Sample records for zero power critical experiment minerve

  1. The CAPTAIN-MINERvA Experiment

    NASA Astrophysics Data System (ADS)

    Yoo, Jieun; -Minerva Collaboration, Captain

    2016-03-01

    The CAPTAIN-MINERvA experiment aims to measure neutrino-argon interactions in the few GeV energy range, which corresponds to the first oscillation maximum for DUNE. It uses the CAPTAIN LArTPC as an active target in conjunction with MINERvA to measure the neutrino interactions and will provide the only high-statistics measurement of the neutrino-argon cross section above 2 GeV before DUNE. CAPTAIN is a liquid argon TPC which is currently being built at LANL. It will be moved to Fermilab and be used in conjunction with MINERvA. Using MINERvA as the tracking detector will allow us to measure the muon energy by dE/dx and thus more completely measure the incoming neutrino energy. And, by measuring the ratio of cross sections in argon to hydrocarbon in the scintillator, we will be able to make stringent tests of nuclear effect models. Thus, through this unique combination of detectors, CAPTAIN-MINERvA will be able to study neutrino-argon interactions and serve as an important source of input for DUNE.

  2. The MINERvA Experiment

    NASA Astrophysics Data System (ADS)

    Betancourt, Minerba; Minerva Collaboration

    2017-01-01

    MINERvA is a neutrino scattering experiment to make precision measurements of cross sections and investigate nuclear effects. A precise understanding of neutrino interactions is crucial for the neutrino oscillation program. Several cross sections will be presented, including pion production, kaon production as well as direct comparisons of the same process on different nuclei. Comparisons with theoretical models are reported.

  3. Kinetic Parameter Measurements in the MINERVE Reactor

    NASA Astrophysics Data System (ADS)

    Perret, Grégory; Geslot, Benoit; Gruel, Adrien; Blaise, Patrick; Di-Salvo, Jacques; De Izarra, Grégoire; Jammes, Christian; Hursin, Mathieu; Pautz, Andréas

    2017-01-01

    In the framework of an international collaboration, teams of the PSI and CEA research institutes measure the critical decay constant (α0 = β/A), delayed neutron fraction (β) and generation time (A) of the Minerve reactor using the Feynman-α, Power Spectral Density and Rossi-α neutron noise measurement techniques. These measurements contribute to the experimental database of kinetic parameters used to improve nuclear data files and validate modern methods in Monte Carlo codes. Minerve is a zero-power pool reactor composed of a central experimental test lattice surrounded by a large aluminum buffer and four high-enriched driver regions. Measurements are performed in three slightly subcritical configurations (-2 cents to -30 cents) using two high-efficiency 235U fission chambers in the driver regions. Measurement of α0 and β obtained by the two institutes and with the different techniques are consistent for the configurations envisaged. Slight increases of the β values are observed with the subcriticality level. Best estimate values are obtained with the Cross-Power Spectral Density technique at -2 cents, and are worth: β = 716.9±9.0 pcm, α0 = 79.0±0.6 s-1 and A = 90.7±1.4 μs. The kinetic parameters are predicted with MCNP5-v1.6 and TRIPOLI4.9 and the JEFF-3.1/3.1.1 and ENDF/B-VII.1 nuclear data libraries. The predictions for β and α0 overestimate the experimental results by 3-5% and 10-12%, respectively; that for A underestimate the experimental result by 6-7%. The discrepancies are suspected to come from the driven system nature of Minerve and the location of the detectors in the driver regions, which prevent accounting for the full reactor.

  4. Multianode Photomultiplier Tube Alignment for the MINERvA Experiment at Fermilab

    NASA Astrophysics Data System (ADS)

    Bruno, Jorge

    2006-10-01

    The MINERvA experiment (Main INjector ExpeRiment vA) at FNAL will study the neutrino-nucleon and neutrino-nucleus interaction. The light collection from the detector will be done via optic fibers using Hamamatsu H8804 64-channel photomultiplier tubes (PMT). Each PMT channel needs to be precisely aligned with the corresponding optic fiber. The MINERvA PMT optical boxes contain precision machined optic ``cookies'' which capture the 8x8 array of optic fibers. Each PMT-cookie pair needs to be aligned as precisely as possible. This contribution will describe the alignment setup and procedure implemented at James Madison University.

  5. Pile noise experiment in MINERVE reactor to estimate kinetic parameters using various data processing methods

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

    Geslot, Benoit; Gruel, Adrien; Pepino, Alexandra

    2015-07-01

    MINERVE is a two-zone pool type zero power reactor operated by CEA (Cadarache, France). Kinetic parameters of the core (prompt neutron decay constant, delayed neutron fraction, generation time) have been recently measured using various pile noise experimental techniques, namely Feynman-α, Rossi-α and Cohn-α. Results are discussed and compared to each other's. The measurement campaign has been conducted in the framework of a tri-partite collaboration between CEA, SCK.CEN and PSI. Results presented in this paper were obtained thanks to a time-stamping acquisition system developed by CEA. PSI performed simultaneous measurements which are presented in a companion paper. Signals come from twomore » high efficiency fission chambers located in the graphite reflector next to the core driver zone. Experiments were conducted at critical state with a reactor power of 0.2 W. The core integral fission rate is obtained from a calibrated miniature fission chamber located at the center of the core. Other results obtained in two sub-critical configurations will be presented elsewhere. Best estimate delayed neutron fraction comes from the Cohn-α method: 747 ± 15 pcm (1σ). In this case, the prompt decay constant is 79 ± 0.5 s{sup -1} and the generation time is 94.5 ± 0.7 μs. Other methods give consistent results within the confidence intervals. Experimental results are compared to calculated values obtained from a full 3D core modeling with the CEA-developed Monte Carlo code TRIPOLI4.9 associated with its continuous energy JEFF3.1.1-based library. A very good agreement is observed for the calculated delayed neutron fraction (748.7 ± 0.4 pcm at 1σ), that is a difference of -0.3% with the experiment. On the contrary, a 10% discrepancy is observed for the calculated generation time (104.4 ± 0.1 μs at 1σ). (authors)« less

  6. MINERvA’s flux prediction

    DOE PAGES

    Golan, Tomasz; Aliaga, Leonidas; Kordosky, Mike

    2016-12-12

    Here, the MINERvA (Main INjector ExpeRiment: νA) experiment is focused on the measurement of neutrino cross sections on various nuclear targets. For this kind of study it is crucial to know precisely neutrino flux. MINERvA uses the NuMI (Neutrinos at the Main Injector) beam produced at Fermilab. The recent study on the evaluation of the beam and its uncertainty is presented. The NuMI beam is also used by other neutrino experiment, like MINOS, ArgoNeuT, PEANUT, and NOvA, therefore, the results can be used by other collaborations.

  7. MINERvA CCInclusive Analysis

    NASA Astrophysics Data System (ADS)

    Martinez, David

    2013-04-01

    MINERvA is a few-GeV neutrino scattering experiment that has been taking data in the NuMI beam line at Fermilab since November 2009. The experiment will provide important inputs, both in support of neutrino oscillation searches and as a pure weak probe of the nuclear medium. For this, MINERvA employs a fine-grained detector, with an eight ton active target region composed of plastic scintillator and a suite of nuclear targets composed of helium, carbon, iron, lead and water placed upstream of the active region. In this talk, we present the current status of the charged current inclusive analysis for neutrinos and antineutrinos in plastic scintillator.

  8. Tests of the Hardware and Software for the Reconstruction of Trajectories in the Experiment MINERvA (in Portuguese)

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

    Palomino Gallo, Jose Luis; /Rio de Janeiro, CBPF

    MINERvA experiment has a highly segmented and high precision neutrino detector able to record events with high statistic (over 13 millions in a four year run). MINERvA uses FERMILAB NuMI beamline. The detector will allow a detailed study of neutrino-nucleon interactions. Moreover, the detector has a target with different materials allowing, for the first time, the study of nuclear effects in neutrino interactions. We present here the work done with the MINERvA reconstruction group that has resulted in: (a) development of new codes to be added to the RecPack package so it can be adapted to the MINERvA detector structure;more » (b) finding optimum values for two of the MegaTracker reconstruction package variables: PEcut = 4 (minimum number of photo electrons for a signal to be accepted) and Chi2Cut = 200 (maximum value of {chi}{sup 2} for a track to be accepted); (c) testing of the multi anode photomultiplier tubes used at MINERvA in order to determine the correlation between different channels and for checking the device's dark counts.« less

  9. NuMI Flux Predictions for NOvA and MINERvA

    NASA Astrophysics Data System (ADS)

    Aliaga Soplin, Leonidas; Nova Collaboration; Minerva Collaboration

    2017-01-01

    The determination of the neutrino flux in any conventional neutrino beam presents a challenge for the current and future short and long baseline neutrino experiments. The uncertainties associated with the production and attenuation of the hadrons in the beamline materials along with those associated with the beam optics have a big effect in the knowledge of the flux. For experiments like MINERvA and NOvA, understanding the flux is crucial since it enters directly into every neutrino-nucleus cross-section measurement. The majority of this work involves predicting the neutrino flux using dedicated hadron production measurements from hadron-nucleus collisions. The predictions at the MINERvA and NOvA near detectors are presented as well as the results of incorporating in-situ MINERvA data that can provide additional constraints. These results have been fully implemented in MINERvA and they are currently use for its cross-section analysis. The implementation for NoVA is underway. The procedure and conclusions of this work will have a big impact on future hadron production experiments and on determining the flux for the upcoming DUNE experiment.

  10. Neutrino Exclusive Charged Current Quasi-Elastic Scattering in MINERvA

    NASA Astrophysics Data System (ADS)

    Walton, Tammy

    2012-03-01

    The MINERvA experiment will measure neutrino and antineutrino quasi-elastic scattering on helium, water, carbon, iron, and lead for neutrinos in the few GeV range. We will present an overview of MINERvA analysis plan for neutrino exclusive charged current quasi-elastic scattering on lead, iron, and carbon.

  11. Neutrino-Nucleon Deep Inelastic Scattering in MINERvA

    NASA Astrophysics Data System (ADS)

    Norrick, Anne; Minerva Collaboration

    2015-04-01

    Neutrino-Nucleon Deep Inelastic Scattering (DIS) events provide a probe into the structure of the nucleus that cannot be accessed via charged lepton-nucleon interactions. The MINERvA experiment is stationed in the Neutrinos from the Main Injector (NuMI) beam line at Fermi National Accelerator Laboratory. The projected sensitivity of nuclear structure function analyses using MINERvA's suite of nuclear targets (C, CH, Fe and Pb) in the upgraded 6 GeV neutrino energy NuMI beam will be explored, and their impact discussed.

  12. Re-interpretation of the ERMINE-V experiment validation of fission product integral cross section in the fast energy range

    NASA Astrophysics Data System (ADS)

    Ros, Paul; Leconte, Pierre; Blaise, Patrick; Naymeh, Laurent

    2017-09-01

    The current knowledge of nuclear data in the fast neutron energy range is not as good as in the thermal range, resulting in larger propagated uncertainties in integral quantities such as critical masses or reactivity effects. This situation makes it difficult to get the full benefit from recent advances in modeling and simulation. Zero power facilities such as the French ZPR MINERVE have already demonstrated that they can contribute to significantly reduce those uncertainties thanks to dedicated experiments. Historically, MINERVE has been mainly dedicated to thermal spectrum studies. However, experiments involving fast-thermal coupled cores were also performed in MINERVE as part of the ERMINE program, in order to improve nuclear data in fast spectra for the two French SFRs: PHENIX and SUPERPHENIX. Some of those experiments have been recently revisited. In particular, a full characterization of ZONA-1 and ZONA-3, two different cores loaded in the ERMINE V campaign, has been done, with much attention paid to possible sources of errors. It includes detailed geometric descriptions, energy profiles of the direct and adjoint fluxes and spectral indices obtained thanks to Monte Carlo calculations and compared to a reference fast core configuration. Sample oscillation experiments of separated fission products such as 103Rh or 99Tc, which were part of the ERMINE V program, have been simulated using recently-developed options in the TRIPOLI-4 code and compared to the experimental values. The present paper describes the corresponding results. The findings motivate in-depth studies for designing optimized coupled-core conditions in ZEPHYR, a new ZPR which will replace MINERVE and will provide integral data to meet the needs of Gen-III and Gen-IV reactors.

  13. Recent Results from MINERvA

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

    Fields, Laura

    2016-12-21

    The MINERvA collaboration is currently engaged in a broad program of neutrino-nucleus interaction measurements. Several recent measurements of interest to the accelerator-based oscillation community are presented. These include measurements of quasi-elastic scattering, diffractive pion production, kaon production and comparisons of interaction cross sections across nuclei. A new measurement of the NuMI neutrino beam flux that incorporates both external hadro-production data and MINERvA detector data is also presented.

  14. Exclusive Neutrino Charged Current Coherent Pion Production Cross Section Measurements in MINERvA

    NASA Astrophysics Data System (ADS)

    Higuera, A.

    2012-03-01

    MINERvA (Main Injector Experiment for v-A) is a neutrino scattering experiment in the 1-10 GeV energy range in the NuMI high-intensity neutrino beam at Fermi National Accelerator Laboratory. MINERvA is measuring neutrino/antineutrino scattering off a variety of different nuclear materials (C, Fe, Pb, He, H2O) and plans to measure the A-dependence of the Charged Current Coherent Pion Production cross section. We provide an outline of this measurement including the expected event rates and our methods for differentiating signal from background.

  15. Recent Results from MINERvA

    NASA Astrophysics Data System (ADS)

    Dytman, Steven

    2016-03-01

    Neutrino cross sections are important both as a key component of neutrino oscillation experiments and as a way to study the axial and vector response in nuclear systems. MINERvA is a neutrino cross section experiment that has been taking data at Fermilab since 2009. The beam energy is well-matched to existing oscillation experiments such as MINOS/MINOS + and NOvA and planned experiments such as DUNE. The experiment has the unique capability to measure cross sections simultaneously with hydrocarbon, iron, and lead targets. Numerous publications have provided new data for neutrino and antineutrino interactions in these targets including quasielastic, pion production, and inclusive processes. This talk will present a series of recent measurements, their relationship to oscillation experiments and to nuclear physics.

  16. Recent Results From MINERvA

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

    Patrick, Cheryl

    The MINERvA detector is situated in Fermilab's NuMI beam, which provides neutrinos and antineutrinos in the 1-20 GeV range. It is designed to make precision cross-section measurements for scattering processes on various nuclei. These proceedings summarize the differential cross-section distributions measured for several different processes. Comparison of these with various models hints at additional nuclear effects not included in common simulations. These results will help constrain generators' nuclear models and reduce systematic uncertainties on their predictions. An accurate cross-section model, with minimal uncertainties, is vital to oscillation experiments.

  17. Americium-241 integral radiative capture cross section in over-moderated neutron spectrum from pile oscillator measurements in the Minerve reactor

    NASA Astrophysics Data System (ADS)

    Geslot, Benoit; Gruel, Adrien; Ros, Paul; Blaise, Patrick; Leconte, Pierre; Noguere, Gilles; Mathieu, Ludovic; Villamarin, David; Becares, Vicente; Plompen, Arjan; Kopecky, Stefan; Schillebeeckx, Peter

    2017-09-01

    An experimental program, called AMSTRAMGRAM, was recently conducted in the Minerve low power reactor operated by CEA Cadarache within the frame of the CHANDA initiative (Solving CHAllenges in Nuclear Data). Its aim was to measure the integral capture cross section of 241Am in the thermal domain. Motivation of this work is driven by large differences in this actinide thermal point reported by major nuclear data libraries. The AMSTRAMGRAM experiment, that made use of well characterized EC-JRC americium samples, was based on the oscillation technique commonly implemented in the Minerve reactor. First results are presented and discussed in this article. A preliminary calculation scheme was used to compare measured and calculated results. It is shown that this work confirms a bias previously observed with JEFF-3.1.1 (C/E-1 = -10.5 ± 2%). On the opposite, the experiment is in close agreement with 241Am thermal point reported in JEFF-3.2 (C/E-1 = 0.5 ± 2%).

  18. Muon neutrino CCQE at MINERvA

    DOE PAGES

    Betancourt, M.

    2016-12-13

    A precise understanding of quasi-elastic interactions is crucial to measure neutrino oscillations. The MINERvA experiment is currently working on different analyses of muon neutrino charged current quasi-elastic interactions. Here, we present updates to the previous quasi-elastic measurement, using a new flux, and we present the status of several analyses in progress; including double differential cross sections, a study of final state interactions using a sample with muon and a proton and the status of the CCQE analysis in the medium energy neutrino beam.

  19. MINERvA neutrino detector response measured with test beam data

    DOE PAGES

    Aliaga, L.; Altinok, O.; Araujo Del Castillo, C.; ...

    2015-04-11

    The MINERvA collaboration operated a scaled-down replica of thesolid scintillator tracking and sampling calorimeter regions of the MINERvA detector in a hadron test beam at the Fermilab Test Beam Facility. This paper reports measurements with samples of protons, pions, and electrons from 0.35 to 2.0 GeV/c momentum. The calorimetric response to protons, pions, and electrons is obtained from these data. A measurement of the parameter in Birks' law and an estimate of the tracking efficiency are extracted from the proton sample. Overall the data are well described by a Geant4-based Monte Carlo simulation of the detector and particle interactions withmore » agreements better than 4% for the calorimetric response, though some features of the data are not precisely modeled. Furthermore, these measurements are used to tune the MINERvA detector simulation and evaluate systematic uncertainties in support of the MINERvA neutrino cross-section measurement program.« less

  20. Zero Power Non-Contact Suspension System with Permanent Magnet Motion Feedback

    NASA Astrophysics Data System (ADS)

    Sun, Feng; Oka, Koichi

    This paper proposes a zero power control method for a permanent magnetic suspension system consisting mainly of a permanent magnet, an actuator, sensors, a suspended iron ball and a spring. A system using this zero power control method will consume quasi-zero power when the levitated object is suspended in an equilibrium state. To realize zero power control, a spring is installed in the magnetic suspension device to counterbalance the gravitational force on the actuator in the equilibrium position. In addition, an integral feedback loop in the controller affords zero actuator current when the device is in a balanced state. In this study, a model was set up for feasibility analysis, a prototype was manufactured for experimental confirmation, numerical simulations of zero power control with nonlinear attractive force were carried out based on the model, and experiments were completed to confirm the practicality of the prototype. The simulations and experiments were performed under varied conditions, such as without springs and without zero power control, with springs and without zero power control, with springs and with zero power control, using different springs and integral feedback gains. Some results are shown and analyzed in this paper. All results indicate that this zero power control method is feasible and effective for use in this suspension system with a permanent magnet motion feedback loop.

  1. Analysis and recent advances in gamma heating measurements in MINERVE facility by using TLD and OSLD techniques

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

    Amharrak, H.; Di Salvo, J.; Lyoussi, A.

    2011-07-01

    The objective of this study is to develop nuclear heating measurement methods in Zero Power experimental reactors. This paper presents the analysis of Thermo-Luminescent Detector (TLD) and Optically Stimulated Luminescent Detectors (OSLD) experiments in the UO{sub 2} core of the MINERVE research reactor at the CEA Cadarache. The experimental sources of uncertainties on the gamma dose have been reduced by improving the conditions, as well as the repeatability, of the calibration step for each individual TLD. The interpretation of these measurements needs to take into account calculation of cavity correction factors, related to calibration and irradiation configurations, as well asmore » neutron corrections calculations. These calculations are based on Monte Carlo simulations of neutron-gamma and gamma-electron transport coupled particles. TLD and OSLD are positioned inside aluminum pillboxes. The comparison between calculated and measured integral gamma-ray absorbed doses using TLD, shows that calculation slightly overestimates the measurement with a C/E value equal to 1.05 {+-} 5.3 % (k = 2). By using OSLD, the calculation slightly underestimates the measurement with a C/E value equal to 0.96 {+-} 7.0% (k = 2. (authors)« less

  2. Arachne - A web-based event viewer for MINERvA

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

    Tagg, N.; /Otterbein Coll.; Brangham, J.

    2011-11-01

    Neutrino interaction events in the MINERvA detector are visually represented with a web-based tool called Arachne. Data are retrieved from a central server via AJAX, and client-side JavaScript draws images into the user's browser window using the draft HTML 5 standard. These technologies allow neutrino interactions to be viewed by anyone with a web browser, allowing for easy hand-scanning of particle interactions. Arachne has been used in MINERvA to evaluate neutrino data in a prototype detector, to tune reconstruction algorithms, and for public outreach and education.

  3. Analysis of the nuclear dependence of the νμ charged current inclusive cross section with MINERvA

    NASA Astrophysics Data System (ADS)

    Ransome, Ronald

    2014-03-01

    Neutrino experiments use heavy nuclei (Fe, Pb, C) to achieve necessary statistics. However, the use of heavy nuclei exposes these experiments to the nuclear dependence of neutrino-nucleus cross sections, which are poorly known and difficult to model. The MINERvA (Main INjector ExpeRiment for ?-A), a few-GeV neutrino nucleus scattering experiment at Fermilab, seeks to remedy the situation by directly studying the A-dependence of exclusive and inclusive channels. The MINERvA detector contains an 8 ton fully active fine-grained scintillator tracking core and targets of carbon, iron, lead, water and liquid helium which sit upstream of the tracking core. We present results from our analysis using the nuclear targets: ratios of the ?? charged-current inclusive cross section in carbon, iron, lead and plastic scintillator (CH). Supported in part by the US National Science Foundation and the Dept. of Energy.

  4. Neutrino Charged Current Quasi-Elastic Analysis at MINERvA

    NASA Astrophysics Data System (ADS)

    Hurtado Anampa, Kenyi; Osta, Jyotsna

    2014-03-01

    MINERvA is a few GeV neutrino-nucleus scattering experiment designed to study low energy neutrino interactions both in support of neutrino oscillation experiments and as a pure weak probe of the nuclear medium. The experiment uses a fine-grained, high resolution detector. The active region is composed of plastic scintillator with additional targets of helium, carbon, iron, lead and water placed upstream of the active region. We present kinematic distributions from the double differential cross section analysis that aims to study quasi-elastic scattering of neutrinos in the active region as a function of the muon and proton observables. This analysis will use the low energy neutrino dataset recorded from November 2009 to April 2012.

  5. Criticality in the slowed-down boiling crisis at zero gravity.

    PubMed

    Charignon, T; Lloveras, P; Chatain, D; Truskinovsky, L; Vives, E; Beysens, D; Nikolayev, V S

    2015-05-01

    Boiling crisis is a transition between nucleate and film boiling. It occurs at a threshold value of the heat flux from the heater called CHF (critical heat flux). Usually, boiling crisis studies are hindered by the high CHF and short transition duration (below 1 ms). Here we report on experiments in hydrogen near its liquid-vapor critical point, in which the CHF is low and the dynamics slow enough to be resolved. As under such conditions the surface tension is very small, the experiments are carried out in the reduced gravity to preserve the conventional bubble geometry. Weightlessness is created artificially in two-phase hydrogen by compensating gravity with magnetic forces. We were able to reveal the fractal structure of the contour of the percolating cluster of the dry areas at the heater that precedes the boiling crisis. We provide a direct statistical analysis of dry spot areas that confirms the boiling crisis at zero gravity as a scale-free phenomenon. It was observed that, in agreement with theoretical predictions, saturated boiling CHF tends to zero (within the precision of our thermal control system) in zero gravity, which suggests that the boiling crisis may be observed at any heat flux provided the experiment lasts long enough.

  6. Zero-Power Radio Device.

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

    Brocato, Robert W.

    This report describes an unpowered radio receiver capable of detecting and responding to weak signals transmit ted from comparatively long distances . This radio receiver offers key advantages over a short range zero - power radio receiver previously described in SAND2004 - 4610, A Zero - Power Radio Receiver . The device described here can be fabricated as an integrated circuit for use in portable wireless devices, as a wake - up circuit, or a s a stand - alone receiver operating in conjunction with identification decoders or other electroni cs. It builds on key sub - components developed atmore » Sandia National Laboratories over many years. It uses surface acoustic wave (SAW) filter technology. It uses custom component design to enable the efficient use of small aperture antennas. This device uses a key component, the pyroelectric demodulator , covered by Sandia owned U.S. Patent 7397301, Pyroelectric Demodulating Detector [1] . This device is also described in Sandia owned U.S. Patent 97266446, Zero Power Receiver [2].« less

  7. Measurement of Neutrino and Antineutrino Charged-Current Inclusive Cross Sections with the MINERvA Detector

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

    Devan, Joshua D.

    2015-01-01

    Neutrinos are a nearly massless, neutral particle in the Standard Model that only interact via the weak interaction. Experimental confirmation of neutrino oscillations, in which a neutrino created as a particular type (electron, muon or tau) can be observed as a different type after propagating some distance, earned the 2015 Nobel Prize in Physics. Neutrino oscillation experiments rely on accurate measurements of neutrino interactions with matter, such as that presented here. Neutrinos also provide a unique probe of the nucleus, complementary to electron scattering experiments. This thesis presents a measurement of the charged-current inclusive cross section for muon neutrinos and antineutrinos in the energy range 2 to 50 GeV with the MINERvA detector. MINERvA is a neutrino scattering experiment in the NuMI neutrino beam at Fermilab, near Chicago. A cross section measures the probability of an interaction occurring, measured here as a function of neutrino energy. To extract a cross section from data, the observed rate of interactions is corrected for detector efficiency and divided by the number of scattering nucleons in the target and the flux of neutrinos in the beam. The neutrino flux is determined with the low-more » $$\

  8. Electron-neutrino charged-current quasi-elastic scattering in MINERvA

    NASA Astrophysics Data System (ADS)

    Wolcott, Jeremy

    2014-03-01

    The electron-neutrino charged-current quasi-elastic (CCQE) cross-section on nuclei is an important input parameter to appearance-type neutrino oscillation experiments. Current experiments typically work from the muon neutrino CCQE cross-section and apply corrections from theoretical arguments to obtain a prediction for the electron neutrino CCQE cross-section, but to date there has been no precise experimental verification of these estimates at an energy scale appropriate to such experiments. We present the current status of a direct measurement of the electron neutrino CCQE differential cross-section as a function of the squared four-momentum transfer to the nucleus, Q2, in MINERvA. This talk will discuss event selection, background constraints, and the flux prediction used in the calculation.

  9. Measurement of Neutrino-Induced Coherent Pion Production and the Diffractive Background in MINERvA

    NASA Astrophysics Data System (ADS)

    Gomez, Alicia; Minerva Collaboration

    2015-04-01

    Neutrino-induced coherent charged pion production is a unique neutrino-nucleus scattering process in which a muon and pion are produced while the nucleus is left in its ground state. The MINERvA experiment has made a model-independent differential cross section measurement of this process on carbon by selecting events with a muon and a pion, no evidence of nuclear break-up, and small momentum transfer to the nucleus | t | . A similar process which is a background to the measurement on carbon is diffractive pion production off the free protons in MINERvA's scintillator. This process is not modeled in the neutrino event generator GENIE. At low | t | these events have a similar final state to the aforementioned process. A study to quantify this diffractive event contribution to the background is done by emulating these diffractive events by reweighting all other GENIE-generated background events to the predicted | t | distribution of diffractive events, and then scaling to the diffractive cross section.

  10. NACA Zero Power Reactor Facility Hazards Summary

    NASA Technical Reports Server (NTRS)

    1957-01-01

    The Lewis Flight Propulsion Laboratory of the National Advisory Committee for Aeronautics proposes to build a zero power research reactor facility which will be located in the laboratory grounds near Clevelaurd, Ohio. The purpose of this report is to inform the Advisory Commit tee on Reactor Safeguards of the U. S. Atomic Energy Commission in re gard to the design of the reactor facility, the cha,acteristics of th e site, and the hazards of operation at this location, The purpose o f this reactor is to perform critical experiments, to measure reactiv ity effects, to serve as a neutron source, and to serve as a training tool. The reactor facility is described. This is followed by a discu ssion of the nuclear characteristics and the control system. Site cha racteristics are then discussed followed by a discussion of the exper iments which may be conducted in the facility. The potential hazards of the facility are then considered, particularly, the maximum credib le accident. Finally, the administrative procedure is discussed.

  11. Model Uncertainties for Valencia RPA Effect for MINERvA

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

    Gran, Richard

    2017-05-08

    This technical note describes the application of the Valencia RPA multi-nucleon effect and its uncertainty to QE reactions from the GENIE neutrino event generator. The analysis of MINERvA neutrino data in Rodrigues et al. PRL 116 071802 (2016) paper makes clear the need for an RPA suppression, especially at very low momentum and energy transfer. That published analysis does not constrain the magnitude of the effect; it only tests models with and without the effect against the data. Other MINERvA analyses need an expression of the model uncertainty in the RPA effect. A well-described uncertainty can be used for systematics for unfolding, for model errors in the analysis of non-QE samples, and as input for fitting exercises for model testing or constraining backgrounds. This prescription takes uncertainties on the parameters in the Valencia RPA model and adds a (not-as-tight) constraint from muon capture data. For MINERvA we apply it as a 2D (more » $$q_0$$,$$q_3$$) weight to GENIE events, in lieu of generating a full beyond-Fermi-gas quasielastic events. Because it is a weight, it can be applied to the generated and fully Geant4 simulated events used in analysis without a special GENIE sample. For some limited uses, it could be cast as a 1D $Q^2$ weight without much trouble. This procedure is a suitable starting point for NOvA and DUNE where the energy dependence is modest, but probably not adequate for T2K or MicroBooNE.« less

  12. Measurement of partonic nuclear effects in deep-inelastic neutrino scattering using MINERvA

    NASA Astrophysics Data System (ADS)

    Mousseau, J.; Wospakrik, M.; Aliaga, L.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Cai, T.; Carneiro, M. F.; Christy, M. E.; Chvojka, J.; da Motta, H.; Devan, J.; Dytman, S. A.; Díaz, G. A.; Eberly, B.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Golan, T.; Gran, R.; Harris, D. A.; Higuera, A.; Hurtado, K.; Kiveni, M.; Kleykamp, J.; Kordosky, M.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; Martinez Caicedo, D. A.; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman; Osta, J.; Paolone, V.; Park, J.; Patrick, C. E.; Perdue, G. N.; Rakotondravohitra, L.; Ramirez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Schmitz, D. W.; Solano Salinas, C. J.; Tagg, N.; Tice, B. G.; Valencia, E.; Walton, T.; Wolcott, J.; Zavala, G.; Zhang, D.; Minerν A Collaboration

    2016-04-01

    The MINERvA Collaboration reports a novel study of neutrino-nucleus charged-current deep inelastic scattering (DIS) using the same neutrino beam incident on targets of polystyrene, graphite, iron, and lead. Results are presented as ratios of C, Fe, and Pb to CH. The ratios of total DIS cross sections as a function of neutrino energy and flux-integrated differential cross sections as a function of the Bjorken scaling variable x are presented in the neutrino-energy range of 5-50 GeV. Based on the predictions of charged-lepton scattering ratios, good agreement is found between the data and prediction at medium x and low neutrino energy. However, the ratios appear to be below predictions in the vicinity of the nuclear shadowing region, x <0.1 . This apparent deficit, reflected in the DIS cross-section ratio at high Eν, is consistent with previous MINERvA observations [B. Tice et al. (MINERvA Collaboration), Phys. Rev. Lett. 112, 231801 (2014).] and with the predicted onset of nuclear shadowing with the axial-vector current in neutrino scattering.

  13. Measurement of partonic nuclear effects in deep-inelastic neutrino scattering using MINERvA

    DOE PAGES

    Mousseau, J.

    2016-04-19

    Here, the MINERvA Collaboration reports a novel study of neutrino-nucleus charged-current deep inelastic scattering (DIS) using the same neutrino beam incident on targets of polystyrene, graphite, iron, and lead. Results are presented as ratios of C, Fe, and Pb to CH. The ratios of total DIS cross sections as a function of neutrino energy and flux-integrated differential cross sections as a function of the Bjorken scaling variable x are presented in the neutrino-energy range of 5–50 GeV. Based on the predictions of charged-lepton scattering ratios, good agreement is found between the data and prediction at medium x and low neutrino energy.more » However, the ratios appear to be below predictions in the vicinity of the nuclear shadowing region, x < 0.1. This apparent deficit, reflected in the DIS cross-section ratio at high Eν, is consistent with previous MINERvA observations [B. Tice (MINERvA Collaboration), Phys. Rev. Lett. 112, 231801 (2014).] and with the predicted onset of nuclear shadowing with the axial-vector current in neutrino scattering.« less

  14. Sediment-transport experiments in zero-gravity

    NASA Technical Reports Server (NTRS)

    Iversen, James D.; Greeley, Ronald

    1987-01-01

    One of the important parameters in the analysis of sediment entrainment and transport is gravitational attraction. The availability of a laboratory in earth orbit would afford an opportunity to conduct experiments in zero and variable gravity environments. Elimination of gravitational attraction as a factor in such experiments would enable other critical parameters (such as particle cohesion and aerodynamic forces) to be evaluated much more accurately. A Carousel Wind Tunnel (CWT) is proposed for use in conducting experiments concerning sediment particle entrainment and transport in a space station. In order to test the concept of this wind tunnel design a one third scale model CWT was constructed and calibrated. Experiments were conducted in the prototype to determine the feasibility of studying various aeolian processes and the results were compared with various numerical analysis. Several types of experiments appear to be feasible utilizing the proposed apparatus.

  15. Sediment-transport experiments in zero-gravity

    NASA Technical Reports Server (NTRS)

    Iversen, J. D.; Greeley, R.

    1986-01-01

    One of the important parameters in the analysis of sediment entrainment and transport is gravitational attraction. The availability of a laboratory in Earth orbit would afford an opportunity to conduct experiments in zero and variable gravity environments. Elimination of gravitational attraction as a factor in such experiments would enable other critical parameters (such as particle cohesion and aerodynamic forces) to be evaluated much more accurately. A Carousel Wind Tunnel (CWT) is proposed for use in conducting experiments concerning sediment particle entrainment and transport in a space station. In order to test the concept of this wind tunnel design a one third scale model CWT was constructed and calibrated. Experiments were conducted in the prototype to determine the feasibility of studying various aeolian processes and the results were compared with various numerical analysis. Several types of experiments appear to be feasible utilizing the proposed apparatus.

  16. Reactivity loss validation of high burn-up PWR fuels with pile-oscillation experiments in MINERVE

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

    Leconte, P.; Vaglio-Gaudard, C.; Eschbach, R.

    2012-07-01

    The ALIX experimental program relies on the experimental validation of the spent fuel inventory, by chemical analysis of samples irradiated in a PWR between 5 and 7 cycles, and also on the experimental validation of the spent fuel reactivity loss with bum-up, obtained by pile-oscillation measurements in the MINERVE reactor. These latter experiments provide an overall validation of both the fuel inventory and of the nuclear data responsible for the reactivity loss. This program offers also unique experimental data for fuels with a burn-up reaching 85 GWd/t, as spent fuels in French PWRs never exceeds 70 GWd/t up to now.more » The analysis of these experiments is done in two steps with the APOLLO2/SHEM-MOC/CEA2005v4 package. In the first one, the fuel inventory of each sample is obtained by assembly calculations. The calculation route consists in the self-shielding of cross sections on the 281 energy group SHEM mesh, followed by the flux calculation by the Method Of Characteristics in a 2D-exact heterogeneous geometry of the assembly, and finally a depletion calculation by an iterative resolution of the Bateman equations. In the second step, the fuel inventory is used in the analysis of pile-oscillation experiments in which the reactivity of the ALIX spent fuel samples is compared to the reactivity of fresh fuel samples. The comparison between Experiment and Calculation shows satisfactory results with the JEFF3.1.1 library which predicts the reactivity loss within 2% for burn-up of {approx}75 GWd/t and within 4% for burn-up of {approx}85 GWd/t. (authors)« less

  17. Towards zero-power ICT.

    PubMed

    Gammaitoni, Luca; Chiuchiú, D; Madami, M; Carlotti, G

    2015-06-05

    Is it possible to operate a computing device with zero energy expenditure? This question, once considered just an academic dilemma, has recently become strategic for the future of information and communication technology. In fact, in the last forty years the semiconductor industry has been driven by its ability to scale down the size of the complementary metal-oxide semiconductor-field-effect transistor, the building block of present computing devices, and to increase computing capability density up to a point where the power dissipated in heat during computation has become a serious limitation. To overcome such a limitation, since 2004 the Nanoelectronics Research Initiative has launched a grand challenge to address the fundamental limits of the physics of switches. In Europe, the European Commission has recently funded a set of projects with the aim of minimizing the energy consumption of computing. In this article we briefly review state-of-the-art zero-power computing, with special attention paid to the aspects of energy dissipation at the micro- and nanoscales.

  18. Towards zero-power ICT

    NASA Astrophysics Data System (ADS)

    Gammaitoni, Luca; Chiuchiú, D.; Madami, M.; Carlotti, G.

    2015-06-01

    Is it possible to operate a computing device with zero energy expenditure? This question, once considered just an academic dilemma, has recently become strategic for the future of information and communication technology. In fact, in the last forty years the semiconductor industry has been driven by its ability to scale down the size of the complementary metal-oxide semiconductor-field-effect transistor, the building block of present computing devices, and to increase computing capability density up to a point where the power dissipated in heat during computation has become a serious limitation. To overcome such a limitation, since 2004 the Nanoelectronics Research Initiative has launched a grand challenge to address the fundamental limits of the physics of switches. In Europe, the European Commission has recently funded a set of projects with the aim of minimizing the energy consumption of computing. In this article we briefly review state-of-the-art zero-power computing, with special attention paid to the aspects of energy dissipation at the micro- and nanoscales.

  19. Low power electromagnetic flowmeter providing accurate zero set

    NASA Technical Reports Server (NTRS)

    Fryer, T. B. (Inventor)

    1971-01-01

    A low power, small size electromagnetic flowmeter system is described which produces a zero output signal for zero flow. The system comprises an air core type electromagnetic flow transducer, a field current supply circuit for the transducer coils and a pre-amplifier and demodulation circuit connected to the output of the transducer. To prevent spurious signals at zero flow, separate, isolated power supplies are provided for the two circuits. The demodulator includes a pair of synchronous rectifiers which are controlled by signals from the field current supply circuit. Pulse transformer connected in front of the synchronous rectifiers provide isolation between the two circuits.

  20. Experience using individually supplied heater rods in critical power testing of advanced BWR fuel

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

    Majed, M.; Morback, G.; Wiman, P.

    1995-09-01

    The ABB Atom FRIGG loop located in Vasteras Sweden has during the last six years given a large experience of critical power measurements for BWR fuel designs using indirectly heated rods with individual power supply. The loop was built in the sixties and designed for maximum 100 bar pressure. Testing up to the mid eighties was performed with directly heated rods using a 9 MW, 80 kA power supply. Providing test data to develop critical power correlations for BWR fuel assemblies requires testing with many radial power distributions over the full range of hydraulic conditions. Indirectly heated rods give largemore » advantages for the testing procedure, particularly convenient for variation of individual rod power. A test method being used at Stern Laboratories (formerly Westinghouse Canada) since the early sixties, allows one fuel assembly to simulate all required radial power distributions. This technique requires reliable indirectly heated rods with independently controlled power supplies and uses insulated electric fuel rod simulators with built-in instrumentation. The FRIGG loop was adapted to this system in 1987. A 4MW power supply with 10 individual units was then installed, and has since been used for testing 24 and 25 rod bundles simulating one subbundle of SVEA-96/100 type fuel assemblies. The experience with the system is very good, as being presented, and it is selected also for a planned upgrading of the facility to 15 MW.« less

  1. Light-Actuated Micromechanical Relays for Zero-Power Infrared Detection

    DTIC Science & Technology

    2017-03-01

    Light-Actuated Micromechanical Relays for Zero-Power Infrared Detection Zhenyun Qian, Sungho Kang, Vageeswar Rajaram, Cristian Cassella, Nicol E...near-zero power infrared (IR) detection . Differently from any existing switching element, the proposed LMR relies on a plasmonically-enhanced...chip enabling the monolithic fabrication of multiple LMRs connected together to form a logic topology suitable for the detection of specific

  2. Measurement of Muon Neutrino Charged Current Single $$\\pi^0$$ Production on Hydrocarbon using MINERvA

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

    Altinok, Ozgur

    A sample of charged-current single pion production events for the semi- exclusive channel ν µ + CH → µ -π 0 + nucleon(s) has been obtained using neutrino exposures of the MINERvA detector. Differential cross sections for muon momentum, muon production angle, pion momentum, pion production angle, and four-momentum transfer square Q 2 are reported and are compared to a GENIE-based simulation. The cross section versus neutrino energy is also re- ported. The effects of pion final-state interactions on these cross sections are investigated. The effect of baryon resonance suppression at low Q 2 is examined and an event re-weight used by two previous experiments is shown to improve the data versus simulation agreement. The differential cross sections for Q 2 for Eν < 4.0 GeV and E ν ≥ 4.0 GeV are examined and the shapes of these distributions are compared to those from the experiment’smore » $$\\bar{v}$$ µ-CC (π 0) measurement. The polarization of the pπ 0 system is measured and compared to the simulation predictions. The hadronic invariant mass W distribution is examined for evidence of resonance content, and a search is reported for evidence of a two-particle two-hole (2p2h) contribution. All of the differential cross-section measurements of this Thesis are compared with published MINERvA measurements for ν µ-CC (π +) and \\bar{v}$ µ-CC (π 0) processes.« less

  3. MINERVE flood warning and management project. What is computed, what is required and what is visualized?

    NASA Astrophysics Data System (ADS)

    Garcia Hernandez, J.; Boillat, J.-L.; Schleiss, A.

    2010-09-01

    , turbine and bottom outlet preventive operations can be proposed to the hydropower plants operators in order to store water inflows and to stop turbining during the peak flow. Appropriate operations can thus reduce the peak discharges in the Rhone River and its tributaries, limiting or avoiding damages. Results presentation in a clear and understandable way is an important goal of the project and is considered as one of the main focuses. The MINERVE project is developed in partnership by the Swiss Federal Office for Environment (FOEV), Services of Roads and Water courses as well as Water Power and Energy of the Wallis Canton and Service of Water, Land and Sanitation of the Vaud Canton. The Swiss Weather Service (MeteoSwiss) provides the weather forecasts and hydroelectric companies communicate specific information regarding the hydropower plants. Scientific developments are entrusted to two entities of the Ecole Polytechnique Fédérale de Lausanne (EPFL), the Hydraulic Constructions Laboratory (LCH) and the Ecohydrology Laboratory (ECHO), as well as to the Institute of Geomatics and Analysis of Risk (IGAR) of Lausanne University (UNIL).

  4. MINERvA Measurement of Neutrino Charged-Current Cross Section Ratios of Nuclei C, Fe, and Pb to CH at Energies of a Few GeV

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

    Gran, Richard

    2016-06-02

    The MINERvA experiment is designed to measure neutrino cross sections for different nuclei using substantially similar fiducial and tracking environments. This allows for reduced systematics in the ratio to better see the evolution of the cross section with the size of the nucleus. The first such result is an inclusive charged current cross section ratio as a function of energy from and the kinematic quantity Bjorken x for nuclei Pb, Fe, and C relative to plastic scintillator CH. The measurement is made for neutrino energies from 2 to 20 GeV. In the past, charged lepton scattering ratios of heavier nucleimore » to deuterium have revealed interesting structure such as the EMC effect. These ratios were restricted to purely deep inelastic scattering data whereas these ratios to different nuclei in MINERvA are sensitive to the elastic scattering as well as resonance production regions. Significant deviations from the baseline scattering model are observed, and suggest new theory work to investigate these ratios.« less

  5. Critical experiments at Sandia National Laboratories : technical meeting on low-power critical facilities and small reactors.

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

    Harms, Gary A.; Ford, John T.; Barber, Allison Delo

    2010-11-01

    Sandia National Laboratories (SNL) has conducted radiation effects testing for the Department of Energy (DOE) and other contractors supporting the DOE since the 1960's. Over this period, the research reactor facilities at Sandia have had a primary mission to provide appropriate nuclear radiation environments for radiation testing and qualification of electronic components and other devices. The current generation of reactors includes the Annular Core Research Reactor (ACRR), a water-moderated pool-type reactor, fueled by elements constructed from UO2-BeO ceramic fuel pellets, and the Sandia Pulse Reactor III (SPR-III), a bare metal fast burst reactor utilizing a uranium-molybdenum alloy fuel. The SPR-IIImore » is currently defueled. The SPR Facility (SPRF) has hosted a series of critical experiments. A purpose-built critical experiment was first operated at the SPRF in the late 1980's. This experiment, called the Space Nuclear Thermal Propulsion Critical Experiment (CX), was designed to explore the reactor physics of a nuclear thermal rocket motor. This experiment was fueled with highly-enriched uranium carbide fuel in annular water-moderated fuel elements. The experiment program was completed and the fuel for the experiment was moved off-site. A second critical experiment, the Burnup Credit Critical Experiment (BUCCX) was operated at Sandia in 2002. The critical assembly for this experiment was based on the assembly used in the CX modified to accommodate low-enriched pin-type fuel in water moderator. This experiment was designed as a platform in which the reactivity effects of specific fission product poisons could be measured. Experiments were carried out on rhodium, an important fission product poison. The fuel and assembly hardware for the BUCCX remains at Sandia and is available for future experimentation. The critical experiment currently in operation at the SPRF is the Seven Percent Critical Experiment (7uPCX). This experiment is designed to provide

  6. Probing nuclear effects using single-transverse kinematic imbalance with MINERvA

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

    Lu, X. -G.; Betancourt, M.

    2016-08-15

    Kinematic imbalance of the final-state particles in the plane transverse to the neutrino direction provides a sensitive probe of nuclear effects. In this contribution, we report the MINERvA measurement of the single-transverse kinematic imbalance in neutrino charged-current quasielastic-like events on CH targets. To improve the momentum measurements of the final-state particles, we develop a method to select elastically scattering contained (ESC) protons and a general procedure to correct the transverse momentum scales.

  7. Benchmark Evaluation of Start-Up and Zero-Power Measurements at the High-Temperature Engineering Test Reactor

    DOE PAGES

    Bess, John D.; Fujimoto, Nozomu

    2014-10-09

    Benchmark models were developed to evaluate six cold-critical and two warm-critical, zero-power measurements of the HTTR. Additional measurements of a fully-loaded subcritical configuration, core excess reactivity, shutdown margins, six isothermal temperature coefficients, and axial reaction-rate distributions were also evaluated as acceptable benchmark experiments. Insufficient information is publicly available to develop finely-detailed models of the HTTR as much of the design information is still proprietary. However, the uncertainties in the benchmark models are judged to be of sufficient magnitude to encompass any biases and bias uncertainties incurred through the simplification process used to develop the benchmark models. Dominant uncertainties in themore » experimental keff for all core configurations come from uncertainties in the impurity content of the various graphite blocks that comprise the HTTR. Monte Carlo calculations of keff are between approximately 0.9 % and 2.7 % greater than the benchmark values. Reevaluation of the HTTR models as additional information becomes available could improve the quality of this benchmark and possibly reduce the computational biases. High-quality characterization of graphite impurities would significantly improve the quality of the HTTR benchmark assessment. Simulation of the other reactor physics measurements are in good agreement with the benchmark experiment values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.« less

  8. Comparative study on neutron data in integral experiments of MYRRHA mockup critical cores in the VENUS-F reactor

    NASA Astrophysics Data System (ADS)

    Krása, Antonín; Kochetkov, Anatoly; Baeten, Peter; Vittiglio, Guido; Wagemans, Jan; Bécares, Vicente

    2017-09-01

    VENUS-F is a fast, zero-power reactor with 30% wt. metallic uranium fuel and solid lead as coolant simulator. It serves as a mockup of the MYRRHA reactor core. This paper describes integral experiments performed in two critical VENUS-F core configurations (with and without graphite reflector). Discrepancies between experiments and Monte Carlo calculations (MCNP5) of keff, fission rate spatial distribution and reactivity effects (lead void and fuel Doppler) depending on a nuclear data library used (JENDL-4.0, ENDF-B-VII.1, JEFF-3.1.2, 3.2, 3.3T2) are presented.

  9. Zero-Field Ambient-Pressure Quantum Criticality in the Stoichiometric Non-Fermi Liquid System CeRhBi

    NASA Astrophysics Data System (ADS)

    Anand, Vivek K.; Adroja, Devashibhai T.; Hillier, Adrian D.; Shigetoh, Keisuke; Takabatake, Toshiro; Park, Je-Geun; McEwen, Keith A.; Pixley, Jedediah H.; Si, Qimiao

    2018-06-01

    We present the spin dynamics study of a stoichiometric non-Fermi liquid (NFL) system CeRhBi, using low-energy inelastic neutron scattering (INS) and muon spin relaxation (μSR) measurements. It shows evidence for an energy-temperature (E/T) scaling in the INS dynamic response and a time-field (t/Hη) scaling of the μSR asymmetry function indicating a quantum critical behavior in this compound. The E/T scaling reveals a local character of quantum criticality consistent with the power-law divergence of the magnetic susceptibility, logarithmic divergence of the magnetic heat capacity and T-linear resistivity at low temperature. The occurrence of NFL behavior and local criticality over a very wide dynamical range at zero field and ambient pressure without any tuning in this stoichiometric heavy fermion compound is striking, making CeRhBi a model system amenable to in-depth studies for quantum criticality.

  10. Validation of the new code package APOLLO2.8 for accurate PWR neutronics calculations

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

    Santamarina, A.; Bernard, D.; Blaise, P.

    2013-07-01

    This paper summarizes the Qualification work performed to demonstrate the accuracy of the new APOLLO2.S/SHEM-MOC package based on JEFF3.1.1 nuclear data file for the prediction of PWR neutronics parameters. This experimental validation is based on PWR mock-up critical experiments performed in the EOLE/MINERVE zero-power reactors and on P.I. Es on spent fuel assemblies from the French PWRs. The Calculation-Experiment comparison for the main design parameters is presented: reactivity of UOX and MOX lattices, depletion calculation and fuel inventory, reactivity loss with burnup, pin-by-pin power maps, Doppler coefficient, Moderator Temperature Coefficient, Void coefficient, UO{sub 2}-Gd{sub 2}O{sub 3} poisoning worth, Efficiency ofmore » Ag-In-Cd and B4C control rods, Reflector Saving for both standard 2-cm baffle and GEN3 advanced thick SS reflector. From this qualification process, calculation biases and associated uncertainties are derived. This code package APOLLO2.8 is already implemented in the ARCADIA new AREVA calculation chain for core physics and is currently under implementation in the future neutronics package of the French utility Electricite de France. (authors)« less

  11. Zero-gravity cloud physics laboratory: Candidate experiments definition and preliminary concept studies

    NASA Technical Reports Server (NTRS)

    Eaton, L. R.; Greco, R. V.; Hollinden, A. B.

    1973-01-01

    The candidate definition studies on the zero-g cloud physics laboratory are covered. This laboratory will be an independent self-contained shuttle sortie payload. Several critical technology areas have been identified and studied to assure proper consideration in terms of engineering requirements for the final design. Areas include chambers, gas and particle generators, environmental controls, motion controls, change controls, observational techniques, and composition controls. This unique laboratory will allow studies to be performed without mechanical, aerodynamics, electrical, or other type techniques to support the object under study. This report also covers the candidate experiment definitions, chambers and experiment classes, laboratory concepts and plans, special supporting studies, early flight opportunities and payload planning data for overall shuttle payload requirements assessments.

  12. NGEE Arctic Zero Power Warming PhenoCamera Images, Barrow, Alaska, 2016

    DOE Data Explorer

    Shawn Serbin; Andrew McMahon; Keith Lewin; Kim Ely; Alistair Rogers

    2016-11-14

    StarDot NetCam SC pheno camera images collected from the top of the Barrow, BEO Sled Shed. The camera was installed to monitor the BNL TEST group's prototype ZPW (Zero Power Warming) chambers during the growing season of 2016 (including early spring and late fall). Images were uploaded to the BNL FTP server every 10 minutes and renamed with the date and time of the image. See associated data "Zero Power Warming (ZPW) Chamber Prototype Measurements, Barrow, Alaska, 2016" http://dx.doi.org/10.5440/1343066.

  13. The paradoxical zero reflection at zero energy

    NASA Astrophysics Data System (ADS)

    Ahmed, Zafar; Sharma, Vibhu; Sharma, Mayank; Singhal, Ankush; Kaiwart, Rahul; Priyadarshini, Pallavi

    2017-03-01

    Usually, the reflection probability R(E) of a particle of zero energy incident on a potential which converges to zero asymptotically is found to be 1: R(0)=1. But earlier, a paradoxical phenomenon of zero reflection at zero energy (R(0)=0) has been revealed as a threshold anomaly. Extending the concept of half-bound state (HBS) of 3D, here we show that in 1D when a symmetric (asymmetric) attractive potential well possesses a zero-energy HBS, R(0)=0 (R(0)\\ll 1). This can happen only at some critical values q c of an effective parameter q of the potential well in the limit E\\to {0}+. We demonstrate this critical phenomenon in two simple analytically solvable models: square and exponential wells. However, in numerical calculations, even for these two models R(0)=0 is observed only as extrapolation to zero energy from low energies, close to a precise critical value q c. By numerical investigation of a variety of potential wells, we conclude that for a given potential well (symmetric or asymmetric), we can adjust the effective parameter q to have a low reflection at a low energy.

  14. Measurement of the Antineutrino Double-Differential Charged-Current Quasi-Elastic Scattering Cross Section at MINERvA

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

    Patrick, Cheryl

    Next-generation neutrino oscillation experiments, such as DUNE and Hyper-Kamiokande, hope to measure charge-parity (CP) violation in the lepton sector. In order to do this, they must dramatically reduce their current levels of uncertainty, particularly those due to neutrino-nucleus interaction models. As CP violation is a measure of the difference between the oscillation properties of neutrinos and antineutrinos, data about how the less-studied antineutrinos interact is especially valuable. We present the MINERvA experiment's first double-differential scattering cross sections for antineutrinos on scintillator, in the few-GeV range relevant to experiments such as DUNE and NOvA. We also present total antineutrino-scintillator quasi-elastic crossmore » sections as a function of energy, which we compare to measurements from previous experiments. As well as being useful to help reduce oscillation experiments' uncertainty, our data can also be used to study the prevalence of various cor relation and final-state interaction effects within the nucleus. We compare to models produced by different model generators, and are able to draw first conclusions about the predictions of these models.« less

  15. Experiments on the properties of superfluid helium in zero gravity

    NASA Technical Reports Server (NTRS)

    Mason, P.; Collins, D.; Petrac, D.; Yang, L.; Edeskuty, F.; Williamson, K.

    1976-01-01

    The paper describes a research program designed to study the behavior of superfluid liquid helium in low and zero gravity in order to determine the properties which are critically important to its use as a stored cryogen for cooling scientific instruments aboard spacecraft for periods up to several months. The experiment program consists of a series of flights of an experiment package on a free-fall trajectory both on an aircraft and on a rocket. The objectives are to study thickness of thin films of helium as a function of acceleration, heat transfer in thin films, heat transfer across copper-liquid helium interfaces, fluid dynamics of bulk helium in high and low accelerations and under various conditions of rotations, alternate methods of separation of liquid and vapor phases and of efficient venting of the vapor, and undesirable thermomechanical oscillations in the vent pipes. Preliminary results from aircraft tests are discussed.

  16. ZeroCal: Automatic MAC Protocol Calibration

    NASA Astrophysics Data System (ADS)

    Meier, Andreas; Woehrle, Matthias; Zimmerling, Marco; Thiele, Lothar

    Sensor network MAC protocols are typically configured for an intended deployment scenario once and for all at compile time. This approach, however, leads to suboptimal performance if the network conditions deviate from the expectations. We present ZeroCal, a distributed algorithm that allows nodes to dynamically adapt to variations in traffic volume. Using ZeroCal, each node autonomously configures its MAC protocol at runtime, thereby trying to reduce the maximum energy consumption among all nodes. While the algorithm is readily usable for any asynchronous low-power listening or low-power probing protocol, we validate and demonstrate the effectiveness of ZeroCal on X-MAC. Extensive testbed experiments and simulations indicate that ZeroCal quickly adapts to traffic variations. We further show that ZeroCal extends network lifetime by 50% compared to an optimal configuration with identical and static MAC parameters at all nodes.

  17. Polish Experience of Implementing Vision Zero.

    PubMed

    Jamroz, Kazimierz; Michalski, Lech; Żukowska, Joanna

    2017-01-01

    The aim of this study is to present an outline and the principles of Poland's road safety strategic programming as it has developed over the last 25 years since the first Integrated Road Safety System with a strong focus on Sweden's "Vision Zero". Countries that have successfully improved road safety have done so by following strategies centred around the idea that people are not infallible and will make mistakes. The human body can only take a limited amount of energy upon impact, so roads, vehicles and road safety programmes must be designed to address this. The article gives a summary of Poland's experience of programming preventative measures that have "Vision Zero" as their basis. It evaluates the effectiveness of relevant programmes.

  18. Feasibility study of a zero-gravity (orbital) atmospheric cloud physics experiments laboratory

    NASA Technical Reports Server (NTRS)

    Hollinden, A. B.; Eaton, L. R.

    1972-01-01

    A feasibility and concepts study for a zero-gravity (orbital) atmospheric cloud physics experiment laboratory is discussed. The primary objective was to define a set of cloud physics experiments which will benefit from the near zero-gravity environment of an orbiting spacecraft, identify merits of this environment relative to those of groundbased laboratory facilities, and identify conceptual approaches for the accomplishment of the experiments in an orbiting spacecraft. Solicitation, classification and review of cloud physics experiments for which the advantages of a near zero-gravity environment are evident are described. Identification of experiments for potential early flight opportunities is provided. Several significant accomplishments achieved during the course of this study are presented.

  19. Medical Education to Enhance Critical Consciousness: Facilitators' Experiences.

    PubMed

    Zaidi, Zareen; Vyas, Rashmi; Verstegen, Danielle; Morahan, Page; Dornan, Tim

    2017-11-01

    To analyze educators' experiences of facilitating cultural discussions in two global health professions education programs and what these experiences had taught them about critical consciousness. A multicultural research team conducted in-depth interviews with 16 faculty who had extensive experience facilitating cultural discussions. They analyzed transcripts of the interviews thematically, drawing sensitizing insights from Gramsci's theory of cultural hegemony. Collaboration and conversation helped the team self-consciously examine their positions toward the data set and be critically reflexive. Participant faculty used their prior experience facilitating cultural discussions to create a "safe space" in which learners could develop critical consciousness. During multicultural interactions they recognized and explicitly addressed issues related to power differentials, racism, implicit bias, and gender bias. They noted the need to be "facile in attending to pain" as learners brought up traumatic experiences and other sensitive issues including racism and the impact of power dynamics. They built relationships with learners by juxtaposing and exploring the sometimes-conflicting norms of different cultures. Participants were reflective about their own understanding and tendency to be biased. They aimed to break free of such biases while role modeling how to have the courage to speak up. Experience had given facilitators in multicultural programs an understanding of their responsibility to promote critical consciousness and social justice. How faculty without prior experience or expertise could develop those values and skills is a topic for future research.

  20. Zero-gravity cloud physics laboratory: Experiment program definition and preliminary laboratory concept studies

    NASA Technical Reports Server (NTRS)

    Eaton, L. R.; Greco, E. V.

    1973-01-01

    The experiment program definition and preliminary laboratory concept studies on the zero G cloud physics laboratory are reported. This program involves the definition and development of an atmospheric cloud physics laboratory and the selection and delineations of a set of candidate experiments that must utilize the unique environment of zero gravity or near zero gravity.

  1. Tribology experiment in zero gravity

    NASA Technical Reports Server (NTRS)

    Pan, C. H. T.; Gause, R. L.; Whitaker, A. F.

    1984-01-01

    A tribology experiment in zero gravity was performed during the orbital flight of Spacelab 1 to study the motion of liquid lubricants over solid surfaces. The absence of a significant gravitational force facilitates studies of the motion of liquid lubricants over solid surfaces as controlled by interfacial and capillary forces. Observations were made of phenomena associated with the liquid on one solid surface and also with the liquid between a pair of closely spaced surfaces. Typical photographic records obtained on Spacelab 1 are described.

  2. Zero-power infrared digitizers based on plasmonically enhanced micromechanical photoswitches

    NASA Astrophysics Data System (ADS)

    Qian, Zhenyun; Kang, Sungho; Rajaram, Vageeswar; Cassella, Cristian; McGruer, Nicol E.; Rinaldi, Matteo

    2017-10-01

    State-of-the-art sensors use active electronics to detect and discriminate light, sound, vibration and other signals. They consume power constantly, even when there is no relevant data to be detected, which limits their lifetime and results in high costs of deployment and maintenance for unattended sensor networks. Here we propose a device concept that fundamentally breaks this paradigm—the sensors remain dormant with near-zero power consumption until awakened by a specific physical signature associated with an event of interest. In particular, we demonstrate infrared digitizing sensors that consist of plasmonically enhanced micromechanical photoswitches (PMPs) that selectively harvest the impinging electromagnetic energy in design-defined spectral bands of interest, and use it to create mechanically a conducting channel between two electrical contacts, without the need for any additional power source. Our zero-power digitizing sensor prototypes produce a digitized output bit (that is, a large and sharp off-to-on state transition with an on/off conductance ratio >1012 and subthreshold slope >9 dec nW-1) when exposed to infrared radiation in a specific narrow spectral band (∼900 nm bandwidth in the mid-infrared) with the intensity above a power threshold of only ∼500 nW, which is not achievable with any existing photoswitch technologies.

