Science.gov

Sample records for annular core research

  1. Predicting Activation of Experiments Inside the Annular Core Research Reactor

    SciTech Connect

    Greenberg, Joseph Isaac

    2015-11-01

    The objective of this thesis is to create a program to quickly estimate the radioactivity and decay of experiments conducted inside of the Annular Core Research Reactor at Sandia National Laboratories and eliminate the need for users to write code. This is achieved by model the neutron fluxes in the reactor’s central cavity where experiments are conducted for 4 different neutron spectra using MCNP. The desired neutron spectrum, experiment material composition, and reactor power level are then input into CINDER2008 burnup code to obtain activation and decay information for every isotope generated. DREAD creates all of the files required for CINDER2008 through user selected inputs in a graphical user interface and executes the program for the user and displays the resulting estimation for dose rate at various distances. The DREAD program was validated by weighing and measuring various experiments in the different spectra and then collecting dose rate information after they were irradiated and comparing it to the dose rates that DREAD predicted. The program provides results with an average of 17% higher estimates than the actual values and takes seconds to execute.

  2. Reactor pulse repeatability studies at the annular core research reactor

    SciTech Connect

    DePriest, K.R.; Trinh, T.Q.; Luker, S. M.

    2011-07-01

    The Annular Core Research Reactor (ACRR) at Sandia National Laboratories is a water-moderated pool-type reactor designed for testing many types of objects in the pulse and steady-state mode of operations. Personnel at Sandia began working to improve the repeatability of pulse operations for experimenters in the facility. The ACRR has a unique UO{sub 2}-BeO fuel that makes the task of producing repeatable pulses difficult with the current operating procedure. The ACRR produces a significant quantity of photoneutrons through the {sup 9}Be({gamma}, n){sup 8}Be reaction in the fuel elements. The photoneutrons are the result of the gammas produced during fission and in fission product decay, so their production is very much dependent on the reactor power history and changes throughout the day/week of experiments in the facility. Because the photoneutrons interfere with the delayed-critical measurements required for accurate pulse reactivity prediction, a new operating procedure was created. The photoneutron effects at delayed critical are minimized when using the modified procedure. In addition, the pulse element removal time is standardized for all pulse operations with the modified procedure, and this produces less variation in reactivity removal times. (authors)

  3. Characterization of Novel Calorimeters in the Annular Core Research Reactor

    NASA Astrophysics Data System (ADS)

    Hehr, Brian D.; Parma, Edward J.; Peters, Curtis D.; Naranjo, Gerald E.; Luker, S. Michael

    2016-02-01

    A series of pulsed irradiation experiments have been performed in the central cavity of Sandia National Laboratories' Annular Core Research Reactor (ACRR) to characterize the responses of a set of elemental calorimeter materials including Si, Zr, Sn, Ta, W, and Bi. Of particular interest was the perturbing effect of the calorimeter itself on the ambient radiation field - a potential concern in dosimetry applications. By placing the calorimeter package into a neutron-thermalizing lead/polyethylene (LP) bucket and irradiating both with and without a cadmium wrapper, it was demonstrated that prompt capture gammas generated inside the calorimeters can be a significant contributor to the measured dose in the active disc region. An MCNP model of the experimental setup was shown to replicate measured dose responses to within 10%. The internal (n,γ) contribution was found to constitute as much as 50% of the response inside the LP bucket and up to 20% inside the nominal (unmodified) cavity environment, with Ta and W exhibiting the largest enhancement due to their sizable (n,γ) cross sections. Capture reactions in non-disc components of the calorimeter were estimated to be responsible for up to a few percent of the measured response. This work was supported by the United States Department of Energy under Contract DE-AC04-94AL85000. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy.

  4. Operational performance of the three bean salad control algorithm on the ACRR (Annular Core Research Reactor)

    SciTech Connect

    Ball, R.M.; Madaras, J.J. . Space and Defense Systems); Trowbridge, F.R. Jr.; Talley, D.G.; Parma, E.J. Jr. )

    1991-01-01

    Experimental tests on the Annular Core Research Reactor have confirmed that the Three-Bean-Salad'' control algorithm based on the Pontryagin maximum principle can change the power of a nuclear reactor many decades with a very fast startup rate and minimal overshoot. The paper describes the results of simulations and operations up to 25 MW and 87 decades per minute. 3 refs., 4 figs., 1 tab.

  5. Characterization of the Annular Core Research Reactor (ACRR) Neutron Radiography System Imaging Plane

    NASA Astrophysics Data System (ADS)

    Kaiser, Krista; Chantel Nowlen, K.; DePriest, K. Russell

    2016-02-01

    The Annular Core Research Reactor (ACRR) at Sandia National Laboratories (SNL) is an epithermal pool-type research reactor licensed up to a thermal power of 2.4 MW. The ACRR facility has a neutron radiography facility that is used for imaging a wide range of items including reactor fuel and neutron generators. The ACRR neutron radiography system has four apertures (65:1, 125:1, 250:1, and 500:1) available to experimenters. The neutron flux and spectrum as well as the gamma dose rate were characterized at the imaging plane for the ACRR's neutron radiography system for the 65:1, 125:1 and 250:1 apertures.

  6. Reactor physics calculations for {sup 99}Mo production at the annular core research reactor

    SciTech Connect

    Parma, E.J.

    1995-12-31

    The Isotope Production and Distribution Program at the U.S. Department of Energy has designated Sandia National Laboratories (SNL) as the most appropriate facility for the production of {sup 99}Mo, a radioisotope whose daughter, {sup 99m}Tc, is used in more than 36,000 medical procedures per day in the United States and is considered to be a vital medical diagnostic and treatment tool. The isotope would be produced at SNL using the annular core research reactor (ACRR) facility and collocated hot cell facility. The {sup 99}Mo would be produced using the fission process by irradiating {open_quotes}targets{close_quotes} coated with {sup 235}U in the form of highly enriched U{sub 3}O{sub 8}. After {approximately}7 days of continuous irradiation in the ACRR, a target would be re- moved from the reactor core for processing. The isotope would be extracted by chemically precipitating the molybdenum using the {open_quotes}Cintichem{close_quotes} process and would be shipped to the various pharmaceutical companies by commercial or chartered airline.

  7. Photoneutron effects on pulse reactor kinetics for the Annular Core Research Reactor (ACRR).

    SciTech Connect

    Parma, Edward J., Jr.

    2009-06-01

    The Annular Core Research Reactor (ACRR) is a swimming-pool type pulsed reactor that maintains an epithermal neutron flux and a nine-inch diameter central dry cavity. One of its uses is neutron and gamma-ray irradiation damage studies on electronic components under transient reactor power conditions. In analyzing the experimental results, careful attention must be paid to the kinetics associated with the reactor to ensure that the transient behavior of the electronic device is understood. Since the ACRR fuel maintains a substantial amount of beryllium, copious quantities of photoneutrons are produced that can significantly alter the expected behavior of the reactor power, especially following a reactor pulse. In order to understand these photoneutron effects on the reactor kinetics, the KIFLE transient reactor-analysis code was modified to include the photoneutron groups associated with the beryllium. The time-dependent behavior of the reactor power was analyzed for small and large pulses, assuming several initial conditions including following several pulses during the day, and following a long steady-state power run. The results indicate that, for these types of initial conditions, the photoneutron contribution to the reactor pulse energy can have a few to tens of percent effect.

  8. Neutron Environment Characterization of the Central Cavity in the Annular Core Research Reactor

    NASA Astrophysics Data System (ADS)

    Parma, Edward J.; Naranjo, Gerald E.; Lippert, Lance L.; Vehar, David W.

    2016-02-01

    Characterization of the neutron environment in the central cavity of the Sandia National Laboratories' Annular Core Research Reactor (ACRR) is important in order to provide experimenters with the most accurate spectral information and maintain a high degree of fidelity in performing reactor experiments. Characterization includes both modeling and experimental efforts. Building accurate neutronic models of the ACRR and the central cavity "bucket" environments that can be used by experimenters is important in planning and designing experiments, as well as assessing the experimental results and quantifying uncertainties. Neutron fluence characterizations of two bucket environments, LB44 and PLG, are presented. These two environments are used frequently and represent two extremes in the neutron spectrum. The LB44 bucket is designed to remove the thermal component of the neutron spectrum and significantly attenuate the gamma-ray fluence. The PLG bucket is designed to enhance the thermal component of the neutron spectrum and attenuate the gamma-ray fluence. The neutron characterization for each bucket was performed by irradiating 20 different activation foil types, some of which were cadmium covered, resulting in 37 different reactions at the peak axial flux location in each bucket. The dosimetry results were used in the LSL-M2 spectrum adjustment code with a 640-energy group MCNP-generated trial spectrum, self-shielding correction factors, the SNLRML or IRDFF dosimetry cross-section library, trial spectrum uncertainty, and trial covariance matrix, to generate a least-squares adjusted neutron spectrum, spectrum uncertainty, and covariance matrix. Both environment character-izations are well documented and the environments are available for use by experimenters. Work supported by the United States Department of Energy at Sandia National Laboratories. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned

  9. Safety analysis for operating the Annular Core Research Reactor with Cintichem-type targets installed in the central region of the core

    SciTech Connect

    PARMA JR.,EDWARD J.

    2000-01-01

    Production of the molybdenum-99 isotope at the Annular Core Research Reactor requires highly enriched, uranium oxide loaded targets to be irradiated for several days in the high neutron-flux region of the core. This report presents the safety analysis for the irradiation of up to seven Cintichem-type targets in the central region of the core and compares the results to the Annular Core Research Reactor Safety Analysis Report. A 19 target grid configuration is presented that allows one to seven targets to be irradiated, with the remainder of the grid locations filled with aluminum ''void'' targets. Analyses of reactor, neutronic, thermal hydraulics, and heat transfer calculations are presented. Steady-state operation and accident scenarios are analyzed with the conclusion that the reactor can be operated safely with seven targets in the grid, and no additional risk to the public.

  10. Lessons Learned from Sandia National Laboratories' Operational Readiness Review of the Annular Core Research Reactor (ACRR)

    SciTech Connect

    Bendure, Albert O.; Bryson, James W.

    1999-05-17

    The Sandia ACRR (a Hazard Category 2 Nuclear Reactor Facility) was defueled in June 1997 to modify the reactor core and control system to produce medical radioisotopes for the Department of Energy (DOE) Isotope Production Program. The DOE determined that an Operational Readiness Review (ORR) was required to confirm readiness to begin operations within the revised safety basis. This paper addresses the ORR Process, lessons learned from the Sandia and DOE ORRS of the ACRR, and the use of the ORR to confirm authorization basis implementation.

  11. Annular core liquid-salt cooled reactor with multiple fuel and blanket zones

    DOEpatents

    Peterson, Per F.

    2013-05-14

    A liquid fluoride salt cooled, high temperature reactor having a reactor vessel with a pebble-bed reactor core. The reactor core comprises a pebble injection inlet located at a bottom end of the reactor core and a pebble defueling outlet located at a top end of the reactor core, an inner reflector, outer reflector, and an annular pebble-bed region disposed in between the inner reflector and outer reflector. The annular pebble-bed region comprises an annular channel configured for receiving pebble fuel at the pebble injection inlet, the pebble fuel comprising a combination of seed and blanket pebbles having a density lower than the coolant such that the pebbles have positive buoyancy and migrate upward in said annular pebble-bed region toward the defueling outlet. The annular pebble-bed region comprises alternating radial layers of seed pebbles and blanket pebbles.

  12. Criticality Benchmark Analysis of the HTTR Annular Startup Core Configurations

    SciTech Connect

    John D. Bess

    2009-11-01

    One of the high priority benchmarking activities for corroborating the Next Generation Nuclear Plant (NGNP) Project and Very High Temperature Reactor (VHTR) Program is evaluation of Japan's existing High Temperature Engineering Test Reactor (HTTR). The HTTR is a 30 MWt engineering test reactor utilizing graphite moderation, helium coolant, and prismatic TRISO fuel. A large amount of critical reactor physics data is available for validation efforts of High Temperature Gas-cooled Reactors (HTGRs). Previous international reactor physics benchmarking activities provided a collation of mixed results that inaccurately predicted actual experimental performance.1 Reevaluations were performed by the Japanese to reduce the discrepancy between actual and computationally-determined critical configurations.2-3 Current efforts at the Idaho National Laboratory (INL) involve development of reactor physics benchmark models in conjunction with the International Reactor Physics Experiment Evaluation Project (IRPhEP) for use with verification and validation methods in the VHTR Program. Annular cores demonstrate inherent safety characteristics that are of interest in developing future HTGRs.

  13. Evaluation of the Start-Up Core Physics Tests at Japan's High Temperature Engineering Test Reactor (Annular Core Loadings)

    SciTech Connect

    John D. Bess; Nozomu Fujimoto; James W. Sterbentz; Luka Snoj; Atsushi Zukeran

    2010-03-01

    The High Temperature Engineering Test Reactor (HTTR) of the Japan Atomic Energy Agency (JAEA) is a 30 MWth, graphite-moderated, helium-cooled reactor that was constructed with the objectives to establish and upgrade the technological basis for advanced high-temperature gas-cooled reactors (HTGRs) as well as to conduct various irradiation tests for innovative high-temperature research. The core size of the HTTR represents about one-half of that of future HTGRs, and the high excess reactivity of the HTTR, necessary for compensation of temperature, xenon, and burnup effects during power operations, is similar to that of future HTGRs. During the start-up core physics tests of the HTTR, various annular cores were formed to provide experimental data for verification of design codes for future HTGRs. The Japanese government approved construction of the HTTR in the 1989 fiscal year budget; construction began at the Oarai Research and Development Center in March 1991 and was completed May 1996. Fuel loading began July 1, 1998, from the core periphery. The first criticality was attained with an annular core on November 10, 1998 at 14:18, followed by a series of start-up core physics tests until a fully-loaded core was developed on December 16, 1998. Criticality tests were carried out into January 1999. The first full power operation with an average core outlet temperature of 850ºC was completed on December 7, 2001, and operational licensing of the HTTR was approved on March 6, 2002. The HTTR attained high temperature operation at 950 ºC in April 19, 2004. After a series of safety demonstration tests, it will be used as the heat source in a hydrogen production system by 2015. Hot zero-power critical, rise-to-power, irradiation, and safety demonstration testing , have also been performed with the HTTR, representing additional means for computational validation efforts. Power tests were performed in steps from 0 to 30 MW, with various tests performed at each step to confirm

  14. Final Technical Report for the MIT Annular Fuel Research Project

    SciTech Connect

    Mujid S. Kazimi; Pavel Hejzlar

    2008-01-31

    MIT-NFC-PR-082 (January 2006) Abstract This summary provides an overview of the results of the U.S. DOE funded NERI (Nuclear Research ENergy Initiative) program on development of the internally and externally cooled annular fuel for high power density PWRs. This new fuel was proposed by MIT to allow a substantial increase in poer density (on the order of 30% or higher) while maintaining or improving safety margins. A comprehensive study was performed by a team consisting of MIT (lead organization), Westinghuse Electric Corporation, Gamma Engineering Corporation, Framatome ANP(formerly Duke Engineering) and Atomic Energy of Canada Limited.

  15. Lattice cell and full core physics of internally cooled annular fuel in heavy water moderated reactors

    SciTech Connect

    Armstrong, J.; Hamilton, H.; Hyland, B.

    2013-07-01

    A program is underway at Atomic Energy of Canada Limited (AECL) to develop a new fuel bundle concept to enable greater burnups for PT-HWR (pressure tube heavy water reactor) cores. One option that AECL is investigating is an internally cooled annular fuel (ICAF) element concept. ICAF contains annular cylindrical pellets with cladding on the inner and outer diameters. Coolant flows along the outside of the element and through the centre. With such a concept, the maximum fuel temperature as a function of linear element rating is significantly reduced compared to conventional, solid-rod type fuel. The preliminary ICAF bundle concept considered in this study contains 24 half-metre long internally cooled annular fuel elements and one non-fuelled centre pin. The introduction of the non-fuelled centre pin reduces the coolant void reactivity (CVR), which is the increase in reactivity that occurs on voiding the coolant in accident scenarios. Lattice cell and full core physics calculations of the preliminary ICAF fuel bundle concept have been performed for medium burnups of approximately 18 GWd/tU using WIMS-AECL and reactor fuel simulation program (RFSP). The results will be used to assist in concept configuration optimization. The effects of radial and axial core power distributions, linear element power ratings, refuelling rates and operational power ramps have been analyzed. The results suggest that burnups of greater than 18 GWd/tU can be achieved in current reactor designs. At approximately 18 GWd/tU, expected maximum linear element ratings in a PT-HWR with online-refuelling are approximately 90 kW/m. These conditions would be prohibitive for solid-rod fuel, but may be possible in ICAF fuel given the reduced maximum fuel temperature as a function of linear element rating. (authors)

  16. On the nonlinear interfacial instability of rotating core-annular flow

    NASA Technical Reports Server (NTRS)

    Coward, Aidrian V.; Hall, Philip

    1993-01-01

    The interfacial stability of rotating core-annular flows is investigated. The linear and nonlinear effects are considered for the case when the annular region is very thin. Both asymptotic and numerical methods are used to solve the flow in the core and film regions which are coupled by a difference in viscosity and density. The long-term behavior of the fluid-fluid interface is determined by deriving its nonlinear evolution in the form of a modified Kuramoto-Sivashinsky equation. We obtain a generalization of this equation to three dimensions. The flows considered are applicable to a wide array of physical problems where liquid films are used to lubricate higher or lower viscosity core fluids, for which a concentric arrangement is desired. Linearized solutions show that the effects of density and viscosity stratification are crucial to the stability of the interface. Rotation generally destabilizes non-axisymmetric disturbances to the interface, whereas the centripetal forces tend to stabilize flows in which the film contains the heavier fluid. Nonlinear affects allow finite amplitude helically travelling waves to exist when the fluids have different viscosities.

  17. Ring waves as a mass transport mechanism in air-driven core-annular flows.

    PubMed

    Camassa, Roberto; Forest, M Gregory; Lee, Long; Ogrosky, H Reed; Olander, Jeffrey

    2012-12-01

    Air-driven core-annular fluid flows occur in many situations, from lung airways to engineering applications. Here we study, experimentally and theoretically, flows where a viscous liquid film lining the inside of a tube is forced upwards against gravity by turbulent airflow up the center of the tube. We present results on the thickness and mean speed of the film and properties of the interfacial waves that develop from an instability of the air-liquid interface. We derive a long-wave asymptotic model and compare properties of its solutions with those of the experiments. Traveling wave solutions of this long-wave model exhibit evidence of different mass transport regimes: Past a certain threshold, sufficiently large-amplitude waves begin to trap cores of fluid which propagate upward at wave speeds. This theoretical result is then confirmed by a second set of experiments that show evidence of ring waves of annular fluid propagating over the underlying creeping flow. By tuning the parameters of the experiments, the strength of this phenomenon can be adjusted in a way that is predicted qualitatively by the model.

  18. Annular seed-blanket thorium fuel core concepts for heavy water moderated reactors

    SciTech Connect

    Bromley, B.P.; Hyland, B.

    2013-07-01

    New reactor concepts to implement thorium-based fuel cycles have been explored to achieve maximum resource utilization. Pressure tube heavy water reactors (PT-HWR) are highly advantageous for implementing the use of thorium-based fuels because of their high neutron economy and on-line re-fuelling capability. The use of heterogeneous seed-blanket core concepts in a PT-HWR where higher-fissile-content seed fuel bundles are physically separate from lower-fissile-content blanket bundles allows more flexibility and control in fuel management to maximize the fissile utilization and conversion of fertile fuel. The lattice concept chosen is a 35-element bundle made with a homogeneous mixture of reactor grade Pu and Th, and with a central zirconia rod to help reduce coolant void reactivity. Several annular heterogeneous seed-blanket core concepts with plutonium-thorium-based fuels in a 700-MWe-class PT-HWR were analyzed, using a once-through thorium (OTT) cycle. Different combinations of seed and blanket fuel were tested to determine the impact on core-average burnup, fissile utilization, power distributions, and other performance parameters. It was found that the various core concepts can achieve a fissile utilization that is up to 30% higher than is currently achieved in a PT-HWR using conventional natural uranium fuel bundles. Up to 67% of the Pu is consumed; up to 43% of the energy is produced from thorium, and up to 363 kg/year of U-233 is produced. Seed-blanket cores with ∼50% content of low-power blanket bundles may require power de-rating (∼58% to 65%) to avoid exceeding maximum limits for peak channel power, bundle power and linear element ratings. (authors)

  19. Core Research Center

    USGS Publications Warehouse

    Hicks, Joshua; Adrian, Betty

    2009-01-01

    The Core Research Center (CRC) of the U.S. Geological Survey (USGS), located at the Denver Federal Center in Lakewood, Colo., currently houses rock core from more than 8,500 boreholes representing about 1.7 million feet of rock core from 35 States and cuttings from 54,000 boreholes representing 238 million feet of drilling in 28 States. Although most of the boreholes are located in the Rocky Mountain region, the geologic and geographic diversity of samples have helped the CRC become one of the largest and most heavily used public core repositories in the United States. Many of the boreholes represented in the collection were drilled for energy and mineral exploration, and many of the cores and cuttings were donated to the CRC by private companies in these industries. Some cores and cuttings were collected by the USGS along with other government agencies. Approximately one-half of the cores are slabbed and photographed. More than 18,000 thin sections and a large volume of analytical data from the cores and cuttings are also accessible. A growing collection of digital images of the cores are also becoming available on the CRC Web site Internet http://geology.cr.usgs.gov/crc/.

  20. Core-Noise Research

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2012-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015 (N+1), 2020 (N+2), and 2025 (N+3) timeframes; SFW strategic thrusts and technical challenges; SFW advanced subsystems that are broadly applicable to N+3 vehicle concepts, with an indication where further noise research is needed; the components of core noise (compressor, combustor and turbine noise) and a rationale for NASA's current emphasis on the combustor-noise component; the increase in the relative importance of core noise due to turbofan design trends; the need to understand and mitigate core-noise sources for high-efficiency small gas generators; and the current research activities in the core-noise area, with additional details given about forthcoming updates to NASA's Aircraft Noise Prediction Program (ANOPP) core-noise prediction capabilities, two NRA efforts (Honeywell International, Phoenix, AZ and University of Illinois at Urbana-Champaign, respectively) to improve the understanding of core-noise sources and noise propagation through the engine core, and an effort to develop oxide/oxide ceramic-matrix-composite (CMC) liners for broadband noise attenuation suitable for turbofan-core application. Core noise must be addressed to ensure that the N+3 noise goals are met. Focused, but long-term, core-noise research is carried out to enable the advanced high-efficiency small gas-generator subsystem, common to several N+3 conceptual designs, needed to meet NASA's technical challenges. Intermediate updates to prediction tools are implemented as the understanding of the source structure and engine-internal propagation effects is improved. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The

  1. Laser anemometer measurements in an annular cascade of core turbine vanes and comparison with theory

    NASA Technical Reports Server (NTRS)

    Goldman, L. J.; Seashultz, R. G.

    1982-01-01

    Laser measurements were made in an annular cascade of stator vanes operating at an exit critical velocity ratio of 0.78. Velocity and flow angles in the blade to blade plane were obtained at every 10 percent of axial chord within the passage and at 1/2 axial chord downstream of the vanes for radial positions near the hub, mean and tip. Results are presented in both plot and tabulated form and are compared with calculations from an inviscid, quasi three dimensional computer program. The experimental measurements generally agreed well with these theoretical calculations, an indication of the usefulness of this analytic approach.

  2. Nonlinear stability of oscillatory core-annular flow: A generalized Kuramoto-Sivashinsky equation with time periodic coefficients

    NASA Technical Reports Server (NTRS)

    Coward, Adrian V.; Papageorgiou, Demetrios T.; Smyrlis, Yiorgos S.

    1994-01-01

    In this paper the nonlinear stability of two-phase core-annular flow in a pipe is examined when the acting pressure gradient is modulated by time harmonic oscillations and viscosity stratification and interfacial tension is present. An exact solution of the Navier-Stokes equations is used as the background state to develop an asymptotic theory valid for thin annular layers, which leads to a novel nonlinear evolution describing the spatio-temporal evolution of the interface. The evolution equation is an extension of the equation found for constant pressure gradients and generalizes the Kuramoto-Sivashinsky equation with dispersive effects found by Papageorgiou, Maldarelli & Rumschitzki, Phys. Fluids A 2(3), 1990, pp. 340-352, to a similar system with time periodic coefficients. The distinct regimes of slow and moderate flow are considered and the corresponding evolution is derived. Certain solutions are described analytically in the neighborhood of the first bifurcation point by use of multiple scales asymptotics. Extensive numerical experiments, using dynamical systems ideas, are carried out in order to evaluate the effect of the oscillatory pressure gradient on the solutions in the presence of a constant pressure gradient.

  3. Profiling of energy deposition fields in a modular HTHR with annular core: Computational/experimental studies at the ASTRA critical facility

    SciTech Connect

    Boyarinov, V. F.; Garin, V. P.; Glushkov, E. S.; Zimin, A. A.; Kompaniets, G. V.; Nevinitsa, V. A.; Polyakov, D. N.; Ponomarev, A. S.; Ponomarev-Stepnoi, N. N.; Smirnov, O. N.; Fomichenko, P. A.; Chunyaev, E. I.; Marova, E. V.; Sukharev, Yu. P.

    2010-12-15

    The paper presents the results obtained from the computational/experimental studies of the spatial distribution of the {sup 235}U fission reaction rate in a critical assembly with an annular core and poison profiling elements inserted into the inner graphite reflector. The computational analysis was carried out with the codes intended for design computation of an HTHR-type reactor.

  4. Laser anemometer measurements and computations in an annular cascade of high turning core turbine vanes

    NASA Technical Reports Server (NTRS)

    Goldman, Louis J.; Seasholtz, Richard G.

    1992-01-01

    An advanced laser anemometer (LA) was used to measure the axial and tangential velocity components in an annular cascade of turbine stator vanes designed for a high bypass ratio engine. These vanes were based on a redesign of the first-stage stator, of a two-stage turbine, that produced 75 degrees of flow turning. Tests were conducted on a 0.771 scale model of the engine size stator. The advanced LA fringe system was designed to employ thinner than usual laser beams resulting in a 50-micron-diameter probe volume. Window correction optics were used to ensure that the laser beams did not uncross in passing through the curved optical access port. Experimental LA measurements of velocity and turbulence were obtained both upstream, within, and downstream of the stator vane row at the design exit critical velocity ratio of 0.896 at the hub. Static pressures were also measured on the vane surface. The measurements are compared, where possible with calculations from a 3-D inviscid flow analysis. The data are presented in both graphic and tabulated form so that they may be readily used to compare against other turbomachinery computations.

  5. Experimental research on secondary flows in annular turbine cascades at the Von Karman Institute

    NASA Astrophysics Data System (ADS)

    Boletis, E.

    Investigations of secondary flows in isolated annular cascades with collateral inlet boundary layers; in an annular turbine nozzle guide vane followed by a rotating blade row; in isolated annular cascades with skewed inlet boundary layers; and in a turbine stator preceded by a full stage are summarized. Secondary flow patterns in annular configurations, e.g., the mutual interference of the passage vortices and the radial pressure gradient, the radial migration of low momentum material, effects of tip contouring inlet skew are studied. Differences between the flow field in annular and straight cascades can be derived from comparison with other test results.

  6. The axisymmetric long-wave interfacial stability of core-annular flow of power-law fluid with surfactant

    NASA Astrophysics Data System (ADS)

    Sun, Xue-Wei; Peng, Jie; Zhu, Ke-Qin

    2012-02-01

    The long wave stability of core-annular flow of power-law fluids with an axial pressure gradient is investigated at low Reynolds number. The interface between the two fluids is populated with an insoluble surfactant. The analytic solution for the growth rate of perturbation is obtained with long wave approximation. We are mainly concerned with the effects of shear-thinning/thickening property and interfacial surfactant on the flow stability. The results show that the influence of shear-thinning/thickening property accounts to the change of the capillary number. For a clean interface, the shear-thinning property enhances the capillary instability when the interface is close to the pipe wall. The converse is true when the interface is close to the pipe centerline. For shear-thickening fluids, the situation is reversed. When the interface is close to the pipe centerline, the capillary instability can be restrained due to the influence of surfactant. A parameter set can be found under which the flow is linearly stable.

  7. Proposed Design and Operation of a Heat Pipe Reactor using the Sandia National Laboratories Annular Core Test Facility and Existing UZrH Fuel Pins

    NASA Astrophysics Data System (ADS)

    Wright, Steven A.; Lipinski, Ronald J.; Pandya, Tara; Peters, Curtis

    2005-02-01

    Heat Pipe Reactors (HPR) for space power conversion systems offer a number of advantages not easily provided by other systems. They require no pumping, their design easily deals with freezing and thawing of the liquid metal, and they can provide substantial levels of redundancy. Nevertheless, no reactor has ever been operated and cooled with heat pipes, and the startup and other operational characteristics of these systems remain largely unknown. Signification deviations from normal reactor heat removal mechanisms exist, because the heat pipes have fundamental heat removal limits due to sonic flow issues at low temperatures. This paper proposes an early prototypic test of a Heat Pipe Reactor (using existing 20% enriched nuclear fuel pins) to determine the operational characteristics of the HPR. The proposed design is similar in design to the HOMER and SAFE-300 HPR designs (Elliot, Lipinski, and Poston, 2003; Houts, et. al, 2003). However, this reactor uses existing UZrH fuel pins that are coupled to potassium heat pipes modules. The prototype reactor would be located in the Sandia Annular Core Research Reactor Facility where the fuel pins currently reside. The proposed reactor would use the heat pipes to transport the heat from the UZrH fuel pins to a water pool above the core, and the heat transport to the water pool would be controlled by adjusting the pressure and gas type within a small annulus around each heat pipe. The reactor would operate as a self-critical assembly at power levels up to 200 kWth. Because the nuclear heated HPR test uses existing fuel and because it would be performed in an existing facility with the appropriate safety authorization basis, the test could be performed rapidly and inexpensively. This approach makes it possible to validate the operation of a HPR and also measure the feedback mechanisms for a typical HPR design. A test of this nature would be the world's first operating Heat Pipe Reactor. This reactor is therefore called "HPR-1".

  8. Three component laser anemometer measurements in an annular cascade of core turbine vanes with contoured end wall

    NASA Technical Reports Server (NTRS)

    Goldman, Louis J.; Seasholtz, Richard G.

    1988-01-01

    The three mean velocity components were measured in a full-scale annular turbine stator cascade with contoured hub end wall using a newly developed laser anemometer system. The anemometer consists of a standard fringe configuration using fluorescent seed particles to measure the axial and tangential components. The radial component is measured with a scanning confocal Fabry-Perot interferometer. These two configurations are combined in a single optical system that can operate simultaneously in a backscatter mode through a single optical access port. Experimental measurements were obtained both within and downstream of the stator vane row and compared with calculations from a three-dimensional inviscid computer program. In addition, detailed calibration procedures are described that were used, prior to the experiment, to accurately determine the laser beam probe volume location relative to the cascade hardware.

  9. Behavior of an heterogeneous annular FBR core during an unprotected loss of flow accident: Analysis of the primary phase with SAS-SFR

    SciTech Connect

    Massara, S.; Schmitt, D.; Bretault, A.; Lemasson, D.; Darmet, G.; Verwaerde, D.; Struwe, D.; Pfrang, W.; Ponomarev, A.

    2012-07-01

    In the framework of a substantial improvement on FBR core safety connected to the development of a new Gen IV reactor type, heterogeneous core with innovative features are being carefully analyzed in France since 2009. At EDF R and D, the main goal is to understand whether a strong reduction of the Na-void worth - possibly attempting a negative value - allows a significant improvement of the core behavior during an unprotected loss of flow accident. Also, the physical behavior of such a core is of interest, before and beyond the (possible) onset of Na boiling. Hence, a cutting-edge heterogeneous design, featuring an annular shape, a Na-plena with a B{sub 4}C plate and a stepwise modulation of fissile core heights, was developed at EDF by means of the SDDS methodology, with a total Na-void worth of -1 $. The behavior of such a core during the primary phase of a severe accident, initiated by an unprotected loss of flow, is analyzed by means of the SAS-SFR code. This study is carried-out at KIT and EDF, in the framework of a scientific collaboration on innovative FBR severe accident analyses. The results show that the reduction of the Na-void worth is very effective, but is not sufficient alone to avoid Na-boiling and, hence, to prevent the core from entering into the primary phase of a severe accident. Nevertheless, the grace time up to boiling onset is greatly enhanced in comparison to a more traditional homogeneous core design, and only an extremely low fraction of the fuel (<0.1%) enters into melting at the end of this phase. A sensitivity analysis shows that, due to the inherent neutronic characteristics of such a core, the gagging scheme plays a major role on the core behavior: indeed, an improved 4-zones gagging scheme, associated with an enhanced control rod drive line expansion feed-back effect, finally prevents the core from entering into sodium boiling. This major conclusion highlights both the progress already accomplished and the need for more detailed

  10. [Granuloma annulare].

    PubMed

    Butsch, F; Weidenthaler-Barth, B; von Stebut, E

    2015-11-01

    Granuloma annulare is a benign, chronic inflammatory skin disease. Its pathogenesis is still unclear, but reports on infections as a trigger can be found. In addition, some authors reported an association with other systemic disease, e.g., cancer, trauma, and diabetes mellitus; however, these have not been verified. The clinical picture of granuloma annulare ranges from the localized form predominantly at the extremities to disseminated, subcutaneous, or perforating forms. Diagnosis is based on the typical clinical presentation which may be confirmed by a biopsy. Histologically, necrobiotic areas within granulomatous inflammation are typical. The prognosis of the disease is good with spontaneous resolution being frequently observed, especially in localized forms. Disseminated manifestations tend to persist longer, and recurrences are reported. When choosing between different therapeutic options, the benign disease character versus the individual degree of suffering and the potential therapy side effects must be considered. For local treatment, topical application of corticosteroids is most common. Disseminated forms can be treated systemically with corticosteroids for several weeks; alternatively, dapsone, hydroxychloroquine, retinoids, fumaric acid, cyclosporine, and anti-TNFα appear to be effective. PMID:26487494

  11. Core questions in domestication research.

    PubMed

    Zeder, Melinda A

    2015-03-17

    The domestication of plants and animals is a key transition in human history, and its profound and continuing impacts are the focus of a broad range of transdisciplinary research spanning the physical, biological, and social sciences. Three central aspects of domestication that cut across and unify this diverse array of research perspectives are addressed here. Domestication is defined as a distinctive coevolutionary, mutualistic relationship between domesticator and domesticate and distinguished from related but ultimately different processes of resource management and agriculture. The relative utility of genetic, phenotypic, plastic, and contextual markers of evolving domesticatory relationships is discussed. Causal factors are considered, and two leading explanatory frameworks for initial domestication of plants and animals, one grounded in optimal foraging theory and the other in niche-construction theory, are compared.

  12. Core Research Program, Year 5

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Dramatic losses of bone mineral density (BMD) and muscle strength are two of the best documented changes observed in humans after prolonged exposure to microgravity. Recovery of muscle upon return to a 1-G environment is well studied, however, far less is known about the rate and completeness of BMD recovery to pre-flight values. Using the mature tail-suspended adult rat model, this proposal will focus on the temporal course of recovery in tibial bone following a 28-d period of skeletal unloading. Through the study of bone density and muscle strength in the same animal, time-points during recovery from simulated microgravity will be identified when bone is at an elevated risk for fracture. These will occur due to the rapid recovery of muscle strength coupled with a slower recovery of bone, producing a significant mismatch in functional strength of these two tissues. Once the time-point of maximal mismatch is defined, various mechanical and pharmacological interventions will be tested at and around this time-point in attempt to minimize the functional difference of bone and muscle. The outcomes of this research will have high relevance for optimizing the rehabilitation of astronauts upon return to Earth, as well as upon landing on the Martian surface before assuming arduous physical tasks. Further. it will impact significantly on rehabilitation issues common to patients experiencing long periods of limb immobilization or bed rest.

  13. Nuclear gas core propulsion research program

    NASA Technical Reports Server (NTRS)

    Diaz, Nils J.; Dugan, Edward T.; Anghaie, Samim

    1993-01-01

    Viewgraphs on the nuclear gas core propulsion research program are presented. The objectives of this research are to develop models and experiments, systems, and fuel elements for advanced nuclear thermal propulsion rockets. The fuel elements under investigation are suitable for gas/vapor and multiphase fuel reactors. Topics covered include advanced nuclear propulsion studies, nuclear vapor thermal rocket (NVTR) studies, and ultrahigh temperature nuclear fuels and materials studies.

  14. Inverted annular flow experimental study

    SciTech Connect

    De Jarlais, G.; Ishii, M.

    1985-04-01

    Steady-state inverted annular flow of Freon 113 in up flow was established in a transparent test section. Using a special inlet configuration consisting of long aspect-ratio liquid nozzles coaxially centered within a heated quartz tube, idealized inverted annular flow initial geometry (cylindrical liquid core surrounded by coaxial annulus of gas) could be established. Inlet liquid and gas flowrates, liquid subcooling, and gas density (using various gas species) were measured and varied systematically. The hydrodynamic behavior of the liquid core, and the subsequent downstream break-up of this core into slugs, ligaments and/or droplets of various sizes, was observed. In general, for low inlet liquid velocities it was observed that after the initial formation of roll waves on the liquid core surface, an agitated region of high surface area, with attendant high momentum and energy transfers, occurs. This agitated region appears to propagate downsteam in a quasi-periodic pattern. Increased inlet liquid flow rates, and high gas annulus flow rates tend to diminish the significance of this agitated region. Observed inverted annular flow (and subsequent downstream flow pattern) hydrodynamic behavior is reported, and comparisons are drawn to data generated by previous experimenters studying post-CHF flow.

  15. Liquid Annular Seal Research

    NASA Technical Reports Server (NTRS)

    Palazzolo, Alan B.; Venkataraman, Balaji; Padavala, Sathya S.; Ryan, Steve; Vallely, Pat; Funston, Kerry

    1996-01-01

    This paper highlights the accomplishments on a joint effort between NASA - Marshall Space Flight Center and Texas A and M University to develop accurate seal analysis software for use in rocket turbopump design, design audits and trouble shooting. Results for arbitrary clearance profile, transient simulation, thermal effects solution and flexible seal wall model are presented. A new solution for eccentric seals based on cubic spline interpolation and ordinary differential equation integration is also presented.

  16. Future Directions for Research on Core Competencies

    ERIC Educational Resources Information Center

    Bradshaw, Catherine P.; Guerra, Nancy G.

    2008-01-01

    This concluding commentary highlights common themes that emerged across the chapters in this volume. We identify strengths and limitations of the core competencies framework and discuss the importance of context, culture, and development for understanding the role of the core competencies in preventing risk behavior in adolescence. We also outline…

  17. Research Perspectives on Core French: A Literature Review

    ERIC Educational Resources Information Center

    Lapkin, Sharon; Mady, Callie; Arnott, Stephanie

    2009-01-01

    This article reviews the research literature on core French in three main areas: student diversity, delivery models for the core French program, and instructional approaches. These topics are put into context through a discussion of studies on community attitudes to French as a second language (FSL), dissatisfaction with core French outcomes and…

  18. A framework for managing core facilities within the research enterprise.

    PubMed

    Haley, Rand

    2009-09-01

    Core facilities represent increasingly important operational and strategic components of institutions' research enterprises, especially in biomolecular science and engineering disciplines. With this realization, many research institutions are placing more attention on effectively managing core facilities within the research enterprise. A framework is presented for organizing the questions, challenges, and opportunities facing core facilities and the academic units and institutions in which they operate. This framework is intended to assist in guiding core facility management discussions in the context of a portfolio of facilities and within the overall institutional research enterprise.

  19. Advanced Materials and Solids Analysis Research Core (AMSARC)

    EPA Science Inventory

    The Advanced Materials and Solids Analysis Research Core (AMSARC), centered at the U.S. Environmental Protection Agency's (EPA) Andrew W. Breidenbach Environmental Research Center in Cincinnati, Ohio, is the foundation for the Agency's solids and surfaces analysis capabilities. ...

  20. Annular pancreas (image)

    MedlinePlus

    Annular pancreas is an abnormal ring or collar of pancreatic tissue that encircles the duodenum (the part of the ... intestine that connects to stomach). This portion of pancreas can constrict the duodenum and block or impair ...

  1. Mechanically expandable annular seal

    DOEpatents

    Gilmore, Richard F.

    1983-01-01

    A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluidtight barrier. A counterrotation removes the barrier.

  2. Mechanically expandable annular seal

    DOEpatents

    Gilmore, R.F.

    1983-07-19

    A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces is described. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluid tight barrier. A counter rotation removes the barrier. 6 figs.

  3. Partial annular pancreas

    PubMed Central

    Jindal, Gunjan; Mittal, Amit; Singal, Rikki; Singal, Samita

    2016-01-01

    Annular pancreas is a developmental anomaly that can be associated with other conditions such as Down syndrome, duodenal atresia, and Hirschsprung disease. A band of pancreatic tissue, in continuity with the pancreatic head, completely or incompletely encircles the descending duodenum, sometimes assuming a “crocodile jaw” configuration. We present the case of an adult who presented with epigastric pain and vomiting and was found to have annular pancreas. PMID:27695176

  4. Partial annular pancreas

    PubMed Central

    Jindal, Gunjan; Mittal, Amit; Singal, Rikki; Singal, Samita

    2016-01-01

    Annular pancreas is a developmental anomaly that can be associated with other conditions such as Down syndrome, duodenal atresia, and Hirschsprung disease. A band of pancreatic tissue, in continuity with the pancreatic head, completely or incompletely encircles the descending duodenum, sometimes assuming a “crocodile jaw” configuration. We present the case of an adult who presented with epigastric pain and vomiting and was found to have annular pancreas.

  5. Profiling the EG Research Community and Its Core

    NASA Astrophysics Data System (ADS)

    Scholl, Hans J. (Jochen)

    Electronic Government Research (EGR) has progressed beyond its stages of infancy and has unfolded into a respected domain of multi- and cross-disciplinary study. A sizable and dedicated community of researchers has formed. So far, however, few, if any, accounts exist which sufficiently analyze the profile of the electronic government research community. The contribution of this paper is to describe this profile and give a detailed account of the core researcher community, name the most prolific researchers, determine their disciplinary backgrounds, and identify their preferred standards of inquiry. The study also identifies and quantifies the preferred publishing outlets in EGR, distinguishing between core journals and core conferences, on the one hand, and non-core sites, on the other hand. This study advances the understanding of the emerging structure and profile of the academic domain of EGR and helps researchers identify adequate publishing outlets for their domain-related research.

  6. LacCore: Support for the terrestrial sediment core research community

    NASA Astrophysics Data System (ADS)

    Brady, K. L.; Noren, A. J.; Myrbo, A.; Ito, E.

    2009-12-01

    LacCore, the National Lacustrine Core Facility, has been funded by the US National Science Foundation and the University of Minnesota for the past decade as a public facility to support the terrestrial sediment core research community. LacCore provides free or low-cost access to an array of expensive equipment and instrumentation in the field and lab, training for a variety of procedures, and core and data curation. The user base has increased from perhaps 20 users and a handful of projects in the first year to 621 users and 250 projects in 2008. The community served is diverse, with topics including invasive species, eutrophication, salinization, tectonics, geomicrobiology, evolutionary biology, isostatic rebound, stream bank erosion, glaciology, hydrogeology, atmospheric chemistry, carbon cycling, and rock magnetics, as well as paleoenvironment and paleoclimate. The changing needs of projects drive innovation in procedures and equipment, all of which become available to subsequent researchers. Among the newest additions to the lab is a benchtop scanning electron microscope with electron-dispersive x-ray spectrometry (SEM-EDX or -EDS) capability for sediment characterization. This instrument allows rapid imaging of sedimentary components and determination of their elemental composition without substantial sample preparation, lead time, or user training. These images and data augment the initial core description process, filling a void between existing smear slide and scanning micro XRF capabilities.

  7. Research turbine for high-temperature core engine application. 2: Effect of rotor tip clearance on overall performance

    NASA Technical Reports Server (NTRS)

    Szanca, E. M.; Behning, F. P.; Schum, H. J.

    1974-01-01

    A 25.4-cm (10-in) tip diameter turbine was tested to determine the effect of rotor radial tip clearance on turbine overall performance. The test turbine was a half-scale model of a 50.8-cm-(20-in.-) diameter research turbine designed for high-temperature core engine application. The test turbine was fabricated with solid vanes and blades with no provision for cooling air and tested at much reduced inlet conditions. The tests were run at design speed over a range of pressure ratios for three different rotor clearances ranging from 2.3 to 6.7 percent of the annular blade passage height. The results obtained are compared to the results obtained with three other turbines of varying amounts of reaction.

  8. Segmented annular combustor

    DOEpatents

    Reider, Samuel B.

    1979-01-01

    An industrial gas turbine engine includes an inclined annular combustor made up of a plurality of support segments each including inner and outer walls of trapezoidally configured planar configuration extents and including side flanges thereon interconnected by means of air cooled connector bolt assemblies to form a continuous annular combustion chamber therebetween and wherein an air fuel mixing chamber is formed at one end of the support segments including means for directing and mixing fuel within a plenum and a perforated header plate for directing streams of air and fuel mixture into the combustion chamber; each of the outer and inner walls of each of the support segments having a ribbed lattice with tracks slidably supporting porous laminated replaceable panels and including pores therein for distributing combustion air into the combustion chamber while cooling the inner surface of each of the panels by transpiration cooling thereof.

  9. Biospecimen Core Resource - Office of Cancer Clinical Proteomics Research

    Cancer.gov

    The purpose of this notice is to notify the community that the National Cancer Institute's (NCI’s) Office of Cancer Clinical Proteomics Research (OCCPR) is seeking sources to establish a Biospecimen Core Resource (BCR), capable of receiving, qualifying, processing, and distributing annotated biospecimens.

  10. Research core drilling in the Manson impact structure, Iowa

    NASA Technical Reports Server (NTRS)

    Anderson, R. R.; Hartung, J. B.; Roddy, D. J.; Shoemaker, E. M.

    1992-01-01

    The Manson impact structure (MIS) has a diameter of 35 km and is the largest confirmed impact structure in the United States. The MIS has yielded a Ar-40/Ar-39 age of 65.7 Ma on microcline from its central peak, an age that is indistinguishable from the age of the Cretaceous-Tertiary boundary. In the summer of 1991 the Iowa Geological Survey Bureau and U.S. Geological Survey initiated a research core drilling project on the MIS. The first core was beneath 55 m of glacial drift. The core penetrated a 6-m layered sequence of shale and siltstone and 42 m of Cretaceous shale-dominated sedimentary clast breccia. Below this breccia, the core encountered two crystalline rock clast breccia units. The upper unit is 53 m thick, with a glassy matrix displaying various degrees of devitrification. The upper half of this unit is dominated by the glassy matrix, with shock-deformed mineral grains (especially quartz) the most common clast. The glassy-matrix unit grades downward into the basal unit in the core, a crystalline rock breccia with a sandy matrix, the matrix dominated by igneous and metamorphic rock fragments or disaggregated grains from those rocks. The unit is about 45 m thick, and grains display abundant shock deformation features. Preliminary interpretations suggest that the crystalline rock breccias are the transient crater floor, lifted up with the central peak. The sedimentary clast breccia probably represents a postimpact debris flow from the crater rim, and the uppermost layered unit probably represents a large block associated with the flow. The second core (M-2) was drilled near the center of the crater moat in an area where an early crater model suggested the presence of postimpact lake sediments. The core encountered 39 m of sedimentary clast breccia, similar to that in the M-1 core. Beneath the breccia, 120 m of poorly consolidated, mildly deformed, and sheared siltstone, shale, and sandstone was encountered. The basal unit in the core was another sequence

  11. Annular recuperator design

    DOEpatents

    Kang, Yungmo

    2005-10-04

    An annular heat recuperator is formed with alternating hot and cold cells to separate counter-flowing hot and cold fluid streams. Each cold cell has a fluid inlet formed in the inner diameter of the recuperator near one axial end, and a fluid outlet formed in the outer diameter of the recuperator near the other axial end to evenly distribute fluid mass flow throughout the cell. Cold cells may be joined with the outlet of one cell fluidly connected to the inlet of an adjacent downstream cell to form multi-stage cells.

  12. Topological suppression of optical tunneling in a twisted annular fiber

    SciTech Connect

    Ornigotti, M.; Valle, G. Della; Gatti, D.; Longhi, S.

    2007-08-15

    A classical wave-optics analog of topological (Aharonov-Bohm) suppression of tunneling in a double-well potential on a ring threaded by a magnetic flux is proposed. The optical system consists of a uniformly twisted optical fiber with a structured annular core, in which the fiber twist mimics the role of the magnetic flux in the corresponding quantum-mechanical problem. Light waves trapped in the annular core of the fiber experience an additional topological (Aharonov-Bohm) phase, which may lead to the destruction of optical tunneling at certain values of the twist rate.

  13. Azimuthally forced flames in an annular combustor

    NASA Astrophysics Data System (ADS)

    Worth, Nicholas; Dawson, James; Mastorakos, Epaminondas

    2015-11-01

    Thermoacoustic instabilities are more likely to occur in lean burn combustion systems, making their adoption both difficult and costly. At present, our knowledge of such phenomena is insufficient to produce an inherently stable combustor by design, and therefore an improved understanding of these instabilities has become the focus of a significant research effort. Recent experimental and numerical studies have demonstrated that the symmetry of annular chambers permit a range of self-excited azimuthal modes to be generated in annular geometry, which can make the study of isolated modes difficult. While acoustic forcing is common in single flame experiments, no equivalent for forced azimuthal modes in an annular chamber have been demonstrated. The present investigation focuses on the novel application of acoustic forcing to a laboratory scale annular combustor, in order to generate azimuthal standing wave modes at a prescribed frequency and amplitude. The results focus on the ability of the method to isolate the mode of oscillation using experimental pressure and high speed OH* measurements. The successful excitation of azimuthal modes demonstrated represents an important step towards improving our fundamental understanding of this phenomena in practically relevant geometry.

  14. Portal Annular Pancreas

    PubMed Central

    Harnoss, Jonathan M.; Harnoss, Julian C.; Diener, Markus K.; Contin, Pietro; Ulrich, Alexis B.; Büchler, Markus W.; Schmitz-Winnenthal, Friedrich H.

    2014-01-01

    Abstract Portal annular pancreas (PAP) is an asymptomatic congenital pancreas anomaly, in which portal and/or mesenteric veins are encased by pancreas tissue. The aim of the study was to determine the role of PAP in pancreatic surgery as well as its management and potential complication, specifically, postoperative pancreatic fistula (POPF). On the basis of a case report, the MEDLINE and ISI Web of Science databases were systematically reviewed up to September 2012. All articles describing a case of PAP were considered. In summary, 21 studies with 59 cases were included. The overall prevalence of PAP was 2.4% and the patients' mean (SD) age was 55.9 (16.2) years. The POPF rate in patients with PAP (12 pancreaticoduodenectomies and 3 distal pancreatectomies) was 46.7% (in accordance with the definition of the International Study Group of Pancreatic Surgery). Portal annular pancreas is a quite unattended pancreatic variant with high prevalence and therefore still remains a clinical challenge to avoid postoperative complications. To decrease the risk for POPF, attentive preoperative diagnostics should also focus on PAP. In pancreaticoduodenectomy, a shift of the resection plane to the pancreas tail should be considered; in extensive pancreatectomy, coverage of the pancreatic remnant by the falciform ligament could be a treatment option. PMID:25207658

  15. Axisymmetric annular curtain stability

    NASA Astrophysics Data System (ADS)

    Ahmed, Zahir U.; Khayat, Roger E.; Maissa, Philippe; Mathis, Christian

    2012-06-01

    A temporal stability analysis was carried out to investigate the stability of an axially moving viscous annular liquid jet subject to axisymmetric disturbances in surrounding co-flowing viscous gas media. We investigated in this study the effects of inertia, surface tension, the gas-to-liquid density ratio, the inner-to-outer radius ratio and the gas-to-liquid viscosity ratio on the stability of the jet. With an increase in inertia, the growth rate of the unstable disturbances is found to increase. The dominant (or most unstable) wavenumber decreases with increasing Reynolds number for larger values of the gas-to-liquid viscosity ratio. However, an opposite tendency for the most unstable wavenumber is predicted for small viscosity ratio in the same inertia range. The surrounding gas density, in the presence of viscosity, always reduces the growth rate, hence stabilizing the flow. There exists a critical value of the density ratio above which the flow becomes stable for very small viscosity ratio, whereas for large viscosity ratio, no stable flow appears in the same range of the density ratio. The curvature has a significant destabilizing effect on the thin annular jet, whereas for a relatively thick jet, the maximum growth rate decreases as the inner radius increases, irrespective of the surrounding gas viscosity. The degree of instability increases with Weber number for a relatively large viscosity ratio. In contrast, for small viscosity ratio, the growth rate exhibits a dramatic dependence on the surface tension. There is a small Weber number range, which depends on the viscosity ratio, where the flow is stable. The viscosity ratio always stabilizes the flow. However, the dominant wavenumber increases with increasing viscosity ratio. The range of unstable wavenumbers is affected only by the curvature effect.

  16. Cretaceous shallow drilling, US Western Interior: Core research

    SciTech Connect

    Arthur, M.A.

    1993-02-17

    This project is a continuing multidisciplinary study of middle to Upper Cretaceous marine carbonate and clastic rocks in the Utah-Colorado-Kansas corridor of the old Cretaceous seaway that extended from the Gulf Coast to the Arctic during maximum Cretaceous transgressions. It is collaborative between in the US Geological Survey (W.E. Dean, P.I.) and University researchers led by The Pennsylvania State University(M.A. Arthur, P.I.) and funded by DOE and the USGS, in part. Research focusses on the Greenhom, Niobrara and lower Pierre Shale units and their equivalents, combining biostratigraphic/paleoecologic studies, inorganic, organic and stable isotopic geochemical studies, mineralogical investigations and high-resolution geophysical logging. This research requires unweathered samples and continuous smooth exposures'' in the form of cores from at least 4 relatively shallow reference holes (i.e. < 1000m) in transect from east to west across the basin. The major initial effort was recovery in Year 1 of the project of continuous cores from each site in the transect. This drilling provided samples and logs of strata ranging from pelagic sequences that contain organic-carbon-rich marine source rocks to nearshore coal-bearing units. This transect also will provide information on the extent of thermal maturation and migration of hydrocarbons in organic-carbon-rich strata along a burial gradient.

  17. Core conversion of the Portuguese research reactor to LEU fuel

    SciTech Connect

    Marques, J.G.; Ramos, A.R.; Kocher, A.

    2008-07-15

    Core conversion of the Portuguese Research Reactor (RPI) to LEU fuel is being performed within IAEA's Technical Cooperation project POR/4/016, with financial support from the US and Portugal. CERCA was selected as manufacturer of the LEU assemblies by the IAEA after an international call for bids. CERCA provided a comprehensive package to the RPI which included the mechanical verification of the design of the assemblies, their manufacture and arrangements for a joint inspection of the finished assemblies. The LEU fuel assemblies were manufactured within 8 months upon final approval of the design. The safety analyses for the core conversion to LEU fuel were made with the assistance of the RERTR program and were submitted for review by the IAEA and by Portuguese authorities in January 2007. Revised documents were submitted in June 2007 addressing the issues raised during review. Regulatory approval was received in early August and core conversion was done in early September. All measured safety parameters are within the defined acceptance limits. Operation at full power is expected by the end of October. (author)

  18. Manufacture of annular cermet articles

    DOEpatents

    Forsberg, Charles W.; Sikka, Vinod K.

    2004-11-02

    A method to produce annular-shaped, metal-clad cermet components directly produces the form and avoids multiple fabrication steps such as rolling and welding. The method includes the steps of: providing an annular hollow form with inner and outer side walls; filling the form with a particulate mixture of ceramic and metal; closing, evacuating, and hermetically sealing the form; heating the form to an appropriate temperature; and applying force to consolidate the particulate mixture into solid cermet.

  19. Message Variability and Heterogeneity: A Core Challenge for Communication Research

    PubMed Central

    Slater, Michael D.; Peter, Jochen; Valkenberg, Patti

    2015-01-01

    Messages are central to human social experience, and pose key conceptual and methodological challenges in the study of communication. In response to these challenges, we outline a systematic approach to conceptualizing, operationalizing, and analyzing messages. At the conceptual level, we distinguish between two core aspects of messages: message variability (the defined and operationalized features of messages) and message heterogeneity (the undefined and unmeasured features of messages), and suggest preferred approaches to defining message variables. At the operational level, we identify message sampling, selection, and research design strategies responsive to issues of message variability and heterogeneity in experimental and survey research. At the analytical level, we highlight effective techniques to deal with message variability and heterogeneity. We conclude with seven recommendations to increase rigor in the study of communication through appropriately addressing the challenges presented by messages. PMID:26681816

  20. The Core Analytics of Randomized Experiments for Social Research. MDRC Working Papers on Research Methodology

    ERIC Educational Resources Information Center

    Bloom, Howard S.

    2006-01-01

    This chapter examines the core analytic elements of randomized experiments for social research. Its goal is to provide a compact discussion for faculty members, graduate students, and applied researchers of the design and analysis of randomized experiments for measuring the impacts of social or educational interventions. Design issues considered…

  1. Research in Librarianship: An Analysis of Research Articles in Core Library Journals of 1980.

    ERIC Educational Resources Information Center

    Nour, Martyvonne Morton

    A total of 343 research articles published in 41 core library journals in 1980 and a further 708 articles cited in a stratified random sample of 100 of the original (source) articles were examined in terms of subject, research methodology, and number of references. Findings were also compared with those of similar studies. It was found that: (1)…

  2. Film cooling research on the endwall of a turbine nozzle guide vane in a short duration annular cascade. II - Analysis and correlation of results

    NASA Astrophysics Data System (ADS)

    Harasgama, S. P.; Burton, C. D.

    1991-06-01

    Measurements of the heat transfer characteristics of the film cooled endwall (platform) of a turbine nozzle guide vane in an annular cascade at engine representative conditions are analyzed. The experimental results are well represented by the superposition theory of film cooling. It is shown that high cooling effectiveness can be achieved when the data are corrected for axial pressure gradients. The data are correlated against both the slot-wall jet parameter and the discrete hole injection function for flat-plate, zero pressure gradient cases. The pressure gradient correction brings the data to within +/- 11 percent of the discrete hole correlation.

