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  1. Multifilter Rotating Shadowband Radiometer (MFRSR) Handbook

    SciTech Connect (OSTI)

    Hodges, GB; Michalsky, JJ

    2011-02-07

    The visible Multifilter Rotating Shadowband Radiometer (MFRSR) is a passive instrument that measures global and diffuse components of solar irradiance at six narrowband channels and one open, or broadband, channel (Harrison et al. 1994). Direct irradiance is not a primary measurement, but is calculated using the diffuse and global measurements. To collect one data record, the MFRSR takes measurements at four different shadowband positions. The first measurement is taken with the shadowband in the nadir (home) position. The next three measurements are, in order, the first side-band, sun-blocked, and second side-band. The side-band measurements are used to correct for the portion of the sky obscured by the shadowband. The nominal wavelengths of the narrowband channels are 415, 500, 615, 673, 870, and 940 nm. From such measurements, one may infer the atmosphere's aerosol optical depth at each wavelength. In turn, these optical depths may be used to derive information about the column abundances of ozone and water vapor (Michalsky et al. 1995), as well as aerosol (Harrison and Michalsky 1994) and other atmospheric constituents.

  2. ARM Multi-Filter Rotating Shadowband Radiometer (MFRSR): irradiances

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Hodges, Gary

    1993-07-04

    The multifilter rotating shadowband radiometer (MFRSR) takes spectral measurements of direct normal, diffuse horizontal and total horizontal solar irradiances. These measurements are at nominal wavelengths of 415, 500, 615, 673, 870, and 940 nm. The measurements are made at a user-specified time interval, usually about one minute or less. The sampling rate for the Atmospheric Radiation Measurement (ARM) Climate Research Facility MFRSRs is 20 seconds. From such measurements, one may infer the atmosphere's optical depth at the wavelengths mentioned above. In turn, these optical depths may be used to derive information about the column abundances of ozone and water vapor (Michalsky et al. 1995), as well as aerosol (Michalsky et al. 1994) and other atmospheric constituents. A silicon detector is also part of the MFRSR. This detector provides a measure of the broadband direct normal, diffuse horizontal and total horizontal solar irradiances. A MFRSR head that is mounted to look vertically downward can measure upwelling spectral irradiances. In the ARM system, this instrument is called a multifilter radiometer (MFR). At the Southern Great Plains (SGP) there are two MFRs; one mounted at the 10-m height and the other at 25 m. At the North Slope of Alaska (NSA) sites, the MFRs are mounted at 10 m. MFRSR heads are also used to measure normal incidence radiation by mounting on a solar tracking device. These are referred to as normal incidence multi-filter radiometers (NIMFRs) and are located at the SGP and NSA sites. Another specialized use for the MFRSR is the narrow field of view (NFOV) instrument located at SGP. The NFOV is a ground-based radiometer (MFRSR head) that looks straight up.

  3. ARM Multi-Filter Rotating Shadowband Radiometer (MFRSR): irradiances

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Hodges, Gary

    The multifilter rotating shadowband radiometer (MFRSR) takes spectral measurements of direct normal, diffuse horizontal and total horizontal solar irradiances. These measurements are at nominal wavelengths of 415, 500, 615, 673, 870, and 940 nm. The measurements are made at a user-specified time interval, usually about one minute or less. The sampling rate for the Atmospheric Radiation Measurement (ARM) Climate Research Facility MFRSRs is 20 seconds. From such measurements, one may infer the atmosphere's optical depth at the wavelengths mentioned above. In turn, these optical depths may be used to derive information about the column abundances of ozone and water vapor (Michalsky et al. 1995), as well as aerosol (Michalsky et al. 1994) and other atmospheric constituents. A silicon detector is also part of the MFRSR. This detector provides a measure of the broadband direct normal, diffuse horizontal and total horizontal solar irradiances. A MFRSR head that is mounted to look vertically downward can measure upwelling spectral irradiances. In the ARM system, this instrument is called a multifilter radiometer (MFR). At the Southern Great Plains (SGP) there are two MFRs; one mounted at the 10-m height and the other at 25 m. At the North Slope of Alaska (NSA) sites, the MFRs are mounted at 10 m. MFRSR heads are also used to measure normal incidence radiation by mounting on a solar tracking device. These are referred to as normal incidence multi-filter radiometers (NIMFRs) and are located at the SGP and NSA sites. Another specialized use for the MFRSR is the narrow field of view (NFOV) instrument located at SGP. The NFOV is a ground-based radiometer (MFRSR head) that looks straight up.

  4. The multi-filter rotating shadowband radiometer (MFRSR) - precision infrared radiometer (PIR) platform in Fairbanks: Scientific objectives

    SciTech Connect (OSTI)

    Stamnes, K.; Leontieva, E.

    1996-04-01

    The multi-filter rotating shadowband radiometer (MFRSR) and precision infrared radiometer (PIR) have been employed at the Geophysical Institute in Fairbanks to check their performance under arctic conditions. Drawing on the experience of the previous measurements in the Arctic, the PIR was equipped with a ventilator to prevent frost and moisture build-up. We adopted the Solar Infrared Observing Sytem (SIROS) concept from the Southern Great Plains Cloud and Radiation Testbed (CART) to allow implementation of the same data processing software for a set of radiation and meteorological instruments. To validate the level of performance of the whole SIROS prior to its incorporation into the North Slope of Alaska (NSA) Cloud and Radiation Testbed Site instrumental suite for flux radiatin measurements, the comparison between measurements and model predictions will be undertaken to assess the MFRSR-PIR Arctic data quality.

  5. Failure and Redemption of Multifilter Rotating Shadowband Radiometer

    Office of Scientific and Technical Information (OSTI)

    (MFRSR)/Normal Incidence Multifilter Radiometer (NIMFR) Cloud Screening: Contrasting Algorithm Performance at Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) and Southern Great Plains (SGP) Sites (Journal Article) | SciTech Connect Journal Article: Failure and Redemption of Multifilter Rotating Shadowband Radiometer (MFRSR)/Normal Incidence Multifilter Radiometer (NIMFR) Cloud Screening: Contrasting Algorithm Performance at Atmospheric Radiation Measurement (ARM) North

  6. Failure and Redemption of Multifilter Rotating Shadowband Radiometer (MFRSR)/Normal Incidence Multifilter Radiometer (NIMFR) Cloud Screening: Contrasting Algorithm Performance at Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) and Southern Great Plains (SGP) Sites

    SciTech Connect (OSTI)

    Kassianov, Evgueni I.; Flynn, Connor J.; Koontz, Annette S.; Sivaraman, Chitra; Barnard, James C.

    2013-09-11

    Well-known cloud-screening algorithms, which are designed to remove cloud-contaminated aerosol optical depths (AOD) from AOD measurements, have shown great performance at many middle-to-low latitude sites around the world. However, they may occasionally fail under challenging observational conditions, such as when the sun is low (near the horizon) or when optically thin clouds with small spatial inhomogeneity occur. Such conditions have been observed quite frequently at the high-latitude Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) sites. A slightly modified cloud-screening version of the standard algorithm is proposed here with a focus on the ARM-supported Multifilter Rotating Shadowband Radiometer (MFRSR) and Normal Incidence Multifilter Radiometer (NIMFR) data. The modified version uses approximately the same techniques as the standard algorithm, but it additionally examines the magnitude of the slant-path line of sight transmittance and eliminates points when the observed magnitude is below a specified threshold. Substantial improvement of the multi-year (1999-2012) aerosol product (AOD and its Angstrom exponent) is shown for the NSA sites when the modified version is applied. Moreover, this version reproduces the AOD product at the ARM Southern Great Plains (SGP) site, which was originally generated by the standard cloud-screening algorithms. The proposed minor modification is easy to implement and its application to existing and future cloud-screening algorithms can be particularly beneficial for challenging observational conditions.

  7. Aerosol Retrievals from ARM SGP MFRSR Data (Dataset) | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    Aerosol Retrievals from ARM SGP MFRSR Data Title: Aerosol Retrievals from ARM SGP MFRSR Data The Multi-Filter Rotating Shadowband Radiometer (MFRSR) makes precise simultaneous ...

  8. ARM - Campaign Instrument - mfrsr

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    would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : Multifilter Rotating Shadowband Radiometer (MFRSR) Instrument Categories...

  9. Cloud Optical Properties from the Multifilter Shadowband Radiometer...

    Office of Scientific and Technical Information (OSTI)

    Min and Harrison (1996) developed an inversion method to infer the optical depth of liquid ... Multifilter Rotating Shadowband Radiometer (MFRSR) measurements (Harrison et al. 1994). ...

  10. Multi-Filter Rotating Shadowband Radiometers Mentor Report and Baseline Surface Radiation Network Submission Status

    SciTech Connect (OSTI)

    Hodges, G.

    2005-03-18

    There are currently twenty-four Multi-Filter Rotating Shadowband Radiometers (MFRSR) operating within Atmospheric Radiation Measurement (ARM). Eighteen are located within the Southern Great Plains (SGP) region, there is one at each of the North Slope of Alaska (NSA) and Tropical Western Pacific (TWP) sites, and one is part of the instrumentation of the ARM Mobile Facility. At this time there are four sites, all extended facilities within the SGP, that are equipped for a MFRSR but do not have one due to instrument failure and a lack of spare instruments. In addition to the MFRSRs, there are three other MFRSR derived instruments that ARM operates. They are the Multi-Filter Radiometer (MFR), the Normal Incidence Multi-Filter Radiometer (NIMFR) and the Narrow Field of View (NFOV) radiometer. All are essentially just the head of a MFRSR used in innovative ways. The MFR is mounted on a tower and pointed at the surface. At the SGP Central Facility there is one at ten meters and one at twenty-five meters. The NSA has a MFR at each station, both at the ten meter level. ARM operates three NIMFRs; one is at the SGP Central Facility and one at each of the NSA stations. There are two NFOVs, both at the SGP Central Facility. One is a single channel (870) and the other utilizes two channels (673 and 870).

  11. On Correction of Diffuse Radiation Measured by MFRSR

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    On Correction of Diffuse Radiation Measured by MFRSR T. B. Zhuravleva Institute of Atmospheric Optics, SB RAS Tomsk, Russia M. A. Sviridenkov and P. P. Anikin A. M. Obukhov Institute of Atmospheric Physics, RAS Moscow, Russia Introduction The multi-filter rotated shadowband radiometer (MFRSR) provides spectral direct, diffuse, and total horizontal solar irradiance measurements. Because the MFRSR's receiver has a non-Lambertian response, for a correct interpretation of measured radiation an

  12. ARM - Campaign Instrument - uv-mfrsr

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    mfrsr Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : Ultraviolet Multifilter Rotating Shadowband Radiometer (UV-MFRSR) Instrument Categories Radiometric Campaigns Aerosol IOP [ Download Data ] Southern Great Plains, 2003.05.01 - 2003.05.31 Aerosol Lidar Validation Experiment - ALIVE [ Download Data ] Southern Great Plains, 2005.09.12 - 2005.09.22 Primary Measurements Taken The following measurements are those considered

  13. Aerosol Retrievals from ARM SGP MFRSR Data

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Alexandrov, Mikhail

    2008-01-15

    The Multi-Filter Rotating Shadowband Radiometer (MFRSR) makes precise simultaneous measurements of the solar direct normal and diffuse horizontal irradiances at six wavelengths (nominally 415, 500, 615, 673, 870, and 940 nm) at short intervals (20 sec for ARM instruments) throughout the day. Time series of spectral optical depth are derived from these measurements. Besides water vapor at 940 nm, the other gaseous absorbers within the MFRSR channels are NO2 (at 415, 500, and 615 nm) and ozone (at 500, 615, and 670 nm). Aerosols and Rayleigh scattering contribute atmospheric extinction in all MFRSR channels. Our recently updated MFRSR data analysis algorithm allows us to partition the spectral aerosol optical depth into fine and coarse modes and to retrieve the fine mode effective radius. In this approach we rely on climatological amounts of NO2 from SCIAMACHY satellite retrievals and use daily ozone columns from TOMS.

  14. ARM - PI Product - Aerosol Retrievals from ARM SGP MFRSR Data

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    ProductsAerosol Retrievals from ARM SGP MFRSR Data ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Aerosol Retrievals from ARM SGP MFRSR Data The Multi-Filter Rotating Shadowband Radiometer (MFRSR) makes precise simultaneous measurements of the solar direct normal and diffuse horizontal irradiances at six wavelengths (nominally 415, 500, 615, 673, 870, and 940 nm) at short intervals (20 sec for ARM

  15. ARM - Site Instruments

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    Sky Imager Cloud Properties, Radiometric Not Online MFRIRT Multifilter Radiometer and Infrared Thermometer Radiometric MFRSR Multifilter Rotating Shadowband Radiometer...

  16. Rotating shadowband radiometer development and analysis of spectral shortwave data

    SciTech Connect (OSTI)

    Michalsky, J.; Harrison, L.; Min, Q.

    1996-04-01

    Our goals in the Atmospheric Radiation Measurement (ARM) Program are improved measurements of spectral shortwave radiation and improved techniques for the retrieval of climatologically sensitive parameters. The multifilter rotating shadowband radiometer (MFRSR) that was developed during the first years of the ARM program has become a workhorse at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site, and it is widely deployed in other climate programs. We have spent most of our effort this year developing techniques to retrieve column aerosol, water vapor, and ozone from direct beam spectral measurements of the MFRSR. Additionally, we have had some success in calculating shortwave surface diffuse spectral irradiance. Using the surface albedo and the global irradiance, we have calculated cloud optical depths. From cloud optical depth and liquid water measured with the microwave radiometer, we have calculated effective liquid cloud particle radii. The rest of the text will provide some detail regarding each of these efforts.

  17. Cloud Optical Properties from the Multifilter Shadowband Radiometer (MFRSRCLDOD). An ARM Value-Added Product

    SciTech Connect (OSTI)

    Turner, D. D.; McFarlane, S. A.; Riihimaki, L.; Shi, Y.; Lo, C.; Min, Q.

    2014-02-01

    The microphysical properties of clouds play an important role in studies of global climate change. Observations from satellites and surface-based systems have been used to infer cloud optical depth and effective radius. Min and Harrison (1996) developed an inversion method to infer the optical depth of liquid water clouds from narrow band spectral Multifilter Rotating Shadowband Radiometer (MFRSR) measurements (Harrison et al. 1994). Their retrieval also uses the total liquid water path (LWP) measured by a microwave radiometer (MWR) to obtain the effective radius of the warm cloud droplets. Their results were compared with Geostationary Operational Environmental Satellite (GOES) retrieved values at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site (Min and Harrison 1996). Min et al. (2003) also validated the retrieved cloud optical properties against in situ observations, showing that the retrieved cloud effective radius agreed well with the in situ forward scattering spectrometer probe observations. The retrieved cloud optical properties from Min et al. (2003) were used also as inputs to an atmospheric shortwave model, and the computed fluxes were compared with surface pyranometer observations.

  18. ARM: Multi-Filter Radiometer (MFR): upwelling irradiance at 3...

    Office of Scientific and Technical Information (OSTI)

    Multi-Filter Radiometer (MFR): upwelling irradiance at 3-meter height Title: ARM: Multi-Filter Radiometer (MFR): upwelling irradiance at 3-meter height Multi-Filter Radiometer ...

  19. ARM - Campaign Instrument - mfrsr-wv1mich

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    mich Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : MFRSR-WV-Michalsky1 (MFRSR-WV1MICH) Instrument...

  20. ARM - Campaign Instrument - mfrsr-wv1barn

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    barn Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : MFRSR Water-Vapor Barnard Algorithm (MFRSR-WV1BARN)...

  1. Bench-Scale Cross Flow Filtration of

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    aerosol occurrences between the two sites. In the case of aerosols, each site fielded a Multi-filter Rotating Shadowband Radiometer (MFRSR) used to infer aerosol optical thickness...

  2. Newsletter Southern Great Plains

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... MFRSR Calibration Capabilities. The SGP recently acquired from Pacific Northwest National Laboratory equipment needed to calibrate Multi-Filter Rotating Shadowband Radiometers ...

  3. Aerosol Optical Depth Value-Added Product Report

    SciTech Connect (OSTI)

    Koontz, A; Hodges, G; Barnard, J; Flynn, C; Michalsky, J

    2013-03-17

    This document describes the process applied to retrieve aerosol optical depth (AOD) from multifilter rotating shadowband radiometers (MFRSR) and normal incidence multifilter radiometers (NIMFR) operated at the ARM Climate Research Facility’s ground-based facilities.

  4. Automated Algorithm for MFRSR Data Analysis

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Automated Algorithm for MFRSR Data Analysis M. D. Alexandrov and B. Cairns Columbia University and National Aeronautics and Space Administration Goddard Institute for Space Studies New York, New York A. A. Lacis and B. E. Carlson National Aeronautics and Space Administration Goddard Institute for Space Studies New York, New York A. Marshak National Aeronautics and Space Administration Goddard Space Flight Center Greenbelt, Maryland We present a substantial upgrade of our previously developed

  5. Technical progress report: Completion of spectral rotating shadowband radiometers and analysis of atmospheric radiation measurement spectral shortwave data

    SciTech Connect (OSTI)

    Michalsky, J.; Harrison, L.

    1996-04-01

    Our goal in the Atmospheric Radiation Measurement (ARM) Program is the improvement of radiation models used in general circulation models (GCMs), especially in the shortwave, (1) by providing improved shortwave radiometric measurements for the testing of models and (2) by developing methods for retrieving climatologically sensitive parameters that serve as input to shortwave and longwave models. At the Atmospheric Sciences Research Center (ASRC) in Albany, New York, we are acquiring downwelling direct and diffuse spectral irradiance, at six wavelengths, plus downwelling broadband longwave, and upwelling and downwelling broadband shortwave irradiances that we combine with National Weather Service surface and upper air data from the Albany airport as a test data set for ARM modelers. We have also developed algorithms to improve shortwave measurements made at the Southern Great Plains (SGP) ARM site by standard thermopile instruments and by the multifilter rotating shadowband radiometer (MFRSR) based on these Albany data sets. Much time has been spent developing techniques to retrieve column aerosol, water vapor, and ozone from the direct beam spectral measurements of the MFRSR. Additionally, we have had success in calculating shortwave surface albedo and aerosol optical depth from the ratio of direct to diffuse spectral reflectance.

  6. ARM - PI Product - 1.6 Micron MFRSR

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Products1.6 Micron MFRSR ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : 1.6 Micron MFRSR 1.6 Micron MFRSR test data set Data Details Contact Joseph Michalsky Cooperative Institute for Research in Environmental Sciences joseph.michalsky@noaa.gov (303) 497-6360 325 Broadway R/GMD Boulder, CO 80305 US Resource(s) Data Directory ReadMe Site Information SGP

  7. MFRSR Head Refurbishment, Data Logger Upgrade and Calibration Improvements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    MFRSR Head Refurbishment, Data Logger Upgrade and Calibration Improvements Gary Hodges, CIRES/NOAA and John Schmelzer, PNL gary.hodges@noaa.gov, john.schmelzer@pnl.gov 17th Annual ARM Science Team Meeting 26-30 March 2006 Monterey, CA Head Refurbishment The Process Includes: * New filter detectors * Relocate internal thermistors * New connectors * Gain resistors moved to head * Improved insulation The Finished Heads: * Are lamp calibrated * Have filter profiles measured * Cosine characterized *

  8. Failure and Redemption of Multifilter Rotating Shadowband Radiometer...

    Office of Scientific and Technical Information (OSTI)

    Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) and Southern Great ... Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) and Southern Great ...

  9. ARM - Datastreams - mfrsraux

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Datastreamsmfrsraux Documentation Data Quality Plots Citation DOI: 10.5439/1025226 [ What is this? ] Generate Citation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Datastream : MFRSRAUX Auxiliary data for the ARM Multi-Filter Rotating Shadowband Radiometer (MFRSR) Active Dates 2010.11.03 - 2016.09.02 Originating Instrument Multifilter Rotating Shadowband Radiometer (MFRSR) Measurements Only measurements

  10. 1

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    Developments in Multi-Filter Rotating Shadowband Radiometer Data Analysis M. Alexandrov and B. Cairns Columbia University New York, New York A.A. Lacis and B.E. Carlson National Aeronautics and Space Administration-Goddard Institute for Space Studies New York, New York Introduction We present further development of our analysis algorithm (Alexandrov et al. 2005) for multi-filter rotating shadowband radiometer (MFRSR) data. The new additions include a study of MFRSR retrievals sensitivity to

  11. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Multi-Filter Rotating Shadowband Radiometer - A Look Ahead G. Hodges Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder, Colorado Introduction The multi-filter rotating shadowband radiometer (MFRSR) is one of the Atmospheric Radiation Measurement (ARM) Program's original instruments. As atmospheric research has advanced, the ways in which the MFRSR has been used have increased, along with an ever advancing desire from the scientific community for well

  12. DISCLAIMER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    59 Multifilter Rotating Shadowband Radiometer (MFRSR) Handbook With subsections for the following derivative instruments: Multifilter Radiometer (MFR) Normal Incidence Multifilter Radiometer (NIMFR) GB Hodges JJ Michalsky January 2011 Work supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research GB Hodges and JJ Michalsky, January 2011, DOE/SC-ARM/TR-059 iii Acronyms and Abbreviations AMF ARM Mobile Facility ARM Atmospheric Radiation

  13. Research Highlight

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    Preview of TWP MFRSR Data Submitter: Chuang, C., Lawrence Livermore National Laboratory Area of Research: Radiation Processes Working Group(s): Radiative Processes Journal Reference: N/A Figure 1. MFRSR data from the TWP site (97/09/10) Figure 2. Aerosol optical depth and Angstrom exponent Figure 3. Water vapor derived from MFRSR and MWR Key contributors to this work are Jim Barnard and Will Shaw. The Multi-Filter Rotating Shadowband Radiometer (MFRSR) is a ground-based radiometer that uses

  14. 1

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    Fine and Coarse Mode Aerosols in Southern Great Plains Multi-Filter Rotating Shadowband Radiometer Datasets M. Alexandrov and B. Cairns Columbia University New York, New York M. Alexandrov, B E. Carlson, A.A. Lacis, and B. Cairns National Aeronautics and Space Administration Goddard Institute for Space Studies New York, New York Introduction We present results obtained using the new version of the multi-filter rotating shadowband radiometer (MFRSR) data analysis algorithm (Alexandrov et al.

  15. Integrated Study of MFRSR-derived Parameters of Atmospheric Aerosols and Trace Gases Over the ARM CART Site Extended Facili...

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    Integrated Study of MFRSR-Derived Parameters of Atmospheric Aerosols and Trace Gases Over the ARM CART Site Extended Facilities - Comparison with Satellite and Other Ground-Based Measurements M. D. Alexandrov and B. Cairns Columbia University National Aeronautics and Space Administration Goddard Institute for Space Studies New York, New York A. A. Lacis and B. E. Carlson National Aeronautics and Space Administration Goddard Institute for Space Studies New York, New York Comparison of SGP MFRSR

  16. harrison-98.pdf

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Analysis of Rotating Shadowband Spectroradiometer (RSS) Data L. C. Harrison, J. J. Michalsky, Q. Min, and M. Beauharnois Atmospheric Sciences Research Center State University of New York Albany, New York Introduction The rotating shadowband spectroradiometer (RSS, shown in Figure 1) is our most recently developed instrument. It can be thought of as a 512-channel multifilter rotating shadow- band radiometer (MFRSR) spanning the wavelength range 360 nm to 1050 nm. (a) This portion of the shortwave

  17. Section 85

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    i ' -ln I i I 0 i *µ%c i µ, c i Wm &2 c i NO 2 O 3 NO 2 c i c i NO 2 Session Papers 379 (1) Retrieval of Aerosol Optical Depth, Aerosol Size Distribution Parameters, Ozone and Nitrogen Dioxide Column Amounts from Multifilter Rotating Shadowband Radiometer Data M. Alexandrov, A. A. Lacis, B. E. Carlson and B. Cairns National Aeronautics and Space Administration Goddard Institute for Space Studies New York, New York Introduction The MultiFilter Rotating Shadowband Radiometer (MFRSR)

  18. ARM - Site Instruments

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    InactiveInstruments NSA Related Links Virtual Tour Facilities and Instruments Barrow Atqasuk Oliktok Point (AMF3) ES&H Guidance Statement Operations Science Field Campaigns Visiting the Site NSA Fact Sheet Images Information for Guest Scientists Contacts Instruments : Central Facility, Atqasuk AK Active Retired Active instruments are currently deployed at fixed or mobile facilities or are available through the ARM Aerial Facility. MFRSR Multifilter Rotating Shadowband Radiometer Radiometric

  19. ARM - Publications: Science Team Meeting Documents

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    Evidence for Aerosol Effects on AERI Clear-Sky Radiance at the SGP Ma, Y., and Ellingson, R.G., University of Maryland Ninth Atmospheric Radiation Measurement (ARM) Science Team Meeting The Atmospheric Emitted Radiance Interferometer (AERI) Line-by-Line Radiative Transfer Model (LBLRTM) Quality Measurement Experiment (QME) 10-micron window residuals have been examined relative to the Multifilter Rotating Shadowband Radiometer (MFRSR) 0.87-micron optical depth for clear-sky periods during

  20. min-98.pdf

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    Comparison of Model-Predicted Total Shortwave with Measurements Under Overcast Cloud Conditions Q. Min and L. C. Harrison Atmospheric Sciences Research Center State University of New York at Albany Albany, New York Abstract We use surface measurements at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site made with the multifilter rotating shadowband radiometer (MFRSR) and microwave radiometer (MWR) to obtain time-series of cloud optical depths and mean effective droplet

  1. treadwell-98.pdf

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    7 New Broadband Shortwave Solar Radiation Data Collection System for the Southern Great Plains J. A. Treadwell, T. L. Stoffel, and I. Reda National Renewable Energy Laboratory Golden, Colorado Background To improve the data recovery from the Solar and Infrared Radiation Observing System (SIROS), a new data logging system was needed. Experience had shown the original multifilter rotating shadowband radiometer (MFRSR)-based logger and in-line amplifiers were unreliable and difficult to maintain.

  2. Surface based remote sensing of aerosol-cloud interactions

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    Surface based remote sensing of aerosol-cloud interactions Feingold, Graham NOAA/Environmental Technology Laboratory Frisch, Shelby NOAA/Environmental Technology Laboratory Min, Qilong State University of New York at Albany Category: Cloud Properties We will present an analysis of the effect of aerosol on clouds at the Southern Great Plains ARM site. New methods for retrieving cloud droplet effective radius with radar (MMCR), multifilter rotating shadowband radiometer (MFRSR), and microwave

  3. ARM - Instrument - mfrsr

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    Lack of spare instruments and replacement parts were the primary reasons for the slow degradation. Around 2005, it was decided to bring the network back to full capacity. After ...

  4. ARM - Datastreams - mfrsr

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    Datastreamsmfrsr Documentation Data Quality Plots Citation DOI: 10.54391023898 What is this? Generate Citation ARM Data Discovery Browse Data Comments? We would love to hear ...

  5. Aerosol Optical Depth Value-Added Product for the SAS-He Instrument

    SciTech Connect (OSTI)

    Ermold, B; Flynn, CJ; Barnard, J

    2013-11-27

    The Shortwave Array Spectroradiometer – Hemispheric (SAS-He) is a ground-based, shadowband instrument that measures the direct and diffuse solar irradiance. In this regard, the instrument is similar to the Multi-Filter Rotating Shadowband Radiometer (MFRSR) – an instrument that has been in the ARM suite of instruments for more than 15 years. However, the two instruments differ significantly in wavelength resolution and range. In particular, the MFRSR only observes the spectrum in six discrete wavelength channels of about 10 nm width from 415 to 940 nm. The SAS-He, in contrast, incorporates two fiber-coupled grating spectrometers: a Si CCD spectrometer with over 2000 pixels covering the range from 325-1040 nm with ~ 2.5 nm resolution ,and an InGaAs array spectrometer with 256 pixels covering the wavelength range from 960-1700 nm with ~ 6 nm resolution.

  6. Retrieval of Areal-averaged Spectral Surface Albedo from Transmission Data Alone: Computationally Simple and Fast Approach

    SciTech Connect (OSTI)

    Kassianov, Evgueni I.; Barnard, James C.; Flynn, Connor J.; Riihimaki, Laura D.; Michalsky, Joseph; Hodges, G. B.

    2014-10-25

    We introduce and evaluate a simple retrieval of areal-averaged surface albedo using ground-based measurements of atmospheric transmission alone at five wavelengths (415, 500, 615, 673 and 870nm), under fully overcast conditions. Our retrieval is based on a one-line semi-analytical equation and widely accepted assumptions regarding the weak spectral dependence of cloud optical properties, such as cloud optical depth and asymmetry parameter, in the visible and near-infrared spectral range. To illustrate the performance of our retrieval, we use as input measurements of spectral atmospheric transmission from Multi-Filter Rotating Shadowband Radiometer (MFRSR). These MFRSR data are collected at two well-established continental sites in the United States supported by the U.S. Department of Energys (DOEs) Atmospheric Radiation Measurement (ARM) Program and National Oceanic and Atmospheric Administration (NOAA). The areal-averaged albedos obtained from the MFRSR are compared with collocated and coincident Moderate Resolution Imaging Spectroradiometer (MODIS) white-sky albedo. In particular, these comparisons are made at four MFRSR wavelengths (500, 615, 673 and 870nm) and for four seasons (winter, spring, summer and fall) at the ARM site using multi-year (2008-2013) MFRSR and MODIS data. Good agreement, on average, for these wavelengths results in small values (?0.01) of the corresponding root mean square errors (RMSEs) for these two sites. The obtained RMSEs are comparable with those obtained previously for the shortwave albedos (MODIS-derived versus tower-measured) for these sites during growing seasons. We also demonstrate good agreement between tower-based daily-averaged surface albedos measured for nearby overcast and non-overcast days. Thus, our retrieval originally developed for overcast conditions likely can be extended for non-overcast days by interpolating between overcast retrievals.

  7. How Well Can We Estimate Areal-Averaged Spectral Surface Albedo from Ground-Based Transmission in an Atlantic Coastal Area?

    SciTech Connect (OSTI)

    Kassianov, Evgueni I.; Barnard, James C.; Flynn, Connor J.; Riihimaki, Laura D.; Marinovici, Maria C.

    2015-10-15

    Areal-averaged albedos are particularly difficult to measure in coastal regions, because the surface is not homogenous, consisting of a sharp demarcation between land and water. With this difficulty in mind, we evaluate a simple retrieval of areal-averaged surface albedo using ground-based measurements of atmospheric transmission alone under fully overcast conditions. To illustrate the performance of our retrieval, we find the areal-averaged albedo using measurements from the Multi-Filter Rotating Shadowband Radiometer (MFRSR) at five wavelengths (415, 500, 615, 673, and 870 nm). These MFRSR data are collected at a coastal site in Graciosa Island, Azores supported by the U.S. Department of Energy’s (DOE’s) Atmospheric Radiation Measurement (ARM) Program. The areal-averaged albedos obtained from the MFRSR are compared with collocated and coincident Moderate Resolution Imaging Spectroradiometer (MODIS) white-sky albedo at four nominal wavelengths (470, 560, 670 and 860 nm). These comparisons are made during a 19-month period (June 2009 - December 2010). We also calculate composite-based spectral values of surface albedo by a weighted-average approach using estimated fractions of major surface types observed in an area surrounding this coastal site. Taken as a whole, these three methods of finding albedo show spectral and temporal similarities, and suggest that our simple, transmission-based technique holds promise, but with estimated errors of about ±0.03. Additional work is needed to reduce this uncertainty in areas with inhomogeneous surfaces.

  8. Final Report for Grant DE-FG02-90ER61072

    SciTech Connect (OSTI)

    Lee Harrison

    2006-02-20

    This is the final report for the work done by our research group at the Atmospheric Sciences Research Center for the US DOE Atmopheric Radiation Measurement (ARM) Program. We were involved from the beginning of the ARM effort; we designed the Multi-filter Rotating Shadowband Spectroradiometer (MFRSR) which was widely deployed (and still operational in ARM) and through the years did a wide variety of data analysis on the returned data from these instruments. We also developed the Rotating Shadowband Spectroradiometer, which ARM deployed and also still deploys. Many scientific papers have been written using the data from these instruments, and the ongoing data streams remain part of the current ARM effort. Earlier reports contain our progress from previous grant periods, this report covers the last period and provides references to published work.

  9. Diamagnetism of rotating plasma

    SciTech Connect (OSTI)

    Young, W. C.; Hassam, A. B.; Romero-Talamas, C. A.; Ellis, R. F.; Teodorescu, C.

    2011-11-15

    Diamagnetism and magnetic measurements of a supersonically rotating plasma in a shaped magnetic field demonstrate confinement of plasma pressure along the magnetic field resulting from centrifugal force. The Grad-Shafranov equation of ideal magnetohydrodynamic force balance, including supersonic rotation, is solved to confirm that the predicted angular velocity is in agreement with spectroscopic measurements of the Doppler shifts.

  10. Rotatable shear plate interferometer

    DOE Patents [OSTI]

    Duffus, Richard C.

    1988-01-01

    A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.

  11. CONTROL ROD ROTATING MECHANISM

    DOE Patents [OSTI]

    Baumgarten, A.; Karalis, A.J.

    1961-11-28

    A threaded rotatable shaft is provided which rotates in response to linear movement of a nut, the shaft being surrounded by a pair of bellows members connected to either side of the nut to effectively seal the reactor from leakage and also to store up energy to shut down the reactor in the event of a power failure. (AEC)

  12. Rotation sensor switch

    DOE Patents [OSTI]

    Sevec, John B.

    1978-01-01

    A protective device to provide a warning if a piece of rotating machinery slows or stops comprises a pair of hinged weights disposed to rotate on a rotating shaft of the equipment. When the equipment is rotating, the weights remain in a plane essentially perpendicular to the shaft and constitute part of an electrical circuit that is open. When the shaft slows or stops, the weights are attracted to a pair of concentric electrically conducting disks disposed in a plane perpendicular to the shaft and parallel to the plane of the weights when rotating. A disk magnet attracts the weights to the electrically conducting plates and maintains the electrical contact at the plates to complete an electrical circuit that can then provide an alarm signal.

  13. Rotatable seal assembly. [Patent application; rotating targets

    DOE Patents [OSTI]

    Logan, C.M.; Garibaldi, J.L.

    1980-11-12

    An assembly is provided for rotatably supporting a rotor on a stator so that vacuum chambers in the rotor and stator remain in communication while the chambers are sealed from ambient air, which enables the use of a ball bearing or the like to support most of the weight of the rotor. The apparatus includes a seal device mounted on the rotor to rotate therewith, but shiftable in position on the rotor while being sealed to the rotor as by an O-ring. The seal device has a flat face that is biased towards a flat face on the stator, and pressurized air is pumped between the faces to prevent contact between them while spacing them a small distance apart to avoid the inflow of large amounts of air between the faces and into the vacuum chambers.

  14. On rapid plasma rotation

    SciTech Connect (OSTI)

    Helander, P.

    2007-10-15

    The conditions under which rapid plasma rotation may occur in a general three-dimensional magnetic field with flux surfaces, such as that of a stellarator, are investigated. Rotation velocities comparable to the ion thermal speed are found to be attainable only in magnetic fields whose strength B depends on the arc length l along the field in approximately the same way for all field lines on each flux surface {psi}, i.e., B{approx_equal}f({psi},l). Moreover, it is shown that the rotation must be in the direction of the vector {nabla}{psi}x{nabla}B.

  15. Rotating arc spark plug

    DOE Patents [OSTI]

    Whealton, John H.; Tsai, Chin-Chi

    2003-05-27

    A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

  16. Rotational rate sensor

    DOE Patents [OSTI]

    Hunter, Steven L. (Livermore, CA)

    2002-01-01

    A rate sensor for angular/rotational acceleration includes a housing defining a fluid cavity essentially completely filled with an electrolyte fluid. Within the housing, such as a toroid, ions in the fluid are swept during movement from an excitation electrode toward one of two output electrodes to provide a signal for directional rotation. One or more ground electrodes within the housing serve to neutralize ions, thus preventing any effect at the other output electrode.

  17. Electromagnetic rotational actuation.

    SciTech Connect (OSTI)

    Hogan, Alexander Lee

    2010-08-01

    There are many applications that need a meso-scale rotational actuator. These applications have been left by the wayside because of the lack of actuation at this scale. Sandia National Laboratories has many unique fabrication technologies that could be used to create an electromagnetic actuator at this scale. There are also many designs to be explored. In this internship exploration of the designs and fabrications technologies to find an inexpensive design that can be used for prototyping the electromagnetic rotational actuator.

  18. Research Highlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    developed, which combines downwelling radiative fluxes at 415 nm, measured by a multi-filter rotating shadowband radiometer and liquid water path retrievals from a microwave...

  19. Rotating superconductor magnet for producing rotating lobed magnetic field lines

    DOE Patents [OSTI]

    Hilal, Sadek K.; Sampson, William B.; Leonard, Edward F.

    1978-01-01

    This invention provides a rotating superconductor magnet for producing a rotating lobed magnetic field, comprising a cryostat; a superconducting magnet in the cryostat having a collar for producing a lobed magnetic field having oppositely directed adjacent field lines; rotatable support means for selectively rotating the superconductor magnet; and means for energizing the superconductor magnet.

  20. alexandrov-99.PDF

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Validation of MFRSR Data Analysis: Comparison with the Langley Approach M. D. Alexandrov and B. Cairns Columbia University National Aeronautics and Space Administration Goddard Institute for Space Studies New York, New York A. A. Lacis and B. E. Carlson National Aeronautics and Space Administration Goddard Institute for Space Studies New York, New York Introduction In the present study, we validate the retrieval algorithm (Alexandrov et al. 1998a, 1998b, 1998c) for processing of Multifilter

  1. Rotating Aperture System

    DOE Patents [OSTI]

    Rusnak, Brian; Hall, James M.; Shen, Stewart; Wood, Richard L.

    2005-01-18

    A rotating aperture system includes a low-pressure vacuum pumping stage with apertures for passage of a deuterium beam. A stator assembly includes holes for passage of the beam. The rotor assembly includes a shaft connected to a deuterium gas cell or a crossflow venturi that has a single aperture on each side that together align with holes every rotation. The rotating apertures are synchronized with the firing of the deuterium beam such that the beam fires through a clear aperture and passes into the Xe gas beam stop. Portions of the rotor are lapped into the stator to improve the sealing surfaces, to prevent rapid escape of the deuterium gas from the gas cell.

  2. Rotating bubble membrane radiator

    DOE Patents [OSTI]

    Webb, Brent J.; Coomes, Edmund P.

    1988-12-06

    A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

  3. Rotating flexible drag mill

    DOE Patents [OSTI]

    Pepper, W.B.

    1984-05-09

    A rotating parachute for decelerating objects travelling through atmosphere at subsonic or supersonic deployment speeds includes a circular canopy having a plurality of circumferentially arranged flexible panels projecting radially from a solid central disk. A slot extends radially between adjacent panels to the outer periphery of the canopy. Upon deployment, the solid disk diverts air radially to rapidly inflate the panels into a position of maximum diameter. Air impinging on the panels adjacent the panel slots rotates the parachute during its descent. Centrifugal force flattens the canopy into a constant maximum diameter during terminal descent for maximum drag and deceleration.

  4. Rotating shielded crane system

    SciTech Connect (OSTI)

    Commander, John C.

    1988-01-01

    A rotating, radiation shielded crane system for use in a high radiation test cell, comprises a radiation shielding wall, a cylindrical ceiling made of radiation shielding material and a rotatable crane disposed above the ceiling. The ceiling rests on an annular ledge intergrally attached to the inner surface of the shielding wall. Removable plugs in the ceiling provide access for the crane from the top of the ceiling into the test cell. A seal is provided at the interface between the inner surface of the shielding wall and the ceiling.

  5. Rotatable stem and lock

    DOE Patents [OSTI]

    Deveney, J.E.; Sanderson, S.N.

    1981-10-27

    A valve stem and lock is disclosed which includes a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

  6. Troubleshooting rotating equipment

    SciTech Connect (OSTI)

    Wong, R.F. )

    1992-10-01

    This paper reports that equipment problems in a Peruvian refinery illustrate the process engineer's role as a troubleshooter. Examples show that rotating equipment problems can stem from mechanical or process factors and involve both inspection/maintenance specialists and process engineers.

  7. Rotatable stem and lock

    DOE Patents [OSTI]

    Deveney, Joseph E.; Sanderson, Stephen N.

    1984-01-01

    A valve stem and lock include a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

  8. Rotatable seal assembly

    DOE Patents [OSTI]

    Logan, Clinton M.; Garibaldi, Jack L.

    1982-01-01

    An assembly is provided for rotatably supporting a rotor on a stator so that vacuum chambers in the rotor and stator remain in communication while the chambers are sealed from ambient air, which enables the use of a ball bearing or the like to support most of the weight of the rotor. The apparatus includes a seal device mounted on the rotor to rotate therewith, but shiftable in position on the rotor while being sealed to the rotor as by an O-ring. The seal device has a flat face that is biased towards a flat face on the stator, and pressurized air is pumped between the faces to prevent contact between them while spacing them a small distance apart to avoid the inflow of large amounts of air between the faces and into the vacuum chambers.

  9. Rotating plug bearing and seal

    DOE Patents [OSTI]

    Wade, Elman E.

    1977-01-01

    A bearing and seal structure for nuclear reactors utilizing rotating plugs above the nuclear reactor vessel. The structure permits lubrication of bearings and seals of the rotating plugs without risk of the lubricant draining into the reactor vessel below. The structure permits lubrication by utilizing a rotating outer race bearing.

  10. ROTATING PLASMA DEVICE

    DOE Patents [OSTI]

    Boyer, K.; Hammel, J.E.; Longmire, C.L.; Nagle, D.E.; Ribe, F.L.; Tuck, J.L.

    1961-10-24

    ABS>A method and device are described for obtaining fusion reactions. The basic concept is that of using crossed electric and magnetic fields to induce a plasma rotation in which the ionized particles follow a circumferential drift orbit on wldch a cyclotron mode of motion is superimposed, the net result being a cycloidal motion about the axis of symmetry. The discharge tube has a radial electric field and a longitudinal magnetic field. Mirror machine geometry is utilized. The device avoids reliance on the pinch effect and its associated instability problems. (AEC)

  11. Sample rotating turntable kit for infrared spectrometers

    DOE Patents [OSTI]

    Eckels, Joel Del (Livermore, CA); Klunder, Gregory L. (Oakland, CA)

    2008-03-04

    An infrared spectrometer sample rotating turntable kit has a rotatable sample cup containing the sample. The infrared spectrometer has an infrared spectrometer probe for analyzing the sample and the rotatable sample cup is adapted to receive the infrared spectrometer probe. A reflectance standard is located in the rotatable sample cup. A sleeve is positioned proximate the sample cup and adapted to receive the probe. A rotator rotates the rotatable sample cup. A battery is connected to the rotator.

  12. Rotating drum filter

    DOE Patents [OSTI]

    Anson, Donald

    1990-01-01

    A perforated drum (10) rotates in a coaxial cylindrical housing (18) having three circumferential ports (19,22,23), and an axial outlet (24) at one end. The axis (11) is horizontal. A fibrous filter medium (20) is fed through a port (19) on or near the top of the housing (81) by a distributing mechanism (36) which lays a uniform mat (26) of the desired thickness onto the rotating drum (10). This mat (26) is carried by the drum (10) to a second port (23) through which dirty fluid (13) enters. The fluid (13) passes through the filter (26) and the cleaned stream (16) exits through the open end (15) of the drum (10) and the axial port (24) in the housing (18). The dirty filter material (20) is carried on to a third port (22) near the bottom of the housing (18) and drops into a receiver (31) from which it is continuously removed, cleaned (30), and returned (32) to the charging port (36) at the top. To support the filter mat, the perforated cylinder may carry a series of tines (40), shaped blades (41), or pockets, so that the mat (26) will not fall from the drum (10) prematurely. To minimize risk of mat failure, the fluid inlet port (23) may be located above the horizontal centerline (11).

  13. Digital rotation measurement unit

    DOE Patents [OSTI]

    Sanderson, S.N.

    1983-09-30

    A digital rotation indicator is disclosed for monitoring the position of a valve member having a movable actuator. The indicator utilizes mercury switches adapted to move in cooperation with the actuator. Each of the switches produces an output as it changes state when the actuator moves. A direction detection circuit is connected to the switches to produce a first digital signal indicative of the direction of rotation of the actuator. A count pulse generating circuit is also connected to the switches to produce a second digital pulse signal having count pulses corresponding to a change of state of any of the mercury switches. A reset pulse generating circuit is provided to generate a reset pulse each time a count pulse is generated. An up/down counter is connected to receive the first digital pulse signal and the second digital pulse signal and to count the pulses of the second digital pulse signal either up or down depending upon the instantaneous digital value of the first digital signal whereby a running count indicative of the movement of the actuator is maintained.

  14. DOE/SC-ARM-TR-144

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    4 Multifilter Rotating Shadowband Radiometer Instrument Handbook With subsections for derivative instruments: Multifilter Radiometer (MFR) Normal Incidence Multifilter Radiometer (NIMFR) GB Hodges JJ Michalsky March 2016 DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy,

  15. Surface dimpling on rotating work piece using rotation cutting tool

    DOE Patents [OSTI]

    Bhapkar, Rohit Arun; Larsen, Eric Richard

    2015-03-31

    A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupled to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.

  16. ARM - Evaluation Product - MFRSR-Column Intensive Properties

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ARM Data Discovery Browse Data Documentation Use the Data File Inventory tool to view data availability at the file level. Comments? We would love to hear from you Send...

  17. ARM - Evaluation Product - Cloud Optical Properties from MFRSR...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    operational VAP run at other sites, MFRSRCLDOD is based on the algorithm by Min and Harrison (1996). Users are referred to that documentation for more details: http:...

  18. Precise rotation rates for five slowly rotating A stars

    SciTech Connect (OSTI)

    Gray, David F.

    2014-04-01

    Projected rotation rates of five early A-type slowly rotating stars are measured spectroscopically to a precision of 0.2 km s{sup 1}. A detailed Fourier analysis is done, as well as a comparison of profiles directly. Macroturbulence is needed in addition to rotation to reproduce the profile shapes. An upper limit of ?2 km s{sup 1} is placed on the microturbulence dispersion. Small unexplained differences between the models and the observations are seen in the sidelobe structure of the transforms. The v sin i results are: ? Dra, 26.2; ? Leo, 22.5; ? CMa A, 16.7; ? Gem A, 10.7; o Peg, 6.0 km s{sup 1}. These stars are suitable as standards for measuring rotation using less fundamental methods.

  19. Axial gap rotating electrical machine

    DOE Patents [OSTI]

    None

    2016-02-23

    Direct drive rotating electrical machines with axial air gaps are disclosed. In these machines, a rotor ring and stator ring define an axial air gap between them. Sets of gap-maintaining rolling supports bear between the rotor ring and the stator ring at their peripheries to maintain the axial air gap. Also disclosed are wind turbines using these generators, and structures and methods for mounting direct drive rotating electrical generators to the hubs of wind turbines. In particular, the rotor ring of the generator may be carried directly by the hub of a wind turbine to rotate relative to a shaft without being mounted directly to the shaft.

  20. Cooling system for rotating machine

    DOE Patents [OSTI]

    Gerstler, William Dwight; El-Refaie, Ayman Mohamed Fawzi; Lokhandwalla, Murtuza; Alexander, James Pellegrino; Quirion, Owen Scott; Palafox, Pepe; Shen, Xiaochun; Salasoo, Lembit

    2011-08-09

    An electrical machine comprising a rotor is presented. The electrical machine includes the rotor disposed on a rotatable shaft and defining a plurality of radial protrusions extending from the shaft up to a periphery of the rotor. The radial protrusions having cavities define a fluid path. A stationary shaft is disposed concentrically within the rotatable shaft wherein an annular space is formed between the stationary and rotatable shaft. A plurality of magnetic segments is disposed on the radial protrusions and the fluid path from within the stationary shaft into the annular space and extending through the cavities within the radial protrusions.

  1. Rotation Reversal Bifurcation and Energy Confinement Saturation...

    Office of Scientific and Technical Information (OSTI)

    Rotation Reversal Bifurcation and Energy Confinement Saturation in Tokamak OhmicL-Mode Plasmas Citation Details In-Document Search Title: Rotation Reversal Bifurcation and Energy...

  2. Cloud Optical Properties from the Multi-Filter Shadowband Radiometer...

    Office of Scientific and Technical Information (OSTI)

    public from the National Technical Information Service, Springfield, VA at www.ntis.gov. ... depths larger than approximately 7. The retrieval assumes a single cloud layer consisting ...

  3. Cloud Optical Properties from the Multi-Filter Shadowband Radiometer...

    Office of Scientific and Technical Information (OSTI)

    The Min and Harrison algorithm has been incorporated into an ARM Value-Added Product (VAP) ... As specified by Min and Harrison (1996), the wavelength at 415 nm was chosen due to the ...

  4. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Spectrally Resolved Shortwave Flux at Atmospheric Radiation Measurement Program: History and the Present Status of Rotating Shadowband Spectroradiometer P. Kiedron and J. Schlemmer Atmospheric Sciences Research Center State University of New York at Albany, New York Overview The rotating shadowband spectroradiometer (RSS) implements the same automated shadowbanding technique used by the multi-filter rotating shadowband radiometer. Like the multi-filter rotating shadowband radiometer, it provides

  5. Rotating head and piston engine

    SciTech Connect (OSTI)

    Gomm, T.J.; Messick, N.C.

    1992-07-21

    This patent describes a rotary piston combustion engine. It comprises a housing means, an engine block housing a single toroidal bore, a piston carrier ring spaced outwardly along the entire perimeter of the toroidal bore with at least one finger extending inwardly for piston attachment, a power transfer cylinder, a power output shaft, an auxiliary shaft with driven gearing means meshing with the driving gearing means, a rotating head with windows for piston passage, a trapezoidal porting means in the engine block and in the rotating head, an exhaust port means.

  6. Holder for rotating glass body

    DOE Patents [OSTI]

    Kolleck, Floyd W.

    1978-04-04

    A device is provided for holding and centering a rotating glass body such as a rod or tube. The device includes a tubular tip holder which may be held in a lathe chuck. The device can utilize a variety of centering tips each adapted for a particular configuration, such as a glass O-ring joint or semi-ball joint.

  7. Rotating drum variable depth sampler

    DOE Patents [OSTI]

    Nance, Thomas A.; Steeper, Timothy J.

    2008-07-01

    A sampling device for collecting depth-specific samples in silt, sludge and granular media has three chambers separated by a pair of iris valves. Rotation of the middle chamber closes the valves and isolates a sample in a middle chamber.

  8. Rotation of highly excited nuclei: Mass dependence of rotational damping

    SciTech Connect (OSTI)

    Million, B.; Frattini, S.; Bracco, A.; Leoni, S.; Camera, F.; Blasi, N.; Lo Bianco, G.; Pignanelli, M.; Vigezzi, E.; Herskind, B.; Doessing, T.; Bergstroem, M.; Varmette, P.; Toermaenen, S.; Maj, A.; Kmiecik, M.; Napoli, D. R.; Matsuo, M.

    1999-11-16

    The {gamma}-decay of the continuum has been measured in two mass regions. The excitation function of the continuum decay as well as spectral shape and fractional Doppler shifts are discussed for both {sup 114}Te and {sup 164}Yb compound nuclei, and show the typical features of rotational collective motion. Moreover, in both cases an upper limit of {gamma}{sub rot} is given and the number of decay-paths is determined from the fluctuation analysis method. Simulations based on microscopic calculations of the rotational damping model reproduce quite well the experimental findings for both N{sub path} and the scaling of {gamma}{sub rot} as a function of the mass number.

  9. Rotating concave eddy current probe

    DOE Patents [OSTI]

    Roach, Dennis P. (Albuquerque, NM); Walkington, Phil (Albuquerque, NM); Rackow, Kirk A. (Albuquerque, NM); Hohman, Ed (Albuquerque, NM)

    2008-04-01

    A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

  10. Charged rotating dilaton black strings

    SciTech Connect (OSTI)

    Dehghani, M.H.; Farhangkhah, N.

    2005-02-15

    In this paper we, first, present a class of charged rotating solutions in four-dimensional Einstein-Maxwell-dilaton gravity with zero and Liouville-type potentials. We find that these solutions can present a black hole/string with two regular horizons, an extreme black hole or a naked singularity provided the parameters of the solutions are chosen suitable. We also compute the conserved and thermodynamic quantities, and show that they satisfy the first law of thermodynamics. Second, we obtain the (n+1)-dimensional rotating solutions in Einstein-dilaton gravity with Liouville-type potential. We find that these solutions can present black branes, naked singularities or spacetimes with cosmological horizon if one chooses the parameters of the solutions correctly. Again, we find that the thermodynamic quantities of these solutions satisfy the first law of thermodynamics.

