Sample records for 3-dimensional converted shear

  1. Conducting a 3D Converted Shear Wave Project to Reduce Exploration Risk at Wister, CA

    Broader source: Energy.gov [DOE]

    DOE Geothermal Technologies Peer Review 2010 - Presentation. The primary objective of this project is to conduct a 3C 3D (converted shear wave) seismic survey to reduce exploration risk by characterizing fault and fracture geometrics at Wister, CA.The intent of the proposed program is to use a 3D seismic survey with converted shear waves combined with other available data to site and drill production wells at Wister, a blind geothermal resource.

  2. Conducting a 3D Converted Shear Wave Project to Reduce Exploration...

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

    shear wave) seismic survey to reduce exploration risk by characterizing fault and fracture geometrics at Wister, CA.The intent of the proposed program is to use a 3D seismic...

  3. Conducting a 3D Converted Shear Wave Project to Reduce Exploration...

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

    shear wave) seismic survey to reduce exploration risk by characterizing fault and fracture geometrics at Wister, CA. The intent of the proposed program is to use a 3D seismic...

  4. Performance Analysis of 3-Dimensional Turbo Codes

    E-Print Network [OSTI]

    Rosnes, Eirik

    2011-01-01T23:59:59.000Z

    In this work, we consider the minimum distance properties and convergence thresholds of 3-dimensional turbo codes (3D-TCs), recently introduced by Berrou et al.. Here, we consider binary 3D-TCs while the original work of Berrou et al. considered double-binary codes. In the first part of the paper, the minimum distance properties are analyzed from an ensemble perspective, both in the finite-length regime and in the asymptotic case of large block lengths. In particular, we analyze the asymptotic weight distribution of 3D-TCs and show numerically that their typical minimum distance dmin may, depending on the specific parameters, asymptotically grow linearly with the block length, i.e., the 3D-TC ensemble is asymptotically good for some parameters. In the second part of the paper, we derive some useful upper bounds on the dmin when using quadratic permutation polynomial (QPP) interleavers with a quadratic inverse. Furthermore, we give examples of interleaver lengths where an upper bound appears to be tight. The b...

  5. Thermionic converter

    DOE Patents [OSTI]

    Fitzpatrick, G.O.

    1987-05-19T23:59:59.000Z

    A thermionic converter is set forth which includes an envelope having an electron collector structure attached adjacent to a wall. An electron emitter structure is positioned adjacent the collector structure and spaced apart from opposite wall. The emitter and collector structures are in a common chamber. The emitter structure is heated substantially only by thermal radiation. Very small interelectrode gaps can be maintained utilizing the thermionic converter whereby increased efficiency results. 10 figs.

  6. 3-DIMENSIONAL COMPACT DISC (CD) MICROFLUIDIC PLATFORM Presented to the

    E-Print Network [OSTI]

    Kassegne, Samuel Kinde

    3-DIMENSIONAL COMPACT DISC (CD) MICROFLUIDIC PLATFORM _______________ A Thesis Presented OF THE THESIS 3-Dimensional Compact Disc (CD) Microfluidic Platform by Nitin Edmund Harwood Master of Science in a compact disc (CD) microfluidics platform involving two or more layers. The traditional 2-Dimensional

  7. Thermionic converter

    DOE Patents [OSTI]

    Fitzpatrick, Gary O. (Livermore, CA)

    1987-05-19T23:59:59.000Z

    A thermionic converter (10) is set forth which includes an envelope (12) having an electron collector structure (22) attached adjacent to a wall (16). An electron emitter structure (24) is positioned adjacent the collector structure (22) and spaced apart from opposite wall (14). The emitter (24) and collector (22) structures are in a common chamber (20). The emitter structure (24) is heated substantially only by thermal radiation. Very small interelectrode gaps (28) can be maintained utilizing the thermionic converter (10) whereby increased efficiency results.

  8. Thermionic converter

    SciTech Connect (OSTI)

    Fitzpatrick, G.O.

    1987-05-19T23:59:59.000Z

    A thermionic converter is described comprising: an envelope having first and second walls spaced apart from one another. The envelope defines an enclosed chamber; an electron collector structure attached adjacent to the second wall; an electron emitter structure, located adjacent the collector structure and between the collector structure and the first wall. At least a respective one of the collector structure and the emitter structure comprise elements, each of the elements along with a respective other of the collector structure and the emitter structure defining interelectrode gaps at least when the emitter structure is above a selected temperature. The emitter structure is spaced a distance away from the first wall and is positioned to receive substantially only thermal radiation.

  9. Combustion converter design evolution

    SciTech Connect (OSTI)

    Goodale, D.B.; Miskolczy, G.

    1984-08-01T23:59:59.000Z

    The early thermionic converters used hemispherical one-inch-diameter hot shells. They were extensively tested in a natural gas, high-temperature furnace. A converter was life tested for 12,500 hours at emitter temperatures above 1700 K. Two-inch diameter converters with both hemispherical and torispherical shapes were developed next. These converters have been tested in both natural gas-, oil-, and coal-oil slurry-fired environments. A prototype converter for cogeneration applications was also developed using this emitter configuration. A six converter module of cogeneration converters has been constructed.

  10. Heat pulse propagation in chaotic 3-dimensional magnetic fields

    E-Print Network [OSTI]

    D. del-Castillo-Negrete; D. Blazevski

    2014-09-10T23:59:59.000Z

    Heat pulse propagation in $3$-D chaotic magnetic fields is studied by solving the parallel heat transport equation using a Lagrangian-Green's function (LG) method. The LG method provides an efficient and accurate technique that circumvents limitations of finite elements and finite difference methods. The main two problems addressed are: (i) The dependence of the radial transport on the magnetic field stochasticity (controlled by the amplitude of the perturbation, $\\epsilon$); and (ii) The role of reversed shear configurations on pulse propagation. In all the cases considered there are no magnetic flux surfaces. However, radial transport is observed to depend strongly on $\\epsilon$ due to the presence of high-order magnetic islands and Cantori that act as quasi-transport barriers that preclude the radial penetration of heat pulses within physically relevant time scale. The dependence of the magnetic field connection length, $\\ell_B$, on $\\epsilon$ is studied in detail. The decay rate of the temperature maximum, $\\langle T \\rangle_{max}(t)$, the time delay of the temperature response as function of the radius, $\\tau$, and the radial heat flux $\\langle {{\\bf q}\\cdot {\\hat e}_\\psi} \\rangle$, are also studied as functions of the magnetic field stochasticity and $\\ell_B$. In all cases, the scaling of $\\langle T \\rangle_{max}$ with $t$ transitions from sub-diffusive, $\\langle T \\rangle_{max} \\sim t^{-1/4}$, at short times ($\\chi_\\parallel t 10^5$). A strong dependence on $\\epsilon$ is also observed on $\\tau$ and $\\langle {{\\bf q}\\cdot {\\hat e}_\\psi} \\rangle$. The radial propagation of pulses in fully chaotic fields considerably slows down in the shear reversal region and, as a result, $\\tau$, in reversed shear configurations is an order of magnitude longer than the one in monotonic $q$-profiles.

  11. Pseudocodewords of Linear Programming Decoding of 3-Dimensional Turbo Codes

    E-Print Network [OSTI]

    Rosnes, Eirik; Amat, Alexandre Graell i

    2011-01-01T23:59:59.000Z

    In this work, we consider pseudocodewords of (relaxed) linear programming (LP) decoding of 3-dimensional turbo codes (3D-TCs), recently introduced by Berrou et al.. Here, we consider binary 3D-TCs while the original work of Berrou et al. considered double-binary codes. We present a relaxed LP decoder for 3D-TCs, which is an adaptation of the relaxed LP decoder for conventional turbo codes proposed by Feldman in his thesis. The vertices of this relaxed polytope are the pseudocodewords. We show that the support set of any pseudocodeword is a stopping set of iterative decoding of 3D-TCs using maximum a posteriori constituent decoders on the binary erasure channel. Furthermore, we present a numerical study of small block length 3D-TCs, which shows that typically the minimum pseudoweight (on the additive white Gaussian noise (AWGN) channel) is smaller than both the minimum distance and the stopping distance. In particular, we performed an exhaustive search over all interleaver pairs in the 3D-TC based on quadratic...

  12. ITER convertible blanket evaluation

    SciTech Connect (OSTI)

    Wong, C.P.C.; Cheng, E.

    1995-09-01T23:59:59.000Z

    Proposed International Thermonuclear Experimental Reactor (ITER) convertible blankets were reviewed. Key design difficulties were identified. A new particle filter concept is introduced and key performance parameters estimated. Results show that this particle filter concept can satisfy all of the convertible blanket design requirements except the generic issue of Be blanket lifetime. If the convertible blanket is an acceptable approach for ITER operation, this particle filter option should be a strong candidate.

  13. Interleaved power converter

    DOE Patents [OSTI]

    Zhu, Lizhi (Canton, MI)

    2007-11-13T23:59:59.000Z

    A power converter architecture interleaves full bridge converters to alleviate thermal management problems in high current applications, and may, for example, double the output power capability while reducing parts count and costs. For example, one phase of a three phase inverter is shared between two transformers, which provide power to a rectifier such as a current doubler rectifier to provide two full bridge DC/DC converters with three rather than four high voltage inverter legs.

  14. Universal thermochemical energy converter

    DOE Patents [OSTI]

    Labinov, Solomon Davidovich (Oak Ridge, TN); Sand, James R. (Oak Ridge, TN); Conklin, James C. (Knoxville, TN); VanCoevering, James (Oak Ridge, TN); Courville, George E. (Oak Ridge, TN)

    2001-01-01T23:59:59.000Z

    Disclosed are methods and apparatus for a thermochemical closed cycle employing a polyatomic, chemically active working fluid for converting heat energy into useful work.

  15. WBG Converters and Chargers

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

    * Finish - FY16 * 38 % complete * Reducing onboard battery charger and dc-dc converter cost, weight, and volume * Achieving high efficiency * Overcoming limitations of present...

  16. 3-dimensional imaging system using crystal diffraction lenses

    DOE Patents [OSTI]

    Smither, R.K.

    1999-02-09T23:59:59.000Z

    A device for imaging a plurality of sources of x-ray and gamma-ray radiation is provided. Diffracting crystals are used for focusing the radiation and directing the radiation to a detector which is used for analyzing their addition to collect data as to the location of the source of radiation. A computer is used for converting the data to an image. The invention also provides for a method for imaging x-ray and gamma radiation by supplying a plurality of sources of radiation; focusing the radiation onto a detector; analyzing the focused radiation to collect data as to the type and location of the radiation; and producing an image using the data. 18 figs.

  17. 3-dimensional imaging system using crystal diffraction lenses

    DOE Patents [OSTI]

    Smither, Robert K. (Hinsdale, IL)

    1999-01-01T23:59:59.000Z

    A device for imaging a plurality of sources of x-ray and gamma-ray radiation is provided. Diffracting crystals are used for focussing the radiation and directing the radiation to a detector which is used for analyzing their addition to collect data as to the location of the source of radiation. A computer is used for converting the data to an image. The invention also provides for a method for imaging x-ray and gamma radiation by supplying a plurality of sources of radiation; focussing the radiation onto a detector; analyzing the focused radiation to collect data as to the type and location of the radiation; and producing an image using the data.

  18. Microminiature thermionic converters

    DOE Patents [OSTI]

    King, Donald B. (Albuquerque, NM); Sadwick, Laurence P. (Salt Lake City, UT); Wernsman, Bernard R. (Clairton, PA)

    2001-09-25T23:59:59.000Z

    Microminiature thermionic converts (MTCs) having high energy-conversion efficiencies and variable operating temperatures. Methods of manufacturing those converters using semiconductor integrated circuit fabrication and micromachine manufacturing techniques are also disclosed. The MTCs of the invention incorporate cathode to anode spacing of about 1 micron or less and use cathode and anode materials having work functions ranging from about 1 eV to about 3 eV. Existing prior art thermionic converter technology has energy conversion efficiencies ranging from 5-15%. The MTCs of the present invention have maximum efficiencies of just under 30%, and thousands of the devices can be fabricated at modest costs.

  19. Vector generator scan converter

    DOE Patents [OSTI]

    Moore, J.M.; Leighton, J.F.

    1988-02-05T23:59:59.000Z

    High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardware for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold. 7 figs.

  20. Vector generator scan converter

    DOE Patents [OSTI]

    Moore, James M. (Livermore, CA); Leighton, James F. (Livermore, CA)

    1990-01-01T23:59:59.000Z

    High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O (input/output) channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardward for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold.

  1. A 3-dimensional analysis of sight distance on interchange ramps and connectors

    E-Print Network [OSTI]

    Sanchez, Eddie

    1992-01-01T23:59:59.000Z

    A 3-DIMENSIONAL ANALYSIS OF SIGHT DISTANCE ON INTERCHANGE RAMPS AND CONNECTORS A Thesis by EDDIE SANCHEZ Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfdlment of the requiretnents for the degree of MASTER... OF SCIENCE August 1992 Major Subject: Civil Engineering A 3-DIMENSIONAL ANALYSIS OF SIGHT DISTANCE ON INTERCHANGE RAMPS AND CONNECTORS A Thesis by EDDIE SANCHEZ Approved as to style and content by: Raymond A. Krammes (Chair of Committee) N ' n J...

  2. Liquid metal thermal electric converter

    DOE Patents [OSTI]

    Abbin, Joseph P. (Albuquerque, NM); Andraka, Charles E. (Albuquerque, NM); Lukens, Laurance L. (Albuquerque, NM); Moreno, James B. (Albuquerque, NM)

    1989-01-01T23:59:59.000Z

    A liquid metal thermal electric converter which converts heat energy to electrical energy. The design of the liquid metal thermal electric converter incorporates a unique configuration which directs the metal fluid pressure to the outside of the tube which results in the structural loads in the tube to be compressive. A liquid metal thermal electric converter refluxing boiler with series connection of tubes and a multiple cell liquid metal thermal electric converter are also provided.

  3. DC systems with transformerless converters

    SciTech Connect (OSTI)

    Vithayathil, J.J.; Mittlestadt, W. [Bonneville Power Administration, Portland, OR (United States)] [Bonneville Power Administration, Portland, OR (United States); Bjoerklund, P.E. [ABB Power Systems AB, Ludvika (Sweden)] [ABB Power Systems AB, Ludvika (Sweden)

    1995-07-01T23:59:59.000Z

    A technical and economic feasibility study of HVDC systems without converter transformers is presented. The presentation includes proposed solutions to the drawback related to the absence of galvanic separation between the ac and dc systems, if the converter transformers are eliminated. The results show that HVDC systems without converter transformers are both technically and economically feasible. The cost savings can be substantial.

  4. Cycloidal Wave Energy Converter

    SciTech Connect (OSTI)

    Stefan G. Siegel, Ph.D.

    2012-11-30T23:59:59.000Z

    This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will exceed this initial performance estimates. In advancing the Technology Readiness Level (TRL) of this type of wave energy converter from 3 to 4, we find the CycWEC to exceed our initial estimates in terms of hydrodynamic performance. Once fully developed and optimized, it has the potential to not just outperform all other WEC technologies, but to also deliver power at a lower LCOE than competing conventional renewables like wind and solar. Given the large wave power resource both domestically and internationally, this technology has the potential to lead to a large improvement in our ability to produce clean electricity at affordable cost.

  5. Thermionic electric converter

    SciTech Connect (OSTI)

    Davis, E.D.

    1981-12-01T23:59:59.000Z

    A thermionic electric converter is disclosed wherein an externally located heat source causes electrons to be boiled off an electron emissive surface interiorly positioned on one end wall of an evacuated cylindrical chamber. The electrons are electrically focused and accelerated through the interior of an air core induction coil located within a transverse magnetic field, and subsequently are collected on the other end wall of the chamber functioning as a collecting plate. The emf generated in the induction coil by action of the transiting electron stream interacting with the transverse magnetic field is applied to an external circuit to perform work, thereby implementing a direct heat energy to electrical energy conversion.

  6. Solar thermionic energy converter experiment

    SciTech Connect (OSTI)

    Goodale, D.; Lieb, D.; Neale, D.

    1982-08-01T23:59:59.000Z

    A one-inch CVD converter was solar tested in a central receiver heliostat array at the Advanced Components Test Facility at the Georgia Institute of Technology. The test examined heat flux cycling control of the operating point and mounting arrangements. The converter was mounted directly in the solar image with no cavity. The input heat flux was 40-60 W/cm/sup 2/. The converter performance was comparable to combustion measurements made on the same diode. Thermal cycling caused no problems with converter operation. The converter showed no degradation after the test.

  7. Bidirectional buck boost converter

    DOE Patents [OSTI]

    Esser, A.A.M.

    1998-03-31T23:59:59.000Z

    A bidirectional buck boost converter and method of operating the same allows regulation of power flow between first and second voltage sources in which the voltage level at each source is subject to change and power flow is independent of relative voltage levels. In one embodiment, the converter is designed for hard switching while another embodiment implements soft switching of the switching devices. In both embodiments, first and second switching devices are serially coupled between a relatively positive terminal and a relatively negative terminal of a first voltage source with third and fourth switching devices serially coupled between a relatively positive terminal and a relatively negative terminal of a second voltage source. A free-wheeling diode is coupled, respectively, in parallel opposition with respective ones of the switching devices. An inductor is coupled between a junction of the first and second switching devices and a junction of the third and fourth switching devices. Gating pulses supplied by a gating circuit selectively enable operation of the switching devices for transferring power between the voltage sources. In the second embodiment, each switching device is shunted by a capacitor and the switching devices are operated when voltage across the device is substantially zero. 20 figs.

  8. Bacteria in shear flow

    E-Print Network [OSTI]

    Marcos, Ph.D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Bacteria are ubiquitous and play a critical role in many contexts. Their environment is nearly always dynamic due to the prevalence of fluid flow: creeping flow in soil, highly sheared flow in bodily conduits, and turbulent ...

  9. A Uniqueness Theorem of the 3-Dimensional Acoustic Scattering Problem in a Shallow Ocean

    E-Print Network [OSTI]

    A Uniqueness Theorem of the 3-Dimensional Acoustic Scattering Problem in a Shallow Ocean, Minneapolis, MN 55455, USA Abstract This paper shows that under the assumption of the out-going radiation conditions at infinity, the time-harmonic acoustic scattered field off a sound-soft solid in a shallow ocean

  10. Self-powered microthermionic converter

    DOE Patents [OSTI]

    Marshall, Albert C.; King, Donald B.; Zavadil, Kevin R.; Kravitz, Stanley H.; Tigges, Chris P.; Vawter, Gregory A.

    2004-08-10T23:59:59.000Z

    A self-powered microthermionic converter having an internal thermal power source integrated into the microthermionic converter. These converters can have high energy-conversion efficiencies over a range of operating temperatures. Microengineering techniques are used to manufacture the converter. The utilization of an internal thermal power source increases potential for mobility and incorporation into small devices. High energy efficiency is obtained by utilization of micron-scale interelectrode gap spacing. Alpha-particle emitting radioisotopes can be used for the internal thermal power source, such as curium and polonium isotopes.

  11. Thyristor converter simulation and analysis

    SciTech Connect (OSTI)

    Zhang, S.Y.

    1991-01-01T23:59:59.000Z

    In this paper we present a simulation on thyristor converters. The simulation features nonlinearity, non-uniform firing, and the commutations. Several applications such as a current regulation, a converter frequency characteristics analysis, and a power line disturbance analysis will be presented. 4 refs., 4 figs.

  12. Thermionic-photovoltaic energy converter

    SciTech Connect (OSTI)

    Chubb, D. L.

    1985-07-09T23:59:59.000Z

    A thermionic-photovoltaic energy conversion device comprises a thermionic diode mounted within a hollow tubular photovoltaic converter. The thermionic diode maintains a cesium discharge for producing excited atoms that emit line radiation in the wavelength region of 850 nm to 890 nm. The photovoltaic converter is a silicon or galium arsenide photovoltaic cell having bandgap energies in this same wavelength region for optimum cell efficiency.

  13. MT3D: a 3 dimensional magnetotelluric modeling program (user's guide and documentation for Rev. 1)

    SciTech Connect (OSTI)

    Nutter, C.; Wannamaker, P.E.

    1980-11-01T23:59:59.000Z

    MT3D.REV1 is a non-interactive computer program written in FORTRAN to do 3-dimensional magnetotelluric modeling. A 3-D volume integral equation has been adapted to simulate the MT response of a 3D body in the earth. An integro-difference scheme has been incorporated to increase the accuracy. This is a user's guide for MT3D.REV1 on the University of Utah Research Institute's (UURI) PRIME 400 computer operating under PRIMOS IV, Rev. 17.

  14. Converting Biomass to High-Value Feedstocks

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

    Converting Biomass to High-Value Feedstocks Advanced feedstocks play an important role in economically and efficiently converting biomass into bioenergy products. Advanced...

  15. Structural changes in block copolymer solution under shear flow as determined by nonequilibrium molecular dynamics

    E-Print Network [OSTI]

    Igor Rychkov; Kenichi Yoshikawa

    2003-10-06T23:59:59.000Z

    A nonequilibrium molecular dynamics computer simulation on microsegregated solutions of symmetrical diblock copolymers is reported. As the polymer concentration increases, the system undergoes phase transitions in the following order: body centered cubic (BCC) micelles, hexagonal (HEX) cylinders, gyroid (GYR) bicontinuous networks, and lamellae (L), which are the same morphologies that have been reported for block copolymer melts. Structural classification is based on the patterns of the anisotropic static structure factor and characteristic 3-dimensional images. The systems in the BCC micellar ($\\rho\\sigma^{3}=0.3$) and HEX cylindrical ($\\rho\\sigma^{3}=0.4$) phases were then subjected to a steady planar shear flow. In weak shear flow, the segregated domains in both systems tend to rearrange into sliding parallel close-packed layers with their normal in the direction of the shear gradient. At higher shear rates both systems adopt a perpendicular lamellar structure with the normal along the neutral direction. A further increase in the shear rate results in a decrease in lamellar spacing without any further structural transitions. Two critical shear rate values that correspond to the demarcation of different structural behaviors were found.

  16. A thermionic converter success story

    SciTech Connect (OSTI)

    Donovan, B.D.; Lamp, T.R. (Aerospace Power Division, Wright Laboratory Wright-Patterson AFB, OH 45433-6563 (United States)); Ramaligam, M.L. (UES, Inc. 4401 Dayton-Xenia Road, Dayton, OH 45432-1894 (United States))

    1993-01-20T23:59:59.000Z

    This paper summarizes the advanced out-of-core thermionic technology program being managed at Wright Laboratory: The Thermionic Critical Technology (TCT) Investigation. This program has been supported primarily by the United State Air Force for design and fabrication, and supported by Strategic Defense Initiative Organization (SDIO) for performance and life testing efforts. Converter design parameters, specifications, and performance testing data is summarized. Converters fabricated by Loral Electro Optical Systems (Loral EOS) under this program have exceeding performance requirements, and have demonstrated efficiencies as high as 14%.

  17. Power converters for parabolic dishes

    SciTech Connect (OSTI)

    Truscello, V.C.; Williams, A.N.

    1981-01-01T23:59:59.000Z

    The development status of receivers and power conversion units to be used with parabolic dish concentrators is presented. Applications are identified, and the key role played by the power converter element of the collector module is emphasized. The electrical output of the 11-meter-diameter dish modules which are being developed varies up to a maximum of about 25 kilowatts, depending on the thermodynamic cycle of the power converter. Three power conversion units are being developed: an organic Rankine, an air Brayton, and a Stirling. The development program for the receivers and the power conversion units is described in detail.

  18. Charge-pump voltage converter

    DOE Patents [OSTI]

    Brainard, John P. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

    2009-11-03T23:59:59.000Z

    A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

  19. The limited growth of vegetated shear layers

    E-Print Network [OSTI]

    Ghisalberti, M.

    In contrast to free shear layers, which grow continuously downstream, shear layers generated by submerged vegetation grow only to a finite thickness. Because these shear layers are characterized by coherent vortex structures ...

  20. Collector for thermionic energy converter

    SciTech Connect (OSTI)

    Bell, R.L.

    1981-07-21T23:59:59.000Z

    An improved collector is provided for a thermionic energy converter. The collector comprises a p-type layer of a semiconductor material formed on an n-type layer of a semiconductor material. The p-n junction is maintained in a forward biased condition. The electron affinity of the exposed surface of the p-type layer is effectively lowered to a low level near zero by the presence of a work function lowering activator. The dissipation of energy during collection is reduced by the passage of electrons through the p-type layer in the metastable conduction band state. A significant portion of the electron current remains at the potential of the fermi level of the n-type layer rather than dropping to the fermi level of the p-type layer. Less energy is therefore dissipated as heat and a higher net power output is delivered from a thermionic energy converter incorporating the collector.

  1. Portable convertible blast effects shield

    DOE Patents [OSTI]

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A. (Livermore, CA)

    2011-03-15T23:59:59.000Z

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more frusto-conically-tapered telescoping rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration by the friction fit of adjacent pairs of frusto-conically-tapered rings to each other.

  2. Portable convertible blast effects shield

    DOE Patents [OSTI]

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

    2007-05-22T23:59:59.000Z

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  3. Portable convertible blast effects shield

    DOE Patents [OSTI]

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler,; Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

    2010-10-26T23:59:59.000Z

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  4. Development of a 3-Dimensional Dosimetry System for Leksell Gamma Knife-Perfexion

    E-Print Network [OSTI]

    Yoon, KyoungJun; Lee, DoHeui; Cho, ByungChul; Lee, SangWook; Ahn, SeungDo

    2015-01-01T23:59:59.000Z

    The purpose of our study is to develop a new, 3-dimensional dosimetry system to verify the accuracy of dose deliveries in Leksell Gamma Knife-Perfexion TM (LGKP) (Elekta, Norcross, GA, USA). The instrument consists of a moving head phantom, an embedded thin active layer and a CCD camera system and was designed to be mounted to LGKP. As an active material concentrically located in the hemispheric head phantom, we choose Gafchromic EBT3 films and Gd2O2S;Tb phosphor sheets for dosimetric measurements. Also, to compensate the lack of backscatter, we located a 1 cm thick PMMA plate downstream of the active layer. The PMMA plate was transparent for scintillation lights to reach the CCD with 1200x1200 pixels by a 5.2 um pitch. Using this system, three hundred images by a 0.2 mm slice gap were acquired under each of three collimator setups, i.e. 4 mm, 8 mm, and 16 mm, respectively. The 2D projected images taken by CCD camera were compared with the dose distributions measured by EBT3 films in the same conditions. All ...

  5. COMMUNITY ALERT INCIDENT: Catalytic Converter Thefts

    E-Print Network [OSTI]

    Rose, Michael R.

    converter is a part used to reduce the toxicity of emissions from an internal combustion engine. What can

  6. CONVERTIBLE BONDS IN A DEFAULTABLE DIFFUSION MODEL

    E-Print Network [OSTI]

    Jeanblanc, Monique

    CONVERTIBLE BONDS IN A DEFAULTABLE DIFFUSION MODEL Tomasz R. Bielecki Department of Applied Research Grant PS12918. #12;2 Convertible Bonds in a Defaultable Diffusion Model 1 Introduction In [4), such as Convertible Bonds (CB), and we provided a rigorous decomposition of a CB into a bond component and a (game

  7. Auxiliary resonant DC tank converter

    DOE Patents [OSTI]

    Peng, Fang Z. (Knoxville, TN)

    2000-01-01T23:59:59.000Z

    An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

  8. Digital control of HVDC converters

    SciTech Connect (OSTI)

    Pilotto, L.A.S.; Roitman, M.; Alves, J.E.R.

    1989-05-01T23:59:59.000Z

    This paper presents the project of a completely digital HVDC converter controller based on a 16-bit microcomputer. It was decided to achieve as much as possible by software in order to minimize functions performed by external hardware. The presented design comprises software programmed functions such as a PID current control amplifier, voltage dependent current order limiters and an alpha-minimum symmetrization unit, among others. HVDC control principles are briefly reviewed and a detailed description of both the hardware and software structure of the controller is presented. The digital controller was implemented in an HVDC simulator and several dynamic performance tests demonstrated the efficiency of the proposed methodology.

  9. Converting Energy to Medical Progress

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinan antagonist Journal Article: Crystal structureComposite-- Energy,Converting to April 2001 An introduction

  10. Converting Energy to Medical Progress

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity2Workshops01ControllingControls onPolymers -Converting to

  11. Shear shocks in fragile networks

    E-Print Network [OSTI]

    Stephan Ulrich; Nitin Upadhyaya; Bas van Opheusden; Vincenzo Vitelli

    2013-07-29T23:59:59.000Z

    A minimal model for studying the mechanical properties of amorphous solids is a disordered network of point masses connected by unbreakable springs. At a critical value of its mean connectivity, such a network becomes fragile: it undergoes a rigidity transition signaled by a vanishing shear modulus and transverse sound speed. We investigate analytically and numerically the linear and non-linear visco-elastic response of these fragile solids by probing how shear fronts propagate through them. Our approach, that we tentatively label shear front rheology, provides an alternative route to standard oscillatory rheology. In the linear regime, we observe at late times a diffusive broadening of the fronts controlled by an effective shear viscosity that diverges at the critical point. No matter how small the microscopic coefficient of dissipation, strongly disordered networks behave as if they were over-damped because energy is irreversibly leaked into diverging non-affine fluctuations. Close to the transition, the regime of linear response becomes vanishingly small: the tiniest shear strains generate strongly non-linear shear shock waves qualitatively different from their compressional counterparts in granular media. The inherent non-linearities trigger an energy cascade from low to high frequency components that keep the network away from attaining the quasi-static limit. This mechanism, reminiscent of acoustic turbulence, causes a super-diffusive broadening of the shock width.

  12. A variable parameter thermionic energy converter

    E-Print Network [OSTI]

    Bragg, Bobby Joe

    1967-01-01T23:59:59.000Z

    A VARIABLE PARAMETER THERMIONIC ENERGY CONVERTER A Thesis By Bobby Joe Bragg Submitted to the Graduate School of the Texas A 8c M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August, 1967 Major... LIST OF FIGURES FIGURE 1. SIMPLE SCHEMATIC OF A THERMIONIC CONVERTER PAGE 2. POWER VS SPACING WITH A MINIMUM POWER POINT 3. POWER VS SPACING WITH NO MINIMUM POWER POINT 4. CONVERTER MOTIVE DIAGRAM~ O'E = 5. CONVERTER MOTIVE DIAGRAM~ 6. CONVERTER...

  13. Thermionic converter emitter support arrangement

    SciTech Connect (OSTI)

    Allen, D.T.

    1990-10-16T23:59:59.000Z

    A support is presented for use in a thermionic converted to support an end of an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially at its temperatures changes. The emitter end is supported by a spring structure that includes a pair of Belleville springs, and the spring structure is supported by a support structure fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element at the front end, a large metal main support at the rear end that is attached to the housing, and metal main support. The spring structure can include a loose wafer captured between the Belleville springs.

  14. Thermionic converter emitter support arrangement

    SciTech Connect (OSTI)

    Allen, Daniel T. (La Jolla, CA)

    1990-01-01T23:59:59.000Z

    A support is provided for use in a therminonic converter to support an end of an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially as its temperature changes. The emitter end (34) is supported by a spring structure (44) that includes a pair of Belleville springs, and the spring structure is supported by a support structure (42) fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element (74) at the front end, a larger metal main support (76) at the rear end that is attached to the housing, and with a ceramic layer (80) between them that is bonded by hot isostatic pressing to the metal element and metal main support. The spring structure can include a loose wafer (120) captured between the Belleville springs.

  15. Thermionic converter emitter support arrangement

    DOE Patents [OSTI]

    Allen, Daniel T. (La Jolla, CA)

    1990-01-01T23:59:59.000Z

    A support is provided for use in a thermionic converter to support an end an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially at its temperatures changes. The emitter end (34) is supported by a spring structure (44) that includes a pair of Belleville springs, and the spring structure is supported by a support structure (42) fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element (74) at the front end, a larger metal main support (76) at the rear end that is attached to the housng, and with a ceramic layer (80) between them that is bonded by hot isostatic pressing to the metal element and metal main support. The spring structure can include a loose wafer (120) captured between the Belleville springs.

  16. Thermionic converter emitter support arrangement

    SciTech Connect (OSTI)

    Allen, D.T.

    1990-05-22T23:59:59.000Z

    This patent describes a support provided for use in a therminonic converter to support an end of an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially as its temperature changes. The emitter end is supported by a spring structure that includes a pair of Belleville springs, and the spring structure is supported by a support structure fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element at the front end, a larger metal main support at the rear end that is attached to the housing, and with a ceramic layer between them that is bonded by hot isostatic pressing to the metal element and metal main support. The spring structure can include a loose wafer captured between the Belleville springs.

  17. Thermionic converter emitter support arrangement

    SciTech Connect (OSTI)

    Allen, D.T.

    1989-07-06T23:59:59.000Z

    This document discusses a support provided for use in a thermionic converter to support an end of an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially as its temperature changes. The emitter end is supported by a spring structure that includes a pair of Belleville springs, and the spring structure is supported by a support structure fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element at the front end, a larger metal main support at the rear end that is attached to the housing, and with a ceramic layer between them that is bonded by hot isostatic pressing to the metal element and metal main support. The spring structure can include a loose wafer captured between the Belleville springs. 7 figs.

  18. Subcritical dynamos in shear flows

    E-Print Network [OSTI]

    F. Rincon; G. I. Ogilvie; M. R. E. Proctor; C. Cossu

    2008-05-09T23:59:59.000Z

    Identifying generic physical mechanisms responsible for the generation of magnetic fields and turbulence in differentially rotating flows is fundamental to understand the dynamics of astrophysical objects such as accretion disks and stars. In this paper, we discuss the concept of subcritical dynamo action and its hydrodynamic analogue exemplified by the process of nonlinear transition to turbulence in non-rotating wall-bounded shear flows. To illustrate this idea, we describe some recent results on nonlinear hydrodynamic transition to turbulence and nonlinear dynamo action in rotating shear flows pertaining to the problem of turbulent angular momentum transport in accretion disks. We argue that this concept is very generic and should be applicable to many astrophysical problems involving a shear flow and non-axisymmetric instabilities of shear-induced axisymmetric toroidal velocity or magnetic fields, such as Kelvin-Helmholtz, magnetorotational, Tayler or global magnetoshear instabilities. In the light of several recent numerical results, we finally suggest that, similarly to a standard linear instability, subcritical MHD dynamo processes in high-Reynolds number shear flows could act as a large-scale driving mechanism of turbulent flows that would in turn generate an independent small-scale dynamo.

  19. New Catalyst Converts CO2 to Fuel

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

    New Catalyst Converts CO to Fuel Calculations Run at NERSC Help Confirm University of Illinois Breakthrough September 5, 2014 | Tags: Basic Energy Sciences (BES), Carver,...

  20. Vacuum-insulated catalytic converter

    DOE Patents [OSTI]

    Benson, David K. (Golden, CO)

    2001-01-01T23:59:59.000Z

    A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

  1. Stratified Shear Flow: Instability and Wave Radiation

    E-Print Network [OSTI]

    Sutherland, Bruce

    Stratified Shear Flow: Instability and Wave Radiation B. R. Sutherland Dept. Mathematical of internal waves in the atmosphere and ocean, but the evolution of the shear layer itself is significantly

  2. Fuel to Burn: Economics of Converting Forest

    E-Print Network [OSTI]

    Fried, Jeremy S.

    Fuel to Burn: Economics of Converting Forest Thinnings to Energy Using BioMax in Southern Oregon E-scale gasification plants that generate electrical energy from forest health thinnings may have the potential; Christensen, Glenn. 2005. Fuel to burn: Economics of converting forest thinnings to energy using Bio

  3. High performance, close-spaced thermionic converters

    SciTech Connect (OSTI)

    Dick, R.S.; Britt, E.J.; Fitzpatrick, G.O.; McVey, J.B.

    1983-08-01T23:59:59.000Z

    Near ideal performance in a Thermionic Energy Converter (TEC) can be obtained using extremely small (< 10 microns) interelectrode spacings. Previous efforts to build such converters have encountered engineering problems. A new type of converter, called SAVTEC (for Self-Adjusting, Versatile Thermionic Energy Converter) has been developed at Rasor Associates, Inc., as a practical way to achieve small spacings. It has been demonstrated to deliver improved performance over conventional, ignited-mode converters. A series of individual SAVTEC's have been built and tested. Two general configurations were built: in the first a single emitter support lead (0.25 mm wire) passes through a hole in the center of the collector, with the emitter being welded to it. In the second three smaller wires replace the center wire and are welded to the emitter perimeter. These converters have shown reliable, temperature controlled spacings of the emitter and collector. Reproducible spacing of 10 microns (0.4 mils) were achieved on several converters. This paper presents details of SAVTEC converter construction and performance, including volt-ampere curves.

  4. Refraction of shear zones in granular materials

    E-Print Network [OSTI]

    Tamas Unger

    2007-01-08T23:59:59.000Z

    We study strain localization in slow shear flow focusing on layered granular materials. A heretofore unknown effect is presented here. We show that shear zones are refracted at material interfaces in analogy with refraction of light beams in optics. This phenomenon can be obtained as a consequence of a recent variational model of shear zones. The predictions of the model are tested and confirmed by 3D discrete element simulations. We found that shear zones follow Snell's law of light refraction.

  5. Catalytic converter with thermoelectric generator

    SciTech Connect (OSTI)

    Parise, R.J.

    1998-07-01T23:59:59.000Z

    The unique design of an electrically heated catalyst (EHC) and the inclusion of an ECO valve in the exhaust of an internal combustion engine will meet the strict new emission requirements, especially at vehicle cold start, adopted by several states in this country as well as in Europe and Japan. The catalytic converter (CC) has been a most useful tool in pollution abatement for the automobile. But the emission requirements are becoming more stringent and, along with other improvements, the CC must be improved to meet these new standards. Coupled with the ECO valve, the EHC can meet these new emission limits. In an internal combustion engine vehicle (ICEV), approximately 80% of the energy consumed leaves the vehicle as waste heat: out the tail pipe, through the radiator, or convected/radiated off the engine. Included with the waste heat out the tail pipe are the products of combustion which must meet strict emission requirements. The design of a new CC is presented here. This is an automobile CC that has the capability of producing electrical power and reducing the quantity of emissions at vehicle cold start, the Thermoelectric Catalytic Power Generator. The CC utilizes the energy of the exothermic reactions that take place in the catalysis substrate to produce electrical energy with a thermoelectric generator. On vehicle cold start, the thermoelectric generator is used as a heat pump to heat the catalyst substrate to reduce the time to catalyst light-off. Thus an electrically heated catalyst (EHC) will be used to augment the abatement of tail pipe emissions. Included with the EHC in the exhaust stream of the automobile is the ECO valve. This valve restricts the flow of pollutants out the tail pipe of the vehicle for a specified amount of time until the EHC comes up to operating temperature. Then the ECO valve opens and allows the full exhaust, now treated by the EHC, to leave the vehicle.

  6. Plastic deformation of a model glass induced by a local shear transformation

    E-Print Network [OSTI]

    Nikolai V. Priezjev

    2014-08-28T23:59:59.000Z

    The effect of a local shear transformation on plastic deformation of a three-dimensional amorphous solid is studied using molecular dynamics simulations. We consider a spherical inclusion, which is gradually transformed into an ellipsoid of the same volume and then converted back into the sphere. It is shown that at sufficiently large strain amplitudes, the deformation of the material involves localized plastic events that were identified based on the relative displacement of atoms before and after the shear transformation. We found that the density profiles of cage jumps decay away from the inclusion, which correlates well with the radial dependence of the local deformation of the material. At the same strain amplitude, the plastic deformation becomes more pronounced in the cases of weakly damped dynamics or large time scales of the shear transformation.

  7. Controlled shear/tension fixture

    DOE Patents [OSTI]

    Hsueh, Chun-Hway (Knoxville, TN); Liu, Chain-tsuan (Knoxville, TN); George, Easo P. (Knoxville, TN)

    2012-07-24T23:59:59.000Z

    A test fixture for simultaneously testing two material test samples is provided. The fixture provides substantially equal shear and tensile stresses in each test specimens. By gradually applying a load force to the fixture only one of the two specimens fractures. Upon fracture of the one specimen, the fixture and the load train lose contact and the second specimen is preserved in a state of upset just prior to fracture. Particular advantages of the fixture are (1) to control the tensile to shear load on the specimen for understanding the effect of these stresses on the deformation behavior of advanced materials, (2) to control the location of fracture for accessing localized material properties including the variation of the mechanical properties and residual stresses across the thickness of advanced materials, (3) to yield a fractured specimen for strength measurement and an unfractured specimen for examining the microstructure just prior to fracture.

  8. Converting a Motorcycle to Electric Power

    E-Print Network [OSTI]

    Simcoe, Christopher M.

    2009-12-18T23:59:59.000Z

    Research was conducted to determine how simple and practical it would be to convert a standard gasoline powered motorcycle to electric power. The research involved background investigation of useful concepts in electric powered motorcycles...

  9. New Perspectives on Wave Energy Converter Control 

    E-Print Network [OSTI]

    Price, Alexandra A E

    2009-01-01T23:59:59.000Z

    This work examines some of the fundamental problems behind the control of wave energy converters (WECs). Several new perspectives are presented to aid the understanding of the problem and the interpretation of the ...

  10. CX-004284: Categorical Exclusion Determination | Department of...

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

    Exclusion Determination Recovery Act: Conducting a 3-Dimensional Converted Shear Wave Project CX(s) Applied: A9, B3.1, B3.7 Date: 10182010 Location(s): Imperial County,...

  11. Reversible shear thickening at low shear rates of electrorheological fluids under electric fields

    E-Print Network [OSTI]

    Yu Tian; Minliang Zhang; Jile Jiang; Noshir Pesika; Hongbo Zeng; Jacob Israelachvili; Yonggang Meng; Shizhu Wen

    2010-08-24T23:59:59.000Z

    Shear thickening is a phenomenon of significant viscosity increase of colloidal suspensions. While electrorheological (ER) fluids can be turned into a solid-like material by applying an electric field, their shear strength is widely represented by the attractive electrostatic interaction between ER particles. By shearing ER fluids between two concentric cylinders, we show a reversible shear thickening of ER fluids above a low critical shear rate (100 V/mm), which could be characterized by a modified Mason number. Shear thickening and electrostatic particle interaction-induced inter-particle friction forces is considered to be the real origin of the high shear strength of ER fluids, while the applied electric field controls the extent of shear thickening. The electric field-controlled reversible shear thickening has implications for high-performance ER/magnetorheological (MR) fluid design, clutch fluids with high friction forces triggered by applying local electric field, other field-responsive materials and intelligent systems.

  12. Sheared

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBi (2)Sharing Smart Grid Experiences throughand Infrared

  13. MULTILEVEL CONVERTERS - A NEW BREED OF POWER CONVERTERS Jih-Sheng...

    Office of Scientific and Technical Information (OSTI)

    well suited for various renewable energy sources such as fuel cell, photovoltaic, and biomass, etc. Connecting separated dc sources between two converters in a back-to-back...

  14. acid residues converted: Topics by E-print Network

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

    Websites Summary: - Resonant converters and related systems, such as piezoelectric transformers, may require a high of resonant converters: a series-resonant parallel-...