  3. Dual annular rotating "windowed" nuclear reflector reactor control system

    DOEpatents

    Jacox, Michael G.; Drexler, Robert L.; Hunt, Robert N. M.; Lake, James A.

    1994-01-01

    A nuclear reactor control system is provided in a nuclear reactor having a core operating in the fast neutron energy spectrum where criticality control is achieved by neutron leakage. The control system includes dual annular, rotatable reflector rings. There are two reflector rings: an inner reflector ring and an outer reflector ring. The reflectors are concentrically assembled, surround the reactor core, and each reflector ring includes a plurality of openings. The openings in each ring are capable of being aligned or non-aligned with each other. Independent driving means for each of the annular reflector rings is provided so that reactor criticality can be initiated and controlled by rotation of either reflector ring such that the extent of alignment of the openings in each ring controls the reflection of neutrons from the core.

  4. Snapping annular ligament of the elbow joint in the throwing arms of young brothers.

    PubMed

    Aoki, Mitsuhiro; Okamura, Kenji; Yamashita, Toshihiko

    2003-10-01

    We examined young brothers with symptomatic snapping elbow in the throwing arm. Arthroscopic examination confirmed the mechanism of snapping, in which loose and protruded annular ligament-like tissue covered the volar half of the radial head in elbow extension and uncovered the radial head in deep elbow flexion. Arthroscopic resection of the annular ligament-like tissue was performed in one brother. Histologic examination of the removed tissue showed degenerated ligament tissue. Excision of loose annular ligament abolished snapping. Contralateral elbows of the brothers also showed similar asymptomatic snapping. Researchers suggest that a hereditary factor contributing to loose annular ligament and repetitive microtrauma from throwing is the cause of symptoms.

  5. Annular Eclipse as Seen by Hinode

    NASA Video Gallery

    This timelapse shows an annular eclipse as seen by JAXA's Hinode satellite on Jan. 4, 2011. An annular eclipse occurs when the moon, slightly more distant from Earth than on average, moves directly...

  6. Eosinophilic annular erythema in childhood - Case report*

    PubMed Central

    Abarzúa, Alvaro; Giesen, Laura; Silva, Sergio; González, Sergio

    2016-01-01

    Eosinophilic annular erythema is a rare, benign, recurrent disease, clinically characterized by persistent, annular, erythematous lesions, revealing histopathologically perivascular infiltrates with abundant eosinophils. This report describes an unusual case of eosinophilic annular erythema in a 3-year-old female, requiring sustained doses of hydroxychloroquine to be adequately controlled. PMID:27579748

  7. Eosinophilic annular erythema in childhood - Case report.

    PubMed

    Abarzúa, Alvaro; Giesen, Laura; Silva, Sergio; González, Sergio

    2016-01-01

    Eosinophilic annular erythema is a rare, benign, recurrent disease, clinically characterized by persistent, annular, erythematous lesions, revealing histopathologically perivascular infiltrates with abundant eosinophils. This report describes an unusual case of eosinophilic annular erythema in a 3-year-old female, requiring sustained doses of hydroxychloroquine to be adequately controlled. PMID:27579748

  8. Psoriatic Arthritis with Annular Pustular Psoriasis.

    PubMed

    Nagafuchi, Hiroko; Watanabe, Kyoko; Mikage, Hidenori; Ozaki, Shoichi

    2016-01-01

    We herein present the case of a 56-year-old woman who presented with symptoms of psoriatic arthritis (PsA) with erythema that progressed to annular pustular psoriasis. The patient had a 15-year history of polyarthritis. Annular pustular psoriasis is not typically observed in cases of arthritis. This is the first reported case of PsA with annular pustular psoriasis.

  9. Relating Policy to Research and Practice: The Common Core Standards

    ERIC Educational Resources Information Center

    Bomer, Randy; Maloch, Beth

    2011-01-01

    Randy Bomer and Beth Maloch take a look at the Common Core Standards and the ways they are presently shaping the curriculum offered to young children in school. They suggest that the Common Core Standards in early literacy and early childhood classrooms represents a restricted image of college or academic literacy. Mainly, the standards' authors…

  10. The liquid annular reactor system (LARS) propulsion

    SciTech Connect

    Maise, G.; Lazareth, O.W.; Horn, F.; Powell, J.R.; Ludewig, H. ); Lenard, R.X. )

    1991-01-05

    A new concept for very high specific impulse ({gt}2000 seconds) direct nuclear propulsion is described. The concept, termed LARS (Liquid Annular Reactor System) uses liquid nuclear fuel elements to heat hydrogen propellant to very high temperatures ({similar to}6000 K). Operating pressure is moderate ({similar to}10 atm), with the result that the outlet hydrogen is virtually 100% dissociated to monatomic H. The molten fuel is contained in a solid container of its own material, which is rotated to stabilize the liquid layer by centripetal force. LARS reactor designs are described, together with neutronic and thermal-hydraulic analyses. Power levels are on the order of 200 megawatts. Typically, LARS designs use 7 rotating fuel elements, are beryllium moderated and have critical radii of {similar to}100 cm (core L/D{approx}1.5).

  11. The Liquid Annular Reactor System (LARS) propulsion

    NASA Technical Reports Server (NTRS)

    Powell, James; Ludewig, Hans; Horn, Frederick; Lenard, Roger

    1990-01-01

    A concept for very high specific impulse (greater than 2000 seconds) direct nuclear propulsion is described. The concept, termed the liquid annular reactor system (LARS), uses liquid nuclear fuel elements to heat hydrogen propellant to very high temperatures (approximately 6000 K). Operating pressure is moderate (approximately 10 atm), with the result that the outlet hydrogen is virtually 100 percent dissociated to monatomic H. The molten fuel is contained in a solid container of its own material, which is rotated to stabilize the liquid layer by centripetal force. LARS reactor designs are described, together with neutronic and thermal-hydraulic analyses. Power levels are on the order of 200 megawatts. Typically, LARS designs use seven rotating fuel elements, are beryllium moderated, and have critical radii of approximately 100 cm (core L/D approximately equal to 1.5).

  12. A Research Agenda for the Common Core State Standards: What Information Do Policymakers Need?

    ERIC Educational Resources Information Center

    Rentner, Diane Stark; Ferguson, Maria

    2014-01-01

    This report looks specifically at the information and data needs of policymakers related to the Common Core State Standards (CCSS) and the types of research that could provide this information. The ideas in this report were informed by a series of meetings and discussions about a possible research agenda for the Common Core, sponsored by the…

  13. Energy Focusability of Annular Beams

    NASA Astrophysics Data System (ADS)

    Astadjov, Dimo N.

    2010-01-01

    A simulation of coherent annular flat two-level beams by two-dimensional Fast Fourier Transform is presented. After parameterization of the source beam (the `input') we examined the influence of its parameters on the shape and proportions of the output beam profile. The output pattern has a prominent central peak and faint rings concentrically surrounding it. The fraction of the central peak energy to the whole energy of beam, PF0 gives a notion of energy spread within the focal spot: PF0 is a function of beam annularity, k (i.e. `inside diameter/outside diameter' ratio) and the intensity dip, Idip of annulus central area (i.e. ring intensity minus central-bottom intensity, normalized). Up to k = 0.8 and Idip = 0.75, PF0 does not change too much—it is ⩾0.7 which is ⩾90% of PF0 maximum (0.778 at k = 0 and Idip = 0). Simulations revealed that even great changes in the shape of input beam annulus lead to small variations in the energy spread of output beam profile in the range of practical use of coherent annular beams.

  14. Core Journals of the Rapidly Changing Research Front of "Superconductivity."

    ERIC Educational Resources Information Center

    Brooks, Terrence A.

    1989-01-01

    Analyzes journals contributing to the literature on superconductivity from 1973 to 1987. Reveals that the literature has tripled in absolute size and has grown in intensity. Identifies core journals and reveals a communication pattern dominated by two journals, "Physical Review Letters" and "Physical Review B." Critiques problems of bibliometric…

  15. Infusing Qualitative Research Experiences into Core Counseling Curriculum Courses

    ERIC Educational Resources Information Center

    Letourneau, Jade L. H.

    2015-01-01

    Many calls to action for promoting research with counselors-in-training and producing research-practitioners have been published over the past few decades (Balkin 2013; Granello and Granello 1998; Heppner and Anderson 1985), yet the research-practice gap remains. This article explores how qualitative research may help bridge that gap and offers…

  16. Predicting multidimensional annular flows with a locally based two-fluid model

    SciTech Connect

    Antal, S.P. Edwards, D.P.; Strayer, T.D.

    1998-06-01

    Annular flows are a well utilized flow regime in many industrial applications, such as, heat exchangers, chemical reactors and industrial process equipment. These flows are characterized by a droplet laden vapor core with a thin, wavy liquid film wetting the walls. The prediction of annular flows has been largely confined to one-dimensional modeling which typically correlates the film thickness, droplet loading, and phase velocities by considering the average flow conditions and global mass and momentum balances to infer the flow topology. In this paper, a methodology to predict annular flows using a locally based two-fluid model of multiphase flow is presented. The purpose of this paper is to demonstrate a modeling approach for annular flows using a multifield, multidimensional two-fluid model and discuss the need for further work in this area.

  17. Annular Solar Eclipse of 10 May 1994

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, Jay

    1993-01-01

    An annular eclipse of the Sun will be widely visible from the Western Hemisphere on 10 May 1994. The path of the Moon's shadow passes through Mexico, the United States of America, maritime Canada, the North Atlantic, the Azores and Morocco. Detailed predictions for this event are presented and include tables of geographic coordinates of the annular path, local circumstances for hundreds of cities, maps of the path of annular and partial eclipse, weather prospects, and the lunar limb profile.

  18. Psoriatic Arthritis with Annular Pustular Psoriasis.

    PubMed

    Nagafuchi, Hiroko; Watanabe, Kyoko; Mikage, Hidenori; Ozaki, Shoichi

    2016-01-01

    We herein present the case of a 56-year-old woman who presented with symptoms of psoriatic arthritis (PsA) with erythema that progressed to annular pustular psoriasis. The patient had a 15-year history of polyarthritis. Annular pustular psoriasis is not typically observed in cases of arthritis. This is the first reported case of PsA with annular pustular psoriasis. PMID:26935375

  19. Entrainment measurements in annular flow

    SciTech Connect

    Assad, A.; Jan, C.; Bertodano, M. de; Beus, S.G.

    1997-07-01

    Air/water and vapor/freon were utilized to scale and simulate annular two-phase flow for high pressure steam/water conditions. A unique vapor/liquid Freon loop was built to obtain the high pressure data. The results were compared with two correlations available in the open literature. The Ishii and Mishima dimensionless group was able to scale the data remarkably well even for vapor/liquid Freon. However, the correlation needs to be adjusted for high Weber numbers of the gas phase.

  20. A Quantitative Assessment of the Research Chefs Association Core Competencies for the Practicing Culinologist

    ERIC Educational Resources Information Center

    Bissett, Rachel L.; Cheng, Michael S. H.; Brannan, Robert G.

    2010-01-01

    Professional organizations have linked core competency to professional success and competitive strategy. The Research Chefs Assn. (RCA) recently released 43 core competencies for practicing culinologists. Culinology[R] is a profession that links skills of culinary arts and food science and technology in the development of food products. An online…

  1. Simulation of cryogenic turbopump annular seals

    NASA Technical Reports Server (NTRS)

    Palazzolo, Alan B.

    1992-01-01

    The goal of the current work is to develop software that can accurately predict the dynamic coefficients, forces, leakage and horsepower loss for annular seals which have a potential for affecting the rotordynamic behavior of the pumps. The fruit of last year's research was the computer code SEALPAL which included capabilities for linear tapered geometry, Moody friction factor and inlet pre-swirl. This code produced results which in most cases compared very well with check cases presented in the literature. TAMUSEAL Icode, which was written to improve SEALPAL by correcting a bug and by adding more accurate integration algorithms and additional capabilities, was then used to predict dynamic coefficients and leakage for the NASA/Pratt and Whitney Alternate Turbopump Development (ATD) LOX Pump's seal.

  2. [Research on Assessment Methods of Spectrum Data Quality of Core Scan].

    PubMed

    Xiu, Lian-cun; Zheng, Zhi-zhong; Yin, Liang; Chen, Chun-xia; Yu, Zheng-kui; Huang, Bin; Zhang, Qiu-ning; Xiu, Xiao-xu; Gao, Yang

    2015-08-01

    Core scan is the instrument used for core spectrum and pictures detection that has been developed in recent years. Cores' data can be digitized with this equipment, then automatic core catalog can be achieved, which provides basis for geological research, mineral deposit study and peripheral deposit prospecting. Meanwhile, an online database of cores can be established by the means of core digitalization to solve the cost problem caused by core preservation and share resources. Quality of core data measurement directly affects the mineral identification, reliability of parameter inversion results. Therefore it's very important to quasi-manage the assessment of data quality with the instrument before cores' spectrum testing services. Combined with the independent R&D of CSD350A type core scan, and on the basis of spectroscopy basic theory, spectrum analysis methods, core spectrum analysis requirements, key issues such as data quality assessment methods, evaluation criteria and target parameters has been discussed in depth, and comprehensive assessment of independent R&D of core scan has been conducted, which indicates the reliability and validity of spectrum measurements of the instrument. Experimental tests show that the methods including test parameters and items can perfectly response the measurements of reflectance spectrum, wavelength accuracy, repeatability and signal to noise ratio with the instrument. Thus the quality of core scan data can be evaluated correctly, and the foundation of data quality for commercial services can be provided. In the case of the current lack of relevant assessment criteria, the method this study proposes for the assessment has great value in the work of core spectrum measurements.

  3. An experimental investigation of straight and curved annular wall jets

    NASA Technical Reports Server (NTRS)

    Rodman, L. C.; Wood, N. J.; Roberts, L.

    1987-01-01

    Accurate turbulence measurements taken in wall jet flows are difficult to obtain, due to high intensity turbulence and problems in achieving two-dimensionality. The problem is compounded when streamwise curvature of the flow is introduced, since the jet entrainment and turbulence levels are greatly increased over the equivalent planar values. In this experiment, two-dimensional straight and curved incompressible wall jet flows are simulated by having a jet blow axially over a cylinder. Hot wire measurements and some Laser Doppler Velocimetry measurements are presented for straight and curved wall jet flows. The results for the straight wall showed good agreement between the annular flow data and the rectangular data taken by previous researchers. For the jets with streamwise curvature, there was agreement between the annular and corresponding rectangular jets for the flow region closest to the slot exit. An integral analysis was used as a simple technique to interpret the experimental results. Integral momentum calculations were performed for both straight and curved annular and two dimensional wall jets. The results of the calculation were used to identify transverse curvature parameters and to predict the values of those parameters which would delineate the region where the annular flow can satisfactorily simulate two dimensional flow.

  4. Confocal Annular Josephson Tunnel Junctions

    NASA Astrophysics Data System (ADS)

    Monaco, Roberto

    2016-09-01

    The physics of Josephson tunnel junctions drastically depends on their geometrical configurations and here we show that also tiny geometrical details play a determinant role. More specifically, we develop the theory of short and long annular Josephson tunnel junctions delimited by two confocal ellipses. The behavior of a circular annular Josephson tunnel junction is then seen to be simply a special case of the above result. For junctions having a normalized perimeter less than one, the threshold curves in the presence of an in-plane magnetic field of arbitrary orientations are derived and computed even in the case with trapped Josephson vortices. For longer junctions, a numerical analysis is carried out after the derivation of the appropriate motion equation for the Josephson phase. We found that the system is modeled by a modified and perturbed sine-Gordon equation with a space-dependent effective Josephson penetration length inversely proportional to the local junction width. Both the fluxon statics and dynamics are deeply affected by the non-uniform annulus width. Static zero-field multiple-fluxon solutions exist even in the presence of a large bias current. The tangential velocity of a traveling fluxon is not determined by the balance between the driving and drag forces due to the dissipative losses. Furthermore, the fluxon motion is characterized by a strong radial inward acceleration which causes electromagnetic radiation concentrated at the ellipse equatorial points.

  5. Gas core nuclear thermal rocket engine research and development in the former USSR

    SciTech Connect

    Koehlinger, M.W.; Bennett, R.G.; Motloch, C.G.; Gurfink, M.M.

    1992-09-01

    Beginning in 1957 and continuing into the mid 1970s, the USSR conducted an extensive investigation into the use of both solid and gas core nuclear thermal rocket engines for space missions. During this time the scientific and engineering. problems associated with the development of a solid core engine were resolved. At the same time research was undertaken on a gas core engine, and some of the basic engineering problems associated with the concept were investigated. At the conclusion of the program, the basic principles of the solid core concept were established. However, a prototype solid core engine was not built because no established mission required such an engine. For the gas core concept, some of the basic physical processes involved were studied both theoretically and experimentally. However, no simple method of conducting proof-of-principle tests in a neutron flux was devised. This report focuses primarily on the development of the. gas core concept in the former USSR. A variety of gas core engine system parameters and designs are presented, along with a summary discussion of the basic physical principles and limitations involved in their design. The parallel development of the solid core concept is briefly described to provide an overall perspective of the magnitude of the nuclear thermal propulsion program and a technical comparison with the gas core concept.

  6. DEVELOPMENT OF A CORE COMBUSTION RESEARCH PROGRAM PLAN FOR EPA

    EPA Science Inventory

    The report described a plan, evolving from a review of the state- of-the-art in combustion research, for a long- term research program in combustion and thermal destruction. trawman plan was prepared and reviewed by a panel of representatives from industry, academia, and governme...

  7. Bistability and hysteresis of annular impinging jets

    NASA Astrophysics Data System (ADS)

    Tisovsky, Tomas

    2016-06-01

    In present study, the bistability and hysteresis of annular impinging jets is investigated. Annular impinging jets are simulated using open source CFD code - OpenFOAM. Both flow field patterns of interest are obtained and hysteresis is found by means of dynamic mesh simulation. Effect of nozzle exit velocity on resulting hysteresis loop is also illustrated.

  8. McCARD for Neutronics Design and Analysis of Research Reactor Cores

    NASA Astrophysics Data System (ADS)

    Shim, Hyung Jin; Park, Ho Jin; Kwon, Soonwoo; Seo, Geon Ho; Hyo Kim, Chang

    2014-06-01

    McCARD is a Monte Carlo (MC) neutron-photon transport simulation code developed exclusively for the neutronics design and analysis of nuclear reactor cores. McCARD is equipped with the hierarchical modeling and scripting functions, the CAD-based geometry processing module, the adjoint-weighted kinetics parameter and source multiplication factor estimation modules as well as the burnup analysis capability for the neutronics design and analysis of both research and power reactor cores. This paper highlights applicability of McCARD for the research reactor core neutronics analysis, as demonstrated for Kyoto University Critical Assembly, HANARO, and YALINA.

  9. [Generalized granuloma annulare or diffuse dermal histiocytosis?].

    PubMed

    Kretzschmar, L; Biel, K; Luger, T A; Goerdt, S

    1995-08-01

    Generalized granuloma annulare is a rare variant of granuloma annulare affecting the trunk and extremities with a multitude of lesions. In contrast to localized granuloma annulare, generalized granuloma annulare occurs in older patients, shows a stronger association with diabetes, and is characteristically chronic. Like our 55-year-old patient, most patients present with papules and annular plaques; less often, macular or non-annular lesions may be encountered. Histology often fails to show necrobiotic or necrotic connective tissue changes demarcated by a palisading granuloma. Instead, there are diffuse dermal, band-like or nodular aggregations of histiocytes intermingled with some multinucleated giant cells and a predominantly lymphocytic infiltrate in the periphery. Because of its special characteristics, it has been suggested that generalized granuloma annulare might constitute a separate disease entity and that it should be classed among the primary cutaneous histiocytoses as a diffuse dermal histiocytosis. Using immunohistochemistry to determine the macrophage phenotype of the lesional histiocytes, we have shown that generalized granuloma annulare is not a cutaneous histiocytosis. Neither MS-1 high-molecular-weight protein, a new specific marker for cutaneous non-Langerhans cell histiocytoses, nor CD1a, the well-known marker for Langerhans cells and Langerhans cell histiocytoses, is expressed by the lesional histiocytes of our patient. In contrast, the antigen expression pattern was diagnostic for non-infectious granulomas and was highly similar to that in localized granuloma annulare. In contrast to the successful treatment of localized granuloma annulare reported with intralesional interferon beta-1, systemic treatment with interferon alpha-2b (9 x 10(6) units three times a week) was ineffective.

  10. Psychotherapy training: Suggestions for core ingredients and future research.

    PubMed

    Boswell, James F; Castonguay, Louis G

    2007-12-01

    Despite our considerable depth and breadth of empirical knowledge on psychotherapy process and outcome, research on psychotherapy training is somewhat lacking. We would argue, however, that the scientist-practitioner model should not only guide practice, but also the way our field approaches training. In this paper we outline our perspective on the crucial elements of psychotherapy training based on available evidence, theory, and clinical experience, focusing specifically on the structure, key components, and important skills to be learned in a successful training program. In addition, we derive specific research directions based on the crucial elements of our proposed training perspective, and offer general considerations for research on training, including method and measurement issues. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  11. Core principles for involving people with dementia in research: innovative practice.

    PubMed

    2014-09-01

    The Scottish Dementia Working Group Research Sub-group is part of the Scottish Dementia Working Group, an internationally renowned campaigning group of people with dementia. We co-created our core principles for involving people with dementia in research between September and December 2013. The principles address six areas: (i) how people with dementia are valued and involved in research, (ii) lived experience as valid knowledge, (iii) physical and emotional safety, (iv) accessibility of all aspects of research, (v) training for researchers and (vi) the impact of our experiences of time on research processes. Through our core principles, we challenge researchers across all disciplines to re-consider how we and other people with dementia are involved in research as well as how knowledge in dementia research is created.

  12. IBEX - annular beam propagation experiment

    SciTech Connect

    Mazarakis, M G; Miller, R B; Shope, S L; Poukey, J W; Ramirez, J J; Ekdahl, C A; Adler, R J

    1983-01-01

    IBEX is a 4-MV, 100-kA, 20-ns cylindrical isolated Blumlein accelerator. In the experiments reported here, the accelerator is fitted with a specially designed foilless diode which is completely immersed in a uniform magnetic field. Several diode geometries have been studied as a function of magnetic field strength. The beam propagates a distance of 50 cm (approx. 10 cyclotron wavelengths) in vacuum before either striking a beam stop or being extracted through a thin foil. The extracted beam was successfully transported 60 cm downstream into a drift pipe filled either with 80 or 640 torr air. The main objectives of this experiment were to establish the proper parameters for the most quiescent 4 MV, 20 to 40 kA annular beam, and to compare the results with available theory and numerical code simulations.

  13. Means of manufacturing annular arrays

    DOEpatents

    Day, R.A.

    1985-10-10

    A method is described for manufacturing an annular acoustic transducer array from a plate of transducer material, which enables production of precision aligned arrays at low cost. The circular plate is sawed along at least two lines that are radial to the axis of the plate. At steps along each radial cut, the plate is rotated first in one direction and then in an opposite direction by a predetermined angle such as slightly less than 90/sup 0/. The cuts result in the forming of several largely ring-shaped lands, each largely ring-shaped land being joined to the other rings of different radii by thin portions of the plate, and each ring being cut into segments. The bridges that join different rings hold the transducer together until it can be mounted on a lens.

  14. Effective delayed neutron fraction and prompt neutron lifetime of Tehran research reactor mixed-core.

    PubMed

    Lashkari, A; Khalafi, H; Kazeminejad, H

    2013-05-01

    In this work, kinetic parameters of Tehran research reactor (TRR) mixed cores have been calculated. The mixed core configurations are made by replacement of the low enriched uranium control fuel elements with highly enriched uranium control fuel elements in the reference core. The MTR_PC package, a nuclear reactor analysis tool, is used to perform the analysis. Simulations were carried out to compute effective delayed neutron fraction and prompt neutron lifetime. Calculation of kinetic parameters is necessary for reactivity and power excursion transient analysis. The results of this research show that effective delayed neutron fraction decreases and prompt neutron lifetime increases with the fuels burn-up. Also, by increasing the number of highly enriched uranium control fuel elements in the reference core, the prompt neutron lifetime increases, but effective delayed neutron fraction does not show any considerable change. PMID:24976672

  15. Effective delayed neutron fraction and prompt neutron lifetime of Tehran research reactor mixed-core.

    PubMed

    Lashkari, A; Khalafi, H; Kazeminejad, H

    2013-05-01

    In this work, kinetic parameters of Tehran research reactor (TRR) mixed cores have been calculated. The mixed core configurations are made by replacement of the low enriched uranium control fuel elements with highly enriched uranium control fuel elements in the reference core. The MTR_PC package, a nuclear reactor analysis tool, is used to perform the analysis. Simulations were carried out to compute effective delayed neutron fraction and prompt neutron lifetime. Calculation of kinetic parameters is necessary for reactivity and power excursion transient analysis. The results of this research show that effective delayed neutron fraction decreases and prompt neutron lifetime increases with the fuels burn-up. Also, by increasing the number of highly enriched uranium control fuel elements in the reference core, the prompt neutron lifetime increases, but effective delayed neutron fraction does not show any considerable change.

  16. Effective delayed neutron fraction and prompt neutron lifetime of Tehran research reactor mixed-core

    PubMed Central

    Lashkari, A.; Khalafi, H.; Kazeminejad, H.

    2013-01-01

    In this work, kinetic parameters of Tehran research reactor (TRR) mixed cores have been calculated. The mixed core configurations are made by replacement of the low enriched uranium control fuel elements with highly enriched uranium control fuel elements in the reference core. The MTR_PC package, a nuclear reactor analysis tool, is used to perform the analysis. Simulations were carried out to compute effective delayed neutron fraction and prompt neutron lifetime. Calculation of kinetic parameters is necessary for reactivity and power excursion transient analysis. The results of this research show that effective delayed neutron fraction decreases and prompt neutron lifetime increases with the fuels burn-up. Also, by increasing the number of highly enriched uranium control fuel elements in the reference core, the prompt neutron lifetime increases, but effective delayed neutron fraction does not show any considerable change. PMID:24976672

  17. Design of radial phononic crystal using annular soft material with low-frequency resonant elastic structures

    NASA Astrophysics Data System (ADS)

    Gao, Nansha; Wu, Jiu Hui; Yu, Lie; Xin, Hang

    2016-10-01

    Using FEM, we theoretically study the vibration properties of radial phononic crystal (RPC) with annular soft material. The band structures, transmission spectra, and displacement fields of eigenmode are given to estimate the starting and cut-off frequency of band gaps. Numerical calculation results show that RPC with annular soft material can yield low-frequency band gaps below 350 Hz. Annular soft material decreases equivalent stiffness of the whole structure effectively, and makes corresponding band gaps move to the lower frequency range. Physical mechanism behind band gaps is the coupling effect between long or traveling wave in plate matrix and the vibrations of corrugations. By changing geometrical dimensions of plate thickness e, the length of silicone rubber h2, and the corrugation width b, we can control the location and width of the first band gap. These research conclusions of RPC structure with annular soft material can potentially be applied to optimize band gaps, generate filters, and design acoustic devices.

  18. High Thrust-to-Power Annular Engine Technology

    NASA Technical Reports Server (NTRS)

    Patterson, Michael; Thomas, Robert; Crofton, Mark; Young, Jason A.; Foster, John E.

    2015-01-01

    Gridded ion engines have the highest efficiency and total impulse of any mature electric propulsion technology, and have been successfully implemented for primary propulsion in both geocentric and heliocentric environments with excellent ground-in-space correlation of performance. However, they have not been optimized to maximize thrust-to-power, an important parameter for Earth orbit transfer applications. This publication discusses technology development work intended to maximize this parameter. These activities include investigating the capabilities of a non-conventional design approach, the annular engine, which has the potential of exceeding the thrust-to-power of other EP technologies. This publication discusses the status of this work, including the fabrication and initial tests of a large-area annular engine. This work is being conducted in collaboration among NASA Glenn Research Center, The Aerospace Corporation, and the University of Michigan.

  19. High Thrust-to-Power Annular Engine Technology

    NASA Technical Reports Server (NTRS)

    Patterson, Michael J.; Thomas, Robert E.; Crofton, Mark W.; Young, Jason A.; Foster, John E.

    2015-01-01

    Gridded ion engines have the highest efficiency and total impulse of any mature electric propulsion technology, and have been successfully implemented for primary propulsion in both geocentric and heliocentric environments with excellent ground/in-space correlation of performance. However, they have not been optimized to maximize thrust-to-power, an important parameter for Earth orbit transfer applications. This publication discusses technology development work intended to maximize this parameter. These activities include investigating the capabilities of a non-conventional design approach, the annular engine, which has the potential of exceeding the thrust-to-power of other EP technologies. This publication discusses the status of this work, including the fabrication and initial tests of a large-area annular engine. This work is being conducted in collaboration among NASA Glenn Research Center, The Aerospace Corporation, and the University of Michigan.

  20. ACT-CCREC Core Research Program: Study Questions and Design. ACT Working Paper Series. WP-2015-01

    ERIC Educational Resources Information Center

    Cruce, Ty M.

    2015-01-01

    This report provides a non-technical overview of the guiding research questions and research design for the ACT-led core research program conducted on behalf of the GEAR UP College and Career Readiness Evaluation Consortium (CCREC). The core research program is a longitudinal study of the effectiveness of 14 GEAR UP state grants on the academic…

  1. Adaptive optics scanning ophthalmoscopy with annular pupils.

    PubMed

    Sulai, Yusufu N; Dubra, Alfredo

    2012-07-01

    Annular apodization of the illumination and/or imaging pupils of an adaptive optics scanning light ophthalmoscope (AOSLO) for improving transverse resolution was evaluated using three different normalized inner radii (0.26, 0.39 and 0.52). In vivo imaging of the human photoreceptor mosaic at 0.5 and 10° from fixation indicates that the use of an annular illumination pupil and a circular imaging pupil provides the most benefit of all configurations when using a one Airy disk diameter pinhole, in agreement with the paraxial confocal microscopy theory. Annular illumination pupils with 0.26 and 0.39 normalized inner radii performed best in terms of the narrowing of the autocorrelation central lobe (between 7 and 12%), and the increase in manual and automated photoreceptor counts (8 to 20% more cones and 11 to 29% more rods). It was observed that the use of annular pupils with large inner radii can result in multi-modal cone photoreceptor intensity profiles. The effect of the annular masks on the average photoreceptor intensity is consistent with the Stiles-Crawford effect (SCE). This indicates that combinations of images of the same photoreceptors with different apodization configurations and/or annular masks can be used to distinguish cones from rods, even when the former have complex multi-modal intensity profiles. In addition to narrowing the point spread function transversally, the use of annular apodizing masks also elongates it axially, a fact that can be used for extending the depth of focus of techniques such as adaptive optics optical coherence tomography (AOOCT). Finally, the positive results from this work suggest that annular pupil apodization could be used in refractive or catadioptric adaptive optics ophthalmoscopes to mitigate undesired back-reflections.

  2. Annular-Cross-Section CFE Chamber

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

  3. Annular gel reactor for chemical pattern formation

    DOEpatents

    Nosticzius, Zoltan; Horsthemke, Werner; McCormick, William D.; Swinney, Harry L.; Tam, Wing Y.

    1990-01-01

    The present invention is directed to an annular gel reactor suitable for the production and observation of spatiotemporal patterns created during a chemical reaction. The apparatus comprises a vessel having at least a first and second chamber separated one from the other by an annular polymer gel layer (or other fine porous medium) which is inert to the materials to be reacted but capable of allowing diffusion of the chemicals into it.

  4. Annular flow optimization: A new integrated approach

    SciTech Connect

    Maglione, R.; Robotti, G.; Romagnoli, R.

    1997-07-01

    During the drilling stage of an oil and gas well the hydraulic circuit of the mud assumes great importance with respect to most of the numerous and various constituting parts (mostly in the annular sections). Each of them has some points to be satisfied in order to guarantee both the safety of the operations and the performance optimization of each of the single elements of the circuit. The most important tasks for the annular part of the drilling hydraulic circuit are the following: (1) Maximum available pressure to the last casing shoe; (2) avoid borehole wall erosions; and (3) guarantee the hole cleaning. A new integrated system considering all the elements of the annular part of the drilling hydraulic circuit and the constraints imposed from each of them has been realized. In this way the family of the flow parameters (mud rheology and pump rate) satisfying simultaneously all the variables of the annular section has been found. Finally two examples regarding a standard and narrow annular section (slim hole) will be reported, showing briefly all the steps of the calculations until reaching the optimum flow parameters family (for that operational condition of drilling) that satisfies simultaneous all the flow parameters limitations imposed by the elements of the annular section circuit.

  5. Stress localisation in annular sheets

    NASA Astrophysics Data System (ADS)

    van der Heijden, Gert; Starostin, Eugene

    2015-03-01

    For very thin sheets stretching is much more costly in terms of energy than bending. The limiting behaviour of thin sheets is therefore governed by geometry only and thus applies to a wide range of materials at vastly different scales: it is equally valid for a microscopic graphene sheet and a macroscopic solar sail. We derive new geometrically-exact equations for the deformation of annular strips. We use a formulation in which the inextensibility constraint is used to reduce the problem to a suitably-chosen reference curve (here the circular centreline). The equations are therefore ODEs, which allow for a detailed bifurcation analysis. Closed conical solutions are found for centreline lengths L less than Lc = 2 πκg , where κg is the geodesic curvature of the strip. For such `short' strips we find in addition a second branch of stable solutions easily reproduced in a paper strip. For `long' strips (L >Lc) we find modes of undulating solutions. All non-conical solutions turn out to feature points of stress localisation on the edge of the annulus, the outer edge for short solutions and the inner edge of long solutions. Our theory may be used to investigate singularities of constrained or loaded sheets more general than conical ones.

  6. COVERING A CORE BY EXTRUSION

    DOEpatents

    Karnie, A.J.

    1963-07-16

    A method of covering a cylindrical fuel core with a cladding metal ms described. The metal is forced between dies around the core from both ends in two opposing skirts, and as these meet the ends turn outward into an annular recess in the dics. By cutting off the raised portion formed by the recess, oxide impurities are eliminated. (AEC)

  7. Research and Policy: Informational Texts and the Common Core Standards: What Are We Talking about, Anyway?

    ERIC Educational Resources Information Center

    Maloch, Beth; Bomer, Randy

    2013-01-01

    This column responds to a recent push in education policy toward a curriculum that requires students to read and write more informational texts. Most evident in the now well-known Common Core State Standards, these policy moves echo, in some ways, a call by researchers for more informational texts, particularly in primary classrooms. In this…

  8. Characterization of the fast neutron irradiation facility of the Portuguese Research Reactor after core conversion.

    PubMed

    Marques, J G; Sousa, M; Santos, J P; Fernandes, A C

    2011-08-01

    The fast neutron irradiation facility of the Portuguese Research Reactor was characterized after the reduction in uranium enrichment and rearrangement of the core configuration. In this work we report on the determination of the hardness parameter and the 1MeV equivalent neutron flux along the facility, in the new irradiation conditions, following ASTM E722 standard.

  9. The Reporting of Core Program Components: An Overlooked Barrier for Moving Research into Practice

    ERIC Educational Resources Information Center

    Maggin, Daniel M.; Johnson, Austin H.

    2015-01-01

    The successful implementation of school-based behavioral interventions requires school personnel to be competent with program content and procedures. An unfortunate trend within school-based behavioral intervention research is that the core intervention components and implementation features are often not fully described. Without clear…

  10. Research-Based Writing Practices and the Common Core: Meta-Analysis and Meta-Synthesis

    ERIC Educational Resources Information Center

    Graham, Steve; Harris, Karen R.; Santangelo, Tanya

    2015-01-01

    In order to meet writing objectives specified in the Common Core State Standards (CCSS), many teachers need to make significant changes in how writing is taught. While CCSS identified what students need to master, it did not provide guidance on how teachers are to meet these writing benchmarks. The current article presents research-supported…

  11. Ten Core Principles for Designing Effective Learning Environments: Insights from Brain Research and Pedagogical Theory

    ERIC Educational Resources Information Center

    Boettcher, Judith V.

    2007-01-01

    In this article, Judith V. Boettcher provides ten core learning principles that can guide technology-enhanced teaching as well as more traditional forms of instruction. Drawn from both traditional pedagogical theory as well as current research about how people learn, the ten principles integrate these findings in a helpful set of guidelines that…

  12. Transition phase of the whole-core demonstration at the Oak Ridge Research Reactor

    SciTech Connect

    Hobbs, R.W.; Bretscher, M.M.; Cornella, R.J.; Snelgrove, J.L.

    1986-01-01

    The transition from operation of the Oak Ridge Research Reactor with high-enrichment uranium (HEU) fuel to operation with low-enrichment uranium (LEU) fuel is nearing completion. The systematics of the replacement of the HEU fuel with the LEU fuel are discussed. The results of the core physics measurements that have been conducted during the transition phase are described.

  13. Challenging the Research Base of the Common Core State Standards: A Historical Reanalysis of Text Complexity

    ERIC Educational Resources Information Center

    Gamson, David A.; Lu, Xiaofei; Eckert, Sarah Anne

    2013-01-01

    The widely adopted Common Core State Standards (CCSS) call for raising the level of text complexity in textbooks and reading materials used by students across all grade levels in the United States; the authors of the English Language Arts component of the CCSS build their case for higher complexity in part upon a research base they say shows a…

  14. New Funding Opportunity: Biospecimen Core Resource - Office of Cancer Clinical Proteomics Research

    Cancer.gov

    The purpose of this notice is to notify the community that the National Cancer Institute's (NCI’s) Office of Cancer Clinical Proteomics Research (OCCPR) is seeking sources to establish a Biospecimen Core Resource (BCR), capable of receiving, qualifying, processing, and distributing annotated biospecimens.

  15. Dual annular rotating [open quotes]windowed[close quotes] nuclear reflector reactor control system

    DOEpatents

    Jacox, M.G.; Drexler, R.L.; Hunt, R.N.M.; Lake, J.A.

    1994-03-29

    A nuclear reactor control system is provided in a nuclear reactor having a core operating in the fast neutron energy spectrum where criticality control is achieved by neutron leakage. The control system includes dual annular, rotatable reflector rings. There are two reflector rings: an inner reflector ring and an outer reflector ring. The reflectors are concentrically assembled, surround the reactor core, and each reflector ring includes a plurality of openings. The openings in each ring are capable of being aligned or non-aligned with each other. Independent driving means for each of the annular reflector rings is provided so that reactor criticality can be initiated and controlled by rotation of either reflector ring such that the extent of alignment of the openings in each ring controls the reflection of neutrons from the core. 4 figures.

  16. Global ice-core research: Understanding and applying environmental records of the past

    USGS Publications Warehouse

    Cecil, L. DeWayne; Green, Jaromy R.; Naftz, David L.

    2000-01-01

    Environmental changes are of major concern at low- or mid-latitude regions of our Earth simply because this is where 80 to 90 percent of the world’s human population live. Ice cores collected from isolated polar regions are, at best, proxy indicators of low- and mid-latitude environmental changes. Because polar icecore research is limiting in this sense, ice cores from low- and mid-latitude glaciers are being used to study past environmental changes in order to better understand and predict future environmental changes that may affect the populated regions of the world.

  17. The limit of the film extraction technique for annular two-phase flow in a small tube

    SciTech Connect

    Helm, D.E.; Lopez de Bertodano, M.; Beus, S.G.

    1999-07-01

    The limit of the liquid film extraction technique was identified in air-water and Freon-113 annular two-phase flow loops. The purpose of this research is to find the limit of the entrainment rate correlation obtained by Lopez de Bertodano et al. (1998). The film extraction technique involves the suction of the liquid film through a porous tube and has been widely used to obtain annular flow entrainment and entrainment rate data. In the experiments there are two extraction probes. After the first extraction the entrained droplets in the gas core deposit on the tube wall. A new liquid film develops entirely from liquid deposition and a second liquid film extraction is performed. While it is assumed that the entire liquid film is removed after the first extraction unit, this is not true for high liquid flow. At high liquid film flows the interfacial structure of the film becomes frothy. Then the entire liquid film cannot be removed at the first extraction unit, but continues on and is extracted at the second extraction unit. A simple model to characterize the limit of the extraction technique was obtained based on the hypothesis that the transition occurs due to a change in the wave structure. The resulting dimensionless correlation agrees with the data.

  18. The limit of the film extraction technique for annular two-phase flow in a small tube

    SciTech Connect

    Helm, D.E.; Lopez de Bertodano, M.; Beus, S.G.

    1999-07-01

    The limit of the liquid film extraction technique was identified in air-water and Freon-113 annular two-phase flow loops. The purpose of this research is to find the limit of the entrainment rate correlation obtained by Lopez de Bertodano et. al. (1998). The film extraction technique involves the suction of the liquid film through a porous tube and has been widely used to obtain annular flow entrainment and entrainment rate data. In these experiments there are two extraction probes. After the first extraction the entrained droplets in the gas core deposit on the tube wall. A new liquid film develops entirely from liquid deposition and a second liquid film extraction is performed. While it is assumed that the entire liquid film is removed after the first extraction unit, this is not true for high liquid flow. At high liquid film flows the interfacial structure of the film becomes frothy. Then the entire liquid film cannot be removed at the first extraction unit, but continues on and is extracted at the second extraction unit. A simple model to characterize the limit of the extraction technique was obtained based on the hypothesis that the transition occurs due to a change in the wave structure. The resulting dimensionless correlation agrees with the data.

  19. Cold neutron tomography of annular coolant flow in a double subchannel model of a boiling water reactor

    NASA Astrophysics Data System (ADS)

    Kickhofel, J. L.; Zboray, R.; Damsohn, M.; Kaestner, A.; Lehmann, E. H.; Prasser, H.-M.

    2011-09-01

    Dryout of the liquid coolant film on fuel pins at the top of boiling water reactor (BWR) cores constitutes the type of heat transfer crisis relevant for the conditions of high void fractions. It is a limiting factor in the thermal power, and therefore the economy, of BWRs. Ongoing research on multiphase annular flow, specifically the liquid film thickness, is fundamental not only to nuclear reactor safety and operation but also to that of evaporators, condensers, and pipelines in a general industrial context. We have performed cold neutron tomography of adiabatic air water annular flow in a scaled up model of the subchannel geometry found in BWR fuel assemblies today. All imaging has been performed at the ICON beamline at the neutron spallation source SINQ at the Paul Scherrer Institut in Switzerland. Neutron tomography is shown to excel in investigating the interactions of air water two phase flows with spacer vanes of different geometry. The high resolution, high contrast measurements provide spatial distributions of the coolant on top of the surfaces of the spacer, including the vanes, and in the subchannel downstream of the spacers.

  20. The Translational Genomics Core at Partners Personalized Medicine: Facilitating the Transition of Research towards Personalized Medicine.

    PubMed

    Blau, Ashley; Brown, Alison; Mahanta, Lisa; Amr, Sami S

    2016-01-01

    The Translational Genomics Core (TGC) at Partners Personalized Medicine (PPM) serves as a fee-for-service core laboratory for Partners Healthcare researchers, providing access to technology platforms and analysis pipelines for genomic, transcriptomic, and epigenomic research projects. The interaction of the TGC with various components of PPM provides it with a unique infrastructure that allows for greater IT and bioinformatics opportunities, such as sample tracking and data analysis. The following article describes some of the unique opportunities available to an academic research core operating within PPM, such the ability to develop analysis pipelines with a dedicated bioinformatics team and maintain a flexible Laboratory Information Management System (LIMS) with the support of an internal IT team, as well as the operational challenges encountered to respond to emerging technologies, diverse investigator needs, and high staff turnover. In addition, the implementation and operational role of the TGC in the Partners Biobank genotyping project of over 25,000 samples is presented as an example of core activities working with other components of PPM. PMID:26927185

  1. The Translational Genomics Core at Partners Personalized Medicine: Facilitating the Transition of Research towards Personalized Medicine

    PubMed Central

    Blau, Ashley; Brown, Alison; Mahanta, Lisa; Amr, Sami S.

    2016-01-01

    The Translational Genomics Core (TGC) at Partners Personalized Medicine (PPM) serves as a fee-for-service core laboratory for Partners Healthcare researchers, providing access to technology platforms and analysis pipelines for genomic, transcriptomic, and epigenomic research projects. The interaction of the TGC with various components of PPM provides it with a unique infrastructure that allows for greater IT and bioinformatics opportunities, such as sample tracking and data analysis. The following article describes some of the unique opportunities available to an academic research core operating within PPM, such the ability to develop analysis pipelines with a dedicated bioinformatics team and maintain a flexible Laboratory Information Management System (LIMS) with the support of an internal IT team, as well as the operational challenges encountered to respond to emerging technologies, diverse investigator needs, and high staff turnover. In addition, the implementation and operational role of the TGC in the Partners Biobank genotyping project of over 25,000 samples is presented as an example of core activities working with other components of PPM. PMID:26927185

  2. Quantifying the uncertainty of the annular mode time scale and the role of the stratosphere

    NASA Astrophysics Data System (ADS)

    Kim, Junsu; Reichler, Thomas

    2016-07-01

    The proper simulation of the annular mode time scale may be regarded as an important benchmark for climate models. Previous research demonstrated that this time scale is systematically overestimated by climate models. As suggested by the fluctuation-dissipation theorem, this may imply that climate models are overly sensitive to external forcings. Previous research also made it clear that calculating the AM time scale is a slowly converging process, necessitating relatively long time series and casting doubts on the usefulness of the historical reanalysis record to constrain climate models in terms of the annular mode time scale. Here, we use long control simulations with the coupled and uncoupled version of the GFDL climate model, CM2.1 and AM2.1, respectively, to study the effects of internal atmospheric variability and forcing from the lower boundary on the stability of the annular mode time scale. In particular, we ask whether a model's annular mode time scale and dynamical sensitivity can be constrained from the 50-year-long reanalysis record. We find that internal variability attaches large uncertainty to the annular mode time scale when diagnosed from decadal records. Even under the fixed forcing conditions of our long control run at least 100 years of data are required in order to keep the uncertainty in the annular mode time scale of the Northern Hemisphere to 10 %; over the Southern Hemisphere, the required length increases to 200 years. If nature's annular mode time scale over the Northern Hemisphere is similarly variable, there is no guarantee that the historical reanalysis record is a fully representative target for model evaluation. Over the Southern Hemisphere, however, the discrepancies between model and reanalysis are sufficiently large to conclude that the model is unable to reproduce the observed time scale structure correctly. The effects of ocean coupling lead to a considerable increase in time scale and uncertainty in time scale, effects which

  3. The microstructure of polar ice. Part I: Highlights from ice core research

    NASA Astrophysics Data System (ADS)

    Faria, Sérgio H.; Weikusat, Ilka; Azuma, Nobuhiko

    2014-04-01

    Polar ice sheets play a fundamental role in Earth's climate system, by interacting actively and passively with the environment. Active interactions include the creeping flow of ice and its effects on polar geomorphology, global sea level, ocean and atmospheric circulation, and so on. Passive interactions are mainly established by the formation of climate records within the ice, in form of air bubbles, dust particles, salt microinclusions and other derivatives of airborne impurities buried by recurrent snowfalls. For a half-century scientists have been drilling deep ice cores in Antarctica and Greenland for studying such records, which can go back to around a million years. Experience shows, however, that the ice-sheet flow generally disrupts the stratigraphy of the bottom part of deep ice cores, destroying the integrity of the oldest records. For all these reasons glaciologists have been studying the microstructure of polar ice cores for decades, in order to understand the genesis and fate of ice-core climate records, as well as to learn more about the physical properties of polar ice, aiming at better climate-record interpretations and ever more precise models of ice-sheet dynamics. In this Part I we review the main difficulties and advances in deep ice core drilling in Antarctica and Greenland, together with the major contributions of deep ice coring to the research on natural ice microstructures. In particular, we discuss in detail the microstructural findings from Camp Century, Byrd, Dye 3, GRIP, GISP2, NorthGRIP, Vostok, Dome C, EDML, and Dome Fuji, besides commenting also on the earlier results of some pioneering ventures, like the Jungfraujoch Expedition and the Norwegian-British-Swedish Antarctic Expedition, among others. In the companion Part II of this work (Faria et al., 2014), the review proceeds with a survey of the state-of-the-art understanding of natural ice microstructures and some exciting prospects in this field of research.

  4. Annular feed air breathing fuel cell stack

    DOEpatents

    Wilson, Mahlon S.

    1996-01-01

    A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

  5. Active annular-beam laser autocollimator system.

    PubMed

    Yoder, P R; Schlesinger, E R; Chickvary, J L

    1975-08-01

    An autocollimator using an axicon and a beam expander telescope to generate a 12.5-cm. o.d. annular beam of helium-neon laser light with high (25:1) diameter-to-width ratio has been developed. It is used with a two-axis, electromagnetically actuated mirror assembly to acquire automatically and maintain dynamically autocollimation from a nearby but separately mounted annular mirror. The servo system controls beam alignment even though angular vibratory motions of the annular mirror make it appear to tilt relative to the autocollimator as much as 7 mrad at frequencies below 300 Hz. This paper describes the optical system and the alignment sensing and control system.

  6. Annular bilayer magnetoelectric composites: theoretical analysis.

    PubMed

    Guo, Mingsen; Dong, Shuxiang

    2010-01-01

    The laminated bilayer magnetoelectric (ME) composites consist of magnetostrictive and piezoelectric layers are known to have giant ME coefficient due to the high coupling efficiency in bending mode. In our previous report, the bar-shaped bilayer composite has been investigated by using a magnetoelectric-coupling equivalent circuit. Here, we propose an annular bilayer ME composite, which consists of magnetostrictive and piezoelectric rings. This composite has a much lower resonance frequency of bending mode compared with its radial mode. In addition, the annular bilayer ME composite is expected to respond to vortex magnetic field as well as unidirectional magnetic field. In this paper, we investigate the annular bilayer ME composite by using impedance-matrix method and predict the ME coefficients as a function of geometric parameters of the composites. PMID:20178914

  7. Annular subaperture stitching method based on autocollimation

    NASA Astrophysics Data System (ADS)

    Yiwei, Chen; Erlong, Miao; Yongxin, Sui; Huaijiang, Yang

    2014-11-01

    In this paper, we propose an annular subaperture stitching method based on an autocollimation method to relax the requirements on mechanical location accuracy. In this approach, we move a ball instead of the interferometer and the aspheric surface so that testing results for adjacent annular subapertures are registered. Thus, the stitching algorithm can easily stitch the subaperture testing results together when large mechanical location errors exist. To verify this new method, we perform a simulation experiment. The simulation results demonstrate that this method can stitch together the subaperture testing results under large mechanical location errors.

  8. Annular-gap washer including electrode means

    SciTech Connect

    Hegemann, K.; Kautz, J.W.; Weissert, H.

    1982-02-23

    An annular-gap washer especially for scrubbing of industrial gases, comprises a central body which is axially shiftable in a housing defining an all-around clearance with the body. The clearance forms an annular gap through which the gas stream and water droplets from a spray nozzle axially spaced from the gap, are accelerated and brought into intimate contact. According to the invention at least over part of the gap, the mixture is subjected to an electrostatic field having generally radial field lines.

  9. Cancer Core Europe: a consortium to address the cancer care-cancer research continuum challenge.

    PubMed

    Eggermont, Alexander M M; Caldas, Carlos; Ringborg, Ulrik; Medema, René; Tabernero, Josep; Wiestler, Otmar

    2014-11-01

    European cancer research for a transformative initiative by creating a consortium of six leading excellent comprehensive cancer centres that will work together to address the cancer care-cancer research continuum. Prerequisites for joint translational and clinical research programs are very demanding. These require the creation of a virtual single 'e-hospital' and a powerful translational platform, inter-compatible clinical molecular profiling laboratories with a robust underlying computational biology pipeline, standardised functional and molecular imaging, commonly agreed Standard Operating Procedures (SOPs) for liquid and tissue biopsy procurement, storage and processing, for molecular diagnostics, 'omics', functional genetics, immune-monitoring and other assessments. Importantly also it requires a culture of data collection and data storage that provides complete longitudinal data sets to allow for: effective data sharing and common database building, and to achieve a level of completeness of data that is required for conducting outcome research, taking into account our current understanding of cancers as communities of evolving clones. Cutting edge basic research and technology development serve as an important driving force for innovative translational and clinical studies. Given the excellent track records of the six participants in these areas, Cancer Core Europe will be able to support the full spectrum of research required to address the cancer research- cancer care continuum. Cancer Core Europe also constitutes a unique environment to train the next generation of talents in innovative translational and clinical oncology. PMID:25263570

  10. Radiation Characterization Summary: ACRR Central Cavity Free-Field Environment with the 32-Inch Pedestal at the Core Centerline (ACRR-FF-CC-32-cl).

    SciTech Connect

    Vega, Richard Manuel; Parma, Edward J.; Naranjo, Gerald E.; Lippert, Lance L.; Vehar, David W.; Griffin, Patrick J.

    2015-08-01

    This document presents the facilit y - recommended characteri zation o f the neutron, prompt gamma - ray, and delayed gamma - ray radiation fields in the Annular Core Research Reactor ( ACRR ) for the cen tral cavity free - field environment with the 32 - inch pedestal at the core centerline. The designation for this environmen t is ACRR - FF - CC - 32 - cl. The neutron, prompt gamma - ray , and delayed gamma - ray energy spectra , uncertainties, and covariance matrices are presented as well as radial and axial neutron and gamma - ray fluence profiles within the experiment area of the cavity . Recommended constants are given to facilitate the conversion of various dosimetry readings into radiation metrics desired by experimenters. Representative pulse operations are presented with conversion examples . Acknowledgements The authors wish to th ank the Annular Core Research Reactor staff and the Radiation Metrology Laboratory staff for their support of this work . Also thanks to David Ames for his assistance in running MCNP on the Sandia parallel machines.

  11. Code System to Calculate Mixed Cores in TRIGA Mark II Research Reactor.

    2001-08-29

    Version 00 TRIGLAV is a computer program for reactor calculations of mixed cores in a TRIGA Mark II research reactor. It can be applied for fuel element burn-up calculations, for power and flux distributions calculations and for reactivity predictions. The TRIGLAV program requires the WIMS-D4 program with the original WIMS cross-section library extended for TRIGA reactor specific nuclides. This package includes the code TRIGAC, which is a new version of TRIGAP.

  12. Clinical Research of Traditional Chinese Medicine Needs to Develop Its Own System of Core Outcome Sets

    PubMed Central

    Zhang, Li; Zhang, Junhua; Chen, Jing; Xing, Dongmei; Wang, Jiaying

    2013-01-01

    Currently, quality issues concerning clinical research of traditional Chinese medicine (TCM) have come into the spotlight. It has been recognized that poorly-devised research methodology largely restricted the development of clinical research in TCM. The choice of appropriate outcome measurements is key to the success of clinical research; however, the current procedure for outcomes selection in clinical research of TCM is problematic due to the underdevelopment of clinical methodology. Under this circumstance, we propose the introduction to the concept of Core Outcome Set (COS) and discuss the feasibility of developing a COS system that caters for clinical studies in TCM, in the hope that the outcome evaluation system could be up to international standards. PMID:24312133

  13. Two-phase flow characteristic of inverted bubbly, slug and annular flow in post-critical heat flux region

    SciTech Connect

    Ishii, M.; Denten, J.P.

    1988-01-01

    Inverted annular flow can be visualized as a liquid jet-like core surrounded by a vapor annulus. While many analytical and experimental studies of heat transfer in this regime have been performed, there is very little understanding of the basic hydrodynamics of the post-CHF flow field. However, a recent experimental study was done that was able to successfully investigate the effects of various steady-state inlet flow parameters on the post-CHF hydrodynamics of the film boiling of a single phase liquid jet. This study was carried out by means of a visual photographic analysis of an idealized single phase core inverted annular flow initial geometry (single phase liquid jet core surrounded by a coaxial annulus of gas). In order to extend this study, a subsequent flow visualization of an idealized two-phase core inverted annular flow geometry (two-phase central jet core, surrounded by a coaxial annulus of gas) was carried out. The objective of this second experimental study was to investigate the effect of steady-state inlet, pre-CHF two-phase jet core parameters on the hydrodynamics of the post-CHF flow field. In actual film boiling situations, two-phase flows with net positive qualities at the CHF point are encountered. Thus, the focus of the present experimental study was on the inverted bubbly, slug, and annular flow fields in the post dryout film boiling region. Observed post dryout hydrodynamic behavior is reported. A correlation for the axial extent of the transition flow pattern between inverted annular and dispersed droplet flow (the agitated regime) is developed. It is shown to depend strongly on inlet jet core parameters and jet void fraction at the dryout point. 45 refs., 9 figs., 4 tabs.

  14. 75 FR 23582 - Annular Casing Pressure Management for Offshore Wells

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ... published the proposed rule Annular Casing Pressure Management for Offshore Wells (74 FR 38147). The comment... the published proposed rule 1010-AD47 Annular Casing Pressure Management for Offshore Wells (74 FR... Minerals Management Service 30 CFR Part 250 RIN 1010-AD47 Annular Casing Pressure Management for...

  15. Annular beam with segmented phase gradients

    NASA Astrophysics Data System (ADS)

    Cheng, Shubo; Wu, Liang; Tao, Shaohua

    2016-08-01

    An annular beam with a single uniform-intensity ring and multiple segments of phase gradients is proposed in this paper. Different from the conventional superposed vortices, such as the modulated optical vortices and the collinear superposition of multiple orbital angular momentum modes, the designed annular beam has a doughnut intensity distribution whose radius is independent of the phase distribution of the beam in the imaging plane. The phase distribution along the circumference of the doughnut beam can be segmented with different phase gradients. Similar to a vortex beam, the annular beam can also exert torques and rotate a trapped particle owing to the orbital angular momentum of the beam. As the beam possesses different phase gradients, the rotation velocity of the trapped particle can be varied along the circumference. The simulation and experimental results show that an annular beam with three segments of different phase gradients can rotate particles with controlled velocities. The beam has potential applications in optical trapping and optical information processing.

  16. Interfacial transfer in annular dispersed flow. [PWR; BWR

    SciTech Connect

    Ishii, M.; Kataoka, I.

