Sample records for ac variable frequency

  1. Variable Frequency AC Drives for Cooling Tower Energy Efficiency

    E-Print Network [OSTI]

    Corey, R. W.

    1982-01-01T23:59:59.000Z

    speed fan drives. Fan speed is reduced to yield specific water temperatures at thermal conditions less difficult than design. The reduced air flow is accomplished by reduced fan power consumption, resulting in optimum cooling tower operation... and economics. Automatic fan speed control by sensing cold water temperature is the economic essence of the application of adjustable frequency power to A-C fan motors. 2.2 Cell Partitions In some multi-cell mechanical-draft cooling towers, the isolation...

  2. Variable Frequency Pump Drives

    E-Print Network [OSTI]

    Karassik, I. J.; Petraccaro, L. L.; McGuire, J. T.

    . In a conventional pump and driver arrangement (for example, a centrifugal pump coupled to an AC induction motor'with no speed control provision), the motor runs at. a constant speed, which is determined by the incoming line frequency, and the pump... when it is needed. LONG RANGE DESIGN TRENDS The growing use of variable-frequency electric motor drives will permit the integration of 60 and 50 cycle pump lines. One important concern for future improvements is the growing possibility...

  3. Conservation Theory Process Control Using Variable Frequency Drives

    E-Print Network [OSTI]

    Myers, N. S.

    1980-01-01T23:59:59.000Z

    name from the vari able DC voltage which the rectifier section pro duces. Variable DC voltage is required in order to produce controlled AC with the volts per hz ratio constant. To operate an AC motor over a speed range from 5-60 hz and still... be capable of producing con stant torque,the ratio: Volts ~ = Constant must be satisfied. The rectifier and inverter stages work in concert to produce variable voltage, variable frequency AC power. The linear relation ship between voltage and frequency...

  4. High frequency AC power converter for low voltage circuits

    E-Print Network [OSTI]

    Salazar, Nathaniel Jay Tobias

    2012-01-01T23:59:59.000Z

    This thesis presents a novel AC power delivery architecture that is suitable for VHF frequency (50-100MHz) polyphase AC/DC power conversion in low voltage integrated circuits. A complete AC power delivery architecture was ...

  5. Low frequency ac waveform generator

    DOE Patents [OSTI]

    Bilharz, O.W.

    1983-11-22T23:59:59.000Z

    Low frequency sine, cosine, triangle and square waves are synthesized in circuitry which allows variation in the waveform amplitude and frequency while exhibiting good stability and without requiring significant stablization time. A triangle waveform is formed by a ramped integration process controlled by a saturation amplifier circuit which produces the necessary hysteresis for the triangle waveform. The output of the saturation circuit is tapped to produce the square waveform. The sine waveform is synthesized by taking the absolute value of the triangular waveform, raising this absolute value to a predetermined power, multiplying the raised absolute value of the triangle wave with the triangle wave itself and properly scaling the resultant waveform and subtracting it from the triangular waveform to a predetermined power and adding the squared waveform raised to the predetermined power with a DC reference and subtracting the squared waveform therefrom, with all waveforms properly scaled. The resultant waveform is then multiplied with a square wave in order to correct the polarity and produce the resultant cosine waveform.

  6. Low frequency AC waveform generator

    DOE Patents [OSTI]

    Bilharz, Oscar W. (Scotia, NY)

    1986-01-01T23:59:59.000Z

    Low frequency sine, cosine, triangle and square waves are synthesized in circuitry which allows variation in the waveform amplitude and frequency while exhibiting good stability and without requiring significant stabilization time. A triangle waveform is formed by a ramped integration process controlled by a saturation amplifier circuit which produces the necessary hysteresis for the triangle waveform. The output of the saturation circuit is tapped to produce the square waveform. The sine waveform is synthesized by taking the absolute value of the triangular waveform, raising this absolute value to a predetermined power, multiplying the raised absolute value of the triangle wave with the triangle wave itself and properly scaling the resultant waveform and subtracting it from the triangular waveform itself. The cosine is synthesized by squaring the triangular waveform, raising the triangular waveform to a predetermined power and adding the squared waveform raised to the predetermined power with a DC reference and subtracting the squared waveform therefrom, with all waveforms properly scaled. The resultant waveform is then multiplied with a square wave in order to correct the polarity and produce the resultant cosine waveform.

  7. Variable frequency microwave furnace system

    DOE Patents [OSTI]

    Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN)

    1994-01-01T23:59:59.000Z

    A variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency microwave furnace system (10) includes a microwave signal generator (12) or microwave voltage-controlled oscillator (14) for generating a low-power microwave signal for input to the microwave furnace. A first amplifier (18) may be provided to amplify the magnitude of the signal output from the microwave signal generator (12) or the microwave voltage-controlled oscillator (14). A second amplifier (20) is provided for processing the signal output by the first amplifier (18). The second amplifier (20) outputs the microwave signal input to the furnace cavity (34). In the preferred embodiment, the second amplifier (20) is a traveling-wave tube (TWT). A power supply (22) is provided for operation of the second amplifier (20). A directional coupler (24) is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

  8. Variable frequency microwave furnace system

    DOE Patents [OSTI]

    Bible, D.W.; Lauf, R.J.

    1994-06-14T23:59:59.000Z

    A variable frequency microwave furnace system designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity for testing or other selected applications. The variable frequency microwave furnace system includes a microwave signal generator or microwave voltage-controlled oscillator for generating a low-power microwave signal for input to the microwave furnace. A first amplifier may be provided to amplify the magnitude of the signal output from the microwave signal generator or the microwave voltage-controlled oscillator. A second amplifier is provided for processing the signal output by the first amplifier. The second amplifier outputs the microwave signal input to the furnace cavity. In the preferred embodiment, the second amplifier is a traveling-wave tube (TWT). A power supply is provided for operation of the second amplifier. A directional coupler is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter is provided for measuring the power delivered to the microwave furnace. A second power meter detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load. 5 figs.

  9. Variable frequency microprocessor clock generator

    SciTech Connect (OSTI)

    Branson, C.N.

    1989-04-04T23:59:59.000Z

    A microprocessor-based system is described comprising: a digital central microprocessor provided with a clock input and having a rate of operation determined by the frequency of a clock signal input thereto; memory means operably coupled to the central microprocessor for storing programs respectively including a plurality of instructions and addressable by the central microprocessor; peripheral device operably connected to the central microprocessor, the first peripheral device being addressable by the central microprocessor for control thereby; a system clock generator for generating a digital reference clock signal having a reference frequency rate; and frequency rate reduction circuit means connected between the clock generator and the clock input of the central microprocessor for selectively dividing the reference clock signal to generate a microprocessor clock signal as an input to the central microprocessor for clocking the central microprocessor.

  10. Application of multi-variable control for automatic frequency controller of HVDC transmission system

    SciTech Connect (OSTI)

    Sanpei, Masatoshi (Electric Power Development Co., Tokyo (Japan)); Kakehi, Atsuyuki; Takeda, Hideo (Toshiba Corp., Tokyo (Japan))

    1994-04-01T23:59:59.000Z

    In an HVDC transmission system that links two ac power systems, the automatic frequency controller (AFC) calculates power to be interchanged between the two ac systems according to their frequencies thereby improving the frequency characteristics of the two power systems. This paper introduces a newly developed dc AFC system, which applies a multi-variable control to the dc system-based frequency control. It is capable of controlling the frequencies of the two ac systems optimally while maintaining their stability. This system was developed for one of Japan's HVDC transmission facilities and produced good results in a combined test using a power system simulator. The field installation will be completed in March 1993, when the AFC system will enter service.

  11. Adhesive bonding using variable frequency microwave energy

    DOE Patents [OSTI]

    Lauf, Robert J. (Oak Ridge, TN); McMillan, April D. (Knoxville, TN); Paulauskas, Felix L. (Oak Ridge, TN); Fathi, Zakaryae (Cary, NC); Wei, Jianghua (Raleigh, NC)

    1998-01-01T23:59:59.000Z

    Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.

  12. Adhesive bonding using variable frequency microwave energy

    DOE Patents [OSTI]

    Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.; Fathi, Z.; Wei, J.

    1998-09-08T23:59:59.000Z

    Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy. 26 figs.

  13. Adhesive bonding using variable frequency microwave energy

    DOE Patents [OSTI]

    Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.; Fathi, Z.; Wei, J.

    1998-08-25T23:59:59.000Z

    Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy. 26 figs.

  14. Chapter 18: Variable Frequency Drive Evaluation Protocol

    SciTech Connect (OSTI)

    Romberger, J.

    2014-11-01T23:59:59.000Z

    An adjustable-speed drive (ASD) includes all devices that vary the speed of a rotating load, including those that vary the motor speed and linkage devices that allow constant motor speed while varying the load speed. The Variable Frequency Drive Evaluation Protocol presented here addresses evaluation issues for variable-frequency drives (VFDs) installed on commercial and industrial motor-driven centrifugal fans and pumps for which torque varies with speed. Constant torque load applications, such as those for positive displacement pumps, are not covered by this protocol. Other ASD devices, such as magnetic drive, eddy current drives, variable belt sheave drives, or direct current motor variable voltage drives, are also not addressed. The VFD is by far the most common type of ASD hardware. With VFD speed control on a centrifugal fan or pump motor, energy use follows the affinity laws, which state that the motor electricity demand is a cubic relationship to speed under ideal conditions. Therefore, if the motor runs at 75% speed, the motor demand will ideally be reduced to 42% of full load power; however, with other losses it is about 49% of full load power.

  15. Soft switched high frequency ac-link converter 

    E-Print Network [OSTI]

    Balakrishnan, Anand Kumar

    2009-05-15T23:59:59.000Z

    topology for medium and high power ac-ac, ac-dc and dc-ac applications. An ac-link formed by an inductor-capacitor pair replaces the conventional dc-link. Each leg of the converter is formed by two bidirectional switches. Power transfer from input to output...

  16. Industrial applications of variable frequency microwave energy in materials processing

    SciTech Connect (OSTI)

    Fathi, Z.; Tucker, D.A.; Lewis, W.A.; Wei, J.B. [Lambda Technologies, Inc., Raleigh, NC (United States)

    1996-12-31T23:59:59.000Z

    A review of some market-driven research, process applications and systems development is provided. The variable frequency microwave processing concepts are briefly described. Industrial processing using variable frequency microwave energy in the areas of polymerization, composite processing, bonding and plasma is discussed. Analytical applications inherent in the use of variable frequency and its control are demonstrated in the areas of materials signature analysis for volumetric cure monitoring.

  17. DNA MOLECULAR WIRE-BASED NANOELECTRONICS: NEW INSIGHT AND HIGH FREQUENCY AC ELECTRICAL

    E-Print Network [OSTI]

    Kassegne, Samuel Kinde

    DNA MOLECULAR WIRE-BASED NANOELECTRONICS: NEW INSIGHT AND HIGH FREQUENCY AC ELECTRICAL the Thesis of Denni Ari Wibowo: DNA Molecular Wire-Based Nanoelectronics: New Insight and High Frequency AC alone. #12;v ABSTRACT OF THE THESIS DNA Molecular Wire-Based Nanoelectronics: New Insight and High

  18. A system for tranmitting low frequency analog signals over ac power lines

    DOE Patents [OSTI]

    Baker, S.P.; Durall, R.L.; Haynes, H.D.

    1987-07-30T23:59:59.000Z

    A system for transmitting low frequency analog signals over ac power lines using FM modulation. A low frequency analog signal to be transmitted is first applied to a voltage-to-frequency converter where it is converted to a signal whose frequency varies in proportion to the analog signal amplitude. This signal is then used to modulate the carrier frequency of an FM transmitter coupled to an ac power line. The modulation signal frequency range is selected to be within the response band of the FM transmitter. The FM modulated carrier signal is received by an FM receiver coupled to the ac power line, demodulated and the demodulated signal frequency is converted by a frequency-to-voltage converter back to the form of the original low frequency analog input signal. 4 figs.

  19. Present and Future Modes of Low Frequency Climate Variability

    SciTech Connect (OSTI)

    Cane, Mark A.

    2014-02-20T23:59:59.000Z

    This project addressed area (1) of the FOA, “Interaction of Climate Change and Low Frequency Modes of Natural Climate Variability”. Our overarching objective is to detect, describe and understand the changes in low frequency variability between model simulations of the preindustrial climate and simulations of a doubled CO2 climate. The deliverables are a set of papers providing a dynamical characterization of interannual, decadal, and multidecadal variability in coupled models with attention to the changes in this low frequency variability between pre-industrial concentrations of greenhouse gases and a doubling of atmospheric concentrations of CO2. The principle mode of analysis, singular vector decomposition, is designed to advance our physical, mechanistic understanding. This study will include external natural variability due to solar and volcanic aerosol variations as well as variability internal to the climate system. An important byproduct is a set of analysis tools for estimating global singular vector structures from the archived output of model simulations.

  20. Variable Frequency Motor Drives: Harmonics, Power Factor, and Energy Efficiency

    E-Print Network [OSTI]

    Massey, G. W.

    Variable frequency motor drives (VFD's) have been on the market for many years. Early versions were unreliable and prone to failure. Relatively recent developments in Pulse-Width Modulated (PWM) waveform technology have improved VFD reliability...

  1. ac to dc converters: Topics by E-print Network

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

    to use solid state Inverters(DC to AC converters) to have a variable voltage, fixed or variable frequency power source available for industrial applications. With advancements...

  2. AC Resonant charger with charge rate unrelated to primary power frequency

    DOE Patents [OSTI]

    Watson, Harold (Torrance, CA)

    1982-01-01T23:59:59.000Z

    An AC resonant charger for a capacitive load, such as a PFN, is provided with a variable repetition rate unrelated to the frequency of a multi-phase AC power source by using a control unit to select and couple the phase of the power source to the resonant charger in order to charge the capacitive load with a phase that is the next to begin a half cycle. For optimum range in repetition rate and increased charging voltage, the resonant charger includes a step-up transformer and full-wave rectifier. The next phase selected may then be of either polarity, but is always selected to be of a polarity opposite the polarity of the last phase selected so that the transformer core does not saturate. Thyristors are used to select and couple the correct phase just after its zero crossover in response to a sharp pulse generated by a zero-crossover detector. The thyristor that is turned on then automatically turns off after a full half cycle of its associated phase input. A full-wave rectifier couples the secondary winding of the transformer to the load so that the load capacitance is always charged with the same polarity.

  3. The probable source of certain spurious frequencies found in the output of a variable speed generating system using slip recovery

    SciTech Connect (OSTI)

    Carlin, P.W.

    1989-06-01T23:59:59.000Z

    As part of US Department of Energy-sponsored research on wind energy, a Mod-O wind turbine was used to drive a variable-speed, wound-rotor, induction generator. Energy resulting from the slip frequency voltage in the generator rotor was rectified to dc, inverted back to utility frequency ac, and injected into the power line. Spurious changing frequencies displayed in the generator output by a spectrum analyzer are caused by ripple on the dc link. No resonances of any of these moving frequencies were seen in spite of the presence of a bank of power factor correcting capacitors. 5 figs.

  4. High Frequency Effects of Variable Frequency Drives (VFD) on Electrical Submersible Pump (ESP) Systems

    E-Print Network [OSTI]

    Ozkentli, Esra

    2012-10-19T23:59:59.000Z

    Variable frequency drives (VFD) and subsea (umbilical) cables are frequently used in electrical submersible pump (ESP) systems for offshore platforms. There are two basic system configurations for ESP systems; VFD can be installed on the platform...

  5. A very high frequency CMOS Variable Gain Amplifier

    E-Print Network [OSTI]

    Tan, Siang Tong

    2001-01-01T23:59:59.000Z

    A fully differential CMOS Variable Gain Amplifier (VGA) consisting of an analog multiplier, current gain stages, and resistor loads is designed for very high frequency applications. The gain can be programmed from 0dB to 40dB with -3dB bandwidth...

  6. Investigation of CandidateTechniquesfor High-Frequency AC Distributed Power Systems'

    E-Print Network [OSTI]

    Wu, Shin-Tson

    Investigation of CandidateTechniquesfor High-Frequency AC Distributed Power Systems' Shiguo Luo power systems PPSs) have been used extensively and a considerable amount of information is availableon and outlined in this paper. I. INTRODUCTION Power conversion system design issues are becoming increasingly

  7. STFC Introductory Summer School m.j.owens@reading.ac.uk18 Sept 2012 Solar Variability and

    E-Print Network [OSTI]

    STFC Introductory Summer School m.j.owens@reading.ac.uk18 Sept 2012 Solar Variability and Climate · The climate system · Solar variability · Solar effects on climate ­ Regional and global effects · The future? #12;STFC Introductory Summer School m.j.owens@reading.ac.uk Climate system #12;The source of much

  8. Wind spatial variability and topographic wave frequency Elad Shilo*1

    E-Print Network [OSTI]

    Ashkenazy, Yossi "Yosef"

    @agri.huji.ac.il. 2. Department of Solar Energy and Environmental Physics, Jacob Blaustein Institutes for Desert of Environmental Physics and Irrigation, Institute of Soils, Water and Environment Sciences, Agricultural Research

  9. Vacuum electron acceleration by using two variable frequency laser pulses

    SciTech Connect (OSTI)

    Saberi, H.; Maraghechi, B. [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)] [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)

    2013-12-15T23:59:59.000Z

    A method is proposed for producing a relativistic electron bunch in vacuum via direct acceleration by using two frequency-chirped laser pulses. We consider the linearly polarized frequency-chiped Hermit-Gaussian 0, 0 mode lasers with linear chirp in which the local frequency varies linearly in time and space. Electron motion is investigated through a numerical simulation using a three-dimensional particle trajectory code in which the relativistic Newton's equations of motion with corresponding Lorentz force are solved. Two oblique laser pulses with proper chirp parameters and propagation angles are used for the electron acceleration along the z-axis. In this way, an electron initially at rest located at the origin could achieve high energy, ?=319 with the scattering angle of 1.02{sup ?} with respect to the z-axis. Moreover, the acceleration of an electron in different initial positions on each coordinate axis is investigated. It was found that this mechanism has the capability of producing high energy electron microbunches with low scattering angles. The energy gain of an electron initially located at some regions on each axis could be greatly enhanced compared to the single pulse acceleration. Furthermore, the scattering angle will be lowered compared to the acceleration by using laser pulses propagating along the z-axis.

  10. Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System

    SciTech Connect (OSTI)

    Randy Peden; Sanjiv Shah

    2005-07-26T23:59:59.000Z

    This report describes complete results of the project entitled ''Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System''. This demonstration project was initiated in July 2003 and completed in March 2005. The objective of the project was to develop an integrated power production/variable frequency drive system that could easily be deployed in the oil field that would increase production and decrease operating costs. This report describes all the activities occurred and documents results of the demonstration.

  11. Stressing of turbine-generator-exciter shafts by variable-frequency currents superimposed on DC currents in asynchronous HVDC links and following disturbances at converter stations

    SciTech Connect (OSTI)

    Hammons, T.J.; Bremner, J.J. (Univ. of Glasgow (United Kingdom))

    1994-09-01T23:59:59.000Z

    Ripple currents on the DC side of both HVDC synchronous and asynchronous. Links together with cleared HVDC and AC system disturbances can excite in some circumstances onerous torsional vibrations in large steam generator shafts. The problem has assumed importance in recent months on account of the HVDC Link between Scotland and Northern Ireland going ahead, on account of the proposed Eire/Wales Link, and because AC/DC/AC couplers are to be installed extensively to interconnect the East and West European Grid Systems. This paper discusses and analyses excitation of shaft torsional vibrations in steam turbine-generator-exciter shafts in close proximity to HVDC converter stations by (1) variable-frequency ripple currents superimposed on the DC currents in asynchronous Links, and (2) disturbances at bi-polar converter stations. The time response and tables show that for the systems studied variable-frequency ripple currents superimposed on the DC current in asynchronous Links can excite shaft torsional vibrations, the very small noncharacteristic currents could result in onerous shaft torques which might damage the machine, and that DC line faults at converter stations in close proximity of steam turbine-generator units can excite onerous turbine-generator shaft torsional response. Detailed simulation of the HVDC converter and generator is necessary for precise assessments of shaft torsional response following HVDC converter station faults. 500MW, 660MW, 1000MW and 1300MW machines are considered in the analyses that are made.

  12. ENHANCED RECOVERY UTILIZING VARIABLE FREQUENCY DRIVES AND A DISTRIBUTED POWER SYSTEM TECHNICAL PROGRESS REPORT

    SciTech Connect (OSTI)

    Randy Peden; Sanjiv Shah

    2004-02-11T23:59:59.000Z

    This report describes the progress made during first six months of the project entitled ''Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System''. During this period, project plan, demonstration plan and project schedule were developed, equipment was ordered and baseline data was collected.

  13. Observed low frequency variability of the Brazil Current front Gustavo Jorge Goni,1

    E-Print Network [OSTI]

    of the Brazil Current front. Trends of eddy kinetic energy, sea height anomaly, sea surface temperature and windObserved low frequency variability of the Brazil Current front Gustavo Jorge Goni,1 Francis Bringas; published 29 October 2011. [1] The Brazil Current is a weak western boundary current, the southwest

  14. A direct AC-to-DC converter topology with high-frequency isolation

    E-Print Network [OSTI]

    Sulistyono, Widodo

    1994-01-01T23:59:59.000Z

    disadvantages of the conventional approach are: it requires relatively large input ac filter components, requires two stages of rectification and of de filtering (i.e., at the front-end and output rectifiers), and exhibit poor overall input power factor...

  15. 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...

  16. T Tauri variability in the context of the beat-frequency model

    E-Print Network [OSTI]

    K. W. Smith; G. F. Lewis; I. A. Bonnell

    1995-08-17T23:59:59.000Z

    We examine the implications of a beat frequency modulated model of T Tauri accretion. In particular we show that measurements of the variability of accretion generated lines can be used in conjunction with existing photometry to obtain a measurement of the underlying photospheric and disc flux. This provides an independent way of checking spectral energy distribution modelling. In addition, we show how spectroscopy of T Tauri stars can reveal the inclination angle between the magnetic axis and the plane of the disc.

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

    E-Print Network [OSTI]

    Amirabadi, Mahshid

    2013-08-07T23:59:59.000Z

    be used in a variety of applications, including photovoltaic power generation, wind power generation, and electric vehicles. In these converters the link current and voltage are both alternating and their frequency can be high, which leads...

  18. Analysis of variable-frequency currents superimposed on DC currents in asynchronous HVDC Links in stressing turbine-generator-exciter shafts

    SciTech Connect (OSTI)

    Hammons, T.J.; Bremner, J.J. [Univ. of Glasgow (United Kingdom)] [Univ. of Glasgow (United Kingdom)

    1995-03-01T23:59:59.000Z

    Ripple currents on the DC side of both HVDC asynchronous and synchronous Links can excite in some circumstances onerous torsional vibrations in large steam generator shafts. The problem has assumed importance in recent months on account of the HVDC Link between Scotland and Northern Ireland going ahead, on account of the proposed Eire/Wales Link, because AC/DC/AC couplers are to be installed to interconnect the East and West European Grid Systems, and because resonances have been observed on machines in close proximity to AC/DCIAC couplers and HVDC Links. This paper discusses and analyses excitation of shaft torsional vibrations in steam turbine-generator-exciter shafts in close proximity to HVDC converter stations by variable-frequency ripple currents superimposed on DC currents in asynchronous Links. It presents technical knowledge not arranged for convenient reference heretofore in studying possible excitation of turbine-generator-v/ exciter shaft torsional vibrations by non-characteristic HVDC converter harmonic currents if a machine should be considered to be at risk. Shaft torques in multi-machine networks are evaluated by proportioning HVDC Link disturbance currents to each machine at risk using system network data, generator data and fault analysis data considering frequency dependence of the system parameters. This scaling factor is calculated for different scenarios of system operation and load. Equivalent circuits for the synchronous generator are employed appropriately to correlate HVDC Link disturbance current impressed on the generator stator with s state torque excitation from which magnitude of turbine-generator-exciter shaft torque is deduced.

  19. Running time variability and resource allocation : a data-driven analysis of high-frequency bus operations

    E-Print Network [OSTI]

    Sánchez-Martínez, Gabriel Eduardo

    2013-01-01T23:59:59.000Z

    Running time variability is one of the most important factors determining service quality and operating cost of high-frequency bus transit. This research aims to improve performance analysis tools currently used in the bus ...

  20. Measured Savings of DC to AC Drive Retrofit in Plastic Extrusion

    E-Print Network [OSTI]

    Sfeir, R. A.

    2008-01-01T23:59:59.000Z

    This paper presents the potential electrical energy efficiency improvements for utilizing alternating current (AC) motors controlled by variable frequency drives (VFD) in place of direct current (DC) motors to drive plastic extrusion machines. A...

  1. Variable Frequency Operations of an Offshore Wind Power Plant with HVDC-VSC: Preprint

    SciTech Connect (OSTI)

    Gevorgian, V.; Singh, M.; Muljadi, E.

    2011-12-01T23:59:59.000Z

    In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated. Based on DOE study, wind power generation may reach 330 GW by 2030 at the level of penetration of 20% of the total energy production. From this amount of wind power, 54 GW of wind power will be generated at offshore wind power plants. The deployment of offshore wind power plants requires power transmission from the plant to the load center inland. Since this power transmission requires submarine cable, there is a need to use High-Voltage Direct Current (HVDC) transmission. Otherwise, if the power is transmitted via alternating current, the reactive power generated by the cable capacitance may cause an excessive over voltage in the middle of the transmission distance which requires unnecessary oversized cable voltage breakdown capability. The use of HVDC is usually required for transmission distance longer than 50 kilometers of submarine cables to be economical. The use of HVDC brings another advantage; it is capable of operating at variable frequency. The inland substation will be operated to 60 Hz synched with the grid, the offshore substation can be operated at variable frequency, thus allowing the wind power plant to be operated at constant Volt/Hz. In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated.

  2. A High Frequency Isolated Current-fed Bidirectional DC/AC Converter For Grid-Tied Energy Storage System

    E-Print Network [OSTI]

    King Jet, TSENG

    2013-01-01T23:59:59.000Z

    tied energy storage systems (ESS) will be voltage to a high-DC/AC converter to interface ESS based on low voltage cellscharging and discharging of the ESS and the control strategy

  3. Comparing Two Types of Magnetically- Coupled Adjustable Speed Drives with Variable Frequency Drives in Pump and Fan Applications

    E-Print Network [OSTI]

    Anderson, K. J.; Chvala, W. D.

    This paper presents the results from laboratory tests on MagnaDrive Corporations fixed-magnet magnetically-coupled adjustable speed drive (MC-ASD) and Coyote Electronics electromagnetic MC-ASD as compared to a typical variable frequency drive (VFD...

  4. Field Verification of Energy and Demand Savings of Two Injection Molding Machines Retrofitted with Variable Frequency Drives

    E-Print Network [OSTI]

    Liou, S. P.; Aguiar, D.

    Detailed field measurements of energy consumption (kWh) and demand (kW) are conducted on two injection molding machines (IMMs) used in a typical plastic manufacturing facility in the San Francisco Bay Area, with/without Variable Frequency Drives...

  5. Use of Frequency Response Metrics to Assess the Planning and Operating Requirements for Reliable Integration of Variable Renewable Generation

    SciTech Connect (OSTI)

    Eto, Joseph H.; Undrill, John; Mackin, Peter; Daschmans, Ron; Williams, Ben; Haney, Brian; Hunt, Randall; Ellis, Jeff; Illian, Howard; Martinez, Carlos; O'Malley, Mark; Coughlin, Katie; LaCommare, Kristina Hamachi

    2010-12-20T23:59:59.000Z

    An interconnected electric power system is a complex system that must be operated within a safe frequency range in order to reliably maintain the instantaneous balance between generation and load. This is accomplished by ensuring that adequate resources are available to respond to expected and unexpected imbalances and restoring frequency to its scheduled value in order to ensure uninterrupted electric service to customers. Electrical systems must be flexible enough to reliably operate under a variety of"change" scenarios. System planners and operators must understand how other parts of the system change in response to the initial change, and need tools to manage such changes to ensure reliable operation within the scheduled frequency range. This report presents a systematic approach to identifying metrics that are useful for operating and planning a reliable system with increased amounts of variable renewable generation which builds on existing industry practices for frequency control after unexpected loss of a large amount of generation. The report introduces a set of metrics or tools for measuring the adequacy of frequency response within an interconnection. Based on the concept of the frequency nadir, these metrics take advantage of new information gathering and processing capabilities that system operators are developing for wide-area situational awareness. Primary frequency response is the leading metric that will be used by this report to assess the adequacy of primary frequency control reserves necessary to ensure reliable operation. It measures what is needed to arrest frequency decline (i.e., to establish frequency nadir) at a frequency higher than the highest set point for under-frequency load shedding within an interconnection. These metrics can be used to guide the reliable operation of an interconnection under changing circumstances.

  6. The bi-variate frequency distribution of two concurrent climatic variables: a study of temperature and dew point 

    E-Print Network [OSTI]

    Zeitler, Jon William

    1991-01-01T23:59:59.000Z

    Study of Temperature and Dew Point (December 1991). Jon William Zeitler, B. S. , iowa State University Chair of Advisory Comminee; Prof. John F. Griffiths The bi-variate normal distribution was fitted for the mid-season months of January, April, July... as to style and content by: Jo F. Griffnhs "' (Chair of Committee) Robert C. Runnels (Member) J. ' e (Mem r) Edward J. ser (Head of Department) December 1991 ABSTRACT The Bi-Variate Frequency Distribution of Two Concurrent Climatic Variables: A...

  7. IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 17, NO. 2, JUNE 2007 3179 Variable Temperature Total AC Loss and Stability

    E-Print Network [OSTI]

    -temperature superconductors, sta- bility, superconducting filaments and wires. I. INTRODUCTION LARGE-SCALE power applications of high temperature superconductors (HTS) are looking more promising with the advances in commercial and increased stability. Both ac losses and stability of HTS materials are functions of temperature, transport

  8. Gassmann's fluid substitution and shear modulus variability in carbonates at laboratory seismic and ultrasonic frequencies

    E-Print Network [OSTI]

    Boise State University

    frequencies. Samples are measured dry humidi- fied and saturated with liquid butane and brine. Our carbon- ate rock shear-modulus change from dry to brine saturation conditions, and we investigate several rock velocities for either oil- or brine-saturated samples, al- though for some samples, Gassmann's theory

  9. Analysis and Simulation of Mechanical Trains Driven by Variable Frequency Drive Systems

    E-Print Network [OSTI]

    Han, Xu

    2012-02-14T23:59:59.000Z

    2. Three-Phase Inverter and PWM Sidebands . . . . . . . . . . 45 C. Motor-Compressor Machinery Train . . . . . . . . . . . . . . . . . . 48 1. Electric Induction Motor . . . . . . . . . . . . . . . . . . . . . . . 48 2. Mechanical Components... . . . . . . . . . . . . . . . . . . . . . . . 77 4. DC Bus Harmonic Frequency = 120 Hz . . . . . . . . . . . . . 82 V ANALYSIS OF CLOSED-LOOP CONTROL-FOC : : : : : : : : : : : 87 A. Analysis for Harmonic Sources . . . . . . . . . . . . . . . . . . . . . . 87 B. Motor-Gearbox-Compressor...

  10. A study of wind variability in the lower troposphere through power spectrum analysis at mesoscale frequencies

    E-Print Network [OSTI]

    Cornett, John Sheldon

    1966-01-01T23:59:59.000Z

    major energy peaks. One major peak occurred at a period of about 4 days and the second peak at a period of about 1 min with a rather broad, flat spectral curve in between these peaks. He attributed the low frequency peak to fluctuations in wind speed... tropospheze, both Mantis (1963) and Chiu (1960) found a high energy peak in the spectra of the horizontal wind components corresponding to synoptic-scale periods of 4 to 6 days. However, they were limited to considering periods of 2 days or more because...

  11. Use of Frequency Response Metrics to Assess the Planning and Operating Requirements for Reliable Integration of Variable Renewable Generation

    E-Print Network [OSTI]

    Eto, Joseph H.

    2011-01-01T23:59:59.000Z

    plants to frequency response during disturbances. Use ofkey event during a disturbance when the frequency stabilizesrestore frequency to normal following a disturbance and is

  12. Low-frequency variability and heat transport in a low-order nonlinear coupled ocean-atmosphere model

    E-Print Network [OSTI]

    Stéphane Vannitsem; Jonathan Demaeyer; Lesley De Cruz; Michael Ghil

    2014-12-01T23:59:59.000Z

    We formulate and study a low-order nonlinear coupled ocean-atmosphere model with an emphasis on the impact of radiative and heat fluxes and of the frictional coupling between the two components. This model version extends a previous 24-variable version by adding a dynamical equation for the passive advection of temperature in the ocean, together with an energy balance model. The bifurcation analysis and the numerical integration of the model reveal the presence of low-frequency variability (LFV) concentrated on and near a long-periodic, attracting orbit. This orbit combines atmospheric and oceanic modes, and it arises for large values of the meridional gradient of radiative input and of frictional coupling. Chaotic behavior develops around this orbit as it loses its stability; this behavior is still dominated by the LFV on decadal and multi-decadal time scales that is typical of oceanic processes. Atmospheric diagnostics also reveals the presence of predominant low- and high-pressure zones, as well as of a subtropical jet; these features recall realistic climatological properties of the oceanic atmosphere. Finally, a predictability analysis is performed. Once the decadal-scale periodic orbits develop, the coupled system's short-term instabilities --- as measured by its Lyapunov exponents --- are drastically reduced, indicating the ocean's stabilizing role on the atmospheric dynamics. On decadal time scales, the recurrence of the solution in a certain region of the invariant subspace associated with slow modes displays some extended predictability, as reflected by the oscillatory behavior of the error for the atmospheric variables at long lead times.

  13. 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.

  14. Variable Frequency Drives

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps1 - USAF Wind Power Program Latitude: N.

  15. Development and application of setup for ac magnetic field in neutron scattering experiments

    SciTech Connect (OSTI)

    Klimko, Sergey [Laboratoire Leon Brillouin, 91191 Gif-sur-Yvette (France); Zhernenkov, Kirill; Toperverg, Boris P.; Zabel, Hartmut [Institut fuer Festkoerperphys IV, Ruhr Universitaet Bochum, D-44780 Bochum (Germany)

    2010-10-15T23:59:59.000Z

    We report on a new setup developed for neutron scattering experiments in periodically alternating magnetic fields at the sample position. The assembly consisting of rf generator, amplifier, wide band transformer, and resonance circuit. It allows to generate homogeneous ac magnetic fields over a volume of a few cm{sup 3} and variable within a wide range of amplitudes and frequencies. The applicability of the device is exemplified by ac polarized neutron reflectometry (PNR): a new method established to probe remagnetization kinetics in soft ferromagnetic films. Test experiments with iron films demonstrate that the ac field within the accessible range of frequencies and amplitudes produces a dramatic effect on the PNR signal. This shows that the relevant ac field parameters generated by the device match well with the scales involved in the remagnetization processes. Other possible applications of the rf unit are briefly discussed.

  16. IEEE International Conference on Power and Energy (PECon 08), December 1-3, 2008, Johor Baharu, Malaysia Variable High Frequency Voltage Source for an

    E-Print Network [OSTI]

    Hammerton, James

    , Malaysia Variable High Frequency Voltage Source for an Ohmic Heating Process A. Toudeshki, N. Mariun SMIEEE: arashtoudeshki@gmail.com Abstract-- Heating is an important step in food processing. A new method of heating uses the natural electrical resistance of the food to generate heat. In this method electrical energy

  17. Use of Frequency Response Metrics to Assess the Planning and Operating Requirements for Reliable Integration of Variable Renewable Generation

    E-Print Network [OSTI]

    Eto, Joseph H.

    2011-01-01T23:59:59.000Z

    of the Impact of Wind Generation on System Frequency2008. Analysis of Wind Generation Impact on ERCOT Ancillarywith Increased Wind Generation. LBNL-XXXX. Berkeley:

  18. Use of Frequency Response Metrics to Assess the Planning and Operating Requirements for Reliable Integration of Variable Renewable Generation

    E-Print Network [OSTI]

    Eto, Joseph H.

