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Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
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1

Variable frequency microwave furnace system  

DOE Patents (OSTI)

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.

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

1994-06-14T23:59:59.000Z

2

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

DOE Patents (OSTI)

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.

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

1987-07-30T23:59:59.000Z

3

System for transmitting low frequency analog signals over AC power lines  

DOE Patents (OSTI)

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 in 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.

Baker, Steven P. (Powell, TN); Durall, Robert L. (Lenoir City, TN); Haynes, Howard D. (Knoxville, TN)

1989-01-01T23:59:59.000Z

4

Information Theory and Predictability for Low-Frequency Variability  

Science Conference Proceedings (OSTI)

A predictability framework, based on relative entropy, is applied here to low-frequency variability in a standard T21 barotropic model on the sphere with realistic orography. Two types of realistic climatology, corresponding to different heights ...

Rafail Abramov; Andrew Majda; Richard Kleeman

2005-01-01T23:59:59.000Z

5

Homoclinic Dynamics: A Scenario for Atmospheric Ultralow-Frequency Variability  

Science Conference Proceedings (OSTI)

In this paper, a link will be established between atmospheric ultralow-frequency variability (ULFV) and the occurrence of homoclinic dynamics in models of large-scale atmospheric flow. It is known that uncoupled atmosphere models possess ...

Daan T. Crommelin

2002-05-01T23:59:59.000Z

6

Low-Frequency Variability in the Wind-Driven Circulation  

Science Conference Proceedings (OSTI)

The origins of low-frequency variability in a simple homogenous ocean model, forced by a double gyre Ekman suction, are examined numerically. It is found that irregular, large amplitude vacillations in the structure of the circulation typify the ...

S. P. Meacham

2000-02-01T23:59:59.000Z

7

AC Resonant charger with charge rate unrelated to primary power frequency  

DOE Patents (OSTI)

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.

Watson, Harold (Torrance, CA)

1982-01-01T23:59:59.000Z

8

Eddy-Induced Instability for Low-Frequency Variability  

Science Conference Proceedings (OSTI)

Synoptic eddy–mean flow interaction has been recognized as one of the key sources for extratropical low-frequency variability. In this paper, the underlying dynamics of this interaction are examined from the perspective of a synoptic eddy-induced ...

F-F. Jin

2010-06-01T23:59:59.000Z

9

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

E-Print Network (OSTI)

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 and the motor is connected to it through an umbilical cable, and VFD and the motor are installed closely and they are connected to the system through an umbilical cable. In this thesis, the pros and cons of each configuration are mentioned, but the focus is on the system with a VFD controlled motor through a long umbilical cable. A 36-pulse VFD is studied. Since multilevel VFDs have high frequency harmonics, high frequency modeling of the umbilical cable is used, and skin effect is also taken into consideration in the cable. The effect of the interactions between the umbilical cable and high frequency harmonics on the motor terminal voltage is explored.

Ozkentli, Esra

2012-08-01T23:59:59.000Z

10

Variable speed constant frequency constant voltage alternator. Annual report  

DOE Green Energy (OSTI)

A test alternator is operated with digital control of its output frequency for variable shaft speed. The machine is a two-pole alternator with power removed through slip rings. The output frequency of the alternator is controlled by rotating the field by stepping through sixteen coils around the rotor. Usually four coils are active at one time. The rotating field in the stationary coils of the stator is controlled by microcircuits. The control circuits are constructed with available low-cost, low-power integrated circuits (ICs). The test results from the first test alternator indicate the feasibility of using this type of alternator to convert available wind power directly to usable 60 hertz power.

Grannemann, W.W.; Yang, C.E.; Seo, P.H.

1980-07-01T23:59:59.000Z

11

The ACS LCID Project: Variable Stars in Tucana and LGS3  

E-Print Network (OSTI)

We present preliminary results concerning the search for short-period variable stars in Tucana and LGS3 based on very deep HST/ACS imaging. In the one chip per galaxy we studied so far, a total of 230 and 80 candidates variables were found, respectively. For Tucana, we identified 134 of them as RR Lyrae stars (RRL) pulsating in the fundamental mode (RRab), 51 in the first-overtone mode (RRc), and 37 in both modes simultaneoulsy (RRd), as well as four candidate anomalous Cepheids (AC). In the case of LGS3, we found 45 RRab and 5 RRc, plus three candidates RRd and five candidate AC. The metallicities obtained from the mean period of the RRab are [Fe/H]_{Tuc}=-1.7 and [Fe/H]_{LGS3}=-1.8.

Bernard, Edouard J

2007-01-01T23:59:59.000Z

12

The ACS LCID Project: Variable Stars in Tucana and LGS3  

E-Print Network (OSTI)

We present preliminary results concerning the search for short-period variable stars in Tucana and LGS3 based on very deep HST/ACS imaging. In the one chip per galaxy we studied so far, a total of 230 and 80 candidates variables were found, respectively. For Tucana, we identified 134 of them as RR Lyrae stars (RRL) pulsating in the fundamental mode (RRab), 51 in the first-overtone mode (RRc), and 37 in both modes simultaneoulsy (RRd), as well as four candidate anomalous Cepheids (AC). In the case of LGS3, we found 45 RRab and 5 RRc, plus three candidates RRd and five candidate AC. The metallicities obtained from the mean period of the RRab are [Fe/H]_{Tuc}=-1.7 and [Fe/H]_{LGS3}=-1.8.

Edouard J. Bernard

2007-05-18T23:59:59.000Z

13

Variable Frequency Drives: Energy Savings and Impact on Motor Performance  

E-Print Network (OSTI)

Variable frequency drives (VFDs) have found widespread application in recent years. VFDs are valued for their potential to save energy and improve processes. Reliability has improved significantly, but there are still pitfalls to be addressed in properly applying VFDs. The benefits and pitfalls in applying VFDs that will be addressed by this paper include- Benefits: Energy Savings, Improved Process Control, “Soft Start” Reduced Mechanical Stress, Improved Electrical System Power Factor, 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.

Petro, D.

1993-03-01T23:59:59.000Z

14

ESP-The Electrical submersible pump. Part 7. Applying variable frequency drives to ESPs  

SciTech Connect

To keep pace with technology, the oil industry has begun using variable frequency drives on electrical submersible pumps. Applying variable frequency drives on ESPs began seriously in 1977. In March 1983, there were approximately 350 variable frequency drives successfully operating on electrical submersible pumps throughout the world. Three types of variable frequency drives available today are the current source inverter, the pulse width modulation, and the variable voltage source inverter. As all three types have good points and bad, a short discussion of each type is essential to understand why the variable voltage inverter is used most often in oil field applications and why it has been a success. A current source inverter typically uses a phasecontrolled rectifier to generate variable DC current. The phase-controlled rectifier produces the required current which is subsequently filtered by a DC link reactor. The inverter then produces the desired variable frequency current and the motor voltage varies with load.

Watson, A.J.

1983-11-15T23:59:59.000Z

15

Jet Jumping: Low-Frequency Variability in the Southern Ocean  

Science Conference Proceedings (OSTI)

The authors study intrinsic variability in the position of jets in a ?-plane channel ocean with simple topography using a quasigeostrophic numerical model. This study links the variability in jet position with abyssal anticyclones that form as a ...

Christopher C. Chapman; Andrew McC. Hogg

2013-05-01T23:59:59.000Z

16

Offshore operations report. ESP - the electrical submersible pump. Part 7. Applying variable frequency drives to esps  

SciTech Connect

The oil industry has begun using variable frequency drives on electric submersible pumps. In March 1983, there were approximately 350 variable frequency drives successfully operating on electrical submersible pumps throughout the world. Three types of variable frequency drives available are the current source inverter, the pulse width modulation, and the variable voltage source inverter. A short discussion of each type is given to explain why the variable voltage inverter is used most often in oil field applications and why it has been a success.

Watson, A.J.

1983-11-15T23:59:59.000Z

17

Simulation of North Atlantic Low-Frequency SST Variability  

Science Conference Proceedings (OSTI)

The role of atmospheric circulation anomalies in generating midlatitude sea surface temperature (SST) variability is investigated by means of ocean general circulation model (OGCM) experiments, in which observed winds are prescribed during the ...

Ute Luksch

1996-09-01T23:59:59.000Z

18

A Stabilization of Frequency Oscillations in a Parallel AC-DC Interconnected Power System via an HVDC Link  

E-Print Network (OSTI)

This paper presents a new application of High Voltage Direct Current (HVDC) link to stabilization of frequency oscillations in a parallel AC-DC interconnected power system. When an interconnected AC power system is subjected to a large load with rapid change, system frequency may be considerably disturbed and becomes oscillatory. By utilizing the system interconnections as the control channels of HVDC link, the tie-line power modulation of HVDC link through interconnections is applicable for stabilizing the frequency oscillations of AC systems. In the design of power modulation controller, the technique of overlapping decompositions and the eigenvalue assignment are applied to establish the state feedback control scheme. To evaluate control effects, a linearized model of a parallel AC-DC interconnected system, including a power modulation controller of HVDC link, is investigated by simulation study. Simulation results show that the proposed controller is not only effective in damping out frequency oscillations, but also capable of alleviating the transient frequency swing caused by a large load disturbance.

Issarachai Ngamroo

2002-01-01T23:59:59.000Z

19

Mechanisms of Monsoon Low-Frequency Variability: Surface Hydrological Effects  

Science Conference Proceedings (OSTI)

Observations indicate that monsoon systems are characterized by orderly large-scale and low-frequency variations. With a time scale of two weeks and sometimes longer, regions of ascending motion are observed to form to the north of the equator ...

Peter J. Webster

1983-09-01T23:59:59.000Z

20

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

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.

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

1994-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Empirical Mode Reduction in a Model of Extratropical Low-Frequency Variability  

Science Conference Proceedings (OSTI)

This paper constructs and analyzes a reduced nonlinear stochastic model of extratropical low-frequency variability. To do so, it applies multilevel quadratic regression to the output of a long simulation of a global baroclinic, quasigeostrophic, ...

D. Kondrashov; S. Kravtsov; M. Ghil

2006-07-01T23:59:59.000Z

22

Low-Frequency Variability in a Baroclinic ? Channel with Land–Sea Contrast  

Science Conference Proceedings (OSTI)

Atmospheric low-frequency variability (LFV) is studied in a two-layer quasigeostrophic model. The model geometry is a periodic ? channel with flat bottom and zonally inhomogeneous thermal forcing. As a result of the idealized land–sea contrast, ...

S. Kravtsov; A. W. Robertson; M. Ghil

2003-09-01T23:59:59.000Z

23

Low-Frequency Variability and Remote Forcing of Gap Winds over the East Pacific Warm Pool  

Science Conference Proceedings (OSTI)

The low-frequency variability of gap winds at the Isthmuses of Tehuantepec and Papagayo is investigated using a 17-yr wind stress dataset merging the remotely sensed observations of Special Sensor Microwave Imager (SSM/I) and Quick Scatterometer (...

Kristopher B. Karnauskas; Antonio J. Busalacchi; Raghu Murtugudde

2008-10-01T23:59:59.000Z

24

Stationary Wave Accumulation and the Generation of Low-Frequency Variability on Zonally Varying Flows  

Science Conference Proceedings (OSTI)

A potent mechanism for the generation of low-frequency atmospheric variability on vortex basic states consisting of a single potential vorticity jump, or contour, separating two regions of uniform equivalent barotropic potential vorticity is ...

K. L. Swanson

2000-07-01T23:59:59.000Z

25

Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System  

Science Conference Proceedings (OSTI)

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.

Randy Peden; Sanjiv Shah

2005-07-26T23:59:59.000Z

26

The ACS LCID Project. II. Faint Variable Stars in the Isolated Dwarf Irregular Galaxy IC1613  

E-Print Network (OSTI)

(Abridged) We present the results of a new search for variable stars in the Local Group (LG) isolated dwarf galaxy IC1613, based on 24 orbits of F475W and F814W photometry from the ACS camera onboard the HST. We detected 259 candidate variables in this field, of which only 13 (all of them bright Cepheids) were previously known. Out of the confirmed variables, we found 90 RR Lyrae stars, 49 classical Cepheids (including 36 new discoveries), and 38 eclipsing binary stars for which we could determine a period. The RR Lyrae include 61 fundamental (RRab) and 24 first-overtone (RRc) pulsators, and 5 pulsating in both modes simultaneously (RRd). As for the majority of LG dwarfs, the mean periods of the RRab and RRc (0.611 and 0.334 day, respectively) as well as the fraction of overtone pulsators (f_c=0.28) place this galaxy in the intermediate regime between the Oosterhoff types. From their position on the period-luminosity diagram and light-curve morphology, we can unambiguously classify 25 and 14 Cepheids as funda...

Bernard, Edouard J; Gallart, Carme; Aparicio, Antonio; Cassisi, Santi; Drozdovsky, Igor; Hidalgo, Sebastian L; Skillman, Evan D; Stetson, Peter B

2010-01-01T23:59:59.000Z

27

Geographical Variations of the Influence of Low-Frequency Variability on Lower-Tropospheric Extreme Westerly Wind Events  

Science Conference Proceedings (OSTI)

A conceptual framework is developed for quantifying the relationship between low-frequency variability and extreme events. In this framework, variability is decomposed into low-frequency and synoptic components using complementary 10-day low-pass ...

Jeffrey H. Yin; Grant W. Branstator

2008-09-01T23:59:59.000Z

28

Low-Frequency Variability in the Arctic Atmosphere, Sea Ice, and Upper-Ocean Climate System  

Science Conference Proceedings (OSTI)

The low-frequency natural variability of the arctic climate system is modeled using a single-column, energy balance model of the atmosphere. sea ice, and upper-ocean system. Variability in the system is induced by forcing with realistic, random ...

C. M. Bitz; D. S. Battisti; R. E. Moritz; J. A. Beesley

1996-02-01T23:59:59.000Z

29

ACCELERATED AGING STUDY OF MACHINE WINDING INSULATION UNDER AC AND HIGH FREQUENCY PULSE VOLTAGE APPLICATION.  

E-Print Network (OSTI)

?? It is common practice to perform accelerated aging with 60 Hz ac to determine the lifetime characteristics of insulation used in the machine. Comparable… (more)

Chalise, Sajal Raj

2010-01-01T23:59:59.000Z

30

Forecast Skill and Low-Frequency Variability in NMC DERF90 Experiments  

Science Conference Proceedings (OSTI)

A series of 90-day integrations by a low-resolution version (T40) of the National Meteorological Center's global spectral model was analyzed for its performance as well as its low-frequency variability behavior. In particular, 5-day mean 500-mb ...

Wilbur Y. Chen; Huug M. van den Dool

1995-08-01T23:59:59.000Z

31

Low-Frequency Pycnocline Depth Variability at Ocean Weather Station P in the Northeast Pacific  

Science Conference Proceedings (OSTI)

Low-frequency variability of the depth of the main pycnocline at Ocean Weather Station P and over the northeast Pacific is examined in terms of the one-dimensional response to local Ekman pumping according to the Hasselmann stochastic climate ...

Patrick F. Cummins; Gary S. E. Lagerloef

2002-11-01T23:59:59.000Z

32

Low-Frequency Variability in the Northern Hemisphere Winter: Geographical Distribution, Structure and Time-Scale Dependence  

Science Conference Proceedings (OSTI)

Low-frequency variability in wintertime 500 mb height is examined, with emphasis on its structure, geographical distribution, and frequency dependence. A 39-year record of 500 mb geopotential height fields from the NMC analyses is time filtered ...

Yochanan Kushnir; John M. Wallace

1989-10-01T23:59:59.000Z

33

The Role of Pacific Climate on Low-Frequency Hydroclimatic Variability and Predictability in Southern Alberta, Canada  

Science Conference Proceedings (OSTI)

Wavelet and rank correlation analysis were used to identify the links between primary Pacific climate variability modes and low-frequency hydroclimatic variability in the South Saskatchewan River basin (SSRB) of southern Alberta. The April–...

Adam K. Gobena; Thian Y. Gan

2009-12-01T23:59:59.000Z

34

Model of variable speed constant frequency double fed wind power generation system and analysis of its operating performance  

Science Conference Proceedings (OSTI)

Structure of variable speed constant frequency double fed wind power generation system (WPGS) was analyzed, and its model was established. Maximum power point tracking (MPPT) control, constant power control and vector control for WPGS were discussed. ... Keywords: operating performance, variable speed constant frequency, vector control, wind power generation system

Pan Tinglong; Ji Zhicheng

2009-06-01T23:59:59.000Z

35

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

Science Conference Proceedings (OSTI)

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.

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

1995-03-01T23:59:59.000Z

36

Impact of Atmospheric Intraseasonal Variability in the Indian Ocean: Low-Frequency Rectification in Equatorial Surface Current and Transport  

Science Conference Proceedings (OSTI)

An ocean general circulation model (OGCM) is used to investigate the low-frequency (period longer than 90 days) rectification of atmospheric intraseasonal variability (10–90-day periods) in zonal surface current and transport of the equatorial ...

Weiqing Han; Peter Webster; Roger Lukas; Peter Hacker; Aixue Hu

2004-06-01T23:59:59.000Z

37

Phenomenology of the Low-Frequency Variability in a Reduced-Gravity, Quasigeostrophic Double-Gyre Model  

Science Conference Proceedings (OSTI)

The low-frequency variability of the oceanic wind-driven circulation is investigated by use of a reduced-gravity, quasigeostrophic model with slight variations on the classic double-gyre wind forcing. Approximately 30 eddy-resolving simulations ...

John D. McCalpin; Dale B. Haidvogel

1996-05-01T23:59:59.000Z

38

Structure of Oceanic and Atmospheric Low-Frequency Variability over the Tropical Pacific and Indian Oceans. Part I: COADS Observations  

Science Conference Proceedings (OSTI)

The recurrent modes of combined oceanic and atmospheric low-frequency variability over the tropical Pacific and Indian oceans are calculated to provide quantitatively and structurally well-defined targets for simulation/prediction studies of ...

Sumant Nigam; Horng-Syi Shen

1993-04-01T23:59:59.000Z

39

Observations and EOF Analysis of Low-Frequency Variability in the Western Part of the Gulf Stream Recirculation  

Science Conference Proceedings (OSTI)

This study of low-frequency oceanic variability is based on data collected during the Long Term Upper Ocean Study (LOTUS), which was a two year program of (mainly) moored meteorological and oceanographic measurements. The mooring arrays were ...

Angelika Lippert; Melbourne G. Briscoe

1990-05-01T23:59:59.000Z

40

Contributions of ENSO and East Indian Ocean SSTA to the Interannual Variability of Northwest Pacific Tropical Cyclone Frequency  

Science Conference Proceedings (OSTI)

This study attempts to understand contributions of ENSO and the boreal summer sea surface temperature anomaly (SSTA) in the East Indian Ocean (EIO) to the interannual variability of tropical cyclone (TC) frequency over the western North Pacific (...

Ruifen Zhan; Yuqing Wang; Xiaotu Lei

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Reconstruction of the Extratropical NH Mean Temperature over the Last Millennium with a Method that Preserves Low-Frequency Variability  

Science Conference Proceedings (OSTI)

A new multiproxy reconstruction of the Northern Hemisphere extratropical mean temperature over the last millennium is presented. The reconstruction is performed with a novel method designed to avoid the underestimation of low-frequency variability ...

Bo Christiansen; Fredrik Charpentier Ljungqvist

2011-12-01T23:59:59.000Z

42

Dynamics and Practical Predictability of Extratropical Wintertime Low-Frequency Variability in a Low-Dimensional System  

Science Conference Proceedings (OSTI)

Dynamics and practical predictability of extratropical low-frequency variability (LFV) in Northern Hemisphere winter are examined in the framework of a two-dimensional (2D) stochastic differential equation (SDE) on the phase space spanned by two ...

Masaru Inatsu; Naoto Nakano; Hitoshi Mukougawa

2013-03-01T23:59:59.000Z

43

On Robust Estimation of Low-Frequency Variability Trends in Discrete Markovian Sequences of Atmospheric Circulation Patterns  

Science Conference Proceedings (OSTI)

Identification and analysis of temporal trends and low-frequency variability in discrete time series is an important practical topic in the understanding and prediction of many atmospheric processes, for example, in analysis of climate change. ...

Illia Horenko

2009-07-01T23:59:59.000Z

44

The Application Research of AC Frequency Conversion Technique in Transmission Control System of Oil Rig  

Science Conference Proceedings (OSTI)

This paper mainly introduced the basic structure and work principle of transmission agent on electric drilling rig, meanwhile the frequency control and parallel operation of motors used in the transmission agent were analyzed and designed. Using parallel ... Keywords: Rig, Transmission, Frequency control, Parallel Operation Control

Ruifan Yang; Yong Peng

2010-03-01T23:59:59.000Z

45

We study the interaction of a high frequency AC current with a magnetic field in an YBCO thin film by using time  

E-Print Network (OSTI)

an applied magnetic field, and a time varying transport current that does not induce any flux inside the thinWe study the interaction of a high frequency AC current with a magnetic field in an YBCO thin film of flux distributions. We find that the total current distribution can be described as the superposition

Lewis, Robert Michael

46

Low-frequency variability of currents in the deepwater eastern Gulf of Mexico  

E-Print Network (OSTI)

Vertical structure of the low frequency horizontal currents at the northern edge of the Loop Current during eddy shedding events is observed using concurrent hydrographic, moored, and satellite altimetry data from 2005. Dynamic modes are calculated at three deep (~3000 m), full water-column moorings in the eastern Gulf of Mexico. Time-series of the barotropic and first two baroclinic modes are found using a least squares minimization that fits theoretically derived modes to observed moored velocity data. EOF analyses show that the majority of observed variance is explained by a surface-trapped mode that is highly coherent with the temporal amplitudes of the first baroclinic mode, and a lower, but significant percentage of variance is captured in bottom-intensified modes. Amplitudes of the second empirical mode indicate that currents are more coherent in the ocean interior approaching the Loop Current, as more variance is explained by this mode at the southernmost mooring near the Loop Current. A dynamic mode decomposition of the horizontal currents reveals that the barotropic and first baroclinic modes exhibit low frequency variability and eddy time scales of 10 – 40 days. Second baroclinic mode amplitudes show higher frequency variability and shorter time scales. A model utility test for the least squares fit of modeled to observed velocity shows that the second baroclinic mode is useful to the statistical model during 50 – 85 % of the mooring deployment, and is particularly necessary to the model when cyclonic features are present in the study area. The importance of the second baroclinic mode to the model increases significantly closer to the Loop Current. High-speed currents associated with the Loop Current and anticyclones stimulate a strong first baroclinic response, but the second baroclinic mode amplitudes are found to be similar in magnitude to the first baroclinic mode amplitudes at times. This happens episodically and could be an indication of higher order dynamics related to frontal eddies or Loop Current eddy shedding.

Cole, Kelly Lynne

2008-08-01T23:59:59.000Z

47

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

DOE Green Energy (OSTI)

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.

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

2011-12-01T23:59:59.000Z

48

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

E-Print Network (OSTI)

AC Converter for Grid-tied Energy Storage System Xiaolei Hu,resources, grid-tied energy storage systems voltage to abe increasingly incorporated. Energy storage devices allows

King Jet, Tseng

2013-01-01T23:59:59.000Z

49

Transverse electric conductivity and dielectric permeability in quantum degenerate collisional plasma with variable collision frequency in Mermin's approach  

E-Print Network (OSTI)

Formulas for transverse conductance and dielectric permeability in quantum degenerate collisional plasma with arbitrary variable collision frequency in Mermin's approach are deduced. Frequency of collisions of particles depends arbitrarily on a wave vector. For this purpose the kinetic Shr\\"{o}dinger - Boltzmann equation with collision integral of relaxation type in momentum space is applied. The case of degenerate Fermi plasma is allocated and investigated. The special case of frequency of collisions proportional to the module of a wave vector is considered. The graphic analysis of the real and imaginary parts of dielectric function is made.

Latyshev, A V

2013-01-01T23:59:59.000Z

50

Development of a New Class of Low Cost, High Frequency Link Direct DC to AC Converters for Solid Oxide Fuel Cells (SOFC)  

SciTech Connect

This project proposes to design and develop a new class of power converters (direct DC to AC) to drastically improve performance and optimize the cost, size, weight and volume of the DC to AC converter in SOFC systems. The proposed topologies employ a high frequency link; direct DC to AC conversion approach. The direct DC to AC conversion approach is more efficient and operates without an intermediate dc-link stage. The absence of the dc-link, results in the elimination of bulky, aluminum electrolytic capacitors, which in turn leads to a reduction in the cost, volume, size and weight of the power electronic converter. The feasibility of two direct DC to AC converter topologies and their suitability to meet SECA objectives will be investigated. Laboratory proto-type converters (3-5kW) will be designed and tested in Phase-1. A detailed design trade-off study along with the test results will be available in the form of a report for the evaluation of SECA Industrial partners. This project proposes to develop a new and innovative power converter technology suitable for Solid Oxide Fuel Cell (SOFC) power systems in accordance with SECA objectives. The proposed fuel cell inverter (FCI) employs state of the art power electronic devices configured in two unique topologies to achieve direct conversion of DC power (24-48V) available from a SOFC to AC power (120/240V, 60Hz) suitable for utility interface and powering stand alone loads. The primary objective is to realize cost effective fuel cell converter, which operates under a wide input voltage range, and output load swings with high efficiency and improved reliability.

Prasad Enjeti; J.W. Howze

2003-12-01T23:59:59.000Z

51

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

E-Print Network (OSTI)

Induction motors and Variable Frequency Drives (VFDs) are widely used in industry to drive machinery trains. However, some mechanical trains driven by VFD-motor systems have encountered torsional vibration problems. This vibration can induce large stresses on shafts and couplings, and reduce the lifetime of these mechanical parts. Long before the designed lifetime, the mechanical train may encounter failure. This thesis focuses on VFDs with voltage source rectifiers for squirrel-cage induction motors of open-loop Volts/Hertz and closed-loop Field Oriented Control (FOC). First, the torsional vibration problems induced by VFDs are introduced. Then, the mathematical model for a squirrel-cage induction motor is given. Two common control methods used in VFD are discussed - open-loop Volts/Hertz and closed-loop FOC. SimPowerSystems and SimMechanics are used as the modeling software for electrical systems and mechanical systems respectively. Based on the models and software, two interface methods are provided for modeling the coupled system. A simple system is tested to verify the interface methods. The study of open-loop Volts/Hertz control method is performed. The closed-form of electromagnetic torque sideband frequency due to Pulse Width Modulation is given. A torsional resonance case is illustrated. The effects of non-ideal power switches are studied, which shows little in uence on the system response but which uses little energy consumption. A study of a non-ideal DC bus indicates that a DC bus voltage ripple can also induce a big torsional vibration. Next, the study of the closed-loop FOC control method is presented. Simulation for a complete VFD machinery train is performed. With the recti er and DC bus dynamic braking, the system shows a better performance than the ideal-DC bus case. Lastly, a parametric study of the FOC controller is performed. The effects of primary parameters are discussed. The results indicate that some control parameters (i.e. speed ramps, proportional gain in speed PI controller) are also responsible for the mechanical torsional vibration.

Han, Xu

2010-12-01T23:59:59.000Z

52

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

SciTech Connect

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.

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

53

Experimental Analysis of Variable Capacity Heat Pump Systems equipped with a liquid-cooled frequency inverter.  

E-Print Network (OSTI)

?? Using an inverter-driven compressor in variable capacity heat pump systems has a main drawback, which is the extra loss in the inverter. The present… (more)

Ebraheem, Thair

2013-01-01T23:59:59.000Z

54

Section 5.7.2 Variable-Frequency Motors: Greening Federal Facilities...  

NLE Websites -- All DOE Office Websites (Extended Search)

major VFD designs are commonly used: pulse- width modulation (PWM), current source inverter (CSI), and variable voltage inverter (VVI). A fourth type, the flux vector PWM drive,...

55

A Minimal Baroclinic Model for the Statistical Properties of Low-Frequency Variability  

Science Conference Proceedings (OSTI)

A recent analysis of atmospheric observations has shown evidence of bimodality in the statistical distribution of wave amplitude in the ultralong (zonal wavenumber group 2–4), low frequency (period >5 days). Similar analysis of the zonal wind and ...

R. Benzi; A. Speranza; A. Sutera

1986-12-01T23:59:59.000Z

56

High-Frequency Variability in Hurricane Power Dissipation and Its Relationship to Global Temperature  

Science Conference Proceedings (OSTI)

The power dissipation of Atlantic tropical cyclones has risen dramatically during the last decades and the increase is correlated with an increase in the underlying sea surface temperature (SST) at low (decadal) frequencies. Because of the large ...

James B. Elsner; Anastasios A. Tsonis; Thomas H. Jagger

2006-06-01T23:59:59.000Z

57

A Linear Model of Wintertime Low-Frequency Variability. Part I: Formulation and Forecast Skill  

Science Conference Proceedings (OSTI)

A linear inverse model (LIM) suitable for studies of atmospheric extratropical variability on longer than weekly timescales is constructed using observations of the past 30 years. Notably, it includes tropical diabatic heating as an evolving ...

Christopher R. Winkler; Matthew Newman; Prashant D. Sardeshmukh

2001-12-01T23:59:59.000Z

58

Dynamical Origin of Low-Frequency Variability in a Highly Nonlinear Midlatitude Coupled Model  

Science Conference Proceedings (OSTI)

A novel mechanism of decadal midlatitude coupled variability, which crucially depends on the nonlinear dynamics of both the atmosphere and the ocean, is presented. The coupled model studied involves quasigeostrophic atmospheric and oceanic ...

S. Kravtsov; P. Berloff; W. K. Dewar; M. Ghil; J. C. McWilliams

2006-12-01T23:59:59.000Z

59

North Atlantic modeling of low-frequency variability in mode water formation  

E-Print Network (OSTI)

The generation of interannual and near-decadal variability in the formation of mode waters in the western North Atlantic is investigated in the realistic framework of an isopycnic coordinate ocean model forced with atmospheric data from 1946 to 1988. At Bermuda, the model reproduces quite well the observed potential vorticity and isopycnal depth anomalies associated with the subtropical mode water (STMW). Heat storage and preconditioning of the convective activity are found to be the important factors for the generation of STMW variability, with persistence of cold (warm) conditions, associated with anomalous heat loss (gain) over the western subtropics, being more significant for the generation of the simulated variability than are strong anomalous events in isolated years. In the Labrador Sea, the model captures the phase and order of magnitude of the observed near-decadal variability in the convective activity, if not its maximum amplitude. The simulated potential vorticity anomali...

Afonso M. Paiva; Eric P. Chassignet

2001-01-01T23:59:59.000Z

60

Evaporation-Wind Feedback and Low-Frequency Variability in the Tropical Atmosphere  

Science Conference Proceedings (OSTI)

A mechanism by which feedback between zonal wind perturbations and evaporation can create unstable, low-frequency modes in a simple two-layer model of the tropical troposphere is presented. The modes resemble the 30–50 day oscillation. A series ...