  11. Translation and rotation positioning motor

    DOE Patents [OSTI]

    Schmid, Andreas; Schaff, Oliver

    2005-02-01

    A positioning device provides the capability of moving an object in both a linear and a rotational direction. The positioning device includes a first piezo stack with plural piezo plates that are capable of movement in orthogonal directions with respect to each other. The positioning device further includes a second piezo stack with plural piezo plates that are capable of movement in orthogonal directions with respect to each other. The positioning device also includes a first bearing that is disposed against the first piezo stack. The positioning device further includes a second bearing that is disposed against the second piezo stack. The positioning device also includes a spring element and a fifth bearing that is disposed against the spring element. The first through fifth bearings are disposed around and against the object to be positioned, to provide for positioning of the object in at least one of a linear direction and a rotational direction.

  12. Translation and rotation positioning motor

    DOE Patents [OSTI]

    Schmid, Andreas; Schaff, Oliver

    2006-07-04

    A positioning device provides the capability of moving an object in both a linear and a rotational direction. The positioning device includes a first piezo stack with plural piezo plates that are capable of movement in orthogonal directions with respect to each other. The positioning device further includes a second piezo stack with plural piezo plates that are capable of movement in orthogonal directions with respect to each other. The positioning device also includes a first bearing that is disposed against the first piezo stack. The positioning device further includes a second bearing that is disposed against the second piezo stack. The positioning device also includes a spring element and a fifth bearing that is disposed against the spring element. The first through fifth bearings are disposed around and against the object to be positioned, to provide for positioning of the object in at least one of a linear direction and a rotational direction.

  13. Gravity controlled anti-reverse rotation device

    DOE Patents [OSTI]

    Dickinson, Robert J.; Wetherill, Todd M.

    1983-01-01

    A gravity assisted anti-reverse rotation device for preventing reverse rotation of pumps and the like. A horizontally mounted pawl is disposed to mesh with a fixed ratchet preventing reverse rotation when the pawl is advanced into intercourse with the ratchet by a vertically mounted lever having a lumped mass. Gravitation action on the lumped mass urges the pawl into mesh with the ratchet, while centrifugal force on the lumped mass during forward, allowed rotation retracts the pawl away from the ratchet.

  14. Dual rotating shaft seal apparatus

    DOE Patents [OSTI]

    Griggs, J.E.; Newman, H.J.

    1983-06-16

    The report is directed to apparatus suitable for transferring torque and rotary motion through a wall in a manner which is essentially gas impermeable. The apparatus can be used for pressurizing, agitating, and mixing fluids and features two ferrofluidic, i.e., ferrometic seals. Each seal is disposed on one of two supported shafts and each shaft is operably connected at one end to a gear mechanism and at its other end to an adjustable coupling means which is to be connected to a rotatable shaft extending through a wall through which torque and rotary motion are to be transferred.

  15. Are azobenzenophanes rotation-restricted?

    SciTech Connect (OSTI)

    Ciminelli, Cosimo; Granucci, Giovanni; Persico, Maurizio

    2005-11-01

    We simulated the photoisomerization dynamics of an azobenzenophane with a semiclassical surface hopping approach and a semiempirical reparametrized quantum mechanics/molecular mechanics Hamiltonian. Only one of the two azobenzene chromophores in the molecule is taken into account quantum mechanically: the other one is treated by molecular mechanics. Both n{yields}{pi}* and {pi}{yields}{pi}* excitations are considered. Our results show that the photoisomerization reaction mainly involves the rotation around the N=N double bond. The excited state relaxation features are in qualitative agreement with experimental time-resolved fluorescence results.

  16. Trirotron: triode rotating beam radio frequency amplifier

    DOE Patents [OSTI]

    Lebacqz, Jean V.

    1980-01-01

    High efficiency amplification of radio frequencies to very high power levels including: establishing a cylindrical cloud of electrons; establishing an electrical field surrounding and coaxial with the electron cloud to bias the electrons to remain in the cloud; establishing a rotating electrical field that surrounds and is coaxial with the steady field, the circular path of the rotating field being one wavelength long, whereby the peak of one phase of the rotating field is used to accelerate electrons in a beam through the bias field in synchronism with the peak of the rotating field so that there is a beam of electrons continuously extracted from the cloud and rotating with the peak; establishing a steady electrical field that surrounds and is coaxial with the rotating field for high-energy radial acceleration of the rotating beam of electrons; and resonating the rotating beam of electrons within a space surrounding the second field, the space being selected to have a phase velocity equal to that of the rotating field to thereby produce a high-power output at the frequency of the rotating field.

  17. In-line rotating capacitive torque sensor

    DOE Patents [OSTI]

    Kronberg, J.W.

    1991-09-10

    Disclosed are a method and apparatus for measuring torques developed along a rotating mechanical assembly comprising a rotating inner portion and a stationary outer portion. The rotating portion has an electrically-conductive flexing section fitted between two coaxial shafts in a configuration which varies radially in accordance with applied torque. The stationary portion comprises a plurality of conductive plates forming a surface concentric with and having a diameter slightly larger than the diameter of the rotating portion. The capacitance between the outer, nonrotating and inner, rotating portion varies with changes in the radial configuration of the rotating portion. Signal output varies approximately linearly with torque for small torques, nonlinearly for larger torques. The sensor is preferably surrounded by a conductive shell to minimize electrical interference from external sources. 18 figures.

  18. Inertial measurement unit using rotatable MEMS sensors

    DOE Patents [OSTI]

    Kohler, Stewart M.; Allen, James J.

    2007-05-01

    A MEM inertial sensor (e.g. accelerometer, gyroscope) having integral rotational means for providing static and dynamic bias compensation is disclosed. A bias compensated MEM inertial sensor is described comprising a MEM inertial sense element disposed on a rotatable MEM stage. A MEM actuator drives the rotation of the stage between at least two predetermined rotational positions. Measuring and comparing the output of the MEM inertial sensor in the at least two rotational positions allows for both static and dynamic bias compensation in inertial calculations based on the sensor's output. An inertial measurement unit (IMU) comprising a plurality of independently rotatable MEM inertial sensors and methods for making bias compensated inertial measurements are disclosed.

  19. Inertial measurement unit using rotatable MEMS sensors

    DOE Patents [OSTI]

    Kohler, Stewart M.; Allen, James J.

    2006-06-27

    A MEM inertial sensor (e.g. accelerometer, gyroscope) having integral rotational means for providing static and dynamic bias compensation is disclosed. A bias compensated MEM inertial sensor is described comprising a MEM inertial sense element disposed on a rotatable MEM stage. A MEM actuator for drives the rotation of the stage between at least two predetermined rotational positions. Measuring and comparing the output of the MEM inertial sensor in the at least two rotational positions allows, for both static and dynamic bias compensation in inertial calculations based on the sensor's output. An inertial measurement unit (IMU) comprising a plurality of independently rotatable MEM inertial sensors and methods for making bias compensated inertial measurements are disclosed.

  20. In-line rotating capacitive torque sensor

    DOE Patents [OSTI]

    Kronberg, James W.

    1991-01-01

    A method and apparatus for measuring torques developed along a rotating mechanical assembly comprising a rotating inner portion and a stationary outer portion. The rotating portion has an electrically-conductive flexing section fitted between two coaxial shafts in a configuration which varies radially in accordance with applied torque. The stationary portion comprises a plurality of conductive plates forming a surface concentric with and having a diameter slightly larger than the diameter of the rotating portion. The capacitance between the outer, nonrotating and inner, rotating portion varies with changes in the radial configuration of the rotating portion. Signal output varies approximately linearly with torque for small torques, nonlinearly for larger torques. The sensor is preferably surrounded by a conductive shell to minimize electrical interference from external sources.

  1. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Multi-Filter Rotating Shadowband Radiometers Mentor Report and Baseline Surface Radiation Network Submission Status G. Hodges Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder, Colorado Overview Currently 24 multi-filter rotating shadowband radiometers (MFRSRs) operate within the Atmospheric Radiation Measurement (ARM) Program. Eighteen MFRSRs are located at Southern Great Plains (SGP) site, one is located at each of the North Slope of Alaska (NSA) and

  2. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Microphysical and Optical Properties from Multifilter Rotating Shadowband Radiometers E. Kassianov, J. Barnard, T. Ackerman, C. Flynn, and D. Flynn Pacific Northwest National Laboratory Richland, Washington Introduction Multifilter rotating shadowband radiometers (MFRSRs) provide measurements of the total and diffuse solar irradiances at six wavelengths (415, 500, 615, 673, 870 and 940 nm). Direct solar irradiances are inferred by finding the difference between the two measured irradiances, and

  3. Hidden Rotational Symmetries in Magnetic Domain Patterns

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and magnetization history. Left: A typical speckle pattern from the CoPd multilayer. Color bar at bottom indicates relative intensity. The rotational symmetry of a scattering...

  4. Microfabricated microengine with constant rotation rate

    DOE Patents [OSTI]

    Romero, Louis A. (Albuquerque, NM); Dickey, Fred M. (Albuquerque, NM)

    1999-01-01

    A microengine uses two synchronized linear actuators as a power source and converts oscillatory motion from the actuators into constant rotational motion via direct linkage connection to an output gear or wheel. The microengine provides output in the form of a continuously rotating output gear that is capable of delivering drive torque at a constant rotation to a micromechanism. The output gear can have gear teeth on its outer perimeter for directly contacting a micromechanism requiring mechanical power. The gear is retained by a retaining means which allows said gear to rotate freely. The microengine is microfabricated of polysilicon on one wafer using surface micromachining batch fabrication.

  5. Rotational Electrophoresis of Striped Metallic Microrods (Journal...

    Office of Scientific and Technical Information (OSTI)

    The torque due to polarization has a second order dependence on the electric field ... ELECTRIC FIELDS; ELECTROPHORESIS; ORIENTATION; POLARIZATION; ROTATION; SIMULATION; TORQUE

  6. DEVICE FOR CONVEYING AND ROTATING OBJECTS

    DOE Patents [OSTI]

    Frantz, C.E.; Roslund, J.

    1958-01-21

    A device is described for conveying cylindrical material with a combined rotary and axial motion. The material rides on a series of balls which are retained in a guide plate and rotated by bearing against a rotating drum. The drum has a series of conical sections or grooves cut in its outer surface on which the balls ride. The grooves and balls match in such a way that all the balls are caused to rotate about an axis at an angle to the drum axis. This skewed rotation of the ball imparts a longitudinal as well as a rotary motion to the cylinders being conveyed.

  7. Fragmentation in rotating isothermal protostellar clouds

    SciTech Connect (OSTI)

    Bodenheimer, P.; Tohline, J.E.; Black, D.C.

    1980-01-01

    Results of an extensive set of 3-D hydrodynamic calculations that have been performed to investigate the susceptibility of rotating clouds to gravitational fragmentation are presented. (GHT)

  8. Rotation Reversal Bifurcation and Energy Confinement Saturation...

    Office of Scientific and Technical Information (OSTI)

    Title: Rotation Reversal Bifurcation and Energy Confinement Saturation in Tokamak Ohmic L -Mode Plasmas Authors: Rice, J. E. ; Cziegler, I. ; Diamond, P. H. ; Duval, B. P. ; ...

  9. Areal-averaged and Spectrally-resolved Surface Albedo from Ground-based Transmission Data Alone: Toward an Operational Retrieval

    SciTech Connect (OSTI)

    Kassianov, Evgueni I.; Barnard, James C.; Flynn, Connor J.; Riihimaki, Laura D.; Michalsky, Joseph; Hodges, G. B.

    2014-08-22

    We present here a simple retrieval of the areal-averaged and spectrally resolved surface albedo using only ground-based measurements of atmospheric transmission under fully overcast conditions. Our retrieval is based on a one-line equation and widely accepted assumptions regarding the weak spectral dependence of cloud optical properties in the visible and near-infrared spectral range. The feasibility of our approach for the routine determinations of albedo is demonstrated for different landscapes with various degrees of heterogeneity using three sets of measurements:(1) spectrally resolved atmospheric transmission from Multi-Filter Rotating Shadowband Radiometer (MFRSR) at wavelength 415, 500, 615, 673, and 870 nm, (2) tower-based measurements of local surface albedo at the same wavelengths, and (3) areal-averaged surface albedo at four wavelengths (470, 560, 670 and 860 nm) from collocated and coincident Moderate Resolution Imaging Spectroradiometer (MODIS) observations. These integrated datasets cover both long (2008-2013) and short (April-May, 2010) periods at the ARM Southern Great Plains (SGP) site and the NOAA Table Mountain site, respectively. The calculated root mean square error (RMSE), which is defined here as the root mean squared difference between the MODIS-derived surface albedo and the retrieved area-averaged albedo, is quite small (RMSE≤0.01) and comparable with that obtained previously by other investigators for the shortwave broadband albedo. Good agreement between the tower-based daily averages of surface albedo for the completely overcast and non-overcast conditions is also demonstrated. This agreement suggests that our retrieval originally developed for the overcast conditions likely will work for non-overcast conditions as well.

  10. Spontaneous generation of rotation in tokamak plasmas

    SciTech Connect (OSTI)

    Parra Diaz, Felix

    2013-12-24

    Three different aspects of intrinsic rotation have been treated. i) A new, first principles model for intrinsic rotation [F.I. Parra, M. Barnes and P.J. Catto, Nucl. Fusion 51, 113001 (2011)] has been implemented in the gyrokinetic code GS2. The results obtained with the code are consistent with several experimental observations, namely the rotation peaking observed after an L-H transition, the rotation reversal observed in Ohmic plasmas, and the change in rotation that follows Lower Hybrid wave injection. ii) The model in [F.I. Parra, M. Barnes and P.J. Catto, Nucl. Fusion 51, 113001 (2011)] has several simplifying assumptions that seem to be satisfied in most tokamaks. To check the importance of these hypotheses, first principles equations that do not rely on these simplifying assumptions have been derived, and a version of these new equations has been implemented in GS2 as well. iii) A tokamak cross-section that drives large intrinsic rotation has been proposed for future large tokamaks. In large tokamaks, intrinsic rotation is expected to be very small unless some up-down asymmetry is introduced. The research conducted under this contract indicates that tilted ellipticity is the most efficient way to drive intrinsic rotation.

  11. Experimental and analytical study of rotating cavitation

    SciTech Connect (OSTI)

    Kamijo, Kenjiro; Shimura, Takashi; Tsujimoto, Yoshinobu [National Aerospace Lab., Miyagi (Japan). Kakuda Research Center

    1994-12-31

    This paper describes experimental and analytical results of rotating cavitation. There are four major sections in this paper. The first section presents the main characteristics of rotating cavitation which was found in the inducer test using a water tunnel. The second section describes the rotating cavitation which occurred in the development test of an LE-7 liquid oxygen pump for the H-II rocket. Also described in this section is how the rotating cavitation was suppressed. The rotating cavitation was the cause of both super synchronous shaft vibration and an unstable head coefficient curve. The third section presents how the theory of rotating cavitation was developed. The final section shows the measured cavitation compliance and mass flow gain factor of the LE-7 pump inducer for comparison of the experimental and analytical results of the rotating cavitation of the LE-7 pump inducer. Almost all the information presented in this paper has already been reported by Kamijo et al. (1977, 1980, 1993, 1993) and by Shimura (1993). In the present paper, the authors attempt to combine and give a clear overview of the experimental and analytical results described in the previous papers to systematically show their experience and findings on rotating cavitation.

  12. Rotation Manager Pro Version 1.0b1

    Energy Science and Technology Software Center (OSTI)

    2002-02-01

    The Rotation Manager Pro Package maintains databases of instructions to replicate plate tectonic movements. The instructions are in the standard of tectonic plate rotations, including plate identification and location and angle of the rotation pole. Each database is accompanied by various metadata, including information about each rotation pole and the database itself. The package provides a range of tools to actively manage the database using methods specifically required for rotations: rotation pole addition and subtraction,more » viewing of a rotation chain through the rotation hierarchy, and the rotation of data points.« less

  13. Flow Split Venturi, Axially-Rotated Valve

    DOE Patents [OSTI]

    Walrath, David E.; Lindberg, William R.; Burgess, Robert K.; LaBelle, James

    2000-02-22

    The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. An axially aligned outlet may also increase the flow efficiency. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane. A seal separator may increase the useful life of the seal between the fixed and rotatable portions.

  14. Consider Steam Turbine Drives for Rotating Equipment

    SciTech Connect (OSTI)

    Not Available

    2006-01-01

    This revised ITP tip sheet on steam turbine drives for rotating equipment provides how-to advice for improving the system using low-cost, proven practices and technologies.

  15. FAST FOSSIL ROTATION OF NEUTRON STAR CORES

    SciTech Connect (OSTI)

    Melatos, A.

    2012-12-10

    It is argued that the superfluid core of a neutron star super-rotates relative to the crust, because stratification prevents the core from responding to the electromagnetic braking torque, until the relevant dissipative (viscous or Eddington-Sweet) timescale, which can exceed {approx}10{sup 3} yr and is much longer than the Ekman timescale, has elapsed. Hence, in some young pulsars, the rotation of the core today is a fossil record of its rotation at birth, provided that magnetic crust-core coupling is inhibited, e.g., by buoyancy, field-line topology, or the presence of uncondensed neutral components in the superfluid. Persistent core super-rotation alters our picture of neutron stars in several ways, allowing for magnetic field generation by ongoing dynamo action and enhanced gravitational wave emission from hydrodynamic instabilities.

  16. Physics of Intrinsic Plasma Rotation Explained for First Time

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Physics of Intrinsic Plasma Rotation Explained for First Time Physics of Intrinsic Plasma Rotation Explained for First Time Key understanding for modeling future fusion reactors ...

  17. Forming rotated SAR images by real-time motion compensation....

    Office of Scientific and Technical Information (OSTI)

    collecting Synthetic Aperture Radar (SAR) phase history data on a rotated grid in the Fourier Space of the scene being imaged. Subsequent image formation preserves the rotated...

  18. Water-Efficient Technology Opportunity: Multi-Stream Rotational...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Multi-Stream Rotational Sprinkler Heads Water-Efficient Technology Opportunity: ... rotational sprinkler heads as a water-saving technology that is relevant to the ...

  19. Hidden Rotational Symmetries in Magnetic Domain Patterns

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hidden Rotational Symmetries in Magnetic Domain Patterns Hidden Rotational Symmetries in Magnetic Domain Patterns Print Wednesday, 27 June 2012 00:00 Magnetic thin films have complicated domain patterns that may or may not repeat with each cycle through a hysteresis loop. A magnetic thin film with perpendicular anisotropy, such as that used in computer hard drives, for example, commonly exhibits labyrinthine domain patterns. These patterns are disordered over a macroscopic length scale, and

  20. Split Venturi, Axially-Rotated Valve

    DOE Patents [OSTI]

    Walrath, David E.; Lindberg, William R.; Burgess, Robert K.

    2000-08-29

    The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane.

  1. Position, rotation, and intensity invariant recognizing method

    DOE Patents [OSTI]

    Ochoa, E.; Schils, G.F.; Sweeney, D.W.

    1987-09-15

    A method for recognizing the presence of a particular target in a field of view which is target position, rotation, and intensity invariant includes the preparing of a target-specific invariant filter from a combination of all eigen-modes of a pattern of the particular target. Coherent radiation from the field of view is then imaged into an optical correlator in which the invariant filter is located. The invariant filter is rotated in the frequency plane of the optical correlator in order to produce a constant-amplitude rotational response in a correlation output plane when the particular target is present in the field of view. Any constant response is thus detected in the output plane to determine whether a particular target is present in the field of view. Preferably, a temporal pattern is imaged in the output plane with a optical detector having a plurality of pixels and a correlation coefficient for each pixel is determined by accumulating the intensity and intensity-square of each pixel. The orbiting of the constant response caused by the filter rotation is also preferably eliminated either by the use of two orthogonal mirrors pivoted correspondingly to the rotation of the filter or the attaching of a refracting wedge to the filter to remove the offset angle. Detection is preferably performed of the temporal pattern in the output plane at a plurality of different angles with angular separation sufficient to decorrelate successive frames. 1 fig.

  2. COUNTER-ROTATION IN RELATIVISTIC MAGNETOHYDRODYNAMIC JETS

    SciTech Connect (OSTI)

    Cayatte, V.; Sauty, C.; Vlahakis, N.; Tsinganos, K.; Matsakos, T.; Lima, J. J. G.

    2014-06-10

    Young stellar object observations suggest that some jets rotate in the opposite direction with respect to their disk. In a recent study, Sauty et al. showed that this does not contradict the magnetocentrifugal mechanism that is believed to launch such outflows. Motion signatures that are transverse to the jet axis, in two opposite directions, have recently been measured in M87. One possible interpretation of this motion is that of counter-rotating knots. Here, we extend our previous analytical derivation of counter-rotation to relativistic jets, demonstrating that counter-rotation can indeed take place under rather general conditions. We show that both the magnetic field and a non-negligible enthalpy are necessary at the origin of counter-rotating outflows, and that the effect is associated with a transfer of energy flux from the matter to the electromagnetic field. This can be realized in three cases: if a decreasing enthalpy causes an increase of the Poynting flux, if the flow decelerates, or if strong gradients of the magnetic field are present. An illustration of the involved mechanism is given by an example of a relativistic magnetohydrodynamic jet simulation.

  3. Position, rotation, and intensity invariant recognizing method

    DOE Patents [OSTI]

    Ochoa, Ellen; Schils, George F.; Sweeney, Donald W.

    1989-01-01

    A method for recognizing the presence of a particular target in a field of view which is target position, rotation, and intensity invariant includes the preparing of a target-specific invariant filter from a combination of all eigen-modes of a pattern of the particular target. Coherent radiation from the field of view is then imaged into an optical correlator in which the invariant filter is located. The invariant filter is rotated in the frequency plane of the optical correlator in order to produce a constant-amplitude rotational response in a correlation output plane when the particular target is present in the field of view. Any constant response is thus detected in the output The U.S. Government has rights in this invention pursuant to Contract No. DE-AC04-76DP00789 between the U.S. Department of Energy and AT&T Technologies, Inc.

  4. High-Performance Refrigerator Using Novel Rotating Heat Exchanger |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy High-Performance Refrigerator Using Novel Rotating Heat Exchanger High-Performance Refrigerator Using Novel Rotating Heat Exchanger Rotating heat exchangers installed in appliances and heat pumps have the potentially to reduce energy costs and refrigerant charge in a compact space. Rotating heat exchangers installed in appliances and heat pumps have the potentially to reduce energy costs and refrigerant charge in a compact space. Sandia-developed rotating heat exchanger

  5. Vacuum coupling of rotating superconducting rotor

    DOE Patents [OSTI]

    Shoykhet, Boris A.; Zhang, Burt Xudong; Driscoll, David Infante

    2003-12-02

    A rotating coupling allows a vacuum chamber in the rotor of a superconducting electric motor to be continually pumped out. The coupling consists of at least two concentric portions, one of which is allowed to rotate and the other of which is stationary. The coupling is located on the non-drive end of the rotor and is connected to a coolant supply and a vacuum pump. The coupling is smaller in diameter than the shaft of the rotor so that the shaft can be increased in diameter without having to increase the size of the vacuum seal.

  6. Lateral displacement and rotational displacement sensor

    DOE Patents [OSTI]

    Duden, Thomas

    2014-04-22

    A position measuring sensor formed from opposing sets of capacitor plates measures both rotational displacement and lateral displacement from the changes in capacitances as overlapping areas of capacitors change. Capacitances are measured by a measuring circuit. The measured capacitances are provided to a calculating circuit that performs calculations to obtain angular and lateral displacement from the capacitances measured by the measuring circuit.

  7. Excitation system for rotating synchronous machines

    DOE Patents [OSTI]

    Umans, Stephen D.; Driscoll, David J.

    2002-01-01

    A system for providing DC current to a rotating superconducting winding is provided. The system receives current feedback from the superconducting winding and determines an error signal based on the current feedback and a reference signal. The system determines a control signal corresponding to the error signal and provides a positive and negative superconducting winding excitation voltage based on the control signal.

  8. Wave-particle Interactions In Rotating Mirrors

    SciTech Connect (OSTI)

    Abraham J. Fetterman and Nathaniel J. Fisch

    2011-01-11

    Wave-particle interactions in EB rotating plasmas feature an unusual effect: particles are diffused by waves in both potential energy and kinetic energy. This wave-particle interaction generalizes the alpha channeling effect, in which radio frequency waves are used to remove alpha particles collisionlessly at low energy. In rotating plasmas, the alpha particles may be removed at low energy through the loss cone, and the energy lost may be transferred to the radial electric field. This eliminates the need for electrodes in the mirror throat, which have presented serious technical issues in past rotating plasma devices. A particularly simple way to achieve this effect is to use a high azimuthal mode number perturbation on the magnetic field. Rotation can also be sustained by waves in plasmas without a kinetic energy source. This type of wave has been considered for plasma centrifuges used for isotope separation. Energy may also be transferred from the electric field to particles or waves, which may be useful for ion heating and energy generation.

  9. Compound And Rotational Damping In Warm Nuclei

    SciTech Connect (OSTI)

    Leoni, S.; Bracco, A.; Benzoni, G.; Blasi, N.; Camera, F.; Grassi, C.; Million, B.; Paleni, A.; Pignanelli, M.; Vigezzi, E.; Wieland, O.; Matsuo, M.; Doessing, T.; Herskind, B.; Hagemann, G.B.; Wilson, J.; Maj, A.; Kmiecik, M.; LoBianco, G.; Petrache, C.M.

    2005-04-05

    The {gamma}-decay from excited nuclei is used to study the interplay between rotational motion and compound nucleus formation in deformed nuclei. A new analysis technique is presented which allows for the first time to directly measure the rotational and compound damping widths {gamma}rot and {gamma}{mu} from {gamma}-coincidence spectra. The method is first tested on simulated spectra and then applied to high-statistics EUROBALL data on the nucleus 163Er. Experimental values of {approx_equal}200 and 20 keV are obtained for {gamma}rot and {gamma}{mu}, respectively, in the spin region I {approx_equal} 30-40 ({Dirac_h}/2{pi}), in good agreement with microscopic cranked shell model calculations for the specific nucleus. A dependence of rotational damping on the K-quantum number of the nuclear states is also observed, both in experiment and theory, resulting in a {approx_equal}30% reduction of {gamma}rot for high-K states. This points to a delayed onset of rotational damping in high-K configurations.

  10. Rotatable superconducting cyclotron adapted for medical use

    DOE Patents [OSTI]

    Blosser, Henry G. (East Lansing, MI); Johnson, David A. (Williamston, MI); Riedel, Jack (East Lansing, MI); Burleigh, Richard J. (Berkeley, CA)

    1985-01-01

    A superconducting cyclotron (10) rotatable on a support structure (11) in an arc of about 180.degree. around a pivot axis (A--A) and particularly adapted for medical use is described. The rotatable support structure (13, 15) is balanced by being counterweighted (14) so as to allow rotation of the cyclotron and a beam (12), such as a subparticle (neutron) or atomic particle beam, from the cyclotron in the arc around a patient. Flexible hose (25) is moveably attached to the support structure for providing a liquified gas which is supercooled to near 0.degree. K. to an inlet means (122) to a chamber (105) around superconducting coils (101, 102). The liquid (34) level in the cyclotron is maintained approximately half full so that rotation of the support structure and cyclotron through the 180.degree. can be accomplished without spilling the liquid from the cyclotron. With the coils vertically oriented, each turn of the winding is approximately half immersed in liquid (34) and half exposed to cold gas and adequate cooling to maintain superconducting temperatures in the section of coil above the liquid level is provided by the combination of cold gas/vapor and by the conductive flow of heat along each turn of the winding from the half above the liquid to the half below.

  11. A theoretical analysis of rotating cavitation in inducers

    SciTech Connect (OSTI)

    Tsujimoto, Y.; Kamijo, K. (National Aerospace Lab., Miyagi, (Japan)); Yoshida, Y. (Osaka Univ., Toyonaka, (Japan). Engineering Science)

    1993-03-01

    Rotating cavitation was analyzed using an actuator disk method. Quasi-steady pressure performance of the impeller, mass flow gain factor, and cavitation compliance of the cavity were taken into account. Three types of destabilizing modes were predicted: rotation cavitation propagating faster than the rotational speed of the impeller, rotating cavitation propagating in the direction opposite that of the impeller, and rotating stall propagating slower than the rotational speed of the impeller. It was shown that both types of rotating cavitation were caused by the positive mass flow gain factor, while the rotating stall was caused by the positive slope of the pressure performance. Stability and propagation velocity maps are presented for the two types of rotating cavitation in the mass flow gain factor-cavitation compliance place. The correlation between theoretical results and experimental observations is discussed.

  12. Actuator assembly including a single axis of rotation locking member

    DOE Patents [OSTI]

    Quitmeyer, James N.; Benson, Dwayne M.; Geck, Kellan P.

    2009-12-08

    An actuator assembly including an actuator housing assembly and a single axis of rotation locking member fixedly attached to a portion of the actuator housing assembly and an external mounting structure. The single axis of rotation locking member restricting rotational movement of the actuator housing assembly about at least one axis. The single axis of rotation locking member is coupled at a first end to the actuator housing assembly about a Y axis and at a 90.degree. angle to an X and Z axis providing rotation of the actuator housing assembly about the Y axis. The single axis of rotation locking member is coupled at a second end to a mounting structure, and more particularly a mounting pin, about an X axis and at a 90.degree. angle to a Y and Z axis providing rotation of the actuator housing assembly about the X axis. The actuator assembly is thereby restricted from rotation about the Z axis.

  13. Centrifugally activated bearing for high-speed rotating machinery

    DOE Patents [OSTI]

    Post, Richard F.

    1994-01-01

    A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation.

  14. Centrifugally activated bearing for high-speed rotating machinery

    DOE Patents [OSTI]

    Post, R.F.

    1994-02-15

    A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation. 4 figures.

  15. ARM - Field Campaign - Thin Cloud Rotating Shadowband Radiometer

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Thin Cloud Rotating Shadowband Radiometer 2008.01.08 - 2008.07.18 Lead Scientist : Mary Jane Bartholomew For data sets, see below. Abstract The Thin-Cloud Rotating Shadowband...

  16. Rotational Electrophoresis of Striped Metallic Microrods

    SciTech Connect (OSTI)

    Rose, K A; Meier, J A; Dougherty, G M; Santiago, J G

    2005-11-28

    Analytical models are developed for the translation and rotation of metallic rods in a uniform electric field. The limits of thin and thick electric double layers are considered. These models include the effect of stripes of different metals along the length of the particle. Modeling results are compared to experimental measurements for metallic rods. Experiments demonstrate the increased alignment of particles with increasing field strength and the increase in degree of alignment of thin versus thick electric double layers. The metal rods polarize in the applied field and align parallel to its direction due to torques on the polarized charge. The torque due to polarization has a second order dependence on the electric field strength. The particles are also shown to have an additional alignment torque component due to non-uniform densities along their length. The orientation distributions of dilute suspensions of particles are also shown to agree well with results predicted by a rotational convective-diffusion equation.

  17. MEMS inertial sensors with integral rotation means.

    SciTech Connect (OSTI)

    Kohler, Stewart M.

    2003-09-01

    The state-of-the-art of inertial micro-sensors (gyroscopes and accelerometers) has advanced to the point where they are displacing the more traditional sensors in many size, power, and/or cost-sensitive applications. A factor limiting the range of application of inertial micro-sensors has been their relatively poor bias stability. The incorporation of an integral sensitive axis rotation capability would enable bias mitigation through proven techniques such as indexing, and foster the use of inertial micro-sensors in more accuracy-sensitive applications. Fabricating the integral rotation mechanism in MEMS technology would minimize the penalties associated with incorporation of this capability, and preserve the inherent advantages of inertial micro-sensors.

  18. Chiral meta-atoms rotated by light

    SciTech Connect (OSTI)

    Liu Mingkai; Powell, David A.; Shadrivov, Ilya V.

    2012-07-16

    We study the opto-mechanical properties of coupled chiral meta-atoms based on a pair of twisted split-ring resonators. By using a simple analytical model in conjunction with the Maxwell stress tensor, we capture insight into the mechanism and find that this structure can be used as a general prototype of subwavelength light-driven actuators over a wide range of frequencies. This coupled structure can provide a strong and tunable torque, and can support different opto-mechanical modes, including uniform rotation, periodically variable rotation and damped oscillations. Our results suggest that chiral meta-atoms are good candidates for creating sub-wavelength motors or wrenches controlled by light.

  19. Faraday rotation assisted by linearly polarized light

    SciTech Connect (OSTI)

    Choi, Jai Min; Kim, Jang Myun; Cho, D.

    2007-11-15

    We demonstrate a type of chiral effect of an atomic medium. Polarization rotation of a probe beam is observed only when both a magnetic field and a linearly polarized coupling beam are present. We compare it with other chiral effects like optical activity, the Faraday effect, and the optically induced Faraday effect from the viewpoint of spatial inversion and time reversal transformations. As a theoretical model we consider a five-level configuration involving the cesium D2 transition. We use spin-polarized cold cesium atoms trapped in a magneto-optical trap to measure the polarization rotation versus probe detuning. The result shows reasonable agreement with a calculation from the master equation of the five-level configuration.

  20. Short-Rotation Woody Biomass Sustainability

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Review Short-Rotation Woody Biomass Sustainability Natalie A. Griffiths, Oak Ridge National Laboratory C. Rhett Jackson, University of Georgia Kellie Vache, Oregon State University Jeffrey J. McDonnell, University of Saskatchewan Gregory Starr, University of Alabama John I. Blake, Ben M. Rau, USDA Forest Service This presentation does not contain any proprietary, confidential, or otherwise restricted information March 23, 2015 Analysis and Sustainability *2 Managed by UT-Battelle for the U.S.

  1. Diagnostics - Rotating Wall Machine - UW Plasma Physics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Diagnostics UW Madison Line Tied Reconnection Experiment Diagnostics LTRX HomeResearch MissionLTRX DevicePhysics TopicsDiagnosticsLTRX GalleryLTRX People CPLA Home Directory Publications Links University of Wisconsin Physics Department Department of Energy National Science Foundation As the UW-LTRX was designed with the goal of employing a rotating solid wall along the boundary of the experimental volume, diagnostic access is necessarily much more constrained than in comparable devices. With the

  2. Hidden Rotational Symmetries in Magnetic Domain Patterns

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hidden Rotational Symmetries in Magnetic Domain Patterns Print Magnetic thin films have complicated domain patterns that may or may not repeat with each cycle through a hysteresis loop. A magnetic thin film with perpendicular anisotropy, such as that used in computer hard drives, for example, commonly exhibits labyrinthine domain patterns. These patterns are disordered over a macroscopic length scale, and intuitively we do not expect to observe any symmetry in such systems. Scientists at the

  3. Hidden Rotational Symmetries in Magnetic Domain Patterns

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hidden Rotational Symmetries in Magnetic Domain Patterns Print Magnetic thin films have complicated domain patterns that may or may not repeat with each cycle through a hysteresis loop. A magnetic thin film with perpendicular anisotropy, such as that used in computer hard drives, for example, commonly exhibits labyrinthine domain patterns. These patterns are disordered over a macroscopic length scale, and intuitively we do not expect to observe any symmetry in such systems. Scientists at the

  4. Hidden Rotational Symmetries in Magnetic Domain Patterns

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hidden Rotational Symmetries in Magnetic Domain Patterns Print Magnetic thin films have complicated domain patterns that may or may not repeat with each cycle through a hysteresis loop. A magnetic thin film with perpendicular anisotropy, such as that used in computer hard drives, for example, commonly exhibits labyrinthine domain patterns. These patterns are disordered over a macroscopic length scale, and intuitively we do not expect to observe any symmetry in such systems. Scientists at the

  5. Rotating copper plasmoid in external magnetic field

    SciTech Connect (OSTI)

    Pandey, Pramod K.; Thareja, Raj K.

    2013-02-15

    Effect of nonuniform magnetic field on the expanding copper plasmoid in helium and argon gases using optical emission spectroscopy and fast imaging is presented. We report a peculiar oscillatory rotation of plasmoid in magnetic field and argon ambient. The temporal variation and appearance of the dip in the electron temperature show a direct evidence of the threading and expulsion of the magnetic field lines from the plasmoid. Rayleigh Taylor instability produced at the interface separating magnetic field and plasma is discussed.

  6. Edge rotational magnons in magnonic crystals

    SciTech Connect (OSTI)

    Lisenkov, Ivan Kalyabin, Dmitry; Moscow Institute of Physics and Technology, 9 Instituskij per., Dolgoprudny, 141700 Moscow Region ; Nikitov, Sergey; Moscow Institute of Physics and Technology, 9 Instituskij per., Dolgoprudny, 141700 Moscow Region; Saratov State University, 112 Bol'shaya Kazach'ya, Saratov 410012

    2013-11-11

    It is predicted that in 2D magnonic crystals the edge rotational magnons of forward volume magnetostatic spin waves can exist. Under certain conditions, locally bounded magnons may appear within the crystal consisting of the ferromagnetic matrix and periodically inserted magnetic/non-magnetic inclusions. It is also shown that interplay of different resonances in 2D magnonic crystal may provide conditions for spin wave modes existence with negative group velocity.

  7. Hidden Rotational Symmetries in Magnetic Domain Patterns

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hidden Rotational Symmetries in Magnetic Domain Patterns Print Magnetic thin films have complicated domain patterns that may or may not repeat with each cycle through a hysteresis loop. A magnetic thin film with perpendicular anisotropy, such as that used in computer hard drives, for example, commonly exhibits labyrinthine domain patterns. These patterns are disordered over a macroscopic length scale, and intuitively we do not expect to observe any symmetry in such systems. Scientists at the

  8. Hidden Rotational Symmetries in Magnetic Domain Patterns

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hidden Rotational Symmetries in Magnetic Domain Patterns Print Magnetic thin films have complicated domain patterns that may or may not repeat with each cycle through a hysteresis loop. A magnetic thin film with perpendicular anisotropy, such as that used in computer hard drives, for example, commonly exhibits labyrinthine domain patterns. These patterns are disordered over a macroscopic length scale, and intuitively we do not expect to observe any symmetry in such systems. Scientists at the

  9. Hidden Rotational Symmetries in Magnetic Domain Patterns

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hidden Rotational Symmetries in Magnetic Domain Patterns Print Magnetic thin films have complicated domain patterns that may or may not repeat with each cycle through a hysteresis loop. A magnetic thin film with perpendicular anisotropy, such as that used in computer hard drives, for example, commonly exhibits labyrinthine domain patterns. These patterns are disordered over a macroscopic length scale, and intuitively we do not expect to observe any symmetry in such systems. Scientists at the

  10. Hidden Rotational Symmetries in Magnetic Domain Patterns

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hidden Rotational Symmetries in Magnetic Domain Patterns Print Magnetic thin films have complicated domain patterns that may or may not repeat with each cycle through a hysteresis loop. A magnetic thin film with perpendicular anisotropy, such as that used in computer hard drives, for example, commonly exhibits labyrinthine domain patterns. These patterns are disordered over a macroscopic length scale, and intuitively we do not expect to observe any symmetry in such systems. Scientists at the

  11. Hidden Rotational Symmetries in Magnetic Domain Patterns

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hidden Rotational Symmetries in Magnetic Domain Patterns Print Magnetic thin films have complicated domain patterns that may or may not repeat with each cycle through a hysteresis loop. A magnetic thin film with perpendicular anisotropy, such as that used in computer hard drives, for example, commonly exhibits labyrinthine domain patterns. These patterns are disordered over a macroscopic length scale, and intuitively we do not expect to observe any symmetry in such systems. Scientists at the

  12. Face seal assembly for rotating drum

    DOE Patents [OSTI]

    Morgan, J. Giles; Rennich, Mark J.; Whatley, Marvin E.

    1982-01-01

    A seal assembly comprises a tube rotatable about its longitudinal axis and having two longitudinally spaced flanges projecting radially outwardly from the outer surface thereof. Slidably positioned against one of the flanges is a seal ring, and disposed between this seal ring and the other flange are two rings that are forced apart by springs, one of the latter rings being attached to a flexible wall.

  13. Consider Steam Turbine Drives for Rotating Equipment | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Steam Turbine Drives for Rotating Equipment Consider Steam Turbine Drives for Rotating Equipment This tip sheet outlines the benefits of steam turbine drives for rotating equipment as part of optimized steam systems. STEAM TIP SHEET #21 Consider Steam Turbine Drives for Rotating Equipment (January 2012) (398.66 KB) More Documents & Publications Improving Steam System Performance: A Sourcebook for Industry, Second Edition Adjustable Speed Drive Part-Load Efficiency Benchmark the Fuel Cost of

  14. Video: Collective cell motion - rotation | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Video: Collective cell motion - rotation Share Topic Environment Biology Computational biology Programs Materials science Materials simulation & theory Mathematics, computing, & ...

  15. Microscopic origin of quantum chaos in rotational damping

    SciTech Connect (OSTI)

    Matsuo, M.; Dossing, T.; Vigezzi, E.; Broglia, R.A. (Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto (Japan) The Niels Bohr Institute, University of Copenhagen (Denmark) Instituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano (Italy) Departimento di Fisica dell'Universita di Milano, Milano (Italy))

    1993-05-03

    The rotational spectrum of [sup 168]Yb is calclated by diagonalizing different effective interactions within the basis of unperturbed rotational bands provided by the cranked shell model. A transition between order and chaos taking place in the energy region between 1 and 2 MeV above the yrast line is observed, associated with the onset of rotational damping. It can be related to the higher multipole components of the force acting among the unperturbed rotational bands.

  16. 3 MW Solid Rotating Target Design

    SciTech Connect (OSTI)

    McManamy, Thomas J; Gallmeier, Franz X; Rennich, Mark J; Ferguson, Phillip D; Janney, Jim G

    2010-01-01

    A rotating solid target design concept is being developed for potential use at the second SNS target station (STS). A long pulse beam (~ 1 msec) at 1.3 GeV and 20 Hz is planned with power levels at or above 1 MW. Since the long pulse may give future opportunities for higher power, this study is looking at 3 MW to compare the performance of a solid rotating target to a mercury target. Unlike the case for stationary solid targets at such powers this study indicates that a rotating solid target, when used with large coupled hydrogen moderators, has neutronic performance equal to or better than that with a mercury target, and the solid target has a greatly increased lifetime. Design studies have investigated water cooled tungsten targets with tantalum cladding approximately 1.2 m in diameter, and 70mm thick. Operating temperatures are low ( < 150 C) with mid-plane, top and bottom surface cooling. In case of cooling system failure, the diameter gives enough surface area to remove the decay heat by radiation to the surrounding reflector assemblies while keeping the peak temperatures below approximately 700 C. This temperature should mitigate potential loss of coolant accidents and subsequent steam, tungsten interaction which has a threshold of approximately 800 C. Design layouts for the sealing systems and potential target station concepts have been developed.

  17. Measurement of turbulent wind velocities using a rotating boom apparatus

    SciTech Connect (OSTI)

    Sandborn, V.A.; Connell, J.R.

    1984-04-01

    The present report covers both the development of a rotating-boom facility and the evaluation of the spectral energy of the turbulence measured relative to the rotating boom. The rotating boom is composed of a helicopter blade driven through a pulley speed reducer by a variable speed motor. The boom is mounted on a semiportable tower that can be raised to provide various ratios of hub height to rotor diameter. The boom can be mounted to rotate in either the vertical or horizontal plane. Probes that measure the three components of turbulence can be mounted at any location along the radius of the boom. Special hot-film sensors measured two components of the turbulence at a point directly in front of the rotating blade. By using the probe rotated 90/sup 0/ about its axis, the third turbulent velocity component was measured. Evaluation of the spectral energy distributions for the three components of velocity indicates a large concentration of energy at the rotational frequency. At frequencies slightly below the rotational frequency, the spectral energy is greatly reduced over that measured for the nonrotating case measurements. Peaks in the energy at frequencies that are multiples of the rotation frequency were also observed. We conclude that the rotating boom apparatus is suitable and ready to be used in experiments for developing and testing sensors for rotational measurement of wind velocity from wind turbine rotors. It also can be used to accurately measure turbulent wind for testing theories of rotationally sampled wind velocity.

  18. Controlling Data Collection to Support SAR Image Rotation

    DOE Patents [OSTI]

    Doerry, Armin W.; Cordaro, J. Thomas; Burns, Bryan L.

    2008-10-14

    A desired rotation of a synthetic aperture radar (SAR) image can be facilitated by adjusting a SAR data collection operation based on the desired rotation. The SAR data collected by the adjusted SAR data collection operation can be efficiently exploited to form therefrom a SAR image having the desired rotational orientation.

  19. Spin-stabilized magnetic levitation without vertical axis of rotation

    DOE Patents [OSTI]

    Romero, Louis; Christenson, Todd; Aaronson, Gene

    2009-06-09

    The symmetry properties of a magnetic levitation arrangement are exploited to produce spin-stabilized magnetic levitation without aligning the rotational axis of the rotor with the direction of the force of gravity. The rotation of the rotor stabilizes perturbations directed parallel to the rotational axis.

  20. Tracking single-particle rotation during macrophage uptake

    SciTech Connect (OSTI)

    Sanchez, Lucero; Patton, Paul; Anthony, Stephen Michael; Yi, Yi; Yu, Yan

    2015-06-10

    We investigated the rotational dynamics of single microparticles during their internalization by macrophage cells. The microparticles used were triblock patchy particles that display two fluorescent patches on their two poles. The optical anisotropy made it possible to directly visualize and quantify the orientation and rotation of the particles. We show that particles exhibit a mixture of fast and slow rotation as they are uptaken by macrophages and transiently undergo directional rotation during their entry into the cell. As a result, the size of the particles and the surface presentation of ligands exerted a negligible influence on this heterogeneity of particle rotation.

  1. Tracking single-particle rotation during macrophage uptake

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sanchez, Lucero; Patton, Paul; Anthony, Stephen Michael; Yi, Yi; Yu, Yan

    2015-06-10

    We investigated the rotational dynamics of single microparticles during their internalization by macrophage cells. The microparticles used were triblock patchy particles that display two fluorescent patches on their two poles. The optical anisotropy made it possible to directly visualize and quantify the orientation and rotation of the particles. We show that particles exhibit a mixture of fast and slow rotation as they are uptaken by macrophages and transiently undergo directional rotation during their entry into the cell. As a result, the size of the particles and the surface presentation of ligands exerted a negligible influence on this heterogeneity of particlemore » rotation.« less

  2. A method for determining poloidal rotation from poloidal asymmetry in toroidal rotation (invited)

    SciTech Connect (OSTI)

    Chrystal, C.; Burrell, K. H.; Lao, L. L.; Pace, D. C.; Grierson, B. A.

    2014-11-15

    A new diagnostic has been developed on DIII-D that determines the impurity poloidal rotation from the poloidal asymmetry in the toroidal angular rotation velocity. This asymmetry is measured with recently added tangential charge exchange viewchords on the high-field side of the tokamak midplane. Measurements are made on co- and counter-current neutral beams, allowing the charge exchange cross section effect to be measured and eliminating the need for atomic physics calculations. The diagnostic implementation on DIII-D restricts the measurement range to the core (r/a < 0.6) where, relative to measurements made with the vertical charge exchange system, the spatial resolution is improved. Significant physics results have been obtained with this new diagnostic; for example, poloidal rotation measurements that significantly exceed neoclassical predictions.

  3. TIDALLY DRIVEN DYNAMOS IN A ROTATING SPHERE

    SciTech Connect (OSTI)

    Cébron, D.; Hollerbach, R. E-mail: r.hollerbach@leeds.ac.uk

    2014-07-01

    Large-scale planetary or stellar magnetic fields generated by a dynamo effect are mostly attributed to flows forced by buoyancy forces in electrically conducting fluid layers. However, these large-scale fields may also be controlled by tides, as previously suggested for the star τ-boo, Mars, or the early Moon. By simulating a small local patch of a rotating fluid, Barker and Lithwick have recently shown that tides can drive small-scale dynamos by exciting a hydrodynamic instability, the so-called elliptical (or tidal) instability. By performing global magnetohydrodynamic simulations of a rotating spherical fluid body, we investigate if this instability can also drive the observed large-scale magnetic fields. We are thus interested in the dynamo threshold and the generated magnetic field in order to test if such a mechanism is relevant for planets and stars. Rather than solving the problem in a geometry deformed by tides, we consider a spherical fluid body and add a body force to mimic the tidal deformation in the bulk of the fluid. This allows us to use an efficient spectral code to solve the magnetohydrodynamic problem. We first compare the hydrodynamic results with theoretical asymptotic results and numerical results obtained in a truly deformed ellipsoid, which confirms the presence of elliptical instability. We then perform magnetohydrodynamic simulations and investigate the dynamo capability of the flow. Kinematic and self-consistent dynamos are finally simulated, showing that the elliptical instability is capable of generating a dipole-dominated large-scale magnetic field in global simulations of a fluid rotating sphere.

  4. Manipulator for rotating and examining small spheres

    DOE Patents [OSTI]

    Weinstein, B.W.; Willenborg, D.L.

    1980-02-12

    A manipulator is disclosed which provides fast, accurate rotational positioning of a small sphere, such as an inertial confinement fusion target, which allows inspecting of the entire surface of the sphere. The sphere is held between two flat, flexible tips which move equal amounts in opposite directions. This provides rolling of the ball about two orthogonal axes without any overall translation. The manipulator may be controlled, for example, by an x- and y-axis driven controlled by a mini-computer which can be programmed to generate any desired scan pattern. 8 figs.

  5. Magnetospheric structure of rotation powered pulsars

    SciTech Connect (OSTI)

    Arons, J. California Univ., Livermore, CA . Inst. of Geophysics and Planetary Physics)

    1991-01-07

    I survey recent theoretical work on the structure of the magnetospheres of rotation powered pulsars, within the observational constraints set by their observed spindown, their ability to power synchrotron nebulae and their ability to produce beamed collective radio emission, while putting only a small fraction of their energy into incoherent X- and gamma radiation. I find no single theory has yet given a consistent description of the magnetosphere, but I conclude that models based on a dense outflow of pairs from the polar caps, permeated by a lower density flow of heavy ions, are the most promising avenue for future research. 106 refs., 4 figs., 2 tabs.

  6. Rotating electric machine with fluid supported parts

    DOE Patents [OSTI]

    Smith, Jr., Joseph L.; Kirtley, Jr., James L.

    1981-01-01

    A rotating electric machine in which the armature winding thereof and other parts are supported by a liquid to withstand the mechanical stresses applied during transient overloads and the like. In particular, a narrow gap is provided between the armature winding and the stator which supports it and this gap is filled with an externally pressurized viscous liquid. The liquid is externally pressurized sufficiently to balance the static loads on the armature winding. Transient mechanical loads which deform the armature winding alter the gap dimensions and thereby additionally pressurize the viscous liquid to oppose the armature winding deformation and more nearly uniformly to distribute the resulting mechanical stresses.

  7. Manipulator for rotating and examining small spheres

    DOE Patents [OSTI]

    Weinstein, Berthold W. [Livermore, CA; Willenborg, David L. [Livermore, CA

    1980-02-12

    A manipulator which provides fast, accurate rotational positioning of a small sphere, such as an inertial confinement fusion target, which allows inspecting of the entire surface of the sphere. The sphere is held between two flat, flexible tips which move equal amounts in opposite directions. This provides rolling of the ball about two orthogonal axes without any overall translation. The manipulator may be controlled, for example, by an x- and y-axis driven controlled by a mini-computer which can be programmed to generate any desired scan pattern.

  8. Dynamics and Statistical Mechanics of Rotating and non-Rotating Vortical Flows

    SciTech Connect (OSTI)

    Lim, Chjan

    2013-12-18

    Three projects were analyzed with the overall aim of developing a computational/analytical model for estimating values of the energy, angular momentum, enstrophy and total variation of fluid height at phase transitions between disordered and self-organized flow states in planetary atmospheres. It is believed that these transitions in equilibrium statistical mechanics models play a role in the construction of large-scale, stable structures including super-rotation in the Venusian atmosphere and the formation of the Great Red Spot on Jupiter. Exact solutions of the spherical energy-enstrophy models for rotating planetary atmospheres by Kac's method of steepest descent predicted phase transitions to super-rotating solid-body flows at high energy to enstrophy ratio for all planetary spins and to sub-rotating modes if the planetary spin is large enough. These canonical statistical ensembles are well-defined for the long-range energy interactions that arise from 2D fluid flows on compact oriented manifolds such as the surface of the sphere and torus. This is because in Fourier space available through Hodge theory, the energy terms are exactly diagonalizable and hence has zero range, leading to well-defined heat baths.