    2011-01-01T23:59:59.000Z

    of Variable Renewable Generation The report is accompaniedit Relates to Wind-Powered Generation. LBNL-XXXX. Berkeley:with Increased Wind Generation. LBNL-XXXX. Berkeley:

  19. Power links with Ireland -- Excitation of turbine-generator shaft torsional vibrations by variable frequency currents superimposed on DC currents in asynchronous HVDC links

    SciTech Connect (OSTI)

    Hammons, T.J.; Tay, B.W.; Kok, K.L. [Glasgow Univ. (United Kingdom)] [Glasgow Univ. (United Kingdom)

    1995-08-01T23:59:59.000Z

    The paper describes an in-depth analysis of excitation of shaft torsional vibrations in steam-turbine-generator-exciter shafts in close proximity to HVDC converter stations by variable-frequency ripple currents superimposed on the DC currents in asynchronous Links. It extends earlier work to include an in depth analysis of system scaling factors for harmonic currents impressed on generators in Northern Ireland by an inverter and to investigate the phenomena for possible torsional vibrations in the generators by the Link. Frequencies at which shaft torsional vibrations would be excited by modulation product harmonics in 50Hz/50Hz asynchronous Links as a function of deviation in system frequency is reviewed. Relative noncharacteristic current levels for 50Hz/50Hz connectors are illustrated assuming ripple currents at the inverter which gives realistic harmonic voltages in a twelve-pulse bridge. The paper then shows that torques in machines in multi-machine networks may be estimated by proportioning HVDC link harmonic disturbance current appropriately to each machine at risk. It is concluded that variable-frequency ripple currents superimposed on the DC current in asynchronous links can excite sympathetic torsional vibrations in turbine-generator-exciter shafts.

  20. Use of Frequency Response Metrics to Assess the Planning and Operating Requirements for Reliable Integration of Variable Renewable Generation

    E-Print Network [OSTI]

    Eto, Joseph H.

    2011-01-01T23:59:59.000Z

    of Governor Deadband & Droop Settings of a Single 600 MWIn both cases, the frequency droop setting is equal for allgenerating units. Droop is a measure of the change in power

  1. Use of Frequency Response Metrics to Assess the Planning and Operating Requirements for Reliable Integration of Variable Renewable Generation

    E-Print Network [OSTI]

    Eto, Joseph H.

    2011-01-01T23:59:59.000Z

    Responsive Reserve Report. WECC Frequency Responsive Reserve=&View={BB5A76DA-21C8-48FC-9468-F82B395DF8F9} WECC.2008. WECC Standard BAL-002-WECC-1 - Contingency Reserves.

  2. english 31AC african-amercan studies 17AC history 7B public health 130AC sociology 3AC education 30AC ethnic studies 135AC geography 150AC history 127AC information 142AC psychology 125AC anthropology 2AC american

    E-Print Network [OSTI]

    Alvarez-Cohen, Lisa

    · anthropology 2AC · american studies 10AC · gender and womens studies 50AC · music 26AC · spanish 135AC 50AC · music 26AC · spanish 135AC · sociology 190AC · public policy 117AC · peace and conflict studies 10AC · gender and womens studies 50AC · music 26AC · spanish 135AC · sociology 190AC · public

  3. Analysis on the energy efficiency of variable-frequency air conditioners (Hitachi models as an example) Jim Jr-Min Lin 2014.09.26

    E-Print Network [OSTI]

    Analysis on the energy efficiency of variable-frequency air conditioners (Hitachi models (Max) Energy Efficiency @min load Energy Efficiency @Max load kW kW kW kW W/W W/W RAS-22NB 1.00 3.20 0 Efficiency @min load Energy Efficiency @Max load kW kW kW kW W/W W/W RAM-5FNS(B) - 12.5 - 2.91 - 4.3 RAM-6FNS

  4. Techniques for energy conservation in ac motor-driven systems. Final report

    SciTech Connect (OSTI)

    Mohan, N.

    1981-09-01T23:59:59.000Z

    Techniques for energy conservation of reducing losses in ac motor-driven systems proposed by the technical community in response to surging cost of energy are evaluated and compared. Report objectives are to provide better understanding of underlying principles and to evaluate technical and economic viability of these techniques for various applications. An important aspect considered is the impact on electric utility system in terms of harmonics, power factor of operation, and Electro-Magnetic Interference (EMI). The techniques evaluated are: NASA Power Factor Controller, a simple device for reducing power losses in lightly loaded ac motors; wanlass motor modification, a scheme of reconnecting motor windings with capacitors in series, with the intention of improving the motor efficiencies under all loading conditions; conventional variable frequency solid-state inverters which can control the speed of ac motors by producing adjustable frequency ac voltage, with a significant potential for energy conservation in pumps and air-handling systems; and other variable frequency drives and schemes including cycloconverters, slip-recovery scheme, Exxon Alternating Current Synthesizer, Venturini conversion technique, permanent magnet synchronous motors, and a device called the Phase-Liner. The impact of rapid growth in semiconductors and magnetic materials technologies is also considered.

  5. Collaborative Research: Process-Resolving Decomposition of the Global Temperature Response to Modes of Low Frequency Variability in a Changing Climate

    SciTech Connect (OSTI)

    Deng, Yi

    2014-11-24T23:59:59.000Z

    DOE-GTRC-05596 11/24/2104 Collaborative Research: Process-Resolving Decomposition of the Global Temperature Response to Modes of Low Frequency Variability in a Changing Climate PI: Dr. Yi Deng (PI) School of Earth and Atmospheric Sciences Georgia Institute of Technology 404-385-1821, yi.deng@eas.gatech.edu El Niño-Southern Oscillation (ENSO) and Annular Modes (AMs) represent respectively the most important modes of low frequency variability in the tropical and extratropical circulations. The projection of future changes in the ENSO and AM variability, however, remains highly uncertain with the state-of-the-science climate models. This project conducted a process-resolving, quantitative evaluations of the ENSO and AM variability in the modern reanalysis observations and in climate model simulations. The goal is to identify and understand the sources of uncertainty and biases in models’ representation of ENSO and AM variability. Using a feedback analysis method originally formulated by one of the collaborative PIs, we partitioned the 3D atmospheric temperature anomalies and surface temperature anomalies associated with ENSO and AM variability into components linked to 1) radiation-related thermodynamic processes such as cloud and water vapor feedbacks, 2) local dynamical processes including convection and turbulent/diffusive energy transfer and 3) non-local dynamical processes such as the horizontal energy transport in the oceans and atmosphere. In the past 4 years, the research conducted at Georgia Tech under the support of this project has led to 15 peer-reviewed publications and 9 conference/workshop presentations. Two graduate students and one postdoctoral fellow also received research training through participating the project activities. This final technical report summarizes key scientific discoveries we made and provides also a list of all publications and conference presentations resulted from research activities at Georgia Tech. The main findings include: 1) the distinctly different roles played by atmospheric dynamical processes in establishing surface temperature response to ENSO at tropics and extratropics (i.e., atmospheric dynamics disperses energy out of tropics during ENSO warm events and modulate surface temperature at mid-, high-latitudes through controlling downward longwave radiation); 2) the representations of ENSO-related temperature response in climate models fail to converge at the process-level particularly over extratropics (i.e., models produce the right temperature responses to ENSO but with wrong reasons); 3) water vapor feedback contributes substantially to the temperature anomalies found over U.S. during different phases of the Northern Annular Mode (NAM), which adds new insight to the traditional picture that cold/warm advective processes are the main drivers of local temperature responses to the NAM; 4) the overall land surface temperature biases in the latest NCAR model (CESM1) are caused by biases in surface albedo while the surface temperature biases over ocean are related to multiple factors including biases in model albedo, cloud and oceanic dynamics, and the temperature biases over different ocean basins are also induced by different process biases. These results provide a detailed guidance for process-level model turning and improvement, and thus contribute directly to the overall goal of reducing model uncertainty in projecting future changes in the Earth’s climate system, especially in the ENSO and AM variability.

  6. RHIC spin flipper AC dipole controller

    SciTech Connect (OSTI)

    Oddo, P.; Bai, M.; Dawson, C.; Gassner, D.; Harvey, M.; Hayes, T.; Mernick, K.; Minty, M.; Roser, T.; Severino, F.; Smith, K.

    2011-03-28T23:59:59.000Z

    The RHIC Spin Flipper's five high-Q AC dipoles which are driven by a swept frequency waveform require precise control of phase and amplitude during the sweep. This control is achieved using FPGA based feedback controllers. Multiple feedback loops are used to and dynamically tune the magnets. The current implementation and results will be presented. Work on a new spin flipper for RHIC (Relativistic Heavy Ion Collider) incorporating multiple dynamically tuned high-Q AC-dipoles has been developed for RHIC spin-physics experiments. A spin flipper is needed to cancel systematic errors by reversing the spin direction of the two colliding beams multiple times during a store. The spin flipper system consists of four DC-dipole magnets (spin rotators) and five AC-dipole magnets. Multiple AC-dipoles are needed to localize the driven coherent betatron oscillation inside the spin flipper. Operationally the AC-dipoles form two swept frequency bumps that minimize the effect of the AC-dipole dipoles outside of the spin flipper. Both AC bumps operate at the same frequency, but are phase shifted from each other. The AC-dipoles therefore require precise control over amplitude and phase making the implementation of the AC-dipole controller the central challenge.

  7. I: Low Frequency NMR and NQR Using a dc SQUID. II: Variable-temperature 13C CP/MAS of Organometallics

    SciTech Connect (OSTI)

    Ziegeweid, M.A.

    1995-11-29T23:59:59.000Z

    NMR and NQR at low frequencies are difficult prospects due to small nuclear spin polarization. Furthermore, the sensitivity'of the inductive pickup circuitry of standard spectrometers is reduced as the frequency is lowered. I have used a cw-SQUID (Superconducting QUantum Interference Device) spectrometer, which has no such frequency dependence, to study the local atomic environment of {sup 14}N via the quadrupolar interaction. Because {sup 14}N has spin I = 1 and a 0-6 MHz frequency range, it is not possible to obtain well-resolved spectra in high magnetic fields. I have used a technique to observe {sup 14}N NQR resonances via their effect on neighboring protons mediated by the heteronuclear dipolar interaction to study peptides and narcotics. The sensitivity of the SQUID is not enough to measure low-frequency surface (or other low spin density) systems. The application of spin-polarized xenon has been previously used to enhance polarization in conventional NMR experiments. Because xenon only polarizes spins with which it is in contact, it is surface selective. While differences in chemical shifts between surface and bulk spins are not large, it is expected that the differences in quadrupole coupling constant should be very large due to the drastic change of the electric field gradient surrounding spins at the surface. With this in mind, I have taken preliminary steps to measure SQUID detected polarization transfer from Xe to another spin species at 4.2 K and in small magnetic fields (<50 G). In this regime, the spin-lattice relaxation of xenon is dependent on the applied magnetic field. The results of our efforts to characterize the relaxation of xenon are presented. The final section describes the solid-state variable-temperature (VT) one- and two-dimensional {sup 13}C cross polarization (CP)/magic angle spinning (MAS) NMR of Hf({eta}{sup 5}-C{sub 5}H{sub 5}){sub 2}({eta}{sup 1}-C{sub 5}H{sub 5}){sub 2}, Zr({eta}{sup 5}-C{sub 5}H{sub 5}){sub 3}({eta}{sup 1}-C{sub 5}H{sub 5}) and Sn({eta}{sup 1}-C{sub 5}H{sub 5}){sub 4}. This work was undertaken in the hope of gaining insight into the intramolecuhrr dynamics, specifically which fluxional processes exist in the solid state, by what mechanism rearrangements are occurring, and the activation energies by which these processes are governed.

  8. Making an Energy Histogram Using Pierre Auger Observatory Surface Detector Data A histogram is essentially a graphical representation of the frequency or distribution of a variable over specific intervals

    E-Print Network [OSTI]

    Making an Energy Histogram Using Pierre Auger Observatory Surface Detector Data Histogram A histogram is essentially a graphical representation of the frequency or distribution of a variable over energies. Before you start you should know that: o This set of instructions only assumes a very minimal

  9. Frequency modulation drive for a piezoelectric motor

    DOE Patents [OSTI]

    Mittas, Anthony (Albuquerque, NM)

    2001-01-01T23:59:59.000Z

    A piezoelectric motor has peak performance at a specific frequency f.sub.1 that may vary over a range of frequencies. A drive system is disclosed for operating such a motor at peak performance without feedback. The drive system consists of the motor and an ac source connected to power the motor, the ac source repeatedly generating a frequency over a range from f.sub.1 -.DELTA.x to f.sub.1 +.DELTA.y.

  10. Hybrid immersed interface-immersed boundary methods for AC dielectrophoresis

    SciTech Connect (OSTI)

    Hossan, Mohammad Robiul [School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920 (United States); Department of Engineering and Physics, University of Central Oklahoma, Edmond, OK 73034-5209 (United States); Dillon, Robert [Department of Mathematics, Washington State University, Pullman, WA 99164-3113 (United States); Dutta, Prashanta, E-mail: dutta@mail.wsu.edu [School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920 (United States)

    2014-08-01T23:59:59.000Z

    Dielectrophoresis, a nonlinear electrokinetic transport mechanism, has become popular in many engineering applications including manipulation, characterization and actuation of biomaterials, particles and biological cells. In this paper, we present a hybrid immersed interface–immersed boundary method to study AC dielectrophoresis where an algorithm is developed to solve the complex Poisson equation using a real variable formulation. An immersed interface method is employed to obtain the AC electric field in a fluid media with suspended particles and an immersed boundary method is used for the fluid equations and particle transport. The convergence of the proposed algorithm as well as validation of the hybrid scheme with experimental results is presented. In this paper, the Maxwell stress tensor is used to calculate the dielectrophoretic force acting on particles by considering the physical effect of particles in the computational domain. Thus, this study eliminates the approximations used in point dipole methods for calculating dielectrophoretic force. A comparative study between Maxwell stress tensor and point dipole methods for computing dielectrophoretic forces are presented. The hybrid method is used to investigate the physics of dielectrophoresis in microfluidic devices using an AC electric field. The numerical results show that with proper design and appropriate selection of applied potential and frequency, global electric field minima can be obtained to facilitate multiple particle trapping by exploiting the mechanism of negative dielectrophoresis. Our numerical results also show that electrically neutral particles form a chain parallel to the applied electric field irrespective of their initial orientation when an AC electric field is applied. This proposed hybrid numerical scheme will help to better understand dielectrophoresis and to design and optimize microfluidic devices.

  11. ac josephson effect: Topics by E-print Network

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

    in the dc mass currents voltage, a high frequency ac voltage is applied across a superconduct- ing Josephson junction, the dc, Dm 22eV, application of a dc voltage produces...

  12. Strongly nonlinear dynamics of electrolytes in large ac voltages

    E-Print Network [OSTI]

    Hojgaard Olesen, Laurits

    We study the response of a model microelectrochemical cell to a large ac voltage of frequency comparable to the inverse cell relaxation time. To bring out the basic physics, we consider the simplest possible model of a ...

  13. 3.3.3AC Sweep AC . AC

    E-Print Network [OSTI]

    ­. DC ­ AC ­) .( . ­ ,, '­Spice .Spice . : 0 0 E1 PWR(V(%IN+, %IN . )2.3( Etable " . . : 00 V1 0Vdc E2 Pwr(V(%IN+, %IN-),2) ETABLE TABLE = (5

  14. Radio-Frequency Beam Conditioner for Fast-Wave Free-Electron Generators of Coherent Radiation

    E-Print Network [OSTI]

    Sessler, Andrew M.

    2008-01-01T23:59:59.000Z

    to Physical Review Letters Radio-Frequency Beam ConditionerDE-AC03-76SF00098 LBL-31006 RADIO-FREQUENCY BEAM CONDITIONERIbaraki, 305, Japan. RADIO-FREQUENCY BEAM CONDITIONER FOR

  15. Coordination of Voltage and Frequency Feedback in Load-Frequency Control Capability of Wind Turbine

    E-Print Network [OSTI]

    Silva, Filipe Faria Da

    Coordination of Voltage and Frequency Feedback in Load-Frequency Control Capability of Wind Turbine-Frequency Control (LFC) is gradually shifted to Variable Speed Wind Turbines (VSWTs). In order to equip VSWT

  16. www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY

    E-Print Network [OSTI]

    de Gispert, Adrià

    but low variable cost capacity (coal-fired plants), and the other building low polluting but high variable in electricity generation market who are planning to expand generation capacity. They are anticipating regulation.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY We consider investments by two types of investors, one building highly polluting

  17. Optimization of spin-torque switching using AC and DC pulses

    SciTech Connect (OSTI)

    Dunn, Tom [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Kamenev, Alex [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2014-06-21T23:59:59.000Z

    We explore spin-torque induced magnetic reversal in magnetic tunnel junctions using combined AC and DC spin-current pulses. We calculate the optimal pulse times and current strengths for both AC and DC pulses as well as the optimal AC signal frequency, needed to minimize the Joule heat lost during the switching process. The results of this optimization are compared against numeric simulations. Finally, we show how this optimization leads to different dynamic regimes, where switching is optimized by either a purely AC or DC spin-current, or a combination AC/DC spin-current, depending on the anisotropy energies and the spin-current polarization.

  18. Fluctuation of an ion beam extracted from an AC filament driven Bernas-type ion source

    SciTech Connect (OSTI)

    Miyamoto, N., E-mail: nmiyamot@mail.doshisha.ac.jp; Okajima, Y.; Wada, M. [Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)] [Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)

    2014-02-15T23:59:59.000Z

    Argon ion beam fluctuation from an AC filament driven Bernas-type ion source is observed. The ion beam was measured by an 8 measurement elements beam profile monitor. The amplitude of the beam current fluctuation stayed in the same level from 100 Hz to 1 kHz of the filament heating frequency. The beam current fluctuation frequency measured by the beam profile monitor was equal to the frequency of the AC filament operation. The fluctuation amplitudes of the beam current by AC operation were less than 7% and were in the same level of the DC operation.

  19. Power conversion architecture for grid interface at high switching frequency

    E-Print Network [OSTI]

    Lim, Seungbum

    This paper presents a new power conversion architecture for single-phase grid interface. The proposed architecture is suitable for realizing miniaturized ac-dc converters operating at high frequencies (HF, above 3 MHz) and ...

  20. Design and analysis of modern three-phase AC/AC power converters for AC drives and utility interface 

    E-Print Network [OSTI]

    Kwak, Sangshin

    2005-08-29T23:59:59.000Z

    Significant advances in modern ac/ac power converter technologies and demands of industries have reached beyond standard ac/ac power converters with voltage-source inverters fed from diode rectifiers. Power electronics converters have been matured...

  1. Variable rate CELP speech coding using widely variable parameter updates

    E-Print Network [OSTI]

    Moodie, Myron L.

    1995-01-01T23:59:59.000Z

    bit rates for a given quality level. This work develops new techniques, referred to as widely variable CELP parameter updates, which dynamically adapt the transmit frequency of the CELP spectral parameters to the characteristics of the input speech...

  2. Monitoring method and apparatus using high-frequency carrier

    DOE Patents [OSTI]

    Haynes, Howard D. (Knoxville, TN)

    1996-01-01T23:59:59.000Z

    A method and apparatus for monitoring an electrical-motor-driven device by injecting a high frequency carrier signal onto the power line current. The method is accomplished by injecting a high frequency carrier signal onto an AC power line current. The AC power line current supplies the electrical-motor-driven device with electrical energy. As a result, electrical and mechanical characteristics of the electrical-motor-driven device modulate the high frequency carrier signal and the AC power line current. The high frequency carrier signal is then monitored, conditioned and demodulated. Finally, the modulated high frequency carrier signal is analyzed to ascertain the operating condition of the electrical-motor-driven device.

  3. Monitoring method and apparatus using high-frequency carrier

    DOE Patents [OSTI]

    Haynes, H.D.

    1996-04-30T23:59:59.000Z

    A method and apparatus for monitoring an electrical-motor-driven device by injecting a high frequency carrier signal onto the power line current. The method is accomplished by injecting a high frequency carrier signal onto an AC power line current. The AC power line current supplies the electrical-motor-driven device with electrical energy. As a result, electrical and mechanical characteristics of the electrical-motor-driven device modulate the high frequency carrier signal and the AC power line current. The high frequency carrier signal is then monitored, conditioned and demodulated. Finally, the modulated high frequency carrier signal is analyzed to ascertain the operating condition of the electrical-motor-driven device. 6 figs.

  4. Electrical power inverter having a phase modulated, twin-inverter, high frequency link and an energy storage module

    DOE Patents [OSTI]

    Pitel, Ira J. (Whippany, NJ)

    1987-02-03T23:59:59.000Z

    The present invention provides an electrical power inverter method and apparatus, which includes a high frequency link, for converting DC power into AC power. Generally stated, the apparatus includes a first high frequency module which produces an AC voltage at a first output frequency, and a second high frequency inverter module which produces an AC voltage at a second output frequency that is substantially the same as the first output frequency. The second AC voltage is out of phase with the first AC voltage by a selected angular phase displacement. A mixer mixes the first and second output voltages to produce a high frequency carrier which has a selected base frequency impressed on the sidebands thereof. A rectifier rectifies the carrier, and a filter filters the rectified carrier. An output inverter inverts the filtered carrier to produce an AC line voltage at the selected base frequency. A phase modulator adjusts the relative angular phase displacement between the outputs of the first and second high frequency modules to control the base frequency and magnitude of the AC line voltage.

  5. Electrical power inverter having a phase modulated, twin-inverter, high frequency link and an energy storage module

    DOE Patents [OSTI]

    Pitel, I.J.

    1987-02-03T23:59:59.000Z

    The present invention provides an electrical power inverter method and apparatus, which includes a high frequency link, for converting DC power into AC power. Generally stated, the apparatus includes a first high frequency module which produces an AC voltage at a first output frequency, and a second high frequency inverter module which produces an AC voltage at a second output frequency that is substantially the same as the first output frequency. The second AC voltage is out of phase with the first AC voltage by a selected angular phase displacement. A mixer mixes the first and second output voltages to produce a high frequency carrier which has a selected base frequency impressed on the sidebands thereof. A rectifier rectifies the carrier, and a filter filters the rectified carrier. An output inverter inverts the filtered carrier to produce an AC line voltage at the selected base frequency. A phase modulator adjusts the relative angular phase displacement between the outputs of the first and second high frequency modules to control the base frequency and magnitude of the AC line voltage. 19 figs.

  6. IEEE ELECTRON DEVICE LETTERS, VOL. 18, NO. 2, FEBRUARY 1997 39 AC Hot-Carrier-Induced Degradation in

    E-Print Network [OSTI]

    Ng, Wai Tung

    IEEE ELECTRON DEVICE LETTERS, VOL. 18, NO. 2, FEBRUARY 1997 39 AC Hot-Carrier-Induced Degradation--Frequency-dependent ac-stress-induced degradation in NMOSFET's with N2O-grown and N2O-nitrided gate oxides was investigated. Suppressed device degradation is observed in both N2O-based devices as compared to SiO2 device

  7. 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

  8. AC and DC power transmission

    SciTech Connect (OSTI)

    Not Available

    1985-01-01T23:59:59.000Z

    The technical and economic assessment of AC and DC transmission systems; long distance transmission, cable transmission, system inter-connection, voltage support, reactive compensation, stabilisation of systems; parallel operation of DC links with AC systems; comparison between alternatives for particular schemes. Design and application equipment: design, testing and application of equipment for HVDC, series and shunt static compensated AC schemes, including associated controls. Installations: overall design of stations and conductor arrangements for HVDC, series and shunt static AC schemes including insulation co-ordination. System analysis and modelling.

  9. Soft switched high frequency ac-link converter

    E-Print Network [OSTI]

    Balakrishnan, Anand Kumar

    2009-05-15T23:59:59.000Z

    place through the 16 modes: energizing, partial reso- nance and de-energizing. The link is energized from the inputs during modes 1, 3, 9 and 11 and is de-energized to the outputs during modes 5, 7, 13 and 15. Modes 2, 4, 6, 8, 10, 12, 14 and 16... are the partial resonant modes and as evident from Fig. 14, they make up only a very small fraction of the link cycle time. The various operating modes are explained below. Mode 1 (Energizing): As discussed in section xyz, of the chosen phase pairs, the one having...

  10. Compensation of ac Stark shifts in optical magnetometry RID B-9041-2008 RID A-1272-2007

    E-Print Network [OSTI]

    Novikova, I.; Matsko, A. B.; Velichansky, V. L.; Scully, Marlan O.; Welch, George R.

    2001-01-01T23:59:59.000Z

    The ac Stark shift of the resonance frequency of the nonlinear magneto-optic effect (NMOE) results in a fundamental broadening of this resonance which limits the precision of optical magnetometry based on NMOE. We have studied the dependence...

  11. ACS | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTriWildcat 1 WindtheEnergySulfonate as aAAB AsiaABEEolicaSection Logo:ACS

  12. ACS Symposium Program

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76) (See the EnergyTAMANG, APIL. A Multilevel224th ACS

  13. Self-induced ac Stark shift in lasers

    SciTech Connect (OSTI)

    Gil, L.; Lippi, G. L. [Universite de Nice Sophia Antipolis, Institut Non Lineaire de Nice, and CNRS, UMR 6618 1361 Route des Lucioles, F-06560 Valbonne (France)

    2011-04-15T23:59:59.000Z

    The ac Stark effect is a well-known, well-established effect associated with the displacement of the atomic energy levels in the presence of an electromagnetic (e.m.) field. As the origin of the e.m. field is irrelevant, a self-induced ac Stark effect should be present in a laser. However, not only has this effect never been reported but it is not included in any laser model. Here, we show that a self-induced ac Stark shift does exist in the theoretical description of a two-level laser, provided that the reduced equations are derived not from the rotating-wave approximation, but from the full density matrix formulation. Interesting fundamental consequences are discussed and quantitative estimates of the self-induced frequency shift resulting from the laser field's ac Stark shift are obtained for a variety of lasers. We find that the effect is generally small but (at least in some cases) measurable and that the transfer of laser amplitude noise into frequency noise may play a role in future, ultrahigh-precision metrological applications.

  14. AC Resistance measuring instrument

    DOE Patents [OSTI]

    Hof, Peter J. (Richland, WA)

    1983-01-01T23:59:59.000Z

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument.

  15. AC resistance measuring instrument

    DOE Patents [OSTI]

    Hof, P.J.

    1983-10-04T23:59:59.000Z

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument. 8 figs.

  16. Free piston variable-stroke linear-alternator generator

    DOE Patents [OSTI]

    Haaland, Carsten M. (Dadeville, AL)

    1998-01-01T23:59:59.000Z

    A free-piston variable stroke linear-alternator AC power generator for a combustion engine. An alternator mechanism and oscillator system generates AC current. The oscillation system includes two oscillation devices each having a combustion cylinder and a flying turnbuckle. The flying turnbuckle moves in accordance with the oscillation device. The alternator system is a linear alternator coupled between the two oscillation devices by a slotted connecting rod.

  17. Free piston variable-stroke linear-alternator generator

    DOE Patents [OSTI]

    Haaland, C.M.

    1998-12-15T23:59:59.000Z

    A free-piston variable stroke linear-alternator AC power generator for a combustion engine is described. An alternator mechanism and oscillator system generates AC current. The oscillation system includes two oscillation devices each having a combustion cylinder and a flying turnbuckle. The flying turnbuckle moves in accordance with the oscillation device. The alternator system is a linear alternator coupled between the two oscillation devices by a slotted connecting rod. 8 figs.

  18. Absorption of ac fields in amorphous indium-oxide films

    SciTech Connect (OSTI)

    Ovadyahu, Z. [Racah Institute of Physics, the Hebrew University, Jerusalem 91904 (Israel)

    2014-08-20T23:59:59.000Z

    Absorption data from applied ac fields in Anderson-localized amorphous indium-oxide (In{sub x}O) films are shown to be frequency and disorder dependent. The absorption shows a roll-off at a frequency which is much lower than the electron-electron scattering rate of the material when it is in the diffusive regime. This is interpreted as evidence for discreteness of the energy spectrum of the deeply localized regime. This is consistent with recent many-body localization scenarios. As the metal-insulator transition is approached, the absorption shifts to higher frequencies. Comparing with the previously obtained results on the crystalline version of indium-oxide (In{sub 2}O{sub 3?x}) implies a considerably higher inelastic electron-phonon scattering rate in the amorphous material. The range over which the absorption versus frequency decreases may indicate that a wide distribution of localization length is a common feature in these systems.

  19. A Preliminary Experimental Study on Haptic Teleoperation of Mobile Robot with Variable Force Feedback Gain

    E-Print Network [OSTI]

    Ryu, Jee-Hwan

    industrial constructions, etc. In all these application examples human-robot interfaces play the key role and its application for e-mail:ildar.info@gmail.com e-mail:jhryu@kut.ac.kr e-mail:robot@dgist.ac.kr O Y XA Preliminary Experimental Study on Haptic Teleoperation of Mobile Robot with Variable Force

  20. Controller for controlling operation of at least one electrical load operating on an AC supply, and a method thereof

    DOE Patents [OSTI]

    Cantin, Luc (Baie Comeau, CA); Deschenes, Mario (Baie Comeau, CA); D'Amours, Mario (Sept Iles, CA)

    1995-08-15T23:59:59.000Z

    A controller is provided for controlling operation of at least one electrical load operating on an AC supply having a typical frequency, the AC supply being provided via power transformers by an electrical power distribution grid. The controller is associated with the load and comprises an input interface for coupling the controller to the grid, a frequency detector for detecting the frequency of the AC supply and producing a signal indicative of the frequency, memory modules for storing preprogrammed commands, a frequency monitor for reading the signal indicative of the frequency and producing frequency data derived thereof, a selector for selecting at least one of the preprogrammed commands with respect to the frequency data, a control unit for producing at least one command signal representative of the selected preprogrammed commands, and an output interface including a device responsive to the command signal for controlling the load. Therefore, the load can be controlled by means of the controller depending on the frequency of the AC supply.

  1. UEA Water Security Research Centre Climate Change and Variability Adaptation and Vulnerability

    E-Print Network [OSTI]

    Everest, Graham R

    UEA Water Security Research Centre Climate Change and Variability · Adaptation and Vulnerability · Transboundary Cooperation ­ Conflict · Irrigation Performance and Policy · River Basin Management · Water Allocation · Hydropolitics www.uea.ac.uk/watersecurity #12;The UEA Water Security Research Centre applies

  2. AVTA: Aerovironment AC Level 2 Charging System Testing Results...

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

    Aerovironment AC Level 2 - February 2012 More Documents & Publications AVTA: Clipper Creek AC Level 2 Charging System Testing Results AVTA: Eaton AC Level 2 Charging System...

  3. Cataclysmic Variables

    E-Print Network [OSTI]

    Robert Connon Smith

    2007-01-23T23:59:59.000Z

    Cataclysmic variables are binary stars in which a relatively normal star is transferring mass to its compact companion. This interaction gives rise to a rich range of behaviour, of which the most noticeable are the outbursts that give the class its name. Novae belong to the class, as do the less well known dwarf novae and magnetic systems. Novae draw their energy from nuclear reactions, while dwarf novae rely on gravity to power their smaller eruptions. All the different classes of cataclysmic variable can be accommodated within a single framework and this article will describe the framework, review the properties of the main types of system and discuss models of the outbursts and of the long-term evolution.

  4. FDF: Frequency Detection-Based Filtering of Scanning Worms

    E-Print Network [OSTI]

    Bahk, Saewoong

    FDF: Frequency Detection-Based Filtering of Scanning Worms Byungseung Kim and Saewoong Bahk School@korea.ac.kr Abstract-- In this paper, we propose a simple algorithm for detecting scanning worms with high detection characteristic of scanning worms from a monitored network. Its low complexity allows it to be used on any network

  5. Exchange 13/14 www.ed.ac.uk

    E-Print Network [OSTI]

    Herrmann, Samuel

    : Studyabroad@ed.ac.uk Outgoing Students: Sharyn Bennet Email: Erasmus.outgoing@ed.ac.uk Head of Study Abroad

  6. Quantum recurrence and fractional dynamic localization in ac-driven perfect state transfer Hamiltonians

    SciTech Connect (OSTI)

    Longhi, Stefano, E-mail: stefano.longhi@fisi.polimi.it

    2014-06-15T23:59:59.000Z

    Quantum recurrence and dynamic localization are investigated in a class of ac-driven tight-binding Hamiltonians, the Krawtchouk quantum chain, which in the undriven case provides a paradigmatic Hamiltonian model that realizes perfect quantum state transfer and mirror inversion. The equivalence between the ac-driven single-particle Krawtchouk Hamiltonian H{sup -hat} (t) and the non-interacting ac-driven bosonic junction Hamiltonian enables to determine in a closed form the quasi energy spectrum of H{sup -hat} (t) and the conditions for exact wave packet reconstruction (dynamic localization). In particular, we show that quantum recurrence, which is predicted by the general quantum recurrence theorem, is exact for the Krawtchouk quantum chain in a dense range of the driving amplitude. Exact quantum recurrence provides perfect wave packet reconstruction at a frequency which is fractional than the driving frequency, a phenomenon that can be referred to as fractional dynamic localization.

  7. ACS SYMPOSIUM SERIES 966 Rational Environmental

    E-Print Network [OSTI]

    Hammock, Bruce D.

    ACS SYMPOSIUM SERIES 966 Rational Environmental Management of Agrochemicals Risk Assessment-Bayo, Editor Chiha University Sponsored by the ACS Division of Agrochemicals American Chemical Society of agrochemicals : risk assessment, monitoring, and remedial action / Ivan R. Kennedy, editor. ..[et al

  8. Cyclic strain hardening of nanocrystalline nickel B. Moser a,b,*, T. Hanlon a,c

    E-Print Network [OSTI]

    Suresh, Subra

    Cyclic strain hardening of nanocrystalline nickel B. Moser a,b,*, T. Hanlon a,c , K.S. Kumar d , S strain hardening and frequency-dependent fatigue life in electrodeposited nanocrystalline Ni subjected. All rights reserved. Keywords: Nanocrystalline materials; Nickel; Low cycle fatigue; Fracture; Cyclic

  9. Low Frequency Architecture for Multi-Lamp CCFL Systemswith Capacitive Ignition

    E-Print Network [OSTI]

    Low Frequency Architecture for Multi-Lamp CCFL Systemswith Capacitive Ignition Monm Doshi (I-0425 regan.zane@colorado.edu Absfruci-This paper presents a low frequency architecture for driving parallel to the architecture is a proposed capacitive coupling approach for ac lamp ignition. The system consists of a single

  10. Web https://ms.ecc.utokyo.ac.jp/ (POP) popd.ecc.utokyo.ac.jp

    E-Print Network [OSTI]

    Katsumoto, Shingo

    ; 2 233 #12; (POP) popd.ecc.utokyo.ac.jp SSL995 (IMAP) imapd.ecc.utokyo.ac.jp SSL993 sbmsd.ecc.utokyo.ac.jp SSL465 @ 1. MailHosting D 2. 200MB 400MB 3. POPIMAP IMAPPOP 200MB400MB 3 233 #12;Thunderbird 3 4 233 #12; (POP) popd.ecc.utokyo.ac.jp SSL995 (IMAP) imapd.ecc.utokyo.ac.jp SSL993

  11. Association of adverse cardiovascular outcomes with weighted morphologic variability following non-ST-elevation acute coronary syndromes

    E-Print Network [OSTI]

    Sarker, Joyatee Mudra

    2010-01-01T23:59:59.000Z

    Patients who have had an acute coronary syndrome (ACS) are at a relatively high risk of having subsequent adverse cardiac events. Several electrocardiographic (ECG) measures such as heart rate variability, heart rate ...

  12. Measurements of AC Losses and Current Distribution in Superconducting Cables

    SciTech Connect (OSTI)

    Nguyen, Doan A [Los Alamos National Laboratory (LANL); Ashworth, Stephen P [Los Alamos National Laboratory (LANL); Duckworth, Robert C [ORNL; Carter, Bill [AMSC; Fleshler, Steven [AMER Superconductor Corp, Devens, MA 01434

    2011-01-01T23:59:59.000Z

    This paper presents our new experimental facility and techniques to measure ac loss and current distribution between the layers for High Temperature Superconducting (HTS) cables. The facility is powered with a 45 kVA three-phase power supply which can provide three-phase currents up to 5 kA per phase via high current transformers. The system is suitable for measurements at any frequency between 20 and 500 Hz to better understand the ac loss mechanisms in HTS cables. In this paper, we will report techniques and results for ac loss measurements carried out on several HTS cables with and without an HTS shielding layer. For cables without a shielding layer, care must be taken to control the effect of the magnetic fields from return currents on loss measurements. The waveform of the axial magnetic field was also measured by a small pick-up coil placed inside a two-layer cable. The temporal current distribution between the layers can be calculated from the waveform of the axial field.

  13. Analysis and design of a direct AC to AC matrix converter topology

    E-Print Network [OSTI]

    Choi, Sewan

    1992-01-01T23:59:59.000Z

    - eration. With the advent of the thyristor and more recent devices such as the Metal oxided semiconductor field effect transistor(MOSI'ET), the Insulated gate bipolar transistor(IGBT) and the MOS controlled thyristor(MCT), it has become increas- ingly... commutated devices such as OTO's, IGBT's, IVIOSFET's and MCT's. The principle of forced commutation is used in clirect ac to ac matrix converter which is described in the next section. B. Direct AC to AC Matrix Converter Direct ac to ac matrix converters...