    1982-01-01

    The interfacial drag, droplet entrainment, droplet deposition and droplet-size distributions are important for detailed mechanistic modeling of annular dispersed two-phase flow. In view of this, recently developed correlations for these parameters are presented and discussed in this paper. The onset of droplet entrainment significantly alters the mechanisms of mass, momentum, and energy transfer between the film and gas core flow as well as the transfer between the two-phase mixture and the wall. By assuming the roll wave entrainment mechanism, the correlations for the amount of entrained droplet as well as for the droplet-size distribution have been obtained from a simple model in collaboration with a large number of data. Then the rate equations for entrainment and deposition have been developed. The drag correlations relevant to the droplet transfer is also presented. The comparison of the correlations to various data show satisfactory agreement.

  17. Hydrodynamics of annular-dispersed flow. [PWR; BWR

    SciTech Connect

    Ishii, M.; Kataoka, I.

    1982-01-01

    The interfacial drag, droplet entrainment, and droplet size distributions are important for detailed mechanistic modeling of annular dispersed two-phase flow. In view of this, recently developed correlations for these parameters are presented and discussed in this paper. The drag correlations for multiple fluid particle systems have been developed from a similarity hypothesis based on the mixture viscosity model. The results show that the drag coefficient depends on the particle Reynolds number and droplet concentration. The onset on droplet entrainment significantly alters the mechanisms of mass, momentum, and energy transfer between the film and gas core flow as well as the transfer between the two-phase mixture and the wall. By assuming the roll wave entrainment mechanism, the correlations for the amount of entrained droplet as well as for the droplet size distribution have been obtained from a simple model in collaboration with a large number of data.

  18. Drug-resistant tuberculosis clinical trials: proposed core research definitions in adults.

    PubMed

    Furin, J; Alirol, E; Allen, E; Fielding, K; Merle, C; Abubakar, I; Andersen, J; Davies, G; Dheda, K; Diacon, A; Dooley, K E; Dravnice, G; Eisenach, K; Everitt, D; Ferstenberg, D; Goolam-Mahomed, A; Grobusch, M P; Gupta, R; Harausz, E; Harrington, M; Horsburgh, C R; Lienhardt, C; McNeeley, D; Mitnick, C D; Nachman, S; Nahid, P; Nunn, A J; Phillips, P; Rodriguez, C; Shah, S; Wells, C; Thomas-Nyang'wa, B; du Cros, P

    2016-03-01

    Drug-resistant tuberculosis (DR-TB) is a growing public health problem, and for the first time in decades, new drugs for the treatment of this disease have been developed. These new drugs have prompted strengthened efforts in DR-TB clinical trials research, and there are now multiple ongoing and planned DR-TB clinical trials. To facilitate comparability and maximise policy impact, a common set of core research definitions is needed, and this paper presents a core set of efficacy and safety definitions as well as other important considerations in DR-TB clinical trials work. To elaborate these definitions, a search of clinical trials registries, published manuscripts and conference proceedings was undertaken to identify groups conducting trials of new regimens for the treatment of DR-TB. Individuals from these groups developed the core set of definitions presented here. Further work is needed to validate and assess the utility of these definitions but they represent an important first step to ensure there is comparability in clinical trials on multidrug-resistant TB.

  19. Evidence of meniscus interface transport in dip-pen nanolithography: An annular diffusion model

    NASA Astrophysics Data System (ADS)

    Nafday, Omkar A.; Vaughn, Mark W.; Weeks, Brandon L.

    2006-10-01

    Ring shaped dots were patterned with mercaptohexadecanoic acid ink by dip-pen nanolithography. These dots have an ink-free inner core surrounded by an inked annular region, making them different from the filled dots usually obtained. This suggests a different transport mechanism than the current hypothesis of bulk water meniscus transport. A meniscus interface ink transport model is proposed, and its general applicability is demonstrated by predicting the patterned dot radii of chemically diverse inks.

  20. A Data-Rich Recruitment Core to Support Translational Clinical Research

    PubMed Central

    Kost, Rhonda G.; Corregano, Lauren M.; Rainer, Tyler-Lauren; Melendez, Caroline; Coller, Barry S.

    2014-01-01

    Background Under-enrollment of clinical studies wastes resources and delays assessment of research discoveries. We describe the organization and impact of a centralized recruitment core delivering comprehensive recruitment support to investigators. Methods The Rockefeller University Center for Clinical and Translational Science supports a centralized recruitment core, call center, Research Volunteer Repository, data infrastructure, and staff who provide expert recruitment services to investigators. During protocol development, consultations aim to optimize enrollment feasibility, develop recruitment strategy, budget, and advertising. Services during study conduct include advertising placement, repository queries, call management, prescreening, referral, and visit scheduling. Utilization and recruitment outcomes are tracked using dedicated software. Results For protocols receiving recruitment services during 2009–2013: median time from initiation of recruitment to the first enrolled participant was 10 days; of 4,047 first-time callers to the call center, 92% (n=3722) enrolled in the Research Volunteer Repository, with 99% retention; 23% of Repository enrollees subsequently enrolled in ≥1 research studies, with 89% retention. Of volunteers referred by repository queries, 49% (280/537) enrolled into the study, with 92% retained. Conclusions Provision of robust recruitment infrastructure including expertise, a volunteer repository, data capture and real-time analysis accelerates protocol accrual. Application of recruitment science improves the quality of clinical investigation. PMID:25381717

  1. Studies on Normal and Microgravity Annular Two Phase Flows

    NASA Technical Reports Server (NTRS)

    Balakotaiah, V.; Jayawardena, S. S.; Nguyen, L. T.

    1999-01-01

    Two-phase gas-liquid flows occur in a wide variety of situations. In addition to normal gravity applications, such flows may occur in space operations such as active thermal control systems, power cycles, and storage and transfer of cryogenic fluids. Various flow patterns exhibiting characteristic spatial and temporal distribution of the two phases are observed in two-phase flows. The magnitude and orientation of gravity with respect to the flow has a strong impact on the flow patterns observed and on their boundaries. The identification of the flow pattern of a flow is somewhat subjective. The same two-phase flow (especially near a flow pattern transition boundary) may be categorized differently by different researchers. Two-phase flow patterns are somewhat simplified in microgravity, where only three flow patterns (bubble, slug and annular) have been observed. Annular flow is obtained for a wide range of gas and liquid flow rates, and it is expected to occur in many situations under microgravity conditions. Slug flow needs to be avoided, because vibrations caused by slugs result in unwanted accelerations. Therefore, it is important to be able to accurately predict the flow pattern which exists under given operating conditions. It is known that the wavy liquid film in annular flow has a profound influence on the transfer of momentum and heat between the phases. Thus, an understanding of the characteristics of the wavy film is essential for developing accurate correlations. In this work, we review our recent results on flow pattern transitions and wavy films in microgravity.

  2. Banded electromagnetic stator core

    DOEpatents

    Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

    1996-06-11

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figs.

  3. Banded electromagnetic stator core

    DOEpatents

    Fanning, Alan W.; Gonzales, Aaron A.; Patel, Mahadeo R.; Olich, Eugene E.

    1994-01-01

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

  4. Banded electromagnetic stator core

    DOEpatents

    Fanning, Alan W.; Gonzales, Aaron A.; Patel, Mahadeo R.; Olich, Eugene E.

    1996-01-01

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

  5. Banded electromagnetic stator core

    DOEpatents

    Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

    1994-04-05

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.

  6. Laser Doppler velocimeter measurements and laser sheet imaging in an annular combustor model. M.S. Thesis, Final Report

    NASA Technical Reports Server (NTRS)

    Dwenger, Richard Dale

    1995-01-01

    An experimental study was conducted in annular combustor model to provide a better understanding of the flowfield. Combustor model configurations consisting of primary jets only, annular jets only, and a combination of annular and primary jets were investigated. The purpose of this research was to provide a better understanding of combustor flows and to provide a data base for comparison with computational models. The first part of this research used a laser Doppler velocimeter to measure mean velocity and statistically calculate root-mean-square velocity in two coordinate directions. From this data, one Reynolds shear stress component and a two-dimensional turbulent kinetic energy term was determined. Major features of the flowfield included recirculating flow, primary and annular jet interaction, and high turbulence. The most pronounced result from this data was the effect the primary jets had on the flowfield. The primary jets were seen to reduce flow asymmetries, create larger recirculation zones, and higher turbulence levels. The second part of this research used a technique called marker nephelometry to provide mean concentration values in the combustor. Results showed the flow to be very turbulent and unsteady. All configurations investigated were highly sensitive to alignment of the primary and annular jets in the model and inlet conditions. Any imbalance between primary jets or misalignment of the annular jets caused severe flow asymmetries.

  7. Effects of Gravity on Bubble Formation in an Annular Jet

    NASA Technical Reports Server (NTRS)

    Koepp, R. A.; Parthasarathy, R. N.; Gollahalli, S. R.

    2004-01-01

    The effects of gravity on the bubble formation in an annular jet were studied. The experiments were conducted in the 2.2-second drop tower at the NASA Glenn Research Center. Terrestrial gravity experiments were conducted at the Fluid Dynamics Research Laboratory at the University of Oklahoma. Stainless steel tubing with inner diameters of 1/8" (gas inner annulus) and 5/16" (liquid outer annulus) served as the injector. A rectangular test section, 6" x 6" x 14" tall, made out of half-inch thick Lexan was used. Images of the annular jet were acquired using a high-speed camera. The effects of gravity and varying liquid and gas flow rates on bubble size, wavelength, and breakup length were documented. In general, the bubble diameter was found to be larger in terrestrial gravity than in microgravity for varying Weber numbers (0.05 - 0.16 and 5 - 11) and liquid flow rates (1.5 ft/s - 3.0 ft/s). The wavelength was found to be larger in terrestrial gravity than in microgravity, but remained constant for varying Weber numbers. For low Weber numbers (0.05 - 0.16), the breakup length in microgravity was significantly higher than in terrestrial gravity. Comparison with linear stability analysis showed estimated bubble sizes within 9% of experimental bubble sizes. Bubble size compared to other terrestrial gravity experiments with same flow conditions showed distinct differences in bubble size, which displayed the importance of injector geometry on bubble formation.

  8. Cretaceous shallow drilling, US Western Interior: Core research. Technical progress report

    SciTech Connect

    Arthur, M.A.

    1993-02-17

    This project is a continuing multidisciplinary study of middle to Upper Cretaceous marine carbonate and clastic rocks in the Utah-Colorado-Kansas corridor of the old Cretaceous seaway that extended from the Gulf Coast to the Arctic during maximum Cretaceous transgressions. It is collaborative between in the US Geological Survey (W.E. Dean, P.I.) and University researchers led by The Pennsylvania State University(M.A. Arthur, P.I.) and funded by DOE and the USGS, in part. Research focusses on the Greenhom, Niobrara and lower Pierre Shale units and their equivalents, combining biostratigraphic/paleoecologic studies, inorganic, organic and stable isotopic geochemical studies, mineralogical investigations and high-resolution geophysical logging. This research requires unweathered samples and continuous smooth ``exposures`` in the form of cores from at least 4 relatively shallow reference holes (i.e. < 1000m) in transect from east to west across the basin. The major initial effort was recovery in Year 1 of the project of continuous cores from each site in the transect. This drilling provided samples and logs of strata ranging from pelagic sequences that contain organic-carbon-rich marine source rocks to nearshore coal-bearing units. This transect also will provide information on the extent of thermal maturation and migration of hydrocarbons in organic-carbon-rich strata along a burial gradient.

  9. More Lessons Learned from Research, Volume 1: Useful and Usable Research Related to Core Mathematical Practices

    ERIC Educational Resources Information Center

    Silver, Edward A., Ed.; Kenney, Patricia Ann, Ed.

    2015-01-01

    This book's 28 chapters are adapted and updated from articles published in NCTM's "Journal for Research in Mathematics Education" between 2000 and 2010. The authors have rewritten and revised their work to make it clear, understandable, and--most of all--useful for mathematics teachers today. To help teachers even more, these articles…

  10. Development of an Advanced Annular Combustor

    NASA Technical Reports Server (NTRS)

    Rusnak, J. P.; Shadowen, J. H.

    1969-01-01

    The objective of the effort described in this report was to determine the structural durability of a full-scale advanced annular turbojet combustor using ASTM A-1 type fuel and operating at conditions typical of advanced supersonic aircraft. A full-scale annular combustor of the ram-induction type was fabricated and subjected to a 325-hour cyclic endurance test at conditions representative of operation in a Mach 3.0 aircraft. The combustor exhibited extensive cracking and scoop burning at the end of the test program. But these defects had no appreciable effect on combustor performance, as performance remained at a high level throughout the endurance program. Most performance goals were achieved with pressure loss values near 6% and 8%, and temperature rise variation ratio (deltaTVR) values near 1.25 and l.22 at takeoff and cruise conditions, respectively. Combustion efficiencies approached l004 and the exit radial temperature profiles were approximately as desired.

  11. LDV Measurements in an Annular Combustor Model

    NASA Technical Reports Server (NTRS)

    Barron, Dean A.

    1996-01-01

    This thesis covers the design and setup of a laser doppler velocimeter (LDV) system used to take velocity measurements in an annular combustor model. The annular combustor model is of contemporary design using 60 degree flat vane swirlers, producing a strong recirculation zone. Detailed measurements are taken of the swirler inlet air flow and of the downstream enclosed swirling flow. The laser system used is a two color, two component system set up in forward scatter. Detailed are some of the special considerations needed for LDV use in the confined turbulent flow of the combustor model. LDV measurements in a single swirler rig indicated that the flow changes radically in the first duct height. After this, a flow profile is set up and remains constant in shape. The magnitude of the velocities gradually decays due to viscous damping.

  12. LABORATORY AND NUMERICAL INVESTIGATIONS OF RESIDENCE TIME DISTRIBUTION OF FLUIDS IN LAMINAR FLOW STIRRED ANNULAR PHOTOREACTOR

    EPA Science Inventory

    Laboratory and Numerical Investigations of Residence Time Distribution of Fluids in Laminar Flow Stirred Annular Photoreactor

    E. Sahle-Demessie1, Siefu Bekele2, U. R. Pillai1

    1U.S. EPA, National Risk Management Research Laboratory
    Sustainable Technology Division,...

  13. Flow visualization study of post critical heat flux region for inverted bubbly, slug and annular flow regimes

    SciTech Connect

    Denten, J.G.; Ishii, M.

    1988-11-01

    A visual study of film boiling using still photographic and high- speed motion picture methods was carried out in order to analyze the post-CHF hydrodynamics for steady-state inlet pre-CHF two-phase flow regimes. Pre-CHF two-phase flow regimes were established by introducing Freon 113 liquid and nitrogen gas into a jet core injection nozzle. An idealized, post-CHF two-phase core initial flow geometry (cylindrical multiphase jet core surrounded by a coaxial annulus of gas) was established at the nozzle exit by introducing nitrogen gas into the annular gap between the jet nozzle two-phase effluent and the heated test section inlet. For the present study three basic post-CHF flow regimes have been observed: the rough wavy regime (inverted annular flow preliminary break down), the agitated regime (transition between inverted annular and dispersed droplet flow), and the dispersed ligament/droplet regime. For pre-CHF bubbly flow in the jet nozzle, the post-CHF flow (beginning from jet nozzle exit/heated test section inlet) consists of the rough wavy regime, followed by the agitated and then the dispersed ligament/droplet regime. In the same way, for pre-CHF slug flow in the jet core, the post-CHF flow is comprised of the agitated regime at the nozzle exit, followed by the dispersed regime. Pre-CHF annular jet core flow results in a small, depleted post-CHF agitated flow regime at the nozzle exit, immediately followed by the dispersed ligament/droplet regime. Observed post dryout hydrodynamic behavior is reported, with particular attention given to the transition flow pattern between inverted annular and dispersed droplet flow. 43 refs., 20 figs., 5 tabs.

  14. Performance of annular high frequency thermoacoustic engines

    NASA Astrophysics Data System (ADS)

    Rodriguez, Ivan A.

    This thesis presents studies of the behavior of miniature annular thermoacoustic prime movers and the imaging of the complex sound fields using PIV inside the small acoustic wave guides when driven by a temperature gradient. Thermoacoustic engines operating in the standing wave mode are limited in their acoustic efficiency by a high degree of irreversibility that is inherent in how they work. Better performance can be achieved by using traveling waves in the thermoacoustic devices. This has led to the development of an annular high frequency thermoacoustic prime mover consisting of a regenerator, which is a random stack in-between a hot and cold heat exchanger, inside an annular waveguide. Miniature devices were developed and studied with operating frequencies in the range of 2-4 kHz. This corresponds to an average ring circumference of 11 cm for the 3 kHz device, the resonator bore being 6 mm. A similar device of 11 mm bore, length of 18 cm was also investigated; its resonant frequency was 2 kHz. Sound intensities as high as 166.8 dB were generated with limited heat input. Sound power was extracted from the annular structure by an impedance-matching side arm. The nature of the acoustic wave generated by heat was investigated using a high speed PIV instrument. Although the acoustic device appears symmetric, its performance is characterized by a broken symmetry and by perturbations that exist in its structure. Effects of these are observed in the PIV imaging; images show axial and radial components. Moreover, PIV studies show effects of streaming and instabilities which affect the devices' acoustic efficiency. The acoustic efficiency is high, being of 40% of Carnot. This type of device shows much promise as a high efficiency energy converter; it can be reduced in size for microcircuit applications.

  15. Annular and Total Solar Eclipses of 2003

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, Jay

    2002-01-01

    On Saturday, 2003 May 31, an annular eclipse of the Sun will be visible from a broad corridor that traverses the North Atlantic. The path of the Moon's antumbral shadow begins in northern Scotland, crosses Iceland and central Greenland, and ends at sunrise in Baffin Bay (Canada). A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes most of Europe, the Middle East, central and northern Asia, and northwestern North America. The trajectory of the Moon's shadow is quite unusual during this event. The shadow axis passes to the far north where it barely grazes Earth's surface. In fact, the northern edge of the antumbra actually misses Earth so that one path limit is defined by the day/night terminator rather than by the shadow's upper edge. As a result, the track of annularity has a peculiar "D" shape that is nearly 1200 kilometers wide. Since the eclipse occurs just three weeks prior to the northern summer solstice, Earth's northern axis is pointed sunwards by 22.8 deg. As seen from the Sun, the antumbral shadow actually passes between the North Pole and the terminator. As a consequence of this extraordinary geometry, the path of annularity runs from east to west rather than the more typical west to east. The event transpires near the Moon's ascending node in Taurus five degrees north of Aldebaran. Since apogee occurs three days earlier (May 28 at 13 UT), the Moon's apparent diameter (29.6 arc-minutes) is still too small to completely cover the Sun (31.6 arc-minutes) resulting in an annular eclipse.

  16. Neoclassical transport in an annular penning trap

    SciTech Connect

    Robertson, S.

    1997-07-01

    A modified Penning trap is described with an annular confinement region and a toroidal magnetic field. A non-neutral electron plasma is confined axially by an electrostatic field and, in the radial direction, particles are constrained to lie within a small drift distance of a cylindrical flux surface. Drift orbits of all particles are banana-shaped and collisions cause neoclassical transport. {copyright} {ital 1997 American Institute of Physics.}

  17. The Annular Suspension and Pointing System /ASPS/

    NASA Technical Reports Server (NTRS)

    Anderson, W. W.; Woolley, C. T.

    1978-01-01

    The Annular Suspension and Pointing System (ASPS) may be attached to a carrier vehicle for orientation, mechanical isolation, and fine pointing purposes applicable to space experiments. It has subassemblies for both coarse and vernier pointing. A fourteen-degree-of-freedom simulation of the ASPS mounted on a Space Shuttle has yielded initial performance data. The simulation describes: the magnetic actuators, payload sensors, coarse gimbal assemblies, control algorithms, rigid body dynamic models of the payload and Shuttle, and a control system firing model.

  18. Endoscopic measurements using a panoramic annular lens

    NASA Technical Reports Server (NTRS)

    Gilbert, John A.; Matthys, Donald R.

    1992-01-01

    The objective of this project was to design, build, demonstrate, and deliver a prototype system for making measurements within cavities. The system was to utilize structured lighting as the means for making measurements and was to rely on a stationary probe, equipped with a unique panoramic annular lens, to capture a cylindrical view of the illuminated cavity. Panoramic images, acquired with a digitizing camera and stored in a desk top computer, were to be linearized and analyzed by mouse-driven interactive software.

  19. Annular feed air breathing fuel cell stack

    DOEpatents

    Wilson, Mahlon S.; Neutzler, Jay K.

    1997-01-01

    A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. The fuel distribution manifold is formed from a hydrophilic-like material to redistribute water produced by fuel and oxygen reacting at the cathode. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

  20. Vibration analysis of annular-like plates

    NASA Astrophysics Data System (ADS)

    Cheng, L.; Li, Y. Y.; Yam, L. H.

    2003-05-01

    The existence of eccentricity of the central hole for an annular plate results in a significant change in the natural frequencies and mode shapes of the structure. In this paper, the vibration analysis of annular-like plates is presented based on numerical and experimental approaches. Using the finite element analysis code Nastran, the effects of the eccentricity, hole size and boundary condition on vibration modes are investigated systematically through both global and local analyses. The results show that analyses for perfect symmetric conditions can still roughly predict the mode shapes of "recessive" modes of the plate with a slightly eccentric hole. They will, however, lead to erroneous results for "dominant" modes. In addition, the residual displacement mode shape is verified as an effective parameter for identifying damage occurring in plate-like structures. Experimental modal analysis on a clamped-free annular-like plate is performed, and the results obtained reveal good agreement with those obtained by numerical analysis. This study provides guidance on modal analysis, vibration measurement and damage detection of plate-like structures.

  1. Hydrodynamic performance of an annular liquid jet: Production of spherical shells

    NASA Technical Reports Server (NTRS)

    Kendall, J. M.

    1982-01-01

    An annular jet flow of liquid surrounding a flow of gas at its core is extremely unstable. Axisymmetric oscillations arise spontaneously, and grow with such rapidity along the axial dimension that a pinch-off of the liquid and an encapsulation of the core gas occurs within as few as four jet diameters. The shells which result thereby may be described as thick-wall bubbles, for which van der Waals forces are unimportant. A description is given of the fluid dynamic processes by which the shells are formed, and of means for preserving and promoting the geometrical of the product. The forming of metallic shells is mentioned.

  2. Fast reactor core concepts to improve transmutation efficiency

    SciTech Connect

    Fujimura, Koji; Kawashima, Katsuyuki; Itooka, Satoshi

    2015-12-31

    Fast Reactor (FR) core concepts to improve transmutation efficiency were conducted. A heterogeneous MA loaded core was designed based on the 1000MWe-ABR breakeven core. The heterogeneous MA loaded core with Zr-H loaded moderated targets had a better transmutation performance than the MA homogeneous loaded core. The annular pellet rod design was proposed as one of the possible design options for the MA target. It was shown that using annular pellet MA rods mitigates the self-shielding effect in the moderated target so as to enhance the transmutation rate.

  3. MULTI-CORE AND OPTICAL PROCESSOR RELATED APPLICATIONS RESEARCH AT OAK RIDGE NATIONAL LABORATORY

    SciTech Connect

    Barhen, Jacob; Kerekes, Ryan A; ST Charles, Jesse Lee; Buckner, Mark A

    2008-01-01

    High-speed parallelization of common tasks holds great promise as a low-risk approach to achieving the significant increases in signal processing and computational performance required for next generation innovations in reconfigurable radio systems. Researchers at the Oak Ridge National Laboratory have been working on exploiting the parallelization offered by this emerging technology and applying it to a variety of problems. This paper will highlight recent experience with four different parallel processors applied to signal processing tasks that are directly relevant to signal processing required for SDR/CR waveforms. The first is the EnLight Optical Core Processor applied to matched filter (MF) correlation processing via fast Fourier transform (FFT) of broadband Dopplersensitive waveforms (DSW) using active sonar arrays for target tracking. The second is the IBM CELL Broadband Engine applied to 2-D discrete Fourier transform (DFT) kernel for image processing and frequency domain processing. And the third is the NVIDIA graphical processor applied to document feature clustering. EnLight Optical Core Processor. Optical processing is inherently capable of high-parallelism that can be translated to very high performance, low power dissipation computing. The EnLight 256 is a small form factor signal processing chip (5x5 cm2) with a digital optical core that is being developed by an Israeli startup company. As part of its evaluation of foreign technology, ORNL's Center for Engineering Science Advanced Research (CESAR) had access to a precursor EnLight 64 Alpha hardware for a preliminary assessment of capabilities in terms of large Fourier transforms for matched filter banks and on applications related to Doppler-sensitive waveforms. This processor is optimized for array operations, which it performs in fixed-point arithmetic at the rate of 16 TeraOPS at 8-bit precision. This is approximately 1000 times faster than the fastest DSP available today. The optical core

  4. Technical basis in support of the conversion of the University of Missouri Research Reactor (MURR) core from highly-enriched to low-enriched uranium - core neutron physics

    SciTech Connect

    Stillman, J.; Feldman, E.; Foyto, L; Kutikkad, K; McKibben, J C; Peters, N.; Stevens, J.

    2012-09-01

    This report contains the results of reactor design and performance for conversion of the University of Missouri Research Reactor (MURR) from the use of highly-enriched uranium (HEU) fuel to the use of low-enriched uranium (LEU) fuel. The analyses were performed by staff members of the Global Threat Reduction Initiative (GTRI) Reactor Conversion Program at the Argonne National Laboratory (ANL) and the MURR Facility. The core conversion to LEU is being performed with financial support of the U. S. government.

  5. Heat Transfer and Pressure Drop in Concentric Annular Flows of Binary Inert Gas Mixtures

    NASA Technical Reports Server (NTRS)

    Reid, R. S.; Martin, J. J.; Yocum, D. J.; Stewart, E. T.

    2007-01-01

    Studies of heat transfer and pressure drop of binary inert gas mixtures flowing through smooth concentric circular annuli, tubes with fully developed velocity profiles, and constant heating rate are described. There is a general lack of agreement among the constant property heat transfer correlations for such mixtures. No inert gas mixture data exist for annular channels. The intent of this study was to develop highly accurate and benchmarked pressure drop and heat transfer correlations that can be used to size heat exchangers and cores for direct gas Brayton nuclear power plants. The inside surface of the annular channel is heated while the outer surface of the channel is insulated. Annulus ratios range 0.5 < r* < 0.83. These smooth tube data may serve as a reference to the heat transfer and pressure drop performance in annuli, tubes, and channels having helixes or spacer ribs, or other surfaces.

  6. Functional specifications of the annular suspension pointing system, appendix A

    NASA Technical Reports Server (NTRS)

    Edwards, B.

    1980-01-01

    The Annular Suspension Pointing System is described. The Design Realization, Evaluation and Modelling (DREAM) system, and its design description technique, the DREAM Design Notation (DDN) is employed.

  7. Characterization and quantification of an in-core neutron irradiation facility at a TRIGA II research reactor

    NASA Astrophysics Data System (ADS)

    Aghara, Sukesh; Charlton, William

    2006-07-01

    Experiments have been performed to characterize the neutron environment at an in-core TRIGA type nuclear research reactor. Steady-state thermal and epithermal neutron environment testing is important for many applications including, materials, electronics and biological cells. A well characterized neutron environment at a research reactor, including energy spectrum and spatial distribution, can be useful to many research communities and for educational research. This paper describes the characterization process and an application of exposing electronics to high neutron fluence.

  8. Wave turbulence in annular wave tank

    NASA Astrophysics Data System (ADS)

    Onorato, Miguel; Stramignoni, Ettore

    2014-05-01

    We perform experiments in an annular wind wave tank at the Dipartimento di Fisica, Universita' di Torino. The external diameter of the tank is 5 meters while the internal one is 1 meter. The tank is equipped by two air fans which can lead to a wind of maximum 5 m/s. The present set up is capable of studying the generation of waves and the development of wind wave spectra for large duration. We have performed different tests including different wind speeds. For large wind speed we observe the formation of spectra consistent with Kolmogorv-Zakharov predictions.

  9. Seeing double: annular diaper rash in twins.

    PubMed

    Sommer, Lacy L; Manders, Steven M

    2015-01-01

    We report a case of dichorionic, diamniotic twins who developed similar erythematous, annular, erosive plaques in the inguinal folds in the first few weeks of life that were refractory to topical antifungals and oral antibiotics. The twins were found to have high transaminase levels, antinuclear antibody positivity, and anti-SSS/Ro) and anti-SSB/La autoantibodies. The rash resolved without scarring by 7 months of age with the use of low-potency topical corticosteroids. We suggest that physicians consider neonatal lupus erythematosus in neonates with atypical eruptions occurring in sun-protected skin.

  10. Annular lupus vulgaris mimicking tinea cruris.

    PubMed

    Heo, Young Soo; Shin, Won Woong; Kim, Yong Ju; Song, Hae Jun; Oh, Chil Hwan

    2010-05-01

    Cutaneous tuberculosis is an infrequent form of extrapulmonary tuberculosis. It is often clinically and histopathologically confused with various cutaneous disorders. A 36-year-old man attended our clinic with slowly progressive, asymptomatic, annular skin lesions on both the thighs and buttocks for 10 years. He consulted with many physicians and was improperly treated with an oral antifungal agent for several months under the diagnosis of tinea cruris, but no resolution of his condition was observed. A diagnosis of lupus vulgaris was made based on the histopathologic examination and the polymerase chain reaction assay. Anti-tuberculosis therapy was administered and the lesions started to regress.

  11. Finite stretching of an annular plate.

    NASA Technical Reports Server (NTRS)

    Biricikoglu, V.; Kalnins, A.

    1971-01-01

    The problem of the finite stretching of an annular plate which is bonded to a rigid inclusion at its inner edge is considered. The material is assumed to be isotropic and incompressible with a Mooney-type constitutive law. It is shown that the inclusion of the effect of the transverse normal strain leads to a rapid variation in thickness which is confined to a narrow edge zone. The explicit solutions to the boundary layer equations, which govern the behavior of the plate near the edges, are presented.

  12. Mass transport in annular spherical system

    NASA Astrophysics Data System (ADS)

    Bauer, Helmut F.

    The mass transport between two concentric spheres with inlet and outlet at the poles was determined for ideal liquid flow (plug flow) and laminar flow for constant concentration at the spherical walls and constant concentration at the inlet. Velocity distribution and local concentration profiles were determined analytically for various widths of the annular spherical conduit and various diffusive flow parameters. It is found that with the increase of this parameter, the decay becomes quite rapid and that the same effect occurs for increasing diameter ratio of the spheres. This configuration may possibly be used as a basic element of an artificial kidney.

  13. Duration test of an annular colloid thruster.

    NASA Technical Reports Server (NTRS)

    Perel, J.; Mahoney, J. F.; Daley, H. L.

    1972-01-01

    An annular colloid thruster was continuously operated for 1023 hours. Performance was stable with no sparking and negligible drain currents observed. An average thrust of 25.1 micropounds and an average specific impulse of 1160 seconds were obtained at an accelerating voltage of 15 k he thruster exhaust beam was continuously neutralized using electrons and electrostatic vectoring was demonstrated periodically. The only clear trend with time was an increase in specific impulse during the last third of the test period. From these results the thruster lifetime was estimated to be over an order of magnitude greater than the test duration.

  14. Optical manipulation using optimal annular vortices.

    PubMed

    Paez-Lopez, Rafael; Ruiz, Ulises; Arrizon, Victor; Ramos-Garcia, Ruben

    2016-09-01

    We discuss a simple method to generate a configurable annular vortex beam (AVB) with the maximum possible peak intensity, employing a phase hologram whose transmittance is the phase of a Bessel beam. Due to its maximum intensity, the AVB provides the optimal density of the orbital angular moment. Another attribute of the generated AVB is the relatively high invariance of the intensity profile when the topological charge is changed. We demonstrate the advantages and flexibility of these AVBs for optical trapping applications. PMID:27607992

  15. The Annular Momentum Control Device (AMCD)

    NASA Technical Reports Server (NTRS)

    Anderson, W. W.; Groom, N. J.

    1975-01-01

    An annular momentum control device consisting principally of a spinning rim, a set of noncontacting magnetic bearings for supporting the rim, a noncontacting electric motor for driving the rim, and, for some applications, one or more gimbals is described. The device is intended for applications where requirements for control torque and momentum storage exist. Hardware requirements and potential unit configurations are discussed. Theoretical considerations for the passive use of the device are discussed. Potential applications of the device in other than passive configurations for the attitude control, stabilization, and maneuvering of spacecraft are reported.

  16. Endoscopic inspection using a panoramic annular lens

    NASA Technical Reports Server (NTRS)

    Gilbert, John A.; Matthys, Donald R.

    1991-01-01

    The objective of this one year study was to design, build, and demonstrate a prototype system for cavity inspection. A cylindrical view of the cavity interior was captured in real time through a compound lens system consisting of a unique panoramic annular lens and a collector lens. Images, acquired with a digitizing camera and stored in a desktop computer, were manipulated using image processing software to aid in visual inspection and qualitative analysis. A detailed description of the lens and its applications is given.

  17. Theoretical and experimental study of inverted annular film boiling and regime transition during reflood transients

    NASA Astrophysics Data System (ADS)

    Mohanta, Lokanath

    The Loss of Coolant Accident (LOCA) is a design basis accident for light water reactors that usually determines the limits on core power. During a LOCA, film boiling is the dominant mode of heat transfer prior to the quenching of the fuel rods. The study of film boiling is important because this mode of heat transfer determines if the core can be safely cooled. One important film boiling regime is the so-called Inverted Annular Film Boiling (IAFB) regime which is characterized by a liquid core downstream of the quench front enveloped by a vapor film separating it from the fuel rod. Much research have been conducted for IAFB, but these studies have been limited to steady state experiments in single tubes. In the present work, subcooled and saturated IAFB are investigated using high temperature reflood data from the experiments carried out in the Rod Bundle Heat Transfer (RBHT) test facility. Parametric effects of system parameters including the pressure, inlet subcooling, and flooding rate on the heat transfer are investigated. The heat transfer behavior during transition to Inverted Slug Film Boiling (ISFB) regime is studied and is found to be different than that reported in previous studies. The effects of spacer grids on heat transfer in the IAFB and ISFB regimes are also presented. Currently design basis accidents are evaluated with codes in which heat transfer and wall drag must be calculated with local flow parameters. The existing models for heat transfer are applicable up to a void fraction of 0.6, i.e. in the IAFB regime and there is no heat transfer correlation for ISFB. A new semi-empirical heat transfer model is developed covering the IAFB and ISFB regimes which is valid for a void fraction up to 90% using the local flow variables. The mean absolute percentage error in predicting the RBHT data is 11% and root mean square error is 15%. This new semi-empirical model is found to compare well with the reflood data of FLECHT-SEASET experiments as well as data

  18. Common Core State Standards Alignment: Advanced Placement[R]. Research Report 2011-8

    ERIC Educational Resources Information Center

    Hart, Beth; Carman, Elaine; Luisier, Danielle; Vasavada, Natasha

    2011-01-01

    The College Board has been a strong advocate for and played an active role in the development of the Common Core State Standards. As part of this collaboration, the College Board helped draft the standards and helped shape the initiative by providing executive guidance on the Common Core Advisory Committee. The goal of the Common Core State…

  19. Neutronic and thermal-hydraulic analysis of new irradiation channels inside the Moroccan TRIGA Mark II research reactor core.

    PubMed

    Chham, E; El Bardouni, T; Benaalilou, K; Boukhal, H; El Bakkari, B; Boulaich, Y; El Younoussi, C; Nacir, B

    2016-10-01

    This study was conducted to improve the capacity of radioisotope production in the Moroccan TRIGA Mark II research reactor, which is considered as one of the most important applications of research reactors. The aim of this study is to enhance the utilization of TRIGA core in the field of neutron activation and ensure an economic use of the fuel. The main idea was to create an additional irradiation channel (IC) inside the core. For this purpose, three new core configurations are proposed, which differ according to the IC position in the core. Thermal neutron flux distribution and other neutronic safety parameters such as power peaking factors, excess reactivity, and control rods worth reactivity were calculated using the Monte Carlo N-Particle Transport (MCNP) code and neutron cross-section library based on ENDF/B-VII evaluation. The calculated thermal flux in the central thimble (CT) and in the added IC for the reconfigured core is compared with the thermal flux in the CT of the existing core, which is taken as a reference. The results show that all the obtained fluxes in CTs are very close to the reference value, while a remarkable difference is observed between the fluxes in the new ICs and reference. This difference depends on the position of IC in the reactor core. To demonstrate that the Moroccan TRIGA reactor could safely operate at 2MW, with new configurations based on new ICs, different safety-related thermal-hydraulic parameters were investigated. The PARET model was used in this study to verify whether the safety margins are met despite the new modifications of the core. The results show that it is possible to introduce new ICs safely in the reactor core, because the obtained values of the parameters are largely far from compromising the safety of the reactor. PMID:27552124

  20. Neutronic and thermal-hydraulic analysis of new irradiation channels inside the Moroccan TRIGA Mark II research reactor core.

    PubMed

    Chham, E; El Bardouni, T; Benaalilou, K; Boukhal, H; El Bakkari, B; Boulaich, Y; El Younoussi, C; Nacir, B

    2016-10-01

    This study was conducted to improve the capacity of radioisotope production in the Moroccan TRIGA Mark II research reactor, which is considered as one of the most important applications of research reactors. The aim of this study is to enhance the utilization of TRIGA core in the field of neutron activation and ensure an economic use of the fuel. The main idea was to create an additional irradiation channel (IC) inside the core. For this purpose, three new core configurations are proposed, which differ according to the IC position in the core. Thermal neutron flux distribution and other neutronic safety parameters such as power peaking factors, excess reactivity, and control rods worth reactivity were calculated using the Monte Carlo N-Particle Transport (MCNP) code and neutron cross-section library based on ENDF/B-VII evaluation. The calculated thermal flux in the central thimble (CT) and in the added IC for the reconfigured core is compared with the thermal flux in the CT of the existing core, which is taken as a reference. The results show that all the obtained fluxes in CTs are very close to the reference value, while a remarkable difference is observed between the fluxes in the new ICs and reference. This difference depends on the position of IC in the reactor core. To demonstrate that the Moroccan TRIGA reactor could safely operate at 2MW, with new configurations based on new ICs, different safety-related thermal-hydraulic parameters were investigated. The PARET model was used in this study to verify whether the safety margins are met despite the new modifications of the core. The results show that it is possible to introduce new ICs safely in the reactor core, because the obtained values of the parameters are largely far from compromising the safety of the reactor.

  1. Annular and Total Solar Eclipses of 2010

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, J.

    2008-01-01

    While most NASA eclipse bulletins cover a single eclipse, this publication presents predictions for two solar eclipses during 2010. This has required a different organization of the material into the following sections. Section 1 -- Eclipse Predictions: The section consists of a general discussion about the eclipse path maps, Besselian elements, shadow contacts, eclipse path tables, local circumstances tables, and the lunar limb profile. Section 2 -- Annular Solar Eclipse of 2010 Ja n 15: The section covers predictions and weather prospects for the annular eclipse. Section 3 -- Total Solar Eclipse of 2010 Jul 11: The se ction covers predictions and weather prospects for the total eclipse. Section 4 -- Observing Eclipses: The section provides information on eye safety, solar filters, eclipse photography, and making contact timings from the path limits. Section 5 -- Eclipse Resources: The final section contains a number of resources including information on the IAU Working Group on Eclipses, the Solar Eclipse Mailing List, the NASA eclipse bulletins on the Internet, Web sites for the two 2010 eclipses, and a summary identifying the algorithms, ephemerides, and paramete rs used in the eclipse predictions.

  2. Detonation diffraction from an annular channel

    NASA Astrophysics Data System (ADS)

    Meredith, James; Ng, Hoi Dick; Lee, John H. S.

    2010-12-01

    In this study, gaseous detonation diffraction from an annular channel was investigated with a streak camera and the critical pressure for transmission of the detonation wave was obtained. The annular channel was used to approximate an infinite slot resulting in cylindrically expanding detonation waves. Two mixtures, stoichiometric acetylene-oxygen and stoichiometric acetylene-oxygen with 70% Ar dilution, were tested in a 4.3 and 14.3 mm channel width ( W). The undiluted and diluted mixtures were found to have values of the critical channel width over the cell size around 3 and 12 respectively. Comparing these results to values of the critical diameter ( d c ), in which a spherical detonation occurs, a value of critical d c / W c near 2 is observed for the highly diluted mixture. This value corresponds to the geometrical factor of the curvature term between a spherical and cylindrical diverging wave. Hence, the result is in support of Lee's proposed mechanism [Lee in Dynamics of Exothermicity, pp. 321, Gordon and Breach, Amsterdam, 1996] for failure due to diffraction based on curvature in stable mixtures such as those highly argon diluted with very regular detonation cellular patterns.

  3. Annular beam shaping and optical trepanning

    NASA Astrophysics Data System (ADS)

    Zeng, Danyong

    Percussion drilling and trepanning are two laser drilling methods. Percussion drilling is accomplished by focusing the laser beam to approximately the required diameter of the hole, exposing the material to one or a series of laser pulses at the same spot to melt and vaporize the material. Drilling by trepanning involves cutting a hole by rotating a laser beam with an optical element or an x-y galvo-scanner. Optical trepanning is a new laser drilling method using an annular beam. The annular beams allow numerous irradiance profiles to supply laser energy to the workpiece and thus provide more flexibility in affecting the hole quality than a traditional circular laser beam. Heating depth is important for drilling application. Since there are no good ways to measure the temperature inside substrate during the drilling process, an analytical model for optical trepanning has been developed by considering an axisymmetric, transient heat conduction equation, and the evolutions of the melting temperature isotherm, which is referred to as the melt boundary in this study, are calculated to investigate the influences of the laser pulse shapes and intensity profiles on the hole geometry. This mathematical model provides a means of understanding the thermal effect of laser irradiation with different annular beam shapes. To take account of conduction in the solid, vaporization and convection due to the melt flow caused by an assist gas, an analytical two-dimensional model is developed for optical trepanning. The influences of pulse duration, laser pulse length, pulse repetition rate, intensity profiles and beam radius are investigated to examine their effects on the recast layer thickness, hole depth and taper. The ray tracing technique of geometrical optics is employed to design the necessary optics to transform a Gaussian laser beam into an annular beam of different intensity profiles. Such profiles include half Gaussian with maximum intensities at the inner and outer

  4. Controlling the pressure within an annular volume of a wellbore

    DOEpatents

    Hermes, Robert E.; Gonzalez, Manuel E.; Llewellyn, Brian C.; Bloys, James B.

    2011-01-18

    A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

  5. Controlling the pressure within an annular volume of a wellbore

    DOEpatents

    Hermes, Robert E.; Gonzalez, Manuel E.; Llewellyn, Brian C.; Bloys, James B.; Coates, Don M.

    2011-06-21

    A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

  6. Controlling the pressure within an annular volume of a wellbore

    DOEpatents

    Hermes, Robert E.; Gonzalez, Manuel E.; Llewellyn, Brian C.; Bloys, James B.

    2010-06-29

    A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

  7. Controlling the pressure within an annular volume of a wellbore

    DOEpatents

    Hermes, Robert E.; Gonzalez, Manuel E.; Llewellyn, Brian C.; Bloys, James B.

    2008-10-28

    A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

  8. Controlling the pressure within an annular volume of a wellbore

    DOEpatents

    Hermes, Robert E.; Gonzalez, Manuel E.; Llewellyn, Brian C.; Bloys, James B.; Coates, Don M.

    2011-05-31

    A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

  9. Common Core Curriculum for Vocational Education. Category G: Evaluation and Research. G-5: Development of a Research Proposal in Vocational Education.

    ERIC Educational Resources Information Center

    Moshier, Kenneth

    This module on the development of a research proposal in vocational education is one of a set of five on evaluation and research and is part of a larger series of thirty-four modules constituting a core curriculum for use in the professional preparation of vocational educators in the areas of agricultural, business, home economics, and industrial…

  10. Eccentric annular crack under general nonuniform internal pressure

    NASA Astrophysics Data System (ADS)

    Moeini-Ardakani, S.; Kamali, M. T.; Shodja, H. M.

    2016-08-01

    For a better approximation of ring-shaped and toroidal cracks, a new eccentric annular crack model is proposed and an analytical approach for determination of the corresponding stress intensity factors is given. The crack is subjected to arbitrary mode I loading. A rigorous solution is provided by mapping the eccentric annular crack to a concentric annular crack. The analysis leads to two decoupled Fredholm integral equations of the second kind. For the sake of verification, the problem of a conventional annular crack is examined. Furthermore, for various crack configurations of an eccentric annular crack under uniform tension, the stress intensity factors pertaining to the inner and outer crack edges are delineated in dimensionless plots.

  11. Virtual cathode microwave generator having annular anode slit

    SciTech Connect

    Kwan, T.J.T.; Snell, C.M.

    1988-03-08

    A microwave generator using an oscillating virtual cathode is described comprising: a cathode for emitting electrons; an anode for accelerating emitted electrons from the cathode, the anode having an annular slit therethrough effective for forming the virtual cathode and having at least one range thickness relative to electrons reflected from the virtual cathode; and magnet means for producing a magnetic field having a field strength effective to form an annular beam from the emitted electrons in substantial alignment with the annular anode slit and to enable the electrons reflected from the virtual cathode to axially diverge from the annular beam. The reflected electrons return toward the cathode diverge from the annular beam and are absorbed by the anode to substantially eliminate electrons reflexing between the cathode and the virtual cathode.

  12. Acoustic modal analysis of a full-scale annular combustor

    NASA Technical Reports Server (NTRS)

    Karchmer, A. M.

    1982-01-01

    An acoustic modal decomposition of the measured pressure field in a full scale annular combustor installed in a ducted test rig is described. The modal analysis, utilizing a least squares optimization routine, is facilitated by the assumption of randomly occurring pressure disturbances which generate equal amplitude clockwise and counter-clockwise pressure waves, and the assumption of statistical independence between modes. These assumptions are fully justified by the measured cross spectral phases between the various measurement points. The resultant modal decomposition indicates that higher order modes compose the dominant portion of the combustor pressure spectrum in the range of frequencies of interest in core noise studies. A second major finding is that, over the frequency range of interest, each individual mode which is present exists in virtual isolation over significant portions of the spectrum. Finally, a comparison between the present results and a limited amount of data obtained in an operating turbofan engine with the same combustor is made. The comparison is sufficiently favorable to warrant the conclusion that the structure of the combustor pressure field is preserved between the component facility and the engine.

  13. Research on the Intrinsic Relationship of Customer Value and Corporate Core Competence

    NASA Astrophysics Data System (ADS)

    Ji, Guoping

    The article defined customer value and corporate core competence using induction method and described the characteristics of these two concepts. Then the author analyzed the intrinsic relationship of customer value and corporate core competence via the survey and case analysis methods. The author found that customer value was the basic point to cultivate corporate core competence which was the platform to achieve customer value. The article is of great help to provide some ideas of cultivating and developing corporate core competence based on customer value.

  14. Mineral Physics Research on Earth's Core and UTeach Outreach Activities at UT Austin

    NASA Astrophysics Data System (ADS)

    Lin, J.; Wheat, A. J.

    2011-12-01

    Comprehension of the alloying effects of major candidate light elements on the phase diagram and elasticity of iron addresses pressing issues on the composition, thermal structures, and seismic features of the Earth's core. Integrating this mineral physics research with the educational objectives of the CAREER award was facilitated by collaboration with the University of Texas at Austin's premier teaching program, UTeach. The UTeach summer outreach program hosts three one-week summer camps every year exposing K-12th graders to university level academia, emphasizing math and science initiatives and research. Each week of the camp either focuses on math, chemistry, or geology. Many of the students were underrepresented minorities and some required simultaneous translation; this is an effect of the demographics of the region, and caused some language barrier challenges. The students' opportunity to see first-hand what it is like to be on a university campus, as well as being in a research environment, such as the mineral physics lab, helps them to visualize themselves in academia in the future. A collection of displayable materials with information about deep-Earth research were made available to participating students and teachers to disseminate accurate scientific knowledge and enthusiasm. These items included a diamond anvil cell and diagrams of the diamond crystal structure, the layers of the Earth, and the phases of carbon to show that one element can have very different physical properties purely based on differences in structure. The students learned how advanced X-ray and optical laser spectroscopies are used to study properties of planetary materials in the diamond anvil cell. Stress was greatly placed on the basic mathematical relationship between force, area, and pressure, the fundamental principle involved with diamond anvil cell research. Undergraduate researchers from the lab participated in the presentations and hands-on experiments, and answered any

  15. Annular array and method of manufacturing same

    DOEpatents

    Day, Robert A.

    1989-01-01

    A method for manufacturing an annular acoustic transducer array from a plate of transducer material, which enables production of precision aligned arrays at low cost. The circular plate is sawed along at least two lines that are radial to the axis of the plate. At steps along each radial cut, the plate is rotated first in one direction and then in an opposite direction by a predetermined angle such as slightly less than 90.degree.. The cuts result in the forming of several largely ring-shaped lands, each largely ring-shaped land being joined to the other rings of different radii by thin portions of the plate, and each ring being cut into segments. The bridges that join different rings, hold the transducer together until it can be mounted on a lens.

  16. Electron diffusion in the annular Penning trap

    NASA Astrophysics Data System (ADS)

    Robertson, Scott; Quraishi, Qudsia; Walch, Bob

    2002-11-01

    Transport by cross-field diffusion has been studied in the annular Penning trap in which a nonneutral plasma of electrons is contained between concentric cylinders. At densities sufficiently low (<10^5 cm-3) to suppress mobility transport arising from the space charge electric field, the dominant sources of transport are diffusion from collisions of electrons with added helium gas and asymmetry transport from stray fields. The collisional diffusivity is shown to scale linearly with collision frequency and inversely with the square of the axial magnetic field. The measured mean energy is initially 0.3 eV and the least energetic electrons are lost more slowly as a consequence of the energy dependence of the diffusivity. Decay constants are about a factor of four higher than calculated from the electron-helium momentum transfer collision frequency. Both the asymmetry transport and the collisional transport are shown to depend upon the cleanliness of the trap surfaces.

  17. Electron diffusion in the annular Penning trap

    NASA Astrophysics Data System (ADS)

    Quraishi, Qudsia; Robertson, Scott; Walch, Bob

    2002-08-01

    Transport by cross-field diffusion has been studied in the annular Penning trap in which a nonneutral plasma of electrons is contained between concentric cylinders. At densities sufficiently low (<105 cm-3) to suppress mobility transport arising from the space charge electric field, the dominant sources of transport are diffusion from collisions of electrons with added helium gas and asymmetry transport from stray fields. The collisional diffusivity is shown to scale linearly with collision frequency and inversely with the square of the axial magnetic field. The measured mean energy is initially 0.3 eV and the least energetic electrons are lost more slowly as a consequence of the energy dependence of the diffusivity. Decay constants are about a factor of four higher than calculated from the electron-helium momentum transfer collision frequency. Both the asymmetry transport and the collisional transport are shown to depend upon the cleanliness of the trap surfaces.

  18. Preliminary fracture analysis of the core pressure boundary tube for the Advanced Neutron Source Research Reactor

    SciTech Connect

    Schulz, K.C.; Yahr, G.T.

    1995-08-01

    The outer core pressure boundary tube (CPBT) of the Advanced neutron Source (ANS) reactor being designed at Oak Ridge National Laboratory is currently specified as being composed of 6061-T6 aluminum. ASME Boiler and Pressure Vessel Code fracture analysis rules for nuclear components are based on the use of ferritic steels; the expressions, tables, charts and equations were all developed from tests and analyses conducted for ferritic steels. Because of the nature of the Code, design with thin aluminum requires analytical approaches that do not directly follow the Code. The intent of this report is to present a methodology comparable to the ASME Code for ensuring the prevention of nonductile fracture of the CPBT in the ANS reactor. 6061-T6 aluminum is known to be a relatively brittle material; the linear elastic fracture mechanics (LEFM) approach is utilized to determine allowable flaw sizes for the CPBT. A J-analysis following the procedure developed by the Electric Power Research Institute was conducted as a check; the results matched those for the LEFM analysis for the cases analyzed. Since 6061-T6 is known to embrittle when irradiated, the reduction in K{sub Q} due to irradiation is considered in the analysis. In anticipation of probable requirements regarding maximum allowable flaw size, a survey of nondestructive inspection capabilities is also presented. A discussion of probabilistic fracture mechanics approaches, principally Monte Carlo techniques, is included in this report as an introduction to what quantifying the probability of nonductile failure of the CPBT may entail.

  19. Disentangling the dynamic core: a research program for a neurodynamics at the large-scale.

    PubMed

    Le Van Quyen, Michel

    2003-01-01

    My purpose in this paper is to sketch a research direction based on Francisco Varela's pioneering work in neurodynamics (see also Rudrauf et al. 2003, in this issue). Very early on he argued that the internal coherence of every mental-cognitive state lies in the global self-organization of the brain activities at the large-scale, constituting a fundamental pole of integration called here a "dynamic core". Recent neuroimaging evidence appears to broadly support this hypothesis and suggests that a global brain dynamics emerges at the large scale level from the cooperative interactions among widely distributed neuronal populations. Despite a growing body of evidence supporting this view, our understanding of these large-scale brain processes remains hampered by the lack of a theoretical language for expressing these complex behaviors in dynamical terms. In this paper, I propose a rough cartography of a comprehensive approach that offers a conceptual and mathematical framework to analyze spatio-temporal large-scale brain phenomena. I emphasize how these nonlinear methods can be applied, what property might be inferred from neuronal signals, and where one might productively proceed for the future. This paper is dedicated, with respect and affection, to the memory of Francisco Varela.

  20. Annular MHD Physics for Turbojet Energy Bypass

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.

    2011-01-01

    The use of annular Hall type MHD generator/accelerator ducts for turbojet energy bypass is evaluated assuming weakly ionized flows obtained from pulsed nanosecond discharges. The equations for a 1-D, axisymmetric MHD generator/accelerator are derived and numerically integrated to determine the generator/accelerator performance characteristics. The concept offers a shockless means of interacting with high speed inlet flows and potentially offers variable inlet geometry performance without the complexity of moving parts simply by varying the generator loading parameter. The cycle analysis conducted iteratively with a spike inlet and turbojet flying at M = 7 at 30 km altitude is estimated to have a positive thrust per unit mass flow of 185 N-s/kg. The turbojet allowable combustor temperature is set at an aggressive 2200 deg K. The annular MHD Hall generator/accelerator is L = 3 m in length with a B(sub r) = 5 Tesla magnetic field and a conductivity of sigma = 5 mho/m for the generator and sigma= 1.0 mho/m for the accelerator. The calculated isentropic efficiency for the generator is eta(sub sg) = 84 percent at an enthalpy extraction ratio, eta(sub Ng) = 0.63. The calculated isentropic efficiency for the accelerator is eta(sub sa) = 81 percent at an enthalpy addition ratio, eta(sub Na) = 0.62. An assessment of the ionization fraction necessary to achieve a conductivity of sigma = 1.0 mho/m is n(sub e)/n = 1.90 X 10(exp -6), and for sigma = 5.0 mho/m is n(sub e)/n = 9.52 X 10(exp -6).

  1. Recurrent Annular Peripheral Choroidal Detachment after Trabeculectomy

    PubMed Central

    Liu, Shaohui; Sun, Lisa L.; Kavanaugh, A. Scott; Langford, Marlyn P.; Liang, Chanping

    2013-01-01

    We report a challenging case of recurrent flat anterior chamber without hypotony after trabeculectomy in a 54-year-old Black male with a remote history of steroid-treated polymyositis, cataract surgery, and uncontrolled open angle glaucoma. The patient presented with a flat chamber on postoperative day 11, but had a normal fundus exam and intraocular pressure (IOP). Flat chamber persisted despite treatment with cycloplegics, steroids, and a Healon injection into the anterior chamber. A transverse B-scan of the peripheral fundus revealed a shallow annular peripheral choroidal detachment. The suprachoroidal fluid was drained. The patient presented 3 days later with a recurrent flat chamber and an annular peripheral choroidal effusion. The fluid was removed and reinforcement of the scleral flap was performed with the resolution of the flat anterior chamber. A large corneal epithelial defect developed after the second drainage. The oral prednisone was tapered quickly and the topical steroid was decreased. One week later, his vision decreased to count fingers with severe corneal stromal edema and Descemet's membrane folds that improved to 20/50 within 24 h of resumption of the oral steroid and frequent topical steroid. The patient's visual acuity improved to 20/20 following a slow withdrawal of the oral and topical steroid. Eight months after surgery, the IOP was 15 mm Hg without glaucoma medication. The detection of a shallow anterior choroidal detachment by transverse B-scan is critical to making the correct diagnosis. Severe cornea edema can occur if the steroid is withdrawn too quickly. Thus, steroids should be tapered cautiously in steroid-dependent patients. PMID:24348402

  2. Disseminated granuloma annulare: study on eight cases.

    PubMed

    Pătraşcu, V; Giurcă, Claudia; Ciurea, Raluca Niculina; Georgescu, Claudia Valentina

    2013-01-01

    Granuloma annulare (GA) is classified as localized, generalized/disseminated, subcutaneous, and perforating types. The studies show connection with diabetes mellitus, lipidic metabolic disorders, malignant diseases, thyroid disorders, infections (HBV, HCV, HIV). We performed a retrospective study between 2010-2011, regarding disseminated GA (GAD), and the relationship between GAD and other comorbidities. We clinically and histologically diagnosed eight cases of GAD. The patients were also investigated for the diagnosis of associated diseases. The treatment included topical corticosteroids, antihistamines, Calcipotriol/Betamethasone, Tacrolimus 0.03%, Pentoxifylline, Hydroxychloroquine. Therapeutic response was assessed one month and three months after hospitalization. Our patients were five women and three men, aged 46-68 years, mean age 57.25 years, with a disease history of one year and a half (between three months and four years). The lesions occurred in the upper extremities (eight cases), distal extremities (three cases), cervical area (two cases), and trunk (five cases). In seven cases, we found annular appearance and one patient had disseminated small papules eruption. Associated pathology was diabetes mellitus type II (five cases), overweight and obesity (five cases), dyslipidemia (three cases), hypothyroidism (one case), rheumatoid arthritis (one case), external ear canal basal carcinoma (one case). Although there is controversy regarding the relationship between GAD and associated diseases, it is accepted that it is significantly associated with diabetes mellitus, also found in our study in five out of eight cases. We noticed obvious improvements after local and general treatment. It is confirmed that GAD is prevalent in women, over 40-year-old. GAD is often associated with diabetes and dyslipidemia, therefore it is necessary to investigate patients in this direction. The histopathological exam is essential for an accurate confirmation of GA. PMID

  3. A Study on the Conceptual Design of a 1,500 MWe Passive PWR with Annular Fuel

    SciTech Connect

    Kwi Lim Lee; Soon Heung Chang

    2004-07-01

    In this study, the preliminary conceptual design of a 1500 MWe pressurized water reactor (PWR) with annular fuel has been performed. This design is derived from the AP1000 which is a 1000 MWe PWR with two-loop. However, the present design is a 1500 MWe PWR with three-loop, passive safety features and extensive plant simplifications to enhance the construction, operation, and maintenance. The preliminary design parameters of this reactor have been determined through simple relation to those of AP1000 for reactor, reactor coolant system, and passive safety injection system. Using the MATRA code, we analyze the core designs for two alternatives on fuel assembly types: solid fuel and annular fuel. The performance of reactor cooling systems is evaluated through the accident of the cold leg break in the core makeup tank loop by using MARS2.1 code. This study presents the developmental strategy, preliminary design parameters and safety analysis results. (authors)

  4. [Core research areas on addiction in Spain through the Web of Science bibliographic coupling analysis (2000-2013)].