  15. ars projekt converted: Topics by E-print Network

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

    Websites Summary: - Resonant converters and related systems, such as piezoelectric transformers, may require a high of resonant converters: a series-resonant parallel-...

  16. angiotensin converting enzyme-3: Topics by E-print Network

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

    Websites Summary: - Resonant converters and related systems, such as piezoelectric transformers, may require a high of resonant converters: a series-resonant parallel-...

  17. angiotensin converting enzyme: Topics by E-print Network

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

    Websites Summary: - Resonant converters and related systems, such as piezoelectric transformers, may require a high of resonant converters: a series-resonant parallel-...

  18. Atargis Energy (TRL 4 System) - Cycloidal Wave Energy Converter...

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

    Atargis Energy (TRL 4 System) - Cycloidal Wave Energy Converter Atargis Energy (TRL 4 System) - Cycloidal Wave Energy Converter Atargis Energy (TRL 4 System) - Cycloidal Wave...

  19. SEP Success Story: State Energy Program Helping Arkansans Convert...

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

    State Energy Program Helping Arkansans Convert to Compressed Natural Gas SEP Success Story: State Energy Program Helping Arkansans Convert to Compressed Natural Gas January 25,...

  20. Converting Sunlight into Fuel | Center for Bio-Inspired Solar...

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

    about Center Center Video Library Bisfuel Picture Gallery Converting Sunlight into Fuel 12 Oct 2012 Converting sunlight into electricity from ASU Research on Vimeo. Interview...

  1. Enterprise converting buses to biodiesel | Department of Energy

    Energy Savers [EERE]

    Enterprise converting buses to biodiesel Enterprise converting buses to biodiesel April 1, 2010 - 6:48pm Addthis Paul Lester Communications Specialist, Office of Energy Efficiency...

  2. Critical shear stresses in cohesive soils

    E-Print Network [OSTI]

    Rektorik, Robert James

    1964-01-01T23:59:59.000Z

    CRITICAL SHEAR STRESSES IN COHESIVE SOILS A Thesis By ROBERT JAMES REKTORIK Approved as to style and content by: (Committee hairm g- c& ( ead of epartm ( mber) (Member) January 1964 ACKNOWLEDGMENTS I wish to acknowledge the guidance..., and Dummy Soil Sample 17 Typical Soil Samples after Scour Test, San Saba Clay 25 Typical Soil Samples after Scour Test, Houston Black Clay, K177 Regression of Critical Shearing Force on Per Cent Moisture . 31 10. Regression of Critical Shearing Force...

  3. Confined Cubic Blue Phases under Shear

    E-Print Network [OSTI]

    O. Henrich; K. Stratford; D. Marenduzzo; P. V. Coveney; M. E. Cates

    2012-03-14T23:59:59.000Z

    We study the behaviour of confined cubic blue phases under shear flow via lattice Boltzmann simulations. We focus on the two experimentally observed phases, blue phase I and blue phase II. The disinclination network of blue phase II continuously breaks and reforms under shear, leading to an oscillatory stress response in time. The oscillations are only regular for very thin samples. For thicker samples, the shear leads to a "stick-slip" motion of part of the network along the vorticity direction. Blue phase I responds very differently: its defect network undergoes seemingly chaotic rearrangements under shear, irrespective of system size.

  4. Isolated and soft-switched power converter

    DOE Patents [OSTI]

    Peng, Fang Zheng (Knoxville, TN); Adams, Donald Joe (Knoxville, TN)

    2002-01-01T23:59:59.000Z

    An isolated and soft-switched power converter is used for DC/DC and DC/DC/AC power conversion. The power converter includes two resonant tank circuits coupled back-to-back through an isolation transformer. Each resonant tank circuit includes a pair of resonant capacitors connected in series as a resonant leg, a pair of tank capacitors connected in series as a tank leg, and a pair of switching devices with anti-parallel clamping diodes coupled in series as resonant switches and clamping devices for the resonant leg. The power converter is well suited for DC/DC and DC/DC/AC power conversion applications in which high-voltage isolation, DC to DC voltage boost, bidirectional power flow, and a minimal number of conventional switching components are important design objectives. For example, the power converter is especially well suited to electric vehicle applications and load-side electric generation and storage systems, and other applications in which these objectives are important. The power converter may be used for many different applications, including electric vehicles, hybrid combustion/electric vehicles, fuel-cell powered vehicles with low-voltage starting, remote power sources utilizing low-voltage DC power sources, such as photovoltaics and others, electric power backup systems, and load-side electric storage and generation systems.

  5. Vane shear determination of the visco-elastic shear modulus of submarine sediments

    E-Print Network [OSTI]

    Stevenson, Herbert Scott

    1973-01-01T23:59:59.000Z

    the process of deformation under shear can be considered and some of the factors affecting the viscoelastic nature of submarine clays can be identified. When the flocculent clay structure is subjected to shear the bonds between the particles ai e first... of MASTER OF SCIENCE December 1973 Major Subject: Civil Engineering VANE SHEAR DETERMINATION OF THE VISCOELASTIC SHEAR MODULUS OF SUBMARINE SEDIMENTS A Thesis by Herbert Scott Stevenson Approved as to style and content by: Chairman of Committ e M...

  6. External ionization mechanisms for advanced thermionic converters

    SciTech Connect (OSTI)

    Hatziprokopiou, M.E.

    1981-01-01T23:59:59.000Z

    This work investigates ion generation and recombination mechanisms in the cesium plasma as they pertain to the advanced mode thermionic energy converter. The changes in plasma density and temperature within the converter have been studied under the influence of several promising auxiliary ionization candidate sources. Three novel approaches of external cesium ion generation have been investigated in some detail, namely vibrationally excited N/sub 2/ as are energy source of ionization of Cs ions in a dc discharge, microwave power as a means of resonant sustenance of the cesium plasma, and ion generation in a pulse N/sub 2/-Cs mixture. The experimental data obtained and discussed in this work show that all three techniques - i.e. the non-LTE high-voltage pulsing, the energy transfer from vibrationally excited diatomic gases, and the external pumping with a microwave power - have considerable promise as schemes in auxiliary ion generation applicable to the advanced thermionic energy converter.

  7. Internal and Interface Shear Strength of

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    1 Internal and Interface Shear Strength of Geosynthetic Clay Liners (GCLs): Additional Data by John Liners (GCLs): Additional Data Geosynthetic Clay Liners (GCLs) are prefabricated geocomposite materials., Zornberg, Jorge G., and Swan, Jr., Robert H. Internal and Interface Shear Strength of Geosynthetic Clay

  8. 2014 SHEEP SHEARING SCHOOL University of Kentucky

    E-Print Network [OSTI]

    Hayes, Jane E.

    2014 SHEEP SHEARING SCHOOL University of Kentucky March 25 and 26, 2014 Sheep Unit, C. Oran Little Animal Research Center, Versailles, KY Sponsored by the Kentucky Sheep and Wool Producers Association in Cooperation with the University of Kentucky Cooperative Extension Service PURPOSE The shearing school

  9. Three dimensional fabric evolution of sheared sand

    SciTech Connect (OSTI)

    Hasan, Alsidqi; Alshibli, Khalid (UWA)

    2012-10-24T23:59:59.000Z

    Granular particles undergo translation and rolling when they are sheared. This paper presents a three-dimensional (3D) experimental assessment of fabric evolution of sheared sand at the particle level. F-75 Ottawa sand specimen was tested under an axisymmetric triaxial loading condition. It measured 9.5 mm in diameter and 20 mm in height. The quantitative evaluation was conducted by analyzing 3D high-resolution x-ray synchrotron micro-tomography images of the specimen at eight axial strain levels. The analyses included visualization of particle translation and rotation, and quantification of fabric orientation as shearing continued. Representative individual particles were successfully tracked and visualized to assess the mode of interaction between them. This paper discusses fabric evolution and compares the evolution of particles within and outside the shear band as shearing continues. Changes in particle orientation distributions are presented using fabric histograms and fabric tensor.

  10. Converting Waste into Clean Renewable Fuel

    E-Print Network [OSTI]

    Converting Waste into Clean Renewable Fuel Presented at TechRealization August 27th, 2008 #12;2 Outline · Introduction to InEnTec · InEnTec's Waste-to-Fuels Technology · Richland Project #12;In conversion options · Conversion of waste into clean transportation fuels (i.e. ethanol, methanol, DME, etc

  11. Hybrid switch for resonant power converters

    DOE Patents [OSTI]

    Lai, Jih-Sheng; Yu, Wensong

    2014-09-09T23:59:59.000Z

    A hybrid switch comprising two semiconductor switches connected in parallel but having different voltage drop characteristics as a function of current facilitates attainment of zero voltage switching and reduces conduction losses to complement reduction of switching losses achieved through zero voltage switching in power converters such as high-current inverters.

  12. Characteristics of two thermionic converters with oxide collectors

    SciTech Connect (OSTI)

    Smith, E.A.; Huffman, F.N.

    1984-08-01T23:59:59.000Z

    Thermionic converters built with selected metal oxide coatings on their collectors have given enhanced performance at interelectrode spacings greater than 0.25 mm. The capability of such converters to operate efficiently at large interelectrode spacings is of interest for in-core thermionic power systems. Performance data are reported from one converter built with a collector having a coating of molybdenum sublimed in oxygen and a second converter containing an oxidized zirconium collector. The molybdenum oxide collector converter demonstrated enhanced performance.

  13. Combustion converter development for topping and cogeneration applications

    SciTech Connect (OSTI)

    Goodale, D.; Lieb, D.; Miskolczy, G.; Moffat, A.

    1983-08-01T23:59:59.000Z

    This paper discusses the development of combustion-heated thermionic converters. Combustion applications pose a materials problem that does not exist for thermionic converters used in the vacuum of outer space. The high-temperature components of a thermionic converter must be protected from the oxidizing terrestrial environment. A layer of silicon carbide provides the most satisfactory protective coating, or ''hot shell,'' for the emitter and lead of a combustion-heated thermionic converter. Four areas of work aimed at developing combustion heated thermionic converters will be discussed: improving the performance of the two-inch torispherical converter, modifications to the converter so that it may be used in multi-converter modules, the construction of a thermionic cogeneration test furnace, and a converter life test in an oil-fired furnace.

  14. Optical analog-to-digital converter

    DOE Patents [OSTI]

    Vawter, G. Allen (Corrales, NM); Raring, James (Goleta, CA); Skogen, Erik J. (Albuquerque, NM)

    2009-07-21T23:59:59.000Z

    An optical analog-to-digital converter (ADC) is disclosed which converts an input optical analog signal to an output optical digital signal at a sampling rate defined by a sampling optical signal. Each bit of the digital representation is separately determined using an optical waveguide interferometer and an optical thresholding element. The interferometer uses the optical analog signal and the sampling optical signal to generate a sinusoidally-varying output signal using cross-phase-modulation (XPM) or a photocurrent generated from the optical analog signal. The sinusoidally-varying output signal is then digitized by the thresholding element, which includes a saturable absorber or at least one semiconductor optical amplifier, to form the optical digital signal which can be output either in parallel or serially.

  15. Periodic Exponential Shear of Complex Fluids

    E-Print Network [OSTI]

    Chirag Kalelkar; Gareth McKinley

    2012-05-31T23:59:59.000Z

    We define a class of flows with exponential kinematics termed Periodic Exponential Shear (PES) flow which involve periodic exponential stretching of fluid elements along with their rotation. We exhibit analytical and numerical results for PES flow by using the Oldroyd-B model for viscoelastic fluids. We calculate the growth in the shear and the normal stresses analytically as well as demonstrate that repeated application of the flow leads to stable oscillatory shear and normal stresses. We define a material function applicable to a periodic, unsteady shear flow and show numerically that this material function exhibits deformation-rate thickening behavior for viscoelastic fluids subject to PES flow. We demonstrate the feasibility of PES flow by presenting preliminary experimental results from a controlled-strain rate rheometer, using a Newtonian mineral oil.

  16. Joint environmental assessment for western NPR-1 3-dimensional seismic project at Naval Petroleum Reserve No. 1, Kern County, California

    SciTech Connect (OSTI)

    NONE

    1996-05-01T23:59:59.000Z

    The Department of Energy (DOE), in conjunction with the Bureau of Land Management (BLM), has prepared an Environmental Assessment (DOE/EA-1124) to identify and evaluate the potential environmental impacts of the proposed geophysical seismic survey on and adjacent to the Naval Petroleum Reserve No.1 (NPR-1), located approximately 35 miles west of Bakersfield, California. NPR-1 is jointly owned and operated by the federal government and Chevron U.S.A. Production Company. The federal government owns about 78 percent of NPR-1, while Chevron owns the remaining 22 percent. The government`s interest is under the jurisdiction of DOE, which has contracted with Bechtel Petroleum Operations, Inc. (BPOI) for the operation and management of the reserve. The 3-dimensional seismic survey would take place on NPR-1 lands and on public and private lands adjacent to NPR-1. This project would involve lands owned by BLM, California Department of Fish and Game (CDFG), California Energy Commission (CEC), The Nature Conservancy, the Center for Natural Lands Management, oil companies (Chevron, Texaco, and Mobil), and several private individuals. The proposed action is designed to provide seismic data for the analysis of the subsurface geology extant in western NPR-1 with the goal of better defining the commercial limits of a currently producing reservoir (Northwest Stevens) and three prospective hydrocarbon bearing zones: the {open_quotes}A Fan{close_quotes} in Section 7R, the 19R Structure in Section 19R, and the 13Z Structure in Section 13Z. Interpreting the data is expected to provide NPR-1 owners with more accurate locations of structural highs, faults, and pinchouts to maximize the recovery of the available hydrocarbon resources in western NPR-1. Completion of this project is expected to increase NPR-1 recoverable reserves, and reduce the risks and costs associated with further exploration and development in the area.

  17. Chondroregulatory action of prolactin on proliferation and differentiation of mouse chondrogenic ATDC5 cells in 3-dimensional micromass cultures

    SciTech Connect (OSTI)

    Seriwatanachai, Dutmanee [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok (Thailand)] [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok (Thailand); Krishnamra, Nateetip [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok (Thailand) [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok (Thailand); Department of Physiology, Faculty of Science, Mahidol University, Bangkok (Thailand); Charoenphandhu, Narattaphol, E-mail: naratt@narattsys.com [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok (Thailand) [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok (Thailand); Department of Physiology, Faculty of Science, Mahidol University, Bangkok (Thailand)

    2012-03-30T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer Mouse chondrogenic ATDC5 cells expressed PRL receptor mRNAs and proteins. Black-Right-Pointing-Pointer Low PRL concentration (10 ng/mL) increased chondrocyte viability and differentiation. Black-Right-Pointing-Pointer Higher PRL concentrations ( Greater-Than-Or-Slanted-Equal-To 100 ng/mL) decreased viability and increased apoptosis. -- Abstract: A recent investigation in lactating rats has provided evidence that the lactogenic hormone prolactin (PRL) increases endochondral bone growth and bone elongation, presumably by accelerating apoptosis of hypertrophic chondrocytes in the growth plate and/or subsequent chondrogenic matrix mineralization. Herein, we demonstrated the direct chondroregulatory action of PRL on proliferation, differentiation and apoptosis of chondrocytes in 3-dimensional micromass culture of mouse chondrogenic ATDC5 cell line. The results showed that ATDC5 cells expressed PRL receptor (PRLR) transcripts, and responded typically to PRL by downregulating PRLR expression. Exposure to a low PRL concentration of 10 ng/mL, comparable to the normal levels in male and non-pregnant female rats, increased chondrocyte viability, differentiation, proteoglycan accumulation, and mRNA expression of several chondrogenic differentiation markers, such as Sox9, ALP and Hspg2. In contrast, high PRL concentrations of Greater-Than-Or-Slanted-Equal-To 100 ng/mL, comparable to the levels in pregnancy or lactation, decreased chondrocyte viability by inducing apoptosis, with no effect on chondrogenic marker expression. It could be concluded that chondrocytes directly but differentially responded to non-pregnant and pregnant/lactating levels of PRL, thus suggesting the stimulatory effect of PRL on chondrogenesis in young growing individuals, and supporting the hypothesis of hypertrophic chondrocyte apoptosis in the growth plate of lactating rats.

  18. Shear banding in soft glassy materials

    E-Print Network [OSTI]

    Suzanne M. Fielding

    2014-08-20T23:59:59.000Z

    Many soft materials, including foams, dense emulsions, micro gel bead suspensions, star polymers, dense packing of surfactant onion micelles, and textured morphologies of liquid crystals, share the basic "glassy" features of structural disorder and metastability. These in turn give rise to several notable features in the low frequency shear rheology (deformation and flow properties) of these materials: in particular, the existence of a yield stress below which the material behaves like a solid, and above which it flows like a liquid. In the last decade, intense experimental activity has also revealed that these materials often display a phenomenon known as shear banding, in which the flow profile across the shear cell exhibits macroscopic bands of different viscosity. Two distinct classes of yield stress fluid have been identified: those in which the shear bands apparently persist permanently (for as long as the flow remains applied), and those in which banding arises only transiently during a process in which a steady flowing state is established out of an initial rest state (for example, in a shear startup or step stress experiment). After surveying the motivating experimental data, we describe recent progress in addressing it theoretically, using the soft glassy rheology model and a simple fluidity model. We also briefly place these theoretical approaches in the context of others in the literature, including elasto-plastic models, shear transformation zone theories, and molecular dynamics simulations. We discuss finally some challenges that remain open to theory and experiment alike.

  19. Statistics of polymer adsorption under shear flow

    E-Print Network [OSTI]

    Gui-Li He; René Messina; Hartmut Löwen

    2009-10-09T23:59:59.000Z

    Using non-equilibrium Brownian dynamics computer simulations, we have investigated the steady state statistics of a polymer chain under three different shear environments: i) linear shear flow in the bulk (no walls), ii) shear vorticity normal to the adsorbing wall, iii) shear gradient normal to the adsorbing wall. The statistical distribution of the chain end-to-end distance and its orientational angles are calculated within our monomer-resolved computer simulations. Over a wide range of shear rates, this distribution can be mapped onto a simple theoretical finite-extensible-nonlinear-elastic dumbbell model with fitted anisotropic effective spring constants. The tails of the angular distribution functions are consistent with scaling predictions borrowed from the bulk dumbbell model. Finally, the frequency of the characteristic periodic tumbling motion has been investigated by simulation as well and was found to be sublinear with the shear rate for the three set-ups, which extends earlier results done in experiments and simulations for free and tethered polymer molecules without adsorption.

  20. Heat Pump Water Heater using Solid-State Energy Converters |...

    Energy Savers [EERE]

    Heat Pump Water Heater using Solid-State Energy Converters Heat Pump Water Heater using Solid-State Energy Converters Sheetak will work on developing a full scale prototype of its...

  1. A low-power reconfigurable analog-to-digital converter

    E-Print Network [OSTI]

    Gulati, Kush

    2001-01-01T23:59:59.000Z

    This thesis presents the concept, theory and design of a low power CMOS analog-to-digital converter that can digitize signals over a wide range of bandwidth and resolution with adaptive power consumption. The converter ...

  2. Automated Synthesis Tool for Design Optimization of Power Electronic Converters

    E-Print Network [OSTI]

    Mirjafari, Mehran

    2013-01-09T23:59:59.000Z

    module-integrated photovoltaic inverter is also optimized for efficiency, volume and reliability. An actual converter is constructed using commercial off-the-shelf components. The converter design is chosen as close as possible to a point obtained...

  3. An economical single to three phase converter for induction motors

    E-Print Network [OSTI]

    Di Zerega, Philp Van Uytandaele

    1994-01-01T23:59:59.000Z

    There are several different types of single to three phase converters for induction motors available today. However, many of the presently available phase converters suffer from disadvantages such as high cost or low performance. An economical...

  4. Weekly Wrap-Up: Testing Wind Blades, Converting Carbon Emissions...

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

    Weekly Wrap-Up: Testing Wind Blades, Converting Carbon Emissions, and Eco-Driving Weekly Wrap-Up: Testing Wind Blades, Converting Carbon Emissions, and Eco-Driving July 23, 2010 -...

  5. LM2907LM2917FrequencytoVoltageConverter February 1995

    E-Print Network [OSTI]

    Wedeward, Kevin

    TL H 7942 LM2907LM2917FrequencytoVoltageConverter February 1995 LM2907 LM2917 Frequency to Voltage Converter General Description The LM2907 LM2917 series are monolithic frequency to voltage converters doubling for low ripple full input protection in two versions (LM2907-8 LM2917-8) and its output swings

  6. A transient model for a cesium vapor thermionic converter. [Cs

    SciTech Connect (OSTI)

    El-Genk, M.S.; Murray, C.S.; Chaudhuri, S. (Institute for Space Nuclear Power Studies, Department of Chemical and Nuclear Engineering, The University of New Mexico, Albuquerque, New Mexico (USA))

    1991-01-10T23:59:59.000Z

    This paper presents an analytical model for simulating the transient and steady-state operation of cesium vapor thermionic converters. A parametric analysis is performed to assess the transient response of the converter to changes in fission power and width of interelectrode gap. The model optimizes the converter performance for maximum electric power to the load.(AIP)

  7. Voltage balanced multilevel voltage source converter system

    DOE Patents [OSTI]

    Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)

    1997-01-01T23:59:59.000Z

    A voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means.

  8. Voltage balanced multilevel voltage source converter system

    DOE Patents [OSTI]

    Peng, F.Z.; Lai, J.S.

    1997-07-01T23:59:59.000Z

    Disclosed is a voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means. 15 figs.

  9. Photovoltaic converter having apertured reflective enclosure

    SciTech Connect (OSTI)

    Sinton, R.A.; Swanson, R.M.

    1990-10-02T23:59:59.000Z

    This patent describes a photovoltaic converter. It comprises: a photovoltaic cell having an incident face upon which light is directed to cause photogeneration; an enclosure over the incident face, the wall of the enclosure having a reflective inner surface spaced apart from the incident face to permit light reflected from the incident face to be re-reflected by the inner surface and back to the photovoltaic cell; and an aperture through the wall of the enclosure to permit light to fall directly upon the voltaic cell. The ratio of the area of the aperture to the are of the incident face of the photovoltaic cell is less than about 0.2.

  10. convert program | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartmentNational NuclearhasAdministration goSecuritycdns | Nationalcontracting |convert

  11. Relationship Among Efficiency and Output Power of Heat Energy Converters

    E-Print Network [OSTI]

    Alexander Luchinskiy

    2004-09-02T23:59:59.000Z

    Relationship among efficiency and output power of heat-electric energy converters as well as of any converters for transforming of heat energy into any other kind of energy is considered. It is shown, that the parameter efficiency does not determine univocally the output power of a converter. It is proposed to use another parameter for determination of working ability of heat energy converters. It is shown, that high output power can not be achieved by any kind of Stirling-type converters in spite of their high efficiency.

  12. Converting online algorithms to local computation algorithms

    E-Print Network [OSTI]

    Mansour, Yishay; Vardi, Shai; Xie, Ning

    2012-01-01T23:59:59.000Z

    We propose a general method for converting online algorithms to local computation algorithms by selecting a random permutation of the input, and simulating running the online algorithm. We bound the number of steps of the algorithm using a query tree, which models the dependencies between queries. We improve previous analyses of query trees on graphs of bounded degree, and extend the analysis to the cases where the degrees are distributed binomially, and to a special case of bipartite graphs. Using this method, we give a local computation algorithm for maximal matching in graphs of bounded degree, which runs in time and space O(log^3 n). We also show how to convert a large family of load balancing algorithms (related to balls and bins problems) to local computation algorithms. This gives several local load balancing algorithms which achieve the same approximation ratios as the online algorithms, but run in O(log n) time and space. Finally, we modify existing local computation algorithms for hypergraph 2-color...

  13. Integrated Solar Upper Stage (ISUS) thermionic converter string evaluation

    SciTech Connect (OSTI)

    Talbot, G.J.; Ramsey, W.D.; Chao, C.J.

    1998-07-01T23:59:59.000Z

    A serial string of eighth (8) thermionic converters were performance tested at New Mexico Engineering Research Institute (NMERI) by Frank Wyant et al1. The tests results from the second String Thermionic Assembly Research Testbed (START II) produced less than one half the expected power based on individual converter performance tests. Seven of the eight converters were returned to Lockheed Martin Information Systems-EOS for performance evaluation. Six of the seven produced nominal performance while the seventh converter showed a drastic reduction in performance due to a cesium leak to atmosphere. Several models were proposed to explain why the individual converter performance differed so markedly from the START II serial array. This paper discusses the models, evaluates model validity and compares the models with results from a tow converter serial test using of the returned START II converters.

  14. Pressure-shear experiments on granular materials.

    SciTech Connect (OSTI)

    Reinhart, William Dodd (Sandia National Laboratories, Albuquerque, NM); Thornhill, Tom Finley, III (, Sandia National Laboratories, Albuquerque, NM); Vogler, Tracy John; Alexander, C. Scott (Sandia National Laboratories, Albuquerque, NM)

    2011-10-01T23:59:59.000Z

    Pressure-shear experiments were performed on granular tungsten carbide and sand using a newly-refurbished slotted barrel gun. The sample is a thin layer of the granular material sandwiched between driver and anvil plates that remain elastic. Because of the obliquity, impact generates both a longitudinal wave, which compresses the sample, and a shear wave that probes the strength of the sample. Laser velocity interferometry is employed to measure the velocity history of the free surface of the anvil. Since the driver and anvil remain elastic, analysis of the results is, in principal, straightforward. Experiments were performed at pressures up to nearly 2 GPa using titanium plates and at higher pressure using zirconium plates. Those done with the titanium plates produced values of shear stress of 0.1-0.2 GPa, with the value increasing with pressure. On the other hand, those experiments conducted with zirconia anvils display results that may be related to slipping at an interface and shear stresses mostly at 0.1 GPa or less. Recovered samples display much greater particle fracture than is observed in planar loading, suggesting that shearing is a very effective mechanism for comminution of the grains.

  15. Power Maximization in Wave-Energy Converters Using Sampled -Data Extremum Seeking /

    E-Print Network [OSTI]

    Chen, Tianjia

    2013-01-01T23:59:59.000Z

    Power Maximization in Wave-Energy Converters Using Sampled-design optimization of wave energy converters con- sistingN. Sahinkaya. A review of wave energy converter technology.

  16. E-Print Network 3.0 - advanced power converters Sample Search...

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

    (PO.139) Track: Technical Summary: turbines with partial scale power converter and (ii) wind turbines with full scale power converter... power converter of the DFIG can be...

  17. Shear induced rigidity in athermal materials: a unified statistical framework

    E-Print Network [OSTI]

    Sumantra Sarkar; Bulbul Chakraborty

    2015-02-18T23:59:59.000Z

    Recent studies of athermal systems such as dry grains and dense, non-Brownian suspensions have shown that shear can lead to solidification through the process of shear jamming in grains and discontinuous shear thickening in suspensions. The similarities observed between these two distinct phenomena suggest that the physical processes leading to shear-induced rigidity in athermal materials are universal. We present a non-equilibrium statistical mechanics model, which exhibits the phenomenology of these shear-driven transitions: shear jamming and discontinuous shear thickening in different regions of the predicted phase diagram. Our analysis identifies the crucial physical processes underlying shear-driven rigidity transitions, and clarifies the distinct roles played by shearing forces and the density of grains.

  18. Shear Viscosity of a Hot Pion Gas

    E-Print Network [OSTI]

    Robert Lang; Norbert Kaiser; Wolfram Weise

    2012-09-04T23:59:59.000Z

    The shear viscosity of an interacting pion gas is studied using the Kubo formalism as a microscopic description of thermal systems close to global equilibrium. We implement the skeleton expansion in order to approximate the retarded correlator of the viscous part of the energy-momentum tensor. After exploring this in $g\\phi^4$ theory we show how the skeleton expansion can be consistently applied to pions in chiral perturbation theory. The shear viscosity $\\eta$ is determined by the spectral width, or equivalently, the mean free path of pions in the heat bath. We derive a new analytical result for the mean free path which is well-conditioned for numerical evaluation and discuss the temperature and pion-mass dependence of the mean free path and the shear viscosity. The ratio $\\eta/s$ of the interacting pion gas exceeds the lower bound $1/4\\pi$ from AdS/CFT correspondence.

  19. Abstract- CONVERTING SOUND ENERGY TO ELECTRIC ENERGY

    E-Print Network [OSTI]

    Shalabh Rakesh Bhatnagar (srb

    We all know everywhere there is huge scarcity of energy and for running most of our appliances and to carry out daily work we need electricity. It’s really very difficult to imagine our life without electricity, our life would really stop so there is high need, to produce electricity at faster rate and find some other feasible method to produce electric energy. On the other hand we see that in this modern world there is lot of noise pollution in roads, airports, industries.... Just think if we would be able to convert this NOISE POLLUTION TO ELECTRIC ENERGY....??? Yes this could be made possible let’s see how Scientific explanation:- sound is a mechanical form of energy which travel in the form of wave, mechanical wave that is an oscillation of pressure this pressure created by the

  20. Modular Power Converters for PV Applications

    SciTech Connect (OSTI)

    Ozpineci, Burak [ORNL; Tolbert, Leon M [ORNL

    2012-05-01T23:59:59.000Z

    This report describes technical opportunities to serve as parts of a technological roadmap for Shoals Technologies Group in power electronics for PV applications. There are many different power converter circuits that can be used for solar inverter applications. The present applications do not take advantage of the potential for using common modules. We envision that the development of a power electronics module could enable higher reliability by being durable and flexible. Modules would have fault current limiting features and detection circuits such that they can limit the current through the module from external faults and can identify and isolate internal faults such that the remaining modules can continue to operate with only minimal disturbance to the utility or customer. Development of a reliable, efficient, low-cost, power electronics module will be a key enabling technology for harnessing more power from solar panels and enable plug and play operation. Power electronics for computer power supplies, communication equipment, and transportation have all targeted reliability and modularity as key requirements and have begun concerted efforts to replace monolithic components with collections of common smart modules. This is happening on several levels including (1) device level with intelligent control, (2) functional module level, and (3) system module. This same effort is needed in power electronics for solar applications. Development of modular units will result in standard power electronic converters that will have a lower installed and operating cost for the overall system. These units will lead to increased adaptability and flexibility of solar inverters. Incorporating autonomous fault current limiting and reconfiguration capabilities into the modules and having redundant modules will lead to a durable converter that can withstand the rigors of solar power generation for more than 30 years. Our vision for the technology roadmap is that there is no need for detailed design of new power converters for each new application or installation. One set of modules and controllers can be pre-developed and the only design question would be how many modules need to be in series or parallel for the specific power requirement. Then, a designer can put the modules together and add the intelligent reconfigurable controller. The controller determines how many modules are connected, but it might also ask for user input for the specific application during setup. The modules include protection against faults and can reset it, if necessary. In case of a power device failure, the controller reconfigures itself to continue limited operation until repair which might be as simple as taking the faulty module out and inserting a new module. The result is cost savings in design, maintenance, repair, and a grid that is more reliable and available. This concept would be a perfect fit for the recently announced funding opportunity announcement (DE-FOA-0000653) on Plug and Play Photovoltaics.

  1. Mechanical vibration to electrical energy converter

    DOE Patents [OSTI]

    Kellogg, Rick Allen (Tijeras, NM); Brotz, Jay Kristoffer (Albuquerque, NM)

    2009-03-03T23:59:59.000Z

    Electromechanical devices that generate an electrical signal in response to an external source of mechanical vibrations can operate as a sensor of vibrations and as an energy harvester for converting mechanical vibration to electrical energy. The devices incorporate a magnet that is movable through a gap in a ferromagnetic circuit, wherein a coil is wound around a portion of the ferromagnetic circuit. A flexible coupling is used to attach the magnet to a frame for providing alignment of the magnet as it moves or oscillates through the gap in the ferromagnetic circuit. The motion of the magnet can be constrained to occur within a substantially linear range of magnetostatic force that develops due to the motion of the magnet. The devices can have ferromagnetic circuits with multiple arms, an array of magnets having alternating polarity and, encompass micro-electromechanical (MEM) devices.

  2. Graphene optical-to-thermal converter

    E-Print Network [OSTI]

    Manjavacas, Alejandro; Greffet, Jean-Jacques; de Abajo, F Javier García

    2014-01-01T23:59:59.000Z

    Infrared plasmons in doped graphene nanostructures produce large optical absorption that can be used for narrow-band thermal light emission at tunable frequencies that strongly depend on the doping charge. By virtue of Kirchhoff's law, thermal light emission is proportional to the absorption, thus resulting in narrow emission lines associated with the electrically controlled plasmons of heated graphene. Here we show that realistic designs of graphene plasmonic structures can release over 90% of the emission through individual infrared lines with 1% bandwidth. We examine anisotropic graphene structures in which efficient heating can be produced upon optical pumping tuned to a plasmonic absorption resonance situated in the blue region relative to the thermal emission. An incoherent thermal light converter is thus achieved. Our results open a radically different approach for designing tunable nanoscale infrared light sources.

  3. Internal and Interface Shear Strength of

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    i Internal and Interface Shear Strength of Geosynthetic Clay Liners (GCLs) by John Scott Mc Strength of Geosynthetic Clay Liners (GCLs) Geosynthetic Clay Liners (GCLs) are prefabricated geocomposite materials used as an alternative to compacted clay liners in hydraulic barriers. They often offer hydraulic

  4. Design of series-parallel connected thermionic converter arrays

    SciTech Connect (OSTI)

    Mcvey, J.B.; Britt, E.J.; Fitzpatrick, G.O.; Dick, R.S.

    1981-01-01T23:59:59.000Z

    Applications of thermionic converters require that a large number of converters be connected together in a series-parallel array in order to provide a useful output voltage. Such an array also serves to insure a very high overall system reliability, despite possible failures of individual converters. This paper predicts the effects of a nonuniform distribution of input power on the performance of such an array. 9 refs.

  5. Integrated Solar Power Converters: Wafer-Level Sub-Module Integrated DC/DC Converter

    SciTech Connect (OSTI)

    None

    2012-02-09T23:59:59.000Z

    Solar ADEPT Project: CU-Boulder is developing advanced power conversion components that can be integrated into individual solar panels to improve energy yields. The solar energy that is absorbed and collected by a solar panel is converted into useable energy for the grid through an electronic component called an inverter. Many large, conventional solar energy systems use one, central inverter to convert energy. CU-Boulder is integrating smaller, microinverters into individual solar panels to improve the efficiency of energy collection. The University’s microinverters rely on electrical components that direct energy at high speeds and ensure that minimal energy is lost during the conversion process—improving the overall efficiency of the power conversion process. CU-Boulder is designing its power conversion devices for use on any type of solar panel.

  6. Variational bounds for the shear viscosity of gelling melts

    E-Print Network [OSTI]

    Claas H. Köhler; Henning Löwe; Peter Müller; Annette Zippelius

    2007-05-03T23:59:59.000Z

    We study shear stress relaxation for a gelling melt of randomly crosslinked, interacting monomers. We derive a lower bound for the static shear viscosity $\\eta$, which implies that it diverges algebraically with a critical exponent $k\\ge 2\

  7. Shear and Extensional Rheology of Cellulose/Ionic Liquid Solutions

    E-Print Network [OSTI]

    Haward, Simon J.

    In this study, we characterize the shear and extensional rheology of dilute to semidilute solutions of cellulose in the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIAc). In steady shear flow, the semidilute solutions ...

  8. Turbulent Transport in Tokamak Plasmas with Rotational Shear

    SciTech Connect (OSTI)

    Barnes, M.; Highcock, E. G. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP (United Kingdom); Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Parra, F. I.; Schekochihin, A. A. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP (United Kingdom); Cowley, S. C.; Roach, C. M. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2011-04-29T23:59:59.000Z

    Nonlinear gyrokinetic simulations are conducted to investigate turbulent transport in tokamak plasmas with rotational shear. At sufficiently large flow shears, linear instabilities are suppressed, but transiently growing modes drive subcritical turbulence whose amplitude increases with flow shear. This leads to a local minimum in the heat flux, indicating an optimal ExB shear value for plasma confinement. Local maxima in the momentum fluxes are observed, implying the possibility of bifurcations in the ExB shear. The critical temperature gradient for the onset of turbulence increases with flow shear at low flow shears; at higher flow shears, the dependence of heat flux on temperature gradient becomes less stiff. The turbulent Prandtl number is found to be largely independent of temperature and flow gradients, with a value close to unity.

  9. Potential “ways of thinking” about the shear-banding phenomenon

    E-Print Network [OSTI]

    Fardin, M. A.

    Shear-banding is a curious but ubiquitous phenomenon occurring in soft matter. The phenomenological similarities between the shear-banding transition and phase transitions has pushed some researchers to adopt a ‘thermodynamical’ ...

  10. Phenomenology and physical origin of shear-localization and shear-banding in complex fluids

    E-Print Network [OSTI]

    Guillaume Ovarlez; Stéphane Rodts; Xavier Chateau; Philippe Coussot

    2010-02-09T23:59:59.000Z

    We review and compare the phenomenological aspects and physical origin of shear-localization and shear-banding in various material types, namely emulsions, suspensions, colloids, granular materials and micellar systems. It appears that shear-banding, which must be distinguished from the simple effect of coexisting static-flowing regions in yield stress fluids, occurs in the form of a progressive evolution of the local viscosity towards two significantly different values in two adjoining regions of the fluids in which the stress takes slightly different values. This suggests that from a global point of view shear-banding in these systems has a common physical origin: two physical phenomena (for example, in colloids, destructuration due to flow and restructuration due to aging) are in competition and, depending on the flow conditions, one of them becomes dominant and makes the system evolve in a specific direction.

  11. Rheo-PIV of a shear-banding wormlike micellar solution under large amplitude oscillatory shear

    E-Print Network [OSTI]

    Dimitriou, Christopher J.

    We explore the behavior of a wormlike micellar solution under both steady and large amplitude oscillatory shear (LAOS) in a cone–plate geometry through simultaneous bulk rheometry and localized velocimetric measurements. ...

  12. active npc converter: Topics by E-print Network

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

    Solid State Transformer Engineering Websites Summary: converters as distribution transformers 1. A power electronics-based solid state transformer (SST) providesAc-Ac Dual...

  13. alcohol angiotensin-converting-enzyme inhibitors: Topics by E...

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

    complications. There is no specific treatment for membranous nephropathy. Supportive care with the use of diuretics and angiotensin-converting enzyme inhibitors in combination...

  14. Researchers hope better catalysts lead to better ways of converting...

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

    Researchers hope better catalysts lead to better ways of converting biomass to fuel By Jared Sagoff * August 7, 2013 Tweet EmailPrint ARGONNE, Ill. - Scientists and entrepreneurs...

  15. Spurious Shear in Weak Lensing with LSST

    SciTech Connect (OSTI)

    Chang, C.; Kahn, S.M.; Jernigan, J.G.; Peterson, J.R.; AlSayyad, Y.; Ahmad, Z.; Bankert, J.; Bard, D.; Connolly, A.; Gibson, R.R.; Gilmore, K.; Grace, E.; Hannel, M.; Hodge, M.A.; Jee, M.J.; Jones, L.; Krughoff, S.; Lorenz, S.; Marshall, P.J.; Marshall, S.; Meert, A.

    2012-09-19T23:59:59.000Z

    The complete 10-year survey from the Large Synoptic Survey Telescope (LSST) will image {approx} 20,000 square degrees of sky in six filter bands every few nights, bringing the final survey depth to r {approx} 27.5, with over 4 billion well measured galaxies. To take full advantage of this unprecedented statistical power, the systematic errors associated with weak lensing measurements need to be controlled to a level similar to the statistical errors. This work is the first attempt to quantitatively estimate the absolute level and statistical properties of the systematic errors on weak lensing shear measurements due to the most important physical effects in the LSST system via high fidelity ray-tracing simulations. We identify and isolate the different sources of algorithm-independent, additive systematic errors on shear measurements for LSST and predict their impact on the final cosmic shear measurements using conventional weak lensing analysis techniques. We find that the main source of the errors comes from an inability to adequately characterise the atmospheric point spread function (PSF) due to its high frequency spatial variation on angular scales smaller than {approx} 10{prime} in the single short exposures, which propagates into a spurious shear correlation function at the 10{sup -4}-10{sup -3} level on these scales. With the large multi-epoch dataset that will be acquired by LSST, the stochastic errors average out, bringing the final spurious shear correlation function to a level very close to the statistical errors. Our results imply that the cosmological constraints from LSST will not be severely limited by these algorithm-independent, additive systematic effects.

  16. Turbulent transport across shear layers in magnetically confined plasmas

    SciTech Connect (OSTI)

    Nold, B.; Ramisch, M. [Institut für Grenzflächenverfahrenstechnik und Plasmatechnologie, Universität Stuttgart, D-70569 Stuttgart (Germany); Manz, P.; Birkenmeier, G. [Physik-Department E28, Technische Universität München, James-Franck-Str.1, D-85748 Garching (Germany); Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Ribeiro, T. T.; Müller, H. W.; Scott, B. D. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Fuchert, G. [IJL, Université de Lorraine, CNRS (UMR 7198), BP 40239 Vandoeuvre-lès-Nancy (France); Stroth, U. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Physik-Department E28, Technische Universität München, James-Franck-Str.1, D-85748 Garching (Germany)

    2014-10-15T23:59:59.000Z

    Shear layers modify the turbulence in diverse ways and do not only suppress it. A spatial-temporal investigation of gyrofluid simulations in comparison with experiments allows to identify further details of the transport process across shear layers. Blobs in and outside a shear layer merge, thereby exchange particles and heat and subsequently break up. Via this mechanism particles and heat are transported radially across shear layers. Turbulence spreading is the immanent mechanism behind this process.

  17. Band crossing in a shears band of {sup 108}Cd

    SciTech Connect (OSTI)

    Roy, Santosh; Datta, Pradip; Pal, S.; Chattopadhyay, S.; Bhattacharya, S.; Goswami, A.; Jain, H. C.; Joshi, P. K.; Bhowmik, R. K.; Kumar, R.; Muralithar, S.; Singh, R. P.; Madhavan, N.; Rao, P. V. Madhusudhana [S. N. Bose National Centre for Basic Sciences. Block JD, Sector III, Saltlake City, Kolkata 700098 (India); iThemba Labs, Post Office Box 722, Somerset West 7129 (South Africa); Saha Institute of Nuclear Physics, 1/AF Bidhannager Kolkata, 700 064 (India); Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Department of Physics, Andra University, Visakhapatnam 530 003 (India)

    2010-05-15T23:59:59.000Z

    The level lifetimes have been measured for a shears band of {sup 108}Cd that exhibits band crossing. The observed level energies and B(M1) rates have been successfully described by a semiclassical geometric model based on shear mechanism. In this geometric model, the band crossing in the shears band has been described as the reopening of the angle between the blades of a shear.

  18. Elastic capsules in shear flow: Analytical solutions for constant and time-dependent shear rates

    E-Print Network [OSTI]

    Steffen Kessler; Reimar Finken; Udo Seifert

    2009-02-26T23:59:59.000Z

    We investigate the dynamics of microcapsules in linear shear flow within a reduced model with two degrees of freedom. In previous work for steady shear flow, the dynamic phases of this model, i.e. swinging, tumbling and intermittent behaviour, have been identified using numerical methods. In this paper, we integrate the equations of motion in the quasi-spherical limit analytically for time-constant and time-dependent shear flow using matched asymptotic expansions. Using this method, we find analytical expressions for the mean tumbling rate in general time-dependent shear flow. The capsule dynamics is studied in more detail when the inverse shear rate is harmonically modulated around a constant mean value for which a dynamic phase diagram is constructed. By a judicious choice of both modulation frequency and phase, tumbling motion can be induced even if the mean shear rate corresponds to the swinging regime. We derive expressions for the amplitude and width of the resonance peaks as a function of the modulation frequency.