  14. Bayesian latent variable modelling in studies of air pollution and health

    E-Print Network [OSTI]

    Burton, Geoffrey R.

    Bayesian latent variable modelling in studies of air pollution and health Duncan Lee, Gavin://www.bath.ac.uk/math-sci/BICS #12;Bayesian latent variable modelling in studies of air pollution and health. Duncan Lee (1), Gavin to air pollution on respiratory mortality in the elderly (aged 65 and above) in London, England, between

  15. Assessment of US electric vehicle programs with ac powertrains

    SciTech Connect (OSTI)

    Kevala, R.J. (Booz, Allen and Hamilton, Inc., Bethesda, MD (USA). Transportation Consulting Div.)

    1990-02-01T23:59:59.000Z

    AC powertrain technology is a promising approach to improving the performance of electric vehicles. Four major programs are now under way in the United States to develop ac powertrains: the Ford/General Electric single-shaft electric propulsion system (ETX-II), the Eaton dual-shaft electric propulsion system (DSEP), the Jet Propulsion Laboratories (JPL) integrated ac motor drive and recharge system, and the Massachusetts Institute of Technology (MIT) variable reluctance motor (VRM) drive. The JPL program is sponsored by EPRI; the other three programs are funded by the US Department of Energy. This preliminary assessment of the four powertrain programs focuses on potential performance, costs, safety, and commercial feasibility. Interviews with program personnel were supplemented by computer simulations of electric vehicle performance using the four systems. Each of the four powertrains appears superior to standard dc powertrain technology in terms of performance and weight. The powertrain technologies studied in this assessment are at varying degrees of technological maturity. One or more of the systems may be ready for incorporation into an advanced electric vehicle during the early 1990s. Each individual report will have a separate abstract. 5 refs., 37 figs., 29 tabs.

  16. Electric field and losses at AC self field mode in MF composites

    SciTech Connect (OSTI)

    Fukui, S.; Hlasnik, I.; Tsukamoto, O.; Amemiya, N. (Yokohama National Univ. (Japan)); Polak, M.; Kottman, P. (Slovak Academy of Science, Bratislava (Slovakia). Inst. of Electrical Engineering)

    1994-07-01T23:59:59.000Z

    Studies of the current-voltage characteristics of typical superconducting wires under static and dynamic conditions up to 50 Hz frequency have revealed much higher instantaneous local loss power densities in an external DC magnetic field than those which occur by magnetization in a transverse AC magnetic field. In this paper, the measured loss characteristics are compared with theoretical ones derived from the critical state model, and the self field AC loss are also estimated. Possible errors that can result by applying the critical state model are discussed.

  17. Frequency Measurement & Analysis Service

    E-Print Network [OSTI]

    Magee, Joseph W.

    NIST Frequency Measurement & Analysis Service #12;A Complete Solution To All Frequency Measurement & Calibration Problems The NIST Frequency Measurement and Analysis Service makes it easy to measure and calibrate any quartz, rubidium, or cesium frequency standard. All measurements are made automatically

  18. Processing of superconductive materials and high frequency

    SciTech Connect (OSTI)

    Smith, J.L.

    1987-01-01T23:59:59.000Z

    We do not know yet if superconductivity will become useful without refrigeration. Now, the superconductors are so different from copper that it is difficult to imagine replacing copper with such a brittle material. Superconductors conduct dc with no loss, ac with small losses, and microwaves in co-axial lines with almost no loss and with no dispersion from dc to the highest frequencies. They will probably allow us to close the gap between radio frequency and infrared optical transmission. Clearly your industry should know some things about where superconductivity may lead us and must consider whether the greater risk is to develop them or to let others try it. There are no easy answers yet.

  19. New nonlinear mechanisms of midlatitude atmospheric low-frequency variability

    E-Print Network [OSTI]

    and Atmospheric Research Utrecht, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands Abstract

  20. Variable Frequency Drives: Energy Savings and Impact on Motor Performance

    E-Print Network [OSTI]

    Petro, D.

    , and Pitfalls: Motor Acoustic Noise, Motor Heating. This paper is intended for plant engineers and maintenance personnel who have some practical experience with electrical and mechanical equipment, but are not VFD experts....

  1. Conserving Energy in Blast Freezers Using Variable Frequency Drives

    E-Print Network [OSTI]

    Kolbe, E.; Ling, Q.; Wheeler, G.

    2004-01-01T23:59:59.000Z

    University Portland Greg Wheeler Director Industrial Assessment Center ABSTRACT A stationary blast freezer processing 22 -lb cartons of sardines in 19,000 pound lots was modified to improve efficiency and to conserve energy. Baffles... of Portland showed readings to agree within 1%. The procedure for measuring velocity profiles was to position the operator in the blast-cell with doors closed, downstream of the pack, prior to opening the refrigeration valve. We thus assumed...

  2. Alamouti {yjdong, sky6174}@ccl.snu.ac.kr, jsno@snu.ac.kr, djshin@hanyang.ac.kr

    E-Print Network [OSTI]

    No, Jong-Seon

    @snu.ac.kr, djshin@hanyang.ac.kr (soft-decision-and-forward: SDF) . SDF . Alamouti , . (amplify-and-forward: AF) . , SDF AF . 1. . (source: S-decision-and-forward: SDF) . SDF R S phase, phase 1 phase 2 . Phase 1, S R D , phase 2 R D . , S D

  3. AC Transit | Department of Energy

    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 DataDepartment of Energy Your Density Isn't Your Destiny: The Future of1 A Strategic Framework for SMRA View from the-1AssessmentAC

  4. Frequency-and electric-field-dependent conductivity of single-walled carbon nanotube networks of varying density

    E-Print Network [OSTI]

    Gruner, George

    Frequency- and electric-field-dependent conductivity of single-walled carbon nanotube networks October 2007; published 20 February 2008 We present measurements of the frequency- and electric-field-dependent conductivity of single-walled car- bon nanotube SWCNT networks of various densities. The ac conductivity

  5. 82 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS, PART 1, VOL. 47, NO. 1, JANUARY 2000 Fig. 5. Output voltage waveform in the closed-loop dc-ac power inverter.

    E-Print Network [OSTI]

    Leuciuc, Adrian

    voltage waveform in the closed-loop dc-ac power inverter. Horizontal scale: 5 ms/div.; vertical scale: 0.2 V/div. Fig. 6. Bode plots of the closed-loop power inverter . Packard 4194A Network Analyzer, Bode that the -3-dB frequency was 205 Hz. IV. CONCLUSION This study demonstrates that a low-frequency dc-ac power

  6. ac magnetohydrodynamic microfluidic: Topics by E-print Network

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

    Keywords: electrokinetics, AC Electro-osmosis (ACEO); electrode polarization; microfluidics. 1. Introduction During recent years, AC electro-osmosis (ACEO) has emerged as a...

  7. ac iontophoretic transport: Topics by E-print Network

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

    Keywords: electrokinetics, AC Electro-osmosis (ACEO); electrode polarization; microfluidics. 1. Introduction During recent years, AC electro-osmosis (ACEO) has emerged as a...

  8. AVTA: Clipper Creek AC Level 2 Charging System Testing Results...

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

    electric vehicles. This research was conducted by Idaho National Laboratory. Clipper Creek AC Level 2 - February 2012 More Documents & Publications AVTA: Aerovironment AC Level...

  9. ac traction drives: 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...

  10. Eastern Frequency Response Study

    SciTech Connect (OSTI)

    Miller, N.W.; Shao, M.; Pajic, S.; D'Aquila, R.

    2013-05-01T23:59:59.000Z

    This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.

  11. www.accommodation.salford.ac.uk Accommodation

    E-Print Network [OSTI]

    Romano, Daniela

    sets out the main elements of good management practice. It covers health and safety, maintenancewww.accommodation.salford.ac.uk Accommodation Guide to University and University partner accommodation #12;32 www.accommodation.salford.ac.ukA guide to University and Partner accommodation Welcome

  12. Frequency selective infrared sensors

    SciTech Connect (OSTI)

    Davids, Paul; Peters, David W

    2014-11-25T23:59:59.000Z

    A frequency selective infrared (IR) photodetector having a predetermined frequency band. The exemplary frequency selective photodetector includes: a dielectric IR absorber having a first surface and a second surface substantially parallel to the first surface; an electrode electrically coupled to the first surface of the dielectric IR absorber; and a frequency selective surface plasmonic (FSSP) structure formed on the second surface of the dielectric IR absorber. The FSSP structure is designed to selectively transmit radiation in the predetermined frequency band that is incident on the FSSP structure substantially independent of the angle of incidence of the incident radiation on the FSSP structure.

  13. Frequency selective infrared sensors

    DOE Patents [OSTI]

    Davids, Paul; Peters, David W

    2013-05-28T23:59:59.000Z

    A frequency selective infrared (IR) photodetector having a predetermined frequency band. The exemplary frequency selective photodetector includes: a dielectric IR absorber having a first surface and a second surface substantially parallel to the first surface; an electrode electrically coupled to the first surface of the dielectric IR absorber; and a frequency selective surface plasmonic (FSSP) structure formed on the second surface of the dielectric IR absorber. The FSSP structure is designed to selectively transmit radiation in the predetermined frequency band that is incident on the FSSP structure substantially independent of the angle of incidence of the incident radiation on the FSSP structure.

  14. Understanding Inertial and Frequency Response of Wind Power Plants: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Gevorgian, V.; Singh, M.; Santoso, S.

    2012-07-01T23:59:59.000Z

    The objective of this paper is to analyze and quantify the inertia and frequency responses of wind power plants with different wind turbine technologies (particularly those of fixed speed, variable slip with rotor-resistance controls, and variable speed with vector controls).

  15. (5202) e-mail: takasaki.midori@ocha.ac.jp (5201) e-mail: iwasaki.ogihara.chizuru@ocha.ac.jp

    E-Print Network [OSTI]

    Matsuzaki, Katsuhiko

    .chika@ocha.ac.jp = (5215) e-mail: schwartz.laure@ocha.ac.jp (5182) e-mail: kanda.yutsuki@ocha.ac.jp (5181) e

  16. Radio frequency detection assembly and method for detecting radio frequencies

    DOE Patents [OSTI]

    Cown, Steven H. (Rigby, ID); Derr, Kurt Warren (Idaho Falls, ID)

    2010-03-16T23:59:59.000Z

    A radio frequency detection assembly is described and which includes a radio frequency detector which detects a radio frequency emission produced by a radio frequency emitter from a given location which is remote relative to the radio frequency detector; a location assembly electrically coupled with the radio frequency detector and which is operable to estimate the location of the radio frequency emitter from the radio frequency emission which has been received; and a radio frequency transmitter electrically coupled with the radio frequency detector and the location assembly, and which transmits a radio frequency signal which reports the presence of the radio frequency emitter.

  17. Beat Frequency Modulation of T Tauri Accretion Rates

    E-Print Network [OSTI]

    K. W. Smith; I. A. Bonnell; G. F. Lewis

    1995-04-10T23:59:59.000Z

    A general model of magnetically controlled accretion onto T Tauri stars is presented. In this model the magnetic field is oriented arbitrarily in relation to the star's rotation axis. The resultant interplay between the magnetic field and accretion disc causes a variable accretion rate. The dominant timescale of this variability is the beat frequency between the stellar rotation frequency and the orbital frequency at the magnetosphere boundary. This model is analogous to that developed to explain quasi-periodic oscillations in low-mass X-ray binaries.

  18. www.mmu.ac.uk/careers Careers & Employability Service

    E-Print Network [OSTI]

    .mmu.ac.uk/careers Identifying courses · www.prospects.ac.uk/search_courses.htm · www.jobs.ac.uk · www.Findamasters.com · www.mmu.ac.uk/careers PG Professional/Vocational courses: Courses to allow you to enter certain professions Courses involve lectures for the first two terms then a research project for the final term (often finishing after

  19. Frequency Response Analysis Tool

    SciTech Connect (OSTI)

    Etingov, Pavel V.; Kosterev, Dmitry; Dai, T.

    2014-12-31T23:59:59.000Z

    Frequency response has received a lot of attention in recent years at the national level, which culminated in the development and approval of North American Electricity Reliability Corporation (NERC) BAL-003-1 Frequency Response and Frequency Bias Setting Reliability Standard. This report is prepared to describe the details of the work conducted by Pacific Northwest National Laboratory (PNNL) in collaboration with the Bonneville Power Administration and Western Electricity Coordinating Council (WECC) Joint Synchronized Information Subcommittee (JSIS) to develop a frequency response analysis tool (FRAT). The document provides the details on the methodology and main features of the FRAT. The tool manages the database of under-frequency events and calculates the frequency response baseline. Frequency response calculations are consistent with frequency response measure (FRM) in NERC BAL-003-1 for an interconnection and balancing authority. The FRAT can use both phasor measurement unit (PMU) data, where available, and supervisory control and data acquisition (SCADA) data. The tool is also capable of automatically generating NERC Frequency Response Survey (FRS) forms required by BAL-003-1 Standard.

  20. Low Frequency Transmission Final Project Report

    E-Print Network [OSTI]

    to HVDC transmission and conventional AC transmission in different configurations. The issue is quite

  1. ICI Canceling Space-Frequency Block Code for MISO-OFDM in Fast Fading Channels

    E-Print Network [OSTI]

    Lee, Yong Hoon

    ICI Canceling Space-Frequency Block Code for MISO-OFDM in Fast Fading Channels Jae Yeun Yun, Eui}@ee.kaist.ac.kr Abstract-- An intercarrier interference (ICI) canceling technique for multiple-input single-output (MISO) at the receiver for multiple-input single-output (MISO) systems. The code design is based on the approximated

  2. Resonant frequency detection and adjustment method for a capacitive transducer with differential transformer bridge

    SciTech Connect (OSTI)

    Hu, M.; Bai, Y. Z., E-mail: abai@mail.hust.edu.cn; Zhou, Z. B., E-mail: zhouzb@mail.hust.edu.cn; Li, Z. X.; Luo, J. [MOE Key Laboratory of Fundamental Physical Quantities Measurement, School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)] [MOE Key Laboratory of Fundamental Physical Quantities Measurement, School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-05-15T23:59:59.000Z

    The capacitive transducer with differential transformer bridge is widely used in ultra-sensitive space accelerometers due to their simple structure and high resolution. In this paper, the front-end electronics of an inductive-capacitive resonant bridge transducer is analyzed. The analysis result shows that the performance of this transducer depends upon the case that the AC pumping frequency operates at the resonance point of the inductive-capacitive bridge. The effect of possible mismatch between the AC pumping frequency and the actual resonant frequency is discussed, and the theoretical analysis indicates that the output voltage noise of the front-end electronics will deteriorate by a factor of about 3 due to either a 5% variation of the AC pumping frequency or a 10% variation of the tuning capacitance. A pre-scanning method to determine the actual resonant frequency is proposed followed by the adjustment of the operating frequency or the change of the tuning capacitance in order to maintain expected high resolution level. An experiment to verify the mismatching effect and the adjustment method is provided.

  3. Stabilized radio frequency quadrupole

    DOE Patents [OSTI]

    Lancaster, Henry D. (Orinda, CA); Fugitt, Jock A. (Berkeley, CA); Howard, Donald R. (Danville, CA)

    1984-01-01T23:59:59.000Z

    A long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator.

  4. Microfabricated ion frequency standard

    SciTech Connect (OSTI)

    Schwindt, Peter (Albuquerque, NM); Biedermann, Grant (Albuquerque, NM); Blain, Matthew G. (Albuquerque, NM); Stick, Daniel L. (Albuquerque, NM); Serkland, Darwin K. (Albuquerque, NM); Olsson, III, Roy H. (Albuquerque, NM)

    2010-12-28T23:59:59.000Z

    A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

  5. CONTRIBUTED Variability Effects in Graphene

    E-Print Network [OSTI]

    -Bionics, Chinese Academy of Sciences, Suzhou 215123, China (e-mail: yzhang5@lbl.gov; ygzhang2012@sinano.ac.cn). X

  6. Three phase AC motor controller

    DOE Patents [OSTI]

    Vuckovich, Michael (Elizabeth, PA); Wright, Maynard K. (Bethel Park, PA); Burkett, John P. (South Huntington Township, Westmoreland County, PA)

    1984-03-20T23:59:59.000Z

    A motor controller for a three phase AC motor (10) which is adapted to operate bidirectionally from signals received either from a computer (30) or a manual control (32). The controller is comprised of digital logic circuit means which implement a forward and reverse command signal channel (27, 29) for the application of power through the forward and reverse power switching relays (16, 18, 20, 22). The digital logic elements are cross coupled to prevent activation of both channels simultaneously and each includes a plugging circuit (65, 67) for stopping the motor upon the removal of control signal applied to one of the two channels (27, 29) for a direction of rotation desired. Each plugging circuit (65, 67) includes a one-shot pulse signal generator (88, 102) which outputs a single pulse signal of predetermined pulsewidth which is adapted to inhibit further operation of the application of power in the channel which is being activated and to apply a reversal command signal to the other channel which provides a reversed phase application of power to the motor for a period defined by the pulse-width output of the one-shot signal generator to plug the motor (10) which will then be inoperative until another rotational command signal is applied to either of the two channels.

  7. THE CARINA PROJECT. VI. THE HELIUM-BURNING VARIABLE STARS

    SciTech Connect (OSTI)

    Coppola, G.; Marconi, M.; Ripepi, V.; Dall'Ora, M.; Musella, I. [INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli (Italy); Stetson, P. B. [Dominion Astrophysical Observatory, NRC-Herzberg, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Bono, G.; Buonanno, R. [Dipartimento di Fisica-Universita di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Roma (Italy); Fabrizio, M. [INAF-Osservatorio Astronomico di Collurania, via M. Maggini, I-64100 Teramo (Italy); Ferraro, I.; Iannicola, G.; Pulone, L. [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monte Porzio Catone (Italy); Fiorentino, G. [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Monelli, M. [Instituto de Astrofisica de Canarias, Calle Via Lactea s/n, E-38205 La Laguna, Tenerife (Spain); Nonino, M. [INAF-Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, I-40131 Trieste (Italy); Thevenin, F. [Universite de Nice-Sophia Antipolis, Lab. Lagrange, UMR 7293, Observatoire de la Cote dAzur, BP 4229, F-06304 Nice (France); Walker, A. R., E-mail: coppola@na.astro.it [Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena (Chile)

    2013-09-20T23:59:59.000Z

    We present new optical (BVI) time-series data for the evolved variable stars in the Carina dwarf spheroidal galaxy. The quality of the data and the observing strategy allowed us to identify 14 new variable stars. Eight out of the 14 are RR Lyrae (RRL) stars, 4 are Anomalous Cepheids (ACs), and 2 are geometrical variables. Comparison of the period distribution for the entire sample of RRLs with similar distributions in nearby dwarf spheroidal galaxies and in the Large Magellanic Cloud indicates that the old stellar populations in these systems share similar properties. This finding is also supported by the RRL distribution in the Bailey diagram. On the other hand, the period distribution and the Bailey diagram of ACs display significant differences among the above stellar systems. This evidence suggests that the properties of intermediate-age stellar populations might be affected both by environmental effects and structural parameters. We use the BV Period-Wesenheit (PW) relation of RRLs together with evolutionary prescriptions and find a true distance modulus of 20.09 {+-} 0.07 (intrinsic) {+-} 0.1 (statistical) mag that agrees quite well with similar estimates available in the literature. We identified four peculiar variables. Taking into account their position in the Bailey diagram and in the BV PW relation, two of them (V14 and V149) appear to be candidate ACs, while two (V158 and V182) might be peculiar RRLs. In particular, the variable V158 has a period and a V-band amplitude very similar to the low-mass RRL-RRLR-02792-recently identified by Pietrzynski et al. in the Galactic bulge.

  8. Graphene Frequency Multipliers

    E-Print Network [OSTI]

    Wang, Han

    In this letter, the ambipolar transport properties of graphene flakes have been used to fabricate full-wave signal rectifiers and frequency-doubling devices. By correctly biasing an ambipolar graphene field-effect transistor ...

  9. Variability of Behaviour in Electricity Load Profile Clustering; Who Does Things at the

    E-Print Network [OSTI]

    Aickelin, Uwe

    Variability of Behaviour in Electricity Load Profile Clustering; Who Does Things at the Same Time://ima.ac.uk/dent 2 The James Hutton Institute, Aberdeen, UK Abstract. UK electricity market changes provide opportunities to alter households' electricity usage patterns for the benefit of the overall elec- tricity

  10. Comparing Images Under Variable Illumination David W. Jacobs Peter N. Belhumeur Ronen Basri

    E-Print Network [OSTI]

    Yang, Junfeng

    -based vision an effort is made to represent the set of all images an object can produce, either by sam- plingComparing Images Under Variable Illumination David W. Jacobs Peter N. Belhumeur Ronen Basri NEC@wisdom.weizmann.ac.il belhumeur@yale.edu Abstract We consider the problem of determining whether two images come from different

  11. Magnetostrictive materials and method for improving AC characteristics in same

    DOE Patents [OSTI]

    Pulvirenti, Patricia P. (Chicago, IL); Jiles, David C. (Ames, IA)

    2001-08-14T23:59:59.000Z

    The present invention provides Terfenol-D alloys ("doped" Terfenol) having optimized performances under the condition of time-dependent magnetic fields. In one embodiment, performance is optimized by lowering the conductivity of Terfenol, thereby improving the frequency response. This can be achieved through addition of Group III or IV elements, such as Si and Al. Addition of these types of elements provides scattering sites for conduction electrons, thereby increasing resistivity by 125% which leads to an average increase in penetration depth of 80% at 1 kHz and an increase in energy conversion efficiency of 55%. The permeability of doped Terfenol remains constant over a wider frequency range as compared with undoped Terfenol. These results demonstrate that adding impurities, such as Si and Al, are effective in improving the ac characteristics of Terfenol. A magnetoelastic Gruneisen parameter, .gamma..sub.me, has also been derived from the thermodynamic equations of state, and provides another means by which to characterize the coupling efficiency in magnetostrictive materials on a more fundamental basis.

  12. Ashtekar's variables without spin

    E-Print Network [OSTI]

    Thomas Schucker

    2009-06-26T23:59:59.000Z

    Ashtekar's variables are shown to arise naturally from a 3+1 split of general relativity in the Einstein-Cartan formulation. Thereby spinors are exorcised.

  13. Robust Timing Synchronization for AC-OFDM Based Optical Wireless Communications

    E-Print Network [OSTI]

    Ranjha, Bilal A; Kavehrad, Mohsen; Deng, Peng

    2015-01-01T23:59:59.000Z

    Visible light communications (VLC) have recently attracted a growing interest and can be a potential solution to realize indoor wireless communication with high bandwidth capacity for RF-restricted environments such as airplanes and hospitals. Optical based orthogonal frequency division multiplexing (OFDM) systems have been proposed in the literature to combat multipath distortion and intersymbol interference (ISI) caused by multipath signal propagation. In this paper, we present a robust timing synchronization scheme suitable for asymmetrically clipped (AC) OFDM based optical intensity modulated direct detection (IM/DD) wireless systems. Our proposed method works perfectly for ACO-OFDM, Pulse amplitude modulated discrete multitone (PAM-DMT) and discrete Hartley transform (DHT) based optical OFDM systems. In contrast to existing OFDM timing synchronization methods which are either not suitable for AC OFDM techniques due to unipolar nature of output signal or perform poorly, our proposed method is suitable for...

  14. Cinema 16 Collection / A.C. Killip (collector)

    E-Print Network [OSTI]

    Handy, Todd C.

    Cinema 16 Collection / A.C. Killip (collector) University of British Columbia Archives #12;Table;Collection Description Cinema 16 Collection / A.C. Killip (collector). ­ 1961-1970. 1.5 cm of textual records

  15. WASEDAUNIVERSITY http://www.sci.waseda.ac.jp

    E-Print Network [OSTI]

    Kasahara, Hironori

    ://www.cse.sci.waseda.ac.jp/ http://www.ase.sci.waseda.ac.jp/ http://www.waseda.jp/ips/ http://www.waseda.jp/weee/ INDEX 2014 5

  16. EXTENSION OF THE MAXIMUM POWER REGION OF DOUBLY-SALIENT VARIABLE RELUCTANCE MOTORS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -Salient Variable Reluctance Motors (DSVRM) has been investigated and developed for variable-speed drives during, variable-frequency generators, wind wheels, machine tools, etc.). In these applications, it is generally necessary to operate in a regime of a high speed ux-weakening (zone of maximum constant power), for a better

  17. THE ACS NEARBY GALAXY SURVEY TREASURY. III. CEPHEIDS IN THE OUTER DISK OF M81

    SciTech Connect (OSTI)

    McCommas, Les P.; Williams, Benjamin F.; Dalcanton, Julianne J.; Davis, Matthew R. [Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195 (United States); Yoachim, Peter [Department of Astronomy and McDonald Observatory, University of Texas, Austin, TX 78712 (United States); Dolphin, Andrew E. [Raytheon Corporation, 870 Winter Street Waltham, MA 02451 (United States)], E-mail: lmccomma@astro.washington.edu, E-mail: jd@astro.washington.edu, E-mail: ben@astro.washington.edu, E-mail: mrdavis@astro.washington.edu, E-mail: yoachim@astro.as.utexas.edu, E-mail: adolphin@ratheon.com

    2009-06-15T23:59:59.000Z

    The ACS Nearby Galaxy Survey Treasury (ANGST) has acquired deep ACS imaging of a field in the outer disk of the large spiral galaxy M81. These data were obtained over a total of 20 Hubble Space Telescope orbits, providing a baseline long enough to reliably identify Cepheid variable stars in the field. Fundamental mode and first overtone types have been distinguished through comparative fits with corresponding Cepheid light curve templates derived from principal component analysis of confirmed Cepheids in the Large Magellanic Cloud (LMC), Small Magellanic Cloud, and Milky Way. A distance modulus of 27.78 {+-} 0.05 {sub r} {+-} 0.14 {sub s} with a corresponding distance of 3.60 {+-} 0.23 Mpc has been calculated from a sample of 11 fundamental mode and two first overtone Cepheids (assuming an LMC distance modulus of {mu}{sub LMC} = 18.41 {+-} 0.10 {sub r} {+-} 0.13 {sub s})

  18. Interrelationship of variables concerned in a swine testing program

    E-Print Network [OSTI]

    Barbosa, Antonio Stockler

    1960-01-01T23:59:59.000Z

    '~. ~ - sort'. : ?. 1 carr, , l: t" cna (cxlcu- lated ';" t~. a !. n-rs) c:ana lanai sad nonsi, nific. "nt in;. . ll nhanas ax I he (ac~in- r" . ii d ~ The rross correlations ind ic;. tad. , ':h. ". . t I;ha older ai s nt th. b. . 'nnin; ~" the t'-t ccnsuma...IViT', -". I%X'. TXGN'"FiXP GP VARIABLY" C~ AC". , WT", i' XB' h;=, BXMi, T. ;GTZ% ~HGG~s ANTG)MG GTGCJiL-". H BARHGGA A Thoeie b7 , ". ubmitted to the Graduate school of tho ~g i Aglcultuxal anC Hechnrd. cnl College of Tezaa ln y ~ ~&ia1...

  19. STATE OF CALIFORNIA DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE

    E-Print Network [OSTI]

    STATE OF CALIFORNIA DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE CEC-MECH-14A (Revised 08/09) CALIFORNIA ENERGY COMMISSION CERTIFICATE OF ACCEPTANCE MECH-14A NA7.5.13 Distributed Energy Storage DX AC DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE CEC-MECH-14A (Revised 08/09) CALIFORNIA ENERGY COMMISSION

  20. www.pet.hw.ac.uk 1 Private and Confidential

    E-Print Network [OSTI]

    Painter, Kevin

    www.pet.hw.ac.uk 1 Private and Confidential Application for MSc Courses - Supplementary Information of Exam Grade Attained Subjects taken at `O' level or equivalent with grades #12;www.pet.hw.ac.uk 2 of principal & subsidiary subjects Please leave blank for Institute Use #12;www.pet.hw.ac.uk 3 Employment Dates

  1. www.strath.ac.uk THIS IS YOUR

    E-Print Network [OSTI]

    Mottram, Nigel

    Building Lorna Bennet SBS Exchange Co-ordinator Michele French SBS Exchange Secretary 01 | Contents 03 Building erkan.oterkus@strath.ac.uk Lorna Bennet Strathclyde Business School Level 2, Sir William Duncan Building lorna.bennet@strath.ac.uk www.strath.ac.uk | 06 #12;Key Dates www

  2. Research by BNL investigators was performed under the auspices of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886.

    E-Print Network [OSTI]

    of Energy under Contract No. DE-AC02-98CH10886. BNL-63565 THE PHOTOCHEMICAL FORMATION OF OZONE: RESULTS FROM UV measurements from an Eppley radiometer. For j(NO2) levels greater than 0.005 s-1 the gross O3 production rate observed in the air masses passing the site averaged 38 ppbvh-1 , but were highly variable

  3. Distinctly Ambitious www.hw.ac.uk

    E-Print Network [OSTI]

    Painter, Kevin

    , Duncan Hand at the James Watt Institute for High Value Manufacturing led a team to apply laser-based manufacturing processes to the production of dental products. The project led to the development of a laserDistinctly Ambitious www.hw.ac.uk Laser Machining #12;Cutting-edge engineering technology for laser

  4. Physics and contentswww.manchester.ac.uk

    E-Print Network [OSTI]

    engineering, science and bioscience research councils. As a postgraduate student at The UniversityPhysics and Astronomy #12;contentswww.manchester.ac.uk 12 The University of Manchester 2 Physics to be part of The University of Manchester. If you choose to be a postgraduate student here you can join us

  5. Four-Channel Differential AC Amplifier

    E-Print Network [OSTI]

    Kleinfeld, David

    to amplify cellular neurophysiological signals in applications requiring high gain, high input impedance, low://www.a-msystems.com General Description Instrument Features The Four-Channel Differential AC Amplifier Model 1700 is designed noise, high common-mode rejection, and powerline interference rejection. Typical applications include

  6. AC Losses of Prototype HTS Transmission Cables

    SciTech Connect (OSTI)

    Demko, J.A.; Dresner, L.; Hughey, R.L.; Lue, J.W.; Olsen, S.K.; Sinha, U.; Tolbert, J.C.

    1998-09-13T23:59:59.000Z

    Since 1995 Southwire Company and Oak Ridge National Laboratory (ORNL) have jointly designed, built, and tested nine, l-m long, high temperature superconducting (HTS) transmission cable prototypes. This paper summarizes the AC loss measurements of five of the cables not reported elsewhere, and compares the losses with each other and with theory developed by Dresner. Losses were measured with both a calorimetric and an electrical technique. Because of the broad resistive transition of the HTS tapes, the cables can be operated stably beyond their critical currents. The AC losses were measured in this region as well as below critical currents. Dresner's theory takes into account the broad resistive transition of the HTS tapes and calculates the AC losses both below and above the critical current. The two sets of AC 10SS data agree with each other and with the theory quite welL In particular, at low currents of incomplete penetration, the loss data agree with the theoretical prediction of hysteresis loss based on only the outer two Iayers carrying the total current.

  7. Frequency Control Performance Measurement and Requirements

    E-Print Network [OSTI]

    Illian, Howard F.

    2011-01-01T23:59:59.000Z

    DCS only measured low-frequency disturbances instead of bothlow- and high-frequency disturbances. The DCS requiredof the pre-disturbance frequency and the settling frequency.

  8. Impact of Salt Purity on Interfacial Water Organization Revealed by Conventional and Heterodyne-Detected Vibrational Sum Frequency

    E-Print Network [OSTI]

    Impact of Salt Purity on Interfacial Water Organization Revealed by Conventional and Heterodyne of the chosen salts and their solutions. This is true not only for the ACS grade salts but also vibrational sum frequency generation (VSFG) and heterodyne-detected VSFG (HD-VSFG) spectroscopy that salt

  9. Frequency dispersion of nonlinear response of thin superconducting films in the Berezinskii-Kosterlitz-Thouless state

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

    Dietrich, Scott; Bollinger, Anthony T.; Mayer, William; Byrnes, Sean; Vitkalov, Sergey; Sergeev, A.; Bozovic, Ivan

    2015-02-01T23:59:59.000Z

    The effects of microwave radiation on transport properties of atomically thin La2-xSrxCuO? films were studied in the 0.1-20 GHz frequency range. Resistance changes induced by microwaves were investigated at different temperatures (8–15 K) near the superconducting transition. A strong decrease of the nonlinear response is observed within a few GHz of a cutoff frequency ?cut ? 2GHz. The expected frequency dependence vastly underestimates the sharpness of this drop. Numerical simulations that assume ac response to follow dc V-I characteristics of the films reproduce well the low frequency behavior, but fail above ?cut. Thus, high-frequency radiation is much less effective inmore »inducing vortex-antivortex dissociation in the oscillating superconducting condensate.« less

  10. Measurement of the ac Stark shift with a guided matter-wave interferometer

    E-Print Network [OSTI]

    Deissler, B; Burke, J H T; Sackett, C A

    2007-01-01T23:59:59.000Z

    We demonstrate the effectiveness of a guided-wave Bose-Einstein condensate interferometer for practical measurements. Taking advantage of the large arm separations obtainable in our interferometer, the energy levels of the 87Rb atoms in one arm of the interferometer are shifted by a calibrated laser beam. The resulting phase shifts are used to determine the ac polarizability at a range of frequencies near and at the atomic resonance. The measured values are in good agreement with theoretical expectations. However, we observe a broadening of the transition near the resonance, an indication of collective light scattering effects. This nonlinearity may prove useful for the production and control of squeezed quantum states.

  11. Understanding Biomass Feedstock Variability

    SciTech Connect (OSTI)

    Kevin L. Kenney; William A. Smith; Garold L. Gresham; Tyler L. Westover

    2013-01-01T23:59:59.000Z

    If the singular goal of biomass logistics and the design of biomass feedstock supply systems is to reduce the per ton supply cost of biomass, these systems may very well develop with ultimate unintended consequences of highly variable and reduced quality biomass feedstocks. This paper demonstrates that due to inherent species variabilities, production conditions, and differing harvest, collection, and storage practices, this is a very real scenario that biomass producers and suppliers as well as conversion developers should be aware of. Biomass feedstock attributes of ash, carbohydrates, moisture, and particle morphology will be discussed. We will also discuss specifications for these attributes, inherent variability of these attributes in biomass feedstocks, and approaches and solutions for reducing variability for improving feedstock quality.

  12. Understanding Biomass Feedstock Variability

    SciTech Connect (OSTI)

    Kevin L. Kenney; Garold L. Gresham; William A. Smith; Tyler L. Westover

    2013-01-01T23:59:59.000Z

    If the singular goal of biomass logistics and the design of biomass feedstock supply systems is to reduce the per-ton supply cost of biomass, these systems may very well develop with ultimate unintended consequences of highly variable and reduced quality biomass feedstocks. This paper demonstrates that, due to inherent species variabilities, production conditions and differing harvest, collection and storage practices, this is a very real scenario that biomass producers and suppliers as well as conversion developers should be aware of. Biomass feedstock attributes of ash, carbohydrates, moisture and particle morphology will be discussed. We will also discuss specifications for these attributes, inherent variability of these attributes in biomass feedstocks, and approaches and solutions for reducing variability for improving feedstock quality.

  13. Self isolating high frequency saturable reactor

    DOE Patents [OSTI]

    Moore, James A. (Powell, TN)

    1998-06-23T23:59:59.000Z

    The present invention discloses a saturable reactor and a method for decoupling the interwinding capacitance from the frequency limitations of the reactor so that the equivalent electrical circuit of the saturable reactor comprises a variable inductor. The saturable reactor comprises a plurality of physically symmetrical magnetic cores with closed loop magnetic paths and a novel method of wiring a control winding and a RF winding. The present invention additionally discloses a matching network and method for matching the impedances of a RF generator to a load. The matching network comprises a matching transformer and a saturable reactor.

  14. High frequency reference electrode

    DOE Patents [OSTI]

    Kronberg, J.W.

    1994-05-31T23:59:59.000Z

    A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or halo' at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes. 4 figs.

  15. Bi-directional Current-fed Medium Frequency Transformer Isolated AC-DC Converter 

    E-Print Network [OSTI]

    Essakiappan, Somasundaram

    2011-08-08T23:59:59.000Z

    The use of high power converters has increased tremendously. Increased demand for transportation, housing and industrial needs means that more number of power converters interact with the utility power grid. These converters are non...

  16. Fault-tolerant Partial-resonant High-frequency AC-link Converters and Their Applications 

    E-Print Network [OSTI]

    Keyhani, Hamidreza

    2014-01-08T23:59:59.000Z

    Recently, the demand for high-power-density converters with high efficiency and enhanced reliability has increased considerably. To address this demand, this dissertation introduces several low, medium, and high power ...