  9. How good a clock is rotation? The stellar rotation-mass-age relationship for old field stars

    SciTech Connect (OSTI)

    Epstein, Courtney R.; Pinsonneault, Marc H. E-mail: pinsono@astronomy.ohio-state.edu

    2014-01-10

    The rotation-mass-age relationship offers a promising avenue for measuring the ages of field stars, assuming the attendant uncertainties to this technique can be well characterized. We model stellar angular momentum evolution starting with a rotation distribution from open cluster M37. Our predicted rotation-mass-age relationship shows significant zero-point offsets compared to an alternative angular momentum loss law and published gyrochronology relations. Systematic errors at the 30% level are permitted by current data, highlighting the need for empirical guidance. We identify two fundamental sources of uncertainty that limit the precision of rotation-based ages and quantify their impact. Stars are born with a range of rotation rates, which leads to an age range at fixed rotation period. We find that the inherent ambiguity from the initial conditions is important for all young stars, and remains large for old stars below 0.6 M {sub ☉}. Latitudinal surface differential rotation also introduces a minimum uncertainty into rotation period measurements and, by extension, rotation-based ages. Both models and the data from binary star systems 61 Cyg and α Cen demonstrate that latitudinal differential rotation is the limiting factor for rotation-based age precision among old field stars, inducing uncertainties at the ∼2 Gyr level. We also examine the relationship between variability amplitude, rotation period, and age. Existing ground-based surveys can detect field populations with ages as old as 1-2 Gyr, while space missions can detect stars as old as the Galactic disk. In comparison with other techniques for measuring the ages of lower main sequence stars, including geometric parallax and asteroseismology, rotation-based ages have the potential to be the most precise chronometer for 0.6-1.0 M {sub ☉} stars.

  10. Counter-Rotating Tandem Motor Drilling System

    SciTech Connect (OSTI)

    Kent Perry

    2009-04-30

    Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger than

  11. Rotational actuator of motor based on carbon nanotubes

    DOE Patents [OSTI]

    Zettl, Alexander K.; Fennimore, Adam M.; Yuzvinsky, Thomas D.

    2008-11-18

    A rotational actuator/motor based on rotation of a carbon nanotube is disclosed. The carbon nanotube is provided with a rotor plate attached to an outer wall, which moves relative to an inner wall of the nanotube. After deposit of a nanotube on a silicon chip substrate, the entire structure may be fabricated by lithography using selected techniques adapted from silicon manufacturing technology. The structures to be fabricated may comprise a multiwall carbon nanotube (MWNT), two in plane stators S1, S2 and a gate stator S3 buried beneath the substrate surface. The MWNT is suspended between two anchor pads and comprises a rotator attached to an outer wall and arranged to move in response to electromagnetic inputs. The substrate is etched away to allow the rotor to freely rotate. Rotation may be either in a reciprocal or fully rotatable manner.

  12. Rotational actuator or motor based on carbon nanotubes

    DOE Patents [OSTI]

    Zetti, Alexander K.; Fennimore, Adam M.; Yuzvinsky, Thomas D.

    2006-05-30

    A rotational actuator/motor based on rotation of a carbon nanotube is disclosed. The carbon nanotube is provided with a rotor plate attached to an outer wall, which moves relative to an inner wall of the nanotube. After deposit of a nanotube on a silicon chip substrate, the entire structure may be fabricated by lithography using selected techniques adapted from silicon manufacturing technology. The structures to be fabricated may comprise a multiwall carbon nanotube (MWNT), two in plane stators S1, S2 and a gate stator S3 buried beneath the substrate surface. The MWNT is suspended between two anchor pads and comprises a rotator attached to an outer wall and arranged to move in response to electromagnetic inputs. The substrate is etched away to allow the rotor to freely rotate. Rotation may be either in a reciprocal or fully rotatable manner.

  13. Testing Oxygen Reduction Reaction Activity with the Rotating Disc Electrode

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Technique | Department of Energy Oxygen Reduction Reaction Activity with the Rotating Disc Electrode Technique Testing Oxygen Reduction Reaction Activity with the Rotating Disc Electrode Technique Presentation slides from the Fuel Cell Technologies Office webinar, "Testing Oxygen Reduction Reaction Activity with the Rotating Disc Electrode Technique," held March 12, 2013. Presenters were Shyam S. Kocha, National Renewable Energy Laboratory; Yannick Garsany, Naval Research

  14. Physics of Intrinsic Plasma Rotation Explained for First Time

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Physics of Intrinsic Plasma Rotation Explained for First Time Physics of Intrinsic Plasma Rotation Explained for First Time Key understanding for modeling future fusion reactors such as ITER July 23, 2013 CHANG.JPG Flamelets or hot spots along the plasma edge (a) drive turbulence intensity (b), temperature intensity (c), and intrinsic torque (d) inward, converting heat into toroidal rotation. (S. Ku et al.) If humans could harness nuclear fusion, the process that powers stars like our sun, the

  15. Alpha Channeling in Rotating Plasma with Stationary Waves

    SciTech Connect (OSTI)

    A. Fetterman and N.J. Fisch

    2010-02-15

    An extension of the alpha channeling effect to supersonically rotating mirrors shows that the rotation itself can be driven using alpha particle energy. Alpha channeling uses radiofrequency waves to remove alpha particles collisionlessly at low energy. We show that stationary magnetic fields with high n? can be used for this purpose, and simulations show that a large fraction of the alpha energy can be converted to rotation energy.

  16. Forming rotated SAR images by real-time motion compensation.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2012-12-01

    Proper waveform parameter selection allows collecting Synthetic Aperture Radar (SAR) phase history data on a rotated grid in the Fourier Space of the scene being imaged. Subsequent image formation preserves the rotated geometry to allow SAR images to be formed at arbitrary rotation angles without the use of computationally expensive interpolation or resampling operations. This should be useful where control of image orientation is desired such as generating squinted stripmaps and VideoSAR applications, among others.

  17. Joint Downscale Fluxes of Energy and Potential Enstrophy in Rotating

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Stratified Boussinesq Flows | Argonne Leadership Computing Facility Joint Downscale Fluxes of Energy and Potential Enstrophy in Rotating Stratified Boussinesq Flows Authors: Kurien, S., Aluie, H. We use high-resolution simulations of Boussinesq flows, forced in the large-scales, with fixed rotation and stable stratification along the vertical axis, to study the cascades of energy and potential enstrophy to small-scales in three different regimes of stratification and rotation. For strongly

  18. Hybrid fs/ps Rotational CARS Temperature and Concentration Measurement...

    Office of Scientific and Technical Information (OSTI)

    Hybrid fsps Rotational CARS Temperature and Concentration Measurements Using Two Different ps-Duration Probe Beams. Citation Details In-Document Search Title: Hybrid fsps ...

  19. Controlling octahedral rotations in a perovskite via strain doping...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Controlling octahedral rotations in a perovskite via strain doping Citation Details In-Document Search ... Type: Accepted Manuscript Journal Name: Scientific Reports ...

  20. Testing Oxygen Reduction Reaction Activity with the Rotating...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Rotating Disk-Electrode Aqueous Electrolyte Accelerated Stress Tests for PGM ElectrocatalystSupport Durability Evaluation Performance Measurement of MEAs Catalysis Working Group ...

  1. Interactions between Grain Rotation and Local Deformation. (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Interactions between Grain Rotation and Local Deformation. Abstract not provided. Authors: Carroll, Jay ; Lim, Hojun ; Boyce, Brad Lee ; Battaile, Corbett Chandler. ; ...

  2. Evaluating Deformation-Induced Rotation in a Polycrystal During...

    Office of Scientific and Technical Information (OSTI)

    Title: Evaluating Deformation-Induced Rotation in a Polycrystal During In Situ Tensile Deformation using EBSD. Abstract not provided. Authors: Carroll, Jay ; Clark, Blythe ; Boyce, ...

  3. Cooling for a rotating anode X-ray tube

    DOE Patents [OSTI]

    Smither, Robert K. (Hinsdale, IL)

    1998-01-01

    A method and apparatus for cooling a rotating anode X-ray tube. An electromagnetic motor is provided to rotate an X-ray anode with cooling passages in the anode. These cooling passages are coupled to a cooling structure located adjacent the electromagnetic motor. A liquid metal fills the passages of the cooling structure and electrical power is provided to the motor to rotate the anode and generate a rotating magnetic field which moves the liquid metal through the cooling passages and cooling structure.

  4. Abstract: Development and Deployment of a Short Rotation Woody...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Crops Harvesting System Based on a Case New Holland Forage Harvester and SRC Woody Crop Header Abstract: Development and Deployment of a Short Rotation Woody Crops Harvesting ...

  5. ARM: Portable Radiation Package: Fast Rotating Shadowband Radiometer...

    Office of Scientific and Technical Information (OSTI)

    Portable Radiation Package: Fast Rotating Shadowband Radiometer full resolution 6-s sampling Authors: Annette Koontz ; R. Reynolds Publication Date: 2012-11-02 OSTI Identifier: ...

  6. NREL: MIDC/Oak Ridge National Laboratory Rotating Shadowband Radiometer

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (35.93 N, 84.31 W, 245 m, GMT-5) Oak Ridge National Laboratory Irradiance Inc. Rotating Shadowband

  7. A rotating target wheel system for Gammasphere (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    System). A brief history of these rotating target ... 10.10631.59072; (c) 1999 American Institute of Physics; ... Country of Publication: United States Language: English ...

  8. Consider Steam Turbine Drives for Rotating Equipment, Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1 Consider Steam Turbine Drives for Rotating Equipment Steam turbines are well suited as ... This service generally calls for a backpressure noncondensing steam turbine. The ...

  9. Strategies for Single-Laser-Shot Femtosecond Pure-Rotational...

    Office of Scientific and Technical Information (OSTI)

    Title: Strategies for Single-Laser-Shot Femtosecond Pure-Rotational CARS Thermometry. Authors: Kearney, Sean P. ; Farrow, Darcie ; Miller, Joseph ; Meyer, Terrence R. Publication ...

  10. Change of translational-rotational coupling in liquids revealed...

    Office of Scientific and Technical Information (OSTI)

    of the spectral separation of the translational and the rotational relaxation contribution. In contrast to o-terphenyl, glycerol and PG show a spectral separation much larger than ...

  11. Relativistic theory of nuclear spin-rotation tensor with kinetically balanced rotational London orbitals

    SciTech Connect (OSTI)

    Xiao, Yunlong; Zhang, Yong; Liu, Wenjian

    2014-10-28

    Both kinetically balanced (KB) and kinetically unbalanced (KU) rotational London orbitals (RLO) are proposed to resolve the slow basis set convergence in relativistic calculations of nuclear spin-rotation (NSR) coupling tensors of molecules containing heavy elements [Y. Xiao and W. Liu, J. Chem. Phys. 138, 134104 (2013)]. While they perform rather similarly, the KB-RLO Ansatz is clearly preferred as it ensures the correct nonrelativistic limit even with a finite basis. Moreover, it gives rise to the same “direct relativistic mapping” between nuclear magnetic resonance shielding and NSR coupling tensors as that without using the London orbitals [Y. Xiao, Y. Zhang, and W. Liu, J. Chem. Theory Comput. 10, 600 (2014)].

  12. Magnetic and antimagnetic rotation in covariant density functional theory

    SciTech Connect (OSTI)

    Zhao, P. W.; Liang, H. Z.; Peng, J.; Ring, P.; Zhang, S. Q.; Meng, J.

    2012-10-20

    Progress on microscopic and self-consistent description of the magnetic rotation and antimagnetic rotation phenomena in tilted axis cranking relativistic mean-field theory based on a point-coupling interaction are briefly reviewed. In particular, the microscopic pictures of the shears mechanism in {sup 60}Ni and the two shears-like mechanism in {sup 105}Cd are discussed.

  13. Test report for slow rotation core sampling test

    SciTech Connect (OSTI)

    Ralston, G.L.

    1995-04-03

    This report documents the temperature increase experienced when core sampling equipment is rotated slowly with a relatively low downforce applied to the drill string (nominal 10 rpm/400 lb downforce). The test was carried out in close to worst-case conditions, rotating against a cement mixture in one test sequence, and a steel plate in the second test sequence.

  14. Galvano-rotational effect induced by electroweak interactions in pulsars

    SciTech Connect (OSTI)

    Dvornikov, Maxim

    2015-05-21

    We study electroweakly interacting particles in rotating matter. The existence of the electric current along the axis of the matter rotation is predicted in this system. This new galvano-rotational effect is caused by the parity violating interaction between massless charged particles in the rotating matter. We start with the exact solution of the Dirac equation for a fermion involved in the electroweak interaction in the rotating frame. This equation includes the noninertial effects. Then, using the obtained solution, we derive the induced electric current which turns out to flow along the rotation axis. We study the possibility of the appearance of the galvano-rotational effect in dense matter of compact astrophysical objects. The particular example of neutron and hypothetical quark stars is discussed. It is shown that, using this effect, one can expect the generation of toroidal magnetic fields comparable with poloidal ones in old millisecond pulsars. We also briefly discuss the generation of the magnetic helicity in these stars. Finally we analyze the possibility to apply the galvano-rotational effect for the description of the asymmetric neutrino emission from a neutron star to explain pulsars kicks.

  15. Rotational dynamics of cargos at pauses during axonal transport

    SciTech Connect (OSTI)

    Gu, Yan; Sun, Wei; Wang, Gufeng; Jeftinija, Ksenija; Jeftinija, Srdija; Fang, Ning

    2012-08-28

    Direct visualization of axonal transport in live neurons is essential for our understanding of the neuronal functions and the working mechanisms of microtubule-based motor proteins. Here we use the high-speed single particle orientation and rotational tracking technique to directly visualize the rotational dynamics of cargos in both active directional transport and pausing stages of axonal transport, with a temporal resolution of 2 ms. Both long and short pauses are imaged, and the correlations between the pause duration, the rotational behaviour of the cargo at the pause, and the moving direction after the pause are established. Furthermore, the rotational dynamics leading to switching tracks are visualized in detail. These first-time observations of cargo's rotational dynamics provide new insights on how kinesin and dynein motors take the cargo through the alternating stages of active directional transport and pause.

  16. Ultrafast terahertz Faraday rotation in graphene

    SciTech Connect (OSTI)

    Heyman, J. N.; Foo Kune, R. F.; Alebachew, B. A.; Nguyen, M. D.; Robinson, J. T.

    2014-12-07

    Terahertz (THz) Faraday rotation measurements were performed to investigate carrier dynamics in p-type Chemical vapor deposition (CVD) graphene. We used static and time-resolved polarization-sensitive THz transmission measurements in a magnetic field to probe free carriers in GaAs, InP, and Graphene. Static measurements probe the equilibrium carrier density and momentum scattering rate. Time-resolved (optical pump/THz probe) measurements probe the change in these quantities following photoexcitation. In a typical CVD graphene sample, we found that 0.5 ps following photoexcitation with 1 × 10{sup 13} photons/cm{sup 2} pulses at 800 nm the effective hole scattering time decreased from 37 fs to 34.5 fs, while the carrier concentration increased from 2.0 × 10{sup 12} cm{sup −2} to 2.04 × 10{sup 12} cm{sup −2}, leading to a transient decrease in the conductivity of the film.

  17. Solid State Replacement of Rotating Mirror Cameras

    SciTech Connect (OSTI)

    Frank, A M; Bartolick, J M

    2006-08-25

    Rotating mirror cameras have been the mainstay of mega-frame per second imaging for decades. There is still no electronic camera that can match a film based rotary mirror camera for the combination of frame count, speed, resolution and dynamic range. The rotary mirror cameras are predominantly used in the range of 0.1 to 100 micro-seconds per frame, for 25 to more than a hundred frames. Electron tube gated cameras dominate the sub microsecond regime but are frame count limited. Video cameras are pushing into the microsecond regime but are resolution limited by the high data rates. An all solid state architecture, dubbed ''In-situ Storage Image Sensor'' or ''ISIS'', by Prof. Goji Etoh, has made its first appearance into the market and its evaluation is discussed. Recent work at Lawrence Livermore National Laboratory has concentrated both on evaluation of the presently available technologies and exploring the capabilities of the ISIS architecture. It is clear though there is presently no single chip camera that can simultaneously match the rotary mirror cameras, the ISIS architecture has the potential to approach their performance.

  18. Theoretical rotation-vibration spectrum of thioformaldehyde

    SciTech Connect (OSTI)

    Yachmenev, Andrey; Polyak, Iakov; Thiel, Walter

    2013-11-28

    We present a variational calculation of the first comprehensive T = 300 K rovibrational line list for thioformaldehyde, H{sub 2}CS. It covers 41?809 rovibrational levels for states up to J{sub max} = 30 with vibrational band origins up to 5000 cm{sup ?1} and provides the energies and line intensities for 547?926 transitions from the ground vibrational state to these levels. It is based on our previously reported accurate ab initio potential energy surface and a newly calculated ab initio dipole moment surface. Minor empirical adjustments are made to the ab initio equilibrium geometry to reduce systematic errors in the predicted intra-band rotational energy levels. The rovibrational energy levels and transition intensities are computed variationally by using the methods implemented in the computer program TROVE. Transition wavelengths and intensities are found to be in excellent agreement with the available experimental data. The present calculations correctly reproduce the observed resonance effects, such as intensity borrowing, thus reflecting the high accuracy of the underlying ab initio surfaces. We report a detailed analysis of several vibrational bands, especially those complicated by strong Coriolis coupling, to facilitate future laboratory assignments.

  19. Omni-directional and holonomic rolling platform with decoupled rotational and translational degrees of freedom

    DOE Patents [OSTI]

    Pin, F.G.; Killough, S.M.

    1994-12-20

    A wheel assembly includes a support, a cage rotatably mounted on the support and having a longitudinal rotation axis, a first ball wheel rotatably mounted in the cage and having a rotation axis orthogonal to the rotation axis of the cage, and a second ball wheel rotatably mounted in the cage and having a rotation axis orthogonal to the rotation axis or the cage and to the rotation axis of the first ball wheel. A control circuit includes a photodetector signal which indicates ground contact for each ball wheel, and a tachometer which indicates actual drive shaft velocity. 6 figures.

  20. Omni-directional and holonomic rolling platform with decoupled rotational and translational degrees of freedom

    DOE Patents [OSTI]

    Pin, Francois G.; Killough, Stephen M.

    1994-01-01

    A wheel assembly includes a support, a cage rotatably mounted on the support and having a longitudinal rotation axis, a first ball wheel rotatably mounted in the cage and having a rotation axis orthogonal to the rotation axis of the cage, and a second ball wheel rotatably mounted in the cage and having a rotation axis orthogonal to the rotation axis or the cage and to the rotation axis of the first ball wheel. A control circuit includes a photodetector signal which indicates ground contact for each ball wheel, and a tachometer which indicates actual drive shaft velocity.

  1. Tracking single particle rotation: Probing dynamics in four dimensions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Anthony, Stephen Michael; Yu, Yan

    2015-04-29

    Direct visualization and tracking of small particles at high spatial and temporal resolution provides a powerful approach to probing complex dynamics and interactions in chemical and biological processes. Analysis of the rotational dynamics of particles adds a new dimension of information that is otherwise impossible to obtain with conventional 3-D particle tracking. In this review, we survey recent advances in single-particle rotational tracking, with highlights on the rotational tracking of optically anisotropic Janus particles. Furthermore, strengths and weaknesses of the various particle tracking methods, and their applications are discussed.

  2. Improvement of the edge rotation diagnostic spectrum analysis via simulation

    SciTech Connect (OSTI)

    Luo, J.; Zhuang, G. Cheng, Z. F.; Zhang, X. L.; Hou, S. Y.; Cheng, C.

    2014-11-15

    The edge rotation diagnostic (ERD) system has been developed on the Joint Texas Experimental Tokamak to measure the edge toroidal rotation velocity by observing the shifted wavelength of carbon V (C V 227.09 nm). Since the measured spectrum is an integrated result along the viewing line from the plasma core to the edge, a method via simulation has been developed to analyze the ERD spectrum. With the necessary parameters such as C V radiation profile and the ion temperature profile, a local rotation profile at the normalized minor radius of 0.5-1 is obtained.

  3. Machine protection system for rotating equipment and method

    DOE Patents [OSTI]

    Lakshminarasimha, Arkalgud N.; Rucigay, Richard J.; Ozgur, Dincer

    2003-01-01

    A machine protection system and method for rotating equipment introduces new alarming features and makes use of full proximity probe sensor information, including amplitude and phase. Baseline vibration amplitude and phase data is estimated and tracked according to operating modes of the rotating equipment. Baseline vibration and phase data can be determined using a rolling average and variance and stored in a unit circle or tracked using short term average and long term average baselines. The sensed vibration amplitude and phase is compared with the baseline vibration amplitude and phase data. Operation of the rotating equipment can be controlled based on the vibration amplitude and phase.

  4. Contrast from rotating frame relaxation by adiabatic pulses

    DOE Patents [OSTI]

    Michaeli, Shalom; Garwood, Michael G.; Ugurbil, Kamil; Sorce, Dennis J.

    2007-10-09

    This document discusses, among other things, a system and method for modulating transverse and longitudinal relaxation time contrast in a rotating frame based on a train of radio frequency pulses.

  5. Reducing collective quantum state rotation errors with reversible dephasing

    SciTech Connect (OSTI)

    Cox, Kevin C.; Norcia, Matthew A.; Weiner, Joshua M.; Bohnet, Justin G.; Thompson, James K.

    2014-12-29

    We demonstrate that reversible dephasing via inhomogeneous broadening can greatly reduce collective quantum state rotation errors, and observe the suppression of rotation errors by more than 21?dB in the context of collective population measurements of the spin states of an ensemble of 2.110{sup 5} laser cooled and trapped {sup 87}Rb atoms. The large reduction in rotation noise enables direct resolution of spin state populations 13(1) dB below the fundamental quantum projection noise limit. Further, the spin state measurement projects the system into an entangled state with 9.5(5) dB of directly observed spectroscopic enhancement (squeezing) relative to the standard quantum limit, whereas no enhancement would have been obtained without the suppression of rotation errors.

  6. A Microscopic Quantal Model for Nuclear Collective Rotation

    SciTech Connect (OSTI)

    Gulshani, P.

    2007-10-26

    A microscopic, quantal model to describe nuclear collective rotation in two dimensions is derived from the many-nucleon Schrodinger equation. The Schrodinger equation is transformed to a body-fixed frame to decompose the Hamiltonian into a sum of intrinsic and rotational components plus a Coriolis-centrifugal coupling term. This Hamiltonian (H) is expressed in terms of space-fixed-frame particle coordinates and momenta by using commutator of H with a rotation angle. A unified-rotational-model type wavefunction is used to obtain an intrinsic Schrodinger equation in terms of angular momentum quantum number and two-body operators. A Hartree-Fock mean-field representation of this equation is then obtained and, by means of a unitary transformation, is reduced to a form resembling that of the conventional semi-classical cranking model when exchange terms and intrinsic spurious collective excitation are ignored.

  7. Registration of the rotation axis in X-ray tomography

    SciTech Connect (OSTI)

    Yang, Yimeng; Yang, Feifei; Hingerl, Ferdinand F.; Xiao, Xianghui; Liu, Yijin; Wu, Ziyu; Benson, Sally M.; Toney, Michael F.; Andrews, Joy C.; Pianetta, Piero A.

    2015-01-01

    There is high demand for efficient, robust and automated routines for tomographic data reduction, particularly for synchrotron data. Registration of the rotation axis in data processing is a critical step affecting the quality of the reconstruction and is not easily implemented with automation. Existing methods for calculating the center of rotation have been reviewed and an improved algorithm to register the rotation axis in tomographic data is presented. The performance of the proposed method is evaluated using synchrotron-based microtomography data on geological samples with and without artificial reduction of the signal-to-noise ratio. The proposed method improves the reconstruction quality by correcting both the tilting error and the translational offset of the rotation axis. The limitation of this promising method is also discussed.

  8. Edge Temperature Gradient as Intrinsic Rotation Drive in Alcator...

    Office of Scientific and Technical Information (OSTI)

    Title: Edge Temperature Gradient as Intrinsic Rotation Drive in Alcator C -Mod Tokamak Plasmas Authors: Rice, J. E. ; Hughes, J. W. ; Diamond, P. H. ; Kosuga, Y. ; Podpaly, Y. A. ; ...

  9. Edge Temperature Gradient as Intrinsic Rotation Drive in AlcatorC...

    Office of Scientific and Technical Information (OSTI)

    Edge Temperature Gradient as Intrinsic Rotation Drive in AlcatorC-Mod Tokamak Plasmas Citation Details In-Document Search Title: Edge Temperature Gradient as Intrinsic Rotation...

  10. The pure rotational spectrum of thorium monosulfide, ThS (Journal...

    Office of Scientific and Technical Information (OSTI)

    The pure rotational spectrum of thorium monosulfide, ThS This content will become publicly available on November 28, 2017 Prev Next Title: The pure rotational spectrum of ...

  11. Self-cleaning rotating anode X-ray source

    DOE Patents [OSTI]

    Paulikas, Arvydas P.

    1989-01-01

    A self-cleaning rotating anode x-ray source comprising an evacuable housing, a rotatable cylindrical anode within the housing, a source of electrons within the housing which electrons are caused to impinge upon the anode to produce x-rays, and means for ionizing residual particles within the housing and accelerating such ions so as to impinge upon the anode to sputter impurities from the surface thereof.

  12. Manipulator for rotating and translating a sample holder

    DOE Patents [OSTI]

    van de Water, Jeroen; van den Oetelaar, Johannes; Wagner, Raymond; Slingerland, Hendrik Nicolaas; Bruggers, Jan Willem; Ottevanger, Adriaan Huibert Dirk; Schmid, Andreas; Olson, Eric A.; Petrov, Ivan G.; Donchev, Todor I.; Duden, Thomas

    2011-02-08

    A manipulator for use in e.g. a Transmission Electron Microscope (TEM) is described, said manipulator capable of rotating and translating a sample holder (4). The manipulator clasps the round sample holder between two members (3A, 3B), said members mounted on actuators (2A, 2B). Moving the actuators in the same direction results in a translation of the sample holder, while moving the actuators in opposite directions results in a rotation of the sample holder.

  13. Apodised aperture using rotation of plane of polarization

    DOE Patents [OSTI]

    Simmons, W.W.; Leppelmeier, G.W.; Johnson, B.C.

    1975-09-01

    An apodised aperture based on the rotation of plane of polarization producing desirable characteristics on a transmitted light beam such as beam profiling in high flux laser amplifier chains is described. The apodised aperture is made with a lossless element by using one or more polarizers and/or analyzers and magneto-optical Faraday means for selectively rotating the plane of polarized radiation over the cross section to effect the desired apodisation. (auth)

  14. Self-cleaning rotating anode x-ray source

    DOE Patents [OSTI]

    Paulikas, A.P.

    1987-06-02

    A self-cleaning rotating anode x-ray source comprising and evacuable housing, a rotatable cylindrical anode within the housing, a source of electrons within the housing which electrons are caused to impinge upon the anode to produce x-rays, and means for ionizing residual particles within the housing and accelerating such ions so as to impinge upon the anode to sputter impurities from the surface thereof. 2 figs.

  15. High-Performance Refrigerator Using Novel Rotating Hear Exchanger

    Broader source: Energy.gov (indexed) [DOE]

    High-Performance Refrigerator Using Novel Rotating Heat Exchanger 2016 Building Technologies Office Peer Review Omar Abdelaziz, abdelazizoa@ornl.gov Oak Ridge National Laboratory 2 Project Summary Timeline: Start date: 10/01/2014 Planned end date: 09/30/2016 Key Milestones 1. Development of the first prototype 2. Successful one-week-long open circuit testing 3. The rotating HX and frost collector unit successfully run and tested for one week Budget: Total Project $ to Date: * DOE: $895,977 *

  16. Critical surface for explosions of rotational core-collapse supernovae

    SciTech Connect (OSTI)

    Iwakami, Wakana; Nagakura, Hiroki [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, 606-8502 (Japan); Yamada, Shoichi, E-mail: wakana@heap.phys.waseda.ac.jp [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo, 169-8555 (Japan)

    2014-09-20

    The effect of rotation on the explosion of core-collapse supernovae is investigated systematically in three-dimensional simulations. In order to obtain the critical conditions for explosion as a function of mass accretion rate, neutrino luminosity, and specific angular momentum, rigidly rotating matter was injected from the outer boundary with an angular momentum, which is increased every 500 ms. It is found that there is a critical value of the specific angular momentum, above which the standing shock wave revives, for a given combination of mass accretion rate and neutrino luminosity, i.e., an explosion can occur by rotation even if the neutrino luminosity is lower than the critical value for a given mass accretion rate in non-rotational models. The coupling of rotation and hydrodynamical instabilities plays an important role in characterizing the dynamics of shock revival for the range of specific angular momentum that are supposed to be realistic. Contrary to expectations from past studies, the most rapidly expanding direction of the shock wave is not aligned with the rotation axis. Being perpendicular to the rotation axis on average, it can be oriented in various directions. Its dispersion is small when the spiral mode of the standing accretion shock instability (SASI) governs the dynamics, while it is large when neutrino-driven convection is dominant. As a result of the comparison between two-dimensional and three-dimensional rotational models, it is found that m ? 0 modes of neutrino-driven convection or SASI are important for shock revival around the critical surface.

  17. Rotation-dependent catastrophic disruption of gravitational aggregates

    SciTech Connect (OSTI)

    Ballouz, Ronald-Louis; Richardson, Derek C.; Schwartz, Stephen R.; Michel, Patrick

    2014-07-10

    We carry out a systematic exploration of the effect of pre-impact rotation on the outcomes of low-speed collisions between planetesimals modeled as gravitational aggregates. We use pkdgrav, a cosmology code adapted to collisional problems and recently enhanced with a new soft-sphere collision algorithm that includes more realistic contact forces. A rotating body has lower effective surface gravity than a non-rotating one and therefore might suffer more mass loss as the result of a collision. What is less well understood, however, is whether rotation systematically increases mass loss on average regardless of the impact trajectory. This has important implications for the efficiency of planet formation via planetesimal growth, and also more generally for the determination of the impact energy threshold for catastrophic disruption (leading to the largest remnant retaining 50% of the original mass), as this has generally only been evaluated for non-spinning bodies. We find that for most collision scenarios, rotation lowers the threshold energy for catastrophic dispersal. For head-on collisions, we develop a semi-analytic description of the change in the threshold description as a function of the target's pre-impact rotation rate, and find that these results are consistent with the 'universal law' of catastrophic disruption developed by Leinhardt and Stewart. Using this approach, we introduce re-scaled catastrophic disruption variables that take into account the interacting mass fraction of the target and the projectile in order to translate oblique impacts into equivalent head-on collisions.

  18. Rotation-induced nonlinear wavepackets in internal waves

    SciTech Connect (OSTI)

    Whitfield, A. J. Johnson, E. R.

    2014-05-15

    The long time effect of weak rotation on an internal solitary wave is the decay into inertia-gravity waves and the eventual formation of a localised wavepacket. Here this initial value problem is considered within the context of the Ostrovsky, or the rotation-modified Korteweg-de Vries (KdV), equation and a numerical method for obtaining accurate wavepacket solutions is presented. The flow evolutions are described in the regimes of relatively-strong and relatively-weak rotational effects. When rotational effects are relatively strong a second-order soliton solution of the nonlinear Schrödinger equation accurately predicts the shape, and phase and group velocities of the numerically determined wavepackets. It is suggested that these solitons may form from a local Benjamin-Feir instability in the inertia-gravity wave-train radiated when a KdV solitary wave rapidly adjusts to the presence of strong rotation. When rotational effects are relatively weak the initial KdV solitary wave remains coherent longer, decaying only slowly due to weak radiation and modulational instability is no longer relevant. Wavepacket solutions in this regime appear to consist of a modulated KdV soliton wavetrain propagating on a slowly varying background of finite extent.

  19. NMR system and method having a permanent magnet providing a rotating magnetic field

    DOE Patents [OSTI]

    Schlueter, Ross D [Berkeley, CA; Budinger, Thomas F [Berkeley, CA

    2009-05-19

    Disclosed herein are systems and methods for generating a rotating magnetic field. The rotating magnetic field can be used to obtain rotating-field NMR spectra, such as magic angle spinning spectra, without having to physically rotate the sample. This result allows magic angle spinning NMR to be conducted on biological samples such as live animals, including humans.

  20. NREL: MIDC/SMUD Anatolia Rotating Shadowband Radiometer (38.55 N, 121.24 W,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    51 m, GMT-8) SMUD Anatolia Irradiance Inc. Rotating Shadowband

  1. Rotational viscometer for high-pressure high-temperature fluids

    DOE Patents [OSTI]

    Carr, Kenneth R.

    1985-01-01

    The invention is a novel rotational viscometer which is well adapted for use with fluids at high temperatures and/or pressures. In one embodiment, the viscometer includes a substantially non-magnetic tube having a closed end and having an open end in communication with a fluid whose viscosity is to be determined. An annular drive magnet is mounted for rotation about the tube. The tube encompasses and supports a rotatable shaft assembly which carries a rotor, or bob, for insertion in the fluid. Affixed to the shaft are (a) a second magnet which is magnetically coupled to the drive magnet and (b) a third magnet. In a typical operation, the drive magnet is rotated to turn the shaft assembly while the shaft rotor is immersed in the fluid. The viscous drag on the rotor causes the shaft assembly to lag the rotation of the drive magnet by an amount which is a function of the amount of viscous drag. A first magnetic pickup generates a waveform whose phase is a function of the angular position of the drive magnet. A second magnetic pickup generates a waveform whose phase is a function of the angular position of the third magnet. An output is generated indicative of the phase difference between the two waveforms.

  2. Rotational viscometer for high-pressure, high-temperature fluids

    DOE Patents [OSTI]

    Carr, K.R.

    1983-06-06

    The invention is a novel rotational viscometer which is well adapted for use with fluids at high temperatures and/or pressures. In one embodiment, the viscometer include a substantially non-magnetic tube having a closed end and having an open end in communication with a fluid whose viscosity is to be determined. An annular drive magnet is mounted for rotation about the tube. The tube encompasses and supports a rotatable shaft assembly which carries a rotor, or bob, for insertion in the fluid. Affixed to the shaft are (a) a second magnet which is magnetically coupled to the drive magnet and (b) a third magnet. In a typical operation, the drive magnet is rotated to turn the shaft assembly while the shaft rotor is immersed in the fluid. The viscous drag on the rotor causes the shaft assembly to lag the rotation of the drive magnet by an amount which is a function of the amount of viscous drag. A first magnetic pickup generates a waveform whose phase is a function of the angular position of the drive magnet. A second magnetic pickup generates a waveform whose phase is a function of the angular position of the third magnet. Means are provided to generate an output indicative of the phase difference between the two waveforms. The viscometer is comparatively simple, inexpensive, rugged, and does not require shaft seals.

  3. JET ROTATION DRIVEN BY MAGNETOHYDRODYNAMIC SHOCKS IN HELICAL MAGNETIC FIELDS

    SciTech Connect (OSTI)

    Fendt, Christian

    2011-08-10

    In this paper, we present a detailed numerical investigation of the hypothesis that a rotation of astrophysical jets can be caused by magnetohydrodynamic (MHD) shocks in a helical magnetic field. Shock compression of the helical magnetic field results in a toroidal Lorentz force component that will accelerate the jet material in the toroidal direction. This process transforms magnetic angular momentum (magnetic stress) carried along the jet into kinetic angular momentum (rotation). The mechanism proposed here only works in a helical magnetic field configuration. We demonstrate the feasibility of this mechanism by axisymmetric MHD simulations in 1.5 and 2.5 dimensions using the PLUTO code. In our setup, the jet is injected into the ambient gas with zero kinetic angular momentum (no rotation). We apply different dynamical parameters for jet propagation such as the jet internal Alfven Mach number and fast magnetosonic Mach number, the density contrast of the jet to the ambient medium, and the external sonic Mach number of the jet. The mechanism we suggest should work for a variety of jet applications, e.g., protostellar or extragalactic jets, and internal jet shocks (jet knots) or external shocks between the jet and the ambient gas (entrainment). For typical parameter values for protostellar jets, the numerically derived rotation feature looks consistent with the observations, i.e., rotational velocities of 0.1%-1% of the jet bulk velocity.

  4. ANALYTICAL CALCULATION OF STOKES PROFILES OF ROTATING STELLAR MAGNETIC DIPOLE

    SciTech Connect (OSTI)

    Martinez Gonzalez, M. J.

    2012-08-20

    The observation of the polarization emerging from a rotating star at different phases opens up the possibility to map the magnetic field in the stellar surface thanks to the well-known Zeeman-Doppler imaging. When the magnetic field is sufficiently weak, the circular and linear polarization profiles locally in each point of the star are proportional to the first and second derivatives of the unperturbed intensity profile, respectively. We show that the weak-field approximation (for weak lines in the case of linear polarization) can be generalized to the case of a rotating star including the Doppler effect and taking into account the integration on the stellar surface. The Stokes profiles are written as a linear combination of wavelength-dependent terms expressed as series expansions in terms of Hermite polynomials. These terms contain the surface-integrated magnetic field and velocity components. The direct numerical evaluation of these quantities is limited to rotation velocities not larger than eight times the Doppler width of the local absorption profiles. Additionally, we demonstrate that in a rotating star, the circular polarization flux depends on the derivative of the intensity flux with respect to the wavelength and also on the profile itself. Likewise, the linear polarization depends on the profile and on its first and second derivatives with respect to the wavelength. We particularize the general expressions to a rotating dipole.

  5. Rotational stability of a long field-reversed configuration

    SciTech Connect (OSTI)

    Barnes, D. C. Steinhauer, L. C.

    2014-02-15

    Rotationally driven modes of long systems with dominantly axial magnetic field are considered. We apply the incompressible model and order axial wavenumber small. A recently developed gyro-viscous model is incorporated. A one-dimensional equilibrium is assumed, but radial profiles are arbitrary. The dominant toroidal (azimuthal) mode numbers ℓ=1 and ℓ=2 modes are examined for a variety of non-reversed (B) and reversed profiles. Previous results for both systems with rigid rotor equilibria are reproduced. New results are obtained by incorporation of finite axial wavenumber and by relaxing the assumption of rigid electron and ion rotation. It is shown that the frequently troublesome ℓ=2 field reversed configuration (FRC) mode is not strongly affected by ion kinetic effects (in contrast to non-reversed cases) and is likely stabilized experimentally only by finite length effects. It is also shown that the ℓ=1 wobble mode has a complicated behavior and is affected by a variety of configuration and profile effects. The rotationally driven ℓ=1 wobble is completely stabilized by strong rotational shear, which is anticipated to be active in high performance FRC experiments. Thus, observed wobble modes in these systems are likely not driven by rotation alone.

  6. Ultra high vacuum heating and rotating specimen stage

    DOE Patents [OSTI]

    Coombs, A.W. III

    1995-05-02

    A heating and rotating specimen stage provides for simultaneous specimen heating and rotating. The stage is ideally suited for operation in ultrahigh vacuum (1{times}10{sup {minus}9} torr or less), but is useful at atmosphere and in pressurized systems as well. A specimen is placed on a specimen holder that is attached to a heater that, in turn, is attached to a top housing. The top housing is rotated relative to a bottom housing and electrically connected thereto by electrically conductive brushes. This stage is made of materials that are compatible with UHV, able to withstand high temperatures, possess low outgassing rates, are gall and seize resistant, and are able to carry substantial electrical loading without overheating. 5 figs.

  7. Rotational order–disorder structure of fluorescent protein FP480

    SciTech Connect (OSTI)

    Pletnev, Sergei; Morozova, Kateryna S.; Verkhusha, Vladislav V.; Dauter, Zbigniew

    2009-09-01

    An analysis of the rotational order–disorder structure of fluorescent protein FP480 is presented. In the last decade, advances in instrumentation and software development have made crystallography a powerful tool in structural biology. Using this method, structural information can now be acquired from pathological crystals that would have been abandoned in earlier times. In this paper, the order–disorder (OD) structure of fluorescent protein FP480 is discussed. The structure is composed of tetramers with 222 symmetry incorporated into the lattice in two different ways, namely rotated 90° with respect to each other around the crystal c axis, with tetramer axes coincident with crystallographic twofold axes. The random distribution of alternatively oriented tetramers in the crystal creates a rotational OD structure with statistically averaged I422 symmetry, although the presence of very weak and diffuse additional reflections suggests that the randomness is only approximate.

  8. A nonlinear calculation of rotating cavitation in inducers

    SciTech Connect (OSTI)

    Tsujimoto, Y. [Osaka Univ., Toyonaka, Osaka (Japan). Dept. of Mechanical Engineering]|[National Aerospace Lab., Kakuda, Miyagi (Japan); Watanabe, S.; Yoshida, Y. [Osaka Univ., Toyonaka, Osaka (Japan); Kamijo, K. [National Aerospace Lab., Kakuda, Miyagi (Japan)

    1996-09-01

    In the previous linear analysis (Tsujimoto et al., 1993) it was found that there can be a backward rotating cavitation as well as a forward mode which rotates faster than impeller. Although some shaft vibration has been observed, which might be caused by the backward mode, experimental evidence has been obtained only for the forward mode. The purpose of the present study is to find out the factors which determine the amplitude of each mode of rotating cavitation by taking into account several nonlinearities. A time marching nonlinear 2-D flow analysis was carried out for this purpose. It was found that the increase of cavitation compliance at lower inlet pressure can be a factor which limits the amplitude. The mode selectivity is mainly dependent on the stability limit obtained by a linear analysis for which the phase delay of cavity has a most important effect.

  9. Regenerative braking device with rotationally mounted energy storage means

    DOE Patents [OSTI]

    Hoppie, Lyle O.

    1982-03-16

    A regenerative braking device for an automotive vehicle includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (30) and an output shaft (32), clutches (50, 56) and brakes (52, 58) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. In a second embodiment the clutches and brakes are dispensed with and the variable ratio transmission is connected directly across the input and output shafts. In both embodiments the rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft rotates faster or relative to the output shaft and are torsionally relaxed to deliver energy to the vehicle when the output shaft rotates faster or relative to the input shaft.

  10. Graphene Monolayer Rotation on Ni(111) Facilities Bilayer Graphene Growth

    SciTech Connect (OSTI)

    Batzill M.; Sutter P.; Dahal, A.; Addou, R.

    2012-06-11

    Synthesis of bilayer graphene by chemical vapor deposition is of importance for graphene-based field effect devices. Here, we demonstrate that bilayer graphene preferentially grows by carbon-segregation under graphene sheets that are rotated relative to a Ni(111) substrate. Rotated graphene monolayer films can be synthesized at growth temperatures above 650 C on a Ni(111) thin-film. The segregated second graphene layer is in registry with the Ni(111) substrate and this suppresses further C-segregation, effectively self-limiting graphene formation to two layers.

  11. A quantum mechanical description of particle spin rotation in channeling

    SciTech Connect (OSTI)

    Silenko, A.Ya.

    1995-04-01

    Spin rotation of spin-1/2 particles involved in planar channeling in straight and bent crystals is described in a consistent quantum mechanical manner. This is done by solving the Dirac equation in the Foldy-Wouthuysen representation, constructing an operator equation of motion for the spin, and calculating the average value of the spin precession frequency. For the case of channeling in bent crystals agreement is observed between the classical and quantum mechanical expressions, provided that the field of the planes is approximated by a harmonic potential. The effect of spin rotation in straight crystals is also examined. 17 refs.

  12. Distributions of methyl group rotational barriers in polycrystalline organic solids

    SciTech Connect (OSTI)

    Beckmann, Peter A. E-mail: wangxianlong@uestc.edu.cn; Conn, Kathleen G.; Division of Education and Human Services, Neumann University, One Neumann Drive, Aston, Pennsylvania 19014-1298 ; Mallory, Clelia W.; Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 ; Mallory, Frank B.; Rheingold, Arnold L.; Rotkina, Lolita; Wang, Xianlong E-mail: wangxianlong@uestc.edu.cn

    2013-11-28

    We bring together solid state {sup 1}H spin-lattice relaxation rate measurements, scanning electron microscopy, single crystal X-ray diffraction, and electronic structure calculations for two methyl substituted organic compounds to investigate methyl group (CH{sub 3}) rotational dynamics in the solid state. Methyl group rotational barrier heights are computed using electronic structure calculations, both in isolated molecules and in molecular clusters mimicking a perfect single crystal environment. The calculations are performed on suitable clusters built from the X-ray diffraction studies. These calculations allow for an estimate of the intramolecular and the intermolecular contributions to the barrier heights. The {sup 1}H relaxation measurements, on the other hand, are performed with polycrystalline samples which have been investigated with scanning electron microscopy. The {sup 1}H relaxation measurements are best fitted with a distribution of activation energies for methyl group rotation and we propose, based on the scanning electron microscopy images, that this distribution arises from molecules near crystallite surfaces or near other crystal imperfections (vacancies, dislocations, etc.). An activation energy characterizing this distribution is compared with a barrier height determined from the electronic structure calculations and a consistent model for methyl group rotation is developed. The compounds are 1,6-dimethylphenanthrene and 1,8-dimethylphenanthrene and the methyl group barriers being discussed and compared are in the 212 kJ?mol{sup ?1} range.

  13. Rotation of the Sacrum During Bellyboard Pelvic Radiotherapy

    SciTech Connect (OSTI)

    Kasabasic, Mladen Faj, Dario; Ivkovic, Ana; Jurkovic, Slaven; Belaj, Nenad

    2010-04-01

    Patients with cervical, uterine, and rectal carcinomas are usually treated in the prone position using the bellyboard positioning device. Specific and uncomfortable prone position gives rise to uncertainties in the daily set-up of patients during the treatment. During investigation of translational movements, rotational movements of the pelvis are observed and investigated. The film portal imaging is used to discover patient positioning errors during treatment. We defined the rotational set-up errors by angle deviations of the sacrum. Thirty-six patients were included in the study; 15 patients were followed during the whole treatment and 21 during the first 5 consecutive treatment days. The image acquisitions were completed in 84%. Systematic and random positioning errors were analyzed in 725 images. Approximately half of the patients had adjusted to the bellyboard in the first few fractions, with sacrum angles remaining the same for the rest of the treatment. The other half had drifts of the sacrum angle during the whole treatment. The rotation of the sacrum during treatment ranged up to 14 deg., causing the usual set-up verification and correction procedure to result in errors up to 15 mm. Rotational movements of the patient pelvis during bellyboard pelvis radiotherapy can introduce considerable patient position error.

  14. Single Particle Orientation and Rotational Tracking (SPORT) in biopysical studies

    SciTech Connect (OSTI)

    Gu, Yan; Ha, Ji Won; Augspurger, Ashley E.; Chen, Kuangcai; Zhu, Shaobin; Fang, Ning

    2013-08-02

    The single particle orientation and rotational tracking (SPORT) techniques have seen rapid development in the past 5 years. Recent technical advances have greatly expanded the applicability of SPORT in biophysical studies. In this feature article, we survey the current development of SPORT and discuss its potential applications in biophysics, including cellular membrane processes and intracellular transport.

  15. Rotating cylinder engine and method of operating the engine

    SciTech Connect (OSTI)

    Schaich, W. A.

    1985-12-17

    Method and apparatus for producing rotation of a power output shaft comprises a plurality of peripherally spaced cylinders disposed in generally tangential relationship to the periphery of a housing defining a cylindrical fluid pressure chamber and connected at their inner ends to such fluid pressure chamber. The housing is mounted on, and co-rotatable with the output shaft. The gas pressure in such chamber is regulated to maintain a selected value above ambient. Cooperating pistons in each of the cylinders are interconnected by connecting rods to a unidirectional clutch mounted in the fluid pressure chamber on a fixed shaft, thus forcing the cylinders to rotate when pressured gas is introduced in the outer ends of the cylinders. Inlet and exhaust valves are provided in a cylinder head mounted in the outer end of each cylinder and are operable by contact with the outer face of the respective piston. A radial exhaust port is uncovered by each piston as it nears the end of its power stroke, thus reducing the fluid pressure on the outer piston face to ambient and permitting the regulated gas pressure in the fluid pressure chamber to effect the return of the pistons to their outermost positions relative to the respective cylinders, thus producing a net unidirectional torque on the housing to rotate the output shaft.

  16. Deriving stellar inclination of slow rotators using stellar activity

    SciTech Connect (OSTI)

    Dumusque, X.

    2014-12-01

    Stellar inclination is an important parameter for many astrophysical studies. Although different techniques allow us to estimate stellar inclination for fast rotators, it becomes much more difficult when stars are rotating slower than ?2-2.5 km s{sup 1}. By using the new activity simulation SOAP 2.0 which can reproduce the photometric and spectroscopic variations induced by stellar activity, we are able to fit observations of solar-type stars and derive their inclination. For HD 189733, we estimate the stellar inclination to be i=84{sub ?20}{sup +6} deg, which implies a star-planet obliquity of ?=4{sub ?4}{sup +18} considering previous measurements of the spin-orbit angle. For ? Cen B, we derive an inclination of i=45{sub ?19}{sup +9}, which implies that the rotational spin of the star is not aligned with the orbital spin of the ? Cen binary system. In addition, assuming that ? Cen Bb is aligned with its host star, no transit would occur. The inclination of ? Cen B can be measured using 40 radial-velocity measurements, which is remarkable given that the projected rotational velocity of the star is smaller than 1.15 km s{sup 1}.

  17. A solar eruption driven by rapid sunspot rotation

    SciTech Connect (OSTI)

    Ruan, Guiping; Chen, Yao; Du, Guohui; Wang, Shuo; Jing, Ju; Wang, Haimin; Zhang, Hongqi; Su, Jiangtao; Xu, Haiqing; Li, Gang; Li, Xing

    2014-04-01

    We present the observation of a major solar eruption that is associated with fast sunspot rotation. The event includes a sigmoidal filament eruption, a coronal mass ejection, and a GOES X2.1 flare from NOAA active region 11283. The filament and some overlying arcades were partially rooted in a sunspot. The sunspot rotated at ?10 hr{sup 1} during a period of 6 hr prior to the eruption. In this period, the filament was found to rise gradually along with the sunspot rotation. Based on the Helioseismic and Magnetic Imager observation, for an area along the polarity inversion line underneath the filament, we found gradual pre-eruption decreases of both the mean strength of the photospheric horizontal field (B{sub h} ) and the mean inclination angle between the vector magnetic field and the local radial (or vertical) direction. These observations are consistent with the pre-eruption gradual rising of the filament-associated magnetic structure. In addition, according to the nonlinear force-free field reconstruction of the coronal magnetic field, a pre-eruption magnetic flux rope structure is found to be in alignment with the filament, and a considerable amount of magnetic energy was transported to the corona during the period of sunspot rotation. Our study provides evidence that in this event sunspot rotation plays an important role in twisting, energizing, and destabilizing the coronal filament-flux rope system, and led to the eruption. We also propose that the pre-event evolution of B{sub h} may be used to discern the driving mechanism of eruptions.

  18. Multilayered Glass Fibre-reinforced Composites In Rotational Moulding

    SciTech Connect (OSTI)

    Chang, W. C.; Harkin-Jones, E. [School of Mechanical and Aerospace Engineering, Queen's University Belfast, Ashby Building, Stranmillis Road, Belfast BT9 5AH, Northern Ireland (United Kingdom); Kearns, M.; McCourt, M. [Polymer Processing Research Centre, Queen's University Belfast, Ashby Building, Stranmillis Road, Belfast BT9 5AH Northern Ireland (United Kingdom)

    2011-05-04

    The potential of multiple layer fibre-reinforced mouldings is of growing interest to the rotational moulding industry because of their cost/performance ratio. The particular problem that arises when using reinforcements in this process relate to the fact that the process is low shear and good mixing of resin and reinforcement is not optimum under those conditions. There is also a problem of the larger/heavier reinforcing agents segregating out of the powder to lay up on the inner part surface. In this study, short glass fibres were incorporated and distributed into a polymer matrix to produce fibre-reinforced polymer composites using the rotational moulding process and characterised in terms of morphology and mechanical properties.

  19. Rotational Brownian Dynamics simulations of clathrin cage formation

    SciTech Connect (OSTI)

    Ilie, Ioana M.; Briels, Wim J.; Otter, Wouter K. den

    2014-08-14

    The self-assembly of nearly rigid proteins into ordered aggregates is well suited for modeling by the patchy particle approach. Patchy particles are traditionally simulated using Monte Carlo methods, to study the phase diagram, while Brownian Dynamics simulations would reveal insights into the assembly dynamics. However, Brownian Dynamics of rotating anisotropic particles gives rise to a number of complications not encountered in translational Brownian Dynamics. We thoroughly test the Rotational Brownian Dynamics scheme proposed by Naess and Elsgaeter [Macromol. Theory Simul. 13, 419 (2004); Naess and Elsgaeter Macromol. Theory Simul. 14, 300 (2005)], confirming its validity. We then apply the algorithm to simulate a patchy particle model of clathrin, a three-legged protein involved in vesicle production from lipid membranes during endocytosis. Using this algorithm we recover time scales for cage assembly comparable to those from experiments. We also briefly discuss the undulatory dynamics of the polyhedral cage.

  20. A high precision, compact electromechanical ground rotation sensor

    SciTech Connect (OSTI)

    Dergachev, V.; DeSalvo, R.; University of Sannio, C.so Garibaldi 107, Benevento 82100 ; Asadoor, M.; Oklahoma State University, 219 Student Union, Stillwater, Oklahoma 74074 ; Bhawal, A.; Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213 ; Gong, P.; School of Industrial and System Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0205 ; Kim, C.; Lottarini, A.; Department of Computer Science, Columbia University, 1214 Amsterdam Avenue, New York, New York 10027 ; Minenkov, Y.; Murphy, C.; University of Melbourne Grattan Street, Parkville VIC 3010 ; O'Toole, A.; Michigan Technological University, 1400 Townsend Dr, Houghton, Michigan 49931 ; Peña Arellano, F. E.; and others

    2014-05-15

    We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor of 1 × 10{sup −11}m/√( Hz ). We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of 5.7 × 10{sup −9} rad /√( Hz ) at 10 mHz and 6.4 × 10{sup −10} rad /√( Hz ) at 0.1 Hz. The performance of the knife edge hinge is compatible with a behaviorur free of noise from dislocation self-organized criticality.