J. David Neelin; Isaac M. Held; Kerry H. Cook

1987-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Summer Severe-Rainfall Frequency Trend and Variability over Ontario, Canada  

Science Conference Proceedings (OSTI)

During the last two decades (1979–2002), there has been an ever-increasing frequency of summer severe-rainfall events over Ontario, Canada. This observed upward trend is robust as demonstrated through the Mann–Kendall test with consideration of ...

Zuohao Cao; Jianmin Ma

2009-09-01T23:59:59.000Z

62

Ocean Model Diagnosis of Low-Frequency Climate Variability in the South Atlantic Region  

Science Conference Proceedings (OSTI)

South Atlantic Ocean variability is investigated by means of an ocean general circulation model (ORCA2), forced with the NCEP–NCAR reanalyses for the 1948–99 period. A rotated EOF analysis of the mixed layer temperature suggests a breakdown of ...

Frank Colberg; C. J. C. Reason

2007-03-01T23:59:59.000Z

63

The Influence of Midlatitude Ocean–Atmosphere Coupling on the Low-Frequency Variability of a GCM. Part I: No Tropical SST Forcing  

Science Conference Proceedings (OSTI)

This study examines the extent to which the thermodynamic interactions between the midlatitude atmosphere and the underlying oceanic mixed layer contribute to the low-frequency atmospheric variability. A general circulation model, run under ...

Ileana Bladé

1997-08-01T23:59:59.000Z

64

The Ocean Response to Low-Frequency Interannual Atmospheric Variability in the Mediterranean Sea. Part I: Sensitivity Experiments and Energy Analysis  

Science Conference Proceedings (OSTI)

In this study a general circulation model is used in order to investigate the interannual response of the Mediterranean Basin to low-frequency interannual variability in atmospheric forcing for the period 1980–88. The model incorporates a ...

G. Korres; N. Pinardi; A. Lascaratos

2000-02-01T23:59:59.000Z

65

A Qualitatively Realistic Low-Order Model of the Extratropical Low-Frequency Variability Built from Long Records of Potential Vorticity  

Science Conference Proceedings (OSTI)

A low-order deterministic qualitative model is formulated in order to simulate extratropical low-frequency variability. This deterministic model is based on a filtering of the potential vorticity equation on the 315-K isentrope and a projection ...

Eduardo Da Costa; Robert Vautard

1997-04-01T23:59:59.000Z

66

Transverse electric conductivity and dielectric permeability in quantum non-degenerate and maxwellian collisional plasma with variable collision frequency in Mermin's approach  

E-Print Network (OSTI)

Formulas for transverse conductance and dielectric permeability in quantum non-degenerate and Maxwellian collisional plasma with arbitrary variable collision frequency in Mermin's approach are deduced. Frequency of collisions of particles depends arbitrarily on a wave vector. The special case of frequency of collisions proportional to the module of a wave vector is considered. The graphic analysis of the real and imaginary parts of dielectric function is made.

Latyshev, A V

2013-01-01T23:59:59.000Z

67

The frequency dependent impedance of an HVdc converter  

Science Conference Proceedings (OSTI)

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.

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

1995-07-01T23:59:59.000Z

68

Measured Savings of DC to AC Drive Retrofit in Plastic Extrusion  

E-Print Network (OSTI)

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 brief background on the extrusion process is presented along with typical extrusion machine electrical drive performance requirements. Motor performance characteristics and control strategies are described for both AC and DC machines. A case study is presented, where detailed electrical measurements were performed on two similar extrusion machines driven by a DC motor and an AC motor respectively. Electrical energy, demand, and cost savings are analyzed

Sfeir, R. A.

2008-01-01T23:59:59.000Z

69

The ACS LCID Project. I. Short-Period Variables in the Isolated Dwarf Spheroidal Galaxies Cetus & Tucana  

E-Print Network (OSTI)

(abridged) We present the first study of the variable star populations in the isolated dwarf spheroidal galaxies (dSph) Cetus and Tucana. Based on Hubble Space Telescope images obtained with the Advanced Camera for Surveys in the F475W and F814W bands, we identified 180 and 371 variables in Cetus and Tucana, respectively. The vast majority are RR Lyrae stars. In Cetus we also found three anomalous Cepheids, four candidate binaries and one candidate long-period variable (LPV), while six anomalous Cepheids and seven LPV candidates were found in Tucana. Of the RR Lyrae stars, 147 were identified as fundamental mode (RRab) and only eight as first-overtone mode (RRc) in Cetus, with mean periods of 0.614 and 0.363 day, respectively. In Tucana we found 216 RRab and 82 RRc giving mean periods of 0.604 and 0.353 day. These values place both galaxies in the so-called Oosterhoff Gap, as is generally the case for dSph. We calculated the distance modulus to both galaxies using different approaches based on the properties ...

Bernard, Edouard J; Gallart, Carme; Drozdovsky, Igor; Stetson, Peter B; Aparicio, Antonio; Cassisi, Santi; Mayer, Lucio; Cole, Andrew A; Hidalgo, Sebastian L; Skillman, Evan D; Tolstoy, Eline

2009-01-01T23:59:59.000Z

70

Low-Frequency Variability, Coherence Resonance, and Phase Selection in a Low-Order Model of the Wind-Driven Ocean Circulation  

Science Conference Proceedings (OSTI)

In this paper, a low-order spectral quasigeostrophic (QG) model of the wind-driven ocean circulation is derived and used to analyze the low-order character of the intrinsic low-frequency variability of the midlatitude double-gyre ocean circulation ...

Stefano Pierini

2011-09-01T23:59:59.000Z

71

Comparison on control strategies of the grid-side converter of variable speed constant frequency doubly-fed wind power generation system  

Science Conference Proceedings (OSTI)

Direct power control, vector control based on d-q synchronous rotating reference frame and ?-? static reference frame for the grid-side converter of variable speed constant frequency doubly-fed wind turbines are analyzed. System simulation ... Keywords: ?-? static reference frame, d-q rotating reference frame, direct power control, doubly-fed wind power generation system, grid-side converter

Xian-Ming Zhou; Ting-Long Pan; Zhi-Cheng Ji

2009-06-01T23:59:59.000Z

72

Free piston variable-stroke linear-alternator generator ...  

A free-piston variable stroke linear-alternator AC power generator for a combustion engine. An alternator mechanism and oscillator system generates AC current. The ...

73

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

E-Print Network (OSTI)

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) for typical fan and pump loads. It also discusses advantages and disadvantages of using mechanical MC-ASD versus VFDs and it provides field experience with VFDs in refrigerated warehouses as well as the fixed magnet MC-ASD in wastewater and other field applications. Laboratory tests for a 50 hp fan retrofit showed electronic VFD savings at 62%, the MagnaDrive Coupling at 39% and PAYBACK Drive at 46%. At $0.06/kWh and list prices, the simple payback for the VFD is 2.4 years, the MagnaDrive is 4.6 years and the PAYBACK is 1.9 years. MagnaDrive has models from 25 to 500 hp while PAYBACK has models from 3 to 200 hp. Contractors to the Northwest Energy Efficiency Alliance have helped to install VFDs for about 300 evaporator fans in over two dozen refrigerated warehouses and to install fixed-magnet MC-ASDs in about 50 applications with about half of these controlling wastewater pumps. The Alliance has no particular field experience with the electcromagnetic coupling. The primary advantages of magnetically coupled adjustable speed drives (MC-ASD) over VFDs come from reduced maintenance, resistance to dirty environments, separation of load vibration from the motor, and less stringent requirements for precise shaft alignment. Field experience indicates reductions in noise and repairs from vibration loads, tolerance of poor electrical power quality, and ease of installation are often more important than energy savings. The MC-ASDs are being used where VFDs have not survived or are considered too complicated.

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

2003-05-01T23:59:59.000Z

74

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

E-Print Network (OSTI)

nation’s mix of generation sources changes. The potentiallarge conventional generation sources can be used as a toolVariable Renewable Generation Source: Undrill (2010) Figure

Eto, Joseph H.

2011-01-01T23:59:59.000Z

75

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

E-Print Network (OSTI)

Integration of Variable Renewable Generation The report isISO (CAISO). 2007. Integration of Renewable Resources.recommendations for integrating renewable resources on the

Eto, Joseph H.

2011-01-01T23:59:59.000Z

76

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

E-Print Network (OSTI)

control because the industry assumed that power system operationsPower system operations planners conduct extensive studies to assess whether primary frequency controlcontrol is a fundamental requirement for reliable operation of any power system.

Eto, Joseph H.

2011-01-01T23:59:59.000Z

77

Climate Variability and the Frequency of Extreme Temperature Events for Nine Sites across Canada: Implications for Power Usage  

Science Conference Proceedings (OSTI)

To study the impact of incremental climatic warming on summer extreme temperature event frequency, the historical record of daily maximum June, July, and August temperatures was analyzed for nine sites across Canada. It was found that all of ...

Andrew F. Colombo; David Etkin; Bryan W. Karney

1999-08-01T23:59:59.000Z

78

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

Science Conference Proceedings (OSTI)

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.

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

1995-08-01T23:59:59.000Z

79

Seasonal and Low-Frequency Variability of the Meridional Heat Flux at 36°N in the North Atlantic  

Science Conference Proceedings (OSTI)

Historical hydrographic sections are used to investigate the seasonal and interannual variability in the meridional heat flux at 36°N in the North Atlantic. The data consist of ten transatlantic sections and sections from four sectors, which ...

Olga T. Sato; T. Rossby

2000-03-01T23:59:59.000Z

80

Low-Frequency Variability of the Equatorial Pacific Ocean Using a New Pseudostress Dataset: 1930–1989  

Science Conference Proceedings (OSTI)

Interannual and interdecadal variability of the equatorial Pacific are examined using a new pseudostress dataset. The monthly mean pseudostress fields (1930–89)are derived from Comprehensive Ocean-Atmosphere Data Set (COADS) pseudostresses using ...

Jay F. Shriver; James J. O'Brien

1995-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Longitudinal electric conductivity and dielectric permeability in quantum plasma with variable frequency of collisions in Mermin' approach  

E-Print Network (OSTI)

Formulas for longitudinal electric conductivity and dielectric permeability in the quantum non-degenerate collisional plasma with the frequency of collisions depending on momentum in Mermin' approach are received. The kinetic equation in momentum space in relaxation approximation is used. It is shown that when Planck's constant tends to zero, the deduced formula passes to the corresponding formula for classical plasma. It is shown also that when frequency of collisions of particles of plasma tends to zero (plasma passes to collisionless one), the deduced formula passes to the known Lindhard' formula received for collisionless plasmas. It is shown, that when frequency of collisions is a constant, the deduced formula for dielectric permeability passes in known Mermin' formula.

A. V. Latyshev; A. A. Yushkanov

2012-12-22T23:59:59.000Z

82

Longitudinal electric conductivity and dielectric permeability in quantum plasma with variable frequency of collisions in Mermin' approach  

E-Print Network (OSTI)

Formulas for longitudinal electric conductivity and dielectric permeability in the quantum non-degenerate collisional plasma with the frequency of collisions depending on momentum in Mermin' approach are received. The kinetic equation in momentum space in relaxation approximation is used. It is shown that when Planck's constant tends to zero, the deduced formula passes to the corresponding formula for classical plasma. It is shown also that when frequency of collisions of particles of plasma tends to zero (plasma passes to collisionless one), the deduced formula passes to the known Lindhard' formula received for collisionless plasmas. It is shown, that when frequency of collisions is a constant, the deduced formula for dielectric permeability passes in known Mermin' formula.

Latyshev, A V

2012-01-01T23:59:59.000Z

83

Time-Frequency Analysis of GALLEX and GNO Solar Neutrino Data: Evidence Suggestive of Asymmetric and Variable Nuclear Burning  

E-Print Network (OSTI)

Time-frequency analysis of data from the GALLEX and GNO solar neutrino experiments shows that some features in power-spectrum analyses of those datasets are due to aliasing. We normalize data for each of the four experiments in the GALLEX series, concatenate the resulting normalized data, and then form time-frequency displays. We also form time-frequency displays of the two principal modulations found in the data, at 11.87 yr-1 and at 13.63 yr-1, and of the datasets formed by subtracting these modulations from the actual (normalized) data. The results suggest that the true modulation is that at 11.87 yr-1, consistent with the results of our earlier analysis of Homestake solar neutrino data. Comparison with helioseismology data indicates that modulation is occurring either in the radiative zone just below the tachocline, presumably by the RSFP (resonant spin-flavor precession) process, or in the core, presumably due to inhomogeneities and fluctuations in the nuclear-burning process.

P. A. Sturrock

2008-02-22T23:59:59.000Z

84

Using Genetic Algorithms to Optimize ACS-TSP  

Science Conference Proceedings (OSTI)

We propose the addition of Genetic Algorithms to Ant Colony System (ACS) applied to improve performance. Two modifications are proposed and tested. The first algorithm is a hybrid between ACS-TSP and a Genetic Algorithm that encodes experimental variables ...

Marcin L. Pilat; Tony White

2002-09-01T23:59:59.000Z

85

Fourier decomposition and frequency analysis of the pulsating stars with PRRc and RRab variables. Separation criteria and particularities  

E-Print Network (OSTI)

The OGLE database is revisited to investigate in more detail the properties of the Fourier parameters. Methodological improvements led us to identify a clear separation among High-Amplitude Delta Scuti (HADS), RRc and RRab stars. The bimodal distribution of the R21 parameter in HADS stars is explained as a contamination effect from RRc stars: there is evidence that all stars with 0.20RRc variables. The previously claimed existence of a subclass of unusual HADS is demonstrated to be a spurious result. Candidate overtone pulsators are found among HADS and RRc variables. The properties of the Fourier parameters are discussed as a function of the physical conditions in the stars involved. Among the field RRab stars we detected different light-curve groups producing distinct "tails" in the Fourier plots for P>0.55 d; evolutionary phases or the combination of different physical conditions (not only metallicity) are suggested to explain this separation, observed also in the cluster RRab stars. The stellar parameters of RRc stars in a given globular cluster show different tendencies than those of RRc stars from different clusters.

Ennio Poretti

2001-03-29T23:59:59.000Z

86

Increasing the energetic efficiency in producing of electric and thermal power in thermal power plants by using of variable speed  

Science Conference Proceedings (OSTI)

In this work is presenting a theoretical analysis and an experimental application of the energetic efficiency increase by using of variable-speed AC electric drive systems in a thermal power plant that produces electric and thermal power. Are presented ... Keywords: asynchronous motor, district heating system, energetic efficiency, harmonic distorsion generated by adjustable speed drives, pumping station, static frequency converter, testing

Sorin Ioan Deaconu; Gabriel Nicolae Popa; Iosif Popa

2008-09-01T23:59:59.000Z

87

AC | OpenEI  

Open Energy Info (EERE)

AC AC Dataset Summary Description The following data-set is for a benchmark residential home for all TMY3 locations across all utilities in the US. The data is indexed by utility service provider which is described by its "unique" EIA ID ( Source National Renewable Energy Laboratory Date Released April 05th, 2012 (2 years ago) Date Updated April 06th, 2012 (2 years ago) Keywords AC apartment CFL coffeemaker Computer cooling cost demand Dishwasher Dryer Furnace gas HVAC Incandescent Laptop load Microwave model NREL Residential television tmy3 URDB Data text/csv icon Residential Cost Data for Common Household Items (csv, 14.5 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Annually Time Period License License Open Data Commons Public Domain Dedication and Licence (PDDL)

88

AC Capabilities  

NLE Websites -- All DOE Office Websites (Extended Search)

Standards Laboratory Metrology Program AC Electrical Fact Sheet SAND2008-5221P Unlimited Release. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed...

89

Frequency modulation drive for a piezoelectric motor  

DOE Patents (OSTI)

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.

Mittas, Anthony (Albuquerque, NM)

2001-01-01T23:59:59.000Z

90

Relationships between Systematic Errors in Medium Range Numerical Forecasts and Some of the Principal Modes of Low-Frequency Variability of the Northern Hemisphere 700 mb Circulation  

Science Conference Proceedings (OSTI)

The relationship between the existence of low-frequency 700 mb height anomalies in the initial conditions of NMC's MRF global spectral model and subsequent 5-, 7-, and 10-day forecasts of 700 mb height from 1982 to 1988 is explored. Low-frequency ...

Edward A. O'Lenic; Robert E. Livezey

1989-06-01T23:59:59.000Z

91

Effective switching frequency multiplier inverter  

SciTech Connect

A switching frequency multiplier inverter for low inductance machines that uses parallel connection of switches and each switch is independently controlled according to a pulse width modulation scheme. The effective switching frequency is multiplied by the number of switches connected in parallel while each individual switch operates within its limit of switching frequency. This technique can also be used for other power converters such as DC/DC, AC/DC converters.

Su, Gui-Jia (Oak Ridge, TN); Peng, Fang Z. (Okemos, MI)

2007-08-07T23:59:59.000Z

92

mat.univie.ac  

E-Print Network (OSTI)

Neumaier@univie.ac.at. Abstract. Results are ...... http://www.mat.univie.ac.at/ neum/glopt/coconut/tests/figures/ ... [11] GAMS World, WWW-document, 2002.

93

AC-DC Difference  

Science Conference Proceedings (OSTI)

... The NIST ac-dc Difference Project provides US industry with the essential link between ac ... Facilities/Tools Used: ... NIST CNST Nanofabrication facility. ...

2012-08-09T23:59:59.000Z

94

Low-Frequency Variability of Temperature in the Vicinity of the Equatorial Pacific Thermocline in SODA: Role of Equatorial Wave Dynamics and ENSO Asymmetry  

Science Conference Proceedings (OSTI)

The Simple Ocean Data Assimilation (SODA) reanalysis (1958–2001) is used to investigate the decadal variability in the equatorial thermocline in the Pacific. Whereas the thermocline depth exhibits weak variation at decadal time scales, the ...

B. Dewitte; S. Thual; S-W. Yeh; S-I. An; B-K. Moon; B. S. Giese

2009-11-01T23:59:59.000Z

95

Screw Type Ac Air Compressor Manufacturers, Screw Type Ac Air ...  

U.S. Energy Information Administration (EIA)

Screw Type Ac Air Compressor, Screw Type Ac Air Compressor Manufacturers & Suppliers Directory - Find here Screw Type Ac Air Compressor Traders, ...

96

State Laboratory Contacts AC  

Science Conference Proceedings (OSTI)

State Laboratory Contact Information AC. Alabama. Mailing Address, ... PDF. Alaska. Mailing Address, Contact Information. Alaska ...

2013-08-01T23:59:59.000Z

97

Integrating Variable Renewable Energy: Challenges and Solutions  

NLE Websites -- All DOE Office Websites (Extended Search)

LLC This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.govpublications. Contract No. DE-AC36-08GO28308 Integrating Variable...

98

Anisotropic high temperature superconductors as variable resistors and switches  

Science Conference Proceedings (OSTI)

Several anisotropic high temperature superconductors show critical current densities which are strongly dependent on the direction of an applied external magnetic field. The resistance of a sample can change by several orders of magnitude by applying a magnetic field. The potential for using the field dependent variable resistor or switch for applications in power systems is evaluated. Test results with small samples are presented. The requirements for large scale applications are outlined. The magnetic field triggering requirement, the frequency response of the device, use in 60 Hz ac circuits and heat transfer consideration are investigated. Several application examples are discussed. Use of variable resistor as a fault current limiter, as a switching element in rectifier circuitry and as an improved dump resistor for a superconducting magnet is presented.

Boenig, H.J.; Daugherty, M.A.; Fleshler, S.; Maley, M.P.; Mueller, F.M.; Prenger, F.C.; Coulter, J.Y.

1994-12-01T23:59:59.000Z

99

M2ACS | M2ACS Web Space  

NLE Websites -- All DOE Office Websites (Extended Search)

Welcome to the Multifaceted Mathematics for Complex Energy Systems (M2ACS) Welcome to the Multifaceted Mathematics for Complex Energy Systems (M2ACS) project webspace We are a multi-institution project whose aim is to fully explore the opportunities in applied mathematics brought about by multi-disciplinary focus - involving optimization, dynamical systems, stochastic analysis, discrete mathematics, scalable algorithms - on the DOE Grand Challenge of energy systems. The central research concept is the one of multi-faceted mathematics - whereby new mathematics is discovered by sustained investigation of the multiple facets presented by the grand challenge subproblems, such as nonconvexity, stochasticity, integrality, spatio-temporal variability - from the perspective of all the mathematics discipline area involved. Our project involves 22 principal investigators from 3 national

100

Stabilizing technique for AC-DC boost PFC converter based on time delay feedback  

Science Conference Proceedings (OSTI)

It is well known that the ac-dc power factor correction (PFC) boost preregulator can present instability at the line frequency. This nonlinear phenomenon can jeopardize the system performances by increasing the total harmonic distortion and decreasing ... Keywords: ac-dc converters, line frequency instability, power factor correction (PFC), time delay feedback (TDF)

Abdelali El Aroudi; Mohamed Orabi

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

VARIABLE TIME-INTERVAL GENERATOR  

DOE Patents (OSTI)

This patent relates to a pulse generator and more particularly to a time interval generator wherein the time interval between pulses is precisely determined. The variable time generator comprises two oscillators with one having a variable frequency output and the other a fixed frequency output. A frequency divider is connected to the variable oscillator for dividing its frequency by a selected factor and a counter is used for counting the periods of the fixed oscillator occurring during a cycle of the divided frequency of the variable oscillator. This defines the period of the variable oscillator in terms of that of the fixed oscillator. A circuit is provided for selecting as a time interval a predetermined number of periods of the variable oscillator. The output of the generator consists of a first pulse produced by a trigger circuit at the start of the time interval and a second pulse marking the end of the time interval produced by the same trigger circuit.

Gross, J.E.

1959-10-31T23:59:59.000Z

102

T-ACS/RoboCrane  

Science Conference Proceedings (OSTI)

Page 1. T-ACS/RoboCrane ... T-ACS (Tactical Auxiliary Crane Ships) T-ACS photo's and drawing courtesy US Navy and/or August Design, Inc. ...

2011-08-25T23:59:59.000Z

103

ACS Symposium Program  

NLE Websites -- All DOE Office Websites (Extended Search)

the Divisions of Biological Chemistry, Environmental Chemistry, Chemical Education, Geochemistry, and Inorganic Chemistry as part of the ACS Division of Analytical Chemistry...

104

Integration and system tests of the Ford/General Electric ac electric drive system  

SciTech Connect

An advanced alternating current electric drive system is being developed by the General Electric Company for Ford Motor Company's ''Advanced Electric Vehicle Powertrain Effort,'' which is a major element of DOE's Single Shaft Electric Propulsion System Program. The integrated transaxle consists of an oil-cooled 50 hp ac induction motor mounted within a 2-speed transaxle. Direct current from the nominal 204 V battery pack is converted to variable frequency, variable voltage 3-phase ac current by a liquid-cooled transistor inverter. A custom-designed inverter motor controller, containing two 8751 microcomputers plus analog and digital circuitry, translates torque commands from the controller to the inverter transistor base drivers that turn on/off power Darlington transistors at appropriate times. After a review of the electric drive system ratings, details of the transistor inverter are presented. Control strategy and controller design are summarized. Electric drive integration and system test results are given.

King, R.D.; Park, J.N.

1985-01-01T23:59:59.000Z

105

Monitoring method and apparatus using high-frequency carrier  

DOE Patents (OSTI)

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.

Haynes, Howard D. (Knoxville, TN)

1996-01-01T23:59:59.000Z

106

Monitoring method and apparatus using high-frequency carrier  

DOE Patents (OSTI)

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.

Haynes, H.D.

1996-04-30T23:59:59.000Z

107

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

SciTech Connect

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.

Pitel, Ira J. (Whippany, NJ)

1987-02-03T23:59:59.000Z

108

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

SciTech Connect

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.

Pitel, I.J.

1987-02-03T23:59:59.000Z

109

Software | M2ACS  

NLE Websites -- All DOE Office Websites (Extended Search)

Software Algorithm design, high-performance computing and advanced numerical simulations are at the core M2ACS mission. Below is a list of software packages developed or supported...

110

6110AC.DOT  

NLE Websites -- All DOE Office Websites (Extended Search)

Center RESIDUAL INVENTORY OF MATERIAL OR EQUIPMENT FURNISHED BY OR ACQUIRED FOR SANDIA Contractor: SF 6110-AC (10-96) Supersedes (6-87) issue Contractor No.: Item Description...

111

Ac resonant charger with charge rate unrelated to preimary power requency  

DOE Patents (OSTI)

An ac resonant charger for a capacitive load, such as a pulse forming network (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.

Not Available

1979-12-07T23:59:59.000Z

112

ACS | Open Energy Information  

Open Energy Info (EERE)

ACS ACS Jump to: navigation, search Name ACS Place Madrid, Spain Zip 28036 Sector Solar Product Madrid based construction company involved in the development of solar thermal projects. Coordinates 40.4203°, -3.705774° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.4203,"lon":-3.705774,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

113

Free piston variable-stroke linear-alternator generator  

DOE Patents (OSTI)

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.

Haaland, Carsten M. (Dadeville, AL)

1998-01-01T23:59:59.000Z

114

ETA-AC002  

NLE Websites -- All DOE Office Websites (Extended Search)

2 2 Revision 2 Effective March 1, 1997 "Control of Test Conduct" Prepared by Electric Transportation Applications Prepared by: _______________________________ Date:__________ Jude M. Clark Approved by: _________________________________________________ Date: _______________ Donald B. Karner Procedure ETA-AC002 Revision 2 2 ©1997 Electric Transportation Applications All Rights Reserved TABLE OF CONTENTS 1.0 Objectives 3 2.0 Purpose 3 3.0 Documentation 3 4.0 Initial Conditions and Prerequisites 4 5.0 Personnel Qualifications 5 6.0 Activity Requirements 6 7.0 Supplemental Activity Requirements 8 8.0 Glossary 9 9.0 References 10 Procedure ETA-AC002 Revision 2 3 ©1997

115

ETA-AC006  

NLE Websites -- All DOE Office Websites (Extended Search)

6 6 Revision 2 Effective: March 1, 1997 Vehicle Verification Prepared by Electric Transportation Applications Prepared by: _______________________________ Date:__________ Jude M. Clark Approved by: _________________________________________________ Date: ______________ Donald B. Karner ETA-AC006 Revision 2 2 ©1997 Electric Transportation Applications All Rights Reserved TABLE OF CONTENTS 1.0 Objectives 3 2.0 Purpose 3 3.0 Documentation 3 4.0 Initial Conditions and Prerequisites 4 5.0 Verification Requirements 5 6.0 Glossary 11 7.0 References 12 Appendices Appendix A - Manufacturer's Proposal Review Check List 13 Appendix B - Vehicle Receipt Check List 18 ETA-AC006 Revision 2 3

116

Gene Frequency  

NLE Websites -- All DOE Office Websites (Extended Search)

Gene Frequency Gene Frequency Name: donna Location: N/A Country: N/A Date: N/A Question: If six fingers is a dominant human trait why do we have only five? Replies: This is simple. There are just not many genes in the human population for six fingers. Steve Sample Look in any high school biology book for what is known as Hardy-Weinberg equilibrium. These two scientists (separately) said that gene frequencies do not change much unless something in the environment selects them over other genes. In other words, unless 6 fingers somehow becomes an advantage, and five-fingered people have less of an advantage, the frequency of six fingered people in the population will not necessarily increase. This is the same reason that recessive traits don't disappear from the population. Also, six fingers is not considered attractive and they may not get as many mates. Also, more people are born with six fingers than you might imagine but just have them amputated shortly after birth.

117

Variable Screw Compressor, Variable Screw Compressor Suppliers ...  

U.S. Energy Information Administration (EIA)

Variable Screw Compressor Suppliers & air compressor Manufacturers Directory. Source Top Quality Variable Screw Compressor Suppliers, air ...

118

Small Wind Guidebook/What are the Basic Parts of a Small Wind...  

Open Energy Info (EERE)

the kinetic energy of the wind and converts it into rotary motion to drive the generator, which produces either AC or wild AC (variable frequency, variable voltage), which...

119

Variables Affecting Economic Development of Wind Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

Variables Affecting Economic Variables Affecting Economic Development of Wind Energy E. Lantz and S. Tegen National Renewable Energy Laboratory Presented at WINDPOWER 2008 Houston, Texas June 1-4, 2008 Conference Paper NREL/CP-500-43506 July 2008 NREL is operated by Midwest Research Institute â—Ź Battelle Contract No. DE-AC36-99-GO10337 NOTICE The submitted manuscript has been offered by an employee of the Midwest Research Institute (MRI), a contractor of the US Government under Contract No. DE-AC36-99GO10337. Accordingly, the US Government and MRI retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government.

120

May, Locascio Honored as ACS Fellows  

Science Conference Proceedings (OSTI)

May, Locascio Honored as ACS Fellows. ... May and Locascio will be inducted as fellows during the ACS National Meeting in Denver, Colo., on Aug. ...

2011-08-16T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

AC Propulsion | Open Energy Information  

Open Energy Info (EERE)

founded in 1992 to develop, manufacture, and license system and component technology for electric vehicle drive systems. References AC Propulsion1 LinkedIn Connections...

122

Digital slip frequency generator and method for determining the desired slip frequency  

DOE Patents (OSTI)

The output frequency of an electric power generator is kept constant with variable rotor speed by automatic adjustment of the excitation slip frequency. The invention features a digital slip frequency generator which provides sine and cosine waveforms from a look-up table, which are combined with real and reactive power output of the power generator.

Klein, Frederick F. (Monroeville, PA)

1989-01-01T23:59:59.000Z

123

Performance Variability  

NLE Websites -- All DOE Office Websites (Extended Search)

Variability Variability of Highly Parallel Architectures William T.C. Kramer 1 and Clint Ryan 2 1 Department of Computing Sciences, University of California at Berkeley and the National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory 2 Department of Computing Sciences, University of California at Berkeley Abstract. The design and evaluation of high performance computers has concentrated on increasing computational speed for applications. This performance is often measured on a well configured dedicated sys- tem to show the best case. In the real environment, resources are not always dedicated to a single task, and systems run tasks that may influ- ence each other, so run times vary, sometimes to an unreasonably large extent. This paper explores the amount of variation seen across four large distributed memory systems in a systematic manner. It then

124

Alternative Fuels at AC Transit  

NLE Websites -- All DOE Office Websites (Extended Search)

Alternative Fuels at AC Transit Alternative Fuels at AC Transit Speaker(s): Jaimie Levin Date: November 1, 2011 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Eve Edelson Mr. Levin will discuss AC Transit's range of environmental technology initiatives, including: zero emission fuel cell transit buses; state-of-the-art, high-capacity, hydrogen fueling stations; solar energy systems; and stationary solid oxide fuel cell power generators. AC Transit has the largest fleet of fuel cell buses in the United States, featuring fuel cell systems with more than 10,000 hours of continuous operation without any failures or power degradation. Their fuel cell fleet has logged more than 400,000 miles of service and carried in excess of one million passengers. Come hear what AC Transit has learned, where they're headed,

125

Weights and Measures State Directors AC  

Science Conference Proceedings (OSTI)

State Directors AC. Alaska. Mailing Address, Contact Information. Alaska Division of Measurement Standards/CVE 11900 ...