  19. TURBULENT SHEAR STRESS IN HETEROGENEOUS SEDIMENT-LADEN FLOWS

    E-Print Network [OSTI]

    Julien, Pierre Y.

    TURBULENT SHEAR STRESS IN HETEROGENEOUS SEDIMENT-LADEN FLOWS By Hyoseop Woo,1 Associate Member are the beginning of motion of sediment particles and sediment transport in alluvial channels. If shear stress can be well defined in clear-water flows, compar- atively little is known about shear stresses in sediment

  20. Reflective cracking of shear keys in multi-beam bridges

    E-Print Network [OSTI]

    Sharpe, Graeme Peter

    2009-06-02T23:59:59.000Z

    ..............................................2 Figure 2: PCI 33? Box Girder with Shear Keys................................................................5 Figure 3: TxDOT 34? Box Girder with Shear Keys .........................................................5 Figure 4: Test Specimen... Under Tension.........................................................................12 Figure 5: Test Specimen in Bending ...............................................................................12 Figure 6: Test Specimen in Shear...

  1. Effect of Shear Displacement Rate on the Internal Shear Strength of GCLs J. S. McCartney1

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    shear strength of geosynthetic clay liners (GCLs) is to replicate behavior noted in the field. However a wider range of shear displacement rates. Introduction The internal shear strength of geosynthetic clay are prefabricated geocomposite materials used in hydraulic barriers as an alternative to compacted clay liners

  2. Ability of Catalytic Converters to Reduce Air Pollution

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    NOx - 1 Ability of Catalytic Converters to Reduce Air Pollution MEASUREMENT OF SELECTED AIR POLLUTANTS IN CAR EXHAUST Last updated: June 17, 2014 #12;NOx - 2 Ability of Catalytic Converters to Reduce Air Pollution MEASUREMENT OF SELECTED AIR POLLUTANTS IN CAR EXHAUST INTRODUCTION Automobile engines

  3. Way to reduce arc voltage losses in hybrid thermionic converters

    SciTech Connect (OSTI)

    Tskhakaya, V.K.; Yarygin, V.I.

    1982-03-01T23:59:59.000Z

    Experimental results are reported concerning the output and emission characteristics of the arc and hybrid regimes in a plane-parallel thermionic converter with Pt--Zr--O electrode pair. It is shown that arc voltage losses can be reduced to values below those obtainable in ordinary arc thermionic converters.

  4. The frequency dependent impedance of an HVdc converter

    SciTech Connect (OSTI)

    Wood, A.R.; Arrillaga, J. [Univ. of Canterbury, Christchurch (New Zealand)] [Univ. of Canterbury, Christchurch (New Zealand)

    1995-07-01T23:59:59.000Z

    A linear and direct method of determining the frequency dependent impedance of a 12 pulse HVdc converter is presented. Terms are developed for both the dc and ac side impedances of the converter, including the effect of the firing angle control system, the commutation period, and the variability of the commutation period. The impedance predictions are verified by dynamic simulation.

  5. MATHEMATICAL ANALYSIS OF A WAVE ENERGY CONVERTER ARNAUD ROUGIREL

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    for buoy-type ocean wave energy converter. The simplest model for this scheme is a non autonomous piecewise impact on the environment. In this respect, ocean waves provides a important source of renewable energy. Me- chanical devices that harvest energy stored in ocean waves are called wave energy converter (WEC

  6. A computer program for HVDC converter station RF noise calculations

    SciTech Connect (OSTI)

    Kasten, D.G.; Caldecott, R.; Sebo, S.A. (Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering); Liu, Y. (Virginia Polytechnic Inst. State Univ., Blacksburg, VA (United States). Bradley Dept. of Electrical Engineering)

    1994-04-01T23:59:59.000Z

    HVDC converter station operations generate radio frequency (RF) electromagnetic (EM) noise which could interfere with adjacent communication and computer equipment, and carrier system operations. A generic Radio Frequency Computer Analysis Program (RAFCAP) for calculating the EM noise generated by valve ignition of a converter station has been developed as part of a larger project. The program calculates RF voltages, currents, complex power, ground level electric field strength and magnetic flux density in and around an HVDC converter station. The program requires the converter station network to be represented by frequency dependent impedance functions. Comparisons of calculated and measured values are given for an actual HVDC station to illustrate the validity of the program. RAFCAP is designed to be used by engineers for the purpose of calculating the RF noise produced by the igniting of HVDC converter valves.

  7. Direct measurement of shear properties of microfibers

    SciTech Connect (OSTI)

    Behlow, H.; Saini, D.; Durham, L.; Simpson, J.; Skove, M. J.; Rao, A. M. [Department of Physics and Astronomy, and Clemson Nanomaterials Center, Clemson University, Clemson, South Carolina 29634 (United States); Oliveira, L. [School of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634 (United States); Serkiz, S. M. [Department of Physics and Astronomy, and Clemson Nanomaterials Center, Clemson University, Clemson, South Carolina 29634 (United States); Savannah River National Laboratory, Aiken, South Carolina 29808 (United States)

    2014-09-15T23:59:59.000Z

    As novel fibers with enhanced mechanical properties continue to be synthesized and developed, the ability to easily and accurately characterize these materials becomes increasingly important. Here we present a design for an inexpensive tabletop instrument to measure shear modulus (G) and other longitudinal shear properties of a micrometer-sized monofilament fiber sample, such as nonlinearities and hysteresis. This automated system applies twist to the sample and measures the resulting torque using a sensitive optical detector that tracks a torsion reference. The accuracy of the instrument was verified by measuring G for high purity copper and tungsten fibers, for which G is well known. Two industrially important fibers, IM7 carbon fiber and Kevlar{sup ®} 119, were also characterized with this system and were found to have G = 16.5 ± 2.1 and 2.42 ± 0.32 GPa, respectively.

  8. Shear viscosity, cavitation and hydrodynamics at LHC

    E-Print Network [OSTI]

    Jitesh R. Bhatt; Hiranmaya Mishra; V. Sreekanth

    2011-09-28T23:59:59.000Z

    We study evolution of quark-gluon matter in the ultrarelativistic heavy-ion collisions within the frame work of relativistic second-order viscous hydrodynamics. In particular, by using the various prescriptions of a temperature-dependent shear viscosity to the entropy ratio, we show that the hydrodynamic description of the relativistic fluid become invalid due to the phenomenon of cavitation. For most of the initial conditions relevant for LHC, the cavitation sets in very early during the evolution of the hydrodynamics in time $\\lesssim 2 $fm/c. The cavitation in this case is entirely driven by the large values of shear viscosity. Moreover we also demonstrate that the conformal term used in equations of the relativistic dissipative hydrodynamic can influence the cavitation time.

  9. Shear flow pumping in open microfluidic systems

    E-Print Network [OSTI]

    Markus Rauscher; S. Dietrich; Joel Koplik

    2006-10-26T23:59:59.000Z

    We propose to drive open microfluidic systems by shear in a covering fluid layer, e.g., oil covering water-filled chemical channels. The advantages as compared to other means of pumping are simpler forcing and prevention of evaporation of volatile components. We calculate the expected throughput for straight channels and show that devices can be built with off-the-shelf technology. Molecular dynamics simulations suggest that this concept is scalable down to the nanoscale.

  10. Magnet Technology for Power Converters: Nanocomposite Magnet Technology for High Frequency MW-Scale Power Converters

    SciTech Connect (OSTI)

    None

    2012-02-27T23:59:59.000Z

    Solar ADEPT Project: CMU is developing a new nanoscale magnetic material that will reduce the size, weight, and cost of utility-scale PV solar power conversion systems that connect directly to the grid. Power converters are required to turn the energy that solar power systems create into useable energy for the grid. The power conversion systems made with CMU’s nanoscale magnetic material have the potential to be 150 times lighter and significantly smaller than conventional power conversion systems that produce similar amounts of power.

  11. Direct Numerical Simulation of Surfactant-Stabilized Emulsions Morphology and Shear Viscosity in Starting Shear Flow

    SciTech Connect (OSTI)

    Roar Skartlien; Espen Sollum; Andreas Akselsen; Paul Meakin

    2012-07-01T23:59:59.000Z

    A 3D lattice Boltzmann model for two-phase flow with amphiphilic surfactant was used to investigate the evolution of emulsion morphology and shear stress in starting shear flow. The interfacial contributions were analyzed for low and high volume fractions and varying surfactant activity. A transient viscoelastic contribution to the emulsion rheology under constant strain rate conditions was attributed to the interfacial stress. For droplet volume fractions below 0.3 and an average capillary number of about 0.25, highly elliptical droplets formed. Consistent with affine deformation models, gradual elongation of the droplets increased the shear stress at early times and reduced it at later times. Lower interfacial tension with increased surfactant activity counterbalanced the effect of increased interfacial area, and the net shear stress did not change significantly. For higher volume fractions, co-continuous phases with a complex topology were formed. The surfactant decreased the interfacial shear stress due mainly to advection of surfactant to higher curvature areas. Our results are in qualitative agreement with experimental data for polymer blends in terms of transient interfacial stresses and limited enhancement of the emulsion viscosity at larger volume fractions where the phases are co-continuous.

  12. Design and operation of a thermionic converter in air

    SciTech Connect (OSTI)

    Horner, M.H.; Begg, L.L.; Smith, J.N. Jr. [General Atomics, San Diego, CA (United States); Geller, C.B.; Kallnowski, J.E. [Westinghouse Electric Corp., West Mifflin, PA (United States). Bettis Atomic Power Lab.

    1995-01-01T23:59:59.000Z

    An electrically heated thermionic converter has been designed, built and successfully tested in air. Several unique features were incorporated in this converter: an integral cesium reservoir, innovative ceramic-to-metal seals, a heat rejection system coupling the collector to a low temperature heat sink and an innovative cylindrical heater filament. The converter was operated for extended periods of time with the emitter at about 1900 K. the collector at about 700 K, and a power density of over 2 w(e)/sq. cm. Input power transients were run between 50% and 100% thermal power, at up to 1% per second, without instabilities in performance.

  13. Ion trapping in the emitter sheath in thermionic converters

    SciTech Connect (OSTI)

    Lundgren, L.

    1985-12-01T23:59:59.000Z

    The effect of ion trapping in the emitter sheath in ignited thermionic converters is studied. The ion trapping prevents the emitter-sheath barrier from being higher than approximately 0.1 eV, when the current decreases in the converter. This gives a condition for the constriction of the arc. I-V curves are calculated for an ignited thermionic converter with a hydrodynamic plasma theory that takes into account the effect of Coulomb scattering and volume recombination, but assumes that the electron temperature is constant in the plasma.

  14. Prediction of core saturation instability at an HVDC converter

    SciTech Connect (OSTI)

    Burton, R.S. [Teshmont Consultants, Inc., Winnipeg, Manitoba (Canada)] [Teshmont Consultants, Inc., Winnipeg, Manitoba (Canada); Fuchshuber, C.F. [Alberta Power Ltd., Edmonton, Alberta (Canada)] [Alberta Power Ltd., Edmonton, Alberta (Canada); Woodford, D.A. [Manitoba HVDC Research Centre, Winnipeg, Manitoba (Canada)] [Manitoba HVDC Research Centre, Winnipeg, Manitoba (Canada); Gole, A.M. [Univ. of Manitoba, Winnipeg, Manitoba (Canada)] [Univ. of Manitoba, Winnipeg, Manitoba (Canada)

    1996-10-01T23:59:59.000Z

    Core saturation instability has occurred on several HVDC schemes resulting from interactions between second harmonic and dc quantities (voltages and currents) on the ac side of the converter and fundamental frequency quantities on the dc side of the converter. The instability can be reinforced by unbalanced saturation of the converter transformers. The paper presents an analytical method which can be used to quickly screen ac and dc system operating conditions to predict where core saturation instability is likely to occur. Analytical results have been confirmed using the digital transients simulation program PSCAD/EMTDC.

  15. Vehicle Technologies Office Merit Review 2014: WBG Converters and Chargers

    Broader source: Energy.gov [DOE]

    Presentation given by Oak Ridge National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about WBG converters...

  16. Method for converting uranium oxides to uranium metal

    DOE Patents [OSTI]

    Duerksen, Walter K. (Norris, TN)

    1988-01-01T23:59:59.000Z

    A process is described for converting scrap and waste uranium oxide to uranium metal. The uranium oxide is sequentially reduced with a suitable reducing agent to a mixture of uranium metal and oxide products. The uranium metal is then converted to uranium hydride and the uranium hydride-containing mixture is then cooled to a temperature less than -100.degree. C. in an inert liquid which renders the uranium hydride ferromagnetic. The uranium hydride is then magnetically separated from the cooled mixture. The separated uranium hydride is readily converted to uranium metal by heating in an inert atmosphere. This process is environmentally acceptable and eliminates the use of hydrogen fluoride as well as the explosive conditions encountered in the previously employed bomb-reduction processes utilized for converting uranium oxides to uranium metal.

  17. DOE Announces Webinars on the Wave Energy Converter Prize, the...

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

    Best of the Clean Cities Tools and Resources, and More DOE Announces Webinars on the Wave Energy Converter Prize, the Best of the Clean Cities Tools and Resources, and More March...

  18. Sandia National Laboratories: WEC-Sim (Wave Energy Converter...

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

    and Y. Yu, "Preliminary Verification and Validation of WEC-Sim, an Open-Source Wave Energy Converter Design Tool," in Proceedings of OMAE 2014, San Francisco, CA, 2014. 2...

  19. Multilevel Converter Topologies for Utility Scale Solar Photovoltaic Power Systems

    E-Print Network [OSTI]

    Essakiappan, Somasundaram

    2014-04-30T23:59:59.000Z

    and phase angle of the inverter cells is proposed. This improves differential power processing amongst cells while keeping the voltage and current ratings of the devices low. A battery energy storage system for the multilevel PV converter has also been...

  20. Multiplatform Dynamic System Simulation of a DC-DC Converter.

    E-Print Network [OSTI]

    Song, Wenpeng

    2012-01-01T23:59:59.000Z

    ??The work presented in this paper focuses on the usability testing for the Open-Modelica. The modeling and simulation of the BMR450 DC-DC converter is also… (more)

  1. A global maximum power point tracking DC-DC converter

    E-Print Network [OSTI]

    Duncan, Joseph, 1981-

    2005-01-01T23:59:59.000Z

    This thesis describes the design, and validation of a maximum power point tracking DC-DC converter capable of following the true global maximum power point in the presence of other local maximum. It does this without the ...

  2. Idaho Application for Permit to Convert a Geothermal Injection...

    Open Energy Info (EERE)

    navigation, search OpenEI Reference LibraryAdd to library Form: Idaho Application for Permit to Convert a Geothermal Injection Well - Form 4003-3 Form Type ApplicationNotice Form...

  3. Protocols for the Equitable Assessment of Marine Energy Converters 

    E-Print Network [OSTI]

    Ingram, David; Smith, George; Bittencourt-Ferreira, Claudio; Smith, Helen

    This book contains the suite of protocols for the equitable evaluation of marine energy converters (based on either tidal or wave energy) produced by the EquiMar consortium led by the University of Edinburgh. These protocols ...

  4. Second Order Geodesic Corrections to Cosmic Shear

    E-Print Network [OSTI]

    S. Dodelson; E. W. Kolb; S. Matarrese; A. Riotto; P. Zhang

    2005-03-07T23:59:59.000Z

    We consider the impact of second order corrections to the geodesic equation governing gravitational lensing. We start from the full second order metric, including scalar, vector and tensor perturbations, and retain all relevant contributions to the cosmic shear corrections that are second order in the gravitational potential. The relevant terms are: the nonlinear evolution of the scalar gravitational potential, the Born correction, and lens-lens coupling. No other second order terms contribute appreciably to the lensing signal. Since ray-tracing algorithims currently include these three effects, this derivation serves as rigorous justification for the numerical predictions.

  5. Optimisation of Shear Strengthened Reinforced Concrete Beams

    E-Print Network [OSTI]

    Yapa, Hiran D.; Lees, Janet M.

    2014-05-21T23:59:59.000Z

    strain 82 #3;1, #3;2 principal strains ? inclination of the principal compressive strain direction relative to the x (longitudinal) direction rx, rz steel reinforcement ratio in the longitudinal and transverse directions 1. Introduction Shear failures... for rectangular (Kesse and Lees, 2007a) or slab-on-beam structures (Hoult and Lees, 2009a). The CFRP strap is made by winding layers of thin (between 0.12 mm and 0.16 mm thick) continuous CFRP thermo- plastic tape around the beam. Profiled steel bearing pads...

  6. Hysteresis and Lubrication in Shear Thickening of Cornstarch Suspensions

    E-Print Network [OSTI]

    Clarence E. Chu; Joel A. Groman; Hannah L. Sieber; James G. Miller; Ruth J. Okamoto; Jonathan I. Katz

    2014-05-28T23:59:59.000Z

    Aqueous and brine suspensions of corn starch show striking discontinuous shear thickening. We have found that a suspension shear-thickened throughout may remain in the jammed thickened state as the strain rate is reduced, but an unjamming front may propagate from any unjammed regions. Transient shear thickening is observed at strain rates below the thickening threshold, and above it the stress fluctuates. The jammed shear-thickened state may persist to low strain rates, with stresses resembling sliding friction and effective viscosity inversely proportional to the strain rate. At the thickening threshold fluid pressure depins the suspension's contact lines on solid boundaries so that it slides, shears, dilates and jams. In oil suspensions lubrication and complete wetting of confining surfaces eliminate contact line forces and prevent jamming and shear thickening, as does addition of immiscible liquid surfactant to brine suspensions. Starch suspensions in glycerin-water solutions, viscous but incompletely wetting, have intermediate properties.

  7. Design issues for high voltage converters for ion engines

    SciTech Connect (OSTI)

    King, R.J.; Stuart, T.A. [Univ. of Toledo, OH (United States)

    1995-12-31T23:59:59.000Z

    A design strategy is presented for a power converter for a high voltage ion engine for a spacecraft application. Various design issues such as appropriate topologies and control methods are considered. In this particular instance it was determined that a full bridge converter with phase shift gating and voltage mode control provided an efficient system with a minimum of electromagnetic interference. This system can be implemented in a straightforward manner, and it is relatively easy to protect from faults at the output.

  8. Formation of double-valued sheaths in thermionic converters

    SciTech Connect (OSTI)

    Lundgren, L.

    1983-08-01T23:59:59.000Z

    A theory for the sheath in an ignited thermionic converter is presented. The theory includes the effect of the velocity spread of the particles but the charge-particle collisions are neglected. Conditions for the appearance of a virtual emitter are given. The theory is compared with a beam approximation theory and a hydrodynamic theory. All three theories give almost the same condition for the appearance of a virtual emitter in an ignited thermionic converter.

  9. Bi-directional power control system for voltage converter

    DOE Patents [OSTI]

    Garrigan, N.R.; King, R.D.; Schwartz, J.E.

    1999-05-11T23:59:59.000Z

    A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals. 10 figs.

  10. Bi-directional power control system for voltage converter

    DOE Patents [OSTI]

    Garrigan, Neil Richard (Niskayuna, NY); King, Robert Dean (Schenectady, NY); Schwartz, James Edward (Slingerlands, NY)

    1999-01-01T23:59:59.000Z

    A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals.

  11. Anomalous shear wave attenuation in the shallow crust beneath...

    Open Energy Info (EERE)

    Anomalous shear wave attenuation in the shallow crust beneath the Coso volcanic region, California Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

  12. Simulated performance of an airborne lidar wind shear detection system

    E-Print Network [OSTI]

    Griffith, Kenneth Scott

    2012-06-07T23:59:59.000Z

    in the microburst test case. Journal model is Applied Optics. CHAPTER II THE WIND SHEAR HAZARD 2. 1 The Wind Shear Phenomenon Wind shear can be defined as a change in wind direction and/or speed over relatively short distances. i Wind shear can occur at any... and sea ? breeze fronts. These clear air winds move at speeds of 15 to 40 knots over large distances. rhtrrM~s Prost i ? arhiog the ar e of t a sitio bet eea t o separate ai masses having different temperatures and humidities. The change in wind...

  13. Shear Jamming in Granular Experiments without Basal Friction

    E-Print Network [OSTI]

    Hu Zheng; Joshua A. Dijksman; Robert P. Behringer

    2014-04-29T23:59:59.000Z

    Jammed states of frictional granular systems can be induced by shear strain at densities below the isostatic jamming density ($\\phi_c$). It remains unclear, however, how much friction affects this so-called shear-jamming. Friction appears in two ways in this type of experiment: friction between particles, and friction between particles and the base on which they rest. Here, we study how particle-bottom friction, or basal friction, affects shear jamming in quasi-two dimensional experiments. In order to study this issue experimentally, we apply simple shear to a disordered packing of photoelastic disks. We can tune the basal friction of the particles by immersing the particles in a density matched liquid, thus removing the normal force, hence the friction, between the particles and base. We record the overall shear stress, and particle motion, and the photoelastic response of the particles. We compare the shear response of dry and immersed samples, which enables us to determine how basal friction affects shear jamming. Our findings indicate that changing the basal friction shifts the point of shear jamming, but it does not change the basic phenomenon of shear jamming.

  14. Present Day Kinematics of the Eastern California Shear Zone from...

    Open Energy Info (EERE)

    Kinematics of the Eastern California Shear Zone from a Geodetically Constrained Block Model Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

  15. A New Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Physical Parameters

    E-Print Network [OSTI]

    Victoria, University of

    A New Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Physical of Mechanical Engineering) ABSTRACT Within a wave energy converter's operational bandwidth, device operation

  16. An evaluation of a parallel-resonant current-source converter for an electrothermal thruster

    E-Print Network [OSTI]

    Tchamdjou, Aristide-Marie

    1996-01-01T23:59:59.000Z

    The Parallel-Resonant Current-Source Converter promises highly efficient DCDC power conversion. It uses zero-voltage switching to reduce the losses and improve the converter efficiency. The Parallel-Resonant Current-Source Converter has been...

  17. Analysis and design of a high power dc-dc converter

    E-Print Network [OSTI]

    Husain, Iqbal

    1989-01-01T23:59:59.000Z

    rating of this converter is virtually unlimited. Similar converter topologies are used in HVDC power transmission in utility power systems. The rating of these HVDC converters can exceed 1000 MVA. The ac link capacttor. C in the DPC circuit serves...

  18. Shear strength of reinforced geosynthetic clay liner

    SciTech Connect (OSTI)

    Gilbert, R.B. [Univ. of Texas, Austin, TX (United States)] [Univ. of Texas, Austin, TX (United States); Fernandez, F. [Golder Associates, Inc., Naperville, IL (United States)] [Golder Associates, Inc., Naperville, IL (United States); Horsfield, D.W. [Golder Associates, Ltd., Calgary, Alberta (Canada)] [Golder Associates, Ltd., Calgary, Alberta (Canada)

    1996-04-01T23:59:59.000Z

    Direct shear tests are conducted to evaluate the internal strength of a reinforced geosynthetic clay liner (GCL) at normal stresses between 3.45 and 69.0 kPa. The polypropylene reinforcement increases the peak internal strength compared to that reported in the literature for unreinforced GCLs; however, the reinforced GCL exhibits a postpeak reduction in strength with displacement due to failure of the reinforcement. Direct shear tests are also conducted to evaluate the interface strength between the reinforced GCL and other geosynthetic materials. Extrusion of bentonite from the GCL into the interfaces is noticed and may reduce the interface strengths. Peak interface strengths between the GCL and a smooth geomembrane or a drainage geocomposite are less than the internal strength at all normal stresses tested. However, the peak interface strength between the GCL and a textured geomembrane is limited by the peak internal strength for normal stresses exceeding 13.8 kPa. Postpeak reductions in strength with displacement occur for this interface at these higher normal stresses due to reinforcement failure.

  19. angiotensin-i converting enzyme: Topics by E-print Network

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

    Websites Summary: - Resonant converters and related systems, such as piezoelectric transformers, may require a high of resonant converters: a series-resonant parallel-...

  20. E-Print Network 3.0 - ad converter system Sample Search Results

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

    Summary: method to reconstruct several classical dc-dc converters, a voltage source inverter (VSI), and a current... introduces some new topologies of dc-dc converters that...

  1. A Solid Core Heatpipe Reactor with Cylindrical Thermoelectric Converter Modules

    SciTech Connect (OSTI)

    Sayre, Edwin D. [218 Brooke Acres Drive, Los Gatos, CA 95032 (United States); Vaidyanathan, Sam [6663 Pomander Place, San Jose, CA 95120 (United States)

    2006-01-20T23:59:59.000Z

    A nuclear space power system that consists of a solid metal nuclear reactor core with heat pipes carrying energy to a cylindrical thermoelectric converter surrounding each of the heat pipes with a heat pipe radiator surrounding the thermoelectric converter is the most simple and reliable space power system. This means no single point of failure since each heat pipe and cylindrical converter is a separate power system and if one fails it will not affect the others. The heat pipe array in the solid core is designed so that if an isolated heat pipe or even two adjacent heat pipes fail, the remaining heat pipes will still transport the core heat without undue overheating of the uranium nitride fuel. The primary emphasis in this paper is on simplicity, reliability and fabricability of such a space nuclear power source. The core and heat pipes are made of Niobium 1% Zirconium alloy (Nb1Zr), with rhenium lined fuel tubes, bonded together by hot isostatic pressure (HIPing) and with sodium as the heat pipe working fluid, can be operated up to 1250K. The cylindrical thermoelectric converter is made by depositing the constituents of the converter around a Nb1%Zr tube and encasing it in a Nb 1% Zr alloy tube and HIPing the structure to get final bonding and to produce residual compressive stresses in all brittle materials in the converter. A radiator heat pipe filled with potassium that operates at 850K is bonded to the outside of the cylindrical converter for cooling. The solid core heat pipe and cylindrical converter are mated by welding during the final assembly. A solid core reactor with 150 heat pipes with a 0.650-inch (1.65 cm) ID and a 30-inch (76.2 cm) length with an output of 8 Watts per square inch as demonstrated by the SP100 PD2 cell tests will produce about 80 KW of electrical power. An advanced solid core reactor made with molybdenum 47% rhenium alloy, with lithium heat pipes and the PD2 theoretical output of 11 watts per square inch or advanced higher temperature converter to operate at 1350K could produce a greater output of approximately 100KW.

  2. Sub-picosecond Resolution Time-to-Digital Converter

    SciTech Connect (OSTI)

    Ph D, Vladimir Bratov; Ph D, Vladimir Katzman; MS EE, Jeb Binkley

    2006-03-30T23:59:59.000Z

    Time-to-digital converters with sub-picosecond resolutions are needed to satisfy the requirements of time-on-flight measurements of the next generation of high energy and nuclear physics experiments. The converters must be highly integrated, power effective, low cost, and feature plug-and-play capabilities to handle the increasing number of channels (up to hundreds of millions) in future Department of Energy experiments. Current state-off-the-art time-to-digital converter integrated circuits do not have the sufficient degree of integration and flexibility to fulfill all the described requirements. During Phase I, the Advanced Science and Novel Technology Company in cooperation with the nuclear physics division of the Oak Ridge National Laboratory has developed the architecture of a novel time-to-digital converter with multiple channels connected to an external processor through a special interfacing block and synchronized by clock signals generated by an internal phase-locked loop. The critical blocks of the system including signal delay lines and delay-locked loops with proprietary differential delay cells, as well as the required digital code converter and the clock period counter have been designed and simulated using the advanced SiGe120 BiCMOS technological process. The results of investigations demonstrate a possibility to achieve the digitization accuracy within 1ps. ADSANTEC has demonstrated the feasibility of the proposed concept in computer simulations. The proposed system will be a critical component for the next generation of NEP experiments.

  3. Large amplitude oscillatory shear of pseudoplastic and elastoviscoplastic materials

    E-Print Network [OSTI]

    , Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 2 Halliburton amplitude oscillatory shear. A new parameter, the perfect plastic dissipation ratio, is introduced, a pseudoplastic shear-thinning xanthan gum solution and an elastoviscoplastic invert-emulsion drilling fluid

  4. The SDSS Coadd: Cosmic Shear Measurement

    SciTech Connect (OSTI)

    Lin, Huan; /Fermilab; Dodelson, Scott; /Fermilab /Chicago U., EFI /Chicago U., KICP; Seo, Hee-Jong; /UC, Berkeley; Soares-Santos, Marcelle; /Fermilab; Annis, James; /Fermilab; Hao, Jiangang; /Fermilab; Johnston, David; /Fermilab; Kubo, Jeffrey M.; /Fermilab; Reis, Ribamar R.R.; /Fermilab /Rio de Janeiro Federal U.; Simet, Melanie; /Chicago U., EFI /Chicago U., KICP

    2011-11-01T23:59:59.000Z

    Stripe 82 in the Sloan Digital Sky Survey was observed multiple times, allowing deeper images to be constructed by coadding the data. Here we analyze the ellipticities of background galaxies in this 275 square degree region, searching for evidence of distortions due to cosmic shear. The E-mode is detected in both real and Fourier space with > 5-{sigma} significance on degree scales, while the B-mode is consistent with zero as expected. The amplitude of the signal constrains the combination of the matter density {Omega}{sub m} and fluctuation amplitude {sigma}{sub 8} to be {Omega}{sub m}{sup 0.7} {sigma}{sub 8} = 0.276{sub -0.050}{sup +0.036}.

  5. Adjustable shear stress erosion and transport flume

    DOE Patents [OSTI]

    Roberts, Jesse D. (Carlsbad, NM); Jepsen, Richard A. (Carlsbad, NM)

    2002-01-01T23:59:59.000Z

    A method and apparatus for measuring the total erosion rate and downstream transport of suspended and bedload sediments using an adjustable shear stress erosion and transport (ASSET) flume with a variable-depth sediment core sample. Water is forced past a variable-depth sediment core sample in a closed channel, eroding sediments, and introducing suspended and bedload sediments into the flow stream. The core sample is continuously pushed into the flow stream, while keeping the surface level with the bottom of the channel. Eroded bedload sediments are transported downstream and then gravitationally separated from the flow stream into one or more quiescent traps. The captured bedload sediments (particles and aggregates) are weighed and compared to the total mass of sediment eroded, and also to the concentration of sediments suspended in the flow stream.

  6. Saturation of elliptic flow and shear viscosity

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2007-10-08T23:59:59.000Z

    Effect of shear viscosity on elliptic flow is studied in causal dissipative hydrodynamics in 2+1 dimensions. Elliptic flow is reduced in viscous dynamics. Causal evolution of minimally viscous fluid ($\\eta/s$=0.08), can explain the PHENIX data on elliptic flow in 16-23% Au+Au collisions up to $p_T\\approx$3.6 GeV. In contrast, ideal hydrodynamics, can explain the same data only up to $p_T\\approx$1.5 GeV. $p_T$ spectra of identified particles are also better explained in minimally viscous fluid than in ideal dynamics. However, saturation of elliptic flow at large $p_T$ is not reproduced.

  7. Density waves in the shearing sheet I. Swing amplification

    E-Print Network [OSTI]

    B. Fuchs

    2001-03-02T23:59:59.000Z

    The shearing sheet model of a galactic disk is studied anew. The theoretical description of its dynamics is based on three building blocks: Stellar orbits, which are described here in epicyclic approximation, the collisionless Boltzmann equation determining the distribution function of stars in phase space, and the Poisson equation in order to take account of the self-gravity of the disk. Using these tools I develop a new formalism to describe perturbations of the shearing sheet. Applying this to the unbounded shearing sheet model I demonstrate again how the disturbances of the disk evolve always into `swing amplified' density waves, i.e. spiral-arm like, shearing density enhancements, which grow and decay while the wave crests swing by from leading to trailing orientation. Several examples are given how such `swing amplification' events are incited in the shearing sheet.

  8. Methods for degrading or converting plant cell wall polysaccharides

    DOE Patents [OSTI]

    Berka, Randy (Davis, CA); Cherry, Joel (Davis, CA)

    2008-08-19T23:59:59.000Z

    The present invention relates to methods for converting plant cell wall polysaccharides into one or more products, comprising: treating the plant cell wall polysaccharides with an effective amount of a spent whole fermentation broth of a recombinant microorganism, wherein the recombinant microorganism expresses one or more heterologous genes encoding enzymes which degrade or convert the plant cell wall polysaccharides into the one or more products. The present invention also relates to methods for producing an organic substance, comprising: (a) saccharifying plant cell wall polysaccharides with an effective amount of a spent whole fermentation broth of a recombinant microorganism, wherein the recombinant microorganism expresses one or more heterologous genes encoding enzymes which degrade or convert the plant cell wall polysaccharides into saccharified material; (b) fermenting the saccharified material of step (a) with one or more fermenting microoganisms; and (c) recovering the organic substance from the fermentation.

  9. Power line carrier interference from HVDC converter terminals

    SciTech Connect (OSTI)

    Tatro, P.J.; Adamson, K.A. (New England Power Service Co., Westborough, MA (United States)); Eitzmann, M.A.; Smead, M. (GE Industrial and Power Systems, Schenectady, NY (United States). Power Systems Engineering Dept.)

    1993-07-01T23:59:59.000Z

    Power line carrier (PLC) equipment typically operates in the frequency range from 25 kHz to 300 kHz. Interference studies for HVDC converters usually concentrate on interference from noise sources within this frequency range. However, operating experience at the Sandy Pond converter terminal has indicated that PLC equipment is also susceptible to interference from sources of power system harmonics below the PLC frequency range. Extensive field testing and analytical studies have shown that each PLC circuit has a resonant frequency below the operating frequency. If excited at this resonant frequency, high voltages may exist within the PLC circuit. The resulting saturation of PLC components leads to local generation of radio frequency (RF) noise that interferes with proper operation of PLC circuits. Sources of power system harmonics in the 3-10 kHz range, such as line commutated dc converters, are potential sources of this type of interference.

  10. E-Print Network 3.0 - average wind shear Sample Search Results

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

    wind shear Search Powered by Explorit Topic List Advanced Search Sample search results for: average wind shear Page: << < 1 2 3 4 5 > >> 1 Analysis of wind shear models and trends...

  11. Influence of inherent structure shear stress of supercooled liquids on their shear moduli

    E-Print Network [OSTI]

    Ingo Fuereder; Patrick Ilg

    2015-04-13T23:59:59.000Z

    Configurations of supercooled liquids residing in their local potential minimum (i.e. in their inherent structure, IS) were found to support a non-zero shear stress. This IS stress was attributed to the constraint to the energy minimization imposed by boundary conditions, which keep size and shape of the simulation cell fixed. In this paper we further investigate the influence of these boundary conditions on the IS stress. We investigate its importance for the computation of the low frequency shear modulus of a glass obtaining a consistent picture for the low- and high frequency shear moduli over the full temperature range. Hence, we find that the IS stress corresponds to a non-thermal contribution to the fluctuation term in the Born-Green expression. This leads to an unphysical divergence of the moduli in the low temperature limit if no proper correction for this term is applied. Furthermore, we clarify the IS stress dependence on the system size and put its origin on a more formal basis.

  12. The combined effects of beta-shear and environmental shear on a dry tropical cyclone in a numerical model

    E-Print Network [OSTI]

    Nolan, David S.

    wind balance is analyzed in this study (Mallen et al. 2005). The vortex is generated from a number, FL 1. INTRODUCTION High values of vertical wind shear have been shown to inhibit tropical cyclone (TC have demonstrated that shear generates a tilt in TC core, resulting in persistent wavenumber-1

  13. Method for converting sucrose to .beta.-D-glucose

    DOE Patents [OSTI]

    Simmons, Blake A. (San Francisco, CA); Volponi, Joanne V. (Livermore, CA); Ingersoll, David (Albuquerque, NM); Walker, Andrew (Woodinville, WA)

    2009-07-07T23:59:59.000Z

    Disclosed is an apparatus and method for continuously converting sucrose to .beta.-D-glucose. The method comprises a three-stage enzymatic reactor in which an aqueous solution of sucrose is first converted into a solution of fructose and .alpha.-D-glucose by passing it through a porous, packed column containing an inert media on which invertase is immobilized. This solution is then sent through a second packed column containing glucose isomerase and finally a third packed column containing mutarotase. Solution temperature and pH are adjusted to maximize glucose output.

  14. The important effect of electron reflection on thermionic converter performance

    SciTech Connect (OSTI)

    Rasor, N.S.

    1998-07-01T23:59:59.000Z

    Although only a few percent of high energy electrons are reflected from bare metal surfaces, 20--60% of low energy incident electrons are reflected from thermionic converter electrodes with adsorbed cesium and oxygen. The TECMDL computer model indicates that electron reflection in cesium vapor thermionic converters increases the arc potential drop, offsetting the gain in performance obtainable by lowering the collector work function via the coadsorbed Cs/O layer. The possible suppression of electron reflection by using electrodes with sub-micron surface structure is hypothesized and supported by experimental data obtained by employing a new method for testing in cesium-oxygen vapor.

  15. Effect of normal stress during hydration and shear on the shear strength of GCL/textured geomembrane interfaces

    SciTech Connect (OSTI)

    Hewitt, R.D.; Soydemir, C. [Haley and Aldrich, Inc., Cambridge, MA (United States); Stulgis, R.P. [Haley and Aldrich, Inc., Manchester, NH (United States); Coombs, M.T. [Tufts Univ., Medford, MA (United States)

    1997-11-01T23:59:59.000Z

    A laboratory testing program was performed to evaluate the interface shear strength of a geosynthetic clay liner (GCL)/textured geomembrane interface utilizing two pre-shear inundation methods designed to simulate field conditions. Two commercially-available products were tested, a needlepunched and a stitch-bonded GCL. Oedometer swell tests provided swell data for the two products which were used to design the interface shear testing program. Interface shear tests were performed for (1) GCL samples inundated under a low normal stress for a short time and sheared under a higher normal stress, and (2) GCL samples inundated for a longer period under the design normal stress. The results for the two different GCL materials and the two preshear inundation conditions are compared.

  16. Northwest Energy Innovations (TRL 5 6 System)- WETNZ MtiMode Wave Energy Converter Advancement Project

    Broader source: Energy.gov [DOE]

    Northwest Energy Innovations (TRL 5 6 System) - WETNZ MtiMode Wave Energy Converter Advancement Project

  17. High speed bypass Fig. 1. Sub-module of MMC converter

    E-Print Network [OSTI]

    Chaudhary, Sanjay

    Modular Converter for VSC-HVDC Transmission Applications: Control and Operational Aspects Udana N, the multilevel modular converter (MMC), recently introduced for HVDC transmission are discussed. The paper. Keywords-Voltage Source Convert (VSC), Multilevel Modular Converter (MMC), HVDC Transmission, Weak ac

  18. Adjuvant Radiotherapy for Gastric Cancer: A Dosimetric Comparison of 3-Dimensional Conformal Radiotherapy, Tomotherapy (registered) and Conventional Intensity Modulated Radiotherapy Treatment Plans

    SciTech Connect (OSTI)

    Dahele, Max [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Skinner, Matthew; Schultz, Brenda; Cardoso, Marlene; Bell, Chris [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Ung, Yee C. [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada)], E-mail: yee.ung@sunnybrook.ca

    2010-07-01T23:59:59.000Z

    Some patients with gastric cancer benefit from post-operative chemo-radiotherapy, but adequately irradiating the planning target volume (PTV) whilst avoiding organs at risk (OAR) can be difficult. We evaluate 3-dimensional conformal radiotherapy (CRT), conventional intensity-modulated radiotherapy (IMRT) and helical tomotherapy (TT). TT, 2 and 5-field (F) CRT and IMRT treatment plans with the same PTV coverage were generated for 5 patients and compared. Median values are reported. The volume of left/right kidney receiving at least 20Gy (V20) was 57/51% and 51/60% for 2 and 5F-CRT, and 28/14% for TT and 27/19% for IMRT. The volume of liver receiving at least 30Gy (V30) was 45% and 62% for 2 and 5F-CRT, and 37% for TT and 35% for IMRT. With TT, 98% of the PTV received 95-105% of the prescribed dose, compared with 45%, 34% and 28% for 2F-CRT, 5F-CRT and IMRT respectively. Using conventional metrics, conventional IMRT can achieve comparable PTV coverage and OAR sparing to TT, but at the expense of PTV dose heterogeneity. Both irradiate large volumes of normal tissue to low doses. Additional studies are needed to demonstrate the clinical impact of these technologies.

  19. The Viability of Sustainable, Self-Propping Shear Zones in Ehanced...

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

    Self-Propping Shear Zones in Ehanced Geothermal Systems: Measurement of Reaction Rates at Elevated Temperatures The Viability of Sustainable, Self-Propping Shear Zones in...

  20. A Shear Thickening transition in concentrated suspensions under Impact

    E-Print Network [OSTI]

    Shomeek Mukhopadhyay; Benjamin Allen; Eric Brown

    2014-07-07T23:59:59.000Z

    Discontinous Shear Thickening (DST) fluids show a remarkable effect where the suspension behaves like a liquid at low shear rates, but when sheared very hard, resistance to flow increases discontinously with shear rate. This effect has been observed in a large variety of concentrated suspensions of hard, frictional and non attractive particles. DST fluids also show strong impact response such as the ability of a person to run on the surface of a pool filled with a suspension of cornstarch and water. Current models of shear thickening based on lubrication hydrodynamics, dilatancy, and inertial displacement fail to explain the ability of a person to run on the surface and impact response in general. In our experiments we discover a transition at a critical impact velocity in DST fluids above which fronts of solid like regions are generated in the fluid and the collision of these fronts with a solid boundary leads to a shear thickening transition which has not been previously predicted or reported. The large stresses generated above the shear thickening transition are enough to hold up the weight of a person and have potential applications for protective materials.

  1. Variable-amplitude oscillatory shear response of amorphous materials

    E-Print Network [OSTI]

    Nathan Perchikov; Eran Bouchbinder

    2014-04-13T23:59:59.000Z

    Variable-amplitude oscillatory shear tests are emerging as powerful tools to investigate and quantify the nonlinear rheology of amorphous solids, complex fluids and biological materials. Quite a few recent experimental and atomistic simulation studies demonstrated that at low shear amplitudes, an amorphous solid settles into an amplitude- and initial conditions-dependent dissipative limit cycle, in which back-and-forth localized particle rearrangements periodically bring the system to the same state. At sufficiently large shear amplitudes, the amorphous system loses memory of the initial conditions, exhibits chaotic particle motions accompanied by diffusive behavior and settles into a stochastic steady-state. The two regimes are separated by a transition amplitude, possibly characterized by some critical-like features. Here we argue that these observations support some of the physical assumptions embodied in the nonequilibrium thermodynamic, internal-variables based, Shear-Transformation-Zone model of amorphous visco-plasticity; most notably that "flow defects" in amorphous solids are characterized by internal states between which they can make transitions, and that structural evolution is driven by dissipation associated with plastic deformation. We present a rather extensive theoretical analysis of the thermodynamic Shear-Transformation-Zone model for a variable-amplitude oscillatory shear protocol, highlighting its success in accounting for various experimental and simulational observations, as well as its limitations. Our results offer a continuum-level theoretical framework for interpreting the variable-amplitude oscillatory shear response of amorphous solids and may promote additional developments.