  17. Bi-directional Current-fed Medium Frequency Transformer Isolated AC-DC Converter

    E-Print Network [OSTI]

    Essakiappan, Somasundaram

    2011-08-08T23:59:59.000Z

    and the development of new grid systems like HVDC transmission lines. The new solution proposed needs to incorporate methods for the renewable sources to receive power for monitoring and control, during periods of zero production. This calls for a power converter...

  18. Fault-tolerant Partial-resonant High-frequency AC-link Converters and Their Applications

    E-Print Network [OSTI]

    Keyhani, Hamidreza

    2014-01-08T23:59:59.000Z

    concerns in addition to voltage and current scalabilities. Moreover, fault tolerance of power converters is becoming more and more essential in many applications, such as aerospace and subsea systems. Fault tolerance involves the detection...

  19. Grid regulation services for energy storage devices based on grid frequency

    DOE Patents [OSTI]

    Pratt, Richard M; Hammerstrom, Donald J; Kintner-Meyer, Michael C.W.; Tuffner, Francis K

    2013-07-02T23:59:59.000Z

    Disclosed herein are representative embodiments of methods, apparatus, and systems for charging and discharging an energy storage device connected to an electrical power distribution system. In one exemplary embodiment, a controller monitors electrical characteristics of an electrical power distribution system and provides an output to a bi-directional charger causing the charger to charge or discharge an energy storage device (e.g., a battery in a plug-in hybrid electric vehicle (PHEV)). The controller can help stabilize the electrical power distribution system by increasing the charging rate when there is excess power in the electrical power distribution system (e.g., when the frequency of an AC power grid exceeds an average value), or by discharging power from the energy storage device to stabilize the grid when there is a shortage of power in the electrical power distribution system (e.g., when the frequency of an AC power grid is below an average value).

  20. Grid regulation services for energy storage devices based on grid frequency

    DOE Patents [OSTI]

    Pratt, Richard M; Hammerstrom, Donald J; Kintner-Meyer, Michael C.W.; Tuffner, Francis K

    2014-04-15T23:59:59.000Z

    Disclosed herein are representative embodiments of methods, apparatus, and systems for charging and discharging an energy storage device connected to an electrical power distribution system. In one exemplary embodiment, a controller monitors electrical characteristics of an electrical power distribution system and provides an output to a bi-directional charger causing the charger to charge or discharge an energy storage device (e.g., a battery in a plug-in hybrid electric vehicle (PHEV)). The controller can help stabilize the electrical power distribution system by increasing the charging rate when there is excess power in the electrical power distribution system (e.g., when the frequency of an AC power grid exceeds an average value), or by discharging power from the energy storage device to stabilize the grid when there is a shortage of power in the electrical power distribution system (e.g., when the frequency of an AC power grid is below an average value).

  1. THE ACS NEARBY GALAXY SURVEY TREASURY

    SciTech Connect (OSTI)

    Dalcanton, Julianne J.; Williams, Benjamin F.; Rosema, Keith; Gogarten, Stephanie M.; Christensen, Charlotte; Gilbert, Karoline; Hodge, Paul [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Seth, Anil C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Dolphin, Andrew [Raytheon, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Holtzman, Jon [Department of Astronomy, New Mexico State University, Box 30001, 1320 Frenger St., Las Cruces, NM 88003 (United States); Skillman, Evan D.; Weisz, Daniel [Department of Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455 (United States); Cole, Andrew [School of Mathematics and Physics, University of Tasmania, Hobart, Tasmania (Australia); Girardi, Leo [Osservatorio Astronomico di Padova - INAF, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy); Karachentsev, Igor D. [Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnji Arkhyz, Karachai-Circessia Republic 369167 (Russian Federation); Olsen, Knut [NOAO, National Optical Astronomy Observatory 950 N. Cherry Ave., Tucson, AZ 85719 (United States); Freeman, Ken [Mount Stromlo Observatory, Research School of Astronomy and Astrophysics, The Australian National Univ., ACT 0200 (Australia); Gallart, Carme [Inst. de AstrofIsica de Canarias, VIa Lactea, s/n, 38200 La Laguna, Tenerife (Spain); Harris, Jason [Steward Observatory, Univ. of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); De Jong, Roelof S. [Space Telescope Science Inst., 3700 San Martin Dr., Baltimore, MD 21218 (United States)], E-mail: jd@astro.washington.edu, E-mail: ben@astro.washington.edu, E-mail: krosema@astro.washington.edu, E-mail: stephanie@astro.washington.edu, E-mail: christensen@astro.washington.edu, E-mail: fabio@astro.washington.edu, E-mail: trq@astro.washington.edu, E-mail: aseth@cfa.harvard.edu (and others)

    2009-07-15T23:59:59.000Z

    The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D < 4 Mpc). The survey volume encompasses 69 galaxies in diverse environments, including close pairs, small and large groups, filaments, and truly isolated regions. The galaxies include a nearly complete range of morphological types spanning a factor of {approx}10{sup 4} in luminosity and star formation rate. The survey data consist of images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST), supplemented with archival data and new Wide Field Planetary Camera 2 (WFPC2) imaging taken after the failure of ACS. Survey images include wide field tilings covering the full radial extent of each galaxy, and single deep pointings in uncrowded regions of the most massive galaxies in the volume. The new wide field imaging in ANGST reaches median 50% completenesses of m {sub F475W} = 28.0 mag, m {sub F606W} = 27.3 mag, and m {sub F814W} = 27.3 mag, several magnitudes below the tip of the red giant branch (TRGB). The deep fields reach magnitudes sufficient to fully resolve the structure in the red clump. The resulting photometric catalogs are publicly accessible and contain over 34 million photometric measurements of >14 million stars. In this paper we present the details of the sample selection, imaging, data reduction, and the resulting photometric catalogs, along with an analysis of the photometric uncertainties (systematic and random), for both ACS and WFPC2 imaging. We also present uniformly derived relative distances measured from the apparent magnitude of the TRGB.

  2. ac-driven atomic quantum motor

    E-Print Network [OSTI]

    A. V. Ponomarev; S. Denisov; P. Hanggi

    2009-06-09T23:59:59.000Z

    We invent an ac-driven quantum motor consisting of two different, interacting ultracold atoms placed into a ring-shaped optical lattice and submerged in a pulsating magnetic field. While the first atom carries a current, the second one serves as a quantum starter. For fixed zero-momentum initial conditions the asymptotic carrier velocity converges to a unique non-zero value. We also demonstrate that this quantum motor performs work against a constant load.

  3. Algorithms for Incorporation of Dynamic Recovery in Estimating Frequency of Critical Station Blackout

    E-Print Network [OSTI]

    Rodi, Paul J.

    2012-07-16T23:59:59.000Z

    knowledge: and the ear of the wise seeketh instruction? (Proverbs 18:15) vi NOMENCLATURE 2CCF Common-Cause Doublet Failure 3CCF Common-Cause Triplet Failure AC Alternating Current CCF Common-Cause Failure CDF Core Damage Frequency................................................ 15 2.2 Example of How to Run MATLAB from the Editor Window ................... 29 2.3 Example of Change Folder Prompt in MATLAB....................................... 30 2.4 Example of Program Working and Running the Code...

  4. Direct amplitude detuning measurement with ac dipole

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

    White, S.; Maclean, E.; Tomás, R.

    2013-07-01T23:59:59.000Z

    In circular machines, nonlinear dynamics can impact parameters such as beam lifetime and could result in limitations on the performance reach of the accelerator. Assessing and understanding these effects in experiments is essential to confirm the accuracy of the magnetic model and improve the machine performance. A direct measurement of the machine nonlinearities can be obtained by characterizing the dependency of the tune as a function of the amplitude of oscillations (usually defined as amplitude detuning). The conventional technique is to excite the beam to large amplitudes with a single kick and derive the tune from turn-by-turn data acquired with beam position monitors. Although this provides a very precise tune measurement it has the significant disadvantage of being destructive. An alternative, nondestructive way of exciting large amplitude oscillations is to use an ac dipole. The perturbation Hamiltonian in the presence of an ac dipole excitation shows a distinct behavior compared to the free oscillations which should be correctly taken into account in the interpretation of experimental data. The use of an ac dipole for direct amplitude detuning measurement requires careful data processing allowing one to observe the natural tune of the machine; the feasibility of such a measurement is demonstrated using experimental data from the Large Hadron Collider. An experimental proof of the theoretical derivations based on measurements performed at injection energy is provided as well as an application of this technique at top energy using a large number of excitations on the same beam.

  5. Firewater system inadvertent actuation frequencies

    SciTech Connect (OSTI)

    Schroeder, J.A. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Eide, S.A. [Los Alamos Technical Associates, Inc., Albuquerque, NM (United States)

    1993-04-01T23:59:59.000Z

    This paper presents some recommended generic values for fire protection system inadvertent actuation frequencies. The frequencies are based on actual data from Department of Energy and commercial reactor plant facilities.

  6. Firewater system inadvertent actuation frequencies

    SciTech Connect (OSTI)

    Schroeder, J.A. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Eide, S.A. (Los Alamos Technical Associates, Inc., Albuquerque, NM (United States))

    1993-01-01T23:59:59.000Z

    This paper presents some recommended generic values for fire protection system inadvertent actuation frequencies. The frequencies are based on actual data from Department of Energy and commercial reactor plant facilities.

  7. POOL BOILING OF HIGH-FREQUENCY CONDUCTORS

    SciTech Connect (OSTI)

    Wright, S. E. (Spencer E.); Konecni, S. (Snezana); Ammerman, C. N. (Curtt N.); Sims, J. R. (James R.)

    2001-01-01T23:59:59.000Z

    This study presents development of a unique, powerful method for cooling high-frequency, AC conductors that can benefit end users of transformer windings, electrical machine windings, and magnet coils. This method of heat removal involves boiling a dielectric, fluorinert refrigerant that is in direct contact with litz wire conductors. A pool boiling test vessel is constructed, which provides for temperature control of the pool of fluorinert liquid. The test vessel is fitted with viewing ports so that the experiments are observed and studied with the aid of high-speed photography. Tests are performed on a variety of litz wire conductors. The boiling heat transfer coefficient is dependent on the conductor surface roughness. The size of the features on the conductor surface depends on the single-strand wire gage from which the conductor is constructed. All tests are performed with the conductors mounted horizontally. These tests are performed using a DC power supply. The results of these experiments will aid in the design of future cooling systems.

  8. Frequency-dependent electrostatic actuation in microfluidic MEMS.

    SciTech Connect (OSTI)

    Zavadil, Kevin Robert; Michalske, Terry A.; Sounart, Thomas L.

    2003-09-01T23:59:59.000Z

    Electrostatic actuators exhibit fast response times and are easily integrated into microsystems because they can be fabricated with standard IC micromachining processes and materials. Although electrostatic actuators have been used extensively in 'dry' MEMS, they have received less attention in microfluidic systems probably because of challenges such as electrolysis, anodization, and electrode polarization. Here we demonstrate that ac drive signals can be used to prevent electrode polarization, and thus enable electrostatic actuation in many liquids, at potentials low enough to avoid electrochemistry. We measure the frequency response of an interdigitated silicon comb-drive actuator in liquids spanning a decade of dielectric permittivities and four decades of conductivity, and present a simple theory that predicts the characteristic actuation frequency. The analysis demonstrates the importance of the native oxide on silicon actuator response, and suggests that the actuation frequency can be shifted by controlling the thickness of the oxide. For native silicon devices, actuation is predicted at frequencies less than 10 MHz, in electrolytes of ionic strength up to 100 mmol/L, and thus electrostatic actuation may be feasible in many bioMEMS and other microfluidic applications.

  9. Long-Term Wind Power Variability

    SciTech Connect (OSTI)

    Wan, Y. H.

    2012-01-01T23:59:59.000Z

    The National Renewable Energy Laboratory started collecting wind power data from large commercial wind power plants (WPPs) in southwest Minnesota with dedicated dataloggers and communication links in the spring of 2000. Over the years, additional WPPs in other areas were added to and removed from the data collection effort. The longest data stream of actual wind plant output is more than 10 years. The resulting data have been used to analyze wind power fluctuations, frequency distribution of changes, the effects of spatial diversity, and wind power ancillary services. This report uses the multi-year wind power data to examine long-term wind power variability.

  10. Variable nonlinear resistances

    E-Print Network [OSTI]

    Howard, James Edgar

    1955-01-01T23:59:59.000Z

    VARIETAL". NONLINEAR RESIS'IANCES A Thes1s JA'. 4ES EDGAR HOWARD as to style and content by Head Department January 1955 LIBRARY A 4 IS COLLEGE PF TEXAS VARIABLE NONLINEAR RESISTANCES A Thesis By JAMES EDGAR HOWARD Submitted...

  11. AUV {gslee, sbahk}@netlab.snu.ac.kr

    E-Print Network [OSTI]

    Bahk, Saewoong

    AUV , {gslee, sbahk}@netlab.snu.ac.kr Transmission Power Control in Cluster AUV (CH) AUV . 1 . 1. 2. 3 . AUV CH (Buoy

  12. University Policy No.: AC1145 Classification: Academic and Students

    E-Print Network [OSTI]

    Victoria, University of

    University Policy No.: AC1145 Classification: Academic and Students Approving Authority, interdisciplinary programs, divisions, and the library) will undergo a review every five to seven years

  13. University Policy No.: AC1150 Classification: Academic and Students

    E-Print Network [OSTI]

    Victoria, University of

    University Policy No.: AC1150 Classification: Academic and Students TEACHING, portfolios, references, library resources, laboratories and equipment) related to the subject matter

  14. WASEDAUNIVERSITY http://www.sci.waseda.ac.jp/research/

    E-Print Network [OSTI]

    Kasahara, Hironori

    ://www.ase.sci.waseda.ac.jp/ http://www.waseda.jp/ips/ http://www.waseda.jp/weee/ INDEX 2015 5 2 31http

  15. ac conductivity studies: Topics by E-print Network

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

    Last updated 8 Plotkin, Joshua B. 40 Study of supplementary controls for embedded HVDC links in a AC power system. Open Access Theses and Dissertations Summary: ??This...

  16. ac line conditioners: Topics by E-print Network

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

    of lines . ..2 Main Terasoma, Tomohide 83 Study of supplementary controls for embedded HVDC links in a AC power system. Open Access Theses and Dissertations Summary: ??This...

  17. ac losses: Topics by E-print Network

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

    23 24 25 Next Page Last Page Topic Index 1 Transport AC loss in high temperature superconducting coils University of Cambridge - Dspace Summary: 's electromagnetic properties and...

  18. Frequency mixing crystal

    DOE Patents [OSTI]

    Ebbers, Christopher A. (Livermore, CA); Davis, Laura E. (Manteca, CA); Webb, Mark (Salida, CA)

    1992-01-01T23:59:59.000Z

    In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmoic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X.sub.2 Y(NO.sub.3).sub.5 .multidot.2 nZ.sub.2 o wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

  19. High frequency nanotube oscillator

    DOE Patents [OSTI]

    Peng, Haibing (Houston, TX); Zettl, Alexander K. (Kensington, TX)

    2012-02-21T23:59:59.000Z

    A tunable nanostructure such as a nanotube is used to make an electromechanical oscillator. The mechanically oscillating nanotube can be provided with inertial clamps in the form of metal beads. The metal beads serve to clamp the nanotube so that the fundamental resonance frequency is in the microwave range, i.e., greater than at least 1 GHz, and up to 4 GHz and beyond. An electric current can be run through the nanotube to cause the metal beads to move along the nanotube and changing the length of the intervening nanotube segments. The oscillator can operate at ambient temperature and in air without significant loss of resonance quality. The nanotube is can be fabricated in a semiconductor style process and the device can be provided with source, drain, and gate electrodes, which may be connected to appropriate circuitry for driving and measuring the oscillation. Novel driving and measuring circuits are also disclosed.

  20. Frequency doubling crystals

    DOE Patents [OSTI]

    Wang, Francis (Danville, CA); Velsko, Stephan P. (Livermore, CA)

    1989-01-01T23:59:59.000Z

    A systematic approach to the production of frequency conversion crystals is described in which a chiral molecule has attached to it a "harmonic generating unit" which contributes to the noncentrosymmetry of the molecule. Certain preferred embodiments of such harmonic generating units include carboxylate, guanadyly and imidazolyl units. Certain preferred crystals include L-arginine fluoride, deuterated L-arginine fluoride, L-arginine chloride monohydrate, L-arginine acetate, dithallium tartrate, ammonium N-acetyl valine, N-acetyl tyrosine and N-acetyl hydroxyproline. Chemical modifications of the chiral molecule, such as deuteration, halogenation and controlled counterion substitution are available to adapt the dispersive properties of a crystal in a particular wavelength region.

  1. AVTA Voltec AC Level 1 and Level 2 Charging Systems Testing Results...

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

    Eaton AC Level 2 Charging System Testing Results AVTA: Aerovironment AC Level 2 Charging System Testing Results AVTA: Siemens-VersiCharge AC Level 2 Charging System Testing Results...

  2. ac hopping conduction: Topics by E-print Network

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

    FREQUENCY HOPPING SPREAD SPECTRUM VS. DIRECT SEQUENCE SPREAD SPECTRUM RAYLINK AND RAYTHEON OF THE PRECEEDING MATERIAL. 12;FREQUENCY HOPPING VS. DIRECT SEQUENCE Frequency...

  3. AC power | Princeton Plasma Physics Lab

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch >InternshipDepartmentNeutrino-Induced1 TEMPERATUREii ABSTRACT ThisAC

  4. Variable depth core sampler

    DOE Patents [OSTI]

    Bourgeois, P.M.; Reger, R.J.

    1996-02-20T23:59:59.000Z

    A variable depth core sampler apparatus is described comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member. 7 figs.

  5. Variable Crop Share Leases.

    E-Print Network [OSTI]

    Sartin, Marvin; Sammons, Ray

    1980-01-01T23:59:59.000Z

    )OC lAL45.7 173 1. 1224 Texas Agricultural Extension Service The Texas A&M University System Daniel C. Pfannstiel,Director colleg e Station, Texas / f , ' '~ :';,; ,,: ''': ~ " k , -~. _Variable _Crop Share _Leases ... Marvin... Sartin and Ray Sammons* Renting or leasing farmland is part of many modern farming operations and increases average farm size in U. S. agriculture. Economies of size are vitally import ant to farm operations as they strive to cope with the continuous...

  6. Method and apparatus for pulse width modulation control of an AC induction motor

    DOE Patents [OSTI]

    Geppert, Steven (Bloomfield Hills, MI); Slicker, James M. (Union Lake, MI)

    1984-01-01T23:59:59.000Z

    An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

  7. AVTA: Siemens-VersiCharge AC Level 2 Charging System Testing...

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

    Siemens-VersiCharge AC Level 2 Charging System Testing Results AVTA: Siemens-VersiCharge AC Level 2 Charging System Testing Results The Vehicle Technologies Office's Advanced...

  8. AVTA: GE Energy WattStation AC Level 2 Charging System Testing...

    Energy Savers [EERE]

    2012 More Documents & Publications AVTA: Aerovironment AC Level 2 Charging System Testing Results AVTA: GE Smart Grid Capable AC Level 2 Testing Results AVTA: Siemens-VersiCharge...

  9. IS ACTIVE REGION CORE VARIABILITY AGE DEPENDENT?

    SciTech Connect (OSTI)

    Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2012-12-10T23:59:59.000Z

    The presence of both steady and transient loops in active region cores has been reported from soft X-ray and extreme-ultraviolet observations of the solar corona. The relationship between the different loop populations, however, remains an open question. We present an investigation of the short-term variability of loops in the core of two active regions in the context of their long-term evolution. We take advantage of the nearly full Sun observations of STEREO and Solar Dynamics Observatory spacecraft to track these active regions as they rotate around the Sun multiple times. We then diagnose the variability of the active region cores at several instances of their lifetime using EIS/Hinode spectral capabilities. We inspect a broad range of temperatures, including for the first time spatially and temporally resolved images of Ca XIV and Ca XV lines. We find that the active region cores become fainter and steadier with time. The significant emission measure at high temperatures that is not correlated with a comparable increase at low temperatures suggests that high-frequency heating is viable. The presence, however, during the early stages, of an enhanced emission measure in the ''hot'' (3.0-4.5 MK) and ''cool'' (0.6-0.9 MK) components suggests that low-frequency heating also plays a significant role. Our results explain why there have been recent studies supporting both heating scenarios.

  10. Flexible generation of correlated photon pairs in different frequency ranges

    E-Print Network [OSTI]

    Fernando Oster; Christoph H Keitel; Mihai Macovei

    2012-05-30T23:59:59.000Z

    The feasibility to generate correlated photon pairs at variable frequencies is investigated. For this purpose, we consider the interaction of an off-resonant laser field with a two-level system possessing broken inversion symmetry. We show that the system generates non-classical photon pairs exhibiting strong intensity-intensity correlations. The intensity of the applied laser tunes the degree of correlation while the detuning controls the frequency of one of the photons which can be in the THz-domain. Furthermore, we observe the violation of a Cauchy-Schwarz inequality characterizing these photons.

  11. Analysis of Heart Rate Variability Using Time-Varying Filtering of Heart Transplanted Patients

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Analysis of Heart Rate Variability Using Time-Varying Filtering of Heart Transplanted Patients the heart rate variability (HRV), obtained by using the time-varying integral pulse frequency modulation (TVIPFM) which is well adapted to the exercise stress testing. We consider that the mean heart period

  12. Title of Document: INTERANNUAL VARIABILITY OF SEA SURFACE TEMPERATURE IN THE EASTERN

    E-Print Network [OSTI]

    Maryland at College Park, University of

    and therefore cloud cover and shortwave heating. In a parallel set of experiments, the low-frequency variability variability of SST in the EPWP. Interannual wind stress, shortwave radiation, and precipitation were used of the Tehuantepec gap winds was also shown to have a considerable effect on that of SST in the EPWP. Motivated

  13. Electrostatic coalescence system with independent AC and DC hydrophilic electrodes

    DOE Patents [OSTI]

    Hovarongkura, A. David (Arlington, VA); Henry, Jr., Joseph D. (Morgantown, WV)

    1981-01-01T23:59:59.000Z

    An improved electrostatic coalescence system is provided in which independent AC and DC hydrophilic electrodes are employed to provide more complete dehydration of an oil emulsion. The AC field is produced between an AC electrode array and the water-oil interface wherein the AC electrode array is positioned parallel to the interface which acts as a grounded electrode. The emulsion is introduced into the AC field in an evenly distributed manner at the interface. The AC field promotes drop-drop and drop-interface coalescence of the water phase in the entering emulsion. The continuous oil phase passes upward through the perforated AC electrode array and enters a strong DC field produced between closely spaced DC electrodes in which small dispersed droplets of water entrained in the continuous phase are removed primarily by collection at hydrophilic DC electrodes. Large droplets of water collected by the electrodes migrate downward through the AC electrode array to the interface. All phase separation mechanisms are utilized to accomplish more complete phase separation.

  14. business.cardiff.ac.uk Cardiff Business sChool

    E-Print Network [OSTI]

    Davies, Christopher

    business.cardiff.ac.uk Cardiff Business sChool MBa PrograMMes #12;01 business.cardiff.ac.ukWhy Cardiff Business School?01 Why Cardiff Business sChool? We are accredited by the Association to Advance Collegiate Schools of Business (AACSB International), a leading hallmark of business school excellence. We

  15. www.swansea.ac.uk/artsandhumanities Arts and Humanities

    E-Print Network [OSTI]

    Martin, Ralph R.

    dissertation or design a research project of their own (with 10,000 word report) which draws on issues Email: rhys.jones@swansea.ac.uk www.swansea.ac.uk/mediastudies/admissions - The Potter Guide to Higher relations, humanities, social science, computer science or related background. Professionals interested

  16. www.mmu.ac.uk/careers Careers & Employability Service

    E-Print Network [OSTI]

    ;www.mmu.ac.uk/careers Identifying courses · www.prospects.ac.uk/search_courses.htm · www: Courses to allow you to enter certain professions Courses that build your skills in a new area Examples · MRes (taught prep for further research) These usually involve lectures for the first two terms

  17. 3, 19151942, 2006 Longterm variability

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , 690041, Radio st., 7, Russia, 2 Delft University of Technology, Faculty of Civil Engineering, Section of about 2­3 yr and 6­8 yr that are ac- companied by statistically significant changes in such monthly, there is uncertainty in the question how climatic systems evolve. The potential reliability of climate models can

  18. North American Power Symposium NAPS, Cleveland, Ohio, October 1998, pp. 294 299. Fundamental Frequency Model of Uni ed Power Flow Controller

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    , modeling, fundamental frequency, stability, EMTP. I. Introduction Today's power systems are highly complex power systemresources without reduction in system stability and security. In the late 1980s, the Elec and operating power systems; the proposed concept is known as Flexi- ble AC Transmission Systems FACTS 1

  19. Personal Web Archive: E-mail: waka@iplab.cs.tsukuba.ac.jp, {shizuki,jiro}@cs.tsukuba.ac.jp

    E-Print Network [OSTI]

    Tanaka, Jiro

    Personal Web Archive: Web E-mail: waka@iplab.cs.tsukuba.ac.jp, {shizuki,jiro}@cs.tsukuba.ac.jp Web Web Web Web Web Web Personal Web Archive Personal Web Archive: Support System for Browsing the Versions of Web Page Ryota WAKAMATSU Buntarou SHIZUKI Jiro TANAKA Graduate School of Systems

  20. Safe-commutation principle for direct single-phase AC-AC converters for use in audio power

    E-Print Network [OSTI]

    and G, expressed as very low total harmonic distortion + noise (THD+N) levels and supplemented. SIngle Conversion stage AMplifier (SICAM) is the next im- portant evolutionary step in designing-stage AC-AC audio power amplifiers. As compared with the bridge commutation with load current or source

  1. Acoustic resonance frequency locked photoacoustic spectrometer

    DOE Patents [OSTI]

    Pilgrim, Jeffrey S.; Bomse, David S.; Silver, Joel A.

    2003-09-09T23:59:59.000Z

    A photoacoustic spectroscopy method and apparatus for maintaining an acoustic source frequency on a sample cell resonance frequency comprising: providing an acoustic source to the sample cell, the acoustic source having a source frequency; repeatedly and continuously sweeping the source frequency across the resonance frequency at a sweep rate; and employing an odd-harmonic of the source frequency sweep rate to maintain the source frequency sweep centered on the resonance frequency.

  2. Blazar Variability and Evolution in the GeV Regime

    E-Print Network [OSTI]

    Tsujimoto, S; Nishijima, K; Kodani, K

    2015-01-01T23:59:59.000Z

    One of the most important problem of the blazar astrophysics is to understand the physical origin of the blazar sequence. In this study, we focus on the GeV gamma-ray variability of blazars and evolution perspective we search the relation between the redshift and the variability amplitude of blazars for each blazar subclass. We analyzed the Fermi-LAT data of the TeV blazars and the bright AGNs (flux $\\geq$ 4$\\times10^{-9}$ cm$^{-2}$s$^{-1}$) selected from the 2LAC (the 2nd LAT AGN catalog) data base. As a result, we found a hint of the correlation between the redshift and the variability amplitude in the FSRQs. Furthermore the BL Lacs which have relatively lower peak frequency of the synchrotron radiation and relatively lower redshift, have a tendency to have a smaller variability amplitude.

  3. SECURING RADIO FREQUENCY IDENTIFICATION (RFID)

    E-Print Network [OSTI]

    business process for an organization; as a result, the security risks for RFID systems and the controls for an organization; as a result, the security risks for RFID systems and the controls available to address themMay 2007 SECURING RADIO FREQUENCY IDENTIFICATION (RFID) SYSTEMS SECURING RADIO FREQUENCY

  4. Stabilized radio-frequency quadrupole

    DOE Patents [OSTI]

    Lancaster, H.D.; Fugitt, J.A.; Howard, D.R.

    1982-09-29T23:59:59.000Z

    A long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator.

  5. Variable Valve Actuation

    SciTech Connect (OSTI)

    Jeffrey Gutterman; A. J. Lasley

    2008-08-31T23:59:59.000Z

    Many approaches exist to enable advanced mode, low temperature combustion systems for diesel engines - such as premixed charge compression ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or other HCCI-like combustion modes. The fuel properties and the quantity, distribution and temperature profile of air, fuel and residual fraction in the cylinder can have a marked effect on the heat release rate and combustion phasing. Figure 1 shows that a systems approach is required for HCCI-like combustion. While the exact requirements remain unclear (and will vary depending on fuel, engine size and application), some form of substantially variable valve actuation is a likely element in such a system. Variable valve actuation, for both intake and exhaust valve events, is a potent tool for controlling the parameters that are critical to HCCI-like combustion and expanding its operational range. Additionally, VVA can be used to optimize the combustion process as well as exhaust temperatures and impact the after treatment system requirements and its associated cost. Delphi Corporation has major manufacturing and product development and applied R&D expertise in the valve train area. Historical R&D experience includes the development of fully variable electro-hydraulic valve train on research engines as well as several generations of mechanical VVA for gasoline systems. This experience has enabled us to evaluate various implementations and determine the strengths and weaknesses of each. While a fully variable electro-hydraulic valve train system might be the 'ideal' solution technically for maximum flexibility in the timing and control of the valve events, its complexity, associated costs, and high power consumption make its implementation on low cost high volume applications unlikely. Conversely, a simple mechanical system might be a low cost solution but not deliver the flexibility required for HCCI operation. After modeling more than 200 variations of the mechanism it was determined that the single cam design did not have enough flexibility to satisfy three critical OEM requirements simultaneously, (maximum valve lift variation, intake valve opening timing and valve closing duration), and a new approach would be necessary. After numerous internal design reviews including several with the OEM a dual cam design was developed that had the flexibility to meet all motion requirements. The second cam added complexity to the mechanism however the cost was offset by the deletion of the electric motor required in the previous design. New patent applications including detailed drawings and potential valve motion profiles were generated and alternate two cam designs were proposed and evaluated for function, cost, reliability and durability. Hardware was designed and built and testing of sample hardware was successfully completed on an engine test stand. The mechanism developed during the course of this investigation can be applied by Original Equipment Manufacturers, (OEM), to their advanced diesel engines with the ultimate goal of reducing emissions and improving fuel economy. The objectives are: (1) Develop an optimal, cost effective, variable valve actuation (VVA) system for advanced low temperature diesel combustion processes. (2) Design and model alternative mechanical approaches and down-select for optimum design. (3) Build and demonstrate a mechanism capable of application on running engines.

  6. IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 40, NO. 2, MARCH/APRIL 2004 565 Modeling and Control of a Variable-Speed

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    -alone diesel and gasoline generators, and aerospace and naval power generation systems where a variable speed and Control of a Variable-Speed Constant-Frequency Synchronous Generator With Brushless Exciter Chunting Mi-frequency power generation system for renewable and distributed energy applications. The generation system

  7. HVDC-AC system interaction from AC harmonics. Volume 1. Harmonic impedance calculations. Final report

    SciTech Connect (OSTI)

    Breuer, G D; Chow, J H; Lindh, C B; Miller, N W; Numrich, F H; Price, W W; Turner, A E; Whitney, R R

    1982-09-01T23:59:59.000Z

    Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac filter design for HVDC systems and a survey of literature related to filter design have been performed. Two methods for calculating system harmonic impedances have been investigated. In the measurement method, an instrumentation system for measuring system voltage and current has been assembled. Different schemes of using the measurements to calculate system harmonic impedances have been studied. In the analytical method, a procedure to include various operating conditions has been proposed. Computer programs for both methods have been prepared, and the results of the measurement and analytical methods analyzed. A conclusion of the project is that the measurement and analytical methods both provided reasonable results. There are correlations between the measured and analytical results for most harmonics, although there are discrepancies between the assumptions used in the two methods. A sensitivity approach has been proposed to further correlate the results. From the results of the analysis, it is recommended that both methods should be tested further. For the measurement method, more testing should be done to cover different system operating conditions. In the analytical method, more detailed models for representing system components should be studied. In addition, alternative statistical and sensitivity approaches should be attempted.

  8. DC, AC and advanced EV propulsion systems

    SciTech Connect (OSTI)

    O'Neil, W.

    1983-08-01T23:59:59.000Z

    Battery development and liquid fuel availability and cost are still the pacing factors in wide scale electric vehicle introduction. Propulsion systems also require technical development, however, if electric vehicles are to be acceptable in the marketplace in competition against ICE vehicles. Eaton Corporation has undertaken a program designed to identify and investigate three broad types of propulsion systems in identical test vehicles on the same test track under conditions as similar as possible. Characteristics of dc, ac and advanced systems are compared to date, and projections of anticipated results and further work are provided. The compelling advantages of multiple mechanical ratios in EV propulsion systems are reviewed. An emerging, but less obvious, advantage is higher overall system efficiency.

  9. Application of the AC Commutator Machine in Wind Energy Conversion Systems

    E-Print Network [OSTI]

    El-Jamous, Sami Georges

    1981-01-01T23:59:59.000Z

    OF C~ Page ABSTRACT DEDICATION iV LIST OF TABLES LIST OF FIGURES A SURVEY OF THE LITJRATURE Constant Speed Constant Frequency Systems (CSCF) Variable Speed Constant Frequency Systems (VSCF) BASIC THEORY OF WIND TURBINES Classification...] 57 59 61 21. Power, P snd torque, T /rotational speed curves for P P different wind speeds [1] 63 22. Torque-speed curves of the turbine for different wind speeds V 23. Torque-speed curves with shunt ACCG 24. Connection of the shunt ACCG...

  10. 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.

  11. 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...

  12. AC transport in p-Ge/GeSi quantum well in high magnetic fields

    SciTech Connect (OSTI)

    Drichko, I. L.; Malysh, V. A.; Smirnov, I. Yu.; Golub, L. E.; Tarasenko, S. A. [A.F. Ioffe Physical Technical Institute of Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation); Suslov, A. V. [National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States); Mironov, O. A. [Warwick SEMINANO R and D Center, University of Warwick Science Park, Coventry CV4 7EZ (United Kingdom); Kummer, M.; Känel, H. von [Laboratorium für Festkörperphysik ETH Zürich, CH-8093 Zürich (Switzerland)

    2014-08-20T23:59:59.000Z

    The contactless surface acoustic wave technique is implemented to probe the high-frequency conductivity of a high-mobility p-Ge/GeSi quantum well structure in the regime of integer quantum Hall effect (IQHE) at temperatures 0.3–5.8 K and magnetic fields up to 18 T. It is shown that, in the IQHE regime at the minima of conductivity, holes are localized and ac conductivity is of hopping nature and can be described within the “two-site” model. The analysis of the temperature and magnetic-field-orientation dependence of the ac conductivity at odd filing factors enables us to determine the effective hole g-factor, |g{sub zz}|?4.5. It is shown that the in-plane component of the magnetic field leads to a decrease in the g-factor as well as increase in the cyclotron mass, which is explained by orbital effects in the complex valence band of germanium.

  13. Microwave and Radio Frequency Workshop

    Broader source: Energy.gov [DOE]

    At the Microwave and Radio Frequency Workshop (held in Long Beach, CA, on July 25, 2012), academic and industry experts discussed the existing and emerging electrotechnologies – such as microwave ...

  14. Contract Number: DE-AC05-76RL01830 Modification M705

    E-Print Network [OSTI]

    #12;#12;Contract Number: DE-AC05-76RL01830 Modification M705 #12;Contract Number: DE-AC05-76RL01830 Modification M705 #12;Contract Number: DE-AC05-76RL01830 Modification M705 #12;Contract Number: DE-AC05-76RL01830 Modification M705 #12;Contract Number: DE-AC05-76RL01830 Modification M705 #12;Contract Number: DE

  15. Frequency regulator for synchronous generators

    DOE Patents [OSTI]

    Karlicek, R.F.

    1982-08-10T23:59:59.000Z

    The present invention is directed to a novel frequency regulator which controls a generator output frequency for variations in both the input power to the generator and the power supplied to an uncontrolled external load. The present invention further includes over current and current balance protection devices which are relatively inexpensive to manufacture, which may be encapsulated to provide protection from the operating environment and which respond more quickly than previously known electromechanical devices. 11 figs.

  16. An ultra low-noise AC beam transformer and digital signal processing system for CERN's ELENA ring

    E-Print Network [OSTI]

    Angoletta, M E; Caspers, F; Federmann, S; Molendijk, J; Pedersen, F; Sanchez-Quesada, J

    2013-01-01T23:59:59.000Z

    CERN’s Extra Low ENergy Antiproton (ELENA) ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons coming from CERN’s Antiproton Decelerator (AD). Essential longitudinal diagnostics required for commissioning and operation include the intensity measurement for bunched and debunched beams and the measurement of p/p for debunched beams to assess the electron cooling performance. The beam phase information is also needed by the Low-Level RF (LLRF) system. The baseline system for providing the required beam parameters and signals is based upon two ultra-low-noise AC beam transformers and associated digital signal processing. The AC beam transformers cover different frequency regions and are an adaptation to the ELENA layout of those used in the AD. Two AC beam transformers will also be installed in the extraction lines to provide beam intensity measurements. The digital signal processing will be carried out with the leadingedge hardware family used for ELENA’s L...

