layers deposited on a silicon substrate. They were studied in the direct current operating mode in two different geometries: planar and cavity configuration. Currents in the order of 1 mA could be injected in microdischarges operating in different gases such as argon and helium at a working pressure between 130 and 1000 mbar. When silicon was used as a cathode, the microdischarge operation was very unstable in both geometry configurations. Strong current spikes were produced and the microreactor lifetime was quite short. We evidenced the fast formation of blisters at the silicon surface which are responsible for the production of these high current pulses. EDX analysis showed that these blisters are filled with argon and indicate that an implantation mechanism is at the origin of this surface modification. Reversing the polarity of the microdischarge makes the discharge operate stably without current spikes, but the discharge appearance is quite different from the one obtained in direct polarity with the silicon cathode. By coating the silicon cathode with a 500 nm-thick nickel layer, the microdischarge becomes very stable with a much longer lifetime. No current spikes are observed and the cathode surface remains quite smooth compared to the one obtained without coating. Finally, arrays of 76 and 576 microdischarges were successfully ignited and studied in argon. At a working pressure of 130 mbar, all microdischarges are simultaneously ignited whereas they ignite one by one at higher pressure.

Studies of corona and back discharges in carbon dioxide

NASA Astrophysics Data System (ADS)

Czech, Tadeusz; Sobczyk, Arkadiusz Tomasz; Jaworek, Anatol; Krupa, Andrzej; Rajch, Eryk

2013-01-01

Results of spectroscopic investigations and current-voltage characteristics of corona and back discharges generated in point-plane electrode geometry in CO2 at atmospheric pressure for positive and negative polarity of the discharge electrode are presented in the paper. Three forms of back discharge, for both polarities, were investigated: glow, streamer and low-current back-arc. To generate the back-discharges for the conditions similar to electrostatic precipitator, the plate electrode was covered with fly ash layer. In order to characterize back discharge processes, the emission spectra were measured and compared with those obtained for normal discharge, generated in the same electrode configuration but without the fly ash layer on the plate electrode. The measurements have shown that optical emission spectral lines of atoms and molecules, excited or ionised in back discharge, depend on the forms of the discharge, the discharge current, and are different in the zones close to needle electrode and fly ash layer. From the comparison of spectral lines of back and normal discharges, an effect of fly ash layer on discharge characteristics and morphology has been determined. In normal corona, the emission spectra are mainly predetermined by the working gas components, but in the case of back discharge, the atomic and molecular lines, resulting from chemical composition of fly ash, are also identified. Differences in the spectra of back discharge for positive and negative polarities of the needle electrode have been explained by considering the kind of ions generated in the crater in fly ash layer. For back arc, the emission of spectral lines of atoms and molecules from fly ash layer can be recorded in the crater zone, but in the needle zone, only the emission lines of CO2 and its decomposition products (CO and C2) can be noticed. The studies of back discharge in CO2, as one of the main components of flue gases, were undertaken because this type of discharge, after

Temporal Variations in Distributions of NO and NO2 Densities in Streamer Corona Discharges

NASA Astrophysics Data System (ADS)

Kurakane, Hiroshi; Aramaki, Mitsutoshi; Sasaki, Koichi

2006-10-01

The distributions of NO and NO2 densities were measured in high-pressure streamer corona discharges by laser-induced fluorescence imaging spectroscopy at various delay times after applying pulsed high voltages between needle and planar electrodes. It was found that the decrease in NO2 density in an N2/O2/NO2 discharge was more efficient than that in an N2/NO2 discharge. The dominant removal reaction of NO2 from the N2/O2/NO2 discharge was NO2+O→NO+O2. The importance of this reaction has been confirmed by the simultaneous observation of the distributions of the NO and NO2 densities. The total amount of NO2 removed from the N2/O2/NO2 discharge roughly coincided with the total amount of NO observed at the same delay time.

Confirmed assignments of isomeric dimethylbenzyl radicals generated by corona discharge.

PubMed

Yoon, Young Wook; Lee, Sang Kuk

2011-12-07

The controversial vibronic assignments of isomeric dimethylbenzyl radicals were clearly resolved by using different precursors. By employing corresponding dimethylbenzyl chlorides as precursors, we identified the origins of the vibronic bands of the dimethylbenzyl radicals generated by corona discharge of 1,2,4-trimethylbenzene. From the analysis of the spectra observed from the dimethylbenzyl chlorides in a corona excited supersonic expansion, we revised previous assignments of the 3,4-, 2,4-, and 2,5-dimethylbenzyl radicals. Spectroscopic data of electronic transition and vibrational mode frequencies in the ground electronic state of each isomer were accurately determined by comparing them with those obtained by an ab initio calculation and with the known vibrational data of 1,2,4-trimethylbenzene. © 2011 American Institute of Physics

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)

Systematic investigation of the barrier discharge operation in helium, nitrogen, and mixtures: discharge development, formation and decay of surface charges

NASA Astrophysics Data System (ADS)

Tschiersch, R.; Bogaczyk, M.; Wagner, H.-E.

2014-09-01

As a logical extension to previous investigations of the barrier discharge (BD) in helium and nitrogen, the present work reports on the operation in any mixtures of both pure gases. Using a well-established plane-parallel discharge cell configuration allows to study the influence of the He/N2 mixing ratio on the formation of different discharge modes. Their characterization was made by measuring the discharge emission development together with the formation and decay of surface charges on a bismuth silicon oxide (Bi12SiO20, BSO) crystal. This was realized by the simultaneous application of the spatio-temporally resolved optical emission spectroscopy, and the electro-optic Pockels effect in combination with a CCD high speed camera. The existence diagram for diffuse and filamentary BDs was determined by varying the amplitude and shape of the applied voltage. Over the entire range of the He/N2 ratio, the diffuse mode can be operated at moderate voltage amplitudes whereas filamentation occurs at significant overvoltage and is favoured by a high voltage slew rate. Irrespective of the discharge mode, the overall charge transfer during a discharge breakdown is found to be in excellent agreement with the amount of accumulated surface charges. An exponential decay of the surface charge deposited on the BSO crystal is induced by LED illumination beyond a typical discharge cycle. During the decay process, a broadening of the radial profiles of positive as well as negative surface charge spots originating from previous microdischarges is observed. The investigations contribute to a better understanding of the charge accumulation at a dielectric.

Miniature whirlwinds produced in the laboratory by high-voltage electrical discharges.

PubMed

Ryan, R T; Vonnegut, B

1970-06-12

Laboratory experiments showed that under certain conditions of vorticity the electrical heatinig produced by a high-voltage discharge at atmospheric pressure can cause the formation of a miniature tornado-like vortex. Once it forms, this vortex stabilizes the electrical discharge along its axis and changes its character from that of a spark to high-pressure variety of a glow discharge. Electrical and dynamic parameters were measured. By relating observations and measurements made in these experiments to previous work and to analogous situations in nature, it is concluded that the heating produced by electrical discharges in a large storm may play a significant role in forming and maintaining natural tornadoes.

Influence of repetition frequency on streamer-to-spark breakdown mechanism in transient spark discharge

NASA Astrophysics Data System (ADS)

Janda, M.; Martišovitš, V.; Buček, A.; Hensel, K.; Molnár, M.; Machala, Z.

2017-10-01

Streamer-to-spark transition in a self-pulsing positive transient spark (TS) discharge was investigated at different repetition frequencies. The temporal evolution of the TS was recorded, showing the primary streamer and the secondary streamer phases. A streak camera-like images were obtained using spatio-temporal reconstruction of the discharge emission detected by a photomultiplier tube with light collection system placed on a micrometric translation stage. With increasing TS repetition frequency f (from ~1 to 6 kHz), the increase of the propagation velocity of both the primary and the secondary streamer was observed. Acceleration of the primary and secondary streamers, and shortening of streamer-to-spark transition time τ with increasing f was attributed to the memory effect composed of pre-heating and gas composition changes induced by the previous TS pulses. Fast propagation of the secondary streamer through the entire gap and fast gas heating could explain the short τ (~100 ns) at f above ~3 kHz.

Plasma-Chemical Synthesis of Oxide Powders Using Transformer-Coupled Discharge

NASA Astrophysics Data System (ADS)

M. Ulanov, I.; V. Isupov, M.; Yu Litvinsev, A.; A. Mischenko, P.

2013-04-01

An experimental investigation of transformer-coupled discharge in an Ar-O2 mixture with the addition of SiCl4, TiCl4 and ZrCl4 has been carried out under the atmospheric pressure of plasma-forming gases. Discharge power and discharge heat losses have been determined, and the dispersion and phase composition of reaction products (oxide powders) has been analyzed with SEM and X-ray diffraction analysis. Investigations reveal the formation of ultrafine oxide powders in the case of vaporized chloride (SiCl4 and TiCl4) injecting into the transformer coupled discharge. In the case of fine powder (ZrCl4) injection, full oxidation was not observed and reaction products consisted of a mixture of ZrO2 and ZrOCl2. A conclusion has been made regarding the perspectives of using transformer-coupled discharge to produce ultrafine oxide powders.

Nonmonotonic radial distribution of excited atoms in a positive column of pulsed direct currect discharges in helium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnat, E. V.; Kolobov, V. I.

2013-01-21

Nonmonotonic radial distributions of excited helium atoms have been experimentally observed in a positive column of pulsed helium discharges using planar laser induced fluorescence. Computational analysis of the discharge dynamics with a fluid plasma model confirms the experimental observations over a range of pressures and currents. The observed effect is attributed to the peculiarities of electron population-depopulation of the excited states during the 'dynamic discharge' conditions with strong modulations of the electric field maintaining the plasma.

Polymerization of phenol by using discharged plasma under hydrothermal state

NASA Astrophysics Data System (ADS)

Mitsugi, M.; Yoshida, A.; Watanabe, H.; Kiyan, T.; Takade, M.; Miyaji, K.; Namihira, T.; Kuwahara, Y.; Akiyama, H.; Hara, M.; Sasaki, M.; Goto, M.

2010-03-01

Supercritical fluid with plasma is a type of green processing media because this technique does not use catalyst and toxic solvents. In this study, we carried out experiments of organic materials in the presence of discharged plasma in sub- and supercritical water to evaluate the possibility for new reactions. For this purpose, we used SUS316 reactor that generates plasma at temperature and pressure up to 573K and 30MPa, respectively. 100 mmol/L aqueous phenol solution was used as starting material. The reactions were carried out at temperature of 523K and under pressure of 25MPa. After a series of reactions, water-soluble, water-insoluble (oily products), solid residue and gaseous product were obtained. For the analysis of these products, HPLC, GC-MS, TOC, GC-TCD and TOF-MS were used. The highest phenol conversion was 16.96% obtained at 523K, 25MPa and with 4000 times discharged plasma. Polymerized phenol was obtained as a product.

Multi-criteria Evaluation of Discharge Simulation in Dynamic Global Vegetation Models

NASA Astrophysics Data System (ADS)

Yang, H.; Piao, S.; Zeng, Z.; Ciais, P.; Yin, Y.; Friedlingstein, P.; Sitch, S.; Ahlström, A.; Guimberteau, M.; Huntingford, C.; Levis, S.; Levy, P. E.; Huang, M.; Li, Y.; Li, X.; Lomas, M.; Peylin, P. P.; Poulter, B.; Viovy, N.; Zaehle, S.; Zeng, N.; Zhao, F.; Wang, L.

2015-12-01

In this study, we assessed the performance of discharge simulations by coupling the runoff from seven Dynamic Global Vegetation Models (DGVMs; LPJ, ORCHIDEE, Sheffield-DGVM, TRIFFID, LPJ-GUESS, CLM4CN, and OCN) to one river routing model for 16 large river basins. The results show that the seasonal cycle of river discharge is generally modelled well in the low and mid latitudes, but not in the high latitudes, where the peak discharge (due to snow and ice melting) is underestimated. For the annual mean discharge, the DGVMs chained with the routing model show an underestimation. Furthermore the 30-year trend of discharge is also under-estimated. For the inter-annual variability of discharge, a skill score based on overlapping of probability density functions (PDFs) suggests that most models correctly reproduce the observed variability (correlation coefficient higher than 0.5; i.e. models account for 50% of observed inter-annual variability) except for the Lena, Yenisei, Yukon, and the Congo river basins. In addition, we compared the simulated runoff from different simulations where models were forced with either fixed or varying land use. This suggests that both seasonal and annual mean runoff has been little affected by land use change, but that the trend itself of runoff is sensitive to land use change. None of the models when considered individually show significantly better performances than any other and in all basins. This suggests that based on current modelling capability, a regional-weighted average of multi-model ensemble projections might be appropriate to reduce the bias in future projection of global river discharge.

Observation of Electron-Beam-Induced Phase Evolution Mimicking the Effect of the Charge–Discharge Cycle in Li-Rich Layered Cathode Materials Used for Li Ion Batteries

DOE PAGES

Lu, Ping; Yan, Pengfei; Romero, Eric; ...

2015-01-27

Capacity loss, and voltage decrease upon electrochemical charge-discharge cycling observed in lithium-rich layered cathode oxides (Li[Li xMn yTM 1-x-y]O 2, TM = Ni, Co or Fe) have recently been attributed to the formation of a surface reconstructed layer (SRL) that evolves from a thin (<2 nm), defect spinel layer upon the first charge, to a relatively thick (~5nm), spinel or rock-salt layer upon continuous charge-discharge cycling. Here we report observations of a SRL and structural evolution of the SRL on the Li[Li 0.2Ni 0.2Mn 0.6]O 2 (LNMO) particles, which are identical to those reported due to the charge-discharge cycle butmore » are a result of electron-beam irradiation during scanning transmission electron microscopy (STEM) imaging. Sensitivity of the lithium-rich layered oxides to high-energy electrons leads to the formation of thin, defect spinel layer on surfaces of the particles when exposed to a 200kV electron beam for as little as 30 seconds under normal high-resolution STEM imaging conditions. Further electron irradiation produces a thicker layer of the spinel phase, ultimately producing a rock-salt layer at a higher electron exposure. Atomic-scale chemical mapping by electron dispersive X-ray spectroscopy in STEM indicates the electron-beam-induced SRL formation on LNMO is accomplished by migration of the transition metal ions to the Li sites without breaking down the lattice. The observation through this study provides an insight for understanding the mechanism of forming the SRL and also possibly a mean to study structural evolution in the Li-rich layered oxides without involving the electrochemistry.« less

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.