  2. An improved viscosity equation to characterize shear-thinning fluids

    SciTech Connect (OSTI)

    Allen, E.

    1995-11-01T23:59:59.000Z

    An improved viscosity equation is proposed for shear-thinning polymer solutions, using a kinetic approach to model the rate of formation and loss of interactive bonding during shear flow. The bonds are caused by temporary polymer entanglements in polymer solutions, and by coordination bonding in metal ion cross-linked gels. The equation characterizes the viscosity of shear-thinning fluids over a wide range of shear rates, from the zero shear region through to infinite shear viscosity. The equation has been used to characterize fluid data from a wide range of fluids. Recent work indicates that a range of polymer solutions, polymer-based drilling fluids and frac-gels do not have a measurable yield stress, and that the equations which use extrapolated values of yield stress can be significantly in error. The new equation is compared with the Carreau and Cross equations, using the correlation procedure of Churchill and Usagi. It gives a significantly better fit to the data (by up to 50%) over a wide range of shear rates. The improved equation can be used for evaluating the fluid viscosity during the flow of polymeric fluids, in a range of oilfield applications including drilling, completion, stimulation and improved recovery (IOR) processes.

  3. Shear band dynamics from a mesoscopic modeling of plasticity

    E-Print Network [OSTI]

    E. A. Jagla

    2010-06-07T23:59:59.000Z

    The ubiquitous appearance of regions of localized deformation (shear bands) in different kinds of disordered materials under shear is studied in the context of a mesoscopic model of plasticity. The model may or may not include relaxational (aging) effects. In the absence of relaxational effects the model displays a monotonously increasing dependence of stress on strain-rate, and stationary shear bands do not occur. However, in start up experiments transient (although long lived) shear bands occur, that widen without bound in time. I investigate this transient effect in detail, reproducing and explaining a t^1/2 law for the thickness increase of the shear band that has been obtained in atomistic numerical simulations. Relaxation produces a negative sloped region in the stress vs. strain-rate curve that stabilizes the formation of shear bands of a well defined width, which is a function of strain-rate. Simulations at very low strain-rates reveal a non-trivial stick-slip dynamics of very thin shear bands that has relevance in the study of seismic phenomena. In addition, other non-stationary processes, such as stop-and-go, or strain-rate inversion situations display a phenomenology that matches very well the results of recent experimental studies.

  4. A13G-0330: Evaluation of 3-dimensional winds measured by the Aircraft Integrated Meteorological Measurement System (AIMMS) Christopher G Kruse, David J Delene, and Cedric Grainger, University of North Dakota (christopher.kruse@und.edu)

    E-Print Network [OSTI]

    Delene, David J.

    A13G-0330: Evaluation of 3-dimensional winds measured by the Aircraft Integrated Meteorological, and IMU to derive the winds. The IMU and CPU were mounted in the cabin, the ADP was mounted under The time intervals and mean magnitude of vertical wind during the straight and level and porpoise maneuvers

  5. Statement of Interest in a New Project, in response to PPARC call of April 26th FHIRN: A next-generation radio network for exploring the 3-dimensional solar wind

    E-Print Network [OSTI]

    -situ. The heliospheric white-light imagers to be carried on STEREO should extend the ability to estimate solar wind-generation radio network for exploring the 3-dimensional solar wind Future Heliospheric Imaging Radio Network The solar wind is a supersonically-expanding extension of the solar atmosphere into interplanetary space

  6. Control and Power Management of Converter Fed Microgrids

    E-Print Network [OSTI]

    Lehn, Peter W.

    1 Control and Power Management of Converter Fed Microgrids Charles K. Sao, Member, IEEE, and Peter in parallel in a VSC fed microgrid. Each current controlled VSC in such a microgrid has its own VPD/FQB controller that sets its current references to regulate the voltage and frequency of a common microgrid bus

  7. Pre-converted nitric oxide gas in catalytic reduction system

    DOE Patents [OSTI]

    Hsiao, Mark C. (Livermore, CA); Merritt, Bernard T. (Livermore, CA); Penetrante, Bernardino M. (San Ramon, CA); Vogtlin, George E. (Fremont, CA)

    1999-01-01T23:59:59.000Z

    A two-stage catalyst comprises an oxidative first stage and a reductive second stage. The first stage is intended to convert NO to NO.sub.2 in the presence of O.sub.2. The second stage serves to convert NO.sub.2 to environmentally benign gases that include N2, CO2, and H.sub.2 O. By preconverting NO to NO.sub.2 in the first stage, the efficiency of the second stage for NO.sub.x reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber. An oxidizing first catalyst converts NO to NO.sub.2 in the presence of O.sub.2 and includes platinum/alumina, e.g., Pt/Al.sub.2 O.sub.3 catalyst. A flow of hydrocarbons (C.sub.x H.sub.y) is input from a pipe into a second chamber. For example, propene can be used as a source of hydrocarbons. The NO.sub.2 from the first catalyst mixes with the hydrocarbons in the second chamber. The mixture proceeds to a second reduction catalyst that converts NO.sub.2 to N2, CO2, and H.sub.2 O, and includes a gamma-alumina .gamma.-Al.sub.2 O.sub.3. The hydrocarbons and NO.sub.x are simultaneously reduced while passing through the second catalyst.

  8. Performance Assessment of the Wave Dragon Wave Energy Converter

    E-Print Network [OSTI]

    Hansen, René Rydhof

    Performance Assessment of the Wave Dragon Wave Energy Converter Based on the EquiMar Methodology S of the wave energy sector, device developers are called to provide reliable estimates on power performanceMar, Nissum Bredning, Hanstholm, North Sea, Ekofisk, Wave-to-wire, Wave energy. I. INTRODUCTION The wave

  9. Pre-converted nitric oxide gas in catalytic reduction system

    DOE Patents [OSTI]

    Hsiao, M.C.; Merritt, B.T.; Penetrante, B.M.; Vogtlin, G.E.

    1999-04-06T23:59:59.000Z

    A two-stage catalyst comprises an oxidative first stage and a reductive second stage. The first stage is intended to convert NO to NO{sub 2} in the presence of O{sub 2}. The second stage serves to convert NO{sub 2} to environmentally benign gases that include N{sub 2}, CO{sub 2}, and H{sub 2}O. By preconverting NO to NO{sub 2} in the first stage, the efficiency of the second stage for NO{sub x} reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber. An oxidizing first catalyst converts NO to NO{sub 2} in the presence of O{sub 2} and includes platinum/alumina, e.g., Pt/Al{sub 2}O{sub 3} catalyst. A flow of hydrocarbons (C{sub x}H{sub y}) is input from a pipe into a second chamber. For example, propene can be used as a source of hydrocarbons. The NO{sub 2} from the first catalyst mixes with the hydrocarbons in the second chamber. The mixture proceeds to a second reduction catalyst that converts NO{sub 2} to N{sub 2}, CO{sub 2}, and H{sub 2}O, and includes a {gamma}-Al{sub 2}O{sub 3}. The hydrocarbons and NO{sub x} are simultaneously reduced while passing through the second catalyst. 9 figs.

  10. Multi-level converters for three-phase photovoltaic applications

    E-Print Network [OSTI]

    Lehman, Brad

    Multi-level converters for three-phase photovoltaic applications Renato M. Nakagomi, Ye Zhao, Brad a switching matrix device and photovoltaic (PV) panels. The approach is based on the dynamic reconfiguration photovoltaic PV panels. The number of PV panels that are connected to the load can be altered using dynamic

  11. Energy Savings Assessment for Digital-to-Analog Converter Boxes

    SciTech Connect (OSTI)

    Cheung, Hoi Ying Iris; Meier, Alan; Brown, Richard

    2011-01-18T23:59:59.000Z

    The Digital Television (DTV) Converter Box Coupon Program was administered by the U.S. government to subsidize purchases of digital-to-analog converter boxes, with up to two $40 coupons for each eligible household. In order to qualify as Coupon Eligible Converter Boxes (CECBs), these devices had to meet a number of minimum performance specifications, including energy efficiency standards. The Energy Star Program also established voluntary energy efficiency specifications that are more stringent than the CECB requirements. In this study, we measured the power and energy consumptions for a sample of 12 CECBs (including 6 Energy Star labeled models) in-use in homes and estimated aggregate energy savings produced by the energy efficiency policies. Based on the 35 million coupons redeemed through the end of the program, our analysis indicates that between 2500 and 3700 GWh per year are saved as a result of the energy efficiency policies implemented on digital-to-analog converter boxes. The energy savings generated are equivalent to the annual electricity use of 280,000 average US homes.

  12. Introduction to workshop on spectral control and converters

    SciTech Connect (OSTI)

    Wanlass, M.W.; Schwartz, R.J.

    1995-01-05T23:59:59.000Z

    This workshop focused on the portion of the TPV system that involves the photovoltaic energy converter and the spectral control element that affects subband-gap photon energy recovery. The discussion was divided into three major topic areas: status of the technology, status of the infrastructure, and champions of the technology. (AIP) {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  13. Coupled Dual Interleaved Flyback Converter for High Input Voltage Application

    E-Print Network [OSTI]

    Lehman, Brad

    components, including transformers and inductors, significantly influences the overall profiles magnetic core to store the energy in the power transformer. A Flyback converter is a popular choice for low. All the center and outer legs are gapped, and the transformers are integrated into one magnetic core

  14. Cycling firing method for bypass operation of bridge converters

    SciTech Connect (OSTI)

    Zabar, Zivan (99-72 66th Rd., Apt. 9N, Forest Hills, NY 11375)

    1982-01-01T23:59:59.000Z

    The bridge converter comprises a number of switching elements and an electronic logic system which regulated the electric power levels by controlling the firing, i.e., the initiation of the conduction period of the switching elements. Cyclic firing of said elements allows the direct current to bypass the alternating current system with high power factor and negligible losses.

  15. "Black Box" EMC model for Power Electronics Converter Mikael Foissac

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    "Black Box" EMC model for Power Electronics Converter Mikael Foissac Grenoble Electrical be forecasted accurately, in order to avoid disturbance of the complete system. To quantify the EMC behaviour will then illustrate the method on a complete chopper cell. II. BLACK BOX EMC MODEL Any EMC analysis must account

  16. A summary of North American HVDC converter station reliability specifications

    SciTech Connect (OSTI)

    Vancers, I. (ABB Power Systems Inc., Los Angeles, CA (United States)); Hormozi, F.J. (Los Angeles Dept. of Water and Power, CA (United States))

    1993-07-01T23:59:59.000Z

    This paper summarizes Reliability, Availability, and Maintainability (RAM) specifications that were issued for thyristor based HVDC converter stations in service in North America. A total of twenty project specifications are summarized. A detailed summary by project is shown with specific quantitative requirements categorized. Definitions of terms, representative design principles, and formulas used in calculating RAM parameters contained in existing reliability specifications are presented.

  17. Converting Nested Algebra Expressions into Flat Algebra Expressions

    E-Print Network [OSTI]

    Van Gucht, Dirk

    Converting Nested Algebra Expressions into Flat Algebra Expressions JAN PAREDAENS University of Antwerp and DIRK VAN GUCHT Indiana University Nested relations generalize ordinary flat relations by allowing tuple values to be either atomic or set valued. The nested algebra is a generalization of the flat

  18. A/D Converter Jee-Hwan Ryu

    E-Print Network [OSTI]

    Ryu, Jee-Hwan

    A/D , MUX and REFS update #12;Korea University of Technology and Education ADSC=1 of Technology and Education Korea University of Technology and Education A/D converter #12;Korea University of Technology and Education () AD > -> X = 1 Korea University of Technology and Education AD #12;Korea

  19. Coherent structures in compressible free-shear-layer flows

    SciTech Connect (OSTI)

    Aeschliman, D.P.; Baty, R.S. [Sandia National Labs., Albuquerque, NM (United States). Engineering Sciences Center; Kennedy, C.A.; Chen, J.H. [Sandia National Labs., Livermore, CA (United States). Combustion and Physical Sciences Center

    1997-08-01T23:59:59.000Z

    Large scale coherent structures are intrinsic fluid mechanical characteristics of all free-shear flows, from incompressible to compressible, and laminar to fully turbulent. These quasi-periodic fluid structures, eddies of size comparable to the thickness of the shear layer, dominate the mixing process at the free-shear interface. As a result, large scale coherent structures greatly influence the operation and efficiency of many important commercial and defense technologies. Large scale coherent structures have been studied here in a research program that combines a synergistic blend of experiment, direct numerical simulation, and analysis. This report summarizes the work completed for this Sandia Laboratory-Directed Research and Development (LDRD) project.

  20. Piezoelectric shear wave resonator and method of making same

    DOE Patents [OSTI]

    Wang, J.S.; Lakin, K.M.; Landin, A.R.

    1985-05-20T23:59:59.000Z

    An acoustic shear wave resonator comprising a piezoelectric film having its C-axis substantially inclined from the film normal such that the shear wave coupling coefficient significantly exceeds the longitudinal wave coupling coefficient, whereby the film is capable of shear wave resonance, and means for exciting said film to resonate. The film is prepared by deposition in a dc planar magnetron sputtering system to which a supplemental electric field is applied. The resonator structure may also include a semiconductor material having a positive temperature coefficient of resonance such that the resonator has a temperature coefficient of resonance approaching 0 ppM//sup 0/C.

  1. GAISUS-1 thermionic converter for the integrated solar upper stage

    SciTech Connect (OSTI)

    Begg, L.L.; Heffernan, T.F.; Horner, M.H. [General Atomics, San Diego, CA (United States)

    1997-12-31T23:59:59.000Z

    The Integrated Solar Upper Stage (ISUS) system is a compact orbital transfer vehicle which generates thrust to boost payloads from LEO to higher orbits. It does this by collecting and concentrating solar flux into a sensible thermal storage, graphite receiver which is used to heat hydrogen propellant to temperatures of up to 2500 K. The ISUS receiver also radiates heat into an array of thermionic converters which produce electrical power. The GAISUS-1 thermionic converter is a first generation planar converter designed to produce electrical power when coupled with the ISUS receiver. GAISUS-1 will deliver over 31 W{sub e} at 1900 K. A wrought Re hotshoe accepts radiant heat from the receiver. The back side of the hotshoe forms the emitting surface of the converter. Special attention was paid to optimize the electrical and thermal losses experienced through the sleeve. Triple and single sleeve geometries were thermally modeled and evaluated, resulting in the selection of a single sleeve design. A high temperature metal/ceramic seal isolates the emitter sleeve from the collector. A Nb collector is used and is an integral part of a Nb/Na heat pipe. The heat pipe transports reject heat from the collector surface to a thermal radiator (condenser) portion of the heat pipe. The converter utilizes an integral graphite Cs reservoir. This type of reservoir automatically produces a rise in Cs pressure in response to a rise in emitter/collector temperatures. This Cs pressure feedback mechanism insures adequate Cs coverage of the emitter over a broad range of operating conditions (temperatures).

  2. Symmetry related dynamics in parallel shear flows

    E-Print Network [OSTI]

    Tobias Kreilos; Stefan Zammert; Bruno Eckhardt

    2014-04-23T23:59:59.000Z

    Parallel shear flows come with continuous symmetries of translation in the downstream and spanwise direction. As a consequence, flow states that differ in their spanwise or downstream location but are otherwise identical are dynamically equivalent. In the case of travelling waves, this trivial degree of freedom can be removed by going to a frame of reference that moves with the state, thereby turning the travelling wave in the laboratory frame to a fixed point in the comoving frame of reference. We here discuss a general method by which the translational displacements can be removed also for more complicated and dynamically active states and demonstrate its application for several examples. For flows states in the asymptotic suction boundary layer we show that in the case of the long-period oscillatory edge state we can find local phase speeds which remove the fast oscillations and reveal the slow vortex dynamics underlying the burst phenomenon. For spanwise translating states we show that the method removes the drift but not the dynamical events that cause the big spanwise displacement. For a turbulent case we apply the method to the spanwise shifts and find slow components that are correlated over very long times. Calculations for plane Poiseuille flow show that the long correlations in the transverse motions are not special to the asymptotic suction boundary layer.

  3. Wind turbines convert the kinetic energy in moving air into rotational energy, which in turn is converted

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Wind turbines convert the kinetic energy in moving air into rotational energy, which in turn of electricity wind can make varies constantly. Sometimes a wind turbine will make no power at all is an indicator of how much energy a particular wind turbine makes in a particular place. Continued on page 2 #12

  4. Estimating A Shear Modulus Of A Transversely Isotropic Formation

    E-Print Network [OSTI]

    Ellefsen, K. J.

    1990-01-01T23:59:59.000Z

    A method to estimate c[subscript 66], which is a shear modulus of a transversely isotropic formation (with its symmetry axis parallel to the borehole), is developed and tested. The inversion for c[subscript 66] is based ...

  5. Active, polymer-based composite material implementing simple shear

    E-Print Network [OSTI]

    Lee, Sang Jin

    2009-05-15T23:59:59.000Z

    A novel active material for controllable, high work density applications was designed, fabricated, analyzed, and tested. This active material uses a lens-shaped element to implement simple shear motion with gas pressure actuation. The lens element...

  6. Reflection and Exclusion of Shear Zones in Inhomogeneous Granular Materials

    E-Print Network [OSTI]

    Tamas Borzsonyi; Tamas Unger; Balazs Szabo; Sandra Wegner; Frank Angenstein; Ralf Stannarius

    2011-08-17T23:59:59.000Z

    Shear localization in granular materials is studied experimentally and numerically. The system consists of two material layers with different effective frictions. The presence of the material interface leads to a special type of "total internal reflection" of the shear zone. In a wide range of configurations the reflection is characterized by a fixed angle which is analogous to the critical angle of refraction in optics. The zone leaves and reenters the high friction region at this critical angle and in between it stays near the interface in the low friction region. The formalism describing the geometry of the shear zones and that of refracted and reflected light beams is very similar. For the internal visualization of shear localization two independent experimental techniques were used (i) excavation and (ii) Magnetic Resonance Imaging.

  7. Glycocalyx acting as a mechanotransducer of fluid shear stress

    E-Print Network [OSTI]

    Yao, Yu, Ph. D. Massachusetts Institute of Technology

    2005-01-01T23:59:59.000Z

    It is widely recognized that fluid shearing forces acting on endothelial cells (ECs) have a profound effect on EC morphology, structure and function. Recent investigations in vivo have indicated the presence of a thick ...

  8. Wind Shear Characteristics at Central Plains Tall Towers: Preprint

    SciTech Connect (OSTI)

    Schwartz, M.; Elliott, D.

    2006-06-01T23:59:59.000Z

    Conference paper for WindPower 2006 held June 4-7, 2006, in Pittsburgh, PA, describing the wind shear characteristics at tall tower sites in the Central Plains of the United States.

  9. Landfill liner interface strengths from torsional-ring-shear tests

    SciTech Connect (OSTI)

    Stark, T.D. (Univ. of Illinois, Urbana, IL (United States)); Poeppel, A.R. (Langan Engineering Associates, Inc., New York, NY (United States))

    1994-03-01T23:59:59.000Z

    A torsional-ring-shear apparatus and test procedure are described for measuring soil/geosynthetic and geosynthetic/geosynthetic interface strengths. Typical interface strengths are presented for a double-composite liner system and the relevancy of ring-shear strengths is illustrated using the slope failure at the Kettleman Hills Waste Repository, Kettleman City, Calif. The results of undrained ring-shear tests show that for a clay/geomembrane interface: (1) interface strength depends on plasticity and compaction water content of the clay, and the applied normal stress; (2) interface strengths measured with the torsional-ring-shear apparatus are in excellent agreement with back-calculated field strengths; and (3) peak and residual interface failure envelopes are nonlinear, and the nonlinearity should be modeled in stability analyses instead of as a combination of cohesion and friction angle. Design recommendations for interface strengths and stability analyses are also presented.

  10. Numerical method for shear bands in ductile metal with inclusions

    SciTech Connect (OSTI)

    Plohr, Jee Yeon N [Los Alamos National Laboratory; Plohr, Bradley J [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    A numerical method for mesoscale simulation of high strain-rate loading of ductile metal containing inclusions is described. Because of small-scale inhomogeneities, such a composite material is prone to localized shear deformation (adiabatic shear bands). The modeling framework is the Generalized Method of Cells of Paley and Aboudi [Mech. Materials, vol. 14, pp. /27-139, 1992], which ensures that the micromechanical response of the material is reflected in the behavior of the composite at the mesoscale. To calculate the effective plastic strain rate when shear bands are present, the analytic and numerical analysis of shear bands by Glimm, Plohr, and Sharp [Mech. Materials, vol. 24, pp. 31-41, 1996] is adapted and extended.

  11. Shear measurements across the northern margin of Whillans Ice Stream

    E-Print Network [OSTI]

    Van Der Veen, C.J.; Jezek, K.; Stearns, Leigh

    2007-01-01T23:59:59.000Z

    Field measurements of surface deformation across the northern shear margin of Whillans Ice Stream, West Antarctica, were analyzed to better understand the processes controlling the position and migration of this margin. Four lines of poles extending...

  12. Parallel-Flow-Shear Driven Low-Frequency Plasma Instability

    SciTech Connect (OSTI)

    Ishiguro, Seiji [Theory and Computer Simulation Center, National Institute for Fusion Science, Toki-shi, Gifu 509-5292 (Japan); Matsumoto, Noriaki; Kaneko, Toshiro; Hatakeyama, Rikizo [Department of Electronic Engineering, Tohoku University, Sendai 980-8579 (Japan)

    2004-12-01T23:59:59.000Z

    Full three dimensional Particle-in-Cell (PIC) simulations are performed in order to investigate effects of field-aligned (parallel) ion flow shears on low-frequency plasma instabilities. It is shown that the parallel ion flow velocity shear can induce the ion-acoustic instability, even when the ion flow velocity is so small that the instability can not take place. Simulation results are consistent with the analysis based on the local theory.

  13. Multiplicity of low-shear toroidal Alfven eigenmodes

    SciTech Connect (OSTI)

    Candy, J. [JET Joint Undertaking, Abingdon (United Kingdom); Breizman, B.N. [Univ. of Texas, Austin (United States). Inst. for Fusion Studies]|[Budker Inst. of Nuclear Physics, Novosibirsk (Russian Federation); Van Dam, J.W. [Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies; Ozeki, T. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1996-01-01T23:59:59.000Z

    An enlarged spectrum of ideal toroidal Alfven eigenmodes is demonstrated to exist within a toroidicity-induced Alfven gap when the inverse aspect ratio is comparable to or larger than the value of the magnetic shear. This limit is appropriate for the low-shear region in most tokamaks, especially those with low aspect ratio. The new modes may be destabilized by fusion-product alpha particles more easily than the standard toroidal Alfven eigenmodes.

  14. Isotropic singularities in shear-free perfect fluid cosmologies

    E-Print Network [OSTI]

    Geoffery Ericksson; Susan M. Scott

    2001-08-02T23:59:59.000Z

    We investigate barotropic perfect fluid cosmologies which admit an isotropic singularity. From the General Vorticity Result of Scott, it is known that these cosmologies must be irrotational. In this paper we prove, using two different methods, that if we make the additional assumption that the perfect fluid is shear-free, then the fluid flow must be geodesic. This then implies that the only shear-free, barotropic, perfect fluid cosmologies which admit an isotropic singularity are the FRW models.

  15. Transport bifurcation induced by sheared toroidal flow in tokamak plasmas

    SciTech Connect (OSTI)

    Highcock, E. G.; Barnes, M. [Rudolph Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Parra, F. I.; Schekochihin, A. A. [Rudolph Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Roach, C. M.; Cowley, S. C. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2011-10-15T23:59:59.000Z

    First-principles numerical simulations are used to describe a transport bifurcation in a differentially rotating tokamak plasma. Such a bifurcation is more probable in a region of zero magnetic shear than one of finite magnetic shear, because in the former case the component of the sheared toroidal flow that is perpendicular to the magnetic field has the strongest suppressing effect on the turbulence. In the zero-magnetic-shear regime, there are no growing linear eigenmodes at any finite value of flow shear. However, subcritical turbulence can be sustained, owing to the existence of modes, driven by the ion temperature gradient and the parallel velocity gradient, which grow transiently. Nonetheless, in a parameter space containing a wide range of temperature gradients and velocity shears, there is a sizeable window where all turbulence is suppressed. Combined with the relatively low transport of momentum by collisional (neoclassical) mechanisms, this produces the conditions for a bifurcation from low to high temperature and velocity gradients. A parametric model is constructed which accurately describes the combined effect of the temperature gradient and the flow gradient over a wide range of their values. Using this parametric model, it is shown that in the reduced-transport state, heat is transported almost neoclassically, while momentum transport is dominated by subcritical parallel-velocity-gradient-driven turbulence. It is further shown that for any given input of torque, there is an optimum input of heat which maximises the temperature gradient. The parametric model describes both the behaviour of the subcritical turbulence (which cannot be modelled by the quasi-linear methods used in current transport codes) and the complicated effect of the flow shear on the transport stiffness. It may prove useful for transport modelling of tokamaks with sheared flows.

  16. The Stability of a Shearing Viscous Star with Electromagnetic Field

    E-Print Network [OSTI]

    M. Sharif; M. Azam

    2013-12-04T23:59:59.000Z

    We analyze the role of electromagnetic field for the stability of shearing viscous star with spherical symmetry. Matching conditions are given for the interior and exterior metrics. We use perturbation scheme to construct the collapse equation. The range of instability is explored in Newtonian and post Newtonian (pN) limits. We conclude that the electromagnetic field diminishes the effects of shearing viscosity in the instability range and makes the system more unstable at both Newtonian and post Newtonian approximations.

  17. How does a thermal binary crystal break under shear?

    E-Print Network [OSTI]

    Tobias Horn; Hartmut Löwen

    2014-11-21T23:59:59.000Z

    When exposed to strong shearing, the particles in a crystal will rearrange and ultimately, the crystal will break by forming large nonaffine defects. Even for the initial stage of this process, only little effort has been devoted to the understanding of the breaking process on the scale of the individual particle size for thermalized mixed crystals. Here, we explore the shear-induced breaking for an equimolar two-dimensional binary model crystal with a high interaction asymmetry between the two different species such that the initial crystal has an intersecting square sublattice of the two constituents. Using Brownian dynamics computer simulations, we show that the combination of shear and thermal fluctuations leads to a characteristic hierarchical breaking scenario where initially, the more strongly coupled particles are thermally distorted, paving the way for the weakly coupled particles to escape from their cage. This in turn leads to mobile defects which may finally merge, proliferating a cascade of defects, which triggers the final breakage of the crystal. This scenario is in marked contrast to the breakage of one-component crystals close to melting. Moreover, we explore the orientational dependence of the initial shear direction relative to the crystal orientation and compare this to the usual melting scenario without shear. Our results are verifiable in real-space experiments of superparamagnetic colloidal mixtures at a pending air-water interface in an external magnetic field where the shear can be induced by an external laser field.

  18. Nonlinear physics of shear Alfvén waves

    SciTech Connect (OSTI)

    Zonca, Fulvio [Associazione EURATOM-ENEA sulla Fusione, C.P. 65-00044 Frascati, Italy and Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 31007 (China); Chen, Liu [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 31007, P.R.C. and Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)

    2014-02-12T23:59:59.000Z

    Shear Alfvén waves (SAW) play fundamental roles in thermonuclear plasmas of fusion interest, since they are readily excited by energetic particles in the MeV range as well as by the thermal plasma components. Thus, understanding fluctuation induced transport in burning plasmas requires understanding nonlinear SAW physics. There exist two possible routes to nonlinear SAW physics: (i) wave-wave interactions and the resultant spectral energy transfer; (ii) nonlinear wave-particle interactions of SAW instabilities with energetic particles. Within the first route, it is advantageous to understand and describe nonlinear processes in term of proximity of the system to the Alfvénic state, where wave-wave interactions are minimized due to the cancellation of Reynolds and Maxwell stresses. Here, various wave-wave nonlinear dynamics are elucidated in terms of how they break the Alfvénic state. In particular, we discuss the qualitative and quantitative modification of the SAW parametric decay process due to finite ion compressibility and finite ion Larmor radius. We also show that toroidal geometry plays a crucial role in the nonlinear excitation of zonal structures by Alfvén eigenmodes. Within the second route, the coherent nonlinear dynamics of structures in the energetic particle phase space, by which secular resonant particle transport can occur on meso- and macro-scales, must be addressed and understood. These 'nonlinear equilibria' or 'phase-space zonal structures' dynamically evolve on characteristic (fluctuation induced) turbulent transport time scales, which are generally of the same order of the nonlinear time scale of the underlying fluctuations. In this work, we introduce the general structure of nonlinear Schrödinger equations with complex integro-differential nonlinear terms, which govern these physical processes. To elucidate all these aspects, theoretical analyses are presented together with numerical simulation results.

  19. Permeability characterization of shear zones in the Hickory sandstone member, Riley Formation, Texas

    E-Print Network [OSTI]

    Nieto Camargo, Jorge Enrique

    2005-02-17T23:59:59.000Z

    . The main objectives of this work are to (1) characterize the geometry and permeability of deformation elements within shear zones; (2) determine permeability anisotropy in shear zones according to fault characteristics and host lithology; and (3) develop... I INTRODUCTION .............................................................................................1 II HICKORY SHEAR ZONES AND DEFORMATION ELEMENTS..............11 2.1 Shear Zones in Hickory Sandstone Member...

  20. Technical Paper by T.D. Stark and H.T. Eid SHEAR BEHAVIOR OF REINFORCED

    E-Print Network [OSTI]

    Technical Paper by T.D. Stark and H.T. Eid SHEAR BEHAVIOR OF REINFORCED GEOSYNTHETIC CLAY LINERS strength between a geomembrane and a reinforced geosynthetic clay liner (GeL), and the internal shear: Geosynthetic clay liner, Strength, Stability, Slope, Shearbox test, Shear rate, Ring shear test. AUTHORS: T

  1. Discharging a DC bus capacitor of an electrical converter system

    DOE Patents [OSTI]

    Kajouke, Lateef A; Perisic, Milun; Ransom, Ray M

    2014-10-14T23:59:59.000Z

    A system and method of discharging a bus capacitor of a bidirectional matrix converter of a vehicle are presented here. The method begins by electrically shorting the AC interface of the converter after an AC energy source is disconnected from the AC interface. The method continues by arranging a plurality of switching elements of a second energy conversion module into a discharge configuration to establish an electrical current path from a first terminal of an isolation module, through an inductive element, and to a second terminal of the isolation module. The method also modulates a plurality of switching elements of a first energy conversion module, while maintaining the discharge configuration of the second energy conversion module, to at least partially discharge a DC bus capacitor.

  2. Low work function material development for the microminiature thermionic converter.

    SciTech Connect (OSTI)

    Zavadil, Kevin Robert; Battaile, Corbett Chandler; Marshall, Albert Christian; King, Donald Bryan; Jennison, Dwight Richard

    2004-03-01T23:59:59.000Z

    Thermionic energy conversion in a miniature format shows potential as a viable, high efficiency, micro to macro-scale power source. A microminiature thermionic converter (MTC) with inter-electrode spacings on the order of microns has been prototyped and evaluated at Sandia. The remaining enabling technology is the development of low work function materials and processes that can be integrated into these converters to increase power production at modest temperatures (800 - 1300 K). The electrode materials are not well understood and the electrode thermionic properties are highly sensitive to manufacturing processes. Advanced theoretical, modeling, and fabrication capabilities are required to achieve optimum performance for MTC diodes. This report describes the modeling and fabrication efforts performed to develop micro dispenser cathodes for use in the MTC.

  3. Planar LTCC transformers for high voltage flyback converters: Part II.

    SciTech Connect (OSTI)

    Schofield, Daryl (NASCENTechnology, Inc., Watertown, SD); Schare, Joshua M., Ph.D.; Slama, George (NASCENTechnology, Inc., Watertown, SD); Abel, David (NASCENTechnology, Inc., Watertown, SD)

    2009-02-01T23:59:59.000Z

    This paper is a continuation of the work presented in SAND2007-2591 'Planar LTCC Transformers for High Voltage Flyback Converters'. The designs in that SAND report were all based on a ferrite tape/dielectric paste system originally developed by NASCENTechnoloy, Inc, who collaborated in the design and manufacturing of the planar LTCC flyback converters. The output/volume requirements were targeted to DoD application for hard target/mini fuzing at around 1500 V for reasonable primary peak currents. High voltages could be obtained but with considerable higher current. Work had begun on higher voltage systems and is where this report begins. Limits in material properties and processing capabilities show that the state-of-the-art has limited our practical output voltage from such a small part volume. In other words, the technology is currently limited within the allowable funding and interest.

  4. Ultrafast transient grating radiation to optical image converter

    DOE Patents [OSTI]

    Stewart, Richard E; Vernon, Stephen P; Steel, Paul T; Lowry, Mark E

    2014-11-04T23:59:59.000Z

    A high sensitivity transient grating ultrafast radiation to optical image converter is based on a fixed transmission grating adjacent to a semiconductor substrate. X-rays or optical radiation passing through the fixed transmission grating is thereby modulated and produces a small periodic variation of refractive index or transient grating in the semiconductor through carrier induced refractive index shifts. An optical or infrared probe beam tuned just below the semiconductor band gap is reflected off a high reflectivity mirror on the semiconductor so that it double passes therethrough and interacts with the radiation induced phase grating therein. A small portion of the optical beam is diffracted out of the probe beam by the radiation induced transient grating to become the converted signal that is imaged onto a detector.

  5. Development, evaluation, and design applications of an AMTEC converter model

    E-Print Network [OSTI]

    Spence, Cliff Alan

    2002-01-01T23:59:59.000Z

    of performance curves . . . . . . . 90 INTRODUCTION In the recent history of space exploration, space vehicles slated for missions that ventured into deep space, far from the sun, typically relied on Radioisotope Thermoelectric Generator (RTG) power sources... this need is a type of generator that uses technology known as alkali metal thermal-to-electric conversion (AMTEC). This device, like previous thermoelectric power systems, converts thermal energy directly to electricity. Developed at Ford Scientific...

  6. Intensive neutrino source on the base of lithium converter

    E-Print Network [OSTI]

    V. I. Lyashuk; Yu. S Lutostansky

    2015-03-04T23:59:59.000Z

    An intensive antineutrino source with a hard spectrum (with energy up to 13 MeV, average energy 6.5 MeV) can be realized on the base of beta-decay of short living isotope 8Li (0.84 s). The 8Li isotope (generated in activation of 7Li isotope) is a prime perspective antineutrino source owing to the hard antineutrino spectrum and square dependence of cross section on the energy. Up today nuclear reactors are the most intensive neutrino sources. Antineutrino reactor spectra have large uncertainties in the summary antineutrino spectrum at energy E>6 MeV. Use of 8Li isotope allows to decrease sharply the uncertainties or to exclude it completely. An intensive neutron fluxes are requested for rapid generation of 8Li isotope. The installations on the base of nuclear reactors can be an alternative for nuclear reactors as traditional neutron sources. It is possible creation of neutrino sources another in principle: on the base of tandem of accelerators, neutron generating targets and lithium converter. An intensive neutron flux (i.e., powerful neutron source) is requested for realization of considered neutrino sources (neutrino factories). Different realizations of lithium antineutrino sources (lithium converter on the base of high purified 7Li isotope) are discussed: static regime (i.e., without transport of 8Li isotope to the neutrino detector); dynamic regime (transport of 8Li isotope to the remote detector in a closed cycle); an operation of lithium converter in tandem of accelerator with a neutron-producing target on the base of tungsten, lead or bismuth. Different chemical compounds of lithium (as the substance of the converter) are considered. Heavy water solution of LiOD is proposed as a serious alternative to high-pure 7Li in a metallic state.

  7. Intensive neutrino source on the base of lithium converter

    E-Print Network [OSTI]

    V. I. Lyashuk; Yu. S Lutostansky

    2015-04-13T23:59:59.000Z

    An intensive antineutrino source with a hard spectrum (with energy up to 13 MeV, average energy 6.5 MeV) can be realized on the base of beta-decay of short living isotope 8Li (0.84 s). The 8Li isotope (generated in activation of 7Li isotope) is a prime perspective antineutrino source owing to the hard antineutrino spectrum and square dependence of cross section on the energy. Up today nuclear reactors are the most intensive neutrino sources. Antineutrino reactor spectra have large uncertainties in the summary antineutrino spectrum at energy E>6 MeV. Use of 8Li isotope allows to decrease sharply the uncertainties or to exclude it completely. An intensive neutron fluxes are requested for rapid generation of 8Li isotope. The installations on the base of nuclear reactors can be an alternative for nuclear reactors as traditional neutron sources. It is possible creation of neutrino sources another in principle: on the base of tandem of accelerators, neutron generating targets and lithium converter. An intensive neutron flux (i.e., powerful neutron source) is requested for realization of considered neutrino sources (neutrino factories). Different realizations of lithium antineutrino sources (lithium converter on the base of high purified 7Li isotope) are discussed: static regime (i.e., without transport of 8Li isotope to the neutrino detector); dynamic regime (transport of 8Li isotope to the remote detector in a closed cycle); an operation of lithium converter in tandem of accelerator with a neutron-producing target on the base of tungsten, lead or bismuth. Different chemical compounds of lithium (as the substance of the converter) are considered. Heavy water solution of LiOD is proposed as a serious alternative to high-pure 7Li in a metallic state.

  8. Catalyst for converting synthesis gas to liquid motor fuels

    DOE Patents [OSTI]

    Coughlin, Peter K. (Yorktown Heights, NY)

    1986-01-01T23:59:59.000Z

    The addition of an inert metal component, such as gold, silver or copper, to a Fischer-Tropsch catalyst comprising cobalt enables said catalyst to convert synthesis gas to liquid motor fuels at about 240.degree.-370.degree. C. with advantageously reduced selectivity of said cobalt for methane in said conversion. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

  9. Low current plasmatron fuel converter having enlarged volume discharges

    DOE Patents [OSTI]

    Rabinovich, Alexander (Swampscott, MA); Alexeev, Nikolai (Moscow, RU); Bromberg, Leslie (Sharon, MA); Cohn, Daniel R. (Chestnut Hill, MA); Samokhin, Andrei (Moscow, RU)

    2009-10-06T23:59:59.000Z

    A novel apparatus and method is disclosed for a plasmatron fuel converter ("plasmatron") that efficiently uses electrical energy to produce hydrogen rich gas. The volume and shape of the plasma discharge is controlled by a fluid flow established in a plasma discharge volume. A plasmatron according to this invention produces a substantially large effective plasma discharge volume allowing for substantially greater volumetric efficiency in the initiation of chemical reactions within a volume of bulk fluid reactant flowing through the plasmatron.

  10. Capacitor-Less VAR Compensator Based on a Matrix Converter

    E-Print Network [OSTI]

    Balakrishnan, Divya Rathna

    2012-02-14T23:59:59.000Z

    greatly contributed to the completion of this work. I owe my gratitude to them for always believing in me and helping me through my academic pursuit. vii NOMENCLATURE VAR Volt-ampere reactive MC 3-phase ac-to-3-phase ac matrix converter v1... [10] ...... 12 10 Equivalent circuit of a capacitor................................................................. 13 11 Basic layout of a 3/3 MC............................................................................ 16 12 Block diagram...

  11. Microsoft PowerPoint - Converting Sustainable Forest Products into Fuel

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department of EnergyDevelopmentTechnologiesfromScienceSeptember 15, 2008.Converting

  12. Fractal nature of multiple shear bands in severely deformed metallic glass

    SciTech Connect (OSTI)

    Sun, B. A.; Wang, W. H. [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2011-05-16T23:59:59.000Z

    We present an analysis of fractal geometry of extensive and complex shear band patterns in a severely deformed metallic glass. We show that the shear band patterns have fractal characteristics, and the fractal dimensions are determined by the stress noise induced by the interaction between shear bands. A theoretical model of the spatial evolution of multiple shear bands is proposed in which the collective shear bands slide is considered as a stochastic process far from thermodynamic equilibrium.

  13. Shear Connections for the Development of a Full-Depth Precast Concrete Deck System

    E-Print Network [OSTI]

    Henley, Matthew D.

    2010-07-14T23:59:59.000Z

    American Institute of Steel Construction BC Bolt with coupler shear connection CCD Concrete capacity design CIP Cast-in-place KB Kwik-bolt mechanical anchor shear connection LRFD Load and resistance factor design LVDT Linear variable differential... transducer NCHRP National Cooperative Highway Research Program NS Nelson stud R R-bar shear connection within a pocket system SIP Stay-in-place TR Threaded rod shear connection TRC Threaded rod with coupler shear connection TRE Threaded rod post...

  14. Five-Year Outcomes, Cosmesis, and Toxicity With 3-Dimensional Conformal External Beam Radiation Therapy to Deliver Accelerated Partial Breast Irradiation

    SciTech Connect (OSTI)

    Rodríguez, Núria, E-mail: nrodriguez@parcdesalutmar.cat [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Sanz, Xavier [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Dengra, Josefa [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Foro, Palmira [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Membrive, Ismael; Reig, Anna [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Quera, Jaume [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Fernández-Velilla, Enric; Pera, Óscar; Lio, Jackson; Lozano, Joan [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Algara, Manuel [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain)

    2013-12-01T23:59:59.000Z

    Purpose: To report the interim results from a study comparing the efficacy, toxicity, and cosmesis of breast-conserving treatment with accelerated partial breast irradiation (APBI) or whole breast irradiation (WBI) using 3-dimensional conformal external beam radiation therapy (3D-CRT). Methods and Materials: 102 patients with early-stage breast cancer who underwent breast-conserving surgery were randomized to receive either WBI (n=51) or APBI (n=51). In the WBI arm, 48 Gy was delivered to the whole breast in daily fractions of 2 Gy, with or without additional 10 Gy to the tumor bed. In the APBI arm, patients received 37.5 Gy in 3.75 Gy per fraction delivered twice daily. Toxicity results were scored according to the Radiation Therapy Oncology Group Common Toxicity Criteria. Skin elasticity was measured using a dedicated device (Multi-Skin-Test-Center MC-750-B2, CKelectronic-GmbH). Cosmetic results were assessed by the physician and the patients as good/excellent, regular, or poor. Results: The median follow-up time was 5 years. No local recurrences were observed. No significant differences in survival rates were found. APBI reduced acute side effects and radiation doses to healthy tissues compared with WBI (P<.01). Late skin toxicity was no worse than grade 2 in either group, without significant differences between the 2 groups. In the ipsilateral breast, the areas that received the highest doses (ie, the boost or quadrant) showed the greatest loss of elasticity. WBI resulted in a greater loss of elasticity in the high-dose area compared with APBI (P<.05). Physician assessment showed that >75% of patients in the APBI arm had excellent or good cosmesis, and these outcomes appear to be stable over time. The percentage of patients with excellent/good cosmetic results was similar in both groups. Conclusions: APBI delivered by 3D-CRT to the tumor bed for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with conventional WBI.