  3. Dead time corrections using the backward extrapolation method

    NASA Astrophysics Data System (ADS)

    Gilad, E.; Dubi, C.; Geslot, B.; Blaise, P.; Kolin, A.

    2017-05-01

    Dead time losses in neutron detection, caused by both the detector and the electronics dead time, is a highly nonlinear effect, known to create high biasing in physical experiments as the power grows over a certain threshold, up to total saturation of the detector system. Analytic modeling of the dead time losses is a highly complicated task due to the different nature of the dead time in the different components of the monitoring system (e.g., paralyzing vs. non paralyzing), and the stochastic nature of the fission chains. In the present study, a new technique is introduced for dead time corrections on the sampled Count Per Second (CPS), based on backward extrapolation of the losses, created by increasingly growing artificially imposed dead time on the data, back to zero. The method has been implemented on actual neutron noise measurements carried out in the MINERVE zero power reactor, demonstrating high accuracy (of 1-2%) in restoring the corrected count rate.

  4. Irradiation campaign in the EOLE critical facility of fiber optic Bragg gratings dedicated to the online temperature measurement in zero power research reactors

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

    Mellier, Frederic; Cheymol, Guy; Destouches, Christophe

    2015-07-01

    The control of temperature during operation of zero power research reactors participates to the overall control of experimentation conditions and reveals itself of a major importance more especially when measuring small multiplication factor variations. Within the framework of the refurbishment of the MASURCA facility, the development of a new temperature measurement system based on the optical fiber Bragg grating (FBG) technology is under consideration. In a first step, a series of FBGs is irradiated in the EOLE critical facility with the aim to select the most appropriate. Online temperature measurements are performed during a set of irradiations that should allowmore » reaching a fast neutron fluence of some 10{sup 14} n.cm{sup -2}. The results obtained, more especially the Bragg wavelength shifts during the irradiation campaign, are discussed in this paper and compared to data from standard PT100 temperature sensors to highlight possible radiation effects on sensor performances. Work to be conducted during the second step of the project, aiming to a feasibility demonstration using a MASURCA assembly, is also presented. (authors)« less

  5. Current Mode Neutron Noise Measurements in the Zero Power Reactor CROCUS

    NASA Astrophysics Data System (ADS)

    Pakari, O.; Lamirand, V.; Perret, G.; Braun, L.; Frajtag, P.; Pautz, A.

    2018-01-01

    The present article is an overview of developments and results regarding neutron noise measurements in current mode at the CROCUS zero power facility. Neutron noise measurements offer a non-invasive method to determine kinetic reactor parameters such as the prompt decay constant at criticality α = βeff / λ, the effective delayed neutron fraction βeff, and the mean generation time λ for code validation efforts. At higher detection rates, i.e. above 2×104 cps in the used configuration at 0.1 W, the previously employed pulse charge amplification electronics with BF3 detectors yielded erroneous results due to dead time effects. Future experimental needs call for higher sensitivity in detectors, higher detection rates or higher reactor powers, and thus a generally more versatile measurement system. We, therefore, explored detectors operated with current mode acquisition electronics to accommodate the need. We approached the matter in two ways: 1) By using the two compensated 10B-coated ionization chambers available in CROCUS as operational monitors. The compensated current signal of these chambers was extracted from coremonitoring output channels. 2) By developing a new current mode amplification station to be used with other available detectors in core. Characteristics and first noise measurements of the new current system are presented. We implemented post-processing of the current signals from 1)and 2) with the APSD/CPSD method to determine α. At two critical states (0.5 and 1.5 W), using the 10B ionization chambers and their CPSD estimate, the prompt decay constant was measured after 1.5 hours to be α=(156.9 ± 4.3) s-1 (1σ). This result is within 1σ of statistical uncertainties of previous experiments and MCNPv5-1.6 predictions using the ENDF/B-7.1 library. The newsystem connected to a CFUL01 fission chamber using the APSDestimate at 100 mW after 33 min yielded α = (160.8 ± 6.3) s-1, also within 1σ agreement. The improvements to previous neutron noise

  6. Zero-power autonomous buoyancy system controlled by microbial gas production

    NASA Astrophysics Data System (ADS)

    Wu, Peter K.; Fitzgerald, Lisa A.; Biffinger, Justin C.; Spargo, Barry J.; Houston, Brian H.; Bucaro, Joseph A.; Ringeisen, Bradley R.

    2011-05-01

    A zero-power ballast control system that could be used to float and submerge a device solely using a gas source was built and tested. This system could be used to convey sensors, data loggers, and communication devices necessary for water quality monitoring and other applications by periodically maneuvering up and down a water column. Operational parameters for the system such as duration of the submerged and buoyant states can be varied according to its design. The gas source can be of any origin, e.g., compressed air, underwater gas vent, gas produced by microbes, etc. The zero-power ballast system was initially tested using a gas pump and further tested using gas produced by Clostridium acetobutylicum. Using microbial gas production as the only source of gas and no electrical power during operation, the system successfully floated and submerged periodically with a period of 30 min for at least 24 h. Together with microbial fuel cells, this system opens up possibilities for underwater monitoring systems that could function indefinitely.

  7. Attachment Theory in Supervision: A Critical Incident Experience

    ERIC Educational Resources Information Center

    Pistole, M. Carole; Fitch, Jenelle C.

    2008-01-01

    Critical incident experiences are a powerful source of counselor development (T. M. Skovholt & P. R. McCarthy, 1988a, 1988b) and are relevant to attachment issues. An attachment theory perspective of supervision is presented and applied to a critical incident case scenario. By focusing on the behavioral systems (i.e., attachment, caregiving, and…

  8. 78 FR 72673 - Zero Rate Reactive Power Rate Schedules; Notice of Staff Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-03

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD14-1-000] Zero Rate Reactive Power Rate Schedules; Notice of Staff Workshop This notice establishes the location and date for... located at: https://www.ferc.gov/whats-new/registration/zero-rate-12-11-13-form.asp . The workshop will...

  9. Reanalysis of the gas-cooled fast reactor experiments at the zero power facility proteus - Spectral indices

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

    Perret, G.; Pattupara, R. M.; Girardin, G.

    2012-07-01

    The gas-cooled fast reactor (GCFR) concept was investigated experimentally in the PROTEUS zero power facility at the Paul Scherrer Inst. during the 1970's. The experimental program was aimed at neutronics studies specific to the GCFR and at the validation of nuclear data in fast spectra. A significant part of the program used thorium oxide and thorium metal fuel either distributed quasi-homogeneously in the reference PuO{sub 2}/UO{sub 2} lattice or introduced in the form of radial and axial blanket zones. Experimental results obtained at the time are still of high relevance in view of the current consideration of the Gas-cooled Fastmore » Reactor (GFR) as a Generation-IV nuclear system, as also of the renewed interest in the thorium cycle. In this context, some of the experiments have been modeled with modern Monte Carlo codes to better account for the complex PROTEUS whole-reactor geometry and to allow validating recent continuous neutron cross-section libraries. As a first step, the MCNPX model was used to test the JEFF-3.1, JEFF-3.1.1, ENDF/B-VII.0 and JENDL-3.3 libraries against spectral indices, notably involving fission and capture of {sup 232}Th and {sup 237}Np, measured in GFR-like lattices. (authors)« less

  10. 78 FR 63176 - Notice Announcing Workshop; Zero Rate Reactive Power Rate Schedules

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD14-1-000] Notice Announcing Workshop; Zero Rate Reactive Power Rate Schedules Concurrent with this notice, the Commission is issuing an order in Chehalis Power Generating, L.P., Docket No. ER05-1056-007 clarifying its policy...

  11. Experiments with the Skylab fire detectors in zero gravity

    NASA Technical Reports Server (NTRS)

    Linford, R. M. F.

    1972-01-01

    The Skylab fire detector was evaluated in a zero gravity environment. To conduct the test, small samples of spacecraft materials were ignited in a 5 psi oxygen-rich atmosphere inside a combustion chamber. The chamber free-floated in the cabin of a C-135 aircraft, as the aircraft executed a Keplerian parabola. Up to 10 seconds of zero-gravity combustion were achieved. The Skylab fire-detector tubes viewed the flames from a simulated distance of 3m, and color movies were taken to record the nature of the fire. The experiments established the unique form of zero-gravity fires for a wide range of materials. From the tube-output data, the alarm threshold and detector time constant were verified for the Skylab Fire Detection System.

  12. Building America Case Study: New Town Builders' Power of Zero Energy Center, Denver, Colorado (Brochure)

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

    Not Available

    New Town Builders, a builder of energy efficient homes in Denver, Colorado, offers a zero energy option for all the homes it builds. To attract a wide range of potential homebuyers to its energy efficient homes, New Town Builders created a 'Power of Zero Energy Center' linked to its model home in the Stapleton community of Denver. This case study presents New Town Builders' marketing approach, which is targeted to appeal to homebuyers' emotions rather than overwhelming homebuyers with scientific details about the technology. The exhibits in the Power of Zero Energy Center focus on reduced energy expenses for themore » homeowner, improved occupant comfort, the reputation of the builder, and the lack of sacrificing the homebuyers' desired design features to achieve zero net energy in the home. The case study also contains customer and realtor testimonials related to the effectiveness of the Center in influencing homebuyers to purchase a zero energy home.« less

  13. Zero Boil-Off Tank (ZBOT) Experiment

    NASA Technical Reports Server (NTRS)

    Mcquillen, John

    2016-01-01

    The Zero-Boil-Off Tank (ZBOT) experiment has been developed as a small scale ISS experiment aimed at delineating important fluid flow, heat and mass transport, and phase change phenomena that affect cryogenic storage tank pressurization and pressure control in microgravity. The experiments use a simulant transparent low boiling point fluid (PnP) in a sealed transparent Dewar to study and quantify: (a) fluid flow and thermal stratification during pressurization; (b) mixing, thermal destratification, depressurization, and jet-ullage penetration during pressure control by jet mixing. The experiment will provide valuable microgravity empirical two-phase data associated with the above-mentioned physical phenomena through highly accurate local wall and fluid temperature and pressure measurements, full-field phase-distribution and flow visualization. Moreover, the experiments are performed under tightly controlled and definable heat transfer boundary conditions to provide reliable high-fidelity data and precise input as required for validation verification of state-of-the-art two-phase CFD models developed as part of this research and by other groups in the international scientific and cryogenic fluid management communities.

  14. View of Payload specialist Paul Scully-Power during Zero-G training

    NASA Image and Video Library

    1984-07-16

    S84-37536 (18 July 1984) --- Astronaut Robert L. Crippen, left, 41-G crew commander watches as one of his fellow crewmembers gets an introduction to weightlessness aboard a KC-135, "zero-gravity" aircraft. Paul D. Scully-Power is the crew member literally floating here in the brief period of micro-gravity. Scully-Power, an oceanographer with the U.S. Navy, and Marc Garneau (partially visible in chair behind the floating Scully-Power)are payload specialists for 41-G. Garneau represents the National Research Council (Canada).

  15. Measurement of the antineutrino to neutrino charged-current interaction cross section ratio in MINERvA

    NASA Astrophysics Data System (ADS)

    Ren, L.; Aliaga, L.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Cai, T.; Carneiro, M. F.; da Motta, H.; Devan, J.; Dytman, S. A.; Díaz, G. A.; Eberly, B.; Endress, E.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Golan, T.; Gran, R.; Han, J. Y.; Harris, D. A.; Hurtado, K.; Kiveni, M.; Kleykamp, J.; Kordosky, M.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; Martinez Caicedo, D. A.; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman, Paolone, V.; Park, J.; Patrick, C. E.; Perdue, G. N.; Ramírez, M. A.; Ransome, R. D.; Ray, H.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Solano Salinas, C. J.; Sultana, M.; Sánchez Falero, S.; Valencia, E.; Walton, T.; Wolcott, J.; Wospakrik, M.; Yaeggy, B.; MinerνA Collaboration

    2017-04-01

    We present measurements of the neutrino and antineutrino total charged-current cross sections on carbon and their ratio using the MINERvA scintillator-tracker. The measurements span the energy range 2-22 GeV and were performed using forward and reversed horn focusing modes of the Fermilab low-energy NuMI beam to obtain large neutrino and antineutrino samples. The flux is obtained using a subsample of charged-current events at low hadronic energy transfer along with precise higher energy external neutrino cross section data overlapping with our energy range between 12-22 GeV. We also report on the antineutrino-neutrino cross section ratio, RCC , which does not rely on external normalization information. Our ratio measurement, obtained within the same experiment using the same technique, benefits from the cancellation of common sample systematic uncertainties and reaches a precision of ˜5 % at low energy. Our results for the antineutrino-nucleus scattering cross section and for RCC are the most precise to date in the energy range Eν<6 GeV .

  16. Measurement of the antineutrino to neutrino charged-current interaction cross section ratio in MINERvA

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

    Ren, L.; Aliaga, L.; Altinok, O.

    Here, we present measurements of the neutrino and antineutrino total charged-current cross sections on carbon and their ratio using the MINERvA scintillator-tracker. The measurements span the energy range 2-22 GeV and were performed using forward and reversed horn focusing modes of the Fermilab low-energy NuMI beam to obtain large neutrino and antineutrino samples. The flux is obtained using a sub-sample of charged-current events at low hadronic energy transfer along with precise higher energy external neutrino cross section data overlapping with our energy range between 12-22 GeV. We also report on the antineutrino-neutrino cross section ratio, Rcc, which does not rely on external normalization information. Our ratio measurement, obtained within the same experiment using the same technique, benefits from the cancellation of common sample systematic uncertainties and reaches a precision of 5% at low energy. Our results for the antineutrino-nucleus scattering cross section and for Rcc are the most precise to date in the energy rangemore » $$E_{\

  17. Measurement of the antineutrino to neutrino charged-current interaction cross section ratio in MINERvA

    DOE PAGES

    Ren, L.; Aliaga, L.; Altinok, O.; ...

    2017-04-14

    Here, we present measurements of the neutrino and antineutrino total charged-current cross sections on carbon and their ratio using the MINERvA scintillator-tracker. The measurements span the energy range 2-22 GeV and were performed using forward and reversed horn focusing modes of the Fermilab low-energy NuMI beam to obtain large neutrino and antineutrino samples. The flux is obtained using a sub-sample of charged-current events at low hadronic energy transfer along with precise higher energy external neutrino cross section data overlapping with our energy range between 12-22 GeV. We also report on the antineutrino-neutrino cross section ratio, Rcc, which does not rely on external normalization information. Our ratio measurement, obtained within the same experiment using the same technique, benefits from the cancellation of common sample systematic uncertainties and reaches a precision of 5% at low energy. Our results for the antineutrino-nucleus scattering cross section and for Rcc are the most precise to date in the energy rangemore » $$E_{\

  18. CRITICAL EXPERIMENT TANK (CET) REACTOR HAZARDS SUMMARY

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

    Becar, N.J.; Kunze, J.F.; Pincock, G..D.

    1961-03-31

    The Critical Experiment Tank (CET) reactor assembly, the associated systems, and the Low Power Test Facility in which the reactor is to be operated are described. An evaluation and summary of the hazards associated with the operation of the CET reactor in the LPTF at the ldsho Test Station are also presented. (auth)

  19. Experimental physics characteristics of a heavy-metal-reflected fast-spectrum critical assembly

    NASA Technical Reports Server (NTRS)

    Heneveld, W. H.; Paschall, R. K.; Springer, T. H.; Swanson, V. A.; Thiele, A. W.; Tuttle, R. J.

    1971-01-01

    A zero-power critical assembly was designed, constructed, and operated for the purpose of conducting a series of benchmark experiments dealing with the physics characteristics of a UN-fueled, Li-7 cooled, Mo-reflected, drum-controlled compact fast reactor for use with a space-power electric conversion system. The experimental program consisted basically of measuring the differential neutron spectra and the changes in critical mass that accompanied the stepwise addition of (Li-7)3N, Hf, Ta, and W to a basic core fueled with U metal in a pin-type Ta honeycomb structure. In addition, experimental results were obtained on power distributions, control characteristics, neutron lifetime, and reactivity worths of numerous absorber, structural, and scattering materials.

  20. New Whole-House Solutions Case Study: New Town Builders' Power of Zero Energy Center - Denver, Colorado

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

    None

    New Town Builders, a builder of energy efficient homes in Denver, Colorado, offers a zero energy option for all the homes it builds. To attract a wide range of potential homebuyers to its energy efficient homes, New Town Builders created a "Power of Zero Energy Center" linked to its model home in the Stapleton community. This case study presents New Town Builders' marketing approach, which is targeted to appeal to homebuyers' emotions rather than overwhelming homebuyers with scientific details about the technology. The exhibits in the Power of Zero Energy Center focus on reduced energy expenses for the homeowner, improvedmore » occupant comfort, the reputation of the builder, and the lack of sacrificing the homebuyers' desired design features to achieve zero net energy in the home. This case study also contains customer and realtor testimonials related to the effectiveness of the Center in influencing homebuyers to purchase a zero energy home.« less

  1. What's so critical about Critical Neuroscience? Rethinking experiment, enacting critique.

    PubMed

    Fitzgerald, Des; Matusall, Svenja; Skewes, Joshua; Roepstorff, Andreas

    2014-01-01

    In the midst of on-going hype about the power and potency of the new brain sciences, scholars within "Critical Neuroscience" have called for a more nuanced and sceptical neuroscientific knowledge-practice. Drawing especially on the Frankfurt School, they urge neuroscientists towards a more critical approach-one that re-inscribes the objects and practices of neuroscientific knowledge within webs of social, cultural, historical and political-economic contingency. This paper is an attempt to open up the black-box of "critique" within Critical Neuroscience itself. Specifically, we argue that limiting enactments of critique to the invocation of context misses the force of what a highly-stylized and tightly-bound neuroscientific experiment can actually do. We show that, within the neuroscientific experiment itself, the world-excluding and context-denying "rules of the game" may also enact critique, in novel and surprising forms, while remaining formally independent of the workings of society, and culture, and history. To demonstrate this possibility, we analyze the Optimally Interacting Minds (OIM) paradigm, a neuroscientific experiment that used classical psychophysical methods to show that, in some situations, people worked better as a collective, and not as individuals-a claim that works precisely against reactionary tendencies that prioritize individual over collective agency, but that was generated and legitimized entirely within the formal, context-denying conventions of neuroscientific experimentation. At the heart of this paper is a claim that it was precisely the rigors and rules of the experimental game that allowed these scientists to enact some surprisingly critical, and even radical, gestures. We conclude by suggesting that, in the midst of large-scale neuroscientific initiatives, it may be "experiment", and not "context", that forms the meeting-ground between neuro-biological and socio-political research practices.

  2. Future utilization of space: Silverton Conference on material science and phase transformations in zero-gravity, summary of proceeding

    NASA Technical Reports Server (NTRS)

    Eisner, M. (Editor)

    1975-01-01

    The importance of zero gravity environment in the development and production of new and improved materials is considered along with the gravitational effects on phase changes or critical behavior in a variety of materials. Specific experiments discussed include: fine scale phase separation in zero gravity; glass formation in zero gravity; effects of gravitational perturbations on determination of critical exponents; and light scattering from long wave fluctuations in liquids in zero gravity. It is concluded that the space shuttle/spacelab system is applicable to various fields of interest.

  3. Analysis and design of high-power and efficient, millimeter-wave power amplifier systems using zero degree combiners

    NASA Astrophysics Data System (ADS)

    Tai, Wei; Abbasi, Mortez; Ricketts, David S.

    2018-01-01

    We present the analysis and design of high-power millimetre-wave power amplifier (PA) systems using zero-degree combiners (ZDCs). The methodology presented optimises the PA device sizing and the number of combined unit PAs based on device load pull simulations, driver power consumption analysis and loss analysis of the ZDC. Our analysis shows that an optimal number of N-way combined unit PAs leads to the highest power-added efficiency (PAE) for a given output power. To illustrate our design methodology, we designed a 1-W PA system at 45 GHz using a 45 nm silicon-on-insulator process and showed that an 8-way combined PA has the highest PAE that yields simulated output power of 30.6 dBm and 31% peak PAE.

  4. The Ongoing Impact of the U.S. Fast Reactor Integral Experiments Program

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

    John D. Bess; Michael A. Pope; Harold F. McFarlane

    2012-11-01

    The creation of a large database of integral fast reactor physics experiments advanced nuclear science and technology in ways that were unachievable by less capital intensive and operationally challenging approaches. They enabled the compilation of integral physics benchmark data, validated (or not) analytical methods, and provided assurance of future rector designs The integral experiments performed at Argonne National Laboratory (ANL) represent decades of research performed to support fast reactor design and our understanding of neutronics behavior and reactor physics measurements. Experiments began in 1955 with the Zero Power Reactor No. 3 (ZPR-3) and terminated with the Zero Power Physics Reactormore » (ZPPR, originally the Zero Power Plutonium Reactor) in 1990 at the former ANL-West site in Idaho, which is now part of the Idaho National Laboratory (INL). Two additional critical assemblies, ZPR-6 and ZPR-9, operated at the ANL-East site in Illinois. A total of 128 fast reactor assemblies were constructed with these facilities [1]. The infrastructure and measurement capabilities are too expensive to be replicated in the modern era, making the integral database invaluable as the world pushes ahead with development of liquid metal cooled reactors.« less

  5. Thermodynamic analysis of the advanced zero emission power plant

    NASA Astrophysics Data System (ADS)

    Kotowicz, Janusz; Job, Marcin

    2016-03-01

    The paper presents the structure and parameters of advanced zero emission power plant (AZEP). This concept is based on the replacement of the combustion chamber in a gas turbine by the membrane reactor. The reactor has three basic functions: (i) oxygen separation from the air through the membrane, (ii) combustion of the fuel, and (iii) heat transfer to heat the oxygen-depleted air. In the discussed unit hot depleted air is expanded in a turbine and further feeds a bottoming steam cycle (BSC) through the main heat recovery steam generator (HRSG). Flue gas leaving the membrane reactor feeds the second HRSG. The flue gas consist mainly of CO2 and water vapor, thus, CO2 separation involves only the flue gas drying. Results of the thermodynamic analysis of described power plant are presented.

  6. Power Teaching

    ERIC Educational Resources Information Center

    Fluellen, Jerry E., Jr.

    2007-01-01

    Power Teaching weaves four factors into a seamless whole: standards, teaching thinking, research based strategies, and critical inquiry. As a prototype in its first year of development with an urban fifth grade class, the power teaching model connects selected district standards, thinking routines from Harvard University Project Zero Research…

  7. CRITICAL EXPERIMENT WITH BORAX-V. Internal Superheater

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

    Plumlee, K.E.; Baird, Q.L.; Stanford, G.S.

    1963-11-01

    A critical experiment was performed with 12 BORAX-V superheater subassemblies in a central voidable region plus 1228 to 1525 UO/sub 2/ fuel pins (3 wt% enriched) in a peripheral region. Removing water (28% of superheater volume) at room temperature decreased reactivity by 2.2%. The midplane (two- dimensional) peak-to-average power distribution in the voided superheater was approximately 1.24, mostly attributable to flux depressions within insulated fuel boxes. Cadmium ratios are also reported. The experiment was initiated to supplement computational information which might have affected plans for loading the superheater zone into the BORAX-V reactor. No changes were indicated by the experiment.more » (auth)« less

  8. Reactivity-worth estimates of the OSMOSE samples in the MINERVE reactor R1-MOX, R2-UO2 and MORGANE/R configurations.

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

    Zhong, Z.; Klann, R. T.; Nuclear Engineering Division

    2007-08-03

    An initial series of calculations of the reactivity-worth of the OSMOSE samples in the MINERVE reactor with the R2-UO2 and MORGANE/R core configuration were completed. The calculation model was generated using the lattice physics code DRAGON. In addition, an initial comparison of calculated values to experimental measurements was performed based on preliminary results for the R1-MOX configuration.

  9. Critical areas: Satellite power systems concepts

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Critical Areas are defined and discussed in the various areas pertinent to satellite power systems. The presentation is grouped into five areas (General, Space Systems, Solar Energy Conversion, Microwave Systems, and Environment/Ecology) with a sixth area (Power Relay) considered separately in an appendix. Areas for Future Consideration as critical areas are discussed in a second appendix.

  10. High resolution study of magnetic ordering at absolute zero.

    PubMed

    Lee, M; Husmann, A; Rosenbaum, T F; Aeppli, G

    2004-05-07

    High resolution pressure measurements in the zero-temperature limit provide a unique opportunity to study the behavior of strongly interacting, itinerant electrons with coupled spin and charge degrees of freedom. Approaching the precision that has become the hallmark of experiments on classical critical phenomena, we characterize the quantum critical behavior of the model, elemental antiferromagnet chromium, lightly doped with vanadium. We resolve the sharp doubling of the Hall coefficient at the quantum critical point and trace the dominating effects of quantum fluctuations up to surprisingly high temperatures.

  11. Accelerator/Experiment Operations - FY 2015

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

    Czarapata, P.

    2015-10-01

    This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2015. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2015 NOvA, MINOS+ and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the activities in the SciBooNE Hall using the Booster Neutrino Beam (BNB), and the SeaQuest experiment and Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120).

  12. Zero-static power radio-frequency switches based on MoS2 atomristors.

    PubMed

    Kim, Myungsoo; Ge, Ruijing; Wu, Xiaohan; Lan, Xing; Tice, Jesse; Lee, Jack C; Akinwande, Deji

    2018-06-28

    Recently, non-volatile resistance switching or memristor (equivalently, atomristor in atomic layers) effect was discovered in transitional metal dichalcogenides (TMD) vertical devices. Owing to the monolayer-thin transport and high crystalline quality, ON-state resistances below 10 Ω are achievable, making MoS 2 atomristors suitable as energy-efficient radio-frequency (RF) switches. MoS 2 RF switches afford zero-hold voltage, hence, zero-static power dissipation, overcoming the limitation of transistor and mechanical switches. Furthermore, MoS 2 switches are fully electronic and can be integrated on arbitrary substrates unlike phase-change RF switches. High-frequency results reveal that a key figure of merit, the cutoff frequency (f c ), is about 10 THz for sub-μm 2 switches with favorable scaling that can afford f c above 100 THz for nanoscale devices, exceeding the performance of contemporary switches that suffer from an area-invariant scaling. These results indicate a new electronic application of TMDs as non-volatile switches for communication platforms, including mobile systems, low-power internet-of-things, and THz beam steering.

  13. Tribology Experiment in Zero Gravity

    NASA Technical Reports Server (NTRS)

    Pan, C. H. T.; Gause, R. L.; Whitaker, A. F.; Finckenor, M. M.

    2015-01-01

    A tribology experiment in zero gravity was performed during the orbital flight of Spacelab 1 to study the motion of liquid lubricants over solid surfaces. The absence of a significant gravitational force facilitates observation of such motions as controlled by interfacial and capillary forces. Two experimental configurations were used. One deals with the liquid on one solid surface, and the other with the liquid between a pair of closed spaced surfaces. Time sequence photographs of fluid motion on a solid surface yielded spreading rate data of several fluid-surface combinations. In general, a slow spreading process as governed by the tertiary junction can be distinguished from a more rapid process which is driven by surface tension controlled internal fluid pressure. Photographs were also taken through the transparent bushings of several experimental journal bearings. Morphology of incomplete fluid films and its fluctuation with time suggest the presence or absence of unsteady phenomena of the bearing-rotor system in various arrangements.

  14. Benefits, challenges and critical factors of success for Zero Waste: A systematic literature review.

    PubMed

    Pietzsch, Natália; Ribeiro, José Luis Duarte; de Medeiros, Janine Fleith

    2017-09-01

    Considering the growing concern with solid wastes problems and the pressing need for a holistic approach to their management, this study developed a literature review about the subject "Zero Waste". To that end, a systematic literature review was executed, through which 102 published articles were analyzed with the aim to, initially, comprehend the concept of Zero Waste, and, then, map its benefits, challenges, and critical success factors. The results show that scholars have not reached a consensus regarding the concept of ZW. While some studies fully address this philosophy, other studies are based on just one or on some of its topics. The benefits were grouped and organized into four dimensions: benefits to the community, financial-economic benefits, benefits to the environment and benefits to the industry and stakeholders. As to the challenges, barriers were identified both in the macro environment (mainly political and cultural) and in the meso and micro environments (stakeholders, industries, and municipalities). The analysis of the articles enabled listing critical success factors, supported by a set of activities that must be carried out. Regarding future studies, it is worth noting that more empirical studies about ZW implementation are necessary, particularly with regard to educational practices designed to promote changes in user behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. What’s so critical about Critical Neuroscience? Rethinking experiment, enacting critique

    PubMed Central

    Fitzgerald, Des; Matusall, Svenja; Skewes, Joshua; Roepstorff, Andreas

    2014-01-01

    In the midst of on-going hype about the power and potency of the new brain sciences, scholars within “Critical Neuroscience” have called for a more nuanced and sceptical neuroscientific knowledge-practice. Drawing especially on the Frankfurt School, they urge neuroscientists towards a more critical approach—one that re-inscribes the objects and practices of neuroscientific knowledge within webs of social, cultural, historical and political-economic contingency. This paper is an attempt to open up the black-box of “critique” within Critical Neuroscience itself. Specifically, we argue that limiting enactments of critique to the invocation of context misses the force of what a highly-stylized and tightly-bound neuroscientific experiment can actually do. We show that, within the neuroscientific experiment itself, the world-excluding and context-denying “rules of the game” may also enact critique, in novel and surprising forms, while remaining formally independent of the workings of society, and culture, and history. To demonstrate this possibility, we analyze the Optimally Interacting Minds (OIM) paradigm, a neuroscientific experiment that used classical psychophysical methods to show that, in some situations, people worked better as a collective, and not as individuals—a claim that works precisely against reactionary tendencies that prioritize individual over collective agency, but that was generated and legitimized entirely within the formal, context-denying conventions of neuroscientific experimentation. At the heart of this paper is a claim that it was precisely the rigors and rules of the experimental game that allowed these scientists to enact some surprisingly critical, and even radical, gestures. We conclude by suggesting that, in the midst of large-scale neuroscientific initiatives, it may be “experiment”, and not “context”, that forms the meeting-ground between neuro-biological and socio-political research practices. PMID:24910605

  16. Adaptive critic designs for discrete-time zero-sum games with application to H(infinity) control.

    PubMed

    Al-Tamimi, Asma; Abu-Khalaf, Murad; Lewis, Frank L

    2007-02-01

    In this correspondence, adaptive critic approximate dynamic programming designs are derived to solve the discrete-time zero-sum game in which the state and action spaces are continuous. This results in a forward-in-time reinforcement learning algorithm that converges to the Nash equilibrium of the corresponding zero-sum game. The results in this correspondence can be thought of as a way to solve the Riccati equation of the well-known discrete-time H(infinity) optimal control problem forward in time. Two schemes are presented, namely: 1) a heuristic dynamic programming and 2) a dual-heuristic dynamic programming, to solve for the value function and the costate of the game, respectively. An H(infinity) autopilot design for an F-16 aircraft is presented to illustrate the results.

  17. Accelerator/Experiment Operations - FY 2014

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

    Czarapata, P.; Geer, S.; Geesaman, D.

    2014-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2014. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2014 MINOS and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the MiniBooNE experiment running in the Booster Neutrino Beam (BNB), and the SeaQuest experiment and Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120). Each section was prepared by the relevant authors, and was somewhat edited for inclusion in this summary.

  18. Possibility of exchange of a rectilinear three-body system with zero energy

    NASA Astrophysics Data System (ADS)

    Koda, Eiji

    The possibility of exchange for a rectilinear three-body system with zero energy is examined by introducing regularized coordinates which are closely related to McGehee's (1974) coordinates. It is shown that all of the HE(-)-HE(+) orbits are of exchange type in a critical system whose orbits of parabolic-parabolic escape type experience odd times of binary collision. No exchange occurs in critical systems whose orbits of parabolic-parabolic escape type experience even times of binary collision.

  19. Zero-Gravity Atmospheric Cloud Physics Experiment Laboratory engineering concepts/design tradeoffs. Volume 1: Study results

    NASA Technical Reports Server (NTRS)

    Greco, R. V.; Eaton, L. R.; Wilkinson, H. C.

    1974-01-01

    The work is summarized which was accomplished from January 1974 to October 1974 for the Zero-Gravity Atmospheric Cloud Physics Laboratory. The definition and development of an atmospheric cloud physics laboratory and the selection and delineation of candidate experiments that require the unique environment of zero gravity or near zero gravity are reported. The experiment program and the laboratory concept for a Spacelab payload to perform cloud microphysics research are defined. This multimission laboratory is planned to be available to the entire scientific community to utilize in furthering the basic understanding of cloud microphysical processes and phenomenon, thereby contributing to improved weather prediction and ultimately to provide beneficial weather control and modification.

  20. Temporal Characteristics of the Sleep EEG Power Spectrum in Critically Ill Children

    PubMed Central

    Kudchadkar, Sapna R.; Yaster, Myron; Punjabi, Arjun N.; Quan, Stuart F.; Goodwin, James L.; Easley, R. Blaine; Punjabi, Naresh M.

    2015-01-01

    Study Objectives: Although empirical evidence is limited, critical illness in children is associated with disruption of the normal sleep-wake rhythm. The objective of the current study was to examine the temporal characteristics of the sleep electroencephalogram (EEG) in a sample of children with critical illness. Methods: Limited montage EEG recordings were collected for at least 24 hours from 8 critically ill children on mechanical ventilation for respiratory failure in a pediatric intensive care unit (PICU) of a tertiary-care hospital. Each PICU patient was age- and gender-matched to a healthy subject from the community. Power spectral analysis with the fast Fourier transform (FFT) was used to characterize EEG spectral power and categorized into 4 frequency bands: δ (0.8 to 4.0 Hz), θ (4.1 to 8.0 Hz), α (8.1 to 13.0 Hz), and β1/β2 (13.1 to 20.0 Hz). Results: PICU patients did not manifest the ultradian variability in EEG power spectra including the typical increase in δ-power during the first third of the night that was observed in healthy children. Differences noted included significantly lower mean nighttime δ and θ power in the PICU patients compared to healthy children (p < 0.001). Moreover, in the PICU patients, mean δ and θ power were higher during daytime hours than nighttime hours (p < 0.001). Conclusions: The results presented herein challenge the assumption that children experience restorative sleep during critical illness, highlighting the need for interventional studies to determine whether sleep promotion improves outcomes in critically ill children undergoing active neurocognitive development. Citation: Kudchadkar SR, Yaster M, Punjabi AN, Quan SF, Goodwin JL, Easley RB, Punjabi NM. Temporal characteristics of the sleep EEG power spectrum in critically ill children. J Clin Sleep Med 2015;11(12):1449–1454. PMID:26194730

  1. Measurement of Neutral-Current K+ Production by Neutrinos using MINERvA

    NASA Astrophysics Data System (ADS)

    Marshall, C. M.; Aliaga, L.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Cai, T.; Carneiro, M. F.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Dunkman, M.; Eberly, B.; Endress, E.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Golan, T.; Gran, R.; Harris, D. A.; Higuera, A.; Hurtado, K.; Kleykamp, J.; Kordosky, M.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Caicedo, D. A. Martinez; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman; Paolone, V.; Patrick, C. E.; Perdue, G. N.; Ramírez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schmitz, D. W.; Solano Salinas, C. J.; Sultana, M.; Sánchez Falero, S.; Valencia, E.; Walton, T.; Wolcott, J.; Wospakrik, M.; Yaeggy, B.; Zhang, D.; Minerva Collaboration

    2017-07-01

    Neutral-current production of K+ by atmospheric neutrinos is a background in searches for the proton decay p →K+ν ¯. Reactions such as ν p →ν K+Λ are indistinguishable from proton decays when the decay products of the Λ are below detection threshold. Events with K+ are identified in MINERvA by reconstructing the timing signature of a K+ decay at rest. A sample of 201 neutrino-induced neutral-current K+ events is used to measure differential cross sections with respect to the K+ kinetic energy, and the non-K+ hadronic visible energy. An excess of events at low hadronic visible energy is observed relative to the prediction of the neut event generator. Good agreement is observed with the cross section prediction of the genie generator. A search for photons from π0 decay, which would veto a neutral-current K+ event in a proton decay search, is performed, and a 2 σ deficit of detached photons is observed relative to the genie prediction.

  2. Measurement of Neutral-Current K + Production by Neutrinos using MINERvA

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

    Marshall, C. M.; Aliaga, L.; Altinok, O.

    Neutral-current production of K+ by atmospheric neutrinos is a background in searches for the proton decay p→K+ν¯. Reactions such as νp→νK+Λ are indistinguishable from proton decays when the decay products of the Λ are below detection threshold. Events with K+ are identified in MINERvA by reconstructing the timing signature of a K+ decay at rest. A sample of 201 neutrino-induced neutral-current K+ events is used to measure differential cross sections with respect to the K+ kinetic energy, and the non-K+ hadronic visible energy. An excess of events at low hadronic visible energy is observed relative to the prediction of themore » neut event generator. Good agreement is observed with the cross section prediction of the genie generator. A search for photons from π0 decay, which would veto a neutral-current K+ event in a proton decay search, is performed, and a 2σ deficit of detached photons is observed relative to the genie prediction.« less

  3. Measurement of Neutral-Current K + Production by Neutrinos using MINERvA

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

    Marshall, C. M.; Aliaga, L.; Altinok, O.

    Neutral-current production of K + by atmospheric neutrinos is a background in searches for the proton decay p → K +ν¯. Reactions such as νp → νK +Λ are indistinguishable from proton decays when the decay products of the Λ are below detection threshold. Events with K + are identified in MINERvA by reconstructing the timing signature of a K + decay at rest. A sample of 201 neutrino-induced neutral-current K + events is used to measure differential cross sections with respect to the K + kinetic energy, and the non-K + hadronic visible energy. An excess of events atmore » low hadronic visible energy is observed relative to the prediction of the neut event generator. Good agreement is observed with the cross section prediction of the genie generator. In conclusion, a search for photons from π 0 decay, which would veto a neutral-current K + event in a proton decay search, is performed, and a 2σ deficit of detached photons is observed relative to the genie prediction.« less

  4. Measurement of Neutral-Current K + Production by Neutrinos using MINERvA

    DOE PAGES

    Marshall, C. M.; Aliaga, L.; Altinok, O.; ...

    2017-07-07

    Neutral-current production of K + by atmospheric neutrinos is a background in searches for the proton decay p → K +ν¯. Reactions such as νp → νK +Λ are indistinguishable from proton decays when the decay products of the Λ are below detection threshold. Events with K + are identified in MINERvA by reconstructing the timing signature of a K + decay at rest. A sample of 201 neutrino-induced neutral-current K + events is used to measure differential cross sections with respect to the K + kinetic energy, and the non-K + hadronic visible energy. An excess of events atmore » low hadronic visible energy is observed relative to the prediction of the neut event generator. Good agreement is observed with the cross section prediction of the genie generator. In conclusion, a search for photons from π 0 decay, which would veto a neutral-current K + event in a proton decay search, is performed, and a 2σ deficit of detached photons is observed relative to the genie prediction.« less

  5. A maximally selected test of symmetry about zero.

    PubMed

    Laska, Eugene; Meisner, Morris; Wanderling, Joseph

    2012-11-20

    The problem of testing symmetry about zero has a long and rich history in the statistical literature. We introduce a new test that sequentially discards observations whose absolute value is below increasing thresholds defined by the data. McNemar's statistic is obtained at each threshold and the largest is used as the test statistic. We obtain the exact distribution of this maximally selected McNemar and provide tables of critical values and a program for computing p-values. Power is compared with the t-test, the Wilcoxon Signed Rank Test and the Sign Test. The new test, MM, is slightly less powerful than the t-test and Wilcoxon Signed Rank Test for symmetric normal distributions with nonzero medians and substantially more powerful than all three tests for asymmetric mixtures of normal random variables with or without zero medians. The motivation for this test derives from the need to appraise the safety profile of new medications. If pre and post safety measures are obtained, then under the null hypothesis, the variables are exchangeable and the distribution of their difference is symmetric about a zero median. Large pre-post differences are the major concern of a safety assessment. The discarded small observations are not particularly relevant to safety and can reduce power to detect important asymmetry. The new test was utilized on data from an on-road driving study performed to determine if a hypnotic, a drug used to promote sleep, has next day residual effects. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Zero-field quantum critical point in Ce0.91Yb0.09CoIn5

    NASA Astrophysics Data System (ADS)

    Singh, Y. P.; Adhikari, R. B.; Haney, D. J.; White, B. D.; Maple, M. B.; Dzero, M.; Almasan, C. C.

    2018-05-01

    We present results of specific heat, electrical resistance, and magnetoresistivity measurements on single crystals of the heavy-fermion superconducting alloy Ce0.91Yb0.09CoIn5 . Non-Fermi-liquid to Fermi-liquid crossovers are clearly observed in the temperature dependence of the Sommerfeld coefficient γ and resistivity data. Furthermore, we show that the Yb-doped sample with x =0.09 exhibits universality due to an underlying quantum phase transition without an applied magnetic field by utilizing the scaling analysis of γ . Fitting of the heat capacity and resistivity data based on existing theoretical models indicates that the zero-field quantum critical point is of antiferromagnetic origin. Finally, we found that at zero magnetic field the system undergoes a third-order phase transition at the temperature Tc 3≈7 K.

  7. Microscopic Engine Powered by Critical Demixing

    NASA Astrophysics Data System (ADS)

    Schmidt, Falko; Magazzù, Alessandro; Callegari, Agnese; Biancofiore, Luca; Cichos, Frank; Volpe, Giovanni

    2018-02-01

    We experimentally demonstrate a microscopic engine powered by the local reversible demixing of a critical mixture. We show that, when an absorbing microsphere is optically trapped by a focused laser beam in a subcritical mixture, it is set into rotation around the optical axis of the beam because of the emergence of diffusiophoretic propulsion. This behavior can be controlled by adjusting the optical power, the temperature, and the criticality of the mixture.

  8. Scientific Objectives of the Critical Viscosity Experiment

    NASA Technical Reports Server (NTRS)

    Berg, R. F.; Moldover, M. R.

    1993-01-01

    In microgravity, the Critical Viscosity Experiment will measure the viscosity of xenon 15 times closer to the critical point than is possible on earth. The results are expected to include the first direct observation of the predicted power-law divergence of viscosity in a pure fluid and they will test calculations of the value of the exponent associated with the divergence. The results, when combined with Zeno's decay-rate data, will strengthen the test of mode coupling theory. Without microgravity viscosity data, the Zeno test will require an extrapolation of existing 1-g viscosity data by as much as factor of 100 in reduced temperature. By necessity, the extrapolation would use an incompletely verified theory of viscosity crossover. With the microgravity viscosity data, the reliance on crossover models will be negligible allowing a more reliable extrapolation. During the past year, new theoretical calculations for the viscosity exponent finally achieved consistency with the best experimental data for pure fluids. This report gives the justification for the proposed microgravity Critical Viscosity Experiment in this new context. This report also combines for the first time the best available light scattering data with our recent viscosity data to demonstrate the current status of tests of mode coupling theory.

  9. Measurement of νμ charged-current single π0 production on hydrocarbon in the few-GeV region using MINERvA

    NASA Astrophysics Data System (ADS)

    Altinok, O.; Le, T.; Aliaga, L.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Caceres Vera, G. F. R.; Cai, T.; Carneiro, M. F.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Gran, R.; Han, J. Y.; Harris, D. A.; Kleykamp, J.; Kordosky, M.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; Martinez Caicedo, D. A.; McFarland, K. S.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman, Paolone, V.; Patrick, C. E.; Perdue, G. N.; Ramirez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Sobczyk, J. T.; Solano Salinas, C. J.; Sultana, M.; Sánchez Falero, S.; Valencia, E.; Wolcott, J.; Yaeggy, B.

    2017-10-01

    The semiexclusive channel νμ+CH →μ-π0+nucleon(s ) is analyzed using MINERvA exposed to the low-energy NuMI νμ beam with spectral peak at Eν≃3 GeV . Differential cross sections for muon momentum and production angle, π0 kinetic energy and production angle, and for squared four-momentum transfer are reported, and the cross section σ (Eν) is obtained over the range 1.5 GeV ≤Eν<20 GeV . Results are compared to GENIE and NuWro predictions and to published MINERvA cross sections for charged-current π+(π0) production by νμ(ν¯μ) neutrinos. Disagreements between data and simulation are observed at very low and relatively high values for muon angle and for Q2 that may reflect shortfalls in modeling of interactions on carbon. For π0 kinematic distributions, however, the data are consistent with the simulation and provide support for generator treatments of pion intranuclear scattering. Using signal-event subsamples that have reconstructed protons as well as π0 mesons, the p π0 invariant mass distribution is obtained, and the decay polar and azimuthal angle distributions in the rest frame of the p π0 system are measured in the region of Δ (1232 )+ production, W <1.4 GeV .

  10. Measurement of ν μ charged-current single π 0 production on hydrocarbon in the few-GeV region using MINERvA

    DOE PAGES

    Altinok, O.; Le, T.; Aliaga, L.; ...

    2017-10-01

    The semiexclusive channel νμ+CH→μ-π0+nucleon(s) is analyzed using MINERvA exposed to the low-energy NuMI νμ beam with spectral peak at Eν≃3 GeV. Differential cross sections for muon momentum and production angle, π0 kinetic energy and production angle, and for squared four-momentum transfer are reported, and the cross section σ(Eν) is obtained over the range 1.5 GeV≤Eν<20 GeV. Results are compared to GENIE and NuWro predictions and to published MINERvA cross sections for charged-current π+(π0) production by νμ(ν¯μ) neutrinos. Disagreements between data and simulation are observed at very low and relatively high values for muon angle and for Q2 that may reflectmore » shortfalls in modeling of interactions on carbon. For π0 kinematic distributions, however, the data are consistent with the simulation and provide support for generator treatments of pion intranuclear scattering. Using signal-event subsamples that have reconstructed protons as well as π0 mesons, the pπ0 invariant mass distribution is obtained, and the decay polar and azimuthal angle distributions in the rest frame of the pπ0 system are measured in the region of Δ(1232)+ production, W<1.4 GeV.« less

  11. Measurement of ν μ charged-current single π 0 production on hydrocarbon in the few-GeV region using MINERvA

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

    Altinok, O.; Le, T.; Aliaga, L.

    The semiexclusive channel νμ+CH→μ-π0+nucleon(s) is analyzed using MINERvA exposed to the low-energy NuMI νμ beam with spectral peak at Eν≃3 GeV. Differential cross sections for muon momentum and production angle, π0 kinetic energy and production angle, and for squared four-momentum transfer are reported, and the cross section σ(Eν) is obtained over the range 1.5 GeV≤Eν<20 GeV. Results are compared to GENIE and NuWro predictions and to published MINERvA cross sections for charged-current π+(π0) production by νμ(ν¯μ) neutrinos. Disagreements between data and simulation are observed at very low and relatively high values for muon angle and for Q2 that may reflectmore » shortfalls in modeling of interactions on carbon. For π0 kinematic distributions, however, the data are consistent with the simulation and provide support for generator treatments of pion intranuclear scattering. Using signal-event subsamples that have reconstructed protons as well as π0 mesons, the pπ0 invariant mass distribution is obtained, and the decay polar and azimuthal angle distributions in the rest frame of the pπ0 system are measured in the region of Δ(1232)+ production, W<1.4 GeV.« less

  12. Power and action in critical theory across disciplines: implications for critical community psychology.

    PubMed

    Davidson, Heather; Evans, Scot; Ganote, Cynthia; Henrickson, Jorie; Jacobs-Priebe, Lynette; Jones, Diana L; Prilleltensky, Isaac; Riemer, Manuel

    2006-09-01

    Although critical scholarship and community psychology share similar aspirations, the links between them remain unexplored and under-theorized. In this article we explore the implications of critical scholarship in various specialties for the field of community psychology. To understand the contributions of critical scholarship to a theory of power and action for social change, we conducted a systematic analysis of a ten-year period of publications in seven journals associated with the critical scholarship tradition. We created precise criteria for the concepts of power and action and applied them to the publications. Results indicate an interesting paradox at play. Whereas community psychology is more action oriented than critical scholarship, its actions fall short of challenging institutionalized power structures and the status quo; and whereas critical scholarship is more challenging of the status quo than community psychology in theory, it has failed to produce viable actions that challenge the status quo. We discuss the implications of this state of affairs for the development of a more critical community psychology.

  13. Temporal Characteristics of the Sleep EEG Power Spectrum in Critically Ill Children.

    PubMed

    Kudchadkar, Sapna R; Yaster, Myron; Punjabi, Arjun N; Quan, Stuart F; Goodwin, James L; Easley, R Blaine; Punjabi, Naresh M

    2015-12-15

    Although empirical evidence is limited, critical illness in children is associated with disruption of the normal sleep-wake rhythm. The objective of the current study was to examine the temporal characteristics of the sleep electroencephalogram (EEG) in a sample of children with critical illness. Limited montage EEG recordings were collected for at least 24 hours from 8 critically ill children on mechanical ventilation for respiratory failure in a pediatric intensive care unit (PICU) of a tertiary-care hospital. Each PICU patient was age- and gender-matched to a healthy subject from the community. Power spectral analysis with the fast Fourier transform (FFT) was used to characterize EEG spectral power and categorized into 4 frequency bands: δ (0.8 to 4.0 Hz), θ (4.1 to 8.0 Hz), α (8.1 to 13.0 Hz), and β1/β2 (13.1 to 20.0 Hz). PICU patients did not manifest the ultradian variability in EEG power spectra including the typical increase in δ-power during the first third of the night that was observed in healthy children. Differences noted included significantly lower mean nighttime δ and θ power in the PICU patients compared to healthy children (p < 0.001). Moreover, in the PICU patients, mean δ and θ power were higher during daytime hours than nighttime hours (p < 0.001). The results presented herein challenge the assumption that children experience restorative sleep during critical illness, highlighting the need for interventional studies to determine whether sleep promotion improves outcomes in critically ill children undergoing active neurocognitive development. © 2015 American Academy of Sleep Medicine.

  14. Power-Stepped HF Cross-Modulation Experiments: Simulations and Experimental Observations

    NASA Astrophysics Data System (ADS)

    Greene, S.; Moore, R. C.

    2014-12-01

    High frequency (HF) cross modulation experiments are a well established means for probing the HF-modified characteristics of the D-region ionosphere. The interaction between the heating wave and the probing pulse depends on the ambient and modified conditions of the D-region ionosphere. Cross-modulation observations are employed as a measure of the HF-modified refractive index. We employ an optimized version of Fejer's method that we developed during previous experiments. Experiments were performed in March 2013 at the High Frequency Active Auroral Research Program (HAARP) observatory in Gakona, Alaska. During these experiments, the power of the HF heating signal incrementally increased in order to determine the dependence of cross-modulation on HF power. We found that a simple power law relationship does not hold at high power levels, similar to previous ELF/VLF wave generation experiments. In this paper, we critically compare these experimental observations with the predictions of a numerical ionospheric HF heating model and demonstrate close agreement.

  15. Experimental Design and Power Calculation for RNA-seq Experiments.

    PubMed

    Wu, Zhijin; Wu, Hao

    2016-01-01

    Power calculation is a critical component of RNA-seq experimental design. The flexibility of RNA-seq experiment and the wide dynamic range of transcription it measures make it an attractive technology for whole transcriptome analysis. These features, in addition to the high dimensionality of RNA-seq data, bring complexity in experimental design, making an analytical power calculation no longer realistic. In this chapter we review the major factors that influence the statistical power of detecting differential expression, and give examples of power assessment using the R package PROPER.

  16. Variable speed wind turbine generator with zero-sequence filter

    DOEpatents

    Muljadi, Eduard

    1998-01-01

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

  17. Variable Speed Wind Turbine Generator with Zero-sequence Filter

    DOEpatents

    Muljadi, Eduard

    1998-08-25

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

  18. Variable speed wind turbine generator with zero-sequence filter

    DOEpatents

    Muljadi, E.

    1998-08-25

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility. 14 figs.

  19. Science Requirements for a Space Flight Experiment Entitled Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    Berg, Robert F.; Moldover, Michael R.

    1993-01-01

    We propose to measure in low gravity the viscosity of xenon close to its critical point. The accuracy will be sufficient to eliminate uncertainties currently associated with the analysis of l-g experiments. The measurements will provide the first direct observation of the predicted power-law divergence of viscosity in a pure fluid. The measurements will also strengthen Zeno's test of mode coupling theory by greatly increasing the reliability of the extrapolation of viscosity to low reduced temperatures. Our scientific objectives are described in more detail in one of the attached reports. The low-gravity experiment will be the final stage of a program whose completed ground-based stages are: (1) theoretical studies by one of the principal investigators (MRM) and coworkers, (2) critical viscosity measurements of binary liquid mixtures, (3) critical viscosity measurements of pure fluids in l-g, and development of a suitable vibration-insensitive viscometer. Our technical approach is described in the draft Science Requirements Document. One of us (MRM) has reviewed opportunities for critical phenomena research in low gravity. Both of us were co-principal investigators in the Thermal Equilibration Experiment in the Critical Point Facility, flown on IML-1 in 1992. From this experience, and from the technical maturity of our ground-based work, we believe our critical point viscometer is ready for development as a flight experiment.

  20. An Active Micro Vibration Isolator with Zero-Power Controlled Magnetic Suspension Technology

    NASA Astrophysics Data System (ADS)

    Hoque, Md. Emdadul; Takasaki, Masaya; Ishino, Yuji; Suzuki, Hirohisa; Mizuno, Takeshi

    In this paper, a three-degree-of-freedom vibration isolation system using active zero-power controlled magnetic suspension is presented in order to isolate vibrations transmitted from the ground and to attenuate the effect of direct disturbances on the table. The zero-compliance of the isolator for direct disturbances was realized by connecting a conventional mechanical spring in series with a negative spring produced by an active magnetic suspension mechanism. In this work, each degree-of-freedom-of-motion of the vibration isolator is treated analytically and it is shown that the developed system is capable to generate infinite stiffness in each mode. Experimental studies have been conducted as well to measure the effectiveness of the isolator under both types of disturbances. Further improvements for the developed system as well as the control techniques are also discussed.

  1. Lens Systems Incorporating A Zero Power Corrector Objectives And Magnifiers For Night Vision Applications

    NASA Astrophysics Data System (ADS)

    McDowell, M. W.; Klee, H. W.

    1986-02-01

    The use of the zero power corrector concept has been extended to the design of objective lenses and magnifiers suitable for use in night vision goggles. A novel design which can be used as either an f/1.2 objective or an f/2 magnifier is also described.

  2. Lens Systems Incorporating A Zero Power Corrector Part 3 New Four-Element Microscope Objectives With Flat Field Or High Power

    NASA Astrophysics Data System (ADS)

    Klee, H. W.; McDowell, M. W.

    1986-02-01

    The use of the zero power corrector concept has been extended to the design of microscope objectives. Several four and five-element designs are described which include a flat field 10x design of 0.25 numerical aperture and a 40x design of 0.65 numerical aperture.

  3. ZERO-G - Crippen, Robert L.

    NASA Image and Video Library

    1979-04-03

    Zero-gravity experiments in KC-135 conducted by John Young, Robert L. Crippen, Joseph Kerwin, and Margaret Seddon. 1. Kerwin, Joseph - Zero-G 2. Seddon, Margaret - Zero-G 3. Young, John - Zero-G 4. Aircraft - KC-135

  4. ZERO TO THREE Critical Competencies for Infant-Toddler Educators™ ... in Brief

    ERIC Educational Resources Information Center

    ZERO TO THREE, 2016

    2016-01-01

    Early experiences matter. The quality of the early care and education provided to young children not only impacts their experiences now, but directly contributes to their future success in school and in life. High-quality early learning experiences require effective educators but attainment and application of these critical knowledge and skills is…

  5. Accelerator/Experiment Operations - FY 2016

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

    Blake, A.; Convery, M.; Geer, S.

    2016-10-01

    This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2016. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2016 NOvA, MINOS+ and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the MicroBooNE experiment and the activities in the SciBooNE Hall using the Booster Neutrino Beam (BNB), and the SeaQuest experiment, LArIAT experiment and Meson Test Beam activities in the 120 GeV external switchyard beam (SY120). Each section was prepared by the relevant authors, and was then edited for inclusion inmore » this summary.« less

  6. Micro and Nano Electromechanical Systems for Near-Zero Power Infrared Detection

    NASA Astrophysics Data System (ADS)

    Qian, Zhenyun

    Light is one of the most important tools for human beings to probe and sense the physical world. Infrared (IR) radiation located in longer wavelengths than those of visible light carries rich information of an environment as it reveals the temperature distribution and chemical composition of objects. In addition, it has been utilized for communication and distance measurement owing to the atmospheric window and insensitiveness of human eyes to the IR radiation. As a result, IR detectors nowadays can be found in a wide variety of applications, including thermal imaging, automotive night vision, standoff chemical detection, remote control and laser ranging, just to mention a few. On the other hand, due to the recent fast development of the Internet of Things (IoT), there is a growing demand for miniaturized and power efficient unattended sensors that can be widely distributed in large volumes to form a wireless sensor networks capable of monitoring the environment with high accuracy and long lifetime. In this context, micro and nano electromechanical systems (MEMS/NEMS) may provide a huge impact, since they can be used for the implementation of miniaturized, low power, high-performance sensors and wireless communication devices fully compatible with standard integrated circuitry. This dissertation presents the design and the experimental verification of high performance uncooled IR detectors based on Aluminum Nitride (AlN) nano electromechanical resonators, and a first-of-its-kind near-zero power IR digitizer based on plasmonically-enhanced micromechanical photoswitches. The unique advantages of the piezoelectric AlN thin film in terms of scaling in thickness and transduction efficiency are exploited by the first experimental demonstration of ultra-fast (thermal time constant, tau ˜ 80 mus) and high resolution (noise equivalent power, NEP ˜ 656 pW/Hz1/2) AlN NEMS resonant IR detectors with reduced pixel size comparable to the state-of-the-art microbolometers

  7. Modelling decremental ramps using 2- and 3-parameter "critical power" models.

    PubMed

    Morton, R Hugh; Billat, Veronique

    2013-01-01

    The "Critical Power" (CP) model of human bioenergetics provides a valuable way to identify both limits of tolerance to exercise and mechanisms that underpin that tolerance. It applies principally to cycling-based exercise, but with suitable adjustments for analogous units it can be applied to other exercise modalities; in particular to incremental ramp exercise. It has not yet been applied to decremental ramps which put heavy early demand on the anaerobic energy supply system. This paper details cycling-based bioenergetics of decremental ramps using 2- and 3-parameter CP models. It derives equations that, for an individual of known CP model parameters, define those combinations of starting intensity and decremental gradient which will or will not lead to exhaustion before ramping to zero; and equations that predict time to exhaustion on those decremental ramps that will. These are further detailed with suitably chosen numerical and graphical illustrations. These equations can be used for parameter estimation from collected data, or to make predictions when parameters are known.

  8. State-plane analysis of zero-voltage-switching resonant dc/dc power converters

    NASA Astrophysics Data System (ADS)

    Kazimierczuk, Marian K.; Morse, William D.

    The state-plane analysis technique for the zero-voltage-switching resonant dc/dc power converter family of topologies, namely the buck, boost, buck-boost, and Cuk converters is established. The state plane provides a compression of information that allows the designer to uniquely examine the nonlinear dynamics of resonant converter operation. Utilizing the state plane, resonant converter modes of operation are examined and the switching frequencies are derived for the boundaries between these modes, including the boundary of energy conversion.

  9. MC21 analysis of the MIT PWR benchmark: Hot zero power results

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

    Kelly Iii, D. J.; Aviles, B. N.; Herman, B. R.