  1. Aerodynamic testing of a rotating wind turbine blade

    SciTech Connect (OSTI)

    Butterfield, C.P.; Nelsen, E.N.

    1990-01-01

    Aerodynamic, load, flow-visualization, and inflow measurements were taken on a downwind horizontal-axis wind turbine (HAWT). A video camera mounted on the rotor recorded video images of tufts attached to the low-pressure side of the blade. Strain gages, mounted every 10% of the blade's span, provided load and pressure measurements. Pressure taps at 32 chordwise positions recorded pressure distributions. Wind inflow was measured via a vertical-plane array of anemometers located 10 m upwind. The objectives of the test were to address whether airfoil pressure distributions measured on a rotating blade differed from those measured in the wind tunnel, if radial flow near or in the boundary layer of the airfoil affected pressure distributions, if dynamic stall could result in increased dynamic loads, and if the location of the separation boundary measured on the rotating blade agreed with that measured in two-dimensional flow in the wind tunnel. 6 refs., 9 figs., 1 tab.

  2. PIC simulation of electrodeless plasma thruster with rotating electric field

    SciTech Connect (OSTI)

    Nomura, Ryosuke; Ohnishi, Naofumi; Nishida, Hiroyuki

    2012-11-27

    For longer lifetime of electric propulsion system, an electrodeless plasma thruster with rotating electric field have been proposed utilizing a helicon plasma source. The rotating electric field may produce so-called Lissajous acceleration of helicon plasma in the presence of diverging magnetic field through a complicated mechanism originating from many parameters. Two-dimensional simulations of the Lissajous acceleration were conducted by a code based on Particle-In-Cell (PIC) method and Monte Carlo Collision (MCC) method for understanding plasma motion in acceleration area and for finding the optimal condition. Obtained results show that azimuthal current depends on ratio of electron drift radius to plasma region length, AC frequency, and axial magnetic field. When ratio of cyclotron frequency to the AC frequency is higher than unity, reduction of the azimuthal current by collision effect is little or nothing.

  3. Electron inertial effects on rotating magnetic field current drive

    SciTech Connect (OSTI)

    Ferrari, Hugo E.; Farengo, Ricardo; Clemente, Roberto A.

    2006-03-15

    The effect of finite electron mass on the formation and sustainment of a field reversed configuration (FRC) by rotating magnetic fields (RMF) is studied. The importance of inertial effects is measured by the ratio between the RMF frequency ({omega}) and the electron-ion collision frequency ({nu}). In the limit where this ratio is very small ({omega}/{nu}{yields}0), previous results corresponding to massless electrons are recovered. When {omega}/{nu} increases there are significant changes in the value of the minimum external rotating field needed to sustain the FRC and the time required to reach a steady state. Since {nu} decreases with increasing temperature and decreasing density, these effects are expected to become more important as fusion relevant temperatures are approached.

  4. Electron beam machining using rotating and shaped beam power distribution

    DOE Patents [OSTI]

    Elmer, John W.; O'Brien, Dennis W.

    1996-01-01

    An apparatus and method for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: 1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and 2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1000 .mu.m (1 mm or larger), compared to the 250 .mu.m diameter of laser drilling.

  5. Electron beam machining using rotating and shaped beam power distribution

    DOE Patents [OSTI]

    Elmer, J.W.; O`Brien, D.W.

    1996-07-09

    An apparatus and method are disclosed for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: (1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and (2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1,000 {micro}m (1 mm or larger), compared to the 250 {micro}m diameter of laser drilling. 5 figs.

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

    DOE Patents [OSTI]

    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.

  7. Neutronics analyses in support of rotating target developments at SNS

    SciTech Connect (OSTI)

    Gallmeier, Franz X.

    2010-03-08

    A second target station (STS) for Spallation Neutron Souce (SNS) very likely being operated in long-pulse mode is in the early design phase, will complement the ORNL neutron sources, which presently consist of a short-pulse spallation source and the HFIR research reactor. As an alternative to the stationary liquid metal target, a rotating target is being considered. Neutronics studies in support of a 3MW power 20 Hz repetition rate rotating target feasibility study funded through the laboratory LDRD program, was extended towards a 1.5 MW STS design. The scope of work included in-operation heat deposition rates in target structures for thermal and structural analyses, target radionuclide inventory for decay heat and safety analyses, lifetime estimations due to radiation-driven material damage of target and moderator components, moderator neutron performance and moderator cryogenic heatloads.

  8. X- And y-axis driver for rotating microspheres

    DOE Patents [OSTI]

    Weinstein, Berthold W.

    1979-01-01

    Apparatus for precise control of the motion and position of microspheres for examination of their interior and/or exterior. The apparatus includes an x- and y-axis driver mechanism controlled, for example, by a minicomputer for selectively rotating microspheres retained between a pair of manipulator arms having flat, smooth end surfaces. The driver mechanism includes an apertured plate and ball arrangement which provided for coupled equal and opposite movement of the manipulator arms in two perpendicular directions.

  9. An Advanced Liquid Centrifuge Using Differentially Rotating Cylinders and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Optimized Boundary Conditions --- Inventor(s) Hantao Ji, Adam Cohen, Phil Efthimion and Eric Edlund | Princeton Plasma Physics Lab An Advanced Liquid Centrifuge Using Differentially Rotating Cylinders and Optimized Boundary Conditions --- Inventor(s) Hantao Ji, Adam Cohen, Phil Efthimion and Eric Edlund This invention discloses a concept for an advanced centrifugal contactor which can be used for (1) mixing of two or more component fluid substances to produce a uniform mixture or enhance the

  10. Evaporative cooler including one or more rotating cooler louvers

    DOE Patents [OSTI]

    Gerlach, David W

    2015-02-03

    An evaporative cooler may include an evaporative cooler housing with a duct extending therethrough, a plurality of cooler louvers with respective porous evaporative cooler pads, and a working fluid source conduit. The cooler louvers are arranged within the duct and rotatably connected to the cooler housing along respective louver axes. The source conduit provides an evaporative cooler working fluid to the cooler pads during at least one mode of operation.

  11. Large-scale anisotropy in stably stratified rotating flows

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Marino, R.; Mininni, P. D.; Rosenberg, D. L.; Pouquet, A.

    2014-08-28

    We present results from direct numerical simulations of the Boussinesq equations in the presence of rotation and/or stratification, both in the vertical direction. The runs are forced isotropically and randomly at small scales and have spatial resolutions of up tomore » $1024^3$ grid points and Reynolds numbers of $$\\approx 1000$$. We first show that solutions with negative energy flux and inverse cascades develop in rotating turbulence, whether or not stratification is present. However, the purely stratified case is characterized instead by an early-time, highly anisotropic transfer to large scales with almost zero net isotropic energy flux. This is consistent with previous studies that observed the development of vertically sheared horizontal winds, although only at substantially later times. However, and unlike previous works, when sufficient scale separation is allowed between the forcing scale and the domain size, the total energy displays a perpendicular (horizontal) spectrum with power law behavior compatible with $$\\sim k_\\perp^{-5/3}$$, including in the absence of rotation. In this latter purely stratified case, such a spectrum is the result of a direct cascade of the energy contained in the large-scale horizontal wind, as is evidenced by a strong positive flux of energy in the parallel direction at all scales including the largest resolved scales.« less

  12. Rotating machinery surveillance system reduces plant downtime and radiation exposure

    SciTech Connect (OSTI)

    Bohanick, J.S.; Robinson, J.C.; Allen, J.W.

    1988-01-01

    A rotating machinery surveillance system (RMSS) was permanently installed at Grand Gulf nuclear station (GGNS) as part of a program sponsored by the US Department of Energy whose goal was to reduce radiation exposure to power plant personnel resulting from the inspection, maintenance, and repair of rotating machinery. The RMSS was installed at GGNS in 1983 to continuously monitor 173 analog vibration signals from proximity probes mounted on 26 machine trains and {approximately}450 process data points via a computer data link. Vibration frequency spectra, i.e., the vibration amplitude versus frequency of vibration, and various characterizations of these spectra are the fundamental data collected by the RMSS for performing machinery diagnostics. The RMSS collects vibration frequency spectra on a daily basis for all the monitored rotating equipment and automatically stores the collected spectra for review by the vibration engineer. Vibration spectra automatically stored by the RMSS fall into categories that include the last normal, alarm, minimum and maximum, past three-day data set, baseline, current, and user-saved spectra. During first and second fuel-cycle operation at GGNS, several significant vibration problems were detected by the RMSS. Two of these are presented in this paper: recirculation pumps and turbine-generator bearing degradation. The total reduction in personnel radiation exposure at GGNS from 1985 to 1987 due to the presence of the RMSS was estimated to be in the range from 49 to 54 person-rem.

  13. Rotational position detecting device for internal combustion engine

    SciTech Connect (OSTI)

    Ushida, M.; Nakamura, Y.; Abe, K.

    1986-11-04

    This patent describes a device for detecting the rotational position of an internal combustion engine of the type that has a cam shaft extending outwardly from the engine through a wall of the engine block and a rotary member fixed to the cam shaft and driven therewith by a crankshaft of the engine. The device comprises: reference position information means and angular position information means both fixed to the end face of the driven rotary member remote from the wall of the engine block. In this way, the reference position and angular position information means are both moved among circular paths when the rotary member is rotated. The reference position and angular position information means are disposed at different radial distances from the axis of the driven rotary member; a reference position sensor and an angular position sensor respectively disposed to face the circular paths of the reference position and angular position information means; a housing fixed to the engine block to cover the driven rotary member and support the sensors; the housing having an end wall formed therein with an opening coaxial with the cam shaft; the cam shaft having an outer end portion extending outwardly beyond the driven rotary member into and through the opening; and a bearing mounted in the opening to rotatably receive the outer end portion of the cam shaft and position the housing with respect to the cam shaft.

  14. Rotational and translational temperature equilibrium in an inductively coupled plasma

    SciTech Connect (OSTI)

    Shimada, Masashi; Tynan, George R.; Cattolica, Robert

    2006-09-15

    Rotational temperature has been used widely as neutral gas temperature measurement in different types of plasmas (electron cyclotron resonance, inductively coupled plasma, helicon, hollow cathode, etc.), and has been assumed to be in equilibrium with translational temperature. The direct experimental comparison of rotational and translational temperature in low-temperature plasmas has not been reported. In this research, optical emission spectroscopy is used to measure the neutral gas rotational temperature, T{sub rot}, from the second-positive band of a nitrogen molecule (380 nm). The results are compared with the Doppler-broadened translational temperature, T{sub trans}, of Ar (750 nm) and He (587 nm), determined with a high-resolution spectrometer at various partial pressures of N{sub 2} in Ar/N{sub 2} and He/N{sub 2} plasmas. The results demonstrated that T{sub rot} and T{sub trans} are in equilibrium in the conditions [10{sup 10}

  15. HOW CAN NEWLY BORN RAPIDLY ROTATING NEUTRON STARS BECOME MAGNETARS?

    SciTech Connect (OSTI)

    Cheng, Quan; Yu, Yun-Wei

    2014-05-10

    In a newly born (high-temperature and Keplerian rotating) neutron star, r-mode instability can lead to stellar differential rotation, which winds the seed poloidal magnetic field (∼10{sup 11} G) to generate an ultra-high (∼10{sup 17} G) toroidal field component. Subsequently, by succumbing to the Tayler instability, the toroidal field could be partially transformed into a new poloidal field. Through such dynamo processes, the newly born neutron star with sufficiently rapid rotation could become a magnetar on a timescale of ∼10{sup 2} {sup –} {sup 3} s, with a surface dipolar magnetic field of ∼10{sup 15} G. Accompanying the field amplification, the star could spin down to a period of ∼5 ms through gravitational wave radiation due to the r-mode instability and, in particular, the non-axisymmetric stellar deformation caused by the toroidal field. This scenario provides a possible explanation for why the remnant neutron stars formed in gamma-ray bursts and superluminous supernovae could be millisecond magnetars.

  16. A nonlinear calculation of rotating cavitation in inducers

    SciTech Connect (OSTI)

    Tsujimoto, Y.; Watanabe, S.; Yoshida, Y. [Osaka Univ., Osaka (Japan); Kamijo, K. [Kakuda Research Center (Japan). Rocket Propulsion Division

    1994-12-31

    In the previous linear analysis (Tsujimoto et al., 1993) it was found that there can be a backward rotating cavitation as well as a forward mode which rotates faster than impeller. Although some shaft vibration has been observed which might be caused by the backward mode, experimental evidence has been obtained only for the forward mode. The ultimate goal of the present study is to answer the question which mode of the cavitation instabilities -- cavitation surge and the two modes of rotating cavitation -- occurs in a given system and operating condition, and to find out analytical method to determine their amplitude. A time marching non-linear 2-D flow analysis was carried out for this purpose. It was found that the increase of cavitation compliance at lower inlet pressure can be a factor which limits the amplitude. The mode selectivity is mainly dependent on the stability limit obtained by a linear analysis for which the phase delay of cavity has a most important effect.

  17. System for automatically aligning a support roller system under a rotating body

    DOE Patents [OSTI]

    Singletary, B.H.

    1982-07-21

    Two support rings on a rotatable drum respectively engage conically tapered end surfaces of support rollers mounted on pivot universally relative to its axis of rotation and translate therealong. Rotation of the drum on differential conical support roller diameters causes pivotal steering and axial translation of support roller until roller is centered on support rings.

  18. System for automatically aligning a support roller system under a rotating body

    DOE Patents [OSTI]

    Singletary, B. Huston (Oak Ridge, TN)

    1983-01-01

    Two support rings on a rotatable drum respectively engage conically tapered nd surfaces of support rollers mounted on pivot universally relative to its axis of rotation and translate therealong. Rotation of the drum on differential conical support roller diameters causes pivotal steering and axial translation of support roller until roller is centered on support rings.

  19. Systems and assemblies for transferring high power laser energy through a rotating junction

    DOE Patents [OSTI]

    Norton, Ryan J.; McKay, Ryan P.; Fraze, Jason D.; Rinzler, Charles C.; Grubb, Daryl L.; Faircloth, Brian O.; Zediker, Mark S.

    2016-01-26

    There are provided high power laser devices and systems for transmitting a high power laser beam across a rotating assembly, including optical slip rings and optical rotational coupling assemblies. These devices can transmit the laser beam through the rotation zone in free space or within a fiber.

  20. Rotational fluctuation of molecules in quantum clusters. II. Molecular rotation and superfluidity in OCS-doped helium-4 clusters

    SciTech Connect (OSTI)

    Miura, Shinichi [Institute for Molecular Science, 38 Myodaiji, Okazaki 444-8585 (Japan)

    2007-03-21

    In this paper, quantum fluctuations of a carbonyl sulfide molecule in helium-4 clusters are studied as a function of cluster size N in a small-to-large size regime (2{<=}N{<=}64). The molecular rotation of the dopant shows nonmonotonic size dependence in the range of 10{<=}N{<=}20, reflecting the density distribution of the helium atoms around the molecule. The size dependence on the rotational constant shows a plateau for N{>=}20, which is larger than the experimental nanodroplet value. Superfluid response of the doped cluster is found to show remarkable anisotropy especially for N{<=}20. The superfluid fraction regarding the axis perpendicular to the molecular axis shows a steep increase at N=10, giving the significant enhancement of the rotational fluctuation of the molecule. On the other hand, the superfluid fraction regarding the axis parallel to the molecular axis reaches 0.9 at N=5, arising from the bosonic exchange cycles of the helium atoms around the molecular axis. The anisotropy in the superfluid response is found to be the direct consequence of the configurations of the bosonic exchange cycles.

  1. Accurate rotational constant and bond lengths of hexafluorobenzene by femtosecond rotational Raman coherence spectroscopy and ab initio calculations

    SciTech Connect (OSTI)

    Den, Takuya S.; Frey, Hans-Martin; Leutwyler, Samuel

    2014-11-21

    The gas-phase rotational motion of hexafluorobenzene has been measured in real time using femtosecond (fs) time-resolved rotational Raman coherence spectroscopy (RR-RCS) at T = 100 and 295 K. This four-wave mixing method allows to probe the rotation of non-polar gas-phase molecules with fs time resolution over times up to ∼5 ns. The ground state rotational constant of hexafluorobenzene is determined as B{sub 0} = 1029.740(28) MHz (2σ uncertainty) from RR-RCS transients measured in a pulsed seeded supersonic jet, where essentially only the v = 0 state is populated. Using this B{sub 0} value, RR-RCS measurements in a room temperature gas cell give the rotational constants B{sub v} of the five lowest-lying thermally populated vibrationally excited states ν{sub 7/8}, ν{sub 9}, ν{sub 11/12}, ν{sub 13}, and ν{sub 14/15}. Their B{sub v} constants differ from B{sub 0} by between −1.02 MHz and +2.23 MHz. Combining the B{sub 0} with the results of all-electron coupled-cluster CCSD(T) calculations of Demaison et al. [Mol. Phys. 111, 1539 (2013)] and of our own allow to determine the C-C and C-F semi-experimental equilibrium bond lengths r{sub e}(C-C) = 1.3866(3) Å and r{sub e}(C-F) = 1.3244(4) Å. These agree with the CCSD(T)/wCVQZ r{sub e} bond lengths calculated by Demaison et al. within ±0.0005 Å. We also calculate the semi-experimental thermally averaged bond lengths r{sub g}(C-C)=1.3907(3) Å and r{sub g}(C-F)=1.3250(4) Å. These are at least ten times more accurate than two sets of experimental gas-phase electron diffraction r{sub g} bond lengths measured in the 1960s.

  2. Observation of dust torus with poloidal rotation in direct current glow discharge plasma

    SciTech Connect (OSTI)

    Kaur, Manjit Bose, Sayak; Chattopadhyay, P. K. Sharma, Devendra; Ghosh, J.; Saxena, Y. C.

    2015-03-15

    Observation of dust cloud rotation in parallel-plate DC glow discharge plasma is reported here. The experiments are carried out at high pressures (∼130 Pa) with a metallic ring placed on the lower electrode (cathode). The dust cloud rotates poloidally in the vertical plane near the cathode surface. This structure is continuous toroidally. Absence of magnetic field rules out the possibility of E × B induced ion flow as the cause of dust rotation. The dust rotational structures exist even with water cooled cathode. Therefore, temperature gradient driven mechanisms, such as thermophoretic force, thermal creep flow, and free convection cannot be causing the observed dust rotation. Langmuir probe measurement reveals the existence of a sharp density gradient near the location of the rotating dust cloud. The gradient in the density, giving rise to a gradient in the ion drag force, has been identified as the principal cause behind the rotation of dust particles.

  3. Rotation of solar magnetic fields for the current solar cycle 24

    SciTech Connect (OSTI)

    Shi, X. J.; Xie, J. L.

    2014-11-01

    The rotation of solar magnetic fields for the current solar cycle 24 is investigated through a cross-correlation analysis of the Carrington synoptic maps of solar photospheric magnetic fields during Carrington rotation numbers 2076-2146 (2008 October to 2014 January). The sidereal rotation rates of positive and negative magnetic fields at some latitudes are shown, and it can be found that the positive (negative) fields generally rotate faster than the negative (positive) fields in the southern (northern) hemisphere at low latitudes. The mean rotation profiles of total, positive, and negative magnetic fields between ±60° latitudes in the time interval are also obtained. It should be noted that both of the mean rotation profiles of the positive and negative magnetic fields, as well as the mean rotation profile of the total magnetic field, exhibit a quasi-rigid rotation at latitudes above about 55°. The mean rotation rates of the positive (negative) polarity reach their maximum values at about 9°(6)° latitude in the southern (northern) hemisphere. The mean rotation profile of the total magnetic field displays an obvious north-south asymmetry, where the rotation seems to be more differential in the northern hemisphere. The latitude variation in the rotation rate differences between positive and negative magnetic fields is further studied, and it is found that magnetic fields with the same polarity as the leading sunspots at a given hemisphere rotate faster than those with the opposite polarity, except for the zones around 52° latitude of the southern hemisphere and around 35° latitude of the northern hemisphere. The implication of these results is discussed. It is clear that the obtained results can provide some observational constraints on the theoretical research of the mechanisms of differential rotation and solar cycle.

  4. Unusual aryl-porphyrin rotational barriers in peripherally crowded porphyrins.

    SciTech Connect (OSTI)

    Shyr, David C.; Dooley, Neal R.; Haddad, Raid Edward; Shelnutt, John Allen; Muzzi, Cinzia M.; Ma, Jian-Guo; Olmstead, Marilyn M.; Jaquinod, Laurent A.; Nurco, Daniel J.; Medforth, Craig John; Smith, Kevin M.

    2003-06-01

    Previous studies of 5,10,15,20-tetraarylporphyrins have shown that the barrier for meso aryl-porphyrin rotation ({Delta}G{sub ROT}) varies as a function of the core substituent M and is lower for a small metal (M = Ni) compared to a large metal (M = Zn) and for a dication (M 4H{sup 2+}) versus a free base porphyrin (M = 2H). This has been attributed to changes in the nonplanar distortion of the porphyrin ring and the deformability of the macrocycle caused by the core substituent. In the present work, X-ray crystallography, molecular mechanics (MM) calculations, and variable temperature (VT) {sup 1}H NMR spectroscopy are used to examine the relationship between the aryl-porphyrin rotational barrier and the core substituent M in some novel 2,3,5,7,8,10,12,13,15,17,18,20-dodecaarylporphyrins (DArPs), and specifically in some 5,10,15,20-tetraaryl-2,3,7,8,12,13,17,18-octaphenylporphyrins (TArOPPs), where steric crowding of the peripheral groups always results in a very nonplanar macrocycle. X-ray structures of DArPs indicate differences in the nonplanar conformation of the macrocycle as a function of M, with saddle conformations being observed for M = Zn, 2H or M = 4H{sup 2+} and saddle and/or ruffle conformations for M = Ni. VT NMR studies show that the effect of protonation in the TArOPPs is to increase {Delta}G{sub ROT}, which is the opposite of the effect seen for the TArPs, and MM calculations also predict a strikingly high barrier for the TArOPPs when M = 4H{sup 2+}. These and other findings suggest that the aryl-porphyrin rotational barriers in the DArPs are closely linked to the deformability of the macrocycle along a nonplanar distortion mode which moves the substituent being rotated out of the porphyrin plane.

  5. Stator for a rotating electrical machine having multiple control windings

    DOE Patents [OSTI]

    Shah, Manoj R.; Lewandowski, Chad R.

    2001-07-17

    A rotating electric machine is provided which includes multiple independent control windings for compensating for rotor imbalances and for levitating/centering the rotor. The multiple independent control windings are placed at different axial locations along the rotor to oppose forces created by imbalances at different axial locations along the rotor. The multiple control windings can also be used to levitate/center the rotor with a relatively small magnetic field per unit area since the rotor and/or the main power winding provides the bias field.

  6. Negative energy waves and MHD stability of rotating plasmas

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    energy waves and MHD stability of rotating plasmas This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2009 Nucl. Fusion 49 035008 (http://iopscience.iop.org/0029-5515/49/3/035008) Download details: IP Address: 128.104.166.218 The article was downloaded on 15/04/2013 at 17:54 Please note that terms and conditions apply. View the table of contents for this issue, or go to the journal homepage for more Home Search Collections Journals About Contact us

  7. Ion acoustic shocks in magneto rotating Lorentzian plasmas

    SciTech Connect (OSTI)

    Hussain, S.; Akhtar, N.; Hasnain, H.

    2014-12-15

    Ion acoustic shock structures in magnetized homogeneous dissipative Lorentzian plasma under the effects of Coriolis force are investigated. The dissipation in the plasma system is introduced via dynamic viscosity of inertial ions. The electrons are following the kappa distribution function. Korteweg-de Vries Burger (KdVB) equation is derived by using reductive perturbation technique. It is shown that spectral index, magnetic field, kinematic viscosity of ions, rotational frequency, and effective frequency have significant impact on the propagation characteristic of ion acoustic shocks in such plasma system. The numerical solution of KdVB equation is also discussed and transition from oscillatory profile to monotonic shock for different plasma parameters is investigated.

  8. Control coil arrangement for a rotating machine rotor

    DOE Patents [OSTI]

    Shah, Manoj R.; Lewandowsk, Chad R.

    2001-07-31

    A rotating machine (e.g., a turbine, motor or generator) is provided wherein a fixed solenoid or other coil configuration is disposed adjacent to one or both ends of the active portion of the machine rotor for producing an axially directed flux in the active portion so as to provide planar axial control at single or multiple locations for rotor balance, levitation, centering, torque and thrust action. Permanent magnets can be used to produce an axial bias magnetic field. The rotor can include magnetic disks disposed in opposed, facing relation to the coil configuration.

  9. Electromagnetic Detection and Real-Time DMLC Adaptation to Target Rotation During Radiotherapy

    SciTech Connect (OSTI)

    Wu Junqing; Ruan, Dan; Cho, Byungchul; Sawant, Amit; Petersen, Jay; Newell, Laurence J.; Cattell, Herbert; Keall, Paul J.

    2012-03-01

    Purpose: Intrafraction rotation of more than 45 Degree-Sign and 25 Degree-Sign has been observed for lung and prostate tumors, respectively. Such rotation is not routinely adapted to during current radiotherapy, which may compromise tumor dose coverage. The aim of the study was to investigate the geometric and dosimetric performance of an electromagnetically guided real-time dynamic multileaf collimator (DMLC) tracking system to adapt to intrafractional tumor rotation. Materials/Methods: Target rotation was provided by changing the treatment couch angle. The target rotation was measured by a research Calypso system integrated with a real-time DMLC tracking system employed on a Varian linac. The geometric beam-target rotational alignment difference was measured using electronic portal images. The dosimetric accuracy was quantified using a two-dimensional ion chamber array. For each beam, the following five delivery modes were tested: 1) nonrotated target (reference); 2) fixed rotated target with tracking; 3) fixed rotated target without tracking; 4) actively rotating target with tracking; and 5) actively rotating target without tracking. Dosimetric performance of the latter four modes was measured and compared to the reference dose distribution using a 3 mm/3% {gamma}-test. Results: Geometrically, the beam-target rotational alignment difference was 0.3 Degree-Sign {+-} 0.6 Degree-Sign for fixed rotation and 0.3 Degree-Sign {+-} 1.3 Degree-Sign for active rotation. Dosimetrically, the average failure rate for the {gamma}-test for a fixed rotated target was 11% with tracking and 36% without tracking. The average failure rate for an actively rotating target was 9% with tracking and 35% without tracking. Conclusions: For the first time, real-time target rotation has been accurately detected and adapted to during radiation delivery via DMLC tracking. The beam-target rotational alignment difference was mostly within 1 Degree-Sign . Dose distributions to fixed and actively

  10. Apparatus for high speed rotation of electrically operated devices

    DOE Patents [OSTI]

    Williams, Keith E.; Rogus, Arnold J.

    1976-10-26

    Most high speed centrifuges employ a relatively small diameter elongate flexible drive shaft, sometimes called a "quill" shaft. These relatively slender shafts are flexible to absorb vibration as the assembly passes through speeds of resonance and to permit re-alignment of the axis of rotation of the shaft and the rotor driven thereby in the event the center of mass of the rotor and shaft assembly is displaced from the nominal axis of the rotation. To use such an apparatus for testing electrical devices and components, electrical conductors for wires are passed from a slip ring assembly located at an end of the quill shaft remote from the rotor and longitudinally alongside the quill shaft to the electrical device mounted on the rotor. The longitudinally extending conductors are supported against the radially outward directed centrifugal forces by a plurality of strong, self-lubricating, slightly compressible wafers or washers co-axially stacked on the slender shaft and provided with radially offset longitudinally aligned openings to support the longitudinally extending conductors. The conductors are supported against the centrifugal forces and thus protected from rupture or other damage without restricting or constraining the essential flexure or bending of the drive shaft.

  11. Effect of MLC leaf position, collimator rotation angle, and gantry rotation angle errors on intensity-modulated radiotherapy plans for nasopharyngeal carcinoma

    SciTech Connect (OSTI)

    Bai, Sen; Li, Guangjun; Wang, Maojie; Jiang, Qinfeng; Zhang, Yingjie; Wei, Yuquan

    2013-07-01

    The purpose of this study was to investigate the effect of multileaf collimator (MLC) leaf position, collimator rotation angle, and accelerator gantry rotation angle errors on intensity-modulated radiotherapy plans for nasopharyngeal carcinoma. To compare dosimetric differences between the simulating plans and the clinical plans with evaluation parameters, 6 patients with nasopharyngeal carcinoma were selected for simulation of systematic and random MLC leaf position errors, collimator rotation angle errors, and accelerator gantry rotation angle errors. There was a high sensitivity to dose distribution for systematic MLC leaf position errors in response to field size. When the systematic MLC position errors were 0.5, 1, and 2 mm, respectively, the maximum values of the mean dose deviation, observed in parotid glands, were 4.63%, 8.69%, and 18.32%, respectively. The dosimetric effect was comparatively small for systematic MLC shift errors. For random MLC errors up to 2 mm and collimator and gantry rotation angle errors up to 0.5°, the dosimetric effect was negligible. We suggest that quality control be regularly conducted for MLC leaves, so as to ensure that systematic MLC leaf position errors are within 0.5 mm. Because the dosimetric effect of 0.5° collimator and gantry rotation angle errors is negligible, it can be concluded that setting a proper threshold for allowed errors of collimator and gantry rotation angle may increase treatment efficacy and reduce treatment time.

  12. Unstable domains of tearing and Kelvin-Helmholtz instabilities in a rotating cylindrical plasma

    SciTech Connect (OSTI)

    Fan, D. M.; Wei, L.; Wang, Z. X. Zheng, S.; Duan, P.

    2014-09-15

    Effects of poloidal rotation profile on tearing and Kelvin-Helmholtz (KH) instabilities in a cylindrical plasma are investigated by using a reduced magnetohydrodynamic model. Since the poloidal rotation has different effects on the tearing and KH modes in different rotation regimes, four unstable domains are numerically identified, i.e., the destabilized tearing mode domain, stabilized tearing mode domain, stable-window domain, and unstable KH mode domain. It is also found that when the rotation layer is in the outer region of the rational surface, the stabilizing role of the rotation can be enhanced so significantly that the stable window domain is enlarged. Moreover, Alfvén resonances can be induced by the tearing and KH modes in such rotating plasmas. Radially wide profiles of current and vorticity perturbations can be formed when multiple current sheets on different resonance positions are coupled together.

  13. Rotating fiber array molecular driver and molecular momentum transfer device constructed therewith

    DOE Patents [OSTI]

    Milleron, Norman

    1983-01-01

    A rotating fiber array molecular driver is disclosed which includes a magnetically suspended and rotated central hub to which is attached a plurality of elongated fibers extending radially therefrom. The hub is rotated so as to straighten and axially extend the fibers and to provide the fibers with a tip speed which exceeds the average molecular velocity of fluid molecules entering between the fibers. Molecules colliding with the sides of the rotating fibers are accelerated to the tip speed of the fiber and given a momentum having a directional orientation within a relatively narrow distribution angle at a point radially outward of the hub, which is centered and peaks at the normal to the fiber sides in the direction of fiber rotation. The rotating fiber array may be used with other like fiber arrays or with other stationary structures to form molecular momentum transfer devices such as vacuum pumps, molecular separators, molecular coaters, or molecular reactors.

  14. Rotational fluctuation of molecules in quantum clusters. I. Path integral hybrid Monte Carlo algorithm

    SciTech Connect (OSTI)

    Miura, Shinichi [Institute for Molecular Science, 38 Myodaiji, Okazaki 444-8585 (Japan)

    2007-03-21

    In this paper, we present a path integral hybrid Monte Carlo (PIHMC) method for rotating molecules in quantum fluids. This is an extension of our PIHMC for correlated Bose fluids [S. Miura and J. Tanaka, J. Chem. Phys. 120, 2160 (2004)] to handle the molecular rotation quantum mechanically. A novel technique referred to be an effective potential of quantum rotation is introduced to incorporate the rotational degree of freedom in the path integral molecular dynamics or hybrid Monte Carlo algorithm. For a permutation move to satisfy Bose statistics, we devise a multilevel Metropolis method combined with a configurational-bias technique for efficiently sampling the permutation and the associated atomic coordinates. Then, we have applied the PIHMC to a helium-4 cluster doped with a carbonyl sulfide molecule. The effects of the quantum rotation on the solvation structure and energetics were examined. Translational and rotational fluctuations of the dopant in the superfluid cluster were also analyzed.

  15. Distant optical detection of small rotations and displacements by means of chiral liquid crystals

    SciTech Connect (OSTI)

    Shibaev, Petr V. E-mail: shibayev@fordham.edu; Troisi, Juliana; Reddy, Kathryn; Iljin, Andrey

    2014-01-15

    The paper describes novel chiral viscoelastic liquid crystalline mixtures and their application for the detection of small rotational displacements of two plates confining cholesteric liquid crystals (CLC). The mixtures are characterized by extremely high viscosities and stability of the selective reflection band (SRB) at ambient temperatures. Even a small rotation applied to the chiral liquid crystal (CLC) cell results in dramatic changes of the reflective properties of sandwiched CLC films. The angle and direction of rotation as well as the magnitude of CLC's shear deformation can be determined for a variety of experimental geometries, each of which is characterized by its own response function. The proposed model explains changes in the reflection spectra for different experimental geometries and relates them to the angle of rotation and magnitude of shear. The method was tested for a detection of small rotations from a distance of up to 50 m and allows for resolving small rotations of the order of fractions of degrees.

  16. Simulation of Alpha Particles in Rotating Plasma Interacting with a Stationary Ripple

    SciTech Connect (OSTI)

    Abraham J. Fetterman and Nathaniel J. Fisch

    2011-01-11

    Superthermal ExB rotation can provide magnetohydrodynamic (MHD) stability and enhanced confinement to axisymmetric mirrors. However, the rotation speed has been limited by phenomena at end electrodes. A new prediction is that rotation might instead be produced using a magnetic ripple and alpha particle kinetic energy, in an extension of the alpha channeling concept. The interaction of alpha particles with the ripple results in visually interesting and practically useful orbits.

  17. Double rotation NMR studies of zeolites and aluminophosphate molecular sieves

    SciTech Connect (OSTI)

    Jelinek, R. |

    1993-07-01

    Goal is to study the organization and structures of guest atoms and molecules and their reactions on internal surfaces within pores of zeolites and aluminophosphate molecular sieves. {sup 27}Al and {sup 23}Na double rotation NMR (DOR) is used since it removes the anisotropic broadening in NMR spectra of quadrupolar nuclei, thus increasing resolution. This work concentrates on probing aluminum framework atoms in aluminophosphate molecular sieves and sodium extra framework cations in porous aluminosilicates. In aluminophosphates, ordering and electronic environments of the framework {sup 27}Al nuclei are modified upon adsorption of water molecules within the channels; a relation is sought between the sieve channel topology and the organization of adsorbed water, as well as the interaction between the Al nuclei and the water molecules. Extra framework Na{sup +} cations are directly involved in adsorption processes and reactions in zeolite cavities.

  18. Damping, motional narrowing, and chaos in rotational nuclei

    SciTech Connect (OSTI)

    Stephens, F. S.; Deleplanque, M. A.; Lee, I. Y.; Macchiavelli, A. O.; Fallon, P.; Diamond, R. M.; Ward, D.; Clark, R. M.; Cromaz, M.

    2008-09-15

    We have studied the unresolved {gamma}-ray spectrum of three ytterbium nuclei produced in heavy-ion fusion reactions and measured the two damping widths, {gamma}{sub {mu}}, the spreading (compound-damping) width, and {gamma}{sub rot}, the rotational damping width, together with P{sub nar}, the probability that the population enters and leaves a given state via the same component of the wave function. Our results for {gamma}{sub {mu}} and {gamma}{sub rot} are in good agreement with theoretical expectations, as well as with those of other groups using different methods. Our results for P{sub nar} lead to a new method for quantitative evaluation of the full order-to-chaos transition in these Yb nuclei. Finally, we provide the first evidence for the motional narrowing of {gamma}{sub rot} in nuclei. The basic physics occurring in this region is level mixing, which our simulation technique reproduces surprisingly well.

  19. Rotating black hole thermodynamics with a particle probe

    SciTech Connect (OSTI)

    Gwak, Bogeun; Lee, Bum-Hoon

    2011-10-15

    The thermodynamics of Myers-Perry black holes in general dimensions are studied using a particle probe. When undergoing particle absorption, the changes of the entropy and irreducible mass are shown to be dependent on the particle radial momentum. The black hole thermodynamic behaviors are dependent on dimensionality for specific rotations. For a 4-dimensional Kerr black hole, its black hole properties are maintained for any particle absorption. 5-dimensional black holes can avoid a naked ring singularity by absorbing a particle in specific momenta ranges. Black holes over 6 dimensions become ultraspinning black holes through a specific form of particle absorption. The microscopical changes are interpreted in limited cases of Myers-Perry black holes using Kerr/CFT correspondence. We systematically describe the black hole properties changed by particle absorption in all dimensions.

  20. Muon Spin Rotation Spectroscopy - Utilizing Muons in Solid State Physics

    SciTech Connect (OSTI)

    Suter, Andreas

    2012-10-17

    Over the past decades muon spin rotation techniques (mSR) have established themselves as an invaluable tool to study a variety of static and dynamic phenomena in bulk solid state physics and chemistry. Common to all these approaches is that the muon is utilized as a spin microprobe and/or hydrogen-like probe, implanted in the material under investigation. Recent developments extend the range of application to near surface phenomena, thin film and super-lattice studies. After briefly summarizing the production of so called surface muons used for bulk studies, and discussing the principle differences between pulsed and continuous muon beams, the production of keV-energy muon sources will be discussed. A few topical examples from different active research fields will be presented to demonstrate the power of these techniques.

  1. Nanoparticles at liquid interfaces: Rotational dynamics and angular locking

    SciTech Connect (OSTI)

    Razavi, Sepideh; Kretzschmar, Ilona; Koplik, Joel; Colosqui, Carlos E.

    2014-01-07

    Nanoparticles with different surface morphologies that straddle the interface between two immiscible liquids are studied via molecular dynamics simulations. The methodology employed allows us to compute the interfacial free energy at different angular orientations of the nanoparticle. Due to their atomistic nature, the studied nanoparticles present both microscale and macroscale geometrical features and cannot be accurately modeled as a perfectly smooth body (e.g., spheres and cylinders). Under certain physical conditions, microscale features can produce free energy barriers that are much larger than the thermal energy of the surrounding media. The presence of these energy barriers can effectively lock the particle at specific angular orientations with respect to the liquid-liquid interface. This work provides new insights on the rotational dynamics of Brownian particles at liquid interfaces and suggests possible strategies to exploit the effects of microscale features with given geometric characteristics.

  2. Surface geometry of a rotating black hole in a magnetic field...

    Office of Scientific and Technical Information (OSTI)

    Subject: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BLACK HOLES; KERR FIELD; ROTATION; DIFFERENTIAL GEOMETRY; EINSTEIN-MAXWELL EQUATIONS; EQUATIONS; FIELD EQUATIONS; ...

  3. Spin rotators and split Siberian Snakes (Journal Article) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Spin rotators and split Siberian Snakes Citation Details In-Document ... DOE Contract Number: AC02-98CH10886 Resource Type: Journal Article Resource Relation: ...

  4. Time-Resolved Picosecond Pure-Rotational Coherent anti-Stokes...

    Office of Scientific and Technical Information (OSTI)

    Time-Resolved Picosecond Pure-Rotational Coherent anti-Stokes Raman Spectroscopy for Thermometry and Species Concentration in Combustion Environments. Citation Details In-Document ...

  5. MHK Projects/Contra Rotating Marine Turbine CoRMaT | Open Energy...

    Open Energy Info (EERE)

    Contra Rotating Marine Turbine CoRMaT < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps...

  6. Effect on plasma rotation of lower hybrid (LH) waves in Alcator...

    Office of Scientific and Technical Information (OSTI)

    the plasma current is low, which may explain the rotation reversal for low plasma current. ... L. 1 + Show Author Affiliations Plasma Science and Fusion Center, MIT, Cambridge, MA ...

  7. Webinar: Testing Oxygen Reduction Reaction Activity with the Rotating Disc Electrode Technique

    Broader source: Energy.gov [DOE]

    Video recording of the Fuel Cell Technologies Office webinar, Testing Oxygen Reduction Reaction Activity with the Rotating Disc Electrode Technique, originally presented on March 12, 2013.

  8. Rotation magnet sputtering: Damage-free novel magnetron sputtering using rotating helical magnet with very high target utilization

    SciTech Connect (OSTI)

    Goto, Tetsuya; Matsuoka, Takaaki; Ohmi, Tadahiro

    2009-07-15

    Novel magnetron-sputtering equipment, called rotation magnet sputtering (ROT-MS), was developed to overcome various disadvantages of current magnetron-sputtering equipment. Disadvantages include (1) very low target utilization of less than 20%, (2) difficulty in obtaining uniform deposition on the substrate, and (3) charge-up damages and ion-bombardment-induced damages resulting from very high electron temperature (>3 eV) and that the substrate is set at the plasma excitation region. In ROT-MS, a number of moving high-density plasma loops are excited on the target surface by rotating helical magnets, resulting in very high target utilization with uniform target erosion and uniform deposition on the substrate. This excellent performance can be principally maintained even if equipment size increases for very large-substrate deposition. Because strong horizontal magnetic fields (>0.05 T) are produced within a very limited region just at the target surface, very low electron-temperature plasmas (<2.5 eV for Ar plasma and <1 eV for direct-current-excited Xe plasma) are excited at the very limited region adjacent to the target surface with a combination of grounded plate closely mounted on the strong magnetic field region. Consequently, the authors can establish charge-up damage-free and ion-bombardment-induced damage-free processes. ROT-MS has been applied for thin-film formation of LaB{sub 6}, which is well known as a stable, low-work-function bulk-crystal material for electron emissions. The work function of the LaB{sub 6} film decreased to 2.8 eV due to enhanced (100)-orientation crystallinity and reduced resistivity realized by adjusting the flux of low-energy bombarding ions impinging on the depositing surface, which work very efficiently, improving the performance of the electron emission devices.

  9. Magnetic island and plasma rotation under external resonant magnetic perturbation in the T-10 tokamak

    SciTech Connect (OSTI)

    Eliseev, L. G.; Ivanov, N. V. Kakurin, A. M.; Perfilov, S. V.; Melnikov, A. V.

    2015-05-15

    Experimental comparison of the m = 2, n = 1 mode and plasma rotation velocities at q = 2 magnetic surface in a wide range of the mode amplitudes is presented. Phase velocity of the mode rotation is measured with a set of poloidal magnetic field sensors located at the inner side of the vacuum vessel wall. Plasma rotation velocity at the q = 2 magnetic surface in the direction of the mode phase velocity is measured with the heavy ion beam probe diagnostics. In the presence of a static Resonant Magnetic Perturbation (RMP), the rotation is irregular that appears as cyclical variations of the mode and plasma instantaneous velocities. The period of these variations is equal to the period of the mode oscillations. In the case of high mode amplitude, the rotation irregularity of the mode is consistent with the rotation irregularity of the resonant plasma layer. On the contrary, the observed rise of the mode rotation irregularity in the case of low mode amplitude occurs without an increase of the rotation irregularity of the resonant plasma layer. The experimental results are simulated and analyzed with the TEAR code based on the two-fluid MHD approximation. Calculated irregularities of the mode and plasma rotation depend on the mode amplitude similar to the experimental data. For large islands, the rotation irregularity is attributed to oscillations of the electromagnetic torque applied to the resonant plasma layer. For small islands, the deviation of the mode rotation velocity from the plasma velocity occurs due to the effect of finite plasma resistivity.

  10. SUNSPOT ROTATION, SIGMOIDAL FILAMENT, FLARE, AND CORONAL MASS EJECTION: THE EVENT ON 2000 FEBRUARY 10

    SciTech Connect (OSTI)

    Yan, X. L.; Qu, Z. Q.; Kong, D. F.

    2012-07-20

    We find that a sunspot with positive polarity had an obvious counterclockwise rotation and resulted in the formation and eruption of an inverse S-shaped filament in NOAA Active Region 08858 from 2000 February 9 to 10. The sunspot had two umbrae which rotated around each other by 195 Degree-Sign within about 24 hr. The average rotation rate was nearly 8 Degree-Sign hr{sup -1}. The fastest rotation in the photosphere took place during 14:00 UT to 22:01 UT on February 9, with a rotation rate of nearly 16 Degree-Sign hr{sup -1}. The fastest rotation in the chromosphere and the corona took place during 15:28 UT to 19:00 UT on February 9, with a rotation rate of nearly 20 Degree-Sign hr{sup -1}. Interestingly, the rapid increase of the positive magnetic flux occurred only during the fastest rotation of the rotating sunspot, the bright loop-shaped structure, and the filament. During the sunspot rotation, the inverse S-shaped filament gradually formed in the EUV filament channel. The filament experienced two eruptions. In the first eruption, the filament rose quickly and then the filament loops carrying the cool and the hot material were seen to spiral counterclockwise into the sunspot. About 10 minutes later, the filament became active and finally erupted. The filament eruption was accompanied with a C-class flare and a halo coronal mass ejection. These results provide evidence that sunspot rotation plays an important role in the formation and eruption of the sigmoidal active-region filament.

  11. The impact of gas bulk rotation on the Lyα line

    SciTech Connect (OSTI)

    Garavito-Camargo, Juan N.; Forero-Romero, Jaime E.; Dijkstra, Mark E-mail: je.forero@uniandes.edu.co

    2014-11-10

    We present results of radiative transfer calculations to measure the impact of gas bulk rotation on the morphology of the Lyα emission line in distant galaxies. We model a galaxy as a sphere with an homogeneous mixture of dust and hydrogen at a constant temperature. These spheres undergo solid-body rotation with maximum velocities in the range 0-300 km s{sup –1} and neutral hydrogen optical depths in the range τ{sub H} = 10{sup 5}-10{sup 7}. We consider two types of source distributions in the sphere: central and homogeneous. Our main result is that rotation introduces a dependence of the line morphology with viewing angle and rotational velocity. Observations with a line of sight parallel to the rotation axis yield line morphologies similar to the static case. For lines of sight perpendicular to the rotation axis, both the intensity at the line center and the line width increase with rotational velocity. Along the same line of sight, the line becomes single peaked at rotational velocities close to half the line width in the static case. Notably, we find that rotation does not induce any spatial anisotropy in the integrated line flux, the escape fraction or the average number of scatterings. This is because Lyman scattering through a rotating solid-body proceeds identically to the static case. The only difference is the Doppler shift from the different regions in the sphere that move with respect to the observer. This allows us to derive an analytic approximation for the viewing-angle dependence of the emerging spectrum, as a function of rotational velocity.

  12. Hawking radiation of scalar particles from accelerating and rotating black holes

    SciTech Connect (OSTI)

    Gillani, Usman A.; Rehman, Mudassar; Saifullah, K. E-mail: mudassar051@yahoo.com

    2011-06-01

    Hawking radiation of uncharged and charged scalar particles from accelerating and rotating black holes is studied. We calculate the tunneling probabilities of these particles from the rotation and acceleration horizons of these black holes. Using this method we recover the correct Hawking temperature as well.

  13. Rotation Angle for the Optimum Tracking of One-Axis Trackers

    SciTech Connect (OSTI)

    Marion, W. F.; Dobos, A. P.

    2013-07-01

    An equation for the rotation angle for optimum tracking of one-axis trackers is derived along with equations giving the relationships between the rotation angle and the surface tilt and azimuth angles. These equations are useful for improved modeling of the solar radiation available to a collector with tracking constraints and for determining the appropriate motor revolutions for optimum tracking.

  14. The effect of diamagnetic flows on turbulent driven ion toroidal rotation

    SciTech Connect (OSTI)

    Lee, J. P.; Barnes, M.; Parra, F. I.; Belli, E. A.; Candy, J.

    2014-05-15

    Turbulent momentum redistribution determines the radial profile of rotation in a tokamak. The momentum transport driven by diamagnetic flow effects is an important piece of the radial momentum transport for sub-sonic rotation, which is often observed in experiments. In a non-rotating state, the diamagnetic flow and the E B flow must cancel. The diamagnetic flow and the E B flow have different effects on the turbulent momentum flux, and this difference in behavior induces intrinsic rotation. The momentum flux is evaluated using gyrokinetic equations that are corrected to higher order in the ratio of the poloidal Larmor radius to the minor radius, which requires evaluation of the diamagnetic corrections to Maxwellian equilibria. To study the momentum transport due to diamagnetic flow effects, three experimental observations of ion rotation are examined. First, a strong pressure gradient at the plasma edge is shown to result in a significant inward momentum transport due to the diamagnetic effect, which may explain the observed peaking of rotation in a high confinement mode. Second, the direction of momentum transport is shown to change as collisionality increases, which is qualitatively consistent with the observed reversal of intrinsic rotation by varying plasma density and current. Last, the dependence of the intrinsic momentum flux on the magnetic shear is found, and it may explain the observed rotation changes in the presence of lower hybrid current drive.

  15. Single-ended counter-rotating radial turbine for space application

    DOE Patents [OSTI]

    Coomes, E.P.; Wilson, D.G.; Webb, B.J.; McCabe, S.J.

    1987-05-13

    A single-ended turbine with counter-rotating blades operating with sodium as the working fluid. The single-ended, counter-rotating feature of the turbine results in zero torque application to a space platform. Thus, maneuvering of the platform is not adversely affected by the turbine. 4 figs.

  16. Rotating dipole and quadrupole field for a multiple cathode system

    SciTech Connect (OSTI)

    Chang, X.; Ben-Zvi, I.; Kewisch, J.; Litvinenko, V.; Meng, W.; Pikin, A.; Ptitsyn, V.; Rao, T.; Sheehy, B.; Skarita, J.; Wang, E.; Wu, Q.; Xin, T.

    2011-03-28

    A multiple cathode system has been designed to provide the high average current polarized electron bunches for the future electron-ion collider eRHIC [1]. One of the key research topics in this design is the technique to generate a combined dipole and quadrupole rotating field at high frequency (700 kHz). This type of field is necessary for combining bunches from different cathodes to the same axis with minimum emittance growth. Our simulations and the prototype test results to achieve this will be presented. The future eRHIC project, next upgrade of EHIC, will be the first electron-heavy ion collider in the world. For polarized-electron and polarized proton collisions, it requires a polarized electron source with high average current ({approx}50 mA), short bunch ({approx}3 mm), emittance of about 20 {micro}m and energy spread of {approx}1% at 10 MeV. The state-of-art polarized electron cathode can generate average current of about more than 1 mA, but much less than 50 mA. The current is limited by the quantum efficiency, lifetime, space charge and ultra-high vacuum requirement of the polarized cathode. A possible approach to achieve the 50 mA beam is to employ multiple cathodes, such as 20 cathodes, and combine the multiple bunched beams from cathodes to the same axis. We name it as 'Gatling gun' because its operations bear similarity to a multi-barrel Gatling gun. The electron spin direction is not affected by electric field but will follow to the direction of the magnetic bending. This requires that, to preserve the spin polarization from cathode, the fixed bending field after the solenoid and the rotating bending field in combiner must be either a pair of electric bendings or a pair of magnetic bendings. We choose the scheme with a pair of magnetic bendings because it is much easier than the scheme with a pair of electric bendings at our 200 keV electron energy level.

  17. Direct numerical simulation of turbulent flow in a rotating square duct

    SciTech Connect (OSTI)

    Dai, Yi-Jun; Huang, Wei-Xi Xu, Chun-Xiao; Cui, Gui-Xiang

    2015-06-15

    A fully developed turbulent flow in a rotating straight square duct is simulated by direct numerical simulations at Re{sub ?} = 300 and 0 ? Ro{sub ?} ? 40. The rotating axis is parallel to two opposite walls of the duct and normal to the main flow. Variations of the turbulence statistics with the rotation rate are presented, and a comparison with the rotating turbulent channel flow is discussed. Rich secondary flow patterns in the cross section are observed by varying the rotation rate. The appearance of a pair of additional vortices above the pressure wall is carefully examined, and the underlying mechanism is explained according to the budget analysis of the mean momentum equations.

  18. Controlling octahedral rotations in a perovskite via strain doping

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Herklotz, Andreas; Biegalski, Michael D.; Lee, Ho Nyung; Ward, Thomas Zac; Wong, A. T.; Meyer, T.