  15. The Effect of Dose-Volume Parameters and Interfraction Interval on Cosmetic Outcome and Toxicity After 3-Dimensional Conformal Accelerated Partial Breast Irradiation

    SciTech Connect (OSTI)

    Leonard, Kara Lynne, E-mail: karalynne.kerr@gmail.com [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States); Hepel, Jaroslaw T. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States) [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States); Department of Radiation Oncology, Rhode Island Hospital, Warren Alpert School of Medicine of Brown University, Providence, Rhode Island (United States); Hiatt, Jessica R. [Department of Radiation Oncology, Rhode Island Hospital, Warren Alpert School of Medicine of Brown University, Providence, Rhode Island (United States)] [Department of Radiation Oncology, Rhode Island Hospital, Warren Alpert School of Medicine of Brown University, Providence, Rhode Island (United States); Dipetrillo, Thomas A. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States) [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States); Department of Radiation Oncology, Rhode Island Hospital, Warren Alpert School of Medicine of Brown University, Providence, Rhode Island (United States); Price, Lori Lyn [Department of Biostatistics Research Center, Institute of Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, Massachusetts (United States)] [Department of Biostatistics Research Center, Institute of Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, Massachusetts (United States); Wazer, David E. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States) [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States); Department of Radiation Oncology, Rhode Island Hospital, Warren Alpert School of Medicine of Brown University, Providence, Rhode Island (United States)

    2013-03-01T23:59:59.000Z

    Purpose: To evaluate dose-volume parameters and the interfraction interval (IFI) as they relate to cosmetic outcome and normal tissue effects of 3-dimensional conformal radiation therapy (3D-CRT) for accelerated partial breast irradiation (APBI). Methods and Materials: Eighty patients were treated by the use of 3D-CRT to deliver APBI at our institutions from 2003-2010 in strict accordance with the specified dose-volume constraints outlined in the National Surgical Adjuvant Breast and Bowel Project B39/Radiation Therapy Oncology Group 0413 (NSABP-B39/RTOG 0413) protocol. The prescribed dose was 38.5 Gy in 10 fractions delivered twice daily. Patients underwent follow-up with assessment for recurrence, late toxicity, and overall cosmetic outcome. Tests for association between toxicity endpoints and dosimetric parameters were performed with the chi-square test. Univariate logistic regression was used to evaluate the association of interfraction interval (IFI) with these outcomes. Results: At a median follow-up time of 32 months, grade 2-4 and grade 3-4 subcutaneous fibrosis occurred in 31% and 7.5% of patients, respectively. Subcutaneous fibrosis improved in 5 patients (6%) with extended follow-up. Fat necrosis developed in 11% of women, and cosmetic outcome was fair/poor in 19%. The relative volume of breast tissue receiving 5%, 20%, 50%, 80%, and 100% (V5-V100) of the prescribed dose was associated with risk of subcutaneous fibrosis, and the volume receiving 50%, 80%, and 100% (V50-V100) was associated with fair/poor cosmesis. The mean IFI was 6.9 hours, and the minimum IFI was 6.2 hours. The mean and minimum IFI values were not significantly associated with late toxicity. Conclusions: The incidence of moderate to severe late toxicity, particularly subcutaneous fibrosis and fat necrosis and resulting fair/poor cosmesis, remains high with continued follow-up. These toxicity endpoints are associated with several dose-volume parameters. Minimum and mean IFI values were not associated with late toxicity.

  16. Potential for Improved Intelligence Quotient Using Volumetric Modulated Arc Therapy Compared With Conventional 3-Dimensional Conformal Radiation for Whole-Ventricular Radiation in Children

    SciTech Connect (OSTI)

    Qi, X. Sharon, E-mail: xqi@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California (United States); Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Stinauer, Michelle; Rogers, Brion [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)] [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Madden, Jennifer R. [Department of Neuro-Oncology, The Children's Hospital, Aurora, Colorado (United States)] [Department of Neuro-Oncology, The Children's Hospital, Aurora, Colorado (United States); Wilkening, Greta N. [Department of Pediatrics, The Children's Hospital, Aurora, Colorado (United States)] [Department of Pediatrics, The Children's Hospital, Aurora, Colorado (United States); Liu, Arthur K. [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)] [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)

    2012-12-01T23:59:59.000Z

    Purpose: To compare volumetric modulated arc therapy (VMAT) with 3-dimensional conformal radiation therapy (3D-CRT) in the treatment of localized intracranial germinoma. We modeled the effect of the dosimetric differences on intelligence quotient (IQ). Method and Materials: Ten children with intracranial germinomas were used for planning. The prescription doses were 23.4 Gy to the ventricles followed by 21.6 Gy to the tumor located in the pineal region. For each child, a 3D-CRT and full arc VMAT was generated. Coverage of the target was assessed by computing a conformity index and heterogeneity index. We also generated VMAT plans with explicit temporal lobe sparing and with smaller ventricular margin expansions. Mean dose to the temporal lobe was used to estimate IQ 5 years after completion of radiation, using a patient age of 10 years. Results: Compared with the 3D-CRT plan, VMAT improved conformality (conformity index 1.10 vs 1.85), with slightly higher heterogeneity (heterogeneity index 1.09 vs 1.06). The averaged mean doses for left and right temporal lobes were 31.3 and 31.7 Gy, respectively, for VMAT plans and 37.7 and 37.6 Gy for 3D-CRT plans. This difference in mean temporal lobe dose resulted in an estimated IQ difference of 3.1 points at 5 years after radiation therapy. When the temporal lobes were explicitly included in the VMAT optimization, the mean temporal lobe dose was reduced 5.6-5.7 Gy, resulting in an estimated IQ difference of an additional 3 points. Reducing the ventricular margin from 1.5 cm to 0.5 cm decreased mean temporal lobe dose 11.4-13.1 Gy, corresponding to an estimated increase in IQ of 7 points. Conclusion: For treatment of children with intracranial pure germinomas, VMAT compared with 3D-CRT provides increased conformality and reduces doses to normal tissue. This may result in improvements in IQ in these children.

  17. "Seismic Behavior and Design of Steel Shear Walls", A. Astaneh-Asl, SEAONC Seminar, November 2001, San Francisco. of 181 Seismic Behavior and Design of Steel Shear Walls

    E-Print Network [OSTI]

    Astaneh-Asl, Abolhassan

    "Seismic Behavior and Design of Steel Shear Walls", A. Astaneh-Asl, SEAONC Seminar, November 2001, San Francisco. of 181 Seismic Behavior and Design of Steel Shear Walls By Abolhassan Astaneh-Asl, Ph.ce.berkeley.edu/~astaneh Introduction Steel plate shear wall systems have been used in recent years in highly seismic areas to resist

  18. Computer-aided optimization of DC/DC converters for automotive applications

    E-Print Network [OSTI]

    Neugebauer, Timothy C.

    This paper investigates computer-aided optimization of DC/DC converters, with a focus on converters for dual-voltage automotive electrical systems. A new CAD optimization approach based on Monte Carlo search methods is ...

  19. Blind calibration of timing skew in time-interleaved analog-to-digital converters

    E-Print Network [OSTI]

    Divi, Vijay

    The performance of time-interleaved analog-to-digital converters is often significantly degraded by timing mismatch errors. We develop methods for performing blind calibration of such converters, i.e., for estimating the ...

  20. Reentry aerodynamic disruption analysis of thermionic reactor-thermo-converter TOPAZ-2

    SciTech Connect (OSTI)

    Grinberg, E.I.; Nikolaev, V.S. (Scientific Production Association Krasnaya Zvezda'', Moscow 115230 (Russian Federation)); Usov, V.A. (RRC Kurchatov Institute'', Moscow 123182 (Russian Federation)); Gafarov, A.A. (Research Institute of Thermal Processes, Moscow (Russian Federation))

    1993-01-15T23:59:59.000Z

    This paper presents preliminary results of analysis for the TOPAZ-2 thermionic converter-reactor aerodynamic disruption during reentry.

  1. Comparison between arc drops in ignited thermionic converters with and without ion reflections at the emitter

    SciTech Connect (OSTI)

    Lundgren, L.

    1985-07-01T23:59:59.000Z

    The output performance of two thermionic energy converters is compared. One converter has a normal emitter, working with zero field at the emitter which is close to the optimum working point, and the other has a low work function emitter and ion reflection at the emitter. A simple model of the plasma and the sheaths shows that a converter working with a low work function emitter and ion reflections gives a worse performance than a similar converter with a normal emitter.

  2. Shear Waves, Sound Waves On A Shimmering Horizon

    E-Print Network [OSTI]

    Omid Saremi

    2007-03-19T23:59:59.000Z

    In the context of the so called ``membrane paradigm'' of black holes/branes, it has been known for sometime that the dynamics of small fluctuations on the stretched horizon can be viewed as corresponding to diffusion of a conserved charge in simple fluids. To study shear waves in this context properly, one must define a conserved stress tensor living on the stretched horizon. Then one is required to show that such a stress tensor satisfies the corresponding constitutive relations. These steps are missing in a previous treatment of the shear perturbations by Kovtun, Starinets and Son. In this note, we fill the gap by prescribing the stress tensor on the stretched horizon to be the Brown and York (or Balasubramanian-Kraus (BK) in the AdS/CFT context) holographic stress tensor. We are then able to show that such a conserved stress tensor satisfies the required constitutive relation on the stretched horizon using Einstein equations. We read off the shear viscosity from the constitutive relations in two different channels, shear and sound. We find an expression for the shear viscosity in both channels which are equal, as expected. Our expression is in agreement with a previous membrane paradigm formula reported by Kovtun, Starinets and Son.

  3. Reliability Assessment of Fault-Tolerant Dc-Dc Converters for Photovoltaic Applications

    E-Print Network [OSTI]

    Liberzon, Daniel

    Reliability Assessment of Fault-Tolerant Dc-Dc Converters for Photovoltaic Applications Sairaj V performance and reliability analysis of switch-mode, dc-dc power converters employed as front ends of the converter's steady-state operation on device failure rates. Markov reliability models are derived to assess

  4. Modeling and Analysis of Hybrid Converters Michael Evzelman Shmuel (Sam) Ben-Yaakov

    E-Print Network [OSTI]

    the characteristics of hybrid converters. Renewable energy sources such as a single PV panel have, in general, a lowModeling and Analysis of Hybrid Converters Michael Evzelman Shmuel (Sam) Ben-Yaakov Power.ee.bgu.ac.il/~pel/ Abstract--A generic behavioral average-circuit model that analyzes hybrid converters that include

  5. Hybrid Control of a Three-Cell Converter Associated to an Inductive Load

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    3519 Hybrid Control of a Three-Cell Converter Associated to an Inductive Load M. Trabelsi, J of the proposed method. - Dynamic Hybrid Systems, Multi-cell converter, Hybrid control, Digital Signal Processing a class of Hybrid Dynamic Systems (HDS). In the field of power electronics, static converters associated

  6. CHARACTERIZING DANGEROUS WAVES FOR OCEAN WAVE ENERGY CONVERTER SURVIVABILITY Justin Hovland

    E-Print Network [OSTI]

    Haller, Merrick

    CHARACTERIZING DANGEROUS WAVES FOR OCEAN WAVE ENERGY CONVERTER SURVIVABILITY Justin Hovland ABSTRACT Ocean Wave Energy Converters (OWECs) operating on the water surface are subject to storms gradient technologies. This paper is focused on Ocean Wave Energy Converters (OWECs) and the need

  7. Effects of cyclic loading on internal shear strength of unreinforced geosynthetic clay liner

    SciTech Connect (OSTI)

    Lai, J. [Ghaoyang Univ. of Technology, Taichung (Taiwan, Province of China); Daniel, D.E. [Univ. of Illinois, Urbana, IL (United States). Dept. of Civil Engineering; Wright, S.G. [Univ. of Texas, Austin, TX (United States). Dept. of Civil Engineering

    1998-01-01T23:59:59.000Z

    Stress-controlled static and cyclic shear tests were performed by using a direct simple shear device on samples of a geomembrane-supported geosynthetic clay liner (GCL). The dry material showed no degradation in shear strength during cyclic loading as long as the peak shear stress was less than the static shear strength of the GCL with no cyclic loading. Furthermore, cyclic loading slightly densified the dry bentonite and thus increased its shear resistance under subsequent static loading. On the other hand, the shear strength of the hydrated GCL was found to be reduced by cyclic loading. The number of cycles to cause failure decreased with increasing cyclic stress ratio (cyclic shear stress divided by undrained static shear strength); at a cyclic stress ratio of 0.67, failure occurred at 32 cycles of loading, but at a cyclic stress ratio of 0.53, failure did not occur until up to 200 cycles of loading.

  8. Bi-Directional DC-DC Converter for PHEV Applications

    SciTech Connect (OSTI)

    Abas Goodarzi

    2011-01-31T23:59:59.000Z

    Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for Electric Vehicle (EV) mode range. However, ESS technologies to maximize power density and energy density simultaneously are not commercially feasible. The use of bi-directional DC-DC converter allows use of multiple energy storage, and the flexible DC-link voltages can enhance the system efficiency and reduce component sizing. This will improve fuel consumption, increase the EV mode range, reduce the total weight, reduce battery initial and life cycle cost, and provide flexibility in system design.

  9. Close-spaced Knudsen`s mode thermionic converter

    SciTech Connect (OSTI)

    Kucherov, R.Ya.; Nikolaev, Y.V. [Research Inst. of SIA Lutch, Podolsk (Russian Federation)

    1995-12-31T23:59:59.000Z

    It is demonstrated that the Knudsen`s mode of the thermionic converter (TIC) operation can be realized in a TIC with the interelectrode spacing 15{divided_by}30 {mu} and the emitter work function 5{divided_by}5.5 eV at the emitter temperature above 1800 K and cesium vapor pressure 0.5{divided_by}1 tor. With the use of reflective coating applied to the collector, efficiency of such TIC can achieve the level in excess of 30%.

  10. Results from the Microminiature Thermionic Converter Demonstration Testing Program

    SciTech Connect (OSTI)

    King, D.B.; Luke, J.R.; Wyant, F.J.

    1998-10-05T23:59:59.000Z

    Research is in progress to develop microminiature thermionic converters (MTCS) with high energy conversion efficiencies and variable operating temperatures using semiconductor integrated circuit (IC) fabrication methods. The use of IC techniques allows the fabrication of MTCS with cathode to anode spacing of several microns or less and with anode and cathode materials that will have work fimctions ranging from 1 eV to 3 eV. The small cathode to anode spacing and variable electrode work functions should allow the conversion of heat energy to relatively large current densities (up to tens of Amps/cmz) at relatively high conversion efficiencies ( 15-25%).

  11. Experimental investigation of a thermionic converter with developed surface electrodes

    SciTech Connect (OSTI)

    Luke, J.R.; El-Genk, M.S.; Adrian, J.M. [Institute for Space and Nuclear Power Studies/Chemical and Nuclear Engineering Department University of New Mexico, Albuquerque, New Mexico87131 (United States)

    1997-01-01T23:59:59.000Z

    A thermionic converter with developed planar electrode surfaces is designed and tested. One of the electrodes has concentric circular grooves cut into its surface, while the other electrode surface is smooth. The grooves are 0.5 mm deep and 0.5 mm wide, having lands that are 1.0 mm wide. The experimental setup is flexible so that either the smooth or developed surface electrode can be operated as the emitter, with the other operating as the collector. The I-V characteristics and power output are compared for the two electrode arrangements. {copyright} {ital 1997 American Institute of Physics.}

  12. Multichannel analog-digital converter in VEKTOR-CAMAC systemsystems

    SciTech Connect (OSTI)

    Borodyanskii, M.E.

    1986-09-01T23:59:59.000Z

    This paper describes a four-channel analog-digital converter (ADC) that is implemented by large-scale integrated circuits. Resdundancy of signal conversion in intermediate cycles ensures a more accurate conversion result from cycle to cycle. The ADC is fully compatible with the Vektor system and, with slight modifications, is CAMAC compatible. The conversion time of the ADC for one channel is 5 used, the output code is 14-bit binary, the maximum integral nonlinearity is not more than 0.05% of the dynamic range of + or -10V, and the size of the random access memeory is 1024 14-bit words.

  13. Experimental investigation of a thermionic converter with developed surface electrodes

    SciTech Connect (OSTI)

    Luke, James R.; El-Genk, Mohamed S.; Adrian, John M. [Institute for Space and Nuclear Power Studies/Chemical and Nuclear Engineering Department University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    1997-01-10T23:59:59.000Z

    A thermionic converter with developed planar electrode surfaces is designed and tested. One of the electrodes has concentric circular grooves cut into its surface, while the other electrode surface is smooth. The grooves are 0.5 mm deep and 0.5 mm wide, having lands that are 1.0 mm wide. The experimental setup is flexible so that either the smooth or developed surface electrode can be operated as the emitter, with the other operating as the collector. The I-V characteristics and power output are compared for the two electrode arrangements.

  14. Performance testing of the Sandy Pond HVDC converter terminal

    SciTech Connect (OSTI)

    Donahue, J.A.; Fisher, D.A.; Railing, B.D.; Tatro, P.J. (New England Power Service Co., Westborough, MA (United States))

    1993-01-01T23:59:59.000Z

    Results of several performance tests for the 1,800 MW Sandy Pond HVDC converter terminal are presented and discussed. The work progressed during 1990 and 1991 and included tests for power line carrier interference, audible sound, ac and dc line faults and dc harmonic performance. The testing was conducted as part of the commissioning program for the first stage of the Quebec-New England Phase 2 multi-terminal system. In this stage, the Radisson (Quebec) and Sandy Pond (New England) terminals are operational.

  15. Optimal design of AC filter circuits in HVDC converter stations

    SciTech Connect (OSTI)

    Saied, M.M.; Khader, S.A. [Kuwait Univ. (Kuwait). Electrical and Computer Engineering Dept.

    1995-12-31T23:59:59.000Z

    This paper investigates the reactive power as well as the harmonic conditions on both the valve and the AC-network sides of a HVDC converter station. The effect of the AC filter circuits is accurately modeled. The program is then augmented by adding an optimization routine. It can identify the optimal filter configuration, yielding the minimum current distortion factor at the AC network terminals for a prespecified fundamental reactive power to be provided by the filter. Several parameter studies were also conducted to illustrate the effect of accidental or intentional deletion of one of the filter branches.

  16. Harmonic measurements from a group connected generator HVdc converter scheme

    SciTech Connect (OSTI)

    Macdonald, S.J.; Enright, W.; Arrillaga, J. [Univ. of Canterbury, Christchurch (New Zealand)] [Univ. of Canterbury, Christchurch (New Zealand); O`Brien, M.T.

    1995-10-01T23:59:59.000Z

    A recent CIGRE document published in ELECTRA has described the potential benefits of a direct connection of generators to HVdc converters. While many theoretical contributions have been made, no practical test data has become available so far. This paper reports on harmonic tests carried out at the Benmore end of the New Zealand HVdc link operating as a group connected scheme. It was found that the measured harmonic current levels were well below specified generator ratings. Dynamic simulation accurately predicted the harmonic currents whereas the results of a steady state formulation were less reliable.

  17. MHK Technologies/Tide Current Converter | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IEOWC <SurgeWECSails <Tide Current Converter

  18. Use of a combined lining in copper production converters

    SciTech Connect (OSTI)

    Birkle, G.V.B.; Slovikovski, V.V.; Danilova, T.A.; P'yankova, V.A.; Verzilov, N.A.

    1987-01-01T23:59:59.000Z

    The authors look at materials and methods for increasing the liner life and thermal efficiency of converters used at three copper melting combines in the Soviet Union. The refractories tested are various commercial combinations of magnesite, periclase and chromite, and the properties for which they are tested include their compression strength, heat resistance, thermal expansion, and wear resistance to slag. The authors find the refractory combination least degradable by heat and wear and calculate the savings, both in cost and energy, achieved by the combines in question by the utilization of this liner material.

  19. Converting Methane to Methanol: Structural Insight into the Reaction Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity2Workshops01ControllingControls onPolymers -Converting

  20. Light-weight DC to very high voltage DC converter

    DOE Patents [OSTI]

    Druce, Robert L. (Union City, CA); Kirbie, Hugh C. (Dublin, CA); Newton, Mark A. (Livermore, CA)

    1998-01-01T23:59:59.000Z

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.

  1. Light-weight DC to very high voltage DC converter

    DOE Patents [OSTI]

    Druce, R.L.; Kirbie, H.C.; Newton, M.A.

    1998-06-30T23:59:59.000Z

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

  2. Behavior of plate trunnions subjected to shear loads

    SciTech Connect (OSTI)

    Choo, Y.S.; Padmanaban, K.; Shanmugam, N.E.; Liew, J.Y.R. [National Univ. of Singapore (Singapore). Faculty of Engineering

    1995-12-31T23:59:59.000Z

    The use of fabricated trunnions in heavy lift installation of offshore and marine structures is becoming widespread. This paper presents the results of a parametric study, with systematic variation of relevant geometric parameters, on the elasto-plastic responses of plate trunnions subjected to shear loads from the sling eyes. Two distinctive failure modes, associated with main plate dominated and shear plate/trunnion pipe dominated responses are identified and the corresponding results summarized. A proportional limit load, P{sub yl}, is defined for each specimen based on its load-displacement response. It is observed that a plate trunnion possesses significant reserve strength beyond its limit load and that current industry practice, which considers the shear plate only to transfer the total sling load into the main plate, is overly conservative.

  3. Quasiparticle theory of shear and bulk viscosities of hadronic matter

    SciTech Connect (OSTI)

    Chakraborty, P.; Kapusta, J. I. [School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2011-01-15T23:59:59.000Z

    A theoretical framework for the calculation of shear and bulk viscosities of hadronic matter at finite temperature is presented. The framework is based on the quasiparticle picture. It allows for an arbitrary number of hadron species with pointlike interactions, and allows for both elastic and inelastic collisions. Detailed balance is ensured. The particles have temperature-dependent masses arising from mean-field or potential effects, which maintains self-consistency between the equation of state and the transport coefficients. As an example, we calculate the shear and bulk viscosity in the linear {sigma} model. The ratio of shear viscosity to entropy density shows a minimum in the vicinity of a rapid crossover transition, whereas the ratio of bulk viscosity to entropy density shows a maximum.

  4. Nonlinear FE analysis of cracks in tension and shear

    E-Print Network [OSTI]

    Kesse, G.; Lees, Janet M.

    2007-05-01T23:59:59.000Z

    Carbon FRP Shear Reinforcement. PhD thesis, University of Cambridge, UK, 2003. 3. Bazant Z. P. and Planas J. Fracture and Size Effect in Con- crete and Other Quasibrittle Materials. CRC Press, Boca Raton, Florida, 1998. Nonlinear FE analysis of cracks... of plain concrete to cyclic tension. ACI Materials Journal, 1987, 84, No. 5, 365–373. 9. Paulay T. and Loeber P. J. Shear transfer by aggregate inter- lock. ACI Special Publication, SP-42, 1974, 1, 1–14. 10. Houde J. and Mirza M. S. A finite element...

  5. Shear zone refraction and deflection in layered granular materials

    E-Print Network [OSTI]

    Tamas Borzsonyi; Tamas Unger; Balazs Szabo

    2009-12-09T23:59:59.000Z

    Refraction and deflection of shear zones in layered granular materials was studied experimentally and numerically. We show, that (i) according to a recent theoretical prediction [T. Unger, Phys. Rev. Lett. 98, 018301 (2007)] shear zones refract in layered systems in analogy with light refraction, (ii) zone refraction obeys Snell's law known from geometric optics and (iii) under natural pressure conditions (i.e. in the presence of gravity) the zone can also be deflected by the interface so that the deformation of the high friction material is avoided.

  6. Phenomenological model for ordered onions under shear flow

    E-Print Network [OSTI]

    Kenta Odagiri; Kazue Kudo

    2011-09-02T23:59:59.000Z

    We propose a phenomenological model for the multi-lamellar vesicles (onions) formation induced by shear flow. In a nonionic surfactant (C$_{12}$E$_4$) system, onion phases under a fixed shear flow within a certain range show the order-disorder transition accompanied with a size jump by changing temperature. Our model can simulate ordered and disordered onion phases with different onion sizes. We show numerical results of the onion formation simulated by the model and also discuss what factors in this system are critical to cause the transition between these two different onion phases.

  7. Scaling of the magnetic reconnection rate with symmetric shear flow

    SciTech Connect (OSTI)

    Cassak, P. A. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Otto, A. [Geophysical Institute, University of Alaska-Fairbanks, Fairbanks, Alaska 99775 (United States)

    2011-07-15T23:59:59.000Z

    The scaling of the reconnection rate during (fast) Hall magnetic reconnection in the presence of an oppositely directed bulk shear flow parallel to the reconnecting magnetic field is studied using two-dimensional numerical simulations of Hall reconnection with two different codes. Previous studies noted that the reconnection rate falls with increasing flow speed and shuts off entirely for super-Alfvenic flow, but no quantitative expression for the reconnection rate in sub-Alfvenic shear flows is known. An expression for the scaling of the reconnection rate is presented.

  8. Thermonuclear Fusion with the Sheared Flow Stabilized Z-Pinch

    E-Print Network [OSTI]

    Winterberg, F

    2008-01-01T23:59:59.000Z

    Two basic approaches to producing thermonuclear fusion with a sheared flow stabilized z-pinch are considered. One consists of heating the entire length of the z-pinch column to the required temperatures. The other basic approach considered here involves the concept of fast ignition. A localized "hot-spot" is produced under the proper conditions to ignite a thermonuclear burn wave in the z-pinch plasma. Here we demonstrate that sheared flow stabilization is more efficient in the fast-ignition method with isentropic compression then in a z-pinch where the entire plasma column is heated.

  9. Design and testing of a combustion-heated nineteen-converter SAVTEC array

    SciTech Connect (OSTI)

    Nyren, T.; Fitzpatrick, G.O.; Korringa, M.; McVey, J.; Sahines, T.

    1984-08-01T23:59:59.000Z

    The SAVTEC (Self-Adjusting Versatile Thermionic Energy Converter) is a new design approach for achieving very close (<12..mu..) interelectrode spacing in a thermionic converter. Techniques were developed for fabricating an array of nineteen SAVTEC converters. The array was incorporated in an SiC protective ''hot shell'' which also served as a radiant heat source for the emitter of each converter. The completed assembly was tested with a specially constructed combustion heat source. Electric output was generated by sixteen of the nineteen converters, despite poor thermal contact in a cooling block, which resulted in high collector temperatures. Details of the array design and test results are described.

  10. Analysis of emitter material transport in thermionic converter

    SciTech Connect (OSTI)

    Paramonov, D.V.; El-Genk, M.S. [Institute for Space and Nuclear Power Studies, Chemical and Nuclear Engineering Department, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    1996-03-01T23:59:59.000Z

    Output power and efficiency of a thermionic converter depend on temperatures, cesiated work functions, and emissivities of electrodes as well as the interelectrode gap size. Operation lifetime of a thermionic converter is directly related to the values as well as the stability of these parameters, which can be seriously altered by the transport of emitter material to the collector during operation. Loss rate of tungsten, a preferred emitter material, by sublimation at typical operating temperatures is small (about 3{times}10{sup 7} atom/cm{sup 2}sec at 2000 K). The loss rate, however, can be several orders of magnitude higher in the presence of gaseous contaminants. Accelerated transport of emitter material to collector surface changes the effective emissivity and work functions of the electrodes, resulting in performance degradation. A phenomenological model was developed to simulate emitter material transport to the collector in the presence of oxygen, water vapor, and carbon oxide contaminants. The model accounts for interaction of these contaminants with both emitter and collector. Model results were in agreement with experimental data and theoretical results of other investigators. An analysis was performed to determine steady-state chemical composition of deposited material onto the collector surface in the presence of H{sub 2}O, O{sub 2}, and H{sub 2} gaseous contaminants. {copyright} {ital 1996 American Institute of Physics.}

  11. Thermionic converters for an Integrated Solar Upper Stage (ISUS)

    SciTech Connect (OSTI)

    Anderson, W.G.; Horner-Richardson, K. [Thermacore, Inc., Lancaster, PA (United States)

    1996-12-31T23:59:59.000Z

    The Integrated Solar Upper Stage (ISUS) is a solar bimodal system which combines thermal propulsion and electric power generation in a single integrated system. A thermionic converter was designed and fabricated for the ISUS system. The ISUS thermionic energy converters differ from previous designs, due to the significant changes in operating temperature prior to and during an eclipse, with the emitter temperature increasing from 1,900 K to 2,200 K, and then back again. A complete thermal and electrical model was developed for a planar diode to determine optimum operating dimensions and parameters. The model includes an overall energy balance for the diode, and changes the interelectrode gap spacing due to thermal expansion of the parts as the emitter and/or collector temperatures change. Cesium pressure can be chosen from an external liquid reservoir, an integral reservoir using cesium intercalated into graphite attached to the collector heat pipe, or optimum cesium pressure. With optimum cesium pressure, the maximum efficiency increases from 14% to 16% as the emitter temperature increases from 1,900 K to 2,200 K. The improvement in efficiency is only 2% as the emitter temperature is increased. Optimum efficiency requires an external, actively controlled liquid reservoir.

  12. TEC as electric generator in an automobile catalytic converter

    SciTech Connect (OSTI)

    Svensson, R. [Chalmers Univ. of Technology, Goeteborg (Sweden); Holmlid, L. [Univ. of Goeteborg (Sweden). Dept. of Physical Chemistry

    1996-12-31T23:59:59.000Z

    Modern cars use more and more electric power due to more on-board electric systems, e.g., ABS brakes, active suspension systems, electric windows, chair adjustment systems and electronic engine control systems. One possible energy source for electricity generation is to use the waste heat from the car`s engine, which generally is as much as 80% of the total energy from the combustion of the gasoline. Maybe the best location to tap the excess heat is the Catalytic Converter (Cat) in the exhaust system or perhaps at the exhaust pipes close to the engine. The Cat must be kept within a certain temperature interval. Large amounts of heat are dissipated through the wall of the Cat. A Thermionic Energy Converter (TEC) in coaxial form could conveniently be located around the ceramic cartridge of the Cat. Since the TEC is a rather good heat insulator before it reaches its working temperature the Cat will reach working temperature faster, and the final temperature of it can be controlled better when encapsulated in a concentric TEC arrangement. It is also possible to regulate the temperature of the Cat and the TEC by controlling the electrical load of the TEC. The possible working temperatures of present and future Cats appear very suitable for the new low work function collector TEC, which has been demonstrated to work down to 470 K.

  13. Triple voltage dc-to-dc converter and method

    DOE Patents [OSTI]

    Su, Gui-Jia (Knoxville, TN)

    2008-08-05T23:59:59.000Z

    A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

  14. Influence of adhesive shear deformation on laminate structural behavior with application to parabolic trough solar collectors. [SHEAR

    SciTech Connect (OSTI)

    Clauss, D.B.; Reuter, R.C. Jr.

    1983-02-01T23:59:59.000Z

    A simplified theory for the bending behavior of a thin flat bi-lamina panel is developed which includes the effects of shear deformation in the central adhesive layer. Static equilibrium equations for elastic thermomechanical cylindrical bending of a thin plate are used. A solution form is proposed which greatly facilitates application of this theory to structural panels with numerous discrete property changes in the variable direction. The influence of adhesive shear stiffness parameters upon overall laminate behavior is characterized through numerical examples typifying various thermal and mechanical loading conditions.

  15. Microscopic Origin of Shear Relaxation in Strongly Coupled Yukawa Liquids

    E-Print Network [OSTI]

    Ashwin J.; Abhijit Sen

    2014-08-01T23:59:59.000Z

    We report accurate molecular dynamics calculations of the shear stress relaxation in a two-dimensional strongly coupled Yukawa liquid over a wide range of the Coulomb coupling strength $\\Gamma$ and the Debye screening parameter $\\kappa$. Our data on the relaxation times of the ideal- , excess- and total shear stress auto-correlation ($\\tau^{id}_M, \\tau^{ex}_M, \\tau_M$ respectively) along with the lifetime of local atomic connectivity $\\tau_{LC}$ leads us to the following important observation. Below a certain crossover $\\Gamma_c(\\kappa)$, $\\tau_{LC} \\rightarrow \\tau^{ex}_M$, directly implying that here $\\tau_{LC}$ is the microscopic origin of the relaxation of excess shear stress unlike the case for ordinary liquids where it is the origin of the relaxation of the total shear stress. At $\\Gamma >> \\Gamma_c(\\kappa)$ i.e. in the potential energy dominated regime, $\\tau^{ex}_M\\rightarrow \\tau_M$ meaning that $\\tau^{ex}_M$ can fully account for the elastic or "solid like" behavior.

  16. THE SDSS CO-ADD: COSMIC SHEAR MEASUREMENT

    SciTech Connect (OSTI)

    Lin Huan; Dodelson, Scott; Soares-Santos, Marcelle; Annis, James; Hao Jiangang; Johnston, David; Kubo, Jeffrey M.; Reis, Ribamar R. R. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Seo, Hee-Jong [Berkeley Center for Cosmological Physics, LBL and Department of Physics, University of California, Berkeley, CA 94720 (United States); Simet, Melanie [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

    2012-12-10T23:59:59.000Z

    Stripe 82 in the Sloan Digital Sky Survey was observed multiple times, allowing deeper images to be constructed by co-adding the data. Here, we analyze the ellipticities of background galaxies in this 275 deg{sup 2} region, searching for evidence of distortions due to cosmic shear. We do so using measurements of both the shear-shear correlation function and power spectrum, with the latter determined using both ''quadratic'' and ''pseudo'' estimation techniques. We show how we verified these methods using mock catalogs. We also describe our methods for modeling and correcting for the effects of the point-spread function (PSF) in our shape measurements, and we also describe our prescription for estimating photometric redshifts (photo-z's) for our galaxy sample. In particular, we assess the impact of potential systematic effects due to the PSF and to photo-z's, and show that these are under control in our analysis. We find consistent correlation function and power spectrum results, where the E-mode cosmic shear signal is detected in both real and Fourier space with >5{sigma} significance on degree scales, while the B-mode is consistent with zero as expected. The amplitude of the signal constrains the combination of the matter density {Omega}{sub m} and fluctuation amplitude {sigma}{sub 8} to be {Omega}{sup 0.7}{sub m}{sigma}{sub 8} = 0.252{sup +0.032}{sub -{sub 0.052}}.

  17. Multi-scale investigation of sheared flows in magnetized plasmas

    SciTech Connect (OSTI)

    Thomas, Jr., Dr. Edward

    2014-09-19T23:59:59.000Z

    Flows parallel and perpendicular to magnetic fields in a plasma are important phenomena in many areas of plasma science research. The presence of these spatially inhomogeneous flows is often associated with the stability of the plasma. In fusion plasmas, these sheared flows can be stabilizing while in space plasmas, these sheared flows can be destabilizing. Because of this, there is broad interest in understanding the coupling between plasma stability and plasma flows. This research project has engaged in a study of the plasma response to spatially inhomogeneous plasma flows using three different experimental devices: the Auburn Linear Experiment for Instability Studies (ALEXIS) and the Compact Toroidal Hybrid (CTH) stellarator devices at Auburn University, and the Space Plasma Simulation Chamber (SPSC) at the Naval Research Laboratory. This work has shown that there is a commonality of the plasma response to sheared flows across a wide range of plasma parameters and magnetic field geometries. The goal of this multi-device, multi-scale project is to understand how sheared flows established by the same underlying physical mechanisms lead to different plasma responses in fusion, laboratory, and space plasmas.

  18. Modeling of strain rate effects on clay in simple shear

    E-Print Network [OSTI]

    Jung, Byoung Chan

    2006-08-16T23:59:59.000Z

    strength and log scale of strain rate. To include the effects of strain rate, the modified simple effective stress model starts with two assumptions: (1) a specific shear strength corresponds to a specific strain rate in a unique relation; and (2...

  19. CONTAINED PLASTIC DEFORMATION NEAR CRACKS AND NOTCHES UNDER LONGITUDINAL SHEAR

    E-Print Network [OSTI]

    CONTAINED PLASTIC DEFORMATION NEAR CRACKS AND NOTCHES UNDER LONGITUDINAL SHEAR James R. Rice* ABSTRACT An exact linear elastic-perfectly plastic solution is presented for the problem of a sharp notch coordinates corresponding to given stresses, position of the elastic-plastic boundary, and accompanying

  20. Gravity Waves in Shear and Implications for Organized Convection

    E-Print Network [OSTI]

    Stechmann, Samuel N.

    Gravity Waves in Shear and Implications for Organized Convection Samuel N. Stechmann Department, Los Angeles, CA 90095­1555. E-mail: stechmann@math.ucla.edu #12;ABSTRACT It is known that gravity, the gravity waves can create a more favorable environment on one side of preexisting convection than the other

  1. STEEL PLATE SHEAR WALL BUILDINGS: DESIGN REQUIREMENTS AND RESEARCH

    E-Print Network [OSTI]

    Bruneau, Michel

    STEEL PLATE SHEAR WALL BUILDINGS: DESIGN REQUIREMENTS AND RESEARCH Michel Bruneau, P.E. 1 Dr. Bruneau is conducting research on the seismic evaluation and retrofit of existing steel bridges, steel of this research, and has co- authored the book "Ductile Design of Steel Structures" published in 1997 by Mc

  2. Reinforcement Learning for Autonomous Dynamic Soaring in Shear Winds

    E-Print Network [OSTI]

    Spletzer, John R.

    Reinforcement Learning for Autonomous Dynamic Soaring in Shear Winds Corey Montella and John R energy from horizontal wind that varies in strength and/or direction to support flight. Typical approaches to dynamic soaring in autonomous unmanned aerial vehicles (UAVs) use nonlinear optimizers

  3. Shear-induced sedimentation in yield stress fluids Guillaume Ovarlez

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    if a given material will remain ho- mogeneous during a flow. Using MRI techniques, we study the time the local shear rate in the interstitial fluid. Keywords: Sedimentation; Yield stress fluid; Suspension; MRI some lift or dispersion forces to the particles. This principle is typically used in fluidization

  4. Quasistatic rheology of foams II. Continuous shear flow

    E-Print Network [OSTI]

    and numerically. We extract, from the images of the sheared foam, the plastic flow profiles and the modifications AND GEORGES DEBREGEAS2 1 Division of Engineering and Applied Sciences, Harvard University, Pierce Hall, 29 in the temporal and spatial correlations of the plastic events. The spa- tial fluctuations of the static stress

  5. Laboratory Studies on the Effects of Shear on Fish

    SciTech Connect (OSTI)

    Neitzel, Duane A.; Richmond, Marshall C.; Dauble, Dennis D.; Mueller, Robert P.; Moursund, Russell A.; Abernethy, Cary S.; Guensch, Greg R.

    2000-09-20T23:59:59.000Z

    The overall objective of our studies was to specify an index describing the hydraulic force that fish experience when subjected to a shear environment. Fluid shear is a phenomenon that is important to fish. However, elevated levels of shear may result in strain rates that injure or kill fish. At hydroelectric generating facilities, concerns have been expressed that strain rates associated with passage through turbines, spillways, and fish bypass systems may adversely affect migrating fish. Development of fish friendly hydroelectric turbines requires knowledge of the physical forces (injury mechanisms) that impact entrained fish and the fish's tolerance to these forces. It requires up-front, pre-design specifications for the environmental conditions that occur within the turbine system, in other words, determining or assuming that those conditions known to injure fish will provide the descriptions of conditions that engineers must consider in the design of a turbine system. These biological specifications must be carefully and thoroughly documented throughout the design of a fish friendly turbine. To address the development of biological specifications, we designed and built a test facility where juvenile fish could be subjected to a range of shear environments and quantified their biological response.

  6. Bounds on dissipation in magnetohydrodynamic Couette and Hartmann shear flows

    E-Print Network [OSTI]

    Morrison, Philip J.,

    of Mathematics, University of Michigan, Ann Arbor, Michigan 48109-1109 and Michigan Center for Theoretical Physics, Ann Arbor, Michigan 48109-1120 Received 2 May 2003; accepted 28 July 2003 Shear flow situation appears when the solar wind meets a magnetized object and the flow has to do work in bending

  7. Silicon micromachined sensors and sensor arrays for shear-stress measurements in aerodynamic flows

    E-Print Network [OSTI]

    Padmanabhan, Aravind

    In this thesis we report on a new micromachined floating-element shear-stress sensor for turbulent boundary layer research. Applications in low shear-stress environments such as turbulent boundary layers require extremely ...

  8. Phase-field simulations of viscous fingering in shear-thinning fluids

    E-Print Network [OSTI]

    Sebastien Nguyen; Roger Folch; Vijay K. Verma; Hervé Henry; Mathis Plapp

    2009-12-01T23:59:59.000Z

    A phase-field model for the Hele-Shaw flow of non-Newtonian fluids is developed. It extends a previous model for Newtonian fluids to a wide range of shear-dependent fluids. The model is applied to perform simulations of viscous fingering in shear- thinning fluids, and it is found to be capable of describing the complete crossover from the Newtonian regime at low shear rate to the strongly shear-thinning regime at high shear rate. The width selection of a single steady-state finger is studied in detail for a 2-plateaux shear-thinning law (Carreau law) in both its weakly and strongly shear-thinning limits, and the results are related to previous analyses. In the strongly shear-thinning regime a rescaling is found for power-law (Ostwald-de-Waehle) fluids that allows for a direct comparison between simulations and experiments without any adjustable parameters, and good agreement is obtained.

  9. E-Print Network 3.0 - atmospheric shear flow Sample Search Results

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

    flow at and above 200 hPa. Note that for all four shear profiles, the 850... , the vortex propagates to the left of the mean flow when initialized in a westerly shear...

  10. Shear flow effects on ion thermal transport in tokamaks

    SciTech Connect (OSTI)

    Tajima, T.; Horton, W.; Dong, J.Q. [Univ. of Texas, Austin, TX (United States). Institute for Fusion Studies; Kishimoto, Y. [JAERI (Japan). Naka Fusion Research

    1995-03-01T23:59:59.000Z

    From various laboratory and numerical experiments, there is clear evidence that under certain conditions the presence of sheared flows in a tokamak plasma can significantly reduce the ion thermal transport. In the presence of plasma fluctuations driven by the ion temperature gradient, the flows of energy and momentum parallel and perpendicular to the magnetic field are coupled with each other. This coupling manifests itself as significant off-diagonal coupling coefficients that give rise to new terms for anomalous transport. The authors derive from the gyrokinetic equation a set of velocity moment equations that describe the interaction among plasma turbulent fluctuations, the temperature gradient, the toroidal velocity shear, and the poloidal flow in a tokamak plasma. Four coupled equations for the amplitudes of the state variables radially extended over the transport region by toroidicity induced coupling are derived. The equations show bifurcations from the low confinement mode without sheared flows to high confinement mode with substantially reduced transport due to strong shear flows. Also discussed is the reduced version with three state variables. In the presence of sheared flows, the radially extended coupled toroidal modes driven by the ion temperature gradient disintegrate into smaller, less elongated vortices. Such a transition to smaller spatial correlation lengths changes the transport from Bohm-like to gyrobohm-like. The properties of these equations are analyzed. The conditions for the improved confined regime are obtained as a function of the momentum-energy deposition rates and profiles. The appearance of a transport barrier is a consequence of the present theory.

  11. Wind shear climatology for large wind turbine generators

    SciTech Connect (OSTI)

    Elliott, D.L.; Wendell, L.L.; Heflick, S.K.