    2013-07-01

    MC21 Monte Carlo results have been compared with hot zero power measurements from an operating pressurized water reactor (PWR), as specified in a new full core PWR performance benchmark from the MIT Computational Reactor Physics Group. Included in the comparisons are axially integrated full core detector measurements, axial detector profiles, control rod bank worths, and temperature coefficients. Power depressions from grid spacers are seen clearly in the MC21 results. Application of Coarse Mesh Finite Difference (CMFD) acceleration within MC21 has been accomplished, resulting in a significant reduction of inactive batches necessary to converge the fission source. CMFD acceleration has alsomore » been shown to work seamlessly with the Uniform Fission Site (UFS) variance reduction method. (authors)« less

  10. Zero Thermal Noise in Resistors at Zero Temperature

    NASA Astrophysics Data System (ADS)

    Kish, Laszlo B.; Niklasson, Gunnar A.; Granqvist, Claes-Göran

    2016-06-01

    The bandwidth of transistors in logic devices approaches the quantum limit, where Johnson noise and associated error rates are supposed to be strongly enhanced. However, the related theory — asserting a temperature-independent quantum zero-point (ZP) contribution to Johnson noise, which dominates the quantum regime — is controversial and resolution of the controversy is essential to determine the real error rate and fundamental energy dissipation limits of logic gates in the quantum limit. The Callen-Welton formula (fluctuation-dissipation theorem) of voltage and current noise for a resistance is the sum of Nyquist’s classical Johnson noise equation and a quantum ZP term with a power density spectrum proportional to frequency and independent of temperature. The classical Johnson-Nyquist formula vanishes at the approach of zero temperature, but the quantum ZP term still predicts non-zero noise voltage and current. Here, we show that this noise cannot be reconciled with the Fermi-Dirac distribution, which defines the thermodynamics of electrons according to quantum-statistical physics. Consequently, Johnson noise must be nil at zero temperature, and non-zero noise found for certain experimental arrangements may be a measurement artifact, such as the one mentioned in Kleen’s uncertainty relation argument.

  11. The Relationship between Teachers' and Principals' Decision-Making Power: Is It a Win-Win Situation or a Zero-Sum Game?

    ERIC Educational Resources Information Center

    Shen, Jianping; Xia, Jiangang

    2012-01-01

    Is the power relationship between public school teachers and principals a win-win situation or a zero-sum game? By applying hierarchical linear modeling to the 1999-2000 nationally representative Schools and Staffing Survey data, we found that both the win-win and zero-sum-game theories had empirical evidence. The decision-making areas…

  12. Flare cue symbology and EVS for zero-zero weather landing

    NASA Astrophysics Data System (ADS)

    French, Guy A.; Murphy, David M.; Ercoline, William R.

    2006-05-01

    When flying an airplane, landing is arguably the most difficult task a pilot can do. This applies to pilots of all skill levels particularly as the level of complexity in both the aircraft and environment increase. Current navigational aids, such as an instrument landing system (ILS), do a good job of providing safe guidance for an approach to an airfield. These aids provide data to primary flight reference (PFR) displays on-board the aircraft depicting through symbology what the pilot's eyes should be seeing. Piloting an approach under visual meteorological conditions (VMC) is relatively easy compared to the various complex instrument approaches under instrument meteorological conditions (IMC) which may include flying in zero-zero weather. Perhaps the most critical point in the approach is the transition to landing where the rate of closure between the wheels and the runway is critical to a smooth, accurate landing. Very few PFR's provide this flare cue information. In this study we will evaluate examples of flare cueing symbology for use in landing an aircraft in the most difficult conditions. This research is a part of a larger demonstration effort using sensor technology to land in zero-zero weather at airfields that offer no or unreliable approach guidance. Several problems exist when landing without visual reference to the outside world. One is landing with a force greater than desired at touchdown and another is landing on a point of the runway other than desired. We compare different flare cueing systems to one another and against a baseline for completing this complex approach task.

  13. Absolute Zero.

    ERIC Educational Resources Information Center

    Jones, Rebecca

    1997-01-01

    So far the courts have supported most schools' zero-tolerance policies--even those banning toy weapons, over-the-counter drugs, and unseemly conduct. However, wide-ranging get-tough policies can draw criticism. Policy experts advise school boards to ask the community, decide what people want, allow some wiggle room, create an appeals process,…

  14. Analysis of a boron-carbide-drum-controlled critical reactor experiment

    NASA Technical Reports Server (NTRS)

    Mayo, W. T.

    1972-01-01

    In order to validate methods and cross sections used in the neutronic design of compact fast-spectrum reactors for generating electric power in space, an analysis of a boron-carbide-drum-controlled critical reactor was made. For this reactor the transport analysis gave generally satisfactory results. The calculated multiplication factor for the most detailed calculation was only 0.7-percent Delta k too high. Calculated reactivity worth of the control drums was $11.61 compared to measurements of $11.58 by the inverse kinetics methods and $11.98 by the inverse counting method. Calculated radial and axial power distributions were in good agreement with experiment.

  15. Zeno: Critical Fluid Light Scattering Experiment

    NASA Technical Reports Server (NTRS)

    Gammon, Robert W.; Shaumeyer, J. N.; Briggs, Matthew E.; Boukari, Hacene; Gent, David A.; Wilkinson, R. Allen

    1996-01-01

    The Zeno (Critical Fluid Light Scattering) experiment is the culmination of a long history of critical fluid light scattering in liquid-vapor systems. The major limitation to making accurate measurements closer to the critical point was the density stratification which occurs in these extremely compressible fluids. Zeno was to determine the critical density fluctuation decay rates at a pair of supplementary angles in the temperature range 100 mK to 100 (mu)K from T(sub c) in a sample of xenon accurately loaded to the critical density. This paper gives some highlights from operating the instrument on two flights March, 1994 on STS-62 and February, 1996 on STS-75. More detail of the experiment Science Requirements, the personnel, apparatus, and results are displayed on the Web homepage at http://www.zeno.umd.edu.

  16. Holding Firm: Power, Push-Back, and Opportunities in Navigating the Liminal Space of Critical Qualitative Health Research.

    PubMed

    Hart, Corinne; Poole, Jennifer M; Facey, Marcia E; Parsons, Janet A

    2017-10-01

    Critical qualitative health researchers typically occupy and navigate liminal academic spaces and statuses, with one foot planted in the arts and social sciences and the other in biomedical science. We are at once marginalized and empowered, and this liminality presents both challenges and opportunities. In this article, we draw on our experiences of being (often the lone) critical qualitative health scholars on thesis advisory committees and dissertation examinations, as well as our experiences of publishing and securing funding, to illuminate how power and knowledge relations create conditions that shape the nature of our roles. We share strategies we have developed for standing our theoretical and methodological ground. We discuss how we use the power of our liminality to hold firm, push back, and push forward, to ensure that critical qualitative research is not further relegated to the margins and its quality and integrity sustained.

  17. Prognostics of Power Electronics, Methods and Validation Experiments

    NASA Technical Reports Server (NTRS)

    Kulkarni, Chetan S.; Celaya, Jose R.; Biswas, Gautam; Goebel, Kai

    2012-01-01

    Abstract Failure of electronic devices is a concern for future electric aircrafts that will see an increase of electronics to drive and control safety-critical equipment throughout the aircraft. As a result, investigation of precursors to failure in electronics and prediction of remaining life of electronic components is of key importance. DC-DC power converters are power electronics systems employed typically as sourcing elements for avionics equipment. Current research efforts in prognostics for these power systems focuses on the identification of failure mechanisms and the development of accelerated aging methodologies and systems to accelerate the aging process of test devices, while continuously measuring key electrical and thermal parameters. Preliminary model-based prognostics algorithms have been developed making use of empirical degradation models and physics-inspired degradation model with focus on key components like electrolytic capacitors and power MOSFETs (metal-oxide-semiconductor-field-effect-transistor). This paper presents current results on the development of validation methods for prognostics algorithms of power electrolytic capacitors. Particularly, in the use of accelerated aging systems for algorithm validation. Validation of prognostics algorithms present difficulties in practice due to the lack of run-to-failure experiments in deployed systems. By using accelerated experiments, we circumvent this problem in order to define initial validation activities.

  18. Critical Classrooms: Using Artists' Lives to Teach Young Students Social Groups, Power, and Privilege

    ERIC Educational Resources Information Center

    Silva, Janelle M.

    2012-01-01

    This article uses data from a 9-month ethnography in California to illustrate how elementary teacher's decision to reenact Jane Elliott's "A Class Divided" experiment, in conjunction with an artist-centered multicultural curriculum, shifted classroom conversations to a more critical dialogue of social groups, power, and privilege. Data…

  19. Zero-voltage DC/DC converter with asymmetric pulse-width modulation for DC micro-grid system

    NASA Astrophysics Data System (ADS)

    Lin, Bor-Ren

    2018-04-01

    This paper presents a zero-voltage switching DC/DC converter for DC micro-grid system applications. The proposed circuit includes three half-bridge circuit cells connected in primary-series and secondary-parallel in order to lessen the voltage rating of power switches and current rating of rectifier diodes. Thus, low voltage stress of power MOSFETs can be adopted for high-voltage input applications with high switching frequency operation. In order to achieve low switching losses and high circuit efficiency, asymmetric pulse-width modulation is used to turn on power switches at zero voltage. Flying capacitors are used between each circuit cell to automatically balance input split voltages. Therefore, the voltage stress of each power switch is limited at Vin/3. Finally, a prototype is constructed and experiments are provided to demonstrate the circuit performance.

  20. STS-42 closeup view shows SE 81-09 Convection in Zero Gravity experiment

    NASA Image and Video Library

    1992-01-30

    STS-42 closeup view shows Student Experiment 81-09 (SE 81-09), Convection in Zero Gravity experiment, with radial pattern caused by convection induced by heating an oil and aluminum powder mixture in the weightlessness of space. While the STS-42 crewmembers activated the Shuttle Student Involvement Program (SSIP) experiment on Discovery's, Orbiter Vehicle (OV) 103's, middeck, Scott Thomas, the student who designed the experiment, was able to observe the procedures via downlinked television (TV) in JSC's Mission Control Center (MCC). Thomas, now a physics doctoral student at the University of Texas, came up with the experiment while he participated in the SSIP as a student at Richland High School in Johnstown, Pennsylvia.

  1. Zero-G Workstation Design

    NASA Technical Reports Server (NTRS)

    Gundersen, R. T.; Bond, R. L.

    1976-01-01

    Zero-g workstations were designed throughout manned spaceflight, based on different criteria and requirements for different programs. The history of design of these workstations is presented along with a thorough evaluation of selected Skylab workstations (the best zero-g experience available on the subject). The results were applied to on-going and future programs, with special emphasis on the correlation of neutral body posture in zero-g to workstation design. Where selected samples of shuttle orbiter workstations are shown as currently designed and compared to experience gained during prior programs in terms of man machine interface design, the evaluations were done in a generic sense to show the methods of applying evaluative techniques.

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

    Perret, Gregory

    The critical decay constant (B/A), delayed neutron fraction (B) and generation time (A) of the Minerve reactor were measured by the Paul Scherrer Institut (PSI) and the Commissariat a l'Energie Atomique (CEA) in September 2014 using the Feynman-alpha and Power Spectral Density neutron noise measurement techniques. Three slightly subcritical configuration were measured using two 1-g {sup 235}U fission chambers. This paper reports on the results obtained by PSI in the near critical configuration (-2g). The most reliable and precise results were obtained with the Cross-Power Spectral Density technique: B = 708.4±9.2 pcm, B/A = 79.0±0.6 s{sup -1} and A 89.7±1.4more » micros. Predictions of the same kinetic parameters were obtained with MCNP5-v1.6 and the JEFF-3.1 and ENDF/B-VII.1 nuclear data libraries. On average the predictions for B and B/A overestimate the experimental results by 5% and 11%, respectively. The discrepancy is suspected to come from either a corruption of the data or from the inadequacy of the point kinetic equations to interpret the measurements in the Minerve driven system. (authors)« less

  3. Parametric analyses of planned flowing uranium hexafluoride critical experiments

    NASA Technical Reports Server (NTRS)

    Rodgers, R. J.; Latham, T. S.

    1976-01-01

    Analytical investigations were conducted to determine preliminary design and operating characteristics of flowing uranium hexafluoride (UF6) gaseous nuclear reactor experiments in which a hybrid core configuration comprised of UF6 gas and a region of solid fuel will be employed. The investigations are part of a planned program to perform a series of experiments of increasing performance, culminating in an approximately 5 MW fissioning uranium plasma experiment. A preliminary design is described for an argon buffer gas confined, UF6 flow loop system for future use in flowing critical experiments. Initial calculations to estimate the operating characteristics of the gaseous fissioning UF6 in a confined flow test at a pressure of 4 atm, indicate temperature increases of approximately 100 and 1000 K in the UF6 may be obtained for total test power levels of 100 kW and 1 MW for test times of 320 and 32 sec, respectively.

  4. GMPR: A robust normalization method for zero-inflated count data with application to microbiome sequencing data.

    PubMed

    Chen, Li; Reeve, James; Zhang, Lujun; Huang, Shengbing; Wang, Xuefeng; Chen, Jun

    2018-01-01

    Normalization is the first critical step in microbiome sequencing data analysis used to account for variable library sizes. Current RNA-Seq based normalization methods that have been adapted for microbiome data fail to consider the unique characteristics of microbiome data, which contain a vast number of zeros due to the physical absence or under-sampling of the microbes. Normalization methods that specifically address the zero-inflation remain largely undeveloped. Here we propose geometric mean of pairwise ratios-a simple but effective normalization method-for zero-inflated sequencing data such as microbiome data. Simulation studies and real datasets analyses demonstrate that the proposed method is more robust than competing methods, leading to more powerful detection of differentially abundant taxa and higher reproducibility of the relative abundances of taxa.

  5. Overview of Experiments for Physics of Fast Reactors from the International Handbooks of Evaluated Criticality Safety Benchmark Experiments and Evaluated Reactor Physics Benchmark Experiments

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

    Bess, J. D.; Briggs, J. B.; Gulliford, J.

    Overview of Experiments to Study the Physics of Fast Reactors Represented in the International Directories of Critical and Reactor Experiments John D. Bess Idaho National Laboratory Jim Gulliford, Tatiana Ivanova Nuclear Energy Agency of the Organisation for Economic Cooperation and Development E.V.Rozhikhin, M.Yu.Sem?nov, A.M.Tsibulya Institute of Physics and Power Engineering The study the physics of fast reactors traditionally used the experiments presented in the manual labor of the Working Group on Evaluation of sections CSEWG (ENDF-202) issued by the Brookhaven National Laboratory in 1974. This handbook presents simplified homogeneous model experiments with relevant experimental data, as amended. The Nuclear Energymore » Agency of the Organization for Economic Cooperation and Development coordinates the activities of two international projects on the collection, evaluation and documentation of experimental data - the International Project on the assessment of critical experiments (1994) and the International Project on the assessment of reactor experiments (since 2005). The result of the activities of these projects are replenished every year, an international directory of critical (ICSBEP Handbook) and reactor (IRPhEP Handbook) experiments. The handbooks present detailed models of experiments with minimal amendments. Such models are of particular interest in terms of the settlements modern programs. The directories contain a large number of experiments which are suitable for the study of physics of fast reactors. Many of these experiments were performed at specialized critical stands, such as BFS (Russia), ZPR and ZPPR (USA), the ZEBRA (UK) and the experimental reactor JOYO (Japan), FFTF (USA). Other experiments, such as compact metal assembly, is also of interest in terms of the physics of fast reactors, they have been carried out on the universal critical stands in Russian institutes (VNIITF and VNIIEF) and the US (LANL, LLNL, and others.). Also worth

  6. Asymptotically zero power charge-recycling bus architecture for battery-operated ultrahigh data rate ULSI's

    NASA Astrophysics Data System (ADS)

    Yamauchi, Hiroyuki; Akamatsu, Hironori; Fujita, Tsutomu

    1995-04-01

    An asymptotically zero power charge recycling bus (CRB) architecture, featuring virtual stacking of the individual bus-capacitance into a series configuration between supply voltage and ground, has been proposed. This CRB architecture makes it possible to reduce not only each bus-swing but also a total equivalent bus-capacitance of the ultramultibit buses running in parallel. The voltage swing of each bus is given by the recycled charge-supplying from the upper adjacent bus capacitance, instead of the power line. The dramatical power reduction was verified by the simulated and measured data. According to these data, the ultrahigh data rate of 25.6 Gb/s can be achieved while maintaining the power dissipation to be less than 100 mW, which corresponds to less than 10% that of the previously reported 0.9 V suppressed bus-swing scheme, at V(sub cc) = 3.6 V for the bus width of 512 b with the bus-capacitance of 14 pF per bit operating at 50 MHz.

  7. When Sex and Power Collide: An Argument for Critical Sexuality Studies.

    PubMed

    Fahs, Breanne; McClelland, Sara I

    2016-01-01

    Attentive to the collision of sex and power, we add momentum to the ongoing development of the subfield of critical sexuality studies. We argue that this body of work is defined by its critical orientation toward the study of sexuality, along with a clear allegiance to critical modalities of thought, particularly feminist thought. Critical sexuality studies takes its cues from several other critical moments in related fields, including critical psychology, critical race theory, critical public health, and critical youth studies. Across these varied critical stances is a shared investment in examining how power and privilege operate, understanding the role of historical and epistemological violence in research, and generating new models and paradigms to guide empirical and theoretical research. With this guiding framework, we propose three central characteristics of critical sexuality studies: (a) conceptual analysis, with particular attention to how we define key terms and conceptually organize our research (e.g., attraction, sexually active, consent, agency, embodiment, sexual subjectivity); (b) attention to the material qualities of abject bodies, particularly bodies that are ignored, overlooked, or pushed out of bounds (e.g., viscous bodies, fat bodies, bodies in pain); and (c) heteronormativity and heterosexual privilege, particularly how assumptions about heterosexuality and heteronormativity circulate in sexuality research. Through these three critical practices, we argue that critical sexuality studies showcases how sex and power collide and recognizes (and tries to subvert) the various power imbalances that are deployed and replicated in sex research.

  8. Towards Zero Waste in emerging countries - A South African experience

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

    Matete, Ntlibi; Trois, Cristina

    2008-07-01

    The aim of this paper is to describe the optimisation of Waste Minimisation/Zero Waste strategies into an already established integrated waste management system and to present a Zero Waste model for post-consumer waste for urban communities in South Africa. The research was undertaken towards the fulfilment of the goals of the Polokwane Declaration on Waste Management , which has set as its target the reduction of waste generation and disposal by 50% and 25%, respectively, by 2012 and the development of a plan for Zero Waste by 2022. Two communities, adjacent to the Mariannhill Landfill site in Durban, were selectedmore » as a case study for a comparative analysis of formal and informal settlements. Since the waste generated from these two communities is disposed of at the Mariannhill landfill, the impact of Zero Waste on landfill volumes could be readily assessed. A Zero Waste scheme, based on costs and landfill airspace savings, was proposed for the area. The case study demonstrates that waste minimisation schemes can be introduced into urban areas, in emerging countries, with differing levels of service and that Zero Waste models are appropriate to urban areas in South Africa.« less

  9. Faraday instability in a near-critical fluid under weightlessness.

    PubMed

    Gandikota, G; Chatain, D; Amiroudine, S; Lyubimova, T; Beysens, D

    2014-01-01

    Experiments on near-critical hydrogen have been conducted under magnetic compensation of gravity to investigate the Faraday instability that arises at the liquid-vapor interface under zero-gravity conditions. We investigated such instability in the absence of stabilizing gravity. Under such conditions, vibration orients the interface and can destabilize it. The experiments confirm the existence of Faraday waves and demonstrate a transition from a square to a line pattern close to the critical point. They also show a transition very close to the critical point from Faraday to periodic layering of the vapor-liquid interface perpendicular to vibration. It was seen that the Faraday wave instability is favored when the liquid-vapor density difference is large enough (fluid far from the critical point), whereas periodic layering predominates for small difference in the liquid and vapor densities (close to the critical point). It was observed for the Faraday wave instability that the wavelength of the instability decreases as one approaches the critical point. The experimental results demonstrate good agreement to the dispersion relation for zero gravity except for temperatures very close to the critical point where a transition from a square pattern to a line pattern is detected, similarly to what is observed under 1g conditions.

  10. Zero-G experiments in two-phase fluids flow regimes

    NASA Technical Reports Server (NTRS)

    Heppner, D. B.; King, C. D.; Littles, J. W.

    1975-01-01

    The two-phase flows studied were liquid and gas mixtures in a straight flow channel of circular cross-section. Boundaries between flow regimes have been defined for normogravity on coordinates of gas quality and total mass velocity; and, when combined with boundary expressions having a Froude number term, an analytical model was derived predicting boundary shifts with changes in gravity level. Experiments with air and water were performed, first in the normogravity environment of a ground laboratory and then in 'zero gravity' aboard a KC-135 aircraft flying parabolic trajectories. Data reduction confirmed regime boundary shifts in the direction predicted, although the magnitude was a little less than predicted. Pressure drop measurements showed significant increases for the low gravity condition.

  11. High-power, kilojoule laser interactions with near-critical density plasma

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

    Willingale, L.; Thomas, A. G. R.; Maksimchuk, A.

    Experiments were performed using the Omega EP laser, which provided pulses containing 1kJ of energy in 9ps and was used to investigate high-power, relativistic intensity laser interactions with near-critical density plasmas, created from foam targets with densities of 3-100 mg/cm{sup 3}. The effect of changing the plasma density on both the laser light transmitted through the targets and the proton beam accelerated from the interaction was investigated. Two-dimensional particle-in-cell simulations enabled the interaction dynamics and laser propagation to be studied in detail. The effect of the laser polarization and intensity in the two-dimensional simulations on the channel formation and electronmore » heating are discussed. In this regime, where the plasma density is above the critical density, but below the relativistic critical density, the channel formation speed and therefore length are inversely proportional to the plasma density, which is faster than the hole boring model prediction. A general model is developed to describe the channel length in this regime.« less

  12. NSTA-NASA Shuttle Student Involvement Project. Experiment Results: Insect Flight Observation at Zero Gravity

    NASA Technical Reports Server (NTRS)

    Nelson, T. E.; Peterson, J. R.

    1982-01-01

    The flight responses of common houseflies, velvetbean caterpillar moths, and worker honeybees were observed and filmed for a period of about 25 minutes in a zero-g environment during the third flight of the Space Shuttle Vehicle (flight number STS-3; March 22-30, 1982). Twelve fly puparia, 24 adult moths, 24 moth pupae, and 14 adult bees were loaded into an insect flight box, which was then stowed aboard the Shuttle Orbiter, the night before the STS-3 launch at NASA's Kennedy Space Center (KSC). The main purpose of the experiment was to observe and compare the flight responses of the three species of insects, which have somewhat different flight control mechanisms, under zero-g conditions.

  13. Majorana zero modes in superconductor-semiconductor heterostructures

    NASA Astrophysics Data System (ADS)

    Lutchyn, R. M.; Bakkers, E. P. A. M.; Kouwenhoven, L. P.; Krogstrup, P.; Marcus, C. M.; Oreg, Y.

    2018-05-01

    Realizing topological superconductivity and Majorana zero modes in the laboratory is a major goal in condensed-matter physics. In this Review, we survey the current status of this rapidly developing field, focusing on proposals for the realization of topological superconductivity in semiconductor-superconductor heterostructures. We examine materials science progress in growing InAs and InSb semiconductor nanowires and characterizing these systems. We then discuss the observation of robust signatures of Majorana zero modes in recent experiments, paying particular attention to zero-bias tunnelling conduction measurements and Coulomb blockade experiments. We also outline several next-generation experiments probing exotic properties of Majorana zero modes, including fusion rules and non-Abelian exchange statistics. Finally, we discuss prospects for implementing Majorana-based topological quantum computation.

  14. Modeling of switching regulator power stages with and without zero-inductor-current dwell time

    NASA Technical Reports Server (NTRS)

    Lee, F. C.; Yu, Y.; Triner, J. E.

    1976-01-01

    State space techniques are employed to derive accurate models for buck, boost, and buck/boost converter power stages operating with and without zero-inductor-current dwell time. A generalized procedure is developed which treats the continuous-inductor-current mode without the dwell time as a special case of the discontinuous-current mode, when the dwell time vanishes. An abrupt change of system behavior including a reduction of the system order when the dwell time appears is shown both analytically and experimentally.

  15. The venetian-blind effect: a preference for zero disparity or zero slant?

    PubMed Central

    Vlaskamp, Björn N. S.; Guan, Phillip; Banks, Martin S.

    2013-01-01

    When periodic stimuli such as vertical sinewave gratings are presented to the two eyes, the initial stage of disparity estimation yields multiple solutions at multiple depths. The solutions are all frontoparallel when the sinewaves have the same spatial frequency; they are all slanted when the sinewaves have quite different frequencies. Despite multiple solutions, humans perceive only one depth in each visual direction: a single frontoparallel plane when the frequencies are the same and a series of small slanted planes—Venetian blinds—when the frequencies are quite different. These percepts are consistent with a preference for solutions that minimize absolute disparity or overall slant. The preference for minimum disparity and minimum slant are identical for gaze at zero eccentricity; we dissociated the predictions of the two by measuring the occurrence of Venetian blinds when the stimuli were viewed in eccentric gaze. The results were generally quite consistent with a zero-disparity preference (Experiment 1), but we also observed a shift toward a zero-slant preference when the edges of the stimulus had zero slant (Experiment 2). These observations provide useful insights into how the visual system constructs depth percepts from a multitude of possible depths. PMID:24273523

  16. The venetian-blind effect: a preference for zero disparity or zero slant?

    PubMed

    Vlaskamp, Björn N S; Guan, Phillip; Banks, Martin S

    2013-01-01

    When periodic stimuli such as vertical sinewave gratings are presented to the two eyes, the initial stage of disparity estimation yields multiple solutions at multiple depths. The solutions are all frontoparallel when the sinewaves have the same spatial frequency; they are all slanted when the sinewaves have quite different frequencies. Despite multiple solutions, humans perceive only one depth in each visual direction: a single frontoparallel plane when the frequencies are the same and a series of small slanted planes-Venetian blinds-when the frequencies are quite different. These percepts are consistent with a preference for solutions that minimize absolute disparity or overall slant. The preference for minimum disparity and minimum slant are identical for gaze at zero eccentricity; we dissociated the predictions of the two by measuring the occurrence of Venetian blinds when the stimuli were viewed in eccentric gaze. The results were generally quite consistent with a zero-disparity preference (Experiment 1), but we also observed a shift toward a zero-slant preference when the edges of the stimulus had zero slant (Experiment 2). These observations provide useful insights into how the visual system constructs depth percepts from a multitude of possible depths.

  17. Origin and implications of zero degeneracy in networks spectra.

    PubMed

    Yadav, Alok; Jalan, Sarika

    2015-04-01

    The spectra of many real world networks exhibit properties which are different from those of random networks generated using various models. One such property is the existence of a very high degeneracy at the zero eigenvalue. In this work, we provide all the possible reasons behind the occurrence of the zero degeneracy in the network spectra, namely, the complete and partial duplications, as well as their implications. The power-law degree sequence and the preferential attachment are the properties which enhances the occurrence of such duplications and hence leading to the zero degeneracy. A comparison of the zero degeneracy in protein-protein interaction networks of six different species and in their corresponding model networks indicates importance of the degree sequences and the power-law exponent for the occurrence of zero degeneracy.

  18. Towards zero waste in emerging countries - a South African experience.

    PubMed

    Matete, Ntlibi; Trois, Cristina

    2008-01-01

    The aim of this paper is to describe the optimisation of Waste Minimisation/Zero Waste strategies into an already established integrated waste management system and to present a Zero Waste model for post-consumer waste for urban communities in South Africa. The research was undertaken towards the fulfilment of the goals of the Polokwane Declaration on Waste Management [DEAT, 2001. Department of Environmental Affairs and Tourism, Government of South Africa. Polokwane Declaration. Drafted by Government, Civil Society and the Business Community. National Waste Summit, Polokwane, 26-28 September 2001], which has set as its target the reduction of waste generation and disposal by 50% and 25%, respectively, by 2012 and the development of a plan for Zero Waste by 2022. Two communities, adjacent to the Mariannhill Landfill site in Durban, were selected as a case study for a comparative analysis of formal and informal settlements. Since the waste generated from these two communities is disposed of at the Mariannhill landfill, the impact of Zero Waste on landfill volumes could be readily assessed. A Zero Waste scheme, based on costs and landfill airspace savings, was proposed for the area. The case study demonstrates that waste minimisation schemes can be introduced into urban areas, in emerging countries, with differing levels of service and that Zero Waste models are appropriate to urban areas in South Africa.

  19. Zero-gravity aerosol behavior

    NASA Technical Reports Server (NTRS)

    Edwards, H. W.

    1981-01-01

    The feasibility and scientific benefits of a zero gravity aerosol study in an orbiting laboratory were examined. A macroscopic model was devised to deal with the simultaneous effects of diffusion and coagulation of particles in the confined aerosol. An analytical solution was found by treating the particle coagulation and diffusion constants as ensemble parameters and employing a transformation of variables. The solution was used to carry out simulated zero gravity aerosol decay experiments in a compact cylindrical chamber. The results demonstrate that the limitations of physical space and time imposed by the orbital situation are not prohibitive in terms of observing the history of an aerosol confined under zero gravity conditions. While the absence of convective effects would be a definite benefit for the experiment, the mathematical complexity of the problem is not greatly reduced when the gravitational term drops out of the equation. Since the model does not deal directly with the evolution of the particle size distribution, it may be desirable to develop more detailed models before undertaking an orbital experiment.

  20. Development of the GaAs-based THz Photoconductor and Balloon-borne Experiment Module TG-ZERO

    NASA Astrophysics Data System (ADS)

    Watanabe, Kentaroh; Kataza, Hirokazu; Wada, Takehiko; Murakami, Hiroshi; Kamizuka, Takafumi; Makitsubo, Hironobu; Yamashita, Kyohei; Wakaki, Moriaki; Abe, Osamu

    2009-08-01

    The far-infrared (around 1 terahertz (THz)) extrinsic photoconductor is fabricated by a LPE-grown GaAs semiconductor. This GaAs detector can detect longer wavelength photons than the stressed Ge:Ga conventionally used for astronomical infrared observation. We applied the liquid phase epitaxy to obtain a suitable purity of GaAs crystals, and the test N-GaAs photoconductor device shows spectroscopic response over a wide wavelength range of 150-300 micron. The best sample shows 30 A/W of responsivity and 10-16 W/Hz0.5 of NEP is expected at 295 micron of wavelength and T = 1.6 K. In addition, we constructed the terahertz photometer module (TG-ZERO) using our N-GaAs photoconductors. TG-ZERO has four channel bands with N-GaAs and Ge:Ga photoconductors. The development process, the result of experiments, and the basic specifications of TG-ZERO are all reported in this paper.

  1. IER-297 CED-2: Final Design for Thermal/Epithermal eXperiments with Jemima Plates with Polyethylene and Hafnium

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

    Nelson, A. J.; Percher, C. M.; Zywiec, W. J.

    This report presents the final design (CED-2) for IER-297, and focuses on 15 critical configurations using highly enriched uranium (HEU) Jemima plates moderated by polyethylene with and without hafnium diluent. The goal of the U.S. Nuclear Criticality Safety Program’s Thermal/Epithermal eXperiments (TEX) is to design and conduct new critical experiments to address high priority nuclear data needs from the nuclear criticality safety and nuclear data communities, with special emphasis on intermediate energy (0.625 eV – 100 keV) assemblies that can be easily modified to include various high priority diluent materials. The TEX (IER 184) CED-1 Report [1], completed in 2012,more » demonstrated the feasibility of meeting the TEX goals with two existing NCSP fissile assets, plutonium Zero Power Physics Reactor (ZPPR) plates and highly enriched uranium (HEU) Jemima plates. The first set of TEX experiments will focus on using the plutonium ZPPR plates with polyethylene moderator and tantalum diluents.« less

  2. Experimental physics characteristics of a heavy-metal-reflected fast-spectrum critical assembly

    NASA Technical Reports Server (NTRS)

    Heneveld, W. H.; Paschall, R. K.; Springer, T. H.; Swanson, V. A.; Thiele, A. W.; Tuttle, R. J.

    1972-01-01

    A zero-power critical assembly was designed, constructed, and operated for the purpose of conducting a series of benchmark experiments dealing with the physics characteristics of a UN-fueled, Li-cooled, Mo-reflected, drum-controlled compact fast reactor for use with a space-power electric conversion system. The range of the previous experimental investigations has been expanded to include the reactivity effects of:(1) surrounding the reactor with 15.24 cm (6 in.) of polyethylene, (2) reducing the heights of a portion of the upper and lower axial reflectors by factors of 2 and 4, (3) adding 45 kg of W to the core uniformly in two steps, (4) adding 9.54 kg of Ta to the core uniformly, and (5) inserting 2.3 kg of polyethylene into the core proper and determining the effect of a Ta addition on the polyethylene worth.

  3. Zero-gravity cloud physics.

    NASA Technical Reports Server (NTRS)

    Hollinden, A. B.; Eaton, L. R.; Vaughan, W. W.

    1972-01-01

    The first results of an ongoing preliminary-concept and detailed-feasibility study of a zero-gravity earth-orbital cloud physics research facility are reviewed. Current planning and thinking are being shaped by two major conclusions of this study: (1) there is a strong requirement for and it is feasible to achieve important and significant research in a zero-gravity cloud physics facility; and (2) some very important experiments can be accomplished with 'off-the-shelf' type hardware by astronauts who have no cloud-physics background; the most complicated experiments may require sophisticated observation and motion subsystems and the astronaut may need graduate level cloud physics training; there is a large number of experiments whose complexity varies between these two extremes.

  4. Determination of refractive index of a simple negative, positive, or zero power lens using wedged plated interferometer

    NASA Technical Reports Server (NTRS)

    Shukla, R. P.; Perera, G. M.; George, M. C.; Venkateswarlu, P.

    1990-01-01

    A nondestructive technique for measuring the refractive index of a negative lens using a wedged plate interferometer is described. The method can be also used for measuring the refractive index of convex or zero power lenses. Schematic diagrams are presented for the use of a wedged plate interferometer for measuring the refractive index of a concave lens and of a convex lens.

  5. Statistics of zero crossings in rough interfaces with fractional elasticity

    NASA Astrophysics Data System (ADS)

    Zamorategui, Arturo L.; Lecomte, Vivien; Kolton, Alejandro B.

    2018-04-01

    We study numerically the distribution of zero crossings in one-dimensional elastic interfaces described by an overdamped Langevin dynamics with periodic boundary conditions. We model the elastic forces with a Riesz-Feller fractional Laplacian of order z =1 +2 ζ , such that the interfaces spontaneously relax, with a dynamical exponent z , to a self-affine geometry with roughness exponent ζ . By continuously increasing from ζ =-1 /2 (macroscopically flat interface described by independent Ornstein-Uhlenbeck processes [Phys. Rev. 36, 823 (1930), 10.1103/PhysRev.36.823]) to ζ =3 /2 (super-rough Mullins-Herring interface), three different regimes are identified: (I) -1 /2 <ζ <0 , (II) 0 <ζ <1 , and (III) 1 <ζ <3 /2 . Starting from a flat initial condition, the mean number of zeros of the discretized interface (I) decays exponentially in time and reaches an extensive value in the system size, or decays as a power-law towards (II) a subextensive or (III) an intensive value. In the steady state, the distribution of intervals between zeros changes from an exponential decay in (I) to a power-law decay P (ℓ ) ˜ℓ-γ in (II) and (III). While in (II) γ =1 -θ with θ =1 -ζ the steady-state persistence exponent, in (III) we obtain γ =3 -2 ζ , different from the exponent γ =1 expected from the prediction θ =0 for infinite super-rough interfaces with ζ >1 . The effect on P (ℓ ) of short-scale smoothening is also analyzed numerically and analytically. A tight relation between the mean interval, the mean width of the interface, and the density of zeros is also reported. The results drawn from our analysis of rough interfaces subject to particular boundary conditions or constraints, along with discretization effects, are relevant for the practical analysis of zeros in interface imaging experiments or in numerical analysis.

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

    Patrick, C. E.; Aliaga, L.; Bashyal, A.

    We present double-differential measurements of antineutrino charged-current quasielastic scattering in the MINERvA detector. This study improves on a previous single-differential measurement by using updated reconstruction algorithms and interaction models and provides a complete description of observed muon kinematics in the form of a double-differential cross section with respect to muon transverse and longitudinal momentum. We also include in our signal definition, zero-meson final states arising from multinucleon interactions and from resonant pion production followed by pion absorption in the primary nucleus. We find that model agreement is considerably improved by a model tuned to MINERvA inclusive neutrino scattering data thatmore » incorporates nuclear effects such as weak nuclear screening and two-particle, two-hole enhancements.« less

  7. Measurement of the muon antineutrino double-differential cross section for quasielastic-like scattering on hydrocarbon at Eν˜3.5 GeV

    NASA Astrophysics Data System (ADS)

    Patrick, C. E.; Aliaga, L.; Bashyal, A.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Caceres v., G. F. R.; Carneiro, M. F.; Chavarria, E.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Gran, R.; Han, J. Y.; Harris, D. A.; Henry, S.; Hurtado, K.; Jena, D.; Kleykamp, J.; Kordosky, M.; Le, T.; Lu, X.-G.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; McFarland, K. S.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nowak, G. M.; Nuruzzaman, Paolone, V.; Perdue, G. N.; Peters, E.; Ramírez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Solano Salinas, C. J.; Sultana, M.; Sánchez Falero, S.; Teklu, A. M.; Valencia, E.; Wolcott, J.; Wospakrik, M.; Yaeggy, B.; Zhang, D.; Miner ν A Collaboration

    2018-03-01

    We present double-differential measurements of antineutrino charged-current quasielastic scattering in the MINERvA detector. This study improves on a previous single-differential measurement by using updated reconstruction algorithms and interaction models and provides a complete description of observed muon kinematics in the form of a double-differential cross section with respect to muon transverse and longitudinal momentum. We include in our signal definition zero-meson final states arising from multinucleon interactions and from resonant pion production followed by pion absorption in the primary nucleus. We find that model agreement is considerably improved by a model tuned to MINERvA inclusive neutrino scattering data that incorporates nuclear effects such as weak nuclear screening and two-particle, two-hole enhancements.

  8. Measurement of the muon antineutrino double-differential cross section for quasielastic-like scattering on hydrocarbon at E ν ~ 3.5 GeV

    DOE PAGES

    Patrick, C. E.; Aliaga, L.; Bashyal, A.; ...

    2018-03-08

    We present double-differential measurements of antineutrino charged-current quasielastic scattering in the MINERvA detector. This study improves on a previous single-differential measurement by using updated reconstruction algorithms and interaction models and provides a complete description of observed muon kinematics in the form of a double-differential cross section with respect to muon transverse and longitudinal momentum. We also include in our signal definition, zero-meson final states arising from multinucleon interactions and from resonant pion production followed by pion absorption in the primary nucleus. We find that model agreement is considerably improved by a model tuned to MINERvA inclusive neutrino scattering data thatmore » incorporates nuclear effects such as weak nuclear screening and two-particle, two-hole enhancements.« less

  9. Implementing NICU critical thinking programs: one unit's experience.

    PubMed

    Zimmerman, Denise; Pilcher, Jobeth

    2008-01-01

    Critical thinking is the hallmark of today's nursing practice environment. Nowhere is this more critical than in the high-tech environment of the NICU. Despite the importance of critical thinking in nursing practice, there is limited information on the process of teaching new NICU nurses to think critically. Based on the principles of adult education, orientation and continuing education for NICU nurses should be goal directed, build on the learner's prior experience, and build in opportunities for active participation, reflection, and experiential learning. This article reviews the principles of adult education and their application to the process of teaching critical thinking in the NICU. One unit's experience of critical thinking education is used to provide concrete examples of how NICU education can be transformed from a traditional didactic methodology to a more dynamic experiential approach.

  10. Neutron dose estimation in a zero power nuclear reactor

    NASA Astrophysics Data System (ADS)

    Triviño, S.; Vedelago, J.; Cantargi, F.; Keil, W.; Figueroa, R.; Mattea, F.; Chautemps, A.; Santibañez, M.; Valente, M.

    2016-10-01

    This work presents the characterization and contribution of neutron and gamma components to the absorbed dose in a zero power nuclear reactor. A dosimetric method based on Fricke gel was implemented to evaluate the separation between dose components in the mixed field. The validation of this proposed method was performed by means of direct measurements of neutron flux in different positions using Au and Mg-Ni activation foils. Monte Carlo simulations were conversely performed using the MCNP main code with a dedicated subroutine to incorporate the exact complete geometry of the nuclear reactor facility. Once nuclear fuel elements were defined, the simulations computed the different contributions to the absorbed dose in specific positions inside the core. Thermal/epithermal contributions of absorbed dose were assessed by means of Fricke gel dosimetry using different isotopic compositions aimed at modifying the sensitivity of the dosimeter for specific dose components. Clear distinctions between gamma and neutron capture dose were obtained. Both Monte Carlo simulations and experimental results provided reliable estimations about neutron flux rate as well as dose rate during the reactor operation. Simulations and experimental results are in good agreement in every positions measured and simulated in the core.

  11. The power and robustness of maximum LOD score statistics.

    PubMed

    Yoo, Y J; Mendell, N R

    2008-07-01

    The maximum LOD score statistic is extremely powerful for gene mapping when calculated using the correct genetic parameter value. When the mode of genetic transmission is unknown, the maximum of the LOD scores obtained using several genetic parameter values is reported. This latter statistic requires higher critical value than the maximum LOD score statistic calculated from a single genetic parameter value. In this paper, we compare the power of maximum LOD scores based on three fixed sets of genetic parameter values with the power of the LOD score obtained after maximizing over the entire range of genetic parameter values. We simulate family data under nine generating models. For generating models with non-zero phenocopy rates, LOD scores maximized over the entire range of genetic parameters yielded greater power than maximum LOD scores for fixed sets of parameter values with zero phenocopy rates. No maximum LOD score was consistently more powerful than the others for generating models with a zero phenocopy rate. The power loss of the LOD score maximized over the entire range of genetic parameters, relative to the maximum LOD score calculated using the correct genetic parameter value, appeared to be robust to the generating models.

  12. Benchmarking study of the MCNP code against cold critical experiments

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

    Sitaraman, S.

    1991-01-01

    The purpose of this study was to benchmark the widely used Monte Carlo code MCNP against a set of cold critical experiments with a view to using the code as a means of independently verifying the performance of faster but less accurate Monte Carlo and deterministic codes. The experiments simulated consisted of both fast and thermal criticals as well as fuel in a variety of chemical forms. A standard set of benchmark cold critical experiments was modeled. These included the two fast experiments, GODIVA and JEZEBEL, the TRX metallic uranium thermal experiments, the Babcock and Wilcox oxide and mixed oxidemore » experiments, and the Oak Ridge National Laboratory (ORNL) and Pacific Northwest Laboratory (PNL) nitrate solution experiments. The principal case studied was a small critical experiment that was performed with boiling water reactor bundles.« less

  13. Benchmark gas core critical experiment.

    NASA Technical Reports Server (NTRS)

    Kunze, J. F.; Lofthouse, J. H.; Cooper, C. G.; Hyland, R. E.

    1972-01-01

    A critical experiment with spherical symmetry has been conducted on the gas core nuclear reactor concept. The nonspherical perturbations in the experiment were evaluated experimentally and produce corrections to the observed eigenvalue of approximately 1% delta k. The reactor consisted of a low density, central uranium hexafluoride gaseous core, surrounded by an annulus of void or low density hydrocarbon, which in turn was surrounded with a 97-cm-thick heavy water reflector.

  14. Zero-state Markov switching count-data models: an empirical assessment.

    PubMed

    Malyshkina, Nataliya V; Mannering, Fred L

    2010-01-01

    In this study, a two-state Markov switching count-data model is proposed as an alternative to zero-inflated models to account for the preponderance of zeros sometimes observed in transportation count data, such as the number of accidents occurring on a roadway segment over some period of time. For this accident-frequency case, zero-inflated models assume the existence of two states: one of the states is a zero-accident count state, which has accident probabilities that are so low that they cannot be statistically distinguished from zero, and the other state is a normal-count state, in which counts can be non-negative integers that are generated by some counting process, for example, a Poisson or negative binomial. While zero-inflated models have come under some criticism with regard to accident-frequency applications - one fact is undeniable - in many applications they provide a statistically superior fit to the data. The Markov switching approach we propose seeks to overcome some of the criticism associated with the zero-accident state of the zero-inflated model by allowing individual roadway segments to switch between zero and normal-count states over time. An important advantage of this Markov switching approach is that it allows for the direct statistical estimation of the specific roadway-segment state (i.e., zero-accident or normal-count state) whereas traditional zero-inflated models do not. To demonstrate the applicability of this approach, a two-state Markov switching negative binomial model (estimated with Bayesian inference) and standard zero-inflated negative binomial models are estimated using five-year accident frequencies on Indiana interstate highway segments. It is shown that the Markov switching model is a viable alternative and results in a superior statistical fit relative to the zero-inflated models.

  15. Zero-gravity movement studies

    NASA Technical Reports Server (NTRS)

    Badler, N. I.; Fishwick, P.; Taft, N.; Agrawala, M.

    1985-01-01

    The use of computer graphics to simulate the movement of articulated animals and mechanisms has a number of uses ranging over many fields. Human motion simulation systems can be useful in education, medicine, anatomy, physiology, and dance. In biomechanics, computer displays help to understand and analyze performance. Simulations can be used to help understand the effect of external or internal forces. Similarly, zero-gravity simulation systems should provide a means of designing and exploring the capabilities of hypothetical zero-gravity situations before actually carrying out such actions. The advantage of using a simulation of the motion is that one can experiment with variations of a maneuver before attempting to teach it to an individual. The zero-gravity motion simulation problem can be divided into two broad areas: human movement and behavior in zero-gravity, and simulation of articulated mechanisms.

  16. Modeling of switching regulator power stages with and without zero-inductor-current dwell time

    NASA Technical Reports Server (NTRS)

    Lee, F. C. Y.; Yu, Y.

    1979-01-01

    State-space techniques are employed to derive accurate models for the three basic switching converter power stages: buck, boost, and buck/boost operating with and without zero-inductor-current dwell time. A generalized procedure is developed which treats the continuous-inductor-current mode without dwell time as a special case of the discontinuous-current mode when the dwell time vanishes. Abrupt changes of system behavior, including a reduction of the system order when the dwell time appears, are shown both analytically and experimentally. Merits resulting from the present modeling technique in comparison with existing modeling techniques are illustrated.

  17. Mathematical Power: Exploring Critical Pedagogy in Mathematics and Statistics

    ERIC Educational Resources Information Center

    Lesser, Lawrence M.; Blake, Sally

    2007-01-01

    Though traditionally viewed as value-free, mathematics is actually one of the most powerful, yet underutilized, venues for working towards the goals of critical pedagogy--social, political and economic justice for all. This emerging awareness is due to how critical mathematics educators such as Frankenstein, Skovsmose and Gutstein have applied the…

  18. Zero Benefit: Estimating the Effect of Zero Tolerance Discipline Polices on Racial Disparities in School Discipline

    ERIC Educational Resources Information Center

    Hoffman, Stephen

    2014-01-01

    This study estimates the effect of zero tolerance disciplinary policies on racial disparities in school discipline in an urban district. Capitalizing on a natural experiment, the abrupt expansion of zero tolerance discipline policies in a mid-sized urban school district, the study demonstrates that Black students in the district were…

  19. Structural zeroes and zero-inflated models.

    PubMed

    He, Hua; Tang, Wan; Wang, Wenjuan; Crits-Christoph, Paul

    2014-08-01

    In psychosocial and behavioral studies count outcomes recording the frequencies of the occurrence of some health or behavior outcomes (such as the number of unprotected sexual behaviors during a period of time) often contain a preponderance of zeroes because of the presence of 'structural zeroes' that occur when some subjects are not at risk for the behavior of interest. Unlike random zeroes (responses that can be greater than zero, but are zero due to sampling variability), structural zeroes are usually very different, both statistically and clinically. False interpretations of results and study findings may result if differences in the two types of zeroes are ignored. However, in practice, the status of the structural zeroes is often not observed and this latent nature complicates the data analysis. In this article, we focus on one model, the zero-inflated Poisson (ZIP) regression model that is commonly used to address zero-inflated data. We first give a brief overview of the issues of structural zeroes and the ZIP model. We then given an illustration of ZIP with data from a study on HIV-risk sexual behaviors among adolescent girls. Sample codes in SAS and Stata are also included to help perform and explain ZIP analyses.

  20. Critical power for self-focusing of optical beam in absorbing media

    NASA Astrophysics Data System (ADS)

    Qi, Pengfei; Zhang, Lin; Lin, Lie; Zhang, Nan; Wang, Yan; Liu, Weiwei

    2018-04-01

    Self-focusing effects are of central importance for most nonlinear optical effects. The critical power for self-focusing is commonly investigated theoretically without considering a material’s absorption. Although this is practicable for various materials, investigating the critical power for self-focusing in media with non-negligible absorption is also necessary, because this is the situation usually met in practice. In this paper, the simple analytical expressions describing the relationships among incident power, absorption coefficient and focal position are provided by a simple physical model based on the Fermat principle. Expressions for the absorption dependent critical power are also derived; these can play important roles in experimental and applied research on self-focusing-related nonlinear optical phenomena in absorbing media. Numerical results, based on the nonlinear wave equation—and which can predict experimental results perfectly—are also presented, and agree quantitatively with the analytical results proposed in this paper.

  1. Black Male Perspectives on Their Educational Experiences in High School

    ERIC Educational Resources Information Center

    Caton, Marcia Theresa

    2012-01-01

    This study examines the impact of the zero-tolerance policies on Black males' educational experiences and outcomes. Individual interviews were conducted with Black males who dropped out of high school. Using counter-storytelling within a critical race theory framework, Black males discussed the influence of the zero-tolerance policies on their…

  2. A Discussion of Zero Spring Rate Mechanisms Used for the Active Isolation Mount Experiment

    NASA Technical Reports Server (NTRS)

    Teter, John E., Jr.

    1999-01-01

    In the summer of 1995 the Structural Dynamics Branch at NASA Langley Research Center set out to conceive a small, lightweight, low frequency isolation mount that could be used for spaceflight experiments. The Engineering Design Branch undertook the task of developing the isolation mount. This report describes the engineering process that led to three phases of a study entitled "Active Isolation Mounts" (AIM). A zero spring rate mechanism was used to achieve low fundamental frequencies for a payloads in the 1 to 10 pound range. It worked by balancing both a positive and a negative stiffness so that the net result was a small positive stiffness. The study demonstrated devices that could reduce the initial corner frequency by a factor of six for brief periods and a factor of two for extended periods. The designs were relatively simple and minimized weight, volume, and power. They could be scaled down and they were made of spaceflight compatible materials. All designs offered the ability to continuously vary the fundamental frequency. Yet, the goal of reducing the frequency by an order of magnitude was not achieved because the systems were too unstable at low frequencies. There was a trade between performance and stability.

  3. Neutrino Flux Prediction for the NuMI Beamline

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

    Soplin, Leonidas Aliaga

    2016-01-01

    The determination of the neutrino flux in any conventional neutrino beam presents a challenge for the current and future short and long baseline neutrino experiments. The uncertainties associated with the production and attenuation of the hadrons in the beamline materials along with those associated with the beam optics have a big effect in the flux spectrum knowledge. For experiments like MINERvA, understanding the flux is crucial since it enters directly into every neutrino-nucleus cross-sections measurements. The foundation of this work is predicting the neutrino flux at MINERvA using dedicated measurements of hadron production in hadron-nucleus collisions and incorporating in-situ MINERvAmore » data that can provide additional constraints. This work also includes the prospect for predicting the flux at other detectors like the NOvA Near detector. The procedure and conclusions of this thesis will have a big impact on future hadron production experiments and on determining the flux for the upcoming DUNE experiment.« less

  4. Neutrino Flux Prediction for the NuMI Beamline

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

    Aliaga Soplin, Leonidas

    2016-01-01

    The determination of the neutrino flux in any conventional neutrino beam presents a challenge for the current and future short and long baseline neutrino experiments. The uncertainties associated with the production and attenuation of the hadrons in the beamline materials along with those associated with the beam optics have a big effect in the flux spectrum knowledge. For experiments like MINERvA, understanding the flux is crucial since it enters directly into every neutrino-nucleus cross-sections measurements. The foundation of this work is predicting the neutrino flux at MINERvA using dedicated measurements of hadron production in hadron-nucleus collisions and incorporating in-situ MINERvAmore » data that can provide additional constraints. This work also includes the prospect for predicting the flux at other detectors like the NOvA Near detector. The procedure and conclusions of this thesis will have a big impact on future hadron production experiments and on determining the fl ux for the upcoming DUNE experiment.« less

  5. A zero-voltage-switched three-phase interleaved buck converter

    NASA Astrophysics Data System (ADS)

    Hsieh, Yao-Ching; Huang, Bing-Siang; Lin, Jing-Yuan; Pham, Phu Hieu; Chen, Po-Hao; Chiu, Huang-Jen

    2018-04-01

    This paper proposes a three-phase interleaved buck converter which is composed of three identical paralleled buck converters. The proposed solution has three shunt inductors connected between each other of three basic buck conversion units. With the help of the shunt inductors, the MOSFET parasitic capacitances will resonate to achieve zero-voltage-switching. Furthermore, the decreasing rate of the current through the free-wheeling diodes is limited, and therefore, their reverse-recovery losses can be minimised. The active power switches are controlled by interleaved pulse-width modulation signals to reduce the input and output current ripples. Therefore, the filtering capacitances on the input and output sides can be reduced. The power efficiency is measured to be as high as 98% in experiment with a prototype circuit.

  6. Jezebel: Reconstructing a Critical Experiment from 60 Years Ago

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

    Favorite, Jeffrey A.

    The Jezebel experiment of 1954-1955 was a very small, nearly-spherical, nearly-bare (unreflected), nearly-homogeneous assembly of plutonium alloyed with gallium. This experiment was used to determine the critical mass of spherical, bare, homogeneous Pu-alloy. In 1956, the critical mass of Pu-alloy was determined to be 16.45 ± 0.05 kg. The experiment was reevaluated in 1969 using logbooks from the 1950s and updated nuclear cross sections. The critical mass of Pu-alloy was determined to be 16.57 ± 0.10 kg. In 2013, the 239Pu Jezebel experiment was again reevaluated, this time using detailed geometry and materials models and modern nuclear cross sections inmore » high-fidelity Monte Carlo neutron transport calculations. Documentation from the 1950s was often inconsistent or missing altogether, and assumptions had to be made. The critical mass of Pu-alloy was determined to be 16.624 ± 0.075 kg. Historic documents were subsequently found that validated some of the 2013 assumptions and invalidated others. In 2016, the newly found information was used to once again reevaluate the 239Pu Jezebel experiment. The critical mass of Pu-alloy was determined to be 16.624 ± 0.065 kg. This talk will discuss each of these evaluations, focusing on the calculation of the uncertainty as well as the critical mass. We call attention to the ambiguity, consternation, despair, and euphoria involved in reconstructing the historic Jezebel experiment. This talk is quite accessible for undergraduate students as well as non-majors.« less

  7. DEVELOPING CRITICAL READING POWER THROUGH NEWSPAPER READING.

    ERIC Educational Resources Information Center

    SAILER, CARL

    A METHOD OF DEVELOPING CRITICAL READING POWER BY ANALYZING ADVERTISEMENTS, CARTOONS, EDITORIALS, AND CONTROVERSIAL ISSUES FOUND IN NEWSPAPERS IS DESCRIBED. SPECIFIC EXAMPLES OF TEACHING PROCEDURES ARE GIVEN. IT IS SUGGESTED THAT A WIDE RANGE OF NEWSPAPERS BE USED SO THAT THE DIFFERENT VIEWPOINTS EXPRESSED IN COLUMNS, EDITORIALS, AND POLITICAL NEWS…

  8. Providing Nuclear Criticality Safety Analysis Education through Benchmark Experiment Evaluation

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

    John D. Bess; J. Blair Briggs; David W. Nigg

    2009-11-01

    One of the challenges that today's new workforce of nuclear criticality safety engineers face is the opportunity to provide assessment of nuclear systems and establish safety guidelines without having received significant experience or hands-on training prior to graduation. Participation in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and/or the International Reactor Physics Experiment Evaluation Project (IRPhEP) provides students and young professionals the opportunity to gain experience and enhance critical engineering skills.

  9. Mobility, Deposition and Remobilization of pre-Synthesis Stabilized Nano-scale Zero Valent Iron in Long Column Experiments

    NASA Astrophysics Data System (ADS)

    de Boer, C. V.; O'Carroll, D. M.; Sleep, B.

    2014-12-01

    Reactive zero-valent iron is currently being used for remediation of contaminated groundwater. Permeable reactive barriers are the current state-of-the-practice method for using zero-valent iron. Instead of an excavated trench filled with granular zero-valent iron, a relatively new and promising method is the injection of a nano-scale zero-valent iron colloid suspension (nZVI) into the subsurface using injection wells. One goal of nZVI injection can be to deposit zero valent iron in the aquifer and form a reactive permeable zone which is no longer bound to limited depths and plume treatment, but can also be used directly at the source. It is very important to have a good understanding of the transport behavior of nZVI during injection as well as the fate of nZVI after injection due to changes in the flow regime or water chemistry changes. So far transport was mainly tested using commercially available nZVI, however these studies suggest that further work is required as commercial nZVI was prone to aggregation, resulting in low physical stability of the suspension and very short travel distances in the subsurface. In the presented work, nZVI is stabilized during synthesis to significantly increase the physical suspension stability. To improve our understanding of nZVI transport, the feasibility for injection into various porous media materials and controlled deposition, a suite of column experiments are conducted. The column experiments are performed using a long 1.5m column and a novel nZVI measuring technique. The measuring technique was developed to non-destructively determine the concentration of nano-scale iron during the injection. It records the magnetic susceptibility, which makes it possible to get transient nZVI retention profiles along the column. These transient nZVI retention profiles of long columns provide unique insights in the transport behavior of nZVI which cannot be obtained using short columns or effluent breakthrough curves.

  10. An Experimental Study of Boiling in Reduced and Zero Gravity Fields

    NASA Technical Reports Server (NTRS)

    Usiskin, C. M.; Siegel, R.

    1961-01-01

    A pool boiling apparatus was mounted on a counterweighted platform which could be dropped a distance of nine feet. By varying the size of the counterweight, the effective gravity field on the equipment was adjusted between zero and unity. A study of boiling burnout in water indicated that a variation in the critical heat flux according to the one quarter power of gravity was reasonable. A consideration of the transient burnout process was necessary in order to properly interpret the data. A photographic study of nucleate boiling showed how the velocity of freely rising vapor bubbles decreased as gravity was reduced. The bubble diameters at the time of breakoff from the heated surface were found to vary inversely as gravity to the 1/3.5 power. Motion pictures were taken to illustrate both nucleate and film boiling in the low gravity range.

  11. CREW TRAINING - STS-33/51L (ZERO-G)

    NASA Image and Video Library

    1985-10-16

    Teacher-in-Space trainees on the KC-135 for Zero-G training. Sharon Christa McAuliffe experiences a few moments of weightlessness provided by the KC-135. She and Bob Mayfield, a JSC Aerospace Education Specialist, are previewing a Molecular Mixing Experiment which was designed to demonstrate differences of separation process in 1-G and Zero-G.

  12. A critical exploration of how English language learners experience nursing education.

    PubMed

    Mulready-Shick, N

    2013-01-01

    With nursing education reform calling for greater numbers of graduates from diverse backgrounds, this study explored the experiences of students who identified as English language learners (ELs). Educators may view students from underrepresented groups at the margins of nursing education. Minimal research on the experiences of students identifying as ELs exists. Interpretive phenomenological and critical methodologies were used to explore students' lived experiences in the nursing classroom. Academic progress involved additional time and effort dedicated to learning English and the languages of health care and nursing. Traditional and monocultural pedagogical practices, representing acts of power and dominance, thwarted learning. Yet students made progress despite less effective pedagogical practices and socioeconomic realities. This inquiry began with one notion of identity, "English-learners," but evolved to students' perceptions of "being-in-the-world," wholeness, and future endeavors. This study counters the dominant view that students without a greater command of English are not ready for the rigors of nursing education.

  13. Work and power fluctuations in a critical heat engine.

    PubMed

    Holubec, Viktor; Ryabov, Artem

    2017-09-01

    We investigate fluctuations of output work for a class of Stirling heat engines with working fluid composed of interacting units and compare these fluctuations to an average work output. In particular, we focus on engine performance close to a critical point where Carnot's efficiency may be attained at a finite power as reported by M. Campisi and R. Fazio [Nat. Commun. 7, 11895 (2016)2041-172310.1038/ncomms11895]. We show that the variance of work output per cycle scales with the same critical exponent as the heat capacity of the working fluid. As a consequence, the relative work fluctuation diverges unless the output work obeys a rather strict scaling condition, which would be very hard to fulfill in practice. Even under this condition, the fluctuations of work and power do not vanish in the infinite system size limit. Large fluctuations of output work thus constitute inseparable and dominant element in performance of the macroscopic heat engines close to a critical point.