  17. www.eprg.group.cam.ac.uk EPRGWORKINGPAPER

    E-Print Network [OSTI]

    Aickelin, Uwe

    are efficiency, sustainability and security of energy supplies (Euwww.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Conceptualizing Energy Security EPRG Working Paper 1123 Cambridge Working Paper in Economics 1151 Christian Winzer Energy security is one of the main

  18. A Distributed Generation Control Architecture for Islanded AC Microgrids

    E-Print Network [OSTI]

    Dominguez-Garcia, Alejandro

    1 A Distributed Generation Control Architecture for Islanded AC Microgrids Stanton T. Cady, Student architecture for generation control in islanded microgrids, and illustrate the performance Member, IEEE Abstract In this paper, we propose a distributed architecture for generation control

  19. acs news service: Topics by E-print Network

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

    www.mmu.ac.ukcareers PG ProfessionalVocational courses: Courses to allow you to enter certain professions Courses involve lectures for the first two terms then a research...

  20. www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY

    E-Print Network [OSTI]

    Aickelin, Uwe

    www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY Contracting for wind generation EPRG to the current Renewable Obligation Certificates, ROCs, where an on-shore wind generator receives one ROC

  1. acs presspac: Topics by E-print Network

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

    limits. The models are used to estimate the benefits of electricity locational marginal pricing (LMP) that arise from de Gispert, Adri 344 www.eprg.group.cam.ac.uk...

  2. ac microsized gliding: Topics by E-print Network

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

    limits. The models are used to estimate the benefits of electricity locational marginal pricing (LMP) that arise from de Gispert, Adri 417 www.eprg.group.cam.ac.uk...

  3. acs evidence based: Topics by E-print Network

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

    limits. The models are used to estimate the benefits of electricity locational marginal pricing (LMP) that arise from de Gispert, Adri 260 34CEN.ACS.ORG DECEMBER 23, 2013...

  4. ac surface photovoltage: Topics by E-print Network

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

    limits. The models are used to estimate the benefits of electricity locational marginal pricing (LMP) that arise from de Gispert, Adri 483 www.eprg.group.cam.ac.uk...

  5. ac electrokinetic micropumps: Topics by E-print Network

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

    limits. The models are used to estimate the benefits of electricity locational marginal pricing (LMP) that arise from de Gispert, Adri 477 www.eprg.group.cam.ac.uk...

  6. acs na periferia: Topics by E-print Network

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

    limits. The models are used to estimate the benefits of electricity locational marginal pricing (LMP) that arise from de Gispert, Adri 388 www.eprg.group.cam.ac.uk...

  7. acute cholecystitis ac: Topics by E-print Network

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

    limits. The models are used to estimate the benefits of electricity locational marginal pricing (LMP) that arise from de Gispert, Adri 384 www.eprg.group.cam.ac.uk...

  8. Cognitive Radio Network {swjang, sbahk}@netlab.snu.ac.kr

    E-Print Network [OSTI]

    Bahk, Saewoong

    2010 Cognitive Radio Network , , {swjang, sbahk}@netlab.snu.ac.kr Analysis of Average Opportunities in Cognitive Radio Networks Seowoo Jang, Saewoong Bahk INMC, EECS, Seoul National University Cognitive Radio Network . Primary user

  9. ac loss measurement: Topics by E-print Network

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

    tape, tem- perature dependence, total ac loss, transport loss. I. INTRODUCTION HIGH 6 Heat Loss Measurement Using Infrared Imaging Texas A&M University - TxSpace Summary: in...

  10. ac linear positioning: Topics by E-print Network

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

    USA kimik@yonsei.ac.kr Abstract- In this paper, one linear tapered slot antenna (LTSA), backed Tentzeris, Manos 187 The Square Root Law Requires a Linear Key Andrew D. Ker...

  11. November 2013 www.kent.ac.uk/library

    E-Print Network [OSTI]

    Banaji,. Murad

    November 2013 www.kent.ac.uk/library Information Services Templeman Library SCONUL Access scheme) to the Templeman Library. I am a registered member of the Sconul Access scheme and hold a valid card. If given ............................... ................................................................................................................ Home library

  12. acs morphological study: Topics by E-print Network

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

    (more) Yang, Emma Yunyi 2013-01-01 29 Study of supplementary controls for embedded HVDC links in a AC power system. Open Access Theses and Dissertations Summary: ??This...

  13. ac impedance study: Topics by E-print Network

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

    high chromaticity. White, S 2014-01-01 37 Study of supplementary controls for embedded HVDC links in a AC power system. Open Access Theses and Dissertations Summary: ??This...

  14. Microfluidics {sjauh, btzhang}@bi.snu.ac.kr

    E-Print Network [OSTI]

    Microfluidics {sjauh, btzhang}@bi.snu.ac.kr Solving Shortest Path Problems Using Microfluidics Sahng-Joon Auh and Byoung-Tak Zhang Biointelligence Lab, School of Computer Science and Engineering Seoul National University . microfluidics MEMS

  15. ac magnetic field: Topics by E-print Network

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

    contract No. DE-AC02-76CH00016. Abstract A common coil design concept for 2-in-1 superconduct- ing Gupta, Ramesh 126 Anisotropy of magnetic emulsions induced by magnetic and...

  16. ac magnetic fields: Topics by E-print Network

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

    contract No. DE-AC02-76CH00016. Abstract A common coil design concept for 2-in-1 superconduct- ing Gupta, Ramesh 126 Anisotropy of magnetic emulsions induced by magnetic and...

  17. www.arts.canterbury.ac.nz/internships Project Title

    E-Print Network [OSTI]

    Hickman, Mark

    , researching suppliers and material requirements. The intern will also do research about.arts.canterbury.ac.nz/internships Necessary Qualifications: Major/Minors(s): All majors in the B.A. especially those interested in media

  18. Stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Vadnais, Kenneth G. (Ojai, CA); Bashforth, Michael B. (Buellton, CA); Lewallen, Tricia S. (Ventura, CA); Nammath, Sharyn R. (Santa Barbara, CA)

    1994-01-01T23:59:59.000Z

    A stepped frequency ground penetrating radar system is described comprising an RF signal generating section capable of producing stepped frequency signals in spaced and equal increments of time and frequency over a preselected bandwidth which serves as a common RF signal source for both a transmit portion and a receive portion of the system. In the transmit portion of the system the signal is processed into in-phase and quadrature signals which are then amplified and then transmitted toward a target. The reflected signals from the target are then received by a receive antenna and mixed with a reference signal from the common RF signal source in a mixer whose output is then fed through a low pass filter. The DC output, after amplification and demodulation, is digitized and converted into a frequency domain signal by a Fast Fourier Transform. A plot of the frequency domain signals from all of the stepped frequencies broadcast toward and received from the target yields information concerning the range (distance) and cross section (size) of the target.

  19. RR Lyrae variables in M32 and the disk of M31

    E-Print Network [OSTI]

    Fiorentino, Giuliana; Trager, Scott C; Lauer, Tod R; Saha, Abhijit; Mighell, Kenneth J; Freedman, Wendy; Dressler, Alan; Grillmair, Carl; Tolstoy, Eline

    2009-01-01T23:59:59.000Z

    We observed two fields near M32 with the Advanced Camera for Surveys/High Resolution Channel (ACS/HRC) on board the Hubble Space Telescope (HST). The main field, F1, is 1.8 arcmin from the center of M32; the second field, F2, constrains the M31 background, and is 5.4 arcmin distant. Each field was observed for 16-orbits in each of the F435W (narrow B) and F555W (narrow V) filters. The duration of the observations allowed RR Lyrae stars and other short-period variables to be detected. A population of RR Lyrae stars determined to belong to M32 would prove the existence of an ancient population in that galaxy, a subject of some debate. We detected 17 RR Lyrae variables in F1 and 14 in F2. A 1-sigma upper limit of 6 RR Lyrae variables belonging to M32 is inferred from these two fields alone. Use of our two ACS/WFC parallel fields provides better constraints on the M31 background, however, and implies that $7_{-3}^{+4}$ (68 % confidence interval) RR Lyrae variables in F1 belong to M32. We have therefore found evid...

  20. Method and apparatus for generating radiation utilizing DC to AC conversion with a conductive front

    DOE Patents [OSTI]

    Dawson, J.M.; Mori, W.B.; Lai, C.H.; Katsouleas, T.C.

    1998-07-14T23:59:59.000Z

    Method and apparatus ar disclosed for generating radiation of high power, variable duration and broad tunability over several orders of magnitude from a laser-ionized gas-filled capacitor array. The method and apparatus convert a DC electric field pattern into a coherent electromagnetic wave train when a relativistic ionization front passes between the capacitor plates. The frequency and duration of the radiation is controlled by the gas pressure and capacitor spacing. 4 figs.

  1. Method and apparatus for generating radiation utilizing DC to AC conversion with a conductive front

    DOE Patents [OSTI]

    Dawson, John M. (Pacific Palisades, CA); Mori, Warren B. (Hermosa Beach, CA); Lai, Chih-Hsiang (So. Pasadena, CA); Katsouleas, Thomas C. (Malibu, CA)

    1998-01-01T23:59:59.000Z

    Method and apparatus for generating radiation of high power, variable duration and broad tunability over several orders of magnitude from a laser-ionized gas-filled capacitor array. The method and apparatus convert a DC electric field pattern into a coherent electromagnetic wave train when a relativistic ionization front passes between the capacitor plates. The frequency and duration of the radiation is controlled by the gas pressure and capacitor spacing.

  2. Adjustable Speed AC Motor Drives-Applications Problems

    E-Print Network [OSTI]

    Enjeti, P.

    Adjustable Speed AC Motor Drives Applications Problems by Dr. P. Enjeti Power Quality Laboratory Department ofElectrical Engineering Texas A&M University College Station, TX 77843 Tel: 409-845-7466 Fax: 409-845-6259 Email..., it generates side effects, some which have been recognized only recently. This paper presents a comprehensive coverage of application issues of PWM inverter controlled ac motor drives which include damage to motor insulation due to reflected voltages caused...

  3. Development of an AC Module System: Final Technical Report

    SciTech Connect (OSTI)

    Suparna Kadam; Miles Russell

    2012-06-15T23:59:59.000Z

    The GreenRay Inc. program focused on simplifying solar electricity and making it affordable and accessible to the mainstream population. This was accomplished by integrating a solar module, micro-inverter, mounting and monitoring into a reliable, 'plug and play' AC system for residential rooftops, offering the following advantages: (1) Reduced Cost: Reduction in installation labor with fewer components, faster mounting, faster wiring. (2) Maximized Energy Production: Each AC Module operates at its maximum, reducing overall losses from shading, mismatch, or module downtime. (3) Increased Safety. Electrical and fire safety experts agree that AC Modules have significant benefits, with no energized wiring or live connections during installation, maintenance or emergency conditions. (4) Simplified PV for a Broader Group of Installers. Dramatic simplification of design and installation of a solar power system, enabling faster and more efficient delivery of the product into the market through well-established, mainstream channels. This makes solar more accessible to the public. (5) Broadened the Rooftop Market: AC Modules enable solar for many homes that have shading, split roofs, or obstructions. In addition, due to the smaller building block size of 200W vs. 1000W, homeowners with budget limitations can start small and add to their systems over time. Through this DOE program GreenRay developed the all-in-one AC Module system with an integrated PV Module and microinverter, custom residential mounting and performance monitoring. Development efforts took the product from its initial concept, through prototypes, to a commercial product sold and deployed in the residential market. This pilot deployment has demonstrated the technical effectiveness of the AC Module system in meeting the needs and solving the problems of the residential market. While more expensive than the traditional central inverter systems at the pilot scale, the economics of AC Modules become more and more favorable as the product matures and is made in high volumes. GreenRay's early customers have been highly enthusiastic about the AC Module system benefits.

  4. http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html

    E-Print Network [OSTI]

    2011 P6 http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html web #12;http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html () ( #12;http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html X MeV X Astro-H 2013 TeV10m) #12;http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html 2010 ASTRO-H CCD X (2) () (2) (2

  5. Radial Velocity Variability of Field Brown Dwarfs

    E-Print Network [OSTI]

    Prato, L; Rice, E L; McLean, I S; Kirkpatrick, J D; Burgasser, A J; Kim, S S

    2015-01-01T23:59:59.000Z

    We present paper six of the NIRSPEC Brown Dwarf Spectroscopic Survey, an analysis of multi-epoch, high-resolution (R~20,000) spectra of 25 field dwarf systems (3 late-type M dwarfs, 16 L dwarfs, and 6 T dwarfs) taken with the NIRSPEC infrared spectrograph at the W. M. Keck Observatory. With a radial velocity precision of ~2 km/s, we are sensitive to brown dwarf companions in orbits with periods of a few years or less given a mass ratio of 0.5 or greater. We do not detect any spectroscopic binary brown dwarfs in the sample. Given our target properties, and the frequency and cadence of observations, we use a Monte Carlo simulation to determine the detection probability of our sample. Even with a null detection result, our 1 sigma upper limit for very low mass binary frequency is 18%. Our targets included 7 known, wide brown dwarf binary systems. No significant radial velocity variability was measured in our multi-epoch observations of these systems, even for those pairs for which our data spanned a significant ...

  6. WECC Variable Generation Planning Reference Book: Appendices

    SciTech Connect (OSTI)

    Makarov, Yuri V.; Du, Pengwei; Etingov, Pavel V.; Ma, Jian; Vyakaranam, Bharat

    2013-05-13T23:59:59.000Z

    The document titled “WECC Variable Generation Planning Reference Book”. This book is divided into two volumes; one is the main document (volume 1)and the other is appendices (volume 2). The main document is a collection of the best practices and the information regarding the application and impact of variables generation on power system planning. This volume (appendices) has additional information on the following topics: Probabilistic load flow problems. 2. Additional useful indices. 3. high-impact low-frequency (HILF) events. 4. Examples of wide-area nomograms. 5. Transmission line ratings, types of dynamic rating methods. 6. Relative costs per MW-km of different electric power transmission technologies. 7. Ultra-high voltage (UHV) transmission. 8.High voltage direct current (VSC-HVDC). 9. HVDC. 10. Rewiring of existing transmission lines. 11. High-temperature low sag (HTLS) conductors. 12. The direct method and energy functions for transient stability analysis in power systems. 13.Blackouts caused by voltage instability. 14. Algorithm for parameter continuation predictor-corrector methods. 15. Approximation techniques available for security regions. 16. Impacts of wind power on power system small signals stability. 17. FIDVR. 18. FACTS. 19. European planning standard and practices. 20. International experience in wind and solar energy sources. 21. Western Renewable Energy Zones (WREZ). 22. various energy storage technologies. 23. demand response. 24. BA consolidation and cooperation options. 25. generator power management requirements and 26. European planning guidelines.

  7. System and method for determining stator winding resistance in an AC motor using motor drives

    DOE Patents [OSTI]

    Lu, Bin; Habetler, Thomas G; Zhang, Pinjia

    2013-02-26T23:59:59.000Z

    A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

  8. High frequency and high wavenumber solar oscillations

    E-Print Network [OSTI]

    H. M. Antia; Sarbani Basu

    1999-02-10T23:59:59.000Z

    We determine the frequencies of solar oscillations covering a wide range of degree (100< l <4000) and frequency (1.5 <\

  9. Sum Frequency Generation for Surface Vibrational Spectroscopy...

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

    Sum Frequency Generation for Surface Vibrational Spectroscopy Sum Frequency Generation for Surface Vibrational Spectroscopy This customized SFG-VS spectrometer incorporates unique...

  10. Application of Resonant Frequency Eddy Current Technique on a Shot-Peened Nickel-Based Engine-Grade Material

    SciTech Connect (OSTI)

    Ko, Ray T.; Sathish, Shamachary; Boehnlein, Thomas R. [Structural Integrity Division, University of Dayton Research Institute, 300 College Park Drive, Dayton, Ohio 45469-0120 (United States); Blodgett, Mark P. [Metals, Ceramics, and NDE Division, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States)

    2007-03-21T23:59:59.000Z

    The shot peening conditions of a nickel-based engine-grade material were evaluated using a novel eddy current measurement technique. With this technique, the shift of a resonant frequency was found to be dependent on variables which also affect conventional eddy current testing. The cable effect is another important variable, which is often neglected in a routine eddy current testing, is also discussed. Experimental results showed that at high frequencies, the shot peening conditions were easily distinguishable using this frequency shift technique.

  11. Preferred frequencies for three unconsolidated earth materials Laura E. Gilcrista

    E-Print Network [OSTI]

    Sen, Surajit

    Generator powered by a 12 V battery via dc to ac power inverter. The function gen- erator is connected

  12. 882 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 47, NO. 6, JUNE 1999 State-Variable-Based Transient Analysis

    E-Print Network [OSTI]

    Rodwell, Mark J. W.

    , circuit transient analysis, convolution, nonlinear circuits, solitons, state variables. I. INTRODUCTION TRANSIENT analysis of distributed microwave circuits is complicated by the inability of frequency, the linear part of a microwave circuit is described in the frequency domain by network parameters, especially

  13. DE-AC05-00OR22725 Section B--Page 1 of 7 DE-AC05-00OR22725

    E-Print Network [OSTI]

    .......................................................................... 5 #12;DE-AC05-00OR22725 Section B--Page 2 of 7 DE-AC05-000R22725 Modification No. 760 Section B Blank Page #12;DE-AC05-00OR22725 Section B--Page 3 of 7 DE-AC05-000R22725 Modification No. 760 Section B of 7 DE-AC05-000R22725 Modification No. 760 Section B 4) $267,518 for the project entitled "4500 Area

  14. Abstract--Heart rate variability (HRV) is frequently used to measure autonomic nervous system (ANS) activity. However,

    E-Print Network [OSTI]

    1 of 4 Abstract--Heart rate variability (HRV) is frequently used to measure autonomic nervous frequency (HF) ratio with little change in mean heart rate. Results suggest that nicotine affects both components may yield erroneous results. Keywords--Autonomic regulation, heart rate variability, Lomb

  15. Monthly Variable-based Degree Day Template: A Spreadsheet Procedure Calculating a 3 Parameter Change-point Model for Residential or Commercial Buildings

    E-Print Network [OSTI]

    Landman, D. S.; Haberl, J. S.

    1996-01-01T23:59:59.000Z

    Systems, Inc. for the U. S. Department of Energy under Contract No. DE-AC05-84OR41200 ) Revised August 1996 p. 2 Abstract This report presents a spreadsheet procedure for calculating a variable-based degree day or three parameter change-point models using... College Station, TX p. 19 Acknowledgments Funding for this project was provided by the USDOE through Oak Ridge National Laboratory (Contract No. DE-AC05-840R41200) Significant input and project guidance was provided by Mr. Mike MacDonald, ORNL Project...

  16. Frequency agile optical parametric oscillator

    DOE Patents [OSTI]

    Velsko, Stephan P. (Livermore, CA)

    1998-01-01T23:59:59.000Z

    The frequency agile OPO device converts a fixed wavelength pump laser beam to arbitrary wavelengths within a specified range with pulse to pulse agility, at a rate limited only by the repetition rate of the pump laser. Uses of this invention include Laser radar, LIDAR, active remote sensing of effluents/pollutants, environmental monitoring, antisensor lasers, and spectroscopy.

  17. Frequency agile optical parametric oscillator

    DOE Patents [OSTI]

    Velsko, S.P.

    1998-11-24T23:59:59.000Z

    The frequency agile OPO device converts a fixed wavelength pump laser beam to arbitrary wavelengths within a specified range with pulse to pulse agility, at a rate limited only by the repetition rate of the pump laser. Uses of this invention include Laser radar, LIDAR, active remote sensing of effluents/pollutants, environmental monitoring, antisensor lasers, and spectroscopy. 14 figs.

  18. AC Loss Measurements on a 2G YBCO Coil

    SciTech Connect (OSTI)

    Rey, Christopher M [ORNL] [ORNL; Duckworth, Robert C [ORNL] [ORNL; Schwenterly, S W [ORNL] [ORNL

    2011-01-01T23:59:59.000Z

    The Oak Ridge National Laboratory (ORNL) is collaborating with Waukesha Electric Systems (WES) to continue development of HTS power transformers. For compatibility with the existing power grid, a commercially viable HTS transformer will have to operate at high voltages in the range of 138 kV and above, and will have to withstand 550-kV impulse voltages as well. Second-generation (2G) YBCO coated conductors will be required for an economically-competitive design. In order to adequately size the refrigeration system for these transformers, the ac loss of these HTS coils must be characterized. Electrical AC loss measurements were conducted on a prototype high voltage (HV) coil with co-wound stainless steel at 60 Hz in a liquid nitrogen bath using a lock-in amplifier technique. The prototype HV coil consisted of 26 continuous (without splice) single pancake coils concentrically centered on a stainless steel former. For ac loss measurement purposes, voltage tap pairs were soldered across each set of two single pancake coils so that a total of 13 separate voltage measurements could be made across the entire length of the coil. AC loss measurements were taken as a function of ac excitation current. Results show that the loss is primarily concentrated at the ends of the coil where the operating fraction of critical current is the highest and show a distinct difference in current scaling of the losses between low current and high current regimes.

  19. Quantum information with modular variables

    E-Print Network [OSTI]

    A. Ketterer; S. P. Walborn; A. Keller; T. Coudreau; P. Milman

    2014-06-24T23:59:59.000Z

    We introduce a novel strategy, based on the use of modular variables, to encode and deterministically process quantum information using states described by continuous variables. Our formalism leads to a general recipe to adapt existing quantum information protocols, originally formulated for finite dimensional quantum systems, to infinite dimensional systems described by continuous variables. This is achieved by using non unitary and non-gaussian operators, obtained from the superposition of gaussian gates, together with adaptative manipulations in qubit systems defined in infinite dimensional Hilbert spaces. We describe in details the realization of single and two qubit gates and briefly discuss their implementation in a quantum optical set-up.

  20. Wind/PV Generation for Frequency Regulation and Oscillation Damping in the Eastern Interconnection

    SciTech Connect (OSTI)

    Liu, Yong [The University of Tennessee, Knoxville; Gracia, Jose R [ORNL; Hadley, Stanton W [ORNL; Liu, Yilu [ORNL

    2013-12-01T23:59:59.000Z

    This report presents the control of renewable energy sources, including the variable-speed wind generators and solar photovoltaic (PV) generators, for frequency regulation and inter-area oscillation damping in the U.S. Eastern Interconnection (EI). In this report, based on the user-defined wind/PV generator electrical control model and the 16,000-bus Eastern Interconnection dynamic model, the additional controllers for frequency regulation and inter-area oscillation damping are developed and incorporated and the potential contributions of renewable energy sources to the EI system frequency regulation and inter-area oscillation damping are evaluated.

  1. Anyonic statistics with continuous variables

    E-Print Network [OSTI]

    Jing Zhang; Changde Xie; Kunchi Peng; Peter van Loock

    2008-10-30T23:59:59.000Z

    We describe a continuous-variable scheme for simulating the Kitaev lattice model and for detecting statistics of abelian anyons. The corresponding quantum optical implementation is solely based upon Gaussian resource states and Gaussian operations, hence allowing for a highly efficient creation, manipulation, and detection of anyons. This approach extends our understanding of the control and application of anyons and it leads to the possibility for experimental proof-of-principle demonstrations of anyonic statistics using continuous-variable systems.

  2. Superconducting shielded core reactor with reduced AC losses

    DOE Patents [OSTI]

    Cha, Yung S.; Hull, John R.

    2006-04-04T23:59:59.000Z

    A superconducting shielded core reactor (SSCR) operates as a passive device for limiting excessive AC current in a circuit operating at a high power level under a fault condition such as shorting. The SSCR includes a ferromagnetic core which may be either closed or open (with an air gap) and extends into and through a superconducting tube or superconducting rings arranged in a stacked array. First and second series connected copper coils each disposed about a portion of the iron core are connected to the circuit to be protected and are respectively wound inside and outside of the superconducting tube or rings. A large impedance is inserted into the circuit by the core when the shielding capability of the superconducting arrangement is exceeded by the applied magnetic field generated by the two coils under a fault condition to limit the AC current in the circuit. The proposed SSCR also affords reduced AC loss compared to conventional SSCRs under continuous normal operation.

  3. Variable metric conjugate gradient methods

    SciTech Connect (OSTI)

    Barth, T.; Manteuffel, T.

    1994-07-01T23:59:59.000Z

    1.1 Motivation. In this paper we present a framework that includes many well known iterative methods for the solution of nonsymmetric linear systems of equations, Ax = b. Section 2 begins with a brief review of the conjugate gradient method. Next, we describe a broader class of methods, known as projection methods, to which the conjugate gradient (CG) method and most conjugate gradient-like methods belong. The concept of a method having either a fixed or a variable metric is introduced. Methods that have a metric are referred to as either fixed or variable metric methods. Some relationships between projection methods and fixed (variable) metric methods are discussed. The main emphasis of the remainder of this paper is on variable metric methods. In Section 3 we show how the biconjugate gradient (BCG), and the quasi-minimal residual (QMR) methods fit into this framework as variable metric methods. By modifying the underlying Lanczos biorthogonalization process used in the implementation of BCG and QMR, we obtain other variable metric methods. These, we refer to as generalizations of BCG and QMR.

  4. Low-frequency, self-sustained oscillations in inductively coupled plasmas used for optical pumping

    SciTech Connect (OSTI)

    Coffer, J.; Encalada, N.; Huang, M.; Camparo, J. [Physical Sciences Laboratories, The Aerospace Corporation 2310, E. El Segundo Blvd., El Segundo, California 90245 (United States)

    2014-10-28T23:59:59.000Z

    We have investigated very low frequency, on the order of one hertz, self-pulsing in alkali-metal inductively-coupled plasmas (i.e., rf-discharge lamps). This self-pulsing has the potential to significantly vary signal-to-noise ratios and (via the ac-Stark shift) resonant frequencies in optically pumped atomic clocks and magnetometers (e.g., the atomic clocks now flying on GPS and Galileo global navigation system satellites). The phenomenon arises from a nonlinear interaction between the atomic physics of radiation trapping and the plasma's electrical nature. To explain the effect, we have developed an evaporation/condensation theory (EC theory) of the self-pulsing phenomenon.

  5. List of Participants Brian Baptie British Geological Survey bbap@bgs.ac.uk

    E-Print Network [OSTI]

    .ac.uk Nicola D'Agostino Istituto Nazionale Geofisica Vulcanologia dagostin@ingv.it Serena Davies 360 Production@bgs.ac.uk Guilio Selvaggi Istituto Nazionale Geofisica Vulcanologia selvaggi@ingv.it Alistair Sloan Earth Sciences

  6. DE-AC02-76SF00515 Apr2007/Rev 1

    E-Print Network [OSTI]

    Wechsler, Risa H.

    DE-AC02-76SF00515 Appendix B Apr2007/Rev 1 FY 2007 Contractor Performance Evaluation and Measurement Plan for Management and Operations ofthe Stanford Linear Accelerator Center J-B-i #12;DE-AC02

  7. Quantum memory of a squeezed vacuum for arbitrary frequency sidebands

    SciTech Connect (OSTI)

    Arikawa, Manabu; Honda, Kazuhito; Akamatsu, Daisuke; Nagatsuka, Satoshi; Akiba, Keiichirou [Department of Physics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8550 (Japan); Furusawa, Akira [Department of Applied Physics, School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Kozuma, Mikio [Department of Physics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8550 (Japan); CREST, Japan Science and Technology Agency, 1-9-9 Yaesu, Chuo-ku, Tokyo 103-0028 (Japan)

    2010-02-15T23:59:59.000Z

    We have developed a quantum memory that is completely compatible with current quantum information processing for continuous variables of light, where arbitrary frequency sidebands of a squeezed vacuum can be stored and retrieved using bichromatic electromagnetic induced transparency. The 2 MHz sidebands of squeezed vacuum pulses with temporal widths of 470 ns and a squeezing level of -1.78{+-}0.02 dB were stored for 3 {mu}s in laser-cooled {sup 87}Rb atoms. Squeezing of -0.44{+-}0.02 dB, which is the highest squeezing reported for a retrieved pulse, was achieved.

  8. Distributed Gradient Methods with Variable Number of Working Nodes

    E-Print Network [OSTI]

    2015-04-15T23:59:59.000Z

    Serbia. Authors' e-mails: [djakovet,dbajovic]@uns.ac.rs, natasak@uns.ac.rs, ... translate into energy saving of the sensor motes' batteries and the increase of the

  9. Binary Frequencies in Globular Clusters

    E-Print Network [OSTI]

    Ji, Jun

    2015-01-01T23:59:59.000Z

    Binary stars are predicted to have an important role in the evolution of globular clusters, so we obtained binary fractions for 35 globular clusters that were imaged in the F606W and F814W with the ACS on the Hubble Space Telescope. When compared to the values of prior efforts (Sollima et al. 2007; Milone et al. 2012), we find significant discrepancies, despite each group correcting for contamination effects and having performed the appropriate reliability tests. The most reliable binary fractions are obtained when restricting the binary fraction to q > 0.5. Our analysis indicates that the range of the binary fractions is nearly an order of magnitude for the lowest dynamical ages, suggesting that there is a broad distribution in the binary fraction at globular cluster formation. Dynamical effects also appears to decrease the core binary fractions by a factor of two over a Hubble time, but this is a weak relationship. We confirm a correlation from previous work that the binary fraction within the core radius d...

  10. A 3-phase AC to AC matrix converter using the Venturini method 

    E-Print Network [OSTI]

    Dabbousi, Rami M. Osama

    2002-01-01T23:59:59.000Z

    ]. 2. 1 Mathematical Description The input voltages are: V, -& ?? VI costs;t 21t V. =V cos(ot. t- ? ) i2 I i V. =V cos(to t+ ? ) 2tt i3 I where, oh is the input frequency The converter output current is sinusoidal: I t ? Io cos(toot+ ttto) 2...' I =I cos(to t ? +0 ) 02 0 o 3 2tt I 3 Io cos(toot + + t ) 0 0 where, to, is the output frequency 11 Consequently, the matrix equation representation for both the voltage and current is as follows: V, (t) =M(t)V, . (t) I, . (1) = M(t)'I. (1...

  11. Twitter @RoyalHolloway royalholloway.ac.ukfacebook.com Search: Royal Holloway, University of London

    E-Print Network [OSTI]

    Sheldon, Nathan D.

    connect@rhul.ac.uk Tuesday11 Royal Holloway Balkan Ensemble An energetic performance of Balkan music

  12. Law, Justice and Regulation at UEA law-justice-regulation@uea.ac.uk

    E-Print Network [OSTI]

    Everest, Graham R

    .dewing@uea.ac.uk Ivan Diaz-Rainey (NBS) Regulation of energy and environmental markets http://www.uea.ac.uk/nbs/people/People/Academic/Ivan+Diaz- Rainey i.diaz-rainey@uea.ac.uk Catherine Wad- dams (NBS/CCP) Economic regulation, competition, energy1 Network on Law, Justice and Regulation at UEA law-justice-regulation@uea.ac.uk 21 October 2010

  13. Boys and Girls, Be Ambitious! http://www.math.sci.hokudai.ac.jp/message/message-graduates/

    E-Print Network [OSTI]

    Nakamura, Iku

    ://www.math.sci.hokudai.ac.jp/ #12;AIKAWA, Hiroaki WebPage http://www.math.sci.hokudai.ac.jp/ aik/index-j.html Fatou Martin Harnack AKITA, Toshiyuki WebPage http://www.math.sci.hokudai.ac.jp/ akita/ Eilenberg-MacLane Coxeter #12;ASAKURA, Masanori ARAI, Asao ABE, Noriyuki WebPage http://www.math.sci.hokudai.ac.jp/ abenori/ #12;ISHIKAWA, Goo Web

  14. Variable optical attenuator with a polymer-stabilized dual-frequency liquid crystal

    E-Print Network [OSTI]

    Wu, Shin-Tson

    February 2005. 0003-6935/05/204394-04$15.00/0 © 2005 Optical Society of America 4394 APPLIED OPTICS Vol. 44,

  15. Low-Frequency Variability in the Midlatitude Baroclinic Atmosphere Induced by an Oceanic Thermal Front

    E-Print Network [OSTI]

    Ghil, Michael

    oscillatory modes dominate. As the two layers become nearly equal, antisymmetric oscillatory modes become of the atmospheric marine boundary layer (AMBL) to oceanic fronts has been studied in observations, as well's dynamics depends on the layer-depth ratio. When the model is nearly equivalent-barotropic, symmetric

  16. Computer-controlled, variable-frequency power supply for driving multipole ion guides

    E-Print Network [OSTI]

    Zare, Richard N.

    in a parallel geometry within an insulating spacer. rf waveforms, which are 180° out of phase with respect parameters, including ge- ometries, pressures, aperture dimensions, voltages applied to electrostatic

  17. PV Arc Fault Detector Challenges Due to Module Frequency Response Variability

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeedingBiomassPPPO Website Directory PPPOLarson.Cheryl A -Chapter

  18. Atmospheric circulation and cyclone frequency variations linked to the primary modes of Greenland snow accumulation

    E-Print Network [OSTI]

    Howat, Ian M.

    Atmospheric circulation and cyclone frequency variations linked to the primary modes of Greenland from 34 Greenland firn cores, extending from 1982 to 1996, are used to identify spatial accumulation component, representing west-central Greenland accumulation, is correlated to NAO variability, having

  19. A Comparative Study of Time-Frequency Representations for Fault Detection in Wind Turbine

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A Comparative Study of Time-Frequency Representations for Fault Detection in Wind Turbine El of wind energy, minimization and prediction of maintenance operations in wind turbine is of key importance. In variable speed turbine generator, advanced signal processing tools are required to detect and diagnose

  20. Quasi-Periodic Variability in NGC 5408 X-1

    E-Print Network [OSTI]

    Tod E. Strohmayer; Richard F. Mushotzky; Lisa Winter; Roberto Soria; Phil Uttley; Mark Cropper

    2007-01-12T23:59:59.000Z

    We report the discovery with XMM-Newton of quasiperiodic variability in the 0.2 - 10 keV X-ray flux from the ultraluminous X-ray source NGC 5408 X-1. The average power spectrum of all EPIC-pn data reveals a strong 20 mHz QPO with an average amplitude (rms) of 9%, and a coherence of Q~6. In a 33 ksec time interval when the 20 mHz QPO is strongest we also find evidence for a 2nd QPO peak at 15 mHz. This is the first indication for a close pair of QPOs in a ULX source. Interestingly, the frequency ratio of this QPO pair is inconsistent with 3:2 at the 3sigma level, but is consistent with a 4:3 ratio. A powerlaw noise component with slope near 1.5 is also present below 0.1 Hz with evidence for a break to a flatter slope at about 3 mHz. The source shows substantial broadband variability, with a total amplitude (rms) of about 30% in the 0.1 - 100 mHz frequency band, and there is strong energy dependence to the variability. We discuss the implications of these findings in the context of models for ULXs, and their implications for the object's mass.

  1. AC Losses in the MICE Channel Magnets -- Is This a Curse or aBlessing?

    SciTech Connect (OSTI)

    Green, M.A.; Wu, H.; Wang, L.; Kai, L.L.; Jia, L.X.; Yang, S.Q.

    2008-01-31T23:59:59.000Z

    This report discusses the AC losses in the MICE channelmagnets during magnet charging and discharging. This report talks aboutthe three types of AC losses in the MICE magnets; the hysteretic AC lossin the superconductor, the coupling AC loss in the superconductor and theeddy current AC loss in the magnet mandrel and support structure. AClosses increase the heat load at 4 K. The added heat load increases thetemperature of the second stage of the cooler. In addition, AC losscontributes to the temperature rise between the second stage cold headand the high field point of the magnet, which is usually close to themagnet hot spot. These are the curses of AC loss in the MICE magnet thatcan limit the rate at which the magnet can be charge or discharged. Ifone is willing to allow some of the helium that is around the magnet toboil away during a magnet charge or discharge, AC losses can become ablessing. The boil off helium from the AC losses can be used to cool theupper end of the HTS leads and the surrounding shield. The AC losses arepresented for all three types of MICE magnets. The AC loss temperaturedrops within the coupling magnet are presented as an example of how boththe curse and blessing of the AC losses can be combined.

  2. A scanning AC calorimetry technique for the analysis of nano-scale quantities of materials

    E-Print Network [OSTI]

    A scanning AC calorimetry technique for the analysis of nano-scale quantities of materials Kechao OF SCIENTIFIC INSTRUMENTS 83, 114901 (2012) A scanning AC calorimetry technique for the analysis of nano 2012) We present a scanning AC nanocalorimetry method that enables calorimetry measurements at heating

  3. Managing Variability throughout the Software Development Lifecycle

    E-Print Network [OSTI]

    Managing Variability throughout the Software Development Lifecycle Neil Loughran and Awais Rashid levels of the software development lifecycle, especially when new requirements arise. We believe of the software development lifecycle. Moreover, the effects of variability and, in particular, new variabilities

  4. Multi-frequency communication system and method

    DOE Patents [OSTI]

    Carrender, Curtis Lee; Gilbert, Ronald W.