    1982-10-01T23:59:59.000Z

    Climatological wind shear analyses relevant to the design and operation of multimegawatt wind turbines are provided. Insight is provided for relating the wind experienced by a rotating blade in a shear flow to the analysis results. A simple analysis of the wind experienced by a rotating blade for three types of wind shear profiles under steady-state conditions is presented in graphical form. Comparisons of the magnitude and frequency of the variations in 1) the wind sensed by a single blade element, 2) the sum, and 3) the difference of the winds sensed by opposite blade elements show strong sensitivity to profile shape. These three items represent forcing functions that can be related to 1) flatwise bending moment, 2) torque on the shaft, and 3) teeter angle. A computer model was constructed to simulate rotational sampling of 10-s sampled winds from a tall tower for three different types of large wind turbines. Time series produced by the model indicated that the forcing functions on a rotating blade vary according to the shear profile encountered during each revolution as opposed to a profile derived from average wind conditions, e.g., hourly average winds. An analysis scheme was developed to establish a climatology of wind shear profiles derived from 10-s sampled winds and hourly average winds measured over a one-year period at several levels on a tall tower. Because of the sensitivity of the forcing function variability to profile shape, the analyses performed and presented are in the form of joint frequency distributions of velocity differences of the the top-to-hub versus the hub-to-bottom portion of disks of rotation for the three turbine configurations.

  12. Further testing and development of an 11-watt Stirling converter

    SciTech Connect (OSTI)

    Ross, B.A.; Montgomery, W.L. [Stirling Technology Co., Richland, WA (United States)

    1995-12-31T23:59:59.000Z

    Three previous IECEC papers describe the development of an 11-watt Radioisotope Stirling Generator (RSG) intended for remote power applications. This paper describes more recent testing and development activities. Testing of the engineering model (EM) was performed to determine the effect of heat rejection temperature, thermal input and initial charge pressure on thermal efficiency. Shock testing of the generator included a drop test and 3 hours of testing in a random vibration environment where g{sup 2}/Hz = 0.04. Endurance testing of a complete Stirling converter continues, with over 15,000 maintenance-free operating hours. Endurance testing of critical subsystems and components has achieved 14,000 to 26,000 hours of operation without failure. Minor changes to the RSG prototype design, based on the development of the EM, are described.

  13. NREL Research on Converting Biomass to Liquid Fuels

    ScienceCinema (OSTI)

    None

    2013-05-29T23:59:59.000Z

    Unlike other renewable energy sources, biomass can be converted directly into liquid fuels, called "biofuels," to help meet transportation fuel needs. The two most common types of biofuels are ethanol and biodiesel. Today, ethanol is made from starches and sugars, but at the National Renewable Energy Laboratory (NREL) scientists are developing technology to allow it to be made from cellulose and hemicellulose, the fibrous material that makes up the bulk of most plant matter. Biodiesel is made by combining alcohol (usually methanol) with vegetable oil, animal fat, or recycled cooking grease. It can be used as an additive (typically 20%) to reduce vehicle emissions or in its pure form as a renewable alternative fuel for diesel engines. For a text version of this video visit http://www.nrel.gov/learning/re_biofuels.html

  14. A Study of Radiative Bottomonium Transitions using Converted Photons

    SciTech Connect (OSTI)

    Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Bari /Bari U.; Milanes, D.A.; /INFN, Bari; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum; Asgeirsson, D.J.; Hearty, C.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-08-15T23:59:59.000Z

    The authors use (111 {+-} 1) million {Upsilon}(3S) and (89 {+-} 1) million {Upsilon}(2S) events recorded by the BABAR detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions betwen bottomonium states using photons that have been converted to e{sup +}e{sup -} pairs by the detector material. They observe {Upsilon}(3S) {yields} {gamma}{chi}{sub b0,2}(1P) decay, make precise measurements of the branching fractions for {chi}{sub b1,2}(1P, 2P) {yields} {gamma}{Upsilon}(1S) and {chi}{sub b1,2}(2P) {yields} {gamma}{Upsilon}(2S) decays, and search for radiative decay to the {eta}{sub b}(1S) and {eta}{sub b}(2S) states.

  15. Apparatuses and method for converting electromagnetic radiation to direct current

    DOE Patents [OSTI]

    Kotter, Dale K; Novack, Steven D

    2014-09-30T23:59:59.000Z

    An energy conversion device may include a first antenna and a second antenna configured to generate an AC current responsive to incident radiation, at least one stripline, and a rectifier coupled with the at least one stripline along a length of the at least one stripline. An energy conversion device may also include an array of nanoantennas configured to generate an AC current in response to receiving incident radiation. Each nanoantenna of the array includes a pair of resonant elements, and a shared rectifier operably coupled to the pair of resonant elements, the shared rectifier configured to convert the AC current to a DC current. The energy conversion device may further include a bus structure operably coupled with the array of nanoantennas and configured to receive the DC current from the array of nanoantennas and transmit the DC current away from the array of nanoantennas.

  16. Utilizing zero-sequence switchings for reversible converters

    DOE Patents [OSTI]

    Hsu, John S.; Su, Gui-Jia; Adams, Donald J.; Nagashima, James M.; Stancu, Constantin; Carlson, Douglas S.; Smith, Gregory S.

    2004-12-14T23:59:59.000Z

    A method for providing additional dc inputs or outputs (49, 59) from a dc-to-ac inverter (10) for controlling motor loads (60) comprises deriving zero-sequence components (V.sub.ao, V.sub.bo, and V.sub.co) from the inverter (10) through additional circuit branches with power switching devices (23, 44, 46), transforming the voltage between a high voltage and a low voltage using a transformer or motor (42, 50), converting the low voltage between ac and dc using a rectifier (41, 51) or an H-bridge (61), and providing at least one low voltage dc input or output (49, 59). The transformation of the ac voltage may be either single phase or three phase. Where less than a 100% duty cycle is acceptable, a two-phase modulation of the switching signals controlling the inverter (10) reduces switching losses in the inverter (10). A plurality of circuits for carrying out the invention are also disclosed.

  17. Results from the microminiature thermionic converter demonstration testing program

    SciTech Connect (OSTI)

    King, Donald B.; Wyant, Francis J. [International Nuclear Safety Department, Sandia National Laboratories, MS-0744, Albuquerque, New Mexico 87185 (United States)] Luke, James R. [New Mexico Engineering Research Institute, 901 University Blvd. SE, Albuquerque, New Mexico 87106 (United States)

    1999-01-01T23:59:59.000Z

    Research is in progress to develop microminiature thermionic converters (MTCs) with high energy conversion efficiencies and variable operating temperatures using semiconductor integrated circuit (IC) fabrication methods. The use of IC techniques allows the fabrication of MTCs with cathode to anode spacing of several microns or less and with anode and cathode materials that will have work functions ranging from 1 eV to 3 eV. The small cathode to anode spacing and variable electrode work functions should allow the conversion of heat energy to relatively large current densities (up to tens of Amps/cm{sup 2}) at relatively high conversion efficiencies (15{endash}25{percent}). {copyright} {ital 1999 American Institute of Physics.}

  18. Spring structure for a thermionic converter emitter support arrangement

    DOE Patents [OSTI]

    Allen, D.T.

    1992-03-17T23:59:59.000Z

    A support is provided for use in a thermionic converter to support an end of an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially as its temperature changes. The emitter end is supported by a spring structure that includes a pair of Belleville springs, and the spring structure is supported by a support structure fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element at the front end, a larger metal main support at the rear end that is attached to the housing, and with a ceramic layer between them that is bonded by hot isostatic pressing to the metal element and metal main support. The spring structure can include a loose wafer captured between the Belleville springs. 7 figs.

  19. Spring structure for a thermionic converter emitter support arrangement

    SciTech Connect (OSTI)

    Allen, Daniel T. (La Jolla, CA)

    1992-01-01T23:59:59.000Z

    A support is provided for use in a thermionic converter to support an end of an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially as its temperature changes. The emitter end (34) is supported by a spring structure (44) that includes a pair of Belleville springs, and the spring structure is supported by a support structure (42) fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element (74) at the front end, a larger metal main support (76) at the rear end that is attached to the housing, and with a ceramic layer (80) between them that is bonded by hot isostatic pressing to the metal element and metal main support. The spring structure can include a loose wafer (120) captured between the Belleville springs.

  20. Low Head, Vortex Induced Vibrations River Energy Converter

    SciTech Connect (OSTI)

    Bernitsas, Michael B.; Dritz, Tad

    2006-06-30T23:59:59.000Z

    Vortex Induced Vibrations Aquatic Clean Energy (VIVACE) is a novel, demonstrated approach to extracting energy from water currents. This invention is based on a phenomenon called Vortex Induced Vibrations (VIV), which was first observed by Leonardo da Vinci in 1504AD. He called it ‘Aeolian Tones.’ For decades, engineers have attempted to prevent this type of vibration from damaging structures, such as offshore platforms, nuclear fuel rods, cables, buildings, and bridges. The underlying concept of the VIVACE Converter is the following: Strengthen rather than spoil vortex shedding; enhance rather than suppress VIV; harness rather than mitigate VIV energy. By maximizing and utilizing this unique phenomenon, VIVACE takes this “problem” and successfully transforms it into a valuable resource for mankind.

  1. NREL Research on Converting Biomass to Liquid Fuels

    SciTech Connect (OSTI)

    None

    2010-01-01T23:59:59.000Z

    Unlike other renewable energy sources, biomass can be converted directly into liquid fuels, called "biofuels," to help meet transportation fuel needs. The two most common types of biofuels are ethanol and biodiesel. Today, ethanol is made from starches and sugars, but at the National Renewable Energy Laboratory (NREL) scientists are developing technology to allow it to be made from cellulose and hemicellulose, the fibrous material that makes up the bulk of most plant matter. Biodiesel is made by combining alcohol (usually methanol) with vegetable oil, animal fat, or recycled cooking grease. It can be used as an additive (typically 20%) to reduce vehicle emissions or in its pure form as a renewable alternative fuel for diesel engines. For a text version of this video visit http://www.nrel.gov/learning/re_biofuels.html

  2. Mechanical properties of jammed packings of frictionless spheres under applied shear stress

    E-Print Network [OSTI]

    Hao Liu; Hua Tong; Ning Xu

    2015-02-03T23:59:59.000Z

    By minimizing a thermodynamic-like potential, we unbiasedly sample the potential energy landscape of soft and frictionless spheres under constant shear stress. We obtain zero-temperature jammed states under desired shear stresses and investigate their mechanical properties as a function of the shear stress. As a comparison, we also obtain jammed states from the quasistatic-shear sampling in which the shear stress is not well-controlled. Although the yield stresses determined by both samplings show the same power-law scaling with the compression from point $J$, i.e.~the jamming transition point at zero temperature and shear stress, for finite size systems, the quasistatic-shear sampling leads to a lower yield stress and a higher critical volume fraction of point $J$. The shear modulus of jammed solids decreases when increasing the shear stress. However, the shear modulus does not decay to zero at yielding. This discontinuous change of the shear modulus implies the discontinuous nature of the unjamming transition under nonzero shear stress, which is further verified by the observation of a discontinuous jump of the pressure from jammed solids to shear flows. The pressure jump decreases upon decompression and approaches zero at the critical-like point $J$, in analogy with well-known phase transitions under external field. The analysis of force networks in jammed solids reveals that the force distribution is more sensitive to the increase of the shear stress near point $J$. The force network anisotropy increases with the shear stress. Weak particle contacts near the average force and under large shear stresses exhibit asymmetric angle distribution.

  3. SHEARING BOX SIMULATIONS OF THE MRI IN A COLLISIONLESS PLASMA Prateek Sharma and Gregory W. Hammett

    E-Print Network [OSTI]

    Hammett, Greg

    of the MRI in a collision- less plasma, focusing on local simulations in the shearing box limit. Quataert et

  4. Third generation development of an 11-watt Stirling converter

    SciTech Connect (OSTI)

    Montgomery, W.L.; Ross, B.A.; Penswick, L.B. [Stirling Technology Co., Kennewick, WA (United States)

    1996-12-31T23:59:59.000Z

    This paper describes recent design enhancements, performance results, and development of an artificial neural network (ANN) model related to the Radioisotope Stirling Generator (RSG), an 11-watt converter designed for remote power applications. Design enhancements include minor changes to improve performance, increase reliability, facilitate fabrication and assembly for limited production, and reduce mass. Innovative modifications were effected to increase performance and improve reliability of the vacuum foil insulation (VFI) package and linear alternator. High and low operating temperature acceptance testing of the Engineering Model (EM) demonstrated the robust system characteristics. These tests were conducted for 1 week of operation each, with rejector temperatures of 95 C and 20 C, respectively. Endurance testing continues for a complete Stirling converter, the Development Model (DM), with over 25,000 hours of maintenance-free operation. Endurance testing of flexures has attained over 540 flexure-years and endurance testing of linear motors/alternators has achieved nearly 27,000 hours of operation without failure. An ANN model was developed and tested successfully on the DM. Rejection temperatures were varied between 3 C and 75 C while load voltages ranged between engine stall and displacer overstroke. The trained ANN model, based solely on externally measured parameters, predicted values of piston amplitude, displacer amplitude, and piston-displacer phase angle within {+-}2% of the measured values over the entire operating regime. The ANN model demonstrated its effectiveness in the long-term evaluation of free-piston Stirling machines without adding the complexity, reduced reliability, and increased cost of sophisticated diagnostic instrumentation.

  5. Reference Model 6 (RM6): Oscillating Wave Energy Converter.

    SciTech Connect (OSTI)

    Bull, Diana L; Smith, Chris; Jenne, Dale Scott; Jacob, Paul; Copping, Andrea; Willits, Steve; Fontaine, Arnold; Brefort, Dorian; Gordon, Margaret Ellen; Copeland, Robert; Jepsen, Richard A.

    2014-10-01T23:59:59.000Z

    This report is an addendum to SAND2013-9040: Methodology for Design and Economic Analysis of Marine Energy Conversion (MEC) Technologies. This report describes an Oscillating Water Column Wave Energy Converter reference model design in a complementary manner to Reference Models 1-4 contained in the above report. In this report, a conceptual design for an Oscillating Water Column Wave Energy Converter (WEC) device appropriate for the modeled reference resource site was identified, and a detailed backward bent duct buoy (BBDB) device design was developed using a combination of numerical modeling tools and scaled physical models. Our team used the methodology in SAND2013-9040 for the economic analysis that included costs for designing, manufacturing, deploying, and operating commercial-scale MEC arrays, up to 100 devices. The methodology was applied to identify key cost drivers and to estimate levelized cost of energy (LCOE) for this RM6 Oscillating Water Column device in dollars per kilowatt-hour (%24/kWh). Although many costs were difficult to estimate at this time due to the lack of operational experience, the main contribution of this work was to disseminate a detailed set of methodologies and models that allow for an initial cost analysis of this emerging technology. This project is sponsored by the U.S. Department of Energy's (DOE) Wind and Water Power Technologies Program Office (WWPTO), within the Office of Energy Efficiency & Renewable Energy (EERE). Sandia National Laboratories, the lead in this effort, collaborated with partners from National Laboratories, industry, and universities to design and test this reference model.

  6. Reference Model 5 (RM5): Oscillating Surge Wave Energy Converter

    SciTech Connect (OSTI)

    Yu, Y. H.; Jenne, D. S.; Thresher, R.; Copping, A.; Geerlofs, S.; Hanna, L. A.

    2015-01-01T23:59:59.000Z

    This report is an addendum to SAND2013-9040: Methodology for Design and Economic Analysis of Marine Energy Conversion (MEC) Technologies. This report describes an Oscillating Water Column Wave Energy Converter (OSWEC) reference model design in a complementary manner to Reference Models 1-4 contained in the above report. A conceptual design for a taut moored oscillating surge wave energy converter was developed. The design had an annual electrical power of 108 kilowatts (kW), rated power of 360 kW, and intended deployment at water depths between 50 m and 100 m. The study includes structural analysis, power output estimation, a hydraulic power conversion chain system, and mooring designs. The results were used to estimate device capital cost and annual operation and maintenance costs. The device performance and costs were used for the economic analysis, following the methodology presented in SAND2013-9040 that included costs for designing, manufacturing, deploying, and operating commercial-scale MEC arrays up to 100 devices. The levelized cost of energy estimated for the Reference Model 5 OSWEC, presented in this report, was for a single device and arrays of 10, 50, and 100 units, and it enabled the economic analysis to account for cost reductions associated with economies of scale. The baseline commercial levelized cost of energy estimate for the Reference Model 5 device in an array comprised of 10 units is $1.44/kilowatt-hour (kWh), and the value drops to approximately $0.69/kWh for an array of 100 units.

  7. Numerical study of compressibility effects on the reversed shear Alfvén eigenmode in tokamak plasma

    SciTech Connect (OSTI)

    Yu, Limin; Zhang, Xianmei [Department of Physics, East China University of Science and Technology, Shanghai 200237 (China)] [Department of Physics, East China University of Science and Technology, Shanghai 200237 (China); Sheng, Zheng-Mao [Department of Physics, Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China)] [Department of Physics, Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China)

    2013-08-15T23:59:59.000Z

    Compressibility effects on the reversed shear Alfvén eigenmode in tokamak plasma are studied numerically. It is shown that compressibility is favorable for the existence of the reversed shear Alfvén eigenmode even without the pressure gradient, and the frequency of the reversed shear Alfvén eigenmode is modified by the geodesic frequency, which is consistent with an analytical theory.

  8. Free magnetohydrodynamic shear layers in the presence of rotation and magnetic fielda)

    E-Print Network [OSTI]

    Ji, Hantao

    Free magnetohydrodynamic shear layers in the presence of rotation and magnetic fielda) E. J. Spence and numerical study of hydrodynamic and magnetohydrodynamic free shear layers and their stability. We first typically reach zero velocity at the bounding wall. A shear layer is called "free" when it exists

  9. Reflective Cracking Study: First-level Report on Laboratory Shear Testing

    E-Print Network [OSTI]

    Tsai, Bor-Wen; Jones, David; Harvey, John T; Monismith, Carl L.; Guada, I.; Signore, J,

    2008-01-01T23:59:59.000Z

    2 and ? 2 ln? 3 and ? 3 lnG lnkcy5 lnn 1 lnn 2 lnNf lnpct559 Figure 4.28: Residual plots of LnG. (Pooled ShearResilient Shear Modulus, G* (lng) The Resilient Shear

  10. Geosynthetics International, 2004, 11, No. 3 State-of-the-art report: GCL shear strength and

    E-Print Network [OSTI]

    strength and shear strength testing of geosynthetic clay liners (GCLs). Essential concepts of shear stress, No. 3, 141­175 1. INTRODUCTION Internal and interface shear strengths of geosynthetic clay liners, and future research needs are identified. KEYWORDS: Geosynthetics, Bentonite, Durability, Geosynthetic clay

  11. Figure 1: Multiplex logarithmic microfluidic perfusion array for probing shear stress effects on stem cells. (A)

    E-Print Network [OSTI]

    Voldman, Joel

    Figure 1: Multiplex logarithmic microfluidic perfusion array for probing shear stress effects on stem cells. (A) Microfluidic perfusion systems exhibit more defined shear stress profiles and consume. (B) A 1x6 multiplex logarithmic microfluidic array for simultaneous application of shear stress

  12. Abstract--This paper presents the harmonic analysis of offshore wind farm (OWF) models with full converters

    E-Print Network [OSTI]

    Bak, Claus Leth

    to the transmission system by long HV cables. This generates advantages such as higher power system reliability with an induction generator and a full- scale converter. Full-rated power converter applied in wind turbines is used the converter to find a broad application in the wind power industry. This kind of power converter includes

  13. Solar energy power generators with advanced thermionic converters for spacecraft applications

    SciTech Connect (OSTI)

    Sahin, S.

    1981-01-01T23:59:59.000Z

    This study presents (1) a 50 kW/sub e/ solar energy generator in a geostationary orbit for direct tv-broadcasting and (2) a 10 GW/sub e/ space power plant, with the basic engineering outlines using an advanced thermionic converter proposal given for each. Further, a comparison of the main technical data for the generators with corresponding energy output using (1) advanced thermionic converter and (2) ordinary thermionic converter without auxiliary emitter is shown. 25 refs.

  14. Soft-Switching High-Frequency AC-Link Universal Power Converters with Galvanic Isolation

    E-Print Network [OSTI]

    Amirabadi, Mahshid

    2013-08-07T23:59:59.000Z

    ) direct drive using wound-field synchronous generator [10]. ...................................................................................................... 6 Figure 6 Dc-dc buck-boost converter: (a) configuration, (b) energizing mode (mode 1), (c...) de-energizing mode (mode 2), (d) voltage and current waveforms ........ 12 Figure 7 An alternative representation of the dc-dc buck-boost converter ...................... 13 Figure 8 Dc-dc ac-link buck-boost converter: configuration, behavior...

  15. Application of direct pulsewidth modulation scheme to AC-DC converters: - a way to reduce ripple

    E-Print Network [OSTI]

    Zhang, Yuemin

    1993-01-01T23:59:59.000Z

    Modulation (ISPWM), 4 Direct Pulsewidth Modulation (DPWM). 15 5 Single Phase Half Controlled PWM ac-dc Converter . 6 Single Phase Full controlled PWM ac-dc Converter . 18 18 7 Simulation of SPWM ac-dc Converter. 20 8 Output Voltage Spectra of SPWM ac... 30 Balanced Three Phase Inputs 31 Output Voltage of A Three Phase Full Controlled ac-dc SPWM Converter. 42 32 Output Voltage of A Three Phase Full Controlled ac-dc EPWM Con- verter 33 Output Voltage of A Three Phase Full Controlled ac-dc ISPWM Con...

  16. E-Print Network 3.0 - analog-to-digital converters Sample Search...

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

    ARCHITECTURE FOR MASKED SUCCESSIVE Summary: performance, low power, and low electromagnetic interference (EMI) analog-to-digital converters (ADCs) has led... and A. Zayegh, "A...

  17. Wet-process dust-collecting apparatus especially for converter exhaust gases

    SciTech Connect (OSTI)

    Baab, H.

    1985-03-19T23:59:59.000Z

    Metallurgical converter gas is scrubbed in a wet-process electrostatic precipitator utilizing a cylindrical housing and axially separated collecting fields which themselves are vertically subdivided.

  18. E-Print Network 3.0 - alpha converting enzyme Sample Search Results

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

    of Bartlett for the underlying "universe" pdf p:unapply(convert(series(exp(x),x0,tay),polynom),x); p : x1 Source: Finner, Helmut - Mathematisches Institut,...

  19. New Family of Multilevel Matrix Converters for Wind Power Applications: Final Report, July 2002 - March 2006

    SciTech Connect (OSTI)

    Erickson, R.; Angkititrakul, S.; Almazeedi, K.

    2006-12-01T23:59:59.000Z

    The goal of this project was to develop a new modular multilevel matrix converter for wind power applications and to demonstrate a working scale model in the laboratory.

  20. angiotensin-converting enzyme levels: Topics by E-print Network

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

    enzyme activity is significantly determined by a gene polymorphism. Homozygous Brown Norway rats have higher plasma angiotensin I-converting enzyme (more) Jalil Milad, Jorge...

  1. Coal-fired furnace for testing of thermionic converters. Topical report

    SciTech Connect (OSTI)

    Not Available

    1980-10-01T23:59:59.000Z

    The development of thermionic converter technology has progressed to make near-term applications interesting. One of these applications is the thermionic topping of a pulverized coal-fired central station powerplant. Up to now, thermionic converters have been flame tested using natural gas as fuel. A new test furnace is required for evaluation of thermionic converters in a coal-fired environment. The design and costs of a facility which adapts a coal-fired furnace built by Foster Wheeler Development Corporation (FWDC) for thermionic converter testing are discussed. Such a facility would be exempt from air pollution regulations because of its low firing rate.

  2. Bibliography on overvoltage protection and insulation coordination of HVDC converter stations, 1979-1989

    SciTech Connect (OSTI)

    Not Available

    1991-04-01T23:59:59.000Z

    This bibliography is a listing of references on the subject of overvoltage protection and insulation coordination of HVDC converter stations, for the years 1979 through 1989.

  3. DC-DC Converter Topology Assessment for Large Scale Distributed Photovoltaic Plant Architectures

    SciTech Connect (OSTI)

    Mohammed S. Agamy; Maja Harfman-Todorovic; Ahmed Elasser; Juan A. Sabate; Robert L. Steigerwald; Yan Jiang; Somasundaram Essakiappan

    2011-07-01T23:59:59.000Z

    Distributed photovoltaic (PV) plant architectures are emerging as a replacement for the classical central inverter based systems. However, power converters of smaller ratings may have a negative impact on system efficiency, reliability and cost. Therefore, it is necessary to design converters with very high efficiency and simpler topologies in order not to offset the benefits gained by using distributed PV systems. In this paper an evaluation of the selection criteria for dc-dc converters for distributed PV systems is performed; this evaluation includes efficiency, simplicity of design, reliability and cost. Based on this evaluation, recommendations can be made as to which class of converters is best fit for this application.

  4. E-Print Network 3.0 - angiotensin-i-converting enzyme ace Sample...

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

    Macrophage Angiotensin- Summary: of Human Genetics, University of Utah, Salt Lake City, Utah Angiotensin-converting enzyme (ACE) is a pepti... enzyme. Somatic ACE and testis...

  5. E-Print Network 3.0 - angiotensin i-converting enzyme Sample...

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

    angiotensin-converting enzyme (ACE), but no ACE... , University of Utah, Salt Lake City, Utah To investigate the local effects of angiotensin II ... Source: Capecchi, Mario R....

  6. High efficiency resonant dc/dc converter for solar power applications .

    E-Print Network [OSTI]

    Inam, Wardah

    2013-01-01T23:59:59.000Z

    ??This thesis presents a new topology for a high efficiency dc/dc resonant power converter that utilizes a resistance compression network to provide simultaneous zero voltage… (more)

  7. E-Print Network 3.0 - analog to digital converters Sample Search...

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

    The objective of this lab... is to analyze, construct, and test a four bit weighted resistor digital to analog converter. The required... digital to ... Source: Landers, Robert...

  8. MAGNETIC FIELD GENERATION AND PARTICLE ENERGIZATION AT RELATIVISTIC SHEAR BOUNDARIES IN COLLISIONLESS ELECTRON-POSITRON PLASMAS

    SciTech Connect (OSTI)

    Liang, Edison; Smith, Ian [Rice University, MS 108, 6100 Main Street, Houston, TX 77005 (United States); Boettcher, Markus, E-mail: liang@rice.edu, E-mail: iansmith@rice.edu, E-mail: boettchm@ohio.edu [Physics and Astronomy Department, Ohio University, Athens, OH 45701 (United States)

    2013-04-01T23:59:59.000Z

    Using particle-in-cell simulations, we study the kinetic physics of relativistic shear flow in collisionless electron-positron (e+e-) plasmas. We find efficient magnetic field generation and particle energization at the shear boundary, driven by streaming instabilities across the shear interface and sustained by the shear flow. Nonthermal, anisotropic high-energy particles are accelerated across field lines to produce a power-law tail turning over just below the shear Lorentz factor. These results have important implications for the dissipation and radiation of jets in blazars and gamma-ray bursts.

  9. Triaxial determination of shear strength of tire chips

    SciTech Connect (OSTI)

    Wu, W.Y.; Benda, C.C.; Cauley, R.F. [Vermont Agency of Transportation, Montpelier, VT (United States)

    1997-05-01T23:59:59.000Z

    Triaxial compression tests following stress paths of constant {sigma}{sub 1} were conducted to determine the shear strength of five processed scrap tire products having different gradations and particle shapes. The interparticle frictional component was separated from the total shear strength according to the energy correction concept proposed by researchers. The experimental results show that all five tire chip products have ultimate internal friction angles of 45{degree} to over 60{degree}. The interparticle frictional component of the strength was fully mobilized and nearly reached a constant value after approximately 5% axial strain. The experimental results confirmed that the strength parameter obtained with constant {sigma}{sub 1} was more reasonable. This finding is supported by field observation in which the tire chips have an angle of repose ranging from 37{degree} to 43{degree} (loosely stock piled) and up to 85{degree} (compacted). The engineering applications of the experimental results are discussed.

  10. Plasticity of a colloidal polycrystal under cyclic shear

    E-Print Network [OSTI]

    Elisa Tamborini; Luca Cipelletti; Laurence Ramos

    2014-08-27T23:59:59.000Z

    We use confocal microscopy and time-resolved light scattering to investigate plasticity in a col- loidal polycrystal, following the evolution of the network of grain boundaries as the sample is submitted to thousands of shear deformation cycles. The grain boundary motion is found to be ballistic, with a velocity distribution function exhibiting non-trivial power law tails. The shear- induced dynamics initially slow down, similarly to the aging of the spontaneous dynamics in glassy materials, but eventually reach a steady state. Surprisingly, the cross-over time between the ini- tial aging regime and the steady state decreases with increasing probed length scale, hinting at a hierarchical organization of the grain boundary dynamics.

  11. No-hair conjectures, primordial shear and protoinflationary initial conditions

    E-Print Network [OSTI]

    Massimo Giovannini

    2013-12-17T23:59:59.000Z

    Anisotropic inflationary background geometries are analyzed in the context of an extended gauge action where the electric and magnetic susceptibilities are not bound to coincide and depend on the inflaton field. After deriving various classes of solutions with electric and magnetic hairs, we discuss the problem of the initial boundary conditions of the shear parameter and consider a globally neutral plasma as a possible relic of a preinflationary stage of expansion. While electric hairs are washed out by the finite value of the protoinflationary conductivity, magnetic hairs can persist and introduce a tiny amount of shear causing a different inflationary rate of expansion along orthogonal spatial directions. The plasma interactions are a necessary criterion to discriminate between physical and unphysical initial conditions but they are not strictly sufficient to warrant the stability of a given magnetic solution.

  12. Finite element analyses for seismic shear wall international standard problem

    SciTech Connect (OSTI)

    Park, Y.J.; Hofmayer, C.H.

    1998-04-01T23:59:59.000Z

    Two identical reinforced concrete (RC) shear walls, which consist of web, flanges and massive top and bottom slabs, were tested up to ultimate failure under earthquake motions at the Nuclear Power Engineering Corporation`s (NUPEC) Tadotsu Engineering Laboratory, Japan. NUPEC provided the dynamic test results to the OECD (Organization for Economic Cooperation and Development), Nuclear Energy Agency (NEA) for use as an International Standard Problem (ISP). The shear walls were intended to be part of a typical reactor building. One of the major objectives of the Seismic Shear Wall ISP (SSWISP) was to evaluate various seismic analysis methods for concrete structures used for design and seismic margin assessment. It also offered a unique opportunity to assess the state-of-the-art in nonlinear dynamic analysis of reinforced concrete shear wall structures under severe earthquake loadings. As a participant of the SSWISP workshops, Brookhaven National Laboratory (BNL) performed finite element analyses under the sponsorship of the U.S. Nuclear Regulatory Commission (USNRC). Three types of analysis were performed, i.e., monotonic static (push-over), cyclic static and dynamic analyses. Additional monotonic static analyses were performed by two consultants, F. Vecchio of the University of Toronto (UT) and F. Filippou of the University of California at Berkeley (UCB). The analysis results by BNL and the consultants were presented during the second workshop in Yokohama, Japan in 1996. A total of 55 analyses were presented during the workshop by 30 participants from 11 different countries. The major findings on the presented analysis methods, as well as engineering insights regarding the applicability and reliability of the FEM codes are described in detail in this report. 16 refs., 60 figs., 16 tabs.

  13. Theory of semicollisional kinetic Alfven modes in sheared magnetic fields

    SciTech Connect (OSTI)

    Hahm, T.S.; Chen, L.

    1985-02-01T23:59:59.000Z

    The spectra of the semicollisional kinetic Alfven modes in a sheared slab geometry are investigated, including the effects of finite ion Larmor radius and diamagnetic drift frequencies. The eigenfrequencies of the damped modes are derived analytically via asymptotic analyses. In particular, as one reduces the resistivity, we find that, due to finite ion Larmor radius effects, the damped mode frequencies asymptotically approach finite real values corresponding to the end points of the kinetic Alfven continuum.

  14. Evolution of shear-induced melting in dusty plasma

    E-Print Network [OSTI]

    Yan Feng; J. Goree; Bin Liu

    2010-04-05T23:59:59.000Z

    The spatiotemporal development of melting is studied experimentally in a 2D dusty plasma suspension. Starting with an ordered lattice, and then suddenly applying localized shear, a pair of counter-propagating flow regions develop. A transition between two melting stages is observed before a steady state is reached. Melting spreads with a front that propagates at the transverse sound speed. Unexpectedly, coherent longitudinal waves are excited in the flow region.

  15. Intensive neutrino source on the base of lithium converter

    E-Print Network [OSTI]

    Lyashuk, V I

    2015-01-01T23:59:59.000Z

    An intensive antineutrino source with a hard spectrum (with energy up to 13 MeV, average energy 6.5 MeV) can be realized on the base of beta-decay of short living isotope 8Li (0.84 s). The 8Li isotope (generated in activation of 7Li isotope) is a prime perspective antineutrino source owing to the hard antineutrino spectrum and square dependence of cross section on the energy. Up today nuclear reactors are the most intensive neutrino sources. Antineutrino reactor spectra have large uncertainties in the summary antineutrino spectrum at energy E>6 MeV. Use of 8Li isotope allows to decrease sharply the uncertainties or to exclude it completely. An intensive neutron fluxes are requested for rapid generation of 8Li isotope. The installations on the base of nuclear reactors can be an alternative for nuclear reactors as traditional neutron sources. It is possible creation of neutrino sources another in principle: on the base of tandem of accelerators, neutron generating targets and lithium converter. An intensive neu...

  16. Advanced Gate Drive for the SNS High Voltage Converter Modulator

    SciTech Connect (OSTI)

    Nguyen, M.N.; Burkhart, C.; Kemp, M.A.; /SLAC; Anderson, D.E.; /Oak Ridge

    2009-05-07T23:59:59.000Z

    SLAC National Accelerator Laboratory is developing a next generation H-bridge switch plate [1], a critical component of the SNS High Voltage Converter Modulator [2]. As part of that effort, a new IGBT gate driver has been developed. The drivers are an integral part of the switch plate, which are essential to ensuring fault-tolerant, high-performance operation of the modulator. The redesigned driver improves upon the existing gate drive in several ways. The new gate driver has improved fault detection and suppression capabilities; suppression of shoot-through and over-voltage conditions, monitoring of dI/dt and Vce(sat) for fast over-current detection and suppression, and redundant power isolation are some of the added features. In addition, triggering insertion delay is reduced by a factor of four compared to the existing driver. This paper details the design and performance of the new IGBT gate driver. A simplified schematic and description of the construction are included. The operation of the fast over-current detection circuits, active IGBT over-voltage protection circuit, shoot-through prevention circuitry, and control power isolation breakdown detection circuit are discussed.

  17. Digital regulation of a phase controlled power converter

    SciTech Connect (OSTI)

    Schultheiss, C.; Haque, T.

    1995-12-01T23:59:59.000Z

    The Relativistic Heavy Ion Collider, now in construction at Brookhaven National Laboratory, will use phase controlled power converters for the main dipole and quadrupole magnet strings. The rectifiers in these power supplies will be controlled by a digital regulator based on the TI 320C30 Digital Signal Processor (DSP). The DSP implements the current loop, the voltage loop, and a system to actively reduce the sub-harmonic ripple components. Digital firing circuits consisting of a phase locked lop and counters are used to fire the SCRs. Corrections for the sub-harmonic reduction are calculated by the DSP and stored in registers in the firing circuit. These corrections are added in hardware, to the over-all firing count provided by the DSP. the resultant count is compared to a reference counter to fire the SCRs. This combination of a digital control system and the digital firing circuits allows the correction of the sub-harmonics in a real-time sense. A prototype of the regulator has been constructed, and the preliminary testing indicates a sub-harmonic reduction of 60 dB.

  18. Fast pulsing of an open research thermionic converter

    SciTech Connect (OSTI)

    Svensson, R. [Coll. of Applied Engineering and Maritime Studies, Goeteborg (Sweden); [Chalmers Univ. of Technology, Goeteborg (Sweden); Holmlid, L. [Univ. of Goeteborg (Sweden). Dept. of Chemistry

    1997-12-31T23:59:59.000Z

    Several experiments concerning anomalous phenomena in an open Thermionic Energy Converter (TEC) have previously been reported. Under certain conditions a very high electron current (back current), flowing from the cold collector to the hot emitter, has been observed. This phenomenon has been studied with various methods. The conclusion is that an excited form of matter, with a very low work function, is located on the collector surface and in the interelectrode space. The matter consists of highly excited cesium atoms in a condensed form, and is referred to as Rydberg matter (RM). The existence of RM has been predicted theoretically by Manykin, et al. The efficiency of the RM TEC varies considerably with parameters such as emitter temperature and collector temperature. There is also a discrepancy between the apparent collector work function when the collector is run as electron emitter and when it is used as an electron collector. From other experiments the authors conclude that negative ions Cs{sup {minus}} will form on the RM surface on the collector. In order to control the effect of possible negative ions, a series of experiments including rapid pulsing of the TEC is in progress. The objective of the pulsing is to use a negative pulse (with respect to the collector) to remove possible negative ions from the RM surface and restore the low work function of the RM surface.

  19. Method of converting environmentally pollutant waste gases to methanol

    SciTech Connect (OSTI)

    Pfingstl, H.; Martyniuk, W.; Hennepin, A. Ill; McNally, T.; Myers, R.; Eberle, L.

    1993-08-03T23:59:59.000Z

    A continuous flow method is described of converting environmentally pollutant by-product gases emitted during the manufacture of silicon carbide to methanol comprising: (a) operating a plurality of batch furnaces of a silicon carbide manufacturing plant thereby producing silicon carbide and emitting by-product gases during the operation of the furnaces; (b) staggering the operation of the batch furnaces to achieve a continuous emission of the by-product gases; (c) continuously flowing the by-product gases as emitted from the batch furnaces directly to a methanol manufacturing plant; (d) cleansing the by-product gases of particulate matter, including removing the element sulfur from the by-product gases, as they are flowed to the methanol manufacturing plant, sufficiently for use of the by-product gases in producing methanol; and (e) immediately producing methanol from the by-product gases at the methanol manufacturing plant whereby the producing of silicon carbide is joined with the producing of methanol as a unified process.

  20. Converting acoustic energy into useful other energy forms

    DOE Patents [OSTI]

    Putterman, Seth J. (Sherman Oaks, CA); Barber, Bradley Paul (Northridge, CA); Hiller, Robert Anthony (Los Angeles, CA); Lofstedt, Ritva Maire Johanna (Los Angeles, CA)

    1997-01-01T23:59:59.000Z

    Sonoluminescence is an off-equilibrium phenomenon in which the energy of a resonant sound wave in a liquid is highly concentrated so as to generate flashes of light. The conversion of sound to light represents an energy amplification of eleven orders of magnitude. The flashes which occur once per cycle of the audible or ultrasonic sound fields can be comprised of over one million photons and last for less 100 picoseconds. The emission displays a clocklike synchronicity; the jitter in time between consecutive flashes is less than fifty picoseconds. The emission is blue to the eye and has a broadband spectrum increasing from 700 nanometers to 200 nanometers. The peak power is about 100 milliWatts. The initial stage of the energy focusing is effected by the nonlinear oscillations of a gas bubble trapped in the liquid. For sufficiently high drive pressures an imploding shock wave is launched into the gas by the collapsing bubble. The reflection of the shock from its focal point results in high temperatures and pressures. The sonoluminescence light emission can be sustained by sensing a characteristic of the emission and feeding back changes into the driving mechanism. The liquid is in a sealed container and the seeding of the gas bubble is effected by locally heating the liquid after sealing the container. Different energy forms than light can be obtained from the converted acoustic energy. When the gas contains deuterium and tritium there is the feasibility of the other energy form being fusion, namely including the generation of neutrons.

  1. Control of Parallel-Connected Bidirectional AC-DC Converters in Stationary Frame for Microgrid

    E-Print Network [OSTI]

    Teodorescu, Remus

    Control of Parallel-Connected Bidirectional AC-DC Converters in Stationary Frame for Microgrid-- With the penetration of renewable energy in modern power system, microgrid has become a popular application worldwide. In this paper, parallel-connected bidirectional converters for AC and DC hybrid microgrid application

  2. Ancillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power Plants

    E-Print Network [OSTI]

    Chen, Zhe

    presents a simulation model of a wind power plant based on a MW-level variable speed wind turbineAncillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power Plants Weihao Hu with a full-scale back-to-back power converter developed in the simulation tool of DIgSILENT Power Factory

  3. Application of wave generator theory to the development of a Wave Energy Converter

    E-Print Network [OSTI]

    Wood, Stephen L.

    Application of wave generator theory to the development of a Wave Energy Converter by Maila Sepri approve the attached thesis Application of wave generator theory to the development of a Wave Energy Application of wave generator theory to the development of a Wave Energy Converter by Maila Sepri Principal

  4. MODULAR MULTI-LEVEL CONVERTER BASED HVDC SYSTEM FOR GRID CONNECTION OF OFFSHORE WIND

    E-Print Network [OSTI]

    Chaudhary, Sanjay

    MODULAR MULTI-LEVEL CONVERTER BASED HVDC SYSTEM FOR GRID CONNECTION OF OFFSHORE WIND POWER PLANT U off-shore wind power plants. The MMC consists of a large number of simple voltage sourced converter offshore wind power plants (WPP) because they offer higher energy yield due to a superior wind profile

  5. The Valuation of Convertible Bonds With Credit Risk P. A. Forsyth K. R. Vetzal

    E-Print Network [OSTI]

    Forsyth, Peter A.

    The Valuation of Convertible Bonds With Credit Risk E. Ayache P. A. Forsyth K. R. Vetzal April 22 upon the history of its stock price. This paper explores the valuation of convertible bonds subject implicit method to decou- ple the system of linear complementarity problems at each timestep. Numerical

  6. A Dual-Supply Buck Converter with Improved Light-Load Efficiency

    E-Print Network [OSTI]

    Zhang, Chao

    2012-07-16T23:59:59.000Z

    to the switching losses that do not scale with load current. In this research, a novel technique for buck converter is proposed to reduce the switching loss by reducing the effective voltage supply at light load. This buck converter, implemented in TSMC 0...

  7. Sliding Mode Control of Boost Converter: Application to energy storage system via supercapacitors

    E-Print Network [OSTI]

    Boyer, Edmond

    Sliding Mode Control of Boost Converter: Application to energy storage system via supercapacitors», «Robust control», «Supercapacitor». Abstract Sliding mode control of boost converter is studied. In order of an energy storage system based on supercapacitors technology in order to regulate the output voltage. Given

  8. Design of a Boost Power Factor Correction Converter Using Optimization Techniques Sergio Busquets-Monge1

    E-Print Network [OSTI]

    Lindner, Douglas K.

    -end converter with an input electromagnetic interference filter. The system design variables are first correction, boost, electromagnetic interference, electromagnetic compatibility. Paper presented at PESC, June of a boost power factor correction front-end converter with an input electromagnetic interference filter

  9. May, 2010DC/DC CONVERTER FOR A SMALL SCALE WIND HYDROGEN SYSTEM

    E-Print Network [OSTI]

    Joel M. Jacobs; Joel M. Jacobs; Joel Michael Jacobs; Adviser Jerry; L. Hudgins

    An electronic converter is designed for an isolated renewable energy system. In this system, energy produced by a small wind turbine is used to extract hydrogen from water. Unique aspects of this application that affect the performance of the converter will be defined. Design considerations of the individual components will be discussed. Calculations on performance and validation of those calculations are also presented.