  14. Work and power fluctuations in a critical heat engine

    NASA Astrophysics Data System (ADS)

    Holubec, Viktor; Ryabov, Artem

    2017-09-01

    We investigate fluctuations of output work for a class of Stirling heat engines with working fluid composed of interacting units and compare these fluctuations to an average work output. In particular, we focus on engine performance close to a critical point where Carnot's efficiency may be attained at a finite power as reported by M. Campisi and R. Fazio [Nat. Commun. 7, 11895 (2016), 10.1038/ncomms11895]. We show that the variance of work output per cycle scales with the same critical exponent as the heat capacity of the working fluid. As a consequence, the relative work fluctuation diverges unless the output work obeys a rather strict scaling condition, which would be very hard to fulfill in practice. Even under this condition, the fluctuations of work and power do not vanish in the infinite system size limit. Large fluctuations of output work thus constitute inseparable and dominant element in performance of the macroscopic heat engines close to a critical point.

  15. Assessing effects of structural zeros on models of canine cancer incidence: a case study of the Swiss Canine Cancer Registry.

    PubMed

    Boo, Gianluca; Leyk, Stefan; Fabrikant, Sara Irina; Pospischil, Andreas; Graf, Ramona

    2017-05-11

    Epidemiological research of canine cancers could inform comparative studies of environmental determinants for a number of human cancers. However, such an approach is currently limited because canine cancer data sources are still few in number and often incomplete. Incompleteness is typically due to under-ascertainment of canine cancers. A main reason for this is because dog owners commonly do not seek veterinary care for this diagnosis. Deeper knowledge on under-ascertainment is critical for modelling canine cancer incidence, as an indication of zero incidence might originate from the sole absence of diagnostic examinations within a given sample unit. In the present case study, we investigated effects of such structural zeros on models of canine cancer incidence. In doing so, we contrasted two scenarios for modelling incidence data retrieved from the Swiss Canine Cancer Registry. The first scenario was based on the complete enumeration of incidence data for all Swiss municipal units. The second scenario was based on a filtered sample that systematically discarded structural zeros in those municipal units where no diagnostic examination had been performed. By means of cross-validation, we assessed and contrasted statistical performance and predictive power of the two modelling scenarios. This analytical step allowed us to demonstrate that structural zeros impact on the generalisability of the model of canine cancer incidence, thus challenging future comparative studies of canine and human cancers. The results of this case study show that increased awareness about the effects of structural zeros is critical to epidemiological research.

  16. Analyzing the thermionic reactor critical experiments. [thermal spectrum of uranium 235 core

    NASA Technical Reports Server (NTRS)

    Niederauer, G. F.

    1973-01-01

    The Thermionic Reactor Critical Experiments (TRCE) consisted of fast spectrum highly enriched U-235 cores reflected by different thicknesses of beryllium or beryllium oxide with a transition zone of stainless steel between the core and reflector. The mixed fast-thermal spectrum at the core reflector interface region poses a difficult neutron transport calculation. Calculations of TRCE using ENDF/B fast spectrum data and GATHER library thermal spectrum data agreed within about 1 percent for the multiplication factor and within 6 to 8 percent for the power peaks. Use of GAM library fast spectrum data yielded larger deviations. The results were obtained from DOT R Theta calculations with leakage cross sections, by region and by group, extracted from DOT RZ calculations. Delineation of the power peaks required extraordinarily fine mesh size at the core reflector interface.

  17. Zero gravity tissue-culture laboratory

    NASA Technical Reports Server (NTRS)

    Cook, J. E.; Montgomery, P. O., Jr.; Paul, J. S.

    1972-01-01

    Hardware was developed for performing experiments to detect the effects that zero gravity may have on living human cells. The hardware is composed of a timelapse camera that photographs the activity of cell specimens and an experiment module in which a variety of living-cell experiments can be performed using interchangeable modules. The experiment is scheduled for the first manned Skylab mission.

  18. Zero Power Warming (ZPW) Chamber Prototype Measurements, Barrow, Alaska, 2016

    DOE Data Explorer

    Shawn Serbin; Alistair Rogers; Kim Ely

    2017-02-10

    Data were collected during one season of prototyping associated with the development of a passive warming technology. An experimental chamber, the Zero Power Warming (ZPW) chamber, was fitted with apparatus to modulate venting of a field enclosure and enhance elevation of air temperature by solar radiation. The ZPW chamber was compared with a control chamber (Control) and an ambient open air plot (Ambient). The control chamber was identical to the ZPW chamber but lacked the apparatus necessary to modulate venting, the chamber vents in the control chamber were fixed open for the majority of the trial period. The three plots were located over Carex aquatilis growing in an area of moderately degraded permafrost. Chambers were placed on the same footprints that were used for a similar exercise in 2015 (no data) and therefore those plots had experienced some thaw and degradation prior to 2016. The following data were collected for 80 days at 1 minute intervals from within two chambers and an ambient plot: solar input, chamber venting, air temperature, relative humidity, soil temperature (at 5, 10 and 15 cm), soil moisture, downward and upward NIR.

  19. NASA Net Zero Energy Buildings Roadmap

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

    Pless, S.; Scheib, J.; Torcellini, P.

    In preparation for the time-phased net zero energy requirement for new federal buildings starting in 2020, set forth in Executive Order 13514, NASA requested that the National Renewable Energy Laboratory (NREL) to develop a roadmap for NASA's compliance. NASA detailed a Statement of Work that requested information on strategic, organizational, and tactical aspects of net zero energy buildings. In response, this document presents a high-level approach to net zero energy planning, design, construction, and operations, based on NREL's first-hand experience procuring net zero energy construction, and based on NREL and other industry research on net zero energy feasibility. The strategicmore » approach to net zero energy starts with an interpretation of the executive order language relating to net zero energy. Specifically, this roadmap defines a net zero energy acquisition process as one that sets an aggressive energy use intensity goal for the building in project planning, meets the reduced demand goal through energy efficiency strategies and technologies, then adds renewable energy in a prioritized manner, using building-associated, emission- free sources first, to offset the annual energy use required at the building; the net zero energy process extends through the life of the building, requiring a balance of energy use and production in each calendar year.« less

  20. Critical Pedagogy, Cultural Politics, and the Discourse of Experience.

    ERIC Educational Resources Information Center

    Giroux, Henry A.

    1985-01-01

    Analyzes how traditional and liberal discourses treat the intersection of culture, power, and knowledge in fashioning a view of teaching and learning. Argues that both traditions fail as modes of critical pedagogy and that it is necessary to develop a critical discourse that embraces pedagogy as a form of cultural politics. (Author/GC)

  1. Zero tolerance laws for youth : four states' experience

    DOT National Transportation Integrated Search

    2000-06-01

    This report summarizes a study of zero tolerance drinking driving laws for youth in four states. These laws prohibit driving by persons under 21 at a Blood Alcohol Concentration (BAC) over .00, .01 or .02 (depending on the state) in contrast to the l...

  2. Implementation of a near-zero fluoroscopy approach in interventional electrophysiology: impact of operator experience.

    PubMed

    Wannagat, Severin; Loehr, Lena; Lask, Sebastian; Völk, Katharina; Karaköse, Tamer; Özcelik, Cemil; Mügge, Andreas; Wutzler, Alexander

    2018-04-01

    Catheter ablation is performed under fluoroscopic guidance. Reduction of radiation dose for patients and staff is emphasized by current recommendations. Previous studies have shown that lower operator experience leads to increased radiation dose. On the other hand, less experienced operators may depend even more on fluoroscopic guidance. Our study aimed to evaluate feasibility and efficacy of a non-fluoroscopic approach in different training levels. From January 2017, a near-zero fluoroscopy approach was established in two centers. Four operators (beginner, 1st year fellow, 2nd year fellow, expert) were instructed to perform the complete procedure with the use of a 3-D mapping system without fluoroscopy. A historical cohort that underwent procedures with fluoroscopy use served as control group. Dose area product (DPA), procedure duration, acute procedural success, and complications were compared between the groups and for each operator. Procedures were performed in 157 patients. The first 100 patients underwent procedures with fluoroscopic guidance, the following 57 procedures were performed with the near-zero fluoroscopy approach. The results show a significant reduction in DPA for all operators immediately after implementation of the near-zero fluoroscopy protocol (control 637 ± 611 μGy/m 2 ; beginner 44.1 ± 79.5 μGy/m 2 , p = 0.002; 1st year fellow 24.3 ± 46.4.5 μGy/m 2 , p = 0.001; 2nd year fellow 130.3 ± 233.3 μGy/m 2 , p = 0.003; expert 9.3 ± 37.4 μGy/m 2 , P < 0.001). Procedure duration, acute success, and complications were not significantly different between the groups. Our results show a 90% reduction of DPA shortly after implementation of a near-zero fluoroscopy approach in interventional electrophysiology even in operators in training.

  3. Space station experiment definition: Advanced power system test bed

    NASA Technical Reports Server (NTRS)

    Pollard, H. E.; Neff, R. E.

    1986-01-01

    A conceptual design for an advanced photovoltaic power system test bed was provided and the requirements for advanced photovoltaic power system experiments better defined. Results of this study will be used in the design efforts conducted in phase B and phase C/D of the space station program so that the test bed capabilities will be responsive to user needs. Critical PV and energy storage technologies were identified and inputs were received from the idustry (government and commercial, U.S. and international) which identified experimental requirements. These inputs were used to develop a number of different conceptual designs. Pros and cons of each were discussed and a strawman candidate identified. A preliminary evolutionary plan, which included necessary precursor activities, was established and cost estimates presented which would allow for a successful implementation to the space station in the 1994 time frame.

  4. Critical care nurses' experiences when technology malfunctions.

    PubMed

    Haghenbeck, Karen Toby

    2005-01-01

    When caring for critically ill patients, critical care nurses work with technology every day. Technology and equipment malfunctions can have a profound effect on nurses' practice and self-image. In this article, a descriptive phenomenological methodology was chosen to explicate the experience of seven critical care nurses. While participants realized that machines might malfunction, they experienced surprise, shock, and feelings of being "let down" and inadequate when malfunctions occurred. They questioned their competence and felt malfunctioning technology jeopardized their credibility and professional image. These findings are useful when structuring educational sessions on technology and in facilitating a supportive environment for critical care nurses when technology malfunctions.

  5. Critical point wetting drop tower experiment

    NASA Technical Reports Server (NTRS)

    Kaukler, W. F.; Tcherneshoff, L. M.; Straits, S. R.

    1984-01-01

    Preliminary results for the Critical Point Wetting CPW Drop Tower Experiment are produced with immiscible systems. Much of the observed phenomena conformed to the anticipated behavior. More drops will be needed to test the CPW theory with these immiscible systems.

  6. A test of inflated zeros for Poisson regression models.

    PubMed

    He, Hua; Zhang, Hui; Ye, Peng; Tang, Wan

    2017-01-01

    Excessive zeros are common in practice and may cause overdispersion and invalidate inference when fitting Poisson regression models. There is a large body of literature on zero-inflated Poisson models. However, methods for testing whether there are excessive zeros are less well developed. The Vuong test comparing a Poisson and a zero-inflated Poisson model is commonly applied in practice. However, the type I error of the test often deviates seriously from the nominal level, rendering serious doubts on the validity of the test in such applications. In this paper, we develop a new approach for testing inflated zeros under the Poisson model. Unlike the Vuong test for inflated zeros, our method does not require a zero-inflated Poisson model to perform the test. Simulation studies show that when compared with the Vuong test our approach not only better at controlling type I error rate, but also yield more power.

  7. Testbeds for Assessing Critical Scenarios in Power Control Systems

    NASA Astrophysics Data System (ADS)

    Dondossola, Giovanna; Deconinck, Geert; Garrone, Fabrizio; Beitollahi, Hakem

    The paper presents a set of control system scenarios implemented in two testbeds developed in the context of the European Project CRUTIAL - CRitical UTility InfrastructurAL Resilience. The selected scenarios refer to power control systems encompassing information and communication security of SCADA systems for grid teleoperation, impact of attacks on inter-operator communications in power emergency conditions, impact of intentional faults on the secondary and tertiary control in power grids with distributed generators. Two testbeds have been developed for assessing the effect of the attacks and prototyping resilient architectures.

  8. The Zero Boil-Off Tank Experiment Contributions to the Development of Cryogenic Fluid Management

    NASA Technical Reports Server (NTRS)

    Chato, David J.; Kassemi, Mohammad

    2015-01-01

    The Zero Boil-Off Technology (ZBOT) Experiment involves performing a small scale ISS experiment to study tank pressurization and pressure control in microgravity. The ZBOT experiment consists of a vacuum jacketed test tank filled with an inert fluorocarbon simulant liquid. Heaters and thermo-electric coolers are used in conjunction with an axial jet mixer flow loop to study a range of thermal conditions within the tank. The objective is to provide a high quality database of low gravity fluid motions and thermal transients which will be used to validate Computational Fluid Dynamic (CFD) modeling. This CFD can then be used in turn to predict behavior in larger systems with cryogens. This paper will discuss the current status of the ZBOT experiment as it approaches its flight to installation on the International Space Station, how its findings can be scaled to larger and more ambitious cryogenic fluid management experiments, as well as ideas for follow-on investigations using ZBOT like hardware to study other aspects of cryogenic fluid management.

  9. Identification and Ranking of Critical Assets within an Electrical Grid under Threat of Cyber Attack

    NASA Astrophysics Data System (ADS)

    Boyer, Blake R.

    This paper examines the ranking of critical assets within an electrical grid under threat of cyber attack.1 Critical to this analysis is the assumption of zero hour exploits namely, the threat of an immediate attack as soon as a vulnerability is discovered. Modeling shows that over time load fluctuations as well as other system variations will change the importance of each asset in the delivery of bulk power. As opposed to classic stability studies where risk can be shown to be greatest during high load periods, the zero hour exploit-cyber-risk assumes that vulnerabilities will be attacked as soon as they are discovered. The probability of attacks is made uniform over time to include any and all possible attacks. Examining the impact of an attack and how the grid reacts immediately following an attack will identify and determine the criticality of each asset. This work endeavors to fulfill the NERC Critical Infrastructure Protection Requirements CIP-001-1 through CIP-009-2, cyber security requirements for the reliable supply of bulk power to customers throughout North America. 1Critical assets will here refer to facilities, systems, and equipment, which, if destroyed, degraded, or otherwise rendered unavailable, would affect the reliability or operability of the Bulk Electric System, NERC Glossary of Terms Used in Reliability Standards, 2009

  10. Lens Systems Incorporating A Zero Power Corrector Principle Of The Design And Its Application In Large Aperture, Moderate Field Of View Optical Systems

    NASA Astrophysics Data System (ADS)

    Klee, H. W.; McDowell, M. W.

    1986-02-01

    A new lens design concept, based on the use of a zero (or near zero) power corrector, will be described. The logical development of the design, based on the work of Schmidt', Houghton' and others will be discussed and examples will be given of moderate field of view lenses with apertures ranging from f/0.35 to f/2. It will also be shown that the lens configuration is relatively insensitive to the aperture stop location and that for less demanding applications only very basic optical glass types need be used.

  11. The Drag Coefficient of Parabolic Bodies of Revolution Operating at Zero Cavitation Number and Zero Angle of Yaw

    NASA Technical Reports Server (NTRS)

    Johnson, Virgil E., Jr.; Rasnick, Thomas A.

    1961-01-01

    The form-drag coefficient of parabolic bodies of revolution with fineness ratios greater than 1 operating at zero angle of yaw and zero cavitation number is determined both theoretically and experimentally. Agreement between theory and experiment is very good, The theoretical form-drag coefficient of paraboloids is about half the form-drag coefficient of cones of comparable fineness ratio.

  12. Client-nurse relationships in home-based palliative care: a critical analysis of power relations.

    PubMed

    Oudshoorn, Abram; Ward-Griffin, Catherine; McWilliam, Carol

    2007-08-01

    To elicit an in-depth understanding of the sources of power and how power is exercised within client-nurse relationships in home-based palliative care. As in all social relations, power is present within client-nurse relationships. Although much research has focused on interpersonal relationships in nursing, the concept of power within the client-nurse relationship in palliative care settings has not been extensively investigated. Applying a critical lens, secondary qualitative data analysis was conducted. Seventeen nurse and 16 client transcripts from a primary study were selected for secondary data analysis. These 33 transcripts afforded theme saturation, which allowed for both commonalities and differences to be identified. Data analysis involved analytic coding. Study findings help make explicit the underlying power present in the context of home-based palliative care and how this power is used and potentially abused. In analysing the sources and exercise of power, the linkage between macro and micro levels of power is made explicit, as nurses functioned within a hierarchy of power. The findings suggest that educational/occupational status continues to be a source of power for nurses within the relationship. However, nurses also experience powerlessness within the home care context. For clients, being able to control one's own life is a source of power, but this power is over-shadowed by the powerlessness experienced in relationships with nurses. The exercise of power by clients and nurses creates experiences of both liberation and domination. Nurses who are willing to reflect on and change those disempowering aspects of the client-nurse relationship, including a harmful hierarchy, will ultimately be successful in the health promotion of clients in home-based palliative care. Additionally, it should be recognized that nurses work within a specific health system context and, therefore, their practice is influenced by policies and funding models implemented at

  13. The power of a critical heat engine

    PubMed Central

    Campisi, Michele; Fazio, Rosario

    2016-01-01

    Since its inception about two centuries ago thermodynamics has sparkled continuous interest and fundamental questions. According to the second law no heat engine can have an efficiency larger than Carnot's efficiency. The latter can be achieved by the Carnot engine, which however ideally operates in infinite time, hence delivers null power. A currently open question is whether the Carnot efficiency can be achieved at finite power. Most of the previous works addressed this question within the Onsager matrix formalism of linear response theory. Here we pursue a different route based on finite-size-scaling theory. We focus on quantum Otto engines and show that when the working substance is at the verge of a second order phase transition diverging energy fluctuations can enable approaching the Carnot point without sacrificing power. The rate of such approach is dictated by the critical indices, thus showing the universal character of our analysis. PMID:27320127

  14. Splitting of the zero-energy Landau level and universal dissipative conductivity at critical points in disordered graphene.

    PubMed

    Ortmann, Frank; Roche, Stephan

    2013-02-22

    We report on robust features of the longitudinal conductivity (σ(xx)) of the graphene zero-energy Landau level in the presence of disorder and varying magnetic fields. By mixing an Anderson disorder potential with a low density of sublattice impurities, the transition from metallic to insulating states is theoretically explored as a function of Landau-level splitting, using highly efficient real-space methods to compute the Kubo conductivities (both σ(xx) and Hall σ(xy)). As long as valley degeneracy is maintained, the obtained critical conductivity σ(xx) =/~ 1.4e(2)/h is robust upon an increase in disorder (by almost 1 order of magnitude) and magnetic fields ranging from about 2 to 200 T. When the sublattice symmetry is broken, σ(xx) eventually vanishes at the Dirac point owing to localization effects, whereas the critical conductivities of pseudospin-split states (dictating the width of a σ(xy) = 0 plateau) change to σ(xx) =/~ e(2)/h, regardless of the splitting strength, superimposed disorder, or magnetic strength. These findings point towards the nondissipative nature of the quantum Hall effect in disordered graphene in the presence of Landau level splitting.

  15. Assessment and Selection of Competing Models for Zero-Inflated Microbiome Data

    PubMed Central

    Xu, Lizhen; Paterson, Andrew D.; Turpin, Williams; Xu, Wei

    2015-01-01

    Typical data in a microbiome study consist of the operational taxonomic unit (OTU) counts that have the characteristic of excess zeros, which are often ignored by investigators. In this paper, we compare the performance of different competing methods to model data with zero inflated features through extensive simulations and application to a microbiome study. These methods include standard parametric and non-parametric models, hurdle models, and zero inflated models. We examine varying degrees of zero inflation, with or without dispersion in the count component, as well as different magnitude and direction of the covariate effect on structural zeros and the count components. We focus on the assessment of type I error, power to detect the overall covariate effect, measures of model fit, and bias and effectiveness of parameter estimations. We also evaluate the abilities of model selection strategies using Akaike information criterion (AIC) or Vuong test to identify the correct model. The simulation studies show that hurdle and zero inflated models have well controlled type I errors, higher power, better goodness of fit measures, and are more accurate and efficient in the parameter estimation. Besides that, the hurdle models have similar goodness of fit and parameter estimation for the count component as their corresponding zero inflated models. However, the estimation and interpretation of the parameters for the zero components differs, and hurdle models are more stable when structural zeros are absent. We then discuss the model selection strategy for zero inflated data and implement it in a gut microbiome study of > 400 independent subjects. PMID:26148172

  16. Assessment and Selection of Competing Models for Zero-Inflated Microbiome Data.

    PubMed

    Xu, Lizhen; Paterson, Andrew D; Turpin, Williams; Xu, Wei

    2015-01-01

    Typical data in a microbiome study consist of the operational taxonomic unit (OTU) counts that have the characteristic of excess zeros, which are often ignored by investigators. In this paper, we compare the performance of different competing methods to model data with zero inflated features through extensive simulations and application to a microbiome study. These methods include standard parametric and non-parametric models, hurdle models, and zero inflated models. We examine varying degrees of zero inflation, with or without dispersion in the count component, as well as different magnitude and direction of the covariate effect on structural zeros and the count components. We focus on the assessment of type I error, power to detect the overall covariate effect, measures of model fit, and bias and effectiveness of parameter estimations. We also evaluate the abilities of model selection strategies using Akaike information criterion (AIC) or Vuong test to identify the correct model. The simulation studies show that hurdle and zero inflated models have well controlled type I errors, higher power, better goodness of fit measures, and are more accurate and efficient in the parameter estimation. Besides that, the hurdle models have similar goodness of fit and parameter estimation for the count component as their corresponding zero inflated models. However, the estimation and interpretation of the parameters for the zero components differs, and hurdle models are more stable when structural zeros are absent. We then discuss the model selection strategy for zero inflated data and implement it in a gut microbiome study of > 400 independent subjects.

  17. Nuclear event zero-time calculation and uncertainty evaluation.

    PubMed

    Pan, Pujing; Ungar, R Kurt

    2012-04-01

    It is important to know the initial time, or zero-time, of a nuclear event such as a nuclear weapon's test, a nuclear power plant accident or a nuclear terrorist attack (e.g. with an improvised nuclear device, IND). Together with relevant meteorological information, the calculated zero-time is used to help locate the origin of a nuclear event. The zero-time of a nuclear event can be derived from measured activity ratios of two nuclides. The calculated zero-time of a nuclear event would not be complete without an appropriately evaluated uncertainty term. In this paper, analytical equations for zero-time and the associated uncertainty calculations are derived using a measured activity ratio of two nuclides. Application of the derived equations is illustrated in a realistic example using data from the last Chinese thermonuclear test in 1980. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  18. Time delay of critical images in the vicinity of cusp point of gravitational-lens systems

    NASA Astrophysics Data System (ADS)

    Alexandrov, A.; Zhdanov, V.

    2016-12-01

    We consider approximate analytical formulas for time-delays of critical images of a point source in the neighborhood of a cusp-caustic. We discuss zero, first and second approximations in powers of a parameter that defines the proximity of the source to the cusp. These formulas link the time delay with characteristics of the lens potential. The formula of zero approximation was obtained by Congdon, Keeton & Nordgren (MNRAS, 2008). In case of a general lens potential we derived first order correction thereto. If the potential is symmetric with respect to the cusp axis, then this correction is identically equal to zero. For this case, we obtained second order correction. The relations found are illustrated by a simple model example.

  19. Zero-point term and quantum effects in the Johnson noise of resistors: a critical appraisal

    NASA Astrophysics Data System (ADS)

    Kish, Laszlo B.; Niklasson, Gunnar A.; Granqvist, Claes G.

    2016-05-01

    There is a longstanding debate about the zero-point term in the Johnson noise voltage of a resistor. This term originates from a quantum-theoretical treatment of the fluctuation-dissipation theorem (FDT). Is the zero-point term really there, or is it only an experimental artifact, due to the uncertainty principle, for phase-sensitive amplifiers? Could it be removed by renormalization of theories? We discuss some historical measurement schemes that do not lead to the effect predicted by the FDT, and we analyse new features that emerge when the consequences of the zero-point term are measured via the mean energy and force in a capacitor shunting the resistor. If these measurements verify the existence of a zero-point term in the noise, then two types of perpetual motion machines can be constructed. Further investigation with the same approach shows that, in the quantum limit, the Johnson-Nyquist formula is also invalid under general conditions even though it is valid for a resistor-antenna system. Therefore we conclude that in a satisfactory quantum theory of the Johnson noise, the FDT must, as a minimum, include also the measurement system used to evaluate the observed quantities. Issues concerning the zero-point term may also have implications for phenomena in advanced nanotechnology.

  20. Hospital nurses' lived experience of power.

    PubMed

    Fackler, Carol A; Chambers, Angelina N; Bourbonniere, Meg

    2015-05-01

    The purpose of this study was to explore hospital nurses' lived experience of power. A hermeneutic phenomenological approach informed by Merleau-Ponty's philosophy of the phenomenology of perception was used to further an understanding of nurses' embodiment of power. Fourteen hospital clinical nurses employed in intensive care units and on medical floors in two major medical centers in the northeastern United States participated in 1-hr semistructured interviews about their lived experience of power. A hermeneutic analytic approach and reflexive (cultural) bracketing produced three relational themes of power: (a) knowing my patients and speaking up for them; (b) working to build relationships that benefit patients; and (c) identifying my powerful self. Hospital clinical nurses develop a sense of power. Nurses believe power develops through acquisition of knowledge, experience, and self-confidence; this process is enhanced by exposure to good mentors. Nurses use their power to build relationships and advocate for patients. They consciously use power to improve patient care. Nurses' voices need to be heard and acknowledged. To do this in the clinical setting and beyond, hospital nurses must invite themselves or find ways to be invited into the authoritative discourse of hospital organizations. Nurses use their power to advocate for positive outcomes for patients and families. The satisfaction that comes from these positive relationships may improve nurses' perceptions of their work environment. Nurses' understanding and use of sociopolitical knowing needs further study, so that nurses may understand how to participate in current and future debates and decisions about our changing healthcare delivery systems and services. © 2015 Sigma Theta Tau International.

  1. Zero absolute vorticity: insight from experiments in rotating laminar plane Couette flow.

    PubMed

    Suryadi, Alexandre; Segalini, Antonio; Alfredsson, P Henrik

    2014-03-01

    For pressure-driven turbulent channel flows undergoing spanwise system rotation, it has been observed that the absolute vorticity, i.e., the sum of the averaged spanwise flow vorticity and system rotation, tends to zero in the central region of the channel. This observation has so far eluded a convincing theoretical explanation, despite experimental and numerical evidence reported in the literature. Here we show experimentally that three-dimensional laminar structures in plane Couette flow, which appear under anticyclonic system rotation, give the same effect, namely, that the absolute vorticity tends to zero if the rotation rate is high enough. It is shown that this is equivalent to a local Richardson number of approximately zero, which would indicate a stable condition. We also offer an explanation based on Kelvin's circulation theorem to demonstrate that the absolute vorticity should remain constant and approximately equal to zero in the central region of the channel when going from the nonrotating fully turbulent state to any state with sufficiently high rotation.

  2. Analysis of failure and maintenance experiences of motor operated valves in a Finnish nuclear power plant

    NASA Astrophysics Data System (ADS)

    Simola, Kaisa; Laakso, Kari

    1992-01-01

    Eight years of operating experiences of 104 motor operated closing valves in different safety systems in nuclear power units were analyzed in a systematic way. The qualitative methods used were Failure Mode and Effect Analysis (FMEA) and Maintenance Effects and Criticality Analysis (MECA). These reliability engineering methods are commonly used in the design stage of equipment. The successful application of these methods for analysis and utilization of operating experiences was demonstrated.

  3. Numerical Predictions of Wind Turbine Power and Aerodynamic Loads for the NREL Phase II and IV Combined Experiment Rotor

    NASA Technical Reports Server (NTRS)

    Duque, Earl P. N.; Johnson, Wayne; vanDam, C. P.; Chao, David D.; Cortes, Regina; Yee, Karen

    1999-01-01

    Accurate, reliable and robust numerical predictions of wind turbine rotor power remain a challenge to the wind energy industry. The literature reports various methods that compare predictions to experiments. The methods vary from Blade Element Momentum Theory (BEM), Vortex Lattice (VL), to variants of Reynolds-averaged Navier-Stokes (RaNS). The BEM and VL methods consistently show discrepancies in predicting rotor power at higher wind speeds mainly due to inadequacies with inboard stall and stall delay models. The RaNS methodologies show promise in predicting blade stall. However, inaccurate rotor vortex wake convection, boundary layer turbulence modeling and grid resolution has limited their accuracy. In addition, the inherently unsteady stalled flow conditions become computationally expensive for even the best endowed research labs. Although numerical power predictions have been compared to experiment. The availability of good wind turbine data sufficient for code validation experimental data that has been extracted from the IEA Annex XIV download site for the NREL Combined Experiment phase II and phase IV rotor. In addition, the comparisons will show data that has been further reduced into steady wind and zero yaw conditions suitable for comparisons to "steady wind" rotor power predictions. In summary, the paper will present and discuss the capabilities and limitations of the three numerical methods and make available a database of experimental data suitable to help other numerical methods practitioners validate their own work.

  4. Enhancement cavities for zero-offset-frequency pulse trains.

    PubMed

    Holzberger, S; Lilienfein, N; Trubetskov, M; Carstens, H; Lücking, F; Pervak, V; Krausz, F; Pupeza, I

    2015-05-15

    The optimal enhancement of broadband optical pulses in a passive resonator requires a seeding pulse train with a specific carrier-envelope-offset frequency. Here, we control the phase of the cavity mirrors to tune the offset frequency for which a given comb is optimally enhanced. This enables the enhancement of a zero-offset-frequency train of sub-30-fs pulses to multi-kW average powers. The combination of pulse duration, power, and zero phase slip constitutes a crucial step toward the generation of attosecond pulses at multi-10-MHz repetition rates. In addition, this control affords the enhancement of pulses generated by difference-frequency mixing, e.g., for mid-infrared spectroscopy.

  5. Using Scatterplots to Teach the Critical Power Concept

    ERIC Educational Resources Information Center

    Pettitt, Robert W.

    2012-01-01

    The critical power (CP) concept has received renewed attention and excitement in the academic community. The CP concept was originally conceived as a model derived from a series of exhaustive, constant-load, exercise bouts. All-out exercise testing has made quantification of the parameters for the two-component model easier to arrive at, which may…

  6. Advanced Fuel Cycles for Fusion Reactors: Passive Safety and Zero-Waste Options

    NASA Astrophysics Data System (ADS)

    Zucchetti, Massimo; Sugiyama, Linda E.

    2006-05-01

    Nuclear fusion is seen as a much ''cleaner'' energy source than fission. Most of the studies and experiments on nuclear fusion are currently devoted to the Deuterium-Tritium (DT) fuel cycle, since it is the easiest way to reach ignition. The recent stress on safety by the world's community has stimulated the research on other fuel cycles than the DT one, based on 'advanced' reactions, such as the Deuterium-Helium-3 (DHe) one. These reactions pose problems, such as the availability of 3He and the attainment of the higher plasma parameters that are required for burning. However, they have many advantages, like for instance the very low neutron activation, while it is unnecessary to breed and fuel tritium. The extrapolation of Ignitor technologies towards a larger and more powerful experiment using advanced fuel cycles (Candor) has been studied. Results show that Candor does reach the passive safety and zero-waste option. A fusion power reactor based on the DHe cycle could be the ultimate response to the environmental requirements for future nuclear power plants.

  7. Integrated application of combined cooling, heating and power poly-generation PV radiant panel system of zero energy buildings

    NASA Astrophysics Data System (ADS)

    Yin, Baoquan

    2018-02-01

    A new type of combined cooling, heating and power of photovoltaic radiant panel (PV/R) module was proposed, and applied in the zero energy buildings in this paper. The energy system of this building is composed of PV/R module, low temperature difference terminal, energy storage, multi-source heat pump, energy balance control system. Radiant panel is attached on the backside of the PV module for cooling the PV, which is called PV/R module. During the daytime, the PV module was cooled down with the radiant panel, as the temperature coefficient influence, the power efficiency was increased by 8% to 14%, the radiant panel solar heat collecting efficiency was about 45%. Through the nocturnal radiant cooling, the PV/R cooling capacity could be 50 W/m2. For the multifunction energy device, the system shows the versatility during the heating, cooling and power used of building utilization all year round.

  8. Zero-order release of poorly water-soluble drug from polymeric films made via aqueous slurry casting.

    PubMed

    Zhang, Lu; Alfano, Joy; Race, Doran; Davé, Rajesh N

    2018-05-30

    In spite of significant recent interest in polymeric films containing poorly water-soluble drugs, dissolution mechanism of thicker films has not been investigated. Consequently, release mechanisms of poorly water-soluble drugs from thicker hydroxypropyl methylcellulose (HPMC) films are investigated, including assessing thickness above which they exhibit zero-order drug release. Micronized, surface modified particles of griseofulvin, a model drug of BSC class II, were incorporated into aqueous slurry-cast films of different thicknesses (100, 500, 1000, 1500 and 2000 μm). Films 1000 μm and thicker were formed by either stacking two or more layers of ~500 μm, or forming a monolithic thick film. Compared to monolithic thick films, stacked films required simpler manufacturing process (easier casting, short drying time) and resulted in better critical quality attributes (appearance, uniformity of thickness and drug per unit area). Both the film forming approaches exhibited similar release profiles and followed the semi-empirical power law. As thickness increased from 100 μm to 2000 μm, the release mechanism changed from Fickian diffusion to zero-order release for films ≥1000 μm. The diffusional power law exponent, n, achieved value of 1, confirming zero-order release, whereas the percentage drug release varied linearly with sample surface area, and sample thickness due to fixed sample diameter. Thus, multi-layer hydrophilic polymer aqueous slurry-cast thick films containing poorly water-soluble drug particles provide a convenient dosage form capable of zero-order drug release with release time modulated through number of layers. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Tokamak power reactor ignition and time dependent fractional power operation

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

    Vold, E.L.; Mau, T.K.; Conn, R.W.

    1986-06-01

    A flexible time-dependent and zero-dimensional plasma burn code with radial profiles was developed and employed to study the fractional power operation and the thermal burn control options for an INTOR-sized tokamak reactor. The code includes alpha thermalization and a time-dependent transport loss which can be represented by any one of several currently popular scaling laws for energy confinement time. Ignition parameters were found to vary widely in density-temperature (n-T) space for the range of scaling laws examined. Critical ignition issues were found to include the extent of confinement time degradation by alpha heating, the ratio of ion to electron transportmore » power loss, and effect of auxiliary heating on confinement. Feedback control of the auxiliary power and ion fuel sources are shown to provide thermal stability near the ignition curve.« less

  10. A Geophysical Flow Experiment in a Compressible Critical Fluid

    NASA Technical Reports Server (NTRS)

    Hegseth, John; Garcia, Laudelino

    1996-01-01

    The first objective of this experiment is to build an experimental system in which, in analogy to a geophysical system, a compressible fluid in a spherical annulus becomes radially stratified in density through an A.C. electric field. When this density gradient is demonstrated, the system will be augmented so that the fluid can be driven by heating and rotation and tested in preparation for a microgravity experiment. This apparatus consists of a spherical capacitor filled with critical fluid in a temperature controlled environment. To make the fluid critical, the apparatus will be operated near the critical pressure, critical density, and critical temperature of the fluid. This will result in a highly compressible fluid because of the properties of the fluid near its critical point. A high voltage A.C. source applied across the capacitor will create a spherically symmetric central force because of the dielectric properties of the fluid in an electric field gradient. This central force will induce a spherically symmetric density gradient that is analogous to a geophysical fluid system. To generate such a density gradient the system must be small (approx. 1 inch diameter). This small cell will also be capable of driving the critical fluid by heating and rotation. Since a spherically symmetric density gradient can only be made in microgravity, another small cell, of the same geometry, will be built that uses incompressible fluid. The driving of the fluid by rotation and heating in these small cells will be developed. The resulting instabilities from the driving in these two systems will then be studied. The second objective is to study the pattern forming instabilities (bifurcations) resulting from the well controlled experimental conditions in the critical fluid cell. This experiment will come close to producing conditions that are geophysically similar and will be studied as the driving parameters are changed.

  11. An experimental and analytical investigation of thermoacoustic convection heat transfer in gravity and zero-gravity environments

    NASA Technical Reports Server (NTRS)

    Parang, Masood

    1986-01-01

    An experimental and analytical study of Thermoacoustic Convection heat transfer in gravity and zero-gravity environments is presented. The experimental apparatus consisted of a cylinder containing air as a fluid. The side wall of the cylinder was insulated while the bottom wall was allowed to remain at the ambient temperature. The enclosed air was rapidly heated by the top surface which consisted of a thin stainless steel foil connected to a battery pack as the power source. Thermocouples were used to measure the transient temperature of the air on the axis of the cylinder. The ouput of the thermocouples was displayed on digital thermometers and the temperature displays were recorded on film using a high-speed movie camera. Temperature measurements were obtained in the zero-gravity environment by dropping the apparatus in the 2-Seconds Zero-Gravity Drop Tower Facilities of NASA Lewis Research Center. In addition, experiments were also performed in the gravity environment and the results are compared in detail with those obtained under zero-gravity conditions.

  12. Topographies of Power: A Critical Historical Geography of Schooling in Tanzania

    ERIC Educational Resources Information Center

    Vavrus, Frances

    2016-01-01

    This article builds a case for critical historical geography in comparative education to examine how, over time, the social production of space contributes to educational disparity. It draws on Gupta and Ferguson's contrasting concepts of the "power of topography" and the "topography of power" and Lefebvre's tripartite theory…

  13. Analytical investigation of critical phenomena in MHD power generators

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

    Not Available

    1980-07-31

    Critical phenomena in the Arnold Engineering Development Center (AEDC) High Performance Demonstration Experiment (HPDE) and the US U-25 Experiment, are analyzed. Also analyzed are the performance of a NASA-specified 500 MW(th) flow train and computations concerning critica issues for the scale-up of MHD Generators. The HPDE is characterized by computational simulations of both the nominal conditions and the conditions during the experimental runs. The steady-state performance is discussed along with the Hall voltage overshoots during the start-up and shutdown transients. The results of simulations of the HPDE runs with codes from the Q3D and TRANSIENT code families are compared tomore » the experimental results. The results of the simulations are in good agreement with the experimental data. Additional critica phenomena analyzed in the AEDC/HPDE are the optimal load schedules, parametric variations, the parametric dependence of the electrode voltage drops, the boundary layer behavior, near electrode phenomena with finite electrode segmentation, and current distribution in the end regions. The US U-25 experiment is characterized by computational simulations of the nominal operating conditions. The steady-state performance for the nominal design of the US U-25 experiment is analyzed, as is the dependence of performance on the mass flow rate. A NASA-specified 500 MW(th) MHD flow train is characterized for computer simulation and the electrical, transport, and thermodynamic properties at the inlet plane are analyzed. Issues for the scale-up of MHD power trains are discussed. The AEDC/HPDE performance is analyzed to compare these experimental results to scale-up rules.« less

  14. Trust, choice and power in mental health care: experiences of patients with psychosis.

    PubMed

    Laugharne, Richard; Priebe, Stefan; McCabe, Rose; Garland, Natasha; Clifford, Damian

    2012-09-01

    Trust, choice and power are critical issues in clinical practice, public policies and a post-modern understanding of mental health care. We aimed to investigate the experiences and attitudes of patients with psychosis in relation to trust, choice and power. We conducted 20 in-depth interviews with patients with psychotic disorders in care of NHS services. The interviews were subjected to thematic analysis. Patients discussed aspects of their care in terms of dimensions that enhance or undermine trust, choice and power. Two interpretive themes emerged from this data. First, patients perceive the need for a shifting balance of power, according to the severity of their illness and their own experience of care, but feel that threats of coercion and neglect disable them. Second, they appreciate the expertise of clinicians, but particularly value 'the personal touch' that goes beyond this expertise, including personal disclosure about their own lives, common acts of kindness and conversation outside clinical matters. Patients view trust as a two-way process with responsibility shared between patient and clinician. The active involvement of patients with psychosis in their individual care may be strengthened, particularly when they are not acutely ill and have more experience of their illness. While patients value expertise and respect in interactions with clinicians, they also appreciate a 'personal touch', which may go beyond current notions of professionalism.

  15. RHIC BEAM ABORT KICKER POWER SUPPLY SYSTEM COMMISSIONING EXPERIENCE AND REMAINING ISSUES.

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

    ZHANG,W.; AHRENS,L.A.; MI,J.

    2001-06-18

    The RHIC Beam Abort Kicker Power Supply Systems commissioning experience and the remaining issues will be reported in this paper. The RHIC Blue Ring Beam Abort Kicker Power Supply System initial commissioning took place in June 1999. Its identical system in Yellow Ring was brought on line during Spring 2000. Each of the RHIC Beam Abort Kicker Power Supply Systems consists of five high voltage modulators and subsystems. These systems are critical devices for RHIC machine protection and environmental protection. They are required to be effective, reliable and operating with sufficient redundancy to safely abort the beam to its beammore » dump at the end of accumulation or at any time when they are commanded. To deflect 66 GeV ion beam to the beam absorbers, the RHIC Beam Abort Kicker Power Supply Systems were operated at 22 kV level. The RHIC 2000 commissioning run was very successful.« less

  16. A novel concentrator with zero-index metamaterial for space solar power station

    NASA Astrophysics Data System (ADS)

    Huang, Jin; Chu, Xue-mei; Fan, Jian-yu; Jin, Qi-bao; Duan, Zhu-zhu

    2017-03-01

    Space solar power station (SSPS) is a comprehensive system that continuously collects solar energy in space and transmits it to ground with a wireless power transmission (WPT) system. These systems have great potential to provide large-scale energy. To increase the efficiency and reduce the weight and cost of the photovoltaic (PV) components, a huge light-weighted concentrator was introduced in the latest SSPS concepts, such as integrated symmetrical concentrator (ISC) and arbitrarily large phased array (ALPHA). However, for typical SSPS running in Geostationary Earth Orbit (GEO), the sunlight direction varies with time, leading to a great challenge for concentrator design. In ISC, the two-dimensional mast is used to realize sun-tracking. However, a multi-thousand-ton structure is difficult to control precisely in space. For this reason, ALPHA comprises a large number of individually pointed thin-film reflectors to intercept sunlight, mounted on the non-moving structure. However, the real-time adjustment of the thousands of reflectors is still an open problem. Furthermore, the uniformity of the time of the power generation (UTPG) is another factor evaluating the system. Therefore, this paper proposes a novel concentrator based on zero-index metamaterial (ZIM) called Thin-film Energy Terminator (SSPS-TENT). This will aid the control of the massive reflectors while avoiding the rotation of the overall system, the control of the massive reflectors and the influence of the obliquity of the ecliptic. Also, an optimization design method is proposed to increase its solar energy collecting efficiency (ECE) and flux distribution (FD). The ray-tracing simulation results show that the ECE is more than 96% of the day. In terms of the FD, the uniformity varies from 0.3057 to 0.5748. Compared with ALPHA, the UTPG is more stable.

  17. Feasibility of zero or near zero fluoroscopy during catheter ablation procedures.

    PubMed

    Haegeli, Laurent M; Stutz, Linda; Mohsen, Mohammed; Wolber, Thomas; Brunckhorst, Corinna; On, Chol-Jun; Duru, Firat

    2018-04-03

    Awareness of risks associated with radiation exposure to patients and medical staff has significantly increased. It has been reported before that the use of advanced three-dimensional electro-anatomical mapping (EAM) system significantly reduces fluoroscopy time, however this study aimed for zero or near zero fluoroscopy ablation to assess its feasibility and safety in ablation of atrial fibrillation (AF) and other tachyarrhythmias in a "real world" experience of a single tertiary care center. This was a single-center study where ablation procedures were attempted without fluoroscopy in 34 consecutive patients with different tachyarrhythmias under the support of EAM system. When transseptal puncture (TSP) was needed, it was attempted under the guidance of intracardiac echocardiography (ICE). Among 34 patients consecutively enrolled in this study, 28 (82.4%) patients were referred for radiofrequency ablation (RFA) of AF, 3 (8.8%) patients for ablation of right ventricular outflow tract (RVOT) ventricular extrasystole (VES), 1 (2.9%) patient for ablation of atrioventricular nodal reentry tachycardia (AVNRT), 2 (5.9%) patients for typical atrial flutter ablation. In 21 (62%) patients the entire procedure was carried out without the use of fluoroscopy. Among 28 AF patients, 15 (54%) patients underwent ablation without the use of fluoroscopy and among these 15 patients, 10 (67%) patients required TSP under ICE guidance while 5 (33%) patients the catheters were introduced to left atrium through a patent foramen ovale. In 13 AF patients, fluoroscopy was only required for double TSP. The total procedure time of AF ablation was 130 ± 50 min. All patients referred for atrial flutter, AVNRT, and VES of the RVOT ablation did not require any fluoroscopy. This study demonstrates the feasibility of zero or near zero fluoroscopy procedure including TSP with the support of EAM and ICE guidance in a "real world" experience of a single tertiary care center. When fluoroscopy was

  18. Field-Reversed Configuration Power Plant Critical-Issue Scoping Study

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

    Santarius, J. F.; Mogahed, E. A.; Emmert, G. A.

    A team from the Universities of Wisconsin, Washington, and Illinois performed an engineering scoping study of critical issues for field-reversed configuration (FRC) power plants. The key tasks for this research were (1) systems analysis for deuterium-tritium (D-T) FRC fusion power plants, and (2) conceptual design of the blanket and shield module for an FRC fusion core. For the engineering conceptual design of the fusion core, the project team focused on intermediate-term technology. For example, one decision was to use steele structure. The FRC systems analysis led to a fusion power plant with attractive features including modest size, cylindrical symmetry, goodmore » thermal efficiency (52%), relatively easy maintenance, and a high ratio of electric power to fusion core mass, indicating that it would have favorable economics.« less

  19. A collection of articles on S/X-band experiment zero delay ranging tests, volume 1

    NASA Technical Reports Server (NTRS)

    Otoshi, T. Y. (Editor)

    1975-01-01

    Articles are presented which are concerned with the development of special test equipment and a dual-frequency zero delay device (ZDD) that were required for range tests and the measurement of ground station delays for the Mariner-Venus-Mercury 1973 S/X-band experiment. Test data obtained at DSS 14 after installation of the ZDD on the 64-m antenna are given. It is shown that large variations of range were observed as a function of antenna elevation angle and were sensitive to antenna location. A ranging calibration configuration that was subsequently developed and a technique for determining the appropriate Z-correction are described. Zero delay test data at DSS 14 during the Mariner 10 Venus-Mercury-Encounter periods (1974 days 12-150) are presented. The theoretical analysis and experimental verifications are included of the effects of multipath and effects of discontinuities on range delay measurements. A movable subreflector technique and the multipath theory were used to isolate principal multipath errors on the 64-m antenna and to enable a more accurate determination of the actual ground station range delay.

  20. Energy of the quasi-free electron in supercritical krypton near the critical point.

    PubMed

    Li, Luxi; Evans, C M; Findley, G L

    2005-12-01

    Field ionization measurements of high-n CH(3)I and C(2)H(5)I Rydberg states doped into krypton are presented as a function of krypton number density along the critical isotherm. These data exhibit a decrease in the krypton-induced shift of the dopant ionization energy near the critical point. This change in shift is modeled to within +/-0.2% of experiment using a theory that accounts for the polarization of krypton by the dopant ion, the polarization of krypton by the quasi-free electron that arises from field ionization of the dopant, and the zero point kinetic energy of the free electron. The overall decrease in the shift of the dopant ionization energy near the critical point of krypton, which is a factor of 2 larger than that observed in argon, is dominated by the increase in the zero point kinetic energy of the quasi-free electron.

  1. Density of states, Potts zeros, and Fisher zeros of the Q

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

    Kim, Seung-Yeon; Creswick, Richard J.

    2001-06-01

    The Q-state Potts model can be extended to noninteger and even complex Q by expressing the partition function in the Fortuin-Kasteleyn (F-K) representation. In the F-K representation the partition function Z(Q,a) is a polynomial in Q and v=a{minus}1 (a=e{sup {beta}J}) and the coefficients of this polynomial, {Phi}(b,c), are the number of graphs on the lattice consisting of b bonds and c connected clusters. We introduce the random-cluster transfer matrix to compute {Phi}(b,c) exactly on finite square lattices with several types of boundary conditions. Given the F-K representation of the partition function we begin by studying the critical Potts model Z{submore » CP}=Z(Q,a{sub c}(Q)), where a{sub c}(Q)=1+{radical}Q. We find a set of zeros in the complex w={radical}Q plane that map to (or close to) the Beraha numbers for real positive Q. We also identify {tilde Q}{sub c}(L), the value of Q for a lattice of width L above which the locus of zeros in the complex p=v/{radical}Q plane lies on the unit circle. By finite-size scaling we find that 1/{tilde Q}{sub c}(L){r_arrow}0 as L{r_arrow}{infinity}. We then study zeros of the antiferromagnetic (AF) Potts model in the complex Q plane and determine Q{sub c}(a), the largest value of Q for a fixed value of a below which there is AF order. We find excellent agreement with Baxter{close_quote}s conjecture Q{sub c}{sup AF}(a)=(1{minus}a)(a+3). We also investigate the locus of zeros of the ferromagnetic Potts model in the complex Q plane and confirm that Q{sub c}{sup FM}(a)=(a{minus}1){sup 2}. We show that the edge singularity in the complex Q plane approaches Q{sub c} as Q{sub c}(L){similar_to}Q{sub c}+AL{sup {minus}y{sub q}}, and determine the scaling exponent y{sub q} for several values of Q. Finally, by finite-size scaling of the Fisher zeros near the antiferromagnetic critical point we determine the thermal exponent y{sub t} as a function of Q in the range 2{le}Q{le}3. Using data for lattices of size 3{le}L{le}8 we find

  2. Sediment-transport (wind) experiments in zero-gravity

    NASA Technical Reports Server (NTRS)

    Iverson, J.; Gillette, D.; Greeley, R.; Lee, J.; Mackinnon, I.; Marshall, J.; Nickling, W.; Werner, B.; White, B.; Williams, S.

    1986-01-01

    The carousel wind tunnel (CWT) can be a significant tool for the determination of the nature and magnitude of interparticlar forces at threshold of motion. By altering particle and drum surface electrical properties and/or by applying electric potential difference across the inner and outer drums, it should be possible to separate electrostatic effects from other forces of cohesion. Besides particle trajectory and bedform analyses, suggestions for research include particle aggregation in zero and subgravity environments, effect of suspension-saltation ratio on soil abrasion, and the effects of shear and shearfree turbulence on particle aggregation as applied to evolution of solar nebula.

  3. Characterizing the ear canal acoustic reflectance and impedance by pole-zero fitting

    PubMed Central

    Robinson, Sarah R.; Nguyen, Cac T.; Allen, Jont B.

    2013-01-01

    This study characterizes middle ear complex acoustic reflectance (CAR) and impedance by fitting poles and zeros to real-ear measurements. The goal of this work is to establish a quantitative connection between pole-zero locations and the underlying physical properties of CAR data. Most previous studies have analyzed CAR magnitude; while the magnitude accounts for reflected power, it does not encode latency information. Thus, an analysis that studies the real and imaginary parts of the data together could be more powerful. Pole-zero fitting of CAR data is examined using data compiled from various studies, dating back to Voss and Allen (1994). Recent CAR measurements were taken using a middle ear acoustic power analyzer (MEPA) system (HearID, Mimosa Acoustics), which makes complex acoustic impedance and reflectance measurements in the ear canal over the 0.2 to 6.0 kHz frequency range. Pole-zero fits to measurements over this range are achieved with an average RMS relative error of less than 3% using 12 poles. Factoring the reflectance fit into its all-pass and minimum-phase components approximates the effect of the ear canal, allowing for comparison across measurements. It was found that individual CAR magnitude variations for normal middle ears in the 1 to 4 kHz range often give rise to closely-placed pole-zero pairs, and that the locations of the poles and zeros in the s-plane may differ between normal and pathological middle ears. This study establishes a methodology for examining the physical and mathematical properties of CAR using a concise parametric model. Pole-zero modeling shows promise for precise parameterization of CAR data and for identification of middle ear pathologies. PMID:23524141

  4. Three-Dimensional Printing in Zero Gravity

    NASA Technical Reports Server (NTRS)

    Werkheiser, Niki

    2015-01-01

    The 3D printing in zero-g (3D Print) technology demonstration project is a proof-of-concept test designed to assess the properties of melt deposition modeling additive manufacturing in the microgravity environment experienced on the International Space Station (ISS). This demonstration is the first step towards realizing a 'machine shop' in space, a critical enabling component of any deep space mission.

  5. Sparse Zero-Sum Games as Stable Functional Feature Selection

    PubMed Central

    Sokolovska, Nataliya; Teytaud, Olivier; Rizkalla, Salwa; Clément, Karine; Zucker, Jean-Daniel

    2015-01-01

    In large-scale systems biology applications, features are structured in hidden functional categories whose predictive power is identical. Feature selection, therefore, can lead not only to a problem with a reduced dimensionality, but also reveal some knowledge on functional classes of variables. In this contribution, we propose a framework based on a sparse zero-sum game which performs a stable functional feature selection. In particular, the approach is based on feature subsets ranking by a thresholding stochastic bandit. We provide a theoretical analysis of the introduced algorithm. We illustrate by experiments on both synthetic and real complex data that the proposed method is competitive from the predictive and stability viewpoints. PMID:26325268

  6. The Relationships of Critical Thinking Skills, Critical Thinking Dispositions, and College Experiences of Theological Students in Indonesia

    ERIC Educational Resources Information Center

    Soeherman, Sylvia

    2010-01-01

    The purposes of this study were to assess the critical thinking skills of theological students in Indonesia and to explore the relationships between these students' critical thinking skills and their demographic profiles, critical thinking dispositions, and college experiences. All third-year students who pursued either the Sarjana Theologi (a…

  7. Frozen-wave instability in near-critical hydrogen subjected to horizontal vibration under various gravity fields.

    PubMed

    Gandikota, G; Chatain, D; Amiroudine, S; Lyubimova, T; Beysens, D

    2014-01-01

    The frozen-wave instability which appears at a liquid-vapor interface when a harmonic vibration is applied in a direction tangential to it has been less studied until now. The present paper reports experiments on hydrogen (H2) in order to study this instability when the temperature is varied near its critical point for various gravity levels. Close to the critical point, a liquid-vapor density difference and surface tension can be continuously varied with temperature in a scaled, universal way. The effect of gravity on the height of the frozen waves at the interface is studied by performing the experiments in a magnetic facility where effective gravity that results from the coupling of the Earth's gravity and magnetic forces can be varied. The stability diagram of the instability is obtained. The experiments show a good agreement with an inviscid model [Fluid Dyn. 21 849 (1987)], irrespective of the gravity level. It is observed in the experiments that the height of the frozen waves varies weakly with temperature and increases with a decrease in the gravity level, according to a power law with an exponent of 0.7. It is concluded that the wave height becomes of the order of the cell size as the gravity level is asymptotically decreased to zero. The interface pattern thus appears as a bandlike pattern of alternate liquid and vapor phases, a puzzling phenomenon that was observed with CO2 and H2 near their critical point in weightlessness [Acta Astron. 61 1002 (2007); Europhys. Lett. 86 16003 (2009)].

  8. Zero-field magnetic response functions in Landau levels

    PubMed Central

    Gao, Yang; Niu, Qian

    2017-01-01

    We present a fresh perspective on the Landau level quantization rule; that is, by successively including zero-field magnetic response functions at zero temperature, such as zero-field magnetization and susceptibility, the Onsager’s rule can be corrected order by order. Such a perspective is further reinterpreted as a quantization of the semiclassical electron density in solids. Our theory not only reproduces Onsager’s rule at zeroth order and the Berry phase and magnetic moment correction at first order but also explains the nature of higher-order corrections in a universal way. In applications, those higher-order corrections are expected to curve the linear relation between the level index and the inverse of the magnetic field, as already observed in experiments. Our theory then provides a way to extract the correct value of Berry phase as well as the magnetic susceptibility at zero temperature from Landau level fan diagrams in experiments. Moreover, it can be used theoretically to calculate Landau levels up to second-order accuracy for realistic models. PMID:28655849

  9. JPL solar power experiments

    NASA Technical Reports Server (NTRS)

    Yasui, R. K.

    1976-01-01

    Report describes evolution of photovoltaic power systems designed and built for terrestrial use. Discussion focuses on technological problems impeding further systems development. Experiments and test data on seven types of solar panels and six material test specimens are described in detail.

  10. A synthetic zero air standard

    NASA Astrophysics Data System (ADS)

    Pearce, Ruth

    2016-04-01

    A Synthetic Zero Air Standard R. E. Hill-Pearce, K. V. Resner, D. R. Worton, P. J. Brewer The National Physical Laboratory Teddington, Middlesex TW11 0LW UK We present work towards providing traceability for measurements of high impact greenhouse gases identified by the World Meteorological Organisation (WMO) as critical for global monitoring. Standards for these components are required with challengingly low uncertainties to improve the quality assurance and control processes used for the global networks to better assess climate trends. Currently the WMO compatibility goals require reference standards with uncertainties of < 100 nmolmol-1 for CO2 (northern hemisphere) and < 2 nmolmol-1 for CH4 and CO. High purity zero gas is required for both the balance gas in the preparation of reference standards and for baseline calibrations of instrumentation. Quantification of the amount fraction of the target components in the zero gas is a significant contributor to the uncertainty and is challenging due to limited availability of reference standard at the amount fraction of the measurand and limited analytical techniques with sufficient detection limits. A novel dilutor was used to blend NPL Primary Reference Gas Mixtures containing CO2, CH4 and CO at atmospheric amount fractions with a zero gas under test. Several mixtures were generated with nominal dilution ratios ranging from 2000:1 to 350:1. The baseline of two cavity ring down spectrometers was calibrated using the zero gas under test after purification by oxidative removal of CO and hydrocarbons to < 1 nmolmol-1 (SAES PS15-GC50) followed by the removal of CO2 and water vapour to < 100 pmolmol-1 (SAES MC190). Using the standard addition method.[1] we have quantified the amount fraction of CO, CO2, and CH4 in scrubbed whole air (Scott Marrin) and NPL synthetic zero air. This is the first synthetic zero air standard with a matrix of N2, O2 and Ar closely matching ambient composition with gravimetrically assigned

  11. Battery Power Management in Heavy-duty HEVs based on the Estimated Critical Surface Charge

    DTIC Science & Technology

    2011-03-01

    health prospects without any penalty on fuel efficiency. Keywords: Lithium - ion battery ; power management; critical surface charge; Lithium-ion...fuel efficiency. 15. SUBJECT TERMS Lithium - ion battery ; power management; critical surface charge; Lithium-ion concentration; estimation; extended...Di Domenico, D., Fiengo, G., and Stefanopoulou, A. (2008) ’ Lithium - ion battery state of charge estimation with a kalman filter based on a

  12. Determination of Absolute Zero Using a Computer-Based Laboratory

    ERIC Educational Resources Information Center

    Amrani, D.

    2007-01-01

    We present a simple computer-based laboratory experiment for evaluating absolute zero in degrees Celsius, which can be performed in college and undergraduate physical sciences laboratory courses. With a computer, absolute zero apparatus can help demonstrators or students to observe the relationship between temperature and pressure and use…

  13. Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    KSC employees, along with Center Director Roy Bridges (second from left), view the hydrogen-oxygen driven engine powering a Zero Emissions (ZE) transit bus. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. Available for viewing by employees, the ZE bus is also being used on tour routes at the KSC Visitor Complex Oct. 26-27.

  14. Experimental detailed power distribution in a fast spectrum thermionic reactor fuel element at the core/BeO reflector interface region

    NASA Technical Reports Server (NTRS)

    Klann, P. G.; Lantz, E.

    1973-01-01

    A zero-power critical assembly was designed, constructed, and operated for the prupose of conducting a series of benchmark experiments dealing with the physics characteristics of a UN-fueled, Li-7-cooled, Mo-reflected, drum-controlled compact fast reactor for use with a space-power conversion system. The critical assembly was modified to simulate a fast spectrum advanced thermionics reactor by: (1) using BeO as a reflector in place of some of the existing molybdenum, (2) substituting Nb-1Zr tubing for some of the existing Ta tubing, and (3) inserting four full-scale mockups of thermionic type fuel elements near the core and BeO reflector boundary. These mockups were surrounded with a buffer zone having the equivalent thermionic core composition. In addition to measuring the critical mass of this thermionic configuration, a detailed power distribution in one of the thermionic element stages in the mixed spectrum region was measured. A power peak to average ratio of two was observed for this fuel stage at the midplane of the core and adjacent to the reflector. Also, the power on the outer surface adjacent to the BeO was slightly more than a factor of two larger than the power on the inside surface of a 5.08 cm (2.0 in.) high annular fuel segment with a 2.52 cm (0.993 in. ) o.d. and a 1.86 cm (0.731 in.) i.d.