Post-processing of multi-model ensemble river discharge forecasts using censored EMOS

NASA Astrophysics Data System (ADS)

Hemri, Stephan; Lisniak, Dmytro; Klein, Bastian

2014-05-01

When forecasting water levels and river discharge, ensemble weather forecasts are used as meteorological input to hydrologic process models. As hydrologic models are imperfect and the input ensembles tend to be biased and underdispersed, the output ensemble forecasts for river runoff typically are biased and underdispersed, too. Thus, statistical post-processing is required in order to achieve calibrated and sharp predictions. Standard post-processing methods such as Ensemble Model Output Statistics (EMOS) that have their origins in meteorological forecasting are now increasingly being used in hydrologic applications. Here we consider two sub-catchments of River Rhine, for which the forecasting system of the Federal Institute of Hydrology (BfG) uses runoff data that are censored below predefined thresholds. To address this methodological challenge, we develop a censored EMOS method that is tailored to such data. The censored EMOS forecast distribution can be understood as a mixture of a point mass at the censoring threshold and a continuous part based on a truncated normal distribution. Parameter estimates of the censored EMOS model are obtained by minimizing the Continuous Ranked Probability Score (CRPS) over the training dataset. Model fitting on Box-Cox transformed data allows us to take account of the positive skewness of river discharge distributions. In order to achieve realistic forecast scenarios over an entire range of lead-times, there is a need for multivariate extensions. To this end, we smooth the marginal parameter estimates over lead-times. In order to obtain realistic scenarios of discharge evolution over time, the marginal distributions have to be linked with each other. To this end, the multivariate dependence structure can either be adopted from the raw ensemble like in Ensemble Copula Coupling (ECC), or be estimated from observations in a training period. The censored EMOS model has been applied to multi-model ensemble forecasts issued on a

Costs and outcomes associated with alternative discharge strategies following joint replacement surgery: analysis of an observational study using a propensity score.

PubMed

Coyte, P C; Young, W; Croxford, R

2000-11-01

We estimated the impact of alternative discharge strategies, following joint replacement (JR) surgery, on acute care readmission rates and the total cost of a continuum of care. Following surgery, patients were discharged to one of four destinations. Propensity scores were used to adjust costs and outcomes for potential bias in the assignment of discharge destinations. We demonstrated that the use of rehabilitation hospitals may lower readmission rates, but at a prohibitive incremental cost of each saved readmission, that patients discharged with home care had longer acute care stays than other patients, that the provision of home care services increased health system costs, and that acute care readmission rates were greatest among patients discharged with home care. Our study should be seen as one important stepping stone towards a full economic evaluation of the continuum of care for patients.

Potential relationships between the river discharge and the precipitation in the Jinsha River basin, China

NASA Astrophysics Data System (ADS)

Wang, Gaoxu; Zeng, Xiaofan; Zhao, Na; He, Qifang; Bai, Yiran; Zhang, Ruoyu

2018-02-01

The relationships between the river discharge and the precipitation in the Jinsha River basin are discussed in this study. In addition, the future precipitation trend from 2011-2050 and its potential influence on the river discharge are analysed by applying the CCLM-modelled precipitation. According to the observed river discharge and precipitation, the annual river discharge at the two main hydrological stations displays good correlations with the annual precipitation in the Jinsha River basin. The predicted future precipitation tends to change similarly as the change that occurred during the observation period, whereas the monthly distributions over a year could be more uneven, which is unfavourable for water resources management.

Chemistry of groundwater discharge inferred from longitudinal river sampling

NASA Astrophysics Data System (ADS)

Batlle-Aguilar, J.; Harrington, G. A.; Leblanc, M.; Welch, C.; Cook, P. G.

2014-02-01

We present an approach for identifying groundwater discharge chemistry and quantifying spatially distributed groundwater discharge into rivers based on longitudinal synoptic sampling and flow gauging of a river. The method is demonstrated using a 450 km reach of a tropical river in Australia. Results obtained from sampling for environmental tracers, major ions, and selected trace element chemistry were used to calibrate a steady state one-dimensional advective transport model of tracer distribution along the river. The model closely reproduced river discharge and environmental tracer and chemistry composition along the study length. It provided a detailed longitudinal profile of groundwater inflow chemistry and discharge rates, revealing that regional fractured mudstones in the central part of the catchment contributed up to 40% of all groundwater discharge. Detailed analysis of model calibration errors and modeled/measured groundwater ion ratios elucidated that groundwater discharging in the top of the catchment is a mixture of local groundwater and bank storage return flow, making the method potentially useful to differentiate between local and regional sourced groundwater discharge. As the error in tracer concentration induced by a flow event applies equally to any conservative tracer, we show that major ion ratios can still be resolved with minimal error when river samples are collected during transient flow conditions. The ability of the method to infer groundwater inflow chemistry from longitudinal river sampling is particularly attractive in remote areas where access to groundwater is limited or not possible, and for identification of actual fluxes of salts and/or specific contaminant sources.

Observation of twinning in diamond CVD films

NASA Astrophysics Data System (ADS)

Marciniak, W.; Fabisiak, K.; Orzeszko, S.; Rozploch, F.

1992-10-01

Diamond particles prepared by dc-glow-discharge enhanced HF-CVD hybrid method, from a mixture of acetone vapor and hydrogen gas have been examined by TEM, RHEED and dark field method of observation. Results suggest the presence of twinned diamond particles, which can be reconstructed by a sequence of twinning operations. Contrary to the 'stick model' of the lattice, very common five-fold symmetry of diamond microcrystals may be obtained by applying a number of edge dislocations rather than the continuous deformation of many tetrahedral C-C bonds.

Theoretical Study of Methods for Improving the Energy Efficiency of NOx Removal from Diesel Exhaust Gases by Silent Discharge

NASA Astrophysics Data System (ADS)

Shoyama, Taiji; Yoshioka, Yoshio

To improve the NO removal performance in silent discharge process, we investigated the influence of the physical parameters such as current density, channel radius and pulse duration of the one micro discharge under the constant reduced electric field strength. And influence of the micro discharges occurrence locations were also discussed. In order to analyze the NO removal process, we assumed that the pulse micro discharges occur repeatedly at the same location in static gas and that the chemical reactions induced by micro discharge forms many radicals, which react with pollutants and by-products. The conclusions we obtained are that lower current density, smaller discharge radius and shorter discharge duration improve NO removal efficiency. These results also mean that the lower discharge energy of the one micro discharge and the larger number of parallel micro discharges increase the NO removal performance. Therefore, to make the area of one micro discharge small is a desirable way to improve the NO removal performance. So we think that the glow like discharge might be more effective than the streamer like discharge mode. Next, using the two-dimensional model, which considered the influence of gas flow, we obtained a conclusion that the repeated micro discharges at different positions are very effective to increase the De-NOx performance. The reason is that the reaction of NO2+O→NO+O2 and ozone dissociation reactions are suppressed by the movement of the location of micro discharges.

Study of the catastrophic discharge phenomenon in a Hall thruster

NASA Astrophysics Data System (ADS)

Ding, Yongjie; Su, Hongbo; Li, Peng; Wei, Liqiu; Li, Hong; Peng, Wuji; Xu, Yu; Sun, Hezhi; Yu, Daren

2017-10-01

In a 1350-W Hall-effect thruster, in which a technique for pushing down the magnetic field is implemented, a catastrophic discharge phenomenon is identified by varying the magnetic field strength while keeping all other operating parameters constant. According to experiments, before and after the discharge catastrophe, the plume changes from focusing state to a divergent state, and discharge parameters such as discharge current and thrust exhibit noticeable changes. The divergence half-angle of the plume increases from 22° to 46°. The oscillation amplitude and mean values of the discharge current significantly increase from 0.8 A to 4 A and from 4.6 A to 6.3 A, respectively, while the thrust increases from 89.3 mN to 91 mN. Analysis of the experimental results shows that as the maximum magnetic field of the thruster we developed is in the plume region, the acceleration occurs in the plume region and a large number of Xe2+ ions appear in the plume area, the catastrophic discharge phenomenon observed.

Problems associated with estimating ground water discharge and recharge from stream-discharge records

USGS Publications Warehouse

Halford, K.J.; Mayer, G.C.

2000-01-01

Ground water discharge and recharge frequently have been estimated with hydrograph-separation techniques, but the critical assumptions of the techniques have not been investigated. The critical assumptions are that the hydraulic characteristics of the contributing aquifer (recession index) can be estimated from stream-discharge records; that periods of exclusively ground water discharge can be reliably identified; and that stream-discharge peaks approximate the magnitude and tinting of recharge events. The first assumption was tested by estimating the recession index from st earn-discharge hydrographs, ground water hydrographs, and hydraulic diffusivity estimates from aquifer tests in basins throughout the eastern United States and Montana. The recession index frequently could not be estimated reliably from stream-discharge records alone because many of the estimates of the recession index were greater than 1000 days. The ratio of stream discharge during baseflow periods was two to 36 times greater than the maximum expected range of ground water discharge at 12 of the 13 field sites. The identification of the ground water component of stream-discharge records was ambiguous because drainage from bank-storage, wetlands, surface water bodies, soils, and snowpacks frequently exceeded ground water discharge and also decreased exponentially during recession periods. The timing and magnitude of recharge events could not be ascertained from stream-discharge records at any of the sites investigated because recharge events were not directly correlated with stream peaks. When used alone, the recession-curve-displacement method and other hydrograph-separation techniques are poor tools for estimating ground water discharge or recharge because the major assumptions of the methods are commonly and grossly violated. Multiple, alternative methods of estimating ground water discharge and recharge should be used because of the uncertainty associated with any one technique.

Protracted immune disorders at one year after ICU discharge in patients with septic shock.

PubMed

Riché, Florence; Chousterman, Benjamin G; Valleur, Patrice; Mebazaa, Alexandre; Launay, Jean-Marie; Gayat, Etienne

2018-02-21

Sepsis is a leading cause of mortality and critical illness worldwide and is associated with an increased mortality rate in the months following hospital discharge. The occurrence of persistent or new organ dysfunction(s) after septic shock raises questions about the mechanisms involved in the post-sepsis status. The present study aimed to explore the immune profiles of patients one year after being discharged from the intensive care unit (ICU) following treatment for abdominal septic shock. We conducted a prospective, single-center, observational study in the surgical ICU of a university hospital. Eighty-six consecutive patients admitted for septic shock of abdominal origin were included in this study. Fifteen different plasma biomarkers were measured at ICU admission, at ICU discharge and at one year after ICU discharge. Three different clusters of biomarkers were distinguished according to their functions, namely: (1) inflammatory response, (2) cell damage and apoptosis, (3) immunosuppression and resolution of inflammation. The primary objective was to characterize variations in the immune status of septic shock patients admitted to ICU up to one year after ICU discharge. The secondary objective was to evaluate the relationship between these biomarker variations and patient outcomes. At the onset of septic shock, we observed a cohesive pro-inflammatory profile and low levels of inflammation resolution markers. At ICU discharge, the immune status demonstrated decreased but persistent inflammation and increased immunosuppression, with elevated programmed cell death protein-1 (PD-1) levels, and a counterbalanced resolution process, with elevated levels of interleukin-10 (IL-10), resolvin D5 (RvD5), and IL-7. One year after hospital discharge, homeostasis was not completely restored with several markers of inflammation remaining elevated. Remarkably, IL-7 was persistently elevated, with levels comparable to those observed after ICU discharge, and PD-1, while lower

Review of Oceanographic and Geochemical Data Collected in Massachusetts Bay during a Large Discharge of Total Suspended Solids from Boston's Sewage-Treatment System and Ocean Outfall in August 2002

USGS Publications Warehouse

Bothner, Michael H.; Butman, Bradford; Casso, Michael A.

2010-01-01

During the period August 14-23, 2002, the discharge of total suspended solids (TSS) from the Massachusetts Water Resources Authority sewage-treatment plant ranged from 32 to 132 milligrams per liter, causing the monthly average discharge to exceed the limit specified in the National Pollution Discharge Elimination System permit. Time-series monitoring data collected by the U.S. Geological Survey in western Massachusetts Bay were examined to evaluate changes in environmental conditions during and after this exceedance event. The rate of sediment trapping and the concentrations of near-bottom suspended sediment measured near the outfall in western Massachusetts Bay increased during this period. Because similar increases in sediment-trapping rate were observed in the summers of 2003 and 2004, however, the increase in 2002 cannot be definitively attributed to the increased TSS discharge. Concentrations of copper and silver in trapped sediment collected 10 and 20 days following the 2002 TSS event were elevated compared to those in pre-event samples. Maximum concentrations were less than 50 percent of toxicity guidelines. Photographs of surficial bottom sediments obtained before and after the TSS event do not show sediment accumulation on the sea floor. Concentrations of silver, Clostridium perfringens, and clay in surficial bottom sediments sampled 10 weeks after the discharge event at a depositional site 3 kilometers west of the outfall were unchanged from those in samples obtained before the event. Simulation of the TSS event by using a coupled hydrodynamic-wave-sediment-transport model could enhance understanding of these observations and of the effects of the exceedance on the local marine environment.

Application of Microsecond Voltage Pulses for Water Disinfection by Diaphragm Electric Discharge

NASA Astrophysics Data System (ADS)

Kakaurov, S. V.; Suvorov, I. F.; Yudin, A. S.; Solovyova, T. L.; Kuznetsova, N. S.

2015-11-01

The paper presents the dependence of copper and silver ions formation on the duration of voltage pulses of diaphragm electric discharge and on the pH of treated liquid medium. Knowing it allows one to create an automatic control system to control bactericidal agent's parameters obtained in diaphragm electric discharge reactor. The current-voltage characteristic of the reactor with a horizontal to the diaphragm membrane water flow powered from the author's custom pulse voltage source is also presented. The results of studies of the power consumption of diaphragm electric discharge depending on temperature of the treated liquid medium are given.

Generation of whistler-wave heated discharges with planar resonant RF networks.

PubMed

Guittienne, Ph; Howling, A A; Hollenstein, Ch

2013-09-20

Magnetized plasma discharges generated by a planar resonant rf network are investigated. A regime transition is observed above a magnetic field threshold, associated with rf waves propagating in the plasma and which present the characteristics of whistler waves. These wave heated regimes can be considered as analogous to conventional helicon discharges, but in planar geometry.

An evaluation of water-quality data obtained at four streamflow daily-record stations in Idaho

USGS Publications Warehouse

Dyer, Kenneth L.

1973-01-01

Chemical data for four stream-gaging stations in Idaho, each having 6 to 22 years of available records, were analyzed to determine functional relations between concentrations of the major inorganic constituents, specific conductance, and stream discharge. Three of the four stations had sufficient available record for assessing changes in constituent relations with time. The records for each long-term station were subdivided into segments of approximately 5 years each. Plots and regression equations were derived for each record segment to show the relations of each major constituent value to levels of specific conductance and stream discharge. At only one stations, Boise River at Notus, was there was an apparent significant change in chemical characteristics with time. Between 1940 and 1951, the percentages of chloride and sulfate in solution at this station declined appreciably and were largely replaced by bicarbonate. In general, there were highly significant correlations between the major inorganic ions and specific conductance, although those observed at Bear River at Border were distinctly poorer than those observed for the other stations. Corresponding correlations between the major ions and discharge were almost always less significant than those observed between the same ions and specific conductance. The common ion-discharge relations observed on the Snake River near Heise were more highly correlated before 1957 than thereafter--probably because of changes induced by the construction of Palisades Dam. A similar decline in correlation of common ion-discharge relations was observed at the Snake River at King Hill station after 1957, and this also might be attributable to changes in water regulation at various upstream impoundments.