2013-05-03T23:59:59.000Z

126

Low-Frequency Signals in Midtropospheric Submonthly Temperature Variance  

Science Conference Proceedings (OSTI)

Low-frequency signals in the daily variability of temperature in the midtroposphere are investigated, thereby complementing published studies of changes in day-to-day temperature variability and in extreme weather events at the surface. The ...

Haig Iskenderian; Richard D. Rosen

2000-07-01T23:59:59.000Z

127

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

DOE Patents (OSTI)

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.

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

1995-08-15T23:59:59.000Z

128

Weather Noise Forcing of Surface Climate Variability  

Science Conference Proceedings (OSTI)

A model-based method to evaluate the role of weather noise forcing of low-frequency variability of surface properties, including SST, surface currents, land surface temperature, and soil moisture, is presented. In this procedure, an “interactive ...

Edwin K. Schneider; Meizhu Fan

2007-09-01T23:59:59.000Z

129

AC resistance measuring instrument  

DOE Patents (OSTI)

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.

Hof, P.J.

1983-10-04T23:59:59.000Z

130

Variable Renewable Generation Can Provide Balancing Control to...  

NLE Websites -- All DOE Office Websites (Extended Search)

Variable Renewable Generation Can Provide Balancing Control to the Electric Power System e Active Power Control Helps Maintain System Frequency As wind and solar plants become more...

131

Cooperative frequency control with a multi-terminal high-voltage DC network  

Science Conference Proceedings (OSTI)

We consider frequency control in power systems made of several non-synchronous AC areas connected by a multi-terminal high-voltage direct current (HVDC) grid. We propose two HVDC control schemes to make the areas collectively react to power imbalances, ... Keywords: Decentralized control, Frequency control, HVDC systems, Power system control

Alain Sarlette; Jing Dai; Yannick Phulpin; Damien Ernst

2012-12-01T23:59:59.000Z

132

Time and Frequency Portal  

Science Conference Proceedings (OSTI)

NIST Home > Time and Frequency Portal. Time and Frequency Portal. Programs and Projects. CODATA values of the fundamental constants ...

2013-06-27T23:59:59.000Z

133

Ac traction gets on track  

Science Conference Proceedings (OSTI)

This article describes inverter-based ac traction systems which give freight locomotives greater adhesion, pulling power, and braking capacity. In the 1940s, dc traction replaced the steam engine as a source of train propulsion, and it has ruled the freight transportation industry ever since. But now, high-performance ac-traction systems, with their unprecedented levels of pulling power and adhesion, are becoming increasingly common on America`s freight railroads. In thousands of miles of demonstration tests, today`s ac-traction systems have outperformed traditional dc-motor driven systems. Major railroad companies are convinced enough of the benefits of ac traction to have integrated it into their freight locomotives.

O`Connor, L.

1995-09-01T23:59:59.000Z

134

Frequency of Precipitation across the Northern U.S. Corn Belt  

Science Conference Proceedings (OSTI)

Knowledge of the frequency of precipitation events can aid in managing water resources, but little is known concerning the regional variability in the frequency of daily precipitation events in the northern U.S. Corn Belt. The frequency ...

B. S. Sharratt; J. Zandlo; G. Spoden

2001-02-01T23:59:59.000Z

135

Lagrangian Frequency Spectrum as a Diagnostic for Magnetohydrodynamic Turbulence Dynamics  

SciTech Connect

For the phenomenological description of magnetohydrodynamic turbulence competing models exist, e.g., Boldyrev [Phys. Rev. Lett. 96, 115002 (2006)] and Gogoberidze [Phys. Plasmas 14, 022304 (2007)], which predict the same Eulerian inertial-range scaling of the turbulent energy spectrum although they employ fundamentally different basic interaction mechanisms. A relation is found that links the Lagrangian frequency spectrum with the autocorrelation time scale of the turbulent fluctuations {tau}{sub ac} and the associated cascade time scale {tau}{sub cas}. Thus, the Lagrangian energy spectrum can serve to identify weak ({tau}{sub ac}<<{tau}{sub cas}) and strong ({tau}{sub ac{approx}{tau}cas}) interaction mechanisms providing insight into the turbulent energy cascade. The new approach is illustrated by results from direct numerical simulations of two- and three-dimensional incompressible MHD turbulence.

Busse, Angela; Mueller, Wolf-Christian; Gogoberidze, Grigol [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, 85748 Garching (Germany); Georgian National Astrophysical Observatory, 2a Kazbegi Avenue, 0160 Tbilisi (Georgia) and Centre for Plasma Astrophysics, University of Leuven, B-3001 Leuven (Belgium)

2010-12-03T23:59:59.000Z

136

Microsoft Word - HgAcBr  

NLE Websites -- All DOE Office Websites (Extended Search)

(AC-Br) (DARCO Hg- LH, Norit Americas Inc.) and brominated activated carbon fibers (ACF-Br) (Illinois State Geological Survey and University of Illinois). The AC-Br sorbents...

137

Study of power transfer capability of dc systems incorporating ac loads and a parallel ac line  

Science Conference Proceedings (OSTI)

Concepts of maximum power transfer of dc systems and associated ac voltage variations, particularly at inverter stations having low short-circuit ratios, have been extended to include various ac load models and an ac line in parallel with the dc line. The operating capabilities are shown to vary from those predicted from either a Thevenin ac source model or the corresponding short-circuit ratio. The study used an ac/dc load flow program.

Reeve, J.; Uzunovic, E. [Univ. of Waterloo, Ontario (Canada)

1997-01-01T23:59:59.000Z

138

Energy Savings of Variable Speed Motors  

E-Print Network (OSTI)

This paper investigates the energy savings available by utilizing variable speed motors on pump and fan applications. Conventional control of flow or pressure in process plants is normally accomplished by throttling the various streams with control valves. Depending on the system and the actual operating conditions, this throttling may consume a considerable amount of energy. The hydraulics of different systems are investigated to generalize high energy saving applications. Typical pump characteristics at varying speeds are investigated since most performance curves are only available at a constant speed. The various types of variable speed electric motors are discussed. However, the primary variable speed system recommended is a variable frequency speed system which utilizes standard induction motors. Specific cases of centrifugal pump applications and cooling tower fan service are presented. Turndown frequencies, stream factors, and electric rates are included in the evaluation. The energy savings of a variable speed system becomes significant when flow rates vary widely and the electrical rates are high.

Fishel, F. D.

1979-01-01T23:59:59.000Z

139

Calorimetric method of ac loss measurement in a rotating magnetic field  

Science Conference Proceedings (OSTI)

A method is described for calorimetric ac-loss measurements of high-T{sub c} superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup is to demonstrate measuring loss using a temperature rise method under the influence of a rotating magnetic field. The slight temperature increase of the sample in an ac-field is used as a measure of losses. The aim is to simulate the loss in rotating machines using HTS. This is a unique technique to measure total ac loss in HTS at power frequencies. The sample is mounted on to a cold finger extended from a liquid nitrogen heat exchanger (HEX). The thermal insulation between the HEX and sample is provided by a material of low thermal conductivity, and low eddy current heating sample holder in vacuum vessel. A temperature sensor and noninductive heater have been incorporated in the sample holder allowing a rapid sample change. The main part of the data is obtained in the calorimetric measurement is used for calibration. The focus is on the accuracy and calibrations required to predict the actual ac losses in HTS. This setup has the advantage of being able to measure the total ac loss under the influence of a continuous moving field as experienced by any rotating machines.

Ghoshal, P. K. [Oxford Instruments NanoScience, Abingdon, Oxfordshire OX13 5QX (United Kingdom); Coombs, T. A.; Campbell, A. M. [Department of Engineering, Electrical Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)

2010-07-15T23:59:59.000Z

140

ACS_RRA_2001.PDF  

NLE Websites -- All DOE Office Websites (Extended Search)

Qualitative and Semi-quantitative Qualitative and Semi-quantitative Analysis Of Semi-volatile Organics from Ambient Air Fine-particulate Matter, PM 2.5 Richard Anderson, Don Martello, Brian R. Strazisar and Curt M. White richard.anderson@netl.doe.gov ACS-222 / RRA' / ST-10 / 8-28-2001 Different Missions * EPA - Protect the public health * DOE - Assist the private sector in supplying clean, abundant, and affordable energy ACS-222 / RRA' / ST-10 / 8-28-2001 PM 2.5 Regulatory Process * 1997 National Ambient Air Quality Standards (NAAQS) for PM 2.5 based on "health effects" - Mean annual concentration < 15 µg/m 3 - Maximum concentration < 65µg/ m 3 ACS-222 / RRA' / ST-10 / 8-28-2001 Why Is DOE Concerned About PM 2.5 ? * Coal-based power systems contribute to PM 2.5 - Primary particles * Ultra-fine fly-ash (Spherical Alumino-silicates,SAS), carbon soot

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Removing Spurious Low-Frequency Variability in Drifter Velocities  

Science Conference Proceedings (OSTI)

Satellite-tracked drifting buoys of the Global Drifter Program have drogues, centered at 15-m depth, to minimize direct wind forcing and Stokes drift. Drogue presence has historically been determined from submergence or tether strain records. ...

Rick Lumpkin; Semyon A. Grodsky; Luca Centurioni; Marie-Helene Rio; James A. Carton; Dongkyu Lee

2013-02-01T23:59:59.000Z

142

Singular Modes and Low-Frequency Atmospheric Variability  

Science Conference Proceedings (OSTI)

Recently, it has been shown that the EOFs (empirical orthogonal functions) of the solutions of a stationary linear model to an ensemble of white noise forcing fields are the Schmidt modes (singular modes) of the model' linear operator. If the ...

Werner Metz

1994-06-01T23:59:59.000Z

143

Low-Frequency Pycnocline Variability in the Northeast Pacific  

Science Conference Proceedings (OSTI)

The output from an ocean general circulation model (OGCM) driven by observed surface forcing is used in conjunction with simpler dynamical models to examine the physical mechanisms responsible for interannual to interdecadal pycnocline ...

Antonietta Capotondi; Michael A. Alexander; Clara Deser; Arthur J. Miller

2005-08-01T23:59:59.000Z

144

Reliability of the emergency ac power system at nuclear power plants  

SciTech Connect

This paper contains an evaluation of the onsite ac power system reliability. The approach to determine the onsite system reliability is to gather from the operating nuclear plants detailed data that have not been available to the NRC, to select typical but detailed design features, and to combine the two to determine ac power system reliability for different designs. Fault trees were constructed from the specific designs, and the categorized data will be used to calculate a spectrum of the expected frequency of station blackout.

Battle, R.E.; Campbell, D.J.; Baranowsky, P.W.

1982-01-01T23:59:59.000Z

145

Measurements of AC Losses and Current Distribution in Superconducting Cables  

Science Conference Proceedings (OSTI)

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.

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

146

Investigation of Multi-Frequency Power Transmission and System  

E-Print Network (OSTI)

This dissertation presents a new power system transmission concept based on frequency selectivity named Multi-Frequency Power System (MFPS). This system allows for selective power transmission among terminals in an interconnected system, and is enabled by power electronic technology. The dissertation starts with a presentation of some of the challenges faced by modern power systems, and includes a description of various power system technologies developed in an attempt to solve them. Then, our proposed solution is presented as an alternative to electric power transmission, and the fundamental concepts are explained. A version of the MFPS is developed, which has relevance to the problem of renewable sources integration. This AC DC Power System is further explored, and the topology of the system and the converters is presented, as well as the control techniques used in its operation. The dissertation also presents a performance study of the AC DC system, which was done in Simulink, and it demonstrates the robustness of the system under various dynamic and fault conditions. Finally, a summary of the work is given in the last section of the dissertation. The contributions of our research to the state of technology are discussed. These contributions include: the demonstration of power selectivity based on frequency identification, the development of a novel transmission system and a AC DC integrated implementation of it, and the development of a control and converter that enables selective power transmission. Also, some of the most relevant future research initiatives related to this topic are presented.

Barazarte Conte, Ronald

2011-08-01T23:59:59.000Z

147

Assessment of US electric vehicle programs with ac powertrains  

Science Conference Proceedings (OSTI)

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.

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

1990-02-01T23:59:59.000Z

148

Pitch-Controlled Variable-Speed Wind Turbine Generation  

NLE Websites -- All DOE Office Websites (Extended Search)

Pitch-Controlled Variable-Speed Pitch-Controlled Variable-Speed Wind Turbine Generation February 2000 * NREL/CP-500-27143 E. Muljadi and C.P. Butterfield Presented at the 1999 IEEE Industry Applications Society Annual Meeting Phoenix, Arizona October 3-7, 1999 National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401-3393 NREL is a U.S. Department of Energy Laboratory Operated by Midwest Research Institute * * * * Battelle * * * * Bechtel Contract No. DE-AC36-99-GO10337 NOTICE The submitted manuscript has been offered by an employee of the Midwest Research Institute (MRI), a contractor of the US Government under Contract No. DE-AC36-99GO10337. Accordingly, the US Government and MRI retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes.

149

Feasibility study of AC- and DC-side active filters for HVDC converter terminals  

SciTech Connect

This paper evaluates the technical and economic feasibility for active filtering of dc-side voltage harmonics and the ac-side current harmonics produced by a HVDC converter. The following designs for the active filter concepts are compared with the existing ac-side and dc-side passive filters used at the Dickinson terminal of the CU HVDC transmission line project: the dc-side active filter consisting of a capacitor coupled current injection source to actively neutralize the 12th, 24th and the 36th harmonics, and the ac-side active filter designed to provide the same fundamental frequency reactive VARs as the existing passive filters. Controlled currents are injected to actively filter the 11th and 13th harmonic currents. A cost comparison is made between these active filter designs and the cost of the existing passive filters supplied by the United Power Association (UPA).

Wong, C.; Mohan, N. (Minnesota Univ., Minneapolis, MN (USA). Dept. of Electrical Engineering); Wright, S.E. (Electric Power Research Inst., Palo Alto, CA (USA)); Mortenson, K.N. (United Power Association, Elk River, MN (USA))

1989-10-01T23:59:59.000Z

150

A VECTOR ENERGY FUNCTION APPROACH FOR SECURITY ANALYSIS OF AC/DC SYSTEMS  

E-Print Network (OSTI)

This paper examines dynamic behavior in system models that reflect reasonably detailed (third order) HVDC dynamics along with ac system models that include reactive flows, and frequency and voltage dependent load models. A vector Lyapunov function approach is employed to define a system wide energy function that can be used for general security analysis. The paper describes the derivation of individual component Lyapunov functions for simplified models of HVDC links connected to "infinitely strong" ac systems, along with a standard ac only system Lyapunov function. A novel method of obtaining weighting coefficients to sum these components for the overall system energy function is proposed. Use of the new energy function for transient stability and security analysis is illustrated in a test system.

Christopher L. DeMarco; Claudio A. Cańizares

1992-01-01T23:59:59.000Z

151

ExchangesExchanges Newsletter of the Climate Variability and Predictability Programme (CLIVAR)Newsletter of the Climate Variability and Predictability Programme (CLIVAR)  

E-Print Network (OSTI)

. The goals of the workshop were to review the present understanding of the major modes of variability Corresponding Author: i.renfrew@uea.ac.uk recent SH climate change was reviewed. Measures of the SAM were also to take a look at it. Many thanks indeed to Mike Sparrow who has acted as guest editor and dealt

Quartly, Graham

152

VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS  

E-Print Network (OSTI)

This thesis presents a thorough analysis of saddle-node bifurcations for power system dynamic models, including a third order representation of high voltage direct current (HVDC) transmission, classic ac generator dynamics with reactive flows, and voltage and frequency dependent load models. Extensions of the Point of Collapse and Continuation methods, initially used in ac system voltage stability studies, are applied to the determination of these bifurcation points. These methods are compared and used for calculating bus voltage profiles (“nose ” curves) and collapse points on ac/dc systems of up to 2158 buses, considering a variety of operational limits and controls, namely, ac/dc regulating transformer tap limits, voltage and reactive power limits, and area interchange control. AC generator reactive power limits, HVDC firing angle limits and voltage dependent current order limits (VDCOL) are shown to affect the stability and loadability of these systems. A vector Lyapunov function approach is employed to define a system wide energy function that can be used for stability analysis. This thesis describes the derivation

Claudio A. Cańizares

1991-01-01T23:59:59.000Z

153

Recommended Rest Frequencies  

Science Conference Proceedings (OSTI)

Return to Table of Contents NIST Recommended Rest Frequencies for Observed Interstellar Molecular Microwave Transitions. by Frank J. Lovas. ...

154

AOCS Official Method Ac 1-45  

Science Conference Proceedings (OSTI)

Sampling AOCS Official Method Ac 1-45 Methods Methods and Analyses Analytical Chemistry Methods Downloads DEFINITION   SCOPE Applicable to soybeans. 7BEE304BFEC99451

155

Eastern Frequency Response Study  

Science Conference Proceedings (OSTI)

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.

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

2013-05-01T23:59:59.000Z

156

A Numerical Model for Low-Frequency Equatorial Dynamics  

Science Conference Proceedings (OSTI)

A fast, efficient numerical procedure for modeling the linear low-frequency motions on an equatorial beta plane is developed. The model is capable of simulating the seasonal and interannual variability in realistically shaped ocean basins forced ...

Mark A. Cane; Randall J. Patton

1984-12-01T23:59:59.000Z

157

Multiscale Low-Frequency Circulation Modes in the Global Atmosphere  

Science Conference Proceedings (OSTI)

In this paper, fundamental multiscale circulation modes in the global atmosphere are identified with the objective of providing better understanding of atmospheric low-frequency variabilities over a wide range of spatial and temporal scales. With ...

K-M. Lau; P-J. Sheu; I-S. Kang

1994-05-01T23:59:59.000Z

158

Short-Period Variables in the Local Group Dwarf Galaxies Tucana and LGS3  

E-Print Network (OSTI)

We present preliminary results concerning the search for short-period variable stars in Tucana and LGS3 based on very deep HST/ACS imaging. In the fraction of the observed field we studied in each galaxy, a total of 133 and 30 variables were found, respectively. For Tucana, we identified 76 of them as RR Lyrae (RRL) stars pulsating in the fundamental mode (RRab) and 32 in the first-overtone mode (RRc), as well as 2 anomalous Cepheids (AC). The mean period of the RRab and RRc is 0.59 and 0.35 days, respectively. In the case of LGS3, we found 24 RRab and 4 RRc, with mean periods 0.61and 0.39 days, respectively, plus two candidate ACs. These values place both galaxies in the Oosterhoff gap.

Bernard, E J; Gallart, C; Aparicio, A; Bertelli, G; Cassisi, S; Cole, A A; Demarque, P; Dolphin, A E; Drozdovsky, I; Ferguson, H C; Hidalgo, S; Mateo, M; Mayer, L; Navarro, J; Pont, F; Skillman, E D; Stetson, P B; Tolstoy, E

2007-01-01T23:59:59.000Z

159

Short-Period Variables in the Local Group Dwarf Galaxies Tucana and LGS3  

E-Print Network (OSTI)

We present preliminary results concerning the search for short-period variable stars in Tucana and LGS3 based on very deep HST/ACS imaging. In the fraction of the observed field we studied in each galaxy, a total of 133 and 30 variables were found, respectively. For Tucana, we identified 76 of them as RR Lyrae (RRL) stars pulsating in the fundamental mode (RRab) and 32 in the first-overtone mode (RRc), as well as 2 anomalous Cepheids (AC). The mean period of the RRab and RRc is 0.59 and 0.35 days, respectively. In the case of LGS3, we found 24 RRab and 4 RRc, with mean periods 0.61and 0.39 days, respectively, plus two candidate ACs. These values place both galaxies in the Oosterhoff gap.

E. J. Bernard; M. Monelli; C. Gallart; A. Aparicio; G. Bertelli; S. Cassisi; A. A. Cole; P. Demarque; A. E. Dolphin; I. Drozdovsky; H. C. Ferguson; S. Hidalgo; M. Mateo; L. Mayer; J. Navarro; F. Pont; E. D. Skillman; P. B. Stetson; E. Tolstoy

2007-01-25T23:59:59.000Z

160

Quantum teleportation of optical images with frequency conversion  

E-Print Network (OSTI)

We describe a new version of continuous variables quantum holographic teleportation of optical images. Unlike the previously proposed scheme, it is based on the continuous variables quantum entanglement between the light fields of different frequencies and allows for the wavelength conversion between the original and the teleported images. The frequency tunable holographic teleportation protocol can be used as a part of light-matter interface in parallel quantum information processing and parallel quantum memory

Liubov V. Magdenko; Ivan V. Sokolov; Mikhail I. Kolobov

2006-02-24T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Intraseasonal Variability in a Barotropic Model with Seasonal Forcing  

Science Conference Proceedings (OSTI)

It has recently been suggested that oscillatory topographic instability could contribute to low-frequency variability over the Northern Hemisphere midlatitudes. A barotropic potential vorticity model, with a hierarchy of forcing and topography ...

Christopher M. Strong; Fei-Fei Jin; Michael Ghil

1993-09-01T23:59:59.000Z

162

Climatology and Interannual Variability of North Atlantic Hurricane Tracks  

Science Conference Proceedings (OSTI)

The spatial and temporal variability of North Atlantic hurricane tracks and its possible association with the annual hurricane landfall frequency along the U.S. East Coast are studied using principal component analysis (PCA) of hurricane track ...

Lian Xie; Tingzhuang Yan; Leonard J. Pietrafesa; John M. Morrison; Thomas Karl

2005-12-01T23:59:59.000Z

163

ac electric-field-induced resonant energy transfer between cold Rydberg atoms  

E-Print Network (OSTI)

An oscillating electric field at 1.356 GHz was used to promote the resonant energy transfer process: $43d_{5/2}+43d_{5/2} \\to 45p_{3/2}+41f$ between translationally cold $^{85}$Rb Rydberg atoms. The ac Stark shifts due to this dressing field created degeneracies between the initial and final two-atom states of this process. The ac field strength was scanned to collect spectra which are analogous to dc electric-field-induced resonant energy transfer spectra. Different resonances were observed for different magnetic sublevels involved in the process. Compared to earlier work performed at higher frequencies, the choice of dressing frequency and structure of the spectra may be intuitively understood, by analogy with the dc field case.

Petrus, J A; Martin, J D D; 10.1088/0953-4075/41/24/245001

2009-01-01T23:59:59.000Z

164

A New Parsimonious Methodology of Mapping the Spatial Variability of Annual Maximum Rainfall in Mountainous Environments  

Science Conference Proceedings (OSTI)

The estimation of rare frequency rainfall is an essential prerequisite for the design of engineering structures and to determine risk areas. Index-based methods are among the most applied for regional frequency analysis of hydrological variables ...

G. Boni; A. Parodi; F. Siccardi

2008-06-01T23:59:59.000Z

165

Orographic Influences on the Distribution and Generation of Atmospheric Variability in a GCM  

Science Conference Proceedings (OSTI)

The effect of large-scale mountains on atmospheric variability is studied in a series of GCM experiments in which a single mountain is varied in height from 0 to 4 km. High-frequency (? 30 days) variability are ...

Jin-Yi Yu; Dennis L. Hartmann

1995-07-01T23:59:59.000Z

166

Reconstructing the NH Mean Temperature: Can Underestimation of Trends and Variability Be Avoided?  

Science Conference Proceedings (OSTI)

There are indications that hemispheric-mean climate reconstructions seriously underestimate the amplitude of low-frequency variability and trends. Some of the theory of linear regression and error-in-variables models is reviewed to identify the ...

Bo Christiansen

2011-02-01T23:59:59.000Z

167

Understanding Inertial and Frequency Response of Wind Power Plants: Preprint  

DOE Green Energy (OSTI)

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).

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

2012-07-01T23:59:59.000Z

168

Intraseasonal variability of the west African monsoon and African easterly waves during boreal summer.  

E-Print Network (OSTI)

??Substantial subseasonal variability in African easterly wave (AEW) activity and cyclogenesis frequency occurs in the main hurricane development region of the Atlantic during boreal summer.… (more)

Alaka, Ghassan J.

2010-01-01T23:59:59.000Z

169

primary frequency standards  

Science Conference Proceedings (OSTI)

NIST-F1 Cesium Fountain Atomic Clock The Primary Time and Frequency Standard for the United States. NIST-F1, the nation's ...

2013-02-04T23:59:59.000Z

170

Stabilized radio frequency quadrupole  

DOE Patents (OSTI)

Disclosed is 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 figs.

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

1984-12-25T23:59:59.000Z

171

Estimating frequency of change  

Science Conference Proceedings (OSTI)

Many online data sources are updated autonomously and independently. In this article, we make the case for estimating the change frequency of data to improve Web crawlers, Web caches and to help data mining. We first identify various scenarios, where ... Keywords: Change frequency estimation, Poisson process

Junghoo Cho; Hector Garcia-Molina

2003-08-01T23:59:59.000Z

172

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

E-Print Network (OSTI)

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 to stages toward compact realization, increased high-power handling capability, and improving utility interface. Modern ac/ac power converter topologies with various control strategies have been introduced for the further improvements, such as matrix converters, current-fed converters, PWM rectifiers, and active power filters. In this dissertation, several new converter topologies are proposed in conjunction with developed control schemes based on the modern ac/ac converters which enhance performance and solve the drawbacks of conventional converters. In this study, a new fault-tolerant PWM strategy is first proposed for matrix converters. The added fault-tolerant scheme would strengthen the matrix converter technology for aerospace and military applications. A modulation strategy is developed to reshape output currents for continuous operation, against fault occurrence in matrix converter drives. This study designs a hybrid, high-performance ac/ac power converter for high power applications, based on a high-power load commutated inverter and a mediumpower voltage source inverter. Natural commutation of the load commutated inverter is actively controlled by the voltage source inverter. In addition, the developed hybrid system ensures sinusoidal output current/voltage waveforms and fast dynamic response in high power areas. A new topology and control scheme for a six-step current source inverter is proposed. The proposed topology utilizes a small voltage source inverter, to turn off main thyristor switches, transfer reactive load energy, and limit peak voltages across loads. The proposed topology maximizes benefits of the constituent converters: highpower handling capability of large thyristor-based current source inverters as well as fast and easy control of small voltage source inverters. This study analyzes, compares, and evaluates two topologies for unity power factor and multiple ac/ac power conversions. Theoretical analyses and comparisons of the two topologies, grounded on mathematical approaches, are presented from the standpoint of converter kVA ratings, dc-link voltage requirements, switch ratings, semiconductor losses, and reactive component sizes. Analysis, simulation, and experimental results are detailed for each proposed topology.

Kwak, Sangshin

2006-05-01T23:59:59.000Z

173

Microfabricated ion frequency standard  

DOE Patents (OSTI)

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.

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

174

AC Loss Measurements with a Cryocooled Sample  

SciTech Connect

A new cryostat cooled by a closed-cycle Cryomech GB-37 cryocooler for superconductor measurements at temperatures down to 20 K is described. The sample is conductively coupled to the cold stage so as to minimize vibration and thermal stresses. AC losses have been measured calorimetrically in several HTSC coils that have been wound to simulate sub-scale transformer winding pairs. Stable temperatures down to 20 K were reached on these coils, allowing measurements at practical levels of ac current and I{sub c}. By using short ac current pulses, losses on individual turns could be resolved. Results are reported mainly to showcase the apparatus, measurement procedure and analytical approach.

Schwenterly, S.W.

2001-02-15T23:59:59.000Z

175

VARIABLE TIME DELAY MEANS  

DOE Patents (OSTI)

An electrically variable time delay line is described which may be readily controlled simuitaneously with variable impedance matching means coupied thereto such that reflections are prevented. Broadly, the delay line includes a signal winding about a magnetic core whose permeability is electrically variable. Inasmuch as the inductance of the line varies directly with the permeability, the time delay and characteristic impedance of the line both vary as the square root of the permeability. Consequently, impedance matching means may be varied similariy and simultaneously w:th the electrically variable permeability to match the line impedance over the entire range of time delay whereby reflections are prevented.

Clemensen, R.E.

1959-11-01T23:59:59.000Z

176

Variability in Measured Space Temperatures in 60 Homes  

NLE Websites -- All DOE Office Websites (Extended Search)

Variability in Measured Space Variability in Measured Space Temperatures in 60 Homes David Roberts National Renewable Energy Laboratory Kerylyn Lay EnerNOC (formerly of the National Renewable Energy Laboratory) Technical Report NREL/TP-5500-58059 March 2013 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National Renewable Energy Laboratory 15013 Denver West Parkway Golden, Colorado 80401 303-275-3000 * www.nrel.gov Contract No. DE-AC36-08GO28308 Variability in Measured Space Temperatures in 60 Homes David Roberts National Renewable Energy Laboratory Kerylyn Lay EnerNOC (formerly of the National Renewable Energy Laboratory)

177

Graphene Frequency Multipliers  

E-Print Network (OSTI)

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 ...

Wang, Han

178

High frequency breakdown voltage  

SciTech Connect

This report contains information about the effect of frequency on the breakdown voltage of an air gap at standard pressure and temperature, 76 mm Hg and O{degrees}C, respectively. The frequencies of interest are 47 MHz and 60 MHz. Additionally, the breakdown in vacuum is briefly considered. The breakdown mechanism is explained on the basis of collision and ionization. The presence of the positive ions produced by ionization enhances the field in the gap, and thus determines the breakdown. When a low-frequency voltage is applied across the gap, the breakdown mechanism is the same as that caused by the DC or static voltage. However, when the frequency exceeds the first critical value f{sub c}, the positive ions are trapped in the gap, increasing the field considerably. This makes the breakdown occur earlier; in other words, the breakdown voltage is lowered. As the frequency increases two decades or more, the second critical frequency, f{sub ce}, is reached. This time the electrons start being trapped in the gap. Those electrons that travel multiple times across the gap before reaching the positive electrode result in an enormous number of electrons and positive ions being present in the gap. The result is a further decrease of the breakdown voltage. However, increasing the frequency does not decrease the breakdown voltage correspondingly. In fact, the associated breakdown field intensity is almost constant (about 29 kV/cm).The reason is that the recombination rate increases and counterbalances the production rate, thus reducing the effect of the positive ions` concentration in the gap. The theory of collision and ionization does not apply to the breakdown in vacuum. It seems that the breakdown in vacuum is primarily determined by the irregularities on the surfaces of the electrodes. Therefore, the effect of frequency on the breakdown, if any, is of secondary importance.

Chu, Thanh Duy

1992-03-01T23:59:59.000Z

179

Rapid Oscillations in Cataclysmic Variables  

E-Print Network (OSTI)

I give an overview of the rich phenomenology of dwarf nova oscillations (DNOs) and Quasi-periodic Oscillations (QPOs) observed in cataclysmic variable stars (CVs). The favoured interpretation of these rapid brightness modulations (3 - >1000 s time scales) is that they are magnetic in nature - magnetically channelled accretion from the inner accretion disc for DNOs and possible magnetically excited travelling waves in the disc for QPOs. There is increasing evidence for the magnetic aspects, which extend to lower field the well known properties of strong field (polars) and intermediate strength field (intermediate polars) CVs. The result is that almost all CVs show the presence of magnetic fields on their white dwarf primaries - though for many the intrinsic field may be locally enhanced by the accretion process itself. There are many parallel behaviours with the QPOs seen in X-Ray binaries, with high and low frequency X-Ray QPOs resembling respectively the DNOs and QPOs in CVs.