    2004-06-01T23:59:59.000Z

    A multi-frequency RFID remote communication system is provided that includes a plurality of RFID tags configured to receive a first signal and to return a second signal, the second signal having a first frequency component and a second frequency component, the second frequency component including data unique to each remote RFID tag. The system further includes a reader configured to transmit an interrogation signal and to receive remote signals from the tags. A first signal processor, preferably a mixer, removes an intermediate frequency component from the received signal, and a second processor, preferably a second mixer, analyzes the IF frequency component to output data that is unique to each remote tag.

  5. University Policy No.: AC1110 Classification: Academic and Students

    E-Print Network [OSTI]

    Victoria, University of

    other than the university community. DEFINITIONS 2.00 EDUCATIONAL SERVICE CONTRACT means a contract://web.uvic.ca/univsec/pol_pro/pol1000/1002SA.html) 8.00 Approval of an Educational Service Contract will be granted by the Dean andUniversity Policy No.: AC1110 Classification: Academic and Students EDUCATIONAL SERVICE

  6. POLICY ON CALENDAR SUBMISSIONS University Policy No: AC1120

    E-Print Network [OSTI]

    Victoria, University of

    1 POLICY ON CALENDAR SUBMISSIONS University Policy No: AC1120 Classification: Academic and Students relevant university policies and procedures, academic policies and regulations, university fees, courses and programs of study. The purpose of this policy is to outline requirements for publishing the University

  7. University Policy No.: AC1130 Classification: Academic and Students

    E-Print Network [OSTI]

    Victoria, University of

    University Policy No.: AC1130 Classification: Academic and Students Approving Authority: Board Last Editorial Change: Mandated Review: 2018 PURPOSE 1.00 The purpose of this policy is to provide guidance on the establishment and governance of student awards by the university. POLICY 2.00 Student

  8. www.eprg.group.cam.ac.uk EPRGWORKINGPAPER

    E-Print Network [OSTI]

    Aickelin, Uwe

    parties in the nuclear supply chain whether they are providing decommissioning services, project, or the Parent Body Organisation responsible for decommissioning one the UK legacy nuclear installationswww.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Third Party Nuclear Liability: The Case

  9. www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY

    E-Print Network [OSTI]

    Aickelin, Uwe

    Body Organisation responsible for decommissioning one the UK legacy nuclear installationswww.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY Third Party Nuclear Liability 1207 Anthony Thomas and Raphael J. Heffron With a return to nuclear new build expected in the UK

  10. www.tyndall.ac.uk The Tyndall Centre is

    E-Print Network [OSTI]

    Watson, Andrew

    to bring benefits for greenhouse gas reduction and social and economic development. One of the most by the market-structure behind these projects." The research has developed criteria for evaluating CDM forestry PhD from the Mexico study. Further information: k.brown@uea.ac.uk Please see Tyndall Technical Report

  11. www.eprg.group.cam.ac.uk EPRGWORKINGPAPER

    E-Print Network [OSTI]

    Aickelin, Uwe

    of 107 Strategic Eurasian Natural Gas Model for Energy Security and Policy Analysis1 Chi-Kong Chyongwww.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Strategic Eurasian Natural Gas Model for Energy-Kong Chyong and Benjamin F. Hobbs The mathematical formulation of a large-scale equilibrium natural gas

  12. www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY

    E-Print Network [OSTI]

    Aickelin, Uwe

    . Although large-scale natural gas models have been developed and used for energy security and policywww.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY Strategic Eurasian Natural Gas Model-scale equilibrium natural gas simulation model that covers gas markets of the EU and the Former Soviet Union

  13. www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY

    E-Print Network [OSTI]

    Aickelin, Uwe

    in concern about the security of natural gas supply to Europe, particularly supplies from Russia. A numberwww.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY Gas Supply Security in the Baltic, determining its level of security is a virtually impossible. The specific gas supply set up, the structure

  14. www.eprg.group.cam.ac.uk EPRGWORKINGPAPER

    E-Print Network [OSTI]

    Aickelin, Uwe

    in place designed to mitigate the effects of a disruption. Keywords Natural Gas, security of supply, Baltic not entirely, by the rise in concern about the security of natural gas supply to Europe, particularly supplieswww.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Gas Supply Security in the Baltic States

  15. ACS DIVISION OF POLYMERIC MATERIALS: SCIENCE AND ENGINEERING

    E-Print Network [OSTI]

    Gilchrist, James F.

    , interpenetrating polymer networks, IPNs. Other topics included the mechanical and morphological aspects of polymers textbook, "Introduction to Physical Polymer Science," with Wiley, 2004. While in retirement, he remains for Polymer Science and Engineering, and served as Education Chairman. His efforts at ACS have included

  16. SCHOOL OF ENGINEERING www.abdn.ac.uk/engineering

    E-Print Network [OSTI]

    Levi, Ran

    , in the planning and commissioning of equipment, and in site and plant supervision. Engineers require a wide rangeSCHOOL OF ENGINEERING www.abdn.ac.uk/engineering POSTGRADUATE GUIDE #12;MSc Renewable Energy MSc Safety Engineering for Oil & Gas MSc Subsea Engineering MSc Oil & Gas Engineering MSc Project Management

  17. www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY

    E-Print Network [OSTI]

    de Gispert, Adrià

    as uncertainties are resolved reduces significantly its expected Levelised Cost Of generating Electricity (LCOE deterministic economic model to identify its LCOE without considering uncertainty. In the second step #12;www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY we identified sources of uncertainty in the design that would affect its LCOE

  18. Introduc)on of lab ac)vi)es

    E-Print Network [OSTI]

    Chen, Po

    ·Overview of lab ac)vi)es #12;·En-Jui (En-Ray) Lee · h@p://www.gg.uwyo.edu/ggstudent/elee8 of Water · The characteris)cs of tsunamis & the early warning systems. #12 · Hydraulic gradient and its calcula)on · How to determina)on of groundwater flow

  19. 1go.warwick.ac.uk/engineering ENGINEERING

    E-Print Network [OSTI]

    Davies, Christopher

    1go.warwick.ac.uk/engineering 2012-13 ENGINEERING UNDERGRADUATE BROCHURE #12;2 Engineering Prospectus 2012-13 "BECAUSE ENGINEERING IS INEXTRICABLY TIED TO PEOPLE, IT CANNOT BE JUST AN APPLIED PHYSICAL SCIENCE; IT IS ALSO AN APPLIED SOCIAL SCIENCE. ... (THE ENGINEER'S)... RAISON D'Ã?TRE IS TO SERVE

  20. www.eprg.group.cam.ac.uk EPRGWORKINGPAPER

    E-Print Network [OSTI]

    Aickelin, Uwe

    wind power, long-term contracts, balancing costs JEL Classification Q42, L14, L94 Contact dmgn. The estimated extra trading and balancing costs of a CfD for on-shore wind might be £70 million/yr by 2020www.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Contracting for wind generation EPRG Working

  1. www.eprg.group.cam.ac.uk EPRGWORKINGPAPER

    E-Print Network [OSTI]

    Aickelin, Uwe

    www.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Nuclear Energy in the Enlarged European Union of nuclear energy and notes that it has shifted significantly as the European Union has grown from 15 member states to 27. The proportion of member states with nuclear energy experience has increased markedly. Also

  2. www.eprg.group.cam.ac.uk EPRGWORKINGPAPER

    E-Print Network [OSTI]

    de Gispert, Adrià

    . The models are used to estimate the benefits of electricity locational marginal pricing (LMP) that arise fromwww.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Locational-based Coupling of Electricity Markets the effects of varying system characteristics on the magnitude of the locational-based unit commitment

  3. www.weizmann.ac.il/library Introduction 3

    E-Print Network [OSTI]

    to the Library's printed and digital collections, including books, journals, theses, serials, and online lectures Weizmann Institute of Science Libraries 5 Digital Access · Arranging access to newly purchased electronic#12;www.weizmann.ac.il/library 2 Contents Introduction 3 The Library's Website 3 The Library

  4. www.eprg.group.cam.ac.uk EPRGWORKINGPAPER

    E-Print Network [OSTI]

    Aickelin, Uwe

    This paper summarises and reviews scholarly and political comment that draws parallels between the current: the nature of the political discourse; the relationship between an ethics-driven societal shift and economic Change, Slavery, Political Rhetoric JEL Classification B15 Contact wjn21@cam.ac.uk Publication August

  5. www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY

    E-Print Network [OSTI]

    Aickelin, Uwe

    www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY Reforming Small Power Systems under Rabindra Nepal and Tooraj Jamasb The pioneering electricity sector reforms in developing Latin American of `successful and comprehensive electricity reforms' in many less-developed countries like Nepal. Nepal's power

  6. www.eprg.group.cam.ac.uk EPRGWORKINGPAPER

    E-Print Network [OSTI]

    Aickelin, Uwe

    www.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Reforming Small Power Systems under Political Nepal and Tooraj Jamasb This paper assesses the electricity sector reforms across small power systems make power sector reform in Nepal and similar small systems a more complex process. As international

  7. www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY

    E-Print Network [OSTI]

    Aickelin, Uwe

    valuation method (CVM) to investigate information effects in the valuation of electricity and waterwww.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY Information Effects in Valuation of Electricity and Water Service Attributes Using Contingent Valuation EPRG Working Paper 1127 Cambridge Working

  8. www.eprg.group.cam.ac.uk EPRGWORKINGPAPER

    E-Print Network [OSTI]

    Aickelin, Uwe

    factors that affect WTP for the attributes considered. Keywords Contingent Valuation Method, Willingnesswww.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Information Effects in Valuation of Electricity and Water Service Attributes Using Contingent Valuation EPRG Working Paper 1127 Cambridge Working Paper

  9. http://stir.ac.uk/4l Why study Management?

    E-Print Network [OSTI]

    Little, Tony

    http://stir.ac.uk/4l BSc(Hons) Management #12;Why study Management? Management essentially combines the flow of patients through hospital departments. Other modules include: Business Strategy, Project Management Case Studies and Energy Supply Case Study. Did you know? Excellent Management practice is required

  10. Beaming into matter and life www.cockcroft.ac.uk

    E-Print Network [OSTI]

    Crowther, Paul

    Beaming into matter and life www.cockcroft.ac.uk COCKCROFT STRATEGY MAP 2014-2020 Vision Continue and train the next generation of scientists and engineers, address societal challenges in energy · Globally Unique Skills Base · Societal Impact: Energy, Environment, Health, Security Strategic Enablers

  11. contents | print | close www.glasgow.ac.uk

    E-Print Network [OSTI]

    Guo, Zaoyang

    1 contents | print | close www.glasgow.ac.uk Gilmorehill Campus Development Framework June 2014 : Topic 4 107 Approach to Historic Assets: Sub Topics 108 · A Campus-wide Conservation Strategy 108 · Introduction 134 · Relevant Consultation Themes : Topic 7 135 Uses & Adaptability : Sub Topics 136 · Energy

  12. contents | print | close www.glasgow.ac.uk

    E-Print Network [OSTI]

    Guo, Zaoyang

    1 contents | print | close www.glasgow.ac.uk Gilmorehill Campus Development Framework FINAL : Topic 4 107 Approach to Historic Assets: Sub Topics 108 · A Campus-wide Conservation Strategy 108 · Introduction 134 · Relevant Consultation Themes : Topic 7 135 Uses & Adaptability : Sub Topics 136 · Energy

  13. www.glasgow.ac.uk/library The University Library

    E-Print Network [OSTI]

    Guo, Zaoyang

    www.glasgow.ac.uk/library The University Library for staff #12;www.facebook.com/uofglibrary twitter.com/uofglibrary instagram.com/uoglibrary Library Blog universityofglasgowlibrary.wordpress.com Welcome to the University Library Where is the Library? It's on Hillhead Street, next to the Hunterian Art Gallery, at the heart

  14. Glasgow Theses Service http://theses.gla.ac.uk/

    E-Print Network [OSTI]

    Singer, Jeremy

    transmission and the ecological context. PhD thesis. http://theses.gla.ac.uk/3768/ Copyright and moral rights first obtaining permission in writing from the Author The content must not be changed in any way or sold must be given #12;Disease transmission and the ecological context Angus Cameron BSc (Hons) This thesis

  15. FBDEditor: {ldalove, atang34, syjsmk, jbyoo}@konkuk.ac.kr

    E-Print Network [OSTI]

    }@konkuk.ac.kr : Programmable Logic Controller (PLC) . Field Programmable Gate Array (FPGA) . PLC Function Controller (PLC) Field Programmable Gate Array (FPGA) . PLC IEC 61131-3 5 (LD: Ladder diagram) . FBD Function Block(FB) . FBD PLC . FPGA Hardware Description Language

  16. Glasgow Theses Service http://theses.gla.ac.uk/

    E-Print Network [OSTI]

    Glasgow, University of

    within the acceptance of the acceleration system. Ionisation cooling is the only viable cooling technique (2011) The Muon Ionisation Cooling Experiment. PhD thesis. http://theses.gla.ac.uk/2839/ Copyright-commercial research or study, without prior permission or charge This thesis cannot be reproduced or quoted

  17. Efficiency Ratings for the Daiken AC (Americas), Inc.

    E-Print Network [OSTI]

    Efficiency Ratings for the Daiken AC (Americas), Inc. Altherma Air-to-Water Source Heat Pump System is used to provide water heating, the EF for that separate water heater shall be used for performance Description Model No. Capacity (tons) Space Heating Space Cooling SEER Water Heating Efficiency

  18. Frequency synthesis using MEMS piezoelectric resonators

    E-Print Network [OSTI]

    Calhoun, Paul Jacob, 1979-

    2004-01-01T23:59:59.000Z

    (cont.) Ultimately, this thesis presents two approaches to frequency synthesizer design. The first uses frequency windows of approximately 200 MHz. The 800 MHz to 1 GHz matching network is presented in detail along with ...

  19. FREQUENCY DEPENDENT MULTIPOLE POLARIZABILITIES OF ATOMIC SYSTEMS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1259 FREQUENCY DEPENDENT MULTIPOLE POLARIZABILITIES OF ATOMIC SYSTEMS S. I. EASA and G. C. SHUKLA et d'helium. Abstract. 2014 A variational calculation for frequency dependent multipole 1978, Classification Physics Abstracts 31.10 The calculation of multipole polarizabilities

  20. A High Frequency Isolated Current-fed Bidirectional DC/AC Converter For Grid-Tied Energy Storage System

    E-Print Network [OSTI]

    King Jet, TSENG

    2013-01-01T23:59:59.000Z

    solar photovoltaic power generation for buildings. Electrochemical battery which has acceptable power and energy density

  1. THE SELF-ADJUSTING CURRENT-FED PUSH-PULL PARALLEL RESONANT INVERTER AS A HIGH FREQUENCY AC BUS DRIVER

    E-Print Network [OSTI]

    . The power inverter is based on a Current-Fed Push-Pull Parallel-Resonant Inverter (CFPPRI), which includes

  2. Sensorless Direct Torque Control For Salient Pole PMSM Based on Extended Kalman Filter Fed By AC/DC/AC Converter

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Sensorless Direct Torque Control For Salient ­ Pole PMSM Based on Extended Kalman Filter Fed By AC is proposed. The Direct Torque Control (DTC) technique for PMSM is receiving increasing attention due on the stochastic intromission, in others words, noise. The PMSM is fed by an indirect power electronic converter

  3. Heightened tropical cyclone activity in the North Atlantic: natural variability or

    E-Print Network [OSTI]

    Webster, Peter J.

    relatively stable regimes separated by sharp transitions. Each regime has seen 50% more cyclonesHeightened tropical cyclone activity in the North Atlantic: natural variability or climate trend cyclone and hurricane frequency over the past century in the North Atlantic Ocean have occurred as three

  4. Patterns and Scales of Phytoplankton Variability in EstuarineCoastal Ecosystems

    E-Print Network [OSTI]

    next steps of comparative analysis: large year-to-year variability is a response to disturbance from-specific relative importance of disturbance, annual climatology, and nutrient enrichment. Keywords Estuaries, and it is strongly shaped (and biased) by the frequency, duration, and geographic regions of our obser- vations

  5. SYNTHESIS Disturbance-driven changes in the variability of ecological patterns and processes

    E-Print Network [OSTI]

    Fraterrigo, Jennifer

    by considering disturbance extent, frequency and intensity, as well as ecosystem recovery, and thereby capturesREVIEW AND SYNTHESIS Disturbance-driven changes in the variability of ecological patterns Understanding how disturbance shapes the dynamics of ecological systems is of fundamental importance in ecology

  6. Lecture 2: Fourier transforms and frequency response

    E-Print Network [OSTI]

    Fan, Xingzhe

    Lecture 2: Fourier transforms and frequency response Course at a glance Discrete-time signals and systems Fourier-domain representation DFT/FFT System structures Filter structures Filter design Filter z-transform Sampling and reconstruction System analysis System Fourier transforms and frequency response Frequency

  7. Analysis of core damage frequency from internal events: Peach Bottom, Unit 2

    SciTech Connect (OSTI)

    Kolaczkowski, A.M.; Lambright, J.A.; Ferrell, W.L.; Cathey, N.G.; Najafi, B.; Harper, F.T.

    1986-10-01T23:59:59.000Z

    This document contains the internal event initiated accident sequence analyses for Peach Bottom, Unit 2; one of the reference plants being examined as part of the NUREG-1150 effort by the Nuclear Regulatory Commission. NUREG-1150 will document the risk of a selected group of nuclear power plants. As part of that work, this report contains the overall core damage frequency estimate for Peach Bottom, Unit 2, and the accompanying plant damage state frequencies. Sensitivity and uncertainty analyses provided additional insights regarding the dominant contributors to the Peach Bottom core damage frequency estimate. The mean core damage frequency at Peach Bottom was calculated to be 8.2E-6. Station blackout type accidents (loss of all ac power) were found to dominate the overall results. Anticipated Transient Without Scram accidents were also found to be non-negligible contributors. The numerical results are largely driven by common mode failure probability estimates and to some extent, human error. Because of significant data and analysis uncertainties in these two areas (important, for instance, to the most dominant scenario in this study), it is recommended that the results of the uncertainty and sensitivity analyses be considered before any actions are taken based on this analysis.

  8. Renewable variable speed hybrid system 

    E-Print Network [OSTI]

    Stott, Paul Anthony

    2010-01-01T23:59:59.000Z

    generator island grids, these generators will be running at a fraction of maximum output for most of the time. A new variable speed diesel generator allows for a reduction in fuel consumption at part load compared to constant speed operation. Combining...

  9. Variable Structure Control of a

    E-Print Network [OSTI]

    Ge, Shuzhi Sam

    . INTRODUCTION Modelling and control of flexible link manipulators have been studied intensively controller for regulation of a flexible beam. Due to its simplicity and robustness to parametricVariable Structure Control of a Distributed-Parameter Flexible Beam S. S. Ge,* T. H. Lee, G. Zhu, F

  10. Operating Reserves and Variable Generation

    SciTech Connect (OSTI)

    Ela, E.; Milligan, M.; Kirby, B.

    2011-08-01T23:59:59.000Z

    This report tries to first generalize the requirements of the power system as it relates to the needs of operating reserves. It also includes a survey of operating reserves and how they are managed internationally in system operations today and then how new studies and research are proposing they may be managed in the future with higher penetrations of variable generation.

  11. Multiple frequency method for operating electrochemical sensors

    DOE Patents [OSTI]

    Martin, Louis P. (San Ramon, CA)

    2012-05-15T23:59:59.000Z

    A multiple frequency method for the operation of a sensor to measure a parameter of interest using calibration information including the steps of exciting the sensor at a first frequency providing a first sensor response, exciting the sensor at a second frequency providing a second sensor response, using the second sensor response at the second frequency and the calibration information to produce a calculated concentration of the interfering parameters, using the first sensor response at the first frequency, the calculated concentration of the interfering parameters, and the calibration information to measure the parameter of interest.

  12. A Universal Hurricane Frequency Function

    E-Print Network [OSTI]

    Ehrlich, Robert

    2010-01-01T23:59:59.000Z

    Evidence is provided that the global distribution of tropical hurricanes is principally determined by a universal function H of a single variable z that in turn is expressible in terms of the local sea surface temperature and latitude. The data-driven model presented here carries stark implications for the large increased numbers of hurricanes which it predicts for a warmer world. Moreover, the rise in recent decades in the numbers of hurricanes in the Atlantic, but not the Pacific basin, is shown to have a simple explanation in terms of the specific form of H(z), which yields larger percentage increases when a fixed increase in sea surface temperature occurs at higher latitudes and lower temperatures.

  13. Tel: +44 (0) 1603 591574 Email: business@uea.ac.uk Web: www.uea.ac.uk/business Experts model buyer behaviour

    E-Print Network [OSTI]

    Everest, Graham R

    Tel: +44 (0) 1603 591574 Email: business@uea.ac.uk Web: www.uea.ac.uk/business Experts model buyer their customers to make buying decisions. When you are in the business of printing newspapers, accurate ­ the UK's largest independently-owned regional media business ­ on a project which saw academics from

  14. Approaches to building single-stage AC/AC conversion switch-mode audio power Petar Ljusev and Michael A.E. Andersen

    E-Print Network [OSTI]

    power amplifiers with a separate power supply, it is expected that direct conversion will provide better performance. It is also quite appealing for the Active Trans- ducer (AT) [2] approach for direct conversionApproaches to building single-stage AC/AC conversion switch-mode audio power amplifiers Petar

  15. Development Office, Trinity Hall, Cambridge, CB2 1TJ www.trinhall.cam.ac.uk fundraising@trinhall.cam.ac.uk

    E-Print Network [OSTI]

    Lasenby, Joan

    Development Office, Trinity Hall, Cambridge, CB2 1TJ www.trinhall.cam.ac.uk fundraising@trinhall.cam.ac.uk Tel: 01223 766345 Fax: 01223 765157 Trinity Hall Cambridge registered charity number 1137458 Making of financial background, and we are committed to nurturing the talent of the diverse Trinity Hall community

  16. Cranial Variability in Amazonian Marmosets

    E-Print Network [OSTI]

    Aguiar, John Marshall

    2011-02-22T23:59:59.000Z

    (Callithrix, Callitrichidae) have been discovered in recent years, as well as the exceptional dwarf marmoset Callibella humilis. Most of these species were described on the basis of their pelage and presumed separation by major rivers. I performed... analyses of craniometric variables by taxa and by river basins, in order to determine if there are significant cranial distinctions between taxa separated by rivers. I analyzed quantitative cranial and mandibular characters of Callibella humilis...

  17. Prebreakdown and breakdown phenomena in large oil gaps under AC

    SciTech Connect (OSTI)

    Saker, A.; Gournay, P.; Lesaint, O.; Tobazeon, R. [CNRS, Grenoble (France). Lab. d`Electrostatique et de Materiaux Dielectriques; Trinh, N.G. [Inst. de Recherche d`Hydro-Quebec, Varennes, Quebec (Canada); Boisdon, C. [Jeumont-Schneider Transformateurs, Lyon (France)

    1996-12-31T23:59:59.000Z

    This paper presents a study of prebreakdown and breakdown phenomena under AC voltage in mineral oil in large gaps to 60 cm. The investigations presented concern the study of streamers and the measurement of breakdown voltages in rod-plane and sphere-plane gaps. Also, the influence of a contamination by solid particles in the oil has been considered. A specific breakdown mode under AC voltage is evidenced, where bursts of streamers lead to the lowest breakdown fields recorded. Numerical values of the mean field in oil required for direct or burst breakdown modes are derived from the experiments. As a consequence, the great sensitivity to the presence of particles on EHV transformers insulation with large oil gaps is pointed out.

  18. On-Chip AC self-test controller

    DOE Patents [OSTI]

    Flanagan, John D. (Rhinebeck, NY); Herring, Jay R. (Poughkeepsie, NY); Lo, Tin-Chee (Fishkill, NY)

    2009-09-29T23:59:59.000Z

    A system for performing AC self-test on an integrated circuit that includes a system clock for normal operation is provided. The system includes the system clock, self-test circuitry, a first and second test register to capture and launch test data in response to a sequence of data pulses, and a logic circuit to be tested. The self-test circuitry includes an AC self-test controller and a clock splitter. The clock splitter generates the sequence of data pulses including a long data capture pulse followed by an at speed data launch pulse and an at speed data capture pulse followed by a long data launch pulse. The at speed data launch pulse and the at speed data capture pulse are generated for a common cycle of the system clock.

  19. SNL software manual for the ACS Data Analytics Project.

    SciTech Connect (OSTI)

    Stearley, Jon R.; McLendon, William Clarence, III; Rodrigues, Arun F.; Williams, Aaron S.; Hooper, Russell Warren; Robinson, David Gerald; Stickland, Michael G.

    2011-10-01T23:59:59.000Z

    In the ACS Data Analytics Project (also known as 'YumYum'), a supercomputer is modeled as a graph of components and dependencies, jobs and faults are simulated, and component fault rates are estimated using the graph structure and job pass/fail outcomes. This report documents the successful completion of all SNL deliverables and tasks, describes the software written by SNL for the project, and presents the data it generates. Readers should understand what the software tools are, how they fit together, and how to use them to reproduce the presented data and additional experiments as desired. The SNL YumYum tools provide the novel simulation and inference capabilities desired by ACS. SNL also developed and implemented a new algorithm, which provides faster estimates, at finer component granularity, on arbitrary directed acyclic graphs.

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

    DOE Patents [OSTI]

    Muljadi, E.

    1998-08-25T23:59:59.000Z

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

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

    DOE Patents [OSTI]

    Muljadi, Eduard (Golden, CO)

    1998-01-01T23:59:59.000Z

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

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

    DOE Patents [OSTI]

    Muljadi, Eduard (Golden, CO)

    1998-08-25T23:59:59.000Z

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

  3. Variable flexure-based fluid filter

    DOE Patents [OSTI]

    Brown, Steve B.; Colston Jr., Billy W.; Marshall, Graham; Wolcott, Duane

    2007-03-13T23:59:59.000Z

    An apparatus and method for filtering particles from a fluid comprises a fluid inlet, a fluid outlet, a variable size passage between the fluid inlet and the fluid outlet, and means for adjusting the size of the variable size passage for filtering the particles from the fluid. An inlet fluid flow stream is introduced to a fixture with a variable size passage. The size of the variable size passage is set so that the fluid passes through the variable size passage but the particles do not pass through the variable size passage.

  4. ac phase noise: Topics by E-print Network

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

    perturbation methods. In bulk contrast, we find that for sufficiently small viscosity ?, the structure factor develops a peak at non-zero frequency ?, for fixed...

  5. Frequency Regulation Basics and Trends

    SciTech Connect (OSTI)

    Kirby, BJ

    2005-05-06T23:59:59.000Z

    The electric power system must address two unique requirements: the need to maintain a near real-time balance between generation and load, and the need to adjust generation (or load) to manage power flows through individual transmission facilities. These requirements are not new: vertically integrated utilities have been meeting them for a century as a normal part of conducting business. With restructuring, however, the services needed to meet these requirements, now called ''ancillary services'', are being more clearly defined. Ancillary services are those functions performed by the equipment and people that generate, control, and transmit electricity in support of the basic services of generating capacity, energy supply, and power delivery. The Federal Energy Regulatory Commission (FERC) has defined such services as those ''necessary to support the transmission of electric power from seller to purchaser given the obligations of control areas and transmitting utilities within those control areas to maintain reliable operations of the interconnected transmission system''. This statement recognizes the importance of ancillary services for both bulk-power reliability and support of commercial transactions. Balancing generation and load instantaneously and continuously is difficult because loads and generators are constantly fluctuating. Minute-to-minute load variability results from the random turning on and off of millions of individual loads. Longer-term variability results from predictable factors such as the daily and seasonal load patterns as well as more random events like shifting weather patterns. Generators also introduce unexpected fluctuations because they do not follow their generation schedules exactly and they trip unexpectedly due to a range of equipment failures. The output from wind generators varies with the wind. Storage technologies should be ideal suppliers of several ancillary services, including regulation, contingency reserves (spinning reserve, supplemental reserve, replacement reserve), and voltage support. These services are not free; in regions with energy markets, generators are paid to supply these services. In vertically integrated utilities (without energy markets) the utility incurs significant costs to supply these services. Supplying these services may be a significant business opportunity for emerging storage technologies. This report briefly explores the various ancillary services that may be of interest to storage. It then focuses on regulation, the most expensive ancillary service. It also examines the impact that increasing amounts of wind generation may have on regulation requirements, decreasing conventional regulation supplies, and the implications for energy storage.

  6. Octave Spanning Frequency Comb on a Chip

    E-Print Network [OSTI]

    Del'Haye, P; Gavartin, E; Holzwarth, R; Kippenberg, T J

    2009-01-01T23:59:59.000Z

    Optical frequency combs have revolutionized the field of frequency metrology within the last decade and have become enabling tools for atomic clocks, gas sensing and astrophysical spectrometer calibration. The rapidly increasing number of applications has heightened interest in more compact comb generators. Optical microresonator based comb generators bear promise in this regard. Critical to their future use as 'frequency markers', is however the absolute frequency stabilization of the optical comb spectrum. A powerful technique for this stabilization is self-referencing, which requires a spectrum that spans a full octave, i.e. a factor of two in frequency. In the case of mode locked lasers, overcoming the limited bandwidth has become possible only with the advent of photonic crystal fibres for supercontinuum generation. Here, we report for the first time the generation of an octave-spanning frequency comb directly from a toroidal microresonator on a silicon chip. The comb spectrum covers the wavelength range...

  7. Frequency Control Performance Measurement and Requirements

    SciTech Connect (OSTI)

    Illian, Howard F.

    2010-12-20T23:59:59.000Z

    Frequency control is an essential requirement of reliable electric power system operations. Determination of frequency control depends on frequency measurement and the practices based on these measurements that dictate acceptable frequency management. This report chronicles the evolution of these measurements and practices. As technology progresses from analog to digital for calculation, communication, and control, the technical basis for frequency control measurement and practices to determine acceptable performance continues to improve. Before the introduction of digital computing, practices were determined largely by prior experience. In anticipation of mandatory reliability rules, practices evolved from a focus primarily on commercial and equity issues to an increased focus on reliability. This evolution is expected to continue and place increased requirements for more precise measurements and a stronger scientific basis for future frequency management practices in support of reliability.

  8. Wide band stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Bashforth, M.B.; Gardner, D.; Patrick, D.; Lewallen, T.A.; Nammath, S.R.; Painter, K.D.; Vadnais, K.G.

    1996-03-12T23:59:59.000Z

    A wide band ground penetrating radar system is described embodying a method wherein a series of radio frequency signals is produced by a single radio frequency source and provided to a transmit antenna for transmission to a target and reflection therefrom to a receive antenna. A phase modulator modulates those portions of the radio frequency signals to be transmitted and the reflected modulated signal is combined in a mixer with the original radio frequency signal to produce a resultant signal which is demodulated to produce a series of direct current voltage signals, the envelope of which forms a cosine wave shaped plot which is processed by a Fast Fourier Transform Unit 44 into frequency domain data wherein the position of a preponderant frequency is indicative of distance to the target and magnitude is indicative of the signature of the target. 6 figs.

  9. Wide band stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Bashforth, Michael B. (Buellton, CA); Gardner, Duane (Santa Maria, CA); Patrick, Douglas (Santa Maria, CA); Lewallen, Tricia A. (Ventura, CA); Nammath, Sharyn R. (Santa Barbara, CA); Painter, Kelly D. (Goleta, CA); Vadnais, Kenneth G. (Alexandria, VA)

    1996-01-01T23:59:59.000Z

    A wide band ground penetrating radar system (10) embodying a method wherein a series of radio frequency signals (60) is produced by a single radio frequency source (16) and provided to a transmit antenna (26) for transmission to a target (54) and reflection therefrom to a receive antenna (28). A phase modulator (18) modulates those portion of the radio frequency signals (62) to be transmitted and the reflected modulated signal (62) is combined in a mixer (34) with the original radio frequency signal (60) to produce a resultant signal (53) which is demodulated to produce a series of direct current voltage signals (66) the envelope of which forms a cosine wave shaped plot (68) which is processed by a Fast Fourier Transform unit 44 into frequency domain data (70) wherein the position of a preponderant frequency is indicative of distance to the target (54) and magnitude is indicative of the signature of the target (54).

  10. Method and apparatus for monitoring the rotating frequency of de-energized induction motors

    DOE Patents [OSTI]

    Mikesell, Harvey E. (McMurray, PA); Lucy, Eric (Murrysville, PA)

    1998-01-01T23:59:59.000Z

    The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor.

  11. Method and apparatus for monitoring the rotating frequency of de-energized induction motors

    DOE Patents [OSTI]

    Mikesell, H.E.; Lucy, E.

    1998-02-03T23:59:59.000Z

    The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor. 6 figs.

  12. System and method for determining stator winding resistance in an AC motor

    DOE Patents [OSTI]

    Lu, Bin (Kenosha, WI); Habetler, Thomas G. (Snellville, GA); Zhang, Pinjia (Atlanta, GA); Theisen, Peter J. (West Bend, WI)

    2011-05-31T23:59:59.000Z

    A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.

  13. Frequency Instability Problems in North American Interconnections

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

    cycle CFC Constant frequency control CPS Control Performance Standards DC Direct Current EI Eastern Interconnection EIA Energy Information Agency ERCOT Electric Reliability...

  14. Programmable AC power supply for simulating power transient expected in fusion reactor

    SciTech Connect (OSTI)

    Halimi, B. [Seoul National Univ., Seoul 151-744 (Korea, Republic of); Suh, K. Y. [Seoul National Univ., Seoul 151-744 (Korea, Republic of); PHILOSOPHIA, 1 Gwanak Ro, Gwanak Gu, Seoul 151-744 (Korea, Republic of)

    2012-07-01T23:59:59.000Z

    This paper focus on control engineering of the programmable AC power source which has capability to simulate power transient expected in fusion reactor. To generate the programmable power source, AC-AC power electronics converter is adopted to control the power of a set of heaters to represent the transient phenomena of heat exchangers or heat sources of a fusion reactor. The International Thermonuclear Experimental Reactor (ITER) plasma operation scenario is used as the basic reference for producing this transient power source. (authors)

  15. Nonlinear modal interaction in HVDC/AC power systems with dc power modulation

    SciTech Connect (OSTI)

    Ni, Y.X. [Tsinghua Univ., Beijing (China)] [Tsinghua Univ., Beijing (China); Vittal, V.; Kliemann, W.; Fouad, A.A. [Iowa State Univ., Ames, IA (United States)] [Iowa State Univ., Ames, IA (United States)

    1996-11-01T23:59:59.000Z

    In this paper investigation of nonlinear modal interaction using the normal form of vector fields technique is extended to HVDC/AC power systems with dc power modulation. The ac-dc interface equations are solved to form a state space model with second order approximation. Using the normal form technique, the system`s nonlinear dynamic characteristics are obtained. The proposed approach is applied to a 4-generator HVDC/AC test power system, and compare with the time domain solution.

  16. A reduction of proof complexity to computational complexity for AC0

    E-Print Network [OSTI]

    Krajíèek, Jan

    obtained. Ajtai [3, 4, 5], Beame 1 #12;et.al.[6] and Buss et.al.[9] proved lower bounds for AC0 Frege a prime p do not polyno- mially simulate polynomial calculus over Fp, and recently Buss, Kolodziejczyk by the depth 3 AC0 [p] system. Also, Buss et.al.[9] showed that the AC0 [p] Frege systems are polynomially

  17. Variable Temperature STM/AFM | EMSL

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

    STMAFM Variable Temperature STMAFM EMSL's ultra-high vacuum, variable-temperature scanning probe microscope system, or UHV VT SPM, is a state-of-the-art surface science tool...

  18. Interannual variability in tropospheric nitrous oxide

    E-Print Network [OSTI]

    Thompson, R. L.

    Observations of tropospheric N2O mixing ratio show significant variability on interannual timescales (0.2?ppb, 1 standard deviation). We found that interannual variability in N2O is weakly correlated with that in CFC-12 ...

  19. Thermoacoustic tomography, variable sound speed Plamen Stefanov

    E-Print Network [OSTI]

    Stefanov, Plamen

    Thermoacoustic tomography, variable sound speed Plamen Stefanov Purdue University Based on a joint work with Gunther Uhlmann Plamen Stefanov (Purdue University ) Thermoacoustic tomography, variable sound speed 1 / 18 #12;Formulation Main Problem Thermoacoustic Tomography In thermoacoustic tomography

  20. ac motor control: Topics by E-print Network

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

    Summary: ??Permanent magnet Brushless DC motor drives are being employed in newlinemany variable speed applications due to their high efficiency, silent operation, newlinecompact...

