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Note: This page contains sample records for the topic "tip-speed ratio-the speed" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Sandia National Laboratories: high tip-speed ratios  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia,evaluatingfull moduleresources gridstandbyhigh tip-speed

2

Effect of Tip-Speed Constraints on the Optimized Design of a Wind Turbine  

SciTech Connect (OSTI)

This study investigates the effect of tip-velocity constraints on system levelized cost of energy (LCOE). The results indicate that a change in maximum tip speed from 80 to 100~m/s could produce a 32% decrease in gearbox weight (a 33% reduction in cost) which would result in an overall reduction of 1%-9% in system LCOE depending on the design approach. Three 100~m/s design cases were considered including a low tip-speed ratio/high-solidity rotor design, a high tip-speed ratio/ low-solidity rotor design, and finally a flexible blade design in which a high tip-speed ratio was used along with removing the tip deflection constraint on the rotor design. In all three cases, the significant reduction in gearbox weight caused by the higher tip-speed and lower overall gear ratio was counterbalanced by increased weights for the rotor and/or other drivetrain components and the tower. As a result, the increased costs of either the rotor or drivetrain components offset the overall reduction in turbine costs from down-sizing the gearbox. Other system costs were not significantly affected, whereas energy production was slightly reduced in the 100~m/s case low tip-speed ratio case and increased in the high tip-speed ratio case. This resulted in system cost of energy reductions moving from the 80~m/s design to the 100~m/s designs of 1.2% for the low tip-speed ratio, 4.6% for the high tip-speed ratio, and 9.5% for the final flexible case (the latter result is optimistic because the impact of deflection of the flexible blade on power production was not modeled). Overall, the results demonstrate that there is a trade-off in system design between the maximum tip velocity and the overall wind plant cost of energy, and there are many trade-offs within the overall system in designing a turbine for a high maximum tip velocity.

Dykes, K.; Resor, B.; Platt, A.; Guo, Y.; Ning, A.; King, R.; Parsons, T.; Petch, D.; Veers, P.

2014-10-01T23:59:59.000Z

3

File:Table for Tip Speed Intervals of Length.pdf | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision has beenFfe2fb55-352f-473b-a2dd-50ae8b27f0a6 NoSanEnergy0).pdfLongValleyInformationSkystreamTip Speed

4

File:Tip Speed Lesson Plan.pdf | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision has beenFfe2fb55-352f-473b-a2dd-50ae8b27f0a6Theoretical vs Actual Data Lesson Plan .pdf Jump to:Tip Speed

5

Analysis of a teetered, variable-speed rotor: final report  

SciTech Connect (OSTI)

A computer model of a horizontal axis wind turbine (HOOT) with four structural degrees of freedom has been derived and verified. The four degrees of freedom include flapwise motion of the blades, teeter motion, and variable rotor speed. Options for the variable rotor speed include synchronous, induction, and constant-tip speed generator models with either start, stop, or normal operations. Verification is made by comparison with analytical solutions and mean and cyclic ESI-80 data. The Veers full-field turbulence model is used as a wind input for a synchronous and induction generator test case during normal operation. As a result of the comparison, it is concluded that the computer model can be used to predict accurately mean and cyclic loads with a turbulent wind input. 47 refs., 19 figs.

Weber, T.L.; Wilson, R.E.; Walker, S.N. (Oregon State Univ., Corvallis, OR (USA). Dept. of Mechanical Engineering) [Oregon State Univ., Corvallis, OR (USA). Dept. of Mechanical Engineering

1991-06-01T23:59:59.000Z

6

Effects of turbulence on power generation for variable-speed wind turbines  

SciTech Connect (OSTI)

One of the primary advantages of variable-speed wind turbines over fixed-speed turbines should be improved aerodynamic efficiency. With variable-speed generation, in order to maintain a constant ratio of wind speed to tip speed, the wind turbine changes rotor speed as the wind speed changes. In this paper we compare a stall-controlled, variable-speed wind turbine to a fixed-speed turbine. The focus of this paper is to investigate the effects of variable speed on energy capture and its ability to control peak power. We also show the impact of turbulence on energy capture in moderate winds. In this report, we use a dynamic simulator to apply different winds to a wind turbine model. This model incorporates typical inertial and aerodynamic performance characteristics. From this study we found a control strategy that makes it possible to operate a stall-controlled turbine using variable speed to optimize energy capture and to control peak power. We also found that turbulence does not have a significant impact on energy capture.

Muljadi, E.; Butterfield, C.P.; Buhl, M.L. Jr.

1996-11-01T23:59:59.000Z

7

Performance of propeller wind turbines  

SciTech Connect (OSTI)

Presented herein is a parametric study of the performance of propeller wind turbines with realistic drag/lift ratios. Calculations were made using the complete Glauert vortex blade element theory in annular streamtube elements with the complete turbine performance being the sum of the elemental results up to a specified tip speed ratio. The objective here is to exhibit a new computational technique which yields performance directly when tangential speed ratio and section aerodynamic characteristics are specified. It was found that for a tip speed ratio of 4, turbines with drag/lift ratios of 0.00 and 0.01 had power coefficients of 0.575 and 0.55, respectively. The off-design performance of the finite drag/lift was far better than that of their zero drag counterparts, except in a + or - 20% region about the design conditions. Tolerance to off-design operation increased with decreasing tip speed ratios so that the annual energy capture for tip speed ratios between 2 and 4 was about 87% of the ideal turbine value. The results are intended to provide a basis for re-evaluation of the power range classes of fixed pitch turbines and design tip speed ratios.

Wortman, A.

1983-11-01T23:59:59.000Z

8

Vibration Analysis of a Vertical Axis Wind Turbine Blade , S.Tullis 2  

E-Print Network [OSTI]

Vibration Analysis of a Vertical Axis Wind Turbine Blade K. Mc Laren 1 , S.Tullis 2 and S.Ziada 3 1 vibration source of a small-scale vertical axis wind turbine currently undergoing field-testing. The turbine at a blade-tip speed ratio (the ratio of the blade rotational velocity to the ambient wind velocity) of 1

Tullis, Stephen

9

Research in Aeroelasticity EFP-2006 Edited by Christian Bak  

E-Print Network [OSTI]

and analysis of the dynamics of a hydraulic pitch system for a 5 MW wind turbine was carried out. It was shown-01 Sponsorship: Danish Energy Authorities Cover : From Figure 7-4, page 76 in Chapter 7 "Dynamics of a hydraulic and the results indicated a range of optimum tip speed ratios. The use of winglets for wind turbine rotor

10

Effectiveness of speed trailers on low-speed urban roadways  

E-Print Network [OSTI]

Efforts are being made to use speed management methods to match operating speeds to posted speeds and to reduce the variability in vehicle speeds. The effectiveness of many different methods of speed management has not been documented. This thesis...

Perrillo, Kerry Victoria

1997-01-01T23:59:59.000Z

11

Balancing of high speed, flexible rotating shafts across critical speeds  

E-Print Network [OSTI]

this is equivalent to eliminating certain sen- sors. Once the influence coefficient matrix is square, the solution procedure is exactly that of the single speed case. The computed balance weights should now null the rotor vibration at the sensor ports which were... critical speed, The Sin- gle Speed and the Exact Point-Speed techniques were determined to be relatively ineffective over this speed range; however, the Least Squares procedure yields a dramatic decrease in rotor vibration over the entire speed range...

White, Gary Paul

1977-01-01T23:59:59.000Z

12

Combination of Speed Stroke Grinding and High Speed Grinding with Regard to Sustainability  

E-Print Network [OSTI]

Combination of Speed Stroke Grinding and High Speed Grindinghow the combination of speed stroke grinding and high speed4] Inasaki, I. , 1988, Speed Stroke Grinding of Advanced

Linke, Barbara; M. Duscha; F. Klocke; Dornfeld, David

2011-01-01T23:59:59.000Z

13

High speed door assembly  

DOE Patents [OSTI]

A high speed door assembly is described, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

Shapiro, C.

1993-04-27T23:59:59.000Z

14

High speed door assembly  

DOE Patents [OSTI]

A high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

Shapiro, Carolyn (Idaho Falls, ID)

1993-01-01T23:59:59.000Z

15

High speed door assembly  

SciTech Connect (OSTI)

This invention is comprised of a high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

Shapiro, C.

1991-12-31T23:59:59.000Z

16

Two-speed transaxle  

DOE Patents [OSTI]

Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

Kalns, Ilmars (Northville, MI)

1981-01-01T23:59:59.000Z

17

1International High Speed Rail Conference 19642064 High Speed Rail  

E-Print Network [OSTI]

1International High Speed Rail Conference 1964­2064 High Speed Rail: Celebrating Ambition 2014 by the Birmingham Centre for Railway Research and Education Conference programme 8 ­10 December 2014 Kindly supported by: #12;2 International High Speed Rail Conference Monday 8 December 12:00 ­ 12:50 Registration

Birmingham, University of

18

Control device for vehicle speed  

SciTech Connect (OSTI)

This patent describes a control device for vehicle speed comprising: a throttle driving means operatively coupled to a throttle valve of a vehicle; a set switch means for commanding memorization of the vehicle speed; a resume switch means for commanding read of the vehicle speed; a vehicle speed detecting means for generating a signal in accordance with the vehicle speed; a vehicle speed memory; an electronical control means for memorizing in the vehicle speed memory vehicle speed information corresponding to the signal obtained from the vehicle speed detecting means in response to actuation of the set switch means. The control means is also for reading out the content of the vehicle speed memory in response to actuation of the resume switch means to control the throttle driving means in accordance with the read-out content; a power supply means for supplying power to the electronical control means; and a power supply control switch means for controlling supply of power to the electronical control means in response to the state of at least one of the set switch means and the resume switch means and the state of the electronical control means. The improvement described here comprises the electronical control means sets the power supply control switch means into such a state that supply of power to the electronical control means is turned OFF, when vehicle speed information is not memorized in the vehicle speed memory.

Kawata, S.; Hyodo, H.

1987-03-03T23:59:59.000Z

19

High speed transient sampler  

DOE Patents [OSTI]

A high speed sampler comprises a meandered sample transmission line for transmitting an input signal, a straight strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates along the transmission lines. The sampling gates comprise a four terminal diode bridge having a first strobe resistor connected from a first terminal of the bridge to the positive strobe line, a second strobe resistor coupled from the third terminal of the bridge to the negative strobe line, a tap connected to the second terminal of the bridge and to the sample transmission line, and a sample holding capacitor connected to the fourth terminal of the bridge. The resistance of the first and second strobe resistors is much higher than the signal transmission line impedance in the preferred system. This results in a sampling gate which applies a very small load on the sample transmission line and on the strobe generator. The sample holding capacitor is implemented using a smaller capacitor and a larger capacitor isolated from the smaller capacitor by resistance. The high speed sampler of the present invention is also characterized by other optimizations, including transmission line tap compensation, stepped impedance strobe line, a multi-layer physical layout, and unique strobe generator design. A plurality of banks of such samplers are controlled for concatenated or interleaved sample intervals to achieve long sample lengths or short sample spacing.

McEwan, Thomas E. (Livermore, CA)

1995-01-01T23:59:59.000Z

20

High speed transient sampler  

DOE Patents [OSTI]

A high speed sampler comprises a meandered sample transmission line for transmitting an input signal, a straight strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates along the transmission lines. The sampling gates comprise a four terminal diode bridge having a first strobe resistor connected from a first terminal of the bridge to the positive strobe line, a second strobe resistor coupled from the third terminal of the bridge to the negative strobe line, a tap connected to the second terminal of the bridge and to the sample transmission line, and a sample holding capacitor connected to the fourth terminal of the bridge. The resistance of the first and second strobe resistors is much higher than the signal transmission line impedance in the preferred system. This results in a sampling gate which applies a very small load on the sample transmission line and on the strobe generator. The sample holding capacitor is implemented using a smaller capacitor and a larger capacitor isolated from the smaller capacitor by resistance. The high speed sampler of the present invention is also characterized by other optimizations, including transmission line tap compensation, stepped impedance strobe line, a multi-layer physical layout, and unique strobe generator design. A plurality of banks of such samplers are controlled for concatenated or interleaved sample intervals to achieve long sample lengths or short sample spacing. 17 figs.

McEwan, T.E.

1995-11-28T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Stability Improvement of Wind Farms using Shunt and Series Compensation  

E-Print Network [OSTI]

Air density, Rotor effective wind speed. A Swept area of the turbine blade. Tip speed ratio. Cp, Torsion damping. Tm, Tae, Te Mechanical, Aerodynamic, and Electrical torque. Lm, Lrr Mutual inductance

Pota, Himanshu Roy

22

Preliminary design and viability consideration of external, shroud-based stators in wind turbine generators  

E-Print Network [OSTI]

Horizontal-axis wind turbine designs often included gearboxes or large direct-drive generators to compensate for the low peripheral speeds of the turbine hub. To take advantage of high blade tip speeds, an alternative ...

Shoemaker-Trejo, Nathaniel (Nathaniel Joseph)

2012-01-01T23:59:59.000Z

23

Adjustable Speed Drive Industrial Applications  

E-Print Network [OSTI]

Electric motors are significant users of electricity in the United States. Approximately 66 percent of the total electricity in the U.S. is used by electric motors. Electronic adjustable speed drives (ASDs) can save energy, lower maintenance cost...

Poole, J. N.

24

Renewable variable speed hybrid system  

E-Print Network [OSTI]

At present many remote and Island communities rely solely on diesel powered generators to provide electricity. Diesel fuel is both expensive and polluting and the constant speed operation of the diesel engine is inefficient. ...

Stott, Paul Anthony

2010-01-01T23:59:59.000Z

25

Forecasting wind speed financial return  

E-Print Network [OSTI]

The prediction of wind speed is very important when dealing with the production of energy through wind turbines. In this paper, we show a new nonparametric model, based on semi-Markov chains, to predict wind speed. Particularly we use an indexed semi-Markov model that has been shown to be able to reproduce accurately the statistical behavior of wind speed. The model is used to forecast, one step ahead, wind speed. In order to check the validity of the model we show, as indicator of goodness, the root mean square error and mean absolute error between real data and predicted ones. We also compare our forecasting results with those of a persistence model. At last, we show an application of the model to predict financial indicators like the Internal Rate of Return, Duration and Convexity.

D'Amico, Guglielmo; Prattico, Flavio

2013-01-01T23:59:59.000Z

26

Combination of Speed Stroke Grinding and High Speed Grinding with Regard to Sustainability  

E-Print Network [OSTI]

Stress Model for Speed Stroke Grinding of Hardened SteelStresses in Speed Stroke Grinding via FEA Simulation andCombination of Speed Stroke Grinding and High Speed Grinding

Linke, Barbara; Duscha, Michael; Klocke, Fritz; Dornfeld, David

2011-01-01T23:59:59.000Z

27

Sustainably Priced Energy Enterprise Development (SPEED) Goals  

Broader source: Energy.gov [DOE]

Vermont's Sustainably Priced Energy Enterprise Development (SPEED) Program was created by legislation in 2005 to promote renewable energy development. The SPEED program itself is not a renewable...

28

Speeding Up Zeolite Evaluation for Carbon Capture  

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

Speeding Up Zeolite Evaluation for Carbon Capture Speeding Up Zeolite Evaluation for Carbon Capture Zeolite.png Schematic of an important class of porous materials known as...

29

Dual-speed wind turbine generation  

SciTech Connect (OSTI)

Induction generator has been used since the early development of utility-scale wind turbine generation. An induction generator is the generator of choice because of its ruggedness and low cost. With an induction generator, the operating speed of the wind turbine is limited to a narrow range (almost constant speed). Dual- speed operation can be accomplished by using an induction generator with two different sets of winding configurations or by using a dual output drive train to drive two induction generators with two different rated speeds. With single-speed operation, the wind turbine operates at different power coefficients (Cp) as the wind speed varies. Operation at maximum Cp can occur only at a single wind speed. However, if the wind speed.varies across a wider range, the operating Cp will vary significantly. Dual-speed operation has the advantage of enabling the wind turbine to operate at near maximum Cp over a wider range of wind speeds. Thus, annual energy production can be increased. The dual-speed mode may generate less energy than a variable-speed mode; nevertheless, it offers an alternative which captures more energy than single-speed operation. In this paper, dual-speed operation of a wind turbine is investigated. Annual energy production is compared between single-speed and dual-speed operation. One type of control algorithm for dual-speed operation is proposed. Some results from a dynamic simulation will be presented to show how the control algorithm works as the wind turbine is exposed to varying wind speeds.

Muljadi, E.; Butterfield, C.P. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Handman, D. [Flowind Corp., San Rafael, CA (United States)] [Flowind Corp., San Rafael, CA (United States)

1996-10-01T23:59:59.000Z

30

Speed control with end cushion for high speed air cylinder  

DOE Patents [OSTI]

A high speed air cylinder in which the longitudinal movement of the piston within the air cylinder tube is controlled by pressurizing the air cylinder tube on the accelerating side of the piston and releasing pressure at a controlled rate on the decelerating side of the piston. The invention also includes a method for determining the pressure required on both the accelerating and decelerating sides of the piston to move the piston with a given load through a predetermined distance at the desired velocity, bringing the piston to rest safely without piston bounce at the end of its complete stroke.

Stevens, Wayne W. (Idaho Falls, ID); Solbrig, Charles W. (Idaho Falls, ID)

1991-01-01T23:59:59.000Z

31

Passive aeroelastic tailoring of wind turbine blades : a numerical analysis  

E-Print Network [OSTI]

This research aims to have an impact towards a sustainable energy supply. In wind power generation losses occur at tip speed ratios which the rotor was not designed for. Since the ideal blade shape changes nonlinearly with ...

Deilmann, Christian

2009-01-01T23:59:59.000Z

32

High speed optical quantum random number generation  

E-Print Network [OSTI]

.3351 (2009). 6. I. Reidler, Y. Aviad, M. Rosenbluh, and I. Kanter, "Ultrahigh-speed random number generation

Weinfurter, Harald

33

Channel coding for high speed links  

E-Print Network [OSTI]

This thesis explores the benefit of channel coding for high-speed backplane or chip-to-chip interconnects, referred to as the high-speed links. Although both power-constrained and bandwidth-limited, the high-speed links ...

Blitvic, Natasa

2008-01-01T23:59:59.000Z

34

Better haul roads speed operations  

SciTech Connect (OSTI)

Modern trucks and scrapers are manufactured to standards of increasingly larger size and degree of sophistication, and to get the greatest return in productivity it is necessary to have good haul roads. Good haul roads can reduce fuel consumption, increase vehicle speed, reduce wear and tear on machinery, and improve safety. The paper describes aspects of haul road maintenance, including levelling and repairing of the surface, reducing rolling resistance, super-elevating curves, eliminating reverse curves and controlling dust. The design of haul roads is also covered.

Not Available

1982-03-01T23:59:59.000Z

35

Ultra-high speed vacuum pump system with first stage turbofan and second stage turbomolecular pump  

DOE Patents [OSTI]

An ultra-high speed vacuum pump evacuation system includes a first stage ultra-high speed turbofan and a second stage conventional turbomolecular pump. The turbofan is either connected in series to a chamber to be evacuated, or is optionally disposed entirely within the chamber. The turbofan employs large diameter rotor blades operating at high linear blade velocity to impart an ultra-high pumping speed to a fluid. The second stage turbomolecular pump is fluidly connected downstream from the first stage turbofan. In operation, the first stage turbofan operates in a pre-existing vacuum, with the fluid asserting only small axial forces upon the rotor blades. The turbofan imparts a velocity to fluid particles towards an outlet at a high volume rate, but moderate compression ratio. The second stage conventional turbomolecular pump then compresses the fluid to pressures for evacuation by a roughing pump.

Jostlein, Hans

2006-04-04T23:59:59.000Z

36

High speed sampler and demultiplexer  

DOE Patents [OSTI]

A high speed sampling demultiplexer based on a plurality of sampler banks, each bank comprising a sample transmission line for transmitting an input signal, a strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates at respective positions along the sample transmission line for sampling the input signal in response to the strobe signal. Strobe control circuitry is coupled to the plurality of banks, and supplies a sequence of bank strobe signals to the strobe transmission lines in each of the plurality of banks, and includes circuits for controlling the timing of the bank strobe signals among the banks of samplers. Input circuitry is included for supplying the input signal to be sampled to the plurality of sample transmission lines in the respective banks. The strobe control circuitry can repetitively strobe the plurality of banks of samplers such that the banks of samplers are cycled to create a long sample length. Second tier demultiplexing circuitry is coupled to each of the samplers in the plurality of banks. The second tier demultiplexing circuitry senses the sample taken by the corresponding sampler each time the bank in which the sampler is found is strobed. A plurality of such samples can be stored by the second tier demultiplexing circuitry for later processing. Repetitive sampling with the high speed transient sampler induces an effect known as ``strobe kickout``. The sample transmission lines include structures which reduce strobe kickout to acceptable levels, generally 60 dB below the signal, by absorbing the kickout pulses before the next sampling repetition. 16 figs.

McEwan, T.E.

1995-12-26T23:59:59.000Z

37

High speed sampler and demultiplexer  

DOE Patents [OSTI]

A high speed sampling demultiplexer based on a plurality of sampler banks, each bank comprising a sample transmission line for transmitting an input signal, a strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates at respective positions along the sample transmission line for sampling the input signal in response to the strobe signal. Strobe control circuitry is coupled to the plurality of banks, and supplies a sequence of bank strobe signals to the strobe transmission lines in each of the plurality of banks, and includes circuits for controlling the timing of the bank strobe signals among the banks of samplers. Input circuitry is included for supplying the input signal to be sampled to the plurality of sample transmission lines in the respective banks. The strobe control circuitry can repetitively strobe the plurality of banks of samplers such that the banks of samplers are cycled to create a long sample length. Second tier demultiplexing circuitry is coupled to each of the samplers in the plurality of banks. The second tier demultiplexing circuitry senses the sample taken by the corresponding sampler each time the bank in which the sampler is found is strobed. A plurality of such samples can be stored by the second tier demultiplexing circuitry for later processing. Repetitive sampling with the high speed transient sampler induces an effect known as "strobe kickout". The sample transmission lines include structures which reduce strobe kickout to acceptable levels, generally 60 dB below the signal, by absorbing the kickout pulses before the next sampling repetition.

McEwan, Thomas E. (Livermore, CA)

1995-01-01T23:59:59.000Z

38

Active control system for high speed windmills  

DOE Patents [OSTI]

A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed.

Avery, Don E. (45-437 Akimala St., Honolulu, HI 96744)

1988-01-01T23:59:59.000Z

39

Active control system for high speed windmills  

DOE Patents [OSTI]

A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed. 4 figs.

Avery, D.E.

1988-01-12T23:59:59.000Z

40

Wind Speed Prediction Via Time Series Modeling.  

E-Print Network [OSTI]

??Projected construction of nearby wind farms motivates this study of statistical forecasting of wind speed, for which accurate prediction is critically important to the fluid (more)

Alexander, Daniel

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

High speed imager test station  

DOE Patents [OSTI]

A test station enables the performance of a solid state imager (herein called a focal plane array or FPA) to be determined at high image frame rates. A programmable waveform generator is adapted to generate clock pulses at determinable rates for clock light-induced charges from a FPA. The FPA is mounted on an imager header board for placing the imager in operable proximity to level shifters for receiving the clock pulses and outputting pulses effective to clock charge from the pixels forming the FPA. Each of the clock level shifters is driven by leading and trailing edge portions of the clock pulses to reduce power dissipation in the FPA. Analog circuits receive output charge pulses clocked from the FPA pixels. The analog circuits condition the charge pulses to cancel noise in the pulses and to determine and hold a peak value of the charge for digitizing. A high speed digitizer receives the peak signal value and outputs a digital representation of each one of the charge pulses. A video system then displays an image associated with the digital representation of the output charge pulses clocked from the FPA. In one embodiment, the FPA image is formatted to a standard video format for display on conventional video equipment. 12 figs.

Yates, G.J.; Albright, K.L.; Turko, B.T.

1995-11-14T23:59:59.000Z

42

Relationship between design speed and operating speed at horizontal curves on suburban arterials  

E-Print Network [OSTI]

RELATIONSHIP BETWEEN DESIGN SPEED AND OPERATING SPEED AT HORIZONTAL CURVES ON SUBURBAN ARTERIALS A Thesis by CARL BRIAN SHAMBURGER Submitted to the OIIice of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1995 Major Subject: Civil Engineering RELATIONSHIP BETWEEN DESIGN SPEED AND OPERATING SPEED AT HORIZONTAL CURVES ON SUBURBAN ARTERIALS A Thesis by CARL BRIAN SHAMBURGER Submitted to Texas A&M University...

Shamburger, Carl Brian

2012-06-07T23:59:59.000Z

43

Variable Speed Pumping for Level Control  

E-Print Network [OSTI]

The purpose of this paper is to describe an application of variable speed pumping to level control of an industrial process. Topics include a comparison of the process using control valves with a variable speed system, an energy savings and cost...

Vasel, M.

1982-01-01T23:59:59.000Z

44

Measuring the Impacts of Speed Reduction Technologies  

E-Print Network [OSTI]

-Seoud, Edward Anderson #12;Background Identified as a problem area Sharp curve & excessive speed High crash;Comparison of Mean Zones - Southbound, Commercial Vehicles 45 46 47 48 49 50 51 52 53 54 55 -1300 -1100 -900-70 Speed Category Before After #12;At nearest rest area

Bertini, Robert L.

45

Optimization of a Small Passive Wind Turbine Generator with Multiobjective Genetic Algorithms  

E-Print Network [OSTI]

: Multiobjective Optimization, Genetic Algorithms, Wind Energy, Vertical Axis Wind Turbine hal-00763673,version1 achieved by controlling the speed of a Wind Turbine Generator (WTG). In particular, the rotor speed should vary in accordance with the wind speed by maintaining the tip speed ratio to the value that maximizes

Paris-Sud XI, Université de

46

Wind Speed Forecasting for Power System Operation  

E-Print Network [OSTI]

In order to support large-scale integration of wind power into current electric energy system, accurate wind speed forecasting is essential, because the high variation and limited predictability of wind pose profound challenges to the power system...

Zhu, Xinxin

2013-07-22T23:59:59.000Z

47

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...

Fishel, F. D.

1979-01-01T23:59:59.000Z

48

Low Speed Unsteady Aerodynamics Soumitra Banerjee*  

E-Print Network [OSTI]

Low Speed Unsteady Aerodynamics Soumitra Banerjee* Virginia Polytechnic Institute and State University, Blacksburg, Virginia, 24061 Unsteady aerodynamics is the study of fluid flow, where the flow field changes with time. The unsteadiness is significant in many aerodynamic applications; few examples

Patil, Mayuresh

49

Speed selection for coupled wave equations  

E-Print Network [OSTI]

We discuss models for coupled wave equations describing interacting fields, focusing on the speed of travelling wave solutions. In particular, we propose a general mechanism for selecting and tuning the speed of the corresponding (multi-component) travelling wave solutions under certain physical conditions. A number of physical models (molecular chains, coupled Josephson junctions, propagation of kinks in chains of adsorbed atoms and domain walls) are considered as examples.

Mariano Cadoni; Giuseppe Gaeta

2015-01-13T23:59:59.000Z

50

Wind speed vertical distribution at Mt. Graham  

E-Print Network [OSTI]

The characterization of the wind speed vertical distribution V(h) is fundamental for an astronomical site for many different reasons: (1) the wind speed shear contributes to trigger optical turbulence in the whole troposphere, (2) a few of the astroclimatic parameters such as the wavefront coherence time (tau_0) depends directly on V(h), (3) the equivalent velocity V_0, controlling the frequency at which the adaptive optics systems have to run to work properly, depends on the vertical distribution of the wind speed and optical turbulence. Also, a too strong wind speed near the ground can introduce vibrations in the telescope structures. The wind speed at a precise pressure (200 hPa) has frequently been used to retrieve indications concerning the tau_0 and the frequency limits imposed to all instrumentation based on adaptive optics systems, but more recently it has been proved that V_200 (wind speed at 200 hPa) alone is not sufficient to provide exhaustive elements concerning this topic and that the vertical d...

Hagelin, S; Lascaux, F

2010-01-01T23:59:59.000Z

51

A Multivariate Analysis of Freeway Speed and Headway Data  

E-Print Network [OSTI]

key process is the generation of entry vehicle speeds and vehicle arrival times. It is helpful to find desirable mathematical distributions to model individual speed and headway values, because the individual vehicle speed and arrival time...

Zou, Yajie

2013-11-11T23:59:59.000Z

52

A study of the effect of posted speed limits on traffic speeds  

E-Print Network [OSTI]

. 60 C 50 JJ 40 Be fore After tti 0 U Ol DO 4) ts U U C 4) C U 4) I ) 4) 0 40 30 0 20 10 4 t 13. 0 14. 0 Ni 1 epos ts - S. H. 36 Location D-12 - West Columbia CI Be fore IED After 15. 0 FIGURE V. 11, LUSTRAT10N OF A... Distribution Curves for No Change in the Original 60-Nile-Par-Hour Speed Limit in District 12. Each Curve Represents Data Prom 7 Spot Speed Studies in 4 Locations. 37 12. 13. Cumulative Speed Distribution Curves for a Change in Speed Limit From 60 to 55...

Rowan, Neilon Joyce

2012-06-07T23:59:59.000Z

53

Variable Speed Pumping: A Guide to Successful Applications -...  

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

Variable Speed Pumping: A Guide to Successful Applications - Executive Summary Variable Speed Pumping: A Guide to Successful Applications - Executive Summary This document...

54

Energy Department Announces $10 Million to Speed Enhanced Geothermal...  

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

to Speed Enhanced Geothermal Systems into the Market Energy Department Announces 10 Million to Speed Enhanced Geothermal Systems into the Market February 24, 2014 - 11:46am...

55

Advanced Variable Speed Air-Source Integrated Heat Pump 2013...  

Energy Savers [EERE]

Advanced Variable Speed Air-Source Integrated Heat Pump 2013 Peer Review Advanced Variable Speed Air-Source Integrated Heat Pump 2013 Peer Review Emerging Technologies Project for...

56

Measure Guideline: Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings  

SciTech Connect (OSTI)

The report evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provide a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.

Hunt, A.; Easley, S.

2012-05-01T23:59:59.000Z

57

Variable speed operation of generators with rotor-speed feedback in wind power applications  

SciTech Connect (OSTI)

The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable-speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable-speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy we analyze uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. in extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

Muljadi, E.; Butterfield, C.P.; Migliore, P.

1995-11-01T23:59:59.000Z

58

Variable speed operation of generators with rotor-speed feedback in wind power applications  

SciTech Connect (OSTI)

The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable-speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable-speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy analyzed uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. In extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

Muljadi, E.; Butterfield, C.P.; Migliore, P. [National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.

1996-10-01T23:59:59.000Z

59

Variable speed operation of generators with rotor-speed feedback in wind power applications  

SciTech Connect (OSTI)

The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up, and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy the authors analyze uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. In extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

Muljadi, E.; Butterfield, C.P.; Migliore, P. [National Renewable Energy Lab., Golden, CO (United States)

1996-11-01T23:59:59.000Z

60

Adjustable speed drive for residential applications  

SciTech Connect (OSTI)

This paper describes a demonstration of an adjustable speed drive suitable for use in residential applications such as compressors and fans in heat pumps, air conditioners, and refrigerators. The adjustable speed drive uses only a four-diode rectifier and a six-transistor six-diode inverter and does not require a source-frequency filter inductor or capacitor. Motor speed is adjusted with source-frequency phase control eliminating the switching loss and electromagnetic interference caused by the more commonly used high-frequency pulse-width modulation. Low source-current distortion and high power factor are obtained at a full-load operating point which is found using a parametric analysis.

Jungreis, A.M.; Kelley, A.W. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Electrical and Computer Engineering] [North Carolina State Univ., Raleigh, NC (United States). Dept. of Electrical and Computer Engineering

1995-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Pattern speed evolution and bar reformation  

E-Print Network [OSTI]

Bars in spiral galaxies can weaken through gas inflow towards the center, and angular momentum transfer. Several bar episodes can follow one another in the life of the galaxy, if sufficient gas is accreted from the intergalactic medium to revive young disks. Pattern speeds of the successive bars are different, due to mass concentration, or increased velocity dispersion of the remaining stellar component. In the same time, the spiral galaxy evolves in morphological type. Numerical simulations are presented, trying to correlate type and bar pattern speeds.

F. Combes

2008-11-05T23:59:59.000Z

62

Dynamic simulation of dual-speed wind turbine generation  

SciTech Connect (OSTI)

Induction generators have been used since the early development of utility-scale wind turbine generation. An induction generator is the generator of choice because of its ruggedness, and low cost. With an induction generator, the operating speed of the wind turbine is limited to a narrow range (almost constant speed). Dual- speed operation can be accomplished by using an induction generator with two different sets of winding configurations or by using two induction generators with two different rated speeds. With single- speed operation, the wind turbine operates at different power coefficients (Cp) as the wind speed varies. The operation at maximum Cp can occur only at a single wind speed. However, if the wind speed varies across a wider range, the operating Cp will vary significantly. Dual-speed operation has the advantage of enabling the wind turbine to operate at near maximum Cp over a wider range of wind-speeds. Thus, annual energy production can be increased. The dual-speed mode may generate less energy than a variable-speed mode; nevertheless, it offers an alternative to capture more energy than single-speed operation. In this paper, dual-speed operation of a wind turbine will be investigated. One type of control algorithm for dual- speed operation is proposed. Results from a dynamic simulation will be presented to show how the control algorithm works and how power, current and torque of the system vary as the wind turbine is exposed to varying wind speeds.

Muljadi, E.; Butterfield, C.P.

1996-10-01T23:59:59.000Z

63

On-chip high speed localized cooling using superlattice microrefrigerators  

E-Print Network [OSTI]

cooling, microrefrigerators, optoelectronics, superlattice,in high power, high-speed optoelectronics devices, and

Zhang, Y; Christofferson, J; Shakouri, A; Zeng, G H; Bowers, J E; Croke, E T

2006-01-01T23:59:59.000Z

64

CRYOPUMP MEASUREMENTS RELATING TO SAFETY, PUMPING SPEED, AND RADIATION OUTGASSING  

E-Print Network [OSTI]

Fast Gas Pulse Typical Data for Dynamic Pumping Speed Measurements with Deuterium Plan View of Reactor

Graham, W.G.

2011-01-01T23:59:59.000Z

65

Modeling and Control of a Marine Current Turbine Driven Doubly-Fed Induction Generator  

E-Print Network [OSTI]

--Marine current turbine, Doubly-Fed Induction Generator, modeling, control, Maximum Power Point Tracking current speed; = Tip speed ratio; s, (r) = Stator (rotor) index (superscripts); d, q = Synchronous leakage coefficient, = 1 ­ M2 /LsLr; r = Rotor position; (s) = Rotor electrical speed (electrical

Boyer, Edmond

66

3314 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 56, NO. 9, SEPTEMBER 2009 High-Order Sliding-Mode Control of  

E-Print Network [OSTI]

, Senior Member, IEEE Abstract--This paper deals with the power generation control in variable-speed wind-Mode Control of Variable-Speed Wind Turbines Brice Beltran, Tarek Ahmed-Ali, and Mohamed El Hachemi Benbouzid turbines. These systems have two oper- ation regions which depend on wind turbine tip speed ratio. A high

Paris-Sud XI, Université de

67

Detour : Los Angeles River Speed Cinema  

E-Print Network [OSTI]

We live in the culture of speed; everything is on its way to become a faster version of itself tomorrow if it is not already there today. Automobile and cinema are two inventions at the turn of the 20th Century that brought ...

Lee, Weifeng Victoria

2010-01-01T23:59:59.000Z

68

Average Rate Speed Scaling Nikhil Bansal1  

E-Print Network [OSTI]

energy. In this setting, the operating system must not only have a job selection policy to determine was deadline feasibility and the objective was to minimize the energy used. More precisely, each job i has of the speed to power function, this even spreading is energy optimal if the instance consists of only one job

Bunde, David

69

Average Rate Speed Scaling Nikhil Bansal  

E-Print Network [OSTI]

energy. In this setting, the operating system must not only have a job selection policy to determine was deadline feasibility and the objective was to minimize the energy used. More precisely, each job i has of the speed to power function, this even spreading is energy optimal if the instance consists of only one job

Bunde, David

70

Speed estimation using single loop detector outputs  

E-Print Network [OSTI]

...................................................................................10 2.1 Introduction ........................................................................................10 2.2 Vehicle Detectors ...............................................................................10 2.3 Description of the Speed....4 Hourly traffic volumes from the IH-35 test bed in Austin on Oct. 27, 2004 38 Fig 3.5 Layout of the simulated freeway section ...................................................... 41 Fig. 4.1 Average vehicle lengths over time...

Ye, Zhirui

2009-05-15T23:59:59.000Z

71

Speed estimation using single loop detector outputs  

E-Print Network [OSTI]

...................................................................................10 2.1 Introduction ........................................................................................10 2.2 Vehicle Detectors ...............................................................................10 2.3 Description of the Speed....4 Hourly traffic volumes from the IH-35 test bed in Austin on Oct. 27, 2004 38 Fig 3.5 Layout of the simulated freeway section ...................................................... 41 Fig. 4.1 Average vehicle lengths over time...

Ye, Zhirui

2008-10-10T23:59:59.000Z

72

Thermodynamics in variable speed of light theories  

E-Print Network [OSTI]

The perfect fluid in the context of a covariant variable speed of light theory proposed by J. Magueijo is studied. On the one hand the modified first law of thermodynamics together with a recipe to obtain equations of state are obtained. On the other hand the Newtonian limit is performed to obtain the nonrelativistic hydrostatic equilibrium equation for the theory. The results obtained are used to determine the time variation of the radius of Mercury induced by the variability of the speed of light ($c$), and the scalar contribution to the luminosity of white dwarfs. Using a bound for the change of that radius and combining it with an upper limit for the variation of the fine structure constant, a bound on the time variation of $c$ is set. An independent bound is obtained from luminosity estimates for Stein 2015B.