Brian Warner

2003-12-06T23:59:59.000Z

180

AOCS Official Method Ac 4-91  

Science Conference Proceedings (OSTI)

Catalyst AOCS Official Method Ac 4-91 Methods Methods and Analyses Analytical Chemistry Methods Downloads DEFINITION This method determines total nitrogen content and protein as 6.25 times the nitrogen content o

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

AOCS Official Method Ac 3-44  

Science Conference Proceedings (OSTI)

Oil AOCS Official Method Ac 3-44 Methods Methods and Analyses Analytical Chemistry Methods Downloads DEFINITION This method determines the substances extracted from ground soybean seeds by petroleum ether under

182

AOCS Official Method Ac 5-41  

Science Conference Proceedings (OSTI)

Free Fatty Acids AOCS Official Method Ac 5-41 Methods Methods and Analyses Analytical Chemistry Methods Downloads DEFINITION This method determines the free fatty acids in oil removed from the seed by petroleum

183

AOCS Official Method Ac 2-41  

Science Conference Proceedings (OSTI)

Moisture and Volatile Matter AOCS Official Method Ac 2-41 Methods Methods and Analyses Analytical Chemistry Methods Downloads DEFINITION This method determines the moisture and any material that is volatile unde

184

Optimal Filtering of AC Output Anemometers  

Science Conference Proceedings (OSTI)

The output of pulsed and AC output anemometers suffer from discretization noise when such anemometers are sampled at fast rates (>1 Hz). This paper describes the construction of an optimal filter designed to reduce this noise. By comparing the ...

J. C. Barnard; L. L. Wendell; V. R. Morris

1998-12-01T23:59:59.000Z

185

Winans of XSD Elected to ACS Fellowship  

NLE Websites -- All DOE Office Websites (Extended Search)

2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed Winans of XSD Elected to ACS Fellowship JULY 8, 2009 Bookmark and Share Randy Winans Randall E. Winans, Chemical and...

186

AC distribution system for TFTR pulsed loads  

DOE Green Energy (OSTI)

This paper outlines the AC distribution system associated with the Tokamak Fusion Test Reactor and discusses the significant areas related to design, protection, and equipment selection, particularly where there is a departure from normal utility and industrial applications.

Carroll, R.F.; Ramakrishnan, S.; Lemmon, G.N.; Moo, W.I.

1977-01-01T23:59:59.000Z

187

Estimated Global Hydrographic Variability  

Science Conference Proceedings (OSTI)

An estimate is made of the three-dimensional global oceanic temperature and salinity variability, omitting the seasonal cycle, both as a major descriptive element of the ocean circulation and for use in the error estimates of state estimation. ...

Gaël Forget; Carl Wunsch

2007-08-01T23:59:59.000Z

188

Understanding Biomass Feedstock Variability  

SciTech Connect

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.

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

2013-01-01T23:59:59.000Z

189

Why inverse document frequency?  

Science Conference Proceedings (OSTI)

Inverse Document Frequency (IDF) is a popular measure of a word's importance. The IDF invariably appears in a host of heuristic measures used in information retrieval. However, so far the IDF has itself been a heuristic. In this paper, we show IDF to ...

Kishore Papineni

2001-06-01T23:59:59.000Z

190

Grid regulation services for energy storage devices based on grid frequency  

DOE Patents (OSTI)

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).

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

2013-07-02T23:59:59.000Z

191

Three phase AC motor controller  

DOE Patents (OSTI)

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.

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

192

Magnetostrictive materials and method for improving AC characteristics in same  

DOE Patents (OSTI)

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.

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

2001-08-14T23:59:59.000Z

193

7AC Technologies, Inc. | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

7AC 7AC Technologies, Inc. America's Next Top Energy Innovator Challenge 498 likes 7AC Technologies, Inc. National Renewable Energy Laboratory Air conditioning is a very large contributor to U.S. and world energy consumption. Heating and cooling costs for commercial and industrial buildings exceed 25 percent of U.S. primary energy consumption (cooling alone accounts for 4.5 Quads out of 40 Quads) and typically accounts for almost half of a building's operating costs. Air conditioning is also a significant cause of grid instability with cycling compressor motors turning on and off, and causing load issues on hot summer days. Conventional air conditioners improve efficiency only marginally every year and retrofitting older rooftop units does not result in significant energy

194

7AC Technologies, Inc. | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

7AC 7AC Technologies, Inc. America's Next Top Energy Innovator Challenge 498 likes 7AC Technologies, Inc. National Renewable Energy Laboratory Air conditioning is a very large contributor to U.S. and world energy consumption. Heating and cooling costs for commercial and industrial buildings exceed 25 percent of U.S. primary energy consumption (cooling alone accounts for 4.5 Quads out of 40 Quads) and typically accounts for almost half of a building's operating costs. Air conditioning is also a significant cause of grid instability with cycling compressor motors turning on and off, and causing load issues on hot summer days. Conventional air conditioners improve efficiency only marginally every year and retrofitting older rooftop units does not result in significant energy

195

7AC Technologies, Inc. | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

7AC 7AC Technologies, Inc. America's Next Top Energy Innovator Challenge 498 likes 7AC Technologies, Inc. National Renewable Energy Laboratory Air conditioning is a very large contributor to U.S. and world energy consumption. Heating and cooling costs for commercial and industrial buildings exceed 25 percent of U.S. primary energy consumption (cooling alone accounts for 4.5 Quads out of 40 Quads) and typically accounts for almost half of a building's operating costs. Air conditioning is also a significant cause of grid instability with cycling compressor motors turning on and off, and causing load issues on hot summer days. Conventional air conditioners improve efficiency only marginally every year and retrofitting older rooftop units does not result in significant energy

196

Princeton Plasma Physics Lab - AC power  

NLE Websites -- All DOE Office Websites (Extended Search)

ac-power The electricity that runs the ac-power The electricity that runs the Laboratory's experiments and facilities. "AC" stands for the alternating current that comes from large power stations. The term compares with "DC," for "direct current," which comes from sources like batteries. en Offshore Wind and Vehicle to Grid Power http://www.pppl.gov/events/offshore-wind-and-vehicle-grid-power

Professor Willett Kempton, of the University of Delaware, presents "Offshore Wind and Vehicle to Grid Power" as part of the Andlinger Center's 2013-2014 Highlight Seminar Series.

197

High frequency reference electrode  

DOE Patents (OSTI)

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.

Kronberg, J.W.

1991-03-05T23:59:59.000Z

198

High frequency reference electrode  

DOE Patents (OSTI)

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.

Kronberg, J.W.

1994-05-31T23:59:59.000Z

199

High frequency reference electrode  

DOE Patents (OSTI)

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.

Kronberg, James W. (Aiken, SC)

1994-01-01T23:59:59.000Z

200

Georeactor Variability and Integrity  

E-Print Network (OSTI)

As a deep-Earth energy source, the planetocentric nuclear-fission georeactor concept is on a more secure scientific footing than the previous idea related to the assumed growth of the inner core. Unlike previously considered deep-Earth energy sources, which are essentially constant on a human time-scale, variability in nuclear fission reactors can arise from changes in composition and/or position of fuel, moderators, and neutron absorbers. Tantalizing circumstantial evidence invites inquiry into the possibility of short-term planetocentric nuclear fission reactor variability. This brief communication emphasizes the importance of scientific integrity and highlights the possibility of variable georeactor power output so that these might be borne in mind in future investigations, especially those related to the Earth's heat flux.

J. Marvin Herndon

2005-10-04T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Georeactor Variability and Integrity  

E-Print Network (OSTI)

As a deep-Earth energy source, the planetocentric nuclear-fission georeactor concept is on a more secure scientific footing than the previous idea related to the assumed growth of the inner core. Unlike previously considered deep-Earth energy sources, which are essentially constant on a human time-scale, variability in nuclear fission reactors can arise from changes in composition and/or position of fuel, moderators, and neutron absorbers. Tantalizing circumstantial evidence invites inquiry into the possibility of short-term planetocentric nuclear fission reactor variability. This brief communication emphasizes the importance of scientific integrity and highlights the possibility of variable georeactor power output so that these might be borne in mind in future investigations, especially those related to the Earth's heat flux.

Herndon, J M

2005-01-01T23:59:59.000Z

202

AC H I E V I NG  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

AC AC H I E V I NG The Department's strategic plan flow is highlighted in the cascade below beginning with the mission statement which flows to the strategic themes. The strategic themes connect to the broader strategic goals and are linked to the annual performance goals in the performance budget through the multi-year program plans. The multi-year program plans allow DOE to strategize over a five-year period how each program will implement the strategic goals of the Department. Annual performance goals and assessment of performance against prior-year

203

Observational study on variability between biobanks in the estimation of DNA concentration  

E-Print Network (OSTI)

ral ssBioMed CentBMC Research Notes Open AcceShort Report Observational study on variability between biobanks in the estimation of DNA concentration Jay Brown1, Alexander N Donev2, Charalampos Aslanidis3, Pippa Bracegirdle4, Katherine P Dixon1... National Genetics Reference Laboratory, Central Manchester University Hospitals, Manchester, UK Email: Jay Brown - Jay.Brown@cmmc.nhs.uk; Alexander N Donev - A.N.Donev@manchester.ac.uk; Charalampos Aslanidis - charalampos...

Brown, Jay; Donev, Alexander N; Aslanidis, Charalampos; Bracegirdle, Pippa; Dixon, Katherine P; Foedinger, Manuela; Gwilliam, Rhian; Hardy, Matthew; Illig, Thomas; Ke, Xiayi; Krinka, Dagni; Lagerberg, Camilla; Laiho, Paivi; Lewis, David H; McArdle, Wendy; Jones, Richard W; Patton, Simon; Ring, Susan M; Schmitz, Gerd; Stevens, Helen; Tybring, Gunnel; Wichmann, H Erich; Ollier, William E R; Yuille, Martin A

2009-10-13T23:59:59.000Z

204

Self isolating high frequency saturable reactor  

DOE Patents (OSTI)

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.

Moore, James A. (Powell, TN)

1998-06-23T23:59:59.000Z

205

Modeling 18° Water Variability  

Science Conference Proceedings (OSTI)

Variability of 18° Water formation is investigated with an isopycnic-coordinate model of the North Atlantic. A 30-year spinup integration is used as a “control” experiment in which the upper water column in the Sargasso Sea is shown to be in ...

Robert Marsh; Adrian L. New

1996-06-01T23:59:59.000Z

206

Laser-frequency multiplication  

SciTech Connect

A high quality mode locked pulse train was obtained at 9.55 micrometers, the CO2 wavelength chosen for frequency doubling into the atmospheric window at 4.8 micrometers. The pulse train consists of a 3 micro sec burst of 1.5 nsec pulses separated by 40 nsec, in a TEM(00) mode and with a total energy of 100 mJ. The pulse intensity without focussing is about 3 MW/sq.cm., already quite close to the target intensity of 10 MW/sq.cm. for frequency doubling in a AgGaSe2 crystal. The mode-locked train is obtained by intracavity modulation at 12.5 MHz using a germanium crystal driven with a power of about 30 Watts. Line selection is achieved firstly by the use of a 0.92 mm thick CaF2 plate at the Brewster angle within the cavity, which completely suppresses 10.6 micrometer band radiation. Secondly, a particular rotational line, the P20 at 9.55 micrometers, is selected by the injection of a continuous beam is mode-matched to the pulsed laser cavity using a long focal length lens, and for best line-locking it is necessary to fine tune the length of the pulsed laser resonator. Injection causes substantial depression of the gain switched spike.

Not Available

1991-11-01T23:59:59.000Z

207

Variable percentage sampler  

DOE Patents (OSTI)

A remotely operable sampler is provided for obtaining variable percentage samples of nuclear fuel particles and the like for analyses. The sampler has a rotating cup for a sample collection chamber designed so that the effective size of the sample inlet opening to the cup varies with rotational speed. Samples of a desired size are withdrawn from a flowing stream of particles without a deterrent to the flow of remaining particles.

Miller, Jr., William H. (Knoxville, TN)

1976-01-01T23:59:59.000Z

208

Variable laser attenuator  

DOE Patents (OSTI)

The disclosure relates to low loss, high power variable attenuators comprising one or more transmissive and/or reflective multilayer dielectric filters. The attenuator is particularly suitable to use with unpolarized lasers such as excimer lasers. Beam attenuation is a function of beam polarization and the angle of incidence between the beam and the filter and is controlled by adjusting the angle of incidence the beam makes to the filter or filters. Filters are selected in accordance with beam wavelength. 9 figs.

Foltyn, S.R.

1987-05-29T23:59:59.000Z

209

Variable laser attenuator  

SciTech Connect

The disclosure relates to low loss, high power variable attenuators comprng one or more transmissive and/or reflective multilayer dielectric filters. The attenuator is particularly suitable to use with unpolarized lasers such as excimer lasers. Beam attenuation is a function of beam polarization and the angle of incidence between the beam and the filter and is controlled by adjusting the angle of incidence the beam makes to the filter or filters. Filters are selected in accordance with beam wavelength.

Foltyn, Stephen R. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

210

Solar-type Variables  

E-Print Network (OSTI)

The rich acoustic oscillation spectrum in solar-type variables make these stars particularly interesting for studying fluid-dynamical aspects of the stellar interior. I present a summary of the properties of solar-like oscillations, how they are excited and damped and discuss some of the recent progress in using asteroseismic diagnostic techniques for analysing low-degree acoustic modes. Also the effects of stellar-cycle variations in low-mass main-sequence stars are addressed.

Houdek, Gunter

2009-01-01T23:59:59.000Z

211

Errors in all variables  

SciTech Connect

We present a thorough derivation of the posterior for the straight line fit employing the hyper-plane prior. For the example of the parabola we enlarge the scope to nonlinear problems, however simplify it to be solved resembling the straight line solution. Finally we come to the problem of determining the exponents of a scaling law, where in logarithmic form the scaling exponents are linear coefficients of logarithmic variables.

Preuss, R.; Dose, V. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)

2005-11-23T23:59:59.000Z

212

Long-Term Wind Power Variability  

DOE Green Energy (OSTI)

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.

Wan, Y. H.

2012-01-01T23:59:59.000Z

213

Search for Spatial Variability in the Solar Acoustic Spectrum  

E-Print Network (OSTI)

Motivated by the various examples of spatial variability in the power of the acoustic spectrum, we attempted to look for spatial variability in the peak frequency of the spectrum. However, the determination of this peak frequency on a spatial scale of a single pixel (8 arc seconds for the GONG data) is limited by the stochastic variations in the power spectrum presumably caused by the stochastic nature of the excitation process. Averaging over a large number of spectra (100 spectra from a 10 $\\times$ 10 pixels area) produced stabler spectra. The peak frequencies of 130 such locations were found to be distributed with a FWHM of about 130 $\\mu$Hz. A map of the spatial variation of this peak frequency did not show any strong feature with statistically significant deviation from the mean of the distribution. Likewise, the scatter in the peak frequencies masked the detection of magnetic field induced changes in the peak frequency. On a much larger scale, the N latitudes showed a slightly lower value of the peak frequency as compared to the S latitudes, although the difference (25 $\\mu$Hz) is barely larger than the {\\it rms} spread (20 $\\mu$Hz).

P. Venkatakrishnan; Brajesh Kumar; S. C. Tripathy

2001-05-22T23:59:59.000Z

214

SEARCH FOR SPATIAL VARIABILITY IN THE SOLAR ACOUSTIC SPECTRUM  

E-Print Network (OSTI)

Abstract. Motivated by the various examples of spatial variability in the power of the acoustic spectrum, we attempted to look for spatial variability in the peak frequency of the spectrum. However, the determination of this peak frequency on a spatial scale of a single pixel (8 arc seconds for the GONG data) is limited by the stochastic variations in the power spectrum presumably caused by the stochastic nature of the excitation process. Averaging over a large number of spectra (100 spectra from a 10 × 10 pixels area) produced stabler spectra. The peak frequencies of 130 such locations were found to be distributed with a FWHM of about 130 µHz. A map of the spatial variation of this peak frequency did not show any strong feature with statistically significant deviation from the mean of the distribution. Likewise, the scatter in the peak frequencies masked the detection of magnetic field induced changes in the peak frequency. On a much larger scale, the N latitudes showed a slightly lower value of the peak frequency as compared to the S latitudes, although the difference (25 µHz) is barely larger than the rms spread (20 µHz). 1.

P. Venkatakrishnan; Brajesh Kumar; S. C. Tripathy

2001-01-01T23:59:59.000Z

215

Animation of JILA Frequency Comb Spectroscopy Technique  

Science Conference Proceedings (OSTI)

Animation of JILA Frequency Comb Spectroscopy Technique. The new JILA "frequency comb spectroscopy" technique ...

2012-08-17T23:59:59.000Z

216

Radio frequency coaxial feedthrough  

DOE Patents (OSTI)

An improved radio frequency coaxial transmission line vacuum feed-through provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflections from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits voltage and power handling capabilities of a feedthrough.

Owens, Thomas L. (Kingston, TN)

1989-01-17T23:59:59.000Z

217

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmonic 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} {center_dot} 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.

Ebbers, C.A.; Davis, L.E.; Webb, M.

1990-10-16T23:59:59.000Z

218

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmonic 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} {center dot} 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.

Ebbers, C.A.; Davis, L.E.; Webb, M.

1990-10-16T23:59:59.000Z

219

Frequency mixing crystal  

DOE Patents (OSTI)

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.

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

1992-01-01T23:59:59.000Z

220

Modeling the High-Frequency Component of Arctic Sea Ice Drift and Deformation  

Science Conference Proceedings (OSTI)

Buoy observations of sea ice drift show that sea ice motion and deformation contain substantial high-frequency variability at subdaily timescales. However, numerical simulations of the sea ice dynamics normally do not include processes on such ...

Petra Heil; William D. Hibler III

2002-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Cross-Frequency Coupling, Skewness, and Blocking in the Northern Hemisphere Winter Circulation  

Science Conference Proceedings (OSTI)

Variability in daily wintertime [December–February (DJF)] 500-hPa heights on low [L: (6 day)?1] frequencies is examined using 40-yr ECMWF Re-Analysis (ERA-40) data. Leading EOFs of L ...

Kevin J. Rennert; John M. Wallace

2009-11-01T23:59:59.000Z

222

Decadal Variability in a Simplified Wind-Driven Ocean Model  

Science Conference Proceedings (OSTI)

The impact of an unsteady wind forcing on oceanic low-frequency variability is conceptually studied using a reduced-gravity shallow-water model. A time-averaged wind forcing and a simple ocean–atmosphere coupling is completed by a stochastic ...

Philip Sura; Frank Lunkeit; Klaus Fraedrich

2000-08-01T23:59:59.000Z

223

Annual Cycle and Variability of the North Brazil Current  

Science Conference Proceedings (OSTI)

Current meter observations from an array of three subsurface moorings located on the Brazil continental slope near 4°N are used to describe the annual cycle and low-frequency variability of the North Brazil Current (NBC). The moored array was ...

W. E. Johns; T. N. Lee; R. C. Beardsley; J. Candela; R. Limeburner; B. Castro

1998-01-01T23:59:59.000Z

224

Jets with Variable R  

E-Print Network (OSTI)

We introduce a new class of jet algorithms designed to return conical jets with a variable Delta R radius. A specific example, in which Delta R scales as 1/pT, proves particularly useful in capturing the kinematic features of a wide variety of hard scattering processes. We implement this Delta R scaling in a sequential recombination algorithm and test it by reconstructing resonance masses and kinematic endpoints. These test cases show 10-20% improvements in signal efficiency compared to fixed Delta R algorithms. We also comment on cuts useful in reducing continuum jet backgrounds.

David Krohn; Jesse Thaler; Lian-Tao Wang

2009-03-02T23:59:59.000Z

225

Joint Spatiotemporal Variability of Global Sea Surface Temperatures and Global Palmer Drought Severity Index Values  

Science Conference Proceedings (OSTI)

Dominant modes of individual and joint variability in global sea surface temperatures (SST) and global Palmer drought severity index (PDSI) values for the twentieth century are identified through a multivariate frequency domain singular value ...

Somkiat Apipattanavis; Gregory J. McCabe; Balaji Rajagopalan; Subhrendu Gangopadhyay

2009-12-01T23:59:59.000Z

226

Monitoring North Pacific Heat Content Variability: An Indicator of Fish Quantity?  

Science Conference Proceedings (OSTI)

Fields of modeled sea surface heights and temperatures are used to develop an algorithm to monitor the low-frequency heat content variability of the North Pacific's midlatitudes associated with regime shifts in the circulation patterns of the ...

R. Tokmakian

2003-11-01T23:59:59.000Z

227

Subseasonal and Interannual Temperature Variability in Relation to Extreme Temperature Occurrence over East Asia  

Science Conference Proceedings (OSTI)

This study investigates interannual variability in the frequency of occurrence of daily surface air temperature (SAT) extremes over East Asia in summer and winter between 1979 and 2009. We examine the dominant seasonal SAT patterns, as obtained ...

Hiroyuki Ito; Nathaniel C. Johnson; Shang-Ping Xie

228

Interdecadal Trend and ENSO-Related Interannual Variability in Southern Hemisphere Blocking  

Science Conference Proceedings (OSTI)

The interdecadal trend and ENSO-related interannual variability in the frequency and intensity of atmospheric blocking in the Southern Hemisphere are analyzed by a statistical model that takes account of serial correlation in the datasets. ...

Li Dong; Timothy J. Vogelsang; Stephen J. Colucci

2008-06-01T23:59:59.000Z

229

Secular Changes of Annual and Interannual Variability in the Tropics during the Past Century  

Science Conference Proceedings (OSTI)

Wavelet transforms, which can unfold signals in both time and frequency domains, are used to analyze the Comprehensive Ocean and Atmospheric Data Sets for the period 1870–1988. The focus is on secular changes in the interannual variability and ...

Daifang Gu; S. G. H. Philander

1995-04-01T23:59:59.000Z

230

Aspects of the Tidal Variability Observed on the Southern California Continental Shelf  

Science Conference Proceedings (OSTI)

Observations of the current and temperature field from the southern California continental shelf are analyzed in a frequency band (0.6–6 cpd) dominated by tidal fluctuations. The seasonal variability of the temperature and horizontal velocity ...

A. Bratkovich

1985-03-01T23:59:59.000Z

231

Satellite-Derived Interannual Variability of West African Rainfall during 1983?88  

Science Conference Proceedings (OSTI)

Two satellite algorithms for rain estimation are used to study the interannual variability of West African rainfall during contrasting years of the period 1983?88. The first algorithm uses a frequency of occurrence index quantifying the number of ...

Mamoudou B. Ba; Robert Frouin; Sharon E. Nicholson

1995-02-01T23:59:59.000Z

232

Estimating Central Equatorial Pacific SST Variability over the Past Millennium. Part I: Methodology and Validation  

Science Conference Proceedings (OSTI)

Constraining the low-frequency (LF) behavior of general circulation models (GCMs) requires reliable observational estimates of LF variability. This two-part paper presents multiproxy reconstructions of Nińo-3.4 sea surface temperature over the ...

Julien Emile-Geay; Kimberly M. Cobb; Michael E. Mann; Andrew T. Wittenberg

2013-04-01T23:59:59.000Z

233

Interannual (ENSO) and Interdecadal (ENSO-like) Variability in the Southern Hemisphere Tropospheric Circulation  

Science Conference Proceedings (OSTI)

Recent work has identified variability in the Pacific Ocean SST with a structure qualitatively similar to ENSO, but at lower frequencies than ENSO. Zhang et al. have documented the atmospheric circulation anomalies in the Tropics and Northern ...

RenéD. Garreaud; David S. Battisti

1999-07-01T23:59:59.000Z

234

Sensible and Latent Cooling Load Control Using Centrally-Ducted, Variable-Capacity Space Conditioning Systems in Low Sensible Load Environments  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Sensible and Latent Cooling Load Control Using Centrally-Ducted, Variable-Capacity Space Conditioning Systems in Low Sensible Load Environments James Cummings BA-PIRC; Florida Solar Energy Center Presented at BA Summer Meeting, July 26, 2012 The gist of my message * Fixed capacity AC systems generally provide good RH control in typical residences. * In low-load homes, they may be less effective in achieving good RH control. * On the other hand, variable capacity AC systems have several characteristics which can provide improved RH control in homes. - Both Nordyne and Carrier have variable capacity units, varying from about 40% to 100% of nominal full capacity. - What is variable capacity? -- condenser fan, compressor speed, and AHU fan speed. The gist, continued

235

Solar Irradiance Variability  

E-Print Network (OSTI)

The Sun has long been considered a constant star, to the extent that its total irradiance was termed the solar constant. It required radiometers in space to detect the small variations in solar irradiance on timescales of the solar rotation and the solar cycle. A part of the difficulty is that there are no other constant natural daytime sources to which the Sun's brightness can be compared. The discovery of solar irradiance variability rekindled a long-running discussion on how strongly the Sun affects our climate. A non-negligible influence is suggested by correlation studies between solar variability and climate indicators. The mechanism for solar irradiance variations that fits the observations best is that magnetic features at the solar surface, i.e. sunspots, faculae and the magnetic network, are responsible for almost all variations (although on short timescales convection and p-mode oscillations also contribute). In spite of significant progress important questions are still open. Thus there is a debat...

Solanki, Sami K

2012-01-01T23:59:59.000Z

236

AC-to-DC Power Transmission Line Conversion  

Science Conference Proceedings (OSTI)

System planners have grown more interest in the prospect of converting ac transmission lines to dc as transfer constraints become more severe and they increasingly recognize dc as a means to improve ac system performance. Two factors have influenced the economic case for conversion. The first is development of a new (tripole) dc configuration that allows dc to make full use of all three ac phase positions without the need for earth return. The second is the realization that converting an ac line to dc ma...

2010-11-10T23:59:59.000Z

237

Road to AC Voltage Standard Leads to Important Junction  

Science Conference Proceedings (OSTI)

Road to AC Voltage Standard Leads to Important Junction. ... Grumman in the mid-1990s.*** A number of innovations since then have led to the first ...

2013-08-13T23:59:59.000Z

238

Simultaneous distribution of AC and DC power - Energy ...  

... Alternating Current) as well as the elimination of equipment normally used to reconvert AC back to DC for components of HVAC systems, ...

239

AC vs DC Wizard Version 1.0  

Science Conference Proceedings (OSTI)

AC vs DC Wizard compares the use of HVDC to HVAC in both new and existing overhead lines and in new underground cable ...

2012-12-04T23:59:59.000Z

240

Surge Protection in Low-Voltage AC Power Circuits  

Science Conference Proceedings (OSTI)

Surge Protection in Low-Voltage AC Power Circuits: An 8-part Anthology ... converting old and yellowing papers into 21st Century electronic files, and ...

2013-05-20T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

ACTS Project N. AC040 D 8.4. Variable Quality Rendering  

E-Print Network (OSTI)

. *Type: P-public, R-restricted, L-limited, I-internal **Nature: P-Prototype, R-Report, S-Specification, T Number: A040-UCL-CS-DS-P-084.b1 Contractual Date of Delivery to the CEC: January 1st , 1998 Actual Date for the COVEN scenarios grow larger this becomes an increasingly difficult task. In this report we present some

Slater, Mel

242

IS ACTIVE REGION CORE VARIABILITY AGE DEPENDENT?  

Science Conference Proceedings (OSTI)

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.

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

243

AC Solar Inc | Open Energy Information  

Open Energy Info (EERE)

Logo: AC Solar Inc Name AC Solar Inc Address P.O. Box 128 Place Florence, Colorado Zip 81226 Sector Solar Product Solar and wind sales for residential Website http://www.acsolar.com/ Coordinates 38.381551°, -105.112265° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":38.381551,"lon":-105.112265,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

244

Climate Variability, Fish, and Fisheries  

Science Conference Proceedings (OSTI)

Fish population variability and fisheries activities are closely linked to weather and climate dynamics. While weather at sea directly affects fishing, environmental variability determines the distribution, migration, and abundance of fish. ...

P. Lehodey; J. Alheit; M. Barange; T. Baumgartner; G. Beaugrand; K. Drinkwater; J.-M. Fromentin; S. R. Hare; G. Ottersen; R. I. Perry; C. Roy; C. D. van der Lingen; F. Werner

2006-10-01T23:59:59.000Z

245

Colorado River Basin Hydroclimatic Variability  

Science Conference Proceedings (OSTI)

An analysis of annual hydroclimatic variability in the Upper Colorado River basin (UCRB) for the period of 1906–2006 was performed to understand the dominant modes of multidecadal variability. First, wavelet-based spectral analysis was employed ...

Kenneth Nowak; Martin Hoerling; Balaji Rajagopalan; Edith Zagona

2012-06-01T23:59:59.000Z

246

Optical frequency combs: From frequency metrology to optical ...  

Science Conference Proceedings (OSTI)

... and to dis- tribute the load of the ... measurements of frequency ratios (ie, energy ratios), and ... accuracy or stability versus power consumption, cost, or ...

2004-01-27T23:59:59.000Z

247

ac-driven atomic quantum motor  

E-Print Network (OSTI)

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.

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

2009-02-03T23:59:59.000Z

248

ac-driven atomic quantum motor  

E-Print Network (OSTI)

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.

Ponomarev, A V; Hänggi, P

2009-01-01T23:59:59.000Z

249

Scalable analysis of variable software  

Science Conference Proceedings (OSTI)

The advent of variability management and generator technology enables users to derive individual variants from a variable code base based on a selection of desired configuration options. This approach gives rise to the generation of possibly billions ... Keywords: C Preprocessor, Liveness Analysis, Software Product Lines, Type Checking, Variability-aware Analysis

Jörg Liebig; Alexander von Rhein; Christian Kästner; Sven Apel; Jens Dörre; Christian Lengauer

2013-08-01T23:59:59.000Z

250

Variability within Modeling Language Definitions  

Science Conference Proceedings (OSTI)

We present a taxonomy of the variability mechanisms offered by modeling languages. The definition of a formal language encompasses a syntax and a semantic domain as well as the mapping that relates them, thus language variabilities are classified according ... Keywords: Modeling languages, UML, formal semantics, variability

María Victoria Cengarle; Hans Grönniger; Bernhard Rumpe

2009-10-01T23:59:59.000Z

251

Symmetrization Of Binary Random Variables  

E-Print Network (OSTI)

A random variable Y is called an independent symmetrizer of a given random variable X if (a) it is independent of X and (b) the distribution of X Y is symmetric about 0. In cases where the distribution of X is symmetric about its mean, it is easy to see that the constant random variable Y is a minimum-variance independent symmetrizer. Taking

Abram Kagan; Colin Mallows; Larry Shepp; Robert J. Vanderbei; Yehuda Vardi

1999-01-01T23:59:59.000Z

252

The Vibration Frequencies of Wind Turbine Steel Tower by Transfer Matrix Method  

Science Conference Proceedings (OSTI)

Large-scale wind turbine structure is simplified as a slender cantilever beam with variable sections subject to complex loads configuration. An analytical procedure to estimate not only natural frequencies but also vibration mode shapes of thin-walled ... Keywords: horizontal axis wind turbine tower, natural frequency, transfer matrix method, free vibration

Wang Meng; Wang Zhangqi

2011-01-01T23:59:59.000Z

253

Radio Frequency Engineering, MDE, Accelerator Operations and...  