Comparison of the observed and calculated coherent forward scattering spectra of the 842.5 nm Ar I and 844.6 nm O I lines in a radio frequency glow discharge

NASA Astrophysics Data System (ADS)

Matsuta, Hideyuki

2017-06-01

The coherent forward scattering (CFS) spectra of O I 844.6 nm and Ar I 842.5 nm lines in a radio frequency (RF) glow discharge were measured using a CFS spectrometer that functions in the Faraday configuration with permanent double-ring magnets and a diode-laser source. A significant change in the CFS spectrum of the Ar I 842.5 nm line was observed when the partial pressures of argon in a Hesbnd Ar RF glow discharge were changed . Based on the theoretical calculations of the CFS spectra performed using Faraday functions, a comparison between the observed and calculated spectra was performed. The CFS line profile of O I 844.6 nm and changes in the Ar I 842.5 nm CFS spectrum are explained by theoretical calculations.

Power-law scaling in daily rainfall patterns and consequences in urban stream discharges

NASA Astrophysics Data System (ADS)

Park, Jeryang; Krueger, Elisabeth H.; Kim, Dongkyun; Rao, Suresh C.

2016-04-01

Poissonian rainfall has been frequently used for modelling stream discharge in a catchment at the daily scale. Generally, it is assumed that the daily rainfall depth is described by memoryless exponential distribution which is transformed to stream discharge, resulting in an analytical pdf for discharge [Gamma distribution]. While it is true that catchment hydrological filtering processes (censored by constant rate ET losses, and first-order recession) increases "memory", reflected in 1/f noise in discharge time series. Here, we show that for urban watersheds in South Korea: (1) the observation of daily rainfall depths follow power-law pdfs, and spectral slopes range between 0.2 ~ 0.4; and (2) the stream discharge pdfs have power-law tails. These observation results suggest that multiple hydro-climatic factors (e.g., non-stationarity of rainfall patterns) and hydrologic filtering (increasing impervious area; more complex urban drainage networks) influence the catchment hydrologic responses. We test the role of such factors using a parsimonious model, using different types of daily rainfall patterns (e.g., power-law distributed rainfall depth with Poisson distribution in its frequency) and urban settings to reproduce patterns similar to those observed in empirical records. Our results indicate that fractality in temporally up-scaled rainfall, and the consequences of large extreme events are preserved as high discharge events in urbanizing catchments. Implications of these results to modeling urban hydrologic responses and impacts on receiving waters are discussed.

High-altitude electrical discharges associated with thunderstorms and lightning

NASA Astrophysics Data System (ADS)

Liu, Ningyu; McHarg, Matthew G.; Stenbaek-Nielsen, Hans C.

2015-12-01

The purpose of this paper is to introduce electrical discharge phenomena known as transient luminous events above thunderstorms to the lightning protection community. Transient luminous events include the upward electrical discharges from thunderstorms known as starters, jets, and gigantic jets, and electrical discharges initiated in the lower ionosphere such as sprites, halos, and elves. We give an overview of these phenomena with a focus on starters, jets, gigantic jets, and sprites, because similar to ordinary lightning, streamers and leaders are basic components of these four types of transient luminous events. We present a few recent observations to illustrate their main properties and briefly review the theories. The research in transient luminous events has not only advanced our understanding of the effects of thunderstorms and lightning in the middle and upper atmosphere, but also improved our knowledge of basic electrical discharge processes critical for sparks and lightning.

Estimating discharge measurement uncertainty using the interpolated variance estimator

USGS Publications Warehouse

Cohn, T.; Kiang, J.; Mason, R.

2012-01-01

Methods for quantifying the uncertainty in discharge measurements typically identify various sources of uncertainty and then estimate the uncertainty from each of these sources by applying the results of empirical or laboratory studies. If actual measurement conditions are not consistent with those encountered in the empirical or laboratory studies, these methods may give poor estimates of discharge uncertainty. This paper presents an alternative method for estimating discharge measurement uncertainty that uses statistical techniques and at-site observations. This Interpolated Variance Estimator (IVE) estimates uncertainty based on the data collected during the streamflow measurement and therefore reflects the conditions encountered at the site. The IVE has the additional advantage of capturing all sources of random uncertainty in the velocity and depth measurements. It can be applied to velocity-area discharge measurements that use a velocity meter to measure point velocities at multiple vertical sections in a channel cross section.

Using the red/yellow/green discharge tool to improve the timeliness of hospital discharges.

PubMed

Mathews, Kusum S; Corso, Philip; Bacon, Sandra; Jenq, Grace Y

2014-06-01

As part of Yale-New Haven Hospital (Connecticut)'s Safe Patient Flow Initiative, the physician leadership developed the Red/Yellow/Green (RYG) Discharge Tool, an electronic medical record-based prompt to identify likelihood of patients' next-day discharge: green (very likely), yellow (possibly), and red (unlikely). The tool's purpose was to enhance communication with nursing/care coordination and trigger earlier discharge steps for patients identified as "green" or "yellow." Data on discharge assignments, discharge dates/ times, and team designation were collected for all adult medicine patients discharged in October-December 2009 (Study Period 1) and October-December 2011 (Study Period 2), between which the tool's placement changed from the sign-out note to the daily progress note. In Study Period 1, 75.9% of the patients had discharge assignments, compared with 90.8% in Period 2 (p < .001). The overall 11 A.M. discharge rate improved from 10.4% to 21.2% from 2007 to 2011. "Green" patients were more likely to be discharged before 11 A.M. than "yellow" or "red" patients (p < .001). Patients with RYG assignments discharged by 11 A.M. had a lower length of stay than those without assignments and did not have an associated increased risk of readmission. Discharge prediction accuracy worsened after the change in placement, decreasing from 75.1% to 59.1% for "green" patients (p < .001), and from 34.5% to 29.2% (p < .001) for "yellow" patients. In both periods, hospitalists were more accurate than house staff in discharge predictions, suggesting that education and/or experience may contribute to discharge assignment. The RYG Discharge Tool helped facilitate earlier discharges, but accuracy depends on placement in daily work flow and experience.

Using the Red/Yellow/Green Discharge Tool to Improve the Timeliness of Hospital Discharges

PubMed Central

Mathews, Kusum S.; Corso, Philip; Bacon, Sandra; Jenq, Grace Y.

2015-01-01

Background As part of Yale-New Haven Hospital (Connecticut)’s Safe Patient Flow Initiative, the physician leadership developed the Red/Yellow/Green (RYG) Discharge Tool, an electronic medical record–based prompt to identify likelihood of patients’ next-day discharge: green (very likely), yellow (possibly), and red (unlikely). The tool’s purpose was to enhance communication with nursing/care coordination and trigger earlier discharge steps for patients identified as “green” or “yellow”. Methods Data on discharge assignments, discharge dates/times, and team designation were collected for all adult medicine patients discharged from October – December 2009 (Study Period 1) and October – December 2011 (Study Period 2), between which the tool’s placement changed from the sign-out note to the daily progress note. Results In Study Period 1, 75.9% of the patients had discharge assignments, compared with 90.8% in Period 2 (p < .001). The overall 11 A.M. discharge rate improved from 10.4% to 21.2% from 2007 to 2011. “Green” patients were more likely to be discharged before 11 A.M. than “yellow” or “red” patients (p < .001). Patients with RYG assignments discharged by 11 A.M. had a lower length of stay than those without assignments and did not have an associated increased risk of readmission. Discharge prediction accuracy worsened after the change in placement, decreasing from 75.1% to 59.1% for “green” patients (p < .001), and from 34.5% to 29.2% (p < .001) for “yellow” patients. In both periods, hospitalists were more accurate than housestaff in discharge predictions, suggesting that education and/or experience may contribute to discharge assignment. Conclusions The RYG Discharge Tool helped facilitate earlier discharges, but accuracy depends on placement in daily work flow and experience. PMID:25016672

Exploring SWOT discharge algorithm accuracy on the Sacramento River

NASA Astrophysics Data System (ADS)

Durand, M. T.; Yoon, Y.; Rodriguez, E.; Minear, J. T.; Andreadis, K.; Pavelsky, T. M.; Alsdorf, D. E.; Smith, L. C.; Bales, J. D.

2012-12-01

Scheduled for launch in 2019, the Surface Water and Ocean Topography (SWOT) satellite mission will utilize a Ka-band radar interferometer to measure river heights, widths, and slopes, globally, as well as characterize storage change in lakes and ocean surface dynamics with a spatial resolution ranging from 10 - 70 m, with temporal revisits on the order of a week. A discharge algorithm has been formulated to solve the inverse problem of characterizing river bathymetry and the roughness coefficient from SWOT observations. The algorithm uses a Bayesian Markov Chain estimation approach, treats rivers as sets of interconnected reaches (typically 5 km - 10 km in length), and produces best estimates of river bathymetry, roughness coefficient, and discharge, given SWOT observables. AirSWOT (the airborne version of SWOT) consists of a radar interferometer similar to SWOT, but mounted aboard an aircraft. AirSWOT spatial resolution will range from 1 - 35 m. In early 2013, AirSWOT will perform several flights over the Sacramento River, capturing river height, width, and slope at several different flow conditions. The Sacramento River presents an excellent target given that the river includes some stretches heavily affected by management (diversions, bypasses, etc.). AirSWOT measurements will be used to validate SWOT observation performance, but are also a unique opportunity for testing and demonstrating the capabilities and limitations of the discharge algorithm. This study uses HEC-RAS simulations of the Sacramento River to first, characterize expected discharge algorithm accuracy on the Sacramento River, and second to explore the required AirSWOT measurements needed to perform a successful inverse with the discharge algorithm. We focus on several specific research questions affecting algorithm performance: 1) To what extent do lateral inflows confound algorithm performance? We examine the ~100 km stretch of river from Colusa, CA to the Yolo Bypass, and investigate how the

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 - ...

An automated system to simulate the River discharge in Kyushu Island using the H08 model

NASA Astrophysics Data System (ADS)

Maji, A.; Jeon, J.; Seto, S.

2015-12-01

Kyushu Island is located in southwestern part of Japan, and it is often affected by typhoons and a Baiu front. There have been severe water-related disasters recorded in Kyushu Island. On the other hand, because of high population density and for crop growth, water resource is an important issue of Kyushu Island.The simulation of river discharge is important for water resource management and early warning of water-related disasters. This study attempts to apply H08 model to simulate river discharge in Kyushu Island. Geospatial meteorological and topographical data were obtained from Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT) and Automated Meteorological Data Acquisition System (AMeDAS) of Japan Meteorological Agency (JMA). The number of the observation stations of AMeDAS is limited and is not quite satisfactory for the application of water resources models in Kyushu. It is necessary to spatially interpolate the point data to produce grid dataset. Meteorological grid dataset is produced by considering elevation dependence. Solar radiation is estimated from hourly sunshine duration by a conventional formula. We successfully improved the accuracy of interpolated data just by considering elevation dependence and found out that the bias is related to geographical location. The rain/snow classification is done by H08 model and is validated by comparing estimated and observed snow rate. The estimates tend to be larger than the corresponding observed values. A system to automatically produce daily meteorological grid dataset is being constructed.The geospatial river network data were produced by ArcGIS and they were utilized in the H08 model to simulate the river discharge. Firstly, this research is to compare simulated and measured specific discharge, which is the ratio of discharge to watershed area. Significant error between simulated and measured data were seen in some rivers. Secondly, the outputs by the coupled model including crop growth

Modeling the probability distribution of peak discharge for infiltrating hillslopes

NASA Astrophysics Data System (ADS)

Baiamonte, Giorgio; Singh, Vijay P.

2017-07-01

Hillslope response plays a fundamental role in the prediction of peak discharge at the basin outlet. The peak discharge for the critical duration of rainfall and its probability distribution are needed for designing urban infrastructure facilities. This study derives the probability distribution, denoted as GABS model, by coupling three models: (1) the Green-Ampt model for computing infiltration, (2) the kinematic wave model for computing discharge hydrograph from the hillslope, and (3) the intensity-duration-frequency (IDF) model for computing design rainfall intensity. The Hortonian mechanism for runoff generation is employed for computing the surface runoff hydrograph. Since the antecedent soil moisture condition (ASMC) significantly affects the rate of infiltration, its effect on the probability distribution of peak discharge is investigated. Application to a watershed in Sicily, Italy, shows that with the increase of probability, the expected effect of ASMC to increase the maximum discharge diminishes. Only for low values of probability, the critical duration of rainfall is influenced by ASMC, whereas its effect on the peak discharge seems to be less for any probability. For a set of parameters, the derived probability distribution of peak discharge seems to be fitted by the gamma distribution well. Finally, an application to a small watershed, with the aim to test the possibility to arrange in advance the rational runoff coefficient tables to be used for the rational method, and a comparison between peak discharges obtained by the GABS model with those measured in an experimental flume for a loamy-sand soil were carried out.

Discharge dynamics of pin-to-plate dielectric barrier discharge at atmospheric pressure

NASA Astrophysics Data System (ADS)

Sun, Liqun; Huang, Xiaojiang; Zhang, Jie; Zhang, Jing; Shi, J. J.

2010-11-01

The discharge dynamics of pin-to-plate dielectric barrier discharge was studied in atmospheric helium at 20 kHz. The discharge was predominately ignited in positive half cycle of applied voltage with sinusoidal waveform. The temporal evolution of the discharge was investigated vertically along the discharge gap and radically on the dielectric surface by time resolved imaging. It is found that a discharge column with a diameter of 2 mm was ignited above the pin electrode and expanded toward a plate electrode. On the dielectric surface with space charge accumulation, plasma disk in terms of plasma ring was formed with radius up to 25 mm. The expansion velocity of plasma ring can reach a hypersonic speed of 3.0 km/s. The ionization wave due to electron diffusion is considered to be the mechanism for plasma ring formation and dynamics.

Area scaling investigations of charging phenomena. [discharge pulse characteristics of Teflon thermal control tape

NASA Technical Reports Server (NTRS)

Aron, P. R.; Staskus, J. V.

1979-01-01

The charging and discharging behavior of square, planar samples of silvered, fluorinated ethylene-propylene (FEP) Teflon thermal control tape was measured. The equilibrium voltage profiles scaled with the width of the sample. A wide range of discharge pulse characteristics was observed, and the area dependences of the peak current, charge, and pulse widths are described. The observed scaling of the peak currents with area was weaker than that previously reported. The discharge parameters were observed to depend strongly on the grounding impedance and the beam voltage. Preliminary results suggest that measuring only the return-current-pulse characteristics is not adequate to describe the spacecraft discharging behavior of this material. The seams between strips of tape appear to play a fundamental role in determining the discharging behavior. An approximate propagation velocity for the charge cleanoff was extracted from the data. The samples - 232, 1265, and 5058 square centimeters in area - were exposed at ambient temperature to a 1- to 2-nA/sq cm electron beam at energies of 10, 15, and 20 kilovolts in a 19-meter-long by 4.6-meter-diameter simulation facility at the Lewis Research Center.