  15. Zero Gravity Flights as the Most Effective Embryonic Operation for Planned Commercial Spaceport

    NASA Astrophysics Data System (ADS)

    Abu Samah, Shamsul Kamar; Ridzuan Zakaria, Norul; Nasrun, Nasri; Abu, Jalaluddin; Muszaphar Shukor, Dato'Sheikh

    2013-09-01

    From the experience gained by the management team of Spaceport Malaysia, a popular service that can be provided by a planned commercial spaceport in a country without existing space travel infrastructure are zero gravity flights. Zero gravity flights range from parabolic flights using aerobatic airplane to suborbital flights using rockets, and in the near future using suborbital rocketplanes. Therefore, zero gravity flights can be operated from a certified runway or planned for operation at a future commercial spaceport. With such range of operation, zero gravity flights provide a natural link between a low cost operation of small airplane to exclusive high profile operation of suborbital rocketplane, and this attracts the attention of individuals and organizations that are planning for the establishment of a commercial spaceport. This is the approach chosen by the planners and developers of Spaceport Malaysia. A significant factor in zero gravity flight is the zero gravity time, the period where the payload onboard the airplane or rocketplane will experience zero gravity. Based on the momentum of the airplane or rocketplane, the zero gravity time may vary from few seconds to few minutes and that determines the quality of the zero gravity flight. To achieve zero gravity, the airplane or rocketplane will fly with a steady velocity for a significant time as a gravity control flight, accelerate upwards with an angle producing hypergravity and perform parabolic flight with natural momentum producing zero gravity and followed by dive that will result in another hypergravity flight. 2 zero gravity platforms being considered for operation at and by Spaceport Malaysia are F-5E Tiger II and Airbus A300, since both platforms have been successfully used by a partner of Spaceport Malaysia in performing zero gravity flights. An F-5E fighter jet owned by Royal Malaysian Air Force is being planned to be converted into a zero gravity platform to be operated at and by Spaceport

  16. Practical Application Limits of Fuel Cells and Batteries for Zero Emission Vessels

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

    Minnehan, John J.; Pratt, Joseph William

    Batteries and hydrogen fuel cells provide zero emission power at the point of use. They are studied as an alternative powerplant for maritime vessels by considering 14 case studies of various ship sizes and routes varying from small passenger vessels to the largest cargo ships. The method used was to compare the mass and volume of the required zero emission solution to the available mass and volume on an existing vessel considering its current engine and fuel storage systems. The results show that it is practically feasible to consider these zero emission technologies for most vessels in the world's fleet.more » Hydrogen fuel cells proved to be the most capable while battery systems showed an advantage for high power, short duration missions. The results provide a guide to ship designers to determine the most suitable types of zero emission powerplants to fit a ship based on its size and energy requirements.« less

  17. Low-Frequency Surface Backscattering Strengths Measured in the Critical Sea Test Experiments

    DTIC Science & Technology

    2017-01-19

    Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/7160--17-9702 Low-Frequency Surface Backscattering Strengths Measured in the Critical Sea ...LIMITATION OF ABSTRACT Low-Frequency Surface Backscattering Strengths Measured in the Critical Sea Test Experiments Roger C. Gauss1 and Joseph M...significantly- updated results from 55 broadband SUS SSS measurements in 6 Critical Sea Test (CST) experiments. Since the time of the previously

  18. THE HOT CRITICAL ASSEMBLY $sub 4$CESAR$sub 4$ (in French)

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

    Tanguy, P.

    1963-07-01

    With Cesar, the Cadarache Center for Nuclear Studies will be equipped with a zero-power critical assembly, which will enable it to obtain the data necessary for the development of natural uranium, graphite, gas reactors. Reactivity balance, evolution of the reactivity, and deformation of the flux curves are to be studied. These studies will complement those already being done on Marius, but carried out at room temperature; in Cesar the graphite temperature can reach 500 deg C. (auth)

  19. Acoustic perfect absorption and broadband insulation achieved by double-zero metamaterials

    NASA Astrophysics Data System (ADS)

    Wang, Xiaole; Luo, Xudong; Zhao, Hui; Huang, Zhenyu

    2018-01-01

    We report the mechanism for simultaneous realization of acoustic perfect absorption (PA) and broadband insulation (BI) in the acoustic free field by a layered acoustic metamaterial (LAM). The proposed LAM comprises two critically coupled membrane-type acoustic metamaterials sandwiching a porous material layer. Both theoretical and experimental results verify that the proposed LAM sample can achieve nearly PA (98.4% in experiments) at 312 Hz with a thickness of 15 mm (1/73 of wavelength) and BI in the frequency range of 200-1000 Hz with an areal density of 2.2 kg/m2. In addition, the real parts of both the effective dynamic density and bulk modulus reach zero precisely at the critical frequency of 312 Hz, arising from the monopolar eigenmode of LAM. Our work advances the concept of synthetic design of sound absorption and insulation properties of multi-impedance-coupled acoustic systems and promotes membrane-type acoustic metamaterials to more practical engineering applications.

  20. Critical opalescence in baryonic QCD matter.

    PubMed

    Antoniou, N G; Diakonos, F K; Kapoyannis, A S; Kousouris, K S

    2006-07-21

    We show that critical opalescence, a clear signature of second-order phase transition in conventional matter, manifests itself as critical intermittency in QCD matter produced in experiments with nuclei. This behavior is revealed in transverse momentum spectra as a pattern of power laws in factorial moments, to all orders, associated with baryon production. This phenomenon together with a similar effect in the isoscalar sector of pions (sigma mode) provide us with a set of observables associated with the search for the QCD critical point in experiments with nuclei at high energies.

  1. Pulse-excited, auto-zeroing multiple channel data transmission system

    NASA Astrophysics Data System (ADS)

    Fasching, G. E.

    1985-02-01

    A multiple channel data transmission system is provided in which signals from a plurality of pulse operated transducers and a corresponding plurality of pulse operated signal processor channels are multiplexed for single channel FM transmission to a receiving station. The transducers and corresponding channel amplifiers are powered by pulsing the dc battery power to these devices to conserve energy and battery size for long-term data transmission from remote or inaccessible locations. Auto zeroing of the signal channel amplifiers to compensate for drift associated with temperature changes, battery decay, component aging, etc., in each channel is accomplished by means of a unique auto zero feature which between signal pulses holds a zero correction voltage on an integrating capacitor coupled to the corresponding channel amplifier output. Pseudo-continuous outputs for each channel are achieved by pulsed sample-and-hold circuits which are updated at the pulsed operation rate. The sample-and-hold outputs are multiplexed into an FM/FM transmitter for transmission to an FM receiver station for demultiplexing and storage in separate channel recorders.

  2. Pulse-excited, auto-zeroing multiple channel data transmission system

    DOEpatents

    Fasching, G.E.

    1985-02-22

    A multiple channel data transmission system is provided in which signals from a plurality of pulse operated transducers and a corresponding plurality of pulse operated signal processor channels are multiplexed for single channel FM transmission to a receiving station. The transducers and corresponding channel amplifiers are powered by pulsing the dc battery power to these devices to conserve energy and battery size for long-term data transmission from remote or inaccessible locations. Auto zeroing of the signal channel amplifiers to compensate for drift associated with temperature changes, battery decay, component aging, etc., in each channel is accomplished by means of a unique auto zero feature which between signal pulses holds a zero correction voltage on an integrating capacitor coupled to the corresponding channel amplifier output. Pseudo-continuous outputs for each channel are achieved by pulsed sample-and-hold circuits which are updated at the pulsed operation rate. The sample-and-hold outputs are multiplexed into an FM/FM transmitter for transmission to an FM receiver station for demultiplexing and storage in separate channel recorders.

  3. Pulse-excited, auto-zeroing multiple channel data transmission system

    DOEpatents

    Fasching, George E.

    1987-01-01

    A multiple channel data transmission system is provided in which signals from a plurality of pulse operated transducers and a corresponding plurality of pulse operated signal processor channels are multiplexed for single channel FM transmission to a receiving station. The transducers and corresponding channel amplifiers are powered by pulsing the dc battery power to these devices to conserve energy and battery size for long-term data transmission from remote or inaccessible locations. Auto zeroing of the signal channel amplifiers to compensate for drift associated with temperature changes, battery decay, component aging, etc., in each channel is accomplished by means of a unique auto zero feature which between signal pulses holds a zero correction voltage on an integrating capacitor coupled to the corresponding channel amplifier output. Pseudo-continuous outputs for each channel are achieved by pulsed sample-and-hold circuits which are updated at the pulsed operation rate. The sample-and-hold outputs are multiplexed into an FM/FM transmitter for transmission to an FM receiver station for demultiplexing and storage in separate channel recorders.

  4. Criticality of the mean-field spin-boson model: boson state truncation and its scaling analysis

    NASA Astrophysics Data System (ADS)

    Hou, Y.-H.; Tong, N.-H.

    2010-11-01

    The spin-boson model has nontrivial quantum phase transitions at zero temperature induced by the spin-boson coupling. The bosonic numerical renormalization group (BNRG) study of the critical exponents β and δ of this model is hampered by the effects of boson Hilbert space truncation. Here we analyze the mean-field spin boson model to figure out the scaling behavior of magnetization under the cutoff of boson states N b . We find that the truncation is a strong relevant operator with respect to the Gaussian fixed point in 0 < s < 1/2 and incurs the deviation of the exponents from the classical values. The magnetization at zero bias near the critical point is described by a generalized homogeneous function (GHF) of two variables τ = α - α c and x = 1/ N b . The universal function has a double-power form and the powers are obtained analytically as well as numerically. Similarly, m( α = α c ) is found to be a GHF of γ and x. In the regime s > 1/2, the truncation produces no effect. Implications of these findings to the BNRG study are discussed.

  5. Time delay of critical images of a point source near the gravitational lens fold-caustic

    NASA Astrophysics Data System (ADS)

    Alexandrov, A.; Zhdanov, V.

    2016-06-01

    Within the framework of the analytical theory of the gravitational lensing we derive asymptotic formula for the time delay of critical images of apoint source, which is situated near a fold-caustic. We found corrections of the first and second order in powers of a parameter, which describescloseness of the source to the caustic. Our formula modifies earlier result by Congdon, Keeton &Nordgren (MNRAS, 2008) obtained in zero-orderapproximation. We have proved the hypothesis put forward by these authors that the first-order correction to the relative time delay of two criticalmages is identically zero. The contribution of the corrections is illustrated in model example by comparison with exact expression.

  6. Separation of biogenic materials by electrophoresis under zero gravity (L-3)

    NASA Technical Reports Server (NTRS)

    Kuroda, Masao

    1993-01-01

    Electrophoresis separates electrically charged materials by imposing a voltage between electrodes. Though free-flow electrophoresis is used without carriers such as colloids to separate and purify biogenic materials including biogenic cells and proteins in blood, its resolving power and separation efficiency is very low on Earth due to sedimentation, flotation, and thermal convection caused by the specific gravity differences between separated materials and buffer solutions. The objective of this experiment is to make a comparative study of various electrophoresis conditions on the ground and in zero-gravity in order to ultimately develop a method for separating various important 'vial' components which are difficult to separate on the ground.

  7. Critical ionization velocity experiments in space

    NASA Astrophysics Data System (ADS)

    Lai, Shu T.; Murad, Edmond

    1989-07-01

    Space experiments to test the critical ionization velocity (CIV) theory have, on the whole, yielded negative results, with two notable exceptions. The results of all the experiments are analyzed with a view towards either optimizing or drawing conclusions about the conditions which lead to the propagation of CIV. In particular, four aspects of the conditions are considered: (1) beam injection angle with the ambient magnetic field in the ionosphere; (2) length of a CIV discharge region in a conical beam; (3) collisional ionization of the neutrals; and (4) chemiionization processes. The analysis leads to the conclusion that using the exhaust of the Shuttle engines may be the best way for testing CIV.

  8. The electrical properties of zero-gravity processed immiscibles

    NASA Technical Reports Server (NTRS)

    Lacy, L. L.; Otto, G. H.

    1974-01-01

    When dispersed or mixed immiscibles are solidified on earth, a large amount of separation of the constituents takes place due to differences in densities. However, when the immiscibles are dispersed and solidified in zero-gravity, density separation does not occur, and unique composite solids can be formed with many new and promising electrical properties. By measuring the electrical resistivity and superconducting critical temperature, Tc, of zero-g processed Ga-Bi samples, it has been found that the electrical properties of such materials are entirely different from the basic constituents and the ground control samples. Our results indicate that space processed immiscible materials may form an entirely new class of electronic materials.

  9. Enhanced removal of ethanolamine from secondary system of nuclear power plant wastewater by novel hybrid nano zero-valent iron and pressurized ozone initiated oxidation process.

    PubMed

    Lee, Son Dong; Mallampati, Srinivasa Reddy; Lee, Byoung Ho

    2017-07-01

    Monoethanolamine (shortly ethanolamine (ETA)), usually used as a corrosion inhibitor, is a contaminant of wastewater from the secondary cooling system of nuclear power plants (NPPs) and is not readily biodegradable. We conducted various experiments, including treatments with nano zero-valent iron (nZVI), nano-iron/calcium, and calcium oxide (nFe/Ca/CaO) with ozone (O 3 ) or hydrogen peroxide (H 2 O 2 ) to reduce the concentration of ETA and to decrease the chemical demand of oxygen (COD) of these wastewaters. During this study, wastewater with ETA concentration of 7465 mg L -1 and COD of 6920 mg L -1 was used. As a result, the ETA concentration was reduced to 5 mg L -1 (a decrease of almost 100%) and COD was reduced to 2260 mg L -1 , a reduction of 67%, using doses of 26.8 mM of nZVI and 1.5 mM of H 2 O 2 at pH 3 for 3 h. Further treatment for 48 h allowed a decrease of COD by almost 97%. Some mechanistic considerations are proposed in order to explain the degradation pathway. The developed hybrid nano zero-valent iron-initiated oxidation process with H 2 O 2 is promising in the treatment of ETA-contaminated wastewaters.

  10. Getting to Zero Yield: The Evolution of the U.S. Position on the CTBT

    NASA Astrophysics Data System (ADS)

    Zimmerman, Peter D.

    1998-03-01

    In 1994 the United States favored a Comprehensive Test Ban Treaty (CTBT) which permitted tiny "hydronuclear" experiments with a nuclear energy release of four pounds or less. Other nuclear powers supported yield limits as high as large fractions of a kiloton, while most non-nuclear nations participating in the discussions at the United Nations Conference on Disarmament wanted to prohibit all nuclear explosions -- some even favoring an end to computer simulations. On the other hand, China wished an exception to permit high yield "peaceful" nuclear explosions. For the United States to adopt a new position favoring a "true zero" several pieces had to fall into place: 1) The President had to be assured that the U.S. could preserve the safety and reliability of the enduring stockpile without yield testing; 2) the U.S. needed to be sure that the marginal utility of zero-yield experiments was at least as great for this country as for any other; 3) that tests with any nuclear yield might have more marginal utility for nuclear proliferators than for the United States, thus marginally eroding this country's position; 4) the United States required a treaty which would permit maintenance of the capacity to return to testing should a national emergency requiring a nuclear test arise; and 5) all of the five nuclear weapons states had to realize that only a true-zero CTBT would have the desired political effects. This paper will outline the physics near zero yield and show why President Clinton was persuaded by arguments from many viewpoints to endorse a true test ban in August, 1996 and to sign the CTBT in September, 1997.

  11. NASA's Zero-g aircraft operations

    NASA Technical Reports Server (NTRS)

    Williams, R. K.

    1988-01-01

    NASA's Zero-g aircraft, operated by the Johnson Space Center, provides the unique weightless or zero-g environment of space flight for hardware development and test and astronaut training purposes. The program, which began in 1959, uses a slightly modified Boeing KC-135A aircraft, flying a parabolic trajectory, to produce weightless periods of 20 to 25 seconds. The program has supported the Mercury, Gemini, Apollo, Skylab, Apollo-Soyuz and Shuttle programs as well as a number of unmanned space operations. Typical experiments for flight in the aircraft have included materials processing experiments, welding, fluid manipulation, cryogenics, propellant tankage, satellite deployment dynamics, planetary sciences research, crew training with weightless indoctrination, space suits, tethers, etc., and medical studies including vestibular research. The facility is available to microgravity research organizations on a cost-reimbursable basis, providing a large, hands-on test area for diagnostic and support equipment for the Principal Investigators and providing an iterative-type design approach to microgravity experiment development. The facility allows concepts to be proven and baseline experimentation to be accomplished relatively inexpensively prior to committing to the large expense of a space flight.

  12. Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In front of the Headquarters Building at KSC, Center Director Roy Bridges (left) looks at the hydrogen-oxygen driven engine powering a Zero Emissions (ZE) transit bus. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by- product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. Available for viewing by employees, the ZE bus is also being used on tour routes at the KSC Visitor Complex Oct. 26-27.

  13. Influence of dispersion stretching of ultrashort UV laser pulse on the critical power for self-focusing

    NASA Astrophysics Data System (ADS)

    Ionin, A. A.; Mokrousova, D. V.; Piterimov, D. A.; Seleznev, L. V.; Sinitsyn, D. V.; Sunchugasheva, E. S.

    2018-04-01

    The critical power for self-focusing in air for ultrashort ultraviolet laser pulses, stretched due to dispersion from 90 to 730 fs, was experimentally measured. It was shown that the pulse duration enhancement due to its propagation in condensed media leads to an almost linear decrease in the critical power for self-focusing. It was also observed that when the pulse peak power exceeds the critical one, the maximum of linear plasma distribution along the ultraviolet laser filament does not shift in the direction opposite to the laser pulse propagation, as observed for infrared laser filaments, but remains at the geometrical focus.

  14. Constraints on texture zero and cofactor zero models for neutrino mass

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

    Whisnant, K.; Liao, Jiajun; Marfatia, D.

    2014-06-24

    Imposing a texture or cofactor zero on the neutrino mass matrix reduces the number of independent parameters from nine to seven. Since five parameters have been measured, only two independent parameters would remain in such models. We find the allowed regions for single texture zero and single cofactor zero models. We also find strong similarities between single texture zero models with one mass hierarchy and single cofactor zero models with the opposite mass hierarchy. We show that this correspondence can be generalized to texture-zero and cofactor-zero models with the same homogeneous costraints on the elements and cofactors.

  15. Vulnerability analysis and critical areas identification of the power systems under terrorist attacks

    NASA Astrophysics Data System (ADS)

    Wang, Shuliang; Zhang, Jianhua; Zhao, Mingwei; Min, Xu

    2017-05-01

    This paper takes central China power grid (CCPG) as an example, and analyzes the vulnerability of the power systems under terrorist attacks. To simulate the intelligence of terrorist attacks, a method of critical attack area identification according to community structures is introduced. Meanwhile, three types of vulnerability models and the corresponding vulnerability metrics are given for comparative analysis. On this basis, influence of terrorist attacks on different critical areas is studied. Identifying the vulnerability of different critical areas will be conducted. At the same time, vulnerabilities of critical areas under different tolerance parameters and different vulnerability models are acquired and compared. Results show that only a few number of vertex disruptions may cause some critical areas collapse completely, they can generate great performance losses the whole systems. Further more, the variation of vulnerability values under different scenarios is very large. Critical areas which can cause greater damage under terrorist attacks should be given priority of protection to reduce vulnerability. The proposed method can be applied to analyze the vulnerability of other infrastructure systems, they can help decision makers search mitigation action and optimum protection strategy.

  16. Experiences of Agricultural Education Preservice Teachers Engaging in Critical Friendships

    ERIC Educational Resources Information Center

    Sellick, Sable; Shoulders, Catherine W.; Johnson, Donald M.; Goodwin, H. L.

    2017-01-01

    As teachers search for ways to improve their craft through reflection, critical friendships have proven to be effective at improving preservice and inservice teachers' reflective behaviors. This qualitative study sought to understand the experiences of agricultural education preservice teachers participating in critical friendships with other…

  17. Manipulation of BDNF signaling modifies the experience-dependent plasticity induced by pure tone exposure during the critical period in the primary auditory cortex.

    PubMed

    Anomal, Renata; de Villers-Sidani, Etienne; Merzenich, Michael M; Panizzutti, Rogerio

    2013-01-01

    Sensory experience powerfully shapes cortical sensory representations during an early developmental "critical period" of plasticity. In the rat primary auditory cortex (A1), the experience-dependent plasticity is exemplified by significant, long-lasting distortions in frequency representation after mere exposure to repetitive frequencies during the second week of life. In the visual system, the normal unfolding of critical period plasticity is strongly dependent on the elaboration of brain-derived neurotrophic factor (BDNF), which promotes the establishment of inhibition. Here, we tested the hypothesis that BDNF signaling plays a role in the experience-dependent plasticity induced by pure tone exposure during the critical period in the primary auditory cortex. Elvax resin implants filled with either a blocking antibody against BDNF or the BDNF protein were placed on the A1 of rat pups throughout the critical period window. These pups were then exposed to 7 kHz pure tone for 7 consecutive days and their frequency representations were mapped. BDNF blockade completely prevented the shaping of cortical tuning by experience and resulted in poor overall frequency tuning in A1. By contrast, BDNF infusion on the developing A1 amplified the effect of 7 kHz tone exposure compared to control. These results indicate that BDNF signaling participates in the experience-dependent plasticity induced by pure tone exposure during the critical period in A1.

  18. The Zero Boil-Off Tank Experiment Ground Testing and Verification of Fluid and Thermal Performance

    NASA Technical Reports Server (NTRS)

    Chato, David J.; Kassemi, Mohammad; Kahwaji, Michel; Kieckhafer, Alexander

    2016-01-01

    The Zero Boil-Off Technology (ZBOT) Experiment involves performing a small scale International Space Station (ISS) experiment to study tank pressurization and pressure control in microgravity. The ZBOT experiment consists of a vacuum jacketed test tank filled with an inert fluorocarbon simulant liquid. Heaters and thermo-electric coolers are used in conjunction with an axial jet mixer flow loop to study a range of thermal conditions within the tank. The objective is to provide a high quality database of low gravity fluid motions and thermal transients which will be used to validate Computational Fluid Dynamic (CFD) modeling. This CFD can then be used in turn to predict behavior in larger systems with cryogens. This paper will discuss the work that has been done to demonstrate that the ZBOT experiment is capable of performing the functions required to produce a meaningful and accurate results, prior to its launch to the International Space Station. Main systems discussed are expected to include the thermal control system, the optical imaging system, and the tank filling system.This work is sponsored by NASAs Human Exploration Mission Directorates Physical Sciences Research program.

  19. [Chernobyl nuclear power plant accident and Tokaimura criticality accident].

    PubMed

    Takada, Jun

    2012-03-01

    It is clear from inspection of historical incidents that the scale of disasters in a nuclear power plant accident is quite low level overwhelmingly compared with a nuclear explosion in nuclear war. Two cities of Hiroshima and Nagasaki were destroyed by nuclear blast with about 20 kt TNT equivalent and then approximately 100,000 people have died respectively. On the other hand, the number of acute death is 30 in the Chernobyl nuclear reactor accident. In this chapter, we review health hazards and doses in two historical nuclear incidents of Chernobyl and Tokaimura criticality accident and then understand the feature of the radiation accident in peaceful utilization of nuclear power.

  20. Review of battery powered embedded systems design for mission-critical low-power applications

    NASA Astrophysics Data System (ADS)

    Malewski, Matthew; Cowell, David M. J.; Freear, Steven

    2018-06-01

    The applications and uses of embedded systems is increasingly pervasive. Mission and safety critical systems relying on embedded systems pose specific challenges. Embedded systems is a multi-disciplinary domain, involving both hardware and software. Systems need to be designed in a holistic manner so that they are able to provide the desired reliability and minimise unnecessary complexity. The large problem landscape means that there is no one solution that fits all applications of embedded systems. With the primary focus of these mission and safety critical systems being functionality and reliability, there can be conflicts with business needs, and this can introduce pressures to reduce cost at the expense of reliability and functionality. This paper examines the challenges faced by battery powered systems, and then explores at more general problems, and several real-world embedded systems.

  1. Deconstructing Global Markets through Critical Performative Experiences in Puerto Rico

    ERIC Educational Resources Information Center

    Medina, Carmen Liliana; Weltsek, Gustave J.

    2013-01-01

    Critical Performative Pedagogies, the idea that "The nature of drama as a once removed creative experience turns non-critical implicit classroom identity formation into explicit identity performance as it asks participants to actively reflect upon how identity is created and engaged within fictional social interactions." (Weltsek and…

  2. Development and Design of Zero-g Liquid Quantity Gauge for Solar Thermal Vehicle

    NASA Technical Reports Server (NTRS)

    Dodge, Franklin T.; Green, Steven T.; Petullo, Steven P.; VanDresar, Neil T.

    2002-01-01

    The development and design of a cryogenic liquid quantity gauge for zero-gravity (zero-g) applications are described. The gauge, named the compression mass gauge (CMG), operates on the principle of slightly changing the volume of the tank by an oscillating bellows. The resulting pressure change is measured and used to predict the volume of vapor in the tank, from which the volume of liquid is computed. For each gauging instance, pressures are measured for several different bellows frequencies to enable minor real-gas effects to be quantified and thereby to obtain a gauging accuracy of 11 percent of tank volume. The CMG has been selected by NASA's Future-X program for a flight demonstration on the United States Air Force-Boeing Solar Orbit Transfer Vehicle Space Experiment (SOTVSE). This report reviews the design trade studies needed for the CMG to satisfy the SOTVSE limitations on its power, volume, and mass and also describes the mechanical design of the CMG.

  3. Power-Stepped HF Cross Modulation Experiments at HAARP

    NASA Astrophysics Data System (ADS)

    Greene, S.; Moore, R. C.; Langston, J. S.

    2013-12-01

    High frequency (HF) cross modulation experiments are a well established means for probing the HF-modified characteristics of the D-region ionosphere. In this paper, we apply experimental observations of HF cross-modulation to the related problem of ELF/VLF wave generation. HF cross-modulation measurements are used to evaluate the efficiency of ionospheric conductivity modulation during power-stepped modulated HF heating experiments. The results are compared to previously published dependencies of ELF/VLF wave amplitude on HF peak power. The experiments were performed during the March 2013 campaign at the High Frequency Active Auroral Research Program (HAARP) Observatory. HAARP was operated in a dual-beam transmission format: the first beam heated the ionosphere using sinusoidal amplitude modulation while the second beam broadcast a series of low-power probe pulses. The peak power of the modulating beam was incremented in 1-dB steps. We compare the minimum and maximum cross-modulation effect and the amplitude of the resulting cross-modulation waveform to the expected power-law dependence of ELF/VLF wave amplitude on HF power.

  4. Zero/zero rotorcraft certification issues. Volume 2: Plenary session presentations

    NASA Technical Reports Server (NTRS)

    Adams, Richard J.

    1988-01-01

    This report analyzes the Zero/Zero Rotorcraft Certification Issues from the perspectives of manufacturers, operators, researchers and the FAA. The basic premise behind this analysis is that zero/zero, or at least extremely low visibility, rotorcraft operations are feasible today from both a technological and an operational standpoint. The questions and issues that need to be resolved are: What certification requirements do we need to ensure safety. Can we develop procedures which capitalize on the performance and maneuvering capabilities unique to rotorcraft. Will extremely low visibility operations be economically feasible. This is Volume 2 of three. It presents the operator perspectives (system needs), applicable technology and zero/zero concepts developed in the first 12 months of research of this project.

  5. The response of single human cells to zero gravity

    NASA Technical Reports Server (NTRS)

    Montgomery, P. O., Jr.; Cook, J. E.; Reynolds, R. C.; Paul, J. S.; Hayflick, L.; Stock, D.; Schulz, W. W.; Kimzey, S. L.; Thirolf, R. G.; Rogers, T.

    1974-01-01

    The SO15 experiment was designed to extend observations of the effects of zero-gravity to living human cells during and subsequent to a 59-day flight on Skylab 3. A strain of diploid human embryonic lung cells, WI-38, was chosen for this purpose. The studies were concerned with observations designed to detect the effects of zero-gravity on cell growth rates and on cell structure as observed by light microscopy, transmission and scanning electron microscopy and histochemistry. Studies of the effects of zero-gravity on the cell function and the cell cycle were performed by time lapse motion picture photography and microspectrophotometry. Subsequent study of the returned living cells included karotyping, G- and C-banding, and analyses of the culture media used. Some of the living cells returned were banked by deep freeze techniques for possible future experiments.

  6. 3D Printing In Zero-G ISS Technology Demonstration

    NASA Technical Reports Server (NTRS)

    Werkheiser, Niki; Cooper, Kenneth; Edmunson, Jennifer; Dunn, Jason; Snyder, Michael

    2014-01-01

    unique design options that are not possible through traditional manufacturing methods while offering cost-effective, high-precision, low-unit on-demand manufacturing. Thus, Additive Manufacturing capabilities are the foundation of an advanced manufacturing in space roadmap. The 3D Printing In Zero-G experiment will demonstrate the capability of utilizing Additive Manufacturing technology in space. This will serve as the enabling first step to realizing an additive manufacturing, print-on-demand "machine shop" for long-duration missions and sustaining human exploration of other planets, where there is extremely limited ability and availability of Earth-based logistics support. Simply put, Additive Manufacturing in space is a critical enabling technology for NASA. It will provide the capability to produce hardware on-demand, directly lowering cost and decreasing risk by having the exact part or tool needed in the time it takes to print. This capability will also provide the much-needed solution to the cost, volume, and up-mass constraints that prohibit launching everything needed for long-duration or long-distance missions from Earth, including spare parts and replacement systems. A successful mission for the 3D Printing In Zero-G payload is the first step to demonstrate the capability of printing on orbit. The data gathered and lessons learned from this demonstration will be applied to the next generation of additive manufacturing technology on orbit. It is expected that Additive Manufacturing technology will quickly become a critical part of any mission's infrastructure.

  7. Preliminary drop-tower experiments on liquid-interface geometry in partially filled containers at zero gravity

    NASA Technical Reports Server (NTRS)

    Smedley, G.

    1990-01-01

    Plexiglass containers with rounded trapezoidal cross sections were designed and built to test the validity of Concus and Finn's existence theorem (1974, 1983) for a bounded free liquid surface at zero gravity. Experiments were carried out at the NASA Lewis two-second drop tower. Dyed ethanol-water solutions and three immiscible liquid pairs, with one liquid dyed, were tested. High-speed movies were used to record the liquid motion. Liquid rose to the top of the smaller end of the containers when the contact angle was small enough, in agreement with the theory. Liquid interface motion demonstrated a strong dependence on physical properties, including surface roughness and contamination.

  8. Direct Measurement of Nuclear Dependence of Charged Current Quasielasticlike Neutrino Interactions Using MINERvA

    NASA Astrophysics Data System (ADS)

    Betancourt, M.; Ghosh, A.; Walton, T.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Bodek, A.; Bravar, A.; Cai, T.; Martinez Caicedo, D. A.; Carneiro, M. F.; Dytman, S. A.; Díaz, G. A.; Felix, J.; Fields, L.; Fine, R.; Galindo, R.; Gallagher, H.; Ghosh, A.; Golan, T.; Gran, R.; Harris, D. A.; Higuera, A.; Hurtado, K.; Kiveni, M.; Kleykamp, J.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman, Patrick, C. E.; Perdue, G. N.; Ramírez, M. A.; Ren, L.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Sobczyk, J. T.; Solano Salinas, C. J.; Sánchez Falero, S.; Valencia, E.; Wolcott, J.; Wospakrik, M.; Yaeggy, B.; Minerva Collaboration

    2017-08-01

    Charged-current νμ interactions on carbon, iron, and lead with a final state hadronic system of one or more protons with zero mesons are used to investigate the influence of the nuclear environment on quasielasticlike interactions. The transferred four-momentum squared to the target nucleus, Q2, is reconstructed based on the kinematics of the leading proton, and differential cross sections versus Q2 and the cross-section ratios of iron, lead, and carbon to scintillator are measured for the first time in a single experiment. The measurements show a dependence on the atomic number. While the quasielasticlike scattering on carbon is compatible with predictions, the trends exhibited by scattering on iron and lead favor a prediction with intranuclear rescattering of hadrons accounted for by a conventional particle cascade treatment. These measurements help discriminate between different models of both initial state nucleons and final state interactions used in the neutrino oscillation experiments.

  9. Direct Measurement of Nuclear Dependence of Charged Current Quasielasticlike Neutrino Interactions Using MINERvA

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

    Betancourt, M.; Ghosh, A.; Walton, T.

    Charged-current νμ interactions on carbon, iron, and lead with a final state hadronic system of one or more protons with zero mesons are used to investigate the influence of the nuclear environment on quasielasticlike interactions. The transferred four-momentum squared to the target nucleus, Q2, is reconstructed based on the kinematics of the leading proton, and differential cross sections versus Q2 and the cross-section ratios of iron, lead, and carbon to scintillator are measured for the first time in a single experiment. The measurements show a dependence on the atomic number. While the quasielasticlike scattering on carbon is compatible with predictions,more » the trends exhibited by scattering on iron and lead favor a prediction with intranuclear rescattering of hadrons accounted for by a conventional particle cascade treatment. These measurements help discriminate between different models of both initial state nucleons and final state interactions used in the neutrino oscillation experiments.« less

  10. Propulsion Investigation for Zero and Near-Zero Emissions Aircraft

    NASA Technical Reports Server (NTRS)

    Snyder, Christopher A.; Berton, Jeffrey J.; Brown, Gerald v.; Dolce, James L.; Dravid, Marayan V.; Eichenberg, Dennis J.; Freeh, Joshua E.; Gallo, Christopher A.; Jones, Scott M.; Kundu, Krishna P.; hide

    2009-01-01

    As world emissions are further scrutinized to identify areas for improvement, aviation s contribution to the problem can no longer be ignored. Previous studies for zero or near-zero emissions aircraft suggest aircraft and propulsion system sizes that would perform propulsion system and subsystems layout and propellant tankage analyses to verify the weight-scaling relationships. These efforts could be used to identify and guide subsequent work on systems and subsystems to achieve viable aircraft system emissions goals. Previous work quickly focused these efforts on propulsion systems for 70- and 100-passenger aircraft. Propulsion systems modeled included hydrogen-fueled gas turbines and fuel cells; some preliminary estimates combined these two systems. Hydrogen gas-turbine engines, with advanced combustor technology, could realize significant reductions in nitrogen emissions. Hydrogen fuel cell propulsion systems were further laid out, and more detailed analysis identified systems needed and weight goals for a viable overall system weight. Results show significant, necessary reductions in overall weight, predominantly on the fuel cell stack, and power management and distribution subsystems to achieve reasonable overall aircraft sizes and weights. Preliminary conceptual analyses for a combination of gas-turbine and fuel cell systems were also performed, and further studies were recommended. Using gas-turbine engines combined with fuel cell systems can reduce the fuel cell propulsion system weight, but at higher fuel usage than using the fuel cell only.

  11. "Patient Zero": the absence of a patient's view of the early North American AIDS epidemic.

    PubMed

    McKay, Richard A

    2014-01-01

    This article contextualizes the production and reception of And the Band Played On, Randy Shilts's popular history of the initial recognition of the American AIDS epidemic. Published over twenty-five years ago, the book and its most notorious character, "Patient Zero," are in particular need of a critical historical treatment. The article presents a more balanced consideration-a "patient's view"-of Gaétan Dugas's experience of the early years of AIDS. I oppose the assertion that Dugas, the so-called Patient Zero, ignored incontrovertible information about the condition and was intent on spreading his infection. Instead I argue that scientific ideas in 1982 and 1983 about AIDS and the transmissibility of a causative agent were later portrayed to be more self-evident than they were at the time. The article also traces how Shilts's highly selective-and highly readable-characterization of Dugas rapidly became embedded in discussions about the need to criminalize the reckless transmission of HIV.

  12. Prevalence, Predictors, and Prevention of Motion Sickness in Zero-G Parabolic Flights.

    PubMed

    Golding, John F; Paillard, Aurore C; Normand, Hervé; Besnard, Stéphane; Denise, Pierre

    2017-01-01

    Zero-G parabolic flight reproduces the weightlessness of space for short periods. However, motion sickness may affect some fliers. The aim was to assess the extent of this problem and to find possible predictors and modifying factors. Airbus zero-G flights consist of 31 parabolas performed in blocks. Each parabola consisted of 20 s of 0 g sandwiched by 20 s of hypergravity of 1.5-1.8 g. The survey covered N = 246 person-flights (193 men, 53 women), ages (M ± SD) 36.0 ± 11.3 yr. An anonymous questionnaire included motion sickness rating (1 = OK to 6 = vomiting), Motion Sickness Susceptibility Questionnaire (MSSQ), antimotion sickness medication, prior zero-G experience, anxiety level, and other characteristics. Participants had lower MSSQ percentile scores (27.4 ± 28.0) than the population norm of 50. Motion sickness was experienced by 33% and 12% vomited. Less motion sickness was predicted by older age, greater prior zero-G flight experience, medication with scopolamine, lower MSSQ scores, but not gender or anxiety. Sickness ratings in fliers pretreated with scopolamine (1.81 ± 1.58) were lower than for nonmedicated fliers (2.93 ± 2.16), and incidence of vomiting in fliers using scopolamine treatment was reduced by half to a third. Possible confounding factors including age, sex, flight experience, and MSSQ could not account for this. Motion sickness affected one-third of zero-G fliers despite being intrinsically less motion sickness susceptible compared to the general population. Susceptible individuals probably try to avoid such a provocative environment. Risk factors for motion sickness included younger age and higher MSSQ scores. Protective factors included prior zero-G flight experience (habituation) and antimotion sickness medication.Golding JF, Paillard AC, Normand H, Besnard S, Denise P. Prevalence, predictors, and prevention of motion sickness in zero-G parabolic flights. Aerosp Med Hum Perform. 2017; 88(1):3-9.

  13. Solidification under zero gravity: A Long Duration Exposure Facility (LDEF) experiment for an early space shuttle mission. [project planning

    NASA Technical Reports Server (NTRS)

    Bailey, J. A.

    1976-01-01

    Project planning for two series of simple experiments on the effect of zero gravity on the melting and freezing of metals and nonmetals is described. The experiments will be performed in the Long Duration Exposure Facility, and their purpose will be to study: (1) the general morphology of metals and nonmetals during solidification, (2) the location of ullage space (liquid-vapor interfaces), and (3) the magnitude of surface tension driven convection during solidification of metals and nonmetals. The preliminary design of the experiments is presented. Details of the investigative approach, experimental procedure, experimental hardware, data reduction and analysis, and anticipated results are given. In addition a work plan and cost analysis are provided.

  14. Laboratory outreach: student assessment of flow cytometer fluidics in zero gravity.

    PubMed

    Crucian, B; Norman, J; Brentz, J; Pietrzyk, R; Sams, C

    2000-10-01

    Due to the the clinical utility of the flow cytometer, the National Aeronautics and Space Administration (NASA) is interested in the design of a space flight-compatible cytometer for use on long-duration space missions. Because fluid behavior is altered dramatically during space flight, it was deemed necessary to validate the principles of hydrodynamic focusing and laminar flow (cytometer fluidics) in a true microgravity environment. An experiment to validate these properties was conducted by 12 students from Sweetwater High School (Sweetwater, TX) participating in the NASA Reduced Gravity Student Flight Opportunity, Class of 2000. This program allows high school students to gain scientific experience by conducting an experiment on the NASA KC-135 zero gravity laboratory aircraft. The KC-135 creates actual zero-gravity conditions in 30-second intervals by flying a highly inclined parabolic flight path. The experiment was designed by their mentor in the program, the Johnson Space Center's flow cytometrist Brian Crucian, PhD, MT(ASCP). The students performed the experiment, with the mentor, onboard the NASA zero-gravity research aircraft in April 2000.

  15. Adaptive Control for Buck Power Converter Using Fixed Point Inducting Control and Zero Average Dynamics Strategies

    NASA Astrophysics Data System (ADS)

    Hoyos Velasco, Fredy Edimer; García, Nicolás Toro; Garcés Gómez, Yeison Alberto

    In this paper, the output voltage of a buck power converter is controlled by means of a quasi-sliding scheme. The Fixed Point Inducting Control (FPIC) technique is used for the control design, based on the Zero Average Dynamics (ZAD) strategy, including load estimation by means of the Least Mean Squares (LMS) method. The control scheme is tested in a Rapid Control Prototyping (RCP) system based on Digital Signal Processing (DSP) for dSPACE platform. The closed loop system shows adequate performance. The experimental and simulation results match. The main contribution of this paper is to introduce the load estimator by means of LMS, to make ZAD and FPIC control feasible in load variation conditions. In addition, comparison results for controlled buck converter with SMC, PID and ZAD-FPIC control techniques are shown.

  16. Effect of zero magnetic field on cardiovascular system and microcirculation

    NASA Astrophysics Data System (ADS)

    Gurfinkel, Yu. I.; At'kov, O. Yu.; Vasin, A. L.; Breus, T. K.; Sasonko, M. L.; Pishchalnikov, R. Yu.

    2016-02-01

    The effects of zero magnetic field conditions on cardiovascular system of healthy adults have been studied. In order to generate zero magnetic field, the facility for magnetic fields modeling ;ARFA; has been used. Parameters of the capillary blood flow, blood pressure, and the electrocardiogram (ECG) monitoring were measured during the study. All subjects were tested twice: in zero magnetic field and, for comparison, in sham condition. The obtained results during 60 minutes of zero magnetic field exposure demonstrate a clear effect on cardiovascular system and microcirculation. The results of our experiments can be used in studies of long-term stay in hypo-magnetic conditions during interplanetary missions.

  17. Power-sharing Partnerships: Teachers' Experiences of Participatory Methodology.

    PubMed

    Ferreira, Ronél; Ebersöhn, Liesel; Mbongwe, Bathsheba B

    2015-01-01

    This article reports on the experiences of teachers as coresearchers in a long-term partnership with university researchers, who participated in an asset-based intervention project known as Supportive Teachers, Assets and Resilience (STAR). In an attempt to inform participatory research methodology, the study investigated how coresearchers (teachers) experienced power relations. We utilized Gaventa's power cube as a theoretical framework and participatory research as our methodologic paradigm. Ten teachers of a primary school in the Eastern Cape and five teachers of a secondary school in a remote area in the Mpumalanga Province in South Africa participated (n=15). We employed multiple data generation techniques, namely Participatory Reflection and Action (PRA) activities, observation, focus group discussions, and semistructured interviews, using thematic analysis and categorical aggregation for data analysis. We identified three themes, related to the (1) nature of power in participatory partnerships, (2) coreasearchers' meaning making of power and partnerships, and their (3) role in taking agency. Based on these findings, we developed a framework of power sharing partnerships to extend Gaventa's power cube theory. This framework, and its five interrelated elements (leadership as power, identifying vision and mission, synergy, interdependent role of partners, and determination), provide insight into the way coresearchers shared their experiences of participatory research methodology. We theorise power-sharing partnerships as a complimentary platform hosting partners' shared strengths, skills, and experience, creating synergy in collaborative projects.

  18. A zero-power warming chamber for investigating plant responses to rising temperature

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

    Lewin, Keith F.; McMahon, Andrew M.; Ely, Kim S.

    Advances in understanding and model representation of plant and ecosystem responses to rising temperature have typically required temperature manipulation of research plots, particularly when considering warming scenarios that exceed current climate envelopes. In remote or logistically challenging locations, passive warming using solar radiation is often the only viable approach for temperature manipulation. But, current passive warming approaches are only able to elevate the mean daily air temperature by ~1.5 °C. Motivated by our need to understand temperature acclimation in the Arctic, where warming has been markedly greater than the global average and where future warming is projected to be ~2–3more » °C by the middle of the century; we have developed an alternative approach to passive warming. Our zero-power warming (ZPW) chamber requires no electrical power for fully autonomous operation. It uses a novel system of internal and external heat exchangers that allow differential actuation of pistons in coupled cylinders to control chamber venting. This enables the ZPW chamber venting to respond to the difference between the external and internal air temperatures, thereby increasing the potential for warming and eliminating the risk of overheating. During the thaw season on the coastal tundra of northern Alaska our ZPW chamber was able to elevate the mean daily air temperature 2.6 °C above ambient, double the warming achieved by an adjacent passively warmed control chamber that lacked our hydraulic system. We describe the construction, evaluation and performance of our ZPW chamber and discuss the impact of potential artefacts associated with the design and its operation on the Arctic tundra. Our approach is highly flexible and tunable, enabling customization for use in many different environments where significantly greater temperature manipulation than that possible with existing passive warming approaches is desired.« less

  19. A zero-power warming chamber for investigating plant responses to rising temperature

    NASA Astrophysics Data System (ADS)

    Lewin, Keith F.; McMahon, Andrew M.; Ely, Kim S.; Serbin, Shawn P.; Rogers, Alistair

    2017-09-01

    Advances in understanding and model representation of plant and ecosystem responses to rising temperature have typically required temperature manipulation of research plots, particularly when considering warming scenarios that exceed current climate envelopes. In remote or logistically challenging locations, passive warming using solar radiation is often the only viable approach for temperature manipulation. However, current passive warming approaches are only able to elevate the mean daily air temperature by ˜ 1.5 °C. Motivated by our need to understand temperature acclimation in the Arctic, where warming has been markedly greater than the global average and where future warming is projected to be ˜ 2-3 °C by the middle of the century; we have developed an alternative approach to passive warming. Our zero-power warming (ZPW) chamber requires no electrical power for fully autonomous operation. It uses a novel system of internal and external heat exchangers that allow differential actuation of pistons in coupled cylinders to control chamber venting. This enables the ZPW chamber venting to respond to the difference between the external and internal air temperatures, thereby increasing the potential for warming and eliminating the risk of overheating. During the thaw season on the coastal tundra of northern Alaska our ZPW chamber was able to elevate the mean daily air temperature 2.6 °C above ambient, double the warming achieved by an adjacent passively warmed control chamber that lacked our hydraulic system. We describe the construction, evaluation and performance of our ZPW chamber and discuss the impact of potential artefacts associated with the design and its operation on the Arctic tundra. The approach we describe is highly flexible and tunable, enabling customization for use in many different environments where significantly greater temperature manipulation than that possible with existing passive warming approaches is desired.

  20. A zero-power warming chamber for investigating plant responses to rising temperature

    DOE PAGES

    Lewin, Keith F.; McMahon, Andrew M.; Ely, Kim S.; ...

    2017-09-19

    Advances in understanding and model representation of plant and ecosystem responses to rising temperature have typically required temperature manipulation of research plots, particularly when considering warming scenarios that exceed current climate envelopes. In remote or logistically challenging locations, passive warming using solar radiation is often the only viable approach for temperature manipulation. But, current passive warming approaches are only able to elevate the mean daily air temperature by ~1.5 °C. Motivated by our need to understand temperature acclimation in the Arctic, where warming has been markedly greater than the global average and where future warming is projected to be ~2–3more » °C by the middle of the century; we have developed an alternative approach to passive warming. Our zero-power warming (ZPW) chamber requires no electrical power for fully autonomous operation. It uses a novel system of internal and external heat exchangers that allow differential actuation of pistons in coupled cylinders to control chamber venting. This enables the ZPW chamber venting to respond to the difference between the external and internal air temperatures, thereby increasing the potential for warming and eliminating the risk of overheating. During the thaw season on the coastal tundra of northern Alaska our ZPW chamber was able to elevate the mean daily air temperature 2.6 °C above ambient, double the warming achieved by an adjacent passively warmed control chamber that lacked our hydraulic system. We describe the construction, evaluation and performance of our ZPW chamber and discuss the impact of potential artefacts associated with the design and its operation on the Arctic tundra. Our approach is highly flexible and tunable, enabling customization for use in many different environments where significantly greater temperature manipulation than that possible with existing passive warming approaches is desired.« less

  1. [Gender power, poverty and contraception: multiparous women's experiences].

    PubMed

    Prates, Cibeli de Souza; Abib, Gilda Maria de Carvalho; de Oliveira, Dora Lúcia Leidens Correa

    2008-12-01

    Multiparity among poor women is associated to vulnerability as a generating or strengthening factor. This is a qualitative and exploratory research that aims at analyzing experiences of contraception among poor multiparae women, considering the influence of gender on their autonomy in choosing the number of children, the moment of getting pregnant, and the contraception strategies. It also aims at analyzing the mechanisms of resistance used by these women in the search for such autonomy. The data were gathered through focus groups. The content analysis suggests that the high number of children these women give birth to is explained by a reduced autonomy in their use of contraception, arising from poverty and gender inequalities. These women face these difficulties using resistance strategies that result in male power disruptions. This research has brought new elements for understanding the multiparity phenomenon in the context of poverty, and it also contributes towards a critical analysis of actions focused on promoting family planning.

  2. Critical Literacies: Negotiating Powerful and Pleasurable Curricula--How Do We Foster Critical Literacy through English Language Arts?

    ERIC Educational Resources Information Center

    Comber, Barbara

    All over the world educators work towards social justice in a variety of classroom projects. How might teachers of English language arts be informed by this variety of projects--all of which involve young people and their teachers exploring relationships between language and power? Theoretically, protagonists of critical literacies have many…

  3. Simulated front crawl swimming performance related to critical speed and critical power.

    PubMed

    Toussaint, H M; Wakayoshi, K; Hollander, A P; Ogita, F

    1998-01-01

    Competitive pool swimming events range in distance from 50 to 1500 m. Given the difference in performance times (+/- 23-1000 s), the contribution of the aerobic and anaerobic energy systems changes considerably with race distance. In training practice the regression line between swimming distance and time (Distance = critical velocity x time + anaerobic swimming capacity) is used to determine the individual capacity of the aerobic and anaerobic metabolic pathways. Although there is confidence that critical velocity and anaerobic swimming capacity are fitness measures that separate aerobic and anaerobic components, a firm theoretical basis for the interpretation of these results does not exist. The purpose of this study was to evaluate the critical power concept and anaerobic swimming capacity as measures of the aerobic and anaerobic capacity using a modeling approach. A systems model was developed that relates the mechanics and energetics involved in front crawl swimming performance. From actual swimming flume measurements, the time dependent aerobic and anaerobic energy release was modeled. Data derived from the literature were used to relate the energy cost of front crawl swimming to swimming velocity. A balance should exist between the energy cost to swim a distance in a certain time and the concomitant aerobic and anaerobic energy release. The ensuing model was used to predict performance times over a range of distances (50-1500 m) and to calculate the regression line between swimming distance and time. Using a sensitivity analysis, it was demonstrated that the critical velocity is indicative for the capacity of the aerobic energy system. Estimates of the anaerobic swimming capacity, however, were influenced by variations in both anaerobic and aerobic energy release. Therefore, it was concluded that the anaerobic swimming capacity does not provide a reliable estimate of the anaerobic capacity.

  4. Conductivity of Weakly Disordered Metals Close to a "Ferromagnetic" Quantum Critical Point

    NASA Astrophysics Data System (ADS)

    Kastrinakis, George

    2018-05-01

    We calculate analytically the conductivity of weakly disordered metals close to a "ferromagnetic" quantum critical point in the low-temperature regime. Ferromagnetic in the sense that the effective carrier potential V(q,ω ), due to critical fluctuations, is peaked at zero momentum q=0. Vertex corrections, due to both critical fluctuations and impurity scattering, are explicitly considered. We find that only the vertex corrections due to impurity scattering, combined with the self-energy, generate appreciable effects as a function of the temperature T and the control parameter a, which measures the proximity to the critical point. Our results are consistent with resistivity experiments in several materials displaying typical Fermi liquid behaviour, but with a diverging prefactor of the T^2 term for small a.

  5. Zero-sum bias: perceived competition despite unlimited resources.

    PubMed

    Meegan, Daniel V

    2010-01-01

    Zero-sum bias describes intuitively judging a situation to be zero-sum (i.e., resources gained by one party are matched by corresponding losses to another party) when it is actually non-zero-sum. The experimental participants were students at a university where students' grades are determined by how the quality of their work compares to a predetermined standard of quality rather than to the quality of the work produced by other students. This creates a non-zero-sum situation in which high grades are an unlimited resource. In three experiments, participants were shown the grade distribution after a majority of the students in a course had completed an assigned presentation, and asked to predict the grade of the next presenter. When many high grades had already been given, there was a corresponding increase in low grade predictions. This suggests a zero-sum bias, in which people perceive a competition for a limited resource despite unlimited resource availability. Interestingly, when many low grades had already been given, there was not a corresponding increase in high grade predictions. This suggests that a zero-sum heuristic is only applied in response to the allocation of desirable resources. A plausible explanation for the findings is that a zero-sum heuristic evolved as a cognitive adaptation to enable successful intra-group competition for limited resources. Implications for understanding inter-group interaction are also discussed.

  6. Achieving Zero Stress in Iridium, Chromium, and Nickel Thin Films

    NASA Technical Reports Server (NTRS)

    Broadway, David M.; Weimer, Jeffrey; Gurgew, Danielle; Lis, Tomasz; Ramsey, Brian D.; O'Dell, Stephen L.; Ames, A.; Bruni, R.

    2015-01-01

    We examine a method for achieving zero intrinsic stress in thin films of iridium, chromium, and nickel deposited by magnetron sputter deposition. The examination of the stress in these materials is motivated by efforts to advance the optical performance of light-weight x-ray space telescopes into the regime of sub-arc second resolution that rely on control of the film stress to values within 10-100 MPa. A characteristic feature of the intrinsic stress behavior in chromium and nickel is their sensitivity to the magnitude and sign of the intrinsic stress with argon gas pressure, including the existence of a critical pressure that results in zero film stress. This critical pressure scales linearly with the film's density. While the effect of stress reversal with argon pressure has been previously reported by Hoffman and others for nickel and chromium, we have discovered a similar behavior for iridium. Additionally, we have identified zero stress in iridium shortly after island coalescence. This feature of film growth is used for achieving a total internal stress of -2.89 MPa for a 15.8 nm thick iridium film. The surface roughness of this low-stress film was examined using scanning probe microscopy (SPM) and x-ray reflectivity (XRR) at CuKa and these results presented and discussed.

  7. SPACESUIT DONNING AND DOFFING - ZERO-G TRAINING - DON PETERSON - STS-6

    NASA Image and Video Library

    1982-07-14

    Spacesuit Donning and Doffing in Zero-G Training for Don Peterson of the STS-6 Crew with Astronaut Jerry Ross assisting; and, apparatus for testing the JSC Mechanically-Induced Settling Technology (MIST) Experiment. The training is being held aboard the KC-135 to simulate weightlessness. He is being assisted to don the lower torso of the Extravehicular Mobility Unit (EMU) by an ILC Technician. 1. ASTRONAUT ROSS, JERRY L. - ZERO-G SUITING 2. SHUTTLE - EXPERIMENTS (MIST)

  8. View of Zero-G training for astronauts and payload specialists

    NASA Image and Video Library

    1984-08-27

    S84-40538 (24 Aug 1984) --- Two 41-G payload specialists and a backup for one of them appear to be at home in zero gravity in this scene photographed aboard a KC-135 "Zero gravity" aircraft flying one of its weightlessness opportunity parabolas. Paul D. Scully-Power, a civilian oceanographer with the U.S. Navey, is flanked by Marc Garneau (left) and Robert Thirsk, both representing the National Research Council of Canada. Thirsk is back up payload specialist for Garneau.

  9. Experimental Determination of Dynamical Lee-Yang Zeros

    NASA Astrophysics Data System (ADS)

    Brandner, Kay; Maisi, Ville F.; Pekola, Jukka P.; Garrahan, Juan P.; Flindt, Christian

    2017-05-01

    Statistical physics provides the concepts and methods to explain the phase behavior of interacting many-body systems. Investigations of Lee-Yang zeros—complex singularities of the free energy in systems of finite size—have led to a unified understanding of equilibrium phase transitions. The ideas of Lee and Yang, however, are not restricted to equilibrium phenomena. Recently, Lee-Yang zeros have been used to characterize nonequilibrium processes such as dynamical phase transitions in quantum systems after a quench or dynamic order-disorder transitions in glasses. Here, we experimentally realize a scheme for determining Lee-Yang zeros in such nonequilibrium settings. We extract the dynamical Lee-Yang zeros of a stochastic process involving Andreev tunneling between a normal-state island and two superconducting leads from measurements of the dynamical activity along a trajectory. From the short-time behavior of the Lee-Yang zeros, we predict the large-deviation statistics of the activity which is typically difficult to measure. Our method paves the way for further experiments on the statistical mechanics of many-body systems out of equilibrium.

  10. New type of quantum criticality in the pyrochlore iridates

    DOE PAGES

    Savary, Lucile; Moon, Eun -Gook; Balents, Leon

    2014-11-13

    Magnetic fluctuations and electrons couple in intriguing ways in the vicinity of zero-temperature phase transitions—quantum critical points—in conducting materials. Quantum criticality is implicated in non-Fermi liquid behavior of diverse materials and in the formation of unconventional superconductors. Here, we uncover an entirely new type of quantum critical point describing the onset of antiferromagnetism in a nodal semimetal engendered by the combination of strong spin-orbit coupling and electron correlations, and which is predicted to occur in the iridium oxide pyrochlores. We formulate and solve a field theory for this quantum critical point by renormalization group techniques and show that electrons andmore » antiferromagnetic fluctuations are strongly coupled and that both these excitations are modified in an essential way. This quantum critical point has many novel features, including strong emergent spatial anisotropy, a vital role for Coulomb interactions, and highly unconventional critical exponents. Our theory motivates and informs experiments on pyrochlore iridates and constitutes a singular realistic example of a nontrivial quantum critical point with gapless fermions in three dimensions.« less

  11. Space Experiment Module (SEM)

    NASA Technical Reports Server (NTRS)

    Brodell, Charles L.

    1999-01-01

    The Space Experiment Module (SEM) Program is an education initiative sponsored by the National Aeronautics and Space Administration (NASA) Shuttle Small Payloads Project. The program provides nationwide educational access to space for Kindergarten through University level students. The SEM program focuses on the science of zero-gravity and microgravity. Within the program, NASA provides small containers or "modules" for students to fly experiments on the Space Shuttle. The experiments are created, designed, built, and implemented by students with teacher and/or mentor guidance. Student experiment modules are flown in a "carrier" which resides in the cargo bay of the Space Shuttle. The carrier supplies power to, and the means to control and collect data from each experiment.

  12. Zero to Three: National Center for Infants, Toddlers and Families

    MedlinePlus

    ... Sign In Become a Member Advancing the proven power of early connections Early Development & Well-Being How ... closes Monday! Become a ZERO TO THREE Member! Knowledge and Know-How: Now Available for Individual Purchase ...

  13. Observation weights unlock bulk RNA-seq tools for zero inflation and single-cell applications.

    PubMed

    Van den Berge, Koen; Perraudeau, Fanny; Soneson, Charlotte; Love, Michael I; Risso, Davide; Vert, Jean-Philippe; Robinson, Mark D; Dudoit, Sandrine; Clement, Lieven

    2018-02-26

    Dropout events in single-cell RNA sequencing (scRNA-seq) cause many transcripts to go undetected and induce an excess of zero read counts, leading to power issues in differential expression (DE) analysis. This has triggered the development of bespoke scRNA-seq DE methods to cope with zero inflation. Recent evaluations, however, have shown that dedicated scRNA-seq tools provide no advantage compared to traditional bulk RNA-seq tools. We introduce a weighting strategy, based on a zero-inflated negative binomial model, that identifies excess zero counts and generates gene- and cell-specific weights to unlock bulk RNA-seq DE pipelines for zero-inflated data, boosting performance for scRNA-seq.

  14. The upper critical field of filamentary Nb3Sn conductors

    NASA Astrophysics Data System (ADS)

    Godeke, A.; Jewell, M. C.; Fischer, C. M.; Squitieri, A. A.; Lee, P. J.; Larbalestier, D. C.

    2005-05-01

    We have examined the upper critical field of a large and representative set of present multifilamentary Nb3Sn wires and one bulk sample over a temperature range from 1.4 K up to the zero-field critical temperature. Since all present wires use a solid-state diffusion reaction to form the A15 layers, inhomogeneities with respect to Sn content are inevitable, in contrast to some previously studied homogeneous samples. Our study emphasizes the effects that these inevitable inhomogeneities have on the field-temperature phase boundary. The property inhomogeneities are extracted from field-dependent resistive transitions which we find broaden with increasing inhomogeneity. The upper 90%-99% of the transitions clearly separates alloyed and binary wires but a pure, Cu-free binary bulk sample also exhibits a zero-temperature critical field that is comparable to the ternary wires. The highest μ0Hc2 detected in the ternary wires are remarkably constant: The highest zero-temperature upper critical fields and zero-field critical temperatures fall within 29.5±0.3 and 17.8±0.3K, respectively, independent of the wire layout. The complete field-temperature phase boundary can be described very well with the relatively simple Maki-DeGennes model using a two-parameter fit, independent of composition, strain state, sample layout, or applied critical state criterion.