NLE Websites -- All DOE Office Websites (Extended Search)

Home Teams Low-Level Radio Frequency Magnet Power Supplies, Pulsed Power Radio Frequency, High Voltage Technologies Radio Frequency Operations CONTACTS Group Leader Dan Rees Deputy...

254

Frequency Control Performance Measurement and Requirements  

E-Print Network (OSTI)

power systems operations could significantly influence primary frequency control.power system operations could not significantly influence primary frequency control.power system operations. Determination of frequency control

Illian, Howard F.

2011-01-01T23:59:59.000Z

255

Infrastructure Failure - Types and Frequency  

U.S. Energy Information Administration (EIA)

Infrastructure Failure - Types and Frequency. Small events that have no impact on supplies Events that require supply/demand responses Events that result in a ...

256

Time and Frequency Division Homepage  

Science Conference Proceedings (OSTI)

... Controlled ClocksTelephone TimeDivision HistoryFrequently Asked Questions (FAQ)Time and Frequency from A to Z: An illustrated glossaryA Walk ...

2013-12-27T23:59:59.000Z

257

Dynamic frequency allocation in fractional frequency reused OFDMA networks  

Science Conference Proceedings (OSTI)

This paper proposes a dynamic fractional frequency reused cell architecture that simplifies the problem of subcarrier allocation with frequency reuse in multicell OFDMA networks. The architecture divides the cell surface into two overlapping geographical ... Keywords: 3G, cellular networks, cross-layer adaptation, data networks, mobile communication systems, opportunistic scheduling, wireless communication

Syed Hussain Ali; Victor C. M. Leung

2009-08-01T23:59:59.000Z

258

Measurement and Modeling of Solar and PV Output Variability: Preprint  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Measurement and Modeling of Measurement and Modeling of Solar and PV Output Variability Preprint M. Sengupta To be presented at SOLAR 2011 Raleigh, North Carolina May 17-21, 2011 Conference Paper NREL/CP-5500-51105 April 2011 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (Alliance), a contractor of the US Government under Contract No. DE-AC36-08GO28308. Accordingly, the US Government and Alliance retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty,

259

Demand Response and Variable Generation Integration Scoping Study  

NLE Websites -- All DOE Office Websites (Extended Search)

The Impact of City-level Permitting The Impact of City-level Permitting Processes on Residential PV Installation Prices and Development Times An Empirical Analysis of Solar Systems in California Cities Ryan Wiser and CG Dong Lawrence Berkeley National Laboratory April 2013 This analysis was funded by the Solar Energy Technologies Office, Office of Energy Efficiency and Renewable Energy of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 Energy Analysis Department  Electricity Markets and Policy Group Presentation Overview * Questions and Objective * Literature Review * Data Sources and Processing * Variable Description and Summary * Regression Analysis Results * Interpretation and Predictions * Conclusions * Possible Future Extensions 2 Energy Analysis Department  Electricity Markets and Policy Group

260

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

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Heart Rate Variability in Mice with Coronary Heart Disease  

E-Print Network (OSTI)

Heart rate variability (HRV), the beat-to-beat fluctuation of the heart rate, is a noninvasive test that measures the autonomic regulation of the heart. Assessment of HRV has been shown to predict the risk of mortality in patients after an acute myocardial infarction. Recently, the Krieger lab at MIT developed genetically engineered double knockout (dKO) mice that develop coronary artery disease accompanied by spontaneous myocardial infarctions and die at a very young age. This thesis investigated whether HRV could function as a prognostic indicator in the dKO mouse. A novel method for estimating physiological state of the mouse from the electrocardiogram using an innovative activity index was developed in order to compare HRV variables at different times while controlling for physiologic state. Traditional time and frequency domain variables were used to assess the prognostic power of HRV. Results have shown that none of the HRV variables were helpful in predicting

Laurence Zapanta; Roger G. Mark

2005-01-01T23:59:59.000Z

262

AC impedance analysis of Au/porous silicon contacts  

Science Conference Proceedings (OSTI)

In this paper we present the AC impedance analysis of Au/porous silicon contacts in order to investigate their conduction mechanisms. The porous silicon layer was obtained by electrochemical etching of the p-Si wafer. The measurements were made between ... Keywords: AC electrical conductivity, Electrical equivalent circuit, Porous silicon

F. Fonthal; T. Trifonov; A. Rodriguez; L. F. Marsal; J. Pallarčs

2006-11-01T23:59:59.000Z

263

Electrostatic coalescence system with independent AC and DC hydrophilic electrodes  

DOE Patents (OSTI)

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.

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

1981-01-01T23:59:59.000Z

264

Measurement of coupling resonance driving terms with the AC dipole  

Science Conference Proceedings (OSTI)

Resonance driving terms for linear coupled betatron motion in a synchrotron ring can be determined from corresponding spectral lines of an excited coherent beam motion. An AC dipole is one of instruments to excite such a motion. When a coherent motion is excited with an AC dipole, measured Courant-Snyder parameters and betatron phase advance have apparent modulations, as if there is an additional quadrupole field at the location of the AC dipole. Hence, measurements of these parameters using the AC dipole require a proper interpretation of observed quantities. The situation is similar in measurements of resonance driving terms using the AC dipole. In this note, we derive an expression of coupled betatron motion excited with two AC dipoles in presence of skew quadrupole fields, discuss an impact of this quadrupole like effect of the AC dipole on a measurement of coupling resonance driving terms, and present an analytical method to determine the coupling resonance driving terms from quantities observed using the AC dipole.

Miyamoto, R.

2010-10-01T23:59:59.000Z

265

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

266

AC Losses in the New High-Temperature Superconductors  

Science Conference Proceedings (OSTI)

This report addresses the properties of high-temperature ceramic oxide superconductors in low magnetic fields. It discusses ac losses in the superconducting and normal states, the influence of anisotropy, and a database for monitoring advances in superconductivity. The ac losses of the oxide superconductors were found to be excessive.

1989-03-17T23:59:59.000Z

267

Stabilized radio-frequency quadrupole  

DOE Patents (OSTI)

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.

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

1982-09-29T23:59:59.000Z

268

Frequency Conversion of Entangled State  

E-Print Network (OSTI)

The quantum characteristics of sum-frequency process in an optical cavity with an input signal optical beam, which is a half of entangled optical beams, are analyzed. The calculated results show that the quantum properties of the signal beam can be maintained after its frequency is conversed during the intracavity nonlinear optical interaction. The frequency-conversed output signal beam is still in an entangled state with the retained other half of initial entangled beams. The resultant quantum correlation spectra and the parametric dependences of the correlations on the initial squeezing factor, the optical losses and the pump power of the sum-frequency cavity are calculated. The proposed system for the frequency conversion of entangled state can be used in quantum communication network and the calculated results can provide direct references for the design of experimental systems.

Aihong Tan; Xiaojun Jia; Changde Xie

2006-03-01T23:59:59.000Z

269

General Interest NIST Time and Frequency Publications  

Science Conference Proceedings (OSTI)

... Time and Frequency Users Manual A detailed ... Fundamentals of Time and Frequency An overview of ... Lombardi, The Mechatronics Handbook, 2001. ...

2012-01-31T23:59:59.000Z

270

High Frequency Power Modulation - TRIMET Smelters Provide ...  

Science Conference Proceedings (OSTI)

Presentation Title, High Frequency Power Modulation - TRIMET Smelters Provide Primary Control Power for Stabilizing the Frequency in the Electricity Grid.

271

Analysis and design of high frequency link power conversion systems for fuel cell power conditioning  

E-Print Network (OSTI)

In this dissertation, new high frequency link power conversion systems for the fuel cell power conditioning are proposed to improve the performance and optimize the cost, size, and weight of the power conversion systems. The first study proposes a new soft switching technique for the phase-shift controlled bi-directional dc-dc converter. The described dc-dc converter employs a low profile high frequency transformer and two active full-bridge converters for bidirectional power flow capability. The proposed new soft switching technique guarantees soft switching over wide range from no load to full load without any additional circuit components. The load range for proposed soft switching technique is analyzed by mathematical approach with equivalent circuits and verified by experiments. The second study describes a boost converter cascaded high frequency link direct dc-ac converter suitable for fuel cell power sources. A new multi-loop control for a boost converter to reduce the low frequency input current harmonics drawn from the fuel cell is proposed, and a new PWM technique for the cycloconverter at the secondary to reject the low order harmonics in the output voltages is presented. The performance of the proposed scheme is verified by the various simulations and experiments, and their trade-offs are described in detail using mathematical evaluation approach. The third study proposes a current-fed high frequency link direct dc-ac converter suitable for residential fuel cell power systems. The high frequency full-bridge inverter at the primary generates sinusoidally PWM modulated current pulses with zero current switching (ZCS), and the cycloconverter at the secondary which consists of only two bidirectional switches and output filter capacitors produces sinusoidally modulated 60Hz split single phase output voltage waveforms with near zero current switching. The active harmonic filter connected to the input terminal compensates the low order input current harmonics drawn from the fuel cell without long-term energy storage devices such as batteries and super capacitors.

Song, Yu Jin

2004-08-01T23:59:59.000Z

272

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

SciTech Connect

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.

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

1984-01-01T23:59:59.000Z

273

CDIAC Climate Data: Available Variables  

NLE Websites -- All DOE Office Websites (Extended Search)

Climate Variables Available in CDIAC Data Products Temperature Precipitation Cloudiness Sunshine Duration Snowfall and Snow Depth Atmospheric Pressure Atmospheric Moisture Surface...

274

AUTO ID FUTURE - FREQUENCY AGNOSTIC  

E-Print Network (OSTI)

Identification of information is one key to the development of intelligent decision systems of the future. Frequency agnostic automatic identification is only one step in the physical world to make physical objects identify ...

DATTA, SHOUMEN

275

Frequency regulator for synchronous generators  

DOE Patents (OSTI)

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.

Karlicek, Robert F. (1920 Camino Centroloma, Fullerton, CA 92633)

1982-01-01T23:59:59.000Z

276

Frequency regulator for synchronous generators  

DOE Patents (OSTI)

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.

Karlicek, R.F.

1982-08-10T23:59:59.000Z

277

AC versus DC distribution systems- Did we get it right?  

DOE Green Energy (OSTI)

We presently enjoy a predominantly ac electrical distribution system, the engineering basis for which was designed over 100 years ago. While ac distribution systems have served us well, we should periodically pause to assess what opportunities we have accepted or been denied by the overwhelming predominance of ac electrical power distribution systems. What opportunities could be obtained by engineering dc distribution into at least portions of our present system? What advantages of the present ac distribution system should be recognized and protected? This paper will focus on distribution within premise and low-voltage distribution systems. Specifically, we will address the conversion efficiency costs of adopting various premise ac and dc distribution system topologies. According to a simple predictive model formulated in this paper, premise residential dc distribution will incur unfavorable total conversion efficiency compared with existing ac premise distribution. However, if a residence is supplied by a fuel cell or another dc generator, the total conversion efficiency within a residential dc distribution system could be similar to, or even better than, that for ac distribution.

Hammerstrom, Donald J.

2007-06-28T23:59:59.000Z

278

Low-Frequency Modulation of Turbulent Diapycnal Mixing by Anticyclonic Eddies Inferred from the HOT Time Series  

Science Conference Proceedings (OSTI)

Profiles of potential density obtained from CTD measurements during the Hawaii Ocean Time series (HOT) program in the vicinity of the island of Oahu, Hawaii, are used to evaluate low-frequency variability of turbulent kinetic dissipation rates ...

Zhao Jing; Lixin Wu

2013-04-01T23:59:59.000Z

279

Heart Rate Variability Analysis Using Threshold of Wavelet Package Coefficients  

E-Print Network (OSTI)

In this paper, a new efficient feature extraction method based on the adaptive threshold of wavelet package coefficients is presented. This paper especially deals with the assessment of autonomic nervous system using the background variation of the signal Heart Rate Variability HRV extracted from the wavelet package coefficients. The application of a wavelet package transform allows us to obtain a time-frequency representation of the signal, which provides better insight in the frequency distribution of the signal with time. A 6 level decomposition of HRV was achieved with db4 as mother wavelet, and the above two bands LF and HF were combined in 12 specialized frequencies sub-bands obtained in wavelet package transform. Features extracted from these coefficients can efficiently represent the characteristics of the original signal. ANOVA statistical test is used for the evaluation of proposed algorithm.

Kheder, G; Massoued, M Ben; Samet, M

2009-01-01T23:59:59.000Z

280

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

DOE Patents (OSTI)

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.

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

2013-02-26T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Designing AC power grids using integer linear programming  

Science Conference Proceedings (OSTI)

Recent developments have drawn focus towards the efficient calculation of flows in AC power grids, which are difficult to solve systems of nonlinear equations. The common linearization approach leads to the well known and often used DC formulation, which ...

Arie M. C. A. Koster; Stephan Lemkens

2011-06-01T23:59:59.000Z

282

M2ACS: Multifaceted Mathematics for Complex Energy Systems Project...  

NLE Websites -- All DOE Office Websites (Extended Search)

M2ACS: Multifaceted Mathematics for Complex Energy Systems Project Enables efficient and safe incorporation of renewable energy in the U.S. energy system; shown here is the...

283

acs_JY_jp-2011-008094 1..7  

NLE Websites -- All DOE Office Websites (Extended Search)

C 2011, 115, 10245-10251 ARTICLE pubs.acs.orgJPCC Fast Proton Hopping Detection in Ice I h by Quasi-Elastic Neutron Scattering Itay Presiado, Jyotsana Lal, Eugene...

284

Frequency  

Science Conference Proceedings (OSTI)

... noise terms are the result of environmental changes affecting ... respond to changes in environment, so this ... is probably of broadest concern, but some ...

2002-11-19T23:59:59.000Z

285

Principal Modes of Atmospheric Variability in Model Atmospheres with and without Anomalous Sea Surface Temperature Forcing in the Tropical Pacific  

Science Conference Proceedings (OSTI)

Principal modes of low-frequency atmospheric variability and the influence of sea surface temperature anomalies on such modes are investigated by examining the output from two general circulation model experiments. In the first experiment (the “...

In-Sik Kang; Ngar-Cheung Lau

1986-11-01T23:59:59.000Z

286

joint Spatiotemporal Modes of Surface Temperature and Sea Level Pressure Variability in the Northern Hemisphere during the Last Century  

Science Conference Proceedings (OSTI)

Coherent spatiotemporal modes of climatic variability are isolated based on a multivariate frequency domain singular value decomposition (SVD) of nearly a century of monthly Northern Hemisphere sea level pressure (SLP) and surface temperature ...

Michael E. Mann; Jeffrey Park

1996-09-01T23:59:59.000Z

287

On Sub-ENSO Variability  

Science Conference Proceedings (OSTI)

Multichannel singular spectrum analysis (MSSA) of surface zonal wind, sea surface temperature (SST), 20° isotherm depth, and surface zonal current observations (between 1990 and 2004) identifies three coupled ocean–atmosphere modes of variability ...

Noel S. Keenlyside; Mojib Latif; Anke Dürkop

2007-07-01T23:59:59.000Z

288

Development of an AC Module System: Final Technical Report  

DOE Green Energy (OSTI)

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.

Suparna Kadam; Miles Russell

2012-06-15T23:59:59.000Z

289

Time-frequency analysis and Harmonic Gaussian Functions  

E-Print Network (OSTI)

A method for time-frequency analysis is given. The approach utilizes properties of Gaussian distribution, properties of Hermite polynomials and Fourier analysis. We begin by the definitions of a set of functions called harmonic Gaussian functions. Then these functions are used to define a set of transformations,noted T_n, which associate to a function {\\psi},of the time variable t, a set of functions {\\Psi}_n which depend on time, frequency and frequency (or time) standard deviation. Some properties of the transformations T_n and the functions {\\Psi}_n are given. It is proved in particular that the square of the modulus of each function {\\Psi}_n can be interpreted as a representation of the energy distribution of the signal, represented by the function {\\psi}, in the time-frequency plane for a given value of the frequency (or time) standard deviation. It is also shown that the function {\\psi}, can be recovered from the functions{\\Psi}_n.

Tokiniaina Ranaivoson; Raoelina Andriambololona; Rakotoson Hanitriarivo

2013-03-08T23:59:59.000Z

290

Avoiding low frequency noise in packaged HVAC equipment  

Science Conference Proceedings (OSTI)

The purpose of this article is to help those involved in the design and commissioning of packaged HVAC systems to understand the root causes of low frequency noise problems and how to avoid many of them at the design stage. In the 1980's, two things happened to dramatically change the types of noise problems encountered in typical new construction. The first was the introduction of new energy regulations that favored variable air volume (VAV) distribution systems over constant volume air distribution systems. A by-product of VAV design is that mid- and high frequency sound pressure levels produced by current air terminal devices and diffusers in many applications are significantly lower than in the past. The second factor was a trend away from the use of built-up central station fan equipment in favor of packaged, floor-by-floor air handlers or rooftop units. As a result, today's HVAC system noise problems are not confined to just the roar and hiss of the past, but now include intense low frequency rumble and time modulation. Indeed, most current noise problems in modern buildings occur in the frequency range well below 250 Hz. A large fraction of these are a result of the dominant sound pressure levels in the 12 to 40 Hz region. These factors, combined with a substantial increase in the level of low frequency sound from the rest of the system, can produce a non-neutral, time modulated, rumbly sounding background noise that many people find objectionable.

Ebbing, C.E. (Carrier Corp., Syracuse, NY (United States). Commercial Unitary Division); Blazier, W.E.Jr. (Warren Blazier Associates, San Francisco, CA (United States))

1993-06-01T23:59:59.000Z

291

Power and Energy Measurements Low Frequency  

Science Conference Proceedings (OSTI)

... Power and Energy Measurements, Low-Frequency. Rate our Services. ... Power and Energy Measurements, Low-Frequency (56200C-56202C). ...

2013-06-24T23:59:59.000Z

292

Diagnostics of the Fermilab Tevatron using an AC dipole  

Science Conference Proceedings (OSTI)

The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for the Tevatron, a fast-oscillating (f {approx} 20 kHz) dipole magnet which can be adiabatically turned on and off to establish sustained coherent oscillations of the beam particles without affecting the transverse emittance. By utilizing an existing magnet and a higher power audio amplifier, the cost of the Tevatron AC dipole system became relatively inexpensive. We discuss corrections which must be applied to the driven oscillation measurements to obtain the proper interpretation of beam optical parameters from AC dipole studies. After successful operations of the Tevatron AC dipole system, AC dipole systems, similar to that in the Tevatron, will be build for the CERN LHC. We present several measurements of linear optical parameters (beta function and phase advance) for the Tevatron, as well as studies of non-linear perturbations from sextupole and octupole elements.

Miyamoto, Ryoichi; /Texas U.

2008-08-01T23:59:59.000Z

293

Orbit compensation for the time-varying elliptically polarized wiggler with switching frequency at 100 hz  

SciTech Connect

In October 1996, the elliptically polarized wiggler, installed in the X13 straight section of the NSLS X-ray ring, was commissioned at an operating frequency of 100 hz. This wiggler generates circularly polarized photons in the energy range of 0.1 to 10 keV with AC modulation of polarization helicity. The vertical magnetic field is produced by a hybrid permanent magnet structure, and the horizontal magnetic field is generated by an electromagnet capable of switching at frequencies up to 100 hz. Here, the authors discuss the compensation of the residual vertical and horizontal orbit motion utilizing a time-domain algorithm employing a function generator to drive trim coils at the wiggler ends, and the wideband high precision orbit measurement system of the X-ray ring. The residual orbit motion has been reduced to a level below 1 micron, and the device has been run in regular operations with no negative effect on other users.

Singh, O.; Krinsky, S.

1997-07-01T23:59:59.000Z

294

High frequency transformerless electronics ballast using double inductor-capacitor resonant power conversion for gas discharge lamps  

SciTech Connect

A novel high frequency LCLC double resonant electronic ballast has been developed for gas discharge lamp applications. The ballast consists of a half-bridge inverter which switches at zero voltage crossing and an LCLC resonant circuit which converts a low ac voltage to a high ac voltage. The LCLC resonant circuit has two LC stages. The first LC stage produces a high voltage before the lamp is ignited. The second LC stage limits lamp current with the circuit inductance after the lamp is ignited. In another embodiment a filament power supply is provided for soft start up and for dimming the lamp. The filament power supply is a secondary of the second resonant inductor. 27 figs.

Lai, J.S.

1995-06-20T23:59:59.000Z

295

Frequency Dependence in Forecast Skill  

Science Conference Proceedings (OSTI)

A method is proposed to calculate measures of forecast skill for high, medium and low temporal frequency variations in the atmosphere. This method is applied to a series of 128 consecutive 1 to 10-day forecasts produced at NMC with their ...

H. M. van Den Dool; Suranjana Saha

1990-01-01T23:59:59.000Z

296

Frequency agile optical parametric oscillator  

DOE Patents (OSTI)

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.

Velsko, Stephan P. (Livermore, CA)

1998-01-01T23:59:59.000Z

297

Frequency agile optical parametric oscillator  

DOE Patents (OSTI)

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.

Velsko, S.P.

1998-11-24T23:59:59.000Z

298

Relationships between Low-Frequency Variability in the Southern Hemisphere and Sea Surface Temperature Anomalies  

Science Conference Proceedings (OSTI)

Long-term trends and interannual variations of circulation anomalies in the Southern Hemisphere are examined using the National Centers for Environmental Prediction–National Center for Atmospheric Research reanalysis from 1949 to 1998. The ...

Kingtse C. Mo

2000-10-01T23:59:59.000Z

299

The temperature-jump problem for a variable collision frequency model L. B. Barichello  

E-Print Network (OSTI)

-900 Porto Alegre, RS, Brazil M. Camargoa) Programa de Po´s-Graduac¸a~o em Engenharia Meca^nica, Universidade

Siewert, Charles E.

300

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

Science Conference Proceedings (OSTI)

This study examines the flow induced by an east–west-oriented oceanic thermal front in a highly idealized baroclinic model. Previous work showed that thermal fronts could produce energetic midlatitude jets in an equivalent-barotropic atmosphere ...

Yizhak Feliks; Michael Ghil; Eric Simonnet

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Nonlinear Resonance and Instability of Planetary Waves and Low-Frequency Variability in the Atmosphere  

Science Conference Proceedings (OSTI)

It is demonstrated in this work that linearly unstable planetary waves can be resonantly excited to finite amplitude in a nonlinear barotropic atmosphere with vorticity forcing and dissipation. In a weakly forced/dissipated atmosphere, it is ...

Peili Wu

1993-11-01T23:59:59.000Z

302

Low-Frequency Variability and Wavenumber Selection in Models with Zonally symmetric Forcing  

Science Conference Proceedings (OSTI)

The authors consider a two-layer quasigeostrophic model with linear surface drag and forcing that relaxes to a zonal baroclinically unstable equilibrium state consisting of a meridionally confined temperature gradient. It is observed that the ...

Jeffrey S. Whitaker; Albert Barcilon

1995-02-01T23:59:59.000Z

303

On the Source of Midlatitude Low-Frequency Variability. Part II: Nonlinear Equilibration of Weather Regimes  

Science Conference Proceedings (OSTI)

We present a new statistical-dynamical approach to the concept of weather regimes, including the effect of tralisients, without any assumption other than scale separation. The method is applied to a quasi-geostrophic channel model without ...

Robert Vautard; Bernard Legras

1988-10-01T23:59:59.000Z

304

Southeast Pacific Stratocumulus: High-Frequency Variability and Mesoscale Structures over San Félix Island  

Science Conference Proceedings (OSTI)

Stratocumulus cloud cover patterns and their relationship to drizzle were characterized at San Felix Island (SFI; 26.5°S, 80°W) in the southeast Pacific Ocean. Small closed, large closed, and open cells were identified in about 65% of the ...

David Painemal; René Garreaud; José Rutllant; Paquita Zuidema

2010-03-01T23:59:59.000Z

305

Low-Frequency Sea Level Variability and the Inverted Barometer Effect  

Science Conference Proceedings (OSTI)

For a dynamical interpretation of sea level records, estimates are needed of the isostatic, or so-called inverted barometer, signals (?ib) associated with the ocean response to atmospheric loading. Seasonal and longer-period ?ib signals are ...

Rui M. Ponte

2006-04-01T23:59:59.000Z

306

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

Science Conference Proceedings (OSTI)

This study examines the flow induced in a highly idealized atmospheric model by an east–west-oriented oceanic thermal front. The model has a linear marine boundary layer coupled to a quasigeostrophic, equivalent- barotropic free atmosphere. The ...

Yizhak Feliks; Michael Ghil; Eric Simonnet

2004-05-01T23:59:59.000Z

307

Frequency Response Adequacy and Assessment: Global Industry Practices and Potential Impact of Changing Generation Mix  

Science Conference Proceedings (OSTI)

The electric power industry, the North American Reliability Corporation (NERC), and the US Federal Energy Regulatory Commission (FERC) have expressed concerns about frequency response of the North American power system, which has supposedly declined over the past few decades. In light of the changing generation mix due to increasing penetration of variable generation and planned retirement of fossil-fired generation, the industry is concerned about having adequate primary frequency control ...

2013-12-04T23:59:59.000Z

308

Radio Frequency Identification Tags - Active Tags ...  

Selectable, license free, RF frequency bands; Ultra low power sleep mode; Miniaturized, encapsulated bendable packaging;

309

Data:Ed495bde-91e5-416f-b491-ea26ac6bc0ad | Open Energy Information  

Open Energy Info (EERE)

Ed495bde-91e5-416f-b491-ea26ac6bc0ad Ed495bde-91e5-416f-b491-ea26ac6bc0ad No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2. Demand 3. Energy << Previous 1 2 3 Next >> Basic Information Utility name: Western Area Power Administration (Arizona) Effective date: 2011/10/01 End date if known: Rate name: Regulation and Frequency Response Sector: Industrial Description: Source or reference: www.wapa.gov/dsw/pwrmkt/CRS/Current/Fy2012/RateSched.doc Source Parent: Comments Applicability Demand (kW) Minimum (kW): Maximum (kW): History (months): Energy (kWh) Minimum (kWh): Maximum (kWh): History (months): Service Voltage Minimum (V): Maximum (V): Character of Service Voltage Category: Phase Wiring:

310

Interannual Variability of the Global Radiation Budget  

Science Conference Proceedings (OSTI)

Interannual variability of the global radiation budget, regions that contribute to its variability, and what limits albedo variability are investigated using Clouds and the Earth’s Radiant Energy System (CERES) data taken from March 2000 through ...

Seiji Kato

2009-09-01T23:59:59.000Z

311

Wind Levelized Cost of Energy: A Comparison of Technical and Financing Input Variables  

NLE Websites -- All DOE Office Websites (Extended Search)

1 1 October 2009 Wind Levelized Cost of Energy: A Comparison of Technical and Financing Input Variables Karlynn Cory and Paul Schwabe National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Operated by the Alliance for Sustainable Energy, LLC Contract No. DE-AC36-08-GO28308 Technical Report NREL/TP-6A2-46671 October 2009 Wind Levelized Cost of Energy: A Comparison of Technical and Financing Input Variables Karlynn Cory and Paul Schwabe Prepared under Task No. WER9.3550 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government.

312

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

313

Variable focal length deformable mirror  

DOE Patents (OSTI)

A variable focal length deformable mirror has an inner ring and an outer ring that simply support and push axially on opposite sides of a mirror plate. The resulting variable clamping force deforms the mirror plate to provide a parabolic mirror shape. The rings are parallel planar sections of a single paraboloid and can provide an on-axis focus, if the rings are circular, or an off-axis focus, if the rings are elliptical. The focal length of the deformable mirror can be varied by changing the variable clamping force. The deformable mirror can generally be used in any application requiring the focusing or defocusing of light, including with both coherent and incoherent light sources.

Headley, Daniel (Albuquerque, NM); Ramsey, Marc (Albuquerque, NM); Schwarz, Jens (Albuquerque, NM)

2007-06-12T23:59:59.000Z

314

Comparison of iterative methods for AC analysis in PISCES-IIB  

Science Conference Proceedings (OSTI)

The implementation of an improved small-signal AC simulation capability in the general-purpose device simulator PISCES-IIB is described. The preconditioned generalized conjugate residual (GCR) algorithm has been implemented, which allows AC simulations ...

D. R. Apte; M. E. Law

2006-11-01T23:59:59.000Z

315

DOE 10 CFR Part 431 EERE-2010-BT-TP-0036 RIN 1904-AC-38 Submission...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

0 CFR Part 431 EERE-2010-BT-TP-0036 RIN 1904-AC-38 Submission of Comments by Howe Corporation DOE 10 CFR Part 431 EERE-2010-BT-TP-0036 RIN 1904-AC-38 Submission of Comments by Howe...

316

Docket No. EERE-2011-BT-NOA-0067 and RIN Number 1904-AC52 Ex...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

1-BT-NOA-0067 and RIN Number 1904-AC52 Ex parte Communication Docket No. EERE-2011-BT-NOA-0067 and RIN Number 1904-AC52 Ex parte Communication This memorandum for the record...

317

Prime Contract DE-AC36-99GO10337 Modification M075 SF30 Page...  

NLE Websites -- All DOE Office Websites (Extended Search)

changes to contract DE-AC36-99GO10337: A. Section J, ATTACHMENT 5 "APPLICABLE DIRECTIVES (List B)" of Contract DE-AC36- 99GO10377 is deleted and replaced in its entirety to...

318

tutimura@mist.i.u-tokyo.ac.jp kaneko@ipl.t.u-tokyo.ac.jp  

E-Print Network (OSTI)

://www.misojiro.t.u-tokyo.ac.jp/~tutimura/sem5/ 2004 6 9 ­ p.1/20 · · · · ­ p.2/20 · · · ­ p.3/20 · Java AWT/Swing (Java2D) · Tcl/Tk, Perl Graphics public void paint(Graphics g){ Graphics2D g2 = (Graphics2D)g; .... } ­ p.5/20 Tcl/Tk, Perl/Tk, Ruby/Tk · Tk GUI · Tcl, Perl, Ruby · Tcl/Tk John Ousterhout · Windows, X11, Mac · ­ p.6/20 OpenGL · 3

Murota, Kazuo

319

Radio frequency coaxial feedthrough device  

DOE Patents (OSTI)

A radio frequency coaxial vacuum feedthrough is provided which utilizes a cylindrical ceramic vacuum break formed of an alumina ceramic. The cylinder is coaxially disposed and brazed between tapered coaxial conductors to form a vacuum sealed connection between a pressurized upstream coaxial transmission line and a utilization device located within a vacuum container. The feedthrough provides 50 ohm matched impedance RF feedthrough up to about 500 MHz at power levels in the multimegawatt range.