    2016-05-24

    The perovskite unit cell is the fundamental building block of many functional materials. The manipulation of this crystal structure is known to be of central importance to controlling many technologically promising phenomena related to superconductivity, multiferroicity, mangetoresistivity, and photovoltaics. The broad range of properties that this structure can exhibit is in part due to the centrally coordinated octahedra bond flexibility, which allows for a multitude of distortions from the ideal highly symmetric structure. However, continuous and fine manipulation of these distortions has never been possible. Here, we show that controlled insertion of He atoms into an epitaxial perovskite film canmore » be used to finely tune the lattice symmetry by modifying the local distortions, i.e., octahedral bonding angle and length. Orthorhombic SrRuO3 films coherently grown on SrTiO3 substrates are used as a model system. Implanted He atoms are confirmed to induce out-of-plane strain, which provides the ability to controllably shift the bulk-like orthorhombically distorted phase to a tetragonal structure by shifting the oxygen octahedra rotation pattern. Lastly, these results demonstrate that He implantation offers an entirely new pathway to strain engineering of perovskite-based complex oxide thin films, useful for creating new functionalities or properties in perovskite materials.« less

  19. SIMULATED FARADAY ROTATION MEASURES TOWARD HIGH GALACTIC LATITUDES

    SciTech Connect (OSTI)

    Akahori, Takuya; Kim, Jongsoo; Ryu, Dongsu; Gaensler, B. M. E-mail: akahori@physics.usyd.edu.au E-mail: ryu@canopus.cnu.ac.kr

    2013-04-20

    We study the Faraday rotation measure (RM) due to the Galactic magnetic field (GMF) toward high Galactic latitudes. The RM arises from the global, regular component as well as from the turbulent, random component of the GMF. We model the former based on observations and the latter using the data of magnetohydrodynamic turbulence simulations. For a large number of different GMF models, we produce mock RM maps around the Galactic poles and calculate various statistical quantities with the RM maps. We find that the observed medians of RMs toward the north and south Galactic poles, {approx}0.0 {+-} 0.5 rad m{sup -2} and {approx} + 6.3 {+-} 0.5 rad m{sup -2}, are difficult to explain with any of our many alternate GMF models. The standard deviation of observed RMs, {approx}9 rad m{sup -2}, is clearly larger than that of simulated RMs. The second-order structure function of observed RMs is substantially larger than that of simulated RMs, especially at small angular scales. We discuss other possible contributions to RM toward high Galactic latitudes. Besides observational errors and the intrinsic RM of background radio sources against which RM is observed, we suggest that the RM due to the intergalactic magnetic field may account for a substantial fraction of the observed RM. Finally, we note that reproducing the observed medians may require additional components or/and structures of the GMF that are not present in our models.

  20. Deformations and magnetic rotations in the {sup 60}Ni nucleus

    SciTech Connect (OSTI)

    Torres, D. A.; Cristancho, F.; Andersson, L.-L.; Johansson, E. K.; Rudolph, D.; Fahlander, C.; Ekman, J.; Rietz, R. du; Andreoiu, C.; Carpenter, M. P.; Seweryniak, D.; Zhu, S.; Charity, R. J.; Chiara, C. J.; Hoel, C.; Pechenaya, O. L.; Reviol, W.; Sarantites, D. G.; Sobotka, L. G.; Baktash, C.

    2008-11-15

    Data from three experiments using the heavy-ion fusion evaporation-reaction {sup 36}Ar+{sup 28}Si have been combined to study high-spin states in the residual nucleus {sup 60}Ni, which is populated via the evaporation of four protons from the compound nucleus {sup 64}Ge. The GAMMASPHERE array was used for all the experiments in conjunction with a 4{pi} charged-particle detector arrays (MICROBALL, LUWUSIA) and neutron detectors (NEUTRON SHELL) to allow for the detection of {gamma} rays in coincidence with the evaporated particles. An extended {sup 60}Ni level scheme is presented, comprising more than 270{gamma}-ray transitions and 110 excited states. Their spins and parities have been assigned via directional correlations of {gamma} rays emitted from oriented states. Spherical shell-model calculations in the fp-shell characterize some of the low-spin states, while the experimental results of the rotational bands are analyzed with configuration-dependent cranked Nilsson-Strutinsky calculations.

  1. Gravitational radiation from rotating monopole-string systems

    SciTech Connect (OSTI)

    Babichev, E.; Dokuchaev, V.; Kachelriess, M.

    2005-02-15

    We study the gravitational radiation from a rotating monopole-antimonopole pair connected by a string. While at not too high frequencies the emitted gravitational spectrum is described asymptotically by P{sub n}{proportional_to}n{sup -1}, the spectrum is exponentially suppressed in the high-frequency limit, P{sub n}{proportional_to}exp(-n/n{sub cr}). Below n{sub cr}, the emitted spectrum of gravitational waves is very similar to the case of an oscillating monopole pair connected by a string, and we argue, therefore, that the spectrum found holds approximately for any moving monopole-string system. As an application, we discuss the stochastic gravitational wave background generated by monopole-antimonopole pairs connected by strings in the early Universe and gravitational wave bursts emitted at present by monopole-string networks. We confirm that advanced gravitational wave detectors have the potential to detect a signal for string tensions as small as G{mu}{approx}10{sup -13}.

  2. Semi-Implicit Reversible Algorithms for Rigid Body Rotational Dynamics

    SciTech Connect (OSTI)

    Nukala, Phani K; Shelton Jr, William Allison

    2006-09-01

    This paper presents two semi-implicit algorithms based on splitting methodology for rigid body rotational dynamics. The first algorithm is a variation of partitioned Runge-Kutta (PRK) methodology that can be formulated as a splitting method. The second algorithm is akin to a multiple time stepping scheme and is based on modified Crouch-Grossman (MCG) methodology, which can also be expressed as a splitting algorithm. These algorithms are second-order accurate and time-reversible; however, they are not Poisson integrators, i.e., non-symplectic. These algorithms conserve some of the first integrals of motion, but some others are not conserved; however, the fluctuations in these invariants are bounded over exponentially long time intervals. These algorithms exhibit excellent long-term behavior because of their reversibility property and their (approximate) Poisson structure preserving property. The numerical results indicate that the proposed algorithms exhibit superior performance compared to some of the currently well known algorithms such as the Simo-Wong algorithm, Newmark algorithm, discrete Moser-Veselov algorithm, Lewis-Simo algorithm, and the LIEMID[EA] algorithm.

  3. Innovative Sensors for Pipeline Crawlers: Rotating Permanent Magnet Inspection

    SciTech Connect (OSTI)

    J. Bruce Nestleroth; Richard J. Davis; Stephanie Flamberg

    2006-09-30

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they may encounter. To facilitate inspection of these ''unpiggable'' pipelines, recent inspection development efforts have focused on a new generation of powered inspection platforms that are able to crawl slowly inside a pipeline and can maneuver past the physical barriers that limit internal inspection applicability, such as bore restrictions, low product flow rate, and low pressure. The first step in this research was to review existing inspection technologies for applicability and compatibility with crawler systems. Most existing inspection technologies, including magnetic flux leakage and ultrasonic methods, had significant implementation limitations including mass, physical size, inspection energy coupling requirements and technology maturity. The remote field technique was the most promising but power consumption was high and anomaly signals were low requiring sensitive detectors and electronics. After reviewing each inspection technology, it was decided to investigate the potential for a new inspection method. The new inspection method takes advantage of advances in permanent magnet strength, along with their wide availability and low cost. Called rotating permanent magnet inspection (RPMI), this patent pending technology employs pairs of permanent magnets rotating around the central axis of a cylinder to induce high current densities in the material under inspection. Anomalies and wall thickness variations are detected with an array of sensors that measure local changes in the magnetic field produced by the induced current flowing in the material. This inspection method is an alternative to the common concentric coil remote field technique that induces low-frequency eddy

  4. Digestion of waste activated sludge by anaerobic rotating biological contactors

    SciTech Connect (OSTI)

    Lee, Chiyuan.

    1990-01-01

    Two parallel, four-stage anaerobic rotating biological contactors (RBC) were continuously operated to evaluate the engineering feasibility of such an attached growth system for digesting sewage sludge. Waste activated sludge was used as the feed which contained 10,000 mg/l of suspended solids and an average total COD of 11,890 mg/l. The effects of three different hydraulic retention times (HRTs: 10, 5, 2.5 days) and three different operating temperatures (35, 30, 25 C) on the digester performance were evaluated. In addition, the maximum methanogenic capability of the RBC system in utilizing acetic, propionic and butyric acids was also assessed. Results indicated that the performance of the anaerobic RBS digester was strongly affected by both the HRT and the operating temperature. A decrease of either HRT or operating temperature would result in a lower stabilization efficiency. At 35 C the digester could stabilize 39.3% of the total sludge COD with a 5-day HRT, and this efficiency was very close to the minimum requirement of 40% in the general engineering practice. The accelerated digestion rate in an RBC system was mainly due to the high methanogenic capability existing in the attached-growths, which also avoid biological washout at a short hydraulic retention condition. Applications of the experimental data to an actual engineering design were also illustrated.

  5. BONA FIDE, STRONG-VARIABLE GALACTIC LUMINOUS BLUE VARIABLE STARS ARE FAST ROTATORS: DETECTION OF A HIGH ROTATIONAL VELOCITY IN HR CARINAE

    SciTech Connect (OSTI)

    Groh, J. H.; Damineli, A.; Moises, A. P.; Teodoro, M.; Hillier, D. J.; Barba, R.; Fernandez-Lajus, E.; Gamen, R. C.; Solivella, G.

    2009-11-01

    We report optical observations of the luminous blue variable (LBV) HR Carinae which show that the star has reached a visual minimum phase in 2009. More importantly, we detected absorptions due to Si IV lambdalambda4088-4116. To match their observed line profiles from 2009 May, a high rotational velocity of v{sub rot} approx = 150 +- 20 km s{sup -1} is needed (assuming an inclination angle of 30 deg.), implying that HR Car rotates at approx =0.88 +- 0.2 of its critical velocity for breakup (v{sub crit}). Our results suggest that fast rotation is typical in all strong-variable, bona fide galactic LBVs, which present S-Dor-type variability. Strong-variable LBVs are located in a well-defined region of the HR diagram during visual minimum (the 'LBV minimum instability strip'). We suggest this region corresponds to where v{sub crit} is reached. To the left of this strip, a forbidden zone with v{sub rot}/v{sub crit}>1 is present, explaining why no LBVs are detected in this zone. Since dormant/ex LBVs like P Cygni and HD 168625 have low v{sub rot}, we propose that LBVs can be separated into two groups: fast-rotating, strong-variable stars showing S-Dor cycles (such as AG Car and HR Car) and slow-rotating stars with much less variability (such as P Cygni and HD 168625). We speculate that supernova (SN) progenitors which had S-Dor cycles before exploding (such as in SN 2001ig, SN 2003bg, and SN 2005gj) could have been fast rotators. We suggest that the potential difficulty of fast-rotating Galactic LBVs to lose angular momentum is additional evidence that such stars could explode during the LBV phase.

  6. Verification of theoretically computed spectra for a point rotating in a vertical plane

    SciTech Connect (OSTI)

    Powell, D.C.; Connell, J.R.; George, R.L.

    1985-03-01

    A theoretical model is modified and tested that produces the power spectrum of the alongwind component of turbulence as experienced by a point rotating in a vertical plane perpendicular to the mean wind direction. The ability to generate such a power spectrum, independent of measurement, is important in wind turbine design and testing. The radius of the circle of rotation, its height above the ground, and the rate of rotation are typical for those for a MOD-OA wind turbine. Verification of this model is attempted by comparing two sets of variances that correspond to individual harmonic bands of spectra of turbulence in the rotational frame. One set of variances is calculated by integrating the theoretically generated rotational spectra; the other is calculated by integrating rotational spectra from real data analysis. The theoretical spectrum is generated by Fourier transformation of an autocorrelation function taken from von Karman and modified for the rotational frame. The autocorrelation is based on dimensionless parameters, each of which incorporates both atmospheric and wind turbine parameters. The real data time series are formed by sampling around the circle of anemometers of the Vertical Plane Array at the former MOD-OA site at Clayton, New Mexico.

  7. Gravitational wave extraction in simulations of rotating stellar core collapse

    SciTech Connect (OSTI)

    Reisswig, C.; Ott, C. D.; Sperhake, U.; Schnetter, E.

    2011-03-15

    We perform simulations of general relativistic rotating stellar core collapse and compute the gravitational waves (GWs) emitted in the core-bounce phase of three representative models via multiple techniques. The simplest technique, the quadrupole formula (QF), estimates the GW content in the spacetime from the mass-quadrupole tensor only. It is strictly valid only in the weak-field and slow-motion approximation. For the first time, we apply GW extraction methods in core collapse that are fully curvature based and valid for strongly radiating and highly relativistic sources. These techniques are not restricted to weak-field and slow-motion assumptions. We employ three extraction methods computing (i) the Newman-Penrose (NP) scalar {Psi}{sub 4}, (ii) Regge-Wheeler-Zerilli-Moncrief master functions, and (iii) Cauchy-characteristic extraction (CCE) allowing for the extraction of GWs at future null infinity, where the spacetime is asymptotically flat and the GW content is unambiguously defined. The latter technique is the only one not suffering from residual gauge and finite-radius effects. All curvature-based methods suffer from strong nonlinear drifts. We employ the fixed-frequency integration technique as a high-pass waveform filter. Using the CCE results as a benchmark, we find that finite-radius NP extraction yields results that agree nearly perfectly in phase, but differ in amplitude by {approx}1%-7% at core bounce, depending on the model. Regge-Wheeler-Zerilli-Moncrief waveforms, while, in general, agreeing in phase, contain spurious high-frequency noise of comparable amplitudes to those of the relatively weak GWs emitted in core collapse. We also find remarkably good agreement of the waveforms obtained from the QF with those obtained from CCE. The results from QF agree very well in phase and systematically underpredict peak amplitudes by {approx}5%-11%, which is comparable to the NP results and is certainly within the uncertainties associated with core collapse

  8. A dynamo model of magnetic activity in solar-like stars with different rotational velocities

    SciTech Connect (OSTI)

    Karak, Bidya Binay; Choudhuri, Arnab Rai; Kitchatinov, Leonid L.

    2014-08-10

    We attempt to provide a quantitative theoretical explanation for the observations that Ca II H/K emission and X-ray emission from solar-like stars increase with decreasing Rossby number (i.e., with faster rotation). Assuming that these emissions are caused by magnetic cycles similar to the sunspot cycle, we construct flux transport dynamo models of 1 M{sub ☉} stars rotating with different rotation periods. We first compute the differential rotation and the meridional circulation inside these stars from a mean-field hydrodynamics model. Then these are substituted in our dynamo code to produce periodic solutions. We find that the dimensionless amplitude f{sub m} of the toroidal flux through the star increases with decreasing rotation period. The observational data can be matched if we assume the emissions to go as the power 3-4 of f{sub m}. Assuming that the Babcock-Leighton mechanism saturates with increasing rotation, we can provide an explanation for the observed saturation of emission at low Rossby numbers. The main failure of our model is that it predicts an increase of the magnetic cycle period with increasing rotation rate, which is the opposite of what is found observationally. Much of our calculations are based on the assumption that the magnetic buoyancy makes the magnetic flux tubes rise radially from the bottom of the convection zone. Taking into account the fact that the Coriolis force diverts the magnetic flux tubes to rise parallel to the rotation axis in rapidly rotating stars, the results do not change qualitatively.

  9. Rotational fluxons of Bose-Einstein condensates in coplanar double-ring traps

    SciTech Connect (OSTI)

    Brand, J.; Haigh, T. J.; Zuelicke, U.

    2009-07-15

    Rotational analogs to magnetic fluxons in conventional Josephson junctions are predicted to emerge in the ground state of rotating tunnel-coupled annular Bose-Einstein condensates (BECs). Such topological condensate-phase structures can be manipulated by external potentials. We determine conditions for observing macroscopic quantum tunneling of a fluxon. Rotational fluxons in double-ring BECs can be created, manipulated, and controlled by external potentials in different ways than is possible in the solid-state system, thus rendering them a promising candidate system for studying and utilizing quantum properties of collective many-particle degrees of freedom.

  10. An elementary singularity-free Rotational Brownian Dynamics algorithm for anisotropic particles

    SciTech Connect (OSTI)

    Ilie, Ioana M.; Briels, Wim J.; Otter, Wouter K. den

    2015-03-21

    Brownian Dynamics is the designated technique to simulate the collective dynamics of colloidal particles suspended in a solution, e.g., the self-assembly of patchy particles. Simulating the rotational dynamics of anisotropic particles by a first-order Langevin equation, however, gives rise to a number of complications, ranging from singularities when using a set of three rotational coordinates to subtle metric and drift corrections. Here, we derive and numerically validate a quaternion-based Rotational Brownian Dynamics algorithm that handles these complications in a simple and elegant way. The extension to hydrodynamic interactions is also discussed.

  11. ARM - Field Campaign - Verification of the Origins of Rotation in Tornadoes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Experiment (VORTEX) govCampaignsVerification of the Origins of Rotation in Tornadoes Experiment (VORTEX) ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX) 1995.04.01 - 1995.05.31 Lead Scientist : Ed Westwater For data sets, see below. Abstract Joint Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX) -ARM

  12. General Nonextremal Rotating Black Holes in Minimal Five-Dimensional Gauged Supergravity

    SciTech Connect (OSTI)

    Chong, Z.-W.; Lue, H.; Pope, C.N.; Cvetic, M.

    2005-10-14

    We construct the general solution for nonextremal charged rotating black holes in five-dimensional minimal gauged supergravity. They are characterized by four nontrivial parameters: namely, the mass, the charge, and the two independent rotation parameters. The metrics in general describe regular rotating black holes, providing the parameters lie in appropriate ranges so that naked singularities and closed timelike curves (CTCs) are avoided. We calculate the conserved energy, angular momenta, and charge for the solutions, and show how supersymmetric solutions arise in a Bogomol'nyi-Prasad-Sommerfield limit. These have naked CTCs in general, but for special choices of the parameters we obtain new regular supersymmetric black holes or smooth topological solitons.

  13. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Optical Depths and Liquid Water Paths at the NSA CART J. C. Doran, J. C. Barnard, and S. Zhong Pacific Northwest National Laboratory Richland, Washington C. J. Jakob European Centre for Medium-Range Weather Forecasts Reading, England Introduction As part of our efforts to characterize the cloud properties at the North Slope of Alaska (NSA) Cloud and Radiation Testbed (CART), we have used microwave radiometers (MWRs) and multi-filter rotating shadowband radiometers (MFRSRs) at Barrow (a coastal

  14. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dust Properties Derived from Multi-Filter Rotating Shadowband Radiometer Data in Niamey E. Kassianov, T. Ackerman, J. Barnard, C. Flynn, and S. McFarlane Pacific Northwest National Laboratory Richland, Washington Introduction One of the key uncertainties in the earth's radiation balance is the effect of dust on radiative fluxes (aerosol radiative forcing), which in turn affects climatic processes on both planetary and local scales (e.g., Intergovernmental Panel on Climate Change 2001; Sokolik et

  15. Apparatus and method for forming a workpiece surface into a non-rotationally symmetric shape

    DOE Patents [OSTI]

    Dow, Thomas A.; Garrard, Kenneth P.; Moorefield, II, George M.; Taylor, Lauren W.

    1995-11-21

    A turning machine includes a controller for generating both aspherical and non-symmetrical shape components defining the predetermined shape, and a controller for controlling a spindle and a positionable cutting blade to thereby form a predetermined non-rotationally symmetric shape in a workpiece surface. The apparatus includes a rotatable spindle for rotatably mounting the workpiece about an axis, a spindle encoder for sensing an angular position of the rotating workpiece, the cutting blade, and radial and transverse positioners for relatively positioning the cutting blade and workpiece along respective radial and transverse directions. The controller cooperates with a fast transverse positioner for positioning the cutting blade in predetermined varying transverse positions during a revolution of the workpiece.

  16. Calculation of rotationally inelastic processes in electron collisions with CO{sub 2} molecules

    SciTech Connect (OSTI)

    Gianturco, F.A.; Stoeckling, T.

    1997-03-01

    The rotational excitation of the title linear polyatomic target, treated as a rigid rotor is computed using a fully {ital ab initio} interaction potential recently employed to obtain integral elastic cross sections [Gianturco and Stoecklin, J. Phys. B {bold 29}, 3933 (1996)] and to unravel several resonances in the low-energy region. The present study looks at the rotationally inelastic processes which can occur in the energy range across the long-lived shape resonance at 3.9 eV and finds that the resonant process strongly enhances the overall efficiency of the rotational excitation by the electron projectile, as shown by the computed values of the average rotational energy transfers. Angular distributions are also evaluated at different collision energies and compared with earlier calculations. {copyright} {ital 1997} {ital The American Physical Society}

  17. MAGNETIC BRAKING FORMULATION FOR SUN-LIKE STARS: DEPENDENCE ON DIPOLE FIELD STRENGTH AND ROTATION RATE

    SciTech Connect (OSTI)

    Matt, Sean P.; Pinsonneault, Marc H.; Greene, Thomas P. E-mail: kmac@ucar.edu E-mail: thomas.p.greene@nasa.gov

    2012-08-01

    We use two-dimensional axisymmetric magnetohydrodynamic simulations to compute steady-state solutions for solar-like stellar winds from rotating stars with dipolar magnetic fields. Our parameter study includes 50 simulations covering a wide range of relative magnetic field strengths and rotation rates, extending from the slow- and approaching the fast-magnetic-rotator regimes. Using the simulations to compute the angular momentum loss, we derive a semi-analytic formulation for the external torque on the star that fits all of the simulations to a precision of a few percent. This formula provides a simple method for computing the magnetic braking of Sun-like stars due to magnetized stellar winds, which properly includes the dependence on the strength of the magnetic field, mass loss rate, stellar radius, surface gravity, and spin rate, and which is valid for both slow and fast rotators.

  18. Simultaneous π/2 rotation of two spin species of different gyromagnetic ratios

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chu, Ping -Han; Peng, Jen -Chieh

    2015-06-05

    Here, we examine the characteristics of the π/2 pulse for simultaneously rotating two spin species of different gyromagnetic ratios with the same sign. For a π/2 pulse using a rotating magnetic field, we derive an equation relating the frequency and strength of the pulse to the gyromagnetic ratios of the two particles and the strength of the constant holding field. For a π/2 pulse using a linear oscillatory magnetic field, we obtain the solutions numerically, and compare them with the solutions for the rotating π/2 pulse. Application of this analysis to the specific case of rotating neutrons and 3He atomsmore » simultaneously with a π/2 pulse, proposed for a neutron electric dipole moment experiment, is also presented.« less

  19. Consider Steam Turbine Drives for Rotating Equipment - Steam Tip Sheet #21

    SciTech Connect (OSTI)

    2012-01-01

    This revised AMO tip sheet on steam turbine drives for rotating equipment provides how-to advice for improving the system using low-cost, proven practices and technologies.

  20. Measurement of core plasma temperature and rotation on W7-X made...

    Office of Scientific and Technical Information (OSTI)

    Conference: Measurement of core plasma temperature and rotation on W7-X made available by the x-ray imaging crystal spectrometer (XICS) Citation Details In-Document Search Title: ...

  1. Principles and biophysical applications of single particle super-localization and rotational tracking

    SciTech Connect (OSTI)

    Gu, Yan

    2013-01-01

    While conventional Single Particle Tracking (SPT) techniques acquire 2D or 3D trajectories of particle probes, we have developed Single Particle Orientation and Rotational Tracking (SPORT) techniques to extract orientation and rotational information. Combined with DIC microscopy, the SPORT technique has been applied in biophysical studies, including membrane diffusion and intracellular transport. The rotational dynamics of nanoparticle vectors on live cell membranes was recorded and its influence on the fate of these nanoparticle vectors was elucidated. The rotational motions of gold nanorods with various surface modifiers were tracked continuously at a temporal resolution of 5 ms under a DIC microscope. We found that the rotational behaviors of gold nanorod vectors are strongly related to their surface charge, specific surface functional groups, and the availability of receptors on cell membranes. The study of rotational Brownian motion of nanoparticles on cell membranes will lead to a better understanding of the mechanisms of drug delivery and provide guidance in designing surface modification strategies for drug delivery vectors under various circumstances. To characterize the rotation mode of surface functionalized gold nanorods on cell membranes, the SPORT technique is combined with the correlation analysis of the bright and dark DIC intensities. The unique capabilities of visualizing and understanding rotational motions of functionalized nanoparticles on live cell membranes allow us to correlate rotational and translational dynamics in unprecedented detail and provide new insights for complex membrane processes, including electrostatic interactions, ligand-receptor binding, and lateral (confined and hopping) diffusion of membrane receptors. Surface-functionalized nanoparticles interact with the membrane in fundamentally different ways and exhibit distinct rotational modes. The early events of particle-membrane approach and attachment are directly visualized

  2. E-Alerts: Combustion, engines, and propellants (reciprocation and rotating combustion engines). E-mail newsletter

    SciTech Connect (OSTI)

    1999-04-01

    Design, performance, and testing of reciprocating and rotating engines of various configurations for all types of propulsion. Includes internal and external combustion engines; engine exhaust systems; engine air systems components; engine structures; stirling and diesel engines.

  3. Water-Efficient Technology Opportunity: Multi-Stream Rotational Sprinkler Heads

    Broader source: Energy.gov [DOE]

    FEMP identified multi-stream rotational sprinkler heads as a water-saving technology that is relevant to the federal sector, is commercially available, and offers significant water-savings potential.

  4. Low torque hydrodynamic lip geometry for bi-directional rotation seals

    DOE Patents [OSTI]

    Dietle, Lannie L.; Schroeder, John E.

    2009-07-21

    A hydrodynamically lubricating geometry for the generally circular dynamic sealing lip of rotary seals that are employed to partition a lubricant from an environment. The dynamic sealing lip is provided for establishing compressed sealing engagement with a relatively rotatable surface, and for wedging a film of lubricating fluid into the interface between the dynamic sealing lip and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or the counter-clockwise direction. A wave form incorporating an elongated dimple provides the gradual convergence, efficient impingement angle, and gradual interfacial contact pressure rise that are conducive to efficient hydrodynamic wedging. Skewed elevated contact pressure zones produced by compression edge effects provide for controlled lubricant movement within the dynamic sealing interface between the seal and the relatively rotatable surface, producing enhanced lubrication and low running torque.

  5. Low torque hydrodynamic lip geometry for bi-directional rotation seals

    DOE Patents [OSTI]

    Dietle, Lannie L.; Schroeder, John E.

    2011-11-15

    A hydrodynamically lubricating geometry for the generally circular dynamic sealing lip of rotary seals that are employed to partition a lubricant from an environment. The dynamic sealing lip is provided for establishing compressed sealing engagement with a relatively rotatable surface, and for wedging a film of lubricating fluid into the interface between the dynamic sealing lip and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or the counter-clockwise direction. A wave form incorporating an elongated dimple provides the gradual convergence, efficient impingement angle, and gradual interfacial contact pressure rise that are conducive to efficient hydrodynamic wedging. Skewed elevated contact pressure zones produced by compression edge effects provide for controlled lubricant movement within the dynamic sealing interface between the seal and the relatively rotatable surface, producing enhanced lubrication and low running torque.

  6. Rotating Disk-Electrode Aqueous Electrolyte Accelerated Stress Tests for PGM Electrocatalyst/Support Durability Evaluation

    Broader source: Energy.gov [DOE]

    Rotating disk-electrode aqueous electrolyte accelerated stress test protocols developed by the DOE Durability Working Group for platinum group metal (PGM) electrocatalyst/support durability evaluation, October 4, 2011.

  7. A comparison of optical and H I rotation curves in M 31

    SciTech Connect (OSTI)

    Kent, S.M. )

    1989-05-01

    New redshifts have been obtained for H II regions along the major axis. These data, combined with a reanalysis of previously published work, show that optical and 21-cm determinations of the rotation curve are in excellent agreement. 12 refs.

  8. The CU 2-D-MAX-DOAS instrument – Part 2: Raman scattering probability measurements and retrieval of aerosol optical properties

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ortega, Ivan; Coburn, Sean; Berg, Larry K.; Lantz, Kathy; Michalsky, Joseph; Ferrare, Richard A.; Hair, Johnathan W.; Hostetler, Chris A.; Volkamer, Rainer

    2016-08-23

    The multiannual global mean of aerosol optical depth at 550 nm (AOD550) over land is ∼ 0.19, and that over oceans is ∼ 0.13. About 45 % of the Earth surface shows AOD550 smaller than 0.1. There is a need for measurement techniques that are optimized to measure aerosol optical properties under low AOD conditions. We present an inherently calibrated retrieval (i.e., no need for radiance calibration) to simultaneously measure AOD and the aerosol phase function parameter, g, based on measurements of azimuth distributions of the Raman scattering probability (RSP), the near-absolute rotational Raman scattering (RRS) intensity. We employ radiative transfer model simulations tomore » show that for solar azimuth RSP measurements at solar elevation and solar zenith angle (SZA) smaller than 80°, RSP is insensitive to the vertical distribution of aerosols and maximally sensitive to changes in AOD and g under near-molecular scattering conditions. The University of Colorado two-dimensional Multi-AXis Differential Optical Absorption Spectroscopy (CU 2-D-MAX-DOAS) instrument was deployed as part of the Two Column Aerosol Project (TCAP) at Cape Cod, MA, during the summer of 2012 to measure direct sun spectra and RSP from scattered light spectra at solar relative azimuth angles (SRAAs) between 5 and 170°. During two case study days with (1) high aerosol load (17 July, 0.3  <  AOD430 < 0.6) and (2) near-molecular scattering conditions (22 July, AOD430 < 0.13) we compare RSP-based retrievals of AOD430 and g with data from a co-located CIMEL sun photometer, Multi-Filter Rotating Shadowband Radiometer (MFRSR), and an airborne High Spectral Resolution Lidar (HSRL-2). The average difference (relative to DOAS) for AOD430 is +0.012 ± 0.023 (CIMEL), −0.012 ± 0.024 (MFRSR), −0.011 ± 0.014 (HSRL-2), and +0.023 ± 0.013 (CIMELAOD − MFRSRAOD) and yields the following expressions for correlations between different instruments

  9. The OH rotational population and photodissociation of H{sub 2}O in DG Tauri

    SciTech Connect (OSTI)

    Carr, John S.; Najita, Joan R.

    2014-06-10

    We analyze the OH rotational emission in the Spitzer Space Telescope mid-infrared spectrum of the T Tauri star DG Tau. OH is observed in emission from upper level energies of 1900 K to 28,000 K. The rotational diagram cannot be fit with any single combination of temperature and column density and has slopes that correspond to excitation temperatures ranging from 200 K to 6000 K. The relative ?-doublet population within each rotational level is not equal, showing that the OH population is not in thermal equilibrium. The symmetric ?-doublet state is preferred in all rotational states, with an average of 0.5 for the population ratio of the anti-symmetric to symmetric state. We show that the population distribution of the high rotational lines and the ?-doublet ratio are consistent with the formation of OH following the photo-dissociation of H{sub 2}O by FUV photons in the second absorption band of water (?1150-1400 ), which includes Ly?. Other processes, OH formation from either photo-dissociation of water in the first absorption band (1450-1900 ) or the reaction O({sup 1} D) + H{sub 2}, or collisional excitation, cannot explain the observed emission in the high rotational states but could potentially contribute to the population of lower rotational levels. These results demonstrate that the photodissociation of water is active in DG Tau and support the idea that the hot rotational OH emission commonly observed in Classical T Tauri stars is due to the dissociation of H{sub 2}O by FUV radiation.

  10. Instrillment Development Multi-Spectral Automated Rotating Shadowt)and Radiometry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Instrillment Development Multi-Spectral Automated Rotating Shadowt)and Radiometry L. Harrison Atmospheric: Sciences Research Center State University of New York at Albany Albany, NY 12205 I am developing two related instruments for use in the Atmospheric Radiation Measurement (ARM) p,rogram; both use an automated rotating shadowband technique to make spectrally resolved measurements of the direct-normal, total horizontal, and diffuse horizontal irradiances. These parameters of the sky-radiance

  11. Apparatus and method for generating a magnetic field by rotation of a charge holding object

    DOE Patents [OSTI]

    Gerald, II, Rex E.; Vukovic, Lela; Rathke, Jerome W.

    2009-10-13

    A device and a method for the production of a magnetic field using a Charge Holding Object that is mechanically rotated. In a preferred embodiment, a Charge Holding Object surrounding a sample rotates and subjects the sample to one or more magnetic fields. The one or more magnetic fields are used by NMR Electronics connected to an NMR Conductor positioned within the Charge Holding Object to perform NMR analysis of the sample.

  12. Asymptotics of Unit Burger Number Rotating and Stratified Flows for Small

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aspect Ratio | Argonne Leadership Computing Facility Asymptotics of Unit Burger Number Rotating and Stratified Flows for Small Aspect Ratio Authors: Kurien, S., Smith, L.M. Rotating and stably stratified Boussinesq flow is investigated for Burger number unity in domain aspect ratio (height/horizontal length) δ Publication Date: June, 2011 Name of Publication Source: Science Direct Publisher: Elsevier B.V. Volume: 0 Issue: 0 Page Numbers: http://dx.doi.org/10.1016 Conference Location:

  13. Breakdown of the Brillouin limit and classical fluxes in rotating collisional plasmas

    SciTech Connect (OSTI)

    Rax, J. M.; Fruchtman, A.; Gueroult, R.; Fisch, N. J.

    2015-09-15

    The classical collisionless analysis displaying the occurrence of slow and fast rigid body rotation modes in magnetized plasmas is extended to collisional discharges. Collisions speed up the fast mode, slow down the slow one, and break down the classical Brillouin limit. Rigid body rotation has a strong impact on transport, and a collisional radial transport regime, different from the classical Braginskii collisional flux, is identified and analyzed.

  14. Polarization rotation of slow light with orbital angular momentum in ultracold atomic gases

    SciTech Connect (OSTI)

    Ruseckas, Julius; Juzeliunas, Gediminas; Oehberg, Patrik; Barnett, Stephen M.

    2007-11-15

    We consider the propagation of slow light with an orbital angular momentum (OAM) in a moving atomic medium. We have derived a general equation of motion and applied it in analyzing propagation of slow light with an OAM in a rotating medium, such as a vortex lattice. We have shown that the OAM of slow light manifests itself in a rotation of the polarization plane of linearly polarized light. To extract a pure rotational phase shift, we suggest to measure a difference in the angle of the polarization plane rotation by two consecutive light beams with opposite OAM. The differential angle {delta}{alpha}{sub l} is proportional to the rotation frequency of the medium {omega}{sub rot} and the winding number l of light, and is inversely proportional to the group velocity of light. For slow light the angle {delta}{alpha}{sub l} should be large enough to be detectable. The effect can be used as a tool for measuring the rotation frequency {omega}{sub rot} of the medium.

  15. Towards 3D mapping of BO₆ octahedron rotations at perovskite heterointerfaces, unit cell by unit cell

    SciTech Connect (OSTI)

    He, Qian; Ishikawa, Ryo; Lupini, Andrew R.; Qiao, Liang; Moon, Eun Ju; Ovchinnikov, Oleg S.; May, Steven J.; Biegalski, Michael D.; Borisevich, Albina Y.

    2015-01-01

    The rich functionalities in the ABO₃ perovskite oxides originate at least partly from the ability of the corner-connected BO₆ octahedral network to host a large variety of cations through distortions and rotations. Characterizing these rotations, which significantly affect both fundamental aspects of materials behavior and possible applications, remains a major challenge. In this work, we have developed a unique method of investigating BO₆ rotation patterns in complex oxides ABO₃ with unit cell resolution at heterointerfaces, where novel properties often emerge. Our method involves column shape analysis in annular bright field - scanning transmission electron microscope images of the ABO₃ heterointerfaces taken in specific orientations. The rotating phase of BO₆ octahedra can be identified for all three spatial dimensions without the need of case-by-case simulation. In several common rotation systems, it is now possible to quantitatively measure all three rotation angles. With this method, we examined interfaces between perovskites with distinct tilt systems as well as interfaces between tilted and untilted perovskites, identifying an unusual coupling behavior at the CaTiO₃/LSAT interface. We believe this unique method will significantly improve our knowledge of the complex oxide heterointerfaces.

  16. Towards 3D mapping of BO? octahedron rotations at perovskite heterointerfaces, unit cell by unit cell

    SciTech Connect (OSTI)

    He, Qian; Ishikawa, Ryo; Lupini, Andrew R.; Qiao, Liang; Moon, Eun Ju; Ovchinnikov, Oleg S.; May, Steven J.; Biegalski, Michael D.; Borisevich, Albina Y.

    2015-07-15

    The rich functionalities in the ABO? perovskite oxides originate at least partly from the ability of the corner-connected BO? octahedral network to host a large variety of cations through distortions and rotations. Characterizing these rotations, which significantly affect both fundamental aspects of materials behavior and possible applications, remains a major challenge. In this work, we have developed a unique method of investigating BO? rotation patterns in complex oxides ABO? with unit cell resolution at heterointerfaces, where novel properties often emerge. Our method involves column shape analysis in annular bright field - scanning transmission electron microscope images of the ABO? heterointerfaces taken in specific orientations. The rotating phase of BO? octahedra can be identified for all three spatial dimensions without the need of case-by-case simulation. In several common rotation systems, it is now possible to quantitatively measure all three rotation angles. With this method, we examined interfaces between perovskites with distinct tilt systems as well as interfaces between tilted and untilted perovskites, identifying an unusual coupling behavior at the CaTiO?/LSAT interface. We believe this unique method will significantly improve our knowledge of the complex oxide heterointerfaces.

  17. ANTISYMMETRY IN THE FARADAY ROTATION SKY CAUSED BY A NEARBY MAGNETIZED BUBBLE

    SciTech Connect (OSTI)

    Wolleben, M.; Landecker, T. L.; Fletcher, A.; Carretti, E.; McClure-Griffiths, N.; Dickey, J. M.; Gaensler, B. M.; Haverkorn, M.; Reich, W.; Taylor, A. R.

    2010-11-20

    Rotation measures (RMs) of pulsars and extragalactic point sources have been known to reveal large-scale antisymmetries in the Faraday rotation sky with respect to the Galactic plane and halo that have been interpreted as signatures of the mean magnetic field in the Galactic halo. We describe Faraday rotation measurements of the diffuse Galactic polarized radio emission over a large region in the northern Galactic hemisphere. Through application of RM synthesis we achieve sensitive Faraday rotation maps with high angular resolution, capable of revealing fine-scale structures of {approx}1{sup 0} in the Faraday rotation sky. Our analysis suggests that the observed antisymmetry in the Faraday rotation sky at b>0{sup 0} is dominated by the magnetic field around a local H I bubble at a distance of 100 pc, and not by the magnetic field of the Galactic halo. We derive physical properties of the magnetic field of this shell, which we find to be 20-34 {mu}G strong. It is clear that the diffuse polarized radio emission contains important information about the local magneto-ionic medium, which cannot yet be derived from Faraday RMs of extragalactic sources or pulsars alone.

  18. Towards 3D mapping of BO₆ octahedron rotations at perovskite heterointerfaces, unit cell by unit cell

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    He, Qian; Ishikawa, Ryo; Lupini, Andrew R.; Qiao, Liang; Moon, Eun Ju; Ovchinnikov, Oleg S.; May, Steven J.; Biegalski, Michael D.; Borisevich, Albina Y.

    2015-07-15

    The rich functionalities in the ABO₃ perovskite oxides originate at least partly from the ability of the corner-connected BO₆ octahedral network to host a large variety of cations through distortions and rotations. Characterizing these rotations, which significantly affect both fundamental aspects of materials behavior and possible applications, remains a major challenge. In this work, we have developed a unique method of investigating BO₆ rotation patterns in complex oxides ABO₃ with unit cell resolution at heterointerfaces, where novel properties often emerge. Our method involves column shape analysis in annular bright field - scanning transmission electron microscope images of the ABO₃ heterointerfacesmore » taken in specific orientations. The rotating phase of BO₆ octahedra can be identified for all three spatial dimensions without the need of case-by-case simulation. In several common rotation systems, it is now possible to quantitatively measure all three rotation angles. With this method, we examined interfaces between perovskites with distinct tilt systems as well as interfaces between tilted and untilted perovskites, identifying an unusual coupling behavior at the CaTiO₃/LSAT interface. We believe this unique method will significantly improve our knowledge of the complex oxide heterointerfaces.« less

  19. Diagnostics of the solar corona from comparison between Faraday rotation measurements and magnetohydrodynamic simulations

    SciTech Connect (OSTI)

    Le Chat, G.; Cohen, O.; Kasper, J. C.; Spangler, S. R.

    2014-07-10

    Polarized natural radio sources passing behind the Sun experience Faraday rotation as a consequence of the electron density and magnetic field strength in coronal plasma. Since Faraday rotation is proportional to the product of the density and the component of the magnetic field along the line of sight of the observer, a model is required to interpret the observations and infer coronal structures. Faraday rotation observations have been compared with relatively ad hoc models of the corona. Here for the first time we compare these observations with magnetohydrodynamic (MHD) models of the solar corona driven by measurements of the photospheric magnetic field. We use observations made with the NRAO Very Large Array of 34 polarized radio sources occulted by the solar corona between 5 and 14 solar radii. The measurements were made during 1997 May, and 2005 March and April. We compare the observed Faraday rotation values with values extracted from MHD steady-state simulations of the solar corona. We find that (1) using a synoptic map of the solar magnetic field just one Carrington rotation off produces poorer agreements, meaning that the outer corona changes in the course of one month, even in solar minimum; (2) global MHD models of the solar corona driven by photospheric magnetic field measurements are generally able to reproduce Faraday rotation observations; and (3) some sources show significant disagreement between the model and the observations, which appears to be a function of the proximity of the line of sight to the large-scale heliospheric current sheet.

  20. OBSERVABLE SIGNATURES OF PLANET ACCRETION IN RED GIANT STARS. I. RAPID ROTATION AND LIGHT ELEMENT REPLENISHMENT

    SciTech Connect (OSTI)

    Carlberg, Joleen K.; Cunha, Katia; Smith, Verne V.; Majewski, Steven R. E-mail: srm4n@virginia.edu E-mail: cunha@noao.edu

    2012-10-01

    The orbital angular momentum of a close-orbiting giant planet can be sufficiently large that, if transferred to the envelope of the host star during the red giant branch (RGB) evolution, it can spin-up the star's rotation to unusually large speeds. This spin-up mechanism is one possible explanation for the rapid rotators detected among the population of generally slow-rotating red giant stars. These rapid rotators thus comprise a unique stellar sample suitable for searching for signatures of planet accretion in the form of unusual stellar abundances due to the dissemination of the accreted planet in the stellar envelope. In this study, we look for signatures of replenishment in the Li abundances and (to a lesser extent) {sup 12}C/{sup 13}C, which are both normally lowered during RGB evolution. Accurate abundances were measured from high signal-to-noise echelle spectra for samples of both slow and rapid rotator red giant stars. We find that the rapid rotators are on average enriched in lithium compared to the slow rotators, but both groups of stars have identical distributions of {sup 12}C/{sup 13}C within our measurement precision. Both of these abundance results are consistent with the accretion of planets of only a few Jupiter masses. We also explore alternative scenarios for understanding the most Li-rich stars in our sample-particularly Li regeneration during various stages of stellar evolution. Finally, we find that our stellar samples show non-standard abundances even at early RGB stages, suggesting that initial protostellar Li abundances and {sup 12}C/{sup 13}C may be more variable than originally thought.

  1. Improved generator for use with low-speed rotating machines. Final report

    SciTech Connect (OSTI)

    Goerz, J.W.

    1983-03-31

    The goal of this project was to construct a low-technology, maintenance-free dc electrical generator suited for use with low-speed rotating machines such as windmills or waterwheels. The generator consists of permanent magnets affixed to the circumference of the rotating device, and stationary coils mounted on a semicircular frame. As the device rotates, the magnets move past the coils and magnetically induce an ac voltage in the coils. This voltage is rectified and stored in a battery. No gears, belts, or brushes are used, so the generator operates quietly and without maintenance. The purpose of mounting the magnets at the circumference of the rotating device is to achieve high relative velocities between magnets and coils even at slow rotations, in the hope of extracting energy from very light winds or slowly flowing water. Such a generator was constructed as part of a ten-foot-diameter windmill to test the concept. The generator easily reaches charging voltages at low speeds, and operates quietly without mechanical wear. But the charging current is very low in comparison to a wind turbine of conventional design. The experiment allows fundamental design problems to be identified.

  2. The formation of molecular hydrogen on silicate dust analogs: The rotational distribution

    SciTech Connect (OSTI)

    Gavilan, L.; Lemaire, J. L.; Vidali, G.; Sabri, T.; Jger, C.

    2014-02-01

    Our laboratory experiments continue to explore how the formation of molecular hydrogen is influenced by dust and how dust thereby affects hydrogen molecules adsorbed on its surface. In Sabri et al., we present the preparation of nanometer-sized silicate grain analogs via laser ablation. These analogs illustrate extremes in structure (fully crystalline or fully amorphous grains), and stoichiometry (the forsterite and fayalite end-members of the olivine family). These were inserted in FORMOLISM, an ultra-high vacuum setup where they can be cooled down to ?5 K. Atomic beams are directed at these surfaces and the formation of new molecules is studied via REMPI(2+1) spectroscopy. We explored the rotational distribution (0 ? J'' ? 5) of v'' = 0 of the ground electronic state of H{sub 2}. The results of these measurements are reported here. Surprisingly, molecules formed and ejected from crystalline silicates have a cold (T {sub rot} ? 120 K) rotational energy distribution, while for molecules formed on and ejected from amorphous silicate films, the rotational temperature is ?310 K. These results are compared to previous experiments on metallic surfaces and theoretical simulations. Solid-state surface analysis suggests that flatter grains could hinder the 'cartwheel' rotation mode. A search for hot hydrogen, predicted as a result of H{sub 2} formation, hints at its production. For the first time, the rotational distribution of hydrogen molecules formed on silicate dust is reported. These results are essential to understanding the chemistry of astrophysical media containing bare dust grains.

  3. Landau electron in a rotating environment: A general factorization of time evolution

    SciTech Connect (OSTI)

    Chee, J.

    2012-11-15

    For the Landau problem with a rotating magnetic field and a confining potential in the (changing) direction of the field, we derive a general factorization of the time evolution operator that includes the adiabatic factorization as a special case. The confining potential is assumed to be of a general form and it can correspond to nonlinear Heisenberg equations of motion. The rotation operator associated with the solid angle Berry phase is used to transform the problem to a rotating reference frame. In the rotating reference frame, we derive a natural factorization of the time evolution operator by recognizing the crucial role played by a gauge transformation. The major complexity of the problem arises from the coupling between motion in the direction of the magnetic field and motion perpendicular to the field. In the factorization, this complexity is consolidated into a single operator which approaches the identity operator when the potential confines the particle sufficiently close to a rotating plane perpendicular to the magnetic field. The structure of this operator is clarified by deriving an expression for its generating Hamiltonian. The adiabatic limit and non-adiabatic effects follow as consequences of the general factorization which are clarified using the magnetic translation concept.

  4. NUMERICAL SIMULATIONS OF Z-PINCH EXPERIMENTS TO CREATE SUPERSONIC DIFFERENTIALLY ROTATING PLASMA FLOWS

    SciTech Connect (OSTI)

    Bocchi, M.; Ummels, B.; Chittenden, J. P.; Lebedev, S. V.; Frank, A.; Blackman, E. G.

    2013-04-10

    The physics of accretion disks is of fundamental importance for understanding of a wide variety of astrophysical sources that includes protostars, X-ray binaries, and active galactic nuclei. The interplay between hydrodynamic flows and magnetic fields and the potential for turbulence-producing instabilities is a topic of active research that would benefit from the support of dedicated experimental studies. Such efforts are in their infancy, but in an effort to push the enterprise forward we propose an experimental configuration which employs a modified cylindrical wire array Z-pinch to produce a rotating plasma flow relevant to accretion disks. We present three-dimensional resistive magnetohydrodynamic simulations which show how this approach can be implemented. In the simulations, a rotating plasma cylinder or ring is formed, with typical rotation velocity {approx}30 km s{sup -1}, Mach number {approx}4, and Reynolds number in excess of 10{sup 7}. The plasma is also differentially rotating. Implementation of different external magnetic field configurations is discussed. It is found that a modest uniform vertical field of 1 T can affect the dynamics of the system and could be used to study magnetic field entrainment and amplification through differential rotation. A dipolar field potentially relevant to the study of accretion columns is also considered.

  5. The transverse and rotational motions of magnetohydrodynamic kink waves in the solar atmosphere

    SciTech Connect (OSTI)

    Goossens, M.; Van Doorsselaere, T. [Centre for Mathematical Plasma Astrophysics, Katholieke Universiteit Leuven, Celestijnenlaan 200B, bus 2400, B-3001 Herverlee (Belgium); Soler, R.; Terradas, J. [Departament de Fsica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Verth, G., E-mail: marcel.goossens@wis.kuleuven.be [Solar Physics and Space Plasma Research Centre (SP2RC), The University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2014-06-10

    Magnetohydrodynamic (MHD) kink waves have now been observed to be ubiquitous throughout the solar atmosphere. With modern instruments, they have now been detected in the chromosphere, interface region, and corona. The key purpose of this paper is to show that kink waves do not only involve purely transverse motions of solar magnetic flux tubes, but the velocity field is a spatially and temporally varying sum of both transverse and rotational motion. Taking this fact into account is particularly important for the accurate interpretation of varying Doppler velocity profiles across oscillating structures such as spicules. It has now been shown that, as well as bulk transverse motions, spicules have omnipresent rotational motions. Here we emphasize that caution should be used before interpreting the particular MHD wave mode/s responsible for these rotational motions. The rotational motions are not necessarily signatures of the classic axisymmetric torsional Alfvn wave alone, because kink motion itself can also contribute substantially to varying Doppler velocity profiles observed across these structures. In this paper, the displacement field of the kink wave is demonstrated to be a sum of its transverse and rotational components, both for a flux tube with a discontinuous density profile at its boundary, and one with a more realistic density continuum between the internal and external plasma. Furthermore, the Doppler velocity profile of the kink wave is forward modeled to demonstrate that, depending on the line of sight, it can either be quite distinct or very similar to that expected from a torsional Alfvn wave.

  6. Dynamic control of rotating stall in axial flow compressors using aeromechanical feedback

    SciTech Connect (OSTI)

    Gysling, D.L.; Greitzer, E.M.

    1995-07-01

    Dynamic control of rotating stall in an axial flow compressor has been implemented using aeromechanical feedback. The control strategy developed used an array of wall jets, upstream of a single-stage compressor, which were regulated by locally reacting reed valves. These reed valves responded to the small-amplitude flow-field pressure perturbations that precede rotating stall. The valve design was such that the combined system, compressor plus reed valve controller, was stable under operating conditions that had been unstable without feedback. A 10 percent decrease in the stalling flow coefficient was obtained using the control strategy, and the extension of stall flow range was achieved with no measurable change in the steady-state performance of the compression system. The experiments demonstrate the first use of aeromechanical feedback to extend the stable operating range of an axial flow compressor, and the first use of local feedback and dynamic compensation techniques to suppress rotating stall. The design of the experiment was based on a two-dimensional stall inception model, which incorporated the effect of the aeromechanical feedback. The physical mechanism for rotating stall in axial flow compressors was examined with focus on the role of dynamic feedback in stabilizing compression system instability. As predicted and experimentally demonstrated, the effectiveness of the aeromechanical control strategy depends on a set of nondimensional control parameters that determine the interaction of the control strategy and the rotating stall dynamics.

  7. Kink instability evidenced by analyzing the leg rotation of a filament

    SciTech Connect (OSTI)

    Yan, X. L.; Xue, Z. K.; Ma, L.; Kong, D. F.; Qu, Z. Q.; Liu, J. H.; Li, Z.

    2014-02-20

    Kink instability is a possible mechanism for solar filament eruption. However, it is very difficult to directly measure the twist of the solar filament from observation. In this paper, we measured the twist of a solar filament by analyzing its leg rotation. An inverse S-shaped filament in the active region NOAA 11485 was observed by the Atmospheric Imaging Assembly of the Solar Dynamics Observatory on 2012 May 22. During its eruption, the leg of the filament exhibited a significant rotation motion. The 304 images were used to uncurl the circles, the centers of which are the axis of the filament's leg. The result shows that the leg of the filament rotated up to about 510 (about 2.83?) around the axis of the filament within 23 minutes. The maximal rotation speed reached 100 degrees/minute (about 379.9 km s{sup 1} at radius 18''), which is the fastest rotation speed reported. We also calculated the decay index along the polarity inversion line in this active region and found that the decline of the overlying field with height is not fast enough to trigger the torus instability. According to the kink instability condition, this indicates that the kink instability is the trigger mechanism for the solar filament eruption.

  8. Evaluate fundamental approaches to longwall dust control: Subprogram F, Reversed drum rotation

    SciTech Connect (OSTI)

    Ludlow, J.; Kelly, J.; Ruggieri, S.

    1990-05-01

    In longwall mining, a significant portion of the shearer operator's dust exposure is caused by dust generated during loading. With the conventional direction of shearer drum rotation, loading efficiency is usually poor due to obstructions caused by the ranging arms and the cowl support arms. By reversing the normal direction of rotation, however, the arms no longer provide an obstruction. This results in improved loading efficiency and reduced dust generation. This report describes the reversed drum rotation concept and presents the results of a field survey and underground evaluation conducted to prove its feasibility and to measure its dust control benefits. Through this effort, the technique was shown to be feasible from both a mining and mechanical standpoint. During the underground test, it reduced dust levels near the shearer operator's positions by about 85%. 20 figs., 4 tabs.