  15. Critical fluid thermal equilibration experiment (19-IML-1)

    NASA Technical Reports Server (NTRS)

    Wilkinson, R. Allen

    1992-01-01

    Gravity sometimes blocks all experimental techniques of making a desired measurement. Any pure fluid possesses a liquid-vapor critical point. It is defined by a temperature, pressure, and density state in thermodynamics. The critical issue that this experiment attempts to understand is the time it takes for a sample to reach temperature and density equilibrium as the critical point is approached; is it infinity due to mass and thermal diffusion, or do pressure waves speed up energy transport while mass is still under diffusion control. The objectives are to observe: (1) large phase domain homogenization without and with stirring; (2) time evolution of heat and mass after temperature step is applied to a one phase equilibrium sample; (3) phase evolution and configuration upon going two phase from a one phase equilibrium state; (4) effects of stirring on a low g two phase configuration; (5) two phase to one phase healing dynamics starting from a two phase low g configuration; and (6) effects of shuttle acceleration events on spatially and temporally varying compressible critical fluid dynamics.

  16. 14 CFR 61.163 - Aeronautical experience: Powered-lift category rating.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical experience: Powered-lift... Transport Pilots § 61.163 Aeronautical experience: Powered-lift category rating. (a) A person who is applying for an airline transport pilot certificate with a powered-lift category rating must have at least...

  17. 14 CFR 61.163 - Aeronautical experience: Powered-lift category rating.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Aeronautical experience: Powered-lift... Transport Pilots § 61.163 Aeronautical experience: Powered-lift category rating. (a) A person who is applying for an airline transport pilot certificate with a powered-lift category rating must have at least...

  18. Satellite Power System (SPS) resource requirements (critical materials, energy, and land)

    NASA Technical Reports Server (NTRS)

    Kotin, A. D.

    1978-01-01

    The resource impacts of the proposed satellite power system (SPS) were reviewed. Three classes of resource impacts were considered separately: critical materials, energy and land use. The analysis focused on the requirements associated with the annual development of two five-gigawatt satellites and the associated receiving facilities.

  19. Satellite Power System (SPS) resource requirements (critical materials, energy and land)

    NASA Technical Reports Server (NTRS)

    Kotin, A. D.

    1978-01-01

    The resource impacts of the proposed satellite power system are evaluated. Three classes of resource impacts are considered separately: critical materials, energy, and land use. The analysis focuses on the requirements associated with the annual development of two five-gigawatt satellites and the associated receiving facilities.

  20. Superconductivity versus quantum criticality: Effects of thermal fluctuations

    NASA Astrophysics Data System (ADS)

    Wang, Huajia; Wang, Yuxuan; Torroba, Gonzalo

    2018-02-01

    We study the interplay between superconductivity and non-Fermi liquid behavior of a Fermi surface coupled to a massless SU(N ) matrix boson near the quantum critical point. The presence of thermal infrared singularities in both the fermionic self-energy and the gap equation invalidates the Eliashberg approximation, and makes the quantum-critical pairing problem qualitatively different from that at zero temperature. Taking the large N limit, we solve the gap equation beyond the Eliashberg approximation, and obtain the superconducting temperature Tc as a function of N . Our results show an anomalous scaling between the zero-temperature gap and Tc. For N greater than a critical value, we find that Tc vanishes with a Berezinskii-Kosterlitz-Thouless scaling behavior, and the system retains non-Fermi liquid behavior down to zero temperature. This confirms and extends previous renormalization-group analyses done at T =0 , and provides a controlled example of a naked quantum critical point. We discuss the crucial role of thermal fluctuations in relating our results with earlier work where superconductivity always develops due to the special role of the first Matsubara frequency.

  1. From Zero Energy Buildings to Zero Energy Districts

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

    Polly, Ben; Kutscher, Chuck; Macumber, Dan

    Some U.S. cities are planning advanced districts that have goals for zero energy, water, waste, and/or greenhouse gas emissions. From an energy perspective, zero energy districts present unique opportunities to cost-effectively achieve high levels of energy efficiency and renewable energy penetration across a collection of buildings that may be infeasible at the individual building scale. These high levels of performance are accomplished through district energy systems that harness renewable and wasted energy at large scales and flexible building loads that coordinate with variable renewable energy supply. Unfortunately, stakeholders face a lack of documented processes, tools, and best practices to assistmore » them in achieving zero energy districts. The National Renewable Energy Laboratory (NREL) is partnering on two new district projects in Denver: the National Western Center and the Sun Valley Neighborhood. We are working closely with project stakeholders in their zero energy master planning efforts to develop the resources needed to resolve barriers and create replicable processes to support future zero energy district efforts across the United States. Initial results of these efforts include the identification and description of key zero energy district design principles (maximizing building efficiency, solar potential, renewable thermal energy, and load control), economic drivers, and master planning principles. The work has also resulted in NREL making initial enhancements to the U.S. Department of Energy's open source building energy modeling platform (OpenStudio and EnergyPlus) with the long-term goal of supporting the design and optimization of energy districts.« less

  2. Zero-Sum Bias: Perceived Competition Despite Unlimited Resources

    PubMed Central

    Meegan, Daniel V.

    2010-01-01

    Zero-sum bias describes intuitively judging a situation to be zero-sum (i.e., resources gained by one party are matched by corresponding losses to another party) when it is actually non-zero-sum. The experimental participants were students at a university where students’ grades are determined by how the quality of their work compares to a predetermined standard of quality rather than to the quality of the work produced by other students. This creates a non-zero-sum situation in which high grades are an unlimited resource. In three experiments, participants were shown the grade distribution after a majority of the students in a course had completed an assigned presentation, and asked to predict the grade of the next presenter. When many high grades had already been given, there was a corresponding increase in low grade predictions. This suggests a zero-sum bias, in which people perceive a competition for a limited resource despite unlimited resource availability. Interestingly, when many low grades had already been given, there was not a corresponding increase in high grade predictions. This suggests that a zero-sum heuristic is only applied in response to the allocation of desirable resources. A plausible explanation for the findings is that a zero-sum heuristic evolved as a cognitive adaptation to enable successful intra-group competition for limited resources. Implications for understanding inter-group interaction are also discussed. PMID:21833251

  3. Neutron activation of natural materials in a PWR spectrum: feedback on {sup 116m}In relative γ emission intensities and half-life

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

    Gruel, Adrien; Geslot, Benoit; Di Salvo, Jacques

    2015-07-01

    During the MAESTRO program, carried out between 2011 and 2014 in MINERVE zero power reactor, common Gen-II and Gen-III light water reactor materials were irradiated. For some of these materials, the decay of their activation products was also measured by γ spectrometry. Initially devoted to the measurement of the integral capture cross section by activation and reactivity-oscillation method, these results can also provide useful information on decay data of various radionuclides. This approach of this experiment led to a common roadmap shared by the Experimental Physics Section and the Henri Becquerel National Laboratory to improve decay data in nuclear datamore » libraries. Results discussed in this paper concern the relative emission intensities of the main γ rays of {sup 116m}In. Six irradiations of samples with various physical forms of {sup nat}In were carried out. Measurements were analyzed using decay data from several evaluations and it is shown that γ ray activities are not consistent. Analyses were carried out to provide new relative γ emission intensities from these measurements. The {sup 116m}In half-life has also been measured and shows a good agreement with existing values. Finally, an overview of the foreseen results on additional decay data from the MAESTRO program is given. (authors)« less

  4. Experiments on H2-O2MHD power generation

    NASA Technical Reports Server (NTRS)

    Smith, J. M.

    1980-01-01

    Magnetohydrodynamic power generation experiments utilizing a cesium-seeded H2-O2 working fluid were carried out using a diverging area Hall duct having an entrance Mach number of 2. The experiments were conducted in a high-field strength cryomagnet facility at field strengths up to 5 tesla. The effects of power takeoff location, axial duct location within the magnetic field, generator loading, B-field strength, and electrode breakdown voltage were investigated. For the operating conditions of these experiments, it is found that the power output increases with the square of the B-field and can be limited by choking of the channel or interelectrode voltage breakdown which occurs at Hall fields greater than 50 volts/insulator. Peak power densities of greater than 100 MW/cu M were achieved.

  5. The 'Critical Power' Concept: Applications to Sports Performance with a Focus on Intermittent High-Intensity Exercise.

    PubMed

    Jones, Andrew M; Vanhatalo, Anni

    2017-03-01

    The curvilinear relationship between power output and the time for which it can be sustained is a fundamental and well-known feature of high-intensity exercise performance. This relationship 'levels off' at a 'critical power' (CP) that separates power outputs that can be sustained with stable values of, for example, muscle phosphocreatine, blood lactate, and pulmonary oxygen uptake ([Formula: see text]), from power outputs where these variables change continuously with time until their respective minimum and maximum values are reached and exercise intolerance occurs. The amount of work that can be done during exercise above CP (the so-called W') is constant but may be utilized at different rates depending on the proximity of the exercise power output to CP. Traditionally, this two-parameter CP model has been employed to provide insights into physiological responses, fatigue mechanisms, and performance capacity during continuous constant power output exercise in discrete exercise intensity domains. However, many team sports (e.g., basketball, football, hockey, rugby) involve frequent changes in exercise intensity and, even in endurance sports (e.g., cycling, running), intensity may vary considerably with environmental/course conditions and pacing strategy. In recent years, the appeal of the CP concept has been broadened through its application to intermittent high-intensity exercise. With the assumptions that W' is utilized during work intervals above CP and reconstituted during recovery intervals below CP, it can be shown that performance during intermittent exercise is related to four factors: the intensity and duration of the work intervals and the intensity and duration of the recovery intervals. However, while the utilization of W' may be assumed to be linear, studies indicate that the reconstitution of W' may be curvilinear with kinetics that are highly variable between individuals. This has led to the development of a new CP model for intermittent exercise in

  6. Excitation Method of Linear-Motor-Type Rail Brake without Using Power Sources by Dynamic Braking with Zero Electrical Output

    NASA Astrophysics Data System (ADS)

    Sakamoto, Yasuaki; Kashiwagi, Takayuki; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

    The eddy current rail brake is a type of braking system used in railway vehicles. Because of problems such as rail heating and problems associated with ensuring that power is supplied when the feeder malfunctions, this braking system has not been used for practical applications in Japan. Therefore, we proposed the use of linear induction motor (LIM) technology in eddy current rail brake systems. The LIM rail brake driven by dynamic braking can reduce rail heating and generate the energy required for self-excitation. In this paper, we present an excitation system and control method for the LIM rail brake driven by “dynamic braking with zero electrical output”. The proposed system is based on the concept that the LIM rail brake can be energized without using excitation power sources such as a feeder circuit and that high reliability can be realized by providing an independent excitation system. We have studied this system and conducted verification tests using a prototype LIM rail brake on a roller rig. The results show that the system performance is adequate for commercializing the proposed system, in which the LIM rail brake is driven without using any excitation power source.

  7. Comment on ‘The paradoxical zero reflection at zero energy’

    NASA Astrophysics Data System (ADS)

    van Dijk, W.; Nogami, Y.

    2017-05-01

    We point out that the anomalous threshold effect in one dimension occurs when the reflection probability at zero energy R(0) has some other value than unity, rather than R(0)=0 or R(0)\\ll 1 as implied by Ahmed et al in their paper entitled ‘The paradoxical zero reflection at zero energy’ (2017 Eur. J. Phys. 38 025401).

  8. Satellite Power System (SPS) public outreach experiment

    NASA Technical Reports Server (NTRS)

    Mcneal, S. R.

    1980-01-01

    An outreach experiment was conducted to improve the results of the satellite power system (SPS) concept development and evaluation program. The objectives of the outreach were to: (1) determine the areas of major concern relative to the SPS concept and (2) gain experience with an outreach process for use in future public involvement. The response to the outreach effort was positive, suggesting that the effort extended by the SPS project division to encourage an information exchange with the public was well received. The responses were analyzed and from them some questions and answers about the satellite power system are presented.

  9. A Power Experience: A Phenomenological Study of Interprofessional Education.

    PubMed

    Engel, Joyce; Prentice, Dawn; Taplay, Karyn

    The purpose of this supplementary analysis of a hermeneutic phenomenological study of the experience of interprofessional collaboration for nursing and medical students was to explore the experience of power that was threaded throughout the original study. Seventeen students participated in guided, face-to-face conversations in the original study (Prentice, Engel, Taplay, & Stobbe, 2014). Through the processes of deductive analysis and inductive reasoning, 2 themes of power emerged from these research conversations: (a) complicated knowledge is power and (b) the power and silence of intimidation. These themes suggest that power and power differentials are significant factors in student interactions in interprofessional learning and have the potential to adversely affect these interactions. Students' perceptions of power need to be taken into account and addressed when planning and implementing interprofessional education events. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Critical Care Nurses' Experiences With Spiritual Care: The SPIRIT Study.

    PubMed

    Bone, Nigel; Swinton, Marilyn; Hoad, Neala; Toledo, Feli; Cook, Deborah

    2018-05-01

    Little is known about the effect of chaplains on critical care nurses who are caring for critically ill patients and their families. To understand nurses' experiences when they make a referral to the Spiritual Care Department for a patient or the family of a patient who is dying or deceased. Specific aims were to explore spiritual care's effect on nurses and how nurses understand the role of spiritual care in practice. A qualitative descriptive study using in-person, semistructured interviews in a 21-bed medical-surgical intensive care unit in a teaching hospital. Purposeful sampling identified nurses who had at least 5 years of experience and had cared for at least 5 patients who died on their shift and at least 5 patients for whom they initiated a spiritual care referral. Interviews were digitally recorded and anonymized; conventional content analysis was used to analyze transcripts. Three investigators independently coded 5 transcripts and developed the preliminary coding list. As analysis proceeded, investigators organized codes into categories and themes. A total of 25 nurses were interviewed. The central theme that emerged was presence, described through 3 main categories: the value of having chaplains present in the intensive care unit and their role, nurses' experiences working with chaplains, and nurses' experiences providing spiritual care. Nurses considered spiritual care essential to holistic care and valued the support chaplains provide to patients, families, and staff in today's spiritually diverse society. © 2018 American Association of Critical-Care Nurses.

  11. Lee-Yang zero analysis for the study of QCD phase structure

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

    Ejiri, Shinji

    2006-03-01

    We comment on the Lee-Yang zero analysis for the study of the phase structure of QCD at high temperature and baryon number density by Monte-Carlo simulations. We find that the sign problem for nonzero density QCD induces a serious problem in the finite volume scaling analysis of the Lee-Yang zeros for the investigation of the order of the phase transition. If the sign problem occurs at large volume, the Lee-Yang zeros will always approach the real axis of the complex parameter plane in the thermodynamic limit. This implies that a scaling behavior which would suggest a crossover transition will notmore » be obtained. To clarify this problem, we discuss the Lee-Yang zero analysis for SU(3) pure gauge theory as a simple example without the sign problem, and then consider the case of nonzero density QCD. It is suggested that the distribution of the Lee-Yang zeros in the complex parameter space obtained by each simulation could be more important information for the investigation of the critical endpoint in the (T,{mu}{sub q}) plane than the finite volume scaling behavior.« less

  12. Satellite Power Systems /SPS/ - Overview of system studies and critical technology

    NASA Technical Reports Server (NTRS)

    Manson, S. V.

    1980-01-01

    Systems studies and critical technology issues for the development and evaluation of Satellite Power Systems (SPS) for the photovoltaic generation of electrical energy and its transmission to earth are reviewed. Initial concept studies completed in 1976 and system definition studies initiated in the same year have indicated the technical feasibility of SPS and identified challenging issues to be addressed as part of the SPS Concept Development and Evaluation Program. Systems considered in the study include photovoltaic and solar thermal power conversion configurations employing klystron or solid state microwave generators or lasers for power transmission, and power transmission options, system constructability and in-orbit and ground operations. Technology investigations are being performed in the areas of microwave power transmission, structure/controls interactions and the behavior of key materials in the space/SPS environment. Favorable results have been obtained in the areas of microwave phase distribution and phase control, dc-RF conversion, antenna radiating element, and no insurmountable problems have been discovered in any of the investigations to date.

  13. Perceptual disturbances predicted in zero-g through three-dimensional modeling.

    PubMed

    Holly, Jan E

    2003-01-01

    Perceptual disturbances in zero-g and 1-g differ. For example, the vestibular coriolis (or "cross-coupled") effect is weaker in zero-g. In 1-g, blindfolded subjects rotating on-axis experience perceptual disturbances upon head tilt, but the effects diminish in zero-g. Head tilts during centrifugation in zero-g and 1-g are investigated here by means of three-dimensional modeling, using a model that was previously used to explain the zero-g reduction of the on-axis vestibular coriolis effect. The model's foundation comprises the laws of physics, including linear-angular interactions in three dimensions. Addressed is the question: In zero-g, will the vestibular coriolis effect be as weak during centrifugation as during on-axis rotation? Centrifugation in 1-g was simulated first, with the subject supine, head toward center. The most noticeable result concerned direction of head yaw. For clockwise centrifuge rotation, greater perceptual effects arose in simulations during yaw counterclockwise (as viewed from the top of the head) than for yaw clockwise. Centrifugation in zero-g was then simulated with the same "supine" orientation. The result: In zero-g the simulated vestibular coriolis effect was greater during centrifugation than during on-axis rotation. In addition, clockwise-counterclockwise differences did not appear in zero-g, in contrast to the differences that appear in 1-g.

  14. Estimating the Effect of State Zero Tolerance Laws on Exclusionary Discipline, Racial Discipline Gaps, and Student Behavior

    ERIC Educational Resources Information Center

    Curran, F. Chris

    2016-01-01

    Zero tolerance discipline policies have come under criticism as contributors to racial discipline gaps; however, few studies have explicitly examined such policies. This study utilizes data from two nationally representative data sources to examine the effect of state zero tolerance laws on suspension rates and principal perceptions of problem…

  15. From equity to power: Critical Success Factors for Twinning between midwives, a Delphi study.

    PubMed

    Cadée, Franka; Nieuwenhuijze, Marianne J; Lagro-Janssen, Antoine L M; de Vries, Raymond

    2018-02-28

    To gain consensus for Critical Success Factors associated with Twinning in Midwifery. International publications identify midwifery as important for improving maternity care worldwide. Midwifery is a team effort where midwives play a key role. Yet their power to take on this role is often lacking. Twinning has garnered potential to develop power in professionals, however, its success varies because implementation is not always optimal. Critical Success Factors have demonstrated positive results in the managerial context and can be helpful to build effective Twinning relationships. We approached 56 midwife Twinning experts from 19 countries to participate in three Delphi rounds between 2016 - 2017. In round 1, experts gave input through an open ended questionnaire and this was analysed to formulate Critical Success Factors statements that were scored on a 1-7 Likert scale aiming to gain consensus in rounds 2 and 3. These statements were operationalized for practical use such as a check list in planning, monitoring and evaluation in the field. Thirty-three experts from 14 countries took part in all three Delphi rounds, producing 58 initial statements. This resulted in 25 Critical Success Factors covering issues of management, communication, commitment and values, most focus on equity. The Critical Success Factors formulated represent the necessary ingredients for successful Twinning by providing a practical implementation framework and promote further research into the effect of Twinning. Findings show that making equity explicit in Twinning may contribute towards the power of midwives to take on their identified key role. © 2018 The Authors. Journal of Advanced Nursing Published by John Wiley & Sons Ltd.

  16. 76 FR 40945 - Rensselaer Polytechnic Institute Critical Experiments Facility; Notice of Issuance of Renewed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-12

    ... NUCLEAR REGULATORY COMMISSION [Docket No. 50-225; NRC-2008-0277] Rensselaer Polytechnic Institute Critical Experiments Facility; Notice of Issuance of Renewed Facility Operating License No. CX-22 The U.S... of the Rensselaer Polytechnic Institute Critical Experiments Facility (RCF), located in Schenectady...

  17. Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    KSC workers, with Center Director Roy Bridges (at right next to bus), head for the open door of the Zero Emissions (ZE) transit bus and a ride around the center. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. Available to employees for viewing and a ride, the ZE bus is also being used on tour routes at the KSC Visitor Complex Oct. 26-27.

  18. Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    On view in front of the Headquarters Building, the Zero Emissions (ZE) transit bus attracts an interested group of employees, including Center Director Roy Bridges (second from left in foreground). Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. Available for viewing by employees, the ZE bus is also being used on tour routes at the KSC Visitor Complex Oct. 26-27.

  19. Simulated and Virtual Science Laboratory Experiments: Improving Critical Thinking and Higher-Order Learning Skills

    NASA Astrophysics Data System (ADS)

    Simon, Nicole A.

    Virtual laboratory experiments using interactive computer simulations are not being employed as viable alternatives to laboratory science curriculum at extensive enough rates within higher education. Rote traditional lab experiments are currently the norm and are not addressing inquiry, Critical Thinking, and cognition throughout the laboratory experience, linking with educational technologies (Pyatt & Sims, 2007; 2011; Trundle & Bell, 2010). A causal-comparative quantitative study was conducted with 150 learners enrolled at a two-year community college, to determine the effects of simulation laboratory experiments on Higher-Order Learning, Critical Thinking Skills, and Cognitive Load. The treatment population used simulated experiments, while the non-treatment sections performed traditional expository experiments. A comparison was made using the Revised Two-Factor Study Process survey, Motivated Strategies for Learning Questionnaire, and the Scientific Attitude Inventory survey, using a Repeated Measures ANOVA test for treatment or non-treatment. A main effect of simulated laboratory experiments was found for both Higher-Order Learning, [F (1, 148) = 30.32,p = 0.00, eta2 = 0.12] and Critical Thinking Skills, [F (1, 148) = 14.64,p = 0.00, eta 2 = 0.17] such that simulations showed greater increases than traditional experiments. Post-lab treatment group self-reports indicated increased marginal means (+4.86) in Higher-Order Learning and Critical Thinking Skills, compared to the non-treatment group (+4.71). Simulations also improved the scientific skills and mastery of basic scientific subject matter. It is recommended that additional research recognize that learners' Critical Thinking Skills change due to different instructional methodologies that occur throughout a semester.

  20. Nonlinear plasma experiments in geospace with gigawatts of RF power at HAARP

    NASA Astrophysics Data System (ADS)

    Sheerin, J. P.; Cohen, Morris B.

    2015-12-01

    The ionosphere is the ionized uppermost layer of our atmosphere (from 70 - 500 km altitude) where free electron densities yield peak critical frequencies in the HF (3 - 30 MHz) range. The ionosphere thus provides a quiescent plasma target, stable on timescales of minutes, for a whole host of active plasma experiments. High power RF experiments on ionospheric plasma conducted in the U.S. have been reported since 1970. The largest HF transmitter built to date is the HAARP phased-array HF transmitter near Gakona, Alaska which can deliver up to 3.6 Gigawatts (ERP) of CW RF power in the range of 2.8 - 10 MHz to the ionosphere with microsecond pointing, power modulation, and frequency agility. With an ionospheric background thermal energy in the range of only 0.1 eV, this amount of power gives access to the highest regimes of the nonlinearity (RF intensity to thermal pressure) ratio. HAARP's unique features have enabled the conduct of a number of unique nonlinear plasma experiments in the interaction region of overdense ionospheric plasma including generation of artificial aurorae, artificial ionization layers, VLF wave-particle interactions in the magnetosphere, parametric instabilities, stimulated electromagnetic emissions (SEE), strong Langmuir turbulence (SLT) and suprathermal electron acceleration. Diagnostics include the Modular UHF Ionospheric Radar (MUIR) sited at HAARP, the SuperDARN-Kodiak HF radar, spacecraft radio beacons, HF receivers to record stimulated electromagnetic emissions (SEE) and telescopes and cameras for optical emissions. We report on short timescale ponderomotive overshoot effects, artificial field-aligned irregularities (AFAI), the aspect angle dependence of the intensity of the HF-enhanced plasma line, and production of suprathermal electrons. One of the primary missions of HAARP, has been the generation of ELF (300 - 3000 Hz) and VLF (3 - 30 kHz) radio waves which are guided to global distances in the Earth-ionosphere waveguide. We review

  1. Ball Lightning in Zero Gravity in the Laboratory

    NASA Astrophysics Data System (ADS)

    Alexeff, Igor; Parameswaran, Sriram; Grace, Michael

    2004-11-01

    We have created balls of orange plasma in atmospheric - pressure air that survive for over 1/2 second without power input. The technique used was to create a pulsed horizontal electric arc in a zero - gravity environment using 6 neon - sign transformers in parallel, each producing 16,000 V at 60 mA. The zero - gravity environment reduces heat losses by reducing thermal convection, creating a larger ball. Previous work (1) suggests that the ball lifetime scales as the square of the ball radius. The balls were photographed after power turnoff with a high - speed 16 mm movie camera. Movies of the balls being formed and decaying will be shown. We suggest that there are several other forms of ball lightning (2). 1.Igor Alexeff et. al. International Conference On Plasma Science, Jeju, Korea, June 2-5, 2003, Conference Record, p 254. 2. Igor Alexeff and Mark Rader, IEEE Transactions on Plasma Science, Vol. 20, No. 6, Dec. 1992, pp.669-671. Igor Alexeff and Mark Rader, Fusion Technology, Vol. 27, May 1995, p. 271.

  2. Zero-Power-Consumption Solar-Blind Photodetector Based on β-Ga2O3/NSTO Heterojunction.

    PubMed

    Guo, Daoyou; Liu, Han; Li, Peigang; Wu, Zhenping; Wang, Shunli; Cui, Can; Li, Chaorong; Tang, Weihua

    2017-01-18

    A solar-blind photodetector based on β-Ga 2 O 3 /NSTO (NSTO = Nb:SrTiO 3 ) heterojunctions were fabricated for the first time, and its photoelectric properties were investigated. The device presents a typical positive rectification in the dark, while under 254 nm UV light illumination, it shows a negative rectification, which might be caused by the generation of photoinduced electron-hole pairs in the β-Ga 2 O 3 film layer. With zero bias, that is, zero power consumption, the photodetector shows a fast photoresponse time (decay time τ d = 0.07 s) and the ratio I photo /I dark ≈ 20 under 254 nm light illumination with a light intensity of 45 μW/cm 2 . Such behaviors are attributed to the separation of photogenerated electron-hole pairs driven by the built-in electric field in the depletion region of β-Ga 2 O 3 and the NSTO interface, and the subsequent transport toward corresponding electrodes. The photocurrent increases linearly with increasing the light intensity and applied bias, while the response time decreases with the increase of the light intensity. Under -10 V bias and 45 μW/cm 2 of 254 nm light illumination, the photodetector exhibits a responsivity R λ of 43.31 A/W and an external quantum efficiency of 2.1 × 10 4 %. The photo-to-electric conversion mechanism in the β-Ga 2 O 3 /NSTO heterojunction photodetector is explained in detail by energy band diagrams. The results strongly suggest that a photodetector based on β-Ga 2 O 3 thin-film heterojunction structure can be practically used to detect weak solar-blind signals because of its high photoconductive gain.

  3. Multiple zeros of polynomials

    NASA Technical Reports Server (NTRS)

    Wood, C. A.

    1974-01-01

    For polynomials of higher degree, iterative numerical methods must be used. Four iterative methods are presented for approximating the zeros of a polynomial using a digital computer. Newton's method and Muller's method are two well known iterative methods which are presented. They extract the zeros of a polynomial by generating a sequence of approximations converging to each zero. However, both of these methods are very unstable when used on a polynomial which has multiple zeros. That is, either they fail to converge to some or all of the zeros, or they converge to very bad approximations of the polynomial's zeros. This material introduces two new methods, the greatest common divisor (G.C.D.) method and the repeated greatest common divisor (repeated G.C.D.) method, which are superior methods for numerically approximating the zeros of a polynomial having multiple zeros. These methods were programmed in FORTRAN 4 and comparisons in time and accuracy are given.

  4. Measurement of muon plus proton final states in muon neutrinos interactions on CH at 4.2 GeV

    NASA Astrophysics Data System (ADS)

    Rakotondravohitra, Laza; Minerva Collaboration

    2015-04-01

    MINERvA (Main INjector Experiment for v-A) is a neutrino scattering experiment in Fermilab's NuMI high-intensity neutrino beam. MINERvA was designed to make precision measurements of neutrino and antineutrino cross sections on a variety of materials including plastic scintillator(CH), C, Fe, Pb, He and water. We present a result of charged-current muon neutrino scattering on hydrocarbon (CH) at an average neutrino energy of 4.2 GeV in which the final state includes a muon, at least one proton, and no pions exiting the nucleus . Although this signature has the topology of neutrino quasielastic scattering from neutrons, the event sample contains contributions from both quasielastic and inelastic processes where pions are absorbed in the nucleus.

  5. Zero-mode waveguides

    DOEpatents

    Levene, Michael J.; Korlach, Jonas; Turner, Stephen W.; Craighead, Harold G.; Webb, Watt W.

    2007-02-20

    The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

  6. Critical point wetting drop tower experiment

    NASA Technical Reports Server (NTRS)

    Kaukler, William F.

    1990-01-01

    The 100 m Drop Tower at NASA-Marshall was used to provide the step change in acceleration from 1.0 to 0.0005 g. An inter-fluid meniscus oscillates vertically within a cylindrical container when suddenly released from earth's gravity and taken into a microgravity environment. Oscillations damp out from energy dissipative mechanisms such as viscosity and interfacial friction. Damping of the oscillations by the later mechanism is affected by the nature of the interfacial junction between the fluid-fluid interface and the container wall. In earlier stages of the project, the meniscus shape which developed during microgravity conditions was applied to evaluations of wetting phenomena near the critical temperature. Variations in equilibrium contact angle against the container wall were expected to occur under critical wetting conditions. However, it became apparent that the meaningful phenomenon was the damping of interfacial oscillations. This latter concept makes up the bulk of this report. Perfluoromethyl cyclohexane and isopropanol in glass were the materials used for the experiment. The wetting condition of the fluids against the wall changes at the critical wetting transition temperature. This change in wetting causes a change in the damping characteristics of the interfacial excursions during oscillation and no measurable change in contact angle. The effect of contact line friction measured above and below the wetting transition temperature was to increase the period of vertical oscillation for the vapor-liquid interface when below the wetting transition temperature.

  7. GROWTH OF THE INTERNATIONAL CRITICALITY SAFETY AND REACTOR PHYSICS EXPERIMENT EVALUATION PROJECTS

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

    J. Blair Briggs; John D. Bess; Jim Gulliford

    2011-09-01

    Since the International Conference on Nuclear Criticality Safety (ICNC) 2007, the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and the International Reactor Physics Experiment Evaluation Project (IRPhEP) have continued to expand their efforts and broaden their scope. Eighteen countries participated on the ICSBEP in 2007. Now, there are 20, with recent contributions from Sweden and Argentina. The IRPhEP has also expanded from eight contributing countries in 2007 to 16 in 2011. Since ICNC 2007, the contents of the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments1' have increased from 442 evaluations (38000 pages), containing benchmark specifications for 3955 critical ormore » subcritical configurations to 516 evaluations (nearly 55000 pages), containing benchmark specifications for 4405 critical or subcritical configurations in the 2010 Edition of the ICSBEP Handbook. The contents of the Handbook have also increased from 21 to 24 criticality-alarm-placement/shielding configurations with multiple dose points for each, and from 20 to 200 configurations categorized as fundamental physics measurements relevant to criticality safety applications. Approximately 25 new evaluations and 150 additional configurations are expected to be added to the 2011 edition of the Handbook. Since ICNC 2007, the contents of the 'International Handbook of Evaluated Reactor Physics Benchmark Experiments2' have increased from 16 different experimental series that were performed at 12 different reactor facilities to 53 experimental series that were performed at 30 different reactor facilities in the 2011 edition of the Handbook. Considerable effort has also been made to improve the functionality of the searchable database, DICE (Database for the International Criticality Benchmark Evaluation Project) and verify the accuracy of the data contained therein. DICE will be discussed in separate papers at ICNC 2011. The status of the ICSBEP and

  8. Transitioning to Zero Freshwater Withdrawal for Thermoelectric Generation

    NASA Astrophysics Data System (ADS)

    Macknick, J.; Tidwell, V. C.; Zemlick, K. M.; Sanchez, J.; Woldeyesus, T.

    2013-12-01

    The electricity sector is the largest withdrawer of freshwater in the United States. The primary demand for water from the electricity sector is for cooling thermoelectric power plants. Droughts and potential changes in water resources resulting from climate change pose important risks to thermoelectric power production in the United States. Power plants can minimize risk in a variety of ways. One method of reducing risk is to move away from dependency on freshwater resources. Here a scoping level analysis is performed to identify the technical tradeoffs and initial cost estimates for retrofitting all existing steam-powered generation to achieve zero freshwater withdrawal. Specifically, the conversion of existing freshwater-cooled plants to dry cooling or a wet cooling system utilizing non-potable water is considered. The least cost alternative is determined for each of the 1,178 freshwater using power plants in the United States. The use of non-potable water resources, such as municipal wastewater and shallow brackish groundwater, is considered based on the availability and proximity of those resources to the power plant, as well as the costs to transport and treat those resources to an acceptable level. The projected increase in levelized cost of electricity due to power plant retrofits ranges roughly from 0.20 to 20/MWh with a median value of 3.53/MWh. With a wholesale price of electricity running about 35/MWh, many retrofits could be accomplished at levels that would add less than 10% to current power plant generation expenses. Such retrofits could alleviate power plant vulnerabilities to thermal discharge limits in times of drought (particularly in the East) and would save 3.2 Mm3/d of freshwater consumption in watersheds with limited water availability (principally in the West). The estimated impact of retrofits on wastewater and brackish water supply is minimal requiring only a fraction of the available resource. Total parasitic energy requirements to

  9. High-power S-band experiment study: Objectives, description, planning and operation of experiment for ATS-G spacecraft

    NASA Technical Reports Server (NTRS)

    Walp, R. M.

    1972-01-01

    The results of a study to develop and define requirements for the high power S-band experiment for the ATS-G are summarized. The objectives of the experiment are: (1) to demonstrate high power technology at S-band frequencies in orbiting spacecraft, (2) to employ high power carrier from the spacecraft for conducting interference measurements with Instructional Television Fixed Service systems, and (3) to provide means for performing educationally oriented applications experiments. Experiment organization and operation, and hardware for flight on the ATS-G spacecraft are described. Earth stations designed for the experiment as well as other special ground equipment are also described.

  10. Wheelchair users' perceptions of and experiences with power assist wheels.

    PubMed

    Giacobbi, Peter R; Levy, Charles E; Dietrich, Frederick D; Winkler, Sandra Hubbard; Tillman, Mark D; Chow, John W

    2010-03-01

    To assess wheelchair users' perceptions of and experiences with power assist wheels using qualitative interview methods. Qualitative evaluations were conducted in a laboratory setting with a focus on users' experiences using power assist wheel in their naturalistic environments. Participants consisted of seven women and 13 men (M(age) = 42.75, SD = 14.68) that included one African American, one Hispanic, 17 whites, and one individual from Zambia. Qualitative interviews were conducted before, during, and after use of a power assist wheel. Main outcome measures included the wheelchair users' evaluations and experiences related to the use of power assist wheels. The primary evaluations included wheeling on challenging terrains, performance of novel activities, social/family aspects, fatigue, and pain. These descriptions indicated that most participants perceived positive experiences with the power assist wheels, including access to new and different activities. Secondary evaluations indicated that the unit was cumbersome and prohibitive for some participants because of difficulties with transport in and out of a vehicle and battery life. Most participants felt that power assist wheels provided more independence and social opportunities. The power assist wheel seems to offer physical and social benefits for most wheelers. Clinicians should consider users' home environment and overall life circumstances before prescribing.

  11. Advanced power analysis methodology targeted to the optimization of a digital pixel readout chip design and its critical serial powering system

    NASA Astrophysics Data System (ADS)

    Marconi, S.; Orfanelli, S.; Karagounis, M.; Hemperek, T.; Christiansen, J.; Placidi, P.

    2017-02-01

    A dedicated power analysis methodology, based on modern digital design tools and integrated with the VEPIX53 simulation framework developed within RD53 collaboration, is being used to guide vital choices for the design and optimization of the next generation ATLAS and CMS pixel chips and their critical serial powering circuit (shunt-LDO). Power consumption is studied at different stages of the design flow under different operating conditions. Significant effort is put into extensive investigations of dynamic power variations in relation with the decoupling seen by the powering network. Shunt-LDO simulations are also reported to prove the reliability at the system level.

  12. Zero Liquid Discharge (ZLD) System for Flue-Gas Derived Water From Oxy-Combustion Process

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

    Sivaram Harendra; Danylo Oryshchyn; Thomas Ochs

    2011-10-16

    Researchers at the National Energy Technology Laboratory (NETL) located in Albany, Oregon, have patented a process - Integrated Pollutant Removal (IPR) that uses off-the-shelf technology to produce a sequestration ready CO{sub 2} stream from an oxy-combustion power plant. Capturing CO{sub 2} from fossil-fuel combustion generates a significant water product which can be tapped for use in the power plant and its peripherals. Water condensed in the IPR{reg_sign} process may contain fly ash particles, sodium (from pH control), and sulfur species, as well as heavy metals, cations and anions. NETL is developing a treatment approach for zero liquid discharge while maximizingmore » available heat from IPR. Current treatment-process steps being studied are flocculation/coagulation, for removal of cations and fine particles, and reverse osmosis, for anion removal as well as for scavenging the remaining cations. After reverse osmosis process steps, thermal evaporation and crystallization steps will be carried out in order to build the whole zero liquid discharge (ZLD) system for flue-gas condensed wastewater. Gypsum is the major product from crystallization process. Fast, in-line treatment of water for re-use in IPR seems to be one practical step for minimizing water treatment requirements for CO{sub 2} capture. The results obtained from above experiments are being used to build water treatment models.« less

  13. Experiments in Wave Record Analysis.

    DTIC Science & Technology

    1980-09-01

    manipulation of wave records in digital form to produce a power density spectrum (PDS) with great efficiency. The PDS gives a presentation of the...instantaneous surface elevation digital points (the zero level reference). The individual period, Ti, was taken as the time difference between two successive...CONCLUSIONS This thesis presents the results of experiments in the analysis of ocean wave records. For this purpose 19 digitized records obtained from a wave

  14. The Phoretic Motion Experiment (PME) definition phase

    NASA Technical Reports Server (NTRS)

    Eaton, L. R.; Neste, S. L. (Editor)

    1982-01-01

    The aerosol generator and the charge flow devices (CFD) chamber which were designed for zero-gravity operation was analyzed. Characteristics of the CFD chamber and aerosol generator which would be useful for cloud physics experimentation in a one-g as well as a zero-g environment are documented. The Collision type of aerosol generator is addressed. Relationships among the various input and output parameters are derived and subsequently used to determine the requirements on the controls of the input parameters to assure a given error budget of an output parameter. The CFD chamber operation in a zero-g environment is assessed utilizing a computer simulation program. Low nuclei critical supersaturation and high experiment accuracies are emphasized which lead to droplet growth times extending into hundreds of seconds. The analysis was extended to assess the performance constraints of the CFD chamber in a one-g environment operating in the horizontal mode.

  15. Hydrogen-oxygen driven Zero Emissions bus drives around KSC Visitor Complex

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The Zero Emissions (ZE) transit bus passes a mock-up orbiter named Explorer on a trek through the KSC Visitor Complex. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. The ZE bus is being used on tour routes at the KSC Visitor Complex for two days to introduce the public to the concept.

  16. Acceleration display system for aircraft zero-gravity research

    NASA Technical Reports Server (NTRS)

    Millis, Marc G.

    1987-01-01

    The features, design, calibration, and testing of Lewis Research Center's acceleration display system for aircraft zero-gravity research are described. Specific circuit schematics and system specifications are included as well as representative data traces from flown trajectories. Other observations learned from developing and using this system are mentioned where appropriate. The system, now a permanent part of the Lewis Learjet zero-gravity program, provides legible, concise, and necessary guidance information enabling pilots to routinely fly accurate zero-gravity trajectories. Regular use of this system resulted in improvements of the Learjet zero-gravity flight techniques, including a technique to minimize later accelerations. Lewis Gates Learjet trajectory data show that accelerations can be reliably sustained within 0.01 g for 5 consecutive seconds, within 0.02 g for 7 consecutive seconds, and within 0.04 g for up to 20 second. Lewis followed the past practices of acceleration measurement, yet focussed on the acceleration displays. Refinements based on flight experience included evolving the ranges, resolutions, and frequency responses to fit the pilot and the Learjet responses.

  17. Evaluation of Fission Product Critical Experiments and Associated Biases for Burnup Credit Validation

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

    Mueller, Don; Rearden, Bradley T; Reed, Davis Allan

    2010-01-01

    One of the challenges associated with implementation of burnup credit is the validation of criticality calculations used in the safety evaluation; in particular the availability and use of applicable critical experiment data. The purpose of the validation is to quantify the relationship between reality and calculated results. Validation and determination of bias and bias uncertainty require the identification of sets of critical experiments that are similar to the criticality safety models. A principal challenge for crediting fission products (FP) in a burnup credit safety evaluation is the limited availability of relevant FP critical experiments for bias and bias uncertainty determination.more » This paper provides an evaluation of the available critical experiments that include FPs, along with bounding, burnup-dependent estimates of FP biases generated by combining energy dependent sensitivity data for a typical burnup credit application with the nuclear data uncertainty information distributed with SCALE 6. A method for determining separate bias and bias uncertainty values for individual FPs and illustrative results is presented. Finally, a FP bias calculation method based on data adjustment techniques and reactivity sensitivity coefficients calculated with the SCALE sensitivity/uncertainty tools and some typical results is presented. Using the methods described in this paper, the cross-section bias for a representative high-capacity spent fuel cask associated with the ENDF/B-VII nuclear data for 16 most important stable or near stable FPs is predicted to be no greater than 2% of the total worth of the 16 FPs, or less than 0.13 % k/k.« less

  18. The Trouble with Zero

    ERIC Educational Resources Information Center

    Lewis, Robert

    2015-01-01

    The history of the number zero is an interesting one. In early times, zero was not used as a number at all, but instead was used as a place holder to indicate the position of hundreds and tens. This article briefly discusses the history of zero and challenges the thinking where divisions using zero are used.

  19. Temporal framing and the hidden-zero effect: rate-dependent outcomes on delay discounting.

    PubMed

    Naudé, Gideon P; Kaplan, Brent A; Reed, Derek D; Henley, Amy J; DiGennaro Reed, Florence D

    2018-05-01

    Recent research suggests that presenting time intervals as units (e.g., days) or as specific dates, can modulate the degree to which humans discount delayed outcomes. Another framing effect involves explicitly stating that choosing a smaller-sooner reward is mutually exclusive to receiving a larger-later reward, thus presenting choices as an extended sequence. In Experiment 1, participants (N = 201) recruited from Amazon Mechanical Turk completed the Monetary Choice Questionnaire in a 2 (delay framing) by 2 (zero framing) design. Regression suggested a main effect of delay, but not zero, framing after accounting for other demographic variables and manipulations. We observed a rate-dependent effect for the date-framing group, such that those with initially steep discounting exhibited greater sensitivity to the manipulation than those with initially shallow discounting. Subsequent analyses suggest these effects cannot be explained by regression to the mean. Experiment 2 addressed the possibility that the null effect of zero framing was due to within-subject exposure to the hidden- and explicit-zero conditions. A new Amazon Mechanical Turk sample completed the Monetary Choice Questionnaire in either hidden- or explicit-zero formats. Analyses revealed a main effect of reward magnitude, but not zero framing, suggesting potential limitations to the generality of the hidden-zero effect. © 2018 Society for the Experimental Analysis of Behavior.

  20. Implementation and Critical Assessment of the Flipped Classroom Experience

    ERIC Educational Resources Information Center

    Scheg, Abigail G., Ed.

    2015-01-01

    In the past decade, traditional classroom teaching models have been transformed in order to better promote active learning and learner engagement. "Implementation and Critical Assessment of the Flipped Classroom Experience" seeks to capture the momentum of non-traditional teaching methods and provide a necessary resource for individuals…

  1. Apollo experience report: Power generation system

    NASA Technical Reports Server (NTRS)

    Bell, D., III; Plauche, F. M.

    1973-01-01

    A comprehensive review of the design philosophy and experience of the Apollo electrical power generation system is presented. The review of the system covers a period of 8 years, from conception through the Apollo 12 lunar-landing mission. The program progressed from the definition phase to hardware design, system development and qualification, and, ultimately, to the flight phase. Several problems were encountered; however, a technology evolved that enabled resolution of the problems and resulted in a fully manrated power generation system. These problems are defined and examined, and the corrective action taken is discussed. Several recommendations are made to preclude similar occurrences and to provide a more reliable fuel-cell power system.

  2. Testing of a Spray-Bar Zero Gravity Cryogenic Vent System for Upper Stages

    NASA Technical Reports Server (NTRS)

    Lak, Tibor; Flachbart, Robin; Nguyen, Han; Martin, James

    1999-01-01

    spray bar configuration is that pressure reduction is achieved independent of liquid and vapor location, thereby enhancing the applicability of normal gravity test data to zero gravity conditions. The in-tank components are minimized with the proposed TVS design. Because the recirculation pump is external to the tank, no electrical power penetration of the tank is required for pump or valve operation. This is especially desirable for L02 tanks since the presence of an electrical ignition source in oxygen represents a critical failure mode. Also, since the critical components (pump, motor, valve, orifice) are external to the tank, system checkout and ground servicing/replacement are easier. For zero-g operation, component replacement external to the tank may be a significant benefit. In addition to satisfying the zero g TVS design objectives, the TVS concept tested offers additional benefits to the integrated subcritical cryogenic storage and launch system.

  3. Zero/zero rotorcraft certification issues. Volume 3: Working group results

    NASA Technical Reports Server (NTRS)

    Adams, Richard J.

    1988-01-01

    This report analyzes the Zero/Zero Rotorcraft Certification Issues from the perspectives of manufacturers, operators, researchers and the FAA. The basic premise behind this analysis is that zero/zero, or at least extremely low visibility, rotorcraft operations are feasible today from both a technological and an operational standpoint. The questions and issues that need to be resolved are: What certification requirements do we need to ensure safety. Can we develop procedures which capitalize on the performance and maneuvering capabilities unique to rotorcraft. Will extremely low visibility operations be economically feasible. This is Volume 3 of three. It provides the issue-by-issue deliberations of the experts involved in the Working Groups assigned to deal with them in the Issues Forum.

  4. Theoretical modeling of critical temperature increase in metamaterial superconductors

    NASA Astrophysics Data System (ADS)

    Smolyaninov, Igor I.; Smolyaninova, Vera N.

    2016-05-01

    Recent experiments have demonstrated that the metamaterial approach is capable of a drastic increase of the critical temperature Tc of epsilon near zero (ENZ) metamaterial superconductors. For example, tripling of the critical temperature has been observed in Al -A l2O3 ENZ core-shell metamaterials. Here, we perform theoretical modeling of Tc increase in metamaterial superconductors based on the Maxwell-Garnett approximation of their dielectric response function. Good agreement is demonstrated between theoretical modeling and experimental results in both aluminum- and tin-based metamaterials. Taking advantage of the demonstrated success of this model, the critical temperature of hypothetic niobium-, Mg B2- , and H2S -based metamaterial superconductors is evaluated. The Mg B2 -based metamaterial superconductors are projected to reach the liquid nitrogen temperature range. In the case of a H2S -based metamaterial Tc appears to reach ˜250 K.

  5. The metaphor of experience and the experience of metaphor: critical reflection on a contemplative process toward aliveness and compassion.

    PubMed

    Kuchan, Karen L

    2009-01-01

    An epistemological web invites critical reflection and the possibility of new ideas emerging in the space between experience and different ways of thinking. A web offers a postmodern method of a hermeneutic of experience and a way of knowing that creates space for a robust, flexible, dynamic process of critical reflection and discovery. The following article utilizes an inter-textual epistemological web (see Figure 1, p. 4) to answer the question, "Do metaphors of experience and experiences of metaphor during contemplative healing prayer with a spiritual director nurture a transformational process toward aliveness and compassion?" How can one discover and communicate this reality in dialog with Hebrew scripture, psychoanalytic theory, affective neuroscience and ways of thinking about contemplative transformation?

  6. Optically induced metal-to-dielectric transition in Epsilon-Near-Zero metamaterials

    PubMed Central

    Kaipurath, R. M.; Pietrzyk, M.; Caspani, L.; Roger, T.; Clerici, M.; Rizza, C.; Ciattoni, A.; Di Falco, A.; Faccio, D.

    2016-01-01

    Epsilon-Near-Zero materials exhibit a transition in the real part of the dielectric permittivity from positive to negative value as a function of wavelength. Here we study metal-dielectric layered metamaterials in the homogenised regime (each layer has strongly subwavelength thickness) with zero real part of the permittivity in the near-infrared region. By optically pumping the metamaterial we experimentally show that close to the Epsilon-Near-Zero (ENZ) wavelength the permittivity exhibits a marked transition from metallic (negative permittivity) to dielectric (positive permittivity) as a function of the optical power. Remarkably, this transition is linear as a function of pump power and occurs on time scales of the order of the 100 fs pump pulse that need not be tuned to a specific wavelength. The linearity of the permittivity increase allows us to express the response of the metamaterial in terms of a standard third order optical nonlinearity: this shows a clear inversion of the roles of the real and imaginary parts in crossing the ENZ wavelength, further supporting an optically induced change in the physical behaviour of the metamaterial. PMID:27292270

  7. Jordanian survivors' experiences of recovery from critical illness: a qualitative study.

    PubMed

    Abdalrahim, M S; Zeilani, R S

    2014-12-01

    Despite the fact that a lot of patients consider their discharge from hospitals as a positive sign of progress towards regained health, many of them start suffering from physical, psychological and social problems after discharge from intensive care units. This study aims to describe the experiences of Jordanian survivors of critical illnesses 3 months after discharge from a hospital intensive care unit. A descriptive qualitative approach was used to involve 18 Jordanian patients from two hospitals in a major Jordanian city using open-ended interviews. Interview transcripts were analysed using content analysis method. Three main themes have emerged from the data: (1) new meaning of life; (2) different perspectives on the meaning of life, and (3) struggle for role identity. The sample was chosen from one city in Jordan; longitudinal study might help identify the change in patients' experiences over time. Patients described the discharge from the intensive care unit as a means of rescue from death; they began to value their spiritual and religious rituals. Negative traumatic experiences hindered the patients' recovery process. During recovery, patients struggled to resume their power and role in family. This study emphasizes the importance of providing care according to the patient's individual needs, related to their cultural and spiritual milieu; there is a need to develop follow-up services for ICU survivors within a national health policy. Further educational and training programmes in the patient's issues after discharge from hospital are needed. This will definitely help nurses care after this patient group. © 2014 International Council of Nurses.

  8. Zero Pearson coefficient for strongly correlated growing trees

    NASA Astrophysics Data System (ADS)

    Dorogovtsev, S. N.; Ferreira, A. L.; Goltsev, A. V.; Mendes, J. F. F.

    2010-03-01

    We obtained Pearson’s coefficient of strongly correlated recursive networks growing by preferential attachment of every new vertex by m edges. We found that the Pearson coefficient is exactly zero in the infinite network limit for the recursive trees (m=1) . If the number of connections of new vertices exceeds one (m>1) , then the Pearson coefficient in the infinite networks equals zero only when the degree distribution exponent γ does not exceed 4. We calculated the Pearson coefficient for finite networks and observed a slow power-law-like approach to an infinite network limit. Our findings indicate that Pearson’s coefficient strongly depends on size and details of networks, which makes this characteristic virtually useless for quantitative comparison of different networks.

  9. Zero Pearson coefficient for strongly correlated growing trees.

    PubMed

    Dorogovtsev, S N; Ferreira, A L; Goltsev, A V; Mendes, J F F

    2010-03-01

    We obtained Pearson's coefficient of strongly correlated recursive networks growing by preferential attachment of every new vertex by m edges. We found that the Pearson coefficient is exactly zero in the infinite network limit for the recursive trees (m=1). If the number of connections of new vertices exceeds one (m>1), then the Pearson coefficient in the infinite networks equals zero only when the degree distribution exponent gamma does not exceed 4. We calculated the Pearson coefficient for finite networks and observed a slow power-law-like approach to an infinite network limit. Our findings indicate that Pearson's coefficient strongly depends on size and details of networks, which makes this characteristic virtually useless for quantitative comparison of different networks.

  10. Powerful Learning Experiences and Suzuki Music Teachers

    ERIC Educational Resources Information Center

    Reuning-Hummel, Carrie; Meyer, Allison; Rowland, Gordon

    2016-01-01

    Powerful Learning Experiences (PLEs) of Suzuki music teachers were examined in this fifth study in a series. The definition of a PLE is: "Experiences that stand out in memory because of their high quality, their impact on one's thoughts and actions over time, and their transfer to a wide range of contexts and circumstances." Ten…

  11. Dirac directional emission in anisotropic zero refractive index photonic crystals.

    PubMed

    He, Xin-Tao; Zhong, Yao-Nan; Zhou, You; Zhong, Zhi-Chao; Dong, Jian-Wen

    2015-08-14

    A certain class of photonic crystals with conical dispersion is known to behave as isotropic zero-refractive-index medium. However, the discrete building blocks in such photonic crystals are limited to construct multidirectional devices, even for high-symmetric photonic crystals. Here, we show multidirectional emission from low-symmetric photonic crystals with semi-Dirac dispersion at the zone center. We demonstrate that such low-symmetric photonic crystal can be considered as an effective anisotropic zero-refractive-index medium, as long as there is only one propagation mode near Dirac frequency. Four kinds of Dirac multidirectional emitters are achieved with the channel numbers of five, seven, eleven, and thirteen, respectively. Spatial power combination for such kind of Dirac directional emitter is also verified even when multiple sources are randomly placed in the anisotropic zero-refractive-index photonic crystal.

  12. Dirac directional emission in anisotropic zero refractive index photonic crystals

    PubMed Central

    He, Xin-Tao; Zhong, Yao-Nan; Zhou, You; Zhong, Zhi-Chao; Dong, Jian-Wen

    2015-01-01

    A certain class of photonic crystals with conical dispersion is known to behave as isotropic zero-refractive-index medium. However, the discrete building blocks in such photonic crystals are limited to construct multidirectional devices, even for high-symmetric photonic crystals. Here, we show multidirectional emission from low-symmetric photonic crystals with semi-Dirac dispersion at the zone center. We demonstrate that such low-symmetric photonic crystal can be considered as an effective anisotropic zero-refractive-index medium, as long as there is only one propagation mode near Dirac frequency. Four kinds of Dirac multidirectional emitters are achieved with the channel numbers of five, seven, eleven, and thirteen, respectively. Spatial power combination for such kind of Dirac directional emitter is also verified even when multiple sources are randomly placed in the anisotropic zero-refractive-index photonic crystal. PMID:26271208

  13. Carbon loaded Teflon (CLT): a power density meter for biological experiments using millimeter waves.

    PubMed

    Allen, Stewart J; Ross, James A

    2007-01-01

    The standard technique for measurement of millimeter wave fields utilizes an open-ended waveguide attached to a HP power meter. The alignment of the waveguide with the propagation (K) vector is critical to making accurate measurements. Using this technique, it is difficult and time consuming to make a detailed map of average incident power density over areas of biological interest and the spatial resolution of this instrument does not allow accurate measurements in non-uniform fields. For biological experiments, it is important to know the center field average incident power density and the distribution over the exposed area. Two 4 ft x 4 ft x 1/32 inch sheets of carbon loaded Teflon (CLT) (one 15% carbon and one 25% carbon) were procured and a series of tests to determine the usefulness of CLT in defining fields in the millimeter wavelength range was initiated. Since the CLT was to be used both in the laboratory, where the environment was well controlled, and in the field, where the environment could not be controlled, tests were made to determine effects of change in environmental conditions on ability to use CLT as a millimeter wave dosimeter. The empirical results of this study indicate CLT to be an effective dosimeter for biological experiments both in the laboratory and in the field.

  14. Testing in Support of Fission Surface Power System Qualification

    NASA Technical Reports Server (NTRS)

    Houts, Mike; Bragg-Sitton, Shannon; Godfroy, Tom; Martin, Jim; Pearson, Boise; VanDyke, Melissa

    2007-01-01

    The strategy for qualifying a FSP system could have a significant programmatic impact. The US has not qualified a space fission power system since launch of the SNAP-10A in 1965. This paper explores cost-effective options for obtaining data that would be needed for flight qualification of a fission system. Qualification data could be obtained from both nuclear and non-nuclear testing. The ability to perform highly realistic nonnuclear testing has advanced significantly throughout the past four decades. Instrumented thermal simulators were developed during the 1970s and 1980s to assist in the development, operation, and assessment of terrestrial fission systems. Instrumented thermal simulators optimized for assisting in the development, operation, and assessment of modern FSP systems have been under development (and utilized) since 1998. These thermal simulators enable heat from fission to be closely mimicked (axial power profile, radial power profile, temperature, heat flux, etc.) and extensive data to be taken from the core region. For transient testing, pin power during a transient is calculated based on the reactivity feedback that would occur given measured values of test article temperature and/or dimensional changes. The reactivity feedback coefficients needed for the test are either calculated or measured using cold/warm zero-power criticals. In this way non-nuclear testing can be used to provide very realistic information related to nuclear operation. Non-nuclear testing can be used at all levels, including component, subsystem, and integrated system testing. FSP fuels and materials are typically chosen to ensure very high confidence in operation at design burnups, fluences, and temperatures. However, facilities exist (e.g. ATR, HFIR) for affordably performing in-pile fuel and materials irradiations, if such testing is desired. Ex-core materials and components (such as alternator materials, control drum drives, etc.) could be irradiated in university or DOE

  15. Energy density engineering via zero-admittance domains in all-dielectric stratified materials

    NASA Astrophysics Data System (ADS)

    Amra, Claude; Zerrad, Myriam; Lemarchand, Fabien; Lereu, Aude; Passian, Ali; Zapien, Juan Antonio; Lequime, Michel

    2018-02-01

    Emerging photonic, sensing, and quantum applications require high fields and tight localization but low power consumption. Spatial, spectral, and magnitude control of electromagnetic fields is of key importance for enabling experiments in atomic, molecular, and optical physics. We introduce the concept of zero-admittance domains as a mechanism for tailoring giant optical fields bound within or on the surface of dielectric media. The described mechanism permits the creation of highly localized fields of extreme amplitudes simultaneously for incident photons of multiple wavelengths and incidence angles but arbitrary polarization states. No material constraints are placed upon the bounding media. Both intrinsic and extrinsic potential practical limitations of the predicted field enhancement are analyzed and applications relevant to optical sensors and microsources are briefly discussed.

  16. IS WAITING THE HARDEST PART? A CRITICAL STUDY OF THE EXPERIENCE OF WOMEN AWAITING BREAST BIOPSY RESULTS.

    PubMed

    Hodgkinson, T; Govender, C; Rayne, S

    2017-06-01

    Most previous research efforts have focused on the psychological effects of receiving a cancer diagnosis rather than the period of waiting for definitive Results. Early detection of cancer is directly linked to successful treatment regimes, yet these procedures evoke significant anxiety in patients. The long wait for medical test Results in state health institutions, with one of the possible outcomes being a cancer diagnosis, means that the days of waiting can induce emotional distress before the diagnosis has even been given. Eight research collaborators were invited to, in their own voice, shed light on their individual experiences while waiting for their biopsy Results to gain an understanding of the experiences of each collaborator by letting her tell her story and to explore the possibility of shared experience between collaborators. Research collaborators at a local, government hospital kept a journal for the two-week waiting period for their biopsy Results. Shortly before receiving their Results, they took part in a short semi-structured interview to inquire about their waiting. The theoretical framework used for data interpretation is critical theory focusing on the structures within society and healthcare systems that impact on the experience of waiting. The undercurrent of critical commentary about the roles of the gender, economic, political and cultural factors that contribute to the screening experience for women in South Africa helps to shed light on the complex forces at play within the procedures. The Results indicate that for some women waiting provokes significant psychological stress which manifests in multiple psychological processes including the psychological bracing phenomenon, denial, suppression and negation of their emotional experience all perpetuated by the structures of power within the health care system. More understanding of the psychological experience of awaiting a cancer diagnosis is required and there is an important place for

  17. Zero: A "None" Number?

    ERIC Educational Resources Information Center

    Anthony, Glenda J.; Walshaw, Margaret A.

    2004-01-01

    This article discusses the challenges students face in making sense of zero as a number. A range of different student responses to a computation problem involving zero reveal students' different understandings of zero.