Juan Racker; Pablo Sisterna; Hector Vucetich

2009-11-30T23:59:59.000Z

73

Thermodynamics in variable speed of light theories  

SciTech Connect (OSTI)

The perfect fluid in the context of a covariant variable speed of light theory proposed by J. Magueijo is studied. On the one hand the modified first law of thermodynamics together with a recipe to obtain equations of state are obtained. On the other hand the Newtonian limit is performed to obtain the nonrelativistic hydrostatic equilibrium equation for the theory. The results obtained are used to determine the time variation of the radius of Mercury induced by the variability of the speed of light (c), and the scalar contribution to the luminosity of white dwarfs. Using a bound for the change of that radius and combining it with an upper limit for the variation of the fine structure constant, a bound on the time variation of c is set. An independent bound is obtained from luminosity estimates for Stein 2015B.

Racker, Juan [CONICET, Centro Atomico Bariloche, Avenida Bustillo 9500 (8400), San Carlos De Bariloche (Argentina); Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N (1900), La Plata (Argentina); Sisterna, Pablo [Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350 (7600), Mar del Plata (Argentina); Vucetich, Hector [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N (1900), La Plata (Argentina)

2009-10-15T23:59:59.000Z

74

Wind Speed Data Analysis using Wavelet Transform  

E-Print Network [OSTI]

AbstractRenewable energy systems are becoming a topic of great interest and investment in the world. In recent years wind power generation has experienced a very fast development in the whole world. For planning and successful implementations of good wind power plant projects, wind potential measurements are required. In these projects, of great importance is the effective choice of the micro location for wind potential measurements, installation of the measurement station with the appropriate measuring equipment, its maintenance and analysis of the gained data on wind potential characteristics. In this paper, a wavelet transform has been applied to analyze the wind speed data in the context of insight in the characteristics of the wind and the selection of suitable locations that could be the subject of a wind farm construction. This approach shows that it can be a useful tool in investigation of wind potential. KeywordsWind potential, Wind speed data, Wavelet transform.

S. Avdakovic; A. Lukac; A. Nuhanovic; M. Music

75

Gas Model of Gravitons with Light Speed  

E-Print Network [OSTI]

We first review some aspects of gravitational wave and the thermodynamic expression of Einstein field equations, these achieved conclusions allow people to think of Einstein's gravitational wave as a kind of sound wave in ordinary gas which propagates as an adiabatic compression wave. In the following, using the properties of photon gas in "white wall box", we find an analogous relationship between ordinary gas and photon gas through sound velocity formula. At last, by taking the ordinary gas as an intermediary, we find that gravitational wave is analogous to photon gas, or equally, gravitons are analogous to photons although they are different in some ways such as spins and coupling strengths, and these different properties don't affect their propagation speeds. Utilizing this analogous relationship, we achieve the gas model of gravitons and this model naturally gives out the light speed of gravitons

Ming Chen; Yong-Chang Huang

2014-06-17T23:59:59.000Z

76

Resonant speed meter for gravitational wave detection  

E-Print Network [OSTI]

Gravitational-wave detectors have been well developed and operated with high sensitivity. However, they still suffer from mirror displacement noise. In this paper, we propose a resonant speed meter, as a displacement noise-canceled configuration based on a ring-shaped synchronous recycling interferometer. The remarkable feature of this interferometer is that, at certain frequencies, gravitational-wave signals are amplified, while displacement noises are not.

Atsushi Nishizawa; Seiji Kawamura; Masa-aki Sakagami

2008-05-01T23:59:59.000Z

77

Data Capture Technique for High Speed Signaling  

DOE Patents [OSTI]

A data capture technique for high speed signaling to allow for optimal sampling of an asynchronous data stream. This technique allows for extremely high data rates and does not require that a clock be sent with the data as is done in source synchronous systems. The present invention also provides a hardware mechanism for automatically adjusting transmission delays for optimal two-bit simultaneous bi-directional (SiBiDi) signaling.

Barrett, Wayne Melvin (Rochester, MN); Chen, Dong (Croton On Hudson, NY); Coteus, Paul William (Yorktwon Heights, NY); Gara, Alan Gene (Mount Kisco, NY); Jackson, Rory (Eastchester, NY); Kopcsay, Gerard Vincent (Yorktown Hieghts, NY); Nathanson, Ben Jesse (Teaneck, NY); Vranas, Paylos Michael (Bedford Hills, NY); Takken, Todd E. (Brewster, NY)

2008-08-26T23:59:59.000Z

78

Energy curable compositions having improved cure speeds  

DOE Patents [OSTI]

The composition and method provide improved physical properties and cure speed of polyurethane precursors, with or without free radical polymerizable monomers or oligomers present, by use of a two component catalyst system. The resin blend can be activated with a latent organometallic catalyst combined with an organic peroxide which can be a hydroperoxide or an acyl peroxide to decrease the cure time while increasing the break energy and tangent modulus of the system.

Halm, L.W.

1993-05-18T23:59:59.000Z

79

Nationwide: Slashing Red Tape To Speed Solar Deployment for Homes...  

Energy Savers [EERE]

Slashing Red Tape To Speed Solar Deployment for Homes and Businesses Nationwide: Slashing Red Tape To Speed Solar Deployment for Homes and Businesses January 24, 2014 - 12:00am...

80

Economical Aspects of Adjustable Speed Drives in Pumping Systems  

E-Print Network [OSTI]

Speed variations of pumps have become increasingly popular as the technology to produce variable frequency drives has progressed. Variable speed drives have many advantages compared to throttle valves when it comes to regulation of flow. They offer...

Hovstadius, G.

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Speed Map for Autonomous Rovers over Rough Terrain  

E-Print Network [OSTI]

presented here: fuzzy logic, reactive control, and machineto speed control is to utilize fuzzy logic. Fuzzy logic wascontrol, this is a new area of research where reactive speed controller, fuzzy logic,

Loh, Jonathan Edau

2012-01-01T23:59:59.000Z

82

Excitation and control of a high-speed induction generator  

E-Print Network [OSTI]

This project investigates the use of a high speed, squirrel cage induction generator and power converter for producing DC electrical power onboard ships and submarines. Potential advantages of high speed induction generators ...

Englebretson, Steven Carl

2005-01-01T23:59:59.000Z

83

Wind speed PDF classification using Dirichlet mixtures Rudy CALIF1  

E-Print Network [OSTI]

Wind speed PDF classification using Dirichlet mixtures Rudy CALIF1 , Richard EMILION2 , Ted'Orléans), UMR CNRS 6628 Université d'Orléans, France. Abstract: Wind energy production is very sensitive to instantaneous wind speed fluctuations. Thus rapid variation of wind speed due to changes in the local

Paris-Sud XI, Université de

84

Estimation of Wind Speed in Connection to a Wind Turbine  

E-Print Network [OSTI]

Estimation of Wind Speed in Connection to a Wind Turbine X. Ma #3; , N. K. Poulsen #3; , H. Bindner y December 20, 1995 Abstract The wind speed varies over the rotor plane of wind turbine making the wind speed on the rotor plane will be estimated by using a wind turbine as a wind measuring device

85

Adult Football Helmet Detailed Ratings Riddell Revolution Speed  

E-Print Network [OSTI]

Adult Football Helmet Detailed Ratings May 2011 Riddell Revolution Speed Helmet ID SPEED1 SPEED2: A total of 10 adult football helmet models were evaluated using the STAR evaluation system for May 2011.397 0.350 0.322 Overall STAR 0.356 Very Good: Adult Football Helmet Detailed Ratings May 2011 #12

Lu, Chang

86

Deadline Scheduling and Power Management for Speed Bounded Processors  

E-Print Network [OSTI]

be scaled arbitrarily high (the infinite speed model), SOA can complete all jobs with reduced energy usage,15,23,24] enables a processor to vary the speed dynamically. Running a job slower reduces energy usage, but it takes online job scheduling with speed scaling and energy usage taken into consideration. The challenge arises

Wong, Prudence W.H.

87

Statistical Analysis of Environment Canada's Wind Speed Data  

E-Print Network [OSTI]

Statistical Analysis of Environment Canada's Wind Speed Data Someshwar Singh Department Brunswick-Fredericton New Brunswick, Canada Email: jtaylor@unb.ca Abstract--Wind energy utilities use wind. This paper reports on a study of the histories of wind speed forecasts and actual wind speed data available

Taylor, James H.

88

Ris-R-Report LIDAR Wind Speed Measurements from a  

E-Print Network [OSTI]

, the spinner axis's vertical tilt and the wind turbine's yaw relative to the mean wind speed direction: Data Files 54 Appendix B: Wind Speed Vertical Profile 55 Appendix C: Sonic Cup Comparison 59Risø-R-Report LIDAR Wind Speed Measurements from a Rotating Spinner: "SpinnerEx 2009" Nikolas

89

Low Speed Automation, a French Initiative  

E-Print Network [OSTI]

MIPS, 2 rue des frres Lumire,68093 Mulhouse-FRANCE Nowadays, vehicle safety is constantly increasing thanks to the improvement of vehicle passive and active safety. However, on a daily usage of the car, traffic jams remains a problem. With limited space for road infrastructure, automation of the driving task on specific situation seems to be a possible solution. The French project ABV, which stands for low speed automation, tries to demonstrate the feasibility of the concept and to prove the benefits. In this article, we describe the scientific background of the project and expected outputs. "Keywords: vehicle automation, shared control, environment sensing, data fusion;" 1.

Sbastien Glaser; Maurice Cour; Lydie Nouveliere; Alain Lambert; Fawzi Nashashibi; Jean-christophe Popieul; Benjamin Mourllion

90

Speed-line for 3D animation  

E-Print Network [OSTI]

Committee Members, Carol LaFayette John Keyser Head of Department, Mardelle Shepley December 2005 Major Subject: Visualization Sciences iii ABSTRACT Speed-Line for 3D Animation. (December 2005) Won Chan Song, B.F.A., Ringling School of Art and Design Chair... to thank my committee members, Prof. Carol LaFayette and Dr. John Keyser for their advice and feedback. My gratitude also goes to Hobart Chan for letting me borrow his car model, which saved me a huge amount of time when I was making an animation as a...

Song, Won Chan

2007-04-25T23:59:59.000Z

91

Effective speed of sound in phononic crystals  

E-Print Network [OSTI]

A new formula for the effective quasistatic speed of sound $c$ in 2D and 3D periodic materials is reported. The approach uses a monodromy-matrix operator to enable direct integration in one of the coordinates and exponentially fast convergence in others. As a result, the solution for $c$ has a more closed form than previous formulas. It significantly improves the efficiency and accuracy of evaluating $c$ for high-contrast composites as demonstrated by a 2D example with extreme behavior.

A. A. Kutsenko; A. L. Shuvalov; A. N. Norris

2011-06-27T23:59:59.000Z

92

Nuclear Speed-Dating | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratory | NationalJohnSecurityControls |NavyNuclear Speed-Dating Nuclear

93

MHL High Speed Cavitation | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 - 429Lacey,(MonasterLowell Point,ECO Auger < MHK TechnologiesMonofloathyTideSpeed

94

Speeding Up Zeolite Evaluation for Carbon Capture  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future |CarlosSpeakersSpectroscopy PrintSpeeding

95

Lensless magneto-optic speed sensor  

DOE Patents [OSTI]

Lensless magneto-optic speed sensor is disclosed. The construction of a viable Faraday sensor has been achieved. Multimode fiber bundles are used to collect the light. If coupled directly into a 100 or 200 {micro}m core fiber, light from a light emitting diode (LED) is sufficient to operate the sensor. In addition, LEDs ensure that no birefringence effects in the input fiber are possible, as the output from such light sources have random polarization. No lens is required since the large diameter optical fibers and thin crystals of materials having high Verdet constants (such as iron garnets) employed permit the collection of a substantial quantity of light. No coupler is required. The maximum amount of light which could reach a detector using a coupler is 25%, while the measured throughput of the fiber-optic bundle without a coupler is about 42%. All of the elements employed in the present sensor are planar, and no particular orientation of these elements is required. The present sensor operates over a wide range of distances from magnetic field sources, and observed signals are large. When a tone wheel is utilized, the signals are independent of wheel speed, and the modulation is observed to be about 75%. No sensitivity to bends in the input or output optical fiber leads was observed. Reliable operation was achieved down to zero frequency, or no wheel rotation. 5 figs.

Veeser, L.R.; Forman, P.R.; Rodriguez, P.J.

1998-02-17T23:59:59.000Z

96

Lensless Magneto-optic speed sensor  

DOE Patents [OSTI]

Lensless magneto-optic speed sensor. The construction of a viable Faraday sensor has been achieved. Multimode fiber bundles are used to collect the light. If coupled directly into a 100 or 200 .mu.m core fiber, light from a light emitting diode (LED) is sufficient to operate the sensor. In addition, LEDs ensure that no birefringence effects in the input fiber are possible, as the output from such light sources have random polarization. No lens is required since the large diameter optical fibers and thin crystals of materials having high Verdet constants (such as iron garnets) employed permit the collection of a substantial quantity of light. No coupler is required. The maximum amount of light which could reach a detector using a coupler is 25%, while the measured throughput of the fiber-optic bundle without a coupler is about 42%. All of the elements employed in the present sensor are planar, and no particular orientation of these elements is required. The present sensor operates over a wide range of distances from magnetic field sources, and observed signals are large. When a tone wheel is utilized, the signals are independent of wheel speed, and the modulation is observed to be about 75%. No sensitivity to bends in the input or output optical fiber leads was observed. Reliable operation was achieved down to zero frequency, or no wheel rotation.

Veeser, Lynn R. (Los Alamos, NM); Forman, Peter R. (Los Alamos, NM); Rodriguez, Patrick J. (Santa Fe, NM)

1998-01-01T23:59:59.000Z

97

Slow speed object detection for haul trucks  

SciTech Connect (OSTI)

Caterpillar integrates radar technology with its current camera based system. Caterpillar has developed the Integrated Object Detection System, a slow speed object detection system for mining haul trucks. Object detection is a system that aids the truck operator's awareness of their surroundings. The system consists of a color touch screen display along with medium- and short-range radar as well as cameras, harnesses and mounting hardware. It is integrated into the truck's Work Area Vision System (WAVS). After field testing in 2007, system commercialization began in 2008. Prototype systems are in operation in Australia, Utah and Arizona and the Integrated Object Detection System will be available in the fourth quarter of 2009 and on production trucks 785C, 789C, 793D and 797B. The article is adapted from a presentation by Mark Richards of Caterpillar to the Haulage & Loading 2009 conference, May, held in Phoenix, AZ. 1 fig., 5 photos.

NONE

2009-09-15T23:59:59.000Z

98

High Speed AB-Solar Sail  

E-Print Network [OSTI]

The Solar sail is a large thin film used to collect solar light pressure for moving of space apparatus. Unfortunately, the solar radiation pressure is very small about 9 mkN/sq.m at Earth's orbit. However, the light force significantly increases up to 0.2 - 0.35 N/sq.m near the Sun. The author offers his research on a new revolutionary highly reflective solar sail which flyby (after special maneuver) near Sun and attains velocity up to 400 km/sec and reaching far planets of the Solar system in short time or enable flights out of Solar system. New, highly reflective sail-mirror allows avoiding the strong heating of the solar sail. It may be useful for probes close to the Sun and Mercury and Venus. Key words: AB-solar sail, highly reflective solar sail, high speed propulsion.

Bolonkin, A

2007-01-01T23:59:59.000Z

99

High-speed electrical motor evaluation  

SciTech Connect (OSTI)

Under this task, MTI conducted a general review of state-of-the-art high-speed motors. The purpose of this review was to assess the operating parameters, limitations and performance of existing motor designs, and to establish commercial sources for a motor compatible with the requirements of the Brayton-cycle system. After the motor requirements were established, a list of motor types, manufacturers and designs capable of achieving the requisite performance was compiled. This list was based on an in-house evaluation of designs. Following the establishment of these options, a technical evaluation of the designs selected was conducted. In parallel with their evaluations, MTI focused on the establishment of commercial sources.

Not Available

1989-02-03T23:59:59.000Z

100

High Speed AB-Solar Sail  

E-Print Network [OSTI]

The Solar sail is a large thin film used to collect solar light pressure for moving of space apparatus. Unfortunately, the solar radiation pressure is very small about 9 mkN/sq.m at Earth's orbit. However, the light force significantly increases up to 0.2 - 0.35 N/sq.m near the Sun. The author offers his research on a new revolutionary highly reflective solar sail which flyby (after special maneuver) near Sun and attains velocity up to 400 km/sec and reaching far planets of the Solar system in short time or enable flights out of Solar system. New, highly reflective sail-mirror allows avoiding the strong heating of the solar sail. It may be useful for probes close to the Sun and Mercury and Venus. Key words: AB-solar sail, highly reflective solar sail, high speed propulsion.

A. Bolonkin

2007-01-08T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

High Speed/ Low Effluent Process for Ethanol  

SciTech Connect (OSTI)

n this project, BPI demonstrated a new ethanol fermentation technology, termed the High Speed/ Low Effluent (HS/LE) process on both lab and large pilot scale as it would apply to wet mill and/or dry mill corn ethanol production. The HS/LE process allows very rapid fermentations, with 18 to 22% sugar syrups converted to 9 to 11% ethanol beers in 6 to 12 hours using either a consecutive batch or continuous cascade implementation. This represents a 5 to 8X increase in fermentation speeds over conventional 72 hour batch fermentations which are the norm in the fuel ethanol industry today. The consecutive batch technology was demonstrated on a large pilot scale (4,800 L) in a dry mill corn ethanol plant near Cedar Rapids, IA (Xethanol Biofuels). The pilot demonstrated that 12 hour fermentations can be accomplished on an industrial scale in a non-sterile industrial environment. Other objectives met in this project included development of a Low Energy (LE) Distillation process which reduces the energy requirements for distillation from about 14,000 BTU/gal steam ($0.126/gal with natural gas @ $9.00 MCF) to as low as 0.40 KW/gal electrical requirements ($0.022/gal with electricity @ $0.055/KWH). BPI also worked on the development of processes that would allow application of the HS/LE fermentation process to dry mill ethanol plants. A High-Value Corn ethanol plant concept was developed to produce 1) corn germ/oil, 2) corn bran, 3) ethanol, 4) zein protein, and 5) nutritional protein, giving multiple higher value products from the incoming corn stream.

M. Clark Dale

2006-10-30T23:59:59.000Z

102

Wave Speed in the Macroscopic Extended Model for Ultrarelativistic Gases  

E-Print Network [OSTI]

An exact macroscopic extended model for ultrarelativistic gases, with an arbitrary number of moments, is present in the literature. Here we exploit equations determining wave speeds for that model. We find interesting results; for example, the whole system for their determination can be divided into independent subsystems and some, but not all, wave speeds are expressed by rational numbers. Moreover, the extraordinary property that these wave speeds for the macroscopic model are the same of those in the kinetic model, is proved.

F. Borghero; F. Demontis; S. Pennisi

2010-12-07T23:59:59.000Z

103

Effect of shrink fits on threshold speeds of rotordynamic instability  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 CHAPTER IV TEST APPARATUS . . . . 13 CHAPTER V RESULTS AND DISCUSSION . . . 17 17 30 42 42 47 5. 1 Rap Test. . 5. 2 Running Test 5. 3 Modeling and the Prcdiction of Threshold Speed of Instability.... . . . . . . . . . . . , . . . . . . . . . . . 5. 3. 1 Matching the Base Case. 5. 3. 2 Gunter's Prediction Using C, q 5. 3. 3 Modeling and Prediction of the Threshold Speed Using the XLTRC Code. . . . 51 5. 4 Prediction of the Onset Speed of Instability for a Tight Inteiference Fit...

Mir, MD. Mofazzal Hossain

2001-01-01T23:59:59.000Z

104

Boosting the Next Wave of Accelerators: New Technique Speeds...  

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

Boosting Accelerator Design Boosting the Next Wave of Accelerators New Technique Speeds Simulations by up to a Million-fold March 29, 2011 | Tags: Franklin, Nuclear Physics (NP)...

105

Surface wind speed distributions| Implications for climate and wind power.  

E-Print Network [OSTI]

?? Surface constituent and energy fluxes, and wind power depend non-linearly on wind speed and are sensitive to the tails of the wind distribution. Until (more)

Capps, Scott Blair

2010-01-01T23:59:59.000Z

106

New process speeds conversion of biomass to fuels  

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

Conversion of Biomass to Fuels New process speeds conversion of biomass to fuels Scientists made a major step forward recently towards transforming biomass-derived molecules into...

107

High-Speed, Stereoselective Polymerization for Renewable, Bio...  

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

Speed, Stereoselective Polymerization for Renewable, Bio-derived Plastics Fabrication of polymers and plastics from naturally renewable feedstocks offers the potential for a cost...

108

Very High Fuel Economy, Heavy Duty Truck, Narrow Range Speed...  

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

Heavy Duty Truck, Narrow Range Speed Engine, Optimized Via Unique Energy Recovery Turbines and Facilitated by High Efficiency Continuously Variable Drivetrain Very High Fuel...

109

Variable current speed controller for eddy current motors  

DOE Patents [OSTI]

A speed control system for eddy current motors is provided in which the current to the motor from a constant frequency power source is varied by comparing the actual motor speed signal with a setpoint speed signal to control the motor speed according to the selected setpoint speed. A three-phase variable voltage autotransformer is provided for controlling the voltage from a three-phase power supply. A corresponding plurality of current control resistors is provided in series with each phase of the autotransformer output connected to inputs of a three-phase motor. Each resistor is connected in parallel with a set of normally closed contacts of plurality of relays which are operated by control logic. A logic circuit compares the selected speed with the actual motor speed obtained from a digital tachometer monitoring the motor spindle speed and operated the relays to add or substract resistance equally in each phase of the motor input to vary the motor current to control the motor at the selected speed.

Gerth, H.L.; Bailey, J.M.; Casstevens, J.M.; Dixon, J.H.; Griffith, B.O.; Igou, R.E.

1982-03-12T23:59:59.000Z

110

High speed point derivative microseismic detector  

DOE Patents [OSTI]

A high speed microseismic event detector constructed in accordance with the present invention uses a point derivative comb to quickly and accurately detect microseismic events. Compressional and shear waves impinging upon microseismic receiver stations disposed to collect waves are converted into digital data and analyzed using a point derivative comb including assurance of quiet periods prior to declaration of microseismic events. If a sufficient number of quiet periods have passed, the square of a two point derivative of the incoming digital signal is compared to a trip level threshold exceeding the determined noise level to declare a valid trial event. The squaring of the derivative emphasizes the differences between noise and signal, and the valid event is preferably declared when the trip threshold has been exceeded over a temporal comb width to realize a comb over a given time period. Once a trial event has been declared, the event is verified through a spatial comb, which applies the temporal event comb to additional stations. The detector according to the present invention quickly and accurately detects initial compressional waves indicative of a microseismic event which typically exceed the ambient cultural noise level by a small amount, and distinguishes the waves from subsequent larger amplitude shear waves. 9 figs.

Uhl, J.E.; Warpinski, N.R.; Whetten, E.B.

1998-06-30T23:59:59.000Z

111

High speed point derivative microseismic detector  

DOE Patents [OSTI]

A high speed microseismic event detector constructed in accordance with the present invention uses a point derivative comb to quickly and accurately detect microseismic events. Compressional and shear waves impinging upon microseismic receiver stations disposed to collect waves are converted into digital data and analyzed using a point derivative comb including assurance of quiet periods prior to declaration of microseismic events. If a sufficient number of quiet periods have passed, the square of a two point derivative of the incoming digital signal is compared to a trip level threshold exceeding the determined noise level to declare a valid trial event. The squaring of the derivative emphasizes the differences between noise and signal, and the valid event is preferably declared when the trip threshold has been exceeded over a temporal comb width to realize a comb over a given time period. Once a trial event has been declared, the event is verified through a spatial comb, which applies the temporal event comb to additional stations. The detector according to the present invention quickly and accurately detects initial compressional waves indicative of a microseismic event which typically exceed the ambient cultural noise level by a small amount, and distinguishes the waves from subsequent larger amplitude shear waves.

Uhl, James Eugene (Albuquerque, NM); Warpinski, Norman Raymond (Albuquerque, NM); Whetten, Ernest Blayne (Albuquerque, NM)

1998-01-01T23:59:59.000Z

112

High speed exhaust gas recirculation valve  

DOE Patents [OSTI]

In order to minimize pollutants such as Nox, internal combustion engines typically include an exhaust gas recirculation (EGR) valve that can be used to redirect a portion of exhaust gases to an intake conduit, such as an intake manifold, so that the redirected exhaust gases will be recycled. It is desirable to have an EGR valve with fast-acting capabilities, and it is also desirable to have the EGR valve take up as little space as possible. An exhaust gas recirculation valve is provided that includes an exhaust passage tube, a valve element pivotally mounted within the exhaust passage tube, a linear actuator; and a gear train. The gear train includes a rack gear operatively connected to the linear actuator, and at least one rotatable gear meshing with the rack gear and operatively connected to the valve element to cause rotation of the valve element upon actuation of the linear actuator. The apparatus provides a highly compact package having a high-speed valve actuation capability.

Fensom, Rod (Peterborough, GB); Kidder, David J. (Peterborough, GB)

2005-01-18T23:59:59.000Z

113

0 Riso-R-434 Wind Speed and Direction  

E-Print Network [OSTI]

meteorological statistics for the area as it was considered a possible site for a nuclear power plant. \\ \\ Duringm I 0 Riso-R-434 t Wind Speed and Direction Changes due to Terrain Effects revealed-4000 Roskilde, Denmark May 1983 #12;RIS?-R-434 WIND SPEED AND DIRECTION CHANGES DUE TO TERRAIN EFFECTS

114

Multiprocessor Speed Scaling for Jobs with Arbitrary Sizes and Deadlines  

E-Print Network [OSTI]

or laptops with multi-core processors. A popular technology to reduce energy usage is dynamic speed scaling.H. Wong 1 Introduction Energy consumption has become an important concern in the design of modern energy, yet it takes longer to finish the job. The study of speed scaling was initiated by Yao et al. [6

Wong, Prudence W.H.

115

Structural vibration damping using lightweight, low-wave-speed media  

E-Print Network [OSTI]

Incorporation of a low-density, low-wave-speed medium (LWSM) into a structure yields significant damping if the speed of wave propagation in the medium is low enough for standing waves to arise in it. In this thesis, we ...

Verdirame, Justin Matthew, 1978-

2007-01-01T23:59:59.000Z

116

High Speed Rail in America Thomas Ducharme, Matt Schena,  

E-Print Network [OSTI]

International Airport. · Florida is on track to open one of America's first HSR express service between Tampa Situation of High Speed Rail · The US only has one high speed rail o Acela Which runs from Boston Airport congestion o By eliminating 900,000 city to city flights · Give access to cheaper long distance

Nagurney, Anna

117

Probabilistic Wind Speed Forecasting Using Ensembles and Bayesian Model Averaging  

E-Print Network [OSTI]

distribution; Numerical weather prediction; Skewed distribution; Truncated data; Wind energy. 1. INTRODUCTION- native. Purely statistical methods have been applied to short-range forecasts for wind speed only a fewProbabilistic Wind Speed Forecasting Using Ensembles and Bayesian Model Averaging J. Mc

Raftery, Adrian

118

Hydropower at flood control reservoirs - the variable speed option  

SciTech Connect (OSTI)

Application of hydroelectric turbine-generators to flood control has been limited due to the inability of a single turbine to operate efficiently over the wide head and flow ranges encountered. Multiple and different unit combinations have been applied to this problem, but the cost of the additional unit(s), powerhouse, and supporting facilities typically causes the project to become unfeasible. Variable speed operation can increase the operating range of a single turbine, and significantly improve efficiency over single speed units. This can make hydroelectric generation at flood control projects feasible. This paper presents a comparison of the application of variable speed units, two speed units, and single speed units at the Blue River Dam Hydroelectric Project. The project consists of the addition of a powerhouse to an existing Army Corps of Engineers flood control project. Efficiency data for the different types of units are compared and historical flow and release data are used in a computer model to simulate plant operation.

Laurence, K.; Yale, J. [Stone & Webster Engineering Corp., Denver, CO (United States)

1995-12-31T23:59:59.000Z

119

Non-Gaussianities of primordial perturbations and tensor sound speed  

E-Print Network [OSTI]

We investigate the relation between the non-Gaussianities of the primordial perturbations and the sound speed of the tensor perturbations, that is, the propagation speed of the gravitational waves. We find that the sound speed of the tensor perturbations is directly related not to the auto-bispectrum of the tensor perturbations but to the cross-bispectrum of the primordial perturbations, especially, the scalar-tensor-tensor bispectrum. This result is in sharp contrast with the case of the scalar (curvature) perturbations, where their reduced sound speed enhances their auto-bispectrum. Our findings indicate that the scalar-tensor-tensor bispectrum can be a powerful tool to probe the sound speed of the tensor perturbations.

Toshifumi Noumi; Masahide Yamaguchi

2014-03-24T23:59:59.000Z

120

High-speed electrochemistry using ultramicroelectrodes  

SciTech Connect (OSTI)

This research investigates the use of ultramicroelectrodes in performing electrochemistry on microsecond and nanosecond time scales. One purpose of this research was to look at new ways to apply ultramicroelectrodes to high speed experiments. Some of the aspects that are discussed in this thesis are: (a) A novel technique was developed for measuring currents on short time scales that involves conversion of the current to light using a light emitting diode and measuring the light intensity as a function of time using time correlated single photon counting (TCSPC). Computer processing of the light intensity data can convert this data back to current. The technique is capable of measurements on nanosecond time scales, but TCSPC requires tens or hundreds of millions of experiments to obtain a complete set of data and this frequently results in severe electrode fouling problems. (b) Potential step experiments were used instead of potential sweep experiments. Potential step experiments enable the separation in time of the faradaic and charging currents for chemical systems in which the faradaic impedance is greater than the uncompensated solution resistance. (c) For systems in which the faradaic impedance and uncompensated resistance are of the same order of magnitude, a computer simulation was developed which accounts for the interaction of the faradaic and double layer charging processes. (d) Application of short time scale experiments to the study of surface processes. Some processes studied in this work are the oxidation of clean platinum surfaces, electrode reactions of anthraquinone-2,6-disulfonic acid adsorbed on mercury, reductive hydrogen adsorption on platinum and double layer charging. (e) A study of the smallest available time constants was performed, taking into account non-idealities in the electrode such as stray capacitance and resistance of the electrode itself.

Walsh, M.R.

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Pitch-controlled variable-speed wind turbine generation  

SciTech Connect (OSTI)

Wind energy is a viable option to complement other types of pollution-free generation. In the early development of wind energy, the majority of wind turbines were operated at constant speed. Recently, the number of variable-speed wind turbines installed in wind farms has increased and more wind turbine manufacturers are making variable-speed wind turbines. This paper covers the operation of variable-speed wind turbines with pitch control. The system the authors considered is controlled to generate maximum energy while minimizing loads. The maximization of energy was only carried out on a static basis and only drive train loads were considered as a constraint. In medium wind speeds, the generator and power converter control the wind turbine to capture maximum energy from the wind. In the high wind speed region, the wind turbine is controlled to maintain the aerodynamic power produced by the wind turbine. Two methods to adjust the aerodynamic power were investigated: pitch control and generator load control, both of which are employed to control the operation of the wind turbine. The analysis and simulation shows that the wind turbine can be operated at its optimum energy capture while minimizing the load on the wind turbine for a wide range of wind speeds.

Muljadi, E.; Butterfield, C.P.

2000-03-01T23:59:59.000Z

122

Spatial and Temporal Patterns of Global Onshore Wind Speed Distribution  

SciTech Connect (OSTI)

Wind power, a renewable energy source, can play an important role in electrical energy generation. Information regarding wind energy potential is important both for energy related modeling and for decision-making in the policy community. While wind speed datasets with high spatial and temporal resolution are often ultimately used for detailed planning, simpler assumptions are often used in analysis work. An accurate representation of the wind speed frequency distribution is needed in order to properly characterize wind energy potential. Using a power density method, this study estimated global variation in wind parameters as fitted to a Weibull density function using NCEP/CFSR reanalysis data. The estimated Weibull distribution performs well in fitting the time series wind speed data at the global level according to R2, root mean square error, and power density error. The spatial, decadal, and seasonal patterns of wind speed distribution were then evaluated. We also analyzed the potential error in wind power estimation when a commonly assumed Rayleigh distribution (Weibull k = 2) is used. We find that the assumption of the same Weibull parameter across large regions can result in substantial errors. While large-scale wind speed data is often presented in the form of average wind speeds, these results highlight the need to also provide information on the wind speed distribution.

Zhou, Yuyu; Smith, Steven J.

2013-09-09T23:59:59.000Z

123

Critical speed measurements in the Tevatron cold compressors  

SciTech Connect (OSTI)

The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high energy operations. Nominal operating range for these compressors is 43,000 to 85,000 rpm. Past foil bearing failures prompted investigation to determine if critical speeds for operating compressors fall within operating range. Data acquisition hardware and software settings will be discussed for measuring liftoff, first critical and second critical speeds. Several tests provided comparisons between an optical displacement probe and accelerometer measurements. Vibration data and analysis of the 20 Tevatron ring cold compressors will be presented.

DeGraff, B.; Bossert, R.; Martinez, A.; Soyars, W.M.; /Fermilab

2006-01-01T23:59:59.000Z

124

Coal-fueled high-speed diesel engine development  

SciTech Connect (OSTI)

The objectives of this program are to study combustion feasibility by running Series 149 engine tests at high speeds with a fuel injection and combustion system designed for coal-water-slurry (CWS). The following criteria will be used to judge feasibility: (1) engine operation for sustained periods over the load range at speeds from 600 to 1900 rpm. The 149 engine for mine-haul trucks has a rated speed of 1900 rpm; (2) reasonable fuel economy and coal burnout rate; (3) reasonable cost of the engine design concept and CWS fuel compared to future oil prices.

Kakwani, R. M.; Winsor, R. E.; Ryan, III, T. W.; Schwalb, J. A.; Wahiduzzaman, S.; Wilson, Jr., R. P.

1991-11-01T23:59:59.000Z

125

New superlong-stroke slow-speed diesel  

SciTech Connect (OSTI)

Changes in the marine market and ship design in recent years created a demand for lower speed two-stroke engines. To meet this demand, MAN B W has added to its MC engine family the new S-versions, with cylinder bores of 80, 70, 60, 50 and 26 cm. The stroke-to-bore ratio was selected to be around 3.8:1, versus 3.2:1 for the previous L-versions. This basically reduced the engine speed to achieve a mean piston speed for improved propeller efficiency, increased the cylinder displacement for higher output, and improved the fuel consumption. 5 figs.

Kunberger, K.

1994-09-01T23:59:59.000Z

126

Engine control system having speed-based timing  

DOE Patents [OSTI]

A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a controller in communication with the actuator. The controller is configured to receive a signal indicative of engine speed and compare the engine speed signal with a desired engine speed. The controller is also configured to selectively regulate the actuator to adjust a timing of the engine valve to control an amount of air/fuel mixture delivered to the cylinder based on the comparison.

Willi, Martin L. (Dunlap, IL); Fiveland, Scott B. (Metamora, IL); Montgomery, David T. (Edelstein, IL); Gong, Weidong (Dunlap, IL)

2012-02-14T23:59:59.000Z

127

Taking Control of Green Speed Thomas A. Nikolai, Ph.D.  

E-Print Network [OSTI]

to know about green speed A lot of green speed misinformation Poor communication cited #1 problem GreenTaking Control of Green Speed Thomas A. Nikolai, Ph.D. The Doctor of Green Speed nikolait finds when requesting green speed help are.... #12;The 3 most common answers a superintendent finds when

128

Hydrodynamic evaluation of high-speed semi-SWATH vessels  

E-Print Network [OSTI]

High-speed semi-displacement vessels have enjoyed rapid development and widespread use over the past 25 years. Concurrent with their growth as viable commercial and naval platforms, has been the advancement of three-dimensional ...

Guttenplan, Adam (Adam David)

2007-01-01T23:59:59.000Z

129

A Machian Version of Einstein's Variable Speed of Light Theory  

E-Print Network [OSTI]

It is little known that while developing general relativity, Einstein's very first idea was a variable speed of light theory. Indeed spacetime curvature can be mimicked by a speed of light $c(r)$ that depends on the distribution of masses. Einstein's 1911 theory was considerably improved by Robert Dicke in 1957, but only recently the equivalence of the variable speed of light approach to the conventional formalism has been demonstrated (Broekaert, 2008). Using Green's functions, we show that Einstein's 1911 idea can be expressed in an analytic form, similar to the Poisson equation. Using heuristic arguments, we derive then a simple formula that directly relates curvature $w$ to the local speed of light, $w= -c^2 \\Delta \\frac{1}{c^2}$. In contrast to the conventional formulation, this allows for a Machian interpretation of general relativity and the gravitational constant $G$. Gravity, though described by local equations, would have its origin in all other masses in the universe.

Unzicker, Alexander

2015-01-01T23:59:59.000Z

130

A Machian Version of Einstein's Variable Speed of Light Theory  

E-Print Network [OSTI]

It is little known that while developing general relativity, Einstein's very first idea was a variable speed of light theory. Indeed spacetime curvature can be mimicked by a speed of light $c(r)$ that depends on the distribution of masses. Einstein's 1911 theory was considerably improved by Robert Dicke in 1957, but only recently the equivalence of the variable speed of light approach to the conventional formalism has been demonstrated (Broekaert, 2008). Using Green's functions, we show that Einstein's 1911 idea can be expressed in an analytic form, similar to the Poisson equation. Using heuristic arguments, we derive then a simple formula that directly relates curvature $w$ to the local speed of light, $w= -c^2 \\Delta \\frac{1}{c^2}$. In contrast to the conventional formulation, this allows for a Machian interpretation of general relativity and the gravitational constant $G$. Gravity, though described by local equations, would have its origin in all other masses in the universe.