  9. Seal assembly with anti-rotation pin for high pressure supercritical fluids

    DOE Patents [OSTI]

    Wright, Steven A.; Fuller, Robert L.

    2014-08-05

    A seal assembly for sealing a machine with a first chamber and a second chamber is provided. A rotating shaft extends through the first and second chambers, and rotates therein. The seal assembly has a seal housing, a seal ring and a seal pin. The seal housing is positionable in the machine housing. The seal housing has a seal pocket extending into a fluid side thereof, and a housing receptacle extending into an inner diameter thereof at the seal pocket. The seal ring is positionable in the seal pocket of the seal housing for forming a seal therewith. The seal ring has a ring receptacle extending into an outer diameter thereof. The ring receptacle is positionable adjacent to the housing receptacle for defining a pin hole therebetween. The seal pin is loosely positionable in the pin hole whereby movement about the seal ring is accommodated while preventing rotation thereof.

  10. Stud hardware with self-contained stud anti-rotation feature and method of installing studs

    DOE Patents [OSTI]

    Kartik, John S.; Richardson, William M.

    1986-01-01

    Disclosed herein is a method and apparatus for preventing the rotation of a stud member during preloading. The apparatus comprises a stud member having a shaft portion extending into the member to be clamped and a hex or double hex portion carrying a locking nut. Extending outward from the hex or double hex portion of the stud there is a threaded portion carrying a nut which is torqued to preload the stud. Between the locking nut and the member to be clamped is a locking ring which engages the locking nut to prevent the stud from rotating during preloading. Also disclosed is a method of preloading a stud without the use of an external restraint to prevent the stud from rotating when a torque is applied.

  11. Femtosecond pure-rotational coherent anti-stokes raman scattering gas phase diagnostics.

    SciTech Connect (OSTI)

    Kearney, Sean Patrick; Serrano, Justin Raymond

    2010-12-01

    We discuss recent experiments for the characterization of our femtosecond pure rotational CARS facility for observation of Raman transients in N{sub 2} and atmospheric air. The construction of a simplified femtosecond four-wave mixing system with only a single laser source is presented. Pure-rotational Raman transients reveal well-ordered time-domain recurrence peaks associated with the near-uniform spacing of rotational Raman peaks in the spectral domain. Long-time, 100-ps duration observations of the transient Raman polarization are presented, and the observed transients are compared to simulated results. Fourier transformation of the transients reveals two distinct sets of beat frequencies. Simulation results for temperatures from 300-700 K are used to illustrate the temperature sensitivity of the time-domain transients and their Fourier-transform counterparts. And strategies for diagnostics are briefly discussed. These results are being utilized to develop gas-phase measurement strategies for temperature and species concentration.

  12. Tokamak plasma equilibrium problems with anisotropic pressure and rotation and their numerical solution

    SciTech Connect (OSTI)

    Ivanov, A. A. Martynov, A. A. Medvedev, S. Yu. Poshekhonov, Yu. Yu.

    2015-03-15

    In the MHD tokamak plasma theory, the plasma pressure is usually assumed to be isotropic. However, plasma heating by neutral beam injection and RF heating can lead to a strong anisotropy of plasma parameters and rotation of the plasma. The development of MHD equilibrium theory taking into account the plasma inertia and anisotropic pressure began a long time ago, but until now it has not been consistently applied in computational codes for engineering calculations of the plasma equilibrium and evolution in tokamak. This paper contains a detailed derivation of the axisymmetric plasma equilibrium equation in the most general form (with arbitrary rotation and anisotropic pressure) and description of the specialized version of the SPIDER code. The original method of calculation of the equilibrium with an anisotropic pressure and a prescribed rotational transform profile is proposed. Examples of calculations and discussion of the results are also presented.

  13. Rotation-Enabled 7-Degree of Freedom Seismometer for Geothermal Resource Development. Phase 1 Final Report

    SciTech Connect (OSTI)

    Pierson, Bob; Laughlin, Darren

    2013-10-29

    Under this Department of Energy (DOE) grant, A-Tech Corporation d.b.a. Applied Technology Associates (ATA), seeks to develop a seven-degree-of-freedom (7-DOF) seismic measurement tool for high-temperature geothermal applications. The Rotational-Enabled 7-DOF Seismometer includes a conventional tri-axial accelerometer, a conventional pressure sensor or hydrophone, and a tri-axial rotational sensor. The rotational sensing capability is novel, based upon ATA's innovative research in rotational sensing technologies. The geothermal industry requires tools for high-precision seismic monitoring of crack formation associated with Enhanced Geothermal System (EGS) stimulation activity. Currently, microseismic monitoring is conducted by deploying many seismic tools at different depth levels along a 'string' within drilled observation wells. Costs per string can be hundreds of thousands of dollars. Processing data from the spatial arrays of linear seismometers allows back-projection of seismic wave states. In contrast, a Rotational-Enabled 7-DOF Seismometer would simultaneously measure p-wave velocity, s-wave velocity, and incident seismic wave direction all from a single point measurement. In addition, the Rotational-Enabled 7-DOF Seismometer will, by its nature, separate p- and s-waves into different data streams, simplifying signal processing and facilitating analysis of seismic source signatures and geological characterization. By adding measurements of three additional degrees-of-freedom at each level and leveraging the information from this new seismic observable, it is likely that an equally accurate picture of subsurface seismic activity could be garnered with fewer levels per hole. The key cost savings would come from better siting of the well due to increased information content and a decrease in the number of confirmation wells drilled, also due to the increase in information per well. Improved seismic tools may also increase knowledge, understanding, and confidence

  14. Pseudo-rotational epitaxy of self-assembled octadecyltrichlorosilane monolayers on sapphire (0001)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Steinruck, H. -G.; Ocko, B. M.; Magerl, A.; Deutsch, M.

    2014-10-06

    The structure of octadecyltrichlorosilane self-assembled monolayers (SAMs) on sapphire (0001) was studied by -resolution surface-specific x-ray scattering methods. The monolayer was found to consist of three sublayers where the outermost layer corresponds to vertically oriented, closely packed alkyl tails. Laterally, the monolayer is hexagonally packed and exhibits pseudorotational epitaxy to the sapphire, manifested by a broad scattering peak at zero relative azimuthal rotation, with long powderlike tails. The lattice mismatch of ~1% 3% to the sapphires and the different length scale introduced by the lateral Si-O-Si bonding prohibit positional epitaxy. However, the substrate induces an intriguing increase in themorecrystalline coherence length of the SAMs powderlike crystallites when rotationally aligned with the sapphires lattice. The increase correlates well with the rotational dependence of the separation of corresponding substrate-monolayer lattice sites.less

  15. Selective control of the states of multilevel quantum systems using nonselective rotation operators

    SciTech Connect (OSTI)

    Zobov, V. E. Shauro, V. P.

    2009-01-15

    We have calculated the sequences of nonselective rotation operators separated by intervals of free evolution that perform selective rotations between adjacent levels in systems with three, four, five, and six nonequidistant levels. We have numerically simulated the realization of the calculated sequences for quadrupole nuclei with corresponding spins controlled by intense nonselective radio-frequency (RF) pulses and investigated the dependences of the realization error on the parameters of external and internal interactions. To reduce the error when the RF field is not strong enough, we have found composite nonselective RF pulses consisting of five simple ones. We show that the error of the composite selective rotation operator can be reduced signifi- cantly in comparison to the error of a simple single selective pulse.

  16. Rigid-body rotation of an electron cloud in divergent magnetic fields

    SciTech Connect (OSTI)

    Fruchtman, A.; Gueroult, R.; Fisch, N. J.

    2013-07-15

    For a given voltage across a divergent poloidal magnetic field, two electric potential distributions, each supported by a rigid-rotor electron cloud rotating with a different frequency, are found analytically. The two rotation frequencies correspond to the slow and fast rotation frequencies known in uniform plasma. Due to the centrifugal force, the equipotential surfaces, that correspond to the two electric potential distributions, diverge more than the magnetic surfaces do, the equipotential surfaces in the fast mode diverge largely in particular. The departure of the equipotential surfaces from the magnetic field surfaces may have a significant focusing effect on the ions accelerated by the electric field. The focusing effect could be important for laboratory plasma accelerators as well as for collimation of astrophysical jets.

  17. Causal extraction of black hole rotational energy by various kinds of electromagnetic fields

    SciTech Connect (OSTI)

    Koide, Shinji; Baba, Tamon

    2014-09-10

    Recent general relativistic magnetohydrodynamics (MHD) simulations have suggested that relativistic jets from active galactic nuclei (AGNs) have been powered by the rotational energy of central black holes. Some mechanisms for extraction of black hole rotational energy have been proposed, like the Penrose process, Blandford-Znajek mechanism, MHD Penrose process, and superradiance. The Blandford-Znajek mechanism is the most promising mechanism for the engines of the relativistic jets from AGNs. However, an intuitive interpretation of this mechanism with causality is not yet clarified, while the Penrose process has a clear interpretation for causal energy extraction from a black hole with negative energy. In this paper, we present a formula to build physical intuition so that in the Blandford-Znajek mechanism, as well as in other electromagnetic processes, negative electromagnetic energy plays an important role in causal extraction of the rotational energy of black holes.

  18. Competition in rotation-alignment between high-j neutrons and protons in transfermium nuclei

    SciTech Connect (OSTI)

    Al-Khudair, Falih; Long Guilu; Sun Yang

    2009-03-15

    The study of rotation-alignment of quasiparticles probes sensitively the properties of high-j intruder orbits. The distribution of very-high-j orbits, which are consequences of the fundamental spin-orbit interaction, links with the important question of single-particle levels in superheavy nuclei. With the deformed single-particle states generated by the standard Nilsson potential, we perform Projected Shell Model calculations for transfermium nuclei where detailed spectroscopy experiments are currently possible. Specifically, we study the systematical behavior of rotation-alignment and associated band-crossing phenomenon in Cf, Fm, and No isotopes. Neutrons and protons from the high-j orbits are found to compete strongly in rotation-alignment, which gives rise to testable effects. Observation of these effects will provide direct information on the single-particle states in the heaviest nuclear mass region.

  19. Self locking drive system for rotating plug of a nuclear reactor

    DOE Patents [OSTI]

    Brubaker, James E.

    1979-01-01

    This disclosure describes a self locking drive system for rotating the plugs on the head of a nuclear reactor which is able to restrain plug motion if a seismic event should occur during reactor refueling. A servomotor is engaged via a gear train and a bull gear to the plug. Connected to the gear train is a feedback control system which allows the motor to rotate the plug to predetermined locations for refueling of the reactor. The gear train contains a self locking double enveloping worm gear set. The worm gear set is utilized for its self locking nature to prevent unwanted rotation of the plugs as the result of an earthquake. The double enveloping type is used because its unique contour spreads the load across several teeth providing added strength and allowing the use of a conventional size worm.

  20. Rigid-body rotation of an electron cloud in divergent magnetic fields

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fruchtman, A.; Gueroult, R.; Fisch, N. J.

    2013-07-10

    For a given voltage across a divergent poloidal magnetic field, two electric potential distributions, each supported by a rigid-rotor electron cloud rotating with a different frequency, are found analytically. The two rotation frequencies correspond to the slow and fast rotation frequencies known in uniform plasma. Due to the centrifugal force, the equipotential surfaces, that correspond to the two electric potential distributions, diverge more than the magnetic surfaces do, the equipotential surfaces in the fast mode diverge largely in particular. The departure of the equipotential surfaces from the magnetic field surfaces may have a significant focusing effect on the ions acceleratedmore » by the electric field. Furthermore, the focusing effect could be important for laboratory plasma accelerators as well as for collimation of astrophysical jets.« less

  1. Tendency of a rotating electron plasma to approach the Brillouin limit

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gueroult, Renaud; Fruchtman, Amnon; Fisch, Nathaniel J.

    2013-07-24

    In this study, a neutral plasma is considered to be immersed in an axial magnetic field together with a radial electric field. If the electrons are magnetized, but the ions are not magnetized, then the electrons will rotate but the ions will not rotate, leading to current generation. The currents, in turn, weaken the axial magnetic field, leading to an increase in the rotation frequency of the slow Brillouin mode. This produces a positive feedback effect, further weakening the magnetic field. The operating point thus tends to drift towards the Brillouin limit, possibly finding stability only in proximity to themore » limit itself. An example of this effect might be the cylindrical Hall thruster configuration.« less

  2. Combined Néel and Brown rotational Langevin dynamics in magnetic particle imaging, sensing, and therapy

    SciTech Connect (OSTI)

    Reeves, Daniel B.; Weaver, John B.

    2015-11-30

    Magnetic nanoparticles have been studied intensely because of their possible uses in biomedical applications. Biosensing using the rotational freedom of particles has been used to detect biomarkers for cancer, hyperthermia therapy has been used to treat tumors, and magnetic particle imaging is a promising new imaging modality that can spatially resolve the concentration of nanoparticles. There are two mechanisms by which the magnetization of a nanoparticle can rotate, a fact that poses a challenge for applications that rely on precisely one mechanism. The challenge is exacerbated by the high sensitivity of the dominant mechanism to applied fields. Here, we demonstrate stochastic Langevin equation simulations for the combined rotation in magnetic nanoparticles exposed to oscillating applied fields typical to these applications to both highlight the existing relevant theory and quantify which mechanism should occur in various parameter ranges.

  3. Method and apparatus for separating continuous cast strip from a rotating substrate

    DOE Patents [OSTI]

    King, Edward L.; Follstaedt, Donald W.; Sussman, Richard C.

    1991-01-01

    The continuous casting of strip, ribbon and wire is improved by using a free jet nozzle which provides a fluid that follows a rotating substrate surface to the separation point. The nozzle includes an inclined surface having a ratio of its length to the gap between the substrate and the nozzle edge of 5:1 to 15:1. The inclined surface improves the ability of the jet to tangentially follow the substrate in a direction opposite to its rotation to the separation point. This also allows a close positioning of the nozzle to the substrate which serves to provide a back-up mechanical separation means by using the edge of nozzle lip. The nozzle may be rotated from its operating position for cleaning of the substrate and the nozzle.

  4. Method and apparatus for separating continuous cast strip from a rotating substrate

    DOE Patents [OSTI]

    King, E.L.; Follstaedt, D.W.; Sussman, R.C.

    1991-08-20

    The continuous casting of strip, ribbon and wire is improved by using a free jet nozzle which provides a fluid that follows a rotating substrate surface to the separation point. The nozzle includes an inclined surface having a ratio of its length to the gap between the substrate and the nozzle edge of 5:1 to 15:1. The inclined surface improves the ability of the jet to tangentially follow the substrate in a direction opposite to its rotation to the separation point. This also allows a close positioning of the nozzle to the substrate which serves to provide a back-up mechanical separation means by using the edge of nozzle lip. The nozzle may be rotated from its operating position for cleaning of the substrate and the nozzle. 4 figures.

  5. Surface--micromachined rotatable member having a low-contact-area hub

    DOE Patents [OSTI]

    Rodgers, M. Steven; Sniegowski, Jeffry J.

    2002-01-01

    A surface-micromachined rotatable member formed on a substrate and a method for manufacturing thereof are disclosed. The surface-micromachined rotatable member, which can be a gear or a rotary stage, has a central hub, and an annulus connected to the central hub by an overarching bridge. The hub includes a stationary axle support attached to the substrate and surrounding an axle. The axle is retained within the axle support with an air-gap spacing therebetween of generally 0.3 .mu.m or less. The rotatable member can be formed by alternately depositing and patterning layers of a semiconductor (e.g. polysilicon or a silicon-germanium alloy) and a sacrificial material and then removing the sacrificial material, at least in part. The present invention has applications for forming micromechanical or microelectromechanical devices requiring lower actuation forces, and providing improved reliability.

  6. Surface-micromachined rotatable member having a low-contact-area hub

    DOE Patents [OSTI]

    Rodgers, M. Steven; Sniegowski, Jeffry J.; Krygowski, Thomas W.

    2003-11-18

    A surface-micromachined rotatable member formed on a substrate and a method for manufacturing thereof are disclosed. The surface-micromachined rotatable member, which can be a gear or a rotary stage, has a central hub, and an annulus connected to the central hub by an overarching bridge. The hub includes a stationary axle support attached to the substrate and surrounding an axle. The axle is retained within the axle support with an air-gap spacing therebetween of generally 0.3 .mu.m or less. The rotatable member can be formed by alternately depositing and patterning layers of a semiconductor (e.g. polysilicon or a silicon-germanium alloy) and a sacrificial material and then removing the sacrificial material, at least in part. The present invention has applications for forming micromechanical or microelectromechanical devices requiring lower actuation forces, and providing improved reliability.

  7. JET ROTATION INVESTIGATED IN THE NEAR-ULTRAVIOLET WITH THE HUBBLE SPACE TELESCOPE IMAGING SPECTROGRAPH

    SciTech Connect (OSTI)

    Coffey, Deirdre; Ray, Thomas P.; Rigliaco, Elisabetta; Bacciotti, Francesca; Eisloeffel, Jochen

    2012-04-20

    We present results of the second phase of our near-ultraviolet investigation into protostellar jet rotation using the Hubble Space Telescope Imaging Spectrograph. We obtain long-slit spectra at the base of five T Tauri jets to determine if there is a difference in radial velocity between the jet borders which may be interpreted as a rotation signature. These observations are extremely challenging and push the limits of current instrumentation, but have the potential to provide long-awaited observational support for the magnetocentrifugal mechanism of jet launching in which jets remove angular momentum from protostellar systems. We successfully detect all five jet targets (from RW Aur, HN Tau, DP Tau, and CW Tau) in several near-ultraviolet emission lines, including the strong Mg II doublet. However, only RW Aur's bipolar jet presents a sufficiently high signal-to-noise ratio to allow for analysis. The approaching jet lobe shows a difference of 10 km s{sup -1} in a direction which agrees with the disk rotation sense, but is opposite to previously published optical measurements for the receding jet. The near-ultraviolet difference is not found six months later, nor is it found in the fainter receding jet. Overall, in the case of RW Aur, differences are not consistent with a simple jet rotation interpretation. Indeed, given the renowned complexity and variability of this system, it now seems likely that any rotation signature is confused by other influences, with the inevitable conclusion that RW Aur is not suited to a jet rotation study.

  8. A High-Precision Instrument for Mapping of Rotational Errors in Rotary Stages

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, W.; Lauer, K.; Chu, Y.; Nazaretski, E.

    2014-11-02

    A rotational stage is a key component of every X-ray instrument capable of providing tomographic or diffraction measurements. To perform accurate three-dimensional reconstructions, runout errors due to imperfect rotation (e.g. circle of confusion) must be quantified and corrected. A dedicated instrument capable of full characterization and circle of confusion mapping in rotary stages down to the sub-10 nm level has been developed. A high-stability design, with an array of five capacitive sensors, allows simultaneous measurements of wobble, radial and axial displacements. The developed instrument has been used for characterization of two mechanical stages which are part of an X-ray microscope.

  9. Optical trapping and rotation of airborne absorbing particles with a single focused laser beam

    SciTech Connect (OSTI)

    Lin, Jinda; Li, Yong-qing, E-mail: liy@ecu.edu [Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353 (United States)] [Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353 (United States)

    2014-03-10

    We measure the periodic circular motion of single absorbing aerosol particles that are optically trapped with a single focused Gaussian beam and rotate around the laser propagation direction. The scattered light from the trapped particle is observed to be directional and change periodically at 0.420?kHz. The instantaneous positions of the moving particle within a rotation period are measured by a high-speed imaging technique using a charge coupled device camera and a repetitively pulsed light-emitting diode illumination. The centripetal acceleration of the trapped particle as high as ?20 times the gravitational acceleration is observed and is attributed to the photophoretic forces.

  10. Rotating-frame gradient fields for magnetic resonance imaging and nuclear magnetic resonance in low fields

    DOE Patents [OSTI]

    Bouchard, Louis-Serge; Pines, Alexander; Demas, Vasiliki

    2014-01-21

    A system and method for Fourier encoding a nuclear magnetic resonance (NMR) signal is disclosed. A static magnetic field B.sub.0 is provided along a first direction. An NMR signal from the sample is Fourier encoded by applying a rotating-frame gradient field B.sub.G superimposed on the B.sub.0, where the B.sub.G comprises a vector component rotating in a plane perpendicular to the first direction at an angular frequency .omega.in a laboratory frame. The Fourier-encoded NMR signal is detected.

  11. In-line rotating torque sensor with on-board amplifier

    DOE Patents [OSTI]

    Kronberg, James W.

    1990-01-01

    A rotating torque sensor apparatus and method for measuring small torques comprising a shaft, a platform having a circuit board and a first moment arm attached to the shaft, a rotatable wheel coaxial with the shaft and having a second moment arm spaced apart from the first moment arm with a load cell therebetween for generating an electric signal as the torque is applied to the shaft and transferred through the moment arms to the load cell. The electrical signal is conducted from the load cell to the circuit board for filtering and amplification before being extracted from the torque assembly through a slip ring.

  12. Fast strain wave induced magnetization changes in long cobalt bars: Domain motion versus coherent rotation

    SciTech Connect (OSTI)

    Davis, S.; Adenwalla, S.; Borchers, J. A.; Maranville, B. B.

    2015-02-14

    A high frequency (88 MHz) traveling strain wave on a piezoelectric substrate is shown to change the magnetization direction in 40 μm wide Co bars with an aspect ratio of 10{sup 3}. The rapidly alternating strain wave rotates the magnetization away from the long axis into the short axis direction, via magnetoelastic coupling. Strain-induced magnetization changes have previously been demonstrated in ferroelectric/ferromagnetic heterostructures, with excellent fidelity between the ferromagnet and the ferroelectric domains, but these experiments were limited to essentially dc frequencies. Both magneto-optical Kerr effect and polarized neutron reflectivity confirm that the traveling strain wave does rotate the magnetization away from the long axis direction and both yield quantitatively similar values for the rotated magnetization. An investigation of the behavior of short axis magnetization with increasing strain wave amplitude on a series of samples with variable edge roughness suggests that the magnetization reorientation that is seen proceeds solely via coherent rotation. Polarized neutron reflectivity data provide direct experimental evidence for this model. This is consistent with expectations that domain wall motion cannot track the rapidly varying strain.

  13. Fiber optic sensor system for detecting movement or position of a rotating wheel bearing

    DOE Patents [OSTI]

    Veeser, Lynn R.; Rodriguez, Patrick J.; Forman, Peter R.; Monahan, Russell E.; Adler, Jonathan M.

    1997-01-01

    An improved fiber optic sensor system and integrated sensor bearing assembly for detecting movement or position of a rotating wheel bearing having a multi-pole tone ring which produces an alternating magnetic field indicative of movement and position of the rotating member. A magneto-optical material, such as a bismuth garnet iron (B.I.G.) crystal, having discrete magnetic domains is positioned in the vicinity of the tone ring so that the domains align themselves to the magnetic field generated by the tone ring. A single fiber optic cable, preferably single mode fiber, carries light generated by a source of light to the B.I.G. crystal. The light passes through the B.I.G. crystal and is refracted at domain boundaries in the crystal. The intensity of the refracted light is indicative of the amount of alignment of the domains and therefore the strength of the magnetic field. The refracted light is carried by the fiber optic cable to an optic receiver where the intensity is measured and an electrical signal is generated and sent to a controller indicating the frequency of the changes in light intensity and therefore the rotational speed of the rotating wheel bearing.

  14. Imaging Hindered Rotations of Alkoxy Species on TiO2(110)

    SciTech Connect (OSTI)

    Zhang, Zhenrong; Rousseau, Roger J.; Gong, Jinlong; Kay, Bruce D.; Dohnalek, Zdenek

    2009-12-16

    We present the first study of the rotational dynamics of organic species on any oxide surface. Specifically, variable-temperature scanning tunneling microscopy (STM) and dispersion-corrected density functional theory are used to study the alkyl chain conformational disorder and dynamics of 1-, 2-, 3- and 4-octoxy on rutile TiO2(110). Initially, the geminate pairs of the octoxy and bridging hydroxyl species are created via octanol dissociation on bridging-oxygen (Ob) vacancy defects. The STM images provide time averaged snapshots of octoxy species rotating among multiple energetically nearly-degenerate configurations accessible at a given temperature. In the calculations we find that the underlying corrugated potential energy surface is a result of the interplay between attractive Van der Waals dispersion forces leading to weak attractive C...Ti and repulsive C...Ob interactions which lead to large barriers of 50-70kJmol-1 for the rotation of the octoxy alkyl chains across the Ob rows. In the presence of the germinal hydroxyl groups we find that the relative populations of the various conformations as well as the rotational barriers are perturbed by the presence of geminate hydroxyl due to additional C...hydroxyl repulsions.

  15. Rotationally sampled wind characteristics and correlations with MOD-OA wind turbine response

    SciTech Connect (OSTI)

    George, R.L.; Connell, J.R.

    1984-09-01

    This report presents results of a comprehensive wind and wind turbine measurement program: the Clayton, New Mexico, vertical plane array/MOD-OA project. In this experiment, the turbulent wind was measured for a large array of fixed anemometers located two blade diameters upwind of a 200-kW horizontal-axis wind turbine (HAWT). Simultaneously, key wind turbine response parameters were also measured. The first of two major objectives of this experiment was to determine the turbulent wind, rotationally sampled to emulate the motion of the wind turbine blade, for the range of different wind speeds and stability classes actually experienced by the wind turbine. The second major objective was to correlate this rotationally sampled wind with the wind turbine blade stress and power, in order to assess the usefulness of the wind measurements for wind turbine loads testing a prediction. Time series of rotationally sampled winds and wind turbine blade bending moments and power were converted to frequency spectra using Fourier transform techniques. These spectra were used as the basis for both qualitative and quantitative comparisons among the various cases. A quantitative comparison between the rotationally sampled wind input and blade bending response was made, using the Fourier spectra to estimate the blade transfer function. These transfer functions were then used to calculate an approximate damping coefficient for the MOD-OA fiberglass blade.

  16. Simulation of winds as seen by a rotating vertical axis wind turbine blade

    SciTech Connect (OSTI)

    George, R.L.

    1984-02-01

    The objective of this report is to provide turbulent wind analyses relevant to the design and testing of Vertical Axis Wind Turbines (VAWT). A technique was developed for utilizing high-speed turbulence wind data from a line of seven anemometers at a single level to simulate the wind seen by a rotating VAWT blade. Twelve data cases, representing a range of wind speeds and stability classes, were selected from the large volume of data available from the Clayton, New Mexico, Vertical Plane Array (VPA) project. Simulations were run of the rotationally sampled wind speed relative to the earth, as well as the tangential and radial wind speeds, which are relative to the rotating wind turbine blade. Spectral analysis is used to compare and assess wind simulations from the different wind regimes, as well as from alternate wind measurement techniques. The variance in the wind speed at frequencies at or above the blade rotation rate is computed for all cases, and is used to quantitatively compare the VAWT simulations with Horizontal Axis Wind Turbine (HAWT) simulations. Qualitative comparisons are also made with direct wind measurements from a VAWT blade.

  17. Testing neoclassical and turbulent effects on poloidal rotation in the core of DIII-D

    SciTech Connect (OSTI)

    Chrystal, C.; Burrell, K. H.; Staebler, G. M.; Kinsey, J. E.; Lao, L. L.; Grassie, J. S. de; Grierson, B. A.; Solomon, W. M.; Wang, W. X.; Rhodes, T. L.; Schmitz, L.; Mordijck, S.; Meneghini, O.

    2014-07-15

    Experimental tests of ion poloidal rotation theories have been performed on DIII-D using a novel impurity poloidal rotation diagnostic. These tests show significant disagreements with theoretical predictions in various conditions, including L-mode plasmas with internal transport barriers (ITB), H-mode plasmas, and QH-mode plasmas. The theories tested include standard neoclassical theory, turbulence driven Reynolds stress, and fast-ion friction on the thermal ions. Poloidal rotation is observed to spin up at the formation of an ITB and makes a significant contribution to the measurement of the E{sup ?}B{sup ?} shear that forms the ITB. In ITB cases, neoclassical theory agrees quantitatively with the experimental measurements only in the steep gradient region. Significant quantitative disagreement with neoclassical predictions is seen in the cores of ITB, QH-, and H-mode plasmas, demonstrating that neoclassical theory is an incomplete description of poloidal rotation. The addition of turbulence driven Reynolds stress does not remedy this disagreement; linear stability calculations and Doppler backscattering measurements show that disagreement increases as turbulence levels decline. Furthermore, the effect of fast-ion friction, by itself, does not lead to improved agreement; in QH-mode plasmas, neoclassical predictions are closest to experimental results in plasmas with the largest fast ion friction. Predictions from a new model that combines all three effects show somewhat better agreement in the H-mode case, but discrepancies well outside the experimental error bars remain.

  18. Spinning like a blue straggler: the population of fast rotating blue straggler stars in ? Centauri

    SciTech Connect (OSTI)

    Mucciarelli, A.; Lovisi, L.; Ferraro, F. R.; Dalessandro, E.; Lanzoni, B.

    2014-12-10

    By using high-resolution spectra acquired with FLAMES-GIRAFFE at the ESO/VLT, we measured the radial and rotational velocities for 110 blue straggler stars (BSSs) in ? Centauri, the globular cluster-like stellar system harboring the largest known BSS population. According to their radial velocities, 109 BSSs are members of the system. The rotational velocity distribution is very broad, with the bulk of BSSs spinning at less than ?40 km s{sup 1} (in agreement with the majority of such stars observed in other globular clusters) and a long tail reaching ?200 km s{sup 1}. About 40% of the sample has v{sub e} sin i > 40 km s{sup 1} and about 20% has v{sub e} sin i > 70 km s{sup 1}. Such a large fraction is very similar to the percentage of fast rotating BSSs observed in M4. Thus, ? Centauri is the second stellar cluster, beyond M4, with a surprisingly high population of fast spinning BSSs. We found a hint of radial behavior for a fraction of fast rotating BSSs, with a mild peak within one core radius, and a possible rise in the external regions (beyond four core radii). This may suggest that recent formation episodes of mass transfer BSSs occurred preferentially in the outskirts of ? Centauri, or that braking mechanisms able to slow down these stars are least efficient in the lowest density environments.

  19. SIGNATURE OF DIFFERENTIAL ROTATION IN SUN-AS-A-STAR Ca II K MEASUREMENTS

    SciTech Connect (OSTI)

    Bertello, L.; Pietarila, A.; Pevtsov, A. A. E-mail: apietarila@nso.edu

    2012-12-10

    The characterization of solar surface differential rotation (SDR) from disk-integrated chromospheric measurements has important implications for the study of differential rotation and dynamo processes in other stars. Some chromospheric lines, such as Ca II K, are very sensitive to the presence of activity on the disk and are an ideal choice for investigating SDR in Sun-as-a-star observations. Past studies indicate that when the activity is low, the determination of Sun's differential rotation from integrated-sunlight measurements becomes uncertain. However, our study shows that using the proper technique, SDR can be detected from these type of measurements even during periods of extended solar minima. This paper describes results from the analysis of the temporal variations of Ca II K line profiles observed by the Integrated Sunlight Spectrometer during the declining phase of Cycle 23 and the rising phase of Cycle 24, and discusses the signature of SDR in the power spectra computed from time series of parameters derived from these profiles. The methodology described is quite general, and could be applied to photometric time series of other main-sequence stars for detecting differential rotation.

  20. Bulk scalar emission from a rotating black hole pierced by a tense brane

    SciTech Connect (OSTI)

    Kobayashi, Tsutomu; Nozawa, Masato; Takamizu, Yu-ichi

    2008-02-15

    We study the emission of scalar fields into the bulk from a six-dimensional rotating black hole pierced by a 3-brane. We determine the angular eigenvalues in the presence of finite brane tension by using the continued fraction method. The radial equation is integrated numerically, giving the absorption probability (graybody factor) in a wider frequency range than in the preexisting literature. We then compute the power and angular momentum emission spectra for different values of the rotation parameter and brane tension, and compare their relative behavior in detail. As is expected from the earlier result for a nonrotating black hole, the finite brane tension suppresses the emission rates. As the rotation parameter increases, the power spectra are reduced at low frequencies due to the smaller Hawking temperature and are enhanced at high frequencies due to superradiance. The angular momentum spectra are enhanced over the whole frequency range as the rotation parameter increases. The spectra and the amounts of energy and angular momentum radiated away into the bulk are thus determined by the interplay of these effects.

  1. SOLAR MAGNETIZED TORNADOES: ROTATIONAL MOTION IN A TORNADO-LIKE PROMINENCE

    SciTech Connect (OSTI)

    Su, Yang; Veronig, Astrid; Temmer, Manuela; Vanninathan, Kamalam; Gmry, Peter; Wang, Tongjiang; Gan, Weiqun; Li, YouPing

    2014-04-10

    Su et al. proposed a new explanation for filament formation and eruption, where filament barbs are rotating magnetic structures driven by underlying vortices on the surface. Such structures have been noticed as tornado-like prominences when they appear above the limb. They may play a key role as the source of plasma and twist in filaments. However, no observations have successfully distinguished rotational motion of the magnetic structures in tornado-like prominences from other motions such as oscillation and counter-streaming plasma flows. Here we report evidence of rotational motions in a tornado-like prominence. The spectroscopic observations in two coronal lines were obtained from a specifically designed Hinode/EIS observing program. The data revealed the existence of both cold and million-degree-hot plasma in the prominence leg, supporting the so-called prominence-corona transition region. The opposite velocities at the two sides of the prominence and their persistent time evolution, together with the periodic motions evident in SDO/AIA dark structures, indicate a rotational motion of both cold and hot plasma with a speed of ?5kms{sup 1}.

  2. ANALYSIS OF THE SIMULTANEOUS ROTATION AND NON-RADIAL PROPAGATION OF AN ERUPTIVE FILAMENT

    SciTech Connect (OSTI)

    Bi Yi; Jiang Yunchun; Yang Jiayan; Zheng Ruisheng; Hong Junchao; Li Haidong; Yang Dan; Yang Bo

    2013-08-20

    The rotation of eruptive filaments is not only related to the kink instability occurring in the solar corona but also may result from the interaction between the large-scale magnetic field and the eruptions themselves. This interaction could likewise make the filament deflect in the radial direction. By means of data obtained by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory and observations from the Solar Terrestrial Relations Observatory, we study an eruptive filament showing both rotation and non-radial motion. The consequence of the three-dimensional reconstruction of the filament axis indicates that a significant rotation was simultaneous with the severe deflection in the latitude during the eruption. In combination with the results of a derived coronal magnetic configuration, our observations suggested that the non-radial motion resulted from the interaction between the eruption and an overlying pseudostreamer. Moreover, we find that the deflection of the eruption is asymmetric, with its eastern segment being dragged more significantly than its western one. Therefore, we suggested that the action of the asymmetric deflection is possibly an alternative mechanism for the rotation of the eruptive filament.

  3. Comparisons of characteristic timescales and approximate models for Brownian magnetic nanoparticle rotations

    SciTech Connect (OSTI)

    Reeves, Daniel B. Weaver, John B.

    2015-06-21

    Magnetic nanoparticles are promising tools for a host of therapeutic and diagnostic medical applications. The dynamics of rotating magnetic nanoparticles in applied magnetic fields depend strongly on the type and strength of the field applied. There are two possible rotation mechanisms and the decision for the dominant mechanism is often made by comparing the equilibrium relaxation times. This is a problem when particles are driven with high-amplitude fields because they are not necessarily at equilibrium at all. Instead, it is more appropriate to consider the “characteristic timescales” that arise in various applied fields. Approximate forms for the characteristic time of Brownian particle rotations do exist and we show agreement between several analytical and phenomenological-fit models to simulated data from a stochastic Langevin equation approach. We also compare several approximate models with solutions of the Fokker-Planck equation to determine their range of validity for general fields and relaxation times. The effective field model is an excellent approximation, while the linear response solution is only useful for very low fields and frequencies for realistic Brownian particle rotations.

  4. Rotating biological contactors: Wastewater treatment. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect (OSTI)

    1995-10-01

    The bibliography contains citations concerning wastewater treatment using rotating biological contactors (RBC). Citations focus on reaction kinetics, operational modeling, and removal efficiencies. Biological oxygen demand (BOD) and nitrogen removal are discussed. Citations examine performance of RBCs in industrial and municipal applications. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  5. The Study of High Spin States in Nuclear Rotation by the Cranked Nilsson Strutinsky Model

    SciTech Connect (OSTI)

    Kardan, A.; Miri-Hakimabad, H.; Rafat-Motevalli, L.

    2010-11-24

    A heavy-ion reaction can populate nuclear states of very high angular momentum with values of the order of I = 60 achievable. The reaction produces such configurations with a considerable internal excitation, but the emission of a few neutrons reduces the excitation energy effectively while not decreasing the spin by much. At sufficiently high spin the pairing is destroyed completely and the rigid-body moment of inertia becomes a good approximation. Even in this regime, however, the single-particle structure remains important and shell effects can be studied in terms of a rotating phenomenological shell model. On the theoretical side the cranked Nilsson strutinsky model has proved to be a successful tool to describe rapidly rotating nucleus. Indeed, this model gives a microscopic description of the influence of rotation on single-particle motion. This paper will concentrate on introduction to the cranked Nilsson strutinsky model in details. First, we explain the cranking model and the rotating liquid-drop model, then introduce the shell correction method. Also, we describe terminating bands, which show a continuous transition from high collectivity to a pure particle-hole state.

  6. A NEW LARGE SUPER-FAST ROTATOR: (335433) 2005 UW163

    SciTech Connect (OSTI)

    Chang, Chan-Kao; Lin, Hsing-Wen; Ip, Wing-Huen; Waszczak, Adam; Prince, Thomas A.; Kulkarni, Shrinivas R.; Laher, Russ; Surace, Jason

    2014-08-20

    Asteroids of size larger than 150m generally do not have rotation periods smaller than 2.2 hr. This spin cutoff is believed to be due to the gravitationally bound rubble-pile structures of the asteroids. Rotation with periods exceeding this critical value will cause asteroid breakup. Up until now, only one object, 2001 OE84, has been found to be an exception to this spin cutoff. We report the discovery of a new super-fast rotator, (335433) 2005 UW163, spinning with a period of 1.290 hr and a light curve variation of r' ? 0.8mag from the observations made at the P48 telescope and the P200 telescope of the Palomar Observatory. Its H{sub r{sup ?}}=17.690.27mag and multi-band colors (i.e., g' r' = 0.68 0.03mag, r' i' = 0.19 0.02mag and SDSS i z = 0.45mag) show it is a V-type asteroid with a diameter of 0.6 + 0.3/ 0.2 km. This indicates (335433) 2005 UW163 is a super-fast rotator beyond the regime of the small monolithic asteroid.

  7. DOES MAGNETIC-FIELD-ROTATION MISALIGNMENT SOLVE THE MAGNETIC BRAKING CATASTROPHE IN PROTOSTELLAR DISK FORMATION?

    SciTech Connect (OSTI)

    Li Zhiyun [Astronomy Department, University of Virginia, Charlottesville, VA (United States); Krasnopolsky, Ruben; Shang, Hsien [Academia Sinica, Theoretical Institute for Advanced Research in Astrophysics, Taipei, Taiwan (China)

    2013-09-01

    Stars form in dense cores of molecular clouds that are observed to be significantly magnetized. In the simplest case of a laminar (non-turbulent) core with the magnetic field aligned with the rotation axis, both analytic considerations and numerical simulations have shown that the formation of a large, 10{sup 2} AU scale, rotationally supported protostellar disk is suppressed by magnetic braking in the ideal MHD limit for a realistic level of core magnetization. This theoretical difficulty in forming protostellar disks is termed the ''magnetic braking catastrophe''. A possible resolution to this problem, proposed by Hennebelle and Ciardi and Joos et al., is that misalignment between the magnetic field and rotation axis may weaken the magnetic braking enough to enable disk formation. We evaluate this possibility quantitatively through numerical simulations. We confirm the basic result of Joos et al. that the misalignment is indeed conducive to disk formation. In relatively weakly magnetized cores with dimensionless mass-to-flux ratio {approx}> 4, it enabled the formation of rotationally supported disks that would otherwise be suppressed if the magnetic field and rotation axis are aligned. For more strongly magnetized cores, disk formation remains suppressed, however, even for the maximum tilt angle of 90 Degree-Sign . If dense cores are as strongly magnetized as indicated by OH Zeeman observations (with a mean dimensionless mass-to-flux ratio {approx}2), it would be difficult for the misalignment alone to enable disk formation in the majority of them. We conclude that, while beneficial to disk formation, especially for the relatively weak field case, misalignment does not completely solve the problem of catastrophic magnetic braking in general.

  8. Near-infrared structure of fast and slow-rotating disk galaxies

    SciTech Connect (OSTI)

    Schechtman-Rook, Andrew; Bershady, Matthew A.

    2014-11-10

    We investigate the stellar disk structure of six nearby edge-on spiral galaxies using high-resolution JHK {sub s}-band images and three-dimensional radiative transfer models. To explore how mass and environment shape spiral disks, we selected galaxies with rotational velocities between 69 km s{sup 1} rotating (V {sub rot} > 150 km s{sup 1}) galaxies, only NGC 4013 has the super-thin+thin+thick nested disk structure seen in NGC 891 and the Milky Way, albeit with decreased oblateness, while NGC 1055, a disturbed massive spiral galaxy, contains disks with h{sub z} ? 200 pc. NGC 4565, another fast-rotator, contains a prominent ring at a radius ?5 kpc but no super-thin disk. Despite these differences, all fast-rotating galaxies in our sample have inner truncations in at least one of their disks. These truncations lead to Freeman Type II profiles when projected face-on. Slow-rotating galaxies are less complex, lacking inner disk truncations and requiring fewer disk components to reproduce their light distributions. Super-thin disk components in undisturbed disks contribute ?25% of the total K {sub s}-band light, up to that of the thin-disk contribution. The presence of super-thin disks correlates with infrared flux ratios; galaxies with super-thin disks have f{sub K{sub s}}/f{sub 60} {sub ?m}?0.12 for integrated light, consistent with super-thin disks being regions of ongoing star-formation. Attenuation-corrected vertical color gradients in (J K {sub s}) correlate with the observed disk structure and are consistent with population gradients with young-to-intermediate ages closer to the mid-plane, indicating that disk heatingor coolingis a ubiquitous phenomenon.

  9. Measurements of coronal Faraday rotation at 4.6 R {sub ?}

    SciTech Connect (OSTI)

    Kooi, Jason E.; Fischer, Patrick D.; Buffo, Jacob J.; Spangler, Steven R.

    2014-03-20

    Many competing models for the coronal heating and acceleration mechanisms of the high-speed solar wind depend on the solar magnetic field and plasma structure in the corona within heliocentric distances of 5 R {sub ?}. We report on sensitive Very Large Array (VLA) full-polarization observations made in 2011 August, at 5.0 and 6.1 GHz (each with a bandwidth of 128 MHz) of the radio galaxy 3C 228 through the solar corona at heliocentric distances of 4.6-5.0 R {sub ?}. Observations at 5.0 GHz permit measurements deeper in the corona than previous VLA observations at 1.4 and 1.7 GHz. These Faraday rotation observations provide unique information on the magnetic field in this region of the corona. The measured Faraday rotation on this day was lower than our a priori expectations, but we have successfully modeled the measurement in terms of observed properties of the corona on the day of observation. Our data on 3C 228 provide two lines of sight (separated by 46'', 33,000 km in the corona). We detected three periods during which there appeared to be a difference in the Faraday rotation measure between these two closely spaced lines of sight. These measurements (termed differential Faraday rotation) yield an estimate of 2.6-4.1 GA for coronal currents. Our data also allow us to impose upper limits on rotation measure fluctuations caused by coronal waves; the observed upper limits were 3.3 and 6.4 rad m{sup 2} along the two lines of sight. The implications of these results for Joule heating and wave heating are briefly discussed.

  10. Measurements of isocenter path characteristics of the gantry rotation axis with a smartphone application

    SciTech Connect (OSTI)

    Schiefer, H. Peters, S.; Plasswilm, L.; Ingulfsen, N.; Kluckert, J.

    2015-03-15

    Purpose: For stereotactic radiosurgery, the AAPM Report No. 54 [AAPM Task Group 42 (AAPM, 1995)] requires the overall stability of the isocenter (couch, gantry, and collimator) to be within a 1 mm radius. In reality, a rotating system has no rigid axis and thus no isocenter point which is fixed in space. As a consequence, the isocenter concept is reviewed here. It is the aim to develop a measurement method following the revised definitions. Methods: The mechanical isocenter is defined here by the point which rotates on the shortest path in the room coordinate system. The path is labeled as “isocenter path.” Its center of gravity is assumed to be the mechanical isocenter. Following this definition, an image-based and radiation-free measurement method was developed. Multiple marker pairs in a plane perpendicular to the assumed gantry rotation axis of a linear accelerator are imaged with a smartphone application from several rotation angles. Each marker pair represents an independent measuring system. The room coordinates of the isocenter path and the mechanical isocenter are calculated based on the marker coordinates. The presented measurement method is by this means strictly focused on the mechanical isocenter. Results: The measurement result is available virtually immediately following completion of measurement. When 12 independent measurement systems are evaluated, the standard deviations of the isocenter path points and mechanical isocenter coordinates are 0.02 and 0.002 mm, respectively. Conclusions: The measurement is highly accurate, time efficient, and simple to adapt. It is therefore suitable for regular checks of the mechanical isocenter characteristics of the gantry and collimator rotation axis. When the isocenter path is reproducible and its extent is in the range of the needed geometrical accuracy, it should be taken into account in the planning process. This is especially true for stereotactic treatments and radiosurgery.

  11. Comparison of 180-degree and 90-degree needle rotation to reduce wound size in PIT-injected juvenile Chinook salmon

    SciTech Connect (OSTI)

    Bryson, Amanda J.; Woodley, Christa M.; Karls, Rhonda K.; Hall, Kathleen D.; Weiland, Mark A.; Deng, Zhiqun; Carlson, Thomas J.; Eppard, Matthew B.

    2013-04-30

    Animal telemetry, which requires the implantation of passive transponders or active transmitters, is used to monitor and assess fish stock and conservation to gain an understanding of fish movement and behavior. As new telemetry technologies become available, studies of their effects on species of interest are imperative as is development of implantation techniques. In this study, we investigated the effects of bevel rotation (0-, 90-, 180-degree axis rotation) on wound extent, tag loss, and wound healing rates in juvenile Chinook salmon injected with an 8-gauge needle, which is required for implantation of the novel injectable Juvenile Salmon Acoustic Telemetry Systems (JSATS) acoustic transmitter or large passive integrated transponder (PIT) tags. Although the injection sites were not closed after injection (e.g., with sutures or glue), there were no mortalities, dropped tags, or indications of fungus, ulceration, and/or redness around the wound. On Day 0 and post-implantation Day 7, the 90-degree bevel rotation produced smaller wound extent than the 180-degree bevel rotation. No axis rotation (0-degrees) resulted in the PIT tag frequently misleading or falling out upon injection. The results of this study indicated the 90-degree bevel rotation was the more efficient technique, produced less wound extent. Given the wound extent compared to size of fish, we recommend researchers should consider a 90-degree rotation over the 180-degree rotation in telemetry studies. Highlights •Three degrees of needle rotation were examined for effects in Chinook salmon. •Mortality, tag loss, wound extent, healing, and infection indicators were measured. •There were no mortalities, tag loss, or indications of infection. •The 90-degree needle rotation through Day 7 produced the smallest wound extent.

  12. Modeling dynamic stall on wind turbine blades under rotationally augmented flow fields

    SciTech Connect (OSTI)

    Guntur, S.; Schreck, S.; Sorensen, N. N.; Bergami, L.

    2015-04-22

    It is well known that airfoils under unsteady flow conditions with a periodically varying angle of attack exhibit aerodynamic characteristics different from those under steady flow conditions, a phenomenon commonly known as dynamic stall. It is also well known that the steady aerodynamic characteristics of airfoils in the inboard region of a rotating blade differ from those under steady two-dimensional (2D) flow conditions, a phenomenon commonly known as rotational augmentation. This paper presents an investigation of these two phenomena together in the inboard parts of wind turbine blades. This analysis is carried out using data from three sources: (1) the National Renewable Energy Laboratory’s Unsteady Aerodynamics Experiment Phase VI experimental data, including constant as well as continuously pitching blade conditions during axial operation, (2) data from unsteady Delayed Detached Eddy Simulations (DDES) carried out using the Technical University of Denmark’s in-house flow solver Ellipsys3D, and (3) data from a simplified model based on the blade element momentum method with a dynamic stall subroutine that uses rotationally augmented steady-state polars obtained from steady Phase VI experimental sequences, instead of the traditional 2D nonrotating data. The aim of this work is twofold. First, the blade loads estimated by the DDES simulations are compared to three select cases of the N sequence experimental data, which serves as a validation of the DDES method. Results show reasonable agreement between the two data in two out of three cases studied. Second, the dynamic time series of the lift and the moment polars obtained from the experiments are compared to those from the dynamic stall subroutine that uses the rotationally augmented steady polars. This allowed the differences between the stall phenomenon on the inboard parts of harmonically pitching blades on a rotating wind turbine and the classic dynamic stall representation in 2D flow to be

  13. Transient stability enhancement of electric power generating systems by 120-degree phase rotation

    DOE Patents [OSTI]

    Cresap, Richard L.; Taylor, Carson W.; Kreipe, Michael J.

    1982-01-01

    A method and system for enhancing the transient stability of an intertied three-phase electric power generating system. A set of power exporting generators (10) is connected to a set of power importing generators (20). When a transient cannot be controlled by conventional stability controls, and imminent loss of synchronism is detected (such as when the equivalent rotor angle difference between the two generator sets exceeds a predetermined value, such as 150 degrees), the intertie is disconnected by circuit breakers. Then a switch (30) having a 120-degree phase rotation, or a circuit breaker having a 120-degree phase rotation is placed in the intertie. The intertie is then reconnected. This results in a 120-degree reduction in the equivalent rotor angle difference between the two generator sets, making the system more stable and allowing more time for the conventional controls to stabilize the transient.

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

    DOE Patents [OSTI]

    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.

  15. Deformed rotational cascades in {sup 152}Dy: Further evidence for shape coexistence at high spin

    SciTech Connect (OSTI)

    Smith, M. B.; Department of Electronic Engineering and Physics, University of Paisley, Paisley PA1 2BE, ; Appelbe, D. E.; Twin, P. J.; Beausang, C. W.; Wright Nuclear Structure Laboratory, Yale University, 272 Whitney Avenue, New Haven, Connecticut 06520 ; Beck, F. A.; Bentley, M. A.; Cullen, D. M.; Curien, D.; Dagnall, P. J.; De France, G.

    2000-03-01

    Two new rotational bands have been observed in the {sup 152}Dy nucleus following experiments performed using the EUROGAM {gamma}-ray spectrometer. Several transitions have been observed that link these new bands into the known single-particle states. Using the Doppler shift attenuation method, the quadrupole moment of the previously-known rotational sequence has been measured. The value of Q{sub band}=3.85{+-}0.06 e b confirms the deformed nature of this cascade. The structures of the three bands are discussed in terms of the occupation of both paired and unpaired orbitals, and are found to be in good agreement with theoretical calculations. The observation of two new bands further extends the concept of shape coexistence in the {sup 152}Dy nucleus. (c) 2000 The American Physical Society.

  16. Electrochemical study of uranium cations in LiCl-KCl melt using a rotating disk electrode

    SciTech Connect (OSTI)

    Bae, Sang-Eun; Kim, Dae-Hyun; Kim, Jong-Yoon; Park, Tae-Hong; Cho, Young Hwan; Yeon, Jei-Won; Song, Kyuseok

    2013-07-01

    A rotating disk electrode (RDE) measurement technique was employed to investigate the electrochemical REDOX reactions of actinide (An) and lanthanide (Ln) ions in LiCl-KCl molten salt. By using RDE, it is possible to access more exact values of the diffusion coefficient, Tafel slope, and exchange current density. In this work, we constructed RDE setup and electrodes for RDE measurements in high temperature molten salt and measured the electrochemical parameters of the An and Ln ions. The RDE setup is composed of a Pine model MSRX rotator equipped with a rod type of W electrode. The active electrode area was confined to the planar part of the W rod by making meniscus at the LiCl-KCl melt surface.

  17. Early F-type stars - refined classification, confrontation with Stromgren photometry, and the effects of rotation

    SciTech Connect (OSTI)

    Gray, R.O.; Garrison, R.F.

    1989-02-01

    The classification for early F-type stars in the MK spectral classification system presented by Gray and Garrison (1987) is refined. The effect of rotation on spectral classification and ubvy-beta photometry of early F-type stars is examined. It is found that the classical luminosity criterion, the 4417 A/4481 A ratio gives inconsistent results. It is shown that most of the stars in the Delta Delphini class of metallic-line stars are either normal or are indistinguishable from proto-Am stars. It is suggested that the designation Delta Delphini should be dropped. The classifications are compared with Stromgren photometry. The effects of rotation on the delta-c sub 1 index in the early-F field dwarfs is demonstrated. 55 references.