Hydrogen and Ethene Plasma Assisted Ignition by NS discharge at Elevated Temperatures

NASA Astrophysics Data System (ADS)

Starikovskiy, Andrey

2015-09-01

The kinetics of ignition in lean H2:O2:Ar and C2H4:O2:Ar mixtures has been studied experimentally and numerically after a high-voltage nanosecond discharge. The ignition delay time behind a reflected shock wave was measured with and without the discharge. It was shown that the initiation of the discharge with a specific deposited energy of 10 - 30 mJ/cm3 leads to an order of magnitude decrease in the ignition delay time. Discharge processes and following chain chemical reactions with energy release were simulated. The generation of atoms, radicals and excited and charged particles was numerically simulated using the measured time - resolved discharge current and electric field in the discharge phase. The calculated densities of the active particles were used as input data to simulate plasma-assisted ignition. Good agreement was obtained between the calculated ignition delay times and the experimental data. It follows from the analysis of the calculated results that the main mechanism of the effect of gas discharge on the ignition of hydrocarbons is the electron impact dissociation of O2 molecules in the discharge phase. Detailed kinetic mechanism for plasma assisted ignition of hydrogen and ethene is elaborated and verified.

Electron-Impact-Ionization and Electron-Attachment Cross Sections of Radicals Important in Transient Gaseous Discharges.

DTIC Science & Technology

1988-02-05

for understanding the microscopic processes of electrical discharges and for designing gaseous discharge switches. High power gaseous discharge switches...half-maximum) energy resolution. The electron gun and ion extraction were of the same design of Srivastava at the Jet Propulsion Laboratory. Ions...photons. - The observed current switching can be applied to the design of discharge switches. Elec- tron transport parameters are needed for the

Solid discharge and landslide activity at basin scale

NASA Astrophysics Data System (ADS)

Ardizzone, F.; Guzzetti, F.; Iadanza, C.; Rossi, M.; Spizzichino, D.; Trigila, A.

2012-04-01

This work presents a preliminary analysis aimed at understanding the relationship between landslide sediment supply and sediment yield at basin scale in central and southern Italy. A database of solid discharge measurements regarding 116 gauging stations, located along the Apennines chain in Italy, has been compiled by investigating the catalogues, named Annali Idrologici, published by Servizio Idrografico e Mareografico Italiano in the period from 1917 to 1997. The database records several information about the 116 gauging stations, and especially reports the sediment yield monthly measurements (103 ton) and the catchments area (km2). These data have been used to calculate the average solid yield and the normalized solid yield for each station in the observation period. The Italian Landslide Inventory (Progetto IFFI) has been used to obtained the size of the landslides, in order to estimate the landslide mobilization rates. The IFFI Project funded by the Italian Government is realized by ISPRA (Italian National Institute for Environmental Protection and Research - Geological Survey of Italy) in partnership with the 21 Regions and Self Governing Provinces. 21 of the 116 gauging stations and the related catchments have been selected on the basis of the length of the solid discharge observation period and excluding the catchments with dams located upstream the stations. The landslides inside the selected catchments have been extracted from the IFFI inventory, calculating the planimetric area of each landslide. Considering both the shallow and deep landslides, the landslide volume has been estimated using an empirical power law relation (landslide area vs. volume). The total landslide volume in the study areas and the average sediment yield measured at the gauging stations have been compared, analysing the behaviour of the basins which drainage towards the Tyrrhenian sea and the basins which drainage towards the Adriatic sea.

Dust particle radial confinement in a dc glow discharge.

PubMed

Sukhinin, G I; Fedoseev, A V; Antipov, S N; Petrov, O F; Fortov, V E

2013-01-01

A self-consistent nonlocal model of the positive column of a dc glow discharge with dust particles is presented. Radial distributions of plasma parameters and the dust component in an axially homogeneous glow discharge are considered. The model is based on the solution of a nonlocal Boltzmann equation for the electron energy distribution function, drift-diffusion equations for ions, and the Poisson equation for a self-consistent electric field. The radial distribution of dust particle density in a dust cloud was fixed as a given steplike function or was chosen according to an equilibrium Boltzmann distribution. The balance of electron and ion production in argon ionization by an electron impact and their losses on the dust particle surface and on the discharge tube walls is taken into account. The interrelation of discharge plasma and the dust cloud is studied in a self-consistent way, and the radial distributions of the discharge plasma and dust particle parameters are obtained. It is shown that the influence of the dust cloud on the discharge plasma has a nonlocal behavior, e.g., density and charge distributions in the dust cloud substantially depend on the plasma parameters outside the dust cloud. As a result of a self-consistent evolution of plasma parameters to equilibrium steady-state conditions, ionization and recombination rates become equal to each other, electron and ion radial fluxes become equal to zero, and the radial component of electric field is expelled from the dust cloud.

Facilitating the Timely Discharge of Well Newborns by Using Quality Improvement Methods.

PubMed

Rochester, Nicole T; Banach, Laurie P; Hoffner, Wendy; Zeltser, Deena; Lewis, Phyllis; Seelbach, Elizabeth; Cuzzi, Sandra

2018-05-01

Discharges are a key driver of hospital throughput. Our pediatric hospitalist team sought to improve newborn nursery throughput by increasing the percentage of newborns on our service with a discharge order by 11 am. We hypothesized that implementing a discharge checklist would result in earlier discharge times for newborns who met discharge criteria. We identified barriers to timely discharge through focus groups with key stakeholders, chart reviews, and brainstorming sessions. We subsequently created and implemented a discharge checklist to identify and address barriers before daily rounds. We tracked mean monthly discharge order times. Finally, we performed chart reviews to determine causes for significantly delayed discharge orders and used this information to modify rounding practices during a second plan-do-study-act cycle. During the 2-year period before the intervention, 24% of 3224 newborns had a discharge order entered by 11 am. In the 20 months after the intervention, 39% of 2739 newborns had a discharge order by 11 am, a 63% increase compared with the baseline. Observation for group B Streptococcus exposure was the most frequent reason for a late discharge order. There are many factors that affect the timely discharge of well newborns. The development and implementation of a discharge checklist improved our ability to discharge newborns on our pediatric hospitalist service by 11 am. Future studies to identify nonphysician barriers to timely newborn discharges may lead to further improvements in throughput between the labor and delivery and maternity suites units. Copyright © 2018 by the American Academy of Pediatrics.

How does a probe inserted into the discharge influence the plasma structure?

NASA Astrophysics Data System (ADS)

Yordanov, D.; Lishev, St.; Shivarova, A.

2016-05-01

Shielding the bias applied to the probe by the sheath formed around it and determination of parameters of unperturbed plasmas are in the basis of the probe diagnostics. The results from a two-dimensional model of a discharge with a probe inserted in it show that the probe influences the spatial distribution of the plasma parameters in the entire discharge. The increase (although slight) in the electron temperature, due to the increased losses of charged particles on the additional wall in the discharge (mainly the probe holder), leads to redistribution of the plasma density and plasma potential, as shown by the results obtained at the floating potential of the probe. The deviations due to the bias applied to the probe tip are stronger in the ion saturation region of the probe characteristics. The pattern of the spatial redistribution of the plasma parameters advances together with the movement of the probe deeper in the discharge. Although probe sheaths and probe characteristics resulting from the model are shown, the study does not aim at discussions on the theories for determination of the plasma density from the ion saturation current. Regardless of the modifications in the plasma behavior in the entire discharge, the deviations of the plasma parameters at the position of the probe tip and, respectively, the uncertainty which should be added as an error when the accuracy of the probe diagnostics is estimated do not exceed 10%. Consequently, the electron density and temperature obtained, respectively, at the position of the plasma potential on the probe characteristics and from its transition region are in reasonable agreement with the results from the model of the discharge without a probe. Being in the scope of research on a source of negative hydrogen ions with the design of a matrix of small radius inductive discharges, the model is specified for a low-pressure hydrogen discharge sustained in a small-radius tube.

N-heptane decomposition in multi-needle to plate electrical discharge

NASA Astrophysics Data System (ADS)

Pekarek, Stanislav; Pospisil, Milan

2003-10-01

Plasma based technologies are becoming more and more important for destruction of volatile organic compounds in air streams. The most frequent electrical discharges tested for VOC decomposition are corona and dielectric barrier discharge. We proposed [1] multi-hollow needles to plate atmospheric pressure discharge enhanced by the flow of the mixture of air with VOC through the needles. In this case all reactive mixture will pass through the active zone of the discharge. The high-speed gas flow near the exit of the needle will also efficiently cool the electrodes. Hence the higher values of the discharge current can be obtained without the danger of the discharge transition to the spark. The chemical reactions leading to the VOC decomposition can therefore be enhanced [2]. We performed an experimental study of the n-heptane decomposition efficiency on its concentration in air in the input of the discharge. We choose n-heptane, an important part of organic solvents and part of automotive fuels, as a representative of saturated alkanes. We found that with decreasing n-heptane concentration the decomposition efficiency increases. Acknowledgement: This work was supported by the research program No: J04/98:212300016 "Pollution control and monitoring of the Environment" of the Czech Technical University in Prague. References [1] S. Pekárek, V. Køíha, M. Pospíil - J. Physics D, Appl. Physics, 34, 117 (2001). [2] O. Goosens, T. Callebaut, Y. Akishev, C. Leys - IEEE Trans. Plasma Sc. 30, 176 (2002).

Long recovery VLF perturbations associated with lightning discharges

NASA Astrophysics Data System (ADS)

Salut, M. M.; Abdullah, M.; Graf, K. L.; Cohen, M. B.; Cotts, B. R. T.; Kumar, Sushil

2012-08-01

Long D-region ionospheric recovery perturbations are a recently discovered and poorly understood subcategory of early VLF events, distinguished by exceptionally long ionospheric recovery times of up to 20 min (compared to more typical ˜1 min recovery times). Characteristics and occurrence rates of long ionospheric recovery events on the NWC transmitter signal recorded at Malaysia are presented. 48 long recovery events were observed. The location of the causative lightning discharge for each event is determined from GLD360 and WWLLN data, and each discharge is categorized as being over land or sea. Results provide strong evidence that long recovery events are attributed predominately to lightning discharges occurring over the sea, despite the fact that lightning activity in the region is more prevalent over land. Of the 48 long recovery events, 42 were attributed to lightning activity over water. Analysis of the causative lightning of long recovery events in comparison to all early VLF events reveals that these long recovery events are detectable for lighting discharges at larger distances from the signal path, indicating a different scattering pattern for long recovery events.

Pattern formation based on complex coupling mechanism in dielectric barrier discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Weibo; College of Aeronautical Engineering, Binzhou University, Binzhou 256603; Dong, Lifang, E-mail: donglfhbu@163.com, E-mail: pyy1616@163.com

2016-08-15

The pattern formation of cinque-dice square superlattice pattern (CDSSP) is investigated based on the complex coupling mechanism in a dielectric barrier discharge (DBD) system. The spatio-temporal structure of CDSSP obtained by using an intensified-charge coupled device indicates that CDSSP is an interleaving of two kinds of subpatterns (mixture of rectangle and square, and dot-line square) which discharge twice in one half voltage, respectively. Selected by the complex coupling of two subpatterns, the CDSSP can be formed and shows good stability. This investigation based on gas discharge theory together with nonlinear theory may provide a deeper understanding for the nonlinear characteristicsmore » and even the formation mechanism of patterns in DBD.« less

Electron heating and the Electrical Asymmetry Effect in capacitively coupled RF discharges

NASA Astrophysics Data System (ADS)

Schulze, Julian

2011-10-01

For applications of capacitive radio frequency discharges, the control of particle distribution functions at the substrate surface is essential. Their spatio-temporal shape is the result of complex heating mechanisms of the respective species. Enhanced process control, therefore, requires a detailed understanding of the heating dynamics. There are two known modes of discharge operation: α- and γ-mode. In α-mode, most ionization is caused by electron beams generated by the expanding sheaths and field reversals during sheath collapse, while in γ-mode secondary electrons dominate the ionisation. In strongly electronegative discharges, a third heating mode is observed. Due to the low electron density in the discharge center the bulk conductivity is reduced and a high electric field is generated to drive the RF current through the discharge center. In this field, electrons are accelerated and cause significant ionisation in the bulk. This bulk heating mode is observed experimentally and by PIC simulations in CF4 discharges. The electron dynamics and mode transitions as a function of driving voltage and pressure are discussed. Based on a detailed understanding of the heating dynamics, the concept of separate control of the ion mean energy and flux in classical dual-frequency discharges is demonstrated to fail under process relevant conditions. To overcome these limitations of process control, the Electrical Asymmetry Effect (EAE) is proposed in discharges driven at multiple consecutive harmonics with adjustable phase shifts between the driving frequencies. Its concept and a recipe to optimize the driving voltage waveform are introduced. The functionality of the EAE in different gases and first applications to large area solar cell manufacturing are discussed. Finally, limitations caused by the bulk heating in strongly electronegative discharges are outlined.

Discharge dynamics of pin-to-plate dielectric barrier discharge at atmospheric pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun Liqun; Huang, Xiaojiang; Member of Magnetic Confinement Fusion Research Center, Ministry of Education of the People's Republic of China, Shanghai 201620

2010-11-15

The discharge dynamics of pin-to-plate dielectric barrier discharge was studied in atmospheric helium at 20 kHz. The discharge was predominately ignited in positive half cycle of applied voltage with sinusoidal waveform. The temporal evolution of the discharge was investigated vertically along the discharge gap and radically on the dielectric surface by time resolved imaging. It is found that a discharge column with a diameter of 2 mm was ignited above the pin electrode and expanded toward a plate electrode. On the dielectric surface with space charge accumulation, plasma disk in terms of plasma ring was formed with radius up tomore » 25 mm. The expansion velocity of plasma ring can reach a hypersonic speed of 3.0 km/s. The ionization wave due to electron diffusion is considered to be the mechanism for plasma ring formation and dynamics.« less

Tennis elbow surgery - discharge

MedlinePlus

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

Soil thaw effects on river discharge recessions of a subarctic catchment

NASA Astrophysics Data System (ADS)

Ploum, Stefan; Lyon, Steve; Teuling, Ryan; van der Velde, Ype

2017-04-01

Thawing permafrost in circumpolar regions is likely to change subsurface hydrology. In high latitude areas continuous permafrost is expected to partially thaw leading to sporadic permafrost with deeper groundwater flow paths. Moreover, freeze-thaw cycles of the shallow subsurface are likely to increase. River discharge recession analysis can be particularly useful to understand the hydrological effects of a thawing Arctic. Here we examine river discharge recessions of the Abiskojokka, a 560 km2 watershed with sporadic permafrost, using a river discharge record of 30 years (1985 - 2015). Snow observation records were used to separate river recessions in snowmelt and snowfree periods. We found significant differences between recessions during the snowmelt and snowfree seasons. During the snowmelt, recessions were close to linear (b=1.11), while during the snowfree period, recessions were more non-linear (b=1.54). Typically, non-linearity has been found to increase with discharge magnitude, while we observed the opposite (snowfree periods tend to have lower discharges than the snowmelt periods). We explain these contrasting results by hypothesizing that increased connectivity (increasing magnitude and number of water flow paths) between groundwater and stream leads to higher non-linearity. In temperate catchments without frozen soils, connectivity tends to increase with increasing discharge. In contrast, in Arctic systems, where soils are frozen, connectivity between groundwater and stream is limited. Therefore, thawing of frozen soils is expected to increase connectivity and thus non-linearity of river discharges. We tested this hypothesis with a detailed analysis of all spring flood recessions. Years with cold soil temperatures (b=1.08) and years with a below median snowpack depth were found to have progressively linear slopes (b=1.08 and 1.01 respectively). On the other hand, years with warm soil conditions show increasingly non-linear recessions (b=1.67). Although

Assessing infant and maternal readiness for newborn discharge.