Alexander Unzicker; Jan Preuss

2015-03-13T23:59:59.000Z

131

On advancement of high speed atomic force microscope technology  

E-Print Network [OSTI]

High speed atomic force microscopy (AFM) is a developing process in which nanoscale objects, such as crystal structures or strands of DNA, can be imaged at rates fast enough to watch processes as they occur. Although current ...

SooHoo, Kimberly E

2008-01-01T23:59:59.000Z

132

The effect of rainfall on freeway travel speeds  

E-Print Network [OSTI]

Studies on the effect of rainfall on freeway capacity found that capacity during wet conditions was 8 percent to 24 percent lower than average capacity during dry conditions. Based on these findings, Greenshield's speed-flow model was calibrated...

Holdener, Douglas Joseph

1997-01-01T23:59:59.000Z

133

Microsoft Word - idaho_wind_speed_summary.doc  

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

Ft. Hall, ID Sites Wheat Grass Ridge Average Wind Speeds Site 0001 (66 ft. (20m) tower, erected week of 11101, data started on 11201) N. 42 deg. 44.762', W. 112 deg. 41.011'...

134

A preliminary evaluation of a speed threshold incident detection algorithm  

E-Print Network [OSTI]

Traffic management centers can reduce emergency vehicle response time to incidents with immediate detection of incidents. Traffic management centers detect incidents by applying speed, occupancy, and/or volume loop detector data to an incident...

Kolb, Stephanie Lang

1996-01-01T23:59:59.000Z

135

automated speed enforcement: Topics by E-print Network  

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

Websites Summary: of a partial automation since they act on the control part of the vehicle. This increasing automationABV- A Low Speed Automation Project to Study the...

136

adjustable speed drives: Topics by E-print Network  

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

Websites Summary: of a partial automation since they act on the control part of the vehicle. This increasing automationABV- A Low Speed Automation Project to Study the...

137

adjustable speed drive: Topics by E-print Network  

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

Websites Summary: of a partial automation since they act on the control part of the vehicle. This increasing automationABV- A Low Speed Automation Project to Study the...

138

Probabilistic Wind Speed Forecasting using Ensembles and Bayesian Model Averaging  

E-Print Network [OSTI]

is to issue deterministic forecasts based on numerical weather prediction models. Uncertainty canProbabilistic Wind Speed Forecasting using Ensembles and Bayesian Model Averaging J. Mc discretization than is seen in other weather quantities. The prevailing paradigm in weather forecasting

Washington at Seattle, University of

139

High speed imaging of transient non-Newtonian fluid phenomena  

E-Print Network [OSTI]

In this thesis, I investigate the utility of high speed imaging for gaining scientific insight into the nature of short-duration transient fluid phenomena, specifically applied to the Kaye effect. The Kaye effect, noted ...

Gallup, Benjamin H. (Benjamin Hodsdon), 1982-

2004-01-01T23:59:59.000Z

140

High Speed Flywheels for Integrated Energy Storage and Attitude Control  

E-Print Network [OSTI]

High Speed Flywheels for Integrated Energy Storage and Attitude Control Christopher D. Hall. Decomposition of the space of internal torques separates the attitude control functionfrom the energy storage simultaneously performing energy storage and extraction operations. 1 Introduction The power engineering

Hall, Christopher D.

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

A Unified View on Speeded Categorization Hongbin Gu 1  

E-Print Network [OSTI]

A Unified View on Speeded Categorization Hongbin Gu 1 Chuanshu Ji 2 1 Introduction The research of Psychiatry, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; hongbin

Ji, Chuanshu

142

Effects of various inefficiencies in rowing on shell speed  

E-Print Network [OSTI]

First order predictions were made in determining the effects of various sources of inefficiency in rowing on shell speed. These predictions were then tested using a MATLAB model of the rowing stroke. The model simulates ...

Young, Stephen F., Jr

2009-01-01T23:59:59.000Z

143

RESEARCH ARTICLE Controlling speed and direction during interception  

E-Print Network [OSTI]

. Turning rate was controlled using a steering wheel and speed was controlled using a foot pedal (Wann and Land 2000), braking (Lee 1976; Yilmaz and Warren 1995), and fly ball catching (Chapman 1968

144

A high-speed hysteresis motor spindle for machining applications  

E-Print Network [OSTI]

An analysis of suitable drive technologies for use in a new high-speed machining spindle was performed to determine critical research areas. The focus is on a hysteresis motor topology using a solid, inherently-balanced ...

Bayless, Jacob D. (Jacob Daniel)

2014-01-01T23:59:59.000Z

145

Rotary-linear axes for high speed machining  

E-Print Network [OSTI]

This thesis presents the design, analysis, fabrication, and control of a rotary-linear axis; this axis is a key subsystem for high speed, 5-axis machine tools intended for fabricating centimeter-scale parts. The rotary-linear ...

Liebman, Michael Kevin, 1974-

2001-01-01T23:59:59.000Z

146

Microsoft Word - utah_wind_speed_summary.doc  

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

Jeff Anderson Site Castle Valley, Utah Average Wind Speeds Site 0006 (66 ft. (20m) tower, data started on 110601, data ended 112102) N. 38.635 deg., W. 109.397 deg. Elevation...

147

Design of high temperature high speed electromagnetic axial thrust bearing  

E-Print Network [OSTI]

DESIGN OF HIGH TEMPERATURE HIGH SPEED ELECTROMAGNETIC AXIAL THRUST BEARING A Thesis by MOHAMMAD WAQAR MOHIUDDIN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 2002 Major Subject: Mechanical Engineering DESIGN OF HIGH TEMPERATURE HIGH SPEED ELECTROMAGNETIC AXIAL THRUST BEARING A Thesis by MOHAMMAD WAQAR MOHIUDDIN Submitted to Texas A&M University in partial fulfillment...

Mohiuddin, Mohammad Waqar

2002-01-01T23:59:59.000Z

148

Energy and Reliability Considerations For Adjustable Speed Driven Pumps  

E-Print Network [OSTI]

ENERGY AND RELIABILITY CONSIDERATIONS FOR ADJUSTABLE SPEED DRIVEN PUMPS Don Casada Senior Development Associate ABSTRACT Centrifugal devices such as pumps, fans, and compressors follow a general set of speed affinity laws: Q2 = QI *( N z... there is no static head, the system head, like the pump head, is proportional to the velocity, or flow rate, squared. As a result. the pump affinity laws also indicate how the pump and system will work together to define the operating point in such a system...

Casada, D.

149

An evaluation of inductance loop detectors for speed measurement accuracy  

E-Print Network [OSTI]

AN EVALUATION OF INDUCTANCE LOOP DETECTORS FOR SPEED MEASUREMENT ACCURACY A Thesis by BRIAN PATRICK CRONIN Submitted to the OfBce of Graduate Studies of Texas AJkM University in partial fulSllment of the requirements for the degree of MASTER... OF SCIENCE December 1994 Major Subject: Civil Engineering AN EVALUATION OF INDUCTANCE LOOP DETECTORS FOR SPEED MEASUREMENT ACCURACY A Thesis by BRIAN PATRICK CRONIN Submitted to Texas ~M University in partial fulfillment of the requirements...

Cronin, Brian Patrick

2012-06-07T23:59:59.000Z

150

The Speed of Light as a Dilaton Field  

E-Print Network [OSTI]

Through dimensional analysis, eliminating the physical time, we identify the speed of light as a dilaton field. This leads to a restmass zero, spin zero gauge field which we call the speedon field. The complete Lagrangian for gravitational, electromagnetic and speedon field interactions with a charged scalar field, representing matter, is given. We then find solutions for the gravitational-electromagnetic-speedon field equations. This then gives an expression for the speed of light.

Walter Wyss

1997-12-09T23:59:59.000Z

151

A Low Order Model for Vertical Axis Wind Turbines Isaac M. Asher  

E-Print Network [OSTI]

A Low Order Model for Vertical Axis Wind Turbines Isaac M. Asher , Mark Drela and Jaime Peraire and performance prediction of vertical axis wind turbines is presented. The model uses a 2D hybrid dynamic vortex taken into account. Fast convergence is obtained for a large range of solidity and tip speed ratio

Peraire, Jaime

152

Toward Controlled Wind Farm Output: Adjustable Power Filtering  

E-Print Network [OSTI]

wind energy is extracted by the turbine blades. CP depends on the tip-speed ratio, , defined as = Rh structure for a fully-rated converter interfaced wind turbine. A singular perturbations decomposition the static curve that describes the aerodynamic conversion of energy by the bladed turbine rotor

Lehn, Peter W.

153

On-line implementation of an adaptive speed filter and its experimental demonstration  

E-Print Network [OSTI]

previously developed neural network speed filter is implemented for on-line induction motor speed estimation. The speed filter is constructed using a combination of five neural networks. A neural networks framework developed in this work is used to construct...

Abdul, Anis Mohamed

2012-06-07T23:59:59.000Z

154

E-Print Network 3.0 - ac adjustable speed Sample Search Results  

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

speed wind turbine concept 50 4.1 Variable speed wind turbine... of a variable speed wind turbine with DFIG 54 4.4 Doubly-fed induction generator control 57 4.4.1 System......

155

E-Print Network 3.0 - adjustable speed ac Sample Search Results  

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

speed wind turbine concept 50 4.1 Variable speed wind turbine... of a variable speed wind turbine with DFIG 54 4.4 Doubly-fed induction generator control 57 4.4.1 System......

156

Cloud speed impact on solar variability scaling ?? Application to the wavelet variability model  

E-Print Network [OSTI]

Kleissl, J. , 2013. Deriving cloud velocity from an array ofCloud Speed Impact on Solar Variability Scaling -this work, we determine from cloud speeds. Cloud simulator

Lave, Matthew; Kleissl, Jan

2013-01-01T23:59:59.000Z

157

Low Wind Speed Technology Phase II: Investigation of the Application of Medium-Voltage Variable-Speed Drive Technology to Improve the Cost of Energy from Low Wind Speed Turbines; Behnke, Erdman and Whitaker Engineering, Inc.  

SciTech Connect (OSTI)

This fact sheet describes a subcontract with Behnke, Erdman & Whitaker Engineering, Inc. to test the feasibility of applying medium-voltage variable-speed drive technology to low wind speed turbines.

Not Available

2006-03-01T23:59:59.000Z

158

High-Speed Cylindrical Collapse of Two Perfect Fluids  

E-Print Network [OSTI]

In this paper, the study of the gravitational collapse of cylindrically distributed two perfect fluid system has been carried out. It is assumed that the collapsing speeds of the two fluids are very large. We explore this condition by using the high-speed approximation scheme. There arise two cases, i.e., bounded and vanishing of the ratios of the pressures with densities of two fluids given by $c_s, d_s$. It is shown that the high-speed approximation scheme breaks down by non-zero pressures $p_1, p_2$ when $c_s, d_s$ are bounded below by some positive constants. The failure of the high-speed approximation scheme at some particular time of the gravitational collapse suggests the uncertainity on the evolution at and after this time. In the bounded case, the naked singularity formation seems to be impossible for the cylindrical two perfect fluids. For the vanishing case, if a linear equation of state is used, the high-speed collapse does not break down by the effects of the pressures and consequently a naked singularity forms. This work provides the generalisation of the results already given by Nakao and Morisawa [1] for the perfect fluid.

M. Sharif; Zahid Ahmad

2007-04-20T23:59:59.000Z

159

MEASUREMENT OF WIND SPEED FROM COOLING LAKE THERMAL IMAGERY  

SciTech Connect (OSTI)

The Savannah River National Laboratory (SRNL) collected thermal imagery and ground truth data at two commercial power plant cooling lakes to investigate the applicability of laboratory empirical correlations between surface heat flux and wind speed, and statistics derived from thermal imagery. SRNL demonstrated in a previous paper [1] that a linear relationship exists between the standard deviation of image temperature and surface heat flux. In this paper, SRNL will show that the skewness of the temperature distribution derived from cooling lake thermal images correlates with instantaneous wind speed measured at the same location. SRNL collected thermal imagery, surface meteorology and water temperatures from helicopters and boats at the Comanche Peak and H. B. Robinson nuclear power plant cooling lakes. SRNL found that decreasing skewness correlated with increasing wind speed, as was the case for the laboratory experiments. Simple linear and orthogonal regression models both explained about 50% of the variance in the skewness - wind speed plots. A nonlinear (logistic) regression model produced a better fit to the data, apparently because the thermal convection and resulting skewness are related to wind speed in a highly nonlinear way in nearly calm and in windy conditions.

Garrett, A; Robert Kurzeja, R; Eliel Villa-Aleman, E; Cary Tuckfield, C; Malcolm Pendergast, M

2009-01-20T23:59:59.000Z

160

Speed of sound in liquids at high pressure  

E-Print Network [OSTI]

In this paper, a new general formula for the sound speed in adiabatic conditions ( S = const ) has been established. The sound speed depends on the mass density {\\rho} (p,T ) and the internal energy per unit mass E(p,T ), both expressed as functions of the pressure p and the temperature T . This formula has been compared with experimental data on the example of triolein over the pressure range up to 450 MPa. For experimental data, phenomenological approximate formulas have been proposed. Those formulas have two versions, depending on the 2 and 3 parameters. Both versions have been developed with the help of the new expression (Eq.8) for the sound speed. The explicit form of both approximate curves can be regarded as the result of purely phenomenological modeling. However, in this paper, these new analytical expressions have been obtained by applying the heuristic procedure described in Appendix.

P., Kielczynski; S, Piekarski

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Constant power speed range extension of surface mounted PM motors  

DOE Patents [OSTI]

A circuit and method for controlling a rotating machine (11) in the constant horsepower range above base speed uses an inverter (15) having SCR's (T1-T6) connected in series with the primary commutation switches (Q1-Q6) to control turn off of the primary commutation switches and to protect the primary commutation switches from faults. The primary commutation switches (Q1-Q6) are controlled by a controller (14), to fire in advance or after a time when the back emf equals the applied voltage, and then to turn off after a precise dwell time, such that suitable power is developed at speeds up to at least six times base speed.

Lawler, Jack Steward (Knoxville, TN); Bailey, John Milton (Knoxville, TN)

2001-01-01T23:59:59.000Z

162

Systematic Controller Design Methodology for Variable-Speed Wind Turbines  

SciTech Connect (OSTI)

Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three operational regions. This paper provides a guide for controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship between the two opposing metrics is easily visualized.

Hand, M. M.; Balas, M. J.

2002-02-01T23:59:59.000Z

163

Ultra-high-speed optical and electronic distributed devices  

SciTech Connect (OSTI)

This report summarizes work on the development of ultra-high-speed semiconductor optical and electronic devices. High-speed operation is achieved by velocity matching the input stimulus to the output signal along the device`s length. Electronic devices such as field-effect transistors (FET`s), should experience significant speed increases by velocity matching the electrical input and output signals along the device. Likewise, optical devices, which are typically large, can obtain significant bandwidths by velocity matching the light being generated, detected or modulated with the electrical signal on the device`s electrodes. The devices discussed in this report utilize truly distributed electrical design based on slow-wave propagation to achieve velocity matching.

Hietala, V.M.; Plut, T.A.; Kravitz, S.H.; Vawter, G.A.; Wendt, J.R.; Armendariz, M.G.

1995-08-01T23:59:59.000Z

164

Local non-Gaussianity from rapidly varying sound speeds  

SciTech Connect (OSTI)

We study the effect of non-trivial sound speeds on local-type non-Gaussianity during multiple-field inflation. To this end, we consider a multiple-DBI model and use the ?N formalism to track the super-horizon evolution of perturbations. By adopting a sum separable Hubble parameter we derive analytic expressions for the relevant quantities in the two-field case, valid beyond slow variation. We find that non-trivial sound speeds can, in principle, curve the trajectory in such a way that significant local-type non-Gaussianity is produced. Deviations from slow variation, such as rapidly varying sound speeds, enhance this effect. To illustrate our results we consider two-field inflation in the tip regions of two warped throats and find large local-type non-Gaussianity produced towards the end of the inflationary process.

Emery, Jon; Tasinato, Gianmassimo; Wands, David, E-mail: jon.emery@port.ac.uk, E-mail: gianmassimo.tasinato@port.ac.uk, E-mail: david.wands@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom)

2012-08-01T23:59:59.000Z

165

Speed-up of combustion fronts in shear flows  

E-Print Network [OSTI]

This paper is concerned with the analysis of speed-up of reaction-diffusion-advection traveling fronts in infinite cylinders with periodic boundary conditions. The advection is a shear flow with a large amplitude and the reaction is nonnegative, with either positive or zero ignition temperature. The unique or minimal speeds of the traveling fronts are proved to be asymptotically linear in the flow amplitude as the latter goes to infinity, solving an open problem from \\cite{b}. The asymptotic growth rate is characterized explicitly as the unique or minimal speed of traveling fronts for a limiting degenerate problem, and the convergence of the regular traveling fronts to the degenerate ones is proved for positive ignition temperatures under an additional H{\\"{o}}rmander-type condition on the flow.

Hamel, Francois

2011-01-01T23:59:59.000Z

166

Harmonic mean, the Gamma factor and Speed of Light  

E-Print Network [OSTI]

The relationship between the harmonic mean and special relativity is concisely elucidated. The arguments in favor and against SRT are explored. It is shown that the ratio of the speed of light to the harmonic mean of the onward and return speeds of light in a moving frame under Newtonian mechanics, when equitably distributed between space and time as a correction, leads to the Lorentz transformation. This correction implies an apparent contraction of objects and time dilation. However, the symmetry of the onward and inverse transformations give a different meaning to the gamma factor

Chandru Iyer

2008-11-17T23:59:59.000Z

167

Comparison of operating speeds at spiral transition and circular curves  

E-Print Network [OSTI]

acceleration, fijs; and V = speed, mph In evaluating the models, it was found that the spiral length increases with increasing speed, but does not become unreasonably long. It was also found that the spiral length and spiral ang e epen o y on 1 d d nl... curves provide deceptive information to drivers is based on crash data for spiral curves, he does not present data for comparable circular curves In addition, the issue of whether the spiral curve is causing the crashes or whether crash rates...

Passetti, Karl Andrew

1998-01-01T23:59:59.000Z

168

Development Impacts of high-speed rail : megalopolis formation and implications for Portugal's Lisbon-Porto High-Speed Rail Link  

E-Print Network [OSTI]

High-speed rail (HSR) has been gaining acceptance worldwide with development of rail technology and rising concerns over climate change and congestion in airports and on roads. The implementation of high-speed rail lines ...

Melibaeva, Sevara (Sevara Mukhtarovna)

2010-01-01T23:59:59.000Z

169

EFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE GENERATORS  

E-Print Network [OSTI]

EFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE), Curtin University of Technology, WA Abstract: Variable speed wind turbine generators provide the opportunity to capture more power than fixed speed turbines. However the variable speed machine output can

170

A speed prediction model for a U.S. operating speed-based design consistency procedure on two-lane rural highways  

E-Print Network [OSTI]

was selected (MSE=l0. 43, R'=0. 802). No significant difference was found between the estimated values gencratcd by fourth-order polynomial model and the simple linear model (or=0. 05). Other factors such as the posted speed limit and operational... the design speed concept exclusively. ~g speed- based geometric design attempts to do what the design speed concept originally intended: Transportation Resemh Record 1195, National Research Council, Washington, D. C. , 1988, is used as a model...

Ottesen, Jeffery Lynn

1993-01-01T23:59:59.000Z

171

Energy Implications of Retrofitting Retail Sector Rooftop Units with Stepped-Speed and Variable-Speed Functionality  

SciTech Connect (OSTI)

Commercial retailers understand that retrofitting constant-speed RTU fan motors with stepped- or variable-speed alternatives could save significant energy in most U.S. climate zones. However, they lack supporting data, both real-world and simulation based, on the cost effectiveness and climate zone-specific energy savings associated with this measure. Thus, building managers and engineers have been unable to present a compelling business case for fan motor upgrades to upper management. This study uses whole-building energy simulation to estimate the energy impact of this type of measure so retailers can determine its economic feasibility.

Studer, D.; Romero, R.; Herrmann, L.; Benne, K.

2012-04-01T23:59:59.000Z

172

Convergence Speed of GARCH Option Price to Diffusion Option Price  

E-Print Network [OSTI]

Convergence Speed of GARCH Option Price to Diffusion Option Price Jin-Chuan Duan, Yazhen Wang that as the time interval between two consecutive observations shrinks to zero, a properly constructed GARCH model will weakly converge to a bivariate diffusion. Naturally the European option price under the GARCH model

Chaudhuri, Sanjay

173

Convergence Speed of GARCH Option Price to Diffusion Option Price  

E-Print Network [OSTI]

Convergence Speed of GARCH Option Price to Diffusion Option Price Jin-Chuan Duan National constructed GARCH model will weakly converge to a bi- variate diffusion. Naturally the European option price under the GARCH model will also converge to its bivariate diffusion counterpart. This paper investigates

Wang, Yazhen

174

Speed and Energy Performance Asynchronous MIPS R3000 Microprocessor  

E-Print Network [OSTI]

is at least four times as fast as a commercial MIPS R3000 in the same technology at its initial introductionSpeed and Energy Performance of an Asynchronous MIPS R3000 Microprocessor Alain J. Martin Mika Nystrom Paul Penzes Catherine Wong California Institute of Technology Pasadena, CA 91125 June 22, 2001

175

Improving the Accuracy and Speed of Support Vector Machines  

E-Print Network [OSTI]

Improving the Accuracy and Speed of Support Vector Machines Chris J.C. Burges Bell Laboratories bs@mpik-tueb.mpg.de Abstract Support Vector Learning Machines (SVM) are nding application in pattern to achieve a factor of fty speedup in test phase over the virtual support vector machine. The combined

176

High Speed Rail in Greece : methods for evaluating economic impacts  

E-Print Network [OSTI]

High Speed Rail is a mode that gains popularity every day. Many countries have such a network and others are on the way to adopting one. Greece, which is part of the European Union, is one of those countries that are looking ...

Radopoulou, Stefania Christina

2010-01-01T23:59:59.000Z

177

Modeling of a rotor speed transient response with radial rubbing  

E-Print Network [OSTI]

by an accidental blade­off imbalance. In order to assess the angular deceleration of the rotor due to rubbingModeling of a rotor speed transient response with radial rubbing Sébastien Roques1 Institut deGill Univer- sity, 817 Sherbrooke St West, Montreal, Quebec H3A 2K6, Canada Abstract A rotor­stator model

Boyer, Edmond

178

Effect of shrink fits on threshold speeds of rotordynamic instability  

E-Print Network [OSTI]

The purpose of this thesis is to study the effect of shrink fits on the threshold speeds of rotor instability. Shrink or press fit components in built-up rotors are known sources of internal friction damping. The internal friction damping increases...

Al-Baz, Khalid A

2001-01-01T23:59:59.000Z

179

Possible Origin Of The Neutrino Speed Anomaly Reported By OPERA  

E-Print Network [OSTI]

Recently the OPERA collaboration reported a measurement of a superluminal speed of muon neutrinos travelling through the Earth's crust between their production site at CERN and their detection site under Gran Sasso, ~730 km away. The measurement was based on the assumption that the pulse shape of the neutrinos from the decay of parent mesons produced in proton-target collisions is the same as that of the incident protons. Here we argue that the effective column density of the target along the beam direction decreases with time during the 10.5 microseconds duration of the proton pulse. This is because of the thermal expansion and expulsion of target material along the beam by the energy-momentum deposition during the 10.5 microseconds pulse. The progresive reduction in the effective column density during the pulse decreases the neutrino production rate per incident proton. It could have advanced the mean production time of the detected neutrinos relative to that calculated from the proton pulse-shape, by an amount comparable to the measured neutrino lead time (60.7+/-6.9(stat) +/-7.4(sys) ns. This explanation implies that the planned measurements by OPERA of the speed of neutrinos produced in much shorter (a few ns) pulses, should yield a speed consistent with the speed of light in free space.

Shlomo Dado; Arnon Dar

2011-10-28T23:59:59.000Z

180

High density Integrated Optoelectronic Circuits for High Speed Photonic Microsystems  

E-Print Network [OSTI]

High density Integrated Optoelectronic Circuits for High Speed Photonic Microsystems K. Minoglou.minoglou@imel.demorkitos.gr Abstract. The study of high density integrated optoelectronic circuits involves the development of hybrid integration technologies and the generation of models for the optoelectronic devices. To meet these goals

Kouroupetroglou, Georgios

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

LM119/LM219/LM319 High Speed Dual Comparator  

E-Print Network [OSTI]

LM119/LM219/LM319 High Speed Dual Comparator General Description The LM119 series are precision higher gain and lower input currents than devices like the LM710. The uncommitted collector of the output stage makes the LM119 compatible with RTL, DTL and TTL as well as capable of driving lamps and relays

Lanterman, Aaron

182

On measurement of the isotropy of the speed of light  

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

Three experimental concepts investigating possible anisotropy of the speed of light are presented. They are based on i) beam deflection in a 180 degree magnetic arc, ii) narrow resonance production in an electron-positron collider, and iii) the ratio of magnetic moments of an electron and a positron moving in opposite directions.

Wojtsekhowski, Bogdan B. [JLAB

2014-11-01T23:59:59.000Z

183

Response of a vessel to waves at zero ship speed  

E-Print Network [OSTI]

Response of a vessel to waves at zero ship speed: preliminary full scale experiments By: Kim Klaka of experiment were conducted free roll decay tests and irregular wave tests. An inclining test was also with and without the mainsail hoisted, in very light winds. The irregular wave tests were conducted again in very

184

Ultrafast Digital Electronics: Optimizing the speed of a  

E-Print Network [OSTI]

Ultrafast Digital Electronics: Optimizing the speed of a Josephson junction J. K. Freericks and P, Georgetown University, Josephson Junction talk, 2000 #12;Josephson Tunnel Junctions · A Superconductor to "punch-through"). J. K. Freericks, Georgetown University, Josephson Junction talk, 2000 S I S I I V V Ic

Freericks, Jim

185

Sensor-bedazzled balloon catheter speeds up heart surgery  

E-Print Network [OSTI]

Sensor-bedazzled balloon catheter speeds up heart surgery By Janet Fang | Mar 7, 2011 | 0 Comments A little while ago, cardiologists improved open-heart surgery by using super thin, flexible balloon, says Rogers. Currently, heart surgeons map tissue using pointed catheters with electrodes, which

Rogers, John A.

186

Speed-dependent Automatic Zooming for Browsing Large Documents  

E-Print Network [OSTI]

@microsoft.com ABSTRACT We propose a navigation technique for browsing large documents that integrates rate. With typical scrolling interfaces, it is difficult to browse a large document efficiently. UsingSpeed-dependent Automatic Zooming for Browsing Large Documents Takeo Igarashi Computer Science

Igarashi, Takeo

187

Imaging of high-speed dust particle trajectories on NSTX  

SciTech Connect (OSTI)

Imaging of high-speed incandescent dust particle trajectories in a tokamak plasma has been accomplished on NSTX using up to three high-speed cameras each viewing the same plasma volume from different locations and operating at speeds up to 68 000 frames/s with exposure times varying from 2 to 300 {mu}s. The dynamics of the dust trajectories can be quite complex exhibiting a large variation in both speed (10-200 m/s) and direction. Simulations of these trajectories will be utilized to ascertain the role dust may play in future machines such as ITER where significant dust production from wall erosion is expected. NSTX has numerous view ports including both tangential as well as radial views in both the midplane and lower divertors. Several vertical ports are also available so that a few specific regions in NSTX may be viewed simultaneously from several different camera positions. The cameras can be operated in the full visible spectrum but near-infrared filters can be utilized to enhance the observation of incandescent particles against a bright background. A description of the cameras and required optics is presented.

Roquemore, A. L.; Davis, W.; Kaita, R.; Skinner, C. H.; Maqueda, R.; Nishino, N. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Nova Photonics, Inc., Princeton, New Jersey 08540 (United States); Hiroshima University, Hiroshima 739-8527 (Japan)

2006-10-15T23:59:59.000Z

188

ADAPTIVE IIR FILTERING: CONVERGENCE SPEED PROPERTIES IN THE UNDERMODELLED CASE  

E-Print Network [OSTI]

high order, possi- bly infinite (meaning its transfer function is not ratio- nal). It is also true for sufficient order can be applied with any confidence. In other words, does the existence of a good and concerning the local convergence speed of adap- tive IIR filters apply to the sufficient order case

Regalia, Phillip A.

189

3D Laser Imaging at Highway Speed Kelvin CP Wang  

E-Print Network [OSTI]

3D Laser Imaging at Highway Speed Kelvin CP Wang And the Team Formerly at the University Concrete Consortium Meeting Oklahoma City Sheraton Hotel #12;3D Laser Imaging for Pavements Mature Potential to Cover Most if Not All Data Collection on Pavement Surface How to Obtain True 1mm 3D Visual

190

The Engineering Management of Speed Robert C. Leachman  

E-Print Network [OSTI]

of imputing an overall economic value to engineering projects that impact lead time. Practical analytical evaluations of engineers and managers rarely measure the total economic impact of improvements made1 The Engineering Management of Speed Robert C. Leachman Dept. of Industrial Engineering

Kammen, Daniel M.

191

Ultrafast Digital Electronics: Optimizing the speed of a  

E-Print Network [OSTI]

Ultrafast Digital Electronics: Optimizing the speed of a Josephson junction J. K. Freericks and P of Naval Research Preprint: cond-mat/0001269 J. K. Freericks, Georgetown University, Josephson Junction symmetry (examples include YBCO and BSCCO). J. K. Freericks, Georgetown University, Josephson Junction talk

Freericks, Jim

192

Best Practices for Energy Efficient Cleanrooms: Variable Speed Pumping  

E-Print Network [OSTI]

efficiency of chilled water and condenser pumps, along with chiller efficiency and cooling tower efficiency, operate, and control water-pumping systems to achieve high efficiency and to lower life-cycle costsLBNL-58637 Best Practices for Energy Efficient Cleanrooms: Variable Speed Pumping Tengfang Xu June

193

High-speed gears for gas turbine drive  

SciTech Connect (OSTI)

Recently, Lufkin Industries, Power Transmission Div., full-load tested a high-speed gear designed to couple a 50 Hz electric power generator to a GE LM6000 gas turbine for a power generation project in Australia. The gear is rated 52.2 MW to match the output of the LM6000 gas turbine believed to be one of the largest gear testing operations for this type and size of gear. Each gear drive manufactured by Lufkin is full-speed tested to verify its performance. Tests performed on high-speed units duplicate field conditions, as closely as possible, in order to verify critical speed analysis results and new bearing designs, if used. Lufkin also tests design techniques used in the development of new products. The finite element analysis performed to predict housing deflection in the thrust bearing area of a new extruder driveline was verified by testing of a prototype unit housing. Recently, housing structure stiffness and natural frequencies were predicted and verified on the test stand for some 50 MW vertically offset gear units. A complete data acquisition system is used to gather data from bearing, inlet and drain temperature monitoring points. The temperature monitoring system will accommodate type T,K,J, and E thermocouples and platinum and nickel RTDs.

Kane, J.

1995-06-01T23:59:59.000Z

194

High-speed pulse-shape generator, pulse multiplexer  

DOE Patents [OSTI]

The invention combines arbitrary amplitude high-speed pulses for precision pulse shaping for the National Ignition Facility (NIF). The circuitry combines arbitrary height pulses which are generated by replicating scaled versions of a trigger pulse and summing them delayed in time on a pulse line. The combined electrical pulses are connected to an electro-optic modulator which modulates a laser beam. The circuit can also be adapted to combine multiple channels of high speed data into a single train of electrical pulses which generates the optical pulses for very high speed optical communication. The invention has application in laser pulse shaping for inertial confinement fusion, in optical data links for computers, telecommunications, and in laser pulse shaping for atomic excitation studies. The invention can be used to effect at least a 10.times. increase in all fiber communication lines. It allows a greatly increased data transfer rate between high-performance computers. The invention is inexpensive enough to bring high-speed video and data services to homes through a super modem.

Burkhart, Scott C. (Livermore, CA)

2002-01-01T23:59:59.000Z

195

High-Speed Parameter Estimation Algorithms For Nonlinear Smart Materials  

E-Print Network [OSTI]

High-Speed Parameter Estimation Algorithms For Nonlinear Smart Materials Jon M. Ernstberger with experimental data. 1. INTRODUCTION Smart materials exhibit unique actuator and sensor capabilities for a range of aerospace, aeronautic, indus- trial and DoD applications. Applications of smart materials include

196

SUPER HIGH-SPEED MINIATURIZED PERMANENT MAGNET SYNCHRONOUS MOTOR  

E-Print Network [OSTI]

with the design of permanent magnet synchronous motors (PMSM) to operate at super-high speed with high efficiency. The designed and fabricated PMSM was successfully tested to run upto 210,000 rpm The designed PMSM has 2000 W concept of electrical machines. After that, the modeling of PMSM for dynamic simulation is provided

Wu, Thomas

197

Performance of twist-coupled blades on variable speed rotors  

SciTech Connect (OSTI)

The load mitigation and energy capture characteristics of twist-coupled HAWT blades that are mounted on a variable speed rotor are investigated in this paper. These blades are designed to twist toward feather as they bend with pretwist set to achieve a desirable twist distribution at rated power. For this investigation, the ADAMS-WT software has been modified to include blade models with bending-twist coupling. Using twist-coupled and uncoupled models, the ADAMS software is exercised for steady wind environments to generate C{sub p} curves at a number of operating speeds to compare the efficiencies of the two models. The ADAMS software is also used to generate the response of a twist-coupled variable speed rotor to a spectrum of stochastic wind time series. This spectrum contains time series with two mean wind speeds at two turbulence levels. Power control is achieved by imposing a reactive torque on the low speed shaft proportional to the RPM squared with the coefficient specified so that the rotor operates at peak efficiency in the linear aerodynamic range, and by limiting the maximum RPM to take advantage of the stall controlled nature of the rotor. Fatigue calculations are done for the generated load histories using a range of material exponents that represent materials from welded steel to aluminum to composites, and results are compared with the damage computed for the rotor without twist-coupling. Results indicate that significant reductions in damage are achieved across the spectrum of applied wind loading without any degradation in power production.

Lobitz, D.W.; Veers, P.S.; Laino, D.J.

1999-12-07T23:59:59.000Z

198

Adjustable speed drives: Applications and R&D needs  

SciTech Connect (OSTI)

The largest opportunity for the growth of adjustable speed drives (ASDs) during the next 5-6 years is in pump, fan and compressor (PFC) applications where a constant, fixed speed operation is converted to adjustable speed in order to realize energy savings. Inverter supplied induction motors are and will continue to be predominately used in these applications. Over the long term (10-15 years), the greatest ASD growth is expected in large volume consumer applications: first in hybrid electric vehicles (EVs) and in residential heating, ventilation and air-conditioning (HVAC). Both induction and a variety of AC Permanent Magnet motors are expected to be the dominant technology in this new field. The traditional ASD applications in industries which require adjustable speed (such as machine tools, robotics, steel rolling, extruders, paper mill finishing lines, etc.) offer a relatively limited potential for above average ASD growth since most of these applications have already converted to electronic speed control. As a result, ASD growth in this sector will essentially track the growth of the corresponding industries. If realized, both short and long term ASD growth opportunities will result in significant advancements of ASD technology, which will then substantially affect all other, more fragmented, ASD applications. In fact, any single large volume ASD application will serve as a catalyst for improving ASD characteristics in all other ASD applications with the same voltage rating. ASD cost and reliability (defined in the context of application compatibility) are the two most important factors which will determine whether the ASD growth opportunities are realized. Conversely, any technological improvement which carries a cost increase will be restricted to niche applications, at best. Consequently, future R & D efforts should be directed to secure reduction in ASD cost and improvement in ASD reliability. A specific action plan is outlined in this report.

Stefanovic, V.R.

1995-09-01T23:59:59.000Z

199

Controlled Speed Accessory Drive Program: Programmatic environmental assessment  

SciTech Connect (OSTI)

This document is a programmatic environmental assessment of the Department of Energy's Controlled Speed Accessory Drive (CSAD) program and alternatives. Its purpose is to evaluate CSAD alternatives to assure that environmental priorities are considered at the earliest meaningful point in the decision-making process, and to facilitate the choice of preferable options. This document accords with both the letter and the spirit of the National Environmental Policy Act (NEPA) requirements as interpreted and standardized by the Council on Environmental Quality. The major conclusions reached in this assessment are as follows: (1) controlled speed accessory drive bolted onto existing automobile designs may not provide adequate engine cooling when operated at high ambient temperatures or under heavy loading; (2) when the CSAD is adopted for production, the emissions effect of controlled speed accessory drive will not be a problem. Auto emissions are already controlled by existing regulations, and automobiles with a CSAD must meet the same emission standards as non-CSAD vehicles; (3) the nature of the impact is such that significant expansion of the market will not affect it. The one adverse environmental concern, the engine cooling problem, will probably be remedied by proper optimization of automobiles for controlled speed accessory drive, or, until the problem can be alleviated, it will delay commercialization of the drive. No safety hazard will be introduced to the American roadways. In addition, no adverse environmental concerns directly related to the Controlled Speed Accessory Drive demonstration program are anticipated. Therefore, it is recommended that a finding of no significant impact be prepared.

Not Available

1980-04-14T23:59:59.000Z

200

Laser synchronized high-speed shutter for spectroscopic application  

DOE Patents [OSTI]

A fast mechanical shutter, based on rotating chopper wheels, has been designed and implemented to shutter the entrance slit of a spectrograph. This device enables an exposure time of 9 .mu.s to be achieved for a 0.8 mm wide spectrograph entrance slit, achieves 100% transmission in the open state, and an essentially infinite extinction ratio. The device further incorporates chopper wheel position sensing electronics to permit the synchronous triggering of a laser source.