  18. Zero-Gravity Research Facility Drop Test (2/4)

    NASA Technical Reports Server (NTRS)

    1995-01-01

    An experiment vehicle plunges into the deceleration pit at the end of a 5.18-second drop in the Zero-Gravity Research Facility at NASA's Glenn Research Center. The Zero-Gravity Research Facility was developed to support microgravity research and development programs that investigate various physical sciences, materials, fluid physcis, and combustion and processing systems. Payloads up to 1 meter in diameter and 455 kg in weight can be accommodated. The facility has a 145-meter evacuated shaft to ensure a disturbance-free drop. This is No. 2 of a sequence of 4 images. (Credit: NASA/Glenn Research Center)

  19. Zero-Gravity Research Facility Drop Test (1/4)

    NASA Technical Reports Server (NTRS)

    1995-01-01

    An experiment vehicle plunges into the deceleration pit at the end of a 5.18-second drop in the Zero-Gravity Research Facility at NASA's Glenn Research Center. The Zero-Gravity Research Facility was developed to support microgravity research and development programs that investigate various physical sciences, materials, fluid physics, and combustion and processing systems. Payloads up to 1 meter in diameter and 455 kg in weight can be accommodated. The facility has a 145-meter evacuated shaft to ensure a disturbance-free drop. This is No.1 of a sequence of 4 images. (Credit: NASA/Glenn Research Center)

  20. Zero-Gravity Research Facility Drop Test (3/4)

    NASA Technical Reports Server (NTRS)

    1995-01-01

    An experiment vehicle plunges into the deceleration at the end of a 5.18-second drop in the Zero-Gravity Research Facility at NASA's Glenn Research Center. The Zero-Gravity Research Facility was developed to support microgravity research and development programs that investigate various physical sciences, materials, fluid physics, and combustion and processing systems. Payloads up to one-meter in diameter and 455 kg in weight can be accommodated. The facility has a 145-meter evacuated shaft to ensure a disturbance-free drop. This is No. 3 of a sequence of 4 images. (Credit: NASA/Glenn Research Center)

  1. Zero-Gravity Research Facility Drop Test (4/4)

    NASA Technical Reports Server (NTRS)

    1995-01-01

    An experiment vehicle plunges into the deceleration pit at the end of a 5.18-second drop in the Zero-Gravity Research Facility at NASA's Glenn Research Center. The Zero-Gravity Research Facility was developed to support microgravity research and development programs that investigate various physical sciences, materials, fluid physics, and combustion and processing systems. Payloads up to one meter in diameter and 455 kg in weight can be accommodated. The facility has a 145-meter evacuated shaft to ensure a disturbance-free drop. This is No. 4 of a sequence of 4 images. (Credit: NASA/Glenn Research Center)

  2. Cross sections for ν μ and ν ¯ μ induced pion production on hydrocarbon in the few-GeV region using MINERvA

    DOE PAGES

    McGivern, C. L.; Le, T.; Eberly, B.; ...

    2016-09-06

    Separate samples of charged-current pion production events representing two semi-inclusive channels ν μ–CC(π +) and ν¯ μ–CC(π 0) have been obtained using neutrino and antineutrino exposures of the MINERvA detector. Distributions in kinematic variables based upon μ±-track reconstructions are analyzed and compared for the two samples. The differential cross sections for muon production angle, muon momentum, and four-momentum transfer Q 2 are reported, and cross sections versus neutrino energy are obtained. Comparisons with predictions of current neutrino event generators are used to clarify the role of the Δ(1232) and higher-mass baryon resonances in CC pion production and to show themore » importance of pion final-state interactions. For the ν μ–CC(π +) [ν¯ μ–CC(π 0)] sample, the absolute data rate is observed to lie below (above) the predictions of some of the event generators by amounts that are typically 1-to- 2σ. Furthermore, the generators are able to reproduce the shapes of the differential cross sections for all kinematic variables of either data set.« less

  3. Planning the Unplanned Experiment: Assessing the Efficacy of Standards for Safety Critical Software

    NASA Technical Reports Server (NTRS)

    Graydon, Patrick J.; Holloway, C. Michael

    2015-01-01

    We need well-founded means of determining whether software is t for use in safety-critical applications. While software in industries such as aviation has an excellent safety record, the fact that software aws have contributed to deaths illustrates the need for justi ably high con dence in software. It is often argued that software is t for safety-critical use because it conforms to a standard for software in safety-critical systems. But little is known about whether such standards `work.' Reliance upon a standard without knowing whether it works is an experiment; without collecting data to assess the standard, this experiment is unplanned. This paper reports on a workshop intended to explore how standards could practicably be assessed. Planning the Unplanned Experiment: Assessing the Ecacy of Standards for Safety Critical Software (AESSCS) was held on 13 May 2014 in conjunction with the European Dependable Computing Conference (EDCC). We summarize and elaborate on the workshop's discussion of the topic, including both the presented positions and the dialogue that ensued.

  4. Changing the Culture of Academic Medicine: Critical Mass or Critical Actors?

    PubMed

    Helitzer, Deborah L; Newbill, Sharon L; Cardinali, Gina; Morahan, Page S; Chang, Shine; Magrane, Diane

    2017-05-01

    By 2006, women constituted 34% of academic medical faculty, reaching a critical mass. Theoretically, with critical mass, culture and policy supportive of gender equity should be evident. We explore whether having a critical mass of women transforms institutional culture and organizational change. Career development program participants were interviewed to elucidate their experiences in academic health centers (AHCs). Focus group discussions were held with institutional leaders to explore their perceptions about contemporary challenges related to gender and leadership. Content analysis of both data sources revealed points of convergence. Findings were interpreted using the theory of critical mass. Two nested domains emerged: the individual domain included the rewards and personal satisfaction of meaningful work, personal agency, tensions between cultural expectations of family and academic roles, and women's efforts to work for gender equity. The institutional domain depicted the sociocultural environment of AHCs that shaped women's experience, both personally and professionally, lack of institutional strategies to engage women in organizational initiatives, and the influence of one leader on women's ascent to leadership. The predominant evidence from this research demonstrates that the institutional barriers and sociocultural environment continue to be formidable obstacles confronting women, stalling the transformational effects expected from achieving a critical mass of women faculty. We conclude that the promise of critical mass as a turning point for women should be abandoned in favor of "critical actor" leaders, both women and men, who individually and collectively have the commitment and power to create gender-equitable cultures in AHCs.

  5. 3D Printing in Zero-G ISS Technology Demonstration

    NASA Technical Reports Server (NTRS)

    Werkheiser, Niki; Cooper, Kenneth C.; Edmunson, Jennifer E.; Dunn, Jason; Snyder, Michael

    2013-01-01

    The National Aeronautics and Space Administration (NASA) has a long term strategy to fabricate components and equipment on-demand for manned missions to the Moon, Mars, and beyond. To support this strategy, NASA's Marshall Space Fligth Center (MSFC) and Made in Space, Inc. are developing the 3D Printing In Zero-G payload as a Technology Demonstration for the International Space Station (ISS). The 3D Printing In Zero-G experiment ('3D Print') will be the frst machine to perform 3D printing in space.

  6. Middeck zero-gravity dynamics experiment - Comparison of ground and flight test data

    NASA Technical Reports Server (NTRS)

    Crawley, Edward F.; Barlow, Mark S.; Van Schoor, Marthinus C.; Masters, Brett; Bicos, Andrew S.

    1992-01-01

    An analytic and experimental study of the changes in the modal parameters of space structural test articles from one- to zero-gravity is presented. Deployable, erectable, and rotary modules was assembled to form three one- and two-dimensional structures, in which variations in bracing wire and rotary joint preload could be introduced. The structures were modeled as if hanging from a suspension system in one gravity, and unconstrained, as if free floating in zero-gravity. The analysis is compared with ground experimental measurements, made on a spring/wire suspension system with a nominal plunge frequency of one Hertz, and with measurements made on the Shuttle middeck. The degree of change in linear modal parameters as well as the change in nonlinear nature of the response is examined. Trends in modal parameters are presented as a function of force amplitude, joint preload, and ambient gravity level.

  7. Experimental design, power and sample size for animal reproduction experiments.

    PubMed

    Chapman, Phillip L; Seidel, George E

    2008-01-01

    The present paper concerns statistical issues in the design of animal reproduction experiments, with emphasis on the problems of sample size determination and power calculations. We include examples and non-technical discussions aimed at helping researchers avoid serious errors that may invalidate or seriously impair the validity of conclusions from experiments. Screen shots from interactive power calculation programs and basic SAS power calculation programs are presented to aid in understanding statistical power and computing power in some common experimental situations. Practical issues that are common to most statistical design problems are briefly discussed. These include one-sided hypothesis tests, power level criteria, equality of within-group variances, transformations of response variables to achieve variance equality, optimal specification of treatment group sizes, 'post hoc' power analysis and arguments for the increased use of confidence intervals in place of hypothesis tests.

  8. Sharing Power in the Classroom.

    ERIC Educational Resources Information Center

    Richard-Amato, Patricia

    2002-01-01

    Suggests that be sharing power in the classroom teachers allow the development of participatory classrooms in which all students can thrive. Examines participatory teaching and critical pedagogy, components of the participatory learning experience, manifestations of participatory teaching, an application of the language experience approach,…

  9. Heterogeneous selenite reduction by zero valent iron steel wool.

    PubMed

    Li, Ziyan; Huang, Donglin; McDonald, Louis M

    2017-02-01

    Mine drainage from the low-sulfur surface coal mines in southern West Virginia, USA, is circumneutral (pH > 6) but contains elevated selenium (Se) concentrations. Removal of selenite ions from aqueous solutions under anoxic condition at pH 6-8.5 by zero valent iron steel wool (ZVI-SW) was investigated in bench-scale kinetic experiments using wet chemical, microscopic and spectroscopic techniques (X-ray photoelectron spectroscopy). ZVI-SW could effectively and efficiently remove Se IV from solution with pH 6-8.5. A two-step removal mechanism was identified for Se IV reduction by ZVI-SW. The proposed mechanism was electrochemical reduction of Se IV by Fe 0 in an initial lag stage, followed by a faster heterogeneous reduction, mediated by an Fe II -bearing phase (hydroxide or green rust). Solution pH was a critical factor for the kinetic rate in the lag stage (0.33 h -1 for pH > 8 and 0.10 h -1 for pH 6-8). The length of lag stage was 20-30 min as determined by the time for dissolved Fe II concentration to reach 0.30 ± 0.04 mg L -1 which was critical for induction of the faster stage. About 65% of the initial Se IV was reduced to Se 0 , the primary reductive product in both stages.

  10. Droplet burning at zero G

    NASA Technical Reports Server (NTRS)

    Williams, F. A.

    1978-01-01

    Questions of the importance and feasibility of performing experiments on droplet burning at zero gravity in Spacelab were studied. Information on the physics and chemistry of droplet combustion, with attention directed specifically to the chemical kinetics, heat and mass transfer, and fluid mechanics of the phenomena involved, are presented. The work was divided into three phases, the justification, the feasibility, and the conceptual development of a preliminary design. Results from the experiments performed revealed a few new facts concerning droplet burning, notably burning rates in excess of theoretical prediction and a phenomenon of flash extinction, both likely traceable to accumulation of carbon produced by gas-phase pyrolysis in the fuel-rich zone enclosed by the reaction surface. These experiments also showed that they were primarily due to timing difficulties.

  11. Pulse Detonation Rocket Magnetohydrodynamic Power Experiment

    NASA Technical Reports Server (NTRS)

    Litchford, R. J.; Jones, J. E.; Dobson, C. C.; Cole, J. W.; Thompson, B. R.; Plemmons, D. H.; Turner, M. W.

    2003-01-01

    The production of onboard electrical power by pulse detonation engines is problematic in that they generate no shaft power; however, pulse detonation driven magnetohydrodynamic (MHD) power generation represents one intriguing possibility for attaining self-sustained engine operation and generating large quantities of burst power for onboard electrical systems. To examine this possibility further, a simple heat-sink apparatus was developed for experimentally investigating pulse detonation driven MHD generator concepts. The hydrogen oxygen fired driver was a 90 cm long stainless steel tube having a 4.5 cm square internal cross section and a short Schelkin spiral near the head end to promote rapid formation of a detonation wave. The tube was intermittently filled to atmospheric pressure and seeded with a CsOH/methanol prior to ignition by electrical spark. The driver exhausted through an aluminum nozzle having an area contraction ratio of A*/A(sub zeta) = 1/10 and an area expansion ratio of A(sub zeta)/A* = 3.2 (as limited by available magnet bore size). The nozzle exhausted through a 24-electrode segmented Faraday channel (30.5 cm active length), which was inserted into a 0.6 T permanent magnet assembly. Initial experiments verified proper drive operation with and without the nozzle attachment, and head end pressure and time resolved thrust measurements were acquired. The exhaust jet from the nozzle was interrogated using a polychromatic microwave interferometer yielding an electron number density on the order of 10(exp 12)/cm at the generator entrance. In this case, MHD power generation experiments suffered from severe near-electrode voltage drops and low MHD interaction; i.e., low flow velocity, due to an inherent physical constraint on expansion with the available magnet. Increased scaling, improved seeding techniques, higher magnetic fields, and higher expansion ratios are expected to greatly improve performance.

  12. Advance Power Technology Experiment for the Starshine 3 Satellite

    NASA Technical Reports Server (NTRS)

    Jenkins, Phillip; Scheiman, David; Wilt, David; Raffaelle, Ryne; Button, Robert; Smith, Mark; Kerslake, Thomas; Miller, Thomas; Bailey, Sheila (Technical Monitor); Hepp, A. (Technical Monitor)

    2001-01-01

    The Starshine 3 satellite will carry several power technology demonstrations. Since Starshine 3 is primarily a passive experiment and does not need electrical power to successfully complete its mission, the requirement for a highly reliable power system is greatly reduced. This creates an excellent opportunity to test new power technologies. Several government and commercial interests have teamed up to provide Starshine 3 with a small power system using state-of-the-art components. Starshine 3 will also fly novel integrated microelectronic power supplies (IWS) for evaluation.

  13. Critical Thinking and Its Relationship to Motivation, Learning Strategies, and Classroom Experience.

    ERIC Educational Resources Information Center

    Garcia, Teresa; Pintrich, Paul R.

    Critical thinking has important implications for classic learning issues such as transfer of knowledge and application of problem-solving skills to novel situations. The goal of this study was to identify some of the important correlates of critical thinking, in terms of motivation, use of cognitive learning strategies, and classroom experiences.…

  14. The experience of critically ill children: A phenomenological study of discomfort and comfort.

    PubMed

    Carnevale, Franco A; Gaudreault, Josée

    2013-01-01

    Emerging evidence indicates that critically ill children are particularly at risk for incurring significant psychological harm. Little is known about these children's actual experiences. The aim of the study was to examine children's experience of critical illness. The research question was: What are a critically ill child's sources of discomfort and comfort? Interpretive phenomenology was selected as the study's method. Children's accounts were examined to identify what they considered meaningful, in terms of their experienced discomfort and comfort. Data sources included formal and informal interviews with child-participants, drawings provided by some participants, and field-notes documenting observed non-verbal data. Twelve children were enrolled in the study, ranging from 3 to 17years of age; including four girls and eight boys. Although all participants were able to discuss the discomfort and comfort they experienced, they reported difficulties in remembering part or most of their experience. Some participants characterized their Pediatric Intensive Care Unit stay quite favourably or as "not that bad", while some described their experience unfavourably. Diverse types of discomforts were reported, including fears and worries, hurt and pain, invasive interventions, missing significant people, noise, food or eating problems, boredom, physical symptoms, as well as four additional discomforts reported by individual participants. Several sources of comfort were described, including parents, visitors and friends, hospital staff (principally nurses), stuffed animal/favourite blanket, entertainment and play, food, selected medical interventions, thinking of going home, being able to walk or run, sleep, waking up, gifts, along with two other comforts reported by individual participants. Embodiment and a tension between aloneness and being with were identified as the principal phenomena underlying these children's experiences. The findings complement existing knowledge

  15. Overview of critical risk factors in Power-Two-Wheeler safety.

    PubMed

    Vlahogianni, Eleni I; Yannis, George; Golias, John C

    2012-11-01

    Power-Two-Wheelers (PTWs) constitute a vulnerable class of road users with increased frequency and severity of accidents. The present paper focuses of the PTW accident risk factors and reviews existing literature with regard to the PTW drivers' interactions with the automobile drivers, as well as interactions with infrastructure elements and weather conditions. Several critical risk factors are revealed with different levels of influence to PTW accident likelihood and severity. A broad classification based on the magnitude and the need for further research for each risk factor is proposed. The paper concludes by discussing the importance of dealing with accident configurations, the data quality and availability, methods implemented to model risk and exposure and risk identification which are critical for a thorough understanding of the determinants of PTW safety. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Theoretical modeling of critical temperature increase in metamaterial superconductors

    NASA Astrophysics Data System (ADS)

    Smolyaninov, Igor; Smolyaninova, Vera

    Recent experiments have demonstrated that the metamaterial approach is capable of drastic increase of the critical temperature Tc of epsilon near zero (ENZ) metamaterial superconductors. For example, tripling of the critical temperature has been observed in Al-Al2O3 ENZ core-shell metamaterials. Here, we perform theoretical modelling of Tc increase in metamaterial superconductors based on the Maxwell-Garnett approximation of their dielectric response function. Good agreement is demonstrated between theoretical modelling and experimental results in both aluminum and tin-based metamaterials. Taking advantage of the demonstrated success of this model, the critical temperature of hypothetic niobium, MgB2 and H2S-based metamaterial superconductors is evaluated. The MgB2-based metamaterial superconductors are projected to reach the liquid nitrogen temperature range. In the case of an H2S-based metamaterial Tc appears to reach 250 K. This work was supported in part by NSF Grant DMR-1104676 and the School of Emerging Technologies at Towson University.

  17. Zero Gravity Research Facility User's Guide

    NASA Technical Reports Server (NTRS)

    Thompson, Dennis M.

    1999-01-01

    The Zero Gravity Research Facility (ZGF) is operated by the Space Experiments Division of the NASA John H. Glenn Research Center (GRC) for investigators sponsored by the Microgravity Science and Applications Division of NASA Headquarters. This unique facility has been utilized by scientists and engineers for reduced gravity experimentation since 1966. The ZGF has provided fundamental scientific information, has been used as an important test facility in the space flight hardware design, development, and test process, and has also been a valuable source of data in the flight experiment definition process. The purpose of this document is to provide information and guidance to prospective researchers regarding the design, buildup, and testing of microgravity experiments.

  18. Nonlinear plasma experiments in geospace with gigawatts of RF power at HAARP

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

    Sheerin, J. P., E-mail: jsheerin@emich.edu; Cohen, Morris B., E-mail: mcohen@gatech.edu

    2015-12-10

    The ionosphere is the ionized uppermost layer of our atmosphere (from 70 – 500 km altitude) where free electron densities yield peak critical frequencies in the HF (3 – 30 MHz) range. The ionosphere thus provides a quiescent plasma target, stable on timescales of minutes, for a whole host of active plasma experiments. High power RF experiments on ionospheric plasma conducted in the U.S. have been reported since 1970. The largest HF transmitter built to date is the HAARP phased-array HF transmitter near Gakona, Alaska which can deliver up to 3.6 Gigawatts (ERP) of CW RF power in the range of 2.8more » – 10 MHz to the ionosphere with microsecond pointing, power modulation, and frequency agility. With an ionospheric background thermal energy in the range of only 0.1 eV, this amount of power gives access to the highest regimes of the nonlinearity (RF intensity to thermal pressure) ratio. HAARP’s unique features have enabled the conduct of a number of unique nonlinear plasma experiments in the interaction region of overdense ionospheric plasma including generation of artificial aurorae, artificial ionization layers, VLF wave-particle interactions in the magnetosphere, parametric instabilities, stimulated electromagnetic emissions (SEE), strong Langmuir turbulence (SLT) and suprathermal electron acceleration. Diagnostics include the Modular UHF Ionospheric Radar (MUIR) sited at HAARP, the SuperDARN-Kodiak HF radar, spacecraft radio beacons, HF receivers to record stimulated electromagnetic emissions (SEE) and telescopes and cameras for optical emissions. We report on short timescale ponderomotive overshoot effects, artificial field-aligned irregularities (AFAI), the aspect angle dependence of the intensity of the HF-enhanced plasma line, and production of suprathermal electrons. One of the primary missions of HAARP, has been the generation of ELF (300 – 3000 Hz) and VLF (3 – 30 kHz) radio waves which are guided to global distances in the Earth

  19. China experiments with solar-thermal power production

    NASA Astrophysics Data System (ADS)

    Harris, Margaret

    2009-04-01

    Construction is due to start later this month on an experimental solar-thermal power plant in the shadow of China's Great Wall that will bring clean energy to 30 000 households by 2010. Built on the outskirts of Beijing at a cost of £10m, the 1.5MW Dahan plant will cover an area the size of 10 football pitches, and will serve as a platform for experiments on different solar-power technologies.

  20. Relaxation phenomena in AOT-water-decane critical and dense microemulsions

    NASA Astrophysics Data System (ADS)

    Letamendia, L.; Pru-Lestret, E.; Panizza, P.; Rouch, J.; Sciortino, F.; Tartaglia, P.; Hashimoto, C.; Ushiki, H.; Risso, D.

    2001-11-01

    We report on extensive measurements of the low and high frequencies sound velocity and sound absorption in AOT-water-decane microemulsions deduced from ultrasonic and, for the first time as far as the absorption is concerned, from Brillouin scattering experiments. New experimental results on dielectric relaxation are also reported. Our results, which include data taken for critical as well as dense microemulsions, show new interesting relaxation phenomena. The relaxation frequencies deduced from very high frequency acoustical measurements are in good agreement with new high frequency dielectric relaxation measurements. We show that along the critical isochore, sound dispersion, relaxation frequency, and static dielectric permittivity can be accurately fitted to power laws. The absolute values of the new exponents we derived from experimental data are nearly equal, and they are very close to β=0.33 characterising the shape of the coexistence curve. The exponent characterising the infinite frequency permittivity is very close to 0.04 relevant to the diverging shear viscosity. For dense microemulsions, two well defined relaxation domains have been identified and the temperature variations of the sound absorption and the zero frequency dielectric permittivity bear striking similarities. We also show that the relaxation frequency of the slow relaxation process is almost independent of temperature and volume fraction and so cannot be attributed to percolation phenomena, whereas it can more likely be attributed to an intrinsic relaxation process probably connected to membrane fluctuations.

  1. Critical and Griffiths-McCoy singularities in quantum Ising spin glasses on d-dimensional hypercubic lattices: A series expansion study.

    PubMed

    Singh, R R P; Young, A P

    2017-08-01

    We study the ±J transverse-field Ising spin-glass model at zero temperature on d-dimensional hypercubic lattices and in the Sherrington-Kirkpatrick (SK) model, by series expansions around the strong-field limit. In the SK model and in high dimensions our calculated critical properties are in excellent agreement with the exact mean-field results, surprisingly even down to dimension d=6, which is below the upper critical dimension of d=8. In contrast, at lower dimensions we find a rich singular behavior consisting of critical and Griffiths-McCoy singularities. The divergence of the equal-time structure factor allows us to locate the critical coupling where the correlation length diverges, implying the onset of a thermodynamic phase transition. We find that the spin-glass susceptibility as well as various power moments of the local susceptibility become singular in the paramagnetic phase before the critical point. Griffiths-McCoy singularities are very strong in two dimensions but decrease rapidly as the dimension increases. We present evidence that high enough powers of the local susceptibility may become singular at the pure-system critical point.

  2. Critical and Griffiths-McCoy singularities in quantum Ising spin glasses on d -dimensional hypercubic lattices: A series expansion study

    NASA Astrophysics Data System (ADS)

    Singh, R. R. P.; Young, A. P.

    2017-08-01

    We study the ±J transverse-field Ising spin-glass model at zero temperature on d -dimensional hypercubic lattices and in the Sherrington-Kirkpatrick (SK) model, by series expansions around the strong-field limit. In the SK model and in high dimensions our calculated critical properties are in excellent agreement with the exact mean-field results, surprisingly even down to dimension d =6 , which is below the upper critical dimension of d =8 . In contrast, at lower dimensions we find a rich singular behavior consisting of critical and Griffiths-McCoy singularities. The divergence of the equal-time structure factor allows us to locate the critical coupling where the correlation length diverges, implying the onset of a thermodynamic phase transition. We find that the spin-glass susceptibility as well as various power moments of the local susceptibility become singular in the paramagnetic phase before the critical point. Griffiths-McCoy singularities are very strong in two dimensions but decrease rapidly as the dimension increases. We present evidence that high enough powers of the local susceptibility may become singular at the pure-system critical point.

  3. Critical Leadership Pedagogy: Engaging Power, Identity, and Culture in Leadership Education for College Students of Color

    ERIC Educational Resources Information Center

    Pendakur, Vijay; Furr, Sara C.

    2016-01-01

    This chapter focuses on how the application of critical pedagogy to leadership education allows for issues of identity, power, and culture to shape the process of leadership learning. Examples from the authors' work with various populations of students of color are used to illustrate critical leadership pedagogy.

  4. Green Power Marketing Abroad: Recent Experience and Trends

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

    Bird, L.; Wustenhagen, R.; Aabakken, J.

    Green power marketing--the act of differentially selling electricity generated wholly or in part from renewable sources--has emerged in more than a dozen countries around the world. This report reviews green power marketing activity abroad to gain additional perspective on consumer demand and to discern key factors or policies that affect the development of green power markets. The objective is to draw lessons from experience in other countries that could be applicable to the U.S. market.

  5. Hybrid zero-voltage switching (ZVS) control for power inverters

    DOEpatents

    Amirahmadi, Ahmadreza; Hu, Haibing; Batarseh, Issa

    2016-11-01

    A power inverter combination includes a half-bridge power inverter including first and second semiconductor power switches receiving input power having an intermediate node therebetween providing an inductor current through an inductor. A controller includes input comparison circuitry receiving the inductor current having outputs coupled to first inputs of pulse width modulation (PWM) generation circuitry, and a predictive control block having an output coupled to second inputs of the PWM generation circuitry. The predictive control block is coupled to receive a measure of Vin and an output voltage at a grid connection point. A memory stores a current control algorithm configured for resetting a PWM period for a switching signal applied to control nodes of the first and second power switch whenever the inductor current reaches a predetermined upper limit or a predetermined lower limit.

  6. Calculations and experiments concerning lifting force and power in TEMPUS

    NASA Technical Reports Server (NTRS)

    Zong, J. H.; Szekely, J.; Lohofer, G.

    1993-01-01

    A critical comparison is reported between the theoretically predicted and experimentally measured values for the electromagnetic lifting force and the heating rates which may be achieved, under simulated microgravity conditions, using the TEMPUS electromagnetic levitation device. The experiments involved the suspending of a metallic sample from one arm of a recording balance, such that it was carefully positioned between the heating and the positioning coils of the levitation device. The net force exerted by the sample was measured as a function of position, the coil currents, and the nature of the sample. Some calculations are also reported regarding the power absorption by the sample. The theoretical predictions, based on the numerical solution of Maxwell's equations using the volume integral technique, were found to be in excellent agreement with the measurements. For the idealized case of a spherical sample, analytical solutions describing the lifting force were also found to agree very well with the computed results.

  7. A zero power harmonic transponder sensor for ubiquitous wireless μL liquid-volume monitoring

    NASA Astrophysics Data System (ADS)

    Huang, Haiyu; Chen, Pai-Yen; Hung, Cheng-Hsien; Gharpurey, Ranjit; Akinwande, Deji

    2016-01-01

    Autonomous liquid-volume monitoring is crucial in ubiquitous healthcare. However, conventional approach is based on either human visual observation or expensive detectors, which are costly for future pervasive monitoring. Here we introduce a novel approach based on passive harmonic transponder antenna sensor and frequency hopping spread spectrum (FHSS) pattern analysis, to provide a very low cost wireless μL-resolution liquid-volume monitoring without battery or digital circuits. In our conceptual demonstration, the harmonic transponder comprises of a passive nonlinear frequency multiplier connected to a metamaterial-inspired 3-D antenna designed to be highly sensitive to the liquid-volume within a confined region. The transponder first receives some FHSS signal from an interrogator, then converts such signal to its harmonic band and re-radiates through the antenna sensor. The harmonic signal is picked up by a sniffer receiver and decoded through pattern analysis of the high dimensional FHSS signal strength data. A robust, zero power, absolute accuracy wireless liquid-volume monitoring is realized in the presence of strong direct coupling, background scatters, distance variance as well as near-field human-body interference. The concepts of passive harmonic transponder sensor, metamaterial-inspired antenna sensor, and FHSS pattern analysis based sensor decoding may help establishing cost-effective, energy-efficient and intelligent wireless pervasive healthcare monitoring platforms.

  8. A zero power harmonic transponder sensor for ubiquitous wireless μL liquid-volume monitoring.

    PubMed

    Huang, Haiyu; Chen, Pai-Yen; Hung, Cheng-Hsien; Gharpurey, Ranjit; Akinwande, Deji

    2016-01-06

    Autonomous liquid-volume monitoring is crucial in ubiquitous healthcare. However, conventional approach is based on either human visual observation or expensive detectors, which are costly for future pervasive monitoring. Here we introduce a novel approach based on passive harmonic transponder antenna sensor and frequency hopping spread spectrum (FHSS) pattern analysis, to provide a very low cost wireless μL-resolution liquid-volume monitoring without battery or digital circuits. In our conceptual demonstration, the harmonic transponder comprises of a passive nonlinear frequency multiplier connected to a metamaterial-inspired 3-D antenna designed to be highly sensitive to the liquid-volume within a confined region. The transponder first receives some FHSS signal from an interrogator, then converts such signal to its harmonic band and re-radiates through the antenna sensor. The harmonic signal is picked up by a sniffer receiver and decoded through pattern analysis of the high dimensional FHSS signal strength data. A robust, zero power, absolute accuracy wireless liquid-volume monitoring is realized in the presence of strong direct coupling, background scatters, distance variance as well as near-field human-body interference. The concepts of passive harmonic transponder sensor, metamaterial-inspired antenna sensor, and FHSS pattern analysis based sensor decoding may help establishing cost-effective, energy-efficient and intelligent wireless pervasive healthcare monitoring platforms.

  9. Critical Concavity of a Drainage Basin for Steady-State

    NASA Astrophysics Data System (ADS)

    Byun, Jongmin; Paik, Kyungrock

    2015-04-01

    Longitudinal profiles of natural streams are known to show concave forms. Saying A as drainage area, channel gradient S can be expressed as the power-law, S≈A-θ (Flint, 1974), which is one of the scale-invariant features of drainage basin. According to literature, θ of most natural streams falls into a narrow range (0.4 < θ < 0.7) (Tucker and Whipple, 2002). It leads to fundamental questions: 'Why does θ falls into such narrow range?' and 'How is this related with other power-law scaling relationships reported in natural drainage basins?' To answer above questions, we analytically derive θ for a steady-state drainage basin following Lane's equilibrium (Lane, 1955) throughout the corridor and named this specific case as the 'critical concavity'. In the derivation, sediment transport capacity is estimated by unit stream power model (Yang, 1976), yielding a power function of upstream area. Stability of channel at a local point occurs when incoming flux equals outgoing flux at the point. Therefore, given the drainage at steady-state where all channel beds are stable, the exponent of the power function should be zero. From this, we can determine the critical concavity. Considering ranges of variables associated in this derivation, critical concavity cannot be resolved as a single definite value, rather a range of critical concavity is suggested. This range well agrees with the widely reported range of θ (0.4 < θ < 0.7) in natural streams. In this theoretical study, inter-relationships between power-laws such as hydraulic geometry (Leopold and Maddock, 1953), dominant discharge-drainage area (Knighton et al., 1999), and concavity, are coupled into the power-law framework of stream power sediment transport model. This allows us to explore close relationships between their power-law exponents: their relative roles and sensitivity. Detailed analysis and implications will be presented. References Flint, J. J., 1974, Stream gradient as a function of order, magnitude

  10. FOEHN: The critical experiment for the Franco-German High Flux Reactor

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

    Scharmer, K.; Eckert, H. G.

    1991-01-01

    A critical experiment for the Franco-German High Flux Reactor was carried out in the French reactor EOLE (CEN Cadarache). The purpose of the experiment was to check the calculation methods in a realistic geometry and to measure effects that can only be calculated imprecisely (e.g. beam hole effects). The structure of the experiment and the measurement and calculation methods are described. A detailed comparison between theoretical and experimental results was performed. 30 refs., 105 figs.

  11. Zero-G experimental validation of a robotics-based inertia identification algorithm

    NASA Astrophysics Data System (ADS)

    Bruggemann, Jeremy J.; Ferrel, Ivann; Martinez, Gerardo; Xie, Pu; Ma, Ou

    2010-04-01

    The need to efficiently identify the changing inertial properties of on-orbit spacecraft is becoming more critical as satellite on-orbit services, such as refueling and repairing, become increasingly aggressive and complex. This need stems from the fact that a spacecraft's control system relies on the knowledge of the spacecraft's inertia parameters. However, the inertia parameters may change during flight for reasons such as fuel usage, payload deployment or retrieval, and docking/capturing operations. New Mexico State University's Dynamics, Controls, and Robotics Research Group has proposed a robotics-based method of identifying unknown spacecraft inertia properties1. Previous methods require firing known thrusts then measuring the thrust, and the velocity and acceleration changes. The new method utilizes the concept of momentum conservation, while employing a robotic device powered by renewable energy to excite the state of the satellite. Thus, it requires no fuel usage or force and acceleration measurements. The method has been well studied in theory and demonstrated by simulation. However its experimental validation is challenging because a 6- degree-of-freedom motion in a zero-gravity condition is required. This paper presents an on-going effort to test the inertia identification method onboard the NASA zero-G aircraft. The design and capability of the test unit will be discussed in addition to the flight data. This paper also introduces the design and development of an airbearing based test used to partially validate the method, in addition to the approach used to obtain reference value for the test system's inertia parameters that can be used for comparison with the algorithm results.

  12. The Principle of Stasis: Why drift is not a Zero-Cause Law.

    PubMed

    Luque, Victor J

    2016-06-01

    This paper analyses the structure of evolutionary theory as a quasi-Newtonian theory and the need to establish a Zero-Cause Law. Several authors have postulated that the special character of drift is because it is the default behaviour or Zero-Cause Law of evolutionary systems, where change and not stasis is the normal state of them. For these authors, drift would be a Zero-Cause Law, the default behaviour and therefore a constituent assumption impossible to change without changing the system. I defend that drift's causal and explanatory power prevents it from being considered as a Zero-Cause Law. Instead, I propose that the default behaviour of evolutionary systems is what I call the Principle of Stasis, which posits that an evolutionary system where there is no selection, drift, mutation, migration, etc., and therefore no difference-maker, will not undergo any change (it will remain in stasis). Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Energy density engineering via zero-admittance domains in all-dielectric stratified materials

    DOE PAGES

    Amra, Claude; Zerrad, Myriam; Lemarchand, Fabien; ...

    2018-02-12

    Emerging photonic, sensing, and quantum applications require high fields and tight localization but low power consumption. Spatial, spectral, and magnitude control of electromagnetic fields is of key importance for enabling experiments in atomic, molecular, and optical physics. Here in this paper, we introduce the concept of zero-admittance domains as a mechanism for tailoring giant optical fields bound within or on the surface of dielectric media. The described mechanism permits the creation of highly localized fields of extreme amplitudes simultaneously for incident photons of multiple wavelengths and incidence angles but arbitrary polarization states. No material constraints are placed upon the boundingmore » media. Both intrinsic and extrinsic potential practical limitations of the predicted field enhancement are analyzed and applications relevant to optical sensors and microsources are briefly discussed.« less

  14. Energy density engineering via zero-admittance domains in all-dielectric stratified materials

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

    Amra, Claude; Zerrad, Myriam; Lemarchand, Fabien

    Emerging photonic, sensing, and quantum applications require high fields and tight localization but low power consumption. Spatial, spectral, and magnitude control of electromagnetic fields is of key importance for enabling experiments in atomic, molecular, and optical physics. Here in this paper, we introduce the concept of zero-admittance domains as a mechanism for tailoring giant optical fields bound within or on the surface of dielectric media. The described mechanism permits the creation of highly localized fields of extreme amplitudes simultaneously for incident photons of multiple wavelengths and incidence angles but arbitrary polarization states. No material constraints are placed upon the boundingmore » media. Both intrinsic and extrinsic potential practical limitations of the predicted field enhancement are analyzed and applications relevant to optical sensors and microsources are briefly discussed.« less

  15. Zero pressure gradient boundary layer at extreme Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Hultmark, Marcus; Vallikivi, Margit; Smits, Alexander

    2011-11-01

    Experiments were conducted in a zero pressure gradient flat plate boundary layer using the Princeton/ONR High Reynolds number Test Facility (HRTF). The HRTF uses highly compressed air, up to 220 atmospheres, to produce Reynolds numbers up to Reθ =225,000 . This corresponds to a δ+ =65,000 which is one of the highest Reynolds numbers ever measured in a laboratory. When using pressure to achieve high Reynolds numbers the size of the measurement probes become critical, thus the need for very small sensors is acute. The streamwise component of velocity was investigated using a nanoscale thermal anemometer (NSTAP) as well as a 200 μm pitot tube. The NSTAP has a spatial resolution as well as a temporal resolution one order of magnitude better than conventional measurement techniques. The data was compared to recent data from a high Reynolds number turbulent pipe flow and it was shown that the two flows are more similar than previous data suggests. Supported under NR Grant N00014-09-1-0263 (program manager Ron Joslin) and NSF Grant CBET-1064257(program manager Henning Winter).

  16. Do Zero-Cost Workers’ Compensation Medical Claims Really Have Zero Costs?

    PubMed Central

    Asfaw, Abay; Rosa, Roger; Mao, Rebecca

    2015-01-01

    Objective Previous research suggests that non–workers’ compensation (WC) insurance systems, such as group health insurance (GHI), Medicare, or Medicaid, at least partially cover work-related injury and illness costs. This study further examined GHI utilization and costs. Methods Using two-part model, we compared those outcomes immediately after injuries for which accepted WC medical claims made zero or positive medical payments. Results Controlling for pre-injury GHI utilization and costs and other covariates, our results indicated that post-injury GHI utilization and costs increased regardless of whether a WC medical claim was zero or positive. The increases were highest for zero-cost WC medical claims. Conclusion Our national estimates showed that zero-cost WC medical claims alone could cost the GHI $212 million per year. PMID:24316724

  17. Transductive multi-view zero-shot learning.

    PubMed

    Fu, Yanwei; Hospedales, Timothy M; Xiang, Tao; Gong, Shaogang

    2015-11-01

    Most existing zero-shot learning approaches exploit transfer learning via an intermediate semantic representation shared between an annotated auxiliary dataset and a target dataset with different classes and no annotation. A projection from a low-level feature space to the semantic representation space is learned from the auxiliary dataset and applied without adaptation to the target dataset. In this paper we identify two inherent limitations with these approaches. First, due to having disjoint and potentially unrelated classes, the projection functions learned from the auxiliary dataset/domain are biased when applied directly to the target dataset/domain. We call this problem the projection domain shift problem and propose a novel framework, transductive multi-view embedding, to solve it. The second limitation is the prototype sparsity problem which refers to the fact that for each target class, only a single prototype is available for zero-shot learning given a semantic representation. To overcome this problem, a novel heterogeneous multi-view hypergraph label propagation method is formulated for zero-shot learning in the transductive embedding space. It effectively exploits the complementary information offered by different semantic representations and takes advantage of the manifold structures of multiple representation spaces in a coherent manner. We demonstrate through extensive experiments that the proposed approach (1) rectifies the projection shift between the auxiliary and target domains, (2) exploits the complementarity of multiple semantic representations, (3) significantly outperforms existing methods for both zero-shot and N-shot recognition on three image and video benchmark datasets, and (4) enables novel cross-view annotation tasks.

  18. Changing the Culture of Academic Medicine: Critical Mass or Critical Actors?

    PubMed Central

    Newbill, Sharon L.; Cardinali, Gina; Morahan, Page S.; Chang, Shine; Magrane, Diane

    2017-01-01

    Abstract Purpose: By 2006, women constituted 34% of academic medical faculty, reaching a critical mass. Theoretically, with critical mass, culture and policy supportive of gender equity should be evident. We explore whether having a critical mass of women transforms institutional culture and organizational change. Methods: Career development program participants were interviewed to elucidate their experiences in academic health centers (AHCs). Focus group discussions were held with institutional leaders to explore their perceptions about contemporary challenges related to gender and leadership. Content analysis of both data sources revealed points of convergence. Findings were interpreted using the theory of critical mass. Results: Two nested domains emerged: the individual domain included the rewards and personal satisfaction of meaningful work, personal agency, tensions between cultural expectations of family and academic roles, and women's efforts to work for gender equity. The institutional domain depicted the sociocultural environment of AHCs that shaped women's experience, both personally and professionally, lack of institutional strategies to engage women in organizational initiatives, and the influence of one leader on women's ascent to leadership. Conclusions: The predominant evidence from this research demonstrates that the institutional barriers and sociocultural environment continue to be formidable obstacles confronting women, stalling the transformational effects expected from achieving a critical mass of women faculty. We conclude that the promise of critical mass as a turning point for women should be abandoned in favor of “critical actor” leaders, both women and men, who individually and collectively have the commitment and power to create gender-equitable cultures in AHCs. PMID:28092473

  19. Grace and compassion at "ground zero," New York City.

    PubMed

    Rogers, James R; Soyka, Karen M

    2004-01-01

    Responding to the request to write about our work at "ground zero" the site of the former World Trade Center in New York City following the September 11, 2001, terrorist attack has proved to be a challenging task. Challenging in that we have found it difficult to discuss and honor our experiences with mere words alone. Thus, this work has been "in progress" for a long period of time. Part of the challenge is reflected for us in the title of the article by the choice of the word "grace." That is, writing about grace at ground zero does not fit comfortably with our scientist-practitioner training. In searching for words to describe our experiences, however, we tried out a number of alternatives to "grace" including luck, chance, coincidence, and serendipity. None of these alternatives quite captured our experiences and our sense that certain events may best be conceptualized as unsolicited "gifts" that facilitated our work at the WTC site. So while the term "grace" may seem out of place in the scientific and professional literature, it fits well as a descriptor of some of our experiences as we continue our struggle to understand

  20. Non Fermi liquid properties of Ni-V close to the ferromagnetic quantum critical point

    NASA Astrophysics Data System (ADS)

    Schroeder, Almut; Ubaid-Kassis, Sara; Wyatt, Brendan; Vojta, Thomas

    2011-03-01

    Resistivity (ρ) and magnetization (M) data of the d-metal alloy Ni 1-x Vx are presented in the vicinity of the critical vanadium concentration xc ~ 11 % where the onset of long-range ferromagnetic (FM) order is suppressed to zero temperature. Above x c the temperature (T) dependence of the magnetic susceptibility is best described by simple nonuniversal power laws (e.g. M/H(T, H --> 0) ~ T α-1). Also the resistivity displays power laws (Δρ ~ T n) . Both exponents α (x) and n(x) vary with x displaying signatures of a disordered quantum phase transition in a metal very different than of a clean 3D FM. Supported by NSF (DMR-0306766, DMR-0339147, DMR-0906566) OBR-440653 and Research Corporation.

  1. Parahydrogen-enhanced zero-field nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Theis, T.; Ganssle, P.; Kervern, G.; Knappe, S.; Kitching, J.; Ledbetter, M. P.; Budker, D.; Pines, A.

    2011-07-01

    Nuclear magnetic resonance, conventionally detected in magnetic fields of several tesla, is a powerful analytical tool for the determination of molecular identity, structure and function. With the advent of prepolarization methods and detection schemes using atomic magnetometers or superconducting quantum interference devices, interest in NMR in fields comparable to the Earth's magnetic field and below (down to zero field) has been revived. Despite the use of superconducting quantum interference devices or atomic magnetometers, low-field NMR typically suffers from low sensitivity compared with conventional high-field NMR. Here we demonstrate direct detection of zero-field NMR signals generated through parahydrogen-induced polarization, enabling high-resolution NMR without the use of any magnets. The sensitivity is sufficient to observe spectra exhibiting 13C-1H scalar nuclear spin-spin couplings (known as J couplings) in compounds with 13C in natural abundance, without the need for signal averaging. The resulting spectra show distinct features that aid chemical fingerprinting.

  2. Atmospheric Convective Organization: Self-Organized Criticality or Homeostasis?

    NASA Astrophysics Data System (ADS)

    Yano, Jun-Ichi

    2015-04-01

    Atmospheric convection has a tendency organized on a hierarchy of scales ranging from the mesoscale to the planetary scales, with the latter especially manifested by the Madden-Julian oscillation. The present talk examines two major possible mechanisms of self-organization identified in wider literature from a phenomenological thermodynamic point of view by analysing a planetary-scale cloud-resolving model simulation. The first mechanism is self-organized criticality. A saturation tendency of precipitation rate with the increasing column-integrated water, reminiscence of critical phenomena, indicates self-organized criticality. The second is a self-regulation mechanism that is known as homeostasis in biology. A thermodynamic argument suggests that such self-regulation maintains the column-integrated water below a threshold by increasing the precipitation rate. Previous analyses of both observational data as well as cloud-resolving model (CRM) experiments give mixed results. A satellite data analysis suggests self-organized criticality. Some observational data as well as CRM experiments support homeostasis. Other analyses point to a combination of these two interpretations. In this study, a CRM experiment over a planetary-scale domain with a constant sea-surface temperature is analyzed. This analysis shows that the relation between the column-integrated total water and precipitation suggests self-organized criticality, whereas the one between the column-integrated water vapor and precipitation suggests homeostasis. The concurrent presence of these two mechanisms are further elaborated by detailed statistical and budget analyses. These statistics are scale invariant, reflecting a spatial scaling of precipitation processes. These self-organization mechanisms are most likely be best theoretically understood by the energy cycle of the convective systems consisting of the kinetic energy and the cloud-work function. The author has already investigated the behavior of this

  3. On the exploration of effect of critical beam power on the propagation of Gaussian laser beam in collisionless magnetized plasma

    NASA Astrophysics Data System (ADS)

    Urunkar, T. U.; Valkunde, A. T.; Vhanmore, B. D.; Gavade, K. M.; Patil, S. D.; Takale, M. V.

    2018-05-01

    It is quite known that critical power of the laser plays vital role in the propagation of Gaussian laser beam in collisionless plasma. The nonlinearity in dielectric constant considered herein is due to the ponderomotive force. In the present analysis, the interval of critical beam power has been explored to sustain the competition between diffraction and self-focusing of Gaussian laser beam during propagation in collisionless magnetized plasma. Differential equation for beam-width parameter has been established by using WKB and paraxial approximations under parabolic equation approach. The effect of critical power on the propagation of Gaussian laser beam has been presented graphically and discussed.

  4. Quantum criticality at the superconductor-insulator transition revealed by specific heat measurements

    PubMed Central

    Poran, S.; Nguyen-Duc, T.; Auerbach, A.; Dupuis, N.; Frydman, A.; Bourgeois, Olivier

    2017-01-01

    The superconductor–insulator transition (SIT) is considered an excellent example of a quantum phase transition that is driven by quantum fluctuations at zero temperature. The quantum critical point is characterized by a diverging correlation length and a vanishing energy scale. Low-energy fluctuations near quantum criticality may be experimentally detected by specific heat, cp, measurements. Here we use a unique highly sensitive experiment to measure cp of two-dimensional granular Pb films through the SIT. The specific heat shows the usual jump at the mean field superconducting transition temperature marking the onset of Cooper pairs formation. As the film thickness is tuned towards the SIT, is relatively unchanged, while the magnitude of the jump and low-temperature specific heat increase significantly. This behaviour is taken as the thermodynamic fingerprint of quantum criticality in the vicinity of a quantum phase transition. PMID:28224994

  5. Quantum criticality at the superconductor-insulator transition revealed by specific heat measurements.

    PubMed

    Poran, S; Nguyen-Duc, T; Auerbach, A; Dupuis, N; Frydman, A; Bourgeois, Olivier

    2017-02-22

    The superconductor-insulator transition (SIT) is considered an excellent example of a quantum phase transition that is driven by quantum fluctuations at zero temperature. The quantum critical point is characterized by a diverging correlation length and a vanishing energy scale. Low-energy fluctuations near quantum criticality may be experimentally detected by specific heat, c p , measurements. Here we use a unique highly sensitive experiment to measure c p of two-dimensional granular Pb films through the SIT. The specific heat shows the usual jump at the mean field superconducting transition temperature marking the onset of Cooper pairs formation. As the film thickness is tuned towards the SIT, is relatively unchanged, while the magnitude of the jump and low-temperature specific heat increase significantly. This behaviour is taken as the thermodynamic fingerprint of quantum criticality in the vicinity of a quantum phase transition.

  6. Processing of zero-derived words in English: an fMRI investigation.

    PubMed

    Pliatsikas, Christos; Wheeldon, Linda; Lahiri, Aditi; Hansen, Peter C

    2014-01-01

    Derivational morphological processes allow us to create new words (e.g. punish (V) to noun (N) punishment) from base forms. The number of steps from the basic units to derived words often varies (e.g., nationalitybridge-V) i.e., zero-derivation (Aronoff, 1980). We compared the processing of one-step (soakingexperiment. Participants were presented with derived forms of words (soaking, bridging) in a lexical decision task. Although the surface derived -ing forms can be contextually participles, gerunds, or even nouns, they are all derived from verbs since the suffix -ing can only be attached to verb roots. Crucially, the verb root is the basic form for the one-step words, whereas for the two-step words the verb root is zero derived from a basic noun. Significantly increased brain activity was observed for complex (one-step and two-step) versus simple (zero-step) forms in regions involved in morphological processing, such as the left inferior frontal gyrus (LIFG). Critically, activation was also more pronounced for two-step compared to one-step forms. Since both types of derived words have the same surface structure, our findings suggest that morphological processing is based on underlying morphological complexity, independent of overt

  7. Net Zero Water Update

    DTIC Science & Technology

    2011-05-12

    www.epa.gov/nrmrl/pubs/600r09048/600r09048.pdf • http://www.epa.gov/awi/res_rehabilitation.html Net Zero Waste • http://www.army.mil/-news/2011/02...24/52403-net- zero - waste -goal-becoming-a-reality- at-jblm/ • http://www.operationfree.net/2011/04/11/u-s-army-looks-to-net- zero - waste / 27

  8. Critical Experiences for Field Geologists: Emergent Themes in Interest Development

    ERIC Educational Resources Information Center

    LaDue, Nicole D.; Pacheco, Heather A.

    2013-01-01

    Geoscience education researchers are working to understand how we can most effectively increase our overall geoscience workforce capacity. The present study employed an inductive approach to explore the critical experiences that led to the persistence of successful field geologists in this STEM field. Interviews with 29 professional field…

  9. Criticality meets learning: Criticality signatures in a self-organizing recurrent neural network

    PubMed Central

    Del Papa, Bruno; Priesemann, Viola

    2017-01-01

    Many experiments have suggested that the brain operates close to a critical state, based on signatures of criticality such as power-law distributed neuronal avalanches. In neural network models, criticality is a dynamical state that maximizes information processing capacities, e.g. sensitivity to input, dynamical range and storage capacity, which makes it a favorable candidate state for brain function. Although models that self-organize towards a critical state have been proposed, the relation between criticality signatures and learning is still unclear. Here, we investigate signatures of criticality in a self-organizing recurrent neural network (SORN). Investigating criticality in the SORN is of particular interest because it has not been developed to show criticality. Instead, the SORN has been shown to exhibit spatio-temporal pattern learning through a combination of neural plasticity mechanisms and it reproduces a number of biological findings on neural variability and the statistics and fluctuations of synaptic efficacies. We show that, after a transient, the SORN spontaneously self-organizes into a dynamical state that shows criticality signatures comparable to those found in experiments. The plasticity mechanisms are necessary to attain that dynamical state, but not to maintain it. Furthermore, onset of external input transiently changes the slope of the avalanche distributions – matching recent experimental findings. Interestingly, the membrane noise level necessary for the occurrence of the criticality signatures reduces the model’s performance in simple learning tasks. Overall, our work shows that the biologically inspired plasticity and homeostasis mechanisms responsible for the SORN’s spatio-temporal learning abilities can give rise to criticality signatures in its activity when driven by random input, but these break down under the structured input of short repeating sequences. PMID:28552964

  10. Hydrogen-oxygen driven Zero Emissions bus drives around KSC Visitor Complex

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The Zero Emissions (ZE) transit bus tours the KSC Visitor Complex for a test ride. In the background are a mock-up orbiter named Explorer (left) and a stack of solid rocket boosters and external tank (right), typically used on Shuttle launches. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. The ZE bus is being used on tour routes at the KSC Visitor Complex for two days to introduce the public to the concept.

  11. Electric field measurements during the Condor critical velocity experiment

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.; Pfaff, R. F.; Haerendel, G.

    1986-01-01

    The instrumentation of the Condor critical velocity Ba experiment (Wescott et al., 1986) for the measurements of the energetic particles and the electric field associated with a Ba explosion is described. The Ba explosion created a complex electric field pulse detected in situ by a single-axis double electric-field probe on a separate spacecraft. The measurements provide evidence of several important links in the critical-velocity chain, and are consistent with two hypotheses. The first hypothesis involves the creation of large polarization electric field due to charge separation; the second hypothesis implies a polarization of the beam by currents flowing across it. The chain of physical processes inferred from the observations is in agreement with most theories for the Alfven process.

  12. SR90, strontium shaped-charge critical ionization velocity experiment

    NASA Technical Reports Server (NTRS)

    Wescott, Eugene M.; Stenbaek-Nielsen, Hans; Swift, Daniel W.; Valenzuela, Arnoldo; Rees, David

    1990-01-01

    In May 1986 an experiment was performed to test Alfven's critical ionization velocity (CIV) effect in free space, using the first high explosive shaped charge with a conical liner of strontium metal. The release, made at 540 km altitude at dawn twilight, was aimed at 48 deg to B. The background electron density was 1.5 x 10(exp 4) cu cm. A faint field-aligned Sr(+) ion streak with tip velocity of 2.6 km/s was observed from two optical sites. Using two calibration methods, it was calculated that between 4.5 x 10(exp 20) and 2 x 10(exp 21) ions were visible. An ionization time constant of 1920 s was calculated for Sr from the solar UV spectrum and ionization cross section which combined with a computer simulation of the injection predicts 1.7 x 10(exp 21) solar UV ions in the low-velocity part of the ion streak. Thus all the observed ions are from solar UV ionization of the slow (less than critical) velocity portion of the neutral jet. The observed neutral Sr velocity distribution and computer simulations indicate that 2 x 10(exp 21) solar UV ions would have been created from the fast (greater than critical) part of the jet. They would have been more diffuse, and were not observed. Using this fact it was estimated that any CIV ions created were less than 10(exp 21). It was concluded that future Sr CIV free space experiments should be conducted below the UV shadow height and in much larger background plasma density.

  13. Sudden death in paediatrics as a traumatic experience for critical care nurses.

    PubMed

    Lima, Lígia; Gonçalves, Sandra; Pinto, Cândida

    2018-01-01

    Research shows that nurses working in critical care units and in particular, paediatric units, are at risk of developing symptoms of secondary traumatic stress (STS). However, little attention has been given to this phenomenon when associated with situations of sudden death in paediatrics. This study aimed to examine the impact of sudden death in paediatrics on nurses working in paediatrics critical care units and to explore nurses' experiences of this event. This study used a mixed-methods design. The Impact of Event Scale - Revised was used for investigating the presence of STS symptoms. In addition, an interview was conducted with six nurses. Fifty-seven percent of nurses responded to the surveys and six nurses were interviewed. The results showed that the sudden death of children and adolescents is an event that elicits symptoms of STS in nurses. The quantitative assessment, revealed that 19·4% presented total scores indicating high impact. The participants interviewed described experiences of subjective distress, such as intrusive thoughts, avoidance and hyperarousal. Other factors were also reported as influencing the experience of the sudden death of a child/adolescent, namely, the child's age, the cause of death and the family's reaction to the loss. According to the participants, the emotional impact was also determined by parenthood, previous training and professional experience. Sudden death in paediatric critical care units is one of the most difficult situations in nursing practice and elicits STS symptoms, which may severely impact the physical and psychological health of nurses and ultimately affect the quality of the provided care. This study emphasizes the need for promoting better conditions for professional practice, namely, with regard to emotional support, as well as training programmes for skills development in the area of management of traumatic situations and of communication with clients. © 2017 British Association of Critical Care

  14. New approaches to provide ride-through for critical loads in electric power distribution systems

    NASA Astrophysics Data System (ADS)

    Montero-Hernandez, Oscar C.

    2001-07-01

    The extensive use of electronic circuits has enabled modernization, automation, miniaturization, high quality, low cost, and other achievements regarding electric loads in the last decades. However, modern electronic circuits and systems are extremely sensitive to disturbances from the electric power supply. In fact, the rate at which these disturbances happen is considerable as has been documented in recent years. In response to the power quality concerns presented previously, this dissertation is proposing new approaches to provide ride-through for critical loads during voltage disturbances with emphasis on voltage sags. In this dissertation, a new approach based on an AC-DC-AC system is proposed to provide ride-through for critical loads connected in buildings and/or an industrial system. In this approach, a three-phase IGBT inverter with a built in Dc-link voltage regulator is suitably controlled along with static by-pass switches to provide continuous power to critical loads. During a disturbance, the input utility source is disconnected and the power from the inverter is connected to the load. The remaining voltage in the AC supply is converted to DC and compensated before being applied to the inverter and the load. After detecting normal utility conditions, power from the utility is restored to the critical load. In order to achieve an extended ride-through capability a second approach is introduced. In this case, the Dc-link voltage regulator is performed by a DC-DC Buck-Boost converter. This new approach has the capability to mitigate voltage variations below and above the nominal value. In the third approach presented in this dissertation, a three-phase AC to AC boost converter is investigated. This converter provides a boosting action for the utility input voltages, right before they are applied to the load. The proposed Pulse Width Modulation (PWM) control strategy ensures independent control of each phase and compensates for both single-phase or poly

  15. Zero-Based Budgeting.

    ERIC Educational Resources Information Center

    Wichowski, Chester

    1979-01-01

    The zero-based budgeting approach is designed to achieve the greatest benefit with the fewest undesirable consequences. Seven basic steps make up the zero-based decision-making process: (1) identifying program goals, (2) classifying goals, (3) identifying resources, (4) reviewing consequences, (5) developing decision packages, (6) implementing a…

  16. Analysis of benchmark critical experiments with ENDF/B-VI data sets

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

    Hardy, J. Jr.; Kahler, A.C.

    1991-12-31

    Several clean critical experiments were analyzed with ENDF/B-VI data to assess the adequacy of the data for U{sup 235}, U{sup 238} and oxygen. These experiments were (1) a set of homogeneous U{sup 235}-H{sub 2}O assemblies spanning a wide range of hydrogen/uranium ratio, and (2) TRX-1, a simple, H{sub 2}O-moderated Bettis lattice of slightly-enriched uranium metal rods. The analyses used the Monte Carlo program RCP01, with explicit three-dimensional geometry and detailed representation of cross sections. For the homogeneous criticals, calculated k{sub crit} values for large, thermal assemblies show good agreement with experiment. This supports the evaluated thermal criticality parameters for U{supmore » 235}. However, for assemblies with smaller H/U ratios, k{sub crit} values increase significantly with increasing leakage and flux-spectrum hardness. These trends suggest that leakage is underpredicted and that the resonance eta of the ENDF/B-VI U{sup 235} is too large. For TRX-1, reasonably good agreement is found with measured lattice parameters (reaction-rate ratios). Of primary interest is rho28, the ratio of above-thermal to thermal U{sup 238} capture. Calculated rho28 is 2.3 ({+-} 1.7) % above measurement, suggesting that U{sup 238} resonance capture remains slightly overpredicted with ENDF/B-VI. However, agreement is better than observed with earlier versions of ENDF/B.« less

  17. Navigating Critical Theory and Postmodernism: Social Justice and Therapist Power in Family Therapy.

    PubMed

    D'Arrigo-Patrick, Justine; Hoff, Chris; Knudson-Martin, Carmen; Tuttle, Amy

    2017-09-01

    The family therapy field encourages commitment to diversity and social justice, but offers varying ideas about how to attentively consider these issues. Critical informed models advocate activism, whereas postmodern informed models encourage multiple perspectives. It is often not clear how activism and an emphasis on multiple perspectives connect, engendering the sense that critical and postmodern practices may be disparate. To understand how therapists negotiate these perspectives in practice, this qualitative grounded theory analysis drew on interviews with 11 therapists, each known for their work from both critical and postmodern perspectives. We found that these therapists generally engage in a set of shared constructionist practices while also demonstrating two distinct forms of activism: activism through countering and activism through collaborating. Ultimately, decisions made about how to navigate critical and postmodern influences were connected to how therapists viewed ethics and the ways they were comfortable using their therapeutic power. The findings illustrate practice strategies through which therapists apply each approach. © 2016 Family Process Institute.