Owens, Thomas L. (Kingston, TN); Baity, Frederick W. (Oak Ridge, TN); Hoffman, Daniel J. (Oak Ridge, TN); Whealton, John H. (Oak Ridge, TN)

1987-01-01T23:59:59.000Z

320

Power control of a wind farm with active stall wind turbines and AC grid connection  

E-Print Network (OSTI)

turbines with AC connection. The control of other wind farm concepts such as wind farms with DFIG wind

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

The Coordinated Control of a Central Air Conditioning System Based on Variable Chilled Water Temperature and Variable Chilled Water Flow  

E-Print Network (OSTI)

At present, regulation of water flow by means of pump frequency conversion is one of the major methods for power-saving in central air conditioning systems. In this article, optimization regulation for central air conditioning system on the basis of coordinative optimization control for variable chilled water temperature and variable chilled water flow to obtain better power savings is put forward. According to typical meteorological year data, hourly air conditioning load of whole year for every typical room has been calculated with the transmission function method. In order to guarantee each typical room, the highest cooling load rate is used as an input parameter for optimization calculation. Based on the surface cooler check model, the smallest energy consumption of chiller and chiller water pump was taken as the objective function of the optimization model. The performance characteristics of a chiller, water pump, regulation valve and pipeline are taken into account, and the optimization chilled water temperature and chilled water flow were carried out. The case study for a commercial building in Guangzhou showed that the annual power consumption of the chillers and pumps of the air conditioning system is lower by 17% only with employment of variable water flow regulation by pump frequency conversion. In the case of optimization control with coordinative control of variable chilled water temperature and variable chilled water flow, the annual power consumption of the chillers and pumps of the air conditioning system is reduced by 22% in presence of remarkable power saving effects. Increasing the chilled water temperature will reduce the dehumidified capability of the air cooler, and the indoor relative humidity will increase. The simulation showed that the adjustment optimized process meets the comfort of each typical room. The lower the cooling load rate is, the more obvious the effect of power-saving is. The highest power-saving rate appears in December, which is 36.7%. Meanwhile, the least rate appears in July, which is only 14.5%.

Liu, J.; Mai, Y.; Liu, X.

2006-01-01T23:59:59.000Z

322

Operating Reserves and Variable Generation  

DOE Green Energy (OSTI)

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.

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

2011-08-01T23:59:59.000Z

323

H? robust control of DC-AC interfaced microsource in microgrids  

Science Conference Proceedings (OSTI)

This paper focuses on the direct current -- alternating current (DC-AC) interfaced microsource based H ż robust control strategies in microgrids. It presents detail of a DC-AC interfaced microsource model which is connected to the ... Keywords: DC-AC interfaced microsource, H? robust control, Microgrid, f-v droop characteristic, smooth switching

Chun-Xia Dou; Fang Zhao; Xing-Bei Jia; Dong-Le Liu

2013-02-01T23:59:59.000Z

324

VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS  

E-Print Network (OSTI)

VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS by Claudio A. Ca AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS by Claudio A. Ca~nizares A dissertation submitted . . . . . . . . . . . . . 4 1.3.2 AC/DC Transient Energy Functions . . . . . . . . . . . . . . 6 2 System Modelling 8 2

Cañizares, Claudio A.

325

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

SciTech Connect

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.

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

2013-12-01T23:59:59.000Z

326

AC Loss Measurements on a 2G YBCO Coil  

SciTech Connect

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.

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

2011-01-01T23:59:59.000Z

327

Recent developments in thermoacoustically-driven low-frequency projectors  

DOE Green Energy (OSTI)

Thermoacoustic engines are a recent class of devices that can efficiently convert heat to acoustic energy without moving parts or intervening mechanisms. These engines have a natural potential for powering low-frequency sonar projectors with high reliability and efficiencies that cannot be matched by conventional technologies. A recent design study has produced thermoacoustic projector configurations that can execute standard projector performance requirements such as FM sweep and velocity magnitude and phase control in array environments for a wide range of positive and negative radiation resistances. The thermoacoustic driver is a vertically oriented, helium-filled resonator that contains a movable tuning element to vary the resonator frequency. It is coupled to a variable length water column that is tunable by a similar means to adjust the effective source impedance of the device. Modeling results indicate a sweep range of at least an octave for a single device, and maximum overall (heat-to-acoustic) conversion efficiencies of 25% at 50 Hz. Efficiency increases slightly at lower frequencies, and the lowest operational frequency is limited only by the size of the projector. Output power increases linearly with mean pressure, and at depths of 200 m or more, power densities in excess of 500 kW/m{sup 2} are achievable. Control aspects have been investigated, including rapid startup and shutdown that can be performed by manipulating the water tuning column. Future trends and development prospects are discussed. 4 refs.

Ward, W.C.; Merrigan, M.A.

1992-01-01T23:59:59.000Z

328

Recent developments in thermoacoustically-driven low-frequency projectors  

DOE Green Energy (OSTI)

Thermoacoustic engines are a recent class of devices that can efficiently convert heat to acoustic energy without moving parts or intervening mechanisms. These engines have a natural potential for powering low-frequency sonar projectors with high reliability and efficiencies that cannot be matched by conventional technologies. A recent design study has produced thermoacoustic projector configurations that can execute standard projector performance requirements such as FM sweep and velocity magnitude and phase control in array environments for a wide range of positive and negative radiation resistances. The thermoacoustic driver is a vertically oriented, helium-filled resonator that contains a movable tuning element to vary the resonator frequency. It is coupled to a variable length water column that is tunable by a similar means to adjust the effective source impedance of the device. Modeling results indicate a sweep range of at least an octave for a single device, and maximum overall (heat-to-acoustic) conversion efficiencies of 25% at 50 Hz. Efficiency increases slightly at lower frequencies, and the lowest operational frequency is limited only by the size of the projector. Output power increases linearly with mean pressure, and at depths of 200 m or more, power densities in excess of 500 kW/m{sup 2} are achievable. Control aspects have been investigated, including rapid startup and shutdown that can be performed by manipulating the water tuning column. Future trends and development prospects are discussed. 4 refs.

Ward, W.C.; Merrigan, M.A.

1992-05-01T23:59:59.000Z

329

Rapid Variability: What do we learn from correlated mm-/gamma-ray variability in jets ?  

E-Print Network (OSTI)

Densely time sampled multi-frequency flux measurements of the extreme BL Lac object S5 0716+714 over the past three years allow us to study its broad-band variability, and the detailed underlying physics, with emphasis on the location and size of the emitting regions and the evolution with time. We study the characteristics of some prominent mm-/gamma-ray flares in the context of the shock-in-jet model and investigate the location of the high energy emission region. The rapid rise and decay of the radio flares is in agreement with the formation of a shock and its evolution, if a geometrical variation is included in addition to intrinsic variations of the source. We find evidence for a correlation between flux variations at gamma-ray and radio frequencies. A two month time-delay between gamma-ray and radio flares indicates a non-cospatial origin of gamma-rays and radio flux variations in S5 0716+714.

Rani, B; Fuhrmann, L; Lott, B; Boettcher, M; Zensus, J A

2013-01-01T23:59:59.000Z

330

Model-oriented ocean tomography using higher frequency, bottom-mounted hydrophones  

Science Conference Proceedings (OSTI)

A tomographic scheme is presented that ingests ocean acoustic measurements into an ocean model using data from bottom-mounted hydrophones. The short distances between source-receiver pairs (1–10 km) means arrival times at frequencies of 8–11 kHz are readily detectable and often distinguishable. The influence of ocean surface motion causes considerable variability in acoustic travel times. Techniques are presented for measuring travel times and removing the variability due to surface waves. An assimilation technique is investigated that uses differences in measured and modeled acoustic travel times to impose corrections on the oceanographic model. Equations relating travel time differences to oceanographic variables are derived

James K. Lewis; Jason Rudzinsky; Subramaniam Rajan; Peter J. Stein; Amy Vandiver; The KauaiEx Group

2005-01-01T23:59:59.000Z

331

The Incorporation of Atmospheric Variability into DIRSIG  

E-Print Network (OSTI)

of Energy under Contract No. DE-AC02-98CH10886. BNL-63555 CLOSURE EXPERIMENT ­ MODTRAN-3 PREDICTION than calibration uncertainty may be important. The radiative transfer model MODTRAN-3 is used the MODTRAN-3 predicted value with the direct-normal short-wave irradiance measured by a calibrated

Salvaggio, Carl

332

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

SciTech Connect

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.

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

1986-10-01T23:59:59.000Z

333

Breathing HRV by the Concept of AC Ventilation  

NLE Websites -- All DOE Office Websites (Extended Search)

Breathing HRV by the Concept of AC Ventilation Breathing HRV by the Concept of AC Ventilation Speaker(s): Hwataik Han Date: July 10, 2007 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Thomas McKone Heat recovery ventilators are frequently used to save heating/cooling loads of buildings for ventilation. There are several types of HRV's, including a parallel plate type, a rotary type, a capillary type, and a heat pipe type. The breathing HRV is a heat recovery ventilator of a new kind using the concept of alternating-current ventilation. The AC ventilation is the ventilation with the airflow directions reversed periodically. It has an advantage of using a single duct system, for both supply and exhaust purposes. In order to develop a breathing HRV system, the thermal recovery performance should be investigated depending on many parameters, such as

334

Line search methods with variable sample size for unconstrained ...  

E-Print Network (OSTI)

Jun 27, 2011 ... natasa.krklec@dmi.uns.ac.rs. Research supported by ...... That data represent real world problems that come from the discrete choice theory.

335

Simplified wind turbine model for the simulation of frequency support mode of operation  

Science Conference Proceedings (OSTI)

Nowadays, technology evolution and deregulation of the electric utility industry enable Distributed Generation (DG) to play an increasing role in satisfying locally the expanding power demand and generally provide ancillary services to the system. In ... Keywords: control, frequency support, modeling, variable speed wind turbines (VSWT)

F. D. Kanellos; G. J. Tsekouras; C. D. Tsirekis

2011-07-01T23:59:59.000Z

336

Massive Variability Surveys from Venezuela  

E-Print Network (OSTI)

At the Venezuela National Astronomical Observatory we are carrying out variability surveys spanning many hundreds of square degrees near the celestial equator, using an 8k x 8k CCD Mosaic Camera optimized for drift-scanning on a 1m Schmidt telescope. Among the initial efforts was a project to obtain the first moderately deep, homogeneous sample of young stars over an area of ? 180sqr.deg. encompassing the entire Orion OB1 association, one of the nearest and most active regions of star formation. The results show that variability is a powerful technique to identify pre-main sequence populations, specially in sparse areas devoid of gas and dust. We are currently developing a massive database, equipped with web-based data mining tools, that will make our data and results available to the astronomical community. 1.

C. D. Impey; C. E. Petry; César Briceńo

2003-01-01T23:59:59.000Z

337

Massive Variability Surveys from Venezuela  

E-Print Network (OSTI)

At the Venezuela National Astronomical Observatory we are carrying out variability surveys spanning many hundreds of square degrees near the celestial equator, using an 8k x 8k CCD Mosaic Camera optimized for drift-scanning on a 1m Schmidt telescope. Among the initial efforts was a project to obtain the first moderately deep, homogeneous sample of young stars over an area of ~180sqr.deg. encompassing the entire Orion OB1 association, one of the nearest and most active regions of star formation. The results show that variability is a powerful technique to identify pre-main sequence populations, specially in sparse areas devoid of gas and dust. We are currently developing a massive database, equipped with web-based data mining tools, that will make our data and results available to the astronomical community.

Briceńo, C

2003-01-01T23:59:59.000Z

338

Massive Variability Surveys from Venezuela  

E-Print Network (OSTI)

At the Venezuela National Astronomical Observatory we are carrying out variability surveys spanning many hundreds of square degrees near the celestial equator, using an 8k x 8k CCD Mosaic Camera optimized for drift-scanning on a 1m Schmidt telescope. Among the initial efforts was a project to obtain the first moderately deep, homogeneous sample of young stars over an area of ~180sqr.deg. encompassing the entire Orion OB1 association, one of the nearest and most active regions of star formation. The results show that variability is a powerful technique to identify pre-main sequence populations, specially in sparse areas devoid of gas and dust. We are currently developing a massive database, equipped with web-based data mining tools, that will make our data and results available to the astronomical community.

Cesar Briceno

2003-04-03T23:59:59.000Z

339

Radio frequency sustained ion energy  

SciTech Connect

Electromagnetic (E.M.) energy injection method and apparatus for producing and sustaining suprathermal ordered ions in a neutral, two-ion-species, toroidal, bulk equilibrium plasma. More particularly, the ions are produced and sustained in an ordered suprathermal state of existence above the average energy and velocity of the bulk equilibrium plasma by resonant rf energy injection in resonance with the natural frequency of one of the ion species. In one embodiment, the electromagnetic energy is injected to clamp the energy and velocity of one of the ion species so that the ion energy is increased, sustained, prolonged and continued in a suprathermal ordered state of existence containing appreciable stored energy that counteracts the slowing down effects of the bulk equilibrium plasma drag. Thus, selective deuteron absorption may be used for ion-tail creation by radio-frequency excitation alone. Also, the rf can be used to increase the fusion output of a two-component neutral injected plasma by selective heating of the injected deuterons.

Jassby, Daniel L. (Princeton, NJ); Hooke, William M. (Princeton, NJ)

1977-01-01T23:59:59.000Z

340

DE-AC05-06OR23100 Section H  

NLE Websites -- All DOE Office Websites (Extended Search)

DE-AC05-06OR23100 DE-AC05-06OR23100 Section H - Page 1 of 29 PART I - SCHEDULE SECTION H SPECIAL CONTRACT REQUIREMENTS H.1 CONSECUTIVE NUMBERING (MAY 1997)......................................................................... 4 H.2 MODIFICATION AUTHORITY (MAY 1997) ....................................................................... 4 H.3 OVERSIGHT OF CONTRACTOR (OCT 2004)..................................................................... 4 H.4 SMALL BUSINESS SUBCONTRACTING PLAN (SEPT 1999)............................................ 5 H.5 SAFEGUARDS AND SECURITY AWARENESS PROGRAM (MAY 1997)........................ 5 H.6 QUALITY ASSURANCE SYSTEM ALTERNATE I (JUL 2004).......................................... 5 H.7 CONFIDENTIALITY OF INFORMATION (MAY 1997)...................................................... 6 H.8 INDIRECT

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Lecture 2227 Continuous Random Variables  

E-Print Network (OSTI)

-x/100 dx = -e-x/100 100 0 = 1 - e-1 = .632 text typo Example 3 (Light Bulb): The lifetime X, in hours, of a certain kind of light bulb is a continuous random variable with density f(x) = 1500 x2 I(1500,) Check = 1 4 = p Let B denote the number of failures before 2000 hours among 5 light bulbs. Then P(B 1) = P

Scholz, Fritz

342

Lecture 2227 Continuous Random Variables  

E-Print Network (OSTI)

) = 100 0 1 100 e-x/100 dx = -e-x/100 100 0 = 1 - e-1 = .632 text typo Example 3 (Light Bulb): The lifetime X, in hours, of a certain kind of light bulb is a continuous random variable with density f 2000 1500 = 1 - 3 4 = 1 4 = p Let B denote the number of failures before 2000 hours among 5 light bulbs

Scholz, Fritz

343

Frequency synthesis using MEMS piezoelectric resonators  

E-Print Network (OSTI)

(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 ...

Calhoun, Paul Jacob, 1979-

2004-01-01T23:59:59.000Z

344

Definition: Frequency Bias Setting | Open Energy Information  

Open Energy Info (EERE)

Frequency Bias, Balancing Authority, frequency response, smart grid References Glossary of Terms Used in Reliability Standards An inl LikeLike UnlikeLike You like this.Sign...

345

Universal Frequency Spectra of Surface Meteorological Fluctuations  

Science Conference Proceedings (OSTI)

Statistical characteristics of surface meteorology are examined in terms of frequency spectra. According to a recent work using hourly data over 50 yr in the Antarctic, the frequency spectra have a characteristic shape proportional to two ...

Chikara Tsuchiya; Kaoru Sato; Tomoe Nasuno; Akira T. Noda; Masaki Satoh

2011-09-01T23:59:59.000Z

346

A Study of Target Frequency Bond for Frequency Control Performance Score Calculations in an Isolated System.  

E-Print Network (OSTI)

??Power system frequency is one of the key performance indices of system operation. Abnormal frequency deviations would incur negative impacts to power equipments and service… (more)

Lee, Hung-hsi

2010-01-01T23:59:59.000Z

347

Heterodyne laser instantaneous frequency measurement system  

DOE Patents (OSTI)

A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of the frequency during the pulse.

Wyeth, Richard W. (Livermore, CA); Johnson, Michael A. (Pleasanton, CA); Globig, Michael A. (Livermore, CA)

1990-01-01T23:59:59.000Z

348

Heterodyne laser instantaneous frequency measurement system  

DOE Patents (OSTI)

A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of th frequency during the pulse.

Wyeth, Richard W. (Livermore, CA); Johnson, Michael A. (Pleasanton, CA); Globig, Michael A. (Livermore, CA)

1989-01-01T23:59:59.000Z

349

Frequency Control Performance Measurement and Requirements  

E-Print Network (OSTI)

Variable Renewable Energy Resources into the Smart Grid,”Smart Grids, Carnegie Mellon Conference on the Electricity

Illian, Howard F.

2011-01-01T23:59:59.000Z

350

A radio frequency coaxial feedthrough  

DOE Patents (OSTI)

An improved radio frequency coaxial transmission line vacuum feedthrough is provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflection from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits the voltage and power handling capabilities of a feedthrough.

Owens, T.L.

1987-12-07T23:59:59.000Z

351

A Numerical Investigation of the Annual Variability in the Gulf of California  

Science Conference Proceedings (OSTI)

The observations of sea level at the annual frequency in the Gulf of California are reproduced both in amplitude and phase with a horizontal two-dimensional linear two-layer model. The main forcing agents through which variability is explained ...

E. Beier

1997-05-01T23:59:59.000Z

352

Mesoscale Variability Transition from the Western to the Eastern Atlantic along 48°N  

Science Conference Proceedings (OSTI)

The North Atlantic low frequency variability along 48°N is described from 76 year-long velocity-temperature records obtained as part of the Topogulf project whose main objective was to document the effects of the Mid-Atlantic Ridge upon the ...

A. Colin De Verdičre; H. Merchier; M. Arhan

1989-08-01T23:59:59.000Z

353

Decadal Variability of the Kuroshio Extension: Observations and an Eddy-Resolving Model Hindcast  

Science Conference Proceedings (OSTI)

Low-frequency variability of the Kuroshio Extension (KE) is studied using observations and a multidecadal (1950–2003) hindcast by a high-resolution (0.1°), eddy-resolving, global ocean general circulation model for the Earth Simulator (OFES). In ...

Bunmei Taguchi; Shang-Ping Xie; Niklas Schneider; Masami Nonaka; Hideharu Sasaki; Yoshikazu Sasai

2007-06-01T23:59:59.000Z

354

WIDE BAND REGENERATIVE FREQUENCY DIVIDER AND MULTIPLIER  

DOE Patents (OSTI)

A regenerative frequency divider and multiplier having wide band input characteristics is presented. The circuit produces output oscillations having frequencies related by a fixed ratio to input oscillations over a wide band of frequencies. In accomplishing this end, the divider-multiplier includes a wide band input circuit coupled by mixer means to a wide band output circuit having a pass band related by a fixed ratio to that of the input circuit. A regenerative feedback circuit derives a fixed frequency ratio feedback signal from the output circuit and applies same to the mixer means in proper phase relation to sustain fixed frequency ratio oscillations in the output circuit.

Laine, E.F.

1959-11-17T23:59:59.000Z

355

Quantum computation and hidden variables  

E-Print Network (OSTI)

Many physicists limit oneself to an instrumentalist description of quantum phenomena and ignore the problems of foundation and interpretation of quantum mechanics. This instrumentalist approach results to "specialization barbarism" and mass delusion concerning the problem, how a quantum computer can be made. The idea of quantum computation can be described within the limits of quantum formalism. But in order to understand how this idea can be put into practice one should realize the question: "What could the quantum formalism describe?", in spite of the absence of an universally recognized answer. Only a realization of this question and the undecided problem of quantum foundations allows to see in which quantum systems the superposition and EPR correlation could be expected. Because of the "specialization barbarism" many authors are sure that Bell proved full impossibility of any hidden-variables interpretation. Therefore it is important to emphasize that in reality Bell has restricted to validity limits of the no- hidden-variables proof and has shown that two-state quantum system can be described by hidden variables. The later means that no experimental result obtained on two-state quantum system can prove the existence of superposition and violation of the realism. One should not assume before unambiguous experimental evidence that any two-state quantum system is quantum bit. No experimental evidence of superposition of macroscopically distinct quantum states and of a quantum bit on base of superconductor structure was obtained for the present. Moreover same experimental results can not be described in the limits of the quantum formalism.

V. V. Aristov; A. V. Nikulov

2010-07-12T23:59:59.000Z

356

Allianz Climate Solutions ACS GmbH | Open Energy Information  

Open Energy Info (EERE)

Allianz Climate Solutions ACS GmbH Allianz Climate Solutions ACS GmbH Jump to: navigation, search Name Allianz Climate Solutions (ACS) GmbH Place Munich, Germany Zip 80802 Product Munich-based subsidiary of insurance and asset management provider Allianz SE. ACS acts as investment manager, service provider and advisor of climate solutions for Allianz Group and external customers. Coordinates 48.136415°, 11.577531° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":48.136415,"lon":11.577531,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

357

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

E-Print Network (OSTI)

www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY Nuclear Energy in the Enlarged Russia and Ukraine. Interrrupted heating in European cities on cold winter nights adds a new dimension in central and eastern Europe for nuclear power. This working paper notes that with the addition of 12 new

Aickelin, Uwe

358

Carbon Management Plan www.nottingham.ac.uk/sustainability  

E-Print Network (OSTI)

Carbon Management Plan 2010-2020 www.nottingham.ac.uk/sustainability #12;1 Carbon Management Plan 2010-2020 Contents Introduction 2 UK Carbon Policy 3 University Carbon Baselines 4 Recent Performance Trends and KPIs 5 University Targets 8 Strategic Themes 9 Carbon Saving Projects 12 2010-2012 Projects 13

Li, Jingpeng

359

$a-c$ test of holography vs quantum renormalization group  

E-Print Network (OSTI)

We show that a "constructive derivation" of the AdS/CFT correspondence based on the quantum local renormalization group in large N quantum field theories consistently provides the a-c holographic Weyl anomaly in d=4 at the curvature squared order in the bulk action. The consistency of the construction further predicts the form of the metric beta function.

Yu Nakayama

2014-01-21T23:59:59.000Z

360

Ac loss calorimeter for three-phase cable  

SciTech Connect

A calorimeter for measuring ac losses in meter-long lengths of HTS superconducting power transmission line cables is described. The calorimeter, which is based on a temperature difference technique, has a precision of 1 mW and measures single, two-phase (coupling), and three-phase losses. The measurements show significant coupling losses between phases.

Daney, D.E.; Boenig, H.J.; Maley, M.P.; McMurry, D.E.; DeBlanc, B.G. [Los Alamos National Lab., NM (United States). Superconductivity Technology Center

1996-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

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

E-Print Network (OSTI)

quarter of the EU's natural gas consumption, or 6.5% of the bloc's primary energy supply (Nol, 2008; Nol supply function has been applied in natural gas market modelling (e.g., Egging and Gabriel (2006), Eggingwww.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Strategic Eurasian Natural Gas Model for Energy

Aickelin, Uwe

362

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

E-Print Network (OSTI)

in forward markets, due to the high associated storage costs of natural gas and hard coal. Furthermore are self-hedged to the extent that power, natural gas and carbon prices naturally co-move. In particular hard coal and natural #12;www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY gas

Kraft, Markus

363

Thermal Unit Commitment Including Optimal AC Power Flow Constraints  

E-Print Network (OSTI)

Thermal Unit Commitment Including Optimal AC Power Flow Constraints Carlos Murillo{Sanchez Robert J algorithm for unit commitment that employs a Lagrange relaxation technique with a new augmentation. This framework allows the possibility of committing units that are required for the VArs that they can produce

364

www.abdn.ac.uk/energy Energy Institute in  

E-Print Network (OSTI)

Student energy Summit As the oil and gas industry gathers in Aberdeen for this year's offshore europe and regulatory frameworks of energy supply. It will also address the political, environmental, socialwww.abdn.ac.uk/energy RED Revolution Energy Institute in the Energy Capital Pioneering

Pym, David J.

365

http://www.kyoto-u.ac.jp/ja 22 22  

E-Print Network (OSTI)

://www.kyoto-u.ac.jp/en Integrated Human Studies Integrated Human Studies Letters Letters Education Educational Sciences Law Economics Economics and Management Science Science Medicine Medical Science (6) Human Health Sciences Pharmaceutical Sciences Pharmaceutical Sciences Pharmacy (6) Engineering Global Engineering, Architecture

Takada, Shoji

366

http://www.soken.ac.jp/ School of Physical Sciences  

E-Print Network (OSTI)

http://www.soken.ac.jp/ 2012 2013 School of Physical Sciences Department of Structural Molecular Science Department of Functional Molecular Science Department of Astronomical Science Department of Fusion Science Department of Space and Astronautical Science School of High Energy Accelerator Science Department

Kinosita Jr., Kazuhiko

367

http://www.kyoto-u.ac.jp/ja 22 22  

E-Print Network (OSTI)

://www.kyoto-u.ac.jp/en Integrated Human Studies Integrated Human Studies Letters Letters Education Educational Sciences Law Economics Economics and Management Science Science Medicine Medical Science (6) Human Health Sciences Pharmaceutical Sciences Sciences for Drug Discovery Pharmacy (6) Engineering Global Engineering, Architecture

Takada, Shoji

368

http://www.soken.ac.jp/ School of Physical Sciences  

E-Print Network (OSTI)

20132013 20142014 & http://www.soken.ac.jp/ School of Physical Sciences Department of Structural Molecular Science Department of Functional Molecular Science Department of Astronomical Science Department of Fusion Science Department of Space and Astronautical Science School of High Energy Accelerator Science

Kinosita Jr., Kazuhiko

369

Alternating two-way AC-tree automata  

Science Conference Proceedings (OSTI)

We explore the notion of alternating two-way tree automata modulo the theory of finitely many associative-commutative (AC) symbols. This was prompted by questions arising in cryptographic protocol verification, in particular in modeling group key agreement ... Keywords: Alternating tree automata, Associative-commutative, Branching vector addition systems with states, Cryptographic protocols, Resolution, Tree automata, Two-way tree automata

Kumar Neeraj Verma; Jean Goubault-Larrecq

2007-06-01T23:59:59.000Z

370

Nonferromagnetic linear variable differential transformer  

DOE Patents (OSTI)

A nonferromagnetic linear variable differential transformer for accurately measuring mechanical displacements in the presence of high magnetic fields is provided. The device utilizes a movable primary coil inside a fixed secondary coil that consists of two series-opposed windings. Operation is such that the secondary output voltage is maintained in phase (depending on polarity) with the primary voltage. The transducer is well-suited to long cable runs and is useful for measuring small displacements in the presence of high or alternating magnetic fields.

Ellis, James F. (Powell, TN); Walstrom, Peter L. (Oak Ridge, TN)

1977-06-14T23:59:59.000Z

371

Variable-delay feedback control of unstable steady states in retarded time-delayed systems  

E-Print Network (OSTI)

We study the stability of unstable steady states in scalar retarded time-delayed systems subjected to a variable-delay feedback control. The important aspect of such a control problem is that time-delayed systems are already infinite-dimensional before the delayed feedback control is turned on. When the frequency of the modulation is large compared to the system's dynamics, the analytic approach consists of relating the stability properties of the resulting variable-delay system with those of an analogous distributed delay system. Otherwise, the stability domains are obtained by a numerical integration of the linearized variable-delay system. The analysis shows that the control domains are significantly larger than those in the usual time-delayed feedback control, and that the complexity of the domain structure depends on the form and the frequency of the delay modulation.

Aleksandar Gjurchinovski; Viktor Urumov

2010-07-06T23:59:59.000Z

372

DETECTING VARIABILITY IN MASSIVE ASTRONOMICAL TIME-SERIES DATA. II. VARIABLE CANDIDATES IN THE NORTHERN SKY VARIABILITY SURVEY  

SciTech Connect

We present variability analysis of data from the Northern Sky Variability Survey (NSVS). Using the clustering method, which defines variable candidates as outliers from large clusters, we cluster 16,189,040 light curves having data points at more than 15 epochs as variable and non-variable candidates in 638 NSVS fields. Variable candidates are selected depending on how strongly they are separated from the largest cluster and how rarely they are grouped together in eight-dimensional space spanned by variability indices. All NSVS light curves are also cross-correlated with IRAS, AKARI, Two Micron All Sky Survey, Sloan Digital Sky Survey (SDSS), and GALEX objects, as well as known objects in the SIMBAD database. The variability analysis and cross-correlation results are provided in a public online database, which can be used to select interesting objects for further investigation. Adopting conservative selection criteria for variable candidates, we find about 1.8 million light curves as possible variable candidates in the NSVS data, corresponding to about 10% of our entire NSVS sample. Multi-wavelength colors help us find specific types of variability among the variable candidates. Moreover, we also use morphological classification from other surveys such as SDSS to suppress spurious cases caused by blending objects or extended sources due to the low angular resolution of the NSVS.

Shin, Min-Su [Department of Astronomy, The University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Yi, Hahn; Kim, Dae-Won; Chang, Seo-Won [Department of Astronomy, Yonsei University, Seoul 120-749 (Korea, Republic of); Byun, Yong-Ik, E-mail: msshin@umich.edu, E-mail: yihahn@galaxy.yonsei.ac.kr, E-mail: dakim@cfa.harvard.edu, E-mail: seowony@galaxy.yonsei.ac.kr, E-mail: ybyun@yonsei.ac.kr [Department of Astronomy and University Observatory, Yonsei University, Seoul 120-749 (Korea, Republic of)

2012-03-15T23:59:59.000Z

373

Modeling the Effect of Land Surface Evaporation Variability on Precipitation Variability. Part I: General Response  

Science Conference Proceedings (OSTI)

This is the first of a two-part article that investigates the impact of land surface evaporation variability on the interannual variability of precipitation and compares it with the impact caused by sea surface temperature variability. Previous ...