    PubMed

    G, González-Alcaide; A, Calafat; E, Becoña

    2014-01-01

    The present study identifies the main Spanish core research areas in the area of addictions through the bibliographic coupling analysis of the publications at the Web of Science under the substance abuse heading. The bibliographic coupling methodology is the analytical procedure that determines the thematic-intellectual proximity of the documents under consideration through the identification of the shared or simultaneously cited bibliography by those documents. A factor analysis and network analysis have been carried out to cluster documents, graphically represent the existing core research areas, and analyse the interrelations between them. We have identified 30 core research areas. Alcohol is the topic of attention of 17 areas and cocaine has a strong presence in 6. Heroin and opiates are only present as prominent substances in 4 areas and cannabis and tobacco in other two for each substance. It has been found that there is a significant degree of fragmentation in the area, with the existence of numerous research foci but with few connections with each other and few documents showing shared common knowledge. Also noteworthy is the large number of emerging research areas, reflecting an incipient stage in many of the research topics. Consideration must be placed in promoting scientific consensus and cohesion of the discipline as well as to encouraging the consolidation of main lines that respond to the social problems and research challenges.

  5. Core Intervention Components: Identifying and Operationalizing What Makes Programs Work. ASPE Research Brief

    ERIC Educational Resources Information Center

    Blase, Karen; Fixsen, Dean

    2013-01-01

    This brief is part of a series that explores key implementation considerations. It focuses on the importance of identifying, operationalizing, and implementing the "core components" of evidence-based and evidence-informed interventions that likely are critical to producing positive outcomes. The brief offers a definition of "core components",…

  6. E-research platform of EPOS Thematic Core Service "ANTHROPOGENIC HAZARDS"

    NASA Astrophysics Data System (ADS)

    Orlecka-Sikora, Beata; Lasocki, Stanisław; Grasso, Jean Robert; Schmittbuhl, Jean; Kwiatek, Grzegorz; Garcia, Alexander; Cassidy, Nigel; Sterzel, Mariusz; Szepieniec, Tomasz; Dineva, Savka; Biggare, Pascal; Saccorotti, Gilberto; Sileny, Jan; Fischer, Tomas

    2016-04-01

    EPOS Thematic Core Service ANTHROPOGENIC HAZARDS (TCS AH) aims to create new research opportunities in the field of anthropogenic hazards evoked by exploitation of georesources. TCS AH, based on the prototype built in the framework of the IS-EPOS project (https://tcs.ah-epos.eu/), financed from Polish structural funds (POIG.02.03.00-14-090/13-00), is being further developed within EPOS IP project (H2020-INFRADEV-1-2015-1, INFRADEV-3-2015). TCS AH is designed as a functional e-research environment to ensure a researcher the maximum possible freedom for in silico experimentation by providing a virtual laboratory in which researcher will be able to create own workspace with own processing streams. The unique integrated RI is: (i) data gathered in the so- called "episodes", comprehensively describing a geophysical process, induced or triggered by human technological activity, which under certain circumstances can become hazardous for people, infrastructure and the environment and (ii) problem-oriented, specific high-level services, with the particular attention devoted to methods analyzing correlations between technology, geophysical response and resulting hazard. Services to be implemented are grouped within six blocks: (1) Basic services for data integration and handling; (2) Services for physical models of stress/strain changes over time and space as driven by geo-resource production; (3) Services for analysing geophysical signals; (4) Services to extract the relation between technological operations and observed induced seismic/deformation; (5) Services to quantitative probabilistic assessments of anthropogenic seismic hazard - statistical properties of anthropogenic seismic series and their dependence on time-varying anthropogenesis; ground motion prediction equations; stationary and time-dependent probabilistic seismic hazard estimates, related to time-changeable technological factors inducing the seismic process; (6) Simulator for Multi

  7. The effect of inlet swirl on the dynamics of long annular seals in centrifugal pumps

    NASA Technical Reports Server (NTRS)

    Ismail, M.; Brown, R. D.; France, D.

    1994-01-01

    This paper describes additional results from a continuing research program which aims to identify the dynamics of long annular seals in centrifugal pumps. A seal test rig designed at Heriot-Watt University and commissioned at Weir Pumps Research Laboratory in Alloa permits the identification of mass, stiffness, and damping coefficients using a least-squares technique based on the singular value decomposition method. The analysis is carried out in the time domain using a multi-fiequency forcing function. The experimental method relies on the forced excitation of a flexibly supported stator by two hydraulic shakers. Running through the stator embodying two symmetrical balance drum seals is a rigid rotor supported in rolling element bearings. The only physical connection between shaft and stator is the pair of annular gaps filled with pressurized water discharged axially. The experimental coefficients obtained from the tests are compared with theoretical values.

  8. Substantiation of parameters of the geometric model of the research reactor core for the calculation using the Monte Carlo method

    SciTech Connect

    Radaev, A. I. Schurovskaya, M. V.

    2015-12-15

    The choice of the spatial nodalization for the calculation of the power density and burnup distribution in a research reactor core with fuel assemblies of the IRT-3M and VVR-KN type using the program based on the Monte Carlo code is described. The influence of the spatial nodalization on the results of calculating basic neutronic characteristics and calculation time is investigated.

  9. Scientific core hole VC-2A, Valles Caldera, New Mexico

    SciTech Connect

    Musgrave, J.; Goff, S. ); Turner, T. , Salt Lake City, UT )

    1990-10-01

    This report details the remedial action activities that were necessary to complete scientific core hole Valles caldera {number sign}2A (VC-2A) before it was relinquished to the landowners. Sandia National Laboratories, acting as the Geoscience Research Drilling Office (GRDO), managed the coring operations. Los Alamos National Laboratory (Los Alamos) obtained the proper drilling permits with the New Mexico State Engineers Office (SEO). A legal agreement between Los Alamos and the landowners states that the Laboratory will give the landowners the completed core hold with casing, well head, and other hardware at the end of May 1991, or earlier if scientific investigations were completed. By May 1988, the Science Team completed the planned scientific investigations in the VC-2A core hole. Upon the insistence of the GRDO, the New Mexico Oil Conservation Division (OCD) inspected the core hole, declared jurisdiction, and required that the 11.43- by 11.43-cm annular cement job be repaired to comply with OCD regulations. These regulations state that there must be a return to surface of cement in all cementing operations. We successfully completed a squeeze cementing operation and relinquished the core hold to the landowners in November 1988 to the satisfaction of the OCD, SEO, the landowners, and Los Alamos. 7 refs., 4 figs., 1 tab.

  10. Virtual cathode microwave generator having annular anode slit

    DOEpatents

    Kwan, Thomas J. T.; Snell, Charles M.

    1988-01-01

    A microwave generator is provided for generating microwaves substantially from virtual cathode oscillation. Electrons are emitted from a cathode and accelerated to an anode which is spaced apart from the cathode. The anode has an annular slit therethrough effective to form the virtual cathode. The anode is at least one range thickness relative to electrons reflecting from the virtual cathode. A magnet is provided to produce an optimum magnetic field having the field strength effective to form an annular beam from the emitted electrons in substantial alignment with the annular anode slit. The magnetic field, however, does permit the reflected electrons to axially diverge from the annular beam. The reflected electrons are absorbed by the anode in returning to the real cathode, such that substantially no reflexing electrons occur. The resulting microwaves are produced with a single dominant mode and are substantially monochromatic relative to conventional virtual cathode microwave generators.

  11. Principle of radial transport in low temperature annular plasmas

    SciTech Connect

    Zhang, Yunchao Charles, Christine; Boswell, Rod

    2015-07-15

    Radial transport in low temperature annular plasmas is investigated theoretically in this paper. The electrons are assumed to be in quasi-equilibrium due to their high temperature and light inertial mass. The ions are not in equilibrium and their transport is analyzed in three different situations: a low electric field (LEF) model, an intermediate electric field (IEF) model, and a high electric field (HEF) model. The universal IEF model smoothly connects the LEF and HEF models at their respective electric field strength limits and gives more accurate results of the ion mobility coefficient and effective ion temperature over the entire electric field strength range. Annular modelling is applied to an argon plasma and numerical results of the density peak position, the annular boundary loss coefficient and the electron temperature are given as functions of the annular geometry ratio and Paschen number.

  12. Axicon-based annular laser trap for studies on sperm activity

    NASA Astrophysics Data System (ADS)

    Shao, Bing; Vinson, Jaclyn M.; Botvinick, Elliot L.; Esener, Sadik C.; Berns, Michael W.

    2005-08-01

    As a powerful and noninvasive tool, laser trapping has been widely applied for the confinement and physiological study of biological cells and organelles. Researchers have used the single spot laser trap to hold individual sperm and quantitatively evaluated the motile force generated by a sperm. Early studies revealed the relationship between sperm motility and swimming behavior and helped the investigations in medical aspects of sperm activity. As sperm chemotaxis draws more and more interest in fertilization research, the studies on sperm-egg communication may help to explain male or female infertility and provide exciting new approaches to contraception. However, single spot laser trapping can only be used to investigate an individual target, which has limits in efficiency and throughput. To study the chemotactic response of sperm to eggs and to characterize sperm motility, an annular laser trap with a diameter of several hundred microns is designed, simulated with ray tracing tool, and implemented. An axicon transforms the wavefront such that the laser beam is incident on the microscope objective from all directions while filling the back aperture completely for high efficiency trapping. A trapping experiment with microspheres is carried out to evaluate the system performance. The power requirement for annular sperm trapping is determined experimentally and compared with theoretical calculations. With a chemo-attractant located in the center and sperm approaching from all directions, the annular laser trapping could serve as a speed bump for sperm so that motility characterization and fertility sorting can be performed efficiently.

  13. Experimental Results for an Annular Aerospike with Differential Throttling

    NASA Technical Reports Server (NTRS)

    Ruf, Joseph H.; McDaniels, David M.

    2005-01-01

    A) MSFC funded an internal study on Altitude Compensating Nozzles: 1) Develop an ACN design and performance prediction tool. 2) Design, build and test cold flow ACN nozzles. 3) An annular aerospike nozzle was designed and tested. 4) Incorporated differential throttling to assess Thrust Vector Control. B) Objective of the test hardware: 1) Provide design tool verification. 2) Provide benchmark data for CFD calculations. 3) Experimentally measure side force, or TVC, for a differentially throttled annular aerospike.

  14. The Experimental Thermal Behavior of AN Annular Structure

    NASA Astrophysics Data System (ADS)

    Hwang, Jeong-Ki; Suh, Chang-Min; Kim, Chae-Ho

    A half-scaled large structural model for an annular structure was built, and its behaviors were tested and obtained by thermal cyclic loads. The model design and test conditions were determined to take into consideration the thermal and mechanical loads acting on the annular structure by numerical methods. Temperature profiles and strains of the flexure were measured during the test. After completion of the thermal cyclic tests, no evidence of crack initiation and propagation were identified by a dye penetration test.

  15. Elastic-plastic analysis of annular plate problems using NASTRAN

    NASA Technical Reports Server (NTRS)

    Chen, P. C. T.

    1983-01-01

    The plate elements of the NASTRAN code are used to analyze two annular plate problems loaded beyond the elastic limit. The first problem is an elastic-plastic annular plate loaded externally by two concentrated forces. The second problem is stressed radially by uniform internal pressure for which an exact analytical solution is available. A comparison of the two approaches together with an assessment of the NASTRAN code is given.

  16. New mitral annular force transducer optimized to distinguish annular segments and multi-plane forces.

    PubMed

    Skov, Søren Nielsen; Røpcke, Diana Mathilde; Ilkjær, Christine; Rasmussen, Jonas; Tjørnild, Marcell Juan; Jimenez, Jorge H; Yoganathan, Ajit P; Nygaard, Hans; Nielsen, Sten Lyager; Jensen, Morten Olgaard

    2016-03-21

    Limited knowledge exists about the forces acting on mitral valve annuloplasty repair devices. The aim of this study was to develop a new mitral annular force transducer to measure the forces acting on clinically used mitral valve annuloplasty devices. The design of an X-shaped transducer in the present study was optimized for simultaneous in- and out-of-plane force measurements. Each arm was mounted with strain gauges on four circumferential elements to measure out-of-plane forces, and the central parts of the X-arms were mounted with two strain gauges to measure in-plane forces. A dedicated calibration setup was developed to calibrate isolated forces with tension and compression for in- and out-of-plane measurements. With this setup, it was possible with linear equations to isolate and distinguish measured forces between the two planes and minimize transducer arm crosstalk. An in-vitro test was performed to verify the crosstalk elimination method and the assumptions behind it. The force transducer was implanted and evaluated in an 80kg porcine in-vivo model. Following crosstalk elimination, in-plane systolic force accumulation was found to be in average 4.0±0.1N and the out-of-plane annular segments experienced an average force of 1.4±0.4N. Directions of the systolic out-of-plane forces indicated movements towards a saddle shaped annulus, and the transducer was able to measure independent directional forces in individual annular segments. Further measurements with the new transducer coupled with clinical annuloplasty rings will provide a detailed insight into the biomechanical dynamics of these devices.

  17. Research on vibration measurement of a cantilever beam by twin-core fiber

    NASA Astrophysics Data System (ADS)

    Geng, Tao; Liu, Tao; Peng, Feng; Dai, Qiang; Yang, Yuan

    2009-05-01

    A novel interference transducer based on the measurement principle of multicore fiber interference for vibration measurement of a cantilever beam is designed in the paper. Twin-core fiber is special designed fiber, which contains a pair of parallel fiber core. Two paths integrated in one fiber not only greatly decreases sensor's volume, but also makes environment temperature effect approximately equal to each. A twin-core fiber which is pasted on the cantilever beam with epoxy resin is used as the sensing element. The twin-core fiber act as a two-beam in-fiber integrated interferometer that has a far-field interferometric fringe pattern which shift thereupon with the cantilever beam oscillates. CCD was used to measure the displacement of interferometer fringes instead of the traditional photodetector. The continuous capture of interference fringes was realized. The design of low pass filter and image smoothing were finished according to the characteristics of interference fringes. Orientation error of interference fringe center was removed. Displacement of fringe center was calculated and the spectrum of the displacement was analyzed with Fourier Transform. The system uses high-speed CCD camera as the photoelectric transformer. By using the high sensitivity twin-core fiber, the system realizes high precision measurement of vibration frequency, and ensures real-time performance. The experiment results show that the vibration measurement method is feasible and possesses potential application prospect in tiny vibration measure.

  18. Solar cycle modulation of Southern Annular Mode

    NASA Astrophysics Data System (ADS)

    Kuroda, Yuhji

    2016-04-01

    Climate is known to be affected by various factors, including oceanic changes and volcanic eruptions. 11-year solar cycle change is one of such important factors. Observational analysis shows that the winter-mean North Atlantic Oscillation (NAO) and late-winter/spring Southern Annular Mode (SAM) show structural modulation associated with 11-year solar cycle. In fact, these signals tend to extend from surface to upper stratosphere and persistent longer period only in the High Solar (HS) years. In the present study, we used 35-year record of ERA-Interim reanalysis data and performed wave-energy and momentum analysis on the solar-cycle modulation of the SAM to examine key factors to create such solar-SAM relationship. It is found that enhanced wave-mean flow interaction tends to take place in the middle stratosphere in association with enhanced energy input from diabatic heating on September only in HS years. The result suggests atmospheric and solar conditions on September are keys to create solar-SAM relationship.

  19. Fluxon Dynamics in Elliptic Annular Josephson Junctions

    NASA Astrophysics Data System (ADS)

    Monaco, Roberto; Mygind, Jesper

    2016-04-01

    We analyze the dynamics of a magnetic flux quantum (current vortex) trapped in a current-biased long planar elliptic annular Josephson tunnel junction. The system is modeled by a perturbed sine-Gordon equation that determines the spatial and temporal behavior of the phase difference across the tunnel barrier separating the two superconducting electrodes. In the absence of an external magnetic field, the fluxon dynamics in an elliptic annulus does not differ from that of a circular annulus where the stationary fluxon speed merely is determined by the system losses. The interaction between the vortex magnetic moment and a spatially homogeneous in-plane magnetic field gives rise to a tunable periodic non-sinusoidal potential which is strongly dependent on the annulus aspect ratio. We study the escape of the vortex from a well in the tilted potential when the bias current exceeds the depinning current. The smallest depinning current as well as the lowest sensitivity of the annulus to the external field is achieved when the axes ratio is equal to √{2}. The presented extensive numerical results are in good agreement with the findings of the perturbative approach. We also probe the rectifying properties of an asymmetric potential implemented with an egg-shaped annulus formed by two semi-elliptic arcs.

  20. Correlation and spectral measurements of fluctuating pressures and velocities in annular turbulent flow. [PWR; BWR

    SciTech Connect

    Wilson, R.J.; Jones, B.G.; Roy, R.P.

    1980-02-01

    An experimental study of the fluctuating velocity field, the fluctuating static wall pressure and the in-stream fluctuating static pressure in an annular turbulent air flow system with a radius ratio of 4.314 has been conducted. The study included direct measurements of the mean velocity profile, turbulent velocity field; fluctuating static wall pressure and in-stream fluctuating static pressure from which the statistical values of the turbulent intensity levels, power spectral densities of the turbulent quantities, the cross-correlation between the fluctuating static wall pressure and the fluctuating static pressure in the core region of the flow and the cross-correlation between the fluctuating static wall pressure and the fluctuating velocity field in the core region of the flow were obtained.

  1. X-ray diffraction from bone employing annular and semi-annular beams.

    PubMed

    Dicken, A J; Evans, J P O; Rogers, K D; Stone, N; Greenwood, C; Godber, S X; Prokopiou, D; Clement, J G; Lyburn, I D; Martin, R M; Zioupos, P

    2015-08-01

    There is a compelling need for accurate, low cost diagnostics to identify osteo-tissues that are associated with a high risk of fracture within an individual. To satisfy this requirement the quantification of bone characteristics such as 'bone quality' need to exceed that provided currently by densitometry. Bone mineral chemistry and microstructure can be determined from coherent x-ray scatter signatures of bone specimens. Therefore, if these signatures can be measured, in vivo, to an appropriate accuracy it should be possible by extending terms within a fracture risk model to improve fracture risk prediction.In this preliminary study we present an examination of a new x-ray diffraction technique that employs hollow annular and semi-annular beams to measure aspects of 'bone quality'. We present diffractograms obtained with our approach from ex vivo bone specimens at Mo Kα and W Kα energies. Primary data is parameterized to provide estimates of bone characteristics and to indicate the precision with which these can be determined.

  2. Research Commentary: Educational Technology--An Equity Challenge to the Common Core

    ERIC Educational Resources Information Center

    Kitchen, Richard; Berk, Sarabeth

    2016-01-01

    The implementation of the Common Core State Standards for Mathematics (National Governors Association Center for Best Practices & Council of Chief State School Officers, 2010) has the potential to move forward key features of standards-based reforms in mathematics that have been promoted in the United States for more than 2 decades (e.g.,…

  3. Implementation of the Common Core State Standards. A Policy Research Brief

    ERIC Educational Resources Information Center

    National Council of Teachers of English, 2013

    2013-01-01

    The Common Core State Standards (CCSS) for English Language Arts (ELA), designed to make students college and career ready, were released in June 2010, and have since been adopted by 45 states seeking to be eligible for Race to the Top funds offered by the US Department of Education. The states that signed on with the CCSS agreed to fully…

  4. Lessons from Sociocultural Writing Research for Implementing the Common Core State Standards

    ERIC Educational Resources Information Center

    Woodard, Rebecca; Kline, Sonia

    2016-01-01

    The Common Core State Standards advocate more writing than previous standards; however, in taking a college and career readiness perspective, the Standards neglect to emphasize the role of context and culture in learning to write. We argue that sociocultural perspectives that pay attention to these factors offer insights into how to interpret and…

  5. Potential Psychosocial and Instructional Consequences of the Common Core State Standards: Implications for Research and Practice

    ERIC Educational Resources Information Center

    Saeki, Elina; Pendergast, Laura; Segool, Natasha K.; von der Embse, Nathaniel P.

    2015-01-01

    Despite the recent rollout of the Common Core State Standards (CCSS), CCSS-aligned assessments, and test-based teacher evaluation systems, questions remain regarding the impact that these accountability policies will have on teachers and students. This article discusses the psychosocial and instructional consequences of test-based accountability…

  6. The Visual Core of Science: Definition and Applications to Education. Research Report

    ERIC Educational Resources Information Center

    Mathewson, James H.

    2005-01-01

    The phenomena and procedures of science and technology are visual, analogical and thematic. Based on these characteristics, the visual core of science can be described in terms of 'master images' in the content of science, and 'visual processes' in the practice of science. The resulting synoptic lists provide a basis for designing instructional…

  7. Core Journal Networks and Cocitation Maps: New Bibliometric Tools for Serials Research and Management.

    ERIC Educational Resources Information Center

    McCain, Katherine W.

    1991-01-01

    Describes the use of core journal network analysis and cocited journal mapping for studying the intellectual structure of scholarly fields and for evaluating journal collections to identify the most important titles in a discipline. Journals in the field of genetics are examined, and the use of spreadsheet software is explained. (31 references)…

  8. Research-Based Options for Education Policymaking: Common Core State Standards

    ERIC Educational Resources Information Center

    Mathis, William

    2012-01-01

    The Common Core State Standards (CCSS) have ardent supporters and strong critics. The actual effect of the CCSS, however, will depend much less on the standards themselves than on how they are used. Two factors are particularly crucial. The first is whether states invest in the necessary curricular and instructional resources and supports, and the…

  9. Transitions, Risks, and Actions in Coronary Events – Center for Outcomes Research and Education (TRACE-CORE): Design and Rationale

    PubMed Central

    Waring, Molly E.; McManus, Richard H.; Saczynski, Jane S.; Anatchkova, Milena D.; McManus, David D.; Devereaux, Randolph S.; Goldberg, Robert J.; Allison, Jeroan J.; Kiefe, Catarina I.

    2012-01-01

    Background Cardiovascular disease continues to cause significant morbidity, mortality, and impaired quality of life, with unrealized health gains from the underuse of available evidence. The Transitions, Risks, and Actions in Coronary Events Center for Outcomes Research and Education (TRACE-CORE) aims to advance the science of acute coronary syndromes (ACS) by examining the determinants and outcomes of the quality of the transition from the hospital to the community and by quantifying the impact of potentially-modifiable characteristics associated with decreased quality of life, rehospitalization, and mortality. Methods and Results TRACE-CORE is composed of a longitudinal multi-racial cohort of patients hospitalized with ACS, two research projects, and development of a nucleus of early stage investigators. We are currently enrolling 2,500 adults hospitalized for ACS at 6 hospitals in the northeastern and southeastern United States. We will follow these patients for 24 months after hospitalization through medical record abstraction and six patient interviews focusing on quality of life, cardiac events, rehospitalizations, mortality, and medical, behavioral, and psychosocial characteristics. The Transitions Project studies determinants of and disparities in outcomes of the quality of patients’ transition from the hospital to the community. Focusing on potentially modifiable factors, the Action Scores Project will develop and validate action scores to predict recurrent cardiac events, death, and quality of life, describe longitudinal variation in these scores, and develop a dashboard for patient and provider action based on these scores. Conclusions In TRACE-CORE, sound methodologic principles of observational studies converge with outcomes and effectiveness research approaches. We expect that our data, research infrastructure, and research projects will inform the development of novel secondary prevention approaches and underpin the careers of CVD outcomes

  10. Progress in analytical methods to predict and control azimuthal combustion instability modes in annular chambers

    NASA Astrophysics Data System (ADS)

    Bauerheim, M.; Nicoud, F.; Poinsot, T.

    2016-02-01

    Longitudinal low-frequency thermoacoustic unstable modes in combustion chambers have been intensively studied experimentally, numerically, and theoretically, leading to significant progress in both understanding and controlling these acoustic modes. However, modern annular gas turbines may also exhibit azimuthal modes, which are much less studied and feature specific mode structures and dynamic behaviors, leading to more complex situations. Moreover, dealing with 10-20 burners mounted in the same chamber limits the use of high fidelity simulations or annular experiments to investigate these modes because of their complexity and costs. Consequently, for such circumferential acoustic modes, theoretical tools have been developed to uncover underlying phenomena controlling their stability, nature, and dynamics. This review presents recent progress in this field. First, Galerkin and network models are described with their pros and cons in both the temporal and frequency framework. Then, key features of such acoustic modes are unveiled, focusing on their specificities such as symmetry breaking, non-linear modal coupling, forcing by turbulence. Finally, recent works on uncertainty quantifications, guided by theoretical studies and applied to annular combustors, are presented. The objective is to provide a global view of theoretical research on azimuthal modes to highlight their complexities and potential.

  11. Maximizing Multi-core Performance of the Weather Research and Forecast Model over the Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Roe, K.; Stevens, D.

    2010-09-01

    The Hawaiian Islands consist of dramatic terrain changes over short distances, resulting in a variety of microclimates in close proximity. To handle these challenging conditions, weather models must be run at very fine vertical and horizontal resolutions to produce accurate forecasts. Computational demands require WRF to be executed in parallel on the Maui High Performance Computing Center’s Mana system, a PowerEdge M610 Linux cluster. This machine has 1,152 compute nodes, each with two 2.8 GHz quad-core Intel® Nehalem processors and 24 GB RAM. Realizing maximum performance on Mana relied on the determination of an optimal number of cores to use per socket, the efficiency of an MPI only implementation, an optimal set of parameters for adaptive time stepping, a way to meet the strict stability requirements necessary for Hawaii, effective choices for processor and memory affinity, and parallel automation techniques for producing forecast imagery.

  12. Research of real-time wavefront reconstruction and control based on multi-core DSP

    NASA Astrophysics Data System (ADS)

    Wang, Zhui; Zhou, Luchun; Li, Mei; Zhang, Haotian

    2014-09-01

    In an Adaptive Optics system, the Real Time Processor is as important as the human brain. Processing latency is a key index of Real Time Proceesors . In this paper, we propose a new processing method that significantly reduce the processing latency, which combined the design idea of multi-core parallel processing on space and time. In addition, by comparing the operating speed of CPU and the I/O speed of memory, we propose a reasonable memory allocation scheme. The experimental results show that the processing latency is 59.7us per frame using multi-core DSP TMS320C6678 as processing platform. The experiment is conducted on a system with 968 sub-apertures and 913 actuators.

  13. Non-axisymmetric annular curtain stability

    NASA Astrophysics Data System (ADS)

    Ahmed, Zahir U.; Khayat, Roger E.; Maissa, Philippe; Mathis, Christian

    2013-08-01

    A stability analysis of non-axisymmetric annular curtain is carried out for an axially moving viscous jet subject in surrounding viscous gas media. The effect of inertia, surface tension, gas-to-liquid density ratio, inner-to-outer radius ratio, and gas-to-liquid viscosity ratio on the stability of the jet is studied. In general, the axisymmetric disturbance is found to be the dominant mode. However, for small wavenumber, the non-axisymmetric mode is the most unstable mode and the one likely observed in reality. Inertia and the viscosity ratio for non-axisymmetric disturbances show a similar stability influence as observed for axisymmetric disturbances. The maximum growth rate in non-axisymmetric flow, interestingly, appears at very small wavenumber for all inertia levels. The dominant wavenumber increases (decreases) with inertia for non-axisymmetric (axisymmetric) flow. Gas-to-liquid density ratio, curvature effect, and surface tension, however, exhibit an opposite influence on growth rate compared to axisymmetric disturbances. Surface tension tends to stabilize the flow with reductions of the unstable wavenumber range and the maximum growth rate as well as the dominant wavenumber. The dominant wavenumber remains independent of viscosity ratio indicating the viscosity ratio increases the breakup length of the sheet with very little influence on the size of the drops. The range of unstable wavenumbers is affected only by curvature in axisymmetric flow, whereas all the stability parameters control the range of unstable wavenumbers in non-axisymmetric flow. Inertia and gas density increase the unstable wavenumber range, whereas the radius ratio, surface tension, and the viscosity ratio decrease the unstable wavenumber range. Neutral curves are plotted to separate the stable and unstable domains. Critical radius ratio decreases linearly and nonlinearly with the wavenumber for axisymmetric and non-axisymmetric disturbances, respectively. At smaller Weber numbers, a

  14. Higher Standards for All: Implications of the Common Core for Equity in Education. Research Brief

    ERIC Educational Resources Information Center

    Quay, Lisa

    2010-01-01

    The Civil Rights Research Roundtable on Education is an initiative of the Warren Institute that convenes an ongoing learning community composed of leading national civil rights organizations to discuss the latest educational research and evidence-based practices related to civil rights goals in education. This research brief reviews the research…

  15. Granuloma Annulare Mimicking Sarcoidosis: Report of Patient With Localized Granuloma Annulare Whose Skin Lesions Show 3 Clinical Morphologies and 2 Histology Patterns.

    PubMed

    Cohen, Philip R; Carlos, Casey A

    2015-07-01

    Granuloma annulare, a benign dermatosis of undetermined etiology, typically presents in a localized or generalized form. It has 3 distinctive histologic patterns: an infiltrative (interstitial) pattern, a palisading granuloma pattern, and an epithelioid nodule (sarcoidal granuloma) pattern. A man whose granuloma annulare skin lesions mimicked sarcoidosis is described. His localized granuloma annulare presented with a total of 3 lesions that each had a distinctive clinical morphology: an annular lesion of individual papules, a dermal nodule, and a linear arrangement of 3 papules. Two of his lesions showed a palisading granuloma histology pattern of granuloma annulare; however, the linear papules on his posterior neck lesion demonstrated noncaseating granulomas consistent with either the epithelioid nodule histology pattern of granuloma annulare or sarcoidal granuloma compatible with sarcoidosis. A comprehensive evaluation excluded the diagnosis of systemic sarcoidosis. Using the PubMed database, an extensive literature search was performed on granuloma annulare, epithelioid nodule, sarcoidal granuloma, and sarcoidosis. The histology patterns of granuloma annulare-emphasizing the history and differentiating features of the epithelioid nodule pattern from cutaneous sarcoidosis-were reviewed. The epithelioid nodule (sarcoidal granuloma) histology pattern of granuloma annulare is uncommon and may mimic the histology changes observed in sarcoidosis skin lesions; the absence of asteroid or other giant cell inclusions and an increase in mucin deposition between the collagen bundles favor the diagnosis of granuloma annulare. In addition, the epithelioid nodule pattern of granuloma annulare can rarely also show other histologic patterns of granuloma annulare in the same biopsy specimen or concurrently present with other clinical lesions of granuloma annulare that demonstrate a palisading granuloma, or possibly an infiltrative, histology pattern. However, the presence of an

  16. Granuloma Annulare Mimicking Sarcoidosis: Report of Patient With Localized Granuloma Annulare Whose Skin Lesions Show 3 Clinical Morphologies and 2 Histology Patterns.

    PubMed

    Cohen, Philip R; Carlos, Casey A

    2015-07-01

    Granuloma annulare, a benign dermatosis of undetermined etiology, typically presents in a localized or generalized form. It has 3 distinctive histologic patterns: an infiltrative (interstitial) pattern, a palisading granuloma pattern, and an epithelioid nodule (sarcoidal granuloma) pattern. A man whose granuloma annulare skin lesions mimicked sarcoidosis is described. His localized granuloma annulare presented with a total of 3 lesions that each had a distinctive clinical morphology: an annular lesion of individual papules, a dermal nodule, and a linear arrangement of 3 papules. Two of his lesions showed a palisading granuloma histology pattern of granuloma annulare; however, the linear papules on his posterior neck lesion demonstrated noncaseating granulomas consistent with either the epithelioid nodule histology pattern of granuloma annulare or sarcoidal granuloma compatible with sarcoidosis. A comprehensive evaluation excluded the diagnosis of systemic sarcoidosis. Using the PubMed database, an extensive literature search was performed on granuloma annulare, epithelioid nodule, sarcoidal granuloma, and sarcoidosis. The histology patterns of granuloma annulare-emphasizing the history and differentiating features of the epithelioid nodule pattern from cutaneous sarcoidosis-were reviewed. The epithelioid nodule (sarcoidal granuloma) histology pattern of granuloma annulare is uncommon and may mimic the histology changes observed in sarcoidosis skin lesions; the absence of asteroid or other giant cell inclusions and an increase in mucin deposition between the collagen bundles favor the diagnosis of granuloma annulare. In addition, the epithelioid nodule pattern of granuloma annulare can rarely also show other histologic patterns of granuloma annulare in the same biopsy specimen or concurrently present with other clinical lesions of granuloma annulare that demonstrate a palisading granuloma, or possibly an infiltrative, histology pattern. However, the presence of an

  17. Annular lupus vulgaris: an unusual case undiagnosed for five years.

    PubMed

    Gönül, Müzeyyen; Kiliç, Arzu; Külcü Cakmak, Seray; Gül, Ulker; Koçak, Oğuzhan; Demiriz, Murat

    2007-01-01

    Tuberculosis is still a serious problem in both developing and developed countries. It is often confused with various cutaneous disorders both clinically and histopathologically.A 46-year-old woman attended our clinic with progressive, asymptomatic, annular skin lesions on her right upper extremity for 5 years. She had received many different therapies for these lesions at other institutions previously but these medications were not effective and the lesions deteriorated. On dermatological examination, well-demarcated, irregular bordered, violaceous colored, elevated and crusted annular lesions on her right hand dorsum and forearm were observed. She was diagnosed as having lupus vulgaris clinically and histopathologically. Antituberculosis therapy was administered and regression of the lesions started in the second week of medication.We report a case of long-standing, undiagnosed and uncommon, annular form of lupus vulgaris. We want to stress that clinical and histopathological findings are still important for the diagnosis of cutaneous tuberculosis.

  18. Imaging performance of annular apertures. II - Line spread functions

    NASA Technical Reports Server (NTRS)

    Tschunko, H. F. A.

    1978-01-01

    Line images formed by aberration-free optical systems with annular apertures are investigated in the whole range of central obstruction ratios. Annular apertures form lines images with central and side line groups. The number of lines in each line group is given by the ratio of the outer diameter of the annular aperture divided by the width of the annulus. The theoretical energy fraction of 0.889 in the central line of the image formed by an unobstructed aperture increases for centrally obstructed apertures to 0.932 for the central line group. Energy fractions for the central and side line groups are practically constant for all obstruction ratios and for each line group. The illumination of rectangular secondary apertures of various length/width ratios by apertures of various obstruction ratios is discussed.

  19. High-Power, Annular-Beam Klystron Amplifiers

    NASA Astrophysics Data System (ADS)

    Pasour, John; Smithe, David; Ludeking, Larry; Friedman, Moshe

    2002-08-01

    Annular beam klystron amplifiers are being developed at L-band and at X-band. These devices are designed to operate at power levels of hundreds of MW to approx1 GW, with pulse durations up to 800 nsec. The L-band amplifier uses an 11-cm-diameter, 3-mm-thick annular beam (450 kV, 4.5 kA) inside an open beam tube with large-gap cavities. The X-band amplifier employs a 12-cm-diameter annular beam that propagates between inner and outer grounded cylinders and cavity structures. At higher frequencies or power levels, this so-called triaxial configuration provides a significant advantage over the open-cylinder configuration. In effect, it is a sheet-beam klystron bent into a full circle, thereby avoiding the edge effects. Alternatively, it can be thought of as the continuum limit of the multi-beam klystron.

  20. The Annular Gap: Gamma-Ray & Radio Emission of Pulsars

    NASA Astrophysics Data System (ADS)

    Qiao, G. J.; Du, Y. J.; Han, J. L.; Xu, R. X.

    2013-01-01

    Pulsars have been found more than 40 years. Observations from radio to gamma-rays present abundant information. However, the radiation mechanism is still an open question. It is found that the annular gap could be formed in the magnetosphere of pulsars (neutron stars or quark stars), which combines the advantages of the polar cap, slot gap and outer gap models. It is emphasized that observations of some radio pulsars, normal and millisecond gamma-ray pulsars (MSGPs) show that the annular gap would play a very important role. Here we show some observational and theoretical evidences about the annular gap. For example, bi-drifting sub-pulses; radio and gamma-ray millisecond pulsars and so on.

  1. On the Uncertainty of the Annular Mode Time Scale

    NASA Astrophysics Data System (ADS)

    Kim, Junsu; Reichler, Thomas

    2015-04-01

    The proper simulation of the annular mode (AM) time scale may be regarded as an important benchmark for climate models. Previous research demonstrated that climate models systematically overestimate this time scale. As suggested by the fluctuation-dissipation theorem, this may imply that models are overly sensitive to external forcings. Previous research also made it clear that calculating the AM time scale is a slowly converging process, necessitating relatively long time series and casting doubts on the usefulness of the historical reanalysis record to constrain climate models in terms of the AM time scale. Here, we use a 4000-year-long control simulation with the GFDL climate model CM2.1 to study the effects of internal atmospheric variability on the stability of the AM time scale. In particular, we ask whether a model's AM time scale and climate sensitivity can be constrained from the 50-year-long reanalysis record. We find that internal variability attaches large uncertainty to the AM time scale when diagnosed from decadal records. Even under fixed forcing conditions, at least 100 years of data are required in order to keep the uncertainty in the AM time scale of the Northern Hemisphere to 10%; over the Southern Hemisphere the required length increases to 200 years. If nature's AM time scale is similarly variable, there is no guarantee that the historical reanalysis record is a fully representative target for model evaluation. We further use the model simulation to investigate the dynamical coupling between the stratosphere and the troposphere from the perspective of the AM time scale. Over the Northern Hemisphere we find only weak indication for influences from stratosphere-troposphere coupling on the AM time scale. The situation is very different over the Southern Hemisphere, where we find robust connections between the AM time scale in the stratosphere and that in the troposphere, confirming and extending earlier results of influences of stratospheric

  2. Safety research on iodine plateout during postulated HTGR core heatup events

    SciTech Connect

    Barsell, A.W.; Chawla, O.P.; Hoot, C.G.

    1980-11-01

    In support of probabilistic risk assessment (PRA) studies on the high-temperature gas-cooled reactor (HTGR), an experimental program was conducted for iodine plateout on HTGR primary circuit metals during core heatup conditions. Metal iodine formation and adsorption characteristics were measured primarily for mild steel and to a limited extent for Incoloy 800 and other alloys. Pseudoisopiestic tests indicated quantitative formation of less volatile and water soluble iodides, FeI/sub 2/ or CrI/sub 2/, during core heatup conditions. The rate of formation of FeI/sub 2/ was limited by mass transfer at temperatures above 570/sup 0/K and was proportional to the partial pressure of iodine. The rate of iodide formation on chrome-nickel alloys appeared to be temperature sensitive, indicating slower reaction kinetics. The iodides preferentially plated out on surfaces at 520 to 620/sup 0/K. Plateout tests were also performed for FeI/sub 2/ in helium carrier gas flowing over mild steel or quartz surfaces over which a temperature gradient was maintained. PADLOC computer program correlations of the plateout profile based on the FeI/sub 2/ vapor pressure assumed in the PRA studies were in fair agreement. The temperature at which most of the plateout occurred was from 620 to 700/sup 0/K, depending on the partial pressure of the FeI/sub 2/ tested.

  3. Core-Cutoff Tool

    NASA Technical Reports Server (NTRS)

    Gheen, Darrell

    2007-01-01

    A tool makes a cut perpendicular to the cylindrical axis of a core hole at a predetermined depth to free the core at that depth. The tool does not damage the surrounding material from which the core was cut, and it operates within the core-hole kerf. Coring usually begins with use of a hole saw or a hollow cylindrical abrasive cutting tool to make an annular hole that leaves the core (sometimes called the plug ) in place. In this approach to coring as practiced heretofore, the core is removed forcibly in a manner chosen to shear the core, preferably at or near the greatest depth of the core hole. Unfortunately, such forcible removal often damages both the core and the surrounding material (see Figure 1). In an alternative prior approach, especially applicable to toxic or fragile material, a core is formed and freed by means of milling operations that generate much material waste. In contrast, the present tool eliminates the damage associated with the hole-saw approach and reduces the extent of milling operations (and, hence, reduces the waste) associated with the milling approach. The present tool (see Figure 2) includes an inner sleeve and an outer sleeve and resembles the hollow cylindrical tool used to cut the core hole. The sleeves are thin enough that this tool fits within the kerf of the core hole. The inner sleeve is attached to a shaft that, in turn, can be attached to a drill motor or handle for turning the tool. This tool also includes a cutting wire attached to the distal ends of both sleeves. The cutting wire is long enough that with sufficient relative rotation of the inner and outer sleeves, the wire can cut all the way to the center of the core. The tool is inserted in the kerf until its distal end is seated at the full depth. The inner sleeve is then turned. During turning, frictional drag on the outer core pulls the cutting wire into contact with the core. The cutting force of the wire against the core increases with the tension in the wire and

  4. Axisymmetric capillary waves on thin annular liquid sheets. II. Spatial development

    NASA Astrophysics Data System (ADS)

    Mehring, C.; Sirignano, W. A.

    2000-06-01

    The forced motion of semi-infinite axisymmetric thin inviscid annular liquid sheets, exiting from a nozzle or atomizer into a surrounding void under zero gravity but with constant gas-core pressure is analyzed by means of the reduced-dimension approach described in C. Mehring and W. A. Sirignano [Phys. Fluids 12, 1417 (2000)]. Linear analytical time-dependent ("limit-cycle") solutions to the pure boundary-value problem are presented as well as linear and nonlinear numerical (transient) solutions to the mixed boundary- and initial-value problem of initially undisturbed sheets harmonically forced at the orifice or nozzle exit. Group velocities for the six independent solutions to the linear boundary-value problem are used to determine the location of boundary conditions. Numerical simulations of the linear transient problem are employed to validate these predictions. Parameter studies on sheet breakup and collapse lengths as well as on breakup and collapse times are reported. The dependence on modulation frequency, modulated disturbance amplitude, Weber number, and annular radius is presented for various cases of the mixed problem, i.e., for linearly or nonlinearly stable and unstable, dilationally or sinusoidally forced sheets. Nonlinear effects often have significant effects on breakup times and lengths or on collapse times and lengths. Nonlinear wave forms can deviate substantially from linear predictions resulting in major impacts on the size of the rings and shells that will remain after breakup.

  5. High energy transmission annular beam X-ray diffraction.

    PubMed

    Dicken, Anthony; Shevchuk, Alex; Rogers, Keith; Godber, Simon; Evans, Paul

    2015-03-01

    We demonstrate material phase retrieval by linearly translating extended polycrystalline samples along the symmetry axis of an annular beam of high-energy X-rays. A series of pseudo-monochromatic diffraction images are recorded from the dark region encompassed by the beam. We measure Bragg maxima from different annular gauge volumes in the form of bright spots in the X-ray diffraction intensity. We present the experiment data from three materials with different crystallographic structural properties i.e. near ideal, large grain size and preferred orientation. This technique shows great promise for analytical inspection tasks requiring highly penetrating radiation such as security screening, medicine and non-destructive testing.

  6. Portal annular pancreas: the pancreatic duct ring sign on MRCP

    PubMed Central

    Lath, Chinar O.; Agrawal, Dilpesh S.; Timins, Michael E.; Wein, Melissa M.

    2015-01-01

    Portal annular pancreas is a rare pancreatic variant in which the uncinate process of the pancreas extends and fuses to the dorsal surface of the body of the pancreas by surrounding the portal vein. It is asymptomatic, but it can be mistaken for a pancreatic head mass on imaging and could also have serious consequences during pancreatic surgery, if unrecognized. We report this case of a 53-year-old female patient who was diagnosed to have portal annular pancreas on the basis of an unusual course (ring appearance) of the main pancreatic duct on magnetic resonance cholangiopancreatography, not described earlier in the radiology literature. PMID:26649117

  7. Research Universities: Core of the U.S. Science and Technology System. Research & Occasional Paper Series: CSHE.5.07

    ERIC Educational Resources Information Center

    Atkinson, Richard C.; Blanpied, William A.

    2007-01-01

    This paper traces the historical development of the American research and technology enterprise from its origins in the post-Civil War period to its current international dominance in the discovery and dissemination of scientific knowledge. U.S. research universities have become the vital center of this enterprise over the past 60 years. But…

  8. Green Infrastructure Research Promotes Students' Deeper Interest in Core Courses of a Water Resources Program

    NASA Astrophysics Data System (ADS)

    Yerk, W.; Montalto, F. A.; Foti, R.

    2015-12-01

    As one of most innovative among low impact development technologies, Green Infrastructure (GI) is a new technology that presents a range of potential research opportunities. Inherently linked to sustainability, urban quality of life, resilience, and other such topics, GI also represents a unique opportunity to highlight the social relevance of practical STEM research to undergraduate students. The nature of research on urban GI, in fact, as well as the accessibility of the GI sites, allows students to combine hands-on experience with theoretical work. Furthermore, the range of scales of the projects is such that they can be managed within a single term, but does not preclude longer engagement. The Sustainable Water Resource Engineering lab at Drexel University is engaged in two types of GI research outside the classroom. One type is a research co-op research internship. The second is a selective university-wide faculty-mentored summer scholarship STAR (Students Tackling Advanced Research) specifically designed for freshmen. The research projects we developed for those curricula can be accomplished by undergraduate students, but also address a larger research need in this emerging field. The research tasks have included identifying and calibrating affordable instruments, designing and building experimental setups, and monitoring and evaluating performance of GI sites. The work also promoted deeper understanding of the hydrological processes and initiated learning beyond the students' current curricula. The practice of the Lab's research being embedded into the educational process receives positive feedback from the students and achieves meaningful and long-lasting learning objectives. The experience helps students to students acquire hands-on experience, improves their metacognition and evidence-based inquiring into real-world problems, and further advances decision-making and communication skills.

  9. NASA Glenn Research Center, Propulsion Systems Laboratory: Plan to Measure Engine Core Flow Water Vapor Content

    NASA Technical Reports Server (NTRS)

    Oliver, Michael

    2014-01-01

    This presentation will be made at the 92nd AIAA Turbine Engine Testing Working Group (TETWoG), a semi-annual technical meeting of turbine engine testing professionals. The objective is to describe an effort by NASA to measure the water vapor content on the core airflow in a full scale turbine engine ice crystal icing test and to open a discussion with colleagues how to accurately conduct the measurement based on any previous collective experience with the procedure, instruments and nature of engine icing testing within the group. The presentation lays out the schematics of the location in the flow path from which the sample will be drawn, the plumbing to get it from the engine flow path to the sensor and several different water vapor measurement technologies that will be used: Tunable diode laser and infrared spectroscopy.

  10. [Research Progress in the Core Proteins of the Classical Swine Fever Virus].

    PubMed

    Hou, Yuzhen; Zhao, Dantong; Liu, Guoying; He, Fan; Liu, Bin; Fu, Shaoyin; Hao, Yongqing; Zhang, Wenguang

    2015-09-01

    The core protein (CP) of the classical swine fever virus (CSFV) is one of its structural proteins. Apart from forming the nucleocapsid to protect internal viral genomic RNA, this protein is involved in transcriptional regulation. Also, during viral infection, the CP is involved in interactions with many host proteins. In this review, we combine study of this protein with its disorders, structural/functional characteristics, as well as its interactions with the non-structural proteins NS3, NS5B and host proteins such as SUMO-1, UBC9, OS9 and IQGAP1. We also summarize the important part played by the CP in CSFV pathogenicity, virulence and replication of genomic RNA. We also provide guidelines for further studies in the CP of the CSFV. PMID:26738299

  11. Multi-functional annular fairing for coupling launch abort motor to space vehicle

    NASA Technical Reports Server (NTRS)

    Camarda, Charles J. (Inventor); Scotti, Stephen J. (Inventor); Buning, Pieter G. (Inventor); Bauer, Steven X. S. (Inventor); Engelund, Walter C. (Inventor); Schuster, David M. (Inventor)

    2011-01-01

    An annular fairing having aerodynamic, thermal, structural and acoustic attributes couples a launch abort motor to a space vehicle having a payload of concern mounted on top of a rocket propulsion system. A first end of the annular fairing is fixedly attached to the launch abort motor while a second end of the annular fairing is attached in a releasable fashion to an aft region of the payload. The annular fairing increases in diameter between its first and second ends.

  12. Uninstrumented assembly airflow testing in the Annular Flow Distribution facility

    SciTech Connect

    Kielpinski, A.L.

    1992-02-01

    During the Emergency Cooling System phase of a postulated large-break loss of coolant accident (ECS-LOCA), air enters the primary loop and is pumped down the reactor assemblies. One of the experiments performed to support the analysis of this accident was the Annular Flow Distribution (AFD) experiment, conducted in a facility built for this purpose at Babcock and Wilcox Alliance Research Center in Alliance, Ohio. As part of this experiment, a large body of airflow data were acquired in a prototypical mockup of the Mark 22 reactor assembly. This assembly was known as the AFD (or the I-AFD here) reference assembly. The I-AFD assembly was fully prototypical, having been manufactured in SRS`s production fabrication facility. Similar Mark 22 mockup assemblies were tested in several test facilities in the SRS Heat Transfer Laboratory (HTL). Discrepancies were found. The present report documents further work done to address the discrepancy in airflow measurements between the AFD facility and HTL facilities. The primary purpose of this report is to disseminate the data from the U-AFD test, and to compare these test results to the I-AFD data and the U-AT data. A summary table of the test data and the B&W data transmittal letter are included as an attachment to this report. The full data transmittal volume from B&W (including time plots of the various instruments) is included as an appendix to this report. These data are further analyzed by comparing them to two other HTL tests, namely, SPRIHTE 1 and the Single Assembly Test Stand (SATS).

  13. Digital controller design: Analysis of the annular suspension pointing system

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The annular suspension and pointing system (ASPS) a payload auxiliary pointing device of the space shuttle is briefly described along with the function of the digital controller. The equations of motion of a simplified plan planar model of the ASPS are derived. Results of computer simulations are discussed.

  14. Design curves for circular and annular duct silencers

    NASA Technical Reports Server (NTRS)

    Watson, Willie R.; Ramakrishnan, R.

    1989-01-01

    Conventional models of sound propagation between porous walls (Scott, 1946) are adapted in order to calculate design curves for the lined circular and annular-duct silencers used in HVAC systems. The derivation of the governing equations is outlined, and results for two typical cases are presented graphically. Good agreement with published experimental data is demonstrated.

  15. Annular linear induction pump with an externally supported duct

    DOEpatents

    Craig, Edwin R.; Semken, Robert S.

    1979-01-01

    Several embodiments of an annular linear induction pump for pumping liquid metals are disclosed having the features of generally one pass flow of the liquid metal through the pump and an increased efficiency resulting from the use of thin duct walls to enclose the stator. The stator components of this pump are removable for repair and replacement.

  16. Fabrication and optical measurement of double-overlapped annular apertures

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Jiang, Xiaoxiao; Xia, Liangping; Tang, Linlong; Hu, Sheng; Lv, Jiangtao; Zhao, Hongquan; Si, Guangyuan; Shi, Ruiying

    2016-10-01

    We demonstrate double-overlapped annular aperture (DOAA) arrays fabricated in a gold film via focused ion beam milling. The high order resonance modes of DOAA are investigated both theoretically and experimentally. Polarization dependency is observed for DOAA arrays and lower order resonance modes in the mid-infrared range exhibit extraordinary optical transmission and dependency on geometric parameters.

  17. Global regularity for MHD Sisko fluid in annular pipe

    NASA Astrophysics Data System (ADS)

    Rahman, S.; Hayat, T.; Ahmad, B.

    2016-08-01

    The flow of Sisko fluid in an annular pipe is considered. The governing nonlinear equation of an incompressible Sisko fluid is modelled. The purpose of present paper is to obtain the global classical solutions for unsteady flow of magnetohydrodynamic Sisko fluid in terms of the bounded mean oscillations norm. Uniqueness of solution is also verified.

  18. RESIDENCE TIME DISTRIBUTION OF FLUIDS IN STIRRED ANNULAR PHOTOREACTORS

    EPA Science Inventory

    When gases flow through an annular photoreactor at constant rate, some of the gas spends more or less than the average residence time in the reactor. This spread of residence time can have an important effect on the performance of the reactor. this study tested how the residence...

  19. Subsonic annular wing theory with application to flow about nacelles

    NASA Technical Reports Server (NTRS)

    Mann, M. J.

    1974-01-01

    A method has recently been developed for calculating the flow over a subsonic nacelle at zero angle of attack. The method makes use of annular wing theory and boundary-layer theory and has shown good agreement with both experimental data and more complex theoretical solutions. The method permits variation of the mass flow by changing the size of a center body.

  20. Stroke Investigative Research and Education Network: Community Engagement and Outreach Within Phenomics Core

    PubMed Central

    Jenkins, Carolyn; Arulogun, Oyedunni Sola; Singh, Arti; Mande, Aliyu T.; Ajayi, Eric; Benedict, Calys Tagoe; Ovbiagele, Bruce; Lackland, Daniel T.; Sarfo, Fred Stephen; Akinyemi, Rufus; Akpalu, Albert; Obiako, Reginald; Melikam, Enzinne Sylvia; Laryea, Ruth; Shidali, Vincent; Sagoe, Kwamena; Ibinaiye, Philip; Fakunle, Adekunie Gregory; Owolabi, Lukman F.; Owolabi, Mayowa O.

    2016-01-01

    Stroke is the leading cause of neurological hospital admissions in sub-Saharan Africa (SSA) and the second leading cause of death globally. The Stroke Investigative Research and Education Network seeks to comprehensively characterize the genomic, sociocultural, economic, and behavioral risk factors for stroke and to build effective teams for research to address and decrease the burden of stroke and other noncommunicable diseases in SSA. One of the first steps to address this goal is to effectively engage the communities that suffer the high burden of disease. The purpose of this article is to describe plans to elucidate information about knowledge, attitudes, beliefs, and practices about stroke and genomics from patients, caregivers, and local leaders, to recruit participation in research activities and dissemination of ongoing results, as well as to facilitate research uptake and impact within the broader communities of scientists, health professionals, policy makers, and others. We describe the (a) study sites and their communities; (b) plans for community advisory boards, focus groups, and surveys; (c) methods for data management in REDCap database; (d) analyses of qualitative data; (e) evaluation of community and public engagement across multiple sites and research teams in SSA and the United States; (f) use of RE-AIM for presentation of evaluation data; and (g) community indicators of success. This is the first of its kind public outreach engagement initiative to evaluate stroke and genomics in SSA, and has implications as a model for assessment in other high–stroke risk populations. PMID:27037152

  1. Stroke Investigative Research and Education Network: Community Engagement and Outreach Within Phenomics Core.

    PubMed

    Jenkins, Carolyn; Arulogun, Oyedunni Sola; Singh, Arti; Mande, Aliyu T; Ajayi, Eric; Benedict, Calys Tagoe; Ovbiagele, Bruce; Lackland, Daniel T; Sarfo, Fred Stephen; Akinyemi, Rufus; Akpalu, Albert; Obiako, Reginald; Melikam, Enzinne Sylvia; Laryea, Ruth; Shidali, Vincent; Sagoe, Kwamena; Ibinaiye, Philip; Fakunle, Adekunie Gregory; Owolabi, Lukman F; Owolabi, Mayowa O

    2016-04-01

    Stroke is the leading cause of neurological hospital admissions in sub-Saharan Africa (SSA) and the second leading cause of death globally. The Stroke Investigative Research and Education Network seeks to comprehensively characterize the genomic, sociocultural, economic, and behavioral risk factors for stroke and to build effective teams for research to address and decrease the burden of stroke and other noncommunicable diseases in SSA. One of the first steps to address this goal is to effectively engage the communities that suffer the high burden of disease. The purpose of this article is to describe plans to elucidate information about knowledge, attitudes, beliefs, and practices about stroke and genomics from patients, caregivers, and local leaders, to recruit participation in research activities and dissemination of ongoing results, as well as to facilitate research uptake and impact within the broader communities of scientists, health professionals, policy makers, and others. We describe the (a) study sites and their communities; (b) plans for community advisory boards, focus groups, and surveys; (c) methods for data management in REDCap database; (d) analyses of qualitative data; (e) evaluation of community and public engagement across multiple sites and research teams in SSA and the United States; (f) use of RE-AIM for presentation of evaluation data; and (g) community indicators of success. This is the first of its kind public outreach engagement initiative to evaluate stroke and genomics in SSA, and has implications as a model for assessment in other high-stroke risk populations. PMID:27037152

  2. Research for a multi-modal mobility and manipulation propulsion core

    NASA Astrophysics Data System (ADS)

    Edge, Harris; Collins, Jason

    2015-05-01

    There are many challenges for robotics, many of which may be placed in the context of robots acting as a teammate to Soldiers. In general one may see a robotic teammate as an unmanned system that complements a Soldier's capability, may perform some of the duties of a Soldier, or may actually protect the Soldier. There is much research that needs to be performed before robots are physically capable of performing as teammates to Soldiers in dynamic environments where speed matters, and in complex 3-D environments where navigation for today's robots is difficult. This research addresses a fundamental obstacle to addressing this issue, which is how to safely and cost effectively develop theory and controls for a new generation of robots that may operate at operations tempo (OPTEMPO) in dynamic complex 3-D environments. This paper documents design and fabrication of a research platform capable of demonstrating theory and control algorithms developed for highly dynamic robotics systems, which may need to navigate and perform a task in complex 3-D environments. The research platform has been designed to address challenging basic research in the areas of airborne manipulation, transition to and interaction with vertical surfaces, exploration of a constrained space such as urban environments (street level to rooftop), forests, and underground facilities. The platform will allow controls development and validation for a vehicle that's weight is at least partially supported by a propulsion system to perform work on the environment and/or an object within the environment.