  18. 3D Printing in Zero-G Experiment, In Space Manufacturing (LPS, 4)

    NASA Technical Reports Server (NTRS)

    Bean, Quincy; Cooper, Ken; Werkheiser, Niki

    2015-01-01

    The 3D Printing in Zero-G Experiment has been an ongoing effort for several years. In June 2014 the technology demonstration 3D printer was launched to the International Space Station. In November 2014 the first 21 parts were manufactured in orbit marking the beginning of a paradigm shift that will allow astronauts to be more self-sufficient and pave the way to larger scale orbital manufacturing. Prior to launch the 21 parts were built on the ground with the flight unit with the same feedstock. These ground control samples are to be tested alongside the flight samples in order to determine if there is a measurable difference between parts built on the ground vs. parts built in space. As of this writing, testing has not yet commenced. Tests to be performed are structured light scanning for volume and geometric discrepancies, CT scanning for density measurement, destructive testing of mechanical samples, and SEM analysis for inter-laminar adhesion discrepancies. Additionally, an ABS material characterization was performed on mechanical samples built from the same CAD files as the flight and ground samples on different machine / feedstock combinations. The purpose of this testing was twofold: first to obtain mechanical data in order to have a baseline comparison for the flight and ground samples and second to ascertain if there is a measurable difference between machines and feedstock.

  19. A zero power harmonic transponder sensor for ubiquitous wireless μL liquid-volume monitoring

    PubMed Central

    Huang, Haiyu; Chen, Pai-Yen; Hung, Cheng-Hsien; Gharpurey, Ranjit; Akinwande, Deji

    2016-01-01

    Autonomous liquid-volume monitoring is crucial in ubiquitous healthcare. However, conventional approach is based on either human visual observation or expensive detectors, which are costly for future pervasive monitoring. Here we introduce a novel approach based on passive harmonic transponder antenna sensor and frequency hopping spread spectrum (FHSS) pattern analysis, to provide a very low cost wireless μL-resolution liquid-volume monitoring without battery or digital circuits. In our conceptual demonstration, the harmonic transponder comprises of a passive nonlinear frequency multiplier connected to a metamaterial-inspired 3-D antenna designed to be highly sensitive to the liquid-volume within a confined region. The transponder first receives some FHSS signal from an interrogator, then converts such signal to its harmonic band and re-radiates through the antenna sensor. The harmonic signal is picked up by a sniffer receiver and decoded through pattern analysis of the high dimensional FHSS signal strength data. A robust, zero power, absolute accuracy wireless liquid-volume monitoring is realized in the presence of strong direct coupling, background scatters, distance variance as well as near-field human-body interference. The concepts of passive harmonic transponder sensor, metamaterial-inspired antenna sensor, and FHSS pattern analysis based sensor decoding may help establishing cost-effective, energy-efficient and intelligent wireless pervasive healthcare monitoring platforms. PMID:26732251

  20. Zero ischemia robotic-assisted partial nephrectomy in Alberta: Initial results of a novel approach.

    PubMed

    Forbes, Ellen; Cheung, Douglas; Kinnaird, Adam; Martin, Blair St

    2015-01-01

    Partial nephrectomy remains the standard of care in early stage, organ-confined renal tumours. Recent evidence suggests that minimally invasive surgery can proceed without segmental vessel clamping. In this study, we review our experience at a Canadian centre with zero ischemia robotic-assisted partial nephrectomy (RAPN). A retrospective chart review of zero ischemia RAPN was performed. All surgeries were consecutive partial nephrectomies performed by the same surgeon at a tertiary care centre in Northern Alberta. The mean follow-up period was 28 months. These outcomes were compared against the current standards for zero ischemia (as outlined by the University of Southern California Institute of Urology [USC]). We included 21 patients who underwent zero ischemia RAPN between January 2012 and June 2013. Baseline data were similar to contemporary studies. Twelve (57.1%) required no vascular clamping, 7 (33.3%) required clamping of a single segmental artery, and 2 (9.5%) required clamping of two segmental arteries. We achieved an average estimated blood loss of 158 cc, with a 9.2% average increase in creatinine postoperatively. Operating time and duration of hospital stay were short at 153 minutes and 2.2 days, respectively. Zero ischemia partial nephrectomy was a viable option at our institution with favourable results in terms of intra-operative blood loss and postoperative creatinine change compared to results from contemporary standard zero ischemia studies (USC). To our knowledge, this is the first study to review an initial experience with the zero ischemia protocol in robotic-assisted partial nephrectomies at a Canadian hospital.

  1. The Power of Work Experiences: Characteristics Critical to Developing Expertise in Strategic Thinking

    ERIC Educational Resources Information Center

    Goldman, Ellen F.

    2008-01-01

    The ability to think strategically is an increasingly important requirement for managers at all organizational levels. HRD (human resource development) professionals have attempted to help develop this ability through work experiences. However, research identifying which work experiences are most beneficial is limited. As a result, HRD efforts may…

  2. Zero-truncated negative binomial - Erlang distribution

    NASA Astrophysics Data System (ADS)

    Bodhisuwan, Winai; Pudprommarat, Chookait; Bodhisuwan, Rujira; Saothayanun, Luckhana

    2017-11-01

    The zero-truncated negative binomial-Erlang distribution is introduced. It is developed from negative binomial-Erlang distribution. In this work, the probability mass function is derived and some properties are included. The parameters of the zero-truncated negative binomial-Erlang distribution are estimated by using the maximum likelihood estimation. Finally, the proposed distribution is applied to real data, the number of methamphetamine in the Bangkok, Thailand. Based on the results, it shows that the zero-truncated negative binomial-Erlang distribution provided a better fit than the zero-truncated Poisson, zero-truncated negative binomial, zero-truncated generalized negative-binomial and zero-truncated Poisson-Lindley distributions for this data.

  3. The Impact of Load Carriage on Measures of Power and Agility in Tactical Occupations: A Critical Review.

    PubMed

    Joseph, Aaron; Wiley, Amy; Orr, Robin; Schram, Benjamin; Dawes, J Jay

    2018-01-07

    The current literature suggests that load carriage can impact on a tactical officer's mobility, and that survival in the field may rely on the officer's mobility. The ability for humans to generate power and agility is critical for performance of the high-intensity movements required in the field of duty. The aims of this review were to critically examine the literature investigating the impacts of load carriage on measures of power and agility and to synthesize the findings. The authors completed a search of the literature using key search terms in four databases. After relevant studies were located using strict inclusion and exclusion criteria, the studies were critically appraised using the Downs and Black Checklist and relevant data were extracted and tabled. Fourteen studies were deemed relevant for this review, ranging in percentage quality scores from 42.85% to 71.43%. Outcome measures used in these studies to indicate levels of power and agility included short-distance sprints, vertical jumps, and agility runs, among others. Performance of both power and agility was shown to decrease when tactical load was added to the participants. This suggests that the increase in weight carried by tactical officers may put this population at risk of injury or fatality in the line of duty.

  4. The Impact of Load Carriage on Measures of Power and Agility in Tactical Occupations: A Critical Review

    PubMed Central

    Joseph, Aaron; Wiley, Amy; Dawes, J. Jay

    2018-01-01

    The current literature suggests that load carriage can impact on a tactical officer’s mobility, and that survival in the field may rely on the officer’s mobility. The ability for humans to generate power and agility is critical for performance of the high-intensity movements required in the field of duty. The aims of this review were to critically examine the literature investigating the impacts of load carriage on measures of power and agility and to synthesize the findings. The authors completed a search of the literature using key search terms in four databases. After relevant studies were located using strict inclusion and exclusion criteria, the studies were critically appraised using the Downs and Black Checklist and relevant data were extracted and tabled. Fourteen studies were deemed relevant for this review, ranging in percentage quality scores from 42.85% to 71.43%. Outcome measures used in these studies to indicate levels of power and agility included short-distance sprints, vertical jumps, and agility runs, among others. Performance of both power and agility was shown to decrease when tactical load was added to the participants. This suggests that the increase in weight carried by tactical officers may put this population at risk of injury or fatality in the line of duty. PMID:29316674

  5. Scripting "Safe" Schools: Mapping Urban Education and Zero Tolerance during the Long War

    ERIC Educational Resources Information Center

    Nguyen, Nicole

    2013-01-01

    Taking a cue from U.S. military operations, surveillance cameras, police officers, metal detectors, hall sweeps, expulsion, zero tolerance policing, and biometrics contour young people's everyday life in public schools. Given this influx in policing and surveillance in schools, recent critical scholarship broadly attends to the increase in and…

  6. Development of modular scalable pulsed power systems for high power magnetized plasma experiments

    NASA Astrophysics Data System (ADS)

    Bean, I. A.; Weber, T. E.; Adams, C. S.; Henderson, B. R.; Klim, A. J.

    2017-10-01

    New pulsed power switches and trigger drivers are being developed in order to explore higher energy regimes in the Magnetic Shock Experiment (MSX) at Los Alamos National Laboratory. To achieve the required plasma velocities, high-power (approx. 100 kV, 100s of kA), high charge transfer (approx. 1 C), low-jitter (few ns) gas switches are needed. A study has been conducted on the effects of various electrode geometries and materials, dielectric media, and triggering strategies; resulting in the design of a low-inductance annular field-distortion switch, optimized for use with dry air at 90 psig, and triggered by a low-jitter, rapid rise-time solid-state Linear Transformer Driver. The switch geometry and electrical characteristics are designed to be compatible with Syllac style capacitors, and are intended to be deployed in modular configurations. The scalable nature of this approach will enable the rapid design and implementation of a wide variety of high-power magnetized plasma experiments. This work is supported by the U.S. Department of Energy, National Nuclear Security Administration. Approved for unlimited release, LA-UR-17-2578.

  7. Majorana zero modes in Dirac semimetal Josephson junctions

    NASA Astrophysics Data System (ADS)

    Li, Chuan; de Boer, Jorrit; de Ronde, Bob; Huang, Yingkai; Golden, Mark; Brinkman, Alexander

    We have realized proximity-induced superconductivity in a Dirac semimetal and revealed the topological nature of the superconductivity by the observation of Majorana zero modes. As a Dirac semimetal, Bi0.97Sb0.03 is used, where a three-dimensional Dirac cone exists in the bulk due to an accidental touching between conduction and valence bands. Electronic transport measurements on Hall-bars fabricated out of Bi0.97Sb0.03 flakes consistently show negative magnetoresistance for magnetic fields parallel to the current, which is associated with the chiral anomaly. In perpendicular magnetic fields, we see Shubnikov-de Haas oscillations that indicate very low carrier densities. The low Fermi energy and protection against backscattering in our Dirac semimetal Josephson junctions provide favorable conditions for a large contribution of Majorana zero modes to the supercurrent. In radiofrequency irradiation experiments, we indeed observe these Majorana zero modes in Nb-Bi0.97Sb0.03-Nb Josephson junctions as a 4 π periodic contribution to the current-phase relation.

  8. Zero refractive index in time-Floquet acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Koutserimpas, Theodoros T.; Fleury, Romain

    2018-03-01

    New scientific investigations of artificially structured materials and experiments have exhibited wave manipulation to the extreme. In particular, zero refractive index metamaterials have been on the front line of wave physics research for their unique wave manipulation properties and application potentials. Remarkably, in such exotic materials, time-harmonic fields have an infinite wavelength and do not exhibit any spatial variations in their phase distribution. This unique feature can be achieved by forcing a Dirac cone to the center of the Brillouin zone ( Γ point), as previously predicted and experimentally demonstrated in time-invariant metamaterials by means of accidental degeneracy between three different modes. In this article, we propose a different approach that enables true conical dispersion at Γ with twofold degeneracy and generates zero index properties. We break time-reversal symmetry and exploit a time-Floquet modulation scheme to demonstrate a time-Floquet acoustic metamaterial with zero refractive index. This behavior, predicted using stroboscopic analysis, is confirmed by full-wave finite element simulations. Our results establish the relevance of time-Floquet metamaterials as a novel reconfigurable platform for wave control.

  9. A Three-dimensional Polymer Scaffolding Material Exhibiting a Zero Poisson's Ratio.

    PubMed

    Soman, Pranav; Fozdar, David Y; Lee, Jin Woo; Phadke, Ameya; Varghese, Shyni; Chen, Shaochen

    2012-05-14

    Poisson's ratio describes the degree to which a material contracts (expands) transversally when axially strained. A material with a zero Poisson's ratio does not transversally deform in response to an axial strain (stretching). In tissue engineering applications, scaffolding having a zero Poisson's ratio (ZPR) may be more suitable for emulating the behavior of native tissues and accommodating and transmitting forces to the host tissue site during wound healing (or tissue regrowth). For example, scaffolding with a zero Poisson's ratio may be beneficial in the engineering of cartilage, ligament, corneal, and brain tissues, which are known to possess Poisson's ratios of nearly zero. Here, we report a 3D biomaterial constructed from polyethylene glycol (PEG) exhibiting in-plane Poisson's ratios of zero for large values of axial strain. We use digital micro-mirror device projection printing (DMD-PP) to create single- and double-layer scaffolds composed of semi re-entrant pores whose arrangement and deformation mechanisms contribute the zero Poisson's ratio. Strain experiments prove the zero Poisson's behavior of the scaffolds and that the addition of layers does not change the Poisson's ratio. Human mesenchymal stem cells (hMSCs) cultured on biomaterials with zero Poisson's ratio demonstrate the feasibility of utilizing these novel materials for biological applications which require little to no transverse deformations resulting from axial strains. Techniques used in this work allow Poisson's ratio to be both scale-independent and independent of the choice of strut material for strains in the elastic regime, and therefore ZPR behavior can be imparted to a variety of photocurable biomaterial.

  10. Receiving power through confirmation: the meaning of close relatives for people who have been critically ill.

    PubMed

    Engström, Asa; Söderberg, Siv

    2007-09-01

    This paper is a report of a study to elucidate the meaning of close relatives for people who have been critically ill and received care in an intensive care unit. Falling critically ill can bring about a difficult change in life. In previous reports such events are described as frightening experiences, and close relatives are described as an important source of support in this difficult situation. A purposive sample of 10 adults, eight men and two women, narrated how they experienced their close relatives during and after the time they were critically ill. The data were collected in 2004. The interview texts were transcribed and interpreted using a phenomenological hermeneutic approach influenced by the philosophy of Ricoeur. One major theme was identified, experiencing confirmation, with six sub-themes: receiving explanations; a feeling of being understood; a feeling of safety; gaining strength and will-power; having possibilities and realizing their value. Close relatives served as tools for the person who was ill, facilitating better communication and an increased ability to do various things. Simultaneously, feelings of dependence on the close relatives were expressed. There were descriptions of loneliness and fear in the absence of close relatives and, in order to feel safe, the participants wanted their close relatives to stay near them. Close relatives are vital, as they are the ill person's motivation to stay alive and to continue the struggle. Their presence is of great importance for the ill person and must be facilitated by staff.

  11. The International Heat Pipe Experiment. [international cooperation zero g experiment

    NASA Technical Reports Server (NTRS)

    Mcintosh, R.; Ollendorf, S.; Harwell, W.

    1976-01-01

    The aims of the experiment are outlined. Flight experiments included in this program were provided by NASA, Goddard Space Flight Center, ESA (European Space Agency), the German Ministry of Technology, Hughes Aircraft Company and NASA, Ames Research Center.

  12. Lived experience in teaching mental health nursing: issues of fear and power.

    PubMed

    Happell, Brenda; Bennetts, Wanda; Harris, Scott; Platania-Phung, Chris; Tohotoa, Jenny; Byrne, Louise; Wynaden, Dianne

    2015-02-01

    Australian mental health policy clearly articulates recovery focus as the underpinning of mental health services. Barriers to achieving a recovery focus are identified in the literature, with negative attitudes of health professionals receiving particular attention. The involvement of people with lived experience of significant mental health challenges and mental health service use is essential to enhancing more positive attitudes. Lived-experience involvement in the education of nurses is evident; however, it is generally limited and implemented on an ad hoc basis. Overall, there is a paucity of literature on this topic. A qualitative exploratory study was undertaken to elicit the views and perceptions of nurse academics and lived-experience educators about the inclusion of lived experience in mental health nursing education. One major theme to emerge from the research was issues of fear and power, which included three subthemes: facing fear, demystifying mental illness, and issues of power. Lived-experience involvement has an important role to play in the education of nurses in addressing fear and demystifying the experience of mental illness. The power that lived-experience educators exercised in their roles varied considerably, and for many, was limited. Therefore, the effectiveness of lived-experience involvement requires a more equitable distribution of power. © 2014 Australian College of Mental Health Nurses Inc.

  13. The Zero Program

    ERIC Educational Resources Information Center

    Roland, Erling; Midthassel, Unni Vere

    2012-01-01

    Zero is a schoolwide antibullying program developed by the Centre for Behavioural Research at the University of Stavanger, Norway. It is based on three main principles: a zero vision of bullying, collective commitment among all employees at the school using the program, and continuing work. Based on these principles, the program aims to reduce…

  14. Critical Seismic Vector Random Excitations for Multiply Supported Structures

    NASA Astrophysics Data System (ADS)

    Sarkar, A.; Manohar, C. S.

    1998-05-01

    A method for determining critical power spectral density matrix models for earthquake excitations which maximize steady response variance of linear multiply supported extended structures and which also satisfy constraints on input variance, zero crossing rates, frequency content and transmission time lag has been developed. The optimization problem is shown to be non-linear in nature and solutions are obtained by using an iterative technique which is based on linear programming method. A constraint on entropy rate as a measure of uncertainty which can be expected in realistic earthquake ground motions is proposed which makes the critical excitations more realistic. Two special cases are also considered. Firstly, when knowledge of autospectral densities is available, the critical response is shown to be produced by fully coherent excitations which are neither in-phase nor out-of-phase. The critical phase between the excitation components depends on structural parameters, but independent of the auto-spectral densities of the excitations. Secondly, when the knowledge of autospectral densities and phase spectrum of the excitations is available, the critical response is shown to be produced by a system dependent coherence function representing neither fully coherent nor fully incoherent ground motions. The applications of these special cases are discussed in the context of land-based extended structures and secondary systems such as nuclear piping assembly. Illustrative examples on critical inputs and response of sdof and a long-span suspended cable which demonstrated the various features of the approach developed are presented.

  15. Experimental phase diagram of zero-bias conductance peaks in superconductor/semiconductor nanowire devices

    PubMed Central

    Chen, Jun; Yu, Peng; Stenger, John; Hocevar, Moïra; Car, Diana; Plissard, Sébastien R.; Bakkers, Erik P. A. M.; Stanescu, Tudor D.; Frolov, Sergey M.

    2017-01-01

    Topological superconductivity is an exotic state of matter characterized by spinless p-wave Cooper pairing of electrons and by Majorana zero modes at the edges. The first signature of topological superconductivity is a robust zero-bias peak in tunneling conductance. We perform tunneling experiments on semiconductor nanowires (InSb) coupled to superconductors (NbTiN) and establish the zero-bias peak phase in the space of gate voltage and external magnetic field. Our findings are consistent with calculations for a finite-length topological nanowire and provide means for Majorana manipulation as required for braiding and topological quantum bits. PMID:28913432

  16. Intermittency and dynamical Lee-Yang zeros of open quantum systems.

    PubMed

    Hickey, James M; Flindt, Christian; Garrahan, Juan P

    2014-12-01

    We use high-order cumulants to investigate the Lee-Yang zeros of generating functions of dynamical observables in open quantum systems. At long times the generating functions take on a large-deviation form with singularities of the associated cumulant generating functions-or dynamical free energies-signifying phase transitions in the ensemble of dynamical trajectories. We consider a driven three-level system as well as the dissipative Ising model. Both systems exhibit dynamical intermittency in the statistics of quantum jumps. From the short-time behavior of the dynamical Lee-Yang zeros, we identify critical values of the counting field which we attribute to the observed intermittency and dynamical phase coexistence. Furthermore, for the dissipative Ising model we construct a trajectory phase diagram and estimate the value of the transverse field where the stationary state changes from being ferromagnetic (inactive) to paramagnetic (active).

  17. Couette-Poiseuille flow experiment with zero mean advection velocity: Subcritical transition to turbulence

    NASA Astrophysics Data System (ADS)

    Klotz, L.; Lemoult, G.; Frontczak, I.; Tuckerman, L. S.; Wesfreid, J. E.

    2017-04-01

    We present an experimental setup that creates a shear flow with zero mean advection velocity achieved by counterbalancing the nonzero streamwise pressure gradient by moving boundaries, which generates plane Couette-Poiseuille flow. We obtain experimental results in the transitional regime for this flow. Using flow visualization, we characterize the subcritical transition to turbulence in Couette-Poiseuille flow and show the existence of turbulent spots generated by a permanent perturbation. Due to the zero mean advection velocity of the base profile, these turbulent structures are nearly stationary. We distinguish two regions of the turbulent spot: the active turbulent core, which is characterized by waviness of the streaks similar to traveling waves, and the surrounding region, which includes in addition the weak undisturbed streaks and oblique waves at the laminar-turbulent interface. We also study the dependence of the size of these two regions on Reynolds number. Finally, we show that the traveling waves move in the downstream (Poiseuille) direction.

  18. Pressure-tuned quantum criticality in the antiferromagnetic Kondo semimetal CeNi 2–δAs 2

    DOE PAGES

    Luo, Yongkang; Ronning, F.; Wakeham, N.; ...

    2015-10-19

    The easily tuned balance among competing interactions in Kondo-lattice metals allows access to a zero-temperature, continuous transition between magnetically ordered and disordered phases, a quantum-critical point (QCP). Indeed, these highly correlated electron materials are prototypes for discovering and exploring quantum-critical states. Theoretical models proposed to account for the strange thermodynamic and electrical transport properties that emerge around the QCP of a Kondo lattice assume the presence of an indefinitely large number of itinerant charge carriers. Here, we report a systematic transport and thermodynamic investigation of the Kondo-lattice system CeNi 2–δAs 2 (δ ≈ 0.28) as its antiferromagnetic order is tunedmore » by pressure and magnetic field to zero-temperature boundaries. These experiments show that the very small but finite carrier density of ~0.032 e –/formular unit in CeNi 2–δAs 2 leads to unexpected transport signatures of quantum criticality and the delayed development of a fully coherent Kondo-lattice state with decreasing temperature. Here, the small carrier density and associated semimetallicity of this Kondo-lattice material favor an unconventional, local-moment type of quantum criticality and raises the specter of the Nozières exhaustion idea that an insufficient number of conduction-electron spins to separately screen local moments requires collective Kondo screening.« less

  19. Patient Experience: A Critical Indicator of Healthcare Performance.

    PubMed

    Guler, Pamela H

    2017-01-01

    Patient experience has become a critical differentiator for healthcare organizations, and it will only grow in importance as transparency and consumerism dominate the healthcare landscape. Creating and sustaining a consistently exceptional experience that promotes patient engagement and the best outcomes is far more than just "satisfying" patients, going well beyond amenities that may be provided.Perception of care experience is often shaped by methods we use to address the biopsychosocial needs of patients. Building relationships and communicating well with our patients and families are primary approaches. In a complex healthcare situation, patients may not fully understand or remember the highly clinical nature of treatment. However, they always remember how we made them feel, how we communicated with them as a team, and what interactions they experienced while in our care.Patients who are fully informed and feel connected to their caregivers are often less anxious than those who are disengaged. Informed and engaged patients are enabled to participate in their healthcare. Organizations that focus on developing an accountable culture-one that inspires caregivers to communicate in a way that connects to patients' mind, body, and spirit while leveraging standard, evidence-based patient experience practices-find that patients' perception of care, or "the patient experience," is vastly improved.Adventist Health System has embarked on a journey to patient experience excellence with a commitment to whole-person care and standard patient experience practice across the system. Recognized with several national awards, we continue to strengthen our approach toward bringing all of our campuses and patient settings to sustained high-level performance. We have found that a combination of strong, accountable leadership; a focus on employee culture; engagement of physicians; standardized patient experience practices and education; and meaningful use of patient feedback are top

  20. Methods of preparation and modification of advanced zero-valent iron nanoparticles, their properties and application in water treatment technologies

    NASA Astrophysics Data System (ADS)

    Filip, Jan; Kašlík, Josef; Medřík, Ivo; Petala, Eleni; Zbořil, Radek; Slunský, Jan; Černík, Miroslav; Stavělová, Monika

    2014-05-01

    Zero-valent iron nanoparticles are commonly used in modern water treatment technologies. Compared to conventionally-used macroscopic iron or iron microparticles, the using of nanoparticles has the advantages given mainly by their generally large specific surface area (it drives their high reactivity and/or sorption capacity), small dimensions (it allows their migration e.g. in ground water), and particular physical and chemical properties. Following the applications of zero-valent iron particles in various pilot tests, there arose several critical suggestions for improvements of used nanomaterials and for development of new generation of reactive nanomaterials. In the presentation, the methods of zero-valent iron nanoparticles synthesis will be summarized with a special attention paid to the thermally-induced solid-state reaction allowing preparation of zero-valent iron nanoparticles in an industrial scale. Moreover, the method of thermal reduction of iron-oxide precursors enables to finely tune the critical parameters (mainly particle size and morphology, specific surface area, surface chemistry of nanoparticles etc.) of resulting zero-valet iron nanoparticles. The most important trends of advanced nanoparticles development will be discussed: (i) surface modification of nanomaterilas, (ii) development of nanocomposites and (iii) development of materials for combined reductive-sorption technologies. Laboratory testing of zero-valent iron nanoparticles reactivity and migration will be presented and compared with the field observations: the advanced zero-valent iron nanoparticles were used for groundwater treatment at the locality contaminated by chlorinated hydrocarbons (VC, DCE, TCE and PCE) and reacted nanoparticles were extracted from the sediments for their fate assessment. The authors gratefully acknowledge the support by the Technology Agency of the Czech Republic "Competence Centres" (project No. TE01020218) and the EU FP7 (project NANOREM).

  1. Stability of flat zero-energy states at the dirty surface of a nodal superconductor

    NASA Astrophysics Data System (ADS)

    Ikegaya, Satoshi; Asano, Yasuhiro

    2017-06-01

    We discuss the stability of highly degenerate zero-energy states that appear at the surface of a nodal superconductor preserving time-reversal symmetry. The existence of such surface states is a direct consequence of the nontrivial topological numbers defined in the restricted Brillouin zones in the clean limit. In experiments, however, potential disorder is inevitable near the surface of a real superconductor, which may lift the high degeneracy at zero energy. We show that an index defined in terms of the chiral eigenvalues of the zero-energy states can be used to measure the degree of degeneracy at zero energy in the presence of potential disorder. We also discuss the relationship between the index and the topological numbers.

  2. Estimating wind-turbine-caused bird and bat fatality when zero carcasses are observed.

    PubMed

    Huso, Manuela M P; Dalthorp, Dan; Dail, David; Madsen, Lisa

    2015-07-01

    Many wind-power facilities in the United States have established effective monitoring programs to determine turbine-caused fatality rates of birds and bats, but estimating the number of fatalities of rare species poses special difficulties. The loss of even small numbers of individuals may adversely affect fragile populations, but typically, few (if any) carcasses are observed during monitoring. If monitoring design results in only a small proportion of carcasses detected, then finding zero carcasses may give little assurance that the number of actual fatalities is small. Fatality monitoring at wind-power facilities commonly involves conducting experiments to estimate the probability (g) an individual will be observed, accounting for the possibilities that it falls in an unsearched area, is scavenged prior to detection, or remains undetected even when present. When g < 1, the total carcass count (X) underestimates the total number of fatalities (M). Total counts can be 0 when M is small or when M is large and g < 1. Distinguishing these two cases is critical when estimating fatality of a rare species. Observing no individuals during searches may erroneously be interpreted as evidence of absence. We present an approach that uses Bayes' theorem to construct a posterior distribution for M, i.e., P(M \\ X, ĝ), reflecting the observed carcass count and previously estimated g. From this distribution, we calculate two values important to conservation: the probability that M is below a predetermined limit and the upper bound (M*) of the 100(1 - α)% credible interval for M. We investigate the dependence of M* on α, g, and the prior distribution of M, asking what value of g is required to attain a desired M for a given α. We found that when g < -0.15, M* was clearly influenced by the mean and variance of ĝ and the choice of prior distribution for M, but the influence of these factors is minimal when g > -0.45. Further, we develop extensions for temporal replication that

  3. Critical Power: An Important Fatigue Threshold in Exercise Physiology

    PubMed Central

    Poole, David C.; Burnley, Mark; Vanhatalo, Anni; Rossiter, Harry B.; Jones, Andrew M.

    2016-01-01

    The hyperbolic form of the power-duration relationship is rigorous and highly conserved across species, forms of exercise and individual muscles/muscle groups. For modalities such as cycling, the relationship resolves to two parameters, the asymptote for power (critical power, CP) and the so-called W′ (work doable above CP), which together predict the tolerable duration of exercise above CP. Crucially, the CP concept integrates sentinel physiological profiles - respiratory, metabolic and contractile - within a coherent framework that has great scientific and practical utility. Rather than calibrating equivalent exercise intensities relative to metabolically distant parameters such as the lactate threshold or V̇O2 max, setting the exercise intensity relative to CP unifies the profile of systemic and intramuscular responses and, if greater than CP, predicts the tolerable duration of exercise until W′ is expended, V̇O2 max is attained, and intolerance is manifested. CP may be regarded as a ‘fatigue threshold’ in the sense that it separates exercise intensity domains within which the physiological responses to exercise can (CP) be stabilized. The CP concept therefore enables important insights into 1) the principal loci of fatigue development (central vs. peripheral) at different intensities of exercise, and 2) mechanisms of cardiovascular and metabolic control and their modulation by factors such as O2 delivery. Practically, the CP concept has great potential application in optimizing athletic training programs and performance as well as improving the life quality for individuals enduring chronic disease. PMID:27031742

  4. Critical Power: An Important Fatigue Threshold in Exercise Physiology.

    PubMed

    Poole, David C; Burnley, Mark; Vanhatalo, Anni; Rossiter, Harry B; Jones, Andrew M

    2016-11-01

    : The hyperbolic form of the power-duration relationship is rigorous and highly conserved across species, forms of exercise, and individual muscles/muscle groups. For modalities such as cycling, the relationship resolves to two parameters, the asymptote for power (critical power [CP]) and the so-called W' (work doable above CP), which together predict the tolerable duration of exercise above CP. Crucially, the CP concept integrates sentinel physiological profiles-respiratory, metabolic, and contractile-within a coherent framework that has great scientific and practical utility. Rather than calibrating equivalent exercise intensities relative to metabolically distant parameters such as the lactate threshold or V˙O2max, setting the exercise intensity relative to CP unifies the profile of systemic and intramuscular responses and, if greater than CP, predicts the tolerable duration of exercise until W' is expended, V˙O2max is attained, and intolerance is manifested. CP may be regarded as a "fatigue threshold" in the sense that it separates exercise intensity domains within which the physiological responses to exercise can (CP) be stabilized. The CP concept therefore enables important insights into 1) the principal loci of fatigue development (central vs. peripheral) at different intensities of exercise and 2) mechanisms of cardiovascular and metabolic control and their modulation by factors such as O2 delivery. Practically, the CP concept has great potential application in optimizing athletic training programs and performance as well as improving the life quality for individuals enduring chronic disease.

  5. Apollo-Soyuz pamphlet no. 8: Zero-g technology. [experimental designispace processing and aerospace engineering

    NASA Technical Reports Server (NTRS)

    Page, L. W.; From, T. P.

    1977-01-01

    The behavior of liquids in zero gravity environments is discussed with emphasis on foams, wetting, and wicks. A multipurpose electric furnace (MA-010) for the high temperature processing of metals and salts in zero-g is described. Experiments discussed include: monolectic and synthetic alloys (MA-041); multiple material melting point (MA-150); zero-g processing of metals (MA-070); surface tension induced convection (MA-041); halide eutectic growth; interface markings in crystals (MA-060); crystal growth from the vapor phase (MA-085); and photography of crystal growth (MA-028).

  6. Glass fining experiments in zero gravity

    NASA Technical Reports Server (NTRS)

    Smith, H. D.

    1977-01-01

    Ground based experiments were conducted to demonstrate that thermal migration actually operated in glass melts. Thermal migration consistent with the theory was found in one experiment on a borax melt, i.e., there was an approximately linear relation between the bubble diameter and bubble velocity for a given temperature and temperature gradient. It also appeared that nearby bubbles were attracted to one another, which could greatly aid fining. Interpretation of these results was not possible because of complications arising from gravity, i.e., floating of the bubbles, circulation currents due to buoyancy-driven natural connection, and flow of the melt out from the cell.

  7. Neutral Pion Production in MINERvA

    NASA Astrophysics Data System (ADS)

    Palomino, Jose

    2012-03-01

    MINERνA is a neutrino-nucleus scattering experiment employing multiple nuclear targets. The experiment is searching for neutral pion production, both in charged current and neutral current, from coherent, resonant and deep-inelastic processes off these targets. Neutral pions are detected through the 2 photon decay that then produce electromagnetic showers. We will describe how we isolate and reconstruct the electromagnetic showers to calculate the invariant mass of the photon pair.

  8. Measurement of Critical Contact Angle in a Microgravity Space Experiment

    NASA Technical Reports Server (NTRS)

    Concus, P.; Finn, R.; Weislogel, M.

    1998-01-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USML-2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  9. Measurement of Critical Contact Angle in a Microgravity Space Experiment

    NASA Technical Reports Server (NTRS)

    Concus, P.; Finn, R.; Weislogel, M.

    1998-01-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USMT,2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  10. Tolerating Zero Tolerance?

    ERIC Educational Resources Information Center

    Moore, Brian N.

    2010-01-01

    The concept of zero tolerance dates back to the mid-1990s when New Jersey was creating laws to address nuisance crimes in communities. The main goal of these neighborhood crime policies was to have zero tolerance for petty crime such as graffiti or littering so as to keep more serious crimes from occurring. Next came the war on drugs. In federal…

  11. Managing nurses through disciplinary power: a Foucauldian analysis of workplace violence.

    PubMed

    St-Pierre, Isabelle; Holmes, Dave

    2008-04-01

    This paper describes discipline as a specific technique of power which constitutes, in our view, a form of institutional violence. The need to create and maintain safe and healthy work environments for healthcare professionals is well documented. Foucault's concept of disciplinary power was used to explore institutional violence from a critical perspective. Violence is identified as an important factor in the recruitment and retention of healthcare professionals. Given the shortage of such professionals, there is an urgent need to take a fresh look at their working environments and working conditions. Power, surveillance and disciplinary techniques are used at all levels of hospital management to control and contain both human resources and costs. By associating common workplace practices with institutional violence, employers who have a policy of zero tolerance toward workplace violence will need to re-examine their current ways of operating.

  12. On the experience of feeling powerful: perceived power moderates the effect of stereotype threat on women's math performance.

    PubMed

    Van Loo, Katie J; Rydell, Robert J

    2013-03-01

    This research examined whether feeling powerful can eliminate the deleterious effect of stereotype threat (i.e., concerns about confirming a negative self-relevant stereotype) on women's math performance. In Experiments 1 and 2, priming women with high power buffered them from reduced math performance in response to stereotype threat instructions, whereas women in the low and control power conditions showed poorer math performance in response to threat. Experiment 3 found that working memory capacity is one mechanism through which power moderates the effect of threat on women's math performance. In the low and control power conditions, women showed reduced working memory capacity in response to stereotype threat, accounting for threat's effect on performance. In contrast, women in the high power condition did not show reductions in working memory capacity or math performance in response to threat. This work demonstrates that perceived power moderates stereotype threat-based performance effects and explains why this occurs.

  13. Critical spreading dynamics of parity conserving annihilating random walks with power-law branching

    NASA Astrophysics Data System (ADS)

    Laise, T.; dos Anjos, F. C.; Argolo, C.; Lyra, M. L.

    2018-09-01

    We investigate the critical spreading of the parity conserving annihilating random walks model with Lévy-like branching. The random walks are considered to perform normal diffusion with probability p on the sites of a one-dimensional lattice, annihilating in pairs by contact. With probability 1 - p, each particle can also produce two offspring which are placed at a distance r from the original site following a power-law Lévy-like distribution P(r) ∝ 1 /rα. We perform numerical simulations starting from a single particle. A finite-time scaling analysis is employed to locate the critical diffusion probability pc below which a finite density of particles is developed in the long-time limit. Further, we estimate the spreading dynamical exponents related to the increase of the average number of particles at the critical point and its respective fluctuations. The critical exponents deviate from those of the counterpart model with short-range branching for small values of α. The numerical data suggest that continuously varying spreading exponents sets up while the branching process still results in a diffusive-like spreading.

  14. Beyond Zero Based Budgeting.

    ERIC Educational Resources Information Center

    Ogden, Daniel M., Jr.

    1978-01-01

    Suggests that the most practical budgeting system for most managers is a formalized combination of incremental and zero-based analysis because little can be learned about most programs from an annual zero-based budget. (Author/IRT)

  15. LPT. Low power test (TAN640) interior. Basement level. Camera facing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LPT. Low power test (TAN-640) interior. Basement level. Camera facing north. Cable trays and conduit cross tunnel between critical experiment cell and critical experiment control room. Construction 93% complete. Photographer: Jack L. Anderson. Date: October 23, 1957. INEEL negative no. 57-5339 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  16. The Impact of Simulation-Based Learning Experience on Critical Thinking Acquisition

    ERIC Educational Resources Information Center

    Rome, Candice

    2012-01-01

    The purpose of this comparative experimental project was to compare the impact of simulation-based learning experiences to traditional clinical rotations on critical thinking acquisition of associate nursing students within a maternal-child course. Innovative pedagogies have been integrated in nursing programs to augment inadequate clinical…

  17. Nuclear Power Plant Mechanical Component Flooding Fragility Experiments Status

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

    Pope, C. L.; Savage, B.; Johnson, B.

    This report describes progress on Nuclear Power Plant mechanical component flooding fragility experiments and supporting research. The progress includes execution of full scale fragility experiments using hollow-core doors, design of improvements to the Portal Evaluation Tank, equipment procurement and initial installation of PET improvements, designation of experiments exploiting the improved PET capabilities, fragility mathematical model development, Smoothed Particle Hydrodynamic simulations, wave impact simulation device research, and pipe rupture mechanics research.

  18. Nurses’ Experiences of Managing and Management in a Critical Care Unit

    PubMed Central

    Ogle, K. Robyn; Glass, Nel

    2014-01-01

    In this article, we describe the major findings of an ethnographic study undertaken to investigate nurses’ experiences of managing nurses and being managed by nurses in an Australian critical care unit. Our purpose was to valorize and make space for nurses to speak of their experiences and investigate the cultural practices and knowledges that comprised nursing management discourses. Subjugated practices, knowledges, and discourses were identified, revealing how nurses were inscribed by, or resisted, the discourses, including their multiple mobile subject positions. Informed by critical, feminist, and postmodern perspectives, nine mobile subject positions were identified. Direct participant observation, participant interviews, and reflective field notes were analyzed for dominant and subjugated discourses. The major finding described is the subject position of “junior novice.” Nurses informed by dominant patriarchal and organizational discourses participated in constructing and reinscribing their own submissive identity reflected in interprofessional relations that lacked individual valuing and undermined their self-esteem. PMID:28462287

  19. Inclusive Financial Literacy Education for Inspiring a Critical Financial Consciousness: An Experiment in Partnership with Marginalised Youth

    ERIC Educational Resources Information Center

    Visano, Brenda Spotton; Ek-Udofia, Imo

    2017-01-01

    In the absence of critical inquiry, traditional financial literacy education risks socialising economically marginalised groups into an acceptance of the very power structures that created their marginalisation in the first place. The instructor-facilitator seeking to confront the challenge of promoting critical thinking about a subject widely…

  20. Catalytic transformation of persistent contaminants using a new composite material based on nanosized zero-valent metal - field experiment results

    NASA Astrophysics Data System (ADS)

    Dror, I.; Merom Jacov, O.; Berkowitz, B.

    2010-12-01

    A new composite material based on deposition of nanosized zero valent iron (ZVI) particles and cyanocobalamine (vitamin B12) on a diatomite matrix is presented. Cyanocobalamine is known to be an effective electron mediator, having strong synergistic effects with ZVI for reductive dehalogenation reactions. This composite material also improves the reducing capacity of nanosized ZVI by preventing agglomeration of iron particles, thus increasing their active surface area. The porous structure of the diatomite matrix allows high hydraulic conductivity, which favors channeling of contaminated water to the reactive surface of the composite material and in turn faster rates of remediation. The ability of the material to degrade or transform rapidly and completely a large spectrum of water pollutants will be demonstrated, based on results from two field site experiments where polluted groundwater containing a mixture of industrial and agricultural persistent pollutants was treated. In addition a set of laboratory experiments using individual contaminant solutions to analyze chemical transformations under controlled conditions will be presented.

  1. Crew Training - STS-33/51L (Zero-G)

    NASA Image and Video Library

    1985-10-16

    S85-42470 (16 Oct. 1985) --- Sharon Christa McAuliffe, right, and Barbara R. Morgan, participating in the Teacher-in-Space Project, team up with Bob Mayfield, a JSC aerospace educations specialist, to preview some experiments in zero-G. A KC-135 aircraft flies a special pattern to provide series of brief periods of weightlessness. McAuliffe, prime crew member for STS-51L, injects a hydroponic solution into a cylinder to review one of the experiments planned for the flight. Morgan is backup for McAuliffe on that mission. Photo credit: NASA

  2. Wave-packet formation at the zero-dispersion point in the Gardner-Ostrovsky equation.

    PubMed

    Whitfield, A J; Johnson, E R

    2015-05-01

    The long-time effect of weak rotation on an internal solitary wave is the decay into inertia-gravity waves and the eventual emergence of a coherent, steadily propagating, nonlinear wave packet. There is currently no entirely satisfactory explanation as to why these wave packets form. Here the initial value problem is considered within the context of the Gardner-Ostrovsky, or rotation-modified extended Korteweg-de Vries, equation. The linear Gardner-Ostrovsky equation has maximum group velocity at a critical wave number, often called the zero-dispersion point. It is found here that a nonlinear splitting of the wave-number spectrum at the zero-dispersion point, where energy is shifted into the modulationally unstable regime of the Gardner-Ostrovsky equation, is responsible for the wave-packet formation. Numerical comparisons of the decay of a solitary wave in the Gardner-Ostrovsky equation and a derived nonlinear Schrödinger equation at the zero-dispersion point are used to confirm the spectral splitting.

  3. Network information attacks on the control systems of power facilities belonging to the critical infrastructure

    NASA Astrophysics Data System (ADS)

    Loginov, E. L.; Raikov, A. N.

    2015-04-01

    The most large-scale accidents occurred as a consequence of network information attacks on the control systems of power facilities belonging to the United States' critical infrastructure are analyzed in the context of possibilities available in modern decision support systems. Trends in the development of technologies for inflicting damage to smart grids are formulated. A volume matrix of parameters characterizing attacks on facilities is constructed. A model describing the performance of a critical infrastructure's control system after an attack is developed. The recently adopted measures and legislation acts aimed at achieving more efficient protection of critical infrastructure are considered. Approaches to cognitive modeling and networked expertise of intricate situations for supporting the decision-making process, and to setting up a system of indicators for anticipatory monitoring of critical infrastructure are proposed.

  4. Microwave zero-resistance states in a bilayer electron system.

    PubMed

    Wiedmann, S; Gusev, G M; Raichev, O E; Bakarov, A K; Portal, J C

    2010-07-09

    Magnetotransport measurements on a high-mobility electron bilayer system formed in a wide GaAs quantum well reveal vanishing dissipative resistance under continuous microwave irradiation. Profound zero-resistance states (ZRS) appear even in the presence of additional intersubband scattering of electrons. We study the dependence of photoresistance on frequency, microwave power, and temperature. Experimental results are compared with a theory demonstrating that the conditions for absolute negative resistivity correlate with the appearance of ZRS.

  5. Numerical calculation of phase-matching properties in photonic crystal fibers with three and four zero-dispersion wavelengths.

    PubMed

    Zhao, Xingtao; Liu, Xiaoxu; Wang, Shutao; Wang, Wei; Han, Ying; Liu, Zhaolun; Li, Shuguang; Hou, Lantian

    2015-10-19

    Photonic crystal fibers with three and four zero-dispersion wavelengths are presented through special design of the structural parameters, in which the closing to zero and ultra-flattened dispersion can be obtained. The unique phase-matching properties of the fibers with three and four zero-dispersion wavelengths are analyzed. Variation of the phase-matching wavelengths with the pump wavelengths, pump powers, dispersion properties, and fiber structural parameters is analyzed. The presence of three and four zero-dispersion wavelengths can realize wavelength conversion of optical soliton between two anomalous dispersion regions, generate six phase-matching sidebands through four-wave mixing and create more new photon pairs, which can be used for the study of supercontinuum generation, optical switches and quantum optics.

  6. Workflow for Criticality Assessment Applied in Biopharmaceutical Process Validation Stage 1.

    PubMed

    Zahel, Thomas; Marschall, Lukas; Abad, Sandra; Vasilieva, Elena; Maurer, Daniel; Mueller, Eric M; Murphy, Patrick; Natschläger, Thomas; Brocard, Cécile; Reinisch, Daniela; Sagmeister, Patrick; Herwig, Christoph

    2017-10-12

    Identification of critical process parameters that impact product quality is a central task during regulatory requested process validation. Commonly, this is done via design of experiments and identification of parameters significantly impacting product quality (rejection of the null hypothesis that the effect equals 0). However, parameters which show a large uncertainty and might result in an undesirable product quality limit critical to the product, may be missed. This might occur during the evaluation of experiments since residual/un-modelled variance in the experiments is larger than expected a priori. Estimation of such a risk is the task of the presented novel retrospective power analysis permutation test. This is evaluated using a data set for two unit operations established during characterization of a biopharmaceutical process in industry. The results show that, for one unit operation, the observed variance in the experiments is much larger than expected a priori, resulting in low power levels for all non-significant parameters. Moreover, we present a workflow of how to mitigate the risk associated with overlooked parameter effects. This enables a statistically sound identification of critical process parameters. The developed workflow will substantially support industry in delivering constant product quality, reduce process variance and increase patient safety.

  7. An Improved Zero Potential Circuit for Readout of a Two-Dimensional Resistive Sensor Array.

    PubMed

    Wu, Jian-Feng; Wang, Feng; Wang, Qi; Li, Jian-Qing; Song, Ai-Guo

    2016-12-06

    With one operational amplifier (op-amp) in negative feedback, the traditional zero potential circuit could access one element in the two-dimensional (2-D) resistive sensor array with the shared row-column fashion but it suffered from the crosstalk problem for the non-scanned elements' bypass currents, which were injected into array's non-scanned electrodes from zero potential. Firstly, for suppressing the crosstalk problem, we designed a novel improved zero potential circuit with one more op-amp in negative feedback to sample the total bypass current and calculate the precision resistance of the element being tested (EBT) with it. The improved setting non-scanned-electrode zero potential circuit (S-NSE-ZPC) was given as an example for analyzing and verifying the performance of the improved zero potential circuit. Secondly, in the S-NSE-ZPC and the improved S-NSE-ZPC, the effects of different parameters of the resistive sensor arrays and their readout circuits on the EBT's measurement accuracy were simulated with the NI Multisim 12. Thirdly, part features of the improved circuit were verified with the experiments of a prototype circuit. Followed, the results were discussed and the conclusions were given. The experiment results show that the improved circuit, though it requires one more op-amp, one more resistor and one more sampling channel, can access the EBT in the 2-D resistive sensor array more accurately.

  8. Nuclear Effects in Quasi-Elastic and Delta Resonance Production at Low Momentum Transfer

    NASA Astrophysics Data System (ADS)

    Demgen, John Gibney

    Analysis of data collected by the MINERvA experiment is done by showing the distribution of charged hadron energy for interactions that have low momentum transfer. This distribution reveals major discrepancies between the detector data and the standard MINERvA interaction model with only a simple global Fermi gas model. Adding additional model elements, the random phase approximation (RPA), meson exchange current (MEC), and a reduction of resonance delta production improve this discrepancy. Special attention is paid to resonance delta production systematic uncertainties, which do not make up these discrepancies even when added with resolution and biasing systematic uncertainties. Eye- scanning of events in this region also show a discrepancy, but we were insensitive to two-proton events, the predicted signature of the MEC process.

  9. The challenges of caring in a technological environment: critical care nurses' experiences.

    PubMed

    McGrath, Mary

    2008-04-01

    This paper presents and discusses the findings from a phenomenological study which illuminated the lived experiences of experienced critical care nurses caring within a technological environment. While nursing practice is interwoven with technology, much of the literature in this area is speculative. Moreover, there is a debate as to whether and how 'high tech' and 'high touch' are reconcilable; this orientation is referred to as the optimism vs. pessimism debate. On a personal level, the motivation for this study came from the author's 13 years' experience in the critical care area. Following ethical approval, 10 experienced nurses from two cardiothoracic critical care units in Ireland participated in the study. A Heideggerian phenomenological methodology was used. Data collection consisted of unstructured interviews. A method of data analysis described by Walters was used. The findings provide research-based evidence to illuminate further the optimistic/pessimistic debate on technology in nursing. While the study demonstrates that the debate is far from resolved, it reveals a new finding: life-saving technology that supports the lives of critically ill patients can bring experienced nurses very close to their patients/families. The three main themes that emerged: 'alien environment', 'pulling together' and 'sharing the journey' were linked by a common thread of caring. Experienced critical care nurses are able to transcend the obtrusive nature of technology to deliver expert caring to their patients. However, the journey to proficiency in technology is very demanding and novice nurses have difficulty in caring with technology. Relevance to clinical practice. It is recommended that more emphasis be placed on supporting, assisting and educating inexperienced nurses in the critical care area and that the use of technology in nursing be given serious consideration.

  10. Unconventional and conventional quantum criticalities in CeRh0.58Ir0.42In5

    NASA Astrophysics Data System (ADS)

    Luo, Yongkang; Lu, Xin; Dioguardi, Aadm P.; Rosa, Priscila F. S.; Bauer, Eric D.; Si, Qimiao; Thompson, Joe D.

    2018-03-01

    An appropriate description of the state of matter that appears as a second order phase transition is tuned toward zero temperature, viz. quantum-critical point (QCP), poses fundamental and still not fully answered questions. Experiments are needed both to test basic conclusions and to guide further refinement of theoretical models. Here, charge and entropy transport properties as well as AC specific heat of the heavy-fermion compound CeRh0.58Ir0.42In5, measured as a function of pressure, reveal two qualitatively different QCPs in a single material driven by a single non-symmetry-breaking tuning parameter. A discontinuous sign-change jump in thermopower suggests an unconventional QCP at pc1 accompanied by an abrupt Fermi-surface reconstruction that is followed by a conventional spin-density-wave critical point at pc2 across which the Fermi surface evolves smoothly to a heavy Fermi-liquid state. These experiments are consistent with some theoretical predictions, including the sequence of critical points and the temperature dependence of the thermopower in their vicinity.

  11. A criticality result for polycycles in a family of quadratic reversible centers

    NASA Astrophysics Data System (ADS)

    Rojas, D.; Villadelprat, J.

    2018-06-01

    We consider the family of dehomogenized Loud's centers Xμ = y (x - 1)∂x + (x + Dx2 + Fy2)∂y, where μ = (D , F) ∈R2, and we study the number of critical periodic orbits that emerge or disappear from the polycycle at the boundary of the period annulus. This number is defined exactly the same way as the well-known notion of cyclicity of a limit periodic set and we call it criticality. The previous results on the issue for the family {Xμ , μ ∈R2 } distinguish between parameters with criticality equal to zero (regular parameters) and those with criticality greater than zero (bifurcation parameters). A challenging problem not tackled so far is the computation of the criticality of the bifurcation parameters, which form a set ΓB of codimension 1 in R2. In the present paper we succeed in proving that a subset of ΓB has criticality equal to one.

  12. Recalled peer relationship experiences and current levels of self-criticism and self-reassurance.

    PubMed

    Kopala-Sibley, Daniel C; Zuroff, David C; Leybman, Michelle J; Hope, Nora

    2013-03-01

    Numerous studies have shown that personality factors may increase or decrease individuals' vulnerability to depression, but little research has examined the role of peer relationships in the development of these factors. Accordingly, this study examined the role of recalled parenting and peer experiences in the development of self-criticism and self-reassurance. It was hypothesized that, controlling for recalled parenting behaviours, specific recalled experiences of peer relationships would be related to current levels of specific forms of self-criticism and self-reassurance. Hypotheses were tested using a retrospective design in which participants were asked to recall experiences of parenting and peer relationships during early adolescence. This age was chosen as early adolescence has been shown to be a critical time for the development of vulnerability to depression. A total of 103 female and 97 male young adults completed measures of recalled parenting, overt and relational victimization and prosocial behaviour by peers, and current levels of self-criticism and self-reassurance. Hierarchical regression analyses showed that parents and peers independently contributed to the development of self-criticism and self-reassurance. Specifically, controlling for parental care and control, overt victimization predicted self-hating self-criticism, relational victimization predicted inadequacy self-criticism, and prosocial behaviour predicted self-reassurance. As well, prosocial behaviour buffered the effect of overt victimization on self-reassurance. Findings highlight the importance of peers in the development of personality risk and resiliency factors for depression, and suggest avenues for interventions to prevent the development of depressive vulnerabilities in youth. The nature of a patient's personality vulnerability to depression may be better understood through a consideration of the patient's relationships with their peers as well as with parents during

  13. Simulation experience enhances physical therapist student confidence in managing a patient in the critical care environment.

    PubMed

    Ohtake, Patricia J; Lazarus, Marcilene; Schillo, Rebecca; Rosen, Michael

    2013-02-01

    Rehabilitation of patients in critical care environments improves functional outcomes. This finding has led to increased implementation of intensive care unit (ICU) rehabilitation programs, including early mobility, and an associated increased demand for physical therapists practicing in ICUs. Unfortunately, many physical therapists report being inadequately prepared to work in this high-risk environment. Simulation provides focused, deliberate practice in safe, controlled learning environments and may be a method to initiate academic preparation of physical therapists for ICU practice. The purpose of this study was to examine the effect of participation in simulation-based management of a patient with critical illness in an ICU setting on levels of confidence and satisfaction in physical therapist students. A one-group, pretest-posttest, quasi-experimental design was used. Physical therapist students (N=43) participated in a critical care simulation experience requiring technical (assessing bed mobility and pulmonary status), behavioral (patient and interprofessional communication), and cognitive (recognizing a patient status change and initiating appropriate responses) skill performance. Student confidence and satisfaction were surveyed before and after the simulation experience. Students' confidence in their technical, behavioral, and cognitive skill performance increased from "somewhat confident" to "confident" following the critical care simulation experience. Student satisfaction was highly positive, with strong agreement the simulation experience was valuable, reinforced course content, and was a useful educational tool. Limitations of the study were the small sample from one university and a control group was not included. Incorporating a simulated, interprofessional critical care experience into a required clinical course improved physical therapist student confidence in technical, behavioral, and cognitive performance measures and was associated with high

  14. Electron acceleration in pulsed-power driven magnetic-reconnection experiments

    NASA Astrophysics Data System (ADS)

    Halliday, Jonathan; Hare, Jack; Lebedev, Sergey; Suttle, Lee; Bland, Simon; Clayson, Thomas; Tubman, Eleanor; Pikuz, Sergei; Shelkovenko, Tanya

    2017-10-01

    We present recent results from pulsed-power driven magnetic reconnection experiments, fielded on the MAGPIE generator (1.2 MA, 250 ns). The setup used in these experiments produces plasma inflows which are intrinsically magnetised; persist for many hydrodynamic time-scales; and are supersonic. Previous work has focussed on characterising the dynamics of bulk plasma flows, using a suite of diagnostics including laser interferometry, (imaging) Faraday rotation, and Thompson scattering. Measurements show the formation of a well defined, long lasting reconnection layer and demonstrate a power balance between the power into and out of the reconnection region. The work presented here focuses on diagnosing non-thermal electron acceleration by the reconnecting electric field. To achieve this, metal foils were placed in the path of accelerated electrons. Atomic transitions in the foil were collisionally exited by the electron beam, producing a characteristic X-Ray spectrum. This X-Ray emission was diagnosed using spherically bent crystal X-Ray spectrometry, filtered X-Ray pinhole imaging, and X-Ray sensitive PIN diodes.

  15. Development and characteristics of the hardware for Skylab experiment S015

    NASA Technical Reports Server (NTRS)

    Thirolf, R. G.

    1975-01-01

    Details are given regarding the hardware for the Skylab S015 experiment, which was designed to detect the effects of zero gravity on cell growth rates. Experience gained in hardware-related considerations is presented for use of researchers concerned with future research of this type and further study of the S015 results. Brief descriptions are given of the experiment hardware, the hardware configuration for the critical design review, the major configuration changes, the final configuration, and the postflight review and analysis. An appendix describes pertinent documentation, film, and hardware that are available to qualified researchers; sources for additional or special information are given.

  16. Spin zero Hawking radiation for non-zero-angular momentum mode

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

    Ngampitipan, Tritos; Bonserm, Petarpa; Visser, Matt

    2015-05-15

    Black hole greybody factors carry some quantum black hole information. Studying greybody factors may lead to understanding the quantum nature of black holes. However, solving for exact greybody factors in many black hole systems is impossible. One way to deal with this problem is to place some rigorous analytic bounds on the greybody factors. In this paper, we calculate rigorous bounds on the greybody factors for spin zero hawking radiation for non-zero-angular momentum mode from the Kerr-Newman black holes.

  17. High-speed zero-copy data transfer for DAQ applications

    NASA Astrophysics Data System (ADS)

    Pisani, Flavio; Cámpora Pérez, Daniel Hugo; Neufeld, Niko

    2015-05-01

    The LHCb Data Acquisition (DAQ) will be upgraded in 2020 to a trigger-free readout. In order to achieve this goal we will need to connect around 500 nodes with a total network capacity of 32 Tb/s. To get such an high network capacity we are testing zero-copy technology in order to maximize the theoretical link throughput without adding excessive CPU and memory bandwidth overhead, leaving free resources for data processing resulting in less power, space and money used for the same result. We develop a modular test application which can be used with different transport layers. For the zero-copy implementation we choose the OFED IBVerbs API because it can provide low level access and high throughput. We present throughput and CPU usage measurements of 40 GbE solutions using Remote Direct Memory Access (RDMA), for several network configurations to test the scalability of the system.

  18. When subjective experiences matter: power increases reliance on the ease of retrieval.

    PubMed

    Weick, Mario; Guinote, Ana

    2008-06-01

    Past research on power focused exclusively on declarative knowledge and neglected the role of subjective experiences. Five studies tested the hypothesis that power increases reliance on the experienced ease or difficulty that accompanies thought generation. Across a variety of targets, such as attitudes, leisure-time satisfaction, and stereotyping, and with different operationalizations of power, including priming, trait dominance, and actual power in managerial contexts, power consistently increased reliance on the ease of retrieval. These effects remained 1 week later and were not mediated by mood, quality of the retrieved information, or number of counterarguments. These findings indicate that powerful individuals construe their judgments on the basis of momentary subjective experiences and do not necessarily rely on core attitudes or prior knowledge, such as stereotypes. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

  19. Exponential protection of zero modes in Majorana islands.

    PubMed

    Albrecht, S M; Higginbotham, A P; Madsen, M; Kuemmeth, F; Jespersen, T S; Nygård, J; Krogstrup, P; Marcus, C M

    2016-03-10

    Majorana zero modes are quasiparticle excitations in condensed matter systems that have been proposed as building blocks of fault-tolerant quantum computers. They are expected to exhibit non-Abelian particle statistics, in contrast to the usual statistics of fermions and bosons, enabling quantum operations to be performed by braiding isolated modes around one another. Quantum braiding operations are topologically protected insofar as these modes are pinned near zero energy, with the departure from zero expected to be exponentially small as the modes become spatially separated. Following theoretical proposals, several experiments have identified signatures of Majorana modes in nanowires with proximity-induced superconductivity and atomic chains, with small amounts of mode splitting potentially explained by hybridization of Majorana modes. Here, we use Coulomb-blockade spectroscopy in an InAs nanowire segment with epitaxial aluminium, which forms a proximity-induced superconducting Coulomb island (a 'Majorana island') that is isolated from normal-metal leads by tunnel barriers, to measure the splitting of near-zero-energy Majorana modes. We observe exponential suppression of energy splitting with increasing wire length. For short devices of a few hundred nanometres, sub-gap state energies oscillate as the magnetic field is varied, as is expected for hybridized Majorana modes. Splitting decreases by a factor of about ten for each half a micrometre of increased wire length. For devices longer than about one micrometre, transport in strong magnetic fields occurs through a zero-energy state that is energetically isolated from a continuum, yielding uniformly spaced Coulomb-blockade conductance peaks, consistent with teleportation via Majorana modes. Our results help to explain the trivial-to-topological transition in finite systems and to quantify the scaling of topological protection with end-mode separation.

  20. Photovoltaic array space power plus diagnostics experiment

    NASA Technical Reports Server (NTRS)

    Burger, D. R.

    1990-01-01

    The objective is to summarize the five years of hardware development and fabrication represented by the Photovoltaic Array Space Power Plus Diagnostics (PASP Plus) Instrument. The original PASP Experiment requirements and background is presented along with the modifications which were requested to transform the PASP Experiment into the PASP Plus Instrument. The PASP Plus hardware and software is described. Test results for components and subsystems are given as well as final system tests. Also included are appendices which describe the major subsystems and present supporting documentation such as block diagrams, schematics, circuit board artwork, drawings, test procedures and test reports.