  10. A Passivity-Based Controller for coordination of converters in a Fuel Cell System

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    and hybrid vehicles has increased since 2009. In this context, the development of a fuel cell (FC) system, , A Passivity-Based Controller for coordination of converters in a Fuel Cell System M. Hilaireta-mail: mickael.hilairet@lgep.supelec.fr Abstract The problem of converters coordination of a fuel cell system

  11. Design and development of a DC-DC converter for a fuel cell inverter system

    E-Print Network [OSTI]

    Gopinath, Rajesh

    2001-01-01T23:59:59.000Z

    This thesis outlines the design and development of a DC-DC converter for a fuel cell inverter application. The proposed DC-DC converter was designed and tested at Texas A&M to meet the specifications laid down for the '2001 Future Energy Challenge...

  12. Regenerative Braking for an Electric Vehicle Using Ultracapacitors and a Buck-Boost Converter

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    Regenerative Braking for an Electric Vehicle Using Ultracapacitors and a Buck-Boost Converter Juan for an Electric Vehicle has been simulated. The purpose of this device is to allow higher accelerations, similar in shape and size to a Chevrolet S-10. This vehicle was already converted to an electric car

  13. Multi-Stage Converters: A New Technology for Traction Drive Juan W. Dixon

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    demonstrated the feasibility to build multi-stage converters for real electric vehicles or electric buses of electric vehicles. On the other hand, the PWM techniques used today to control modern static converters of Electrical Engineering Pontificia Universidad Católica de Chile Felipe Ríos, and Alberto Bretón Department

  14. Real-Time Simulation of Matrix Converter Drives **The University of Wisconsin-

    E-Print Network [OSTI]

    Lipo, Thomas

    IGBT/GTO/MOSFET firing pulses from high performance I/O thus permitting matrix converter controller with diodes (except in the case of RB-IGBT). An input filter and voltage clamp circuit complete the circuit Matrix converter a b c u v w Clamp circuit Inductive load Sawp Bi-directional switch on off iu iv iw Fig

  15. Ac-Ac Dual Active Bridge Converter for Solid State Transformer

    E-Print Network [OSTI]

    Kimball, Jonathan W.

    flow. The advantages of direct ac-ac conversion include fewer power conversion stages and minimized single-stage direct ac-ac power conversion to an SST. Fewer conversion stages reduce conduction loss) converter in direct ac-ac power conversion. Like a DAB converter as dc-dc power supply in [5] and [6

  16. The method of creating a small interelectrode spacing in thermionic energy converters

    SciTech Connect (OSTI)

    Kalandarishvili, A.G. [Russian Research Center Kurchatov Inst., Moscow (Russian Federation)

    1996-12-31T23:59:59.000Z

    The method is proposed for creating a small interelectrode spacing in thermionic energy converters (TEC) using graphite-based laminated structures placed inside the converter interelectrode gap. The paper discusses conceptual design and fabrication technology of this device. The proposed method is compared with the methods currently implemented in practice.

  17. All optical gray code to BCD converter e-mail : nkpark@plaza.snu.ac.kr

    E-Print Network [OSTI]

    Park, Namkyoo

    [. 1] / [ 2] / All optical gray code to BCD converter *1) , 2) , 2) , 2) , 1) 1) , 2 to binary-coded-decimal (BCD) converter for the first time in our knowledge utilizing cross gain modulations-level-simplification-method that has been used in electronics, we successfully designed the 4-bit all-optical Gray- code to BCD

  18. Solar Power To Help Convert Carbon Dioxide Into Fuel : Renewable Energy News

    E-Print Network [OSTI]

    Lovley, Derek

    Solar Power To Help Convert Carbon Dioxide Into Fuel : Renewable Energy News TUESDAY 25 MAY, 2010 | | Solar Power To Help Convert Carbon Dioxide Into Fuel by Energy Matters Microbiologist Derek Lovley of energy, the solar panels, can also harvest energy 100 times more effectively than plants. Other

  19. Coordination of Converter and Fuel Cell Controllers Kyung-Won Suh and Anna G. Stefanopoulou

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    , such as an air delivery system which supplies oxygen using a compressor or a blower, a hydrogen delivery system with a compressor and a DC-DC converter. We then employ model-based control techniques to tune two separate controllers for the compressor and the converter. We demonstrate that the lack of communication

  20. Boost Converter Provides Temperature-Controlled Operation of 12V Fan from +5V Supply

    E-Print Network [OSTI]

    McNeill, John A.

    enclosure, and reducing the fan supply voltage when maximum cooling is not necessary. Reducing the operatingBoost Converter Provides Temperature-Controlled Operation of 12V Fan from +5V Supply John Mc converter shown in Fig. 1 allows operation of a 12V brushless DC fan from a +5V supply. The circuit is based

  1. SINGULAR PERTURBATION CONTROL FOR COORDINATION OF CONVERTERS IN A FUEL CELL SYSTEM

    E-Print Network [OSTI]

    - In this paper, the converters coordination problem of a fuel cell system involving a hydrogen fuel cell (FC the problem of the power management of an hydrogen Fuel Cell (FC) system associated to a reversible impulseSINGULAR PERTURBATION CONTROL FOR COORDINATION OF CONVERTERS IN A FUEL CELL SYSTEM M. Ghanes1 , M

  2. The Effects of Wave Energy Converters on a Monochromatic Wave Climate

    E-Print Network [OSTI]

    Fox-Kemper, Baylor

    available from the National Oceanic and Atmospheric Administration (NOAA). Wave energy converters were converters as well as the availability of energy in the ocean. This study will examine the effects of a wave and mean wave period of wave energy fields. There is tremendous energy potential in the ocean. Solar energy

  3. Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

    DOE Patents [OSTI]

    Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

    2014-09-09T23:59:59.000Z

    A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

  4. Ga{sub x}In{sub 1{minus}x}As thermophotovoltaic converters

    SciTech Connect (OSTI)

    Wanlass, M.W.; Ward, J.S.; Emery, K.A.; Coutts, T.J. [National Renewable Energy Lab., Golden, CO (United States)

    1994-12-31T23:59:59.000Z

    Preliminary research into the development of single-junction Ga{sub x}In{sub 1{minus}x}As thermophotovoltaic (TPV) power converters is reviewed. The devices structures are grown epitaxially on single-crystal InP substrates. Converter band gaps of 0.50--0.74 eV have been considered in accordance with modeling calculations. A 1-sun, AMO efficiency of 12.8% is reported for a lattice-matched, 0.74-eV converter. Converters with lower band gaps are fabricated using lattice-mismatched, compositionally graded structures. Functional TPV converters with good performance characteristics have been demonstrated for band gaps as low as 0.5 eV.

  5. Short-term and creep shear characteristics of a needlepunched thermally locked geosynthetic clay liner

    SciTech Connect (OSTI)

    Siebken, J.R. [National Seal Co., Galesburg, IL (United States). Technical Services; Swan, R.H. Jr.; Yuan, Z. [GeoSyntec Consultants, Atlanta, GA (United States). Soil-Geosynthetic Interaction Testing Lab.

    1997-11-01T23:59:59.000Z

    A series of constant-rate direct shear tests were conducted on a needlepunched thermally locked geosynthetic clay liner (GCL) in accordance with ASTM Test Method for Determining the Coefficient of Soil and Geosynthetic or Geosynthetic and Geosynthetic Friction by the Direct Shear Method (D 5321). The test results demonstrate that the needlepunched thermally locked reinforcing fibers provide substantial short-term shear strength to a GCL. However, there is a growing concern that the long-term shear strength to a GCL. However, there is a growing concern that the long-term shear strength of this type of GCL can be affected due to the potential of creep within the reinforcing fibers under sustained constant loads which occur in the field. An attempt was made to address this concern through an incrementally-loaded creep shear test conducted in a newly developed constant-load (creep) shear testing device. The results of the creep shear test to date show that the GCL has undergone relatively small shear displacements with incremental shear rates decreasing with time within each loading phase.

  6. Analysis of PS-converted wave seismic data in the presence of azimuthal anisotropy 

    E-Print Network [OSTI]

    Liu, Weining

    2014-11-27T23:59:59.000Z

    Shear-wave splitting and azimuthal variations of seismic attributes are two major anisotropic effects induced by vertically-aligned fractures. They both have influences on seismic data processing and interpretation, and ...

  7. SSI response of a typical shear wall structure. Volume 1

    SciTech Connect (OSTI)

    Johnson, J.J.; Schewe, E.C.; Maslenikov, O.R.

    1984-04-01T23:59:59.000Z

    The Simplified Methods project of the US NRC-funded Seismic Safety Margins Research Program (SSMRP) has as its goal the development of a methodology to perform routine seismic probabilistic risk assessments of commercial nuclear power plants. The study reported here develops calibration factors to relate best estimate response to design values accounting for approximations and simplifications in SSI analysis procedures. Nineteen cases were analyzed and in-structure response compared. The structure of interest was a typical shear wall structure. 6 references, 44 figures, 22 tables.

  8. Damping of Neutron Star Shear Modes by Superfluid Friction

    E-Print Network [OSTI]

    P. B. Jones

    2003-01-07T23:59:59.000Z

    The forced motion of superfluid vortices in shear oscillations of rotating solid neutron star matter produces damping of the mode. A simple model of the unpinning and repinning processes is described, with numerical calculations of the consequent energy decay times. These are of the order of 1 s or more for typical anomalous X-ray pulsars but become very short for the general population of radio pulsars. The superfluid friction processes considered here may also be significant for the damping of r-modes in rapidly rotating neutron stars.

  9. Flow of shear induced structure surfactants in porous media

    E-Print Network [OSTI]

    Ramaswamy, Harish B.

    1993-01-01T23:59:59.000Z

    be very useful in extracting oil from heterogeneous formations. In a low permeability region, the Rooding solution would have a lower viscosity snd hence lower resistance, : RODLIKE NONE T]C Fig. 4. Influence of concentration and temperature... measure of the elasticity of the fluid. There is some evidence of a change in the normal stress data at the shear rates at which the viscosity curves indicated the SIS state, though the change is minor as compared with that of the viscosity data. 26...

  10. Electron Trapping in Shear Alfven Waves that Power the Aurora

    SciTech Connect (OSTI)

    Watt, Clare E. J.; Rankin, Robert [University of Alberta, Edmonton, Alberta (Canada)

    2009-01-30T23:59:59.000Z

    Results from 1D Vlasov drift-kinetic plasma simulations reveal how and where auroral electrons are accelerated along Earth's geomagnetic field. In the warm plasma sheet, electrons become trapped in shear Alfven waves, preventing immediate wave damping. As waves move to regions with larger v{sub Te}/v{sub A}, their parallel electric field decreases, and the trapped electrons escape their influence. The resulting electron distribution functions compare favorably with in situ observations, demonstrating for the first time a self-consistent link between Alfven waves and electrons that form aurora.

  11. Transition to Turbulence in Shear-Thinning Fluids

    E-Print Network [OSTI]

    Zhen, Ni

    2014-04-23T23:59:59.000Z

    energy DNS direct numerical simulation RCA right coronary arteries WSS wall shear stress z? vorticity in the z direction ?t time scale of dissipation due to viscosity iu total velocity u total velocity in the x direction v total velocity in the y... viscosity K fluid consistency divided by density n power law index xL domain length in the x direction v yL domain length in the y direction Lz domain length in the z direction D height of the half channel ??? velocity field of the mature...

  12. Wind shear for large wind turbine generators at selected tall tower sites

    SciTech Connect (OSTI)

    Elliott, D.L.

    1984-04-01T23:59:59.000Z

    The objective of the study described in this report is to examine the nature of wind shear profiles and their variability over the height of large horizontal-axis wind turbines and to provide information on wind shear relevant to the design and opertion of large wind turbines. Wind turbine fatigue life and power quality are related through the forcing functions on the blade to the shapes of the wind shear profiles and their fluctuations over the disk of rotation.

  13. Active Vorticity Control in a Shear Flow Using a Flapping Foil

    E-Print Network [OSTI]

    Gopalkrishnan, R.

    1994-01-01T23:59:59.000Z

    It is shown experimentally that free shear flows can be substantially altered through direct control of the large coherent vortices present in the flow.

  14. E-Print Network 3.0 - acoustic-radiation-force-driven shear wave...

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

    of Aceh Besar. The shear-wave seismic surveys were done parallel to standard geoengineering investigations Source: Ecole Polytechnique, Centre de mathmatiques Collection:...

  15. Wave propagation, stress relaxation, and grain-to-grain shearing in saturated, unconsolidated marine sediments

    E-Print Network [OSTI]

    Buckingham, Michael

    Wave propagation, stress relaxation, and grain-to-grain shearing in saturated, unconsolidated in saturated, unconsolidated granular materials, including marine sediments, is developed in this article

  16. Damage to HDPE geomembrane from interface shear over gravelly compacted clay liner

    E-Print Network [OSTI]

    Thielmann, Stuart

    2012-01-01T23:59:59.000Z

    strength of three geosynthetic clay liners,” Journal ofperformance of geosynthetic clay liners under gravel coverShear Machine for Geosynthetic Clay Liners,” Geotechnical

  17. Free magnetohydrodynamic shear layers in the presence of rotation and magnetic field

    SciTech Connect (OSTI)

    Spence, E. J.; Roach, A. H.; Edlund, E. M.; Sloboda, P.; Ji, H. [Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas and Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2012-05-15T23:59:59.000Z

    We present an experimental and numerical study of hydrodynamic and magnetohydrodynamic free shear layers and their stability. We first examine the experimental measurement of globally unstable hydrodynamic shear layers in the presence of rotation and their range of instability. These are compared to numerical simulations, which are used to explain the modification of the shear layer, and thus the critical Rossby number for stability. Magnetic fields are then applied to these scenarios and globally unstable magnetohydrodynamic shear layers generated. These too are compared to numerical simulations showing behavior consistent with the hydrodynamic case and previously reported measurements.

  18. Free MHD Shear Layers In The Presence Of Rotation And Magnetic Field

    SciTech Connect (OSTI)

    E.J. Spence, A.H. Roach, E.M. Edlund, P. Sloboda and H. Ji

    2012-03-20T23:59:59.000Z

    We present an experimental and numerical study of hydrodynamic and magnetohydrodynamic free shear layers and their stability. We first examine the experimental measurement of globally unstable hydrodynamic shear layers in the presence of rotation, and their range of instability. These are compared to numerical simulations, which are used to explain the modification of the shear layer and thus the critical Rossby number for stability. Magnetic fields are then applied to these scenarios, and globally unstable magnetohydrodynamic shear layers generated. These too are compared to numerical simulations, showing behavior consistent with the hydrodynamic case and previously reported measurements.

  19. Traction Drive System for Electric Vehicles, Using Multilevel Converters Juan W. Dixon, Micah Ortzar and Felipe Ros

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    Traction Drive System for Electric Vehicles, Using Multilevel Converters Juan W. Dixon, Micah converters for electric vehicles using multilevel inverters. They are being compared with inverters using. Introduction Power Electronics technologies contribute with important part in the development of electric

  20. E-Print Network 3.0 - ac-dc-ac z-source converter Sample Search...

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

    table... Matrix Converter va vb vc vu vv vw Eq. (5) Virtual Rectifier Control Virtual Inverter Control 9 6 6 3 ACDCAC... Fig. 3. Block diagram of matrix converter controller...

  1. A Generalized Class of Stationary Frame-Current Controllers for Grid-Connected AC–DC Converters

    E-Print Network [OSTI]

    Hwang, J. George

    Within power systems, high-power pulsewidth-modulated ac-dc converters are used in flexible ac transmission systems controllers and for interfacing renewable energy sources to the grid. These converters traditionally ...

  2. Shear exfoliation in liquids : a promising way to produce graphene.

    E-Print Network [OSTI]

    Mougeot, Maxime

    2014-01-01T23:59:59.000Z

    My initial project was to install and test a new spectrometer for the solid state physics group. However, due to a delay in the construction of the new photoluminescence laboratory this project had to be abandoned. Graphene is a one atom thick 2D material that presents remarkable physical properties whose applications are very promising. However, the current means of production present several limitations. They are costly in terms of energy consumption and yields are ridiculously low. Thus, to progress from the laboratory to industrial production it will be necessary to find a method to produce large quantities of defect graphene. In April 2014, a paper \\cite{graphene_shear} came out in \\emph{Nature Material} demonstrating that shear exfoliation in liquids would be a scalable way to produce defect-free grahene. The aim of my project was to test this new method by trying to reproduce some of the results published in this article. It involved the setting up of the experiment, the production of samples and fin...

  3. Numeric simulation of thyristor power converters taking into consideration the firing-circuits and the closed-loop control

    E-Print Network [OSTI]

    Bordry, Frederick; Proudlock, Paul

    1988-01-01T23:59:59.000Z

    Numeric simulation of thyristor power converters taking into consideration the firing-circuits and the closed-loop control

  4. Analysis and design of a saturable reactor assisted soft-switching full-bridge dc-dc converter

    SciTech Connect (OSTI)

    Hamada, Satoshi (Sansha Electric Manufacturing Co., Ltd., Osaka (Japan)); Nakaoka, Mutsuo (Kobe Univ. (Japan). Dept. of Electrical and Electronics Engineering)

    1994-05-01T23:59:59.000Z

    Analysis and design considerations for a saturable reactor assisted soft-switching full-bridge dc-dc converter are presented. The converter has advantages such as low switching losses with no substantial increase in conduction losses, wide load range, and constant frequency operation. To show how to utilize the analysis results, a 350-W, 500-kHz converter is chosen as a design example. The results are verified experimentally on a prototype converter.

  5. A High Efficiency DC-DC Converter Topology Suitable for Distributed Large Commercial and Utility Scale PV Systems

    SciTech Connect (OSTI)

    Mohammed S. Agamy; Maja Harfman-Todorovic; Ahmed Elasser; Robert L. Steigerwald; Juan A. Sabate; Song Chi; Adam J. McCann; Li Zhang; Frank Mueller

    2012-09-01T23:59:59.000Z

    In this paper a DC-DC power converter for distributed photovoltaic plant architectures is presented. The proposed converter has the advantages of simplicity, high efficiency, and low cost. High efficiency is achieved by having a portion of the input PV power directly fed forward to the output without being processed by the converter. The operation of this converter also allows for a simplified maximum power point tracker design using fewer measurements

  6. MULTILEVEL INVERTER, BASED ON MULTI-STAGE CONNECTION OF THREE-LEVEL CONVERTERS, SCALED IN POWER OF THREE.

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    MULTILEVEL INVERTER, BASED ON MULTI-STAGE CONNECTION OF THREE-LEVEL CONVERTERS, SCALED IN POWER. #12;MULTILEVEL INVERTER, BASED ON MULTI-STAGE CONNECTION OF THREE-LEVEL CONVERTERS, SCALED IN POWER, Concepción, Chile ABSTRACT A multi-stage inverter using three-state converters is being analyzed

  7. A Virtual DSP System for Design Instruction of Power Converters AA.. KKeeyyhhaannii aanndd MM.. NN.. MMaarrwwaallii GGeerraalldd BBaauummggaarrttnneerr

    E-Print Network [OSTI]

    Baumgartner, Gerald

    as a case study for the development of the testbed. The resonant power converters provide efficient electric `hard' switching power converters, a resonant converter utilizes a controlled series or parallel LC substantially reduce the switching losses occurred in the power transfer process Despite their attractiveness

  8. Design optimization methodology for power converters based on global energy requirement criteria. Application to a DC-DC flyback structure

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    for power electronic converters according to the Global Energy Requirement (GER) criterion, i.e. the primary-design converters in order to take its environmental impacts (here, only its global primary energy consumptionDesign optimization methodology for power converters based on global energy requirement criteria

  9. Under U.S.-Russia Partnership, Final Shipment of Fuel Converted...

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

    U.S.-Russia Partnership, Final Shipment of Fuel Converted From 20,000 Russian Nuclear Warheads Arrives in United States and Will Be Used for U.S. Electricity Under U.S.-Russia...

  10. Mixed ionic and electronic conducting electrode studies for an alkali metal thermal to electric converter

    E-Print Network [OSTI]

    Guo, Yuyan

    2009-05-15T23:59:59.000Z

    This research focuses on preparation, kinetics, and performance studies of mixed ionic and electronic conducting electrodes (MIEE) applied in an alkali metal thermal to electric converter (AMTEC). Two types of MIEE, metal/sodium titanate and metal...

  11. Request for Information Regarding a Proposed Funding Opportunity for Administration of the Wave Energy Converter Prize

    Broader source: Energy.gov [DOE]

    This announcement is intended to serve as a Notice of Intent of the upcoming Funding Opportunity Announcement (FOA) regarding Administration of the Wave Energy Converter (WEC) Prize and Request for Information.

  12. Request for Information Regarding a Proposed Funding Opportunity for Administration of the Wave Energy Converter Prize

    Broader source: Energy.gov [DOE]

    This announcement is intended to serve as a Notice of Intent of the upcoming Funding Opportunity Announcement (FOA) regarding Administration of the Wave Energy Converter (WEC) Prize and Request for Information to solicit information regarding pote

  13. Research Projects to Convert Captured CO2 Emissions to Useful Products

    Broader source: Energy.gov [DOE]

    Research to help find ways of converting into useful products CO2 captured from emissions of power plants and industrial facilities will be conducted by six projects announced today by the U.S. Department of Energy.

  14. Effect of a nonlinear power take off on a wave energy converter 

    E-Print Network [OSTI]

    Bailey, Helen Louise

    2011-11-22T23:59:59.000Z

    This thesis is titled The influence of a nonlinear Power Take Off on a Wave Energy Converter. It looks at the effect that having a nonlinear Power Take Off (PTO) has on an inertial referenced, slack moored, point absorber, ...

  15. Quantification of the influence of directional sea state parameters over the performances of wave energy converters 

    E-Print Network [OSTI]

    Pascal, Remy Claude Rene

    2012-11-29T23:59:59.000Z

    Accurate predictions of the annual energy yield from wave energy converters are essential to the development of the wave industry. The current method based on power matrices uses only a small part of the data available ...

  16. Generic and Unified Model of Switched Capacitor Converters Sam Ben-Yaakov

    E-Print Network [OSTI]

    Capacitor Converters (SCC) suffer from a fundamental power loss deficiency which makes their use in some applications prohibitive. The power loss is due to the inherent energy dissipation when a capacitor is charged

  17. Area Efficient D/A Converters For Accurate DC Operation Brandon Royce Greenley

    E-Print Network [OSTI]

    Moon, Un-Ku

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 6.2 Mismatch Modeling For Area Optimization . . . . . . . . . . . . . . . . . . . . . . . 51 6Area Efficient D/A Converters For Accurate DC Operation by Brandon Royce Greenley A THESIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 5.1 Measurement Setup

  18. Progress on Converting a NIF Quad to Eight, Petawatt Beams for Advanced Radiography

    SciTech Connect (OSTI)

    Crane, J K

    2009-10-19T23:59:59.000Z

    We are converting a quad of NIF beamlines into eight, short-pulse (1-50 ps), petawatt-class beams for advanced radiography and fast ignition experiments. This paper describes progress toward completing this project.

  19. A resonant load circuit to develop electrical power transfer of thermionic converters

    SciTech Connect (OSTI)

    Perez, G.; Estrada, C.A.; Jimenez, A.E.

    1998-07-01T23:59:59.000Z

    Low internal impedance of thermionic converters requires a low impedance load in the DC mode to obtain optimal power transfer. An internal resistance near 0.1 W for thermionic converters is common. According to the maximum power theorem [Desoer,1969], a similar magnitude for the resistance load must be fixed. Due to temperature changes, the internal plasma resistance and the resistance of the leads is modified [Houston,1959], for this reason, it is difficult to maintain maximum power transfer to the load. This paper presents a resonant load circuit for thermionic converters in the AC mode, to develop impedance coupling. The circuit employs an electrical transformer and positive feedback; by this way, oscillations are themselves maintained. It is used an electrical circuit model [Perez et al, 1997], to simulate the electrical behavior of the thermionic converter.

  20. Fabrication and Testing of Full-Length Single-Cell Externally Fueled Converters for Thermionic Reactors

    SciTech Connect (OSTI)

    Schock, Alfred

    1995-08-01T23:59:59.000Z

    Paper presented at the 29th IECEC in Monterey, CA in August 1994. The present paper describes the fabrication and testing of full-length prototypcial converters, both unfueled and fueled, and presents parametric results of electrically heated tests.

  1. Optical Recognition of Converted DNA Nucleotides for Single-Molecule DNA

    E-Print Network [OSTI]

    Optical Recognition of Converted DNA Nucleotides for Single-Molecule DNA Sequencing Using Nanopore among individual nucleotides (nt). The system must be capable of differentiating among the four bases

  2. Department of Mechanical & Nuclear Engineering Spring 2011 Converting Methane into Ethylene

    E-Print Network [OSTI]

    Demirel, Melik C.

    PENNSTATE Department of Mechanical & Nuclear Engineering Spring 2011 Converting Methane catalyst production labs, reactor testing lab, and testing equipment. Team Methane Fuzion was responsible. Temperature of the catalyst was closely monitored in order to prevent catalyst sintering. Testing

  3. The Utilization and Recovery of Energy from Blast Furnaces and Converters

    E-Print Network [OSTI]

    Hegemann, K. R.; Niess, T.; Baare, R. D.

    1979-01-01T23:59:59.000Z

    comprising a gas cleaning unit for dust removal and a turbine for converting the recoverable thermal energy into mechanical and electrical energy. The adjustable annular gap scrubber for separating fine dust also serves as an element for regulating the gas...

  4. Behavioral modeling and digital calibration of pipeline analog to digital converters

    E-Print Network [OSTI]

    Bilhan, Erkan

    2001-01-01T23:59:59.000Z

    This research focuses on digital calibration of pipeline analog to digital converters (ADCs) and also modeling of error sources and design parameters of pipeline ADCs. Modern applications such as communications systems require high resolution ADCs...

  5. A New Integrated Onboard Charger and Accessory Power Converter for Plug-in Electric Vehicles

    SciTech Connect (OSTI)

    Su, Gui-Jia [ORNL; Tang, Lixin [ORNL

    2014-01-01T23:59:59.000Z

    In this paper, a new approach is presented for integrating the function of onboard battery charging into the traction drive system and accessory dc-dc converter of a plug-in electric vehicle (PEV). The idea is to utilize the segmented traction drive system of a PEV as the frond converter of the charging circuit and the transformer and high voltage converter of the 14 V accessory dc-dc converter to form a galvanically isolated onboard charger. Moreover, a control method is presented for suppressing the battery current ripple component of twice the grid frequency with the reduced dc bus capacitor in the segmented inverter. The resultant integrated charger has lower cost, weight, and volume than a standalone charger due to a substantially reduced component count. The proposed integrated charger topology was verified by modeling and experimental results on a 5.8 kW charger prototype.

  6. Fabrication of optical-mode converters for efficient fiber-to-silicon-waveguide couplers

    E-Print Network [OSTI]

    Barreto, Raúl E

    2007-01-01T23:59:59.000Z

    Optical-mode converters are needed to efficiently couple light from an optical fiber to a photonic circuit by matching and transforming the propagating modes. This work is based on a horizontally-tapered coupler, in which ...

  7. Methodology for determining feasibility and cost for converting dredged material to topsoil

    E-Print Network [OSTI]

    Graalum, Sara Jo Ann

    1997-01-01T23:59:59.000Z

    alternatives is to convert dredged material to manufactured soil (artificial topsoil). A limited number of studies have been conducted by the United States Army Corps of Engineers (USACE) Waterways Experiment Station in conjunction with local USACE Districts...

  8. System demonstration of an optically-sampled, wavelength-demultiplexed photonic analog-to-digital converter

    E-Print Network [OSTI]

    Peng, Michael Yung

    2011-01-01T23:59:59.000Z

    The performance of electronic analog-to-digital converters (ADCs) at high sampling rates is fundamentally limited by the timing jitter of electronic clocks. To circumvent this limitation, one method is to exploit the ...

  9. High efficiency resonant dc/dc converter for solar power applications

    E-Print Network [OSTI]

    Inam, Wardah

    2013-01-01T23:59:59.000Z

    This thesis presents a new topology for a high efficiency dc/dc resonant power converter that utilizes a resistance compression network to provide simultaneous zero voltage switching and near zero current switching across ...

  10. Design, Modeling, and Control of Three-Port Converters for Solar Power Applications.

    E-Print Network [OSTI]

    Reese, Justin M

    2007-01-01T23:59:59.000Z

    ??This paper describes the results of research into multi-port converter design and control, specifically a pair of three-port topologies based on the half-bridge and full-bridge… (more)

  11. A Three-Phase Bidirectional DC-DC Converter for Automotive Applications

    SciTech Connect (OSTI)

    Su, Gui-Jia [ORNL; Tang, Lixin [ORNL

    2008-01-01T23:59:59.000Z

    This paper presents a three-phase soft-switching, bidirectional dc-dc converter for high-power automotive applications. The converter employs dual three-phase active bridges and operates with a novel asymmetrical but fixed duty cycle for the top and bottom switches of each phase leg. Simulation and experimental data on a 6-kW prototype are included to verify the novel operating and power flow control principles.

  12. High-Power Converters and AC Drives IEEE PESC2005 Tutorial

    E-Print Network [OSTI]

    Wu, Bin

    @ee.ryerson.ca http://www.ee.ryerson.ca/~bwu/ 2 High-Power Converters and AC Drives 1. Introduction 2. Cascaded H-Bridge Drives · High-Power Semiconductor Devices High-Power Converters and AC Drives Bin Wu 4High · Multilevel Voltage Source Inverters N dC Cascaded H-bridge (CHB) Inverter dC Two Level Inverter dC Flying

  13. Identification of sorghum midge (Diptera: Cecidomyiidae): resistant lines among converted exotic sorghum

    E-Print Network [OSTI]

    Ali, Ali El Badawi

    1986-01-01T23:59:59.000Z

    1986) Ali E 1 Badawi Ali, B. S. , University of Khartoum, Khartoum, Sudan. Chairman of advisory cotmnittee: Dr. george L. Teetes. In an attempt to identify additional sorghum lines tant to so gh Sdg, t t ~ rtnt ~ ~so htd t (C q Stlott), field... converted exotic sorghum lines were obtained from Dr. Gary C. Peterson, Sorghum Breeder at the Texas A8 M University Agricultural Research and Extension Center at Lubbock. The converted exotic sorghum lines are identical to the tall, photo...

  14. An 8-bit current mode ripple folding analog to digital converter

    E-Print Network [OSTI]

    Dinc, Huseyin

    2012-06-07T23:59:59.000Z

    . 3. 4 Noise IV. RIPPLE FOLDING TECHNIQUE 1. Conceptual Description of Ripple Folding. . 2. Topologies to Implement Minimum-Maximum Detection. . . . . 2. 1 The Diode Bridge 2. 2 Bipolar Realization. . 2. 3 CMOS Realization 2. 4 Switched Current... single pole system. 23 Noise bandwidth. 24 Traditional folding A/D converter 25 (a) Conceptual ripple lolding A/D converter. . . . . . 21 23 23 . . . 30 . . . . . . 35 36 . . . . . 37 . . . 41 FIGURE Page 26 27 28 Diode bridge...

  15. Direct connection of series self-excited generators and HVDC converters

    SciTech Connect (OSTI)

    Arrillaga, J.; Macdonald, S.J.; Watson, N.R.; Watson, S. (Univ. Canterbury, Christchurch (New Zealand))

    1993-10-01T23:59:59.000Z

    An alternative and simpler solution is proposed for the direct connection of generators to HVdc converters. The generator exciter windings are connected in series with the output of the HVdc converter and take the place of the conventional smoothing reactor. Existing steady state and time domain simulation programs are modified to represent the behavior of the series direct connection scheme. It is shown that series excitation extends naturally the power transmission capability and permits fast fault clearances.

  16. Evaluation of Simplified Methods for Estimating Shear Capacity Using JNES/NUPEC Low-Rise Concrete Shear Wall Cyclic Test Data.

    SciTech Connect (OSTI)

    Nie,J.; Braverman, J.; Hofmayer, C.; Ali, S.

    2008-06-01T23:59:59.000Z

    The simplified methods in current codes for determining the shear capacity of reinforced concrete shear walls had mostly been validated using the test results of single-element shear walls. Recently available JNES/NUPEC test data of reinforced concrete shear walls under multi-directional cyclic loadings provided a unique opportunity to investigate the adequacy of the simplified methods for use in situations with strong interaction effects. A total of 11 test specimens with aspect ratios between 0.47 and 0.87 have been used in the assessment. Two simplified methods from the ACI 349-01 standard [1] and one from the ASCE 43-05 standard [2] have been evaluated. This paper also presents the development of an adjustment factor to consider the aspect ratio and the development of two approaches to consider interaction effects for one of the simplified methods. It concludes with the insights on the applicability of the code methods when interaction effects exist.

  17. Stirling converters for space dynamic power concepts with 2 to 130 W{sub e} output

    SciTech Connect (OSTI)

    Ross, B.A. [Stirling Technology Co., Richland, WA (United States)

    1995-12-31T23:59:59.000Z

    Three innovative Stirling converter concepts are described. Two concepts are based on Pluto Fast Flyby (PFF) mission requirements, where two General Purpose Heat Source (GPHS) modules provide the thermal input. The first concept (PFF2) considers a power system with two opposed Stirling converters; the second concept (PFF4) considers four opposed Stirling converters. For both concepts the Stirling converters are designed to vary their power production capability to compensate for the failure of one Stirling converter. While the net thermal efficiency of PFF4 is a few percentage points lower than PFF2, the total Stirling converter mass of PFF4 is half that for PFF2. The third concept (ITTI) is designed to supply 2 watts of power for weather stations on the Martian surface. The predicted thermal performance of the ITTI is low compared to PFF2 and PFF4, yet the ITTI concept offers significant advantages compared to currently available power systems at the 2-watt power level. All three concepts are based on long-life technology demonstrated by an 11-watt output Stirling generator that as of March 1995 has accumulated over 15,000 operating hours without maintenance.

  18. Close-spaced thermionic converters with active spacing control and heat-pipe isothermal emitters

    SciTech Connect (OSTI)

    Fitzpatrick, G.O.; Koester, J.K.; Chang, J.; Britt, E.J.; McVey, J.B. [Space Power, Inc., San Jose, CA (United States)

    1996-12-31T23:59:59.000Z

    Thermionic converters with interelectrode gaps smaller than 10 microns are capable of substantial performance improvements over conventional ignited mode diodes. Previous devices which have demonstrated operation at such small gaps have done so at low power densities and emitter temperatures. Higher power operation requires overcoming two primary design issues: thermal distortion of the emitter due to temperature gradients and degradation of the in-gap spacers at higher emitter temperatures. This work describes two innovations for solution of these issues. The issue of thermal distortion was addressed by an isothermal emitter incorporating a heat-pipe into its structure. Such a heat-pipe emitter, with a single-crystal emitting surface, was fabricated and characterized. Finite-element computational modeling was used to analyze its distortion with an applied heat flux. The calculations suggested that thermal distortion would be significantly reduced as compared with a solid emitter. Ongoing work and preliminary experimental results are described for a system of active interelectrode gap control. In the present design an integral transducer determines the interelectrode gap of the converter. Initial designs for spacing actuators and their required cesium vapor seals are discussed. A novel hot-shell converter design incorporating active spacing control and low-temperature seals is presented. A converter incorporating the above features would be capable of near ideal-converter performance at high power densities. In addition, active spacing control can potentially completely eliminate short-circuit failures in thermionic converter systems.

  19. Wave-current interaction in strongly sheared mean flows Zhifei Dong and James T. Kirby

    E-Print Network [OSTI]

    Kirby, James T.

    Wave-current interaction in strongly sheared mean flows Zhifei Dong and James T. Kirby Center@udel.edu Abstract We describe a framework for wave-current interaction theory for small-amplitude surface gravity waves propagating on the strongly sheared mean flows. Using a multiple-scale perturbation method, we

  20. Ris-PhD-Report Accounting for the speed shear in wind

    E-Print Network [OSTI]

    Risø-PhD-Report Accounting for the speed shear in wind turbine power performance measurement Rozenn for the speed shear in wind turbine power performance measurement Division: Wind Energy Division Abstract: The power curve of a wind turbine is the primary char- acteristic of the machine as it is the basis

  1. Nonlinear shear wave interaction at a frictional interface: Energy dissipation and generation of harmonics

    E-Print Network [OSTI]

    Norris, Andrew

    Nonlinear shear wave interaction at a frictional interface: Energy dissipation and generation solids, brought into frictional contact by remote normal compression. A shear wave, either time har the partition of energy resulting from a time harmonic obliquely incident plane SH wave reflected and refracted

  2. Melt segregation under compaction and shear channelling: Application to granitic magma segregation in a continental crust

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Melt segregation under compaction and shear channelling: Application to granitic magma segregation in a mush submitted to both compaction and shear. It applies to a granitic melt imbedded within of melt to about 20 % in total to be extracted from the matrix. Abridged title Granitic melt segregation

  3. How Does the Eye Warm? Part II: Sensitivity to Vertical Wind Shear and a Trajectory Analysis

    E-Print Network [OSTI]

    How Does the Eye Warm? Part II: Sensitivity to Vertical Wind Shear and a Trajectory Analysis DANIEL of vertical wind shear on the structure of warming and descent in the eye; results are compared with the no environment, time-averaged eye descent is maximized at 12­13-km height. Warming is not generally maximized

  4. Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear

    DOE Patents [OSTI]

    Westerfield, C.L.; Morris, J.S.; Agnew, S.F.

    1997-01-14T23:59:59.000Z

    Diamond anvil cell is described for spectroscopic investigation of materials at high temperature, high pressure and shear. A cell is described which, in combination with Fourier transform IR spectroscopy, permits the spectroscopic investigation of boundary layers under conditions of high temperature, high pressure and shear. 4 figs.

  5. ORIGINAL ARTICLE Shear strength of municipal solid waste for stability analyses

    E-Print Network [OSTI]

    ORIGINAL ARTICLE Shear strength of municipal solid waste for stability analyses Timothy D. Stark � solid waste (MSW) using the back analysis of failed waste slopes as well as field and laboratory test analyses. Keywords Municipal solid waste Á Shear strength Á Slope stability Á Landfill Introduction

  6. EFFECT OF SHEAR ON THE RHEOLOGY AND CRYSTALLISATION OF PALM OIL

    E-Print Network [OSTI]

    Boyer, Edmond

    1 EFFECT OF SHEAR ON THE RHEOLOGY AND CRYSTALLISATION OF PALM OIL E. TARABUKINA 1,3 , F. JEGO 2-(0)4-92-38-97-52 E-mail: edith.disdier@mines-paristech.fr Short version of title: Crystallisation of palm oil under;2 ABSTRACT: This paper reports on the impact of shear on crystallisation upon cooling of palm oil. Samples

  7. PLASTICITY OF DAMAGED SOLIDS AND SHEAR BAND LOCALIZATION MARIA K.DUSZEK and PIOTR PERZYNA

    E-Print Network [OSTI]

    Boyer, Edmond

    694 PLASTICITY OF DAMAGED SOLIDS AND SHEAR BAND LOCALIZATION MARIA K.DUSZEK and PIOTR PERZYNA of shear band localization conditions for finite elastic-plastic rate independent deformations of damaged for elastic-plastic solids when iso- tropic and kinematic hardening effects and micro-damage process are taken

  8. Fractal Shear Bands at Elastic-Plastic Transitions in Random Mohr-Coulomb Materials

    E-Print Network [OSTI]

    Ostoja-Starzewski, Martin

    Fractal Shear Bands at Elastic-Plastic Transitions in Random Mohr-Coulomb Materials J. Li, A.M.ASCE1 ; and M. Ostoja-Starzewski, M.ASCE2 Abstract: This paper studies fractal patterns forming of plastic grains (i.e., a shear-band system) is always a monotonically growing fractal under increasing

  9. Discussion of "Analysis of a Large Database of GCL Internal Shear

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    .edu The authors have presented an extensive and valuable study on the internal shear strength of geosynthetic clay liners GCLs . The discusser has also performed extensive tests of these materials and can comment for quality geosynthetic shear testing. Some of the test data in the authors' database are also found

  10. Transient Shear Banding in a Simple Yield Stress Fluid Thibaut Divoux,1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    region with a vanishing local shear rate loc = 0 and a fluidized region sheared at loc = c. Besides, var that somewhat blur the above distinction. First, non-thixotropic nonad- hesive emulsions, for which magnetic resonance velocime- try coupled to wide-gap rheology shows simple yielding behavior [12], were found

  11. Electron acceleration by a plasma wave in a sheared magnetic field K. P. Singha)

    E-Print Network [OSTI]

    Singh, Kunwar Pal

    Electron acceleration by a plasma wave in a sheared magnetic field K. P. Singha) and V. L. Gupta Department of Electronic Science, University of Delhi, New Delhi-110021, India Lalita Bhasin and V. K, the acceleration of electrons by a plasma wave, in the presence of a sheared magnetic field a slab model

  12. Shear flow generation by drift waves revisited P. N. Guzdar and R. G. Kleva

    E-Print Network [OSTI]

    Rubloff, Gary W.

    Shear flow generation by drift waves revisited P. N. Guzdar and R. G. Kleva Institute for Plasma 2000 The generation of shear flow by drift waves is an important area of investigation. In a recent paper Chen et al., Phys. Plasmas 7, 3129 2000 an elegant formalism was developed for the generation

  13. High-frequency shear-horizontal surface acoustic wave sensor

    DOE Patents [OSTI]

    Branch, Darren W

    2013-05-07T23:59:59.000Z

    A Love wave sensor uses a single-phase unidirectional interdigital transducer (IDT) on a piezoelectric substrate for leaky surface acoustic wave generation. The IDT design minimizes propagation losses, bulk wave interferences, provides a highly linear phase response, and eliminates the need for impedance matching. As an example, a high frequency (.about.300-400 MHz) surface acoustic wave (SAW) transducer enables efficient excitation of shear-horizontal waves on 36.degree. Y-cut lithium tantalate (LTO) giving a highly linear phase response (2.8.degree. P-P). The sensor has the ability to detect at the pg/mm.sup.2 level and can perform multi-analyte detection in real-time. The sensor can be used for rapid autonomous detection of pathogenic microorganisms and bioagents by field deployable platforms.

  14. High-frequency shear-horizontal surface acoustic wave sensor

    SciTech Connect (OSTI)

    Branch, Darren W

    2014-03-11T23:59:59.000Z

    A Love wave sensor uses a single-phase unidirectional interdigital transducer (IDT) on a piezoelectric substrate for leaky surface acoustic wave generation. The IDT design minimizes propagation losses, bulk wave interferences, provides a highly linear phase response, and eliminates the need for impedance matching. As an example, a high frequency (.about.300-400 MHz) surface acoustic wave (SAW) transducer enables efficient excitation of shear-horizontal waves on 36.degree. Y-cut lithium tantalate (LTO) giving a highly linear phase response (2.8.degree. P-P). The sensor has the ability to detect at the pg/mm.sup.2 level and can perform multi-analyte detection in real-time. The sensor can be used for rapid autonomous detection of pathogenic microorganisms and bioagents by field deployable platforms.