  3. Unscrambling Mixed Elements using High Angle Annular Dark Field Scanning Transmission Electron Microscopy

    NASA Astrophysics Data System (ADS)

    van den Bos, Karel H. W.; De Backer, Annick; Martinez, Gerardo T.; Winckelmans, Naomi; Bals, Sara; Nellist, Peter D.; Van Aert, Sandra

    2016-06-01

    The development of new nanocrystals with outstanding physicochemical properties requires a full three-dimensional (3D) characterization at the atomic scale. For homogeneous nanocrystals, counting the number of atoms in each atomic column from high angle annular dark field scanning transmission electron microscopy images has been shown to be a successful technique to get access to this 3D information. However, technologically important nanostructures often consist of more than one chemical element. In order to extend atom counting to heterogeneous materials, a new atomic lensing model is presented. This model takes dynamical electron diffraction into account and opens up new possibilities for unraveling the 3D composition at the atomic scale. Here, the method is applied to determine the 3D structure of Au@Ag core-shell nanorods, but it is applicable to a wide range of heterogeneous complex nanostructures.

  4. Unscrambling Mixed Elements using High Angle Annular Dark Field Scanning Transmission Electron Microscopy.

    PubMed

    van den Bos, Karel H W; De Backer, Annick; Martinez, Gerardo T; Winckelmans, Naomi; Bals, Sara; Nellist, Peter D; Van Aert, Sandra

    2016-06-17

    The development of new nanocrystals with outstanding physicochemical properties requires a full three-dimensional (3D) characterization at the atomic scale. For homogeneous nanocrystals, counting the number of atoms in each atomic column from high angle annular dark field scanning transmission electron microscopy images has been shown to be a successful technique to get access to this 3D information. However, technologically important nanostructures often consist of more than one chemical element. In order to extend atom counting to heterogeneous materials, a new atomic lensing model is presented. This model takes dynamical electron diffraction into account and opens up new possibilities for unraveling the 3D composition at the atomic scale. Here, the method is applied to determine the 3D structure of Au@Ag core-shell nanorods, but it is applicable to a wide range of heterogeneous complex nanostructures.

  5. Research subjects for analytical estimation of core degradation at Fukushima-Daiichi nuclear power plant

    SciTech Connect

    Nagase, F.; Ishikawa, J.; Kurata, M.; Yoshida, H.; Kaji, Y.; Shibamoto, Y.; Amaya, M; Okumura, K.; Katsuyama, J.

    2013-07-01

    Estimation of the accident progress and status inside the pressure vessels (RPV) and primary containment vessels (PCV) is required for appropriate conductance of decommissioning in the Fukushima-Daiichi NPP. For that, it is necessary to obtain additional experimental data and revised models for the estimation using computer codes with increased accuracies. The Japan Atomic Energy Agency (JAEA) has selected phenomena to be reviewed and developed, considering previously obtained information, conditions specific to the Fukushima-Daiichi NPP accident, and recent progress of experimental and analytical technologies. As a result, research and development items have been picked up in terms of thermal-hydraulic behavior in the RPV and PCV, progression of fuel bundle degradation, failure of the lower head of RPV, and analysis of the accident. This paper introduces the selected phenomena to be reviewed and developed, research plans and recent results from the JAEA's corresponding research programs. (authors)

  6. Applying the Learning Community Model to Graduate Education: Linking Research and Teaching between Core Courses

    ERIC Educational Resources Information Center

    Romsdahl, Rebecca J.; Hill, Michael J.

    2012-01-01

    In graduate education, there is often a great divide between classroom learning and research endeavors. Using learning community (LC) values and strategies, our goal is to build stronger and more meaningful ties between these two aspects of graduate education so that students see them as complimentary learning rather than separate components. This…

  7. Use of Research-Based Instructional Strategies in Core Chemical Engineering Courses

    ERIC Educational Resources Information Center

    Prince, Michael; Borrego, Maura; Henderson, Charles; Cutler, Stephanie; Froyd, Jeff

    2013-01-01

    Traditional lecturing remains the most prevalent mode of instruction despite overwhelming research showing the increased effectiveness of many alternate instructional strategies. This study examines chemical engineering instructors' awareness and use of 12 such instructional strategies. The study also examines how chemical engineering…

  8. CPTC expand scope of Reagents and Resources Core - Office of Cancer Clinical Proteomics Research

    Cancer.gov

    Whether in determining if a women is pregnant or not by measuring human chorionic gonadotropin or determining whether someone is HIV positive, antibodies and other affinity reagents play a key role both in diagnostic decision making and advancing the research field.

  9. Stroke Investigative Research and Education Network: Community Engagement and Outreach within Phenomics Core

    ERIC Educational Resources Information Center

    Jenkins, Carolyn; Arulogun, Oyedunni Sola; Singh, Arti; Mande, Aliyu T.; Ajayi, Eric; Benedict, Calys Tagoe; Ovbiagele, Bruce; Lackland, Daniel T.; Sarfo, Fred Stephen; Akinyemi, Rufus; Akpalu, Albert; Obiako, Reginald; Melikam, Enzinne Sylvia; Laryea, Ruth; Shidali, Vincent; Sagoe, Kwamena; Ibinaiye, Philip; Fakunle, Adekunie Gregory; Owolabi, Lukman F.; Owolabi, Mayowa O.

    2016-01-01

    Stroke is the leading cause of neurological hospital admissions in sub-Saharan Africa (SSA) and the second leading cause of death globally. The Stroke Investigative Research and Education Network [SIREN] seeks to comprehensively characterize the genomic, sociocultural, economic, and behavioral risk factors for stroke and to build effective teams…

  10. Improving Middle School Parental Engagement in Transition to Common Core State Standards: An Action Research Study

    ERIC Educational Resources Information Center

    Harla, Donna K.

    2014-01-01

    Parental involvement in schools is an important potential contributor to improving American education and making the U.S. more globally competitive. This qualitative and quantitative mixed-methodology action research study probed the viability of engaging parents around issues of educational improvement by inviting them to participate in training…

  11. Ultrafast laser parallel microdrilling using multiple annular beams generated by a spatial light modulator

    NASA Astrophysics Data System (ADS)

    Kuang, Zheng; Perrie, Walter; Edwardson, Stuart P.; Fearon, Eamonn; Dearden, Geoff

    2014-03-01

    Ultrafast laser parallel microdrilling using diffractive multiple annular beam patterns is demonstrated in this paper. The annular beam was generated by diffractive axicon computer generated holograms (CGHs) using a spatial light modulator. The diameter of the annular beam can be easily adjusted by varying the radius of the smallest ring in the axicon. Multiple annular beams with arbitrary arrangement and multiple annular beam arrays were generated by superimposing an axicon CGH onto a grating and lenses algorithm calculated multi-beam CGH and a binary Dammann grating CGH, respectively. Microholes were drilled through a 0.03 mm thick stainless steel foil using the multiple annular beams. By avoiding huge laser output attenuation and mechanical annular scanning, the processing is ˜200 times faster than the normal single beam processing.

  12. Support for the Core Research Activities and Studies of the Computer Science and Telecommunications Board (CSTB)

    SciTech Connect

    Jon Eisenberg, Director, CSTB

    2008-05-13

    The Computer Science and Telecommunications Board of the National Research Council considers technical and policy issues pertaining to computer science (CS), telecommunications, and information technology (IT). The functions of the board include: (1) monitoring and promoting the health of the CS, IT, and telecommunications fields, including attention as appropriate to issues of human resources and funding levels and program structures for research; (2) initiating studies involving CS, IT, and telecommunications as critical resources and sources of national economic strength; (3) responding to requests from the government, non-profit organizations, and private industry for expert advice on CS, IT, and telecommunications issues; and to requests from the government for expert advice on computer and telecommunications systems planning, utilization, and modernization; (4) fostering interaction among CS, IT, and telecommunications researchers and practitioners, and with other disciplines; and providing a base of expertise in the National Research Council in the areas of CS, IT, and telecommunications. This award has supported the overall operation of CSTB. Reports resulting from the Board's efforts have been widely disseminated in both electronic and print form, and all CSTB reports are available at its World Wide Web home page at cstb.org. The following reports, resulting from projects that were separately funded by a wide array of sponsors, were completed and released during the award period: 2007: * Summary of a Workshop on Software-Intensive Systems and Uncertainty at Scale * Social Security Administration Electronic Service Provision: A Strategic Assessment * Toward a Safer and More Secure Cyberspace * Software for Dependable Systems: Sufficient Evidence? * Engaging Privacy and Information Technology in a Digital Age * Improving Disaster Management: The Role of IT in Mitigation, Preparedness, Response, and Recovery 2006: * Renewing U.S. Telecommunications Research

  13. Annular fuel and air co-flow premixer

    DOEpatents

    Stevenson, Christian Xavier; Melton, Patrick Benedict; York, William David

    2013-10-15

    Disclosed is a premixer for a combustor including an annular outer shell and an annular inner shell. The inner shell defines an inner flow channel inside of the inner shell and is located to define an outer flow channel between the outer shell and the inner shell. A fuel discharge annulus is located between the outer flow channel and the inner flow channel and is configured to inject a fuel flow into a mixing area in a direction substantially parallel to an outer airflow through the outer flow channel and an inner flow through the inner flow channel. Further disclosed are a combustor including a plurality of premixers and a method of premixing air and fuel in a combustor.

  14. Analysis of Enriched Uranyl Nitrate in Nested Annular Tank Array

    SciTech Connect

    John D. Bess; James D. Cleaver

    2009-06-01

    Two series of experiments were performed at the Rocky Flats Critical Mass Laboratory during the 1980s using highly enriched (93%) uranyl nitrate solution in annular tanks. [1, 2] Tanks were of typical sizes found in nuclear production plants. Experiments looked at tanks of varying radii in a co-located set of nested tanks, a 1 by 2 array, and a 1 by 3 array. The co-located set of tanks had been analyzed previously [3] as a benchmark for inclusion within the International Handbook of Evaluated Criticality Safety Benchmark Experiments. [4] The current study represents the benchmark analysis of the 1 by 3 array of a series of nested annular tanks. Of the seventeen configurations performed in this set of experiments, twelve were evaluated and nine were judged as acceptable benchmarks.

  15. Energy and Exergy Analysis of an Annular Thermoelectric Heat Pump

    NASA Astrophysics Data System (ADS)

    Kaushik, S. C.; Manikandan, S.; Hans, Ranjana

    2016-07-01

    In this paper, the concept of an annular thermoelectric heat pump (ATEHP) has been introduced. An exoreversible thermodynamic model of the ATEHP considering the Thomson effect in conjunction with Peltier, Joule and Fourier heat conduction has been investigated using exergy analysis. New expressions for dimensionless heating power, optimum current at the maximum energy, exergy efficiency conditions and dimensionless irreversibilities in the ATEHP are derived. The results show that the heating power, energy and exergy efficiency of the ATEHP are lower than the flat-plate thermoelectric heat pump. The effects of annular shape parameter ( S r = r 2 /r 1), dimensionless temperature ratio ( θ = T h /T c) and the electrical contact resistances on the heating power, energy/exergy efficiency of an ATEHP have been studied. This study will help in the designing of actual ATEHP systems.

  16. Long-Distance Axial Trapping with Focused Annular Laser Beams

    PubMed Central

    Yan, Shaohui; Yao, Baoli; Dan, Dan; Qi, Yujiao; Qian, Jia; Yang, Yanlong; Gao, Peng; Ye, Tong

    2013-01-01

    Focusing an annular laser beam can improve the axial trapping efficiency due to the reduction of the scattering force, which enables the use of a lower numerical aperture (NA) objective lens with a long working distance to trap particles in deeper aqueous medium. In this paper, we present an axicon-to-axicon scheme for producing parallel annular beams with the advantages of higher efficiency compared with the obstructed beam approach. The validity of the scheme is verified by the observation of a stable trapping of silica microspheres with relatively low NA microscope objective lenses (NA = 0.6 and 0.45), and the axial trapping depth of 5 mm is demonstrated in experiment. PMID:23505449

  17. Mixtures of Bose gases confined in concentrically coupled annular traps

    SciTech Connect

    Malet, F.; Reimann, S. M.; Kavoulakis, G. M.

    2010-01-15

    A two-component Bose-Einstein condensate confined in an axially symmetric potential with two local minima, resembling two concentric annular traps, is investigated. The system shows a number of phase transitions that result from the competition between phase coexistence and radial-azimuthal phase separation. The ground-state phase diagram, as well as the rotational properties, including the (meta)stability of currents in this system, is analyzed.

  18. Hydraulic forces caused by annular pressure seals in centrifugal pumps

    NASA Technical Reports Server (NTRS)

    Iino, T.; Kaneko, H.

    1980-01-01

    The hydraulic forces caused by annular pressure seals were investigated. The measured inlet and exit loss coefficients of the flow through the seals were much smaller than the conventional values. The results indicate that the damping coefficient and the inertia coefficient of the fluid film in the seal are not affected much by the rotational speed or the eccentricity of the rotor, though the stiffness coefficient seemed to be influenced by the eccentricity.

  19. System design of the annular suspension and pointing system /ASPS/

    NASA Technical Reports Server (NTRS)

    Cunningham, D. C.; Gismondi, T. P.; Wilson, G. W.

    1978-01-01

    This paper presents the control system design for the Annular Suspension and Pointing System. Actuator sizing and configuration of the system are explained, and the control laws developed for linearizing and compensating the magnetic bearings, roll induction motor and gimbal torquers are given. Decoupling, feedforward and error compensation for the vernier and gimbal controllers is developed. The algorithm for computing the strapdown attitude reference is derived, and the allowable sampling rates, time delays and quantization of control signals are specified.

  20. Photoacoustic tomography with integrating fiber-based annular detectors

    NASA Astrophysics Data System (ADS)

    Grün, H.; Altmisdört, H.; Berer, T.; Paltauf, G.; Zangerl, G.; Haltmeier, M.; Burgholzer, P.

    2011-03-01

    Photoacoustic tomography is an emerging technology combining the advantages of optical imaging (high contrast) and ultrasonic imaging (high spatial resolution). Applications for photoacoustic tomography are mainly in imaging soft tissue. For photoacoustic imaging the sample is illuminated by a short pulse of electromagnetic energy. Depending on the specific absorption rate (SAR) the electromagnetic radiation is absorbed and the subsequent thermoelastic expansion launches broadband ultrasonic waves. Usually point like piezo-electric detectors are used. Our group introduced integrating detectors a few years ago. This type of detector integrates the pressure at least along one dimension. Integrating line detectors, which integrate the pressure along one dimension, can be realized by using either free-beam or fiber-based interferometers. The latter approach also allows other detector shapes than a line. In this paper we use a fiber-based annular detector for tomography. Thereby the sample is rotated inside the annular detector on a position different from the symmetry axis of the annular detector. Hence the sample is enclosed by the detector and all data from one plane are collected at once. By moving the detector parallel to the symmetrie axis of the ring one can acquire data for a 3D image reconstruction. Therfore, tomography can be performed with only one rotation axis and one translation axis. For image reconstruction a novel algorithm is necessary which was tested on simulated data. Here we present an imaging setup using such a fiber-based annular detector. First measurements of simple structures and subsequent image reconstruction from these real data are shown in this paper.

  1. Persistent currents in Bose gases confined in annular traps

    SciTech Connect

    Bargi, S.; Malet, F.; Reimann, S. M.; Kavoulakis, G. M.

    2010-10-15

    We examine the problem of stability of persistent currents in a mixture of two Bose gases trapped in an annular potential. We evaluate the critical coupling for metastability in the transition from quasi-one- to two-dimensional motion. We also evaluate the critical coupling for metastability in a mixture of two species as a function of the population imbalance. The stability of the currents is shown to be sensitive to the deviation from one-dimensional motion.

  2. Annular Momentum Control Device (AMCD). Volume 1: Laboratory model development

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The annular momentum control device (AMCD) a thin hoop-like wheel with neither shaft nor spokes is described. The wheel floats in a magnetic field and can be rotated by a segmented motor. Potential advantages of such a wheel are low weight, configuration flexibility, a wheel that stiffens with increased speed, vibration isolation, and increased reliability. The analysis, design, fabrication, and testing is described of the laboratory model of the AMCD.

  3. Multifocal Annular Tufted Angioma: An Uncommon Clinical Entity

    PubMed Central

    Bandyopadhyay, Debabrata; Saha, Abanti

    2015-01-01

    Tufted angioma (TA) is a localized benign hamartomatous vascular proliferation usually presenting in the childhood as an erythematous plaque. We report here a rare case of multifocal TA in an 8-year-old boy who presented which two large annular lesions as well as multiple papules and nodules on the back for the duration of 4 years. Histology showed typical well circumscribed poorly canalized vascular lobules with ‘cannon ball’ configuration. PMID:26288441

  4. Critical-current diffraction pattern of annular Josephson junctions

    NASA Astrophysics Data System (ADS)

    Nappi, Ciro

    1997-01-01

    A derivation of the exact analytical expressions for the critical current versus magnetic-field-diffraction pattern of ``electrically'' small annular Josephson junctions is presented. These formulas have been recently used to fit experimental data [N. Martucciello and R. Monaco, Phys. Rev. B 54, 9050 (1996)]. They include, as a special case, the approximate analytical results previously published [N. Martucciello and R. Monaco, Phys. Rev. B 53 3471 (1996)].

  5. The method of characteristics and computational fluid dynamics applied to the prediction of underexpanded jet flows in annular geometry

    NASA Astrophysics Data System (ADS)

    Kim, Sangwon

    2005-11-01

    High pressure (3.4 MPa) injection from a shroud valve can improve natural gas engine efficiency by enhancing fuel-air mixing. Since the fuel jet issuing from the shroud valve has a nearly annular jet flow configuration, it is necessary to analyze the annular jet flow to understand the fuel jet behavior in the mixing process and to improve the shroud design for better mixing. The method of characteristics (MOC) was used as the primary modeling algorithm in this work and Computational Fluid Dynamics (CFD) was used primarily to validate the MOC results. A consistent process for dealing with the coalescence of compression characteristic lines into a shock wave during the MOC computation was developed. By the application of shock polar in the pressure-flow angle plane to the incident shock wave for an axisymmetric underexpanded jet and the comparison with the triple point location found in experimental results, it was found that, in the static pressure ratios of 2--50, a triple point of the jet was located at the point where the flow angle after the incident shock became -5° relative to the axis and this point was situated between the von Neumann and detachment criteria on the incident shock. MOC computations of the jet flow with annular geometry were performed for pressure ratios of 10 and 20 with rannulus = 10--50 units, Deltar = 2 units. In this pressure ratio range, the MOC results did not predict a Mach disc in the core flow of the annular jet, but did indicate the formation of a Mach disc where the jet meets the axis of symmetry. The MOC results display the annular jet configurations clearly. Three types of nozzles for application to gas injectors (convergent-divergent nozzle, conical nozzle, and aerospike nozzle) were designed using the MOC and evaluated in on- and off-design conditions using CFD. The average axial momentum per unit mass was improved by 17 to 24% and the average kinetic energy per unit fuel mass was improved by 30 to 80% compared with a standard

  6. Standing wave acoustic levitation on an annular plate

    NASA Astrophysics Data System (ADS)

    Kandemir, Mehmet Hakan; Çalışkan, Mehmet

    2016-11-01

    In standing wave acoustic levitation technique, a standing wave is formed between a source and a reflector. Particles can be attracted towards pressure nodes in standing waves owing to a spring action through which particles can be suspended in air. This operation can be performed on continuous structures as well as in several numbers of axes. In this study an annular acoustic levitation arrangement is introduced. Design features of the arrangement are discussed in detail. Bending modes of the annular plate, known as the most efficient sound generation mechanism in such structures, are focused on. Several types of bending modes of the plate are simulated and evaluated by computer simulations. Waveguides are designed to amplify waves coming from sources of excitation, that are, transducers. With the right positioning of the reflector plate, standing waves are formed in the space between the annular vibrating plate and the reflector plate. Radiation forces are also predicted. It is demonstrated that small particles can be suspended in air at pressure nodes of the standing wave corresponding to a particular bending mode.

  7. Annular tautomerism: experimental observations and quantum mechanics calculations.

    PubMed

    Cruz-Cabeza, Aurora J; Schreyer, Adrian; Pitt, William R

    2010-06-01

    The use of MP2 level quantum mechanical (QM) calculations on isolated heteroaromatic ring systems for the prediction of the tautomeric propensities of whole molecules in a crystalline environment was examined. A Polarisable Continuum Model was used in the calculations to account for environment effects on the tautomeric relative stabilities. The calculated relative energies of tautomers were compared to relative abundances within the Cambridge Structural Database (CSD) and the Protein Data Bank (PDB). The work was focussed on 84 annular tautomeric forms of 34 common ring systems. Good agreement was found between the calculations and the experimental data even if the quantity of these data was limited in many cases. The QM results were compared to those produced by much faster semiempirical calculations. In a search for other sources of the useful experimental data, the relative numbers of known compounds in which prototropic positions were often substituted by heavy atoms were also analysed. A scheme which groups all annular tautomeric transformations into 10 classes was developed. The scheme was designed to encompass a comprehensive set of known and theoretically possible tautomeric ring systems generated as part of a previous study. General trends across analogous ring systems were detected as a result. The calculations and statistics collected on crystallographic data as well as the general trends observed should be useful for the better modelling of annular tautomerism in the applications such as computer-aided drug design, small molecule crystal structure prediction, the naming of compounds and the interpretation of protein-small molecule crystal structures.

  8. The annular flow electrothermal ramjet. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Shaw, B. D.

    1984-01-01

    The annular flow, electrothermal, plug ramjet is examined as a possible means of achieving rapid projectile acceleration to velocities for such applications as direct launch of spacebound payloads. The performance of this ramjet operating with hydrogen propellant is examined for cases where this working fluid is treated: (1) as a perfect gas, and (2) as a gas that is allowed to dissociate and ionize and then recombine with finite reaction rates in the nozzle. Performance results for these cases are compared to the performance of a conventional ramjet operating with perfect gas hydrogen propellant. The performance of the conventional ramjet is superior to that of the annular flow, electrothermal ramjet. However, it is argued that the mechanical complexities associated with conventional ramjet operation are difficult to attain, and for this reason the annular flow, electrothermal ramjet is more desirable as a launch system. Models are presented which describe both electrothermal plug ramjet and conventional ramjet operation, and it is shown that for a given flight velocity there is a rate of heat addition per unit propellant mass for which ramjet operation is optimized.

  9. Slim hole MWD tool accurately measures downhole annular pressure

    SciTech Connect

    Burban, B.; Delahaye, T. )

    1994-02-14

    Measurement-while-drilling of downhole pressure accurately determines annular pressure losses from circulation and drillstring rotation and helps monitor swab and surge pressures during tripping. In early 1993, two slim-hole wells (3.4 in. and 3 in. diameter) were drilled with continuous real-time electromagnetic wave transmission of downhole temperature and annular pressure. The data were obtained during all stages of the drilling operation and proved useful for operations personnel. The use of real-time measurements demonstrated the characteristic hydraulic effects of pressure surges induced by drillstring rotation in the small slim-hole annulus under field conditions. The interest in this information is not restricted to the slim-hole geometry. Monitoring or estimating downhole pressure is a key element for drilling operations. Except in special cases, no real-time measurements of downhole annular pressure during drilling and tripping have been used on an operational basis. The hydraulic effects are significant in conventional-geometry wells (3 1/2-in. drill pipe in a 6-in. hole). This paper describes the tool and the results from the field test.

  10. Treatment of generalized granuloma annulare - a systematic review.

    PubMed

    Lukács, J; Schliemann, S; Elsner, P

    2015-08-01

    Granuloma annulare (GA) is a benign inflammatory skin disease. Localized GA is likely to resolve spontaneously, while generalized GA (GGA) is rare and may persist for decades. GGA usually is resistant to a variety of therapeutic modalities and takes a chronic course. The objective of this study was to summarize all reported treatments of generalized granuloma annulare. This is a systematic review based on MEDLINE, Embase and Cochrane Central Register search of articles in English and German and a manual search, between 1980 and 2013, to summarize the treatment of generalized granuloma annulare. Most medical literature on treatment of GGA is limited to individual case reports and small series of patients treated without a control group. Randomized controlled clinical studies are missing. Multiple treatment modalities for GGA were reported including topical and systemic steroids, PUVA, isotretinoin, dapsone, pentoxifylline, hydroxychloroquine, cyclosporine, IFN-γ, potassium iodide, nicotinamide, niacinamide, salicylic acid, dipyridamole, PDT, fumaric acid ester, etanercept, infliximab, adalimumab. While there are numerous case reports of successful treatments in the literature including surgical, medical and phototherapy options, well-designed, randomized, controlled clinical trials are required for an evidence-based treatment of GGA. PMID:25651003

  11. Guided Wave Annular Array Sensor Design for Improved Tomographic Imaging

    NASA Astrophysics Data System (ADS)

    Koduru, Jaya Prakash; Rose, Joseph L.

    2009-03-01

    Guided wave tomography for structural health monitoring is fast emerging as a reliable tool for the detection and monitoring of hotspots in a structure, for any defects arising from corrosion, crack growth etc. To date guided wave tomography has been successfully tested on aircraft wings, pipes, pipe elbows, and weld joints. Structures practically deployed are subjected to harsh environments like exposure to rain, changes in temperature and humidity. A reliable tomography system should take into account these environmental factors to avoid false alarms. The lack of mode control with piezoceramic disk sensors makes it very sensitive to traces of water leading to false alarms. In this study we explore the design of annular array sensors to provide mode control for improved structural tomography, in particular, addressing the false alarm potential of water loading. Clearly defined actuation lines in the phase velocity dispersion curve space are calculated. A dominant in-plane displacement point is found to provide a solution to the water loading problem. The improvement in the tomographic images with the annular array sensors in the presence of water traces is clearly illustrated with a series of experiments. An annular array design philosophy for other problems in NDE/SHM is also discussed.

  12. Design, construction and testing of annular diffusers for high speed civil transportation combustor applications

    NASA Astrophysics Data System (ADS)

    Okhio, Cyril B.

    1995-08-01

    A theoretical and an experimental design study of subsonic flow through curved-wall annular diffusers is being carried out in order to establish the most pertinent design parameters for such devices and the implications of their application in the design of engine components in the aerospace industries. This investigation consists of solving numerically the full Navier Stokes and Continuity equations for the time-mean flow. Various models of turbulence are being evaluated for adoption throughout the study and comparisons would be made with experimental data where they exist. Assessment of diffuser performance based on the dissipated mechanical energy would also be made. The experimental work involves the application of Computer Aided Design software tool to the development of a suitable annular diffuser geometry and the subsequent downloading of such data to a CNC machine at Central State University. The results of the investigations are expected to indicate that more cost effective component design of such devices as effective component design of such devices as diffusers which normally contain complex flows can still be achieved. In this regard a review paper was accepted and presented at the First International Conference on High Speed Civil Transportation Research held at North Carolina A&T in December of 1994.

  13. Design, construction and testing of annular diffusers for high speed civil transportation combustor applications

    NASA Technical Reports Server (NTRS)

    Okhio, Cyril B.

    1995-01-01

    A theoretical and an experimental design study of subsonic flow through curved-wall annular diffusers is being carried out in order to establish the most pertinent design parameters for such devices and the implications of their application in the design of engine components in the aerospace industries. This investigation consists of solving numerically the full Navier Stokes and Continuity equations for the time-mean flow. Various models of turbulence are being evaluated for adoption throughout the study and comparisons would be made with experimental data where they exist. Assessment of diffuser performance based on the dissipated mechanical energy would also be made. The experimental work involves the application of Computer Aided Design software tool to the development of a suitable annular diffuser geometry and the subsequent downloading of such data to a CNC machine at Central State University. The results of the investigations are expected to indicate that more cost effective component design of such devices as effective component design of such devices as diffusers which normally contain complex flows can still be achieved. In this regard a review paper was accepted and presented at the First International Conference on High Speed Civil Transportation Research held at North Carolina A&T in December of 1994.

  14. Static and transient performance of YF-102 engine with up to 14 percent core airbleed for the quiet short-haul research aircraft

    NASA Technical Reports Server (NTRS)

    Mcardle, J. G.; Homyak, L.; Moore, A. S.

    1980-01-01

    An outdoor static test stand was used to measure the steady-state and transient performance of the YF-102 turbofan engine with core airbleed. The test configuration included a bellmouth inlet and a confluent-flow exhaust system similar in size to the quiet short-haul research aircraft (QSRA) exhaust system. For the steady-state tests, the engine operated satisfactorily with core bleed up to 14 percent of the core inlet flow. For the transient tests the engine accelerated and decelerated satisfactorily with no core bleed and with core bleed up to 11 percent of the core inlet flow (maximum tested). For some of the tests the core-bleed flow rate was scheduled to vary with fan discharge pressure, to simulate the QSRA bleed requirements. No stability, surge, stall, overtemperature, combustor flameout, or other operating problems were encountered in any of the tests. Steady-state and transient engine performance data are presented in graphs, and fuel-control trajectories for typical transient tests are shown.

  15. Ultrasonic guided waves in eccentric annular pipes

    SciTech Connect

    Pattanayak, Roson Kumar; Balasubramaniam, Krishnan; Rajagopal, Prabhu

    2014-02-18

    This paper studies the feasibility of using ultrasonic guided waves to rapidly inspect tubes and pipes for possible eccentricity. While guided waves are well established in the long range inspection of structures such as pipes and plates, studies for more complex cross sections are limited and analytical solutions are often difficult to obtain. Recent developments have made the Semi Analytical Finite Element (SAFE) method widely accessible for researchers to study guided wave properties in complex structures. Here the SAFE method is used to study the effect of eccentricity on the modal structures and velocities of lower order guided wave modes in thin pipes of diameters typically of interest to the industry. Results are validated using experiments. The paper demonstrates that even a small eccentricity in the pipe can strongly affect guided wave mode structures and velocities and hence shows potential for pipe eccentricity inspection.

  16. Ultrasonic guided waves in eccentric annular pipes

    NASA Astrophysics Data System (ADS)

    Pattanayak, Roson Kumar; Balasubramaniam, Krishnan; Rajagopal, Prabhu

    2014-02-01

    This paper studies the feasibility of using ultrasonic guided waves to rapidly inspect tubes and pipes for possible eccentricity. While guided waves are well established in the long range inspection of structures such as pipes and plates, studies for more complex cross sections are limited and analytical solutions are often difficult to obtain. Recent developments have made the Semi Analytical Finite Element (SAFE) method widely accessible for researchers to study guided wave properties in complex structures. Here the SAFE method is used to study the effect of eccentricity on the modal structures and velocities of lower order guided wave modes in thin pipes of diameters typically of interest to the industry. Results are validated using experiments. The paper demonstrates that even a small eccentricity in the pipe can strongly affect guided wave mode structures and velocities and hence shows potential for pipe eccentricity inspection.

  17. Apparatus for controlling nuclear core debris

    DOEpatents

    Jones, Robert D.

    1978-01-01

    Nuclear reactor apparatus for containing, cooling, and dispersing reactor debris assumed to flow from the core area in the unlikely event of an accident causing core meltdown. The apparatus includes a plurality of horizontally disposed vertically spaced plates, having depressions to contain debris in controlled amounts, and a plurality of holes therein which provide natural circulation cooling and a path for debris to continue flowing downward to the plate beneath. The uppermost plates may also include generally vertical sections which form annular-like flow areas which assist the natural circulation cooling.

  18. High pressure annular two-phase flow in a narrow duct. Part 1: Local measurements in the droplet field, and Part 2: Three-field modeling

    SciTech Connect

    Trabold, T.A.; Kumar, R.

    1999-07-01

    In Part 1, detailed measurements were made in a high pressure, adiabatic (boiled at the inlet) annular flow in a narrow, high aspect ratio duct using a gamma densitometer, hot-film anemometer and high-speed video photography. Measurements of void fraction, droplet frequency, velocity, drop size, and interfacial area concentration have been made to support the three field computational capability. An important aspect of this testing is the use of a modeling fluid (R-134a) in a vertical duct which permits visual access in annular flow. This modeling fluid accurately simulates the low liquid-to-vapor density ratio of steam-water flows at high pressures. These measurements have been taken in a narrow duct of hydraulic diameter 4.85 mm, and a cross-section aspect ratio of 22.5. However, the flow displays profiles of various shapes not only in the narrow dimension, but also in the width dimension. In particular, the shape of the droplet profiles depends on the entrained droplet flux from the edges in the vapor core. The average diameter from these profiles compare well with the models developed in the literature. Interfacial area concentration for these low density ratio flows is higher than the highest concentration reported for air-water flows. Video records show that along with the bow-shaped waves, three-dimensional {lambda}-shaped waves appear in annular flows for high flow rates. Part 2 outlines the development of a three-field modeling approach in annular flow and the predictive capability of an analysis code. Models have been developed here or adapted from the literature for the thin film near the wall as well as the droplets in the vapor core, and have been locally applied in a fully developed, two-phase adiabatic boiling annular flow in a duct heated at the inlet at high pressure. Numerical results have been obtained using these models that are required for the closure of the continuity and momentum equations. The two-dimensional predictions are compared with

  19. Identification of a Core Set of Exercise Tests for Children and Adolescents with Cerebral Palsy: A Delphi Survey of Researchers and Clinicians

    ERIC Educational Resources Information Center

    Verschuren, Olaf; Ketelaar, Marjolijn; Keefer, Daniel; Wright, Virginia; Butler, Jane; Ada, Louise; Maher, Carol; Reid, Siobhan; Wright, Marilyn; Dalziel, Blythe; Wiart, Lesley; Fowler, Eileen; Unnithan, Viswanath; Maltais, Desiree B.; van den Berg-Emons, Rita; Takken, Tim

    2011-01-01

    Aim: Evidence-based recommendations regarding which exercise tests to use in children and adolescents with cerebral palsy (CP) are lacking. This makes it very difficult for therapists and researchers to choose the appropriate exercise-related outcome measures for this group. This study aimed to identify a core set of exercise tests for children…

  20. Electron beam diagnostic system using computed tomography and an annular sensor

    DOEpatents

    Elmer, John W.; Teruya, Alan T.

    2014-07-29

    A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

  1. Electron beam diagnostic system using computed tomography and an annular sensor

    DOEpatents

    Elmer, John W.; Teruya, Alan T.

    2015-08-11

    A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

  2. Pancreaticoduodenectomy for pancreas carcinoma occurring in the annular pancreas: report of a case.

    PubMed

    Kawaida, Hiromichi; Kono, Hiroshi; Watanabe, Mitsuaki; Maki, Akira; Amemiya, Hidetake; Matsuda, Masanori; Fujii, Hideki; Fukasawa, Mitsuharu; Takahashi, Ei; Sano, Katsuhiro; Inoue, Tomohiro

    2015-08-01

    The annular pancreas is a rare congenital anomaly in which a ring of the pancreas parenchyma surrounds the second part of the duodenum. Malignant tumors are extremely rare in patients with an annular pancreas. A 64-year-old man presented with appetite loss and vomiting. Abdominal contrast-enhanced computed tomography (CT) indicated pancreas parenchyma surrounding the second part of the duodenum, and a hypovascular area occupying lesion in the annular pancreas. Subtotal stomach-preserving pancreaticoduodenectomy was performed. Histopathology showed pancreatic carcinoma occurring in the complete annular pancreas.

  3. Parametric Investigations of Miniaturized Cylindrical and Annular Hall Thrusters

    SciTech Connect

    A. Smirnov; Y. Raitses; N.J. Fisch

    2001-10-16

    A cylindrical geometry Hall thruster may overcome certain physical and technological limitations in scaling down of Hall thrusters to miniature sizes. The absence of the inner wall and use of the cusp magnetic field can potentially reduce heating of the thruster parts and erosion of the channel. A 2.6 cm miniaturized Hall thruster of a flexible design was built and successfully operated in the power range of 50-300 W. Comparison of preliminary results obtained for cylindrical and annular thruster configurations is presented.

  4. Laser window with annular grooves for thermal isolation

    DOEpatents

    Warner, B.E.; Horton, J.A.; Alger, T.W.

    1983-07-13

    A laser window or other optical element which is thermally loaded, heats up and causes optical distortions because of temperature gradients between the center and the edge. A number of annular grooves, one to three or more, are formed in the element between a central portion and edge portion, producing a web portion which concentrates the thermal gradient and thermally isolates the central portion from the edge portion, producing a uniform temperature profile across the central portion and therefore reduce the optical distortions. The grooves are narrow and closely spaced with respect to the thickness of the element, and successive grooves are formed from alternate sides of the element.

  5. Annular Suspension and Pointing System (ASPS) magnetic rotary joint

    NASA Technical Reports Server (NTRS)

    Smith, W. E.; Quach, W.; Thomas, W.

    1993-01-01

    The Annular Suspension and Pointing System (ASPS) is a prototype of flight hardware for a high-accuracy space payload pointing mount. The long term project objective is to perform modifications and implement improvements to the existing ASPS in hopes of recommission. Also, new applications will be investigated for this technology. This report will focus on the first aspect of this overall goal, to establish operation of a single bearing station. Presented is an overview of the system history and bearing operation followed by the processes, results, and status of the single bearing study.

  6. Annular (HSURIA) resonators: some experimental studies including polarization effects.

    PubMed

    Chodzko, R A; Mason, S B; Turner, E B; Plummer, W W

    1980-03-01

    A repetitively pulsed CO(2) laser facility was developed for testing annular resonators. The large-aperture device exhibits generally uniform gain over an annular region of 18-cm o.d. and 10-cm i.d. The half-symmetric unstable resonator with internal axicon (HSURIA) was tested at equivalent Fresnel numbers up to 4.5. This resonator design incorporates a W-axicon mirror beam compactor that transforms a cylindricalmode region into an annular-mode region. Two HSURIA configurations were evaluated: (a) with a conical end mirror and (b) with a flat end mirror in the annular leg. With the conical end mirror, the aligned resonator produced a predominantly higher-order azimuthal mode with an on-axis null in the far field. The output was strongly linearly polarized with the electric-field vector tangential to the optic axis in both the near and far fields. The higher-order tangentially polarized mode appears to be the result of a geometric polarization scrambling effect caused by the conical end mirror. The boundary conitions for the conical or W-axicon mirrors imply that the radial electric field has a 180 degrees phase shift on reflection, whereas the tangential component is unchanged. Thus, a tangentially polarized mode is self-reproducing, but a linearly polarized mode is not. To eliminate the polarization scrambling effect in the HSURIA, the conical end mirror was replaced with a flat end mirror. The HSURIA with a flat end mirror produced a central spot in the far field that indicated an l = 0 mode with no spatial variations in polarization. Beam quality was measured in terms of the ratio n(2) of the theoretical (geometric-mode) power transmitted through an aperture of the central lobe diameter to the observed power; n(2) values as low as 1.2 were obtained. The variation of beam quality with tilt of the flat end mirror indicated a factor of 2 degradation in n(2) for a 20-microrad tilt, which is in good agreement with theory. PMID:20220932

  7. Annular self-similar solutions in ideal magnetogasdynamics

    NASA Astrophysics Data System (ADS)

    Lock, R. M.; Mestel, A. J.

    2008-08-01

    We consider the possibility of self-similar solutions describing the implosion of hollow cylindrical annuli driven by an azimuthal magnetic field, in essence a self-similar imploding liner z-pinch. We construct such solutions for gasdynamics, for ideal ‘β=0’ plasma and for ideal magnetogasdynamics (MGD). In the latter two cases some quantities are singular at the annular boundaries. Numerical solutions of the full ideal MGD initial value problem indicate that the self-similar solutions are not attractive for arbitrary initial conditions, possibly as a result of flux-freezing.

  8. Novel Annular and Subvalvular Enlargement in Congenital Mitral Valve Replacement.

    PubMed

    Carroll, Nels D; Beers, Kevin M; Maldonado, Elaine M; Calhoon, John H; Husain, S Adil

    2016-09-01

    Reparative procedures are not always feasible in congenitally abnormal mitral valves. Mechanical prosthesis has been accepted as the choice for valve replacement in the pediatric population. This report describes a case of congenital mitral valve disease requiring mitral valve replacement. The infant's mitral valve annulus was not amenable to placement of the smallest available mechanical prosthesis. The approach used here for annular and subvalvular enlargement facilitated implantation of a larger prosthesis for congenital mitral valve replacement. Five-year outcomes in a single patient may indicate broader applicability and avoidance of patient-prosthesis mismatch.

  9. Cylindrical plasmas generated by an annular beam of ultraviolet light

    SciTech Connect

    Thomas, D. M.; Allen, J. E.

    2015-07-15

    We investigate a cylindrical plasma system with ionization, by an annular beam of ultraviolet light, taking place only in the cylinder's outer region. In the steady state, both the outer and inner regions contain a plasma, with that in the inner region being uniform and field-free. At the interface between the two regions, there is an infinitesimal jump in ion density, the magnitude approaching zero in the quasi-neutral (λ{sub D} → 0) limit. The system offers the possibility of producing a uniform stationary plasma in the laboratory, hitherto obtained only with thermally produced alkali plasmas.

  10. Dynamically adjustable annular laser trapping based on axicons

    SciTech Connect

    Shao, Bing; Esener, Sadik C.; Nascimento, Jaclyn M.; Botvinick, Elliot L.; Berns, Michael W

    2006-09-01

    To study the chemotactic response of sperm to an egg and to characterize sperm motility, an annular laser trap based on axicons is designed, simulated with the ray-tracing tool, and implemented. The diameter of the trapping ring can be adjusted dynamically for a range of over 400 {mu}m by simply translating one axicon along the optical axis. Trapping experiments with microspheres and dog sperm demonstrate the feasibility of the system,and the power requirement agrees with theoretical expectation. This new type of laser trapping could provide a prototype of a parallel, objective, and quantitative tool for animal fertility and biotropism study.

  11. Electron-Hose Instability in an Annular Plasma Sheath

    SciTech Connect

    Whittum, David H.

    1999-07-08

    A relativistic electron beam propagating through an annular plasma sheath is subject to a transverse plasma-electron coupled electrostatic instability. From the linearized fluid equations, the beam-sheath interaction is resolved into three coupled equations. The corresponding wakefield is computed and the asymptotic linear evolution is noted. For illustration, numerical examples are given for a plasma accelerator employing such a sheath. While the coasting beam scalings are quite severe at low energy, single-bunch instability growth can in fact be reduced to nil, for a very high-gradient accelerator.

  12. Exhaust emissions of a double annular combustor: Parametric study

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.

    1974-01-01

    A full scale double-annular ram-induction combustor designed for Mach 3.0 cruise operation was tested. Emissions of oxides of nitrogen, carbon monoxide, unburned hydrocarbons, and smoke were measured over a range of combustor operating variables including reference velocity, inlet air temperature and pressure, and exit average temperature. ASTM Jet-A fuel was used for these tests. An equation is provided relating oxides of nitrogen emissions as a function of the combustor, operating variables. A small effect of radial fuel staging on reducing exhaust emissions (which were originally quite low) is demonstrated.

  13. Photoacoustic Imaging of Animals with an Annular Transducer Array

    NASA Astrophysics Data System (ADS)

    Yang, Di-Wu; Zhou, Zhi-Bin; Zeng, Lv-Ming; Zhou, Xin; Chen, Xing-Hui

    2014-07-01

    A photoacoustic system with an annular transducer array is presented for rapid, high-resolution photoacoustic tomography of animals. An eight-channel data acquisition system is applied to capture the photoacoustic signals by using multiplexing and the total time of data acquisition and transferring is within 3 s. A limited-view filtered back projection algorithm is used to reconstruct the photoacoustic images. Experiments are performed on a mouse head and a rabbit head and clear photoacoustic images are obtained. The experimental results demonstrate that this imaging system holds the potential for imaging the human brain.

  14. The effect of ozone depletion on the Southern Annular Mode and stratosphere-troposphere coupling

    NASA Astrophysics Data System (ADS)

    Dennison, Fraser W.; McDonald, Adrian J.; Morgenstern, Olaf

    2015-07-01

    The aim of this study is to investigate the influence of ozone depletion and recovery on the Southern Annular Mode (SAM) and stratosphere-troposphere coupling. Using the National Institute of Water and Atmospheric Research-United Kingdom Chemistry and Aerosols chemistry-climate model, we compare reference runs that include forcing due to greenhouse gases and ozone-depleting substances to sensitivity simulations in which ozone-depleting substances are fixed at their 1960 levels. We find that ozone depletion leads to an increased frequency of extreme anomalies and increased persistence of the SAM in the stratosphere as well as stronger, more persistent stratosphere-troposphere coupling. Currently, the stratosphere provides an appreciable amount of predictability to the troposphere on timescales of 1 or 2 months; however, we find that this effect reduces over time as stratospheric ozone recovers to preozone hole levels toward the latter part of this century.

  15. Laser anemometry and viscous computation of the flow through an annular turbine cascade

    NASA Astrophysics Data System (ADS)

    Spitz, Joseph D.

    1994-03-01

    An annular turbine cascade, designed for laser-Doppler velocimetry, was further modified to provide additional laser and pressure probe access. The purpose of the research was to devise laser anemometry measurement techniques in a confined annulus and improve the ability to compare numerical predictions with experimental results. Flowfield computations were completed using a viscous flow solver, with the numerical exit plane coincident with experimental measurement location. A data reduction program was written to transfer nondimensional numerical output to the experimental coordinate system for comparison of total pressure ratio, Mach number and flow angle. Endwall two-dimensional laser measurements were obtained through a 1.0922 millimeter hole to a depth of approximately three millimeters.

  16. Radiation Characterization Summary: ACRR Polyethylene-Lead-Graphite (PLG) Bucket Located in the Central Cavity on the 32-Inch Pedestal at the Core Centerline (ACRR-PLG-CC-32-cl).

    SciTech Connect

    Parma, Edward J.,; Vehar, David W.; Lippert, Lance L.; Griffin, Patrick J.; Naranjo, Gerald E.; Luker, Spencer M.

    2015-06-01

    This document presents the facility-recommended characterization of the neutron, prompt gamma-ray, and delayed gamma-ray radiation fields in the Annular Core Research Reactor (ACRR) for the polyethylene-lead-graphite (PLG) bucket in the central cavity on the 32-inch pedestal at the core centerline. The designation for this environment is ACRR-PLG-CC-32-cl. The neutron, prompt gamma-ray, and delayed gamma-ray energy spectra, uncertainties, and covariance matrices are presented as well as radial and axial neutron and gamma-ray fluence profiles within the experiment area of the bucket. Recommended constants are given to facilitate the conversion of various dosimetry readings into radiation metrics desired by experimenters. Representative pulse operations are presented with conversion examples. Acknowledgements The authors wish to thank the Annular Core Research Reactor staff and the Radiation Metrology Laboratory staff for their support of this work. Also thanks to David Ames for his assistance in running MCNP on the Sandia parallel machines.

  17. Continuum-kinetic-microscopic model of lung clearance due to core-annular fluid entrainment

    PubMed Central

    Mitran, Sorin

    2013-01-01

    The human lung is protected against aspirated infectious and toxic agents by a thin liquid layer lining the interior of the airways. This airway surface liquid is a bilayer composed of a viscoelastic mucus layer supported by a fluid film known as the periciliary liquid. The viscoelastic behavior of the mucus layer is principally due to long-chain polymers known as mucins. The airway surface liquid is cleared from the lung by ciliary transport, surface tension gradients, and airflow shear forces. This work presents a multiscale model of the effect of airflow shear forces, as exerted by tidal breathing and cough, upon clearance. The composition of the mucus layer is complex and variable in time. To avoid the restrictions imposed by adopting a viscoelastic flow model of limited validity, a multiscale computational model is introduced in which the continuum-level properties of the airway surface liquid are determined by microscopic simulation of long-chain polymers. A bridge between microscopic and continuum levels is constructed through a kinetic-level probability density function describing polymer chain configurations. The overall multiscale framework is especially suited to biological problems due to the flexibility afforded in specifying microscopic constituents, and examining the effects of various constituents upon overall mucus transport at the continuum scale. PMID:23729842

  18. Continuum-kinetic-microscopic model of lung clearance due to core-annular fluid entrainment

    NASA Astrophysics Data System (ADS)

    Mitran, Sorin

    2013-07-01

    The human lung is protected against aspirated infectious and toxic agents by a thin liquid layer lining the interior of the airways. This airway surface liquid is a bilayer composed of a viscoelastic mucus layer supported by a fluid film known as the periciliary liquid. The viscoelastic behavior of the mucus layer is principally due to long-chain polymers known as mucins. The airway surface liquid is cleared from the lung by ciliary transport, surface tension gradients, and airflow shear forces. This work presents a multiscale model of the effect of airflow shear forces, as exerted by tidal breathing and cough, upon clearance. The composition of the mucus layer is complex and variable in time. To avoid the restrictions imposed by adopting a viscoelastic flow model of limited validity, a multiscale computational model is introduced in which the continuum-level properties of the airway surface liquid are determined by microscopic simulation of long-chain polymers. A bridge between microscopic and continuum levels is constructed through a kinetic-level probability density function describing polymer chain configurations. The overall multiscale framework is especially suited to biological problems due to the flexibility afforded in specifying microscopic constituents, and examining the effects of various constituents upon overall mucus transport at the continuum scale.

  19. Composite Cores

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Spang & Company's new configuration of converter transformer cores is a composite of gapped and ungapped cores assembled together in concentric relationship. The net effect of the composite design is to combine the protection from saturation offered by the gapped core with the lower magnetizing requirement of the ungapped core. The uncut core functions under normal operating conditions and the cut core takes over during abnormal operation to prevent power surges and their potentially destructive effect on transistors. Principal customers are aerospace and defense manufacturers. Cores also have applicability in commercial products where precise power regulation is required, as in the power supplies for large mainframe computers.

  20. The Effect of Nonuniform Inlet Conditions on Annular Diffusers

    NASA Astrophysics Data System (ADS)

    Padilla, Angelina; Elkins, Chris; Eaton, John

    2010-11-01

    Most practical diffusers have complex 3D geometries and may have highly disturbed inlet flows. The performance of diffusers designed for optimum pressure recovery is governed by flow separation which can be very sensitive to inlet perturbations. We are examining the effect of upstream disturbances on the performance of practical annular diffusers. Experiments are conducted in an annular diffuser sector containing a single NACA 0015 airfoil shaped support strut. Three component, time averaged velocities are measured using magnetic resonance velocimetry and static pressure data are measured with conventional wall taps. We are testing four inlet conditions: a uniform velocity profile with thin boundary layers and relatively low turbulence intensity, a similar case with higher turbulence levels, a mean profile with uniform velocity except for a high velocity wall jet at the outer radius, and a nonuniform profile in which the mean velocity decreases with increasing radius. Generally, the results show that the diffuser acts to increase flow distortion. For the case with the radial velocity gradient, passing through the diffuser strongly increases the velocity gradient. The wall jet on the outer (diffusing) wall eliminates flow separation resulting in higher pressure recovery and thicker wall boundary layers on the other three walls. Interestingly, the separated wake of the support strut closes more rapidly for the case with the radial velocity gradient.

  1. Oscillation Characteristics of Thermocapillary Convection in An Open Annular Pool

    NASA Astrophysics Data System (ADS)

    Duan, Li; Kang, Qi; Zhang, Di

    2016-07-01

    Temperature oscillation characteristics and free surface deformation are essential phenomena in fluids with free surface. We report experimental oscillatory behaviors for hydrothermal wave instability in thermocapillary-driven flow in an open annular pool of silicone oil. The annular pool is heated from the inner cylindrical wall with the radius 4mm and cooled at the outer wall with radius 20mm, and the depth of the silicone oil layer is in the range of 0.8mm-3mm.Temperature difference between the two sidewalls was increased gradually, and the flow will become unstable via a super critical temperature difference. In the present paper we used T-type thermocouple measuring the single-point temperature inside the liquid layer and captured the tiny micrometer wave signal through a high-precision laser displacement sensor. The critical temperature difference and critical Ma number of onset of oscillation have been obtained. We discussed the critical temperature difference and critical Marangoni number varies with the change of the depth of liquid layer, and the relationship between the temperature oscillation and surface oscillation has been discussed. Experimental results show that temperature oscillation and surface oscillation start almost at the same time with similar spectrum characteristic.

  2. Coupled counterrotating polariton condensates in optically defined annular potentials.

    PubMed

    Dreismann, Alexander; Cristofolini, Peter; Balili, Ryan; Christmann, Gabriel; Pinsker, Florian; Berloff, Natasha G; Hatzopoulos, Zacharias; Savvidis, Pavlos G; Baumberg, Jeremy J

    2014-06-17

    Polariton condensates are macroscopic quantum states formed by half-matter half-light quasiparticles, thus connecting the phenomena of atomic Bose-Einstein condensation, superfluidity, and photon lasing. Here we report the spontaneous formation of such condensates in programmable potential landscapes generated by two concentric circles of light. The imposed geometry supports the emergence of annular states that extend up to 100 μm, yet are fully coherent and exhibit a spatial structure that remains stable for minutes at a time. These states exhibit a petal-like intensity distribution arising due to the interaction of two superfluids counterpropagating in the circular waveguide defined by the optical potential. In stark contrast to annular modes in conventional lasing systems, the resulting standing wave patterns exhibit only minimal overlap with the pump laser itself. We theoretically describe the system using a complex Ginzburg-Landau equation, which indicates why the condensate wants to rotate. Experimentally, we demonstrate the ability to precisely control the structure of the petal condensates both by carefully modifying the excitation geometry as well as perturbing the system on ultrafast timescales to reveal unexpected superfluid dynamics. PMID:24889642

  3. Non-null annular subaperture stitching interferometry for aspheric test

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Liu, Dong; Shi, Tu; Yang, Yongying; Chong, Shiyao; Miao, Liang; Huang, Wei; Shen, Yibing; Bai, Jian

    2015-10-01

    A non-null annular subaperture stitching interferometry (NASSI), combining the subaperture stitching idea and non-null test method, is proposed for steep aspheric testing. Compared with standard annular subaperture stitching interferometry (ASSI), a partial null lens (PNL) is employed as an alternative to the transmission sphere, to generate different aspherical wavefronts as the references. The coverage subaperture number would thus be reduced greatly for the better performance of aspherical wavefronts in matching the local slope of aspheric surfaces. Instead of various mathematical stitching algorithms, a simultaneous reverse optimizing reconstruction (SROR) method based on system modeling and ray tracing is proposed for full aperture figure error reconstruction. All the subaperture measurements are simulated simultaneously with a multi-configuration model in a ray-tracing program, including the interferometric system modeling and subaperture misalignments modeling. With the multi-configuration model, full aperture figure error would be extracted in form of Zernike polynomials from subapertures wavefront data by the SROR method. This method concurrently accomplishes subaperture retrace error and misalignment correction, requiring neither complex mathematical algorithms nor subaperture overlaps. A numerical simulation exhibits the comparison of the performance of the NASSI and standard ASSI, which demonstrates the high accuracy of the NASSI in testing steep aspheric. Experimental results of NASSI are shown to be in good agreement with that of Zygo® VerifireTM Asphere interferometer.

  4. Coupled counterrotating polariton condensates in optically defined annular potentials

    PubMed Central

    Dreismann, Alexander; Cristofolini, Peter; Balili, Ryan; Christmann, Gabriel; Pinsker, Florian; Berloff, Natasha G.; Hatzopoulos, Zacharias; Savvidis, Pavlos G.; Baumberg, Jeremy J.

    2014-01-01

    Polariton condensates are macroscopic quantum states formed by half-matter half-light quasiparticles, thus connecting the phenomena of atomic Bose–Einstein condensation, superfluidity, and photon lasing. Here we report the spontaneous formation of such condensates in programmable potential landscapes generated by two concentric circles of light. The imposed geometry supports the emergence of annular states that extend up to 100 μm, yet are fully coherent and exhibit a spatial structure that remains stable for minutes at a time. These states exhibit a petal-like intensity distribution arising due to the interaction of two superfluids counterpropagating in the circular waveguide defined by the optical potential. In stark contrast to annular modes in conventional lasing systems, the resulting standing wave patterns exhibit only minimal overlap with the pump laser itself. We theoretically describe the system using a complex Ginzburg–Landau equation, which indicates why the condensate wants to rotate. Experimentally, we demonstrate the ability to precisely control the structure of the petal condensates both by carefully modifying the excitation geometry as well as perturbing the system on ultrafast timescales to reveal unexpected superfluid dynamics. PMID:24889642

  5. The annular hematoma of the shrew yolk-sac placenta.

    PubMed

    King, B F; Enders, A C; Wimsatt, W A

    1978-05-01

    The annular hematoma of the shrew, Blarina brevicauda, is a specialized portion of the yolk-sac wall. In this study, we have examined the fine structure of the different cellular components of the anular hematoma. Small pieces of the gestation sacs from seven pregnant shrews were fixed in glutaraldehyde and osmium tetroxide and processed for transmission electron microscopy. In the area of the trophoblastic curtain, the maternal capillary endothelial cells were hypertrophied and syncytial trophoblast surrounded the capillaries. Cellular trophoblast covered part of the luminal surface of the curtain region, whereas masses of apparently degenerating syncytium were present on other areas of the surface. Maternal erythrocytes, released into the uterine lumen from the curtain region, were phagocytized and degraded by the columnar cells of the trophoblastic annulus. No evidence of iron or pigment accumulation was evident in the parietal endodermal cells underlying the annular trophoblast. Parietal endodermal cells were characterized by cuboidal shape, widely dilated intercellular spaces, and cytoplasm containing granular endoplasmic reticulum. Endodermal cells of the visceral yolk-sac accumulated large numbers of electron-dense granules as well as glycogen in their cytoplasm. Hemopoietic areas and vitelline capillaries were found subjacent to the visceral endoderm. The various portions of the yolk-sac wall of Blarina appear to perform complementary functions which are probably important in maternal-fetal iron transfer. PMID:677046

  6. Portal annular pancreas: a systematic review of a clinical challenge.

    PubMed

    Harnoss, Jonathan M; Harnoss, Julian C; Diener, Markus K; Contin, Pietro; Ulrich, Alexis B; Büchler, Markus W; Schmitz-Winnenthal, Friedrich H

    2014-10-01

    Portal annular pancreas (PAP) is an asymptomatic congenital pancreas anomaly, in which portal and/or mesenteric veins are encased by pancreas tissue. The aim of the study was to determine the role of PAP in pancreatic surgery as well as its management and potential complication, specifically, postoperative pancreatic fistula (POPF).On the basis of a case report, the MEDLINE and ISI Web of Science databases were systematically reviewed up to September 2012. All articles describing a case of PAP were considered.In summary, 21 studies with 59 cases were included. The overall prevalence of PAP was 2.4% and the patients' mean (SD) age was 55.9 (16.2) years. The POPF rate in patients with PAP (12 pancreaticoduodenectomies and 3 distal pancreatectomies) was 46.7% (in accordance with the definition of the International Study Group of Pancreatic Surgery).Portal annular pancreas is a quite unattended pancreatic variant with high prevalence and therefore still remains a clinical challenge to avoid postoperative complications. To decrease the risk for POPF, attentive preoperative diagnostics should also focus on PAP. In pancreaticoduodenectomy, a shift of the resection plane to the pancreas tail should be considered; in extensive pancreatectomy, coverage of the pancreatic remnant by the falciform ligament could be a treatment option.