Miles, Paul C. (Tracy, CA); Porter, Eldon L. (Tracy, CA); Prast, Thomas L. (Livermore, CA); Sunnarborg, Duane A. (Livermore, CA)

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Wind energy conversion system  

DOE Patents [OSTI]

The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

Longrigg, Paul (Golden, CO)

1987-01-01T23:59:59.000Z

202

High Speed Reconfigurable FFT Design by Vedic Mathematics  

E-Print Network [OSTI]

The Fast Fourier Transform (FFT) is a computationally intensive digital signal processing (DSP) function widely used in applications such as imaging, software-defined radio, wireless communication, instrumentation. In this paper, a reconfigurable FFT design using Vedic multiplier with high speed and small area is presented. Urdhava Triyakbhyam algorithm of ancient Indian Vedic Mathematics is utilized to improve its efficiency. In the proposed architecture, the 4x4 bit multiplication operation is fragmented reconfigurable FFT modules. The 4x4 multiplication modules are implemented using small 2x2bit multipliers. Reconfigurability at run time is provided for attaining power saving. The reconfigurable FFT has been designed, optimized and implemented on an FPGA based system. This reconfigurable FFT is having the high speed and small area as compared to the conventional FFT.

Raman, Ashish; Sarin, R K

2010-01-01T23:59:59.000Z

203

Fabrication of High-Speed Resonant Cavity Enhanced Schottky Photodiodes  

E-Print Network [OSTI]

Abstract We report the fabrication and testing of a GaAsbased high-speed resonant cavity enhanced (RCE) Schottky photodiode. The top-illuminated RCE detector is constructed by integrating a Schottky contact, a thin absorption region (InHXHVGaHXWPAs) and a distributed AlAsGaAs Bragg mirror. The Schottky contact metal serves as a high-reflectivity top mirror in the RCE detector structure. The devices were fabricated by using a microwave-compatible fabrication process. The resulting spectral photo response had a resonance around 895 nm, in good agreement with our simulations. The full-widthat-half-maximum (FWHM) was 15 nm, and the enhancement factor was in excess of 6. The photodiode had an experimental setup limited temporal response of 18 ps FWHM, corresponding to a 3-dB bandwidth of 20 GHz. Index TermsHigh-speed circuits/devices, photodetectors, photodiodes, resonant caity enhancement, Schottky diodes.

Ekmel zbay; M. Saiful Islam; Bora Onat; Student Member; Mutlu Gkkavas; Orhan Aytr; Gary Tuttle; Elias Towe; R. H. Henderson; M. Selim nl; Senior Member

204

High-speed, sub-pull-in voltage MEMS switching.  

SciTech Connect (OSTI)

We have proposed and demonstrated MEMS switching devices that take advantage of the dynamic behavior of the MEMS devices to provide lower voltage actuation and higher switching speeds. We have explored the theory behind these switching techniques and have demonstrated these techniques in a range of devices including MEMS micromirror devices and in-plane parallel plate MEMS switches. In both devices we have demonstrated switching speeds under one microsecond which has essentially been a firm limit in MEMS switching. We also developed low-loss silicon waveguide technology and the ability to incorporate high-permittivity dielectric materials with MEMS. The successful development of these technologies have generated a number of new projects and have increased both the MEMS switching and optics capabilities of Sandia National Laboratories.

Spahn, Olga Blum; Brewer, Steven; Olsson, Roy H.; Bogart, Gregory R.; Luck, David L.; Watts, Michael R.; Shaw, Michael J.; Nielson, Gregory N.; Resnick, Paul James; Tigges, Christopher P.; Grossetete, Grant David

2008-01-01T23:59:59.000Z

205

Development of a high speed crowbar for LANSCE  

SciTech Connect (OSTI)

Each of the four 200 MHz Final Power Amplifiers (FPAs) in the LANSCE proton linac has its own capacitor bank and crowbar. The dissipation in the 10{Omega} crowbar limiting resistor is as high as 67 kW, and oil cooling is used. The authors stated upgrade goal was to substantially reduce the limiting resistor dissipation and eliminate the oil cooling. Early tests showed that the fault energy quickly rose to unacceptable levels as the current limiting resistance was reduced. FPA arcs are normally quenched by interrupting the FPA modulator current, and the crowbar waits 10 {mu}s for this to occur. The successful upgrade strategy was to replace the 10{Omega} resistor with a 3{Omega} air cooled resistor and to add a high speed crowbar circuit which operates only if there are simultaneous arcs in the FPA and its modulator. This paper describes the high speed circuit and its interface with the existing crowbar. Test results are also given.

Friedrichs, C. Jr.; Lyles, J.T.M.; Doub, J.M.

1997-08-01T23:59:59.000Z

206

Correction due to finite speed of light in absolute gravimeters  

E-Print Network [OSTI]

Correction due to finite speed of light is among the most inconsistent ones in absolute gravimetry. Formulas reported by different authors yield corrections scattered up to 8 $\\mu$Gal with no obvious reasons. The problem, though noted before, has never been studied, and nowadays the correction is rather postulated than rigorously proven. In this paper we investigate the problem from several prospectives, find the corrections for different types of absolute gravimeters, and establish relationships between different ways of implement them. The obtained results enabled us to analyze and understand the discrepancies in the results of other authors. We found that the correction derived from the Doppler effect is accountable only for $\\tfrac{2}{3}$ of the total correction due to finite speed of light, if no signal delays are considered. Another major source of inconsistency was found in the tacit use of simplified trajectory models.

Nagornyi, V D; Zanimonskiy, Y Y

2010-01-01T23:59:59.000Z

207

Probabilistic assessment of tornado-borne missile speeds. Final report  

SciTech Connect (OSTI)

A procedure was developed for estimating speeds with which postulated missiles hit any given set of targets in a nuclear power plant or similar installation. Hit speeds corresponding to probabilities of occurrence of .0000001 were calculated for a given nuclear power plant under various assumptions concerning the magnitude of the force opposing missile take-off, direction of tornado axis of translation, number and location of missiles, and size of target area. The results of the calculations are shown to depend upon the parameters: CDA/m, where CD = drag coefficient, A = projected area, m = mass of missiles, and the ratio, k, between the minimum aerodynamic force required to cause missile take-off, and the weight of the missile.

Simiu, E.; Cordes, M.R.

1980-09-01T23:59:59.000Z

208

Speed Meter As a Quantum Nondemolition Measuring Device for Force  

E-Print Network [OSTI]

Quantum noise is an important issue for advanced LIGO. Although it is in principle possible to beat the Standard Quantum Limit (SQL), no practical recipe has been found yet. This paper dicusses quantum noise in the context of speedmeter-a devise monitoring the speed of the testmass. The scheme proposed to overcome SQL in this case might be more practical than the methods based on monitoring position of the testmass.

F. Ya. Khalili; Yu. Levin

1996-03-26T23:59:59.000Z

209

Laboratory implementation of variable-speed wind turbine generation  

SciTech Connect (OSTI)

To improve the performance of wind turbines, various control schemes such as variable speed operation have been proposed. Testing of these control algorithms on a full scale system is very expensive. To test these systems simulation, we developed programs and small scale laboratory experiments. We used this system to verify a control method that attempts to keep the turbine operating at its peak power coefficient. Both the simulations and the experiments verified the principle of operation of this control scheme.

Zinger, D.S. [Northern Illinois University, DeKalb, IL (United States)] [Northern Illinois University, DeKalb, IL (United States); Miller, A.A. [Univ. of Idaho, Moscow, ID (United States)] [Univ. of Idaho, Moscow, ID (United States); Muljadi, E.; Butterfield, C.P.; Robinson, M.C. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States)

1996-07-01T23:59:59.000Z

210

Low speed engine for supersonic and hypersonic vehicles  

SciTech Connect (OSTI)

This patent describes a jet engine suitable for use in an aircraft in a range of speeds from zero to hypersonic flight. It comprises: a duct having a relatively small diameter mixing zone and a relatively large diameter combustion zone located down stream from the mixing zone; a secondary injector positioned between the primary injector and the combustion zone, supply means for supplying a fuel rich injectant to the primary injector so that the primary injector forces the injectant into the duct.

Klees, G.W.; Sloan, M.L.; Thornock, R.L.

1992-07-14T23:59:59.000Z

211

Gearbox Reliability Collaborative High-Speed Shaft Calibration  

SciTech Connect (OSTI)

Instrumentation has been added to the high-speed shaft, pinion, and tapered roller bearing pair of the Gearbox Reliability Collaborative gearbox to measure loads and temperatures. The new shaft bending moment and torque instrumentation was calibrated and the purpose of this document is to describe this calibration process and results, such that the raw shaft bending and torque signals can be converted to the proper engineering units and coordinate system reference for comparison to design loads and simulation model predictions.

Keller, J.; McNiff, B.

2014-09-01T23:59:59.000Z

212

VHISPER: a high speed dual mode VLIW and Superscalar Processor  

E-Print Network [OSTI]

, increases the clock speed and lowers the CPI. The processors representative of the RISC design are the Sun SPARC, Intel i860, Motorola M88100, and AMD 29000. All of these processors use 32-bit instructions. The instruction sets of these machines consist... of 51 to 124 basic instructions. Each of these processors issue one instruction per cycle. The Sun SPARC design is derived from the original Berkeley RISC design. SPARC stands for scalable processor archi- tecture. The scalability of the SPARC refers...

Mellacheruvu, Rajesh Kumar

1994-01-01T23:59:59.000Z

213

Extended cage adjustable speed electric motors and drive packages  

DOE Patents [OSTI]

The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced. 12 figs.

Hsu, J.S.

1999-03-23T23:59:59.000Z

214

Adjustable Speed AC Motor Drives-Applications Problems  

E-Print Network [OSTI]

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

Enjeti, P.

215

Extended cage adjustable speed electric motors and drive packages  

DOE Patents [OSTI]

The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced.

Hsu, John S. (Oak Ridge, TN)

1999-01-01T23:59:59.000Z

216

Adjustable Speed Drives as Applied to Centrifugal Pumps  

E-Print Network [OSTI]

Required Power In addition to energy savings, which are discussed in detail later, operation at reduced pressures can result in longer pump seal life, reduced impeller wear, and less system vibration and noise. These benefits could provide additional... FLOW CONTROL TECHNIQUES Historically, centrifugal pumps have been driven by fixed speed A-C motors and reduced flow has been achieved by using control valves as shown in Figure 8. Closing the valve reduces the flow by increasing the friction...

Jarc, D. A.; Robechek, J. D.; Connors, D. P.

1982-01-01T23:59:59.000Z

217

LIDAR Wind Speed Measurements of Evolving Wind Fields  

SciTech Connect (OSTI)

Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feedforward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. Past studies have assumed Taylor's frozen turbulence hypothesis, which implies that turbulence remains unchanged as it advects downwind at the mean wind speed. With Taylor's hypothesis applied, the only source of wind speed measurement error is distortion caused by the LIDAR. This study introduces wind evolution, characterized by the longitudinal coherence of the wind, to LIDAR measurement simulations to create a more realistic measurement model. A simple model of wind evolution is applied to a frozen wind field used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements are also evaluated with a large eddy simulation of a stable boundary layer provided by the National Center for Atmospheric Research. Simulation results show the combined effects of LIDAR errors and wind evolution for realistic turbine-mounted LIDAR measurement scenarios.

Simley, E.; Pao, L. Y.

2012-07-01T23:59:59.000Z

218

Low pressure high speed Stirling air engine. Final technical report  

SciTech Connect (OSTI)

The purpose of this project was to design, construct and test a simple, appropriate technology low pressure, high speed, wood-fired Stirling air engine of 100 W output. The final design was a concentric piston/displacer engine of 454 in. bore and 1 in. stroke with a rhombic drive mechanism. The project engine was ultimately completed and tested, using a propane burner for all tests as a matter of convenience. The 100 W aim was exceeded, at atmospheric pressure, over a wide range of engine speed with the maximum power being 112 W at 1150 rpm. A pressure can was constructed to permit pressurization; however the grant funds were running out, and the only pressurized power test attempted was unsuccessful due to seal difficulties. This was a disappointment because numerous tests on the 4 cubic inch engine suggested power would be more than doubled with pressurization at 25 psig. A manifold was designed and constructed to permit operation of the engine over a standard No. 40 pot bellied stove. The engine was run successfully, but at reduced speed and power, over this stove. The project engine started out being rather noisy in operation, but modifications ultimately resulted in a very quiet engine. Various other difficulties and their solutions also are discussed. (LCL)

Ross, M.A.

1980-06-16T23:59:59.000Z

219

Validation of and enhancements to an operating-speed-based geometric design consistency evaluation model  

E-Print Network [OSTI]

This thesis documents efforts to validate two elements related to an operating-speed-based geometric design consistency evaluation procedure: (1) the speed reduction estimation ability of the model, and (2) assumptions about acceleration...

Collins, Kent Michael

1995-01-01T23:59:59.000Z

220

E-Print Network 3.0 - advanced ultra-high speed Sample Search...  

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

** This paper describes an ultra high-speed... to be considerably small to prevent huge centrifugal force caused by the ultra high-speed rotation. The stator... system. Keywords:...

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Design, fabrication and mechanical optimization of a flexural high speed nanopositioning imaging stage  

E-Print Network [OSTI]

The intent of this research is to generate the knowledge required to design, fabricate and operate a device capable of high speed nano-scale vertical positioning of microscopy samples. The high speed focusing device (HSFD) ...

Panas, Robert M. (Robert Matthew)

2009-01-01T23:59:59.000Z

222

High-speed rail commuting in the United States : a case study in California  

E-Print Network [OSTI]

High-speed rail (HSR) is primarily for intermediate distance intercity passenger travel. The concept of high-speed rail commuting is to provide short distance commuting transportation service on dedicated HSR, by sharing ...

Kasuya, Shuichi, 1972-

2005-01-01T23:59:59.000Z

223

United States- Land Based and Offshore Annual Average Wind Speed at 100 Meters  

Broader source: Energy.gov [DOE]

Full-size, high resolution version of the 100-meter land-based and offshore wind speed resource map.

224

Guidelines for installing two-way left-turn lanes on high-speed suburban roadways  

E-Print Network [OSTI]

benefits (reduced accident potential) for a high-speed suburban roadway with no existing median. From the results of this study, it was recommended that TWLTL facilities be provided on high-speed suburban roadways with average daily traffic volumes... vehicles, even at low speeds and low angles of approach. In fact, the curbs may increase the potential for severe accidents by causing vaulting. In this situation, higher operating speeds will only enhance the problem. One possible solution for suburban...

Nowlin, Ronald Lewis

1994-01-01T23:59:59.000Z

225

Adjustable Speed Pumping Applications: Industrial Technologies Program (ITP) Pumping Systems Tip Sheet #11  

SciTech Connect (OSTI)

This two-page tip sheet provides practical tips on application of Adjustable Speed Drives in industrial settings.

Not Available

2007-01-01T23:59:59.000Z

226

Relationship between speed distribution measures and rural two-lane highway characteristics  

E-Print Network [OSTI]

mandated 55 mph (88. 5 km/h) speed limit, the original design speed of a roadway does not always meet the desired operating speeds of today's drivers. Thus, a design consistency approach has been suggested as an alternative means for ensuring driver... STATISTICS PRELIMINARY ANALYSIS MEAN SPEED REDUCTION ANALYSIS STANDARD DEVIATION DIFFERENCE ANALYSIS . . 80 . 88 . . 91 VII SUMMARY AND CONCLUSIONS 93 CONCLUSIONS . RECOMMENDATIONS 95 97 REFERENCES APPENDIX . . VITA 100 I04 117 LIST...

Collins, Jon Michael

2012-06-07T23:59:59.000Z

227

WAVE SPEEDS FOR AN ELASTOPLASTIC MODEL FOR TWODIMENSIONAL DEFORMATIONS WITH A NONASSOCIATIVE FLOW RULE  

E-Print Network [OSTI]

WAVE SPEEDS FOR AN ELASTOPLASTIC MODEL FOR TWODIMENSIONAL DEFORMATIONS WITH A NONASSOCIATIVE FLOW of variables, the character istic speeds of plane wave solutions of the system are computed. For both plastic and elastic deformations, there are two nonzero wave speeds, referred to as fast and slow waves. It is shown

228

Evaluation of alignment indices in estimating tangent speeds on rural two-lane highways  

E-Print Network [OSTI]

The design-speed concept has been used in attempting to ensure design and operating-speed consistency of roads in the United States, However, this concept has no effective controls on maximum speeds (e.g., tangents), which reduces its effectiveness...

Parma, Kelly Daniel

1997-01-01T23:59:59.000Z

229

A Robust STATCOM Control to Augment LVRT capability of Fixed Speed Wind Turbines  

E-Print Network [OSTI]

A Robust STATCOM Control to Augment LVRT capability of Fixed Speed Wind Turbines M. J. Hossain, H Compensator (STATCOM) to enhance the Low-Voltage Ride- Through (LVRT) capability of fixed-speed wind turbines cost and maintenance due to rugged brushless construction. Constant speed wind turbines equipped

Pota, Himanshu Roy

230

Rain splash of dry sand revealed by high-speed imaging and sticky paper splash targets  

E-Print Network [OSTI]

Rain splash of dry sand revealed by high-speed imaging and sticky paper splash targets David Jon by raindrop impacts. We use high-speed imaging of drop impacts on dry sand to describe the drop (2007), Rain splash of dry sand revealed by high-speed imaging and sticky paper splash targets, J

231

Control strategy of a variable speed wind turbine with multipole permanent magnet synchronous generator  

E-Print Network [OSTI]

values. Keywords: permanent magnet synchronous generator, variable speed wind turbine, direct driven wind). A multipole synchronous generator connected to a power converter can operate at low speeds, so that a gear canControl strategy of a variable speed wind turbine with multipole permanent magnet synchronous

232

Simultaneous Retreival of Surface Wind Speed and Rain Rate using Radar and Radiometer Measurements  

E-Print Network [OSTI]

to simultaneously retrieve the vertical profile of precipitation and the near-surface wind speed. ResultsSimultaneous Retreival of Surface Wind Speed and Rain Rate using Radar and Radiometer Measurements simultaneously estimates the over ocean near-surface wind speed and rain rate profile using data from a 10.7 GHz

Ruf, Christopher

233

Table 1. Design specifications of ultra-high speed PM motor. Supply voltage (V) 12  

E-Print Network [OSTI]

) 1500 Rated torque (Nm) 0.0955 Rated speed (r/min) 150,000 Stator Core Permanent Magnet Shaft Coil Analysis of Ultra-High Speed Permanent-Magnet Motor Masaru Kano, and Toshihiko Noguchi Department@vos.nagaokaut.ac.jp Abstract This paper describes a design of an ultra-high speed (UHS) permanent-magnet (PM) synchronous motor

Fujimoto, Hiroshi

234

Coal-fueled high-speed diesel engine development. Final report, September 28, 1990--November 30, 1993  

SciTech Connect (OSTI)

The goal of this program was to study the feasibility of operating a Detroit Diesel Series 149 engine at high speeds using a Coal-Water-Slurry (CWS) fuel. The CWS-fueled 149 engine is proposed for the mine-haul off-highway truck and work boat marine markets. Economic analysis studies indicate that, for these markets, the use of CWS fuel could have sufficient operating cost savings, depending upon the future diesel fuel price, emission control system capital and operating costs, and maintenance and overhaul costs. A major portion of the maintenance costs is expected to be due to lower life and higher cost of the CWS injectors. Injection and combustion systems were specially designed for CWS, and were installed in one cylinder of a Detroit Diesel 8V-149TI engine for testing. The objective was to achieve engine operation for sustained periods at speeds up to 1,900 rpm with reasonable fuel economy and coal burnout rate. A computer simulation predicted autoignition of coal fuel at 1,900 rpm would require an average droplet size of 18 microns and 19:1 compression ratio, so the injection system, and pistons were designed accordingly. The injection system was capable of supplying the required volume of CWS/injection with a duration of approximately 25 crank angle degrees and peak pressures on the order of 100 mpa. In addition to the high compression ratio, the combustion system also utilized hot residual gases in the cylinder, warm inlet air admission and ceramic insulated engine components to enhance combustion. Autoignition of CWS fuel was achieved at 1900 rpm, at loads ranging from 20--80 percent of the rated load of diesel-fuel powered cylinders. Limited emissions data indicates coal burnout rates in excess of 99 percent. NO{sub x} levels were significantly lower, while unburned hydrocarbon levels were higher for the CWS fueled cylinder than for corresponding diesel-fuel powered cylinders.

Kakwani, R.M.; Winsor, R.E.; Ryan, T.W. III; Schwalb, J.A.; Wahiduzzaman, S.; Wilson, R.P. Jr.

1993-09-01T23:59:59.000Z

235

The high-speed after pulse measurement system for PMT  

E-Print Network [OSTI]

A system employing a desktop FADC has been developed to investigate the features of 8 inches Hamamatsu PMT. The system stands out for its high-speed and informative results as a consequence of adopting fast waveform sampling technology. Recording full waveforms allows us to perform digital signal processing, pulse shape analysis, and precision timing extraction. High precision after pulse time and charge distribution characteristics are presented in this manuscript. Other photomultipliers characteristics, such as dark rate and transit time spread, can also be obtained by exploiting waveform analysis using this system.

Yaping Cheng; Sen Qian; Zhe Ning; Jingkai Xia; Wenwen Wang; Yifang Wang; Jun Cao; Xiaoshan Jiang; Zheng Wang; Xiaonan Li; Ming Qi; Yuekun Heng; Shulin Liu; Xiangcui Lei; Zhi Wu

2014-04-24T23:59:59.000Z

236

VERY HIGH-SPEED DRILL STRING COMMUNICATIONS NETWORK  

SciTech Connect (OSTI)

Testing of a high-speed digital data transmission system for drill pipe is described. Passive transmission of digital data through 1000 ft of telemetry drill pipe has been successfully achieved. Data rates of up to 2 Mbit/sec have been tested through the 1000 ft system with very low occurrence of data errors: required error correction effort is very low or nonexistent. Further design modifications have been made to improve manufacturability and high pressure robustness of the transmission line components. Failure mechanisms of previous designs at high pressure and high temperature are described. Present design limitations include high temperature application.

David S. Pixton

2002-11-01T23:59:59.000Z

237

Software speeds detection of diseases and cancer-treatment targets  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBiSite CulturalDepartment ofat HomeAssurance: DOE NSoftware speeds

238

Software speeds detection of diseases and cancer-treatment targets  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future | Department of HowSoftware speeds

239

High-speed micro-electro-discharge machining.  

SciTech Connect (OSTI)

When two electrodes are in close proximity in a dielectric liquid, application of a voltage pulse can produce a spark discharge between them, resulting in a small amount of material removal from both electrodes. Pulsed application of the voltage at discharge energies in the range of micro-Joules results in the continuous material removal process known as micro-electro-discharge machining (micro-EDM). Spark erosion by micro-EDM provides significant opportunities for producing small features and micro-components such as nozzle holes, slots, shafts and gears in virtually any conductive material. If the speed and precision of micro-EDM processes can be significantly enhanced, then they have the potential to be used for a wide variety of micro-machining applications including fabrication of microelectromechanical system (MEMS) components. Toward this end, a better understanding of the impacts the various machining parameters have on material removal has been established through a single discharge study of micro-EDM and a parametric study of small hole making by micro-EDM. The main avenues for improving the speed and efficiency of the micro-EDM process are in the areas of more controlled pulse generation in the power supply and more controlled positioning of the tool electrode during the machining process. Further investigation of the micro-EDM process in three dimensions leads to important design rules, specifically the smallest feature size attainable by the process.

Chandrasekar, Srinivasan Dr. (.School of Industrial Engineering, West Lafayette, IN); Moylan, Shawn P. (School of Industrial Engineering, West Lafayette, IN); Benavides, Gilbert Lawrence

2005-09-01T23:59:59.000Z

240

Hi-Q Rotor - Low Wind Speed Technology  

SciTech Connect (OSTI)

The project objective was to optimize the performance of the Hi-Q Rotor. Early research funded by the California Energy Commission indicated the design might be advantageous over state-of-the-art turbines for collecting wind energy in low wind conditions. The Hi-Q Rotor is a new kind of rotor targeted for harvesting wind in Class 2, 3, and 4 sites, and has application in areas that are closer to cities, or 'load centers.' An advantage of the Hi-Q Rotor is that the rotor has non-conventional blade tips, producing less turbulence, and is quieter than standard wind turbine blades which is critical to the low-wind populated urban sites. Unlike state-of-the-art propeller type blades, the Hi-Q Rotor has six blades connected by end caps. In this phase of the research funded by DOE's Inventions and Innovation Program, the goal was to improve the current design by building a series of theoretical and numeric models, and composite prototypes to determine a best of class device. Development of the rotor was performed by aeronautical engineering and design firm, DARcorporation. From this investigation, an optimized design was determined and an 8-foot diameter, full-scale rotor was built and mounted using a Bergey LX-1 generator and furling system which were adapted to support the rotor. The Hi-Q Rotor was then tested side-by-side against the state-of-the-art Bergey XL-1 at the Alternative Energy Institute's Wind Test Center at West Texas State University for six weeks, and real time measurements of power generated were collected and compared. Early wind tunnel testing showed that the cut-in-speed of the Hi-Q rotor is much lower than a conventional tested HAWT enabling the Hi-Q Wind Turbine to begin collecting energy before a conventional HAWT has started spinning. Also, torque at low wind speeds for the Hi-Q Wind Turbine is higher than the tested conventional HAWT and enabled the wind turbine to generate power at lower wind speeds. Based on the data collected, the results of our first full-scale prototype wind turbine proved that higher energy can be captured at lower wind speeds with the new Hi-Q Rotor. The Hi-Q Rotor is almost 15% more productive than the Bergey from 6 m/s to 8 m/s, making it ideal in Class 3, 4, and 5 wind sites and has application in the critical and heretofore untapped areas that are closer to cities, 'load centers,' and may even be used directly in urban areas. The additional advantage of the Hi-Q Rotor's non-conventional blade tips, which eliminates most air turbulence, is noise reduction which makes it doubly ideal for populated urban areas. Hi-Q Products recommends one final stage of development to take the Hi-Q Rotor through Technology Readiness Levels 8-9. During this stage of development, the rotor will be redesigned to further increase efficiency, match the rotor to a more suitable generator, and lower the cost of manufacturing by redesigning the structure to allow for production in larger quantities at lower cost. Before taking the rotor to market and commercialization, it is necessary to further optimize the performance by finding a better generator and autofurling system, ones more suitable for lower wind speeds and rpms should be used in all future testing. The potential impact of this fully developed technology will be the expansion and proliferation of energy renewal into the heretofore untapped Class 2, 3, 4, and 5 Wind Sites, or the large underutilized sites where the wind speed is broken by physical features such as mountains, buildings, and trees. Market estimates by 2011, if low wind speed technology can be developed are well above: 13 million homes, 675,000 commercial buildings, 250,000 public facilities. Estimated commercial exploitation of the Hi-Q Rotor show potential increase in U.S. energy gained through the clean, renewable wind energy found in low and very low wind speed sites. This new energy source would greatly impact greenhouse emissions as well as the public sector's growing energy demands.

Todd E. Mills; Judy Tatum

2010-01-11T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Precision electronic speed controller for an alternating-current  

DOE Patents [OSTI]

A high precision controller for an alternating-current multi-phase electrical motor that is subject to a large inertial load. The controller was developed for and is particularly suitable for controlling, in a neutron chopper system, a heavy spinning rotor that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal having a meandering line frequency. The controller includes a shaft revolution sensor which provides a feedback pulse train representative of the actual speed of the motor. An internal digital timing signal generator provides a reference signal which is compared with the feedback signal in a computing unit to provide a motor control signal. In the preferred embodiment, the motor control signal is a weighted linear sum of a speed error voltage, a phase error voltage, and a drift error voltage, each of which is computed anew with each revolution of the motor shaft. The stator windings of the motor are driven by two amplifiers which are provided with input signals having the proper quadrature relationship by an exciter unit consisting of a voltage controlled oscillator, a binary counter, a pair of readonly memories, and a pair of digital-to-analog converters.

Bolie, Victor W. (Albuquerque, NM)

1988-01-01T23:59:59.000Z

242

Advanced Ultra-High Speed Motor for Drilling  

SciTech Connect (OSTI)

Three (3) designs have been made for two sizes, 6.91 cm (2.72 inch) and 4.29 cm (1.69 inch) outer diameters, of a patented inverted configured Permanent Magnet Synchronous Machines (PMSM) electric motor specifically for drilling at ultra-high rotational speeds (10,000 rpm) and that can utilize advanced drilling methods. Benefits of these motors are stackable power sections, full control (speed and direction) of downhole motors, flow hydraulics independent of motor operation, application of advanced drilling methods (water jetting and abrasive slurry jetting), and the ability of signal/power electric wires through motor(s). Key features of the final designed motors are: fixed non-rotating shaft with stator coils attached; rotating housing with permanent magnet (PM) rotor attached; bit attached to rotating housing; internal channel(s) in a nonrotating shaft; electric components that are hydrostatically isolated from high internal pressure circulating fluids ('muds') by static metal to metal seals; liquid filled motor with smoothed features for minimized turbulence in the motor during operation; and new inverted coated metal-metal hydrodynamic bearings and seals. PMSM, Induction and Switched Reluctance Machines (SRM), all pulse modulated, were considered, but PMSM were determined to provide the highest power density for the shortest motors. Both radial and axial electric PMSM driven motors were designed with axial designs deemed more rugged for ultra-high speed, drilling applications. The 6.91 cm (2.72 inch) OD axial inverted motor can generate 4.18KW (5.61 Hp) power at 10,000 rpm with a 4 Nm (2.95 ft-lbs) of torque for every 30.48 cm (12 inches) of power section. The 6.91 cm (2.72 inch) OD radial inverted motor can generate 5.03 KW (6.74 Hp) with 4.8 Nm (3.54 ft-lb) torque at 10,000 rpm for every 30.48 cm (12 inches) of power section. The 4.29 cm (1.69 inch) OD radial inverted motor can generate 2.56 KW (3.43 Hp) power with 2.44 Nm (1.8 ft-lb) torque at full speed 10,000 rpm for every 30.48 cm (12 inches) of power section. Operating conditions are 300 voltage AC at the motor leads. Power voltage losses in the cables/wirelines to the motor(s) are expected to be about 10% for 5000 feet carrying 2 amperes. Higher voltages and better insulators can lower these losses and carry more amperes. Cutting elements for such high tip velocities are currently not available, consequently these motors will not be built at this time. However, 7.62 cm (3 inch) OD, low speed, PMSM radial electric motors based on this project design are being built under a 2006 Oklahoma Center for the Advancement of Science and Technology 'proof of concept' grant.

Impact Technologies LLC; University of Texas at Arlington

2007-03-31T23:59:59.000Z

243

Control strategy for variable-speed, stall-regulated wind turbines  

SciTech Connect (OSTI)

A variable-speed, constant-pitch wind turbine was investigated to evaluate the feasibility of constraining its rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracted by the blades from the wind was manipulated. Specifically, the blades were caused to stall in high winds. In low and moderate winds, the demanded generator torque and the resulting rotor speed were controlled to cause the wind turbine to operate near maximum efficiency. A computational model was developed, and simulations were conducted of operation in high turbulent winds. Results indicated that rotor speed and power output were well regulated. 7 refs., 7 figs.

Muljadi, E.; Pierce, K.; Migliore, P.

1998-04-01T23:59:59.000Z

244

Development of a New Flame Speed Vessel to Measure the Effect of Steam Dilution on Laminar Flame Speeds of Syngas Fuel Blends at Elevated Pressures and Temperatures  

E-Print Network [OSTI]

/s to 16.7 cm/s. The amount of carbon monoxide dilution in the fuel was shown to be the most influential factor on the laminar flame speed from fuel lean to fuel rich. This is verified by comparing the laminar flame speed of the atmospheric mixtures. Also...

Krejci, Michael

2012-07-16T23:59:59.000Z

245

DIRECT REGULATION OF LARGE SPEED EXCURSIONS FOR VARIABLE SPEED WIND W. E. Leithead, D. J. Leith, F. Hardan, H.Markou  

E-Print Network [OSTI]

the rotor blades at the maximum permissible rate, thereby exploiting the maximum capability of the actuation to adjust the pitch angle of the rotor blades to maintain the peak rotor speed excursion below 15 turbine aims to maintain the rotor speed within a permitted range. However, this requirement can

Duffy, Ken

246

High speed two-dimensional optical beam position detector  

SciTech Connect (OSTI)

Disclosed is the design of a high speed two-dimensional optical beam position detector which outputs the X and Y displacement and total intensity linearly. The experimental detector measures the displacement from DC to 123 MHz and the intensity of an optical spot in a similar way as a conventional quadrant photodiode detector. The design uses four discrete photodiodes and simple dedicated optics for the position decomposition which enables higher spatial accuracy and faster electronic processing than conventional detectors. Measurements of the frequency response and the spatial sensitivity demonstrate high suitability for atomic force microscopy, scanning probe data storage applications, and wideband wavefront sensing. The operation principle allows for position measurements up to 20 GHz and more in bandwidth.

Rutten, Paul Edmond [Maypa B.V., Bijsters 2, 5131 NW, Alphen (Netherlands)

2011-07-15T23:59:59.000Z

247

On the Convergence Speed of Turbo Demodulation with Turbo Decoding  

E-Print Network [OSTI]

Iterative processing is widely adopted nowadays in modern wireless receivers for advanced channel codes like turbo and LDPC codes. Extension of this principle with an additional iterative feedback loop to the demapping function has proven to provide substantial error performance gain. However, the adoption of iterative demodulation with turbo decoding is constrained by the additional implied implementation complexity, heavily impacting latency and power consumption. In this paper, we analyze the convergence speed of these combined two iterative processes in order to determine the exact required number of iterations at each level. Extrinsic information transfer (EXIT) charts are used for a thorough analysis at different modulation orders and code rates. An original iteration scheduling is proposed reducing two demapping iterations with reasonable performance loss of less than 0.15 dB. Analyzing and normalizing the computational and memory access complexity, which directly impact latency and power consumption, ...

Haddad, Salim; Jezequel, Michel

2012-01-01T23:59:59.000Z

248

High speed infrared radiation thermometer, system, and method  

DOE Patents [OSTI]

The high-speed radiation thermometer has an infrared measurement wavelength band that is matched to the infrared wavelength band of near-blackbody emittance of ceramic components and ceramic thermal barrier coatings used in turbine engines. It is comprised of a long wavelength infrared detector, a signal amplifier, an analog-to-digital converter, an optical system to collect radiation from the target, an optical filter, and an integral reference signal to maintain a calibrated response. A megahertz range electronic data acquisition system is connected to the radiation detector to operate on raw data obtained. Because the thermometer operates optimally at 8 to 12 .mu.m, where emittance is near-blackbody for ceramics, interferences to measurements performed in turbine engines are minimized. The method and apparatus are optimized to enable mapping of surface temperatures on fast moving ceramic elements, and the thermometer can provide microsecond response, with inherent self-diagnostic and calibration-correction features.

Markham, James R. (Middlefield, CT)

2002-01-01T23:59:59.000Z

249

A conservative control strategy for variable-speed stall-regulated wind turbines  

SciTech Connect (OSTI)

Simulation models of a variable-speed, fixed-pitch wind turbine were investigated to evaluate the feasibility of constraining rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracted by the blades from the wind was manipulated. Specifically, the blades were caused to stall in high winds. In low and moderate winds, the demanded generator torque and the resulting rotor speed were controlled to cause the wind turbine to operate near maximum efficiency. Using the developed models, simulations were conducted of operation in turbulent winds. Results indicated that rotor speed and power output were well regulated. Preliminary investigations of system dynamics showed that, compared to fixed-speed operation, variable-speed operation caused cyclic loading amplitude to be reduced for the turbine blades and low-speed shaft and slightly increased for the tower loads. This result suggests a favorable impact on fatigue life from implementation of the proposed control strategy.

Muljadi, E.; Pierce, K.; Migliore, P.

2000-02-08T23:59:59.000Z

250

An examination of loads and responses of a wind turbine undergoing variable-speed operation  

SciTech Connect (OSTI)

The National Renewable Energy Laboratory has recently developed the ability to predict turbine loads and responses for machines undergoing variable-speed operation. The wind industry has debated the potential benefits of operating wind turbine sat variable speeds for some time. Turbine system dynamic responses (structural response, resonance, and component interactions) are an important consideration for variable-speed operation of wind turbines. The authors have implemented simple, variable-speed control algorithms for both the FAST and ADAMS dynamics codes. The control algorithm is a simple one, allowing the turbine to track the optimum power coefficient (C{sub p}). The objective of this paper is to show turbine loads and responses for a particular two-bladed, teetering-hub, downwind turbine undergoing variable-speed operation. The authors examined the response of the machine to various turbulent wind inflow conditions. In addition, they compare the structural responses under fixed-speed and variable-speed operation. For this paper, they restrict their comparisons to those wind-speed ranges for which limiting power by some additional control strategy (blade pitch or aileron control, for example) is not necessary. The objective here is to develop a basic understanding of the differences in loads and responses between the fixed-speed and variable-speed operation of this wind turbine configuration.

Wright, A.D.; Buhl, M.L. Jr.; Bir, G.S.