  1. ac motor drives: Topics by E-print Network

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

    - TxSpace Summary: and Quantitative Account Gear-Train Servo Error Types. IV. DC VARIABLE SPEED MOTOR DRIVE DESIGN CONSIDERATIONS AND RFALIZATION. Introduction. 27 29 30...

  2. ac motor controller: Topics by E-print Network

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

    Summary: ??Permanent magnet Brushless DC motor drives are being employed in newlinemany variable speed applications due to their high efficiency, silent operation, newlinecompact...

  3. ac motor drive: Topics by E-print Network

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

    - TxSpace Summary: and Quantitative Account Gear-Train Servo Error Types. IV. DC VARIABLE SPEED MOTOR DRIVE DESIGN CONSIDERATIONS AND RFALIZATION. Introduction. 27 29 30...

  4. Broadband Spectra and Variability of BL Lacertae in 2000

    E-Print Network [OSTI]

    M. Boettcher; H. D. Aller; M. F. Aller; O. Mang; C. M. Raiteri; M. Ravasio; G. Tagliaferri; H. Teraesranta; M. Villata

    2002-03-21T23:59:59.000Z

    We have organized an extensive multiwavelength campaign on BL Lacertae in the second half of 2000. Simultaneous or quasi-simultaneous observations were taken at radio frequencies, in the optical - carried out by the WEBT collaboration -, in X-rays - using BeppoSAX and RXTE -, and at VHE gamma-rays with the CAT and HEGRA Cherenkov telescope facilities. In this paper, we are presenting first results from this campaign. The WEBT optical campaign achieved an unprecedented time coverage, virtually continuous over several 10 - 20 hour segments, and revealed intraday variability on time scales of ~ 1.5 hours. The X-ray observations of Nov. 1 - 2, 2000, revealed significant variability on similar time scales, and provided evidence for the synchrotron spectrum extending out to ~ 10 keV during that time. At higher energies, the onset of the hard power-law commonly observed in radio-loud quasars and radio-selected BL Lac objects is seen. From the energy-resolved X-ray variability patterns, we find evidence that electron cooling might not be dominated by one single radiation mechanism; rather, a combination of synchrotron and Compton cooling seems to be required.

  5. Broadband Spectra and Variability of BL Lacertae in 2000

    E-Print Network [OSTI]

    Böttcher, M; Aller, M F; Mang, O; Raiteri, C M; Ravasio, M; Tagliaferri, G; Teraesranta, H; Villata, M

    2002-01-01T23:59:59.000Z

    We have organized an extensive multiwavelength campaign on BL Lacertae in the second half of 2000. Simultaneous or quasi-simultaneous observations were taken at radio frequencies, in the optical - carried out by the WEBT collaboration -, in X-rays - using BeppoSAX and RXTE -, and at VHE gamma-rays with the CAT and HEGRA Cherenkov telescope facilities. In this paper, we are presenting first results from this campaign. The WEBT optical campaign achieved an unprecedented time coverage, virtually continuous over several 10 - 20 hour segments, and revealed intraday variability on time scales of ~ 1.5 hours. The X-ray observations of Nov. 1 - 2, 2000, revealed significant variability on similar time scales, and provided evidence for the synchrotron spectrum extending out to ~ 10 keV during that time. At higher energies, the onset of the hard power-law commonly observed in radio-loud quasars and radio-selected BL Lac objects is seen. From the energy-resolved X-ray variability patterns, we find evidence that electron...

  6. DE-AC05-00OR22725 Modification No. 341

    E-Print Network [OSTI]

    Government) to enter into Contract DE-AC05-990R22725 for the Management and Operationofthe OakRidge National

  7. DE-AC05-00OR22725 Modification No. 341

    E-Print Network [OSTI]

    and the Contractor entered into Agreement No. DE-AC05-000R22725, or a Supplemental Agreement(s) thereto, providing

  8. Effects of free-electron-laser field fluctuations on the frequency response of driven atomic resonances

    E-Print Network [OSTI]

    G. M. Nikolopoulos; P. Lambropoulos

    2012-09-11T23:59:59.000Z

    We study the effects of field fluctuations on the total yields of Auger electrons, obtained in the excitation of neutral atoms to a core-excited state by means of short-wavelength free-electron-laser pulses. Beginning with a self-contained analysis of the statistical properties of fluctuating free-electron-laser pulses, we analyse separately and in detail the cases of single and double Auger resonances, focusing on fundamental phenomena such as power broadening and ac Stark (Autler-Townes) splitting. In certain cases, field fluctuations are shown to influence dramatically the frequency response of the resonances, whereas in other cases the signal obtained may convey information about the bandwidth of the radiation as well as the dipole moment between Auger states.

  9. Gravitational Bending of Light with Frequency Shifts

    E-Print Network [OSTI]

    P. D. Morley

    1993-11-15T23:59:59.000Z

    Non-static gravitational fields generally introduce frequency shifts when bending light. In this paper, I discuss the frequency shifts induced in the bending of light by moving masses. As examples, I treat the recently discovered high-velocity pulsar PSR 2224+65 and a typical Einstein ring.

  10. Distributed Online Frequency Assignment in Cellular Networks ?

    E-Print Network [OSTI]

    Devoto, Stephen H.

    Distributed Online Frequency Assignment in Cellular Networks ? (Extended Abstract) Jeannette a general framework for studying distributed online frequency assignment in cellular networks. The problem at the corresponding network cell. In this setting, we present several distributed online algorithms for this problem

  11. Nucleotide Frequency Variation Across Human Genes

    E-Print Network [OSTI]

    Majewski, Jacek

    Nucleotide Frequency Variation Across Human Genes Elizabeth Louie, Jurg Ott, and Jacek Majewski1 The Rockefeller University, New York, New York 10021, USA The frequencies of individual nucleotides exhibit significant fluctuations across eukaryotic genes. In this paper, we investigate nucleotide variation across

  12. A Dual Tone Multiple Frequency receiver using a multiplexed OTA-C filter frequency detection architecture

    E-Print Network [OSTI]

    Garcia, Gerald William

    1988-01-01T23:59:59.000Z

    A DUAL TONE MULTIPLE FREQUENCY RECEIVER USING A MULTIPLEXED OTA-C FILTER FREQUENCY DETECTION ARCHITECTURE A Thesis by GERALD WILLIAM GARCIA Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 1988 Major Subject: Electrical Engineering A DUAL TONE MULTIPLE FREQUENCY RECEIVER USING A MULTIPLEXED OTA-C FILTER FREQUENCY DETECTION ARCHITECTURE A Thesis by GERALD WILLIAM GARCIA Approved as to style...

  13. Design of dual frequency interferometric SAR

    SciTech Connect (OSTI)

    Kim, Y.; Edelstein, W.; Caro, E. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

    1996-03-01T23:59:59.000Z

    Using a spaceborne interferometric SAR, it is possible to produce a high resolution global topographic map with a height accuracy of several meters. However, frequency selection of the interferometric SAR is rather complicated due to interferometric phenomenology and atmospheric effects. In this paper, we propose a dual frequency interferometric SAR to achieve better understanding of interferometric height (especially for penetrable medium) and corresponding calibration and to remove the atmospheric effects. The selected frequencies are L- and Ku- bands. We also present a radar design and show that a light weight and efficient SAR can be designed using new technologies and dual frequency advantages even with two frequency radars in a single spacecraft. {copyright} {ital 1996 American Institute of Physics.}

  14. Randomness and Earth climate variability

    E-Print Network [OSTI]

    Levinshtein, Michael E; Dmitriev, Alexander P; Shmakov, Pavel M

    2015-01-01T23:59:59.000Z

    Paleo-Sciences including palaeoclimatology and palaeoecology have accumulated numerous records related to climatic changes. The researchers have usually tried to identify periodic and quasi-periodic processes in these paleoscientific records. In this paper, we show that this analysis is incomplete. As follows from our results, random processes, namely processes with a single-time-constant (noise with a Lorentzian noise spectrum), play a very important and, perhaps, a decisive role in numerous natural phenomena. For several of very important natural phenomena the characteristic time constants are very similar and equal to (5-8)x10^3 years. However, this value is not universal. For example, the spectral density fluctuations of the atmospheric radiocarbon 14C are characterized by a Lorentzian with time constant 300 years. The frequency dependence of spectral density fluctuations for benthic 18O records contains two Lorentzians with time constans 8000 years and > 105 years.

  15. The frequency of planets in multiple systems

    E-Print Network [OSTI]

    M. Bonavita; S. Desidera

    2007-03-29T23:59:59.000Z

    The frequency of planets in binaries is an important issue in the field of extrasolar planet studies, because of its relevance in estimating of the global planet population of our Galaxy and the clues it can give to our understanding of planet formation and evolution. However, only preliminary estimates are available in the literature. We analyze and compare the frequency of planets in multiple systems to the frequency of planets orbiting single stars. We also try to highlight possible connections between the frequency of planets and the orbital parameters of the binaries (such as the periastron and mass ratio.) A literature search was performed for binaries and multiple systems among the stars of the sample with uniform planet detectability defined by Fischer & Valenti (2005), and 202 of the 850 stars of the sample turned out to be binaries, allowing a statistical comparison of the frequency of planets in binaries and single stars and a study of the run of the planet frequency as a function of the binary separation. We found that the global frequency of planets in the binaries of the sample is not statistically different from that of planets in single stars. Even conservatively taking the probable incompleteness of binary detection in our sample into account, we estimate that the frequency of planets in binaries can be no more than a factor of three lower than that of planets in single stars. There is no significant dependence of planet frequency on the binary separation, except for a lower value of frequency for close binaries. However, this is probably not as low as required to explain the presence of planets in close binaries only as the result of modifications of the binary orbit after the planet formation.

  16. E4.18 Radio Frequency Electronics Copyright 2006 Dr Stepan Lucyszyn Frequency Spectrum

    E-Print Network [OSTI]

    Papavassiliou, Christos

    Applications Phased-array radar Electronic warfare (e.g. Electronic Surveillance Measures, ECM, ECCM, decoysE4.18 Radio Frequency Electronics Copyright © 2006 Dr Stepan Lucyszyn Frequency Spectrum and Applications #12;E4.18 Radio Frequency Electronics Copyright © 2006 Dr Stepan Lucyszyn #12;E4.18 Radio

  17. Determination of the effect of harmonics on pipe-type power cable AC/DC resistance ratio

    SciTech Connect (OSTI)

    Palmer, J.A.; Degeneff, R.C. (Rensselaer Polytechnic Inst., Troy, NY (United States)); McKernan, T.M.; Halleran, T.M. (Consolidated Edison Co. of NY, Inc., New York (United States))

    1993-03-01T23:59:59.000Z

    This paper presents a closed form expression to compute the AC/CD resistance ratio of HPFF (High Pressure Fluid Filled) pipe-type cable in the presence of harmonics. Industry currently computes this factor, which is a significant part in assessing the current carrying capacity of a system, with the assumption that the currents are purely sinusoidal at 60 Hz. However, as levels of harmonics increase on power systems, concern for the effect of harmonics on system ampacities rises, and that effect has already been discussed for distribution systems. This paper develops a closed form hybrid of the resistance ratio equations presented by Neher and McGrath, and compares the results with measured data at 60 Hz. At present there is no measured data available for the resistance ratio at higher frequencies, so a two dimensional finite element model is developed to view the effect of frequency on the resistance ratio. A discussion is given on the effect of a specific harmonics scenario on the resistance ratio of a given system, and results are presented for some example systems. The paper also discusses the validity and characteristics of each method.

  18. Calculation of HVDC-converter harmonics in frequency domain with regard to asymmetries and comparison with time domain simulations

    SciTech Connect (OSTI)

    Rittiger, J. [Siemens AG, Erlangen (Germany)] [Siemens AG, Erlangen (Germany); Kulicke, B. [Technische Univ. Berlin (Germany)] [Technische Univ. Berlin (Germany)

    1995-10-01T23:59:59.000Z

    In order to study the effects of large HVDC converters to the feeding ac networks, it is of importance to explain and to calculate harmonic phenomena which are a result of converter operation. During commissioning of real HVDC converters it could be seen, that harmonics resulting from unsymmetries in the system voltages or from unsymmetries in converter operation led to significant difficulties concerning the system design. For this reason, not only the effects of characteristic but also the effects of noncharacteristic converter harmonics must be taken into account. The aim is to describe the steady state harmonic behavior of the converter. The harmonic spectra are not determined by time domain analysis but instead the solution is found by frequency domain calculations. This can result in reduced calculation time in comparison to conventional fourier analysis of the time functions. The converter is interpreted as an amplitude modulator with voltage and current converter functions which describe the coupling of the dc circuit and the ac network through the converter. To verify the theory, comparison of frequency domain with time domain calculations were carried out.

  19. Variable residence time vortex combustor

    DOE Patents [OSTI]

    Melconian, Jerry O. (76 Beaver Rd., Reading, MA 01867)

    1987-01-01T23:59:59.000Z

    A variable residence time vortex combustor including a primary combustion chamber for containing a combustion vortex, and a plurality of louvres peripherally disposed about the primary combustion chamber and longitudinally distributed along its primary axis. The louvres are inclined to impel air about the primary combustion chamber to cool its interior surfaces and to impel air inwardly to assist in driving the combustion vortex in a first rotational direction and to feed combustion in the primary combustion chamber. The vortex combustor also includes a second combustion chamber having a secondary zone and a narrowed waist region in the primary combustion chamber interconnecting the output of the primary combustion chamber with the secondary zone for passing only lower density particles and trapping higher density particles in the combustion vortex in the primary combustion chamber for substantial combustion.

  20. Variable delivery, fixed displacement pump

    DOE Patents [OSTI]

    Sommars, Mark F. (Sparland, IL)

    2001-01-01T23:59:59.000Z

    A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.

  1. Continuously variable focal length lens

    DOE Patents [OSTI]

    Adams, Bernhard W; Chollet, Matthieu C

    2013-12-17T23:59:59.000Z

    A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.

  2. Variable ratio regenerative braking device

    DOE Patents [OSTI]

    Hoppie, Lyle O. (Birmingham, MI)

    1981-12-15T23:59:59.000Z

    Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

  3. Probing Mott lobes via the AC Josephson effect

    E-Print Network [OSTI]

    M. X. Huo; Ying Li; Z. Song; C. P. Sun

    2008-03-04T23:59:59.000Z

    The alternating-current (AC) Josephson effect is studied in a system consisting of two weakly coupled Bose Hubbard models. In the framework of the mean field theory, Gross-Pitaevskii equations show that the amplitude of the Josephson current is proportional to the product of superfluid order parameters. In addition, the chemical potential--current relation for a small size system is obtained via the exact numerical computation. This allows us to propose a feasible experimental scheme to measure the Mott lobes of the quantum phase transition.

  4. Analysis of the Irregular Pulsations of AC Her

    E-Print Network [OSTI]

    Z. Kollath; J. R. Buchler; T. Serre; J. Mattei

    1997-07-08T23:59:59.000Z

    The AAVSO lightcurve data of the irregularly pulsating star AC Herculis of the RV Tau class are analysed. The lightcurve is shown to be incompatible with a periodic, or even multiperiodic pulsation, even if allowance is made for evolution. Instead the best explanation is that the irregularly alternating cycles are a manifestation of low dimensional chaos. The lightcurve is found to be generated by a 3 or 4 dimensional dynamics -- 3 or 4 first order ODEs. The (Lyapunov) fractal dimension of the underlying dynamic attractor is computed to be d_L ~ 2.2, smaller than the value of d_L ~ 3.1 found for R Sct.

  5. Characterization of Cardio signals by time-frequency domain analysis

    E-Print Network [OSTI]

    Sayan Mukherjee; Sanjay Kumar Palit; Santo Banerjee; MRK Ariffin; Lamberto Rondoni; Dilip Kumar Bhattacharya

    2014-09-04T23:59:59.000Z

    Long term behavior of nonlinear deterministic continuous time signals can be studied in terms of their reconstructed attractors. Reconstructed attractors of a continuous signal are meant to be topologically equivalent representations of the dynamics of the unknown dynamical system which generates the signal. Sometimes, geometry of the attractor or its complexity may give important information on the system of interest. However, if the trajectories of the attractor behave as if they are not coming from continuous system or there exists many spike like structures on the path of the system trajectories, then there is no way to characterize the shape of the attractor. In this article, the traditional attractor reconstruction method is first used for two types of ECG signals: Normal healthy persons (NHP) and Congestive Heart failure patients (CHFP). As common in such a framework, the reconstructed attractors are not at all well formed and hence it is not possible to adequately characterize their geometrical features. Thus, we incorporate frequency domain information to the given time signals. This is done by transforming the signals to a time frequency domain by means of suitable Wavelet transforms (WT). The transformed signal concerns two non homogeneous variables and is still quite difficult to use to reconstruct some dynamics out of it. By applying a suitable mapping, this signal is further converted into integer domain and a new type of 3D plot, called integer lag plot, which characterizes and distinguishes the ECG signals of NHP and CHFP, is finally obtained.

  6. Harnessing high-dimensional hyperentanglement through a biphoton frequency comb

    E-Print Network [OSTI]

    Zhenda Xie; Tian Zhong; Sajan Shrestha; XinAn Xu; Junlin Liang; Yan-Xiao Gong; Joshua C. Bienfang; Alessandro Restelli; Jeffrey H. Shapiro; Franco N. C. Wong; Chee Wei Wong

    2015-06-13T23:59:59.000Z

    Quantum entanglement is a fundamental resource for secure information processing and communications, where hyperentanglement or high-dimensional entanglement has been separately proposed towards high data capacity and error resilience. The continuous-variable nature of the energy-time entanglement makes it an ideal candidate for efficient high-dimensional coding with minimal limitations. Here we demonstrate the first simultaneous high-dimensional hyperentanglement using a biphoton frequency comb to harness the full potential in both energy and time domain. The long-postulated Hong-Ou-Mandel quantum revival is exhibited, with up to 19 time-bins, 96.5% visibilities. We further witness the high-dimensional energy-time entanglement through Franson revivals, which is observed periodically at integer time-bins, with 97.8% visibility. This qudit state is observed to simultaneously violate the generalized Bell inequality by up to 10.95 deviations while observing recurrent Clauser-Horne-Shimony-Holt S-parameters up to 2.76. Our biphoton frequency comb provides a platform in photon-efficient quantum communications towards the ultimate channel capacity through energy-time-polarization high-dimensional encoding.

  7. 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 ...

  8. For information on current fee levels, see: www.strath.ac.uk/registry/students/finance

    E-Print Network [OSTI]

    Mottram, Nigel

    Fees For information on current fee levels, see: www.strath.ac.uk/registry/students/finance How Enquiries can be made to either of the following in the Department of Accounting & Finance: Professor Dick Davies Course Director, Investment & Finance t: +44 (0)141 548 3710 e: jr.davies@strath.ac.uk Barbara

  9. Contract Number: DE-AC05-76RL01830 Modification M881

    E-Print Network [OSTI]

    Contract Number: DE-AC05-76RL01830 Modification M881 B-i Part I ­ The Schedule Section B Supplies.......................................................1 #12;Contract Number: DE-AC05-76RL01830 Modification M881 B-1 B­1 Designation of Work) [M881] B­3 Estimated Fee Base and Total Available Performance Fees In FY12, the total available

  10. Lurching towards markets for power: China's electricity policy 19852007 Xiaoli Zhao a,c,

    E-Print Network [OSTI]

    Lyon, Thomas P.

    Institute for Low Carbon Economy and Trade, North China Electric Power University, Beijing, China a r t i cLurching towards markets for power: China's electricity policy 1985­2007 Xiaoli Zhao a,c, , Thomas P. Lyon b , Cui Song a,c a School of Economics and Management, North China Electric Power University

  11. Bone Motion Analysis From Dynamic MRI: Ac-quisition and Tracking

    E-Print Network [OSTI]

    Gilles, Benjamin

    of mechanical overload, impingement or femoral head instability. For both diagnosis and surgical planning, an acBone Motion Analysis From Dynamic MRI: Ac- quisition and Tracking INTRODUCTION Periacetabular- curate estimate of hip joint bone motion is required. Orthopedists can use animated 3D models, prior

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

    E-Print Network [OSTI]

    Teodorescu, Remus

    Sistemes Automàtica i Informàtica Industrial Universitat Politècnica de Catalunya Abstract. In this paper, parallel-connected bidirectional converters for AC and DC hybrid microgrid application energy sources [3-6]. A hybrid microgrid can be made up of distributed renewable source, AC and DC common

  13. 80 IAEI NEWS May . June 2012 www.iaei.org Microinverters and ac Pv Modules

    E-Print Network [OSTI]

    Johnson, Eric E.

    and code require- ments. However, they are different from the typical PV string inverters that use multiple80 IAEI NEWS May . June 2012 www.iaei.org Microinverters and ac Pv Modules M icroinverters and AC PV modules are becom- ing very common in residential and small commercial PV systems. See photos 1

  14. Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films and

    E-Print Network [OSTI]

    Shaw, Leah B.

    Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films magnetic field. We study the interaction behavior of YBCO thin films in an ac transport current and a dc the calibrated field profiles. The current density evolution in YBCO thin films is studied by TRMOI as a function

  15. The Hybrid Power Flow Controller A New Concept for Flexible AC Transmission

    E-Print Network [OSTI]

    Lehn, Peter W.

    large and costly projects. Over the years, environmental, right­of­way, and cost prob- lems have delayedThe Hybrid Power Flow Controller A New Concept for Flexible AC Transmission Jovan Z. Bebic Electric flow controller topologies are proposed for flexible AC transmission systems (FACTS). The first one

  16. Ultrafast high-pressure AC electro-osmotic pumps for portable biomedical microfluidics

    E-Print Network [OSTI]

    Bazant, Martin Z.

    Ultrafast high-pressure AC electro-osmotic pumps for portable biomedical microfluidics Chien details the development of an integrated AC electro-osmotic (ACEO) microfluidic pump for dilute (100 mM) biological solutions in separate microfluidic devices, with potential applications in portable

  17. Dumbarton Express Line DB heading to Stanford Oval. AC Transit Line U on Palm Drive.

    E-Print Network [OSTI]

    Dumbarton Express Line DB heading to Stanford Oval. AC Transit Line U on Palm Drive. Photo: Karl Nielsen Photo: Dong Wang Schedules: AC Transit Line U Dumbarton Express Line DB Connections with BART Transit Line U Line U provides express service between Stanford and the Fremont BART station. Other East

  18. * jafleeman@aep.com EHV AC and HVDC Transmission Working Together to Integrate Renewable Power

    E-Print Network [OSTI]

    McCalley, James D.

    * jafleeman@aep.com EHV AC and HVDC Transmission Working Together to Integrate Renewable Power J. A current (EHV AC) and high voltage direct current (HVDC) transmission systems and advocates a hybrid as a high capacity platform for system integration. HVDC transmission offers express, efficient delivery

  19. Fabrication of Superhydrophobic Fiber Coatings by DC-Biased AC-Electrospinning

    E-Print Network [OSTI]

    Tafreshi, Hooman Vahedi

    Fabrication of Superhydrophobic Fiber Coatings by DC-Biased AC-Electrospinning Fredrick O. Ochanda DC-biased AC-electrospinning. Superhydrophobic surfaces with water contact angles greater than 150 on superhydrophobicity. VC 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 1112­1119, 2012 Key words: superhydrophobic

  20. Fabrication of Superhydrophobic Fiber Coatings by DC-Biased AC-Electrospinning

    E-Print Network [OSTI]

    Tafreshi, Hooman Vahedi

    Fabrication of Superhydrophobic Fiber Coatings by DC-Biased AC-Electrospinning Fredrick O. Ochanda DC-biased AC-electrospinning. Superhydrophobic surfaces with water contact angles greater than 150 Superhydrophobicity is achieved by combining nano- or microscale roughness with a low-surface free energy material

  1. NERC Presentation: Accommodating High Levels of Variable Generation...

    Office of Environmental Management (EM)

    of variable electricity eneration. Variable resources are types of electric power generation that rely on an uncontrolled, "variable" fuel (e.g. wind, sunlight, waves, tidal...

  2. AUTOMATIC VARIABLE VENTILATION CONTROL SYSTEMS BASED ON AIR QUALITY DETECTION

    E-Print Network [OSTI]

    Turiel, Isaac

    2011-01-01T23:59:59.000Z

    ~saon Automatic Variable Ventilation Control Systems Based79-3 Automatic variable ventilation control systems based onof automatic variable ventilation control systems, result in

  3. Multi-mode radio frequency device

    DOE Patents [OSTI]

    Gilbert, Ronald W. (Morgan Hill, CA); Carrender, Curtis Lee (Morgan Hill, CA); Anderson, Gordon A. (Benton City, WA); Steele, Kerry D. (Kennewick, WA)

    2007-02-13T23:59:59.000Z

    A transponder device having multiple modes of operation, such as an active mode and a passive mode, wherein the modes of operation are selected in response to the strength of a received radio frequency signal. A communication system is also provided having a transceiver configured to transmit a radio frequency signal and to receive a responsive signal, and a transponder configured to operate in a plurality of modes and to activate modes of operation in response to the radio frequency signal. Ideally, each mode of operation is activated and deactivated independent of the other modes, although two or more modes may be concurrently operational.

  4. High power radio frequency attenuation device

    DOE Patents [OSTI]

    Kerns, Quentin A. (Bloomingdale, IL); Miller, Harold W. (Winfield, IL)

    1984-01-01T23:59:59.000Z

    A resistor device for attenuating radio frequency power includes a radio frequency conductor connected to a series of fins formed of high relative magnetic permeability material. The fins are dimensional to accommodate the skin depth of the current conduction therethrough, as well as an inner heat conducting portion where current does not travel. Thermal connections for air or water cooling are provided for the inner heat conducting portions of each fin. Also disclosed is a resistor device to selectively alternate unwanted radio frequency energy in a resonant cavity.

  5. The frequency spectrum of the Casimir effect

    SciTech Connect (OSTI)

    Lang, Andrew S.I.D. [Computer Science and Mathematics Department, Oral Roberts University, Tulsa, Oklahoma 74171 (United States)

    2005-10-01T23:59:59.000Z

    The frequency spectrum of the Casimir effect between parallel plates is studied. Calculations are performed for both the massless scalar field and the electromagnetic field cases, first using a spectral weight function, and then via the Fourier transform of the renormalized expectation of the Casimir energy-momentum operator. The Casimir force is calculated using the spectrum for two plates which are perfectly transparent in a frequency band. The result of this calculation suggests a way to detect the frequency spectrum of the Casimir effect.

  6. Turbine bucket natural frequency tuning rib

    DOE Patents [OSTI]

    Wang, John Zhiqiang (Greenville, SC); Norton, Paul Francis (Greenville, SC); Barb, Kevin Joseph (Halfmoon, NY); Jacala, Ariel Caesar-Prepena (Simpsonville, SC)

    2002-01-01T23:59:59.000Z

    A tuning rib is added preferably in the aft cavity of a cored turbine bucket to alter the bucket's natural frequencies. The tuning rib may be a solid rib or a segmented rib and is particularly suited for altering high order frequency modes such as 2T, 4F and 1-3S. As such, detrimental crossings of natural bucket frequencies and gas turbine stimuli can be avoided to thereby improve the reliability of a gas turbine without impacting other features of the bucket that are important to the performance of the gas turbine.

  7. Cost vs. performance ... Gwyn Griffiths email: gxg@noc.soton.ac.uk http://www.noc.soton.ac.uk/OED/gxg/

    E-Print Network [OSTI]

    Griffiths, Gwyn

    and safety-related costs are estimated to be 25% of the cost of the capital items. End of life disposal cost will be 5% of the capital cost. #12;Cost vs. performance ... Gwyn Griffiths email: gxg@noc.soton.ac.uk http://www.noc.soton.ac.uk/OED/gxg/ Cost & performance of Li-Po secondary batteries Component Capital cost Amortised cost per kWh Cost per

  8. RELATIONSHIP BETWEEN LOW AND HIGH FREQUENCIES IN {delta} SCUTI STARS: PHOTOMETRIC KEPLER AND SPECTROSCOPIC ANALYSES OF THE RAPID ROTATOR KIC 8054146

    SciTech Connect (OSTI)

    Breger, M.; Robertson, P. [Department of Astronomy, University of Texas, Austin, TX 78712 (United States); Fossati, L. [Department of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Balona, L. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa); Kurtz, D. W. [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Bohlender, D. [Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Lenz, P. [N. Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, 00-716 Warszawa (Poland); Mueller, I.; Lueftinger, Th. [Institut fuer Astronphysik der Universitaet Wien, Tuerkenschanzstr. 17, A-1180 Wien (Austria); Clarke, Bruce D. [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Hall, Jennifer R.; Ibrahim, Khadeejah A. [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2012-11-01T23:59:59.000Z

    Two years of Kepler data of KIC 8054146 ({delta} Sct/{gamma} Dor hybrid) revealed 349 statistically significant frequencies between 0.54 and 191.36 cycles day{sup -1} (6.3 {mu}Hz to 2.21 mHz). The 117 low frequencies cluster in specific frequency bands, but do not show the equidistant period spacings predicted for gravity modes of successive radial order, n, and reported for at least one other hybrid pulsator. The four dominant low frequencies in the 2.8-3.0 cycles day{sup -1} (32-35 {mu}Hz) range show strong amplitude variability with timescales of months and years. These four low frequencies also determine the spacing of the higher frequencies in and beyond the {delta} Sct pressure-mode frequency domain. In fact, most of the higher frequencies belong to one of three families with spacings linked to a specific dominant low frequency. In the Fourier spectrum, these family regularities show up as triplets, high-frequency sequences with absolutely equidistant frequency spacings, side lobes (amplitude modulations), and other regularities in frequency spacings. Furthermore, within two families the amplitude variations between the low and high frequencies are related. We conclude that the low frequencies (gravity modes, rotation) and observed high frequencies (mostly pressure modes) are physically connected. This unusual behavior may be related to the very rapid rotation of the star: from a combination of high- and low-resolution spectroscopy we determined that KIC 8054146 is a very fast rotator ({upsilon} sin i = 300 {+-} 20 km s{sup -1}) with an effective temperature of 7600 {+-} 200 K and a surface gravity log g of 3.9 {+-} 0.3. Several astrophysical ideas explaining the origin of the relationship between the low and high frequencies are explored.

  9. COUNTRY INSTITUTION DATE WEB ADDRESS IRAN University of Art Isfahn 08.03.2007 http://www.aui.ac.ir

    E-Print Network [OSTI]

    Di Pillo, Gianni

    COUNTRY INSTITUTION DATE WEB ADDRESS IRAN University of Art Isfahn 08.03.2007 http://www.aui.ac.ir IRAN Isfahn University of Technology 08.03.2007 http://www.iut.ac.ir IRAN The University of Isfahn 15/03/2011 http://www.ui.ac.ir IRAN Shahid Bahonar University of Kermn 06.06.2005 http

  10. Developing high-frequency equities trading models

    E-Print Network [OSTI]

    Infantino, Leandro Rafael

    2010-01-01T23:59:59.000Z

    The purpose of this paper is to show evidence that there are opportunities to generate alpha in the high frequency environment of the US equity market, using Principal Component Analysis (PCA hereafter) as a basis for short ...

  11. Security approaches for Radio Frequency Identification systems

    E-Print Network [OSTI]

    Foley, Joseph Timothy, 1976-

    2007-01-01T23:59:59.000Z

    In this thesis, I explore the challenges related to the security of the Electronic Product Code (EPC) class of Radio Frequency Identification (RFID) tags and associated data. RFID systems can be used to improve supply chain ...

  12. Distributed vs. Centralized Power Systems Frequency Control

    E-Print Network [OSTI]

    Dimarogonas, Dimos

    Distributed vs. Centralized Power Systems Frequency Control Martin Andreasson12 , Dimos V control of electrical power systems. We propose a distributed controller which retains the reference class of large- scale systems are electrical power systems, which employ automatic generation control

  13. Vibrational sum frequency study on biological interfaces

    E-Print Network [OSTI]

    Lim, Soon Mi

    2009-06-02T23:59:59.000Z

    , which is related to molecular orientation. Since the polarizabilities of molecules in bulk phase will be canceled out, a sum frequency signal can only be generated from interfaces where the inversion symmetry is broken. Because of its interfacial...

  14. Very-High-Frequency Resonant Boost Converters

    E-Print Network [OSTI]

    Perreault, David J.

    This paper presents a resonant boost topology suitable for very-high-frequency (VHF, 30-300 MHz) DC-DC power conversion. The proposed design features low device voltage stress, high efficiency over a wide load range, and ...

  15. Audio classification from time-frequency texture

    E-Print Network [OSTI]

    Slotine, Jean-Jacques E.

    Time-frequency representations of audio signals often resemble texture images. This paper derives a simple audio classification algorithm based on treating sound spectrograms as texture images. The algorithm is inspired ...

  16. Radio frequency dc-dc power conversion

    E-Print Network [OSTI]

    Rivas, Juan, 1976-

    2007-01-01T23:59:59.000Z

    THIS THESIS addresses the development of system architectures and circuit topologies for dc-dc power conversion at very high frequencies. The systems architectures that are developed are structured to overcome limitations ...

  17. Simulations of Vibrational Frequencies of Carbon

    E-Print Network [OSTI]

    Adler, Joan

    analytical model ­ Euler-Bernoulli theory Frequencies of the modes of the lateral vibration 8 fn ~ 1/L2 fn close to global or local buckling instabilities. 19 · The results of this study are relevant fo

  18. Multi-frequency cable vibration experiments

    E-Print Network [OSTI]

    Wiggins, Andrew (Andrew Dale)

    2005-01-01T23:59:59.000Z

    A series of Multi-Frequency cable vibration experiments at Reynolds number 7600 were carried out at the MIT Tow Tank using the Virtual Cable Towing Apparatus (VCTA). Motions observed in a Direct Numerical Simulation of a ...

  19. Agile optical frequency synthesis via parametric processes

    E-Print Network [OSTI]

    Kuo, Ping Piu

    2011-01-01T23:59:59.000Z

    frequency is not static, as in a CAST mixer. For example,Mixers 75   5.2 Demonstration and Performance Characterization . 79   5.2.1 Experimental Setup 79   5.2.2 Wavelength-Static

  20. Variable-speed wind power system with improved energy capture via multilevel conversion

    DOE Patents [OSTI]

    Erickson, Robert W.; Al-Naseem, Osama A.; Fingersh, Lee Jay

    2005-05-31T23:59:59.000Z

    A system and method for efficiently capturing electrical energy from a variable-speed generator are disclosed. The system includes a matrix converter using full-bridge, multilevel switch cells, in which semiconductor devices are clamped to a known constant DC voltage of a capacitor. The multilevel matrix converter is capable of generating multilevel voltage wave waveform of arbitrary magnitude and frequencies. The matrix converter can be controlled by using space vector modulation.

  1. Abstract--The induction motor is well known as the workhorse of industry. The development of variable speed

    E-Print Network [OSTI]

    Paderborn, Universität

    and followed by the future trend and needs in section VII. State of the Art of Induction Motor Control Joachim. In this paper the historical and recent developments and major milestones in control of induction motors--Induction motor control I. INTRODUCTION EFORE the invention of variable frequency voltage and current source

  2. Liquid crystal variable retarders in atomic scattering

    SciTech Connect (OSTI)

    Furst, J.E.; Yu, D.H.; Hayes, P.A.; DSouza, C.M.; Williams, J.F. [Physics Department, Centre for Atomic, Molecular, and Surface Physics, The University of Western Australia, Nedlands. WA. 6907 (Australia)] [Physics Department, Centre for Atomic, Molecular, and Surface Physics, The University of Western Australia, Nedlands. WA. 6907 (Australia)

    1996-11-01T23:59:59.000Z

    The applications of liquid crystal variable retarders in the production of spin-polarized electrons and in the determination of the polarization of optical radiation from atoms excited by polarized electrons are discussed. The advantages of using liquid crystal variable retarders in the measurement of Stokes parameters are insensitivity to the incident photon direction, large transmission diameter, variable retardation over large wavelength range without mechanical movement, and {ital in} {ital situ} calibration. {copyright} {ital 1996 American Institute of Physics.}

  3. Eccentric crank variable compression ratio mechanism

    DOE Patents [OSTI]

    Lawrence, Keith Edward (Kobe, JP); Moser, William Elliott (Peoria, IL); Roozenboom, Stephan Donald (Washington, IL); Knox, Kevin Jay (Peoria, IL)

    2008-05-13T23:59:59.000Z

    A variable compression ratio mechanism for an internal combustion engine that has an engine block and a crankshaft is disclosed. The variable compression ratio mechanism has a plurality of eccentric disks configured to support the crankshaft. Each of the plurality of eccentric disks has at least one cylindrical portion annularly surrounded by the engine block. The variable compression ratio mechanism also has at least one actuator configured to rotate the plurality of eccentric disks.