  7. Annular bullous lesions with atypical erythema multiforme in leprosy.

    PubMed

    Shah, Aishani; Mahajan, Rashmi; Ninama, Kishan; Bilimoria, Freny

    2014-09-01

    Erythema nodosum leprosum (ENL) is an immune complex-mediated reaction that may complicate the course of multibacillary leprosy. Bullous lesions in Type II reaction, though reported, are exceedingly rare. We report the case of a 32 year old female patient who presented initially at our OPD with erythema nodosum. Cutaneous examination revealed impaired sensation over dorsum of right foot and thickened right lateral popliteal nerve. Slit skin smear (SSS) from ear lobes revealed AFB with a bacteriological index of 2+. She was started on MDT, tablet ofloxacin 200 mg twice a day, and 30 mg oral prednisolone. Two months later, she presented with generalised pruritus, large target lesions over the back, and hemorrhagic bullae over lower extremities and annular pattern of bullae, over both arms. A SSS was repeated which was positive for AFB. Histopathology from bullous lesions was consistent with ENL. Direct Immunofluorescence (DIF) study was negative. Our patient improved rapidly after she was started on thalidomide 100 mg twice daily, with withdrawal of ofloxacin. Erythema Multiforme (EMF) and annular bullous lesions have been reported in patients on treatment with ofloxacin. This case is being presented due to the unusual and varied manifestation of Type II lepra reaction in a 34 year old female patient. PMID:25509721

  8. Annular beam-driven high-gradient accelerators

    SciTech Connect

    Keinigs, R.; Jones, M.E.

    1988-01-01

    During the past several years there has been an increasing interest in using wakefield acceleration techniques as a means for achieving TeV energies with the next generation of linear colliders. The principal design goals for a wakefield accelerator that is to be sued in this context are high accelerating gradients and large transformer ratios. Fundamentally any slow wave structure can function as a wakefield accelerator, and several interesting concepts have been proposed. In this paper we consider for the slow wave structure a dielectrically loaded waveguide. The Dielectric Wakefield Accelerator is a very simple device. The geometry consists of a gapless cavity filled with a dielectric. The dielectric may fill all or just part of the cavity. Here we investigate driving the system with an intense annular beam, so the dielectric is separated from the wall by a vacuum region in which this beam is propagated. The primary advantage of driving with an annular beam is that larger currents can be achieved, and thus larger accelerating gradients can be generated. The drive beam is stabilized by a strong, axial magnetic field. The wall is coated with a dielectric liner to provide for better coupling. A small hole is drilled in the center of the dielectric to allow for the passage of a low current, witness beam.

  9. A Compact Annular Ring Microstrip Antenna for WSN Applications

    PubMed Central

    Wang, Daihua; Song, Linli; Zhou, Hanchang; Zhang, Zhijie

    2012-01-01

    A compact annular ring microstrip antenna was proposed for a wireless sensor network (WSN) application in the 2.4 GHz band. In this paper the major considerations of the conformal antenna design were the compact size and the impact on antenna's performance of a steel installation base. By using a chip resistor of large resistance (120 Ω) the antenna size was reduced to 38% of that a conventional annular ring patch antenna. With the addition of the steel installation base the resonant frequency of the antenna increases about 4.2% and the bandwidth reduces from 17.5% to 11.7% by adjusting the load resistance simultaneously. Several key parameters were discussed and optimized, and the antenna was fabricated and its performance measured. The antenna is well matched at 2.4 GHz with 34.2 dB return loss and –2.5 dBi peak gain. Meanwhile, it exhibits excellent radiation patterns with very low cross-polarization levels. PMID:23012510

  10. A compact annular ring microstrip antenna for WSN applications.

    PubMed

    Wang, Daihua; Song, Linli; Zhou, Hanchang; Zhang, Zhijie

    2012-01-01

    A compact annular ring microstrip antenna was proposed for a wireless sensor network (WSN) application in the 2.4 GHz band. In this paper the major considerations of the conformal antenna design were the compact size and the impact on antenna's performance of a steel installation base. By using a chip resistor of large resistance (120 Ω) the antenna size was reduced to 38% of that a conventional annular ring patch antenna. With the addition of the steel installation base the resonant frequency of the antenna increases about 4.2% and the bandwidth reduces from 17.5% to 11.7% by adjusting the load resistance simultaneously. Several key parameters were discussed and optimized, and the antenna was fabricated and its performance measured. The antenna is well matched at 2.4 GHz with 34.2 dB return loss and -2.5 dBi peak gain. Meanwhile, it exhibits excellent radiation patterns with very low cross-polarization levels.

  11. Design Attributes and Scale Up Testing of Annular Centrifugal Contactors

    SciTech Connect

    David H. Meikrantz; Jack D. Law

    2005-04-01

    Annular centrifugal contactors are being used for rapid yet efficient liquid- liquid processing in numerous industrial and government applications. Commercialization of this technology began eleven years ago and now units with throughputs ranging from 0.25 to 700 liters per minute are readily available. Separation, washing, and extraction processes all benefit from the use of this relatively new commercial tool. Processing advantages of this technology include: low in-process volume per stage, rapid mixing and separation in a single unit, connection-in-series for multi-stage use, and a wide operating range of input flow rates and phase ratios without adjustment. Recent design enhancements have been added to simplify maintenance, improve inspection ability, and provide increased reliability. Cartridge-style bearing and mechanical rotary seal assemblies that can include liquid-leak sensors are employed to enhance remote operations, minimize maintenance downtime, prevent equipment damage, and extend service life. Clean-in-place capability eliminates the need for disassembly, facilitates the use of contactors for feed clarification, and can be automated for continuous operation. In nuclear fuel cycle studies, aqueous based separations are being developed that efficiently partition uranium, actinides, and fission products via liquid-liquid solvent extraction. Thus, annular centrifugal contactors are destined to play a significant role in the design of such new processes. Laboratory scale studies using mini-contactors have demonstrated feasibility for many such separation processes but validation at an engineering scale is needed to support actual process design.

  12. A compact annular ring microstrip antenna for WSN applications.

    PubMed

    Wang, Daihua; Song, Linli; Zhou, Hanchang; Zhang, Zhijie

    2012-01-01

    A compact annular ring microstrip antenna was proposed for a wireless sensor network (WSN) application in the 2.4 GHz band. In this paper the major considerations of the conformal antenna design were the compact size and the impact on antenna's performance of a steel installation base. By using a chip resistor of large resistance (120 Ω) the antenna size was reduced to 38% of that a conventional annular ring patch antenna. With the addition of the steel installation base the resonant frequency of the antenna increases about 4.2% and the bandwidth reduces from 17.5% to 11.7% by adjusting the load resistance simultaneously. Several key parameters were discussed and optimized, and the antenna was fabricated and its performance measured. The antenna is well matched at 2.4 GHz with 34.2 dB return loss and -2.5 dBi peak gain. Meanwhile, it exhibits excellent radiation patterns with very low cross-polarization levels. PMID:23012510

  13. The Growth of Instabilities in Annular Liquid Sheets

    SciTech Connect

    Duke, Daniel J.; Honnery, Damon R; Soria, Julio

    2015-11-01

    An annular liquid sheet surrounded by parallel co-flowing gas is an effective atomiser. However, the initial instabilities which determine the primary break-up of the liquid sheet are not well understood. Lack of agreement on the influence of the boundary conditions and the non-dimension scaling of the initial instability persists between theoretical stability analyses and experiments. To address this matter, we have undertaken an experimental parametric study of an aerodynamically-driven, non-swirling annular water sheet. The effects of sheet thickness, inner and outer gas-liquid momentum ratio were investigated over an order of magnitude variation in Reynolds and Weber number. From high-speed image correlation measurements in the near-nozzle region, we propose new empirical correlations for the frequency of the instability as a function of the total gas-liquid momentum ratio, with good non-dimensional collapse. From analysis of the instability velocity probability densities, we find two persistent and distinct superimposed instabilities with different growth rates. The first is a short-lived, rapidly saturating sawtooth-like instability. The second is a slower-growing stochastic instability which persists through the break-up of the sheet. The presence of multiple instabilities whose growth rates do not strongly correlate with the shear velocities may explain some of the discrepancies between experiments and stability analyses.

  14. Biglycan and fibromodulin fragmentation correlates with temporal and spatial annular remodelling in experimentally injured ovine intervertebral discs

    PubMed Central

    Smith, Susan M.; Fuller, Emily S.; Young, Allan A.; Roughley, Peter J.; Dart, Andrew; Little, Christopher B.

    2007-01-01

    This study evaluated spatial and temporal extracellular matrix changes, induced by controlled surgical defects in the outer third of the annulus fibrosus (AF) of ovine intervertebral discs (IVDs). Thirty-two 4 year old sheep received a 4 mm deep × 10 mm wide standard annular surgical incision in the L1L2 and L3L4 IVDs (lesion group), 32 sheep were also subjected to the same surgical approach but the AF was not incised (sham-operated controls). Remodeling of the IVD matrix in the lesion and sham discs was assessed histochemically at 3, 6,12 and 26 month post operation (PO). Discs were also dissected into annular lesion site and contra-lateral AF and NP and equivalent zones in the sham sheep group, extracted with GuHCl, dialysed, freeze dried, digested with chondroitinase ABC/keratanase-I and aliquots examined for small leucine repeat proteoglycan (SLRP) core protein species by Western blotting using C-terminal antibodies to decorin, biglycan, lumican and fibromodulin and monoclonal antibody (Mab) 2B6 to unsaturated stub epitopes on chondroitin-4-sulphate generated by chondroitinase ABC. Masson Trichrome and Picrosirius red staining demonstrated re-organisation of the outermost collagenous lamellae in the incised discs 3–6 month PO. Toluidine blue staining also demonstrated a focal loss of anionic proteoglycan (PG) from the annular lesion 3–6 month PO with partial recovery of PG levels by 26 month. Specific fragments of biglycan and fibromodulin were associated with remodeling of the AF 12–26 month PO in the lesion IVDs but were absent from the NP of the lesion discs or all tissue zones in the sham animal group. Fragments of decorin were also observed in lesion zone extracts from 3 to 6 months but diminished after this. Isolation and characterization of the biglycan/fibromodulin fragments may identify them as prospective biomarkers of annular remodeling and characterization of the enzyme systems responsible for their generation may identify

  15. Analytical model of an Annular Momentum Control Device (AMCD) laboratory test model magnetic bearing actuator

    NASA Technical Reports Server (NTRS)

    Groom, N. J.

    1979-01-01

    An analytical model of an Annular Momentum Control Device (AMCD) laboratory test model magnetic bearing actuator with permanent magnet fluxbiasing is presented. An AMCD consists of a spinning annular rim which is suspended by a noncontacting linear electromagnetic spin motor. The actuator is treated as a lumped-parameter electromechanical system in the development of the model.

  16. Subcutaneous granuloma annulare of the scalp in childhood: a case report and review of the literature.

    PubMed

    Sabuncuoğlu, Hakan; Oge, Kamil; Söylemezoğlu, Figen; Sağlam, Arzu

    2007-01-01

    Granuloma annulare is a benign inflammatory skin lesion of unknown etiology that is usually seen in adults and children and subtypes of it includes localized granuloma annulare, generalized granuloma annulare, subcutaneous granuloma annulare and arcuate dermal erythema. Etiology and pathogenesis of granuloma annulare are obscure, although there is much evidence for an immunologic mechanism. Precipitating factors are insect bites, sunburn, photochemotherapy, drugs, physical trauma, acute phlebitis and sepsis after surgery. Some investigators were suggested a relationship of granuloma annulare to a latent or clinically manifest diabetes or rheumatoid arthritis. In contrast, an association of subcutaneous granuloma annulare with these diseases in childhood has not been reported in the literature. Subcutaneous granuloma annulare of the scalp is rare lesion in childhood and nodules on the scalp are usually non-, or slightly mobile, whereas lesions on the extremities are freely mobile. For definitive diagnosis, a biopsy should be performed but wide surgical intervention or medical treatment is not indicated. In case of recurrence, no additional diagnostic studies are necessary. PMID:17918673

  17. Erythema annulare centrifugum as presenting sign of activation of breast cancer*

    PubMed Central

    Topal, Ilteris Oguz; Topal, Yunus; Sargan, Aytul; Duman, Hatice; Gungor, Sule; Goncu, Ozgur Emek Kocaturk; Ozekinci, Selver

    2015-01-01

    Erythema annulare centrifugum is a figurate erythema of unknown etiology. It has been associated with many different entities, including infections, food allergy, drug reactions and malignant neoplasms. Herein, we report a case of erythema annulare centrifugum as presenting sign of activation of breastcancer. PMID:26734884

  18. Erythema annulare centrifugum as presenting sign of activation of breast cancer.

    PubMed

    Topal, Ilteris Oguz; Topal, Yunus; Sargan, Aytul; Duman, Hatice; Gungor, Sule; Goncu, Ozgur Emek Kocaturk; Ozekinci, Selver

    2015-01-01

    Erythema annulare centrifugum is a figurate erythema of unknown etiology. It has been associated with many different entities, including infections, food allergy, drug reactions and malignant neoplasms. Herein, we report a case of erythema annulare centrifugum as presenting sign of activation of breastcancer.

  19. Entrance and exit region friction factor models for annular seal analysis. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Elrod, David Alan

    1988-01-01

    The Mach number definition and boundary conditions in Nelson's nominally-centered, annular gas seal analysis are revised. A method is described for determining the wall shear stress characteristics of an annular gas seal experimentally. Two friction factor models are developed for annular seal analysis; one model is based on flat-plate flow theory; the other uses empirical entrance and exit region friction factors. The friction factor predictions of the models are compared to experimental results. Each friction model is used in an annular gas seal analysis. The seal characteristics predicted by the two seal analyses are compared to experimental results and to the predictions of Nelson's analysis. The comparisons are for smooth-rotor seals with smooth and honeycomb stators. The comparisons show that the analysis which uses empirical entrance and exit region shear stress models predicts the static and stability characteristics of annular gas seals better than the other analyses. The analyses predict direct stiffness poorly.

  20. Enhanced simulation software for rocket turbopump, turbulent, annular liquid seals

    NASA Technical Reports Server (NTRS)

    Padavala, Satya; Palazzolo, Alan

    1994-01-01

    One of the main objectives of this work is to develop a new dynamic analysis for liquid annular seals with arbitrary profile and to analyze a general distorted interstage seal of the space shuttle main engine high pressure oxygen turbopump (SSME-ATD-HPOTP). The dynamic analysis developed is based on a method originally proposed by Nelson and Nguyen. A simpler scheme based on cubic splines is found to be computationally more efficient and has better convergence properties at higher eccentricities. The first order solution of the original analysis is modified by including a more exact solution that takes into account the variation of perturbed variables along the circumference. A new set of equations for dynamic analysis are derived based on this more general model. A unified solution procedure that is valid for both Moody's and Hirs' friction models is presented. Dynamic analysis is developed for three different models: constant properties, variable properties, and thermal effects with variable properties. Arbitrarily varying seal profiles in both axial and circumferential directions are considered. An example case of an elliptical seal with varying degrees of axial curvature is analyzed in detail. A case study based on predicted clearances of an interstage seal of the SSME-ATD-HPOTP is presented. Dynamic coefficients based on external specified load are introduced to analyze seals that support a preload. The other objective of this work is to study the effect of large rotor displacements of SSME-ATD-HPOTP on the dynamics of the annular seal and the resulting transient motion. One task is to identify the magnitude of motion of the rotor about the centered position and establish limits of effectiveness of using current linear models. This task is accomplished by solving the bulk flow model seal governing equations directly for transient seal forces for any given type of motion, including motion with large eccentricities. Based on the above study, an equivalence is

  1. Theory of low voltage annular beam free-electron lasers

    SciTech Connect

    Blank, M.; Freund, H.P.; Jackson, R.H.

    1995-12-31

    An nonlinear analysis of an annular beam propagating through a cylindrical waveguide in the presence of a helical wiggler and an axial guide field is presented. The analysis is based upon the ARACHNE simulation which is a non-wiggler-averaged slow-time-scale simulation code in which the electromagnetic field is represented as a superposition of the TE and TM modes in a vacuum waveguide, and the beam space-charge waves are represented as a superposition of Gould-Trivelpiece modes. The DC self-electric and self-magnetic fields are also included in the model. ARACHNE has been extensively benchmarked against experiments at MIT and NRL in the past with good agreement, but all of these experiments have dealt with solid electron beams and beam voltages in excess of 200 kV. In seeking to reduce the beam voltage requirements we now consider the effect of operation with an annular beam. One advantage to be obtained by using an annular beam is that, for a fixed beam current, the effect of the DC selffields (i.e., the space-charge depression in beam voltage) will be reduced relative to that of a solid beam. This facilitates beam transport in short period wigglers in which the transverse dimensions are also small. A specific example is under study which makes use of 55 kV/5A electron beam with inner and outer radii of 0.27 cm and 0.33 cm respectively. The wiggler amplitude is 250 G with a period of 0.9 cm. and guide fields up to 3 kG corresponding to Group I trajectories. The waveguide radius is chosen to correspond to grazing incidence for the fundamental mode in Ku-Band (12-18 GHz). Preliminary results indicate that efficiencies upwards of 10% are possible with no wiggler taper. In addition, the energy spread must be held below 0.1%, and the instantaneous bandwidth is found to be greater than 20%.

  2. Development of an internally cooled annular fuel bundle for pressurized heavy water reactors

    SciTech Connect

    Hamilton, H.; Armstrong, J.; Kittmer, A.; Zhuchkova, A.; Xu, R.; Hyland, B.; King, M.; Nava-Dominguez, A.; Livingstone, S.; Bergeron, A.

    2013-07-01

    A number of preliminary studies have been conducted at Atomic Energy of Canada Limited to explore the potential of using internally cooled annular fuel (ICAF) in CANDU reactors including finite element thermo-mechanical modelling, reactor physics, thermal hydraulics, fabrication and mechanical design. The most compelling argument for this design compared to the conventional solid-rod design is the significant reduction in maximum fuel temperature for equivalent LERs (linear element ratings). This feature presents the potential for power up-rating or higher burnup and a decreased defect probability due to in-core power increases. The thermal-mechanical evaluation confirmed the significant reduction in maximum fuel temperatures for ICAF fuel compared to solid-rod fuel for equivalent LER. The maximum fuel temperature increase as a function of LER increase is also significantly less for ICAF fuel. As a result, the sheath stress induced by an equivalent power increase is approximately six times less for ICAF fuel than solid-rod fuel. This suggests that the power-increase thresholds to failure (due to stress-corrosion cracking) for ICAF fuel should be well above those for solid-rod fuel, providing improvement in operation flexibility and safety.

  3. Physical understanding of gas-liquid annular flow and its transition to dispersed droplets

    NASA Astrophysics Data System (ADS)

    Kumar, Parmod; Das, Arup Kumar; Mitra, Sushanta K.

    2016-07-01

    Transformation from annular to droplet flow is investigated for co-current, upward gas-liquid flow through a cylindrical tube using grid based volume of fluid framework. Three transitional routes, namely, orificing, rolling, and undercutting are observed for flow transformation at different range of relative velocities between the fluids. Physics behind these three exclusive phenomena is described using circulation patterns of gaseous phase in the vicinity of a liquid film which subsequently sheds drop leading towards transition. Orifice amplitude is found to grow exponentially towards the core whereas it propagates in axial direction in a parabolic path. Efforts have been made to fit the sinusoidal profile of wave structure with the numerical interface contour at early stages of orificing. Domination of gas inertia over liquid flow has been studied in detail at the later stages to understand the asymmetric shape of orifice, leading towards lamella formation and droplet generation. Away from comparative velocities, circulations in the dominant phase dislodge the drop by forming either a ligament (rolling) or a bag (undercut) like protrusion in liquid. Study of velocity patterns in the plane of droplet dislodge reveals the underlying physics behind the disintegration and its dynamics at the later stages. Using numerical phase distributions, rejoining of dislodged droplet with liquid film as post-rolling consequences has been also proposed. A flow pattern map showing the transitional boundaries based on the physical mechanism is constructed for air-water combination.

  4. Ice Core Investigations

    ERIC Educational Resources Information Center

    Krim, Jessica; Brody, Michael

    2008-01-01

    What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice Core Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice core drilling, and air…

  5. Culture as the Core: Perspectives on Culture in Second Language Learning. A Volume in Research in Second Language Learning.

    ERIC Educational Resources Information Center

    Lange, Dale, Ed.; Paige, R. Michael, Ed.

    This collection of papers includes 12 chapters in two parts. Part 1 "Culture as the Core: Interdisciplinary Perspectives on Culture Teaching and Learning in the Second Language Curriculum," includes: (1) "Extending Communicative Concepts in the Second Language Curriculum: A Sociolinguistic Perspective" (Muriel Saville-Troike); (2) "Teaching along…

  6. Examination of Potential Management Decisions Based upon a Core Collection Derived from Last Circulation Date Data. Research Report No. 1.

    ERIC Educational Resources Information Center

    Schwarz, Philip; Olson, Linda

    This study was conducted to fulfill two objectives: to gather the data necessary to define the core collection, i.e., a subset of the holdings that can be identified with reasonable assurance as being able to fulfill a certain predetermined percentage of the future demand on the present collection, and to examine the value of these data as a…

  7. An Examination of Intervention Research with Secondary Students with EBD in Light of Common Core State Standards for Mathematics

    ERIC Educational Resources Information Center

    Mulcahy, Candace A.; Maccini, Paula; Wright, Kenneth; Miller, Jason

    2014-01-01

    In this review, the authors offer a critical analysis of published interventions for improving mathematics performance among middle and high school students with EBD in light of the Common Core State Standards. An exhaustive review of literature from 1975 to December 2012 yielded 20 articles that met criteria for inclusion. The authors analyzed…

  8. Core Journal Networks and Cocitation Maps in the Marine Sciences: Tools for Information Management in Interdisciplinary Research.

    ERIC Educational Resources Information Center

    McCain, Katherine W.

    1992-01-01

    Demonstrates the interrelationship between two traditionally separate literatures, i.e., marine biology and physical oceanography, and develops a joint core journal list. The use of journal intercitation data from "Journal Citation Reports" for "Science Citation Index" and from SCISEARCH on DIALOG to create a cocitation map is described. (15…

  9. Vortex signatures in annular Bose-Einstein condensates

    SciTech Connect

    Cozzini, M.; Stringari, S.; Jackson, B.

    2006-01-15

    We consider a Bose-Einstein condensate confined in a 'Mexican hat' or sombrero potential, with a quartic minus quadratic radial dependence. We find conditions under which the ground state is annular in shape, with a hole in the center of the condensate. Rotation leads to the appearance of stable multiply quantized vortices, giving rise to a superfluid flow around the ring. The collective modes of the system are explored both numerically and analytically using the Gross-Pitaevskii and hydrodynamic equations. Potential experimental schemes to detect vorticity are proposed and evaluated, which include measuring the splitting of collective-mode frequencies, observing expansion following release from the trap, and probing the momentum distribution of the condensate.

  10. Digital controller design: Analysis of the annular suspension pointing system

    NASA Technical Reports Server (NTRS)

    Kuo, B. C.

    1979-01-01

    The Annular Suspension and Pointing System (ASPS) is a payload auxiliary pointing device of the Space Shuttle. The ASPS is comprised of two major subassemblies, a vernier and a coarse pointing subsystem. The experiment is attached to a mounting plate/rim combination which is suspended on magnetic bearing/actuators (MBA) strategically located about the rim. Fine pointing is achieved by gimballing the plate/rim within the MBA gaps. Control about the experiment line-of-sight is obtained through the use of a non-contacting rim drive and positioning torquer. All sensors used to close the servo loops on the vernier system are noncontacting elements. Therefore, the experiment is a free-flyer constrained only by the magnetic forces generated by the control loops.

  11. Investigation of a low NOx full-scale annular combustor

    NASA Technical Reports Server (NTRS)

    1982-01-01

    An atmospheric test program was conducted to evaluate a low NOx annular combustor concept suitable for a supersonic, high-altitude aircraft application. The lean premixed combustor, known as the vortex air blast (VAB) concept, was tested as a 22.0-cm diameter model in the early development phases to arrive at basic design and performance criteria. Final demonstration testing was carried out on a full scale combustor of 0.66-m diameter. Variable geometry dilution ports were incorporated to allow operation of the combustor across the range of conditions between idle (T(in) = 422 K, T(out) = 917 K) and cruise (T(in) = 833 K, T(out) - 1778 K). Test results show that the design could meet the program NOx goal of 1.0 g NO2/kg fuel at a one-atmospheric simulated cruise condition.

  12. Fuel Injector Design Optimization for an Annular Scramjet Geometry

    NASA Astrophysics Data System (ADS)

    Steffen, Christopher J., Jr.

    2003-01-01

    A four-parameter, three-level, central composite experiment design has been used to optimize the configuration of an annular scramjet injector geometry using computational fluid dynamics. The computational fluid dynamic solutions played the role of computer experiments, and response surface methodology was used to capture the simulation results for mixing efficiency and total pressure recovery within the scramjet flowpath. An optimization procedure, based upon the response surface results of mixing efficiency, was used to compare the optimal design configuration against the target efficiency value of 92.5%. The results of three different optimization procedures are presented and all point to the need to look outside the current design space for different injector geometries that can meet or exceed the stated mixing efficiency target.

  13. Fluxons in long and annular intrinsic Josephson junction stacks

    NASA Astrophysics Data System (ADS)

    Clauss, T.; Oehmichen, V.; Mößle, M.; Müller, A.; Weber, A.; Koelle, D.; Kleiner, R.

    2002-12-01

    A promising approach towards a THz oscillator based on intrinsic Josephson junctions in high-temperature superconductors is based on the collective motion of Josephson fluxons, which are predicted to form various configurations ranging from a triangular to a quadratic lattice. Not only for this reason, but certainly also for the sake of basic physics, several experimental and theoretical investigations have been done on the subject of collective fluxon dynamics in stacked intrinsic Josephson junctions. In this paper we will present some experimental results on the fluxon dynamics of long intrinsic Josephson junction stacks made of Bi2Sr2CaCu2O8. The stacks were formed either in an open or in an annular geometry, and clear resonant fluxon modes were observed. Experiments discussed include measurements of current-voltage characteristics in external magnetic fields and in external microwave fields.

  14. Intermittent Flow of Granular Matter in an Annular Geometry

    NASA Astrophysics Data System (ADS)

    Brzinski, Ted; Daniels, Karen E.

    Granular solids can be subjected to a finite stress below which the response is elastic. Above this yield stress, however, the material fails catastrophically, undergoing a rapid plastic deformation. In the case of a monotonically increasing stress the material exhibits a characteristic stick-slip response. We investigate the statistics of this intermittent failure in an annular shear geometry, driven with a linear-ramp torque in order to generate the stick-slip behavior. The apparatus is designed to allow visual access to particle trajectories and inter-particle forces (through the use of photoelastic materials). Additionally, twelve piezoelectric sensors at the outer wall measure acoustic emissions due to the plastic deformation of the material. We vary volume fraction, and use both fixed and deformable boundaries. We measure how the distribution of slip size and duration are related to the bulk properties of the packing, and compare to systems with similar governing statistics.

  15. Annular dark field transmission electron microscopy for protein structure determination.

    PubMed

    Koeck, Philip J B

    2016-02-01

    Recently annular dark field (ADF) transmission electron microscopy (TEM) has been advocated as a means of recording images of biological specimens with better signal to noise ratio (SNR) than regular bright field images. I investigate whether and how such images could be used to determine the three-dimensional structure of proteins given that an ADF aperture with a suitable pass-band can be manufactured and used in practice. I develop an approximate theory of ADF-TEM image formation for weak amplitude and phase objects and test this theory using computer simulations. I also test whether these simulated images can be used to calculate a three-dimensional model of the protein using standard software and discuss problems and possible ways to overcome these. PMID:26656466

  16. Vortex shedding from struts in an annular exhaust diffuser

    SciTech Connect

    Fric, T.F.; Villarreal, R.; Auer, R.O.; James, M.L.; Ozgur, D.; Staley, T.K.

    1998-01-01

    Results from scale-model experiments and industrial gas turbine tests show that strut vortex shedding in an annular exhaust diffuser can effectively be modified by adding tapered chord to the struts. The struts are bluff bodies at full-speed, no-load conditions, when inlet swirl is close to 60 deg. Data from wind tunnel tests show that wake Strouhal number is 0.47, larger than that expected for an isolated cylinder wake. This value of Strouhal number agrees with those measured in full-scale exhaust diffusers. Wind tunnel tests showed that a strut with tapered chord most effectively reduced wake amplitudes and shifted shedding frequency. The tapered strut was also effective in reducing shedding amplitude in a scale-model diffuser. Finally, gas turbine tests employing a tapered strut showed significant reductions in unsteady pressure and noise. A major benefit of strut taper is a reduction of noise by uncoupling of vortex shedding from acoustic resonant response.

  17. Reduction of asymmetry transport in the annular Penning trap

    NASA Astrophysics Data System (ADS)

    Robertson, Scott; Sternovsky, Zoltan; Walch, Bob

    2004-05-01

    In the Penning trap, there is transport of electrons in the limit of zero gas pressure that arises from asymmetric stray electric fields. In an annular version of the Penning trap, this asymmetry transport is shown to be greatly reduced when the plasma-facing surfaces are coated with colloidal graphite. In a separate device, an emissive probe is used to examine the space potential a few millimeters above coated and uncoated surfaces. It is found that the rms potential variation is approximately 250 mV for uncoated surfaces and 15 mV for coated surfaces. The characteristic length scale of the inhomogeneities is ˜1 cm. Glow-discharge cleaning, which is easily renewed, is shown to reduce the potential variation to the same level that is obtained with the colloidal graphite coating.

  18. Simulation study with arbitrary profile liquid annular seals

    SciTech Connect

    Padavala, S.; Palazzolo, A.B.

    1994-10-01

    This paper presents an improved dynamic analysis for liquid annular seals with arbitrary profile based on a method first proposed by Nelson and Nguyen. An improved first-order solution that incorporates a continuous interpolation of perturbed quantities in the circumferential direction is presented. The original method uses an approximation scheme for circumferential gradients of zeroth order solution based on Fast Fourier Transforms (FFT). A simpler scheme based on cubic splines is found to be computationally more efficient, with better convergence at higher eccentricities. Arbitrarily varying seal profiles in both axial and circumferential directions are considered. A procedure for computing dynamic coefficients based on external specific load is discussed. An example case of an elliptical seal with varying degrees of axial curvature is analyzed. A case study based on actual operating clearances (6 axial planes with 68 clearances/plane) of an interstage seal of the Space Shuttle Main Engine High Pressure Oxygen Turbopump (SSME-ATD-HPOTP) is presented.

  19. Two-phase flow instabilities in a vertical annular channel

    SciTech Connect

    Babelli, I.; Nair, S.; Ishii, M.

    1995-09-01

    An experimental test facility was built to study two-phase flow instabilities in vertical annular channel with emphasis on downward flow under low pressure and low flow conditions. The specific geometry of the test section is similar to the fuel-target sub-channel of the Savannah River Site (SRS) Mark 22 fuel assembly. Critical Heat Flux (CHF) was observed following flow excursion and flow reversal in the test section. Density wave instability was not recorded in this series of experimental runs. The results of this experimental study show that flow excursion is the dominant instability mode under low flow, low pressure, and down flow conditions. The onset of instability data are plotted on the subcooling-Zuber (phase change) numbers stability plane.

  20. Interfacial shear modeling in two-phase annular flow

    SciTech Connect

    Kumar, R.; Edwards, D.P.

    1996-07-01

    A new interfacial shear stress model called the law of the interface model, based on the law of the wall approach in turbulent flows, has been developed and locally applied in a fully developed, adiabatic, two-phase annular flow in a duct. Numerical results have been obtained using this model in conjunction with other models available in the literature that are required for the closure of the continuity and momentum equations. These results have been compared with droplet velocity data (using laser Doppler velocimetry and hot film anemometry), void fraction data (using gamma densitometry) and pressure drop data obtained in a R-134A refrigerant test facility. Droplet velocity results match the experimental data well, however, the prediction of the void fraction is less accurate. The poor prediction of void fraction, especially for the low void fraction cases, appears to be due to the lack of a good mechanistic model for entrainment.

  1. Interfacial shear modeling in two-phase annular flow

    SciTech Connect

    Kumar, R.; Edwards, D.P.

    1996-11-01

    A new interfacial shear stress model called the law of the interface model, based on the law of the wall approach in turbulent flows, has been developed and locally applied in a fully developed, adiabatic, two-phase annular flow in a duct. Numerical results have been obtained using this model in conjunction with other models available in the literature that are required for the closure of the continuity and momentum equations. These results have been compared with droplet velocity data (using laser Doppler velocimetry and hot film anemometry), void fraction data (using gamma densitometry) and pressure drop data obtained in a R-134A refrigerant test facility. Droplet velocity results match the experimental data well, however, the prediction of the void fraction is less accurate. The poor prediction of void fraction, especially for the low void fraction cases, appears to be due to the lack of a good mechanistic model for entrainment.

  2. Hyperthermia and inhomogeneous tissue effects using an Annular Phased Array

    SciTech Connect

    Turner, P.F.

    1984-08-01

    A regional hyperthermia Annular Phased Array (APA) applicator is described, and examples of its various heating patterns, obtained by scanning the electric fields with a small E-field sensor, are illustrated. Also shown are the effects of different frequencies of an elliptical phantom cylinder having a 1-cm-thick artificial fat wall and the general dimensions of the human trunk. These studies show the APA's ability to achieve uniform heating at lower frequencies (below 70 MHz) or to focus central heating at moderately higher frequencies (above 70 MHz). The influence of human anatomical contours in altering heating patterns is discussed using results obtained with a female mannequin having a thin latex shell filled with tissue-equivalent phantom. Field perturbations caused by internally embedded low-dielectric structures are presented, showing the localized effects of small objects whose surfaces are perpendicular to the electric field.

  3. Buoyancy Driven Flow in an Axisymmetric Spherical Annular Sector

    NASA Astrophysics Data System (ADS)

    Thamire, Chandrasekhar; Wright, Neil T.; von Kerczek, Christian H.

    1996-11-01

    Results from analysis of axisymmetric, laminar buoyancy driven flows in a spherical annular sector with its outer radius equal to 1.5 times the inner radius and a sector angle of .75π are presented. The spherical surfaces of the enclosure are assumed to be heated and cooled isothermally, the radial surface being insulated. A time marching finite differencing scheme is used to solve the governing equations. The effects of Grashof number Gr and Prandtl number Pr on convective motion and heat transfer are examined. Flow patterns, changing from unicellular to multicellular flows with increasing Gr, and heat transfer results are graphically illustrated. Interesting recirculation zones develop at the insulated boundary for Gr = 10^5. The heat transfer calculations indicate that the Nusselt number depends strongly on Gr, and weakly on Pr in the range of parameters studied.

  4. Study of spiral flow generated through an annular slit

    NASA Astrophysics Data System (ADS)

    Kim, Tae Hun; Matsuo, Shigeru; Setoguchi, Toshiaki; Kim, Heuy-Dong

    2005-06-01

    The effect of pressurized air inlets in the reservoir upstream of the annular slit on characteristics of the axial and tangential velocity components is investigated numerically, and the mechanism of occurrence of spiral nozzle flow is clarified. In simulations, Unified Platform for Aerospace Computational Simulation (UPACS) is used. The governing equations under consideration are the unsteady compressible Navier - Stokes. A second-order finite volume scheme with MUSCL (Roe scheme) is used to discretize the spatial derivatives, and a second order-central difference scheme for the viscous terms, and a MFGS (Matrix Free Gauss Seidel) is employed for time integration. Spalart-Allmaras model was used as a turbulence model. The results obtained are compared with velocity distributions in the experiment measured by the two-component fiber optic laser Doppler velocimeter system. The existence of discrete pressurized air inlets that leads to the occurrence of asymmetrical characteristics is a very important factor for the formation of spiral flow.

  5. Thermo-electrohydrodynamic internal waves in annular geometry

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Harunori; Meyer, Antoine; Crumeyrolle, Olivier; Mutabazi, Innocent

    2014-11-01

    An electric field applied to a dielectric fluid with a temperature gradient generates a body force on the fluid, which can be regarded as thermal buoyancy associated with an electric effective gravity. We consider the internal waves due to this thermoelectric force in annular geometry, where the force field is centro-symmetric. The Earth's gravity is neglected. This configuration is of relevance to large-scale geophysical flows. The dispersion relation of the waves is determined by a spectral method, with or without taking into account the fluid viscosity. The effects of geometry curvature and of a thermoelectric feedback are discussed. The oscillatory instability of the circular Couette flow under the thermoelectric body force and its relation with the waves will also be discussed. Authors acknowledge the financial support from the CNRS under the program PEPS-PTI OndInterGE.

  6. Annular suspension and pointing system with controlled DC electromagnets

    NASA Technical Reports Server (NTRS)

    Vu, Josephine Lynn; Tam, Kwok Hung

    1993-01-01

    The Annular Suspension and Pointing System (ASPS) developed by the Flight System division of Sperry Corporation is a six-degree of freedom payload pointing system designed for use with the space shuttle. This magnetic suspension and pointing system provides precise controlled pointing in six-degrees of freedom, isolation of payload-carrier disturbances, and end mount controlled pointing. Those are great advantages over the traditional mechanical joints for space applications. In this design, we first analyzed the assumed model of the single degree ASPS bearing actuator and obtained the plant dynamics equations. By linearizing the plant dynamics equations, we designed the cascade and feedback compensators such that a stable and satisfied result was obtained. The specified feedback compensator was computer simulated with the nonlinearized plant dynamics equations. The results indicated that an unstable output occurred. In other words, the designed feedback compensator failed. The failure of the design is due to the Taylor's series expansion not converging.

  7. Fluctuations of doublet splittings using the annular billiard

    SciTech Connect

    Egydio de Carvalho, R.; Mijolaro, A.P.

    2004-11-01

    We study the statistical distribution of quantum energy splittings due to a dynamical tunneling. The system, the annular billiard, has whispering quasimodes due to a discrete symmetry that exists even when chaos is present in the underlying classical dynamics. Symmetric and antisymmetric combinations of these quasimodes correspond to quantum doublet states whose degeneracies decrease as the circles become more eccentric. We construct numerical ensembles composed of splittings for two distinct regimes, one which we call semiclassical for high quantum numbers and high energies where the whispering regions are connected by chaos, and other which we call quantal for low quantum numbers, low energies, and near integrable where dynamical tunneling is not a dominant mechanism. In both cases we observe a variation on the fluctuation amplitudes, but their mean behaviors follow the formula of Leyvraz and Ullmo [J. Phys. A 29, 2529 (1996)]. A description of a three-level collision involving a doublet and a singlet is also provided through a numerical example.

  8. Annular-beam, 17 GHz free-electron maser experiment

    SciTech Connect

    Earley, L.M.; Carlsten, B.E.; Fazio, M.V.

    1997-06-01

    Experiments have been conducted on a 15-17 GHz free electron maser (FEM) for producing a 500 MW output pulse with a phase stability appropriate for linear collider applications. The electron beam source was a 1 {mu}s, 800 kV, 5 kA, 6-cm-dia annular electron beam machine called BANSHEE. The beam interacted with the TM{sub 02} and TM{sub 03} mode Raman FEM amplifier in a corrugated cylindrical waveguide where the beam runs close to the interaction device walls to reduce the power density in the fields. This greatly reduced the kinetic energy loss caused by the beam potential depression associated with the space charge which was a significant advantage in comparison with conventional solid beam microwave tubes at the same beam current. The experiment was operated in a single shot mode with a large number of diagnostics to measure power, frequency and energy.

  9. Annular plaques on the tongue: what is your diagnosis?

    PubMed

    Kayhan, Tuba Çelebĺ; Bĺlaç, Cemal; Bĺlaç, Dilek Bayraktar; Ecemĺş, Talat; Ermertcan, Aylin Türel

    2011-11-01

    Geographic tongue is an inflammatory disorder of the tongue characterized by asymptomatic erythematous patches with serpiginous borders. Candidiasis of the tongue may be confused with geographic tongue. A 63-year-old male patient with painful white annular lesions localized to the left side of his tongue is presented. He applied topical corticosteroid and antiinflammatory agents, but his lesions did not respond to those therapies. Using direct mycologic examination and culture, the patient was diagnosed with candidiasis. After systemic and topical antifungal therapy, clinical improvement was observed. With this case, the clinical forms of oral candidiasis were discussed, and it was suggested that the clinical presentation of mucosal candidiasis may vary according to the stage of infection and individual immunity. PMID:22148032

  10. Liquid Annular Seal CFD Analysis for Rotordynamic Force Prediction

    NASA Technical Reports Server (NTRS)

    Moore, Jeff; Palazzolo, Alan

    2006-01-01

    A commercially available code is utilized to analyze a plain and grooved liquid annular seal. These type seals are commonly used in modern turbopumps and have a pronounced effect on the rotordynamic behavior of these systems. Accurate prediction of both leakage and dynamic reaction forces is vital to ensure good performance and sound mechanical operation. The code SCISEAL developed by CFDRC is a generic 3-D, finite volume based CFD code solving the 3-D Reynolds averaged Navier Stokes equations. The code allows body-fitted, multi-blocked structured grids, turbulence modeling, rotating coordinate frames, as well as integration of dynamic pressure and shear forces on the rotating journal. The code may be used with the commercially available pre-and post-processing codes from CFDRC as well.

  11. Development of annular targets for {sup 99}MO production.

    SciTech Connect

    Conner, C.; Lewandowski, E. F.; Snelgrove, J. L.; Liberatore, M. W.; Walker, D. E.; Wiencek, T. C.; McGann, D. J.; Hofman, G. L.; Vandegrift, G. F.

    1999-09-30

    The new annular target performed well during irradiation. The target is inexpensive and provides good heat transfer during irradiation. Based on these and previous tests, we conclude that targets with zirconium tubes and either nickel-plated or zinc-plated foils work well. We proved that we could use aluminum target tubes, which are much cheaper and easier to work with than the zirconium tubes. In aluminum target tubes nickel-plated fission-recoil barriers work well and prevent bonding of the foil to the new target tubes during irradiation. Also, zinc-plated and aluminum-foil barriers appear promising in anodized aluminum tubes. Additional tests are anticipated to address such issues as fission-recoil barrier thickness and uranium foil composition. Overall, however, the target was successful and will provide an inexpensive, efficient way to irradiate LEU metal foil for the production of {sup 99}Mo.

  12. Annular billiard dynamics in a circularly polarized strong laser field

    NASA Astrophysics Data System (ADS)

    Kamor, A.; Mauger, F.; Chandre, C.; Uzer, T.

    2012-01-01

    We analyze the dynamics of a valence electron of the buckminsterfullerene molecule (C60) subjected to a circularly polarized laser field by modeling it with the motion of a classical particle in an annular billiard. We show that the phase space of the billiard model gives rise to three distinct trajectories: “whispering gallery orbits,” which hit only the outer billiard wall; “daisy orbits,” which hit both billiard walls (while rotating solely clockwise or counterclockwise for all time); and orbits that only visit the downfield part of the billiard, as measured relative to the laser term. These trajectories, in general, maintain their distinct features, even as the intensity is increased from 1010 to 1014Wcm-2. We attribute this robust separation of phase space to the existence of twistless tori.

  13. Experimental annular stratified flames characterisation stabilised by weak swirl

    SciTech Connect

    Bonaldo, A.; Kelman, J.B.

    2009-04-15

    A burner for the investigation of lean stratified premixed flames propagating in intense isotropic turbulence has been developed. Lean pre-mixtures of methane at different equivalence ratios were divided between two concentric co-flows to obtain annular stratification. Turbulence generators were used to control the level of turbulence intensity in the oncoming flow. A third annular weakly swirling airflow provided the flame stabilisation mechanism. A fundamental characteristic was that flame stabilisation did not rely on flow recirculation. The flames were maintained at a position where the local mass flux balanced the burning rate, resulting in a freely propagating turbulent flame front. The absence of physical surfaces in the vicinity of the flame provided free access for laser diagnostics. Stereoscopic Planar Image Velocimetry (SPIV) was applied to obtain the three components of the instantaneous velocity vectors on a vertical plane above the burner at the point of flame stabilisation. The instantaneous temperature fields were determined through Laser Induced Rayleigh (LIRay) scattering. Planar Laser Induced Fluorescence (PLIF) of acetone was used to calculate the average equivalence ratio distributions. Instantaneous turbulent burning velocities were extracted from SPIV results, while flame curvature and flame thermal thickness were calculated using the instantaneous temperature fields. The PDFs of these quantities were analysed to consider the separate influence of equivalence ratio stratification and turbulence. Increased levels of turbulence resulted in the expected higher turbulent burning velocities and flame front wrinkling. Flames characterised by higher fuel gradients showed higher turbulent burning velocities. Increased fuel concentration gradients gave rise to increased flame wrinkling, particularly when associated with positive small radius of curvature. (author)

  14. Control of Smokestack Downwash Using a Concentric Annular Synthetic Jet

    NASA Astrophysics Data System (ADS)

    Sigurdson, Lorenz; Diep, John

    2001-11-01

    The objective was to discover and evaluate methods of smokestack downwash reduction using unsteady forcing. The flow was essentially a low momentum jet in a crossflow. After preliminary investigations of several concepts, the final wind-tunnel model applied an annular synthetic jet coaxially to a turbulent or laminar pipe flow at the stack exit. The cross-wind Reynolds number based on stack diameter was on the order of 1000. Primary diagnostics were hot-wire measurements and image processing of smoke flow visualization photographs of the plume gas. For a laminar pipe flow and increasing forcing amplitude, the initially turbulent plume can be made to completely relaminarize and then become turbulent again at higher amplitudes. Therefore an increased forcing does not always increase mixing. An abrupt transition of vortex structure appears at a particular amplitude. An inverse indication of downwash was obtained by measuring the plume height at a fixed downstream location. For a turbulent pipe flow, the synthetic jet causes an increase in plume height of up to 1.8 stack diameters. The increase using a synthetic jet is greater than using steady annular blowing of similar velocity, and can be almost 100cross-wind velocity ratios. Synthetic jet momentum dominates the forced plume at high forcing amplitudes. A simple model based on this idea collapses the measured synthetic jet-forced plume height data as a function of a scaled forcing velocity, for various plume to cross-stream velocity ratios. This data compares well with reference unforced plumes using the same scaling.

  15. Nanda-gikendaasowin Naawij Gaa-izhiwebakin Manoomini-zaaga'iganiing: Core-based research by Native students on wild rice lakes in northern Minnesota

    NASA Astrophysics Data System (ADS)

    Myrbo, A.; Howes, T.; Defoe, R.; Dalbotten, D. M.; Pellerin, H.; McEathron, M.; Ito, E.

    2011-12-01

    Little is known about how local and global environmental changes affect the habitat of wild rice (manoomin in Ojibwe; Zizania sp.). Using transects of sediment cores from wild rice lakes on the Fond du Lac Band of Lake Superior Chippewa Reservation (FDL) in Minnesota, undergraduate student researchers are working to reconstruct the lakes' ecological history in order to better manage future change. Reservation Resource Management personnel and University science mentors work together to develop research questions and mentor small groups of college-age students during short (two-week) and long (ten-week) summer internships. Cores are collected during the winter from the frozen lake surface with "Lake Teams" of mainly Native junior high and high school students attending weekend science camps, who also visit LacCore (the National Lacustrine Core Facility) in Minneapolis to conduct initial core description and basic analyses. At the same time as the Fond du Lac Band gains information about the long-term history and variability of the Reservation's lakes, young Native people are exposed to primary research, natural resources management and academia as occupations, and scientists as people. Scientific results, as well as the results of program evaluation, show clearly that this approach has so far been successful and eye-opening for both students and mentors. Lead-210 dated records of the past ~150 years cover the period of European settlement, logging, and the massive ditching of FDL lakes to convert wetlands to agricultural land. Phytolith, pollen, plant macrofossil, and diatom studies by interns, as well as sediment composition and mass accumulation rate data, show anthropogenic lake level and vegetation fluctuations associated with these activities. Earlier in the record (~10,000 years to ~100 years before present), the natural and slow processes of lake infilling and encroachment of shallow-water vegetation are the dominant processes controlling the ecology of the

  16. Influence of thermal deformations of resonators on propagation properties of laser annular beams through turbulent atmosphere

    NASA Astrophysics Data System (ADS)

    Peng, Yufeng; Peng, Fang; Han, Junpeng

    2013-02-01

    Based on the laser field from a positive confocal unstable resonator, considering the influence of thermal distortion of the internal resonator mirror on the annular beam, the propagation characteristics of the annular beam through turbulent atmosphere are investigated by means of the fast Fourier transform algorithm (FFT). The intensity distributions of the output laser far-field are obtained to analyze the propagation characteristics of laser annular beam through the turbulent atmosphere, which is a function about different propagation distances. The results show that the peak intensity of the laser pattern becomes depressed and the spread of the far field diagram patterns is broadened under the increasing of the transmission distance and the thermal distortion of the laser resonator. β-parameter and strehl ratio are introduced to estimate the annular beam quality characteristics. It is found that the annular beam through strong turbulence influences much less obviously than the annular beam through weak turbulence on the quality characteristics with thermal distortion. In the same atmospheric conditions with a certain distance, the greater the mirror thermal distortion is, the worse the annular beam quality characteristics is.

  17. Environmental Health Research Recommendations from the Inter-Environmental Health Sciences Core Center Working Group on Unconventional Natural Gas Drilling Operations

    PubMed Central

    Breysse, Patrick N.; Gray, Kathleen; Howarth, Marilyn; Yan, Beizhan

    2014-01-01

    Background: Unconventional natural gas drilling operations (UNGDO) (which include hydraulic fracturing and horizontal drilling) supply an energy source that is potentially cleaner than liquid or solid fossil fuels and may provide a route to energy independence. However, significant concerns have arisen due to the lack of research on the public health impact of UNGDO. Objectives: Environmental Health Sciences Core Centers (EHSCCs), funded by the National Institute of Environmental Health Sciences (NIEHS), formed a working group to review the literature on the potential public health impact of UNGDO and to make recommendations for needed research. Discussion: The Inter-EHSCC Working Group concluded that a potential for water and air pollution exists that might endanger public health, and that the social fabric of communities could be impacted by the rapid emergence of drilling operations. The working group recommends research to inform how potential risks could be mitigated. Conclusions: Research on exposure and health outcomes related to UNGDO is urgently needed, and community engagement is essential in the design of such studies. Citation: Penning TM, Breysse PN, Gray K, Howarth M, Yan B. 2014. Environmental health research recommendations from the Inter-Environmental Health Sciences Core Center Working Group on Unconventional Natural Gas Drilling Operations. Environ Health Perspect 122:1155–1159; http://dx.doi.org/10.1289/ehp.1408207 PMID:25036093

  18. Biospecimen Core Resource - TCGA

    Cancer.gov

    The Cancer Genome Atlas (TCGA) Biospecimen Core Resource centralized laboratory reviews and processes blood and tissue samples and their associated data using optimized standard operating procedures for the entire TCGA Research Network.

  19. NEUTRONIC REACTOR OPERATIONAL METHOD AND CORE SYSTEM

    DOEpatents

    Winters, C.E.; Graham, C.B.; Culver, J.S.; Wilson, R.H.

    1960-07-19

    Homogeneous neutronic reactor systems are described wherein an aqueous fuel solution is continuously circulated through a spherical core tank. The pumped fuel solution-is injected tangentially into the hollow spherical interior, thereby maintaining vigorous rotation of the solution within the tank in the form of a vortex; gaseous radiolytic decomposition products concentrate within the axial vortex cavity. The evolved gas is continuously discharged through a gas- outlet port registering with an extremity of the vortex cavity. and the solution stream is discharged through an annular liquid outlet port concentrically encircling the gas outlet by virtue of which the vortex and its cavity are maintained precisely axially aligned with the gas outlet. A primary heat exchanger extracts useful heat from the hot effluent fuel solution before its recirculation into the core tank. Hollow cylinders and other alternative core- tank configurations defining geometric volumes of revolution about a principal axis are also covered. AEC's Homogeneous Reactor Experiment No. 1 is a preferred embodiment.

  20. LMFBR in-core thermal-hydraulics: the state of the art and US research and development needs

    SciTech Connect

    Khan, E.U.

    1980-04-01

    A detailed critical review is presented of the literature relevant to predicting coolant flow and temperature fields in LMFBR core assemblies for nominal and non-nominal rod bundle geometries and reactor operating conditions. The review covers existing thermal-hydraulic models, computational methods, and experimental data useful for the design of an LMFBR core. The literature search made for this review included publications listed by Nuclear Science Abstracts and Energy Data Base as well as papers presented at key nuclear conferences. Based on this extensive review, the report discusses the accuracy with which the models predict flow and temperature fields in rod assemblies, identifying areas where analytical, experimental, and model development needs exist.

  1. Characterization of annular two-phase gas-liquid flows in microgravity

    NASA Technical Reports Server (NTRS)

    Bousman, W. Scott; Mcquillen, John B.

    1994-01-01

    A series of two-phase gas-liquid flow experiments were developed to study annular flows in microgravity using the NASA Lewis Learjet. A test section was built to measure the liquid film thickness around the perimeter of the tube permitting the three dimensional nature of the gas-liquid interface to be observed. A second test section was used to measure the film thickness, pressure drop and wall shear stress in annular microgravity two-phase flows. Three liquids were studied to determine the effects of liquid viscosity and surface tension. The result of this study provide insight into the wave characteristics, pressure drop and droplet entrainment in microgravity annular flows.

  2. On the Motion of an Annular Film in Microgravity Gas-Liquid Flow

    NASA Technical Reports Server (NTRS)

    McQuillen, John B.

    2002-01-01

    Three flow regimes have been identified for gas-liquid flow in a microgravity environment: Bubble, Slug, and Annular. For the slug and annular flow regimes, the behavior observed in vertical upflow in normal gravity is similar to microgravity flow with a thin, symmetrical annular film wetting the tube wall. However, the motion and behavior of this film is significantly different between the normal and low gravity cases. Specifically, the liquid film will slow and come to a stop during low frequency wave motion or slugging. In normal gravity vertical upflow, the film has been observed to slow, stop, and actually reverse direction until it meets the next slug or wave.

  3. Transverse Vibration Of Annular Circular And Elliptic Plates Using The Characteristic Orthogonal Polynomials In Two Dimensions

    NASA Astrophysics Data System (ADS)

    Singh, B.; Chakraverty, S.

    1993-04-01

    Characteristic orthogonal polynomials in two variables have been generated over the annular region occupied by a circular or elliptic plate satisfying the essential boundary conditions. These are used to express the displacement in the transverse vibration of the plate. The Rayleigh-Ritz method is then applied to study the fundamental mode of vibration. Comparison has been made with the known results for circular annular plates in some cases. The results for the elliptic annular plate are entirely new and are not available elsewhere. All the results are summarized in tables covering various combinations of the boundary conditions.

  4. HYDRATE CORE DRILLING TESTS

    SciTech Connect

    John H. Cohen; Thomas E. Williams; Ali G. Kadaster; Bill V. Liddell

    2002-11-01

    The ''Methane Hydrate Production from Alaskan Permafrost'' project is a three-year endeavor being conducted by Maurer Technology Inc. (MTI), Noble, and Anadarko Petroleum, in partnership with the U.S. DOE National Energy Technology Laboratory (NETL). The project's goal is to build on previous and ongoing R&D in the area of onshore hydrate deposition. The project team plans to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope includes drilling and coring one well on Anadarko leases in FY 2003 during the winter drilling season. A specially built on-site core analysis laboratory will be used to determine some of the physical characteristics of the hydrates and surrounding rock. Prior to going to the field, the project team designed and conducted a controlled series of coring tests for simulating coring of hydrate formations. A variety of equipment and procedures were tested and modified to develop a practical solution for this special application. This Topical Report summarizes these coring tests. A special facility was designed and installed at MTI's Drilling Research Center (DRC) in Houston and used to conduct coring tests. Equipment and procedures were tested by cutting cores from frozen mixtures of sand and water supported by casing and designed to simulate hydrate formations. Tests were conducted with chilled drilling fluids. Tests showed that frozen core can be washed out and reduced in size by the action of the drilling fluid. Washing of the core by the drilling fluid caused a reduction in core diameter, making core recovery very difficult (if not impossible). One successful solution was to drill the last 6 inches of core dry (without fluid circulation). These tests demonstrated that it will be difficult to capture core when drilling in permafrost or hydrates without implementing certain safeguards. Among the coring tests was a simulated hydrate formation comprised of coarse, large

  5. Study of secondary-flow patterns in an annular cascade of turbine nozzle blades with vortex design

    NASA Technical Reports Server (NTRS)

    Rohlik, Harold E; Allen, Hubert W; Herzig, Howard Z

    1953-01-01

    In order to increase understanding of the origin of losses in a turbine, the secondary-flow components in the boundary layers and the blade wakes of an annular cascade of turbine nozzle blades (vortex design) was investigated. A detailed study was made of the total-pressure contours and, particularly, of the inner-wall loss cores downstream of the blades. The inner-wall loss core associated with a blade of the turbine-nozzle cascade is largely the accumulation of low-momentum fluids originating elsewhere in the cascade. This accumulation is effected by a secondary-flow mechanism which acts to transport the low-momentum fluids across the channels on the walls and radially in the blade wakes and boundary layers. The patterns of secondary flow were determined by use of hydrogen sulfide traces, paint, flow fences, and total pressure surveys. At one flow condition investigated, the radial transport of low-momentum fluid in the blade wake and on the suction surface near the trailing edge accounted for 65 percent of the loss core; 30 percent resulted from flow in the thickened boundary layer on the suction surface and 35 percent from flow in the blade wake.