1996-11-01T23:59:59.000Z

251

Liquid and liquidgas flows at all speeds  

SciTech Connect (OSTI)

All speed flows and in particular low Mach number flow algorithms are addressed for the numerical approximation of the Kapila et al. [1] multiphase flow model. This model is valid for fluid mixtures evolving in mechanical equilibrium but out of temperature equilibrium and is efficient for material interfaces computation separating miscible and non-miscible fluids. In this context, the interface is considered as a numerically diffused zone, captured as well as all present waves (shocks, expansion waves). The same flow model can be used to solve cavitating and boiling flows [2]. Many applications occurring with liquidgas interfaces and cavitating flows involve a very wide range of Mach number, from 10{sup ?3} to supersonic (and even hypersonic) conditions with respect to the mixture sound speed. It is thus important to address numerical methods free of restrictions regarding the Mach number. To do this, a preconditioned Riemann solver is built and embedded into the Godunov explicit scheme. It is shown that this method converges to exact solutions but needs too small time steps to be efficient. An implicit version is then derived, first in one dimension and second in the frame of 2D unstructured meshes. Two-phase flow preconditioning is then addressed in the frame of the Saurel et al. [3] algorithm. Modifications of the preconditioned Riemann solver are needed and detailed. Convergence of both single phase and two-phase numerical solutions are demonstrated with the help of single phase and two-phase steady nozzle flow solutions. Last, the method is illustrated by the computation of real cavitating flows in Venturi nozzles. Vapour pocket size and instability frequencies are reproduced by the model and method without using any adjustable parameter.

LeMartelot, S., E-mail: sebastien.lemartelot@polytech.univ-mrs.fr [Polytech'Marseille, Aix-Marseille University, UMR CNRS 7343 IUSTI, 5 rue E. Fermi, 13453 Marseille Cedex 13 (France); Nkonga, B., E-mail: boniface.nkonga@unice.fr [RS2N, Bastidon de la Caou, 13360 Roquevaire (France); University of Nice, LJAD UMR CNRS 7351, Parc Valrose, 06108 Nice Cedex (France); Saurel, R., E-mail: richard.saurel@polytech.univ-mrs.fr [Polytech'Marseille, Aix-Marseille University, UMR CNRS 7343 IUSTI, 5 rue E. Fermi, 13453 Marseille Cedex 13 (France); RS2N, Bastidon de la Caou, 13360 Roquevaire (France); University Institute of France, 5 rue E. Fermi, 13453 Marseille Cedex 13 (France)

2013-12-15T23:59:59.000Z

252

An investigation of irregular switching in three phase adjustable speed motor drives without neutral connection  

E-Print Network [OSTI]

Phase Adjustable Speed Motor Drives without Neutral Connection. (May 1990) Md. Shamsul Arefeen, B. S. , Bangladesh Univ. of Engg. 8z Technology Chair of Advisory Committee: Dr. M. Ehsani There are many industrial applications where variable speed... There are many industrial application where variable speed drives of electrical ma, - chines are needed. This requirement of high performance electric drives can be met either by a. dc or by an ac machine. Due to cost and ease of control, high performance...

Arefeen, Shamsal

1990-01-01T23:59:59.000Z

253

Turbulent Flame Speeds and NOx Kinetics of HHC Fuels with Contaminants and High Dilution Levels  

SciTech Connect (OSTI)

This final report documents the technical results of the 3-year project entitled, Turbulent Flame Speeds and NOx Kinetics of HHC Fuels with Contaminants and High Dilution Levels, funded under the NETL of DOE. The research was conducted under six main tasks: 1) program management and planning; 2) turbulent flame speed measurements of syngas mixtures; 3) laminar flame speed measurements with diluents; 4) NOx mechanism validation experiments; 5) fundamental NOx kinetics; and 6) the effect of impurities on NOx kinetics. Experiments were performed using primary constant-volume vessels for laminar and turbulent flame speeds and shock tubes for ignition delay times and species concentrations. In addition to the existing shock- tube and flame speed facilities, a new capability in measuring turbulent flame speeds was developed under this grant. Other highlights include an improved NOx kinetics mechanism; a database on syngas blends for real fuel mixtures with and without impurities; an improved hydrogen sulfide mechanism; an improved ammonia kintics mechanism; laminar flame speed data at high pressures with water addition; and the development of an inexpensive absorption spectroscopy diagnostic for shock-tube measurements of OH time histories. The Project Results for this work can be divided into 13 major sections, which form the basis of this report. These 13 topics are divided into the five areas: 1) laminar flame speeds; 2) Nitrogen Oxide and Ammonia chemical kinetics; 3) syngas impurities chemical kinetics; 4) turbulent flame speeds; and 5) OH absorption measurements for chemical kinetics.

Peterson, Eric; Krejci, Michael; Mathieu, Olivier; Vissotski, Andrew; Ravi, Sankat; Plichta, Drew; Sikes, Travis; Levacque, Anthony; Camou, Alejandro; Aul, Christopher

2013-09-30T23:59:59.000Z

254

High-Speed Tandem Mass Spectrometric in Situ Imaging by Nanospray...  

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

in Situ Imaging by Nanospray Desorption Electrospray Ionization Mass Spectrometry. High-Speed Tandem Mass Spectrometric in Situ Imaging by Nanospray Desorption Electrospray...

255

Photo of the Week: Faster than the Speed of Light | Department...  

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

Super HILAC (Super Heavy Ion Linear Accelerator) was one of the first particle accelerators that could accelerate heavier elements to "atom-smashing" speeds. The device was...

256

Speed And Power Control Of An Engine By Modulation Of The Load Torque  

DOE Patents [OSTI]

A system and method of speed and power control for an engine in which speed and power of the engine is controlled by modulation of the load torque. The load torque is manipulated in order to cause engine speed, and hence power to be changed. To accomplish such control, the load torque undergoes a temporary excursion in the opposite direction of the desired speed and power change. The engine and the driven equipment will accelerate or decelerate accordingly as the load torque is decreased or increased, relative to the essentially fixed or constant engine torque. As the engine accelerates or decelerates, its power increases or decreases in proportion.

Ziph, Benjamin (Ann Arbor, MI); Strodtman, Scott (Ypsilanti, MI); Rose, Thomas K (Chelsea, MI)

1999-01-26T23:59:59.000Z

257

Range-Renewal Speed and Entropy for I.I.D Models  

E-Print Network [OSTI]

In this note the relation between the range-renewal speed and entropy for i.i.d. models is discussed.

Xin-Xing Chen; Jian-Sheng Xie; Jiangang Ying

2013-05-24T23:59:59.000Z

258

Recovery of a source term or a speed with one measurement and  

E-Print Network [OSTI]

Apr 3, 2013 ... version, of the problem of recovery a sound speed, given the source. It has applications to thermoacoustic tomography. We are also inspired by...

2013-04-03T23:59:59.000Z

259

Variable speed drive as an alternative solution for a micro-hydro power plant.  

E-Print Network [OSTI]

?? This diploma work is mainly focused on developing the control strategy for avariable speed drive as an alternative solution to a micro-hydro power plant. (more)

Akhtar, Malik Usman

2012-01-01T23:59:59.000Z

260

Sensorless Speed Control of Permanent Magnet-Assisted Synchronous Reluctance Motor (PMa-SynRM)  

E-Print Network [OSTI]

Page 5-17 (From top to bottom) Phase A current (DSP)-[1V/div], q-axis and d-axis currents-[1V/div] when motor speed is changed from 130RPM to 10RPM and back to 130RPM... torque at standstill (i.e., zero speed) and low speeds as well as constant output power over wide speed range. In order to meet these requirements, the PMa-SynRM machines are designed to operate not only in the constant torque region where the motor...

Chakali, Anil K.

2011-02-22T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Peak Power Bi-directional Transfer From High Speed Flywheel to Electrical Regulated Bus Voltage System  

E-Print Network [OSTI]

were performed to determine the energy transfer capabilities of a flywheel coupled high speed permanent magnet synchronous machine through the proposed system's energy storage tank. Results are presented

Szabados, Barna

262

E-Print Network 3.0 - automatic speed control Sample Search Results  

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

by setting the speed of the infusion pump... . This paper describes an application of fuzzy logic in ... Source: Belohlavek, Radim - Department of Computer Science, Palack...

263

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

DOE Patents [OSTI]

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

Milleron, Norman (1854 San Juan, Berkeley, CA 94707)

1983-01-01T23:59:59.000Z

264

CHI-SQUARE TEST STATISTICS AND DERIVED MEASURES OF EFFECT FOR VARIOUS BIRDS  

E-Print Network [OSTI]

Rotor orientation to wind * Faces wind 22 29.80 0.74 -14 Away from wind 32 21.99 1.46 19 Vertical axis 0.20 1.35 3 31.4 ­ ­33.2 2 0.81 2.47 2 Blade tip speed (kph)t 136.77 0 0.62 0 -1 143.20 1 0.89 1.12 0 146 Accountable percent 212.39 0 0.06 0 0 239.74 2 0.24 8.20 3 246.18 30 27.30 1.10 5 Blade tip speed (kph) 137

265

Multiwave imaging in an enclosure with variable wave speed  

E-Print Network [OSTI]

In this paper we consider the mathematical model of thermo- and photo-acoustic tomography for the recovery of the initial condition of a wave field from knowledge of its boundary values. Unlike the free-space setting, we consider the wave problem in a region enclosed by a surface where an impedance boundary condition is imposed. This condition models the presence of physical boundaries such as interfaces or acoustic mirrors which reflect some of the wave energy back into the enclosed domain. By recognizing that the inverse problem is equivalent to a statement of boundary observability, we use control operators to prove the unique and stable recovery of the initial wave profile from knowledge of boundary measurements. Since our proof is constructive, we explicitly derive a solvable equation for the unknown initial condition. This equation can be solved numerically using the conjugate gradient method. We also propose an alternative approach based on the stabilization of waves. This leads to an exponentially and uniformly convergent Neumann series reconstruction when the impedance coefficient is not identically zero. In both cases, if well-known geometrical conditions are satisfied, our approaches are naturally suited for variable wave speed and for measurements on a subset of the boundary.

Sebastian Acosta; Carlos Montalto

2015-04-10T23:59:59.000Z

266

Effects of Relativity Lead to"Warp Speed" Computations  

SciTech Connect (OSTI)

A scientist at Lawrence Berkeley National Laboratory has discovered that a previously unnoticed consequence of Einstein's special theory of relativity can lead to speedup of computer calculations by orders of magnitude when applied to the computer modeling of a certain class of physical systems. This new finding offers the possibility of tackling some problems in a much shorter time and with far more precision than was possible before, as well as studying some configurations in every detail for the first time. The basis of Einstein's theory is the principle of relativity, which states that the laws of physics are the same for all observers, whether the 'observer' is a turtle 'racing' with a rabbit, or a beam of particles moving at near light speed. From the invariance of the laws of physics, one may be tempted to infer that the complexity of a system is independent of the motion of the observer, and consequently, a computer simulation will require the same number of mathematical operations, independently of the reference frame that is used for the calculation. Length contraction and time dilation are well known consequences of the special theory of relativity which lead to very counterintuitive effects. An alien observing human activity through a telescope in a spaceship traveling in the Vicinity of the earth near the speed of light would see everything flattened in the direction of propagation of its spaceship (for him, the earth would have the shape of a pancake), while all motions on earth would appear extremely slow, slowed almost to a standstill. Conversely, a space scientist observing the alien through a telescope based on earth would see a flattened alien almost to a standstill in a flattened spaceship. Meanwhile, an astronaut sitting in a spaceship moving at some lower velocity than the alien spaceship with regard to earth might see both the alien spaceship and the earth flattened in the same proportion and the motion unfolding in each of them at the same speed. Let us now assume that each protagonist (the alien, the space scientist and the astronaut) is to run a computer simulation describing the motion of all of them in a single calculation. In order to model a physical system on a computer, scientists often divide space and time into small chunks. Since the computer must calculated some things for each chunk, having a large system containing numerous small chunks translates to long calculations requiring many computational steps on supercomputers. Let us assume that each protagonist of our intergalactic story uses the space and time slicing as described and chooses to perform the calculation in its own frame of reference. For the alien and the space scientist, the slicing of space and time results in an exceedingly large number of chunks, due to the wide disparity of spatial and time scales needed to describe both their own environment and motion together with the other extremely flattened environment and slowed motion. Since the disparity of scales is reduced for the astronaut, who is traveling at an intermediate velocity, the number of computer operations needed to complete the calculation in his frame of reference will be significantly lower, possibly by many orders of magnitude. Analogously, the new discovery at Lawrence Berkeley National Laboratory shows that there exists a frame of reference minimizing the number of computational operations needed for studying the interaction of beams of particles or light (lasers) interacting at, or near, light speed with other particles or with surrounding structures. Speedups ranging from ten to a million times or more are predicted for the modeling of beams interacting with electron clouds, such as those in the upcoming Large Hadron Collider 'atom smasher' accelerator at CERN (Switzerland), and in free electron lasers and tabletop laser wakefield accelerators. The discovery has surprised many physicists and was received initially with much skepticism. It sounded too much like a 'free lunch'. Yet, the demonstration of a speedup of a stunning one thousand times in a te

Vay, J.-L.

2007-11-01T23:59:59.000Z

267

Shift mechanism for change-speed gearing in power transmission  

SciTech Connect (OSTI)

This patent describes a shift mechanism for a change-speed gearing in a power transmission, comprising: an actuator mounted on a support structure; a shift rod axially slidably carried on the support structure and operatively connected at a first end for reciprocating movement; means for selectively establishing a drive power gear train in response to the reciprocating movement where the support structure is formed at one side with a cylindrical portion is formed axially to contain a second end of the shift rod; a plug detachably threaded into the cylindrical portion of the support structure so as to close the axial bore, a coil spring disposed within the axial bore of the cylindrical portion and arranged in surrounding relationship with the shift rod in such a manner as to permit unbiased reciprocating movement of the shift rod within the coil spring; and a retainer interposed between the coil spring and the plug in such a manner that the coil spring is compressed by engagement at a first end. The inner end of the axial bore and second end are with the retainer; further arranged to be engaged with the second end of the shift rod when the plug is removed and fastened again in place. The coil spring is arranged to retain the shift rod in a rearward position when interposed between the retainer and the plug.

Ida, S.; Shimizu, K.; Hotta, J.

1987-06-30T23:59:59.000Z

268

Possible Origin Of The Neutrino Speed Anomaly Reported By OPERA  

E-Print Network [OSTI]

Recently the OPERA collaboration reported a measurement of a superluminal speed of muon neutrinos travelling through the Earth's crust between their production site at CERN and their detection site under Gran Sasso, ~730 km away. The measurement was based on the assumption that the pulse shape of the neutrinos from the decay of parent mesons produced in proton-target collisions is the same as that of the incident protons. Here we argue that the effective column density of the target along the beam direction decreases with time during the 10.5 microseconds duration of the proton pulse. This is because of the thermal expansion and expulsion of target material along the beam by the energy-momentum deposition during the 10.5 microseconds pulse. The progresive reduction in the effective column density during the pulse decreases the neutrino production rate per incident proton. It could have advanced the mean production time of the detected neutrinos relative to that calculated from the proton pulse-shape, by an am...

Dado, Shlomo

2011-01-01T23:59:59.000Z

269

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

270

High speed flow cytometer droplet formation system and method  

DOE Patents [OSTI]

A droplet forming flow cytometer system allows high speed processing without the need for high oscillator drive powers through the inclusion of an oscillator or piezoelectric crystal such as within the nozzle volume or otherwise unidirectionally coupled to the sheath fluid. The nozzle container continuously converges so as to amplify unidirectional oscillations which are transmitted as pressure waves through the nozzle volume to the nozzle exit so as to form droplets from the fluid jet. The oscillator is directionally isolated so as to avoid moving the entire nozzle container so as to create only pressure waves within the sheath fluid. A variation in substance concentration is achieved through a movable substance introduction port which is positioned within a convergence zone to vary the relative concentration of substance to sheath fluid while still maintaining optimal laminar flow conditions. This variation may be automatically controlled through a sensor and controller configuration. A replaceable tip design is also provided whereby the ceramic nozzle tip is positioned within an edge insert in the nozzle body so as to smoothly transition from nozzle body to nozzle tip. The nozzle tip is sealed against its outer surface to the nozzle body so it may be removable for cleaning or replacement.

Van den Engh, Ger (Seattle, WA)

2000-01-01T23:59:59.000Z

271

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

272

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

273

Speed-of-light limitations in passive linear media  

E-Print Network [OSTI]

We prove that well-known speed of light restrictions on electromagnetic energy velocity can be extended to a new level of generality, encompassing even nonlocal chiral media in periodic geometries, while at the same time weakening the underlying assumptions to only passivity and linearity of the medium (either with a transparency window or with dissipation). As was also shown by other authors under more limiting assumptions, passivity alone is sufficient to guarantee causality and positivity of the energy density (with no thermodynamic assumptions). Our proof is general enough to include a very broad range of material properties, including anisotropy, bianisotropy (chirality), nonlocality, dispersion, periodicity, and even delta functions or similar generalized functions. We also show that the "dynamical energy density" used by some previous authors in dissipative media reduces to the standard Brillouin formula for dispersive energy density in a transparency window. The results in this paper are proved by exploiting deep results from linear-response theory, harmonic analysis, and functional analysis that had previously not been brought together in the context of electrodynamics.

Aaron Welters; Yehuda Avniel; Steven G. Johnson

2014-05-01T23:59:59.000Z

274

Gauge field, strings, solitons, anomalies and the speed of life  

E-Print Network [OSTI]

It's been said that "mathematics is biology's next microscope, only better; biology is mathematics' next physics, only better". Here we aim for something even better. We try to combine mathematical physics and biology into a picoscope of life. For this we merge techniques which have been introduced and developed in modern mathematical physics, largely by Ludvig Faddeev to describe objects such as solitons and Higgs and to explain phenomena such as anomalies in gauge fields. We propose a synthesis that can help to resolve the protein folding problem, one of the most important conundrums in all of science. We apply the concept of gauge invariance to scrutinize the extrinsic geometry of strings in three dimensional space. We evoke general principles of symmetry in combination with Wilsonian universality and derive an essentially unique Landau-Ginzburg energy that describes the dynamics of a generic string-like configuration in the far infrared. We observe that the energy supports topological solitons, that pertain to an anomaly in the manner how a string is framed around its inflection points. We explain how the solitons operate as modular building blocks from which folded proteins are composed. We describe crystallographic protein structures by multi-solitons with experimental precision, and investigate the non-equilibrium dynamics of proteins under varying temperature. We simulate the folding process of a protein at in vivo speed and with close to pico-scale accuracy using a standard laptop computer: With pico-biology as mathematical physics' next pursuit, things can only get better.

Antti J. Niemi

2014-07-05T23:59:59.000Z

275

Elementary excitations and sound speed in liquid He at negative pressures  

E-Print Network [OSTI]

Elementary excitations and sound speed in liquid 4 He at negative pressures Francesco Albergamoa of positive pressure values and from the sound speed. The maximum negative pressure realized, about -5.5 bar values as the density is decreased below the bulk value due to stretching of the liquid. The negative

Glyde, Henry R.

276

Ris-PhD-Report Accounting for the speed shear in wind  

E-Print Network [OSTI]

Risø-PhD-Report Accounting for the speed shear in wind turbine power performance measurement Rozenn for the speed shear in wind turbine power performance measurement Division: Wind Energy Division Abstract: The power curve of a wind turbine is the primary char- acteristic of the machine as it is the basis

277

Offshore Coastal Wind Speed Gradients: issues for the design and development of large offshore windfarms  

E-Print Network [OSTI]

Offshore Coastal Wind Speed Gradients: issues for the design and development of large offshore@globalnet.co.uk · WEB SITE: www.multi-science.co.uk #12;Offshore Coastal Wind Speed Gradients: issues for the design and development of large offshore windfarms R.J. Barthelmie1,2, J. Badger3, S.C. Pryor2, C.B. Hasager3, M

Pryor, Sara C.

278

Simplified Modelling and Control of a Synchronous Machine with VariableSpeed SixStep Drive  

E-Print Network [OSTI]

of electrical power flow in the machine. Cost is a driving factor in the design of such a system, and the power frequency than PWM as well. II. VARIABLE­SPEED ELECTRIC MACHINE DRIVES While the choice of driveSimplified Modelling and Control of a Synchronous Machine with Variable­Speed Six­Step Drive

Sanders, Seth

279

RESULTS AND DISCUSSION Part II AH-1G ROTOR IN LOW SPEED DESCENT FLIGHT  

E-Print Network [OSTI]

, results are presented for a two-bladed AH-1G rotor in a low-speed descent condition. In low speed forward and Acoustics Test (TAAT) was conducted on an AH-1G Cobra. It used highly instrumented rotor blades direction. The inner Navier-Stokes zone includes about 39% of the total grid points. The rotor has

280

Foraging theory for autonomous vehicle speed choice Theodore P. Pavlic , Kevin M. Passino 1  

E-Print Network [OSTI]

Foraging theory for autonomous vehicle speed choice Theodore P. Pavlic , Kevin M. Passino 1 consider the optimal control design of an abstract autonomous vehicle (AAV). The AAV searches an area cost of depleted vehicle fuel), and search costs depend on search speed. However, the designer rewards

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Design and construction of the high-speed optoelectronic memory system  

E-Print Network [OSTI]

Design and construction of the high-speed optoelectronic memory system demonstrator Roberto-speed optoelectronic memory system project is concerned with the reduction of latency within multiprocessor computer systems (a key problem) by the use of optoelectronics and associated packaging technologies. System

Jahns, Jürgen

282

Automotive speed control and cruise controls. (Bibliography from the Global Mobility database). Published Search  

SciTech Connect (OSTI)

The bibliography contains citations concerning speed controls and cruise controls for automobiles, trucks, and industrial forklifts. Topics include stability analysis, H-infinity control theory, Proportional Integrative Derivative (PID) control, and idle speed control. The use and effect of controls in various highway situations are reviewed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1996-08-01T23:59:59.000Z

283

Modelling and Design Optimization of Low Speed Fuel Cell Hybrid Electric Vehicles  

E-Print Network [OSTI]

optimization of PEM fuel cell power system, and fuel cell powered, low speed electric vehicles. #12;iii TABLEModelling and Design Optimization of Low Speed Fuel Cell Hybrid Electric Vehicles by Matthew Blair Supervisors: Dr. Zuomin Dong ABSTRACT Electric vehicles, as an emerging transportation platform, have been

Victoria, University of

284

On the phase speed and attenuation of an interface wave in an unconsolidated marine sediment  

E-Print Network [OSTI]

of mineral grains b w / 0 density ratio 0 bulk modulus of sediment a Also at: Institute of SoundOn the phase speed and attenuation of an interface wave in an unconsolidated marine sediment for publication 7 June 1999 The phase speed and attenuation of the interface wave at the seawater

Buckingham, Michael

285

Codon-by-Codon Modulation of Translational Speed and Accuracy Via mRNA Folding  

E-Print Network [OSTI]

that mRNA secondary structures serve as elongation brakes to control the speed and hence the fidelity4]. However, several lines of evidence suggest that speedy elongation undermines translational accuracy when of the tradeoff between the speed and accuracy) [7]. Translational errors are harmful, because of the material

Zhang, Jianzhi

286

Tracking an Aerodynamic Model in a Wind Tunnel with a Stereo High-speed Imaging System  

E-Print Network [OSTI]

Tracking an Aerodynamic Model in a Wind Tunnel with a Stereo High-speed Imaging System Lichuan Gui in wind tunnel tests with a stereo high-speed imaging system. The imaging system includes two high angle, pitch angle and yaw angle of the aerodynamic model in the wind tunnel. Tests and simulations were

Gui, Lichuan

287

Status of ORNL/ENEA-Frascati Collaboration on IGNITOR High-Speed Pellet Injector*  

E-Print Network [OSTI]

Status of ORNL/ENEA-Frascati Collaboration on IGNITOR High-Speed Pellet Injector* S. K. Combs, C. R June 15, 2011 #12;2! Background ­ ORNL History with High-Speed Pellet Injection ·Two-stage light gas development ·Accelerated plastic projectiles (4 and 6 mm) up to 5 km/s (single pellets) ·QUICKGUN Algorithm

288

Design of an ambient aerosol sampling system for high and medium speed applications  

E-Print Network [OSTI]

Two ambient sampling systems were designed and tested for high speed sampling application for a wind speed range of 4.47 m/s to 26.82 m/s. These systems will be used as inlets for sampling of bioaerosol from air. These systems consist of shrouded...

Irshad, Hammad

2012-06-07T23:59:59.000Z

289

Euler-Bernoulli Implementation of Spherical Anemometers for High Wind Speed Calculations via Strain Gauges  

E-Print Network [OSTI]

New measuring methods continue to be developed in the field of wind anemometry for various environments subject to low-speed and high-speed flows, turbulent-present flows, and ideal and non-ideal flows. As a result, anemometry has taken different...

Castillo, Davis

2011-08-08T23:59:59.000Z

290

Energy-Efficient Speed Scheduling for Real-Time Tasks under Thermal Constraints  

E-Print Network [OSTI]

Energy-Efficient Speed Scheduling for Real-Time Tasks under Thermal Constraints Shengquan Wang. We develop energy-efficient speed scheduling schemes for frame-based real-time tasks under thermal- sumption with comparison to the reactive schemes in the literature. Keywords: Energy-efficient scheduling

Wang, Shengquan

291

Resolving Spacecraft Earth-Flyby Anomalies with Measured Light Speed Anisotropy  

E-Print Network [OSTI]

Doppler shift observations of spacecraft, such as Galileo, NEAR, Cassini, Rosetta and MESSENGER in earth flybys, have all revealed unexplained speed `anomalies' - that the doppler-shift determined speeds are inconsistent with expected speeds. Here it is shown that these speed anomalies are not real and are actually the result of using an incorrect relationship between the observed doppler shift and the speed of the spacecraft - a relationship based on the assumption that the speed of light is isotropic in all frames, i.e. invariant. Taking account of the repeatedly measured light-speed anisotropy the anomalies are resolved. The Pioneer 10/11 anomalies are discussed, but not resolved. The spacecraft observations demonstrate again that the speed of light is not invariant, and is isotropic only with respect to a dynamical 3-space. The existing doppler shift data also offers a resource to characterise a new form of gravitational waves, the dynamical 3-space turbulence, that has also been detected by other techniques.

Reginald T. Cahill

2008-04-30T23:59:59.000Z

292

Best Practices for Energy Efficient Cleanrooms Efficient HVAC Systems: Variable-Speed-Drive Chillers  

E-Print Network [OSTI]

LBNL-58636 Best Practices for Energy Efficient Cleanrooms Efficient HVAC Systems: Variable Efficient Cleanrooms Efficient HVAC Water Systems: Variable-Speed-Drive Chillers Tengfang Xu Contents HVAC.................................................................................................................................... 6 #12;HVAC Water Systems Variable-Speed-Drive Chillers Summary Cleanroom energy benchmarking data

293

Development of a Dynamic Model of a Small High-Speed Autonomous Underwater Vehicle  

E-Print Network [OSTI]

Development of a Dynamic Model of a Small High-Speed Autonomous Underwater Vehicle Haider N. Arafat-- A dynamic model is developed for a small, high- speed autonomous underwater vehicle. The vehicle has manner: 1) Wind angle and angle : From u = V cos , v = V sin sin , and w = V sin cos , we have tan

Virginia Tech

294

The Effect of Wind Speed and Electric Rates On Wind Turbine Economics  

E-Print Network [OSTI]

The Effect of Wind Speed and Electric Rates On Wind Turbine Economics Economics of wind power depends mainly on the wind speeds and the turbine make and model. Definition: Simple Payback The "Simple period of a small wind power project. All the figures are per turbine, so it can be used for a one, two

Massachusetts at Amherst, University of

295

University of Nevada Las Vegas Arduino Project Report: Fan Speed Control as a Function of Thermistor  

E-Print Network [OSTI]

University of Nevada Las Vegas Arduino Project Report: Fan Speed Control as a Function, and an arduino board. The arduino board is programmed to read the analog input, the thermistor, and respond by the arduino that will decrease the speed of the fan. Furthermore, if the temperature goes up, the resistance

Kachroo, Pushkin

296

Dynamic Motor Parameter Identification for High Speed Flux Weakening Operation of Brushless Permanent Magnet Synchronous Machines  

E-Print Network [OSTI]

performance torque control. Advanced high speed salient-pole synchronous machine drives use vector control Permanent Magnet Synchronous Machines Abstract: An experimental investigation is conducted to determine the behaviour of brushless PM synchronous machine parameters in the high speed flux weakening operating range

Szabados, Barna

297

Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems  

E-Print Network [OSTI]

Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems B. Beltran, T. Ahmed power generation in variable speed wind energy conversion systems (VS-WECS). These systems have two (National Renewable Energy Laboratory) wind turbine simulator FAST (Fatigue, Aerodynamics, Structures

Boyer, Edmond

298

Energy Efficient Control of a Boosting System with Multiple Variable-Speed Pumps in Parallel  

E-Print Network [OSTI]

with multiple variable-speed pumps in parallel is to minimize the pump system energy consumption by controlEnergy Efficient Control of a Boosting System with Multiple Variable-Speed Pumps in Parallel Zhenyu. The experimental results show a huge potential to improve the energy efficiency of multi-pump systems using

Yang, Zhenyu

299

ECEN 720 High-Speed Links: Circuits and Systems Lab1 -Transmission Lines  

E-Print Network [OSTI]

1 ECEN 720 High-Speed Links: Circuits and Systems Lab1 - Transmission Lines Objective To learn about transmission lines and time-domain reflectometer (TDR). Introduction Wires are used to transmit. In high speed data communication chip design, the wires are often treated as transmission lines. Proper

Palermo, Sam

300

Using Electronic Adjustable Speed Drives for Efficiency Improvement and Cost Reduction  

E-Print Network [OSTI]

U.S. industry and utilities have been using ac adjustable speed drives (ASDs) for more than 50 years. ASDs utilize power electronics technology to control the flow of power to an ac motor, thereby controlling the motors speed and rate of energy...

Friedman, N. R.

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

High speed cutting with industrial robots: Towards model based compensation of deviations  

E-Print Network [OSTI]

, [abele|bauer|weigold]@ptw.tu-darmstadt.de Abstract Application of industrial robots for high speedHigh speed cutting with industrial robots: Towards model based compensation of deviations Modeling and numerical simulation of the industrial robot with elastic joints Dr.-Ing. M. Stelzer and Prof. Dr. rer. nat

Stryk, Oskar von

302

Vehicle Speed Estimation using Acoustic Wave Patterns Volkan Cevher, Member, IEEE, Rama Chellappa, Fellow, IEEE  

E-Print Network [OSTI]

1 Vehicle Speed Estimation using Acoustic Wave Patterns Volkan Cevher, Member, IEEE, Rama Chellappa, Fellow, IEEE James H. McClellan, Fellow, IEEE Abstract-- We estimate a vehicle's speed, its wheelbase acoustic sensor that records the vehicle's drive-by noise. The acoustic wave pattern is determined using

Cevher, Volkan

303

Online Speed Scaling Based on Active Job Count to Minimize Flow plus Energy  

E-Print Network [OSTI]

Online Speed Scaling Based on Active Job Count to Minimize Flow plus Energy Tak-Wah Lam Lap-Kei Lee research on online job scheduling has gradually taken speed scaling and energy usage into consideration algorithms that aim at minimizing the total flow time plus energy usage. The results are divided into two

Wong, Prudence W.H.

304

Mechanism design for aggregating energy consumption and quality of service in speed  

E-Print Network [OSTI]

in a way that minimizes energy while respecting the jobs' deadlines. The energy consumption is then chargedScale. Higher speed means that jobs finish earlier at the price of a higher energy consumption. Each job hasMechanism design for aggregating energy consumption and quality of service in speed scaling

Paris-Sud XI, Université de

305

Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization, Comparison, and Bias Reduction  

E-Print Network [OSTI]

data, all from 2000 to 2005. Wind speed mean, 90th percentile, standard deviation, and Weibull shape and energy fluxes depend nonlinearly on wind speed magnitude, are sensitive to the tails of the wind statistics, particularly in the Southern Hemisphere storm track, consistent with the hypothesis. These wind

Zender, Charles

306

Ris-R-Report Analysis of vertical wind direction and speed  

E-Print Network [OSTI]

Risø-R-Report Analysis of vertical wind direction and speed gradients for data from the met. mast Cariou, Rozenn Wagner, Julia Gottschall Title: Analysis of vertical wind direction and speed gradients.): The task of this project has been to study the vertical gradient of the wind direction from experimental

307

A Comparison of Vehicle Speed at Day and Night Rural Horizontal Curves  

E-Print Network [OSTI]

This thesis documents the linear mixed model developed for vehicle speed along two-lane two-way rural horizontal curves in the outside lane. Speed data at each curve was collected at four points along the curve including the midpoint of the curve...

Quaium, Ridwan B.

2010-07-14T23:59:59.000Z

308

Department of Engineering Design Spring 2012 Super 8...High Speed Paper Roll Alignment Set-Up  

E-Print Network [OSTI]

Set-Up Overview High speed printing requires precise alignment. Printer engines are able to send paper through a system at speeds up to 550 ft/min. Within these systems, the paper may encounter a 90o turn bar that changes the direction of the paper. Operators within Xerox facilities must manually set up the turn bar

Demirel, Melik C.

309

Optimal Thrust Characteristics of a Synthetic Jet Actuator for Application in Low Speed  

E-Print Network [OSTI]

speed maneuvering or locomotion of small unmanned underwater vehicles (UUVs) [1], [2]. The of Underwater Vehicles Michael Krieg, Aravind Pitty, Mostafa Salehi, and Kamran Mohseni Department of Aerospace actuators are pro- posed for low speed maneuvering and station keeping of small underwater vehicles

Mohseni, Kamran

310

UNIVERSITY of CALIFORNIA INVESTIGATION OF HOW ANGLE OF ATTACK AFFECTS ROTOR SPEED  

E-Print Network [OSTI]

-pitch blades is tested in UCSC's wind tunnel. The turbine is used to test how varying the blade angle affects the turbine's rotational speed at different wind speeds. The data are used to determine how the blade angle 27 Appendix A Wind Turbine Data 29 Appendix B Converting Blade Pitch to Needle Angle 33 Appendix C

Belanger, David P.

311

Applied Acoustics 63 (2002), 1109-1124 Noise assessment in a high-speed train  

E-Print Network [OSTI]

Applied Acoustics 63 (2002), 1109-1124 1 Noise assessment in a high-speed train Etienne PARIZET recordings in various positions in a high-speed train have been used as stimuli in listening tests to noise outside train or inside cars, the perception of noise in trains has not been studied intensively

Paris-Sud XI, Université de

312

Interpolating wind speed normals from the sparse Dutch network to a high resolution  

E-Print Network [OSTI]

, we had potential wind speed time series with 30 years of data (with at least 20 yearly and monthly by Verkaik (Verkaik, 2001). The method is a five-step procedure: 1 Use series of (potential) wind to calculate (potential) normals at measuring sites 2 Calculate wind speed normals at the top of the surface

Stoffelen, Ad

313

Robust STATCOM control for the stabilisation of fixed-speed wind turbines during low voltages  

E-Print Network [OSTI]

and rotor- speed instability and more so if the wind turbine is connected to a weak grid. To prevent is still being produced by squirrel-cage induction generators (SCIGs) which are directly connected to the grid and operate at an almost fixed-speed [3]. They are advantageous as wind generators for their low

Pota, Himanshu Roy

314

AN EXAMINATION OF BICYCLE COUNTS AND SPEEDS ASSOCIATED WITH THE INSTALLATION OF BIKE LANES  

E-Print Network [OSTI]

AN EXAMINATION OF BICYCLE COUNTS AND SPEEDS ASSOCIATED WITH THE INSTALLATION OF BIKE LANES IN ST An Examination of Bicycle Counts and Speeds Associated with the Installation of Bike Lanes in St. Petersburg It is assumed that installation of bicycle facilities will result in an increase in the number of bicyclists

North Carolina at Chapel Hill, University of

315

NEW OPTIMAL HIGH EFFICIENCY DSP-BASED DIGITAL CONTROLLER DESIGN FOR SUPER HIGH-SPEED PERMANENT  

E-Print Network [OSTI]

magnet synchronous motors (PMSM). The PMSMs are a key component for the miniaturic cryocooler of a super high-speed PMSM is an important issue particularly for open-loop control, given that PMSM-speed PMSM is analyzed and some design suggestions are given to maximize this parameter. For ordinary motors

Wu, Thomas

316

Probability distributions for offshore wind speeds Eugene C. Morgan a,*, Matthew Lackner b  

E-Print Network [OSTI]

Probability distributions for offshore wind speeds Eugene C. Morgan a,*, Matthew Lackner b Wind turbine energy output Weibull distribution Extreme wind a b s t r a c t In planning offshore wind farms, short-term wind speeds play a central role in estimating various engi- neering parameters

Vogel, Richard M.

317

Mining Markov chain transition matrix from wind speed time series data Zhe Song a,  

E-Print Network [OSTI]

). Knowing how wind behaves at specific wind farms is extremely important for today's power systems in termsMining Markov chain transition matrix from wind speed time series data Zhe Song a, , Xiulin Geng Wind speed time series Wind power Evolutionary algorithms Markov chain Optimization a b s t r a c

Kusiak, Andrew

318

High-speed and high-fidelity system and method for collecting network traffic  

DOE Patents [OSTI]

A system is provided for the high-speed and high-fidelity collection of network traffic. The system can collect traffic at gigabit-per-second (Gbps) speeds, scale to terabit-per-second (Tbps) speeds, and support additional functions such as real-time network intrusion detection. The present system uses a dedicated operating system for traffic collection to maximize efficiency, scalability, and performance. A scalable infrastructure and apparatus for the present system is provided by splitting the work performed on one host onto multiple hosts. The present system simultaneously addresses the issues of scalability, performance, cost, and adaptability with respect to network monitoring, collection, and other network tasks. In addition to high-speed and high-fidelity network collection, the present system provides a flexible infrastructure to perform virtually any function at high speeds such as real-time network intrusion detection and wide-area network emulation for research purposes.