  4. Critical frequency in nuclear chiral rotation

    E-Print Network [OSTI]

    P. Olbratowski; J. Dobaczewski; J. Dudek

    2002-11-25T23:59:59.000Z

    Within the cranked Skyrme-Hartree-Fock approach the self-consistent solutions have been obtained for planar and chiral rotational bands in 132La. It turns out that the chiral band cannot exist below some critical rotational frequency which in the present case equals omega=0.6MeV. The appearance of the critical frequency is explained in terms of a simple classical model of two gyroscopes coupled to a triaxial rigid body.

  5. Multiple frequency printed slot and dipole antennas

    E-Print Network [OSTI]

    Kolsrud, Arild

    1997-01-01T23:59:59.000Z

    . Analysis. . D. Single Frequency Slot Antenna. , , , 32 . 41 E. Dual Frequency Slot Antenna. F. Chapter Summary. 48 Page CHAPTER IV PRINTED CPW-FED CPS DIPOLE. . . . . . . 53 A. Introduction. 53 B. Background. 54 C. Analysis. . D. Single... on the structure affects the performance by looking at the current distribution. Far-field radiation patterns of a structure can be calculated from the current distribution output data file. C. Chapter Summary Sonnet is mainly used for circuit structures, since...

  6. Extremely high frequency RF effects on electronics.

    SciTech Connect (OSTI)

    Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

    2012-01-01T23:59:59.000Z

    The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

  7. Climate dynamics and fluid mechanics: Natural variability and related uncertainties

    E-Print Network [OSTI]

    Michael Ghil; Mickaël D. Chekroun; Eric Simonnet

    2010-06-15T23:59:59.000Z

    The purpose of this review-and-research paper is twofold: (i) to review the role played in climate dynamics by fluid-dynamical models; and (ii) to contribute to the understanding and reduction of the uncertainties in future climate-change projections. To illustrate the first point, we focus on the large-scale, wind-driven flow of the mid-latitude oceans which contribute in a crucial way to Earth's climate, and to changes therein. We study the low-frequency variability (LFV) of the wind-driven, double-gyre circulation in mid-latitude ocean basins, via the bifurcation sequence that leads from steady states through periodic solutions and on to the chaotic, irregular flows documented in the observations. This sequence involves local, pitchfork and Hopf bifurcations, as well as global, homoclinic ones. The natural climate variability induced by the LFV of the ocean circulation is but one of the causes of uncertainties in climate projections. Another major cause of such uncertainties could reside in the structural instability in the topological sense, of the equations governing climate dynamics, including but not restricted to those of atmospheric and ocean dynamics. We propose a novel approach to understand, and possibly reduce, these uncertainties, based on the concepts and methods of random dynamical systems theory. As a very first step, we study the effect of noise on the topological classes of the Arnol'd family of circle maps, a paradigmatic model of frequency locking as occurring in the nonlinear interactions between the El Nino-Southern Oscillations (ENSO) and the seasonal cycle. It is shown that the maps' fine-grained resonant landscape is smoothed by the noise, thus permitting their coarse-grained classification. This result is consistent with stabilizing effects of stochastic parametrization obtained in modeling of ENSO phenomenon via some general circulation models.

  8. Variable-Period Undulators For Synchrotron Radiation

    DOE Patents [OSTI]

    Shenoy, Gopal (Naperville, IL); Lewellen, John (Plainfield, IL); Shu, Deming (Darien, IL); Vinokurov, Nikolai (Novosibirsk, RU)

    2005-02-22T23:59:59.000Z

    A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

  9. Variable Temperature UHV STM/AFM | EMSL

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

    Temperature UHV STMAFM The Omicron variable temperature ultra-high vacuum (UHV) scanning tunneling microscope (VTSTM) is designed to study the structure of both clean and...

  10. Optimization Online - Global Optimization via Slack Variables

    E-Print Network [OSTI]

    Isaac Siwale

    2014-08-01T23:59:59.000Z

    Aug 1, 2014 ... Citation: Siwale, I. (2014). Global optimization via slack variables. Technical Report No. RD-16-2013, London: Apex Research Ltd. Download: ...

  11. High-frequency homogenization of zero frequency stop band photonic and phononic crystals

    E-Print Network [OSTI]

    Antonakakis, Tryfon; Guenneau, Sebastien

    2013-01-01T23:59:59.000Z

    We present an accurate methodology for representing the physics of waves, for periodic structures, through effective properties for a replacement bulk medium: This is valid even for media with zero frequency stop-bands and where high frequency phenomena dominate. Since the work of Lord Rayleigh in 1892, low frequency (or quasi-static) behaviour has been neatly encapsulated in effective anisotropic media. However such classical homogenization theories break down in the high-frequency or stop band regime. Higher frequency phenomena are of significant importance in photonics (transverse magnetic waves propagating in infinite conducting parallel fibers), phononics (anti-plane shear waves propagating in isotropic elastic materials with inclusions), and platonics (flexural waves propagating in thin-elastic plates with holes). Fortunately, the recently proposed high-frequency homogenization (HFH) theory is only constrained by the knowledge of standing waves in order to asymptotically reconstruct dispersion curves an...

  12. ISM band to U-NII band frequency transverter and method of frequency transversion

    DOE Patents [OSTI]

    Stepp, Jeffrey David (Grandview, MO); Hensley, Dale (Grandview, MO)

    2006-04-04T23:59:59.000Z

    A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz-6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

  13. ISM band to U-NII band frequency transverter and method of frequency transversion

    SciTech Connect (OSTI)

    Stepp, Jeffrey David (Grandview, MO); Hensley, Dale (Grandview, MO)

    2006-09-12T23:59:59.000Z

    A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz 6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

  14. Envera Variable Compression Ratio Engine

    SciTech Connect (OSTI)

    Charles Mendler

    2011-03-15T23:59:59.000Z

    Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy has already demonstrated a degree of success, downsizing and fuel economy gains are currently limited. With new variable compression ratio technology however, the degree of engine downsizing and fuel economy improvement can be greatly increased. A small variable compression ratio (VCR) engine has the potential to return significantly higher vehicle fuel economy while also providing high power. Affordability and potential for near term commercialization are key attributes of the Envera VCR engine. VCR Technology To meet torque and power requirements, a smaller engine needs to do more work per stroke. This is typically accomplished by boosting the incoming charge with either a turbo or supercharger so that more energy is present in the cylinder per stroke to do the work. With current production engines the degree of engine boosting (which correlates to downsizing) is limited by detonation (combustion knock) at high boost levels. Additionally, the turbo or supercharger needs to be responsive and efficient while providing the needed boost. VCR technology eliminates the limitation of engine knock at high load levels by reducing compression ratio to {approx}9:1 (or whatever level is appropriate) when high boost pressures are needed. By reducing the compression ratio during high load demand periods there is increased volume in the cylinder at top dead center (TDC) which allows more charge (or energy) to be present in the cylinder without increasing the peak pressure. Cylinder pressure is thus kept below the level at which the engine would begin to knock. When loads on the engine are low the compression ratio can be raised (to as much as 18:1) providing high engine efficiency. It is important to recognize that for a well designed VCR engine cylinder pressure does not need to be higher than found in current production turbocharged engines. As such, there is no need for a stronger crankcase, bearings and other load bearing parts within the VCR engine. The Envera VCR mechanism uses an eccentric carrier approach to adjust engine compression ratio. The crankshaft main bearings are mounted in this eccentric carrier or 'crankshaft cradle' and pivoting the eccentric carrier 30 degrees adjusts compression ratio from 9:1 to 18:1. The eccentric carrier is made up of a casting that provides rigid support for the main bearings, and removable upper bearing caps. Oil feed to the main bearings transits through the bearing cap fastener sockets. The eccentric carrier design was chosen for its low cost and rigid support of the main bearings. A control shaft and connecting links are used to pivot the eccentric carrier. The control shaft mechanism features compression ratio lock-up at minimum and maximum compression ratio settings. The control shaft method of pivoting the eccentric carrier was selected due to its lock-up capability. The control shaft can be rotated by a hydraulic actuator or an electric motor. The engine shown in Figures 3 and 4 has a hydraulic actuator that was developed under the current program. In-line 4-cylinder engines are significantly less expensive than V engines because an entire cylinder head can be eliminated. The cost savings from eliminating cylinders and an entire cylinder head will notably offset the added cost of the VCR and supercharging. Replacing V6 and V8 engines with in-line VCR 4-cylinder engines will provide high fuel economy at low cost. Numerous enabling technologies exist which have the potential to increase engine efficiency. The greatest efficiency gains are realized when the right combination of advanced and new technologies are packaged together to provide the greatest gains at the least cost. Aggressive engine downsiz

  15. Effect on the condition of the metal in A K-300-3.5 turbine owing to multicycle fatigue from participation of a power generating unit in grid frequency and power regulation

    SciTech Connect (OSTI)

    Lebedeva, A. I.; Zorchenko, N. V.; Prudnikov, A. A.

    2011-09-15T23:59:59.000Z

    The effect on the condition of the rotor material owing to multicycle fatigue caused by variable stresses during participation of a power generating unit in grid frequency and power regulation is evaluated using the K-300-23.5 steam turbine as an example. It is shown that during normalized primary frequency regulation the safety factor is at least 50, while during automatic secondary regulation of frequency and power there is essentially no damage to the metal.

  16. RADIO FREQUENCY PHASE IN THE FEL SECTION OF A TBA

    E-Print Network [OSTI]

    Kuenning, R.W.

    2008-01-01T23:59:59.000Z

    Amplitude Control of the Radio Frequency Wave in the Two-Madison, WI, August 21-27, 1986 RADIO FREQUENCY PHASE IN THEAC03-76SF00098 LBL- 223Pl RADIO FREQUENCY PHASE IN THE FEL

  17. Radar network communication through sensing of frequency hopping

    DOE Patents [OSTI]

    Dowla, Farid; Nekoogar, Faranak

    2013-05-28T23:59:59.000Z

    In one embodiment, a radar communication system includes a plurality of radars having a communication range and being capable of operating at a sensing frequency and a reporting frequency, wherein the reporting frequency is different than the sensing frequency, each radar is adapted for operating at the sensing frequency until an event is detected, each radar in the plurality of radars has an identification/location frequency for reporting information different from the sensing frequency, a first radar of the radars which senses the event sends a reporting frequency corresponding to its identification/location frequency when the event is detected, and all other radars in the plurality of radars switch their reporting frequencies to match the reporting frequency of the first radar upon detecting the reporting frequency switch of a radar within the communication range. In another embodiment, a method is presented for communicating information in a radar system.

  18. ORIGINAL PAPER Fire frequency and tree canopy structure influence plant

    E-Print Network [OSTI]

    Minnesota, University of

    composition (Huston 1994). Ecological theory predicts important linkages between disturbance frequency frequencies and severities that minimize species losses due to competitive exclusion and direct disturbanceORIGINAL PAPER Fire frequency and tree canopy structure influence plant species diversity

  19. Nonresonant and Resonant Frequency-Selectable Induction-Heating Targets

    E-Print Network [OSTI]

    Rodriguez, John I.

    This paper examines a scheme for developing frequency-selectable induction-heating targets for stimulating temperature-sensitive polymer gels. The phrase “frequency selectable” implies that each target has a frequency at ...

  20. AC Loss Reduction in Filamentized YBCO Coated Conductors with Virtual Transverse Cross-cuts

    SciTech Connect (OSTI)

    Zhang, Yifei [ORNL; Duckworth, Robert C [ORNL; Ha, Tam T [ORNL; List III, Frederick Alyious [ORNL; Gouge, Michael J [ORNL; Chen, Y [SuperPower Incorporated, Schenectady, New York; X, Xiong, [SuperPower Incorporated, Schenectady, New York; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York

    2011-01-01T23:59:59.000Z

    While the performance of YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO)-based coated conductors under dc currents has improved significantly in recent years, filamentization is being investigated as a technique to reduce ac loss so that the 2nd generation (2G) high temperature superconducting (HTS) wires can also be utilized in various ac power applications such as cables, transformers and fault current limiters. Experimental studies have shown that simply filamentizing the superconducting layer is not effective enough to reduce ac loss because of incomplete flux penetration in between the filaments as the length of the tape increases. To introduce flux penetration in between the filaments more uniformly and further reduce the ac loss, virtual transverse cross-cuts were made in superconducting filaments of the coated conductors fabricated using the metal organic chemical vapor deposition (MOCVD) method. The virtual transverse cross-cuts were formed by making cross-cuts (17 - 120 {micro}m wide) on the IBAD (ion beam assisted deposition)-MgO templates using laser scribing followed by depositing the superconducting layer ({approx} 0.6 {micro}m thick). AC losses were measured and compared for filamentized conductors with and without the cross-cuts under applied peak ac fields up to 100 mT. The results were analyzed to evaluate the efficacy of filament decoupling and the feasibility of using this method to achieve ac loss reduction.

  1. Radio-frequency driven dipole-dipole interactions in spatially separated volumes

    E-Print Network [OSTI]

    Atreju Tauschinsky; C. S. E. van Ditzhuijzen; L. D. Noordam; H. B. van Linden van den Heuvell

    2008-10-14T23:59:59.000Z

    Radio-frequency (rf) fields in the MHz range are used to induce resonant energy transfer between cold Rydberg atoms in spatially separated volumes. After laser preparation of the Rydberg atoms, dipole-dipole coupling excites the 49s atoms in one cylinder to the 49p state while the 41d atoms in the second cylinder are transferred down to the 42p state. The energy exchanged between the atoms in this process is 33 GHz. An external rf-field brings this energy transfer into resonance. The strength of the interaction has been investigated as a function of amplitude (0-1 V/cm) and frequency (1-30 MHz) of the rf-field and as a function of a static field offset. Multi-photon transitions up to fifth order as well as selection rules prohibiting the process at certain fields have been observed. The width of the resonances has been reduced compared to earlier results by switching off external magnetic fields of the magneto-optical trap, making sub-MHz spectroscopy possible. All features are well reproduced by theoretical calculations taking the strong ac-Stark shift due to the rf-field into account.

  2. Analysis of core damage frequency: Peach Bottom, Unit 2 internal events appendices

    SciTech Connect (OSTI)

    Kolaczkowski, A.M.; Cramond, W.R.; Sype, T.T.; Maloney, K.J.; Wheeler, T.A.; Daniel, S.L. (Science Applications International Corp., Albuquerque, NM (USA); Sandia National Labs., Albuquerque, NM (USA))

    1989-08-01T23:59:59.000Z

    This document contains the appendices for the accident sequence analysis of internally initiated events for the Peach Bottom, Unit 2 Nuclear Power Plant. This is one of the five plant analyses conducted as part of the NUREG-1150 effort for the Nuclear Regulatory Commission. The work performed and described here is an extensive reanalysis of that published in October 1986 as NUREG/CR-4550, Volume 4. It addresses comments from numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved, and considerable effort was expended on an improved analysis of loss of offsite power. The content and detail of this report is directed toward PRA practitioners who need to know how the work was done and the details for use in further studies. The mean core damage frequency is 4.5E-6 with 5% and 95% uncertainty bounds of 3.5E-7 and 1.3E-5, respectively. Station blackout type accidents (loss of all ac power) contributed about 46% of the core damage frequency with Anticipated Transient Without Scram (ATWS) accidents contributing another 42%. The numerical results are driven by loss of offsite power, transients with the power conversion system initially available operator errors, and mechanical failure to scram. 13 refs., 345 figs., 171 tabs.

  3. Variable Speed Pumping for Level Control 

    E-Print Network [OSTI]

    Vasel, M.

    1982-01-01T23:59:59.000Z

    The purpose of this paper is to describe an application of variable speed pumping to level control of an industrial process. Topics include a comparison of the process using control valves with a variable speed system, an energy savings and cost...

  4. THE MULTI-USE STEINEL VARIABLE TEMPERATURE

    E-Print Network [OSTI]

    Kleinfeld, David

    THE MULTI-USE STEINEL VARIABLE TEMPERATURE ELECTRONICALLY CONTROLLED HEAT GUNTEMPERATURE RANGE 212 at the outlet nozzle will bum flesh. Do not tum on Heat Gun with hand in front of nozzle. DO NOT USE NEAR equipment Specifications Temperature Variable from 212" F to 1100° F Watts 1500W Weight 1.5 lbs. Supply

  5. THE MULTI-USE STEINEL VARIABLE TEMPERATURE

    E-Print Network [OSTI]

    Kleinfeld, David

    THE MULTI-USE STEINEL VARIABLE TEMPERATURE ELECTRONICALLY CONTROLLED HEAT GUNTEMPERATURE RANGE 212 at the outlet nozzle will bum flesh. Do not tum on Heat Gun with hand in front of nozzle. DO NOT USE NEAR equipment Specifications Temperature Variable from 212° F to 1100° F Watts 1500W Weight 1.5 lbs. Supply

  6. Solar Dynamics Observatory/ Extreme Ultraviolet Variability Experiment

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Solar Dynamics Observatory/ EVE Extreme Ultraviolet Variability Experiment Frequently Asked and model solar extreme ultraviolet irradiance variations due to solar flares, solar rotation, and solar and structure of the Sun. What is solar variability? Solar radiation varies on all time scales ranging from

  7. Boosting Search with Variable Elimination. ? Javier Larrosa

    E-Print Network [OSTI]

    Dechter, Rina

    Boosting Search with Variable Elimination. ? Javier Larrosa Dep. Llenguatges i Sistemes Inform#12ElimSearchS;k, a hybrid meta- algorithm that combines search and variable elimination. The param- eter S names from the constraint graph. We also provide experimental evidence that the hybrid algorithm can

  8. Boosting Search with Variable Elimination. ? Javier Larrosa

    E-Print Network [OSTI]

    Dechter, Rina

    Boosting Search with Variable Elimination. ? Javier Larrosa Dep. Llenguatges i Sistemes Inform of variables, reduces the search tree size. In this paper we introduce VarElimSearch(S;k), a hybrid meta the constraint graph. We also provide experimental evidence that the hybrid algorithm can outperform state

  9. Variable Speed Pumping for Level Control

    E-Print Network [OSTI]

    Vasel, M.

    1982-01-01T23:59:59.000Z

    The purpose of this paper is to describe an application of variable speed pumping to level control of an industrial process. Topics include a comparison of the process using control valves with a variable speed system, an energy savings and cost...

  10. High frequency inductive lamp and power oscillator

    DOE Patents [OSTI]

    MacLennan, Donald A. (Gaithersburg, MD); Dymond, Jr., Lauren E. (North Potomac, MD); Gitsevich, Aleksandr (Montgomery Village, MD); Grimm, William G. (Silver Spring, MD); Kipling, Kent (Gaithersburg, MD); Kirkpatrick, Douglas A. (Great Falls, VA); Ola, Samuel A. (Silver Spring, MD); Simpson, James E. (Gaithersburg, MD); Trimble, William C. (Columbia, MD); Tsai, Peter (Olney, MD); Turner, Brian P. (Damascus, MD)

    2001-01-01T23:59:59.000Z

    A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and I or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to adjust the driving frequency of the oscillator.

  11. High frequency inductive lamp and power oscillator

    DOE Patents [OSTI]

    MacLennan, Donald A. (Gaithersburg, MD); Turner, Brian P. (Damascus, MD); Dolan, James T. (Frederick, MD); Kirkpatrick, Douglas A. (Great Falls, VA); Leng, Yongzhang (Damascus, MD)

    2000-01-01T23:59:59.000Z

    A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and/or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

  12. Test plan for performance testing of the Eaton AC-3 electric vehicle

    SciTech Connect (OSTI)

    Crumley, R.L.; Heiselmann, H.W.

    1985-04-01T23:59:59.000Z

    An alternating current (ac) propulsion system for an electric vehicle has been developed and tested by the Eaton Corporation. The test bed vehicle is a modified 1981 Mercury Lynx. The test plan has been prepared specifically for the third modification to this test bed and identified as the Eaton AC-3. The scope of the EG and G testing at INEL to be done on the Eaton AC-3 will include coastdown and dynamometer tests but will not include environmental, on-road, or track testing. Coastdown testing will be performed in accordance with SAE J-1263 (SAE Recommended Practice for Road Load Measurement and Dynamometer Simulation Using Coastdown Techniques).

  13. Segmented superconducting tape having reduced AC losses and method of making

    DOE Patents [OSTI]

    Foltyn, Stephen R. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Arendt, Paul N. (Los Alamos, NM); Holesinger, Terry G. (Los Alamos, NM); Wang, Haiyan (Los Alamos, NM)

    2009-09-22T23:59:59.000Z

    A superconducting tape having reduced AC losses. The tape has a high temperature superconductor layer that is segmented. Disruptive strips, formed in one of the tape substrate, a buffer layer, and the superconducting layer create parallel discontinuities in the superconducting layer that separate the current-carrying elements of the superconducting layer into strips or filament-like structures. Segmentation of the current-carrying elements has the effect of reducing AC current losses. Methods of making such a superconducting tape and reducing AC losses in such tapes are also disclosed.

  14. EMTP modeling of CIGRE benchmark based HVDC transmission system operating with weak AC systems

    SciTech Connect (OSTI)

    Sood, V.K. [Hydro-Quebec, Varennes, Quebec (Canada); Khatri, V.; Jin, H. [Concordia Univ., Montreal, Quebec (Canada). Dept. of Electrical and Computer Engineering

    1995-12-31T23:59:59.000Z

    An EMTP based study of a CIGRE benchmark based HVDC system operating with weak ac systems is carried out. The modeled system provides a starting point for (a) educators teaching HVDC transmission courses and (b) for utility planners to develop their own low-cost dedicated digital simulators for training purposes. In this paper, modeling details of the ac-dc system, dc converters and control are presented. To validate the control schemes presented, the HVDC system is tested under ac-dc fault conditions. Results obtained from an EMTP-based study under these fault conditions are also presented in this paper.

  15. Dynamic performance of a STATCON at an HVDC inverter feeding a very weak AC system

    SciTech Connect (OSTI)

    Zhuang, Y.; Menzies, R.W. [Univ. of Manitoba, Winnipeg, Manitoba (Canada)] [Univ. of Manitoba, Winnipeg, Manitoba (Canada); Nayak, O.B. [HVDC Research Centre, Winnipeg, Manitoba (Canada)] [HVDC Research Centre, Winnipeg, Manitoba (Canada); Turanli, H.M. [Manitoba Hydro, Winnipeg, Manitoba (Canada)] [Manitoba Hydro, Winnipeg, Manitoba (Canada)

    1996-04-01T23:59:59.000Z

    This paper investigates the dynamic performance of the advanced static var compensator or STATCON at a high voltage direct current (HVDC) converter terminal where the ac system has a very low short circuit ratio (SCR). The STATCON is based on a nine-level GTO thyristor inverter. The studies include operating characteristics of the STATCON under various ac and dc disturbances. The simulation results are compared with other types of reactive power compensation options available for such applications. It is shown that the STATCON has clear advantages over the other compensators, in areas such as; fault response time, voltage support ability, and dc recovery, while operating with very weak ac systems.

  16. Integration of Full Tensor Gravity and ZTEM Passive Low Frequency...

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

    and ZTEM Passive Low Frequency EM Instruments for Simultaneous Data Acquisition Integration of Full Tensor Gravity and ZTEM Passive Low Frequency EM Instruments for...

  17. Microwave (MW) and Radio Frequency (RF) as Enabling Technologies...

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

    Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced Manufacturing Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced...

  18. Advanced Radio Frequency-Based Sensors for Monitoring Diesel...

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

    Radio Frequency-Based Sensors for Monitoring Diesel Particulate Filter Loading and Regeneration Advanced Radio Frequency-Based Sensors for Monitoring Diesel Particulate Filter...

  19. Radio Frequency Diesel Particulate Filter Sensor Reduces Fuel...

    Office of Environmental Management (EM)

    Radio Frequency Diesel Particulate Filter Sensor Reduces Fuel Consumption, Wins R&D 100 Award Radio Frequency Diesel Particulate Filter Sensor Reduces Fuel Consumption, Wins R&D...

  20. EA-1631: Beacon Power Corporation Frequency Regulation Facility...

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

    1: Beacon Power Corporation Frequency Regulation Facility in Stephentown, NY EA-1631: Beacon Power Corporation Frequency Regulation Facility in Stephentown, NY February 2, 2009...

  1. Graphene-coated coupling coil for AC resistance reduction

    DOE Patents [OSTI]

    Miller, John M

    2014-03-04T23:59:59.000Z

    At least one graphene layer is formed to laterally surround a tube so that the basal plane of each graphene layer is tangential to the local surface of the tube on which the graphene layer is formed. An electrically conductive path is provided around the tube for providing high conductivity electrical path provided by the basal plane of each graphene layer. The high conductivity path can be employed for high frequency applications such as coupling coils for wireless power transmission to overcome skin depth effects and proximity effects prevalent in high frequency alternating current paths.

  2. Frequency dependence of the Chiral Vortical Effect

    E-Print Network [OSTI]

    Karl Landsteiner; Eugenio Megias; Francisco Peña Benítez

    2014-09-18T23:59:59.000Z

    We study the frequency dependence of all the chiral vortical and magnetic conductivities for a relativistic gas of free chiral fermions and for a strongly coupled conformal field theory with holographic dual in four dimensions. Both systems have gauge and gravitational anomalies, and we compute their contribution to the conductivities. The chiral vortical conductivities and the chiral magnetic conductivity in the energy current show a frequency dependence in the form of a delta centered at zero frequency. This highly discontinuous behavior is a natural consequence of the Ward identities that include the energy momentum tensor. We discuss the physical interpretation of this result and its possible implications for the quark gluon plasma as created in heavy ion collisions. In the Appendix we discuss why the chiral magnetic effect seems to vanish in the consistent current for a particular implementation of the axial chemical potential.

  3. Rapid and correlated variability of blazar S5 0716+71 from radio- to sub-mm bands

    E-Print Network [OSTI]

    L. Fuhrmann; T. P. Krichbaum; A. Witzel; I. Agudo; S. Britzen; S. Bernhart; V. Impellizzeri; A. Kraus; E. Angelakis; U. Bach; K. Gabányi; J. A. Zensus

    2006-11-13T23:59:59.000Z

    The BL Lac object S5 0716+71 was target of a coordinated and global multi-frequency campaign to search for rapid and correlated variability and signatures of the inverse-Compton catastrophe. Here we present first results obtained from a combined analysis of the cm- to sub-mm observations over a period of seven days aiming at a detailed study of the intra- to inter-day variability characteristics and to obtain constraints on the variability brightness temperatures and Doppler factors comparing the radio data with the high energy emission recorded by INTEGRAL. A more detailed description of the whole cm- to sub-mm observations and our analysis/results will be presented in a forthcoming paper. Our analysis reveals the source to be in a particular short-term variability phase when compared to the past with a correlated >~4 day time scale amplitude increase of up to 35%, which is systematically more pronounced towards higher frequencies. The obtained frequency dependent variability amplitudes and time lags contradict expectations from interstellar scintillation and strongly suggest a source intrinsic origin of this inter-day variability. A 7-day spectral evolution study indicate time-variable synchrotron self-absorption and expansion of the emission region, consistent with standard models. Assuming relativistic boosting, our different estimates of the Doppler factor yield robust lower limits of D_var,IC > 5-22 using the inverse-Compton limit and D_var,eq > 8-33 using the equipartition argument. Although high, these values are in good agreement with Doppler factors obtained from recent VLBI studies and from the inverse-Compton Doppler factors D_IC > 14-16 derived with the X-ray emission seen by INTEGRAL at 3-200 keV.

  4. Seismic isolation systems with distinct multiple frequencies

    DOE Patents [OSTI]

    Wu, Ting-shu (Downers Grove, IL); Seidensticker, Ralph W. (Wheaton, IL)

    1990-01-01T23:59:59.000Z

    A method and apparatus for isolating a building or other structure from smic vibratory motion which provides increased assurance that large horizontal motion of the structure will not occur than is provided by other isolation systems. Increased assurance that large horizontal motion will not occur is achieved by providing for change of the natural frequency of the support and structure system in response to displacement of the structure beyond a predetermined value. The natural frequency of the support and structure system may be achieved by providing for engaging and disengaging of the structure and some supporting members in response to motion of the supported structure.

  5. Frequency Synthesis in Wireless and Wireline Systems

    E-Print Network [OSTI]

    Turker, Didem 1981-

    2010-12-06T23:59:59.000Z

    low cost and long battery life. IEEE 802.15.4 / ZigBee is defined over three frequency bands [6]. It has one channel in the European 868MHz band, 10 channels in the 915MHz ISM band and 16 channels in the 2.4GHz ISM band. In this work, we will focus... on the 2.4GHz ISM band. In this band, ZigBee has 250kbps data rate, offset quadrature phase shift keying (OQPSK) modulation and 5MHz channel spacing [6], [9]. B. Frequency Synthesis for a ZigBee Transceiver Since a ZigBee network could have thousands...

  6. Computing Instantaneous Frequency by normalizing Hilbert Transform

    DOE Patents [OSTI]

    Huang, Norden E.

    2005-05-31T23:59:59.000Z

    This invention presents Normalized Amplitude Hilbert Transform (NAHT) and Normalized Hilbert Transform(NHT), both of which are new methods for computing Instantaneous Frequency. This method is designed specifically to circumvent the limitation set by the Bedorsian and Nuttal Theorems, and to provide a sharp local measure of error when the quadrature and the Hilbert Transform do not agree. Motivation for this method is that straightforward application of the Hilbert Transform followed by taking the derivative of the phase-angle as the Instantaneous Frequency (IF) leads to a common mistake made up to this date. In order to make the Hilbert Transform method work, the data has to obey certain restrictions.

  7. Frequency Scaling from Copper to SC Niobium

    E-Print Network [OSTI]

    D'Elia, A

    2010-01-01T23:59:59.000Z

    The linac of HIE-ISOLDE Project is based on two gap independently phased Quarter Wave Resonators (QWRs). The cavities are made in bulk Copper and subsequently Niobium sputtered. The working frequency in superconducting mode of operation is 101.28MHz at 4.5K. The purpose of this paper is to properly evaluate the scaled frequency of the Copper cavity at room temperature in air, in order to guide all the necessary steps in the production phase before going to the cryostat.

  8. TIME-FREQUENCY-PHASE TRACKING APPROACH : APPLICATION TO UNDERWATER SIGNALS IN A PASSIVE CONTEXT

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of Montenegro, Podgorica ­ MONTENEGRO E-mail : srdjan@cg.ac.yu ABSTRACT One of the most challenging applications

  9. Dimensional variability of production steel castings

    SciTech Connect (OSTI)

    Peters, F.E.; Risteu, J.W.; Vaupel, W.G.; DeMeter, E.C.; Voigt, R.C.

    1994-12-31T23:59:59.000Z

    Work is ongoing to characterize the dimensional variability of steel casting features. Data are being collected from castings produced at representative Steel Founders` Society of America foundries. Initial results based on more than 12,500 production casting feature measurements are presented for carbon and low alloy steel castings produced in green sand, no-bake, and shell molds. A comprehensive database of casting, pattern, and feature variables has been developed so that the influence of the variables on dimensional variability can be determined. Measurement system analysis is conducted to insure that large measurement error is not reported as dimensional variability. Results indicate that the dimensional variability of production casting features is less than indicated in current US (SFSA) and international (ISO) standards. Feature length, casting weight, parting line and molding process all strongly influence dimensional variability. Corresponding pattern measurements indicate that the actual shrinkage amount for casting features varies considerably. This variation in shrinkage will strongly influence the ability of the foundry to satisfy customer dimensional requirements.

  10. Suppression of chaos at slow variables by rapidly mixing fast dynamics through linear energy-preserving coupling

    E-Print Network [OSTI]

    Rafail V. Abramov

    2011-08-14T23:59:59.000Z

    Chaotic multiscale dynamical systems are common in many areas of science, one of the examples being the interaction of the low-frequency dynamics in the atmosphere with the fast turbulent weather dynamics. One of the key questions about chaotic multiscale systems is how the fast dynamics affects chaos at the slow variables, and, therefore, impacts uncertainty and predictability of the slow dynamics. Here we demonstrate that the linear slow-fast coupling with the total energy conservation property promotes the suppression of chaos at the slow variables through the rapid mixing at the fast variables, both theoretically and through numerical simulations. A suitable mathematical framework is developed, connecting the slow dynamics on the tangent subspaces to the infinite-time linear response of the mean state to a constant external forcing at the fast variables. Additionally, it is shown that the uncoupled dynamics for the slow variables may remain chaotic while the complete multiscale system loses chaos and becomes completely predictable at the slow variables through increasing chaos and turbulence at the fast variables. This result contradicts the common sense intuition, where, naturally, one would think that coupling a slow weakly chaotic system with another much faster and much stronger mixing system would result in general increase of chaos at the slow variables.

  11. Analysis of two basic variables of timeout 

    E-Print Network [OSTI]

    Zella, William Francis

    1974-01-01T23:59:59.000Z

    ANALYSIS OF TWO BASIC VARIABLES OF TIMEOUT A Thesis WILLIAM FRANCIS ZELLA Submitted to the Graduate College of Texas AaM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August l974 Major Subjects... Psychology ANALYSI QF TWQ BASIC VARIABLES CF TINEQU '. A Thesis V/ILLIAM FRANCIS ZELLA Approved as to s+yle and content bye Chairman of Commi, ee Head of De artment) (Membe Member) Member ABSTRACT Analysis of Two Basic Variables of Timeout. (August...

  12. Mission Support Contract Attachment J.10 Contract No. DE-AC06...

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

    J.10 Contract No. DE-AC06-09RL14728 Modification 369 Table Of Contents J.10-1 SERVICE CONTRACT ACT: WAGE DETERMINATION ... 2 J.10-2 DAVIS...

  13. Rotating electrical machines - Part 22: AC generators for reciprocating internal combustion (RIC) engine driven generating sets

    E-Print Network [OSTI]

    International Electrotechnical Commission. Geneva

    1996-01-01T23:59:59.000Z

    Establishes the principal characteristics of a.c. generators under the control of their voltage regulators when used for reciprocating internal combustion engine driven generating sets. Supplements the requirements given in IEC 60034-1.

  14. AEP (Central and SWEPCO)- Coolsaver A/C Tune Up or Replacement

    Broader source: Energy.gov [DOE]

    Participating customers are eligible to receive a $75 coupon for use toward A/C and heat pump efficiency services performed as a result of the program’s tune-up analysis, contractors are eligible...

  15. Solar Electric Grid Integration- Advanced Concepts (SEGIS-AC) Funding Opportunity

    Broader source: Energy.gov [DOE]

    Through the Solar Electric Grid Integration – Advanced Concepts (SEGIS-AC) program, DOE is funding solar projects that are targeting ways to develop power electronics and build smarter, more...

  16. AC losses in type-II superconductors induced by nonuniform fluctuations of external magnetic field

    E-Print Network [OSTI]

    as the economic gains of implementation of type-II superconductors in power transmission lines, current leads amplitude. The results can be used to estimate the AC losses in flywheels, electric motors, magnetic shields

  17. acs_NL_nl-2011-03332e 1..8

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

    | Nano Lett. 2011, 11, 5071-5078 LETTER pubs.acs.orgNanoLett Hierarchically Porous Graphene as a LithiumAir Battery Electrode Jie Xiao,* , Donghai Mei, Xiaolin Li, ...

  18. Docket No. EERE-2012-BT-TP-0046; RIN 1904-AC52 Ex partecommunication...

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

    & Publications Docket No. EERE-2012-BT-TP-0046; RIN 1904-AC52 Docket No. EERE-2012-BT-TP-0046 Ex Parte Communication Ex Parte Memorandum on Set Top Boxes and Network Equipment...

  19. System and Battery Charge Control for PV-Powered AC Lighting Systems

    SciTech Connect (OSTI)

    Kern, G.

    1999-04-01T23:59:59.000Z

    This report reviews a number of issues specific to stand-alone AC lighting systems. A review of AC lighting technology is presented, which discusses the advantages and disadvantages of various lamps. The best lamps for small lighting systems are compact fluorescent. The best lamps for intermediate-size systems are high- or low-pressure sodium. Specifications for battery charging and load control are provided with the goal of achieving lamp lifetimes on the order of 16,000 to 24,000 hours and battery lifetimes of 4 to 5 years. A rough estimate of the potential domestic and global markets for stand-alone AC lighting systems is presented. DC current injection tests were performed on high-pressure sodium lamps and the test results are presented. Finally, a prototype system was designed and a prototype system controller (with battery charger and DC/AC inverter) was developed and built.

  20. Alameda-Contra Costa Transit District (AC Transit) Fuel Cell Transit Buses: Preliminary Evaluation Results

    SciTech Connect (OSTI)

    Chandler, K.; Eudy, L.

    2007-03-01T23:59:59.000Z

    This report provides an evaluation of three prototype fuel cell-powered transit buses operating at AC Transit in Oakland, California, and six baseline diesel buses similar in design to the fuel cell buses.