Oreste Reale; Paul Dirmeyer

2002-08-01T23:59:59.000Z

374

Variable Average Absolute Percent Differences  

U.S. Energy Information Administration (EIA) Indexed Site

Variable Variable Average Absolute Percent Differences Percent of Projections Over- Estimated Gross Domestic Product Real Gross Domestic Product (Average Cumulative Growth)* (Table 2) 1.0 42.6 Petroleum Imported Refiner Acquisition Cost of Crude Oil (Constant $) (Table 3a) 35.2 18.6 Imported Refiner Acquisition Cost of Crude Oil (Nominal $) (Table 3b) 34.7 19.7 Total Petroleum Consumption (Table 4) 6.2 66.5 Crude Oil Production (Table 5) 6.0 59.6 Petroleum Net Imports (Table 6) 13.3 67.0 Natural Gas Natural Gas Wellhead Prices (Constant $) (Table 7a) 30.7 26.1 Natural Gas Wellhead Prices (Nominal $) (Table 7b) 30.0 27.1 Total Natural Gas Consumption (Table 8) 7.8 70.2 Natural Gas Production (Table 9) 7.1 66.0 Natural Gas Net Imports (Table 10) 29.3 69.7 Coal Coal Prices to Electric Generating Plants (Constant $)** (Table 11a)

375

Frequency Regulation Basics and Trends  

DOE Green Energy (OSTI)

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.

Kirby, BJ

2005-05-06T23:59:59.000Z

376

Variable speed wind turbine generator with zero-sequence filter  

DOE Patents (OSTI)

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.

Muljadi, E.

1998-08-25T23:59:59.000Z

377

Variable Speed Wind Turbine Generator with Zero-sequence Filter  

DOE Patents (OSTI)

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.

Muljadi, Eduard (Golden, CO)

1998-08-25T23:59:59.000Z

378

Variable speed wind turbine generator with zero-sequence filter  

DOE Patents (OSTI)

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.

Muljadi, Eduard (Golden, CO)

1998-01-01T23:59:59.000Z

379

Sources of Variability of Evapotranspiration in California  

Science Conference Proceedings (OSTI)

The variability (1990–2002) of potential evapotranspiration estimates (ETo) and related meteorological variables from a set of stations from the California Irrigation Management System (CIMIS) is studied. Data from the National Climatic Data ...

Hugo G. Hidalgo; Daniel R. Cayan; Michael D. Dettinger

2005-02-01T23:59:59.000Z

380

Incremental Closure of Free Variable Tableaux  

Science Conference Proceedings (OSTI)

This paper presents a technique for automated theorem proving with free variable tableaux that does not require backtracking. Most existing automated proof procedures using free variable tableaux require iterative deepening and backtracking over applied ...

Martin Giese

2001-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Thermocline Variability in Different Dynamic Regions  

Science Conference Proceedings (OSTI)

The response of thermocline circulation to a variable wind forcing is investigated with quasigeostrophic models. The physical mechanism responsible for the different variability features in various dynamic regions has been highlighted. Special ...

Zhengye Liu

1996-08-01T23:59:59.000Z

382

Integrally formed radio frequency quadrupole  

DOE Patents (OSTI)

An improved radio frequency quadrupole (10) is provided having an elongate housing (11) with an elongate central axis (12) and top, bottom and two side walls (13a-d) symmetrically disposed about the axis, and vanes (14a-d) formed integrally with the walls (13a-d), the vanes (14a-d) each having a cross-section at right angles to the central axis (12) which tapers inwardly toward the axis to form electrode tips (15a-d) spaced from each other by predetermined distances. Each of the four walls (13a-d), and the vanes (14a-d) integral therewith, is a separate structural element having a central lengthwise plane (16) passing through the tip of the vane, the walls (13a-d) having flat mounting surfaces (17, 18) at right angles to and parallel to the control plane (16), respectively, which are butted together to position the walls and vane tips relative to each other.

Abbott, Steven R. (Concord, CA)

1989-01-01T23:59:59.000Z

383

Studies on selection of controlled variables  

E-Print Network (OSTI)

Studies on selection of controlled variables by Vidar Alstad A Thesis Submitted for the Degree. Thus, the selection of controlled variables integrates the optimization and the control layer. Selecting the right controlled variables can be of paramount importance. Many chem­ ical processes

Skogestad, Sigurd

384

Studies on selection of controlled variables  

E-Print Network (OSTI)

Studies on selection of controlled variables by Vidar Alstad A Thesis Submitted for the Degree. Thus, the selection of controlled variables integrates the optimization and the control layer. Selecting the right controlled variables can be of paramount importance. Many chem- ical processes

Skogestad, Sigurd

385

Adaptive sampling for Bayesian variable selection  

E-Print Network (OSTI)

Adaptive sampling for Bayesian variable selection DAVID J. NOTT Department of Statistics for variable selection and for dealing with model un- certainty have become increasingly popular in recent consider adaptive Markov chain Monte Carlo schemes for Bayesian variable selection in Gaussian linear

Blennerhassett, Peter

386

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

SciTech Connect

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.

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

1995-10-01T23:59:59.000Z

387

Variable ratio regenerative braking device  

DOE Patents (OSTI)

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.

Hoppie, Lyle O. (Birmingham, MI)

1981-12-15T23:59:59.000Z

388

Variable residence time vortex combustor  

DOE Patents (OSTI)

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.

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

1987-01-01T23:59:59.000Z

389

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

Science Conference Proceedings (OSTI)

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.

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

390

SIM Time and Frequency Working Group  

Science Conference Proceedings (OSTI)

... SIM Time and Frequency Metrology Course at INTI. Buenos Aires, Argentina (February 4th through February 7th, 2008). Schedule in PDF format. ...

391

SIM Time and Frequency Working Group  

Science Conference Proceedings (OSTI)

... file). Schedule and Slides from Time and Frequency Metrology Course in Buenos Aires, Argentina (2/4/08 to 02/07/08). Schedule ...

392

NIST Time and Frequency Division 1994 - Technical ...  

Science Conference Proceedings (OSTI)

... In three dimensions, the zero-point energy (n x =n y =n z = 0 ... During the last year, Richard Fox of the Optical Frequency Measurements Group has ...

393

Mass Market Demand Response and Variable Generation Integration Issues: A Scoping Study  

NLE Websites -- All DOE Office Websites (Extended Search)

63E 63E Mass Market Demand Response and Variable Generation Integration Issues: A Scoping Study Peter Cappers, Andrew Mills, Charles Goldman, Ryan Wiser, Joseph H. Eto Environmental Energy Technologies Division October 2011 The work described in this report was funded by the Permitting, Siting and Analysis Division of the U.S. Department of Energy's Office of Electricity Delivery and Energy Reliability under Lawrence Berkeley National Laboratory Contract No. DE-AC02- 05CH11231. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Disclaimer This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the

394

Non-Federal Participation in AC Intertie Final Environmental Impact Statement Volume2:Appendices  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Non-Federal Participation in AC Intertie Final Non-Federal Participation in AC Intertie Final Environmental Impact Statement Volume2:Appendices Bonneville DOE/eis- 0145 POWER ADMINISTRATION January 1994 Non-Federal Participation in AC Intertie Draft Environmental Impact Statement Table of Contents Appendix A Life-of-Facilities Capacity Ownership Proposal A1 Appendix B Long-Term Intertie Access Policy B1 Appendix C Glossary C1 Appendix D Biological Assessment ad Supporting Materials

395

UNIXUNIXUNIXUNIX((((OpenSSHOpenSSHOpenSSHOpenSSH)))) (gw.ps.nifs.ac.jp) RSA  

E-Print Network (OSTI)

pdf SSH SSH SSH UNIXUNIXUNIXUNIX((((OpenSSHOpenSSHOpenSSHOpenSSH)))) ssh (gw.ps.nifsTerm: New connection TCP/IP gw.ps.nifs.ac.jp %ssh (-i ) (-l ) gw.ps.nifs.ac.jp The authenticity of host 'gw.ps.nifs.ps.nifs.ac.jp,133.75.37.11' (RSA) to the list of known hosts. Enter passphrase for key '/home

Ito, Atsushi

396

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

Science Conference Proceedings (OSTI)

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.

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

1996-11-01T23:59:59.000Z

397

Power upgrading of transmission line by combining AC-DC transmission  

Science Conference Proceedings (OSTI)

Long extra high voltage (EHV) ac lines cannot be loaded to their thermal limits in order to keep sufficient margin against transient instability. With the scheme proposed in this project, it is possible to load these lines very close to their thermal ... Keywords: extra high voltage (EHV)transmission, flexible ac transmission system (FACTS), power system computer-aided design(PSCAD), simultaneous ac-dc power transmission

Jarupula Somlal

2010-07-01T23:59:59.000Z

398

AC to DC Line Conversion: DConvert Program Version 1.0  

Science Conference Proceedings (OSTI)

The past several years have seen renewed interest in the prospect of converting ac lines to dc operation interest spurred both by the ongoing need to make greater use of existing transmission assets and advances in HVDC converter technology. EPRI has sponsored two major studies dealing with the conversion prospect. The first, 8220Tools for Assessing Conversion of AC Power Transmission Lines to DC,(Product ID # 1020651) and the second, 8220Dc Capability of AC Transmission Lines,(Product ID #1013979). Cont...

2010-10-26T23:59:59.000Z

399

Charging and Transport of Aerosols near AC Transmission Lines: A Literature Review  

Science Conference Proceedings (OSTI)

It has been hypothesized that the charging of airborne pollutant particles by alternating current (AC) transmission lines results in enhanced deposition and retention of these particles in the respiratory tract. This report provides an overview of the effect of AC transmission line corona on ion formation and the transfer of charge to aerosols. A literature review identified gaps in the information required to model the charging of aerosols by AC transmission lines and their dispersal downwind, so that e...

2003-12-08T23:59:59.000Z

400

Free vibration analysis of complete paraboloidal shells of revolution with variable thickness and solid paraboloids from a three-dimensional theory  

Science Conference Proceedings (OSTI)

A three-dimensional (3-D) method of analysis is presented for determining the free vibration frequencies and mode shapes of solid paraboloids and complete (that is, without a top opening) paraboloidal shells of revolution with variable wall thickness. ... Keywords: Complete paraboloidal shells, Ritz method, Shells of revolution, Solid paraboloids, Thick shell, Three-dimensional analysis, Variable thickness, Vibration

Jae-Hoon Kang; Arthur W. Leissa

2005-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Climatology and Interannual Variability in the Intensity of Synoptic-Scale Processes in the North Atlantic from the NCEP–NCAR Reanalysis Data  

Science Conference Proceedings (OSTI)

North Atlantic synoptic-scale processes are analyzed by bandpassing 6-hourly NCEP–NCAR reanalysis data (1958–98) for several synoptic ranges corresponding to ultrahigh-frequency variability (0.5–2 days), synoptic-scale variability (2–6 days), ...

Sergey K. Gulev; Thomas Jung; Eberhard Ruprecht

2002-04-01T23:59:59.000Z

402

New codes and standards for utility - interconnection of AC PV modules  

DOE Green Energy (OSTI)

Photovoltaic (PV) modules that provide only ac power give new dimensions to the use of, and utility interface of, PV systems because all of the dc issues are virtually eliminated. These AC PV modules offer the important advantage that customers may now purchase a PV system without hiring a design engineer. A qualified electrician will be able to install a complete PV system that performs as expected and meets local electrical codes. Simple installations of additional AC PV modules will be possible once the proper branch circuit wiring and protection have been installed. Codes and standards are currently being written to address the utility-interconnect issues for AC PV modules and other interactive inverters. An industry-supported Task Group has recently written and submitted proposals for changes to bring Article 690 of the 1999 National Electrical Code{reg_sign} (NEC{reg_sign}) up to the state-of-the-art for PV devices such as AC PV modules. This paper summarizes the proposed code changes and standards related to the evolving AC PV module technology in the United States. Topics such as the need for dedicated branch circuits for AC PV modules in residential applications are discussed and analyzed. Requirements for limiting the number of AC modules on a branch circuit and the listing requirements that make safe installations are discussed. Coordination of all standards activities for AC module installations, the building-integrated perspectives, and utility-interface issues is discussed.

Bower, W.

1997-10-01T23:59:59.000Z

403

Table AC1. Total Households Using Air-Conditioning Equipment, 2005 ...  

U.S. Energy Information Administration (EIA)

Table AC1. Total Households Using Air-Conditioning Equipment, 2005 Million U.S. Households Type of Air-Conditioning Equipment (millions) Central System

404

Table AC6. Average Consumption for Air-Conditioning by Equipment ...  

U.S. Energy Information Administration (EIA)

Central System 5 Table AC6. Average Consumption for Air-Conditioning by Equipment Type, 2005 Million British Thermal Units (Btu) per Household

405

Table AC7. Average Expenditures for Air-Conditioning by Equipment ...  

U.S. Energy Information Administration (EIA)

Central System 5 Table AC7. Average Expenditures for Air-Conditioning by Equipment Type, 2005 Dollars per Household Type of Air-Conditioning Equipment

406

Impact of inverter station on torsional dynamics of parallel HVdc-ac power system  

SciTech Connect

This paper investigates the impact of an inverter station on the torsional dynamics of a turbine-generator set which is located at the rectifier side of a parallel HVdc-ac power system. The studies show that depending on the stiffness of the inverter ac bus and electrical coupling between the inverter and rectifier ac buses, the inverter closed loop control can have noticeable contribution to the instability of torsional dynamics. This adverse torsional impact is observed in the study results even when the inverter ac bus is fairly strong (ESCR larger than 5.0).

Iravani, M.R.; Zhao, Z.; Hamouda, R.M. (Univ. of Toronto, Ontario (Canada). Dept. of Electrical Engineering)

1993-08-01T23:59:59.000Z

407

Non-Federal Participation In Ac Intertie Final Environmental Impact Statement  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Non-Federal Participation In Ac Intertie Non-Federal Participation In Ac Intertie Final Environmental Impact Statement Volume 1: Environmental Analysis Bonneville DOE/eis-0145 POWER ADMINISTRATION January 1994 Non-Federal Participation in AC Intertie Final Environmental Impact Statement (DOE/EIS - 0145) Responsible Agency: U.S. Department of Energy, Bonneville Power Administration (BPA) Title of Proposed Action: Non-Federal Participation in AC Intertie States and Other Areas Involved: Washington, Oregon, Idaho, Montana, California, Nevada, Utah, New Mexico, Arizona, Wyoming, British Columbia Abstract: BPA is considering action in two areas: (1) non-Federal access to

408

DE-AC05-06OR23100  

NLE Websites -- All DOE Office Websites (Extended Search)

Section B - Page 1 of 10 Section B - Page 1 of 10 PART I - THE SCHEDULE SECTION B SUPPLIES OR SERVICES AND PRICES/COSTS B.1 ITEMS BEING ACQUIRED (ALTERNATE I) (OCT 2004) ................................... 3 B.2 ESTIMATED COST, BASE FEE, AND AWARD FEE (NOV 2004) ...................... 3 B.3 OPTION TO EXTEND THE CONTRACT (NOV 2004) .......................................... 6 B.4 OBLIGATION OF FUNDS (CPAF) (NOV 2004) ...................................................... 8 B.5 DETERMINATION OF AWARD FEE EARNED (NOV 2004) .............................. 9 DE-AC05-06OR23100 Section B - Page 2 of 10 Blank Page DE-AC05-06OR23100 Section B - Page 3 of 10 PART I - THE SCHEDULE SECTION B SUPPLIES OR SERVICES AND PRICES/COSTS B.1 ITEMS BEING ACQUIRED (ALTERNATE I) (OCT 2004)

409

SNL software manual for the ACS Data Analytics Project.  

SciTech Connect

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.

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

410

Control of the LHC 400 MHz RF System (ACS)  

E-Print Network (OSTI)

The LHC ACS RF system is composed of 16 superconducting cavities, eight per ring. Each ring has two cryomodules, each containing four cavities. Each cavity is powered by a 300 kW klystron. The klystrons are grouped in fours, the klystrons in each group sharing a common 58 kV power converter and HV equipment bunker. The ACS RF control system is based on modern industrial programmable controllers (PLCs). A new fast interlock and alarm system with inbuilt diagnostics has been developed. Extensive use of the FIPIO Fieldbus drastically decreases the cabling complexity and brings improved signal quality, increased reliability and easier maintenance. Features of the implementation, such as system layout, communication and the high-level software interface are described. Operational facilities such as the automatic switch on procedure are described, as well as the necessary specialist tools and interfaces. A complete RF chain, including high voltage, cryomodule and klystron is presently being assembled in order to ch...

Arnaudon, L; Maesen, P; Prax, M

2004-01-01T23:59:59.000Z

411

On-Chip AC self-test controller  

DOE Patents (OSTI)

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.

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

2009-09-29T23:59:59.000Z

412

AC/AB Stacking Boundaries in Bilayer Graphene  

Science Conference Proceedings (OSTI)

Boundaries, including phase boundaries, grain boundaries, and domain boundaries, are known to have an important influence on material properties. Here, dark-field (DF) transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) imaging are combined to provide a full view of boundaries between AB and AC stacking domains in bilayer graphene across length scales from discrete atoms to the macroscopic continuum. Combining the images with results obtained by density functional theory (DFT) and classical molecular dynamics calculations, we demonstrate that the AB/AC stacking boundaries in bilayer graphene are nanometer-wide strained channels, mostly in the form of ripples, producing smooth low-energy transitions between the two different stackings. Our results provide a new understanding of the novel stacking boundaries in bilayer graphene, which may be applied to other layered two-dimensional materials as well.

Lin, Junhao [ORNL; Fang, Wenjing [Massachusetts Institute of Technology (MIT); Zhou, Wu [ORNL; Lupini, Andrew R [ORNL; Idrobo Tapia, Juan C [ORNL; Kong, Jing [Massachusetts Institute of Technology (MIT); Pennycook, Stephen J [ORNL; Pantelides, Sokrates T [ORNL

2013-01-01T23:59:59.000Z

413

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

DOE Patents (OSTI)

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.

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

1998-01-01T23:59:59.000Z

414

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

DOE Patents (OSTI)

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.

Mikesell, H.E.; Lucy, E.

1998-02-03T23:59:59.000Z

415

Hard X-ray Variability of AGN  

E-Print Network (OSTI)

Aims: Active Galactic Nuclei are known to be variable throughout the electromagnetic spectrum. An energy domain poorly studied in this respect is the hard X-ray range above 20 keV. Methods: The first 9 months of the Swift/BAT all-sky survey are used to study the 14 - 195 keV variability of the 44 brightest AGN. The sources have been selected due to their detection significance of >10 sigma. We tested the variability using a maximum likelihood estimator and by analysing the structure function. Results: Probing different time scales, it appears that the absorbed AGN are more variable than the unabsorbed ones. The same applies for the comparison of Seyfert 2 and Seyfert 1 objects. As expected the blazars show stronger variability. 15% of the non-blazar AGN show variability of >20% compared to the average flux on time scales of 20 days, and 30% show at least 10% flux variation. All the non-blazar AGN which show strong variability are low-luminosity objects with L(14-195 keV) < 1E44 erg/sec. Conclusions: Concerning the variability pattern, there is a tendency of unabsorbed or type 1 galaxies being less variable than the absorbed or type 2 objects at hardest X-rays. A more solid anti-correlation is found between variability and luminosity, which has been previously observed in soft X-rays, in the UV, and in the optical domain.

V. Beckmann; S. D. Barthelmy; T. J. -L. Courvoisier; N. Gehrels; S. Soldi; J. Tueller; G. Wendt

2007-09-14T23:59:59.000Z

416

Performance testing of the AC propulsion ELX electric vehicle  

DOE Green Energy (OSTI)

Performance testing of the AC Propulsion ELX electric vehicle is described. Test data are presented and analyzed. The ELX vehicle is the first of a series of electric vehicles of interest to the California Air Resources Board. The test series is being conducted under a Cooperative Research and Development Agreement (CRADA) between the US Department of energy and the California Air Resources Board. The tests which were conducted showed that the AC Propulsion ELX electric vehicle has exceptional acceleration and range performance. when the vehicle`s battery was fully charged, the vehicle can accelerate from 0 to 96 km/h in about 10 seconds. Energy consumption and range tests using consecutive FUDS and HWFET Driving cycles (the all-electric cycle) indicate that the energy economy of the AC Propulsion ELX electric vehicle with regenerative braking is 97 W{center_dot}h/km, with a range of 153 km (95 miles). Computer simulations performed using the SIMPLEV Program indicate that the vehicle would have a range of 327 km (203 miles) on the all-electric cycle if the lead acid batteries were replaced with NiMH batteries having an energy density of 67 W{center_dot}h/kg. Comparisons of FUDS test data with and without regenerative braking indicated that regenerative braking reduced the energy consumption of the ELX vehicle by approximately 25%.

Kramer, W.E.; MacDowall, R.D.; Burke, A.F.

1994-06-01T23:59:59.000Z

417

Definition: Frequency Response | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Frequency Response Jump to: navigation, search Dictionary.png Frequency Response (Equipment) The ability of a system or elements of the system to react or respond to a change in system frequency. (System) The sum of the change in demand, plus the change in generation, divided by the change in frequency, expressed in megawatts per 0.1 Hertz (MW/0.1 Hz).[1] View on Wikipedia Wikipedia Definition Related Terms system, smart grid References ↑ Glossary of Terms Used in Reliability Standards An i LikeLike UnlikeLike You like this.Sign Up to see what your friends like. nline Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Frequency_Response&oldid=502580"

418

Multi-dimensional ultra-high frequency passive radio frequency identification tag antenna designs  

E-Print Network (OSTI)

In this thesis, we present the design, simulation, and empirical evaluation of two novel multi-dimensional ultra-high frequency (UHF) passive radio frequency identification (RFID) tag antennas, the Albano-Dipole antenna ...

Delichatsios, Stefanie Alkistis

2006-01-01T23:59:59.000Z

419

Definition: Variable Peak Pricing | Open Energy Information  

Open Energy Info (EERE)

Variable Peak Pricing Variable Peak Pricing Jump to: navigation, search Dictionary.png Variable Peak Pricing Variable Peak Pricing (VPP) is a hybrid of time-of-use and real-time pricing where the different periods for pricing are defined in advance (e.g., on-peak=6 hours for summer weekday afternoon; off-peak= all other hours in the summer months), but the price established for the on-peak period varies by utility and market conditions.[1] Related Terms real-time pricing References ↑ https://www.smartgrid.gov/category/technology/variable_peak_pricing [[C LikeLike UnlikeLike You like this.Sign Up to see what your friends like. ategory: Smart Grid Definitionssmart grid,off-peak,on-peak,smart grid, |Template:BASEPAGENAME]]smart grid,off-peak,on-peak,smart grid, Retrieved from "http://en.openei.org/w/index.php?title=Definition:Variable_Peak_Pricing&oldid=50262

420

A Generalized Class of Stationary Frame-Current Controllers for Grid-Connected AC–DC Converters  

E-Print Network (OSTI)

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 ...

Hwang, J. George

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

NERC Presentation: Accommodating High Levels of Variable Generation...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

high levels of variable electricity eneration. Variable resources are types of electric power generation that rely on an uncontrolled, "variable" fuel (e.g. wind, sunlight,...

422

The use of 'race' as a variable in biomedical research  

E-Print Network (OSTI)

a variable in biomedical research but mainly to monitor thea Variable in Biomedical Research A dissertation submittedVariable in Biomedical Research…………. Manifest, Operative and

Efstathiou, Sophia

2009-01-01T23:59:59.000Z

423

Data:360311ac-6ca0-4146-89ac-db323120f125 | Open Energy Information  

Open Energy Info (EERE)

11ac-6ca0-4146-89ac-db323120f125 11ac-6ca0-4146-89ac-db323120f125 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2. Demand 3. Energy << Previous 1 2 3 Next >> Basic Information Utility name: Northern States Power Co - Minnesota Effective date: 2012/05/01 End date if known: Rate name: LIMITED OFF PEAK SERVICE Transmission Transformed (Commercial & Industrial) Sector: Commercial Description: Available to any customers for controlled loads that will be energized only for the time period between 10:00 p.m. to 6:30 a.m. daily. DETERMINATION OF CUSTOMER BILLS Customer bills shall reflect energy charges (if applicable) based on customer's kWh usage, plus a customer charge (if applicable), plus demand charges (if applicable) based on customer's kW billing demand as defined. INTERIM RATE ADJUSTMENT A 4.49% Interim Rate Surcharge will be applied to rate components specified in the "Interim Rate Surcharge Rider." In addition, customer bills under this rate are subject to the following adjustments and/or charges. FUEL CLAUSE Bills are subject to the adjustments provided for in the Fuel Clause Rider. RESOURCE ADJUSTMENT Bills are subject to the adjustments provided for in the Conservation Improvement Program Adjustment Rider, the State Energy Policy Rate Rider, the Renewable Development Fund Rider, the Transmission Cost Recovery Rider, the Renewable Energy Standard Rider and the Mercury Cost Recovery Rider.

424

Monitoring of Photovoltaic Plant Output and Variability  

Science Conference Proceedings (OSTI)

The performance of photovoltaic (PV) systems, including variability characteristics, is of increasing interest to utilities as they integrate more solar energy onto the electric grid. This study is part of a multi-year research series to investigate influencing factors that affect PV plant output, variability, and approaches to system management. It explores PV variability both from a grid perspective and through examination of project design aspects that can affect annual power production. ...

2012-12-12T23:59:59.000Z

425

Envera Variable Compression Ratio Engine  

DOE Green Energy (OSTI)

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

Charles Mendler

2011-03-15T23:59:59.000Z

426

How ready is `capture ready'? May 2008 SCCS for WWF -1(44) -www.geos.ed.ac.uk/sccs Nils.Markusson@ed.ac.uk S.Haszeldine@ed.ac.uk  

E-Print Network (OSTI)

@mines.edu. § Division of Economics, University of Stirling. i.a.lange@stir.ac.uk. ¶ Dyson School of Applied Economics. Such a correlation may be explained in part through engineering aspects of plant operations. For instance, increasing

Haszeldine, Stuart

427

Natural Gas Variability In California: Environmental Impacts...  

NLE Websites -- All DOE Office Websites (Extended Search)

Natural Gas Variability In California: Environmental Impacts And Device Performance, Combustion Modeling of Pollutant Emissions From a Residential Cooking Range Title Natural Gas...

428

NREL: Transmission Grid Integration - Variability of Renewable...  

NLE Websites -- All DOE Office Websites (Extended Search)

as variable generation sources because their electricity production varies based on the availability of wind and sun. However, they are not the only source of variation in a...

429

Variable-Period Undulators for Synchrotron Radiation  

DOE Patents (OSTI)

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.

Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

2005-02-22T23:59:59.000Z

430

THE FERRITE BIASING SYSTEM FOR THE RADIO FREQUENCY CAVITIES OF THE PRINCETON-PENNSYLVANIA 3 Bev PROTON SYNCHROTRON  

SciTech Connect

A description is given of the ferrite biasing system for the four tuned radio frequency cavities of the synchrotron. Each ferrite loaded double cavity has a single turn bias winding which is driven to a peak current of 13,500 amperes by a push-pull transformer arrangement. There is automatic tap changing of the transformer to accommodate the variable impedance load (for power considerations). The programming and frequency response of the system have to be such that each cavity can operate as the reso nant circuit of a self tracking radio frequency amplifier over the frequency range 6.5 to 30 Mc at the 20 cps repetition rate of the synchrotron. Between acceleration cycles it is necessary to program the ferrite to a given magnetic state, near that of maximum radio frequency permeability. (auth)

Rees, G.H.

1962-08-29T23:59:59.000Z

431

Turbine bucket natural frequency tuning rib  

SciTech Connect

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.

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

432

High power radio frequency attenuation device  

DOE Patents (OSTI)

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.

Kerns, Quentin A. (Bloomingdale, IL); Miller, Harold W. (Winfield, IL)

1984-01-01T23:59:59.000Z

433

Design of high performance frequency synthesizers in communication systems  

E-Print Network (OSTI)

Frequency synthesizer is a key building block of fully-integrated wireless communication systems. Design of a frequency synthesizer requires the understanding of not only the circuit-level but also of the transceiver system-level considerations. This dissertation presents a full cycle of the synthesizer design procedure starting from the interpretation of standards to the testing and measurement results. A new methodology of interpreting communication standards into low level circuit specifications is developed to clarify how the requirements are calculated. A detailed procedure to determine important design variables is presented incorporating the fundamental theory and non-ideal effects such as phase noise and reference spurs. The design procedure can be easily adopted for different applications. A BiCMOS frequency synthesizer compliant for both wireless local area network (WLAN) 802.11a and 802.11b standards is presented as a design example. The two standards are carefully studied according to the proposed standard interpretation method. In order to satisfy stringent requirements due to the multi-standard architecture, an improved adaptive dual-loop phase-locked loop (PLL) architecture is proposed. The proposed improvements include a new loop filter topology with an active capacitance multiplier and a tunable dead zone circuit. These improvements are crucial for monolithic integration of the synthesizer with no off-chip components. The proposed architecture extends the operation limit of conventional integerN type synthesizers by providing better reference spur rejection and settling time performance while making it more suitable for monolithic integration. It opens a new possibility of using an integer-N architecture for various other communication standards, while maintaining the benefit of the integer-N architecture; an optimal performance in area and power consumption.

Moon, Sung Tae

2005-05-01T23:59:59.000Z

434

436 IEEE/ASME TRANSACTIONS ON MECHATRONICS, VOL. 9, NO. 2, JUNE 2004 Torque and Velocity Ripple Elimination of AC  

E-Print Network (OSTI)

Elimination of AC Permanent Magnet Motor Control Systems Using the Internal Model Principle Wai-Chuen Gan and velocity ripple elimination in AC permanent magnet (PM) motor control systems. The torque ripples caused-free output response. Index Terms--AC permanent magnet motor, gain scheduled (GS) speed regulators, internal

Qiu, Li

435

Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films and  

E-Print Network (OSTI)

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

Lewis, Robert Michael

436

EQUALITY PLAN Please contact equalopportunities@swansea.ac.uk for alternative formats of this  

E-Print Network (OSTI)

://www.swan.ac.uk/media/EOC%20Annual%20Report%202009- 2010.pdf The University Fee Plan Details of the University Fee Plan 2012-2013 http://www.swan.ac.uk/media/EOC%20Annual%20Report%202010-2011.pdf Other university data University Fee partnership (where appropriate). These groups all report to the University Equal Opportunities Committee (EOC

Martin, Ralph R.

437

A new arrangement of AC/DC converters for high direct-current applications  

Science Conference Proceedings (OSTI)

A novel AC/DC converter designed for high-output direct currents and tight output voltage regulations is introduced. The proposed converter exhibits good efficiency and very low output voltage ripple. In order to verify the performances of the four-stage ... Keywords: AC/DC converter, FFT, electrical distribution systems, high direct-current

Francesco Muzi; Luigi Passacantando

2008-04-01T23:59:59.000Z

438

Improvements in power quality and efficiency with a new AC/DC high current converter  

Science Conference Proceedings (OSTI)

A very flexible AC/DC converter featuring high-output current, reduced voltage ripple and highly adjustable current control is described. The whole system consists of four stages and uses a proper switching technique in conjunction with a feedback control ... Keywords: AC/DC converter, FFT, electrical distribution systems, high direct-current, power quality

Francesco Muzi; Luigi Passacantando

2008-05-01T23:59:59.000Z

439

Constructive and destructive interferences of Stark resonances induced by an ac field in atomic hydrogen  

SciTech Connect

We study theoretically the problem of a hydrogen atom exposed both to a static dc field and to a monochromatic ac field. We show that, in the presence of an ac field, a constructive (or destructive) interference occurs between the excited (Rydberg) Stark resonance states and the hydrogenic ground state. This mechanism is responsible for dramatic enhancement (or suppression) of the corresponding photoionization rates.