  6. A deployable, annular, 30m telescope, space-based observatory

    NASA Astrophysics Data System (ADS)

    Rey, Justin J.; Wirth, Allan; Jankevics, Andrew; Landers, Franklin; Rohweller, David; Chen, C. Bill; Bronowicki, Allen

    2014-08-01

    High resolution imaging from space requires very large apertures, such as NASA's current mission the James Webb Space Telescope (JWST) which uses a deployable 6.5m segmented primary. Future missions requiring even larger apertures (>>10m) will present a great challenge relative to the size, weight and power constraints of launch vehicles as well as the cost and schedule required to fabricate the full aperture. Alternatively, a highly obscured annular primary can be considered. For example, a 93.3% obscured 30m aperture having the same total mirror area (91m2) as a 10.7m unobscured telescope, can achieve ~3X higher limiting resolution performance. Substantial cost and schedule savings can be realized with this approach compared to fully filled apertures of equivalent resolution. A conceptual design for a ring-shaped 30m telescope is presented and the engineering challenges of its various subsystems analyzed. The optical design consists of a 20X annular Mersenne form beam compactor feeding a classical 1.5m TMA telescope. Ray trace analysis indicates the design can achieve near diffraction limited images over a 200μrad FOV. The primary mirror consists of 70 identical rectangular 1.34x1.0m segments with a prescription well within the demonstrated capabilities of the replicated nanolaminate on SiC substrate technology developed by AOA Xinetics. A concept is presented for the deployable structure that supports the primary mirror segments. A wavefront control architecture consisting of an optical metrology subsystem for coarse alignment and an image based fine alignment and phasing subsystem is presented. The metrology subsystem is image based, using the background starfields for distortion and pointing calibration and fiducials on the segments for measurement. The fine wavefront control employs a hill climbing algorithm operating on images from the science camera. The final key technology required is the image restoration algorithm that will compensate for the highly

  7. An iterative method for the solution of nonlinear systems using the Faber polynomials for annular sectors

    SciTech Connect

    Myers, N.J.

    1994-12-31

    The author gives a hybrid method for the iterative solution of linear systems of equations Ax = b, where the matrix (A) is nonsingular, sparse and nonsymmetric. As in a method developed by Starke and Varga the method begins with a number of steps of the Arnoldi method to produce some information on the location of the spectrum of A. This method then switches to an iterative method based on the Faber polynomials for an annular sector placed around these eigenvalue estimates. The Faber polynomials for an annular sector are used because, firstly an annular sector can easily be placed around any eigenvalue estimates bounded away from zero, and secondly the Faber polynomials are known analytically for an annular sector. Finally the author gives three numerical examples, two of which allow comparison with Starke and Varga`s results. The third is an example of a matrix for which many iterative methods would fall, but this method converges.

  8. Method of improving image sharpness for annular-illumination scanning electron microscopes

    NASA Astrophysics Data System (ADS)

    Enyama, Momoyo; Hamada, Koichi; Fukuda, Muneyuki; Kazumi, Hideyuki

    2016-06-01

    Annular illumination is effective in enhancing the depth of focus for scanning electron microscopes (SEMs). However, owing to high side lobes of the point-spread function (PSF), annular illumination results in poor image sharpness. The conventional deconvolution method, which converts the PSF to a delta function, can improve image sharpness, but results in artifacts due to noise amplification. In this paper, we propose an image processing method that can reduce the deterioration of image sharpness. With this method, the PSF under annular illumination is converted to that under standard illumination. Through simulations, we verified that the image sharpness of SEM images under annular illumination with the proposed method can be improved without noise amplification.

  9. Biofilm Community Dynamics in Bench-Scale Annular Reactors Simulating Arrestment of Chloraminated Drinking Water Nitrification

    EPA Science Inventory

    Annular reactors (ARs) were used to study biofilm community succession and provide an ecological insight during nitrification arrestment through simultaneously increasing monochloramine (NH2Cl) and chlorine to nitrogen mass ratios, resulting in four operational periods (I to IV)....

  10. The influence of the equivalent hydraulic diameter on the pressure drop prediction of annular test section

    NASA Astrophysics Data System (ADS)

    Al-Kayiem, A. H. H.; Ibrahim, M. A.

    2015-12-01

    The flow behaviour and the pressure drop throughout an annular flow test section was investigated in order to evaluate and justify the reliability of experimental flow loop for wax deposition studies. The specific objective of the present paper is to assess and highlight the influence of the equivalent diameter method on the analysis of the hydrodynamic behaviour of the flow and the pressure drop throughout the annular test section. The test section has annular shape of 3 m length with three flow passages, namely; outer thermal control jacket, oil annular flow and inner pipe flow of a coolant. The oil annular flow has internal and external diameters of 0.0422 m and 0.0801 m, respectively. Oil was re-circulated in the annular passage while a cold water-glycol mixture was re-circulated in the inner pipe counter currently to the oil flow. The experiments were carried out at oil Reynolds number range of 2000 to 17000, covering laminar, transition and turbulent flow regimes. Four different methods of equivalent diameter of the annulus have been considered in this hydraulic analysis. The correction factor model for frictional pressure drop was also considered in the investigations. All methods addressed the high deviation of the prediction from the experimental data, which justified the need of a suitable pressure prediction correlation for the annular test section. The conventional hydraulic diameter method is a convenient substitute for characterizing physical dimension of a non-circular duct, and it leads to fairly good correlation between turbulent fluid flow and heat transfer characteristic of annular ducts.

  11. An X-band high-impedance relativistic klystron amplifier with an annular explosive cathode

    NASA Astrophysics Data System (ADS)

    Zhu, Danni; Zhang, Jun; Zhong, Huihuang; Qi, Zumin

    2015-11-01

    The feasibility of employing an annular beam instead of a solid one in the X-band high-impedance relativistic klystron amplifier (RKA) is investigated in theory and simulation. Small-signal theory analysis indicates that the optimum bunching distance, fundamental current modulation depth, beam-coupling coefficient, and beam-loaded quality factor of annular beams are all larger than the corresponding parameters of solid beams at the same beam voltage and current. An annular beam RKA and a solid beam RKA with almost the same geometric parameters are compared in particle-in-cell simulation. Output microwave power of 100 MW, gain of 50 dB, and power conversion efficiency of 42% are obtained in an annular beam RKA. The annular beam needs a 15% lower uniform guiding magnetic field than the solid beam. Our investigations demonstrate that we are able to use a simple annular explosive cathode immersed in a lower uniform magnetic field instead of a solid thermionic cathode in a complicated partially shielding magnetic field for designing high-impedance RKA, which avoids high temperature requirement, complicated electron-optical system, large area convergence, high current density, and emission uniformity for the solid beam. An equivalent method for the annular beam and the solid beam on bunching features is proposed and agrees with the simulation. The annular beam has the primary advantages over the solid beam that it can employ the immersing uniform magnetic field avoiding the complicated shielding magnetic field system and needs a lower optimum guiding field due to the smaller space charge effect.

  12. Phase reconstruction in annular bright-field scanning transmission electron microscopy.

    PubMed

    Ishida, Takafumi; Kawasaki, Tadahiro; Tanji, Takayoshi; Kodama, Tetsuji; Matsutani, Takaomi; Ogai, Keiko; Ikuta, Takashi

    2015-04-01

    A novel technique for reconstructing the phase shifts of electron waves was applied to Cs-corrected scanning transmission electron microscopy (STEM). To realize this method, a new STEM system equipped with an annular aperture, annularly arrayed detectors and an arrayed image processor has been developed and evaluated in experiments. We show a reconstructed phase image of graphite particles and demonstrate that this new method works effectively for high-resolution phase imaging. PMID:25387907

  13. An X-band high-impedance relativistic klystron amplifier with an annular explosive cathode

    SciTech Connect

    Zhu, Danni; Zhang, Jun Zhong, Huihuang; Qi, Zumin

    2015-11-15

    The feasibility of employing an annular beam instead of a solid one in the X-band high-impedance relativistic klystron amplifier (RKA) is investigated in theory and simulation. Small-signal theory analysis indicates that the optimum bunching distance, fundamental current modulation depth, beam-coupling coefficient, and beam-loaded quality factor of annular beams are all larger than the corresponding parameters of solid beams at the same beam voltage and current. An annular beam RKA and a solid beam RKA with almost the same geometric parameters are compared in particle-in-cell simulation. Output microwave power of 100 MW, gain of 50 dB, and power conversion efficiency of 42% are obtained in an annular beam RKA. The annular beam needs a 15% lower uniform guiding magnetic field than the solid beam. Our investigations demonstrate that we are able to use a simple annular explosive cathode immersed in a lower uniform magnetic field instead of a solid thermionic cathode in a complicated partially shielding magnetic field for designing high-impedance RKA, which avoids high temperature requirement, complicated electron-optical system, large area convergence, high current density, and emission uniformity for the solid beam. An equivalent method for the annular beam and the solid beam on bunching features is proposed and agrees with the simulation. The annular beam has the primary advantages over the solid beam that it can employ the immersing uniform magnetic field avoiding the complicated shielding magnetic field system and needs a lower optimum guiding field due to the smaller space charge effect.

  14. Vibration Analysis of Annular Plates with Concentric Supports Using a Variant of Rayleigh-Ritz Method

    NASA Astrophysics Data System (ADS)

    Wang, C. M.; Thevendran, V.

    1993-05-01

    A variant of the Rayleigh-Ritz method is presented for solving the free vibration problem of annular plates with internal axisymmetric supports. The method is simple, accurate and may be readily programmed and run on a microcomputer. A comprehensive tabulation of the fundamental frequencies is presented for isotropic annular plates with an internal concentric support. Results for full circular plates with concentric supports are also obtained by making the inner radial edge free and permitting the inner radius to become very small.

  15. Phase reconstruction in annular bright-field scanning transmission electron microscopy.

    PubMed

    Ishida, Takafumi; Kawasaki, Tadahiro; Tanji, Takayoshi; Kodama, Tetsuji; Matsutani, Takaomi; Ogai, Keiko; Ikuta, Takashi

    2015-04-01

    A novel technique for reconstructing the phase shifts of electron waves was applied to Cs-corrected scanning transmission electron microscopy (STEM). To realize this method, a new STEM system equipped with an annular aperture, annularly arrayed detectors and an arrayed image processor has been developed and evaluated in experiments. We show a reconstructed phase image of graphite particles and demonstrate that this new method works effectively for high-resolution phase imaging.

  16. Harmonising data collection from osteoarthritis studies to enable stratification: recommendations on core data collection from an Arthritis Research UK clinical studies group

    PubMed Central

    Corp, Nadia; Watt, Fiona E.; Felson, David T.; O’Neill, Terence W.; Holt, Cathy A.; Jones, Richard K.; Conaghan, Philip G.; Arden, Nigel K.

    2016-01-01

    Objective. Treatment of OA by stratifying for commonly used and novel therapies will likely improve the range of effective therapy options and their rational deployment in this undertreated, chronic disease. In order to develop appropriate datasets for conducting post hoc analyses to inform approaches to stratification for OA, our aim was to develop recommendations on the minimum data that should be recorded at baseline in all future OA interventional and observational studies. Methods. An Arthritis Research UK study group comprised of 32 experts used a Delphi-style approach supported by a literature review of systematic reviews to come to a consensus on core data collection for OA studies. Results. Thirty-five systematic reviews were used as the basis for the consensus group discussion. For studies with a primary structural endpoint, core domains for collection were defined as BMI, age, gender, racial origin, comorbidities, baseline OA pain, pain in other joints and occupation. In addition to the items generalizable to all anatomical sites, joint-specific domains included radiographic measures, surgical history and anatomical factors, including alignment. To demonstrate clinical relevance for symptom studies, the collection of mental health score, self-efficacy and depression scales were advised in addition to the above. Conclusions. Currently it is not possible to stratify patients with OA into therapeutic groups. A list of core and optional data to be collected in all OA interventional and observational studies was developed, providing a basis for future analyses to identify predictors of progression or response to treatment. PMID:27084310

  17. Capacitive micromachined ultrasonic transducers based on annular cell geometry for air-coupled applications.

    PubMed

    Na, Shuai; Chen, Albert I H; Wong, Lawrence L P; Li, Zhenhao; Macecek, Mirek; Yeow, John T W

    2016-09-01

    A novel design of an air-coupled capacitive micromachined ultrasonic transducer (CMUT) with annular cell geometry (annular CMUT) is proposed. Finite element analysis shows that an annular cell has a ratio of average-to-maximum displacement (RAMD) of 0.52-0.58 which is 58-76% higher than that of a conventional circular cell. The increased RAMD leads to a larger volume displacement which results in a 48.4% improved transmit sensitivity and 127.3% improved power intensity. Single-cell annular CMUTs were fabricated with 20-μm silicon plates on 13.7-μm deep and 1.35-mm wide annular cavities using the wafer bonding technique. The measured RAMD of the fabricated CMUTs is 0.54. The resonance frequency was measured to be 94.5kHz at 170-V DC bias. The transmit sensitivity was measured to be 33.83Pa/V and 25.85Pa/V when the CMUT was excited by a continuous wave and a 20-cycle burst, respectively. The receive sensitivity at 170-V DC bias was measured to be 7.7mV/Pa for a 20-cycle burst, and 15.0mV/Pa for a continuous incident wave. The proposed annular CMUT design demonstrates a significant improvement in transmit efficiency, which is an important parameter for air-coupled ultrasonic transducers. PMID:27352025

  18. Jet mixing and emission characteristics of transverse jets in annular and cylindrical confined crossflow

    NASA Technical Reports Server (NTRS)

    Bain, D. B.; Smith, C. E.; Holdeman, J. D.

    1995-01-01

    Three dimensional turbulent reacting CFD analyses were performed on transverse jets injected into annular and cylindrical (can) confined crossflows. The goal was to identify and assess mixing differences between annular and can geometries. The approach taken was to optimize both annular and can configurations by systematically varying orifice spacing until lowest emissions were achieved, and then compare the results. Numerical test conditions consisted of a jet-to-mainstream mass-flow ratio of 3.2 and a jet-to-mainstream momentum-flux ratio (J) of 30. The computational results showed that the optimized geometries had similar emission levels at the exit of the mixing section although the annular configuration did mix-out faster. For lowest emissions, the density correlation parameter (C = (S/H) square root of J) was 2.35 for the annular geometry and 3.5 for the can geometry. For the annular geometry, the constant was about twice the value seen for jet mixing at low mass-flow ratios (i.e., MR less than 0.5). For the can geometry, the constant was about 1 1/2 times the value seen for low mass-flow ratios.

  19. Design and characterization of the annular cathode high current pulsed electron beam source for circular components

    NASA Astrophysics Data System (ADS)

    Jiang, Wei; Wang, Langping; Wang, Xiaofeng

    2016-08-01

    In order to irradiate circular components with high current pulsed electron beam (HCPEB), an annular cathode based on carbon fiber bunches was designed and fabricated. Using an acceleration voltage of 25 kV, the maximum pulsed irradiation current and energy of this annular cathode can reach 7.9 kA and 300 J, respectively. The irradiation current density distribution of the annular cathode HCPEB source measured along the circumferential direction shows that the annular cathode has good emission uniformity. In addition, four 9310 steel substrates fixed uniformly along the circumferential direction of a metal ring substrate were irradiated by this annular cathode HCPEB source. The surface and cross-section morphologies of the irradiated samples were characterized by scanning electron microscopy (SEM). SEM images of the surface reveal that crater and surface undulation have been formed, which hints that the irradiation energy of the HCPEB process is large enough for surface modification of 9310 steel. Meanwhile, SEM cross-section images exhibit that remelted layers with a thickness of about 5.4 μm have been obtained in all samples, which proves that a good practical irradiation uniformity can be achieved by this annular cathode HCPEB source.

  20. Depth-targeted transvascular drug delivery by using annular-shaped photomechanical waves

    NASA Astrophysics Data System (ADS)

    Akiyama, Takuya; Sato, Shunichi; Ashida, Hiroshi; Terakawa, Mitsuhiro

    2011-02-01

    Laser-based drug delivery is attractive for the targeting capability due to high spatial controllability of laser energy. Recently, we found that photomechanical waves (PMWs) can transiently increase the permeability of blood vessels in skin, muscle and brain of rats. In this study, we examined the use of annular-shaped PMWs to increase pressure at target depths due to superposition effect of pressure waves. This can increase the permeability of blood vessels located in the specific depth regions, enabling depth-targeted transvascular drug delivery. Annular PMWs were produced by irradiating a laser-absorbing material with annular-shaped pulsed laser beams that were produced by using an axicon lens. We first examined propagation and pressure characteristics of annular PMWs in tissue phantoms and confirmed an increased pressure at a target depth, which can be controlled by changing laser parameters. We injected Evans blue (EB) into a rat tail vein, and annular PMWs (inner diameter, 3 mm; outer diameter, 5 mm) were applied from the myofascial surface of the anterior tibialis muscle. After perfusion fixation, we observed fluorescence originating from EB in the tissue. We observed intense fluorescence at a target depth region of around 5 mm. These results demonstrate the capability of annular PMWs for depth-targeted transvascular drug delivery.

  1. Flow Pressure Loss through Straight Annular Corrugated Pipes

    NASA Technical Reports Server (NTRS)

    Sargent, Joseph R.; Kirk, Daniel R.; Marsell, Brandon; Roth, Jacob; Schallhorn, Paul A.; Pitchford, Brian; Weber, Chris; Bulk, Timothy

    2016-01-01

    Pressure loss through annular corrugated pipes, using fully developed gaseous nitrogen representing purge pipes in spacecraft fairings, was studied to gain insight into a friction factor coefficient for these pipes. Twelve pipes were tested: four Annuflex, four Masterflex and two Titeflex with ¼”, 3/8”, ½” and ¾” inner diameters. Experimental set-up was validated using smooth-pipe and showed good agreement to the Moody diagram. Nitrogen flow rates between 0-200 standard cubic feet per hour were used, producing approximate Reynolds numbers from 300-23,000. Corrugation depth varied from 0.248 = E/D = 0.349 and relative corrugation pitch of 0.192 = P/D = 0.483. Differential pressure per unit length was measured and calculated using 8-9 equidistant pressure taps. A detailed experimental uncertainty analysis, including correlated bias error terms, is presented. Results show larger differential pressure losses than smooth-pipes with similar inner diameters resulting in larger friction factor coefficients.

  2. Experimental investigation of the low NOx vortex airblast annular combustor

    NASA Technical Reports Server (NTRS)

    Johnson, S. M.; Biaglow, J. A.; Smith, J. M.

    1984-01-01

    A low oxides of nitrogen vortex airblast annular combustor was evaluated which has attained the goal of 1 gm NO2/kg fuel or less during operation. The experimental combustor test conditions were a nominal inlet-air temperature of 703 K, inlet total pressures between 0.52 to 0.83 MPa, and a constant inlet Mach number of 0.26. Exit temperature pattern factors for all test points were between 0.16 and 0.20 and exit swirl flow angles were 47 degrees at isothermal conditions and 23 degrees during combustion. Oxides of nitrogen did not exceed 1.05 gm NO2/kg fuel at the highest inlet pressure and exhaust temperature tested. Previous correlations have related NOx proportionally to the combustor inlet pressure raised to some exponent. In this experiment, a band of exponents between 0.5 and 1.0 resulted for fuel-air ratios from 0.023 to 0.027 and inlet pressures from 0.52 to 0.83 MPa. Previously announced in STAR as N84-22567

  3. Adaptive control system for large annular momentum control device

    NASA Technical Reports Server (NTRS)

    Montgomery, R. C.; Johnson, C. R., Jr.

    1981-01-01

    A dual momentum vector control concept, consisting of two counterrotating rings (each designated as an annular momentum control device), was studied for pointing and slewing control of large spacecraft. In a disturbance free space environment, the concept provides for three axis pointing and slewing capabilities while requiring no expendables. The approach utilizes two large diameter counterrotating rings or wheels suspended magnetically in many race supports distributed around the antenna structure. When the magnets are energized, attracting the two wheels, the resulting gyroscopic torque produces a rate along the appropriate axis. Roll control is provided by alternating the radiative rotational velocity of the two wheels. Wheels with diameters of 500 to 800 m and with sufficient momentum storage capability require rims only a few centimeters thick. The wheels are extremely flexible; therefore, it is necessary to account for the distributed nature of the rings in the design of the bearing controllers. Also, ring behavior is unpredictably sensitive to ring temperature, spin rate, manufacturing imperfections, and other variables. An adaptive control system designed to handle these problems is described.

  4. Current Density Measurements of an Annular-Geometry Ion Engine

    NASA Technical Reports Server (NTRS)

    Shastry, Rohit; Patterson, Michael J.; Herman, Daniel A.; Foster, John E.

    2012-01-01

    The concept of the annular-geometry ion engine, or AGI-Engine, has been shown to have many potential benefits when scaling electric propulsion technologies to higher power. However, the necessary asymmetric location of the discharge cathode away from thruster centerline could potentially lead to non-uniformities in the discharge not present in conventional geometry ion thrusters. In an effort to characterize the degree of this potential nonuniformity, a number of current density measurements were taken on a breadboard AGI-Engine. Fourteen button probes were used to measure the ion current density of the discharge along a perforated electrode that replaced the ion optics during conditions of simulated beam extraction. Three Faraday probes spaced apart in the vertical direction were also used in a separate test to interrogate the plume of the AGI-Engine during true beam extraction. It was determined that both the discharge and the plume of the AGI-Engine are highly uniform, with variations under most conditions limited to 10% of the average current density in the discharge and 5% of the average current density in the plume. Beam flatness parameter measured 30 mm from the ion optics ranged from 0.85 0.95, and overall uniformity was shown to generally increase with increasing discharge and beam currents. These measurements indicate that the plasma is highly uniform despite the asymmetric location of the discharge cathode.

  5. Annular beam shaping system for advanced 3D laser brazing

    NASA Astrophysics Data System (ADS)

    Pütsch, Oliver; Stollenwerk, Jochen; Kogel-Hollacher, Markus; Traub, Martin

    2012-10-01

    As laser brazing benefits from advantages such as smooth joints and small heat-affected zones, it has become established as a joining technology that is widely used in the automotive industry. With the processing of complex-shaped geometries, recent developed brazing heads suffer, however, from the need for continuous reorientation of the optical system and/or limited accessibility due to lateral wire feeding. This motivates the development of a laser brazing head with coaxial wire feeding and enhanced functionality. An optical system is designed that allows to generate an annular intensity distribution in the working zone. The utilization of complex optical components avoids obscuration of the optical path by the wire feeding. The new design overcomes the disadvantages of the state-of-the-art brazing heads with lateral wire feeding and benefits from the independence of direction while processing complex geometries. To increase the robustness of the brazing process, the beam path also includes a seam tracking system, leading to a more challenging design of the whole optical train. This paper mainly discusses the concept and the optical design of the coaxial brazing head, and also presents the results obtained with a prototype and selected application results.

  6. Annular flow entrainment rate experiment in a vertical pipe

    SciTech Connect

    Lopez de Bertodano, M.A.; Jan, C.-S.; Beus, S.G.

    1996-06-01

    An air-water experiment has been performed to measure the entrainment rate in a small pipe. The current data extend the available database in the literature to higher gas and liquid flows and also to higher pressures. The ranges covered are 8.1 {times} 10{sup 2} kg/m{sup 2}s {lt} (gas flux rate) {lt} 4.5 {times} 10{sup 4} kg/m{sup 2}s, 5.5 kg/m{sup 2}s {lt} (liquid flux rate) {lt} 2.9 {times} 10{sup 2}s and 140 CPU {lt} PP {lt} 660 CPU. The test section has an internal diameter of 9.5 mm and an L/D ratio of 440. The measurements were made by extracting the liquid film at two locations establishing fully developed annular flow. The data were validated by visual observation and comparisons with the data of Cousins and Hewitt. A mechanism for the entrainment rate in terms of Taylor`s ripple instability is proposed. The theory is modified to include the effect of the inertia of the droplets in the gas stream. The model results in a dimensionless group that includes the Weber number based on the droplet concentration and the liquid film Reynolds number. Kataoka and Ishii`s correlation (1982) is modified in light of this model and the new correlation scales the present data and Cousins and Hewitt`s data very well. 19 refs., 8 figs., 3 tabs.

  7. Design and fabrication of a 40-MHz annular array transducer

    PubMed Central

    Ketterling, Jeffrey A.; Lizzi, Frederic L.; Aristizábal, Orlando; Turnbull, Daniel H.

    2006-01-01

    This paper investigates the feasibility of fabricating a 5-ring, focused annular array transducer operating at 40 MHz. The active piezoelectric material of the transducer was a 9-μm thick polyvinylidene fluoride (PVDF) film. One side of the PVDF was metallized with gold and forms the ground plane of the transducer. The array pattern of the transducer and electrical traces to each annulus were formed on a copper-clad polyimide film. The PVDF and polyimide were bonded with a thin layer of epoxy, pressed into a spherically curved shape, and then back filled with epoxy. A 5-ring transducer with equal area elements and 100 μm kerfs between annuli was fabricated and tested. The transducer had a total aperture of 6 mm and a geometric focus of 12 mm. The pulse/echo response from a quartz plate located at the geometric focus, two-way insertion loss (IL), complex impedance, electrical cross-talk, and lateral beamwidth were all measured for each annulus. The complex impedance data from each element were used to perform electrical matching and the measurements were repeated. After impedance matching, fc ≈ 36 MHz and BWs ranged from 31 to 39%. The ILs for the matched annuli ranged from −28 to −38 dB. PMID:16060516

  8. HAMLET forms annular oligomers when deposited with phospholipid monolayers.

    PubMed

    Baumann, Anne; Gjerde, Anja Underhaug; Ying, Ming; Svanborg, Catharina; Holmsen, Holm; Glomm, Wilhelm R; Martinez, Aurora; Halskau, Oyvind

    2012-04-20

    Recently, the anticancer activity of human α-lactalbumin made lethal to tumor cells (HAMLET) has been linked to its increased membrane affinity in vitro, at neutral pH, and ability to cause leakage relative to the inactive native bovine α-lactalbumin (BLA) protein. In this study, atomic force microscopy resolved membrane distortions and annular oligomers (AOs) produced by HAMLET when deposited at neutral pH on mica together with a negatively charged lipid monolayer. BLA, BAMLET (HAMLET's bovine counterpart) and membrane-binding Peptide C, corresponding to BLA residues 75-100, also form AO-like structures under these conditions but at higher subphase concentrations than HAMLET. The N-terminal Peptide A, which binds to membranes at acidic but not at neutral pH, did not form AOs. This suggests a correlation between the capacity of the proteins/peptides to integrate into the membrane at neutral pH-as observed by liposome content leakage and circular dichroism experiments-and the formation of AOs, albeit at higher concentrations. Formation of AOs, which might be important to HAMLET's tumor toxic action, appears related to the increased tendency of the protein to populate intermediately folded states compared to the native protein, the formation of which is promoted by, but not uniquely dependent on, the oleic acid molecules associated with HAMLET.

  9. Modeling and analysis of thermoacoustic instabilities in an annular combustor

    NASA Astrophysics Data System (ADS)

    Murthy, Sandeep; Sayadi, Taraneh; Le Chenadec, Vincent; Schmid, Peter

    2015-11-01

    A simplified model is introduced to study thermo-acoustic instabilities in axisymmetric combustion chambers. Such instabilities can be triggered when correlations between heat-release and pressure oscillations exist, leading to undesirable effects. Gas turbine designs typically consist of a periodic assembly of N identical units; as evidenced by documented studies, the coupling across sectors may give rise to unstable modes, which are the highlight of this study. In the proposed model, the governing equations are linearized in the acoustic limit, with each burner modeled as a one-dimensional system, featuring acoustic damping and a compact heat source. The coupling between the burners is accounted for by solving the two-dimensional wave equation over an annular region, perpendicular to the burners, representing the chamber's geometry. The discretization of these equations results in a set of coupled delay-differential equations, that depends on a finite set of parameters. The system's periodicity is leveraged using a recently developed root-of-unity formalism (Schmid et al., 2015). This results in a linear system, which is then subjected to modal and non-modal analysis to explore the influence of the coupled behavior of the burners on the system's stability and receptivity.

  10. DEP thermal convection in annular geometry under microgravity conditions

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Harunori; Crumeyrolle, Olivier; Mutabazi, Innocent

    2012-11-01

    Thermal convection driven by the dielectrophoretic force is investigated in annular geometry in microgravity environments. A radial heating and a radial alternating electric field are imposed on a dielectric fluid layer filling the gap of two concentric infinite-length cylinders. The resulting dielectric force field is regarded as spatially varying radial gravity that can develop thermal convection. The linear stability problem of a purely conductive basic state is solved by a spectral-collocation method for both axisymmetric and non-axisymmetric disturbances. A stationary non-axisymmetric mode becomes first unstable at a critical Rayleigh number to develop convection. The stability boundary shows asymmetry with respect to heating direction. For an outward heating the critical value approaches that of the Rayleigh-Bénard problem (1708) as the gap size decreases, while it converges to larger values in the narrow gap limit. For an inward heating the instability occurs only when the gap is narrower than a certain value. The critical number diverges with increasing the gap size. Instability mechanism is examined from energetic viewpoints. The feedback of electric field to temperature disturbances is found to stabilize the conductive state for narrow gaps. This work has been partly supported by the CNES, the CNRS and the FEDER.

  11. Casimir effect for a semitransparent wedge and an annular piston

    SciTech Connect

    Milton, Kimball A.; Wagner, Jef; Kirsten, Klaus

    2009-12-15

    We consider the Casimir energy due to a massless scalar field in a geometry of an infinite wedge closed by a Dirichlet circular cylinder, where the wedge is formed by {delta}-function potentials, so-called semitransparent boundaries. A finite expression for the Casimir energy corresponding to the arc and the presence of both semitransparent potentials is obtained, from which the torque on the sidewalls can be derived. The most interesting part of the calculation is the nontrivial nature of the angular mode functions. Numerical results are obtained which are closely analogous to those recently found for a magnetodielectric wedge, with the same speed of light on both sides of the wedge boundaries. Alternative methods are developed for annular regions with radial semitransparent potentials, based on reduced Green's functions for the angular dependence, which allows calculations using the multiple-scattering formalism. Numerical results corresponding to the torque on the radial plates are likewise computed, which generalize those for the wedge geometry. Generally useful formulas for calculating Casimir energies in separable geometries are derived.

  12. Casimir effect for a semitransparent wedge and an annular piston

    NASA Astrophysics Data System (ADS)

    Milton, Kimball A.; Wagner, Jef; Kirsten, Klaus

    2009-12-01

    We consider the Casimir energy due to a massless scalar field in a geometry of an infinite wedge closed by a Dirichlet circular cylinder, where the wedge is formed by δ-function potentials, so-called semitransparent boundaries. A finite expression for the Casimir energy corresponding to the arc and the presence of both semitransparent potentials is obtained, from which the torque on the sidewalls can be derived. The most interesting part of the calculation is the nontrivial nature of the angular mode functions. Numerical results are obtained which are closely analogous to those recently found for a magnetodielectric wedge, with the same speed of light on both sides of the wedge boundaries. Alternative methods are developed for annular regions with radial semitransparent potentials, based on reduced Green’s functions for the angular dependence, which allows calculations using the multiple-scattering formalism. Numerical results corresponding to the torque on the radial plates are likewise computed, which generalize those for the wedge geometry. Generally useful formulas for calculating Casimir energies in separable geometries are derived.

  13. Current Density Measurements of an Annular-Geometry Ion Engine

    NASA Technical Reports Server (NTRS)

    Shastry, Rohit; Patterson, Michael J.; Herman, Daniel A.; Foster, John E.

    2012-01-01

    The concept of the annular-geometry ion engine, or AGI-Engine, has been shown to have many potential benefits when scaling electric propulsion technologies to higher power. However, the necessary asymmetric location of the discharge cathode away from thruster centerline could potentially lead to non-uniformities in the discharge not present in conventional geometry ion thrusters. In an effort to characterize the degree of this potential non-uniformity, a number of current density measurements were taken on a breadboard AGI-Engine. Fourteen button probes were used to measure the ion current density of the discharge along a perforated electrode that replaced the ion optics during conditions of simulated beam extraction. Three Faraday probes spaced apart in the vertical direction were also used in a separate test to interrogate the plume of the AGI-Engine during true beam extraction. It was determined that both the discharge and the plume of the AGI-Engine are highly uniform, with variations under most conditions limited to +/-10% of the average current density in the discharge and +/-5% of the average current density in the plume. Beam flatness parameter measured 30 mm from the ion optics ranged from 0.85 - 0.95, and overall uniformity was shown to generally increase with increasing discharge and beam currents. These measurements indicate that the plasma is highly uniform despite the asymmetric location of the discharge cathode.

  14. Pollution technology program, can-annular combustor engines

    NASA Technical Reports Server (NTRS)

    Roberts, R.; Fiorentino, A. J.; Greene, W.

    1976-01-01

    A Pollution Reduction Technology Program to develop and demonstrate the combustor technology necessary to reduce exhaust emissions for aircraft engines using can-annular combustors is described. The program consisted of design, fabrication, experimental rig testing and assessment of results and was conducted in three program elements. The combustor configurations of each program element represented increasing potential for meeting the 1979 Environmental Protection Agency (EPA) emission standards, while also representing increasing complexity and difficulty of development and adaptation to an operational engine. Experimental test rig results indicate that significant reductions were made to the emission levels of the baseline JT8D-17 combustor by concepts in all three program elements. One of the Element I single-stage combustors reduced carbon monoxide to a level near, and total unburned hydrocarbons (THC) and smoke to levels below the 1979 EPA standards with little or no improvement in oxides of nitrogen. The Element II two-stage advanced Vorbix (vortex burning and mixing) concept met the standard for THC and achieved significant reductions in CO and NOx relative to the baseline. Although the Element III prevaporized-premixed concept reduced high power NOx below the Element II results, there was no improvement to the integrated EPA parameter relative to the Vorbix combustor.

  15. DoE Early Career Research Program: Final Report: Model-Independent Dark-Matter Searches at the ATLAS Experiment and Applications of Many-core Computing to High Energy Physics

    SciTech Connect

    Farbin, Amir

    2015-07-15

    This is the final report of for DoE Early Career Research Program Grant Titled "Model-Independent Dark-Matter Searches at the ATLAS Experiment and Applications of Many-core Computing to High Energy Physics".

  16. Heat Transfer Modeling of an Annular On-Line Spray Water Cooling Process for Electric-Resistance-Welded Steel Pipe

    PubMed Central

    Chen, Zejun; Han, Huiquan; Ren, Wei; Huang, Guangjie

    2015-01-01

    On-line spray water cooling (OSWC) of electric-resistance-welded (ERW) steel pipes can replace the conventional off-line heat treatment process and become an important and critical procedure. The OSWC process improves production efficiency, decreases costs, and enhances the mechanical properties of ERW steel pipe, especially the impact properties of the weld joint. In this paper, an annular OSWC process is investigated based on an experimental simulation platform that can obtain precise real-time measurements of the temperature of the pipe, the water pressure and flux, etc. The effects of the modes of annular spray water cooling and related cooling parameters on the mechanical properties of the pipe are investigated. The temperature evolutions of the inner and outer walls of the pipe are measured during the spray water cooling process, and the uniformity of mechanical properties along the circumferential and longitudinal directions is investigated. A heat transfer coefficient model of spray water cooling is developed based on measured temperature data in conjunction with simulation using the finite element method. Industrial tests prove the validity of the heat transfer model of a steel pipe undergoing spray water cooling. The research results can provide a basis for the industrial application of the OSWC process in the production of ERW steel pipes. PMID:26201073

  17. Heat Transfer Modeling of an Annular On-Line Spray Water Cooling Process for Electric-Resistance-Welded Steel Pipe.

    PubMed

    Chen, Zejun; Han, Huiquan; Ren, Wei; Huang, Guangjie

    2015-01-01

    On-line spray water cooling (OSWC) of electric-resistance-welded (ERW) steel pipes can replace the conventional off-line heat treatment process and become an important and critical procedure. The OSWC process improves production efficiency, decreases costs, and enhances the mechanical properties of ERW steel pipe, especially the impact properties of the weld joint. In this paper, an annular OSWC process is investigated based on an experimental simulation platform that can obtain precise real-time measurements of the temperature of the pipe, the water pressure and flux, etc. The effects of the modes of annular spray water cooling and related cooling parameters on the mechanical properties of the pipe are investigated. The temperature evolutions of the inner and outer walls of the pipe are measured during the spray water cooling process, and the uniformity of mechanical properties along the circumferential and longitudinal directions is investigated. A heat transfer coefficient model of spray water cooling is developed based on measured temperature data in conjunction with simulation using the finite element method. Industrial tests prove the validity of the heat transfer model of a steel pipe undergoing spray water cooling. The research results can provide a basis for the industrial application of the OSWC process in the production of ERW steel pipes.

  18. A Review of the Research: Common Core State Standards for Improving Rural Children's School Readiness

    ERIC Educational Resources Information Center

    Bailey, Lora Battle

    2014-01-01

    Although a plethora of research focuses on economically at-risk preschool children in general across the United States, little can be found that investigates methods for improving rural children's academic outcomes. This review of research is intended to provide a contextual understanding of the background and current conditions that exist…

  19. Application of Lateral Brain Research to the Employability Quotient of Core Black Youth: Implications for Occupational Futuring.

    ERIC Educational Resources Information Center

    Toldson, Ivory L.

    Lateral brain research can be used to develop an understanding and appreciation of the vocational and occupational significance of black expressive behavior manifested in some blacks. Historically, employers have placed primary emphasis on cognitive abilities--functions of the left side of the brain. Research has shown, however, that the right…

  20. Participatory Action Research and the Reconstruction of Teachers' Practical Thinking: Lesson Studies and Core Reflection. An Experience in Spain

    ERIC Educational Resources Information Center

    Perez, Angel I.; Soto, Encarnacion; Servan, M. Jose

    2010-01-01

    Following the thoughts and topics we have discussed and worked on for a very long time with Bridget Somekh, we would like to present the theoretical relationship between lesson studies, action research and practical knowledge in teacher education. Inspired by the pedagogical philosophy of lesson studies, participatory action research, and core…

  1. Core noise measurements from a small, general aviation turbofan engine

    NASA Astrophysics Data System (ADS)

    Reshotko, M.; Karchmer, A.

    1980-11-01

    As part of a program to investigate combustor and other core noises, simultaneous measurements of internal fluctuating pressure and far field noise were made with a JT15D turbofan engine. Acoustic waveguide probes, located in the engine at the combustor, at the turbine exit and in the core nozzle wall, were used to measure internal fluctuating pressures. Low frequency acoustic power determined at the core nozzle exit corresponds in level to the far field acoustic power at engine speeds below 65% of maximum, the approach condition. At engine speeds above 65% of maximum, the jet noise dominates in the far field, greatly exceeding that of the core. From coherence measurements, it is shown that the combustor is the dominant source of the low frequency core noise. The results obtained from the JT15D engine were compared with those obtained previously from a YF102 engine, both engines having reverse flow annular combustors and being in the same size class.

  2. Heating deep seated eccentrically located tumors with an annular phased array system: a comparative clinical study using two annular array operating configurations.

    PubMed

    Samulski, T V; Kapp, D S; Fessenden, P; Lohrbach, A

    1987-01-01

    Regional heating administered with an annular array to 12 patients with deep-seated advanced malignant disease eccentrically located in the lower abdomen and pelvis is compared based on the annular array operating configuration. One configuration (4 quadrants active) delivers radiofrequency power with relative uniformity throughout the patient cross-section. The other (2 quadrants active) allows the radiofrequency power deposition to be shifted preferentially into the eccentrically located treatment volume. Phantom measurements have been made to demonstrate the redistribution of radiofrequency power that results when the annular array is operated in these respective configurations. Systemic responses (i.e. oral temperature rise, changes in blood pressure, and heart rate) to these regional hyperthermia applications are compared and are not significantly different with respect to these heating configurations. Temperature data obtained during treatment sessions using these two annular array operating configurations are analyzed based on the fraction of measured tumor and normal tissue temperatures exceeding or equal to a given index temperature. Although the two quadrant configuration is more efficient in delivering power to the treatment volume, this analysis does not indicate a significant gain in therapeutic heating as a result of this preferential power deposition. Treatment tolerance and heterogeneity with respect to tissue type and blood flow remained the dominant limiting factors with regard to temperatures achieved.

  3. Development, implementation and assessment of specific, two-fluid closure laws for inverted-annular film-boiling

    SciTech Connect

    Cachard, F. de

    1995-09-01

    Inverted-Annular Film-Boiling (IAFB) is one of the post-burnout heat transfer modes taking place during the reflooding phase of the loss-of-coolant accident, when the liquid at the quench front is subcooled. Under IAFB conditions, a continuous, liquid core is separated from the wall by a superheated vapour film. the heat transfer rate in IAFB is influenced by the flooding rate, liquid subcooling, pressure, and the wall geometry and temperature. These influences can be accounted by a two-fluid model with physically sound closure laws for mass, momentum and heat transfers between the wall, the vapour film, the vapour-liquid interface, and the liquid core. Such closure laws have been developed and adjusted using IAFB-relevant experimental results, including heat flux, wall temperature and void fraction data. The model is extensively assessed against data from three independent sources. A total of 46 experiments have been analyzed. The overall predictions are good. The IAFB-specific closure laws proposed have also intrinsic value, and may be used in other two-fluid models. They should allow to improve the description of post-dryout, low quality heat transfer by the safety codes.

  4. Design and fabrication of sub-wavelength annular apertures for femtosecond laser machining

    NASA Astrophysics Data System (ADS)

    Hsu, Kuan-Yu; Tung, Yen-Chun; Chung, Ming-Han; Lee, Chih-Kung

    2015-03-01

    Many research teams have begun pursuing optical micromachining technology in recent years due to its associated noncontact and fast speed characteristics. However, the focal spot sizes and the depth of focus (DOF) strongly influenced the design requirements of the micromachining system. The focal spot size determines the minimum features can be fabricated, which is inversely proportional to the DOF. That is, smaller focal spot size led to shorter DOF. However, the DOF of the emitted visible or near-infrared light beam is typically limited to tens of nanometers for traditional optic system. The disadvantages of using nanosecond laser for micromachining such as burrs formation and surface roughness were found to further influence the accuracy of machined surfaces. To alleviate all of the above-mentioned problems, sub-wavelength annular aperture (SAA) illuminated with 780 nm femtosecond laser were integrated to develop the new laser micromachining system presented in this paper. We first optimized the parameters for high transmittance associated with the SAA structure for the 780 nm femtosecond laser used by adopting the finite difference time domain simulations method. A lateral microscope was modified from a traditional microscope to facilitate the measurement of the emitted light beam optical energy distribution. To verify the newly developed system performance the femtosecond laser was used to illuminate the SAA fabricated on the metallic film to produce the Bessel light beam so as to perform micromachining and process on silicon, PCB board and glass. Experimental results were found to match the original system design goals reasonably well.

  5. Solar cycle modulation of the Southern Annular mode -Simulation with the MRI-chemistry-climate model-

    NASA Astrophysics Data System (ADS)

    Kuroda, Y.; Shibata, K.

    2005-12-01

    Observation indicates that the 11-year solar cycle modulates the characteristics of the October/November mean Southern Annular Mode (SAM) [Kuroda and Kodera, 2005]. In fact, signal of the SAM tends to extend toward the upper stratosphere during late winter and the activity below lower stratosphere lasts until following summer in the high solar (HS) years. However accumulation and accuracy of observation is not good enough to examine the mechanism. To overcome this difficulty, we had examined this effect through simulation of the Meteorological-Research-Institute (MRI) chemistry climate model. 20-year integrations of the model was performed for an enhanced ultraviolet (UV) radiation corresponding to the HS years and moderate UV corresponding to the low solar (LS) years, respectively. Larger extension of the signal toward the upper stratosphere and longer duration of the signal was found in a HS experiment, whereas there was not in LS one. Analysis shows that the longer duration of signal in HS run was originated from lower stratospheric ozone which was transported from upper stratosphere through higher-extended wave driving toward the upper stratosphere. These results were almost consistent with that observed.

  6. Synchronous response modelling and control of an annular momentum control device

    NASA Technical Reports Server (NTRS)

    Hockney, Richard; Johnson, Bruce G.; Misovec, Kathleen

    1988-01-01

    Research on the synchronous response modelling and control of an advanced Annular Momentun Control Device (AMCD) used to control the attitude of a spacecraft is described. For the flexible rotor AMCD, two sources of synchronous vibrations were identified. One source, which corresponds to the mass unbalance problem of rigid rotors suspended in conventional bearings, is caused by measurement errors of the rotor center of mass position. The other sources of synchronous vibrations is misalignment between the hub and flywheel masses of the AMCD. Four different control algorithms were examined. These were lead-lag compensators that mimic conventional bearing dynamics, tracking notch filters used in the feedback loop, tracking differential-notch filters, and model-based compensators. The tracking differential-notch filters were shown to have a number of advantages over more conventional approaches for both rigid-body rotor applications and flexible rotor applications such as the AMCD. Hardware implementation schemes for the tracking differential-notch filter were investigated. A simple design was developed that can be implemented with analog multipliers and low bandwidth, digital hardware.

  7. Rotating annular chromatograph for continuous metal separations and recovery

    SciTech Connect

    Begovich, J.M.; Sisson, W.G.

    1981-01-01

    Multicomponent liquid chromatographic separations have been achieved by using a slowly rotating annular bed of sorbent material. By continuously introducing the feed material to be separated at a stationary point at the top of the bed and eluent everywhere else around the annulus, elution chromatography occurs. The rotation of the sorbent bed causes the separated components to appear as helical bands, each of which has a characteristic, stationary exit point; hence, the separation process is truly continuous. The concept has been developed primarily on a 279-mm-diam by 0.6-m-long device with a 12.7-mm-wide annulus. The effect of annulus width and diameter has recently been studied using the same device with a 50.8-mm-wide annulus and another 0.6-m-long chromatograph with an 89-mm diameter and annulus widths of 6.4, 12.7, and 22.2 mm. These columns have been constructed of Plexiglas and typically operate at a gauge pressure of 175 kPa. To further study the effect of size and pressure, a new 445-mm-diam by 1-m-long column with a 31.8-mm-wide annulus has been fabricated. Its metal construction allows preparative-scale operation with a wide variety of liquids at pressures to 1.3 MPa. Three metal recovery systems have been explored: (1) separation of iron and aluminum in ammonium sulfate-sulfuric acid solutions; (2) separation of hafnium from zirconium in sulfuric acid solutions; and (3) the separation of copper, nickel, and cobalt in ammonium carbonate solutions. This last system simulates the leach liquor of the Caron process for recovering nickel and cobalt from laterite ores. It has been studied, using similar conditions, on each of the chromatographs, and the results demonstrate the effect of column dimensions on the quality and quantity of the separation. 8 figures, 1 table.

  8. Calculated Neutron and Gamma-ray Spectra across the Prismatic Very High Temperature Reactor Core

    SciTech Connect

    James W. Sterbentz

    2008-05-01

    Neutron and gamma-ray flux spectra are calculated using the MCNP5 computer code and a one-sixth core model of a prismatic Very High Temperature Reactor based on the General Atomics Gas Turbine-Modular Helium Reactor. Spectra are calculated in the five inner reflector graphite block rings, three annular active core fuel rings, three outer graphite reflector block rings, and the core barrel. The neutron spectra are block and fuel pin averages and are calculated as a function of temperature and burnup. Also provided are the total, fast, and thermal radial profile fluxes and core barrel dpa rates.

  9. 24. A CORE WORKER DISPLAYS THE CORE BOX AND CORES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. A CORE WORKER DISPLAYS THE CORE BOX AND CORES FOR A BRASS GATE VALVE BODY MADE ON A CORE BOX, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  10. Place-based research project design for 10-week REU and two-week "mini-REU" internships using lake sediment cores

    NASA Astrophysics Data System (ADS)

    Myrbo, A.; Howes, T.; Thompson, R.; Drake, C.; Woods, P.; Schuldt, N.; Borkholder, B.; Marty, J.; Lafrancois, T.; Pellerin, H.

    2012-12-01

    Lake sediment cores provide scalable, interdisciplinary research projects that are well suited for summer internships such as the NSF-REU (Research Experience for Undergraduates). Short paleorecords (100-500 years or about a meter of core) are easy to collect and are tractable in terms of sample numbers (Myrbo et al. 2011). Many students find it compelling to reconstruct the recent past; choosing sites with cultural or historical significance is another way to make research seem more relevant. We present the results and experiences of designing two- and ten-week individual, group, and team research projects. Each of these projects contributes to the findings of a collaborative inquiry by the Fond du Lac Band of Lake Superior Chippewa (FDL) and the University of Minnesota (UMN). Research questions are determined and framed by FDL Resource Management, and student projects are supported and advised by both FDL and UMN scientists. The research is focused on the past environmental conditions of on- and off-Reservation wild rice lakes and the surrounding landscapes and people, and includes the study of biological and chemical proxies as well as historical records. Over the past three years, this approach has enabled diverse groups of students to conduct authentic and original basic research that also has applications to management and planning issues for Tribal resource managers, and to develop skills that are portable to other management and academic settings. These compelling "short" time scale projects can serve as a gateway for students to further pursue science including longer term paleorecords, climate change research, other disciplines in ecology, water resources, geography, archeology, and geology, as well as humanities research areas such as history and landscape architecture. An overarching goal is to help students understand current environmental change in the context of long-term changes, pre-industrial human land use, and accelerated Anthropocene impacts

  11. Collaborative Observation and Research (CORE) Watersheds: new strategies for tracking the regional effects of climate change on complex systems

    NASA Astrophysics Data System (ADS)

    Murdoch, P. S.

    2007-12-01

    The past 30 years of environmental research have shown that our world is not made up of discrete components acting independently, but rather of a mosaic of complex relations among air, land, water, living resources, and human activities. Recent warming of the climate is having a significant effect on the functioning of those systems. A national imperative is developing to quickly establish local, regional, and national systems for anticipating environmental degradation from a changing climate and developing cost-effective adaptation or mitigation strategies. In these circumstances, the debate over research versus monitoring becomes moot--there is a clear need for the integrated application of both across a range of temporal and spatial scales. A national framework that effectively addresses the multiple scales and complex multi-disciplinary processes of climate change is being assembled largely from existing programs through collaboration among Federal, State, local, and NGO organizations. The result will be an observation and research network capable of interpreting complex environmental changes at a range of spatial and temporal scales, but at less cost than if the network were funded as an independent initiative. A pilot implementation of the collaborative framework in the Delaware River Basin yielded multi-scale assessments of carbon storage and flux, and the effects of forest fragmentation and soil calcium depletion on ecosystem function. A prototype of a national climate-effects observation and research network linking research watersheds, regional surveys, remote sensing, and ecosystem modeling is being initiated in the Yukon River Basin where carbon flux associated with permafrost thaw could accelerate global warming.

  12. The Current Status of the Space Station Biological Research Project: a Core Facility Enabling Multi-Generational Studies under Slectable Gravity Levels

    NASA Astrophysics Data System (ADS)

    Santos, O.

    2002-01-01

    The Space Station Biological Research Project (SSBRP) has developed a new plan which greatly reduces the development costs required to complete the facility. This new plan retains core capabilities while allowing for future growth. The most important piece of equipment required for quality biological research, the 2.5 meter diameter centrifuge capable of accommodating research specimen habitats at simulated gravity levels ranging from microgravity to 2.0 g, is being developed by NASDA, the Japanese space agency, for the SSBRP. This is scheduled for flight to the ISS in 2007. The project is also developing a multi-purpose incubator, an automated cell culture unit, and two microgravity habitat holding racks, currently scheduled for launch in 2005. In addition the Canadian Space Agency is developing for the project an insect habitat, which houses Drosophila melanogaster, and provides an internal centrifuge for 1 g controls. NASDA is also developing for the project a glovebox for the contained manipulation and analysis of biological specimens, scheduled for launch in 2006. This core facility will allow for experimentation on small plants (Arabidopsis species), nematode worms (C. elegans), fruit flies (Drosophila melanogaster), and a variety of microorganisms, bacteria, yeast, and mammalian cells. We propose a plan for early utilization which focuses on surveys of changes in gene expression and protein structure due to the space flight environment. In the future, the project is looking to continue development of a rodent habitat and a plant habitat that can be accommodated on the 2.5 meter centrifuge. By utilizing the early phases of the ISS to broadly answer what changes occur at the genetic and protein level of cells and organisms exposed to the ISS low earth orbit environment, we can generate interest for future experiments when the ISS capabilities allow for direct manipulation and intervention of experiments. The ISS continues to hold promise for high quality, long

  13. Convective heat transfer to CO{sub 2} at a supercritical pressure flowing vertically upward in tubes and an annular channel

    SciTech Connect

    Bae, Yoon-Yeong; Kim, Hwan-Yeol

    2009-01-15

    The Super-Critical Water-Cooled Reactor (SCWR) has been chosen by the Generation IV International Forum as one of the candidates for the next generation nuclear reactors. Heat transfer to water from a fuel assembly may deteriorate at certain supercritical pressure flow conditions and its estimation at degraded conditions as well as in normal conditions is very important to the design of a safe and reliable reactor core. Extensive experiments on a heat transfer to a vertically upward flowing CO{sub 2} at a supercritical pressure in tubes and an annular channel have been performed. The geometries of the test sections include tubes of an internal diameter (ID) of 4.4 and 9.0 mm and an annular channel (8 x 10 mm). The heat transfer coefficient (HTC) and Nusselt numbers were derived from the inner wall temperature converted by using the outer wall temperature measured by adhesive K-type thermocouples and a direct (tube) or indirect (annular channel) electric heating power. From the test results, a correlation, which covers both a deteriorated and a normal heat transfer regime, was developed. The developed correlation takes different forms in each interval divided by the value of parameter Bu. The parameter Bu (referred to as Bu hereafter), a function of the Grashof number, the Reynolds number and the Prandtl number, was introduced since it is known to be a controlling factor for the occurrence of a heat transfer deterioration due to a buoyancy effect. The developed correlation predicted the HTCs for water and HCFC-22 fairly well. (author)

  14. Transverse bed slope effects in an annular flume

    NASA Astrophysics Data System (ADS)

    Baar, Anne; Kleinhans, Maarten; de Smit, Jaco; Uijttewaal, Wim

    2016-04-01

    Large scale morphology, in particular bar dimensions and bifurcation dynamics, are greatly affected by the deflection of sediment transport on transverse bed slopes due to gravity and by helical flows. However, existing transverse bed slope predictors are based on a small set of experiments with a minor range of flow conditions and sediment sizes, and do not account for the presence of bedforms. In morphological modelling the deflection angle is therefore often calibrated on measured morphology. Our objective is to experimentally quantify the transverse slope effect for a large range of near-bed flow conditions and sediment sizes (0.17 - 4 mm) to test existing predictors, in order to improve morphological modelling of rivers and estuaries. We have conducted about 400 experiments in an annular flume, which functions as an infinitely long bended flume and therefore avoids boundary effects. Flow is generated by rotating the lid of the flume, while the intensity of the helical flow can be decreased by counterrotating the bottom of the flume. The equilibrium transverse slope that develops during the experiments is a balance between the transverse bed slope effect and the bed shear stress caused by the helical flow. We obtained sediment mobilities from no motion to sheet flow, ranging across bedload and suspended load. Resulting equilibrium transverse slopes show a clear trend with varying sediment mobilities and helical flow intensities that deviate from typical power relations with Shields number. As an end member we found transversely horizontal beds by counterrotation that partially cancelled the helical flow near the bed, which allows us to quantify helical flow. The large range in sediment mobilities caused different bed states from ripples and dunes to sheet flow that affect near-bed flow, which cause novel nonlinear relations between transverse slope and Shields number. In conclusion, our results show for a wide range of conditions and sediments that transverse

  15. Beyond the Cosmological: Numerical Scenarios underneath Ancient Annular Architectural Structures

    NASA Astrophysics Data System (ADS)

    Ranieri, M.

    2009-08-01

    ``Cecì est la regle du carré et du cercle. Pour toutes choses, la circonférence (tcheou) est en usage, et les figures circulaire et carrée sont employées. L'officier dit ta-tsiang (grand charpentier, titre du Tcheou-li) prend ses mesures. Le compass et le règle sont apprêtés. Tantot on rompt le carré et on fait un cercle. Tantot on brise le cercle et on fait un carré. Au milieu d'un carré, quand on fait un cercle, on appelle cette figure cercle-carré. Au milieu d'un cercle, quand on fait un carré, on appelle cette figure carré-cercle.'' (Tcheou-Pei-Souan-King, book one, trad. E.Biot, Journal Asiatique, Juin 1841 p. 614 Circles and squares, as geometrical representations of the cosmos, are frequent in ancient cultures, mainly with the earth represented by the square and the sky by the circle. Quite many are the circular or circle-and-square architectures of the past that are to be interpreted as related to the cosmologies of the cultures to which they belong. In this paper we focus on those relevant annular geometries (CQC) where the square inscribable into the external circumference in turn perfectly circumscribes the internal one. Beyond the possible cosmological significances, a CQC geometry bears underneath a strict numerical structure that can be put in relation to the length-units used by the builders. Results are presented of CAD (Computer Aided Drawing) analyses performed on the plans of ancient structures where the CQC geometry was suspected to exist. A large repertory of such structures has been found, from Nuragic Sardinia to Mesoamerica including Minoans, Greeks, Romans and others. In many cases the found length-units coincide with known ancient units. The large variety presented at CAC 2000 cannot be shown in this paper for reasons of space and only a smaller but significant selection is presented.