PubMed

Jing, Ling; Bethancourt, Casidhe-Nicole; McDonagh, Thomas

2017-10-01

The review highlights the shift from prescribed length of stay (LOS) to mother-infant dyad readiness as the basis for making discharge decisions for healthy term newborns. We describe the components of readiness that should be considered in making the decision, focusing on infant clinical readiness, and maternal and familial readiness. Although the Newborns' and Mothers' Health Protection Act of 1996 aimed to protect infants and mothers by establishing a minimum LOS, the American Academy of Pediatrics 2015 policy on newborn discharge acknowledges the shift from LOS-based to readiness-based discharge decision-making. Healthcare providers must consider a variety of infant and maternal characteristics in determining the appropriate time to discharge a dyad, and mothers should be actively involved in the decision-making process. Criteria for infant clinical readiness include the following: establishment of effective feeding, evaluation of jaundice risk, review and discussion of infant and household vaccination status, obtainment of specimen for metabolic screening, tests of hearing ability, assessment of sepsis risk factors, screening for congenital heart disease, and evaluation of parental knowledge about infant safety measures. Important consideration should also be given to the mother's sociodemographic vulnerabilities, maternal confidence and perception of discharge readiness, and availability of postdischarge care continuity. The timing of newborn discharge should be a joint decision made by the mother and healthcare providers based on readiness. The decision should consider the infant's health status, the mother's health status, the mother's perception of readiness, and the availability of social and familial support for the mother and infant. Accessible and comprehensive support postdischarge is also important for helping infants achieve optimal health outcomes.

Stimulus-Induced Rhythmic, Periodic, or Ictal Discharges (SIRPIDs).

PubMed

Johnson, Emily L; Kaplan, Peter W; Ritzl, Eva K

2018-05-01

Stimulus-induced rhythmic, periodic, or ictal discharges (SIRPIDs) are a relatively common phenomenon found on prolonged electroencephalogram (EEG) monitoring that captures state changes and stimulation of critically ill patients. Common causes include hypoxic injury, traumatic brain injury, and hemorrhage, as well as toxic-metabolic disturbances. Some studies have shown an association between SIRPIDs and the presence of spontaneous electrographic seizures. Although the degree to which SIRPIDs should be treated with antiepileptic medications is unknown, the rare cases of functional imaging obtained in patients with SIRPIDs have not shown an increase in cerebral blood flow to suggest an active ictal process. Stimulus-induced rhythmic, periodic, or ictal discharges may reflect dysregulation of thalamo-cortical projections into abnormal or hyperexcitable cortex.

Older veterans and emergency department discharge information.

PubMed

Hastings, Susan; Stechuchak, Karen; Oddone, Eugene; Weinberger, Morris; Tucker, Dana; Knaack, William; Schmader, Kenneth

2012-10-01

Study goals were to assess older veterans' understanding of their emergency department (ED) discharge information and to determine the association between understanding discharge information and patient assessment of overall quality of care. Telephone interviews were conducted with 305 patients aged 65 or older (or their proxies) within 48 h of discharge from a Veterans Affairs Medical Center ED. Patients were asked about their perceived understanding (at the time of ED discharge) of information about their ED diagnosis, expected course of illness, contingency plan (ie, return precautions, who to call if it got worse, potential medication side effects) and follow-up care. Overall quality of ED care was rated on a four-point scale of poor, fair, good or excellent. Patients or their proxies reported not understanding information about their ED diagnosis (21%), expected course of illness (50%), contingency plan (43%), and how soon they needed to follow-up with their primary care provider (25%). In models adjusted for age and race, a positive association was observed between perceived understanding of the cause of the problem (OR 2.3; 95% CI 1.3 to 4.0), expected duration of symptoms (OR 1.6; 95% CI 1.0 to 2.5) and the contingency plan (OR 2.2; CI 1.3 to 3.4), and rating overall ED care as excellent. Older veterans may not understand key items of information at the time ED discharge, and this may have an impact on how they view the quality of ED care. Strategies are needed to improve communication of ED discharge information to older veterans and their families.

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

DOE PAGES

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

2017-06-07

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

Transition from Townsend to radio-frequency homogeneous dielectric barrier discharge in a roll-to-roll configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bazinette, R.; SIAME, Université de Pau et des Pays de l'Adour, Pau; Paillol, J.

The aim of this paper is to better understand the transition from Townsend to radio-frequency homogeneous dielectric barrier discharge (DBD) at atmospheric pressure. The study is done in an Ar/NH{sub 3} Penning mixture for an electrode configuration adapted to roll-to-roll plasma surface treatment. The study was led in a frequency range running from 50 kHz up to 8.3 MHz leading to different DBD modes with a 1 mm gas gap: Glow (GDBD), Townsend (TDBD), and Radio-frequency (RF-DBD). In the frequency range between TDBD and RF-DBD, from 250 kHz to 2.3 MHz, additional discharges are observed outside the inter-electrode gas gap. Because each high voltagemore » electrode are inside a dielectric barrel, these additional discharges occur on the side of the barrel where the gap is larger. They disappear when the RF-DBD mode is attained in the 1 mm inter-electrode gas gap, i.e., for frequencies equal or higher than 3 MHz. Fast imaging and optical emission spectroscopy show that the additional discharges are radio-frequency DBDs while the inter-electrode discharge is a TDBD. The RF-DBD discharge mode is attained when electrons drift becomes low enough compared to the voltage oscillation frequency to limit electron loss at the anode. To check that the additional discharges are due to a larger gas gap and a lower voltage amplitude, the TDBD/RF-DBD transition is investigated as a function of the gas gap and the applied voltage frequency and amplitude. Results show that the increase in the frequency at constant gas gap or in the gas gap at constant frequency allows to obtain RF-DBD instead of TDBD. At low frequency and large gap, the increase in the applied voltage allows RF-DBD/TDBD transition. As a consequence, an electrode configuration allowing different gap values is a solution to successively have different discharge modes with the same applied voltage.« less

Estimating river discharge uncertainty by applying the Rating Curve Model

NASA Astrophysics Data System (ADS)

Barbetta, S.; Melone, F.; Franchini, M.; Moramarco, T.

2012-04-01

The knowledge of the flow discharge at a river site is necessary for planning and management of water resources as well as for monitoring and real-time forecasting purposes when significant flood events occur. In the hydrological practice, the operational discharge measurement in medium and large rivers is mostly based on indirect approaches by converting the observed stage into discharge values using steady-flow rating curves. However, the stage-discharge relationship can be unknown for hydrometric sections where flow velocity measurements, particularly during high floods, are not available. To overcome this issue, a simplified approach named Rating Curve Model (RCM) and proposed by Moramarco et al. (Moramarco, T., Barbetta, S., F. Melone, F. & Singh, V.P., Relating local stage and remote discharge with significant lateral inflow, J. Hydrol. Engng ASCE, 10[1], 58?69, 2005) can be conveniently used. RCM turned out able to assess, with a high level of accuracy, the discharge hydrograph at a river site where only the stage is monitored while the flow is recorded at a different section along the river, even when significant lateral flows occur. The simple structure of the model is depending on three parameters of which two can be considered characteristic of the river reach and one of the wave travel time of floods. Considering that RCM well lends itself to predict the stage-discharge relationship at a river site wherein only stages are recorded, an uncertainty analysis on river discharge estimate is of interest for the hydrological practice definitely. To this aim, the uncertainty characterizing the RCM outcomes is addressed in this work by considering two different procedures based on the Monte Carlo approach and the Generalized Likelihood Uncertainty Estimation (GLUE) method, respectively. The statistical distribution of parameters is found and a random re-sampling of parameters is done for assessing the 90% confidence interval (CI) of discharge estimates. In

Modelling Of Chlorine Inductive Discharges

NASA Astrophysics Data System (ADS)

Chabert P.; Despiau-Pujo, E.

2010-07-01

III-V compounds such as GaAs, InP or GaN-based materials are increasingly important for their use in optoelectronic applications, especially in the telecommunications and light detection industries. Photonic devices including lasers, photodetectors or LEDs, require reliable etching processes characterized by high etch rate, profile control and low damage. Although many problems remain to be understood, inductively coupled discharges seem to be promising to etch such materials, using Cl2/Ar, Cl2/N2 and Cl2/H2 gas chemistries. Inductively coupled plasma (ICP) sources meet most of the requirements for efficient plasma processing such as high etch rates, high ion densities and low controllable ion energies. However, the presence of a negative ion population in the plasma alters the positive ion flux, reduces the electron density, changes the electron temperature, modifies the spatial structure of the discharge and can cause unstable operation. Several experimental studies and numerical simulation results have been published on inductively coupled Cl2/Ar plasmas but relatively few systematic comparisons of model predictions and experimental data have been reported in given reactor geometries under a wide range of op- erating conditions. Validation of numerical predictions is essential for chemically complex plasma processing and there is a need to benchmark the models with as many measurements as possible. In this paper, comparisons of 2D fluid simulations with experimental measurements of Ar/Cl2 plasmas in a low pressure ICP reactor are reported (Corr et al. 2008). The electron density, negative ion fraction and Cl atom density are investigated for various conditions of Ar/Cl2 ratio, gas pressure and applied RF power in H mode. Simulations show that the wall recombination coefficient of Cl atom (?) is a key parameter of the model and that neutral densities are very sensitive to its variations. The best agreement between model and experiment is obtained for ? = 0

Spatiotemporal interpolation of discharge across a river network by using synthetic SWOT satellite data

NASA Astrophysics Data System (ADS)

Paiva, Rodrigo C. D.; Durand, Michael T.; Hossain, Faisal

2015-01-01

Recent efforts have sought to estimate river discharge and other surface water-related quantities using spaceborne sensors, with better spatial coverage but worse temporal sampling as compared with in situ measurements. The Surface Water and Ocean Topography (SWOT) mission will provide river discharge estimates globally from space. However, questions on how to optimally use the spatially distributed but asynchronous satellite observations to generate continuous fields still exist. This paper presents a statistical model (River Kriging-RK), for estimating discharge time series in a river network in the context of the SWOT mission. RK uses discharge estimates at different locations and times to produce a continuous field using spatiotemporal kriging. A key component of RK is the space-time river discharge covariance, which was derived analytically from the diffusive wave approximation of Saint Venant's equations. The RK covariance also accounts for the loss of correlation at confluences. The model performed well in a case study on Ganges-Brahmaputra-Meghna (GBM) River system in Bangladesh using synthetic SWOT observations. The correlation model reproduced empirically derived values. RK (R2=0.83) outperformed other kriging-based methods (R2=0.80), as well as a simple time series linear interpolation (R2=0.72). RK was used to combine discharge from SWOT and in situ observations, improving estimates when the latter is included (R2=0.91). The proposed statistical concepts may eventually provide a feasible framework to estimate continuous discharge time series across a river network based on SWOT data, other altimetry missions, and/or in situ data.

ACL reconstruction - discharge

MedlinePlus

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

Transport modeling of L- and H-mode discharges with LHCD on EAST

NASA Astrophysics Data System (ADS)

Li, M. H.; Ding, B. J.; Imbeaux, F.; Decker, J.; Zhang, X. J.; Kong, E. H.; Zhang, L.; Wei, W.; Shan, J. F.; Liu, F. K.; Wang, M.; Xu, H. D.; Yang, Y.; Peysson, Y.; Basiuk, V.; Artaud, J.-F.; Yuynh, P.; Wan, B. N.

2013-04-01

High-confinement (H-mode) discharges with lower hybrid current drive (LHCD) as the only heating source are obtained on EAST. In this paper, an empirical transport model of mixed Bohm/gyro-Bohm for electron and ion heat transport was first calibrated against a database of 3 L-mode shots on EAST. The electron and ion temperature profiles are well reproduced in the predictive modeling with the calibrated model coupled to the suite of codes CRONOS. CRONOS calculations with experimental profiles are also performed for electron power balance analysis. In addition, the time evolutions of LHCD are calculated by the C3PO/LUKE code involving current diffusion, and the results are compared with experimental observations.

Examination about the Spatial Representation of PM2.5 Obtained from Limited Stations Using a Network Observation

NASA Astrophysics Data System (ADS)

Shi, X.; Zhao, C.

2017-12-01

Haze aerosol pollution has been a focus issue in China, and its characteristics is highly demanded. With limited observation sites, aerosol properties obtained from a single site is frequently used to represent the haze condition over a large domain, such as tens of kilometers. This could result in high uncertainties in the haze characteristics due to their spatial variation. Using a network observation from November 2015 to February 2016 over an urban city in North China with high spatial resolution, this study examines the spatial representation of ground site observations. A method is first developed to determine the representative area of measurements from limited stations. The key idea of this method is to determine the spatial variability of particulate matter with diameters less than 2.5 μm (PM2.5) concentration using a variance function in 2km x 2km grids. Based on the high spatial resolution (0.5km x 0.5km) measurements of PM2.5, the grids in which PM2.5 have high correlations and weak value differences are determined as the representation area of measurements at these grids. Note that the size representation area is not exactly a circle region. It shows that the size representation are for the study region and study period ranges from 0.25 km2 to 16.25 km2. The representation area varies with locations. For the 20 km x 20 km study region, 10 station observations would have a good representation of the PM2.5 observations obtained from current 169 stations at the four-month time scale.

The effect of temperature on pulsed positive streamer discharges in air over the range 292 K–1438 K

NASA Astrophysics Data System (ADS)

Ono, Ryo; Ishikawa, Yuta

2018-05-01

The effect of temperature on pulsed positive streamer discharges in air is measured by comparing atmospheric-pressure, high-temperature discharges with low-pressure, room-temperature discharges at the same air densities n and discharge voltages. Both discharges have the same reduced electric field E/n, so the differences between the two discharges only depend on the temperature, which is varied from 292 K to 1438 K. Temperature affects the discharge pulse energy most significantly; at 1438 K, the energy of an atmospheric-pressure discharge pulse is approximately 30 times larger than that of the corresponding 20.5 kPa, room-temperature discharge. Temperature also affects the shapes of the streamers when K, but no significant effect is observed for K. There is also no significant temperature effect on the spatially integrated intensity of N2(C–B) emission. However, temperature strongly affects the ratio of the integrated emission intensity to the discharge energy. No effect of the temperature is observed on the propagation velocity of the primary streamer or on the length of the secondary streamer.

[Isolation of Gardnerella vaginalis from vaginal discharge specimens].