Pawlak, Mariusz; Bylicki, Miroslaw; Moiseyev, Nimrod; Sindelka, Milan [Instytut Fizyki, Uniwersytet Mikolaja Kopernika, ul. GrudziaPdzka 5, PL-87-100 Torun (Poland); Schulich Faculty of Chemistry, Department of Physics and Minerva Center of Nonlinear Physics of Complex Systems, Technion-Israel Institute of Technology, Haifa, IL-32000 (Israel)

2010-12-15T23:59:59.000Z

440

Lift-and-project relaxations of AC microgrid distribution system planning  

Science Conference Proceedings (OSTI)

We apply relaxation procedures to polynomial optimization problems that originate in transmission system planning, and obtain new convex formulations for the AC case. The approach is novel because the optimization is efficient but also addresses the ... Keywords: AC power flow, lift-and-project relaxation, linear programming, transmission system planning

Joshua A. Taylor; Franz S. Hover

2011-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Complex-demand knapsack problems and incentives in AC power systems  

Science Conference Proceedings (OSTI)

We consider AC electrical systems where each electrical device has a power demand expressed as a complex number, and there is a limit on the magnitude of total power supply. Motivated by this scenario, we introduce the complex-demand knapsack problem ... Keywords: ac electrical system, approximation algorithm, fptas, incentive compatibility, knapsack problem, smart grid, truthfulness

Lan Yu, Chi-Kin Chau

2013-05-01T23:59:59.000Z

442

Study on the operation of a low-voltage AC microgrid with multiple distributed generations  

Science Conference Proceedings (OSTI)

This paper aims to study the operation of a grid-connected low-voltage AC microgrid with multiple distributed generations (DGs). First of all, a 400 V low-voltage AC microgrid integrated with a 30 kW microturbine generator, a 13 kW photovoltaic generation ... Keywords: distributed generators, distribution systems, microgrids, steady-state analysis, three-phase power flow

Wei-Tzer Huang

2010-12-01T23:59:59.000Z

443

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

E-Print Network (OSTI)

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

Teodorescu, Remus

444

Analysis of core damage frequency: Peach Bottom, Unit 2 internal events appendices  

SciTech Connect

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.

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

445

Grassmann Variables in Jordan Matrix Models  

E-Print Network (OSTI)

Here we demonstrate the emergence of Grassmann variables in matrix models based on the exceptional Jordan algebra. The Grassmann algebras are built naturally using the octonion algebra. We argue the appearance of Grassmann variables solidifies the relationship between supersymmetry and triality.

Michael Rios

2005-03-02T23:59:59.000Z

446

THE MULTI-USE STEINEL VARIABLE TEMPERATURE  

E-Print Network (OSTI)

THE MULTI-USE STEINEL VARIABLE TEMPERATURE ELECTRONICALLY CONTROLLED HEAT GUNTEMPERATURE RANGE 212 COMBUSTIBLE LIQUIDS. DO NOT USE FOR: · Heating gas engines · Heating car batteries · Thawing refrigerator equipment Specifications Temperature Variable from 212° F to 1100° F Watts 1500W Weight 1.5 lbs. Supply

Kleinfeld, David

447

THE MULTI-USE STEINEL VARIABLE TEMPERATURE  

E-Print Network (OSTI)

THE MULTI-USE STEINEL VARIABLE TEMPERATURE ELECTRONICALLY CONTROLLED HEAT GUNTEMPERATURE RANGE 212 COMBUSTIBLE LIQUIDS. DO NOT USE FOR: · Heating gas engines · Heating car batteries · Thawing refrigerator equipment Specifications Temperature Variable from 212" F to 1100° F Watts 1500W Weight 1.5 lbs. Supply

Kleinfeld, David

448

Internal Variability of Indian Ocean SST  

Science Conference Proceedings (OSTI)

A 40-yr integration of an eddy-resolving numerical model of the tropical Indian Ocean is analyzed to quantify the interannual variability that is caused by the internal variability of ocean dynamics. It is found that along the equator in the ...

Markus Jochum; Raghu Murtugudde

2005-09-01T23:59:59.000Z

449

Gradient based variable forgetting factor RLS algorithm  

Science Conference Proceedings (OSTI)

An accurate new variable forgetting factor recursive least-square adaptive algorithm is derived. An improved mean square behaviour analysis is presented, which shows that the theoretical analysis and the simulation results are close to each other. The ... Keywords: RLS algorithm, adaptive filters, variable forgetting factor

C. F. So; S. C. Ng; S. H. Leung

2003-06-01T23:59:59.000Z

450

Variable orifice using an iris shutter  

DOE Patents (OSTI)

A variable orifice forming mechanism utilizing an iris shutter arrangement adapted to control gas flow, conductance in vacuum systems, as a heat shield for furnace windows, as a beam shutter in sputtering operations, and in any other application requiring periodic or continuously-variable control of material, gas, or fluid flow.

Beeman, Raymond (El Cerrito, CA); Brajkovich, Steven J. (Fremont, CA)

1978-01-01T23:59:59.000Z

451

Markedness and frequency: a computational analysis  

Science Conference Proceedings (OSTI)

When the markedness analysis is extended to the lexical and grammatical levels, the question arises whether an analogue of the markedness/frequency correlation, observed in phonology, also exists on these higher linguistic levels. This article presents ...

Henry Ku?era

1982-07-01T23:59:59.000Z

452

Very-High-Frequency Resonant Boost Converters  

E-Print Network (OSTI)

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 ...

Perreault, David J.

453

Radio frequency dc-dc power conversion  

E-Print Network (OSTI)

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 ...

Rivas, Juan, 1976-

2007-01-01T23:59:59.000Z

454

Propagation of Rossby Waves of Nonzero Frequency  

Science Conference Proceedings (OSTI)

The propagation of Rossby waves of positive and negative frequency, corresponding to eastward and westward phase speeds, respectively, is investigated. The techniques used are theoretical analysis, ray tracing, and initial value problems in ...

Gui-Ying Yang; Brian J. Hoskins

1996-08-01T23:59:59.000Z

455

Security approaches for Radio Frequency Identification systems  

E-Print Network (OSTI)

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 ...

Foley, Joseph Timothy, 1976-

2007-01-01T23:59:59.000Z

456

Radio Frequency Identification : regulating information privacy protection  

E-Print Network (OSTI)

As applications of Radio Frequency Identification (RFID) become more profuse, the technology itself is stirring up some controversy. Due to its potential for amassing large amounts of information about both people and ...

Laufer, Deanna (Deanna Raquel)

2007-01-01T23:59:59.000Z

457

Definition: Frequency Bias | Open Energy Information  

Open Energy Info (EERE)

Authority Area, Balancing Authority, frequency error, smart grid References Glossary of Terms Used in Reliability Standards An inl LikeLike UnlikeLike You like this.Sign...

458

Definition: Frequency Error | Open Energy Information  

Open Energy Info (EERE)

difference between the actual and scheduled frequency. (FA - FS)1 References Glossary of Terms Used in Reliability Standards An LikeLike UnlikeLike You like this.Sign Up...

459

Frequency Discrimination of Random?Amplitude Tones  

Science Conference Proceedings (OSTI)

The ability of human observers to discriminate frequencies of tones between 1000 and 15 000 cps was measured in a temporal 2?alternative forced?choice discriminationexperiment. On each trial

G. Bruce Henning

1965-01-01T23:59:59.000Z

460

The Frequency Distribution of Thunderstorm Durations  

Science Conference Proceedings (OSTI)

The frequency distributions of thunderstorm durations were analyzed for 30 years at 36 stations in the United States in order to develop an appropriate summarizing statistic for durations. The incomplete gamma function provides a close fit to the ...

P. J. Robinson; D. R. Easterling

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

On the phenomenological classification of continuum radio spectra variability patterns of Fermi blazars  

E-Print Network (OSTI)

The F-GAMMA program is a coordinated effort to investigate the physics of Active Galactic Nuclei (AGNs) via multi-frequency monitoring of {\\em Fermi} blazars. The current study is concerned with the broad-band radio spectra composed of measurement at ten frequencies between 2.64 and 142 GHz. It is shown that any of the 78 sources studied can be classified in terms of their variability characteristics in merely 5 types of variability. The first four types are dominated by spectral evolution and can be reproduced by a simple two-component system made of the quiescent spectrum of a large scale jet populated with a flaring event evolving according to Marscher & Gear (1985). The last type is characterized by an achromatic change of the broad-band spectrum which must be attributed to a completely different mechanism. Here are presented, the classification, the assumed physical system and the results of simulations that have been conducted.

Angelakis, E; Nestoras, I; Fromm, C M; Schmidt, R; Zensus, J A; Marchili, N; Krichbaum, T P; Perucho-Pla, M; Ungerechts, H; Sievers, A; Riquelme, D

2011-01-01T23:59:59.000Z

462

Bond Graph Modeling Of Variable Structure Systems  

E-Print Network (OSTI)

The problem of describing variable structure models in a compact, object--oriented fashion is revisited and analyzed from the perspective of bond graph modeling. Traditionally, bond graphs have always been used to describe continuous-- time physical processes with a fixed structure. Yet, this paper shall demonstrate that bond graphs are equally suitable to describe variable structure models as fixed structure models. Moreover, a bond graph description of variable structure models can teach us a lot about the essential properties of variable structure models, properties that are not easily visible when other modeling approaches are taken. The paper discusses issues related to causality reassignment and conditional index changes as a consequence of switching in a physical system. Keywords: Bond graphs, variable structure system, computational causality, conditional index change, switching, object--oriented modeling, Dymola. INTRODUCTION When the causality strokes were added to the forme...

François E. Cellier; Martin Otter; Hilding Elmqvist

1995-01-01T23:59:59.000Z

463

Development of Radio Frequency Exposure Standards  

Science Conference Proceedings (OSTI)

While unconfirmed claims of adverse human health effects from electromagnetic radiation date to the 1930s, development of modern safety standards did not begin until the 1952 Hirsch study of eye damage at a microwave power density of 100 mW/cm2. Early work on standards focused on microwave frequencies due to rapid development of radar and microwave communications links. In the years since 1952, radio frequency (RF) exposure standards have kept pace with those technological advancements. While refinements...

2004-11-01T23:59:59.000Z

464

Overview of Personal Radio Frequency Communication Technologies  

Science Conference Proceedings (OSTI)

The growth of wireless electronic communication devices and their applications is creating an increasingly complex radio frequency (RF) environment in the workplace and home. Personal communication applications discussed in this report include cordless telephones, analog cellular telephones, digital cellular telephones, and a dozen more. Depending on the specific wireless device, different frequency ranges, modulation types, multiple access types, and power levels can be encountered. The significant grow...

2008-09-09T23:59:59.000Z

465

Data:304c7bdb-9ac5-4bea-ab51-af99e3f22ac3 | Open Energy Information  

Open Energy Info (EERE)

bdb-9ac5-4bea-ab51-af99e3f22ac3 bdb-9ac5-4bea-ab51-af99e3f22ac3 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2. Demand 3. Energy << Previous 1 2 3 Next >> Basic Information Utility name: Cuming County Public Pwr Dist Effective date: 2011/12/14 End date if known: Rate name: Security Lighting Unmetered Lights 400W MV Sector: Lighting Description: Source or reference: Ilinois State University Rate binder # 10 Source Parent: Comments Applicability Demand (kW) Minimum (kW): Maximum (kW): History (months): Energy (kWh) Minimum (kWh): Maximum (kWh): History (months): Service Voltage Minimum (V): Maximum (V): Character of Service Voltage Category: Phase Wiring: << Previous 1 2 3 Next >>

466

Data:A865370d-061c-4ac0-bad4-a28ee66d26ac | Open Energy Information  

Open Energy Info (EERE)

d-061c-4ac0-bad4-a28ee66d26ac d-061c-4ac0-bad4-a28ee66d26ac No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2. Demand 3. Energy << Previous 1 2 3 Next >> Basic Information Utility name: City of St Marys, Ohio (Utility Company) Effective date: 2001/06/10 End date if known: Rate name: Commercial General Service Distribution Rate 128 Sector: Commercial Description: *This rate schedule is available for lighting and power for those customers establishing a minimum demand of 1,000 KW and who enter into a Service Agreement with the City for the purchase from the City of St. Marys for its electric energy requirements. Character of service:Service will be Three (3) Phase, Alternating Current, 60 Hertz, 12,470 Volts unregulated.

467

Data:537e7901-a057-48d1-ac7a-c08908a00772 | Open Energy Information  

Open Energy Info (EERE)

-a057-48d1-ac7a-c08908a00772 -a057-48d1-ac7a-c08908a00772 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2. Demand 3. Energy << Previous 1 2 3 Next >> Basic Information Utility name: City of Jasper, Indiana (Utility Company) Effective date: 2009/09/01 End date if known: Rate name: Municipal Street Light (400 W Mercury Vapor) Sector: Lighting Description: Applicable only for street, alley and park lighting and traffic signals of the City of Jasper. Source or reference: ISU Documentation Source Parent: Comments Applicability Demand (kW) Minimum (kW): Maximum (kW): History (months): Energy (kWh) Minimum (kWh): Maximum (kWh): History (months): Service Voltage Minimum (V): Maximum (V):

468

Data:1f029483-379f-4568-ac06-8bd5cb1ac7b0 | Open Energy Information  

Open Energy Info (EERE)

3-379f-4568-ac06-8bd5cb1ac7b0 3-379f-4568-ac06-8bd5cb1ac7b0 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2. Demand 3. Energy << Previous 1 2 3 Next >> Basic Information Utility name: Holy Cross Electric Assn, Inc Effective date: 2011/07/01 End date if known: Rate name: STREET, HIGHWAY AND AREA LIGHTING: 100 Watt HPS Sector: Lighting Description: This rate applies when all fixtures are mounted on Holy Cross wood poles, either primary or secondary. Source or reference: http://www.holycross.com/about-us/rates-charges Source Parent: Comments Applicability Demand (kW) Minimum (kW): Maximum (kW): History (months): Energy (kWh) Minimum (kWh): Maximum (kWh): History (months):

469

Data:D0f4ac6d-44e2-4291-93ac-7bad270f8d9b | Open Energy Information  

Open Energy Info (EERE)

ac6d-44e2-4291-93ac-7bad270f8d9b ac6d-44e2-4291-93ac-7bad270f8d9b No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2. Demand 3. Energy << Previous 1 2 3 Next >> Basic Information Utility name: Cooperative L&P Assn Lake Cnty Effective date: 2012/01/01 End date if known: Rate name: Heat Pumps Sector: Residential Description: Both Air-source and Ground-source heat pumps use either the dual fuel or general service rate, depending on if you install a back-up heating system. Note: General service rates apply until back up fuel system is installed and operational. Contact your local heating contractor for any equipment information. Source or reference: http://www.clpower.com/?p=14

470

Data:E710dbca-01f1-41b8-a2ac-9680233ac368 | Open Energy Information  

Open Energy Info (EERE)

dbca-01f1-41b8-a2ac-9680233ac368 dbca-01f1-41b8-a2ac-9680233ac368 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2. Demand 3. Energy << Previous 1 2 3 Next >> Basic Information Utility name: City of Stafford, Kansas (Utility Company) Effective date: End date if known: Rate name: E6 - 155 Horsepower Sector: Commercial Description: Source or reference: https://cas.sharepoint.illinoisstate.edu/grants/Sunshot/Lists/DATA%20ENTRY%20Rates%20Collected/Attachments/627/rate%20information%20for%20Stafford.pdf Source Parent: Comments Applicability Demand (kW) Minimum (kW): Maximum (kW): History (months): Energy (kWh) Minimum (kWh): Maximum (kWh): History (months): Service Voltage Minimum (V):

471

Data:Cd66912f-ac4c-4a5f-ac64-750948dd9b7f | Open Energy Information  

Open Energy Info (EERE)

2f-ac4c-4a5f-ac64-750948dd9b7f 2f-ac4c-4a5f-ac64-750948dd9b7f No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2. Demand 3. Energy << Previous 1 2 3 Next >> Basic Information Utility name: Farmers' Electric Coop, Inc (New Mexico) Effective date: 2010/05/01 End date if known: Rate name: Small Commercial Sector: Commercial Description: Source or reference: Rate Binder#8 (Illinois State University) Source Parent: Comments Applicability Demand (kW) Minimum (kW): Maximum (kW): History (months): Energy (kWh) Minimum (kWh): Maximum (kWh): History (months): Service Voltage Minimum (V): Maximum (V): Character of Service Voltage Category: Phase Wiring: << Previous 1 2 3 Next >> << Previous

472

Toward a simple molecular understanding of sum frequency generation at air-water interfaces  

Science Conference Proceedings (OSTI)

Second-order vibrational spectroscopies successfully isolate signals from interfaces, but they report on intermolecular structure in a complicated and indirect way. Here we adapt a perspective on vibrational response developed for bulk spectroscopies to explore the microscopic fluctuations to which sum frequency generation (SFG), a popular surface-specific measurement, is most sensitive. We focus exclusively on inhomogeneous broadening of spectral susceptibilities for OH stretching of HOD as a dilute solute in D{sub 2}O. Exploiting a simple connection between vibrational frequency shifts and an electric field variable, we identify several functions of molecular orientation whose averages govern SFG. The frequency-dependence of these quantities is well captured by a pair of averages, involving alignment of OH and OD bonds with the surface normal at corresponding values of the electric field. The approximate form we obtain for SFG susceptibility highlights a dramatic sensitivity to the way a simulated liquid slab is partitioned for calculating second-order response.

Noah-Vanhoucke, Joyce; Smith, Jared D.; Geissler, Phillip L.

2009-01-13T23:59:59.000Z

473

Extremely high frequency RF effects on electronics.  

SciTech Connect

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.

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

474

Utility of Variable Speed Drives for Fish Protection at Cooling Water Intakes  

Science Conference Proceedings (OSTI)

This report reviews the utility of a variable frequency drive (VFD) for reducing cooling water flow and potentially the extent of impingement and entrainment of fish and shellfish at power plant cooling water intakes. Reduction of impingement and entrainment at cooling water intakes is the objective of Clean Water Act 316(b) requirements that are being developed by the U.S. Environmental Protection Agency (EPA).

2010-06-03T23:59:59.000Z

475

Guide to the Industrial Application of Motors and Variable-Speed Drives  

Science Conference Proceedings (OSTI)

This application guide is intended to aid in screening, selecting, and procuring specification processes for variable frequency drive (VFD) installations. It also is intended to provide a comprehensive up-to-date assessment of opportunities to save energy and improve power quality performance with state-of-the-art VFD technologies. The document supplies background information on electric motors and applications, describes VFD topologies, and details procurement specifications and application consideratio...

2001-09-27T23:59:59.000Z

476

Free and Forced Variability of the Tropical Atlantic Ocean: Role of the Wind–Evaporation–Sea Surface Temperature Feedback  

Science Conference Proceedings (OSTI)

The role of the wind–evaporation–sea surface temperature (WES) feedback in the low-frequency natural variability of the tropical Atlantic is studied using an atmospheric global climate model—the NCAR Community Climate Model, version 3 (CCM3)—...

Salil Mahajan; R. Saravanan; Ping Chang

2010-11-01T23:59:59.000Z

477

Multiperiodicity, modulations and flip-flops in variable star light curves I. Carrier fit method  

E-Print Network (OSTI)

The light curves of variable stars are commonly described using simple trigonometric models, that make use of the assumption that the model parameters are constant in time. This assumption, however, is often violated, and consequently, time series models with components that vary slowly in time are of great interest. In this paper we introduce a class of data analysis and visualization methods which can be applied in many different contexts of variable star research, for example spotted stars, variables showing the Blazhko effect, and the spin-down of rapid rotators. The methods proposed are of explorative type, and can be of significant aid when performing a more thorough data analysis and interpretation with a more conventional method.Our methods are based on a straightforward decomposition of the input time series into a fast "clocking" periodicity and smooth modulating curves. The fast frequency, referred to as the carrier frequency, can be obtained from earlier observations (for instance in the case of photometric data the period can be obtained from independently measured radial velocities), postulated using some simple physical principles (Keplerian rotation laws in accretion disks), or estimated from the data as a certain mean frequency. The smooth modulating curves are described by trigonometric polynomials or splines. The data approximation procedures are based on standard computational packages implementing simple or constrained least-squares fit-type algorithms.

J. Pelt; N. Olspert; M. J. Mantere; I. Tuominen

2011-09-12T23:59:59.000Z

478

Transport AC loss in high temperature superconducting coils  

E-Print Network (OSTI)

, and the world’s population continues to grow, our existing methods for energy supply and usage are clearly unsustainable. In developed industrialised nations, such as the UK and the US, the industrial sector uses about one third of all energy consumed [2... superconducting coil is found to be significantly large, and this will reduce the efficiency of the device in which it is utilised, par- ticularly when the loss is reflected back to room temperature by including the refrigeration cost. Many existing AC loss...

Ainslie, Mark

2012-05-08T23:59:59.000Z

479

dc-to-ac power converter for fuel cell system  

SciTech Connect

As the interface between fuel cells and the utility line, a self-commutated inverter is preferred to a line-commutated inverter because of its easy controllability. Using the gate turn off (GTO) thyristors, this inverter can have high efficiency and simple circuit configurations. This paper describes the design features and test results of the dc-to-ac power converter, which is principally composed of four-phase transistor chopper and 12-pulse GTO inverter, for a 50kW experimental fuel cell power system. Furthermore, new GTO inverter which improves the circuit efficiency is presented. Special emphasis is placed on a detailed analysis and evaluation of this GTO inverter.

Kawabata, T.; Asaeda, T.; Hamasaki, Y.; Yutani, T.

1983-10-01T23:59:59.000Z

480

ISM band to U-NII band frequency transverter and method of frequency transversion  

DOE Patents (OSTI)

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.

Stepp, Jeffrey David (Grandview, MO); Hensley, Dale (Grandview, MO)

2006-09-12T23:59:59.000Z

Note: This page contains sample records for the topic "ac variable frequency" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

ISM band to U-NII band frequency transverter and method of frequency transversion  

DOE Patents (OSTI)

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.

Stepp, Jeffrey David (Grandview, MO); Hensley, Dale (Grandview, MO)

2006-04-04T23:59:59.000Z

482

Nine New Variable Stars in Camelopardalis  

E-Print Network (OSTI)

Nine new short period variable stars have been discovered in the direction of the open cluster Cr464 in Camelopardalis. The field was observed using Tzec Maun Observatory's telescope AP180. Two new variable stars were classified as pulsating stars (RRab and RRc types). The other seven stars are binary systems. One of them is of ELL-type, four binaries were recognized as EW-type, and two systems are rather short period EA-type binaries. All new variables were registered in the VSX catalogue.

Virnina, Natalia A

2013-01-01T23:59:59.000Z

483

High frequency inductive lamp and power oscillator  

DOE Patents (OSTI)

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.

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

484

High frequency inductive lamp and power oscillator  

DOE Patents (OSTI)

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.

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

485

Variability of EGRET Gamma-Ray Sources  

E-Print Network (OSTI)

The variability of the high-energy gamma ray sources in the Third EGRET catalog is analyzed by a new method. We re-analyze the EGRET data to calculate a likelihood function for the flux of each source in each observation, both for detections and upper limits. These functions can be combined in a uniform manner with a simple model of the flux distribution to characterize the flux variation by a confidence interval for the relative standard deviation of the flux. The main result is a table of these values for almost all the cataloged sources. As expected, the identified pulsars are steady emitters and the blazars are mostly highly variable. The unidentified sources are heterogeneous, with greater variation at higher Galactic latitude. There is an indication that pulsar wind nebulae are associated with variable sources. There is a population of variable sources along the Galactic plane, concentrated in the inner spiral arms.

P. L. Nolan; W. F. Tompkins; I. A. Grenier; P. F. Michelson

2003-07-10T23:59:59.000Z

486

Interannual Variability of Northwest Australian Tropical Cyclones  

Science Conference Proceedings (OSTI)

Tropical cyclone (TC) activity over the southeast Indian Ocean has been studied far less than other TC basins, such as the North Atlantic and northwest Pacific. The authors examine the interannual TC variability of the northwest Australian (NWAUS)...

Kevin H. Goebbert; Lance M. Leslie

2010-09-01T23:59:59.000Z

487

Variability of Southern Ocean Jets Near Topography  

Science Conference Proceedings (OSTI)

The interaction of jets with topography in the Southern Ocean is investigated using 19 years of altimetry data. In particular, the “jet jumping” mode of variability, by which two or more jets passing close to the same topographic feature show ...

Christopher C. Chapman; Rosemary Morrow

488

Experiments Concerning Variability among Subjective Analyses  

Science Conference Proceedings (OSTI)

The variability of subjective (hand) analyses is explored by examining the results of two synoptic laboratory experiments. Two groups of analysts participated in the first experiment, one consisting of 13 senior meteorology students (1977), the ...

Dayton G. Vincent; Herbert Borenstein

1980-10-01T23:59:59.000Z

489

Tropical Convective Variability as 1/f Noise  

Science Conference Proceedings (OSTI)

Evidence is presented that the tropical convective variability behaves as 1/f noise for a 1–30-day period. This behavior is shown by analyzing the time series of convective available potential energy, which measures the degree of convective ...

Jun-Ichi Yano; Klaus Fraedrich; Richard Blender

2001-09-01T23:59:59.000Z

490

Optimizing Crop Insurance under Climate Variability  

Science Conference Proceedings (OSTI)

This paper studies the selection of optimal crop insurance under climate variability and fluctuating market prices. A model was designed to minimize farmers’ expected losses (including insurance costs) while using the conditional-value-at-risk ...

Juan Liu; Chunhua Men; Victor E. Cabrera; Stan Uryasev; Clyde W. Fraisse

2008-10-01T23:59:59.000Z

491

Variable volume architecture : expanding the boundary  

E-Print Network (OSTI)

Research into the creation of a Variable Volume Architecture is explored through a series of proposals and projects. An argument is established to develop the means and methods of achieving an architecture of transformation. ...

Saheba, Asheshh (Asheshh Mohit), 1972-

2001-01-01T23:59:59.000Z

492

Backscatter Differential Phase—Estimation and Variability  

Science Conference Proceedings (OSTI)

On the basis of simulations and observations made with polarimetric radars operating at X, C, and S bands, the backscatter differential phase ? has been explored; ? has been identified as an important polarimetric variable that should not be ...

Silke Trömel; Matthew R. Kumjian; Alexander V. Ryzhkov; Clemens Simmer; Malte Diederich

2013-11-01T23:59:59.000Z

493

Spatial Variability of Outgoing Longwave Radiation  

Science Conference Proceedings (OSTI)

Data from the Earth Radiation Budget Experiment scanning radiometer aboard the NOAA-9 operational meteorological satellite are used to investigate the spatial variability of outgoing longwave radiation (OLR). Daily and monthly radiation maps at ...

G. Louis Smith; David Rutan

1994-07-01T23:59:59.000Z

494

Climate Variability and Sugarcane Yield in Louisiana  

Science Conference Proceedings (OSTI)

This paper seeks to understand the role that climate variability has on annual yield of sugarcane in Louisiana. Unique features of sugarcane growth in Louisiana and nonclimatic, yield-influencing factors make this goal an interesting and ...

David Greenland

2005-11-01T23:59:59.000Z

495

AC Loss Reduction in Filamentized YBCO Coated Conductors with Virtual Transverse Cross-cuts  

Science Conference Proceedings (OSTI)

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.

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

496

Frequency Instability Problems in North American Interconnections  

NLE Websites -- All DOE Office Websites (Extended Search)

Frequency Instability Problems in Frequency Instability Problems in North American Interconnections May 1, 2011 DOE/NETL-2011/1473 Frequency Instability Problems in North American Interconnections Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement,

497

Frequency Scanned Interferometry for ILC Tracker Alignment  

E-Print Network (OSTI)

In this paper, we report high-precision absolute distance and vibration measurements performed with frequency scanned interferometry. Absolute distance was determined by counting the interference fringes produced while scanning the laser frequency. High-finesse Fabry-Perot interferometers were used to determine frequency changes during scanning. A dual-laser scanning technique was used to cancel drift errors to improve the absolute distance measurement precision. A new dual-channel FSI demonstration system is also presented which is an interim stage toward practical application of multi-channel distance measurement. Under realistic conditions, a precision of 0.3 microns was achieved for an absolute distance of 0.57 meters. A possible optical alignment system for a silicon tracker is also presented.

Hai-Jun Yang; Tianxiang Chen; Keith Riles

2011-09-12T23:59:59.000Z

498

Demodulation circuit for AC motor current spectral analysis  

DOE Patents (OSTI)

A motor current analysis method for the remote, noninvasive inspection of electric motor-operated systems. Synchronous amplitude demodulation and phase demodulation circuits are used singly and in combination along with a frequency analyzer to produce improved spectral analysis of load-induced frequencies present in the electric current flowing in a motor-driven system.

Hendrix, Donald E. (Oak Ridge, TN); Smith, Stephen F. (Knoxville, TN)

1990-12-18T23:59:59.000Z

499

Electrojet-independent ionospheric extremely low frequency/very low frequency wave generation by powerful high frequency waves  

Science Conference Proceedings (OSTI)

Results of extremely low frequency/very low frequency (ELF/VLF) wave generation by intensity-modulated high frequency (HF) heaters of 3.2 MHz in Gakona, Alaska, near local solar noon during a geomagnetic quiet time, are presented to support an electrojet-independent ELF/VLF wave generation mechanism. The modulation was set by splitting the HF transmitter array into two subarrays; one was run at cw full power and the other run alternatively at 50% and 100% power modulation by rectangular waves of 2.02, 5, 8, and 13 kHz. The most effective generation was from the X-mode heater with 100% modulation. While the 8 kHz radiation has the largest wave amplitude, the spectral intensity of the radiation increases with the modulation frequency, i.e., 13 kHz line is the strongest. Ionograms recorded significant virtual height spread of the O-mode sounding echoes. The patterns of the spreads and the changes of the second and third hop virtual height traces caused by the O/X-mode heaters are distinctively different, evidencing that it is due to differently polarized density irregularities generated by the filamentation instability of the O/X-mode HF heaters.

Kuo, Spencer [Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, New York 11201 (United States); Snyder, Arnold [NorthWest Research Associates, P.O. Box 530, Stockton Springs, Maine 04981 (United States); Chang, Chia-Lie [BAE Systems-Technology Solutions, 2000 North 15th Street, Suite 1100, Arlington, Virginia 22201-2627 (United States)

2010-08-15T23:59:59.000Z

500

Seismic isolation systems with distinct multiple frequencies  

DOE Patents (OSTI)

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.

Wu, Ting-shu (Downers Grove, IL); Seidensticker, Ralph W. (Wheaton, IL)

1990-01-01T23:59:59.000Z