Weigle, Eric H. (Los Alamos, NM)

2010-08-24T23:59:59.000Z

319

Method and apparatus for high speed data acquisition and processing  

DOE Patents [OSTI]

A method and apparatus are disclosed for high speed digital data acquisition. The apparatus includes one or more multiplexers for receiving multiple channels of digital data at a low data rate and asserting a multiplexed data stream at a high data rate, and one or more FIFO memories for receiving data from the multiplexers and asserting the data to a real time processor. Preferably, the invention includes two multiplexers, two FIFO memories, and a 64-bit bus connecting the FIFO memories with the processor. Each multiplexer receives four channels of 14-bit digital data at a rate of up to 5 MHz per channel, and outputs a data stream to one of the FIFO memories at a rate of 20 MHz. The FIFO memories assert output data in parallel to the 64-bit bus, thus transferring 14-bit data values to the processor at a combined rate of 40 MHz. The real time processor is preferably a floating-point processor which processes 32-bit floating-point words. A set of mask bits is prestored in each 32-bit storage location of the processor memory into which a 14-bit data value is to be written. After data transfer from the FIFO memories, mask bits are concatenated with each stored 14-bit data value to define a valid 32-bit floating-point word. Preferably, a user can select any of several modes for starting and stopping direct memory transfers of data from the FIFO memories to memory within the real time processor, by setting the content of a control and status register. 15 figs.

Ferron, J.R.

1997-02-11T23:59:59.000Z

320

Quantum noise of non-ideal Sagnac speed meter interferometer with asymmetries  

E-Print Network [OSTI]

The speed meter concept has been identified as a technique that can potentially provide laser-interferometric measurements at a sensitivity level which surpasses the Standard Quantum Limit (SQL) over a broad frequency range. As with other sub-SQL measurement techniques, losses play a central role in speed meter interferometers and they ultimately determine the quantum noise limited sensitivity that can be achieved. So far in the literature, the quantum noise limited sensitivity has only been derived for lossless or lossy cases using certain approximations (for instance that the arm cavity round trip loss is small compared to the arm cavity mirror transmission). In this article we present a generalised, analytical treatment of losses in speed meters that allows accurate calculation of the quantum noise limited sensitivity of Sagnac speed meters with arm cavities. In addition, our analysis allows us to take into account potential imperfections in the interferometer such as an asymmetric beam splitter or differences of the reflectivities of the two arm cavity input mirrors. Finally,we use the examples of the proof-of-concept Sagnac speed meter currently under construction in Glasgow and a potential implementation of a Sagnac speed meter in the Einstein Telescope (ET) to illustrate how our findings affect Sagnac speed meters with meter- and kilometre-long baselines.

S. L. Danilishin; C. Graef; S. S. Leavey; J. Hennig; E. A. Houston; D. Pascucci; S. Steinlechner; J. Wright; S. Hild

2014-12-02T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

A Test to Verify the Speed Change of Light in the Gravitational Field of the Earth  

E-Print Network [OSTI]

Based on the Schwarzschild solution of the Einstein equation of gravitational field, it is proved that the speed of light speed would change and isotropy of light speed would be violated in gravitational field with spherical symmetry. On the surface of the earth, the speed of light vertical to the surface is 0.2m/s less than that parallel to the surface. It is suggested to use the method of the Michelson Morley interference to verify the change of light speed and the violation of isotropy in the gravitational field of the earth. In the proposed experiment, one arm of interferometer is vertical to the earth surface while another is parallel to the surface. When two arms are turned over 90 degree, the shift of about 0.07 interference stripe would be caused which can be observed directly. So this experiment can be considered as a new verification for general relativity in the gravitational field with spherical symmetry. If the experiment shows that gravitation would change the speed of light and violate the isotropy of light speed, the result would cause great effects on foundational physics, astrophysics and cosmolo

Mei Xiaochun

2006-12-03T23:59:59.000Z

322

Generic vehicle speed models based on traffic simulation: Development and application  

SciTech Connect (OSTI)

This paper summarizes the findings of a research project to develop new methods of estimating speeds for inclusion in the Highway Performance Monitoring System (HPMS) Analytical Process. The paper focuses on the effects of traffic conditions excluding incidents (recurring congestion) on daily average ed and excess fuel consumption. A review of the literature revealed that many techniques have been used to predict speeds as a function of congestion but most fail to address the effects of queuing. However, the method of Dowling and Skabardonis avoids this limitation and was adapted to the research. The methodology used the FRESIM and NETSIM microscopic traffic simulation models to develop uncongested speed functions and as a calibration base for the congested flow functions. The chief contributions of the new speed models are the simplicity of application and their explicit accounting for the effects of queuing. Specific enhancements include: (1) the inclusion of a queue discharge rate for freeways; (2) use of newly defined uncongested flow speed functions; (3) use of generic temporal distributions that account for peak spreading; and (4) a final model form that allows incorporation of other factors that influence speed, such as grades and curves. The main limitation of the new speed models is the fact that they are based on simulation results and not on field observations. They also do not account for the effect of incidents on speed. While appropriate for estimating average national conditions, the use of fixed temporal distributions may not be suitable for analyzing specific facilities, depending on observed traffic patterns. Finally, it is recommended that these and all future speed models be validated against field data where incidents can be adequately identified in the data.

Margiotta, R.; Cohen, H.; Elkins, G.; Rathi, A.; Venigalla, M.

1994-12-15T23:59:59.000Z

323

Correlation of flame speed with stretch in turbulent premixed methane/air flames  

SciTech Connect (OSTI)

In the flamelet approach of turbulent premixed combustion, the flames are modeled as a wrinkled surface whose propagation speed, termed the {open_quotes}displacement speed,{close_quotes} is prescribed in terms of the local flow field and flame geometry. Theoretical studies suggest a linear relation between the flame speed and stretch for small values of stretch, S{sub L}/S{sub L}{sup 0} = 1 - MaKa, where S{sub L}{sup 0} is the laminar flame speed, Ka = {kappa}{delta}{sub F}/S{sub L}{sup 0} is the nondimensional stretch or the Karlovitz number, and Ma = L/{delta}{sub F} is the Markstein number. The nominal flame thickness, {delta}{sub F}, is determined as the ratio of the mass diffusivity of the unburnt mixture to the laminar flame speed. Thus, the turbulent flame model relies on an accurate estimate of the Markstein number in specific flame configurations. Experimental measurement of flame speed and stretch in turbulent flames, however, is extremely difficult. As a result, measurement of flame speeds under strained flow fields has been made in simpler geometries, in which the effect of flame curvature is often omitted. In this study we present results of direct numerical simulations of unsteady turbulent flames with detailed methane/air chemistry, thereby providing an alternative method of obtaining flame structure and propagation statistics. The objective is to determine the correlation between the displacement speed and stretch over a broad range of Karlovitz numbers. The observed response of the displacement speed is then interpreted in terms of local tangential strain rate and curvature effects. 13 refs., 3 figs.

Chen, J.H.; Im, Hong G.

1997-11-01T23:59:59.000Z

324

Detecting and Blocking Network Attacks at Ultra High Speeds  

SciTech Connect (OSTI)

Stateful, in-depth, in-line traffic analysis for intrusion detection and prevention has grown increasingly more difficult as the data rates of modern networks rise. One point in the design space for high-performance network analysis - pursued by a number of commercial products - is the use of sophisticated custom hardware. For very high-speed processing, such systems often cast the entire analysis process in ASICs. This project pursued a different architectural approach, which we term Shunting. Shunting marries a conceptually quite simple hardware device with an Intrusion Prevention System (IPS) running on commodity PC hardware. The overall design goal is was to keep the hardware both cheap and readily scalable to future higher speeds, yet also retain the unparalleled flexibility that running the main IPS analysis in a full general-computing environment provides. The Shunting architecture we developed uses a simple in-line hardware element that maintains several large state tables indexed by packet header fields, including IP/TCP flags, source and destination IP addresses, and connection tuples. The tables yield decision values the element makes on a packet-by-packet basis: forward the packet, drop it, or divert ('shunt') it through the IPS (the default). By manipulating table entries, the IPS can, on a fine-grained basis: (i) specify the traffic it wishes to examine, (ii) directly block malicious traffic, and (iii) 'cut through' traffic streams once it has had an opportunity to 'vet' them, or (iv) skip over large items within a stream before proceeding to further analyze it. For the Shunting architecture to yield benefits, it needs to operate in an environment for which the monitored network traffic has the property that - after proper vetting - much of it can be safely skipped. This property does not universally hold. For example, if a bank needs to examine all Web traffic involving its servers for regulatory compliance, then a monitor in front of one of the bank's server farms cannot safely omit a subset of the traffic from analysis. In this environment, Shunting cannot realize its main performance benefits, and the monitoring task likely calls for using custom hardware instead. However, in many other environments we find Shunting holds promise for delivering major performance gains. This arises due to the the widely documented 'heavy tail' nature of most forms of network traffic, which we might express as 'a few of the connections carry just about all the bytes.' The key additional insight is '... and very often for these few large connections, the very beginning of the connection contains nearly all the information of interest from a security analysis perspective.' We argue that this second claim holds because it is at the beginning of connections that authentication exchanges occur, data or file names and types are specified, request and reply status codes conveyed, and encryption is negotiated. Once these occur, we have seen most of the interesting facets of the dialog. Certainly the remainder of the connection might also yield some grist for analysis, but this is generally less likely, and thus if we want to lower analysis load at as small a loss as possible of information relevant to security analysis, we might best do so by skipping the bulk of large connections. In a different context, the 'Time Machine' work by Kornexl and colleagues likewise shows that in some environments we can realize major reductions in the volume of network traffic processed, by limiting the processing to the first 10-20 KB of each connection. As a concrete example, consider an IPS that monitors SSH traffic. When a new SSH connection arrives and the Shunt fails to find an entry for it in any of its tables (per-address, per-port, per-connection), it executes the default action of diverting the connection through the IPS. The IPS analyzes the beginning of the connection in this fashion. As long as it is satisified with the dialog, it reinjects the packets forwarded to it so that the connection can continue. If the connection successfully

Paxson, Vern

2010-11-29T23:59:59.000Z

325

Environment assisted speed-up of the field evolution in cavity QED  

E-Print Network [OSTI]

We measure the quantum speed of the state evolution of the field in a weakly-driven optical cavity QED system. To this end, the mode of the electromagnetic field is considered as a quantum system of interest with a preferential coupling to a tunable environment: the atoms. By controlling the environment, i.e., changing the number of atoms coupled to the optical cavity mode, an environment assisted speed-up is realized: the quantum speed of the state re-population in the optical cavity increases with the coupling strength between the optical cavity mode and this non-Markovian environment (the number of atoms).

A. D. Cimmarusti; Z. Yan; B. D. Patterson; L. P. Corcos; L. A. Orozco; S. Deffner

2015-03-09T23:59:59.000Z

326

Effect of wind speed on the growth of the upper convective zone in a solar pond  

E-Print Network [OSTI]

LIST OF FIGURES CHAPTER Page 111 Vi I INTRODUCTION LITERATURE REVIEW III EXPERIMENTAL APPARATUS IV RESULTS 14 21 V ENTRAINMENT AS A FUNCTION OF RICHARDSON NUMBER 32 VI CONCLUSIONS AND RECOMMENDATIONS 44 REFERENCES APPENDIX 1 APPENDIX 2... speed. 11. Thickness of UCZ for 9. 6 m/s wind speed. 12. Thickness of UCZ for 15. 0 m/s wind speed. 52 53 54 55 56 57 58 13. Horizontal and vertical coordinates of 25 locations for measuring cross section air velocities. . . . . . 59 14. Air...

McMinn, Steven Lee

2012-06-07T23:59:59.000Z

327

Plastification of polymers in twin-screw-extruders: New visualization technic using high-speed imaging  

SciTech Connect (OSTI)

The initial melting of the first granules through plastic energy dissipation (PED) at the beginning of the melting zone, in the co-rotating twin-screw extruder is visualized in this work. The visualization was created through the use of a high speed camera in the cross section of the melting zone. The parameters screw speed, granule-temperature, temperature-profile, type of polymer and back pressure were examined. It was shown that the screw speed and the temperature-profile have significant influence on the rate of initial melting.

Knieper, A., E-mail: Alexander.Knieper@lbf.fraunhofer.de, E-mail: Christian.Beinert@lbf.fraunhofer.de; Beinert, C., E-mail: Alexander.Knieper@lbf.fraunhofer.de, E-mail: Christian.Beinert@lbf.fraunhofer.de [Group Polymer Processing, Division Plastics, Fraunhofer-Institute LBF (Germany)

2014-05-15T23:59:59.000Z

328

Effect of Inhomogeneity and Unsteadiness on the Stability of High-Speed Shear Flows  

E-Print Network [OSTI]

. Experiments of high-speed mixing layers observed reduced production rates [13]. Computational studies of high-speed homogeneous shear flow performed by Sarkar [4] and Simone et Al. [5] conclude that compress- ibility has a stabilizing effect on the growth...] show that the present RDT code captures the results of Simone et. al [5] very precisely. Most significantly, Lavin et al. [10] compare RDT anisotropy evolution of steady high-speed homogeneous shear with the DNS data of Sarkar [4] leading to reassuring...

Bertsch, Rebecca Lynne

2014-07-09T23:59:59.000Z

329

Real-time implementation of a neural networks-based motor speed filter using a digital signal processor  

E-Print Network [OSTI]

numerous speed estimation methods have been reported in the literature for the control of an induction motor drive, it is the accuracy of the speed estimate and the response time of the filter that are the important parameters describing the speed filter...

Harihara, Parasuram Padmanabhan

2012-06-07T23:59:59.000Z

330

Determination of Thermal Diffusivities, Thermal Conductivities, and Sound Speeds of Room-Temperature Ionic Liquids by the Transient Grating Technique  

E-Print Network [OSTI]

Determination of Thermal Diffusivities, Thermal Conductivities, and Sound Speeds of Room. The experiments give thermal diffusivities from which thermal conductivities can be determined, sound speeds not only on the sound speed but also on the thermal diffusivity and acoustic damping of the RTILs

Reid, Scott A.

331

Mathematical and Computational Applications, Vol. 18, No. 3, pp. 408-420, 2013 MODELING AND CONTROL OF A VARIABLE SPEED  

E-Print Network [OSTI]

as variable speed variable pitch angle wind turbine due to its advantages in efficiency and the structure that is close to the ideal power curve where the energy efficiency is maximized below the nominal wind speed of 11 / and the power is limited to the nominal value above the nominal wind speed. Turbsim

Yanikoglu, Berrin

332

IMPROVED MICROWAVE REMOTE SENSING OF HURRICANE WIND SPEED AND RAIN RATES USING THE HURRICANE IMAGING RADIOMETER (HIRAD)  

E-Print Network [OSTI]

IMPROVED MICROWAVE REMOTE SENSING OF HURRICANE WIND SPEED AND RAIN RATES USING THE HURRICANE) that measures wind speed and rain rate along the ground track directly beneath the aircraft. This paper presents are presented, which illustrate wind speed and rain rate measurement spatial resolutions and swath coverage. 1

Ruf, Christopher

333

Introduction Modeling of large ocean waves Propagation speed Coherent wavetrains Near-shore wave dynamics Conclusions Tsunamis and ocean waves  

E-Print Network [OSTI]

Introduction Modeling of large ocean waves Propagation speed Coherent wavetrains Near-shore wave waves #12;Introduction Modeling of large ocean waves Propagation speed Coherent wavetrains NearMaster University Tsunamis and ocean waves #12;Introduction Modeling of large ocean waves Propagation speed Coherent

Craig, Walter

334

1. Wind-splash erosion 4. Relationships between rainfall intensity, wind-speed, wind direction and erosion  

E-Print Network [OSTI]

from the surface but unless it corresponds to a high wind-speed (the potential to transport a single rainfall event. When high wind-speeds and heavy rainfall combine there is an increased potential1. Wind-splash erosion 4. Relationships between rainfall intensity, wind-speed, wind direction

335

Motion control of high-speed hydrofoil vessels using state-space methods  

E-Print Network [OSTI]

Hydrofoil ships cruise at large speeds and are often expected to operate in rough weather conditions. The motion of these ships due to their encounter with ambient waves can become uncomfortable or even dangerous without ...

Chatzakis, Iason

2004-01-01T23:59:59.000Z

336

Design and assessment of a super high speed, hybrid hydrofoil/SWATH crew boat  

E-Print Network [OSTI]

This thesis presents the preliminary design and assessment of Wavecutter, an innovative super high speed, hybrid hydrofoil/SWATH crew boat. The intended mission of the vessel is the very-fast transportation of crew and ...

Georgiadis, Vasileios

2014-01-01T23:59:59.000Z

337

Design of a high speed planing hull with a cambered step and surface piercing hydrofoils  

E-Print Network [OSTI]

Design of a high speed planing hull is analyzed by implementing a cambered step and stem, surface piercing hydrofoils, commonly known as a Dynaplane hull. This configuration combines the drag reduction benefits of a stepped ...

Faison, Leon Alexander

2014-01-01T23:59:59.000Z

338

Low Wind Speed Turbine Development Project Report: November 4, 2002 - December 31, 2006  

SciTech Connect (OSTI)

This report summarizes work conducted by Clipper Windpower under the DOE Low Wind Speed Turbine project. The objective of this project was to produce a wind turbine that can lower the cost of energy.

Mikhail, A.

2009-01-01T23:59:59.000Z

339

aisi m2 high-speed: Topics by E-print Network  

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

occur. Although current ... SooHoo, Kimberly E 2008-01-01 44 High speed air pneumatic wind shield wiping design MIT - DSpace Summary: In this creative design process a number of...

340

Optimal motion planning with the half-car dynamical model for autonomous high-speed driving  

E-Print Network [OSTI]

We discuss an implementation of the RRT* optimal motion planning algorithm for the half-car dynamical model to enable autonomous high-speed driving. To develop fast solutions of the associated local steering problem, we ...

Jeon, Jeong hwan

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Comparison of day and night vehicular speeds on horizontal curves on rural two-lane highways  

E-Print Network [OSTI]

the magnitude of the difference between daytime and nighttime speeds is small for all degrees of curvature, a variable accounting for light condition is not needed for operating-speedbased profile modeling for horizontal alignment design consistency evaluation....

Guzman, Jesus

1996-01-01T23:59:59.000Z

342

Wind: wind speed and wind power density maps at 10m and 50m above...  

Open Energy Info (EERE)

files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikSCAT SeaWinds scatterometer....

343

Wind: wind speed and wind power density GIS data at 10m and 50m...  

Open Energy Info (EERE)

files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikScat SeaWinds scatterometer....

344

4D dynamic imaging of the eye using ultrahigh speed SS-OCT  

E-Print Network [OSTI]

Recent advances in swept-source / Fourier domain optical coherence tomography (SS-OCT) technology enable in vivo ultrahigh speed imaging, offering a promising technique for four-dimensional (4-D) imaging of the eye. Using ...

Grulkowski, Ireneusz

345

Influence of low-speed aerodynamic performance on airport community noise  

E-Print Network [OSTI]

Properly assessing proposed aviation policies requires a thorough trade study of noise, emissions, fuel consumption, and cost. Aircraft low-speed aerodynamic performance is an important driver of all these impacts, and ...

March, Andrew I. (Andrew Irving)

2008-01-01T23:59:59.000Z

346

Wind speed influence on phytoplankton bloom dynamics in the Southern Ocean Marginal Ice Zone  

E-Print Network [OSTI]

Niebauer, H. J. (1982), Wind and melt driven circulation inJ. K. Moore (2007), Wind speed influence on phytoplanktonby the NASA Ocean Vector Winds Science Team. Data are

Fitch, Dillon T; Moore, J. Keith

2007-01-01T23:59:59.000Z

347

E-Print Network 3.0 - annual wind speeds Sample Search Results  

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

Search Powered by Explorit Topic List Advanced Search Sample search results for: annual wind speeds Page: << < 1 2 3 4 5 > >> 1 This document will help you understand the...

348

Speed Training: Improving the Rate of Backpropagation Learning through Stochastic Sample Presentation  

E-Print Network [OSTI]

Speed Training: Improving the Rate of Backpropagation Learning through Stochastic Sample. However, using complex neural networks to learn very large training sets is often problematic, imposing prohibitive time constraints on the training process. We present four practical methods for dramatically

Martinez, Tony R.

349

Adjustable Speed Drives in the U.S. Petroleum Refining, Petrochemical, and Chemical Industries  

E-Print Network [OSTI]

This paper describes applications and incentives for the use of variable frequency drivers (VFD) in the petroleum refining, petrochemical, and chemical industries. VFDs are a particular type of adjustable speed driver (ASD) found prevalently...

Foley, D. J.; Chodorowski, A.

350

Variable Speed Drive (VSD) Applications in Dual-Duct Constant Volume Systems  

E-Print Network [OSTI]

Models have been developed for static pressure and potential supply fan energy savings by using variable speed drive (VSD) in dual-duct constant volume systems. Experiments have been performed using a full size dual-duct constant volume system...

Joo, I.; Liu, M.; Conger, K.; Wang, G.

2002-01-01T23:59:59.000Z

351

Measurement of sound speed vs. depth in South Pole ice: pressure waves and shear waves  

E-Print Network [OSTI]

Price, Attenuation of acoustic waves in glacial ice and saltacoustics, South Pole, sound speed, pressure waves,shear waves PACS: 47.35.De, 47.35.Rs, 62.65. +k, 92.40.Vq,

Klein, Spencer

2010-01-01T23:59:59.000Z

352

A lean enterprise approach for developing high speed rail in Japan and Portugal  

E-Print Network [OSTI]

This thesis explores and evaluates the application of the lean enterprise concept to the expansion and development of the high speed railway industry in Japan. The basic idea of the lean enterprise is increasing value-added ...

Iwamura, Nobuhiro

2007-01-01T23:59:59.000Z

353

Microwave determination of location and speed of an object inside a pipe  

DOE Patents [OSTI]

Apparatus and method are described for measuring the location and speed of an object, such as instrumentation on a movable platform, disposed within a pipe, using continuous-wave, amplitude-modulated microwave radiation.

Sinha, Dipen N. (Los Alamos, NM)

2010-12-14T23:59:59.000Z

354

Use of a speed equation for numerical simulation of hydraulic fractures  

E-Print Network [OSTI]

The paper treats the propagation of a hydraulically driven crack. We explicitly write the local speed equation, which facilitates using the theory of propagating interfaces. It is shown that when neglecting the lag between the liquid front and the crack tip, the lubrication PDE yields that a solution satisfies the speed equation identically. This implies that for zero or small lag, the boundary value problem appears ill-posed when solved numerically. We suggest e - regularization, which consists in employing the speed equation together with a prescribed BC on the front to obtain a new BC formulated at a small distance behind the front rather than on the front itself. It is shown that - regularization provides accurate and stable results with reasonable time expense. It is also shown that the speed equation gives a key to proper choice of unknown functions when solving a hydraulic fracture problem numerically.

Linkov, Alexander M

2011-01-01T23:59:59.000Z

355

Application of Multiple-Speed and Special Motors for Energy Savings  

E-Print Network [OSTI]

For the past several years substantial use has been made of a class of motors developed for application in driving loads which operate at multiple speed points to gain efficiency. While adjustable frequency power supplies may be more attractive...

Pastor, E.; Kuznetsov, S. B.

1982-01-01T23:59:59.000Z

356

Light-weight materials selection for high-speed naval craft  

E-Print Network [OSTI]

A decision analysis study was conducted on the process of materials selection for high-speed naval craft using the Modified Digital Logic (MDL) method proposed by B. Dehgham-Manshadi et al in ref [17]. The purpose is to ...

Torrez, Joseph B. (Joseph Benjamin)

2007-01-01T23:59:59.000Z

357

High Speed Pumps Are No Longer Limited to Low Flow Applications  

E-Print Network [OSTI]

Historically, the high-speed centrifugal pump was developed prior to World War II for rocket engine fuel pump applications for its advantages of light weight, compactness and dry running capability. Industrial derivatives were introduced in the 60s...

Burke, P. Y.

358

E-Print Network 3.0 - at-speed interconnect bist Sample Search...  

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

Explorit Topic List Advanced Search Sample search results for: at-speed interconnect bist Page: << < 1 2 3 4 5 > >> 1 JOURNAL OF ELECTRONIC TESTING: Theory and Applications 19,...

359

Laser wakefield simulation using a speed-of-light frame envelope model  

E-Print Network [OSTI]

Laser wake?eld simulation using a speed-of-light frameAbstract. Simulation of laser wake?eld accelerator (LWFA)extend hundreds of laser wave- lengths transversely and many

Cowan, B.

2010-01-01T23:59:59.000Z

360

Wind speed forecasting at different time scales: a non parametric approach  

E-Print Network [OSTI]

The prediction of wind speed is one of the most important aspects when dealing with renewable energy. In this paper we show a new nonparametric model, based on semi-Markov chains, to predict wind speed. Particularly we use an indexed semi-Markov model, that reproduces accurately the statistical behavior of wind speed, to forecast wind speed one step ahead for different time scales and for very long time horizon maintaining the goodness of prediction. In order to check the main features of the model we show, as indicator of goodness, the root mean square error between real data and predicted ones and we compare our forecasting results with those of a persistence model.

D'Amico, Guglielmo; Prattico, Flavio

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

First and second order semi-Markov chains for wind speed modeling  

E-Print Network [OSTI]

The increasing interest in renewable energy, particularly in wind, has given rise to the necessity of accurate models for the generation of good synthetic wind speed data. Markov chains are often used with this purpose but better models are needed to reproduce the statistical properties of wind speed data. We downloaded a database, freely available from the web, in which are included wind speed data taken from L.S.I. -Lastem station (Italy) and sampled every 10 minutes. With the aim of reproducing the statistical properties of this data we propose the use of three semi-Markov models. We generate synthetic time series for wind speed by means of Monte Carlo simulations. The time lagged autocorrelation is then used to compare statistical properties of the proposed models with those of real data and also with a synthetic time series generated though a simple Markov chain.

D'Amico, Guglielmo; Prattico, Flavio

2012-01-01T23:59:59.000Z

362

The Use of Variable Speed Drives to Retrofit Hydraulic Injection Molding Machines  

E-Print Network [OSTI]

Research Institute, Palo Alto, California. 8.) Remley, Carl H. (1993) "Measured performance of variable speed drives on injection molding hydraulic pumps." Energy Management Consulting and Equipment, Inc., North Attleboro, Massachusetts'. 9.) Rosato...

Ambs, L.; Frerker, M. M.

363

Design of a high-speed, meso-scale nanopositioners driven by electromagnetic actuators  

E-Print Network [OSTI]

The purpose of this thesis is to generate the design and fabrication knowledge that is required to engineer high-speed, six-axis, meso-scale nanopositioners that are driven by electromagnetic actuators. When compared to ...

Golda, Dariusz, 1979-

2008-01-01T23:59:59.000Z

364

Press and Dryer Roll Surgaces and Web Transfer Systems for Ultra High Paper Maching Speeds  

SciTech Connect (OSTI)

The objective of the project was to provide fundamental knowledge and diagnostic tools needed to design new technologies that will allow ultra high speed web transfer from press rolls and dryer cylinders.

T. F. Patterson

2004-03-15T23:59:59.000Z

365

The development and utilization of a high-speed laboratory rock drilling apparatus  

E-Print Network [OSTI]

THE DEVELOPMENT AND UTILIZATION OF A HIGH-SPEED LABORATORY ROCK DRILLING APPARATUS A Thesis by JEFFREY DALE DAY Submitted to the Graduate College of Texas AGM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1988 Major Subject: Petroleum Engineering THE DEVELOPMENT AND UTILIZATION OF A HIGH-SPEED LABORATORY ROCK DRILLING APPARATUS A Thesis by JEFFREY DALE DAY Approved as to style and content by: Hans C. Juvkam-Wold (Chair of Committee...

Day, Jeffrey Dale

1988-01-01T23:59:59.000Z

366

Swimming speed and stamina in head started Kemp's ridley sea turtles (Lepidochelys Kempi)  

E-Print Network [OSTI]

SWIMMING SPEED AND STAMINA IN HEAD STARTED KEMP'S RIDLEY SEA TURTLES (LEPIDOCHELYS KEMPI) A Thesis by ERICH KURT STABENAU Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER QF SCIENCE August 1988 Major Subject: Wildlife and Fisheries Sciences SWIMMING SPEED AND STAMINA IN HEAD STARTED KEMP'S RIDLEY SEA TURTLES (LEPIDOCHELYS KEMPI) A Thesis by ERICH KURT STABENAU Approved as to style and content by: Andre M...

Stabenau, Erich Kurt

1988-01-01T23:59:59.000Z

367

Method and apparatus for reducing rotor blade deflections, loads, and/or peak rotational speed  

DOE Patents [OSTI]

A method for reducing at least one of loads, deflections of rotor blades, or peak rotational speed of a wind turbine includes storing recent historical pitch related data, wind related data, or both. The stored recent historical data is analyzed to determine at least one of whether rapid pitching is occurring or whether wind speed decreases are occurring. A minimum pitch, a pitch rate limit, or both are imposed on pitch angle controls of the rotor blades conditioned upon results of the analysis.

Moroz, Emilian Mieczyslaw; Pierce, Kirk Gee

2006-10-17T23:59:59.000Z

368

Comment on "Measurement of the speed-of-light perturbation of free-fall absolute gravimeters"  

E-Print Network [OSTI]

The paper (Rothleitner et al. 2014 Metrologia 51, L9) reports on the measurement of the speed-of-light perturbation in absolute gravimeters. The conclusion that the perturbation reaches only 2/3 of the commonly accepted value violates the fundamental limitation on the maximum speed of information transfer. The conclusion was deluded by unaccounted parasitic perturbations, some of which are obvious from the report.

Nagornyi, V D

2014-01-01T23:59:59.000Z

369

Ris0-M-2829 2 Extreme Values ofWind Speeds  

E-Print Network [OSTI]

Ris0-M-2829 2 Extreme Values ofWind Speeds overthe Great Belt Region N.O. Jensen and B. Nielsen Ris events 9 4 Extrapolation to the 50-year storm 11 5 Discussion of the 50-year wind 15 6 Crosswind extremes for extreme values of wind speeds. The data material was obtained from a 70-m mast on a small island, Sprog0

370

On the extraction of laminar flame speed and Markstein length from outwardly propagating spherical flames  

SciTech Connect (OSTI)

Large discrepancies among the laminar flame speeds and Markstein lengths of methane/air mixtures measured by different researchers using the same constant-pressure spherical flame method are observed. As an effort to reduce these discrepancies, one linear model (LM, the stretched flame speed changes linearly with the stretch rate) and two non-linear models (NM I and NM II, the stretched flame speed changes non-linearly with the stretch rate) for extracting the laminar flame speed and Markstein length from propagating spherical flames are investigated. The accuracy and performance of the LM, NM I, and NM II are found to strongly depend on the Lewis number. It is demonstrated that NM I is the most accurate for mixtures with large Lewis number (positive Markstein length) while NM II is the most accurate for mixtures with small Lewis number (negative Markstein length). Therefore, in order to get accurate laminar flame speed and Markstein length from spherical flame experiments, different non-linear models should be used for different mixtures. The validity of the theoretical results is further demonstrated by numerical and experimental studies. The results of this study can be used directly in spherical flame experiments measuring the laminar flame speed and Markstein length. (author)

Chen, Zheng [State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Aerospace Engineering, College of Engineering, Peking University, Beijing 100871 (China)

2011-02-15T23:59:59.000Z

371

Development of a super high speed motor-generator and controller  

SciTech Connect (OSTI)

To develop a super high speed motor-generator, it is essential to deal with magnetic analysis, dynamic analysis, and experimental evaluation of the heart of the MTG (Microturbine Generator) system, the motor-generator. An amorphous core is applied to a stator core for reduction of iron loss at high speed, and the motor-generator is analyzed with considerations focused on magnetic losses and the statistical optimum design. The performance of the amorphous core is validated by the analysis and experiment by back-to-back tests considering the AC load. Rotor dynamics is performed for dynamic stability at high speed using transient analysis orbit diagrams and compared with the experimental results. The simulation results of the generator are compared with the experiment. Also a super high speed controller of the MTG system is developed using a sensorless algorithm, power stack, gate driver, digital signal processing, analog circuit, and radiation heat design. Based on these results, a high speed motor-generator and controller are successfully developed.

Hong, Do-Kwan, E-mail: dkhong@keri.re.kr; Ahn, Min-Hyuk; Joo, Dae-Suk; Woo, Byung-Chul; Koo, Dae-Hyun [Korea Electrotechnology Research Institute, Changwon 641-120 (Korea, Republic of)

2014-05-07T23:59:59.000Z

372

Resonant Vibrations Resulting from the Re-Engineering of a Constant-Speed 2-Bladed Turbine to a Variable-Speed 3-Bladed Turbine  

SciTech Connect (OSTI)

The CART3 (Controls Advanced Research Turbine, 3-bladed) at the National Wind Technology Center has recently been converted from a 2-bladed constant speed machine to a 3-bladed variable speed machine designed specically for controls research. The purpose of this conversion was to develop an advanced controls field-testing platform which has the more typical 3-bladed configuration. A result of this conversion was the emergence of several resonant vibrations, some of which initially prevented operation of the turbine until they could be explained and resolved. In this paper, the investigations into these vibrations are presented as 'lessons-learned'. Additionally, a frequency-domain technique called waterfall plotting is discussed and its usefulness in this research is illustrated.

Fleming, P.; Wright, A. D.; Finersh, L. J.

2010-12-01T23:59:59.000Z

373

Systematic approach for PID controller design for pitch-regulated, variable-speed wind turbines  

SciTech Connect (OSTI)

Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three regions of operation. This paper focuses on controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative (PID) controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship of the two opposing metrics is easily visualized. 2 refs., 9 figs.

Hand, M.M. [National Renewable Energy Lab., Golden, CO (United States); Balas, M.J. [Univ. of Colorado, Boulder, CO (United States). Dept. of Aerospace Engineering Sciences

1997-11-01T23:59:59.000Z

374

System and method for motor speed estimation of an electric motor  

DOE Patents [OSTI]

A system and method for a motor management system includes a computer readable storage medium and a processing unit. The processing unit configured to determine a voltage value of a voltage input to an alternating current (AC) motor, determine a frequency value of at least one of a voltage input and a current input to the AC motor, determine a load value from the AC motor, and access a set of motor nameplate data, where the set of motor nameplate data includes a rated power, a rated speed, a rated frequency, and a rated voltage of the AC motor. The processing unit is also configured to estimate a motor speed based on the voltage value, the frequency value, the load value, and the set of nameplate data and also store the motor speed on the computer readable storage medium.

Lu, Bin (Kenosha, WI); Yan, Ting (Brookfield, WI); Luebke, Charles John (Sussex, WI); Sharma, Santosh Kumar (Viman Nagar, IN)

2012-06-19T23:59:59.000Z

375

SOUND-SPEED INVERSION OF THE SUN USING A NONLOCAL STATISTICAL CONVECTION THEORY  

SciTech Connect (OSTI)

Helioseismic inversions reveal a major discrepancy in sound speed between the Sun and the standard solar model just below the base of the solar convection zone. We demonstrate that this discrepancy is caused by the inherent shortcomings of the local mixing-length theory adopted in the standard solar model. Using a self-consistent nonlocal convection theory, we construct an envelope model of the Sun for sound-speed inversion. Our solar model has a very smooth transition from the convective envelope to the radiative interior, and the convective energy flux changes sign crossing the boundaries of the convection zone. It shows evident improvement over the standard solar model, with a significant reduction in the discrepancy in sound speed between the Sun and local convection models.

Zhang Chunguang; Deng Licai [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Xiong Darun [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Christensen-Dalsgaard, Jorgen, E-mail: cgzhang@nao.cas.cn [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark)

2012-11-01T23:59:59.000Z

376

Method for leveling the power output of an electromechanical battery as a function of speed  

DOE Patents [OSTI]

The invention is a method of leveling the power output of an electromechanical battery during its discharge, while at the same time maximizing its power output into a given load. The method employs the concept of series resonance, employing a capacitor the parameters of which are chosen optimally to achieve the desired near-flatness of power output over any chosen charged-discharged speed ratio. Capacitors are inserted in series with each phase of the windings to introduce capacitative reactances that act to compensate the inductive reactance of these windings. This compensating effect both increases the power that can be drawn from the generator before inductive voltage drops in the windings become dominant and acts to flatten the power output over a chosen speed range. The values of the capacitors are chosen so as to optimally flatten the output of the generator over the chosen speed range. 3 figs.

Post, R.F.

1999-03-16T23:59:59.000Z

377

Low Wind Speed Turbine Developments in Convoloid Gearing: Final Technical Report, June 2005 - October 2008  

SciTech Connect (OSTI)

This report presents the results of a study conducted by Genesis Partners LP as part of the United States Department of Energy Wind Energy Research Program to develop wind technology that will enable wind systems to compete in regions having low wind speeds. The purpose of the program is to reduce the cost of electricity from large wind systems in areas having Class 4 winds to 3 cents per kWh for onshore systems or 5 cents per kWh for offshore systems. This work builds upon previous activities under the WindPACT project, the Next Generation Turbine project, and Phase I of the Low Wind Speed Turbine (LWST) project. This project is concerned with the development of more cost-effective gearing for speed increasers for wind turbines.

Genesis Partners LP

2010-08-01T23:59:59.000Z

378

Improvement of speed control performance using PID type neurocontroller in an electric vehicle system  

SciTech Connect (OSTI)

In order to develop an efficient driving system for electric vehicle (EV), a testing system using motors has been built to simulate the driving performance of EVs. In the testing system, the PID (Proportional Integral Derivative) controller is used to control rotating speed of motor when the EV drives. In this paper, in order to improve the performance of speed control, a neural network is applied to tuning parameters of PID controller. It is shown, through experiments that a neural network can reduce output error effectively while the PID controller parameters are being tuned online. 6 refs.

Matsumura, S.; Omatu, S.; Higasa, H. [Shikoku Research Inst. Inc., Takamatsu (Japan)

1994-12-31T23:59:59.000Z

379

Fuzzy logic enhanced speed control of an indirect field-oriented induction machine drive  

SciTech Connect (OSTI)

Field orientation control (FOC) of induction machines has permitted fast transient response by decoupled torque and flux control. However, field orientation detuning caused by parameter variations is a major difficulty for indirect FOC methods. Traditional probability density function (PID) controllers have trouble meeting a wide range of speed tracking performance even when proper field orientation is achieved. PID controller performance is severely degraded when detuning occurs. This paper presents a fuzzy logic design approach that can meet the speed tracking requirements even when detuning occurs. Computer simulations and experimental results obtained via a general-purpose digital signal processor (DSP) system are presented.