  18. AmeriFlux US-Ne2 Mead - irrigated maize-soybean rotation site

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Suyker, Andy [University of Nebraska - Lincoln

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Ne2 Mead - irrigated maize-soybean rotation site. Site Description - The study site is one of three fields (all located within 1.6 km of each other) at the University of Nebraska Agricultural Research and Development Center near Mead, Nebraska. This site is irrigated with a center pivot system. Prior to the initiation of the study, the irrigated site had a 10-yr history of maize-soybean rotation under no-till. A tillage operation (disking) was done just prior to the 2001 planting to homogenize the top 0.1 m of soil, incorporate P and K fertilizers, as well as previously accumulated surface residues. Since this tillage operation, the site has been under no-till management.

  19. Test of the Isotropy of the Speed of Light Using a Continuously Rotating Optical Resonator

    SciTech Connect (OSTI)

    Herrmann, Sven; Senger, Alexander; Peters, Achim; Kovalchuk, Evgeny; Mueller, Holger

    2005-10-07

    We report on a test of Lorentz invariance performed by comparing the resonance frequencies of one stationary optical resonator and one continuously rotating on a precision air bearing turntable. Special attention is paid to the control of rotation induced systematic effects. Within the photon sector of the standard model extension, we obtain improved limits on combinations of 8 parameters at a level of a few parts in 10{sup -16}. For the previously least well known parameter we find {kappa}-tilde{sub e-}{sup ZZ}=(-1.9{+-}5.2)x10{sup -15}. Within the Robertson-Mansouri-Sexl test theory, our measurement restricts the isotropy violation parameter {beta}-{delta}-(1/2) to (-2.1{+-}1.9)x10{sup -10}, corresponding to an eightfold improvement with respect to previous nonrotating measurements.

  20. Optimal ancilla-free Pauli+V circuits for axial rotations

    SciTech Connect (OSTI)

    Blass, Andreas; Bocharov, Alex; Gurevich, Yuri

    2015-12-15

    We address the problem of optimal representation of single-qubit rotations in a certain unitary basis consisting of the so-called V gates and Pauli matrices. The V matrices were proposed by Lubotsky, Philips, and Sarnak [Commun. Pure Appl. Math. 40, 401–420 (1987)] as a purely geometric construct in 1987 and recently found applications in quantum computation. They allow for exceptionally simple quantum circuit synthesis algorithms based on quaternionic factorization. We adapt the deterministic-search technique initially proposed by Ross and Selinger to synthesize approximating Pauli+V circuits of optimal depth for single-qubit axial rotations. Our synthesis procedure based on simple SL{sub 2}(ℤ) geometry is almost elementary.

  1. Continuum resonance induced electromagnetic torque by a rotating plasma response to static resonant magnetic perturbation field

    SciTech Connect (OSTI)

    Liu Yueqiang; Connor, J. W.; Cowley, S. C.; Ham, C. J.; Hastie, R. J.; Hender, T. C.

    2012-10-15

    A numerical study is carried out, based on a simple toroidal tokamak equilibrium, to demonstrate the radial re-distribution of the electromagnetic torque density, as a result of a rotating resistive plasma (linear) response to a static resonant magnetic perturbation field. The computed electromagnetic torque peaks at several radial locations even in the presence of a single rational surface, due to resonances between the rotating response, in the plasma frame, and both Alfven and sound continuum waves. These peaks tend to merge together to form a rather global torque distribution, when the plasma resistivity is large. The continuum resonance induced net electromagnetic torque remains finite even in the limit of an ideal plasma.

  2. A steady state field-reversed configuration with rotating magnetic fields

    SciTech Connect (OSTI)

    Ohnishi, Masami; Yamamoto, Yasushi; Yoshikawa, Kiyoshi; Kitagaki, Jiro; Ishida, Akio

    1995-12-31

    The numerical simulations were made on current sustainment of a field-reversed configuration (FRC) by a rotating magnetic field (RMF). The RMF externally applied just after producing the FRC by a theta pinch discharge is found to penetrate rapidly into the FRC, and to drive a steady current before the FRC collapses due to Joule dissipation. The minimum rotating magnetic field to sustain the equilibrium is also found to be as small as 10% of the axial magnetic field. The RMF`s with the mode number of m = 1 or 2 are found to provide the similar effects. The numerical results show that the method of applying an RMF to an FRC is considerably effective for sustaining the hot and dense FRC in the steady state.

  3. Hall magnetohydrodynamics simulations of end-shorting induced rotation in field-reversed configurations

    SciTech Connect (OSTI)

    Macnab, A. I. D.; Milroy, R. D.; Kim, C. C.; Sovinec, C. R.

    2007-09-15

    End-shorting of the open field lines that surround a field-reversed configuration (FRC) is believed to contribute to its observed rotation. In this study, nonlinear extended magnetohydrodynamics (MHD) simulations were performed that detail the end-shorting process and the resulting spin-up of the FRC. The tangential component of the electric field E{sub T} is set to zero at the axial boundaries in an extended MHD model that includes the Hall and {nabla}P{sub e} terms. This shorting of the electric field leads to the generation of toroidal fields on the open field lines, which apply a torque leading to a rotation of the ions on the open field lines. The FRC then gains angular momentum through a viscous transfer from the open field line region. In addition, it is shown that spin-up is still induced when insulating boundaries are assumed.

  4. Upper bound on parity-violating neutron spin rotation in {sup 4}He

    SciTech Connect (OSTI)

    Snow, W. M.; Luo, D.; Walbridge, S. B.; Crawford, B. E.; Gan, K.; Micherdzinska, A. M.; Opper, A. K.; Heckel, B. R.; Swanson, H. E.; Sharapov, E. I.; Zhumabekova, V.

    2011-02-15

    We report an upper bound on parity-violating neutron spin rotation in {sup 4}He. This experiment is the most sensitive search for neutron-weak optical activity yet performed and represents a significant advance in precision in comparison to past measurements in heavy nuclei. The experiment was performed at the NG-6 slow-neutron beamline at the National Institute of Standards and Technology (NIST) Center for Neutron Research. Our result for the neutron spin rotation angle per unit length in {sup 4}He is d{phi}/dz=[+1.7{+-}9.1(stat.){+-}1.4(sys.)]x10{sup -7} rad/m. The statistical uncertainty is smaller than current estimates of the range of possible values of d{phi}/dz in n+{sup 4}He.

  5. Spectroscopic investigation of the vibrational quasi-continuum arising from internal rotation of a methyl group

    SciTech Connect (OSTI)

    Hougen, J.T.

    1993-12-01

    The goal of this project is to use spectroscopic techniques to investigate in detail phenomena involving the vibrational quasi-continuum in a simple physical system. Acetaldehyde was chosen for the study because: (i) methyl groups have been suggested to be important promotors of intramolecular vibrational relaxation, (ii) the internal rotation of a methyl group is an easily describle large-amplitude motion, which should retain its simple character even at high levels of excitation, and (iii) the aldehyde carbonyl group offers the possibility of both vibrational and electronic probing. The present investigation of the ground electronic state has three parts: (1) understanding the {open_quotes}isolated{close_quotes} internal-rotation motion below, at, and above the top of the torsional barrier, (2) understanding in detail traditional (bond stretching and bending) vibrational fundamental and overtone states, and (3) understanding interactions involving states with multiquantum excitations of at least one of these two kinds of motion.

  6. Semiconductor sensor for optically measuring polarization rotation of optical wavefronts using rare earth iron garnets

    DOE Patents [OSTI]

    Duncan, Paul G.

    2002-01-01

    Described are the design of a rare earth iron garnet sensor element, optical methods of interrogating the sensor element, methods of coupling the optical sensor element to a waveguide, and an optical and electrical processing system for monitoring the polarization rotation of a linearly polarized wavefront undergoing external modulation due to magnetic field or electrical current fluctuation. The sensor element uses the Faraday effect, an intrinsic property of certain rare-earth iron garnet materials, to rotate the polarization state of light in the presence of a magnetic field. The sensor element may be coated with a thin-film mirror to effectively double the optical path length, providing twice the sensitivity for a given field strength or temperature change. A semiconductor sensor system using a rare earth iron garnet sensor element is described.

  7. In Situ Real-Time Radiographic Study of Thin Film Formation Inside Rotating Hollow Spheres

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Braun, Tom; Walton, Christopher C.; Dawedeit, Christoph; Biener, Monika M.; Kim, Sung Ho; Willey, Trevor M.; Xiao, Xianghui; van Buuren, Anthony; Hamza, Alex V.; Biener, Juergen

    2016-02-03

    The hollow spheres with uniform coatings on the inner surface have applications in optical devices, time- or site-controlled drug release, heat storage devices, and target fabrication for inertial confinement fusion experiments. The fabrication of uniform coatings, which is often critical for the application performance, requires precise understanding and control over the coating process and its parameters. We report on in situ real-time radiography experiments that provide critical spatiotemporal information about the distribution of fluids inside hollow spheres during uniaxial rotation. Furthermore, image analysis and computer fluid dynamics simulations were used to explore the effect of liquid viscosity and rotational velocitymore » on the film uniformity. The data were then used to demonstrate the fabrication of uniform sol–gel chemistry derived porous polymer films inside 2 mm inner diameter diamond shells.« less

  8. Study of Quantum Chaos in the Framework of Triaxial Rotator Models

    SciTech Connect (OSTI)

    Proskurins, J.; Bavrins, K.; Andrejevs, A.; Krasta, T.; Tambergs, J. [Institute of Solid State Physics, University of Latvia, LV-1063, Riga (Latvia)

    2009-01-28

    Dynamical quantum chaos criteria--a perturbed wave function entropy W({psi}{sub i}) and a fragmentation width {kappa}({phi}{sub k}) of basis states were studied in two cases of nuclear rigid triaxial rotator models. The first model is characterized by deformation angle {gamma} only, while the second model depends on both quadrupole deformation parameters ({beta},{gamma}). The degree of chaoticity has been determined in the studies of the dependence of criteria W({psi}{sub i}) and {kappa}({phi}{sub k}) from nuclear spin values up to I{<=}101 for model parameters {gamma} and ({beta},{gamma}) correspondingly. The transition from librational to rotational type energy spectra has been considered for both models as well.

  9. Study of vaneless diffuser rotating stall based on two-dimensional inviscid flow analysis

    SciTech Connect (OSTI)

    Tsujimoto, Yoshinobu; Yoshida, Yoshiki [Osaka Univ., Toyonaka, Osaka (Japan); Mori, Yasumasa [Mitsubishi Motors Corp., Ohta, Tokyo (Japan)

    1996-03-01

    Rotating stalls in vaneless diffusers are studied from the viewpoint that they are basically two-dimensional inviscid flow instability under the boundary conditions of vanishing velocity disturbance at the diffuser inlet and of vanishing pressure disturbance at the diffuser outlet. The linear analysis in the present report shows that the critical flow angle and the propagation velocity are functions of only the diffuser radius ratio. It is shown that the present analysis can reproduce most of the general characteristics observed in experiments: critical flow angle, propagation velocity, velocity, and pressure disturbance fields. It is shown that the vanishing velocity disturbance at the diffuser inlet is caused by the nature of impellers as a resistance and an inertial resistance, which is generally strong enough to suppress the velocity disturbance at the diffuser inlet. This explains the general experimental observations that vaneless diffuser rotating stalls are not largely affected by the impeller.

  10. Simulation of non-resonant internal kink mode with toroidal rotation in the National Spherical Torus Experiment

    SciTech Connect (OSTI)

    Wang, Feng; Liu, J. Y. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Fu, G. Y.; Breslau, J. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Tritz, Kevin [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States)] [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

    2013-07-15

    Plasmas in spherical and conventional tokamaks, with weakly reversed shear q profile and minimum q above but close to unity, are susceptible to an non-resonant (m,n) = (1,1) internal kink mode. This mode can saturate and persist and can induce a (2,1) seed island for Neoclassical Tearing Mode. [Breslau et al. Nucl. Fusion 51, 063027 (2011)]. The mode can also lead to large energetic particle transport and significant broadening of beam-driven current. Motivated by these important effects, we have carried out extensive nonlinear simulations of the mode with finite toroidal rotation using parameters and profiles of an NTSX plasma with a weakly reversed shear profile. The numerical results show that, at the experimental level, plasma rotation has little effect on either equilibrium or linear stability. However, rotation can significantly influence the nonlinear dynamics of the (1,1) mode and the induced (2,1) magnetic island. The simulation results show that a rotating helical equilibrium is formed and maintained in the nonlinear phase at finite plasma rotation. In contrast, for non-rotating cases, the nonlinear evolution exhibits dynamic oscillations between a quasi-2D state and a helical state. Furthermore, the effects of rotation are found to greatly suppress the (2,1) magnetic island even at a low level.

  11. Rotational and radial velocities of 1.3-2.2 M {sub ☉} red giants in open clusters

    SciTech Connect (OSTI)

    Carlberg, Joleen K.

    2014-06-01

    This study presents the rotational distribution of red giant (RG) stars in 11 old to intermediate age open clusters. The masses of these stars are all above the Kraft break, so they lose negligible amounts of their birth angular momentum (AM) during the main-sequence (MS) evolution. However, they do span a mass range with quite different AM distributions imparted during formation, with the stars less massive than ∼1.6M {sub ☉} arriving on the MS with lower rotation rates than the more massive stars. The majority of RGs in this study are slow rotators across the entire red giant branch regardless of mass, supporting the picture that intermediate-mass stars rapidly spin down when they evolve off the MS and develop convection zones capable of driving a magnetic dynamo. Nevertheless, a small fraction of RGs in open clusters show some level of enhanced rotation, and faster rotators are as common in these clusters as in the field RG population. Most of these enhanced rotators appear to be red clump stars, which is also true of the underlying stellar sample, while others are clearly RGs that are above or below the clump. In addition to rotational velocities, the radial velocities (RVs) and membership probabilities of individual stars are also presented. Cluster heliocentric RVs for NGC 6005 and Pismis 18 are reported for the first time.

  12. Robotic real-time translational and rotational head motion correction during frameless stereotactic radiosurgery

    SciTech Connect (OSTI)

    Liu, Xinmin; Belcher, Andrew H.; Grelewicz, Zachary; Wiersma, Rodney D.

    2015-06-15

    Purpose: To develop a control system to correct both translational and rotational head motion deviations in real-time during frameless stereotactic radiosurgery (SRS). Methods: A novel feedback control with a feed-forward algorithm was utilized to correct for the coupling of translation and rotation present in serial kinematic robotic systems. Input parameters for the algorithm include the real-time 6DOF target position, the frame pitch pivot point to target distance constant, and the translational and angular Linac beam off (gating) tolerance constants for patient safety. Testing of the algorithm was done using a 4D (XY Z + pitch) robotic stage, an infrared head position sensing unit and a control computer. The measured head position signal was processed and a resulting command was sent to the interface of a four-axis motor controller, through which four stepper motors were driven to perform motion compensation. Results: The control of the translation of a brain target was decoupled with the control of the rotation. For a phantom study, the corrected position was within a translational displacement of 0.35 mm and a pitch displacement of 0.15° 100% of the time. For a volunteer study, the corrected position was within displacements of 0.4 mm and 0.2° over 98.5% of the time, while it was 10.7% without correction. Conclusions: The authors report a control design approach for both translational and rotational head motion correction. The experiments demonstrated that control performance of the 4D robotic stage meets the submillimeter and subdegree accuracy required by SRS.

  13. Short-rotation woody-crops program. Quarterly progress report for period ending May 31, 1981

    SciTech Connect (OSTI)

    Cushman, J.H.; Ranney, J.W.

    1982-04-01

    Progress of twenty projects in the Short Rotation Woody Crops Program is summarized for the period March 1 through May 31, 1981. Individual quarterly reports included from each of the projects discuss accomplishments within specific project objectives and identify recent papers and publications resulting from the research. The major project activities are species screening and genetic selection, stand establishment and cultural treatment, and harvest, collection, transportation, and storage.

  14. Evaluating the Impact of Head Rotation Amplification on Virtual Reality Training Effectiveness

    SciTech Connect (OSTI)

    Ragan, Eric D; Bowman, Doug A; Scerbo, Siroberto; Bacim, Felipe

    2013-01-01

    Virtual reality (VR) systems have been proposed for use in numerous training scenarios, such as room clearing, which require the trainee to maintain spatial awareness. But many VR training systems lack a fully surrounding display, requiring trainees to use a combination of physical and virtual turns to view the environment, thus decreasing spatial awareness. One solution to this problem is to amplify head rotations, such that smaller physical turns are mapped to larger virtual turns, allowing trainees to view the surrounding environment with head movements alone. For example, in a multi-monitor system covering only a 90-degree field of regard, head rotations could be amplified four times to allow the user to see the entire 360-degree surrounding environment. This solution is attractive because it can be used with lower-cost VR systems and does not require virtual turning. However, the effects of amplified head rotations on spatial awareness and training transfer are not well understood. We hypothesized that small amounts of amplification might be tolerable, but that larger amplifications might cause trainees to become disoriented and to have decreased task performance and training transfer. In this paper, we will present our findings from an experiment designed to investigate these hypotheses. The experiment placed users in a virtual warehouse and asked them to move from room to room, counting objects placed around them in space. We varied the amount of amplification applied during these trials, and also varied the type of display used (head-mounted display or CAVE). We measured task performance and spatial awareness. We then assessed training transfer in an assessment environment with a fully surrounding display and no amplification. The results of this study will inform VR training system developers about the potential negative effects of using head rotation amplification and contribute to more effective VR training system design.

  15. Electrodynamics of a rotating body; Relativistic theory of circular and axial birefringence

    SciTech Connect (OSTI)

    Evans, M.W. . Dept. of Physics)

    1992-09-20

    In this paper, the theory of the electrodynamics of a rotating body is used to show that there exists: circular birefringence purely relativistic origin, composed of dispersive aether drag and residual, ensemble averaged, magnetization; non-relativistic circular birefringence due to the angular velocity of the body in the observer frame; non-relativistic axial birefringence in chiral media due to the angular velocity of the body; second order, relativistic equivalents.

  16. Stud hardware with self-contained stud anti-rotation feature and method of installing studs

    DOE Patents [OSTI]

    Kartik, J.S.; Richardson, W.M.

    1984-03-14

    Disclosed herein is a method and apparatus for preventing the rotation of a stud member during preloading. The apparatus comprises a stud member having a shaft portion extending into the member to be clamped and a hex or double hex portion carrying a locking nut. Extending outward from the hex or double hex portion of the stud there is a threaded portion carrying a nut which is torqued to preload the stud

  17. Universality of the acceleration due to gravity on the surface of a rapidly rotating neutron star

    SciTech Connect (OSTI)

    AlGendy, Mohammad; Morsink, Sharon M.

    2014-08-20

    On the surface of a rapidly rotating neutron star, the effective centrifugal force decreases the effective acceleration due to gravity (as measured in the rotating frame) at the equator while increasing the acceleration at the poles due to the centrifugal flattening of the star into an oblate spheroid. We compute the effective gravitational acceleration for relativistic rapidly rotating neutron stars and show that for a star with mass M, equatorial radius R{sub e} , and angular velocity ?, the deviations of the effective acceleration due to gravity from the nonrotating case take on a universal form that depends only on the compactness ratio M/R{sub e} , the dimensionless square of the angular velocity ?{sup 2}R{sub e}{sup 3}/GM, and the latitude on the star's surface. This dependence is universal, in that it has very little dependence on the neutron star's equation of state. The effective gravity is expanded in the slow-rotation limit to show the dependence on the effective centrifugal force, oblate shape of the star, and the quadrupole moment of the gravitational field. In addition, an empirical fit and simple formula for the effective gravity is found. We find that the increase in the acceleration due to gravity at the poles is of the same order of magnitude as the decrease in the effective acceleration due to gravity at the equator for all realistic value of mass, radius, and spin. For neutron stars that spin with frequencies near 600 Hz, the difference between the effective gravity at the poles and the equator is about 20%.

  18. Deformation and shape transitions in hot rotating neutron deficient Te isotopes

    SciTech Connect (OSTI)

    Aggarwal, Mamta; Mazumdar, I.

    2009-08-15

    Evolution of the nuclear shapes and deformations under the influence of temperature and rotation is investigated in Te isotopes with neutron number ranging from the proton drip line to the stability valley. Spin dependent critical temperatures for the shape transitions in Te nuclei are computed. Shape transitions from prolate at low temperature and spin to oblate via triaxiality are seen with increasing neutron number and spin.

  19. Method and apparatus for reducing rotor blade deflections, loads, and/or peak rotational speed

    DOE Patents [OSTI]

    Moroz, Emilian Mieczyslaw; Pierce, Kirk Gee

    2006-10-17

    A method for reducing at least one of loads, deflections of rotor blades, or peak rotational speed of a wind turbine includes storing recent historical pitch related data, wind related data, or both. The stored recent historical data is analyzed to determine at least one of whether rapid pitching is occurring or whether wind speed decreases are occurring. A minimum pitch, a pitch rate limit, or both are imposed on pitch angle controls of the rotor blades conditioned upon results of the analysis.

  20. An argument for weakly magnetized, slowly rotating progenitors of long gamma-ray bursts

    SciTech Connect (OSTI)

    Moreno Méndez, Enrique

    2014-01-20

    Using binary evolution with Case-C mass transfer, the spins of several black holes (BHs) in X-ray binaries (XBs) have been predicted and confirmed (three cases) by observations. The rotational energy of these BHs is sufficient to power up long gamma-ray bursts (GRBs) and hypernovae (HNe) and still leave a Kerr BH behind. However, strong magnetic fields and/or dynamo effects in the interior of such stars deplete their cores from angular momentum preventing the formation of collapsars. Thus, even though binaries can produce Kerr BHs, most of their rotation is acquired from the stellar mantle, with a long delay between BH formation and spin up. Such binaries would not form GRBs. We study whether the conditions required to produce GRBs can be met by the progenitors of such BHs. Tidal-synchronization and Alfvén timescales are compared for magnetic fields of different intensities threading He stars. A search is made for a magnetic field range that allows tidal spin up all the way in to the stellar core but prevents its slow down during differential rotation phases. The energetics for producing a strong magnetic field during core collapse, which may allow for a GRB central engine, are also estimated. An observationally reasonable choice of parameters is found (B ≲ 10{sup 2} G threading a slowly rotating He star) that allows Fe cores to retain substantial angular momentum. Thus, the Case-C mass-transfer binary channel is capable of explaining long GRBs. However, the progenitors must have low initial spin and low internal magnetic field throughout their H-burning and He-burning phases.

  1. Apparatus for high flux photocatalytic pollution control using a rotating fluidized bed reactor

    DOE Patents [OSTI]

    Tabatabaie-Raissi, Ali; Muradov, Nazim Z.; Martin, Eric

    2003-06-24

    An apparatus based on optimizing photoprocess energetics by decoupling of the process energy efficiency from the DRE for target contaminants. The technique is applicable to both low- and high-flux photoreactor design and scale-up. An apparatus for high-flux photocatalytic pollution control is based on the implementation of multifunctional metal oxide aerogels and other media in conjunction with a novel rotating fluidized particle bed reactor.

  2. Testing Oxygen Reduction Reaction Activity with the Rotating Disc Electrode Technique

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Testing Oxygen Reduction Reaction Activity with the Rotating Disc Electrode Technique Date: Tuesday, March 12, 2013 Innovation for Our Energy Future Shyam S. Kocha: NREL Yannick Garsany: EXCET/NRL Deborah Myers: ANL https://www1.eere.energy.gov/hydrogenandfuelcells/webinars.html Outline 1) Background 2) Experimental Aspects of RDE Testing 3) Basic Measurement Technique & Analysis 4) Parameters Affecting RDE Activity Measurements 1) Impact of Film Deposition & Drying Techniques 2) Impact

  3. Production and Characterization of Atomized U-Mo Powder by the Rotating Electrode Process

    SciTech Connect (OSTI)

    C.R. Clark; B.R. Muntifering; J.F. Jue

    2007-09-01

    In order to produce feedstock fuel powder for irradiation testing, the Idaho National Laboratory has produced a rotating electrode type atomizer to fabricate uranium-molybdenum alloy fuel. Operating with the appropriate parameters, this laboratory-scale atomizer produces fuel in the desired size range for the RERTR dispersion experiments. Analysis of the powder shows a homogenous, rapidly solidified microstructure with fine equiaxed grains. This powder has been used to produce irradiation experiments to further test adjusted matrix U-Mo dispersion fuel.

  4. M-dwarf rapid rotators and the detection of relatively young multiple M-star systems

    SciTech Connect (OSTI)

    Rappaport, S.; Joss, M.; Sanchis-Ojeda, R. E-mail: mattjoss@mit.edu; and others

    2014-06-20

    We have searched the Kepler light curves of ?3900 M-star targets for evidence of periodicities that indicate, by means of the effects of starspots, rapid stellar rotation. Several analysis techniques, including Fourier transforms, inspection of folded light curves, 'sonograms', and phase tracking of individual modulation cycles, were applied in order to distinguish the periodicities due to rapid rotation from those due to stellar pulsations, eclipsing binaries, or transiting planets. We find 178 Kepler M-star targets with rotation periods, P {sub rot}, of <2 days, and 110 with P {sub rot} < 1 day. Some 30 of the 178 systems exhibit two or more independent short periods within the same Kepler photometric aperture, while several have 3 or more short periods. Adaptive optics imaging and modeling of the Kepler pixel response function for a subset of our sample support the conclusion that the targets with multiple periods are highly likely to be relatively young physical binary, triple, and even quadruple M star systems. We explore in detail the one object with four incommensurate periods all less than 1.2 days, and show that two of the periods arise from one of a close pair of stars, while the other two arise from the second star, which itself is probably a visual binary. If most of these M-star systems with multiple periods turn out to be bound M stars, this could prove a valuable way discovering young hierarchical M-star systems; the same approach may also be applicable to G and K stars. The ?5% occurrence rate of rapid rotation among the ?3900 M star targets is consistent with spin evolution models that include an initial contraction phase followed by magnetic braking, wherein a typical M star can spend several hundred Myr before spinning down to periods longer than 2 days.

  5. Statistical techniques for detecting the intergalactic magnetic field from large samples of extragalactic Faraday rotation data

    SciTech Connect (OSTI)

    Akahori, Takuya; Gaensler, B. M.; Ryu, Dongsu E-mail: bryan.gaensler@sydney.edu.au

    2014-08-01

    Rotation measure (RM) grids of extragalactic radio sources have been widely used for studying cosmic magnetism. However, their potential for exploring the intergalactic magnetic field (IGMF) in filaments of galaxies is unclear, since other Faraday-rotation media such as the radio source itself, intervening galaxies, and the interstellar medium of our Galaxy are all significant contributors. We study statistical techniques for discriminating the Faraday rotation of filaments from other sources of Faraday rotation in future large-scale surveys of radio polarization. We consider a 30° × 30° field of view toward the south Galactic pole, while varying the number of sources detected in both present and future observations. We select sources located at high redshifts and toward which depolarization and optical absorption systems are not observed so as to reduce the RM contributions from the sources and intervening galaxies. It is found that a high-pass filter can satisfactorily reduce the RM contribution from the Galaxy since the angular scale of this component toward high Galactic latitudes would be much larger than that expected for the IGMF. Present observations do not yet provide a sufficient source density to be able to estimate the RM of filaments. However, from the proposed approach with forthcoming surveys, we predict significant residuals of RM that should be ascribable to filaments. The predicted structure of the IGMF down to scales of 0.°1 should be observable with data from the Square Kilometre Array, if we achieve selections of sources toward which sightlines do not contain intervening galaxies and RM errors are less than a few rad m{sup –2}.

  6. Quantitative studies of human cardiac metabolism by /sup 31/P rotating-frame NMR

    SciTech Connect (OSTI)

    Blackledge, M.J.; Rajagopalan, B.; Oberhaensli, R.D.; Bolas, N.M.; Styles, P.; Radda, G.K.

    1987-06-01

    The authors have developed /sup 31/P NMR spectroscopic methods to determine quantitatively relative levels of phosphorus-containing metabolites in the human myocardium. They have used localization techniques based on the rotating-frame imaging experiment and carried out the double-surface coil probe. Information is obtained from selected slices by rotating-frame depth selection and from a complete one-dimensional spectroscopic image using phase-modulated rotating-frame imaging. The methods collect biochemical information from metabolites in human heart, and they use the fact that the phosphocreatine/ATP molar ratio in skeletal muscle at rest is higher than that in working heart to demonstrate that localization ha been achieved for each investigation. The phosphocreatine/ATP molar ratio in normal human heart has been measured as 1.55 +/- 0.20 in six subjects using dept selection and as 1.53 +/- 0.25 in four subjects using spectroscopic imaging. Measurement of this ratio is expected to give a useful and reproducible index of myocardial energetics in normal and pathological states.

  7. In situ synchrotron study of electromigration induced grain rotations in Sn solder joints

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shen, Hao; Zhu, Wenxin; Li, Yao; Tamura, Nobumichi; Chen, Kai

    2016-04-18

    In this paper we report an in situ study of the early stage of microstructure evolution induced by electromigration in a Pb-free β-Sn based solder joint by synchrotron polychromatic X-ray microdiffraction. With this technique, crystal orientation evolution is monitored at intragranular levels with high spatial and angular resolution. During the entire experiment, no crystal growth is detected, and rigid grain rotation is observed only in the two grains within the current crowding region, where high density and divergence of electric current occur. Theoretical calculation indicates that the trend of electrical resistance drop still holds under the present conditions in themore » grain with high electrical resistivity, while the other grain with low resistivity reorients to align its a-axis more parallel with the ones of its neighboring grains. A detailed study of dislocation densities and subgrain boundaries suggests that grain rotation in β-Sn, unlike grain rotation in high melting temperature metals which undergo displacive deformation, is accomplished via diffusional process mainly, due to the high homologous temperature.« less

  8. Slowly rotating neutron and strange stars in R{sup 2} gravity

    SciTech Connect (OSTI)

    Staykov, Kalin V.; Yazadjiev, Stoytcho S.; Doneva, Daniela D.; Kokkotas, Kostas D. E-mail: daniela.doneva@uni-tuebingen.de E-mail: kostas.kokkotas@uni-tuebingen.de

    2014-10-01

    In the present paper we investigate self-consistently slowly rotating neutron and strange stars in R-squared gravity with Lagrangian f(R)=R+aR{sup 2}, where a is a parameter. For this purpose we first derive the equations describing the structure of the slowly rotating compact stars in f(R)-gravity and then simultaneously solve numerically the exterior and the interior problem. The structure of the slowly rotating neutron stars is studied for two different hadronic equations of state and a strange matter equation of state. The moment of inertia and its dependence on the stellar mass and the R-squared gravity parameter a is also examined in details. The numerical results show that the neutron star moment of inertia can be up to 30% larger compared to the corresponding general relativistic models. This is much higher than the change in the maximum mass induced by R-squared gravity and is beyond the EOS uncertainty. In this way the future observations of the moment of inertia of compact stars could allow us to distinguish between general relativity and f(R) gravity, and more generally to test the strong field regime of gravity.

  9. Grid artifact reduction for direct digital radiography detectors based on rotated stationary grids with homomorphic filtering

    SciTech Connect (OSTI)

    Kim, Dong Sik; Lee, Sanggyun

    2013-06-15

    Purpose: Grid artifacts are caused when using the antiscatter grid in obtaining digital x-ray images. In this paper, research on grid artifact reduction techniques is conducted especially for the direct detectors, which are based on amorphous selenium. Methods: In order to analyze and reduce the grid artifacts, the authors consider a multiplicative grid image model and propose a homomorphic filtering technique. For minimal damage due to filters, which are used to suppress the grid artifacts, rotated grids with respect to the sampling direction are employed, and min-max optimization problems for searching optimal grid frequencies and angles for given sampling frequencies are established. The authors then propose algorithms for the grid artifact reduction based on the band-stop filters as well as low-pass filters. Results: The proposed algorithms are experimentally tested for digital x-ray images, which are obtained from direct detectors with the rotated grids, and are compared with other algorithms. It is shown that the proposed algorithms can successfully reduce the grid artifacts for direct detectors. Conclusions: By employing the homomorphic filtering technique, the authors can considerably suppress the strong grid artifacts with relatively narrow-bandwidth filters compared to the normal filtering case. Using rotated grids also significantly reduces the ringing artifact. Furthermore, for specific grid frequencies and angles, the authors can use simple homomorphic low-pass filters in the spatial domain, and thus alleviate the grid artifacts with very low implementation complexity.

  10. On the nature of local instabilities in rotating galactic coronae and cool cores of galaxy clusters

    SciTech Connect (OSTI)

    Nipoti, Carlo; Posti, Lorenzo

    2014-09-01

    A long-standing question is whether radiative cooling can lead to local condensation of cold gas in the hot atmospheres of galaxies and galaxy clusters. We address this problem by studying the nature of local instabilities in rotating, stratified, weakly magnetized, optically thin plasmas in the presence of radiative cooling and anisotropic thermal conduction. For both axisymmetric and nonaxisymmetric linear perturbations, we provide general equations which can be applied locally to specific systems to establish whether they are unstable and, in case of instability, to determine the kind of evolution (monotonically growing or overstable) and the growth rates of the unstable modes. We present results for models of rotating plasmas representative of Milky-Way-like galaxy coronae and cool-cores of galaxy clusters. We show that the unstable modes arise from a combination of thermal, magnetothermal, magnetorotational, and heat-flux-driven buoyancy instabilities. Local condensation of cold clouds tends to be hampered in cluster cool cores, while it is possible under certain conditions in rotating galactic coronae. If the magnetic field is sufficiently weak, then the magnetorotational instability is dominant even in these pressure-supported systems.

  11. Rotating magnetic field current drive of high-temperature field reversed configurations with high {zeta} scaling

    SciTech Connect (OSTI)

    Guo, H. Y.; Hoffman, A. L.; Milroy, R. D.

    2007-11-15

    Greatly reduced recycling and impurity ingestion in the Translation, Confinement, and Sustainment--Upgrade (TCSU) device has allowed much higher plasma temperatures to be achieved in the field reversed configurations (FRC) under rotating magnetic field (RMF) formation and sustainment. The hotter plasmas have higher magnetic fields and much higher diamagnetic electron rotation rates so that the important ratio of average electron rotation frequency to RMF frequency, called {zeta}, approaches unity, for the first time, in TCSU. A large fraction of the RMF power is absorbed by an as yet unexplained (anomalous) mechanism directly proportional to the square of the RMF magnitude. It becomes of relatively lesser significance as the FRC current increases, and simple resistive heating begins to dominate, but the anomalous absorption is useful for initial plasma heating. Measurements of total absorbed power, and comparisons of applied RMF torque to torque on the electrons due to electron-ion friction under high-{zeta} operation, over a range of temperatures and fields, have allowed the separation of the classical Ohmic and anomalous heating to be inferred, and cross-field plasma resistivities to be calculated.

  12. Thermodynamics of rotating charged black branes in third order lovelock gravity and the counterterm method

    SciTech Connect (OSTI)

    Dehghani, M.H.; Mann, R.B.

    2006-05-15

    We generalize the quasilocal definition of the stress-energy tensor of Einstein gravity to the case of third order Lovelock gravity, by introducing the surface terms that make the action well-defined. We also introduce the boundary counterterm that removes the divergences of the action and the conserved quantities of the solutions of third order Lovelock gravity with zero curvature boundary at constant t and r. Then, we compute the charged rotating solutions of this theory in n+1 dimensions with a complete set of allowed rotation parameters. These charged rotating solutions present black hole solutions with two inner and outer event horizons, extreme black holes or naked singularities provided the parameters of the solutions are suitably chosen. We compute temperature, entropy, charge, electric potential, mass and angular momenta of the black hole solutions, and find that these quantities satisfy the first law of thermodynamics. We find a Smarr-type formula and perform a stability analysis by computing the heat capacity and the determinant of Hessian matrix of mass with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles, and show that the system is thermally stable. This is commensurate with the fact that there is no Hawking-Page phase transition for black objects with zero curvature horizon.

  13. Thermodynamics of rotating solutions in Gauss-Bonnet-Maxwell gravity and the counterterm method

    SciTech Connect (OSTI)

    Dehghani, M. H.; Bordbar, G. H.; Shamirzaie, M.

    2006-09-15

    By a suitable transformation, we present the (n+1)-dimensional charged rotating solutions of Gauss-Bonnet gravity with a complete set of allowed rotation parameters which are real in the whole spacetime. We show that these charged rotating solutions present black hole solutions with two inner and outer event horizons, extreme black holes, or naked singularities provided the parameters of the solutions are chosen suitable. Using the surface terms that make the action well defined for Gauss-Bonnet gravity and the counterterm method for eliminating the divergences in action, we compute finite action of the solutions. We compute the conserved and thermodynamical quantities through the use of free energy and the counterterm method, and find that the two methods give the same results. We also find that these quantities satisfy the first law of thermodynamics. Finally, we perform a stability analysis by computing the heat capacity and the determinant of Hessian matrix of mass with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles, and show that the system is thermally stable. This is commensurate with the fact that there is no Hawking-Page phase transition for black objects with zero curvature horizon.

  14. Impacts of rotation on three-dimensional hydrodynamics of core-collapse supernovae

    SciTech Connect (OSTI)

    Nakamura, Ko; Kuroda, Takami; Kotake, Kei [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Takiwaki, Tomoya [Center for Computational Astrophysics, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2014-09-20

    We perform a series of simplified numerical experiments to explore how rotation impacts the three-dimensional (3D) hydrodynamics of core-collapse supernovae. For our systematic study, we employ a light-bulb scheme to trigger explosions and a three-flavor neutrino leakage scheme to treat deleptonization effects and neutrino losses from the proto-neutron-star interior. Using a 15 M {sub ?} progenitor, we compute 30 models in 3D with a wide variety of initial angular momentum and light-bulb neutrino luminosity. We find that the rotation can help the onset of neutrino-driven explosions for the models in which the initial angular momentum is matched to that obtained in recent stellar evolutionary calculations (?0.3-3 rad s{sup 1} at the center). For the models with larger initial angular momentum, the shock surface deforms to be more oblate due to larger centrifugal force. This not only makes the gain region more concentrated around the equatorial plane, but also makes the mass larger in the gain region. As a result, buoyant bubbles tend to be coherently formed and rise in the equatorial region, which pushes the revived shock toward ever larger radii until a global explosion is triggered. We find that these are the main reasons that the preferred direction of the explosion in 3D rotating models is often perpendicular to the spin axis, which is in sharp contrast to the polar explosions around the axis that were obtained in previous two-dimensional simulations.

  15. Rotating stall control of an axial flow compressor using pulsed air injection

    SciTech Connect (OSTI)

    D`Andrea, R.; Behnken, R.L.

    1997-10-01

    This paper presents the use of pulsed air injection to control rotating stall in a low-speed, axial flow compressor. In the first part of the paper, the injection of air is modeled as an unsteady shift of the compressor characteristic, and incorporated into a low dimensional model of the compressor. By observing the change in the bifurcation behavior of this model subject to nonlinear feedback, the viability of various air injection orientations is established. An orientation consistent with this analysis is then used for feedback control. By measuring the unsteady pressures near the rotor face, a control algorithm determines the magnitude and phase of the first mode of rotating stall and controls the injection of air in the front of the rotor face. Experimental results show that this technique eliminates the hysteresis loop normally associated with rotating stall. A parametric study is used to determine the optimal control parameters for suppression of stall. The resulting control strategy is also shown to suppress surge when a plenum is present. Using a high-fidelity model, the main features of the experimental results are duplicated via simulations.

  16. Propagation speed of rotation signals for field lines undergoing magnetic reconnection

    SciTech Connect (OSTI)

    Lapenta, Giovanni; Goldman, Martin; Newman, David; Markidis, Stefano

    2013-10-15

    Reconnection is associated with two bending of the magnetic field lines. Considering the usual plane of a 2D reconnection simulation, the first bending is in-plane and produces the needed topological changes by bringing oppositely directed filed lines in proximity. The second is typical of fast reconnection and is out of plane, leading to the formation of the Hall magnetic field. This second rotation has recently been observed to proceed at superAlfvénic speeds and to carry substantial energy fluxes (Shay et al., Phys. Rev. Lett. 107, 065001 (2011)). We revisit these rotations with a new diagnostics based on dispersing a multitude of virtual probes into a kinetic simulation, akin the approach of multi spacecraft missions. The results of the new diagnostics are compared with the theory of characteristics applied to the two fluid model. The comparison of virtual probes and the method of characteristics confirm the findings relative to the out of plane rotation and uncover the existence of two families of characteristics. Both are observed in the simulation. The early stage of reconnection develops on the slower compressional branch and the later faster phase develops on the faster torsional branch. The superAlfvénic signal is only relevant in the second phase.

  17. Tully-Fisher relation, galactic rotation curves and dissipative mirror dark matter

    SciTech Connect (OSTI)

    Foot, R.

    2014-12-01

    If dark matter is dissipative then the distribution of dark matter within galactic halos can be governed by dissipation, heating and hydrostatic equilibrium. Previous work has shown that a specific model, in the framework of mirror dark matter, can explain several empirical galactic scaling relations. It is shown here that this dynamical halo model implies a quasi-isothermal dark matter density, ρ(r) ≅ ρ{sub 0}r{sub 0}{sup 2}/(r{sup 2}+r{sub 0}{sup 2}), where the core radius, r{sub 0}, scales with disk scale length, r{sub D}, via r{sub 0}/kpc ≈ 1.4(r{sub D}/kpc). Additionally, the product ρ{sub 0}r{sub 0} is roughly constant, i.e. independent of galaxy size (the constant is set by the parameters of the model). The derived dark matter density profile implies that the galactic rotation velocity satisfies the Tully-Fisher relation, L{sub B}∝v{sup 3}{sub max}, where v{sub max} is the maximal rotational velocity. Examples of rotation curves resulting from this dynamics are given.

  18. ROTATIONAL CORRECTIONS TO NEUTRON-STAR RADIUS MEASUREMENTS FROM THERMAL SPECTRA

    SciTech Connect (OSTI)

    Baubck, Michi; zel, Feryal; Psaltis, Dimitrios; Morsink, Sharon M.

    2015-01-20

    We calculate the rotational broadening in the observed thermal spectra of neutron stars spinning at moderate rates in the Hartle-Thorne approximation. These calculations accurately account for the effects of the second-order Doppler boosts as well as for the oblate shapes and the quadrupole moments of the neutron stars. We find that fitting the spectra and inferring the bolometric fluxes under the assumption that a star is not rotating causes an underestimate of the inferred fluxes and, thus, radii. The correction depends on the stellar spin, mass, radius, and the observer's inclination. For a 10km, 1.4 M {sub ?} neutron star spinning at 600Hz, the rotational correction to the flux is ?1%-4%, while for a 15km neutron star with the same spin period, the correction ranges from 2% for pole-on sources to 12% for edge-on sources. We calculate the inclination-averaged corrections to inferred radii as a function of the neutron-star radius and mass and provide an empirical formula for the corrections. For realistic neutron-star parameters (1.4 M {sub ?}, 12km, 600Hz), the stellar radius is on the order of 4% larger than the radius inferred under the assumption that the star is not spinning.

  19. A. L. P. O. solar section observations for rotations 1818-1823 (1989 Jul 19 to Dec 29)

    SciTech Connect (OSTI)

    Hill, R.E. )

    1990-11-01

    This report summaries A.L.P.O. solar section observations for rotations 1818-1823 July 19 to December 29, 1989, particularly in terms of the morphology and development of sunspot groups. Twenty-four observers in five nations contributed visual drawings and integrated-light and H-alpha photographs. Solar activity tended to increase in this period; the highest rotational means were slightly lower, but the lowest means were somewhat higher, than those for the previous reporting period (Rotations 1813-1817). 9 refs.

  20. Rotational Augmentation on a 2.3 MW Rotor Blade with Thick Flatback Airfoil Cross-Sections: Preprint

    SciTech Connect (OSTI)

    Schreck, S.; Fingersh, L.; Siegel, K.; Singh, M.; Medina, P.

    2013-01-01

    Rotational augmentation was analyzed for a 2.3 MW wind turbine, which was equipped with thick flatback airfoils at inboard radial locations and extensively instrumented for acquisition of time varying surface pressures. Mean aerodynamic force and surface pressure data were extracted from an extensive field test database, subject to stringent criteria for wind inflow and turbine operating conditions. Analyses of these data showed pronounced amplification of aerodynamic forces and significant enhancements to surface pressures in response to rotational influences, relative to two-dimensional, stationary conditions. Rotational augmentation occurrence and intensity in the current effort was found to be consistent with that observed in previous research. Notably, elevated airfoil thickness and flatback design did not impede rotational augmentation.

  1. Study of nonneutral plasma storage in a magnetic trap with a rotating electric field at the lepta facility

    SciTech Connect (OSTI)

    Eseev, M. K.; Kobets, A. G.; Meshkov, I. N.; Rudakov, A. Yu.; Yakovenko, S. L.

    2013-10-15

    Results from experimental studies of plasma storage in a Penning-Malmberg trap at the LEPTA facility are presented. The number of stored particles is found to increase substantially when using the so-called “rotating wall” method, in which a transverse rotating electric field generated by a cylindrical segmented electrode cut into four pairs is applied to the plasma storage region. The conditions of transverse compression of the plasma bunch under the action of the rotating field and buffer gas are studied. The optimal storage parameters are determined for these experimental conditions. Mechanisms of the action of the rotating field and buffer gas on the process of plasma storage are discussed.

  2. Method for producing H.sub.2 using a rotating drum reactor with a pulse jet heat source

    DOE Patents [OSTI]

    Paulson, Leland E. (Morgantown, WV)

    1990-01-01

    A method of producing hydrogen by an endothermic steam-carbon reaction using a rotating drum reactor and a pulse jet combustor. The pulse jet combustor uses coal dust as a fuel to provide reaction temperatures of 1300.degree. to 1400.degree. F. Low-rank coal, water, limestone and catalyst are fed into the drum reactor where they are heated, tumbled and reacted. Part of the reaction product from the rotating drum reactor is hydrogen which can be utilized in suitable devices.

  3. ROTATING MOTIONS AND MODELING OF THE ERUPTING SOLAR POLAR-CROWN PROMINENCE ON 2010 DECEMBER 6

    SciTech Connect (OSTI)

    Su, Yingna; Van Ballegooijen, Adriaan

    2013-02-10

    A large polar-crown prominence composed of different segments spanning nearly the entire solar disk erupted on 2010 December 6. Prior to the eruption, the filament in the active region part split into two layers: a lower layer and an elevated layer. The eruption occurs in several episodes. Around 14:12 UT, the lower layer of the active region filament breaks apart: One part ejects toward the west, while the other part ejects toward the east, which leads to the explosive eruption of the eastern quiescent filament. During the early rise phase, part of the quiescent filament sheet displays strong rolling motion (observed by STEREO-B) in the clockwise direction (viewed from east to west) around the filament axis. This rolling motion appears to start from the border of the active region, then propagates toward the east. The Atmospheric Imaging Assembly (AIA) observes another type of rotating motion: In some other parts of the erupting quiescent prominence, the vertical threads turn horizontal, then turn upside down. The elevated active region filament does not erupt until 18:00 UT, when the erupting quiescent filament has already reached a very large height. We develop two simplified three-dimensional models that qualitatively reproduce the observed rolling and rotating motions. The prominence in the models is assumed to consist of a collection of discrete blobs that are tied to particular field lines of a helical flux rope. The observed rolling motion is reproduced by continuous twist injection into the flux rope in Model 1 from the active region side. Asymmetric reconnection induced by the asymmetric distribution of the magnetic fields on the two sides of the filament may cause the observed rolling motion. The rotating motion of the prominence threads observed by AIA is consistent with the removal of the field line dips in Model 2 from the top down during the eruption.

  4. Hidden conformal symmetry of rotating black holes in minimal five-dimensional gauged supergravity

    SciTech Connect (OSTI)

    Setare, M. R.; Kamali, V.

    2010-10-15

    In the present paper we show that for a low frequency limit the wave equation of a massless scalar field in the background of nonextremal charged rotating black holes in five-dimensional minimal gauged and ungauged supergravity can be written as the Casimir of an SL(2,R) symmetry. Our result shows that the entropy of the black hole is reproduced by the Cardy formula. Also the absorption cross section is consistent with the finite temperature absorption cross section for a two-dimensional conformal field theory.

  5. Method and apparatus for monitoring the rotating frequency of de-energized induction motors

    DOE Patents [OSTI]

    Mikesell, Harvey E.; Lucy, Eric

    1998-01-01

    The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor.

  6. Method and apparatus for monitoring the rotating frequency of de-energized induction motors

    DOE Patents [OSTI]

    Mikesell, H.E.; Lucy, E.

    1998-02-03

    The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor. 6 figs.

  7. Direct imaging of rotational wave-packet dynamics of diatomic molecules

    SciTech Connect (OSTI)

    Dooley, P. W.; Lee, Kevin F.; Corkum, P. B.; Litvinyuk, I. V.; Rayner, D. M.; Villeneuve, D. M.; Spanner, M.

    2003-08-01

    We use linearly polarized 45 fs pulses to create rotational wave packets in N{sub 2} and O{sub 2}. We Coulomb explode molecules with a high-intensity circularly polarized pulse and use an ion imaging detector to measure a series of two-dimensional projections of the wave packet's angular distribution in 27 fs increments. We highlight the evolving wave packet near the first, second, sixth, and tenth full revival times and also near the one-eighth, one-quarter, one-half, and three-quarter fractional revivals.

  8. The factory and the beehive. II. Activity and rotation in Praesepe and the Hyades

    SciTech Connect (OSTI)

    Douglas, S. T.; Ageros, M. A.; Bowsher, E. C.; Lemonias, J. J.; Fierroz, D. F.; Covey, K. R.; Bochanski, J. J.; Cargile, P. A.; Kraus, A.; Law, N. M.; Arce, H. G.; Kundert, A.

    2014-11-10

    Open clusters are collections of stars with a single, well-determined age, and can be used to investigate the connections between angular-momentum evolution and magnetic activity over a star's lifetime. We present the results of a comparative study of the relationship between stellar rotation and activity in two benchmark open clusters: Praesepe and the Hyades. As they have the same age and roughly solar metallicity, these clusters serve as an ideal laboratory for testing the agreement between theoretical and empirical rotation-activity relations at ?600 Myr. We have compiled a sample of 720 spectramore than half of which are new observationsfor 516 high-confidence members of Praesepe; we have also obtained 139 new spectra for 130 high-confidence Hyads. We have also collected rotation periods (P {sub rot}) for 135 Praesepe members and 87 Hyads. To compare H? emission, an indicator of chromospheric activity, as a function of color, mass, and Rossby number R{sub o} , we first calculate an expanded set of ? values, with which we can obtain the H? to bolometric luminosity ratio, L {sub H?}/L {sub bol}, even when spectra are not flux-calibrated and/or stars lack reliable distances. Our ? values cover a broader range of stellar masses and colors (roughly equivalent to spectral types from K0 to M9), and exhibit better agreement between independent calculations, than existing values. Unlike previous authors, we find no difference between the two clusters in their H? equivalent width or L {sub H?}/L {sub bol} distributions, and therefore take the merged H? and P {sub rot} data to be representative of 600 Myr old stars. Our analysis shows that H? activity in these stars is saturated for R{sub o}?0.11{sub ?0.03}{sup +0.02}. Above that value activity declines as a power-law with slope ?=?0.73{sub ?0.12}{sup +0.16}, before dropping off rapidly at R{sub o} ? 0.4. These data provide a useful anchor for calibrating the age-activity-rotation relation beyond 600 Myr.

  9. Diffusion coefficients of Fokker-Planck equation for rotating dust grains in a fusion plasma

    SciTech Connect (OSTI)

    Bakhtiyari-Ramezani, M. Alinejad, N.; Mahmoodi, J.

    2015-11-15

    In the fusion devices, ions, H atoms, and H{sub 2} molecules collide with dust grains and exert stochastic torques which lead to small variations in angular momentum of the grain. By considering adsorption of the colliding particles, thermal desorption of H atoms and normal H{sub 2} molecules, and desorption of the recombined H{sub 2} molecules from the surface of an oblate spheroidal grain, we obtain diffusion coefficients of the Fokker-Planck equation for the distribution function of fluctuating angular momentum. Torque coefficients corresponding to the recombination mechanism show that the nonspherical dust grains may rotate with a suprathermal angular velocity.

  10. Rotating diffuser for pressure recovery in a steam cooling circuit of a gas turbine

    DOE Patents [OSTI]

    Eldrid, Sacheverel Q.; Salamah, Samir A.; DeStefano, Thomas Daniel

    2002-01-01

    The buckets of a gas turbine are steam-cooled via a bore tube assembly having concentric supply and spent cooling steam return passages rotating with the rotor. A diffuser is provided in the return passage to reduce the pressure drop. In a combined cycle system, the spent return cooling steam with reduced pressure drop is combined with reheat steam from a heat recovery steam generator for flow to the intermediate pressure turbine. The exhaust steam from the high pressure turbine of the combined cycle unit supplies cooling steam to the supply conduit of the gas turbine.