PubMed

Köksalan, H; Esen, N; Cağatay, M; Tülek, N; Mert, A

1993-07-01

In this study specimens taken from 93 patients who admitted to outpatient clinics of SSK Ankara Gynaecology and Obstetrics Hospital with vaginal discharge were examined for G. vaginalis, T. vaginalis, C. albicans and N. gonorrhoeae. We evaluated the smell, pH, direct microscopic examinations, stained preparations and specific culture results of the discharges which were taken from posterior fornix. We isolated G. vaginalis from 13 patients (13.9%), T. vaginalis from 5 patients (5.3%) and C. albicans from 19 patients (20.4%). N. gonorrhoeae could not be isolated from any of the specimens. In our control study, we isolated G. vaginalis in three out of 50 patients (6%) without vaginal discharge. We observed T. vaginalis in specimens of 3 control patients. C. albicans and N. gonorrhoeae could not be isolated in this study in this study.

Two-dimensional simulation of discharge channels in atmospheric-pressure single dielectric barrier discharges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Jiao; Wang, Yanhui, E-mail: wangyh@dlut.edu.cn; Wang, Dezhen, E-mail: wangdez@dlut.edu.cn

A two-dimensional fluid model is developed to study the filaments (or discharge channels) in atmospheric-pressure discharge with one plate electrode covered by a dielectric layer. Under certain discharge parameters, one or more stable filaments with wide radii could be regularly arranged in the discharge space. Different from the short-lived randomly distributed microdischarges, this stable and thick filament can carry more current and have longer lifetime. Because only one electrode is covered by a dielectric layer in the simulation, the formed discharge channel extends outwards near the dielectric layer and shrinks inwards near the naked electrode, agreeing with the experimental results.more » In this paper, the evolution of channel is studied, and its behavior is like a streamer or an ionization wave, but the propagation distance is short. The discharge parameters such as voltage amplitude, electrode width, and N{sub 2} impurities content could significantly influence the number of discharge channel, which is discussed in the paper.« less

Preliminary Studies on Aerodynamic Control with Direct Current Discharge at Hypersonic Speed

NASA Astrophysics Data System (ADS)

Watanabe, Yasumasa; Takama, Yoshiki; Imamura, Osamu; Watanuki, Tadaharu; Suzuki, Kojiro

A new idea of an aerodynamic control device for hypersonic vehicles using plasma discharges is presented. The effect of DC plasma discharge on a hypersonic flow is examined with both experiments and CFD analyses. It is revealed that the surface pressure upstream of plasma area significantly increases, which would be preferable in realizing a new aerodynamic control devices. Such pressure rise is also observed in the result of analyses of the Navier-Stokes equations with energy addition that simulates the Joule heating of a plasma discharge. It is revealed that the pressure rise due to the existence of the plasma discharge can be qualitatively explained as an effect of Joule heating.

EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Dynamics of a plasma formed by a surface optical-discharge in a metal vapour interacting with a cw CO2 laser beam

NASA Astrophysics Data System (ADS)

Zaikin, A. E.; Levin, A. V.; Petrov, A. L.

1995-02-01

A surface optical-discharge plasma was formed in a metal vapour under normal conditions by steady-state irradiation with a cw CO2 laser delivering radiation of moderate (2-4.5 MW cm-2) intensity. This plasma strongly screened the irradiated surface. Under the selected experimental conditions the optical discharge was not a continuous (steady-state) process. The plasma cloud was displaced along the beam out of the waist to a region where the laser radiation intensity was almost an order of magnitude less than the threshold for excitation of the optical-discharge plasma in the vapour. A strong screening of the metal surface, which could even completely stop evaporation of the metal, was observed. Self-oscillations of the optical-discharge plasma were observed for the first time in a vapour interacting with cw CO2 radiation: this was attributed to screening of the target surface. Within one period of the self-oscillations there were additional hf plasma pulsations which led to stratification of the plasma cloud. The results obtained were interpreted.

Characteristics of radio-frequency atmospheric pressure dielectric-barrier discharge with dielectric electrodes

NASA Astrophysics Data System (ADS)

Hussain, S.; Qazi, H. I. A.; Badar, M. A.

2014-03-01

An experimental investigation to characterize the properties and highlight the benefits of atmospheric pressure radio-frequency dielectric-barrier discharge (rf DBD) with dielectric electrodes fabricated by anodizing aluminium substrate is presented. The current-voltage characteristics and millisecond images are used to distinguish the α and γ modes. This atmospheric rf DBD is observed to retain the discharge volume without constriction in γ mode. Optical emission spectroscopy demonstrates that the large discharge current leads to more abundant reactive species in this plasma source.

Effects of physical and chemical heterogeneity on water-quality samples obtained from wells

USGS Publications Warehouse

Reilly, Thomas E.; Gibs, Jacob

1993-01-01

Factors that affect the mass of chemical constituents entering a well include the distributions of flow rate and chemical concentrations along and near the screened or open section of the well. Assuming a layered porous medium (with each layer being characterized by a uniform hydraulic conductivity and chemical concentration), a knowledge of the flow from each layer along the screened zone and of the chemical concentrations in each layer enables the total mass entering the well to be determined. Analyses of hypothetical systems and a site at Galloway, NJ, provide insight into the temporal variation of water-quality data observed when withdrawing water from screened wells in heterogeneous ground-water systems.The analyses of hypothetical systems quantitatively indicate the cause-and-effect relations that cause temporal variability in water samples obtained from wells. Chemical constituents that have relatively uniform concentrations with depth may not show variations in concentrations in the water discharged from a well after the well is purged (evacuation of standing water in the well casing). However, chemical constituents that do not have uniform concentrations near the screened interval of the well may show variations in concentrations in the well discharge water after purging because of the physics of ground-water flow in the vicinity of the screen.Water-quality samples were obtained through time over a 30 minute period from a site at Galloway, NJ. The water samples were analyzed for aromatic hydrocarbons, and the data for benzene, toluene, and meta+para xylene were evaluated for temporal variations. Samples were taken from seven discrete zones, and the flow-weighted concentrations of benzene, toluene, and meta+para xylene all indicate an increase in concentration over time during pumping. These observed trends in time were reproduced numerically based on the estimated concentration distribution in the aquifer and the flow rates from each zone.The results of

Investigation on the Micro-Discharge Characteristics of Dielectric Barrier Discharge in a Needle-Plate Geometry

NASA Astrophysics Data System (ADS)

Li, Xuechen; Niu, Dongying; Jia, Pengying; Zhao, Na; Yuan, Ning

2011-04-01

In this study, a dielectric barrier discharge device with needle-plate electrodes was used to investigate the characteristics of the micro-discharge in argon at one atmospheric pressure by an optical method. The results show that there are two discharge modes in the dielectric barrier discharge, namely corona mode and filamentary mode. The corona discharge only occurs in the vicinity of the needle tip when the applied voltage is very low. However, the filamentary discharge mode can occur, and micro-discharge bridges the two electrodes when the applied voltage reaches a certain value. The extended area of micro-discharge on the dielectric plate becomes larger with the increase in applied voltage or decrease in gas pressure. The variance of the light emission waveforms is studied as a function of the applied voltage. Results show that very narrow discharge pulse only appears at the negative half cycle of the applied voltage in the corona discharge mode. However, broad hump (about several microseconds) can be discerned at both the negative half cycle and the positive half cycle for a high voltage in the filamentary mode. Furthermore, the inception voltage decreases and the width of the discharge hump increases with the increase in applied voltage. These experimental phenomena can be explained qualitatively by analyzing the discharge mechanism.

Computations of total sediment discharge, Niobrara River near Cody, Nebraska

USGS Publications Warehouse

Colby, Bruce R.; Hembree, C.H.

1955-01-01

appreciable quantities. Hence, total sediment discharges were obtained by adding computed discharges of sediment larger than 0.125 millimeter to measured discharges of sediment smaller than 0.125 millimeter. The size distributions of the computed sediment discharge compared poorly with the size distributions of sediment discharge at the contracted section. Ten sediment discharges computed from the Einstein procedure as applied to a single section averaged several times the measured sediment discharge for the contracted section and gave size distributions that were unsatisfactory. The Einstein procedure was modified to compute total sediment discharge at an alluvial section from readily measurable field data. The modified procedure uses measurements of bed-material particle sizes, suspended-sediment concentrations and particle sizes from depth-integrated samples, streamflow, and water temperatures. Computations of total sediment discharge were made by using this modified procedure, some for the section at the gaging station and some for each of two other relatively unconfined sections. The size distributions of the computed and the measured sediment discharges agreed reasonably well. Major advantages of this modified procedure include applicability to a single section rather than to a reach of channel, use of measured velocity instead of water-surface slope, use of depth-integrated samples, and apparently fair accuracy for computing both total sediment discharge and approximate size distribution of the sediment. Because of these advantages this modified procedure is being further studied to increase its accuracy, to simplify the required computations, and to define its limitations. In the development of the modified procedure, some relationships concerning theories of sediment transport were reviewed and checked against field data. Vertical distributions of suspended sediment at relatively unconfined sections did not agree well with theoretical dist

Parental language and dosing errors after discharge from the pediatric emergency department.

PubMed

Samuels-Kalow, Margaret E; Stack, Anne M; Porter, Stephen C

2013-09-01

Safe and effective care after discharge requires parental education in the pediatric emergency department (ED). Parent-provider communication may be more difficult with parents who have limited health literacy or English-language fluency. This study examined the relationship between language and discharge comprehension regarding medication dosing. We completed a prospective observational study of the ED discharge process using a convenience sample of English- and Spanish-speaking parents of children 2 to 24 months presenting to a single tertiary care pediatric ED with fever and/or respiratory illness. A bilingual research assistant interviewed parents to ascertain their primary language and health literacy and observed the discharge process. The primary outcome was parental demonstration of an incorrect dose of acetaminophen for the weight of his or her child. A total of 259 parent-child dyads were screened. There were 210 potential discharges, and 145 (69%) of 210 completed the postdischarge interview. Forty-six parents (32%) had an acetaminophen dosing error. Spanish-speaking parents were significantly more likely to have a dosing error (odds ratio, 3.7; 95% confidence interval, 1.6-8.1), even after adjustment for language of discharge, income, and parental health literacy (adjusted odds ratio, 6.7; 95% confidence interval, 1.4-31.7). Current ED discharge communication results in a significant disparity between English- and Spanish-speaking parents' comprehension of a crucial aspect of medication safety. These differences were not explained purely by interpretation, suggesting that interventions to improve comprehension must address factors beyond language alone.

Mössbauer study of new vanadate glass with large charge-discharge capacity

NASA Astrophysics Data System (ADS)

Kubuki, Shiro; Masuda, Hitomi; Matsuda, Koken; Akiyama, Kazuhiko; Kitajo, Ayuko; Okada, Shigeto; Zsabka, Péter; Homonnay, Zoltán; Kuzmann, Ernõ; Nishida, Tetsuaki

2014-04-01

Charge-discharge capacity and cyclicity of lithium ion battery (LIB) was evaluated in which 15Li2O·10Fe2O3· xSnO2·5P2O5·(70- x)V2O5 glass ( x = 0 and 20 in mol%, abbreviated as xLFSPV) was used as a cathode. A local structure of xLFSPV glass before and after charging was investigated by 57Fe- and 119Sn-Mössbauer spectroscopies. 57Fe-Mössbauer spectrum of xLFSPV glass with ` x' of 20 was composed of a doublet with isomer shift ( δ) of 0.35±0.02 mm s - 1 and quadrupole splitting ( Δ) of 0.88±0.03 mm s - 1 due to distorted FeIIIO4 tetrahedra. 119Sn-Mössbauer spectrum of this glass consisted of a doublet with δ of 0.08±0.01 and Δ of 0.52±0.01 mms - 1 due to distorted SnVIO6 octahedra. After discharging the battery from 4.5 to 1.0 V, larger δ of 0.40±0.03 mm s - 1 and Δ of 0.94±0.04 mm s - 1 were obtained, indicating that both iconicity of Fe-O bonds and local distortion of FeIIIO4 tetrahedra were increased. On the contrary, identical δ of 0.09±0.01 mm s - 1 and Δ of 0.50±0.01 mm s - 1 were observed in the 119Sn-Mössbauer spectrum of 20LFSPV glass after the discharge, indicating that chemical environment of SnIVO6 octahedra was not affected after the discharge. Charge-discharge curve of LIB containing 20LFSPV glass as a cathode active material recorded under the current density of 8.3 mA g - 1 (0.011 mA cm - 2) between 1.0 and 4.5 V showed a large initial charge capacity of 431.1 mAh g - 1 and discharge capacity of 382.3 mAh g - 1, respectively. These results indicate that 20LFSPV glass could be a new cathode active material for LIB.

Branching Patterns and Stepped Leaders in an Electric-Circuit Model for Creeping Discharge

NASA Astrophysics Data System (ADS)

Hidetsugu Sakaguchi,; Sahim M. Kourkouss,

2010-06-01

We construct a two-dimensional electric circuit model for creeping discharge. Two types of discharge, surface corona and surface leader, are modeled by a two-step function of conductance. Branched patterns of surface leaders surrounded by the surface corona appear in numerical simulation. The fractal dimension of branched discharge patterns is calculated by changing voltage and capacitance. We find that surface leaders often grow stepwise in time, as is observed in lightning leaders of thunder.

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

NASA Astrophysics Data System (ADS)

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

2013-08-01

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

High-order harmonic generation in a capillary discharge

DOEpatents

Rocca, Jorge J.; Kapteyn, Henry C.; Mumane, Margaret M.; Gaudiosi, David; Grisham, Michael E.; Popmintchev, Tenio V.; Reagan, Brendan A.

2010-06-01

A pre-ionized medium created by a capillary discharge results in more efficient use of laser energy in high-order harmonic generation (HHG) from ions. It extends the cutoff photon energy, and reduces the distortion of the laser pulse as it propagates down the waveguide. The observed enhancements result from a combination of reduced ionization energy loss and reduced ionization-induced defocusing of the driving laser as well as waveguiding of the driving laser pulse. The discharge plasma also provides a means to spectrally tune the harmonics by tailoring the initial level of ionization of the medium.

Untangling the Herman-infrared spectra of nitrogen atmospheric-pressure dielectric-barrier discharge

NASA Astrophysics Data System (ADS)

Čermák, Peter; Annušová, Adriana; Rakovský, Jozef; Martišovitš, Viktor; Veis, Pavel

2018-05-01

This study presents the first application of the N2 Herman-infrared (HIR) ro-vibrational model for the metrology of the atmospheric-pressure dielectric-barrier discharge. Our recent findings of suitable conditions for observation of the unperturbed HIR system (Annušová et al Contrib. Plasma Phys. 2017) gave us the opportunity to develop and test a numerical representation of this complex system composed of 75 branches. Commonly, the HIR covers a part of the near infrared spectra (690–850 nm) with its bands mixed with the N2 first positive system (1PS), which hinders applications of these systems for optical metrology of the discharge. In this work, we present a complex ro-vibrational model of the 1PS and HIR systems, which allowed us to untangle their spectra and retrieve the rotational temperature and vibrational populations of the systems for the first time. The latter was achieved by coupling the PGHOPHER simulation package with molecular constants obtained from high-resolution experiments. To test the model, the results and precision were compared to the retrievals based on the models of the NO γ and N2 second positive systems using the LIFBASE and SPECAIR programs, respectively.