Heber, B.; Xu, L.; Tang, Y. [Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering] [Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering

1997-09-01T23:59:59.000Z

380

A study of wind-speed maxima near the surface over the south central United States  

E-Print Network [OSTI]

-1960) and the Oklahoma City radiosonde station data for the time period June, 1966 to May, 1967. They also showed that the higher the monthly, mean, wind speed, the more likely that the wind direction was from the south. Bonner (1968) states, "Strong early morning...) (Member) (Member) May 1973 ABSTRACT A Study of Wind-Speed Maxima near the Surface over the South Central United States (May 1973) Samuel K. Beckman, B. S. , Kansas State University Directed by: Professor Walter K. Henry Radiosonde and rawinsonde...

Beckman, Samuel Karl

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

On the relationship between temperature and wind speed in the atmospheric surface layer  

E-Print Network [OSTI]

LIBRAR& A AN m os??E " "" ON THE RELATIONSHIP BETWEEN T" MP. "RATURE AND WIND SPEED IN THE ATMOSPHERIC SURFACE LAYER A Thesis John Me Pierrard Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial... logarithmically with height+ Also, the choice of a method of determination of the roughness length must be governed by an awareness of possible errors in the wind speed meas- urementso The system used to collect the data employed in this study is susceptible...

Pierrard, John Martin

2012-06-07T23:59:59.000Z

382

Enhancement of switching speed by laser-induced clustering of nanoparticles in magnetic fluids  

SciTech Connect (OSTI)

The switching speed of magnetic fluids was investigated by using laser light of different power densities as well as incandescent light. It was found that the switching speed exhibited a strong dependence on incident power density and there existed an optimum value at which the fastest switching operation was achieved. In addition, it was revealed that the clustering of magnetic nanoparticles, which became resolved at large power densities, resulted in a rapid agglomeration of nanoparticles when a magnetic field was applied. It is suggested that the optical trapping force of the laser beam is responsible for the formation of clusters.

Deng Haidong [Laboratory of Photonic Information Technology, School for Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou, Guangdong 510006 (China); College of Science, South China Agricultural University, Guangzhou, Guangdong 510642 (China); Liu Jin; Lin Xusheng; Sun Ting; Dai Qiaofeng; Wu Lijun; Lan Sheng [Laboratory of Photonic Information Technology, School for Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou, Guangdong 510006 (China); Zhao Weiren; Zhang Wei [College of Science and Technology Engineering, Guangdong University of Technology, Guangzhou, Guangdong 510006 (China); Gopal, Achanta Venu [DCMP and MS, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)

2008-06-09T23:59:59.000Z

383

Advanced Detector Research - Fabrication and Testing of 3D Active-Edge Silicon Sensors: High Speed, High Yield  

SciTech Connect (OSTI)

Development of 3D silicon radiation sensors employing electrodes fabricated perpendicular to the sensor surfaces to improve fabrication yields and increasing pulse speeds.

Parker, Sherwood I

2008-09-01T23:59:59.000Z

384

The Solar Wind Helium Abundance: Variation with Wind Speed and the Solar Cycle  

E-Print Network [OSTI]

The Solar Wind Helium Abundance: Variation with Wind Speed and the Solar Cycle Matthias R. Aellig Alamos National Lab., Los Alamos, NM 87545 Abstract We investigate the helium abundance in the solar wind of 1994 and early 2000 are analyzed. In agreement with similar work for previous solar cycles, we find

Richardson, John

385

The Evolution Towards Grids: Ten Years of High-Speed, Wide Area, Data Intensive Computing  

E-Print Network [OSTI]

systems (e.g., multi-component turbomachine simulation); · Management of very large parameter space / Boeing Remote Help Desk that will provide aircraft field maintenance personnel use of coupled video1 The Evolution Towards Grids: Ten Years of High-Speed, Wide Area, Data Intensive Computing William

386

Tuesday, 31 July, 2012 Rapid radiation belt losses occurring during high speed solar wind stream1  

E-Print Network [OSTI]

Tuesday, 31 July, 2012 1 Rapid radiation belt losses occurring during high speed solar wind stream1 Raita11 Sodankylä Geophysical Observatory, University of Oulu, Sodankylä, Finland12 Abstract. Recent geomagnetic disturbances triggered by the arrival of a Solar14 Wind Stream Interface (SWSI). In the current

Otago, University of

387

International Journal of High Speed Electronics and Systems World Scientific Publishing Company  

E-Print Network [OSTI]

of intense interest for basic and applied research. Carbon nanotubes are sheets of graphene (a semiInternational Journal of High Speed Electronics and Systems © World Scientific Publishing Company CARBON NANOTUBE FIELD-EFFECT TRANSISTORS JING GUO*, SIYURANGA O. KOSWATTA, NEOPHYTOS NEOPHYTOU, AND MARK

388

Self-excited induction generator for variable-speed wind turbine generation  

SciTech Connect (OSTI)

When an induction generator is connected to a utility bus, the voltage and frequency at the terminal of the generator are the same as the voltage and frequency of the utility. The reactive power needed by the induction generator is supplied by the utility and the real power is returned to the utility. The rotor speed varies within a very limited range, and the reactive power requirement must be transported through a long line feeder, thus creating additional transmission losses. The energy captured by a wind turbine can be increased if the rotor speed can be adjusted to follow wind speed variations. For small applications such as battery charging or water pumping, a stand alone operation can be implemented without the need to maintain the output frequency output of the generator. A self- excited induction generator is a good candidate for a stand alone operation where the wind turbine is operated at variable speed. Thus the performance of the wind turbine can be unproved. In this paper, we examine a self-excited induction generator operated in a stand alone mode. A potential application for battery charging is given. The output power of the generator will be controlled to improve the performance of the wind turbine.

Muljadi, E.; Gregory, B. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Broad, D. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Electrical Engineering] [Colorado State Univ., Fort Collins, CO (United States). Dept. of Electrical Engineering

1996-10-01T23:59:59.000Z

389

High temperature measurement using very high shutter speed to avoid image saturation  

SciTech Connect (OSTI)

This paper explores the adaptation of the two-colour principle to develop a high-speed colour temperature correlation system, which is able to cover a range of temperature that is challenging to achieve before. A colour digital camera has built in RGB filters. It is possible to measure the temperature from the ratio of intensity of the green and red pixels using the two-colour principle based on the expansion of the Planks radiation law. In this study, experiments were carried out using a temperature calibrated tungsten ribbon lamp which can be tuned to vary from 1300 to 2200C. Using very high shutter speed and small aperture, the high-speed camera successfully captured the tungsten ribbon without image saturation at the full temperature scale. Tests have been carried out at different temperature and camera settings. The sensitivity and errors have been analysed, and experiment results demonstrate the potential of using very high shutter speed is available for measuring the temperature even beyond 2200C.

Ma, Zhen; Zhang, Yang [Department of Mechanical Engineering, Sir Frederick Mappin Building, University of Sheffield, Sheffield, S1 3JD (United Kingdom)

2014-04-11T23:59:59.000Z

390

Applications of adjustable speed drives. (Latest citations from the EI Compendex*plus database). Published Search  

SciTech Connect (OSTI)

The bibliography contains citations concerning types and applications of adjustable speed drives (ASD). Uses in heat pumps, fans, compressors, electric motors, boiler feed systems, and power transmission are described. Coverage includes AC-DC motors, induction motors, and brushless electric motors. Energy cost savings are also examined. (Contains a minimum of 102 citations and includes a subject term index and title list.)

Not Available

1994-06-01T23:59:59.000Z

391

Swimming speeds of filaments in nonlinearly viscoelastic fluids Henry C. Fu,1,a  

E-Print Network [OSTI]

the observed accelerations of these swimmers. At the limit of zero Reynolds number, the sum of the net drag of swimming at zero Reynolds numbers in a Newtonian fluid. For example, Taylor3 calculated the swimming speed these results to examine what types of swimming motions can produce net translation in a nonlinear fluid

Wolgemuth, Charles

392

The Impacts of Wind Speed Trends and Long-term Variability in Relation to Hydroelectric  

E-Print Network [OSTI]

The Impacts of Wind Speed Trends and Long- term Variability in Relation to Hydroelectric Reservoir and Long-term Variability in Relation to Hydroelectric Reservoir Inflows on Wind Power in the Pacific through diversification. In hydroelectric dominated systems, like the PNW, the benefits of wind power can

Kohfeld, Karen

393

MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES  

E-Print Network [OSTI]

MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND for conditions important for offshore wind energy utilisation are compared and tested: Four models tested with data from the offshore field measurement Rødsand by extrapolating the measured 10 m wind

Heinemann, Detlev

394

EVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES  

E-Print Network [OSTI]

EVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES important for offshore wind energy utilisation are discussed and tested: Four models for the surface tested with data from the offshore field measurement Rødsand by extrapolating the measured 10 m wind

Heinemann, Detlev

395

EVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES  

E-Print Network [OSTI]

EVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES important for offshore wind energy utilisation are discussed and tested: Four models for the surface tested with measurements from the offshore field measurement Rødsand by extrapolating the measured 10 m

Heinemann, Detlev

396

MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES  

E-Print Network [OSTI]

MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND important for offshore wind energy utilisation are discussed and tested: Four models for the surface tested with data from the offshore field measurement Rødsand by extrapolating the measured 10 m wind

Heinemann, Detlev

397

Holte, Mkadmi, Zimmer, MacDonald 1 AI Journal (Revised) Speeding Up Problem Solving by Abstraction  

E-Print Network [OSTI]

Holte, Mkadmi, Zimmer, MacDonald 1 AI Journal (Revised) Speeding Up Problem Solving by Abstraction, Uxbridge, England, UB8 3PH. Robert.Zimmer@brunel.ac.uk A.J. MacDonald Electrical Eng. Dept., Brunel to drive between two locations in a city or country. #12;Holte, Mkadmi, Zimmer, MacDonald 2 AI Journal

Holte, Robert

398

High-speed machining of cast iron and alloy steels for die and mold manufacturing  

E-Print Network [OSTI]

to machining of aluminum alloys for manufacturing complicated parts used in the aircraft industry. This tech of automotive and electronic components, as well as plastic molding parts [2]. The de®nition of high conventional in cut- ting aluminum. Major advantages of high-speed machining are reported as: high material

Ozel, Tugrul

399

Computer Based Motor Parameter Determination for High Speed Operation of Permanent Magnet Synchronous Machines  

E-Print Network [OSTI]

Synchronous Machines B. Szabados and U. Schaible McMaster University 1280 Main St. W., Hamilton, Ontario PM synchronous machine parameters in the high speed operating range. The theory and real interior PM synchronous machine at up to 8000 rpm. Results are presented which show a significant variation

Szabados, Barna

400

Medium-Speed Drivetrain Test Report: September 1, 2002 -- December 30, 2007  

SciTech Connect (OSTI)

This report describes the tests conducted by researchers at the National Wind Technology Center at NREL on a 1.5-MW integrated drivetrain consisting of a single-stage, epicyclic gearbox and close-coupled medium-speed permanent-magnet generator.

Walford, C.; Lybarger, K.; Lettenmaier, T.; Roberts, D.

2012-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Interior Duct Wall Pressure Downstream of a Low-Speed Scott C. Morris  

E-Print Network [OSTI]

Interior Duct Wall Pressure Downstream of a Low-Speed Rotor Scott C. Morris , David B. Stephens The region downstream of a ducted rotor has been experimentally investigated in terms of its wake the description of the flow field and wall pressure in the region downstream of the rotor. Measurements involving

Alonso, Juan J.

402

Development of Improved Traveler Survey Methods for High-Speed Intercity Passenger Rail Planning  

E-Print Network [OSTI]

High-speed passenger rail is seen by many in the U.S. transportation policy and planning communities as an ideal solution for fast, safe, and resource-efficient mobility in high-demand intercity corridors. To expand the body of knowledge for high...

Sperry, Benjamin

2012-07-16T23:59:59.000Z

403

CMOS/BiCMOS Optoelectronic Receiver High-Speed Circuits and Systems Lab 1  

E-Print Network [OSTI]

CMOS/BiCMOS Optoelectronic Receiver High-Speed Circuits and Systems Lab 1 Silicon-based optoelectronic Rx for optical interconnect applications Process Standard CMOS 0.13-m technology Data Up to 10-Gb Optoelectronic Receiver SiGe BiCMOS Optoelectronic Receiver Process Standard BiCMOS 0.25-m technology Data Up

Choi, Woo-Young

404

(INVITED PAPER) SiGe/Si-Based Optoelectronic Devices for High-Speed Communication Applications  

E-Print Network [OSTI]

(INVITED PAPER) SiGe/Si-Based Optoelectronic Devices for High-Speed Communication ApplicationsGe/Si-based optoelectronic devices are described. These include photodiodes, photoreceivers and modulators. In There is immense interest in the realization of Si-based optoelectronic devices, optoelectronic integrated circuits

Rieh, Jae-Sung

405

High-Speed and Low-Power PID Structures for Embedded Applications  

E-Print Network [OSTI]

High-Speed and Low-Power PID Structures for Embedded Applications Abdelkrim K. Oudjida1 , Nicolas-power finite-word-length PID controllers based on a new recursive multiplication algorithm. Compared scalable PID structures that can be tailored to the desired performance and power budget. All PIDs

Boyer, Edmond

406

Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid  

E-Print Network [OSTI]

Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault Wind Turbines with Induction Generator during Grid Fault by Sigrid M. Bolik Institute of Energy turbine technology has undergone rapid developments. Growth in size and the optimization of wind turbines

Hansen, René Rydhof

407

Individual Pitch Control for Mitigation of Power Fluctuation of Variable Speed Wind Turbines  

E-Print Network [OSTI]

Individual Pitch Control for Mitigation of Power Fluctuation of Variable Speed Wind Turbines, China mcheng@seu.edu.cn Abstract-- Grid connected wind turbines are the sources of power fluctuations presents an individual pitch control (IPC) strategy to mitigate the wind turbine power fluctuation at both

Hu, Weihao

408

Low speed control of a DC motor driving a mechanical system with fuzzy adaptive compensation  

E-Print Network [OSTI]

and lubricated sliding junctions. For experiments, an IBM PC, a DSPACE DSP board, SE uLM and Real Time Workshop are used. All three control systems can achieve such a very low sustainable speed as 0.005 rad/sec without stick-slip oscillations, which appear when...

Hyun, Dongyoon

1997-01-01T23:59:59.000Z

409

Copyright 2007 by ASME1 Laminar Flame Speeds and Strain Sensitivities of Mixtures of H2  

E-Print Network [OSTI]

to rich. [Keywords: Syngas, laminar flame speed, reactant preheat, CO2 dilution, N2 dilution] INTRODUCTION emissions. Synthetic gas (syngas) fuels derived from coal are particularly promising in this regard. Syngas, provides a significant barrier to syngas usage. Understanding the impact of this variability on combustor

Seitzman, Jerry M.

410

Steady Propagation Speed for Ram Accelerators1 Joseph M. Powers2  

E-Print Network [OSTI]

Steady Propagation Speed for Ram Accelerators1 Joseph M. Powers2 , Antonio C´ardenas3 , and Matthew. Such a geometry better represents the physical characteristics of exper- imental ram accelerators, in which projectiles have been accelerated to over 3000 m s . The model employs finite rate chemistry with simple one

411

SCALAR WIND SPEED AND DIRECTION TROPICAL CYCLONE RETRIEVALS FOR CONICAL SCANNING SCATTEROMETERS  

E-Print Network [OSTI]

SCALAR WIND SPEED AND DIRECTION TROPICAL CYCLONE RETRIEVALS FOR CONICAL SCANNING SCATTEROMETERS--Scatterometer measurements of ocean vector winds (OVW) are significantly degraded in the presence of the precipitation, especially in tropical cyclones. This paper presents a new ocean hurricane/typhoon wind vector retrieval

Hennon, Christopher C.

412

High-Speed Link Modeling: Analog/Digital Equalization and Modulation Techniques  

E-Print Network [OSTI]

High-speed serial input-output (I/O) link has required advanced equalization and modulation techniques to mitigate inter-symbol interference (ISI) caused by multi-Gb/s signaling over band-limited channels. Increasing demands for transceiver power...

Lee, Keytaek

2012-07-16T23:59:59.000Z

413

On the HighSpeed VLSI Implementation of ErrorsandErasures Correcting ReedSolomon Decoders  

E-Print Network [OSTI]

implementation for errors- alone Reed-Solomon decoding. In this paper, we apply the same methodology to transformOn the High­Speed VLSI Implementation of Errors­and­Erasures Correcting Reed­Solomon Decoders Tong of throughput. 1. INTRODUCTION Reed-Solomon (RS) codes are widely used for forward er- ror correcting (FEC

Zhang, Tong

414

Speeding up disease extinction with a limited amount of vaccine M. Khasin,1  

E-Print Network [OSTI]

studied in stochastic population dynamics. Spontaneous extinction of species is important alsoSpeeding up disease extinction with a limited amount of vaccine M. Khasin,1 M. I. Dykman,1 and B stable; disease extinction happens at random and requires a large fluctuation, which can come from

Dykman, Mark

415

High-speed Router Filter for Blocking TCP Flooding under DDoS Attack  

E-Print Network [OSTI]

High-speed Router Filter for Blocking TCP Flooding under DDoS Attack Yoohwan Kim',Ju-Yeon Jo', H during the Distributed Denial-oJService (DDoS) attack. By allocating bandwidths separately for TCP.9% of the attack trafic while legitimate traflc showed nearly identical performance as in the non-attacked

Chao, Jonathan

416

High-Speed Router Filter for Blocking TCP Flooding under DDoS Attack  

E-Print Network [OSTI]

1 High-Speed Router Filter for Blocking TCP Flooding under DDoS Attack Yoohwan Kim1 , Ju-Yeon Jo1 Polytechnic University, Brooklyn, NY 11201 ABSTRACT Protection from Distributed Denial-of-Service attacks has been of a great interest recently and substantial progress has been made for preventing some attack

Merat, Francis L.

417

Internal Friction Controls the Speed of Protein Folding from a Compact Configuration  

E-Print Network [OSTI]

Internal Friction Controls the Speed of Protein Folding from a Compact Configuration Suzette A is independent of the cosolutes used to adjust solvent friction. Therefore, interactions within the interior. Interestingly, we find a very strong temperature dependence in these "internal friction"-controlled dynamics

Roder, Heinrich

418

Forecasting of wind speed using wavelets analysis and cascade-correlation neural networks  

E-Print Network [OSTI]

for the city of Perpignan (south of France). In this sense, forecasting average wind speeds was the main such as sunlight, wind, rain or geothermal heat. Wind energy is actually one of the fastest-growing forms of electricity generation because wind is a clean, indigenous and inexhaustible energy resource that can generate

Paris-Sud XI, Université de

419

The fuel cell vehicle's But solutions to America's thirst for speed,  

E-Print Network [OSTI]

The fuel cell vehicle's But solutions to America's thirst for speed, power, and electrical gadgetry more expensive than that produced by fossil fuel-powered plants. And while conservation has reduced our that fuel cell vehicles (FCVs) cars that generate electricity from fuel cells can serve a dual role

Kammen, Daniel M.

420

Prediction Aggregation of Remote Traffic Microwave Sensors Speed and Volume Data  

E-Print Network [OSTI]

Prediction Aggregation of Remote Traffic Microwave Sensors Speed and Volume Data John R. Junger prediction is an important component of well developed Intelligent Trans- portation Systems and Advanced significant challenges to integrating polled data into such a predictive system. To overcome these, we present

Havlicek, Joebob

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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

Theoretical Estimates of HVAC Duct Channel Capacity for High-Speed Internet Access  

E-Print Network [OSTI]

Theoretical Estimates of HVAC Duct Channel Capacity for High-Speed Internet Access Ariton E. Xhafa-conditioning (HVAC) ducts based on multi-carrier transmission that uses M-QAM mod- ulation and measured channel- flections in HVAC ducts). Our work also shows that data rates in excess of 300 Mbps are possible over

Stancil, Daniel D.

422

An Area Efficien Low Power High Speed S-Box Implementation Using Power-Gated PLA  

E-Print Network [OSTI]

An Area Efficien Low Power High Speed S-Box Implementation Using Power-Gated PLA Ho Joon Lee- sign of Rijndael S-Box for the SubByte transformation using power-gating and PLA design techniques arrays,VLSI General Terms Cryptography, Power Gate, Low Power Keywords AES, PLA, Power Gate, S-Box 1

Ayers, Joseph

423

World Network Speed Record Shattered Caltech, SLAC, Fermilab, CERN, Michigan, Florida,  

E-Print Network [OSTI]

World Network Speed Record Shattered Caltech, SLAC, Fermilab, CERN, Michigan, Florida, Brookhaven, the Stanford Linear Accelerator Center (SLAC), Fermilab, CERN, and the University of Michigan and partners and Fermilab and an optimized Linux kernel developed at Michigan. Professor Harvey Newman of Caltech, head

Low, Steven H.

424

Polystyrene PS648 outlet optical birefringence pattern, piston speed 1.0mm/s  

E-Print Network [OSTI]

The optical birefringence pattern obtained from polystyrene PS648 flowing through a narrow slit. Experiment conducted on the Cambridge Multi Pass Rheometer (MPR4) at a piston speed of 1.0 mm/s at 170C. Video shows the outlet flow (from top to bottom)....

Hassell, David

2008-08-27T23:59:59.000Z

425

Polystyrene PS648 inlet optical birefringence pattern, piston speed 1.4mm/s  

E-Print Network [OSTI]

The optical birefringence pattern obtained from polystyrene PS648 flowing through a narrow slit. Experiment conducted on the Cambridge Multi Pass Rheometer (MPR4) at a piston speed of 1.4 mm/s at 170C. Video shows the inlet flow (from bottom to top)....

Hassell, David

2008-08-27T23:59:59.000Z

426

Polystyrene PS648 inlet optical birefringence pattern, piston speed 1.0mm/s  

E-Print Network [OSTI]

The optical birefringence pattern obtained from polystyrene PS648 flowing through a narrow slit. Experiment conducted on the Cambridge Multi Pass Rheometer (MPR4) at a piston speed of 1.0 mm/s at 170C. Video shows the inlet flow (from bottom to top)....

Hassell, David

2008-08-27T23:59:59.000Z

427

Polystyrene PS648 outlet optical birefringence pattern, piston speed 1.4mm/s  

E-Print Network [OSTI]

The optical birefringence pattern obtained from polystyrene PS648 flowing through a narrow slit. Experiment conducted on the Cambridge Multi Pass Rheometer (MPR4) at a piston speed of 1.4 mm/s at 170C. Video shows the outlet flow (from top to bottom)....

Hassell, David

2008-08-27T23:59:59.000Z

428

Polystyrene PS648 outlet optical birefringence pattern, piston speed 0.16mm/s  

E-Print Network [OSTI]

The optical birefringence pattern obtained from polystyrene PS648 flowing through a narrow slit. Experiment conducted on the Cambridge Multi Pass Rheometer (MPR4) at a piston speed of 0.16 mm/s at 170C. Video shows the outlet flow (from top...

Hassell, David

2008-08-27T23:59:59.000Z

429

Polystyrene PS648 inlet optical birefringence pattern, piston speed 0.16mm/s  

E-Print Network [OSTI]

The optical birefringence pattern obtained from polystyrene PS648 flowing through a narrow slit. Experiment conducted on the Cambridge Multi Pass Rheometer (MPR4) at a piston speed of 0.16 mm/s at 170C. Video shows the inlet flow (from bottom to top)....

Hassell, David

2008-08-27T23:59:59.000Z

430

High Speed Max-Log-MAP Turbo SISO Decoder Implementation Using Branch Metric Normalization  

E-Print Network [OSTI]

High Speed Max-Log-MAP Turbo SISO Decoder Implementation Using Branch Metric Normalization J. H.Erdogan@ee.ed.ac.uk, Tughrul.Arslan@ee.ed.ac.uk Abstract The authors present a turbo soft-in soft-out (SISO) decoder based. The turbo decoder with the proposed technique has been synthesized to evaluate its power consumption

Arslan, Tughrul

431

The Effect of Rare Earth Elements, Temperature and Rolling Speed on the Microstructure Evolution of Magnesium  

E-Print Network [OSTI]

The Effect of Rare Earth Elements, Temperature and Rolling Speed on the Microstructure Evolution ·Rare earth elements are the current focus of study due to: Ability to weaken the rolling texture of Aluminum Abundance: 8th most abundant element in Earth's crust (2% by mass) ·These properties can serve

Barthelat, Francois

432

Correlation of flame speed with stretch in turbulent premixed methane/air flames  

SciTech Connect (OSTI)

Direct numerical simulations of two-dimensional unsteady premixed methane/air flames are performed to determine the correlation of flame speed with stretch over a wide range of curvatures and strain rates generated by intense two-dimensional turbulence. Lean and stoichiometric premixtures are considered with a detailed C{sub 1}-mechanism for methane oxidation. The computed correlation shows the existence of two distinct stable branches. It further shows that exceedingly large negative values of stretch can be obtained solely through curvature effects which give rise to an overall nonlinear correlation of the flame speed with stretch. Over a narrower stretch range, {minus}1 {le} Ka {le} 1, which includes 90% of the sample, the correlation is approximately linear, and hence, the asymptotic theory for stretch is practically applicable. Overall, one-third of the sample has negative stretch. In this linear range, the Markstein number associated with the positive branch is determined and is consistent with values obtained from comparable steady counterflow computations. In addition to this conventional positive branch, a negative branch is identified. This negative branch occurs when a flame cusp, with a center of curvature in the burnt gases, is subjected to intense compressive strain, resulting in a negative displacement speed. Negative flame speeds are also encountered for extensive tangential strain rates exceeding a Karlovitz number of unity, a value consistent with steady counterflow computations.

Chen, J.H.; Im, H.G.

1998-03-01T23:59:59.000Z

433

Impact of Inductor Placement on the Performance of Adjustable Speed Drives Under Input Voltage Unbalance and  

E-Print Network [OSTI]

Engineering Dr. Madison, WI 53706 #12;IEEE 2005 International Electric Machines and Drives Conference (IEMDC on the induction machine performance characteristics, but the presence of an LC filter in the drive's input2005-07 Impact of Inductor Placement on the Performance of Adjustable Speed Drives Under Input

Lipo, Thomas

434

Combining Task-and Data Parallelism to Speed up Protein Folding on a Desktop Grid Platform  

E-Print Network [OSTI]

Combining Task- and Data Parallelism to Speed up Protein Folding on a Desktop Grid Platform Is efficient protein folding possible with CHARMM on the United Devices MetaProcessor? B. Uk1 , M. Taufer1 parallelism and might not fit the needs for protein folding simulations with explicit water molecules. A short

Taufer, Michela

435

SOLAR-CYCLE VARIATION OF SOUND SPEED NEAR THE SOLAR SURFACE  

SciTech Connect (OSTI)

We present evidence that the sound-speed variation with solar activity has a two-layer configuration, similar to the one observed below an active region, which consists of a negative layer near the solar surface and a positive one in the layer immediately below the first one. Frequency differences between the activity minimum and maximum of solar cycle 23, obtained applying global helioseismology to the Michelson Doppler Imager on board the Solar and Heliospheric Observatory, is used to determine the sound-speed variation from below the base of the convection zone to a few Mm below the solar surface. We find that the sound speed at solar maximum is smaller than at solar minimum at the limit of our determination (5.5 Mm). The min-to-max difference decreases in absolute values until {approx}7 Mm. At larger depths, the sound speed at solar maximum is larger than at solar minimum and the difference increases with depth until {approx}10 Mm. At this depth, the relative difference ({delta}c{sup 2}/c{sup 2}) is less than half of the value observed at the lowest depth determination. At deeper layers, it slowly decreases with depth until there is no difference between maximum and minimum activity.

Rabello-Soares, M. C., E-mail: cristina@sun.stanford.edu [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

2012-02-01T23:59:59.000Z

436

Determining both sound speed and internal source in thermo- and photo-acoustic tomography  

E-Print Network [OSTI]

This paper concerns thermoacoustic tomography and photoacoustic tomography, two couple-physics imaging modalities that attempt to combine the high resolution of ultrasound and the high contrast capabilities of electromagnetic waves. We give sufficient conditions to recover both the sound speed of the medium being probed and the source.

Hongyu Liu; Gunther Uhlmann

2015-02-04T23:59:59.000Z

437

An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel  

E-Print Network [OSTI]

An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel been used to convert wind flow energy into mechanical vibration, which is then transformed-scale renewable energy generating systems such as wind turbines, thermal generators, and solar panels, energy

Stanford University

438

Journal of High Speed Networks 14 (2005) 3957 39 Hello again  

E-Print Network [OSTI]

Journal of High Speed Networks 14 (2005) 39­57 39 IOS Press Hello again: Stabilization of the Hello K, Columbia, MD 21045, USA E-mail: dsidhu@telenix.com Abstract. The Hello protocol in OSPF allows network. This check is carried out by making each router periodically send hello messages to every

Gouda, Mohamed G.

439

ECEN 720 High-Speed Links Circuits and Systems Lab1 -Transmission Lines  

E-Print Network [OSTI]

1 ECEN 720 High-Speed Links Circuits and Systems Lab1 - Transmission Lines Objective To learn transmission lines and time-domain refectometer (TDR). Introduction Wires are used to transmit clocks and data data communication chip design, the wires are often treated as transmission lines. Proper transmission

Palermo, Sam

440

Experimental Evolution of Accelerated Development in Drosophila. 1. Developmental Speed and Larval Survival  

E-Print Network [OSTI]

Experimental Evolution of Accelerated Development in Drosophila. 1. Developmental Speed and Larval://www.jstor.org #12;Evolition, 51(5), 1997, pp. 1536-1551 EXPERIMENTAL EVOLUTION OF ACCELERATED DEVELOPMENT and COI5) for faster development. After 125 generations, the resulting accelerated populations (ACBI5

Rose, Michael R.

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Effect of collector lateral scaling on performance of high-speed SiGe HBTs  

E-Print Network [OSTI]

Effect of collector lateral scaling on performance of high-speed SiGe HBTs with fT > 300 GHz J.-S. Rieh, M. Khater, A. Jeseph, G. Freeman and D. Ahlgren The effect of collector lateral scaling followed by a degradation with decreasing collector width. Possible causes behind the observed trend

Rieh, Jae-Sung

442

High-Speed Serial AER on FPGA Hans Kristian Otnes Berge, Philipp Hafliger  

E-Print Network [OSTI]

High-Speed Serial AER on FPGA Hans Kristian Otnes Berge, Philipp H¨afliger University of Oslo Address-Event Representation (AER) link with a capacity of 41.66Mevents/sec. The link has been implemented. However, many AER processing systems require an ASIC implementation. We thus propose to implement AER

Häfliger, Philipp

443

Benefits of Green Energy and Proportionality in High Speed Wide Area Networks Connecting Data Centers  

E-Print Network [OSTI]

Benefits of Green Energy and Proportionality in High Speed Wide Area Networks Connecting Data Network ModelBackbone Network Model Green EnergyGreen Energy SPR vs. GEARSPR vs. GEAR All vs. Necessary (MuSyC), National Science Foundation (NSF) Project GreenLight, Energy Sciences Network (ESnet), NSF

Simunic, Tajana

444

A modified law of gravitation taking account of the relative speeds of moving masses.  

E-Print Network [OSTI]

1 A modified law of gravitation taking account of the relative speeds of moving masses,version1-9Apr2010 #12;2 Abstract A modified law of gravitation is proposed which takes account law. Its application to several gravitation problems provides a good order of magnitude

Boyer, Edmond

445

High-Speed Networking in Clusters without OS-bypass and Zero-copy (Short Paper)  

E-Print Network [OSTI]

technologies evolved in many ways since their design. It is thus important to recheck the assumptions that led of software support for high-speed networks [3]. 3 Using Memory Copies Zero-copy is known to be useless for limited size messages and even almost useless for less 4 kB. 1 hal-00691967,version1-27Apr2012 #12

Paris-Sud XI, Universit de

446

Radiation-hard/high-speed data transmission using optical links , W. Fernandoa  

E-Print Network [OSTI]

Radiation-hard/high-speed data transmission using optical links K.K. Gana , B. Abic , W. Fernandoa The main radiation effect in a VCSEL is expected to be bulk damage and in a PIN diode the displacement experiment at the Large Hadron Collider (LHC) at CERN (Geneva) use optical links for data transmission

Gan, K. K.

447

A Hybrid macro-micro pedestrians evacuation model to speed up simulation in road networks  

E-Print Network [OSTI]

A Hybrid macro-micro pedestrians evacuation model to speed up simulation in road networks NGUYEN efficient than the use of micro model alone. Keywords: Crowd movement, Hybrid modeling, road networks, multi simulation in a dynamic environments are either based on micro or macro models. These two types of models

Paris-Sud XI, Université de

448

The need for speed: informed land acquisitions for conservation in a dynamic property market  

E-Print Network [OSTI]

.mcdonaldmadden@uq.edu.au Abstract Land acquisition is a common approach to biodiversity conservation but is typically subject of biodiversity assets, costs and land tenures demand a dynamic approach to conservation planning (PossinghamLETTER The need for speed: informed land acquisitions for conservation in a dynamic property market

Queensland, University of

449

Wind speed modeled as a semi-Markov process with memory  

E-Print Network [OSTI]

The increasing interest in renewable energy, particularly in wind, has given rise to the necessity of accurate models for the generation of good synthetic wind speed data. Markov chains are often used with this purpose but better models are needed to reproduce the statistical properties of wind speed data. In a previous paper we showed that semi-Markov processes are more appropriate for this purpose but to reach an accurate reproduction of real data features high order model should be used. In this work we introduce an indexed semi-Markov process that is able to fit real data. We downloaded a database, freely available from the web, in which are included wind speed data taken from L.S.I. -Lastem station (Italy) and sampled every 10 minutes. We then generate synthetic time series for wind speed by means of Monte Carlo simulations. The time lagged autocorrelation is then used to compare statistical properties of the proposed model with those of real data and also with a synthetic time series generated though a ...

D'Amico, Guglielmo; Prattico, Flavio

2012-01-01T23:59:59.000Z

450

Finite speed of propagation and local boundary conditions for wave equations with point interactions  

E-Print Network [OSTI]

We show that the boundary conditions entering in the definition of the self-adjoint operator describing the Laplacian plus a finite number of point interactions are local if and only if the corresponding wave equation has finite speed of propagation

Pavel Kurasov; Andrea Posilicano

2006-02-10T23:59:59.000Z

451

Finite propagation speed for solutions of the wave equation on metric graphs  

E-Print Network [OSTI]

We provide a class of self-adjoint Laplace operators on metric graphs with the property that the solutions of the associated wave equation satisfy the finite propagation speed property. The proof uses energy methods, which are adaptions of corresponding methods for smooth manifolds.

Vadim Kostrykin; Jrgen Potthoff; Robert Schrader

2011-06-04T23:59:59.000Z

452

Teaching Statistics Theory Through Applications D. Nolan and T.P. Speed  

E-Print Network [OSTI]

for engineering and computer science majors. Both courses require students to have studied calculus for two years and probability for one semester. There is no statistics prerequisite for the course. The material coveredTeaching Statistics Theory Through Applications D. Nolan and T.P. Speed Department of Statistics

Nolan, Deborah

453

The RAVE survey: the Galactic escape speed and the mass of the Milky Way  

E-Print Network [OSTI]

We construct new estimates on the Galactic escape speed at various Galactocentric radii using the latest data release of the Radial Velocity Experiment (RAVE DR4). Compared to previous studies we have a database larger by a factor of 10 as well as reliable distance estimates for almost all stars. Our analysis is based on the statistical analysis of a rigorously selected sample of 90 high-velocity halo stars from RAVE and a previously published data set. We calibrate and extensively test our method using a suite of cosmological simulations of the formation of Milky Way-sized galaxies. Our best estimate of the local Galactic escape speed, which we define as the minimum speed required to reach three virial radii R340, is 537 +59 -43 km/s (90% confidence) with an additional 5% systematic uncertainty, where R340 is the Galactocentric radius encompassing a mean overdensity of 340 times the critical density for closure in the Universe. From the escape speed we further derive estimates of the mass of the Galaxy using...

Piffl, Til; Binney, James; Steinmetz, Matthias; Scholz, Ralf-Dieter; Williams, Mary E K; de Jong, Roelof S; Kordopatis, Georges; Matijevic, Gal; Bienayme, Olivier; Bland-Hawthorn, Joss; Boeche, Corrado; Freeman, Ken; Gibson, Brad; Gilmore, Gerald; Grebel, Eva K; Helmi, Amina; Munari, Ulisse; Navarro, Julio F; Parker, Quentin; Reid, Warren A; Seabroke, George; Watson, Fred; Wyse, Rosemary F G; Zwitter, Tomaz

2013-01-01T23:59:59.000Z

454

Effects of Lewis number and ignition energy on the determination of laminar flame speed  

E-Print Network [OSTI]

, it affects the fuel burning rate in internal combustion engines and the engine's performance and emissions Engineering, Princeton University, Princeton, NJ 08544, USA Abstract The trajectories of outwardly propagating. Published by Elsevier Inc. on behalf of The Combustion Institute. Keywords: Laminar flame speed; Spherical

Ju, Yiguang

455

A narrow-band high-speed switched-capacitor sixth order bandpass ladder filter  

E-Print Network [OSTI]

In narrow-band high-speed switched-capacitor filters, the main limitation comes from the capacitance spread and from amplifier settling time. A secondary clock, that averages at an integer fraction of the main clock signal, is used to reduce...