  11. Mechanical and Thermal Prototype Testing for a Rotatable Collimator for the LHC Phase II Collimation Upgrade

    SciTech Connect (OSTI)

    Smith, Jeffrey Claiborne; Doyle, Eric; Keller, Lewis; Lundgren, Steven; Markiewicz, Thomas Walter; ,

    2010-08-26

    The Phase II upgrade to the LHC collimation system calls for complementing the robust Phase I graphite collimators with high Z, low impedance Phase II collimators. The design for the collimation upgrade has not been finalized. One option is to use metallic rotatable collimators and testing of this design will be discussed here. The Phase II collimators must be robust in various operating conditions and accident scenarios. A prototype collimator jaw has been tested for both mechanical and thermal compliance with the design goals. Thermal expansion bench-top tests are compared to ANSYS simulation results.

  12. Method and system for controlling a rotational speed of a rotor of a turbogenerator

    DOE Patents [OSTI]

    Stahlhut, Ronnie Dean; Vuk, Carl Thomas

    2008-12-30

    A system and method controls a rotational speed of a rotor or shaft of a turbogenerator in accordance with a present voltage level on a direct current bus. A lower threshold and a higher threshold are established for a speed of a rotor or shaft of a turbogenerator. A speed sensor determines speed data or a speed signal for the rotor or shaft associated with a turbogenerator. A voltage regulator adjusts a voltage level associated with a direct current bus within a target voltage range if the speed data or speed signal indicates that the speed is above the higher threshold or below the lower threshold.

  13. Enhanced Confinement and Stability of a Field-Reversed Configuration with Rotating Magnetic Field Current Drive

    SciTech Connect (OSTI)

    Slough, J. T.; Miller, K. E.

    2000-08-14

    A new experiment has been constructed to study the sustainment of a field-reversed configuration (FRC) with a rotating magnetic field (RMF). FRCs were formed with cold, unmagnetized ions and thus without a kinetic ion component that was believed to provide stability to internal tilt modes. No destructive instabilities were observed for the RMF FRC. Only peripheral radial penetration of the RMF was observed. The radially inward flow arising from axial screening currents at the FRC edge reduced convective and conductive losses to the measurement limit of the diagnostics. (c) 2000 The American Physical Society.

  14. Off-axis cooling of rotating devices using a crank-shaped heat pipe

    DOE Patents [OSTI]

    Jankowski, Todd A.; Prenger, F. Coyne; Waynert, Joseph A.

    2007-01-30

    The present invention is a crank-shaped heat pipe for cooling rotating machinery and a corresponding method of manufacture. The crank-shaped heat pipe comprises a sealed cylindrical tube with an enclosed inner wick structure. The crank-shaped heat pipe includes a condenser section, an adiabatic section, and an evaporator section. The crank-shape is defined by a first curve and a second curve existing in the evaporator section or the adiabatic section of the heat pipe. A working fluid within the heat pipe provides the heat transfer mechanism.

  15. Dissipation in a rotating frame: Master equation, effective temperature, and Lamb shift

    SciTech Connect (OSTI)

    Verso, Alvise; Ankerhold, Joachim

    2010-02-15

    Motivated by recent realizations of microwave-driven nonlinear resonators in superconducting circuits, the impact of environmental degrees of freedom is analyzed as seen from a rotating frame. A system plus reservoir model is applied to consistently derive in the weak coupling limit the master equation for the reduced density in the moving frame and near the first bifurcation threshold. The concept of an effective temperature is introduced to analyze to what extent a detailed balance relation exists. Explicit expressions are also found for the Lamb-shift. Results for ohmic baths are in agreement with experimental findings, while for structured environments population inversion is predicted that may qualitatively explain recent observations.

  16. SU-E-T-170: Evaluation of Rotational Errors in Proton Therapy Planning of Lung Cancer

    SciTech Connect (OSTI)

    Rana, S; Zhao, L; Ramirez, E; Singh, H; Zheng, Y

    2014-06-01

    Purpose: To investigate the impact of rotational (roll, yaw, and pitch) errors in proton therapy planning of lung cancer. Methods: A lung cancer case treated at our center was used in this retrospective study. The original plan was generated using two proton fields (posterior-anterior and left-lateral) with XiO treatment planning system (TPS) and delivered using uniform scanning proton therapy system. First, the computed tomography (CT) set of original lung treatment plan was re-sampled for rotational (roll, yaw, and pitch) angles ranged from ?5 to +5, with an increment of 2.5. Second, 12 new proton plans were generated in XiO using the 12 re-sampled CT datasets. The same beam conditions, isocenter, and devices were used in new treatment plans as in the original plan. All 12 new proton plans were compared with original plan for planning target volume (PTV) coverage and maximum dose to spinal cord (cord Dmax). Results: PTV coverage was reduced in all 12 new proton plans when compared to that of original plan. Specifically, PTV coverage was reduced by 0.03% to 1.22% for roll, by 0.05% to 1.14% for yaw, and by 0.10% to 3.22% for pitch errors. In comparison to original plan, the cord Dmax in new proton plans was reduced by 8.21% to 25.81% for +2.5 to +5 pitch, by 5.28% to 20.71% for +2.5 to +5 yaw, and by 5.28% to 14.47% for ?2.5 to ?5 roll. In contrast, cord Dmax was increased by 3.80% to 3.86% for ?2.5 to ?5 pitch, by 0.63% to 3.25% for ?2.5 to ?5 yaw, and by 3.75% to 4.54% for +2.5 to +5 roll. Conclusion: PTV coverage was reduced by up to 3.22% for rotational error of 5. The cord Dmax could increase or decrease depending on the direction of rotational error, beam angles, and the location of lung tumor.

  17. Independent control of electron energy and density using a rotating magnetic field in inductively coupled plasmas

    SciTech Connect (OSTI)

    Kondo, Takahiro; Ohta, Masayuki; Ito, Tsuyohito; Okada, Shigefumi

    2013-09-21

    Effects of a rotating magnetic field (RMF) on the electron energy distribution function (EEDF) and on the electron density are investigated with the aim of controlling the radical composition of inductively coupled plasmas. By adjusting the RMF frequency and generation power, the desired electron density and electron energy shift are obtained. Consequently, the amount and fraction of high-energy electrons, which are mostly responsible for direct dissociation processes of raw molecules, will be controlled externally. This controllability, with no electrode exposed to plasma, will enable us to control radical components and their flux during plasma processing.

  18. ARM - Measurement - Atmospheric moisture

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... Measurements associated with the Aerosol Observing System UAV-MET-OTTER : Meteorology from UAV-Twin Otter MFRSR-WV1MICH : MFRSR-WV-Michalsky1 MWRP : Microwave ...

  19. ROTATIONAL SYNCHRONIZATION MAY ENHANCE HABITABILITY FOR CIRCUMBINARY PLANETS: KEPLER BINARY CASE STUDIES

    SciTech Connect (OSTI)

    Mason, Paul A.; Zuluaga, Jorge I.; Cuartas-Restrepo, Pablo A.; Clark, Joni M.

    2013-09-10

    We report a mechanism capable of reducing (or increasing) stellar activity in binary stars, thereby potentially enhancing (or destroying) circumbinary habitability. In single stars, stellar aggression toward planetary atmospheres causes mass-loss, which is especially detrimental for late-type stars, because habitable zones are very close and activity is long lasting. In binaries, tidal rotational breaking reduces magnetic activity, thus reducing harmful levels of X-ray and ultraviolet (XUV) radiation and stellar mass-loss that are able to erode planetary atmospheres. We study this mechanism for all confirmed circumbinary (p-type) planets. We find that main sequence twins provide minimal flux variation and in some cases improved environments if the stars rotationally synchronize within the first Gyr. Solar-like twins, like Kepler 34 and Kepler 35, provide low habitable zone XUV fluxes and stellar wind pressures. These wide, moist, habitable zones may potentially support multiple habitable planets. Solar-type stars with lower mass companions, like Kepler 47, allow for protected planets over a wide range of secondary masses and binary periods. Kepler 38 and related binaries are marginal cases. Kepler 64 and analogs have dramatically reduced stellar aggression due to synchronization of the primary, but are limited by the short lifetime. Kepler 16 appears to be inhospitable to planets due to extreme XUV flux. These results have important implications for estimates of the number of stellar systems containing habitable planets in the Galaxy and allow for the selection of binaries suitable for follow-up searches for habitable planets.

  20. HERSCHEL AND SPITZER OBSERVATIONS OF SLOWLY ROTATING, NEARBY ISOLATED NEUTRON STARS

    SciTech Connect (OSTI)

    Posselt, B.; Pavlov, G. G.; Popov, S.; Wachter, S.

    2014-11-01

    Supernova fallback disks around neutron stars have been suspected to influence the evolution of the diverse neutron star populations. Slowly rotating neutron stars are the most promising places to find such disks. Searching for the cold and warm debris of old fallback disks, we carried out Herschel PACS (70 μm, 160 mu m) and Spitzer IRAC (3.6 μm, 4.5 μm) observations of eight slowly rotating (P ≈ 3-11 s) nearby (<1 kpc) isolated neutron stars. Herschel detected 160 μm emission (>5σ) at locations consistent with the positions of the neutron stars RX J0806.4-4123 and RX J2143.0+0654. No other significant infrared emission was detected from the eight neutron stars. We estimate probabilities of 63%, 33%, and 3% that, respectively, none, one, or both Herschel PACS 160 μm detections are unrelated excess sources due to background source confusion or an interstellar cirrus. If the 160 μm emission is indeed related to cold (10-22 K) dust around the neutron stars, this dust is absorbing and re-emitting ∼10% to ∼20% of the neutron stars' X-rays. Such high efficiencies would be at least three orders of magnitude larger than the efficiencies of debris disks around nondegenerate stars. While thin dusty disks around the neutron stars can be excluded as counterparts of the 160 μm emission, dusty asteroid belts constitute a viable option.

  1. UBIQUITOUS ROTATING NETWORK MAGNETIC FIELDS AND EXTREME-ULTRAVIOLET CYCLONES IN THE QUIET SUN

    SciTech Connect (OSTI)

    Zhang Jun; Liu Yang E-mail: yliu@sun.stanford.edu

    2011-11-01

    We present Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) observations of EUV cyclones in the quiet Sun. These cyclones are rooted in the rotating network magnetic fields (RNFs). Such cyclones can last several to more than 10 hr and, at the later phase, they are found to be associated with EUV brightenings (microflares) and even EUV waves. SDO Helioseismic and Magnetic Imager (HMI) observations show a ubiquitous presence of RNFs. Using HMI line-of-sight magnetograms on 2010 July 8, we find 388 RNFs in an area of 800 x 980 arcsec{sup 2} near the disk center where no active region is present. The sense of rotation shows a weak hemisphere preference. The unsigned magnetic flux of the RNFs is about 4.0 x 10{sup 21} Mx, or 78% of the total network flux. These observational phenomena at small scale reported in this Letter are consistent with those at large scale in active regions. The ubiquitous RNFs and EUV cyclones over the quiet Sun may suggest an effective way to heat the corona.

  2. The BANANA project. V. Misaligned and precessing stellar rotation axes in CV Velorum

    SciTech Connect (OSTI)

    Albrecht, Simon; Winn, Joshua N.; Triaud, Amaury; Torres, Guillermo; Fabrycky, Daniel C.; Setiawan, Johny; Gillon, Michaël; Jehin, Emmanuel; Queloz, Didier; Snellen, Ignas; Eggleton, Peter

    2014-04-20

    As part of the Binaries Are Not Always Neatly Aligned project (BANANA), we have found that the eclipsing binary CV Velorum has misaligned rotation axes. Based on our analysis of the Rossiter-McLaughlin effect, we find sky-projected spin-orbit angles of β{sub p} = –52° ± 6° and β{sub s} = 3° ± 7° for the primary and secondary stars (B2.5V + B2.5V, P = 6.9 days). We combine this information with several measurements of changing projected stellar rotation speeds (vsin i {sub *}) over the last 30 yr, leading to a model in which the primary star's obliquity is ≈65°, and its spin axis precesses around the total angular momentum vector with a period of about 140 yr. The geometry of the secondary star is less clear, although a significant obliquity is also implicated by the observed time variations in the vsin i {sub *}. By integrating the secular tidal evolution equations backward in time, we find that the system could have evolved from a state of even stronger misalignment similar to DI Herculis, a younger but otherwise comparable binary.

  3. Dynamics of local isolated magnetic flux tubes in a fast-rotating stellar atmosphere

    SciTech Connect (OSTI)

    Chou, W.; Tajima, C.T.; Matsumoto, R. |; Shibata, K.

    1998-01-01

    Dynamics of magnetic flux tubes in the fast rotating stellar atmosphere is studied. We focus on the effects and signatures of the instability of the flux tube emergence influenced by the Coriolis force. We present the result from a linear stability analysis and discuss its possible signatures in the course of the evolution of G-type and M-type stars. We present a three dimensional magnetohydrodynamical simulation of local isolated magnetic flux tubes under a magnetic buoyancy instability in co-rotating Cartesian coordinates. We find that the combination of the buoyancy instability and the Coriolis effect gives rise to a mechanism, to twist the emerging magnetic flux tube into a helical structure. The tilt angle, east-west asymmetry and magnetic helicity of the Twisted flux tubes in the simulations are studied in detail. The linear and nonlinear analyses provide hints as to what kind of pattern of large spots in young M-type main-sequence stars might be observed. We find that young and old G-type stars may have different distributions of spots while M-type stars may always have low latitudes spots. The size of stellar spots may decrease when a star becomes older, due to the decreasing of magnetic field. A qualitative comparison with solar observations is also presented.

  4. Cranked Hartree-Fock-Bogoliubov calculation for rotating Bose-Einstein condensates

    SciTech Connect (OSTI)

    Hamamoto, Nobukuni; Oi, Makito; Onishi, Naoki

    2007-06-15

    A rotating bosonic many-body system in a harmonic trap is studied with the three-dimensional cranked Hartree-Fock-Bogoliubov method at zero temperature, which has been applied to nuclear many-body systems at high spin. This method is a variational method extended from Hartree-Fock theory, which can treat the pairing correlations in a self-consistent manner. An advantage of this method is that a finite-range interaction between constituent particles can be used in the calculation, unlike the original Gross-Pitaevskii approach. To demonstrate the validity of our method, we present a calculation for a toy model--that is, a rotating system of ten bosonic particles interacting through the repulsive quadrupole-quadrupole interaction in a harmonic trap. It is found that the yrast states, the lowest-energy states for the given total angular momentum, do not correspond to the Bose-Einstein condensate, except for a few special cases. One such case is a vortex state, which appears when the total angular momentum L is twice the particle number N (i.e., L=2N)

  5. Vortex nucleation in a dissipative variant of the nonlinear Schrödinger equation under rotation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Carretero-González, R.; Kevrekidis, P. G.; Kolokolnikov, T.

    2016-03-01

    In this work, we motivate and explore the dynamics of a dissipative variant of the nonlinear Schrödinger equation under the impact of external rotation. As in the well established Hamiltonian case, the rotation gives rise to the formation of vortices. We show, however, that the most unstable mode leading to this instability scales with an appropriate power of the chemical potential μ of the system, increasing proportionally to μ2/3. The precise form of the relevant formula, obtained through our asymptotic analysis, provides the most unstable mode as a function of the atomic density and the trap strength. We show howmore » these unstable modes typically nucleate a large number of vortices in the periphery of the atomic cloud. However, through a pattern selection mechanism, prompted by symmetry-breaking, only few isolated vortices are pulled in sequentially from the periphery towards the bulk of the cloud resulting in highly symmetric stable vortex configurations with far fewer vortices than the original unstable mode. We conclude that these results may be of relevance to the experimentally tractable realm of finite temperature atomic condensates.« less

  6. Bifurcation analysis of surge and rotating stall in axial flow compressors

    SciTech Connect (OSTI)

    Abed, E.H. ); Houpt, P.K. . Corporate Research and Development Center); Hosny, W.M. . Engine Operability Div.)

    1993-10-01

    The surge and rotating stall post-instability behaviors of axial flow compressors are investigated from a bifurcation-theoretic perspective, using a model and system data presented by Greitzer (1976a). For this model, a sequence of local and global bifurcations of the nonlinear system dynamics is uncovered. This includes a global bifurcation of a pair of large-amplitude periodic solutions. Resulting from this bifurcation are a stable oscillation (surge) and an unstable oscillation (antisurge). The latter oscillation is found to have a deciding significance regarding the particular post-instability behavior experienced by the compressor. These results are used to reconstruct Greitzer's (1976b) findings regarding the manner in which post-instability behavior depends on system parameters. Although the model does not directly reflect non axisymmetric dynamics, use of a steady-state compressor characteristic approximating the measured characteristic of Greitzer (1976a) is found to result in conclusions that compare well with observation. Thus, the paper gives a convenient and simple explanation of the boundary between surge and rotating stall behaviors, without the use of more intricate models and analyses including non axisymmetric flow dynamics.

  7. EVIDENCE FOR ROTATIONAL MOTIONS IN THE FEET OF A QUIESCENT SOLAR PROMINENCE

    SciTech Connect (OSTI)

    Orozco Suarez, D.; Asensio Ramos, A.; Trujillo Bueno, J.

    2012-12-20

    We present observational evidence of apparent plasma rotational motions in the feet of a solar prominence. Our study is based on spectroscopic observations taken in the He I 1083.0 nm multiplet with the Tenerife Infrared Polarimeter attached to the German Vacuum Tower Telescope. We recorded a time sequence of spectra with 34 s cadence placing the slit of the spectrograph almost parallel to the solar limb and crossing two feet of an intermediate size, quiescent hedgerow prominence. The data show opposite Doppler shifts, {+-}6 km s{sup -1}, at the edges of the prominence feet. We argue that these shifts may be interpreted as prominence plasma rotating counterclockwise around the vertical axis to the solar surface as viewed from above. The evolution of the prominence seen in EUV images taken with the Solar Dynamics Observatory provided us with clues to interpret the results as swirling motions. Moreover, time-distance images taken far from the central wavelength show plasma structures moving parallel to the solar limb with velocities of about 10-15 km s{sup -1}. Finally, the shapes of the observed intensity profiles suggest the presence of, at least, two components at some locations at the edges of the prominence feet. One of them is typically Doppler shifted (up to {approx}20 km s{sup -1}) with respect to the other, thus suggesting the existence of supersonic counter-streaming flows along the line of sight.

  8. Plasma rotation, dynamo, and nonlinear coupling in the reversed field pinch

    SciTech Connect (OSTI)

    Prager, S.C.; Almagri, A.F.; Cekic, M.

    1995-07-01

    Two important effects of MHD fluctuations in the RFP and tokamak are current generation (the dynamo effect) and mode locking. In the T1 and MST RFP experiments new results reveal the mode dynamics underlying these phenomena. In T1 the effect of specific magnetic Fourier modes on the current density profile is evident. In MST, the MHD dynamo term ({delta}v x {delta}B) is measured in the plasma edge, and found to account for the time dependence of the edge current throughout a sawtooth cycle. As edge resistivity is increased in T1 the fluctuation amplitude increases to maintain the dynamo-driven current, as expected from MHD computation. The modes responsible for the dynamo often lock to the local magnetic field error at the vertical cut in MST. The plasma rotation velocity has been measured with a fast Doppler spectrometer to a time resolution of 1 {mu}s. The plasma rotation and mode phase velocity are remarkably well-correlated, with both slowing, in the presence of an impulsive field error, in a 100 {mu}s timescale.

  9. Rotational relaxation in molecular hydrogen and deuterium: Theory versus acoustic experiments

    SciTech Connect (OSTI)

    Montero, S.; Pérez-Ríos, J.

    2014-09-21

    An explicit formulation of the rotational relaxation time in terms of state-to-state rate coefficients associated to inelastic collisions is reported. The state-to-state rates needed for the detailed interpretation of relaxation in H{sub 2} and D{sub 2}, including isotopic variant mixtures, have been calculated by solving the close-coupling Schrödinger equations using the H{sub 2}–H{sub 2} potential energy surface by Diep and Johnson [J. Chem. Phys. 112, 4465 (2000)]. Relaxation related quantities (rotational effective cross section, bulk viscosity, relaxation time, and collision number) calculated from first principles agree reasonably well with acoustic absorption experimental data on H{sub 2} and D{sub 2} between 30 and 293 K. This result confirms at once the proposed formulation, and the validation of the H{sub 2}–H{sub 2} potential energy surface employed, since no approximations have been introduced in the dynamics. Accordingly, the state-to-state rates derived from Diep and Johnson potential energy surface appear to be overestimated by up to 10% for H{sub 2}, and up to 30% for D{sub 2} at T = 300 K, showing a better agreement at lower temperatures.

  10. Refined rotational period, pole solution, and shape model for (3200) Phaethon

    SciTech Connect (OSTI)

    Ansdell, Megan; Meech, Karen J.; Kaluna, Heather; Hainaut, Olivier; Buie, Marc W.; Bauer, James; Dundon, Luke

    2014-09-20

    (3200) Phaethon exhibits both comet- and asteroid-like properties, suggesting it could be a rare transitional object such as a dormant comet or previously volatile-rich asteroid. This justifies detailed study of (3200) Phaethon's physical properties as a better understanding of asteroid-comet transition objects can provide insight into minor body evolution. We therefore acquired time series photometry of (3200) Phaethon over 15 nights from 1994 to 2013, primarily using the Tektronix 2048 2048 pixel CCD on the University of Hawaii 2.2 m telescope. We utilized light curve inversion to (1) refine (3200) Phaethon's rotational period to P = 3.6032 0.0008 hr; (2) estimate a rotational pole orientation of ? = +85 13 and ? = 20 10; and (3) derive a shape model. We also used our extensive light curve data set to estimate the slope parameter of (3200) Phaethon's phase curve as G ? 0.06, consistent with C-type asteroids. We discuss how this highly oblique pole orientation with a negative ecliptic latitude supports previous evidence for (3200) Phaethon's origin in the inner main asteroid belt as well as the potential for deeply buried volatiles fueling impulsive yet rare cometary outbursts.

  11. Rotatable spin-polarized electron source for inverse-photoemission experiments

    SciTech Connect (OSTI)

    Stolwijk, S. D. Wortelen, H.; Schmidt, A. B.; Donath, M.

    2014-01-15

    We present a ROtatable Spin-polarized Electron source (ROSE) for the use in spin- and angle-resolved inverse-photoemission (SR-IPE) experiments. A key feature of the ROSE is a variable direction of the transversal electron beam polarization. As a result, the inverse-photoemission experiment becomes sensitive to two orthogonal in-plane polarization directions, and, for nonnormal electron incidence, to the out-of-plane polarization component. We characterize the ROSE and test its performance on the basis of SR-IPE experiments. Measurements on magnetized Ni films on W(110) serve as a reference to demonstrate the variable spin sensitivity. Moreover, investigations of the unoccupied spin-dependent surface electronic structure of Tl/Si(111) highlight the capability to analyze complex phenomena like spin rotations in momentum space. Essentially, the ROSE opens the way to further studies on complex spin-dependent effects in the field of surface magnetism and spin-orbit interaction at surfaces.

  12. Vortices in a rotating two-component Bose–Einstein condensate with tunable interactions and harmonic potential

    SciTech Connect (OSTI)

    Zhang, Xiao-Fei; Du, Zhi-Jing; Tan, Ren-Bing; Dong, Rui-Fang; Chang, Hong; Zhang, Shou-Gang

    2014-07-15

    We consider a pair of coupled nonlinear Schrödinger equations modeling a rotating two-component Bose–Einstein condensate with tunable interactions and harmonic potential, with emphasis on the structure of vortex states by varying the strength of inter-component interaction, rotational frequency, and the aspect ratio of the harmonic potential. Our results show that the inter-component interaction greatly enhances the effect of rotation. For the case of isotropic harmonic potential and small inter-component interaction, the initial vortex structure remains unchanged. As the ratio of inter- to intra-component interactions increases, each component undergoes a transition from a vortex lattice (vortex line) in an isotropic (anisotropic) harmonic potential to an alternatively arranged stripe pattern, and eventually to the interwoven “serpentine” vortex sheets. Moreover, in the case of anisotropic harmonic potential the system can develop to a rotating droplet structure. -- Highlights: •Different vortex structures are obtained within the full parameter space. •Effects of system parameters on the ground state structure are discussed. •Phase transition between different vortex structures is also examined. •Present one possible way to obtain the rotating droplet structure. •Provide many possibilities to manipulate vortex in two-component BEC.

  13. THE CONTRACTION OF OVERLYING CORONAL LOOP AND THE ROTATING MOTION OF A SIGMOID FILAMENT DURING ITS ERUPTION

    SciTech Connect (OSTI)

    Yan, X. L.; Qu, Z. Q.; Xue, Z. K.; Deng, L. H.; Ma, L.; Kong, D. F.; Liu, J. H.

    2013-06-15

    We present an observation of overlying coronal loop contraction and rotating motion of the sigmoid filament during its eruption on 2012 May 22 observed by the Solar Dynamics Observatory (SDO). Our results show that the twist can be transported into the filament from the lower atmosphere to the higher atmosphere. The successive contraction of the coronal loops was due to a suddenly reduced magnetic pressure underneath the filament, which was caused by the rising of the filament. Before the sigmoid filament eruption, there was a counterclockwise flow in the photosphere at the right feet of the filament and the contraction loops and a convergence flow at the left foot of the filament. The hot and cool materials have inverse motion along the filament before the filament eruption. Moreover, two coronal loops overlying the filament first experienced brightening, expansion, and contraction successively. At the beginning of the rising and rotation of the left part of the filament, the second coronal loop exhibited rapid contraction. The top of the second coronal loop also showed counterclockwise rotation during the contraction process. After the contraction of the second loop, the left part of the filament rotated counterclockwise and expanded toward the right of NOAA AR 11485. During the filament expansion, the right part of the filament also exhibited counterclockwise rotation like a tornado.

  14. 4 K to 20 K rotational-cooling magnetic refrigerator capable of 1-mW to >1-W operation

    SciTech Connect (OSTI)

    Barclay, J.A.

    1980-02-01

    The low-temperature, magnetic entropy of certain single-crystal paramagnetic materials, such as DyPO/sub 4/, changes dramatically as the crystal rotates in a magnetic field. A new magnetic refrigerator design based on the anisotropic nature of such materials is presented. The key advantages of the rotational-cooling concept are (1) a single, rotary motion is required, (2) magnetic field shaping is not a problem because the entire working material is in a constant field, and (3) the refrigerator can be smaller than comparable magnetic refrigerators because the working material is entirely inside the magnet at all times. The main disadvantage of the rotational-cooling concept is that small-dimension single crystals are required.

  15. Faraday rotation limits on a primordial magnetic field from Wilkinson Microwave Anisotropy Probe five-year data

    SciTech Connect (OSTI)

    Kahniashvili, Tina [Department of Physics and McWilliams Center for Cosmology, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Department of Physics, Laurentian University, Ramsey Lake Road, Sudbury, ON P3E 2C6 (Canada); National Abastumani Astrophysical Observatory, Ilia Chavchavadze State University, 2A Kazbegi Ave, Tbilisi, GE-0160 (Georgia); Maravin, Yurii [Department of Physics, Kansas State University, 116 Cardwell Hall, Manhattan, Kansas 66506 (United States); Kosowsky, Arthur [Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, Pennsylvania 15260 (United States)

    2009-07-15

    A primordial magnetic field in the early universe will cause Faraday rotation of the linear polarization of the cosmic microwave background generated via Compton scattering at the surface of last scattering. This rotation induces a nonzero parity-odd (B-mode) polarization component. The Wilkinson Microwave Anisotropy Probe 5-year data puts an upper limit on the magnitude of the B-polarization power spectrum; assuming that the B-polarization signal is totally due to the Faraday rotation effect, the upper limits on the comoving amplitude of a primordial stochastic magnetic field range from 6x10{sup -8} to 2x10{sup -6} G on a comoving length scale of 1 Mpc, depending on the power spectrum of the magnetic field.

  16. Extension of the flow-rate-of-strain tensor formulation of plasma rotation theory to non-axisymmetric tokamaks

    SciTech Connect (OSTI)

    Stacey, W. M.; Bae, C.

    2015-06-15

    A systematic formalism for the calculation of rotation in non-axisymmetric tokamaks with 3D magnetic fields is described. The Braginskii Ωτ-ordered viscous stress tensor formalism, generalized to accommodate non-axisymmetric 3D magnetic fields in general toroidal flux surface geometry, and the resulting fluid moment equations provide a systematic formalism for the calculation of toroidal and poloidal rotation and radial ion flow in tokamaks in the presence of various non-axisymmetric “neoclassical toroidal viscosity” mechanisms. The relation among rotation velocities, radial ion particle flux, ion orbit loss, and radial electric field is discussed, and the possibility of controlling these quantities by producing externally controllable toroidal and/or poloidal currents in the edge plasma for this purpose is suggested for future investigation.

  17. Control of linear modes in cylindrical resistive magnetohydrodynamics with a resistive wall, plasma rotation, and complex gain

    SciTech Connect (OSTI)

    Brennan, D. P.; Finn, J. M.

    2014-10-15

    Feedback stabilization of magnetohydrodynamic (MHD) modes in a tokamak is studied in a cylindrical model with a resistive wall, plasma resistivity, viscosity, and toroidal rotation. The control is based on a linear combination of the normal and tangential components of the magnetic field just inside the resistive wall. The feedback includes complex gain, for both the normal and for the tangential components, and it is known that the imaginary part of the feedback for the former is equivalent to plasma rotation [J. M. Finn and L. Chacon, Phys. Plasmas 11, 1866 (2004)]. The work includes (1) analysis with a reduced resistive MHD model for a tokamak with finite ? and with stepfunction current density and pressure profiles, and (2) computations with a full compressible visco-resistive MHD model with smooth decreasing profiles of current density and pressure. The equilibria are stable for ??=?0 and the marginal stability values ?{sub rp,rw}?rotation stabilizes below ?{sub rp,iw} because rotation suppresses the diffusion of flux from the plasma out through the wall and, more surprisingly, (b) rotation or imaginary gain with normal sensors destabilizes above ?{sub rp,iw} because it prevents the feedback flux from entering the plasma through the resistive wall to form a virtual wall. A method of using complex gain G{sub i} to optimize in the presence of rotation in this regime with ??>??{sub rp,iw} is presented. The effect of imaginary gain with tangential sensors is more complicated but essentially destabilizes above and below ?{sub rp,iw}.

  18. AmeriFlux US-Ne3 Mead - rainfed maize-soybean rotation site

    SciTech Connect (OSTI)

    Suyker, Andy

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Ne3 Mead - rainfed maize-soybean rotation site. Site Description - The study site is one of three fields (all located within 1.6 km of each other) at the University of Nebraska Agricultural Research and Development Center near Mead, Nebraska. While the other two sites are equipped with irrigation systems, this site relies on rainfall. A tillage operation (disking) was done just prior to the 2001 planting to homogenize the top 0.1 m of soil, incorporate P and K fertilizers, as well as previously accumulated surface residues. Since initiation of the study in 2001, this site has been under no-till management.

  19. Chaos concepts as diagnostic tools for assessing rotating machinery vibration signatures

    SciTech Connect (OSTI)

    Adams, M.L.; Loparo, K.A.

    1996-06-01

    Chaos content in measured vibration signals is of some practical importance in rotordynamical systems. Of particular interest is the relationship between the occurrence of determinsite chaos and the diagnosis of mechanical failures in rotating machinery. Two nonlinear rotordynamical systems were studied using simulation and various forms of subharmonic, quasiperiodic and chaotic vibrations were observed. Different routes into and out of chaos show important signs for wear assessment and failure prediction. Experimental test facilities are currently under development and the next steps involve experimental verification of the simulation results and the development of signal processing techniques for extracting the dynamical features of the vibration signatures from measured time series data. {copyright} {ital 1996 American Institute of Physics.}

  20. A remarkable shape-catalytic effect of confinement on the rotational isomerization of small hydrocarbons

    SciTech Connect (OSTI)

    Santiso, Erik E; Gubbins, Keith E; Buongiorno Nardelli, Marco

    2008-01-01

    As part of an effort to understand the effect of confinement by porous carbons on chemical reactions, we have carried out density functional theory calculations on the rotational isomerization of three four-membered hydrocarbons: n-butane, 1-butene, and 1,3-butadiene. Our results show that the interactions with the carbon walls cause a dramatic change on the potential energy surface for pore sizes comparable to the molecular dimensions. The porous material enhances or hinders reactions depending on how similar is the shape of the transition state to the shape of the confining material. The structure of the stable states and their equilibrium distributions are also drastically modified by confinement. Our results are consistent with a doubly exponential behavior of the reaction rates as a function of pore size, illustrating how the shape of a catalytic support can dramatically change the efficiency of a catalyst. (51 refs.)

  1. Rotationally resolved spectroscopy of a librational fundamental band of hydrogen fluoride tetramer

    SciTech Connect (OSTI)

    Blake, Thomas A.; Sharpe, Steven W.; Xantheas, Sotiris S.

    2000-07-08

    The rotationally resolved spectrum of a fundamental band of hydrogen fluoride tetramer has been recorded using a pulsed slit-jet, diode laser spectrometer. The band has a parallel rotational structure and is assigned as the H-F out-of-plane libration fundamental with A{sub u} symmetry. Ninety-five ground state combination differences were fit to a symmetric top Hamiltonian to give the following ground state rotational constants: B{sup ''}=0.132 081(7) cm{sup -1}, D{sub J}{sup ''}=7.1(7)x10{sup -7} cm{sup -1}, D{sub JK}{sup ''}=-9(2)x10{sup -7} cm{sup -1}, H{sub JJJ}{sup ''}=6(2)x10{sup -10} cm{sup -1}, H{sub JJK}{sup ''}=9(7)x10{sup -10} cm{sup -1}, H{sub JKK}{sup ''}=-1.3(8)x10{sup -10} cm{sup -1}. A total of 190 transitions were fit to determine the upper state spectroscopic constants: v{sub 4}=714.7849(1) cm{sup -1}, B{sup '}=0.129 634(5) cm{sup -1}, {delta}(C-B)=0.001 344 cm{sup -1}, D{sub J}{sup '}=6.4(5)x10{sup -7} cm{sup -1}, D{sub JK}{sup '}=-4.5(6)x10{sup -7} cm{sup -1}, {delta}D{sub K}=2.92(8)x10{sup -6} cm{sup -1}, H{sub JJJ}{sup '}=3(1)x10{sup -10} cm{sup -1}, H{sub JKK}{sup '}=-1.55(6)x10{sup -8} cm{sup -1}; {delta}H{sub KKK}=-4.65(6)x10{sup -8} cm{sup -1}. Furthermore, a perpendicular band centered at 752.7 cm{sup -1} was observed. The band has a rotational line spacing that gives an approximate B{sup ''} value of 0.132 cm{sup -1}; it has been assigned as the E{sub u} symmetry, H-F in-plane libration fundamental of the HF tetramer. Finally, a parallel band was observed at 741.0 cm{sup -1} with B{sup ''}=0.076 cm{sup -1} and has been assigned as the A{sup ''} symmetry, H-F out-of-plane libration fundamental of the HF pentamer. Structural parameters and harmonic vibrational frequencies are estimated from first-principles, correlated MP2 and CCSD(T) calculations. These are the largest calculations performed to date for this system with respect to both orbital basis set and level of electron correlation. The CCSD(T) harmonic frequencies are, in particular

  2. Rotation commensurate echo of asymmetric molecules—Molecular fingerprints in the time domain

    SciTech Connect (OSTI)

    Chesnokov, E. N.; Kubarev, V. V.; Koshlyakov, P. V.

    2014-12-29

    Using the pulses of terahertz free electron laser and ultra-fast Schottky diode detectors, we observed the coherent transients within a free induction decay of gaseous nitrogen dioxide NO{sub 2}. The laser excited different sub-bands of rotation spectra of NO{sub 2} containing about 50–70 lines. The free induction signal continued more than 30 ns and consisted of many echo-like bursts duration about 0.2 ns. Unlike the similar effect observed previously for linear and symmetric top molecules, the sequence of echo bursts is not periodic. The values for delay of individual echo are stable, and the set of these delays can be considered as a “molecular fingerprint” in the time domain.

  3. Galaxy luminosity function and Tully-Fisher relation: reconciled through rotation-curve studies

    SciTech Connect (OSTI)

    Cattaneo, Andrea; Salucci, Paolo; Papastergis, Emmanouil E-mail: salucci@sissa.it

    2014-03-10

    The relation between galaxy luminosity L and halo virial velocity v {sub vir} required to fit the galaxy luminosity function differs from the observed Tully-Fisher relation between L and disk speed v {sub rot}. Because of this, the problem of reproducing the galaxy luminosity function and the Tully-Fisher relation simultaneously has plagued semianalytic models since their inception. Here we study the relation between v {sub rot} and v {sub vir} by fitting observational average rotation curves of disk galaxies binned in luminosity. We show that the v {sub rot}-v {sub vir} relation that we obtain in this way can fully account for this seeming inconsistency. Therefore, the reconciliation of the luminosity function with the Tully-Fisher relation rests on the complex dependence of v {sub rot} on v {sub vir}, which arises because the ratio of stellar mass to dark matter mass is a strong function of halo mass.

  4. Why is there a dearth of close-in planets around fast-rotating stars?

    SciTech Connect (OSTI)

    Teitler, Seth; Knigl, Arieh E-mail: akonigl@uchicago.edu

    2014-05-10

    We propose that the reported dearth of Kepler objects of interest (KOIs) with orbital periods P {sub orb} ? 2-3 days around stars with rotation periods P {sub rot} ? 5-10 days can be attributed to tidal ingestion of close-in planets by their host stars. We show that the planet distribution in this region of the log P {sub orb}-log P {sub rot} plane is qualitatively reproduced with a model that incorporates tidal interaction and magnetic braking as well as the dependence on the stellar core-envelope coupling timescale. We demonstrate the consistency of this scenario with the inferred break in the P {sub orb} distribution of close-in KOIs and point out a potentially testable prediction of this interpretation.

  5. Sun-Relative Pointing for Dual-Axis Solar Trackers Employing Azimuth and Elevation Rotations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Riley, Daniel; Hansen, Clifford W.

    2014-12-30

    Dual axis trackers employing azimuth and elevation rotations are common in the field of photovoltaic (PV) energy generation. Accurate sun-tracking algorithms are widely available. However, a steering algorithm has not been available to accurately point the tracker away from the sun such that a vector projection of the sun beam onto the tracker face falls along a desired path relative to the tracker face. We have developed an algorithm which produces the appropriate azimuth and elevation angles for a dual axis tracker when given the sun position, desired angle of incidence, and the desired projection of the sun beam ontomore » the tracker face. Development of this algorithm was inspired by the need to accurately steer a tracker to desired sun-relative positions in order to better characterize the electro-optical properties of PV and CPV modules.« less

  6. Shot noise of charge current in a quantum dot responded by rotating and oscillating magnetic fields

    SciTech Connect (OSTI)

    Zhao, Hong-Kang Zou, Wei-Ke; Chen, Qiao

    2014-09-07

    We have investigated the shot noise and Fano factor of the dynamic spin-polarized quantum dot under the perturbations of a rotating magnetic field (RMF), and an oscillating magnetic field (OMF) by employing the non-equilibrium Green's function approach. The shot noise is enhanced from sub-Poissonian to super-Poissonian due to the application of RMF and OMF, and it is controlled sensitively by the tilt angle θ of RMF. The magnitude of shot noise increases as the photon energy ℏω of OMF increases, and its valley eventually is reversed to peaks as the photon energy is large enough. Double-peak structure of Fano factor is exhibited as the frequency of OMF increases to cover a large regime. The Zeeman energy μ{sub 0}B{sub 0} acts as an effective gate bias to exhibit resonant behavior, and novel peak emerges associated with the applied OMF.

  7. Stochastic ion heating in a field-reversed configuration geometry by rotating magnetic fields

    SciTech Connect (OSTI)

    Cohen, S. A.; Landsman, A. S.; Glasser, A. H.

    2007-07-15

    Ion heating by application of rotating magnetic fields (RMFs) to a prolate field-reversed configuration (FRC) is explored by analytical and numerical techniques. For odd-parity RMFs (RMF{sub o}), perturbation analysis shows ions in figure-8 orbits gain energy at resonances of the RMF{sub o} frequency {omega}{sub R}, with the figure-8 orbital frequency {omega}. Since figure-8 orbits tend to gain the most energy from the RMF and are unlikely to escape in the cusp region (where most losses occur), they are optimal candidates for rapid stochastic heating, as compared to cyclotron and betatron orbits. Comparisons are made between heating caused by even- and odd-parity RMFs and between heating in currently operating and in reactor-scale FRC devices.

  8. Stochastic Ion Heating in a Field-reversed Configuration Geometry by Rotating Magnetic Fields

    SciTech Connect (OSTI)

    S.A. Cohen, A.S. Landsman, and A.H. Glasser

    2007-06-25

    Ion heating by application of rotating magnetic fields (RMF) to a prolate field-reversed configuration(FRC) is explored by analytical and numerical techniques. For odd-parity RMF (RMFo), perturbation analysis shows ions in figure-8 orbits gain energy at resonances of the RMFo frequency, ωR, with the figure-8 orbital frequency, ω. Since figure-8 orbits tend to gain the most energy from the RMF and are unlikely to escape in the cusp region (where most losses occur), they are optimal candidates for rapid stochastic heating, as compared to cyclotron and betatron orbits. Comparisons are made between heating caused by even- and odd-parity RMFs and between heating in currently operating and in reactor-scale FRC devices.

  9. Thermodynamics of charged rotating black branes in Brans-Dicke theory with quadratic scalar field potential

    SciTech Connect (OSTI)

    Dehghani, M. H.; Pakravan, J.; Hendi, S. H.

    2006-11-15

    We construct a class of charged rotating solutions in (n+1)-dimensional Maxwell-Brans-Dicke theory with flat horizon in the presence of a quadratic potential and investigate their properties. These solutions are neither asymptotically flat nor (anti)-de Sitter. We find that these solutions can present black brane, with inner and outer event horizons, an extreme black brane or a naked singularity provided the parameters of the solutions are chosen suitably. We compute the finite Euclidean action through the use of counterterm method, and obtain the conserved and thermodynamic quantities by using the relation between the action and free energy in grand-canonical ensemble. We find that these quantities satisfy the first law of thermodynamics, and the entropy does not follow the area law.

  10. Design of a Rotatable Copper Collimator for the LHC Phase II Collimation Upgrade

    SciTech Connect (OSTI)

    Smith, Jeffrey Claiborne; Doyle, Eric; Keller, Lewis; Lundgren, Steven; Markiewicz, Thomas Walter; Lari, Luisella; /LPHE, Lausanne

    2010-02-15

    The Phase II upgrade to the LHC collimation system calls for complementing the robust Phase I graphite collimators with high Z, low impedance Phase II collimators. The design for the collimation upgrade has not been finalized. One option is to use metallic rotatable collimators and this design will be discussed here. The Phase II collimators must be robust in various operating conditions and accident scenarios. Design issues include: (1) Collimator jaw deflection and sagitta due to heating must be small when operated in the steady state condition, (2) Collimator jaws must withstand transitory periods of high beam impaction with no permanent damage, (3) Jaws must recover from accident scenario where up to 8 full intensity beam pulses impact on the jaw surface and (4) The beam impedance contribution due to the collimators must be small to minimize coherent beam instabilities.

  11. Prototype Testing for a Copper Rotatable Collimator for the LHC Collimation Upgrade

    SciTech Connect (OSTI)

    Smith, Jeffrey Claiborne; Anzalone, Gene; Doyle, Eric; Keller, Lewis; Lundgren, Steven; Markiewicz, Thomas Walter; Rogers, Reggie; /SLAC

    2009-01-20

    The Phase II upgrade to the LHC collimation system calls for complementing the robust Phase I graphite collimators with high Z Phase II collimators. The design for the collimation upgrade has not been finalized. One option is to use metallic rotatable collimators and testing of this design will be discussed here. The Phase II collimators must be robust in various operating conditions and accident scenarios. A prototype collimator jaw referred to as RC0 has been tested for both mechanical and thermal compliance with the design goals. Thermal expansion bench-top tests are compared to ANSYS simulation results. The prototype has also been tested in vacuum bake-out to confirm compliance with the LHC vacuum spec. CMM equipment has been used to verify the flatness of the jaw surface after heat tests and bake-out.

  12. Sun-Relative Pointing for Dual-Axis Solar Trackers Employing Azimuth and Elevation Rotations

    SciTech Connect (OSTI)

    Riley, Daniel; Hansen, Clifford W.

    2014-12-30

    Dual axis trackers employing azimuth and elevation rotations are common in the field of photovoltaic (PV) energy generation. Accurate sun-tracking algorithms are widely available. However, a steering algorithm has not been available to accurately point the tracker away from the sun such that a vector projection of the sun beam onto the tracker face falls along a desired path relative to the tracker face. We have developed an algorithm which produces the appropriate azimuth and elevation angles for a dual axis tracker when given the sun position, desired angle of incidence, and the desired projection of the sun beam onto the tracker face. Development of this algorithm was inspired by the need to accurately steer a tracker to desired sun-relative positions in order to better characterize the electro-optical properties of PV and CPV modules.

  13. Contra-rotating homopolar motor-generator for energy storage and return

    DOE Patents [OSTI]

    Kustom, Robert L.; Wehrle, Robert B.

    1978-01-01

    An apparatus for receiving electrical energy in amounts of the order of hundreds of megajoules, converting the electrical energy to mechanical energy for storage, and delivering the stored energy as electrical energy in times of the order of a second comprises a sequence of stacked electrically conducting cylindrical shells having a common axis. The conducting shells are free to rotate and are separated by stationary insulating cylindrical shells. Adjacent conducting shells are connected electrically by brushes at the edges and a radial magnetic field is caused to pass through the conductors. The apparatus permits the reversal in a plasma heating coil of electric currents of amplitudes up to 100,000 amperes in a time of the order of a second.

  14. BPM Design and Impedance Considerations for a Rotatable Collimator for the LHC Collimation Upgrade

    SciTech Connect (OSTI)

    Smith, Jeffrey Claiborne; Keller, Lewis; Lundgren, Steven; Markiewicz, Thomas; Young, Andrew; /SLAC

    2010-08-26

    The Phase II upgrade to the LHC collimation system calls for complementing the 30 high robust Phase I graphite secondary collimators with 30 high Z Phase II collimators. This paper reports on BPM and impedance considerations and measurements of the integrated BPMs in the prototype rotatable collimator to be installed in the Super Proton Synchrotron (SPS) at CERN. The BPMs are necessary to align the jaws with the beam. Without careful design the beam impedance can result in unacceptable heating of the chamber wall or beam instabilities. The impedance measurements involve utilizing both a single displaced wire and two wires excited in opposite phase to disentangle the driving and detuning transverse impedances. Trapped mode resonances and longitudinal impedance are to also be measured and compared with simulations. These measurements, when completed, will demonstrate the device is fully operational and has the impedance characteristics and BPM performance acceptable for installation in the SPS.

  15. Analytical solutions describing the operation of a rotating magnetic field transducer

    SciTech Connect (OSTI)

    Savin, A.; Grimberg, R.; Mihalache, O.

    1997-01-01

    This work presents the analytical solutions describing the operation of a rotating magnetic field transducer used in the eddy current defectoscopy for detecting the long flaws situated parallelly to the inspected piece generatrix. The method uses the expanding of the real transducer`s three-phase system into an infinite sequence of axial and longitudinal currents whose intensity is given by a Fourier expansion, estimating the electromotive voltage induced in the transducer. By solving the equation of diffusion for the three media and considering the boundary conditions, the vector magnetic potential is determined for each medium. This work also presents the most important theoretical parameters of the transducer, as well as the experimental graphs obtained for concrete cases of the transducer`s applications.

  16. AC field measurements of Fermilab Booster correctors using a rotating coil system

    SciTech Connect (OSTI)

    Velev, G.V.; DiMarco, J.; Harding, D.J.; Kashikhin, V.; Lamm, M.; Makulski, A.; Orris, D.; Schlabach, P.; Sylvester, C.; Tartaglia, M.; Tompkins, J.; /Fermilab

    2006-07-01

    The first prototype of a new corrector package for the Fermilab Booster Synchrotron is presently in production. This water-cooled package includes normal and skew dipole, quadrupole and sextupole elements to control orbit, tune and chromaticity of the beam over the full range of Booster energies (0.4-8 GeV). These correctors operate at the 15 Hz excitation cycle of the main synchrotron magnets, but must also make more rapid excursions, in some cases even switching polarity in approximately 1 ms at transition crossing. To measure the dynamic field changes during operation, a new method based on a relatively slow rotating coil system is proposed. The method pieces together the measured voltages from successive current cycles to reconstruct the field harmonics. This paper describes the method and presents initial field quality measurements from a Tevatron corrector.

  17. Spin ice: magnetic excitations without monopole signatures using muon spin rotation

    SciTech Connect (OSTI)

    Dunsiger, Sarah [Technical University, Munich, Germany; Aczel, Adam A. [McMaster University; Arguello, Carlos [Columbia University; Dabkowska, H. A. [McMaster University; Dabkowski, A [McMaster University; Du, Mao-Hua [ORNL; Goko, Tatsuo [Columbia University; Javanparast, B [University of Waterloo, Canada; Lin, T [University of Waterloo, Canada; Ning, F. L. [McMaster University; Noad, H. M. [McMaster University; Singh, David J [ORNL; Williams, T.J. [McMaster University; Uemura, Yasutomo J. [Columbia University; Gingras, M.P.J. [University of Waterloo, Canada; Luke, Graeme M. [McMaster University

    2011-01-01

    Theory predicts the low temperature magnetic excitations in spin ices consist of deconfined magnetic charges, or monopoles. A recent transverse-field (TF) muon spin rotation ({mu}SR) experiment [S.T. Bramwell et al., Nature (London) 461 956 (2009)] reports results claiming to be consistent with the temperature and magnetic field dependence anticipated for monopole nucleation - the so-called second Wien effect. We demonstrate via a new series of {mu}SR experiments in Dy{sub 2}Ti{sub 2}O{sub 7} that such an effect is not observable in a TF {mu}SR experiment. Rather, as found in many highly frustrated magnetic materials, we observe spin fluctuations which become temperature independent at low temperatures, behavior which dominates over any possible signature of thermally nucleated monopole excitations.

  18. Nano-electromechanical rotation of graphene and giant enhancement in dielectric anisotropy in a liquid crystal

    SciTech Connect (OSTI)

    Basu, Rajratan Kinnamon, Daniel; Garvey, Alfred

    2015-05-18

    A nematic liquid crystal (LC) is doped with dilute concentrations of pristine monolayer graphene (GP) flakes, and the LC + GP hybrids are found to exhibit a dramatic increase in the dielectric anisotropy. Electric field-dependent conductance studies reveal that the graphene flakes follow the nematic director that mechanically rotates on increasing an applied electric field. Further studies show that the ?? electron stacking, between the graphene's honeycomb structure and the LC's benzene rings, stabilizes pseudo-nematic domains that collectively amplify the dielectric anisotropy by improving the orientational order parameter in the nematic phase. These anisotropic domains interact with the external electric field, resulting in a nonzero dielectric anisotropy in the isotropic phase as well. The enhancement in dielectric anisotropy, due to the LCgraphene coupling, is found to have subsequent positive impacts on the LC's orientational threshold field and elasticity that allows the nematic director to respond quicker on switching the electric field off.

  19. Distribution of ion current density on a rotating spherical cap substrate during ion-assisted deposition

    SciTech Connect (OSTI)

    Marushka, Viktor; Zabeida, Oleg Martinu, Ludvik

    2014-11-01

    The uniformity of ion density is critical for applications relying on the ion assisted deposition technique for the fabrication of the high quality thin films. The authors propose and describe here a method allowing one to calculate the ion density distribution on spherical substrate holders under stationary and rotating conditions for different positions of the ion source. The ion beam shape was approximated by a cos{sup n} function, and the ion current density was represented by a function inversely proportional to the distance from the ion source in accordance with our experimental results. As an example, a calculation of the current density distribution on the spherical cap substrate was performed for a broad beam ion source operated with an anode current of 3?A. The authors propose an approach for process optimization with respect to the ion source position and its inclination, in terms of uniformity and absolute value of the ion current density.

  20. Null geodesics and shadow of a rotating black hole in extended Chern-Simons modified gravity

    SciTech Connect (OSTI)

    Amarilla, Leonardo; Eiroa, Ernesto F.; Giribet, Gaston

    2010-06-15

    The Chern-Simons modification to general relativity in four dimensions consists of adding to the Einstein-Hilbert term a scalar field that couples to the first-class Pontryagin density. In this theory, which has attracted considerable attention recently, the Schwarzschild metric persists as an exact solution, and this is why this model resists several observational constraints. In contrast, the spinning black hole solution of the theory is not given by the Kerr metric but by a modification of it, so far only known for slow rotation and small coupling constant. In the present paper, we show that, in this approximation, the null geodesic equation can be integrated, and this allows us to investigate the shadow cast by a black hole. We discuss how, in addition to the angular momentum of the solution, the coupling to the Chern-Simons term deforms the shape of the shadow.