Early discharge of patients with pulmonary embolism in daily clinical practice: A prospective observational study comparing clinical gestalt and clinical rules.

PubMed

Vanni, Simone; Becattini, Cecilia; Nazerian, Peiman; Bova, Carlo; Stefanone, Valerio Teodoro; Cimini, Ludovica Anna; Viviani, Gabriele; Caviglioli, Cosimo; Sanna, Michela; Pepe, Giuseppe; Grifoni, Stefano

2018-05-08

To estimate the efficiency and safety of clinicians' gestalt in the identification of patients with pulmonary embolism (PE) candidates for early discharge and to compare the efficiency and safety of clinical gestalt with that of the Pulmonary Embolism Severity Index (PESI), the simplified PESI (sPESI) and the Hestia criteria (HC). Consecutive adult patients presenting to the emergency department of four Italian hospitals with confirmed diagnosis of PE were included. Data for PESI, sPESI and HC assessment were prospectively collected. Patients were managed according to the clinical gestalt of the attending physician, independent of the results of PESI, sPESI and HC. Efficiency was defined as the prevalence of candidates to early discharge. The primary safety measure was the incidence of a composite of venous thromboembolic recurrence, major haemorrhage or all-cause mortality within 30 days. Out of 547 included patients, 178 (32.5%) were judged to be at low risk and discharged within 48 h from presentation. HC identified a higher proportion (41.7%) whereas both PESI (24.1%) and sPESI (18.3%) identified a lower proportion of candidates for early discharge when compared to clinical gestalt (P < 0.01 for all). The incidence of the safety outcome was 2.8% in early-discharged patients according to clinical gestalt and 2.3%, 3.0% and 2.6% in candidates to early discharge according to PESI, sPESI and HC, without differences between strategies. In our cohort, clinical gestalt identified one-third of PE patients for early discharge. Among different strategies HC showed the highest efficiency sharing similar safety with the other strategies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hospitalist and Internal Medicine Leaders' Perspectives of Early Discharge Challenges at Academic Medical Centers.

PubMed

Patel, Hemali; Fang, Margaret C; Mourad, Michelle; Green, Adrienne; Wachter, Robert M; Murphy, Ryan D; Harrison, James D

2018-06-01

Improving early discharges may improve patient flow and increase hospital capacity. We conducted a national survey of academic medical centers addressing the prevalence, importance, and effectiveness of early-discharge initiatives. We assembled a list of hospitalist and general internal medicine leaders at 115 US-based academic medical centers. We emailed each institutional representative a 30-item online survey regarding early-discharge initiatives. The survey included questions on discharge prioritization, the prevalence and effectiveness of early-discharge initiatives, and barriers to implementation. We received 61 responses from 115 institutions (53% response rate). Forty-seven (77%) "strongly agreed" or "agreed" that early discharge was a priority. "Discharge by noon" was the most cited goal (n = 23; 38%) followed by "no set time but overall goal for improvement" (n = 13; 21%). The majority of respondents reported early discharge as more important than obtaining translators for non-English-speaking patients and equally important as reducing 30-day readmissions and improving patient satisfaction. The most commonly reported factors delaying discharge were availability of postacute care beds (n = 48; 79%) and patient-related transport complications (n = 44; 72%). The most effective early discharge initiatives reported involved changes to the rounding process, such as preemptive identification and early preparation of discharge paperwork (n = 34; 56%) and communication with patients about anticipated discharge (n = 29; 48%). There is a strong interest in increasing early discharges in an effort to improve hospital throughput and patient flow. © 2017 Society of Hospital Medicine.

Synthesis of oxide and nitride ceramics in high-power gyrotron discharge

NASA Astrophysics Data System (ADS)

Akhmadullina, N. S.; Skvortsova, N. N.; Obraztsova, E. A.; Stepakhin, V. D.; Konchekov, E. M.; Kargin, Yu F.; Shishilov, O. N.

2017-12-01

Synthesis of oxides, nitrides, and oxynitrides of silicon and aluminium by a pulsed microwave discharge in the mixtures of metal and dielectric powders is described. The microwave pulses were generated by high-power gyrotron (frequency 75 GHz, power up to 550 kW, pulse duration from 0.1 to 15ms). SiO2 + β-Si3N4 (1:1 by molar) and α-Al2O3 + AlN (2:1 by molar) mixtures with Mg (1 and 5wt%) were treated in air with microwave pulses with power of 250÷400 kW and duration of 2÷8 ms. It was found that the discharge cannot be initiated for both mixtures in absence of Mg at any pulse power and duration. When 1% of Mg was added, the discharge was observed for both mixtures under 8 ms pulses of 400 kW; however, the amounts of materials produced were not enough for analysis. With 5% of Mg the discharge was observed for both mixtures under 8 ms pulses of 350 kW, and products of the plasma-chemical processes in the Al2O3 + AlN mixture were analyzed.

Discharge formation in a XеCl laser pumped by high specific power

NASA Astrophysics Data System (ADS)

Panchenko, Yu. N.; Losev, V. F.

2013-02-01

Stable glow of the discharge of various types in the gas mixture of a XeCl laser is investigated for specific pumping power in the range 1.2-4.6 MW/cm3 and pulse duration of 40 ns. It is demonstrated that formation of partially homogeneous plasma with many intensive cathode spots on the electrode allows the maximum energy and duration of the lasing pulse to be obtained with laser efficiency of 2.4%. It is revealed that for the specific pumping powers up to 1.5 MW/cm3, a very homogeneous volume discharge with a small number of lowintensive cathode spots is formed in the discharge gap. With further increase in the specific pumping power exceeding 4.5 MW/cm3, current microinhomogeneities are formed in the volume discharge of this type leading to lasing breakdown.

Sputter erosion and deposition in the discharge chamber of a small mercury ion thruster

NASA Technical Reports Server (NTRS)

Power, J. L.

1973-01-01

A 5 cm diameter mercury ion thruster similar to one tested for 9715 hours was operated approximately 400 hrs each at discharge voltages of 36.6, 39.6, and 42.6 V, with corresponding discharge propellant utilizations of 58, 68, and 70 percent. The observed sputter erosion rates of the internal thruster parts and the anode weight gain rate all rose rapidly with discharge voltage and were roughly in the ratio of 1:3:5 for the three voltages. The combined weight loss of the internal thruster parts nearly balanced the anode weight gain. Hg(+2) ion apparently caused most of the observed erosion.

Which Reasons Do Doctors, Nurses, and Patients Have for Hospital Discharge? A Mixed-Methods Study

PubMed Central

Ubbink, Dirk T.; Tump, Evelien; Koenders, Josje A.; Kleiterp, Sieta; Goslings, J. Carel; Brölmann, Fleur E.

2014-01-01

Background The decision to discharge a patient from a hospital is a complex process governed by many medical and non-medical factors, while the actual reasons for discharge frequently remain ill-defined. Aim To define relevant discharge criteria as perceived by doctors, nurses and patients for the development of a standard hospital discharge policy, we collected actual reasons and most pivotal medical and organisational criteria for discharge among all stakeholders. Setting A tertiary referral university teaching hospital. Methods We conducted a mixed methods analysis, using patient questionnaires, interviews and a focus group with caregivers, and observations during the daily rounds of doctors, nurses and patients during their hospital stay. Fourteen wards of the Surgery, Paediatrics and Neurology departments contributed. Results We observed 426 patients during their hospital stay. Forty doctors and nurses were interviewed, and 7 senior nurses attended a focus group. The most commonly used discharge criteria were clinical factors, organisational discharge issues and patient-related factors. A total of 269 patients returned their questionnaires. About one third of the adult patients and nearly half of the children (or their parents) felt their personal situation and assistance needed at home was insufficiently taken into account before discharge. Patients were least satisfied with the information given about what they were allowed to do or should avoid after discharge and their involvement in the planning of their discharge. Thus, besides obvious medical reasons for discharge, several non-medical reasons were signalled by all stakeholders as important issues to be improved. Conclusions A set of discharge criteria could be defined that is useful for a more uniform hospital discharge policy that may help reduce unnecessary length of stay and improve patient satisfaction. PMID:24625666

Searching hospital discharge records for snow sport injury: no easy run?

PubMed

Smartt, Pamela F M; Chalmers, David J

2012-01-01

When using hospital discharge data to shape sports injury prevention policy, it is important to correctly identify cases. The objectives of this study were to examine the ease with which snow-skiing and snowboarding injury cases could be identified from national hospital discharge data and to assess the suitability of the information obtained for shaping policy. Hospital discharges for 2000-2004 were linked to compensated claims and searched sequentially using coded and narrative information. One thousand three hundred seventy-six eligible cases were identified, with 717 classified as snowboarding and 659 as snow-skiing. For the most part, cases could not be identified and distinguished using simple searches of coded data; keyword searches of narratives played a key role in case identification but not in describing the mechanism of injury. Identification and characterisation of snow sport injury from in-patient discharge records is problematic due to inadequacies in the coding systems and/or their implementation. Narrative reporting could be improved.

Positive direct current corona discharges in single wire-duct electrostatic precipitators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yehia, Ashraf, E-mail: yehia30161@yahoo.com; Department of Physics, Faculty of Science, Assiut University, Assiut 71516, Arab Republic of Egypt; Abdel-Fattah, E.

This paper is aimed to study the characteristics of the positive dc corona discharges in single wire-duct electrostatic precipitators. Therefore, the corona discharges were formed inside dry air fed single wire-duct reactor under positive dc voltage at the normal atmospheric conditions. The corona current-voltage characteristics curves have been measured in parallel with the ozone concentration generated inside the reactor under different discharge conditions. The corona current-voltage characteristics curves have agreed with a semi empirical equation derived from the previous studies. The experimental results of the ozone concentration generated inside the reactor were formulated in the form of an empirical equationmore » included the different parameters that were studied experimentally. The obtained equations are valid to expect both the current-voltage characteristics curves and the corresponding ozone concentration that generates with the positive dc corona discharges inside single wire-duct electrostatic precipitators under any operating conditions in the same range of the present study.« less

Determination of channel-morphology characteristics, bankfull discharge, and various design-peak discharges in western Montana

USGS Publications Warehouse

Lawlor, Sean M.

2004-01-01

Stream-restoration projects using natural stream designs typically are based on channel configurations that can accommodate a wide range of streamflow and sediment-transport conditions without excessive erosion or deposition. Bankfull discharge is an index of streamflow considered to be closely related to channel shape, size, and slope (channel morphology). Because of the need for more information about the relation between channel morphology and bankfull discharge, the U.S. Geological Survey (USGS), in cooperation with the Montana Department of Transportation and the U.S. Department of Agriculture-Lolo National Forest, conducted a study to collect channel-morphology and bankfull-discharge data at gaged sites and use these data to improve current (2004) methods of estimation of bankfull discharge and various design-peak discharges at ungaged sites. This report presents channel-morphology characteristics, bankfull discharge, and various design-peak discharges for 41 sites in western Montana. Channel shape, size, and slope and bankfull discharge were determined at 41 active or discontinued USGS streamflow-gaging sites in western Montana. The recurrence interval for the bankfull discharge for this study ranged from 1.0 to 4.4 years with a median value of 1.5 years. The relations between channel-morphology characteristics and various design-peak discharges were examined using regression analysis. The analyses showed that the only characteristics that were significant for all peak discharges were either bankfull width or bankfull cross-sectional area. Bankfull discharge at ungaged sites in most of the study area can be estimated by application of a multiplier after determining the 2-year peak discharge at the ungaged site. The multiplier, which is the ratio of bankfull discharge to the 2-year peak discharge determined at the 41 sites, ranged from 0.21 to 3.7 with a median value of 0.84. Regression relations between bankfull discharge and drainage area and between

The Electrostatic Environments of Mars: Atmospheric Discharges

NASA Technical Reports Server (NTRS)

Calle, Carlos I.; Mackey, Paul J.; Johansen, Michael R.; Hogue, Michael D.; Phillips, James, III; Cox, Rachel E.

2016-01-01

The electrostatic environment on Mars is controlled by its ever present atmospheric dust. Dust devils and dust storms tribocharge this dust. Theoretical studies predict that lightning and/or glow discharges should be present on Mars, but none have been directly observed. Experiments are planned to shed light on this issue.

Nonlinear behavior in high-intensity discharge lamps

NASA Astrophysics Data System (ADS)

Baumann, Bernd; Schwieger, Joerg; Wolff, Marcus; Manders, Freddy; Suijker, Jos

2016-06-01

The light flicker problem of high intensity discharge lamps is studied numerically and experimentally. It is shown that in some respects the systems behave very similar to the forced Duffing oscillator with a softening spring. In particular, the jump phenomenon and hysteresis are observed in the simulations and in the experiments.

Implementation of Discharge Plans for Chronically Ill Elders Discharged Home.

ERIC Educational Resources Information Center

Proctor, Enola K.; And Others

1996-01-01

Addresses the extent to which discharge plans for elderly patients with congestive heart failure were implemented as planned, tested the consequences of implementation problems, and identified factors associated with implementation problems. Implications for hospital discharge planners and home health care are discussed. (KW)

A Corona Discharge Initiated Electrochemical Electrospray Ionization Technique

PubMed Central

Lloyd, John R.; Hess, Sonja

2009-01-01

We report here the development of a corona discharge (CD) initiated electrochemical (EC) electrospray ionization (ESI) technique using a standard electrospray ion source. This is a new ionization technique distinct from ESI, electrochemistry inherent to ESI, APCI, and techniques using hydroxyl radicals produced under atmospheric pressure conditions. By maximizing the observable CD at the tip of a stainless steel ESI capillary, efficient electrochemical oxidation of electrochemically active compounds is observed. For electrochemical oxidation to be observed, the ionization potential of the analyte must be lower than Fe. Ferrocene labeled compounds were chosen as the electrochemically active moiety. The electrochemical cell in the ESI source was robust and generated ions with selectivity according to the ionization potential of the analytes and up to zeptomolar sensitivity. Our results indicate that CD initiated electrochemical ionization has the potential to become a powerful technique to increase the dynamic range, sensitivity and selectivity of ESI experiments. Synopsis Using a standard ESI source a corona discharge initiated electrochemical ionization technique was established resulting from the electrochemistry occurring at the CD electrode surface. PMID:19747843

Predicting Time to Hospital Discharge for Extremely Preterm Infants

PubMed Central

Hintz, Susan R.; Bann, Carla M.; Ambalavanan, Namasivayam; Cotten, C. Michael; Das, Abhik; Higgins, Rosemary D.