  16. A computational investigation of impulsive and pulsed starting annular jets

    NASA Astrophysics Data System (ADS)

    Abdel-Raouf, Emad Mohamed Refaat

    2011-12-01

    A computational study is carried out on low Reynolds number impulsive and pulsating annular jets. This work is inspired by the biological flow of marine life that uses jet propulsion for self maneuver. Marine life such as squids and jellyfish propel themselves by discharging a water jet followed by a refilling phase. The discharging portion is a starting jet, i.e. the releasing of a moving fluid into a quiescent fluid, while the refilling phase can be viewed as an inflow jet. The combined jets will be called fully oscillating jets. Although fully oscillating jets have been indirectly examined experimentally, they have never been studied computationally. This dissertation is divided into three investigations that examine the starting jet, inflow jet, and fully oscillating jet based on the resultant force (i.e. either thrust or suction force) at the annulus exit plane, jet efficiency, and vortex dynamics. Furthermore, each of the following three performance criterion is examined under various velocity imposed boundaries (i.e. impulsive, unit pulsed, and sinusoidal pulsed jets), ambient pressure, and blocking ratios. An axisymmetric, incompressible and unsteady Navier Stokes numerical model was used to implement the analysis. The model was validated against theoretical and experimental results, where both result types bounded the computational results of this endeavor. In addition, numerical verification was carried out on each of the three investigations ensuring grid and time independent results. Several substantial outcomes were drawn from the results of the three investigations. The numerical results confirmed previously published experimental data regarding the universal dimensionless time scale (i.e. vortex formation number) of optimal vortex ring development triggered by starting jets. Moreover, the computational results showed evidence that the vortex formation number was not affected by ambient pressure nor blocking ratio. The computational results also

  17. Properties of Subsurface Soil Cores from Four Geologic Provinces Surrounding Mars Desert Research Station, Utah: Characterizing Analog Martian Soil in a Human Exploration Scenario

    NASA Technical Reports Server (NTRS)

    Stoker, C. R.; Clarke, J. D. A.; Direito, S.; Foing, B.

    2011-01-01

    The DOMEX program is a NASA-MMAMA funded project featuring simulations of human crews on Mars focused on science activities that involve collecting samples from the subsurface using both manual and robotic equipment methods and analyzing them in the field and post mission. A crew simulating a human mission to Mars performed activities focused on subsurface science for 2 weeks in November 2009 at Mars Desert Research Station near Hanksville, Utah --an important chemical and morphological Mars analog site. Activities performed included 1) survey of the area to identify geologic provinces, 2) obtaining soil and rock samples from each province and characterizing their mineralogy, chemistry, and biology; 3) site selection and reconnaissance for a future drilling mission; 4) deployment and testing of Mars Underground Mole, a percussive robotic soil sampling device; and 5) recording and analyzing how crew time was used to accomplish these tasks. This paper summarizes results from analysis of soil cores

  18. Overview of magnetic bearing control and linearization approaches for annular magnetically suspended devices

    NASA Technical Reports Server (NTRS)

    Groom, N. J.

    1984-01-01

    An overview of magnetic bearing control and linearization approaches which have been considered for annular magnetically suspended devices is presented. These devices include the Annular Momentum Control Device and the Annular Suspension and Pointing System. Two approaches were investigated for controlling the magnetic actuator. One approach involves controlling the upper and lower electromagnets differentially about a bias flux. The bias flux can either be supplied by permanent magnets in the magnetic circuit or by bias currents. In the other approach, either the upper electromagnet or the lower electromagnet is controlled depending on the direction of force required. One advantage of the bias flux is that for small gap perturbations about a fixed operating point, the force-current characteristic is linear. Linearization approaches investigated for individual element control include an analog solution of the nonlinear electromagnet force equation and a microprocessor-based table lookup method.

  19. Analytic wave solution with helicon and Trivelpiece-Gould modes in an annular plasma

    NASA Astrophysics Data System (ADS)

    Carlsson, Johan; Pavarin, Daniele; Walker, Mitchell

    2009-11-01

    Helicon sources in an annular configuration have applications for plasma thrusters. The theory of Klozenberg et al. [J. P. Klozenberg B. McNamara and P. C. Thonemann, J. Fluid Mech. 21 (1965) 545-563] for the propagation and absorption of helicon and Trivelpiece-Gould modes in a cylindrical plasma has been generalized for annular plasmas. Analytic solutions are found also in the annular case, but in the presence of both helicon and Trivelpiece-Gould modes, a heterogeneous linear system of equations must be solved to match the plasma and inner and outer vacuum solutions. The linear system can be ill-conditioned or even exactly singular, leading to a dispersion relation with a discrete set of discontinuities. The coefficients for the analytic solution are calculated by solving the linear system with singular-value decomposition.

  20. Analytic wave solution with helicon and Trivelpiece-Gould modes in an annular plasma

    SciTech Connect

    Carlsson, Johan; Pavarin, Daniele; Walker, Mitchell

    2009-11-26

    Helicon sources in an annular configuration have applications for plasma thrusters. The theory of Klozenberg et al.[J. P. Klozenberg B. McNamara and P. C. Thonemann, J. Fluid Mech. 21(1965) 545-563] for the propagation and absorption of helicon and Trivelpiece-Gould modes in a cylindrical plasma has been generalized for annular plasmas. Analytic solutions are found also in the annular case, but in the presence of both helicon and Trivelpiece-Gould modes, a heterogeneous linear system of equations must be solved to match the plasma and inner and outer vacuum solutions. The linear system can be ill-conditioned or even exactly singular, leading to a dispersion relation with a discrete set of discontinuities. The coefficients for the analytic solution are calculated by solving the linear system with singular-value decomposition.

  1. Hybrid multiphase CFD simulation for liquid-liquid interfacial area prediction in annular centrifugal contactors

    SciTech Connect

    Wardle, K.E.

    2013-07-01

    Liquid-liquid contacting equipment used in solvent extraction processes has the dual purpose of mixing and separating two immiscible fluids. Consequently, such devices inherently encompass a wide variety of multiphase flow regimes. A hybrid multiphase computational fluid dynamics (CFD) solver which combines the Eulerian multi-fluid method with VOF (volume of fluid) sharp interface capturing has been developed for application to annular centrifugal contactors. This solver has been extended to enable prediction of mean droplet size and liquid-liquid interfacial area through a single moment population balance method. Simulations of liquid-liquid mixing in a simplified geometry and a model annular centrifugal contactor are reported with droplet breakup/coalescence models being calibrated versus available experimental data. Quantitative comparison is made for two different housing vane geometries and it is found that the predicted droplet size is significantly smaller for vane geometries which result in higher annular liquid holdup.

  2. The Annular Suspension and Pointing (ASP) system for space experiments and predicted pointing accuracies

    NASA Technical Reports Server (NTRS)

    Anderson, W. W.; Joshi, S. M.

    1975-01-01

    An annular suspension and pointing system consisting of pointing assemblies for coarse and vernier pointing is described. The first assembly is attached to a carrier spacecraft (e.g., the space shuttle) and consists of an azimuth gimbal and an elevation gimbal which provide 'coarse' pointing. The second or vernier pointing assembly is made up of magnetic actuators of suspension and fine pointing, roll motor segments, and an instrument or experiment mounting plate around which is attached a continuous annular rim similar to that used in the annular momentum control device. The rim provides appropriate magnetic circuits for the actuators and the roll motor segments for any instrument roll position. The results of a study to determine the pointing accuracy of the system in the presence of crew motion disturbances are presented. Typical 3 sigma worst-case errors are found to be of the order of 0.001 arc-second.

  3. An experimental technique for performing 3-D LDA measurements inside whirling annular seals

    NASA Technical Reports Server (NTRS)

    Morrison, Gerald L.; Johnson, Mark C.; Deotte, Robert E., Jr.; Thames, H. Davis, III.; Wiedner, Brian G.

    1992-01-01

    During the last several years, the Fluid Mechanics Division of the Turbomachinery Laboratory at Texas A&M University has developed a rather unique facility with the experimental capability for measuring the flow field inside journal bearings, labyrinth seals, and annular seals. The facility consists of a specially designed 3-D LDA system which is capable of measuring the instantaneous velocity vector within 0.2 mm of a wall while the laser beams are aligned almost perpendicular to the wall. This capability was required to measure the flow field inside journal bearings, labyrinth seals, and annular seals. A detailed description of this facility along with some representative results obtained for a whirling annular seal are presented.

  4. In-line type micropulse lidar with an annular beam: theoretical approach.

    PubMed

    Shiina, Tatsuo; Yoshida, Kei; Ito, Masafumi; Okamura, Yasuyuki

    2005-12-01

    An in-line type micropulse lidar (MPL) with an annular beam was designed and the transmitting and receiving characteristics were analyzed. Because the in-line MPL utilizes a common telescope for a transmitter and a receiver and the annular beam always overlaps with the receiver's field of view (FOV), it can measure near-range lidar echoes with a narrow FOV. The transmitting annular beam changes its shape to a nearly nondiffractive beam through propagation. It improves the spatial resolution of the lidar observation. The receiving characteristics showed the ideal lidar echo variation, which was inversely proportional to the square of the distance the beam propagated, even if it was in the near range. PMID:16353820

  5. Pressure drop in fully developed, turbulent, liquid-vapor annular flows in zero gravity

    NASA Technical Reports Server (NTRS)

    Sridhar, K. R.; Chao, B. T.; Soo, S. L.

    1992-01-01

    The prediction of frictional pressure drop in fully developed, turbulent, annular liquid-vapor flows in zero gravity using simulation experiments conducted on earth is described. The scheme extends the authors' earlier work on dispersed flows. The simulation experiments used two immiscible liquids of identical density, namely, water and n-butyl benzoate. Because of the lack of rigorous analytical models for turbulent, annular flows, the proposed scheme resorts to existing semiempirical correlations. Results based on two different correlations are presented and compared. Others may be used. It was shown that, for both dispersed and annular flow regimes, the predicted frictional pressure gradients in 0-g are lower than those in 1-g under otherwise identical conditions. The physical basis for this finding is given.

  6. Eosinophilic annular erythema: a subset of Wells' syndrome or a distinct entity?

    PubMed

    Howes, Renae; Girgis, Laila; Kossard, Steven

    2008-08-01

    A 52-year-old woman with a 6-year history of a persistent non-pruritic cutaneous annular eruption, forming polycyclic and arcuate plaques that commenced as erythematous papules and nodules, is presented. Lethargy and arthralgia were associated symptoms. We have followed this patient for the last 3 years, and during this period she has continued to have a florid annular eruption of unknown cause. Laboratory tests, including an eosinophil count, examination of stool samples for parasites, and a computed tomography scan of the chest, abdomen and pelvis, failed to detect any abnormalities. Skin biopsies demonstrated a superficial to deep cellular infiltrate consisting of numerous eosinophils, with lymphocytes and isolated neutrophils. Eosinophilic dust, flame figures and granulomatous inflammation were not seen. In addition, strands of mucin were present through the dermis, and prominent basal vacuolar change was evident at the dermoepidermal junction; these features may represent new findings that help define a distinct form of eosinophilic annular erythema. PMID:18638225

  7. Modelling Air and Water Two-Phase Annular Flow in a Small Horizontal Pipe

    NASA Astrophysics Data System (ADS)

    Yao, Jun; Yao, Yufeng; Arini, Antonino; McIiwain, Stuart; Gordon, Timothy

    2016-06-01

    Numerical simulation using computational fluid dynamics (CFD) has been carried out to study air and water two-phase flow in a small horizontal pipe of an inner diameter of 8.8mm, in order to investigate unsteady flow pattern transition behaviours and underlying physical mechanisms. The surface liquid film thickness distributions, determined by either wavy or full annular flow regime, are shown in reasonable good agreement with available experimental data. It was demonstrated that CFD simulation was able to predict wavy flow structures accurately using two-phase flow sub-models embedded in ANSYS-Fluent solver of Eulerian-Eulerian framework, together with a user defined function subroutine ANWAVER-UDF. The flow transient behaviours from bubbly to annular flow patterns and the liquid film distributions revealed the presence of gas/liquid interferences between air and water film interface. An increase of upper wall liquid film thickness along the pipe was observed for both wavy annular and full annular scenarios. It was found that the liquid wavy front can be further broken down to form the water moisture with liquid droplets penetrating upwards. There are discrepancies between CFD predictions and experimental data on the liquid film thickness determined at the bottom and the upper wall surfaces, and the obtained modelling information can be used to assist further 3D user defined function subroutine development, especially when CFD simulation becomes much more expense to model full 3D two-phase flow transient performance from a wavy annular to a fully developed annular type.

  8. Histological study of the annular ligament in the rabbitfish eye (Siganus sp.).

    PubMed

    Asli, Marziye; Mansoori, Forooghsadat; Sattari, Amir

    2012-01-01

    Rabbitfish is economically valuable teleost species which lives in shallow coastal waters. Two species of rabbit fish have been recognized in southern sea of Iran (Persian gulf) as namely Siganus sutor and Siganus javus. In the current study, in order to investigate the histology of the annular ligament of the S. javus' eye, the prepared sections of the eyes of twelve healthy specimens were studied under light microscope. The results revealed that annular ligament is a crescent shape structure which is situated between the scleral stroma anteriorly and the iris posteriorly. It contains a vascularized, amorphous and granular matrix with fibers of dense connective tissue; high glycogen content and melanin pigments. PMID:25653773

  9. Numerical model for combined conductive and radiative heat transfer in annular packed beds

    SciTech Connect

    Kamiuto, K.; Saito, S.; Ito, K. . Dept. of Production Systems Engineering)

    1993-06-01

    A numerical model is developed for quantitatively analyzing combined conductive and radiative heat transfer in concentric annular packed beds. A packed bed is considered to be a continuous medium for heat transfer, but the porosity distribution within a packed bed is taken into account. To examine the validity of the proposed model, combined conductive and radiative heat transfer through annular packed beds of cordierite or porcelain beads is analyzed numerically using finite differences under conditions corresponding to heat transfer experiments of these packed beds. The resultant temperature profiles and heat transfer characteristics are compared with the experimental results.

  10. Liquid–Liquid Mixing Studies in Annular Centrifugal Contactors Comparing Stationary Mixing Vane Options

    SciTech Connect

    Wardle, Kent E.

    2015-11-10

    Comparative studies of multiphase operation of annular centrifugal contactors showing the impact of housing stationary mixing vane configuration. A number of experimental results for several different mixing vane options are reported with selected measurements in a lab-scale 5 cm contactor and 12.5 cm engineering-scale unit. Fewer straight vanes give greater mixingzone hold-up compared to curved vanes. Quantitative comparison of droplet size distribution also showed a significant decrease in mean diameter for four straight vanes versus eight curved vanes. This set of measurements gives a compelling case for careful consideration of mixing vane geometry when evaluating hydraulic operation and extraction process efficiency of annular centrifugal contactors.

  11. On the visibility of very thin specimens in annular bright field scanning transmission electron microscopy

    SciTech Connect

    Phillips, P. J.; Klie, R. F.

    2013-07-15

    Annular bright field (ABF) scanning transmission electron microscopy (STEM) is emerging as an important observation mode for its ability to simultaneously image both heavy and light elements. However, recent results have demonstrated that in the limit of a very thin specimen (a few atomic layers), the ABF and high angle annular dark field (HAADF) signals cease to be intuitively related: a phenomenon which is generally irrelevant when imaging 'normal' specimens. ABF/HAADF STEM observations and multislice image simulations of two catalyst samples of differing atomic weights are presented; it is shown that the nature of the ABF signal is specimen dependent.

  12. Production and delivery of a fluid mixture to an annular volume of a wellbore

    DOEpatents

    Hermes, Robert E.; Bland, Ronald Gene; Foley, Ron Lee; Bloys, James B.; Gonzalez, Manuel E.; Daniel, John M.; Robinson, Ian M.; Carpenter, Robert B.

    2012-01-24

    The methods described herein generally relate to preparing and delivering a fluid mixture to a confined volume, specifically an annular volume located between two concentrically oriented casing strings within a hydrocarbon fluid producing well. The fluid mixtures disclosed herein are useful in controlling pressure in localized volumes. The fluid mixtures comprise at least one polymerizable monomer and at least one inhibitor. The processes and methods disclosed herein allow the fluid mixture to be stored, shipped and/or injected into localized volumes, for example, an annular volume defined by concentric well casing strings.

  13. Radially polarized annular beam generated through a second-harmonic-generation process.

    PubMed

    Sato, Shunichi; Kozawa, Yuichi

    2009-10-15

    A radially polarized beam with an annular intensity pattern was generated through a second-harmonic-generation process by focusing an azimuthally polarized Ti:sapphire pulsed laser beam to a c-cut beta-barium borate (BBO) crystal. The annular intensity pattern of the second-harmonic wave had a nearly sixfold symmetry as a result of the nonlinear susceptibility tensor of the BBO crystal. The width of the annulus was as narrow as less than 1/40th of its radius.

  14. Near-limit propagation of gaseous detonations in narrow annular channels

    NASA Astrophysics Data System (ADS)

    Gao, Y.; Ng, H. D.; Lee, J. H. S.

    2016-03-01

    New results on the near-limit behaviors of gaseous detonations in narrow annular channels are reported in this paper. Annular channels of widths 3.2 and 5.9 mm were made using circular inserts in a 50.8 mm-diameter external tube. The length of each annular channel was 1.8 m. Detonations were initiated in a steel driver tube where a small volume of a sensitive C2H2+ 2.5O2 mixture was injected to facilitate detonation initiation. A 2 m length of circular tube with a 50.8 mm diameter preceded the annular channel so that a steady Chapman-Jouguet (CJ) detonation was established prior to entering the annular channel. Four detonable mixtures of C2H2 {+} 2.5O2 {+} 85 % Ar, C2H2 {+} 2.5O2 {+} 70 % Ar, C3H8 {+} 5O2 , and CH4 {+} 2O2 were used in the present study. Photodiodes spaced 10 cm throughout the length of both the annular channel and circular tube were used to measure the detonation velocity. In addition, smoked foils were inserted into the annular channel to monitor the cellular structure of the detonation wave. The results show that, well within the detonability limits, the detonation wave propagates along the channel with a small local velocity fluctuation and an average global velocity can be deduced. The average detonation velocity has a small deficit of 5-15 % far from the limits and the velocity rapidly decreases to 0.7V_{CJ} -0.8V_{CJ} when the detonation propagates near the limit. Subsequently, the fluctuation of local velocity also increases as the decreasing initial pressure approaches the limit. In the two annular channels used in this work, no galloping detonations were observed for both the stable and unstable mixtures tested. The present study also confirms that single-headed spinning detonation occurs at the limit, as in a circular tube, rather than the up and down "zig zag" mode in a two-dimensional, rectangular channel.

  15. Computation of the flow field in an annular gas turbine combustor

    NASA Technical Reports Server (NTRS)

    Cline, Michael C.; Deur, John M.; Micklow, Gerald J.; Harper, Michael R.; Kundu, Krishna P.

    1993-01-01

    The KIVA-II code was modified to calculate the 3D flow field in a typical annular gas turbine combustor. The airblast fuel nozzle, cooling baffle, cooling slots, primary and dilution jets, and effusion cooling (bleed) pads were accounted for in this calculation. The turbulence and combustion were modeled using the k-epsilon model and laminar Arrhenius kinetics, respectively. The fuel was modeled as an evaporating liquid spray. The results illustrate the complicated flow fields present in such combustors. From the results obtained to date it appears that the modified KIVA-II code can be used to study the effects of different annular combustor designs and operating conditions.

  16. Histological study of the annular ligament in the rabbitfish eye (Siganus sp.).

    PubMed

    Asli, Marziye; Mansoori, Forooghsadat; Sattari, Amir

    2012-01-01

    Rabbitfish is economically valuable teleost species which lives in shallow coastal waters. Two species of rabbit fish have been recognized in southern sea of Iran (Persian gulf) as namely Siganus sutor and Siganus javus. In the current study, in order to investigate the histology of the annular ligament of the S. javus' eye, the prepared sections of the eyes of twelve healthy specimens were studied under light microscope. The results revealed that annular ligament is a crescent shape structure which is situated between the scleral stroma anteriorly and the iris posteriorly. It contains a vascularized, amorphous and granular matrix with fibers of dense connective tissue; high glycogen content and melanin pigments.

  17. Histological study of the annular ligament in the rabbitfish eye (Siganus sp.)

    PubMed Central

    Asli, Marziye; Mansoori, Forooghsadat; Sattari, Amir

    2012-01-01

    Rabbitfish is economically valuable teleost species which lives in shallow coastal waters. Two species of rabbit fish have been recognized in southern sea of Iran (Persian gulf) as namely Siganus sutor and Siganus javus. In the current study, in order to investigate the histology of the annular ligament of the S. javus’ eye, the prepared sections of the eyes of twelve healthy specimens were studied under light microscope. The results revealed that annular ligament is a crescent shape structure which is situated between the scleral stroma anteriorly and the iris posteriorly. It contains a vascularized, amorphous and granular matrix with fibers of dense connective tissue; high glycogen content and melanin pigments. PMID:25653773

  18. Annular Lichenoid Dermatitis of Youth: A Report of 2 Cases and a Review of the Literature.

    PubMed

    Vázquez-Osorio, I; González-Sabín, M; Gonzalvo-Rodríguez, P; Rodríguez-Díaz, E

    2016-01-01

    Annular lichenoid dermatitis of youth is a lichenoid dermatosis of unknown etiology. It mostly affects children and adolescents and has well-defined clinical and histological characteristics that permit a diagnosis. We present 2 new cases of annular lichenoid dermatitis of youth with classical clinical features in 2 girls, aged 2 and 4 years. The histologic findings, however, differed from those reported in the literature in that the lichenoid inflammatory infiltrate was located primarily at the top of the dermal papillae and not at the tips of the rete ridges. In both cases, the lesions regressed spontaneously without treatment.

  19. Liquid–liquid mixing studies in annular centrifugal contactors comparing stationary mixing vane options

    SciTech Connect

    Wardle, Kent E.

    2015-09-11

    Comparative studies of multiphase operation of an annular centrifugal contactor show the impact of housing stationary mixing vane configuration. A number of experimental results for several different mixing vane options are reported for operation of a 12.5 cm engineering-scale contactor unit. Fewer straight vanes give greater mixing-zone hold-up compared to curved vanes. Quantitative comparison of droplet size distribution also showed a significant decrease in mean diameter for four straight vanes versus eight curved vanes. This set of measurements gives a compelling case for careful consideration of mixing vane geometry when evaluating hydraulic operation and extraction process efficiency of annular centrifugal contactors.

  20. Core layering

    NASA Astrophysics Data System (ADS)

    Jacobson, S. A.; Rubie, D. C.; Hernlund, J. W.; Morbidelli, A.

    2015-12-01

    We have created a planetary accretion and differentiation model that self-consistently builds and evolves Earth's core. From this model, we show that the core grows stably stratified as the result of rising metal-silicate equilibration temperatures and pressures, which increases the concentrations of light element impurities into each newer core addition. This stable stratification would naturally resist convection and frustrate the onset of a geodynamo, however, late giant impacts could mechanically mix the distinct accreted core layers creating large homogenous regions. Within these regions, a geodynamo may operate. From this model, we interpret the difference between the planetary magnetic fields of Earth and Venus as a difference in giant impact histories. Our planetary accretion model is a numerical N-body integration of the Grand Tack scenario [1]—the most successful terrestrial planet formation model to date [2,3]. Then, we take the accretion histories of Earth-like and Venus-like planets from this model and post-process the growth of each terrestrial planet according to a well-tested planetary differentiation model [4,5]. This model fits Earth's mantle by modifying the oxygen content of the pre-cursor planetesimals and embryos as well as the conditions of metal-silicate equilibration. Other non-volatile major, minor and trace elements included in the model are assumed to be in CI chondrite proportions. The results from this model across many simulated terrestrial planet growth histories are robust. If the kinetic energy delivered by larger impacts is neglected, the core of each planet grows with a strong stable stratification that would significantly impede convection. However, if giant impact mixing is very efficient or if the impact history delivers large impacts late, than the stable stratification can be removed. [1] Walsh et al. Nature 475 (2011) [2] O'Brien et al. Icarus 223 (2014) [3] Jacobson & Morbidelli PTRSA 372 (2014) [4] Rubie et al. EPSL 301

  1. Thermal hydraulic analysis of the annular flow helium heater design

    SciTech Connect

    Chen, N.C.; Sanders, J.P.

    1982-05-01

    Oak Ridge National Laboratory has conducted Core Support Performance Test (CSPT) by use of an existing facility, Component Flow Test Loop (CFTL), as part of the High Temperature Gas-Cooled Reactor (HTGR) application program. A major objective of the CSPT is to study accelerated corrosion of the core graphite support structure in helium at reactor conditions. Concentration of impurities will be adjusted so that a 6-month test represents the 30-year reactor life. Thermal hydraulic and structural integrity of the graphite specimen, among other things, will be studied at high pressure of 7.24 MPa (1050 psi) and high temperature of 1000/sup 0/C (1832/sup 0/F) in a test vessel. To achieve the required high temperature at the test section, a heater bundle has to be specially designed and properly manufactured. This report presents performance characteristics of the heater that were determined from an analysis based on this design.

  2. Causal Chains Arising from Climate Change in Mountain Regions: the Core Program of the Mountain Research Initiative

    NASA Astrophysics Data System (ADS)

    Greenwood, G. B.

    2014-12-01

    Mountains are a widespread terrestrial feature, covering from 12 to 24 percent of the world's terrestrial surface, depending of the definition. Topographic relief is central to the definition of mountains, to the benefits and costs accruing to society and to the cascade of changes expected from climate change. Mountains capture and store water, particularly important in arid regions and in all areas for energy production. In temperate and boreal regions, mountains have a great range in population densities, from empty to urban, while tropical mountains are often densely settled and farmed. Mountain regions contain a wide range of habitats, important for biodiversity, and for primary, secondary and tertiary sectors of the economy. Climate change interacts with this relief and consequent diversity. Elevation itself may accentuate warming (elevationi dependent warming) in some mountain regions. Even average warming starts complex chains of causality that reverberate through the diverse social ecological mountain systems affecting both the highlands and adjacent lowlands. A single feature of climate change such as higher snow lines affect the climate through albedo, the water cycle through changes in timing of release , water quality through the weathering of newly exposed material, geomorphology through enhanced erosion, plant communities through changes in climatic water balance, and animal and human communities through changes in habitat conditions and resource availabilities. Understanding these causal changes presents a particular interdisciplinary challenge to researchers, from assessing the existence and magnitude of elevation dependent warming and monitoring the full suite of changes within the social ecological system to climate change, to understanding how social ecological systems respond through individual and institutional behavior with repercussions on the long-term sustainability of these systems.

  3. Massive Magnetic Core

    NASA Technical Reports Server (NTRS)

    1964-01-01

    The massive magnetic core of the Space Radiation Effects Laboratory's Synchrocyclotron at NASA's Langley Research Center. The 3000 ton (6 million pound), 36' x 21'x 19.5' assembly of forged steel serves as the heart of the 600 million electron volt, high energy proton accelerator.

  4. Core Directions in HRD.

    ERIC Educational Resources Information Center

    1996

    This document consists of four papers presented at a symposium on core directions in human resource development (HRD) moderated by Verna Willis at the 1996 conference of the Academy of Human Resource Development. "Reengineering the Organizational HRD Function: Two Case Studies" (Neal Chalofsky) reports an action research study in which the…

  5. Core Noise Reduction

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduce-Perceived-Noise Technical Challenge; and the current research activities in the core noise area. Recent work1 on the turbine-transmission loss of combustor noise is briefly described, two2,3 new NRA efforts in the core-noise area are outlined, and an effort to develop CMC-based acoustic liners for broadband noise reduction suitable for turbofan-core application is delineated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. The Subsonic Fixed Wing Project's Reduce-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries.

  6. Fissioning Plasma Core Reactor

    NASA Technical Reports Server (NTRS)

    Albright, Dennis; Butler, Carey; West, Nicole; Cole, John W. (Technical Monitor)

    2002-01-01

    Institute for Scientific Research, Inc. (ISR) research program consist of: 1.Study core physics by adapting existing codes: MCNP4C - Monte Carlo code; COMBINE/VENTURE - diffusion theory; SCALE4 - Monte Carlo, with many utility codes. 2. Determine feasibility and study major design parameters: fuel selection, temperature and reflector sizing. 3. Study reactor kinetics: develop QCALC1 to model point kinetics; study dynamic behavior of the power release.

  7. The Southern Annular Mode change for the Last Glacial Maximum derived from PMIP2 simulations

    NASA Astrophysics Data System (ADS)

    Kim, Seong-Joong; Lu, Junmei; Kim, Baek-Min

    2016-04-01

    The increasing trend of the Southern Annular Mode (SAM) in recent decades has influenced the climate change in the southern hemisphere. How will the SAM respond to the increase of greenhouse gases in the future still remains uncertain. Understanding the variability of the SAM in the past under colder climate such as the Last Glacial Maximum (LGM) helps understand the response of the SAM for the future warm climate. We analyzed the changes in the SAM for the LGM in comparison to the pre-industrial (PI) simulations using 5 coupled ocean-atmosphere models (i.e. NCAR Community Climate System Model version 3 (CCSM), LASG/IAP Flexible Global Ocean-Atmosphere-Land System Model (FGOALS), L'Institut Pierre-Simon Laplace-CM4 (IPSL), Model for Interdisciplinary Research on Climate version 3.2 (MIROC), and third climate configuration of the Met Office Unified Model with Met Office Surface Exchanges Scheme version 2 (HadCM)) from the second phase of Paleoclimate Modelling Intercomparison Project (PMIP2). In CCSM, MIROC, IPSL, and FGOALS, the variability of the simulated SAM appears to be reduced in the LGM than the PI with a decrease in the standard deviation of the SAM index. Overall, four out of five models suggest the weaker variability of the SAM in the LGM, in consistent with the weaker southern hemisphere polar vortex and westerly winds at the surface found in some proxy records and model analyses. The weakening of the SAM in the LGM is associated with the increase in the vertical propagation of Rossby waves in southern high latitudes.

  8. Fundamental mode evolution in long, large-core (>100 μm) adiabatic tapers

    NASA Astrophysics Data System (ADS)

    Kerttula, Juho; Filippov, Valery; Chamorovskii, Yuri; Ustimchik, Vasily; Okhotnikov, Oleg G.

    2013-03-01

    We have experimentally investigated fundamental mode propagation in few-meter-long adiabatic step-index tapers with high numerical aperture, core diameter up to 117μm (V=38), and tapering ratio up to 18. We confirmed single fundamental mode guiding in tapers with uniform core index profile by several experiments. We observed an annular near field distribution and degraded beam quality for large output core diameters, found to occur due to intrinsic mechanical stress in the fibers. We expect that eliminating the stress would prevent the mode deformation and allow constructing single-mode, diffraction-limited tapered large-mode-area amplifiers with a good beam shape.

  9. Design of the Annular Suspension and Pointing System (ASPS) (including design addendum)

    NASA Technical Reports Server (NTRS)

    Cunningham, D.; Gismondi, T.; Hamilton, B.; Kendig, J.; Kiedrowski, J.; Vroman, A.; Wilson, G.

    1980-01-01

    The Annular Suspension and Pointing System is an experiment pointing mount designed for extremely precise 3 axis orientation of shuttle experiments. It utilizes actively controlled magnetic bearing to provide noncontacting vernier pointing and translational isolation of the experiment. The design of the system is presented and analyzed.

  10. Coaxial passive undulator for the rotational-velocity pumping of annular relativistic electron beams

    NASA Astrophysics Data System (ADS)

    Aleksandrov, A. F.; Vesnin, V. L.; Kubarev, V. A.

    1991-08-01

    It is proposed that a passive magnetic undulator of coaxial design be used for the transverse-velocity pumping of annular relativistic electron beams. This undulator leads to a substantial reduction in the nonuniformity of the undulator field on the beam thickness. An analytical-numerical methodology is developed which enables a detailed investigation and optimization of the nonstationary field structure.

  11. Annular Pancreas: A Cause of Gastric Outlet Obstruction in a 20-Year-Old Patient

    PubMed Central

    Alahmadi, Raha; Almuhammadi, Saud

    2014-01-01

    Patient: Female, 20 Final Diagnosis: Annular pancreas Symptoms: Food intolerance • vomiting Medication:— Clinical Procedure: — Specialty: Gastroenterology and Hepatology Objective: Congenital defects/diseases Background: Annular pancreas is a congenital anomaly that consists of a ring of pancreatic tissue partially or completely encircling the descending portion of the duodenum. It is formed due to the failure of the ventral bud to rotate, thus it elongates and encircles the upper part of the duodenum. It can present in a wide range of clinical severities, and can affect neonates to the elderly, making it difficult to diagnosis. Although diagnosis of annular pancreas can be made pre-operatively by upper GI series, upper GI endoscopy, or CT scan, 40% of diagnoses require surgery for confirmation. Case Report: We report the case of a 20-year-old woman presenting with history of vomiting and weight loss since childhood. We present the clinical characteristics, surgical management in the form of bypass procedure done through a duodenojujenostomy, and follow-up of the patient. Conclusions: Annular pancreas occasionally presents in adults. Variable presentations have been described in the literature, including pancreatic neoplasm, pancreatitis, obstructive jaundice, duodenal obstruction, and peptic ulcer diseases. Most studies of these lesions are single case reports or small series, which do not allow a surgeon to accumulate extensive experience; therefore, reliance on the combined experience of others in recognition and appropriate management has been the norm. PMID:25300027

  12. Colonic atresia associated with annular pancreas: An extremely rare and previously unreported association

    PubMed Central

    Halder, Pankaj; Kumar, Rajarshi; Mukhopadhyay, Madhumita; Mandal, Kartik Chandra; Mukhopadhyay, Biswanath

    2015-01-01

    Colonic atresia is the rarest entity among the all intestinal atresias and may be associated with anterior abdominal wall defect, small intestinal atresia, Hirschsprung's disease, and other anomalies. Here, we are reporting a case of colonic atresia associated with annular pancreas, which has not been reported previously to the best of our knowledge. PMID:26166992

  13. Experimental critical parameters of enriched uranium solution in annular tank geometries

    SciTech Connect

    Rothe, R.E.

    1996-04-01

    A total of 61 critical configurations are reported for experiments involving various combinations of annular tanks into which enriched uranium solution was pumped. These experiments were performed at two widely separated times in the 1980s under two programs at the Rocky Flats Plant`s Critical Mass Laboratory. The uranyl nitrate solution contained about 370 g of uranium per liter, but this concentration varied a little over the duration of the studies. The uranium was enriched to about 93% [sup 235]U. All tanks were typical of sizes commonly found in nuclear production plants. They were about 2 m tall and ranged in diameter from 0.6 m to 1.5 m. Annular thicknesses and conditions of neutron reflection, moderation, and absorption were such that criticality would be achieved with these dimensions. Only 13 of the entire set of 74 experiments proved to be subcritical when tanks were completely filled with solution. Single tanks of several radial thicknesses were studied as well as small line arrays (1 x 2 and 1 x 3) of annular tanks. Many systems were reflected on four sides and the bottom by concrete, but none were reflected from above. Many experiments also contained materials within and outside the annular regions that contained strong neutron absorbers. One program had such a thick external moderator/absorber combination that no reflector was used at all.

  14. Performance of a cascade in an annular vortex-generating tunnel over range of Reynolds numbers

    NASA Technical Reports Server (NTRS)

    Thurston, Sidney; Brunk, Ralph E

    1951-01-01

    Total-pressure deficiency for an annular cascade of 65-(12)10 blades was measured at three radial stations over a range of Reynolds numbers from 50,000 to 250,000 and at angles of attack of 15 degrees and 25 degrees. The variation of turning angle and shape of static pressure distribution at these stations is also shown.

  15. Velocity gradient method for calulating velocities in an axisymmetric annular duct

    NASA Technical Reports Server (NTRS)

    Katsanis, T.

    1982-01-01

    The velocity distribution along an arbitrary line between the inner and outer walls of an annular duct with axisymmetric swirling flow is calculated. The velocity gradient equation is used with an assumed variation of meridional streamline curvature. Upstream flow conditions can vary between the inner and outer walls, and an assumed total pressure distribution can be specified.

  16. Treatment with Doxycycline of Generalized Annular Elastolytic Giant Cell Granuloma Associated with Borrelia burgdorferi Infection

    PubMed Central

    Tas, B; Caglar, A; Ozdemir, B

    2015-01-01

    ABSTRACT This is a case of generalized annular elastolytic giant cell granuloma (AEGCG) associated with borrelia infection and genes of p-30, p-31, p-39. A possible cross-mediated reaction from the T-cell type which might have induced the AEGCG is discussed from the concept of “heat-shock proteins (HSPs) and molecular mimicry”. PMID:26624605

  17. Coupled vibration analysis of liquid-filled rigid cylindrical storage tank with an annular plate cover

    NASA Astrophysics Data System (ADS)

    Kim, Young-Wann; Lee, Young-Shin

    2005-01-01

    An analytical approach is developed to investigate the vibration characteristics of the sloshing and bulging modes for a liquid-filled rigid circular cylindrical storage tank with an elastic annular plate in contact with sloshing surface of liquid. The cylindrical tank is filled with a non-viscous and incompressible liquid having a free surface. The free surface of liquid is partially covered by an annular plate with outer clamped edge and inner free edge. The liquid domain is limited by a rigid cylindrical wall and a rigid flat bottom. As the effect of free surface waves is taken into account in the analysis, the bulging and sloshing modes are studied. The solution for the velocity potential of liquid movement is assumed as a suitable harmonic function that satisfies the Laplace equation and the relevant boundary conditions. The Rayleigh-Ritz method is used to derive the frequency equation of the liquid-filled rigid cylindrical tank with an annular plate on the sloshing surface. The effects of inner-to-outer radius ratio, thickness of annular plate and liquid volume on vibration characteristics of the storage tank are studied. To demonstrate the validity of the present analytical approach, the published results are compared for the rigid cylindrical tank without a plate and the finite element analysis is performed for the tank with a plate.

  18. Acute Renal Infarction Secondary to Calcific Embolus from Mitral Annular Calcification

    SciTech Connect

    Bande, Dinesh; Abbara, Suhny; Kalva, Sanjeeva P.

    2011-06-15

    We report a case of a 62-year-old man who presented with right groin pain who subsequently was found to have a renal infarct secondary to calcific embolus from mitral annular calcification on CT and angiography. We briefly review the literature and discuss the importance of this entity in clinical practice.

  19. Development of Parallel Image Detection System Using Annular Pupils for Scanning Transmission Electron Microscope

    SciTech Connect

    Matsutani, Takaomi; Taya, Masaki; Ikuta, Takashi; Tanaka, Takeo; Kimura, Yoshihide; Takai, Yoshizo; Kawasaki, Tadahiro; Ichihashi, Mikio

    2010-10-13

    A parallel image detection system using an annular pupil for electron optics were developed to realize an increase in the depth of focus, aberration-free imaging and separation of amplitude and phase images under scanning transmission electron microscopy (STEM). Apertures for annular pupils able to suppress high-energy electron scattering were developed using a focused ion beam (FIB) technique. The annular apertures were designed with outer diameter of oe 40 {mu}m and inner diameter of oe32 {mu}m. A taper angle varying from 20 deg. to 1 deg. was applied to the slits of the annular apertures to suppress the influence of high-energy electron scattering. Each azimuth angle image on scintillator was detected by a multi-anode photomultiplier tube assembly through 40 optical fibers bundled in a ring shape. To focus the image appearing on the scintillator on optical fibers, an optical lens relay system attached with CCD camera was developed. The system enables the taking of 40 images simultaneously from different scattered directions.

  20. Quantifying barotropic and baroclinic eddy feedbacks in the persistence of the Annular Modes

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Nie, Y.; Chen, G.; Yang, X. Q.; Burrows, D. A.

    2015-12-01

    Understanding the persistence of the Annular Modes is important for the extratropical intraseasonal and decadal predictability. This study introduces a new method to quantify the relative roles of the barotropic and baroclinic eddy feedbacks
contributing to the Annular Modes persistence. Through a hybrid Eulerian-Lagrangian Finite Amplitude Wave Activity diagnostic using the ERA-40 and ERA-Interim reanalysis data, it is found that for the Southern Annular Mode (SAM): (i) transient wave activity is important in driving the SAM but provides a negative feedback
to the SAM persistence. (ii) Irreversible PV mixing, through barotropic processes in the upper troposphere, plays an important role in driving and sustaining the SAM variability. Particularly, following the poleward shift in the eddy-driven jet, the reduction/enhancement in effective diffusivity on the jet's poleward/equatorward flank can be understood by a stronger/weaker zonal
jet acting as a robust/leaky mixing barrier. (iii) Baroclinic eddy generation and vertical wave propagation mainly act to sustain the anomalous zonal wind in SAM. The diagnostics are also applied to assess the Annular Mode simulations in simplified and comprehensive CMIP5 models to understand the bias of the SAM simulations in numerical models.

  1. Acute renal infarction secondary to calcific embolus from mitral annular calcification.

    PubMed

    Bande, Dinesh; Abbara, Suhny; Kalva, Sanjeeva P

    2011-06-01

    We report a case of a 62-year-old man who presented with right groin pain who subsequently was found to have a renal infarct secondary to calcific embolus from mitral annular calcification on CT and angiography. We briefly review the literature and discuss the importance of this entity in clinical practice.

  2. Testing the kibble-zurek scenario with annular josephson tunnel junctions

    PubMed

    Kavoussanaki; Monaco; Rivers

    2000-10-16

    In parallel with Kibble's description of the onset of phase transitions in the early Universe, Zurek has provided a simple picture for the onset of phase transitions in condensed matter systems, supported by agreement with experiments in 3He and superconductors. We show how experiments with annular Josephson tunnel junctions can, and do, provide further support for this scenario.

  3. Core Noise - Increasing Importance

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduced-Perceived-Noise Technical Challenge; and the current research activities in the core-noise area, with additional details given about the development of a high-fidelity combustor-noise prediction capability as well as activities supporting the development of improved reduced-order, physics-based models for combustor-noise prediction. The need for benchmark data for validation of high-fidelity and modeling work and the value of a potential future diagnostic facility for testing of core-noise-reduction concepts are indicated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor

  4. Core-Noise

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2010-01-01

    This presentation is a technical progress report and near-term outlook for NASA-internal and NASA-sponsored external work on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system level noise metrics for the 2015, 2020, and 2025 timeframes; the emerging importance of core noise and its relevance to the SFW Reduced-Noise-Aircraft Technical Challenge; the current research activities in the core-noise area, with some additional details given about the development of a high-fidelity combustion-noise prediction capability; the need for a core-noise diagnostic capability to generate benchmark data for validation of both high-fidelity work and improved models, as well as testing of future noise-reduction technologies; relevant existing core-noise tests using real engines and auxiliary power units; and examples of possible scenarios for a future diagnostic facility. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Noise-Aircraft Technical Challenge aims to enable concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical for enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor designs could increase

  5. The clinical application of “jetting suture” technique in annular repair under microendoscopic discectomy

    PubMed Central

    Qi, Lei; Li, Mu; Si, Haipeng; Wang, Liang; Jiang, Yunpeng; Zhang, Shuai; Li, Le

    2016-01-01

    Abstract To introduce a new designed suture technique in annular repair under the microendoscopic discectomy (MED) surgery and to evaluate the clinical application of the technique in annular repair under MED with at least 2-year follow-up period. A new method of annular repair was designed and named “jetting suture” technique. Thirty consecutive patients with lumbar disc herniation were enrolled in the prospective single-cohort observational study. Patients were followed up at intervals of preoperative, postoperative 1 week, 3 months, 6 months, 1 year, and last follow-up. The clinical outcomes were evaluated by using Japanese Orthopaedic Association (JOA) score, Oswestry Disability Index, and modified Mcnab criteria. The procedure was successfully performed in all cases. No case required conversion to an open procedure. The mean age of patients was 36.6 years. Average blood loss was 45.8 ± 10.2 mL. The preoperative symptoms were alleviated significantly after surgery. All the standardized measures improved significantly at the last follow-up, including JOA score (10.1 to 26.6; P < 0.05) and Oswestry Disability Index (75.3 to 9.6; P < 0.05). Improvement rate of JOA score was 86.4%. Approximately 83.4% of patients reported good or excellent outcomes based on modified Mcnab criteria. No postoperative complication and recurrence of disc herniation was reported. The designed “jetting suture” technique in annular repair under MED can be performed safely and effectively. It could be a viable alternative to annular repair under lumbar discectomy. PMID:27495101

  6. Uncertainty methodology for the strongly coupled physical phenomena associated with annular flow

    SciTech Connect

    Lane, J. W.; Aumiller Jr, D. L.

    2012-07-01

    Best-Estimate plus Uncertainty (BEPU) methods are slowly supplanting the use of deterministic analysis methods for thermal-hydraulic analyses. As the uncertainty methodologies evolve it is expected that, where both experimental techniques allow and data are available, there will be a shift to quantifying the uncertainty in increasingly more fundamental parameters. For example, for annular flow in a three-field analysis environment (vapor, liquid film, droplet), the driving parameters would be: a) film interfacial shear stress, b) droplet drag, c) droplet entrainment rate and d) droplet deposition rate. An improved annular flow modeling package was recently developed and implemented in an in-house version of the COBRA-TF best-estimate subchannel analysis tool (Lane, 2009). Significant improvement was observed in the code-to-data predictions of several steam-water annular flow tests following the implementation of this modeling package; however, to apply this model set in formal BEPU analysis requires uncertainty distributions to be determined. The unique aspect of annular flow, and the topic of the present work, is the strong coupling between the interfacial drag, entrainment and deposition phenomena. Ideally the uncertainty in each phenomenon would be isolated; however, the situation is further complicated by an inability to experimentally isolate and measure the individual rate processes (particularly entrainment rate), which results in available experimental data that are inherently integral in nature. This paper presents a methodology for isolating the individual physical phenomena of interest, to the extent that the currently available experimental data allow, and developing the corresponding uncertainty distributions for annular flow. (authors)

  7. Core facilities: maximizing the return on investment.

    PubMed

    Farber, Gregory K; Weiss, Linda

    2011-08-10

    To conduct high-quality state-of-the-art research, clinical and translational scientists need access to specialized core facilities and appropriately trained staff. In this time of economic constraints and increasing research costs, organized and efficient core facilities are essential for researchers who seek to investigate complex translational research questions. Here, we describe efforts at the U.S. National Institutes of Health and academic medical centers to enhance the utility of cores.

  8. Core Facilities: Maximizing the Return on Investment

    PubMed Central

    Farber, Gregory K.; Weiss, Linda

    2011-01-01

    To conduct high-quality state-of-the-art research, clinical and translational scientists need access to specialized core facilities and appropriately trained staff. In this time of economic constraints and increasing research costs, organized and efficient core facilities are essential for researchers who seek to investigate complex translational research questions. Here, we describe efforts at the U.S . National Institutes of Health and academic medical centers to enhance the utility of cores. PMID:21832235

  9. Advances in core drilling technology

    NASA Astrophysics Data System (ADS)

    Holdsworth, G.

    Some notable technical advances in drill design were reported at the meeting, held in Canada August 30-September 1, 1982, at the University of Calgary. Chief amongst these was a battery powered, computer assisted electromechanical core drill which has recently been used by the Danes in Greenland to continuously core to the base of the ice sheet at 2038 m. This is the deepest coring operation so far on the Greenland ice sheet. (The record for deep glacier drilling is held by the U.S. Army Cold Regions Research and Engineering Laboratory for the continuous coring through 2164 m of ice to bedrock at Byrd Station, Antarctica, in 1968). In early 1982, a current Soviet core drilling operation was reported to be at a depth of 2000 m at Vostok station, Antarctica, where the total ice thickness is about 4000 m; the goal of core drilling the entire ice thickness there could be achieved before the end of 1983.

  10. Method for Tracking Core-Contributed Publications

    PubMed Central

    Loomis, Cynthia A.; Curchoe, Carol Lynn

    2012-01-01

    Accurately tracking core-contributed publications is an important and often difficult task. Many core laboratories are supported by programmatic grants (such as Cancer Center Support Grant and Clinical Translational Science Awards) or generate data with instruments funded through S10, Major Research Instrumentation, or other granting mechanisms. Core laboratories provide their research communities with state-of-the-art instrumentation and expertise, elevating research. It is crucial to demonstrate the specific projects that have benefited from core services and expertise. We discuss here the method we developed for tracking core contributed publications. PMID:23204927

  11. Mercury's Core

    NASA Astrophysics Data System (ADS)

    Peale, S. J.

    2005-05-01

    In determining Mercury's core structure from its rotational properties, the location of Cassini state 1 is crucial. Convincing radar evidence indicates that the mantle rests on a liquid layer (Margot et al. 2005), but there are no empirical constraints on the moment of inertia C/MR2, which constraints must wait for the determination of the gravitational coefficients J2 and C22 from the MESSENGER orbiting spacecraft, and an accurate determination of the obliquity of the Cassini state. Tidal and core-mantle dissipation drive the spin to the Cassini state with a time scale O(105) years, so the spin should occupy the Cassini state and thereby define its obliquity---unless there has been a recent excitation of a free precession of the spin. Another way the spin might be displaced from the Cassini state is if the variations in the orbital elements, which change the position of the Cassini state, cause the spin axis to lag behind as it attempts to follow the state. Fortunately, the solid angle the spin axis encloses as it precesses around the Cassini state is an adiabatic invariant, and it is conserved if the orbital element variations are slow compared to the precession rate. As the precession period is O(1000) years, and the time scales of orbital parameter variations are O(105) years, the spin axis should remain very close to the Cassini state if it were ever close. But how close is close? The increasing precision of the radar and eventual spacecraft measurements warrants a check on the likely proximity of the spin axis to the Cassini state. By numerically following the positions of the spin axis and Cassini state with orbital parameters varying with time scales and amplitudes comparable to the real variations, we show that the spin should remain within 1″ of the Cassini state once dissipative torques bring it there. The current spin axis position should thus define the Cassini state sufficiently to put reasonably tight constraints on the core structure

  12. Core descriptions, core photographs, physical property logs and surface textural data of sediment cores recovered from the continental shelf of the Monterey Bay National Marine Sanctuary during the research cruises M-1-95-MB, P-2-95-MB, and P-1-97-MB

    USGS Publications Warehouse

    Orzech, Kevin M.; Dahl, Wendy E.; Edwards, Brian D.

    2001-01-01

    In response to the 1992 creation of the Monterey Bay National Marine Sanctuary (MBNMS), the United States Geological Survey (USGS) initiated a multiyear investigation of the Sanctuary continental margin. As part of the investigative effort, this report summarizes the shipboard procedures, subsequent laboratory analyses, and data results from three seafloor sampling cruises conducted on the continental shelf between Monterey peninsula, CA and San Francisco, CA. The cruises were conducted in 1995 aboard the NOAA Ship McArthur (M-1-95-MB) and in 1995 and 1997 aboard the R/V Point Sur (P-2-95-MB and P-1-97-MB). Scientists and representatives from the Environmental Protection Agency (EPA), the National Oceanic and Atmospheric Administration (NOAA), the California Department of Fish and Game (CDFG), the University of California Santa Cruz (UCSC), and the San Jose State University Moss Landing Marine Laboratory (SJSU-MLML) supported the research effort. In this report we present sediment descriptions, sediment textural data, physical property logs, station metadata, and photographs of subcores from a total of three hundred and eighty four sample stations. At these sites either a box corer, MultiCore™r, grab sampler or a combination of these sampling devices were used to collect the sea floor sediments. The report is presented in an interactive web-based format with each mapped core station linked to the corresponding description and photo, and to a spreadsheet of surface texture and other sampling data.

  13. Precipitation and synoptic regime in two extreme years 2009 and 2010 at Dome C, Antarctica - implications for ice core interpretation

    NASA Astrophysics Data System (ADS)

    Schlosser, Elisabeth; Stenni, Barbara; Valt, Mauro; Cagnati, Anselmo; Powers, Jordan G.; Manning, Kevin W.; Raphael, Marilyn; Duda, Michael G.

    2016-04-01

    At the East Antarctic deep ice core drilling site Dome C, daily precipitation measurements were initiated in 2006 and are being continued until today. The amounts and stable isotope ratios of the precipitation samples as well as crystal types are determined. Within the measuring period, the two years 2009 and 2010 showed striking contrasting temperature and precipitation anomalies, particularly in the winter seasons. The reasons for these anomalies are analysed using data from the mesoscale atmospheric model WRF (Weather Research and Forecasting Model) run under the Antarctic Mesoscale Prediction System (AMPS). 2009 was relatively warm and moist due to frequent warm air intrusions connected to amplification of Rossby waves in the circumpolar westerlies, whereas the winter of 2010 was extremely dry and cold. It is shown that while in 2010 a strong zonal atmospheric flow was dominant, in 2009 an enhanced meridional flow prevailed, which increased the meridional transport of heat and moisture onto the East Antarctic plateau and led to a number of high-precipitation/warming events at Dome C. This was also evident in a positive (negative) SAM (Southern Annular Mode) index and a negative (positive) ZW3 (zonal wave number three) index during the winter months of 2010 (2009). Changes in the frequency or seasonality of such event-type precipitation can lead to a strong bias in the air temperature derived from stable water isotopes in ice cores.

  14. Initial verification and validation of RAZORBACK - A research reactor transient analysis code

    SciTech Connect

    Talley, Darren G.

    2015-09-01

    This report describes the work and results of the initial verification and validation (V&V) of the beta release of the Razorback code. Razorback is a computer code designed to simulate the operation of a research reactor (such as the Annular Core Research Reactor (ACRR)) by a coupled numerical solution of the point reactor kinetics equations, the energy conservation equation for fuel element heat transfer, and the mass, momentum, and energy conservation equations for the water cooling of the fuel elements. This initial V&V effort was intended to confirm that the code work to-date shows good agreement between simulation and actual ACRR operations, indicating that the subsequent V&V effort for the official release of the code will be successful.

  15. Assessment of the Preservation of Impact Residues in Stardust Analogue Craters Using Advanced EDX Imagery with an Annular SDD

    NASA Astrophysics Data System (ADS)

    Salge, T.; Kearsley, A. T.; Price, M. C.; Burchell, M. J.; Cole, M. J.

    2016-08-01

    Low voltage SEM/EDX analysis with an annular SDD can show relationships between even tiny impact residues throughout complex crater shapes. The technique should be used as a preliminary reconnaissance method on all Stardust cometary dust craters.

  16. High-Flux Femtosecond X-Ray Emission from Controlled Generation of Annular Electron Beams in a Laser Wakefield Accelerator

    NASA Astrophysics Data System (ADS)

    Zhao, T. Z.; Behm, K.; Dong, C. F.; Davoine, X.; Kalmykov, S. Y.; Petrov, V.; Chvykov, V.; Cummings, P.; Hou, B.; Maksimchuk, A.; Nees, J. A.; Yanovsky, V.; Thomas, A. G. R.; Krushelnick, K.

    2016-08-01

    Annular quasimonoenergetic electron beams with a mean energy in the range 200-400 MeV and charge on the order of several picocoulombs were generated in a laser wakefield accelerator and subsequently accelerated using a plasma afterburner in a two-stage gas cell. Generation of these beams is associated with injection occurring on the density down ramp between the stages. This well-localized injection produces a bunch of electrons performing coherent betatron oscillations in the wakefield, resulting in a significant increase in the x-ray yield. Annular electron distributions are detected in 40% of shots under optimal conditions. Simultaneous control of the pulse duration and frequency chirp enables optimization of both the energy and the energy spread of the annular beam and boosts the radiant energy per unit charge by almost an order of magnitude. These well-defined annular distributions of electrons are a promising source of high-brightness laser plasma-based x rays.

  17. Examining the Relationship of QualityCore[R] Implementation and Student Achievement in Algebra I. ACT Research Report Series, 2012 (4)

    ERIC Educational Resources Information Center

    Ndum, Edwin; Allen, Jeff; Fisher, Teri

    2012-01-01

    We assessed the relationship of level of QualityCore[R] implementation and student achievement in Algebra I. The study is based on 1,291 9th grade students in three large metropolitan school districts who took EXPLORE in the fall and the QualityCore Algebra I end-of-course assessment (EOC) in the spring. During the same period, the students' 41…

  18. Annular shape silver lined proportional counter for on-line pulsed neutron yield measurement

    NASA Astrophysics Data System (ADS)

    Dighe, P. M.; Das, D.

    2015-04-01

    An annular shape silver lined proportional counter is developed to measure pulsed neutron radiation. The detector has 314 mm overall length and 235 mm overall diameter. The central cavity of 150 mm diameter and 200 mm length is used for placing the neutron source. Because of annular shape the detector covers >3π solid angle of the source. The detector has all welded construction. The detector is developed in two halves for easy mounting and demounting. Each half is an independent detector. Both the halves together give single neutron pulse calibration constant of 4.5×104 neutrons/shot count. The detector operates in proportional mode which gives enhanced working conditions in terms of dead time and operating range compared to Geiger Muller based neutron detectors.

  19. Entrainment rate of droplets in the ripple-annular regime for small vertical tubes

    SciTech Connect

    Lopez de Bertodano, M.A.; Assad, A.; Beus, S.G.

    1998-06-01

    Two-fluid model predictions of film dryout in annular flow are limited by the uncertainties in the constitutive relations for the entrainment rate of droplets from the liquid film. The main cause of these uncertainties is the lack of separate effects experimental data in the range of the operating conditions in nuclear power reactors. Air/water and Freon-113 entrainment rate data have been obtained in 10 mm tubes using the film extraction technique. These experiments have been scaled to approach high pressure steam-water flow conditions. The effects of surface tension and density ratio, missing from most previous data sets, have been systematically tested. The entrainment rate mechanism is assumed to be a Kelvin-Helmholtz instability. Based on this analysis and two previous correlations, a new correlation is proposed that is valid for low viscosity fluids in small ducts in the ripple annular regime.

  20. Collective motion of symmetric camphor papers in an annular water channel

    NASA Astrophysics Data System (ADS)

    Ikura, Yumihiko S.; Heisler, Eric; Awazu, Akinori; Nishimori, Hiraku; Nakata, Satoshi

    2013-07-01

    We investigate the collective motion of symmetric self-propelled objects that are driven by a difference in the surface tension. The objects move around an annular water channel spontaneously and interact through the camphor layer that develops on the water surface. We found that two collective motion modes, discrete and continuous density waves, are generated depending on the number of self-propelled objects. The two modes are characterized by examining the local and global dynamics, and the collective motion mechanism is discussed in relation to the distribution of camphor concentration in the annular water channel. We conclude that the difference between these two modes originates from that of the driving mechanism that pushes a camphor paper away from a cluster, through which mechanism density waves are generated and maintained.