Adut, Jozef

2002-01-01T23:59:59.000Z

456

Methods to Speed Up Error Back-Propagation Learning Algorithm DILIP SARKAR  

E-Print Network [OSTI]

Methods to Speed Up Error Back-Propagation Learning Algorithm DILIP SARKAR University of Miami's address: D. Sarkar, Department of Mathematics and Computer Science, University of Miami, Coral Gables, FL Surveys. Vol. 27, No. 4, December 1995 #12;520 q Dilip Sarkar I CONTENTS 1. 2 3. 4. 5. INTRODUCTION

Sarkar, Dilip

457

Low-order simultaneous stabilization of linear bicycle models at different forward speeds  

E-Print Network [OSTI]

Low-order simultaneous stabilization of linear bicycle models at different forward speeds A. N. G¨undes¸1 and A. Nanjangud2 Abstract-- Linear models of bicycles with rigidly attached riders, operating-track vehicles with human riders, such as bicycles, present challenging problems of modeling and control. Based

Gundes, A. N.

458

Design of optimal digital controller for stable super-high-speed permanent-magnet synchronous  

E-Print Network [OSTI]

collaborative design scheme of a super-high-speed permanent-magnet synchronous motor (PMSM) and its digital stability and performance. Since the systematic design of the PMSM can ensure its stability over the full the efficiency and performance of the PMSM. The unique feature in the proposed optimal V/f control is its design

Wu, Thomas

459

A passivity-based controller under low sampling for speed control of PMSM  

E-Print Network [OSTI]

A passivity-based controller under low sampling for speed control of PMSM M. Khanchoul a , M: Permanent magnet synchronous motor (PMSM) Sampled-data control Port-controlled Hamiltonian systems IDA. All rights reserved. 1. Introduction Nowadays, PMSM is used in many fields. This gain in popularity

Paris-Sud XI, Université de

460

The wind speed profile at offshore wind farm sites Bernhard Lange(1)  

E-Print Network [OSTI]

The wind speed profile at offshore wind farm sites Bernhard Lange(1) , Søren E. Larsen(2) , Jørgen in Europe will come from offshore sites. The first large offshore wind farms are #12;currently being built feasibility of offshore wind power utilisation depends on the favourable wind conditions offshore compared

Heinemann, Detlev

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Analytical Modelling of Wind Speed Deficit in Large Offshore Wind Farms  

E-Print Network [OSTI]

Analytical Modelling of Wind Speed Deficit in Large Offshore Wind Farms Sten Frandsen*, Rebecca areas.As is often the need for offshore wind farms, the model handles a regular array geometry for offshore wind farms, the model handles a priori a regular array geometry with straight rows of wind

Pryor, Sara C.

462

The Probability Distribution of Land Surface Wind Speeds ADAM H. MONAHAN AND YANPING HE  

E-Print Network [OSTI]

al. 2004), wind extremes (e.g., Gastineau and Soden 2009), and wind power climatologies (e.g., Troen) and the prediction of the wind power re- source and extreme surface winds in present and future climates (e.g., TroenThe Probability Distribution of Land Surface Wind Speeds ADAM H. MONAHAN AND YANPING HE School

He, Yanping

463

Optimum propeller wind turbines  

SciTech Connect (OSTI)

The Prandtl-Betz-Theodorsen theory of heavily loaded airscrews has been adapted to the design of propeller windmills which are to be optimized for maximum power coefficient. It is shown that the simpler, light-loading, constant-area wake assumption can generate significantly different ''optimum'' performance and geometry, and that it is therefore not appropriate to the design of propeller wind turbines when operating in their normal range of high-tip-speed-to-wind-speed ratio. Design curves for optimum power coefficient are presented and an example of the design of a typical two-blade optimum rotor is given.

Sanderson, R.J.; Archer, R.D.

1983-11-01T23:59:59.000Z

464

New York state high-speed surface transportation study: Final report  

SciTech Connect (OSTI)

In 1990, New York State Governor Mario M. Cuomo created an interagency task force under the leadership of Lt. Governor Stan Lundine to investigate the potential of high speed ground transportation (HSGT) systems. Building on information from previous agency activities, including consultant efforts contracted by the New York State Energy Research and Development Authority (NYSERDA), the New York State Thruway Authority (NYSTA), and in-house analyses performed by New York State Department of Transportation (NYSDOT), the task force focused on the corridor between New York City and the Niagara Frontier. In December 1991, NYSERDA issued a contract for a study of high speed ground transportation options for New York State. The study`s objective was to assess potential rights-of-way, ridership, energy and environmental impacts, economic benefits, capital, operating, and maintenance costs, and financial viability of HSGT systems. This study builds upon and supplements previous and on-going HSGT activities conducted by the members of the interagency task force. These activities include: Maglev Technical and Economic Feasibility Study (NYSERDA); Maglev Demonstration Site Investigation (NYSTA); and New York/Massachusetts High Speed Ground Transportation Study (NYSDOT). This study is intended to verify and refine previous information and analyses and provide supplemental information and insights to be used in determining if additional investigation and activities involving HSGT are desirable for New York State. This study evaluates HSGT technologies capable of speeds significantly higher than those achieved with the present rail system. Three HSGT categories are used in this study: incremental rail improvement, very high-speed rail, and Maglev.

Not Available

1994-08-01T23:59:59.000Z

465

Extended Constant Power Speed Range of the Brushless DC Motor Through Dual Mode Inverter Control  

SciTech Connect (OSTI)

The trapezoidal back electromotive force (emf) brushless direct current (dc) motor (BDCM) with surface-mounted magnets has high-power density and efficiency especially when rare-earth magnet materials are used. Traction applications, such as electric vehicles, could benefit significantly from the use of such motors. Unfortunately, a practical means for driving the motor over a constant power speed ratio (CPSR) of 5:1 or more has not yet been developed. A key feature of these motors is that they have low internal inductance. The phase advance method is effective in controlling the motor power over such a speed range, but the current at high speed may be several times greater than that required at the base speed. The increase in current during high-speed operation is due to the low motor inductance and the action of the bypass diodes of the inverter. The use of such a control would require increased current rating of the inverter semiconductors and additional cooling for the inverter, where the conduction losses increase proportionally with current, and especially for the motor, where the losses increase with the square of the current. The high current problems of phase advance can be mitigated by adding series inductance; however, this reduces power density, requires significant increase in supply voltage, and leaves the CPSR performance of the system highly sensitive to variations in the available voltage. A new inverter topology and control scheme has been developed that can drive low-inductance BDCMs over the CPSR that would be required in electric vehicle applications. This new controller is called the dual-mode inverter control (DMIC). It is shown that the BDCM has an infinite CPSR when it is driven by the DMIC.

Lawler, J.S.

2000-06-23T23:59:59.000Z

466

Solar wind suprathermal electron Stahl widths across high-speed stream structures  

SciTech Connect (OSTI)

Suprathermal electrons (100-1500 eV) observed in the solar wind typically show a strahl distribution, that is, a beam directed away from the Sun along the magnetic field direction. The strahl width observed at 1 AU is highly variable, ranging from 10-70 degrees. The obsenred finite width of the strahl results from the competition between beam focusing as the interplanetary magnetic field strength drops with distance from the Sun, and pitch-angle scattering as the beam interacts with the solar wind plasma in transit from the sun. Here we examine strahl width, observed with ACE SWEPAM across high-speed stream structures to investigate variations in electron scattering as a function of local plasma characteristics. We find that narrow strahls (less than 20 degrees wide), indicating reduced scattering, are observed within high-speed streams. Narrow strahls are also observed in both very low temperature solar wind, in association with ICMEs. Case studies of high-speed streams typically show the strahl narrowing at the leading edge of the stream. In some cases, the strahl narrows at the reverse shock or pressure wave, in other cases at the stream interface. The narrowing can either occur discontinuously or gradually over a period of hours. Within the high-speed wind, the strahl remains narrow for a period of hours to days, and then gradually broadens. The strahl width is roughly constant at all energies across these structures. For some fraction of high-speed streams, counterstreaming is associated with passage of the corotating interaction region. In these cases, we find the widths of the two counterstreaming beams frequently differ by more than 40 degrees. This dramatic difference in strahl width contrasts with observations in the solar wind as a whole, in which counterstreaming strahls typically differ in width by less than 20 degrees.

Skoug, Ruth M [Los Alamos National Laboratory; Steinberg, John T [Los Alamos National Laboratory; Goodrich, Katherine A [Los Alamos National Laboratory; Anderson, Brett R [DARTMUTH UNIV.

2011-01-03T23:59:59.000Z

467

Q: When planning a wind farm, how are wind resources estimated? And if the average wind speed is known at 10 meters is there a general rule for estimating the wind speed at  

E-Print Network [OSTI]

Q: When planning a wind farm, how are wind resources estimated? And if the average wind speed is known at 10 meters is there a general rule for estimating the wind speed at larger heights above ground level? The wind resource at a wind farm can be estimated in two ways: by measurement or by modeling

468

Observed one-dimensional return stroke propagation speeds in the bottom 170 m of a rocket-triggered lightning channel  

E-Print Network [OSTI]

Observed one-dimensional return stroke propagation speeds in the bottom 170 m of a rocket; revised 22 June 2004; accepted 8 July 2004; published 20 August 2004. [1] The return-stroke propagation speeds of five strokes from a seven-stroke triggered lightning flash are measured, with a 2 ns sampling

Florida, University of

469

A 1.8V 2-2 cascade Sigma-Delta modulator for high speed applications  

E-Print Network [OSTI]

In order to satisfy today's most important requirements of the A/D and D/A converters that are low voltage and high speed operation, a low voltage and high speed circuit solutions for [] modulators are strongly demanding. However, simply reducing...

Lee, Kye-Shin

2002-01-01T23:59:59.000Z

470

Effect of Welding Speed and Defocusing Distance on the Quality of Laser Welded Ti-6Al-4V  

E-Print Network [OSTI]

Effect of Welding Speed and Defocusing Distance on the Quality of Laser Welded Ti-6Al-4V A:YAG laser, Laser welding, Ti-6Al-4V alloy Abstract In this study, the weldability of 5.1-mm thick Ti-6Al-4V at various welding speeds and defocusing distances. The joint quality was characterized in terms of weld

Medraj, Mamoun

471

296 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 57, NO. 1, JANUARY 2010 Very-High-Speed Slotless Permanent-Magnet  

E-Print Network [OSTI]

cell compressor [9]), machining industry (machine tool [10], micromachining), home appliance industry-High-Speed Slotless Permanent-Magnet Motors: Analytical Modeling, Optimization, Design, and Torque Measurement Methods-high-speed (VHS) slotless permanent-magnet motor design procedure using an analytical model. The model is used

Psaltis, Demetri

472

The impact of high-speed rail and low-cost carriers on European air passenger traffic  

E-Print Network [OSTI]

The impact of high-speed rail and low-cost carriers on European air passenger traffic Regina R, and market characteristics on air traffic; and 2) the impact of high-speed rail and low-cost in system-wide air travel demand, whereas the expansion of low-cost carriers has led to a significant

Gummadi, Ramakrishna

473

Research on Pinches driven by SPEED 2 Generator: Hard X-ray and Neutron Emission in Plasma Focus Configuration.  

E-Print Network [OSTI]

Research on Pinches driven by SPEED 2 Generator: Hard X-ray and Neutron Emission in Plasma Focus works developed in SPEED2 at Düsseldorf were done in a plasma focus configuration for soft X considers experiments in different pinch configurations (plasma focus, gas puffed plasma focus, gas embedded

Paris-Sud XI, Université de

474

Abstract--A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous  

E-Print Network [OSTI]

1 Abstract--A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous generators (MPMSGs) drive-train configuration is employed in the wind turbine of this variable speed wind turbine based on multiple generators drive-train configuration. Index Terms--Wind power

Chen, Zhe

475

Motorcycle Maximal Safe Speed in Cornering Situation H. Slimi and D. Ichalal and H. Arioui and S. Mammar  

E-Print Network [OSTI]

Motorcycle Maximal Safe Speed in Cornering Situation H. Slimi and D. Ichalal and H. Arioui and S motorcycle speed in curves. The three main actors which are the vehicle, the driver and the infrastructure the last decade. However analysis of accident statistics shows that the number of death when a motorcycle

Paris-Sud XI, Université de

476

100-Year Return Value Estimates for Ocean Wind Speed and Significant Wave Height from the ERA-40 Data  

E-Print Network [OSTI]

and time variability of significant wave height and wind speed on the prediction of their extreme values of this dataset makes it ideal for the study of extreme wind and wave phenomena over the whole globe. Initial100-Year Return Value Estimates for Ocean Wind Speed and Significant Wave Height from the ERA-40

Haak, Hein

477

Experimental Investigation of Spark-Ignited Combustion with High-Octane Biofuels and EGR. 2. Fuel and EGR Effects on Knock-Limited Load and Speed  

SciTech Connect (OSTI)

The present study experimentally investigates spark-ignited combustion with 87 AKI E0 gasoline in its neat form and in midlevel alcohol gasoline blends with 24% vol/vol isobutanol gasoline (IB24) and 30% vol/vol ethanol gasoline (E30). A single-cylinder research engine is used with an 11.85:1 compression ratio, hydraulically actuated valves, laboratory intake air, and was capable of external exhaust gas recirculation (EGR). Experiments were conducted with all fuels to full-load conditions with = 1, using both 0% and 15% external-cooled EGR. Higher octane number biofuel blends exhibited increased stoichiometric torque capability at this compression ratio, where the unique properties of ethanol enabled a doubling of the stoichiometric torque capability with E30 as compared to that of 87AKI, up to 20 bar IMEPg (indicating mean effective pressure gross) at = 1. The results demonstrate that for all fuels, EGR is a key enabler for increasing engine efficiency but is less useful for knock mitigation with E30 than for 87AKI gasoline or IB24. Under knocking conditions, 15% EGR is found to offer 1 CA of CA50 timing advance with E30, whereas up to 5 CA of CA50 advance is possible with knock-limited 87AKI gasoline. Compared to 87AKI, both E30 and IB24 are found to have reduced adiabatic flame temperature and shorter combustion durations, which reduce knocking propensity beyond that indicated by the octane number. However, E30+0% EGR is found to exhibit the better antiknock properties than either 87AKI+15% EGR or IB24+15% EGR, expanding the knock limited operating range and engine stoichiometric torque capability at high compression ratio. Furthermore, the fuel sensitivity (S) of E30 was attributed to reduced speed sensitivity of E30, expanding the low-speed stoichiometric torque capability at high compression ratio. The results illustrate that intermediate alcohol gasoline blends exhibit exceptional antiknock properties and performance beyond that indicated by the octane number tests, particularly E30.

Splitter, Derek A [ORNL] [ORNL; Szybist, James P [ORNL] [ORNL

2013-01-01T23:59:59.000Z

478

Design of a speed meter interferometer proof-of-principle experiment  

E-Print Network [OSTI]

The second generation of large scale interferometric gravitational wave detectors will be limited by quantum noise over a wide frequency range in their detection band. Further sensitivity improvements for future upgrades or new detectors beyond the second generation motivate the development of measurement schemes to mitigate the impact of quantum noise in these instruments. Two strands of development are being pursued to reach this goal, focusing both on modifications of the well-established Michelson detector configuration and development of different detector topologies. In this paper, we present the design of the world's first Sagnac speed meter interferometer which is currently being constructed at the University of Glasgow. With this proof-of-principle experiment we aim to demonstrate the theoretically predicted lower quantum noise in a Sagnac interferometer compared to an equivalent Michelson interferometer, to qualify Sagnac speed meters for further research towards an implementation in a future generation large scale gravitational wave detector, such as the planned Einstein Telescope observatory.

C. Grf; B. W. Barr; A. S. Bell; F. Campbell; A. V. Cumming; S. L. Danilishin; N. A. Gordon; G. D. Hammond; J. Hennig; E. A. Houston; S. H. Huttner; R. A. Jones; S. S. Leavey; H. Lck; J. Macarthur; M. Marwick; S. Rigby; R. Schilling; B. Sorazu; A. Spencer; S. Steinlechner; K. A. Strain; S. Hild

2014-09-11T23:59:59.000Z

479

Influences of carrier diffusion and radial mode field pattern on high speed characteristics for microring lasers  

SciTech Connect (OSTI)

High-speed directly modulated microlasers are potential light sources for on-chip optical interconnection and photonic integrated circuits. In this Letter, dynamic characteristics are studied for microring lasers by rate equation analysis considering radial carrier hole burning and diffusion and experimentally. The coupled modes with a wide radial field pattern and the injection current focused in the edge area of microring resonator can greatly improve the high speed response curve due to the less carrier hole burning. The small-signal response curves of a microring laser connected with an output waveguide exhibit a larger 3?dB bandwidth and smaller roll-off at low frequency than that of the microdisk laser with the same radius of 15??m, which accords with the simulation results.

Lv, Xiao-Meng; Huang, Yong-Zhen, E-mail: yzhuang@semi.ac.cn; Yang, Yue-De; Zou, Ling-Xiu; Long, Heng; Liu, Bo-Wen; Xiao, Jin-Long; Du, Yun [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

2014-04-21T23:59:59.000Z

480

Large motion high cycle high speed optical fibers for space based applications.  

SciTech Connect (OSTI)

Future remote sensing applications will require higher resolution and therefore higher data rates (up to perhaps 100 gigabits per second) while achieving lower mass and cost. A current limitation to the design space is high speed high bandwidth data does not cross movable gimbals because of cabling issues. This requires the detectors to be off gimbal. The ability to get data across the gimbal would open up efficiencies in designs where the detectors and the electronics can be placed anywhere on the system. Fiber optic cables provide light weight high speed high bandwidth connections. Current options are limited to 20,000 cycles as opposed to the 1,000,000 cycles needed for future space based applications. To extend this to the million+ regime, requires a thorough understanding of the failure mechanisms and the materials, proper selection of materials (e.g., glass and jacket material) allowable geometry changes to the cable, radiation hardness, etc.

Stromberg, Peter G.; Tandon, Rajan; Gibson, Cory S; Reedlunn, Benjamin; Rasberry, Roger David; Rohr, Garth David

2014-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "tip-speed ratio-the speed" 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

Planck Scale Induced Speed of Sound in a Trapped Bose-Einstein Condensate  

E-Print Network [OSTI]

In the present work, we analyze the corrections caused by an anomalous dispersion relation, suggested in several quantum gravity models, upon the speed of sound in a weakly interacting Bose--Einstein Condensate, trapped in a potential of the form $V(r)\\sim r^{2}$. We show that the corresponding ground state energy and consequently, the associated speed of sound, present corrections respect to the usual case, which may be used to explore the sensitivity to Planck--scale effects on these relevant properties associated with the condensate. Indeed, we stress that this type of macroscopic bodies may be more sensitive, under certain conditions, to Planck--scale manifestations than its constituents. In addition, we prove that the inclusion of a trapping potential, together with many--body contributions, improves the sensitivity to Planck--scale signals, compared to the homogeneous system.

E. Castellanos; J. I. Rivas; V. Domnguez-Rocha

2014-07-11T23:59:59.000Z

482

Temperature and humidity control during cooling and dehumidifying by compressor and evaporator fan speed variation  

SciTech Connect (OSTI)

The accurate control of temperature and relative humidity during cooling and dehumidifying air-conditioning processes may be achieved by compressor and evaporator fan speed variation. Proportional-integral-differential (PID) control methods are shown to be suitable for attaining compressor and evaporator fan speeds such that the sensible and latent components of the refrigeration system capacity equal the sensible and latent components of the system load. The feasibility of the control method has been verified experimentally. A numerical model of an environmental control system, including refrigeration, space, and PID control subsystems, has been developed. The model is suitable for determining system response to variations of PID coefficient values and to variations of system loads.

Krakow, K.I.; Lin, S.; Zeng, Z.S. [Concordia Univ., Montreal, Quebec (Canada). Dept. of Mechanical Engineering

1995-08-01T23:59:59.000Z

483

Device for modular input high-speed multi-channel digitizing of electrical data  

DOE Patents [OSTI]

A multi-channel high-speed digitizer module converts a plurality of analog signals to digital signals (digitizing) and stores the signals in a memory device. The analog input channels are digitized simultaneously at high speed with a relatively large number of on-board memory data points per channel. The module provides an automated calibration based upon a single voltage reference source. Low signal noise at such a high density and sample rate is accomplished by ensuring the A/D converters are clocked at the same point in the noise cycle each time so that synchronous noise sampling occurs. This sampling process, in conjunction with an automated calibration, yields signal noise levels well below the noise level present on the analog reference voltages.

VanDeusen, Alan L. (Lee's Summit, MO); Crist, Charles E. (Waxahachie, TX)

1995-09-26T23:59:59.000Z

484

Device for modular input high-speed multi-channel digitizing of electrical data  

DOE Patents [OSTI]

A multi-channel high-speed digitizer module converts a plurality of analog signals to digital signals (digitizing) and stores the signals in a memory device. The analog input channels are digitized simultaneously at high speed with a relatively large number of on-board memory data points per channel. The module provides an automated calibration based upon a single voltage reference source. Low signal noise at such a high density and sample rate is accomplished by ensuring the A/D converters are clocked at the same point in the noise cycle each time so that synchronous noise sampling occurs. This sampling process, in conjunction with an automated calibration, yields signal noise levels well below the noise level present on the analog reference voltages. 1 fig.

VanDeusen, A.L.; Crist, C.E.

1995-09-26T23:59:59.000Z

485

Experimental flame speed in multi-layered nano-energetic materials  

SciTech Connect (OSTI)

This paper deals with the reaction of dense Metastable Intermolecular Composite (MIC) materials, which have a higher density than conventional energetic materials. The reaction of a multilayer thin film of aluminum and copper oxide has been studied by varying the substrate material and thicknesses. The in-plane speed of propagation of the reaction was experimentally determined using a time of- flight technique. The experiment shows that the reaction is completely quenched for a silicon substrate having an intervening silica layer of less than 200 nm. The speed of reaction seems to be constant at 40 m/s for silica layers with a thickness greater than 1 {mu}m. Different substrate materials such as glass and photoresist were also used. (author)

Manesh, Navid Amini; Basu, Saptarshi; Kumar, Ranganathan [Department of Mechanical, Material and Aerospace Engineering, University of Central Florida, Orlando, FL (United States)

2010-03-15T23:59:59.000Z

486

System and method that suppresses intensity fluctuations for free space high-speed optical communication  

DOE Patents [OSTI]

A high-speed (Gbps), free space optical communication system is based on spectral encoding of radiation from a wide band light source, such as a laser. By using partially coherent laser beams in combination with a relatively slow photosensor, scintillations can be suppressed by orders of magnitude for distances of more than 10 km. To suppress the intensity fluctuations due to atmospheric turbulence, a source with partial transverse coherence in combination with slow response time photodetector is used. Information is encoded in the spectral domain of a wideband optical source by modulation of spectral amplitudes. A non-coherent light source with wide spectrum (an LED, for example) may be used for high-speed communication over short (less than about a mile) distances.

Berman, Gennady P. (Los Alamos, NM); Bishop, Alan R. (Los Alamos, NM); Nguyen, Dinh C. (Los Alamos, NM); Chernobrod, Boris M. (Santa Fe, NM); Gorshkov, Vacheslav N. (Kiev, UA)

2009-10-13T23:59:59.000Z

487

SNe Data Analysis in Variable Speed of Light Cosmologies without Cosmological Constant  

E-Print Network [OSTI]

In this work, we aim to show the possibilities of the variable speed of light (VSL) theory in explaining the type Ia supernovae observations without introducing dark energy. The speed of light is assumed to be scale factor dependent, which is the most popular assumption in VSL theory. We show the modified calculation of the distance modulus, and the validity of the redshift-scale factor relation in VSL theory. Three different models of VSL are tested SNe data-sets with proper constraints on the model parameters. The comparison of the three models and flat $\\Lambda$CDM in distance modulus is showed. Some basic problems and the difficulties of the confirmation of the VSL theory are also discussed

Peng-fei Zhang; Xin-he Meng

2014-04-30T23:59:59.000Z

488

Dynamic stability of running: The effects of speed and leg amputations on the maximal Lyapunov exponent  

SciTech Connect (OSTI)

In this paper, we study dynamic stability during running, focusing on the effects of speed, and the use of a leg prosthesis. We compute and compare the maximal Lyapunov exponents of kinematic time-series data from subjects with and without unilateral transtibial amputations running at a wide range of speeds. We find that the dynamics of the affected leg with the running-specific prosthesis are less stable than the dynamics of the unaffected leg and also less stable than the biological legs of the non-amputee runners. Surprisingly, we find that the center-of-mass dynamics of runners with two intact biological legs are slightly less stable than those of runners with amputations. Our results suggest that while leg asymmetries may be associated with instability, runners may compensate for this effect by increased control of their center-of-mass dynamics.

Look, Nicole [Department of Applied Mathematics, University of Colorado Boulder, Boulder, Colorado 80309 (United States)] [Department of Applied Mathematics, University of Colorado Boulder, Boulder, Colorado 80309 (United States); Arellano, Christopher J.; Grabowski, Alena M.; Kram, Rodger [Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado 80309 (United States)] [Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado 80309 (United States); McDermott, William J. [The Orthopedic Specialty Hospital, Murray, Utah 84107 (United States)] [The Orthopedic Specialty Hospital, Murray, Utah 84107 (United States); Bradley, Elizabeth [Department of Computer Science, University of Colorado Boulder, Boulder, Colorado 80309, USA and Santa Fe Institute, Santa Fe, New Mexico 87501 (United States)] [Department of Computer Science, University of Colorado Boulder, Boulder, Colorado 80309, USA and Santa Fe Institute, Santa Fe, New Mexico 87501 (United States)

2013-12-15T23:59:59.000Z

489

Experimental response of gas hybrid bearings for high speed oil-free turbomachinery  

E-Print Network [OSTI]

with sponsorship by the Texas State Education Foundation, the Houston Professional Section of the Society of Tribologists and Lubrication Engineers, the Turbomachinery Research Consortium, DynaTech Engineering, Inc. , and the State of Texas Energy Resources...-free bearing support elements in small to moderate size turbomachinery (& 1 MW). While oil-lubricated fluid film bearings provide adequate stiffness and damping characteristics, these support systems are hmited by speed and temperature, and require...

Wilde, Deborah Anne

2002-01-01T23:59:59.000Z

490

GyPSuM: A Detailed Tomographic Model of Mantle Density and Seismic Wave Speeds  

SciTech Connect (OSTI)

GyPSuM is a tomographic model fo mantle seismic shear wave (S) speeds, compressional wave (P) speeds and detailed density anomalies that drive mantle flow. the model is developed through simultaneous inversion of seismic body wave travel times (P and S) and geodynamic observations while considering realistic mineral physics parameters linking the relative behavior of mantle properties (wave speeds and density). Geodynamic observations include the (up to degree 16) global free-air gravity field, divergence of the tectonic plates, dynamic topography of the free surface, and the flow-induced excess ellipticity of the core-mantle boundary. GyPSuM is built with the philosophy that heterogeneity that most closely resembles thermal variations is the simplest possible solution. Models of the density field from Earth's free oscillations have provided great insight into the density configuration of the mantle; but are limited to very long-wavelength solutions. Alternatively, simply scaling higher resolution seismic images to density anomalies generates density fields that do not satisfy geodynamic observations. The current study provides detailed density structures in the mantle while directly satisfying geodynamic observations through a joint seismic-geodynamic inversion process. Notable density field observations include high-density piles at the base of the superplume structures, supporting the fundamental results of past normal mode studies. However, these features are more localized and lower amplitude than past studies would suggest. When we consider all seismic anomalies in GyPSuM, we find that P and S-wave speeds are strongly correlated throughout the mantle. However, correlations between the high-velocity S zones in the deep mantle ({approx} 2000 km depth) and corresponding P-wave anomalies are very low suggesting a systematic divergence from simplified thermal effects in ancient subducted slab anomalies. Nevertheless, they argue that temperature variations are the primary cause of P-wave, S-wave, and density anomalies in the mantle.

Simmons, N A; Forte, A M; Boschi, L; Grand, S P

2010-03-30T23:59:59.000Z

491

Variable-speed wind power system with improved energy capture via multilevel conversion  

DOE Patents [OSTI]

A system and method for efficiently capturing electrical energy from a variable-speed generator are disclosed. The system includes a matrix converter using full-bridge, multilevel switch cells, in which semiconductor devices are clamped to a known constant DC voltage of a capacitor. The multilevel matrix converter is capable of generating multilevel voltage wave waveform of arbitrary magnitude and frequencies. The matrix converter can be controlled by using space vector modulation.

Erickson, Robert W.; Al-Naseem, Osama A.; Fingersh, Lee Jay

2005-05-31T23:59:59.000Z

492

Development of a dynamic radiographic capability using high-speed video  

SciTech Connect (OSTI)

High-speed video equipment can be used to optically image up to 2000 full frames per second or 12,000 partial frames per second. X-ray image intensifiers have historically been used to image radiographic images at 30 frames per second. By combining these two types of equipment, it is possible to perform dynamic x-ray imaging of up to 2,000 full frames per second. The technique has been demonstrated using conventional, industrial x-ray sources such as 150 kV and 300 kV constant potential x-ray generators, 2.5 MeV Van de Graaffs, and linear accelerators. A crude form of this high-speed radiographic imaging has been shown to be possible with a cobalt 60 source. Use of a maximum aperture lens makes best use of the available light output from the image intensifier. The x-ray image intensifier input and output fluors decay rapidly enough to allow the high frame rate imaging. Data are presented on the maximum possible video frame rates versus x-ray penetration of various thicknesses of aluminum and steel. Photographs illustrate typical radiographic setups using the high speed imaging method. Video recordings show several demonstrations of this technique with the played-back x-ray images slowed down up to 100 times as compared to the actual event speed. Typical applications include boiling type action of liquids in metal containers, compressor operation with visualization of crankshaft, connecting rod and piston movement and thermal battery operation. An interesting aspect of this technique combines both the optical and x-ray capabilities to observe an object or event with both external and internal details with one camera in a visual mode and the other camera in an x-ray mode. This allows both kinds of video images to appear side by side in a synchronized presentation.

Bryant, L.E. Jr.

1984-01-01T23:59:59.000Z

493

Potentials of a Classical Point-Charge Moving at the Speed of Light  

E-Print Network [OSTI]

Retarded potentials of a point-charge are considered, and new ones presented, including potentials of a point-charge moving at the speed of light. The Lienard-Wiechert potential (together with the usual retardation condition) is only one of many retarded four-potentials that satisfy the homogeneous wave equation and the Lorenz Gauge condition in free space. This analysis is in the context of Special Relativity and classical electrodynamics.

Andrew T. Hyman

2013-07-13T23:59:59.000Z

494

Occurrence of high-speed solar wind streams over the Grand Modern Maximum  

E-Print Network [OSTI]

In the declining phase of the solar cycle, when the new-polarity fields of the solar poles are strengthened by the transport of same-signed magnetic flux from lower latitudes, the polar coronal holes expand and form non-axisymmetric extensions toward the solar equator. These extensions enhance the occurrence of high-speed solar wind streams (HSS) and related co-rotating interaction regions in the low-latitude heliosphere, and cause moderate, recurrent geomagnetic activity in the near-Earth space. Here, using a novel definition of geomagnetic activity at high (polar cap) latitudes and the longest record of magnetic observations at a polar cap station, we calculate the annually averaged solar wind speeds as proxies for the effective annual occurrence of HSS over the whole Grand Modern Maximum (GMM) from 1920s onwards. We find that a period of high annual speeds (frequent occurrence of HSS) occurs in the declining phase of each solar cycle 16-23. For most cycles the HSS activity clearly maximizes during one year...

Mursula, Kalevi; Holappa, Lauri

2015-01-01T23:59:59.000Z

495

Airflow regulation in variable-speed systems for residential HVAC applications  

SciTech Connect (OSTI)

In the majority of heating, ventilating, and air-conditioning (HVAC) systems, air is the final medium for adding or extracting heat from or to the space to be air conditioned. Air is heated by passing it over a heat transfer device called a coil, which is a heat exchanger with air on the outside and the primary heating/cooling medium (water, steam, electricity, refrigerant, etc.) on the inside. One of the major factors determining heat transfer is the airflow rate, which can be controlled by mechanical means or by controlling the speed of the fan. Centrifugal fans driven by single-speed induction motors traditionally have been used in the JVAC industry but have an airflow characteristic that depends on the static pressure seen by the system. Variable-speed systems are starting to emerge as a strong alternative to traditional systems because of their ability to match the demand of the air-conditioned space, resulting in higher efficiencies and higher comfort. System efficiency can be improved by constraining the range of airflows provided by the fan or blower system in response to system pressure, that is, by controlling the airflow over the heat exchanger. This paper presents a method to regulate airflow independent of the static pressure and without the need for airflow sensors.

Becerra, R.C.; Beifus, B.L. [General Electric Co., Fort Wayne, IN (United States)

1996-11-01T23:59:59.000Z

496

Adaptive AFM scan speed control for high aspect ratio fast structure tracking  

SciTech Connect (OSTI)

Improved imaging rates in Atomic Force Microscopes (AFM) are of high interest for disciplines such as life sciences and failure analysis of semiconductor wafers, where the sample topology shows high aspect ratios. Also, fast imaging is necessary to cover a large surface under investigation in reasonable times. Since AFMs are composed of mechanical components, they are associated with comparably low resonance frequencies that undermine the effort to increase the acquisition rates. In particular, high and steep structures are difficult to follow, which causes the cantilever to temporarily loose contact to or crash into the sample. Here, we report on a novel approach that does not affect the scanner dynamics, but adapts the lateral scanning speed of the scanner. The controller monitors the control error signal and, only when necessary, decreases the scan speed to allow the z-piezo more time to react to changes in the sample's topography. In this case, the overall imaging rate can be significantly increased, because a general scan speed trade-off decision is not needed and smooth areas are scanned fast. In contrast to methods trying to increase the z-piezo bandwidth, our method is a comparably simple approach that can be easily adapted to standard systems.

Ahmad, Ahmad; Schuh, Andreas; Rangelow, Ivo W. [Department of Microelectronic and Nanoelectronic Systems, Faculty of Electrical Engineering and Information Technology Ilmenau University of Technology, Gustav-Kirchhoffstr. 1, 98684 Ilmenau (Germany)

2014-10-15T23:59:59.000Z

497

FBI Fingerprint Image Capture System High-Speed-Front-End throughput modeling  

SciTech Connect (OSTI)

The Federal Bureau of Investigation (FBI) has undertaken a major modernization effort called the Integrated Automated Fingerprint Identification System (IAFISS). This system will provide centralized identification services using automated fingerprint, subject descriptor, mugshot, and document processing. A high-speed Fingerprint Image Capture System (FICS) is under development as part of the IAFIS program. The FICS will capture digital and microfilm images of FBI fingerprint cards for input into a central database. One FICS design supports two front-end scanning subsystems, known as the High-Speed-Front-End (HSFE) and Low-Speed-Front-End, to supply image data to a common data processing subsystem. The production rate of the HSFE is critical to meeting the FBI`s fingerprint card processing schedule. A model of the HSFE has been developed to help identify the issues driving the production rate, assist in the development of component specifications, and guide the evolution of an operations plan. A description of the model development is given, the assumptions are presented, and some HSFE throughput analysis is performed.

Rathke, P.M.

1993-09-01T23:59:59.000Z

498

ARE660 Wind Generator: Low Wind Speed Technology for Small Turbine Development  

SciTech Connect (OSTI)

This project is for the design of a wind turbine that can generate most or all of the net energy required for homes and small businesses in moderately windy areas. The purpose is to expand the current market for residential wind generators by providing cost effective power in a lower wind regime than current technology has made available, as well as reduce noise and improve reliability and safety. Robert W. Preus experience designing and/or maintaining residential wind generators of many configurations helped identify the need for an improved experience of safety for the consumer. Current small wind products have unreliable or no method of stopping the wind generator in fault or high wind conditions. Consumers and their neighbors do not want to hear their wind generators. In addition, with current technology, only sites with unusually high wind speeds provide payback times that are acceptable for the on-grid user. Abundant Renewable Energys (ARE) basic original concept for the ARE660 was a combination of a stall controlled variable speed small wind generator and automatic fail safe furling for shutdown. The stall control for a small wind generator is not novel, but has not been developed for a variable speed application with a permanent magnet alternator (PMA). The fail safe furling approach for shutdown has not been used to our knowledge.

Robert W. Preus; DOE Project Officer - Keith Bennett

2008-04-23T23:59:59.000Z

499

Coal-fueled high-speed diesel engine development. Annual technical progress report, October 1990--September 1991  

SciTech Connect (OSTI)

The objectives of this program are to study combustion feasibility by running Series 149 engine tests at high speeds with a fuel injection and combustion system designed for coal-water-slurry (CWS). The following criteria will be used to judge feasibility: (1) engine operation for sustained periods over the load range at speeds from 600 to 1900 rpm. The 149 engine for mine-haul trucks has a rated speed of 1900 rpm; (2) reasonable fuel economy and coal burnout rate; (3) reasonable cost of the engine design concept and CWS fuel compared to future oil prices.

Not Available

1991-11-01T23:59:59.000Z

500

Acoustic grating fringe projector for high-speed and high-precision three-dimensional shape measurements  

SciTech Connect (OSTI)

A new acoustic grating fringe projector (AGFP) was developed for high-speed and high-precision 3D measurement. A new acoustic grating fringe projection theory is also proposed to describe the optical system. The AGFP instrument can adjust the spatial phase and period of fringes with unprecedented speed and accuracy. Using rf power proportional-integral-derivative (PID) control and CCD synchronous control, we obtain fringes with fine sinusoidal characteristics and realize high-speed acquisition of image data. Using the device, we obtained a precise phase map for a 3D profile. In addition, the AGFP can work in running fringe mode, which could be applied in other measurement fields.

Yin Xuebing; Zhao Huijie; Zeng Junyu; Qu Yufu

2007-05-20T23:59:59.000Z