2010-01-01

As extremely preterm infant mortality rates have decreased, concerns regarding resource utilization have intensified. Accurate models to predict time to hospital discharge could aid in resource planning, family counseling, and perhaps stimulate quality improvement initiatives. Objectives For infants <27 weeks estimated gestational age (EGA), to develop, validate and compare several models to predict time to hospital discharge based on time-dependent covariates, and based on the presence of 5 key risk factors as predictors. Patients and Methods This was a retrospective analysis of infants <27 weeks EGA, born 7/2002-12/2005 and surviving to discharge from a NICHD Neonatal Research Network site. Time to discharge was modeled as continuous (postmenstrual age at discharge, PMAD), and categorical variables (“Early” and “Late” discharge). Three linear and logistic regression models with time-dependent covariate inclusion were developed (perinatal factors only, perinatal+early neonatal factors, perinatal+early+later factors). Models for Early and Late discharge using the cumulative presence of 5 key risk factors as predictors were also evaluated. Predictive capabilities were compared using coefficient of determination (R2) for linear models, and AUC of ROC curve for logistic models. Results Data from 2254 infants were included. Prediction of PMAD was poor, with only 38% of variation explained by linear models. However, models incorporating later clinical characteristics were more accurate in predicting “Early” or “Late” discharge (full models: AUC 0.76-0.83 vs. perinatal factor models: AUC 0.56-0.69). In simplified key risk factors models, predicted probabilities for Early and Late discharge compared favorably with observed rates. Furthermore, the AUC (0.75-0.77) were similar to those of models including the full factor set. Conclusions Prediction of Early or Late discharge is poor if only perinatal factors are considered, but improves substantially with

Studies on pulsed optogalvanic effect in Eu/Ne hollow cathode discharge.

PubMed

Saini, V K; Kumar, P; Dixit, S K; Nakhe, S V

2014-07-01

The optogalvanic (OG) effect has been observed in a Eu/Ne hollow cathode discharge lamp using pulsed laser irradiation. An OG spectrum is recorded in dye laser wavelength region 574–602 nm using a boxcar-averager. In total 41 atomic lines are observed. Of these, 38 lines are assigned to neon transitions. Two lines observed corresponding to wavelengths 576.519 and 601.815 nm are assigned to europium transitions; (4f 7 6s 2 , S 8 7/2 →4f 7 6s6p , zP 6 7/2 ) and (4f 7 6s 2 , S 8 7/2 →4f 7 6s6p , zP 8 9/2 ), respectively, and the remaining line at 582.475 nm could not be assigned. The effect of the discharge current on europium as well as neon OG signals is also studied. At moderate discharge current values, an extra positive peak is observed in neon OG signal for the transition (1s 5 →2p 2 ) at 588.189 nm, which is explained by Penning-ionization process using the quasi-resonant energy transfer interactions between excited neon and europium atoms lying in 2p 2 and D 10 9/2 states, respectively.

Pending laboratory tests and the hospital discharge summary in patients discharged to sub-acute care.

PubMed

Walz, Stacy E; Smith, Maureen; Cox, Elizabeth; Sattin, Justin; Kind, Amy J H

2011-04-01

Previous studies have noted a high (41%) prevalence and poor discharge summary communication of pending laboratory (lab) tests at the time of hospital discharge for general medical patients. However, the prevalence and communication of pending labs within a high-risk population, specifically those patients discharged to sub-acute care (i.e., skilled nursing, rehabilitation, long-term care), remains unknown. To determine the prevalence and nature of lab tests pending at hospital discharge and their inclusion within hospital discharge summaries, for common sub-acute care populations. Retrospective cohort study. Stroke, hip fracture, and cancer patients discharged from a single large academic medical center to sub-acute care, 2003-2005 (N = 564) Pending lab tests were abstracted from the laboratory information system (LIS) and from each patient's discharge summary, then grouped into 14 categories and compared. Microbiology tests were sub-divided by culture type and number of days pending prior to discharge. Of sub-acute care patients, 32% (181/564) were discharged with pending lab tests per the LIS; however, only 11% (20/181) of discharge summaries documented these. Patients most often left the hospital with pending microbiology tests (83% [150/181]), particularly blood and urine cultures, and reference lab tests (17% [30/181]). However, 82% (61/74) of patients' pending urine cultures did not have 24-hour preliminary results, and 19% (13/70) of patients' pending blood cultures did not have 48-hour preliminary results available at the time of hospital discharge. Approximately one-third of the sub-acute care patients in this study had labs pending at discharge, but few were documented within hospital discharge summaries. Even after considering the availability of preliminary microbiology results, these omissions remain common. Future studies should focus on improving the communication of pending lab tests at discharge and evaluating the impact that this improved

An experimental study of the role of subsurface plumbing on geothermal discharge

USGS Publications Warehouse

Namiki, Atsuko; Ueno, Yoshinori; Hurwitz, Shaul; Manga, Michael; Munoz-Saez, Carolina; Murphy, Fred

2016-01-01

In order to better understand the diverse discharge styles and eruption intervals observed at geothermal features, we performed three series of laboratory experiments with differing plumbing geometries. A single, straight conduit that connects a hot water bath (flask) to a vent (funnel) can originate geyser-like periodic eruptions, continuous discharge like a boiling spring, and fumarole-like steam discharge, depending on the conduit length and radius. The balance between the heat loss from the conduit walls and the heat supplied from the bottom determines whether and where water can condense which in turn controls discharge style. Next, we connected the conduit to a cold water reservoir through a branch, simulating the inflow from an external water source. Colder water located at a higher elevation than a branching point can flow into the conduit to stop the boiling in the flask, controlling the periodicity of the eruption. When an additional branch is connected to a second cold water reservoir, the two cold reservoirs can interact. Our experiments show that branching allows new processes to occur, such as recharge of colder water and escape of steam from side channels, leading to greater variation in discharge styles and eruption intervals. This model is consistent with the fact that eruption duration is not controlled by emptying reservoirs. We show how differences in plumbing geometries can explain various discharge styles and eruption intervals observed in El Tatio, Chile, and Yellowstone, USA.

Payment source and length of use among home health agency discharges.

PubMed

Han, Beth; Remsburg, Robin E; Lubitz, James; Goulding, Margie

2004-11-01

Our study compared (1) length of use among home health care (HHC) discharges with Medicare, Medicaid, or private health insurance between 1991 and 2000 and (2) factors associated with length of HHC use among discharges with Medicare, Medicaid, or private health insurance. Data were obtained from the 1992, 1994, 1996, 1998, and 2000 National Home and Hospice Care Surveys (n = 18,416). Logistic regressions and stratified analyses by primary payment source were applied. After adjusting for covariates, Medicare HHC patients were from 0.52 to 0.75 times less likely to be discharged within 30 days in 1991-1996 than in 1997-1998. Medicaid patients were 0.37 times less likely to be discharged within 30 days in 1991-1992 than in 1997-1998. Patients with private insurance were 2.05 times more likely to be discharged within 30 days in 1993-1994 than in 1997-1998. No significant difference in length of use was found at the multivariate level between 1997-1998 and 1999-2000 among HHC patients with Medicare, Medicaid, or private health insurance. Results for being discharged within 60 days were similar to these described above. Our study shows that length of HHC use among Medicare discharges decreased after the implementation of the Medicare interim payment system. We did not find a spillover effect of the Medicare interim payment system on length of HHC use among discharges with Medicaid or private health insurance. Our results can help health professionals and policy makers better understand the dynamic associations between payment systems and length of use of HHC services.

RF assisted Glow Discharge Condition experiment for SST-1 Tokamak

NASA Astrophysics Data System (ADS)

Raval, Dilip; Khan, Ziauddin; George, Siju; Dhanani, Kalpeshkumar R.; Paravastu, Yuvakiran; Semwal, Pratibha; Thankey, Prashant; Shoaib Khan, Mohammad; Kakati, Bharat; Pradhan, Subrata

2017-04-01

Impurity control reduces the radiation loss from plasma and hence enhances the plasma operation. Oxygen and water vapors are the most common impurities in tokamak devices. Water vapour can be reduced with extensive baking while in order to have a significant reduction in oxygen it is necessary to use glow discharge condition (GDC). RF assisted glow discharge cleaning system will be implemented to remove low z impurities at PFC installed SST-1 vacuum vessel. A RF assisted Glow discharge conditioning is studied at laboratory to find the optimum operating parameters in a view to implement at SST-1 tokamak. Helium is used as a fuel gas in the present experiment. It is observed that the ultimate impurity level is reduced significantly below to the accepted level for plasma operation after RF assisted GDC. The experimental findings of RF assisted Glow discharge conditioning is discussed in details in this paper.

Pulsed Gas Lasers Pumped by a Runaway Electron Initiated Discharge

NASA Astrophysics Data System (ADS)

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

2017-12-01

The generation parameters are investigated in a runaway electron preionized diffuse discharge (REP DD). Laser generation is produced in different spectral bands from the IR to VUV range. New modes of the nitrogen laser operation are obtained. Ultimate efficiencies of N2- and nonchain HF(DF)-lasers are achieved. A possibility of increasing the pulse durations of XeF-, KrF-, ArF- and VUV F2- lasers (157 nm) in an oscillating REP DD is shown. The efficiencies of VUV- and UV-generation comparable with that of a laser pumped by a self-sustained volume discharge with preionization are gained.

Bone marrow transplant – children - discharge

MedlinePlus

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

Discharge Characterization of 40 cm-Microwave ECR Ion Source and Neutralizer

NASA Technical Reports Server (NTRS)

Foster, John E.; Patterson, Michael J.; Britton, Melissa

2003-01-01

Discharge characteristics of a 40 cm, 2.45 GHz Electron Cyclotron Resonance (ECR) ion thruster discharge chamber and neutralizer were acquired. Thruster bulk discharge plasma characteristics were assessed using a single Langmuir probe. Total extractable ion current was measured as a function of input microwave power and flow rate. Additionally, radial ion current density profiles at the thruster.s exit plane were characterized using five equally spaced Faraday probes. Distinct low and high density operating modes were observed as discharge input power was varied from 0 to 200 W. In the high mode, extractable ion currents as high as 0.82 A were measured. Neutralizer emission current was characterized as a function of flow rate and microwave power. Neutralizer extraction currents as high as 0.6 A were measured.

Some Results from Studies of Microwave Discharges in Liquid Heavy Hydrocarbons

NASA Astrophysics Data System (ADS)

Averin, K. A.; Lebedev, Yu. A.; Shakhatov, V. A.

2018-01-01

Some results from studies of microwave discharges in heavy hydrocarbons are presented. Microwave energy was introduced into liquid hydrocarbon via a coaxial line. The pressure above the liquid surface was equal to the atmospheric pressure. The discharge was ignited in a mixture of argon and hydrocarbon vapor. Argon was supplied through a channel in the central conductor of the coaxial line. The emission spectra of discharges in different liquid hydrocarbons were studied. It is shown that the emission spectra mainly consist of sequences of Swan bands, while radiation of other plasma components is on the noise level. Spectra of plasma emission are presented for discharges in liquid n-heptane, nefras, and C-9 oil used to produce chemical fibers. The rotational (gas) and vibrational temperatures are determined by processing the observed spectra.

Modeling of microwave-sustained plasmas at atmospheric pressure with application to discharge contraction.

PubMed

Castaños Martinez, E; Kabouzi, Y; Makasheva, K; Moisan, M

2004-12-01

The modeling of microwave-sustained discharges at atmospheric pressure is much less advanced than at reduced pressure (<10 Torr) because of the greater complexity of the mechanisms involved. In particular, discharge contraction, a characteristic feature of high-pressure discharges, is not well understood. To describe adequately this phenomenon, one needs to consider that the charged-particle balance in atmospheric-pressure discharges relies on the kinetics of molecular ions, including their dissociation through electron impact. Nonuniform gas heating plays a key role in the radial distribution of the density of molecular ions. The onset of contraction is shown to depend only on radially nonuniform gas heating. The radial nonuniformity of the electric field intensity also plays an important role allowing one, for instance, to explain the lower degree of contraction observed in microwave discharges compared to dc discharges. We present a numerical fluid-plasma model that aims to bring into relief the main features of discharge contraction in rare gases. It calls for surface-wave discharges because of their wide range of operating conditions, enabling a closer check between theory and experiment.

Tracking Vessels to Illegal Pollutant Discharges Using Multisource Vessel Information

NASA Astrophysics Data System (ADS)

Busler, J.; Wehn, H.; Woodhouse, L.

2015-04-01

Illegal discharge of bilge waters is a significant source of oil and other environmental pollutants in Canadian and international waters. Imaging satellites are commonly used to monitor large areas to detect oily discharges from vessels, off-shore platforms and other sources. While remotely sensed imagery provides a snap-shot picture useful for detecting a spill or the presence of vessels in the vicinity, it is difficult to directly associate a vessel to an observed spill unless the vessel is observed while the discharge is occurring. The situation then becomes more challenging with increased vessel traffic as multiple vessels may be associated with a spill event. By combining multiple sources of vessel location data, such as Automated Information Systems (AIS), Long Range Identification and Tracking (LRIT) and SAR-based ship detection, with spill detections and drift models we have created a system that associates detected spill events with vessels in the area using a probabilistic model that intersects vessel tracks and spill drift trajectories in both time and space. Working with the Canadian Space Agency and the Canadian Ice Service's Integrated Satellite Tracking of Pollution (ISTOP) program, we use spills observed in Canadian waters to demonstrate the investigative value of augmenting spill detections with temporally sequenced vessel and spill tracking information.

Magnitude of Anemia at Discharge Increases 30-Day Hospital Readmissions.

PubMed

Koch, Colleen G; Li, Liang; Sun, Zhiyuan; Hixson, Eric D; Tang, Anne; Chagin, Kevin; Kattan, Michael; Phillips, Shannon C; Blackstone, Eugene H; Henderson, J Michael

2017-12-01

Anemia during hospitalization is associated with poor health outcomes. Does anemia at discharge place patients at risk for hospital readmission within 30 days of discharge? Our objectives were to examine the prevalence and magnitude of anemia at hospital discharge and determine whether anemia at discharge was associated with 30-day readmissions among a cohort of hospitalizations in a single health care system. From January 1, 2009, to August 31, 2011, there were 152,757 eligible hospitalizations within a single health care system. The endpoint was any hospitalization within 30 days of discharge. The University HealthSystem Consortium's clinical database was used for demographics and comorbidities; hemoglobin values are from the hospitals' electronic medical records, and readmission status was obtained from the University HealthSystem Consortium administrative data systems. Mild anemia was defined as hemoglobin of greater than 11 to less than 12 g/dl in women and greater than 11 to less than 13 g/dl in men; moderate, greater than 9 to less than or equal to 11 g/dl; and severe, less than or equal to 9 g/dl. Logistic regression was used to assess the association of anemia and 30-day readmissions adjusted for demographics, comorbidity, and hospitalization type. Among 152,757 hospitalizations, 72% of patients were discharged with anemia: 31,903 (21%), mild; 52,971 (35%), moderate; and 25,522 (17%), severe. Discharge anemia was associated with severity-dependent increased odds for 30-day hospital readmission compared with those without anemia: for mild anemia, 1.74 (1.65-1.82); moderate anemia, 2.76 (2.64-2.89); and severe anemia, 3.47 (3.30-3.65), P < 0.001. Anemia at discharge is associated with a severity-dependent increased risk for 30-day readmission. A strategy focusing on anemia treatment care paths during index hospitalization offers an opportunity to influence subsequent readmissions.

Parameters of thunderstorm activity and lightning discharges in Central Yakutia from 2009 to 2012