  15. A current driven electromagnetic mode in sheared and toroidal configurations

    E-Print Network [OSTI]

    Pusztai, István; Parra, Felix I; Barnes, Michael

    2013-01-01T23:59:59.000Z

    The induced electric field in a tokamak drives a parallel electron current flow. In an inhomogeneous, finite beta plasma, when this electron flow is comparable to the ion thermal speed, the Alfven mode wave solutions of the electromagnetic gyrokinetic equation can become nearly purely growing kink modes. Using the new "low-flow" version of the gyrokinetic code GS2 developed for momentum transport studies [Barnes et al 2013 Phys. Rev. Lett. 111, 055005], we are able to model the effect of the induced parallel electric field on the electron distribution to study the destabilizing influence of current on stability. We identify high mode number kink modes in GS2 simulations and make comparisons to analytical theory in sheared magnetic geometry. We demonstrate reassuring agreement with analytical results both in terms of parametric dependences of mode frequencies and growth rates, and regarding the radial mode structure.

  16. New charged shear-free relativistic models with heat flux

    E-Print Network [OSTI]

    Y. Nyonyi; S. D. Maharaj; K. S. Govinder

    2014-12-21T23:59:59.000Z

    We study shear-free spherically symmetric relativistic gravitating fluids with heat flow and electric charge. The solution to the Einstein-Maxwell system is governed by the generalised pressure isotropy condition which contains a contribution from the electric field. This condition is a highly nonlinear partial differential equation. We analyse this master equation using Lie's group theoretic approach. The Lie symmetry generators that leave the equation invariant are found. The first generator is independent of the electromagnetic field. The second generator depends critically on the form of the charge, which is determined explicitly in general. We provide exact solutions to the gravitational potentials using the symmetries admitted by the equation. Our new exact solutions contain earlier results without charge. We show that other charged solutions, related to the Lie symmetries, may be generated using the algorithm of Deng. This leads to new classes of charged Deng models which are generalisations of conformally flat metrics.

  17. Inflationary perturbations in anisotropic, shear-free universes

    SciTech Connect (OSTI)

    Pereira, Thiago S. [Departamento de Física, Universidade Estadual de Londrina, 86051-990, Londrina, Paraná (Brazil); Carneiro, Saulo [Instituto de Física, Universidade Federal da Bahia, 40210-340, Salvador, Bahia (Brazil); Marugan, Guillermo A. Mena, E-mail: tspereira@uel.br, E-mail: saulo.carneiro@pq.cnpq.br, E-mail: mena@iem.cfmac.csic.es [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid (Spain)

    2012-05-01T23:59:59.000Z

    In this work, the linear and gauge-invariant theory of cosmological perturbations in a class of anisotropic and shear-free spacetimes is developed. After constructing an explicit set of complete eigenfunctions in terms of which perturbations can be expanded, we identify the effective degrees of freedom during a generic slow-roll inflationary phase. These correspond to the anisotropic equivalent of the standard Mukhanov-Sasaki variables. The associated equations of motion present a remarkable resemblance to those found in perturbed Friedmann-Robertson-Walker spacetimes with curvature, apart from the spectrum of the Laplacian, which exhibits the characteristic frequencies of the underlying geometry. In particular, it is found that the perturbations cannot develop arbitrarily large super-Hubble modes.

  18. Density waves in the shearing sheet III. Disc heating

    E-Print Network [OSTI]

    B. Fuchs

    2001-04-25T23:59:59.000Z

    The problem of dynamical heating of galactic discs by spiral density waves is discussed using the shearing sheet model. The secular evolution of the disc is described quantitatively by a diffusion equation for the distribution function of stars in the space spanned by integrals of motion of the stars, in particular the radial action integral and an integral related to the angular momentum. Specifically, disc heating by a succession of transient, `swing amplified' density waves is studied. It is shown that such density waves lead predominantly to diffusion of stars in radial action space. The stochastical changes of angular momenta of the stars and the corresponding stochastic changes of the guiding centre radii of the stellar orbits induced by this process are much smaller.

  19. Mixing and segregation rates in sheared granular materials

    E-Print Network [OSTI]

    Laura A. Golick; Karen E. Daniels

    2009-06-17T23:59:59.000Z

    The size-segregation of granular materials, a process colloquially known as the Brazil Nut Effect, has generally been thought to proceed faster the greater the size difference of the particles. We experimentally investigate sheared bidisperse granular materials as a function of the size ratio of the two species, and find that the mixing rate at low confining pressure behaves as expected from percolation-based arguments. However, we also observe an anomalous effect for the re-segregation rates, wherein particles of both dissimilar and similar sizes segregate more slowly than intermediate particle size ratios. Combined with the fact that increasing the confining pressure significantly suppresses both mixing and segregation rates of particles of dissimilar size, we propose that the anomalous behavior may be attributed to a species-dependent distribution of forces within the system.

  20. Hydrodynamic granular segregation induced by boundary heating and shear

    E-Print Network [OSTI]

    Francisco Vega Reyes; Vicente Garzó; Nagi Khalil

    2014-04-28T23:59:59.000Z

    Segregation induced by a thermal gradient of an impurity in a driven low-density granular gas is studied. The system is enclosed between two parallel walls from which we input thermal energy to the gas. We study here steady states occurring when the inelastic cooling is exactly balanced by some external energy input (stochastic force or viscous heating), resulting in a uniform heat flux. A segregation criterion based on Navier-Stokes granular hydrodynamics is written in terms of the tracer diffusion transport coefficients, whose dependence on the parameters of the system (masses, sizes and coefficients of restitution) is explicitly determined from a solution of the inelastic Boltzmann equation. The theoretical predictions are validated by means of Monte Carlo and molecular dynamics simulations, showing that Navier-Stokes hydrodynamics produces accurate segregation criteria even under strong shearing and/or inelasticity.

  1. Speed-up of combustion fronts in shear flows

    E-Print Network [OSTI]

    Hamel, Francois

    2011-01-01T23:59:59.000Z

    This paper is concerned with the analysis of speed-up of reaction-diffusion-advection traveling fronts in infinite cylinders with periodic boundary conditions. The advection is a shear flow with a large amplitude and the reaction is nonnegative, with either positive or zero ignition temperature. The unique or minimal speeds of the traveling fronts are proved to be asymptotically linear in the flow amplitude as the latter goes to infinity, solving an open problem from \\cite{b}. The asymptotic growth rate is characterized explicitly as the unique or minimal speed of traveling fronts for a limiting degenerate problem, and the convergence of the regular traveling fronts to the degenerate ones is proved for positive ignition temperatures under an additional H{\\"{o}}rmander-type condition on the flow.

  2. Subcritical turbulent transition in rotating and curved shear flows

    E-Print Network [OSTI]

    P-Y. Longaretti; O. Dauchot

    2005-09-19T23:59:59.000Z

    The effects of global flow rotation and curvature on the subcritical transition to turbulence in shear flows are examined. The relevant time-scales of the problem are identified by a decomposition of the flow into a laminar and a deviation from laminar parts, which is performed for rotating plane Couette and Taylor-Couette flows. The usefulness and relevance of this procedure are discussed at the same time. By comparing the self-sustaining process time-scale to the time-scales previously identified, an interpretation is brought to light for the behavior of the transition Reynolds number with the rotation number and relative gap width in the whole neighborhood (in parameter space) of the non-rotating plane Couette flow covered by the available data.

  3. High spin spectroscopy and shears mechanism in {sup 107}In

    SciTech Connect (OSTI)

    Negi, D.; Mohanto, G.; Kumar, R.; Singh, R. P.; Muralithar, S.; Bhowmik, R. K. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Trivedi, T. [Department of Physics, University of Allahabad, Allahabad 211002 (India); Dhal, A. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Department of Physics, Banaras Hindu University, Varanasi 221005 (India); Kumar, S.; Kumar, V. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Roy, S. [S.N. Bose National Centre for Basic Sciences, Block JD, Sector III, Kolkata 700098 (India); Raju, M. K. [Department of Nuclear Physics, Andhra University, Visakhapatnam 530003 (India); Appannababu, S. [Department of Physics, M.S. University of Baroda, Vadodara 390002 (India); Kaur, J.; Bhati, A. K. [Department of Physics, Punjab University, Chandigarh 160014 (India); Sinha, R. K. [Department of Physics, Banaras Hindu University, Varanasi 221005 (India); Pancholi, S. C. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2010-05-15T23:59:59.000Z

    High spin states of {sup 107}In have been investigated using the reaction {sup 94}Mo({sup 16}O,p2n){sup 107}In at a beam energy of 70 MeV. A total of 62 new gamma transitions have been placed in the level scheme and several DELTAI=1 sequences and one DELTAI=2 sequence have been found. Lifetime measurements using the Doppler-shift attenuation method (DSAM) have been carried out for band states of DELTAI=1 and DELTAI=2. A decreasing trend of B(M1) strengths with increasing spin deduced for the DELTAI=1 band indicates the presence of a shears mechanism. The experimental data for this band are compared with the tilted axis cranking (TAC) calculations. The DELTAI=2 band has been found to be a deformed band with beta{sub 2}approx0.2.

  4. Shear Transformation Zones: State Determined or Protocol Dependent?

    E-Print Network [OSTI]

    Oleg Gendelman; Prabhat K. Jaiswal; Itamar Procaccia; Bhaskar Sen Gupta; Jacques Zylberg

    2014-08-18T23:59:59.000Z

    The concept of a Shear Transformation Zone (STZ) refers to a region in an amorphous solid that undergoes a plastic event when the material is put under an external mechanical load. An important question that had accompanied the development of the theory of plasticity in amorphous solids for many years now is whether an STZ is a {\\em region} existing in the material (which can be predicted by analyzing the unloaded material), or is it an {\\em event} that depends on the loading protocol (i.e., the event cannot be predicted without following the protocol itself). In this Letter we present strong evidence that the latter is the case. Infinitesimal changes of protocol result in macroscopically big jumps in the positions of plastic events, meaning that these can never be predicted from considering the unloaded material.

  5. Constraining primordial magnetic fields with future cosmic shear surveys

    SciTech Connect (OSTI)

    Fedeli, C. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Moscardini, L., E-mail: cosimo.fedeli@astro.ufl.edu, E-mail: lauro.moscardini@unibo.it [Dipartimento di Astronomia, Università di Bologna, Via Ranzani 1, 40127 Bologna (Italy)

    2012-11-01T23:59:59.000Z

    The origin of astrophysical magnetic fields observed in galaxies and clusters of galaxies is still unclear. One possibility is that primordial magnetic fields generated in the early Universe provide seeds that grow through compression and turbulence during structure formation. A cosmological magnetic field present prior to recombination would produce substantial matter clustering at intermediate/small scales, on top of the standard inflationary power spectrum. In this work we study the effect of this alteration on one particular cosmological observable, cosmic shear. We adopt the semi-analytic halo model in order to describe the non-linear clustering of matter, and feed it with the altered mass variance induced by primordial magnetic fields. We find that the convergence power spectrum is, as expected, substantially enhanced at intermediate/small angular scales, with the exact amplitude of the enhancement depending on the magnitude and power-law index of the magnetic field power spectrum. Specifically, for a fixed amplitude, the effect of magnetic fields is larger for larger spectral indices. We use the predicted statistical errors for a future wide-field cosmic shear survey, on the model of the ESA Cosmic Vision mission Euclid, in order to forecast constraints on the amplitude of primordial magnetic fields as a function of the spectral index. We find that the amplitude will be constrained at the level of ? 0.1 nG for n{sub B} ? ?3, and at the level of ? 10{sup ?7} nG for n{sub B} ? 3. The latter is at the same level of lower bounds coming from the secondary emission of gamma-ray sources, implying that for high spectral indices Euclid will certainly be able to detect primordial magnetic fields, if they exist. The present study shows how large-scale structure surveys can be used for both understanding the origins of astrophysical magnetic fields and shedding new light on the physics of the pre-recombination Universe.

  6. Hybrid shearing and phase-shifting point diffraction interferometer

    DOE Patents [OSTI]

    Goldberg, Kenneth Alan; Naulleau, Patrick P.

    2003-06-03T23:59:59.000Z

    A new interferometry configuration combines the strengths of two existing interferometry methods, improving the quality and extending the dynamic range of both. On the same patterned mask, placed near the image-plane of an optical system under test, patterns for phase-shifting point diffraction interferometry and lateral shearing interferometry coexist. The former giving verifiable high accuracy for the measurement of nearly diffraction-limited optical systems. The latter enabling the measurement of optical systems with more than one wave of aberration in the system wavefront. The interferometry configuration is a hybrid shearing and point diffraction interferometer system for testing an optical element that is positioned along an optical path including: a source of electromagnetic energy in the optical path; a first beam splitter that is secured to a device that includes means for maneuvering the first beam splitter in a first position wherein the first beam splitter is in the optical path dividing light from the source into a reference beam and a test beam and in a second position wherein the first beam splitter is outside the optical path: a hybrid mask which includes a first section that defines a test window and at least one reference pinhole and a second section that defines a second beam splitter wherein the hybrid mask is secured to a device that includes means for maneuvering either the first section or the second section into the optical path positioned in an image plane that is created by the optical element, with the proviso that the first section of the hybrid mask is positioned in the optical path when first beam splitter is positioned in the optical path; and a detector positioned after the hybrid mask along the optical path.

  7. FINAL REPORT OF RESEARCH ON CuxS/ (Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS 3/77 - 9/79

    E-Print Network [OSTI]

    Chin, B.L.

    2013-01-01T23:59:59.000Z

    S/(Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS 3/77 - 9/79Research on Photovoltaic Solar Energy Converters CuxSI(Cd~

  8. Fabrication and Testing of Full-Length Single-Cell Externally Fueled Converters for Thermionic Reactors

    SciTech Connect (OSTI)

    Schock, Alfred

    1994-06-01T23:59:59.000Z

    The preceding paper described designs and analyses of thermionic reactors employing full-core-length single-cell converters with their heated emitters located on the outside of their internally cooled collectors, and it presented results of detailed parametric analyses which illustrate the benefits of this unconventional design. The present paper describes the fabrication and testing of full-length prototypical converters, both unfueled and fueled, and presents parametric results of electrically heated tests. The unfueled converter tests demonstrated the practicality of operating such long converters without shorting across a 0.3-mm interelectrode gap. They produced a measured peak output of 751 watts(e) from a single diode and a peak efficiency of 15.4%. The fueled converter tests measured the parametric performance of prototypic UO(subscript 2)-fueled converters designed for subsequent in-pile testing. They employed revolver-shaped tungsten elements with a central emitter hole surrounded by six fuel chambers. The full-length converters were heated by a water-cooled RF-induction coil inside an ion-pumped vacuum chamber. This required development of high-vacuum coaxial RF feedthroughs. In-pile test rules required multiple containment of the UO (subscript 2)-fuel, which complicated the fabrication of the test article and required successful development of techniques for welding tungsten and other refractory components. The test measured a peak power output of 530 watts(e) or 7.1 watts/cm (superscript 2) at an efficiency of 11.5%. There are three copies in the file. Cross-Reference a copy FSC-ESD-217-94-529 in the ESD files with a CID #8574.

  9. Simulation and analysis of Magnetically-Applied Pressure-Shear (MAPS) experiments.

    SciTech Connect (OSTI)

    Haill, Thomas A.; Alexander, C. Scott; Asay, James Russell

    2011-06-01T23:59:59.000Z

    A new experimental technique to measure material shear strength at high pressures has been developed for use on magnetohydrodynamic (MHD) drive pulsed power platforms. The technique is referred to as Magnetically-Applied Pressure-Shear (MAPS). By applying an external static magnetic field to the sample region, the MHD drive directly induces a shear stress wave in addition to the usual longitudinal stress wave. Strength is probed by passing this shear wave through a sample material where the transmissible shear stress is limited to the sample strength. The magnitude of the transmitted shear wave is measured via a transverse velocity interferometry system (VISAR) from which the sample strength is determined. The strength of materials is defined as the ability of a material to sustain deviatoric (shear) stresses. Strength is an important aspect of the response of materials subjected to compression to high pressure. Beyond the elastic response, material strength will govern at what pressure and to what extent a material will plastically deform. The MAPS technique cleverly exploits the property that, for a von Mises yield criterion at a given longitudinal stress, the maximum amplitude shear wave that can be transmitted is limited by the strength at that stress level. Successful fielding of MAPS experiments to measure shear stresses relies upon correct numerical simulation of the experiment. Complex wave interactions among forward and reflected longitudinal and shear waves, as well as the advancing magnetic diffusion front of the MHD drive, can make the design of the experiment complicated. Careful consideration must be given to driver, sample, and anvil materials; to the thicknesses of the driver, sample and anvil layers; as well as to the timing of the interacting waves. This paper will present and analyze the 2D MHD simulations used to design the MAPS experiments. The MAPS experiments are modeled using Sandia's ALEGRA-MHD simulation code. ALEGRA-MHD is an operator-split, multi-physics, multi-material, arbitrary lagrangian-eulerian code developed to model magnetic implosion, ceramic fracture, and electromagnetic launch. We will detail the numerical investigations into MHD shear generation, longitudinal and shear stress coupling, timing of wave interactions, and transmission of shear at material interfaces.

  10. COMPARISON OF WIND AND WIND SHEAR CLIMATOLOGIES DERIVED FROM HIGH-RESOLUTION RADIOSONDES AND THE ECMWF MODEL

    E-Print Network [OSTI]

    Stoffelen, Ad

    COMPARISON OF WIND AND WIND SHEAR CLIMATOLOGIES DERIVED FROM HIGH-RESOLUTION RADIOSONDES wind and its vertical gradient, i.e. wind-shear, is characterized as a function of climate region. For a better representation of the average atmospheric wind and shear and their variabilities, high

  11. Australian Journal of Earth Sciences (1988) 35, 223-230 Shear-zone deformation in the Yackandandah Granite,

    E-Print Network [OSTI]

    Sandiford, Mike

    Granite, northeast Victoria Michael Sandiford, 1 Stuart F. Martin2 and Eric M. Lohe2 lDepartment o mid-Devonian age resulted in the formation ofa ductile shear zone in the granite, termed the Kiewa shear zone. Displacement of granite boundaries and shear-zone fabrics, including excellently developed s

  12. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 14, NO. 5, OCTOBER 2005 1023 Micromachined Thermal Shear-Stress Sensor for

    E-Print Network [OSTI]

    Lin, Qiao

    detection of unmanned aerial vehicles [4]­[6]. The wall shear stress can be determined directly using Shear-Stress Sensor for Underwater Applications Yong Xu, Member, IEEE, Qiao Lin, Member, IEEE, Guoyu Lin Abstract--This paper reports the development of microma- chined thermal shear-stress sensors for underwater

  13. Local convertibility and the quantum simulation of edge states in many-body systems

    E-Print Network [OSTI]

    Fabio Franchini; Jian Cui; Luigi Amico; Heng Fan; Mile Gu; Vladimir E. Korepin; Leong Chuan Kwek; Vlatko Vedral

    2014-09-23T23:59:59.000Z

    In some many-body systems, certain ground state entanglement (Renyi) entropies increase even as the correlation length decreases. This entanglement non-monotonicity is a potential indicator of non-classicality. In this work we demonstrate that such a phenomenon, known as non-local convertibility, is due to the edge state (de)construction occurring in the system. To this end, we employ the example of the Ising chain, displaying an order-disorder quantum phase transitions. Employing both analytical and numerical methods, we compute entanglement entropies for various system bipartitions (A|B) and consider ground states with and without Majorana edge states. We find that the thermal ground states, enjoying the Hamiltonian symmetries, show non-local convertibility if either A or B are smaller than, or of the order of, the correlation length. In contrast, the ordered (symmetry breaking) ground state is always locally convertible. The edge states behavior explains all these results and could disclose a paradigm to understand local convertibility in other quantum phases of matter. The connection we establish between convertibility and non-local, quantum correlations provides a clear criterion of which features a universal quantum simulator should possess to outperform a classical machine.

  14. Evaluation of dichalcogenide compounds as possible sorption reservoirs for thermionic converters

    SciTech Connect (OSTI)

    Garner, S.D.; Horner-Richardson, K.D. (Thermacore, Inc., 780 Eden Road, Lancaster, Pennsylvania 17601 (United States)); Kim, K.Y. (WL/POOC, Wright-Patterson AFB, Ohio 45433-6563 (United States))

    1993-01-20T23:59:59.000Z

    Recently a metal matrix sorption reservoir (MMSR) was developed for use as a self-regulating internal cesium reservoir for thermionic converters. The MMSR contains powdered graphite in a sintered refractory metal matrix. This innovation opens up the possibility of using alternative intercalating compounds previously overlooked because they are typically only available in powder form. One such alternative is the general class of materials known as dichalcogenides of metals. The dichalcogenide compounds are of the form MX[sub 2] where M is a metal and X is either S, Se or Te. The dichalcogenides have the laminar structure required for intercalation and some have been shown to intercalate liquid metals under certain conditions. Selected refractory metal dichalcogenides have been evaluated as potential cesium sorption reservoirs in thermionic converters. Testing showed the majority of the dichalcogenides are not stable in the thermal environment of current Thermionic Fuel Element (TFE) designs. Of the seven compounds that can survive the high temperatures and vacuum, four are not compatible with the cesium vapor at converter temperatures. The three remaining dichalcogenide compounds suitable for use in thermionic converters did not intercalate cesium at typical converter operating conditions. The result of this work allow the continued effort towards developing an internal self-regulating cesium reservoir to be concentrated on graphite contained in MMSRs.

  15. Emitter tests in an open thermionic converter with vapor injection through the collector

    SciTech Connect (OSTI)

    Wriedt, S.; Moeller, K.; Holmlid, L.

    1986-12-15T23:59:59.000Z

    Mo and Pt emitters and a Ni collector with 400 laser-bored holes were used in an ''open'' thermionic converter. The alkali vapor was introduced into the converter through the array of holes in the collector from an adjacent alkali metal reservoir with separately controlled temperature. The overall results from the open thermionic converter are comparable to results from enclosed converters. The results found with a Cs plasma are encouraging, with barrier indices down to below 1.8 eV, at emitter temperatures around 1500 K in the case of a Mo emitter. The output power density was around 3.5 W cm/sup -2/. In the case of a Pt emitter, both Cs and K plasmas were used, with power densities up to 5.7 and 1.8 W cm/sup -2/, respectively close to 1800 K. The structure of the laser-bored collector may have contributed to these results, as well as the efficient removal of impurities in the ''open'' converter.

  16. One-way wave-equation migration of compressional and converted waves in a VTI medium

    E-Print Network [OSTI]

    Ursin, Bjørn

    exploration and production. Horizontally layered sedi- mentary rocks exhibit anisotropy that can be described are useful for processing of conventional pressure data. Numer- ical examples demonstrate that the slowness; Barkved et al., 2004), hence reducing the risk in hydrocarbon ex- ploration and production. Shear

  17. Long-term shear strength behavior of a needlepunched geosynthetic clay liner

    SciTech Connect (OSTI)

    Trauger, R.J. [Colloid Environmental Technologies Co., Arlington Heights, IL (United States); Swan, R.H. Jr.; Yuan, Z. [GeoSyntec Consultants, Atlanta, GA (United States). Soil-Geosynthetic Interaction Testing Lab.

    1997-11-01T23:59:59.000Z

    This paper describes two large-scale constant-load (creep) shear testing devices that were developed to evaluate the long-term shearing behavior of geosynthetic clay liners (GCLs) and interfaces between GCLs and other geosynthetics or soils. One device was designed to simulate loading conditions that typically occur on a GCL deployed in a landfill cover system. The other device was designed to simulate loading conditions that typically occur on a GCL deployed in a landfill lining system. A needlepunched GCL was selected for evaluation of its long-term shearing behavior under these two types of loading conditions and the test results are presented in terms of time-displacement curves and shear rate-displacement curves. The results to date show that the GCL has undergone relatively small shear displacements and that the shear displacement rates within the GCL and/or at the test interface have been continuously decreasing with time. For the conditions used in this testing program, it is believed that the GCL`s behavior can be considered stable. Further testing is planned to more accurately define the time-dependent internal and interface shear behavior of the GCL.

  18. Dynamics and correlation length scales of a glass-forming liquid in quiescent and sheared conditions

    E-Print Network [OSTI]

    Wen-Sheng Xu; Zhao-Yan Sun; Li-Jia An

    2012-05-10T23:59:59.000Z

    We numerically study dynamics and correlation length scales of a colloidal liquid in both quiescent and sheared conditions to further understand the origin of slow dynamics and dynamic heterogeneity in glass-forming systems. The simulation is performed in a weakly frustrated two-dimensional liquid, where locally preferred order is allowed to develop with increasing density. The four-point density correlations and bond-orientation correlations, which have been frequently used to capture dynamic and static length scales $\\xi$ in a quiescent condition, can be readily extended to a system under steady shear in this case. In the absence of shear, we confirmed the previous findings that the dynamic slowing down accompanies the development of dynamic heterogeneity. The dynamic and static length scales increase with $\\alpha$-relaxation time $\\tau_{\\alpha}$ as power-law $\\xi\\sim\\tau_{\\alpha}^{\\mu}$ with $\\mu>0$. In the presence of shear, both viscosity and $\\tau_{\\alpha}$ have power-law dependence on shear rate in the marked shear thinning regime. However, dependence of correlation lengths cannot be described by power laws in the same regime. Furthermore, the relation $\\xi\\sim\\tau_{\\alpha}^{\\mu}$ between length scales and dynamics holds for not too strong shear where thermal fluctuations and external forces are both important in determining the properties of dense liquids. Thus, our results demonstrate a link between slow dynamics and structure in glass-forming liquids even under nonequilibrium conditions.

  19. Compact, Low-Profile Power Converters: Highly-Laminated, High-Saturation-Flux-Density, Magnetic Cores for On-Chip Inductors in Power Converter Applications

    SciTech Connect (OSTI)

    None

    2010-09-01T23:59:59.000Z

    ADEPT Project: Georgia Tech is creating compact, low-profile power adapters and power bricks using materials and tools adapted from other industries and from grid-scale power applications. Adapters and bricks convert electrical energy into useable power for many types of electronic devices, including laptop computers and mobile phones. These converters are often called wall warts because they are big, bulky, and sometimes cover up an adjacent wall socket that could be used to power another electronic device. The magnetic components traditionally used to make adapters and bricks have reached their limits; they can't be made any smaller without sacrificing performance. Georgia Tech is taking a cue from grid-scale power converters that use iron alloys as magnetic cores. These low-cost alloys can handle more power than other materials, but the iron must be stacked in insulated plates to maximize energy efficiency. In order to create compact, low-profile power adapters and bricks, these stacked iron plates must be extremely thin-only hundreds of nanometers in thickness, in fact. To make plates this thin, Georgia Tech is using manufacturing tools used in microelectromechanics and other small-scale industries.

  20. Shear thickening and jamming in densely packed suspensions of different particle shapes

    E-Print Network [OSTI]

    Eric Brown; Hanjun Zhang; Nicole A. Forman; Benjamin W. Maynor; Douglas E. Betts; Joseph M. DeSimone; Heinrich M. Jaeger

    2011-06-30T23:59:59.000Z

    We investigated the effects of particle shape on shear thickening in densely packed suspensions. Rods of different aspect ratios and non-convex hooked rods were fabricated. Viscosity curves and normal stresses were measured using a rheometer for a wide range of packing fractions for each shape. Suspensions of each shape exhibit qualitatively similar Discontinuous Shear Thickening. The logarithmic slope of the stress/shear-rate relation increases dramatically with packing fraction and diverges at a critical packing fraction phi_c which depends on particle shape. The packing fraction dependence of the viscosity curves for different convex shapes can be collapsed when the packing fraction is normalized by phi_c. Intriguingly, viscosity curves for non-convex particles do not collapse on the same set as convex particles, showing strong shear thickening over a wider range of packing fraction. The value of phi_c is found to coincide with the onset of a yield stress at the jamming transition, suggesting the jamming transition also controls shear thickening. The yield stress is found to correspond with trapped air in the suspensions, and the scale of the stress can be attributed to interfacial tension forces which dramatically increase above phi_c due to the geometric constraints of jamming. The relationship between shear and normal stresses is found to be linear in both the shear thickening and jammed regimes, indicating that the shear stresses come from friction. In the limit of zero shear rate, normal stresses pull the rheometer plates together due to the surface tension of the liquid below phi_c, but push the rheometer plates apart due to jamming above phi_c.

  1. Design considerations for a thermophotovoltaic energy converter using heat pipe radiators

    SciTech Connect (OSTI)

    Ashcroft, J.; DePoy, D. [Lockheed Martin Corp., Schenectady, NY (United States)

    1997-06-01T23:59:59.000Z

    The purpose of this paper is to discuss concepts for using high temperature heat pipes to transport energy from a heat source to a thermophotovoltaic (TPV) converter. Within the converter, the condenser portion of each heat pipe acts as a photon radiator, providing a radiant flux to adjacent TPV cells, which in turn create electricity. Using heat pipes in this way could help to increase the power output and the power density of TPV systems. TPV systems with radiator temperatures in the range of 1,500 K are expected to produce as much as 3.6 W/cm{sup 3} of heat exchanger volume at an efficiency of 20% or greater. Four different arrangements of heat pipe-TPV energy converters are considered. Performance and sizing calculations for each of the concepts are presented. Finally, concerns with this concept and issues which remain to be considered are discussed.

  2. DC to DC power converters and methods of controlling the same

    DOE Patents [OSTI]

    Steigerwald, Robert Louis; Elasser, Ahmed; Sabate, Juan Antonio; Todorovic, Maja Harfman; Agamy, Mohammed

    2012-12-11T23:59:59.000Z

    A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.

  3. Experience in the installation of a microprocessor system for controlling converter units of the Vyborg substation

    SciTech Connect (OSTI)

    Gusakovskii, K. B.; Zmaznov, E. Yu.; Katantsev, S. V.; Mazurenko, A. K.; Mestergazi, V. A.; Prochan, G. G.; Funtikova, S. F. [High Voltage Direct Current Power Transmission Research Institute (NIIPT) (Russian Federation)

    2006-01-15T23:59:59.000Z

    The experience in the installation of modern digital systems for controlling converter units at the Vyborg converter substation on the basis of advanced microprocessor devices is considered. It is shown that debugging of a control and protection system on mathematical and physical models does not guarantee optimum control of actual converter devices. Examples of advancing the control and protection system are described, the necessity for which has become obvious in tests of actual equipment. Comparison of oscillograms of processes before optimization of the control system and after its optimization and adjustment shows that the digital control system makes it possible to improve substantially the algorithms of control and protection in the short term and without changing the hardware component.

  4. Explicit computation of shear three-point correlation functions: the one-halo model case

    E-Print Network [OSTI]

    F. Bernardeau

    2005-05-16T23:59:59.000Z

    We present a method for calculating explicit expressions of the shear three-point function for various cosmological models. The method is applied here to the one-halo model in case of power law density profiles for which results are detailed. The three-point functions are found to reproduce to a large extent patterns in the shear correlations obtained in numerical simulations and may serve as a guideline to implement optimized methods for detecting the shear three-point function. In principle, the general method presented here can also be applied for other models of matter correlation.

  5. Nonlinear response of plain concrete shear walls with elastic-damaging behavior

    SciTech Connect (OSTI)

    Yazdani, S.; Schreyer, H.L.

    1997-02-01T23:59:59.000Z

    This report summarizes the theoretical and computational efforts on the modeling of small scale shear walls. Small scale shear walls are used extensively in the study of shear wall behavior because the construction and testing of full size walls are rather expensive. A finite element code is developed which incorporates nonlinear constitutive relations of damage mechanics. The program is used to obtain nonlinear load-deformation curves and to address the initial loss of stiffness due to shrinkage cracking. The program can also be used to monitor the continuous degradation of the fundamental frequency due to progressive damage.

  6. Nonlinear Shear Wave in a Non Newtonian Visco-elastic Medium

    E-Print Network [OSTI]

    Janaki, D Banerjee M S; Chaudhuri, M

    2013-01-01T23:59:59.000Z

    An analysis of nonlinear transverse shear wave has been carried out on non-Newtonian viscoelastic liquid using generalized hydrodynamic(GH) model. The nonlinear viscoelastic behavior is introduced through velocity shear dependence of viscosity coefficient by well known Carreau -Bird model. The dynamical feature of this shear wave leads to the celebrated Fermi-Pasta-Ulam (FPU) problem. Numerical solution has been obtained which shows that initial periodic solutions reoccur after passing through several patterns of periodic waves. A possible explanation for this periodic solution is given by constructing modified Korteweg de Vries (mKdV) equation. This model has application from laboratory to astrophysical plasmas as well as biological systems.

  7. Investigation of shear-banding mechanism in fully dense nanocrystalline Ni sheet

    SciTech Connect (OSTI)

    Zhu Rongtao [Department of Mechanical Engineering, Nanjing University of Technology, Nanjing, Jiangsu 210009 (China); Zhou Jianqiu, E-mail: zhouj@njut.edu.cn [Department of Mechanical Engineering, Nanjing University of Technology, Nanjing, Jiangsu 210009 (China); Li Xinbo; Jiang Hua; Ling Xiang [Department of Mechanical Engineering, Nanjing University of Technology, Nanjing, Jiangsu 210009 (China)

    2010-04-15T23:59:59.000Z

    Evolution of shear banding in fully dense electrodeposited nanocrystalline Ni was successfully monitored by using a digital image correlation technique under a quasi-static uniaxial tensile load. To investigate the microscopic physical mechanism of the shear banding, in-situ tensile testing for the nanocrystalline Ni sample was conducted in a transmission electron microscope and fracture surface of the sample was examined by field emission scanning electron microscope. The results suggest that grain boundary migration based on atomic diffusion is a main carrier of the shear banding.

  8. Anisotropic Power Law Strain Correlations in Sheared Amorphous 2D Solids

    SciTech Connect (OSTI)

    Maloney, C. E. [Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Robbins, M. O. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

    2009-06-05T23:59:59.000Z

    The local deformation of steadily sheared two-dimensional Lennard-Jones glasses is studied via computer simulations at zero temperature. In the quasistatic limit, spatial correlations in the incremental strain field are highly anisotropic. The data show power law behavior with a strong angular dependence of the scaling exponent, and the strongest correlations along the directions of maximal shear stress. These results support the notion that the jamming transition at the onset of flow is critical, but suggest unusual critical behavior. The predicted behavior is testable through experiments on sheared amorphous materials such as bubble rafts, foams, emulsions, granular packings, and other systems where particle displacements can be tracked.

  9. Evaluation of the effectiveness of shielding and filtering of HVDC converter stations

    SciTech Connect (OSTI)

    Dallaire, R.D.; Maruvada, P.S.

    1989-04-01T23:59:59.000Z

    The electromagnetic interference (EMI) generated by the periodic turn-on and turn-off of the valves is an important consideration in the design of HVDC converter stations. Remedial measures such as shielding the valve hall and filtering have been used in order to reduce the interference levels to acceptable values. The application of recently-developed Numerical Electromagnetic Code (NEC) to the problem of EMI from HVDC converter stations is investigated in this paper, with particular emphasis on evaluating the effectiveness of valve hall shielding and filtering.

  10. Risk assessment of converting salt caverns to natural gas storage. Final report, November 1994-July 1995

    SciTech Connect (OSTI)

    Harrison, M.R.; Ellis, P.F.

    1995-10-01T23:59:59.000Z

    The objective of this paper was an assessment of the risks of release of large quantities of natural gas from salt caverns converted from other uses to the storage of compressed natural gas (CNG). A total of 22 potential root causes for large releases of natural gas from converted salt converns were identified and ranked in terms of relative risk. While this project assessed the relative risks of major gas releases, the absolute risk was determined by implication to be extremely low, as indicated by the historical record.

  11. Chemical reactor for converting a first material into a second material

    DOE Patents [OSTI]

    Kong, Peter C

    2012-10-16T23:59:59.000Z

    A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

  12. Design and implementation of a scalable encryption processor with embedded variable dc/dc converter

    E-Print Network [OSTI]

    James Goodman; Anantha Chandrakasan; Abram P. Dancy

    1999-01-01T23:59:59.000Z

    This work describes the design and implementation of an energy-efficient, scalable encryption processor that utilizes variable voltage supply techniques and a highefficiency embedded variable output DC/DC converter. The resulting implementation dissipates 134nJ/bit @ V DD = 2.5V, when encrypting at its maximum rate of 1Mb/s using a maximum datapath width of 512 bits. The embedded converter achieves an efficiency of 96 % at this peak load. The processor is 2-3 orders of magnitude more energy efficient than optimized assembly code running on a low-power processor such as the StrongARM. 2.

  13. Composite resonance: A circuit approach to the waveform distortion dynamics of an HVdc converter

    SciTech Connect (OSTI)

    Wood, A.R.; Arrillaga, J. [Univ. of Canterbury, Christchurch (New Zealand)] [Univ. of Canterbury, Christchurch (New Zealand)

    1995-10-01T23:59:59.000Z

    A frequency domain analysis is applied to a controlled HVdc converter interconnecting ac and dc networks. The converter is considered as a three port network, and described using transfer functions. Using ac and dc system frequency dependent impedances an equivalent electrical circuit is constructed. The concept of composite resonance is introduced to emphasize the interaction between the ac and dc systems, and a simplified damping factor derived to predict the dynamics of waveform distortion during transient recovery. The frequency domain analysis is verified by dynamic simulation.

  14. Chemical reactor and method for chemically converting a first material into a second material

    DOE Patents [OSTI]

    Kong, Peter C. (Idaho Falls, ID)

    2008-04-08T23:59:59.000Z

    A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

  15. Fully Anisotropic String Cosmologies, Maxwell Fields and Primordial Shear

    E-Print Network [OSTI]

    Massimo Giovannini

    1998-12-07T23:59:59.000Z

    We present a class of exact cosmological solutions of the low energy string effective action in the presence of a homogeneous magnetic fields. We discuss the physical properties of the obtained (fully anisotropic) cosmologies paying particular attention to their vacuum limit and to the possible isotropization mechanisms. We argue that quadratic curvature corrections are able to isotropize fully anisotropic solutions whose scale factors describe accelerated expansion. Moreover, the degree of isotropization grows with the duration of the string phase. We follow the fate of the shear parameter in a decelerated phase where, dilaton, magnetic fields and radiation fluid are simultaneously present. In the absence of any magnetic field a long string phase immediately followed by radiation is able to erase large anisotropies. Conversely, if a short string phase is followed by a long dilaton dominated phase the anisotropies can be present, in principle, also at later times. The presence of magnetic seeds after the end of the string phase can induce further anisotropies which can be studied within the formalism reported in this paper.

  16. Modification of wheat straw in a high-shear mixer

    SciTech Connect (OSTI)

    Carr, M.E.; Doane, W.M.

    1984-01-01T23:59:59.000Z

    Wheat straw (WS) was treated in a pilot-scale continuous mixer to disrupt the lignin-hemicellulose-cellulose (LHC) complex. An efficient and practical method was desired to remove lignin and hemicellulose (pentosans) rapidly and efficiently from the lignocellulose complex and to make the cellulose accessible to enzymatic hydrolysis. Milled WS in the presence of various chemicals in aqueous solutions was extruded from the mixer under several processing conditions. Chemicals used were sodium hydroxide (NaOH), sodium sulfide (Na/sub 2/S), anthraquinone (AQ), anthrahydroquinone (AHQ), hexamethylenediamine (HMDA), hexamethylenetetramine (HMTA), hydrogen peroxide (H/sub 2/O/sub 2/), and ferrous ammonium sulfate (FAS), which were used alone and in selected combinations. Concomitantly, WS was treated in laboratory batches using similar reaction conditions, except for mixing shearing. In extrusion treatments of WS at 20% concentration at 97/sup 0/C for 5.5 min with NaOH (15.7%, dry WS basis), NaOH (15.7%) + AHQ (0.3%), and NaOH (12.7%) + Na/sub 2/S (5.0%), 64-72% of the WS lignin and 36-43% of the pentosans were removed from aqueously washed extrudates (residues). This compares with 46-56% and 23-27%, respectively, for batch treatments. AHQ and Na/sub 2/S enhanced delignification. Cellulase treatment of the residues, which contai

  17. Dynamics of the longitudinal and transverse modes in presence of equilibrium shear flow in a strongly coupled dusty plasma

    SciTech Connect (OSTI)

    Garai, S.; Banerjee, D.; Janaki, M. S.; Chakrabarti, N. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata - 700 064 (India)

    2014-02-11T23:59:59.000Z

    In strongly coupled limit the general hydrodynamic (GH) model shows that the dusty plasma, acquiring significant rigidity, is able to support the 'shear' like mode [P. K. Kaw and A. Sen, Phys. Plasmas 5, 3552 (1998)]. In presence of velocity shear, this shear like mode is coupled with the dust acoustic mode which is generated by the compressibility effect of the dust fluid due to the finite temperature of the dust, electron and ion fluids. Local dispersion shows the velocity shear is also responsible for the instabilities of the shear mode, acoustic mode, as well as the shear-acoustic coupled mode. The present work, carried out in GH visco-elastic formalism, also gives the clear insight of the instabilities of the coupled mode in non local regime with a hyperbolic tangent velocity shear profile over a finite width.

  18. Non-Newtonian behavior and molecular structure of Cooee bitumen under shear flow: a non-equilibrium molecular dynamics study

    E-Print Network [OSTI]

    Lemarchand, Claire A; Todd, Billy D; Daivis, Peter J; Hansen, Jesper S

    2015-01-01T23:59:59.000Z

    The rheology and molecular structure of a model bitumen (Cooee bitumen) under shear is investigated in the non-Newtonian regime using non-equilibrium molecular dynamics simulations. The shear viscosity and normal stress differences of the bitumen mixture are computed at different shear rates and different temperatures. The model bitumen is shown to be a shear-thinning fluid. The corresponding molecular structure is studied at the same shear rates and temperatures. The Cooee bitumen is able to reproduce experimental results showing the formation of nanoaggregates composed of stacks of flat aromatic molecules. These nanoaggregates are immersed in a solvent of saturated hydrocarbon molecules. The nanoaggregates are shown to break up at very high shear rates, leading only to a minor effect on the viscosity of the mixture. At low shear rates, bitumen can be seen as a colloidal suspension of nanoaggregates in a solvent. The slight anisotropy of the whole sample due to the nanoaggregates is considered and quantified...

  19. Electro-mechanical energy conversion system having a permanent magnet machine with stator, resonant transfer link and energy converter controls

    DOE Patents [OSTI]

    Skeist, S. Merrill; Baker, Richard H.

    2006-01-10T23:59:59.000Z

    An electro-mechanical energy conversion system coupled between an energy source and an energy load comprising an energy converter device including a permanent magnet induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer to control the flow of power or energy through the permanent magnetic induction machine.

  20. Dynamic fluid loss in hydraulic fracturing under realistic shear conditions in high-permeability rocks

    SciTech Connect (OSTI)

    Navarrete, R.C.; Cawiezel, K.E.; Constien, V.G. [Dowell Schlumberger, Tulsa, OK (United States)

    1996-08-01T23:59:59.000Z

    A study of the dynamic fluid loss of hydraulic fracturing fluids under realistic shear conditions is presented. During a hydraulic fracturing treatment, a polymeric solution is pumped under pressure down the well to create and propagate a fracture. Part of the fluid leaks into the rock formation, leaving a skin layer of polymer or polymer filter cake, at the rock surface or in the pore space. This study focuses on the effects of shear rate and permeability on dynamic fluid-loss behavior of crosslinked and linear fracturing gels. Previous studies of dynamic fluid loss have mainly been with low-permeability cores and constant shear rates. Here, the effect of shear history and fluid-loss additive on the dynamic leakoff of high-permeability cores is examined.